Chapter 11 讨论 Discussion 11.1内容 讨论的主要作用是回容引言中是出的门思：用箔果论证答案以及该答案与己有知识的一致性。讨论的 内容包括：①对引言中所提问愿的解答，以及对该答案的论证、解释及辩护：②解释与答案不符的结果： ①指出创新点及与他人结果的不同之处：④解释意外的发现：⑤解释方法的局限性、实验设计上的到点及 假设的有效性：®说明酥究重要性。 1111回答间题 针对州言中所提的问腿作出回答。注意在问题与容案中尽可能采用同样的关键词、动词和视角，动词 应采用现在时。例知，问思是：“Does sympathetic stimultion increase norepinephrine symthesis in rat superior cervical ganglia in vivo?”,答案可以是“This study shows th sympathetic stimula城ion increases norepinephrine synthesis in rat superior cervicall ganglia in vivo.""This study shows that sympathetic stimulation deeso increase norepinephrine s到ynthes8 n rat superior cervical gangli结in vivo.。如果改变美健词、动同和视角会使 答案难以理解。 A.指明答案适用的群体答案适用范围具限于相应的群体。当答案是有关人的研究时，贝适用于 样本所属的群体。例知，研究早产儿呼吸窘追综合任，答案将适用于所有悲该综合征的早产儿。然面，可 能井不适用于步手吸膏迫锦合征的足月儿和步其熊疾病的早产儿，所以答案中必须指出“in preterm infants who have respiratory distress syndrome”。对于动物实教，根据所提出的间思，答案可能仅限于动物，也可能 适用于部分或所有的人群.创如，上述间题·Does分mpathetic stimultion increase norepinephrine synthe丞in ms划perior cervieal ganglia in vivo?”是关于大佩的，所以答案适用于大鼠。如果将动物作为某一人类疾病 的限型来研究，则答案就可能适用于唐该转的人韩。 B月题和答案的对应时论中的答案应当与引言中的问题相对应。讨论中不要解答引言中未提到 的问题。例如，篇论著引言中仅月及第六个月胎儿伟中的特异性的激素调节蛋白是什么，讨论中却给了 2个答案，【个答案是查明有3种类甲微素调节蛋自，另1答案是式中2种类型激素调节蛋白来源于Ⅱ型 细胞和成纤维细胞：但引言中并没有提出蛋白的细电米源问题。针对第二个答案，须在引言中增加1个问 恶“hat are the cellular sources of the hormorally regulated proteins?",，使前后对应。如果作者认为第二个 问思和容案无足轻重，可以在摘要和题目中不提：但是，如果讨论中有这个容案，则在引言中必须有针对 它的提月： 1112答案的论正 119
129 Chapter 11 讨 论 Discussion 11.1 内容 讨论的主要作用是回答引言中提出的问题；用结果论证答案以及该答案与已有知识的一致性。讨论的 内容包括：①对引言中所提问题的解答，以及对该答案的论证、解释及辩护；②解释与答案不符的结果； ③指出创新点及与他人结果的不同之处；④解释意外的发现；⑤解释方法的局限性、实验设计上的弱点及 假设的有效性；⑥说明研究重要性。 11.1.1 回答问题 针对引言中所提的问题作出回答，注意在问题与答案中尽可能采用同样的关键词、动词和视角，动词 应采用现在时。例如，问题是：“Does sympathetic stimulation increase norepinephrine synthesis in rat superior cervical ganglia in vivo?”，答案可以是“This study shows that sympathetic stimulation increases norepinephrine synthesis in rat superior cervical ganglia in vivo.”或“This study shows that sympathetic stimulation does not increase norepinephrine synthesis in rat superior cervical ganglia in vivo.”。如果改变关键词、动词和视角会使 答案难以理解。 A. 指明答案适用的群体 答案适用范围只限于相应的群体。当答案是有关人的研究时，只适用于 样本所属的群体。例如，研究早产儿呼吸窘迫综合征，答案将适用于所有患该综合征的早产儿。然而，可 能并不适用于患呼吸窘迫综合征的足月儿和患其他疾病的早产儿，所以答案中必须指出“in preterm infants who have respiratory distress syndrome”。对于动物实验，根据所提出的问题，答案可能仅限于动物，也可能 适用于部分或所有的人群。例如，上述问题“Does sympathetic stimulation increase norepinephrine synthesis in rat superior cervical ganglia in vivo?”是关于大鼠的，所以答案适用于大鼠。如果将动物作为某一人类疾病 的模型来研究，则答案就可能适用于患该病的人群。 B. 问题和答案的对应 讨论中的答案应当与引言中的问题相对应。讨论中不要解答引言中未提到 的问题。例如，1 篇论著引言中仅问及第六个月胎儿肺中的特异性的激素调节蛋白是什么，讨论中却给了 2 个答案，1 个答案是查明有 3 种类型激素调节蛋白，另 1 答案是其中 2 种类型激素调节蛋白来源于 II 型 细胞和成纤维细胞；但引言中并没有提出蛋白的细胞来源问题。针对第二个答案，须在引言中增加 1 个问 题“What are the cellular sources of the hormonally regulated proteins?”，使前后对应。如果作者认为第二个 问题和答案无足轻重，可以在摘要和题目中不提；但是，如果讨论中有这个答案，则在引言中必须有针对 它的提问。 11.1.2 答案的论证
有时答案根简短，仅仅是对主要结果的一种陈述。例如，针对问题“o determine surface tension within al小veoli at total lung capcit的y,答案为“In this study we fourd that,at37C,lveolar surface tension at total lung ©apacity is297±56(SD)mNm”。在这种情况下，戴无需提侠论据，作者只若用别人己发表的数值为自 己的答案作辩护气Example11.5). A.陈述结果为答案提供迁据 答案可以是结果的直接总结，也可以是间接的。因面常与结果不等 同。为了使读者确偏答案的有效性，目答句题后要陈述一下相关的结果。如果看到一定的数据有助干读者 理解，也可以引用图和表。不要假定读者已经记住了结果或会通过查阅结果正文、图和表找出有关答案的 证据，讨论的日的正是要通过素材偏排让读者读到【个故事。 从Example11.I和11.2可看到2种把结果与其所论证的答案联系起米的方法。Example1L.1深用了连 接短语，面Examp收112则采用了主题句和连接问， Example11,1用连接短语联系结果和容案 The experiments presented here show that cloned human tumor necrosis factor a inhibits the expression of MYC in the human promyelocytie leukemie cell line HL-60 sekctively and that it does so by decreasing the rae or synthesis of MYC mRNA Evidence that the inhihition of MYC gere expression is selective is that expression of'mMRNA for reference proteins HLA-A.-B and-C was not inhibited.In fact,transcription of HLAA.-B.and .C mRNA was slightly increased (Fig.5).Evidence that the rate of synthesis of MYC mRNA decreases is that the half-life of degradation of MYC mRNA remained unchuarged in cells treated with cloned human tumor necrosis factor a (Fig 4)and that in nuclear 'run on"assarys,cloned human tumor necrosis factor a decreased the rae of MYC gene expression. 该例文的丰题句中陈递了2个答案，而作为证据的箔果则由1个重复了主愿句关键词的连接短语明入。 同样的手法也可见于Exmple114, Example 11.2用主思句联系结果和答案 The hemodynamic data obeained in this stuty indicate that in the open-chest living dog a waterfall effect occurs in the large pulmonary veins where they exit from the surfhce of the lumngs.Its presence has heen demonstrated in two wavs.First,the finding that upstream intrapulmonary venous pressures were influenced by changes in downstream extrapulmonary venous pressure at high but rot at low downstream pressures is consistent with the coneept of a pulmonary venous waterfall effect between the two measuring sites.Second,we found that under conditions of physiological flow when the downstream pressure of the pulmooary veins was zero,there was a short segmers where the vein was leaving the lung in which intravascular pressure changed sharply from a positive upstream to zero downstream pressure. 该例文用主题句和连接词把结果与答案联系了品米。 且作为答案证据的结果与结果小结提债合适的结果作为答案的证据（如Example11.1和112》不 同于以结果小结作为讨论的开始。这种不问在于结具小结巴一块块的拼图小块料成排：而用用应结果为答 案提供证据，是将一块块的拼图小块拼成一幅图面。讨论的目的是展示图画，让我们能看到作为答室证据 的结果，进而，相信答案是正确的。面绘制一幅图函的写作技巧就是采用主题句、连接短语和违接词 C.白我支持和支持别人如果别人的结果有助于论证保的答案，要提到这些结果，并引用参考文 献。不要夸大或贬低自己的责就。对别人的也应如此。如果别人的结果正好证实了你的观点，或你的工 找到了连接许多零散事实的缺环。可直说不妨。不要太逐虚也不能太自夸。从Example113中可见自我支 转和支持别人的写法 上me113自我支持和支持别人 By using whole mounts stained hisochemically for acetylcholinesterase.we have reconstructed an overall picture of the architccture of the nerves and ganglia of the ferret trachea.This reconstruction.whoch incorporates and confirms the separate observatiors of previous investigators (6,9,11,14,24)includes several new observations that prowide a more complete understanding of the trachesl innervation. 该例文讨论中的第一句是答案，第二句支持了别人，同时也点明作者本人的贡献是什么。 130
130 有时答案很简短，仅仅是对主要结果的一种陈述。例如，针对问题“to determine surface tension within alveoli at total lung capacity”，答案为“In this study we found that, at 37°C, alveolar surface tension at total lung capacity is 29.7 ± 5.6 (SD) mN/m”。在这种情况下，就无需提供论据，作者只需用别人已发表的数值为自 己的答案作辩护(Example 11.5)。 A. 陈述结果为答案提供证据 答案可以是结果的直接总结，也可以是间接的，因而常与结果不等 同。为了使读者确信答案的有效性，回答问题后要陈述一下相关的结果。如果看到一定的数据有助于读者 理解，也可以引用图和表。不要假定读者已经记住了结果或会通过查阅结果正文、图和表找出有关答案的 证据。讨论的目的正是要通过素材编排让读者读到 1 个故事。 从 Example 11.1 和 11.2 可看到 2 种把结果与其所论证的答案联系起来的方法。Example 11.1 采用了连 接短语，而 Example 11.2 则采用了主题句和连接词。 Example 11.1 用连接短语联系结果和答案 The experiments presented here show that cloned human tumor necrosis factor a inhibits the expression of MYC in the human promyelocytic leukemic cell line HL-60 selectively and that it does so by dec reasing the rate or synthesis of MYC mRNA. Evidence that the inhibition of MYC gene expression is selective is that expression of mMRNA for reference proteins HLA-A, -B and –C was not inhibited. In fact, transcription of HLA-A, -B, and -C mRNA was slightly increased (Fig. 5). Evidence that the rate of synthesis of MYC mRNA decreases is that the half-life of degradation of MYC mRNA remained unchanged in cells treated with cloned human tumor necrosis factor a (Fig. 4) and that in nuclear "run on" assays, cloned human tumor necrosis factor a decreased the rate of MYC gene expression. 该例文的主题句中陈述了 2 个答案，而作为证据的结果则由 1 个重复了主题句关键词的连接短语引入。 同样的手法也可见于 Example 11.14。 Example 11.2 用主题句联系结果和答案 The hemodynamic data obtained in this study indicate that in the open-chest living dog a waterfall effect occurs in the large pulmonary veins where they exit from the surface of the lungs. Its presence has been demonstrated in two ways. First, the finding that upstream intrapulmonary venous pressures were influenced by changes in downstream extrapulmonary venous pressure at high but not at low downstream pressures is consistent with the concept of a pulmonary venous waterfall effect between the two measuring sites. Second, we found that under conditions of physiological flow when the downstream pressure of the pulmonary veins was zero, there was a short segment where the vein was leaving the lung in which intravascular pressure changed sharply from a positive upstream to zero downstream pressure. 该例文用主题句和连接词把结果与答案联系了起来。 B. 作为答案证据的结果与结果小结 提供合适的结果作为答案的证据（如 Example 11.1 和 11.2）不 同于以结果小结作为讨论的开始。这种不同在于结果小结把一块块的拼图小块排成排；而用相应结果为答 案提供证据，是将一块块的拼图小块拼成一幅图画。讨论的目的是展示图画，让我们能看到作为答案证据 的结果，进而，相信答案是正确的。而绘制一幅图画的写作技巧就是采用主题句、连接短语和连接词。 C. 自我支持和支持别人 如果别人的结果有助于论证你的答案，要提到这些结果，并引用参考文 献。不要夸大或贬低自己的贡献，对别人的也应如此。如果别人的结果正好证实了你的观点，或你的工作 找到了连接许多零散事实的缺环，可直说不妨。不要太谦虚也不能太自夸。从 Example 11.3 中可见自我支 持和支持别人的写法 Example 11.3 自我支持和支持别人 By using whole mounts stained histochemically for acetylcholinesterase, we have reconstructed an overall picture of the architecture of the nerves and ganglia of the ferret trachea. This reconstruction, which incorporates and confirms the separate observations of previous investigators (6, 9, 11, 14, 24), includes several new observations that provide a more complete understanding of the tracheal innervation. 该例文讨论中的第一句是答案，第二句支持了别人，同时也点明作者本人的贡献是什么
11.13解释容案 讨论中除了提供答案并用结果如以论正外，可能还需要对答案进行解释。例如，为什么该答案是合理 的？它与以往的观点一致性知何？后一何思的例子见apk114的第二、三段。 Example11.4答案的解释 1 In this study.we have found a second example of'clustering for two members of the large collagen gene family and have demonstrated physical linkage between genes that have the same function-incoding both chains of a single collagen type.Specifically.we have conclusively localized the human a2 type IV collagen gene to the distal long amm of chromosome 13 by two independent methods.Hybridization o DNA from rodent-human hybrids with different deletions of chromosome 13 assigned the a2 (IV)locus to the segment 13q22-terminus. Mapping by the chromosomal in situ technique allowed more refined sublocaliztion to the distal q33-q34 region This region also contairs the al (IV)locus(30),as shown diagrammatically in Fig 5. 2 These results thus lend further credence to our earlier suggestion that one might expect to find clustering of several oollagen members and dispersion of others in a fashion anlogous to the globin pattern (36).In that pattern, two separate multigene clusters containing the c and B glohin geres are present on chromosomes 16 and 11. respectively (43-45).At both loci.the genes are tightly linked and contiguous. 3 The arrangement of the collagen genes that we report here is also reminiscent of the histones,since clusters of different histone genes map to at least three human chromosomes (46).For the histone gene family.we previously hypothesized that an ancestral site existed that gave rise to the present clusters distributed among multiple chromosomes by means of mechanisms involving recombinatian (36).A similar situation now emerges for the collagen gene family. 这个例子中的第一段陈述了针对间通的答案，并月结果作为正据对答案进行了论证。后两段解释了该 答案（胶无帮因簇）与以往观点的一改性（球蛋白和组蛋白基因横》。 111.4为答案辩护 如果针对你所提出的目圈，可能已经有人提出的答案，或看容易塑到黑的答案，那末，你就应当解 释为什么你的答案更好，辩护时，既要说明自己的答案为什么更令人满意，也要解释别的答案为什么不是。 也就是说。你月时必须论证自己的答案和取斥别人的答案。只有正反两方论证才能使你的答案令人信服。 Example11.5是1个正反两方论证的例子. Example115为答案料护 In this study,we found that,at 37C,alveolar surface tension at total lung capacity is 29.7+56(SD)mN/m. We believe that this value,which we determined by a direet technique,is accurate because it is close to the known equilibrium surface tension of about 25 mNim for extracts comtaining pulmonary surfactant (10,11)However, higher surface tensions have been suggested by other investigators,who did surface balance studies of lung extracts.Their values range from 31 to 50 mNim (7.8.12).But deducing values for alveolar surface tension from lung extracts in surface balances is uncertain.because the actual concentration of surface-active agents at the alveolar surfhoe is not known (5,13).We suspeet that the concentration ofsurface-active agents in lung extracts as usually asesed in surface balances might be lower than thoe in alveoli at total lung capacity and that if higher concentrations were used,surface tension values deduced from surface balance studies might be closer to equlibrium values. 该例中，第一句表述了作者的答案《用直接方法获得的表而张力值)：第二句通过与已知的平衡态下 的表面张力值进行比较，对答案作了斜护，这是正反两方论证的正方论证。该段的其他都分是反方论证， 指出因为所用的方法不能测量相同的量，所以其他不同的容案不可能是对的。如果我们能接受正反两方面 的论证，那么我们就会认可作者的答案。 13
131 11.1.3 解释答案 讨论中除了提供答案并用结果加以论证外，可能还需要对答案进行解释。例如，为什么该答案是合理 的？它与以往的观点一致性如何？后一问题的例子见 Example 11.4 的第二、三段。 Example 11.4 答案的解释 1 In this study, we have found a second example of clustering for two members of the large collagen gene family and have demonstrated physical linkage between genes that have the same function - incoding both chains of a single collagen type. Specifically, we have conclusively localized the human a2 type IV collagen gene to the distal long arm of chromosome 13 by two independent methods. Hybridization to DNA from rodent-human hybrids with different deletions of chromosome 13 assigned the a2 (IV) locus to the segment 13q22®terminus. Mapping by the chromosomal in situ technique allowed more refined sublocalization to the distal q33®q34 region. This region also contains the a1 (IV) locus (30), as shown diagrammatically in Fig. 5. 2 These results thus lend further credence to our earlier suggestion that one might expect to find clustering of several collagen members and dispersion of others in a fashion analogous to the globin pattern (36). In that pattern, two separate multigene clusters containing the a and b globin genes are present on chromosomes 16 and 11, respectively (43-45). At both loci, the genes are tightly linked and contiguous. 3 The arrangement of the collagen genes that we report here is also reminiscent of the histones, since clusters of different histone genes map to at least three human chromosomes (46). For the histone gene family, we previously hypothesized that an ancestral site existed that gave rise to the present clusters distributed among multiple chromosomes by means of mechanisms involving recombination (36). A similar situation now emerges for the collagen gene family. 这个例子中的第一段陈述了针对问题的答案，并用结果作为证据对答案进行了论证。后两段解释了该 答案（胶元基因簇）与以往观点的一致性（球蛋白和组蛋白基因簇）。 11.1.4 为答案辩护 如果针对你所提出的问题，可能已经有人提出别的答案，或者容易想到别的答案，那末，你就应当解 释为什么你的答案更好。辩护时，既要说明自己的答案为什么更令人满意，也要解释别的答案为什么不是。 也就是说，你同时必须论证自己的答案和驳斥别人的答案。只有正反两方论证才能使你的答案令人信服。 Example 11.5 是 1 个正反两方论证的例子。 Example 11.5 为答案辩护 In this study, we found that, at 37°C, alveolar surface tension at total lung capacity is 29.7 ± 5.6 (SD) mN/m. We believe that this value, which we determined by a direct technique, is accurate because it is close to the known equilibrium surface tension of about 25 mN/m for extracts containing pulmonary surfactant (10,11). However, higher surface tensions have been suggested by other investigators, who did surface balance studies of lung extracts. Their values range from 31 to 50 mN/m (7, 8, 12). But deducing values for alveolar surface tension from lung extracts in surface balances is uncertain, because the actual concentration of surface-active agents at the alveolar surface is not known (5, 13). We suspect that the concentration of surface-active agents in lung extracts as usually assessed in surface balances might be lower than those in alveoli at total lung capacity and that if higher concentrations were used, surface tension values deduced from surface balance studies might be closer to equilibrium values. 该例中，第一句表述了作者的答案（用直接方法获得的表面张力值）；第二句通过与已知的平衡态下 的表面张力值进行比较，对答案作了辩护，这是正反两方论证的正方论证。该段的其他部分是反方论证， 指出因为所用的方法不能测量相同的量，所以其他不同的答案不可能是对的。如果我们能接受正反两方面 的论证，那么我们就会认可作者的答案
11.1.5自相子清结果的解释 陈述答案、提供结果迁据、解释和料护是必要的。此外，也必须提到保实验中得到的不能作为答案证 据的结果，并尽可能地做出解释，对自相矛盾结果的解释可参考xm耶e16的最后3句话， (Hlowever..=》a Example11.6自相子盾结果的解释 The main finding of the present study is that B-adrenergic blockade does not impuir performance of maximal or submaximal exercise at high altitude As expected,treatment with the B-blocker propranokl substantially decreased heart rate at high altitude.However.contrary to our hypothesis.propranolotreaed subjects were able to maintain levels of oygen upeake during maximal and submaximal exercise as great as thooe in placebo-treated subjects This finding cannot be attributed to increased arterial oxygen saturation or hemoglobin concentration, since values for propranolol-treated subieets were no ditlerent from those for placebo-treated subpects Rather,it appears that oxygen uptake was maintained hy increasing stroke volume. 该例文的第三句指出了】个与答案相矛盾的结果：第四句作了】个可能的解释：第五句提出了另】个 可能的解释。 11.1.6指出创新处 引言中陈述了都些是未知的，也就指出了保工作的新意所在。如果想让读者记住你的创新处，可以把 你的工作要点与己知的进行对比，见Example17付论的前2句， Example11.7指出创牙处 Partial cDNA clooes have been reported for mouse (38-40),rat (41,42),and human (24)B-glucuronidase.In this study.we report the complete sequence of the full-lergth cDNA for human B-glucuronidase 木例通过第一句的“artial'”与第二句的“full-lerg功”对比，指出了创新处。 要避免声称优先权(This is the first代ort of…),因为相同的成非常相似的工作，可能己经在其它 国家用英语成其它语言发表了，如果你很强烈陆希望表达这种优先权，那么用问语气应当谨镇。如“T00 knowledge.this is the first report of..". 1117解释与别人的结果不一致 固然，别人结果与保的一致并成了答案迁据，这很好，但是，有时情况相反，别人的所究结果似乎应 该与你的一致，而实际上却不一致。这种差异看很好地如以解释（见Example1l.8). Epe118解释与别人的结果不一致 Apparent discrepencies between our human growth hormone values and those of earlier studies may be due to differences in study design.In our study,all subjects worked at the same relative intensity (60%Voax)which meant different absolute work loads because of the subjects'different levels of cardiorespirmory endurance and body fatness Moreover,the imensity wus constant for 60 min Farlier studies that reported lower training responses differed from this stuy design in one of three ways:controls and trained subjects were working at the same absolue work loads or relative imensity was not detined (12.22.271:the protocol was continaous and had progressive increases in work load,so intensity and duration were not separated (1,12,29).or resting human growth hormone values were higher in the pretraining than in the post-training protocol(12). 11,18意外发现的解释 有的意外发无微不足道：有的令人据奋：有的甚至比原先的问题更令人兴奋，面成了论著的主角（见 ECse11.1)。受落一开始就应描述出人意外的发现.面后尽可雀地予以解释，见Example11.9。 112
132 11.1.5 自相矛盾结果的解释 陈述答案、提供结果证据、解释和辩护是必要的。此外，也必须提到你实验中得到的不能作为答案证 据的结果 ，并尽可能地做出解释。对自相矛盾结果的解释可参考 Example 11.6 的最后 3 句话。 （However, ……）。 Example 11.6 自相矛盾结果的解释 The main finding of the present study is that b-adrenergic blockade does not impair performance of maximal or submaximal exercise at high altitude. As expected, treatment with the b-blocker propranolol substantially decreased heart rate at high altitude. However, contrary to our hypothesis, propranolol-treated subjects were able to maintain levels of oxygen uptake during maximal and submaximal exercise as great as those in placebo-treated subjects. This finding cannot be attributed to increased arterial oxygen saturation or hemoglobin concentration, since values for propranolol-treated subjects were no different from those for placebo-treated subjects. Rather, it appears that oxygen uptake was maintained by increasing stroke volume. 该例文的第三句指出了 1 个与答案相矛盾的结果；第四句作了 1 个可能的解释；第五句提出了另 1 个 可能的解释。 11.1.6 指出创新处 引言中陈述了那些是未知的，也就指出了你工作的新意所在。如果想让读者记住你的创新处，可以把 你的工作要点与已知的进行对比，见 Example 11.7 讨论的前 2 句。 Example 11.7 指出创新处 Partial cDNA clones have been reported for mouse (38-40), rat (41, 42), and human (24) b-glucuronidase. In this study, we report the complete sequence of the full-length cDNA for human b-glucuronidase. 本例通过第一句的“partial”与第二句的“full-length”对比，指出了创新处。 要避免声称优先权（This is the first report of ……），因为相同的或非常相似的工作，可能已经在其它 国家用英语或其它语言发表了。如果你很强烈地希望表达这种优先权，那么用词语气应当谨慎，如“To our knowledge, this is the first report of ……”。 11.1.7 解释与别人的结果不一致 固然，别人结果与你的一致并成了答案证据，这很好，但是，有时情况相反，别人的研究结果似乎应 该与你的一致，而实际上却不一致。这种差异需很好地加以解释（见 Example 11.8）。 Example 11.8 解释与别人的结果不一致 Apparent discrepancies between our human growth hormone values and those of earlier studies may be due to differences in study design. In our study, all subjects worked at the same relative intensity (60% Vo 2max), which meant different absolute work loads because of the subjects' different levels of cardiorespiratory endurance and body fatness. Moreover, the intensity was constant for 60 min. Earlier studies that reported lower training responses differed from this study design in one of three ways: controls and trained subjects were working at the same absolute work loads or relative intensity was not defined (12, 22, 27); the protocol was continuous and had progressive increases in work load, so intensity and duration were not separated (1, 12, 29); or resting human growth hormone values were higher in the pretraining than in the post-training protocol (12). 11.1.8 意外发现的解释 有的意外发现微不足道；有的令人振奋；有的甚至比原先的问题更令人兴奋，而成了论著的主角（见 Exercise 11.1）。段落一开始就应描述出人意外的发现，随后尽可能地予以解释，见 Example 11.9
Example119意外发见的解释 A surprising finding was that in dogs trealed with tsoproterenol.ooygen extraction ratios dunng severe hypoxia were low.The ratios we found were less than 50%,whereas ratios in untreated dogs range from 80 to %(4)We suggest two possible explanations of why extraction of oxygen from skeletal muscle was not further increased to minimize the oxygen deficit in the isoproterenol-treated dogs.First,blood flow may have been directed through thoroughfare.nonnutrntive channels during B-adrenerg stimulation rather than through nutritive channels.thereby decreasing the abillity of the tissue to take up oxygen Second,some metabolic autoregularory stimulus may have dictated the amount of oxygen extraction was decreased in proportion to decreased metabolic needs If these explanations are correct,they imply that the oxygen deficit is linked not only to oxygen delivery but also to some tissue sigral onginating at the cellular level 1119方法的局限性、实脸设计的寄点及假设合理性 如果方法上存在局限性，实验设计上有写点，或设计的基础是某种假设，然应陈运这种局限性，弱点 和假设是什么，并解释为什么可以接受它门。如果解释贝是简加的1一2句话，战在方法中卿可。如果长 达1一2段，或者有关同限性、离点和假设可使严重影利结果，则解释可以收在时论部分。如果可能，应 该把这些相关的解释组织成1个故事〔见Eapk11,19)。Exmple11,10对假设的合理性作了解释： Epe1L,10对服设合理性的解释 One assumption we made for the measuremert of the pulmonary cipillary filtration coefficient (K was that isolating the lungs did not injure pulmorary vessels.This is a reasonable assumption.because we minimized lung ischemia by remowing the lungs rapidly (within 5 min).In addition,the baseline K valuesn our study are low and agree with other repored K values (33).Finally,we have found that lungs isolated and perfused in a similar manner are stable for 3 h(unpublished observution). 在这个例子中，作者先告诉读者实的设计有怎样1个假设，然后讲了3个理由说明该假设的合理性。 11.1.10i说切重要性 有时从创新可以明显地看出工作的重要性。例知，若某一东病的病因尚不清楚，而你正对此做出报道。 在基础研究里，创新也同样是重要性的指标。在引言或讨论中均可指明工作的重要性。时论中。可以通过 网述答案的应用价植、理论意文及其引出的思考来指明工作的重要性。应用价值、理论意义及其相关思考 常当作讨论的结尾。 11.2组织结构 为确保讨论的写作有章法、不散乱，就好象是在诗1个故事，该故事的重点是回容引言中提到的问题， 应有开头、中间和结尾3个部分。讨论的开头邻分（黄一，二段）戴必领给出问题的答案，并用结果米论 证之。以问题的答案作为开头，是强调司愿本身的最好方法。讨论的中同部分用来讨论与答案相关的论题。 按重要性大小排列假述序。讨论的结尾部分《是后一段)应再次降述答案，也可以做出特定的立论。 写作时论的精要是：①讨论一开始便给出H圈的答案：②按超重要性的主次组织其他论点：①段落开 头用主题句来闲明论点：①每一段的论点要紧扣前一段的论点。 112.1讨论怎样开头 时论的开头处在】个很显限的位置，理应把最重要的观点成在此处。也即针对刊器的答案。你在引言 中提出了问题，并在方法和结果中介绍了针对该问题你做了什么和发现了什么，这就使读者产生了想如道 133
133 Example 11.9 意外发现的解释 A surprising finding was that in dogs treated with isoproterenol, oxygen extraction ratios during severe hypoxia were low. The ratios we found were less than 50%, whereas ratios in untreated dogs range from 80 to 90% (4). We suggest two possible explanations of why extraction of oxygen from skeletal muscle was not further increased to minimize the oxygen deficit in the isoproterenol-treated dogs. First, blood flow may have been directed through thoroughfare, nonnutritive channels during b-adrenergic stimulation rather than through nutritive channels, thereby decreasing the ability of the tissue to take up oxygen. Second, some metabolic autoregulatory stimulus may have dictated the amount of oxygen extraction was decreased in proportion to decreased metabolic needs. If these explanations are correct, they imply that the oxygen deficit is linked not only to oxygen delivery but also to some tissue signal originating at the cellular level. 11.1.9 方法的局限性、实验设计的弱点及假设合理性 如果方法上存在局限性，实验设计上有弱点，或设计的基础是某种假设，就应陈述这种局限性、弱点 和假设是什么，并解释为什么可以接受它们。如果解释只是简短的 1～2 句话，放在方法中即可。如果长 达 1～2 段，或者有关局限性、弱点和假设可能严重影响结果，则解释可以放在讨论部分。如果可能，应 该把这些相关的解释组织成 1 个故事（见 Example 11.19）。Example 11.10 对假设的合理性作了解释。 Example 11.10 对假设合理性的解释 One assumption we made for the measurement of the pulmonary capillary filtration coefficient (Kf) was that isolating the lungs did not injure pulmonary vessels. This is a reasonable assumption, because we minimized lung ischemia by removing the lungs rapidly (within 5 min). In addition, the baseline Kf values in our study are low and agree with other reported Kf values (33). Finally, we have found that lungs isolated and perfused in a similar manner are stable for 3 h (unpublished observation). 在这个例子中，作者先告诉读者实验设计有怎样 1 个假设，然后讲了 3 个理由说明该假设的合理性。 11.1.10 说明重要性 有时从创新可以明显地看出工作的重要性。例如，若某一疾病的病因尚不清楚，而你正对此做出报道。 在基础研究里，创新也同样是重要性的指标。在引言或讨论中均可指明工作的重要性。讨论中，可以通过 阐述答案的应用价值、理论意义及其引出的思考来指明工作的重要性。应用价值、理论意义及其相关思考 常当作讨论的结尾。 11.2 组织结构 为确保讨论的写作有章法、不散乱，就好象是在讲 1 个故事，该故事的重点是回答引言中提到的问题， 应有开头、中间和结尾 3 个部分。讨论的开头部分（第一、二段）就必须给出问题的答案，并用结果来论 证之。以问题的答案作为开头，是强调问题本身的最好方法。讨论的中间部分用来讨论与答案相关的论题， 按重要性大小排列叙述顺序。讨论的结尾部分（最后一段）应再次陈述答案，也可以做出特定的立论。 写作讨论的精要是：①讨论一开始便给出问题的答案；②按照重要性的主次组织其他论点；③段落开 头用主题句来阐明论点；④每一段的论点要紧扣前一段的论点。 11.2.1 讨论怎样开头 讨论的开头处在 1 个很显眼的位置，理应把最重要的观点放在此处，也即针对问题的答案。你在引言 中提出了问题，并在方法和结果中介绍了针对该问题你做了什么和发现了什么，这就使读者产生了想知道
答案的期望。因此，答案是论著的高满，在讨论中型应放在最重要的开头位置。 A给答案作标记在答案句的开头用提示语指标记。如“This stuc心h0msh一”，“O9s indicate that.…”,“n this study we found that…”等。给答案作标记根重要，因为没有提示用语，容案 会技错认为是已知的素西，例年。“Polymorphonuckar leukocytes can now be induced to release a number of varieties of granule-poor anucleate fragments (cytoplasts),each with its own uses for the study of leukocyte ft0n”,这一句虽放在付论的开始处，自很难知道是答案还是在讲已知的东西。为了使该问题的答案显 而易见，应当作标记，例如，可以写成“Imh店，efae cremted polymorphonuclear leukocyies that can be induced to release a number of vaneties of granule-poor anucleate fragments (cytoplasts)each with its own uses for the study of leukoevle function.". 且指明所研究的动物和属成人群知引言中的间塑句一样。讨论中的答案句也必须指明所研究的 动物种属或人群，答案中流及所研究的动物种属或人种应与问腿中的一数(Exmk11.15),若问题是概 性的，可在答案的提示短语中指明动物种属〔Example 11.1I):研究对象若是人，可以不提(Example 111211.14). C,有关讨论开头方法的例文 先给出答案。村论最直接了当的开头方法是给出国的蓉案，要确保答案是针对你所提的思。国 果你的研究仅镂及【个句愿。可以直接习容该句题及开始你的讨论，并用提示语给答案句作标记。在标记 用语或在答案中，还应指明动物种属或人群· Exampl11,11仅有1个答案的写法 This study n newborw gows demonstraes that comtirus positive airway pressure (7.5 cm Ho)can impair renal function in newborns 该答案句先是提示短语〔未划线部分)，后为答案本身（划线留分）.实的所用动物种属（斜体字）在 提示复语中指明，这是因为答案的意义不仅限于这种动物.答案与引言中的闩圈：“The purpose of this study was to further define the effects of continuous positive airwny pressure on renal function in newboms.”一政。果 用了相同的关健可(contimnuous positive airw0 pressure,renal function,newborns)以及相同的程角（即从原 因看结果). 如果研究是针对2个间恩，可以月2个问愿的回答作为时论的开始，如Ex即k1112的写法。也可 以在第一段的开头仪回答1个间愿，以后（多在第二及的开头）再国答另1个何圆。在2个付思的答案之 间。仅插入论证第一个答案的结果。每一个答案都要有提示短语。答案的顺序与引言中问题的顺序相应， Example11.12有2个答案的写法 Ou experimests show thar cigarette-smoke-induced bronchoconstriction is much more severe than previously reported and that this beonchoconstriciton is mediated principally by extravaeal mechanisms 这个句子回答了引言中提出的2个问题。用1个提示短语(Our experiments show that)标记2个答案， 第二个答案前重复了“h”,以标示这也是】个答案。因为研究对象是人，所以未提及动椅种属。引言中 "We reassessed the sverir ofcigarette-smoke-induced bronchoconstriction...We also determined the mechanism of cigarette-smoke-induced broechocorstriction.”,答案句使用了相同的关健间（划线都分），所以 很清楚是2个答案日答了2个问题。 如果问愿有3个或3个以上，讨论的开头给出所有的答案，这样看起来某象是个总结。因此，讨论的 第一段最好只目答第一个问思成最重要的问题，其他间题的答案欧在随后段落的开始处。最后一段可以重 复所有的答案，这也是小结的最好位置。 )先重复间题再给出答案。在讨论开始，可以先用1句话重复间愿，然后再讲答案。因为有时直接给 出答案会显得突然。讨论中重复问塑时，除了保迁与引言中所提问题的意义一致外，同样也应与答案采用 同样的关键词、动词和祝角。 Example1L.13问圈和答案 The question addressed by the present study was whether the chemical stimuli hypersapn and hpoia affect the magnitude of the abdominal expiratocy neural activity in the absence of amy changes in proprioceptive afferent activity from the lungs and chest and abdominal walls.The main finding of the study is that progressive 13
134 答案的期望。因此，答案是论著的高潮，在讨论中理应放在最重要的开头位置。 A. 给答案作标记 在答案句的开头用提示语作标记，如“This study shows that… …”，“Our results indicate that… …”，“In this study we found that … …”等。给答案作标记很重要，因为没有提示用语，答案 会被错认为是已知的东西，例如，“Polymorphonuclear leukocytes can now be induced to release a number of varieties of granule-poor anucleate fragments (cytoplasts), each with its own uses for the study of leukocyte function.”，这一句虽放在讨论的开始处，但很难知道是答案还是在讲已知的东西。为了使该问题的答案显 而易见，应当作标记，例如，可以写成“In this study, we have created polymorphonuclear leukocytes that can be induced to release a number of varieties of granule-poor anucleate fragments (cytoplasts), each with its own uses for the study of leukocyte function.”。 B. 指明所研究的动物种属或人群 如引言中的问题句一样，讨论中的答案句也必须指明所研究的 动物种属或人群。答案中谈及所研究的动物种属或人群应与问题中的一致（Example 11.15）。若问题是概 括性的，可在答案的提示短语中指明动物种属（Example 11.11）；研究对象若是人，可以不提（Example 11.12～11.14）。 C. 有关讨论开头方法的例文 a) 先给出答案。讨论最直接了当的开头方法是给出问题的答案，要确保答案是针对你所提的问题。如 果你的研究仅涉及 1 个问题，可以直接回答该问题及开始你的讨论，并用提示语给答案句作标记。在标记 用语或在答案中，还应指明动物种属或人群。 Example 11.11 仅有 1 个答案的写法 This study in newborn goats demonstrates that continuous positive airway pressure (7.5 cm H2O) can impair renal function in newborns. 该答案句先是提示短语（未划线部分），后为答案本身（划线部分）。实验所用动物种属（斜体字）在 提示短语中指明，这是因为答案的意义不仅限于这种动物。答案与引言中的问题：“The purpose of this study was to further define the effects of continuous positive airway pressure on renal function in newborns.”一致。采 用了相同的关键词（continuous positive airway pressure, renal function, newborns）以及相同的视角（即从原 因看结果）。 如果研究是针对 2 个问题，可以用 2 个问题的回答作为讨论的开始，如 Example 11.12 的写法。也可 以在第一段的开头仅回答 1 个问题，以后（多在第二段的开头）再回答另 1 个问题。在 2 个问题的答案之 间，仅插入论证第一个答案的结果。每一个答案都要有提示短语，答案的顺序与引言中问题的顺序相应。 Example 11.12 有 2 个答案的写法 Our experiments show that cigarette-smoke-induced bronchoconstriction is much more severe than previously reported and that this bronchoconstriciton is mediated principally by extravagal mechanisms. 这个句子回答了引言中提出的 2 个问题。用 1 个提示短语（Our experiments show that）标记 2 个答案， 第二个答案前重复了“that”，以标示这也是 1 个答案。因为研究对象是人，所以未提及动物种属。引言中 问题是“We reassessed the severity of cigarette-smoke-induced bronchoconstriction…. We also determined the mechanism of cigarette-smoke-induced bronchoconstriction.”，答案句使用了相同的关键词（划线部分），所以 很清楚是 2 个答案回答了 2 个问题。 如果问题有 3 个或 3 个以上，讨论的开头给出所有的答案，这样看起来就象是个总结。因此，讨论的 第一段最好只回答第一个问题或最重要的问题，其他问题的答案放在随后段落的开始处。最后一段可以重 复所有的答案，这也是小结的最好位置。 b) 先重复问题再给出答案。在讨论开始，可以先用 1 句话重复问题，然后再讲答案。因为有时直接给 出答案会显得突然。讨论中重复问题时，除了保证与引言中所提问题的意义一致外，同样也应与答案采用 同样的关键词、动词和视角。 Example 11.13 问题和答案 The question addressed by the present study was whether the chemical stimuli hypercapnia and hypoxia affect the magnitude of the abdominal expiratory neural activity in the absence of any changes in proprioceptive afferent activity from the lungs and chest and abdominal walls. The main finding of the study is that progressive
hyperoxic hypercapnia and isocapnic hypaxia both increase abdominal expiratory neural activity while concurrently decreasing expiratory duration.For hypercapnia,the increases in the varables related to the magnitude of the abdominal neurogram and arterial Peo.were linear,whereas for hypoxia the increases were hy perbolic. 这个例文的问题和答案使用了相月的关键词和视角（从原因看结果）。且讨论中重复的问题与引言中 所提问题一我，"The aim of the present study wis to determine whether hper边nd mr affect the magnitude of the abdominal expiratory neural ativity in the abserxe of amy changes in peoprioceptive afferent activity from the lung些and chest and abdominal walls”。给出答案后便用结果论i证之，还用了连接短语标记答 案，复语中重复了关键词：“For hypercapnia,…far hypaxis:”. 如果讨论一开始就重述问思，票末必须立即给出答案。不要一开始就长篇回顾实验方法。如果要说明 实验方法，也应简短些。答案句出现的感退，读者找到它的困避就越大。Example11.14的答案延迟到第三、 第四句才出现。 Example1L.14衡圈米迟的答案 What makes an intiator tRNA an inirimor and not an elongator?In an amempt to answer this question.we removed from Ecoli tRNA two of the features common to all prokcaryotic initiator tRNAs isolated and characterized the mutant tRNAs,and studied their function in prolein synthesis in vitro.We found that what makes an initimor tRNA an initiator is not the Fl mutation,becase this mutation had no effect on protein synthesis (Fig.1).Rather the CoC sequence comserved in the anticodon stem of both prokaryotic and cukaryotic initiator tRNAs is importart for initiation.In our experiments.as one.two.and dl three of the GC base pairs were alsered to those found in E.col elorgatoe methionine tRNA,the activity of the mutant tRNAs in probein synthesis initintion decreased progressively.a mutant with all three GC base pairs altered being the least active (Fig 3).The etfect of the mutation was at the step of inititor tRNA binding to the ribosomal P site (Table 2). 在这个例子中，第一句重述了问恩，第二句陈述了相关的实验方法。第三，第四句才是容案。薄三句 用答案句提示语开头，然后用与题一样的关键司、动问和视角价了【个棱否定了的答案，结尾是否定的 单因。第四句才是拔接受的答案，因为在月题和答案之间插进了实验方法，所以第三句果用答案句提示语， 重复关健词和动司，保持同样的视角，就显得特别重要，第四句虽然改变了视角和动问，但因为用“h” 与技否定的第三句答案进行了对比，因而清楚地标记旧这是【个答案句。该段的最后2句，用结果证据 论证了容案，并用“In0 ar experiment'”标示是作者的结果。 ©)简要背景和答案。为了避免时论开头的康突，也可以先简要地介绍背景，再写答案。介绍背最必须 简短（最好一句话），且与引言中的观点一政。如果写了3句或更多，这便是第二个引言了，2个引言完全 没有必要。甚至是有害的。读者会感到选多：作者到联想让我们看厚个引言？因为科研论著中引言和时论 是1个整体的2个部分，要塑使讨论正好开始于引言的结束，最好的办法就是使讨论中的背景介绍尽可能 的简洁。 Example11.15背景和答案 Previous investigalors sugested that drainage of liquid from the lungs of fetal rabbits begins at birth (1.2) and is inhibited by cesarean section(2).Our results show that drairage of fetal lung liquid in rahhits before birth depends on the experience of labor,not on the mode of delivery. 本例第一句为膏景，第二句为回答了2个列恶的答案句。第一个容案与背景的前部分紧密对应，这使 原来的月题与该研究的结论之阿的差别一目了然。尽管讨论的开头先重复月题和简述背景再给出月题的答 案，的确较圆滑流畅，但是最好方法恰是最简单的方法：直接给出答案。这样，读者最容易找到它，面且 印象也最深。 几.开始时论的不可取的到子不要以结夏的小结作为可论的开头。型将它收在结限中。结果部分 其实瓷应该是结果的小结。知果你觉得结果部分己经写得过长，想把结果的小结故在讨论的开头时，你应 考虑酬除过长的结果都分，仅下简复的小结。不要以次要的信思作为时论的开头，次要信息应放在间通 的答案之后。 Empe1L.16讨论的开头是次要信息（不可取） The small but significart loss of plasma volume during the last 10 min of the normoxie rest period is difficult to explain 115
135 hyperoxic hypercapnia and isocapnic hypoxia both increase abdominal expiratory neural activity while concurrently decreasing expiratory duration. For hypercapnia, the increases in the variables related to the magnitude of the abdominal neurogram and arterial Pco2 were linear, whereas for hypoxia the increases were hyperbolic. 这个例文的问题和答案使用了相同的关键词和视角（从原因看结果），且讨论中重复的问题与引言中 所提问题一致：“The aim of the present study was to determine whether hypercapnia and hypoxia affect the magnitude of the abdominal expiratory neural activity in the absence of any changes in proprioceptive afferent activity from the lungs and chest and abdominal walls”。给出答案后便用结果论证之，还用了连接短语标记答 案，短语中重复了关键词：“For hypercapnia, …… for hypoxia ……”。 如果讨论一开始就重述问题，那末必须立即给出答案。不要一开始就长篇回顾实验方法。如果要说明 实验方法，也应简短些。答案句出现的越迟，读者找到它的困难就越大。Example 11.14 的答案延迟到第三、 第四句才出现。 Example 11.14 跚跚来迟的答案 What makes an initiator tRNA an initiator and not an elongator? In an attempt to answer this question, we removed from E.coli tRNAfMet 2 two of the features common to all prokaryotic initiator tRNAs, isolated and characterized the mutant tRNAs, and studied their function in protein synthesis in vitro. We found that what makes an initiator tRNA an initiator is not the T-1 mutation, because this mutation had no effect on protein synthesis (Fig. 1). Rather the G C G C G C sequence conserved in the anticodon stem of both prokaryotic and eukaryotic initiator tRNAs is important for initiation. In our experiments, as one, two, and all three of the G·C base pairs were altered to those found in E.coli elongator methionine tRNA, the activity of the mutant tRNAs in protein synthesis initiation decreased progressively, a mutant with all three G·C base pairs altered being the least active (Fig. 3). The effect of the mutation was at the step of initiator tRNA binding to the ribosomal P site (Table 2). 在这个例子中，第一句重述了问题，第二句陈述了相关的实验方法。第三、第四句才是答案。第三句 用答案句提示语开头，然后用与问题一样的关键词、动词和视角给了 1 个被否定了的答案，结尾是否定的 原因。第四句才是被接受的答案。因为在问题和答案之间插进了实验方法，所以第三句采用答案句提示语、 重复关键词和动词、保持同样的视角，就显得特别重要。第四句虽然改变了视角和动词，但因为用“rather” 与被否定的第三句答案进行了对比，因而清楚地标记出这是 1 个答案句。 该段的最后 2 句，用结果证据 论证了答案，并用“In our experiment”标示是作者的结果。 c) 简要背景和答案。为了避免讨论开头的唐突，也可以先简要地介绍背景，再写答案。介绍背景必须 简短（最好一句话），且与引言中的观点一致。如果写了 3 句或更多，这便是第二个引言了。2 个引言完全 没有必要，甚至是有害的。读者会感到迷惑：作者到底想让我们看哪个引言？因为科研论著中引言和讨论 是 1 个整体的 2 个部分，要想使讨论正好开始于引言的结束，最好的办法就是使讨论中的背景介绍尽可能 的简洁。 Example 11.15 背景和答案 Previous investigators suggested that drainage of liquid from the lungs of fetal rabbits begins at birth (1, 2) and is inhibited by cesarean section (2). Our results show that drainage of fetal lung liquid in rabbits before birth depends on the experience of labor, not on the mode of delivery. 本例第一句为背景，第二句为回答了 2 个问题的答案句。第一个答案与背景的前部分紧密对应，这使 原来的问题与该研究的结论之间的差别一目了然。尽管讨论的开头先重复问题和简述背景再给出问题的答 案，的确较圆滑流畅，但是最好方法恰是最简单的方法：直接给出答案，这样，读者最容易找到它，而且 印象也最深。 D. 开始讨论的不可取的例子 不要以结果的小结作为讨论的开头，应将它放在结果中。结果部分 其实就应该是结果的小结。如果你觉得结果部分已经写得过长，想把结果的小结放在讨论的开头时，你应 考虑删除过长的结果部分，仅留下简短的小结。不要以次要的信息作为讨论的开头，次要信息应放在问题 的答案之后。 Example 11.16 讨论的开头是次要信息（不可取) The small but significant loss of plasma volume during the last 10 min of the normoxic rest period is difficult to explain
引言中的问是“to determine if the efflux in plasma volume diring hypoxic submaximal and maximal exercise in the supine posture can exceed the maximum I5-22%reported for normoxic conditions".该月题使我 们期望，讨论的开头将告知运动时缺氧个体的血浆花出量是否超过22%，但我们看到的。却是1个次要的 意外发现（休息状态下个体的血聚容量减少），这是1个误导的开头。 Epe1117讨论的开头为次要信息（不可取） The results of the endurance time for the sustained isometne exereise at different contraction levels were consistent with previous reports (4.25). 这个讨论的开头没有直接回答间题（问题是确定he endurance time during exercise consisting of sustained isometric contractions,mermittent isometric6 ontractice色，and dynamic contractioe.),而是与原有的 发残作比较，后者贝是一个次要信息。恶讨论的开头让给次要信息实在很可情，次要信息应放在问题回答 之后。 1122封论的继续与性式主盟句 A.主题的组织回答问题后该怎样潍续时论？量常用的方法是按重要性的主次写。重要性则取决 于与答案主题的关系。应把论证容案的结果，解释和料护放在其也主题前。 有时可能不止！段与答案有相同的关系（例如杯是论证答案的结果），应把它们集中放在同一个小节 中。这样，讨论就包括一系列小节，每个小节包括1个或数个段落。小节应按重要性主次持列。同理。每 个小节中的段落也要按重要性主次排列，Example11.31的讨论就是这样组织的。 重要性的判断颜为主观和相对，因北，可一算论署的不月作者对相同主愿的组织。可能并不不具：甚 至同一作者也可能会根据以后新发表的论著，以不同的方式来组织主题， B讲述故事全望除了按重要性主次来组织主盟和段落外。还必须告诉读者：组织的逻辑性是什 么，即主题的挂序理由。段落的主思句不仅要说明该段落的主恩。也要说明与前一授的关系。换言之，除 了在每一段里详运故事外，还要在整个时论里用主马句构建1个完幕的故事。 用段落主题句构建完整故事的方式有2种。一种是一开头就给出1个全婉（全蚊方法）：另一种是一 步步展开（逐步展开法），所谓全貌方法，即在每一小节的开始用1个主题句指出该小节的主题，其中的 每一段又采用1个违接句和主题句开头，一个个段落依次下去。这样，读者微可以预先知道在随后的2段 甚至更多段中，会有什么内容。逐步展开法与此不同，作者区在每一段的开头用1个主题句讲述故事的这 一步，下一段的开始用另1个主题句讲述下一步，一受一段依次展开。段落间通过重复关园同加以暖系。 这样，读者不俺顶先如道下一步的内容，而是随着作者进行思考，一次一步地走。 全舰方法的促点是容易读懂所讨论的故事，逐步展开法的促点是有匙味性，感觉差不多了，但放事又 没完。然而，逐步展开法要成功。需要处理得当。特划是关键词的重复必须明确，使读者不至于失去故事 的线索。 C采用主题句讲述故事全貌 )用主通句总览的方法。该法可在2个层次上使用主题句：即小节和段落。小节主题句凝括了时论中 该小节的主思和总体安排。为了联系小节所述故事的每一步，每一夜的开始需使用连接性主题句，即含有 连接词、连接复语、连接从句的主题句（见Pmpe1118), Emp11.18小节主题句和连接问主题句 Aseveral hemotnamic effeets of shromonar sould shift the diastolic pressurssimension surve acutely. one is an increase in heart rate,which could shift the diastolic pressure-dimension curve to the left by cither of two mechanisms (etc. 2 CAsecod hemodynamic effect,afterload,can also shift the diastolic pressure-dimension curve.(e) 3 DAud effect that can cuely shift the pressuredimension cunve to the left is ischemia.(etc.) 4 Ehe fal hemodyramie effect that can shift the pressure-dimersion curve acutely is change in temperature. (ete.) 本例中，小节主题句〔A句)相出了其后4仪的主.其后4个段落主句《B一E句)那分别以1 136
136 引言中的问题是“to determine if the efflux in plasma volume during hypoxic submaximal and maximal exercise in the supine posture can exceed the maximum 15-22% reported for normoxic conditions.”。该问题使我 们期望，讨论的开头将告知运动时缺氧个体的血浆流出量是否超过 22%；但我们看到的，却是 1 个次要的 意外发现（休息状态下个体的血浆容量减少），这是 1 个误导的开头。 Example 11.17 讨论的开头为次要信息（不可取） The results of the endurance time for the sustained isometric exercise at different contraction levels were consistent with previous reports (4.25). 这个讨论的开头没有直接回答问题（问题是确定 the endurance time during exercise consisting of sustained isometric contractions, intermittent isometric contractions, and dynamic contractions.），而是与原有的 发现作比较，后者只是一个次要信息。把讨论的开头让给次要信息实在很可惜，次要信息应放在问题回答 之后。 11.2.2 讨论的继续与链式主题句 A. 主题的组织 回答问题后该怎样继续讨论？最常用的方法是按重要性的主次写。重要性则取决 于与答案主题的关系。应把论证答案的结果、解释和辩护放在其他主题前。 有时可能不止 1 段与答案有相同的关系（例如都是论证答案的结果），应把它们集中放在同一个小节 中。这样，讨论就包括一系列小节，每个小节包括 1 个或数个段落。小节应按重要性主次排列，同理，每 个小节中的段落也要按重要性主次排列，Example 11.31 的讨论就是这样组织的。 重要性的判断颇为主观和相对，因此，同一篇论著的不同作者对相同主题的组织，可能并不不同；甚 至同一作者也可能会根据以后新发表的论著，以不同的方式来组织主题， B. 讲述故事全貌 除了按重要性主次来组织主题和段落外，还必须告诉读者：组织的逻辑性是什 么，即主题的排序理由。段落的主题句不仅要说明该段落的主题，也要说明与前一段的关系。换言之，除 了在每一段里讲述故事外，还要在整个讨论里用主题句构建 1 个完整的故事。 用段落主题句构建完整故事的方式有 2 种。一种是一开头就给出 1 个全貌（全貌方法）；另一种是一 步步展开（逐步展开法）。所谓全貌方法，即在每一小节的开始用 1 个主题句指出该小节的主题，其中的 每一段又采用 1 个连接句和主题句开头，一个个段落依次下去。这样，读者就可以预先知道在随后的 2 段 甚至更多段中，会有什么内容。逐步展开法与此不同，作者应在每一段的开头用 1 个主题句讲述故事的这 一步，下一段的开始用另 1 个主题句讲述下一步，一段一段依次展开。段落间通过重复关键词加以联系。 这样，读者不能预先知道下一步的内容，而是随着作者进行思考，一次一步地走。 全貌方法的优点是容易读懂所讨论的故事；逐步展开法的优点是有趣味性，感觉差不多了，但故事又 没完。然而，逐步展开法要成功，需要处理得当，特别是关键词的重复必须明确，使读者不至于失去故事 的线索。 C. 采用主题句讲述故事全貌 a) 用主题句总览的方法。该法可在 2 个层次上使用主题句：即小节和段落。小节主题句概括了讨论中 该小节的主题和总体安排。为了联系小节所述故事的每一步，每一段的开始需使用连接性主题句，即含有 连接词、连接短语、连接从句的主题句（见 Example 11.18）。 Example 11.18 小节主题句和连接词主题句 1 ASeveral hemodynamic effects of chromonar could shift the diastolic pressure-dimension curve acutely. BOne is an increase in heart rate, which could shift the diastolic pressure-dimension curve to the left by either of two mechanisms. (etc.) 2 CA second hemodynamic effect, afterload, can also shift the diastolic pressure-dimension curve. (etc.) 3 DA third effect that can acutely shift the pressure-dimension curve to the left is ischemia. (etc.) 4 EThe final hemodynamic effect that can shift the pressure-dimension curve acutely is change in temperature. (etc.) 本例中，小节主题句（A 句）指出了其后 4 段的主题。其后 4 个段落主题句（B～E 句）都分别以 1
个连接词：“One、“Aond”、.“A亡”、“The final”开头，因此，也称为连接词主题句. b)保特小节内故事的连续。为了使小节内故事的潍续展开，第一段之后的各段落的主题句要使用语气 更强的连接方式。一种方法是段落主题句中，更多地重复小节主恩句中的关键词，如Example1l18。另一 种方法是用连接短语减连接性从句来替代连接讽，知a水1119。 Exam即eIl.I8中第一个段落主题句(B句)，仅仅使用了】个连接问(Oe》,因为该段落主题句紧接楼 着小节主圈句，1个筒单的连接问是以保证讨论的潍续。然而，简二段离小节主愿句较远，所以就需要较 强的连接方式，该段主置句(C句)除了采用连接闻“As处cand”外，还重复2个关键词“hemodynamic” 和“effect'”。第三、四段的主题句的连接方式更强，除了分别果用连接词“A”和“The final'”外，还 各自重复了6个关键词.即D句的effect..cutely,s小f,pressure-dimension,curve,let和E句的hemodynamic, effect、.hin、pressure-dimensico、curve,xue小y,通过重复更多的关键问，这些连接性主圈句可时时提醒 读署故事在讲什么，而连接词还提示读者读到故事的何处， ©)保特小节何故事的连续。时论时除了保持小节内故事的连续性外，还必须保持小节之间做事的连续 性。为此，在每个新小节主题句的开头，要使用！个连接短语或连接从句。由于违接短语或连接从句在指 出下一个小指的主题前，先总结了前一小节的主题，所以比连接词更强题，王ampl119第5段开始的连 接短语肥有关方法局限性的小节（第【一4段）和有关方法优越性的小节（第5段）暖系起来。连接短语 总结了前一小节的主题（即局限性），句子的其他舒分指明了下一个小节的主题（即优越性》： sample11,19小节主题句和连接复语主思句 AThe imprecision we detected in the precursoprodt relationship could haveisn from limitations of the method BOne limittion is experimental varability.( Cmethod is contamination of materials.(ete.) 3 DAud limitation ofo method is that recovery of materials is incomplese.(etc.) 4 EAlimitation of our method is that the assumpetions used for defining compartments may not be justificd.(elc.) 5 FDesite mhese lmitnos our method of data ansis has advantages onver those previously used to salculate surfactant turnower times GUnlike the method of Zilversmit et al.(8).it uses the specific activity-time data and readily reveals departures from ideal precurscoproduct relationships HUnlike curve-peeling methods, it accounts for continued input of tracer and avoids the up to 200-fold overestimation of tumover time caused by neglecting continued traoer input 在这个例子中，第1段首句《A句)是第1一4爱的小节主恩句。第1一4段的受落主思句各使用1个 连接问，即Ome.Another、Ahid和A fourth来提程读者阅读到故事何处。另外，由于第2一4段的主题 句离小节主题句较运，为了提示故事在讲什么，因而重复了更多的关键词，即mitation of our m©hcd,而 第一段的主超句仅重复limitation. 第5段又开始了1个新的小节，其主圈句的连接方式更强，以一个连接复语开头总结了第1一4段的 主盟，Despite thes×limitations,然后周述第5段的主遇，0 ur meth0 d of data aralys6 has advanages over those previously used to calculale surfactant turnover times,这个连接短语主哥句通过指明I个重要的连接点，保i证 了故事的完整和顺畅。如果不用或贝用I个连接词〔如nevertheless),读者就难以理解所讲的故事。 还有，小节主句《A句)违月第5段开头的连接粗语主题句概括了故事的全貌。通过阅读这2个主 题句，可知该故事分两部分，一是A句The imprecisi0 we detected in the precursor-product relationship cod have arisen from limitations of the method".F"Despite these limitations,our method of data analysis has ad小antage over those previously used to calcula能surfactant tumover times"。前者是由4个段落组成的I个小 节，含5个主题句，其中第1段包括小节主题句和1个段落主题句，第2~4段各有1个段落主题句：后 者是由！个段落组成的1个小节。最后要指出的是，该例也写了方法的局限性，认为这种局限性是前体 产物关系不精确的可能单因。 更有力的连接主思句是连接从句主置句，它起作用的方式与连接短语主恩句相同，但它还包含了1个 动司，所以比连接短语更有力，Empl110第2段开头句(L句)线是1个连接从句。 Example 11.20 层次主题句和连接从句主思句 137
137 个连接词：“One”、“A second”、“A third”、“The final”开头，因此，也称为连接词主题句。 b) 保持小节内故事的连续。为了使小节内故事的继续展开，第一段之后的各段落的主题句要使用语气 更强的连接方式。一种方法是段落主题句中，更多地重复小节主题句中的关键词，如 Example 11.18。另一 种方法是用连接短语或连接性从句来替代连接词，如 Example 11.19。 Example 11.18 中第一个段落主题句（B 句），仅仅使用了 1 个连接词（One），因为该段落主题句紧接 着小节主题句，1 个简单的连接词足以保证讨论的继续。然而，第二段离小节主题句较远，所以就需要较 强的连接方式，该段主题句（C 句）除了采用连接词“A second”外，还重复 2 个关键词“hemodynamic” 和“effect”。第三、四段的主题句的连接方式更强，除了分别采用连接词“A third”和“The final”外，还 各自重复了6个关键词，即D句的effect、acutely、shift、pressure-dimension、curve、left和 E句的hemodynamic、 effect、shift、pressure-dimension、curve、acutely，通过重复更多的关键词，这些连接性主题句可时时提醒 读者故事在讲什么，而连接词还提示读者读到故事的何处。 c) 保持小节间故事的连续。讨论时除了保持小节内故事的连续性外，还必须保持小节之间故事的连续 性。为此，在每个新小节主题句的开头，要使用 1 个连接短语或连接从句。由于连接短语或连接从句在指 出下一个小节的主题前，先总结了前一小节的主题，所以比连接词更强烈。Example 11.19 第 5 段开始的连 接短语把有关方法局限性的小节（第 1～4 段）和有关方法优越性的小节（第 5 段）联系起来。连接短语 总结了前一小节的主题（即局限性），句子的其他部分指明了下一个小节的主题（即优越性）。 Example 11.19 小节主题句和连接短语主题句 1 AThe imprecision we detected in the precursor-product relationship could have arisen from limitations of the method. BOne limitation is experimental variability. (etc.) 2 CAnother limitation of our method is contamination of materials. (etc.) 3 DA third limitation of our method is that recovery of materials is incomplete. (etc.) 4 EA fourth limitation of our method is that the assumptions used for defining compartments may not be justified. (etc.) 5 FDespite these limitations, our method of data analysis has advantages over those previously used to calculate surfactant turnover times. GUnlike the method of Zilversmit et al. (8), it uses the specific activity-time data and readily reveals departures from ideal precursor-product relationships. HUnlike curve-peeling methods, it accounts for continued input of tracer and avoids the up to 200-fold overestimation of turnover time caused by neglecting continued tracer input. 在这个例子中，第 1 段首句（A 句）是第 1～4 段的小节主题句。第 1～4 段的段落主题句各使用 1 个 连接词，即 One、Another、A third 和 A fourth 来提醒读者阅读到故事何处。另外，由于第 2～4 段的主题 句离小节主题句较远，为了提示故事在讲什么，因而重复了更多的关键词，即 limitation of our method，而 第一段的主题句仅重复 limitation。 第 5 段又开始了 1 个新的小节，其主题句的连接方式更强，以一个连接短语开头总结了第 1～4 段的 主题：Despite these limitations，然后阐述第 5 段的主题：our method of data analysis has advantages over those previously used to calculate surfactant turnover times。这个连接短语主题句通过指明 1 个重要的连接点，保证 了故事的完整和顺畅。如果不用或只用 1 个连接词（如 nevertheless），读者就难以理解所讲的故事。 还有，小节主题句（A 句）连同第 5 段开头的连接短语主题句概括了故事的全貌。通过阅读这 2 个主 题句，可知该故事分两部分：一是 A 句“The imprecision we detected in the precursor-product relationship could have arisen from limitations of the method”，二是 F 句“Despite these limitations, our method of data analysis has advantage over those previously used to calculate surfactant turnover times”。前者是由 4 个段落组成的 1 个小 节，含 5 个主题句，其中第 1 段包括小节主题句和 1 个段落主题句，第 2～4 段各有 1 个段落主题句；后 者是由 1 个段落组成的 1 个小节。最后要指出的是，该例也写了方法的局限性，认为这种局限性是前体- 产物关系不精确的可能原因。 更有力的连接主题句是连接从句主题句，它起作用的方式与连接短语主题句相同，但它还包含了 1 个 动词，所以比连接短语更有力。Example 11.20 第 2 段开头句（L 句）就是 1 个连接从句。 Example 11.20 层次主题句和连接从句主题句
1 4This study in tars shows that perfusion and ventilaticn of transplanted bngs desreased inkrendenth b the reimplantarion responss BPerfusion is decreased by stenosis of the pulmonary artery anastomoses and by hilar stripping of the lung CStenosis of the pulmonary artery appears to be more important DThe evidence is that stcnosis of the arstomosis of the pulmonary artery resuled in very low perfision of the lung immedialely after it was transplanted(Fig 2).This finding is in acodance with results of studies in dog lung trarsplants which showed that stenosis of vascular arastomoses increases vascular resistance of the transplanted lung (23,24). which would decrese perfusion.FHilar stripping of the lung also decreased perfusion,but this effect was only mild and transient(Fig.2).Gin the literature some authors concluded from reimplantation studies in dogs that hilar stripping of the lung causes pemmanendly abnormal values of pulmonary vascular resistance and perfusion (25)HHowever,our results clearly support the coeclussian of other arhars that it is no hilar stripping (26,27) but rather imperfect vascular anastomoses (23,24.28)that permanertly decrease perfusion in the transplamed lung.Iit is wor clear how Julor动npping induces the ent deerease可fusion,、Blood vessels might be compressed by perivascular edema.which was present for some das after hilar stripping However.this does not appear to be a satisfactory explaration of the perfusion decrease because the edema resolved rapidly.but the perfusion ramained decreasod for two woeks. ventilation of the transplarted left lung is decreased for some dys after transplantation because of interstitial and alveolar seta resulting trom traersplantation tschemia ard from hilar strippine M车dkaw图observed in the bronchus during transplantation (Table IV)in histologic sections (Fig.6A).and on chest radiograms (Fig 4A) NThe increased density of transplanted lungs on chest radiograms is the most common phenomenon of the reimplantation resporse described in primates (9,29)and dogs (8.20.301 OOur conclusion that edema results from transplantation ischemia is clear frum our finding that edema formation increased proportionally to the duration of transplantation ischemia (Fig 3.Table IV).confirming previous findings in dogs (30).PHowever. pulmonary edema also developed in the absence of ischemia of the lung after hilar stripping (Figs.3 and 5). CAlthough the extent of the edema was mosty less than that caused hy transplantation ischemia,its histological patem was the same.RSo it sems likely that pulmonary edema is caused by hilar stripping injury of the lung and is aggravated by ischemia.SThis interpretation isn accordance with previous findings from our laboratory which showed that bilateral hilar stripping.when combined with ischemia of the lungs for at least one hour. deereased arterial oxygen lension (27). 该例中，莲接从句主盟句处于第2段的开头，其中莲接从句（斜体字部分）总结了第1段的主题，主 句（非斜体字部分）阐述了第二段的主置。这个连接从句主题句可提解我们读到了故事的处。如知果只用 1个基本的主置句(L句非？体字雷分)，读者可能会失去对整体的把所，因为就儿段讲了太多的细节。 所以，位于放事全貌主要连接点的连接复语或连接从句转别有用。司读中断成读了含有许多细节的长 段落后，读者可能会丢失故事的战索，这时，连接复进或连接从句也有助于读者国到故事的全貌中。见 Example 11.20及Exercise11.1。 )墨岁展开法中的主感句。莲步展开法的刊论只有受落主遇句。没有小指主墨句和段落连接主句， 即其段落主思句不含有连接问。此时段与及之间的连续性依靠关健词主题句。即每个段落主题句重复上 段主题句中的某个关键问，并用该术语闸述一个新观点.Exam即e112】中的第二一五段的开头都使用了这 样的关键词主愿句： Empk1小2I关健问主题句 1 AThe present picture of the thick filamen assembly in catch muscles of molluses derives from the noton of a common plan for all myosin filaments (20).BSquire (21)proposed the first detailed packing models for such struetures using a scheme of overlapping myosin molecules CIn his models the overlapping myosin molecules make up plarar ribbons (about 35A thick)that wrap into eylinders.DThe filament diameters would be directly related to the number of molecules around the circumference.The core could he hollow or could contain paramyoosin. The hasic assumption in this model is that identical myosin molecules ae oquivalently related 113
138 1 AThis study in rats shows that perfusion and ventilation of transplanted lungs are decreased independently by the reimplantation response. BPerfusion is decreased by stenosis of the pulmonary artery anastomoses and by hilar stripping of the lung. CStenosis of the pulmonary artery appears to be more important. DThe evidence is that stenosis of the anastomosis of the pulmonary artery resulted in very low perfusion of the lung immediately after it was transplanted (Fig. 2). EThis finding is in accordance with results of studies in dog lung transplants which showed that stenosis of vascular anastomoses increases vascular resistance of the transplanted lung (23, 24), which would decrease perfusion. FHilar stripping of the lung also decreased perfusion, but this effect was only mild and transient (Fig. 2). GIn the literature some authors concluded from reimplantation studies in dogs that hilar stripping of the lung causes permanently abnormal values of pulmonary vascular resistance and perfusion (25). HHowever, our results clearly support the conclusion of other authors that it is not hilar stripping (26, 27) but rather imperfect vascular anastomoses (23, 24, 28) that permanently decrease perfusion in the transplanted lung. IIt is not clear how hilar stripping induces the transient decrease in perfusion. JBlood vessels might be compressed by perivascular edema, which was present for some days after hilar stripping. KHowever, this does not appear to be a satisfactory explanation of the perfusion decrease because the edema resolved rapidly, but the perfusion ramained decreased for two weeks. 2 LWhereas perfusion is decreased by stenosis of the pulmonary artery anastomoses and by hilar stripping, ventilation of the transplanted left lung is decreased for some days after transplantation because of interstitial and alveolar edema resulting from transplantation ischemia and from hilar stripping. MEdema was observed in the bronchus during transplantation (Table IV), in histologic sections (Fig. 6A), and on chest radiograms (Fig. 4A). NThe increased density of transplanted lungs on chest radiograms is the most common phenomenon of the reimplantation response described in primates (9, 29) and dogs (8, 20, 30). OOur conclusion that edema results from transplantation ischemia is clear from our finding that edema formation increased proportionally to the duration of transplantation ischemia (Fig. 3, Table IV), confirming previous findings in dogs (30). PHowever, pulmonary edema also developed in the absence of ischemia of the lung after hilar stripping (Figs. 3 and 5). QAlthough the extent of the edema was mostly less than that caused by transplantation ischemia, its histological pattern was the same. RSo it seems likely that pulmonary edema is caused by hilar stripping injury of the lung and is aggravated by ischemia. SThis interpretation is in accordance with previous findings from our laboratory which showed that bilateral hilar stripping, when combined with ischemia of the lungs for at least one hour, decreased arterial oxygen tension (27). 该例中，连接从句主题句处于第 2 段的开头。其中连接从句（斜体字部分）总结了第 1 段的主题，主 句（非斜体字部分）阐述了第二段的主题。这个连接从句主题句可提醒我们读到了故事的何处。如果只用 1 个基本的主题句（L 句非斜体字部分），读者可能会失去对整体的把握，因为前几段讲了太多的细节。 所以，位于故事全貌主要连接点的连接短语或连接从句特别有用。阅读中断或读了含有许多细节的长 段落后，读者可能会丢失故事的线索，这时，连接短语或连接从句也有助于读者回到故事的全貌中。见 Example 11.20 及 Exercise11.1。 d) 逐步展开法中的主题句。逐步展开法的讨论只有段落主题句，没有小节主题句和段落连接主题句， 即其段落主题句不含有连接词。此时段与段之间的连续性依靠关键词主题句，即每个段落主题句重复上一 段主题句中的某个关键词，并用该术语阐述一个新观点。Example 11.21 中的第二～五段的开头都使用了这 样的关键词主题句。 Example 11.21 关键词主题句 1 AThe present picture of the thick filament assembly in catch muscles of molluscs derives from the notion of a common plan for all myosin filaments (20). BSquire (21) proposed the first detailed packing models for such structures using a scheme of overlapping myosin molecules. CIn his models the overlapping myosin molecules make up planar ribbons (about 35Å thick) that wrap into cylinders. DThe filament diameters would be directly related to the number of molecules around the circumference. EThe core could be hollow or could contain paramyosin. FThe basic assumption in this model is that identical myosin molecules are equivalently related