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C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Martin, J. H., Bruland, K. W. & Broenkow, W. W. in Marine Pollutant Transfer (eds Windom, H. & Duce, R.) 159-184 (Heath, Lexington, 1976).
Bruland, K. W., Franks, R. P., Knauer, G. A. & Martin, J. H. Analytica chim. Acta 105, 223-245 (1979).
Stumm, W. & Morgan, J. J. Aquatic Chemistry 2nd edn (Wiley, New York, 1981).
L... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 溶解铁主要以矿物粉尘的形式被吹入大海的。马丁得出结论,如果人为地将铁加入到这些缺铁的水中,就会有更多的浮游植物生长。这会把大气中的二氧化碳带入有机体组织中,于是就提供了一种去除温室气体从而“改变”气候的方法:“铁施肥”假说。在本文中,马丁和史蒂夫·菲茨沃特首次提出了加入铁能促进海水中浮游植物的生长的直接证据。这种方法是否能够(并且应该)大规模使用目前仍存在争议。 英文
南极近海表层水体[1-3]和亚北极区东北太平洋海域[4]出现了一种关于常量植物营养盐(PO4、NO3、SiO3)过剩的有趣海洋学问题。在之前的研究中[5],我们已给出了间接证据证明,Fe输入的不足是造成这种生长限制的原因;近期我们又有机会得以在亚北极区太平洋东北海域... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 英文
在“PAPA”海洋观测站(50.0° N;145.0° W)西北625 km处(55.5° N;147.5° W)和东南625 km处(45.0° N;142.89° W)的两个站位上也进行了相似的实验。得出的结果也基本相同,其中叶绿素的相关数据见图2。上述数据加上图1的数据均证明,在亚北极区东北太平洋海域,Fe限制着浮游植物的生长。通过适当的独立实验证实,该区可以作为李比希最小因子定律在海洋中的一个典型实例[9]。本研究还可以作为超净技术利用的实例,倘若不采用该技术,对照瓶中将会受到足量外来Fe的污染,从而刺激浮游植物的生长,导致对照结果与特意加入Fe的实验结果无法区分开来。 英文
图2.在45.0° N 142.89° ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 感谢俄勒冈州立大学的桑迪·穆尔和拉里·斯莫尔提供的VERTEX营养盐资料。本研究受到美国国家科学基金会海洋化学计划和美国海军研究办公室海洋化学计划的资金支持。 英文
(齐红艳 翻译;孙松 审稿)
Evidence for Global Warming in the Past Decade
P. D. Jones et al.
Editor’s Note
By the late 1980s, the possibility that rising concentrations of atmospheric carbon dioxide, caused by human activities, could alter climate ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | In 1986, some of us reported3 the first compilation of global mean temperature estimates, spanning the period 1861–1984. We have now extended this analysis to include 1985–87 and to improve the ocean and land coverage for the 1980s. The improved coverage for the 1980s slightly alters the original values for 1980–84. Ou... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | It is likely that the record warmth in 1987 partly resulted from the strong 1986–87 El Niño/Southern Oscillation (ENSO) event10,11, although this event was not as intense as the one in 1982–83. It is also possible that the stratospheric coldness in recent years is partly associated with the recent ozone depletion12,13.... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Heath. D. F. Nature 332, 219-227 (1988).
Kiehl, J. T., Boville, B. A. & Briegleb, B. P. Nature 332, 501-504 (1988).
过去十年中全球变暖的证据
琼斯等
编者按
自20世纪80年代末以来,由于人类活动造成大气中CO2浓度升高并可能通过增强温室效应改变全球气候的问题引起了人们的广泛关注。其潜在的科学道理是很清晰的,但自然过程也许有可能抵消这种人为变暖。我们首先要明确的是,自19世纪中期工业革命以来气候是否真的变暖了。1940~1980年间,全球温度变化很小,但是东安格利亚大学的菲利普·琼斯及其同事利用最新的资料研究发现,过... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | The GAL4-UAS system is used to study gene expression and function. It has two parts: the gal4 gene, which encodes the transcription-activating protein GAL4, and the upstream activation sequence (UAS), which binds GAL4 to activate transcription. Here molecular biologist Mark Ptashne and colleagues demonstrate that GAL4 ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | WE constructed an effector gene that expresses GAL4 in a tissue specific manner in Drosophila, and a reporter gene that allows the visualization of GAL4-activated transcription by a histochemical stain for β-galactosidase activity (Fig. 1). In the effector gene, expression of GAL4 is driven by a Drosophila Adh promoter... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | contains transcriptional termination sequences from hsp70. The effector and reporter genes were separately introduced into the D. melanogaster genome by P element transformation21,22.
Methods. The Adh promoter in the effector gene contains a BglII/BalI fragment from the 5′-flanking region of the D. mulleri Adh–1 gene w... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | XbaI linker into the SalI site of C70T (a gift of John Lis and colleagues), which is a derivative of Carnegie 20 (ref. 29) containing, in the SalI site, a 250 bp SalI/XhoI fragment of hsp70 gene terminator sequences. The P element plasmids were purified by banding in CsCl-EtBr gradients and coinjected at a concentratio... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | In each of the 27 crosses, we detected β-galactosidase activity in ~one quarter of the larval progeny. In all of these larvae, enzyme activity was observed at high levels in the fat body and anterior midgut (Fig. 2), two of the tissues in which we expect the Adh promoter of the effector gene to be active. Also as expec... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | are transformants (a gift of Dean Falb) carrying a gene like the reporter, except the enhancer of the D. melanogaster Adh gene’s distal promoter (–660 to –128 from the distal transcription start site; Dean Falb and T.M., unpublished data) was installed upstream of the truncated hsp70 promoter instead of the GAL4 17-mer... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | pSP73lac2 (see Fig. 1 legend) into pSP72 (ref. 28) digested with BglII and SmaI. Before transcription, SP6-hslac was digested with BglII, resulting in a ~450 nucleotide (nt) probe. The SP6-αtub probe25 protected a 90 nt fragment of the endogenous α1-tubulin gene transcripts. As shown, the SP6-hslac probe protected a 40... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Fig. 4. β-galactosidase activity in larval tissues of P element transformants. a, Diagram of the larval tissues in the photographs beneath: gastric caecae (gc), proventriculus (pro), anterior midgut (amg), middle midgut (mmg), posterior midgut (pmg), Malpighian tubules (mt), fat body (fb), and hindgut (hg) are indicate... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | We have shown that a single protein, GAL4, when expressed in a tissue specific manner, generates tissue specific gene expression in Drosophila. Typical tissue specific enhancers (the best characterized are those of mammalian genes) interact with several different proteins (ref. 23 and refs therein). Our results suggest... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Giniger, E., Varnum, S. M. & Ptashne, M. Cell 40, 767-774 (1985).
Brent, R. & Ptashne, M. Cell 43, 729-736 (1985).
Keegan, L., Gill, G. & Ptashne, M. Science 231, 699-704 (1986).
Ma, J. & Ptashne, M. Cell 48, 847-853 (1987).
Ma, J. & Ptashne, M. Cell 51, 113-119 (1987).
Gill, G. & Ptashne, M. Cell 51, 121-126 (1987).
H... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 在本文中,分子生物学家马克·普塔什尼和他的同事们证明了在果蝇中GAL4可激活转录。lazc报告基因的引入使得研究者可以通过组织特异性的方式观察到GAL4激活的转录,这项技术给他们提供了在特定组织类型中改变基因表达的方法。尽管GAL4是一种仅在酵母内发现的蛋白,但它能够在包括人类和模式生物如非洲爪蟾和斑马鱼在内的许多其他的物种中启动转录。 英文
GAL4是一种酵母调节蛋白,它可与UASG(半乳糖上游活化序列)上的特异性位点结合并激活连锁基因的转录[1-6]。激活需要这种蛋白的两个功能[7,8]:一个临近氨基末端的DNA结合域[8],以及一个或多个“激活域”[7-11]。激活域高度酸化 [9-11](也见参考文献12)并且可以被替换,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | pMH100[15]的29 bp KpnI/PstI片段的四个拷贝被克隆到pSP731ac2(迪安·法尔布惠赠)中hsp70/lacz基因上游的KpnI位点,上述片段包含高亲和性的(梅尔文·霍利斯和马克·普塔什尼,未发表数据;参考文献15)17-mer GAL4识别位点(ScaI 17-mer:5′-CGGAGTACTGTCCTCCG-3′),而pSP731ac2则是将hsp70/lacz基因作为一个SalI片段克隆到pSP73(参考文献28)的SalI位点。一个包含效应基因的4.8 kb的XbaI片段和一个包含报告基因的3.6 kb的XbaI片段分别以与红眼基因(rosy)相同的转录方向克隆到P因子转化载体C70TX(迪安·法尔布... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | )通过对泳道1~3中的hsp70/lacz和微管蛋白保护片段适当曝光的放射自显影照片的密度计量,显示GAL4增强子和ENH-hsp70/lacz中果蝇的Adh增强子的相对强度接近。hsp70/lacz与微管蛋白的信号比率通过基因拷贝数修正,并对泳道1的数据进行归一化,设定其值为1.0后:实验结果是0.3(泳道2)和1.2(泳道3)。因此,结合于17-mer序列的GAL4与Adh增强子在激活报告基因转录的能力上是相当的。
方法。RNA来自于活跃进食的三龄幼虫或ENH-hsp70/lacz成虫,制备方法按前人描述[24,25]。如前人描述[33],用SP6RNA聚合酶从质粒SP6-αtub[25](维基·科尔宾惠赠)和SP6-hslac... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 或许这种复杂性是通过一小部分的调节蛋白的调控来达到精细的基因控制模式。GAL4具有激活哺乳动物和果蝇启动子的能力,这提示我们,在酵母中一个与结合了DNA的GAL4相互作用的蛋白(或许是RNA聚合酶)可激活转录,它与高等真核生物中的RNA聚合酶高度同源。这表明至少有一类基因活化因子的作用机制很可能在酵母、哺乳动物细胞和果蝇之间是保守的。 英文
我们感谢迪安·法尔布慷慨地赠予未发表的质粒和转化体系,感谢杰拉尔德·鲁宾、梅尔文·霍利斯、利亚姆·基根和约翰·利斯赠予质粒。本研究受到美国癌症协会(由马克·普塔什尼承担)和美国国家卫生研究院(由汤姆·马尼阿蒂斯承担)的资助。 英文
(李梅 翻译;胡松年 审稿)
Mysteries of HIV... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | disease? 中文
What Governs Viral Tropism?
Recognition that the CD4 antigen on the surface of human helper T lymphocytes is a major cellular receptor for the HIV envelope protein gp1201 led to the inference that endocytosis of the virus by cells expressing the CD4 molecule is an initial step in infection. But although mou... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | The establishment of HIV infection requires several processes that are influenced by both viral and cellular factors. Strain variations in specific viral genes may, for example, account for the fact that, compared with blood isolates of HIV, isolates from the central nervous system replicate better in macrophages—the m... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | viral infection of all cell types. 中文
What Causes HIV Heterogeneity?
Biological heterogeneity of HIV is reflected by differences in host range, replicative properties and cytopathic effects in infected cells18. Restriction enzyme19 and sequence analyses20 of HIV isolates, as well as the patterns of neutralization of di... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Neuropathy. The disease in the central nervous system has been attributed by some investigators to the production by infected macrophages of cytokines that affect normal brain function5,26. HIV-infected brain capillary endothelial cells could compromise the maintenance of the blood–brain barrier, so permitting entry of... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Immunopathology. How HIV causes immune suppression presents the greatest enigma. The immune dysfunctions identified in HIV infection were first linked to the cytopathic effects of HIV on helper T lymphocytes that play a vital role in regulating immune function. These cells infected with HIV in vitro undergo syncytial f... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | These abnormalities appear to begin with acute depletion of T helper cells and proliferation of B cells; other defects, many revealed by in vitro studies, accumulate over time. Several of the immune abnormalities may result from the decrease in CD4+ lymphocytes and cytokine production32. 中文
What other mechanisms could ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | (b) virus mediated, enhanced immunogenicity of normal cellular proteins.
(5) Cytotoxic cell activity against viral or self proteins.
中文
In addition, HIV is associated, often early in the infection, with a polyclonal activation of B cells resulting in hypergammaglobulinaemia32. Some of these antibodies form immune co... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | phospholipid synthesis43. The accumulation of unintegrated proviral copies of HIV DNA is an attractive explanation for cytopathology since it is associated with cell death in other retrovirus systems44. Finally, whether the cytopathology of HIV in cell culture mirrors pathogenesis in the host awaits development of an a... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | clinical status. Peripheral blood mononuclear cells cultured from many patients with disease readily produce virus and their CD8+ cells show very little antiviral activity. 中文
This variation in HIV replication in cultured cells probably mirrors the increase of viral p25 antigen in the plasma of individuals as they adva... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | cells. 中文
Fig. 1. A model of possible stages in the course of HIV infection. (1) Acute infection is characterized by the presence of free-virus (or its antigen) in the blood in the absence of antibodies to HIV. (2) A CD8+ cells increase rapidly with a concomitant decrease in CD4+ cells; thus the helper/suppressor rati... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Latency. A long incubation period might also be explained by a latent infection. During the latent period of retrovirus infection very little viral protein or RNA is made and no infectious progeny are produced by the infected cell53. When cells that have been latently infected with HIV in culture are treated with activ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | an HIV strain evolves into a more cytopathic (and potentially pathogenic) agent18 would be valuable. We must find methods for inducing strong intracellular and cellular host responses against the virus: intracellular production of the orf-B protein or stimulation of the CD8+ cell population responsible for suppressing ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | (6) Portions of HIV proteins resemble normal cellular proteins. Immunization may induce autoantibodies.
(7) Vaccination may induce antibodies that enhance HIV infection.
中文
Studies conducted by the author were supported by the California State Universitywide Task Force on AIDS, the American Foundation for AIDS Resea... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Robert-Guroff, M. et al. J. Immun. 137, 3306-3309 (1986).
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Cohen, M. B. & Beckstead, J. in AIDS: Pathogenesis and Treatment (ed. Levy, J. A.) (Dekker, New York, in the pres... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Luciw, P. A. et al. Proc. Natl. Acad. Sci. U.S.A. 84, 1434-1438 (1987).
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神秘的HIV:它的治疗和预防面临的挑战
利维
编者按
五年前共同发现HIV的病毒学家杰伊·利维描述了HIV研究中未解决的问题。四个关键的领域值得给予特殊关注:病毒与细胞感染的决定因素,不同... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 显然,对于所有类型细胞抗病毒感染的治疗策略来说,HIV广泛的宿主范围和影响病毒复制的细胞因子都是需要定义的重要变量。 英文
是什么引起了HIV的异质性?
HIV的生物异质性反映在宿主范围、复制特性和感染细胞中的细胞病变作用的不同[18],HIV分离株的限制性内切酶[19]和序列分析[20],以及不同分离株中和抗体的模式[21],也证明遗传的多样性,尤其是包膜糖蛋白。(这是事实,不仅是HIV-1,还有最近发现的HIV-2亚型也是如此[22])。产生这些不同病毒株的机制令人费解。理论上的可能性是,未整合的HIV前病毒的拷贝在急性复制感染期过程中累积[23],能发生高效的基因重组,导致有感染性的变异体的演变。在持续感染的细胞中的整合病毒在... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 另外,HIV感染祖细胞能够减少外周血淋巴细胞和巨噬细胞的补充。免疫功能的紊乱能够产生T抑制细胞或因子[33],它们能够进一步损害免疫应答。已发现HIV包膜蛋白对免疫细胞有毒害或抑制作用[34]。通过血液循环,这些蛋白可能会阻断淋巴细胞识别或应答外源抗原的能力,并且可能会干扰抗原提呈细胞的功能。 英文
表2.HIV感染引起免疫抑制的机制
直接机制
(1)HIV对 CD4+ 淋巴细胞的杀细胞效应。
(2)被感染的 CD4+ 细胞的功能缺失:
(a)细胞表面蛋白表达减少(比如 IL-2受体,CD4);
(b)减少淋巴因子的产生,如IL-2 或 γ 干扰素。
(3)减少被感染的巨噬细胞的抗原提呈和/或者单核因子的产生;细胞死亡。... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | HIV病毒复制的重新开始可能加快了疾病的发展,因为通过突变或者选择,出现了新的HIV变异体,这些变异体在许多类型细胞中,都是迅速复制达到很高的滴度,并且导致高度的细胞病变[18]。这个观察结果与临床上随着疾病的发展CD4+细胞[46]的缺失增加以及高水平的p25抗原血症[51]有关。然而,疾病的发展首先是由于免疫应答减弱还是最终高致病性HIV株的出现或是两者都有,仍需要进一步研究。 英文
总之,有数据表明HIV感染的阶段可以解释病程的变化(图1)。抗病毒免疫应答的水平,宿主细胞对病毒复制的内在敏感性和病毒株的相对毒性是需要明确的主要变量。现在仍不知道是什么终止了抵抗状态(即触发了疾病进展),但可能是多因素的,包括抗淋巴细胞抗体,激活... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | (2)被感染细胞是病毒传播的主要源泉,病毒能够通过细胞之间的接触进行传播。
(3)感染细胞处于潜伏状态,表达少量的病毒抗原,这些细胞能够被抗病毒应答所识别和消除吗?
(4)HIV传播发生在宿主的特定部位(如直肠)。这些部位的免疫应答可对病毒起到预防作用。
(5)几个独立的HIV血清型和亚型能被鉴定。能通过一种方法全部控制吗?
(6)部分HIV蛋白类似于正常的细胞蛋白,免疫自身诱导自身抗体。
(7)疫苗可能会产生加强HIV感染的抗体。
英文
作者进行的研究得到了加利福尼亚州立大学艾滋病研究小组、美国艾滋病研究基金会和美国国家卫生研究院的支持。我还要感谢利维、齐格勒、郑迈耶、埃文斯、霍姆西、霍克西、梁、麦格拉思和沃克博士对... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | THE antibodies responsible for human immediate hypersensitivity belong to the IgE isotype1. The most salient feature of IgE is its capacity to bind to mast cell and polymorphonuclear basophil membranes through receptors with high affinity2. Human basophils are specifically challenged by immunological stimuli such as al... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 1×10120 (to give 2.2×10–126 M th in the assay) and similar results were obtained (Fig. 1b). Degranulation induced by high dilutions of anti-IgE antiserum was observed in ten experiments on the full range of dilutions down to 1×1060, when at least 70 similar results were obtained at one or the other part of the high dil... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Fig. 1. Human basophil degranulation induced either by anti-IgE antiserum (●) diluted tenfold from 1×102 down to 1×1060 (a) or hundredfold down to 1×10120 (b) or by anti-IgG antiserum (○) diluted hundredfold from 1×102 down to 1×10120 (representatives of at least 10 experiments for anti-IgE and 4 experiments for anti-I... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | basophils) were counted under a microscope using a Fuchs-Rosenthal haemocytometer. The percentage of basophil degranulation was calculated using the following formula: Basophil no. in control–basophil no. in sample/basophil no. in control×100. Between 60 and 120 basophils were counted in cell suspensions from control w... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Two further blind experiments were performed using the usual dilution procedure: of the 12 tubes used in the first experiment (Table 2), 2 tubes contained goat anti-human antiserum IgE at 1×102 and 1×103 dilutions, 6 tubes contained dilutions from 1×1032 to 1×1037, and 4 tubes buffer-HSA alone. The tubes were then rand... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Blind experiments and dilution protocols as in Table 1. –, Lack of strained bands. ND, not determined. A faint band corresponding to IgG appeared after reduction by 2-mercaptoethanol.
* Basophil degranulation tests I, II, III were performed using 3 different blood samples (see Fig. 1). Percentage basophil degranulation... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | al., unpublished results). 中文
Using the molecular weight of immunoglobulins and Avogadro’s number, we calculate that less than one molecule of antibody is present in the assay when anti-IgE antiserum is diluted to 1×1014 (corresponding to 2.2×10–20 M). But in the experiments reported here we have detected significant b... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | These filtration and ionexchange experiments demonstrated that the activity of the antiserum at high dilution cannot result from contamination of the highly diluted solution with the starting material. They showed, in addition, that the high-dilution activity does not present in space the steric conformation of an IgG ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | independent of the nature of the starting molecule. 中文
Therefore we propose that none of the starting molecules is present in the dilutions beyond the Avogadro limit and that specific information must have been transmitted during the dilution/shaking process. Water could act as a “template” for the molecule, for exampl... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | The precise nature of this phenomenon remains unexplained. It was critical that we should first establish the reality of biological effects in the physical absence of molecules. The entities supporting this “metamolecular” biology can only be explored by physical investigation of agitation causing interaction between t... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | † Department of Animal Sciences, Faculty of Agriculture, PO Box 12, The Hebrew University of Jerusalem, Rehovot 76100, Israel
‡ Department of Internal Medicine, Infectious Diseases and Immunopathology, University of Milano, Ospedale Maggiore Policlinico, Milano, Italy
§ Departments of Zoology and Physiology, Ramsay Wri... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 英文
当人的多形核嗜碱性粒细胞——一种表面表达E型免疫球蛋白(IgE)抗体的白细胞,遇到抗IgE抗体时,它们会释放细胞内颗粒中的组胺,并改变自身的染色特性。后者可以通过使用不同稀释倍数的抗IgE抗体(1×102 ~ 1×10120倍稀释)来证实;在这个范围里,即使最大稀释度时已经无法测算抗IgE分子,也可以观察到40%~60%嗜碱性粒细胞脱颗粒的一系列峰。由于只有在伴随剧烈摇动的稀释中才能观察到这些现象,因此生物信息的传递可能与水的分子结构有关。 英文
造成人速发型超敏反应的抗体属于IgE同种型[1]。IgE最突出的特点是它能够通过高亲和力的受体结合到肥大细胞和嗜碱性多形核粒细胞的膜上[2]。在过敏原或抗IgE抗血清(可以与细胞... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 假设IgG分子的分子量为150,000,那么1×1060和1×10120倍稀释液中分别为2.2×10–66 M(th)和2.2×10–126 M(th)。用肝素(1 U/ml)和2.5 mM EDTA–Na4/2.5 mM EDTA–Na2混合物(终浓度)作为抗凝血剂,从健康受试者身上采集20 ml静脉血,静置沉淀。两次离心收集富含白细胞的血浆(400g,10分钟),最后用HEPES缓冲蒂罗德液重悬。在已加入10 μl CaCl2(终浓度为5 mM)和10 μl IgE或IgG抗血清稀释液的微量滴定板的小孔底部,加入细胞悬液(10 μl)。对照孔中加入10 μl CaCl2和10 μl蒂罗德液,但不加抗IgE或抗IgE抗血清稀释液。... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 英文
表3.在不含HSA的蒂罗德液中比较免疫球蛋白引起的嗜碱性粒细胞脱颗粒与稀释液的抗IgE活性
*未进行双盲编码的阳性对照的嗜碱性粒细胞脱颗粒和(或)凝胶电泳实验。
ND,表示未检出。 英文
图2.凝胶电泳(7%~15%聚丙烯酰胺,银染):1~5为双盲实验中a、c、e、h、m、p的比对标准。1道为凝胶电泳的标准分子量;2道为加了人血清白蛋白的单克隆抗体IgG;3道为不含人血清白蛋白的蒂罗德液;4道为抗IgE的1×102倍稀释液;5道为1×103倍稀释液。双盲测定样品:a和c是蒂罗德液;e为抗IgE的1×1036倍稀释液;h为抗IgE的1×102倍稀释液;m为抗IgE的1×103倍稀释液;p为抗IgE的1×1035倍稀释液。 英... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 目前我们只能基于这种高倍稀释液的特殊活性进行推断。我们确认:(1)这种活性是在严格的实验条件下被发现的,例如由4个国家的6个实验室参与的双盲实验;(2)正如此前证明的只有羊抗血清(IgG)抗人IgE而不是羊抗血清(IgG)抗人IgG才能够引起这种现象,说明这种活性对首次引入的配体是特异性的。如果传统浓度范围内不能引发嗜碱性粒细胞脱颗粒,那么高倍稀释液也不行,所以高低倍抗IgE稀释液的活性是存在联系的。高倍稀释的组胺可以抑制IgE依赖的嗜碱性粒细胞脱颗粒,而其羧基化的前体组氨酸则不行。最后,当细胞悬液中的特定离子被去除后,高倍稀释液的离子载体将不能发挥作用(博韦,未发表的结果);(3)我们使用了6种生物化学的和物理的探针证明高倍稀释液... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | THE remarkable claims made in Nature (333,816;1988) by Dr Jacques Benveniste and his associates are based chiefly on an extensive series of experiments which are statistically ill-controlled, from which no substantial effort has been made to exclude systematic error, including observer bias, and whose interpretation ha... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Our visit and investigation were preconditions for the publication of the original article. We acknowledge that we are an oddly constituted group. One of us (J.R.) is a professional magician (and also a MacArthur Foundation fellow) whose presence was originally thought desirable in case the remarkable results reported ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | laboratory. We are sorry. 中文
What follows is a narrative account of our visit and a summary of our conclusions. 中文
Our investigations concentrated exclusively on the experimental system on which the publication was based. During our week in Paris, we resisted several proffered opportunities to examine other systems in ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | acidic solution of toluidine blue, which stains intact but not degranulated basophils red, is added and the numbers of recognizable basophils counted on a haemocytometer slide. Anti-IgG, which does not degranulate basophils, is used as a control. 中文
We were surprised to learn that the experiments do not always “work”. ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | that the graphs then reach a series of three or four further peaks with increasing dilution. 中文
Fig. 1. A demonstration degranulation, the first of the three open experiments. 中文
These are the successive peaks of activity said in the original article to occur in a periodic fashion, and whose position was said to be r... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Ironically, he is himself one of the three authors of a paper published in 1981, in which just this issue had been addressed in a superficially similar situation (Petoit, J. F., Sainte-Laudy, J. & Benveniste, J. Ann. Biol. clin. 39, 355; 1981), and which appears to be the justification of the dotted line drawn at about... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | In these circumstances, it is natural that we should eagerly have accepted Benveniste’s invitation to devise a blind experiment. We set out to devise a procedure that would be watertight. We asked that three samples of blood should be run. The serial dilutions would be prepared by Dr Davenas, secretly coded by us befor... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | We also arranged a second step of coding just before the slides were counted. One of us (W.W.S.) took responsibility for pipetting, after securing the agreement of Davenas and Benveniste that his technique was satisfactory. Both the laboratory procedures and the codes themselves were recorded on video tape. The plates ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Others working in this field recognize the difficulty of counting basophils (roughly 1 in 100 among leukocytes), preferring instead to measure the histamine released on degranulation. This practice is not followed at INSERM 200 because, we were told, of previous failure to record histamine release (as distinct from the... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | So do the numbers make sense? Six numbers into the record of the first plate to be read, Benveniste said “that patient isn’t degranulating, try another”. So we did—first the parallel readings by Dr Beauvais, then the remaining two experiments. In the event, the results of all three experiments were similar. The anti-Ig... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | The design of the experiments hardly matches the nature of their interpretation. For example, one would have thought that counting wells at least in duplicate would have been an elementary precaution against gross errors. The second of our strictly blinded experiments seems to be one of the few in which something of th... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | duplicate readings by the same individual, but the magnitide of the effect in this case calls into question the validity of the readings. This artefact is nevertheless not apparent in the blinded duplicated readings. 中文
Fig. 3. Records for the first two blind experiments (5–7 inclusive). showing sampling noise only be... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | high-dilution work pervades the laboratory, as epitomized by the suggestion that decanting diluted solution from one tube to another might spoil the effect and the report that the repeated serial dilution by factors of three and seven (rather than ten) always yields negative results. 中文
Collaborations
We have not been ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Since then, there have been two developments in Israel— a series of experiments carried out independently of Benveniste’s laboratory and a further blinded experiment. Data from the latter are unfortunately not available. Maitre Simart, a legal official at Clamart who held the codes, is said not to have had time to deco... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | taken. 中文
Eventually, there was no more to say. We shook hands all round, sped past the common-room filled with champagne bottles destined now not to be opened and into the lens of a news agency photographer summoned for the happier event. 中文
(334, 287-290; 1988)
John Maddox, James Randi & Walter W. Stewart.
高倍稀释实验的错觉... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 在我们访问巴黎的一周时间内,我们多次拒绝了对方提供的检查其他系统的机会,据说在那些系统中经过高倍稀释后分子的生物学效应仍未消失。 英文
这个实验系统是从一个检测人们对特定过敏原的易感性的实验演化而来的。其指导原则是血源性过敏原可以与嗜碱性粒细胞等白细胞相互作用并发挥效应,引起这些细胞脱颗粒,释放细胞质颗粒物中的组胺和其他活性物质,从而引起哮喘和枯草热的症状。 英文
这些过敏反应(至少部分)是由附着在嗜碱性粒细胞(血液中)或肥大细胞(组织中)表面的IgE分子介导的。一般来讲,脱颗粒过程由锚定于细胞表面的IgE分子与抗原相互作用而触发,但是抗IgE抗体也可以引发相同的效应。将人IgE分子注射到其他物种的动物中便可以得到抗IgE抗体。(I... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 在这篇文章中,他们认为应在完整嗜碱性粒细胞的脱颗粒百分比的20%处(对应两个标准差)划一条点线作为判据,点线之下为可信的读数。 英文
那篇文章专门研究了白细胞悬浮液通过表面IgE分子与抗原相互作用后,采样误差(不是别的误差)对检测脱颗粒后完整嗜碱性粒细胞的影响。即使现在,在克拉马尔实验室,也仍然规定要测量两个对照样品。此外,这篇文章还给出了用于验证两个对照值之间的差异是否具有统计学显著性(p<0.05)的检验方法。这使得那些通过观察嗜碱性粒细胞脱颗粒的情况检测过敏反应的研究人员开始重新设计他们的实验。 英文
在INSERM 200,对于此类问题似乎存在一个不那么正式的处理方法。当实验组的读值比对照组还要高的时候,实验员通常会以第一次... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 不过事实证明他的预测是完全错误的。 英文
这个时候我们问大家对此次实验的执行是否有疑问,不过没有得到回应。当我们问到如何看待“两名观测人员虽然都记录到了脱颗粒的峰值,但是对应的是不同的稀释倍数”这个问题时,邦弗尼斯特认为这仍证明脱颗粒实验是成功的。 英文
打开密封的信封是兰迪的拿手好戏。在把粘在天花板上的编号的透明胶带除去时,他发现信封的封口已经自己展成了令人惊讶的直角。通过检查包在外面的铝箔,他确认编号并没有被人偷看。然后我们开始解码——一个人把编号唱给另一个人。 英文
那么结果与预期相符合么?读取了第一块板测的6个样品的脱颗粒情况之后,邦弗尼斯特说“这个病人的血样不能发生脱颗粒,试试另一个”。于是我们照做了——首先是博韦博士对第... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 考虑到克拉马尔的研究人员对“高倍稀释的抗血清可以引发嗜碱性粒细胞脱颗粒”这个实验现象真实性以及潜在的重要性都很有信心,我们对他们缺乏重复实验和双盲实验的意识而感到迷惑。 英文
■ 这个实验室不能客观地评价实验中不支持自己假说的数据。从实验通常被描述为“成功”的和“失败”的诸多事实已经证明了这一点。当得到阳性的结果时,人们会说这个实验“奏效”了;而对于好几次被认为“阴性”的结果,用我们提出的若干推测而非实验证据来解释。这个实验室还很流行高倍稀释效应这样的民间传说,并且还认为把稀释后的溶液从一个试管中倒入另一个试管会破坏其疗效,以及报告称先后稀释103倍和107倍(而不是1010倍)的抗血清总是会产生阴性的结果。 英文
合作
虽然我们很... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 英文
(张锦彬 翻译;秦志海 审稿)
New Semiconductor Device Physics in Polymer Diodes and Transistors
J. H. Burroughes et al.
Editor’s Note
Carbon-based polymers (plastics) had been long regarded as electrical insulators. But in the 1970s, Japanese chemist Hideki Shirakawa discovered an electrically conducting form of polyacetylene. ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | mobilities when doped2. Despite the considerable progress made in the past decade towards an understanding of the electronic properties of conjugated polymers, there has been relatively little work on their use as the active component in semiconductor device structures. There are several reasons for this, the most impo... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | further. We have investigated a range of unipolar devices: Schottky-barrier diodes, MIS (metal–insulator–semiconductor) structures and MISFETs. By careful control of the processing, with rigorous exclusion of oxygen, we have been able to get the device performance up to levels respectable enough to learn about the deta... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | reduce the mid-gap optical absorption whereas accumulation or inversion-layer formation should introduce mid-gap states onto previously undistorted chains, increasing the mid-gap optical absorption. We find both qualitative and quantitative agreement with these theoretical predictions. 中文
Fabrication
Thin films of poly... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | MISFET structures. (1) Gold source and drain contacts: n-doped silicon substrate (distributed gate electrode), 2,000 Å silicon dioxide, gold source and drain electrodes (thickness 500 Å, channel length 0.1 mm, channel width 75 mm), polyacetylene film (typically 200 Å). Similar source and drain contacts can also be depo... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | voltage, using the simple depletion model for the voltage dependence of the depletion width. In terms of the measured differential capacitance, C, this may be expressed as
where NA is the acceptor concentration and φ is the built-in potential19. This relation is obeyed well for reverse bias, giving values of NA=9×1015... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | the formation of an accumulation layer. The decrease in measured capacitance for positive voltages reveals the formation of a depletion layer. Saturation of the capacitance sets in for large positive biases, when the depletion layer extends across the polyacetylene film (estimated to be ~1,200 Å in thickness for this d... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Fig. 4. a, IDS versus VDS at values of VGS from –5 to –25 V, for a MISFET with gold source and drain contacts. b, IDS versus VGS at constant VDS (+10 V) for a MISFET with poly n-silicon source and drain contacts, as shown in Fig. 1. 中文
The MISFET shown in Fig. 1 is constructed with n-silicon source and drain contacts,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | As discussed earlier, charge in polyacetylene is stored in “soliton” localized states, which are associated with non-bonding pz mid-gap states. As a result, we expect to see a modulation in the optical properties of the active semiconductor region of these devices with applied bias voltage. The formation of a pair of n... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | polyacetylene. The periodic structure in the modulated transmission spectrum below the band gap is due to the formation of interference fringes (modulation of the finesse of the Fabry-Perot etalon formed by the polyacetylene film). Electro-absorption is seen at energies greater than 1.4 eV, as expected if extra π- and ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | For the low areal soliton concentrations, Na, found in the device structures, the modulation in transmission, ΔT/T, can be expressed as σNa, where σ is the optical cross-section for the dopant-induced mid-gap absorption. The determination of Na is particularly simple for the MIS device driven into accumulation, for whi... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | cm–1 (ref. 15), and for dopant-induced charges, 1,410 cm–1 (ref. 13), and provides information about the chain conformation and degree of conjugation. We were not able to measure the VMT spectrum below 1,000 cm–1 because of a very large absorption peak from SiO2, and we were thus unable to observe the lowest-frequency,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | is of particular importance here since the unoriented films of Durham polyacetylene we have used are known to have straight-chain sequences of no more than 20 or so carbon-carbon bonds10-15. 中文
Optical spectroscopy reveals that charge storage in depletion, inversion or accumulation layers in these polyacetylene devices... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | The electro-optic effects we have demonstrated here are large, and there are obvious areas of technology in which these devices may be exploited. Modulation depths, measured here for a single pass of the light beam through the device, can be readily enhanced, either in multiple-reflection structures (Fabry-Perot etalon... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Rice, M. J. Phys. Lett. 71A, 152-154 (1979).
Orenstein, J. in Handbook on Conducting Polymers (ed. Skotheim, T. J.) 1297 (Dekker, New York, 1986).
Sze, S. M. Physics of Semiconductor Devices, 2nd edn (Wiley-Interscience, New York, 1981).
Rhoderick, E. M. Metal-Semiconductor Contacts (Clarendon Press, Oxford, 1978).
And... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 聚乙炔中耗尽层的形成应该排除非本征掺杂产生的带电孤子。然而积累层和反型层的形成为高分子链的带电提供了新的途径。聚乙炔中孤子形成的最明确的证据是伴随着孤子的振动能级和电子能级的激发,在带隙下出现了附加的光学吸收[18]。对采用杜伦路线制备的聚乙炔而言,其“中间能隙”吸收特征源于孤子的“中间能隙”能级和能带边缘间的跃迁,对于化学掺杂样品来说这个能级大约在1.0 eV[13],而对于光激发电荷来说大约在0.55 eV[15]。因此,我们认为“电荷注入”会改变这些器件中聚乙炔的光学性质;耗尽层将会削弱中间能隙的光吸收,而积累层或反型层的形成将会在之前未变形的链上引入中间能隙态,从而增强中间能隙的光吸收。从定性和定量的角度,我们的发现都与这些... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 电荷积累层、耗尽层和反型层的形成可以通过器件的电容与偏压之间的关系得到验证。测得的电容C是绝缘体电容Ci和半导体活性区域的电容Cd的串联组合,由公式C = CiCd/(Ci + Cd)决定。对于积累层和反型层,Cd很大,C等于绝缘层的几何电容,但如果耗尽层发生移动,C值会变小。聚乙炔MIS结构的电容随偏压变化的曲线如图3所示。与预测类似,在负的栅压下电容趋向于绝缘体的几何电容,这意味着电荷积累层的形成。正电压下测得的电容减小表明形成了耗尽层。在大的正偏压下,当耗尽层扩展穿过聚乙炔薄膜(对这个器件来说,其厚度估计在1,200 Å左右)的时候,电容开始饱和。 英文
图3.MIS结构中0.8 eV处的微分光学透过率∂ln(T)/∂V(虚... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 英文
图6.肖特基二极管电压调制的透过率[T(V)–T(0)]/T(0)随光子能量(Ep)的变化,其中V = –3 V是相对于阻挡接触而言的。 英文
MIS和MISFET结构 对于这一类的结构我们预期低于能带边缘处器件的透过率会降低,原因是在器件驱动时,随着积累层的形成,新的带电孤子被引入到位于绝缘体界面处的聚乙炔链上。0.4 eV至1.2 eV的VMT光谱(图7a)表明负偏压下器件的透过率会降低。在0.8 eV处,ΔT/T的峰值大约为0.64%。如果所有位于高分子–绝缘体界面处的电荷都以类孤子的形式存在,那么在偏压发生变化的时候,VMT信号∂ln(T)/∂V应该与微分电容∂Q/∂V成比例。这种情况如图3所示,图中为∂ln(T)... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | 但是,对电荷积累层和反型层,我们证实了一种新的方法将电荷引入高分子链中,即通过表面电场形成带电孤子–反孤子对进入到原先未变形的链中,如图5所示。 英文
通过器件的外加电压控制带电孤子的密度,从而实现对其光学性质的调制。这为我们提供了一个新的、强有力的光谱方法用以研究半导体器件中活性区的电子结构。通过对比中间能隙处的微分透过率(∂ln(T)/∂V)和微分电容(∂Q/∂V)随偏压的变化,我们发现这两个量是直接对应的,因此所有的位于界面处的电荷都以类孤子态积累于聚乙炔链上。根据光谱分辨的电子和振动吸收特征,我们可以知道这些高分子链在荷电界面上的详细的电子结构,这些结果我们将随后发表。 英文
我们在这里所证实的电光效应是比较强的,基于这些器... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | with genetic markers7. The use of restriction fragment length polymorphisms10 (RFLPs) has made such investigations possible, at least in principle. Here, we report the first use of a complete RFLP linkage map to resolve quantitative traits into discrete Mendelian factors, in an interspecific back-cross of tomato. Apply... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Fig. 1. Frequency distribution for fruit mass, soluble-solids concentration (oBrix, a standard refractometric measure primarily detecting reducing sugars, but also affected by other soluble constituents; 1oBrix is approximately 1% w/w) and pH in the E parental strain and in the back-cross (BC) progeny. The tomatoes wer... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | polymorphism between the E and CL strains. These included 63 RFLPs and five isozyme markers. In addition, the E and CL strains differ in two easily-scored, simply-inherited morphological traits: determinacy (described below) and uniform ripening, controlled by the sp and u genes, respectively. Although a few distal reg... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | average agreed closely with the Mendelian expectation of 75% for a back-cross, values for individual plants ranged from 59% to over 90%. The distribution of the proportion of recurrent-parent genome agrees with the mathematical expectation35,36. The individual with >90% E appears to carry only five fragments from CL (r... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | points. The height of the curve indicates the strength of the evidence (log10 of the odds ratio) for the presence of a QTL at each location—not the magnitude of the inferred allelic effect. The horizontal line at a height of 2.4 indicates the stringent threshold that the lod score must cross to allow the presence of a ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | Methods. The lod score and the maximum likelihood estimate (MLE) of the phenotypic effect at any point in the genome is computed assuming that the distribution of phenotypes in the BC progeny represents a mixture of two normal distributions (of equal variance) with means depending on the genotype at a putative QTL at t... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0305. 《自然》百年科学经典(英汉对照版)(第七卷)(1985-1992).epub | .epub | 41,865,664 | 2025-09-26T19:07:39.767346 | data arising) and the odds ratio (the chance that the data would arise from a QTL with this effect divided by the chance that it would arise given no linked QTL). The lod score, defined as the log10 of the odds ratio, summarizes the strength of evidence in favour of the existence of a QTL with this effect at this posit... | 400套付费套装书 |
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