全文获取类型
收费全文 | 5274篇 |
免费 | 626篇 |
国内免费 | 274篇 |
出版年
2024年 | 13篇 |
2023年 | 110篇 |
2022年 | 184篇 |
2021年 | 310篇 |
2020年 | 312篇 |
2019年 | 334篇 |
2018年 | 306篇 |
2017年 | 238篇 |
2016年 | 202篇 |
2015年 | 272篇 |
2014年 | 432篇 |
2013年 | 464篇 |
2012年 | 335篇 |
2011年 | 356篇 |
2010年 | 242篇 |
2009年 | 202篇 |
2008年 | 225篇 |
2007年 | 239篇 |
2006年 | 207篇 |
2005年 | 149篇 |
2004年 | 136篇 |
2003年 | 117篇 |
2002年 | 91篇 |
2001年 | 78篇 |
2000年 | 60篇 |
1999年 | 46篇 |
1998年 | 61篇 |
1997年 | 54篇 |
1996年 | 44篇 |
1995年 | 31篇 |
1994年 | 31篇 |
1993年 | 34篇 |
1992年 | 31篇 |
1991年 | 28篇 |
1990年 | 16篇 |
1989年 | 19篇 |
1988年 | 18篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 14篇 |
1982年 | 13篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有6174条查询结果,搜索用时 31 毫秒
51.
52.
Lev G. Goldfarb Paul Brown Larisa Cervenakova D. Carleton Gajdusek 《Molecular neurobiology》1994,8(2-3):89-97
Genetic study of over 200 cases of Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker disease (GSS), fatal familial insomnia (FFI), and kuru have brought a reliable body of evidence that the familial forms of CJD and all known cases of GSS and FFI are linked to germline mutations in the coding region of the PRNP gene on chromosome 20, either point substitutions or expansion of the number of repeat units. No pathogenic mutations have so far been found in sporadic or infectious forms of CJD, although there are features of genetic predisposition in iatrogenic CJD and kuru. In FFI and familial CJD, clinically and pathologically distinct syndromes that are both linked to the 178Asp→Asn substitution, phenotypic expression is dependent on a polymorphism at codon 129. Synthetic peptides homologous to several regions of PrP spontaneously form insoluble amyloid fibrils with unique morphological characteristics and polymerization tendencies. Peptides homologous to mutated regions of PrP exhibit enhanced fibrilogenic properties and, if mixed with the wild-type peptide, produce even more abundant and larger fibrous aggregates. A similar process in vivo may lead to amyloid accumulation and disease, and transmission of “baby fibrils” may induce disease in other hosts. 相似文献
53.
Ilan Hammel Joseph Alroy Vibha Goyal Stephen J. Galli 《Virchows Archiv. B, Cell pathology including molecular pathology》1993,64(1):83-89
The effect of lysosomal storage diseases on the ultrastructure of human mast cells has not previously been reported. Indeed,
there has been little published evidence indicating that mast cells contain typical lysosomes. However, mast cell cytoplasmic
granules contain hydrolases similar to those found in lysosomes, but which differ from lysosomal hydrolases in exhibiting
optimal activity at higher pH. We therefore examined by transmission electron microscopy the dermal mast cells in 58 biopsies
of patients exhibiting 1 of 29 different lysosomal storage diseases. We found mast cells containing abnormal lysosomes in
16 of these disorders. In 6 of these 16 diseases, the mast cells' cytoplasmic granules appeared normal. These observations
indicate that human mast cells can contain lysosomes, and provide evidence that the enzymes affected by lysosomal storage
diseases are active in mast cells. 相似文献
54.
本文对11例肺癌患者胸水13种游离氨基酸作了分析,并与28例正常人血浆游离氨基酸水平作了对照,结果表明:肺癌患者胸水的必需及非必需氨基酸普遍高于正常人血浆游离氨基酸,但其胸水谷氨酰胺水平则明显低于正常人血浆水平。 相似文献
55.
Protein liquid-liquid phase separation drives the dynamic assembly of membraneless organelles for fulfilling different physiological functions. Under diseased condition, protein may undergo liquid-to-solid condensation to form pathological amyloid aggregates closely associated with neurodegenerative diseases. Chemical probe serves as an important chemical tool not only for exploring the basic principle of the dynamic assembly of different protein condensates in vitro and in cell but also for clinical diagnosis and therapeutics of the related diseases. In this review, we first introduce chemical probes to image and regulate protein condensates. Then, we summarized three different categories of chemical probes including general amyloid dye, selective positron emission tomography tracer, and disaggregating binder, which feature distinct interaction pattern and activity upon binding to different pathological amyloid fibrillar aggregates. Next, we discuss the development of chemical probes for tracking protein amorphous aggregates in cells. Finally, we point out future direction in expanding the probes’ chemical space and applications. 相似文献
56.
Anatoly M. Malygin Alexander A. Redjko Olga N. Pogodina Nina A. Karaseva Yuri F. Koval' Tuomo Timonen 《Cancer immunology, immunotherapy : CII》1993,36(1):61-64
The prognostic value of peripheral blood non-MHC-restricted cytotoxicity against the myeloid leukaemic line K562 in lung cancer patients was studied. At the time of diagnosis and before operation, 57 patients with lung cancer were tested for cytotoxicity and subsequently followed for up to 4 years. In addition, 145 lung cancer patients, 30 patients with non-neoplastic lung diseases and 76 healthy donors were tested for cytotoxicity without the follow-up, in order to correlate the stage of lung cancer and the growth rate of tumours to the level of non-MHC-restricted cytotoxicity. On average, lung cancer patients had similar non-MHC-restricted cytotoxicity to the controls. However, patients with stage II–IV diseases showed an impaired activity, stages III and IV differing significantly from the controls. This result shows that the decline in natural killer (NK) activity is associated with tumour burden. Patients with slowly growing neoplasms had stronger cytotoxic activity than patients with fast or moderately progressing disease. In the follow-up study, the whole material of 57 patients showed only a slight correlation between cytotoxicity and survival: 42% of the patients with strong activity survived for more than 2.5 years, whereas 6% of the patients with weak activity did so. In stage I patients there was no correlation between cytotoxicity and survival, nor was there a correlation in patients with stages II–IV of the disease. Hence, in our group of patients the determination of cytotoxicity preoperatively yielded no prognostic information beyound that already available from staging. However, those stage II–IV patients that survived for 1 year or more after the diagnosis and cytotoxicity tests, showed a significant correlation between cytotoxicity and survival. 相似文献
57.
脑桥呼吸调整中枢向中缝大核下行投射的研究 总被引:1,自引:0,他引:1
实验在23只苯巴比妥钠麻醉(i.p.30mg/kg)的成年猫上进行。在脑桥呼吸调整中枢(NPBM-KF)共记录到67个单位放电可被电刺激中缝大核(NRM)所逆行兴奋。其中有7个单位为呼吸相关性单位(吸气性6、呼气性1),占脑桥87个呼吸相关性单位总数的8%。逆行兴奋潜伏期在0.4—2.5ms之间,平均1.2ms。中缝大核内微量注入麦角辣根过氧化酶(WGA-HRP)后在NPBM-KF区观察到大量HRP标记神经元。本实验结果表明,发自脑桥呼吸调整中枢神经元的轴突可投射到中缝大核。这一投射通路可能与呼吸及痛觉调节有关。 相似文献
58.
59.
Sally Badawi Feda E. Mohamed Divya Saro Varghese Bassam R. Ali 《Traffic (Copenhagen, Denmark)》2023,24(8):312-333
Endoplasmic reticulum-associated protein degradation (ERAD) is a stringent quality control mechanism through which misfolded, unassembled and some native proteins are targeted for degradation to maintain appropriate cellular and organelle homeostasis. Several in vitro and in vivo ERAD-related studies have provided mechanistic insights into ERAD pathway activation and its consequent events; however, a majority of these have investigated the effect of ERAD substrates and their consequent diseases affecting the degradation process. In this review, we present all reported human single-gene disorders caused by genetic variation in genes that encode ERAD components rather than their substrates. Additionally, after extensive literature survey, we present various genetically manipulated higher cellular and mammalian animal models that lack specific components involved in various stages of the ERAD pathway. 相似文献
60.
Pravin Hivare Kratika Mujmer Gitanjali Swarup Sharad Gupta Dhiraj Bhatia 《Traffic (Copenhagen, Denmark)》2023,24(10):434-452
Endocytosis is the fundamental uptake process through which cells internalize extracellular materials and species. Neurodegenerative diseases (NDs) are characterized by a progressive accumulation of intrinsically disordered protein species, leading to neuronal death. Misfolding in many proteins leads to various NDs such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and other disorders. Despite the significance of disordered protein species in neurodegeneration, their spread between cells and the cellular uptake of extracellular species is not entirely understood. This review discusses the major internalization mechanisms of the different conformer species of these proteins and their endocytic mechanisms. We briefly introduce the broad types of endocytic mechanisms found in cells and then summarize what is known about the endocytosis of monomeric, oligomeric and aggregated conformations of tau, Aβ, α-Syn, Huntingtin, Prions, SOD1, TDP-43 and other proteins associated with neurodegeneration. We also highlight the key players involved in internalizing these disordered proteins and the several techniques and approaches to identify their endocytic mechanisms. Finally, we discuss the obstacles involved in studying the endocytosis of these protein species and the need to develop better techniques to elucidate the uptake mechanisms of a particular disordered protein species. 相似文献