全文获取类型
收费全文 | 2274篇 |
免费 | 302篇 |
国内免费 | 2篇 |
出版年
2023年 | 11篇 |
2021年 | 55篇 |
2020年 | 45篇 |
2019年 | 37篇 |
2018年 | 54篇 |
2017年 | 40篇 |
2016年 | 82篇 |
2015年 | 127篇 |
2014年 | 122篇 |
2013年 | 127篇 |
2012年 | 128篇 |
2011年 | 113篇 |
2010年 | 81篇 |
2009年 | 84篇 |
2008年 | 92篇 |
2007年 | 130篇 |
2006年 | 94篇 |
2005年 | 86篇 |
2004年 | 70篇 |
2003年 | 67篇 |
2002年 | 88篇 |
2001年 | 77篇 |
2000年 | 65篇 |
1999年 | 61篇 |
1998年 | 28篇 |
1997年 | 31篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 27篇 |
1993年 | 12篇 |
1992年 | 53篇 |
1991年 | 36篇 |
1990年 | 35篇 |
1989年 | 43篇 |
1988年 | 20篇 |
1987年 | 29篇 |
1986年 | 27篇 |
1985年 | 25篇 |
1984年 | 37篇 |
1983年 | 22篇 |
1982年 | 25篇 |
1981年 | 18篇 |
1980年 | 8篇 |
1979年 | 12篇 |
1978年 | 18篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 14篇 |
1970年 | 8篇 |
排序方式: 共有2578条查询结果,搜索用时 31 毫秒
81.
82.
In a study of Malaysians of different racial groups, 1,510 sera (908 from Malays, 371 from Chinese and 231 from Indians) were identified for their protease inhibitor (Pi) types. The gene frequencies for the alleles PiM, PiS and PiX in Malays were, respectively, 0.979, 0.015, and 0.007. In Chinese, the frequencies were 0.981, 0.019 and 0.000, and in Indians they were 0.976, 0.24, and 0.000. It is interesting that the usually rare PiX type is found in appreciable frequency in the Malays. Two different types with unusual behavior and obscure origin were also found. 相似文献
83.
Summary A dysmorphic female born with partial trisomy of the proximal segment of the long arm of chromosome 14 had 47 chromosomes. The extra one was acrocentric, smaller than the D group, and bigger than the G-chromosome group. By GTG banding it was identified as a deleted chromosome 14, the karyotype being 47,XX,+del 14(q24). Chromosome analysis of the parents was normal. 相似文献
84.
The serum of a patient (Mr. Lat) with the regular blood group A1 B contains an anti-B reacting with all cells having a B antigen except Bx and cis AB. The anti-B reacts at 4 degrees C and occasionally at room temperature as shown by agglutination, absorption-eluction and by thermo-dynamic assays. The antibody is regarded as an irregular autoantibody belonging to the group of the so called "suppressed" or "latent" antibodies. 相似文献
85.
Roberto Tongiani Gino Malvaldi Matteo Lopez Enrico Puccinelli 《Histochemistry and cell biology》1976,47(1):1-21
Summary The orderly organization in a number of discrete classes of weight persists in the hepatocytes during acute and chronic poisoning with thioacetamide and during a prolonged treatment with hydrocortisone, though many striking cytological and structural changes occur in the liver.The number of hepatocyte classes decreases under hydrocortisone treatment and during acute and chronic thioacetamide poisoning, and increases during recovery after acute thioacetamide poisoning and during the late phases of chronic thioacetamide poisoning. This is due to decrements and increments in dry mass of the hepatocytes, which occur by steps, through repeated losses and additions of a constant amount of solids substantially corresponding to the class period.Such a mechanism is similar to that acting in the hepatocyte atrophy due to starvation and in the hepatocyte enlargement occurring during postnatal development. Therefore, the increment and the decrement in dry mass by defined steps takes place in the hepatocytes in both physiological and pathological conditions.This work was supported by a grant of the Consiglio Nazionale delle Ricerche, Rome, Italy. 相似文献
86.
87.
88.
Planta - Both male and female gametes of archegoniates are highly specialized cells surrounded by an extraprotoplasmic matrix rich in AGPs, which are speculated to facilitate development and gamete... 相似文献
89.
E Laplantine E Fontan J Chiaravalli T Lopez G Lakisic M Véron F Agou Alain Israël 《The EMBO journal》2009,28(19):2885-2895
An important property of NEMO, the core element of the IKK complex involved in NF‐κB activation, resides in its ability to specifically recognize poly‐ubiquitin chains. A small domain called NOA/UBAN has been suggested to be responsible for this property. We recently demonstrated that the C‐terminal Zinc Finger (ZF) of NEMO is also able to bind ubiquitin. We show here by ZF swapping and mutagenesis that this represents its only function. While neither NOA nor ZF shows any preference for K63‐linked chains, we demonstrate that together they form a bipartite high‐affinity K63‐specific ubiquitin‐binding domain. A similar domain can be found in two other proteins, Optineurin and ABIN2, and can be freely exchanged with that of NEMO without interfering with its activity. This suggests that the main function of the C‐terminal half of NEMO is to specifically bind K63‐linked poly‐ubiquitin chains. We also demonstrate that the recently described binding of NEMO to linear poly‐ubiquitin chains is dependent on the NOA alone and does not require the presence of the ZF. 相似文献
90.
Shijian Jin Eric M. Fell Lucia Vina‐Lopez Yan Jing P. Winston Michalak Roy G. Gordon Michael J. Aziz 《Liver Transplantation》2020,10(20)
A highly stable phosphonate‐functionalized viologen is introduced as the redox‐active material in a negative potential electrolyte for aqueous redox flow batteries (ARFBs) operating at nearly neutral pH. The solubility is 1.23 m and the reduction potential is the lowest of any substituted viologen utilized in a flow battery, reaching ?0.462 V versus SHE at pH = 9. The negative charges in both the oxidized and the reduced states of 1,1′‐bis(3‐phosphonopropyl)‐[4,4′‐bipyridine]‐1,1′‐diium dibromide ( BPP?Vi ) effect low permeability in cation exchange membranes and suppress a bimolecular mechanism of viologen decomposition. A flow battery pairing BPP?Vi with a ferrocyanide‐based positive potential electrolyte across an inexpensive, non‐fluorinated cation exchange membrane at pH = 9 exhibits an open‐circuit voltage of 0.9 V and a capacity fade rate of 0.016% per day or 0.00069% per cycle. Overcharging leads to viologen decomposition, causing irreversible capacity fade. This work introduces extremely stable, extremely low‐permeating and low reduction potential redox active materials into near neutral ARFBs. 相似文献