全文获取类型
收费全文 | 3260篇 |
免费 | 222篇 |
国内免费 | 1篇 |
出版年
2023年 | 13篇 |
2022年 | 7篇 |
2021年 | 49篇 |
2020年 | 35篇 |
2019年 | 49篇 |
2018年 | 71篇 |
2017年 | 54篇 |
2016年 | 98篇 |
2015年 | 177篇 |
2014年 | 180篇 |
2013年 | 210篇 |
2012年 | 283篇 |
2011年 | 253篇 |
2010年 | 153篇 |
2009年 | 151篇 |
2008年 | 211篇 |
2007年 | 200篇 |
2006年 | 153篇 |
2005年 | 156篇 |
2004年 | 162篇 |
2003年 | 155篇 |
2002年 | 89篇 |
2001年 | 70篇 |
2000年 | 74篇 |
1999年 | 60篇 |
1998年 | 16篇 |
1997年 | 22篇 |
1996年 | 22篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 23篇 |
1991年 | 17篇 |
1990年 | 15篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1975年 | 11篇 |
1974年 | 8篇 |
1972年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有3483条查询结果,搜索用时 15 毫秒
91.
92.
Suho Lee Hyunji Moon Gayoung Kim Jeong Hoon Cho Lee Dae-Hee Michael B. Ye Daeho Park 《Molecules and cells》2015,38(7):657-662
Rapid and efficient engulfment of apoptotic cells is an essential property of phagocytes for removal of the large number of apoptotic cells generated in multicellular organisms. To achieve this, phagocytes need to be able to continuously uptake apoptotic cells. It was recently reported that uncoupling protein 2 (Ucp2) promotes engulfment of apoptotic cells by increasing the phagocytic capacity, thereby allowing cells to continuously ingest apoptotic cells. However, the functions of Ucp2, beyond its possible role in dissipating the mitochondrial membrane potential, that contribute to elevation of the phagocytic capacity have not been determined. Here, we report that the anion transfer or nucleotide binding activity of Ucp2, as well as its dissipation of the mitochondrial membrane potential, is necessary for Ucp2-mediated engulfment of apoptotic cells. To study these properties, we generated Ucp2 mutations that affected three different functions of Ucp2, namely, dissipation of the mitochondrial membrane potential, transfer of anions, and binding of purine nucleotides. Mutations of Ucp2 that affected the proton leak did not enhance the engulfment of apoptotic cells. Although anion transfer and nucleotide binding mutations did not affect the mitochondrial membrane potential, they exerted a dominant-negative effect on Ucp2-mediated engulfment. Furthermore, none of our Ucp2 mutations increased the phagocytic capacity. We conclude that dissipation of the proton gradient by Ucp2 is not the only determinant of the phagocytic capacity and that anion transfer or nucleotide binding by Ucp2 is also essential for Ucp2-mediated engulfment of apoptotic cells. 相似文献
93.
Population growth and the subsequent increased demand for food, along with the rise in cost of feed, have led insect feed to be considered as an alternative to conventional animal feed. Insect feed is a sustainable and nutritious option; however, it does carry the risk of lower microbiological safety than conventional feed. Although there is some hesitancy from farmers in adapting insect feed due to fear of market rejection of insect‐fed animals, surveys seem to show positive attitudes of people towards insect feed when they informed of the benefits. Traditional methods of harvesting insects is not a sustainable method of production, and therefore further research will be needed to access appropriate methods of mass‐producing insects without putting a strain on the natural ecosystem. This review discusses the benefits and risks of using insect feed, its acceptance, type of animals that can be fed by insects, and future directions of insect feed. 相似文献
94.
95.
Hana Moon Min Jung Kim Hee Jin Son Hae-Jin Kweon Jung Tae Kim Yiseul Kim Jaewon Shim Byung-Chang Suh Mee-Ra Rhyu 《PloS one》2015,10(5)
Transient receptor potential ankyrin1 (TRPA1) and transient receptor potential vanilloid 1 (TRPV1) are members of the TRP superfamily of structurally related, nonselective cation channels and mediators of several signaling pathways. Previously, we identified methyl syringate as an hTRPA1 agonist with efficacy against gastric emptying. The aim of this study was to find hTRPA1 and/or hTRPV1 activators in Agastache rugosa (Fisch. et Meyer) O. Kuntze (A.rugosa), commonly known as Korean mint to improve hTRPA1-related phenomena. An extract of the stem and leaves of A.rugosa (Labiatae) selectively activated hTRPA1 and hTRPV1. We next investigated the effects of commercially available compounds found in A.rugosa (acacetin, 4-allylanisole, p-anisaldehyde, apigenin 7-glucoside, L-carveol, β-caryophyllene, trans-p-methoxycinnamaldehyde, methyl eugenol, pachypodol, and rosmarinic acid) on cultured hTRPA1- and hTRPV1-expressing cells. Of the ten compounds, L-carveol, trans-p-methoxycinnamaldehyde, methyl eugenol, 4-allylanisole, and p-anisaldehyde selectively activated hTRPA1, with EC50 values of 189.1±26.8, 29.8±14.9, 160.2±21.9, 1535±315.7, and 546.5±73.0 μM, respectively. The activities of these compounds were effectively inhibited by the hTRPA1 antagonists, ruthenium red and HC-030031. Although the five active compounds showed weaker calcium responses than allyl isothiocyanate (EC50=7.2±1.4 μM), our results suggest that these compounds from the stem and leaves of A.rugosa are specific and selective agonists of hTRPA1. 相似文献
96.
Simon D. S. Fraser Grant Aitken Maarten W. Taal Jennifer S. Mindell Graham Moon Julie Day Donal O’Donoghue Paul J. Roderick 《PloS one》2015,10(2)
BackgroundChronic kidney disease (CKD) diagnosis relies on glomerular filtration rate (eGFR) estimation, traditionally using the creatinine-based Modification of Diet in Renal Disease (MDRD) equation. The Chronic Kidney Disease Epidemiology Collaboration (CKDEPI) equation performs better in estimating eGFR and predicting mortality and CKD progression risk. Cystatin C is an alternative glomerular filtration marker less influenced by muscle mass. CKD risk stratification is improved by combining creatinine eGFR with cystatin C and urinary albumin to creatinine ratio (uACR). We aimed to identify the impact of introducing CKDEPI and cystatin C on the estimated prevalence and risk stratification of CKD in England and to describe prevalence and associations of cystatin C.LimitationsCross sectional study, single eGFR measure, no measured (‘true’) GFR.ConclusionsIntroducing the CKDEPI equation and targeted cystatin C measurement reduces estimated CKD prevalence and improves risk stratification. 相似文献
97.
Sun Ja Kim Yaser Hassan Dewir Heung Kyu Moon 《Journal of plant biochemistry and biotechnology.》2011,20(2):241-248
A suitable bioreactor system for large scale embryo-to-plantlets conversion of Kalopanax septemlobus was established. In temporary immersion with net (TIN) bioreactor, 85% of embryos successfully produced plantlets whereas in continuous immersion with net (CIN) bioreactor, only conversion rate of 29.3% was obtained. Embryos cultured in TIN bioreactor produced more vigorous plantlets in terms of fresh weight, height, root length, roots and leaves quantity. In CIN bioreactor, Kalopanax plantlets showed high malondialdehyde (MDA) content and increased activities of reactive oxygen species (ROS)-processing enzymes, such as ascorbate peroxidase (APX) and glutathione reductase (GR) indicating the occurrence of oxidative stress. However, superoxide dismutase (SOD) and catalase (CAT) showed similar activities in plantlets grown in different bioreactors. Kalopanax plantlets grown in both TIN and CIN bioreactors were harvested and transferred to greenhouse for their acclimatization. Plantlets grown in CIN bioreactor exhibited low survival rate (75.8%) compared to those grown in TIN bioreactor (100%). MDA content decreased with progression of acclimatization indicating a decrease in oxidative stress. However, MDA level in CIN derived plantlets was higher than TIN derived plantlets. In TIN derived plantlets, an increase in SOD and GR activities were observed after 1 week and thereafter decreased. CAT activity decreased while APX activity started to increase after 1 week of acclimatization. The results indicated that Kalopanax plantlets were able to overcome oxidative stress mainly through SOD activity. However, levels of antioxidant enzyme activities were higher in CIN derived plantlets than TIN derived plantlets. Kalopanax plantlets obtained from TIN bioreactor performed better during the acclimatization phase and showed higher survival rate than material obtained on CIN bioreactor or conventional culture systems. 相似文献
98.
99.
Jong Pil Park Jin Hee Kim Moon Ki Park Jong Won Yun 《Biotechnology and Bioprocess Engineering》2011,16(6):1065-1076
Many classes of bioactive drug-like molecules derived from traditional herbal plants are becoming attractive as alternative
medicines for the treatment of severe chronic diseases such as cancer and obesity. A set of chemically synthesized drugs that
is capable of both inhibiting cancer growth and reducing body weight for treatment of obesity have severe side effects including
nausea, vomiting, diarrhea as well as producing increased blood pressure and headache, respectively. For decades, drug candidates
from herbal plants have been considered as potential therapeutic agents because they are generally safer, less toxic, and
have fewer lethal side effects than chemically synthesized or semi-synthetic drugs. Understanding the key factors affecting
pharmacological effects and clinical outcomes has been a critical theme of natural product research. However, standardized
sample preparation methods, well-controlled scientific studies, and validation studies are needed before herbal therapeutics
can be introduced into the global market. This review will address the current advances in using traditional herbal plants,
including the pharmacological effects and the challenges faced during the development of new drugs. The safety issues associated
with toxicity and the effectiveness of the herbs in specific diseases such as cancer and obesity are also discussed. 相似文献
100.
Soo-A Jung Yong-Man Park Seung-Woo Hong Jai-Hee Moon Jae-Sik Shin Ha-Reum Lee Seung-Hee Ha Dae-Hee Lee Jeong Hee Kim Seung-Mi Kim Jeong Eun Kim Kyu-pyo Kim Yong Sang Hong Eun Kyung Choi Jung Shin Lee Dong-Hoon Jin TaeWon Kim 《The Journal of biological chemistry》2015,290(16):9974-9985
YM155, which blocks the expression of survivin, a member of the inhibitor of apoptosis (IAP) family, induces cell death in a variety of cancer types, including prostate, bladder, breast, leukemia, and non-small lung cancer. However, the mechanism underlying gastric cancer susceptibility and resistance to YM155 is yet to be specified. Here, we demonstrate that cIAP1 stability dictates resistance to YM155 in human gastric cancer cells. Treatment of human gastric cancer cells with YM155 differentially induced cell death dependent on the stability of cIAP1 as well as survivin. Transfection with cIAP1 expression plasmids decreased cell sensitivity to YM155, whereas knockdown of endogenous cIAP1 using RNA interference enhanced sensitivity to YM155. In addition, double knockdown of survivin and cIAP1 significantly induced cell death in the YM155-resistant cell line, MKN45. We also showed that YM155 induced autoubiquitination and proteasome-dependent degradation of cIAP1. Surprisingly, survivin affected the stability of cIAP1 through binding, contributing to cell sensitivity to YM155. Thus, our findings reveal that YM155 sensitizes human gastric cancer cells to apoptotic cell death by degrading cIAP1, and furthermore, cIAP1 in gastric cancer cells may act as a PD marker for YM155 treatment. 相似文献