全文获取类型
收费全文 | 746篇 |
免费 | 48篇 |
出版年
2023年 | 10篇 |
2022年 | 12篇 |
2021年 | 25篇 |
2020年 | 12篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 8篇 |
2016年 | 14篇 |
2015年 | 23篇 |
2014年 | 41篇 |
2013年 | 52篇 |
2012年 | 56篇 |
2011年 | 56篇 |
2010年 | 21篇 |
2009年 | 25篇 |
2008年 | 43篇 |
2007年 | 35篇 |
2006年 | 30篇 |
2005年 | 29篇 |
2004年 | 44篇 |
2003年 | 32篇 |
2002年 | 23篇 |
2001年 | 23篇 |
2000年 | 18篇 |
1999年 | 19篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 7篇 |
1992年 | 10篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1983年 | 2篇 |
1976年 | 3篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1966年 | 3篇 |
1959年 | 1篇 |
1953年 | 1篇 |
1950年 | 1篇 |
1937年 | 1篇 |
1936年 | 2篇 |
1935年 | 4篇 |
排序方式: 共有794条查询结果,搜索用时 203 毫秒
281.
Erin R. Aho Jing Wang Rocco D. Gogliotti Gregory C. Howard Jason Phan Pankaj Acharya Jonathan D. Macdonald Ken Cheng Shelly L. Lorey Bin Lu Sabine Wenzel Audra M. Foshage Joseph Alvarado Feng Wang J. Grace Shaw Bin Zhao April M. Weissmiller Lance R. Thomas William P. Tansey 《Cell reports》2019,26(11):2916-2928.e13
282.
283.
284.
Jaydeep Chaudhuri Avik Acharya Chowdhury Nabendu Biswas Anirban Manna Saurav Chatterjee Tulika Mukherjee Utpal Chaudhuri Parasuraman Jaisankar Santu Bandyopadhyay 《Apoptosis : an international journal on programmed cell death》2014,19(1):135-148
Mammalian target of rapamycin (mTOR) is a central kinase that regulates cell survival, proliferation and translation. Reactive oxygen species (ROS) are second messengers with potential in manipulating cellular signaling. Here we report that two ROS generating phytochemicals, hydroxychavicol and curcumin synergize in leukemic cells in inducing enhanced apoptosis by independently activating both mitogen activated protein kinase (MAPK) (JNK and P38) and mTOR pathways. Low level transient ROS generated after co-treatment with these phytochemicals led to activation of these two pathways. Both mTOR and MAPK pathways played important roles in co-treatment-induced apoptosis, by knocking down either mTOR or MAPKs inhibited apoptosis. Activation of mTOR, as evident from phosphorylation of its downstream effector eukaryotic translation initiation factor 4E-binding protein 1, led to release of eukaryotic translation initiation factor 4E (eIF4E) which was subsequently phosphorylated by JNK leading to translation of pro-apoptotic proteins Bax and Bad without affecting the expression of anti-apoptotic protein Bcl-xl. Our data suggest that mTOR and MAPK pathways converge at eIF4E in co-treatment-induced enhanced apoptosis and provide mechanistic insight for the role of mTOR activation in apoptosis. 相似文献
285.
286.
Azadirachta indica, a plant used widely in Ayurveda, has been reported to have anti-inflammatory, immunomodulatory and adaptogenic properties. The present study evaluates its hepatoprotective role. Fresh juice of tender leaves of Azadirachta indica (200 mg/kg body wt. p.o.) inhibited paracetamol (2 g/kg body wt. p.o.)-induced lipid peroxidation and prevented depletion of sulfhydryl groups in liver cells. There was an increase in serum marker enzymes of hepatic damage (aspartate transaminase, alanine transaminase and alkaline phosphatase) after paracetamol administration. Azadirachta indica pretreatment stabilized the serum levels of these enzymes. Histopathological observations of liver tissues corroborated these findings. 相似文献
287.
The toxic products of the anaerobic bacteria Clostridium botulinum, Clostridium butyricum, Clostridium barati and Clostridium tetani are the causative agents of botulism and tetanus. The ability of botulinum neurotoxins to disrupt neurotransmission, often for prolonged periods, has been exploited for use in several medical applications and the toxins, as licensed pharmaceutical products, now represent the therapeutics of choice for the treatment for several neuromuscular conditions. Research into the structures and activities of botulinum and tetanus toxins has revealed features of these proteins that might be useful in the design of improved vaccines, effective inhibitors and novel biopharmaceuticals. Here, we discuss the relationships between structure, mechanism of action and therapeutic use. 相似文献
288.
Narayan Prasad Koju Ram Chandra Kandel Hari Bhadra Acharya Bed Kumar Dhakal Dinesh Raj Bhuju 《Ecology and evolution》2021,11(14):9198
To contain transmission of COVID‐19, lockdowns or strict restrictions of people''s mobility outside their residences were instituted in a majority of countries worldwide, including Nepal, where the first phase of nationwide lockdown was observed from 24 March to 21 July 2020. This sudden halt in human outdoor activities brought positive and negative impacts on forests and wildlife. We undertook a study to learn the impact of the COVID‐19 lockdown on wildlife and forests in the protected areas (PAs) of Nepal. Between July and September 2020, data on illegal activities recorded by the staff of PAs and also those reported by media were collected and analyzed. Key informant interviews (KII) were done with the park officers and security personnel by virtual communication (telephone, messenger app, and video call) to collect detailed information and for corroboration. The collected data were categorized into four groups: (a) wildlife killed, (b) wildlife injured, (c) arrest incidents related to forest crime, and (d) arrest incidents related to wildlife crime. Data from the fiscal year 2019–2020 were analyzed, comparing before lockdown and after. Among 20 PAs investigated during the lockdown, the study found substantial increases in wildlife death in two PAs, Banke National Park, and Bardia National Park. Similarly, Chitwan National Park (CNP) and Shivapuri Nagarjun National Park (SNNP) witnessed a rise in wildlife poaching. CNP and SNNP are located close to densely populated cities and also have human settlements in their peripheries. Wildlife was sighted freely roaming inside PAs during the lockdown, presumably because the absence of visitors and human activities during the lockdown decreased disturbance. Thus, the wildlife was enjoying the freedom of movement on the one hand, and on the other hand was threatened by poachers, many of whom were laid off from other activities and were taking advantage of the lapse in security. 相似文献
289.
Schizophrenia (SZ) is a mental disorder, which affects the ability of human thinking, memory, and way of living. Manual screening of SZ patients is tedious, laborious and prone to human errors. Hence, we developed a computer-aided diagnosis (CAD) system to diagnose SZ patients accurately using single-channel electroencephalogram (EEG) signals. The EEG signals are nonlinear and non-stationary. Hence, we have used wavelet-based features to capture the hidden non-stationary nature present in the signal. First, the EEG signals are subjected to the the wavelet decomposition through six iterations, which yields seven sub-bands. The norm is computed for each sub-band. The extracted norm features are disseminated to various classification algorithms. We have obtained the highest accuracy of 99.21% and 97.2% using K-nearest neighbor classifiers with ten-fold and leave-one-subject-out cross-validations. The developed single-channel EEG wavelet-based CAD model can help the clinicians to confirm the outcome of their manual screening and obtain an accurate diagnosis. 相似文献
290.