全文获取类型
收费全文 | 3453篇 |
免费 | 179篇 |
国内免费 | 7篇 |
出版年
2024年 | 8篇 |
2023年 | 34篇 |
2022年 | 104篇 |
2021年 | 214篇 |
2020年 | 91篇 |
2019年 | 112篇 |
2018年 | 137篇 |
2017年 | 90篇 |
2016年 | 159篇 |
2015年 | 200篇 |
2014年 | 216篇 |
2013年 | 258篇 |
2012年 | 263篇 |
2011年 | 256篇 |
2010年 | 126篇 |
2009年 | 118篇 |
2008年 | 164篇 |
2007年 | 157篇 |
2006年 | 139篇 |
2005年 | 117篇 |
2004年 | 111篇 |
2003年 | 108篇 |
2002年 | 95篇 |
2001年 | 25篇 |
2000年 | 15篇 |
1999年 | 29篇 |
1998年 | 28篇 |
1997年 | 19篇 |
1996年 | 8篇 |
1995年 | 20篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 15篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1966年 | 5篇 |
排序方式: 共有3639条查询结果,搜索用时 15 毫秒
181.
Atfaoui Khadija Omar Bouhnik Abdessamad Ettouil Rachid Ijoub Imane Ouryemchi Hicham Harhar Mohammed Ouhssine 《Biology Bulletin》2022,49(4):260-270
Biology Bulletin - Over 18 strains of lactic acid bacteria “LAB” isolated from different traditionally fermented products mainly sourdough and fermented vegetables, have been... 相似文献
182.
Peramaiyan Rajendran Abdullah M Alzahrani Hamza N Hanieh Sekar Ashok Kumar Rebai Ben Ammar Thamaraiselavan Rengarajan Mohammed A Alhoot 《Journal of cellular physiology》2019,234(12):21485-21492
Senescence and autophagy play important roles in homeostasis. Cellular senescence and autophagy commonly cause several degenerative processes, including oxidative stress, DNA damage, telomere shortening, and oncogenic stress; hence, both events are known to be interrelated. Autophagy is well known for its disruptive effect on human diseases, and it is currently proposed to have a direct effect on triggering senescence and quiescence. However, it is yet to be proven whether autophagy has a positive or negative impact on senescence. It is known that elevated levels of autophagy induce cell death, whereas inadequate autophagy can trigger cellular senescence. Both have important roles in human diseases such as aging, renal degeneration, neurodegenerative disorders, and cancer. Therefore, this review aims to highlight the relevance of senescence and autophagy in selected human ailments through a summary of recent findings on the connection and effects of autophagy and senescence in these diseases. 相似文献
183.
Nashwa Fathy Gamal El-Tahawy Samah Mohammed Mahmoud Abozaid 《Journal of cellular physiology》2019,234(9):15487-15495
The adrenal gland is an important endocrine gland in the body that secrets the adrenal hormones. One of the important clinical issues is the hepatic ischemia–reperfusion (IR) injury. Liver IR injury results in many distant organs dysfunctions such as lung, kidney, intestine, pancreas, and myocardium. The aim of the present study was to investigate the possible remote effects of hepatic IR on the structure of the adrenal cortex. Twenty healthy males, Sprague–Dawley albino rats aged 6–8 weeks were randomly divided into two groups (10 rats each): the sham control group (SC-group) and the ischemia–reperfusion group (IR-group). Sera were estimated for the following: aspartate transaminase (AST), alanine transaminase (ALT), lactic dehydrogenase (LDH), and corticosterone levels. Also oxidative markers such as malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α), and the antioxidative enzyme, catalase were measured. Adrenal glands were processed for light and transmission electron microscopic study. The results showed a significant increase in serum liver enzymes (AST, ALT, and LDH), corticosterone, MDA, and TNF-α levels and a significant decrease in serum levels of catalase in IR-group compared with SC-group. Adrenal cortical tissue of IR-group showed the loss of normal appearance. Some cells of zona glomerulosa and most of the zona fasciculata cells appeared swollen and degenerated with highly vacuolated cytoplasm. Other cells were shrunken with deeply acidophilic cytoplasm and pyknotic nuclei. Degenerated mitochondria with disrupted cristae, lipid droplets were confluent and dilated smooth endoplasmic reticulum were seen. Few zona reticularis cells had the dark nucleus and cytoplasmic vacuolations. In the different zones, blood capillaries were markedly congested and some inflammatory cells infiltrations were observed. Liver IR affected the structure of the adrenal cortex. 相似文献
184.
Chromosoma - The high-order structure of metaphase chromosomes remains still under investigation, especially the 30-nm structure that is still controversial. Advanced 3D imaging has provided useful... 相似文献
185.
Akash Tariq Kaiwen Pan Olusanya A Olatunji Corina Graciano Zilong Li Ningning Li Dagang Song Feng Sun Xiaogang Wu Mohammed A. Dakhil Xiaoming Sun Lin Zhang 《Physiologia plantarum》2019,166(4):894-908
Eucalyptus grandis is the most widely planted tree species worldwide and can face severe drought during the initial months after planting because the root system is developing. A complete randomized design was used to study the effects of two water regimes (well‐watered and water‐stressed) and phosphorus (P) applications (with and without P) on the morphological and physio‐biochemical responses of E. grandis. Drought had negative effects on the growth and metabolism of E. grandis, as indicated by changes in morphological traits, decreased net photosynthetic rates (Pn), pigment concentrations, leaf relative water contents (LRWCs), nitrogenous compounds, over‐production of reactive oxygen species (ROS) and higher lipid peroxidation. However, E. grandis showed effective drought tolerance strategies, such as reduced leaf area and transpiration rate (E), higher accumulation of soluble sugars and proline and a strong antioxidative enzyme system. P fertilization had positive effects on well‐watered seedlings due to improved growth and photosynthesis, which indicated the high P requirements during the initial E. grandis growth stage. In drought‐stressed seedlings, P application had no effects on the morphological traits, but it significantly improved the LRWC, Pn, quantum efficiency of photosystem II (Fv/Fm), chlorophyll pigments, nitrogenous compounds and reduced lipid peroxidation. P fertilization improved E. grandis seedling growth under well‐watered conditions but also ameliorated some leaf physiological traits under drought conditions. The effects of P fertilization are mainly due to the enhancement of plant N nutrition. Therefore, P can be used as a fertilizer to improve growth and production in the face of future climate change. 相似文献
186.
187.
Alex A. Pollen Aparna Bhaduri Madeline G. Andrews Tomasz J. Nowakowski Olivia S. Meyerson Mohammed A. Mostajo-Radji Elizabeth Di Lullo Beatriz Alvarado Melanie Bedolli Max L. Dougherty Ian T. Fiddes Zev N. Kronenberg Joe Shuga Anne A. Leyrat Jay A. West Marina Bershteyn Craig B. Lowe Bryan J. Pavlovic Arnold R. Kriegstein 《Cell》2019,176(4):743-756.e17
188.
Senna andhrica P.V. Ramana, J. Swamy and M. Ahmedullah, a new species from Andhra Pradesh, India, is described. The species is remarkable in having unifoliolate, oblong or ovate leaves, 2–3 carpellate gynoecium and reniform seeds. It is the second described species with unifoliolate leaves in the Cassiinae. In most other morphological characters, it is closely allied to Senna occidentalis (L.) Link. 相似文献
189.
Biological Trace Element Research - Instrumental neutron activation analysis (INAA) has been used to determine the concentration of some toxic chemical elements in a variety of aromatic plants... 相似文献
190.
Mohammed Arshad Hossain Khaled Al-Abdul-Elah Salim El-Dakour 《Zeitschrift fur angewandte Ichthyologie》2019,35(6):1197-1208
A 6‐month long study was conducted to improve the nutritional quality of the cultured sobaity bream, Sparidentex hasta by feeding them finisher feeds containing high docosahexaenoic acid (DHA) at the last two months of the grow‐out stage so that the muscle DHA level be increased at par to the wild. A grow‐out feed used from the beginning until the end of the trial was considered as the control (Diet 1). Experimental diets 2 and 3 were formulated to contain 9.0% DHA (e.g. 1.68 g DHA/100 g feed) and 10.5% DHA (2.20 g DHA/100 g feed), by incorporating high DHA tuna oil into a sea bream grow‐out diet. For comparison, a commercial finisher feed (Diet 4) from Skretting, Italy was also used. The results of this study demonstrated that fish fed DHA enriched finisher diets resulted in significantly (p < .05) better growth, feed utilization and higher muscle eicosapentaenoic acid (EPA) and DHA content compared to those fed grow‐out diet. The muscle DHA and EPA of fish fed finisher diets were also higher than those of the whole year average DHA and EPA content of wild sobaity. An organoleptic evaluation showed no significant (p > .05) differences between sensory attributes of muscle from cultured and wild sea bream. The results of the study demonstrated that feeding finisher feed enriched with DHA at the later part of the grow‐out operation, the n‐3 PUFA levels of cultured sobaity can cost‐effectively be increased at par to the wild. 相似文献