全文获取类型
收费全文 | 1000篇 |
免费 | 54篇 |
国内免费 | 1篇 |
专业分类
1055篇 |
出版年
2024年 | 4篇 |
2023年 | 29篇 |
2022年 | 46篇 |
2021年 | 72篇 |
2020年 | 85篇 |
2019年 | 115篇 |
2018年 | 73篇 |
2017年 | 43篇 |
2016年 | 66篇 |
2015年 | 29篇 |
2014年 | 66篇 |
2013年 | 72篇 |
2012年 | 60篇 |
2011年 | 65篇 |
2010年 | 26篇 |
2009年 | 30篇 |
2008年 | 30篇 |
2007年 | 39篇 |
2006年 | 23篇 |
2005年 | 22篇 |
2004年 | 20篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1995年 | 4篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1949年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有1055条查询结果,搜索用时 9 毫秒
991.
992.
993.
Moslem Sharifinia Zahra Afshari Bahmanbeigloo Walker O. Smith Chee Kong Yap Mehrzad Keshavarzifard 《Global Change Biology》2019,25(12):4022-4033
Due to extremely high rates of evaporation and low precipitation in the Persian Gulf, discharges from desalination plants (DPs) can lead to ecological stresses by increasing water temperatures, salinities, and heavy metal concentrations, as well as decreasing dissolved oxygen levels. We discuss the potential ecological impacts of DPs on marine organisms and propose mitigating measures to reduce the problems induced by DPs discharges. The daily capacity of DPs in the Persian Gulf exceeds 11 million m3 per day, which is approximately half of global daily freshwater production; multistage flash distillation (MSF) is the dominant desalination process. Results from field and laboratory studies indicate that there are potentially serious and chronic threats to marine communities following exposure to DP discharges, especially within the zoobenthos, echinodermata, seagrasses, and coral reefs. DP discharges can lead to decreases in sensitive species, plankton abundance, hard substrate epifauna, and growth rates of seagrasses. However, the broad applicability of any one of these impacts is currently hard to scale because of the limited number of studies that have been conducted to assess the ecological impacts of DP discharge on Persian Gulf organisms. Even so, available data suggest that appropriately sited, designed, and operated DPs combined with current developments in impingement and entrainment reduction technology can mitigate many of the negative environmental impacts of DPs. 相似文献
994.
Reza Mohammadinejad Zahra Ahmadi Shima Tavakol Milad Ashrafizadeh 《Journal of cellular physiology》2019,234(9):14914-14926
Today, pharmacognosy is considered a valuable science in the prevention and treatment of diseases. Among herbals, Berberine is an isoquinoline alkaloid found in the Berberis species. Surprisingly, it shows antimicrobial, antiviral, antidiarrheal, antipyretic, and anti-inflammatory potential. Furthermore, it diminishes drug resistance in cancer therapy and enhances tumor suppression in part through autophagy and cell cycle arrest mechanisms. In the present review, we discuss the effect of berberine on diverse cellular pathways and describe how berberine acts as an autophagy modulator to adjust physiologic and pathologic conditions and diminishes drug resistance in cancer therapy. 相似文献
995.
996.
Photophysical phenomena associated with carbon nanoparticles in combination with biocompatibility and readily functionalizable properties have attracted significant interest for sensing and imaging applications. A potassium ion optode based on the fluorescence quenching of carbon quantum dots (CQDs) was constructed. The CQDs were synthesized using a microwave method, citric acid and 2,2′‐(ethylene‐dioxy)bis(ethylamine). A quantum yield of 7.1% was calculated for the synthesized CQDs. A linear dynamic range of about one‐order of magnitude with a correlation coefficient of 0.99 was obtained. The optode was applied on real samples and a 0.60–1.60% error range was obtained relative to the ion‐selective electrode. 相似文献
997.
Zahra Payandeh Effat Noori Bahman Khalesi Maysam Mard-Soltani Jalal Abdolalizadeh Saeed Khalili 《Biotechnology letters》2018,40(11-12):1459-1466
CD37 is a member of tetra-spanning superfamily (characterized by their four transmembrane domains). It is one of the specific proteins for normal and malignant mature B cells. Anti CD37 monoclonal antibodies are reported to improve the overall survival in CLL. These therapeutics will increase the efficacy and reduce the toxicity in patients with both newly diagnosed and relapsed and refractory disease. Recent clinical trials have shown promising outcomes for these agents, administered both as monotherapy and in combination with standard chemotherapeutics. Long-term follow-up of combination regimens has even raised the question of whether the patients with CLL could be treated with intensive chemo-immunotherapy. In the present study, CD37 is introduced as an appealing target to treat B cell malignancies. The anti-CD37 antibodies as one of the most successful therapeutics against CD37 are introduced and the clinical outcomes of their exploitation are explained. 相似文献
998.
999.
Kobra Tahmasebi Reza Amani Zahra Nazari Kambiz Ahmadi Sara Moazzen Seyed-Ali Mostafavi 《Biological trace element research》2017,178(2):180-188
Among various factors influencing mood disorders, the impact of micronutrient deficiencies has attracted a great attention. Zinc deficiency is considered to play a crucial role in the onset and progression of mood disorders in different stages of life. The main objective of this study was to assess the correlation between serum zinc levels and mood disorders in high school female students. This cross-sectional study was conducted on a random sample of 100 representative high school female students. The participants completed 24-h food recall questionnaires to assess the daily zinc intakes. Serum zinc status was assessed using flame atomic absorption spectrometry, and zinc deficiency was defined accordingly. Mood disorders were estimated by calculating the sum of two test scores including Beck’s depression inventory (BDI) and hospital anxiety depression scale (HADS) tests. General linear model (GLM) and Pearson’s regression test were applied to show the correlation of serum zinc levels and mood disorder scores and the correlation between zinc serum levels and BDI scores, respectively. Dietary zinc intake was higher in subjects with normal zinc concentrations than that of zinc-deficient group (p = 0.001). Serum zinc levels were inversely correlated with BDI and HADS scores (p < 0.05). Each 10 μg/dL increment in serum zinc levels led to 0.3 and 0.01 decrease in depression and anxiety scores, respectively (p < 0.05). Serum zinc levels were inversely correlated with mood disorders including depression and anxiety in adolescent female students. Increasing serum levels of zinc in female students could improve their mood disorders. 相似文献
1000.
Khodaiyan F Razavi SH Emam-Djomeh Z Mousavi SM Hejazi MA 《Journal of microbiology and biotechnology》2007,17(2):195-201
This study investigated the effects of various culture parameters (carbon sources, temperature, initial pH of culture, NaCl concentration, and light) on the growth and canthaxanthin production by Dietzia natronolimnaea HS-1. The results showed that the most effective carbon source for growth and canthaxantin production was glucose, and the best pH and temperature were 7 and 31 degrees C, respectively. In addition, the biomass and canthaxanthin production increased in a medium without NaCl and in the presence of light. Under the optimized conditions, the maximum biomass, total carotenoid, and canthaxanthin production were 6.12 +/- 0.21 g/l, 4.51 +/- 0.20 mg/l, and 4.28 +/- 0.15 mg/l, respectively, in an Erlenmeyer flask system, yet increased to 7.25 g/l, 5.48 mg/l, and 5.29 mg/l, respectively, in a batch fermenter system. 相似文献