全文获取类型
收费全文 | 3495篇 |
免费 | 179篇 |
国内免费 | 7篇 |
出版年
2024年 | 8篇 |
2023年 | 34篇 |
2022年 | 144篇 |
2021年 | 215篇 |
2020年 | 91篇 |
2019年 | 111篇 |
2018年 | 138篇 |
2017年 | 90篇 |
2016年 | 159篇 |
2015年 | 200篇 |
2014年 | 216篇 |
2013年 | 259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3681条查询结果,搜索用时 15 毫秒
981.
Sherin Bakhashab Asma A Batarfi Najlaa Filimban Osama S Bajouh Ashraf Dallol Mohammed H Alqahtani 《Bioinformation》2021,17(11):904
Polycystic ovary syndrome (PCOS) is characterised by infertility, obesity, insulin resistance and clinical and/or biochemical signs of hyperandrogenism. Obesity is known to be correlated with PCOS causing ovulatory dysfunction and hormone imbalances. Moreover, fat mass and the obesity gene (FTO) were linked with obesity and PCOS. Therefore, it is of interest to determine the genotype and allele frequency for three FTO variants - rs17817449 (G/T), rs1421085 (C/T) and rs8050136 (A/C) -in western Saudi population. 95 PCOS patients and 94 controls were recruited for this study. The genetic variants were assayed using real-time polymerase chain reaction using TaqMan genotyping assays. The chi-squared test was applied to investigate the difference between single nucleotide polymorphisms on PCOS and control subjects, and binary logistic regression was used to determine the association of FTO variants with PCOS symptoms. Variants rs17817449 and rs1421085 were significantly linked with PCOS susceptibility in the study population. Rs17817449 and rs8050136 were significantly associated with hair loss in the PCOS group. Furthermore, rs1421085 and rs8050136 were associated with a high body mass index (BMI>30 kg/m2). Risk alleles in our population associated with hair loss and elevated BMI in women with PCOS were homozygous C for rs8050136. This data will help in defining the genetic predisposition of PCOS among women in western Saudi Arabia. 相似文献
982.
Hazem Elkady Alaa Elwan Hesham A. El-Mahdy Ahmed S. Doghish Ahmed Ismail Mohammed S. Taghour Eslam B. Elkaeed Ibrahim H. Eissa Mohammed A. Dahab Hazem A. Mahdy Mohamed M. Khalifa 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):397
A new series of benzoxazole derivatives were designed and synthesised to have the main essential pharmacophoric features of VEGFR-2 inhibitors. Cytotoxic activities were evaluated for all derivatives against two human cancer cell lines, MCF-7 and HepG2. Also, the effect of the most cytotoxic derivatives on VEGFR-2 protein concentration was assessed by ELISA. Compounds 14o, 14l, and 14b showed the highest activities with VEGFR-2 protein concentrations of 586.3, 636.2, and 705.7 pg/ml, respectively. Additionally, the anti-angiogenic property of compound 14b against human umbilical vascular endothelial cell (HUVEC) was performed using a wound healing migration assay. Compound 14b reduced proliferation and migratory potential of HUVEC cells. Furthermore, compound 14b was subjected to further biological investigations including cell cycle and apoptosis analyses. Compound 14b arrested the HepG2 cell growth at the Pre-G1 phase and induced apoptosis by 16.52%, compared to 0.67% in the control (HepG2) cells. The effect of apoptosis was buttressed by a 4.8-fold increase in caspase-3 level compared to the control cells. Besides, different in silico docking studies were also performed to get better insights into the possible binding mode of the target compounds with VEGFR-2 active sites. 相似文献
983.
Noor
A. Mohammed Israa
J. Hakeem Nikolas Hodges Francesco Michelangeli 《Bioscience reports》2022,42(1)
Doxorubicin (DOX) is a potent anticancer drug, which can have unwanted side-effects such as cardiac and kidney toxicity. A detailed investigation was undertaken of the acute cytotoxic mechanisms of DOX on kidney cells, using Cos-7 cells as kidney cell model. Cos-7 cells were exposed to DOX for a period of 24 h over a range of concentrations, and the LC50 was determined to be 7 µM. Further investigations showed that cell death was mainly via apoptosis involving Ca2+ and caspase 9, in addition to autophagy. Regucalcin (RGN), a cytoprotective protein found mainly in liver and kidney tissues, was overexpressed in Cos-7 cells and shown to protect against DOX-induced cell death. Subcellular localization studies in Cos-7 cells showed RGN to be strongly correlated with the nucleus. However, upon treatment with DOX for 4 h, which induced membrane blebbing in some cells, the localization appeared to be correlated more with the mitochondria in these cells. It is yet to be determined whether this translocation is part of the cytoprotective mechanism or a consequence of chemically induced cell stress. 相似文献
984.
Wagdy M. Eldehna Mohammed S. Taghour Tarfah Al-Warhi Alessio Nocentini Mostafa M. Elbadawi Hazem A. Mahdy Mohamed A. Abdelrahman Ohoud J. Alotaibi Nada Aljaeed Diaaeldin M. Elimam Kamyar Afarinkia Hatem A. Abdel-Aziz Claudiu T. Supuran 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):531
Different 2,4-thiazolidinedione-tethered coumarins 5a–b, 10a–n and 11a–d were synthesised and evaluated for their inhibitory action against the cancer-associated hCAs IX and XII, as well as the physiologically dominant hCAs I and II to explore their selectivity. Un-substituted phenyl-bearing coumarins 10a, 10 h, and 2-thienyl/furyl-bearing coumarins 11a–c exhibited the best hCA IX (KIs between 0.48 and 0.93 µM) and hCA XII (KIs between 0.44 and 1.1 µM) inhibitory actions. Interestingly, none of the coumarins had any inhibitory effect on the off-target hCA I and II isoforms. The sub-micromolar compounds from the biochemical assay, coumarins 10a, 10 h and 11a–c, were assessed in an in vitro antiproliferative assay, and then the most potent antiproliferative agent 11a was tested to explore its impact on the cell cycle phases and apoptosis in MCF-7 breast cancer cells to provide more insights into the anticancer activity of these compounds. 相似文献
985.
We studied photosynthetic acclimation of eastern hemlock [Tsuga canadensis (L.) Carr.] seedlings in the first month after sudden exposure of shade-grown seedlings to full sunlight. In a greenhouse
experiment, seedlings were grown under full sun or 80% shade, and after 7 months, a sample of the shaded trees was transferred
to full sun in the greenhouse. Photosynthetic responses of shaded, transferred, and sun trees were followed over the course
of 26 days to track short to medium-term acclimation responses. A partial acclimation of photosynthesis at high light occurred
in pre-existing (formed in the previous environment) and new foliage of transferred seedlings. This was associated with non-stomatal
limitations to photosynthesis. Pre-existing foliage of transferred plants had a prolonged reduction in the ratio of variable
to maximal fluorescence, and a limited capacity to adjust photochemical quenching or photosystem II quantum yield in the light
to increasing light intensity compared to sun foliage, and apparently had some difficulty sustaining non-photochemical quenching.
Seedling survival was only 58% among transferred seedlings, compared to 80% and 100% in the shade or sun groups, respectively.
Photosystem II quantum yield in the light, and photochemical and non-photochemical quenching were similar between newly formed
foliage of transferred and sun plants. These findings indicate that eastern hemlock depends strongly on the production of
new foliage for photosynthetic adjustments to high light, and that development of photosynthetic competence may be a gradual
process that occurs over successive foliar production cycles.
Received: 12 May 1998 / Accepted: 27 July 1998 相似文献
986.
Mohammed Mebarek Bia Seongjun Choe Barakaeli Abdieli Ndosi Hansol Park Yeseul Kang Chatanun Eamudomkarn Tilak Chandra Nath Sunmin Kim Hyeong-Kyu Jeon Dongmin Lee Keeseon S. Eom 《The Korean journal of parasitology》2021,59(5):457
Cystic echinococcosis is a zoonotic parasitic disease caused by Echinococcus species. Tanzania is one of the endemic countries with cystic echinococcosis. This study focussed on identifying genotypes of Echinococcus spp. in Tanzania. We collected 7 cysts from cattle in Mwanza municipal (n=4) and Loliondo district (n=3). The cysts from Mwanza were all E. ortleppi and fertile. In contrast, the cysts from Loliondo were all E. granulosus sensu stricto and sterile. Two from the 4 cysts were a new haplotype of E. ortleppi (G5). These results can improve the preventive and control programs for humans and livestock in Tanzania. To our knowledge, this study is considered the first to identify the genotype and haplotype of Echinococcus spp. in Tanzania. 相似文献
987.
Azza I. Othman Mohammed A. El Missiry 《Journal of biochemical and molecular toxicology》1998,12(6):345-349
Male albino rats were intramuscularly administered a single dose of lead acetate (100 μmol/kg b.wt). Another group of rats were injected with sodium selenite (10 μmol/kg b.wt) before lead intoxication. After 3 and 24 hours, lead treatment resulted in significant increases in acid and alkaline phosphatases, GOT and GPT, total proteins, and cholesterol in serum. The total triglycerides in serum was decreased after 24 hours of intoxication. Lead treatment also produced significant elevation of lipid peroxidation in liver and kidney. The antioxidant capacity of hepatic and renal cells in terms of the activities of superoxide dismutase, glutathione reductase, and glutathione content was diminished. It appears from these results that lead may exert its toxic effect via peroxidative damage to renal and hepatic cell membranes after 24 hours. Selenium administration prior to lead injection produced pronounced prophylactic action against lead effects, and it is observed that selenium enhances the endogenous antioxidant capacity of the cells by increasing the activities of the superoxide dismutase and glutathione reductase and the glutathione content. As a result, the lipid peroxidation was decreased in both liver and kidney. © 1998 John Wiley & Sons, Inc. J Biochem Mol Toxicol 12: 345–349, 1998 相似文献
988.
Ahmed M. Ahmed Medhat M. Haikal Ahmed A. Mohammed Mohammed A. Zidan 《International Review of Hydrobiology》1986,71(1):127-138
Monthly variations of some physical and chemical characteristics of Nile waters at Assiut (375 km south from Cairo, Egypt) during the period from September 1980 to September 1982 were followed and discussed. As expected, the maximum temperature was recorded in summer and the minimum in winter. The pH values of Nile waters were recorded to be in the vicinity of 8.0. The highest oxygen concentrations were recorded in the summer months, mainly due to the relatively high photosynthetic activity. The total soluble salts and the total alkalinity exhibited almost identical trends. Nitrate, phosphate, silicate and chloride concentrations showed no major regular trends. The cation abundances by weight were as follows: Ca2+ > Na+ > Mg2+ > K+. 相似文献
989.
Khalid Farouq Al-rawi Hameed Hussein Ali Manaf Abdulrahman Guma Bilal Jasir Mohammed Aldahham Shakir Faris Tuleab Alaaraji Osamah Al-ani Aus Tariq Ali 《Reports of Biochemistry & Molecular Biology》2022,10(4):664
Background:Chronic kidney disease (CKD), is a major public health challenge worldwide. It is more prevalent in developed countries compared with the rest of the world, due to the higher rates of life expectancy and unhealthy lifestyle related factors. This aim of the current study is to evaluate the relationship between interleukins IL-2 and IL-17 concentrations and kidney function markers in men with CKD.Methods:Forty-five men with CKD and seventy controls were enrolled in the current study to assess the relationship between interleukin-2 (IL-2), interleukin-17 (IL-17), and CKD parameters. Fasting blood samples were collected from patients with CKD and their controls at same time. Serum IL-2, and IL-17 were measured in patients with CKD and their controls, and then the relationship between these interleukins and serum creatinine, serum urea, serum uric acid and urine albumin were evaluated.Results:A significant relationship was detected between IL-2 (p< 0.001), IL-17 (p< 0.001) levels and serum creatinine concentrations. The significant increase of IL-2 and IL-17 levels were also paralleled with a significant increase in serum urea (p< 0.001), and urine albumin (p< 0.001) concentrations respectively.Conclusion:IL-2 and IL-17 may play a critical role in the pathophysiology of CKD. The significant increase of IL-2 and IL-17 is associated with significantly high concentrations of creatinine, serum urea and urine albumin suggesting that these interleukins may be used as targets for future biomarkers and molecular therapy. However, due to limited sample size of the current study, larger prospective cohorts are needed to confirm these observations.Key Words: Chronic kidney disease, Interleukins, Serum creatinine, Serum urea, Urine albumin 相似文献
990.
Hanan Sharaf El-Deen Mohammed Manal Mohamed Kamal Hala Mostafa ElBadre Amal Hosni Azza Abo Elfadl Mohamed Ahmed Mostafa Reham Ibrahim El-Mahdy 《Reports of Biochemistry & Molecular Biology》2022,10(4):537
Background:Oxidized low-density lipoprotein (ox-LDL) has an important role in the genesis of coronary atherosclerosis. Lectin-like ox-LDL receptor 1 (OLR1) contributes to the uptake and internalization of ox-LDL. Genetic polymorphisms have been associated with coronary artery disease (CAD). Here we explore the association of plasma levels of ox-LDL and 3′ UTR OLR1 (rs1050286) SNP with CAD risk and in-hospital adverse outcomes.Methods:A case-control study enrolled 192 patients with ST-segment elevation myocardial infarction (STEMI), 100 patients with unstable angina, and 100 healthy controls. Baseline, clinical characteristics, and risk scores of the patients were determined. Plasma ox-LDL and other biochemical variables were measured. All subjects are genotyped for OLR1 (rs1050286) by RT-PCR with TaqMan SNP genotyping assay.Results:Plasma ox-LDL was higher with enhanced sensitivity and specificity in identifying patients with STEMI and was found as a significant independent risk factor for CAD in those two groups. Levels of ox-LDL were increased with increasing poor prognostic factors in STEMI patients that are associated with an increased incidence of some adverse events and in-hospital mortality. Elevated STEMI risk was associated with T allele of OLR1 (rs1050286) (odds ratio of 4.9, 95% CI: 2.6-9.4, p< 0.001). STEMI patients who have T allele exhibited higher risk scores, coronary multivessel narrowing, and elevated incidence of in-hospital major adverse clinical events.Conclusion:These results suggest that plasma ox-LDL, as well as T allele of ORL-1 (rs1050286), is associated with the increased risk for developing STEMI and the associated adverse clinical outcomes.Key Words: Coronary artery disease, genotyping, OLR1, outcomes, Oxidized low-density lipoprotein 相似文献