全文获取类型
收费全文 | 721篇 |
免费 | 43篇 |
国内免费 | 2篇 |
出版年
2023年 | 10篇 |
2022年 | 22篇 |
2021年 | 20篇 |
2020年 | 16篇 |
2019年 | 21篇 |
2018年 | 24篇 |
2017年 | 19篇 |
2016年 | 26篇 |
2015年 | 34篇 |
2014年 | 42篇 |
2013年 | 49篇 |
2012年 | 38篇 |
2011年 | 36篇 |
2010年 | 32篇 |
2009年 | 27篇 |
2008年 | 22篇 |
2007年 | 27篇 |
2006年 | 26篇 |
2005年 | 36篇 |
2004年 | 22篇 |
2003年 | 22篇 |
2002年 | 21篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 14篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 17篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1974年 | 6篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1965年 | 4篇 |
1964年 | 5篇 |
排序方式: 共有766条查询结果,搜索用时 15 毫秒
141.
Osama M. Abo‐Salem Gamaleldin I. Harisa Tarek M. Ali El‐Sayed M. El‐Sayed Fatma M. Abou‐Elnour 《Journal of biochemical and molecular toxicology》2014,28(6):263-270
Heart failure (HF) is one of diabetic complications. This work was designed to investigate the possible modulatory effect of curcumin against streptozotocin‐induced diabetes and consequently HF in rats. Rats were divided into control, vehicle‐treated, curcumin‐treated, diabetic‐untreated, diabetic curcumin–treated, and diabetic glibenclamide–treated groups. Animal treatment was started 5 days after induction of diabetes and extended for 6 weeks. Diabetic rats showed significant increase in serum glucose, triglycerides, total cholesterol, low‐density lipoprotein‐cholesterol, very low density lipoprotein‐cholesterol, nitric oxide, lactate dehydrogenase, cardiac malondialdehyde, plasma levels of interleukin‐6, and tumor necrosis factor‐alpha, and also showed marked decrease in serum high‐density lipoprotein‐cholesterol, cardiac reduced glutathione, and cardiac antioxidant enzymes (catalase, superoxide dismutase, and glutathione‐S‐transferase). However, curcumin or glibenclamide treatment significantly mitigated such changes. In conclusion, curcumin has a beneficial therapeutic effect in diabetes‐induced HF, an effect that might be attributable to its antioxidant and suppressive activity on cytokines. 相似文献
142.
Vasili Stegajev Vesa-Petteri Kouri Abdelhakim Salem Stanislav Rozov Holger Stark Dan C. E. Nordström Yrjö T. Konttinen 《Apoptosis : an international journal on programmed cell death》2014,19(12):1702-1711
Apoptosis is involved in the pathogenesis of Sjögren’s syndrome (SS), an autoimmune disease affecting exocrine glands. Our recent studies revealed diminished histamine H4 receptor (H4R) expression and impaired histamine transport in the salivary gland epithelial cells in SS. The aim was now to test if nanomolar histamine and high-affinity H4R signaling affect apoptosis of human salivary gland epithelial cell. Simian virus 40-immortalized acinar NS-SV-AC cells were cultured in serum-free keratinocyte medium ± histamine H4R agonist HST-10. Expression and internalization of H4R were studied by immunofluorescence staining ± clathrin inhibitor methyl-β-cyclodextrin (MβCD). Apoptosis induced using tumor necrosis factor-α with nuclear factor-κB inhibitor IMD-0354 was studied using phase contrast microscopy, Western blot, flow cytometry and polymerase chain reaction (qRT-PCR). HST-10-stimulated H4R internalization was inhibited by MβCD. Western blotting revealed diminished phosphorylated c-Jun N-terminal kinase JNK, but unchanged levels of phosphorylated extracellular signal regulated kinase pERK1/2 in H4R-stimulated samples compared to controls. qRT-PCR showed up-regulated expression of anti-apoptotic B cell lymphoma-extra large/Bcl-xL mRNAs and proteins, whereas pro-apoptotic Bcl-2-associated X protein/BAX remained unchanged in H4R-stimulated samples. H4R stimulation diminished cleavage of PARP and flow cytometry showed significant dose-dependent inhibitory effect of H4R stimulation on apoptosis. As far as we know this is the first study showing inhibitory effect of H4R activation on apoptosis of human salivary gland cells. Diminished H4R-mediated activation may contribute to loss of immune tolerance in autoimmune diseases and in SS in particular. 相似文献
143.
144.
A comparison of dorsal and heel plate foot tracking methods on lower extremity dynamics 总被引:1,自引:0,他引:1
The primary method to model ankle motion during inverse dynamic calculations of the lower limb is through the use of skin-mounted markers, with the foot modeled as a rigid segment. Motion of the foot is often tracked via the use of a marker cluster triad on either the dorsum, or heel, of the foot/shoe. The purpose of this investigation was to evaluate differences in calculated lower extremity dynamics during the stance phase of gait between these two tracking techniques. In an analysis of 7 subjects, it was found that sagittal ankle angles and sagittal ankle, hip and knee moments were strongly correlated between the two conditions, however, there was a significant difference in peak ankle plantar flexion and dorsiflexion angles. Frontal ankle angles were only moderately correlated and there was a significant difference in peak ankle eversion and inversion, resulting in moderate correlations in frontal plane moments and a significant difference in peak hip adductor moments. We demonstrate that the technique used to track the foot is an important consideration in interpreting lower extremity dynamics for clinical and research purposes. 相似文献
145.
146.
Haytham O. Tawfik Moataz A. Shaldam Alessio Nocentini Rofaida Salem Hadia Almahli Sara T. Al-Rashood Claudiu T. Supuran Wagdy M. Eldehna 《Journal of enzyme inhibition and medicinal chemistry》2022,37(1):1043
Carbonic anhydrases (CAs) are one of the promising targets for the development of anticancer agents. CA isoforms are implicated in various physiological processes and are expressed in both normal and cancerous cells. Thus, non-isoform selective inhibitors are associated with several side effects. Consequently, designing selective inhibitors towards cancer-related hCA IX/XII rather than the ubiquitous cytosolic isozymes hCA I and II is the main research objective in the field. Herein, a new series of 3-(6-methylpyridin-2-yl)coumarin derivatives 3 and 5a–o was designed and synthesised. The CA inhibition activities for the synthesised coumarins were analysed on isoforms hCA I, II, IX, and XII. Interestingly, both cancer-linked isoforms hCA IX/XII were inhibited by the prepared coumarins with inhibition constants ranging from sub- to low-micromolar range, whereas hCA I and II isoforms haven’t been inhibited up to 100 µM. Furthermore, the target coumarins were assessed for their antitumor activity on NCI-59 human cancer types. 相似文献
147.
Ibrahim mahmoud Mokhles Hassan Salama Mostafa Aboelenin Mohamed Mohamed Soliman Hossam Fouad Attia Khaled. A. Metwally Heba M. Salem Amira M. El-Tahan Mohamed T. El-Saadony Rafat Khalaphallah 《Saudi Journal of Biological Sciences》2022,29(4):2969
This work aimed to co-digest various wastes to assess the best combination of all mixing ratio, also at choosing the best ratio between untreated primary sludge (UPS) singly from two sources, (South valley University (SUPS) and Abu tesht wastewater station (AUPS) and raw chicken manure (RCM) and comparing the results in either case. The co-digestions of untreated primary sludge from Abu tesht wastewater treatment stations with different levels of raw chicken manure (0:100, 10:90, 30:70, 50:50, 90:10, and 100:0) to obtain the best mixtures. Also, co-digestion of untreated primary sludge from south valley university with different levels of raw chicken manure at the same ratios, to obtain the best mixtures. Batch digestion tests were applied in 2.5 L digester with a working volume of 2.0 L. The samples in triplicates were separately loaded into the digesters locally fabricated and kept for 20 days as a retention period and diluted with the same amount of water. Mesophilic under 35 °C was adopted for untreated primary sludge as well as mixtures with raw chicken manure based on total solids (TS) and volatile solid (VS) proportions. The average biogas yields from AUPS/RCM mixture obtained ranged from 8570 to 5600 ml, by the following descending order, 10: 90 > 90:10 and so on >100:0, and the average biogas yields from SUPS/RCM obtained ranged from 6330 to 5635 ml, in the order of 90: 10 > 10:90 and so on >100:0. The results showed highest biogas yield from AUPS/RCM and SUPS/RCM mixtures with mixing ratio of 10:90 and 90:10, respectively, however, the lowest biogas production detected in separate digestion of AUPS and SUPS. The results indicated that co-digestion between the sludge and raw chicken manure could increase total biogas production volume, enhance sludge treatment process, and produce eco-friendly sludge because of co-digestion process than separate processing of each feedstock. 相似文献
148.
Effect of vegetation on density thresholds of adult desert locust gregarization from survey data in Mauritania 总被引:1,自引:0,他引:1
Sory Cisse Saïd Ghaout Ahmed Mazih Mohamed Abdallahi Ould Babah Ebbe Ahmed Salem Benahi Cyril Piou 《Entomologia Experimentalis et Applicata》2013,149(2):159-165
In the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), the threshold density inducing the gregarization phenomenon has never been determined under natural conditions. The influence of environmental factors on this phenomenon has been studied mostly in controlled environments. Based on data collected during several years by the survey teams of the National Center for Locust Control in Mauritania, we analyzed the influence of locust density, vegetation cover, and vegetation status on the probability of observing gregarious locusts. We assumed that a probability to observe gregarious locusts of 0.5 corresponded to the density threshold of gregarization. The results showed in detail the change in the threshold of gregarization according to the cover and status of the vegetation. Low cover and dry vegetation led to a low density threshold of gregarization probably due to high probability of individuals to touch each other. Dense and green vegetation favored a high threshold of gregarization probably due to a dispersion of the individuals and a low probability of individual encounters. These findings should help the management of locusts and decision making during control operations. 相似文献
149.
Giron-Michel J Azzi S Khawam K Mortier E Caignard A Devocelle A Ferrini S Croce M François H Lecru L Charpentier B Chouaib S Azzarone B Eid P 《PloS one》2012,7(2):e31624
The ability of Interleukin-15 (IL-15) to activate many immune antitumor mechanisms renders the cytokine a good candidate for the therapy of solid tumors, particularly renal cell carcinoma. Although IL-15 is being currently used in clinical trials, the function of the cytokine on kidney's components has not been extensively studied; we thus investigated the role of IL-15 on normal and tumor renal epithelial cells. Herein, we analyzed the expression and the biological functions of IL-15 in normal renal proximal tubuli (RPTEC) and in their neoplastic counterparts, the renal clear cell carcinomas (RCC). This study shows that RPTEC express a functional heterotrimeric IL-15Rαβγc complex whose stimulation with physiologic concentrations of rhIL-15 is sufficient to inhibit epithelial mesenchymal transition (EMT) commitment preserving E-cadherin expression. Indeed, IL-15 is not only a survival factor for epithelial cells, but it can also preserve the renal epithelial phenotype through the γc-signaling pathway, demonstrating that the cytokine possess a wide range of action in epithelial homeostasis. In contrast, in RCC in vitro and in vivo studies reveal a defect in the expression of γc-receptor and JAK3 associated kinase, which strongly impacts IL-15 signaling. Indeed, in the absence of the γc/JAK3 couple we demonstrate the assembly of an unprecedented functional high affinity IL-15Rαβ heterodimer, that in response to physiologic concentrations of IL-15, triggers an unbalanced signal causing the down-regulation of the tumor suppressor gene E-cadherin, favoring RCC EMT process. Remarkably, the rescue of IL-15/γc-dependent signaling (STAT5), by co-transfecting γc and JAK3 in RCC, inhibits EMT reversion. In conclusion, these data highlight the central role of IL-15 and γc-receptor signaling in renal homeostasis through the control of E-cadherin expression and preservation of epithelial phenotype both in RPTEC (up-regulation) and RCC (down-regulation). 相似文献
150.
Physiological compartmental analysis of alpha-linolenic acid metabolism in adult humans 总被引:10,自引:0,他引:10
A physiological compartmental model of alpha-linolenic acid metabolism was derived from the plasma concentration-time curves for d5-18:3n-3, d5-20:5n-3, d5-22:5n-3, and d5-22:6n-3 in eight healthy subjects. Subjects received a 1-g oral dose of an isotope tracer of alpha-linolenate (d5-18:3n-3 ethyl ester) while subsisting on a rigorously controlled beef-based diet. By utilizing the Windows Simulation and Analysis Modeling program, kinetic parameters were determined for each subject. Half-lives and mean transit times of the n-3 fatty acids in the plasma were also determined. The model predicted plasma values for the n-3 fatty acids in good accordance with the measured steady state concentrations and also predicted dietary linolenic acid intake for each subject in accordance with values determined by lipid analysis of the diet. Only about 0.2% of the plasma 18:3n-3 was destined for synthesis of 20:5n-3, approximately 63% of the plasma 20:5n-3 was accessible for production of 22:5n-3, and 37% of 22:5n-3 was available for synthesis of 22:6n-3. The inefficiency of the conversion of 18:3n-3 to 20:5n-3 indicates that the biosynthesis of long-chain n-3 PUFA from alpha-linolenic acid is limited in healthy individuals. In contrast, the much greater rate of transfer of mass from the plasma 20:5n-3 compartment to 22:5n-3 suggests that dietary eicosapentaenoic acid may be well utilized in the biosynthesis of 22:6n-3 in humans. 相似文献