全文获取类型
收费全文 | 6193篇 |
免费 | 370篇 |
国内免费 | 1篇 |
出版年
2023年 | 57篇 |
2022年 | 82篇 |
2021年 | 166篇 |
2020年 | 117篇 |
2019年 | 143篇 |
2018年 | 194篇 |
2017年 | 149篇 |
2016年 | 244篇 |
2015年 | 337篇 |
2014年 | 381篇 |
2013年 | 425篇 |
2012年 | 528篇 |
2011年 | 537篇 |
2010年 | 325篇 |
2009年 | 239篇 |
2008年 | 335篇 |
2007年 | 361篇 |
2006年 | 353篇 |
2005年 | 264篇 |
2004年 | 259篇 |
2003年 | 224篇 |
2002年 | 213篇 |
2001年 | 54篇 |
2000年 | 38篇 |
1999年 | 37篇 |
1998年 | 53篇 |
1997年 | 43篇 |
1996年 | 45篇 |
1995年 | 32篇 |
1994年 | 29篇 |
1993年 | 24篇 |
1992年 | 32篇 |
1991年 | 19篇 |
1990年 | 18篇 |
1989年 | 22篇 |
1988年 | 19篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1984年 | 7篇 |
1983年 | 11篇 |
1982年 | 13篇 |
1981年 | 8篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1973年 | 8篇 |
排序方式: 共有6564条查询结果,搜索用时 31 毫秒
111.
Martini Claudia Sosa Fernando Nicolas Malvicini Ricardo Pacienza Natalia Yannarelli Gustavo del C. Vila María 《Journal of physiology and biochemistry》2021,77(4):601-611
Journal of Physiology and Biochemistry - Alendronate, a bisphosphonate used to prevent osteoporosis, stimulates osteogenesis but impairs adipogenesis. Different clinical trials suggest that the... 相似文献
112.
113.
Joo L. Pereira Patrícia Cavaco Ricardo C. da Silva Ivette Pacheco-Leyva Stefan Mereiter Ricardo Pinto Celso A. Reis Nuno R. dos Santos 《Translational oncology》2021,14(8)
P-selectin glycoprotein ligand-1 (PSGL-1) is a membrane-bound glycoprotein expressed in lymphoid and myeloid cells. It is a ligand of P-, E- and L-selectin and is involved in T cell trafficking and homing to lymphoid tissues, among other functions. PSGL-1 expression has been implicated in different lymphoid malignancies, so here we aimed to evaluate the involvement of PSGL-1 in T cell lymphomagenesis and dissemination. PSGL-1 was highly expressed at the surface of human and mouse T cell leukemia and lymphoma cell lines. To assess its impact on T cell malignancies, we stably expressed human PSGL-1 (hPSGL-1) in a mouse thymic lymphoma cell line, which expresses low levels of endogenous PSGL-1 at the cell surface. hPSGL-1-expressing lymphoma cells developed subcutaneous tumors in athymic nude mice recipients faster than control empty vector or parental cells. Moreover, the kidneys, lungs and liver of tumor-bearing mice were infiltrated by hPSGL-1-expressing malignant T cells. To evaluate the role of PSGL-1 in lymphoma cell dissemination, we injected intravenously control and hPSGL-1-expressing lymphoma cells in athymic mice. Strikingly, PSGL-1 expression facilitated disease infiltration of the kidneys, as determined by histological analysis and anti-CD3 immunohistochemistry. Together, these results indicate that PSGL-1 expression promotes T cell lymphoma development and dissemination to different organs. 相似文献
114.
Ricardo Calado Ainhoa O. Olaguer-Feliú Juan Ignacio González-Gordillo Henrique Queiroga 《Marine and Freshwater Behaviour and Physiology》2013,45(5):329-341
During the mass settlement events of brachyuran crabs, there is a significant chance of density-dependent injury in the megalopae (last larval stage) because cannibalism can occur by larger conspecifics. Laboratory observations revealed that the appendages that are more prone to injury are eyestalks, as well as first (P1) and fifth (P5) pereiopods. The ability of Carcinus maenas megalopae to autotomize these structures and the effect of such injuries in their feeding ability and metamorphosis were investigated. All tested specimens were able to autotomize one or both of their P1 and P5, but not their eyestalks. Megalopae missing a single P1, as well as one or both P5, were able to capture and ingest prey, as well as intact specimens. Megalopae with either P1 and P5 appendages or at least one damaged eyestalk failed to ingest sufficient food to reach the nutritional threshold required to successfully metamorphose. 相似文献
115.
We describe intergradations between the arthropod repichnial trace fossils Diplichnites gouldi (Gevers et al., 1971), Dendroidichnites Demathieu et al., 1992, and Monomorphichnus Crimes, 1970 with two distinct cubichnial traces, Gluckstadtella cooperi Savage, 1971 and Huilmuichnus santracruzensis new ichnogenus and ichnospecies. These compound ichnofossils are part of high ichnodiversity arthropod-dominated trace fossil associations from the Late Carboniferous Agua Escondida Formation of the San Rafael Basin (Argentina). The complex ichnotaxonomy of Diplichnites and the ichnospecies D. gouldi are discussed and some possible working solutions are proposed. The most likely producer of the compound trace fossils are the Pygocephalomorpha, a group of Late Paleozoic crustaceans that are recorded in nearby basins from Uruguay and Brazil. The compound trace fossils are used to infer a number of complex behaviors of pygocephalomorphs in a subaqueous setting, including caridoid (tail flip) or more primitive escape reactions, landing followed by resting and transient resting during normal walking. In addition, different gaits can be inferred from well-preserved D. gouldi, which can be correlated with contrasting trackway morphology. 相似文献
116.
Ricardo D. Ekmay Catalina Salas Judy England Sandro Cerrate Craig N. Coon 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2013,164(1):38-43
A study was conducted to determine the changes that occur to proteolysis and related genes due to age, protein, and energy intake in high-yield broiler breeder hens (Gallus gallus). Cobb 700 broiler breeders were randomly assigned to one of six diets in a 2 × 3 factorial fashion. Two levels of energy (390 and 450 kcal/day) and three levels of protein (22, 24, and 26 g CP/day) were utilized. Protein turnover was determined in the left pectoralis at 22, 26, 31 and 44 weeks. Relative mRNA expression of calpain 2 (CAPN2), proteasome C2 subunit (PSMA1), and F box protein 32 (FBXO32) were determined via RT-PCR at 20, 25, and 44 weeks. Contrasts indicate fractional synthesis rate (FSR) and FBXO32 increase to a maximum at 25–26 weeks and a decrease thereafter. A significant drop in PSMA1 and FBXO32 was observed between 25 and 44 weeks and matched the decrease observed in FBR. No differences were detected in the levels of fractional synthesis and degradation, or the expression of CAPN2, PSMA1, and FBXO32, due to protein or energy intake. In summary, protein turnover was upregulated during the transition into sexual maturity and decreased thereafter. The observed changes in degradation appeared to be mediated by the ubiquitin–proteasome pathway. 相似文献
117.
118.
119.
Carmen Gómez-Vaquero Alfonso Corrales Andrea Zacarías Javier Rueda-Gotor Ricardo Blanco Carlos González-Juanatey Javier Llorca Miguel A González-Gay 《Arthritis research & therapy》2013,15(4):R91
Introduction
Our objective was to determine which one of the two function charts available in Spain to calculate cardiovascular (CV) risk, Systematic COronary Risk Evaluation (SCORE) or Framingham-REgistre GIroní del COR (REGICOR), should be used in patients with rheumatoid arthritis (RA).Methods
A series of RA patients seen over a one-year period without history of CV events were assessed. SCORE, REGICOR, modified (m)SCORE and mREGICOR according to the European League Against Rheumatism (EULAR) recommendations were applied. Carotid ultrasonography (US) was performed. Carotid intima-media thickness (cIMT) > 0.90 mm and/or carotid plaques were used as the gold standard test for severe subclinical atherosclerosis and high CV risk (US+). The area under the receiver operating curves (AUC) for the predicted risk for mSCORE and mREGICOR were calculated according to the presence of severe carotid US findings (US+).Results
We included 370 patients (80% women; mean age 58.9 ± 13.7 years); 36% had disease duration of 10 years or more; rheumatoid factor (RF) and/or anticyclic citrullinated peptide (anti-CCP) were positive in 68%; and 17% had extra-articular manifestations. The EULAR multiplier factor was used in 122 (33%) of the patients. The mSCORE was 2.16 ± 2.49% and the mREGICOR 4.36 ± 3.46%. Regarding US results, 196 (53%) patients were US+. The AUC mSCORE was 0.798 (CI 95%: 0.752 to 0.844) and AUC mREGICOR 0.741 (95% CI; 0.691 to 0.792). However, mSCORE and mREGICOR failed to identify 88% and 91% of US+ patients. More than 50% of patients with mSCORE ≥1% or mREGICOR >1% were US+.Conclusions
Neither of these two function charts was useful in estimating CV risk in Spanish RA patients. 相似文献120.
Leandro Freire dos Santos Ana Lucia Zanatta Vanete Thomaz Soccol Maria Fernanda Torres Sandro José Ribeiro Bonatto Rosália Rubel Carlos Ricardo Soccol 《Biotechnology and Bioprocess Engineering》2013,18(1):201-208
The ability of Pleurotus ostreatus biomass, cultived by submerged fermentation, to produce beneficial effect on lipid profile and macrophages activity during a high-fat diet (HFD) for a long-term intake was investigated. Blood samples were collected through cardiac puncture to measure the plasma cholesterol, triglycerides, low-density protein (LDL), high-density protein (HDL), aspartate aminotransferase (AST) activity, urea-blood urea nitrogen (BUN)/creatinine ratio of rats fed on an HFD for 4 months. Dosage of lipid hydroperoxides was carried out on methanolic extract of liver tissue. Peritoneal macrophages activity was evaluated in relation to the superoxide anion, hydrogen peroxide and nitric oxide production, phagocytosis and lysosomal volume. The administration of P. ostreatus significantly altered the lipid profile and oxidative stress as related to the LDL and triglycerides decrease and inhibitory effects on superoxide anion and hydrogen peroxide production. All findings of this study lead us to suggest that the P. ostreatus maybe a beneficial agent in the hyperlipidemia and atherosclerosis treatments. 相似文献