全文获取类型
收费全文 | 3528篇 |
免费 | 250篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 125篇 |
妇产科学 | 43篇 |
基础医学 | 466篇 |
口腔科学 | 69篇 |
临床医学 | 350篇 |
内科学 | 866篇 |
皮肤病学 | 72篇 |
神经病学 | 204篇 |
特种医学 | 455篇 |
外科学 | 447篇 |
综合类 | 33篇 |
一般理论 | 2篇 |
预防医学 | 197篇 |
眼科学 | 31篇 |
药学 | 186篇 |
中国医学 | 7篇 |
肿瘤学 | 229篇 |
出版年
2023年 | 13篇 |
2022年 | 36篇 |
2021年 | 67篇 |
2020年 | 50篇 |
2019年 | 73篇 |
2018年 | 73篇 |
2017年 | 55篇 |
2016年 | 54篇 |
2015年 | 62篇 |
2014年 | 97篇 |
2013年 | 133篇 |
2012年 | 168篇 |
2011年 | 202篇 |
2010年 | 112篇 |
2009年 | 117篇 |
2008年 | 154篇 |
2007年 | 158篇 |
2006年 | 121篇 |
2005年 | 147篇 |
2004年 | 122篇 |
2003年 | 127篇 |
2002年 | 107篇 |
2001年 | 86篇 |
2000年 | 89篇 |
1999年 | 90篇 |
1998年 | 73篇 |
1997年 | 70篇 |
1996年 | 81篇 |
1995年 | 64篇 |
1994年 | 47篇 |
1993年 | 60篇 |
1992年 | 62篇 |
1991年 | 65篇 |
1990年 | 60篇 |
1989年 | 67篇 |
1988年 | 75篇 |
1987年 | 55篇 |
1986年 | 66篇 |
1985年 | 71篇 |
1984年 | 37篇 |
1983年 | 39篇 |
1982年 | 37篇 |
1981年 | 38篇 |
1980年 | 20篇 |
1979年 | 23篇 |
1978年 | 15篇 |
1977年 | 35篇 |
1976年 | 32篇 |
1975年 | 25篇 |
1969年 | 9篇 |
排序方式: 共有3807条查询结果,搜索用时 15 毫秒
71.
A J Yates G E Gutierrez I R Garrett J J Mencel G W Nuss A B Schreiber G R Mundy 《Endocrinology》1990,126(6):2845-2849
A new analog of salmon calcitonin (N alpha-propionyl Di-Ala1,7,des-Leu19 sCT; RG-12851; here termed CTR), which lacks the ring structure of native calcitonin, was tested for biological activity in several in vitro and in vivo assay systems. The analog (CTR) and salmon calcitonin (sCT) stimulated kidney cell adenylate cyclase activity and inhibited bone resorption in organ cultures of fetal rat long bones with similar potencies and efficacies. Furthermore, CTR and sCT, at similar doses, induced comparable hypocalcemic responses in mice following sc injection or infusions. However, unlike sCT, CTR did not induce anorexia and weight loss in rats following sc injection. These data suggest that the ring structure of sCT may be important for the anorexigenic effect but is not required for effect on bone resorption or calcium homeostasis. Clinical studies appear warranted as, potentially, CTR might induce fewer side effects than does sCT. 相似文献
72.
73.
74.
BAX and BCL‐2 polymorphisms,as predictors of proliferative vitreoretinopathy development in patients suffering retinal detachment: the Retina 4 project 下载免费PDF全文
Salvador Pastor‐Idoate Irene Rodríguez‐Hernández Jimena Rojas Itziar Fernández María‐Teresa García‐Gutierrez Jose M. Ruiz‐Moreno Amandio Rocha‐Sousa Yashin D. Ramkissoon Steven Harsum Robert E. MacLaren David G. Charteris Jan C. Van Meurs Rogelio González‐Sarmiento Jose C. Pastor the Genetics on PVR Study Group 《Acta ophthalmologica. Supplement》2015,93(7):e541-e549
75.
P Morentin Gutierrez A Gyte J deSchoolmeester P Ceuppens J Swales C Stacey J W Eriksson M Sj?strand C Nilsson B Leighton 《British journal of pharmacology》2015,172(20):4806-4816
Background and Purpose
11β‐hydroxysteroid dehydrogenase type I (11β‐HSD1), a target for Type 2 diabetes mellitus, converts inactive glucocorticoids into bioactive forms, increasing tissue concentrations. We have compared the pharmacokinetic‐pharmacodynamic (PK/PD) relationship of target inhibition after acute and repeat administration of inhibitors of 11β‐HSD1 activity in human, rat and mouse adipose tissue (AT).Experimental Approach
Studies included abdominally obese human volunteers, rats and mice. Two specific 11β‐HSD1 inhibitors (AZD8329 and COMPOUND‐20) were administered as single oral doses or repeat daily doses for 7–9 days. 11β‐HSD1 activity in AT was measured ex vivo by conversion of 3H‐cortisone to 3H‐cortisol.Key Results
In human and rat AT, inhibition of 11β‐HSD1 activity was lost after repeat dosing of AZD8329, compared with acute administration. Similarly, in rat AT, there was loss of inhibition of 11β‐HSD1 activity after repeat dosing with COMPOUND‐20 with continuous drug cover, but effects were substantially reduced if a ‘drug holiday’ period was maintained daily. Inhibition of 11β‐HSD1 activity was not lost in mouse AT after continuous cover with COMPOUND‐20 for 7 days.Conclusions and Implications
Human and rat AT, but not mouse AT, exhibited tachyphylaxis for inhibition of 11β‐HSD1 activity after repeat dosing. Translation of observed efficacy in murine disease models to human for 11β‐HSD1 inhibitors may be misleading. Investigators of the effects of 11β‐HSD1 inhibitors should confirm that desired levels of enzyme inhibition in AT can be maintained over time after repeat dosing and not rely on results following a single dose.Abbreviations
- 11β‐HSD1
- 11β‐hydroxysteroid dehydrogenase type I
- PK/PD
- pharmacokinetic‐pharmacodynamic
- AT
- adipose tissue
- DIO
- diet induced obese
- IHC
- International Conference on Harmonisation
- GCP
- Good Clinical Practice
- b.i.d.
- twice daily
- u.i.d.
- once daily
- HPMC
- hydroxypropylmethylcellulose
- IC70
- concentration that delivers 70% of the maximum effect
- IC90
- concentration that delivers 90% of the maximum effect
- fu
- fraction unbound
- Cmax
- maximum achieved concentration
- Cmin
- minimum or trough concentration
- E0
- baseline
- Emax
- maximum effect
- ANCOVA
- analysis of covariance
76.
Olascoaga-Del Angel Kevin Samael Gutierrez Humberto Knigsberg Mina Prez-Villanueva Jaime Lpez-Diazguerrero Norma Edith 《Biogerontology》2022,23(4):453-471
Biogerontology - Senescent cells accumulate within tissues during aging and secrete an array of pro-inflammatory molecules known as senescent-associated secretory phenotype (SASP), which contribute... 相似文献
77.
Rectification of the remnants of the leaflets--a new surgical technique to avoid periprosthetic leaks in aortic valve replacement 总被引:2,自引:0,他引:2
F Alonso-Lej L Carreras C Lopez F Ibarra A Gutierrez F Martinez 《The Thoracic and cardiovascular surgeon》1986,34(3):153-156
During the last 12 years, we have used a modified suture technique for aortic valve replacement in 450 patients in order to avoid periprosthetic leaks. There were 420 survivors, and reoperation for periprosthetic leaks was necessary in no instance. The "secret" of our technique consists of the uniform distribution of the tensile forces among all sutures, eliminating uneven stresses that favors tearing of the tissues or rupture of the stitches. 相似文献
78.
Histological patterns of gastritis in H. pylori-infected individuals with a family history of gastric cancer 总被引:9,自引:0,他引:9
Sepulveda A Peterson LE Shelton J Gutierrez O Graham DY 《The American journal of gastroenterology》2002,97(6):1365-1370
OBJECTIVE: Different types of chronic gastritis, including antral predominant, corpus predominant, and multifocal pangastritis, are associated with Helicobacter pylori infection. Specific patterns of H. pylori gastritis that might characterize individuals with family histories of noncardia gastric cancer (GC) were investigated. METHODS: Histopathological changes associated with H. pylori gastritis were assessed in 111 individuals with family histories of GC and in 77 without from a region with high prevalence of H. pylori infection and GC. Gastric biopsies were taken from 12 sites (antrum, five; corpus, six; and cardia, one). RESULTS: Individuals (age < 36 yr) with family histories of GC developed pangastritis and had higher H. pylori bacterial scores (p < 0.05) in the gastric corpus, whereas those without family histories of GC typically had antral predominant gastritis. The correlation between density of polymorphonuclear leukocytes and density of H. pylori at each biopsy site was statistically significant (p < 0.01). Pangastritis was associated with a higher density of lymphoid aggregates and follicles (p < 0.05) in the corpus of younger individuals (age < 36) and in the antrum of older individuals (age > or = 48) with positive family histories of GC. CONCLUSIONS: Pangastritis and high lymphoid follicle density associated with H. pylori infection were found in patients with family histories of GC. Because a family history of gastric carcinoma is associated with increased risk of gastric cancer development, characterization of histological patterns of gastritis may be applicable to gastric cancer screening and surveillance, especially in relatively young at-risk populations. 相似文献
79.
80.
Solano C Gutierrez A Martinez F Gimeno C Gómez C Muñoz I Faus F Goterris R Farga A Navarro D 《Bone marrow transplantation》2005,36(1):59-65
The safety and efficacy of early bacterial prophylaxis with piperacillin-tazobactam were prospectively evaluated in 51 autologous peripheral blood stem cell transplantation (PBSCT) recipients. The results were compared with those obtained in 51 control patients receiving oral fluoroquinolones in a retrospective matched-pair control study. Overall, 76% of the study group and 98% of the control group developed at least one febrile episode during neutropenia (P=0.002). Time from neutropenia to the first febrile episode (FFE) was significantly longer in the study group than in the control group (P=0.04). Once a febrile episode appeared, the duration of fever was significantly longer in cases than in controls (median of 5 and 2 days respectively, P<0.001), and led to a more frequent use of empirical amphotericin B (AmB), not statistically significant (P=0.13). However, the total time of antibiotic administration was significantly greater in the control than in the study group (P=0.05). The duration of AmB treatment shows a trend toward a longer duration in the control than in study group (P=0.2). Overall, 86% of the Gram-positive bacteremia and 85% of the Gram-negative bacteria were susceptible to the tested antibiotics. Our study suggests that a subgroup of patients could benefit from prophylaxis with piperacillin-tazobactam without increasing toxicity or bacterial resistance. 相似文献