全文获取类型
收费全文 | 15484篇 |
免费 | 1209篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 337篇 |
儿科学 | 465篇 |
妇产科学 | 314篇 |
基础医学 | 2109篇 |
口腔科学 | 297篇 |
临床医学 | 1564篇 |
内科学 | 2857篇 |
皮肤病学 | 118篇 |
神经病学 | 1776篇 |
特种医学 | 649篇 |
外科学 | 2531篇 |
综合类 | 218篇 |
一般理论 | 10篇 |
预防医学 | 1333篇 |
眼科学 | 472篇 |
药学 | 913篇 |
中国医学 | 11篇 |
肿瘤学 | 764篇 |
出版年
2023年 | 66篇 |
2022年 | 130篇 |
2021年 | 354篇 |
2020年 | 194篇 |
2019年 | 309篇 |
2018年 | 393篇 |
2017年 | 310篇 |
2016年 | 286篇 |
2015年 | 323篇 |
2014年 | 476篇 |
2013年 | 681篇 |
2012年 | 1024篇 |
2011年 | 992篇 |
2010年 | 608篇 |
2009年 | 474篇 |
2008年 | 829篇 |
2007年 | 886篇 |
2006年 | 922篇 |
2005年 | 870篇 |
2004年 | 723篇 |
2003年 | 779篇 |
2002年 | 708篇 |
2001年 | 298篇 |
2000年 | 266篇 |
1999年 | 274篇 |
1998年 | 191篇 |
1997年 | 130篇 |
1996年 | 149篇 |
1995年 | 99篇 |
1994年 | 102篇 |
1993年 | 96篇 |
1992年 | 192篇 |
1991年 | 196篇 |
1990年 | 190篇 |
1989年 | 161篇 |
1988年 | 145篇 |
1987年 | 170篇 |
1986年 | 136篇 |
1985年 | 146篇 |
1984年 | 122篇 |
1983年 | 107篇 |
1982年 | 84篇 |
1981年 | 84篇 |
1980年 | 78篇 |
1979年 | 90篇 |
1978年 | 90篇 |
1977年 | 73篇 |
1976年 | 75篇 |
1974年 | 80篇 |
1972年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Suchi Raghunathan Corey L. Reynolds Robert J. Schwartz M. David Stewart Bradley K. McConnell 《Fundamental & clinical pharmacology》2019,33(1):25-30
Inbred mouse strains are the most widely used mammalian model organism in biomedical research owing to ease of genetic manipulation and short lifespan; however, each inbred strain possesses a unique repertoire of deleterious homozygous alleles that can make a specific strain more susceptible to a particular disease. In the current study, we report dystrophic cardiac calcinosis (DCC) in C.B‐17 SCID male mice at 10 weeks of age with no significant change in cardiac function. Acquisition of DCC was characterized by myocardial injury, fibrosis, calcification, and necrosis of the tissue. At 10 weeks of age, 38% of the C.B‐17 SCID mice from two different commercial colonies exhibited significant calcinosis on the ventricular epicardium, predominantly on the right ventricle. The frequency of calcinosis was more than 50% for mice obtained from Taconic's Cambridge City colony and 25% for mice obtained from Taconic's German Town colony. Interestingly, the DCC phenotype did not affect cardiac function at 10 weeks of age. No differences in echocardiography or electrocardiography were observed between the calcinotic and non‐calcinotic mice from either colony. Our findings suggest that C.B‐17 SCID mice exhibit DCC as early as 10 weeks of age with no significant impact on cardiac function. This strain of mice should be cautiously considered for the study of cardiac physiology. 相似文献
4.
5.
Bimal Bhindi Christine M. Lohse Phillip J. Schulte Ross J. Mason John C. Cheville Stephen A. Boorjian Bradley C. Leibovich R. Houston Thompson 《European urology》2019,75(5):766-772
Background
Partial nephrectomy (PN) is generally favored for cT1 tumors over radical nephrectomy (RN) when technically feasible. However, it can be unclear whether the additional risks of PN are worth the magnitude of renal function benefit.Objective
To develop preoperative tools to predict long-term estimated glomerular filtration rate (eGFR) beyond 30 d following PN and RN, separately.Design, setting, and participants
In this retrospective cohort study, patients who underwent RN or PN for a single nonmetastatic renal tumor between 1997 and 2014 at our institution were identified. Exclusion criteria were venous tumor thrombus and preoperative eGFR <15 ml/min/1.73 m2.Intervention
RN and PN.Outcome measurements and statistical analysis
Hierarchical generalized linear mixed-effect models with backward selection of candidate preoperative features were used to predict long-term eGFR following RN and PN, separately. Predictive ability was summarized using marginal , which ranges from 0 to 1, with higher values indicating increased predictive ability.Results and limitations
The analysis included 1152 patients (13 206 eGFR observations) who underwent RN and 1920 patients (18 652 eGFR observations) who underwent PN, with mean preoperative eGFRs of 66 ml/min/1.73 m2 (standard deviation [SD] = 18) and 72 ml/min/1.73 m2 (SD = 20), respectively. The model to predict eGFR after RN included age, diabetes, preoperative eGFR, preoperative proteinuria, tumor size, time from surgery, and an interaction between time from surgery and age (marginal ). The model to predict eGFR after PN included age, presence of a solitary kidney, diabetes, hypertension, preoperative eGFR, preoperative proteinuria, surgical approach, time from surgery, and interaction terms between time from surgery and age, diabetes, preoperative eGFR, and preoperative proteinuria (marginal ). Limitations include the lack of data on renal tumor complexity and the single-center design; generalizability needs to be confirmed in external cohorts.Conclusions
We developed preoperative tools to predict renal function outcomes following RN and PN. Pending validation, these tools should be helpful for patient counseling and clinical decision-making.Patient summary
We developed models to predict kidney function outcomes after partial and radical nephrectomy based on preoperative features. This should help clinicians during patient counseling and decision-making in the management of kidney tumors. 相似文献6.
7.
Management of sphenoid sinus cerebrospinal fluid rhinorrhea: making use of an extended approach to the sphenoid sinus. 总被引:2,自引:0,他引:2
Neelesh H Mehendale Bradley F Marple Brian Nussenbaum 《Otolaryngology--head and neck surgery》2002,126(2):147-153
OBJECTIVES: Specific information addressing the management of cerebrospinal fluid (CSF) fistulas that originate from within the sphenoid sinus remains scant. The objective of this study was to review the cause and management of CSF rhinorrhea arising from the sphenoid sinus. STUDY DESIGN AND SETTING: This is a retrospective chart review of 12 cases of CSF rhinorrhea arising from the sphenoid sinus that occurred in 11 patients. All patients were treated at a single institution between 1994 and 1999. RESULTS: All patients were managed surgically with sphenoid sinus fat obliteration using an endoscopic sublabial, transseptal approach. This approach was successful for all 12 cases, with median duration of follow-up of 18 months. CONCLUSIONS: Endoscopically assisted transseptal repair of CSF fistulas that originate within the sphenoid sinus offers an alternate approach to previously described methods of repair in this region. Advantages include wide access to the entire sphenoid sinus, improved access to laterally pneumatized regions within the sphenoid sinus, and rostral mucosal closure over the repair within the sinus. 相似文献
8.
Bradley J Catalone Shendra R Miller Mary Lee Ferguson Dan Malamud Tina Kish-Catalone Nina J Thakkar Fred C Krebs Mary K Howett Brian Wigdahl 《Biomedicine & Pharmacotherapy》2005,59(8):430-437
C31G, which has potent activity against the human immunodeficiency virus type 1 (HIV-1) and an established record of safety in animal studies and human trials, is a microbicidal agent comprised of a buffered equimolar mixture of two amphoteric, surface-active agents: an alkyl amine oxide (C14AO) and an alkyl betaine (C16B). Studies of long-term in vitro exposure to C31G and its constituents have suggested that the components of C31G may contribute differentially to its toxicity and efficacy. In the present studies, in vitro assays of cytotoxicity and anti-HIV-1 activity demonstrated that C16B was slightly less cytotoxic compared to either C31G or C14AO, whereas the anti-HIV-1 activities of C31G and its individual constituents were similar. In the murine model of cervicovaginal microbicide toxicity, in vivo exposure to C14AO resulted in severe cervical inflammation followed by a delayed disruption of the columnar epithelium. In contrast, exposure to C16B caused severe cervical epithelial disruption and a secondary, less intense inflammatory response. These results demonstrate that (i) there are both mechanistic and temporal differences in toxicity associated with the components of C31G not necessarily predicted by in vitro assessments of cytotoxicity and (ii) contributions of each component to the anti-HIV-1 activity of C31G appear to be equal. In addition, these findings indicate that direct and indirect mechanisms of in vivo toxicity can be observed as separate but interrelated events. These results provide further insight into the activity of C31G, as well as mechanisms potentially associated with microbicide toxicity. 相似文献
9.
Nerve growth factor (NGF) and NGF receptors were measured in cortex and hippocampus of rats treated with drugs affecting cholinergic neurotransmission. High (Kd= 0.045nM) and low (Kd= 21nM) affinity125I-NGF binding sites were present in both cortical and hippocampal membranes with hippocampus containing higher numbers of both sites than cortex. Chronic treatment of rats with the muscarinic receptor antagonist scopolamine (5 mg/kg, twice daily) decreased the density of high- and low-affinity sites by 50–90% in cortical and hippocampal membranes. These changes were seen after 7 days, but not 3 days, of scopolamine treatment. Chronic infusion of physostigmine (1 mg/kg/day) using minipumps increased the number of high- and low-affinity sites in cortex 3- and 6-fold, respectively. The changes in receptor-binding parameters induced by physostigmine were transient as they were evident after 3 days of treatment, but returned to control levels after 7 days. NGF content in cortex and hippocampus was reduced by about 50% following 7, but not 3, days of chronic physostigmine infusion. In contrast, scopolamine treatment failed to change NGF levels in the cholinergic neuronal target regions but it decreased NGF content in the septal area. The content of NGF mRNA in the cortex measured by Northern blot analysis failed to change following either scopolamine or physostigmine treatment. The results suggest that levels of NGF and NGF receptors in the target regions of cholinergic neurons are regulated by the extent of cholinergic neurotransmitter activity. 相似文献
10.