首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   12261篇
  免费   677篇
  国内免费   55篇
耳鼻咽喉   85篇
儿科学   484篇
妇产科学   285篇
基础医学   1852篇
口腔科学   212篇
临床医学   1341篇
内科学   2573篇
皮肤病学   240篇
神经病学   1236篇
特种医学   308篇
外科学   1147篇
综合类   77篇
一般理论   9篇
预防医学   1021篇
眼科学   216篇
药学   879篇
中国医学   50篇
肿瘤学   978篇
  2024年   12篇
  2023年   89篇
  2022年   205篇
  2021年   348篇
  2020年   216篇
  2019年   307篇
  2018年   363篇
  2017年   245篇
  2016年   280篇
  2015年   369篇
  2014年   478篇
  2013年   676篇
  2012年   976篇
  2011年   1034篇
  2010年   538篇
  2009年   483篇
  2008年   795篇
  2007年   853篇
  2006年   787篇
  2005年   756篇
  2004年   677篇
  2003年   663篇
  2002年   596篇
  2001年   68篇
  2000年   54篇
  1999年   89篇
  1998年   119篇
  1997年   104篇
  1996年   70篇
  1995年   73篇
  1994年   60篇
  1993年   46篇
  1992年   44篇
  1991年   35篇
  1990年   24篇
  1989年   25篇
  1988年   31篇
  1987年   20篇
  1986年   28篇
  1985年   25篇
  1984年   32篇
  1983年   38篇
  1982年   39篇
  1981年   41篇
  1980年   33篇
  1979年   23篇
  1978年   22篇
  1977年   12篇
  1976年   11篇
  1975年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
The endeavor to study desensitization in kidney transplantation has not been matched by an effort to investigate strategies to prevent sensitization. In this study (NCT02437422), we investigated the safety, impact on sensitization, and pharmacokinetics of SANGUINATE (SG), a hemoglobin‐based oxygen carrier, as a potential alternative to packed red blood cells (PRBC) in transplant candidates with end‐stage renal disease (ESRD). Ten ESRD subjects meeting inclusion/exclusion (I/E) criteria were planned to receive three weekly infusions of SG (320 mg/kg). The study was stopped after five subjects were enrolled, and their data were analyzed after completing a follow‐up period of 90 days. Two subjects had elevated troponin I levels in setting of SG infusion, one of which was interpreted as a non‐ST elevation myocardial infarction. All other adverse events were transient. SG pharmacokinetic analysis showed mean (SD) Cmax, Tmax, AUC, and half‐life of 4.39 (0.69) mg/mL, 2.42 (0.91) hours, 171.86 (52.35) mg h/mL, and 40.60 (11.96) hours, respectively. None of the subjects developed new anti‐HLA antibodies following SG infusion and throughout the study period. In conclusion, SG is a potential alternative to PRBCs in ESRD patients considered for kidney transplantation as it was not associated with humoral sensitization. Larger studies in highly sensitized patients are required to further evaluate for potential safety signals.  相似文献   
34.

Introduction

Various definitions for bariatric surgery (BS) success exist, with weight loss and comorbidity resolution outcomes being the most prominent. The study’s aim was to compare how various healthcare professionals perceive success in BS.

Methods

A 29-item, 10-point Likert scale online survey was distributed via email to Israeli healthcare professionals involved in the different BS aspects using common national professional organizations. These included bariatric surgeons, dietitians, social workers, psychologists, psychiatrists, primary care physicians, gastroenterologists, and nurses. Statement relevancy to BS success was rated. An item was classed as “very important” for BS success if at least 70% of participants rated it 8 or higher in each subgroup. Inter-observer agreement was calculated using kappa statistics. Data on specific occupation, years-in-practice, and major workplace were collected as well.

Results

A total of 155 responses was obtained. The majority of respondents were dietitians (34.8%, n = 54), followed by bariatric surgeons (31.0%, n = 48) and nurses (14.8%, n = 23). Most respondents work mainly at public hospitals (32.9%, n = 51), followed by private hospitals (26.5%, n = 41). The mean years-in-practice among all healthcare professionals was 8.5 ± 8.5 years. Overall inter-observer agreement for prioritized items in accordance to BS success among all health professional subgroups was fair (Fleiss kappa = 0.278, P < 0.001), while dietitians and mental health specialists showed the highest agreement rate (Cohen’s kappa = 0.592, P < 0.001).

Conclusion

The study highlights the various views on defining BS success by different healthcare professionals, although there was some overlap of core outcomes prioritized by all professionals. International uniform definitions for BS success are required.
  相似文献   
35.
The Food and Drug Administration (FDA) held a public meeting and scientific workshop in September 2016 to obtain perspectives from solid organ transplant recipients, family caregivers, and other patient representatives. The morning sessions focused on the impact of organ transplantation on patients’ daily lives and the spectrum of activities undertaken to maintain grafts. Participants described the physical, emotional, and social impacts of their transplant on daily life. They also discussed their posttransplant treatment regimens, including the most burdensome side effects and their hopes for future treatment. The afternoon scientific session consisted of presentations on prevalence and risk factors for medication nonadherence after transplantation in adults and children, and interventions to manage it. As new modalities of Immunosuppressive Drug Therapy are being developed, the patient perceptions and input must play larger roles if organ transplantation is to be truly successful.  相似文献   
36.
37.
Peroxisomes play a crucial role in normal neurodevelopment and in the maintenance of the adult brain. This depends largely on intact peroxisomal β‐oxidation given the similarities in pathologies between peroxisome biogenesis disorders and deficiency of multifunctional protein‐2 (MFP2), the central enzyme of this pathway. Recently, adult patients diagnosed with cerebellar ataxia were shown to have mild mutations in the MFP2 gene, hydroxy‐steroid dehydrogenase (17 beta) type 4 (HSD17B4). Cerebellar atrophy also develops in MFP2 deficient mice but the cellular origin of the degeneration is unexplored. In order to investigate whether peroxisomal β‐oxidation is essential within Purkinje cells, the sole output neurons of the cerebellum, we generated and characterized a mouse model with Purkinje cell selective deletion of the MFP2 gene. We show that selective loss of MFP2 from mature cerebellar Purkinje neurons causes a late‐onset motor phenotype and progressive Purkinje cell degeneration, thereby mimicking ataxia and cerebellar deterioration in patients with mild HSD17B4 mutations. We demonstrate that swellings on Purkinje cell axons coincide with ataxic behavior and precede neurodegeneration. Loss of Purkinje cells occurs in a characteristic banded pattern, proceeds in an anterior to posterior fashion and is accompanied by progressive astro‐ and microgliosis. These data prove that the peroxisomal β‐oxidation pathway is required within Purkinje neurons to maintain their axonal integrity, independent of glial dysfunction.  相似文献   
38.

Introduction

One of the most common sites of distant metastasization of prostate cancer is bone, but to date reliable biomarkers able to predict the risk and timing of bone metastasization are still lacking.

Patients and methods

Surgically resected paraffin embedded samples from 12 primary prostate cancers that developed metachronous bone metastasis at different time points were studied (six cases within 2 years, six cases after 5 years from surgery). A targeted next-generation DNA and RNA sequencing able to assess simultaneously mutations, copy number alterations and fusion events of multiple genes was used. Immunohistochemistry was used to assess mTOR pathway activation.

Results

Rearrangements of ETS family genes, molecular alterations in PTEN and TP53 genes were detected in 10, 6 and 5 cancers, respectively. Nine samples showed TMPRSS2-ERG fusions, which were associated with increased ERG expression at immunohistochemistry. mTOR pathway activation was documented in 6 patients, with a clear trend of prevalence in late-metastatic patients (p?=?0.08).

Conclusions

A simultaneous next-generation targeted DNA and RNA sequencing is applicable on routine formalin-fixed paraffin-embedded tissues to assess the multigene molecular asset of individual prostate cancers. This approach, coupled with immunohistochemistry for ERG and mTOR pathway proteins, may help to better characterize prostate cancer molecular features with a potential impact on clinical decisions.  相似文献   
39.
Euchroma Dejean, 1833 (Buprestidae: Coleoptera) is a monotypic genus comprising the species Euchroma gigantea, with populations presenting a degree of karyotypic variation/polymorphism rarely found within a single taxonomic (specific) unit, as well as drastically incompatible meiotic configurations in populations from extremes of the species range. To better understand the complex karyotypic evolution of E. gigantea, the karyotypes of specimens from five populations in Brazil were investigated using molecular cytogenetics and phylogenetic approaches. Herein, we used FISH with histone genes as well as sequencing of the COI to determine differential distribution of markers and relationships among populations. The analyses revealed new karyotypes, with variability for chromosome number and morphology of multiple sex chromosome mechanisms, occurrence of B chromosome variants (punctiform and large ones), and high dispersion of histone genes in different karyotypes. These data indicate that chromosomal polymorphism in E. gigantea is greater than previously reported, and that the species can be a valuable model for cytogenetic studies. The COI phylogenetic and haplotype analyses highlighted the formation of three groups with chromosomally polymorphic individuals. Finally, we compared the different karyotypes and proposed a model for the chromosomal evolution of this species. The species E. gigantea includes at least three cytogenetically polymorphic lineages. Moreover, in each of these lineages, different chromosomal rearrangements have been fixed. Dispersion of repetitive sequences may have favored the high frequency of these rearrangements, which could be related to both adaptation of the species to different habitats and the speciation process.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号