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   11800篇
  免费   752篇
  国内免费   60篇
耳鼻咽喉   61篇
儿科学   423篇
妇产科学   361篇
基础医学   1694篇
口腔科学   231篇
临床医学   1256篇
内科学   2508篇
皮肤病学   222篇
神经病学   1199篇
特种医学   170篇
外科学   1195篇
综合类   79篇
一般理论   8篇
预防医学   1265篇
眼科学   293篇
药学   788篇
中国医学   42篇
肿瘤学   817篇
  2024年   11篇
  2023年   83篇
  2022年   220篇
  2021年   426篇
  2020年   232篇
  2019年   349篇
  2018年   394篇
  2017年   271篇
  2016年   283篇
  2015年   370篇
  2014年   494篇
  2013年   621篇
  2012年   990篇
  2011年   1039篇
  2010年   553篇
  2009年   482篇
  2008年   845篇
  2007年   841篇
  2006年   767篇
  2005年   712篇
  2004年   600篇
  2003年   557篇
  2002年   531篇
  2001年   98篇
  2000年   62篇
  1999年   71篇
  1998年   77篇
  1997年   53篇
  1996年   48篇
  1995年   49篇
  1994年   32篇
  1993年   36篇
  1992年   34篇
  1991年   29篇
  1990年   27篇
  1989年   23篇
  1988年   21篇
  1987年   28篇
  1986年   24篇
  1985年   22篇
  1984年   10篇
  1983年   15篇
  1982年   16篇
  1981年   16篇
  1980年   13篇
  1979年   10篇
  1977年   11篇
  1976年   12篇
  1970年   9篇
  1966年   13篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
961.
962.
Major depressive disorder (MDD) is among the most prevalent neuropsychiatric disorders associated with HIV infection; however, its risks and neurobiologic correlates in diverse cultures are poorly understood. This study aimed to examine the frequency of MDD among HIV+ participants in southern Brazil. We hypothesized that the frequency and severity of MDD would be higher among individuals with HIV+ compared with HIV? and higher in HIV subtype B compared with C. Individuals with HIV (n?=?39) as well as seronegative controls (n?=?22) were enrolled in a cross-sectional, prospective, observational study. Current and lifetime history of MDD was diagnosed by MINI-Plus; symptom severity was assessed by Beck Depression Inventory-II (BDI-II). Current and past episodes of MDD were significantly more frequent in the HIV+ versus HIV? group: current MDD, 15 (38.5 %) vs. 0 (0 %), p?=?0.0004; past MDD, 24 (61.5 %) vs. 3 (13.6 %), p?=?0.0004. The median BDI-II score in the HIV+ group was significantly higher than that in the HIV? (13 (8–27.5) vs. 2.5 (1–5.5); p?<?0.0001). Current suicide risk, defined as during the last month, was found in 18 % of participants in the HIV-positive and none in the HIV-negative group. Neither current MDD frequency (8 (57.1 %) vs. 6 (40 %), p?=?0.47) nor BDI-II score differed across subtypes B and C. HIV+ group may be more likely to experience current MDD than HIV?. This was the first study to compare the frequency and severity of MDD in HIV subtypes B and C; we found no difference between HIV subtypes B and C.  相似文献   
963.
Parenting is a key life role for many adults living with serious mental illness who are, most likely, supported best in their treatment and recovery efforts when their family context is taken into consideration. However, providers and agencies traditionally serving individual adults may be challenged in working with adults who are parents as they begin taking family roles and members into account. In this article, the implementation of the Family Options intervention for families living with parental mental illness is described, along with critical domains of challenge that emerged while shifting the host agency’s paradigm from focusing on individuals to focusing on families. Ethnographic interview data regarding implementation were obtained from multiple perspectives at multiple points in time over 2 years (n?=?100), in the context of a larger developmental hybrid design (implementation and outcomes) study. Results from rigorous thematic analysis suggest the importance of attending to workforce, organizational, and community capacities in shifting an agency’s paradigm to adopt a family-focused intervention; in implementing the intervention with fidelity to the model; and in anticipating replication of the intervention to build the evidence base.  相似文献   
964.
Arylsulfatase A (ASA) is a lysosomal enzyme involved in the catabolism of cerebroside sulfate. ASA deficiency is associated with metachromatic leukodystrophy (MLD). Low ASA activities have also been reported in a more common condition with no apparent clinical consequences termed ASA pseudo-deficiency (ASA-PD) which is associated with two linked mutations in the ASA gene (c.1049A>G and c.*96A>G). This study aimed to investigate the frequency of the two ASA-PD variants and their linkage disequilibrium (LD) among Tunisians. ASA-PD variants were detected in 129 healthy Tunisians and their frequencies were compared to those described worldwide. The frequency of the PD allele was estimated at 17.4 % for the overall sample, with c.1049A>G and c.*96A>G frequencies of 25.6 and 17.4 %, respectively. This study also revealed a high LD between the two ASA-PD variants (r 2 = 0.61). Inter-population analysis revealed similarities in the ASA-PD genetic structure between Tunisians and populations from Middle East with c.*96A>G frequencies being the highest in the world. A significant North vs. South genetic differentiation in the ASA-PD frequency was also observed in Tunisian population who seems genetically intermediate between Africans, Middle-Easterners and Europeans. This is the first report on the allele frequency of the ASA-PD in North Africa, revealing a relatively high frequency of the PD allele among Tunisians. This study gives also evidence on the importance of discriminating ASA-PD allele from pathological mutations causing MLD and supporting enzymatic activity testing with both sulfatiduria determination and genetic testing in the differential diagnosis of MLD in the Tunisian population.  相似文献   
965.
966.
Chemotherapy‐induced peripheral neuropathy (CIPN) is a frequent adverse event. Nutritional status can become impaired in cancer patients, potentially contributing to neuropathy's evolution. Our aim was to evaluate serum micronutrients and prealbumin in a cohort of 113 solid‐cancer patients receiving platinum and taxane compounds during the development and recovery of neuropathy, up to 1 year after finishing treatment. CIPN was graded according to Total Neuropathy Score© and NCI.CTCv3 at T0 (baseline), T1 (1–3 months), and T12 (12 months) after chemotherapy. CIPN was classified as asymptomatic (< grade 2) or symptomatic (≥2). CIPN recovery was defined as ≥1 grade improvement at T12. Symptomatic CIPN developed in 52% of patients. Symptomatic patients presented a higher increase in TNSc (p < 0.001), in TNSr© (p < 0.001), and decrease in sural (p < 0.001) and radial nerve conduction (p < 0.001). No significant differences with any of the micronutrients were observed along T0‐T1 period between severity or chemotherapy groups. By T12, symptomatic patients without recovery had a decrease in vitamin E levels (p = 0.019) and prealbumin (p = 0.062) compared with those symptomatic that improved. A correlation between the variation of vitamin E and prealbumin at T0‐T1 (r = 0.626, p = 0.001) and T1‐T12 (r = 0.411, p = 0.06) was observed. After chemotherapy treatment, the improvement of patients displaying symptomatic neuropathy is related to vitamin E and prealbumin serum levels. Our results suggest that nutritional status can play a role in CIPN recovery.  相似文献   
967.
Phenytoin is a widely used antiepileptic drug that induces cell proliferation in several tissues, such as heart, bone, skin, oral mucosa and neural precursors. Some of these effects are mediated via fibroblast growth factor receptor (FGFR) and epidermal growth factor receptor (EGFR). These receptors are strongly expressed in the adult ventricular–subventricular zone (V‐SVZ), the main neurogenic niche in the adult brain. The aim of this study was to determine the cell lineage and cell fate of V‐SVZ neural progenitors expanded by phenytoin, as well as the effects of this drug on EGFR/FGFR phosphorylation. Male BALB/C mice received 10 mg/kg phenytoin by oral cannula for 30 days. We analysed the proliferation of V‐SVZ neural progenitors by immunohistochemistry and western blot. Our findings indicate that phenytoin enhanced twofold the phosphorylation of EGFR and FGFR in the V‐SVZ, increased the number of bromodeoxyuridine (BrdU)+/Sox2+ and BrdU+/doublecortin+ cells in the V‐SVZ, and expanded the population of Olig2‐expressing cells around the lateral ventricles. After phenytoin removal, a large number of BrdU+/Receptor interacting protein (RIP)+ cells were observed in the olfactory bulb. In conclusion, phenytoin enhanced the phosphorylation of FGFR and EGFR, and promoted the expression of neural precursor markers in the V‐SVZ. In parallel, the number of oligodendrocytes increased significantly after phenytoin removal.  相似文献   
968.
Abstract

People with severe mental illness (SMI) have high prevalence of lifetime victimization, but little is known about the extent and risk of recent domestic/sexual violence. The objective was to synthesize evidence on prevalence, odds, and risk factors for recent violence against people with SMI, with a focus on domestic and sexual violence. Relevant studies were identified through literature searches in Medline, Psychinf, Embase (for studies published in 2010–2015), and through existing systematic reviews (for studies published in 2000–2014). The review included 30 studies (with 16 140 SMI participants), including six on domestic violence and 11 on sexual violence. Prevalence of recent domestic violence ranged from 15–22% among women and from 4–10% among men/mixed samples; with little evidence on risk compared with the general population. Median prevalence of sexual violence was 9.9% (IQR?=?5.9–18.1%) in women and 3.1% (IQR?=?2.5–6.7%) in men; with 6-fold higher odds of victimization compared with the general population. There was little evidence on risk factors for domestic or sexual violence. In conclusion, people with SMI have a high prevalence of recent domestic and sexual violence, but little is known about risk factors for these violence types, or extent of domestic violence victimization compared to the general population.  相似文献   
969.
970.
P-selectin glycoprotein ligand-1 (PSGL-1) mediates rolling of leukocytes on P-selectin under flow. The glycoproteins that enable leukocyte tethering to or rolling on E-selectin are not known. We used gene targeting to prepare PSGL-1-deficient (PSGL-1-/-) mice, which were healthy but had moderately elevated total blood leukocytes. Fluid-phase E-selectin bound to approximately 70% fewer sites on PSGL-1-/- than PSGL-1+/+ neutrophils. Compared with PSGL-1+/+ leukocytes, significantly fewer PSGL-1-/- leukocytes rolled on E-selectin in vitro, because their initial tethering to E-selectin was impaired. The residual cells that tethered rolled with the same shear resistance and velocities as PSGL-1+/+ leukocytes. Compared with PSGL-1+/+ mice, significantly fewer PSGL-1-/- leukocytes rolled on E-selectin in TNF-alpha-treated venules of cremaster muscle in which P-selectin function was blocked by an mAb. The residual PSGL-1-/- leukocytes that tethered rolled with slow velocities equivalent to those of PSGL-1+/+ leukocytes. These results reveal a novel function for PSGL-1 in tethering leukocytes to E-selectin under flow.  相似文献   
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