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   6594篇
  免费   323篇
  国内免费   20篇
耳鼻咽喉   80篇
儿科学   358篇
妇产科学   93篇
基础医学   799篇
口腔科学   139篇
临床医学   395篇
内科学   1445篇
皮肤病学   215篇
神经病学   304篇
特种医学   183篇
外科学   1073篇
综合类   201篇
一般理论   3篇
预防医学   389篇
眼科学   308篇
药学   410篇
中国医学   34篇
肿瘤学   508篇
  2023年   44篇
  2022年   129篇
  2021年   211篇
  2020年   125篇
  2019年   113篇
  2018年   151篇
  2017年   115篇
  2016年   147篇
  2015年   179篇
  2014年   254篇
  2013年   293篇
  2012年   458篇
  2011年   478篇
  2010年   251篇
  2009年   222篇
  2008年   362篇
  2007年   401篇
  2006年   376篇
  2005年   322篇
  2004年   288篇
  2003年   256篇
  2002年   250篇
  2001年   133篇
  2000年   147篇
  1999年   121篇
  1998年   64篇
  1997年   42篇
  1996年   35篇
  1995年   41篇
  1994年   15篇
  1993年   25篇
  1992年   81篇
  1991年   67篇
  1990年   76篇
  1989年   65篇
  1988年   53篇
  1987年   56篇
  1986年   54篇
  1985年   60篇
  1984年   47篇
  1983年   27篇
  1981年   24篇
  1980年   17篇
  1979年   30篇
  1978年   28篇
  1977年   19篇
  1976年   15篇
  1975年   20篇
  1974年   15篇
  1971年   18篇
排序方式: 共有6937条查询结果,搜索用时 15 毫秒
141.
142.

Objective

To determine predictors of disability depending on whether joint deformity and pain reporting exist independently or concurrently.

Methods

Subjects were 154 volunteers for an osteoarthritis screening examination. Eligible subjects completed questionnaires for physical function, pain, and depressive symptoms; underwent evoked pain testing for tenderness assessment; and had anteroposterior and lateral radiographs taken of both knees. Two blinded rheumatologists scored the images using Kellgren‐Lawrence criteria to determine presence of deformity.

Results

Subjects were divided into 3 subgroups based on radiographic evidence of deformity and self‐reported pain. Disability was greatest when pain and deformity occurred together (F[2,151] = 18.8, P < 0.0001). Self‐reported disability in the absence of deformity was predicted by body mass index, pain threshold, and anxiety symptoms; disability was predicted by the number of osteophytes and depressive symptoms when pain and deformity occurred together.

Conclusion

Self‐reported disability in osteoarthritis of the knee is greatest with concurrent pain and joint deformity. When pain and deformity do not cooccur, disability appears to be related to separate factors, including anxiety and pain threshold (e.g., tenderness).
  相似文献   
143.

Objective

Granulomatosis with polyangiitis (Wegener's) (GPA) is a systemic necrotizing vasculitis in which pulmonary nodules are a common manifestation. Our study examined whether pulmonary nodules, and nodule type (solid versus cavitary), are associated with different disease manifestations and outcomes.

Methods

Demographic, clinical, biologic, and radiologic data at diagnosis and during followup and treatments of GPA patients followed at the Mount Sinai Hospital (Canada) Vasculitis Clinic were analyzed. Patients were separated by the absence of lung nodules, presence of solid nodules only, and presence of cavitary nodules (+/? solid nodules). The study outcomes included followup lung imaging, relapses, and deaths.

Results

Of 225 patients with GPA, 46 had solid nodules only and 44 had cavitary nodules at diagnosis. Demographic and clinical manifestations were similar in the patient subgroups at diagnosis. Cyclophosphamide (CYC) was used for induction after diagnosis in 76.7% of patients with cavitary nodules, compared with 64.7% of patients without nodules and 51.1% of patients with solid nodules (P = 0.04). The mean ± SD followup after diagnosis was 106.6 ± 92.6 months, and 6 of the patients died. In multivariable analysis, diagnosis before 2000 or pulmonary nodule cavitation at diagnosis were associated with relapse, with a hazard ratio of 0.38 (95% confidence interval [95% CI] 0.22–0.65; P < 0.001) and 1.53 (95% CI 1.00–2.33; P = 0.05), respectively, after adjustment for CYC use.

Conclusion

The presence of cavitary nodules led to increased use of CYC but had no impact on survival. Relapse occurred more often, however, in patients with cavitary nodules than in those with solid nodules or no nodules, and should be studied in other cohorts.
  相似文献   
144.
145.
The current study aims at the development of an electrochemical sensor based on a silver nanoparticle–reduced graphene oxide–polyaniline (AgNPs–rGO–PANI) nanocomposite for the sensitive and selective detection of hydrogen peroxide (H2O2). The nanocomposite was fabricated by simple in situ synthesis of PANI at the surface of rGO sheet which was followed by stirring with AEC biosynthesized AgNPs to form a nanocomposite. The AgNPs, GO, rGO, PANI, rGO–PANI, and AgNPs–rGO–PANI nanocomposite and their interaction were studied by UV-vis, FTIR, XRD, SEM, EDX and XPS analysis. AgNPs–rGO–PANI nanocomposite was loaded (0.5 mg cm−2) on a glassy carbon electrode (GCE) where the active surface area was maintained at 0.2 cm2 for investigation of the electrochemical properties. It was found that AgNPs–rGO–PANI–GCE had high sensitivity towards the reduction of H2O2 than AgNPs–rGO which occurred at −0.4 V vs. SCE due to the presence of PANI (AgNPs have direct electronic interaction with N atom of the PANI backbone) which enhanced the rate of transfer of electron during the electrochemical reduction of H2O2. The calibration plots of H2O2 electrochemical detection was established in the range of 0.01 μM to 1000 μM (R2 = 0.99) with a detection limit of 50 nM, the response time of about 5 s at a signal-to-noise ratio (S/N = 3). The sensitivity was calculated as 14.7 μA mM−1 cm−2 which indicated a significant potential as a non-enzymatic H2O2 sensor.

The current study aims at the development of an electrochemical sensor based on a silver nanoparticle–reduced graphene oxide–polyaniline (AgNPs–rGO–PANI) nanocomposite for the sensitive and selective detection of hydrogen peroxide (H2O2).  相似文献   
146.

Objective

Evidence has linked economic hardship with increased intimate partner violence (IPV) perpetration among males. However, less is known about how economic debt or gender norms related to men''s roles in relationships or the household, which often underlie IPV perpetration, intersect in or may explain these associations. We assessed the intersection of economic debt, attitudes toward gender norms, and IPV perpetration among married men in India.

Methods

Data were from the evaluation of a family planning intervention among young married couples (n=1,081) in rural Maharashtra, India. Crude and adjusted logistic regression models for dichotomous outcome variables and linear regression models for continuous outcomes were used to examine debt in relation to husbands'' attitudes toward gender-based norms (i.e., beliefs supporting IPV and beliefs regarding male dominance in relationships and the household), as well as sexual and physical IPV perpetration.

Results

Twenty percent of husbands reported debt. In adjusted linear regression models, debt was associated with husbands'' attitudes supportive of IPV (b=0.015, p=0.004) and norms supporting male dominance in relationships and the household (b=0.006, p=0.003). In logistic regression models adjusted for relevant demographics, debt was associated with perpetration of physical IPV (adjusted odds ratio [AOR] = 1.4, 95% confidence interval [CI] 1.1, 1.9) and sexual IPV (AOR=1.6, 95% CI 1.1, 2.1) from husbands. These findings related to debt and relation to IPV were slightly attenuated when further adjusted for men''s attitudes toward gender norms.

Conclusion

Findings suggest the need for combined gender equity and economic promotion interventions to address high levels of debt and related IPV reported among married couples in rural India.Intimate partner violence (IPV) perpetrated by male partners or husbands occurs in high proportions globally as well as in low- to middle-income countries such as India.1,2 One recent multi-country household study found that 37% of men in India reported having ever perpetrated physical violence against a female intimate partner in their lifetime. The health burden of IPV has been well demonstrated, with significant effects on women''s sexual and reproductive health (e.g., increased sexually transmitted infections, unintended pregnancy, and poor pregnancy outcomes),35 mental health (e.g., anxiety, depression, and substance use),6,7 as well as a multitude of other poor health outcomes among women and their children (e.g., maternal and child malnutrition and infant death).8,9Recent research among women has identified economic hardship (e.g., financial dependence on male partners and economic instability) as increasing women''s vulnerability to IPV.10,11 Although studies have found an association between economic stressors and reports of male IPV perpetration,1216 no research has examined debt in relation to these outcomes.Debt and other economic decisions in the context of marriage, particularly in rural India, are largely under the control of husbands. Taking on debt may be associated with economic hardship, heightening stress levels among men, and, in turn, IPV. Also, previous work documenting the association between economic hardship and increased IPV perpetration by males1215 has largely been explained by perceptions related to men''s roles financially within the family (e.g., men who do not feel that they are providing financially for their families may perceive that they are not fulfilling their roles as husbands/males, and this perception related to lack of role fulfillment may escalate into violence). Given that a decision to take on debt appears to be largely controlled by men in this context and likely tied to their perceived role of providing financially for the family, a man''s decision to take out loans may be determined, in part, by their support of masculine gender norms (e.g., a man''s role in the family and male dominance and control in the household). In addition, given previous work highlighting the association between masculine gender norms and a number of risk behaviors among boys and men (e.g., substance and tobacco use and behaviors resulting in unintentional injury),1721 such gender norms may also be linked to taking on risks associated with debt, as well as debt-acquiring behaviors (e.g., spending money on nonessential goods such as alcohol).Gender norms pertaining to IPV, relationships, and the household are also important driving factors in terms of understanding men''s behaviors related to IPV. Cross-cultural research has shown that societies with greater gender inequities in social norms and policies have a higher prevalence of IPV.21 In the context of India and elsewhere, women''s low status in families and high levels of societal tolerance and acceptance of IPV promote IPV.22More research is needed to understand economic hardship, and debt specifically, in relation to attitudes toward gender norms and IPV perpetration. Many studies have hypothesized that stress related to economic hardship and debts increases IPV perpetration;1215 however, less research has sought to understand the role of attitudes supportive of men''s more traditional gender norms in relationships or households in contributing to decisions to take on debt as well as in terms of explaining its association with increased IPV perpetration. Increased understanding of the mechanisms that explain associations between economic hardship/debt and IPV is needed to inform prevention approaches, particularly given the increasing number of economic promotion interventions being implemented globally and throughout India.Thus, the primary objective of the current study was to assess household debt in relation to husbands'' support of gender-inequitable norms and norms promoting IPV as well as husbands'' use of IPV against wives. The secondary objective of this study was to assess whether or not gender-based attitudes are important factors in debt and IPV, as well as in explaining an association between debt and increased risk for IPV perpetration among husbands.  相似文献   
147.
Gay adoptive fathers and their children are becoming more visible in American society. Consequently, a deeper understanding is needed of the challenges and opportunities gay fathers experience in social interactions. Using a phenomenological approach, gay adoptive fathers from 20 families were interviewed about their experiences parenting as gay men. Although fathers led fulfilling lives as parents, many of them faced uninvited social interactions that reminded them of their place in a heterosexual order. These reminders of heteronormativity included scrutiny about their parenting, concerns about the well‐being of their children, and decisions regarding disclosing information about their families. This article illustrates the use of a social constructionist lens to understand the emotional burdens gay adoptive fathers carry navigating these interactions in public settings. By narrowing the focus on such encounters, this article attunes practitioners and educators to gay fathers' emotional worlds while deepening their understanding of the social fabric of heteronormativity.  相似文献   
148.
The concept of defining essential medicines and establishing a list of them was aimed to improve the availability of affordable medicines for the world''s poor. Access to essential medicines is a major determinant of health outcomes. Several countries have made substantial progress towards increasing access to essential medicines, but access to essential medicines in developing countries like India is not adequate. In this review we have tried to present the Indian scenario in respect to availability and accessibility of essential medicines over last one decade. To enhance the credibility of Indian healthcare system, procurement and delivery systems of essential medicines have to be strengthened through government commitment, careful selection, adequate public sector financing, efficient distribution systems, control on taxes and duties, and inculcating a culture of rational use of medicines in current and future prescribers.  相似文献   
149.
Though F1 hybrids are not the immediate cultivar option, development of heterotic F1 hybrids is relevant from view point of deriving pure lines, the only cultivar choice in dolichos bean, a predominantly self-pollinated grain legume crop species. Heterotic F1 generates a high frequency of productive derivatives in F3 and later generations as compared to non-heterotic F1. The criteria such as combining ability and genetic diversity between parents are being commonly used to develop heterotic hybrids. In this context, an investigation was carried out at University of Agricultural Sciences, Bengaluru, India, to test the predictability of frequency of heterotic hybrids based on parental gca effects and genetic diversity in dolichos bean. The 48 F1 hybrids generated by crossing 12 lines and 4 testers were evaluated along with their parents for 6 quantitative characters. The overall gca status (high and low) of each parent and overall sca and heterotic status (high and low) of each hybrid for 6 characters were determined. Based on overall gca status and genetic divergence of parents, the hybrids were grouped into different classes. The hybrids involving parents contrasting for overall gca status and/or those involving parents with intermediate genetic divergence were more frequently heterotic than those involving comparable gca status with extreme genetic divergence. Thus, there exists a limit to parental divergence for the occurrence of heterosis. It is hence, desirable to involve parents with intermediate genetic divergence and contrasting gca effects to recover higher frequencies of heterotic hybrids for economic traits in dolichos bean.  相似文献   
150.
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