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   2350369篇
  免费   171241篇
  国内免费   3343篇
耳鼻咽喉   32055篇
儿科学   75899篇
妇产科学   62685篇
基础医学   348196篇
口腔科学   63635篇
临床医学   211359篇
内科学   457358篇
皮肤病学   51727篇
神经病学   185280篇
特种医学   88006篇
外国民族医学   489篇
外科学   353868篇
综合类   47509篇
现状与发展   12篇
一般理论   848篇
预防医学   182769篇
眼科学   54325篇
药学   175124篇
  11篇
中国医学   4575篇
肿瘤学   129223篇
  2021年   18981篇
  2019年   19541篇
  2018年   27061篇
  2017年   20358篇
  2016年   22750篇
  2015年   25645篇
  2014年   36097篇
  2013年   53963篇
  2012年   74690篇
  2011年   79411篇
  2010年   47058篇
  2009年   44572篇
  2008年   74625篇
  2007年   79496篇
  2006年   80305篇
  2005年   77801篇
  2004年   74377篇
  2003年   71697篇
  2002年   69370篇
  2001年   108745篇
  2000年   111460篇
  1999年   93503篇
  1998年   26991篇
  1997年   23659篇
  1996年   24057篇
  1995年   22717篇
  1994年   20893篇
  1993年   19712篇
  1992年   72004篇
  1991年   70072篇
  1990年   68396篇
  1989年   65669篇
  1988年   60310篇
  1987年   59130篇
  1986年   55219篇
  1985年   53005篇
  1984年   39314篇
  1983年   33398篇
  1982年   19858篇
  1979年   35866篇
  1978年   25652篇
  1977年   21230篇
  1976年   20332篇
  1975年   21816篇
  1974年   26148篇
  1973年   24802篇
  1972年   23200篇
  1971年   22037篇
  1970年   20247篇
  1969年   19316篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
Pharmaceutical Chemistry Journal - N-Substituted 4-aryl-2-hydroxy-4-oxobut-2-enoic acid hydrazides and their complexes with Ni(II), Mn(II), Co(II), Cu(II), and Zn(II) were prepared. Their...  相似文献   
182.

Objective

To explore from a gender perspective the association with subjective health of the interaction between education and household arrangements within the framework of social determinants of health placed at the micro and mezzo levels.

Methods

The data comes from the Spanish sample of the European Union Statistics on Income and Living Conditions for 2014. Independent logistic regression models for men and women were run to analyze the association with subjective health of the interaction between education and household arrangements. An additive model was run to assess possible advantages over the interaction approach.

Results

The interaction models show a lower or even no significant effect on health of household arrangements usually negatively associated with health among individuals with high education, displaying specific patterns according to sex.

Conclusions

Health profiles of women and men are more precisely drawn if both social determinants of health are combined. Among the women, the important role was confirmed of both social determinants of health in understanding their health inequalities. Among the men, mainly those with low educational achievement, the interaction revealed that the household was a more meaningful social determinant of health. This could enable the definition of more efficient public policies to reduce health and gender inequalities.  相似文献   
183.
Parhiala  P.  Ranta  K.  Gergov  V.  Kontunen  J.  Law  R.  La Greca  A. M.  Torppa  M.  Marttunen  M. 《School mental health》2020,12(2):265-283

In order to offer early and accessible treatment for adolescents with depression, brief and effective treatments in adolescents’ everyday surroundings are needed. This randomized controlled trial studied the preliminary effectiveness, feasibility, and acceptability of interpersonal counseling (IPC) and brief psychosocial support (BPS) in school health and welfare services. The study was conducted in the 28 lower secondary schools of a large city in Southern Finland, randomized to provide either IPC or BPS. Help-seeking 12–16-year-old adolescents with mild-to-moderate depression, with and without comorbid anxiety, were included in the study. Fifty-five adolescents received either 6 weekly sessions of IPC or BPS and two follow-up sessions. Outcome measures included self- and clinician-rated measures of depression, global functioning, and psychological distress/well-being. To assess feasibility and acceptability of the treatments, adolescents’ and counselors’ treatment compliance and satisfaction with treatment were assessed. Both treatments were effective in reducing depressive disorders and improving adolescents’ overall functioning and well-being. At post-treatment, in both groups, over 50% of adolescents achieved recovery based on self-report and over 70% based on observer report. Effect sizes for change were medium or large in both groups at post-treatment and increased at 6-month follow-up. A trend indicating greater baseline symptom severity among adolescents treated in the IPC-providing schools was observed. Adolescents and counselors in both groups were satisfied with the treatment, and 89% of the adolescents completed the treatments and follow-ups. This trial suggests that both IPC and BPS are feasible, acceptable, and effective treatments for mild-to-moderate depression in the school setting. In addition, IPC seems effective even if comorbid anxiety exists. Our study shows that brief, structured interventions, such as IPC and BPS, are beneficial in treating mild-to-moderate depression in school settings and can be administered by professionals working at school.

Trial registrationhttp://www.clinicaltrials.gov. Unique identifier: NCT03001245.

  相似文献   
184.
Abstract

Purpose: In the context of assistive technology, mobility takes the meaning of “moving safely, gracefully, and comfortably”.The aim of this article is to provide a system which will be a convenient means of navigation for the Visually Impaired people, in the public transport system.

Method: A blind regular commuter who travels by public transport facility finds difficulty in identifying the vehicle that is nearing the stop. Hence, a real-time system that dynamically identifies the nearing vehicle and informs the commuters is necessary. This paper proposes such a system namely the “Vehicle Board Recognition System” (VBRS). Computer Vision techniques such as segmentation, object recognition, text detection and optical character recognition are utilized to build the system, which will detect, analyze, derive and communicate the information to the passengers.

Results: Thanks to the rapid development in technology, there are several navigation systems both hand held and wearable, available to help visually impaired (VI) people move comfortably both indoor and outdoor. Many blind people are not comfortable in using these devices or they are not affordable for them. Thus the proposed system gives them the comfort of navigation.

Conclusion: This system can be installed in the bus stop to assist the Visually Impaired, from externally rather than their hand held or wearable assistive devices.
  • Implications for rehabilitation
  • This proposed system will help the visually impaired to

  • ensure secure navigation

  • be independent of the others

  • develop self confidence.

  • overcome the training, affordability of wearable/ handheld devices.

  相似文献   
185.
Since the introduction of cART (combination antiretroviral therapy), HIV has evolved into a chronic disease such that it requires lifelong medical treatment to which patients must adhere. Communication with health care providers is pivotal in supporting patients to adapt to having HIV and adhering to treatment, in order to maintain health and quality of life. Previous research indicates that communication is optimal when it matches patient preferences for information exchange, relationship establishment, and involvement in treatment decisions. The aim of the present study is to explore HIV patient communication preferences as well as patient experiences with their providers (not) matching their preferences. A second aim is to explore provider beliefs about patient preferences and provider views on optimal communication. Data were collected through interviews with 28 patients and 11 providers from two academic hospitals. Results indicate that patient preferences reflect their cognitive, emotional, and practical needs such that patients look to increase their sense of control over their HIV. Patients aim to further increase their sense of control (by proxy) through their relationship with their providers and through their decisional involvement preferences. Providers are well aware of patient communication preferences but do not explicate underlying control needs. Implications for clinical practice are discussed.  相似文献   
186.

This study sought to evaluate the antioxidant properties and effects of some edible wild seeds [Afzelia africana Sm. (AFZ), Cyperus esculentus L. (CYP), Eleusine coracana Gaertn. (ELE), Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill. (IRV), Monodora myristica Dunal. (MON) and Parinari curatellifolia Planch. ex Benth. (PAR)] on α-amylase and α-glucosidase activities. The phenolic content and antioxidant activities of aqueous extracts of the seeds as typified by 1,1-diphenyl-2 picrylhydrazyl (DPPH) and hydroxyl (OH) radicals scavenging abilities and inhibition of Fe2+-induced malondialdehyde (MDA) production in rat’s pancreas in vitro were also assessed. ELE had significantly (p < 0.05) higher total phenol content than the other seeds; however, AFZ had the highest flavonoid content. The extracts scavenged DPPH· and OH· in a dose-dependent manner with aqueous extracts of PAR having the highest DPPH· scavenging ability, while extracts from IRV had the highest OH· scavenging ability and inhibition of Fe2+-induced MDA production in rat’s pancreas. Furthermore, all the extracts inhibited α-amylase and α-glucosidase activities in a dose-dependent manner. The α-amylase inhibitory effect of MON (IC50 = 0.48 mg/mL) was comparable to that of acarbose (IC50 = 0.40 mg/mL), while the α-glucosidase inhibitory effect of AFZ (IC50 = 0.45 mg/mL) was comparable to that of acarbose (IC50 = 0.39 mg/mL). The results suggest the potential use of the seeds in the dietary management of blood glucose levels associated with type 2 diabetes.

  相似文献   
187.

Background and aims

Since accelerated atherosclerosis has been reported in systemic lupus erythematosus (SLE), predictive biomarkers of cardiovascular disease (CVD) are needed. Among non-traditional risk factors, bone mineral density (BMD) has been related to CVD. However, its role in SLE remains controversial. This study aims to analyze the associations of subclinical atherosclerosis with traditional and non-traditional CV risk factors.

Methods and results

In a cross-sectional study, atherosclerosis burden was compared between 112 female SLE patients and 31 controls. Plaque number and carotid intima-media wall thickness (cIMT) were assessed by ultrasonography. In a retrospective study, BMD determinations obtained 5-years before the ultrasonography assessment were analyzed in a subgroup of 62 patients. Plaque frequency was increased in SLE, even in patients without CV events or carotid wall thickening. cIMT was increased in patients with CVD, positively correlated with body mass index (BMI). Interestingly, a paradoxical effect of BMI on carotid parameters was observed. Whereas underweight patients (BMI < 20) showed increased prevalence of carotid plaques with low cIMT, those with BMI > 30 showed higher cIMT and plaque burden. Overweight patients (25 < BMI<30) exhibited both elevated cIMT and plaque number. BMI was an independent predictor of BMD. In our retrospective study, patients with either clinical or subclinical CVD exhibited lower BMD levels than their CV-free counterparts. A low lumbar spine BMD independently predicted CVD development after adjusting for confounders.

Conclusion

SLE was associated with a higher subclinical atherosclerosis burden, a bimodal effect being observed for BMI. Decreased BMD can be a CV risk biomarker in SLE.  相似文献   
188.
Quality of Life Research - Health-related quality of life (HRQoL) is an important indicator of population health, yet no age-specific trend analyses in HRQoL have been conducted with a nationally...  相似文献   
189.
The Latin American population has a double way of immigration, one toward the United States by proximity and another toward Spain by sociocultural affinity. This population increase is affecting organ donation and transplantation in receiving countries.

Objective

To analyze the brain death (BD) concept knowledge in the Dominican Republic immigrant population in Florida (United States) and Spain.

Method

Population under study: Population born in the Dominican Republic, resident in Florida (United States) and in Spain. Inclusion criteria: Population older than 15 years stratified by age and sex. Assessment instrument: Donation attitude questionnaire PCID-DTO-Ríos. Fieldwork: Random selection based on stratification. Immigration support association collaboration in Florida and Spain was needed to locate potential respondents. Completion was anonymous and self-administered, with verbal consent.

Results

A total of 123 respondents, 57 residents in Spain and 66 in Florida, have been included in the study. The 27% (n = 33) of the respondents knowledgeable of the BD concept consider it the death of an individual. Of the remainder, 52% (n = 64) do not know about it, and the remaining 21% (n = 26) believe it does not mean the death of a patient. No differences were observed regarding migration countries (P > .05). There was no association of the BD concept with other psychosocial factors analyzed or with the attitude toward organ donation.

Conclusions

Knowledge of the BD concept among the Dominican immigrant population is similar in Spain and Florida, and, unlike most studies, there is no objective association with the attitude toward organ donation.  相似文献   
190.
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