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   1517732篇
  免费   95500篇
  国内免费   3077篇
耳鼻咽喉   20906篇
儿科学   46905篇
妇产科学   41764篇
基础医学   205517篇
口腔科学   41496篇
临床医学   125375篇
内科学   293742篇
皮肤病学   30999篇
神经病学   123288篇
特种医学   62618篇
外国民族医学   435篇
外科学   237486篇
综合类   34782篇
现状与发展   6篇
一般理论   462篇
预防医学   110136篇
眼科学   34148篇
药学   110423篇
  32篇
中国医学   3741篇
肿瘤学   92048篇
  2018年   33490篇
  2017年   26556篇
  2016年   29838篇
  2015年   13954篇
  2014年   18778篇
  2013年   27769篇
  2012年   40847篇
  2011年   55124篇
  2010年   39449篇
  2009年   31887篇
  2008年   52391篇
  2007年   57384篇
  2006年   38234篇
  2005年   38464篇
  2004年   38574篇
  2003年   38239篇
  2002年   35947篇
  2001年   63950篇
  2000年   65862篇
  1999年   55708篇
  1998年   14982篇
  1997年   13772篇
  1996年   13100篇
  1995年   12359篇
  1994年   11604篇
  1992年   42850篇
  1991年   41425篇
  1990年   40726篇
  1989年   39675篇
  1988年   37059篇
  1987年   36477篇
  1986年   34952篇
  1985年   33156篇
  1984年   24866篇
  1983年   21083篇
  1982年   12718篇
  1981年   11581篇
  1979年   23931篇
  1978年   17078篇
  1977年   14846篇
  1976年   13404篇
  1975年   15284篇
  1974年   18100篇
  1973年   17566篇
  1972年   16812篇
  1971年   15732篇
  1970年   14946篇
  1969年   14374篇
  1968年   13494篇
  1967年   12027篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.

Background

Ukraine, one of the largest states formed on the rubble of the Soviet Union, is widely perceived as a country that has lost its opportunities. Being devastated by corruption, it shows incapable to modernize and enter the economic path of sustainable growth. Similarly in the health care system no deeper reform efforts have been taken in the entire post-soviet period, leaving the system in bonds of ineffective solutions taken out of the Soviet era.

Main body

The recent geopolitical and economic crisis seem to favor the introduction of radical solutions that might lead to a rapid change in the organizational paradigm of the economic system, as well as in health care in Ukraine. In this paper we aim to highlight the key features of the ongoing health reform in Ukraine, identify basic challenges for it, and assess rationality and feasibility of the reform. We found that the projected scope and schedule of changes in the Ukrainian health system give promising prognosis regarding its final effect.

Conclusions

The final success of health reform in Ukraine is dependent on a number of factors, including the financial foundation arising of economic stability of the country, balance assurance between public and private spending for health and ability to eliminate the long-lasting practices, particularly when they are connected with activities of lobbying groups occupying particular positions in the health system. A consequence of actions taken by the political decision-makers in the longer perspective are also to highly determine the reform’s chances for success.
  相似文献   
92.

Background

Wearing a pollution mask is an effective, practical, and economic way to prevent the inhalation of dangerous particulate matter (PM). However, it is not uncommon to observe negligence in adopting such behaviour, and this especially among young segments of the population. Using the Theory of Planned Behaviour (TPB) as conceptual framework, this study explores the role of socio-cognitive factors that affect the decision of wearing a pollution mask in the context of young educated people. This is done by selecting a sample of college students in urban China, a country that has seen air quality as one of the major challenges in the last decades. While young urban college students might be expected to be receptive to standard attempts to be influenced through reason-based cognitive stimuli, it is often found that this is not the case. The empirical analysis was articulated it in two steps. Structural Equation Modelling (SEM) was first used to examine the relationships among the conceptual constructs derived from the TPB conceptual model, and second Step-Wise Ordinary Least Squares Regressions (SWOLS) were employed to observe the partial effect played by each item on the decision to wear a mask.

Results

Results show that, while reason-based stimuli play a role, attitude, social norm, and self-efficacy were the most important predictors of the behavioural intention (p?<?0.01). The role of past behaviour was also acknowledged as strongly associated with the dependent variable (p?<?0.01). Overall, the likelihood of wearing a pollution mask increases with the importance of others socio-cognitive and psychological factors, which could help understand behavioural biases, and explain the relative role of several mechanisms behind the decision to wear a mask.

Conclusions

While tackling pollution requires multiple and synergic approaches, encouraging self-prevention using pollution mask is a simple and effective action, implementable at negligible costs. Resistance among younger, well-educated cohorts to wear masks can be overcome by stressing the social desirability of action and the sense of empowerment derived from its usage. This study has the potential to inform policies aimed at changing suboptimal behavioural attitudes by identifying triggers for change, and it could serve in improving the tailoring of health promotion messages aimed at nudging healthy behaviour.
  相似文献   
93.
This article describes a twinning relationship between the Canadian Association of Midwives (CAM) and the Tanzania Midwives Association (TAMA). It argues that the twinning relationship strengthened both associations. The article briefly reviews the existing literature on professional associations and association strengthening to demonstrate that professional associations are a vital tool for improving the performance of healthcare workers and increasing their capacity to contribute to national and international policy-making. It then suggests that midwifery associations are particularly significant given the frequent professional marginalization of midwives. The article then describes in depth the relationship between CAM and TAMA, highlighting the accomplishments of the twinned partners, and analyzing the factors that contributed to the success of the relationship. The findings demonstrate that twinning can successfully strengthen associations, increasing their ability to support their membership, care for the public, and shape national policy-making. The article therefore proposes twinning as a successful and cost-effective model for encouraging the growth of the midwifery profession.  相似文献   
94.

Background

Carbon monoxide (CO) is formed as a result of the incomplete burning of hydrocarbon-containing fuels such as natural gas, coal, liquid petroleum gas, and wood. CO is a colorless, odorless, and poisonous gas that produces various acute and chronic effects in CO-exposed people. In this study, we aimed to measure CO levels in auto care repairmen with chronic CO-related illnesses using a serial, non-invasive method.A prospective cohort study.

Methods

A total of 99 people from six different auto-repair services were included in the study. Carboxyhemoglobin (COHb) levels were measured at four different times with 2-hour intervals starting at 08:00 AM. Data concerning employees’ ages, working hours, smoking statuses, and types of home heating fuel were collected. A control group of 100 cases was created based on this data. The measurements were done on the control group in the morning with a Masimo Rad-57 CO-oximeter.

Results

The highest mean (± SD) COHb value was 7.04%?±?3.32% after the third measurement. The mean value for the control group was 1.61%?±?1.43%. A statistically significant difference between the groups was found for each value.

Discussion

We determined that the risk of being affected by CO is high in buildings in which the auto services were located. The effects of chronic or prolonged exposure to low amounts of CO were found to be ambiguous. However, in some studies, it was found that low-grade CO exposure could lead to coronary artery disease and some neurological complications. Therefore, it is necessary to be careful about the health of employees who have been exposed to CO.

Conclusions

We concluded that there is a need for more detailed studies concerning chronic CO poisoning. Also, in workplaces in which there is high exposure to CO, proper workplace safety measures should be taken to reduce this gas’s harmful effects to employees.
  相似文献   
95.

Background

So far, studies within the occupational field have largely concentrated on working conditions and job stressors and staff members’ or subordinate health. Only a few have focused on managers in this context, but studies are missing that explicitly look at the relation between leadership position and health care use (HCU). Thus, the purpose of this study was to examine the potential effects of a change in leadership position on HCU in women and men longitudinally.

Methods

Data were drawn from a nationally representative longitudinal study in Germany (German Socio-Economic Panel, GSOEP). Data from 2009 and 2013 were used. Leadership position was divided into (i) top management, (ii) middle management, (iii) lower management, and (iv) a highly qualified specialist position. The number of physician visits in the preceding 3 months were used to quantify HCU (n?=?2140 observations in regression analysis; 69% male).

Results

Adjusting for various potential confounders (e.g., age, self-rated health, chronic conditions, and personality factors), Poisson FE regression analysis revealed that changes from a highly qualified specialist position to the top management were associated with a decrease in the number of physician visits in men (β?=?.47, p?<?.05), but not in women. Gender differences (gender x leadership position) were significant.

Conclusions

Findings of this study emphasize the impact of leadership positions on the number of physician visits in men. Further study is required to elucidate the underlying mechanisms.
  相似文献   
96.

Background

Medical rehabilitation plays a special role in the treatment of children and adolescents with diabetes mellitus: services which are difficult to implement in an out-patient or an acute in-patient setting can be provided. The study analyzed changes over a period of 12 years.

Methods

In a monocentric, retrospective cross-sectional analysis, all (n = 2001) children and adolescents with diabetes (52% girls, age 12.6 ± 4.9 years) who were admitted to a specialist clinic for rehabilitation during the period 01/2004–12/2016 were examined.

Results

The duration of medical rehabilitation was 27.3 ± 6.1 days. In all, 1980 of 2001 (98.9%) children and adolescents had type 1 diabetes, while 21 of 2001 (1.1%) had type 2 diabetes. Mean HbA1c was 7.87 ± 1.47%. Overall, 1897 of 2001 (95%) patients had an intensified insulin therapy, of which 633 (32%) used insulin pumps (CSII). They injected 0.86 ± 0.47?I.?U. insulin/kg body weight/day and performed 37.6 ± 11.4 blood glucose self-tests/week. The number of patients who participated in medical rehabilitation decreased: In 2016 it was 68% lower than in 2007, the year of the highest number of patients (p < 0.05). Parameters of metabolic control hardly changed. The proportion of patients with CSII increased (p < 0.05). In particular, young children used CSII more frequently (59% in <4 year olds vs 24% in 16–17 year olds, p < 0.05). Changes also occurred in cultural status: The percentage of patients from German families decreased (p < 0.05); the proportion of patients from mixed-cultural families increased (p < 0.05). The number of patients living together with both parents also decreased (p < 0.05 for the tendency); the number of patients living with single parents increased (p < 0.05 for the tendency). In young children, HbA1c values were the lowest. From the beginning of puberty (about 10 years), HbA1c increased (8.5 ± 1.9% in 16–17 year olds). There were no correlations/associations between metabolic control and the incidences of hypoglycemia/ketoacidoses.

Conclusions

There has been a change in medical rehabilitation: The number of patients has decreased, the proportion of patients using CSII has increased, the number of patients living with single parents and the percentage of patients from a culturally mixed families has also increased. Thus, there are new challenges in medical rehabilitation.
  相似文献   
97.
98.
PM10 exposure has been found to have significant effects on a variety of physical conditions. However, whether it acts on psychopathology remains unclear. This study used 8-year data to examine the relationship between PM10 concentration and daily clinic visits of anxiety disorders. All residents of Yunlin County, Taiwan, which is a high river-dust exposure area, were selected as subjects. Data from the Taiwan National Health Insurance Research Database (NHIRD), 2002–2009, were analyzed. Individuals with any ICD code of 300.0 and 300.2 were categorized as with anxiety disorders. PM10 data were based on the Lunbei station (located at Yunlin County) of EPA, Taiwan. Time-series analysis showed that, during the observed 8 years, the number of daily clinic visits for anxiety disorders increased with PM10 levels, and the relationship remained significant after unemployment rate, and the Weighted Price Index of Taiwan Stock Exchange in the same period were controlled for. In particular, we found that there is a linear dose-response effect between daily clinic visits and PM10 levels when PM10 <?300 μg/m3; whereas a dramatically elevated daily clinic visits of anxiety disorders was found when PM10 >?300 μg/m3. Findings from this study highlight that high level of PM10 exposure derived from severe weather or environment condition may affect the occurrence of anxiety disorders. In addition, there seems to have a threshold of PM10 in elevating the risk of anxiety disorders.  相似文献   
99.

Background

The proportion of people in need of care with a migration background and therefore the demand for qualified nursing staff will increase. So far, however, considerations and concepts aiming to improve the care situation (including cultural sensitivity) for people in need of care with a migration background are lacking.

Objective

The following questions are addressed on the basis of care training for relatives with migration background and competence development for health care professionals: What content should the care training/competence development take into account? What are the limits regarding planning and implementation, and what are the suggestions for improvements?

Materials and methods

The development of care training and competence development was based on a needs and resources assessment (in the form of a systematic literature review, an expert workshop, semistructured interviews with relatives with migration background who are providing nursing care). A training manual that has been published includes research results and findings and is applicable to other target groups and settings.

Results and discussion

A transcultural training manual was developed and tested for use in outpatient care. It consists of two parts: training for relatives providing nursing care and competency training for health care specialists. It enables the planning, preparation, and implementation of training courses and includes theoretical background knowledge, practical exercises, and didactic advice. When using the manual, however, the target group should be planned at an early stage and individual needs and resources of course participants should be taken into account.
  相似文献   
100.

Background

Representative surveys collecting weight, height and MUAC are used to estimate the prevalence of acute malnutrition. The results are then used to assess the scale of malnutrition in a population and type of nutritional intervention required. There have been changes in methodology over recent decades; the objective of this study was to determine if these have resulted in higher quality surveys.

Methods

In order to examine the change in reliability of such surveys we have analysed the statistical distributions of the derived anthropometric parameters from 1843 surveys conducted by 19 agencies between 1986 and 2015.

Results

With the introduction of standardised guidelines and software by 2003 and their more general application from 2007 the mean standard deviation, kurtosis and skewness of the parameters used to assess nutritional status have each moved to now approximate the distribution of the WHO standards when the exclusion of outliers from analysis is based upon SMART flagging procedure. Where WHO flags, that only exclude data incompatible with life, are used the quality of anthropometric surveys has improved and the results now approach those seen with SMART flags and the WHO standards distribution. Agencies vary in their uptake and adherence to standard guidelines. Those agencies that fully implement the guidelines achieve the most consistently reliable results.

Conclusions

Standard methods should be universally used to produce reliable data and tests of data quality and SMART type flagging procedures should be applied and reported to ensure that the data are credible and therefore inform appropriate intervention. Use of SMART guidelines has coincided with reliable anthropometric data since 2007.
  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