首页 | 官方网站   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   1945篇
  免费   96篇
  国内免费   4篇
医药卫生   2045篇
  2023年   12篇
  2022年   15篇
  2021年   67篇
  2020年   36篇
  2019年   62篇
  2018年   70篇
  2017年   40篇
  2016年   44篇
  2015年   71篇
  2014年   67篇
  2013年   111篇
  2012年   146篇
  2011年   138篇
  2010年   83篇
  2009年   65篇
  2008年   131篇
  2007年   90篇
  2006年   93篇
  2005年   111篇
  2004年   81篇
  2003年   92篇
  2002年   59篇
  2001年   50篇
  2000年   55篇
  1999年   50篇
  1998年   13篇
  1997年   19篇
  1996年   12篇
  1995年   7篇
  1994年   4篇
  1993年   6篇
  1992年   27篇
  1991年   16篇
  1990年   13篇
  1989年   12篇
  1988年   11篇
  1987年   13篇
  1986年   8篇
  1985年   8篇
  1984年   3篇
  1983年   3篇
  1980年   4篇
  1978年   2篇
  1977年   3篇
  1976年   4篇
  1974年   8篇
  1973年   3篇
  1969年   2篇
  1968年   1篇
  1967年   1篇
排序方式: 共有2045条查询结果,搜索用时 46 毫秒
1.
2.

Objective

To analyse and understand vaccination hesitancy discourses, particularly those of people who have decided not to vaccinate their sons and daughters.

Methods

Qualitative study of five individual interviews and two focus groups with people who chose not to vaccinate their children in the province of Granada (Spain).

Results

Mothers and fathers manifest a system of health beliefs different to the biomedical paradigm. From an ethical point of view, they justify their position based on the right to autonomy and responsibility for their decisions. Alleged specific reasons: they doubt administration of several vaccines simultaneously at an early age in a systematic way and without individualising each case; they fear adverse effects and do not understand the variations of the vaccination schedule.

Conclusions

These vaccination hesitancy discourses respond to the individual vs collective conflict; parents defend their right to bring up their children without any interference from the state and focus their responsibility on the individual welfare of their sons and daughters, regardless of the consequences that their actions might have on the collective. In their management of risks, they consider those derived from vaccination more relevant than the individual or collective consequences of not doing so. The vaccines generating most doubts are the more controversial ones within the scientific world. Transparency in communication of adverse effects; authorities respect for other health/disease concepts; banishment of the term “anti-vaccines” from the media and scientific vocabulary, and developing spaces for dialogue are bridges to be built.  相似文献   
3.
We have analysed B chromosome frequency for three consecutive years, B transmission rate at population and individual levels, clutch size, egg fertility and embryo–adult viability in a natural population of the grasshopper Eyprepocnemis plorans containing two different B chromosome variants, i.e. B2 and B24, the second being derived from the first and having replaced it in nearby populations. From 2002 to 2003 the relative frequency of both variants changed, although the differences did not reach significance. A mother–offspring analysis showed no significant effect of any of the two B variants on clutch size, egg fertility or embryo–adult viability, but B24 was more efficiently transmitted than B2 through males from the 2002 season, which explains the observed frequency change. Controlled crosses, at individual level, showed significant drive through some females for B24 but not for B2, suggesting that this difference in transmission rate might also be important for the substitution process. The analysis of relative fitness for B2 and B24 carriers for all fitness components, as a whole, showed a significantly better performance of B24-carrying individuals, suggesting that the cumulative effect of these slight differences might contribute to the replacement of B2 by B24. Electronic Supplementary Material Supplementary material is available for this article at .  相似文献   
4.
5.
6.
With the objective of finding a simpler and more sensitive method than conventional radioimmunoassay testing to detect HBsAg, we have modified the sample volume and first incubation procedure of the Ausria IIA method. There was an up to 9-fold increase in sensitivity without loss of specificity, in different assays, when the first incubation was carried out with a serum sample of 1 ml that was rotatively agitated for 22 h at room temperature. Additionally, 71 samples from which conventional testing had isolated hepatitis B core antibodies were tested with the modified rotative agitation technique and 9 of these specimens (12.67%) were positive for HBsAg. Routine employment of the rotative agitation radioimmunoassay technique to screen HBsAg by blood banks, to detect potential infectious donations that escape conventional testing, could be an effective as well as low-cost procedure to prevent post-transfusion hepatitis B.  相似文献   
7.
Morganella morganii, a gram-negative bacterium, usually infects older patients with urinary catheters, but does not commonly affect pregnant women. In this report we present a case of chorioamnionitis caused by Morganella morganii. The case was complicated by a life-threatening Adult Respiratory Distress Syndrome.  相似文献   
8.
9.
This report deals with the relationships between glucose (G) and insulin on the tubular transport of phosphate (P) in chronically diabetic rats with high plasma levels of parathyroid hormone (PTH). Alloxan-induced diabetes leads to phosphorus depletion of the soft tissues. This phenomenon appears associated with weight loss and negative P balances caused by the increased urinary P excretion. Administration of 2 IU of insulin/100 g body weight (bw) to diabetic rats normalized their P balance and body weight. The effect of parathyroid function on the P metabolism of diabetic rats was investigated with balance experiments. Diabetic rats, intact or thyroparathyroidectomized (TPTX), have a greater urinary excretion of P than their controls. However, in control rats, the ratio intact:TPTX for urinary P is 1.0:0.76, showing the antiphosphaturic effect of parathyroid ablation. For diabetic animals, on the other hand, the ratio is 1.0:1.44. The simultaneous deficit of insulin and PTH thus quadruples the urinary P loss, instead of compensating for each other. The contribution of insulin deficit and hyperglycemia to the defect in tubular reabsorption (TRP) was investigated with clearance experiments (done on anesthetized, perfused rats). Five experimental groups were used: Controls (C), diabetics (D), controls+glucose (C+G), diabetics+insulin (D+I) and diabetics+insulin+glucose (D+I+G). All experimental groups showed a linear relationship between the TRP of P and G. The regression equation for C is significantly different (F=40.1, P<0.001) from that of D animals. The slope value measure the number of μmoles of P per μmol of G reabsorbed. For C and D rats, the ratio P:G approximates 1:4 and 1:20, respectively. The increase in P:G ratios represents the competition between both substrates for tubular resorption. Glycemias up to 11 mM (C and D+I) exist concurrent with the P:G ratio 1:4. Glycemias above 25 mM (D, C+G and D+I+G) produce a P:G ratio of 1:20. Fractional excretion of P (FEP) increased significantly in untreated, chronically diabetic rats (0.47± 0.12 vs controls=0.05±0.01, P<0.001). After a single intramuscular injection of insulin, the FEP decreased as a function of insulin levels. To normalize the FEP of diabetic rats in short-term experiments, insulin had to be administered in doses that produce plasma insulin levels 25 times greater than normal. The general information afforded by the present experiments shows that in untreated, chronically diabetic rats, insulin deficit plays an indirect role. The absence of PTH enhances the effect of hyperglycemia. The latter and the concurrent tubular overload of glucose are the cause of hyperphosphaturia in these animals. Received: 10 September 1996 / Accepted in revised form: 18 April 1997  相似文献   
10.
Cerebral small vessel disease (CSVD) is the most important cause of vascular cognitive impairment (VCI). Most CSVD cases are sporadic but familial monogenic forms of the disorder have also been described. Despite the variants identified, many CSVD cases remain unexplained genetically. We used whole-exome sequencing in an attempt to identify novel gene variants underlying CSVD. A cohort of 35 Finnish patients with suspected CSVD was analyzed. Patients were screened negative for the most common variants affecting function in NOTCH3 in Finland (p.Arg133Cys and p.Arg182Cys). Whole-exome sequencing was performed to search for a genetic cause of CSVD. Our study resulted in the detection of possibly pathogenic variants or variants of unknown significance in genes known to associate with CSVD in six patients, accounting for 17% of cases. Those genes included NOTCH3, HTRA1, COL4A1, and COL4A2. We also identified variants with predicted pathogenic effect in genes associated with other neurological or stroke-related conditions in seven patients, accounting for 20% of cases. This study supports pathogenic roles of variants in COL4A1, COL4A2, and HTRA1 in CSVD and VCI. Our results also suggest that vascular pathogenic mechanisms are linked to neurodegenerative conditions and provide novel insights into the molecular basis of VCI.Subject terms: Stroke, Sequencing, Genetics research, Dementia  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-23

京公网安备 11010802026262号