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   765篇
  免费   49篇
  国内免费   5篇
医药卫生   819篇
  2024年   1篇
  2023年   9篇
  2022年   27篇
  2021年   42篇
  2020年   27篇
  2019年   59篇
  2018年   40篇
  2017年   15篇
  2016年   42篇
  2015年   35篇
  2014年   38篇
  2013年   47篇
  2012年   58篇
  2011年   71篇
  2010年   37篇
  2009年   36篇
  2008年   43篇
  2007年   28篇
  2006年   34篇
  2005年   31篇
  2004年   20篇
  2003年   21篇
  2002年   19篇
  2001年   4篇
  2000年   7篇
  1999年   6篇
  1998年   2篇
  1997年   2篇
  1994年   1篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1984年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1975年   1篇
  1974年   1篇
  1973年   2篇
  1971年   1篇
  1955年   1篇
排序方式: 共有819条查询结果,搜索用时 0 毫秒
1.
Dental management of patients with autoimmune vesiculobullous disorders is complicated because of prominent involvement of oral mucosa, increased risk of oral disease, and difficulty in rendering dental care. Although these diseases are relatively uncommon, dental practitioners should be familiar with the oral sequelae of these conditions and their management. Pemphigus vulgaris, cicatricial pemphigoid, and epidermolysis bullosa represent the most common autoimmune oral vesiculobullous diseases. This case-illustrated review summarizes the pathogenesis, diagnostic features, and natural history of oral vesiculobullous disorders, placing an emphasis on the treatment and prevention of associated oral disease aimed at maintaining a healthy, functional dentition.  相似文献   
2.
BACKGROUND: As costs related to mechanical ventilation increase, clear indicators of patients' readiness to be weaned are needed. Research has not yet yielded a consensus on physiological variables that are consistent correlates of weaning outcomes. Subjective perceptions rarely have been examined for their contribution to successful weaning. OBJECTIVE: To explore the subjective perceptions of dyspnea, fatigue, and self-efficacy and selected physiological variables in patients being weaned from mechanical ventilation. METHODS: Data were collected prospectively on 68 patients being weaned from mechanical ventilation. Subjective perceptions were measured by using 3 visual analog scales; physiological variables were measured by using the Burns Weaning Assessment Program and a patient profile. Weaning outcomes were recorded 24 hours after data collection. RESULTS: Participants were primarily white women and required mechanical ventilation for a mean of less than 4 days. Participants reported mild dyspnea, moderate fatigue, and high weaning self-efficacy. High PaO2, low PaCO2, stable hemodynamic status, adequate cough and swallow reflexes, no metabolic changes, and no abdominal problems were associated with complete weaning (P = .05). Subjective perceptions were associated with physiological variables but not with weaning outcomes. CONCLUSIONS: Multidimensional assessment of both primary and secondary indicators of readiness to be weaned is necessary for timely, efficient weaning from mechanical ventilation. Primary assessments include physiological variables related to gas exchange, hemodynamic status, diaphragmatic expansion, and airway clearance. Secondary assessments include perceptions related to key physiological variables. Additional research is needed to determine the predictive value of physiological variables and perceptions of dyspnea, fatigue, and self-efficacy.  相似文献   
3.
Inflammatory infiltrates can modify (lipo)proteins via hypochlorous acid/hypochlorite (HOCl/OCl(-)) an oxidant formed by the myeloperoxidase-H(2)O(2)-halide system. These oxidatively modified proteins emerge in tubuli in some proteinuric and interstitial diseases. Human proximal tubular cells (HK-2) were used to confirm the hypothesis of detrimental and differential impact of HOCl-modified low density lipoprotein (HOCl-LDL), an in vivo occurring lipoprotein modification exerting proatherogenic and proinflammatory capacity. HOCl-LDL showed dose-dependent antiproliferative effects in HK-2 cells. Small dedicated cDNA macroarrays were used to identify differentially regulated genes. A rapid increase in the expression of genes involved in reactive oxygen species metabolism and cell stress, eg, heme oxygenase-1, thioredoxin reductase, cytochrome b5 reductase, Gadd 153, amino acid transporter E16, and HSP70 was found after HOCl-LDL treatment of HK-2 cells. In parallel, genes involved in tissue remodeling and inflammation eg, CTGF, VCAM-1, IL-1beta, MMP7, and VEGF were up-regulated. Quantitative RT-PCR verified differential expression of a subset of these genes in microdissected tubulointerstitia from patients with acute tubular damage, progressive proteinuric renal disease, and membranous glomerulonephritis (with declining renal function), but not in stable patients with proteinuria caused by minimal change disease. The demonstration of selective up-regulation of a subgroup of genes if proteinuria is accompanied by the presence of HOCl-modified (lipo)proteins support the potential pathophysiological role of the myeloperoxidase-H(2)O(2)-halide system and HOCl-LDL in renal disease.  相似文献   
4.
Endometrial receptivity and implantation are important topics in reproductive sciences. No evidence was found to support sperm involvement in endometrial receptivity and its associated factors. This study aimed to explore the effect of the normal human spermatozoa–endometrium cell interaction in regulating genes in the endometrial receptivity pathway. Semen samples were collected from a healthy and fertile man; then, they were incubated with endometrial cells for 24 hr and considered as the sperm group. A group was cultured without spermatozoa and considered as a control group. About 24 hr later, cells were collected from the bottom of the culture dish. The expressions of the VEGF, FGF2, HBEGF, LIFR, EGF, LIF, MUC1, HOXA10, CSF and PGR genes were evaluated in the two groups. Statistical analysis was performed using an independent sample test. Compared with the control group, in the sperm group, the mRNA levels of PGR (p = .0451), VEGF (p = .0101), HBEGF (p = .0163), EFG (p = .0339), FGF2 (p = .012), LIF (p = .0324), LIFR (p = .0321) and HOXA10 (p = .0098) were significantly upregulated. The results showed that there is a need for the interaction between spermatozoa and endometrium for implantation and can be used for preparing uterine in in vitro fertilisation cycles.  相似文献   
5.
We demonstrate here that motoneurons and nigral dopaminergic neurons in the brainstem of the adult rat, with the exception of motoneurons innervating ocular muscles, display high levels of both MHC class I heavy chain and beta2-microglobulin mRNAs. These neurons also display interferon-gamma receptor mRNA. We find it striking that these particular neurons are those which are vulnerable to neurodegeneration in diseases such as Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS).  相似文献   
6.
7.
8.
Genotoxic impurities (GTIs) in pharmaceuticals at trace levels are of increasing concerns to both pharmaceutical industries and regulatory agencies due to their potentials for human carcinogenesis. Determination of these impurities at ppm levels requires highly sensitive analytical methodologies, which poses tremendous challenges on analytical communities in pharmaceutical R&D. Practical guidance with respect to the analytical determination of diverse classes of GTIs is currently lacking in the literature. This article provides an industrial perspective with regard to the analysis of various structural classes of GTIs that are commonly encountered during chemical development. The recent literatures will be reviewed, and several practical approaches for enhancing analyte detectability developed in recent years will be highlighted. As such, this article is organized into the following main sections: (1) trace analysis toolbox including sample introduction, separation, and detection techniques, as well as several ‘general’ approaches for enhancing detectability; (2) method development: chemical structure and property-based approaches; (3) method validation considerations; and (4) testing and control strategies in process chemistry. The general approaches for enhancing detection sensitivity to be discussed include chemical derivatization, ‘matrix deactivation’, and ‘coordination ion spray-mass spectrometry’. Leveraging the use of these general approaches in method development greatly facilitates the analysis of poorly detectable or unstable/reactive GTIs. It is the authors’ intent to provide a contemporary perspective on method development and validation that can guide analytical scientists in the pharmaceutical industries.  相似文献   
9.
Abstract. Mälarstig A, Silveira A, Wågsäter D, Öhrvik J, Bäcklund A, Samnegård A, Khademi M, Hellenius M‐L, Leander K, Olsson T, Uhlén M, de Faire U, Eriksson P, Hamsten A (Karolinska University Hospital; Institute of Environmental Medicine, Karolinska Institutet, Stockholm; KTH‐Royal Institute of Technology, Stockholm, Sweden). Plasma CD93 concentration is a potential novel biomarker for coronary artery disease. J Intern Med 2011; 270 : 229–236. Objectives. A common nonsynonymous single nucleotide polymorphism (SNP) in the CD93 gene (rs3746731, Pro541Ser) has been associated with risk of coronary artery disease (CAD). CD93 is a transmembrane glycoprotein, which is detectable in soluble form in human plasma. We investigated whether the concentration of soluble CD93 in plasma is related to risk of myocardial infarction (MI) and CAD, using a case–control study of premature MI (n = 764) and a nested case–control analysis of a longitudinal cohort study of 60‐year‐old subjects (analysis comprising 844 of 4232 subjects enrolled at baseline). In addition, SNPs in the CD93 gene were studied in relation to plasma CD93 concentration and CD93 mRNA expression. Methods and Results. A sensitive and specific enzyme‐linked immunosorbent assay was established for determination of the plasma CD93 concentration. Subjects were divided into three groups according to tertiles of the distribution of CD93 concentration. Lower odds ratios for risk of MI and incidence of CAD were observed in the middle CD93 tertile (142–173 μg L?1): odds ratio (95% confidence interval), 0.69 (0.49–0.97) and 0.61 (0.40–0.94), respectively. These associations were independent of traditional CAD risk factors. The minor allele of a SNP in the 3′ untranslated region of CD93 (rs2749812) was associated with increased plasma CD93 concentrations (P = 0.03) and increased CD93 mRNA expression levels (P = 0.02). Conclusion. The results of the present study suggest that the concentration of soluble CD93 in plasma is a potential novel biomarker for CAD, including MI.  相似文献   
10.
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