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   545篇
  免费   70篇
  国内免费   1篇
医药卫生   616篇
  2023年   5篇
  2022年   5篇
  2021年   9篇
  2020年   9篇
  2019年   15篇
  2018年   12篇
  2017年   15篇
  2016年   13篇
  2015年   19篇
  2014年   18篇
  2013年   39篇
  2012年   43篇
  2011年   40篇
  2010年   19篇
  2009年   14篇
  2008年   39篇
  2007年   37篇
  2006年   25篇
  2005年   21篇
  2004年   33篇
  2003年   21篇
  2002年   20篇
  2001年   14篇
  2000年   8篇
  1999年   12篇
  1998年   2篇
  1997年   9篇
  1996年   2篇
  1995年   2篇
  1994年   3篇
  1993年   6篇
  1992年   10篇
  1991年   13篇
  1990年   13篇
  1989年   10篇
  1988年   5篇
  1987年   6篇
  1986年   4篇
  1985年   2篇
  1983年   2篇
  1981年   4篇
  1978年   3篇
  1976年   2篇
  1975年   1篇
  1974年   2篇
  1970年   1篇
  1969年   3篇
  1968年   1篇
  1965年   1篇
  1939年   1篇
排序方式: 共有616条查询结果,搜索用时 15 毫秒
51.
Hepatitis C virus (HCV) infection is the main cause of liver disease after renal transplantation. Most patients have seroconverted on dialysis to positive RNA. The viral load increases during immunosuppressive therapy. The risk of developing chronic liver disease is related to the histopathologic findings, duration and severity of the disease, immunosuppression, and transplantation time. Hepatitis C virus infection can predict onset, of proteinuria and diabetes. We studied 868 patients who received renal transplants between (1987 and 2006), of whom 18.7% were seropositive for HCV. We observed a higher rate of HCV-seropositive patients related to the duration of hemodialysis therapy. Of the HCV seropositive patients, 77% had received renal allografts before 1998. There was no difference between the sexes; however, the HCV positive patients were younger. Polymerase chain reaction tests results were positive in 91.6% of the patients with HCV antibodies. The prevalence of diabetes was greater among HCV positive patients, as was as the persistence of proteinuria. Cryoglobulins were positive in 30.8%. The incidence of acute rejection episodes in the first year was similar between groups. Of the HCV-positive patients, 80.2% were treated with cyclosporine, most patients continued this therapy throughout the study. We observed no significant difference in mortality end graft survival rate between the two groups. However, renal function differed significantly at some points during the evolution of the clinical course. Renal transplantation is still the best treatment option in patients with chronic renal disease.  相似文献   
52.
The aim of this study was to evaluate the minimal biofilm eradication concentration (MBEC) of sodium hypochlorite (NaOCl), chlorhexidine (CHX), EDTA, and citric and phosphoric acids after 1, 5, and 10 minutes of exposure to biofilms of Enterococcus faecalis. The biofilms grew in the MBEC high-throughput device for 24 hours at 37°C and were exposed to 10 serial two-fold dilutions of each irrigating solution. The viable cell counts were log10 transformed, and a concentration of an irrigant was considered to eradicate the biofilms when it produced a reduction of ≥ 5 logarithmic units. NaOCl was the most effective agent, capable of eradicating the biofilms after 1 minute at a concentration of 0.00625%. CHX eradicated biofilm after 5 minutes at 2%. EDTA and citric and phosphoric acid solutions were not effective against the biofilms at any concentration or time tested.  相似文献   
53.
The purpose of this clinical study is to analyse the effectiveness of a sealant. Rubber dam and cotton roll methods of isolation where compared with respect to the effect of isolation method on retreatment and protection from caries during 12 months. We study the cost effectiveness ratio for both methods of isolation. The results could not be substantiated any differences between two methods.  相似文献   
54.
Adult acquired inferior calcaneal heel pain is a common pathology seen in a foot and ankle practice. A literature review and expert panel discussion of the most common findings and treatment options are presented. Various diagnostic and treatment modalities are available to the practitioner. It is prudent to combine appropriate history and physical examination findings with patient-specific treatment modalities for optimum success. We present the most common diagnostic tools and treatment options, followed by a discussion of the appropriateness of each based on the published data and experience of the expert panel.  相似文献   
55.
Objective To evaluate the effects of post-pyloric enteral nutrition (EN) on hepato-splanchnic and systemic hemodynamics, metabolism and gastric mucosal energy balance in septic patients.Design Prospective clinical study.Setting Medical intensive care unit (ICU) in a university hospital.Patients Ten hemodynamically stable, mechanically ventilated patients with severe sepsis. Eight patients required norepinephrine.Intervention Low dose post-pyloric EN (Survimed, 40 ml bolus, 40 ml h–1 continuously).Measurements and results Three data sets: F1 = baseline fasting, EN120 = after 120 min of EN, F2=120 min after EN cessation. In addition to global hemodynamics and gastric mucosal PCO2, we measured hepato-splanchnic blood flow (HSBF) using continuous primed indocyanine green dye infusion with hepatic venous sampling. The mean arterial pressure remained unchanged. During EN systemic vascular resistance decreased (p<0.05), while cardiac index increased (p<0.001). Simultaneously, HSBF increased during EN and decreased again at F2 (1.54 [0.88; 1.66] l min–1 m–2 at F1; 1.72 [1.18; 1.83] l min–1 m–2 at EN and 1.38 [0.91; 1.63] l min–1 m–2 at F2, p<0.001). Hepatic venous acid base status, lactate/pyruvate ratio and splanchnic lactate balance remained unchanged. There was also no change in splanchnic oxygen extraction ratio or in gastric mucosal to arterial PCO2 difference.Conclusion The initiation of low dose post-pyloric EN in medical ICU patients with severe sepsis led to the parallel increase of systemic and hepato-splanchnic blood flow. Hepato-splanchnic energy metabolism, oxygen kinetics and gastric mucosal energy balance did not deteriorate during EN, suggesting that EN during sepsis may not be harmful even in patients requiring norepinephrine.Electronic Supplementary Material Supplementary Material is available in the online version of this article at Presented in part at 15th Annual ESICM congress, Geneva, October 2001  相似文献   
56.
Antibiotic susceptibility testing of two isolates of the Q-fever agent, Coxiella burnetii, was performed with recently and persistently infected L929 fibroblast cells. The two genetically distinct isolates, Nine Mile and Priscilla, are implicated in two different clinical disease syndromes, acute and chronic Q fever, respectively. We compared the efficacies of rifampin, doxycycline, and five 4-quinolone compounds (ciprofloxacin, difloxacin, ofloxacin, norfloxacin, and pefloxacin) in reducing persistent C. burnetii infection of L929 fibroblasts. In persistently infected cells, the Priscilla isolate was less susceptible to all antibiotics tested when compared with the Nine Mile isolate. The most effective antibiotics against the Priscilla isolate were ofloxacin, pefloxacin, and ciprofloxacin (50% inhibitory concentrations of 0.5, 2.2, and 2.5 micrograms/ml, respectively). In persistently infected cells, the Nine Mile isolate was highly susceptible to all antibiotics tested except doxycycline. In contrast, the Priscilla and Nine Mile isolates in recently infected cells were somewhat susceptible to doxycycline; the Priscilla isolate was significantly more susceptible to ofloxacin and rifampin in recently infected host cells than in persistently infected cells. Persistently infected L929 cells were also treated with antibiotic combinations. Although ciprofloxacin and doxycycline had no synergistic effect on the Priscilla isolate, ciprofloxacin and rifampin acted synergistically. Collectively, these in vitro results are in accord with the fact that chronic Q fever in humans is generally not successfully managed with antibiotics. They also indicate that early diagnosis may be essential and that combination antibiotic therapy that includes quinolones may be effective in treating chronic Q fever.  相似文献   
57.
Biological immunomodulators are routinely evaluated as a natural source of molecules with profound effects on the immune system. They belong to a group of physiologically active compounds, collectively termed biological response modifiers. Most of the studies were focused on immune system stimulation. Recently, they have become the focus of studies seeking molecules that are able to overcome negative effects of various immunotoxins. This paper concentrates on the effects of a glucan/resveratrol/vitamin C combination on immunosuppressive effects of mercury and perfluorinated hydrocarbons. Effects described in this review have strong clinical potential, as environmental contaminants have adverse effects on all aspects of the immune system and represent a serious threat to the health of both humans and animals.  相似文献   
58.
59.
Blastocyst implantation is a critical stage in the establishment of pregnancy. Leukemia inhibitory factor (LIF) is essential for mouse blastocyst implantation and also plays a role in human pregnancy. We examined the effect of a potent LIF antagonist (LA) on mouse implantation. In mice, LIF expression peaks on day 3.5 of pregnancy (D3.5) (D0.5 = day of mating plug detection) in the uterine glandular epithelium. LA (7 mg/kg per day) administered from D2.5 to D4.5 via four hourly i.p. injections plus continuous administration via miniosmotic pump resulted in complete implantation failure. To improve its pharmacokinetic properties, we conjugated LA to polyethylene glycol (PEG), achieving a significant increase in serum levels. PEGylated LA (PEGLA) (37.5 mg/kg per day) administered via three i.p. injections between D2.5 and D3.5 also resulted in complete implantation failure. PEGLA immunolocalized to the uterine luminal epithelium at the time of blastocyst implantation. Both LA and PEGLA reduced phosphorylation of the downstream signaling molecule STAT3 in luminal epithelial cells on D3.5. The effects of PEGLA were found to be endometrial, with no embryo-lethal effects observed. These data demonstrate that administration of a PEGylated LIF antagonist is an effective method of targeting LIF signaling in the endometrium and a promising novel approach in the development of nonhormonal contraceptives for women.  相似文献   
60.
OBJECTIVE: To investigate if the persistence of systemic features is longer in Hispanic children with systemic juvenile idiopathic arthritis (S-JIA) than in non-Hispanic children with S-JIA and to determine early predictors of systemic and articular disease. METHODS: We performed a multi-center retrospective chart review of patients followed in six pediatric rheumatology centers with onset of S-JIA from 1974 to 2004. Patients were included in the study if they had been followed for > or = 1 year after disease onset. Information collected included demographic, clinical, laboratory and treatment data. Systemic features included fever, rash, lymphadenopathy, hepatosplenomegaly, pericarditis, and pleuritis. RESULTS: Of the 159 S-JIA patients screened, 120 (75%) met our inclusion criteria. There were 65 boys and 55 girls. The mean follow-up period for Hispanic patients was 5.7 years (SD 4.0) and for non-Hispanic patients was 8.6 years (SD 7.2). There was no significant difference in the presence of systemic features between Hispanic and non-Hispanic patients at 0.5, 1, 2, 4, 6, 8, and 10 years of follow-up. Polyarthritis at the 6-month visit was predictive of systemic features (OR 9.7, 95% CI 1.16-81.35, p = 0.036) and polyarthritis (OR 5.6, 95% CI 1.42-21.8, p = 0.014) at last follow-up. CONCLUSION: In children with S-JIA, Hispanics did not demonstrate longer persistence of systemic features than non-Hispanics. Polyarthritis at 6 months strongly predicted the development of persistent systemic features and chronic polyarticular disease.  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