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   222篇
  免费   11篇
  国内免费   8篇
儿科学   13篇
妇产科学   5篇
基础医学   47篇
口腔科学   12篇
临床医学   13篇
内科学   48篇
皮肤病学   7篇
神经病学   2篇
特种医学   26篇
外科学   26篇
综合类   6篇
预防医学   8篇
药学   13篇
中国医学   2篇
肿瘤学   13篇
  2021年   2篇
  2020年   6篇
  2019年   3篇
  2018年   2篇
  2017年   4篇
  2016年   2篇
  2015年   2篇
  2014年   5篇
  2013年   4篇
  2012年   8篇
  2011年   14篇
  2010年   13篇
  2009年   12篇
  2008年   12篇
  2007年   10篇
  2006年   13篇
  2005年   13篇
  2004年   5篇
  2003年   12篇
  2002年   9篇
  2001年   7篇
  2000年   9篇
  1999年   5篇
  1998年   11篇
  1997年   11篇
  1996年   2篇
  1995年   5篇
  1994年   3篇
  1993年   5篇
  1992年   1篇
  1991年   3篇
  1990年   4篇
  1989年   5篇
  1988年   1篇
  1986年   3篇
  1985年   4篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1975年   1篇
排序方式: 共有241条查询结果,搜索用时 625 毫秒
51.

Objective

In this paper, we describe the main objectives, the study design and the onset of the patient cohort of the German Competence Network for HIV/AIDS (KompNet). Furthermore, we depict sociodemographic and clinical baseline characteristics and an estimation of the coverage and representativity as to the composition of persons living with HIV/AIDS (PLWHA) in Germany.

Methods

The KompNet cohort is an open, retrospective and prospective, multicenter, disease-specific and nationwide cohort study that started gathering data in June 2004. Semi-annually, follow up visits of the patients are documented, covering clinical and sociodemographic data. At enrolment and three years afterwards, an EDTA-sample is taken; a serum-sample is taken at every follow up visit.

Results

As of 14.9.2008, a total of 15,541 patients were enrolled by 44 documenting sites. In September 2007, the cohort size was reduced to 10 outpatient clinics and fifteen private practitioners, covering a total of 9,410 patients. The documentation of these patients comprises 24,117 years of follow up-time since enrolment (mean: 2.6 years), 62,862 person years inclusive data documented retrospectively on course of HIV-infection and combined antiretroviral therapy (cART, mean: 6.7 years). 1,008 patients (10.7%) were lost to follow up and 175 (1.9%) died since enrolment. 84.9% of patients were men. Main risks of transmission were sex between men (MSM: 62.9%), heterosexual contacts (18.4%), intravenous drug use (IVDU: 7.0%) and origin from a high prevalence country (HPL: 5.2%). Mean age was 45 years.

Conclusion

The KompNet cohort covers about a quarter of all patients being under treatment in Germany. The composition of the cohort represents well the most important risks of transmission in Germany. The cohort contains a high proportion of patients being older than 49 years (28.1%). On basis of its comprehensive database and its biomaterials banks, the KompNet cohort serves as an important instrument to monitor and analyse the effects of combined antiretroviral therapy (cART) in Germany, interdigidating basis, clinical and psychosocial research in view to translational research.  相似文献   
52.
Systemic sclerosis results in tissue fibrosis due to the activation of fibroblasts and the ensuing overproduction of the extracellular matrix. We previously reported that the absence of α2-antiplasmin (α2AP) attenuated the process of dermal fibrosis; however, the detailed mechanism of how α2AP affects the progression of fibrosis remained unclear. The goal of the present study was to examine the role of α2AP in fibrotic change. We observed significantly higher levels of α2AP expression in the skin of bleomycin-injected systemic sclerosis model mice in comparison with the levels seen in control mice. We also demonstrated that α2AP induced myofibroblast differentiation, and the absence of α2AP attenuated the induction of myofibroblast differentiation. Moreover, we found that connective tissue growth factor induced the expression of α2AP through both the extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) pathways in fibroblasts. Interestingly, α2AP also induced transforming growth factor-β expression through the same pathways, and the inhibition of ERK1/2 and JNK slowed the progression of bleomycin-induced fibrosis. Our findings suggest that α2AP is associated with the progression of fibrosis, and regulation of α2AP expression by the ERK1/2 and JNK pathways may be an effective antifibrotic therapy for the treatment of systemic sclerosis.Systemic sclerosis (SSc) affects the skin and the internal organs, resulting in tissue fibrosis. Although the disease process involves immunological mechanisms, vascular damage, and activation of fibroblasts, the pathogenesis of SSc remains to be further elucidated. Fibrotic diseases are characterized by excessive scarring due to excessive production, deposition, and contraction of the extracellular matrix (ECM). This process usually occurs over many months and years, and can lead to organ dysfunction or death. Connective tissue growth factor (CTGF) is constitutively overexpressed in fibrotic lesions such as in scleroderma,1 liver,2 renal,3,4 lung,5 and pancreatic fibrosis.5 CTGF acts as a downstream effecter of at least some of the profibrotic effects of transforming growth factor-β (TGF-ß),6 and promotes fibroblast proliferation, myofibroblasts differentiation, matrix production, and granulation tissue formation.7,8Human and murine α2-antiplasmin (α2AP) are serpins (serine protease inhibitors) with a molecular weight of 65 to 70 kd,9 which rapidly inactivate plasmin, resulting in the formation of a stable inactive complex, plasmin-α2AP.10 Tissue fibrosis is generally considered to arise due to a failure of the normal wound healing response to terminate.11 Previous our studies show that α2AP is associated with the wound healing and the fibrosis.12,13 In addition, it has been reported that the level of plasmin-α2AP complex in plasma is elevated in SSc patients.14 These findings suggest that α2AP may be associated with the progression of fibrotic disease, but the physiological roles of α2AP are not precisely understood. We herein report that α2AP plays an important role in the progression of fibrosis.  相似文献   
53.
Aim:  Recent reports have shown that bone marrow cells (BMC) retain the potential to differentiate into hepatocytes. Thus, the BMC have been recognized as an attractive source for liver regenerative medicine. However, it has not been clarified whether BMC transplantation can be used to treat liver damage in vivo . In the present study, we explored whether BMC possess therapeutic potential to treat acute and/or subacute liver failure.
Methods:  Fulminant hepatic failure (FHF) was induced by 70% hepatectomy with ligation of the right lobe pedicle (24% liver mass), followed by transplantation of BMC into the spleen. Dipeptidyl peptidase IV-positive (DPPIV+) BMC were then transplanted into DPPIV-negative (DPPIV-) recipients following hepatic irradiation (HIR) in which 70% of the liver was resected and the remnant liver irradiated.
Results:  There was no benefit of BMC transplantation towards survival in the FHF model. DPPIV+ hepatocytes appeared in the liver tissues of the DPPIV- HIR model rats, but DPPIV+ hepatocytes replaced less than 13% of the recipient liver.
Conclusion:  BMC transplantation may have limitations in the treatment of fulminant or acute liver failure because they do not have sufficient time to develop into functional hepatocytes. Preparative HIR may be beneficial in help to convert the transplanted BMC into host hepatocytes, and provide a survival benefit. Although, However, the precise mechanism warrants further studies.  相似文献   
54.
This study assesses the frequency of lower limb and back pain in children with Guillain-Barré syndrome and reviews the magnetic resonance imaging results of those undergoing spinal imaging. Over an 8-y period, nine children presented with various combinations of severe back pain, leg pains, impairment of gait and bladder dysfunction. Guillain-Barré syndrome was confirmed on clinical examination and peripheral electrophysiology ( n = 8). Magnetic resonance imaging in four patients, following contrast injection, showed enhancement of the cauda equine and, additionally, of the cervical nerve roots in one of the patients. A further patient, who was not scanned with contrast, had abnormal thickening of the lumbar roots. Carbamazepine and steroids were effectively used for analgesia in three cases. All the patients recovered.
Conclusion: Guillain-Barré syndrome should be considered in the differential diagnosis of children presenting with back and/or leg pain. Early diagnosis ensures prompt monitoring for autonomic dysfunction and respiratory compromise.  相似文献   
55.
Our bioartificial liver (BAL) consists of porcine hepatocytes attached to beads and plasma perfused through the system. The function of our BAL lasts for approximately 7 hours. The objective of the present study was to investigate the efficacy of Nafamostat Mesilate (NM), a protease inhibitor and potent complement inhibitor, for improving the performance of the BAL. The experimental groups were divided as follows; the NM group (n=7) where the BAL had porcine hepatocytes with 3.8x10(-4) M, of NM, and the control group where the BAL had no NM. Plasma obtained from patients suffering from hepatic failure was perfused through the BAL for 10 hours. The viability of the porcine hepatocytes and the levels of alanine aminotransferase (ALT) in the human plasma were measured during perfusion. After the 10-hour perfusion, another human hepatic failure plasma was perfused for an additional 1 hour and then the function of the BAL was evaluated. After the 10-hour perfusion, the viability of the hepatocytes in the NM group was 51 +/- 7%, whereas that in the control group was rapidly reduced by 35 +/- 5%. Although the levels of ALT in the human plasma in both groups increased with the perfusion time, those in the NM group were significantly lower than those in the control group (p < 0.05). These results suggest that NM prevented damage to the porcine hepatocytes in human hepatic failure plasma as compared to the control group. In the human hepatic failure plasma before perfusion, the partial thrombin time (PT) and the plasma ammonia (NH3) levels were 19.8 +/- 12% and 288 +/- 102 microg/dl, respectively. Fischer's ratios were 0.98 +/- 0.39. Even after the 10-hour perfusion, the BAL in the NM group significantly improved the levels of PT (38 +/- 10%; p < 0.05), NH3 (214 +/- 34 microg/dl; p < 0.05) and Fischer's ratios (1.4 +/- 0.3; p < 0.05). On the other hand, the BAL in the control group did not show any improvement in those parameters. In conclusion, NM was found to help in maintaining the viability of porcine hepatocytes in human hepatic failure plasma, thereby allowing the porcine hepatocyte-based BAL to function much better.  相似文献   
56.
Poly(tetramethylene oxide) (PTMO)-TiO(2) hybrids were prepared by a sol-gel method from triethoxysilane-functionalized PTMO (Si-PTMO) and tetraisopropyltitanate with weight ratios of 30/70, 40/60 and 50/50 (hybrids PT30, PT40 and PT50, respectively), and subsequently subjected to a hot-water treatment at 95 degrees C for 2 d. All the obtained hybrids were amorphous before the hot-water treatment, and precipitated nanosized anatase after the hot-water treatment. The amount of precipitated anatase increased with decreasing PTMO content. Apatite was not formed on the surfaces of the hybrids in a simulated body fluid before the hot-water treatment, but was formed after the hot-water treatment, and its amount increased with decreasing PTMO content. Hybrid PT40 showed strength and Young's modulus analogous to those of human cancellous bones, and high ductility after the hot-water treatment. This kind of hybrid is expected to be useful as a new type of bone-repairing material.  相似文献   
57.
Glass-ionomer cements, which consist of CaO-Al2O3-SiO2-CaF2 glass powders and a polyalkenoic acid solution, such as polyacrylic acid (PAA), have been widely used in dentistry. They set rapidly without any shrinkage, the lack of temperature increase on reaction, and develop high mechanical strength. Therefore, if bioactive glass-ionomer cements can be obtained, such cements are expected to be useful as cements for fixing orthopaedic implants to the surrounding bone. In the present study, to examine the possibility of obtaining bioactive glass-ionomer cements, the effect of PAA on the apatite formation on bioactive ceramics in a simulated body fluid was investigated. It was revealed that presence of even a small quantity of PAA inhibits the apatite formation in the body environment. It is speculated that when glass-ionomer cements are implanted into the body, PAA can be released from the glass-ionomer cements and inhibits the apatite formation on their surfaces. It is reasonable to suppose that this will occur with any glass-ionomer cement that contains PAA. Therefore, it might be considered difficult to obtain bioactive glass-ionomer cements.  相似文献   
58.
59.
A girl aged 2.5 years with "covert toxocariasis" was treated with low-dose diethylcarbamazine because of supposed noticeable disseminated Toxocara canis infection without ocular or visceral manifestations. There was marked blood and bone marrow eosinophilia, significant increased Toxocara canis antibody (ELISA) and immunoglobulins E, G and M, leucocytosis and an increased sedimentation rate. She had no geophagia, but often sucked small stones, probably contaminated with faeces from puppies. Symptoms were fever, inactivity, weakness, tiredness and loss of appetite. She was followed clinically and with blood samples throughout a period of three years and four months.  相似文献   
60.
OBJECTIVES: To determine the relative cost-effectiveness of the inhaled corticosteroids beclomethasone dipropionate (BDP), budesonide (BUD), and fluticasone propionate (FP), for managing moderate to severe asthma in adults over a one-year time horizon from the perspective of the Ministry of Health (MOH) in Canada.
METHODS: A single-arm meta-analysis of randomized control trials containing at least one of FP, BUD, and BDP was performed in order to derive estimates of effectiveness and tolerance. A decision tree analysis was then used to model the cost-effectiveness analysis. Only direct medical costs were included in the analysis (i.e., inpatient care, emergency visits, physician services, nursing services, drugs, diagnostic tests). The time horizon of the study was 52 weeks, precluding discounting. All costs are presented in 1996 Canadian dollars (CDN$). The cost-effectiveness was the cost per additional symptom-free day ($/SFD).
RESULTS: 69 of 398 articles were included in the metaanalysis. The Monte Carlo base case analysis showed that FP and BUD resulted in an annual cost of $1,383 and $1,147 respectively (p > 0.01). FP produced 216 SFDs while BUD resulted in 214 SFDs, which were not significantly different at p = 0.01 (corrected for multiple comparisons). BDP cost $1,343/year and yielded 213 SFD/year (BDP was excluded from the final analysis, dominated by BUD). With no difference in effectiveness, a cost-minimization analysis showed that BUD was the cost-effective alternative, costing $236 CDN less than the FP strategy.
CONCLUSIONS: Of the inhaled corticosteroids available on the MOH Formulary in Canada, BUD is a costeffective alternative for the treatment of adults with moderate to severe asthma.  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