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   912篇
  免费   75篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   45篇
妇产科学   26篇
基础医学   103篇
口腔科学   30篇
临床医学   76篇
内科学   156篇
皮肤病学   22篇
神经病学   53篇
特种医学   11篇
外国民族医学   1篇
外科学   103篇
综合类   16篇
预防医学   123篇
眼科学   64篇
药学   78篇
中国医学   21篇
肿瘤学   64篇
  2024年   4篇
  2023年   17篇
  2022年   20篇
  2021年   46篇
  2020年   25篇
  2019年   23篇
  2018年   37篇
  2017年   36篇
  2016年   29篇
  2015年   43篇
  2014年   52篇
  2013年   70篇
  2012年   68篇
  2011年   68篇
  2010年   52篇
  2009年   30篇
  2008年   58篇
  2007年   48篇
  2006年   52篇
  2005年   45篇
  2004年   47篇
  2003年   37篇
  2002年   31篇
  2001年   6篇
  2000年   3篇
  1999年   6篇
  1998年   10篇
  1997年   3篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1991年   1篇
  1990年   4篇
  1989年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1978年   1篇
  1974年   1篇
  1973年   1篇
  1970年   1篇
排序方式: 共有993条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND: Staphylococcus aureus-associated peritonitis and catheter exit-site infections (ESIs) are important causes of hospitalization and catheter loss in patients undergoing chronic peritoneal dialysis. Intranasal and topical use of mupirocin has been found to be an effective strategy in decreasing S. aureus-related infectious complications in persons who are carriers of S. aureus; however, there is no consensus regarding the prophylactic use of mupirocin irrespective of carrier status. We aimed to determine the potential effectiveness of application of mupirocin cream at the catheter exit site in preventing ESI and peritonitis irrespective of carrier status in a tropical country such as India. METHODS: This prospective historically controlled study was done in a total of 40 patients. From August 2003, all patients, incident and prevalent, were instructed to apply 2% mupirocin cream daily to the exit site instead of the older practice of povidone-iodine and gauze dressing. Patients were not screened to determine whether they were S. aureus carriers. The infection-related data for 1 year, until July 2004, were compared with the historical control, which was infection-related data for the year preceding the year of mupirocin application. RESULTS: Mean age of the study population was 62 years, with 61.8% being male and 64.3% being diabetic. Local application of mupirocin led to a significant reduction in the incidence density per patient-month of both ESI and peritonitis compared to controls (0.15 vs 0.37 and 0.37 vs 0.67, p = 0.01 for both). This amounted to a relative reduction of 60.5% and 55% respectively. ESI and peritonitis due to S. aureus were also significantly lower in the study group compared to controls (incidence density per patient-month 0.05 vs 0.13 and zero vs 0.17 respectively, p < 0.01 for both). There occurred no catheter removal due to infection-related complications during the study period compared to two during the control period. None of the patients reported a mupirocin-related adverse effect. CONCLUSIONS: Daily application of mupirocin at the exit site is a well-tolerated and effective strategy in reducing the incidence of ESI and peritonitis in a tropical country such as India. It can thus significantly reduce morbidity, catheter loss, and transfer to hemodialysis in peritoneal dialysis patients.  相似文献   
3.
A 32-year-old male presented with progressive weakness and numbness of both upper limbs of one-month duration. The patient had weakness and wasting of small muscles of both hands with weak grip. Sensory system revealed graded sensory loss to pain, temperature and touch in C5 to T1 distribution and vibration and joint position sense from C5 to C8 in the both upper limbs. There was areflexia in the upper limbs while there was no motor or sensory deficit in the lower limbs. The cortical potential on stimulation of posterior tibial nerve was prolonged on both sides. On MR imaging of the cervical spine there was iso to low intense lesion which was hyperintense on T2-weighted imaging along the dorsal aspect of the cord extending from C2 to C6 level. The axial images showed involvement of the posterior column. The serum vitamin B12 level was found to be low. The patient responded to parenteral cyanocobalamine therapy and the radiological lesion subsequently resolved.  相似文献   
4.
Microinjections of Leu-enkephalin into the dorsal vagal complex induced hypotension and bradycardia. Both naloxone, given at a dose conferring selectivity for μ receptors, and the S antagonist ICI 154,129 prevented the cardiovascular effects of Leu-enkephalin. Naloxone was also found to decrease the gain of the baroreflex. These results suggest that Leu-enkephalin is involved in cardiovascular regulation through activation of δ-, and possibly μ-, opioid receptors in the dorsal vagal complex.  相似文献   
5.
Lyme disease, a chronic multisystemic disorder that can affect the skin, heart, joints, and nervous system is caused by Borrelia burgdorferi sensu lato. Lyme disease spirochetes were previously shown to bind glycosaminoglycans (GAGs). In the current study, the GAG-binding properties of eight Lyme disease strains were determined. Binding by two high-passage HB19 derivatives to Vero cells could not be inhibited by enzymatic removal of GAGs or by the addition of exogenous GAG. The other six strains, which included a different high-passage HB19 derivative (HB19 clone 1), were shown to recognize both heparan sulfate and dermatan sulfate in cell-binding assays, but the relative efficiency of binding to these two GAGs varied among the strains. Strains N40, CA20-2A, and PBi bound predominantly to heparan sulfate, PBo bound both heparan sulfate and dermatan sulfate roughly equally, and VS461 and HB19 clone 1 recognized primarily dermatan sulfate. Cell binding by strain HB19 clone 1 was inhibited better by exogenous dermatan sulfate than by heparin, whereas heparin was the better inhibitor of binding by strain N40. The GAG-binding preference of a Lyme disease strain was reflected in its cell-type-specific binding. Strains that recognized predominantly heparan sulfate bound efficiently to both C6 glioma cells and EA-Hy926 cells, whereas strains that recognized predominantly dermatan sulfate bound well only to the glial cells. The effect of lyase treatment of these cells on bacterial binding was consistent with the model that cell-type-specific binding was a reflection of the GAG-binding preference. We conclude that the GAG-binding preference varies with the strain of Lyme disease spirochete and that this variation influences cell-type-specific binding in vitro.  相似文献   
6.
IntroductionSemen induces mucosal changes in the female reproductive tract to improve pregnancy outcomes. Since semen‐induced alterations are likely short‐lived and genital inflammation is linked to HIV acquisition in women, we investigated the contribution of recent semen exposure on biomarkers of genital inflammation in women at high HIV risk and the persistence of these associations.MethodsWe assessed stored genital specimens from 152 HIV‐negative KwaZulu‐Natal women who participated in the CAPRISA 008 trial between November 2012 and October 2014. During the two‐year study period, 651 vaginal specimens were collected biannually (mean five samples per woman). Cervicovaginal lavage (CVL) was screened for prostate‐specific antigen (PSA) by ELISA, whereas Y‐chromosome DNA (YcDNA) detection and quantification were conducted by RT‐PCR, representing semen exposure within 48 hours (PSA+YcDNA+) and semen exposure within three to fifteen days (PSA−YcDNA+). Soluble protein concentrations were measured in CVLs by multiplexed ELISA. T‐cell frequencies were assessed in cytobrushes by flow‐cytometry, and vulvovaginal swabs were used to detect common vaginal microbes by PCR. Linear mixed models adjusting for factors associated with genital inflammation and HIV risk were used to assess the impact of semen exposure on biomarkers of inflammation over multiple visits.ResultsHere, 19% (125/651) of CVLs were PSA+YcDNA+, 14% (93/651) were PSA−YcDNA+ and 67% (433/651) were PSA−YcDNA−. Semen exposure was associated with how often women saw their partners, the frequency of vaginal sex in the past month, HSV‐2 antibody detection, current gonorrhoea infection and Nugent Score. Both PSA detection (PSA+YcDNA+) and higher cervicovaginal YcDNA concentrations predicted increases in several cytokines, barrier‐related proteins (MMP‐2, TIMP‐1 and TIMP‐4) and activated CD4+CCR5+HLA‐DR+ T cells (β = 0.050; CI 0.001 to 0.098; p = 0.046) and CD4+HLA‐DR+ T cells (β = 0.177; CI 0.016 to 0.339; p = 0.032) respectively. PSA detection was specifically associated with raised pro‐inflammatory cytokines (including IL‐6, TNF‐α, IP‐10 and RANTES), and with the detection of BVAB2 (OR = 1.755; CI 1.116 to 2.760; p = 0.015), P. bivia (OR = 1.886; CI 1.102 to 3.228; p = 0.021) and Gardnerella vaginalis (OR = 1.815; CI 1.093 to 3.015; p = 0.021).ConclusionsMore recent semen exposure was associated with raised levels of inflammatory biomarkers and the detection of BV‐associated microbes, which declined by three to fifteen days of post‐exposure. Although transient, semen‐induced alterations may have implications for HIV susceptibility in women.  相似文献   
7.
8.
Living with a chronic or mental health condition can be challenging and requires considerable adjustment. As ways of coping are culturally influenced, it is important to understand how minority ethnic populations cope, to inform appropriate services. This review aimed to explore the coping strategies used by UK residents from an African Caribbean or Irish background between 1960 and 2020. A systematic literature search on strategies used to cope with chronic health conditions in both populations living in the United Kingdom identified 26 relevant studies. Data were extracted, quality of papers was appraised and critical interpretive synthesis was applied. Two major foci of the studies were coping strategies and barriers to coping. The main coping strategies were denial/scepticism, self-management, spirituality and religion. Within each population, there was variation in ways of coping. The review highlights the complex role of religion in influencing coping strategies. It demonstrates how personal and minority ethnic populations’ experiences of service use are connected with stigma, fear and mistrust, which also act as barriers to seeking help and to coping. Coping with a chronic or mental health condition in the Irish and African Caribbean populations is under-researched. Stigma, fear and mistrust in services act as key barriers to help-seeking and religion is a prominent coping strategy. However, few detailed examples were given on how it was used to assist individuals when managing a chronic or mental health condition. Also due to a lack of research, firm conclusions cannot be drawn for the Irish population.  相似文献   
9.
PURPOSE: In this multicenter, randomized, placebo-controlled clinical trial, we studied whether warfarin 1 mg daily reduces the incidence of symptomatic central venous catheter (CVC) -associated thrombosis in patients with cancer. PATIENTS AND METHODS: Two hundred fifty-five patients with cancer who required a CVC for at least 7 days were randomly assigned to receive warfarin 1 mg or placebo. RESULTS: There were 11 (4.3%) symptomatic CVC-associated thromboses among 255 patients, with no difference in the incidence of symptomatic CVC-associated thrombosis between patients taking warfarin 1 mg daily (six of 130 patients; 4.6%) and patients taking placebo (five of 125 patients; 4.0%; hazard ratio, 1.20; 95% CI, 0.37 to 3.94). Warfarin had no effect on CVC life span (84 days v 63 days in control and warfarin groups, respectively; 95% confidence limit, -16 to 55 days; P = .09), and it did not affect the number of premature CVC removals (23.2% v 25.4% in control and warfarin groups, respectively; 95% confidence limit of difference -8.34 to 12.71; P = .68) or the frequency of major bleeding episodes (2% v 0% in control and warfarin groups, respectively; P = .5, Fisher's exact test). CONCLUSION: Symptomatic CVC-associated thrombosis in patients with cancer, although significant, is less common than previously reported. In this study, the administration of warfarin 1 mg daily did not reduce the incidence of symptomatic CVC-associated thrombosis in patients with cancer. However, the low rate of symptomatic CVC-associated thrombosis means that a much larger trial is required to address this issue definitively.  相似文献   
10.
Female cross-border migrants experience elevated risks for HIV, and migrants in South Africa may face additional risks due to the country’s underlying HIV prevalence. These risks may be mitigated by the receipt of social support. A behavioral risk-factor survey was administered using respondent-driven sampling. Multivariable regression models assessed the relationships between social support and two HIV outcomes: HIV serostatus and perceived HIV status. Low social support was not significantly associated with HIV status (aOR?=?1.03, 95?% CI 0.43–2.46), but was significantly related to a perception of being HIV positive (aPR?=?1.36, 95?% CI 1.04–1.78). Age, marital status, and education level were significantly associated with HIV serostatus. Illegal border-crossing, length of time in South Africa, anal sex, and transactional sex were significantly associated with aperception of being HIV positive. Future research should investigate how HIV risks and the receipt of social support change throughout the migration process.  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