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   194篇
  免费   7篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   8篇
基础医学   12篇
口腔科学   6篇
临床医学   15篇
内科学   19篇
神经病学   49篇
特种医学   3篇
外科学   45篇
综合类   1篇
预防医学   18篇
眼科学   3篇
药学   17篇
肿瘤学   4篇
  2023年   1篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   2篇
  2016年   2篇
  2015年   2篇
  2014年   3篇
  2013年   4篇
  2012年   14篇
  2011年   11篇
  2010年   7篇
  2009年   8篇
  2008年   8篇
  2007年   10篇
  2006年   8篇
  2005年   6篇
  2004年   7篇
  2003年   5篇
  2002年   12篇
  2001年   6篇
  2000年   13篇
  1999年   1篇
  1998年   1篇
  1997年   3篇
  1995年   2篇
  1994年   3篇
  1991年   5篇
  1990年   5篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   7篇
  1985年   1篇
  1984年   5篇
  1983年   3篇
  1982年   3篇
  1981年   4篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   5篇
  1974年   1篇
  1972年   1篇
排序方式: 共有202条查询结果,搜索用时 31 毫秒
1.
BACKGROUND AND PURPOSE: Administrative registers, like hospital discharge registers and causes of death registers are used for the monitoring of disease incidences and in the follow-up studies. Obtaining reliable results requires that the diagnoses in these registers are correct and the coverage of the registers is high. The purpose of this study was to evaluate the validity of the Finnish hospital discharge registers and causes of death registers stroke diagnoses against the population-based FINSTROKE register. METHODS: All first stroke events from the hospital discharge registers and causes of death registers from the areas covered by the FINSTROKE register were obtained for years 1993-1998 and linked to the FINSTROKE register. The sensitivity and positive predictive values were calculated. RESULTS: A total of 3633 stroke events, 767 fatal and 2866 non-fatal strokes, were included in the registers. The sensitivity for all first stroke events was 85%, for fatal strokes 86% and for non-fatal strokes 85%. The positive predictive values for all first strokes was 86%, for fatal strokes 92% and for non-fatal strokes 85%. The sensitivity as well as the positive predictive values for subarachnoid haemorrhage and intracerebral haemorrhage was higher than for cerebral infarctions. There were no marked differences in the sensitivity or positive predictive values between men and women. CONCLUSIONS: The sensitivity and the positive predictive values of the Finnish hospital discharge registers and causes of death registers are fairly good. Finnish administrative registers can be used for the monitoring of stroke incidence, but the number of cerebral infarctions should be interpreted with caution.  相似文献   
2.
Summary Some of the properties of three continuous cell lines derived from BK virus-induced hamster tumors were examined. The cell lines hadin vitro growth characteristics of transformed cells. Morphologically most of the cells were fibroblastic, but multinucleated giant cells were also common. Ultrastructurally all three cell lines displayed the usual features of cells grownin vitro. Marked variation in the nuclear size and shape as well as prominent nucleoli were characteristic to these cells. No viruses or virus-like particles were found. Virus isolation attempts by fusing the cells with Vero cells were negative, and no virion antigen was detected in these cells by immunofluorescence. T antigen similar to that of other papovaviruses was found in the cells. This antigen stained with sera from a number of hamsters carrying transplanted BK virus-induced tumors, and also with SV 40 T antisera. The antigen disappeared after 30 minutes at 56° C. Cytogenetic analyses showed that the three cell lines were heteroploid with subtetraploid numbers of chromosomes. Chromosome abnormalities were also seen. All three cell lines induced sarcomatous tumors in adult hamsters after subcutaneous inoculation.With 4 Figures  相似文献   
3.
Autonomic nervous system (ANS) involvement is frequently found in Parkinson's disease (PD), but its causal relationship to the disease itself and its medication is unclear. We evaluated the effects of PD medications on cardiovascular ANS functions. Heart rate (HR) responses to normal and deep breathing, the Valsalva manoeuvre and tilting, and blood pressure (BP) responses to tilting and isometric work were measured prospectively in 60 untreated PD patients randomised to receive either levodopa (n=20), bromocriptine (n=20) or selegiline (n=20) as their initial treatment. The results were compared with those of 28 healthy controls. The responses were recorded at baseline, after 6 months on medication and following a 6-week washout period. At baseline HR responses to normal breathing, deep breathing and tilting were already lower and the fall in the systolic BP immediately and at 5 min after tilting was more pronounced in the PD patients than in the controls. Six months' levodopa treatment diminished the systolic BP fall after tilting when compared to baseline, whereas bromocriptine and selegiline increased the fall in systolic BP after tilting and selegiline diminished the BP responses to isometric work. The BP responses returned to the baseline values during the washout period. The drugs induced no change in the HR responses. Thus PD itself causes autonomic dysfunction leading to abnormalities in HR and BP regulation and the PD medications seem to modify ANS responses further. Bromocriptine and selegiline, in contrast to levodopa, increase the orthostatic BP fall and supress the BP response to isometric exercise reflecting mainly impairment of the sympathetic regulation. Received: 17 February 2000 / Received in revised form: 25 May 2000 / Accepted: 15 June 2000  相似文献   
4.
5.
Recent experimental studies have shown that developing cortex in several animals species, including humans, exhibits spontaneous intermittent activity that is believed to be crucial for the proper wiring of early brain networks. The present study examined the developmental changes in these spontaneous activity transients (SAT) and in other ongoing cortical activities in human preterm babies. Full-band electroencephalography (FbEEG) recordings were obtained from 16 babies at conceptional ages between 32.8 and 40 wk. We examined the SATs and the intervening ongoing cortical activities (inter-SAT; iSAT) with average waveforms, their variance and power, as well as with wavelet-based time-frequency analyses. Our results show, that the low frequency power and the variance of the average waveform of SAT decrease during development. There was a simultaneous increase in the activity at higher frequencies, with most pronounced increase at theta-alpha range (4-9 Hz). In addition to the overall increase, the activity at higher frequencies showed an increased grouping into bursts that are nested in the low frequency (0.5-1 Hz) waves. Analysis of the iSAT epochs showed a developmental increase in power at lower frequencies in quiet sleep. There was an increase in a wide range of higher frequencies (4-16 Hz), whereas the ratio of beta (16-30 Hz) and theta-alpha (4-9 Hz) range activity declined, indicating a preferential increase at theta-alpha range activity. Notably, SAT and iSAT activities remained distinct throughout the development in all measures used in our study. The present results are consistent with the idea that SAT and the other ongoing cortical activities are distinct functional entities. Recognition of these two basic mechanisms in the cortical activity in preterm human babies opens new rational approaches for an evaluation and monitoring of early human brain function.  相似文献   
6.
Keloids are a major complication related to surgical wound healing and very challenging condition to treat. Many treatment options are available, but the efficacy of the treatment is poor in most of cases and some keloids do not respond to the treatment at all. We compared the efficacy of intralesional 5‐fluorouracil (5‐FU) and triamcinolone (TAC) injections in a double‐blind randomized controlled trial (RCT). Forty‐three patients with 50 keloid scars were treated with either intralesional TAC or 5‐FU‐injections over 6 months. We wanted to find out whether biological features (cell density, cell proliferation rate, vascular density, myofibroblast numbers, steroid hormone receptor expression) in keloids could be used to predict the response to therapy and define the biological changes that take place in patients receiving a response. As there was no statistically significant difference in the remission rate between TAC and 5‐FU treatments, all patients were combined and analyzed as responders and nonresponders. Although responders have slightly more myofibroblasts than the nonresponders in their keloids in the pretreatment biopsy samples, we could not identify a single predictive factor that could identify those patients that respond to drug injections. The good clinical response to therapy is associated with the simultaneous reduction of myofibroblasts in the keloid. This study demonstrates that myofibroblasts are reduced in number in those keloids that were responsive to therapy, and that both 5‐FU and TAC injections are useful for keloid treatment.  相似文献   
7.

Background

The long-term efficacy of laparoscopic Roux-en-Y gastric bypass (RYGB) in the treatment of morbid obesity has been demonstrated. Laparoscopic sleeve gastrectomy (SG) as a single procedure has shown promising short-term results, but the long-term efficacy of SG has not yet been demonstrated. The aim of this study was to determine the preliminary 30-day morbidity and mortality of RYGB and SG in a prospective multicenter randomized setting.

Methods

A total of 240 morbidly obese (BMI?=?35–66?kg/m2) patients evaluated by a multidisciplinary team were randomized to undergo either RYGB or SG. There were 117 patients in the RYGB group and 121 in the SG group; two patients had to be excluded after randomization. Both study groups were comparable regarding age, gender, BMI, and comorbidities.

Results

There was no 30-day mortality. The median operating time was significantly shorter in the SG group (66?min vs. 94?min, p?p?=?0.292). Nine (7.4 %) SG patients and 20 (17.1 %) RYGB patients had minor complications (p?=?0.023). The overall morbidity was 13.2 % after SG and 26.5 % after RYGB (p?=?0.010). There were three (2.5 %) early reoperations after SG and four (3.3 %) after RYGB (p?=?0.719).

Conclusions

At 30-day analysis SG is associated with a shorter operating time and fewer early minor complications compared to RYGB. There were no significant differences in major complications or early reoperations. Long-term follow-up is required to determine the effect on weight loss, resolution of obesity-related comorbidities, and improvement of quality of life.  相似文献   
8.
9.
Background: The Swedish adjustable gastric band (SAGB) was introduced in 1985 and rapidly gained popularity.Today more than 21,000 gastric banding procedures have been performed in Europe. The reported results of gastric banding operations are mainly good, although the method is not without controversies and risks. We report here our initial experience with the SAGB. Methods: 60 patients (44 women, 16 men) were treated surgically for morbid obesity between the years 1996 and 1999, with SAGB. Median age of the patients was 44 years (range 21-64) and preoperative median Body Mass Index (BMI, kg/m2) was 45 (range 35-55). 3 patients were operated by an open approach, and the remaining 57 laparoscopically. Results:Operative time was 62-206 minutes (median 97 minutes). Only one operation was converted to open approach (1.8%), due to extensive adhesions. No intraoperative complications occurred. At 1 year follow-up, mean weight loss was 30 kg, mean excess weight loss was 50%, and median BMI was 35. 4 patients have been reoperated so far (6.7%) due to slippage of the band (2 patients), infection of the band (1 patient), and leaking of the filling system (1 patient). Median postoperative hospital stay was 3 days (range 2-53). Mortality was 0%. Immediate postoperative mor- bidity-rate was 12% (7/60), although serious morbidity occurred in only 1 patient (1.7%). Conclusions: Laparoscopically placed adjustable gastric band is a good option for the morbidly obese patient.  相似文献   
10.
Summary Oculosphygmography (OSG), combined with electrocardiography, was performed on 38 male workers exposed occupationally to carbon disulfide (CS2) and 40 unexposed male paper mill workers. A statistical analysis of the results showed that the ocular pulse wave of the exposed group showed a significantly lower pattern than that of the unexposed group. A comparison between workers currently exposed to CS2 and those no longer exposed indicated that the hemodynamic alterations caused by CS2 exposure lead to a permanent condition. It is concluded that CS2 exposure increases the rigidity of the vascular bed of the eye. The data indicate that primarily chronic, subclinical CS2 poisoning causes capillary damage. Oculosphygmography seems to be one objective examination useful in diagnosing the subtle syndrome of chronic CS2 poisoning.
Zusammenfassung Oculosphygmographie und gleichzeitige Elektrokardiographie wurde bei 38 Arbeitern einer Viscose-Industrie mit Schwefelkohlenstoffaussetzung (CS2) und 40 Arbeitern einer Papierindustrie als Kontrollen durchgeführt. Die statistische Analyse der Resultate zeigte bei der CS2 ausgesetzten Gruppe eine signifikant niedrigere Pulswelle als bei den Kontrollen. Bei Vergleich der Pulswelle von Arbeitern, die noch unter CS2-Aussetzung standen mit Arbeitern, die nicht mehr ausgesetzt waren, konnte eine permanente Veränderung festgestellt werden. Es wurde angenommen, daß CS2 die Rigidität des Gefäßbettes des Auges erhöht. Die Resultate weisen auf eine primäre Schädigung der Kapillaren hin. Oculosphygmographie bietet eine zusätzliche Methode zum Feststellen von frühen Schädigungen durch CS2.
  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