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   1394篇
  免费   83篇
  国内免费   3篇
耳鼻咽喉   8篇
儿科学   16篇
妇产科学   26篇
基础医学   171篇
口腔科学   35篇
临床医学   81篇
内科学   372篇
皮肤病学   10篇
神经病学   154篇
特种医学   29篇
外科学   284篇
综合类   1篇
预防医学   73篇
眼科学   3篇
药学   41篇
中国医学   1篇
肿瘤学   175篇
  2023年   7篇
  2022年   11篇
  2021年   35篇
  2020年   18篇
  2019年   29篇
  2018年   30篇
  2017年   27篇
  2016年   23篇
  2015年   24篇
  2014年   40篇
  2013年   46篇
  2012年   70篇
  2011年   85篇
  2010年   41篇
  2009年   39篇
  2008年   84篇
  2007年   73篇
  2006年   79篇
  2005年   77篇
  2004年   83篇
  2003年   73篇
  2002年   77篇
  2001年   70篇
  2000年   74篇
  1999年   50篇
  1998年   19篇
  1997年   15篇
  1996年   7篇
  1995年   6篇
  1994年   5篇
  1993年   6篇
  1992年   17篇
  1991年   13篇
  1990年   14篇
  1989年   9篇
  1988年   17篇
  1987年   23篇
  1986年   9篇
  1985年   9篇
  1984年   8篇
  1983年   6篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   5篇
  1978年   4篇
  1977年   3篇
  1976年   2篇
  1970年   4篇
  1967年   1篇
排序方式: 共有1480条查询结果,搜索用时 31 毫秒
1.

Objectives

To determine the incidence of incisional hernia (IH) in the extraction incision (EI) in colorectal resection for cancer. To analyze whether the location of the incision has any relationship with the incidence of hernias and whether mesh could be useful for prevention in high-risk patients.

Methods

Retrospective review of the colon and rectal surgery database from January 2015 to December 2016. Data were classified into 2 groups, transverse (TI) and midline incision (MI), and the latter was divided into 2 subgroups (mesh [MIM] and suture [MIS]). Patients were classified using the HERNIAscore. Hernias were diagnosed by clinical and/or CT examination.

Results

A total of 182 out of 210 surgical patients were included. After a median follow-up of 13.0 months, 39 IH (21.9%) were detected, 23 of which (13.4%) were in the EI; their frequency was lower in the TI group (3.4%) and in the MIM group (5.9%) than in the MIS group (29.5%; p = 0.007). The probability of developing IH in the MIS group showed an OR = 11.7 (95%CI: 3.3-42.0) compared to the TI group and 4.3 (IC 95%: 1.1-16.3) versus the MIM group.

Conclusions

The location of the incision is relevant to avoid incisional hernias. Transverse incisions should be used as the first option. When a midline incision is needed, a prophylactic mesh could be considered in high risk patients because it is safe and associated with low morbidity.  相似文献   
2.
Gastrointestinal (GI) disorders are one of the main adverse events in patients treated by mycophenolic acid (MPA). The aim of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in liver transplant patients presenting GI side-effects Since January 2003, stable liver transplant patients receiving MMF and presenting GI disorders, without evidence of other origin than MMF were enrolled. Conversion was performed without a washout period at an equimolar daily dosage. Thirty-six patients were included after a median delay of 45 months after liver transplantation (LT) (16 women and 20 men, median age of 47 years). Diarrhoea was the main clinical symptom (n = 28, 77.7%). At the time of inclusion, patients were treated with MMF since 18 months (range 3-28) and GI disorders were known for 9 months (range 3-12). After a median follow-up of 12 months after conversion, GI disorders were resolved in 20 patients (55%), improved in 6 patients (17%) and not modified or worsened in 10 patients (28%). Our results strongly suggest that conversion from MMF to EC-MPS in liver transplant patients can improve gastrointestinal disorders in a majority of the patients, and therefore might be considered as the best therapeutic option.  相似文献   
3.
We report the results of a prospective and randomized trial designed to study the incidence of abdominal and pulmonary complications in gallstone surgery comparing subcostal (SI) with midline incision. The need for postoperative analgesia was lower in the SI group. There was no difference in the degree of hypoxaemia in the first two postoperative days, but there was less impairment of pulmonary function in terms of vital capacity and forced expiratory volume in 1 s (P less than 0.0001) in the SI group. SI patients also had a lower incidence of pulmonary or abdominal complications but the difference was not significant. Finally, we found a reduced hospital stay for the SI patients (P less than 0.01), probably related to a reduced postoperative analgesic requirement and an improved pulmonary function. We conclude that subcostal incision is a better approach for biliary tract surgery and should be used whenever possible.  相似文献   
4.
BACKGROUND: Severe ulcerative colitis is potentially life threatening even though a policy of intensive medical management and early colectomy in recent years reduced mortality to almost zero. However, colectomy, with or without ileal-anal anastomosis, has its own problems (morbidity, pouchitis, cuffitis) and no reliable prognostic index of surgical outcome has been developed. Intravenous steroids are still the mainstay of medical therapy but their maximal duration before stating a 'treatment failure' has not been defined. AIM OF THE STUDY: To evaluate the effectiveness, safety and outcome of an intensive medical approach in a series of patients with severe ulcerative colitis. PATIENTS AND METHODS: One hundred and forty-nine episodes of severe ulcerative colitis in 115 patients admitted to a Gastroenterology Unit in a 7-year period were retrospectively evaluated. Intravenous glucocorticosteroids--methylprednisolone 1 mg/kg/day--and topical steroids were administered, and supportive treatments with intensive monitoring were extended to all the patients. Second-line strategies for steroid-refractoriness were prolonged glucocorticosteroids treatment, oral ciclosporin, infliximab or surgery. RESULTS: The median number of Truelove criteria at admission was 3 (range 2-5), median CRP 34 mg/l (range 10-196). Median follow-up after discharge was 49 months. In 84 (57%) episodes an early response was noted, while 65 (43%) did not respond within 10 days to the standard steroid treatment. In the non-responders group, 28 patients went into remission with a prolonged steroid treatment (slow responders); 15 patients were treated with ciclosporin (eight responders) and 6 with infliximab (four responders). A total of 24 colectomies was performed in this group of patients (in 21 cases within 30 days from admission). Slow responders showed lower albumin levels (P = 0.02), higher cumulative dose of glucocorticosteroids in the year prior to admission (P = 0.02) and higher age (P = 0.03), in comparison with early responders. Major complications were noted in four episodes which responded to medical treatment. Disease-related mortality was zero. CONCLUSIONS: Medical treatment and use of second-line therapies were effective in the present series of patients. A group of slow responders has been identified and, if an intensive medical monitoring is guaranteed, steroids can be safely prolonged after the first 10 days of treatment. Cumulatively, about 80% of the patients responded to short-term medical treatment, only 5% of the patients underwent colectomy in the follow-up period. Major adverse events were recorded in four patients, who had recovered completely after adequate medical treatment.  相似文献   
5.
A rare case of an infected chronic hematoma in a patient with immunodeficiency syndrome mimicking a soft tissue neoplasm is presented. There are few reported cases of hematogenous infection of chronic hematomas, which be difficult to differentiate from soft tissue neoplasms.  相似文献   
6.
7.
Escherichia coli O15:K52:H1 is a significant extraintestinal pathogen in Europe (G. Prats et al., J. Clin. Microbiol. 38:201-209, 2000). To search for evidence of this clonal group outside of Europe, 75 non-European E. coli isolates of serogroup O15 were compared with five members of the O15:K52:H1 clonal group from Barcelona, Spain, according to genomic background, virulence genotypes, and antimicrobial resistance profiles. Amplification phylotyping showed that 16 (21%) of the 75 non-European O15 isolates corresponded with the O15:K52:H1 clonal group. The 16 non-European O15:K52:H1 clonal group members represented diverse geographic locales. They were isolated almost exclusively from humans with extraintestinal infections and accounted for 50% of all O15 isolates from five human clinical collections studied. Most non-European clonal group members exhibited a consensus virulence factor profile that included the F16 or F7-2 papA alleles (P fimbrial structural subunit), papG allele II (P fimbrial adhesin), iha (putative adhesin siderophore), and iutA (aerobactin receptor). This resembles the virulence profiles of (i) European representatives of the O15:K52:H1 clonal group and (ii) phylogenetically related "clonal group A," a recently recognized significant contributor to trimethoprim-sulfamethoxazole resistance in the United States (A. R. Manges et al., N. Engl. J. Med. 345:1007-1013, 2001). Antimicrobial resistance profiles were variable, and resistance was inconsistently transferred by conjugation. These findings indicate that the O15:K52:H1 clonal group is broadly distributed beyond Europe, exhibits previously unrecognized phenotypic and genotypic diversity, and contributes significantly to extraintestinal infections in humans.  相似文献   
8.
The study aim was to evaluate the effect of different attentional tasks on the amplitudes and latencies of painful and non-painful contact heat evoked potentials (CHEPs). CHEPs were recorded in 12 healthy subjects during two experimental conditions, in which attention was oriented towards the intensity and the distress caused by the stimuli and were compared with CHEPs recorded during a neutral condition. The painful heat stimulation produced a negative potential at Cz vertex with a latency around 540 ms (Cz/N540), a positive peak at Cz electrode around 730 ms (Cz/P730) and, lastly, a positive peak around 1000 ms (Pz/P1000) in the Pz traces. The Cz/P730 wave was significantly higher in amplitude only during the painful stimulation and is probably related to coding the nociceptive activity. Varying the attentional target towards different properties of the stimulus did not cause any significant change in CHEP responses amplitude and latencies compared with the neutral condition. Our results suggest that CHEPs represent a reliable functional measure of the nociceptive pathways and that they are generated by the activation of different cerebral areas involved in pain processing. The high activation level of each of these area or their spatial neighbouring might explain the strong similarity of CHEP components recorded during different attentional manipulations.  相似文献   
9.
Brain electrical source analysis (BESA) of the scalp electroencephalographic activity is well adapted to distinguish neighbouring cerebral generators precisely. Therefore, we performed dipolar source modelling in scalp medium nerve somatosensory evoked potentials (SEPs) recorded at 1.5-Hz stimulation rate, where all the early components should be identifiable. We built a four-dipole model, which was issued from the grand average, and applied it also to recordings from single individuals. Our model included a dipole at the base of the skull and three other perirolandic dipoles. The first of the latter dipoles was tangentially oriented and was active at the same latencies as the N20/P20 potential and, with opposite polarity, the P24/N24 response. The second perirolandic dipole showed an initial peak of activity slightly earlier than that of the N20/P20 dipolar source and, later, it was active at the same latency as the central P22 potential. Lastly, the third perirolandic dipole exaplaining the fronto-central N30 potential scalp distribution was constantly more posterior than the first one. In order to evaluate the effect of an increasing repetition frequency on the activity of SEP dipolar sources, we applied the model built from 1.5-Hz SEPs to traces recorded at 3-Hz and 10-Hz repetition rates. We found that the 10-Hz stimulus frequency reduced selectively the later of the two activity phases of the first perirolandic dipole. The decrement in strength of this dipolar source can be explained if we assume that: (a) the later activity of the first perirolandic dipole can represent the inhibitory phase of a “primary response”; (b) two different clusters of cells generate the opposite activities of the tangential perirolandic dipole. An additional finding in our model was that two different perirolandic dipoles contribute to the centro-parietal N20 potential generation. Received: 5 August 1997 / Accepted: 26 November 1997  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