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   12911篇
  免费   732篇
  国内免费   26篇
耳鼻咽喉   101篇
儿科学   384篇
妇产科学   187篇
基础医学   1623篇
口腔科学   409篇
临床医学   1373篇
内科学   2535篇
皮肤病学   159篇
神经病学   1246篇
特种医学   352篇
外科学   2024篇
综合类   101篇
一般理论   9篇
预防医学   859篇
眼科学   306篇
药学   1027篇
中国医学   19篇
肿瘤学   955篇
  2023年   103篇
  2022年   132篇
  2021年   236篇
  2020年   220篇
  2019年   312篇
  2018年   296篇
  2017年   279篇
  2016年   310篇
  2015年   302篇
  2014年   431篇
  2013年   671篇
  2012年   884篇
  2011年   889篇
  2010年   475篇
  2009年   470篇
  2008年   802篇
  2007年   839篇
  2006年   785篇
  2005年   712篇
  2004年   696篇
  2003年   663篇
  2002年   601篇
  2001年   133篇
  2000年   105篇
  1999年   146篇
  1998年   171篇
  1997年   158篇
  1996年   123篇
  1995年   105篇
  1994年   113篇
  1993年   83篇
  1992年   86篇
  1991年   99篇
  1990年   91篇
  1989年   88篇
  1988年   68篇
  1987年   70篇
  1986年   74篇
  1985年   90篇
  1984年   74篇
  1983年   63篇
  1982年   92篇
  1981年   53篇
  1980年   52篇
  1979年   53篇
  1978年   41篇
  1977年   33篇
  1976年   35篇
  1975年   25篇
  1974年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.

Background

Long-term cognitive impairment occurs in up to 60% of intensive care unit (ICU) survivors. Early use of functional and cognitive rehabilitation interventions, while patients are still in ICU, may reduce cognitive decline. We aim to describe the functional and cognitive interventions used during the ICU stay, the healthcare professionals providing interventions, and the potential impact on functional and cognitive rehabilitation.

Method

In this integrative systematic review, we will include empirical qualitative, quantitative, mixed- and multiple-methods studies assessing the use of functional and cognitive rehabilitation provided in ICU. We will identify studies in relevant electronic databases from 2012 to 2022, which will be screened for eligibility by at least two reviewers. Literature reported as narrative reviews and editorials will be excluded. We will assess the impact of interventions evaluating a cognitive and functional function, quality of life, and all-cause mortality at 6–12 months after ICU discharge. The Revised Cochrane risk-of-bias Tool will be used for assessing risk of bias in clinical trials. For observational studies, we will use the National Institutes of Health Quality Assessment tool for Observational Cohort and Cross-Sectional Studies. Furthermore, we will use the critical appraisal skills programme for qualitative studies and the mixed methods appraisal tool for mixed methods studies. We will construct four matrices, including results describing which ICU patients and healthcare professionals were engaged in rehabilitation, which interventions were included in early rehabilitation in ICU, the potential impact on patient outcomes of rehabilitation interventions provided in ICU and a narrative synthesis of themes. A summary of the main results will be reported using modified GRADE methodology.

Impact

This integrative review will inform the feasibility randomised clinical trial testing the development of a complex intervention targeting functional and cognitive rehabilitation for patients in ICU.  相似文献   
102.
103.
The aim of the study was to evaluate the use of a vaginal pessary in the detection of genuine stress incontinence (GSI) in women with urogenital prolapse undergoing urodynamic investigation. Continent women with urogenital prolapse, with or without associated urinary symptoms, were studied. All underwent video-cystourethrography using a standarized protocol. None had evidence of incontinence on provocative testing in the upright position. A well-fitting vaginal ring pessary was inserted to reduce the prolapse and mimic a vaginal repair. The provocative tests were then repeated while the bladder was screened. Seventy women with a mean age 59.0 years (range 34–83) were recruited over a 21-month period: 15 women complained of prolapse alone and 55 had concurrent urinary symptoms; 19 women (27%) developed GSI only following the insertion of a vaginal pessary. The women who became incontinent were significantly older (mean age 63.9 years) than those who remained continent (mean age 56.8 years) (P<0.020). The use of a vaginal pessary increases the detection rate of GSI in continent women with urogenital prolapse undergoing videocystourethrography. These findings are important becasuse women with prolapse and coexisting incontinence should be offered a continence procedure rather than a simple vaginal repair.Editorial Comment: All patients with significant uterovaginal prolapse require preoperative evaluation to rule out the presence of potential stress incontinence. The simplest and best way to perform this preoperatively has yet to be determined, although several methods have been described. These include a cough stress test or cough urethral profile performed with a full bladder with the prolapse reduced with a Sims' speculum, a pessary or vaginal packing. A pad test with the prolapse reduced in a similar fashion has also been used clinically to identify patients at risk for postoperactive potential stress incontinence following correction of pelvic prolapse. The authors present their experience using a ring pessary to reduce the prolapse during videourodynamic evaluation of lower urinary tract function, finding this technique to be effective in identifying patients who leak only with the pessary in place, and therefore, require an incontinence procedure. The pickup rate for this cohort of patients is similar to previous studies using alternative methods of detection. Perhaps the only question yet to be answered is the percentage of patients with negative testing preoperatively, yet who develop urinary incontinence immediately following surgical correction of pelvic relaxation. Only this determination will truly assess the clinical utility of the preoperative methods used to identify potential stress incontinence.  相似文献   
104.
Background: Sevoflurane undergoes Baralyme- or soda lime-catalyzed degradation in the anesthesia circuit to yield compound A (2-[fluoromethoxy]-1,1,3,3,3-pentafluoro-1-propene), which is nephrotoxic in rats and undergoes metabolism via the cysteine conjugate beta-lyase pathway in those animals. The objective of these experiments was to test the hypothesis that compound A undergoes beta-lyase-dependent metabolism in humans.

Methods: Human volunteers were anesthetized with sevoflurane (1.25 minimum alveolar concentration, 3%, 2 l/min, 8 h) and thereby exposed to compound A. Urine was collected at 24-h intervals for 72 h after anesthesia. Rats, which served as a positive control, were given compound A intraperitoneally, and urine was collected for 24 h afterward. Human and rat urine samples were analyzed by19 F nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry for the presence of compound A metabolites.

Results: Analysis of human and rat urine showed the presence of the compound A metabolites [S-[2-(fluoromethoxy)-1,1,3,3,3-pentafluoropropyl]-N-acetyl-L-cysteine, (E)- and (Z)-S-[2-(fluoromethoxy)-1,3,3,3-tetrafluoro-1-propenyl]-N-acetyl-L-cyst eine, 2-(fluoromethoxy)-3,3,3-trifluoropropanoic acid, 3,3,3-trifluorolactic acid, and inorganic fluoride. The presence of 2-(fluoromethoxy)-3,3,3-trifluoropropanoic acid and 3,3,3-trifluorolactic acid in human urine was confirmed by gas chromatography-mass spectrometry.  相似文献   

105.
BACKGROUND: To evaluate the feasibility of endoscopic surgery with image guidance in the treatment of inverted papillomas. STUDY DESIGN AND SETTING: This prospective cohort study comprised 42 consecutive patients with biopsy-confirmed inverted papillomas that were diagnosed between 1998 and 2003. All patients were treated by the first author (C.B.). Image guidance based on preacquired CT scans of the patients was used to assist the surgeon aiming at endoscopic resection of inverted papilloma. The success of the surgery was judged primarily by the recurrence rate and the treatment morbidity. RESULTS: The study group consisted of 30 males and 12 females with a median age of 61 years. The follow-up period ranged from 9 months to 69 months (median, 37 months). The only additional procedure performed was the Caldwell-Luc procedure (8 cases). Recurrence was diagnosed in 10 cases (24%), all in the original tumor site. Eight of these had undergone previous surgery for inverted papilloma. The recurrences were predominantly located in the maxillary or in the frontal sinus (8 cases). In 2 cases, the recurrence was simply removed endoscopically while performing the biopsy procedure. All recurrences were identified within the first 9 months. Associated malignancy was not shown. No severe complications occurred. CONCLUSIONS: A treatment based on endoscopic resection with image guidance appears to offer a safe treatment modality of inverted papilloma with insignificant morbidity. Predominantly cases with nonmedial involvement of the maxillary sinus still require a supplement with the Caldwell Luc procedure. Although all the recurrences were found within 9 months postoperatively, later recurrences cannot be excluded. Long-term follow-up is recommended.  相似文献   
106.
AIM: Knee arthroplasties, both total (TKA) and unicondylar, as well as high tibial osteotomy (HTO) represent the main treatment options in severe osteoarthritis of the knee. The aim of this study was to collect detailed information regarding the current treatment strategies in Germany. METHODS: 220 departments of orthopaedic surgery and 250 departments of trauma surgery were asked about their treatment strategies in an anonymous nation-wide survey regarding the different operative procedures in HTO, TKA, revision TKA and related issues. Univariate analyses were performed and means, medians and rates were calculated. RESULTS: Questionnaire forms were answered by 54 % of the departments. The survey represents 31 138 TKA for the year 2002. In the mean 137 TKA were performed in each department. Posterior cruciate ligament retaining components were used in 67 %, resurfacing of the patella was performed in 19 % of cases. The incidence of revision TKA is about 10 % compared to the primary TKA cases. In comparison to a different survey from the year 1995, the absolute number of primary and revision TKA has increased by a factor of nearly three. Compared to the number of TKA, the proportion of HTO has declined to 12 % and the number of unicondylar knee arthroplasties represents 7 % of all cases. CONCLUSION: In the surgical treatment of severe osteoarthritis, TKA shows a highly increasing number, whereas HTO is decreasing. An increasing number of revision TKA can be observed. There is trend towards the cemented implantation technique. Patella resurfacing is not performed routinely in most German hospitals.  相似文献   
107.
Our main hypothesis was that indentation stiffness of the repair tissue approaches the values of adjacent cartilage 1 year after autologous chondrocyte transplantation. We also wanted to investigate the differences between osteochondritic lesions and full-thickness lesions. Thirty patients with cartilage lesions were operated on with autologous chondrocyte transplantation. The repair was evaluated arthroscopically, indentation stiffness was measured, and clinical evaluations were done. The stiffness of the repair tissue improved to 62% (mean 2.04 +/- 0.83 N, mean +/- SD) of adjacent cartilage (3.58 +/- 1.04 N). Fifty-three percent of the patients graded their knee as excellent or good and 47% of the patients graded their knee as fair at the followup. In six patients the normalized stiffness was at least 80%, suggesting hyaline-like repair. The indentation stiffness of the osteochondritis dissecans lesion repairs (1.45 +/- 0.46 N; n = 7) was less than that of the nonosteochondritis dissecans lesion repair sites (2.37 +/- 0.72 N; n = 19). Gadolinium-enhanced magnetic resonance imaging of the cartilage (dGEMRIC) during followup of four patients suggested proteoglycan replenishment, although all grafts showed low indentation values. Low stiffness values may indicate incomplete maturation or predominantly fibrous repair. The indentation analysis showed that the repair tissue stiffness could, in some cases, reach the same level as the adjacent cartilage, but there was a large variation among the grafts.  相似文献   
108.
Background: Neuropathic pain in spinal cord injury is a common challenging therapeutic condition. The current study examines the analgesic effect of the sodium channel blocker lidocaine on neuropathic pain in patients with spinal cord injury and the predictive role of concomitant evoked pain on pain relief with lidocaine.

Methods: Twenty-four spinal cord injury patients with neuropathic pain at or below the level of injury were randomized and completed a double-blind crossover trial of 5 mg/kg lidocaine and placebo infused over 30 min. Twelve patients reported evoked pain, and 12 patients had no evoked pain. Spontaneous and evoked pains were assessed using a visual analog scale and quantitative sensory testing.

Results: Lidocaine significantly reduced spontaneous pain in all patients (P < 0.01) and in each of the two groups with (P < 0.01) and without (P = 0.048) evoked pain, with no difference in number of responders (pain reduction >= 33%) between the patients with (n = 6) and without (n = 5) evoked pain. Lidocaine significantly relieved both at-level and below-level neuropathic pain and decreased brush-evoked dysesthesia but not cold allodynia, pinprick hyperalgesia, or pain evoked by repetitive pinprick.  相似文献   

109.
Background The question whether the tibial component of a total knee arthroplasty should be fixed to bone with or without bone cement has not yet been definitely answered. We studied movements between the tibial component and bone by radiostereometry (RSA) in total knee replacement (TKR) for 3 different types of fixation: cemented fixation (C-F), uncemented porous fixation (UC-F) and uncemented porous hydroxyapatite fixation (UCHA-F).

Patients 116 patients with osteoarthrosis, who had 146 TKRs, were included in 2 randomized series. The first series included 86 unilateral TKRs stratified into 1 of the 3 types of fixation. The second series included 30 patients who had simultaneous bilateral TKR surgery, and who were stratified into 3 subgroups of pairwise comparisons of the 3 types of fixation.

Results After 5 years 2 knees had been revised, neither of which were due to loosening. 1 UCHA-F knee in the unilateral series showed a large and continuous migration and a poor clinical result, and is a pending failure. The C-F knees rotated and migrated less than UC-F and UCHA-F knees over 5 years. UCHA-F migrated less than UC-F after 1 year.

Interpretation Cementing of the tibial component offers more stable bone-implant contact for 5 years compared to uncemented fixation. When using uncemented components, however, there is evidence that augmenting a porous surface with hydroxyapatite may mean less motion between implant and bone after the initial postoperative year.  相似文献   
110.
In forensic medicine, there is an undefined data background for the phenomenon of re-establishment of rigor mortis after mechanical loosening, a method used in establishing time since death in forensic casework that is thought to occur up to 8 h post-mortem. Nevertheless, the method is widely described in textbooks on forensic medicine. We examined 314 joints (elbow and knee) of 79 deceased at defined time points up to 21 h post-mortem (hpm). Data were analysed using a random intercept model. Here, we show that re-establishment occurred in 38.5% of joints at 7.5 to 19 hpm. Therefore, the maximum time span for the re-establishment of rigor mortis appears to be 2.5-fold longer than thought so far. These findings have major impact on the estimation of time since death in forensic casework.  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