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   9845篇
  免费   560篇
  国内免费   87篇
耳鼻咽喉   163篇
儿科学   107篇
妇产科学   117篇
基础医学   1555篇
口腔科学   220篇
临床医学   702篇
内科学   1955篇
皮肤病学   362篇
神经病学   620篇
特种医学   515篇
外科学   1479篇
综合类   36篇
一般理论   3篇
预防医学   387篇
眼科学   207篇
药学   854篇
中国医学   143篇
肿瘤学   1067篇
  2024年   11篇
  2023年   82篇
  2022年   237篇
  2021年   416篇
  2020年   149篇
  2019年   265篇
  2018年   302篇
  2017年   234篇
  2016年   381篇
  2015年   462篇
  2014年   542篇
  2013年   558篇
  2012年   891篇
  2011年   796篇
  2010年   479篇
  2009年   389篇
  2008年   575篇
  2007年   521篇
  2006年   473篇
  2005年   462篇
  2004年   379篇
  2003年   322篇
  2002年   248篇
  2001年   258篇
  2000年   218篇
  1999年   154篇
  1998年   71篇
  1997年   54篇
  1996年   41篇
  1995年   50篇
  1994年   37篇
  1993年   31篇
  1992年   72篇
  1991年   52篇
  1990年   40篇
  1989年   36篇
  1988年   37篇
  1987年   31篇
  1986年   25篇
  1985年   23篇
  1984年   9篇
  1983年   9篇
  1981年   6篇
  1980年   6篇
  1979年   8篇
  1978年   5篇
  1976年   7篇
  1974年   4篇
  1973年   6篇
  1968年   6篇
排序方式: 共有10000条查询结果,搜索用时 21 毫秒
121.
Use of organs from donors testing positive for hepatitis B virus (HBV) may safely expand the donor pool. The American Society of Transplantation convened a multidisciplinary expert panel that reviewed the existing literature and developed consensus recommendations for recipient management following the use of organs from HBV positive donors. Transmission risk is highest with liver donors and significantly lower with non‐liver (kidney and thoracic) donors. Antiviral prophylaxis significantly reduces the rate of transmission to liver recipients from isolated HBV core antibody positive (anti‐HBc+) donors. Organs from anti‐HBc+ donors should be considered for all adult transplant candidates after an individualized assessment of the risks and benefits and appropriate patient consent. Indefinite antiviral prophylaxis is recommended in liver recipients with no immunity or vaccine immunity but not in liver recipients with natural immunity. Antiviral prophylaxis may be considered for up to 1 year in susceptible non‐liver recipients but is not recommended in immune non‐liver recipients. Although no longer the treatment of choice in patients with chronic HBV, lamivudine remains the most cost‐effective choice for prophylaxis in this setting. Hepatitis B immunoglobulin is not recommended.  相似文献   
122.
A perioperative intravenous lidocaine infusion has been reported to decrease postoperative pain. The goal of this study was to evaluate the effectiveness of intravenous lidocaine in reducing postoperative pain for laparoscopic colectomy patients. Fifty-five patients scheduled for an elective laparoscopic colectomy were randomly assigned to 2 groups. Group L received an intravenous bolus injection of lidocaine 1.5 mg/kg before intubation, followed by 2 mg/kg/h continuous infusion during the operation. Group C received the same dosage of saline at the same time. Postoperative pain was assessed at 2, 4, 8, 12, 24, and 48 hours after surgery by using the visual analog scale (VAS). Fentanyl consumption by patient-controlled plus investigator-controlled rescue administration and the total number of button pushes were measured at 2, 4, 8, 12, 24, and 48 hours after surgery. In addition, C-reactive protein (CRP) levels were checked on the operation day and postoperative days 1, 2, 3, and 5. VAS scores were significantly lower in group L than group C until 24 hours after surgery. Fentanyl consumption was lower in group L than group C until 12 hours after surgery. Moreover, additional fentanyl injections and the total number of button pushes appeared to be lower in group L than group C (P < 0.05). The CRP level tended to be lower in group L than group C, especially on postoperative day1 and 2 and appeared to be statistically significant. The satisfaction score was higher in group L than group C (P = 0.024). Intravenous lidocaine infusion during an operation reduces pain after a laparoscopic colectomy.Key words: Analgesics, Colectomy, Pain, LidocaineBecause of a substantial increase in the incidence of benign and malignant tumors of the colon, the number of laparoscopic colorectal surgeries has increased.1 Laparoscopic colectomy appears to be less painful, involves less bleeding, and has a faster recovery than an open colectomy.2 Further, laparoscopic colorectal surgery has been proven to be beneficial in comparison with robot-assisted laparoscopic colorectal surgery in many aspects.3 However, postoperative pain because of surgical incision is still an issue that requires resolution. Therefore, various clinical applications such as intrathecal morphine, epidural analgesia, patient-controlled analgesia (PCA), and nonsteroidal anti-inflammatory drugs (NSAIDs) are used to control pain after a laparoscopic colectomy.4,5 However, optimal management has not yet been established. A regional block can have technical difficulties and complications. The epidural failure rate has been reported up to 40%, and other drugs, such as opioids or NSAIDs, have side effects or drug allergies.5,6Intravenous lidocaine is inexpensive, easy to inject, and a relatively safe drug.7 A number of studies showed that intravenous lidocaine has analgesic, anti-hyperalgesic, and anti-inflammatory properties, as well as a fast recovery, reducing the hospital stay and the time for bowel function recovery.810 In addition, lidocaine in a nontoxic concentration has been reported to decrease the variant volatile anesthesia requirement in an animal study.10 Therefore, the authors aimed to determine whether a continuous infusion of intravenous lidocaine would have an adequate postoperative analgesic effect for a laparoscopic colectomy. The hypothesis of this study was that an intravenous lidocaine infusion during an operation could decrease postoperative pain.  相似文献   
123.
Although recurrent IgA nephropathy (IgAN) may lead to graft dysfunction after transplantation, donation from living related donor (LRD), with whom the risk of recurrence may be higher, is not a contraindication. Herein, we evaluated the natural history of allograft in recipients with IgAN and the risk factors influencing long‐term allograft outcome. Recurrence rate and graft survival were assessed retrospectively in 221 IgAN patients, including transplants from 139 LRDs (62.9%). Ten‐year cumulative rate for recurrent IgAN was 30.8%. The operation at younger age and donation from LRD were significant for the recurrence by multivariate analysis. Ten‐year graft survival was affected by recurrent IgAN (61.0% in recurrent IgAN group vs. 85.1% in nonrecurrent, P < 0.01). However, transplants from LRDs did not show poor graft survival when compared with those from other types of donors. In transplants from LRDs, the incidence of chronic allograft nephropathy (CAN) was lower than those in grafts from deceased donors (10.8% vs. 19.5%, P < 0.05). When CAN was considered in addition to recurrence, the variance of graft survival was affected significantly by the development of CAN than by the recurrence. These results suggest that the detection and adequate management of CAN could improve graft outcome in transplant recipients with IgAN.  相似文献   
124.
Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To compare the outcomes between salvage radiotherapy (RT) and androgen‐deprivation therapy (ADT), to investigate factors determining clinical progression (CP) in men with prostate cancer.

PATIENTS AND METHODS

The study comprised 121 patients with biochemical recurrence while on follow‐up by prostate‐specific antigen (PSA) measurement, without adjuvant therapy after radical prostatectomy, received RT (45) or ADT (76). Failure after salvage therapy was defined as a PSA level of >0.2 ng/mL. Clinical, pathological and treatment factors were analysed.

RESULTS

The clinicopathological characteristics were similar between the RT and ADT groups except that men in the RT group were younger (61.4 vs 65.4 years). After ADT, salvage failed in 10 (13%) after a mean (sd ) of 18.5 (4.5) months of treatment, and 6.7 months after salvage failed all patients progressed clinically. After RT, salvage failed in 22 (49%) after 30.7 (5.2) months of response. Upon RT failure, all patients received ADT, after which in three (14%) patients the treatment failed again after 20.1 months of treatment and progressed to CP after 6.5 months, while in the remaining 19 (86%) patients the PSA level remained undetectable for 37.6 (7.7) months. On multivariate analysis, pathological stage (≥T3b) and Gleason grade 5 disease were independently prognostic of CP.

CONCLUSION

Salvage RT alone and combined with subsequent ADT provided PSA control in most patients, significantly increasing CP‐free survival compared with initial ADT. Patients with a short PSA doubling time (<3 months) are at high risk of failed salvage treatment after RT, and initial ADT might be considered. Regardless of salvage method, advanced pathological stage and Gleason grade 5 were factors prognostic of CP.  相似文献   
125.
Carotid interposition grafts (CIP) for carotid artery revascularization can be a viable alternative to carotid endarterectomy (CEA) or carotid artery stenting (CAS) for complex carotid disease. This is a retrospective review of the UCLA 17-year experience with CIP for carotid reconstruction. Carotid operations performed between 1988 and 2005 revealed 41 CIP procedures in 39 patients using polytetrafluoroethylene (PTFE, n = 31) or reversed greater saphenous vein (Vein) (n = 10). Perioperative data and long-term follow-up for each conduit were statistically compared. There were no significant differences in demographics, risk factors, operative indications, complications, or 30-day perioperative deaths. There was one postoperative stroke in each group, for an overall stroke rate of 4.9% (PTFE 3.2%, Vein 10%). There was one asymptomatic occlusion and there were two high-grade restenoses in the PTFE group compared with one asymptomatic occlusion and one high-grade restenosis in the Vein group. Overall primary patency was 90% and the assisted primary patency was 97% for the PTFE group (mean follow-up 50 months), whereas primary patency was 80% (mean follow-up 30 months) in the Vein group. CIP is a safe and effective technique with excellent long-term follow-up for complex carotid reconstruction when CEA or CAS may be contraindicated.  相似文献   
126.
Laser Punch-Out for Acne Scars   总被引:6,自引:0,他引:6  
Patients with acne scars want smooth facial skin. However, achieving this is difficult with dermabrasion or chemical peeling. Nor can acne scars be covered with cosmetics, due to their ice-picked or cobblestone appearance. Laser resurfacing is more effective and safer than other conventional methods due to its precision with depth control and variable methods of surface cutting. Even depth resurfacing with a laser shows unsatisfactory results, therefore, for the deep-sited acne scar the cutting methods have to be changed according to the depth and pattern of the scar. For 2 years, starting in January 1996, we treated 71 patients with a high-powered CO2 laser (Ultrapulse). Different resurfacing methods were applied according to the depth and pattern of the scars. For mild depressed scars, even depth resurfacing was done. For moderate-depth acne scars, the shoulder technique was also used. For the deepest and ice-picked scars, the laser punch-out was combined. Laser resurfacing was carried out at 300–500 mJ, with two to five passes. Laser punch-out was done at 500 mJ, with three to seven continuous passes on the ice-picked scar. From the pathologic findings of acne scars showing that there was thick intradermal scar, we knew that laser punch-out was necessary for improvement of acne scars. Depth-wide, the ice-picked scars improved by over 80% and the sharp demarcated margin of the acne scar faded out. Most of the patients with acne scars were satisfied with laser resurfacing. Only six patients had a second laser treatment, with an interval of 12 months. There were no hypertrophic scars after laser resurfacing, but erythema lasted for 3–12 months. Patients taking oral retinoic acid were not contraindicated for laser resurfacing but required special caution because they had atrophic skin and delayed wound healing. Laser resurfacing is the most versatile method for acne scars, with a high-powered CO2 laser. The laser punch-out method is better than even depth resurfacing for improving deep acne scars and can be combined with the shoulder technique or even depth resurfacing according to the type of acne scar.  相似文献   
127.
OBJECTIVE: The objective of this study was to determine the value of early (< 6 months) duplex scanning after carotid endarterectomy (CEA) with an intraoperative completion study with normal results. Attention was paid to restenosis rates and reoperation for recurrent stenosis within the first 6 months. METHODS: A retrospective review was performed on 380 CEAs (338 patients) with intraoperative completion studies and duplex surveillance within the first 6 months. Results of completion studies, restenosis rates, and recurrent symptoms were evaluated for each operation. Studies were performed from 0 to 200 days postoperatively (median, 28). RESULTS: Intraoperative completion studies included 333 angiograms, 26 duplex scans, and 21 angiograms with duplex scans. Of the 380 intraoperative completion studies, 28 (7.5%) had abnormal findings, including 14 abnormal internal carotid arteries (ICAs). Twenty-four procedures were revised, and the findings of all repeat completion studies were normal. Of the initial completion studies, in four cases, abnormalities (3 ICAs) were insignificant and did not warrant further intervention. Follow-up ICA duplex scans had normal results after 364 (95.8%) CEAs. There were 14 mild recurrent ICA stenoses and two moderate recurrent ICA stenoses; neither had abnormal findings from the completion study. There were no severe recurrent ICA stenoses. External carotid artery (ECA) recurrent stenosis included 7 mild, 15 moderate, and 9 severe restenoses. CONCLUSIONS: Only 0.5% of CEAs developed moderate restenosis. No procedures had severe recurrent stenosis on duplex scan within the first 6 months, and none required intervention. Duplex surveillance in the first 6 months is relatively unproductive, providing that there were normal results from an intraoperative completion study for each patient. Routine surveillance can be started at 1 year.  相似文献   
128.
It is not well known how the nonoperated contralateral hand behaves in bilateral carpal tunnel syndrome (CTS). The postoperative clinical course of the nonoperated contralateral hand in unilateral CTS is not well documented either. Of 324 CTS patients, the authors studied 37 who had carpal tunnel release on one hand only to evaluate the postoperative outcome of the nonoperated contralateral hand. The other 287 patients had operations on both hands. Seven patients were excluded because of missing data or because they could not be contacted. All 324 patients were subject to clinical and electrodiagnostic studies on both hands. The patients were divided into three groups. Group I was composed of patients who had bilateral CTS, diagnosed clinically and electrophysiologically, but who had surgery done only on the hand with the most pronounced symptoms. The patients in group II showed symptoms of CTS in one hand only. However, the opposite hand was diagnosed with subclinical CTS: Electrodiagnostic studies showed involvement of the median nerve, but without symptoms. Group III was composed of true unilateral CTS patients, diagnosed by symptoms and electrodiagnostic study. The results of the electrodiagnosis were categorized according to the severity of median nerve damage (mild, moderate, severe). The outcome and postoperative clinical course of the nonoperated contralateral hand were evaluated by electromyography and telephone survey. This method of survey was used because of the vast spread of patients throughout the country. Within 1 year, all 30 operated hands showed significant improvement, 20 of which belonged to group I. Regarding progress of the nonoperated contralateral hand, 10 patients showed improvement of one grade whereas 5 patients showed three grades of improvement. In another 5 patients there was no change whatsoever. In addition, from groups II and III there were 5 patients who showed no change in the nonoperated hand. The postoperative electromyographic findings of the nonoperated contralateral hand was not commensurate with the symptoms. However, regardless of electromyographic results, the nonoperated contralateral hand showed significant improvement (p < 0.0001). Patients with unilateral CTS did not experience any symptom development in the nonoperated contralateral hand.  相似文献   
129.
J Y Ahn  S O Kwon  J Y Joo 《Neurologia medico-chirurgica》2001,41(12):603-5; discussion 606
A 50-year-old male presented with an extremely rare dorsal wall aneurysm of the internal carotid artery manifesting as intracerebral hemorrhage. Computed tomography demonstrated intracerebral hemorrhage on the frontal base. Magnetic resonance imaging clearly showed the hemorrhage was related to an aneurysm of the internal carotid artery. Cerebral angiography disclosed an elongated aneurysm of the dorsal wall of the internal carotid artery. The aneurysm was packed as fully as possible with Guglielmi detachable coils to achieve complete obliteration. The patient was discharged without neurological deficits. Dorsal internal carotid artery aneurysms have a high risk of premature rupture due to their unusual shape and position, adhesion to the brain tissue, and fragile neck. Direct clipping requires careful brain retraction, necessary exposure of the aneurysm, and gentle neck manipulation. Endovascular treatment is an alternative method for obliteration of the aneurysmal sac.  相似文献   
130.
AIM: In the elderly with renal disease, the clinical presentations are frequently inconsistent with the pathologic findings. We tried to clarify the differences in pathological findings between the young and the elderly, in Korea and in Western countries, and the usefulness of a percutaneous renal biopsy in the elderly with renal disease. PATIENTS AND METHODS: We analyzed the clinical presentations and spectrums of renal histopathology by reviewing medical records and renal biopsy reports retrospectively in 117 Korean patients aged 60 years or more with renal disease. RESULTS: 85 patients had primary renal disease. The remaining 32 patients had renal diseases associated with systemic conditions. Out of the 85 patients with primary renal disease, 61 cases presented as idiopathic nephrotic syndrome. Compared with renal biopsy results of younger adult patients (age 15-59, n = 1,908), membranous nephropathy, crescentic glomerulonephritis, membranoproliferative glomerulonephritis, amyloidosis, light chain disease, and thrombotic thrombocytopenic purpura were more prevalent, but IgA nephropathy and lupus nephritis were less common in the elderly patients. In clinical presentation, nephrotic syndrome and rapidly progressive renal failure were more prevalent, but asymptomatic urinary abnormality was less common in elderly patients. The responsiveness to treatment was good in elderly patients with minimal-change lesion (complete remission in all patients) but poor in crescentic glomerulonephritis, IgA nephropathy, and membranoproliferative glomerulonephritis. From the above findings, the clinical presentation, patterns of histopathology and responsiveness to treatment of elderly Korean patients were similar to those of the younger Korean control group and the Western elderly group. CONCLUSION: Percutaneous renal biopsy is a useful diagnostic aid and can be used as a therapeutic guideline even in elderly patients with renal disease.  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