全文获取类型
收费全文 | 3645篇 |
免费 | 198篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 152篇 |
妇产科学 | 46篇 |
基础医学 | 446篇 |
口腔科学 | 46篇 |
临床医学 | 250篇 |
内科学 | 589篇 |
皮肤病学 | 54篇 |
神经病学 | 275篇 |
特种医学 | 104篇 |
外科学 | 479篇 |
综合类 | 95篇 |
一般理论 | 2篇 |
预防医学 | 200篇 |
眼科学 | 180篇 |
药学 | 459篇 |
中国医学 | 44篇 |
肿瘤学 | 390篇 |
出版年
2023年 | 39篇 |
2022年 | 65篇 |
2021年 | 122篇 |
2020年 | 68篇 |
2019年 | 86篇 |
2018年 | 114篇 |
2017年 | 79篇 |
2016年 | 109篇 |
2015年 | 100篇 |
2014年 | 118篇 |
2013年 | 165篇 |
2012年 | 267篇 |
2011年 | 270篇 |
2010年 | 164篇 |
2009年 | 135篇 |
2008年 | 194篇 |
2007年 | 180篇 |
2006年 | 173篇 |
2005年 | 164篇 |
2004年 | 145篇 |
2003年 | 116篇 |
2002年 | 96篇 |
2001年 | 50篇 |
2000年 | 68篇 |
1999年 | 52篇 |
1998年 | 30篇 |
1997年 | 19篇 |
1996年 | 24篇 |
1995年 | 21篇 |
1994年 | 20篇 |
1993年 | 19篇 |
1992年 | 45篇 |
1991年 | 41篇 |
1990年 | 33篇 |
1989年 | 55篇 |
1988年 | 44篇 |
1987年 | 37篇 |
1986年 | 32篇 |
1985年 | 31篇 |
1984年 | 28篇 |
1983年 | 27篇 |
1982年 | 15篇 |
1981年 | 16篇 |
1979年 | 34篇 |
1978年 | 15篇 |
1976年 | 14篇 |
1974年 | 10篇 |
1973年 | 15篇 |
1972年 | 14篇 |
1970年 | 10篇 |
排序方式: 共有3857条查询结果,搜索用时 31 毫秒
31.
Finucane BT Ganapathy S Carli F Pridham JN Ong BY Shukla RC Kristoffersson AH Huizar KM Nevin K Ahlén KG;Canadian Ropivacaine Research Group 《Anesthesia and analgesia》2001,92(5):1276-1285
We evaluated the safety and efficacy of a 72-h epidural infusion of ropivacaine and measured the impact of adding fentanyl 2 microg/mL to the required infusion rate, on the quality of postoperative pain relief and the incidence of side effects, after colonic surgery. One hundred fifty-five patients scheduled for elective colonic surgery were randomized in this trial. Epidural infusions of ropivacaine 2 mg/mL with fentanyl 2 microg/mL (R + F) and without fentanyl (R) were commenced during surgery and continued for 72 h postoperatively. This was a prospective, randomized, double-blinded, multi-center trial. The median infusion rate required was less in the R + F group (9.3 vs 11.5 mL/h, P < 0.001). Median pain scores at rest and on coughing were lower in the R + F group (P < 0.0001). The incidence of hypotension was more in the R + F group (P = 0.01). Time to readiness for discharge was delayed in the R + F group (median 6.6 vs 5.5 days, P = 0.012). The addition of fentanyl to ropivacaine resulted in decreased infusion rates and enhanced pain control; however, adverse effects were increased and readiness to discharge was delayed. IMPLICATIONS: Epidural infusions of ropivacaine with and without fentanyl were administered to patients to control pain after colonic surgery. Patients who received ropivacaine with fentanyl had better pain control, increased side effects, and delayed readiness to discharge. This study questions the value of adding opioids to epidural infusions of local anesthetics. 相似文献
32.
Carcinoma gallbladder is the commonest malignancy in the Northern part of India. The heavy metals are known carcinogens while trace metals have protective effect. Aim The aim of the study is to estimate the heavy and trace metal (Lead, Zinc, Copper, Cadmium, Chromium, Manganese and Selenium) concentration in serum, bile, tissue and gallstone in patients with gallbladder diseases. Method This is a pilot study conducted in 45 cases (Group – I: 15 cases of carcinoma gallbladder, Group II: 15 patients of cholecystitis with cholelithiasis and Group – III: 15 patients of healthy control), to detect the relationship between the heavy and trace metal concentration and gall bladder carcinoma. Analysis of metal was done using Perkins‐Elmer model 2380 atomic absorption spectrophotometer. Results The serum concentration of copper and nickel was significantly high in carcinoma gallbladder patients as compared to patients with cholecystitis while zinc and selenium is low in carcinoma gallbladder patients. Bile concentration of zinc, selenium and manganese was significantly low in carcinoma gallbladder patients (p < 0.05) as compared to patients of cholelithiasis while cadmium and nickel was high. Tissue concentration of manganese was significantly low in carcinoma gallbladder patients as compared to patients of cholelithiasis while chromium was high. Gallstone concentration of copper, manganese and lead was significantly low in carcinoma gallbladder patients as compared to patients of cholelithiasis. Conclusion The heavy metals are in higher concentration in carcinoma gallbladder while trace metals are in lower concentration indicating possible role of heavy metal in gallbladder carcinogenesis. 相似文献
33.
34.
35.
The herniation of abdominal contents through a diaphragmatic and chest wall rent has been uncommonly reported in literature. Also known as a transdiaphragmatic intercostal hernia (TDIH) or intercostal pleuroperitoneal hernia, it occurs when the disruption of diaphragmatic or intercostal muscles leads to an acquired herniation of abdominal contents. It is usually seen to occur following a traumatic incident. We report the case of an elderly male who presented with a reducible lump in the left chest and breathlessness on exertion, in the absence of any trivial or occult trauma, and how this was managed adequately via surgery alone. 相似文献
36.
Yogesh S Kashyap P S Yadav Tushar Roy P S Sarkar M Shukla Amar Sinha 《Applied radiation and isotopes》2008,66(8):1083-1090
In-line X-ray phase-contrast imaging technique is an emerging method for the study of materials such as carbon fibers, carbon composite materials, polymers, etc. Similarly this technique is also well suited for the imaging of soft materials such as tissues, distinguishing between tumor and normal tissue. These represent the class of materials for which X-ray attenuation cross-section is very small. Thus this method promises a far better contrast for low X-ray absorbing substances than the conventional radiography method. We have set up an experimental facility using a combination of X-ray CCD detector and a microfocus X-ray source. This facility is dedicated to micro-imaging experiments such as microtomography and high-resolution phase-contrast experiments. In this paper, the results of X-ray phase-contrast imaging experiments are described. 相似文献
37.
Background
A perfect rotational alignment could be achieved if the implant rotation is individualized for each knee before operation. The anatomic transepicondylar axis (aTEA) is a standard reference for setting the femoral component rotation. Intraoperative localization of aTEA is difficult. However, aTEA could be readily identified on preoperative CT scans, and condylar twist angle (CTA) could be determined preoperatively. The femoral component can subsequently be implanted according to CTA. Therefore, perfect intraoperative rotational alignment can be easily achieved. The aim of the study was to evaluate the role of preoperative calculation of CTA by CT scan in optimizing femoral component rotation during TKA.Materials and methods
We analyzed fifty-three total knee arthroplasty in 36 primary osteoarthritis patients, aged 49–78 years. CTA was measured on preoperative CT scan. Intraoperative equal magnitude of external rotation was set so that the femoral cut was parallel to aTEA. Postoperative CT scan was done to confirm the femoral component rotation.Results
Postoperatively, femoral component was parallel to aTEA with a mean error of 0.77°. In 34 knees (64.15%), surgical transepicondylar axis (sTEA) could also be determined; average angle between sTEA and aTEA was 4.65°. Femoral component in these knees was found to be parallel or externally rotated in relation to sTEA (mean 4.22°).Conclusion
Preoperative calculation of CTA by CT scan helps to optimize the femoral component rotation during TKA.38.
39.
Harpaz N Schiano T Ruf AE Shukla D Tao Y Fishbein TM Sauter BV Gondolesi GE 《Transplantation》2005,80(12):1667-1670
BACKGROUND: Recurrence of Crohn's disease in small intestinal allografts, although rarely described, can cause serious morbidity and jeopardize graft survival among transplant recipients with Crohn's disease. However, systematic studies to determine the frequency, predictors, and clinical implications of recurrent Crohn's disease have not been reported METHODS: We analyzed our transplant program's experience with small intestinal allografts in patients with Crohn's disease based on retrospective review of clinical and pathological records and corresponding pathology slides. RESULTS: Of 67 patients undergoing 70 transplantations between 1998 and 2004, six adults (three males, three females; mean age 48.1 years) had Crohn's disease complicated by short gut syndrome and total parenteral nutrition failure. Four survivors surveyed endoscopically for a mean 29 (range, 20-40) months and underwent a mean 37 endoscopic examinations with biopsies (range, 31-44) while on maintenance immunosuppression. Despite absence of any endoscopic or clinical manifestations of Crohn's disease throughout this period, two patients had granulomatous enteritis characteristic of Crohn's disease in multiple biopsies, one patient in 8/44 examinations (18%) ranging from 34 days to 20 months postoperatively and the other in 6/32 examinations (19%) ranging from 20 days to 22 months postoperatively. No comparable changes occurred in 57 other patients without Crohn's disease followed endoscopically under the same protocol CONCLUSIONS: Histological recurrence of Crohn's disease may occur in small intestinal allografts despite the absence of endoscopic and clinical disease manifestations. Such recurrences are probably not rare, may occur as early as 3 weeks after transplantation, and do not necessarily portend early clinical recurrence or mandate aggressive therapy to prevent allograft loss. 相似文献
40.
Ajay Puri Manish G. Agarwal Mandip Shah C.H. Srinivas P.J. Shukla S.V. Shrikhande Nirmala A. Jambhekar 《The spine journal》2009,9(5):396-403
Background contextPrimary tumors of the sacrum are extremely rare lesions. Their management is governed by an interplay of complex factors. Appropriate decision making is crucial to obtain the best possible outcome in terms of maximizing disease control while attempting to minimize neurological dysfunction.PurposeOur study presents the results of a group of patients with primary tumors of the sacrum who were surgically treated by the same multidisciplinary team at a specialist oncology center over a relatively short period of time (5 years).Study design/settingPatients were identified by a retrospective review from a prospectively maintained database.Patient sampleBetween January 2000 and December 2005, 17 primary sacral tumors were surgically treated at our institution, a referral center for oncology.Outcome measuresWe evaluated the outcome in terms of local disease control, residual neurological dysfunction, and complications as a result of surgical intervention.MethodsThere were 12 males and 5 females. The diagnosis included chordoma in six patients, giant cell tumor in seven patients, aneurysmal bone cyst in two patients, and a chondrosarcoma and an osteoblastoma in one patient each. Sixteen of these patients were analyzed. Four lesions had their upper extent at S1, six lesions had their upper extent at S2, four lesions had their upper extent at S3, and two lesions were below S3. Ten cases were treated with wide excision and underwent partial sacral amputations. Five cases had a midline sacral amputation through S1, three through S2, and two through S3. Six benign lesions were treated with curettage. None of the patients received chemotherapy. Four cases received postoperative radiation. The follow-up duration ranged from 18 to 44 months with a mean of 31 months.ResultsNone of the six patients who presented with loss of bladder and bowel control regained it after surgery. Of the 10 patients who had intact bladder and bowel control preoperatively only 4 retained bladder and bowel control postoperatively. Of the six patients who lost bladder and bowel control postoperatively, four patients had a wide excision where bilateral S2 roots were sacrificed. The other two cases in whom the disease extended up to S1 had curettage. Local recurrence occurred in 4 of the 10 lesions treated with wide excision. All the patients who had inadequate margins recurred. Local recurrence occurred in two of the six lesions treated with curettage. Three of the four cases who received postoperative irradiation developed recurrence. Our wound complication rate was 13%.ConclusionWide resection with adequate margins gives the best chance of local control and should be the surgery of choice for all malignant primary sacral tumors and in benign lesions involving lower segments when preservation of both S3 roots is possible. Intralesional curettage has a higher risk of local recurrence without providing the certainty of retaining neurological function. To retain bladder and bowel control and minimize neurological dysfunction, it may be worthwhile managing benign sacral tumors that extend above S3 with serial embolization. The administration of parentral bisphosphonates may prove beneficial in cases of giant cell tumor managed with serial embolization. 相似文献