全文获取类型
收费全文 | 1088043篇 |
免费 | 80669篇 |
国内免费 | 2968篇 |
专业分类
耳鼻咽喉 | 13980篇 |
儿科学 | 36774篇 |
妇产科学 | 30080篇 |
基础医学 | 156592篇 |
口腔科学 | 29364篇 |
临床医学 | 99994篇 |
内科学 | 211417篇 |
皮肤病学 | 24076篇 |
神经病学 | 88262篇 |
特种医学 | 41875篇 |
外国民族医学 | 308篇 |
外科学 | 163952篇 |
综合类 | 24751篇 |
一般理论 | 512篇 |
预防医学 | 85441篇 |
眼科学 | 24589篇 |
药学 | 77726篇 |
3篇 | |
中国医学 | 2125篇 |
肿瘤学 | 59859篇 |
出版年
2021年 | 8705篇 |
2019年 | 9173篇 |
2018年 | 12829篇 |
2017年 | 9850篇 |
2016年 | 11147篇 |
2015年 | 12609篇 |
2014年 | 17458篇 |
2013年 | 26267篇 |
2012年 | 35753篇 |
2011年 | 37979篇 |
2010年 | 22621篇 |
2009年 | 21160篇 |
2008年 | 35171篇 |
2007年 | 37128篇 |
2006年 | 37467篇 |
2005年 | 35854篇 |
2004年 | 34964篇 |
2003年 | 33271篇 |
2002年 | 31993篇 |
2001年 | 47678篇 |
2000年 | 48532篇 |
1999年 | 41074篇 |
1998年 | 12282篇 |
1997年 | 10917篇 |
1996年 | 10840篇 |
1995年 | 10401篇 |
1994年 | 9626篇 |
1993年 | 8990篇 |
1992年 | 32633篇 |
1991年 | 31815篇 |
1990年 | 31304篇 |
1989年 | 30147篇 |
1988年 | 27423篇 |
1987年 | 27565篇 |
1986年 | 25654篇 |
1985年 | 24857篇 |
1984年 | 18678篇 |
1983年 | 15753篇 |
1982年 | 9602篇 |
1979年 | 16945篇 |
1978年 | 12333篇 |
1977年 | 10407篇 |
1976年 | 9822篇 |
1975年 | 10235篇 |
1974年 | 12373篇 |
1973年 | 11910篇 |
1972年 | 10933篇 |
1971年 | 10143篇 |
1970年 | 9397篇 |
1969年 | 8755篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Use of Vicryl (polyglactin 910) mesh to limit epidural scar formation after laminectomy 总被引:1,自引:0,他引:1
A variety of substances have been used at laminectomy sites to prevent postoperative epidural scarring. Free grafts of autologous subcutaneous fat are commonly used both clinically and experimentally. The free fat grafts usually survive, but decrease in size by about 50%. Postoperatively, subcutaneous seroma has been observed with the use of fat grafts, as well as recurrent symptoms of neural compression by the graft that required additional operations. When compared to the use of free grafts after laminectomy in dogs, Vicryl mesh produced slightly more scarring, but consistently less than that observed in control animals. The Vicryl mesh was resorbed by a minimal chronic inflammatory response over about 45 days. Seven of 11 fat-grafted zones showed signs of necrosis, at times with a greater collection of inflammatory cells than that associated with the Vicryl mesh. Of the 4 fat-grafted zones that showed good survival, 2 had gross evidence of neural compression. No surgical zone treated with Vicryl mesh exhibited evidence of neural compression. In view of these results, the use of Vicryl mesh at laminectomy sites may be a safer method of limiting postoperative epidural scar formation. 相似文献
992.
Washed human spermatozoa were incubated with different concentrations of bradykinin, des-arg9-bradykinin, and Ile-Ser-bradykinin (T-kinin). Bradykinin significantly increased the total motility of human spermatozoa at a very low concentration (10(-9) M corresponding to about 1 ng/ml). Enhancement of sperm motility was dependent on the bradykinin concentration, and the effect showed saturation at concentrations above 10(-8) M bradykinin (i.e., sperm motility does not increase further with increasing bradykinin concentration). In the concentration range between 10(-11) to 10(-6) M, des-arg9-bradykinin and T-kinin showed no significant change in motility of washed human spermatozoa. The low effective concentration and the saturation of the effect at higher concentrations of kinin makes it probable that the action of bradykinin is mediated by a specific bradykinin receptor. The kinin receptor of human spermatozoa should be of subtype B2 because the specific B1-agonist, des-arg9-bradykinin, showed no influence on sperm motility. 相似文献
993.
Computerized tomographic analysis of orbital hypertelorism repair: spatial relationship of the globe and the bony orbit 总被引:1,自引:0,他引:1
Computerized tomographic scans provide a new means of evaluating the spatial and geometric relationships between the movement of the bony orbit and its soft tissue contents (the globe and extraocular muscles) [1, 12]. Preoperative and postoperative computerized tomographic scans were analyzed in four patients to explore these relationships. Measurement of the changes in distance between the globes correlated most closely with the change in the distance between the lateral orbital walls; resection of medial (inter-orbital) bone provides space into which the globe is translocated. The medial rectus muscle may be bowed across the medial wall osteotomy line, creating a functional shortening of the muscle; this finding may explain the esotropia that is commonly seen after this procedure [2, 3]. These observations should have a direct impact on the understanding and planning of orbital hypertelorism correction. 相似文献
994.
I M Rebeyka R A Axford-Gatley B G Bush P J del Nido D A Mickle A D Romaschin G J Wilson 《The Journal of thoracic and cardiovascular surgery》1990,99(3):475-483
The production and prevention of calcium paradox injury in myocardium was studied in a canine model of cardiopulmonary bypass with multidose, moderately hypothermic, crystalloid cardioplegic solution. During 4 1/2 hours of global ischemia, three groups of six dogs each received one of three histidine-buffered cardioplegic solutions (500 ml initially and 250 ml every 30 minutes) at 27 degrees C. Group 1 cardioplegic solution was calcium free, group 2 solution contained a trace amount of calcium chloride (70 mumols /L), and group 3 cardioplegic solution was calcium free but contained diltiazem (150 micrograms/kg body weight). Left ventricular function measured as percent control of developed pressure revealed significantly greater (p less than 0.05) recovery in groups 2 and 3. Triphenyltetrazolium chloride staining showed 35% +/- 9% (mean +/- standard error) of heart mass necrosis in group 1 versus 0% and 0.5% +/- 0.4% in groups 2 and 3, respectively (p less than 0.001). Electron microscopy revealed ultrastructural changes characteristic of calcium paradox injury in group 1 myocardium. Calcium paradox injury was produced in an in vivo model of global myocardial ischemia and multidose cardioplegia despite moderate hypothermia and non-coronary collateral flow. The addition of either trace levels of calcium or diltiazem to the cardioplegic solution was effective in preventing this injury. 相似文献
995.
S Prescott M A Hadi R A Elton A W Ritchie G C Foubister J C Gould T B Hargreave 《British journal of urology》1990,66(5):509-514
Two different regimens of cephalosporin antibiotic prophylaxis were compared with antiseptic lubricating jelly to try to prevent infection and complications in 196 men after prostatic surgery. Pre-operative urine was cultured and prostatic chips (170 cases) were also cultured to define the source of any infection. The use of antibiotics was associated with a reduced risk of postoperative bacteriuria. No serious complications occurred, although 1 patient in the antiseptic treated group developed rigors; 79 of 170 patients (46%) had positive prostatic chip cultures, of whom 74 had sterile pre-operative urine. There was no association between the result of chip culture and the presence of a pre-operative catheter. Culture positive patients had an increased risk of post-operative urine infection, although the same organism was found in the prostate and urine in only 36% of cases of post-operative bacteriuria and in 43 (54%) the organism cultured from the prostate was Staphylococcus albus. This study provides further evidence of the benefit of true prophylactic antibiotic therapy for transurethral prostatic surgery and the prostatic chip data suggest that some of the risk is due to pre-operative contamination of the prostate in the absence of per-operative urinary infection or catheterisation. 相似文献
996.
The treatment of unstable forearm fractures in children remains a challenging and controversial subject. There are times when more rigid fixation is needed to obtain and maintain fracture reduction. Open reduction/internal fixation or intramedullary nailing can be avoided by the use of the technique of pins and plaster. This study reviewed 20 forearm fractures treated between 1978 and 1984. All fractures healed uneventfully in satisfactory alignment. No complications were encountered. We conclude that the method of pins and plaster is a safe and reliable method to treat unstable pediatric forearm fractures. 相似文献
997.
The importance of intraoperative cholangiography during laparoscopic cholecystectomy 总被引:4,自引:0,他引:4
E H Phillips G Berci B Carroll L Daykhovsky J Sackier M Paz-Partlow 《The American surgeon》1990,56(12):792-795
Laparoscopic cholecystectomy (LC) using electrocoagulation was successfully performed in 56 out of 58 selected patients. Cholangiography was performed in 53 patients. Six patients had common duct stones; five were unsuspected preoperatively. After the gallbladder was removed, three patients underwent open common duct exploration. In another five cases, anatomical anomalies were discovered. Cholangiography performed via the cystic duct before any structures are divided can prevent the most serious complication--common duct injury. Cholangiography should be attempted on all patients undergoing LC. 相似文献
998.
To identify and compare the methods of evaluation for suspected traumatic aortic rupture, 1,031 trauma charts from 1983-1989 were reviewed. Fifty-nine patients were evaluated for possible aortic injury. Patients who died before completion of the CT or aortogram were excluded. Widening of the mediastinum on chest x ray was the most frequent indication for follow-up studies. Twenty-five had a CT of the aortic arch alone. No study showed disruption. There were no false negative studies. Thirty patients had only aortography. Twenty-four were read as normal (one false negative). Six were read as positive (one false positive). In four, both studies were performed (CT/aortography--TP/TP, TN/TN, TP/FN, FP/FP). (FP = False Positive, TP = True Positive, FN = False Negative, TN = True Negative.) Six received surgical repair of the aortic injury (one death). In this experience, CT was used successfully as a screening tool for aortic disruption. It was highly sensitive in recognizing aortic injuries when present (100% vs. 75% for aortography) and in most cases did not require aortographic verification. False positive rates were comparable (CT = 3.8%, aortography = 7.7%). Specificity was also comparable (CT = 96%, aortography = 92%). Overall, four aortograms were inaccurate while only one CT was inaccurate. We recommend the use of CT for the evaluation of widened mediastinum in the stable patient. 相似文献
999.
A postoperative analysis of the patient''s view of anaesthesia in a Netherlands'' teaching hospital 总被引:7,自引:0,他引:7
A postoperative questionnaire was used in 129 patients who had undergone a wide range of surgical procedures in order to investigate their personal experience of anaesthesia. The most frequent complaints were of feeling cold on waking up, sore throat, vomiting and muscle pains, all of which are capable of reduction by a change in anaesthetic technique. The total number of patients who had one or more complaints was 107 (82.9%). More than a third of the patients were afraid of the anaesthetic, as distinct from the operation. Most had received a pre-operative visit from the anaesthetist which was greatly appreciated. A few patients believed they could have been better informed of possible sequelae. More than 30% were not visited by the surgeon before the operation. A routine postoperative interview, using a preformulated questionnaire, is a good way to assess and maintain a high quality of anaesthesia. 相似文献
1000.
G R Seabrook D Karp D D Schmitt D F Bandyk J B Towne 《American journal of surgery》1990,160(5):501-505
Lifetime anticoagulation has become a therapeutic option for surgical patients with hypercoagulable states or prosthetic arterial bypass grafts. However, physicians may not achieve optimal anticoagulation or may attempt to limit the length of the therapy period because of the perceived morbidity from hemorrhagic complications of Coumadin therapy. A protocol for anticoagulant therapy monitored and regulated by a vascular nurse-clinician was reviewed. Coumadin was prescribed for 1,891 patient-months to 93 patients to maintain their prothrombin time 1.5 to 2 times control (range: 18 to 24 seconds). The mean (+/- SD) prothrombin time for the study population was 19.8 +/- 1.8 seconds. During follow-up, 472 (14%) of 3,479 prothrombin times measured were below the therapeutic range (n = 232) or prolonged (n = 240), prompting an adjustment in the Coumadin dose in 82 (88%) patients. Four patients developed recurrent vascular graft thrombosis while receiving anticoagulation. There were 6 major and 11 minor hemorrhagic complications. Patients with a chronic risk for arterial or venous thrombosis can have out-patient anticoagulant therapy administered at optimal intensity and regulated safely with a low incidence of hemorrhagic and thrombotic events. 相似文献