全文获取类型
收费全文 | 1555篇 |
免费 | 161篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 19篇 |
妇产科学 | 21篇 |
基础医学 | 206篇 |
口腔科学 | 69篇 |
临床医学 | 179篇 |
内科学 | 278篇 |
皮肤病学 | 17篇 |
神经病学 | 160篇 |
特种医学 | 106篇 |
外科学 | 199篇 |
综合类 | 37篇 |
一般理论 | 2篇 |
预防医学 | 174篇 |
眼科学 | 37篇 |
药学 | 131篇 |
中国医学 | 1篇 |
肿瘤学 | 60篇 |
出版年
2021年 | 19篇 |
2020年 | 15篇 |
2019年 | 18篇 |
2018年 | 27篇 |
2017年 | 19篇 |
2016年 | 19篇 |
2015年 | 20篇 |
2014年 | 36篇 |
2013年 | 37篇 |
2012年 | 58篇 |
2011年 | 67篇 |
2010年 | 41篇 |
2009年 | 33篇 |
2008年 | 39篇 |
2007年 | 87篇 |
2006年 | 79篇 |
2005年 | 71篇 |
2004年 | 53篇 |
2003年 | 58篇 |
2002年 | 47篇 |
2001年 | 64篇 |
2000年 | 61篇 |
1999年 | 43篇 |
1998年 | 14篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 12篇 |
1992年 | 48篇 |
1991年 | 44篇 |
1990年 | 26篇 |
1989年 | 31篇 |
1988年 | 34篇 |
1987年 | 40篇 |
1986年 | 33篇 |
1985年 | 32篇 |
1984年 | 14篇 |
1983年 | 24篇 |
1982年 | 16篇 |
1981年 | 18篇 |
1980年 | 14篇 |
1979年 | 24篇 |
1978年 | 20篇 |
1974年 | 17篇 |
1973年 | 18篇 |
1972年 | 25篇 |
1971年 | 22篇 |
1970年 | 12篇 |
1966年 | 15篇 |
排序方式: 共有1717条查询结果,搜索用时 15 毫秒
81.
An enzyme is present in extracts of rabbit alveolar macrophage which can catalyze the reaction of creatine phosphate with adenosine diphosphate to form adenosine triphosphate and creatine. The enzyme is moderately activated by reduced glutathione, has a pH optimum between pH 6.5 and 7.0, and shows an absolute requirement for Mg(2+). The K(m) for creatine phosphate is approximately 3.6 mm while the K(m) for adenosine diphosphate is about 1.1 mm. The enzyme may play a role in the energy balance of the cell by creating a reserve of energy in the form of creatine phosphate. 相似文献
82.
P W Burvill M G McCall N S Stenhouse T L Woodings 《The Australian and New Zealand journal of psychiatry》1982,16(3):179-184
Australian data pertaining to Suicide and Accidental Deaths (I.C.D.7) for the years 1962-69 are compared with those for suicide, undetermined deaths and accidental deaths (I.C.D.8) for 1968-71, specific for country of birth. The data strongly suggest that deaths classified as 'undetermined' after the introduction of that I.C.D. category in 1968, had been classified as accidental prior to that data, especially deaths from poisoning. There was some differential between the Australian and U.K. born and the European born. It was estimated that Australian suicide rates are possibly underestimated by 5-10% for males, and 10-20% for females by categorising some deaths from poisoning as being undetermined or accidental. 相似文献
83.
K J Cullen M G McCall N S Stenhouse T A Welborn 《The Medical journal of Australia》1972,1(26):1357-1358
84.
85.
Iain W. McCall Patricia Desai Beryl E. Serjeant Graham R. Serjeant 《American journal of hematology》1977,3(1):15-21
The prevalence of cholelithiasis in Jamaican adults with SS disease was studied by plain abdominal radiograph in 206 patients and by oral cholecystogram in 126 (61%) of these patients. Gallstones were found in 57 (28%) of patients, were more common in females than males, and increased with age and hemolytic rate. The majority of gallstones were visible on the plain abdominal radiograph, only 17% of patients with gallstones having only radiolucent stones. Nonfunctioning oral cholecystograms were common (10%) in agreement with observations by previous workers. Gallstones were noted in the common bile duct in 2 patients. In general there was no clear relationship between the presence of cholelithiasis and clinical symptomatology. Complications, such as pancreatitis and malignant change in the gall bladder, recognized to be associated with cholelithiasis in the general population, have not been clearly related to cholelithiasis in SS disease. More information is needed before a logical policy can be evolved for surgical intervention in cholelithiasis in SS disease. 相似文献
86.
87.
Golub ET Bareta JC Mehta SH McCall LD Vlahov D Strathdee SA 《Substance use & misuse》2005,40(12):1751-1764
Because multi-person syringe use is the most common vehicle for HIV and hepatitis C virus transmission among injection drug users (IDUs), safe sources of sterile syringes and safe methods of disposal are necessary to curb these epidemics. We examined syringe acquisition and disposal in a cohort of IDUs in Baltimore. Between January 1, 1998 and December 31, 2001, 1034 participants reported on syringe acquisition at 3492 visits, and 953 reported on disposal at 2569 visits. Participants were 69.9% male, 93.9% African-American, and median age was 44. Syringes were acquired exclusively from unsafe sources at 32.3% of visits, while exclusively unsafe disposal was reported at 59.3% of visits. Significant correlates of unsafe acquisition were: attending shooting galleries, anonymous sex, sharing needles, smoking crack, and emergency room visits. Significant correlates of unsafe disposal were: injecting speedball, no methadone treatment, acquiring safely, and frequent injection. Having a primary source of medical care was associated with safe acquisition, but unsafe disposal. IDUs continue to acquire safely but dispose unsafely, especially among those with a primary source of care; this suggests that messages about safe disposal are not being disseminated as widely as those about acquisition. These data suggest the need for a more active program involving pharmacists, an expanded syringe access program, and better efforts to enhance safe disposal. 相似文献
88.
Extracorporeal shock wave therapy without local anesthesia for chronic lateral epicondylitis 总被引:1,自引:0,他引:1
BACKGROUND: The use of extracorporeal shock wave therapy for the treatment of lateral epicondylitis is controversial. The purpose of this study was to evaluate the use of extracorporeal shock wave therapy without local anesthesia to treat chronic lateral epicondylitis. METHODS: One hundred and fourteen patients with a minimum six-month history of lateral epicondylitis that was unresponsive to conventional therapy were randomized into double-blind active treatment and placebo groups. The protocol consisted of three weekly treatments of either low-dose shock wave therapy without anesthetic or a sham treatment. Patients had a physical examination, including provocation testing and dynamometry, at one, four, eight, and twelve weeks and at six and twelve months after treatment. Radiographs, laboratory studies, and electrocardiograms were also evaluated prior to participation and at twelve weeks. A visual analog scale was used to evaluate pain, and an upper extremity functional scale was used to assess function. Crossover to active treatment was initiated for nonresponsive patients who had received the placebo and met the inclusion criteria after twelve weeks. RESULTS: A total of 108 of the 114 randomized patients completed all treatments and the twelve weeks of follow-up required by the protocol. Sixty-one patients completed one year of follow-up, whereas thirty-four patients crossed over to receive active treatment. A significant difference (p = 0.001) in pain reduction was observed at twelve weeks in the intent-to-treat cohort, with an improvement in the pain score of at least 50% seen in 61% (thirty-four) of the fifty-six patients in the active treatment group who were treated according to protocol compared with 29% (seventeen) of the fifty-eight subjects in the placebo group. This improvement persisted in those followed to one year. Functional activity scores, activity-specific evaluation, and the overall impression of the disease state all showed significant improvement as well (p < 0.05). Crossover patients also showed significant improvement after twelve weeks of active treatment, with 56% (nineteen of thirty-four) achieving an improvement in the pain score of at least 50% (p < 0.0001). CONCLUSIONS: These results demonstrate that low-dose shock wave therapy without anesthetic is a safe and effective treatment for chronic lateral epicondylitis. 相似文献
89.
Is routine placement of surgical drains necessary after elective hepatectomy? Results from a single institution 总被引:2,自引:0,他引:2
Ali?Aldameh John?L.?McCall Jonathan?B.?KoeaEmail author 《Journal of gastrointestinal surgery》2005,9(5):667-671
Routine drainage is no longer used after many major abdominal procedures. However, the role of routine surgical drainage after
hepatic resection is unclear. Of the two randomized trials published, one concluded drainage is unnecessary after hepatectomy,
and another concluded it could be used after major resections only. Between January 1999 and December 2003, 211 elective hepatic
resections were performed by two surgeons at Auckland Hospital. Drains were used routinely by one surgeon (n = 126), while
another routinely did not drain (n =85). Patients undergoing a biliary reconstruction were not included in this analysis.
Patient and clinical data were recorded prospectively, and no outcome analyses were performed until 2004. The demographic
features were similar between the drained and nondrained groups. There were no differences in length of hospital stay (no
drain, 7 +- 0.8 days; drain, 7 +- 0.9 days: P = not signi.cant [NS]), in mortality (no drain, 1.2%; drain, 1.6%: P =NS), biliary flstula (no drain, zero cases; drain, two cases: P = NS), or overall complication rate (no drain, 50.5%; drain, 54.7%: P =NS). Both groups had similar rates of postoperative collection (no drain, four patients [5%]; drain, five patients [4%]:
P =NS), and there was no difference in the use of percutaneous drainage of collections between the groups (no drain, four patients
[5%]; drain, two patients [2%]: P =NS). Multivariate analysis showed that intraoperative blood loss of 2000 ml or greater (relative risk [RR], 1.57; 95% confidence
interval [CI], 1.39-1.75; P < 0.01), number of segments resected (RR, 1.4; 95% CI, 1.21-1.89; P < 0.01), and presence of steatosis/.brosis or cirrhosis (RR, 1.6; 95% CI, 1.01-2.1; P <0.05) to be predictive of postoperative complications. The presence of a surgical drain was not predictive of complications.
Routine surgical drainage after elective hepatectomy is not necessary.
Presented in part at the Forty-Fifth Annual Meeting of The Society for Surgery of the Alimentary Tract, New Orleans, Louisiana,
May 15–19, 2004. 相似文献
90.