全文获取类型
收费全文 | 5530篇 |
免费 | 222篇 |
国内免费 | 85篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 32篇 |
妇产科学 | 610篇 |
基础医学 | 146篇 |
口腔科学 | 60篇 |
临床医学 | 269篇 |
内科学 | 582篇 |
皮肤病学 | 18篇 |
神经病学 | 75篇 |
特种医学 | 202篇 |
外科学 | 2973篇 |
综合类 | 184篇 |
现状与发展 | 1篇 |
预防医学 | 80篇 |
眼科学 | 4篇 |
药学 | 84篇 |
4篇 | |
中国医学 | 4篇 |
肿瘤学 | 433篇 |
出版年
2024年 | 10篇 |
2023年 | 217篇 |
2022年 | 390篇 |
2021年 | 417篇 |
2020年 | 457篇 |
2019年 | 215篇 |
2018年 | 284篇 |
2017年 | 132篇 |
2016年 | 224篇 |
2015年 | 221篇 |
2014年 | 440篇 |
2013年 | 363篇 |
2012年 | 333篇 |
2011年 | 324篇 |
2010年 | 288篇 |
2009年 | 197篇 |
2008年 | 177篇 |
2007年 | 188篇 |
2006年 | 143篇 |
2005年 | 119篇 |
2004年 | 101篇 |
2003年 | 100篇 |
2002年 | 92篇 |
2001年 | 88篇 |
2000年 | 63篇 |
1999年 | 60篇 |
1998年 | 38篇 |
1997年 | 18篇 |
1996年 | 25篇 |
1995年 | 26篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1984年 | 3篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1978年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有5837条查询结果,搜索用时 31 毫秒
31.
32.
《Journal d'obstetrique et gynecologie du Canada》2007,29(10):835-840
BackgroundVirilization in female newborns typically results from congenital adrenal hyperplasia, requiring immediate diagnosis and treatment. We report a rare cause of virilization, maternal pregnancy luteoma, responsible for virilization of both a newborn and the mother. Luteomas are usually asymptomatic tumour-like ovarian lesions of pregnancy that secrete androgens in only 25% of cases. Many female infants born to masculinized mothers will also be virilized.CaseA term infant born with ambiguous genitalia was transferred to a referral centre for investigation, diagnosis, and treatment. Assessment identified Prader II-III genitalia, an elevated serum testosterone level, a normal serum 17-hydroxyprogesterone level, and a normal female karyotype (46,XX). The mother had had virilization from the second trimester and was found to have an elevated serum testosterone level. Pelvic ultrasound assessment in the mother showed a complex right ovarian mass. Laparotomy was performed, and the mass was excised. Histopathology examination confirmed a luteoma.ConclusionHigh maternal serum testosterone levels due to a luteoma can result in virilization in the female newborn. This report emphasizes the need to consider possible underlying maternal pathology in evaluating a virilized female infant. 相似文献
33.
34.
Early laparoscopic cholecystectomy for acute cholecystitis 总被引:4,自引:0,他引:4
Background: The timing of laparoscopic cholecystectomy for acute cholecystitis remains controversial.
Methods: One hundred ninety-four patients with acute cholecystitis were reviewed. The conversion rates for the various number of days
of symptoms before surgery were analyzed. The conversion rate dramatically increased from 3.6% for those patients with 4 days
of symptoms to 26% for those patients with 5 days of symptoms. The mean number of days of symptoms prior to surgery in those
patients who underwent successful laparoscopic cholecystectomy was 4.1 as compared to 8.0 in those patients who required open
cholecystectomy (p < 0.0001). Based on this data the patients were divided into two groups. Group 1 consisted of 109 patients who underwent
laparoscopic cholecystectomy within 4 days of onset of symptoms and group 2 consisted of 85 patients who underwent laparoscopic
cholecystectomy after more than 4 days following onset of symptoms.
Results: The conversion rate from laparoscopic to open cholecystectomy was 15%. The conversion rate for group 1 was 1.8% as compared
to 31.7% for group 2 (p < 0.0001). Indications for conversion were inability to identify the anatomy secondary to inflammatory adhesions (68%), cholecystoduodenal
fistula (18%), and bleeding (14%). The major complication rate for group 1 was 2.7% as compared to 13% for group 2 (p= 0.007). The mortality rate for all patients with attempted laparoscopic cholecystectomy for acute cholecystitis was 1.5%.
The average procedure time for group 1 was 100 ± 37 min vs 120 ± 55 min in group 2. The average number of postoperative hospital
days in group 1 was 5.5 ± 2.7 days as compared to 10.8 ± 2.7 days in group 2.
Conclusions: We advocate early laparoscopic cholecystectomy within 4 days of onset of symptoms to decrease major complications and conversion
rates. This decreased conversion rate results in decreased length of procedure and hospital stay.
Received: 28 March 1996/Accepted: 12 September 1996 相似文献
35.
Laparoscopic trans-cystic-duct common-bile-duct exploration 总被引:1,自引:0,他引:1
One thousand seventy-one consecutive laparoscopic cholecystectomies were performed. Routine cholangiography was employed with a 99% success rate. One hundred thirty patients were found to have common duct stones (CBDS). In 48 (37%) patients they were unsuspected. One hundred eleven patients underwent attempted trans-cystic-duct extraction techniques (TCD-CBDE). One hundred three (93%) were successful. The following techniques were employed: 101—biliary endoscopy, 23—ampullary balloon dilation, 2—fluoroscopic basket retrieval.The average operative time was 136 min. The average postsurgical stay was 3.7 days. There were 19 (17%) complications—6 (5%) major. There were 4 retained stones (2 intentional) and 1 death. Patients over 65 years of age had more complications and patients with unsuspected CBDS under 65 years of age had the fewest.TCD-CBDE is a safe, effective way to extract common duct calculi. Endoscopy and basket stone retrieval was the primary technique employed.Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Nashville, Tennessee, USA, 18–19 April 1994 相似文献
36.
37.
38.
Acoustic emission from renal calculi irradiated by a pulsed dye laser was observed in vivo and investigated in vitro. A number
of acoustic frequency spectra were recorded from laser exposure of ureteric calculi, calcified arterial wall and bladder tissue.
Although differences were observed between spectra, these did not depend on target material. Investigations with model targets
suggested that variations in acoustic emission were caused by fluctuations in the strength of the laser plasma, due to changes
in the local surface absorption of laser light, and by alterations in the relative orientation of laser fibre, target and
transducer. Interaction between lasers and stones is reviewed and discussed. 相似文献
39.
Effects of gastric bypass procedures on bone mineral density,calcium, parathyroid hormone,and vitamin d 总被引:2,自引:0,他引:2
Jason M. Johnson James W. Maher Isaac Samuel Deborah Heitshusen Cornelius Doherty Robert W. Downs 《Journal of gastrointestinal surgery》2005,9(8):1106-1111
Weight loss after gastric bypass procedures has been well studied, but the long-term metabolic sequelae are not known. Data
on bone mineral density (BMD), calcium, parathyroid hormone, and vitamin D were collected preoperatively and at yearly intervals
after gastric bypass procedures. A total of 230 patients underwent preoperative BMD scans. Fifteen patients were osteopenic
preoperatively, and three patients subsequently developed osteopenia postoperatively within the first year. No patient had
or developed osteoporosis. At 1 year, total forearm BMD decreased by 0.55% (n = 91; P = .03) and radius BMD had increased overall by 1.85% (n = 23; P = .008); both total hip and lumbar spine BMD decreased by
9.27% (n = 22; P < .001) and 4.53% (n = 31; P < .001), respectively. By the second postoperative year, BMD in the total forearm had decreased an additional 3.62% (n =
14; P<.001), whereas radius BMD remained unchanged. Although total hip and lumbar spine BMD significantly decreased at 1 year,
by year 2 both total hip and lumbar spine BMD only slightly decreased and were not significantly different from before the
operation. Serum calcium decreased from 9.8 mg/dL to 9.2 during the first year (not significant [NS]) and then to 8.8 (NS)
by the second year. Parathyroid hormone increased from 59.7 pg/mL (nl 10-65 pg/mL) preoperatively to 63.1 during year 1 (NS)
and continued to increase to 64.7 by year 2 (NS). No difference was noted among levels of 25-hydroxy vitamin D preoperatively
(25.2 ng/mL; nl 10-65 ng/mL), at 1 year (34.4), and at 2 years (35.4). Our data indicate that bone loss is highest in the
first year after gastric bypass with stabilization, and that, in some cases, there is an increase in bone density after the
first year.
Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18,
2005 (oral presentation). 相似文献
40.
Daniel W. Birch 《Canadian journal of surgery》2007,50(3):195-201
INTRODUCTION: Laparoscopic repair of ventral and incisional hernias (LVIHRs) is feasible; however, many facets of this procedure remain poorly defined. The indications, essential technical features and postoperative management should be standardized to optimize outcomes and facilitate training in this promising approach to incisional hernia repair. METHODS: All patients referred to one surgeon at a tertiary care centre for LVIHR from 1999 to 2004 were analyzed. Patient records were analyzed and perioperative outcomes were documented. RESULTS: Of the 69 patients who were referred for management of incisional hernia, 64 underwent LVIHR. The mean age of patients selected for surgery was 61.4 years (28% of patients over age 70 years); their mean body mass index (BMI) was 32.8 kg/m2 and mean American Association of Anaesthetists (ASA) score was 2.5 (52% of patients had an ASA score equal to 3). The mean operating time was 130.7 minutes for a mean abdominal wall defect of 123.9 cm2 and a mean prosthetic mesh size of 344 cm2. Patients with recurrent incisional hernias and previous prosthetic mesh were the most challenging, with a mean BMI of 39 kg/m2, mean operating time of 191 minutes, mean defect of 224 cm2 and mean prosthetic mesh size of 508 cm2. One patient was converted to open surgery and, in 2 patients, small bowel injuries were repaired laparoscopically without adverse sequelae. The mean length of stay was 4.5 days (median 3.0 d). Postoperatively, 78% of patients developed seromas within the residual hernia sac. All seromas were managed nonoperatively; one-half resolved by 7 weeks, and larger seromas persisted for up to 24 weeks. There was an 18.7% rate of minor complications and a 3.1% rate of major complications (no deaths). After a mean follow-up of 7.7 months, 2 recurrent hernias (3.1%) were identified in patients with multiple previous open mesh repairs. CONCLUSION: Although LVIHR may be challenging, it has the potential to be considered a primary approach for most ventral and incisional hernias, regardless of patient status or hernia complexity. 相似文献