全文获取类型
收费全文 | 8493篇 |
免费 | 632篇 |
国内免费 | 291篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 137篇 |
妇产科学 | 87篇 |
基础医学 | 1190篇 |
口腔科学 | 192篇 |
临床医学 | 996篇 |
内科学 | 1022篇 |
皮肤病学 | 116篇 |
神经病学 | 521篇 |
特种医学 | 500篇 |
外国民族医学 | 2篇 |
外科学 | 953篇 |
综合类 | 1398篇 |
预防医学 | 396篇 |
眼科学 | 112篇 |
药学 | 854篇 |
4篇 | |
中国医学 | 318篇 |
肿瘤学 | 561篇 |
出版年
2024年 | 31篇 |
2023年 | 136篇 |
2022年 | 264篇 |
2021年 | 395篇 |
2020年 | 301篇 |
2019年 | 271篇 |
2018年 | 216篇 |
2017年 | 254篇 |
2016年 | 268篇 |
2015年 | 285篇 |
2014年 | 528篇 |
2013年 | 490篇 |
2012年 | 468篇 |
2011年 | 517篇 |
2010年 | 443篇 |
2009年 | 421篇 |
2008年 | 380篇 |
2007年 | 415篇 |
2006年 | 393篇 |
2005年 | 325篇 |
2004年 | 303篇 |
2003年 | 294篇 |
2002年 | 246篇 |
2001年 | 218篇 |
2000年 | 181篇 |
1999年 | 169篇 |
1998年 | 141篇 |
1997年 | 121篇 |
1996年 | 98篇 |
1995年 | 103篇 |
1994年 | 73篇 |
1993年 | 67篇 |
1992年 | 65篇 |
1991年 | 65篇 |
1990年 | 56篇 |
1989年 | 40篇 |
1988年 | 50篇 |
1987年 | 54篇 |
1986年 | 41篇 |
1985年 | 47篇 |
1984年 | 29篇 |
1983年 | 24篇 |
1982年 | 25篇 |
1981年 | 23篇 |
1980年 | 19篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1974年 | 7篇 |
排序方式: 共有9416条查询结果,搜索用时 31 毫秒
21.
22.
Total anorectal reconstruction with a double dynamic graciloplasty after abdominoperineal reconstruction for low rectal cancer 总被引:7,自引:3,他引:4
Bastiaan P. Geerdes M.D. Frans A. N. Zoetmulder M.D. Ph.D Erik Heineman M.D. Ph.D. Egbert J. Vos M.Sc. Mart -Jan Rongen M.D. Cor G. M. I. Baeten M.D. Ph.D. 《Diseases of the colon and rectum》1997,40(6):698-705
PURPOSE: Total anorectal reconstruction with a double dynamic graciloplasty was performed after abdominoperineal reconstruction
(APR) for low rectal cancer. In four patients an additional pouch was constructed to improve neorectal motility and capacity.
The aim of this study was to evaluate the results in the first 20 patients and to report on the preliminary results of patients
with an additional pouch. METHODS: Twenty patients with a mean age of 52 (range, 25–71) years and a rectal tumor at a mean
of 3 (range, 0–5) cm from the anal verge were treated. In 14 patients the Miles resection, colon pull-through, and construction
of a neosphincter were performed in one session. Six patients had the double graciloplasty at an average of 4.1 (range, 1.1–8.8)
years after APR. In four patients a pouch was constructed with an isolated segment of distal ileum. RESULTS: After a mean
follow-up of 24 (range, 1–60) months after APR, none of the patients developed local recurrence, whereas four patients developed
distant metastasis. Fifteen of 20 patients were available for evaluation, and 5 patients were still in training. Of these
15 patients, 8 patients were continent (53 percent), 2 patients were incontinent, and in 5 patients the perineal stoma was
converted to an abdominal stoma. Failures were attributable to necrosis of the colon stump (n=2) and incontinence (n=3). At
26 weeks mean resting pressure was 44 (standard deviation (SD), 28) mmHg, and mean pressure during stimulation was 90 (SD,
46) mmHg at a mean of 35 (SD, 1.2) volts at 52 weeks. Mean defecation frequency was three times per day (range, 1–5). Of the
eight patients who were continent, six used daily enemas. Mean time to postpone defecation was 11 (range, 0–30) minutes. CONCLUSION:
In experienced hands, the double dynamic graciloplasty is an oncologically safe procedure that can have an acceptable functional
outcome in a well-selected group of patients. However, to improve the outcome, further modifications will be necessary. So
far, the addition of a pouch has not resulted in improved outcome.
Supported by the Profileringsfonds of the Maastricht University Hospital, The Netherlands, and by the Stichting Fondsenwervingsactie
Volksgezondheid, Amsterdam, The Netherlands.
Read in part at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1995. 相似文献
23.
目的 探讨弥漫性大B细胞淋巴瘤(DLBCL)临床和病理组织学特征以及免疫组化特异性抗体及IgH基因重排检测在其诊断和鉴别诊断中的价值。方法 收集30例弥漫性大B细胞淋巴瘤及其临床资料,用免疫组化孓P法标记LCA,CD20,CD79a,CD30及bcl-2抗体和用PCR方法检测15例IgH基因重排。结果 70%(21/30)弥漫性大B细胞淋巴瘤发病年龄在40~70岁,淋巴结内外都可累及。组织病理学:中心母细胞淋巴瘤占83.3%(25/30),免疫母细胞淋巴瘤占3.3%(1/30),间变性大细胞淋巴瘤占6.7%(2/30),及富于T细胞B细胞淋巴瘤占6.7%(2/30)。免疫标记LCA均表现阳性,CD20、CD79a、CD30、bcl-2表达率分别为86.7%(26/30),93.3%(28/30),6.7%(2/30),20%(6/30)。15例DLBCL中IgH基因重排阳性为66.7%(10/15)。结论 弥漫性大B细胞淋巴瘤是一组异质性肿瘤,必须结合其组织病理学形态和特异抗体的免疫组化检测,对一些疑难病例需做IgH基因重排检测以进行诊断和鉴别诊断。 相似文献
24.
25.
Ureteral hernia is uncommon and usually misdiagnosed. From an anatomic point of view, we can distinguish between two uretero-inguinal
hernias: intraperitoneal and extraperitoneal. Ureter inguinal hernias are nearly always indirect. This kind of hernia can
include the ureter alone or, frequently, other abdominal sliding organs within the hernia sac (bladder, bowel tracts, etc.).
Kidneys and urinary tracts present normal anatomic conformation, although renal ptosis may be found. As of July 2004, 139
cases of ureteral hernia had been described in the literature. Here we report a case of inguino-scrotal herniation of double
district ureter and review the current literature to analyze the main clinical characteristics of this pathology and to establish
pitfalls. 相似文献
26.
Summary: To develop a method for identification of differential gene expression between different cell populations, several convenient techniques of molecular biology, including subtractive hybridization, suppression PCR, T/A cloning and sequencing, were used to identify genes expressed differentially in CD45^- and CD45^- cells isolated from U266 cell line of multiple myeloma. Our results showed that the levels of abundant genes scale down 20 times through subtractive hybridization.Plasmid DNA from CD45^- cell clones was hybridized with forward or backward cDNA probes synthesized from CD45^- and CD45 cells, respectively. A few of differentially expressed genes reconfirmed by RT-PCR were identified from 500 expressed clones of CD45^- cells. It is concluded that a strategy for gene expression identification developed from conventional molecular biological methods can be used in different laboratories. 相似文献
27.
左双腔支气管导管管端位置与吸气峰压变化的关系 总被引:13,自引:3,他引:10
目的 观测无隆突钩双腔支气管导管(DLT)管端位置与吸气峰压(Ppeak)以及肺顺应性环形状改变的关系,探讨用Ppeak和顺应性环的变化评估DLT管端位置的可行性。方法 拟行右侧剖胸手术的成年患者32例,静脉诱导后插入左Mallinckrodt DLT,吸入氧化亚氮和地氟醚维持麻醉。按纤维支气管镜(FOB)确认DLT管端位置和通气方式将观测过程分为四个阶段:第一阶段(S1),管端位置正确的双肺通气;第二阶段(S2),管端位置正确的左侧单肺通气;第三阶段(S3),管端插入左下支气管(置管过深)的左侧单肺通气;第四阶段(S。),管端处在左支气管开口(置管偏浅)的左侧单肺通气。每阶段均机械通气15min。结果 回归方程预计插管深度与FOB检查符合者占71.9%。S2时Ppeak值比S1时增加50.8%,肺顺应性(Cdyn)值减少36.2%;S3时Ppeak值比S1时增加87.4%,Cdyn值减少56.8%。PV环曲线斜率向右明显移位,环体显著延长。结论 用无隆突钩DLT行肺隔离,在无FOB定位的条件时,联合应用听诊法、回归方程预计插管深度、动态监测气道峰压和P-V环的变化综合评估,可提高DLT管端的正确到位率。单肺通气的气道峰压超过双肺通气时的1.65倍,且气道峰压超过25cm H2O.应高度怀疑DLT管端发生过深移位。 相似文献
28.
Peter Jecker Lisa A. Orloff Miriam Wohlfeil Wolf J. Mann 《European archives of oto-rhino-laryngology》2006,263(7):664-667
Chronic polypoid rhinosinusitis (CRS) is a common disease, affecting approximately 16% of the adult population in the US every year. In addition to many well known predisposing factors, an association with reflux disease is hypothesized. Such an association might explain the recurrence of polyposis in the face of improved surgical techniques and postsurgical treatment of CRS. At present it is unclear whether extraesophageal reflux directly injures the sinus mucosa, whether gastroesophageal reflux leads to vagus-mediated neuroinflammatory changes, or whether both mechanisms occur separately or simultaneously. In patients suffering from recurrent CRS (n=20) and healthy volunteers (n=20), ambulatory 24 h two channel pH testing was performed. The number of reflux events, the fraction of the total time during which pH was below 4, and the reflux area index (RAI) were determined in the esophagus as well as in the hypopharynx. Patients with recurrent CRS had significantly more reflux events in the esophagus and the fraction of pH<4 and the RAI were increased up to 10-fold compared to healthy volunteers. In contrast to the esophagus, these differences were not observed in the hypopharynx. Recurrent CRS is often associated with GERD but not with EER. Recurrent disease or prolonged recovery after surgery should raise the suspicion of reflux disease as a possible triggering factor. Because GERD itself cannot be diagnosed by laryngoscopy, and because of the subjectivity of symptoms such as heartburn, the otolaryngologist should consider double-probe pH testing as the diagnostic procedure of choice. 相似文献
29.
30.