全文获取类型
收费全文 | 175385篇 |
免费 | 1000篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 1135篇 |
儿科学 | 6640篇 |
妇产科学 | 3103篇 |
基础医学 | 16473篇 |
口腔科学 | 1609篇 |
临床医学 | 12350篇 |
内科学 | 30729篇 |
皮肤病学 | 687篇 |
神经病学 | 16461篇 |
特种医学 | 8901篇 |
外科学 | 28723篇 |
综合类 | 2308篇 |
一般理论 | 3篇 |
预防医学 | 18113篇 |
眼科学 | 2732篇 |
药学 | 9433篇 |
中国医学 | 624篇 |
肿瘤学 | 16368篇 |
出版年
2022年 | 20篇 |
2021年 | 29篇 |
2020年 | 24篇 |
2019年 | 44篇 |
2018年 | 21941篇 |
2017年 | 17384篇 |
2016年 | 19531篇 |
2015年 | 911篇 |
2014年 | 821篇 |
2013年 | 772篇 |
2012年 | 6961篇 |
2011年 | 20997篇 |
2010年 | 18793篇 |
2009年 | 11509篇 |
2008年 | 19488篇 |
2007年 | 21693篇 |
2006年 | 534篇 |
2005年 | 2147篇 |
2004年 | 3354篇 |
2003年 | 4326篇 |
2002年 | 2461篇 |
2001年 | 267篇 |
2000年 | 415篇 |
1999年 | 161篇 |
1998年 | 207篇 |
1997年 | 206篇 |
1996年 | 93篇 |
1995年 | 105篇 |
1994年 | 100篇 |
1993年 | 60篇 |
1992年 | 36篇 |
1991年 | 87篇 |
1990年 | 122篇 |
1989年 | 74篇 |
1988年 | 55篇 |
1987年 | 41篇 |
1986年 | 23篇 |
1985年 | 29篇 |
1984年 | 21篇 |
1983年 | 22篇 |
1982年 | 30篇 |
1980年 | 43篇 |
1969年 | 20篇 |
1939年 | 20篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
111.
Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis
Barbara Bordini Susanna Stea Manuela De Clerico Sergio Strazzari Antonio Sasdelli Aldo Toni 《BMC musculoskeletal disorders》2007,8(1):69
Background
Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure. 相似文献112.
F. Specchiulli R. Gabrieli D. Borsetti V. Di Carlo 《Journal of orthopaedics and traumatology》2007,8(3):123-127
We examined the clinical and radiographic results of 93 patients affected by knee arthritis or osteonecrosis subjected to
unilateral cementless mobile-bearing total knee arthroplasty with the LCS prothesis (Depuy/Johnson & Johnson). The mean follow-up
was 9.5 years (range, 7–12 years). Clinical evaluation was performed using the Knee Society rating system, while radiographic
evaluation was done according to the Knee Society roentgenographic system. At the latest follow-up, the mean knee score was
87 points: the functional score improved from 40 to 90. Radiolucent lines were small and not progressive. The implant survival
at 12 years was 88%. Six knees (7%) required revision for implant-related problems. We conclude that the mobile-bearing prosthesis
is a successful device even at long-term follow-up. 相似文献
113.
Michael T Fitch David E Manthey Henderson D McGinnis Bret A Nicks Manoj Pariyadath 《BMC medical education》2008,8(1):38
Background
Skin and soft tissue infections are increasingly prevalent clinical problems, and it is important for health care practitioners to be well trained in how to treat skin abscesses. A realistic model of abscess incision and drainage will allow trainees to learn and practice this basic physician procedure. 相似文献114.
Man Bok Jeong Kristina Narfström Shin Ae Park Je Min Chae Kang Moon Seo 《Documenta ophthalmologica. Advances in ophthalmology》2009,119(2):79-88
The objective of this study is to compare the effects of three different anesthetic combinations on the electroretinogram
in the same animals under similar laboratory conditions. Thiopental–isoflurane (TI), medetomidine–ketamine (MK), and xylazine–ketamine
(XK) were used on each of 12 healthy miniature schnauzer dogs (MS) with a period of at least 3 weeks in between subsequent
anesthesia protocols, using the Dog Standard Protocol. The scotopic ERGs consisted of scotopic low stimulus strength (S) responses
designated S1, S2, S3, S4, and S5, at 1, 5, 10, 15, and 20 min after dark adaptation, respectively, and scotopic standard
stimulus strength (S-ST) responses. The photopic ERGs consisted of a photopic single flash (P) response and 31 Hz flicker
(P-FL) responses. For S-ST (2.5 cd s/m2), the amplitude of the a-wave using TI was significantly lower than that using MK (adjusted P = 0.05) and XK (adjusted P = 0.03), and the implicit time of the a-wave was significantly shorter than that using MK (adjusted P = 0.04). For P (2.5 cd s/m2), the amplitude of the b-wave using XK was significantly higher than that using MK (adjusted P = 0.01). The implicit times of the b-wave using TI was significantly longer and shorter than that of MK for S1, S2 and P-FL
and for S4 and S-ST, respectively, and than that of XK for S2 and P-FL and for S5 and S-ST, respectively. The results of the
present study showed that TI affected both the amplitude and the implicit time of the a-wave for S-ST and the implicit time
of the b-wave relatively more so than was the case when using XK or MK. Therefore, it appears that either XK or MK could be
advantageous to use rather than TI for clinical studies. 相似文献
115.
Conclusion We would like to stress that we do not necessarily consider AC for SPECT MPI to be unfeasible or unworthy of scientific pursuit;
indeed, a great deal of creative scientific effort has been poured into this area of investigation over the past 3 decades,
and much of it has contributed to a better understanding of the physics, as well as the clinical aspects, of our field. However,
the great variety of available AC hardware and software “flavors,” the historical pattern of commercial release of insufficiently
validated AC implementations, and the increasingly clouded health care reimbursement horizon may have created an environment
where the envisioned users of the technology have been desensitized and discouraged from expecting it to ever come to fruition
in a standardized, validated, and costeffective form.
It has been reported as recently as 2005 that the “entire base of SPECT cameras has only 5% of systems with attenuation correction.”8
Perhaps the reports of AC’s demise are exaggerated, but it certainly seems as if the people have spoken and, after readying
themselves for the wolf one too many times, have come to the conclusion that “the future (of AC) ain’t what it used to be”
. . .at least not yet. 相似文献
116.
Michelle L. DeOliveira Timothy M. Pawlik Ana L. Gleisner Lia Assumpcaom Gaspar J. Lopes-Filho Michael A. Choti 《Journal of gastrointestinal surgery》2007,11(8):970-976
Survival after resection of colorectal liver metastases has traditionally been associated with clinicopathologic factors.
We sought to investigate whether echogenicity of colorectal liver metastasis as assessed by intraoperative ultrasound (IOUS)
was a prognostic factor after hepatic resection. Prospective data on tumor IOUS appearance were collected in 84 patients who
underwent hepatic resection for colorectal liver metastasis. Images were digitally recorded, blindly reviewed, and scored
for echogenicity (hypo-, iso-, or hyperechoic). The median tumor number was 1 and the median tumor size was 5.0 cm. At the
time of surgery, the IOUS appearance of the colorectal liver metastases were hypoechoic in 35 (41.7%) patients, isoechoic
in 37 (44.0%) patients, and hyperechoic in 12 (14.3%) patients. Traditional clinicopathologic prognostic factors were similarly
distributed among the three echogenicity groups (all p > 0.05). Patients with a hypoechoic lesion had a significantly shorter median survival (30.2 months) compared with patients
who had either an isoechoic (53.2 months) or hyperechoic (42.3 months) lesion (p = 0.005). The 5-year survival after hepatic resection of colorectal liver metastasis was also associated with the echogenic
appearance of the lesion (hypoechoic 14.4 vs isoechoic 37.4 vs hyperechoic 46.2%) (p < 0.05). Intraoperative ultrasound echogenicity should be considered a prognostic factor after hepatic resection of metastatic
colorectal cancer.
This study was presented at the 47th annual meeting of The Society for Surgery of the Alimentary Tract, Los Angeles, CA, USA,
22 May 2006. 相似文献
117.
Alessio Pigazzi Minia Hellan Douglas R. Ewing Benjamin I. Paz Garth H. Ballantyne 《Journal of gastrointestinal surgery》2007,11(6):778-782
Laparoscopic colectomy is a difficult procedure with a long learning curve. We describe in this study our technique for right-
and left-sided laparoscopic medial-to-lateral colectomy. The medial approach involves division of the vascular pedicle first,
followed by mobilization of the mesentery toward the abdominal wall, and finally freeing of the colon along the white line
of Toldt. This approach allows immediate identification of the plane between the mesocolon and the retroperitoneum and renders
the dissection fast and safe. Our series of 50 consecutive laparoscopic colectomies supports this concept. We believe that
surgeons familiar with this technique will have an important tool in their armamentarium to circumvent some of the challenges
of laparoscopic colectomy. 相似文献
118.
Gastroesophageal reflux disease (GERD) is a common disease and can be successfully treated by laparoscopic fundoplication.
This article describes the technique of laparoscopic surgery for GERD with a focus on operative pitfalls. 相似文献
119.
Burkhard H. A. von Rahden Brigitte Stigler Wolfgang Weiß Hubert J. Stein 《Journal of gastrointestinal surgery》2007,11(7):945-947
Management of upper gastrointestinal bleeding because of erosion of vessels by esophageal cancer may be challenging. We present
herein the angiographic images of a 49-year-old patient who was admitted with massive bleeding from a tumor-eroded inferior
thyroid artery. Attempts to control the bleeding by means of flexible endoscopy and insertion of a Sengstaken–Blakemore tube
had failed. The diagnosis was impressively demonstrated by multislice computed tomography with intravenous contrast in the
arterial phase and multiplanar reconstructions (computed tomography angiography) and by digital subtraction angiography. The
bleeding was successfully treated with superselective catheterization and coiling of the eroded vessel. 相似文献
120.
Internal Hernias: Clinical Findings,Management, and Outcomes in 49 Nonbariatric Cases 总被引:1,自引:0,他引:1
Saber Ghiassi Scott Q. Nguyen Celia M. Divino John C. Byrn Avraham Schlager 《Journal of gastrointestinal surgery》2007,11(3):291-295
Internal hernia, the protrusion of a viscus through a peritoneal or mesenteric aperture, is a rare cause of small bowel obstruction.
We report the clinical presentation, surgical management, and outcomes of one of the largest series of nonbariatric internal
hernias. Ten-year retrospective review of patients at our institution yielded 49 cases of internal hernias. Majority of patients
presented with symptoms of acute (75%) or intermittent (22%) small bowel obstruction. While 16% of CT scans were suspicious
for internal hernia, in no cases the preoperative diagnosis of internal hernia was made. The most frequent internal hernias
were transmesenteric (57.0%) and 34 hernias (69%) were caused by previous surgery. All internal hernias were reduced and the
defects were repaired. Compromised bowel was present in 22 cases and 11 patients underwent small bowel resection. The mean
postoperative hospitalization was 10.9 days. The overall mortality rate from our series is 2%, and the morbidity rate is 12%.
Transmesenteric hernias, as complications of previous surgeries, are the most prevalent internal hernias. Preoperative diagnosis
of internal hernia is extremely difficult because of the nonspecific clinical presentation. However, if discovered promptly,
internal hernias can be repaired with acceptable morbidity and mortality.
Poster presentation at Digestive Disease Week, May 22, 2006, Los Angeles, California, USA. 相似文献