全文获取类型
收费全文 | 2171篇 |
免费 | 123篇 |
国内免费 | 113篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 73篇 |
妇产科学 | 24篇 |
基础医学 | 184篇 |
口腔科学 | 51篇 |
临床医学 | 235篇 |
内科学 | 483篇 |
皮肤病学 | 50篇 |
神经病学 | 98篇 |
特种医学 | 552篇 |
外国民族医学 | 1篇 |
外科学 | 99篇 |
综合类 | 46篇 |
预防医学 | 165篇 |
眼科学 | 22篇 |
药学 | 154篇 |
中国医学 | 1篇 |
肿瘤学 | 163篇 |
出版年
2022年 | 8篇 |
2021年 | 12篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 22篇 |
2017年 | 8篇 |
2016年 | 24篇 |
2015年 | 25篇 |
2014年 | 23篇 |
2013年 | 52篇 |
2012年 | 32篇 |
2011年 | 86篇 |
2010年 | 74篇 |
2009年 | 61篇 |
2008年 | 45篇 |
2007年 | 100篇 |
2006年 | 65篇 |
2005年 | 80篇 |
2004年 | 47篇 |
2003年 | 29篇 |
2002年 | 44篇 |
2001年 | 42篇 |
2000年 | 50篇 |
1999年 | 45篇 |
1998年 | 92篇 |
1997年 | 102篇 |
1996年 | 113篇 |
1995年 | 74篇 |
1994年 | 68篇 |
1993年 | 78篇 |
1992年 | 38篇 |
1991年 | 50篇 |
1990年 | 39篇 |
1989年 | 68篇 |
1988年 | 63篇 |
1987年 | 88篇 |
1986年 | 63篇 |
1985年 | 93篇 |
1984年 | 56篇 |
1983年 | 52篇 |
1982年 | 35篇 |
1981年 | 34篇 |
1980年 | 45篇 |
1979年 | 21篇 |
1978年 | 19篇 |
1977年 | 19篇 |
1976年 | 30篇 |
1975年 | 20篇 |
1971年 | 8篇 |
1970年 | 7篇 |
排序方式: 共有2407条查询结果,搜索用时 15 毫秒
31.
0 引言 胰腺多房性潴留性囊肿极为罕见,我科收治1例,报道如下.1 病例报告 患者,男,29岁,因发现右上腹包块11d入院,缘于11d前无明显诱因感右上腹痛,仅局限于右上腹部,无肩背部放散痛,伴间歇性发热,体温最高达38.3℃,经抗炎,对症治疗无效.并逐渐可触及右上腹有一肿块,在当地医院行穿刺检查为脓血性液体.镜检发现炎性细胞,B超示:胆囊窝下方及右肾内侧及腹腔动脉,下腔静脉外前方可见异常区,大小约9.1cm×6.6cm×7.6cm,边界清楚,形态不规则,内呈蜂窝状,可见多个大小不等的液性暗区,CT示:右上腹部上腔静脉前方6.0cm×9.0cm肿块和周围组织粘… 相似文献
32.
A young boy presented with an uncommon finding of impaction of upper right central incisor and transposition of canine and lateral incisor on the same side. Esthetic management of his cosmetic problem which included fixed appliance therapy followed by light cure restorations is discussed.KEY WORDS: Impaction, Transposition 相似文献
33.
34.
BACKGROUND AND OBJECTIVE: This study was conducted to determine preoperative predictors of postoperative visual acuity in patients with acquired immunodeficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis and retinal detachment. PATIENTS AND METHODS: The study design was a retrospective chart review of 38 eyes in 33 patients with AIDS and CMV retinitis who had retinal reattachment surgery by pars plana vitrectomy with the use of silicone oil tamponade. Factors considered included: preoperative visual acuity, macular attachment status and CMV activity at the time of surgery, and length of time from diagnosis of retinal detachment to surgical repair. RESULTS: Retinal reattachment was achieved in 37 of 38 eyes. Mean interval from surgery to best corrected visual acuity (VA) was 9 weeks. The mean best corrected post-op VA was 20/70. Approximately half of the patients died within 7 months of the surgery. There was good correlation between preoperative VA and best attained postoperative VA (Spearman's: r = 0.5139, P = 0.001). The interval from retinal detachment to surgery, and best attained postoperative VA did not correlate (Spearman's: r = 0.2339, P=0.158). The lack of macular CMV retinitis correlated well with postoperative VA (P = 0.0066, Wilcoxon rank-sum test). CONCLUSIONS: Preoperative visual acuity and macular attachment status correlates with better postoperative visual acuity results, whereas early surgical repair of retinal detachment does not. 相似文献
35.
Glazer Samuel S. Galanter Marc Megwinoff Olga Dermatis Helen Keller Daniel S. 《Substance Abuse》2003,24(2):93-100
The therapeutic alliance is a well-studied construct factor that is important to outcome in many forms of individual therapy. Therapeutic alliance has been rarely studied in group therapy and results in addiction treatment have been mixed. In this paper, we studied the presence of a therapeutic alliance in Network Therapy: an approach that uses peer and family support in addiction treatment. Twenty-one participants undergoing Network Therapy for cocaine addiction were observed on videotape, and were rated on therapeutic alliance using the Working Alliance Inventory and the Penn Helping Alliance Rating Scale. Results showed a significant positive correlation between therapeutic alliance and outcome as measured by the percentage of cocaine-free urine toxicology screens and by eight consecutive cocaine-free urines. 相似文献
36.
37.
38.
Isolation and characterization of propagable cell lines (HUNC) from the androgen-sensitive Dunning R3327H rat prostatic adenocarcinoma 总被引:1,自引:0,他引:1
Presnell SC; Borchert KM; Glover WJ; Gregory CW; Mohler JL; Smith GJ 《Carcinogenesis》1998,19(4):585-590
The Dunning H rat prostate tumor (R3327H) is a widely used experimental
model of human prostatic adenocarcinoma (CaP). The Dunning H tumor has been
characterized as androgen-sensitive, androgen-receptor (AR) positive,
prostate-specific antigen and prostatic acid phosphatase (PAP) positive. To
date, the tumor has been maintained by serial passage in vivo because of
the lack of an in vitro cell line that retains the characteristics of the
in vivo tumor. The objective of the present study was to establish a
propagable cell line from R3327H adenocarcinoma that maintained androgen
sensitivity and expression of AR, PSA and PAP. Tissue harvested from an in
vivo R3327H tumor was dissociated with collagenase and placed into
Richter's improved media (with supplements). A cytokeratin-positive
epithelial cell line (HUNC- E) and a vimentin-positive stromal cell line
(HUNC-S) were generated from the primary culture, subcultured continuously
for >300 days, and passaged >50 times. Survival of the HUNC-E cell
line in vitro depended on several media supplements, including
nicotinamide, insulin, transferrin, selenium and epidermal growth factor
(EGF). HUNC-E cells expressed AR and produced PSA and PAP throughout the
culture period, as confirmed by immunocytochemistry and Western blot
analyses. Addition of 14 nM testosterone (T) or dihydrotestosterone (DHT)
to HUNC-E cells, stimulated DNA synthesis as well as anchorage-independent
growth and PSA production, which demonstrated the androgen-sensitive nature
of the cells in vitro. When HUNC-E and HUNC-S cells were combined in a 3:1
ratio and introduced subcutaneously into syngeneic male hosts, tumors
formed in 2/3 animals with an average latency of 7 months. RT-PCR and
immunocytochemical characterization of the HUNC cell lines revealed that
the cells expressed several growth factors and their cognate receptors,
including HGF, TGF-alpha and the TGF-betas, indicating the establishment of
potential autocrine loops in the neoplastic cells. The HUNC-E and HUNC-S
CaP cell lines, which retain the characteristics of the epithelial and
stromal components of the in vivo R3327H tumor, will allow a more thorough
and informative molecular and biological analysis of prostatic
adenocarcinoma.
相似文献
39.
Previous work has shown that sustained increased and decreased cell
proliferation, induced by dietary zinc deficiency and caloric restriction
respectively, influence the course of N- nitrosomethylbenzylamine
(NMBA)-induced esophageal carcinogenesis in rats. The present study
considered whether the increased cell proliferation and esophageal tumor
incidence induced by zinc deficiency are reversed upon zinc replenishment.
Weanling rats were maintained initially on a deficient diet containing 4
p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six
intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated.
After the second NMBA dose, the rats were divided into three dietary
groups. One group was continued on the deficient diet, while the other two
groups were switched to diets containing either 75 or 200 p.p.m. zinc, with
half of the members in each group fed ad libitum and half pair-fed with
deficient rats. NMBA-untreated controls were similarly replenished. At
various time points, esophageal cell proliferation was assessed in five
animals from each group by immunohistochemical detection of cells in S
phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the
first dose, esophageal tumor incidence was greatly reduced, from 100% in
the deficient group to 26 and 14% respectively in the replenished groups
fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the
replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number
of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats,
to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following
zinc replenishment, esophageal cell proliferation, as measured by labeling
index (LI), the number of labeled cells and the total number of cells, was
markedly decreased in NMBA-untreated and -treated esophagi as compared with
those in corresponding deficient esophagi. Thus, the esophageal cell
proliferation induced by zinc deficiency is reversed by zinc replenishment
and replenished animals have a markedly lower incidence of esophageal
tumors.
相似文献
40.
Illes J Glover GH Wexler L Leung AN Glazer GM 《Academic radiology》2000,7(9):717-24; discussion 725-6
RATIONALE AND OBJECTIVES: The purpose of this report is to describe the development and implementation of a faculty mentoring program in radiology designed to promote the career development of junior faculty and enhance communication in the department. MATERIALS AND METHODS: The mentoring program was implemented in five stages: organizational readiness, participant recruitment, mentor matching and orientation, implementation, and evaluation. Evaluations were based on Likert scale ratings and qualitative feedback. A retrospective analysis was also conducted of the annual performance reviews of junior faculty in the areas of research, teaching, patient care, and overall performance. RESULTS: An average of 83% (19 of 23) of the junior faculty participated in the pilot phase of the mentoring program. During five rounds of testing, the median rating (1 indicates not important; 10, extremely important) from responding junior faculty was 10 for overall value of individual mentoring meetings; the median rating for the mentors responding was 8.75. Research and academic development were identified as the areas of greatest importance to the faculty. Research and patient care were most improved as assessed by faculty peers during performance reviews. The schedule of semiannual formal mentoring meetings was reported to be optimal. CONCLUSION: The program was implemented to the satisfaction of junior faculty and mentors, and longitudinal performance suggests positive effects. Issues to be contended with include confidentiality and the time needed for mentoring beyond already saturated schedules. Overall, the authors propose that mentoring programs can be an asset to academic radiology departments and a key factor in maintaining their vitality. 相似文献