全文获取类型
收费全文 | 3319篇 |
免费 | 301篇 |
国内免费 | 103篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 39篇 |
妇产科学 | 54篇 |
基础医学 | 535篇 |
口腔科学 | 47篇 |
临床医学 | 303篇 |
内科学 | 392篇 |
皮肤病学 | 47篇 |
神经病学 | 210篇 |
特种医学 | 246篇 |
外科学 | 194篇 |
综合类 | 567篇 |
现状与发展 | 1篇 |
预防医学 | 323篇 |
眼科学 | 46篇 |
药学 | 293篇 |
10篇 | |
中国医学 | 189篇 |
肿瘤学 | 212篇 |
出版年
2024年 | 7篇 |
2023年 | 48篇 |
2022年 | 67篇 |
2021年 | 88篇 |
2020年 | 82篇 |
2019年 | 102篇 |
2018年 | 92篇 |
2017年 | 91篇 |
2016年 | 106篇 |
2015年 | 121篇 |
2014年 | 228篇 |
2013年 | 223篇 |
2012年 | 177篇 |
2011年 | 191篇 |
2010年 | 161篇 |
2009年 | 166篇 |
2008年 | 136篇 |
2007年 | 164篇 |
2006年 | 165篇 |
2005年 | 128篇 |
2004年 | 130篇 |
2003年 | 120篇 |
2002年 | 97篇 |
2001年 | 102篇 |
2000年 | 94篇 |
1999年 | 78篇 |
1998年 | 69篇 |
1997年 | 63篇 |
1996年 | 44篇 |
1995年 | 35篇 |
1994年 | 42篇 |
1993年 | 28篇 |
1992年 | 44篇 |
1991年 | 47篇 |
1990年 | 29篇 |
1989年 | 22篇 |
1988年 | 25篇 |
1987年 | 26篇 |
1986年 | 20篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有3723条查询结果,搜索用时 31 毫秒
1.
2.
3.
目的比较2%强化戊二醛(下称戊二醛)气雾熏蒸法与浸泡消毒法消毒吸痰管的效果.方法消毒按5周期(1个周期12 d)进行,每周期将200根使用过的吸痰管经初步处理,即5% 84消毒液浸泡30 min后清水冲洗干净晾干.将每周期200根吸氮管随机均分为实验组和对照组,实验组采用戊二醛原液气雾熏蒸法消毒4 h,对照组采用戊二醛原液浸泡消毒30 min,12 d为1个周期.两组分别于第1、6、12天对消毒后的吸痰管及消毒过程中的戊二醛采样行细菌菌落数计数,并观察有无细菌生长.结果两组每周期第1、6天吸痰管和消毒液标本均未检测出细菌,且无致病微生物生长;每周期第12天对照组吸痰管和消毒液标本均检测出细菌,实验组未检测出细菌.结论气雾熏蒸法消毒灭菌效果可靠,具有节约开支、使用方便、有利于吸痰管的保存与放置等优点. 相似文献
4.
目的 探讨Ⅴ型斜视伴原发性下斜肌功能过强的治疗效果。方法根据手术方式将49例Ⅴ型斜视伴下斜肌功能过强惠者分为四组,分别采用水平肌加强减弱术不联合下斜肌切断减弱术(Ⅰ组)、联合单侧下斜肌切断减弱术(Ⅱ组)、联合双侧下斜肌对等切断减弱术(Ⅲ组)及联合双侧下斜肌不对等切断并部分切除减弱术(Ⅳ组)治疗Ⅴ型斜视。结果Ⅴ型斜视伴原发性下斜肌功能过强采用四种方式治疗后,眼位正位,下斜肌功能亢进改善+~++,双侧下斜肌功能对等,术前术后原在位度数和上下注视25。斜视角之差的差异有非常显著性(P〈0.001)。结论根据单侧或双侧下斜肌功能过强的具体情况来选择不同的手术方式治疗Ⅴ型斜视伴原发性下斜肌功能过强,眼位矫正满意,同时手术方式简单、安全有效。 相似文献
5.
Timson C Appanna Shareen H Doak Spencer A Jenkins Howard G Kynaston Timothy P Stephenson James M Parry 《International journal of urology》2007,14(6):539-544
OBJECTIVE: Tumors arising within augmentation cystoplasties are aggressive, have poor prognosis and the majority are not detected at follow-up cystoscopy. Genetic changes in tumors precede morphological abnormalities. Therefore, the aim of this study was to investigate whether genetic abnormalities detected by comparative genomic hybridization (CGH) could be used to identify those patients with augmentation cystoplasties at increased risk of tumorigenesis. METHODS: Bladder biopsy samples were obtained from 16 augmentation cystoplasty patients both distant from and near to the enterovesical anastomosis. CGH was used to detect genetic abnormalities in DNA extracted from the biopsies, archival specimens of two augmentation cystoplasties and two de novo bladder adenocarcinomas. RESULTS: A greater number of amplifications on 2p, 3q, 8q, 9p, 17p, 18pq and 20pq, were observed in bladder biopsies obtained near to the enterovesical anastomosis compared to those taken distant to the suture line. CGH of archival augmentation cystoplasty tumor DNA indicated abnormalities at several loci with amplifications at 2q, 5q, 10p and 21pq, while deletions occurred at 5p and 16p. CONCLUSIONS: The results of this study suggest that the urothelium adjacent to the bladder and/or bowel anastomosis in augmentation cystoplasties is genetically unstable. Furthermore, longitudinal studies are required to establish whether or not patients exhibiting genetic instability following augmentation cystoplasty are at greater risk of developing tumors than those with genetically stable epithelia. 相似文献
6.
HA Carpay P Matthijsse M Steinbuch PGH Mulde 《Cephalalgia : an international journal of headache》1997,17(5):591-595
In an open, randomized cross-over study in 124 patients, we compared the efficacy, safety and patient preference of oral and subcutaneous sum triptan in the acute treatment of migraine. Patients were treated for 3 attacks or 3 months and then crossed over. Primary clinical efficacy was defined as a reduction in headache severity on a four-point self-rating scale from severe (3) or moderate (2) to mild (1) or none (0), or mild (1) to none (0). Efficacy was evaluated 2 h after the administration of subcutaneous and 4h after the administration of oral sumatriptan. Subcutaneous sumatriptan was significantly more effective than oral sumatriptan in relieving headache (over all three attacks 78% vs 61% improvement), improving clinical disability (55% vs 41 % improvement) and relieving nausea (69% vs 53%), vomiting (72% vs 32%) and phono- or photophobia (67% vs 49%). Median time to recurrence was shorter after subcutaneous (12.5 h) than after oral sumatriptan (18 h); the number of patients experiencing a recurrence was similar Patients reported more adverse events after subcutaneous sumatriptan (1.32 per attack) than after the oral form (0.85 per attack), but all adverse events were mild to moderate in intensity and of short duration. Patient opinion was more often positive after subcutaneous sumatriptan. These results may be useful in counselling patients to choose between the available marketed formulations of sumatriptan. 相似文献
7.
目的 : 海岛学生饮食结构中含有碘丰富的海产品。本研究旨在了解海岛学生的碘营养状况 ,评价食盐补碘的利弊。方法 : 对定海农村 (食用碘盐 )和岱山农村 (不食用碘盐 )的学校中随机抽取的 1 2个班级 ,对碘盐组和非碘盐组的饮食碘摄入和尿碘水平等变量进行描述 ,并分别以尿碘和甲状腺肿率为应变量进行单因素和多因素回归分析。结果 : 碘盐组除碘盐外每日碘摄入量中位数为 1 84μg,而不食用加碘盐的组为 1 0 5 μg,两组饮食碘摄入有显著性差异 (u=4.71 0 ,P=0 .0 0 0 ) ,而尿碘水平在食用碘盐组和不食用碘盐组分别为 1 6 9μg/L和 1 2 9μg/L,两组间有显著性差异 (u=6 .3 0 2 ,P=0 .0 0 0 )。多因素分析中性别和是否食用碘盐对尿碘水平有显著性意义 (P<0 .0 5 ,OR值分别为 0 .76 5 ,1 .93 3 )。甲状腺肿学生和正常学生的饮食碘和尿碘无统计学差异 (P>0 .0 5 )。Poisson回归分析中性别和是否食用碘盐对甲状腺肿率有影响 (P<0 .0 5 ,OR值分别为2 .2 5 ,3 .5 2 )。结论 : 舟山海岛学生要注意补碘过程中可能出现的碘过量问题。 相似文献
8.
测定72例健康老年人(60-84岁)和65例健康青中年人(20-50岁)血清和尿β2微球蛋白(β2m),发现前血清β2m浓度比后明显增高(p<0.001);老年组≥70岁尿液β2m浓度也明显增高(p<0.05)。结果表明肾小球滤过率下降随年龄增长而降低,以后再出现肾小管功能减退。本试验较血清尿素氮、肌酐和内生肌酐清除率测定更为敏感。 相似文献
9.
V W Ansanelli 《Lasers in surgery and medicine》1986,6(5):470-472
Review of the literature reveals little to no data regarding the use of the CO2 laser as a surgical modality in the local treatment of breast cancer. This study was undertaken to determine if the CO2 laser is a surgical improvement over the scalpel, influencing patient care during the surgical and postsurgical period. In the author's series, a total of 209 procedures were performed. Within this group, 105 cases were performed with CO2 laser and 104 cases performed with the scalpel. Biopsies were always performed as a separate procedure prior to definitive surgery. This study was not designed to compare cure rates, the medical follow-up period being 1 year. The results of this study demonstrate a significant improvement in patients' postoperative care, surgical technique, and hospital cost-effectiveness. 相似文献
10.
Z. Świderski 《Helminthologia》2007,44(3):130-136
Summary Ultrastructural features of juvenile cestodes (metacestodes) can provide useful characters for phylogenetic and evolutionary
analyses. Until now, however, they have been relatively little utilised (Beveridge 2001, Chervy 2002). The postembryonic development
and structure of fully formed metacestodes were examined in two cyclophyllideans: Taenia parva Baer, 1926 (Taeniidae); and Sobolevitaenia verulamii (Mettrick, 1958) Korniushin, 1972 (Dilepididae). In T. parva, three developmental stages were recognized: (1) an early stage of exogenous budding at the surface of the central vesicle;
(2) a stage of polycephalic cyst development accompanied by segmentation of the growing metacestode strobila and an obvious
decrease in the size of the central vesicle; (3) a fully formed metacestode of the strobilocercus type with 14–24 invaginated
scoleces. The tegument, scolex, subtegumental musculature of the strobilar segments, protonephridial system, calcareous corpuscles
and medullary parenchyma of larvae exhibit general similarity to the same structures in adults at both LM and TEM levels.
The morphogenesis of the metacestode of T. parva is compared with that of polycephalic metacestodes of other Taenia spp. (T. krepkogorski, T. twitchelli and T. endothoracica) and with other asexually multiplying metacestodes (Mesocestoides vogae, hymenolepidids and dilepidids). In S. verulamii, the body of the cysticercoid with invaginated scolex armed with a double crown of rostellar hooks was completely surrounded
by the cercomer, which appears to be separated from the cyst and scolex. The surface of the suckers is covered with a thick
layer of glycocalyx. Five cell types were distinguished in the sections: (1) perikarya of metacestode tegument; (2) glycolgen-storing
parenchymal cells; (3) glandular-type cells with large, electron-dense secretory-like granules; (4) flame cells; and (5) calcareous
corpuscle-forming cells. The surface of the cercomer is covered by elongated microvilli, which evidently differ from characteristic
microtriches covering all other parts of the metacestode surface. The ultrastructure of S. verulamii evidently differs from that of the other dilepidid cestode examined to date, Lateriporus geographicus, the cyst wall of which more resembles cysticercoids of Hymenolepididae than those of Dilepididae. Concluding remarks: Ultrastructural
studies on metacestodes have considerable promise for providing important new characters for phylogenetic analysis. New TEM
data on a great variety of cestode species are urgently needed. Until now, this field has not been exploited in a systematic
fashion. Until more comprehensive studies become available, the current data are not yet amenable to analysis. 相似文献