全文获取类型
收费全文 | 35426篇 |
免费 | 3390篇 |
国内免费 | 2446篇 |
专业分类
耳鼻咽喉 | 282篇 |
儿科学 | 500篇 |
妇产科学 | 392篇 |
基础医学 | 3780篇 |
口腔科学 | 726篇 |
临床医学 | 4603篇 |
内科学 | 5286篇 |
皮肤病学 | 328篇 |
神经病学 | 1381篇 |
特种医学 | 1196篇 |
外国民族医学 | 15篇 |
外科学 | 3733篇 |
综合类 | 6267篇 |
现状与发展 | 11篇 |
一般理论 | 2篇 |
预防医学 | 2555篇 |
眼科学 | 1012篇 |
药学 | 4070篇 |
25篇 | |
中国医学 | 2150篇 |
肿瘤学 | 2948篇 |
出版年
2024年 | 166篇 |
2023年 | 624篇 |
2022年 | 1545篇 |
2021年 | 1953篇 |
2020年 | 1539篇 |
2019年 | 1219篇 |
2018年 | 1276篇 |
2017年 | 1247篇 |
2016年 | 1127篇 |
2015年 | 1734篇 |
2014年 | 2159篇 |
2013年 | 2010篇 |
2012年 | 2819篇 |
2011年 | 2925篇 |
2010年 | 2032篇 |
2009年 | 1643篇 |
2008年 | 1997篇 |
2007年 | 1875篇 |
2006年 | 1797篇 |
2005年 | 1438篇 |
2004年 | 1131篇 |
2003年 | 965篇 |
2002年 | 853篇 |
2001年 | 685篇 |
2000年 | 675篇 |
1999年 | 665篇 |
1998年 | 434篇 |
1997年 | 415篇 |
1996年 | 360篇 |
1995年 | 349篇 |
1994年 | 304篇 |
1993年 | 177篇 |
1992年 | 215篇 |
1991年 | 163篇 |
1990年 | 126篇 |
1989年 | 111篇 |
1988年 | 118篇 |
1987年 | 116篇 |
1986年 | 95篇 |
1985年 | 70篇 |
1984年 | 28篇 |
1983年 | 25篇 |
1982年 | 12篇 |
1981年 | 16篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 2篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
To set up a method of amplification for the whole CagA gene of Helicobacter pylori and its fingerprinting by restriction fragment length polymorphism(RFLP),nested PCR was employed in combination with TD-PCR to amplify the gene and EcoRI and Hind Ⅲ were used to generate the RFLP fingerprinting.Target DNA fragments from 13 of 20 samples were successfully amplified and the relevant RFLP fingerprintings were obtained.It is concluded that the method can be used to amplify the whole CagA gene and CagA gene has apparent diversity of RFLP profile. 相似文献
42.
微创手术治疗高血压脑出血 总被引:10,自引:0,他引:10
目的 探讨微创手术治疗高血压脑出血的临床疗效。方法 132例高血压脑出血分成微创手术组(68例)和传统开颅手术组(64例),分析两组手术的特点和手术时机,比较两组手术治疗的疗效。结果 微创组术后GOS良好23例、中残24例、重残9例、植物生存3例、死亡9例;传统组术GOS良好16例、中残15例、重残12例、植物生存6例、死亡15例。两组超早期或早期手术均有良好的预后,而微创组效果更佳。结论 微创手术治疗高血压脑出血能明显提高临床疗效,降低病死率。 相似文献
43.
后腹腔镜手术在泌尿外科的应用 总被引:5,自引:2,他引:3
目的 探讨后腹腔镜手术治疗泌尿系疾病的方法及疗效。方法 采用后腹腔镜手术治疗泌尿系疾病3 5例 ,其中肾上腺肿瘤及肾上腺囊肿切除 13例 ,肾囊肿去顶术 15例 ,精索静脉曲张高位结扎术 4例 ,UPJ成形术 1例 ,乳糜尿行肾蒂淋巴管结扎术 1例 ,肾切除 1例。结果 3 5例手术全部成功。手术时间 3 0~ 13 0分钟 ,术中平均出血 2 0ml。术后住院时间 1.5~ 14天 ,平均 4.5天。结论 腹腔镜手术治疗泌尿系疾病 ,具有损伤小 ,住院时间短 ,恢复快 ,并发症少等优点 ,值得临床推广应用 相似文献
44.
BACKGROUND: At present, researches on differentiating from human adipose-derived adult stromal cells (hADASC) to neuron-like cells are focus on inducing by artificial-synthetic compound solution; however, hippocampal astrocyte conditioned medium (HCAM) can induce in vitro differentiation from hADASC to neuron-like cells is still unclear.
OBJECTIVE: To observe whether HCAM can induce in vitro differentiation from hADASC to neuron-like cells.
DESIGN: Randomized control study.
SETTING: Department of Neurology, Taixing People's Hospital; Central Laboratory, North China Coal Medical College.
MATERIALS: Donor of adipose tissue was donated by female volunteers suffering from caesarean section in the department of obstetrics & gynecology in our hospital and aged 20-35 years. Adipose tissue was collected from subcutaneous tissue of abdomen during the operation. In addition, 8 male newborn Wistar rats within 24 hours with average body mass of 20 g were provided by Animal Institute of Chinese Academy of Medical Sciences. Rabbit-anti-human Nestin polyclonal antibody, rabbit-anti-human glial fibriliary acidic protein (GFAP) polyclonal antibody, rabbit-anti-human neuro-specific enolase polyclonal antibody and mouse-anti-human microtubal associated protein 2 (MAP-2) polyclonal antibody were provided by Wuhan Boster Company.
METHODS: The experiment was carried out in the Central Laboratory of North China Coal Medical College from October 2004 to June 2005. hADASC was cultured with HCAM and its growth and morphological changes were observed under inverted phase contrast microscope. Immunocytochemistry, immunofluorescence and Western blotting were used to evaluate the expressions of Nestin, which was a specific sign of nerve precursor, neuro-specific enolase and MAP-2, which was a specific sign of nerve cell, and GFAP, which was a specific sign of neuroglial cells.
MAIN OUTCOME MEASURES: Nestin, which was a specific sign of nerve precursor, neuro-specific enolase and MAP-2, which was a specific sign of nerve cell, and GFAP, which was a specific sign of neuroglial cells.
RESULTS: On the 3rd day of culture, partial hADASC started deformation from slender shuttle-shape cells to neuron-like cells. It suggested that cells stretched out apophysis, which were mainly double-pole or multiple-pole cells. Five days later, immunohistochemical detection suggested that expression of Nestin (10.5±0.037) was found out in cells; meanwhile, expressions of GFAP (38.4±0.052) and neuro-specific enolase (NSE) (15.7±0.023) were also found out in cells; however, expression of MAP-2 was not observed. Western blot indicated that, 5 days after effect of HCAM, Nestin was found out in hADASC; meanwhile, expressions of GFAP and neuro-specific enolase were also found out; however, expression of MAP-2 was not observed.
CONCLUSION: HCAM can induce the differentiation from hADASC to neuron-like cells in vitro. 相似文献
45.
S Lalith Talagala Frank Q Ye Patrick J Ledden Scott Chesnick 《Magnetic resonance in medicine》2004,52(1):131-140
A variety of continuous and pulsed arterial spin labeling (ASL) perfusion MRI techniques have been demonstrated in recent years. One of the reasons these methods are still not routinely used is the limited extent of the imaging region. Of the ASL methods proposed to date, continuous ASL (CASL) with a separate labeling coil is particularly attractive for whole-brain studies at high fields. This approach can provide an increased signal-to-noise ratio (SNR) in perfusion images because there are no magnetization transfer (MT) effects, and lessen concerns regarding RF power deposition at high field because it uses a local labeling coil. In this work, we demonstrate CASL whole-brain quantitative perfusion imaging at 3.0 T using a combination of strategies: 3D volume acquisition, background tissue signal suppression, and a separate labeling coil. The results show that this approach can be used to acquire perfusion images in all brain regions with good sensitivity. Further, it is shown that the method can be performed safely on humans without exceeding the current RF power deposition limits. The current method can be extended to higher fields, and further improved by the use of multiple receiver coils and parallel imaging techniques to reduce scan time or provide increased resolution. 相似文献
46.
Effects of human amniotic fluid on cartilage regeneration from free perichondrial grafts in rabbits.
Güzin Ye?im Ozgenel Gülaydan Filiz Mesut Ozcan 《British journal of plastic surgery》2004,57(5):423-428
After the chondrogenic potential of free grafts of perichondrium was shown in several experimental studies, perichondrium has been used to reconstruct cartilage tissue in various clinical situations. This study investigates the effects of human amniotic fluid on neochondrogenesis from free perichondrial grafts in a rabbit model. Since this fluid contains high concentrations of hyaluronic acid, hyaluronic acid-stimulating activator, growth factors, and extracellular matrix precursors during the second trimester, it may have a stimulating effect on neochondrogenesis. Perichondrial grafts, measuring 20 x 20 mm2 were obtained from the ears of 144 New Zealand young rabbits and were sutured over the paravertebral muscles. The rabbits were randomly divided into three groups with 48 rabbits per group. In group 1, 0.3 ml human amniotic fluid, and in group 2, 0.3 ml saline were injected underneath the perichondrial grafts. Group 3 formed the control group in which no treatment was given. Histologically, neochondrogenesis was evaluated in terms of cellular form and graft thickness at 2, 4, 6, and 8 weeks after surgery. In group 1, the mature cartilage was generated quickly and the cartilage plate in this group was significantly thick and extensive when compared with groups 2 and 3 at 8 weeks ( p<0.05 ANOVA). In conclusion, our study shows that human amniotic fluid enhances neochondrogenesis from free perichondrial grafts. The rich content of hyaluronic acid and growth factors possibly participate in this result. 相似文献
47.
女性压力性尿失禁的微创治疗 总被引:1,自引:0,他引:1
目的探讨女性压力性尿失禁的发病机制和微创治疗方法。方法女性压力性尿失禁患者25例,经临床、尿动力学检查或膀胱尿道造影确诊,均为稳定性膀胱,无膀胱出口梗阻。采用无张力阴道吊带术(TVT),将吊带无张力置于尿道中段。结果手术时间平均(40±5)min;术中出血量平均(43±10)mL;术后平均留置导尿1.5 d;术后平均住院3 d。23例患者术后尿失禁症状均消失,其中2例患者术后出现尿潴留,留置导尿1周后好转,尿潴留症状消失,尿失禁未复发;2例尿失禁症状显著改善。结论TVT等微创术式因简单、微创、疗效好、并发症少等,目前是女性压力性尿失禁外科手术治疗的发展方向。 相似文献
48.
多巴酚丁胺负荷超声心动图及组织多普勒成像技术在诊断冠心病中的临床应用 总被引:1,自引:0,他引:1
目的探讨多巴酚丁胺负荷超声心动图(DSE)和组织多普勒成像技术(TDI)在冠心病(CHD)诊断中的应用价值,以寻求一种敏感的、无创的CHD诊断方法。方法选择胸闷或胸痛怀疑CHD患者40例,应用TDI测量静息状态(Rest)下前壁中段收缩峰值速度(Vs),以及多巴酚丁胺峰值负荷状态(Peak)下前壁中段Vs,同时测量静息心率和负荷心率;所有入选对象均进行冠脉造影,并根据左前降支狭窄程度是否大于等于50%分为左前降支狭窄组(LST组)与左前降支非狭窄组(non-LST组)。分别比较Rest和Peak前壁中段LST组与non-LST组平均Vs差别等。结果Rest前壁中段LST组与non-LST组Vs差别无显著性意义;但Peak前壁中段LST组与non-LST组差别有显著性意义。结论DSE结合TDI是诊断冠心病有价值的定量分析方法。DSE在诊断CHD时的敏感性、准确性明显优于静息状态超声心动图。 相似文献
49.
The articular cartilages from the left knee of 30 rabbits immobilized in casts in functional position were studied under transmission electron microscope. The pathological changes which begin at early stage of immobilization included both degeneration and repair of cartilage. The striking morphological features observed were: (1) most chondrocytes in various layers of cartilage underwent progresive degeneration; (2) the concomitant abnormal proliferation of some chondrocytes happened in a brief period. The changes in mechanical stress caused by immobilization affected the nutrition of cartilage and finally led to its reactive structural reformation. 相似文献
50.
大肠癌旁粘膜细胞的PCNA和AgNORs表达观察 总被引:2,自引:0,他引:2
用增殖细胞核抗原(PCNA)和核仁组成区嗜银蛋白(AgNORs)对35例大肠癌旁粘膜进行细胞增殖表达与观察。结果表明:癌旁粘膜的PCNA标记指数增多,标记增强,排列紊乱。AgNORs在癌旁粘膜中,颗粒增多、增大,形态多样,0 ̄1cm和2 ̄3cm组的标记指数与4 ̄5cm组的标记指数相比较,有显著或非常显著差异(P〈0.05或P〈0.01)。在DukeA、B期中,细胞标记指数增高增强,与癌的发生和患者 相似文献