全文获取类型
收费全文 | 15300篇 |
免费 | 845篇 |
国内免费 | 214篇 |
专业分类
耳鼻咽喉 | 129篇 |
儿科学 | 254篇 |
妇产科学 | 212篇 |
基础医学 | 1360篇 |
口腔科学 | 231篇 |
临床医学 | 2185篇 |
内科学 | 1346篇 |
皮肤病学 | 107篇 |
神经病学 | 2825篇 |
特种医学 | 750篇 |
外科学 | 1628篇 |
综合类 | 1830篇 |
一般理论 | 2篇 |
预防医学 | 976篇 |
眼科学 | 116篇 |
药学 | 1067篇 |
8篇 | |
中国医学 | 168篇 |
肿瘤学 | 1165篇 |
出版年
2024年 | 17篇 |
2023年 | 221篇 |
2022年 | 448篇 |
2021年 | 638篇 |
2020年 | 565篇 |
2019年 | 475篇 |
2018年 | 548篇 |
2017年 | 489篇 |
2016年 | 469篇 |
2015年 | 402篇 |
2014年 | 1014篇 |
2013年 | 1110篇 |
2012年 | 724篇 |
2011年 | 913篇 |
2010年 | 695篇 |
2009年 | 786篇 |
2008年 | 784篇 |
2007年 | 704篇 |
2006年 | 701篇 |
2005年 | 507篇 |
2004年 | 461篇 |
2003年 | 405篇 |
2002年 | 286篇 |
2001年 | 311篇 |
2000年 | 245篇 |
1999年 | 246篇 |
1998年 | 197篇 |
1997年 | 214篇 |
1996年 | 202篇 |
1995年 | 165篇 |
1994年 | 145篇 |
1993年 | 105篇 |
1992年 | 117篇 |
1991年 | 104篇 |
1990年 | 103篇 |
1989年 | 71篇 |
1988年 | 89篇 |
1987年 | 70篇 |
1986年 | 53篇 |
1985年 | 87篇 |
1984年 | 77篇 |
1983年 | 56篇 |
1982年 | 70篇 |
1981年 | 41篇 |
1980年 | 43篇 |
1979年 | 39篇 |
1978年 | 24篇 |
1977年 | 34篇 |
1976年 | 26篇 |
1973年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Jan Lycke Bo Svennerholm Anders Svenningsson Walter Muranyi Rolf M. Flügel Oluf Andersen 《Journal of neurology》1994,241(4):204-209
The role of human spumaretrovirus (HSRV) infections in the pathogenesis of multiple sclerosis (MS) was investigated with recombinant HSRV env-specific enzyme-linked immunosorbent assay. The presence of HSRV antibodies was determined in pairs of serum and cerebrospinal fluid (CSF) samples from 60 MS patients. In 7 of these patients serial serum and CSF samples were obtained in relation to the clinical activity of the disease during a period of 2 years. No increased antibody reactivity was demonstrable in the MS population compared with 14 aseptic meningitis patients, 50 blood donors and 16 healthy controls. Slightly elevated levels of antibodies were demonstrable in serum and/or CSF in 4 MS patients but also in 1 patient with aseptic meningitis, 1 blood donor and 1 child. No marked serum or CSF HSRV antibody fluctuation was observed in the MS patients followed longitudinally. Thus, this study does not support the involvement of HSRV in the pathogenesis of MS. 相似文献
42.
目的探讨结节性硬化症多器官损害的临床特点以提高诊断治疗水平。方法回顾性分析7例结节性硬化症伴皮肤、大脑、肾脏、肝脏等多器官损害患者的临床资料,探讨其特征性临床表现及影像学改变。结果7例患者均有多器官损害,累及两个器官3例,3个及以上器官损害4例;皮肤损害主要为面部血管纤维瘤6例,皮肤色素脱失斑7例,鲨鱼皮斑3例,趾甲下纤维瘤1例;癫痫发作6例,智力低下4例,颅脑CT或MRI检查提示室管膜下结节4例,皮质结节2例;4例合并双侧肾脏多发错构瘤,1例合并肝脏错构瘤。结论特殊的皮肤损害、癫痫发作、智力低下,脑CT或MRI检查提示室管膜下结节或皮质结节或内脏多发性错构瘤为本病的主要临床特征,提高本病的认识有助于早期诊断和治疗。 相似文献
43.
Esther Kahana Nelly Zilber Joseph H. Abramson Victor Biton Yaffa Leibowitz Oded Abramsky 《Journal of neurology》1994,241(5):341-346
The incidence and prevalence of multiple sclerosis (MS) were compared, controlling for age, in native-born Israelis of different origins and in immigrants to Israel. This comparison was carried out in two populations, countrywide and in Jerusalem. In the countrywide population, ascertainment was based mainly on hospitalizations; it included 252 patients who were native-born and 150 who had immigrated from Africa-Asia (AA immigrants). The 89 MS patients of Jerusalem also included patients diagnosed in outpatient clinics. In native-born Israelis whose father was born in Europe-America (I-EA), the incidence and prevalence of MS were found to be as high as or even higher than that found previously in immigrants from Europe-America. Among native-born Israelis whose father was born in Africa or Asia (I-AA), the yearly age-adjusted incidence and prevalence rates were found to be 1.4- to 1.8-fold higher than among AA immigrants, pointing to environmental factors. The incidence and prevalence rates in the I-EA were 1.2- to 1.6-fold higher than in the I-AA, pointing to genetic factors. These results seem to point to both environmental and genetic factors in the aetiology of MS. Further research is needed, however, to disentangle the genetic factors from possible environmental differences in the two ethnic groups. 相似文献
44.
胫骨平台骨折合并软组织损伤的临床分析与治疗 总被引:1,自引:0,他引:1
目的:总结分析各种胫骨平台骨折合并不同类型软组织损伤中的相互关系,探索其诊断与治疗策略。方法:自1995年10月至2004年1月共治疗胫骨平台骨折合并软组织损伤143例。所有病例均行开放复位内固定,对不同类型软组织损伤同时采取相应的处理方法。结果:术后随访129例,随访时间6到27个月,平均16个月;骨折均于12周内愈合,所有患者均恢复了患肢的正常力线,患肢稳定。结论:胫骨平台骨折合并软组织损伤的诊断必须早期、全面、详细、明确,坚强的内固定基础上,对不同类型的软组织损伤必须正确处理,术后应注意被动伸膝及CPM功能锻炼,这样才能最大程度挽救膝关节功能,减少晚期并发症。 相似文献
45.
目的:观察卡巴胆碱(carbachol,Car)对酵母多糖致多器官功能障碍综合征(MODS)小鼠多脏器功能和结构损伤的防护作用。方法:采用腹腔注射酵母多糖的方法复制小鼠MODS模型。雄性C57BL/6小鼠随机分为正常对照组(n=10),MODS 6、24、48 h组(n=30)和MODS Car 6、24、48 h防治组(n=30)。MODS组在致伤后腹腔注入生理盐水;MODS Car防治组在致伤前24 h内分3次灌胃注入卡巴胆碱。观察酵母多糖致伤后早期(48h内)动物死亡率,检测各组血丙氨酸转氨酶活性、尿素氮和肌酐水平,镜下观察致伤后48 h动物肝、肺、肾、心等脏器的组织病理学改变。结果:在酵母多糖致伤后48h内,MODS组小鼠死亡率达26.6%,MODS Car防治组的小鼠死亡率为10.0%。MODS组小鼠血浆ALT、BUN和Cr在伤后6h升高,而同时间点经卡巴胆碱预处理的小鼠血浆ALT、BUN和Cr仅略有升高,明显低于MODS组。光镜下观察发现,MODS组小鼠肝脏、肺脏、肾脏和心脏发生明显的病理改变,主要表现为脏器实质细胞浊肿、变性,间质充血、水肿和炎性细胞浸润,而卡巴胆碱防治组小鼠上述病变明显减轻。结论:预防性给予卡巴胆碱可以降低MODS急性期动物的死亡率,减轻脏器功能和结构的损伤,对急性炎症期的脏器损伤具有保护作用。 相似文献
46.
Lambros Lazuras Angelos Rodafinos Georgios Matsiggos Alexander Stamatoulakis 《Social science & medicine (1982)》2009
The present study examined four potential roles of work-related negative affectivity on the associations between self-reported occupational stress and physical well-being among telecommunication employees in Greece. Participants (764, predominantly male) completed a battery of self-report measures on perceived occupational stress, negative affectivity, and illness symptoms. In line with previous research, negative affectivity exerted a nuisance effect, by inflating the association between reported stressors and illness symptoms, and significantly predicted illness symptoms, over and above the effects of stressors. In addition, negative affectivity influenced reported illness symptom indirectly, through the effects of stressors, and moderated the relationship between interpersonal conflict at work and illness symptoms. The findings suggest that negative affectivity can largely explain and influence in different ways the associations between self-reported stress and physical strain. It is recommended that future studies of occupational stress should control for the effects of negative affectivity, and that health professionals should be cautious of its effects when interpreting relationships between self-reported occupational stress and physical well-being. 相似文献
47.
扩散张量成像和三维脑白质束示踪在多发性硬化中的临床应用 总被引:4,自引:0,他引:4
目的 探讨多发性硬化(MS)患者的MS斑块、斑块旁脑白质和T2WI上表现为正常的脑白质区(NAWM)的扩散张量成像(DTI)特点,并探讨DTI和三维脑白质束示踪技术对MS的应用价值。方法 对32例MS患者和32名与MS患者年龄性别配对的正常人进行头部DTI检查,生成表观扩散系数图(ADC)和部分各向异性图(FA),分别选取MS斑块、斑块旁脑白质区、NAWM区和对照组正常人相应脑白质区测量ADC值和FA值,并使用示踪技术做出三维脑白质束图像。结果 MS斑块、斑块旁脑白质区、NAWM区和对照组的ADC平均值分别为(1.233±0.119)、(0.973±0.098)、(0.748±0.089)×10^-3mm^2/s和(0.620±0.094)×10^-3mm^2/s,FA平均值分别为0.225±0.052、0.311±0.050、0.421±0.070和0.476±0.069。对MS斑块、斑块旁脑白质、NAWM数据进行随机区组方差分析最小显著差法检验,差异有统计学意义(P〈0.01)。MS斑块、斑块旁脑白质、NAWM分别和对照组配对t检验,差异有统计学意义(P〈0.01)。用三维脑白质束图像可以观察到MS斑块。结论 使用DTI检查生成的ADC图和FA图可以有助于评价MS中各部位脑白质的改变。通过三维脑白质束示踪图像可以立体直观地显示MS斑块区白质束的异常。 相似文献
48.
Khaled Z Abd-Elmoniem Nael F Osman Jerry L Prince Matthias Stuber 《Magnetic resonance in medicine》2007,58(1):92-102
Three-dimensional imaging for the quantification of myocardial motion is a key step in the evaluation of cardiac disease. A tagged magnetic resonance imaging method that automatically tracks myocardial displacement in three dimensions is presented. Unlike other techniques, this method tracks both in-plane and through-plane motion from a single image plane without affecting the duration of image acquisition. A small z-encoding gradient is subsequently added to the refocusing lobe of the slice-selection gradient pulse in a slice following CSPAMM acquisition. An opposite polarity z-encoding gradient is added to the orthogonal tag direction. The additional z-gradients encode the instantaneous through plane position of the slice. The vertical and horizontal tags are used to resolve in-plane motion, while the added z-gradients is used to resolve through-plane motion. Postprocessing automatically decodes the acquired data and tracks the three-dimensional displacement of every material point within the image plane for each cine frame. Experiments include both a phantom and in vivo human validation. These studies demonstrate that the simultaneous extraction of both in-plane and through-plane displacements and pathlines from tagged images is achievable. This capability should open up new avenues for the automatic quantification of cardiac motion and strain for scientific and clinical purposes. 相似文献
49.
Despite the fact that both H-2K and D molecules are up-regulated in the central nervous system (CNS) following Theiler's murine encephalomyelitis virus (TMEV) infection, resistance in this virus model of multiple sclerosis maps exclusively to D. To address this paradox, we examined the ability of the K and D molecules to present viral antigens to cytotoxic T lymphocytes (CTL). Whereas no virus-specific CTL were detected in the CNS of susceptible B10.Q and B10.S mice 7 days post-infection, D-restricted CTL were identified readily in the CNS of resistant B10 animals. There was no evidence of K-restricted CTL in the CNS of B10 mice at day 7 post-infection. The presence of both K- and D-restricted virus-specific CTL in the spleen of immunized B10 mice demonstrates that the exclusive use of D molecules by CTL in the CNS of mice 7 days post-infection is not due to the inability of the K molecules to present viral peptides to lymphocytes. We conclude that the prominent role of the D locus in determining resistance or susceptibility to TMEV-induced demyelination is determined by factors governing the regulation of the immune response, and not by the presence or absence of CTL precursors capable of recognizing viral peptides presented by the K and D antigen-presenting molecules, or by differences in the ability of the K and D molecules to present viral peptides. 相似文献
50.
Summary Human fibrin glue (Tissucol) is a plasma-derived compound endowed with adhesive and hemostatic properties and possessing a specific local anti-infection function mediated through activation of nonspecific immunity elements. The aim of this study is to show that in patients who have undergone prolonged reconstructive plastic surgery following cancer resection, Tissucol decreases infectious complications as compared to a control group. Between June 1985 and February 1988, 51 subjects were treated with fibrin glue during reconstruction operations. Analysis of the results showed that Tissucol produced a statistically significant reduction both of immediate complications, such as inflammation and partial separation of the surgical wound, and of delayed complications, such as scar hypertrophy and cutaneous fistulae. In conclusion, patients treated with Tissucol showed a better quality of surgical wound, a more rapid postoperative functional recovery and consequently a decrease in the duration of hospitalization. 相似文献