全文获取类型
收费全文 | 12684篇 |
免费 | 736篇 |
国内免费 | 476篇 |
专业分类
耳鼻咽喉 | 102篇 |
儿科学 | 321篇 |
妇产科学 | 206篇 |
基础医学 | 805篇 |
口腔科学 | 164篇 |
临床医学 | 1131篇 |
内科学 | 1392篇 |
皮肤病学 | 49篇 |
神经病学 | 304篇 |
特种医学 | 564篇 |
外国民族医学 | 1篇 |
外科学 | 2419篇 |
综合类 | 2129篇 |
预防医学 | 716篇 |
眼科学 | 1016篇 |
药学 | 1232篇 |
22篇 | |
中国医学 | 309篇 |
肿瘤学 | 1014篇 |
出版年
2024年 | 39篇 |
2023年 | 189篇 |
2022年 | 388篇 |
2021年 | 503篇 |
2020年 | 389篇 |
2019年 | 341篇 |
2018年 | 354篇 |
2017年 | 416篇 |
2016年 | 481篇 |
2015年 | 520篇 |
2014年 | 1155篇 |
2013年 | 1002篇 |
2012年 | 1011篇 |
2011年 | 940篇 |
2010年 | 803篇 |
2009年 | 749篇 |
2008年 | 644篇 |
2007年 | 656篇 |
2006年 | 515篇 |
2005年 | 440篇 |
2004年 | 360篇 |
2003年 | 324篇 |
2002年 | 229篇 |
2001年 | 198篇 |
2000年 | 132篇 |
1999年 | 132篇 |
1998年 | 111篇 |
1997年 | 97篇 |
1996年 | 80篇 |
1995年 | 93篇 |
1994年 | 68篇 |
1993年 | 65篇 |
1992年 | 50篇 |
1991年 | 55篇 |
1990年 | 29篇 |
1989年 | 37篇 |
1988年 | 43篇 |
1987年 | 26篇 |
1986年 | 28篇 |
1985年 | 35篇 |
1984年 | 14篇 |
1983年 | 17篇 |
1982年 | 23篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 21篇 |
1978年 | 9篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Decorin, a collagen-binding small proteoglycan, is considered to have a specific function in the organization or stability of the collagen network. Therefore, alteration of its molecular properties may be of pathophysiological relevance during the development of cartilage damage. It is shown here that normal cartilage from rabbit knee-joint contains glycosaminoglycan chain-bearing core protein fragments of 39, 23, and 18 kDa, each one amounting to approximately 5-6% of the intact decorin core protein. Continuous infusion of human recombinant interleukin-1 alpha for 14 days (200 ng/day) into a knee-joint led in condylar cartilage to a reduction in the amount of intact core protein from 2 micrograms/mg wet tissue to about 1.1 micrograms/mg. The increase in its quantity found after infusion of heat-inactivated interleukin-1 was not statistically significant. The concentration of all three core protein fragments became reduced to a similar extent as the intact core protein under the influence of the cytokine, and additional fragments were not found. Surprisingly, there was a much smaller response to interleukin-1-treatment in patellar cartilage. 相似文献
92.
Gd-BOPTA增强MRI对小肝癌的诊断价值 总被引:6,自引:0,他引:6
目的 比较Gd BOPTA增强MRI与MRI平扫、Gd DTPA动态增强MRI在诊断小肝癌 (SHCC)方面的差异 ,进一步提高小肝癌检出率和诊断准确性并观察其不良反应。资料与方法 手术或穿刺病理证实为SHCC患者 2 5例。采用GESigna 1.5T磁共振扫描仪。行SE序列T1WI、FSE序列T2 WI及Gd DTPA快速动态增强多期扫描。Gd BOPTA增强扫描亦采用静脉团注快速动态增强扫描 (同Gd DTPA) ,并在团注后 15min、6 0min行SE序列T1WI和FMPSPGR序列T1WI扫描各 1次。观察MRI平扫、Gd DTPA快速动态增强和Gd BOPTA增强扫描及延迟扫描对病灶的检出率、包膜显示情况以及病灶的强化特征并行统计学分析。观察其不良反应。结果 2 5例患者共发现病灶4 2个。对SHCC病灶的检出率 ,MRI平扫为 6 9.0 5 % ,Gd DTPA增强为 85 .71% ,Gd BOPTA增强 (动态 延迟 )为95 .2 4 % ,和Gd DTPA增强之间无统计学差异 ,和MRI平扫有统计学意义。病理检查发现 30个病灶有包膜。Gd BOPTA增强对SHCC包膜的显示 ... 相似文献
93.
经胸小切口在食管癌切除手术中的应用 总被引:3,自引:0,他引:3
目的探讨经胸小切口治疗食管癌手术的地位和可行性。方法对132例不同分期的食管癌行经胸小切口根治性手术,全部采用颈部吻合。结果切口平均长度13.0±2.0 cm,开关胸时间、开胸时出血量、术后伤口疼痛、呼吸功能受限及患肢活动等方面有显著差异,在手术时间、淋巴结清扫、术中出血及术后胸腔引流和常规手术无差异。结论经胸小切口食管癌根治手术安全、可行,并且有创伤小、恢复快等优点,便于推广应用。 相似文献
94.
目的 探讨阴茎折断伤的病因和诊治。方法 对2l例阴茎折断伤的临床资料进行回顾性分析。结果 致伤原因以粗暴性交13例,手淫5例,跌伤、撞击伤各l例,拒绝说明原因l例。B超确诊12例,阴茎海绵体造影确诊l例。12h内手术13例,超过12h手术3例,保守治疗5例。12h内手术组有2例发生阴茎白膜硬结,术后性功能正常;超过12h手术组和保守治疗组各有l例和2例并发阴茎硬结、阴茎成角畸形和勃起功能障碍。结论 阴茎折断致伤原因以粗暴性交和手淫为主;B超检查是诊断阴茎折断首选方法;早期手术能减少其并发症的发生;术中采用纵行小切口容易准确找到白膜破裂位置,且创伤小,适于临床应用。 相似文献
95.
准分子激光角膜原位磨镶术治疗近视合并中度以上散光疗效观察 总被引:1,自引:0,他引:1
目的 :评价小光斑飞点扫描准分子激光系统应用于准分子激光原位角膜磨镶术 (LASIK)治疗近视合并中度以上散光的疗效。 方法 :对 96例患者 14 4只眼按术前屈光度分成三组 ,Ⅰ组 75只眼 ,近视 0~ - 6D ,散光 - 2~ - 4DC ;Ⅱ组 5 7只眼 ,近视 - 6 .2 5~ 10 .0 0D ,散光 - 2~ - 4DC。Ⅲ组 12只眼 ,近视 - 10 .2 5D以上 ,散光 - 2~- 4DC ;术后随访半年以上 ,并将结果进行比较分析。 结果 :术后 1个月裸眼视力达到 0 .6以上者 ,Ⅰ组为5 .3% ,Ⅱ组为 15 .8% ,Ⅲ组为 6 6 .7% ;术后 1个月裸眼视力达到 1.0以上者 ,Ⅰ组为 94 .7% ,Ⅱ组为 84 .2 % ,Ⅲ组为 33.3%。术后半年裸眼视力达到 0 .6以上者 ,Ⅰ组为 4 % ,Ⅱ组为 14 % ,Ⅲ组为 75 % ;术后半年裸眼视力达到 1.0以上者 ,Ⅰ组为 96 % ,Ⅱ组为 86 % ,Ⅲ组为 2 5 %。术后屈光度在± 1.0D以内者 ,Ⅰ组中为 8% ,Ⅱ组为 14 % ,Ⅲ组为 5 8.3%。术后屈光度在± 0 .5 0D以内者 ,Ⅰ组为 92 % ,Ⅱ组为 86 % ,Ⅲ组为 4 1.7%。术后散光度在± 1.0DC以内者 ,Ⅰ组为 8% ,Ⅱ组为 10 .5 % ,Ⅲ组为 5 0 %。术后散光度在± 0 .5 0DC以内者 ,Ⅰ组为 92 % ,Ⅱ组为 89.5 % ,Ⅲ组为 5 0 %。平均实际切削区直径为 (8.0 2± 0 .0 6 9)mm。 结论 :使用小光斑飞点显像LASIK治疗低 相似文献
96.
Sergey M. Kipriyanov Gerhard Moldenhauer Melvyn Little 《Journal of immunological methods》1997,200(1-2):69-77
We have investigated the effect of growth and induction conditions on the production of soluble single-chain Fv antibody fragments in Escherichia coli under the control of wt lac promoter. The scFv was directed into the periplasmic space by a pelB leader sequence. Addition of sucrose to the medium gave a 15–25-fold increase in the yield of soluble scFv-phOx (3.0 mg/l) for bacterial shake-tube cultures and an increase of 80–150-fold (16.5 mg/l) for shake-flask cultures. Using flask culture in the presence of 0.4 M sucrose, a significant amount of scFv was released into the medium. We found that the scFv could be made to accumulate in the periplasm or be secreted into the medium by simply changing the incubation conditions and the concentration of the inducer. The ratio between soluble antibody fragments and insoluble scFv aggregates proved to be dependent on the strength of the promoter. Lowering the incubation temperature below 20°C had no effect on the yield of soluble antibody fragments in the periplasm, but they were no longer secreted into the medium. An example of high level production in shake-flask cultures and one-step purification by immobilized metal affinity chromatography (IMAC) is described for a soluble scFv specific for the T cell surface antigen CD3. The biological activity of the purified anti-CD3 scFv was demonstrated by flow cytometry. This method should be especially useful for the functional screening of a large number of clones in small-scale cultures. 相似文献
97.
李绍芝 《山东中医药大学学报》1990,(1)
采用超声心动图对43例细脉者左心室舒缩功能进行了检测,并以26例滑脉和30例平脉作为对照组,发现细脉者8项左心室舒缩功能指标与各对照组比较有非常显著性差别(P>0.01)。说明细脉者具有左心室收缩功能和舒张功能的异常.左心室舒缩功能的减退是细脉产生的重要原因之一。不同原因的细脉者左心室舒缩功能的差别无显著性(P>0.05),揭示不同原因的细脉其产生的机理存在着同一性。 相似文献
98.
目的观察干扰素γ(IFN-γ)诱导供者(C57BL/6小鼠)脾树突细胞(DC)表达吲哚胺2,3双加氧酶(IDO)的情况;研究受者(BalB/c小鼠)小肠移植术前输注高表达IDO的供者DC对排斥反应的抑制作用。方法用IFN-γ诱导供者DC表达IDO;半定量逆转录聚合酶链反应、免疫印迹法及毛细管电泳法检测IDO表达水平及活性,混合淋巴细胞培养(MLR)测定IDO刺激T细胞增殖的能力。利用小鼠异位小肠移植模型,设单纯移植组、DC输注移植组(术前输注供者脾DC 2×10~6个)及诱导DC输注移植组(术前输注经IFN-γ诱导的供者脾DC 2×10~6个),术后观察移植肠存活时间并行病理学检查。结果经IFN-γ诱导的脾DC IDO分子mRNA转录水平(相对量)、IDO蛋白表达水平(相对量)及培养液中犬尿氨酸浓度分别为(1.23±0.02)、(2.74±0.01)以及(76.52±0.44)μmol/L,未经IFN-γ诱导的脾DC分别为(1.05±0.05)、(1.40±0.17)及(43.31±0.48)μmol/L,前者显著增强(P<0.01)。脾DC对同种T细胞增殖的刺激作用在IFN-γ诱导后减弱,在加入IDO的特异性抑制剂后增强。输注诱导DC移植组移植肠中位存活时间(12 d)较单纯移植组(6 d)及输注DC移植组(7.5 d)显著延长(P<0.01),而移植肠病理分级显著性降低(P<0.05)。结论IFN-γ可诱导小鼠脾DC高表达活性的IDO,后者可减弱DC刺激T细胞增殖的能力。受者术前输注高表达IDO的供者DC能够诱导针对供者的特异性免疫耐受而减轻排斥反应。 相似文献
99.
Oskar Meggeneder 《Zeitschrift fur Gesundheitswissenschaften》2007,15(2):101-107
In a small company, the whole company culture, including the management style, is dominated by the owner. The management culture
in small companies and above all the management style of the owner determine the chances of successfully introducing workplace
health promotion (WHP). For this reason a typology was developed that describes the management personalities who affect the
company culture in small enterprises. This provides a guide to the possible success of WHP in connection with the management
style. Although a summary of the management and corporate culture of small companies in a few categories cannot show the variety
of social reality, it can provide orientation. The typical categories of company social order (a mixture of ownership and
leadership) in small and medium-sized enterprises are given below. Furthermore, there is an assessment of what the chances
of realising workplace health promotion are in each type of company. Small and medium-sized companies (SME) have a number
of organisational characteristics which are just ideal for the introduction and implementation of workplace health promotion.
The work of the employer and employees is often the same. Information in the company is generally comprehensive and easily
available. The lack of information which employees often complain about in large companies is not a problem. There is a good
flow of communication. Small companies have a flat hierarchy that enables participation, the essential requirement for WHP.
There is a close social relationship between the company head and the workforce, although it must be said that this closeness
can be dangerous, particularly if it is misused as complete social control. The readiness to implement Workplace Health Promotion
(WHP) in SME and the degree of success depends largely on the personality of the company manager and the style of leadership.
Considering the importance of a manager’s personality for WHP in SME, modules and instruments to assist company owners and
managers in SME are to be developed. On behalf of and in co-operation with the Austrian Network for Workplace Health Promotion
several modules have been introduced to assist owners and managers of SMEs. 相似文献
100.
The purpose of this study is to describe the characteristic computed tomographic (CT) signs of small bowel perforation after
blunt abdominal trauma and to evaluate their sensitivity. Nineteen preoperative CT scans were obtained from 16 patients with
surgically proven small bowel rupture secondary to blunt abdominal trauma. Only the CT findings described in the original
CT reports were used. Eleven of 19 CT scans (58 %) had findings that were unequivocal for bowel rupture (i.e., extraluminal
air and/or extravasation of oral contrast medium). Seven CT scans (37 %) had findings that were suggestive of severe small
bowel injury (i.e., focal small bowel wall thickening and/or free peritoneal fluid without other accompanying organ injuries).
In all, 95 % of cases of small bowel rupture had either pathognomonic or suggestive CT findings. One CT scan did not demonstrate
small bowel wall thickening, although a hemoperitoneum was present. CT is a sensitive method for suggesting severe small bowel
injury and rupture secondary to blunt abdominal trauma. 相似文献