全文获取类型
收费全文 | 18278篇 |
免费 | 1847篇 |
国内免费 | 843篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 291篇 |
妇产科学 | 368篇 |
基础医学 | 1995篇 |
口腔科学 | 403篇 |
临床医学 | 2020篇 |
内科学 | 2740篇 |
皮肤病学 | 558篇 |
神经病学 | 1078篇 |
特种医学 | 675篇 |
外国民族医学 | 14篇 |
外科学 | 2148篇 |
综合类 | 2932篇 |
现状与发展 | 3篇 |
一般理论 | 3篇 |
预防医学 | 1229篇 |
眼科学 | 430篇 |
药学 | 1861篇 |
18篇 | |
中国医学 | 764篇 |
肿瘤学 | 1312篇 |
出版年
2024年 | 55篇 |
2023年 | 234篇 |
2022年 | 637篇 |
2021年 | 876篇 |
2020年 | 698篇 |
2019年 | 615篇 |
2018年 | 591篇 |
2017年 | 586篇 |
2016年 | 613篇 |
2015年 | 810篇 |
2014年 | 990篇 |
2013年 | 1072篇 |
2012年 | 1526篇 |
2011年 | 1491篇 |
2010年 | 1132篇 |
2009年 | 878篇 |
2008年 | 1059篇 |
2007年 | 1123篇 |
2006年 | 1021篇 |
2005年 | 830篇 |
2004年 | 688篇 |
2003年 | 657篇 |
2002年 | 575篇 |
2001年 | 394篇 |
2000年 | 335篇 |
1999年 | 253篇 |
1998年 | 125篇 |
1997年 | 117篇 |
1996年 | 94篇 |
1995年 | 82篇 |
1994年 | 70篇 |
1993年 | 63篇 |
1992年 | 95篇 |
1991年 | 62篇 |
1990年 | 76篇 |
1989年 | 54篇 |
1988年 | 44篇 |
1987年 | 35篇 |
1986年 | 46篇 |
1985年 | 41篇 |
1984年 | 25篇 |
1983年 | 16篇 |
1982年 | 18篇 |
1981年 | 12篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 14篇 |
1976年 | 14篇 |
1975年 | 14篇 |
1974年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
141.
采用位于α3′HVR同侧与成人型多囊肾病基因(PKD1)更加接近的pGGG1及另一侧的24-1和218EP6等探针对正常人基因组DNA进行限制性片段长度多态性(RELP)分析,分别检测各等位片段的频率,在此基础上,应用这三个基因探针与3′HVR一起对2个成人型多囊肾病家系成员进行单体型分析,在这2个家系中,5个APKD患者的RFLP单体型被证明与PKD1基因相连锁,发现一个重组体,并检测出二个症状前个体。 相似文献
142.
Enterovirus 71 (EV71) is a highly infectious major causative agent of hand, foot, and mouth disease (HFMD) which could lead to severe neurological complications. There is currently no effective therapy against EV71. In this study, RNA interference (RNAi) is employed as a therapeutic approach for specific viral inhibition. Various regions of the EV71 genome were targeted for inhibition by chemically synthesized siRNAs. Transfection of rhabdomyosarcoma (RD) cells with siRNA targeting the 3'UTR, 2C, 3C, or 3D region significantly alleviated cytopathic effects of EV71. The inhibitory effect was dosage-dependent with a corresponding decrease in viral RNA, viral proteins, and plaque formations by EV71. Viral inhibition of siRNA transfected RD cells was still evident after 48 h. In addition, no significant adverse off-target silencing effects were observed. These results demonstrated the potential and feasibility for the use of siRNA as an antiviral therapy for EV71 infections. 相似文献
143.
Jin H Kang Y Xiao C Zhu K Ma Y Xie Q Ma J Xie Q He C Yang Z Sun Z Zhang X Chen M Zhang F Wang B 《Viral immunology》2005,18(3):539-548
Prime-boost strategy has been exhibited its potency to enhance immune responses, which would be important to the success to develop a vaccine against the foot-and-mouth disease virus (FMDV). An eukaryotic expression construct encoding the FMDV capsid VP1 protein with a recombinant VP1 protein or a commercial FMDV vaccine were tested in the prime-boost strategy in mice and cattle trials. The levels of induced specific antibodies, T cell proliferations, and DTH activities were significantly higher in the prime-boost groups than in those vaccinated with DNA, protein or FMDV vaccine alone. More importantly, the levels of neutralizing antibodies in the former groups were significantly higher than others and could last for at least four months in cattle trials. This study suggests that the prime-boost strategy significantly improves the effective immunity and may provide a longer protection against FMDV infection. 相似文献
144.
145.
Hitchcock AP Morin C Heng YM Cornelius RM Brash JL 《Journal of biomaterials science. Polymer edition》2002,13(8):919-937
Scanning transmission X-ray microscopy (STXM) is being developed as a new tool to study the surface chemical morphology and biointeractions of candidate biomaterials with emphasis on blood compatible polymers. STXM is a synchrotron based technique which provides quantitative chemical mapping at a spatial resolution of 50 nm. Chemical speciation is provided by the near edge X-ray absorption spectral (NEXAFS) signal. We show that STXM can detect proteins on soft X-ray transparent polymer thin films with monolayer sensitivity. Of great significance is the fact that measurements can be made in situ, i.e. in the presence of an overlayer of the protein solution. The strengths, limitations and future potential of STXM for studies of biomaterials are discussed. 相似文献
146.
147.
Antimicrobial agents played a miraculous role in the treatment of bacterial infections until resistant bacteria became widespread. Besides antimicrobial-resistant bacteria, many factors can influence the cure of infection. Nocardia infection may be a good example which is difficult to cure with antimicrobial agents alone. A 66-year-old man developed soft tissue infection of the right buttock and thigh. He was given prednisolone and azathioprine for pachymeningitis 3 months prior to admission. Despite surgical and antimicrobial treatment (sulfamethoxazole-trimethoprim), the infection spread to the femur and osteomyelitis developed. The case showed that treatment of bacterial infection is not always as successful as was once thought because recent isolates of bacteria are more often resistant to various antimicrobial agents, intracellular parasites are difficult to eliminate even with the active drug in vitro, and infections in some sites such as bone are refractory to treatment especially when the patient is in a compromised state. In conclusion, for the treatment of infections, clinicians need to rely on laboratory tests more than before and have to consider the influence of various host factors. 相似文献
148.
149.
Yum JH Kim S Lee H Yong D Lee K Cho SN Chong Y 《Journal of Korean medical science》2005,20(6):961-965
Respiratory isolates of Klebsiella pneumoniae in Korea during 2002-2003 were studied to determine the prevalence and types of extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated AmpC beta-lactamases (PABLs). ESBL-production was tested by double-disk synergy, and genotypes of beta-lactamases were determined by PCR and sequencing. ESBLs were detected in 28.4% of 373 isolates, and the most prevalent types were SHV-12 (63 isolates) and CTX-M-14 (9 isolates). Forty of 75 ESBL-producers (53.5%) also had PABLs: 21 isolates with CMY-2-like, 17 with DHA-1-like. Pulsed-field gel electrophoresis showed 19 types and 25 of 74 isolates had an identical pattern, indicating nosocomial spread. Dissemination of ESBL- and PABL-producing K. pneumoniae strains in Korea is a particular concern, as it limits the choice of antimicrobial agents for treatment of infections. 相似文献
150.
One of the major challenges in medical domain is the extraction of comprehensible knowledge from medical diagnosis data. In this paper, a two-phase hybrid evolutionary classification technique is proposed to extract classification rules that can be used in clinical practice for better understanding and prevention of unwanted medical events. In the first phase, a hybrid evolutionary algorithm (EA) is utilized to confine the search space by evolving a pool of good candidate rules, e.g. genetic programming (GP) is applied to evolve nominal attributes for free structured rules and genetic algorithm (GA) is used to optimize the numeric attributes for concise classification rules without the need of discretization. These candidate rules are then used in the second phase to optimize the order and number of rules in the evolution for forming accurate and comprehensible rule sets. The proposed evolutionary classifier (EvoC) is validated upon hepatitis and breast cancer datasets obtained from the UCI machine-learning repository. Simulation results show that the evolutionary classifier produces comprehensible rules and good classification accuracy for the medical datasets. Results obtained from t-tests further justify its robustness and invariance to random partition of datasets. 相似文献