全文获取类型
收费全文 | 4887篇 |
免费 | 428篇 |
国内免费 | 131篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 126篇 |
妇产科学 | 70篇 |
基础医学 | 687篇 |
口腔科学 | 137篇 |
临床医学 | 481篇 |
内科学 | 833篇 |
皮肤病学 | 96篇 |
神经病学 | 334篇 |
特种医学 | 162篇 |
外国民族医学 | 1篇 |
外科学 | 536篇 |
综合类 | 325篇 |
现状与发展 | 1篇 |
预防医学 | 375篇 |
眼科学 | 132篇 |
药学 | 429篇 |
1篇 | |
中国医学 | 81篇 |
肿瘤学 | 591篇 |
出版年
2024年 | 6篇 |
2023年 | 79篇 |
2022年 | 214篇 |
2021年 | 219篇 |
2020年 | 149篇 |
2019年 | 197篇 |
2018年 | 180篇 |
2017年 | 161篇 |
2016年 | 176篇 |
2015年 | 201篇 |
2014年 | 232篇 |
2013年 | 262篇 |
2012年 | 333篇 |
2011年 | 350篇 |
2010年 | 186篇 |
2009年 | 163篇 |
2008年 | 247篇 |
2007年 | 253篇 |
2006年 | 229篇 |
2005年 | 268篇 |
2004年 | 201篇 |
2003年 | 169篇 |
2002年 | 152篇 |
2001年 | 102篇 |
2000年 | 93篇 |
1999年 | 78篇 |
1998年 | 42篇 |
1997年 | 49篇 |
1996年 | 32篇 |
1995年 | 29篇 |
1994年 | 30篇 |
1993年 | 25篇 |
1992年 | 44篇 |
1991年 | 49篇 |
1990年 | 28篇 |
1989年 | 25篇 |
1988年 | 29篇 |
1987年 | 24篇 |
1986年 | 22篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1979年 | 7篇 |
1976年 | 4篇 |
1974年 | 5篇 |
1972年 | 8篇 |
1970年 | 8篇 |
1969年 | 8篇 |
1939年 | 4篇 |
排序方式: 共有5446条查询结果,搜索用时 15 毫秒
91.
Ying Mai Kung 《The Journal for Nurse Practitioners》2013,9(2):87-92
Influenza vaccination is recommended for all health care personnel (HCP), but immunization rates for this group continue to be suboptimal. This study explores relationships between individual characteristics, beliefs, knowledge, attitudes, and vaccination behavior through 2 surveys conducted at a university health center. The findings suggest that HCP who were vaccinated the year before, intended to be vaccinated next year, believed influenza vaccination was important, and were more knowledgeable are more likely to receive a vaccine. 相似文献
92.
Yahya A. Al-Zahrani Sameer E. Al-Harthi Lateef M. Khan Hani M. El-Bassossy Sherif M. Edris Mai A. Alim A. Sattar 《Saudi Pharmaceutical Journal》2015,23(5):487-498
The anti-anginal effects of allopurinol were assessed in experimental model rats of angina and their effects were evaluated with amlodipine. In the vasopressin-induced angina model, oral administration of allopurinol in dose of 10 mg/kg revealed remarkably analogous effects in comparison with amlodipine such as dose-dependent suppression of vasopressin-triggered time, duration and severity of ST depression. In addition, allopurinol produced dose dependent suppression of plasma Malondialdehyde (MDA) level, systolic blood pressure, cardiac contractility and cardiac oxygen consumption; while in contrast, amlodipine minimally suppressed the elevation of plasma MDA level. Endothelial NO synthase (eNOS) expression, serum nitrate were strikingly increased, however lipid profile was significantly reduced. Seemingly, allopurinol was found to be more potent than amlodipine – a calcium channel antagonist. To conclude, it was explicitly observed and verified that on the ischemic electrocardiography (ECG) changes in angina pectoris model in rats, allopurinol exerts a significant protective effects, reminiscent of enhancement of vascular oxidative stress, function of endothelial cells, improved coronary blood flow in addition to the potential enhancement in myocardial stress. Moreover, our findings were in conformity with several human studies. 相似文献
93.
Shereen M. Assaf Mai Subhi Khanfar Ahmed Bassam Farhan Iyad Said Rashid Adnan Ali Badwan 《Pharmaceutical development and technology》2019,24(6):761-774
It was aimed to investigate the compressibility, compactibility, powder flow and tablet disintegration of a new excipient comprising magnesium (Mg) silicate co-processed (5%–85% w/w) onto chitin, microcrystalline cellulose (MCC) and starch as the hydrophilic polymers of interest. Initially, the mechanism of tablet disintegration was studied by measuring water infiltration rate, moisture sorption, swelling capacity and hydration ability. Moreover, the powders compression behavior was carried out by applying Kawakita model of compression analysis in addition to porosity and radial tensile strength measurements. In vitro drug release of compacts made of 400?mg ibuprofen and 300?mg of the hydrophilic polymers containing 30% w/w Mg silicate co-precipitate was investigated in phosphate buffer (pH 7.8). This work demonstrated that the incorporation of Mg silicate to the hydrophilic polymers lead to the improvement of powder flowability, compactibility, stability (with regard to storage conditions), compacts crushing strength, and disintegration time in addition to faster drug release. The overall findings are practically advantageous in the context of finding a low cost and multifunctional co-processed excipient of natural origins. 相似文献
94.
95.
Endocrine abnormalities in HIV‐infected women are associated with peak viral load – the Children and Women: AntiRetrovirals and Markers of Aging (CARMA) Cohort 下载免费PDF全文
96.
目前专门对化学突触硬件实现的研究较少,采用FPGA芯片技术硬件实现化学突触,对神经元网络的硬件实现具有重要价值。运用DSP Builder软件,对以Hodgkin-Huxley神经元为突触前神经元和突触后神经元的化学突触数学模型进行建模。在DSP Builder模型的基础上,将化学突触的DSP Builder模型进行合理的拆分,然后分别将各个模块在FPGA所对应的软件环境下进行编译运行,最后下载到FPGA核心芯片中,硬件实现5种基于不同机理的化学突触模型。采用相关系数法,对仿真结果和硬件结果在同一个周期内的突触前神经元动作电位、突触后神经元动作电位以及突触电流的幅值进行对比,验证硬件实现的准确性。5种硬件实现的化学突触均可以较好地传递动作电位,但是各个模型消耗资源不同,模型3所消耗的内部乘法器资源(69%),约为模型5资源(31%)的2倍,表明突触模型数学复杂度越高,其消耗的乘法器资源越多。相关系数法的对比结果显示,模型3相关度最高,为0.791 3,模型4相关度最低,为0.693 5。虽然模型3数学复杂度高、硬件资源消耗多,但是其表现的生物性最好。硬件实现的5种突触模型均能较好地呈现化学突触的单向传递性,其中模型5硬件资源消耗少、相关度高,建议以其作为化学突触硬件实现的首选。 相似文献
97.
Mai Leander Erik Lampa Christer Janson Kurt Sv?rdsudd Monica Uddenfeldt Anna Rask-Andersen 《Upsala journal of medical sciences》2012,117(1):57-66
People with asthma suffer from impaired health-related quality of life (HRQL), but the determinants of HRQL among asthmatics are not completely understood. The aim of this investigation was to study determinants of low HRQL in asthmatics and to study whether the determinants of HRQL differ between sexes and age groups. A cohort of three age groups in Sweden was investigated in 1990 using a questionnaire with focus on respiratory symptoms. To study quality of life, the generic instrument Gothenburg Quality of Life was used. The participants were also investigated with interviews, spirometry, and allergy testing. Asthma was diagnosed in 616 subjects. Fifty-eight per cent (n = 359) of the subjects were women; and 24% were smokers, 22% ex-smokers, and 54% were non-smokers. Women were more likely than men to report poor health-related quality of life. Respiratory symptoms severity was another independent determinant of a lower quality of life as well as airway responsiveness to irritants. Current and former smokers also reported lower quality of life. Finally, absenteeism from school and work was associated with lower quality of life. Factors such as sex, smoking habits, airway responsiveness to irritants, respiratory symptom severity, allergy, and absenteeism from school and work were associated with low HRQL in asthmatics. 相似文献
98.
Mai Kelany John S. Pickersgill Namir Al Hasso Adie Viljoen Nancy van Bijlen 《Hemoglobin》2016,40(5):345-348
We present a case of a novel pathogenic variant, Hb Kalavasos [α91(FG3)Leu→His (α2); HBA2: c.275T?>?A; p.Leu92His (NM_000517.4)]; this codon was previously numbered 91 on the α2-globin gene that was discovered following routine Hb A1c testing on a 65-year-old female of Cypriot origin. The band, seen by high performance liquid chromatography (HPLC) but not capillary zone electrophoresis (CZE), was confirmed as a hitherto undescribed a chain variant, that we have named Hb Kalavasos for the Cypriot village of family origin of the proband. 相似文献
99.
Mai Alhajlan Moayad Alhariri Abdelwahab Omri 《Antimicrobial agents and chemotherapy》2013,57(6):2694-2704
We investigated the efficacy and safety of liposomal clarithromycin formulations with different surface charges against clinical isolates of Pseudomonas aeruginosa from the lungs of cystic fibrosis (CF) patients. The liposomal clarithromycin formulations were prepared by the dehydration-rehydration method, and their sizes were measured using the dynamic-light-scattering technique. Encapsulation efficiency was determined by microbiological assay, and the stabilities of the formulations in biological fluid were evaluated for a period of 48 h. The MICs and minimum bactericidal concentrations (MBCs) of free and liposomal formulations were determined with P. aeruginosa strains isolated from CF patients. Liposomal clarithromycin activity against biofilm-forming P. aeruginosa was compared to that of free antibiotic using the Calgary Biofilm Device (CBD). The effects of subinhibitory concentrations of free and liposomal clarithromycin on bacterial virulence factors and motility on agar were investigated on clinical isolates of P. aeruginosa. The cytotoxicities of the liposome preparations and free drug were evaluated on a pulmonary epithelial cell line (A549). The average diameter of the formulations was >222 nm, with encapsulation efficiencies ranging from 5.7% to 30.4%. The liposomes retained more than 70% of their drug content during the 48-h time period. The highly resistant strains of P. aeruginosa became susceptible to liposome-encapsulated clarithromycin (MIC, 256 mg/liter versus 8 mg/liter; P < 0.001). Liposomal clarithromycin reduced the bacterial growth within the biofilm by 3 to 4 log units (P < 0.001), significantly attenuated virulence factor production, and reduced bacterial twitching, swarming, and swimming motilities. The clarithromycin-entrapped liposomes were less cytotoxic than the free drug (P < 0.001). These data indicate that our novel formulations could be a useful strategy to enhance the efficacy of clarithromycin against resistant P. aeruginosa strains that commonly affect individuals with cystic fibrosis. 相似文献
100.
Efficacy of exenatide on weight loss,metabolic parameters and pregnancy in overweight/obese polycystic ovary syndrome 下载免费PDF全文