全文获取类型
收费全文 | 7204篇 |
免费 | 550篇 |
国内免费 | 232篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 107篇 |
妇产科学 | 71篇 |
基础医学 | 727篇 |
口腔科学 | 123篇 |
临床医学 | 934篇 |
内科学 | 492篇 |
皮肤病学 | 48篇 |
神经病学 | 429篇 |
特种医学 | 117篇 |
外国民族医学 | 3篇 |
外科学 | 378篇 |
综合类 | 1079篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 1130篇 |
眼科学 | 29篇 |
药学 | 1452篇 |
7篇 | |
中国医学 | 633篇 |
肿瘤学 | 197篇 |
出版年
2024年 | 20篇 |
2023年 | 110篇 |
2022年 | 143篇 |
2021年 | 264篇 |
2020年 | 278篇 |
2019年 | 255篇 |
2018年 | 252篇 |
2017年 | 248篇 |
2016年 | 250篇 |
2015年 | 221篇 |
2014年 | 423篇 |
2013年 | 579篇 |
2012年 | 486篇 |
2011年 | 484篇 |
2010年 | 385篇 |
2009年 | 366篇 |
2008年 | 383篇 |
2007年 | 368篇 |
2006年 | 300篇 |
2005年 | 250篇 |
2004年 | 238篇 |
2003年 | 205篇 |
2002年 | 162篇 |
2001年 | 124篇 |
2000年 | 118篇 |
1999年 | 102篇 |
1998年 | 94篇 |
1997年 | 65篇 |
1996年 | 76篇 |
1995年 | 69篇 |
1994年 | 73篇 |
1993年 | 65篇 |
1992年 | 56篇 |
1991年 | 62篇 |
1990年 | 46篇 |
1989年 | 43篇 |
1988年 | 37篇 |
1987年 | 43篇 |
1986年 | 35篇 |
1985年 | 35篇 |
1984年 | 26篇 |
1983年 | 17篇 |
1982年 | 24篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1979年 | 27篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1976年 | 13篇 |
1974年 | 4篇 |
排序方式: 共有7986条查询结果,搜索用时 578 毫秒
81.
Adult rats emit 22 kHz ultrasonic vocalizations (USVs) in response to aversive stimuli, and these sounds are suggested to have communicative information among conspecifics. It is conceivable that social environment during development of rats has relevance to the emission of 22 kHz USVs. To examine the effects of social environment after weaning on production of stress-induced USVs, we compared the amount of emission of USVs among three groups of rats reared under different conditions after weaning. One group of rats was housed individually, and the other two groups were housed in pairs, in which social hierarchy of the pair was determined by social dominance-subordination relationships. The USVs were induced by acute mild somatic stimuli on the back and neck. Individually reared rats emitted much fewer USVs than pair-reared rats. In addition, socially subordinate rats emitted more USVs compared with socially dominant ones. These results suggest that not only social interaction but also the status in social hierarchy may play an important role in the process of the development of USVs induced by somatic stimuli. 相似文献
82.
R Arriagada H Mouriesse D Sarrazin R M Clark G Deboer 《International journal of radiation oncology, biology, physics》1985,11(10):1751-1757
This retrospective study involved 463 breast cancer patients treated by radiotherapy alone at the Princess Margaret Hospital and at the Institut Gustave-Roussy. These patients either had operable tumors, but were unfit for general anesthesia, or had inoperable tumors due to local contraindications to surgery. Results were analyzed according to tumor response, local recurrence rate, tumor size, tumor fixation, nodal fixation and tumor dose. Conventional statistical analysis of local control showed two significant factors: tumor dose and tumor size. Multivariate analysis permitted to define an "individual risk" (IR) of local recurrence according to three independent factors: tumor size, tumor fixation, and nodal fixation. It was shown that the IR was a good prognostic factor for local control. Increase in tumor dose gave a similar effect in the local recurrence relative risk for all the IR groups. According to the slope of the dose-effect curve, it was deduced that a dose increase of 15 Gy can decrease the relative risk of local recurrence 2-fold. In fact, it was shown that tumor dose was the most significant independent factor on local control, able to produce up to a 10-fold increase compared to 2-fold decrease for tumor size. If the IR of local recurrence is known, a theoretical predictive value on local control, taking into account the tumor dose, can be determined according to the present data. 相似文献
83.
Dr. O. N. Bershitskaya V. Ya. Izakov L. T. Lysenko J. L. Protsenko A. V. Trubetskoy 《Basic research in cardiology》1985,80(2):156-164
Summary The relationship heart rate-left ventricular pressure was investigated in the isolated canine heart perfused with constant pressure at different preloads. Rhythmical stimulation was performed with constant stimulus interval duration and with stimulus intervals randomly changed near the average value (150–200 stimuli in series).Correlation and dispersion function analysis show that rhythm dispersion had a negative inotropic effect which was independent of the preload of the ventricle in the range of 120–180 beat/min, but this dependence occurred with low rates of stimulation.This method is proposed for the assessment of contractility under conditions of heart rate variations (physiological and pathological arrhythmias). 相似文献
84.
Tang-Liu Diane D. -S. Liu Sandra 《Journal of pharmacokinetics and pharmacodynamics》1987,15(4):387-397
The differences in flurbiprofen disposition in the aqueous humor and the plasma were examined after systemic doses. Steady state plasma concentrations of flurbiprofen (20–60 g/mL) were achieved via intravenous infusion to albino rabbits. Flurbiprofen demonstrated linear systemic kinetics throughout the dosing range, with constant body clearance and unbound fraction in plasma. At steady state, aqueous humor drug concentrations depended on the corresponding plasma drug concentration. Two clearance terms—CLso, the systemic clearance to ocular tissues, and CLos, the ocular clearance to systemic circulation—were used. After systemic doses, the drug concentration in the aqueous humor was related to that in the plasma as well as to the ratio of these two clearances. Flurbiprofen was extensively bound to plasma proteins and showed limited ocular distribution; its CLso to CLso tratio was very small. Thus, the concentration of flurbiprofen in the aqueous humor after systemic doses was lower than that obtained after ophthalmic doses. A plasmapheresis technique was utilized to lower the plasma protein concentrations to 60% of normal levels. As a consequence, flurbiprofen demonstrated reduced aqueous humor protein concentrations, increased unbound fractions in the plasma and the aqueous humor, elevated aqueous humor drug concentrations, and elevated total body clearance. The unbound body clearance stayed unchanged. Our study indicated that a drug should present a significant CLso/CLos ratio in order to achieve therapeutic concentrations in the eye via systemic doses. The drug-protein binding kinetics can be different between the plasma and the aqueous humor circulations. Because the ocular compariment is very small compared to the overall systemic distribution of flurbiprofen, it has little effect on the steady state systemic concentrations. 相似文献
85.
[摘要] 目的 初步探索血清白蛋白水平与新型冠状病毒肺炎长期阳性患者病毒转阴之间的因果关系。方法?以病程超过30 d的轻型新型冠状病毒肺炎住院患者为研究对象,采集人口学信息、治疗策略、合并疾病、实验室检查指标信息,以发病后45 d内病毒累积转阴率为因变量,以发病后(30±3)d时的血清白蛋白水平为主要分析变量,以人口学信息、治疗策略、合并疾病、实验室检查结果等其他信息为协变量,采用限制立方样条回归-Cox比例风险回归模型探讨血清白蛋白水平对累积转阴率的影响。结果?共有189例患者纳入分析,其中101例在45 d内实现了病毒转阴。进一步分析发现,30 d时的血清白蛋白水平与45 d病毒累积转阴率之间存在相关性(P = 0.027)。当血清白蛋白<39 g/L时,低血清白蛋白水平是病毒转阴的危险因素,且血清白蛋白水平越低,风险比(hazard ritio, HR)越高,血清白蛋白越接近39 g/L,HR则越接近1;当血清白蛋白≥39 g/L时,血清白蛋白水平不再是病毒转阴的危险因素。结论?血清白蛋白水平与患者的病毒转阴密切相关,当血清白蛋白<39 g/L时,血清白蛋白水平越低,越不利于病毒转阴。因此,治疗过程中关注血清白蛋白变化,及时给予干预,可能有利于病毒转阴。 相似文献
86.
文化建设与党建工作之间存在着一定的关联,随着经济的不断发展,我国卫生管理体制改革也不断深入,在此过程中,对于高校附属医院文化建设和党建工作提出更高水平的要求。从医院层面来看,通过加强文化建设以及发展党建工作,能够有效提高医院的凝聚力,促进医院树立良好的形象、培养优秀的医护人员等。文化建设和党建工作息息相关,在医院管理与发展的过程中,两者之间相辅相成。文章在研究的过程中,采用访谈法、问卷调查法等方法,通过访谈法、问卷调查法对医院各个方面人员进行调查,根据调查结果总结高校附属医院文化建设和党建工作的关系。 相似文献
87.
面对医疗卫生事业改革的新形势、新任务,医院办公室应该更新观念,树立改革创新意识、大局意识、法制意识、市场竞争意识和以病人为中心的意识;积极参与医院改革、成本核算、组建医疗集团、建立医院信息系统、开拓医疗服务市场、参与市场竞争等医院重点工作;建立和协调好对内对外的关系,在医院改革与发展中发挥积极作用。 相似文献
88.
89.
90.
目的 建立广山楂Malus doumeri指纹图谱,测定各批次广山楂的“活血化瘀”药效学指标,探讨广山楂化学成分与活血化瘀功效的谱效关系。方法 采用HPLC法建立18批广山楂的指纹图谱。利用大鼠高脂模型,测定不同批次广山楂的“活血化瘀”药效学指标,包括高密度脂蛋白胆固醇(high density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇(low density lipoprotein cholesterin,LDL-C)、总胆固醇(total cholesterol,TC)、三酰甘油(triglyceride,TG)含量及血液流变学指标等。运用偏最小二乘回归法(partial least-square method regression,PLSR)、灰色关联度分析法,分析广山楂化学成分与活血化瘀药效指标间的谱效关系。结果 构建了广山楂的HPLC图谱,确定了6个共有峰,并指认了其中的2个共有峰(绿原酸、根皮苷)。活血化瘀实验表明,不同批次广山楂活血药效指标间具有明显差异,在标定的广山楂6个特征峰中,峰2~6与HDL-C呈正相关,峰1、5、6与LDL... 相似文献