全文获取类型
收费全文 | 13491篇 |
免费 | 1323篇 |
国内免费 | 406篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 198篇 |
妇产科学 | 1825篇 |
基础医学 | 2138篇 |
口腔科学 | 147篇 |
临床医学 | 1059篇 |
内科学 | 1154篇 |
皮肤病学 | 87篇 |
神经病学 | 473篇 |
特种医学 | 247篇 |
外国民族医学 | 5篇 |
外科学 | 1425篇 |
综合类 | 2230篇 |
现状与发展 | 1篇 |
一般理论 | 3篇 |
预防医学 | 961篇 |
眼科学 | 110篇 |
药学 | 896篇 |
7篇 | |
中国医学 | 771篇 |
肿瘤学 | 1415篇 |
出版年
2024年 | 23篇 |
2023年 | 148篇 |
2022年 | 272篇 |
2021年 | 561篇 |
2020年 | 557篇 |
2019年 | 477篇 |
2018年 | 415篇 |
2017年 | 545篇 |
2016年 | 607篇 |
2015年 | 530篇 |
2014年 | 880篇 |
2013年 | 955篇 |
2012年 | 769篇 |
2011年 | 876篇 |
2010年 | 694篇 |
2009年 | 616篇 |
2008年 | 639篇 |
2007年 | 671篇 |
2006年 | 581篇 |
2005年 | 518篇 |
2004年 | 464篇 |
2003年 | 439篇 |
2002年 | 355篇 |
2001年 | 302篇 |
2000年 | 241篇 |
1999年 | 235篇 |
1998年 | 181篇 |
1997年 | 143篇 |
1996年 | 173篇 |
1995年 | 197篇 |
1994年 | 131篇 |
1993年 | 145篇 |
1992年 | 100篇 |
1991年 | 113篇 |
1990年 | 84篇 |
1989年 | 94篇 |
1988年 | 78篇 |
1987年 | 76篇 |
1986年 | 50篇 |
1985年 | 48篇 |
1984年 | 37篇 |
1983年 | 24篇 |
1982年 | 29篇 |
1981年 | 32篇 |
1980年 | 25篇 |
1979年 | 24篇 |
1978年 | 24篇 |
1977年 | 9篇 |
1973年 | 6篇 |
1970年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
中西医结合治疗妊娠期肝内胆汁淤积症初探 总被引:1,自引:0,他引:1
目的 评估复方丹参注射液联合熊去氧胆酸治疗妊娠期肝内胆汁淤积症的临床疗效及对新生儿预后的影响。 相似文献
82.
植入后全胚胎培养的培养基pH值改变对大鼠胚胎生长发育的影响 总被引:3,自引:0,他引:3
目的 探讨植入后全胚胎培养培养基最适pH值。方法 分离 9.5天龄Wistar大鼠胚胎 ,分别在实验组 (即不同pH :5 .5 ,6 .0 ,6 .5 ,7.0 ,7.5 ,8.0 ,8.5 ,9.0 )和对照组 (pH为 8.2 )的培养基 (1 0 0 %大鼠即刻离心血清 )中体外旋转培养4 8小时 ,观察pH值的改变对胚胎生长发育的影响。结果 与对照组比较 ,当培养基pH为 6 .5、6 .0和 9.0时培养胚胎的生长发育明显受到影响 (P <0 .0 5 ) ,胚胎畸形率和死亡率增高 (P <0 .0 5 )。当培养基pH为 5 .5时 ,培养胚胎死亡率达1 0 0 %。结论 全胚胎培养培养基pH条件改变 (过低或过高 )能够影响培养胚胎的生长发育。植入后全胚胎培养培养基最适pH值为 7.5~ 8.2。 相似文献
83.
目的:评价一期后、前路手术治疗发育性颈椎管狭窄合并巨大椎间盘突出的特点及疗效。方法:回顾分析2002年2月至2006年1月接受该术式的21例患者的临床资料,对手术前后临床表现、JOA评分、MRI影像变化以及术后神经功能改善率及并发症进行总结分析。结果:术后未发生神经系统症状加重、感染及内固定失效等并发症。获得1年以上随访者21例,平均随访时间为29.2个月,术后3个月、12个月时神经功能改善率分别为:58%、66%;16例获得2年以上随访者神经功能改善率为71%。结论:一期后、前路手术治疗发育性颈椎管狭窄合并巨大椎间盘突出可缩短治疗周期,相对节省治疗费用,同时解除了硬膜囊前、后方的压迫,减压彻底,疗效满意。 相似文献
84.
腹腔镜下处理输卵管积水对体外受精胚胎移植结局的影响 总被引:3,自引:2,他引:1
目的探讨腹腔镜下处理输卵管积水对体外受精胚胎移植(in vitro fertilization and embryo transfer, IVF-ET)结局的影响.方法 2002~2005年在我院行IVF-ET伴输卵管积水的53例分3个研究组:①未处理组17例,仅行IVF-ET,未对积水进行处理;②直接切除组17例,行IVF-ET术前在腹腔镜下处理输卵管积水;③失败后切除组19例,IVF-ET失败后腹腔镜下处理输卵管积水后再行IVF-ET.结果未处理组新鲜移植周期妊娠率15.8%(3/19),解冻周期妊娠率10.5%(2/19),平均周期妊娠率13.2%(5/38),累积活胎率17.6%(3/17);直接切除组分别为36.8%(7/19),23.1%(3/13),30.3%(10/32),41.7%(8/17);失败后切除组分别为16.7%(2/12),58.3%(14/24),44.4%(16/36),73.7%(14/19).失败后切除组的解冻周期妊娠率、平均周期妊娠率及累积活胎率均高于未处理组(χ2=10.374,P=0.001;χ2=8.903,P=0.003;χ2=11.305,P=0.001),直接切除组平均周期妊娠率及累积活胎率呈高于未处理组的趋势(χ2=3.377,P=0.066;χ2=3.360,P=0.067).结论输卵管积水降低IVF-ET的妊娠率,妊娠结局不良,腹腔镜下处理输卵管积水后再行IVF-ET提高妊娠率,获得良好的妊娠结局. 相似文献
85.
从彭勃治"暗瘀"说探索肝纤维化的中医论治 总被引:2,自引:0,他引:2
系统阐述了彭勃治"暗瘀"说的基本内涵,并以此学说为基础进一步提出了"肝纤维化期相当于暗瘀期"的新观点。并解决了肝纤维化的中医病名、病因病机、辨证论治等诸多难题,从而使肝纤维化的中医论治有了自身的系统的中医基础理论的支持和准确的切入点,并有望取得突破。 相似文献
86.
Microcystin-LR is the most frequently studied cyclic heptapeptide produced by different genera of cyanobacteria and is hepatotoxic to livestock and human populations. The adverse effects of microcystin-LR on morphology and cytoskeletal elements in different stages of early embryonal development have been studied in vitro. Embryos and whole embryo cultures have been exposed to microcystin-LR (10–100 μM). Actin filaments were visualized by fluorescence staining and the microtubular network labelled by immunostaining. Growth, development and cytoskeleton organization of the embryos embedded in zona pellucida are not affected by microcystin-LR in concentrations up to 100 μM, while whole embryo cell cultures are affected by the presence of microcystin-LR in the culture medium. High microcystin-LR concentrations (100 μM) cause cells to be detached and destroyed, while lower concentrations (10–20 μM) profoundly affect actin and microtubule organization. These effects are confirmed also by the presence of transformed microcystin-LR in all the media at the lowest concentrations. It seems that the changes to the cells are far more serious than that expressed in cell morphology. From our experiments we conclude that the presence of zona pellucida is an effective way of embryo protection against xenobiotics like microcystin-LR. 相似文献
87.
AMAL KANBOUR-SHAKIR DAVID T. ARMSTRONG ANNE ROULEAU HEINZ W. KUNZ THOMAS J. GILL 《American journal of reproductive immunology (New York, N.Y. : 1989)》1995,33(5):367-372
PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization. 相似文献
88.
Fragmentation is frequently observed in animal and human embryosobtained via in-vitro fertilization (IVF), and is known to beassociated with decreased pregnancy rates and poor survivalfollowing cryopreservation. We postulate that embryo fragmentationis a consequence of activated programmed cell death (PCD) andsubsequent apoptosis and discuss evidence of morphological,histological and biochemical features compatible with the occurrenceof PCD in preimplantation embryos. If PCD is an underlying causeof the high incidence of the fragmentation seen in human pre-embryos,it remains to be determined whether this is reflective of thenatural incidence of lethal chromo somes in the human populationor due to the IVF procedure and culture conditions. 相似文献
89.
在生活节奏不断加快,竞争激烈的当今社会,大学生群体中不同程度地存在人际交往困难,影响了各种适应社会需求和自我发展能力的培养。通过搭建体验式沟通平台,形成一种团结友爱、朝气蓬勃的氛围,将有利于大学生形成和发展健康的个性品质,提高大学生的人际交往能力。 相似文献
90.
A supportive approach to care for women during the second stage of labor that primarily relies on the laboring woman's involuntary expulsive urges has been advocated. We aimed to learn about the clinical circumstances surrounding the caregiver shift from being primarily supportive to directing women regarding their bearing-down efforts. This research analyzed the communications of 10 birth attendants and women during the expulsive phase of labor using videotapes recorded from two studies carried out between 1986 and the present. The occasions when a birth attendant shifted verbalizations were identified, and categories of the rationales that may have influenced the modification in caregiver behavior were developed. Birth attendants most frequently provided directions to help the woman push effectively, that is, to focus the woman's bearing-down efforts during maternal distress, fatigue, fear, and pain to expedite the labor process (38% of the occasions of caregiver change in verbalizations). The next most frequent clinical situations when caregivers offered directions about "pushing" were diminished urge to bear-down with epidural analgesia (10%), routine arbitrary practices (9% caregiver and 6% by supportive companion), and fetal distress (<1%). A category of "supportive direction" (20%) was identified. This care strategy has not been previously reported. It combined direction with support in a way that was supportive rather than overriding the woman's involuntary efforts. 相似文献