全文获取类型
收费全文 | 9509篇 |
免费 | 880篇 |
国内免费 | 146篇 |
专业分类
耳鼻咽喉 | 783篇 |
儿科学 | 81篇 |
妇产科学 | 106篇 |
基础医学 | 714篇 |
口腔科学 | 459篇 |
临床医学 | 921篇 |
内科学 | 737篇 |
皮肤病学 | 130篇 |
神经病学 | 578篇 |
特种医学 | 178篇 |
外国民族医学 | 1篇 |
外科学 | 1143篇 |
综合类 | 1244篇 |
预防医学 | 2074篇 |
眼科学 | 51篇 |
药学 | 639篇 |
6篇 | |
中国医学 | 275篇 |
肿瘤学 | 415篇 |
出版年
2024年 | 16篇 |
2023年 | 165篇 |
2022年 | 356篇 |
2021年 | 395篇 |
2020年 | 341篇 |
2019年 | 380篇 |
2018年 | 439篇 |
2017年 | 362篇 |
2016年 | 330篇 |
2015年 | 346篇 |
2014年 | 775篇 |
2013年 | 726篇 |
2012年 | 646篇 |
2011年 | 694篇 |
2010年 | 591篇 |
2009年 | 510篇 |
2008年 | 513篇 |
2007年 | 524篇 |
2006年 | 430篇 |
2005年 | 327篇 |
2004年 | 261篇 |
2003年 | 231篇 |
2002年 | 172篇 |
2001年 | 125篇 |
2000年 | 139篇 |
1999年 | 111篇 |
1998年 | 95篇 |
1997年 | 73篇 |
1996年 | 77篇 |
1995年 | 42篇 |
1994年 | 40篇 |
1993年 | 39篇 |
1992年 | 37篇 |
1991年 | 19篇 |
1990年 | 17篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 18篇 |
1986年 | 19篇 |
1985年 | 23篇 |
1984年 | 18篇 |
1983年 | 10篇 |
1982年 | 8篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 7篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1974年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Studies have shown that both food deprivation and response cost have important influences on the magnitude of self-administration of a wide variety of psychoactive drugs. In an attempt to extend these findings to the smoked route of drug self-administration, the effects of food allotment and fixed-ratio (FR) value were evaluated in four male rhesus monkeys trained to smoke cocaine base. In the first phase of the experiment, monkeys were trained to self-administer smoked cocaine base under a chained progressive-ratio (PR), fixed-ratio (FR) schedule during daily experimental sessions. Monkeys were required to make 20 lever-press responses and then five inhalations on a smoking spout to obtain the first smoke delivery. The lever ratio then increased to 60, 140, 300, 620, 1260, 2540, and 4940 for each successive smoke delivery. The initial lever ratio value was reset to 20 at the beginning of each daily session. The body weights of three monkeys were determined under free-feeding conditions. Monkeys were then restricted to 100 g food and, when body weights had stabilized, the daily food allotment was increased to 150 g, approximately 210 g, or greater than 400 g (satiation). As the daily food allotment and body weight increased, the mean number of smoke deliveries decreased in two of three monkeys. In the second phase of the experiment, three monkeys were maintained under either food-satiated or food-restricted conditions. Body weights were maintained at approximately 90% of their free-feeding weights under food-restricted conditions. The cost of the drug (lever FR value) was constant within each experimental session, but was increased after 3 consecutive days of stable responding. Fixed-ratio values were increased from 128 to 256, 512, 1024, and 2048. Monkeys were required to complete the lever FR value and then to make five inhalations on the smoking spout to gain access to 1.0 mg/kg per delivery cocaine base. The mean number of smoke deliveries increased at FR 256, 512, and 1024 when monkeys were food-restricted as opposed to food-satiated. Correspondingly, the mean number of responses increased under food-restricted conditions. Responding continued to increase over a wider range of FR values, and the peak number of responses was higher under food-restricted, as opposed to food-satiated conditions. These results, using the smoking route of administration, are consistent with the hypothesis that food deprivation increases the self-administration of reinforcing drugs. 相似文献
22.
大型颅咽管瘤的显微手术治疗 总被引:1,自引:0,他引:1
目的:结合颅底手术入路提高鞍上、三脑室、脚间池大型颅咽管瘤的手术全切除率,提高疗效。方法:采用不同颅底手术入路显微手术切除37例鞍上、三脑室、脚间池大型颅咽管瘤。结果:肿瘤全切除35例,次全切除2例。术中解剖保留垂体柄31例,所有患者术后伴有不同程度一过性尿崩、动眼神经麻痹10例。全部病例平均随访3年,复发1例。结论:对位于鞍上、三脑室和脚间池的大型颅咽管瘤应根据肿瘤的不同生长方向采用相应的手术入路,充分暴露鞍区各脑池、视神经、前循环及其穿通支和三脑室底部等结构,对脑组织和脑神经牵拉小,术后并发症少且易控制,可取得较好的手术治疗效果。 相似文献
23.
The effectiveness of educational activities on changing the handwashing habits of preschool children was evaluated using parental surveys and direct observations. Baseline handwashing behaviors were observed and recorded, and parents completed a pre-intervention survey. After interventions were administered, post-intervention data was collected on preschoolers' handwashing habits. Children participated in one, three or five handwashing intervention activities. Results of this study indicate that the educational activities implemented resulted in increased knowledge of the importance of proper handwashing and in positive changes in the children's handwashing habits, particularly for the children who participated in all five interventions. 相似文献
24.
P. J. Donald 《European archives of oto-rhino-laryngology》2007,264(7):713-717
The purpose of this paper is to detail the contraindications for surgery, with curative intent for those patients who suffer
from a head and neck malignancy that invades the intracranial space. This is based on a 30-year experience of over 250 patients.
The most important contraindications are anatomical. Surgery is not done if the following structures are invaded: brain stem,
eloquent portions of the cerebrum, superior sagittal sinus, both internal carotid arteries, both cavernous sinuses and certain
vital bridging veins. Certain tumor factors are absolute but are occasionally relative contraindications: such as distant
metastatic disease especially if multiple and at multiple anatomic sites. Some tumors that behave in a particularly virulent
fashion that defy complete resection but are often difficult to predict preoperatively. Lack of patient medical fitness or
absence of patient commitment to the operative procedure is make-up two serious contraindications to surgery.
Presented at the 77th Annual Meeting of the German Society for Oto-Rhino-Laryngology, Head and Neck Surgery, 24–28 May 2006,
Mannheim, Germany. 相似文献
25.
对我省医学临床教学基地评审结果进行分析,就大部分基地教学意识不强、教学设施不完善、教学条件有待改善、师资队伍素质水平不高等问题进行了阐述,并针对存在的问题提出建议和思考,从建章立制规范管理、加强建设、提供保障、重视培训、提高素质、强化管理、创新机制等方面进行探索,希望能使我省医学临床教学基地质量得以提高、完善,为我省培养一流的医学专业人才奠定基础. 相似文献
26.
Background : Osseous cranial base tumours in children present as a diverse collection of both benign and malignant pathologies. Concerns raised by the difficulty in accurate diagnosis and local recurrence of benign lesions and by the long-term sequelae of radiotherapy for malignant cranial tumours (marked local growth disturbances, pituitary dysfunction, visual disturbances, late new tumour induction) prompted an evaluation of surgical resection of cranial base tumours in children, with specific regard to safety, efficacy and aesthetic result. Methods : A retrospective review was performed of 10 consecutive children presenting with tumours either arising from or eroding into bone of the cranial base who were managed by surgical resection in a 10-year period from 1986 to 1996. The patients demonstrated a great variation in both presentation and pathology. All underwent surgical resection of tumour with reconstruction where indicated. Results : There were no postoperative complications or mortality. All patients remained clinically free of disease at follow-up, which ranged from 17 months to 9 years (mean 6 years and 4 months). Conclusion : The aggressive surgical resection and craniofacial reconstruction of cranial base tumours in the paediatric population offers a safe and efficacious mode of treatment that obviates problems of diagnosis and local recurrence for benign lesions and of the long-term sequelae of radiotherapy for malignant lesions. 相似文献
27.
师范大学学生艾滋病知识现况调查及健康教育近期效果评价 总被引:4,自引:0,他引:4
目的 了解师范大学学生艾滋病相关知识及行为现状,为高校制定艾滋病健康教育规划提供参考。方法 抽取天津师范大学2000年入学新生,通过集体讲座,使用统一的调查问卷在教育前后分别调查学生艾滋病相关知识及态度,并利用EPIinf0软件进行分析。结果 天津师范大学一年级学生健康教育后对艾滋病性质、主要传播途径等的正确回答率都有所提高,能够正确对待艾滋病病毒感染者,教育前后学生对性行为的态度无明显改变。学生希望获得艾滋病知识的前4位方式均为电视、报刊书籍、卫生课和医生。结论 从国情和现实需要出发,在大学生中开展适时、适度、适量的性健康教育和健康行为教育,对预防性病艾滋病有着积极的意义。 相似文献
28.
目的了解城郊结合部外来人员聚集地生活环境现况和霍乱等肠道传染病健康知信行情况,进一步明确肠道传染病防治健康教育与健康促进工作的重点开展方向。方法采用随机抽样的方法,运用统一设计的调查问卷对嘉兴市5县2区城郊结合部等外来人员聚集地进行流行病学调查。结果93.06%的调查对象以租房为主,90.61%的生活用水来源于自来水,9.25%用井水;78.61%的人知道霍乱传播途径,21.53%的人知道霍乱主要临床症状,28.03%的人知道肠道传染病全部预防措施;77.31%的知识来源于电视,其他顺位依次为书刊、广播、家人或朋友处;希望获得宣传资料形式:传单占46.68%,墙报占31.21%。结论外来人员租房人数居多,有部分人使用井水;肠道传染病相关知识了解的较少。应采取多部门齐抓共管来改善外来人员聚集地的生活环境,因地制宜地对外来人员开展有针对性的预防肠道传染病健康教育。 相似文献
29.
[目的]探讨切除侵犯中颅窝的咽旁颞下区巨大肿瘤安全而彻底的手术进路.利用颞部切口可充分暴露中颅窝底和颞下窝以及颌下进路显露咽旁区解剖的特点,联合进路切除2例咽旁颞下区巨大肿瘤.2例侵犯中颅窝底的咽旁颞下区肿瘤顺利切除,患者术中组织损伤、出血量相对较少,术后无严重并发症.[结论]颞部-颌下联合进路适合于侵犯中颅窝底的咽旁颞下区肿瘤的手术切除. 相似文献
30.