全文获取类型
收费全文 | 39038篇 |
免费 | 1880篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 340篇 |
儿科学 | 1231篇 |
妇产科学 | 1090篇 |
基础医学 | 5327篇 |
口腔科学 | 659篇 |
临床医学 | 6134篇 |
内科学 | 7107篇 |
皮肤病学 | 713篇 |
神经病学 | 3576篇 |
特种医学 | 667篇 |
外科学 | 3448篇 |
综合类 | 409篇 |
一般理论 | 58篇 |
预防医学 | 4688篇 |
眼科学 | 560篇 |
药学 | 2185篇 |
2篇 | |
中国医学 | 69篇 |
肿瘤学 | 2750篇 |
出版年
2024年 | 153篇 |
2023年 | 218篇 |
2022年 | 423篇 |
2021年 | 825篇 |
2020年 | 512篇 |
2019年 | 839篇 |
2018年 | 964篇 |
2017年 | 662篇 |
2016年 | 677篇 |
2015年 | 887篇 |
2014年 | 1242篇 |
2013年 | 1849篇 |
2012年 | 2783篇 |
2011年 | 2918篇 |
2010年 | 1593篇 |
2009年 | 1337篇 |
2008年 | 2653篇 |
2007年 | 2672篇 |
2006年 | 2651篇 |
2005年 | 2494篇 |
2004年 | 2395篇 |
2003年 | 2277篇 |
2002年 | 2124篇 |
2001年 | 274篇 |
2000年 | 228篇 |
1999年 | 339篇 |
1998年 | 438篇 |
1997年 | 383篇 |
1996年 | 348篇 |
1995年 | 296篇 |
1994年 | 283篇 |
1993年 | 267篇 |
1992年 | 202篇 |
1991年 | 190篇 |
1990年 | 183篇 |
1989年 | 173篇 |
1988年 | 138篇 |
1987年 | 138篇 |
1986年 | 118篇 |
1985年 | 135篇 |
1984年 | 168篇 |
1983年 | 170篇 |
1982年 | 207篇 |
1981年 | 174篇 |
1980年 | 164篇 |
1979年 | 101篇 |
1978年 | 84篇 |
1977年 | 94篇 |
1976年 | 69篇 |
1974年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Cheryl Wallerstedt RNC MS Patricia Higgins RN PhD 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》1996,25(5):389-400
Society often expects mothers and fathers to share equally in the perinatal grief process because the child was a common bond between them. Unfortunately, in perinatal grief, this is not always the case. The mother and the father can experience incongruent grieving and use discordant coping mechanisms. It is important to evaluate these differences to facilitate communication between the distraught parents. Improved communication can in turn facilitate the grieving process. 相似文献
3.
The use of N-acetylcysteine has increased in the prevention of radiographic contrast induced nephrotoxicity. Many nurses need to be aware of the proper administration and action of this prophylactic agent. This article discusses the research behind the use of N-acetylcysteine and the protocol for administration to prevent radiographic contrast-induced nephrotoxicity. 相似文献
4.
5.
Patricia K P Burnell Lars Asking Lars Borgstr?m Steve C Nichols Bo Olsson David Prime Ian Shrubb 《Journal of aerosol medicine》2007,20(3):269-281
Magnetic resonance imaging (MRI) of the oropharyngeal region from 20 adult volunteers using four model inhalation devices (varying mouthpiece diameters, airflow resistances) and tidal breathing was carried out. Statistical analysis (convex hull method) selected 12 scans from 80 data sets representing the extremes of all dimensions in the population. Twelve physical mouth-throat models were made by stereolithography using the exact scan data. The aim was to produce models with varying dimensions to span the adult population, and to investigate if oropharyngeal dimensions affected throat retention for different delivery systems. In an in vitro analysis, the models were used to determine the retention effect of the oropharyngeal airspaces when drug aerosols were administered from four inhalation delivery systems: a pressurised metered dose inhaler (pMDI), two different dry powder inhalers (DPIs A and B), and a nebulizer. The aims of this work were to determine the key parameters governing mouth-throat retention and whether retention was dependent on the delivery system used. Characterizing the throat models by measuring 51 different dimensional variables enabled determination of the most influential variables for dose retention for each inhalation delivery system. Throat model retention was found to be dependent on the delivery system (pMDI approximately DPI(A) > DPI(B) > Neb.). The most influential variable was the total throat model volume. Throat models representing high, median, and low oropharyngeal filtration in healthy adults have been identified. 相似文献
6.
Facial muscle spasms, which are rare in adults, present a particularly difficult entity for the optometrist to recognise. The condition may not even manifest itself at an eye examination and the optometrist may have to rely on subjective symptoms to assist in the recognition of the condition. It is important to diagnose the condition correctly as specific and effective treatment is available. 相似文献
7.
Dr. Barry Pass John E. Aldrich Patricia L. Scallion 《Calcified tissue international》1990,46(3):166-168
Summary The ESR spectra produced in irradiated dentin have been studied over a range of incident radiation energies from 50 kVp to
25 MVp. The behavior of the dentin ESR signal strength is similar to that of enamel as a function of the energy of the incident
radiation. The magnitude of the dentin ESR signals are, however, up to 10 times smaller than the signals of dental enamel
for a given radiation energy. The possible contributions of radiation interaction coefficients, chemical structure, and crystallite
size to the differences in ESR spectra are discussed. 相似文献
8.
M. Villaplana A. García Ayala M. P. García Hernández B. Agulleiro 《Anatomy and embryology》1996,193(5):441-452
The cell organization of the pituitary gland and the relationship between neurohypophysis and adenohypophysis in the early developmental stages of the gilthead sea bream, Sparus aurata, were studied by electron microscopy. In newly hatched larvae, the pituitary gland was embedded in the ventral floor of the diencephalon and separated from the hypothalamus by a continuous basal lamina. Elongated mesenchymal cells next to the ventral surface were observed. At this stage, there was no neurohypophysis and the adenohypophysis consisted of undifferentiated endocrine cells with small scarce secretory granules and a few stellate cells, with no distinctive zonation. An incipient neurohypophysis was present in 1-day-old larvae. The first evagination of the neurohypophysis into the adenohypophysis were observed in 2-day-old larvae and developed progressively with age, being deeper in the caudal zone. Two regions in the adenohypophysis, one anterior — the presumptive pars distalis — and one posterior — the presumptive pars intermedia — were found in 2-day-old larvae. Three regions (rostral and proximal pars distalis and pars intermedia) were clearly distinguishable in 4-day-old larvae. The ultrastructural features of the pituitary endocrine cells varied during gland differentiation, with the secretory granules gradually increasing in number and size, accompanying organelle development. Nevertheless, even in the oldest larvae studied (65 days), undifferentiated cells similar to those in the earliest stages were observed. The first blood vessels appeared in the neurohypophysis around 16 days after hatching. During early development, the pituitary gland progressively emerged from the ventral floor of the brain. By 16 days, the principal pattern of the pituitary gland architecture appeared to be established. 相似文献
9.
A common misconception is held among many ethnic minoritiesin San Francisco that AIDS is exclusively a gay whitemale disease. This myth is false, but dangerous. To assistethnic minorities in understanding their risks for AIDS, successfuleducational programs for these populations must recognize thediversity within these communities, including their differingcultures, languages and religious backgrounds. San Franciscohas adopted a model that utilizes well-established and well-respectedcommunity-based organizations to provide the education and riskreduction programs. Utilizing these organizations allows foreducation of diverse populations that is culturally and linguisticallyrelevant, thus allowing San Francisco an opportunity to preventthe national minority AIDS statistics from occurring withinits boundaries. 相似文献
10.