全文获取类型
收费全文 | 3332篇 |
免费 | 277篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 56篇 |
妇产科学 | 35篇 |
基础医学 | 616篇 |
口腔科学 | 84篇 |
临床医学 | 214篇 |
内科学 | 486篇 |
皮肤病学 | 31篇 |
神经病学 | 286篇 |
特种医学 | 97篇 |
外科学 | 157篇 |
综合类 | 285篇 |
一般理论 | 2篇 |
预防医学 | 457篇 |
眼科学 | 18篇 |
药学 | 510篇 |
1篇 | |
中国医学 | 253篇 |
肿瘤学 | 53篇 |
出版年
2023年 | 43篇 |
2022年 | 56篇 |
2021年 | 100篇 |
2020年 | 90篇 |
2019年 | 109篇 |
2018年 | 112篇 |
2017年 | 118篇 |
2016年 | 104篇 |
2015年 | 95篇 |
2014年 | 173篇 |
2013年 | 299篇 |
2012年 | 161篇 |
2011年 | 149篇 |
2010年 | 116篇 |
2009年 | 165篇 |
2008年 | 133篇 |
2007年 | 128篇 |
2006年 | 125篇 |
2005年 | 103篇 |
2004年 | 93篇 |
2003年 | 108篇 |
2002年 | 89篇 |
2001年 | 66篇 |
2000年 | 64篇 |
1999年 | 44篇 |
1998年 | 53篇 |
1997年 | 54篇 |
1996年 | 58篇 |
1995年 | 72篇 |
1994年 | 65篇 |
1993年 | 55篇 |
1992年 | 52篇 |
1991年 | 58篇 |
1990年 | 36篇 |
1989年 | 31篇 |
1988年 | 36篇 |
1987年 | 32篇 |
1986年 | 28篇 |
1985年 | 33篇 |
1984年 | 26篇 |
1983年 | 20篇 |
1982年 | 30篇 |
1981年 | 16篇 |
1980年 | 20篇 |
1979年 | 19篇 |
1978年 | 12篇 |
1977年 | 4篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1973年 | 4篇 |
排序方式: 共有3687条查询结果,搜索用时 31 毫秒
1.
2.
The research and development of penicillin started with difficulty before 1949 and achieved certain results. In 1951, after the founding of the People's Republic of China, Zhang Weishen, as the only Chinese scientist who had been trained and worked in a penicillin research and development center in the United States for many years, overcame many difficulties and returned to China. In 1953, with the efforts of Zhang Weishen and his colleagues, China realized the industrialized production of penicillin, alleviating the urgent needs of the masses. Antibiotics has also become the first discipline to achieve major scientific and technological achievements after the founding of the New China. In the mid-1950s, the technical breakthrough in the localization of lactose substitutes marked the localization of the raw materials of the penicillin-producing culture medium, which paved the way for the industrialized production of penicillin with Chinese characteristics. Antibiotics have become one of the most widely used and affordable drugs for hundreds of millions of patients in China, and China has since ended the humiliating history of the “Sick Man of East Asia". 相似文献
3.
In forensic medicine, although various alcohols have been reported as indicators of decomposition in collected blood, no studies have examined short-chain fatty acids as indicators. In this study, the blood n-butyric acid concentration was quantified, and the association between n-butyric acid and decomposition was investigated to determine whether the detection of n-butyric acid could be a new indicator of decomposition. Among the forensic autopsies performed from 2016 to 2018 in our laboratory, the cases were divided into decomposed (n = 20) and non-decomposed (n = 20) groups based on macroscopic findings. Blood samples collected at the time of autopsy were derivatized with 3-nitrophenylhydrazine hydrochloride after solid-phase extraction. The n-butyric acid concentration was measured using liquid chromatography–tandem mass spectrometry. In addition, ethanol and n-propanol were measured using a gas chromatography-flame ionization detector. There was a significant difference (p < 0.01) in the concentrations of n-butyric acid between the decomposed and non-decomposed groups (0.343 ± 0.259 [0.030–0.973] and 0.003 ± 0.002 [0.001–0.007] mg/mL, respectively). In the decomposed group, n-butyric acid was detected at high concentrations, even in cases where n-propanol was low. These results suggest that n-butyric acid is more likely to be an indicator of blood decomposition than n-propanol. 相似文献
4.
5.
《Vaccine》2019,37(47):6987-6995
Vero cells are nowadays widely used in the production of human vaccines. They are considered as one of the most productive and flexible continuous cell lines available for vaccine manufacturing. However, these cells are anchorage dependent, which greatly complicates upstream processing and process scale-up. Moreover, there is a recognized need to reduce the costs of vaccine manufacturing to develop vaccines that are affordable worldwide. The use of cell lines adapted to suspension growth contributes to reach this objective.The current work describes the adaptation of Vero cells to suspension culture in different serum free media according to multiple protocols based on subsequent passages. The best one that relies on cell adaption to IPT-AFM an in-house developed animal component free medium was then chosen for further studies. Besides, as aggregates have been observed, the improvement of IPT-AFM composition and mechanical dissociation were also investigated.In addition to IPT-AFM, three chemically defined media (CD293, Hycell CHO and CD-U5) and two serum free media (293SFMII and SFM4CHO) were tested to set up a serum free culture of the suspension-adapted Vero cells (VeroS) in shake flasks. Cell density levels higher than 2 × 106 cells/mL were obtained in the assessed conditions. The results were comparable to those obtained in spinner culture of adherent Vero cells grown on Cytodex 1 microcarriers.Cell infection with LP-2061 rabies virus strain at an MOI (Multiplicity of Infection) of 0.1 and a cell density of 8 ± 0.5 × 105 cells/mL resulted in a virus titer higher than 107 FFU/mL in all media tested. Nevertheless, the highest titer equal to 5.2 ± 0.5 × 107 FFU/mL, was achieved in IPT-AFM containing a reduced amount of Ca++ and Mg++. Our results demonstrate the suitability of the obtained VeroS cells to produce rabies virus at a high titer, and pave the way to develop VeroS cells bioreactor process for rabies vaccine production. 相似文献
6.
《Vaccine》2019,37(47):7003-7010
Control and prevention of rapid influenza spread among humans depend on the availability of efficient and safe seasonal and pandemic vaccines, made primarily from inactivated influenza virus particles. Current influenza virus production processes rely heavily on embryonated chicken eggs or on cell culture as substrate for virus propagation. Today’s efforts towards process intensification in animal cell culture could innovate viral vaccine manufacturing using high-yield suspension cells in high cell density perfusion processes. In this work, we present a MDCK cell line adapted to grow as single cell suspension with a doubling time of less than 20 h, achieving cell concentrations over 1 × 107 cells/mL in batch mode. Influenza A virus titer obtained in batch infections were 3.6 log10(HAU/100 µL) for total- and 109 virions/mL for infectious virus particles (TCID50), respectively. In semi-perfusion mode concentrations up to 6 × 107 cells/mL, accumulated virus titer of 4.5 log10(HAU/100 µL) and infectious titer of almost 1010 virions/mL (TCID50) were possible. This exceeds results reported previously for cell culture-based influenza virus propagation by far and suggests perfusion cultures as the preferred method in viral vaccine manufacturing. 相似文献
7.
8.
9.
《Actas dermo-sifiliográficas》2022,113(6):543-549
BackgroundCutaneous manifestations are complicated to treat in rare diseases. The main aim of this study was to analyze the impact of compounded drugs prepared by hospital pharmacists on the quality of life of patients with genodermatoses.Material and methodsWe undertook a cross-sectional study of patients with genodermatoses treated with topical medications compounded and dispensed by the pharmacy at Complejo Hospitalario Universitario in Pontevedra, Spain. We collected demographic data and answers to questionnaires examining generic and disease-specific quality of life, treatment satisfaction, and treatment adherence.ResultsNine patients were included. We observed a significant improvement in health-related quality of life following treatment with compounded drugs. Satisfaction with the topical medications was 2.8 on a scale of 0 (greatest satisfaction) to 25. Treatment adherence was 59%.ConclusionsDrug compounding facilitates access to orphan drugs that are not available for many rare diseases. Few studies, however, have analyzed impact on quality of life in this setting. In this series of patients with genodermatoses, topical medications compounded and dispensed by a hospital pharmacy improved health-related quality of life. This preliminary study has given rise to a multicenter study of compounding for ichthyosis. We expect that analysis of a larger sample will confirm our findings. 相似文献
10.
目的研究羌活Notopterygium incisum的香豆素类成分及其抗炎活性。方法采用硅胶、HPLC等柱色谱方法进行分离纯化,通过质谱、核磁共振波谱数据鉴定化合物的结构;采用脂多糖(LPS)诱导的小鼠巨噬细胞RAW 264.7炎症反应模型,考察羌活中香豆素类成分对炎症反应模型一氧化氮(NO)生成的影响。结果从羌活甲醇提取物分离得到24个香豆素类化合物,分别鉴定为异欧前胡素(1)、川白芷素(2)、补骨脂素(3)、香柑内酯(4)、茵陈素(5)、欧芹酚(6)、5-去氢羌活醇(7)、环氧脱水羌活醇(8)、7″-O-甲基异羌活醇(9)、佛手柑素(10)、7-异戊烯氧基-6-甲氧基-香豆素(11)、栓翅芹烯醇(12)、羌活醇(13)、去甲呋喃羽叶芸香素(14)、异羌活醇(15)、蛇床夫内酯(16)、6-异戊烯氧基伞形花内酯(17)、紫花前胡苷元(18)、异虎耳草素(19)、紫花前胡苷(20)、前胡苷V(21)、前胡苷I(22)、印枳苷元-11-O-β-D-吡喃葡萄糖基-(1→6)-β-D-吡喃葡萄糖苷(23)、羌活苷(24)。化合物7~10、13和15抑制LPS诱导的RAW 264.7细胞NO生成活性最强,最大半数抑制浓度(IC_(50))值为8.50~35.12μmol/L。结论化合物7为新的天然产物,化合物17为首次从羌活中分离得到;C-5位上具有多烯烃结构的香豆素抑制LPS诱导的RAW 264.7细胞NO生成活性较强。 相似文献