全文获取类型
收费全文 | 98508篇 |
免费 | 9062篇 |
国内免费 | 2899篇 |
专业分类
耳鼻咽喉 | 547篇 |
儿科学 | 1479篇 |
妇产科学 | 991篇 |
基础医学 | 7901篇 |
口腔科学 | 2726篇 |
临床医学 | 9387篇 |
内科学 | 9299篇 |
皮肤病学 | 1123篇 |
神经病学 | 5579篇 |
特种医学 | 2720篇 |
外国民族医学 | 4篇 |
外科学 | 7152篇 |
综合类 | 15233篇 |
现状与发展 | 10篇 |
一般理论 | 2篇 |
预防医学 | 13068篇 |
眼科学 | 1052篇 |
药学 | 16473篇 |
203篇 | |
中国医学 | 11183篇 |
肿瘤学 | 4337篇 |
出版年
2024年 | 347篇 |
2023年 | 1699篇 |
2022年 | 2970篇 |
2021年 | 4066篇 |
2020年 | 3736篇 |
2019年 | 3102篇 |
2018年 | 3078篇 |
2017年 | 3315篇 |
2016年 | 3299篇 |
2015年 | 3104篇 |
2014年 | 6748篇 |
2013年 | 6921篇 |
2012年 | 6224篇 |
2011年 | 6735篇 |
2010年 | 5164篇 |
2009年 | 4646篇 |
2008年 | 4939篇 |
2007年 | 5338篇 |
2006年 | 4383篇 |
2005年 | 3835篇 |
2004年 | 3280篇 |
2003年 | 2850篇 |
2002年 | 2289篇 |
2001年 | 2047篇 |
2000年 | 1801篇 |
1999年 | 1553篇 |
1998年 | 1242篇 |
1997年 | 1225篇 |
1996年 | 1046篇 |
1995年 | 1059篇 |
1994年 | 955篇 |
1993年 | 832篇 |
1992年 | 748篇 |
1991年 | 676篇 |
1990年 | 634篇 |
1989年 | 536篇 |
1988年 | 529篇 |
1987年 | 423篇 |
1986年 | 395篇 |
1985年 | 467篇 |
1984年 | 363篇 |
1983年 | 261篇 |
1982年 | 316篇 |
1981年 | 254篇 |
1980年 | 225篇 |
1979年 | 174篇 |
1978年 | 142篇 |
1977年 | 129篇 |
1976年 | 107篇 |
1975年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
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
2.
《Orthopaedics and Trauma》2022,36(6):304-310
Congenital vertical talus (CVT) is a rare foot deformity that presents with a rigid flat foot at birth. CVT can present as an isolated abnormality in the newborn, however in at least 50% of cases in association with other conditions. Full neuro-axial imaging is essential to detect any associated neurologic problems. Radiographs of the foot, including forced plantar and dorsiflexion laterals, are diagnostic. Gold standard modern treatment uses the Dobbs method of serial manipulation and casting with minimally-invasive stabilization of the talonavicular joint and Achilles tendon tenotomy. 相似文献
3.
4.
Virginija Pokut Rta Kazlauskait Irmina Matonyt 《Health & social care in the community》2022,30(1):193-202
Demographic situation, changes in the role of women in society and growing demand for long-term care (LTC) of older people have challenged the ability to meet the growing LTC needs in most developed countries. In countries where responsibility for LTC is still largely laid on families, it is, however, even more critical and calls for improvements in formal LTC systems. More intensive stakeholder collaboration in LTC policy development, organising and delivery are of primary importance in improving LTC systems. Such collaboration, however, is not always successful; thus, it is critical to understand what makes it effective and efficient. In this paper, we specifically look into multistakeholder collaboration in LTC in Lithuania, one of the fastest ageing countries in the EU, with the demand for LTC services growing fast and exceeding the supply despite rising business and NGO engagement. To determine facilitators of such collaboration, we build on the data obtained through eight focus group discussions with all key stakeholder representatives (LTC policymakers, organisers and service providers [public, private and NGOs], 54 participants in total). Our findings indicate that in addition to national and organisational level facilitators studied in prior research, there are important individual level factors, such as meaningfulness at work, concern and care for others, possibility for personal growth and development, satisfaction with supervision, a sense of belonging and role clarity. On the other hand, our results show that collaboration is constrained by a shortage of human resources, increased workload caused by growing LTC demand, bureaucratic requirements, legal restrictions, lack of awareness of LTC service availability among elder persons, and prevailing social norms and attitudes to institutionalised care. Interestingly, a lack of financial resources is not perceived as a major constraint. 相似文献
5.
6.
This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.
The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same. 相似文献
7.
8.
����ǿ�������Σ����������������� ٻ 《中国实用口腔科杂志》2015,8(5):297-301
??Objective To observe the effects of lithium chloride pretreatment on cognitive ability of aged rats after oral and maxillofacial surgery. Methods A total of 48 aged male SD rats??18 ~ 20 months old??weight 550 ~ 700 g?? were bought from the Experimental Animal Center of China Medical University . These rats were randomly divided into three groups??including the normal control group??group C??n=16????surgery and anesthesia group??group O??n=16????and lithium chloride preconditioning group??group L??n=16??.Rats in each group were randomly divided into two parts??one part was given Morris water maze test three days after the surgery and its characteristics of behavior tested. Another part was decapitated 24 h after the surgery and extracted and the hippocampus brain separated at the same time. Test expression content of IL-1β GSK-3β p-GSK-3β??ser9??in the hippocampus by Elisa and Western blotting detection method respectively. Results Morris water maze test showed that??the first day after surgery??latencies of group L and O were significantly longer than group C??compared with group C in swimming distance?? latency and swim distances of group L were shorter than group O. With the comparison of multiple analysis of variance??differences were statistically significant??P??0.05??. Groups L and O in the second day were slightly shortened compared to the first day??on the third day after surgery it has also improved over the second day. Space exploration experiments in rats showed that??the dwell time of group C was significantly longer in the platform quadrant and the frequency of crossing the platform also increased compared with groups L and O. In addition??group L and group O were higher in IL-β levels than group C??the difference being statistically significant by analysis of variance??P??0.05????but group L was significantly lower compared with group O??the difference being statistically significant??P??0.05??. The content of GSK-3β of three groups were of no significant difference??P > 0.05????but p-GSK-3β??ser9??content was significantly lower in group L and O than in group C. The content of GSK-3β of group L was higher than in group O??the difference being statistically significant??P??0.05??. Conclusion Pretreatment with lithium chloride in postoperative aged rats can inhibit the expression of inflammatory cytokines and increase GSK-3β phosphorylation in the hippocampus cells??so p-GSK-3β??ser9??upregulates and inhibites the apoptosis of brain cells??thereby improved cognitive abilities after the cavity and maxillofacial surgery. 相似文献
9.
10.