全文获取类型
收费全文 | 35194篇 |
免费 | 3749篇 |
国内免费 | 2315篇 |
专业分类
耳鼻咽喉 | 384篇 |
儿科学 | 419篇 |
妇产科学 | 293篇 |
基础医学 | 4288篇 |
口腔科学 | 468篇 |
临床医学 | 3990篇 |
内科学 | 5698篇 |
皮肤病学 | 808篇 |
神经病学 | 2085篇 |
特种医学 | 1761篇 |
外国民族医学 | 7篇 |
外科学 | 3505篇 |
综合类 | 5161篇 |
现状与发展 | 4篇 |
一般理论 | 3篇 |
预防医学 | 2241篇 |
眼科学 | 927篇 |
药学 | 3949篇 |
18篇 | |
中国医学 | 2400篇 |
肿瘤学 | 2849篇 |
出版年
2024年 | 198篇 |
2023年 | 662篇 |
2022年 | 1489篇 |
2021年 | 1852篇 |
2020年 | 1244篇 |
2019年 | 1284篇 |
2018年 | 1340篇 |
2017年 | 1224篇 |
2016年 | 1364篇 |
2015年 | 1868篇 |
2014年 | 2146篇 |
2013年 | 2114篇 |
2012年 | 2881篇 |
2011年 | 2943篇 |
2010年 | 1975篇 |
2009年 | 1539篇 |
2008年 | 1776篇 |
2007年 | 1751篇 |
2006年 | 1615篇 |
2005年 | 1548篇 |
2004年 | 1151篇 |
2003年 | 1256篇 |
2002年 | 1082篇 |
2001年 | 881篇 |
2000年 | 692篇 |
1999年 | 566篇 |
1998年 | 371篇 |
1997年 | 362篇 |
1996年 | 284篇 |
1995年 | 232篇 |
1994年 | 217篇 |
1993年 | 147篇 |
1992年 | 141篇 |
1991年 | 155篇 |
1990年 | 136篇 |
1989年 | 127篇 |
1988年 | 106篇 |
1987年 | 92篇 |
1986年 | 84篇 |
1985年 | 62篇 |
1984年 | 35篇 |
1983年 | 13篇 |
1982年 | 23篇 |
1981年 | 29篇 |
1980年 | 26篇 |
1979年 | 24篇 |
1978年 | 14篇 |
1976年 | 13篇 |
1975年 | 12篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Petr Heneberg Jiljí Sitko Jiří Bizos Lucie Kocková Milena Malá Ivan Literák 《Parasitology research》2014,113(9):3211-3220
Collyriclum faba (Plagiochiida: Collyriclidae) adults occur in pairs within subcutaneous cysts. Here, we tested the extensive C. faba infrapopulation for five DNA loci known to display variability among Central European C. faba individuals. The infrapopulation tested shared 100 % similarity in four of the five mitochondrial and nuclear DNA loci tested. Contrariwise, the internal transcribed spacer 1 (ITS1) loci in all but one individual differed from each other. We found only 0.0–1.5 base substitutions per 1,000 sites within the cysts, while we found 0.7–9.0 substitutions between the cysts of the single host and 3.0–9.0 substitutions when comparing C. faba individuals isolated from different host individuals. We observed the most of the ITS1 variability within 48 bp repetitive sequences featured by the chi-like sequence 5′-GCTTGTCTGCC-3′ at their beginning. Similarly to the extensive C. faba infrapopulation examined, we determined the presence of highly variable number of repetitive sequences within the ITS1 locus of C. faba isolated from multiple host species and from various geographic locations. While similar variability was observed earlier in mutually unrelated specimens of several Schistosomatidae and Microphallidae species, here, we for the first time document it among multiple individuals of a single infracommunity possessing single mitochondrial haplotype. Lower ITS1 evolutionary divergence rates observed between individuals within the cysts when compared to those between the cysts suggest that the recombination occurs at multiple stages of the life cycle. We propose DNA recombination involving chi-like sequences to serve as a general feature shared by multiple families of digenetic trematodes to increase genetic diversity of their polyembryonic populations infecting their definitive hosts. 相似文献
992.
Ho‐Kyoung Yoon Seung‐Gul Kang Heon‐Jeong Lee Young Yoo Ji Tae Choung Won Hee Seo Leen Kim 《Journal of sleep research》2014,23(2):189-195
It has been reported that sleep problems and neurocognitive deficit in asthmatic children is prevalent. However, systematic studies on these problems in stable asthma using polysomnography have rarely been performed. We therefore investigated sleep and neurocognitive functioning in children with well‐controlled asthma. Forty‐three children with well‐controlled, stable asthma and 31 controls (age range: 6–9 years) were enrolled in the study. Subjects were questioned for daytime sleepiness using the Paediatric Daytime Sleepiness Scale. Complete overnight polysomnography and neurocognitive function tests were performed on all subjects. Children with stable asthma had lower pulmonary function in comparison to their age‐matched controls. Asthmatic children had a higher apnea–hypopnea index (P < 0.001) and apnea–hypopnea‐related arousal index (P < 0.001) as compared with non‐asthmatics. Deep sleep was decreased in asthmatics (P = 0.001). In the vigilance test, the mean number of correct answers was lower (P = 0.005) and the mean reaction time was slower (P = 0.002) in asthmatic children. A hierarchical multiple linear regression showed that deep sleep and apnea–hypopnea‐related arousal index were significant predictors of vigilance. The data suggest that the prevalence of paediatric sleep‐disordered breathing and sleep fragmentation could be very high among children with well‐controlled asthma. Moreover, vigilance, the ability to maintain attention and alertness, was worse in stable asthmatic children when compared with healthy controls. Sleep‐disordered breathing should be checked even in stable asthmatic children as they are at risk for developing neurobehavioural deterioration associated with frequent arousals during sleep. Furthermore, early treatment for asthma may be required in order to prevent airway remodelling that could cause sleep problems. 相似文献
993.
D.W. Shin J. Cho D.L. Roter S.Y. Kim Ji.H. Park B. Cho H.‐S. Eom J.‐S. Chung H.‐K. Yang Jo.‐H. Park 《Clinical genetics》2014,86(2):112-120
Decisions for cancer susceptibility genetic testing (CSGT) uptake and dissemination of results occur within the family context. A national survey was performed with 990 patient–family member dyads (participation rate:76.2%), with paired questionnaires examining attitudes toward CSGT uptake and disclosure of results in response to a hypothetical scenario in which a reliable CSGT was available for the specific cancer a patient was being treated. While most patients and family members responded they would uptake or recommend CSGT if available, concordance between the dyads was poor for both patient's testing (agreement rate 77.5%, weighted κ = 0.09) and first‐degree relatives' testing(agreement rate 78.0%, weighted κ = 0.09). Most patients (93.2%) and family members (92.9%) indicated that patients should disclose positive CSGT results to family members, with dyadic agreement of 89.1% (κ = 0.15). However, there were substantial disagreement regarding when disclosure should take place, who should make the disclosure (the patient or the health care professionals), and to whom the results should be disclosed. Patients and family members may hold different attitudes toward CSGT uptake of and disclosure of results within the family. Our findings reinforce the need for a family system approach to incorporate perspectives of patients as well as their family members. 相似文献
994.
Seon‐Yeong Lee Yang‐Mi Her Mi‐Kyung Park Seung‐Ki Kwok Ji Hyeon Ju Kyung‐Su Park Ho‐Youn Kim Mi‐La Cho Sung‐Hwan Park 《Immunology》2014,142(4):573-580
Systemic lupus erythematosus (SLE) is an autoimmune disease in which abnormal immune responses are mediated by tissue‐binding autoantibodies and immune complex deposition. Because most SLE patients are women of child‐bearing age, oestrogen has been suggested to play an important role in SLE pathogenesis. One proposed role is to induce B‐cell activation, culminating in increased autoantibody production. Interleukin‐21 (IL‐21) has been shown to be crucial in the differentiation of activated B cells into plasma cells. We therefore hypothesized that oestrogen up‐regulates IL‐21 production and induces subsequent B‐cell activation in SLE patients. Peripheral blood was obtained from 22 SLE patients and 16 healthy controls. Expression levels of IL‐21 and its receptor in serum, peripheral blood mononuclear cells, and CD4+ T cells were higher in SLE patients than in healthy controls. Exposure of CD4+ T cells from SLE patients to 17β‐oestradiol led to a dose‐ and time‐dependent increase in IL‐21 expression, which was abolished in the presence of mitogen‐activated protein kinase (MAPK) (MAPK kinase, p38, Jun N‐terminal kinase) inhibitors. B cells from healthy controls showed increased antibody production when they were co‐cultured with oestrogen‐treated CD4+ T cells from SLE patients. Treatment with IL‐21 antibody abrogated the increased antibody production of the co‐culture systems. This study revealed the association between oestrogen and IL‐21 in SLE patients. Oestrogen up‐regulates IL‐21 expression of CD4+ T cells via MAPK‐dependent pathways in SLE patients, which in turn induces increased antibody production by B cells. 相似文献
995.
Vaccinia‐based influenza vaccine overcomes previously induced immunodominance hierarchy for heterosubtypic protection 下载免费PDF全文
Ji‐Sun Kwon Jungsoon Yoon Yeon‐Jung Kim Kyuho Kang Sunje Woo Dea‐Im Jung Man Ki Song Eun‐Ha Kim Hyeok‐il Kwon Young Ki Choi Jihye Kim Jeewon Lee Yeup Yoon Eui‐Cheol Shin Jin‐Won Youn 《European journal of immunology》2014,44(8):2360-2369
Growing concerns about unpredictable influenza pandemics require a broadly protective vaccine against diverse influenza strains. One of the promising approaches was a T cell‐based vaccine, but the narrow breadth of T‐cell immunity due to the immunodominance hierarchy established by previous influenza infection and efficacy against only mild challenge condition are important hurdles to overcome. To model T‐cell immunodominance hierarchy in humans in an experimental setting, influenza‐primed C57BL/6 mice were chosen and boosted with a mixture of vaccinia recombinants, individually expressing consensus sequences from avian, swine, and human isolates of influenza internal proteins. As determined by IFN‐γ ELISPOT and polyfunctional cytokine secretion, the vaccinia recombinants of influenza expanded the breadth of T‐cell responses to include subdominant and even minor epitopes. Vaccine groups were successfully protected against 100 LD50 challenges with PR/8/34 and highly pathogenic avian influenza H5N1, which contained the identical dominant NP366 epitope. Interestingly, in challenge with pandemic A/Cal/04/2009 containing mutations in the dominant epitope, only the group vaccinated with rVV‐NP + PA showed improved protection. Taken together, a vaccinia‐based influenza vaccine expressing conserved internal proteins improved the breadth of influenza‐specific T‐cell immunity and provided heterosubtypic protection against immunologically close as well as distant influenza strains. 相似文献
996.
Yong Gyu Lim Jeong Su Lee Seung Min Lee Hong Ji Lee Kwang Suk Park 《Annals of biomedical engineering》2014,42(11):2218-2227
The technology for measuring ECG using capacitive electrodes and its applications are reviewed. Capacitive electrodes are built with a high-input-impedance preamplifier and a shield on their rear side. Guarding and driving ground are used to reduce noise. An analysis of the intrinsic noise shows that the thermal noise caused by the resistance in the preamplifier is the dominant factor of the intrinsic noise. A fully non-contact capacitive measurement has been developed using capacitive grounding and applied to a non-intrusive ECG measurement in daily life. Many ongoing studies are examining how to enhance the quality and ease of applying electrodes, thus extending their applications in ubiquitous healthcare from attached-on-object measurements to wearable or EEG measurements. 相似文献
997.
Han Yu Seong Ji Young Cho Byeong Sam Choi Joong Kee Min Yong Hwan Kim Sung Woo Roh Jeong Hoon Kim Sang Ryong Jeon 《Journal of Korean medical science》2014,29(4):587-592
Intracortical microstimulation (ICMS) is a technique that was developed to derive movement representation of the motor cortex. Although rats are now commonly used in motor mapping studies, the precise characteristics of rat motor map, including symmetry and consistency across animals, and the possibility of repeated stimulation have not yet been established. We performed bilateral hindlimb mapping of motor cortex in six Sprague-Dawley rats using ICMS. ICMS was applied to the left and the right cerebral hemisphere at 0.3 mm intervals vertically and horizontally from the bregma, and any movement of the hindlimbs was noted. The majority (80%±11%) of responses were not restricted to a single joint, which occurred simultaneously at two or three hindlimb joints. The size and shape of hindlimb motor cortex was variable among rats, but existed on the convex side of the cerebral hemisphere in all rats. The results did not show symmetry according to specific joints in each rats. Conclusively, the hindlimb representation in the rat motor cortex was conveniently mapped using ICMS, but the characteristics and inter-individual variability suggest that precise individual mapping is needed to clarify motor distribution in rats.
Graphical Abstract
相似文献998.
Yong Il Hwang Yong Bum Park Yeon Mok Oh Ji Hyun Lee Tae Hyung Kim Kwang Ha Yoo Hyoung Kyu Yoon Chin Kook Rhee Deog Kyeom Kim Kyeong Cheol Shin Sang Yeub Lee Ki-Suck Jung 《Journal of Korean medical science》2014,29(8):1108-1112
The purpose of this study was to compare the Korean COPD guideline to GOLD consensus report in terms of acute exacerbation. A total of 361 patients were enrolled in this study, and 16.9% of them experienced acute exacerbation during the follow-up. A total of 6.3% of patients in GOLD A, 9.5% in GOLD B, 7.7% in GOLD C and 17.0% of GOLD D experienced exacerbation during the first year of follow-up, respectively (P=0.09). There was no one who experienced exacerbation during the first year of follow-up in the Korean group ''ga''. The 12-month exacerbation rates of Korean group ''na'' and ''da'' were 4.5% and 16.0%, respectively (P<0.001). We explore the experience of exacerbation in patients with change of their risk group after applying Korean COPD guideline. A total of 16.0% of the patients who were reclassified from GOLD A to Korean group ''da'' experienced acute exacerbation,and 15.3% from GOLD B to Korean group ''da'' experienced acute exacerbation. In summary, the Korean COPD guideline is useful to differentiate the high risk from low risk for exacerbation in terms of spirometry. This indicates that application of Korean COPD guideline is appropriate to treat Korean COPD patients. 相似文献
999.
Ji Eun Lee Duck Hyun Ryu Ho Jung Jeong Jung Hoon Kim Ji Eun Jun June Soo Kim Soo Youn Lee 《Journal of Korean medical science》2014,29(9):1317-1319
A 73-yr-old Korean man with permanent atrial fibrillation visited outpatient clinic with severely increased International Normalized Ratio (INR) values after taking a usual starting dosage of warfarin to prevent thromboembolism. We found out later from his blood tests that he had hyperthyroidism at the time of treatment initiation. His genetic analysis showed CYP2C9*1/*3 and VKORC1+1173TT genotypes. We suspect that both hyperthyroidism and genetic variant would have contributed to his extremely increased INR at the beginning of warfarin therapy. From this case, we learned that pharmacogenetic and thyroid function test might be useful when deciding the starting dosage of warfarin in patients with atrial fibrillation.
Graphical Abstract
相似文献1000.
Ji Yeon Kang Sook Hee Sung Yeon Ju Lee Tae In Choi Seung Jin Choi 《Journal of Korean medical science》2014,29(10):1353-1359
Ectoenzyme nucleotide pyrophosphate phosphodiesterase 1 (ENPP1) gene has been studied in relation to type 2 diabetes mellitus (T2DM) and insulin resistance (IR). We hypothesized that the difference in genotype may be one of the factors that affect the outcome of intervention. We genotyped 448 men with fasting glucose≥5.6 mM/L, including 371 in subjects with K allele (KK) (69 control group [CG]; and 302 intervention group [IG]) and 77 in subjects with Q allele (KQ+QQ) (13 CG and 64 IG). The web-based intervention based on a lifestyle modification was delivered by e-mail once a month for 10 months. In the KK, IG demonstrated significantly decreased levels of fasting serum insulin (FSI) as compared to CG and homeostasis model of assessment of insulin resistance (HOMA-IR). In the KQ+QQ IG group, hemoglobin A1c (HbA1c), FSI and HOMA-IR were significantly decreased, and showed further reduction in the HOMA-IR than KQ+QQ CG. After analysis of covariance, K121Q did significantly influence the change of HbA1c in CG after appropriate adjustment. In a multivariate model, BMI change predicted HOMA-IR change (adjusted β=0.801; P=0.022) in KK IG subjects with T2DM. ENPP1 K121Q did not influence the change in IR. However, individuals with T2DM carrying the K121 variant are very responsive to the effect of BMI reduction on HOMA-IR.