全文获取类型
收费全文 | 58008篇 |
免费 | 3852篇 |
国内免费 | 279篇 |
专业分类
耳鼻咽喉 | 542篇 |
儿科学 | 2091篇 |
妇产科学 | 1476篇 |
基础医学 | 8481篇 |
口腔科学 | 905篇 |
临床医学 | 5474篇 |
内科学 | 13643篇 |
皮肤病学 | 1236篇 |
神经病学 | 6270篇 |
特种医学 | 1212篇 |
外科学 | 4869篇 |
综合类 | 313篇 |
现状与发展 | 1篇 |
一般理论 | 44篇 |
预防医学 | 5198篇 |
眼科学 | 892篇 |
药学 | 4379篇 |
中国医学 | 143篇 |
肿瘤学 | 4970篇 |
出版年
2024年 | 91篇 |
2023年 | 709篇 |
2022年 | 1477篇 |
2021年 | 2524篇 |
2020年 | 1431篇 |
2019年 | 1877篇 |
2018年 | 2075篇 |
2017年 | 1679篇 |
2016年 | 1842篇 |
2015年 | 1972篇 |
2014年 | 2602篇 |
2013年 | 3282篇 |
2012年 | 4784篇 |
2011年 | 4784篇 |
2010年 | 2548篇 |
2009年 | 2186篇 |
2008年 | 3637篇 |
2007年 | 3668篇 |
2006年 | 3325篇 |
2005年 | 3043篇 |
2004年 | 2803篇 |
2003年 | 2507篇 |
2002年 | 2284篇 |
2001年 | 398篇 |
2000年 | 349篇 |
1999年 | 403篇 |
1998年 | 379篇 |
1997年 | 329篇 |
1996年 | 233篇 |
1995年 | 225篇 |
1994年 | 215篇 |
1993年 | 168篇 |
1992年 | 196篇 |
1991年 | 143篇 |
1990年 | 140篇 |
1989年 | 137篇 |
1988年 | 128篇 |
1987年 | 128篇 |
1986年 | 109篇 |
1985年 | 112篇 |
1984年 | 126篇 |
1983年 | 117篇 |
1982年 | 97篇 |
1981年 | 79篇 |
1980年 | 72篇 |
1979年 | 54篇 |
1978年 | 52篇 |
1977年 | 46篇 |
1975年 | 45篇 |
1974年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Michalik J Skotarczak B Skoracki M Wodecka B Sikora B Hofman T Rymaszewska A Sawczuk M 《Journal of medical entomology》2005,42(5):850-856
Wild rodents and the subadult Ixodes ricinus (L.) ticks infesting them were examined for the presence of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner s.l. in a sylvatic habitat in west central Poland during May-September 2002. In total, 818 feeding ticks were recovered from 73 infested yellow-necked mice, Apodemus flavicollis Melchior; in addition, bank voles, Clethrionomys glareolus Schreber, were rarely captured and proved to be weakly parasitized. Only 2.7% of A. flavicollis and 2.2% of 320 engorging larvae were polymerase chain reaction (PCR) positive for the bacterium. All spirochete-PCR-positive samples yielded exclusively B. burgdorferi s.s. This genospecies was also the most prevalent in questing nymphs and accounted for 87.5% of the total number of Borrelia infections in nymphal ticks collected during May and June 2 yr later. The presence of the same genospecies both in naturally engorged larvae and blood-positive animals as well as the high predominance of B. burgdorferi s.s. in questing nymphs strongly differs from most study sites investigated in Europe. This unique pattern of Borrelia-diversity in both rodents and ticks seems to be determined by highly site-specific host vertebrate cenosis, and yellow-necked mice are involved in the maintenance of B. burgdorferi s.s. in the forest habitat. However, the transmission efficiency of this spirochete from the mice to the I. ricinus vector seems to be very low. The research provides additional information on the complexity of B. burgdorferi s.l. ecology in Europe, pointing to the importance of the local host community. 相似文献
102.
A hamster cell line obtained from a secondary transplanted SV-40-induced tumor was found to spontaneously release type C virus particles. The particles possessed all biochemical features characteristic of retroviruses and induced syncytium formation in XC cells but were not oncogenic for hamsters. Nucleic acid hybridization assays demonstrated that the isolated virus was an endogenous retrovirus of hamster, lacking sequence homology with mouse and other animal species. 相似文献
103.
Detection and typing of herpes simplex DNA in genital swabs by real-time polymerase chain reaction 总被引:4,自引:0,他引:4
The LightCycler polymerase chain reaction (PCR) is a sensitive assay for the detection of Herpes simplex virus (HSV) DNA in muco-cutaneous swabs. Software-based analysis of the probe melting temperature (Tm) can be used to discriminate between HSV types (HSV-1 and HSV-2). Among 76 HSV DNA positive genital swabs, atypical Tms were observed in 14 (18%). The 14 samples were all typed as HSV-2 by sequence alignment. In 4/14 samples, the atypical Tm was associated with sequence variation at the probe-binding site. Among 10 samples with conserved sequences, Tms were influenced by the specimen preparation method prior to PCR. These findings indicate that multiple factors including, but not limited to sequence variation complicate melting curve analysis following real-time PCR. Alternative typing methods are recommended for specimens with atypical melting curves. 相似文献
104.
Histological score for cells with irregular nuclear contours for the diagnosis of reflux esophagitis in children 总被引:5,自引:0,他引:5
Histological criteria for the diagnosis of reflux esophagitis include basal zone hyperplasia, stromal papillae elongation, and inflammatory infiltrate. However, endoscopic esophageal biopsy specimens may include little or no lamina propria. Intraepithelial T lymphocytes, seen in hematoxylin and eosin-stained sections as cells with irregular nuclear contours (CINC), may have a higher density in children with esophagitis. We evaluated the diagnostic accuracy of a numerical score built up by grading the "classical" parameters and its correlation with CINC density in grasp biopsy specimens obtained from children undergoing esophagogastroduodenoscopy with and without esophagitis. We analyzed esophageal biopsy specimens from 349 children (median age, 5 years) subdivided in 4 groups according to the previous routine histology report: group 1, 144 children with esophagitis; group 2, 65 controls; group 3, 51 children with dubious esophagitis; and group 4, 75 children with esophagitis on endoscopy but a normal histology report. A numerical value was assigned to each parameter; the sum of these values represented the histological score. We also evaluated intraepithelial CINC density (ie, number of CINC per high-power field). We separately analyzed histological sections with and without lamina propria. For both total score and for CINC density, we calculated a cutoff using a receiver operating characteristic curve. Cutoffs of 6 for score and of 4 for CINC density provided the best sensitivity and specificity. Sensitivity of the histological score was better in biopsy specimens containing lamina propria (94%) than in those without lamina propria (4%). Sensitivity of CINC density was satisfactory in both specimens with (78%) and without (75%) lamina propria. Specificity was satisfactory for both parameters. In conclusion, when lamina propria was present in sections of endoscopic esophageal biopsy specimens, histological score provided a better diagnostic accuracy for the diagnosis of esophagitis. However, when no lamina propria was present, as was the case in 67% of our children, CINC density had better sensitivity. In addition, this latter parameter showed esophageal mucosa damage in 34% of previously dubious cases or cases with esophagitis at endoscopy but a previous routine histology report of normal mucosa. 相似文献
105.
Anna Okulewicz Jerzy Okulewicz Joanna Hildebrand Grzegorz Zaleśny 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2007,52(3):292-294
Three male specimens of the eyeworm, Oxyspirura chabaudi, were found during the post mortem examination of one individual of Turdus merula L. (Passeriformes). This is the first record of Turdus merula as a host for O. chabaudi. 相似文献
106.
Malgorzata Krajewska Walasek Anna Gutkowska Beata Bieliska Bozenna Goryluk-Kozakiewicz Ewa Popowska 《Clinical genetics》1998,54(1):60-64
We report on a case of Prader-Willi syndrome (PWS) with a true reciprocal unbalanced translocation, 45,XX,-15,der(11)t(11;15)pat. The proposita was diagnosed clinically as having severe PWS. Molecular studies revealed loss of the paternal methylation pattern at locus D15S63 and a deletion encompassing the loci from at least D15S10 to D15S97 of paternal chromosome 15. FISH studies confirmed the deletion of 15q11-q13 region and the presence of two telomeres on all chromosomes. The proposita's father, the father's sister and their mother are all carriers of the same balanced translocation t(11;15)(q25;q13). By genomic imprinting we would expect that if the father's sister were to give birth to a child with the same unbalanced translocation as the proband, it would be affected by Angelman syndrome.
To date, a similar familial unbalanced translocation due to loss of the small chromosome 15 derivative has not been described. 相似文献
To date, a similar familial unbalanced translocation due to loss of the small chromosome 15 derivative has not been described. 相似文献
107.
Daniela Concolino Simona Sestito Francesca Falvo Giusy Romano Miriam Ceravolo Elisa Anastasio Licia Pensabene Elisa A. Colombo Lidia Larizza 《European journal of medical genetics》2019,62(1):73-76
Clericuzio-type poikiloderma with neutropenia is a well-defined nosological entity, but despite a remarkable number of clinical reports, no long term follow-up data has been presented to date regarding patients with this rare condition.Here we describe the results of clinical follow-up of three siblings, one male (Patient 1) and two females (Patients 2 and 3), subsequent to their first clinical and then molecular diagnosis of Clericuzio-type poikiloderma with neutropenia syndrome due to mutation of USB1gene. Patient 1 always expressed the most severe phenotype, while patients 2 and 3 showed an intermediate and mild phenotype, respectively, as observed since their first clinical evaluation. None of the patients developed skin cancer and/or myelodysplastic disorders considering the peripheral haematological findings. Lens opacity, never reported before, was found in two of the three patients.The long term follow-up observations confirm the stability over time of the pronounced intra-familial heterogeneity of clinical manifestations observed prior to and upon molecular diagnosis. We conclude that prolonged follow-up is an adjunct tool to monitor intra-familial variability of PN clinical spectrum which may favour surveillance of more serious complications of the disease among siblings, when a patient-specific clinical expressivity is present. 相似文献
108.
Chiara Leoni Elizabeth Katherine Anna Triumbari Catello Vollono Roberta Onesimo Maria Podagrosi Valentina Giorgio Eliza Kuczynska Stefania Veltri Marco Tartaglia Giuseppe Zampino 《American journal of medical genetics. Part A》2019,179(6):940-947
Pain in individuals with RASopathies is a neglected topic in literature. In this article, we assessed prevalence and profile of pain in a sample of 80 individuals affected by RASopathies. The study sample included individuals with Noonan syndrome (N = 42), Costello syndrome (N = 17), and cardio‐facio‐cutaneous syndrome (N = 21). A set of standardized questionnaires and scales were administered (VAS/numeric scale, r‐FLACC, Wang‐Baker scale, NPSI, BPI, NCCPC‐R) to detect and characterize acute and chronic pain and to study the influence of pain on quality of life (PEDs‐QL, SF‐36) and sleeping patterns (SDSC); revision of past medical history and multisystemic evaluation was provided. Available clinical data were correlated to the presence of pain. High prevalence of acute (44%) and chronic (61%) pain was documented in the examined sample. Due to age and intellectual disability, acute pain was localized in 18/35 individuals and chronic pain in 33/49. Muscle‐skeletal and abdominal pain was more frequently reported. The intensity of acute and chronic pain interfered with daily activities in 1/3 of the sample. Pain negatively impacted on QoL and sleeping patterns. This work documents that pain is highly prevalent in RASopathies. Future studies including subjective and objective measures of pain are required to discriminate a somatosensory abnormality from an abnormal elaboration of painful stimuli at a central level. 相似文献
109.
110.
Plana M Garcia F Oxenius A Ortiz GM Lopez A Cruceta A Mestre G Fumero E Fagard C Sambeat MA Segura F Miró JM Arnedo M Lopalcos L Pumarola T Hirschel B Phillips RE Nixon DF Gallart T Gatell JM 《Journal of acquired immune deficiency syndromes (1999)》2004,36(3):791-799
OBJECTIVES: To analyze the dynamics of both HIV-1-specific CD4 and CD8 T-cell responses during structured treatment interruptions (STIs) in chronically HIV-1-infected (CHI) patients and to correlate them with the viral set point achieved. METHODS: Forty-five early-stage CHI patients who were on highly active antiretroviral therapy (HAART) for at least 1 year and underwent STI were included. Plasma viral load (VL), peripheral blood mononuclear cell (PBMC) lymphoproliferative (LPR) response to HIV p24 protein, and HIV-1 epitope-specific interferon-gammarelease from CD8 T cells were measured over a minimum study period of 2 years. RESULTS: VL set point during final STI was both significantly lower than, and positively correlated to, baseline VL (P < 0.0001: mean VL reduction 0.77 log10, and r = 0.42, P = 0.004, respectively). CD4 LPRs to p24 increased significantly (P = 0.001) between day 0 of the first STI cycle and 4th STI but decreased thereafter. VL set point during final STI was significantly and negatively correlated with LPRs to p24 at both 2nd STI and 4th STI. Nevertheless, at week 52, 12 weeks after the end of the last STI, LPRs were weak and transient in all patients and were not correlated with VL set point. Moreover, the magnitude and breadth of HIV-1-specific CD8 T-cell responses increased significantly (P < 0.0001) between day 0 and week 52. The largest increases occurred during the final STI. Even though VL reached set point by week 12 of the final STI, HIV-1-specific CD8 T-cell responses did not stabilize but rather increased until the end of the follow-up and did not correlate with plasma VL (r = 0.01, P = 0.88). CONCLUSIONS: STIs do not lead to control of viral replication in CHI patients, probably due to the fact that boosted CTL responses lack strong and durable helper T-cell responses. To reset the VL set point, new approaches that effectively augment and preserve helper T-cell responses should be investigated. 相似文献