全文获取类型
收费全文 | 12924篇 |
免费 | 757篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 164篇 |
儿科学 | 409篇 |
妇产科学 | 418篇 |
基础医学 | 1382篇 |
口腔科学 | 485篇 |
临床医学 | 1251篇 |
内科学 | 2779篇 |
皮肤病学 | 402篇 |
神经病学 | 825篇 |
特种医学 | 445篇 |
外科学 | 2256篇 |
综合类 | 183篇 |
一般理论 | 10篇 |
预防医学 | 789篇 |
眼科学 | 280篇 |
药学 | 920篇 |
中国医学 | 70篇 |
肿瘤学 | 682篇 |
出版年
2024年 | 17篇 |
2023年 | 150篇 |
2022年 | 319篇 |
2021年 | 579篇 |
2020年 | 380篇 |
2019年 | 527篇 |
2018年 | 553篇 |
2017年 | 419篇 |
2016年 | 437篇 |
2015年 | 458篇 |
2014年 | 645篇 |
2013年 | 718篇 |
2012年 | 1134篇 |
2011年 | 1107篇 |
2010年 | 644篇 |
2009年 | 530篇 |
2008年 | 758篇 |
2007年 | 740篇 |
2006年 | 623篇 |
2005年 | 565篇 |
2004年 | 470篇 |
2003年 | 428篇 |
2002年 | 365篇 |
2001年 | 117篇 |
2000年 | 108篇 |
1999年 | 103篇 |
1998年 | 59篇 |
1997年 | 63篇 |
1996年 | 61篇 |
1995年 | 44篇 |
1994年 | 32篇 |
1993年 | 45篇 |
1992年 | 39篇 |
1991年 | 50篇 |
1990年 | 52篇 |
1989年 | 32篇 |
1988年 | 37篇 |
1987年 | 45篇 |
1986年 | 40篇 |
1985年 | 39篇 |
1984年 | 32篇 |
1983年 | 25篇 |
1982年 | 19篇 |
1981年 | 19篇 |
1980年 | 18篇 |
1979年 | 14篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1974年 | 10篇 |
1971年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Transcranial magnetic stimulation of the occipital pole interferes with verbal processing in blind subjects 总被引:6,自引:0,他引:6
Recent neuroimaging studies in blind persons show that the occipital cortex, including the primary visual cortex (V1), is active during language-related and verbal-memory tasks. No studies, however, have identified a causal link between early visual cortex activity and successful performance on such tasks. We show here that repetitive transcranial magnetic stimulation (rTMS) of the occipital pole reduces accuracy on a verb-generation task in blind subjects, but not in sighted controls. An analysis of error types revealed that the most common error produced by rTMS was semantic; phonological errors and interference with motor execution or articulation were rare. Thus, in blind persons, a transient 'virtual lesion' of the left occipital cortex interferes with high-level verbal processing 相似文献
52.
Dina Marek‐Yagel Yoav Bolkier Ortal Barel Amir Vardi David Mishali Uriel Katz Yishay Salem Shachar Abudi Omri Nayshool Nitzan Kol Annick Raas‐Rothschild Gideon Rechavi Yair Anikster Ben Pode‐Shakked 《American journal of medical genetics. Part A》2020,182(5):987-993
The genetic basis of congenital heart malformations associated with disruption of left–right (L–R) asymmetry is broad and heterogenous, with variants in over 25 genes implicated thus far. Of these, deleterious variants in the Growth/Differentiation Factor 1 (GDF1) gene have been shown to cause heterotaxy with varied complex heart malformations of left–right patterning, in 23 individuals reported to date, either in monoallelic or biallelic state. We report three unrelated individuals exhibiting right isomerism with congenital heart defects, each originating from a consanguineous kindred of Arab‐Muslim descent. Using whole exome sequencing, a shared novel homozygous truncating c.608G > A (p.W203*) variant in the GDF1 gene was revealed as the molecular basis of their disease. Subsequently, targeted sequencing of this variant showed full segregation with the disease in these families, with a total of over 15 reportedly affected individuals, enabling genetic counseling, prenatal diagnosis, and planning of future pregnancies. Our findings further confirm the association of biallelic GDF1 variants, heterotaxy and congenital heart defects of left–right patterning, and expand the previously described phenotypic spectrum and mutational profile. Moreover, we suggest targeted screening for the p.W203* variant in relevant clinical circumstances. 相似文献
53.
Mahmoud Hassanein El-Saied A. Aly Yousf A. Abbas Samia M. El-Sigeny 《Macromolecular chemistry and physics.》1993,194(6):1817-1825
To overcome mass transfer limitations which are usually encountered on immobilizing active catalysts, cationic latex particles were used as support for the cobalt(II) complex of disodium N,N′-bis(salicylidene)ethylenediamine-5,5′-disulfonate ( 1 ). The cationic latex 2 was prepared by emulsion copolymerization of chloromethylstyrene (m/p-isomer mixture 60/40) and divinylbenzene (m/p-isomer mixture) followed by treatment with trimethylamine. The latexbound catalyst from 1 and 2 was found to considerably increase the reaction rate of the autoxidation of 2,6-di-tert-butylphenol in water as compared with the conventional polymer-free system. Reaction products were identified as the oxidative coupling product 3,3′,5,5′-tetra-tert-butyldiphenoquinone (3,3′,5,5′-tetra-tert-butyl-4,4′-dioxo-1,1′-bicyclohexa-2,5-dienylidene) and 2,6-di-tert-butyl-1,4-benzoquinone. All reactions showed an induction period before the start of dioxygen consumption. The rate of autoxidation in the three-phase mixtures of water, latex particles, and phenol droplets was not affected significantly by the method of mixing. The reaction rate increased as the concentration of 1 increased. Increasing the partial pressure of dioxygen in the range between 0,25 and 1,0 atm (2,53. 104 – 1,01. 105 Pa) gave a small increase in rate. The colloidal latex catalyst from 1 and 2 showed some loss of activity after successive runs. 相似文献
54.
Hosal SA Apel RL Freeman JL Azadian A Rosen IB LiVolsi VA Asa SL 《Endocrine pathology》1997,8(1):21-28
Molecular analyses of thyroid tumors have documented mutations in the tumor suppressor p53 gene almost exclusively in anaplastic
carcinomas. In contrast, immunohistochemistry has localized p53 in differentiated papillary and follicular thyroid cancers.
To establish the significance of p53 immunolocalization in these lesions, 78 thyroid tumors of follicular derivation were
examined. All tumors were classified by strict criteria and the extent of tumor was determined morphologically. Immunohistochemical
staining for p53 was performed on paraffin sections of formalin-fixed tumor tissue. The results of staining were correlated
with diagnosis, tumor extent and clinical outcome. Immunopositivity for p53 was diffuse and strong in all five anaplastic
carcinomas examined. There was no staining in five of six follicular adenomas. Four of nine follicular carcinomas had some
degree of nuclear staining, but this was focal; all nine tumors were confined to the thyroid at the time of examination. Of
49 papillary carcinomas, 26 were intrathyroidal, and 7 of these were occult; there was no p53 positivity in any occult lesion
and only 5 of the 19 palpable lesions stained. In contrast, among 23 papillary carcinomas with extrathyroidal extension or
metastases, only 9 were negative for p53 immunoreactivity. Five of seven tall cell papillary carcinomas and one of two insular
carcinomas had p53 immunopositivity and this correlated with aggressive behavior. These results support the tumorigenic role
of p53 mutations postulated for anaplastic thyroid carcinomas and indicate that localization of p53 by immunohistochemistry
is a useful prognostic index of clinical behavior in differentiated thyroid carcinomas of follicular cell derivation. 相似文献
55.
Munaza Fatima Santosh Kumar Mudassar Hussain Naveed Masood Memon Anum Vighio Muhammad Asif Syed Ambreen Chaudhry Zakir Hussain Zeeshan Iqbal Baig Mirza Amir Baig Rana Jawad Asghar Aamer Ikram Yousef Khader 《JMIR Public Health and Surveillance》2021,7(5)
BackgroundHyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.ObjectiveTo address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.MethodsWe reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.ResultsA total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).ConclusionsAs this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures. 相似文献
56.
57.
Saurabh Kumar Bhushan Shah Ashok Johari Rashid Anjum Devansh Garg Rashmi Salhotra Asha Tyagi Amir Maroof Khan Anil Kumar Jain 《Indian Journal of Orthopaedics》2021,55(2):506
Covid-19 is a respiratory disease caused by coronavirus 2 (SARS-CoV-2) first identified in Wuhan, China (December 2019). The disease rapidly crossed the barrier of countries, continents and spread globally. Non-pharmaceutical measures such as social distancing, face mask, frequent hand washing and use of sanitizer remained the best available option to prevent the spread of disease. OPD, IPD admissions, elective O. Ts were curtailed. Orthopedic care was only limited to emergency and semi-urgent procedures like necrotizing fasciitis, open fracture, and compartment syndrome. These measures were taken to preserve infrastructure and manpower to manage covid-19 pandemic. The children were thought to have a low susceptibility to covid-19 as compared to an adult. Deferring the patient during pandemic has led to high orthopedic disease burden, morbidity and disease-related sequelae, hence elective care must be resumed with modified hospital infrastructure. Resumption of elective/emergent orthopedic care should be slow, phasic and strategic, much similar to unlocking. Cases must be stratified depending on covid status and severity. Dedicated O.Ts with neutral/negative pressure and HEPA filter for covid positive and suspected patients are to be used. All symptomatic and suspected patients should be investigated for covid-19 by RT-PCR, blood counts and CT scan. Regional anaesthesia should be preferred to General anaesthesia. Power drill/saw/burr/pulse lavage should be minimized to avoid aerosol generation. Postoperatively continuous surveillance and monitoring to be done for covid related symptoms. Medical institutes rapidly shifted to the online mode of education. Blended learning (virtual & physical) and imparting skills have to be continued in post covid phase with equitable distribution of teaching hours to students of different years. 相似文献
58.
59.
Vikas S. Gupta Amir M. Khan Ashley H. Ebanks Pamela A. Lally Kevin P. Lally Matthew T. Harting 《Journal of pediatric surgery》2021,56(4):697-699
PurposeThere is a known association between Cornelia de Lange syndrome (CdLS) and congenital diaphragmatic hernia (CDH), with CDH being the cause of death in 5%–20% of CdLS cases. We aimed to identify and describe patients with CDLS and CDH. We hypothesized that CdLS would be associated with high-risk CDH and poor outcomes.MethodsCDH Study Group patients from 1995 to 2019 were included. Those with CdLS were reviewed retrospectively. Rates of repair and outcomes were compared between patients with and without CdLS.ResultsWe identified 9,251 CDH patients. Of those, 21 had confirmed CdLS. CdLS patients had a lower birth weight (2.2 ± 0.57 kg) than non-CdLS patients (2.9 ± 0.64 kg) (p < 0.001). 5-min Apgar scores were lower in CdLS patients (6, 4–7) than non-CdLS patients (7, 5–8) (p = 0.014). Only 33% of CdLS patients underwent diaphragmatic repair compared to 84.2% of non-CdLS patients (p < 0.001). Mortality was 76% for CdLS patients compared with 29% for non-CdLS patients (p < 0.001). Of the 7 CdLS patients who underwent repair, 5 survived to hospital discharge.ConclusionsInfants with CdLS and CDH have a poor prognosis. However, CdLS patients who undergo repair can survive to discharge; therefore, the concomitant diagnosis of CdLS and CDH is not necessarily a contraindication to repair. Early recognition of these anomalies can assist with counseling and prognostication.Type of studyRetrospective comparative studyLevel of evidenceIII 相似文献
60.
Tsilimigras Diamantis I. Dalmacy Djhenne Hyer J. Madison Diaz Adrian Abbas Alizeh Pawlik Timothy M. 《Annals of surgical oncology》2021,28(13):8162-8171
Annals of Surgical Oncology - Racial/ethnic disparities in cancer outcomes may relate to variations in receipt of National Comprehensive Cancer Network (NCCN) guideline compliant... 相似文献