全文获取类型
收费全文 | 4281篇 |
免费 | 262篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 108篇 |
妇产科学 | 109篇 |
基础医学 | 455篇 |
口腔科学 | 604篇 |
临床医学 | 219篇 |
内科学 | 934篇 |
皮肤病学 | 111篇 |
神经病学 | 278篇 |
特种医学 | 70篇 |
外科学 | 639篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 434篇 |
眼科学 | 131篇 |
药学 | 203篇 |
中国医学 | 64篇 |
肿瘤学 | 90篇 |
出版年
2023年 | 12篇 |
2022年 | 67篇 |
2021年 | 103篇 |
2020年 | 68篇 |
2019年 | 106篇 |
2018年 | 150篇 |
2017年 | 118篇 |
2016年 | 113篇 |
2015年 | 137篇 |
2014年 | 189篇 |
2013年 | 228篇 |
2012年 | 258篇 |
2011年 | 305篇 |
2010年 | 167篇 |
2009年 | 154篇 |
2008年 | 242篇 |
2007年 | 294篇 |
2006年 | 262篇 |
2005年 | 246篇 |
2004年 | 194篇 |
2003年 | 143篇 |
2002年 | 143篇 |
2001年 | 116篇 |
2000年 | 105篇 |
1999年 | 67篇 |
1998年 | 35篇 |
1997年 | 25篇 |
1996年 | 20篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 13篇 |
1992年 | 29篇 |
1991年 | 46篇 |
1990年 | 23篇 |
1989年 | 16篇 |
1988年 | 19篇 |
1987年 | 19篇 |
1986年 | 23篇 |
1985年 | 22篇 |
1984年 | 16篇 |
1983年 | 13篇 |
1979年 | 14篇 |
1977年 | 10篇 |
1971年 | 12篇 |
1970年 | 21篇 |
1969年 | 27篇 |
1968年 | 15篇 |
1967年 | 20篇 |
1966年 | 14篇 |
1965年 | 12篇 |
排序方式: 共有4547条查询结果,搜索用时 15 毫秒
101.
Antonio S Andrade Filho Aristidez C Queiroz Antonio C C Freire Leonardo Conrado S Lima Celso A S Filho Isolda N Amado Mittermeyer G Reis Isis Fernandes Magalh?es Theomira M A Carmo 《The Brazilian journal of infectious diseases》2007,11(4):435-438
Central nervous system (CSN) involvement in schistosomiasis is an ectopic manifestation with a large variety of clinical forms, including pseudotumoral, which occurs in isolated cases and is rare. Three patients with epidemiological indications of this pathology were examined; the clinical picture included lower-back pain irradiating to lower limbs, associated with progressive flaccid paraparesis and sphincterial disturbances in cases in which the spinal chord was involved; while in cases with encephalitic impairment, headache, dizziness and cerebellar syndrome, characterized by dysarthria and right-side dysgraphia, were present. Magnetic resonance imaging (MRI) showed a growing process in all cases; cerebrospinal fluid (CSF) characteristics and biological markers were compatible with neuroschistosomiasis (NS). Biopsy of the lesions confirmed this diagnosis in one case. After specific treatment with schistosomicides and corticosteroids, clinical, radiological and laboratorial improvement was observed. 相似文献
102.
103.
Background
Arterial gas embolism (AGE) is a clinical problem that occurs directly in cardiopulmonary bypass machines in open-heart surgeries, or indirectly (through cardiac or pulmonary right to left shunts) in dive accidents, resulting in serious morbidity and even death. Perfluorocarbon (PFC) emulsions have been used for the treatment of AGE in an animal model. We hypothesized that PFC emulsions enhance microvascular blood flow, speed bubble resolution, and oxygenation in AGE compared with saline in a model of cremaster muscle from anesthetized rats.Materials and methods
AGE was induced by direct air injection into the femoral artery ipsilateral to the studied cremaster muscle. Microhemodynamics, microvascular, and tissue oxygenation were determined before and after treatment with two different commercial PFC emulsions (C10F20, Oxycyte; Oxygen Biotherapeutics, Inc and C10F18, PHER-O2; Sanguine Corporation, Inc) compared with saline in real time using brightfield and phosphorescence microscopy.Results
Blood pressure and heart rate remained unchanged. Systemic PO2, oxygen (O2) content, and glucose were higher in PFC groups, whereas hematocrit dropped in all groups. Arteriolar blood flow went up 85% and 80% of baseline after C10F20 and C10F18 treatments, respectively, versus 11% after saline treatment. Arteriolar and tissue PO2, and O2 delivery were higher in PFC groups compared with the control group. There was an increase in arteriolar blood flow, reduction in diffusional resistance of O2 in the plasma, and improved tissue oxygenation.Conclusions
Administration of PFC emulsions in AGE is superior to saline primarily because of surfactant properties along with air bubble reabsorption. 相似文献104.
Edjair V. Cabral Leucio D. Vieira Bruna R. M. Sant'Helena Valdilene S. Ribeiro Juliane S. Farias Regina S. Aires Silvania T. Paz Humberto Muzi‐Filho Ana D. Paixo Adalberto Vieyra 《Clinical and experimental pharmacology & physiology》2019,46(12):1151-1165
Maternal salt overload programs cardiovascular and renal alterations in the offspring. However, beneficial and harmful effects of high dose vitamin E supplementation have been described in humans and animals. We investigated the hypothesis as to whether cardiac and renal alterations can be programmed by gestational salt overload, and can become further modified during lactation and after weaning. Male Wistar rats were used, being the offspring of mothers that drank either tap water or 0.3 mol/L NaCl for 20 days before and during pregnancy. α‐Tocopherol (0.35 g/kg) was administered to mothers daily during lactation or to their offspring for 3 weeks post‐weaning. Systolic blood pressure (tcSBP) was measured in juvenile rats aged 210 days. The response of mean arterial pressure (MAP) and heart rate (HR) to intravenous infusion of angiotensin II (Ang II) was also examined. Left ventricle plasma membrane (PMCA) and sarcoplasmic reticulum Ca2+‐ATPase (SERCA) activities, and certain parameters of renal function, were measured. Maternal saline programmed for increased body mass and kidney mass/body mass ratio, increased tcSBP, increased mean arterial pressure and heart rate with anomalous response to infused Ang II. In the heart, saline increased PMCA and α‐Tocopherol per se increased PMCA/SERCA. In the kidney, the most remarkable result was the silent saline programming of CrCl, which was sensitized for a sharp decrease after α‐Tocopherol. In conclusion, the combination of maternal saline overload and high α‐Tocopherol immediately after birth leads to simultaneous cardiovascular and renal alterations in the young offspring, like those encountered in type V cardiorenal syndrome. 相似文献
105.
106.
M. M. Azuma R. O. Samuel J. E. Gomes‐Filho E. Dezan‐Junior L. T. A. Cintra 《International endodontic journal》2014,47(7):615-621
The aim of this review was to examine current knowledge of the role of interleukin‐6 (IL‐6) in apical periodontitis (AP) pathogenesis as an inflammatory or pro‐inflammatory cytokine. It also looked at whether IL‐6 could serve as a measure for differential diagnosis or as a biomarker that can further predict the progression of bone resorption. A systematic review relating to AP and IL‐6 was made via PubMed, BIOSIS, Cochrane, EMBASE and Web of Science databases using keywords and controlled vocabulary. Two independent reviewers first screened titles and abstracts and then the full texts. The reference lists of the identified publications were examined for additional titles. Eighteen papers were studied in total. In vitro studies (n = 6) revealed that IL‐6 is present in AP, and its levels are proportional to the size of the periapical lesions. Neutrophils and macrophages resident in these lesions can produce IL‐6 in vitro after a bacterial stimulus. Animal studies (n = 5) showed that IL‐6 is present in AP and that osteoblasts can produce IL‐6 in vivo. On the other hand, two studies using IL‐6 knockout mice revealed larger periapical lesions when compared with control groups, demonstrating IL‐6's role as an anti‐inflammatory cytokine. In human studies (n = 7), IL‐6 was identified in AP, and its levels were higher in symptomatic, epithelialized and large lesions than in asymptomatic and small lesions. These data lead to the conclusion that IL‐6 may play a pro‐inflammatory role, increasing its levels and reabsorbing bone in the presence of infections. When IL‐6 is not present, other cytokines such as IL‐1 and TNF‐α induce bone resorption. Further studies about the relationship between AP development and the cytokine network must be performed to establish the exact role of each cytokine in the inflammatory process. 相似文献
107.
Marcello Oliveira Barbosa Alexandre Foga?a Cristante Gustavo Bispo dos Santos Ricardo Ferreira Raphael Martus Marcon Tarcisio Eloy Pessoa de Barros Filho 《Clinics (S?o Paulo, Brazil)》2014,69(8):559-564
OBJECTIVES
: To evaluate the neuroprotective effect of epidural hypothermia in rats subjected to experimental spinal cord lesion.METHODS:
Wistar rats (n = 30) weighing 320-360 g were randomized to two groups (hypothermia and control) of 15 rats per group. A spinal cord lesion was induced by the standardized drop of a 10-g weight from a height of 2.5 cm, using the New York University Impactor, after laminectomy at the T9-10 level. Rats in the hypothermia group underwent epidural hypothermia for 20 minutes immediately after spinal cord injury. Motor function was assessed for six weeks using the Basso, Beattie and Bresnahan motor scores and the inclined plane test. At the end of the final week, the rats'' neurological status was monitored by the motor evoked potential test and the results for the two groups were compared.RESULTS:
Analysis of the Basso, Beattie and Bresnahan scores obtained during the six-week period indicated that there were no significant differences between the two groups. There was no significant difference between the groups in the inclined plane test scores during the six-week period. Furthermore, at the end of the study, the latency and amplitude values of the motor evoked potential test were not significantly different between the two groups.CONCLUSION:
Hypothermia did not produce a neuroprotective effect when applied at the injury level and in the epidural space immediately after induction of a spinal cord contusion in Wistar rats. 相似文献108.
109.
Juliana Silveira Lima de Castro Evandra Cristina Vieira da Rocha Vanessa Assis do Vale Paula Mendona Oswaldo Wiliam Marques Jr. Eloy Taglieri Francisco Susumu Correa Koyama Celso Augusto Milani Cardoso Filho Wilson Toshihiko Nakagawa 《The Turkish journal of gastroenterology》2021,32(8):616
BackgroundRectal neuroendocrine tumors (R-NET) represent the most frequent of gastroenteropancreatic neuroendocrine neoplasms (NEN-GEP) according to the United States Surveillance, Epidemiology, and End Results database. With an annual percentage of occurrence increasing to 8.2% of all rectal neoplasms, R-NET affect less than 2% and are reported in only 0.05% to 0.07% of patients undergoing colorectal cancer (CRC) screening. The primary objective of this study was to assess the risk factors associated with R-NET greater than 10 mm. As a secondary objective, it was also aimed to evaluate the response to endoscopic treatment.Methods: This was a retrospective study, using data collected through the analysis of medical records of colonoscopies performed from January 2008 to December 2014. Records of polypectomies were identified, and the results were searched for pathological findings of R-NET. We also gathered epidemiological data and outcomes as risk factors for lesions greater than or equal to 10 mm, with local and distant recurrence.Results: During the study period, 18 218 colonoscopies were performed and 10 865 polypoid lesions were detected and removed, 20 with R-NET anatomopathology. The detection rate was 0.1%. The risk factors associated with major lesions were Japanese ethnicity, the lack of previous cancer diagnosis, and a Ki67 index > 2%. The mean follow-up was 56.6 months, and there was no local lymph node recurrence or distant relapse.ConclusionThis study concludes that endoscopic resection is a good and effective method for treatment of Grade 1 rectal NET smaller than 11 mm, with high cure rates and low rates of local or distant relapse. 相似文献
110.
Anne M. Schultheis Ino de Bruijn Pier Selenica Gabriel S. Macedo Edaise M. da Silva Salvatore Piscuoglio Achim A. Jungbluth Kay J. Park David S. Klimstra Eva Wardelmann Wolfgang Hartmann Claus Dieter Gerharz Mareike von Petersdorff Reinhard Buettner Jorge S. ReisFilho Britta Weigelt 《Molecular oncology》2022,16(4):833
Small cell carcinoma (SCC) of the uterine cervix is a rare and aggressive form of neuroendocrine carcinoma, which resembles small cell lung cancer (SCLC) in its histology and poor survival rate. Here, we sought to define the genetic underpinning of SCCs of the uterine cervix and compare their mutational profiles with those of human papillomavirus (HPV)‐positive head and neck squamous cell carcinomas, HPV‐positive cervical carcinomas, and SCLCs using publicly available data. Using a combination of whole‐exome and targeted massively parallel sequencing, we found that the nine uterine cervix SCCs, which were HPV18‐positive (n = 8) or HPV16‐positive (n = 1), harbored a low mutation burden, few copy number alterations, and other than TP53 in two cases no recurrently mutated genes. The majority of mutations were likely passenger missense mutations, and only few affected previously described cancer‐related genes. Using RNA‐sequencing, we identified putative viral integration sites on 18q12.3 and on 8p22 in two SCCs of the uterine cervix. The overall nonsilent mutation rate of uterine cervix SCCs was significantly lower than that of SCLCs, HPV‐driven cervical adeno‐ and squamous cell carcinomas, or HPV‐positive head and neck squamous cell carcinomas. Unlike SCLCs, which are reported to harbor almost universal TP53 and RB1 mutations and a dominant tobacco smoke‐related signature 4, uterine cervix SCCs rarely harbored mutations affecting these genes (2/9, 22% TP53; 0% RB1) and displayed a dominant aging (67%) or APOBEC mutational signature (17%), akin to HPV‐driven cancers, including cervical adeno‐ and squamous cell carcinomas and head and neck squamous cell carcinomas. Taken together, in contrast to SCLCs, which are characterized by highly recurrent TP53 and RB1 alterations, uterine cervix SCCs were positive for HPV leading to inactivation of the suppressors p53 and RB, suggesting that these SCCs are convergent phenotypes. 相似文献