全文获取类型
收费全文 | 1555篇 |
免费 | 139篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 31篇 |
妇产科学 | 15篇 |
基础医学 | 223篇 |
口腔科学 | 22篇 |
临床医学 | 184篇 |
内科学 | 347篇 |
皮肤病学 | 12篇 |
神经病学 | 135篇 |
特种医学 | 66篇 |
外科学 | 276篇 |
综合类 | 56篇 |
一般理论 | 2篇 |
预防医学 | 96篇 |
眼科学 | 20篇 |
药学 | 80篇 |
肿瘤学 | 121篇 |
出版年
2023年 | 24篇 |
2022年 | 22篇 |
2021年 | 60篇 |
2020年 | 44篇 |
2019年 | 56篇 |
2018年 | 69篇 |
2017年 | 41篇 |
2016年 | 44篇 |
2015年 | 54篇 |
2014年 | 70篇 |
2013年 | 69篇 |
2012年 | 106篇 |
2011年 | 109篇 |
2010年 | 59篇 |
2009年 | 52篇 |
2008年 | 75篇 |
2007年 | 88篇 |
2006年 | 50篇 |
2005年 | 56篇 |
2004年 | 87篇 |
2003年 | 67篇 |
2002年 | 61篇 |
2001年 | 21篇 |
2000年 | 32篇 |
1999年 | 32篇 |
1998年 | 23篇 |
1997年 | 14篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 7篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1981年 | 4篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1972年 | 4篇 |
1969年 | 3篇 |
1967年 | 3篇 |
1938年 | 3篇 |
排序方式: 共有1696条查询结果,搜索用时 15 毫秒
1.
Marcus P Kennedy Raymond D Coakley Scott H Donaldson Robert M Aris Kathy Hohneker Joel P Wedd Michael R Knowles Peter H Gilligan James R Yankaskas 《Journal of cystic fibrosis》2007,6(4):267-273
BACKGROUND: The impact of infection with Burkholderia gladioli in cystic fibrosis, other chronic airway diseases and immunosuppressed patients is unknown. METHODS: A six-year retrospective review of all patients with B. gladioli infection was performed in a tertiary referral center with cystic fibrosis and lung transplantation programs. In addition, a targeted survey of all 251 lung transplant recipients was performed. Available B. gladioli isolates were analyzed via pulsed field gel electrophoresis. RESULTS: Thirty-five patients were culture positive for B. gladioli, including 33 CF patients. No bacteremia was identified. Isolates were available in 18 patients and all were genetically distinct. Two-thirds of these isolates were susceptible to usual anti-pseudomonal antibiotics. After acquisition, only 40% of CF patients were chronically infected (> or =2 positive cultures separated by at least 6 months). Chronic infection was associated with resistance to > or =2 antibiotic groups on initial culture and failure of eradication after antibiotic therapy. The impact of acquisition of B. gladioli infection in chronic infection was variable. Three CF patients with chronic infection underwent lung transplantation. One post-transplant patient developed a B. gladioli mediastinal abscess, which was treated successfully. CONCLUSIONS: The majority of patients' culture positive for B. gladioli at our center have CF. B. gladioli infection is often transient and is compatible with satisfactory post-lung transplantation outcomes. 相似文献
2.
Optimal Selection of Sib Pairs from Random Samples for Linkage Analysis of a QTL Using the EDAC Test
Percentages of extremely concordant and extremely discordant sib pairs are calculated that maximize the power to detect a quantitative trait locus (QTL) under a variety of circumstances using the EDAC test. We assume a large fixed number of randomly sampled sib pairs, such as one would hope to find in the large twin registries, and limited resources to genotype a certain number of selected sib pairs. Our aim is to investigate whether optimal selection can be achieved when prior knowledge concerning the QTL gene action, QTL allele frequency, QTL effect size, and background (residual) sib correlation is limited or absent. To this end we calculate the best selection percentages for a large number of models, which differ in QTL gene action allele frequency, background correlation, and QTL effect size. By averaging these percentages over gene action, over allele frequency, over gene action, and over allele frequencies, we arrive at general recommendations concerning selection percentages. The soundness of these recommendations is subsequently in a number of test cases. 相似文献
3.
Conor Armstrong Séamus S. Napier Robert C. Boyd Terry A. Gregg 《Journal of oral pathology & medicine》2004,33(4):246-248
Histological examination of the deciduous teeth in two cases of segmental odontomaxillary dysplasia (SOMD) showed fibrous enlargement of the pulps, an irregular pulp/dentine interface displaying many pseudoinclusions and pulp stones. There were tubular defects in the coronal dentine from pulp horn to cusp tip, an irregular tubular structure to the circumpulpal dentine of the apical half, a focally deficient odontoblast layer and widespread external resorption. Together with the clinical features of unilateral maxillary enlargement, upper alveolar expansion in the distal segment, increased spacing and delayed eruption of the deciduous molars and absence of premolar teeth, these histological appearances allow distinction of this condition from fibrous dysplasia (FD), segmental hemifacial hypertrophy (SHH) and regional odontodysplasia (ROD). 相似文献
4.
Marianna Perdikouri Gillian Rathbone Nick Huband Conor Duggan 《Annals of clinical psychiatry》2007,19(1):17-23
BACKGROUND: Antisocial personality disorder (ASPD) in DSM-IV is unique among personality disorder diagnoses in requiring the individual to satisfy a number of childhood criteria in addition to relevant traits exhibited in adulthood. We examined the validity of this childhood requirement. METHODS: Personality disordered individuals assessed using the International Personality Disorder Examination and exhibiting a sufficient number of adult antisocial traits to meet criterion A of DSM-IV were subdivided into those who exhibited antisocial traits in both adulthood and childhood and those who had such traits in adulthood only. The two groups were then compared on a number of historical, clinical, and self-report measures. RESULTS: Thirty individuals meeting both childhood and adult criteria (ASPD) were compared with 39 meeting adult antisocial criteria only (ASS). Few differences were found between the two groups on the measures examined, although those in the ASPD group appeared more severe and had higher anger scores on the STAXI-2 psychometric test. CONCLUSIONS: This failure to find clinically important differences between the two groups is in agreement with previous reports and needs to be taken into account in future revisions of ASPD in DSM. 相似文献
5.
A longitudinal model based on the simplex model is presented to analyze simultaneously means and covariance structure using univariate longitudinal twin data. The objective of the model is to decompose the mean trend into components which can be attributed to those genetic and environmental factors which give rise to phenotypic individual differences and a component of unknown constitution which does not involve individual differences. Illustrations are given using simulated data and repeatedly measured weight obtained in a sample of 82 female twin pairs on six occasions. 相似文献
6.
Peter H. Gilligan L. R. McCarthy Brenda K. Bissett 《Journal of clinical microbiology》1981,13(4):643-645
A case report describing Capnocytophaga ochracea (Bacteroides ochraceus) septicemia in a 21-year-old male patient receiving chemotherapy for acute lymphocytic leukemia is presented. The unusual features of this organism are discussed together with a review of the literature. 相似文献
7.
Alan Ma Sunita Gurnasinghani Edwin P. Kirk Conor McClenaghan Gautam K. Singh Dorothy K. Grange Chetan Pandit Yung Zhu Tony Roscioli George Elakis Michael Buckley Bhavesh Mehta Philip Roberts Jonathan Mervis Andrew Biggin Colin G. Nichols 《American journal of medical genetics. Part A》2019,179(8):1585-1590
Cantú syndrome (CS), characterized by hypertrichosis, distinctive facial features, and complex cardiovascular abnormalities, is caused by pathogenic variants in ABCC9 and KCNJ8 genes. These genes encode gain‐of‐function mutations in the regulatory (SUR2) and pore‐forming (Kir6.1) subunits of KATP channels, respectively, suggesting that channel‐blocking sulfonylureas could be a viable therapy. Here we report a neonate with CS, carrying a heterozygous ABCC9 variant (c.3347G>A, p.Arg1116His), born prematurely at 32 weeks gestation. Initial echocardiogram revealed a large patent ductus arteriosus (PDA), and high pulmonary pressures with enlarged right ventricle. He initially received surfactant and continuous positive airway pressure ventilation and was invasively ventilated for 4 weeks, until PDA ligation. After surgery, he still had ongoing bilevel positive airway pressure (BiPAP) requirement, but was subsequently weaned to nocturnal BiPAP. He was treated for pulmonary hypertension with Sildenafil, but failed to make further clinical improvement. A therapeutic glibenclamide trial was commenced in week 11 (initial dose of 0.05 mg–1 kg–1 day–1 in two divided doses). After 1 week of treatment, he began to tolerate time off BiPAP when awake, and edema improved. Glibenclamide was well tolerated, and the dose was slowly increased to 0.15 mg?1 kg?1day?1 over the next 12 weeks. Mild transient hypoglycemia was observed, but there was no cardiovascular dysfunction. Confirmation of therapeutic benefit will require studies of more CS patients but, based on this limited experience, consideration should be given to glibenclamide as CS therapy, although problems associated with prematurity, and complications of hypoglycemia, might limit outcome in critically ill neonates with CS. 相似文献
8.
Selective and differential medium for recovery of Pseudomonas cepacia from the respiratory tracts of patients with cystic fibrosis. 总被引:8,自引:7,他引:8 下载免费PDF全文
D F Welch M J Muszynski C H Pai M J Marcon M M Hribar P H Gilligan J M Matsen P A Ahlin B C Hilman S A Chartrand 《Journal of clinical microbiology》1987,25(9):1730-1734
A selective and differential medium, OFPBL (oxidation-fermentation base supplemented with agar, lactose, and two antimicrobial agents), for the isolation of Pseudomonas cepacia from respiratory specimens of patients with cystic fibrosis was developed and tested. Among 725 specimens submitted from seven centers over a 4- to 6-month period, 58 (8%) yielded P. cepacia on OFPBL; only 19 of these were recovered on MacConkey or sheep blood agar (P less than 0.001). No isolate was recovered on MacConkey or sheep blood agar alone. Ranges of recovery rates among centers were 0 to 15% on OFPBL and 0 to 10% on MacConkey or sheep blood agar. Ninety percent of P. cepacia isolates were detected on OFPBL in less than or equal to 3 days. Other nonfermenters and yeasts isolated on OFPBL were distinguished from P. cepacia by failure to acidify the medium. The new medium was clearly superior to MacConkey and sheep blood agars for the isolation of P. cepacia from the respiratory secretions of patients with cystic fibrosis. 相似文献
9.
Immunological relationships between cholera toxin and Escherichia coli heat-labile enterotoxin. 总被引:2,自引:1,他引:2 下载免费PDF全文
The antigenic relationships between heat-labile enterotoxin (LT) produced by a human strain of enterotoxigenic Escherichia coli (strain 286C2) and cholera toxin (CT) were examined by using antisera raised against LT and CT and specific antisera prepared against each subunit of both enterotoxins. Double immunodiffusion analysis revealed reactions of partial identity between the A subunits of LT and CT, as well as between the B subunits. Rabbit antisera raised against LT subunit A reacted with only subunit A, whereas rabbits immunized with LT subunit B produced antibodies which reacted with only subunit B. A high degree of CT neutralization was observed with antisera raised against LT. Data from neutralization assays with specific antisera to each enterotoxin showed that LT was more effectively neutralized by homologous anti-LT than CT (3.7-fold); however, anti-CT was only slightly more effective in neutralization of homologous CT compared with LT (1.9-fold). In contrast, antisera raised against the B subunit of CT (choleragenoid) exhibited significantly higher neutralization activity against CT than LT (5.8-fold); however, the amount of CT neutralized by anticholeragenoid was less (4.1-fold) than anti-CT. These results suggested that anti-CT serum contained neutralizing antibodies reactive with a shared determinant formed by interaction of the A and B subunits, whereas anti-LT and anti-choleragenoid sera did not. Sensitive solid-phase radioimmunoassays were developed to examine the affinity and degree of specificity involved in homologous and heterologous antigen-antibody interactions between LT, CT, their subunits, and specific antibodies. Only unlabeled LT competed with radiolabeled LT in polystyrene tubes coated with anti-LT, and only unlabeled CT competed with radiolabeled CT in tubes coated with anti-CT. However, when radiolabeled CT was incubated in tubes coated with anti-LT, competitive inhibition responses were observed with both unlabeled toxins. When radiolabeled LT was incubated with tubes coated with anti-CT, competitive inhibition responses were observed with both unlabeled toxins. Similar competitive inhibition responses were observed with the A subunits of LT and CT and with the B subunits using antisera specific for the subunits of each enterotoxin. Double immunodiffusion analysis and radioimmunoassay data supported the presence of unique and shared immunodeterminants in each subunit. 相似文献
10.
Clinical stage I seminomas are effectively treated with surgery raising concerns as to when to give adjuvant radiation therapy given the risk of secondary malignancies. A recent randomized trial found tumor size and rete testis invasion to be the strongest predictors of relapse in clinical stage I seminomas. These 2 parameters may be surrogate measures of tumor volume. Intertubular seminoma (ITS) of the testis describes the presence of neoplastic germ cells within the interstitium of the testis. These cells are detected away from the main macroscopic mass. Because ITS can infiltrate in a 3-dimensional fashion, it may also represent a measure of tumor volume not usually noted in standard pathology reporting. The goal of this study was to determine the incidence of ITS in pure seminomas and its association with other prognostic parameters. One hundred twenty consecutive pure seminomas surgically removed between 1998 and 2003 were evaluated. ITS was defined as the presence of an interstitial or intertubular growth pattern of tumor cells, which was noncontiguous with the main tumor and present at least 3 high-power fields away from the tumor mass. The average tumor size was 3.4 cm. Of the entire cohort of patients, which included pathological stages T1 through T3, 11% had invasion through the tunica albuginea, 51% had rete testis invasion, 51% had lymphovascular invasion, 93% had associated intratubular germ-cell neoplasia, and 36% had ITS. ITS was significantly associated with rete testis invasion ( P = .001). Logistic regression analysis looking at ITS, tumor size, patient age, and lymphovascular invasion revealed that only ITS was associated with rete testis invasion (RR, 4.1, P < .0001). ITS is present in a significant proportion of pure seminomas and has a significant association with rete testis invasion. The presence of ITS may therefore be an important prognostic factor, not only because it alters the calculated size of the tumor but also because it has an association with rete testis invasion. 相似文献