全文获取类型
收费全文 | 230篇 |
免费 | 73篇 |
国内免费 | 1篇 |
专业分类
儿科学 | 12篇 |
妇产科学 | 6篇 |
基础医学 | 33篇 |
口腔科学 | 2篇 |
临床医学 | 15篇 |
内科学 | 54篇 |
皮肤病学 | 10篇 |
神经病学 | 17篇 |
特种医学 | 58篇 |
外科学 | 24篇 |
综合类 | 14篇 |
预防医学 | 19篇 |
眼科学 | 5篇 |
药学 | 23篇 |
肿瘤学 | 12篇 |
出版年
2022年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2014年 | 4篇 |
2013年 | 7篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 11篇 |
2000年 | 2篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 14篇 |
1996年 | 15篇 |
1995年 | 16篇 |
1994年 | 12篇 |
1993年 | 14篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 19篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1970年 | 4篇 |
1968年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有304条查询结果,搜索用时 93 毫秒
81.
T W O''Neill G King I M Graham J Molony B Bresnihan 《Annals of the rheumatic diseases》1992,51(5):652-654
Twenty four patients with ankylosing spondylitis of 10 or more years' duration were assessed for evidence of cardiac disease. Seven patients (29%) had evidence of cardiac disease, including one patient with a pericardial effusion, three with conduction abnormalities, and two with aortic incompetence. Aortic incompetence in one patient was clinically silent and was detected only with Doppler echocardiography. This patient had, in addition, thickening of the posterior aortic wall, an echocardiographic feature not previously described in ankylosing spondylitis. There was no evidence of aortic valve disease in a control group matched for age and sex. Patients with ankylosing spondylitis and cardiac abnormalities were older, had a longer disease duration, and more peripheral joint disease than those without cardiac abnormalities. Doppler echocardiography is a useful technique in the assessment of cardiac disease in ankylosing spondylitis and may detect aortic valve disease at an early preclinical stage. 相似文献
82.
Arnold M. Weissler MD FACC William W. O''Neill MD Young H. Sohn MD Richard S. Stack MD Phillip C. Chew Allen H. Reed PhD 《The American journal of cardiology》1981,48(6):995-1002
This study tested the hypothesis that left ventricular global performance as assessed from systolic time intervals provides a prognostic indicator in patients with coronary artery disease. The ratio of preejection period to left ventricular ejection time () was determined in 136 patients an average of 14.3 months (standard deviation 2 months) after a clinically documented acute myocardial infarction. The patients were followed up a minimum of 24 and an average of 43 ± 15 months. Coronary arteriography was performed within 48 hours of determination of the ratio. The cumulative 5 year survival rate was 70 percent for the entire series; it was 93 percent for patients with a normal ratio (0.42 or less) and 57 percent for patients with an abnormal ratio (greater than 0.42) (p < 0.001).There was diminishing cumulative survival with increasing extent of coronary arterial obstruction (p < 0.01). Among patients with a normal ratio and one, two or three vessel disease, the 5 year survival rate was 97, 92 and 87 percent, respectively. Among patients with an abnormal ratio, the respective rates were 82, 51 and 41 percent. Multivariate analysis of factors shown to vary significantly between groups with a normal or abnormal ratio or to have independent prognostic value (age greater than 60 years, angina pectoris, dyspnea, multiple sites of myocardial infarction on electrocardiography, third sound gallop, and cardiothoracic ratio greater than 0.5 on chest roentgenography) revealed that only a cardiothoracic ratio greater than 0.5 added significant predictive information to that of the ratio. The presence of dyspnea, a third or fourth sound gallop and a cardiothoracic ratio greater than 0.5, alone or in combination, did not permit accurate segregation of the patients with a normal or abnormal ratio.Determination of the ratio permits stratification of patients with a previous myocardial infarction into groups with markedly divergent survival patterns. The level of resting left ventricular performance in such patients constitutes a more potent prognostic indicator than does the extent of coronary arterial occlusive disease. 相似文献
83.
Chloramphenicol-induced bone marrow injury: possible role of bacterial metabolites of chloramphenicol 总被引:1,自引:0,他引:1
To explore the potential role of some bacterial metabolites of chloramphenicol (CAP) in CAP-induced hematotoxicity, we examined their cytotoxic effects on bone marrow cells in vitro using a number of cytotoxicity parameters. Among the metabolites tested, dehydro-CAP (DHCAP) and p-nitrophenyl-2-amino-3 hydroxypropanone-HCI (NPAP) were more toxic than CAP. DHCAP was at least as toxic as nitroso-CAP. At concentrations of less than or equal to 10(-4) mol/L, DHCAP caused total irreversible inhibition of myeloid colony (CFU-GM) growth and 80% inhibition of DNA synthesis in human bone marrow. Incubation of human bone marrow cells with 10(-4) mol/L nitroso-CAP or DHCAP for 24 hours resulted in 75% and 65% cell death respectively. Although DHCAP was 10- to 20-fold more cytotoxic than CAP, it was only one third as effective in inhibiting mitochondrial protein synthesis, indicating that DHCAP exerts its toxic effect by alternate mechanisms. The cytotoxicity of DHCAP and its relative stability, compared to the unstable nitroso CAP, suggest that this bacterial metabolite of CAP, and possibly others, may play a significant role in CAP-induced hematotoxicity. 相似文献
84.
Effectiveness of intensified rotational combination chemotherapy for late hematologic relapse of childhood acute lymphoblastic leukemia 总被引:1,自引:3,他引:1
Relapsed acute lymphoblastic leukemia (ALL) usually carries a dire prognosis. We evaluated the effectiveness and long-term complications of intensive rotational combination chemotherapy for late hematologic relapse (median, 16 months after elective cessation of therapy) among 34 children and young adults (ages 4 to 23 years). Concurrent central nervous system (CNS) relapse was present in 3 cases and testicular relapse in 4. Secondary therapy comprised an intensive five-drug reinduction (6 weeks) followed by continuation treatment with four drug pairs, rotated weekly in 4-week cycles over 120 weeks. Intrathecal chemotherapy (methotrexate, hydrocortisone, cytarabine) was given three times during reinduction and every 8 weeks during continuation. Treatment was electively discontinued at week 120 in the absence of detectable disease. Thirty-three patients (97%) attained a second complete remission. At a median follow-up of 9.3 years (range, 4.5 to 11.4), estimates of 5-year second event-free and overall survival (+/- SE) are 65% +/- 8% and 79% +/- 7%, respectively. Eleven patients had a second relapse (9 marrow, 2 testicular) and one developed secondary myeloid leukemia. There have been no CNS relapses or deaths in remission. Treatment was well-tolerated and was given largely on an outpatient basis. Late effects are primarily endocrinologic; one child had a second malignant solid tumor (presumed related to initial radiation therapy) that was treated successfully. Intensive treatment with alternating non-cross-resistant drug pairs for late hematologic relapses of ALL is effective and well-tolerated, and produces results similar to those achieved in patients with newly diagnosed ALL. Event- free survival compares favorably with reports of other relapse regimens, including those incorporating bone marrow transplantation. 相似文献
85.
Persistence of circulating blasts after 1 week of multiagent chemotherapy confers a poor prognosis in childhood acute lymphoblastic leukemia 总被引:1,自引:5,他引:1
Gajjar A; Ribeiro R; Hancock ML; Rivera GK; Mahmoud H; Sandlund JT; Crist WM; Pui CH 《Blood》1995,86(4):1292-1295
Early response to therapy, typically assessed by bone marrow status, is predictive of outcome in childhood acute lymphoblastic leukemia (ALL). Less is known about the significance of early clearance of blast cells in peripheral blood. We reviewed medical records of all patients with ALL enrolled on St Jude Total Therapy Study XI (February 1984 to September 1988) to determine the presence of blast cells in peripheral blood at diagnosis and after 1 week of intensive induction therapy. Of the 358 patients, 59 lacked evidence of circulating blast cells at diagnosis, and data were unavailable for 2 patients. The prognostic significance of persistent circulating blast cells in the remaining 297 patients was assessed in a multivariate analysis that included known adverse prognostic factors. Persistent circulating leukemic blasts were present at day 8 in 41 patients (14%). Compared with the "blast- negative" group, these patients had a significantly higher frequency of several adverse clinical features (leukocyte count > 50 x 10(9)/L, mediastinal mass, central nervous system leukemia, T-cell phenotype, lack of CD10 expression, and L2 morphology) and a significantly poorer 5-year event-free survival (34% +/- 8% [SE] v 77% +/- 3%, P < .01). By multivariate analysis, blast cell persistence at week 1 was the most significant adverse feature in the overall cohort (relative risk, 2.9; 95% confidence interval, 1.8 to 4.8) and in an analysis limited to B- lineage cases (relative risk, 3.6; 95% confidence interval, 1.9 to 7.1). Patients identified by this simple, noninvasive measure may benefit from early modification of therapy. 相似文献
86.
87.
Manju Y Krishnan Indulakshmi Radhakrishnan Biljo V Joseph Madhavi Latha GK Ajay Kumar R Sathish Mundayoor 《BMC infectious diseases》2007,7(1):86
Background
DNA fingerprinting by IS6110-RFLP has shown a high incidence of Mycobacterium tuberculosis isolates having no and low copies of the insertion sequence in Kerala, South India. Amplified Fragment Length Polymorphism (AFLP) would scan the entire genome rather than a few repetitive elements, we thought that this technique would help us in differentiating the large reservoir of isolates from an endemic region. Here we evaluate the ability of Amplified Fragment Length Polymorphism (AFLP) to type clinical isolates. 相似文献88.
BK Mohanti DA Tandon S Bahadur GK Rath RK Tanwar P Lal BM Biswal 《Journal of Medical Imaging and Radiation Oncology》1996,40(3):287-290
Early glottic carcinomas (T1 and T2) constitute only 2% of all laryngeal cancers in our data. Seventy patients were seen between 1985 and 1992. All patients were treated by cobalt-60 small field radiotherapy using a beam directed shell. The total dose delivered was 60–65 Gy in 31 patients and 66–70 Gy in 39 patients. The follow-up period ranged from 5 to 126 months, with a mean follow up of 37 months overall and 55 months in the surgical salvage group. Radiation therapy controlled disease in 71% (50 of 70) of patients overall; 75% with T1 and 67% with T2 lesions. Total laryngectomy as salvage surgery was performed in 70% (14 of 20) of patients whose disease recurred. Ultimate control including surgical salvage occurred in 64 (91%) of 70 patients in the present study. The actuarial 5 year survival was 83 and 80% in T1 and T2 tumours, respectively (statistically insignificant). This report supports the policy of definitive irradiation, reserving surgical salvage for radiation failures in early laryngeal cancers. 相似文献
89.
Rocio A. Lopez Stuti Schoetz Kathryn DeAngelis David O''Neill Arthur Bank 《Proceedings of the National Academy of Sciences of the United States of America》2002,99(2):602-607
We have previously reported the structure of a chromatin remodeling complex (PYR complex) with Ikaros as its DNA binding subunit that is specifically present in adult murine and human hematopoietic cells. We now show that homozygous Ikaros "knockout" (null) mice lack the PYR complex, demonstrating the requirement for Ikaros in the formation of the complex on DNA. Heterozygous Ikaros null mice have about half as much PYR complex, indicating a dosage effect for both Ikaros and PYR complex. We also show that Ikaros null mice have multiple hematopoietic cell defects including anemia and megakaryocytic abnormalities, in addition to previously reported lymphoid and stem cell defects. The null mice also have a delay in murine embryonic to adult beta-globin switching and a delay in human gamma to beta switching, consistent with a previously suggested role for PYR complex in this process. Lastly, cDNA array analyses indicate that several hematopoietic cell-specific genes in all blood lineages are either up- or down-regulated in 14-day embryos from Ikaros null as compared with wild-type mice. These results indicate that Ikaros and PYR complex function together in vivo at many adult hematopoietic cell-specific genes and at intergenic sites, affecting their expression and leading to pleiotropic hematopoietic defects. 相似文献
90.
Immunofluorscence studies have shown that injection of lymphocytes from either the intestinal lamina propria (LP) or from the Peyer's patches (PP) into irradiated (1000-1250 rad) allogeneic rabbits leads to the differentiation and proliferation of IgA containing cells in the spleen, mesenteric lymph node (MLN) and intestine by day 6 and to a lesser extent by day 4. In contrast, few IgA containing cells were seen in irradiated animals not given lymphocytes or given popliteal lymph node cells. Transfer of PP lymphocytes resulted in statistically greater numbers of IgA containing cells in the recipient MLN or spleen than did transfer of LP lymphocytes. In the PP of recipient rabbits given either LP or PP lymphocytes, intercellular IgA was abundant and more IgA containing cells were seen near the PP than in sites distant from PP. These results show that IgA precursor cells are present in the intestinal LP as well as in the PP. The nature and distribution of the IgA precursor and the characteristics of the IgA repopulation are discussed. 相似文献