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排序方式: 共有119条查询结果,搜索用时 109 毫秒
101.
Acquired interstitial deletions of the long arm of chromosome 5 occur frequently in the myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Recently IRF1, a putative tumor suppressor gene localized to the long arm of chromosome 5, has been shown to be deleted from the 5q- chromosome in a group of patients with MDS and AML. It has been suggested that the loss of IRF1 may be critical to the development of the 5q- syndrome. We have investigated the allelic loss of IRF1 in a group of 12 patients with MDS and a 5q deletion and 2 patients with AML and a 5q deletion. Gene dosage experiments demonstrated that 12 of 14 patients had loss of one allele of the IRF1 gene but no evidence of homozygous loss and that 2 patients with 5q- syndrome retained both copies of the gene. The retention of IRF1 on the 5q- chromosome in these two cases has been confirmed by fluorescent in situ hybridization localization using an IRF1 cosmid. Pulsed field gel electrophoresis was used to determine whether there was any evidence for structural rearrangement in the region encompassing the IRF1 gene in these two patients. No aberrant bands were detected with a range of rare cutter enzyme digests. We conclude that IRF1 maps outside the commonly deleted segment of the 5q- chromosome and that loss of IRF1 is not solely responsible for the development of the 5q- syndrome.  相似文献   
102.
Peerschke  EI; Francis  CW; Marder  VJ 《Blood》1986,67(2):385-390
Recent evidence suggests that fibrinogen binding to platelets is mediated by the 12 carboxyterminal amino acid residues of the gamma chain. Because human plasma fibrinogen gamma chains differ in mol wt and carboxyterminal amino acid sequence, we examined the effect of such gamma chain heterogeneity on platelet-fibrinogen interactions, using two fibrinogens of distinct composition, separated by ion exchange chromatography. One fibrinogen possessed only gamma chains of mol wt 50,000 (F gamma 50), the predominant gamma chain species found in plasma. The other fibrinogen possessed equal amounts of gamma chains with mol wt 50,000 and 57,500 (F gamma 50,57.5), with the longer gamma chain (gamma 57.5) possessing an amino acid extension at the carboxyterminal end. The latter fibrinogen was 50% less effective than F gamma 50 in supporting ADP-induced platelet aggregation at concentrations of .01 to 2 mg/mL. Scatchard analysis revealed no difference in the binding affinities of the two fibrinogens to ADP- treated platelets, but the amount of F gamma 50,57.5 that was bound to platelets at saturation was only 50% that of F gamma 50. Fibrinogen receptors that remained unoccupied in the presence of saturating concentrations of F gamma 50,57.5, however, could be occupied by fresh F gamma 50. Excess unlabeled F gamma 50 displaced both radiolabeled fibrinogens from activated platelets, and both fibrinogens bound to the same platelet receptor, as judged by the inhibition of binding to stimulated platelets by a monoclonal antibody directed against the glycoprotein (GP) IIb/IIIa complex. Furthermore, an intact GPIIb/IIIa complex was required for these reactions, since platelets incubated with EDTA at 37 degrees C at alkaline pH failed to aggregate and bound neither fibrinogen in response to ADP following recalcification. Approximately 50% of each fibrinogen bound irreversibly to platelets after one hour and failed to dissociate in the presence of 10 mmol/L of EDTA or excess unlabeled F gamma 50. The data demonstrate that heterodimeric F gamma 50,57.5 binds less well to platelets and supports platelet aggregation only half as well as homodimeric F gamma 50. These results support prior conclusions that the carboxyterminal portion of the gamma chain is important in platelet-fibrinogen interactions, and suggest that the 20 amino acid, hydrophobic gamma chain carboxyterminal extension of F gamma 50,57.5 may sterically hinder the interaction of this fibrinogen with platelet receptors.  相似文献   
103.
Of 1,036 children with newly diagnosed non-T, non-B acute lymphoblastic leukemia (ALL) and a demonstrated cytogenetic abnormality treated on the frontline Pediatric Oncology Group (POG) therapeutic trial 8602, there were 33 patients with trisomy 21 as the sole abnormality. Of these 33, 14 had Down syndrome (DS). Although the non-DS (NDS) trisomy 21 cases tended to be older than the DS cases, there were no other significant differences in clinicobiologic features nor in treatment outcomes between the DS and NDS groups, nor between the entire trisomy 21 group and the other chromosome abnormality group. Among NDS patients with +21 and one additional abnormality, +X, +16, -20, and structural abnormalities involving 6q or 12p were common findings. Kaplan-Meier event-free survival (EFS) curves showed a 4-year EFS of 80% (SE, 12%) in NDS trisomy 21 cases, 71% (SE, 22%) in DS cases with trisomy 21 as the sole abnormality, and 69% (SE, 2%) in cases with other chromosome abnormalities. Trisomy 21 as a sole acquired abnormality in NDS patients suggests a good prognosis.  相似文献   
104.
OBJECTIVE: To determine whether boys meeting diagnostic criteria for juvenile mania and attention deficit hyperactivity disorder (mania-ADHD) may be distinguished from boys with ADHD alone on a range of clinical and family variables. METHODOLOGY: Boys aged 9-13 years with mania-ADHD (n = 25), ADHD alone (n = 99), or no psychiatric diagnosis (n = 27) were compared on parent and teacher report Child Behavior Checklists (CBCL) and Conners Questionnaires, self-report CBCLs, patterns of comorbidity, intellectual functioning, and family variables. RESULTS: Mania-ADHD subjects had significantly higher mean ratings than ADHD only subjects on the parent CBCL for the Withdrawn, Thought Problems, Delinquent Behavior and Aggressive Behavior scales and significantly higher rates of comorbid depression, anxiety and psychotic symptoms. Other variables did not distinguish the mania-ADHD and ADHD only groups. CONCLUSIONS: These data confirm previous research indicating that the CBCL may be used to assist in the clinical identification of manic children.  相似文献   
105.
106.
107.
Pathogenesis of ductal plate malformation   总被引:4,自引:0,他引:4  
  相似文献   
108.
109.
D'Souza  VJ; Schwartz  JS; Amplatz  K 《Radiology》1978,127(2):433-436
One hundred and six patients with angina pectoris who underwent routine coronary angiography and left ventriculography were given intracoronary injection of thallium 201. The myocardial images had excellent resolution because of lack of interference from the background activity. The myocardial images and the left ventriculograms showed 94% correlation. Correlation between scans and EKG was lower. There was no correlation between the degree of coronary artery stenosis and 201Tl scan. Currently, the intracoronary injection of 201Tl at rest does not yield additional information to coronary angiography and left ventriculography.  相似文献   
110.
Caroli disease: high-frequency US and pathologic findings   总被引:5,自引:0,他引:5  
Three infants with nonobstructive bile duct dilatation (Caroli disease) are described. The bile duct pathology was associated with autosomal recessive polycystic kidney disease in two patients and with severe destruction of the renal parenchyma of unknown origin in the other. Sonograms of the liver showed, besides bile duct dilatations, intraluminal bulbar protrusions, bridge formation across dilated lumina, and portal radicles partially or completely surrounded by dilated bile ducts. Liver biopsy was performed in two patients, and in one patient, the biopsy sample confirmed the findings noted on sonograms. These findings support the hypothesis that the normal embryogenesis of intrahepatic bile ducts is arrested in the pathogenesis of this disease.  相似文献   
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