Hydrogenated derivatives of hexacoordinated metallic Cu2Si monolayer

Herein, we carried out first-principles calculations based on density functional theory to investigate the effects of surface functionalization with hydrogen atoms on structural, dynamical and electronic properties of Cu₂Si monolayer. Pristine Cu₂Si, a metallic monolayer, has a planar hexacoordinate structure. Calculations revealed that the most favorable position of a single H atom on the Cu₂Si monolayer is at the top of a Si site. Derivatives of Cu₂Si monolayer with various H concentrations were investigated, and by performing phonon calculations, it was found that there are three stable hydrogenated structures. Specific heat of these monolayers was found to increase with the hydrogen concentration at temperatures higher than 100 K. Electronically, the hydrogenated derivatives of Cu₂Si monolayer preserve the metallic character.

Herein, we carried out first-principles calculations based on density functional theory to investigate the effects of surface functionalization with hydrogen atoms on structural, dynamical and electronic properties of Cu₂Si monolayer.     

Cone-beam computed tomography evaluation of impacted and transmigrated mandibular canines: a retrospective study

Oral Radiology - The purpose of this study is to evaluate CBCT images of impacted mandibular canines in detail and to discuss implications for diagnosis and treatment. CBCT images of dental...     

An adult choledochal cyst—the magnetic resonance cholangiopancreatography findings: Report of a case

We herein report an unusual adult patient with a congenital choledochal cyst. A 28-year-old woman presented with recurrent episodes of abdominal pain in the right upper quadrant. Abdominal ultrasonography showed fusiform dilatation of the common bile duct without any obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) and magnetic resonance cholangiopancreatography (MRCP) were performed to make a precise diagnosis. No abnormal pancreatobiliary junction was detected on ERCP. The MRCP images more clearly defined the type and extent of the choledochal cyst as observed at surgery. The cyst and gallbladder were excised and a Roux-en-Y hepaticojejunostomy was performed. We also reviewed the relevant English literature and concluded that MRCP offers diagnostic information that is equivalent or superior to that of ERCP for the evaluation of type I choledochal cysts in adults and because this modality is noninvasive, it should therefore be the preferred imaging technique for an examination of adult patients with choledochal cysts.     

Prevalence of depression,its correlates among students,and its effect on health-related quality of life in a Turkish university

Objective.The aims were to investigate the prevalence of depression among university students, and to determine some of the risk factors connected to depression, and also to evaluate its effect on health-related quality of life (HRQoL).

Methods.This cross-sectional survey was conducted between 1 December 2007 and 31 January 2008 at Osmangazi University, Eskisehir, in western Turkey. The study group consisted of 822 students. The questionnaire included the students’ socio-demographic characteristics, the Beck Depression Inventory, and the Medical Outcomes Study Short Form-36 (SF-36). The data were analyzed by using chi-square, Student's t test, percent (%) ratios, and backward logistic regression analysis with a significant value of P<0.05.

Results. Of the students, 377 (45.9%) were males and 445 (54.1%) females. Overall, the prevalence of depression was 21.8% (n=179/822). Family history of depression, acne on face, any physical defect on body, smoking, alcohol consumption, and future-related occupational preoccupation were all deemed important risk factors for depression (P <0.05, for each one). It was found that, in those with depression, all the mean domain scores of SF-36 scale were lower than those without depression (P <0.05, for each one).

Conclusions.The prevalence of depression among the university students in this region of Turkey was wide-spread, affecting negatively the HRQoL of the students. For prevention and control of depression, depression information and knowledge need to be addressed by health education programs.     

Clinical significance of hepatocyte growth factor, platelet-derived growth factor-AB, and transforming growth factor-α in bone marrow and peripheral blood of patients with multiple myeloma

Angiogenesis is a process that plays an important role in the growth and progression of cancer; growing evidence suggests that neovascularization is important in hematologic malignancies. Increased angiogenic potential has been identified in multiple myeloma (MM). In this study, investigators simultaneously measured the levels of hepatocyte growth factor (HGF), platelet-derived growth factor-AB (PDGF-AB), and transforming growth factor-alpha (TGF-/ga) through enzyme-linked immunosorbent assay in the bone marrow (BM) and peripheral blood (PB) of 30 patients with MM and 10 healthy controls. Differences in HGF values in BM sera were significant (P=.001) between patients and controls. In detailed analyses of HGF, PDGF-AB, and TGF-α, according to disease stage, a significant correlation was found between disease stage and BM HGF (P=.047), BM TGF-α (P=.021), and PB PDGF-AB (P=.006), respectively. When correlations between all other parameters were analyzed, significance was noted between PB TGF-α and lactate dehydrogenase (P=.02), PB TGF-α and PB HGF (P=.002), BM TGF-α and CD38 (P=.046), BM TGF-α and BM HGF (P=.000), BM TGF-α and BM PDGF-AB (P=.048), BM HGF and PB HGF (P=.044), and BM PDGF-AB and PB PDGF-AB (P=.000). BM HGF levels had a significant effect on overall survival, with disease severity assessed in terms of disease stage (P=.0018, log-rank test). These data show that in patients with MM, high levels of BM HGF, BM TGF-α, and PB PDGF-AB were associated with advanced disease stage; in addition, HGF played a significant role in disease processing and was related to disease severity. These findings have also led to the concept of a symbiotic relationship between the growth of myeloma cells and HGF, TGF-α, and PDGF-AB in BM.     

Contrast-enhanced MR angiography of thoracic vascular malformations in children

To plan an effective management of thoracic vascular malformations, clinicians must have a clear understanding of the anatomy. Although echocardiography and angiography are the leading imaging modalities in patients with congenital cardiovascular anomalies, magnetic resonance (MR) imaging and computed tomography (CT) are valuable noninvasive adjuncts. MR imaging and CT are effective in demonstrating the complex extracardiac morphology and yield helpful information that can change the treatment plan. Although recent reports state the usefulness of multidetector CT (MDCT), in terms of pediatric population, the significance of radiation exposure should be taken into account. Thus, contrast enhanced MR angiography, as a guide in planning surgery, seems to be the best alternative to conventional angiography in the diagnosis of congenital vascular malformations. In this review, the diagnostic features of thoracic vascular malformations in pediatric population are discussed, and, the potential uses of contrast-enhanced MR angiography are emphasized with the retrospective evaluation of imaging findings in 114 examinations.     

Systemic lupus erythematosus and thrombotic thrombocytopenic purpura: a case report.

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a multisystem disorder characterised by platelet aggregation causing microvascular occlusion. Early diagnosis and utilization of plasmapheresis can provide an improvement in prognosis. CASE REPORT: A 17 year old male with classical findings of TTP was later diagnosed as systemic lupus erythematosus (SLE). Plasmapheresis resulted in the significant amelioration of the course. CONCLUSION: The coexistence of TTP and SLE may facilitate a better understanding of in the pathophysiology of TTP. These association may provide the role of autoimmunity in TTP. SLE should be considered in the differential diagnosis of patients with TTP because of therapeutic implications.