Flexural behavior of 3D para-aramid/phenolic/nano (MWCNT) composites

In this work, the flexure properties of nanostitched and nanoprepreg three dimensional (3D) para-aramid/phenolic composites were studied. Four types of composite were developed. They were called stitched/nano, stitched, base/nano and base. The flexure strength and modulus of the stitched/nano composites were slightly improved compared to those of the base composites due to the addition of the stitching yarn and multiwall carbon nanotubes (MWCNTs). The flexure failure of the base and base/nano structures was matrix peeling and large delaminated areas, whereas the stitched and stitched/nano composites had warp deformation and no visible matrix/fiber damage. In addition, the delaminated areas were severely restricted. The results showed that introducing the stitching fiber and multiwall carbon nanotubes in the base structure improved its out-of-plane failure properties as a form of restricted delamination and they acted as delamination barriers around the regions. Therefore, stitched/nano p-aramid/phenolic composites could be considered as damage tolerant materials.

The bending properties of four types of nanostitched and nanoprepreg three dimensional (3D) para-aramid/phenolic composite were studied. Stitched or stitched/nano p-aramid/phenolic composites could be considered as damage tolerant materials.     

Association of the angiotensinogen M235T and angiotensin-converting enzyme insertion/deletion gene polymorphisms in Turkish type 2 diabetic patients with and without nephropathy

OBJECTIVE: Recent studies have suggested an association between a deletion variant of the angiotensin-converting enzyme (ACE) gene and diabetic nephropathy. However, this finding has not been confirmed by all investigators. Furthermore, an M235T variant of the angiotensinogen (AGT) gene has been associated with hypertension, an important risk factor for the development and progression of diabetic nephropathy. RESEARCH DESIGN AND METHODS: We investigated the relationship of the ACE insertion/deletion (I/D) and AGT M235T gene polymorphisms in Turkish patients with type 2 diabetes mellitus (DM) with and without diabetic nephropathy. A total of 102 individuals were screened for the presence of the ACE I/D and AGT M235T polymorphism: 46 individuals who had type 2 DM with diabetic nephropathy and, as controls, 56 individuals who had type 2 DM without diabetic nephropathy. Gene polymorphisms were determined by the specific melting temperature (T(m)) values of the resulting amplicons after real-time online polymerase chain reaction and melting curve analysis. RESULTS: The frequencies of the ACE DD, ID, and II genotypes were 34.8%, 37.0%, and 28.3%, respectively, among type 2 diabetic patients with nephropathy, and 33.9%, 42.9%, 23.2%, respectively (P=.788), in the control subjects without diabetic nephropathy. On the other hand, the frequencies of the AGT MM, MT, and TT genotypes among the same groups were 26.1%, 52.2%, 21.7% and 26.8%, 57.1%, 16.1%, respectively (P=.758). CONCLUSIONS: There were no differences in the frequencies of the AGT M235T and ACE I/D genotypes between Turkish patients with type 2 DM with and without nephropathy.     

Comparison of differential PCR and immunohistochemistry for the evaluation of c-erbB-2 in breast carcinoma and relationship to other prognostic factors

The c-erbB-2 gene codes for a membrane receptor protein that is homologous to the epidermal growth factor receptor. Differential polymerase chain reaction (PCR) is an alternative semi-quantitative method for evaluating gene amplification and can be performed in formalin-fixed paraffin-embedded specimens. We aimed to compare differential PCR and IHC (immunohistochemistry) in the determination of c-erbB-2 status of breast cancers. Correlation between the prognostic impact of c-erbB-2 gene amplification and protein overexpression with conventional prognostic factors were also evaluated. Differential PCR and IHC for c-erbB-2 were performed on formalin-fixed paraffin sections of 60 invasive breast cancers. Results and the relation with the other prognostic parameters were compared. A highly significant degree of concordance between differential PCR and IHC in the evaluation of c-erbB-2 status of breast carcinoma was detected. Amplification and overexpression were significantly related to the number of metastatic lymph nodes, histologic grade, and lymphatic invasion but not age, histologic type, tumor size and estrogen status. We demonstrated and confirmed the importance of c-erbB-2 overexpression and amplification as a single and combined prognostic parameter together with conventional factors and confirmed that it can be detected by both immunohistochemistry and differential PCR techniques in breast carcinoma. This semi-quantitative technique provides reliable results and can be used routinely.     

Excimer laser coronary angioplasty in acute myocardial infarction

We evaluated the short-term results of percutaneous excimer laser angioplasty in acute myocardial infarction. Of the 18 patients studied, 2 were female and 16 male with a mean age of 56.6 +/- 12.1 years. Thrombolysis in myocardial infarction grades 0, 1, and 2 flow was observed in 10, 5, and 3 cases, respectively, prior to the procedure. The degree of stenosis was 97.9% +/- 5.1%. The lesion was crossed with a laser catheter in all cases, using a mean number of 808 +/- 384 laser pulses. Type C dissection developed in only 1 case (6%). Except for this case, distal flow was grade 3 in all the patients. Following the procedure, ST segment resolution exceeding 70% was achieved in 14 cases (78%) within the first 90 minutes. The success rate of laser ablation was 94% (17 patients). Stent implantation was performed in all the cases. In conclusion, laser angioplasty is an effective and reliable treatment for acute myocardial infarction.     

Risk Factors of Germinal Matrix Intraventricular Hemorrhage in Premature Infants

Objective

To determine whether some clinical parameters can be used to predict the hemorrhage and whether the relationship between these clinical variables and the grades of hemorrhage is linear.

Methods

A total of 230 premature infants, born at a gestational age less than 34 weeks were retrospectively reviewed. Germinal matrix-intraventricular hemorrhage (GM-IVH), the grade of the hemorrhage, and clinical data were assessed with a checklist. Variables were analyzed by using Mann Whitney U and Fisher’s exact tests and then multiple logistic regression analysis was used to evaluate the independent risk factors.

Findings

Resuscitation, gestational age, hypotension, multiple birth, and birth weight were found to be independent risk factors. We determined non-linear relationship between the grades of hemorrhage and the clinical parameters. But when we classified hemorrhages as grade 1, grade 2-3 and grade 4, the relationships were found linear.

Conclusion

Premature infants who had resuscitation, low gestational age, hypotension, multiple birth, and low birth weight are more likely to have GM-IVH. The relationship between the clinical variables and the grades of GM-IVH does not seem to be linear.     

Relationship of Internet addiction with cognitive style,personality, and depression in university students

Background

The aim of the study was to investigate the relationship of dysfunctional attitudes, self-esteem, personality, and depression with Internet addiction in university students.

Methods

A total of 720 university students participated in the study in Bülent Ecevit University English Preparatory School which offers intensive English courses. Students were evaluated with a sociodemographic data form, Beck Depression Inventory (BDI), Dysfunctional Attitudes Scale form A (DAS-A), Internet Addiction Scale (IAS), Rosenberg Self-Esteem Scale (RSES), and Eysenck Personality Questionnaire Revised/Abbreviated Form (EPQR-A).

Results

The results indicated that 52 (7.2%) of the students had Internet addiction. There were 37 (71.2%) men, 15 (28.8%) women in the addicted group. While the addicted groups' BDI, DAS-A perfectionistic attitude, need for approval, RSES, EPQR-A neuroticism, and psychoticism scores were significantly higher, EPQR-A lie scores were significantly lower than those of the non addicted group. According to the multiple binary logistic regression analysis, being male, duration of Internet usage, depression, and perfectionistic attitude have been found as predictors for Internet addiction. It has been found that perfectionistic attitude is a predictor for Internet addiction even when depression, sex, duration of Internet were controlled.

Conclusions

To the knowledge of the researchers, this study is the first study to show the dysfunctional attitudes in Internet addiction. It can be important to evaluate dysfunctional attitudes, personality, self-esteem and depression in people with Internet addiction. These variables should be targeted for effective treatment of people with Internet addiction in cognitive behavioral therapy.