Determination of Optimum Compression Ratio: A Tribological Aspect

Internal combustion engines are the primary energy conversion machines both in industry and transportation. Modern technologies are being implemented to engines to fulfill today's low fuel consumption demand. Friction energy consumed by the rubbing parts of the engines are becoming an important parameter for higher fuel efficiency. Rate of friction loss is primarily affected by sliding speed and the load acting upon rubbing surfaces. Compression ratio is the main parameter that increases the peak cylinder pressure and hence normal load on components. Aim of this study is to investigate the effect of compression ratio on total friction loss of a diesel engine. A variable compression ratio diesel engine was operated at four different compression ratios which were "12.96", "15:59", "18:03", "20:17". Brake power and speed was kept constant at predefined value while measuring the in- cylinder pressure. Friction mean effective pressure ( FMEP ) data were obtained from the in cylinder pressure curves for each compression ratio. Ratio of friction power to indicated power of the engine was increased from 22.83% to 37.06% with varying compression ratio from 12.96 to 20:17. Considering the thermal efficiency , FMEP and maximum in- cylinder pressure optimum compression ratio interval of the test engine was determined as 18.8 ÷ 19.6

Seroprevalence and risk factors for toxoplasma infection among pregnant women in Aydin province, Turkey

BACKGROUND: The aims of the present study were to determine the prevalence of toxoplasmosis in pregnant women at first trimester of their pregnancy and to follow up the seroconversion for next two trimesters, and to identify the risk factors and possible contamination routes in Aydin province, Turkey. METHOD: The sample size was calculated as 423 on a prevalence of 50%, d=0.05 at a confidence level of 95% with 10% addition. It was a cross-sectional study with multistage sampling. After a questionnaire applied to the pregnant women, anti-Toxoplasma IgG antibodies were studied with ELISA and IFA, values in conflict with DA test, where IgM antibodies were studied with ELISA and for borderline or positive values of IgM avidity test was used. RESULTS: The mean age of 389 (92.9%) of pregnant women in the study was 24.28+/-4.56 years, the seroprevalence of anti-Toxoplasma IgG antibodies for toxoplasmosis was 30.1%. Seroprevalence was increased with age (p=0.001) and with drinking water consumption other than bottled water (p=0.042). No significant relations were observed between anti-Toxoplasma IgG antibodies and education level, being native or migrant, abortion history, consumption of meat, vegetable and milk/milk products, personal or kitchen hygiene habits, cat owning at home of the pregnant women. No IgM antibody was detected. CONCLUSION: One of every three pregnant women in Aydin was at risk of toxoplasmosis at the first trimester of their pregnancy. Increased seroprevalance with age was a predictable result because of increasing time of exposure. Increased seroprevalence with consumption of municipal and uncontrolled water (well/spring water) supplies was similar with latest epidemiological findings

Editorial of Special Issue of National Identities: Alevism as an ethno-religious identity: Contested boundaries

No abstract for editorial but this is the opening paragraph: This special issue on Alevism and trans/national Alevi identity critically engages with the relationship between religion, ethnicity and national identity. The core issues are as follows: • how ethnicity and religion are conceptualised for a relatively invisible ethnic group in different national contexts; • how religion and ethnicity intersect when Alevism is both a faith and an ethnic identity, especially when conceptions of that identity are contested; • how identity is shaped through state policies within different national policy contexts and how etic definitions of minority communities are constructed by the state or other agencies with the power to impose them on the community in contrast to the emic or self-definitions of Aleviness from within the Alevi community; • how despite the fragmented, heterogeneous nature of Alevi communities, there is also a sense of a single, transnational imaginary community, at least for the purposes of political assimilation/integration and activism; • how education and other arenas of political, religious and cultural engagement at local, national and transnational levels create the possibilities, both positively and negatively, for future action/policy to situate minority ethnic communities

Systemic and local antibiotic prophylaxis in the prevention of Staphylococcus epidermidis graft infection

BACKGROUND: The aim of the study was to investigate the in vivo efficacy of local and systemic antibiotic prophylaxis in the prevention of Staphylococcus (S.) epidermidis graft infection in a rat model and to evaluate the bacterial adherence to frequently used prosthetic graft materials. METHODS: Graft infections were established in the subcutaneous tissue of 120 male Wistar rats by implantation of Dacron/ePTFE grafts followed by topical inoculation with 2 × 10(7 )CFUs of clinical isolate of methicillin-resistant S. epidermidis. Each of the graft series included a control group, one contaminated group that did not receive any antibiotic prophylaxis, two contaminated groups that received systemic prophylaxis with teicoplanin or levofloxacin and two contaminated groups that received teicoplanin-soaked or levofloxacin-soaked grafts. The grafts were removed 7 days after implantation and evaluated by quantitative culture. RESULTS: There was significant bacterial growth inhibition in the groups given systemic or local prophylaxis (P < 0.05). Methicillin-resistant S. epidermidis had greater affinity to Dacron graft when compared with ePTFE graft in the untreated contaminated groups (P < 0.05). CONCLUSION: The study demonstrated that the usage of systemic or local prophylaxis and preference of ePTFE graft can be useful in reducing the risk of vascular graft infections caused by staphylococcal strains with high levels of resistance

mTOR Controls Ovarian Follicle Growth by Regulating Granulosa Cell Proliferation

We have shown that inhibition of mTOR in granulosa cells and ovarian follicles results in compromised granulosa proliferation and reduced follicle growth. Further analysis here using spontaneously immortalized rat granulosa cells has revealed that mTOR pathway activity is enhanced during M-phase of the cell cycle. mTOR specific phosphorylation of p70S6 kinase and 4E-BP, and expression of Raptor are all enhanced during M-phase. The predominant effect of mTOR inhibition by the specific inhibitor Rapamycin (RAP) was a dose-responsive arrest in the G1 cell cycle stage. The fraction of granulosa cells that continued to divide in the presence of RAP exhibited a dose-dependent increase in aberrant mitotic figures known as anaphase bridges. Strikingly, estradiol consistently decreased the incidence of aberrant mitotic figures. In mice treated with RAP, the mitotic index was reduced compared to controls, and a similar increase in aberrant mitotic events was noted. RAP injected during a superovulation regime resulted in a dose-dependent reduction in the numbers of eggs ovulated. Implications for the real-time regulation of follicle growth and dominance, including the consequences of increased numbers of aneuploid granulosa cells, are discussed

[Prevalence and genotype distribution of human papillomavirus in patients attending to gynecology polyclinics].

Human papillomavirus (HPV) infection is the most significant risk factor of the development of cervical cancer. The distribution of HPV prevalence and genotype varies widely between regions. In this study, it was aimed to investigate the prevalence and genotype distribution of HPV, retrospectively. One thousand one hundred and seventy patients who applied to the department of obstetrics and gynecology were included in this study. Samples were collected from patients for cervical HPV DNA and Pap smear. The Pap samples taken for Pap smear were fixed with alcohol and analyzed according to the modified Bethesda system. HPV identification and typing were performed using the "Linear Array HPV Genotyping Test (Roche Molecular System, USA)". Patients were divided into 5 groups due to their age. Total HPV ratio was most frequently found among the patients who were between 17-30 years old, while HR-HPV was most frequently found between 51-60 years. Nine hundred seventy-eight of 1170 (83.6%) patients had normal cytologic findings whereas 192 (16.4%) had abnormal cytologic findings. HPV was detected in 37.2% of the total patients. high-risk HPV (HR-HPV) rate was 21.2%, probable high risk (PR-HPV) rate was 6.4% and low risk HPV (LR-HPV) rate was 9.5%. When the relationship between cytologic findings and HPV was examined, normal cytology/HPV negative 67.8%; abnormal cytology/HPV negative 37.5%, normal cytology/HPV positive 32.2%, abnormal cytology/HPV positive 62.5% were detected. The highest prevalence of HPV was 8.9% with HPV 16, followed by 6, 53 and 52/53/35/58. A total of 354 patients were biopsied, 177 of whom were normal, 111 of whom were cervical intraepithelial neoplasia (CIN) 1, 66 of whom were CIN 2 and over. In the group with normal pathological findings, HR-HPV ratio was found as 15.8%, while in CIN 1 44.1% in CIN 2-3 63.6%. Sensitivity, specificity, positive predictive value, and negative predictive value of screening tests were examined in CIN 2 and more lesions. Sensitivity and specificity for HR-HPV were 63.6% and 73.3%, respectively, the same rates were 81.8% and 58.7% for HPV. The highest sensitivity was found in combination of HRHPV and Pap smear, the highest specificity in HPV. In conclusion, the HPV prevalence and genotype distribution in our study are similar to those reported in the world, but higher than previous studies in our country. These results may be due to our methodology and hospital based nature of our study group. We conclude that only smear or HR-HPV testing are not sufficient as a single pronged screening test, and that the participation of other genotypes of HPV in screening increases the sensitivity

Prevalence and genotype distribution of human papillomavirus in patients attending to gynecology polyclinics

Human papillomavirus (HPV) infection is the most significant risk factor of the development of cervical cancer. The distribution of HPV prevalence and genotype varies widely between regions. In this study, it was aimed to investigate the prevalence and genotype distribution of HPV, retrospectively. One thousand one hundred and seventy patients who applied to the department of obstetrics and gynecology were included in this study. Samples were collected from patients for cervical HPV DNA and Pap smear. The Pap samples taken for Pap smear were fixed with alcohol and analyzed according to the modified Bethesda system. HPV identification and typing were performed using the "Linear Array HPV Genotyping Test (Roche Molecular System, USA)". Patients were divided into 5 groups due to their age. Total HPV ratio was most frequently found among the patients who were between 17-30 years old, while HR-HPV was most frequently found between 51-60 years. Nine hundred seventy-eight of 1170 (83.6%) patients had normal cytologic findings whereas 192 (16.4%) had abnormal cytologic findings. HPV was detected in 37.2% of the total patients. high-risk HPV (HR-HPV) rate was 21.2%, probable high risk (PR-HPV) rate was 6.4% and low risk HPV (LR-HPV) rate was 9.5%. When the relationship between cytologic findings and HPV was examined, normal cytology/HPV negative 67.8%; abnormal cytology/HPV negative 37.5%, normal cytology/HPV positive 32.2%, abnormal cytology/HPV positive 62.5% were detected. The highest prevalence of HPV was 8.9% with HPV 16, followed by 6, 53 and 52/53/35/58. A total of 354 patients were biopsied, 177 of whom were normal, 111 of whom were cervical intraepithelial neoplasia (CIN) 1, 66 of whom were CIN 2 and over. In the group with normal pathological findings, HR-HPV ratio was found as 15.8%, while in CIN 1 44.1% in CIN 2-3 63.6%. Sensitivity, specificity, positive predictive value, and negative predictive value of screening tests were examined in CIN 2 and more lesions. Sensitivity and specificity for HR-HPV were 63.6% and 73.3%, respectively, the same rates were 81.8% and 58.7% for HPV. The highest sensitivity was found in combination of HRHPV and Pap smear, the highest specificity in HPV. In conclusion, the HPV prevalence and genotype distribution in our study are similar to those reported in the world, but higher than previous studies in our country. These results may be due to our methodology and hospital based nature of our study group. We conclude that only smear or HR-HPV testing are not sufficient as a single pronged screening test, and that the participation of other genotypes of HPV in screening increases the sensitivity. © 2019 Ankara Microbiology Society. All rights reserved

Tibolone and breast cancer

Tibolone is a relatively new drug for postmenopausal women, which is structurally related to 19‐nortestosterone derivatives and exhibits weak oestrogenic, progestogenic and androgenic activities. The effect of tibolone on breast tissue is still obscure. In vitro studies have shown conflicting results regarding the effects of tibolone on breast cells. On the other hand, although epidemiological studies show an increase in the risk of breast cancer among women treated with tibolone, accumulation of data obtained from radiological studies presents promising results. However, the safety of tibolone with regard to breast tissue needs to be investigated further, especially through well‐designed, large‐scale, randomised‐controlled trials