Individualism-Collectivism,Social Self-Control and Adolescent Substance Use and Risky Sexual Behavior

Individualism and collectivism are cultural syndromes that have been associated with adolescent problem behavior in studies conducted in the U.S. and Southeast Asia. However, research investigating the mechanisms of how cultural orientation impacts health risk behaviors has been limited. This study tested a new model explaining the relationship between cultural orientation (i.e., individualism, collectivism) and adolescent problem behavior (i.e., substance use and risky sex) in terms of interpersonal self-regulation (i.e., social self-control). As such, the study is rooted in theories of the role of culture in developing self-regulation. Participants were high school students (N = 716) from the Bashkirtostan Republic of the Russian Federation. Adolescents from the Russian Federation tend to show high prevalence of cigarette smoking and binge drinking. People of the Russian Federation in general are traditionally collectivist in orientation, although increased globalization and post-Soviet capitalism may indicate high individualist values in younger generation Russians. Using path analysis we found that in addition to having direct effects, higher individualism indirectly affected substance use and risky sexual behavior through social self-control and negative life events. Higher collectivism was found to have a direct protective effect on risky sexual behavior and a direct effect on social self-control. However, collectivism was not found to have indirect effects on substance use or risky sexual behavior. Higher individualism appears to function as a risk factor for adolescent problem behavior and this relationship may be mediated by lower social self-control. Culturally-tailored prevention programs utilizing the individualism-collectivism framework may benefit from addressing social self-control.     

Prevalence of human papillomavirus in squamous cell carcinoma of the tongue

Oncogenic human papillomaviruses (HPVs) are important agents in the genesis of gynecological cancer, and have also been implied in the genesis of oral cancer. With the purpose of evaluating the relationship between HPV and squamous cell carcinoma (SCC) of the tongue, a case-control study was performed. Fifty white male patients who were smokers and had the histological diagnosis of SCC of the tongue were selected. The control group was composed of 10 matched patients with no clinical evidence of tongue lesions. Polymerase chain reaction (PCR) was used to detect the presence of HPV genome in fresh-frozen tissue specimens from SCC of the tongue margin. Thirty-seven patients (74%) had a positive PCR for oncogenic papillomavirus, and only 1 specimen (10%) of the control group was positive for nononcogenic papillomavirus. Based on the statistical analysis of this study there was a 25.6% higher risk for SCC of the tongue to harbor oncogenic HPV than the healthy control tongue tissue.     

Anti–Trypanosoma cruzi effect of the photodynamic antiparasitic chemotherapy using phenothiazine derivatives as photosensitizers

Lasers in Medical Science - Chagas disease is endemic in Latin America and increasingly found in non-endemic countries. Its treatment is limited due to the variable efficacy and several side...     

Raman study of the repair of surgical bone defects grafted with biphasic synthetic microgranular HA + β-calcium triphosphate and irradiated or not with λ780 nm laser

The treatment of bone loss due to different etiologic factors is difficult, and many techniques aim to improve repair, including a wide range of biomaterials and, recently, photobioengineering. This work aimed to assess, through Raman spectroscopy, the level of bone mineralization using the intensities of the Raman peaks of both inorganic (～960, ～1,070, and ～1,077 cm^?1) and organic (～1,454 and ～1,666 cm^?1) contents of bone tissue. Forty rats were divided into four groups each subdivided into two subgroups according to the time of killing (15 and 30 days). Surgical bone defects were made on femur of each animal with a trephine drill. On animals of group Clot, the defect was filled only by blood clot; on group Laser, the defect filled with the clot was further irradiated. On animals of groups Biomaterial and Laser?+?Biomaterial, the defect was filled by biomaterial and the last one was further irradiated (λ780 nm, 70 mW, Φ?～?0.4 cm², 20 J/cm² session, 140 J/cm² treatment) in four points around the defect at 48-h intervals and repeated for 2 weeks. At both 15th and 30th day following killing, samples were taken and analyzed by Raman spectroscopy. At the end of the experimental time, the intensities of both inorganic and organic contents were higher on group Laser?+?Biomaterial. It is concluded that the use of laser phototherapy associated to biomaterial was effective in improving bone healing on bone defects as a result of the increasing deposition of calcium hydroxyapatite measured by Raman spectroscopy.     

Impact of prior chronic statin therapy and high-intensity statin therapy at discharge on circulating endothelial progenitor cell levels in patients with acute myocardial infarction: a prospective observational study

Background

Endothelial progenitor stem cells (EPCs) are mobilized to the peripheral circulation in response to myocardial ischemia, playing a crucial role in vascular repair. Statins have been shown to stimulate EPCs. However, neither the impact of previous statin therapy on EPC response of acute myocardial infarction (AMI) patients nor the effect of post-AMI high-intensity statin therapy on the evolution of circulating EPC levels has yet been addressed. Therefore, we aimed to compare circulating EPC levels between patients receiving long-term statin therapy before the AMI and statin-naive patients and to assess the impact of high-intensity statin therapy at discharge on the evolution of circulating EPCs post-AMI.

Methods

This is a prospective observational study of 100 AMI patients. Circulating EPCs (CD45dimCD34?+?KDR?+?cells) and their subpopulation coexpressing the homing marker CXCR4 were quantified by the high-performance flow cytometer FACSCanto II in whole blood, in two different moments: within the first 24 h of admission and 3 months post-AMI. Patients were followed up clinically for 2 years.

Results

Patients previously treated with statins had significantly higher levels of EPCs coexpressing CXCR4 (1.9?±?1.4 vs. 1.3?±?1.0 cells/1,000,000 events, p?=?0.031) than statin-naive patients. In addition, the subanalysis of diabetics (N?=?38) also revealed that patients previously on statins had significantly greater numbers of both CD45dimCD34?+?KDR?+?CXCR4+ cells (p?=?0.024) and CD45dimCD34?+?KDR?+?CD133+ cells (p?=?0.022) than statin-naive patients. Regarding the evolution of EPC levels after the AMI, patients not on a high-intensity statin therapy at discharge had a significant reduction of CD45dimCD34?+?KDR?+?and CD45dimCD34?+?KDR?+?CXCR4+ cells from baseline to 3 months follow-up (p?=?0.031 and p?=?0.005, respectively). However, patients discharged on a high-intensity statin therapy maintained circulating levels of all EPC populations, presenting at 3 months of follow-up significantly higher EPC levels than patients not on an intensive statin therapy. Moreover, the high-intensity statin treatment group had significantly better clinical outcomes during the 2-year follow-up period than patients not discharged on a high-intensity statin therapy.

Conclusion

Chronic statin therapy prior to an AMI strongly enhances the response of EPCs to myocardial ischemia, even in diabetic patients. Furthermore, high-intensity statin therapy after an AMI prevents the expected decrease of circulating EPC levels during follow-up. These results reinforce the importance of an early and intensive statin therapy in AMI patients.     

Hydrophobic sodium fluoride‐based nanocrystals doped with lanthanide ions: assessment of in vitro toxicity to human blood lymphocytes and phagocytes

In vitro immunotoxicity of hydrophobic sodium fluoride‐based nanocrystals (NCs) doped with lanthanide ions was examined in this study. Although there is already a significant amount of optical and structural data on NaYF₄ NCs, data on safety assessment are missing. Therefore, peripheral whole blood from human volunteers was used to evaluate the effect of 25 and 30 nm hydrophobic NaYF₄ NCs dissolved in cyclohexane (CH) on lymphocytes, and of 10 nm NaYF₄ NCs on phagocytes. In the concentration range 0.12–75 µg cm^?2 (0.17–106 µg ml^?1), both 25 and 30nm NaYF₄ NCs did not induce cytotoxicity when measured as incorporation of [³H]‐thymidine into DNA. Assessment of lymphocyte function showed significant suppression of the proliferative activity of T‐lymphocytes and T‐dependent B‐cell response in peripheral blood cultures (n = 7) stimulated in vitro with mitogens phytohemagglutinin (PHA) and pokeweed (PWM) (PHA > PWM). No clear dose–response effect was observed. Phagocytic activity and respiratory burst of leukocytes (n = 5–8) were generally less affected. A dose‐dependent suppression of phagocytic activity of granulocytes in cultures treated with 25 nm NCs was observed (vs. medium control). A decrease in phagocytic activity of monocytes was found in cells exposed to higher doses of 10 and 30 nm NCs. The respiratory burst of phagocytes was significantly decreased by exposure to the middle dose of 30 nm NCs only. In conclusion, our results demonstrate immunotoxic effects of hydrophobic NaYF₄ NCs doped with lanthanide ions to lymphocytes and to lesser extent to phagocytes. Further research needs to be done, particularly faze transfer of hydrophobic NCs to hydrophilic ones, to eliminate the solvent effect. Copyright © 2014 John Wiley & Sons, Ltd.     

Research on Reduction of Selected Iron-Bearing Waste Materials

During the steel production process, nearly twice as many input materials are used as compared to finished products. This creates a large amount of post-production waste, including slag, dust, and sludge. New iron production technologies enable the reuse and recycling of metallurgical waste. This paper presents an investigation on the reduction of selected iron-bearing waste materials in a laboratory rotary furnace. Iron-bearing waste materials in the form of dust, scale, and sludge were obtained from several Polish metallurgical plants as research material. A chemical analysis made it possible to select samples with sufficiently high iron content for testing. The assumed iron content limit in waste materials was 40 wt.% Fe. A sieve analysis of the samples used in the subsequent stages of the research was also performed. The tests carried out with the use of a CO as a reducer, at a temperature of 1000 °C, allowed to obtain high levels of metallization of the samples for scale 91.6%, dust 66.9%, and sludge 97.3%. These results indicate that in the case of sludge and scale, the degree of metallization meets the requirements for charge materials used in both blast furnace (BF) and electric arc furnace (EAF) steelmaking processes, while in the case of reduced dust, this material can be used as enriched charge in the blast furnace process. Reduction studies were also carried out using a gas mixture of CO and H₂ (50 vol.% CO + 50 vol.% H₂). The introduction of hydrogen as a reducing agent in reduction processes meets the urgent need of reducing CO₂ emissions. The obtained results confirm the great importance and influence of the selection of the right amount of reducer on the achievement of a high degree of metallization and that these materials can be a valuable source of metallic charge for blast furnace and steelmaking processes. At an earlier stage of the established research program, experiments of the iron oxides reduction from iron-bearing waste materials in a stationary layer in a Tammann furnace were also conducted.     

Influence of Dissolving Fe–Nb–B–Dy Alloys in Zirconium on Phase Structure,Microstructure and Magnetic Properties

This paper refers to the structural and magnetic properties of [(Fe₈₀Nb₆B₁₄)_0.88Dy_0.12]_1−xZr_x (x = 0; 0.01; 0.02; 0.05; 0.1; 0.2; 0.3; 0.5) alloys obtained by the vacuum mold suction casting method. The analysis of the phase contribution indicated a change in the compositions of the alloys. For x < 0.05, occurrence of the dominant Dy₂Fe₁₄B phase was observed, while a further increase in the Zr content led to the increasing contribution of the Fe–Zr compounds and, simultaneously, separation of crystalline Dy. The dilution of (Fe₈₀Nb₆B₁₄)_0.88Dy_0.12 in Zr strongly influenced the magnetization processes of the examined alloys. Generally, with the increasing x parameter, we observed a decrease in coercivity; however, the unexpected increase in magnetic saturation and remanence for x = 0.2 and x = 0.3 was shown and discussed.     

Evolution of the Numerical Model Describing the Distribution of Non-Metallic Inclusions in the Tundish

Continuous casting is one of the steel production stages, during which the improvement in the metallurgical purity of steel can be additionally affected by removing nonmetallic inclusions (NMIs). This can be achieved by means of various types of flow controllers, installed in the working space of the tundish. The change in the steel flow structure, caused by those flow controllers, should lead to an intensification of NMIs removal from the liquid metal to the slag. Therefore, it is crucial to understand the behavior of nonmetallic inclusions during the flow of liquid steel through the tundish, and particularly during their distribution. The presented paper reports the results of the modeling studies of NMI distribution in liquid steel, flowing through the tundish. CFD modeling methods—using different models and computation variants—were employed in the study. The obtained CFD results were compared with the results of laboratory tests (using a tundish water model). The results of the performed investigations allow us to compare both methods of modeling; the investigated phenomena were microparticle distribution and mass microparticle concentration in the model fluid. The validation of the CFD results verified the analyzed computation variants. The aim of the research was to determine which numerical model is the best for describing the studied phenomenon. This will be used as the first phase of a larger research program which will provide for a comprehensive study of the distribution of NMIs flowing through tundish steel.