Intercomparison of neutron personal dose equivalent measured by thermoluminescence dosimeters.

An intercomparison of neutron personal dose equivalent measured by the Harshaw thermoluminescence neutron dosimeters (TLDs) between the National Institute of Metrology of China (NIM) and the Institute for Nuclear Science and Technology of Vietnam (INST) was performed. Three sets of TLDs (each set consisting of five TLDs) were prepared for each laboratory. Each set was then irradiated to the corresponding same nominal standard value of neutron personal dose equivalent, Hp(10)n-stdi, of 1.0, 2.0, and 3.0 mSv, respectively at these two laboratories. The irradiated TLDs were then read-out at the INST using the Harshaw 4500-type TLD reader to obtain neutron personal dose equivalents at the NIM, Hp(10)n-NIMi and at the INST, Hp(10)n-INSTi, which are corresponding to different values of Hp(10)n-stdi. The TLDs' responses to different scattered components of neutrons in these two fields are also discussed. Comparisons between the corresponding pair values of Hp(10)n-NIMi and Hp(10)n-INSTi show good agreements within 10% with the standard uncertainty of 12.5% (k = 1). The measured values of Hp(10)n-NIMi and Hp(10)n-INSTi are satisfied the Trumpet curve criteria. This implies that the TLDs can be used for safety assessment of occupational neutron personal dose equivalents. This intercomparison result also confirms the capabilities of these two laboratories (i.e., NIM, INST) on deliveries of neutron personal dose equivalent standard values for calibrations.

A simplified point-of-care testing approach for preeclampsia blood biomarkers based on nanoscale field effect transistors.

Rapid diagnosis of preeclampsia is necessary to ensure timely administration of appropriate care and prevent the potentially catastrophic complications of the condition affecting both mothers and babies. While the diagnostic superiority of angiogenic blood biomarkers such as placental growth factor has recently been demonstrated, there is an urgent need to develop point-of-care (PoC) technologies that allow rapid, quantitative, and accurate testing for these markers within local communities. Towards addressing this need, here we report on a fully integrated biodiagnostic platform based on nanoscale indium oxide field effect transistor (FET) sensors. The high-performance FET sensors are integrated with blood sample processing cartridges that minimize the need for operator intervention during the assay and eliminate the need for analytical equipment. Within 40 minutes and from 30 µL of blood, the FET platform could reliably measure PlGF with a limit of detection of 0.06 pg mL-1 and a five order of magnitudes dynamic range. Pilot clinical validation in four preeclamptic pregnancies confirmed that the accuracy and reliability of the FET platform, paving the way for further development to a much-needed point-of-care preeclampsia testing.

The contribution of physical and social activity participation to social support and happiness among people with physical disabilities.

BACKGROUND: Prior studies have suggested that certain leisure activities provide health benefits to people with physical disabilities. Participation in social activities has been identified as a strong predictor of active coping strategies and social support from others. In addition, leisure-time physical activity (LTPA) has been found to be positively associated with health perceptions and quality of life. OBJECTIVES: The purpose of this study was to investigate the relationships between social activity and LTPA to social support and life satisfaction among people with physical disabilities. METHODS: Data were collected from Korean Association of Persons with Physical Disabilities. A total of 351 surveys were used. RESULTS: Results indicated that social activity, emotional and informational support, and tangible and affectionate support were significantly associated with happiness. However, there were no direct effects of LTPA and positive social interaction support on happiness. The study results showed significant direct effects of LTPA on emotional and informational support and positive social interaction. CONCLUSION: This study shows that it is important for people with physical disabilities not only to participate in LTPA, but also to be provided with opportunities for social activities. In particular, the importance of social activity to Korean people with physical disabilities as a means of receiving social support and increasing happiness was confirmed. The results suggest that practitioners need to create a variety of social activity opportunities, such as online social participation programs, community-based social programs, and social events for health.

Intravenous administration of piceatannol, an arginase inhibitor, improves endothelial dysfunction in aged mice.

Advanced age is one of the risk factors for vascular diseases that are mainly caused by impaired nitric oxide (NO) production. It has been demonstrated that endothelial arginase constrains the activity of endothelial nitric oxide synthase (eNOS) and limits NO generation. Hence, arginase inhibition is suggested to be vasoprotective in aging. In this study, we examined the effects of intravenous injection of Piceatannol, an arginase inhibitor, on aged mice. Our results show that Piceatannol administration reduced the blood pressure in aged mice by inhibiting arginase activity, which was associated with NO production and reactive oxygen species generation. In addition, Piceatannol administration recovered Ca2+/calmodulin-dependent protein kinase II phosphorylation, eNOS phosphorylation and eNOS dimer stability in the aged mice. The improved NO signaling was shown to be effective in attenuating the phenylephrine-dependent contractile response and in enhancing the acetylcholine-dependent vasorelaxation response in aortic rings from the aged mice. These data suggest Piceatannol as a potential treatment for vascular disease.

Arginase Inhibitor 2,3,5,4'-Tetrahydroxystilbene-2-O-ß-D-Glucoside Activates Endothelial Nitric Oxide Synthase and Improves Vascular Function.

Endothelial arginase constrains the activity of endothelial nitric oxide synthase by reducing nitric oxide bioavailability, which contributes to vascular diseases. During screening, we identified a novel compound from the rhizome of Polygonum multiflorum (Polygonaceae), 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (THSG), which inhibited arginase activity. THSG exhibited noncompetitive inhibition of arginase II and inhibited both arginases I and II in a dose-dependent manner. THSG-dependent arginase inhibition reciprocally increased nitric oxide production and decreased reactive oxygen species generation in aortic endothelia. These effects were associated with increased dimerization of endothelial nitric oxide synthase without changes in the protein expression levels of arginase I, arginase II, or endothelial nitric oxide synthase. In vascular tension assays, when aortic vessels from wild-type mice are incubated with THSG, responses to the nitric oxide-dependent vasorelaxant acetylcholine were augmented, but responses to an nitric oxide donor, sodium nitroprusside, were not affected. On the other hand, phenylephrine-dependent vasoconstriction was significantly retarded in THSG-treated vessels. In a high-cholesterol diet-fed atherogenic model mice (ApoE-/-), THSG improved endothelial function by enhancement of the nitric oxide-cGMP pathway. Taken together, these results suggest that THSG may exert vasoprotective effects through augmentation of nitric oxide signaling by inhibiting arginase. Therefore, THSG may be useful in the treatment of vascular diseases that are derived from endothelial dysfunction, such as atherosclerosis.

Arginase Inhibition Restores Peroxynitrite-Induced Endothelial Dysfunction via L-Arginine-Dependent Endothelial Nitric Oxide Synthase Phosphorylation.

PURPOSE: Peroxynitrite plays a critical role in vascular pathophysiology by increasing arginase activity and decreasing endothelial nitric oxide synthase (eNOS) activity. Therefore, the aims of this study were to investigate whether arginase inhibition and L-arginine supplement could restore peroxynitrite-induced endothelial dysfunction and determine the involved mechanism. MATERIALS AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with SIN-1, a peroxynitrite generator, and arginase activity, nitrite/nitrate production, and expression levels of proteins were measured. eNOS activation was evaluated via Western blot and dimer blot analysis. We also tested nitric oxide (NO) and reactive oxygen species (ROS) production and performed a vascular tension assay. RESULTS: SIN-1 treatment increased arginase activity in a time- and dose-dependent manner and reciprocally decreased nitrite/nitrate production that was prevented by peroxynitrite scavenger in HUVECs. Furthermore, SIN-1 induced an increase in the expression level of arginase I and II, though not in eNOS protein. The decreased eNOS phosphorylation at Ser1177 and the increased at Thr495 by SIN-1 were restored with arginase inhibitor and L-arginine. The changed eNOS phosphorylation was consistent in the stability of eNOS dimers. SIN-1 decreased NO production and increased ROS generation in the aortic endothelium, all of which was reversed by arginase inhibitor or L-arginine. N(G)-Nitro-L-arginine methyl ester (L-NAME) prevented SIN-1-induced ROS generation. In the vascular tension assay, SIN-1 enhanced vasoconstrictor responses to U46619 and attenuated vasorelaxant responses to acetylcholine that were reversed by arginase inhibition. CONCLUSION: These findings may explain the beneficial effect of arginase inhibition and L-arginine supplement on endothelial dysfunction under redox imbalance-dependent pathophysiological conditions.

Understanding the roles of faith-based health-care providers in Africa: review of the evidence with a focus on magnitude, reach, cost, and satisfaction.

At a time when many countries might not achieve the health targets of the Millennium Development Goals and the post-2015 agenda for sustainable development is being negotiated, the contribution of faith-based health-care providers is potentially crucial. For better partnership to be achieved and for health systems to be strengthened by the alignment of faith-based health-providers with national systems and priorities, improved information is needed at all levels. Comparisons of basic factors (such as magnitude, reach to poor people, cost to patients, modes of financing, and satisfaction of patients with the services received) within faith-based health-providers and national systems show some differences. As the first report in the Series on faith-based health care, we review a broad body of published work and introduce some empirical evidence on the role of faith-based health-care providers, with a focus on Christian faith-based health providers in sub-Saharan Africa (on which the most detailed documentation has been gathered). The restricted and diverse evidence reported supports the idea that faith-based health providers continue to play a part in health provision, especially in fragile health systems, and the subsequent reports in this Series review controversies in faith-based health care and recommendations for how public and faith sectors might collaborate more effectively.