Significant parameter for controlling the partition of ambient nitrate species between HNO3(g) and NH4NO3(p).

The equilibrium between nitric acid gas (HNO3(g)) and ammonium nitrate aerosol (NH4NO3(p)) in ambient air was studied based on the monitoring data obtained using a five-stage filter-pack system, in which the fine aerosol and the coarse aerosol were separately collected; this made it possible to evaluate the actual situation of the equilibrium more accurately. The partition between HNO3(g) and coarse particulate nitrate (c-NO3-(p)), as well as that between HNO3(g) and fine particulate nitrate (f-NO3-(p)), could be evaluated individually thanks to the classification separation of the aerosol by size. The c-particle proportion c-NO3-(p)/(c-NO3-(p) + HNO3(g)) between HNO3(g) and c-NO3-(p) had a weak negative correlation (r = -0.46, p<0.001) with air temperature; in contrast, the f-particle proportion f-NO3-(p)/(f-NO3-(p) + HNO3(g)) between HNO3(g) and f-NO3-(p) had a moderate negative correlation (r = -0.80, p<0.001) with air temperature in total; furthermore, the f-particle proportion had an interesting and discriminative dependence on air temperature which could be divided into two regions by an air temperature around 15°C. The condition of high air temperature accompanied by high relative humidity frequently resulted in the deliquescent state of NH4NO3(p), providing the disconnect from the theoretical prediction for the products of [NH3(g)] and [HNO3(g)] ([NH3(g)][HNO3(g)]) by Seinfeld and Pandis (1998).

Outcomes of megavoltage radiotherapy for canine intranasal tumors and its relationship to clinical stages.

Background: Radiation therapy is considered important for the treatment of intranasal tumors in dogs and is believed to be essential for prolonging their survival. Aim: To investigate the contribution of clinical staging to improve outcomes of megavoltage radiotherapy for canine intranasal tumors. Methods: A total of 123 dogs with intranasal tumors were included in the study. Forty-eight dogs received orthovoltage radiotherapy after cytoreductive surgery (Group I), 21 received orthovoltage radiotherapy without surgery (Group II), and 54 received megavoltage radiotherapy without surgery (Group III). All cases in each group were classified into clinical stages 1-4, and the median survival time (MST) was compared for each stage in all groups. Results: The overall MST was not significantly difference among Group I (325 days), Group II (317 days), and Group III (488 days); however, Group III was prolonged than Groups I and II. The MSTs for stages 1, 2, 3, and 4 were 597, 361, 267, and 325 days in Group I; 633, 260, 233, and 329 days in Group II; and 931, 860, 368, and 176 days in Group III, respectively. The MST for stage 2 cases in Group III was significantly prolonged when compared with that in Groups I and II; no significant difference was observed at other stages; however, the MST in Group III was longer in stage 1. These results showed that megavoltage radiotherapy prolonged the MST in dogs with intranasal tumors when compared to orthovoltage radiation with or without cytoreductive surgery, and that improvements in MST at stage 2 contributed significantly to this. Conclusion: The improvement in the MST in dogs with stages 1 and 2 intranasal tumors highlights the importance of starting megavoltage radiotherapy in the early stages.

Perceived social support, coping, and stigma on the quality of life of people living with HIV in Nepal: a moderated mediation analysis.

Perceived social support, coping strategy, and internalized stigma have been linked with the quality of life (QOL) among people living with HIV (PLHIV). However, little is known about how these psychosocial factors interact with each other and affect QOL. This study incorporated a moderated mediation model to investigate whether coping strategy mediates the relationship between perceived social support and QOL, and to examine whether this mediating effect varies with the level of internalized stigma among PLHIV. A cross-sectional study was conducted among 599 PLHIV in Nepal. The multidimensional scale of perceived social support, World Health Organization Quality of Life-BREF, Brief COPE, and AIDS-related stigma scales were used to measure perceived social support, QOL, coping strategy, and internalized stigma, respectively. Data were analyzed using structural equation modeling, and moderated mediation analysis was conducted with multi-group approach. The relationship between perceived social support and QOL was significantly and partially mediated by problem-focused coping strategy. Internalized stigma significantly moderated the mediating effect of coping strategies on the association between perceived social support and QOL. For high internalized stigma group (total stigma score > 2), the effects of perceived social support on QOL were indirect (ß = 1.48; 61.0% of total effects) through the mediating effect of coping strategy, especially problem-focused coping one. For low internalized stigma group (total stigma score ≤ 2), problem-focused coping strategy did not significantly affect the QOL, and most of the effects of perceived social support were direct (ß = 1.24; 99.2% of total effects). Internalized stigma was found to moderate the mediating effect of problem-focused coping on the relationship between perceived social support and QOL. Enhancing the problem-focused coping and social support may be helpful to improve QOL among PLHIV reporting high stigma.

Canine corneal epithelial cells possess a sustained proliferative capacity and generate a spontaneously derived cell line.

We have previously reported characteristics of canine corneal epithelial cells in vitro and found that canine corneal epithelial cells could maintain their proliferative capacity even after continuous culture without the use of feeder cells and growth promoting additives. The objective of this study was to elucidate proliferative characteristics of canine corneal epithelial cells independent of feeder cells and growth promoting additives, with the aim of developing a spontaneously derived corneal epithelial cell line. Canine and rabbit corneal epithelial cells were harvested from the limbus and cultured with, or without, feeder cells and growth promoting additives, and both were passaged continuously until growth arrest. Canine corneal epithelial cells could proliferate independently, and could be passaged more times than rabbit cells. A canine corneal epithelial cell line, cCEpi, which could be passaged more than 100 times without using feeder cells and growth promoting additives, was established. cCEpi cells maintained a cell morphology close to the primary culture and expressed p63, cytokeratin 15 (K15), and K3. Although changes in colony morphology, shortening of the population doubling time and a heteroploid karyotype were observed, cCEpi was not tumorigenic. Stratified cell sheets cultured from cCEpi were morphologically and immunohistologically similar to sheets cultivated from early passage cells. In conclusion, canine corneal epithelial cells can proliferate independent of feeder cells and growth promoting additives. cCEpi maintains properties similar to normal corneal epithelial cells and could be a useful source for studies in cellular biology and for developing novel therapies.

Effects of 1-cyclohexyl- and 1-cyclohexyl-N-propargyl-1,2,3,4-tetrahydroisoquinoline on dopaminergic spontaneous discharge in nigral neurons of rats.

1,2,3,4-Tetrahydroisoquinoline (TIQ) and some of its derivatives, such as 1-benzyl-TIQ and 1-methyl-TIQ, are endogenously present in human brain and are thought to contribute to induction or prevention of Parkinson's disease. In the present study, we estimated the effects of the artificially synthesized TIQ derivatives 1-cyclohexyl-TIQ (1-cHex-TIQ) and 1-cyclohexyl-N-propargyl-TIQ (1-cHex-N-proTIQ) on spontaneous nigral dopaminergic discharge in rats. Low to middle doses of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced a transient and significant, but not relatively potent, increase in the firing rate, followed by a sustained decrease with higher doses. 1-cHex-TIQ increased the firing frequency at low and high doses. In contrast, 1-cHex-N-proTIQ had no effects on spontaneous firing. Although intraperitoneal pretreatment with 1-cHex-TIQ did not inhibit this MPTP-induced decrease in firing, pretreatment with 1-cHex-N-proTIQ significantly depressed this decreased firing in a dose-dependent and long-lasting manner. Selegiline, a monoamine oxidase type B inhibitor that is used as a therapeutic drug for Parkinson's disease, also significantly inhibited the decrease in dopaminergic spontaneous firing induced by MPTP, but the effect was transient. These results suggest that although the decrease in firing induced by 1-cHex-TIQ is clearly more potent compared to that induced by MPTP, its effect is eliminated by adding an N-propargyl functional group. The antagonizing effect of 1-cHex-N-proTIQ on MPTP-induced firing loss may be exerted by a different mechanism than that of selegiline.