Abstract:The urbanized world has brought social, economic, and environmental sustainability into challenged surroundings in rapidly rising countries, thereby requiring the exploration of their intertwined relationships. This study regarded Brazil, India, and China as "BIC" countries to be the representative study areas for our investigation of sustainability in the context of rapid urbanization. In general, our work was synthesized into a comparison framework in four aspects: rural-urban relation, industrial development, city development, and urban landscape pattern. We determined that rural-urban dichotomy exists in all study areas, with India and China having a high degree. China was identified as a manufacturing-based country in the past half-century, whereas Brazil and India have the service sector as their primary industry. The distribution of large cities follows a regional pattern, with Brazil being northeast-focused, China being southeast-focused, and India being comparatively balanced. The Amazon forest in the north brings great challenges to Brazil with respect to the conservation of its biodiversity and eco-environment. India and China have encountered tremendous urban expansion or sprawl in the past several decades. The sustainability issues in social, economic, and environmental aspects for Brazil, India, and China were summarized in the context of rapid urbanization to provide references for other countries.

PurposeThe aims of this study were to investigate the effect of hyperbaric oxygen (HBO) treatment at various stages following chronic constriction injury (CCI) and to explore the underlying mechanisms of HBO treatment.MethodsForty adult male Sprague—Dawley rats were randomly assigned to five groups (n = 8 for each group): the sham group, CCI group, HBO1 group, HBO2 group, and HBO3 group. Neuropathic pain was induced by CCI of the sciatic nerve. HBO treatment began on postoperative days 1, 6, and 11 and continued for 5 days. The mechanical withdrawal threshold and thermal withdrawal latency were tested on preoperative day 3 and postoperative days 1, 3, 5, 7, 10, 14, and 21. The expression of P2X4R was determined by immunohistochemistry and western blot analysis. Cell apoptosis was measured using TUNEL staining. The expression of caspase 3 was measured using reverse transcription polymerase chain reaction (RT-PCR). Electron microscopy was used to determine the ultrastructural changes.ResultsEarly HBO treatment beginning on postoperative day 1 produced a persistent antinociceptive effect and inhibited the CCI-induced increase in the expression of P2X4R without changing CCI-induced apoptosis. In contrast, late HBO treatment beginning on postoperative day 11 produced a persistent antinociceptive effect and inhibited CCI-induced apoptosis and upregulation of caspase-3 without changing the expression of P2X4R. In addition, late HBO treatment reduced CCI-induced ultrastructural damage. However, HBO treatment beginning on postoperative day 6 produced a transient antinociceptive effect without changing the expression of P2X4R or CCI-induced apoptosis.ConclusionHBO treatment at various stages following CCI can produce antinociceptive effects via different mechanisms. Early HBO treatment is associated with inhibition of P2X4R expression, and late HBO treatment is associated with inhibition of cell apoptosis.

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