[Spatial Distribution and Influential Factors of Nutrients in Rivers of a Typical Mountainous City: A Case Study of the Qingshuixi River in Chongqing].

Surface water pollution seriously restricts the development of the city and results in the citizens yearning for a better life. Mountainous cities have their own characteristics in surface water environment and pollution compared with those of plain cities due to their unique topography. In August and October 2019, surface water and sediments were collected in a typical river (Qingshuixi River) in the main urban area of Chongqing. These samples were analyzed for nutrients such as carbon, nitrogen, and phosphorus as well as other basic physicochemical indicators. The results showed that the surface water of the Qingshuixi River was inferior to Category V at present, and it was also at a serious pollution level according to the comprehensive pollution index evaluation system. Among all the water quality indices, NH4+ and TP showed the most serious pollution. The tributaries of the Qingshuixi River exhibited higher surface water quality than that of the main stream, and the water quality during the rainfall season was better than that during the non-rainy season. Pollution sources, tailwater/tributary inflow, and river self-purification capacity determined the spatial distribution of nutrients in the surface water of the mainstream of the Qingshuixi River. Point sources such as the direct discharge of source sewage and pollution overflow in the middle and lower reaches were the most important sources of surface water pollution in the mainstream of the Qingshuixi River. Non-point source pollution had a limited impact on water quality. The "sink" or "source" role transformation of river sediments would occur under different water volume conditions in the river, reflecting the complexity of endogenous pollution. Surface water quality of the main stream showed a gradual improvement tendency along the downstream due to the dilution of the tail water/tributary inflow and the increased self-purification capability of the surface water in the mountainous rivers due to the increased DO content. To summarize, this study suggests that the water environment of the Qingshuixi River should be improved in comprehensive ways, which might be reducing the input of point source pollution by the deployment of the municipal pipe network in key areas, upgrading the sewage treatment plants to decrease pollutant concentrations or fluxes or channel dredging at the reaches with low DO content, etc.

Spontaneous resolution of idiopathic intestinal obstruction after pneumonia: A case report.

BACKGROUND: Duodenal obstruction is a common clinical scenario that can either be mechanical or a pseudo-obstruction. Clinical management of intestinal obstruction starts from localization and proceeds to histological examination of the stenotic intestine. Systemic factors and dysfunction of distant organs might contribute to the development of intestinal obstruction. Here, we report a unique case of idiopathic mechanical duodenal obstruction, which resolved spontaneously after 3 mo of conservative treatment, but was followed by intestinal pseudo-obstruction. CASE SUMMARY: An 84-year-old woman presented with worsened postprandial vomiting accompanied by prolonged pneumonia. Thorough noninvasive investigations revealed complete circumferential stenosis in the descending duodenum without known cause. Exploratory surgery was postponed due to septic shock and possible pulmonary fungal infection. Conservative treatment for 3 mo for ileus and control of pulmonary infection resolved the intestinal obstruction completely. Unfortunately, 2 wk later, she had regurgitation and postprandial vomiting again, complicated by deteriorating wheezing and dyspnea. Computed tomography revealed a dilated stomach and proximal duodenum without new intestinal stricture or pulmonary infiltration. The patient fully recovered after combined treatment with antireflux agents, enema, prokinetics, and bronchodilators. CONCLUSION: This complicated case highlights the inter-relationship of local and systemic contributions to ileus and gut dysfunction, which requires multidisciplinary treatment.

Role of 5-HT1A in the nucleus of the solitary tract in the regulation of swallowing activities evoked by electroacupuncture in anesthetized rats.

Somatic stimulation therapy, such as electroacupuncture (EA), has been widely applied in the clinic to treat dysphagia. However, its underlying mechanism has remained unknown. In the present study, the effect of EA at acupoints Fengfu (DU16) and Lianquan (RN23) on swallowing activities and the involvement of 5-HT1A in the nucleus of the solitary tract (NTS) were examined in anesthetized rats. EA at DU16 and RN23 significantly evoked myoelectric activity of the mylohyoid muscle, which was attenuated by injection of 10 nmol 5-HT1A antagonist (WAY-100635) into the NTS. Meanwhile, 5-HT1A expression in the NTS increased following EA. The results suggested that EA at DU16 and RN23 promotes swallowing activity, and 5-HT1A in the NTS may play an important role in the excitatory effects.