Distribution of interstitial cells of Cajal in the Esophagus and change in distribution after thoracic trauma.

Interstitial cells of Cajal (ICCs) function as pacemaker cells in the gastrointestinal tract. Acute thoracic trauma is a common and lethal cause of death due to physical trauma caused by traffic accidents. This study aimed to explore the distribution of esophageal ICCs and distribution changes observed after acute thoracic trauma. Thirty rabbits were randomly divided into a control group and two study groups. The control group animals underwent an esophagectomy. All animals in the study groups underwent right chest puncture using the Hopkinson bar technique. The study groups were subjected to esophagectomy 24 and 72 h after chest puncture. Distribution, morphology, and density of esophageal ICCs were detected using transmission electron microscopy, toluidine blue staining, and immunohistochemistry. Apoptosis of esophageal ICCs was evaluated using the terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling assay. Western blotting and reverse transcription polymerase chain reaction were used to detect changes in the SCF/c-kit signaling pathway. Esophageal ICCs distribution and SCF/c-kit signal pathway decreased from the upper part to the lower part in both physiological state and after thoracic trauma. In contrast, death of ICCs increased from the upper part to the lower part, both in physiological and injured state (P < 0.05). After thoracic trauma, increased ICCs and decreased death of ICCs in all parts of the esophagus (P < 0.05) were observed. The observed distribution and changes in esophageal ICCs would have an impact on motility and motility disorders of the esophagus.

The clinical journey and healthcare resources required for dialysis access of end-stage kidney disease patients during their first year of hemodialysis.

BACKGROUND: Creation and maintenance of dialysis vascular access (VA) is a major component of healthcare resource utilization and cost for patients newly started on hemodialysis (HD). Different VA format arises due to patient acceptance of anticipatory care versus late preparation, and clinical characteristics. This study reviews the clinical journey and resource utilization required for different VA formats in the first year of HD. METHOD: Data of patients newly commenced on HD between July 2015 and June 2016 were reviewed. Patients were grouped by their VA format: (A) pre-emptive surgically created VA (SCVA), (B) tunneled central venous catheter (CVC) followed by SCVA creation, (C) long-term tunneled CVC only. Clinical events, number of investigations and procedures, hospital admissions, and incurred costs of the three groups were compared. RESULTS: In the multivariable analysis, the cost incurred by the group A patients had no significant difference to that incurred in the group B patients (p = 0.08), while the cost of group C is significantly lower (p < 0.001). Both the 62.7% of group A with successful SCVA who avoided tunneled CVC usage, and those with a functionally matured SCVA in group B (66.1%), used fewer healthcare resources and incurred less cost for their access compared to those did not (p = 0.01, p = 0.02, respectively) during the first year of HD. CONCLUSION: With comparable cost, a pre-emptive approach enables avoidance of tunneled CVC. Tunneled CVC only access format incurred lower cost and is suitable for carefully selected patients. Successful maturation of SCVA greatly affects patients' clinical journey and healthcare cost.

[Distribution Characteristics and Migration Rules of Pollutants in Sediments of Reservoirs with Eucalyptus Plantation, Southern China].

The safety of water quantity and quality caused by large-scale blackwater in reservoirs with Eucalyptus plantation is currently a point of great interest. Eucalyptus is largely planted in southern China, especially in Nanning, Guangxi, where more than 90% of the drinking water source reservoirs are surrounded by Eucalyptus, and different degrees of blackwater often occur in many reservoirs. Recent research has demonstrated that reservoir sediments play an important role in the migration and transformation of Fe2+, Mn2+, S2-, and dissolved organic carbon (DOC) in the overlying water. It is of great significance to explore the distribution characteristics and migration rules of pollutants in the sediment-water interface to reveal the mechanism of blackwater in reservoirs. Experiments were carried out three times in a typical blackwater reservoir (Tianbao Reservoir) in southern China from July to December 2018. The distribution characteristics and seasonal variations of iron, manganese, sulfide, and organic matter in sediments were analyzed, focusing mainly on the profile distribution and migration direction of Fe2+, Mn2+, S2- and DOC in pore water during blackwater periods. The results showed that:① The content of iron and manganese in sediments of reservoirs with Eucalyptus plantation is high, far exceeding the background value of soil content in China. The content of iron, manganese, and total organic carbon (TOC) in the surface sediments increases simultaneously, mainly caused by the input and settlement of the material (litter, decomposed liquids. and soil particles) in the Eucalyptus forest around the reservoir. ② The concentration of Fe2+(16.99 mg·L-1) and the content of DOC (36.80%) in pore water during the blackwater period are significantly higher than those in Taihu Lake during the black bloom (12.15 mg·L-1, 10.78%). The mean concentrations of Fe2+ and Mn2+ are more than 300 times higher than that of S2-, and the reduction conditions in the sediments are dominated by iron and manganese oxides. ③ The diffusion flux of Fe2+ is 27.4-33.5 mg·(m2·d)-1, which is 32.6, 4.9, and 30.8 times higher than those of Taihu Lake, Aha Reservoir, and Hongfeng Lake, respectively. This implies strong Fe2+ release ability from sediments to the overlying water. As a positive correction exists between Fe2+ and DOC, the complex reaction between Fe2+ and organic matter is one of the most important causes of blackwater in reservoirs with Eucalyptus plantation.

[Uncertainty and Sensitivity Analysis of Phosphorus Model Parameters in Large Shallow Lakes].

Lake Taihu was chosen as a typical large shallow lake, and a diagenesis model of phosphorus was established based on environmental fluid dynamic code (EFDC). The uncertainty of the simulation results and the sensitivity of 16 parameters related to phosphorus migration and transformation in the diagenesis model were analyzed using Latin hypercube sampling (LHS), generalized likelihood uncertainty estimation (GLUE), and regionalized sensitivity analysis (RSA). The results showed that the temporal and spatial distribution of phosphate and total phosphorus in Lake Taihu was extremely uneven. Furthermore, the uncertainty of the diagenesis model had a strong influence on the simulation of phosphate and total phosphorus. For phosphate in the overlying, wind and wave disturbance at the 'sediment-water' interface was stronger in shallower water regions. The circulation of water in the bay area, where the dissolved oxygen content was low, was poor, which was conducive to the release of dissolved phosphorus in the sediment. For total phosphorus in the overlying water, the granular phosphorus and dissolved organic phosphorus contents in the central lake area were greatly affected by parameter uncertainties in the diagenesis model. The sensitive parameters mainly consisted of two kinds related to oxygen and dynamic characteristics, respectively. For large shallow lakes, the importance of parameter sensitivity in diagenesis models is no less than for hydrodynamic and water quality models. For large shallow lakes, the calibration of sensitive parameters should, therefore, be given attention when simulating the phosphorus content of areas with complicated water quality and sediment distributions.