Splenectomy versus Partial Splenic Embolization for Massive Splenomegaly Secondary to Hepatitis B-Related Liver Cirrhosis: A Case-Control Study

Background. Both splenectomy (SP) and partial splenic embolization (PSE) are used to treat massive splenomegaly (MSM) secondary to hepatitis B-related liver cirrhosis (HB-LC). This retrospective case-control study was conducted to compare the effects of SP and PSE on these patients. Methods. From July 2004 to January 2012, patients with MSM secondary to HB-LC who underwent SP or PSE were 1 : 1 : 1 matched with similar nonsurgery patients, respectively. Intraoperative situation, hematological indices, liver function, HBV DNA level, HBeAg seroconversion rate, morbidity, and mortality at 6 months postoperatively were compared. Results. Operative time, estimated blood loss, blood transfusion rate, severe pain, postoperative stay, and portal vein thrombosis (PVT) rate in the PSE group were significantly superior to the SP group, although SP and PSE were similar in liver function improvement, HBV suppression, morbidity, and mortality at 6 months postoperatively, and SP even improved WBC and PLT counts higher than PSE. Conclusion. Both SP and PSE are effective in improving liver function, increasing WBC and PLT counts, and suppressing replication of HBV for MSM secondary to HB-LC. Although postoperative improvement in WBC and PLT counts by SP can be higher than PSE, PSE is simple and minimally invasive and has a lower incidence of PVT

Risk Assessment and Control for Geohazards at Multiple Scales: An Insight from the West Han River of Gansu Province in China

Risk assessment provides a powerful tool for the early warning and risk mitigation of geohazards. However, few efforts have been made regarding risk assessment and dynamic control at multiple scales. With respect to this issue, the West Han River catchment in the Gansu Province of China was taken as a study area, and geohazard risk assessments at three different scales were carried out, namely regional, local and site scales. Hazard assessment was performed using the combination of the information value and hierarchical analysis models, infinite slope stability model, and FLO-2D model. Vulnerability was estimated from two viewpoints, including physical vulnerability and social vulnerability, by applying remote sensing and semi-quantitative methods. Finally, risk mapping and zonation was obtained from the products of hazard and vulnerability, and corresponding measures of risk management and control at different scales were recommended. The results indicated that the geohazard risk at the regional scale was the highest under the earthquake and rainfall conditions with a 100-year (100a) return period, respectively, and the area of very high risk level reached 5%. When the rainfall condition had a return period of 50 years, only 1% of the area was located in the very high-risk region. Additionally, the overall risk was higher in the central and northeastern parts of the region under heavy rainfall and earthquake conditions. The overall risk level in Longlin-Leiba Town (at the local scale) responded more significantly to heavy rainfall conditions, with higher risk in the southwestern, central, and northeastern parts of the region. For the site scale (Wujiagou debris flow), only 2% of the total area was identified as very high-risk even under heavy rainfall with a 100a return period, but the proportions for the low and moderate levels reached 30% and 56%, respectively. The present study can provide scientific references for geohazard risk assessment and control

Interface Effect on the Electropolymerized Polypyrrole Films with Hollow Micro/Nanohorn Arrays

Polypyrrole (PPy) films with hollow micro/nanohorn arrays were controllably synthesized in p-toluenesulfonate aqueous solutions by template-free electrochemical methods. The micelles which consist of pyrrole monomers and the surfactants provided the soft templates during the polymerization process. The polymerization potential and pH value of the solutions cooperatively influenced the shape of the micelles at the substrate/electrolyte interface and further controlled the morphologies of PPy films. PPy grew along the soft templates during the high potential periods of a pulse potentiostatic (PPS) method, while the pH value and the low potential were varied to modulate the shape of the soft templates. It has been shown to be most appropriate to fabricate hollow micro/nanohorn PPy films with the highest electrical conductivity (190 S cm^–1) via PPS at pH ∼1.5. A diagram was also introduced in order to illustrate the polymerization potential and pH value dependence of nanohorn PPy morphologies. This work proposed a potential method to the in situ growth of conducting polymers with high conductivity and high specific surface area

Risk Assessment and Control of Geological Hazards in Towns of Complex Mountainous Areas Based on Remote Sensing and Geological Survey

Mountainous areas have become among the most developed areas of geological hazards due to special geological environmental conditions and intensive human engineering activities. Geological hazards are a main threat to urbanization, rural revitalization, and new rural construction in complex mountainous areas. It is of great strategic significance to conduct large-scale geological hazard investigation and risk assessment in urban areas, control the risk of geological hazards at the source and propose risk control measures. In this paper, we established the technical methods of geologic hazard risk assessment and control in complex mountain towns by taking Longlin Town in the mountainous region of Gansu Longnan, China as the study area, with the Quanjia bay debris flows and Panping Village landslides as the typical pilot investigation and assessment. The methods consist of six stages—risk identification, hazard disaster model investigation, risk analysis, vulnerability assessment, risk evaluation and risk management and control measures and proposals. On this basis, the results of geological hazards with different precipitation frequencies (5%, 2%, 1%) are presented. The results show that 75.23% of the regions remained at low risk levels; 24.38% of the regions increased a risk level with decreasing precipitation frequency, and 0.39% of the regions remained at extremely high risk levels under different precipitation frequency conditions. For the Quanjia bay debris flows and Panping Village landslides case, we discussed the geological hazards risk source control contents, management and control technologies, engineering and non-engineering measures of disaster prevention and control for urban disasters and specific disaster areas. This research can provide technical support and reference for disaster prevention and mitigation, and territorial spatial planning