[Source and Cause Analysis of High Concentration of Inorganic Aerosol During Two Typical Pollution Processes in Winter over Tianjin].

Inorganic aerosol is the main component of haze days in winter over Tianjin. In this study, two typical high concentrations of secondary inorganic aerosol (SIA) processes, defined as CASE1 and CASE2, were selected during polluted days in January 2020 over Tianjin, and the effects of meteorological factors, regional transport, and chemical processes were comprehensively investigated combined with observations and numerical models (WRF-NAQPMS). The average SIA concentrations in CASE1 and CASE2 were 76.8 µg·m-3 and 66.0 µg·m-3, respectively, and the nitrate concentration was higher than that of sulfate and ammonium, which were typical nitrate-dominated pollution processes. Meteorological conditions played a role in inorganic aerosol formation. The temperature of approximately -6-0℃ and 2-4℃ and the relative humidity of 50%-60% and 80%-100% would be suitable conditions for the high SIA concentration (>80 µg·m-3) in CASE1, whereas the temperature of approximately 2-4℃ and the relative humidity of 60%-70% would be suitable in CASE2. The average contribution rates of external sources to SIA in the CASE1 and CASE2 processes were 62.3% and 22.1%, which were regional transport-dominant processes and local emission-dominant processes, respectively. The contribution of the local emission of CASE1 to nitrate and sulfate was 16.2 µg·m-3 and 8.2 µg·m-3, respectively, higher than that of external sources (31.7 µg·m-3 and 8.8 µg·m-3). the local contribution of CASE2 to nitrate and sulfate was 29.3 µg·m-3 and 25.1 µg·m-3, respectively, whereas the contribution from external sources was 8.1 µg·m-3 and 9.4 µg·m-3, respectively. The quantitative result indicated that local formation and regional transport resulted in higher nitrate concentration than sulfate in CASE1, in contrast to only local sources in CASE2. The gas phase reaction was the main source of inorganic aerosol formation, contributing 48.9% and 57.8% in CASE1 and CASE2, respectively, whereas the heterogeneous reactions were also important processes, with contribution rates of 48.1% and 42.2% to SIA. The effect of aqueous phase reaction was negligible.

[Spatial Distribution Characteristics of VOCs and Its Impact on Ozone Formation Potential in Rizhao City in Summer].

GC-SAW was used to carry out online sampling analysis of the main business sources, residential sources, and roads in Rizhao City from August 22 to 29 in 2020. The spatial distribution characteristics of various volatile organic compounds (VOCs) in the atmosphere were obtained, and the chemical reactivity of the main components was studied. The results showed that the VOCs with carbon atoms greater than 5 (VOCC>5) were mainly toluene propylbenzene and n-octane, and the spatial distribution was significant; the average ρ(TVOCC>5) in the port area, downtown area, and industrial area were 80.5, 115.3, and 118.1 µg·m-3, respectively. Combined with road traffic impact and industrial production emissions, the maximum ρ(TVOCC>5) on the main roads in Rizhao City appeared near the Yingbin Road; the concentration value was 164.37 µg·m-3; the ρ(BTEX) in adhesive processing, painting, and glass factories reached 432.34, 1010.84, and 1989.85 µg·m-3, respectively. The chemical reactivity analysis of the main components of VOCC>5 showed that BTEX and n-octane were the important active components of ozone formation in Rizhao City.

Pediatric liver transplantation in 31 consecutive children.

BACKGROUND: Although liver transplantation has become a standard therapy for end-stage liver diseases, the experience of pediatric liver transplantation is limited in China. In this article we report our experience in pediatric liver transplantation, and summarize its characters in their indications, surgical techniques, and postoperative managements. METHODS: Thirty-one children (< or = 18 years old) underwent liver transplantation in our centers. The mean age at transplantation was 12.4 years old (ranged from 5 months to 18 years) with 7 children being less than 4 years of age at transplantation. The most common diagnosis of patients who underwent liver transplantation were biliary atresia, Wilson's disease, primary biliary cirrhosis, glycogen storage disease, hepatoblastoma, urea cycle defects, fulminant hepatic failure, etc. The surgical procedures included 12 standard (without venovenous bypass), 6 pigyback, 6 reduced-size, 3 split, 3 living donor liver transplantation, and 1 Domino liver transplantation. The triple-drug (FK506, steroid, and mycophenolate mofetil) immunosuppressive regimen was used in most of patients. Patients were followed up for a mean of 21.8 months. RESULTS: Five of the 31 patients died during perioperative time; mortality rate was 16.1%. The reasons of death were infections, primary non-function, heart failure, and hypovolemic shock. Postoperative complications in 10 patients included biliary leakage, acute rejection, abdominal infection, hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, and pulmonary infection. Overall patient cumulative survival rate at 1-, 3-, and 5-year was 78.1%, 62.6%, 62.6%, respectively. CONCLUSIONS: The most common indications of pediatric liver transplantation were congenital end-stage liver diseases. According to patients' age and body weight, standard, piggyback, reduced-size, split, or living donor liver transplantation should be performed. Pediatric liver transplantation especially requires higher surgical skills. The early postoperative management is the key to success. Postoperative bile leak was common, but most patients underwent liver transplantation had a better prognosis.

[Pediatric liver transplantation in 20 consecutive children].

OBJECTIVE: To summarize the clinical efficacy of pediatric liver transplantation, and investigate the characters of pediatric liver transplantation in their indications, surgical procedures and postoperative management. METHODS: From August 2000 to March 2007, 23 liver transplantations were performed on 20 children, aging from 6 months to 13 years old. The most common indications were biliary atresia, Wilson's disease, glycogen storage disease and urea cycle defects. Surgical procedures included 4 living donor liver transplantations, 1 Domino liver transplantation, 5 split grafts, 10 reduced liver grafts and 3 whole cadaveric grafts. The triple-drug (FK506, steroid and MMF) immunosuppressive regimen was used in 19 children, except one children using cyclosporine. RESULTS: Three children died of primary non-function, heart failure and abdominal infections respectively during peri-operative period, and the mortality was 15.0%. Nine children showed different post-operative complications including 2 hepatic artery thrombosis, 1 portal vein thrombosis, 1 acute rejection, 3 biliary leakage, 2 biliary stricture, 2 intestinal fistula, 3 abdominal infection, 1 pulmonary infection and 1 heart failure. Cumulative patient survival rates at 6-month, 1-and 2-year were 80.0%, 73.9% and 73.9%, respectively. CONCLUSIONS: Liver transplantation is an effective option to cure the liver disease of children with end-stage. Different surgical procedure could be chosen according to the children's age and body weight.

[Observational Study of Air Pollution Complex in Nanjing in June 2014].

Studying the evolution of secondary inorganic aerosols, which are important components of PM2.5, is crucial to improving our understanding about the air pollution in big cities. This study investigates the evolution and factors of secondary inorganic aerosols based on two pollution incidences in Nanjing in June 2014. A significant characteristic of air pollution complex with the coexistence of higher concentrations of both PM2.5 and ozone is observed. In the earlier stage of the pollution episode, ozone concentrations were high, which could exceed 250, triggering a stronger oxidation in the atmosphere and a higher production potential of nitric acid that leads to the quick production of nitrate. In the later period of the pollution episode, relative humidity played an essential role. An increase in relative humidity would result in a sharp decrease in the theoretical product of the partial pressures of NH3 and HNO3, especially when relative humidity exceeds the mutual deliquesce relative humidity that makes it easier to form nitrate. The difference in the theoretical and observational partial pressure product could characterize the evolution of nitrate perfectly.

Pathogenesis of acute lung injury in rats with severe acute pancreatitis.

BACKGROUND: Acute lung injury (ALI) is the most common and severe complication of severe acute pancreatitis (SAP). The elucidation of the mechanism of ALI contributes to the diagnosis and treatment of the illness. In this study, we studied the pathogenesis of ALI in rats with severe acute pancreatitis. METHODS: The rats were sacrificed at 1, 3, 5, 6, 9 and 12 hours after the establishment of the model of SAP. Pancreas and lung tissues were obtained for pathological study, and examination of microvascular permeability and myeloperoxidase (MPO) examination. The gene expressions of tumor necrosis factor-alpha (TNF-alpha) and intercellular adhesion molecule-1 (ICAM-1) in the pancreas and lung tissues were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: After the establishment of the SAP model, the degree of pancreatic and lung injury increased gradually along with the gradual increase of MPO activity and microvascular permeability. Gene expressions of TNF-alpha and ICAM-1 in the pancreas rose at 1 hour and peaked at 7 hours. In contrast, their gene expression in the lungs rose slightly at 1 hour and peaked at 9-12 hours. CONCLUSION: An obvious time window existed between SAP and lung injury, which is beneficial to the early prevention of the development of ALI.

Advances in prophylaxis and treatment of recurrent hepatitis B after liver transplantation.

BACKGROUND: In the 1990s, liver transplantation for hepatitis B virus (HBV) related-liver diseases was a very controversial issue because the graft was inevitably recurrent after liver transplantation. Significant progress has been made in the prophylaxis and treatment of recurrent hepatitis B after liver transplantation. This review covers the mechanisms, prophylaxis, and treatment of hepatitis B recurrent after liver transplantation. DATA SOURCES: Searching MEDLINE (1995-2004) for articles on liver transplantation. RESULTS: HBV reinfection after liver transplantation results from HBV particles in circulation or other extrahepatic sites. Hepatitis B immune globulin (HBIG) was effective in reducing HBV reinfection and improving graft survival after liver transplantation. Lamivudine has also dramatically reduced the recurrence of HBV in the patient undergoing liver transplantation. CONCLUSIONS: Combination HBIG and lamivudine is the most effective porphylatic regimen. Lamivudine and adefovir are highly effective in treatment of HBV recurrence. HBV-related liver disease is no longer a contraindication for liver transplantation.

Dexamethasone and dextran 40 treatment of 32 patients with severe acute pancreatitis.

AIM: Based on the pathogenesis of severe acute pancreatitis and our experimental studies, to investigate the effect of dexamethasone and dextran in treatment of patients with severe acute pancreatitis. METHODS: Thirty-two patients with severe acute pancreatitis were treated with 0.5-1 mg/kg per day dexamethasone for 3-5 d, and 500-1,000 mL/d of dextran 40 for 7 d, besides the routine therapy. RESULTS: After 4-8 h of treatment, abdominal pain began to be relieved; range of tenderness began to be localized in 27 patients. They were cured with nonsurgical treatment. Five of them were deteriorated, and treated with surgery. Four patients in this group died. CONCLUSION: Dexamethasone and dextran 40 block the pathologic process of severe acute pancreatitis through inhibition of inflammatory mediators and improvement of microcirculation disorders respectively.

Liver retransplantation: indications and outcomes.

BACKGROUND: Liver transplantation is a life-saving therapeutic modality for patients with end-stage liver diseases. After liver transplantation, however, more than 10% patients may lose the grafts caused by a variety of reasons. This review covers the most frequent indications for liver retransplantation as well as the results and specific problems with each indication. DATA RESOURCES: Searching MEDLINE (1997-2003) for articles on liver retransplantation. RESULTS: The most frequent indications of liver retransplantation are primary non-function, hepatic artery thrombosis, graft rejection and recurrent diseases. The results after liver retransplantation remain inferior to those after first transplantation. CONCLUSION: Liver retransplantation, which is the only means of prolonging survival in those patients whose initial graft has failed, makes an important contribution to overall survival.

Bioartificial liver assist devices in support of patients with liver failure.

Bioartificial liver assist devices (BALs) offer an opportunity for critical care physicians and transplant surgeons to stabilize patients prior to orthotopic liver transplantation. Such devices may also act as a bridge to transplant, providing liver support to patients awaiting transplant, or as support for patients post living-related donor transplant. Four BAL devices that rely on hepatocytes cultured in hollow fiber membrane cartridges (Circe Biomedical HepatAssist(r), Vitagen ELADTM, Gerlach BELS, and Excorp Medical BLSS) are currently in various stages of clinical evaluation. Comparison of the four devices shows that several unique approaches based upon the same overall system architecture are possible. Preliminary results of the Excorp Medical BLSS Phase I safety evaluation at the University of Pittsburgh, after treating four patients (F, 41, acetominophen-induced, two support periods; M, 50, Wilson's disease, one support period; F, 53, acute alcoholic hepatitis, two support periods; F, 24, chemotherapy-induced, one support period, are presented. All patients presented with hypoglycemia and transient hypotension at the start of extracorporeal perfusion. Hypoglycemia was treated by IV dextrose and the transient hypotension responded positively to IV fluid bolus. Heparin anticoagulation was used only in the second patient. No serious or adverse events were noted in the four patients. Moderate Biochemical response to support was noted in all patients. More complete characterization of the safety of the BLSS requires completion of the Phase I safety evaluation.

The role of inflammatory mediators in severe acute pancreatitis and regulation of glucocorticoids.

OBJECTIVE: To investigate the effect of glucocorticoids on systemic inflammatory mediator release in rats with acute pancreatitis and the outcome of dexamethasone in treatment of acute pancreatitis. METHODS: Sixty-eight Wistar rats were divided into sham, acute pancreatitis, and treatment (intravenous dexamethasone 0.5 mg/kg) groups. Experimental acute pancreatitis was induced by the injection of 5% sodium taurocholate (0.1 ml/100 mg body weight) into the pancreatic-biliary duct. The blood samples were obtained and examined for 6-keto-PGI1alpha, TXB2 and IL-6 postoperatively at 3, 6 and 12 hours, respectively. The pancreatic samples were evaluated by a blinded method. Twelve-hour survival rate was determined and compared between the groups. RESULTS: The high serum concentrations of 6-keto-PGI1alpha, TXB2 and IL-6 were noted in the rats with acute pancreatitis associated with pancreatic hemorrhage and necrosis. Their 12-hour survival rate was 42.9%. The rats in the treatment group survived with significantly reduced serum concentrations of 6-keto-PGI1alpha, TXB2 and IL-6 (P<0.05). Their pancreatic morphology was normal. CONCLUSION: Dexamethasone may reduce the serum concentration of 6-keto-PGI1alpha, TXB2, and IL-6, and the severity of acute pancreatitis while increasing the survival rate of rats with acute pancreatitis.

[Spatiotemporal trends and the impact factors of acid rain in Anhui Province].

The observational data of acid rain at seven stations in Anhui province operated by China Meteorological Administration (CMA), as well as the coal consumptions in Anhui and some surrounding provinces along with satellite measured tropospheric NO2 columns, were used to analyze the spatiotemporal trends of acid rain in Anhui and the potential reasons of the increasing occurrence frequency of acid rain. In addition, the technique of back-trajectory-cluster analysis was used to examine the impacts of transport patterns on the precipitation acidity in Anhui. The occurrence frequency shows the lowest in summer and the highest in autumn, with 3-year average pH < 5.6 during 2006-2008 at all stations, hereinto, pH values are between 5.0 and 4.5 in Hefei, Anqing, Maanshan and Bengbu. In spatial, acid rain were the most severe in southern to middle Anhui and mitigated to north. The distributions of pH were concentrative at Fuyang, Tongling and Huangshan, with more than 75% occurred between 6.00-7.50 (Fuyang), 5.00-6.00 (Tongling) and 5.00-6.50 (Huangshan); quite dispersive at other stations, with the maximum at 4.00-4.50 (Hefei and Anqing), 5.00-5.50 (Maanshan) and 5.50-6.00 (Bengbu). The occurrence frequencies of acid rain increased evidently at all stations comparing with those in the end of 1990s. The results of back-trajectories-cluster analysis show that the acid rain is closely related with the regional-range transport of acid rain precursors at each station. The air-masses from southeast and northeast, especially those passing through Jiangsu and Zhejiang, associated with the highest frequencies of acid rain with pH < 5.0, indicating that the industrial emissions in the economy developed areas of Yangtze Delta play key roles in acid rain in Anhui province. In addition, statistics shows that the occurrence frequency of acid rain in Hefei was highly correlated with the trends of the provincial coal consumptions in Anhui, Jiangsu and Zhejiang, also tropospheric NO2 column content over Anhui province and surrounding areas with all correlation coefficients > 0.7, suggesting the close relationship between the quick increasing acid rain in Hefei and the regional pollutant emissions.