Rare portal hypertension caused by Abernethy malformation (Type IIC): A case report.

BACKGROUND: Abernethy malformation is a rare congenital vascular malformation with a portosystemic shunt that may clinically manifest as cholestasis, dyspnea, or hepatic encephalopathy, among other conditions. Early diagnosis and classification are very important to further guide treatment. Typically, patients with congenital portosystemic shunts have no characteristics of portal hypertension. Herein, we report an 18-year-old female with prominent portal hypertension that manifested mainly as rupture and bleeding of esophageal varices. Imaging showed a thin main portal vein, no portal vein branches in the liver, and bleeding of the esophageal and gastric varices caused by the collateral circulation upwards from the proximal main portal vein. Patients with Abernethy malformation type I are usually treated with liver transplantation, and patients with type II are treated with shunt occlusion, surgery, or transcatheter coiling. Our patient was treated with endoscopic surgery combined with drug therapy and had no portal hypertension and good hepatic function for 24 mo of follow-up. CASE SUMMARY: This case report describes our experience in the diagnosis and treatment of an 18-year-old female with Abernethy malformation type IIC and portal hypertension. This condition was initially diagnosed as cirrhosis combined with portal hypertension. The patient was ultimately diagnosed using liver histology and subsequent imaging, and the treatment was highly effective. To publish this case report, written informed consent was obtained from the patient, including the attached imaging data. CONCLUSION: Abernethy malformation type IIC may develop portal hypertension, and traditional nonselective beta-blockers combined with endoscopic treatment can achieve high efficacy.

Prevention and treatment of hepatic encephalopathy during the perioperative period of transjugular intrahepatic portosystemic shunt.

Transjugular intrahepatic portosystemic shunt (TIPS) is an established procedure for treating the complications of portal hypertension in liver cirrhosis. While the pathogenesis of postoperative TIPS-related hepatic encephalopathy (HE) has yet to be fully understood, intraoperative portosystemic shunts may provide a pathological basis for the occurrence of postoperative HE in patients with liver cirrhosis. Studies at home and abroad have expressed mixed opinions about TIPS-related HE. This study presents a literature review on the risk factors for and prevention and treatment of perioperative TIPS-related HE in patients with liver cirrhosis, aiming to optimize the procedure and reduce the incidence of postoperative HE.

[Characteristics and Source Apportionment of Atmospheric Ion Deposition During Winter and Spring in the Core Area of Beijing].

In recent years, the Ministry of Ecology and Environment and the Beijing Municipal Government have continuously strengthened the control indicators of dustfall. In order to grasp the characteristics and sources of ion deposition in dustfall, the filtration method and ion chromatography were used to determine the dustfall and ion deposition during winter and spring in the core area of Beijing, and the PMF model was carried out to analyze the sources of ion deposition. The results indicated:① the average values of ion deposition and its proportion in dustfall were 0.87 t·(km2·30 d)-1 and 14.2%, respectively. The dustfall and ion deposition on working days were 1.3 times and 0.7 times that on rest days, respectively. ② The coefficient of determination in the linear equations between ion deposition and precipitation, relative humidity, temperature, and average wind speed were 0.54, 0.16, 0.15, and 0.02, respectively. In addition, the coefficient of determination in the linear equations between ion deposition and PM2.5 concentration and dustfall were 0.26 and 0.17, respectively. Therefore, controlling the concentration of PM2.5 was crucial to treating ion deposition. ③ Anions and cations accounted for 61.6% and 38.4%, respectively, in the ion deposition, and SO42-, NO3-, and NH4+ accounted for 60.6% in total. The ratio of anion and cation charge deposition was 0.70, and the dustfall was alkaline. The ρ(NO3-)/ρ(SO42-) in the ion deposition was 0.66, which was higher than that of 15 years ago. ④ The contribution rates of secondary sources, fugitive dust sources, combustion sources, snow-melting agent sources, and other sources were 51.7%, 17.7%, 13.5%, 13.5%, and 3.6%, respectively.

Influence of different portal vein branches on hepatic encephalopathy during intrahepatic portal shunt via jugular vein.

This letter is regarding the study titled 'Targeted puncture of left branch of intrahepatic portal vein in transjugular intrahepatic portosystemic shunt (TIPS) to reduce hepatic encephalopathy'. Prior to the approval of TIPS dedicated stents (Viatorr stents) in China in October 2015, Fluency covered stents were typically used. As Fluency covered stents have a strong support force and axial elastic tension, a 'cap' may form if the stent is located too low at the end of the hepatic vein or too short at the end of the portal vein during surgery, leading to stent dysfunction. Since the blood shunted by the stent is from the main trunk of the portal vein, the correlation between the incidence of postoperative hepatic encephalopathy and the location of the puncture target (left or right portal vein branch) is worth discussion. Notably, no studies in China or foreign countries have proven the occurrence of left and right blood stratification after the accumulation of splenic vein and mesenteric blood flow in the main trunk of the portal vein in patients with cirrhotic portal hypertension.

Temporary pacemaker protected transjugular intrahepatic portosystemic shunt in a patient with acute variceal bleeding and bradyarrhythmia: A case report.

BACKGROUND: Esophagogastric varices are a common complication of cirrhosis with portal hypertension and endoscopic treatment has been recognized as a primary preventive and therapeutic option for such patients; however, it should be noted that bradyarrhythmia is regarded as one of the contraindications to endoscopic examination. Meanwhile, acute variceal bleeding may result in a high mortality rate in cirrhotic patients with portal hypertension accompanied by bradyarrhythmia. At present, there is an absence of reports concerning the treatment of such group of patients who underwent transjugular intrahepatic portosystemic shunt (TIPS). The present report details the case of a cirrhotic patient with acute variceal bleeding accompanied by bradyarrhythmia who underwent TIPS under temporary pacemaker protection. CASE SUMMARY: We report the case of a 64-year-old male patient who was confirmed with bradyarrhythmia by ambulatory electrocardiogram 24 h before the operation. The patient was successfully treated by TIPS under temporary pacemaker protection. CONCLUSION: In terms of cirrhotic patients with abnormal cardiac electrophysiological conduction, TIPS may be effective in reducing the complications of portal hypertension following the exclusion of severe pulmonary hypertension and heart failure, showing moderate feasibility in clinical applications.

Clinical efficacy of antiviral therapy in patients with hepatitis B-related cirrhosis after transjugular intrahepatic portosystemic shunt.

BACKGROUND: As a country with a high burden of hepatitis B, China has about 86 million cases of hepatitis B virus infection, ranking the first in the world. Currently, there are about 390000 deaths due to hepatitis B-related complications such as liver cirrhosis and liver cancer every year. Consequently, how to control portal hypertension, improve liver functional reserve, and reduce the incidence of hepatic failure and liver cancer in such patients is the focus of current clinical attention. Previous clinical study in our center suggested that at 24 mo after transjugular intrahepatic portosystemic shunt (TIPS), the liver functional reserve of patients with hepatitis B cirrhosis was better than that of patients with alcohol-induced and immune cirrhosis, which may be related to the effective etiological treatment. AIM: To investigate the clinical efficacy of three first-line antiviral drugs recommended by the guidelines of prevention and treatment for chronic hepatitis B in China (2019) in the treatment of patients with hepatitis B-related cirrhosis who had received a TIPS. METHODS: The clinical data of 137 patients with hepatitis B-related cirrhosis with portal hypertension after receiving TIPS at our centre between March 2016 and December 2020 were analysed retrospectively. According to different anti-viral drugs, the patients were divided into entecavir (ETV) (n = 70), tenofovir alafenamide fumarate (TAF) (n = 32), and tenofovir disoproxil fumarate (TDF) (n = 35) groups. The cumulative incidence of hepatic encephalopathy and hepatocellular carcinoma, survival, and changes in hepatic reserve function and glomerular filtration rate in patients treated with different antiviral drugs within 24 mo after surgery were investigated. RESULTS: At 24 mo after surgery, the Child-Pugh score in the TAF group (6.97 ± 0.86) was lower than that in the TDF (7.49 ± 0.82; t = -2.52, P = 0.014) and ETV groups (7.64 ± 1.17; t = -2.92, P = 0.004). The model for end-stage liver disease score in the TAF group at 24 mo after surgery was 9.72 ± 1.5, which was lower than that in the TDF (10.74 ± 2.33; t = -2.09, P = 0.040) and ETV groups (10.97 ± 2.17; t = -2.93, P = 0.004). At 24 mo after surgery, the estimated glomerular filtration rate (eGFR) in the TAF group (104.41 ± 12.54) was higher than that in the TDF (93.54 ± 8.97) and ETV groups (89.96 ± 9.86) (F = 21.57, P < 0.001). CONCLUSION: At 24 mo after surgery, compared with TDF and ETV, TAF has significant advantages in the improvement of liver functional reserve and eGFR.

Effects of transjugular intrahepatic portosystemic shunt using the Viatorr stent on hepatic reserve function in patients with cirrhosis.

BACKGROUND: As transjugular intrahepatic portosystemic shunt (TIPS) creation alters the hemodynamic status of the portal system, whether reduced portal blood supply affects the synthetic reserve function of the liver has been the focus of clinical attention. Since the Viatorr stent entered the Chinese market in 2015, it has not yet been widely used in clinical practice. Further, unlike other countries, the main cause of liver cirrhosis in China is viral hepatitis. Therefore, use of the Viatorr stent to establish a TIPS channel in patients with liver cirrhosis with differing etiologies is of great clinical interest. AIM: To investigate factors affecting changes in liver reserve function after TIPS Viatorr stent implantation. METHODS: Clinical data from 200 patients with cirrhotic portal hypertension who received TIPS treatment from March 2016 to March 2020 were analyzed retrospectively. The patients were divided into three groups (A-C), according to their disease etiology, with post-hepatitis, autoimmune, and alcoholic cirrhosis, respectively. Preoperative and postoperative liver and renal function and coagulation data, Child-Pugh grade, and model for end-stage liver disease (MELD) scores were collected. Statistical analyses were performed using the t-test or chi-square test. The incidence and of hepatic encephalopathy and patient survival were calculated using Kaplan-Meier method. RESULTS: The surgical success rate was 100%, with mean portal pressure gradient (mmHg) decreasing from 25.5 ± 5.22 to 10.04 ± 2.76 (t = 45.80; P < 0.001). After 24 mo, the cumulative incidence of hepatic encephalopathy in group A was significantly lower than that in group B/C, while the cumulative survival rate was significantly higher in group A than in group B/C (P < 0.05 for both). The Child-Pugh score for group A was 6.96 ± 1.21, which was significantly better than those of groups B (7.42 ± 0.99; t = -2.44; P = 0.016) and C (7.52 ± 1.12; t = -2.67; P = 0.009). Further, the MELD score for group A (9.62 ± 2.19) was significantly better than those for groups B (10.64 ± 1.90; t = -2.92; P = 0.004) and C (10.82 ± 2.01; t = -3.29; P = 0.001). CONCLUSION: Insertion of 8 mm internal diameter Viatorr stent has no significant effects on liver reserve function. Changes of liver reserve function in the medium and long term may be related to the etiology and treatment of portal hypertension.

Characterization of Neoschoengastia gallinarum from subtropical China by rDNA and identification of two genotypes based on mitochondrial cox1.

Genetic variations in the 18S ribosomal DNA (18S), 28S ribosomal DNA (28S), second internal transcribed spacer of ribosomal DNA (ITS2), and mitochondrial cytochrome c oxidase subunit 1 (cox1) of Neoschoengastia gallinarum collected from subtropical China were examined. First, a portion of the 18S (p18S), a portion of the 28S (p28S), and the complete ITS2 were separately amplified from individual mites and sequenced. The lengths of the sequences of p18S, p28S, and ITS2 were found to be 1379 bp, 3465~3468 bp, and 200 bp, respectively. The intraspecific sequence variation was 0~0.1% for p28S and 0~1.6% for ITS2, though no variation was observed for p18S, suggesting conservation of rDNA sequences. Second, a portion of the mitochondrial cox1 gene (pcox1) of N. gallinarum was analyzed. The length of the pcox1 sequence is 460 bp, and two distinct groups were observed in N. gallinarum. All pcox1 sequences in group I were identical, and there was only one nucleotide transition observed in group II; however, 7.0~7.2% variations between the two groups were observed, suggesting that two genotypes of N. gallinarum: genotype I and genotype II. Phylogenetic analyses based on pcox1 sequences indicated that N. gallinarum isolates (genotype I or genotype II) clustered into one branch; according to cox1 sequence analysis of Trombiculidae, Walchia hayashii is the closest species. The present study shows that ITS2 rDNA sequence can act as marker for the identification of N. gallinarum samples. Furthermore, analysis of the mitochondrial pcox1 sequence suggests the existence of two genotypes, which has implications for further studies of the ecology and population genetic structures of N. gallinarum.

[Localization of Soil Wind Erosion Dust Emission Factor in Beijing].

Soil wind erosion dust is one of the primary sources of fine particulate matter (PM2.5). Compared with the fugitive dust emission inventory of typical domestic provinces and cities, we found that the maximum among the contribution rates of soil wind erosion dust to the local total fugitive dust PM2.5 emission inventory was about 4 orders of magnitude higher than the minimum. This study provided a wind erosion equation and a determination method of parameter values. The remote sensing interpretation, China soil dataset, and meteorological data of each district in Beijing were used to achieve the spatial distribution of the vegetation coverage factor (V), soil erodibility index (I), and climatic factors (C) in the plain area of Beijing. This study also estimated the emission factor of soil wind erosion dust and its spatial distribution. The main conclusions are as follows: ① Taking 2017 and Beijing city as an example, it was found that the climatic factor (C) was underestimated to different extents by domestic scholars, and PM2.5 emission factors were overestimated or underestimated. ② V, I, and C showed apparent spatial differences and the average values of them were 0.63±0.09, 188±73, and 0.029±0.009, respectively. The maximum values of V, I, and C were 1.5, 2.1, and 4.5 times the minimum among all districts, respectively. ③ The PM2.5 emission factor of soil wind erosion dust in Beijing showed a high spatial distribution in the northwest and southeast. The average emission factor of the city was (0.0018±0.0008) t·(hm2·a)-1, which is 0.54 times the highest emission factor (Xicheng District) and 3.12 times the lowest (Pinggu District). The area proportions of standardized emission factors with higher intensity (0.6 to 0.8] and high intensity (0.8 to 1.0] was 0.72% and 0.04%, respectively.

[Emission Status and Standards of Volatile Organic Compounds from Chinese and Foreign Bulk Petroleum Terminals].

Chinese emission standard of air pollutants for bulk gasoline terminals (GB 20950-2007) stipulate standards for vapor emissions during gasoline storage and receiving in bulk gasoline terminals. However, the standards are not applicable to crude oil, aviation kerosene, naphtha, and other kinds of oil. We assess emission standards or directives for vapor processing equipment in terminals in the United States (US) and European Union (EU), and analyze the emission status of vapor processing equipment in three typical cities in China. We further propose revisions to GB 20950-2007. We made the following observations. ① US and EU standards include scope not only for gasoline, but also crude oil and other organic liquids. ② The emission limits of non-methane hydrocarbons defined in GB 20950-2007 are i) 0.5, 1.8, and 8.9 times those defined in Subpart XX, Subpart R, and Subpart Y in the US federal regulations, ii) 1.8 and 3.1 times those defined in Rule 462 and Rule 1142 in southern California law, and iii) 0.7 and 500 times those defined in EU and German directives, respectively. The vapor leakage limit for general areas of China is 0.5 times that defined in Subpart XX of the US standards, whereas the limits for some other specific areas of China, are 0.7 and 2.0 times those defined by Rule 462 and Rule 1142 in southern California law. ③ The numerical range of P5th-P95th of NMHC emissions from the inlet and outlet of vapor processing equipment in three typical cities of China were 115-811 g·m-3 and 0.1-20.0 g·m-3, respectively. The proportion of NMHC emission concentrations less than or equal to 10 g·m-3 at the outlet of vapor processing equipment was>85%. We suggest that the scope of application of GB 20950-2007 should be extended to crude oil, gasoline (including ethanol gasoline), aviation kerosene, and naphtha. The emission concentration limit of NMHC from vapor processing equipment should be tighten from 25 g·m-3 to 20 g·m-3, with a emission limit of 10 g·m-3 added for particular cases.

[Application of Test Method for Dust Suppression Efficiency of Wind Erosion Dust Suppressant].

Wind erosion dust suppressant is an effective measure for controlling wind erosion dust. This study used the Portable In-Situ Wind Erosion Laboratory (PI-SWERL) to evaluate the efficiency of domestic and foreign dust suppressants and to compare their control efficiency of PM2.5 in terms of spraying methods, dilution factors, and wind speed. The following results were noted.① According to the recommended dilution factor, G and Enviroseal (ES) dust suppressant solutions were treated and tested, respectively. The control efficiency of particulate matter with diameters less than 2.5 µm (PM2.5) corresponding to the droplet spraying method was better than the atomized spraying method; the G dust suppressant efficiency, at 99.5%, was better than ES and water, at 94.0% and 77.5%, respectively, at 17.2 m·s-1, which is equivalent to grade 8 wind. ② The G dust suppressant with dilution factors of 50, 100, 150, 200, and 400 times was tested. The dust suppression efficiency at a wind speed of 17.2 m·s-1 was 99.7%, 99.5%, 99.7%, 98.1%, and 95.9%, respectively. The best cost-effective dilution factor of G dust suppressant was 150 times. The efficiency of dust suppressants increased when the wind speed increased between 13.1 m·s-1 and 17.2 m·s-1. ③ The method of using PI-SWERL to test the efficiency of wind erosion dust suppressant can quantify the suppression efficiency of dust suppressant on PM2.5. It is recommended to conduct dust suppression during effective periods and to practice environmentally friendly methods of wind erosion dust suppression.

[Determination of flavonoids constituents in epimedium total flavone capsule and research on its anti-osteoporosis activity].

To develop a rapid resolution liquid chromatography (RRLC) method for the simultaneous determination of epimedoside A, epimedin A1, epimedin A, epimedin B, epimedin C, icariin, baohuosideⅡ, icarisideⅠ, sagittatoside B, 2"-O-rhamnosyl icarisideⅡ, and baohuosideⅠin epimedium total flavone capsule. At the same time, the effects of the above 11 compounds on osteogenic differentiation of MC3T3-E1 cells were investigated by detecting the content of alkaline phosphatase (AKP). The results showed that baohuoside Ⅱ had the highest activities, and both the activities of baohuoside Ⅱ and icariside Ⅰ were stronger than those of icariin.In this study, the content determination method of flavonoid glycosides was established, and the anti-osteoporosis effect of monomers was compared, providing technical support for the study of the pharmacodynamic and mechanism of Epimedium total flavone capsule.

[Emission Characteristics of Wind-Eroded Dust from Concrete Batching Plants in Beijing].

Concrete batching plants are a typical source of fugitive dust in Beijing. In this study, two concrete batching plants in Beijing were used to test wind erosion of dust with a Portable In-suit Wind Erosion Laboratory (PI-SWERL) designed by the Desert Research Institute (DRI). Sand and aggregate storage piles and paved roads in concrete batching plants were tested to determine the emission characteristics of wind eroded dust. Combining the frequencies of disturbance of storage piles and paved road surface with local meteorological data, localized wind erosion dust emission factors of PM2.5 were established. Results demonstrate that:①There are small differences in daily average emission factors for PM2.5 between the aggregate warehouse entrance area, concrete loading area, social road import area, and concrete batching plant entrance area, with these being 0.45, 0.41, 0.31, and 0.30 kg·(hm2·d)-1, respectively. ②Daily average emission factors for PM2.5 of coarse stone, fine stone, coarse sand, and fine sand storage piles are 0.10, 0.12, 0.26, and 2.02 kg·(hm2·d)-1, respectively. Emission factors of fine sand storage piles are 20.5, 16.8, and 7.7 times greater than those of coarse stone, fine stone, and coarse sand, respectively, and spring emission factors are 6.4, 3.4, and 1.3 times greater than those of summer, autumn, and winter, respectively. ③Daily average emission factors for PM2.5 of storage piles and paved roads are 1.13 and 0.37 kg·(hm2·d)-1, respectively 3.9 and 1.3 times higher than the wind erosion factor from storage piles from AP-42 files (c11s12 concrete batching, 1995); the uncertainty range of the emission factor is 34%-92%. ④It is recommended to strengthen watering, sweeping, and cleaning of paved roads, and to ensure fully enclosed storage and use of spray water to reduce wind erosion of dust from storage piles, especially from fine sand piles.

[VOCs Emission Inventory of Service Stations in a Subcenter (Tongzhou District) of the City of Beijing].

As a subcenter of the city of Beijing, Tongzhou District is faced with enormous pressure from the rapid growth of VOCs emissions from service stations. In this study, a set of bottom-up VOCs inventory estimation methods for service stations in Tongzhou District is established. Using local VOCs emission factors of service stations in Beijing, combined with gasoline and diesel sales from every service station, a high resolution VOCs emission inventory of service stations in Tongzhou District from 2015 to 2022 was established. The results showed the following. ①An online monitoring system (OMS) based on unloading, refueling, and tank pressure vapor emission control measures can reduce the VOCs emission factor from 190 mg·L-1 to 115 mg·L-1, and when the percent onboard refueling vapor recovery system (ORVR) Penetration reaches to about 50%, the emission factors can be reduced to 131 mg·L-1 and 96 mg·L-1, respectively. The VOCs emission factor (13 mg·L-1) of diesel from the service station is 0.8% of the uncontrolled emission factor (1552 mg·L-1) of gasoline. ②The amount of VOCs emissions from service stations in Tongzhou District was 97.8 t·a-1 in 2015, and the emissions of gasoline and diesel were 96.2 t·a-1 and 1.6 t·a-1, respectively, accounting for 98.4% and 1.6%. The emissions were mainly concentrated in the area surrounding the new Beijing Municipal Government site. ③After implementation of the vapor recovery requirements of "Beijing's Clean Air Action Plan from 2013-2017," considering the increase in oil sales from 2017 to 2022, VOCs emissions of gasoline and diesel from service stations will decrease by 9% and 6%, respectively, compared to those of 2015 in Tongzhou District. Assuming that the OMS will also be installed at 28 (2000-5000) t·a-1 service stations by the end of 2022, VOCs emissions of service stations will be reduce by 13% compared to those of 2015. ④The measure of restricting the number of vehicles in operation by 50% can reduce VOCs emissions of service stations by (22±12)% every day during 2014 Asia-Pacific Economic Cooperation conference (APEC). ⑤It is suggested to strengthen vapor recovery supervision on service stations in the area surrounding the new Beijing Municipal Government site, and in summer and refueling idle such as in noon.

[Emission Characteristics of Wind Erosion Dust from Topsoil of Urban Roadside-Tree Pool].

This study characterized the wind erosion dust emissions from topsoil of urban roadside-tree pool. The study area is the Xicheng District of Beijing and uses GIS to obtain the spatial distribution of various road mileages. A full bore investigation method was carried out to survey tree pool in the Zhanlanlu Subdistrict to obtain the activity level of tree pool in the Xicheng district. The portable in situ wind erosion laboratory (PI-SWERL) was used to determine the emission factors of PM2.5 from the wind erosion dust from tree pool and to estimate the PM2.5 emission inventory of tree pool in the Xicheng District in 2016. The results showed that:①The annual emission factors per unit area of PM2.5 from tree pool of freeways' frontage roads, major roads, minor roads, and alleys are 47.9, 7.9, 14.9, and 29.9 g·(m2·a)-1, respectively. The reduction rate of PM2.5 emission factors from tree pool by precipitation was about 30.3% in 2016. ②The annual emission factors per unit mileage of PM2.5 from the tree pool of freeways' frontage roads, major roads, minor roads, branch roads, and alleys are 2.57, 2.33, 4.04, 7.31, and 5.44 kg·(km·a)-1, respectively, and the factors for branch roads are 1.3, 1.8, 2.8, and 3.1 times as much as those for alleys, minor roads, freeways' frontage roads, and major roads, respectively. Taking the emission factor for minor roads as an example, the winter emission factor is 1.3, 7.3, and 8.7 times greater than that in the spring, summer, and autumn, respectively. ③PM2.5 emissions from the tree pool in the Xicheng District of Beijing are 1.60 t·a-1, and the uncertainty range of the emission inventory is -143%~184%. The emissions in winter are 0.68 t·a-1, which are 1.1, 1.42, and 5.1 times greater than that in the spring, summer, and fall, respectively. The emission values for freeways' frontage roads, major roads, minor roads, collectors, and alleys account for 5.6%, 8.7%, 23.2%, 4.1%, and 58.4% of the total emissions, respectively. It is recommended that the urban roadside-tree pool be covered to reduce wind erosion dust emissions with materials that do not affect the growth of trees as soon as possible.

Epidemiological investigation of Mycoplasma Synoviae in native chicken breeds in China.

BACKGROUD: Mycoplasma synoviae (M. synoviae) is widely distributed around the world, and leads to serious economic losses in the world every year. Nevertheless, the incidence and epidemiology of M. synoviae infection in China have remained unclear. RESULTS: In this study we demonstrate that over 9773 broiler chicken flocks in 16 Chinese provinces were affected by M. synoviae between 2010 and 2015. Our epidemiological study revealed that M. synoviae was widely prevalent in multi-aged Chinese native breeder chickens, and the prevalence of M. synoviae in embryos of breeders reached up to 16.29%. In addition, our data showed that chickens aged 14 days or younger carried simultaneously high levels of maternal antibody against M. synoviae and high M. synoviae infection (10%), and low M. synoviae antibody levels in breeders and high proportion of M. synoviae infection in embryos could increase the chances of incidence in the offspring. Finally, our results also indicated that 3- to 7-week-old chickens might be most the susceptible to M. synoviae and, therefore, might play a key role in the horizontal transmission of M. synoviae. CONCLUSION: Our findings suggest that M. synoviae is widely circulating in Chinese native chickens, accordingly, effective control measures are urgently needed to control the spread.

[Fugitive Dust Emission Characteristics from Building Construction Sites of Beijing].

Particulate matter (PM) is the primary air pollutant in Beijing, and its emission control is an important direction of air pollution prevention and control. Construction dust plays a significant role in the source of airborne particulate matter in Beijing. Due to population growth and economic development, the demand for residential and office space has been increasing which results in a high construction area in Beijing and dust pollution caused by construction activities. However, there are few studies focusing on fugitive dust emissions from construction sites and their contribution to air pollution in Beijing. Under this background, this paper established an estimation model of dust emission from construction sites, and used the localized emission factor to calculate the dust emission from 2000 to 2015 in Beijing, identified the emission characteristics and laws of construction dust emission and quantified the uncertainty range of the emissions. The WRF/CMAQ model system was used to simulate the contribution of dust pollution to quantify its influence on air quality. The results showed that the dust emission from construction sites in Beijing has been increasing, but the construction area is falling in recent years. However, the emission of PM is still high and needs to be paid enough attention. In the spatial distribution, the dust emissions in summer and autumn are larger than those in other seasons. As for spatial distribution, the construction dust is mainly concentrated in the urban function extension area and suburban area, which is related to the extension of population activities and the gradual development of urbanization. The contribution of construction dust to PM10 and PM2.5 concentration in the ambient air can reach 31.3 µg·m-3 and 9.6 µg·m-3, respectively. Through scenarios analysis, for further reduction of the emission from construction sites in 2030, more stricter standard for green construction and powerful supervision are needed.

Pathogenicity and genetic characterization of a duck Tembusu virus associated with egg-dropping in Muscovy ducks.

Duck Tembusu virus (DTMUV) has spread to the major duck-farming region in China, causing acute egg-production drop in Chinese duck population. In this study, we characterized a DTMUV strain (named GD2014) isolated from an egg-production drop duck farm in Guangdong province, South China. The virus was pathogenic to Muscovy duck embryos and caused severe egg production drop for laying Muscovy ducks. The genome sequence of GD2014 shared 97-99% homologies with other waterfowl-origin Tembusu viruses, and shared 89% identities with MM1775 strain isolated from mosquito. Phylogenetic analysis of entire open reading frame (ORF), E gene and NS5 gene indicated that GD2014 belonged to Ntaya group. These results have implications for understanding the orgin, emergence and pathogenicity of DTMUV as well as for the development of vaccines and diagnostics based on epidemiological data.

[Study and Application of Test Method for VOCs Emission Factor of Refueling in Service Station].

VOCs emission of service station is one of the main sources of VOCs in Beijing. Uncontrolled emission factor (UEF) of refueling in China, US EPA, EEA respectively is 2.16, 1.31 and 1.00 times of CARB UEF (1008 mg·L-1). China's gasoline standards have changed in the last 20 years, and there is an urgent need to carry out the localization of gasoline refueling VOCs emission factor research. This paper compared test methods for refueling emission factors of European Union (EU) and California Air Resources Board (CARB) and found that the EU method was simpler and easier to operate than the CARB method, so we processed refueling VOCs emission factors test device in reference to EU test methods and chose a set of United States Stage Ⅱ vapor recovery system in Beijing service stations to carry out studies on VOCs emission factors. The results showed that: 1 For the fuel test tank, refueling vapor recovery efficiencies were 0.93 and 0.83 times of air to liquid volume ratio (A/L) of Stage Ⅱ respectively in winter and summer. Refueling emission factor in summer was greater than that in winter, and its recovery efficiency was lower than that in winter. 2 For the social vehicles, winter and summer refueling UEF respectively was (525±42) mg·L-1 and (963±174) mg·L-1, at the same time was 0.52 and 0.95 times of CARB refueling UEF (1008 mg·L-1) in A/L=0.The average value of emission factors respectively was (55±30) mg·L-1 and (112±108) mg·L-1 in A/L 1.05-1.07 in winter and summer. 3Refueling UEF without vapor recovery of social vehicles was chosen as the localized summer and winter refueling UEF in Beijing, we could calculate the emission factor of vapor recovery in different A/L combining with the linear equation of the fuel test tank.

[Rapid identification of chemical components in Congrong Zonggan capsule by UPLC-Q-TOF-MS/MS].

This study was aimed to qualitatively analyze the chemical components in Congrong Zonggan capsule by using ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry method (UPLC-Q-TOF-MS/MS). An Agilent SB-C18 Rapid Resolution HD (3.0 mm×100 mm,1.8 µm) was used with acetonitrile (A) - 0.1% formic acid solution (B) as the mobile phase for gradient elution. The flow rate was 0.2 mL•min⁻¹; the detection wavelength was set at 330 nm and the column temperature was maintained at 30 ℃. Electrospray ion (ESI) source was applied for the qualitative analysis under the negative ion mode. Finally, based on comparison with standard samples, database matching analysis and reviewing relevant literature, 41 compounds were identified from Congrong Zonggan capsule. This method could be used to rapidly detect the chemical components in Congrong Zonggan capsule, providing reference for the quality control of Congrong Zonggan capsule and laying a foundation for the further study on active components mechanism.