Monitoring resistance of Plasmdium vivax: Point mutations in dihydrofolate reductase gene in isolates from Central China

<p>Abstract</p> <p>Background</p> <p>Malaria still represents a significant public health problem in China, and the cases dramatically increased in Central China after 2001. Antifolate resistance in <it>Plasmodium vivax </it>is caused by point mutations in genes encoding dihydrofolate reductase (<it>pvdhfr</it>) and dihydropteroate synthase (<it>pvdhps</it>). In this study, we used direct sequencing to investigate genetic variation in <it>pvdhfr </it>of malaria patients' samples from Central China.</p> <p>Results</p> <p>Among all the samples, 21.4% were wild-type, whereas mutations were detected at three codons (58, 61 and 117) including single mutant (34.6%) and double mutants (43.8%). The most prevalent mutant allele was the one with double mutation at codons 58 and 117 (24.6%). Three types of single mutation (S58R, T61M and S117N) were found in 2.1%, 11.8% and 20.9% of parasite isolates, respectively. The four <it>P. vivax </it>parasite populations in Central China also differed in <it>pvdhfr </it>allele frequencies.</p> <p>Conclusions</p> <p>This study suggested that <it>P. vivax </it>in Central China may be relatively susceptible to pyrimethamine. And it also highlights genotyping in the <it>pvdhfr </it>genes remains a useful tool to monitor the emergence and spread of <it>P. vivax </it>pyrimethamine resistance.</p

Malaria Elimination in the People’s Republic of China: Current Progress, Challenges, and Prospects

In China, the malaria elimination program was launched in 2010 with the objective to eliminate this disease by 2020. Large-scale malaria control and elimination actions have been conducted with significant success since inception of the nationwide program. The incidence of locally acquired malaria has declined sharply along with the concomitant decrease of malaria-endemic areas from 762 counties reporting malaria in 2010 to just two counties adjacent to border areas (Yunnan, China-Myanmar and Tibet, China-India) in 2016. In total, 1723 counties (79%) and 134 prefectures (52%) had completed the malaria elimination internal assessment by the end of 2016. The year 2017 was the first year without report of indigenous malaria cases throughout the country. Hence, this chapter is meant to share the lessons learned from malaria elimination in China benefiting countries on the way to malaria elimination

Digital Form Generation of Heritages in Historical District Based on Plan Typology and Shape Grammar: Case Study on Kulangsu Islet

Architectural heritage in historic districts, as a complex type of heritage, encompasses both the uniqueness of the building itself and also shows cultural and regional characteristics as a group, especially for the heritage site that contains multi-culture features. The digitalization research of this type of heritage often focuses on the digital archiving and modeling of heritages but rarely considers the combination of culture analysis and digitalization. This paper develops a digital form generation method for the heritages in historical districts by means of typological plan analysis, the Shape Grammar method, and Grasshopper software. Based on the case study of the modern Western-style house on Kulangsu, a world heritage site and historical district, this paper include three results: (1) dividing the layout plans of Kulangsu modern Western-style houses into three types, that is, native prototypes, foreign prototypes, and mixed prototypes, with 39 sub-types in total; (2) establishing shape grammar for the layout plans of Kulangsu modern Western-style houses with shape grammar sets and “S, L, R, I” expression rules; (3) creating a digital form generation method based on shape grammar result by Grasshopper software, including function cluster creation, function cluster connection and final model generation. This paper presents an example of quantitative analysis of heritage culture and a rapid modeling method of heritage, providing a reference for the construction of a heritage culture database and digital heritage management in historic districts

Effects of configuration parameters on lateral dynamics of tractor–two trailer combinations

The optimum configuration parameters of tractor–trailer combinations for lateral stability performance are proposed by adjusting the length of dolly and the second trailer’s center of gravity. A linear yaw plane model of vehicle combinations is adopted for dynamic analysis, and the model is calibrated by TruckSim. According to the yaw rate rearward amplification ratio of lateral response index, and combining the simulation results of MATLAB/Simulink, dolly and the second trailer are the dominate factors for lateral stability of vehicle combinations. Simulation results show that the distance between articulation joints of dolly is 1.6 m; simultaneously, the rate of distance between front hitch and center of gravity of the second trailer to its front and rear wheelbase is 0.41 and may gain the best lateral performance. Compared with configuration parameters of the original vehicle combinations, the results also illustrate that the one derived from adjustment approach reduces high-speed rearward amplification ratio by 11.4%. The proposed approach might be used for identifying desired design variables of the tractor–two trailer combinations and provided theoretical basis for stability tests

Biology, Bionomics and Molecular Biology of Anopheles sinensis Wiedemann 1828 (Diptera: Culicidae), Main Malaria Vector in China

China has set a goal to eliminate all malaria in the country by 2020, but it is unclear if current understanding of malaria vectors and transmission is sufficient to achieve this objective. Anopheles sinensis is the most widespread malaria vector specie in China, which is also responsible for vivax malaria outbreak in central China. We reviewed literature from 1954 to 2016 on An. sinensis with emphasis on biology, bionomics, and molecular biology. A total of 538 references were relevant and included. An. sienesis occurs in 29 Chinese provinces. Temperature can affect most life-history parameters. Most An. sinensis are zoophilic, but sometimes they are facultatively anthropophilic. Sporozoite analysis demonstrated An. sinensis efficacy on Plasmodium vivax transmission. An. sinensis was not stringently refractory to P. falciparum under experimental conditions, however, sporozoite was not found in salivary glands of field collected An. sinensis. The literature on An. sienesis biology and bionomics was abundant, but molecular studies, such as gene functions and mechanisms, were limited. Only 12 molecules (genes, proteins or enzymes) have been studied. In addition, there were considerable untapped omics resources for potential vector control tools. Existing information on An. sienesis could serve as a baseline for advanced research on biology, bionomics and genetics relevant to vector control strategies

Echelon Utilization of Retired Power Lithium-Ion Batteries: Challenges and Prospects

The explosion of electric vehicles (EVs) has triggered massive growth in power lithium-ion batteries (LIBs). The primary issue that follows is how to dispose of such large-scale retired LIBs. The echelon utilization of retired LIBs is gradually occupying a research hotspot. Solving the issue of echelon utilization of large-scale retired power LIBs brings not only huge economic but also produces rich environmental benefits. This study systematically examines the current challenges of the cascade utilization of retired power LIBs and prospectively points out broad prospects. Firstly, the treatments of retired power LIBs are introduced, and the performance evaluation methods and sorting and regrouping methods of retired power LIBs are comprehensively reviewed for echelon utilization. Then, the problems faced by the scenario planning and economic research of the echelon utilization of retired power LIBs are analyzed, and value propositions are put forward. Secondly, this study summarizes the technical challenges faced by echelon utilization in terms of security, performance evaluation methods, supply and demand chain construction, regulations, and certifications. Finally, the future research prospects of echelon utilization are discussed. In the foreseeable future, technologies such as standardization, cloud technology, and blockchain are urgently needed to maximize the industrialization of the echelon utilization of retired power LIBs

21 cases reports on haemangioma of spleen

The growing activity of hemangioma of spleen keeps unknown. To search theoretical basis for whether to take the operation, this study analyzed clinical data of 21 hemangioma patients, and 16 surgical specimens were analyzed immunohistochemistry of Ki-67, Bcl-2 and vascular endothelial growth factor (VEGF). Both 14 cases of cavernous hemangioma were positive for VEGF, and negative in capillary hemangioma, there was statistical significant difference between two types of hemangioma (P < 0.05). The most tumors had a low expression of Ki-67 with a mean ± standard deviation (SD) of 6.62 ± 6.24%, whereas the mean ± SD of Bcl-2 labeling index was 36.06 ± 19.05%. According to the statistical results, the expression of Ki-67 and Bcl-2 did not correlate with age, gender, tumor size, amount of tumor and angiomatous types. Hemangioma of spleen was one benign tumor with a tendency of slow growth. Therefore, operation should be strictly selected, we recommend observation of patients with small, asymptomatic splenic lesions, which meet the radiologic criteria for hemangiomas

Mapping transmission foci to eliminate malaria in the People’s Republic of China, 2010–2015: a retrospective analysis

Abstract Background China has initiated the National Malaria Elimination Action Plan, which aims to eliminate malaria by 2020. However, the transmission of malaria occurs sporadically or in distinct foci, which greatly hampers progress toward elimination in China and other countries. The object of this study was to foci categorization and evaluates whether the response met the requirements issued by the nation or WHO. Methods Residual transmissions were investigated and located with fine spatial resolution mapping from parasitological confirmed malaria cases by use of routine national surveillance data. The “1–3-7” timeframes were monitored for each focus between 2012 and 2015. Each focus was identified, and the application of appropriate measures was evaluated. Results A total of 5996 indigenous cases were recorded between 2010 and 2015; during this period, the number of cases declined by 99.1% (2010, n = 4262; 2015, n = 39). Most indigenous cases (92.5%) were reported in Anhui (n = 2326), Yunnan (n = 1373), Henan (n = 930), Hubei (n = 459), and Guizhou (n = 458). The temporal distribution showed that the indigenous malaria cases were clustered during the period of May to August. A total of 320 foci were carefully investigated and analyzed: 24 were active foci; 72, residual non-active foci; and 224 cleared-up foci. For the foci response evaluation, all the active foci were investigated within 7 days, while 80.2% of the residual non-active foci were responded within 7 days. In addition, reactive case detection (RACD) was carried out with 92.9% of the active foci and vector investigation carried out with 75%. For residual non-active foci, RACD was carried out with 83.2% and vector investigation with 78.2% of the foci. Conclusions This study used nationwide data to categorize foci in China and evaluate the response of these areas during the control and elimination phases. Our approach stratifies future control responses by identifying those locations where the elimination of endemic transmission is needed, such as in the counties at the China–Myanmar border and in Tibet. In addition, this study will help local CDC staff to reassess their needs and responses against different types of foci during the elimination and post-elimination phases