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Laboratory diagnosis for malaria in the elimination phase in China: efforts and challenges

《医学前沿(英文)》 2022年 第16卷 第1期   页码 10-16 doi: 10.1007/s11684-021-0889-7

摘要: Malaria remains a global health challenge, although an increasing number of countries will enter pre-elimination and elimination stages. The prompt and precise diagnosis of symptomatic and asymptomatic carriers of Plasmodium parasites is the key aspect of malaria elimination. Since the launch of the China Malaria Elimination Action Plan in 2010, China has formulated clear goals for malaria diagnosis and has established a network of malaria diagnostic laboratories within medical and health institutions at all levels. Various external quality assessments were implemented, and a national malaria diagnosis reference laboratory network was established to strengthen the quality assurance in malaria diagnosis. Notably, no indigenous malaria cases have been reported since 2017, but the risk of re-establishment of malaria transmission cannot be ignored. This review summarizes the lessons about malaria diagnosis in the elimination phase, primarily including the establishments of laboratory networks and quality control in China, to better improve malaria diagnosis and maintain a malaria-free status. A reference is also provided for countries experiencing malaria elimination.

关键词: malaria     laboratory diagnosis     quality control     malaria elimination     China    

Optimized determination of airborne tetracycline resistance genes in laboratory atmosphere

Lu Song, Can Wang, Yizhu Wang

《环境科学与工程前沿(英文)》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1274-5

摘要: Abstract • Sampling parameters with high efficiency was determined. • Operational process to detect airborne ARGs was optimized. • Providing research basis to control airborne ARGs of a laboratory atmosphere Antibiotic resistance genes (ARGs) have been detected in various atmospheric environments. Airborne ARGs transmission presents the public health threat. However, it is very difficult to quantify airborne ARGs because of the limited availability of collectable airborne particulate matter and the low biological content of samples. In this study, an optimized protocol for collecting and detecting airborne ARGs was presented. Experimental results showed that recovery efficiency tended to increase initially and then declined over time, and a range of 550–780 copies/mm2 of capture loading was recommended to ensure that the recovery efficiency is greater than 75%. As the cell walls were mechanically disrupted and nucleic acids were released, the buffer wash protects ARGs dissolution. Three ratios of buffer volume to membrane area in buffer wash were compared. The highest concentrations of airborne ARGs were detected with 1.4 µL/mm2 buffer wash. Furthermore, the majority of the cells were disrupted by an ultrasonication pretreatment (5 min), allowing the efficiency ARGs detection of airborne samples. While, extending the ultrasonication can disrupt cell structures and gene sequence was broken down into fragments. Therefore, this study could provide a theoretical basis for the efficient filter collection of airborne ARGs in different environments. An optimized sampling method was proposed that the buffer wash was 1.4 µL/mm2 and the ultrasonication duration was 5 min. The indoor airborne ARGs were examined in accordance with the improved protocol in two laboratories. The result demonstrated that airborne ARGs in an indoor laboratory atmosphere could pose the considerable health risk to inhabitants and we should pay attention to some complicated indoor air environment.

关键词: Airborne tetracycline resistance genes     Filter sampling     Capture loading     Membrane pretreatment     Indoor laboratory atmosphere    

Erratum to: Optimized determination of airborne tetracycline resistance genes in laboratory atmosphere

Lu Song, Can Wang, Yizhu Wang

《环境科学与工程前沿(英文)》 2020年 第14卷 第6期 doi: 10.1007/s11783-020-1289-y

Bridging the gap between laboratory and field moduli of asphalt layer for pavement design and assessment

Huailei CHENG; Liping LIU; Lijun SUN

《结构与土木工程前沿(英文)》 2022年 第16卷 第3期   页码 267-280 doi: 10.1007/s11709-022-0811-7

摘要: Asphalt pavement is a key component of highway infrastructures in China and worldwide. In asphalt pavement design and condition assessment, the modulus of the asphalt mixture layer is a crucial parameter. However, this parameter varies between the laboratory and field loading modes (i.e., loading frequency, compressive or tensile loading pattern), due to the viscoelastic property and composite structure of the asphalt mixture. The present study proposes a comprehensive frequency-based approach to correlate the asphalt layer moduli obtained under two field and three laboratory loading modes. The field modes are vehicular and falling weight deflectometer (FWD) loading modes, and the laboratory ones are uniaxial compressive (UC), indirect tensile (IDT), and four-point bending (4PB) loading modes. The loading frequency is used as an intermediary parameter for correlating the asphalt layer moduli under different loading modes. The observations made at two field large-scale experimental pavements facilitate the correlation analysis. It is found that the moduli obtained via laboratory 4PB tests are pretty close to those of vehicular loading schemes, in contrast to those derived in UC, IDT, and FWD modes, which need to be adjusted. The corresponding adjustment factors are experimentally assessed. The applications of those adjustment factors are expected to ensure that the moduli measured under different loading modes are appropriately used in asphalt mixture pavement design and assessment.

关键词: asphalt mixture layer     stiffness modulus     loading mode     UC/4PB/IDT     FWD     frequency    

Numerical and experimental analyses of methane leakage in shield tunnel

《结构与土木工程前沿(英文)》   页码 1011-1020 doi: 10.1007/s11709-023-0956-z

摘要: Tunnels constructed in gas-bearing strata are affected by the potential leakage of harmful gases, such as methane gas. Based on the basic principles of computational fluid dynamics, a numerical analysis was performed to simulate the ventilation and diffusion of harmful gases in a shield tunnel, and the effect of ventilation airflow speed on the diffusion of harmful gases was evaluated. As the airflow speed increased from 1.8 to 5.4 m/s, the methane emission was diluted, and the methane accumulation was only observed in the area near the methane leakage channels. The influence of increased ventilation airflow velocity was dominant for the ventilation modes with two and four fans. In addition, laboratory tests on methane leakage through segment joints were performed. The results show that the leakage process can be divided into “rapid leakage” and “slight leakage”, depending on the leakage pressure and the state of joint deformation. Based on the numerical and experimental analysis results, a relationship between the safety level and the joint deformation is established, which can be used as guidelines for maintaining utility tunnels.

关键词: shield tunnel     harmful gas leakage     numerical analysis     laboratory test    

Partitioning of heavy metals during municipal solid waste incineration on a laboratory fluid bed furnace

LI Jianxin, YAN Jianhua, CHI Yong

《能源前沿(英文)》 2007年 第1卷 第3期   页码 359-364 doi: 10.1007/s11708-007-0054-2

摘要: The content of heavy metals in the main physical compositions of municipal solid waste (MSW) is analyzed. The effects of temperature, chlorine and water on the partitioning of heavy metals are studied using a laboratory fluidized-bed (FB) furnace with simulated MSW composition. The experimental results show that temperature and chloride content in the feed have significant influence on the volatility of heavy metals, especially those of lower boiling point such as Hg, Cd and Zn. The influence of water is slight.

关键词: partitioning     municipal     volatility     significant influence     temperature    

PulseNet China, a model for future laboratory-based bacterial infectious disease surveillance in China

null

《医学前沿(英文)》 2012年 第6卷 第4期   页码 366-375 doi: 10.1007/s11684-012-0214-6

摘要:

Surveillance is critical for the prevention and control of infectious disease. China’s real-time web-based infectious disease reporting system is a distinguished achievement. However, many aspects of the current China Infectious Disease Surveillance System do not yet meet the demand for timely outbreak detection and identification of emerging infectious disease. PulseNet, the national molecular typing network for foodborne disease surveillance was first established by the Centers for Disease Control and Prevention of the United States in 1995 and has proven valuable in the early detection of outbreaks and tracing the pathogen source. Since 2001, the China CDC laboratory for bacterial pathogen analysis has been a member of the PulseNet International family; and has been adapting the idea and methodology of PulseNet to develop a model for a future national laboratory-based surveillance system for all bacterial infectious disease. We summarized the development progress for the PulseNet China system and discussed it as a model for the future of China’s national laboratory-based surveillance system.

关键词: infectious disease     laboratory-based infectious disease surveillance     pulse field gel electrophoresis     multilocus sequencing typing     PulseNet China    

Genome-edited crops: how to move them from laboratory to market

Kunling CHEN, Caixia GAO

《农业科学与工程前沿(英文)》 2020年 第7卷 第2期   页码 181-187 doi: 10.15302/J-FASE-2020332

摘要:

Recent breakthroughs in CRISPR technology allow specific genome manipulation of almost all crops and have initiated a revolution in precision crop breeding. Rationally-based regulation and widespread public acceptance are needed to propel genome-edited crops from laboratory to market and to translate this innovative technology into agricultural productivity.

关键词: CRISPR/Cas     genome editing     base editing     precision breeding     regulation    

Bioengineering protection mechanism of city rock slope and its laboratory test

Desong JIANG, Minghua ZHAO, Chong JIANG,

《结构与土木工程前沿(英文)》 2009年 第3卷 第4期   页码 414-421 doi: 10.1007/s11709-009-0055-9

摘要: Based on the features of rock slope bioengineering protection, the ecology protection mechanism of the urban rock slope was discussed with the mechanics effect of plants and rock slope, and the reinforcement action mechanism of rock slope by plant root system was analyzed as well. Then, the corresponding mechanical model was proposed, from which the formula to calculate the increased shearing strength of the root system-earth compound body was derived. Moreover, the side slope rainfall interception, the runoff lagging, the soil antiseepage, and the soil layer consolidating effect were studied, respectively. Furthermore, the indoor model experiment of urban crag rock slope ecology protection was designed and completed, in which various grasses to plant in slope with different angles, solid earth forms, and the different strengthening earth mechanism were studied. Finally, the present method was applied in an engineering project, from which the antiwashing behavior of three kind of grasses (i.e., the Bahiagrass, the tall fescue, and the Bermudagrass) planted in the slope with an angle of 38°, 48°, and 58°, respectively, and different strengthening structures (i.e., the diamond wire netting, the geocell and the three-dimensional network) were obtained. The application results also show that the effect of geocell structure is the best one followed by the three-dimensional net and the diamond wire net. The antiwashing capability per unit area has a critical slope angle of about 25°. The reinforcing effect of Bermudagrass is better than the Bahiagrass and tall fescue.

关键词: indoor     engineering project     protection mechanism     different     runoff lagging    

Hydrologic experiments and modeling of two laboratory bioretention systems under different boundary conditions

Ruifen Liu, Elizabeth Fassman-Beck

《环境科学与工程前沿(英文)》 2017年 第11卷 第4期 doi: 10.1007/s11783-017-0951-5

摘要: Hydrologic performance of bioretention systems is significantly influenced by the media composition and underdrain configuration. This research measured hydrologic performance of column-scale bioretention systems during a synthetic design storm of 25.9 mm, assuming a system area:catchment area ratio of 5%. The laboratory experiments involved two different engineered media and two different drainage configurations. Results show that the two engineered media with different sand aggregates were able to retain about 36% of the inflow volume with free drainage configuration. However, the medium with marine sand is better at delaying the occurrence of drainage than the one with pumice sand, denoting the better detention ability of the former. For both engineered media, an underdrain configuration with internal water storage (IWS) zone lowered drainage volume and peak drainage rate as well as delayed the occurrence of drainage and peak drainage rate, as compared to a free drainage configuration. The USEPA SWMM v5.1.11 model was applied for the free drainage configuration case, and there is a reasonable fit between observed and modeled drainage-rates when media-specific characteristics are available. For the IWS drainage configuration case, air entrapment was observed to occur in the engineered medium with marine sand. Filling of an IWS zone is most likely to be influenced by many factors, such as the structure of the bioretention system, medium physical and hydraulic properties, and inflow characteristics. More research is needed on the analysis and modeling of hydrologic process in bioretention with IWS drainage configuration.

关键词: Bioretention     Hydrologic process     Underdrain configuration     SWMM     Modeling    

Laboratory study on high-temperature adsorption of HCl by dry-injection of Ca(OH)

Junjun TAN,Guohua YANG,Jingqiao MAO,Huichao DAI

《环境科学与工程前沿(英文)》 2014年 第8卷 第6期   页码 863-870 doi: 10.1007/s11783-013-0618-9

摘要: Combustion-generated hydrogen chloride (HCl) is considered to be a very hazardous acid gaseous pollutant. This paper presents a laboratory study on the dry adsorption of HCl. The experiments were conducted in a dual-layer granular bed filter, at gas temperatures of 500°C–700°C and (Ca)/ (Cl)molar ratios of 1.0–5.0 using the silver nitrate titration method by dry adsorbent powders Ca(OH) . Mainly, the adsorption efficiency of HCl and utilization efficiency of Calcium were studied, by varying relevant factors including (Ca)/ (Cl), temperature, feeding method, water vapor and CO . With a relatively higher HCl concentration of 1000 ppm, the experimental results revealed that 600°C may be the optimum temperature for HCl adsorption when optimum (Ca)/ (Cl) was 2.5 in our tests. The results also demonstrated that the feeding at a constant pressure was more effective, and the HCl adsorption efficiency could rapidly reach over 90% with (Ca)/ (Cl) = 2.5 at 600°C. Furthermore, the HCl adsorption efficiency was found to be slightly promoted by water vapor, while could be impeded by CO , and the utilization efficiency of calcium could be up to 74.4% without CO , while was only 36.8% with CO when (Ca)/ (Cl) was 2.5 at 600°C.

关键词: acid gas HCl     Ca(OH)2     dry adsorption     high temperature     dual-layer granular bed filter    

Investigation of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational

《化学科学与工程前沿(英文)》 2022年 第16卷 第7期   页码 1149-1163 doi: 10.1007/s11705-021-2096-0

摘要: The production of solar fuels via the photoreduction of carbon dioxide to methane by titanium oxide is a promising process to control greenhouse gas emissions and provide alternative renewable fuels. Although several reaction mechanisms have been proposed, the detailed steps are still ambiguous, and the limiting factors are not well defined. To improve our understanding of the mechanisms of carbon dioxide photoreduction, a multiphysics model was developed using COMSOL. The novelty of this work is the computational fluid dynamic model combined with the novel carbon dioxide photoreduction intrinsic reaction kinetic model, which was built based on three-steps, namely gas adsorption, surface reactions and desorption, while the ultraviolet light intensity distribution was simulated by the Gaussian distribution model and Beer-Lambert model. The carbon dioxide photoreduction process conducted in a laboratory-scale reactor under different carbon dioxide and water moisture partial pressures was then modeled based on the intrinsic kinetic model. It was found that the simulation results for methane, carbon monoxide and hydrogen yield match the experiments in the concentration range of 10−4 mol·m–3 at the low carbon dioxide and water moisture partial pressure. Finally, the factors of adsorption site concentration, adsorption equilibrium constant, ultraviolet light intensity and temperature were evaluated.

关键词: carbon dioxide photoreduction     computational fluid dynamic simulation     kinetic model     Langmuir adsorption    

Biosensor-based assay of exosome biomarker for early diagnosis of cancer

《医学前沿(英文)》 2022年 第16卷 第2期   页码 157-175 doi: 10.1007/s11684-021-0884-z

摘要: Cancer imposes a severe threat to people’s health and lives, thus pressing a huge medical and economic burden on individuals and communities. Therefore, early diagnosis of cancer is indispensable in the timely prevention and effective treatment for patients. Exosome has recently become an attractive cancer biomarker in noninvasive early diagnosis because of the unique physiology and pathology functions, which reflects remarkable information regarding the cancer microenvironment, and plays an important role in the occurrence and evolution of cancer. Meanwhile, biosensors have gained great attention for the detection of exosomes due to their superior properties, such as convenient operation, real-time readout, high sensitivity, and remarkable specificity, suggesting promising biomedical applications in the early diagnosis of cancer. In this review, the latest advances of biosensors regarding the assay of exosomes were summarized, and the superiorities of exosomes as markers for the early diagnosis of cancer were evaluated. Moreover, the recent challenges and further opportunities of developing effective biosensors for the early diagnosis of cancer were discussed.

关键词: biosensor     exosome     cancer diagnosis    

Tomographic diagnosis of defects in hydraulic concrete structure

ZHAO Mingjie, XU Xibin

《结构与土木工程前沿(英文)》 2008年 第2卷 第3期   页码 226-232 doi: 10.1007/s11709-008-0027-5

摘要: The ultrasonic tomographic technology is applied to diagnose the defects in hydraulic concrete structure. In order to improve the precision of diagnoses, the wavelet transformation is used in the processing of ultrasonic signals. The influences of water, scale and orientation of defect, processing methods and theoretical model on image resolution are investigated. The experimental results indicate that the result of the tomographic diagnosis of a single defect is sensitive and the boundary can be clearly determined. However, the image resolution of multiple defects is not satisfactory. The water content and scale of a defect may significantly affect the imaging resolution. Defects with the orientation perpendicular to the direction of the diagnosis may have higher precision in diagnosing. The wavelet transformation technology can elevate the imaging resolution. The applied calculation model plays a very important role in improving the accuracy of detection.

关键词: satisfactory     processing     orientation     tomographic diagnosis     orientation perpendicular    

convolutional tree-inspired network: a decision-tree-structured neural network for hierarchical fault diagnosis

《机械工程前沿(英文)》 2021年 第16卷 第4期   页码 814-828 doi: 10.1007/s11465-021-0650-6

摘要: The fault diagnosis of bearings is crucial in ensuring the reliability of rotating machinery. Deep neural networks have provided unprecedented opportunities to condition monitoring from a new perspective due to the powerful ability in learning fault-related knowledge. However, the inexplicability and low generalization ability of fault diagnosis models still bar them from the application. To address this issue, this paper explores a decision-tree-structured neural network, that is, the deep convolutional tree-inspired network (DCTN), for the hierarchical fault diagnosis of bearings. The proposed model effectively integrates the advantages of convolutional neural network (CNN) and decision tree methods by rebuilding the output decision layer of CNN according to the hierarchical structural characteristics of the decision tree, which is by no means a simple combination of the two models. The proposed DCTN model has unique advantages in 1) the hierarchical structure that can support more accuracy and comprehensive fault diagnosis, 2) the better interpretability of the model output with hierarchical decision making, and 3) more powerful generalization capabilities for the samples across fault severities. The multiclass fault diagnosis case and cross-severity fault diagnosis case are executed on a multicondition aeronautical bearing test rig. Experimental results can fully demonstrate the feasibility and superiority of the proposed method.

关键词: bearing     cross-severity fault diagnosis     hierarchical fault diagnosis     convolutional neural network     decision tree    

标题 作者 时间 类型 操作

Laboratory diagnosis for malaria in the elimination phase in China: efforts and challenges

期刊论文

Optimized determination of airborne tetracycline resistance genes in laboratory atmosphere

Lu Song, Can Wang, Yizhu Wang

期刊论文

Erratum to: Optimized determination of airborne tetracycline resistance genes in laboratory atmosphere

Lu Song, Can Wang, Yizhu Wang

期刊论文

Bridging the gap between laboratory and field moduli of asphalt layer for pavement design and assessment

Huailei CHENG; Liping LIU; Lijun SUN

期刊论文

Numerical and experimental analyses of methane leakage in shield tunnel

期刊论文

Partitioning of heavy metals during municipal solid waste incineration on a laboratory fluid bed furnace

LI Jianxin, YAN Jianhua, CHI Yong

期刊论文

PulseNet China, a model for future laboratory-based bacterial infectious disease surveillance in China

null

期刊论文

Genome-edited crops: how to move them from laboratory to market

Kunling CHEN, Caixia GAO

期刊论文

Bioengineering protection mechanism of city rock slope and its laboratory test

Desong JIANG, Minghua ZHAO, Chong JIANG,

期刊论文

Hydrologic experiments and modeling of two laboratory bioretention systems under different boundary conditions

Ruifen Liu, Elizabeth Fassman-Beck

期刊论文

Laboratory study on high-temperature adsorption of HCl by dry-injection of Ca(OH)

Junjun TAN,Guohua YANG,Jingqiao MAO,Huichao DAI

期刊论文

Investigation of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational

期刊论文

Biosensor-based assay of exosome biomarker for early diagnosis of cancer

期刊论文

Tomographic diagnosis of defects in hydraulic concrete structure

ZHAO Mingjie, XU Xibin

期刊论文

convolutional tree-inspired network: a decision-tree-structured neural network for hierarchical fault diagnosis

期刊论文