An initialization-improved equilibrium constant method was used for modelling the copper matte smelting process with flash technology. Initial molar amounts of species were calculated by distributing the amounts of given elements. The species containing the largest amount of one element was chosen to be the corresponding thermodynamic component. The equilibrium values were derived via the Newton-Raphson method and converted to industrial forecast values using the mechanical entrainment equations. The results indicate that the calculated equilibrium value for copper concentration in the slag is 0.32 wt.%, while the industrial forecast value is 1.03 wt.%, with the industrial value being 1.13 wt.%. The present model required only 31 outer loops to derive the approximate solution close to the equilibrium value. The iterative path during the computation is considerably reduced and the risk of non-convergence during the computation is decreased.

A method to upgrade the iron grade in copper slag was proposed using lime to decompose Al2O3-containing fayalite melt (AFMT). Thermodynamic calculations indicated that adjusting the CaO/AFMT ratio can yield a residual melt with a FeO concentration of 75-88 wt.% and produce Ca2SiO4. In-situ observations suggested that the reaction was impeded in some way. Quenching experiments revealed that the initial reaction products consisted of calcium ferrite compounds and FeO-CaO melt. At the FeO-CaO melt/AFMT interface, Ca2SiO4 particles precipitated, forming a dense Ca2SiO4 film that significantly impeded mass transfer. Although trace amounts of Al2O3 in AFMT temporarily enhanced mass transfer, they were insufficient to overcome this retardation effect. The decomposition reaction was far from achieving equilibrium, demonstrating a self-retardation effect. Measures must be implemented to eliminate this self-retardation effect and enhance the efficiency of reaction kinetics. Key words: lime; Al2O3-containing fayalite melt; Ca2SiO4 film; self-retardation; mass transfer

The emergence of advanced biotechnologies has intensified in recent years. The rapid development of these biotechnologies has had a wide and profound impact globally, with the majority on the frontier of biosecurity technologies. The global biosecurity situation is currently highly challenging, with the characteristics of internationalization, extremely serious harm, and complex development. The misuse and abuse of biotechnologies are common, which thereby endanger biosecurity. The international community and governments have attached great importance to cutting-edge biotechnologies and are implementing laws and regulations to control and prevent biosecurity-related influences. By tracking the frontier progress of the new technologies generated from gene editing, gene drives, synthetic biology, and related cross-disciplines as applied in the biosecurity field, we analyzed the development trends in biotechnologies and their potential influence. On the one hand, this paper proposes that there is an urgent need for global cooperation to formulate management, control strategies, and measures for cutting-edge technologies in biosecurity to jointly promote their sound development. On the other hand, the international community should jointly shoulder the responsibility for safeguarding biosecurity and restrict the biotechnologies to rational applications within legal and ethical frameworks. This paper aims to provide a reference for the prevention of misuse and abuse of biotechnologies and support global cooperation in biosecurity governance.

The efficient resource utilization of copper slag presents an urgent and significant challenge, with the decomposition of fayalite melt being a key aspect. In this paper, the method of lime decomposing fayalite melt was proposed to recover iron resources from copper slag in form of FeO-rich melt. However, in-situ observations revealed that this thermodynamically feasible reaction is challenging to advance due to certain influencing factors. Phase assemblages of the CaO/fayalite melt interfaces were studied to unravel the underlying reaction mechanism. The results indicated that the dense Ca2SiO4 coating formed at the CaO and fayalite melt interface exerted a severe deceleration effect on mass transfer and nearly terminated the reaction after 60 seconds. The FeO-CaO-SiO2 phase diagram shows that at 1300°C, adjusting the CaO and fayalite melt proportions allows for the attainment of equilibrium residual melt with FeO concentrations spanning 77.5-87.5%. Subsequent research should focus on taking measures to modify the structure of the Ca2SiO4 coating, eliminate its decelerating effect on mass transfer, and minimize the equilibrium time for this reaction. This study provides a thermodynamic basis for the sustainable and efficient recovery of iron resources from copper slag and indicates the direction for subsequent research.

Ultraviolet (UV) irradiation can effectively disinfect water contaminated with pathogens. However, the biological mechanisms of inactivation by different types of UV irradiation are unknown. The present study investigated the inactivation mechanisms of Alicyclobacillus acidoterrestris spores in water by low-pressure UV (LPUV) and medium-pressure UV (MPUV) using a quasi-collimated beam apparatus. Global transcriptomic data obtained by RNA-seq revealed 291 shared differentially expressed genes (DEGs) that damaged DNA, reduced biofilm formation, and had other reactions. The individual downregulated DEGs (n = 123) mainly related to cell motility, membrane transport, and metabolism were induced by LPUV, and in turn contributed to energy-saving and metabolic activity inhibition, forcing bacteria into a viable but non-culturable (VBNC) state. The individual upregulated DEGs (n = 244) following MPUV treatment were mainly enriched in cell motility, membrane transport, metabolism, DNA replication and repair, and spore germination pathways. This results in high-energy consumption, severe damage to genetic material, and enhanced spore germination accelerated cell death. Additionally, hub genes in the protein-protein interaction network were mainly involved in transcription and translation. These findings contribute to the comprehensive understanding of the inactivation mechanisms of different types of UV irradiation, and will improve applications of UV disinfection in the treatment of water.

目的 了解我国西藏、青海、广西、云南、黑龙江、北京、内蒙古共7个省、市、自治区的自备井水中4种阴离子F-、Cl-、NO3--N和SO42-的污染状况.按照美国环境保护局(US EPA)的健康风险评估模型评价健康风险.方法 对我国7个省、市、自治区的自备井237份水样,按照《生活饮用水标准检验方法水样的采集和保存》(GB/T 5750.2—2006)进行采样,检测F-、Cl-、NO3--N和SO42-4项水质指标并进行评价.使用US EPA的健康风险评估模型对F-和NO3--N进行非致癌风险评估.结果 7个省、市、自治区的自备井水阴离子总不合格率为19.78％.各地区水质污染情况差异大.黑龙江和北京自备井F-和NO3--N超标;西藏和青海SO42-和Cl-超标;云南和广西NO3--N超标;内蒙古则4种阴离子均超标.7个省、市、自治区的自备井水F-和NO3--N的非致癌健康风险(HI)平均值较小,未超出最高可接受风险(HI<1),F-和NO3--N均无显著的非致癌风险.结论 与南方省份相比,北方自备井水阴离子污染严重,尤其以内蒙古的阴离子污染较为突出,应根据不同阴离子污染水平加强水质监测与净化,保障饮水安全.

Human astrovirus (HAstV) is a single-stranded, positive-sense RNA virus and is the leading cause of viral gastroenteritis. However, despite its prevalence, astroviruses still remain one of the least studied enteroviruses. In this study, we sequenced 11 classical astrovirus strains from clinical samples collected in Shenzhen, China from 2016 to 2019, analyzed their genetic characteristics, and deposited them into GenBank. We conducted phylogenetic analysis using IQ-TREE software, with references to astrovirus sequences worldwide. The phylogeographic analysis was performed using the Bayesian Evolutionary Analysis Sampling Trees program, through Bayesian Markov Chain Monte Carlo sampling. We also conducted recombination analysis with the Recombination Detection Program. The newly sequenced strains were categorized as HAstV genotype 1, which is the predominant genotype in Shenzhen. Phylogeographic reconstruction indicated that HAstV-1 may have migrated from the United States to China, followed by frequent transmission between China and Japan. The recombination analysis revealed recombination events within and across genotypes, and identified a recombination-prone region that produced relatively uniform recombination breakpoints and fragment lengths. The genetic analysis of HAstV strains in Shenzhen addresses the current lack of astrovirus data in the region of Shenzhen and provides key insights to the evolution and transmission of astroviruses worldwide. These findings highlight the importance of improving surveillance of astroviruses.

目的 建立一种可同时检测沙门菌、副溶血弧菌和金黄色葡萄球菌3种食源性致病菌的多重荧光定量PCR技术.方法 利用沙门菌invA毒力基因、副溶血弧菌gyrase基因和金黄色葡萄球菌Sa442基因的特异性引物、探针,建立多重荧光定量PCR反应体系,完成特异性、敏感性评价,并用该法与国标法进行40份留样食品的检测比较.结果 各对引物、探针均能扩增出目标靶序列,3种检测通道无交叉干扰,对非目标菌无扩增信号,对沙门菌、副溶血弧菌和金黄色葡萄球菌的核酸检测限均达到102拷贝/μl;用多重荧光定量PCR法在40份食品样本中检出3份金黄色葡萄球菌阳性样本,其中1份国标法检测为阴性,其他样本检测结果完全一致.结论 建立了一种针对沙门菌、副溶血弧菌和金黄色葡萄球菌的多重荧光定量PCR检测方法,该方法具有良好的特异性与敏感性,可为食品安全提供技术支持.

目的 分析香草酸对脂环酸芽孢杆菌(Alicyclobacillus spp.)生长过程中嗅味代谢物释放的影响,评估中压紫外线(medium pressure ultraviolet,MP-UV)及其与过硫酸钾(potassium peroxodisulfate,PS)联用工艺对细菌与愈创木酚的控制效果.方法 将脂环酸芽孢杆菌分离菌株HY接种到含有不同质量浓度(0、20、40、50和100 mg/L)香草酸的培养基中,检测细菌数以及愈创木酚和2,6-二溴苯酚的释放情况.采用MP-UV和MP-UV/PS工艺分别对菌株HY及其嗅味代谢物愈创木酚进行照射,评估控制效果.结果 菌株HY在香草酸中能够释放愈创木酚,最高质量浓度为64.76μg/L;未检出2,6-二溴苯酚.MP-UV/PS(10 mg/L)工艺在照射剂量为20 mJ/cm2时,菌株HY灭活率为3.01 log,愈创木酚降解率为42.69％.结论 菌株HY能够利用香草酸代谢释放愈创木酚;MP-UV/PS工艺可以有效控制水中脂环酸芽孢杆菌及其嗅味代谢物愈创木酚的污染.

Biosafety issues have become a major threat to the health of humans, animals, and ecosystems worldwide. As problems with food production and the food supply chain have become of greater concern to consumers, issues involving biosafety and food safety from a developmental perspective need to be urgently addressed. The term, food biosafety, is the combination of the core concepts of biosafety and food safety. It refers to the effective prevention of biological threats to food production and the food supply chain by controlling foodborne diseases arising from the consumption of edible plants and animal products, by preventing the establishment of invasive species, by strictly controlling the use of antibiotics, agricultural chemicals and veterinary drugs in the food supply chain, and by initiating food defense and anti-terrorism measures to protect the health of humans, animals, and ecosystems, thereby maintaining sustainable development in China. This article provides theoretical support for the extension of food biosafety to propose an innovative plan for the international co-governance of food safety.

We read with interest the report in this Journal by Elgner and colleagues which emphasizes the critical role of person-to-person transmission in the epidemiology of Norovirus infection.1 Imported cases can rapidly spread allowing novel clones to disseminate rapidly. In the following, we will describe the genetic diversity and persistent transmission of norovirus in Shenzhen, China.

目的 比较我国南北不同地域自备水源的水质指标及微生物群落结构特征,评价其安全性.方法 本研究对我国南北5省边远散地域(北京郊区、黑龙江边境地域、内蒙古偏远地域、广西边境地域和云南边境地域)的317个自备水源进行采样,对浑浊度、总硬度和pH等水质指标进行分析,以高通量测序法对水样的微生物群落结构进行解析.结果 不同地域自备水源的水质和微生物群落结构存在较大的差异性,内蒙古偏远地域的阴离子指标最大值超标严重,在内蒙古-东和内蒙古-西两组水样中SO42-最大浓度值分别为543.12和666.33 mg/L,Cl-与NO3-也存在超标情况.变形菌门(Proteobacteria)是5省自备水源水样的第一优势菌门,其相对丰度为56.87％～99.38％.具有一定致病性的短波单胞菌(Brevundimonas)在各个样品中广泛分布(1.50％～27.27％).反硝化过程的典型菌株假单胞菌(Pseudomonas)存在于北京、黑龙江和内蒙古水样中(2.96％～38.41％),广西和云南并未检出.北京、黑龙江和内蒙古水样中各种功能表达基因的数量远高于广西和云南水样.结论 我国南北5省自备水源在水质和微生物群落特征方面均存在差异;较之南方自备水源,北方自备水源普遍受到了人类活动的影响.

Self-supplied wells, an important water resource in remote and scattered regions, are commonly deteriorated by environmental pollution and human activity. In this study, 156 self-supplied well-water samples were collected from remote and scattered areas of Inner Mongolia (NMG), Heilongjiang (HLJ), and the suburbs of Beijing (BJ) in Northern China. Twenty-four heavy metals were identified by using the inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES), and the associated human health risks were assessed by using standards of the US Environmental Protection Agency (US EPA). The concentrations of four heavy metals (As, Fe, Mn, and Tl) in HLJ, one heavy metal (Tl) in BJ, and ten heavy metals (Al, As, B, Cr, Fe, Mn, Mo, Se, Tl, and Zn) in NMG exceeded the limits set by China or the World Health Organization (WHO). The total carcinogenic risk (TCR) and total non-carcinogenic risk (THQ) exceeding set limits mainly occurred in NMG, compared to HLJ and BJ. Moreover, As accounted for 97.87% and 60.06% of the TCR in HLJ and BJ, respectively, while Cr accounted for 70.83% of the TCR in NMG. The TCR caused by Cd in all three areas had a negligible hazard (<10−4). As accounted for 51.11%, 32.96%, and 40.88% of the THQ in HLJ, BJ, and NMG, respectively. According to the results of the principal component analysis, heavy metals in well water from HLJ and NMG mainly originated from mixed natural processes and anthropogenic sources, whereas, in BJ, most heavy metals probably originated from natural sources. In the future, long-term monitoring of heavy metals in water from self-supplied wells should be conducted for an extensive range of well-water sites, and well water with high As contamination should be monitored more and fully assessed before being used as a drinking-water source.

Background: Recently, the spread of NDM-5-producing Escherichia coli has become a severe challenge in clinical therapy, which necessitates reliable detection and surveillance methods. However, limited information is available regarding the prevalence and dissemination of the bla NDM-5 gene in Escherichia coli in China. Therefore, we investigated the dissemination of the bla NDM-5 gene in carbapenem-resistant Escherichia coli isolates from different regions in China. Methods: A total of 1,180 carbapenem-resistant enterobacteriaceae strains were obtained from patients admitted to the 20 sentinel hospitals in eight cities. Strains positive for bla NDM-5 were detected using the Vitek 2 compact system, 16S rRNA gene sequencing, PCR, the S1-pulsed-field gel electrophoresis assay, and Southern blot hybridization. The horizontal-transfer capability of the bla NDM gene was assessed by filter mating with a standard E. coli J53 azide-resistant strain as the recipient. Genotyping, susceptibility testing, and whole genome sequencing were performed. Results: Seven strains of bla NDM-5 -positive E.coli was detected in 1180 clinical strains from different regions in China. The bla NDM-5 -carrying strains showed resistance to multiple tested antibiotics and belonged to two widespread sequence types, ST167 and ST405. Antimicrobial resistance genes including bla CTX-M , bla OXA , bla CMY , and two novel bla TEM variants ( bla TEM-230 and bla TEM-231 ) were also identified. Southern blotting located the bla NDM-5 gene on 46-kb IncX3 plasmids in all isolates, which showed only two single nucleotide differences between EJN003 and the other strains. Conclusions: This study further confirms the increasing occurrence of bla NDM-5 -carrying IncX3 plasmids and the dissemination of carbapenem resistance in E. coli isolates via the plasmid from different parts in China, which warrants stringent surveillance and control measures.

目的:了解新冠肺炎疫情常态化防控下参加某大型军事活动的后勤保障人员防疫卫生知识、态度、行为(KAP)的状况及影响因素,为进一步做好疫情防控知识培训提供参考.方法:采用整群抽样的方法,对某大型军事活动的后勤保障人员269例进行防疫卫生KAP问卷调查,并对调查结果进行统计分析.结果:(1)后勤保障人员新冠肺炎疫情防控知识的总体知晓率为64.20％,仅正确佩戴口罩一项的知晓率达到94.80％,预防措施、正确消毒、体温监测等宣贯较好的知识知晓率均超过69.00％,而传染源、临床表现、心理调节等相对专业的知识知晓率则不足40.00％,其中临床表现为35.32％,心理调节为30.48％,传染源的知晓率仅为23.79％.(2)后勤保障人员整体防控态度较为积极,95.91％同意"坚决履行防控责任".(3)11项疫情防控相关行为持有率整体较高,其中"从不采购或烹饪野生动物""在工作场所咳嗽或打喷嚏时遮掩口鼻""每次外出佩戴口罩"三种行为的持有率均超过93.00％;而执行"七步洗手法"行为持有率最低,为76.21％.(4)对不同类别人员的分析显示,工作岗位、受教育情况、年龄大小和工作年限是卫生知识、行为主要的影响因素,低学历、年龄较大、工作年限较长的后勤保障人员新冠防控知识、行为得分低于相应的其他人员.接触风险较高的餐饮、客房保障人员的新冠防控知识、行为得分低于工程维护、勤务人员.结论:针对调查情况,建议提高培训的针对性和实用性,强化重点人员培训以提升整体保障水平.

In this work, the pyrolysis characteristics of a low-toxic N,N-dimethylacrylamide (DMAA) gel polymer was investigated through nonisothermal thermogravimetry (TG) and TG-FTIR analyses. Moreover, the thermal debinding kinetics of gelcast SiAlON ceramic parts was studied through three different kinetic models: the Coats-Redfern (C-R) method, distributed activation energy model (DAEM) and three-Gaussian-DAEM-reaction model (3-DAEM). The rationality and adaptability of the three models to the thermal debinding kinetics study were analyzed by comparison with experimental data. The results showed that three mass loss zones were observed in the temperature ranges of 100-320 °C, 320-520 °C and 520-600 °C, respectively, and the main pyrolysis gas products were CO2, H2O and CH4. The conversion rate (α) curves calculated by 3-DAEM were more consistent with the experimental values than those calculated with the C-R and DAEM methods. The fitting quality parameter (Fit%) was less than 2.63%, and the reaction rate (dα/dT) curves calculated by 3-DAEM were bimodal distribution curves, which were in good agreement with the experimental results. The kinetic parameters (E 0,i , k 0,i and σ i ) of the global thermal debinding process calculated by 3-DAEM were 116.00-145.79 kJ mol-1, 1.10 × 109 s-1 and 1.67-43.25 kJ mol-1, respectively. It is anticipated that the study achievements can be used to help predict the thermal debinding behavior and design a reasonable debinding technology for the gelcasting of ceramic parts.

Thermal debinding is an important step in a gelcasting process, and the proper selection of the debinding technique is crucial for the quality of a green body. In this work, the pyrolysis characteristics of an N,N-dimethylacrylamide/N,N'-methylenebisacrylamide gel system in a thermal debinding process of a gelcast SiAlON green body were investigated through nonisothermal thermogravimetric analysis and a thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy analysis. In addition, the pyrolysis kinetics of the thermal debinding process of the gelcast SiAlON green body were described by using a three-parallel-distributed activation energy model. The results showed that the conversion (alpha) and reaction rate (da/dT) curves predicted by the kinetic model agreed well with the experimental data. The kinetic parameters (E-0.i, k(0.i), and sigma(i)) of the global thermal debinding process were 116.0-158.0 kJ/mol, 9.31 x 10(8) s(-1) and 2.19-20.52 kJ/mol, respectively. Finally, a solid-fluid-thermal-mechanical coupling numerical model of the thermal debinding process was established through finite element methods on the basis of theories of the porous medium seepage and thermodynamics. The distributions of the residual content of the gel polymer, the temperature, the pressure, and the stress in the green body throughout the entire thermal debinding process were evaluated using this model. It was shown that a high heating rate leads to a high temperature gradient and von Mises stress inside the green body. Moreover, a reasonable debinding technique was proposed to effectively prevent and eliminate defects caused by excessive stress or a temperature gradient inside the green body. In a given DMAA/MBAM gel system, the strongest stress peak can be effectively eliminated by holding at 310 degrees C for no less than 2 h at a heating rate of 1 degrees C/min. This work aims to provide a theoretical basis for studying thermal debinding kinetics and optimizing debinding techniques for the gelcasting of various materials.

目的 评价3种常用化学消毒剂对脂环酸芽孢杆菌芽孢的杀灭效果.方法 采用悬液定量杀菌试验方法,对3种化学消毒剂杀灭脂环酸芽孢杆菌芽孢的效果进行观察.结果 有效氯浓度为5000 mg/L的次氯酸钠作用30 min,对脂环酸芽孢杆菌芽孢的杀灭对数值为2.94;二氧化氯浓度为40 mg/L作用1.5 min,对脂环酸芽孢杆菌芽孢的杀灭对数值为>5.00;过氧化氢浓度为30 g/L作用15 min,对脂环酸芽孢杆菌芽孢的杀灭对数值为>5.00.结论 本研究中的3种化学消毒剂,在设计条件下以二氧化氯杀灭脂环酸芽孢杆菌芽孢的效果最好.

The acute inflammatory lung injury is an important cause of death due to influenza A virus (IAV) infection. Insulin-like growth factor 1 (IGF1) played an important role in the regulation of inflammation in the immune system. To investigate the role of IGF1 in IAV-mediated acute inflammatory lung injury, the expression of IGF1 and inflammatory cytokines was tested after IAV A/Puerto Rico/8/1934 (H1N1; abbreviated as PR8) infection in A549 cells. Then, a BALB/c mouse model of PR8 infection was established. On days 3, 5, 7, and 9 post-infection, the mice lung tissue was collected to detect the expression changes in IGF1 mRNA and protein. The mice were divided into four groups: (1) PBS (abbreviation of phosphate buffered saline); (2) PR8 + PBS; (3) PR8 + IGF1; and (4) PR8 + PPP (abbreviation of picropodophyllin, the IGF1 receptor inhibitor). The body weight and survival rate of the mice were monitored daily, and the clinical symptoms of the mice were recorded. On day 5 post-infection, the mice were sacrificed to obtain the serum and lung tissues. The expression of inflammatory cytokines in the serum was detected by enzyme linked immunosorbent assay; lung injury was observed by hematoxylin-eosin staining; the viral proliferation in the lung was detected by real-time quantitative PCR; and the protein expression of the main molecules in the phosphatidylinositol-3-kinases/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase (MAPK) signaling pathways was detected by Western blot. It was found that IGF1 expression is upregulated in A549 cells and BALB/c mice infected with PR8, whereas IGF1 regulated the expression of inflammatory cytokines induced by PR8 infection. Overexpression of IGF1 aggravated the IAV-mediated inflammatory response, whereas the inhibition of IGF1 receptor reduced such inflammatory response. The phosphorylation of IGF1 receptor triggered the PI3K/AKT and MAPK signaling pathways to induce an inflammatory response after IAV infection. Therefore, IGF1 plays an important immune function in IAV-mediated acute inflammatory lung injury. IGF1 may provide a therapeutic target for humans in response to an influenza outbreak, and inhibition of IGF1 or IGF1 receptor may represent a novel approach to influenza treatment.

目的 了解我国北方地区黑龙江、北京、内蒙古和西藏4省份自备井水质状况,为加强自备井水的卫生监督和管理提供依据.方法 对我国北方地区4省份233个自备井,按照《生活饮用水标准检验方法》(GB/T 5750-2006)进行采样,检测感官性状、化学、细菌学和毒理学共27项水质指标,并进行卫生学评价.结果 我国北方地区4省份自备井水总不合格率为52.36％.4省份的水质差异性大.黑龙江自备井的超标指标主要是浑浊度、肉眼可见物、锰、砷和硝酸盐;北京自备井的超标指标主要是硝酸盐和微生物;内蒙古自备井的超标指标主要是硫酸盐和氟化物;西藏自备井的超标指标则是锌和氯化物.结论 根据地域区别和水质特征,加强自备井水源管理、消毒和水质净化,保证居民饮用水安全.