Reductive leaching of manganese oxide ores using waste tea as reductant in sulfuric acid solution

Manganese oxide ores from Gabon and Xiangxi were leached with waste tea as reductant in dilute sulfuric acid solution. The effects of waste tea dosage, concentration of sulfuric acid, liquid-to-solid ratio, leaching temperature and reaction time on leaching process were explored. The leaching efficiency of Gabonese manganese oxide ore reached almost 100% under the optimal condition which was determined as follows： manganese oxide ore to waste tea mass ratio of 10：1, sulfuric acid concentration of 2.5 molFL, liquid-to-solid ratio of 7.5：1, leaching temperature of 368 K, time of 8 h. The leaching efficiency of Xiangxi manganese oxide ore reached 99.8% under the optimal condition which was determined as follows： manganese oxide ore to waste tea mass ratio of 10：1, sulfuric acid concentration of 1.7 mol/L, liquid-to-solid ratio of 7.5：1, leaching temperature of 368 K, time of 8 h. The leaching process followed the internal diffusion controlled kinetic model, and the apparent activation energies of Gabonese manganese oxide ore and Xiangxi manganese oxide ore were calculated to be 38.2 kJ/mol and 20.4 kJ/mol, respectively. The morphological changes and mineralogical forms of the ore before and after the chemical treatment were discussed with the support of XRD analysis and SEM analysis.

The Business English Teaching in Vocational Technology College

The vocational business English teaching should adapt to the requirments of enterprise, focus on the practical application of business English, and empolder a teaching mode with vocational characteristics.

Using Games for Vocabulary Teaching and Learning

Vocabulary acquisition is increasingly viewed as crucial to language acquisition.Meanwhile,learning vocabulary is often perceived as a tedious and laborious process.Chinese students usually feel bored in vocabulary lessons because they have not changed their learning habits,such as writing word on paper,trying to learn by heart.To help students find vocabulary lessons more interesting,we can use games.This paper analyses the traditional method of teaching vocabulary is not effective,whereas there are some advantages of using games,such as,games bring in fun,games are motivating and create context for language use and then gives two examples of applying games in my vocabulary teaching.Students prefer games and puzzles.Games motivate and entertain students but also help them memorize and recall the material easily.The conclusion is that learning vocabulary through the games is an effective and interesting means which should be used in any classrooms.

TEAD1/TEAD4基因多态性与非贲门胃癌变关系的研究

目的探讨TEA转录因子1(TEAD1)基因单核苷酸多态性(SNP)rs2304733、TEA转录因子4(TEAD4)SNPrs7135838和rs1990330与非贲门胃癌变发病风险的关系。方法采用酶联免疫吸附测定法(ELISA)检测正常对照组血清样本中抗幽门螺杆菌(Hp)的特异性抗体,根据抗体滴度将470例正常对照组分为Hp感染阴性组(n=223)和阳性组(n=247)。在450例非贲门胃癌病例组和470例对照组中,采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)技术对各SNP位点进行基因分型,采用非条件性Logistic回归评估各SNP位点与非贲门胃癌变发病风险的关系。结果TEAD1、TEAD4各SNP位点均与Hp感染没有关联;TEAD1 rs2304733与非贲门胃癌的发病风险相关,与携带TT基因型者相比,携带CT基因型及CC基因型者均增加了非贲门胃癌的发病风险(CTvsTT:OR=2.321,95%CI:1.690~3.188;CCvsTT:OR=5.140,95%CI:1.080~24.463);TEAD4 rs1990330与非贲门胃癌发病风险相关,与携带GG基因型者相比,携带GT基因型者增加了非贲门胃癌的发病风险(OR=2.405,95%CI:1.480~3.908);TEAD4 rs7135838与非贲门胃癌的发病风险无关联;TEAD1rs2304733、TEAD4 rs7135838以及rs1990330对非贲门胃癌发病风险存在交互作用(P<0.05)。结论在包头地区汉族人群中,TEAD1 rs2304733、TEAD4 rs1990330在Hp感染中不起主要作用,在非贲门胃癌发病风险中可能起一定作用;TEAD4 rs7135838在Hp感染以及非贲门胃癌发病风险中可能均不起主要作用;TEAD1 rs2304733、TEAD4 rs1990330对非贲门胃癌发病风险的协同效应最强,为最佳交互模型。

CircFoxo3调节miR-130a-5p/TEAD1轴对心力衰竭大鼠心肌细胞凋亡影响的实验研究

目的探讨环状RNA叉头框蛋白O3(CircFoxo3)调节miR-130a-5p/TEA域转录因子1(TEAD1)轴对心力衰竭(HF)大鼠心肌细胞凋亡的影响。方法将SD大鼠分为对照组、HF组、si-NC组、si-CircFoxo3组、agomir NC组、miR-130a-5p agomir组、si-CircFoxo3+antagomir NC组、si-CircFoxo3+miR-130a-5p antagomir组,每组18只。除对照组外,其他组大鼠均通过腹腔注射盐酸阿霉素的方法构建HF大鼠模型。建模成功后进行药物处理,每3 d给药一次,持续3周。应用反转录实时荧光定量聚合酶链式反应(qRT-PCR)法检测心肌组织中CircFoxo3、miR-130a-5p表达水平。应用彩色多普勒超声仪检测大鼠左室收缩末期内径(LVESD)、左室舒张末期内径(LVEDD)、左室射血分数(LVEF)水平。采用酶联免疫吸附试验(ELISA)法检测大鼠血清人基质裂解素2(ST_(2))、N端脑钠肽前体(NT-pro BNP)水平。应用HE染色、Masson染色检测大鼠心肌组织病理变化和心肌纤维化情况。通过TUNEL染色检测心肌细胞凋亡水平。应用Western blot法检测大鼠心肌组织TEA域转录因子1(TEAD1)、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)、裂解的天冬氨酸特异性半胱氨酸蛋白酶-3(cleaved caspase-3)蛋白表达水平。通过双荧光素酶报告基因实验验证CircFoxo3与miR-130a-5p、miR-130a-5p与TEAD1的关系。结果与对照组比较,HF组大鼠心肌组织病理损伤、心肌纤维化严重,LVESD、LVEDD水平上升,心肌组织CircFoxo3及TEAD1、Bax、cleaved caspase-3蛋白表达水平升高,血清ST_(2)、NT-pro BNP水平升高,心肌细胞凋亡率升高,LVEF、miR-130a-5p和Bcl-2蛋白水平降低,差异有统计学意义(P<0.05)。与HF组、si-NC组比较,si-CircFoxo3组大鼠心肌组织病理损伤减轻,LVESD、LVEDD水平降低,心肌组织CircFoxo3及TEAD1、Bax、cleaved caspase-3蛋白表达水平降低,血清ST_(2)、NT-pro BNP水平降低,心肌细胞凋亡率降低,LVEF、miR-130a-5p及Bcl-2蛋白水平升高,差异有统计学意义(P<0.05)。与HF组、agomir NC组比较,miR-130a-5p agomir组大鼠心肌组织病理损伤、心肌纤维化有所改善,LVESD、LVEDD水平降低,心肌组织TEAD1、Bax、cleaved caspase-3蛋白表达水平降低,血清ST_(2)、NT-pro BNP水平降低,心肌细胞凋亡率降低,LVEF、miR-130a-5p及Bcl-2蛋白水平升高,差异有统计学意义(P<0.05)。与si-CircFoxo3组、si-CircFoxo3+antagomir NC组比较,si-CircFoxo3+miR-130a-5p antagomir组大鼠心肌组织病理损伤、心肌纤维化加剧,LVESD、LVEDD水平升高,心肌组织TEAD1、Bax、cleaved caspase-3蛋白表达水平升高,血清ST_(2)、NT-pro BNP水平升高,心肌细胞凋亡率升高,LVEF、miR-130a-5p、Bcl-2蛋白水平降低,差异有统计学意义(P<0.05)。CircFoxo3与miR-130a-5p、miR-130a-5p与TEAD1存在靶向关系。结论沉默CircFoxo3可能通过海绵化上调miR-130a-5p来抑制TEAD1表达,进而抑制HF大鼠心肌细胞凋亡。

Production of Cocoa Butter Replacer by Dry Fractionation, Partial Hydrogenation, Chemical and Enzymatic Interesterification of Tea Seed Oil

Production of cocoa butter replacer (CBR) from tea seed oil through common modification methods of oils (dry fractionation, partial hydrogenation, chemical and enzymatic interesterification) was evaluated. Some physico-chemical properties (iodine, saponification, acid and peroxide values) and fatty acid composition (FAC) of modified samples were analyzed and compared with a reference cocoa butter (CB). Solid and liquid fractions for large amounts of unsaturated fatty acids (approx. 80%) and thereby lower iodine values (81 - 85 gI2/100g) than that of CB (37% and 34 gI2/100 g, respectively), are not suitable as CBR. Among all ratios of chemically and enzaymatically interesterified oil blends (20%, 25% and 30% of hydrogenated tea seed oil with 80%, 75% and 70% of tea seed oil/liquid fraction/solid fraction), the samples with ratio of 30:70 from both chemical and enzymatic interesterification had FAC and iodine value closer to that of CB. A comparision between chemically and enzymatically interesterified samples (CISs and EISs, respectively), in terms of solid fat content (SFC) indicated that although the SFC values in EIS were much lower than that of CB, but the thermal behavior of this sample is comprable to CB at 20℃- 30℃ (sharp melting point of CB).

Characterization of mulberry leaf instant tea and evaluation of its hypolipidemia effect via regulation of intestinal microbiota

The purpose of this study was to characterize mulberry leaf instant tea(MLIT)powder prepared from the'Longsang No.1'(Morus abla L.cv.Longsang 1)mulberry leaves in Heilongjiang Province(China)and assess its obesity-preventing/relieving effects.A total of 174 compounds including quercetin,chlorogenic acid,1-deoxyecomycin(1-DNJ)related to antihyperlipidemia effects were identified from the MLIT powder.MLIT treatment reversed the Lee's index,fat coefficient,and serum biochemical parameters in both the obesity relieving and obesity preventing mice fed with high-fat diet.In the obesity relieving experiment,the relative abundance of Desulfovibrio in mouse feces decreased after both 0.5%and 1%MLIT treatments.In obesity preventing experiments,mouse with different amount of MLIT treatments showed increased relative abundance of Akkermansia,Bifidobacterium and Lactobacillus,while Deferribacteres,Desulfobacterota decreased.The beneficial bacteria in the intestinal tract of mice treated with MLIT increased.This study proved that MLIT had antihyperlipidemia potential via modulating intestinal microbiota in mice.

Antibacterial mechanism of kojic acid and tea polyphenols against Escherichia coli O157:H7 through transcriptomic analysis

Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry.

How to Approach the Teaching of Politeness in Foreign Language

As communicative competence has achieved ascendancy in the goals of foreign and second language pedagogy,attention to function aspects of language identified as speech acts has also increased.This paper aims to explore how the teaching of communicative competence, especially the teaching of politeness can be approached by teaching materials.What kind of politeness strategies appear,how they are presented appropriately and whether they are effective or not are considered here.It focuses on the notion of politeness with special reference to the speech acts of requesting by means of analyzing some activities in the textbooks.

The Effective Ways to Integrate Excellent Traditional Culture Into College English Teaching—Taking Tea Culture as an Example

Further strengthening the integration of traditional culture and college English teaching has a great impact on the cultivation of students’comprehensive moral literacy and values.At the same time,the ingenious integration of tea culture into college English teaching not only helps to enhance students’cultural self-confidence,but also helps to effectively carry forward the excellent traditional Chinese culture.Therefore,according to the tea culture,this paper describes in detail the practical significance of integrating tea culture into college English education,and then puts forward that tea culture has become an effective way of college English teaching,hoping to bring the students’English learning ability to a certain extent.At the same time,it can further promote and develop China’s tea culture.

Effect of a Commercial Extract of Green Tea and a Pure Catechin on Two Veillonella strains

The catechin Epigallocatechin-3-O-Gallate (EGCG) which is found in of Green Tea extracts (GTE), displays a variety of microbicidal properties. It is largely believed that EGCG inhibits the growth of cariogenic and periodontopathic bacteria. Objective: In this paper we compared the inhibitory activity of EGCG and a commercial GTE on the growth of Veillonella parvula. Chlorhexidine was used as positive control. Methodology: V. parvula ATCC 10790 and a clinical isolate obtained from a periodontal disease patient were cultured in the presence of EGCG or a commercial GTE, and the measurements of bacterial growth inhibition were compared to the values obtained with 0.12 and 0.2% chlorhexidine. Results: Chlorhexidine inhibited bacterial growth, however in contrast to a previous report, neither EGCG nor the GTE showed any effect on bacterial growth. Conclusions: The data show and confirm that chlorhexidine is a growth inhibitor of V. parvula while EGCG and GTE do not display such effect.

A Study on Spoken-English Teaching in Country Schools

Spoken English teaching plays a significant role in English teaching.It reflects the students'ability of practical English usage.However,the state of spoken English teaching in the country schools can't make us content and it falls behind the state of cities.It is urgent to pay attention to this problem and try to find good ways to settle it.Many available approaches in spoken English teaching will be found in this paper.These ideas,perhaps,can stimulate people to think of more creative methods to teach spoken-English and improve the students'ability of practical English usage in country schools.

Training of English Learning Strategy: Discussions Based on a Plan of Strategy Teaching in the Classroom of Senior School

Training of English learning strategy has become an important part in English teaching, but in the practice of the eductional activities, it does not be treated seriously. This paper tries to design a teaching plan to instruct some strategies and discuss the practical functions and meanings of learning strategy in English teaching by analyzing them.

Duplicated chalcone synthase(CHS)genes modulate flavonoid production in tea plants in response to light stress

In tea plants,the abundant flavonoid compounds are responsible for the health benefits for the human body and define the astringent flavor profile.While the downstream mechanisms of flavonoid biosynthesis have been extensively studied,the role of chalcone synthase(CHS)in this secondary metabolic process in tea plants remains less clear.In this study,we compared the evolutionary profile of the flavonoid metabolism pathway and discovered that gene duplication of CHS occurred in tea plants.We identified three CsCHS genes,along with a CsCHS-like gene,as potential candidates for further functional investigation.Unlike the CsCHS-like gene,the CsCHS genes effectively restored flavonoid production in Arabidopsis chs-mutants.Additionally,CsCHS transgenic tobacco plants exhibited higher flavonoid compound accumulation compared to their wild-type counterparts.Most notably,our examination of promoter and gene expression levels for the selected CHS genes revealed distinct responses to UV-B stress in tea plants.Our findings suggest that environmental factors such as UV-B exposure could have been the key drivers behind the gene duplication events in CHS.

Carbonic anhydrase 2 mediates anti-obesity effects of black tea as thermogenic activator

Obesity is a metabolic disorder due to over-accumulation of adipose tissue and ultimately becomes a“disease”.Brown adipose tissue(BAT)thermogenesis and white adipose tissue(WAT)browning emerge as a potential strategy of anti-obesity by dissipating energy as heat.However,drugs based on adipose tissue thermogenesis have not been successfully approved yet.In current study,we found that black tea extract(BTE)obtained by patentauthorized manufacturing process prevented body weight gain as novel thermogenic activator with reduction of adiposity,improvement of adipose distribution,and glucose metabolism improvement in diet-induced obesity mice.Mechanismly,anti-obesity effect of BTE depends on promoting BAT thermogenesis and WAT browning with upregulation of uncoupling protein 1(UCP1),especially visceral adipose tissue(VAT)with browning resistance.Specifically,utilizing in silico approach of network pharmacology and molecular docking,we identified carbonic anhydrase 2(CA2)in nitrogen metabolism as anti-obesity target of BTE and further elucidated that protein kinase B(AKT)signaling pathway linked CA2 and UCP1.Meanwhile gut microbiota regulation may prompt the CA2-dependent thermogenesis activation.Our findings demonstrated anti-obesity effect of BTE as thermogenic activator through CA2-mediated BAT thermogenesis and WAT browning via CA2-AKT-UCP1 signaling pathway,which could be developed as promising anti-obesity agent with good safety and efficacy.

A Survey of Listening——Obstacles in College English Teaching

Listening is an essential component of communication in human life. It's also a basic skill in English learning. But for most college students, among listening, speaking, reading and writing skills, listening is the most difficult one. This paper was designed to survey the English listening obstacles in college and focuses on the categories of the listening obstacles in English teaching in college. From the paper, the readers can have a general idea about English listening obstacles and get some useful advices from the participants.

Correlation and Pathway Analysis of the Carbon,Nitrogen,and Phosphorus in Soil-Microorganism-Plant with Main Quality Components of Tea(Camellia sinensis)

The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement.

Pattern of Eye Diseases among Tea Workers

Background: Bangladesh’s tea industry is essential to the country’s economic expansion. Since tea workers in Bangladesh are marginalized within our community, they have limited access to comprehensive eye care services. Productivity and well-being are cornerstones of comprehensive health care strategy. Ocular disorders are influenced by life expectancy, sociodemographic status, and the epidemiological transition. In this context, the state of ocular health and the many eye illnesses remain to be significantly addressed. Purpose: To evaluate the pattern of eye diseases among tea workers in a tea estate of Bangladesh. Methods: This cross-sectional observational study was carried out in Halda Valley Tea Estate, Nazirhat, Fatickchari, Chattogram, Bangladesh, under the supervision of the Department of Community Ophthalmology, BSMMU, following ethical clearance and approval by the IRB board of BSMMU. With informed written consent and approval from the authority of the tea estate, a total of 110 tea workers were recruited. Socio-demographic characteristics, ocular findings, and patterns of eye diseases were determined and recorded. Results: The mean age of the study participants was 39.60 ± 11.63 years. The maximum (58.1%) study participants were 31 - 50 years old, female (64.5%), illiterate (82.7%), and tribal (71.8%) indigenes. Eye diseases were found in 94.5% of workers. Presbyopia (28.2%), cataracts (27.3%), and refractive error (26.4%) were the most common. Tea workers with eye diseases were significantly older than those who did not have any eye diseases (40.20 ± 11.57 vs. 29.17 ± 7.31 years, p Conclusion: A significant number of tea workers had eye diseases, of which presbyopia, cataracts, and refractive error were the most common.

Junshanyinzhen tea extract prevents obesity by regulating gut microbiota and metabolic endotoxemia in high-fat diet fed rats

Obesity is associated with gut dysbiosis and metabolic endotoxin.Junshanyinzhen tea extract(JSTE)reduced fat accumulation and body weight in obese mice.However,the effects and mechanism of JSTE in preventing obesity were unclear.Therefore,we used different doses of JSTE(75,150 and 300 mg/(kg·day))to evaluate the effect on high-fat diet(HFD)-induced rats under 8 weeks of intervention.Here,our results showed that JSTE could significantly reduce body weight gain,blood lipid levels and fat accumulation,improve fatty damage in liver tissue(P<0.05).In addition,JSTE increased the expression of intestinal tight junction proteins(P<0.05),relieved metabolic endotoxemia(P<0.05)and chronic low-grade inflammation in HFD rats.Sequencing of fecal samples showed that JSTE could effectively reverse the microbial diversity and the ratio of Firmicutes to Bacteroidetes to normal levels in HFD-fed rats.Desulfovibrioceae and Erysipelotrichaceae,which are positively related to obesity,were decreased by JSTE intervention(P<0.05).while Bifidobacteriaceae,Bacteroidaceae,Akkermansia,and Clostridium,which are negatively related to obesity,were increased.Together,these results suggested that JSTE might effectively prevent obesity by modulating gut microbiota dysbiosis,intestinal barrier dysfunction,metabolic endotoxemia and chronic low-grade infl ammation in HFD-induced rats.

On-site rapid detection of multiple pesticide residues in tea leaves by lateral flow immunoassay

The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.