Characteristics and mechanism of Ni^(2+)and Cd^(2+)adsorption by recovered perlite from agar extraction residue

Ni^(2+)and Cd^(2+)in wastewater accumulated through the ecological chain and could jeopardize human health.Adsorption of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite was an important way to solve the problem of resource utilization of solid waste from agar production.Our previous study confirmed that recovered perlite from agar extraction residue had better pore size and specific surface area than commercial perlite.However,the adsorption efficiency and adsorption mechanism of recovered perlite were the main factors limiting its adsorption application.The adsorption process of Ni^(2+)and Cd^(2+)by recovered perlite in aqueous solution was described by the pseudo-second-order kinetic equation,and the relevant adsorption mechanism was mainly chemisorption.Compared with commercial perlite,the adsorption removal rate of Ni^(2+)and Cd^(2+)by enzymatic recovered perlite could reach 92.9%and 89.2%,respectively,and were improved by 12.63%and 13.03%.Langmuir isothermal adsorption model could better describe the isothermal adsorption process of recovered perlite on heavy metal Ni^(2+)and Cd^(2+),and the relevant adsorption mechanism was mainly monolayer adsorption.The X-ray photoelectron spectroscopy(XPS)results indicated that the decrease of Si—O Si^(2+)hydroxyl coordination bond and the increase of C—Si bond might make the binding effect of recovered perlite with heavy metals stronger.The competitive adsorption of Ni^(2+)and Cd^(2+)by recovered perlite was still dominated by chemisorption and monolayer adsorption.This study was expected to provide a theoretical basis and technical support for the removal of Ni^(2+)and Cd^(2+)from wastewater using recovered perlite from seaweed residue.

Realistic Significance and Practical Exploration of Cultivating New Professional Farmers in China

Firstly, the background, ways, countermeasures, problems and realistic significance of cultivating new professional farmers in China were studied, and then the mechanism for cultivating new professional farmers was discussed based on Town S. The results show that cultivating new professional farmers can fundamentally relieve "three rural issues" existing for a long time and is of great significance to rural economic development. For instance, it can integrate rural human capital and release modern productivity, increase farmers' income and improve rural economy, increase land utilization and output per unit area, and break through the bottlenecks during agricultural development to realize agricultural modernization. According to the case study of Town S, during the process of cultivating new professional farmers, governments at all levels ought to adopt many effective measures and strengthen support to realize cultivation targets planed early.

基于电化学传感技术的土壤农药残留检测装置设计

为准确掌控农药对农业环境和作物的污染情况,快速精准的农药残留检测手段是当前的重要需求。以土壤中的啶虫脒残留为对象,提出一种基于电化学生物传感技术的新型检测方法,研究制备适用于检测土壤中啶虫脒残留含量的适体传感器,设计基于电化学传感技术的土壤农药残留检测装置,其功能包括田间土壤的样本采集、预处理及土壤啶虫脒残留含量的现场检测等。重点设计采土机构、搅拌机构和农药残留检测单元等,并对各个机构的关键设计参数进行仿真分析和计算,根据分析结果对土壤采样预处理装置的器件进行选型,确定电气控制系统的控制方案。对研制装置检测性能进行综合试验验证,土壤样本采集试验结果表明:当采集土层深度为0~5 cm时,土壤样本质量相对标准偏差≤2%,柱状土壤样本不会黏附在合金钻头表面。与商用电化学工作站对比试验表明,所测啶虫脒浓度值的平均误差仅为0.7%,验证所研制装置检测的精准性。为农药残留快速检测提供新的检测方法和技术支撑。

基于双转子连续混炼挤出机的聚乳酸/淀粉共混物的制备及性能

以淀粉和聚乳酸(PLA)为原料、甘油为增塑剂,采用双转子连续混炼挤出机通过熔融共混法制备了PLA/淀粉共混物,研究不同转子转速和甘油含量下,共混物的微观结构、流变性能、结晶性能和力学性能,得到剪切作用及增塑剂含量对共混物两相相容性的影响。对共混物的扫描电镜照片、红外光谱图以及动态频率扫描曲线进行分析。结果表明,适当提高转子转速及甘油含量有利于提高淀粉的塑化程度,改善淀粉与PLA之间的相容性。差示扫描量热分析曲线表明,共混物的结晶度随着甘油含量的提高而降低。当甘油质量分数为20%、转速为300 r/min时,淀粉分散相与PLA基体的相容性最好,共混物具有良好的力学性能,拉伸强度达到25.1 MPa、弯曲强度达到33.1 MPa。

Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated, regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition： concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 ℃, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 μg/g and 1516.0 μg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.

Isolation of a novel characterized Issatchenkia terricola from red raspberry fruits on the degradation of citric acid and enrichment of flavonoid and volatile profiles in fermented red raspberry juice

High content of citric acid in red raspberry juice leads to poor sensory experience. This study developed a feasible method to degrade citric acid in red raspberry juice using a novel characterized Issatchenkia terricola WJL-G4 isolated from red raspberry fruits. I. terricola WJL-G4 exhibited a potent capability of reducing the citric acid contents from(22.8 ± 0.08) g/L to(6.2 ± 0.02) g/L within 36 h fermentation, then completely depleted after 48 h. Furthermore, the contents of phenolic compound, including neochlorogenic acid, p-coumaric acid, raspberry ketone, and rutin significantly increased after 36 h fermentation. Fermentation increased total flavonoid contents in red raspberry juice, compared to that in control group. Volatile profiles exhibited to be enriched after fermentation, which contributed to the improvement of the juice taste. Our findings showed that I. terricola WJL-G4 can be applied in deacidification, enrichment of flavonoid compounds and volatile profiles in fermented red raspberry juice..

Analysis of volatile components in a Chinese fish sauce,Fuzhou Yulu, by gas chromatography-mass spectrometry

Volatile components of Fuzhou Yulu, a Chinese fish sauce, were analyzed by gas chromatography-mass spectrometry （GC-MS）, and two pretreatment methods, i.e., purge and trap （P＆T） GC-MS and ethyl acetate extraction followed by GC-MS, were compared. P＆T-GC-MS method determined 12 components, including sulfur-containing constituents （such as dimethyl disulfide）, nitrogen-containing constituents （such as pyrazine derivatives）, aldehydes and ketones. Ethyl acetate extraction fol- lowed by GC-MS method detected 10 components, which were mainly volatile organic acids （such as benzenepropanoic acid） and esters. Neither of the two methods detected alcohols or trimethylamine. This study offers an important reference to determine volatile flavor components of traditional fish sauce through modem analysis methods.

Infliximab trough level combined with inflammatory biomarkers predict long-term endoscopic outcomes in Crohn’s disease under infliximab therapy

BACKGROUND Infliximab trough level(ITL)severely affects therapeutic outcomes of Crohn’s disease(CD)patients under infliximab(IFX).Recently,frontier research has focused on identifying ITL based on different therapeutic targets.Although previous studies have elaborated clinical value of ITL monitoring on short-term outcomes in CD patients during therapy,studies contraposing the predictive value of ITL on long-term endoscopic outcomes in CD patients are still scarce domestically and overseas.AIM To explore the predictive value of ITL in combination with inflammatory biomarkers on long-term endoscopic outcomes in CD with clinical remission during IFX maintenance therapy.METHODS CD patients with endoscopic remission under long-term IFX maintenance therapy in the First Affiliated Hospital of Zhejiang Chinese Medicine University from January 2012 to December 2020 were collected.ITL and inflammatory biomarkers were continuously monitored during the therapy.The Step I study was conducted from weeks 14 to 54 of IFX treatment.The Step II study was conducted from weeks 54 to 108 of IFX treatment.Endoscopic outcomes were defined as endoscopic activity(Crohn’s disease endoscopic index of severity score>2 points or Rutgeerts score>i1)and endoscopic remission(Crohn’s disease endoscopic index of severity score≤2 points or Rutgeerts≤i1).Endoscopic relapse free survival was defined as endoscopic remission at the beginning of the study stage and maintaining endoscopic remission during the study stage.RESULTS At week 14,low ITL[odds ratio(OR)=0.666,95%confidence interval(CI):0.514-0.862,P<0.01]and high fecal calprotectin(FCP)level(OR=1.002,95%CI:1.001-1.004,P<0.01)increased the risk of endoscopic activity at week 54.At week 54,low ITL(OR=0.466,95%CI:0.247-0.877,P<0.01)and high C-reactive protein(CRP)level(OR=1.590,95%CI:1.007-2.510,P<0.01)increased the risk of endoscopic activity at week 108.At week 14,ITL≤5.60μg/mL[area under the curve(AUC)=0.83,95%CI:0.73-0.90,P<0.001]and FCP>238μg/g(AUC=0.82,95%CI:0.72-0.89,P<0.001)moderately predicted endoscopic activity at week 54.ITL≤5.60μg/mL in combination with FCP>238μg/g indicated 82.0%possibility of endoscopic activity.At week 54,ITL≤2.10μg/mL(AUC=0.85,95%CI:0.72-0.93,P<0.001)and CRP>3.00 mg/L(AUC=0.73,95%CI:0.60-0.84,P=0.012)moderately predicted moderate endoscopic activity at week 108.ITL≤2.10μg/mL in combination with CRP>3.00 mg/L indicated 100.0%possibility of endoscopic activity.From weeks 14 to 54 of IFX treatment,patients with ITL>5.60μg/mL had higher rate of endoscopic relapse free survival than those with ITL≤5.60μg/mL(95.83%vs 46.67%).From weeks 54 to 108 of IFX treatment,patients with ITL>2.10μg/mL had higher rate of endoscopic survival free relapsed rate than those with ITL≤2.10μg/mL(92.68%vs 30.77%).CONCLUSION Combination of ITL,CRP,and FCP contribute to long-term endoscopic prognosis monitoring.During IFX maintenance treatment,low ITL,high CRP level,and high FCP level were independent risk factors of CD patients with clinical remission in adverse endoscopy outcomes within 1-year follow-up.

Overexpression and characterization of a thermostable β-agarase producing neoagarotetraose from a marine isolate Microbulbifer sp.AG1

An agarase gene containing 1 302 bp was cloned from Microbulbifer sp. AG1. It encoded a mature protein of 413 amino acids plus a 20-residue signal peptide. The recombinant enzyme without the signal peptide was expressed and purified from Escherichia coli BL21(DE3). When agarose was used as a substrate, the optimal temperature and pH for the enzyme were 60℃ and 7.5, respectively. The recombinant agarase showed excellent thermostability with 67% and 19% of residual activities after incubation at 50℃ and 60℃ for 1 h, respectively.Except SDS, the recombinant agarase had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. Thin layer chromatography analysis and enzyme assay using p-nitrophenyl-α/β-Dgalactopyranoside revealed that the recombinant agarase was a β-agarase that degraded agarose into neoagarotetraose as the main end product. The enzymatic hydrolysis products with different degree of polymerization exhibited the antioxidant activities.

Substitution of His260 residue alters the thermostability of Pseudoalteromonas carrageenovora arylsulfatase

This study aimed to improve the thermostability of arylsulfatase from Pseudoalteromonas carrageenovora. A library of P. carrageenovora arylsulfatase mutants was constructed by introducing random mutagenesis using error-prone PCR. After screening, two mutants of H260L and D84A/H260L showed enhanced thermal stability than the wild-type predecessor (WT). Site-directed mutagenesis demonstrated that only amino acid residue at Position 260 plays an important role in the thermostability of P. carrageenovora arylsulfatase. Thermal inactivation analysis showed that the half-life (t1/2) values at 55°C for H260L, H260I, H260Q, H260F and H260R were 40.6, 48.4, 30.9, 29.1 and 34.5 min, respectively, while that of WT was 9.1 min. Structure modeling demonstrated that the additional hydrogen bonds and/or optimization of surface charge-charge interactions could be responsible for the increased thermostability imparted by H260L, H260I, H260Q, H260F and H260R.

黑色素生成信号通路研究进展

黑色素生成是一种在黑色素细胞中产生黑色素的生物合成途径,涉及一系列复杂的酶催化和化学催化反应。主要有5条信号通路参与调控,其中小眼相关转录因子(Microphthalmia-associated transcription factor,MITF)是各个通路的重要靶标。此外,许多细胞因子也参与调控黑色素生成,在黑色素细胞的发育、增殖、分化、迁移过程中发挥重要作用。结合课题组研究成果,发现多金属氧酸盐可作为一种潜在的黑色素抑制剂用于切断黑色素生成途径。因此,文中对黑色素生成信号通路作用机制进行综述,并简单介绍已报道的相关通路调控因子,以期有助于多金属氧酸盐在黑色素生成途径中的应用研究。

响应面法优化纤维素酶辅助从泡叶藻中提取泡叶藻聚糖的工艺

通过单因素实验研究纤维素酶辅助提取泡叶藻聚糖时液料比、酶添加量、酶解温度、酶解时间等关键因素对泡叶藻聚糖提取率的影响,并进一步采用Box-Behnken实验设计和响应面分析法优化其工艺参数.结果表明,纤维素酶辅助提取泡叶藻聚糖的优化工艺条件为液料比30 mL/g、酶浓度200 IU/mL、酶解时间2.0 h、酶解温度50℃,该条件下多糖提取率为14.65%±0.73%,与模型预测值14.75%非常接近,采用响应面法对泡叶藻聚糖提取条件进行优化合理可行.

Preparation and characterization of polyphenylene sulfide-based chelating fibers

A series of novel chelating fibers containing sulfur, nitrogen, oxygen heteroatoms were prepared via the functionalization of chloromethylated polyphenylene sulfide （CMPPS）. The structures, micromorpholo- gy and physicochemical properties of these fibrous adsorptive materials were characterized by FT-IR, elementary analysis, TG and SEM-EDS. The results show that chelating fibers had high functional group contents （3.94 mmol/g for thiourea, 3.85 mmol/g for mercapto, 5.00 mmol/g for methylamine and 6.07 mmol/g for ethylenediamine, respectively）. Owing to the unique matrix of polyphenylene sulfide fiber, these fibrous adsorbents possess excellent thermostability. This synthetic method proved a simple and efficient way for the preparation of chelating fibers.

以江蓠琼脂为原料制备生化琼脂

将江蓠琼脂粉与5种生化琼脂的理化指标进行对比,研究了羧甲基修饰制备生化琼脂的技术,利用羧甲基化反应降低江蓠琼脂的融化温度并提高透明度.结果表明,江蓠琼脂与商品生化琼脂的主要区别在于融化温度高且透明度低.反应的优化参数为氯乙酸添加量0.15 g/g,反应温度60℃.对反应液重复利用,可节省70.8%Na2SO4和57.0%NaOH.中试所制羧甲基琼脂的理化指标与小试结果一致,符合理化质量标准,比国内外生化琼脂的凝胶强度和透明度高,与Sigma A6686和028990生化琼脂无显著差异.日产1 t羧甲基化江蓠琼脂粉的原料成本为12.07万元.

Chemical constituents and ACE inhibitory activity of desert plant Suaeda physophora Pall.

Suaeda physophora Pall.is a kind of desert plant mostly growing in saline habitats in Xinjiang Uygur Autonomous Region.In order to have a better utilization of halophytes,a screening for ACE inhibitors from halophytes growing in Xinjiang was carried out.The result showed that the 70%EtOH extract and n-BuOH extract of S.physophora Pall.possessed significant ACE inhibitory activities.So we focused on its biochemical constituents firstly.One new quinazoline alkaloid,namely Suaedine(1),along with six known compounds(2–7)was isolated from the aerial parts of S.physophora Pall.The structure of the new quinazoline alkaloid was established by one-and two-dimensional nuclear magnetic resonance,optical rotation and mass spectrometry analysis.The flavonoid compounds(2–4)and phenolic compound(5)exhibited significant ACE activities.It was the first time to focus on the chemical constituents and bioactivities of this plant.

The camphor tree genome enhances the understanding of magnoliid evolution

Magnoliids represent the third largest branch of the most diverse and species-rich angiosperms,and their phylogenetic position relative to monocots and eudicots remains uncertain(Dong et al.,2021).Here,we describe the assembly of a high-quality chromosome-level genome sequence for Cinnamomum camphora(camphor),an evergreen tree belonging to Lauraceae.Genomebased phylogenetic analysis indicated possible incomplete lineage sorting(ILS)during the rapid diversification of the early diverging branches of angiosperms,which may have led to the unstable phylogenetic position of magnoliids.

Anti-inflammatory and Anti-oxidant Effects of Licorice Flavonoids on Ulcerative Colitis in Mouse Model

Licorice（Glycyrrhizae Radix or Liquiritiae Radix） is traditionally used to treat various diseases including inflammation and gastric ulcers. Licorice is rich in flavonoid compounds and possesses anti-inflammatory activities. To investigate the protective effects of licorice flavonoids（LFs） in both acetic acid-induced and dextran sulphate sodium（DSS）-induced ulcerative colitis（UC） mouse model and its underlying mechanism. Acute UC was induced by intra-rectal acetic acid（4% v/v） after pretreatment with LFs（100, 200, and 400 mg/kg, p.o.）, 0.9% saline（20 mL/kg, p.o.） or Sulfasalazine（SASP）（600 mg/kg, p.o.） for 10 d. Quantitative analysis of chemical components of LFs was also conducted by HPLC. Our results showed that pre-treatment with LFs significantly reduced the wet weight/length ratio of colon, percentage of affected area, macroscopic and histological damage scores in acid-induced UC mice. LFs also significantly decreased the oxidative stress and pro-inflammatory cytokines, upregulated nuclear factor erythroid 2-related factor 2（Nrf2） pathway and downregulated nuclear transcription factor kappa B（NF-κB） pathway. At last, LFs also showed obvious antiulcer effect on the DSS-induced UC model. The major components of LFs were licochalcone A, glabrone, licoflavone, and licoflavone B. This study demonstrates that the protective effect of LFs may at least in part be due to its anti-oxidant activity through Nrf2 pathway and anti-inflammatory activity through NF-κB pathway.

Effect of ultra-high pressure treatment on structural and functional properties of dietary fiber from pomelo fruitlets

The effects of ultra-high pressure treatment on structural and functional properties of dietary fiber from pomelo fruitlets were analyzed.The results showed that ultra-high treatment changed monosaccharide composition,increased total dietary fiber and soluble dietary fiber from pomelo fruitlets,especially at 400 MPa where soluble dietary fiber was greatly increased from 32.49%±0.23%to 41.92%±0.32%as compared to native one(p<0.05).Besides,ultra-high pressure treatment enhanced water-and oil-holding capacity,as well as swelling capacity of dietary fiber,which were related to its more porous structure and hydrophobic groups.Crystallinity and thermal stability of ultra-high pressure modified dietary fibers increased.Moreover,ultra-high pressure modified dietary fibers possessed stronger bile acid binding and pancreatic lipase inhibition capacities,suggesting its better potential in vitro hypolipidemic activity.Our findings suggested that ultra-high pressure treatment is a promising method to obtain dietary fiber with excellent functional properties,and can provide a basis for the high-value utilization of pomelo fruitlets as functional food with blood-lipid regulation.