新农科视域下“定量分析化学”的教学改革探索与实践

“定量分析化学”是农林高校相关专业学生必修的基础课,在农、林、动科、环境、食品、生物类等专业均有开设,在“新农科”建设背景下,本文针对课程学时数少和教学内容多、与“新农科”理念契合不足、教学内容和思政内容割裂、教学模式和考核方式单一、教学资源缺乏等教学痛点,从教学内容、教学设计、教学模式、教学资源、思政教育、考核方式等方面提出了对策和建议,以期为“定量分析化学”课程改革提供可借鉴的经验。

Design and assembly of a nested imaging X-ray telescope for the Hot Universe Baryon Surveyor mission

The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process.

MOMENTS AND LARGE DEVIATIONS FOR SUPERCRITICAL BRANCHING PROCESSES WITH IMMIGRATION IN RANDOM ENVIRONMENTS

Let(Z_(n))be a branching process with immigration in a random environmentξ,whereξis an independent and identically distributed sequence of random variables.We show asymptotic properties for all the moments of Z_(n) and describe the decay rates of the n-step transition probabilities.As applications,a large deviation principle for the sequence log Z_(n) is established,and related large deviations are also studied.

A study of the expression of p53 in posttransfection cells with rAdp53 gene and inhibitory activity in vitro

Objective： To investigate the inhibitory effect and IC50, （rAdp53） in colorectal cancer cells in vitro and to guide （50% inhibiting concentration） of the recombinant adenoviral p53 gene clinical practice. Methods： We evaluated the efficiency （IC50）of the rAdp53 and six kinds of anti-cancer drugs（5-fluorouracil, tegafur, mitomycin c, cisplatin, oxaliplatin, paclitaxel） in human colorectal cancer cell line-174 through the cell culture and MTT chemosensitivity assay to make sure the anti-cancer capability of rAdp53. Expression of p53 protein in transfection cells of colorectal cancer line-174 with rAdp53 was evaluated by immunohistochemical staining. Results： The rAdp53 is a dose-and time-dependent anti-cancer drug, its IC50 is 5.73×10^11 VP/ml, but its effect was not obvious when compared with other anti-cancer drugs. In control group, the immunohistochemistry stain was negative. However, rAd-p53 of five different concentrations were all positive in infected colorectal cancer cells with rAd-p53 and the earliest positive result would present 24 hours after infection. Conclusion： The rAdp53 has good anti-cancer efficacy is colorectal cancer cell line-174 in vitro. But its anti-cancer efficacy was less than those of the classical chemical medicine mitomycin c, 5-fluorouracil and cisplatin etc., when it was used alone.

Research of Adsorption and Desorption Characteristics of Cu and Pb in Typical Paddy Soils in Jiangxi Province

[Objective] This study was conducted to investigate the adsorption and desorption characteristics of Cu and Pb in typical paddy soils in Jiangxi Province. [Method] Two kinds of typical paddy soils （Gley type, Waterloggogenic type） in Jiangxi Province were chosen as test materials. The single and competitive adsorption behaviors of Cu and Pb in paddy soils were investigated with batch equilibrium method, and the environmental risk under coexistence of Cu and Pb in these soils was estimated with distribution coefficient. The results showed that under equal proportion, the adsorption affinity of Pb was greater than that of Cu in the two paddy soils, and the adsorption capacities in waterloggogenic paddy soil （WPS） were significantly higher than those in gley paddy soil （GTPS）, but the desorption capacities of Cu were greater than those of Pb in the two paddy soils, and the desorption capacities in GTPS were significantly higher than those in the WPS. The adsorption capacities of Cu and Pb ions under competitive condition were obviously lower than those in single system, while the desorption rates significantly increased. The potential environmental risk of Cu pollution was greater than that of Pb in paddy soils, and their environmental risk decreased with the increase of pH, but increased significantly under coexistence of lead and copper. [Conclusion] This research suggests that when Cu and Pb ions coexist in the paddy soils, compared with lead pollution, we should pay attention to the pollution of Cu.

Comparative Study on the Efficacies of 11 Chemical Agents against Taro Soft Rot Caused by Pectobacterium aroidearum

[Objective]The paper was to screen the effective agents for effectively controlling the occurrence and prevalence of taro soft rot.[Method]The fungicidal effects of 11 fungicides on taro soft rot were determined by inhibition zone method.[Result]0.3%Tetramycin,25%bromothalonil,3%Zhongshengmycin and 30%zinc thiazole had better antifungal effect on Pectobacterium aroidearum at recommended concentration.The indoor toxicity of four fungicides showed that the EC50 of 0.3%tetramycin AS was the smallest of 0.6μg/mL,indicating that tetramycin had the largest toxicity and the best inhibitory effect against P.aroidearum;followed by 25%bromothalonil EC and 3%Zhongshengmycin WP,with the EC_(50) of 2.57 and 97.72μg/mL,respectively;the inhibitory effect of 30%zinc thiazole SC against P.aroidearum was the poorest.[Conclusion]The study provides a reference for screening out new and efficient chemical agents against taro soft rot.

VEGF-C/VEGFR-3/iNOS Signaling in Osteosarcoma MG63 Cells Mediates Stimulatory Effects on Human Umbilical Vein Endothelial Cell Proliferation

Objectives To assess the effects of vascular endothelial growth factor-C(VEGF-C)/vascular endothelial growth factor receptor-3(VEGFR-3)signaling on nitric oxide(NO)production and inducible nitric oxide synthase(iNOS)expression in human osteosarcoma MG63 cells and the subsequent impact on the proliferation of human umbilical vein endothelial cells(HUVECs).Methods MG63 cells were treated with VEGF-C alone(VEGF-C group),VEGF-C+iNOS inhibitor aminoguanidine(AG;AG group),and VEGF-C+VEGFR-3 inhibitor MAZ51(MAZ51 group);untreated MG63 cells were used as controls.NO production was evaluated by a colorimetric method involving nitrate reductase.Meanwhile,mRNA and protein levels of iNOS were examined by reverse transcription polymerase chain reaction(RT-PCR)and Western blot.To explore the effect of VEGF-C/VEGFR-3/iNOS signaling of MG63 cells on proliferation of HUVECs,we set up six groups:HUVECs,HUVECs+MG63,HUVECs+VEGF-C,HUVECs+MG63+VEGF-C,HUVECs+MG63+VEGF-C+AG,and HUVECs+MG63+VEGF-C+MAZ51 groups.The proliferation of HUVEC cells was assessed by Cell Counting Kit-8(CCK-8),5-ethynyl-2'-deoxyuridine(EdU)incorporation assay,and proliferating cell nuclear antigen(PCNA)expression quantitation.Results VEGF-C treatment enhanced iNOS expression at both gene and protein levels(mRNA:LSD-t=4.152,P<0.01;protein:LSD-t=3.486,P<0.01)and increased NO release of MG63 cells(LSD-t=3.774,P<0.01);treatment with either AG or MAZ51 decreased these effects(mRNA:LSD-t=9.183,P<0.001;LSD-t=8.639,P<0.001;protein:LSD-t=5.170,P<0.001;LSD-t=7.25S,P<0.001;NO production:LSD-t=10.326,P<0.001;LSD-t=l0.540,P<0.001).Interestingly,co-incubation of HUVECs with MG63 cells and/or VEGF-C significantly promoted HUVEC proliferation(EdU:LSD-t=5.374,P<0.001;LSD-t=2.984,P<0.05;LSD-t=8.526,P<0.001;PCNA:LSD-t=9.267,P<0.001;LSD-t=5.515,P<0.001;LSD-t=14.873,P<0.001).The proliferation effects of HUVEC induced by MG63 cells and VEGF-C attenuated by the treatment of AG(EdU:LSD-t=10.770,P<0.001;PCNA:LSD-t=19.94O,P<0.001)or MAZ51(EdU:LSD-t=6.950,P<0.001;PCNA:LSD-t=14.001,P<0.001).Conclusion In human osteosarcoma MG63 cells,activation of VEGFR-3 by VEGF-C promotes iNOS expression and NO production,which subsequendy induces HUVEC proliferation.

Leptin effects on the hypothalamic-pituitary-gonadal axis by activating proopiomelanocortin neurons Correlation between regulatory effects and duration

BACKGROUND：Leptin preserves reproductive functions by stimulating hypothalamic-pituitary-gonadal axis activities at different levels.Some interneurons play an important role in leptin regulation of the gonadal axis.It remains uncertain whether leptin regulates reproductive functions by activating proopiomelanocortin （POMC） neurons.OBJECTIVE：To investigate leptin effects on secretory function of the neuroendocrine-gonadal axis by activating POMC neurons and to observe and verify the relationship between leptin effects and various time points.DESIGN,TIME AND SETTING：The randomized,controlled,animal study was performed at the Basic Institute of Chengde Medical University and the Research Room of Reproductive Immunology of National Research Institute for Family Planning from June to September 2008.MATERIALS：Leptin （Peprotech,USA）,a-melanocyte stimulating hormone and rabbit anti-POMC polyclonal antibody （SC-20148） （Santa Cruz Biotechnology,USA）,follicle stimulating hormone,luteinizing hormone,and gonadotropin releasing hormone enzyme-labeled immunosorbent assay （ELISA） kit （ADL,USA） were used in the present study.METHODS：A total of 60 healthy,female,adult,Wistar rats received 17 （3-estradiol for 5 consecutive days at 15 days after ovariectomy.The rats were randomly assigned to physiological saline （n= 35）,leptin （n = 35）,and a-melanocyte stimulating hormone （n = 20） groups.MAIN OUTCOME MEASURES：Changes in gonadotropin releasing hormone,luteinizing hormone,and follicle stimulating hormone were compared following intraventricular injection of physiological saline,leptin,and a-melanocyte stimulating hormone at various time points.Changes in POMC mRNA and protein expression in the hypothalamus were measured following physiological saline and leptin injection via the lateral ventricle.RESULTS：Compared to the physiological saline group,leptin and a-melanocyte stimulating hormone affected secretion in the hypothalamus-pituitary axis.Leptin affected secretion of gonadotropin releasing hormone,luteinizing hormone,and follicle stimulating hormone,whereas a-melanocyte stimulating hormone inhibited secretion of these hormones.Compared to the physiological saline group,POMC mRNA expression was significantly increased in the hypothalamus at 2 and 4 hours after leptin injection （P〈 0.05）,but expression recovered to physiological saline group levels at 6 hours after injection （P 〉 0.05）.POMC protein expression was significantly increased in the hypothalamus at 4 and 6 hours after leptin injection （P〈 0.05）.CONCLUSION：Leptin affects secretory function of the neuroendocrine-gonadal axis through combined effects on POMC neurons and other pathways.Results suggested that the regulatory effects of POMC neurons were later compared to other neurons.

Effects of Different Fertilization Measures on Chemical Composition and Quality of Flue-cured Tobacco

[Objectives]The paper was to obtain fertilizer varieties and fertilization techniques that meet the special nutritional requirements of characteristic tobacco varieties in Mengyin tobacco area.[Methods]With the local main plant variety NC102 as the test material,the effects of combined application,dosage and application methods of different types of organic fertilizers,compound fertilizers and potassium fertilizers on chemical composition and quality of NC102 flue-cured tobacco leaves were studied.[Results]Under the premise of reducing the amount of fertilizer applied,the slow-release integrated fertilizer increased the sugar-alkali ratio and potassium-chloride ratio,and reduced the sulfur content of tobacco leaves,but it did not significantly improve the sensory quality of tobacco leaves.Increasing the application of organic fertilizer made the sugar-alkali ratio and potassium-chloride ratio more coordinated,reduced the sulfur content and improved the sensory quality of tobacco leaves.Microbial agents significantly increased the sugar-alkali ratio in tobacco leaves,and had obvious effects of increasing potassium and reducing chlorine.Different types and application methods of potassium fertilizers had obvious effects on sensory quality of tobacco leaves.Increasing the application amount of potassium fertilizer and later topdressing significantly improved the potassium content and sensory quality of tobacco leaves.[Conclusions]The study provides a basis for balanced fertilization in characteristic flue-cured tobacco production in Mengyin tobacco area.

The <i>PafR</i>Gene Is Required for Antifungal Activity of Strain MS82 against <i>Mycogone perniciosa</i>

Bacterial strain MS82, isolated from the rhizosphere of a soybean plant, belongs to the species Pseudomonas fluorescens. The most important feature of strain MS82 is the production of antifungal activity against the mushroom pathogenic fungus Mycogone perniciosa but not against the mushroom fungus Agaricus bisporus. In this study, the mutant MS82MT19 generated with the EZ-Tn5 transposon system completely lost the antifungal activity against M. perniciosa. An open-reading frame named as PafR and predicted to code for a sensory box GGDEF/EAL domain protein, was disrupted in MS82MT19. To further confirm the function of this gene, site-directed mutagenesis with insertion of the terminatorless nptII cassette into the PafR gene was used to generate the mutant MS82SD19. As expected, there was no detectable antifungal activity of mutant MS82SD19 against M. perniciosa. These results suggest that the PafR gene plays an important role in the production of antifungal activity of P. fluorescens strain MS82.

Inclusions modification by rare earth in steel and the resulting properties: A review

Rare earth(RE) elements are excellent modifiers for non-metallic inclusions that inevitably appear in steel and affect steel properties. This paper reviews the research status of inclusions modification by RE elements and the changes it cause on steel properties. First, the inclusion changes caused by RE modification are described. Generally, after adding pure RE, the main evolution of inclusions occurs as M →M + RE-Al-O → RE-Al-O + RE_(2)O_(2)S → RE_(2)O_(2)S + RE—S/RE_(2)O_(2)S + RE-O with an increase in the RE content(M represents the inclusions before RE addition). The type of final inclusion obtained after RE modification is related to the relative contents of S and O in the steel. Moreover, fine, regular, and uniformly distributed inclusions can be obtained with appropriate RE addition. However, the effectiveness of inclusions modification by adding both RE and non-RE elements is closely related to the order of their addition. Second, the applications and advantages of thermodynamic calculations in the study of RE-modified inclusions are introduced. Third, the changes in the corrosion resistance, impact properties,and other properties of steel caused by the modification of inclusions by RE are reviewed. Finally, the perspectives and trends of inclusions modified by RE elements in the steel industry are presented.

Ti_(3)C_(2)T_(x) MXene in-situ transformed Li_(2)TiO_(3) interface layer enabling 4.5 V-LiCoO_(2)/sulfide all-solid-state lithium batteries with superior rate capability and cyclability

All-solid-state lithium batteries(ASSLBs)based on sulfide electrolytes promise next-generation energy storage with high energy density and safety.However,the sulfide electrolytes suffer from phase instability and sluggish interfacial charge transport when pairing with layered oxide cathodes at high voltages.Herein,a simple and efficient strategy is proposed using two-dimensional Ti_(3)C_(2)T_(x)MXene as starting material to in-situ construct a 15 nm Li_(2)TiO_(3) layer on a typical oxide cathode,LiCoO_(2).The in-situ transformation of Ti_(3)C_(2)T_(x)into Li_(2)TiO_(3) layer occurs at a low temperature of 500℃,avoiding the phase deterioration of LiCoO_(2).The thin Li_(2)TiO_(3) layer is Li^(+)conducting and electrochemically stable,thereby preventing the interfacial decomposition of sulfide electrolytes induced by LiCoO_(2) at high voltages and facilitating Li+transport at the interface.Moreover,Li_(2)TiO_(3) can stabilize the layer structure of LiCoO_(2) at high voltages.Consequently,the sulfide-based ASSLB using LiCoO_(2)@Li_(2)TiO_(3) cathode can operate stably at a high voltage of up to 4.5 V(vs.Li+/Li),delivering an outstanding initial specific discharge capacity of 138.8 m Ah/g with a high capacity retention of 86.2% after 100 cycles at 0.2 C.The in-situ transformation strategy may also apply to other MXenes,offering a general approach for constructing other advanced lithiated coatings for oxide cathodes.

A self-powered biosensor based on triboelectric nanogenerator for dual-specificity bacterial detection

Pathogenic and corrosive bacteria pose a significant risk to human health or economic well-being.The specific,sensitive,and on-site detection of these bacteria is thus of paramount significance but remains challenging.Taking inspiration from immunoassays with primary and secondary antibodies,we describe here a rational design of microbial sensor(MS)under a dualspecificity recognition strategy using Pseudomonas aeruginosa(P.aeruginosa)as the detection model.In the MS,engineered aptamers are served as the primary recognition element,while polydopamine-N-acetyl-D-galactosamine(PDA-Gal NAc)nanoparticles are employed as the secondary recognition element,which will also generate and amplify changes in the output voltage signal.To achieve self-powering capability,the MS is constructed based on a triboelectric nanogenerator(TENG)with the specific aptamers immobilized on the TENG electrode surface.The as-prepared MS-TENG system exhibits good stability in output performance under external forces,and high specificity toward P.aeruginosa,with no cross-reactivity observed.A linear relationship(R^(2)=0.995)between the output voltage and P.aeruginosa concentration is established,with a limit of detection estimated at around 8.7×10^(3) CFU mL^(-1).The utilization of PDA-Gal NAc nanoparticles is found to play an important role in enhancing the specific and reliability of detection,and the underlying mechanisms are further clarified by computational simulations.In addition,the MS-TENG integrates a wireless communication module,enabling real-time monitoring of bacterial concentration on mobile devices.This work introduces a pioneering approach to designing self-powered smart microbial sensors with high specificity,using a double recognition strategy applicable to various bacteria beyond P.aeruginosa.

μ-opioid receptor agonist facilitates circulating tumor cell formation in bladder cancer via the MOR/AKT/Slug pathway:a comprehensive study including randomized controlled trial

Background:μ-opioid receptor agonists(MORAs)are indispensable for analgesia in bladder cancer(BC)patients,both during surgery and for chronic pain treatment.Whether MORAs affect BC progression and metastasis remains largely unknown.This study focused on the effects of MORAs on the formation of circulating tumor cells(CTCs)in BC and aimed to provide potential therapeutic targets,which would retain the pain-relieving effects of MORAs in BC patients without sacrificing their long-term prognosis.Methods:Different preclinical models were used to identify the effects of MORAs on the progression of BC.A novel immunocapture microfluidic chip was utilized to analyze whether MORAs affected the number of CTCs in mouse models and clinical BC patients.Bioinformatic analyses,total transcriptome sequencing,and molecular biology methods were then used to investigate the underlying mechanisms in these models and in BC cell lines.Results:Mouse models of hematogenous metastasis and in situ BC demonstrated that tumor metastasis was significantly increased after MORA treatment.A significant increase in the number of mesenchymal and/or epithelial CTCs was detected after MORA treatment in both the mouse models and clinical trial patients.Mechanistically,MORAs facilitated the formation of CTCs by activating the MOR/PI3K/AKT/Slug signaling pathway,hereby promoting the epithelialmesenchymal transition(EMT)of BC cells,as knockdown of MOR,Slug or blockade of PI3K inhibited the EMT process and CTC formation.Conclusion:MORAs promoted BC metastasis by facilitating CTC formation.The EMT-CTC axis could be targeted for preventive measures during MORA treatment to inhibit the associated tumormetastasis or recurrence in BC patients.

Storage-reduction strategy for NO_(x) reduction from gas turbine exhaust with W-Ti-CeO_(x) catalyst in natural gas power plants

Traditional vanadium-based selective catalytic reduction(SCR)deNO_(x) catalyst can hardly adapt to the gas conditions(much high NO_(2)/NO_(x) ratio at lower temperature)of the start-up and low loading periods for a gas turbine.Therefore,a W-Ti-CeO_(x) catalyst with NO_(x) storage and reduction(NSR)function was developed in this work for gas turbine exhaust NO_(x) elimination.The experimental results reveal that W-Ti-CeO_(x) catalyst exhibits high NO_(2) adsorption capacity at relatively low temperature while that is quite low for V-W/TiO_(2).The abundant surface Ce^(3+) species can be mainly responsible for its high adsorption ability owing to the reaction between NO_(2) and Ce^(3+) to form nitrate/nitrite species and NO.Meanwhile,the adsorption capacity of W-Ti-CeO_(x) can easily regenerate at medium-high temperature and NH_(3)-SCR reaction.Furthermore,W-Ti-CeO_(x) also shows good NH_(3)-SCR activity,which can fulfill the deNO_(x) process at high temperature.The addition of W and Ti into ceria can enhance the surface acidity and redox ability,thereby increasing the SCR activity.This work proposes a novel storage-reduction strategy for NO_(x) elimination throughout the operation of gas turbines.

Impact localization of composite laminates based on weight function compensation localization algorithm of thin film sensors

Composite structures are sensitive to impact damage in practical engineering.Electric resistance change method(ERCM)is an ideal technique for damage monitoring of composite structures.Due to the anisotropy of fiber-resin matrix composites,impact location monitoring is difficult,and research on impact location of fiber composite laminates(FRPs)is limited.A preparation method of MXene/CNT/CuNps thin film sensor is proposed.According to the modeling simulation and theoretical calculation,the resistance change characteristics of the thin film sensor are obtained,the relationship between the impact distance and the resistance change is established,and the sensor array is designed.A three-point localization algorithm and a weight function compensation localization algorithm are proposed,which can improve the imaging accuracy of the impact position.The impact point location was observed and analyzed using ultrasonic C-scan technology.The results show that the weight function compensation positioning algorithm can accurately locate the impact of the composite structure,and the error in the X direction is 7.1%,the error in the Y direction is 0.03%,which verifies the effectiveness of the method.

一种高效筛选Mx GTPase效应区SNP方法

[目的]建立高效检测家禽Mx功能区SNP方法 ,改进PCR SSCP。[方法]以引进品种和地方品种为研究对象,筛选引物,优化程序,通过二次PCR改进SSCP方法对Mx基因GTPase效应区SNP进行检测。[结果]SSCP检测引物分型检测及SNP分析,检测结果与测序一致。来航鸡检测到阳性结果,且PA检测的多态位点均由编码区A/G替换引起,济宁百日鸡和来航鸡两个群体PIC为0.2515和0.2628,呈低度多态。[结论]χ~2独立性检验位点基因频率和基因型频率呈Hardy-Weinberg平衡,不同品种间位点8(S631N)基因型分布差异极显著(P<0.01)。改进后的PCR SSCP高效经济简便,为高通量后期检测、新位点筛选奠定基础。

石墨烯材料与蛋白质的相互作用

石墨烯材料凭借其优异的物理化学性质在生物化学以及生物医学领域备受关注,展现出了广阔的应用前景。值得注意的是,石墨烯材料在应用于载药、医学检测与诊断及生物成像等诸多领域时,会不可避免地与生物体内的各种蛋白质分子产生相互作用,进而改变石墨烯材料自身的理化性质并影响蛋白质的构象及生物学功能。因此研究石墨烯材料与蛋白质分子之间的相互作用,对于理解和评估其生物学效应,开发新型生物化学技术,具有至关重要的意义。本文综述了近年来针对石墨烯材料与蛋白质分子相互作用开展的代表性的科学研究,分类介绍了石墨烯家族中的各种材料与蛋白质相互作用的分子机制与规律,并介绍了基于蛋白质分子与石墨烯材料相互作用开发的新型应用技术,最后对这一领域未来的热点研究方向进行了分析和展望。

Synergistic control of sex hormones by 17β-HSD type 7: a novel target for estrogen-dependent breast cancer

17β-hydroxysteroid dehydrogenase(17β-HSD)type 1 is known as a critical target to block the final step of estrogen production in estrogen-dependent breast cancer.Recent confirmation of the role of dyhydroxytestosterone(DHT)in counteracting estrogeninduced cell growth prompted us to study the reductive 17β-HSD type 7(17β-HSD7),which activates estrone while markedly inactivatingDHT.The role ofDHTin breast cancer cell proliferation isdemonstratedby its independent suppression of cell growthin the presence of a physiological concentration of estradiol(E2).Moreover,an integral analysis of a large number of clinical samples in Oncomine datasets demonstrated the overexpression of 17β-HSD7 in breast carcinoma.Inhibition of 17β-HSD7 in breast cancer cells resulted in a lower level of E2 and a higher level of DHT,successively induced regulation of cyclinD1,p21,Bcl-2,and Bik,consequently arrested cell cycle in the G0/G1 phase,and triggered apoptosis and auto-downregulation feedback of the enzyme.Such inhibition led to significant shrinkage of xenograft tumors with decreased cancer cell density and reduced 17β-HSD7 expression.Decreased plasma E2 and elevated plasma DHT levels were also found.Thus,the dual functional 17β-HSD7 is proposed as a novel target for estrogen-dependent breast cancer by regulating the balance of E2 andDHT.Thisdemonstrates aconceptual advance on the general belief that the major role of this enzyme is in cholesterol metabolism.

Tailoring the simultaneous abatement of methanol and NO_(x) on Sb-Ce-Zr catalysts via copper modification

Simultaneously removal of NO_(x)and VOCs over NH3-SCR catalysts have attracted lots of attention recently.However,the presence of VOCs would have negative effect on deNOx efficiency especially at low temperature.In this study,copper modification onto Sb_(0.5)CeZr_(2)O_(x)(SCZ)catalyst were performed to enhance the catalytic performance for simultaneous control of NNO_(x)and methanol.It was obtained that copper addition could improve the low-temperature activity of both NOx conversion and methanol oxidation,where the optimal catalyst(Cu_(0.05)SCZ)exhibited a deNOx activity of 96%and a mineralization rate of 97%at 250℃,which are around 10%higher than that of Cu free sample.The characterization results showed that copper addition could obviously enhance the redox capacity of the catalysts.As such,the inhibition effect of methanol incomplete oxidation on NO adsorption and NH3 activation were then lessened and the conversion of surface formamide species were also accelerated,resulting in the rising of NOx conversion at low temperature.However,excessive copper addition would damage the Sb-Ce-Zr oxides solid solution structure owing to Cu-Ce strong interactions,decreasing the surface area and acidity.Meanwhile,due to easier over-oxidation of NH3 with more Cu addition,the temperature window for NOx conversion would become quite narrow.These findings could provide useful guidelines for the synergistic removal of VOCs over SCR catalyst in real application.