Achieving high-efficient photocatalytic persulfate-activated degradation of tetracycline via carbon dots modified MIL-101(Fe)octahedrons

The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)composite photocatalyst was synthesized for visible light-driven photocatalytic/persulfate(PS)-activated tetracycline(TC)degradation.The electron spin resonance(ESR)spectra,scavenging experiment and electrochemical analysis were carried out to reveal that the high visible light-driven photocatalytic degradation activity of TC over CDs/MIL-101(Fe)photocatalysts is not only ascribed to the production of free active radicals in the CDs/MIL-101(Fe)/PS system(·OH,·SO_(4-),^(1)O_(2),h^(+)and·O_(2)^(-))but also attributed to the consumption of electrons caused by the PS,which can suppress the recombination of photo-generated carriers as well as strong light scattering and electron trapping effects of CDs.Finally,the possible degradation pathways were proposed by analyzing intermediates via liquid chromatography-mass spectrometry technique.This research presents a rational design conception to construct a CDs/PS-based photocatalysis/advanced oxidation technology with high-efficient degradation activity for the remediation of organic antibiotic pollutant wastewater and for the improvement of carrier transport kinetics of photocatalysts.

Development of a Simple Extraction Method for Tetracycline Analogues from Bovine Milk

Tetracycline and analogues are among the most used antibiotics in the dairy industry. Besides the therapeutic uses, tetracyclines are often incorporated into livestock feed as growth promoters. A considerable amount of antibiotics is released unaltered through milk from dairy animals. The presence of antibiotic residues in milk and their subsequent consumption can lead to potential health impacts, including cancer, hypersensitivity reactions, and the development of antibiotic resistance. Thus, it is important to monitor residual levels of tetracyclines in milk. The purpose of this study is to develop a quick and simple method for simultaneously extracting five tetracycline analogues from bovine milk. Specifically, five tetracycline analogues: Chlortetracycline (CTC), demeclocycline (DEM), doxycycline (DC), minocycline (MC), and tetracycline (TC) were simultaneously extracted from milk using trifluoroacetic acid. Subsequently, the extracted analogues were separated by reverse-phase high-performance liquid chromatography (RP-HPLC) and detected at 355 nm using UV/Vis. Calibration curves for all five tetracycline analogues show excellent linearity (r2 value > 0.99). Percent recovery for MC, TC, DEM, CTC, and DC were: 31.88%, 96.91%, 151.29, 99.20%, and 85.58% respectively. The developed extraction method has good precision (RSD < 9.9% for 4 of the 5 analogues). The developed method with minimal sample preparation and pretreatment has the potential to serve as an initial screening test.

Efficacy and safety of low-dose tetracycline,amoxicillin quadruple therapy in Helicobacter pylori infection:A retrospective single center study

BACKGROUND Helicobacter pylori(H.pylori)eradication rates have declined with the rise of antibiotic-resistant strains in recent years.Although highly effective with a low prevalence of resistance,standard dose tetracycline is associated with frequent adverse events.The efficacy and safety of low-dose tetracycline as part of tetra-cycline and amoxicillin-containing bismuth quadruple therapy are not well described.AIM To compare the efficacy and safety of low-dose compared to standard dose tetracycline with combined amoxicillin-containing bismuth quadruple therapy in patients with H.pylori infection.METHODS Consecutive patients with H.pylori infection receiving tetracycline,amoxicillin,proton pump inhibitor,and bismuth for 14 days at Sir Run Run Shaw Hospital(1/2022-6/2023)were evaluated.The low-dose tetracycline group received tetracycline 500 mg twice daily(bid)while the standard dose group received 750 mg bid or 500 mg three times daily(tid).Primary endpoints were H.pylori eradication rate and treatment-related adverse events.

Mesoporous amorphous FeOOH-encapsulated BiO_(2–x) photocatalyst with harnessing broad spectrum toward activation of persulfate for tetracycline degradation

With the growing concern about the water environment,the advanced oxidation process of persulfate activation assisted by photocatalysis has attracted considerable attention to decompose dissolved organic micropollutants.In this work,to overcome the drawbacks of the photocatalytic activity reduction caused by the photo-corrosion of non-stoichiometric BiO_(2–x),a novel material with amorphous FeOOH in situ grown on layered BiO_(2–x) to form a core-shell structure similar to popcorn chicken-like morphology was produced in two simple and environmentally beneficial steps.Through a series of degradation activity tests of hybrid materials under different conditions,the as-prepared materials exhibited remarkable degradation activity and stability toward tetracycline in the FeOOH@BiO_(2–x)/Vis/PS system due to the synergism of photocatalysis and persulfate activation.The results of XRD,SEM,TEM,XPS,FTIR,and BET show that the loading of FeOOH increases the specific surface area and active sites appreciably;the heterogeneous structure formed by FeOOH and BiO_(2–x) is more favorable to the effective separation of photogenerated carriers.The optimal degradation conditions were at a catalyst addition of 0.7 g·L^(–1),a persulfate concentration of 1.0 g·L^(–1),and an initial pH of 4.5,at which the degradation rate could reach 94.7%after 90 min.The influence of typical inorganic anions on degradation was also examined.ESR studies and radical quenching experiments revealed that·OH,SO_(4)^(-)·,and·O_(2)^(-)were the principal active species generated during the degradation of tetracycline.The results of the 1,10-phenanthroline approach proved that the effect of dissolved iron ions on the tetracycline degradation was limited,and the interfacial reaction that occurs on the active sites on the material's surface was a critical factor.This work provides a novel method for producing efficient broad-spectrum Bismuth-based composite photocatalysts and photocatalytic-activated persulfate synergistic degradation of tetracycline.

Selective adsorption of tetracycline by β-CD-immobilized sodium alginate aerogel coupled with ultrafiltration for reclaimed water

In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or microscale.Under optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2=0.9977) and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3% of tetracycline after five cycles.Specially,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2 h.The existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting effect.The possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory analysis.In summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.

Carbon-doped CuFe_(2)O_(4) with C-O-M channels for enhanced Fenton-like degradation of tetracycline hydrochloride: From construction to mechanism

Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.

Colloidal Gold Immunochromatographic Assay for Rapid On-Site Detection of Tetracycline in Seawater

Recently increasing concerns from the scientists and public have been paid for seawater pollution due to tetracycline(TC)overuse in maricultural area.However,there are few methods or instruments that can be used for specific and rapid detection of this antibiotic in seawater.In this study,the colloidal gold immunochromatographic assay(CG-ICA)was used to achieve this goal.A commercialized monoclonal antibody against TC(anti-TC mAb)was selected because of its higher sensitivity(half-maximal inhibitory concentration of 2.38μgL^(-1)).The prepared CG particles(average diameter of 20 nm)were used to label anti-TC mAb at pH 8.0.The conjugate pad was formed by spraying the CG-labeled anti-TC mAb on a glass fibre membrane followed by proper dryness.The test pad was made by immobilizing artificial antigen and anti-mouse mAb in the test line and the control line,respectively,in a nitrocellulose membrane.The test strip,assembled with sample pad,conjugate pad,test pad and absorbent pad,could be used to detect TC during seawater sample flowing through these components in turn.The results could be observed by the naked eye in 10min.The visible limit of detection(vLOD)was 20μgL^(-1) for TC in seawater.The CG-ICA test results were in good agreement with those of liquid chromatography-tandem mass spectrometry(LC-MS/MS).The assay also showed that,oxytetracycline(OTC)and chlortetracycline(CTC),as the structural analogues of TC,did not interfere with TC determination.Furthermore,the TC concentration given by test strip could not be affected by the fluctuation of temperature(10℃–30℃),pH(7–9)and salinity(0–40)of seawater.Therefore,CG-ICA is a suitable tool for rapid,on-site,and semi-quantitative detection of TC in seawater.

Synthesis of porous carbon nanomaterials and their application in tetracycline removal from aqueous solutions

The low-cost and efficient elimination of tetracycline from wastewater and to decrease the concentration in soils,sediments,rivers,underground water,or lakes are crucial to human health.Herein,threedimensional porous carbon nanomaterials were synthesized using glucose and NH_(4)Cl by sugarblowing process at 900℃ and then oxidized under air atmosphere for surface functional group modification.The prepared 3D porous carbon nanomaterials were applied for the removal of tetracycline from aqueous solutions.The sorption isotherms were well simulated by the Langmuir model,with the calculated sorption capacity of 2378 mg·g^(-1) for C-450 at pH=6.5,which was the highest value of today's reported materials.The porous carbon nanomaterials showed high stability at acidic conditions and selectivity in high salt concentrations.The good recycle ability and high removal efficiency of tetracycline from natural groundwater indicated the potential application of the porous carbon nanomaterials in natural environmental antibiotic pollution cleanup.The outstanding sorption properties were attributed to the structures,surface areas and functional groups,strong interactions such as H-bonding,π-π interaction,electrostatic attraction,etc.This paper highlighted the synthesis of porous carbon nanomaterials with high specific surfaces,high sorption capacities,stability,and reusability in organic chemicals'pollution treatment.

Facile one-pot synthesis of a BiOBr/Bi_(2)WO_(6) heterojunction with enhanced visible-light photocatalytic activity for tetracycline degradation

Photocatalytic removal of tetracycline(TC)from the wastewater is of great value in the chemical and environmental engineering field.Here,we introduced a facile one-step method for the synthesis of BiOBr/Bi2WO6 heterojunctions by using cheap CTAB as the Br source.We showed the possibility of our method to fine-tune the content of BiOBr in the produced BiOBr/Bi2WO6 by simply changing the dosage of cetyltrimethylammonium bromide(CTAB),providing a platform for the delicate tuning of the visiblelight absorbance ability of the composites.With a suitable heterojunction structure of BiOBr/Bi2WO6-0.2,it exhibited an ultrarapid photocatalytic activity towards TC(20 mg
L^(-1)),with a competitive removal efficiency of 88.1%within 60 min and an ultrahigh removal rate of 0.0349 min^(-1).It could also be robustly recycled for at least 5 cycles with slight removal efficiency loss.We demonstrated that this exciting photocatalytic performance was due to the highly decreased recombination of photoinduced electrons and holes on our composites by constructing this heterojunction structure,and the resulting
OH and
O^(-)_(2)contributed to the effective degradation of TC to CO_(2).

基于TTC染色的水稻种子活力定量分析

为了揭示种子活力与TTC染色之间的定量关系,本研究以水稻种子CY-150为试验材料,经人工加速老化处理和TTC染色后,利用体视镜获取种子胚部纵切面的RGB图像,并用农业农村部植物新品种测试(昆明)分中心建立的图像分析软件分析图像的CIELab值,计算单位面积染色强度。结果表明,发芽率、TTC染色率和活力指数之间呈显著正相关。其中,发芽率和活力指数、发芽率和染色率、染色率和活力指数之间的相关系数分别为0.9976、0.9718和0.9631。此外,CIELab值与发芽率、染色率和活力指数之间显著相关,其中,L^(*)和a^(*)分别呈负相关和正相关,相关系数分别为-0.9749、-0.9761、-0.9721、0.9737、0.9915和0.9678。利用种子活力指数与CIELab值建立了种子活力方程。通过随机选取4个水稻品种对方程进行验证,结果显示,4个品种的活力指数真实值略高于预测值。研究表明,TTC染色不仅可用于水稻种子活力快速定性分析,而且通过种胚RGB图像可以实现种子活力的定量分析,为进一步普及水稻种子活力快速检测提供参考。

老年急性脑梗死患者血清circTTC3和miR-138-5p水平变化及意义

目的探究老年急性脑梗死(ACI)患者血清环状RNA TTC3(circTTC3)和微小RNA-138-5p(miR-138-5p)水平变化及意义。方法选取2021年9月—2023年9月四川大学华西医院老年医学中心/干部医疗科诊治老年ACI患者128例(ACI组),根据美国国立卫生研究院卒中量表(NIHSS)分为轻度亚组42例、中度亚组49例和重度亚组37例,同期医院门诊体检的健康人员120例作为健康对照组;采用实时荧光定量PCR法测定血清circTTC3和miR-138-5p表达水平,Pearson法分析老年ACI患者血清circTTC3和miR-138-5p的相关性,Spearman法分析老年ACI患者血清circTTC3和miR-138-5p表达水平与NIHSS评分相关性,受试者工作特征(ROC)曲线分析血清circTTC3和miR-138-5p表达水平对老年ACI患者神经缺损程度的诊断价值。结果与健康对照组比较,ACI组血清circTTC3表达水平升高,miR-138-5p降低(t/P=17.207/<0.001、16.239/<0.001)。血清circTTC3水平比较,轻度亚组<中度亚组<重度亚组,miR-138-5p表达水平比较,轻度亚组>中度亚组>重度亚组(F/P=26.579/<0.001、105.935/<0.001)。老年ACI患者血清circTTC3表达水平与NIHSS评分呈正相关(r=0.521,P<0.001),与大脑中动脉(MCA)、大脑前动脉(ACA)血流速度呈负相关(r=-0.425、-0.392,P均<0.001);miR-138-5p表达水平与NIHSS评分呈负相关(r=-0.785,P<0.001),与MCA、ACA血流速度呈正相关(r=0.571、0.635,P均<0.001)。circTTC3、miR-138-5p及二者联合诊断ACI神经缺损程度的AUC分别为0.817、0.810、0.878,二者联合诊断价值优于单独诊断(Z/P=2.106/0.035、2.406/0.016)。结论老年ACI患者血清circTTC3表达水平升高,miR-138-5p表达水平降低,二者与患者病情的严重程度密切相关,可能作为ACI病情诊断、治疗相关的作用靶点。

Efficacy and safety of modified tetracycline dosing in a quadruple therapy for Helicobacter pylori:A retrospective single center study

BACKGROUND Although highly effective as a component of Helicobacter pylori(H.pylori)treatment regimen,tetracycline is associated with a high incidence of medicationrelated adverse events.Modified dosing of tetracycline as part of quadruple therapy may improve safety while providing comparable eradication rates.AIM To evaluate the efficacy and safety of modified dosing of tetracycline in patients receiving tetracycline and furazolidone-containing quadruple therapy in patients with H.pylori infection.METHODS Consecutive patients(10/2020-12/2021)who received tetracycline and furazolidone quadruple therapy for H.pylori infection at Sir Run Run Shaw Hospital were identified.All patients received tetracycline,furazolidone,proton pump inhibitor,and bismuth for 14 d as primary or rescue therapy.Modified tetracycline dose group received tetracycline 500 mg twice daily while standard group received 750 mg twice daily or 500 mg three times daily.RESULTS Three hundred and ninety-four patients[mean age=46.3±13.9,male=137(34.8%),and 309(78.4%)primary therapy]completed tetracycline and furazolidone quadruple therapy for H.pylori infection including those who received modified tetracycline dose in 157 and standard doses in 118(750 mg twice daily)and 119(500 mg three times daily).Eradication rates in the modified tetracycline dose group were 92.40%and in the standard groups,eradication rates were 93.20%for 750 mg twice daily group and 92.43%for 500 mg three times daily group,respectively,without statistical difference(P=0.959).The incidence of adverse events was lower in the modified tetracycline dose(15.3%vs 32.3%and 29.4%;P=0.002)compared to the standard dose group.CONCLUSION In a real-world experience,modified tetracycline dosing as part of tetracycline and furazolidone quadruple therapy for 14 d demonstrated high efficacy,comparable to standard tetracycline dose regimens,with a favorable safety profile.

Preliminary Study on the Treatment Efficiency of Pasteurized Lime Thermal Alkaline Hydrolysis for Excess Activated Sludge and Reduction of Tetracycline Resistance Genes

Thermal alkaline hydrolysis is a common pretreatment method for the utilization of excess activated sludge(EAS).Owing to strict environment laws and need for better energy utilization,new methods were developed in this study to improve the efficiency of pretreatment method.Direct thermal hydrolysis(TH),pasteurized thermal hydrolysis(PTH),and alkaline pasteurized thermal hydrolysis(PTH+CaO and PTH+NaOH)methods were used to treat EAS.Each method was compared and analyzed in terms of dissolution in ammonium nitrogen(NH_(4)^(+)-N)and soluble COD(SCOD)in EAS.Furthermore,the removal of tetracycline resistance genes(TRGs)and class 1 transposon gene intI1 from EAS was investigated.The NH_(4)^(+)-N and SCOD concentrations in EAS treated by PTH were 1.24 and 2.58 times higher than those of TH.However,the removal efficiency of total TRGs and intI1 between the groups was comparable.The SCOD concentration of the PTH+NaOH group was 4.37 times higher than that of the PTH group,and the removal efficiency of total TRGs was increased by 9.52%compared with that by PTH.The NH_(4)^(+)-N and SCOD concentrations of the PTH+CaO group could reach 85.04%and 92.14%of the PTH+NaOH group,but the removal efficiency of total TRGs by PTH+CaO was 19.78%lower than that by PTH+NaOH.Thus,to reduce the financial cost in actual operation,lime(CaO)can be used instead of a strong alkali(NaOH),and pasteurized steam at 70℃ instead of conventional high-temperature heating to treat EAS.This study provides a reference for the development of alkaline hydrolysis under moderate temperatures along with the removal of TRGs in EAS.

TTC法测定滇黄精种子生活力条件的优化

以滇黄精种子为试验材料,采用TTC法测定生活力,分别通过正交试验和响应面法对染色温度、染色时间和TTC浓度进行优化。结果显示,正交设计试验最佳测试条件为TTC浓度0.5%、染色温度35℃、染色时间24 h;响应面法试验优化后结果与正交试验一致,利用响应面法优化TTC法测定滇黄精种子生活力的方法可行。

四肽重复结构域36(TTC36)通过增强IκBα的表达抑制NF-κB信号通路的激活抑制HK2人肾小管上皮细胞的炎症反应

目的研究四肽重复结构域(TTC36)对HK2人肾小管上皮细胞损伤的影响及潜在的机制。方法采用慢病毒感染法建立过表达TTC36的HK2稳转细胞系,转入空载质粒CMV-Flag作为对照。实时荧光定量PCR检测HK2细胞肿瘤坏死因子α(TNF-α)、诱导型一氧化氮合酶(iNOS)、白细胞介素6(IL-6)、CC趋化因子配体2(CCL2)、IL-1β以及核因子κB抑制物α(IκBα)、核因子κB p65(NF-κB p65)的mRNA水平。流式细胞术检测细胞凋亡,CCK-8法检测细胞增殖。Western blot法检测iNOS、TNF-α、胱天蛋白酶3(caspase-3)、裂解型胱天蛋白酶3(c-caspase-3)、Bcl2相关X蛋白(BAX)、增殖细胞核抗原(PCNA)、闭锁小带1(ZO-1)、核因子κB(NF-κB)信号通路中IκBα、NF-κB p65、磷酸化的NF-κB p65(p-NF-κB p65)的蛋白表达。放线菌酮(CHX)、蛋白酶体抑制剂MG132处理细胞后,Western blot法检测IκBα的蛋白表达量。结果与对照组相比,HK2细胞过表达TTC36后,炎症介质表达减少;细胞凋亡率降低以及c-caspase-3、BAX表达减弱;细胞增殖加快,PCNA和ZO-1的表达增强;IκBα表达上调,NF-κB p65、p-NF-κB p65表达下调,胞质和胞核中的NF-κB p65表达量均减少。CHX处理后过表达TTC36延长IκBα的半衰期,而MG132可恢复过表达TTC36带来的IκBα的变化。结论过表达TTC36抑制HK2细胞的炎症反应,减少细胞凋亡,促进增殖,加强紧密连接,其机制可能是通过增强IκBα的表达抑制NF-κB信号通路的激活从而减轻炎症反应带来的细胞损伤。

TTC9A在泛癌中的表达水平与多种癌症的预后和免疫微环境相关

目的确定四肽重复蛋白9A(TTC9A)在泛癌中的基因表达及其预后价值,明确其与免疫浸润的关系。方法R语言分析癌症基因组图谱及GTEx网站中TTC9A在不同肿瘤组织与正常组织中的表达及其与各种癌症的预后、DNA甲基化、肿瘤突变负荷、微卫星不稳定性的关系;应用TIMER和xCell比较TTC9A表达与免疫浸润的关系;运用免疫印迹法与RT-qPCR检测TTC9A在4种癌症中的表达情况。结果生信结果显示与正常组织相比,TTC9A在多种肿瘤中mRNA表达水平升高,少数肿瘤中下调(P<0.05)。实验结果显示在肺癌、结肠癌和肝癌中,TTC9A的蛋白和mRNA水平均较正常细胞高,与泛癌分析结果一致;而在膀胱癌细胞系中的表达下降,与泛癌分析结果相反。在头颈鳞状细胞癌、肾透明细胞癌、肾乳头状细胞癌、低级别胶质瘤、恶性间皮瘤、子宫内膜癌等肿瘤中,TTC9A的高表达与更好的总生存期、疾病特异性生存期、无进展间期密切相关(P<0.05);而在肺腺癌、胰腺癌、肾上腺癌、直肠腺癌中,高表达TTC9A与更差的总生存期、疾病特异性生存期、无进展间期密切相关(P<0.05)。在多形成性胶质细胞瘤、低级别胶质瘤、葡萄膜黑色素瘤、卵巢浆液性囊腺癌中,TTC9A高甲基化患者预后较好(P<0.05);但是,在宫颈鳞状细胞癌和宫颈内腺癌、头颈部鳞状细胞癌、肺鳞状细胞癌、肾上腺癌、子宫内膜癌中,TTC9A高甲基化患者预后较差(P<0.05)。TTC9A基因表达分别与7种和4种癌症类型的TMB和MSI显著相关(P<0.05)。在大多数癌症类型中,TTC9A与免疫细胞的浸润水平显著相关(P<0.05),尤其B细胞、CD4^(+)T细胞、CD8^(+)T细胞、巨噬细胞、中性粒细胞和树突状细胞。结论TTC9A可作为多种癌症的预后标志物,且与肿瘤突变负荷、微卫星不稳定性和免疫细胞浸润密切相关。

TTC框架下欧盟和美国人工智能标准化合作重点分析

自2021年欧盟和美国成立欧美贸易技术理事会(TTC)以来,人工智能已经成为其在新兴技术领域寻求标准突破的重点领域.本文分析了欧盟和美国在TTC框架下共同开展人工智能标准化工作的主要行动、趋势和特点,为我国推动人工智能等新兴技术领域标准化发展提供参考与借鉴.

Preparation and characterization of ternary magnetic g-C_3N_4 composite photocatalysts for removal of tetracycline under visible light

A stable PNIPAM/Fe_3O_4/g-C_3N_4 composite photocatalyst was designed and prepared by a thermal photoinitiation technology.The structure and properties of the materials were characterized and the composite photocatalyst was found to show good stability for tetracycline degradation.The sample not only retained the magnetic properties of Fe_3O_4,allowing it to be recycled,but its photocatalytic properties could also be changed by controlling the temperature of the reaction system.The degradation intermediate products of tetracycline were further investigated by MS.This work provides a new facile strategy for the development of intelligent and recyclable photocatalytic materials.

Construction of a Tapetum-Specific and Tetracycline-Inducible System

A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, we constructed a new system that combined tetracycline- inducible elements with TA29 promoter, a tapetum-specific promoter of tobacco. The system was tested in transient GUS assay system by electroporation (gene gun) transformation of tobacco ( Nicotiana tabacum L. cv. Winsconsin 38) anther. In the absence of tetracycline as the inducer, no GUS activity was detected. However, strong GUS expression was observed in tapetum. tissue upon tetracycline induction, and little GUS activity was found outside the tapetum. Our results suggested that gene expression can be restricted to a specific tissue at the given time under the control of this new system, and this system would be a very useful tool for both basic plant biology research and biotechnological applications.

Electrochemically reduced graphene oxide with enhanced electrocatalytic activity toward tetracycline detection

An electrochemically reduced graphene oxide sample, ERGO_0.8v, was prepared by electrochemical reduction of graphene oxide （GO） at -0.8 V, which shows unique electrocatalytic activity toward tetracycline （TTC） detection compared to the ERGO-12v （GO applied to a negative potential of-1.2 V）, GO, chemically reduced GO （CRGO）-modified glassy carbon electrode （GC） and bare GC electrodes. The redox peaks of TTC on an ERGO-0.8v-modifled glass carbon electrode （GC/ERGO-0.8v） were within 0-0.5 V in a pH 3.0 buffer solution with the oxidation peak current correlating well with TTC concentration over a wide range from 0.1 to 160 mg/L Physical characterizations with Fourier transform infrared （FT-IR）, Raman, and X-ray photoelectron spectroscopies （XPS） demonstrated that the oxygen-containing functional groups on GO diminished after the electrochemical reduction at -0.8 V, yet still existed in large amounts, and the defect density changed as new sp2 domains were formed. These changes demonstrated that this adjustment in the number of oxygen-containing groups might be the main factor affecting the electrocatalytic behavior of ERGO. Additionally, the defect density and sp2 domains also exert a profound influence on this behavior. A possible mechanism for the TTC redox reaction at the GC/ERGO-0.8v electrode is also presented. This work suggests that the electrochemical reduction is an effective method to establish new catalytic activities of GO by setting appropriate parameters.