Expression of Ferric Chelate Reductase Gene in Citrus junos and Poncirus trifoliataTissues

It has been hypothesized that under iron stress high ferric chelate reductase (FCR) activity in the absorptive root of plants tolerant to iron_deficiency will be induced and result in subsequent Fe 2+ transport across the plasmalemma. The activity of FCR and expression of FCR gene (FRO2) in Citrus junos Sieb. ex Tanaka tolerant to iron_deficiency and Poncirus trifoliata (L.) Raf. susceptible to iron_deficiency were determined to elucidate the physiological difference which causes the different tolerance of the two citrus rootstocks to iron stress. The activity of FCR was detectable in excised roots and was stimulated about 20_times in C. junos and only about 3_times in P. trifoliata under iron deficiency for four weeks. The FRO2 of Arabidopsis was used as a probe, the tissue print technique was used to ascertain the expression of the FCR gene in C. junos and P. trifoliata under iron stress. High_level transcripts were observed in the absorptive root, young green stem as well as new leaf of C. junos under iron stress for two weeks, and the transcripts were accumulated only slightly in P. trifoliata at the same time. The results showed that the obvious increase of FCR activity was an important reason for the tolerance of C. junos to iron_deficiency, and the regulation of FCR activity seemed to be at the transcriptional level, and the expression of FRO2 occurred in the root, stem and leaf.

多孔MnO_(2)-Fe_(3)O_(4)壳聚糖微球用于增强类Fenton降解染料废水的研究

将壳聚糖与金属盐混合溶液滴入碱性溶液中,采用一步法制备了金属壳聚糖微球(MnO_(2)-Fe_(3)O_(4)/CS),并用于刚果红(CR)的类Fenton降解。结果表明,与单金属壳聚糖微球(MnO_(2)/CS、Fe_(3)O_(4)/CS)相比,MnO_(2)-Fe_(3)O_(4)/CS具有更好的催化活性;在最佳条件下(50 mg/L CR,pH=7,0.9 mol/L H_(2)O_(2),2.0 g/L催化剂,60 min),CR的去除率达到100%。MnO_(2)-Fe_(3)O_(4)/CS的高活性归因于其较大的比表面积和孔体积,特殊多孔结构有利于反应物的吸附/扩散和活性位点的暴露;Mn-Fe双金属之间的协同作用促进了电子传递,有效提高了催化活性。金属壳聚糖微球可以很容易地从反应体系中收集,重复使用5次后仍然保持较高催化活性(88.2%)。

Ecological and Economic Benefits of Vegetation Management Measures in Citrus Orchards on Red Soils

A three-year experiment was conducted to investigate and compare the economic and ecological benefits of six types of vegetation management measures in citrus orchards of the hilly red soil region of the eastern part of China.Six vegetation treatments,including tillage without herbicide(clean tillage)and no tillage without herbicide(sod culture) and with herbicide paraquat(paraquat),glyphosate(glyphosate),glyphosate-glyphosate-paraquat(G-G-P),and paraquat- paraquat-glyphosate(P-P-G),were applied in the citrus orchards on a clayey red soil with slopes of 8°and 13°and a sandy soil with slope of 25°.The results showed that the sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments reduced surface runoff by 38.8%,42.5%,18.7%,28.7%,and 37.5%,then the soil-water losses by 55.5%,51.7%,39.9%,46.8%, and 50.0%,and the N,P,and K nutrient losses by 60.3%,50.2%,37.0%,41.8%,and 45.4%,respectively,as compared with the clean tillage treatment.The weed regeneration ratios with the treatments of clean tillage without herbicide,paraquat, glyphosate,G-G-P,and P-P-G were reduced by 55.1%,67.2%,30.3%,36.8%,and 51.2%,respectively,as compared with the sod culture.The sod culture,paraquat,glyphosate,G-G-P,and P-P-G treatments could increase the soil fertility (annual accumulation of N,P,K,and OM)by 7.1%,6.9%,5.3%,6.2%,and 6.6%,respectively,whereas the clean tillage treatment without herbicide reduced soil fertility by 4.4% after the three-year experiment.The citrus fruit yields in the treatments of paraquat,glyphosate,G-G-P,and P-P-G increased by 7%-10%;the soluble solid,total sugar,total acidity,sugar-acid ratio,and single fruit weight of citrus fruits of all treatments except sod culture significantly(P>0.05) exceeded that of the clean tillage treatment.In general,the paraquat treatment showed the best economic and ecological benefits among the six treatments;therefore,it could be regarded as the best available vegetation management measure in citrus orchards of hilly red soil region to retain water and soil,enhance soil fertility,and improve the yield and quality of citrus.

Antibacterial and Preservation Effects of Silver-doped TiO_2 Nanoparticles on Nanfeng Citrus

[Objective] This study aimed to investigate the antibacterial and preservation effects of silver-doped nano-TiO2 on Nanfeng citrus. [Method] Silverdoped nano-TiO2 preservative film was prepared, to investigate its preservation effects on Nanfeng citrus ripe fruits under novel preservation conditions and detect the influences of nano-composite coating on physiological quality indicators of Nanfeng citrus ripe fruits. [ Result ] Compared with the control, applying nano-compesite coating preservation technology could prevent fruit corruption and water loss and delay the rapid reductioh in contents of citric acid and Vc, without adverse influences on fruit quality. [ Conclusion] Silver-doped nano-TiO2 composite coating can be promoted and applied in frozen storage and preservation practices of Nanfeng citrus.

Citrus fruits are rich in flavonoids for immunoregulation and potential targeting ACE2

The most recent outbreak of 2019 novel coronavirus,named as COVID-19,caused pneumonia epidemic in Wuhan with 2121 deaths cases as of February 20th 2020.Identification of effective antiviral agents to combat the novel coronavirus is urgently needed.Citrus fruit peel or wild citrus are rich in flavonoids,and clinically documented for roles in relief of cough and promotion of digestive health.Therefore,citrus fruits are assumed to possess antivirus activities or enhance the host immunity.A previous study found that hesperetin could act as a high potent inhibitor of SARS-CoV 3CLpro.We determined six flavonoid compounds’content in three citrus species by using LC-MS technique.The content of naringin and naringenin was at higher levels in pummelo.Hesperetin and hesperidin were highly accumulated in mandarin and sweet orange.The subsequent in vitro and in vivo experiments indicated that naringin could inhibit the expression of the proinflammatory cytokines(COX-2,iNOS,IL-1βand IL-6)induced by LPS in Raw macrophage cell line,and may restrain cytokine through inhibiting HMGB1 expression in a mouse model.The results revealed that naringin may have a potential application for preventing cytokine storm.We simulated molecular docking to predict the binding affinity of those flavonoids to bind Angiotensin-converting enzyme 2(ACE 2),which is a receptor of the coronavirus.Consideration of the potential anti-coronavirus and anti-inflammatory activity of flavonoids,the citrus fruit or its derived phytochemicals are promising in the use of prevention and treatment of SARS-CoV-2 infection.

Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

Synergistic CO_(2) mineralization using coal fly ash and red mud as a composite system

CO_(2) mineralization plays a critical role in the storage and utilization of CO_(2).Coal fly ash(CFA)and red mud(RM)are widely utilized as CO_(2) mineralizers.However,the inert calcium species in CFA limit its carbonation capacity,meanwhile the substantial Ca^(2+)releasing of RM is hindered by a covering layer of calcium carbonate.In this study,CO_(2) mineralization in a composite system of CFA and RM was investigated to enhance the carbonation capacity.Multiple analyzers were employed to characterize the raw materials and resulting mineralization products.The results demonstrated that a synergistic effect existed in the composite system of CFA and RM,resulting in improving CO_(2) mineralization rate and efficiency.The produced calcium carbonate was ectopically attached the surface of CFA in the composite system,thus slowing down its coverage on the surface of RM.This phenomenon facilitated further releasing Ca^(2+)from the internal RM,thereby enhancing CO_(2) mineralization efficiency.Meanwhile,the inclusion of RM significantly improved the alkalinity of the composite system,which not only promoted the dissolution of Ca^(2+)of the inert CaSO_(4)(H_(2)O)_(2) in CFA,but also accelerated CO_(2) mineralization rate.The investigation would be beneficial to CO_(2) mineralization using industrial solid wastes.

Down-regulation of tyrosinase,TRP-1,TRP-2 and MITF expressions by citrus press-cakes in murine B16 F10 melanoma

Objective:To investigate the suitability of citrus-press cakes,by-products of the juice industry as a source for the whitening agents for cosmetic industry.Methods:Ethylacetate extracts of citrus-press cakes(CCE)were examined for their anti-melanogenic potentials in terms of the inhibition of melanin production and mechanisim of melanogenesis by using Western Blot analysis with tyrosinese,tyrosinase-related protein-1(TRP-1),TRP2,and microphthalmia-associated transcription factor(MITF)proteins.To apply the topical agents,citrus-press cakes was investigated the safety in human skin cell line.Finally flavonoid analysis of CCE was also determined by HPLC analysis.Results:Results indicated that CCE were shown to down-regulate melanin content in a dose-dependent pattern.The CCE inhibited tyrosinase,TRP-2,and MITF expressions in a dose-dependent manner.To test the applicability of CCE to human skin,we used MTT assay to assess the cytotoxic effects of CCE on human keratinocyte HaCaT cells.The CCE exhibited low cytotoxicity at 50μg/mL.Characterization of the citrus-press cakes for flavonoid contents using HPLC showed varied quantity of rutin,narirutin,and hesperidin.Conclusions:Considering the anti-melanogenic activity and human safety,CCE is considered as a potential anti-melanogenic agent and may be effective for topical application for treating hyperpigmentation disorders.

One-step hydrothermal synthesis of Sn-doped α-Fe_(2)O_(3) nanoparticles for enhanced photocatalytic degradation of Congo red

We report on the synthesis of Sn-doped hematite nanoparticles(Sn-α-Fe_(2)O_(3) NPs)by the hydrothermal method.The prepared Sn-α-Fe_(2)O_(3) NPs had a highly pure and well crystalline rhombohedral phase with an average particle size of 41.4 nm.The optical properties of as-synthesizedα-Fe_(2)O_(3) NPs show a higher bandgap energy(2.40-2.57 eV)than that of pure bulkα-Fe_(2)O_(3)(2.1 eV).By doping Sn intoα-Fe_(2)O_(3) NPs,the Sn-doped hematite was observed a redshift toward a long wavelength with in-creasing Sn concentration from 0%to 4.0%.The photocatalytic activity of Sn-dopedα-Fe_(2)O_(3) NPs was evaluated by Congo red(CR)dye degradation.The degradation efficiency of CR dye using Sn-α-Fe_(2)O_(3) NPs catalyst is higher than that of pureα-Fe_(2)O_(3) NPs.The highest degradation efficiency of CR dye was 97.8%using 2.5%Sn-dopedα-Fe_(2)O_(3) NPs catalyst under visible-light irradi-ation.These results suggest that the synthesized Sn-dopedα-Fe_(2)O_(3) nanoparticles might be a suitable approach to develop a photocatalytic degradation of toxic inorganic dye in wastewater.

NOVEL RED LIGHT-EMITTING POLYMERS BASED ON 2,7-CARBAZOLE AND THIOPHENE DERIVATIVES

A series of conjugated copolymers derived from 9-ethylhexyl-2,7-carbazole(Cz)and 4,7-di(4-hexylthien-2-yl)- 2,1,3-benzothiadiazole(DHTBT)was synthesized by Suzuki polycondensation.The photo-and electro-luminescent properties of these polymers were investigated.Efficient energy transfer from the Cz segment to the DHTBT unit occurs even if the DHTBT content as low as 1 mol%.PL emission was red-shifted significantly from 645 nm to 700 nm with the increase in DHTBT content by 1-50 mol%.PL efficiencies decreased...

Pain-Relief Effects of Aroma Touch Therapy with <i>Citrus junos</i>Oil Evaluated by Quantitative EEG Occipital Alpha-2 Rhythm Powers

Aroma touch therapy is widely used in clinical fields for alleviating pain-related symptoms;however, few studies have reported the pain-relief mechanisms. The present study aimed to elucidate the analgesic effects of aroma touch therapy with Citrus junos oil based on the quantitative evaluation of deep brain network (DBN) activity using electroencephalogram (EEG) occipital alpha-2 rhythm (10-13 Hz) powers. Experimental investigations were performed with 13 healthy volunteers using the cold pressor task for simulating chronic pain in three different sessions: a baseline session with no therapies, a control session with a touch therapy, and an aroma touch therapy. We have found for the first time that the interviewed pain ratings represented by Numeric Rating Scale (NRS) scores were strongly correlated with a DBN activity index, which was derived from the slow fluctuation components of occipital EEG alpha-2 rhythm powers. The correlation was characterized by a V-shaped curve in the DBN activity index versus the pain rating, i.e., the NRS score, which provided the complete analgesic states (NRS = 0) for some subjects under aroma touch therapy at an appropriate DBN activity index. Such analgesic states were not so strongly correlated with emotional valence. In conclusion, aroma touch therapy may directly modulate DBN activity so that pain-induced outcomes are minimized.

Influence of magnetic iron oxide nanoparticles on red blood cells and Caco-2 cells

The interactions of two types of cells (red blood cells, Caco-2 cells) with magnetic iron oxide nanoparticles (non-grafted, citrate-grafted, dendrimer-grafted) of 11 nm in size have been investigated. We focused on two important physiological parameters of the cells, the intracellular pH and the intracellular Ca2+ content. The results show that the nanoparticles do not have a significant influence on the pH and Ca2+ content of Caco-2 cells. The Ca2+ content of red blood cells is also not affected but the intracellular pH is slightly reduced.

Facile One-step Synthesis of Cu2O@Cu Nano-sheet Composites as Reduced Catalyst

Cu2O@Cu nanocomposite was prepared by a simple high temperature calcination reaction in N2 atmosphere.The as-prepared samples were characterized by XRD,SEM and TEM,which indicated that the product formed by nano-sheets stacking had a high specific surface area.The as-synthesized material shows efficient catalytic activity for the reduction of organic compound in aqueous medium,in which 4-nitrophenol can be reduced to p-aminophenol and Congo red can be degraded to colorless solution.

Sol-Gel Preparation of Nanoscale TiO₂/SiO₂Composite for Eliminating of Con Red Azo Dye

A new anatase/SiO2 nanocomposite was synthesized by sol-gel method at room temperature using titanium tetrachloride and tetraethylorthosilicate as raw materials. Characterization of the product was carried out by means of X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) specific surface areas, Thermogravimetry analysis (TGA), Fourier transform infrared (FT-IR), and UV-vis absorption spectroscopy. Thermal phase transformation studies of composite were carried out up to 1100°C which showed the establishment of anatase TiO2 phase. The presence of some tetrahedral coordination of TiO2 species in SiO2 matrix was confirmed by UV-Vis study. The produced TiO2/SiO2 nanocomposite has good photocatalytic properties due to its anatase phase, existence of tetrahedral coordination of TiO2 in the SiO2 matrix and very large surface area. Furthermore, the synthesized anatase/SiO2 shows significant adsorption ability towards Congo Red (CR) azo dye in comparison with the pure commercial TiO2 which is known as Degussa, P25.

耕作措施对红壤坡耕地土壤CO_(2)排放的影响

[目的]探析红壤坡耕地不同耕作措施对土壤二氧化碳(CO_(2))排放的影响,为红壤坡耕地绿色低碳耕作模式构建与耕作措施优化提供理论依据。[方法]通过设置横坡垄作(RT)、顺坡垄作(DT)、覆膜耕作(PM)和传统耕作(CT)4种典型耕作措施试验小区,采用结构方程模型探究了土壤理化性状与土壤CO_(2)排放间的响应关系,并采用综合评价模型定量分析了不同耕作措施的降碳增产综合效益。[结果]RT的土壤有机碳和全氮含量总体较高,可显著增加土壤总孔隙度,降低土壤容重(p<0.05),DT则相反;PM的土壤温度及含水率显著高于其余耕作措施,RT和DT为代表的垄作措施显著高于CT。在作物生育期内,不同耕作措施的土壤CO_(2)排放通量在60.53~818.90 mg/(m^(2)·h),呈先升高后降低的波动趋势,耕作措施间土壤CO_(2)累计排放量大小关系为PM>DT>CT>RT,RT可显著减少3.4%~22.4%(p<0.05),而作物生育期间为花粒期>穗期>苗期。降雨侵蚀对红壤坡耕地土壤CO_(2)排放具有明显“Birch效应”,降雨侵蚀后耕作措施间土壤CO_(2)排放通量大小关系为DT>PM>CT>RT。红壤坡耕地主要通过调节土壤温度、土壤含水率、全氮和容重来影响土壤CO_(2)排放通量。[结论]RT对降低土壤CO_(2)排放及增加作物产量具有积极作用,可优先在南方红壤坡耕地进行推广。

T2DM患者红细胞体积、血红蛋白变化及其临床意义探讨

目的探讨2型糖尿病(T2DM)患者平均红细胞体积(MCV)、血红蛋白(Hb)变化及其临床意义。方法选择2021年1月—2023年1月本院收治的240例2型糖尿病(T2DM)患者(T2DM组)及本院同期健康体检者240名(健康对照组)作为研究对象,空腹采血,应用全自动血液分析仪检测其MCV、Hb和糖代谢指标[空腹血糖(FPG)、餐后2 h血糖(2 h PG)、糖化血红蛋白(HbA1c)]。比较T2DM组、健康对照组的MCV、Hb水平;Pearson分析T2DM组MCV、Hb与糖代谢指标的相关性;随访1年统计T2DM组微血管并发症发生率,并分为发生组、未发生组,Logistic回归分析T2DM微血管并发症的影响因素。结果与健康对照组比较,T2DM组MCV水平较高(P<0.05),Hb水平较低(P<0.05);T2DM组MCV与FBG、2 h BG、HbA1c呈正相关(P<0.05),Hb与FBG、2 h BG、HbA1c呈负相关(P<0.05);T2DM微血管并发症发生率为32.88%(72/219);体质量指数(BMI)(OR=1.370,95%CI:1.129~1.664)、高血压(OR=1.342,95%CI:1.116~1.613)、高脂血症(OR=1.302,95%CI:1.085~1.562)、MCV(OR=1.373,95%CI:1.126~1.674)、T2DM病程(OR=1.380,95%CI:1.121~1.699)、Hb(OR=0.734,95%CI:0.594~0.907)和血糖控制不达标(OR=1.365,95%CI:1.126~1.654)为T2DM微血管并发症发生的影响因素(P<0.05)。结论T2DM患者MCV异常升高,Hb异常降低,与糖代谢指标存在相关性,与BMI、高血压、高脂血症、T2DM病程和血糖控制不达标共为T2DM微血管并发症发生的影响因素。

利用Red重组系统敲除APEC毒力岛irp2基因

应用质粒pKD46介导的Red同源重组系统,以质粒pKD3为模板,设计irp2基因序列敲除引物,引物5′端有51 bp的拟敲除基因的同源臂,3′端为扩增引物,扩增两侧含FRT位点的氯霉素抗性基因,通过第1次同源重组将拟敲除的irp2基因替换为氯霉素抗性基因,再通过重组酶质粒pCP20在FRT位点发生第2次同源重组,消除抗性基因。结果表明,利用该重组系统成功敲除了禽致病性大肠杆菌HPI毒力岛irp2基因。为深入研究irp2基因在禽致病性大肠杆菌致病过程中所发挥的作用打下基础。

Luminescent properties of Lu_2MoO_6:Eu^(3+) red phosphor for solid state lighting

The Eu^3＋ activated Lu2MoO6 phosphors were synthesized by high-temperature solid-state reaction method. The X-ray diffraction （XRD）, excitation spectra, emission spectra and decay lifetime of the phosphors were measured to characterize the structure and luminescent properties. The XRD results show that all the prepared phosphors can be assigned to the monoclinic structure. The experimental results indicate efficient absorption of near ultraviolet light from the Mo^6＋O^2- group followed by intensive emission in the visible spectral range. The optimal content of Eu3＋ is 10% （mole fraction）. The critical distance Rc and energy transfer mechanism were also discussed in detail. This red emitting material may be applied as a promising red phosphor for the near ultraviolet excited white light emitting diodes.

湘南红壤对NO_3^-和SO_4^(2-)的吸附机理研究

本文研究了湘南第四纪红粘土发育的红壤对NO_3和SO_4^(2-)的吸附等温线。结果表明红壤对NO_3^-的吸附在浓度低时为负吸附,浓度高时为正吸附,吸附机理为非专性吸附,红壤对SO_4^(2-)的吸附等温式以Freundlich方程最好,在达到最大吸量(X_m)之前,SO_4^(2-)以置换羟基(—OH)的配位吸附为主;而在达到最大吸附量以后,以非专性物理吸附为主。

新生MnO_2对直接染料废水的脱色作用

以化学法合成的新生MnO2 作吸附剂 ,对直接桃红 12B(Directred 12B)、直接大红 4B(Directreb 4B)、直接耐晒蓝B2 RL(DirectFastblueB2 RL)染料废水进行脱色研究 ,探讨了影响吸附的因素。结果表明 :新生Mn0 2 对三种染料的吸附符合Langmuir吸附等温式 ,吸附速率大 ,在适宜条件下对直接桃红、直接大红、直接耐晒蓝的脱色率分别为 95 .5 %、96 .2 %和 98.9%