Prevalence of vegetation browning in China’s drylands under climate change

Vegetation greening has long been acknowledged,but recent studies have pointed out that vegetation greening is possibly stalled or even reversed.However,detailed analyses about greening reversal or increased browning of vegetation remain scarce.In this study,we utilized the normalized difference vegetation index(NDVI)as an indicator of vegetation to investigate the trends of vegetation greening and browning(monotonic,interruption,and reversal)through the breaks for the additive season and trend(BFAST)method across China’s drylands from 1982 to 2022.It also reveals the impacts of ecological restoration programs(ERPs)and climate change on these vegetation trends.We find that the vegetation displays an obvious pattern of east-greening and west-browning in China’s drylands.Greening trends mainly exhibits monotonic greening(29.8%)and greening with setback(36.8%),whereas browning shows a greening to browning reversal(19.2%).The increase rate of greening to browning reversal is 0.0342/yr,which is apparently greater than that of greening with setback,0.0078/yr.This research highlights that,under the background of widespread vegetation greening,vegetation browning is pro-gressively increasing due to the effects of climate change.Furthermore,the ERPs have significantly increased vegetation coverage,with the increase rate in 2000-2022 being twice as much as that of 1982-1999 in reveg-etation regions.Vegetation browning in southwestern Qingzang Plateau is primarily driven by adverse climatic factors and anthropogenic disturbances,which offset the efforts of ERPs.

基于比特全置乱的超混沌图像加密算法

为提高图像的加密性能,实现更高性能的图像保密传输与保存,基于传统图像置乱和扩散算法,提出一种比特全置乱超混沌图像加密算法。使用新构建的四维超混沌系统将比特分解后的图像进行比特全置乱,生成中间密文图像,然后进行扩散,得到最终密文图像。使用比特分解与超混沌加密加强了密钥流与加密图像的伪随机性。仿真实验表明,该算法加密的图像具有更好的分布特性,既能较好地抵抗统计特性分析和差分攻击,还具有密钥空间大、初值敏感性好等优点。

基于非线性二值化的超混沌伪随机序列生成

为得到随机性和安全性更好的伪随机序列,提出了一种基于非线性二值化的超混沌伪随机序列生成方法。首先,从洛伦兹系统构型出发,构建新的七维超混沌系统,基于耗散性、李指数和相图分析非线性动力学特性;其次,利用该七维超混沌系统产生一个超混沌序列,取出各序列值的小数部分,产生另一新序列;新序列的二值化是将待量化序列点值之前的序列平均值作为动态阈值。仿真实验结果表明,该方法生成的伪随机序列通过了平衡性、相关性、序列检验、初值敏感性以及游程检验等5种随机性检验,从而证明序列具有良好的安全性和随机性。

微波消融与麦默通微创旋切术对乳腺良性肿瘤的疗效分析

目的探讨微波消融与麦默通微创旋切手术治疗乳腺良性肿瘤的疗效。方法择取2021年1—6月至该院就诊的乳腺良性肿瘤患者112例,以奇偶数的次序分为两组,对照组给予麦默通微创旋切手术治疗,研究组给予微波消融手术治疗,对比两组治疗差异性。结果两组出血量、手术时间对比,差异有统计学意义(P<0.05);研究组与对照组的乳房美观优良率分别为94.64%与82.14%,差异有统计学意义(χ^(2)=4.260,P=0.039);研究组与对照组的不良反应发生率分别为3.57%与16.07%,差异有统计学意义(χ^(2)=4.940,P=0.034);两组术后1个月术区血肿吸收情况比较,差异无统计学意义(P>0.05),术后3个月术区血肿吸收情况比较,差异有统计学意义(χ^(2)=4.350,P=0.037)。结论对乳腺良性肿瘤患者采取微波消融手术的疗效显著,其手术所需时间更少,减少了术中出血量等围手术期并发症,值得采纳。

A homeodomain-leucine zipper I transcription factor, MeHDZ14,regulates internode elongation and leaf rolling in cassava(Manihot esculenta Crantz)

Drought stress impairs plant growth and other physiological functions. MeHDZ14, a homeodomainleucine zipper I transcription factor, is strongly induced by drought stress in various cassava cultivars.However, the role of MeHDZ14 in cassava growth regulation has remained unclear. Here we report that MeHDZ14 affected plant height, such that a dwarf phenotype and altered internode elongation were observed in transgenic cassava lines. MeHDZ14 was found to negatively regulate the biosynthesis of lignin. Its overexpression resulted in abaxially rolled leaves. The morphogenesis of leaf epidermal cells was inhibited by overexpression of MeHDZ14, with decreased auxin and gibberellin and increased cytokinin contents. MeHDZ14 was found to regulate many drought-responsive genes, including genes involved in cell wall synthesis and expansion. MeHDZ14 bound to the promoter of caffeic acid 3-Omethyltransferase 1(MeCOMT1), acting as a transcriptional repressor of genes involved in cell wall development. MeHDZ14 appears to act as a negative regulator of internode elongation and epidermal cell morphogenesis during cassava leaf development.

SNHG20调控miR-495对甲状腺癌生物学行为的影响

目的:探讨长链非编码RNA(lncRNA)核内小RNA宿主基因20(SNHG20)调控微小核糖核酸-495(miR-495)对甲状腺癌生物学行为的影响。方法:qRT-PCR法检测SW579、TPC-1、Nthy-ori3-1细胞中SNHG20、miR-495的表达;将SW579细胞分为CON组、si-NC组、si-SNHG20组、si-SNHG20+miR-NC组、si-SNHG20+miR-495 inhibitor组。检测细胞增殖、凋亡、周期和侵袭情况,细胞MMP-2、E-Cadherin、N-Cadherin蛋白表达情况,验证SNHG20和miR-495的关系。结果:与正常甲状腺上皮细胞相比,甲状腺癌细胞株SNHG20表达升高,miR-495表达降低(P<0.05),且SW579细胞SNHG20表达最高,miR-495表达最低,因此后续使用SW579细胞进行转染实验。SNHG20低表达会降低SW579细胞中SNHG20表达、存活率、侵袭个数以及MMP-2和N-Cadherin蛋白表达,升高细胞中miR-495表达、凋亡率、G0/G1期细胞比例以及E-Cadherin蛋白表达(P<0.05);miR-495抑制剂可减弱SNHG20低表达对SW579细胞增殖、侵袭的抑制作用,SNHG20靶向调控miR-495表达(P<0.05)。结论:低表达SNHG20可通过靶向调节miR-495抑制甲状腺癌细胞恶性生物学行为。

Three dimensional photovoltaic fibers for wearable energy harvesting and conversion

As the development of smart electronics, self-powered sources have been attracting increasing attention.This review summarizes research progress of photovoltaic fibers and their integrated power sources with multi-stage energy conversion. Recent development of three dimensional photovoltaic fibers is glanced with special attention to structure design and materials of typical photovoltaic types（inorganic, organic,dye/quantum dot sensitized and perovskite solar cells）. The application of carbon materials in fiber energy is focused as it is a hot topic recently. The hybrid energy systems based on fiber solar cells and fiber supercapacitors, fiber batteries and fiber nanogenerators are summarized together with hybrid energy textiles. This review provides a macroscopic view of novel energy fibers and will attract research interest in flexible/wearable fiber electronics and energy textiles.

Self-standing 3D nanoporous Ag_(2)Al with abundant surface oxygen species facilitating oxygen electroreduction for efficient hybrid Zn battery

The hybrid battery integrating a typical Zn redox battery and a Zn-air battery is a promising green technology for energy storage,and the cathode integrating the redox reaction and electrocatalytic oxygen reduction is a key point for efficient electrochemical energy conversion.Herein,we report a scalable strategy to fabricate nanoporous Ag2 Al internetallic compound as a self-standing cathode for the hybrid Zn battery.The abundant surface oxygen species,the Ag-Al intermetallic interaction and the npAg_(2)Al@AgAlOx interface cooperatively contributed to the catalytic ORR activity.The electrode endows efficient catalytic oxygen reduction(a Tafel slope of 38.0 mV/dec and an onset potential of 0.998 V)and regulated redox activity as compared with Ag.The nanoporous channels allow efficient ion transport,interface charge exchange and gas molecular diffusion.Significantly,the assembled hybrid Zn-Ag_(2) Al/air battery delivers a high capacity of 3.23 mAh/cm^(2) as compared with recent reports.As far as we know,this is the first exploration for the electrochemical property of Ag2 Al,and it would inspire more exploration in developing multifunctional materials and robust hybrid batteries for practical applications.

Down-regulation of MeMYB2 leads to anthocyanin accumulation and increases chilling tolerance in cassava(Manihot esculenta Crantz)

Chilling-induced accumulation of reactive oxygen species(ROS) is harmful to plants,which usually produce anthocyanins to scavenge ROS as protection from chilling stress.As a tropical crop,cassava is hypersensitive to chilling,but the biochemical basis of this hypersensitivity remains unclear.We previously generated Me MYB2-RNAi transgenic cassava with increased chilling tolerance.Here we report that Me MYB2-RNAi transgenic cassava accumulated less ROS but more cyanidin-3-O-glucoside than the wild type under early chilling stress.Under this stress,the anthocyanin biosynthesis pathway was more active in Me MYB2-RNAi lines than in the wild type,and several genes involved in the pathway,including Me TT8,were up-regulated by Me MYB2-RNAi in the transgenic cassava.Me MYB2 bound to the Me TT8 promoter and blocked its expression under both normal and chilling conditions,thereby inhibiting anthocyanin accumulation.Me TT8 was shown to bind to the promoter of Dihydroflavonol 4-reductase(Me DFR-2)and increased Me DFR-2 expression.Me MYB2 appears to act as an inhibitor of chilling-induced anthocyanin accumulation during the rapid response of cassava to chilling stress.

Effect of sevoflurane inhalation and general anesthesia on serum IL-6 and S100β levels and coagulation function in elderly patients undergoing total hip replacement

Objective:To investigate the effects of sevoflurane inhalation general anesthesia on serum IL-6,brain injury protein S100βand coagulation function in elderly patients undergoing total hip arthroplasty.Method:From May 2017 to May 2019,84 patients,age 60-75 underwent total hip arthroplasty in our hospital.were randomly divided into two groups:group A(n=42)and group B(n=42).Group A was maintained with sevoflurane inhalation by general anesthesia and group B with propofol by intravenous anesthesia.The surgical related indexes and postoperative complications in the two groups were compared.The level of serum IL-6,S100β,Coagulation function index[platelet count(PLT),Fibrinogen(FIB),plasma D-dimer(D-D),activated partial enzyme activity time(APTT),prothrombin time(PT)],MMSE score and MoCA score were compared between two groups before and after operation.Results:There was no significant difference in anesthesia time,operation time,intraoperative bleeding and postoperative drainage(P>0.05).1h,1d and 7d after operation,the level of PLT,D-D and FIB in group A were significantly lower than that in group B(P<0.05),PT and APTT were significantly higher than that in group B(P<0.05).1h,1d and 7d after operation,the level of IL-6,S100βin group A were significantly lower than that in group B(P<0.05).1d after operation,the MMSE and MoCA scores in group B were significantly lower than those in group A(P<0.05).The incidence of lower extremity deep venous thrombosis(2.38%)and cognitive impairment(2.38%)in group A was lower than that in group B(14.29%,16.67%)(t1=3.896,P1=0.048;t2=4.974,P2=0.026).Conclusion:sevoflurane anesthesia can reduce the incidence of deep venous thrombosis and cognitive impairment of the lower extremity after operation in elderly patients with thr,stabilize the coagulation index of patients,and downregulate the expression of il-6 and S100β.

Exploration and Practice of the Cultivation Model for Top Undergraduate Talents Based on Subject Contests in the AI Era

With the rise of artificial intelligence and the rapid development of industrial applications based on deep learning,the demand for innovative and practical talents is rapidly increased.The cultivation of talents in computer discipline has attracted a lot of attention from universities,research institutions,and Internet giants.Subject contests play a crucial role in cultivating top undergraduate talents.This paper proposes a cultivation model that takes the industry application of deep learning as the background,and guides students to learn,practice,and innovate incrementally from machine learning application to deep learning application by participating in subject contests.It aims to help undergraduates to master the cutting-edge technologies and applications,and ultimately cultivate top,innovative,and practical undergraduate talents in the computer field in the era of artificial intelligence.

The Mechanism of Swainsonine Causing Early Pregnancy Abnormal Decidualization and Inducing Abortion by Changing Glycosylation Modification

Locoweed is a poisonous plant that severely harms the development of grass-land and animal husbandry throughout the world. Oxytropis and Astragalus are the Latin names for the poisonous plants commonly known as locoweed. The main toxic substance in these plants is swainsonine. It is a strong inhibitor of lysosomal α-mannosidase I and Golgi body α-mannosidase II, resulting in the accumulation of oligosaccharides and glycoproteins in lysosomes, interfering with the molecular and cellular recognition of glycans, and causing tissue-cell vacuolar degeneration. Livestock shows a series of clinical and pathological symptoms, mainly for the decline of reproductive performance. The effects in dams are abortion, weak fetus, and fetal malformations. The key step in maintaining pregnancy in dams is early endometrial decidualization, because reproductive hormones, decidual cell apoptosis, endoplasmic reticulum (ER) stress, and other immune factors are negatively affected by swainsonine. This article addresses the modifications that occur through glycan processing and glycosylation resulting in the change of post-translational modification of the protein and the activity of the glycoprotein, and then direct and indirect mechanisms of ER stress, apoptosis, reproductive hormones, immune factors, and cell cycle and other pathways. Our aim is to find new methods of prevention and treatment of swainsonine poisoning in grassland animals.

Selection and Identification of a Cellulase-producing Strain

[ Objective ] This study aimed to identify a cellulase-producing strain selected from tropical rain forestry soils. [ Method ] Morphologic observation and sequence analysis of 18S rDNA were conducted. [Result] A cellulase-preducing strain with high activity was obtained, and morphology of the strain was highly similar to that of Trichoderma reesei. Results of sequence analysis show that the 18S rDNA sequence shares 99% homology with Hypocreajecorina. [ Conclusion] The isolated cellulase-producing strain belongs to Trichoderma reesei.

无瘤技术在腹腔镜下胃癌根治术中的临床应用价值研究

目的研究与分析无瘤技术在腹腔镜下胃癌根治术中的临床应用价值。方法从该院2016年3月—2017年9月期间内接收的胃癌患者中,随机抽取152例患者,将其分为观察组与对照组,均76例。对照组患者接受传统开腹手术进行治疗,观察组患者接受无瘤腹腔镜胃癌根治术进行治疗。观察两组患者治疗后的效果,观察连住患者手术的基本情况。结果观察组患者治疗后总有效率(97.37%)显著高于对照组患者(82.90%),(χ2=11.774,P=0.001);观察组患者手术时间、术中出血量、住院时间均低于对照组患者,观察组患者淋巴结清扫量高于对照组患者,差异有统计学意义(P<0.05)。结论无瘤技术在腹腔镜下胃癌根治术中应用价值较高,治疗效果较为显著,降低了患者的出血量,较为彻底的清理了患者的淋巴结,有效的预防了癌细胞的扩散,促进了患者的恢复,临床价值较高,值得推广使用。

Cell signaling during drought and/or cold stress in cassava

Cassava(Manihot esculenta Crantz)is a root crop significant in food security and various bio-industrial applications such as animal feed,modified starch,and biofuels.Drought and cold stress are two major factors limiting cassava production qualitatively and quantitatively,for which plants have evolved mechanisms to overcome the impact of these two stressors.In recent years,significant progress has been achieved in understanding the response mechanism of cassava plants to stress signals to tolerate the above stresses.In this review,core stress-signaling pathways,including transcription factor(TF)-related regulatory networks,plant hormone signaling,reactive oxygen species(ROS)scavenging,and non-coding RNA(ncRNA)and alternative splicing(AS)that modify gene expression levels in response to drought and/or cold stress in cassava,are summarized.Understanding these stress signaling and responses will increase our ability to improve the crops tolerance to multiple stresses for agricultural sustainability and food security for the growing world population.

Leflunomide: A versatile additive for defect reduction, enhanced optoelectronic properties and environmental stability of perovskite films

The development of perovskite photoelectric devices with excellent performance is largely dependent on the defects in the perovskite films.To address this issue,a specific drug,leflunomide(LF,C_(12)H_(9)F_(3)N_(2)O_(2)),was incorporated into the perovskite to reduce defects and improve its photoelectric properties.It is believed that the C=O bond on LF molecule can interact with the uncoordinated Pb2+of the perovskite,thereby reducing non-radiative recombination.This novel approach of incorporating LF into perovskite films has the potential to revolutionize the development of high-performance perovskite photoelectric devices.The trifluoromethyl functional(–CF_(3))group on LF can form a protective layer on the surface of the perovskite film,shielding it from water erosion.Moreover,LF can be utilized to alter the nucleation position of perovskite,thus minimizing the number of defects and optimizing the film quality.Consequently,the LF-doped perovskite film displays low trap density and high photoelectric performance.The LF-doped perovskite film showed a trap density of 8.28×10^(11),which is notably lower than the 2.04×10^(12) of the perovskite film without LF.The responsivity and detectivity of the LF-doped perovskite photodetector were 0.771 A/W and 2.81×10^(11) Jones,respectively,which are much higher than the 0.23 A/W and 1.06×10^(10) Jones of the LF-undoped perovskite photodetector.Meanwhile,the LF-doped photodetector maintained an initial photocurrent of 86%after 30 days of storage in air,indicating drastically increased environmental stability.This strongly suggests that LF is an effective additive for perovskites utilized in optoelectronic devices with high performance.

Allele-defined genome reveals biallelic differentiation during cassava evolution

Dear Editor,Generation of heterozygous genomes by hybridization between or within species can help maintain plant diversity and serve as a potential source of new species(Baek et al.,2018).Moreover,genomic heterozygosity is associated with genomic coadaptation,developmental stability,and heterosis.Accurate definition of alleles in haplotypes is necessary to precisely characterize allelic variation controlling agriculturally important traits(Shi et al.,2019).Currently,most released genomes have mosaic assembly of haplotypes due to random selection or collapse of alleles during genome assembly(Shi et al.,2019),which masked allelic variation and functional differentiation of divergent alleles in heterozygous species.

Atomic-level-designed copper atoms on hierarchically porous gold architectures for high-efficiency electrochemical CO reduction

Electrochemical CO_(2) reduction is a promising technology for solving the CO_(2) emission problems and producing value-added products. Here, we report a hierarchically porous Cu1Au single-atom alloy(SAA) as an efficient electrocatalyst for CO_(2) reduction. Benefiting from the hierarchically porous architectures with abundant vacancies as well as three-dimensional accessible active sites, the as-prepared nanoporous Cu1Au SAA catalyst shows remarkable CO_(2) reduction performance with nearly 100% CO Faraday efficiency in a wide potential range(-0.4 to -0.9 V vs. reversible hydrogen electrode. The in-situ X-ray absorption spectroscopy studies and density functional theory calculations reveal that the Cu-Au interface sites serve as the intrinsic active centers,which can facilitate the activated adsorption of CO_(2) and stabilize the *COOH intermediate.

Dynamic shrinkage of metal-oxygen bonds in atomic Co-doped nanoporous RuO_(2) for acidic oxygen evolution

The design of highly active and stable catalysts for the oxygen evolution reaction(OER) in acidic media has become an attractive research area for the development of energy conversion and storage technologies. However, progress in this area has been limited by the poor understanding of the dynamic active structure of catalysts under realistic OER conditions. Here, an atomic Co-doped nanoporous Ru O_(2)electrocatalyst, which exhibited excellent OER activity and stability in acidic conditions, was synthesized through annealing and etching of a nanoporous Co-Ru alloy. Operando X-ray absorption spectroscopy results confirmed that the etching strategy produced abundant oxygen vacancies around the metal centers in the atomic Co-doped nanoporous Ru O_(2)electrocatalyst. These vacancies created contracted metaloxygen ligand bonds under realistic OER conditions. The dynamic structural evolution of the synthesized electrocatalyst allowed them to experience lower kinetic barriers during OER catalysis, resulting in enhanced catalytic activity and stability.This study also provided atomic details on the active structure of the electrocatalyst and the influence of their structural evolution on OER activity.

Research Progresses on Auxin Response Factors

Auxin response factors （ARFs）, a family of transcription factors, have been discovered recently. The ARFs bind specifically to the auxin response elements （AuxREs） within promoters of primary auxin responsive genes and function as activators or repressors. The ARFs contain three domains, namely a conserved Nterminal DNA-binding domain, a non-conserved middle region, and a conserved C-termlnal dlmerlzatlon domaln. The ARFs can form a protein complex with auxin/indoleacetic acid through homodimerization or heterodlmerization. The particular protein-protein interaction may play a key role in moduiating the expression of early auxin responsive genes. The identification of ARF mutations in Arabidopsis helps to demonstrate/dissect the function of ARFs in the normal growth and development of plants. Phylogenetic analysis also reveals some interesting protein evolution points in the ARF family.