MIR1868 negatively regulates rice cold tolerance at both the seedling and booting stages

Low temperature causes rice yield losses of up to 30%–40%,therefore increasing its cold tolerance is a breeding target.Few genes in rice are reported to confer cold tolerance at both the vegetative and reproductive stages.This study revealed a rice-specific 24-nt miRNA,miR1868,whose accumulation was suppressed by cold stress.Knockdown of MIR1868 increased seedling survival,pollen fertility,seed setting,and grain yield under cold stress,whereas its overexpression conferred the opposite phenotype.Knockdown of MIR1868 increased reactive oxygen species(ROS)scavenging and soluble sugar content under cold stress by increasing the expression of peroxidase genes and sugar metabolism genes,and its overexpression produced the opposite effect.Thus,MIR1868 negatively regulated rice cold tolerance via ROS scavenging and sugar accumulation.

Secure Short-Packet Transmission in Uplink Massive MU-MIMO Assisted URLLC Under Imperfect CSI

Ultra-reliable and low-latency communication(URLLC)is still in the early stage of research due to its two strict and conflicting requirements,i.e.,ultra-low latency and ultra-high reliability,and its impact on security performance is still unclear.Specifically,short-packet communication is expected to meet the delay requirement of URLLC,while the degradation of reliability caused by it makes traditional physical-layer security metrics not applicable.In this paper,we investigate the secure short-packet transmission in uplink massive multiuser multiple-inputmultiple-output(MU-MIMO)system under imperfect channel state information(CSI).We propose an artificial noise scheme to improve the security performance of the system and use the system average secrecy throughput(AST)as the analysis metric.We derive the approximate closed-form expression of the system AST and further analyze the system asymptotic performance in two regimes.Furthermore,a one-dimensional search method is used to optimize the maximum system AST for a given pilot length.Numerical results verify the correctness of theoretical analysis,and show that there are some parameters that affect the tradeoff between security and latency.Moreover,appropriately increasing the number of antennas at the base station(BS)and transmission power at user devices(UDs)can increase the system AST to achieve the required threshold.

不同形态聚对苯二甲酸乙二醇酯对醇解效率的影响

以二甘醇(DEG)为醇解剂、无水氯化亚锡(SnCl2)为催化剂,采用一步进料和分步进料醇解法,研究了聚对苯二甲酸乙二醇酯(PET)瓶片、PET粒料和PET纤维的醇解反应。通过扫描电镜、差示扫描量热分析、热重分析、红外光谱、核磁共振等方法表征了不同形态PET材料及其醇解产物的结构与热性能。结果表明,PET材料化学结构不会因为它的形态发生变化,但熔点和结晶度有明显的不同,其中PET纤维的熔点(253℃)和结晶度(43.44%)均高于PET瓶片和PET粒料。当醇解温度为220℃、反应为180 min时,一步进料醇解法的PET材料的醇解率依次为瓶片粒料纤维(依次为98.8%,98.8%,80.8%);当醇解温度为220℃、反应时间为90 min时,分步进料醇解法的PET瓶片和粒料的醇解率均达到100%、纤维的醇解率达到92.5%;一步进料醇解法的醇解率依次为瓶片42.1%、粒料38.5%、纤维28.0%,分别提高了57.9%,61.5%和64.5%。文中研发的分步进料醇解法技术可以使PET材料醇解反应时间缩短1/2,且PET纤维的醇解率有明显提升。

Introduction to Wireless Endogenous Security and Safety:Problems, Attributes, Structures and Functions

The information security and functional safety are fundamental issues of wireless communications sytems.The endogenous security principle based on Dynamic Heterogeneous Redundancy provides a direction for the development of wireless communication security and safety technology.This paper introduces the concept of wireless endogenous security from the following four aspects.First,we sorts out the endogenous security problems faced by the current wireless communications system,and then analyzes the endogenous security and safety attributes of the wireless channel.After that,the endogenous security and safety structure of the wireless communications system is given,and finally the applications of the existing wireless communication endogenous security and safety functions are listed.

Neuroprotective effect of Longshengzhi capsule following permanent middle cerebral artery occlusion in rats

Objective:Longshengzhi capsule(LSZC)is an optimized preparation based on the traditional Chinese Medicine formula Buyanghuanwu Decoction(BYHWD),and is approved by the China Food and Drug Administration for treating stroke-induced disability and vascular diseases.Herein,we examined the pharmacodynamics,anti-apoptotic and anti-oxidant actions,and potential mechanisms of action of LSZC following stroke in rats.Methods:Permanent middle cerebral artery occlusion(MCAO)was used as an ischemic stroke model.LSZC was administered intragastrically.We examined the survival rate,bodyweight,and neurological deficits in stroke rats.Brain infarct size was determined by 2,3,5-triphenyltetrazolium chloride staining.Brain pathology was examined using hematoxylin and eosin staining,Nissl staining,and TdT-mediated dUTP Nick-End Labeling staining.Malondialdehyde,catalase,superoxide dismutase,and glutathione levels were examined by commercial kits.Expression of Nrf2,heme oxygenase-1,Bax,Bcl-2,cleaved caspase-3,and caspase-3 proteins in brain tissue was measured by Western blot.Results:LSZC markedly improved the survival rate and bodyweight,and reduced infarct volume and neurological deficit scores,in MCAO stroke rats.LSZC also significantly attenuated oxidative stress,as indicated by decreased expression of malondialdehyde,and upregulation of Nrf2,heme oxygenase-1,catalase,superoxide dismutase,and glutathione.Moreover,LSZC significantly decreased apoptosis,including a decrease in Bax and cleaved caspase-3 expression,and an increase in Bcl-2,as well as a reduction in numbers of apoptotic neurons.Conclusion:LSZC treatment is neuroprotective against ischemic stroke,potentially via reducing oxidative stress and apoptosis.The Nrf2 and apoptotic signaling pathways may play important roles in the antioxidant and anti-apoptotic actions of LSZC.

HACCP体系协同栅栏技术在甜炼乳生产中的应用

将HACCP体系与栅栏技术相结合,应用于甜炼乳的现代化加工中。甜炼乳生产过程中具有五个关键控制点。根据五个关键控制点,有针对性地设计六个"栅栏";通过二者结合,以保证甜炼乳的卫生安全,减少不合格品数量,延长炼乳保质期,并提高企业经济效益。

The Description of Oil Displacement Mechanism in Steam Injection of Multi-Field Synergy with Exergy Transfer

Steam injection is a most effective way for improving heavy oil recovery efficiency, and it has academic and practical significance for the mechanism of multi-field synergy oil displacement. Mechanism of “diversified” oil displacement which is obtained by traditional study methods in the exploitation territory of oil and gas fields has both respective roles and mutual cross shortages. To describe and analyze the displacement process of multi-field coupling with exergy transfer can simplify this kind of problem by introducing a unified goal-driving exergy. It needs to use the method of theoretical modeling, numerical simulation and experimental validation to study the basic law of exergy transfer in the oil displacement process of multi-field synergy, make a thorough research for the flooding process of steam injection with exergy transfer theory and reveal the oil displacement mechanism in steam injection of multi-field synergy. Thus the theory instruction and technical support can be provided to improve reservoirs producing degree and extraction ratio.

Research progress for microRNA in the pathological mechanism of brain injury after stroke

Ischemic stroke is a leading cause of death and disability.Despite extensive research,treatment for ischemic stroke is limited to thrombolytic therapy and symptom management.Identifying and testing new therapeutic targets is therefore critical for future clinical-ly viable stroke therapies.Noncoding RNAs,especially microRNAs(miRNAs),are one of many classes of mole-cules that cause functional changes before,during,and af-ter ischemic stroke.Current research finds that expression levels of many miRNAs are altered in the blood and brain of rodents and humans after stroke.In addition,miRNA can be regulated by external factors to improve functional outcomes after ischemic stroke.In certain studies,induction of ischemic tolerance by preconditioning(PC)also altered the levels of many miRNAs.This review focuses on miRNAs that modulate stroke-related risk factors and pathologic mechanisms of post-stroke brain injury.

Induced neuronal differentiation of neural stem cells by a combination of cytokines One-step versus two-step methods

BACKGROUND： A combination of basic fibroblast growth factor （bFGF）, platelet-derived growth factor （PDGF）, human heregulin-beta-1, beta-mercaptoethanol retinoic acid and forskolin has been reported to induce the differentiation of rat bone marrow stromal cells into myelinating Schwann-like cells. OBJECTIVE： To investigate the inducing effects of a combination of bFGF, PDGF, human heregulin-beta-1, beta-mercaptoethanol retinoic acid and forskolin on neural stem cell differentiation by one- and two-step methods. DESIGN, TIME AND SETTING： A cytobiology experiment was performed at the Department of Histology and Embryology, Medical School of Nantong University, and Jiangsu Province Key Laboratory of Neuroregeneration, China, between August 2005 and January 2007. MATERIALS： A total of 30 healthy Sprague Dawley rat embryos at gestational days 14-16 were selected, bFGF, PDGF, human heregulin-beta-t, beta-mercaptoethanol, retinoic acid, and forskolin were purchased from Sigma, USA. METHODS： Passage 3 rat neural stem cells were cultured by a one-step method in serum-free medium plus 10 ng/m/bFGF, 5 ng/mL PDGF, 200 ng/mL heregulin-beta-1,35 ng/mL all-trans retinoic acid, and 5 pmol/L forskolin or by a two-step method in serum-free medium plus 35 ng/m/ all-trans retinoic acid for 72 hours, followed by serum-free medium plus 10 ng/mL bFGF, 5 ng/mL PDGF, 200 ng/mL heregulin-beta-t and 5 μmol/L forskolin. The control condition consisted of 10% fetal bovine serum alone or 20 ng/mL bFGF alone. MAIN OUTCOME MEASURES： Differentiated cells were identified by immunocytochemical staining for microtubule associate protein-2 （MAP2） and St 00 protein. Geometric parameters and sodium ion currents of the differentiated cells were measured by image analysis and whole-cell patch-clamp techniques, respectively. RESULTS： Compared with the two-step culture method, neuronal-like cells exhibited longer processes and a similar appearance to mature neurons using the one-step method. The percentage of MAP2 positive cells induced by the one-step method was significantly greater than the serum-alone group （P 〈 0.05）. Furthermore, the MAP2 positive cells induced by the one-step method had greater surface areas, cell body perimeters, and longer process than cells induced by serum-alone and bFGF-alone （P 〈 0.05）. There were no significant differences in these parameters between the one-step and two-step methods （P 〉 0.05）. In addition, 80% of the induced neuronal-like cells from the one-step method and 20% from the two-step method displayed inwardly-evoked currents. CONCLUSION： The combination of bFGF, PDGF, human heregulin-beta-t, beta-mercaptoethanol retinoic acid and forskolin successfully induced neuronal differentiation from neural stem cells, with the one-step induction being more effective than the two-step method.

EFFECTS OF NAAG AND MPEP ON RAT CORTICAL SPREADING DEPRESSION

Cortical spreading depression(CSD)is a pathophysiological phenomenon.There are sufficient evidences to prove that CSD plays an important role in some neurological disorders.However,exact mechanisms of its initiation and propagation are still unclear.Previous studies showed that glutamate receptors could be concerned with CSD,but those studies were mostly performed oriented to ionotropic glutamate receptors(iGluRs).There is relatively little report about effects of metabotropic glutamate receptors(mGluRs)on CSD.Here,we applied optical intrinsic signal imaging(OISI)combined with direct current(DC)potential recording to examine influences of some mGluRs antagonist(or agonist)on CSD propagation in rat’s brain,to indirectly validate actions of some mGluRs on CSD.We found that N-acetyl-l-aspartyl-l-glutamate(NAAG,an agonist at mGluR3)inhibited the propagation of CSD,and the inhibition was gradually developed with time.However,6-methyl-2-phenylethynyl-pyridine(MPEP,an antagonist of mGluR5)did not produce any significant alterations with the CSD propagation.Our findings suggest that mGluR3 could play an important role in the CSD propagation,but the activity of mGluR5 was comparatively weak.These findings can help to understand the propagation mechanism of CSD,and consider the therapy of some neurological diseases involved with CSD.

ACCURATELY DETERMINING PROPAGATION VELOCITY OF CORTICAL SPREADING DEPRESSION IN RATS BY OPTICAL INTRINSIC SIGNAL IMAGING

Cortical spreading depression(CSD)is a wave of neuronal and glial depolarization that propagates across the cortex at a rate of 2–5mm/min accompanied by reversible electroencephalogram(EEG)suppression,a negative shift of direct current(DC)potential,and change of optical intrinsic signals(OIS).Propagation velocity of CSD is an important parameter used to study this phenomenon.It is commonly determined in an electrophysiological way that measures the time required for a CSD wave to pass along two electrodes.Since the electrophysiology technique fails to reveal the spreading pattern of CSD,velocity calculated in this manner might be inaccurate.In this study,we combined the electrophysiological recording and OIS imaging(OISI)for detecting changes in DC potential and OIS during CSD simultaneously.An optical method based on OISI to determine the CSD velocity,which is measured by generating a series of regions of interest(ROI)perpendicular to the advancing wavefront along propagation direction of CSD at different time points and then dividing by the distance between ROIs over time,is presented.Comparison of the accuracy of the two approaches in determining the CSD velocity is made as well.The average rate of 33 CSDs is 3.52±0.87mm/min by use of the optical method and 4.36±1.65mm/min by use of the electrophysiological method.Because of the information about spreading pattern of CSD provided optically,the velocity determined by OISI is of smaller deviation and higher accuracy.

Use of Qishen granule for the treatment of heart failure: A systematic review and meta-analysis of animal studies

Objective:To evaluate the effect of Qishen granule(QSG)on heart failure(HF)and the potential mechanisms involved in animal models.Methods:Studies of QSG in animals with HF were identified by searches of eight databases up to August 1,2019.Two authors independently reviewed each study and the Collaborative Approach to Metaanalysis and Review of Animal Data from Experimental Studies 10-item checklist was used for quality assessment.The primary outcomes were indicators of left ventricular ejection fraction and/or left ventricular fractional shortening.The secondary outcome measures were ventricular structure,hemodynamics,myocardial injury-related indicators,and the mechanisms whereby QSG ameliorates HF.A metaanalysis was performed and all the data were analyzed using RevMan 5.3 software.Results:Thirteen studies containing a total of 240 animals met the criteria for the meta-analysis.The quality score of the studies ranged from three to six points.The meta-analysis showed a significant effect of QSG to improve cardiac function,inhibit ventricular remodeling,improve circulation,and attenuate myocardial injury.The possible mechanisms was identified to be suppression of the renin-angiotensinaldosterone system,which has anti-fibrotic,anti-apoptotic,anti-inflammatory,and anti-oxidative effects in the myocardium,the prevention of calcium overload,and the promotion of myocardial energy metabolism.Conclusion:Our review shows that QSG has a cardioprotective effect in animal models of CHF.However,due to the relatively poor quality of the included studies and the differences between humans and animal models,the results should be interpreted with caution.

Road sub-surface defect detection based on gprMax forward simulation-sample generation and Swin Transformer-YOLOX

Training samples for deep learning networks are typically obtained through various field experiments,which require significant manpower,resource and time consumption.However,it is possible to utilize simulated data to augment the training samples.In this paper,by comparing the actual experimental model with the simulated model generated by the gprMax[1]forward simulation method,the feasibility of obtaining simulated samples through gprMax simulation is validated.Subsequently,the samples generated by gprMax forward simulation are used for training the network to detect objects in existing real samples.At the same time,aiming at the detection and intelligent recognition of road sub-surface defects,the Swin-YOLOX algorithm is introduced,and the excellence of the detection network,which is improved by augmenting the simulated samples with real samples,is further verified.By comparing the prediction performance of the object detection models,it is observed that the model trained with mixed samples achieved a recall of 94.74%and a mean average precision(maP)of 97.71%,surpassing the model trained only on real samples by 12.95%and 15.64%,respectively.The feasibility and excellence of training the model with mixed samples are confirmed.The potential of using a fusion of simulated and existing real samples instead of repeatedly acquiring new real samples by field experiment is demonstrated by this study,thereby improving detection efficiency,saving resources,and providing a new approach to the problem of multiple interpretations in ground penetrating radar(GPR)data.

Substrate screening for superclean graphene growth using firstprinciples calculations

Suppressing the formation of amorphous surface carbon and contaminants during the preparation of graphene by chemical vapor deposition remains an ongoing issue.Herein,we analyzed how substrate characteristics affect graphene quality by simulating margin extension,the nucleation process,and defect pegging configurations on mono-crystalline oriented metal substrates with the aim of enhancing graphene cleanliness.Defect formation energy and nucleation potential,which are indirect substrate–graphene interaction features,were found to appropriately evaluate graphene quality.The crystallographic orientation of the metal substrate was discovered to be critical for producing superclean graphene.A low graphene defect density and high nucleation rate on the Cu(100)facet guarantee growth of high-quality graphene,especially in terms of suppressing the formation of amorphous carbon.In addition,rapid kink growth and self-healing on the Cu(100)facet facilitate rapid graphene synthesis,which is also promoted by rapid kink splicing and margin self-repair on this facet.This study provides theoretical insight useful for the synthesis of superclean graphene.

Design and fabrication of self-suspending aluminum-plastic/semiconductor photocatalyst devices for solar energy conversion

The design and synthesis of self-suspending photocatalyst device with easy recyclability is important for practical application.Here,this work utilizes aluminum-plastic package waste as raw material to prepare an aluminum-plastic supported TiO_(2)(AP-TiO_(2))photocatalyst device through 3D printing design and surface deposition method.A series of characterizations were carried out to explore the structure,morphology and performance of the AP-TiO_(2)device.Under UV light illumination,the AP-TiO_(2)-50 efficiently degrade 93.6%tetracycline hydrochloride(THC)after 4 hr,which increases by 8.3%compared with that of TiO_(2)powder suspension system with the same catalyst amount.Based on it,AP-ZnO,AP-CdS,AP-g-C_3N_4and AP-Pt-TiO_(2)are also fabricated,and applied in photocatalytic degradation and hydrogen evolution,which all exhibit higher photoactivities than powder suspension systems.This work provides a new avenue for the fabrication of advanced recyclable photocatalyst device.Moreover,the work offers a novel sight for the high-value utilization of aluminum-plastic package waste,which has positive implications for environmental protection.

Theoretical investigations on the growth of graphene by oxygenassisted chemical vapor deposition

Recently,graphene has drawn considerable attention in the field of electronics,owing to its favorable conductivity and high carrier mobility.Crucial to the industrialization of graphene is its high-quality microfabrication via chemical vapor deposition.However,many problems remain in its preparation,such as the not fully understood cracking mechanism of the carbon source,the mechanism of its substrate oxidation,and insufficient defect repair theory.To help close this capability gap,this study leverages density functional theory to explore the role of O in graphene growth.The effects of Cu substrate oxidation on carbon source cracking,nucleation barriers,crystal nucleus growth,and defect repairs are discussed.OCu was found to reduce energy change during dehydrogenation,rendering the process easier.Moreover,the adsorbed O in graphene or its Cu substrate can promote defect repair and edge growth.

6G无线内生安全理念与构想

6G开放融合、异构共存、智能互联的网络特点将引发更多未知复杂安全威胁,目前安全滞后于通信发展的格局必然难以应对,6G时代必须打破思维定势,催生真正具有代际效应的标志性技术.内生安全从无线网络内源性缺陷产生的共性和本源安全问题出发,通过结构导向的解决方法,具有抵御未知安全威胁的能力和通信/安全/服务内源性融合的能力.本文对6G无线网络内生安全问题、理念进行了探讨,并提出内生安全在6G超高速宽带通信、超大连接超低时延、天地一体化全域覆盖等典型场景中的应用构想,给出了若干潜在关键技术和解决方案.

Image reconstruction for the coded aperture system in nuclear safety and security using a Monte Carlo-based system matrix

Purpose Accurate localization of radioactive materials is critical to nuclear safety and nuclear security.A coded aperture imaging system provides a visualization solution.However,the correlation method has poor reconstruction performance for sources with low counts and for extended sources.Methods In this study,a Monte Carlo optimization-based MLEM algorithm(MC-MLEM)is proposed.The system matrix was obtained by accurate Monte Carlo simulation,so the physical effects such as mask penetration that affect the imaging process were taken into account in the MLEM algorithm.In the simulation process,the normalization of the system matrix was realized by controlling the source at different position of the source plane to have the same activity and emission angle.Results The experimental results showed that compared with the correlation method,the MC-MLEM algorithm could improve the signal-to-noise ratio and angular resolution and locate the source position quickly and accurately under low count conditions.Furthermore,the MC-MLEM algorithm could reconstruct the shape of the extended source and the expected activity ratio of cold-hot sources with large activity differences.Conclusion The MC-MLEM algorithm improved the imaging results and enhanced the reconstruction performance.

CO_(2)-promoted transfer-free growth of conformal graphene

Gaseous promotors have readily been adopted during the direct synthesis of graphene over insulators to enhance the growth quality and/or boost the growth rate.The understanding of the real functions of carbon-containing promotors has still remained elusive.In this study,we identify the critical roles of a representative CO_(2)promotor played in the direct growth of graphene.The comparative experimental trials validate CO_(2)as an effective modulator to decrease graphene nucleation density,improve growth kinetics,mitigate adlayer formation.The first-principles calculations illustrate that the generation of gas-phase OH species in CO_(2)-assisted system helps decrease the energy barriers of CH4 decomposition and carbon attachment to the growth front,which might be the key factor to allow high-quality direct growth.Such a CO_(2)-promoted strategy enables the conformal coating of graphene film over curved insulators,where the sheet resistance of grown graphene on quartz reaches as low as 1.26 kΩ·sq^(−1)at an optical transmittance of~95.8%.The fabricated endoscope lens based on our conformal graphene harvests an apoptosis of 82.8%for noninvasive thermal therapy.The work presented here is expected to motivate further investigations in the controllable growth of high-quality graphene on insulating substrates.

Survival outcomes in older patients with different stages of acute kidney injury defined by the addition of urine output criteria

To the Editor:Globally,acute kidney injury(AKI)is a common life-threatening condition.AKI is more prevalent in elderly patients,with increasing mortality rates.Compared with younger patients,older patients with AKI have a higher risk of persistent injury and poorer prognoses.[1]Older individuals often have comorbidities,increasing their susceptibility to AKI.Kidney Disease:Improving Global Outcomes(KDIGO)criteria define and stage AKI based on the higher stage of AKI defined by either serum creatinine(SCr)level or urine output(UO).[2]However,the record of UO is difficult to access in clinic,the data on the value of UO combined with SCr for AKI diagnosis or prognosis in elderly patients are lacking.Therefore,the objectives of this study were to investigate whether UO would influence the classification of AKI and improve the accuracy of prediction of the clinical prognosis in elderly patients.