Research of Protected Cultivation Techniques of Toona sinensis on Mountain Slopes

In order to prolong the supply period and increase the economic value of Toona sinensis,the protected cultivation of T. sinensis was carried out on mountainous slope to achieve stagger-season planting and the year round supply. The results showed that in late October to midNovember,the temperature was moderate( 1-10℃) and suitable for the lifting of seedlings and temporary planting dormancy. The line spacing of rooted seedlings in greenhouse was( 22-24) cm ×( 4-5) cm and planting density was 900 000-1 200 000 seedlings/ha. The line spacing of seedlings was( 14-13) cm ×( 3-4) cm and planting density was 1 950 000-2 100 000 seedlings/ha. T. sinensis began to sprout at 8-10℃ and stretch at 10-12℃. When the temperature was stable at 14℃ or above,T. sinensis started bolting and emerging leaves. The terminal buds sprouted in 40-50 d for the T. sinensis planted in greenhouse with the day temperature of 15-22℃ and night temperature over 10℃; the terminal buds sprouted in about 15 d for those planted in the greenhouse with day temperature of 20-25℃ and night temperature over 10℃. T. sinensis could be picked 3 times when planted in greenhouse,and the yield was about 24 720 kg/ha.

Hypoxic/ischemic preconditioning attenuate PKCδ-medi-ated injury in patients and mice with cerebral infarction

Objective:cerebral ischemic/hypox-ic preconditioning(I/HPC)is an endogenous strategy in which brief periods of sublethal ischemia/hypoxia render neural tissues resistant to subsequent ischemic/hypoxic damage.This phenomenon has been found in the brain,heart,liver,intestine,muscle,kidneys,and lung.How-ever,whether HPC has a protective effect on secondary cerebral ischemic injury or protein kinase Cδ(PKCδ)within ischemic patients and animal models is still un-clear.Methods:using a hypoxic preconditioned mouse model and a middle cerebral artery occlusion mouse mod-el,combined with 2,3,5-triphenyl tetrazolium chloride(TTC)staining,SDS-polyacrylamide gel electrophoresis(SDS-PAGE),and Western blot,we observed changes in infarction size,density,edema ratio,and changes in PKCδand membrane translocation within the ischemic cortex of the middle cerebral artery occlusion(MCAO)mice.Results:HPC can attenuate neurological deficits and cerebral ischemic injuries of mice following MCAO,including decreases in infarct size,edema ratio,densities of infarct area,and neuron loss.In addition,HPC inhib-its PKCδmembrane translocation in the penumbra of the MCAO-induced ischemic cortex.We found that admin-istration of PKCδ-specific inhibitor dV1-1 mimics the neuroprotective effects of HPC,and nonisoform-specif-ic activation of PKC can partially abolish HPC-induced neuroprotection.Ischemic preconditioning decreased the levels of PKCδin the serum of patients with cerebral in-farction and reduced the cerebral nerve damage caused by ischemia.Conclusion:hypoxic/ischemic precondi-tioning attenuates PKCδ-mediated injury in patients and mice.These findings enrich our understanding of the sig-nal transduction mechanism underlying cerebral HPC and provide clues to developing medicine against ischemia/hypoxia-induced cerebral injuries.

A hybrid-model optimization algorithm based on the Gaussian process and particle swarm optimization for mixed-variable CNN hyperparameter automatic search

Convolutional neural networks(CNNs)have been developed quickly in many real-world fields.However,CNN’s performance depends heavily on its hyperparameters,while finding suitable hyperparameters for CNNs working in application fields is challenging for three reasons:(1)the problem of mixed-variable encoding for different types of hyperparameters in CNNs,(2)expensive computational costs in evaluating candidate hyperparameter configuration,and(3)the problem of ensuring convergence rates and model performance during hyperparameter search.To overcome these problems and challenges,a hybrid-model optimization algorithm is proposed in this paper to search suitable hyperparameter configurations automatically based on the Gaussian process and particle swarm optimization(GPPSO)algorithm.First,a new encoding method is designed to efficiently deal with the CNN hyperparameter mixed-variable problem.Second,a hybrid-surrogate-assisted model is proposed to reduce the high cost of evaluating candidate hyperparameter configurations.Third,a novel activation function is suggested to improve the model performance and ensure the convergence rate.Intensive experiments are performed on image-classification benchmark datasets to demonstrate the superior performance of GPPSO over state-of-the-art methods.Moreover,a case study on metal fracture diagnosis is carried out to evaluate the GPPSO algorithm performance in practical applications.Experimental results demonstrate the effectiveness and efficiency of GPPSO,achieving accuracy of 95.26%and 76.36%only through 0.04 and 1.70 GPU days on the CIFAR-10 and CIFAR-100 datasets,respectively.

锦屏深地核天体物理实验(JUNA)的首个结果:^(25)Mg(p,γ)^(26)Al反应92 keV共振的精确测量

银河系星际介质中的^(26)Al衰变发射的1.809 MeVγ射线是γ天文学的主要观测对象之一,是银河系中正在进行核合成的关键证据,也为核合成理论与天文观测进行比较提供一个重要基准.在大质量恒星氢燃烧中,^(26)Al主要通过^(25)Mg(p,γ)^(26)Al反应产生,因此该反应在1.809 MeVγ射线研究中起着重要的作用.在天体环境温度为0.1 GK左右时,^(25)Mg(p,γ)^(26)Al天体物理反应率主要由92 keV共振俘获过程决定.作为在中国锦屏地下实验室(CJPL)中锦屏核天体物理实验(JUNA)装置上进行的首个实验,本工作对^(25)Mg(p,γ)^(26)Al反应的92 keV共振进行了精确的实验测量,得到了该共振的共振强度为ωγ=(3.80.3)10^(-10) eV,基态分支比为f0=0.660.04.与之前的工作相比,本工作大大提高了92 keV共振数据的精度.基于测量的92 keV共振参数和以前的间接测量结果,得到了精度最高的^(25)Mg(p,γ)^(26)Al天体物理反应率.结果表明,在0.1 GK左右时,新的反应率比REACLIB数据库中采用的反应率大2.4倍,这将导致^(26)Al和宇宙1.809 MeVγ射线的产额提高.同时,新反应率也将对理解太阳系的形成、球状星团的元素丰度反相关等问题提供重要的数据支撑.

Progress of Jinping Underground laboratory for Nuclear Astrophysics(JUNA)

Jinping Underground laboratory for Nuclear Astrophysics(JUNA) will take the advantage of the ultra-low background of CJPL lab and high current accelerator based on an ECR source and a highly sensitive detector to directly study for the first time a number of crucial reactions occurring at their relevant stellar energies during the evolution of hydrostatic stars. In its first phase, JUNA aims at the direct measurements of^(25)Mg(p,γ)^(26)Al,^(19)F(p,α)^(16)O,^(13)C(α,n)^(16)O and ^(12)C(α,γ)^(16)O reactions. The experimental setup,which includes an accelerator system with high stability and high intensity, a detector system, and a shielding material with low background, will be established during the above research. The current progress of JUNA will be given.

A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

In 2014, the National Natural Science Foundation of China(NSFC) approved the Jinping Underground Nuclear Astrophysics laboratory(JUNA) project, which aims at direct cross-section measurements of four key stellar nuclear reactions right down to the Gamow windows. In order to solve the observed fluorine overabundances in Asymptotic Giant Branch(AGB) stars, measuring the key ^(19)F( p,α)^(16)O reaction at effective burning energies(i.e., at Gamow window) is established as one of the scientific research sub-projects. The present paper describes this sub-project in details, including motivation, status, experimental setup, yield and background estimation, aboveground test, as well as other relevant reactions.

天体Ⅰ型X射线暴中的核物理

X射线暴(X-ray burst)是指天体的X射线亮度突然增强10~50倍的天文现象.它是发生在由一颗中子星(或者黑洞)和一颗伴随的“捐赠者”伴星(通常为红巨星)所构成的密近双星系统里的剧烈核过程.作为宇宙中发生最频繁的热核爆炸事件,X射线暴已广泛为国际上众多基于卫星的X射线观测站所观测和研究,其中包括2017年中国发射的“慧眼”硬X射线调制望远镜.核物理学家需要提供精确的核物理输入量,例如原子核质量、衰变寿命、核反应率等,结合天体物理模型,进而深入理解X射线暴中天文观测到的光变曲线、双星系统相应的天体物理环境参数,以及爆炸灰烬中的核素丰度分布等重要科学问题.本文针对天体Ⅰ型X射线暴中关键核反应研究进行了系统的阐述,详细介绍了X射线暴中的一些主要核合成过程,以及所需的关键核物理输入量,总结了相关研究方向的具体目标,为研究者指出了未来可能的研究方向.

Safety of endovascular therapy for symptomatic intracranial artery stenosis:a national prospective registry

Introduction The safety outcomes of endovascular therapy for intracranial artery stenosis in a real-world stetting are largely unknown.The Clinical Registration Trial of Intracranial Stenting for Patients with Symptomatic Intracranial Artery Stenosis(CRTICAS)was a prospective,multicentre,real-world registry designed to assess these outcomes and the impact of centre experience.Methods 1140 severe,symptomatic intracranial arterial stenosis(ICAS)patients treated with endovascular therapy were included from 26 centres,further divided into three groups according to the annual centre volume of intracranial angioplasty and stent placement procedures over 2 years:(1)high volume for≥25 cases/year;(2)moderate volume for 10–25 cases/year and(3)low volume for<10 cases/year.Results The rate of 30-day stroke,transient ischaemic attack or death was 9.7%(111),with 5.4%,21.1%and 9.7%in high-volume,moderate-volume and low-volume centres,respectively(p<0.05).Multivariable logistic regression confirmed high-volume centres had a significantly lower primary endpoint compared with moderate-volume centres(OR=0.187,95%CI:0.056 to 0.627;p≤0.0001),while moderate-volume and low-volume centres showed no significant difference(p=0.8456).Conclusion Compared with the preceding randomised controlled trials,this real-world,prospective,multicentre registry shows a lower complication rate of endovascular treatment for symptomatic ICAS.Non-uniform utilisation in endovascular technology,institutional experience and patient selection in different volumes of centres may have an impact on overall safety of this treatment.

Brugada syndrome:a fatal disease with complex genetic etiologies–still a long way to go

Brugada syndrome(BrS)is an arrhythmogenic disorder which was first described in 1992.This disease is a channelopathy characterized by ST-segment elevations in the right precordial leads and is susceptible to sudden death.BrS is a fatal disease with gender and age preferences.It occurs mainly in young male subjects with a structurally normal heart and silently progresses to sudden death with no significant symptoms.The prevalence of BrS has been reported in the ranges of 5-20 per 10000 people.The disease is more prevalent in Asia.Nowadays,numerous variations in 23 genes have been linked to BrS since the first gene SCN5A has been associated with BrS in 1998.Not only can clinical specialists apply these discoveries in risk assessment,diagnosis and personal medicine,but also forensic pathologists can make full use of these variations to conduct death cause identification.However,despite the progress in genetics,these associated genes can only account for approximately 35%of the BrS cases while the etiology of the remaining BrS cases is still unexplained.In this review,we discussed the prevalence,the genes associated with BrS and the application of molecular autopsy in forensic pathology.We also summarized the present obstacles,and provided a new insight into the genetic basis of BrS.

A method for determination of deuterium impurity in the helium beam

Both the LUNA(Laboratory for Underground Nuclear Astrophysics)collaboration in Europe and the JUNA(Jinping Underground Laboratory for Nuclear Astrophysics)collaboration in China are planning to study the key reactions during the stellar helium burning at or close to their stellar energies in deep underground laboratories[1-3].The success of such experiments relies on the ratio of the reaction

The forensic pathological analysis of sport-related sudden cardiac death in Southern China

Studies regarding sport-related sudden cardiac death(SCD)mainly focus on competitive ath-letes;similar data are rare in the general population,especially in China.We conducted a retrospective study(from September 1998 to August 2013)to investigate the aetiological distribution and epidemiological features of sport-related SCD in Southern China.Selections of cases are based on details,and two subgroups were established:one was the sport-related SCD group,and the other was the disease-free accident victims group which was matched with the sport-related SCD group in gender,age and year of death.Among the 3770 sudden-death cases,1656 cases were SCD cases.A total of 65 cases(57 males)out of 1656 SCD cases were sport-related.The age range of the 65 sport-related SCD cases was from 12 to 68 years old with a mean(35.92±14.23)years old.Only two of these cases were competitive athletes.The most common circumstances of the 65 sport-related SCD cases were heavy physical labour(46.15%)and running(30.77%).The three leading forensic diag-noses were the coronary atherosclerotic disease(CAD,28 cases),cardiomyopathy(CM,14 cases)and sudden unexplained death(7 cases).CM was the most common forensic diagno-sis in those?35 years old,while CAD was the most common one in those>35 years old.Left anterior descending in which atherosclerotic plaques was most commonly found was the principal artery branch associated with sport-related SCD.There was a statistically signifi-cant difference in the weight of hearts between the 65 sport-related SCD cases and 65 dis-eases-free accidental cases.This study highlights the need to attract public attention to sport-related SCD and to issue a prevention strategy to the public,and to make the SCD-related genetic sequencing a routine tool in both forensic pathological examination and clinic screening.