Classification of dendrocola nematode-trapping fungi

Pine wilt disease,caused by Bursaphelenchus xylophilus and Bursaphelenchus mucnatus,is a serious quarantined disease.Arboreal nematode-trapping fungi of P inus spp.are effective predators on nematodes and have strong host adaptability.The development of these fungal resources may be an effective way to control pine wood nematodes.We collected 515 samples of pine wilt disease from the areas of Ninghai City(Zhejiang province),Shuangbai County(Yunnan province),and Daxing'anling(Heilongjiang province),China.Through isolation,culture and identification,6 species of nematode-trapping fungi(A rthrobotrys cladodesr,A.oligospora,A.musiformis,A.dendroides,Dactylellina ellipsospora,Monacrosporium thaumasium)were identified for predation against B.xylophilus,and 9 species(Arthrobotrys dactyloides,A.cladodes r A.oligospora A.dendroides,Dactylellina ellipsospora,Dactylella asthenopaga,D.leptospora,Arthrobotrys superba,Monacrosporium drechseri)were identified for predation against B.mucnatus.This study provides information in the classification of arboreal predator nematodes and provides an important basis for future biological control of pine wood nematodes.

Growth and decline of arboreal fungi that prey on Bursaphelenchus xylophilus and their predation rate

Pine wilt disease caused by pine wood nema-todes is a deadly disease of the genus Pinus requiring strong quarantine measures.Since its discovery,it has been widely distributed throughout the world.China is one of the coun-tries with a severe rate of infections due to its abundant pine resources.In this study,nematode-trapping fungi were collected from pine trees in Ninghai City,Zhejiang Prov-ince,which is the key area of pine wilt control in Febru-ary,May,September,October and November.The results showed that nematode-trapping fungi of pine are abundant,especially the number and species detected in each month and are quite different;species of fungi in July,Septem-ber and November were more numerous and had higher separation rates.The dominant species in November was Arthrobotrys oligospora followed by Arthrobotrys cladodes;July and September it was A.cladodes.In each part of the tree,A.cladodes was the most widely distributed with a high separation rate.Therefore,it is the dominant fungal species in the area.Arboreal Bursaphelenchus xylophilus-trapping fungi are dependent on pine wood nematodes,and none were isolated from healthy pine trees.More arboreal B.xylophilus-trapping fungi were found under the bark than in the xylem.There is a close relationship between arboreal B.xylophilus-trapping fungi and pine wood nematodes.How to make use of these resources to reduce the damage of pine wood nematode fusarium is the focus of future research.

Test and Correction of CUACE Model in Air Quality Forecast in the Qinghai-Tibet Plateau:A Case Study of Xining City

Based on the data of national monitoring points of air pollution control in Xining from 2015 to 2017,the air quality prediction of CUACE model in Xining was tested by using the method of national environmental meteorological numerical model prediction quality inspection and evaluation.The results show that the prediction accuracy of the CAUCE model for the primary pollutants in Xining region during 2015-2017 was generally higher in the winter half year,and the maximum appeared in November 2016.The prediction accuracy in 24,48 and 72 h was more than 70%.The prediction accuracy of the model in the summer half year was low.The primary pollutants in Xining area were PM_(10),PM_(2.5),O_(3),NO_(2) and CO.The prediction accuracy of PM_(10) was the highest,followed by PM_(2.5),while that of O 3 was the lowest.TS score of 24-hour forecast of light pollution was greater than 0 in the winter half year,and it was the highest in December when the unreported rate was also the highest;the empty report rate existed all year round,and was the highest from May to June.Forecast deviation was greater than 0 in the winter half year,and the maximum appeared in January.The 48-hour and 72-hour model forecast were consistent with the 24-hour forecast.The forecast effect of the model on sudden pollution weather was poor,and moderate pollution,severe pollution,and serious pollution weather occurred less frequently in Xining region,so there was fewer model forecast of this kind of pollution.Besides,among the 24-,48-and 72-hour forecast values of the model,there were many empty reports of this kind of pollution,and the empty report rate was high.

基于PT对称的声波超前/延迟线

低损耗、长带宽、时间可控的声波延迟线在音频、射频、声表面波信号处理等领域具有非常广泛的应用,然而设计满足上述三点特性的声延迟线是一项极具挑战性的工作.近年来,量子力学中的宇称时间(parity-time,PT)对称概念被引入到声学系统中,其散射矩阵在特殊点处的实数本征值揭示了声波在此类系统中可实现宽带的无损传输,且传输相位可调.本文设计了一种由一对PT对称的导纳超表面及夹在中间的等效声学介质组成的声学系统,通过设置导纳超表面参数调节其工作机制,从而实现了两类互补的特殊点.其中防反射层模式下的特殊点导致了一种声波延迟线的形成,而相干完美吸收-激“声”模式下的特殊点则用于设计一种罕见的声波超前线.由于此声学损耗-增益超表面在自然界中是不存在的,本文利用可主动控制的电热声碳纳米管薄膜来模拟它.仿真结果表明,PT对称系统是实现低损耗、长带宽且时间可控的声波超前/延迟线的优良载体,其应用可扩展至包括光学、力学、弹性波等诸多波动领域.

Manipulation of invisible cloaking in PT-symmetric thermoacoustic dimer

Making the propagation of sound waves immune to interference from obstacles with high transmission efficiency is a long-term pursuit in acoustic science and engineering.Recent proposal pointed out that perfect transmission through obstacles can be achieved by deploying a bulky gain-loss distribution in parity-time(PT)symmetry.Here we demonstrate a modified methodology to achieve the extraordinary physical property of acoustic cloaking accompanied by perfect transmission at the exceptional points(EPs).Systematically probing reveals two complementary solutions of EPs corresponding to acoustic cloaking,in the system composed of an equivalent medium slab sandwiched by a pair of PT-symmetric admittance metasurfaces.To model the crucial acoustic gains that are not present in nature,we employ actively controlled ultra-thin carbon nanotube dimer films to mimic admittance metasurfaces perfectly via thermoacoustic effect,and manipulate acoustic cloaking over a wide frequency band in experiments.This divergent strategy releases restrictions on the operating frequency,shape and size of the obstacle,which can be applied to acoustic sensing,directional imaging,and other related wave disciplines.

Risk factors associated with hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation

Hemorrhagic cystitis(HC)is a common complication of allogeneic hematopoietic stem cell transplantation(HSCT).The incidence is about 7%to 68%,and some patients have to suffer a long period of frequent,urgent,and painful urination,which brings great pain.This study aimed to analyze risk factors of HC and its effect on patient survival.We collected the medical records of 859 patients who underwent HSCT at our hospital between August 2016 and August 2020.Patients with and without HC were matched using propensity score matching at a 1:1 ratio based on sex,age,and diagnosis,and logistic regression analyses were used to identify factors associated with HC.We used Kaplan–Meier curves to analyze the survival rates of patients in the HC and non-HC groups.We also analyzed the relationship between BK viral load and the occurrence of HC using receiver operating characteristic curve(ROC)analysis.After propensity score matching,there were 131 patients each in the HC and non-HC groups.In the HC group,89 patients(67.9%)had mild HC(stage II°)and 43(32.1%)had severe HC(stage III–IV).The median interval between stem cell transplantation and HC development was 31(3–244)days.Univariate analysis indicated that donor age,hematopoietic stem cell source,HLA,acute graft-versus-host disease,busulfan,anti-thymocyte globulin(ATG),total body irradiation,cytomegalovirus(CMV)(urine),and BK polyomavirus(BKV)(urine)were significantly associated with HC.ATG,CMV(urine),and BKV(urine)were independent risk factors for HC based on the multivariate analysis.The Kaplan–Meier survival analysis showed no significant difference between the HC and non-HC groups(P=0.14).The 1-and 2-year survival rates in the HC group were 78.4%and 69.6%,respectively,and the corresponding rates in the non-HC group were 84.4%and 80.7%,respectively.ROC analysis indicated that a urine BKV load of 1×10^(7) copies/mL was able to stratify the risk of HC.In conclusion,when the BKV load is>1×10^(7),we needtobe aware of the potential for the development of HC.