PLFA Analysis of Soil Microbial Community Structure in Different Forest Types

Soil soluble organic matter is an important component in the study of carbon and nitrogen cycling in terrestrial ecosystems. Soil microorganisms, as soil decomposers, participate in soil biogeochemical processes and play an important role in maintaining the balance of soil ecosystems. As a typical subtropical regional unit, Queensland, Australia, is a relatively concentrated distribution area of forests in Australia. It is very sensitive to climate change and plays an important role in Australian climate and even global climate change. Its unique natural environment and ecosystem occupy a special position in the world. However, the knowledge of available carbon and nitrogen pool and microbial activity in forest soil is still very limited. Pinus elliottii, Araucaria cunninghamii and Agathis australis are the three most important forest types in southern Queensland, Australia. In our research, the function and structural diversity of soil microbial communities of these three forest types were studied using biochemical and molecular biological methods, and the effective carbon and nitrogen pools of soil of different forest types and related microbial processes were discussed, which has important theoretical guiding significance for further research on the structure and function of soil ecosystem. The number of PLFAs in the soil of P. elliottii was 45, the number of PLFAs in the soil of Araucaria cunninghamii and Agathis australis was 39 and 35, respectively. The number and content of PLFAs monomer in P. elliottii were higher than those in the other two kinds of forest soil.

超分子化学在本科实验中的运用——六元瓜环对氨基苯酚同分异构体的新型分离方法

基于“厚基础,宽专业,大综合”的研究型实验教学思想,本文在本科教学实验中融入超分子化学理论知识,设计创新综合实验。选取六元瓜环为主体,运用超分子自组装原理实现邻、间、对氨基苯酚同分异构体选择性梯度分离,分离纯度分别达91.46%、94.16%、96.70%。整个实验中主要原料均可回收再利用,充分体现了绿色化学理念。同时,本实验使用多种化学实验的基本操作,包含薄层色谱法、液相色谱法、红外光谱法等重要分析手段对目标产物进行分离进程监测、纯度分析与结构表征,能够使学生结合基础理论知识解释实验原理、分析实验现象,进一步提升学生的研究型素养和综合运用知识的能力。

镓元素在医疗卫生领域的应用:以抗癌与抗菌为例

镓(Ga)位于元素周期表第四周期第ⅢA族,在临床疾病诊断和治疗中有重要应用。在体内,氧化还原惰性的三价镓(Ga(Ⅲ))通常作为Fe(Ⅲ)的竞争性抑制剂,破坏病变(肿瘤或感染)部位的铁稳态,从而实现抗肿瘤或抗菌的作用。在癌症诊疗方面,Ga(Ⅲ)可以通过与转铁蛋白结合或独立运输的方式进入细胞:其放射性同位素(^(67)Ga或^(68)Ga)在癌组织中富集,实现肿瘤的放射影像学诊断;而非放射性Ga则通过抑制核糖核苷酸还原酶(RR)的正常功能、引起线粒体氧化应激等途径杀灭癌细胞。在抗菌方面,Ga与Fe在生化反应中形成竞争关系,从而破坏细菌生物被膜的结构和功能,实现抗菌作用。本文从化学原理出发,介绍了Ga在癌症的诊疗和抗菌领域的应用,并对Ga基药物的发展进行了展望。

Wireless Powered IoE for 6G: Massive Access Meets Scalable Cell-Free Massive MIMO

A key challenge to the scalable deployment of the energy self-sustainability(ESS)Internet of Everything(IoE)for sixth-generation(6G)networks is juggling massive connectivity and high spectral efficiency(SE).Cell-free massive multiple-input multiple-output(CF mMIMO)is considered as a promising solution,where many wireless access points perform coherent signal processing to jointly serve the users.However,massive connectivity and high SE are difficult to obtain at the same time because of the limited pilot resource.To solve this problem,we propose a new framework for ESS IoE networks where the user activity detection(UAD)and channel estimation are decoupled.A UAD detector based on deep convolutional neural networks,an initial access scheme,and a scalable power control policy are proposed to enable the practical scalable CF mMIMO implementation.We derive novel and exact closed-form expressions of harvested energy and SE with maximum ratio(MR)processing.Using local partial minimum mean-square error and MR combining,simulation results prove that the proposed framework can serve more users,improve the SE performance,and achieve better user fairness for the considered ESS IoE networks.

Vehicle-to-Infrastructure Channel Characterization in Urban Environment at 28 GHz

Both ultra-reliable low latency and high-data-rate communications are required by connective vehicles. Millimeter wave(mm Wave) with large bandwidth is a key technology to support high-data-rate communications. In this paper, the 28 GHz wideband vehicle-to-infrastructure channel is characterized for the urban environment in a major street in Manhattan. The deployment of the transmitter and the receiver, as well as the traffic models, are selected by considering the recommendation by 3GPP TR 37.885. Ray tracing simulator with calibrated electromagnetic parameters is employed in this work to practically conduct intensive simulations. The 3D environment model is reconstructed from OpenStreetMap. The power delay profile, path loss, root-meansquare delay spread, K-factor and so on, are extracted from the calibrated simulation results. The evolution of the parameters, as well as their statistical properties, are analyzed and modeled. The work of this paper helps the researchers understand the propagation channel for designing mmWave technologies and communication system in a similar scenario.

Quantized Hybrid Precoding Design for Millimeter-Wave Large-Scale MIMO Systems

Millimeter wave(mmWave) and large-scale multiple input multiple output(MIMO) are two emerging technologies in fifth-generation wireless communication systems. The power consumption and hardware cost of radio frequency(RF) chains increase exponentially with the bit resolution of analog-to-digital converters(ADCs) and digital-to-analog converters(DACs). One promising solution is to employ few RF chains with low-bit ADCs and DACs. In this paper, we consider mmWave large-scale MIMO systems with low bits DACs and ADCs. Leveraging on the Bussgang theorem and the additive quantization noise model(AQNM), a closed-form expression of the achievable rate is derived to show the effect of the ADCs? and DACs? resolution. Moreover, an orthogonal matching pursuit(OMP) based hybrid precoding algorithm is proposed to increase the achievable rate. Our results show that the impact of DACs is more pronounced than the impact of ADCs. Furthermore, 5-bit ADCs and DACs are sufficient at the transceiver to operate without a significant performance loss.

Field trial measurement and channel modeling for reconfigurable intelligent surface

With the advantage of programmable electromagnetic properties,Reconfigurable Intelligent Surfaces(RISs)havedrawn wide attention from both industry and academia.RIS-assisted communication systems can promote hugewireless channel quality improvement and remarkable coverage enhancement.This paper proposes generalpathloss model,radiation pattern and mirror beam effect of 1-bit RIS at sub-6 GHz band.Field trails have beencarried out in outdoor and indoor deployment scenarios.The proposed model is validated through extensivesimulations and field-trial measurements.In addition,an optimized RIS phase-shit design process for the mirrorbeam elimination is proposed and validated with simulations.The proposed theoretical model and measurementresults can promote future research and application in RIS-assisted communications.

AI Assisted PHY in Future Wireless Systems: Recent Developments and Challenges

Nowadays,the rapid development of artificial intelligence(AI)provides a fresh perspective in designing future wireless communication systems.Innumerable attempts exploiting AI methods have been carried out,which results in the state-of-the-art performance in many different areas of wireless communications.In this article,we present the most recent and insightful developments that demonstrate the potentials of AI techniques in different physical layer(PHY)components and applications including channel characterization,channel coding,intelligent signal identification,channel estimation,new PHY for random access in massive machine-type communication(mMTC),massive multiple-input multiple-output(MIMO)power control and PHY resource management.Open challenges and potential future directions are identified and discussed along this research line.

Coalition Game Based Full-Duplex Concurrent Scheduling in Millimeter Wave Wireless Backhaul Network

With the development of self-interference(SI) cancelation technology, full-duplex(FD) communication becomes possible. FD communication can theoretically double the spectral efficiency. When the time slot(TS) resources are limited and the number of flows is large, the scheduling mechanism of the flows becomes more important. Therefore, the effectiveness of FD scheduling mechanism for the flows is studied in millimeter wave wireless backhaul network with the limited TS resources. We proposed a full duplex concurrent scheduling algorithm based on coalition game(FDCG) to maximize the number of flows with their QoS requirements satisfied. We transformed the problem of maximizing the number of flows with their QoS requirements satisfied into the problem of maximizing sum rate of concurrently scheduled flows in each slot. We obtained the scheduled flows with maximum sum rate in first slot by using coalition game.And then with certain restrictions, the maximum sum rate of concurrently scheduled flows can also be achieved in subsequent time slots. The simulation results show that the proposed FDCG algorithm canachieve superior performance in terms of the number of flows that meet their QoS requirements and system throughput compared with other three algorithms.

Performance of Relay Networks in Fading Environments with Dominant Specular Components

Radio propagation in dense and super dense wireless networks as well as indoor-to-outdoor picocell networks can have multiple line-of-sight or multiple specular components. The performance of a dual-hop decode-and-forward relaying system over multiple specular components fading channels(MSCC)with multiple Rayleigh distributed co-channel interferers in an interference-limited environment is investigated. The MSCC fading model is designed to allow direct and meaningful comparisons to be made between line-of-sight channels and non-line-of-sight channels, with exact parameter correspondences. Comparisons of outage and bit error performance between Nakagami-m/Rayleigh and MSCC/Rayleigh fading environments show that the MSCC model is needed to describe line-of-sight channels that cannot be accurately modeled by the Nakagami-m, or other fading models.

Optimization of Organic Mulches Thickness Improves Soil Moisture Retention under Controlled Conditions

Organic mulch can improve the moisture,chemical composition,dust,and dust suppression of soil,and beautify the environment.In view of the rapid evaporation rate and serious loss of soil water in tropical areas,this paper explored the effect of organic mulch materials with different thickness on the increase of soil water retention rate and the improvement of soil water loss caused by evaporation.Rubberwood sawdust(RWS),rubberwood bark(RWB),coconut fiber(CF),and Mulch(MC)were selected as the mulching materials.Field experiment and laboratory experiment were performed,and soil-moisture content and temperature were continuously monitored.However,from the daily measurement of water content at constant conditions(29℃±0.2℃,74%±1%air RH)in the laboratory experiment,the results of variance analysis(ANOVA)showed that there was no significant difference between the soil-water content of covered samples and bare soil(P>0.05).In the field experiments,the analysis of variance indicated significant differences in the soil-moisture content owing to the effect of the covering material(P<0.01).Mulching increased the soil-moisture content with smaller fluctuations in the deep soil compared with bare soil.The most stable soil-moisture content were achieved by RWS,RWB,CF,and MC,with thicknesses of 5,3,7,and 5 cm,respectively,compared with bare soil,and the average water contents of the 0-40 cm soil layer was 0.58%,0.01%,0.82%,and 0.93%,respectively.Vertically,the intensity of the change in soil moisture decreased gradually with increasing depth,and was more stable than that of bare soil and other treatments.Among them,the difference in water content between the adjacent gradient soil layers(the soil layers are graded every 10 cm in depth)M_(3-7)(0.011±0.004)was the smallest.It can be concluded that CF mulching materials with a thickness of 7 cm would be preferable when selecting mulching materials for controlling soil moisture in tropical cities.

A survey on user-centric cell-free massive MIMO systems

The mobile data traffic has been exponentially growing during the last several decades.This was enabled by the densification of the network infrastructure in terms of increased cell density(i.e.,Ultra-Dense Network(UDN))and/or the increased number of active antennas per Access Point(AP)(i.e.,massive Multiple-Input Multiple-Output(mMIMO)).However,neither UDN nor mMIMO will meet the increasing demand for the data rate of the Sixth Generation(6G)wireless communications due to the inter-cell interference and large quality-of-service variations.Cell-Free(CF)mMIMO,which combines the best aspects of UDN and mMIMO,is viewed as a key solution to this issue.In such systems,each User Equipment(UE)is served by a preferred set of surrounding APs cooperatively.In this paper,we provide a survey of the state-of-the-art literature on CF mMIMO.As a starting point,the significance and the basic properties of CF mMIMO are highlighted.We then present the canonical framework to discuss the essential details(i.e.,transmission procedure and mathematical system model).Next,we provide a deep look at the resource allocation and signal processing problems related to CF mMIMO and survey the up-to-date schemes and algorithms.After that,we discuss the practical issues in implementing CF mMIMO and point out the potential future directions.Finally,we conclude this paper with a summary of the key lessons learned in this field.

Research Progress on the Influence of Movement Instruction on Community Life in Patients with Coronary Heart Disease

The incidence of coronary heart disease increases year by year with the material level of our country.It has a harmful effect on the patient’s life health and quality of life.Movement Instruction is an important aspect of the secondary prevention project of cardiac rehabilitation in patients with coronary heart disease.Although it has a history of decades at inland and abroad,the present situation in China is not optimistic.Some studies have shown that the popularization and participation of cardiac rehabilitation is true and lacking.This paper sums up the relevant knowledge of coronary heart disease,coronary heart disease movement instruction and its impact on community life of patients at home and abroad,and reviews the research results of movement instruction on community rehabilitation of coronary heart disease in recent years,which provides a theoretical reference and prospect for the future research of community exercise rehabilitation of coronary heart disease.

6G无线覆盖扩展技术

根据国际电信联盟关于IMT-2030愿景,第6代移动通信系统(the 6th generation mobile networks,6G)的覆盖服务需求将从单场景覆盖向多场景覆盖扩展,6G基础设施的部署也将逐步从2D覆盖向3D覆盖扩展、从局部覆盖向全球覆盖扩展、从中低频段融合使用向更高频段按需开启.上述需求使得6G在提升容量的同时,需要进一步考虑无线覆盖扩展需求.本文针对如何在6G网络结构时空尺度跨度大、全场景业务需求差异大、超密集覆盖能耗大等关键挑战下实现容量和能效约束下的覆盖能力扩展这一重大科学问题,首先提出了面向6G无线覆盖扩展的智能柔性组网架构;其次研究了面向6G无线覆盖扩展的关键技术,包括面向6G广域覆盖的多维立体空天地覆盖扩展技术、面向深度覆盖的超密集异构覆盖扩展技术和面向6G平滑度覆盖的超高速移动覆盖扩展技术;接着分析了基于语义通信的覆盖扩展技术;最后给出了6G全场景无线覆盖扩展仿真验证,通过定义6G无线覆盖扩展技术指标体系,进行了典型场景的覆盖性能仿真验证.

Coherent beam combining of two all‑PM thulium‑doped fiber chirped pulse amplifiers

In this paper,we report a coherent beam combining(CBC)system that involves two thulium-doped all-polarization maintaining(PM)fiber chirped pulse amplifiers.Through phase-locking the two channels via a fiber stretcher by using the stochastic parallel gradient descent(SPGD)algorithm,a maximum average power of 265 W is obtained,with a CBC efficiency of 81%and a residual phase error of λ/17.After de-chirping by a pair of diffraction gratings,the duration of the combined laser pulse is compressed to 690 fs.Taking into account the compression efficiency of 90%and the main peak energy proportion of 91%,the corresponding peak power is calculated to be 4 MW.The laser noise characteristics before and after CBC are examined,and the results indicate that the CBC would degrade the low frequency relative intensity noise(RIN),of which the integration is 1.74%in[100 Hz,2 MHz]at the maximum combined output power.In addition,the effects of the nonlinear spectrum broadening during chirped pulse amplification on the CBC efficiency are also investigated,showing that a higher extent of pulse stretching is effective in alleviating the spectrum broadening and realizing a higher output power with decent combining efficiency.

基于网络药理学探讨桃红四物汤治疗阿尔茨海默症的主要有效成分及其作用机制

桃红四物汤(Taohong Siwu Decoction,THSWD)是活血化瘀的经典中药方剂,本研究利用网络药理学筛选THSWD潜在活性成分,探讨其治疗阿尔茨海默症的核心作用靶点和信号通路。首先,通过TCMSP和SEA数据库,筛选THSWD的活性成分及其作用靶点,共获得25个活性化合物(active compounds,ACs)和478个活性成分靶点;通过TTD、Dis Ge NET、Drug Bank、GAD和Gene Cards数据库共获得阿尔茨海默症疾病靶点724个。寻找活性成分作用靶点和疾病相关靶点的交集,共获得64个靶点(overlapping targets,OTs)。然后,构建25个ACs和64个OTs相互关系网络,获得21个一级关键化合物(first level key compound,FKCs)。通过对64个OTs进行PPI分析,获得33个核心靶点(core targets,CTs),并对这33个CTs进行KEGG聚类分析,获得排名靠前73条通路。最后,利用Cytoscape 3.7.2软件绘制“21个FKCs-33个CTs-73条通路”网络关系图,根据拓扑参数进行选择,进一步获得19个二级关键化合物(second key components,SKCs)。对“19个SKCs-33个CTs-73条通路”进行网络的分析与提取,最终构建得到THSWD干预阿尔茨海默症“6种单味药-8种潜在活性成分-13个核心作用靶点-54条信号通路”的网络图谱。研究结果为阐明THSWD的药效物质基础和进一步研究THSWD治疗阿尔茨海默症的作用机制和临床应用提供了新思路。

Third-Trimester Spontaneous Uterine Rupture After Ultrasound-Guided High-Intensity Focused Ultrasound Therapy

To editor:Uterine rupture,despite its low incidence,is a severe obstetric complication that is associated with adverse maternal and neonatal outcomes.Previous uterine scarring is a known risk factor for uterine rupture.Uterine scars can form from hysterotomy after abdominal/hysteroscopic myomectomy,cesarean delivery,or hysteroscopic surgery.Over the past few decades,ultrasound-guided high-intensity focused ultrasound(USgHIFU)has emerged as a non-invasive therapeutic tool and has found wide application for the safe and effective management strategy of uterine fibroids and adenomyosis.

Construction of a Competency Evaluation Indicator System for Emergency Response Staff in Disease Control and Prevention Institutions ——China, 2023

Summary What is already known about this topic?Currently,there is no established scientific standard to guide disease control and prevention organizations in the selection of emergency response personnel.Given the growing risk of significant infectious disease outbreaks,it is imperative to develop an evaluation system for assessing emergency response capabilities.

First Case Report of Cystic Echinococcosis Caused by G7 Genotype Echinococcus intermedius Confirmed by Genetic Sequencing—Southern China,December 2023

What is already known about this topic?Echinococcosis exhibits a global distribution.In China,the primary endemic area is the northwest region.In December 2023,we documented a case of echinococcosis in an individual lacking any travel or residential history in endemic regions.What is added by this report?This is the first laboratory-confirmed case of hepatic echinococcosis reported in Guangdong Province,associated with the G7 genotype of Echinococcus granulosus(E.granulosus).The most probable mode of transmission is a local infection resulting from E.granulosus introduced from endemic regions.What are the implications for public health practice?As the circulation of agricultural products increases,it is essential to enhance the quarantine and management of livestock from epidemic areas to prevent and control the spread of echinococcosis to non-epidemic regions.

Targeting cancer stem cell pathways for cancer therapy

Since cancer stem cells(CSCs)were first identified in leukemia in 1994,they have been considered promising therapeutic targets for cancer therapy.These cells have self-renewal capacity and differentiation potential and contribute to multiple tumor malignancies,such as recurrence,metastasis,heterogeneity,multidrug resistance,and radiation resistance.The biological activities of CSCs are regulated by several pluripotent transcription factors,such as OCT4,Sox2,Nanog,KLF4,and MYC.In addition,many intracellular signaling pathways,such as Wnt,NF-κB(nuclear factor-κB),Notch,Hedgehog,JAK-STAT(Janus kinase/signal transducers and activators of transcription),PI3K/AKT/mTOR(phosphoinositide 3-kinase/AKT/mammalian target of rapamycin),TGF(transforming growth factor)/SMAD,and PPAR(peroxisome proliferator-activated receptor),as well as extracellular factors,such as vascular niches,hypoxia,tumor-associated macrophages,cancer-associated fibroblasts,cancer-associated mesenchymal stem cells,extracellular matrix,and exosomes,have been shown to be very important regulators of CSCs.Molecules,vaccines,antibodies,and CAR-T(chimeric antigen receptor T cell)cells have been developed to specifically target CSCs,and some of these factors are already undergoing clinical trials.This review summarizes the characterization and identification of CSCs,depicts major factors and pathways that regulate CSC development,and discusses potential targeted therapy for CSCs.