An Improved Time-Domain Inverse Technique for Localization and Quantifcation of Rotating Sound Sources

The time-domain inverse technique based on the time-domain rotating equivalent source method has been proposed to localize and quantify rotating sound sources. However, this technique encounters two problems to be addressed: one is the time-consuming process of solving the transcendental equation at each time step, and the other is the difculty of controlling the instability problem due to the time-varying transfer matrix. In view of that, an improved technique is proposed in this paper to resolve these two problems. In the improved technique, a de-Dopplerization method in the time-domain rotating reference frame is frst applied to eliminate the Doppler efect caused by the source rotation in the measured pressure signals, and then the restored pressure signals without the Doppler efect are used as the inputs of the time-domain stationary equivalent source method to locate and quantify sound sources. Compared with the original technique, the improved technique can avoid solving the transcendental equation at each time step, and facilitate the treatment of the instability problem because the transfer matrix does not change with time. Numerical simulation and experimental results show that the improved technique can eliminate the Doppler efect efectively, and then localize and quantify the rotating nonstationary or broadband sources accurately. The results also demonstrate that the improved technique can guarantee a more stable reconstruction and compute more efciently than the original one.

Discovery and evaluation of a novel ^(18)F-labeled vasopressin 1a receptor PET ligand with peripheral binding specificity

The arginine-vasopressin(AVP)hormone plays a pivotal role in regulating various physiological processes,such as hormone secretion,cardiovascular modulation,and social behavior.Recent studies have highlighted the V1a receptor as a promising therapeutic target.In-depth insights into V1a receptor-related pathologies,attained through in vivo imaging and quantification in both peripheral organs and the central nervous system(CNS),could significantly advance the development of effective V1a inhibitors.To address this need,we develop a novel V1a-targeted positron emission tomography(PET)ligand,[^(18)F]V1A-2303([^(18)F]8),which demonstrates favorable in vitro binding affinity and selectivity for the V1a receptor.Specific tracer binding in peripheral tissues was also confirmed through rigorous cell uptake studies,autoradiography,biodistribution assessments.Furthermore,[^(18)F]8 was employed in PET imaging and arterial blood sampling studies in healthy rhesus monkeys to assess its brain permeability and specificity,whole-body distribution,and kinetic properties.Our research indicated[^(18)F]8 as a valuable tool for noninvasively studying V1a receptors in peripheral organs,and as a foundational element for the development of next-generation,brain-penetrant ligands specifically designed for the CNS.

Structure-activity relationship of pyrazol-4-ylpyridine derivatives and identification of a radiofluorinated probe for imaging the muscarinic acetylcholine receptor M4

There is an accumulating body of evidence implicating the muscarinic acetylcholine receptor4(M4)in schizophrenia and dementia with Lewy bodies,however,a clinically validated M4positron emission tomography(PET)radioligand is currently lacking.As such,the aim of this study was to develop a suitable M4PET ligand that allows the non-invasive visualization of M4in the brain.Structure-activity relationship studies of pyrazol-4-yl-pyridine derivates led to the discovery of target compound 12—a subtype-selective positive allosteric modulator(PAM).The radiofluorinated analogue,[18F]12,was synthesized in 28±10%radiochemical yield,>37 GBq/μmol and an excellent radiochemical purity>99%.Initial in vitro autoradiograms on rodent brain sections were performed in the absence of carbachol and showed moderate specificity as well as a low selectivity of[18F]12 for the M4-rich striatum.However,in the presence of carbachol,a significant increase in tracer binding was observed in the rat striatum,which was reduced by>60%under blocking conditions,thus indicating that orthosteric ligand interaction is required for efficient binding o f[18F]12 to the allosteric site.Remarkably,however,the presence of carbachol was not required for high specific binding in the non-human primate(NHP)and human striatum,and did not further improve the specificity and selectivity of[18F]12 in higher species.These results pointed towards significant species-differences and paved the way for a preliminary PET study in NHP,where peak brain uptake of[18F]12 was found in the putamen and temporal cortex.In conclusion,we report on the identification and preclinical development of the first radiofluorinated M4PET radioligand with promising attributes.The availability of a clinically validated M4PET radioligand harbors potential to facilitate drug development and provide a useful diagnostic tool for non-invasive imaging.

Recent advances in photochemistry for positron emission tomography imaging

As a powerful noninvasive imaging technology,positron emission tomography(PET)has been playing an important role in disease theranostics and drug discovery.The successful application of PET relies on not only the biological properties of PET tracers but also the availability of facile and efficient radiochemical reactions to enable practical production and widespread use of PET tracers.Most recently,photochemistry is emerging as a novel,mild and efficient approach to generating PET agents.In this review,we focus on the recent advances in newly developed photocatalytic radiochemical reactions,innovation on automated photochemical radiosynthesis modules,as well as implementation in late-stage radiolabeling and radio-pharmaceutical synthesis for PET imaging.We believe that this review will inspire the development of more promising radiolabeling protocols for the preparation of clinically useful PET agents.

A qualitative study of perspectives on access to tuberculosis health services in Xigaze, China

Background:Tuberculosis(TB)is a major global health threat and the leading infectious disease cause of death worldwide.Access to and retention in TB care remains a challenge for patients,particularly those living in rural and remote settings.This qualitative study explored barriers and facilitators to accessing and maintaining contact with TB care services in communities in Xigaze(Shigatse)prefecture,Xizang Autonomous Region(Tibet Autonomous Region),China from the perspective of persons impacted by TB.Methods:We conduced in-depth interviews with 23 participants impacted by TB in four rural districts in Xigaze prefecture,Xizang Autonomous Region,China between April 2019 and November 2020.Interviews were conducted in Tibetan and Mandarin,transcribed in Mandarin and translated into English.Transcripts were checked against recordings by native Tibetan and Mandarin speakers.QSR NVivo12 software was used for framework analysis guided by an access to care conceptual framework by Levesque et al.Results:Overall patients reported low awareness of and an indiferent attitude towards TB,although all reported understanding the need to adhere to treatment.Participants reported complex pathways to care,often requiring visits to multiple healthcare facilities.Some participants reported visiting traditional Tibetan medicine(TTM)providers.Participants reported various barriers to accessing care including challenges physically reaching care,out-of-pocket payments for tests,diagnostics and transport.Barriers to maintaining care included medication side efects and worry about treatment efectiveness.Enablers to accessing care identifed included knowledge or past experience with TB,integrated models of TTM and western care,supportive village doctors who conducted home visits,free TB treatment and other subsidies,as well as having family support with care and social support as barriers and facilitators to maintaining treatment.Conclusions:We identifed barriers and facilitators to accessing services in rural communities in Xigaze from the perspective of persons impacted by TB.Challenges include complex pathways to care,travel distances,wait times and low awareness.Tuberculosis care in the region could be strengthened by ongoing culturally tailored educational campaigns to increase awareness,partnerships with TTM providers,providing comprehensive treatment subsidies and strengthening the role of family members in comprehensive TB care.

Sentinel Surveillance of Schistosomiasis—China,2021

Introduction:This report analyzes the national surveillance data for schistosomiasis in 2021 to understand the current status and provide evidence for further policy actions to promote elimination.This analysis is in line with the National Surveillance Plan of Schistosomiasis,which was revised in 2020 to adapt to the new stage of moving towards elimination.Methods:Data from the 2021 national surveillance of schistosomiasis in humans,livestock,and snails were collected from 13 provincial-level administrative divisions(PLADs)and analyzed using descriptive epidemiological methodology.The antibody-positive rate and area of newly discovered and re-emergent snail habitats were calculated.Results:In 2021,a total of 31,661 local residents and 101,558 transient population were screened for antibodies using indirect hemagglutination assay(IHA).Of those who tested positive,745 local residents and 438 transient population underwent further parasitological examination,with only one stool-positive result in the transient population.Additionally,12,966 livestock were examined using the miracidia hatching test,with no positives detected.The total area of newly discovered and re-emergent snail habitats was 957,702 m^(2) and 4,381,617 m^(2),respectively.No infected snails were found using the microscopic dissection method,but six pooled snail samples were reported as positive using the loopmediated isothermal amplification method for detecting specific sequences of Schistosoma.japonicum,in Anhui and Jiangxi Provinces.Conclusions:The prevalence of schistosomiasis among humans and livestock was found to be low,however,a potential transmission risk was identified in certain areas.To reduce the risk of transmission,a comprehensive control strategy should be continued and new techniques should be implemented in the surveillance and early warning system.

磁控溅射法制备NiO_(x)及单面晶硅异质结太阳电池

NiO_(x)为宽带隙p型半导体材料,其能带结构更适于用作c-Si(n)异质结空穴传输层.为了简化问题,本文研究了NiO_(x)与Si构成的单面异质结无背场太阳电池,其结构为Al栅/ITO/NiO_(x)/Si O_(x)/c-Si(n)/Si O_(x)/Al.通过研究不同溅射参数下NiO_(x)材料的光学、电学及能带结构,分析NiO_(x)/c-Si异质结的载流子输运及界面复合机制.研究表明异质结价带失调值ΔE_(V)的势垒高度及界面态是影响电池性能的关键因素.结合实验与AFORS-HET软件仿真结果,本研究提出提高器件性能的两个途径:一是降低NiO_(x)/c-Si价带失调值ΔE_(V)及界面态密度;二是提高发射区NiO_(x)受主浓度,增强内建电场.本文为研究新型高效NiO_(x)/c-Si异质结太阳电池提供参考并指出了方向.

The Potential Distribution Prediction of Oncomelania hupensis Based on Newly Emerging and Reemergent Habitats-China,2015−2019

What is already known about this topic?Oncomelania hupensis(O.hupensis)is the only intermediate host of Schistosoma japonica.The distribution of O.hupensis is affected by a series of climate,geographical,sand ocioeconomic factors,which reflect the risk areas of schistosomiasis.What is added by this report?There were certain geographical aggregations in the potential high distribution areas of O.hupensis,which were mainly distributed in Poyang Lake area,Dongting Lake area,and the middle and the lower reaches of the Yangtze River.What are the implications for public health practice?Monitoring and forecasting the distribution of O.hupensis is conducive to improving the early warning capabilities of the potential risk of schistosomiasis transmission and progressively promoting the elimination of schistosomiasis nationwide.

Rapid Assessment on Potential Risks of Schistosomiasis Transmission—7 PLADs,China,2019 and 2021

Summary What is already known about this topic?Oncomelania hupensis(O.hupensis)and livestock are main infection sources of schistosomiasis.The schistosome infected O.hupensis and livestock’s feces are important risk factors in the transmission of schistosomiasis.What is added by this report?The potential risks of schistosomiasis transmission remain prevalent,giving an early warning to local government with information on existing transmission risks.It is expected that the effectiveness and efficiency of schistosomiasis surveillance could be improved by conducting rapid risk assessment at the beginning of transmission season.

Schistosomiasis Surveillance--China,2015−2018

Background The prevalence of schistosomiasis in China is at the lowest level in history,and sentinel surveillance sites of schistosomiasis have fully covered all epidemic areas of China.This article has analyzed the surveillance data for the last four years and can help guide the next stage of surveillance work at the national level,including the scope of surveillance,surveillance content,and surveillance methods,etc.Methods Data from the National Schistosomiasis Surveillance System were collected.The infection rate of schistosomiasis among the human population,livestock,snails,and the change of the breeding area of snails in sentinel surveillance sites for four consecutive years were analyzed,and the trends in schistosomiasis prevalence in surveillance sites were determined.Results The prevalence of schistosomiasis in all sentinel surveillance sites of China showed downward trends from 2015 to 2018 with infection rates decreasing in this time period for local human population(0.05%to 0.00%),the floating population(0.020% to 0.003%),and cattle(0.037% to 0.000%).No infected snails were found during the period.From 2015 to 2018,the total area of newly found habitats of snails(Oncomelania hupensis,O.hupensis)were 34,730 m^(2),1,367,694 m^(2),18,944 m^(2),and 50,420 m^(2),and the total area of re-emergent habitats of snails(O.hupensis)were 822,194 m^(2),1,391,779 m^(2),1,516,292 m^(2),and 1,750,558 m^(2),respectively.Conclusions and Implications for Public Health Practice The prevalence of schistosomiasis in human and livestock is going down and is sustained at a very low level,but new and re-emerging habitats of O.hupensis are new challenges regardless of the achievement of schistosomiasis control.Therefore,two actions are necessary to effectively further reduce the transmission risk of schistosomiasis:1)taking effective measures to control the source of infection of schistosomiasis;and 2)reducing the breeding areas of O.hupensis.