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Highly-sensitive wafer-scale transfer-free graphene MEMS condenser microphones

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Microsystems & Nanoengineering 2024年第1期10卷 267-275页

作者： Roberto Pezone Sebastian Anzinger gabriele baglioni Hutomo Suryo Wasisto Pasqualina M.Sarro peter g.Steeneken Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands Infineon Technologies Ag Am Campeon 1-15Neubiberg 85579Germany Kavli Institue of Nanoscience Department of Quantum NanoscienceDelft University of TechnologyDelftthe Netherlands Department of Precision and Microsystems Engineering(PME) Delft University of TechnologyDelftThe Netherlands

Since the performance of micro-electro-mechanical system(MEMS)-based microphones is approaching fundamental physical,design,and material limits,it has become challenging to improve *** works have demonstrated graphene’s suitability as a microphone *** potential for achieving smaller,more sensitive,and scalable onchip MEMS microphones is yet to be *** address large graphene sizes,graphene-polymer heterostructures have been proposed,but they compromise performance due to added polymer mass and *** work demonstrates the first wafer-scale integrated MEMS condenser microphones with diameters of 2R=220-320μm,thickness of 7 nm multi-layer graphene,that is suspended over a back-plate with a residual gap of 5μ*** microphones are manufactured with MEMS compatible wafer-scale technologies without any transfer steps or polymer layers that are more prone to contaminate and wrinkle the *** designs,all electrically integrated are fabricated and characterized allowing us to study the effects of the introduction of a back-plate for capacitive *** devices show high mechanical compliances C_(m)=0.081-1.07μmPa^(−1)(10-100×higher than the silicon reported in the state-of-the-art diaphragms)and pull-in voltages in the range of 2-9.5 *** addition,to validate the proof of concept,we have electrically characterized the graphene microphone when subjected to sound *** estimated sensitivity of S_(1kHz)=24.3-321 mV Pa^(−1)for a V_(bias)=1.5 V was determined,which is 1.9-25.5×higher than of state-of-the-art microphone devices while having a~9×smaller area.

关键词： transfer plate approaching

Organochlorides Mediate Oxidation Reactions Induced by Low Dose Ionizing Radiation

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CCS Chemistry 2024年第7期6卷 1712-1720页

作者： Juncheng Liu Tobias g.brevé bing Xu peter-Leon Hagedoorn Antonia g.Denkova Rienk Eelkema Department of Radiation Science and Technology Delft University of Technology2629 JB Delft Department of Chemical Engineering Delft University of Technology2629 HZ Delft Department of biotechnology Delft University of Technology2629 HZ Delft

The controlled release of drugs using local ionizing radiation presents a promising approach for targeted cancer treatment,particularly when applied in concurrent *** these approaches,radiation-generated reactive species often play an important ***,the reactive species that can be used to trigger release have low yield and lack ***,we demonstrate the generation of highly oxidative species when aqueous solutions containing low concentrations of organochlorides(such as chloroform)are irradiated with ionizing radiation at therapeutically relevant *** reactive species were identified as peroxyl radicals,which formed in a reaction cascade between organochlorides and aqueous *** employed stilbene-based probes to investigate the oxidation process,showing double bond oxidation and *** translate this reactivity into a radiation-sensitive material,we synthesized a micelle-forming amphiphilic block copolymer that has stilbene as the linker between two *** exposure to ionizing radiation,the oxidation of stilbene led to the cleavage of the polymer,which induces the dissociation of the block-copolymer micelles and the release of loaded drugs.

关键词： drug delivery micelles radiation chemistry reactive oxygen species ionizing radiation reaction mechanisms

Skeletal muscle as a molecular and cellular biomarker of disease progression in amyotrophic lateral sclerosis:a narrative review

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Neural Regeneration Research 2024年第4期19卷 747-753页

作者： peter H.King Department of Neurology and Center for Neurodegeneration and Experimental Therapeutics The University of Alabama at BirminghamBirminghamALUSA birmingham Veterans Affairs Medical Center BirminghamALUSA

Amyotrophic lateral sclerosis is a fatal multisystemic neurodegenerative disease with motor neurons being a primary *** progressive weakness is a hallmark feature of amyotrophic lateral sclerosis,there is considerable heterogeneity,including clinical presentation,progression,and the underlying triggers for disease *** on longitudinal studies with families harboring amyotrophic lateral sclerosis-associated gene mutations,it has become apparent that overt disease is preceded by a prodromal phase,possibly in years,where compensatory mechanisms delay symptom *** 85-90%of amyotrophic lateral sclerosis is sporadic,there is a strong need for identifying biomarkers that can detect this prodromal phase as motor neurons have limited capacity for *** Food and Drug Administration-approved therapies work by slowing the degenerative process and are most effective early in the *** muscle,including the neuromuscular junction,manifests abnormalities at the earliest stages of the disease,before motor neuron loss,making it a promising source for identifying biomarkers of the prodromal *** accessibility of muscle through biopsy provides a lens into the distal motor system at earlier stages and in real *** advent of“omics”technology has led to the identification of numerous dysregulated molecules in amyotrophic lateral sclerosis muscle,ranging from coding and non-coding RNAs to proteins and *** technology has opened the door for identifying biomarkers of disease activity and providing insight into disease mechanisms.A major challenge is correlating the myriad of dysregulated molecules with clinical or histological progression and understanding their relevance to presymptomatic phases of *** are two major goals of this *** first is to summarize some of the biomarkers identified in human amyotrophic lateral sclerosis muscle that have a clinicopathological correlation with disease activi

关键词： amyotrophic lateral sclerosis biomarkers clinicopathological correlation disease progression muscle biomarkers neurogenic atrophy neuromuscular junction non-coding RNAs presymptomatic stages skeletal muscle SOD1g93A mouse model

A product version of the Hilton-Milner-Frankl theorem

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Science China Mathematics 2024年第2期67卷 455-474页

作者： peter Frankl Jian Wang Alfréd Rényi Institute of Mathematics Hungarian Academy of SciencesBudapest H-1053Hungary Department of Mathematics Taiyuan University of TechnologyTaiyuan 030024China

Two families F and g of k-subsets of {1, 2,..., n} are called non-trivial cross t-intersecting if|F ∩ g|≥t for all F ∈ F, g ∈ g and | ∩ {F : F ∈ F}| < t, | ∩ {g : g ∈ g}| < t. In the present paper,we determine... 详细信息

Two families F and g of k-subsets of {1, 2,..., n} are called non-trivial cross t-intersecting if|F ∩ g|≥t for all F ∈ F, g ∈ g and | ∩ {F : F ∈ F}| g : g ∈ g}| g families of k-subsets of{1, 2,..., n} for n≥4(t + 2)2k2, k≥5, which is a product version of the Hilton-Milner-Frankl theorem.

关键词： extremal set theory cross t-intersecting family product version non-trivial

Identific tion of quantitative trait loci and associated candidate genes for pregnancy success in Angus–brahman crossbred heifers

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Journal of Animal Science and biotechnology 2024年第1期15卷 162-170页

作者： Quinn A.Hoorn gabriel A.Zayas Eduardo E.Rodriguez Laura M.Jensen Raluca g.Mateescu peter J.Hansen Department of Animal Sciences Donald Henry Barron Reproductive and Perinatal Biology Research Programand the Genetics InstituteUniversity of FloridaGainesvilleFLUSA School of Applied Systems biology La Trobe UniversityBundooraVIC 3083Australia

background In beef cattle, more than 50% of the energy input to produce a unit of beef is consumed by the female that produced the calf. Development of genomic tools to identify females with high genetic merit for reproductive function could increase the profitability and sustainability of beef *** genome-wide association studies(gWAS) were performed using a single-step genomic best linear unbiased prediction approach on pregnancy outcome traits from a population of Angus–brahman crossbred heifers. Furthermore, a validation gWAS was performed using data from another farm. Heifers were genotyped with the bovine ggP F250 array that contains 221,077 SNPs. In the discovery population, heifers were bred in winter breeding seasons involving a single round of timed artificial insemination(AI) followed by natural mating for 3 months. Two phenotypes were analyzed: pregnancy outcome to first-service AI(PAI;n = 1,481) and pregnancy status at the end of the breeding season(PEbS;n = 1,725). The heritability was estimated as 0.149 and 0.122 for PAI and PEbS, respectively. In the PAI model, one quantitative trait locus(QTL), located between 52.3 and 52.5 Mb on bTA7, explained about 3% of the genetic variation, in a region containing a cluster of γ-protocadherin genes and SLC25A2. Other QTLs explaining between 0.5% and 1% of the genetic variation were found on bTA12 and 25. In the PEbS model, a large QTL on bTA7 was synonymous with the QTL for PAI, with minor QTLs located on bTA5, 9, 10, 11, 19, and 20. The validation population for pregnancy status at the end of the breeding season were Angus–brahman crossbred heifers bred by natural mating. In concordance with the discovery population, the large QTL on bTA7 and QTLs on bTA10 and 12 were *** In summary, QTLs and candidate SNPs identified were associated with pregnancy outcomes in beef heifers, including a large QTL associated with a group of protocadherin genes. Confirmation of these associations

关键词： beef cattle Fertility gWAS QTL

Researching Forms of Shadow Education:Methodological Challenges and Complexities of Private Supplementary Tutoring in Myanmar

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ECNU Review of Education 2024年第1期7卷 89-110页

作者： peter Kamtungtuang Suante Mark bray The University of Hong Kong East China Normal University&The University of Hong Kong

Purpose:The growing literature on private supplementary tutoring,widely known as shadow education,addresses multiple dimensions and ***,many studies inadequately capture the diversity and implications of different forms of *** paper examines these matters in Myanmar,highlighting complexities and ambiguities in descriptors and in the nature of ***/Approach/Methods:Using a mixed-methods design,this study was conducted in Mandalay Region and Chin *** data were obtained from interviews with I10 grade II students,34 high school teachers,30 parents,29 private tutoring providers,and two private school ***:The article categorizes tutoring forms based on their styles and orientations,particularly lecture-type teaching and homework supervision by guides,class sizes,durations of fee-charging(e.g,annually),the number of subjects taught per tutor,and tutoring *** study brings the topic out of the shadows for clearer analysis of the phenomenon and thus for assessment of its ***:The study makes a methodological contribution to the wider picture by demonstrating the need for greater clarity and precision in the national and international comparative *** also underscores shortcomings of predetermined categories in questionnaires and the value of qualitative interviews.

关键词： Classification methodology Myanmar private tutoring shadow education

Interdigitated terahertz metamaterial sensors:design with the dielectric perturbation theory

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Photonics Research 2024年第6期12卷 1115-1128页

作者： LEI CAO FANQI MENg ESRAÖZDEMIR YANNIK LOTH MERLE RICHTER ANNA KATHARINA WIggER MAIRA bEATRIZ PÉREZ SOSA ALAA JAbbAR JUMAAH SHIHAb AL-DAFFAIE peter HARINg bOLÍVAR HARTMUT g.ROSKOS State Key Laboratory of Advanced Electromagnetic Technology Huazhong University of Science and TechnologyWuhan 430074China Physikalisches Institut Johann Wolfgang Goethe-UniversitätFrankfurt am MainGermany University of Siegen Institute for High Frequency and Quantum ElectronicsSiegenGermany Department of Electrical Engineering Eindhoven University of Technology5612 AE EindhovenThe Netherlands

Designing terahertz sensors for highly sensitive detection of nanoscale thin films and a few biomolecules poses a substantial challenge but is crucial for unlocking their full potential in scientific research and advanced *** work presents a strategy for optimizing metamaterial sensors in detecting small quantities of dielectric *** amount of frequency shift depends on intrinsic properties(electric field distribution,Q-factor,and mode volume)of the bare cavity as well as the overlap volume of its high-electric-field zone(s)and the *** by the simplified dielectric perturbation theory,interdigitated electric split-ring resonators(ID-eSRRs)are devised to significantly enhance the detection sensitivity compared with eSRRs without interdigitated ***-eSRR’s fin-gers redistribute the electric field,creating strongly localized enhancements,which boost analyte *** periodic change of the inherent antiphase electric field reduces radiation loss,leading to a higher *** with ID-eSRR sensors operating at around 300 gHz demonstrate a remarkable 33.5 gHz frequency shift upon depositing a 150 nm SiO_(2)layer as an analyte simulant,with a figure of merit improvement of over 50 times compared with structures without interdigitated *** rational design offers a promising avenue for highly sensitive detection of thin films and trace biomolecules.

关键词： dielectric perturbation theory

Nucleation of Supercooled Water by Neutrons: Latitude Dependence and Implications for Cloud Modelling

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Atmospheric and Climate Sciences 2024年第2期14卷 221-232页

作者： peter W. Wilson Elizabeth Wilson-Park Abraham g. Wilson Department of Physics The University at Albany SUNY Albany USA Scripps Institution of Oceanography University of California San Diego USA Philanthropy Australia Sydney Australia The King’ s Institute The King&#8217s School Parramatta Australia

It has recently been shown that incident particles, neutrons, can initiate the freezing in a supercooled water volume. This new finding may have ramifications for the interpretation of both experimental data on the nucleation of laboratory samples of supercooled water and perhaps more importantly on the interpretation of ice nucleation involved in cloud physics. For example, if some fraction of the cloud nucleation previously attributed to dust, soot, or aerosols has been caused by cosmogenic neutrons, fresh consideration is required in the context of climate models. Moreover, as cosmogenic neutrons, most being muon-induced, have much greater flux at high latitudes, estimates of ice nucleates in these regions may be larger than required to accurately model cloud and condensation properties. This discrepancy has been pointed out in IPCC reports. Our paper discusses the connection between the new concept of neutrons nucleating supercooled water and the need for a new source of nucleation in high latitude clouds, ideally causing others to review current data, or to analyse future data with this idea in mind. .

关键词： Climate Models Ice Nucleation Neutrons Supercooling

Investigating the Air Quality Parameters in Louisiana’s Industrial Corridor: A baton Rouge Case Study

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Journal of geoscience and Environment Protection 2024年第7期12卷 139-164页

作者： Oluwafemi Awolesi peter g. Oni Oluwatoyin K. Adekoya Seyi b. Adekoya Oluwafeyikemi D. Ogunmusi Fatemeh ghafari Abosede Oje Odunayo Lawal Department of Environmental Sciences Louisiana State University Baton Rouge USA Department of Construction Management Louisiana State University Baton Rouge USA Department of Chemistry and biochemistry Worcester Polytechnic Institute Worcester USA Department of Water Resource Policy Grand Valley State University Grand Rapids USA Department of Chemistry and Chemical biology The University of New Mexico Albuquerque USA Department of Chemistry University of Louisiana Lafayette USA Research & Development Unit Ecoxygiene Services Limited Lagos Nigeria

In a local context, sustainable development entails utilizing the current resources—material and immaterial, measurable and immeasurable, popular and unpopular—of the community in a manner that avoids overexploitation and ensures intergenerational equity. This approach prioritizes the safety and health of local citizens, placing communal productivity above corporate profitability. This research aims to assess air quality surrounding 28 chemical industry sites in baton Rouge, Louisiana, to understand the environmental and health impacts of industrial pollutants, with a focus on environmental justice. Air quality pollutants, including PM2.5, PM10, O3, NO2, CO, and SO2, were monitored for 75 days during the Summer, using the breezoMeter app. Python, Mapize, and QgIS software technologies were utilized for data analysis and visualization. Findings indicate a reduction in NO2 and CO levels, compared to existing literature. However, the persistent challenge of particulate matter suggests areas for further environmental management efforts. Additionally, the research suggests a significant disparity in air pollution exposure, probably affecting marginalized communities. Although the nature of the study might not fully capture annual pollution trends, the findings highlight the urgent need for the chemical industry to adopt efficient production methods and for policymakers to enhance air quality standards and enforcement, particularly in pollution-sensitive areas. The disproportionate impact of air pollution on vulnerable communities calls for a more inclusive approach to environmental justice, ensuring equitable distribution of clean air benefits and community involvement in pollution management decisions.

关键词： Air Quality Monitoring Chemical Industry Pollution Environmental Justice Health Implications Particulate Matter Case Study