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Breaking the optical efficiency limit of virtual reality with a nonreciprocal polarization rotator

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Opto-Electronic Advances 2024年第3期7卷 4-14页

作者： Yuqiang Ding Zhenyi Luo Garimagai Borjigin Shin-Tson Wu College of Optics and Photonics University of Central FloridaOrlando FL 32816USA Department of Intelligent Interaction Technologies University of TsukubaTsukubaIbaraki 305-8573Japan Research fellow of Japan Society for the Promotion of Science Chiyoda-kuTokyo 102-0083Japan

A catadioptric lens structure,also known as pancake lens,has been widely used in virtual reality(VR)displays to reduce the ***,the utilization of a half mirror(HM)to fold the optical path thrice leads to a significant optical *** theoretical maximum optical efficiency is merely 25%.To transcend this optical efficiency constraint while retaining the foldable characteristic inherent to traditional pancake optics,in this paper,we propose a theoretically lossless folded optical system to replace the HM with a nonreciprocal polarization *** our feasibility demonstration experiment,we used a commercial Faraday rotator(FR)and reflective polarizers to replace the lossy *** theoretically predicted 100%efficiency can be achieved approximately by using two high-extinction-ratio reflective *** addition,we evaluated the ghost images using a micro-OLED panel in our imaging ***,the ghost images can be suppressed to undetectable level if the optics are with antireflection *** novel pancake optical system holds great potential for revolutionizing next-generation VR displays with lightweight,compact formfactor,and low power consumption.

关键词： near-eye display virtual reality pancake optics folded optics nonreciprocal polarization rotator

Low-power SiPM readout BETA ASIC for space applications

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Nuclear Science and Techniques 2024年第3期35卷 153-169页

作者： Anand Sanmukh Sergio Gómez Albert Comerma Joan Mauricio Rafel Manera Andreu Sanuy Daniel Guberman Roger Catala Albert Espinya Marina Orta Oscar de la Torre David Gascon Departament de Física Quàntica i Astrofísica(FQA) Institut de Ciències del Cosmos(ICCUB)Universitat de Barcelona(UB)08028 BarcelonaSpain Institut d’Estudis Espacials de Catalunya(IEEC) 08034 BarcelonaSpain Electronics Department Serra Hunter fellow at Polytechnic University of Catalonia(UPC)08019 BarcelonaSpain

The BETA application-specific integrated circuit(ASIC)is a fully programmable chip designed to amplify,shape and digitize the signal of up to 64 Silicon photomultiplier(SiPM)channels,with a power consumption of approximately~1 mW/*** to its dual-path gain,the BETA chip is capable of resolving single photoelectrons(phes)with a signal-to-noise ratio(SNR)>5 while simultaneously achieving a dynamic range of~4000 ***,BETA can provide a cost-effective solution for the readout of SiPMs in space missions and other applications with a maximum rate below 10 *** this study,we describe the key characteristics of the BETA ASIC and present an evaluation of the performance of its 16-channel version,which is implemented using 130 nm *** ASIC also contains two discriminators that can provide trigger signals with a time jitter down to 400 ps FWHM for 10 *** linearity error of the charge gain measurement was less than 2%for a dynamic range as large as 15 bits.

关键词： Radiation detectors Silicon photomultipliers Photon sensors Front-end electronics Mixed-mode ASICs Space technology

Expanding the liver donor pool worldwide with hepatitis C infected livers, is it the time?

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World Journal of Transplantation 2024年第2期14卷 13-27页

作者： Mai Hashem Mohammed A Medhat Doaa Abdeltawab Nahed A Makhlouf fellow of Tropical Medicine and Gastroenterology Assiut University HospitalAssiut 71515Egypt Department of Tropical Medicine and Gastroenterology Faculty of MedicineAssiut UniversityAssiut 71515Egypt Department of Tropical Medicine and Gastroenterology Al-Rajhi Liver HospitalAssiut UniversityAssiut 71515Egypt

Liver transplantation(LT)provides a life-saving option for cirrhotic patients with complications and hepatocellular *** the increasing number of liver transplants performed each year,the number of LT candidates on the waitlist remains unchanged due to an imbalance between donor organ supply and the demand which increases the waitlist time and *** donor liver transplant had a great role in increasing the donor pool and shortened waitlist time for LT ***,further strategies can be implemented to increase the pool of potential donors in deceased donor LT,such as reducing the rate of organ *** hepatitis C virus(HCV)seropositive liver grafts is one of the expanded donor organ criteria.A yearly increase of hundreds of transplants is anticipated as a result of maximizing the utilization of HCV-positive organs for HCV-negative ***-acting antiviral therapy's efficacy has revolutionized the treatment of HCV infection and the use of HCV-seropositive donors in *** American Society of Transplantation advises against performing transplants from HCV-infected liver donors(D+)into HCV-negative recipient(R-)unless under Institutional Review Board-approved study rules and with full informed consent of the knowledge gaps associated with such *** selection of patients to be transplanted with HCV-infected grafts and confirming their access to direct-acting antivirals if needed is *** and international consensuses are needed to regulate this process to ensure the maximum benefit and the least adverse events.

关键词： Donor pool Hepatitis C-viremic organs Non-viremic organs Direct acting antivirals Hepatitis C virus treated Liver transplantation

Renewable Energies, Present & Future

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电工电能新技术 2005年第1期24卷 69-75页

作者： X. S. Cai fellow ieee E.E. Dept. Tsinghua University Beijing 100084 China

Fossil fuels are major cause of environmental destruction in pollutions. It has created much needed momentum for renewable energies, which are environmentally benign, generated locally, and can play a significant role in developing economy. As a sustainable energy sources, it can grow at a rapid pace to meet increasing demands for electricity in a cost-effective way.

关键词：风力发电太阳能发电能源利用可再生能源

Identifying behavioral determinants and stage of readiness for performing knee massage among individuals with knee osteoarthritis:An observational study

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Journal of Integrative Medicine 2024年第1期22卷 54-63页

作者： Donya Nemati Niki Munk Navin Kaushal College of Nursing the Ohio State UniversityColumbusOH 43210USA Department of Health Sciences School of Health&Human SciencesIndiana UniversityIndianapolisIN 46202USA National Centre for Naturopathic Medicine Southern Cross UniversityLismoreNew South Wales 2480Australia Australian Research Centre in Complementary and Integrative Medicine(ARCCIM) Massage&Myotherapy Australia Fellow and Visiting Faculty of HealthUniversity of Technology SydneyNew South Wales 2007Australia

Objective Patients who experience knee osteoarthritis or chronic knee pain can alleviate their symptoms by performing self-knee *** the readiness and types of determinants needed to facilitate self-knee massage is needed to design effective,theory-informed *** primary objective of this study was to apply the transtheoretical model of behavior change to identify how factors,which include the type of knee condition and pain level,predict an individual’s readiness to adopt self-knee *** secondary objective employed the capability,opportunity and motivation-behavior(COM-B)model to identify relevant determinants that are predictive of an individual’s readiness to undertake self-knee *** An observational study design was used to recruit individuals with knee osteoarthritis(n=270)and chronic knee pain(n=130).Participants completed an online survey that assessed the transtheoretical model of behavior change stages,COM-B determinants(capability,opportunity and motivation),along with self-administered massage *** analysis of covariance and structural equation modeling were used to test the primary and secondary objective,*** Participants who had knee osteoarthritis scored higher on the action stage compared to those with chronic pain(P=0.003),and those who experienced greater level of pain scored higher in the contemplation(P<0.001)and action phases(P<0.001)of performing knee massage compared to those with milder *** COM-B structural equation model revealed self-administered knee massage to be predicted by capability(β=0.31,P=0.004)and motivation(β=0.29,P<0.001),but not opportunity(β=–0.10,P=0.39).Pain level predicted motivation(β=0.27,P<0.001),but not capability(β=0.09,P=0.07)or opportunity(β=0.01,P=0.83).Tests for mediating effects found that determinants of COM-B(motivation and capability)mediate between pain level and self-administered massage behavior(β=0.10,P=0.002).Conclusion Cl

关键词： Osteoarthritis Massage Self-management Transtheoretical model of behavior change Behavioral model

Dynamic Power and Sub-carrier Allocation for OFDMA-based Wireless Multicast Systems

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Dynamic Power and Sub-carrier Allocation for OFDMA-based Wir...

Elevation transition of aquatic insects closely matches a thermal feature in the Yungas of Northwestern Argentina

2008 ieee International Conference on Communications(ICC 2008)

作者： K.B.Letaief fellow IEEE

Dynamic resource allocation is a key technique that can significantly improve the performance of next generation wireless systems under guaranteed QoS to *** of the current resource allocation algorithms are,however,limited to unicast *** practice,how to efficiently allocate various resources in multicast wireless systems is not *** this paper,we shall study dynamic resource allocation for OFDMAbased single-cell multicast ***,we shall formulate an optimization problem to maximize the system throughput given a set of available resources （power and sub-carriers）.The optimal resource allocation solution is proposed along with a lowcomplexity *** two extreme cases,namely,low and high SNR regimes,the low-complexity allocation algorithm is further *** results will show that the system throughput is significantly improved by using our proposed algorithms.

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Journal of Mountain Science 2024年第2期21卷 433-448页

作者： Alexandra BUITRAGO-GUACANAME Carlos MOLINERI Andrés LIRA-NORIEGA Daniel Andrés DOS SANTOS Neotropical Biodiversity Institute(CONICET-UNT) UNT-DomesHorco Molle S/N4107 TucumánArgentina CONACYT Research fellow Network of Advanced Molecular StudiesInstitute of Ecology A.COld Road to Coatepec 351El HayaCP 91073XalapaVeracruzMexico Biostatistics Chair Faculty of Natural Sciences and IMLNational University of TucumánSan Miguel de TucumánMiguel Lillo 2054000 TucumánArgentina

Temperature is a key factor that shapes the distribution of *** knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate *** insects are particularly vulnerable to climate change,yet there is still much to learn about their ecology and *** the Yungas ecoregion of Northwestern Argentina,cold-and warm-adapted species of the orders Ephemeroptera,Plecoptera,and Trichoptera(EPT)are segregated by *** modeled the ecological niche of South American EPT species in this region using available data and projected their potential distribution in geographic *** were grouped based on their ecogeographic similarity,and we analyzed their replacement pattern along elevation gradients,focusing on the ecotone where opposing thermal preferences *** this interface,we identified critical points where the combined incidence of cold and warm assemblages maximizes,indicating a significant transition *** found that the Montane Cloud Forest holds the interface,with a particularly greater suitability at its lower *** main axis of the interface runs in a N-S direction and falls between 14°C-16°C mean annual *** probability of a particular location within a basin being classified as part of the interface increases as Kira’s warmth index approaches a score around *** the interface is critical for defining the thermal limits of species distribution and designing biomonitoring *** in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation *** have recognized significant temperature thresholds that serve as indicators of suitability for the *** global warming is anticipated to shift these indicators,we suggest using them to monitor the imprints of climate change on mountain ecosystems.

关键词： Austral Yungas Ecological Niche Model Ephemeroptera Kira’s warmth index Plecoptera Trichoptera

Power Conversion System Strategies for Fuel Cell Vehicles

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电工电能新技术 2005年第1期24卷 8-13,44页

作者： Kaushik Rajashekara fellow ieee Delphi Corporation Mail Code ERC 12/ D35 P.O. Box 9005 Kokomo IN 46904-9005 USA

Power electronics is an enabling technology for the development of environmental friendly fuel cell vehicles, and to implement the various vehicle electrical architectures to obtain the best performance. In this paper, power conversion strategies for propulsion and auxiliary power unit applications are described. The power electronics strategies for the successful development of the fuel cell vehicles are presented. The fuel cell systems for propulsion and for auxiliary power unit applications are also discussed.

关键词：电动汽车 PEM APU 燃料电池

Rivaroxaban’s vascular dose for the neurovascular clinician

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中华神经外科杂志(英文) 2024年第3期10卷 1-3页

作者： Chong Ji Y. Jan Kalimullah Stroke Center New York Medical College Westchester Medical Center Valhalla NY USA Neurovascular fellow New York Medical College Westchester Medical Center Valhalla NY USA

Rivaroxaban, a direct oral anticoagulant, has proven efficacy and safety at its standard dose in the treatment and prevention of various vascular conditions. These include the treatment of venous thromboembolism and stroke prevention in non-valvular atrial fibrillation. A "very low" vascular dose of rivaroxaban, when combined with low-dose aspirin, has been demonstrated to reduce major adverse cardiovascular events, including stroke, in both acute and chronic coronary syndrome. The combination of rivaroxaban and low-dose aspirin could potentially offer an additional strategy for stroke prevention in selected non-atrial fibrillation patients who are at a high risk of stroke.

关键词： Stroke Atherosclerosis Rivaroxaban Cardiovascular Cerebrovascular