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Why Sustainable Porous Carbon Should be further Explored as Radar-Absorbing Material? A Comparative Study with Different nanostructured Carbons

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Journal of Renewable Materials 2024年第10期12卷 1639-1659页

作者： alan f.n.boss Manuella G.C.Munhoz Gisele Amaral-Labat Rodrigo G.A.Lima Leonardo I.Medeiros nila C.f.L.Medeiros Beatriz C.S.fonseca flavia L.Braghiroli Guilherme f.B.Lenz e Silva Department of Metallurgical and Materials Engineering University of de São PauloAvenida Mello MoraesCidade UniversitáriaSão PauloSP 05508-030Brazil Coordination of Applied Research and Technological Development National Institute for Space ResearchAvenida dos AstronautasJardim da GranjaSão Josédos CamposSP 12227-010Brazil Department of Exact and Technological Sciences Santa Cruz State UniversityRodovia Jorge Amadokm16IlhéusBA 45662900Brazil Institut de recherche sur les forêts Universitédu Québec en Abitibi-TémiscamingueRouyn-Noranda445 Bd de l’UniversitéRouyn-NorandaQC J9X 5E4Canada

Radar Absorbing Materials(RAM)are a class of composites that can attenuate incident electromagnetic waves to avoid radar *** carbon allotropes that have the potential to be used as RAM are either carbon nano-tubes(CnTs),graphene,carbon black(CB)and ultimately,sustainable porous carbon(SPC).Here,black wattle bark waste(following tannin extraction)was used as a sustainable source to produce SPC made from biomass *** was characterized and used as afiller for a silicone rubber matrix to produce aflexible *** elec-tromagnetic performance of this composite was compared with composites made with commercial CB and CnT through reflection loss(RL),where-10 dB is equivalent to 90%of *** composites were evaluated in single-layer,double-layer,and as radar absorbing structures(RAS)with the aim of improving their effective absorption bandwidth(EAB)performances and a reduction in *** CnT composite presented a RL of-26.85 dB at 10.89 GHz and an EAB of 2.6 GHz with a 1.9 mm thickness,while the double-layer structures using CnT and SPC provided a RL of-19.74 dB at 10.75 GHz and an EAB of 2.51 ***,the double-layer structures are~42%cheaper than the composite using only CnT since less material is ***,the largest EAB was achieved with a RAS using SPC,reaching~2.8 GHz and a RL of-49.09 dB at 10.4 ***,SPC made of black wattle bark waste can be a competitive,alternative material for use as RAM and RAS since it is cheaper,sustainable,and suitable for daily life uses such as absorbers for anechoic chambers,sensors,and elec-tromagnetic interference shields for electronics,wallets,vehicles,and others.

关键词： Microwave absorption material tannin waste dielectric constant carbon composite reflectivity

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Altered Allogeneic Immune Responses in Middle-Aged Mice

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Cellular & Molecular Immunology 2004年第6期1卷 440-446页

作者： alan n.Langnas Department of Surgery University of Nebraska Medical CenterThe Lied Transplant CenterUNMCOmahaNEUSA.

It is well known that leukocyte composition,T cell phenotypes and immune function change in aged mice and ***,limited and conflicting results on the age-related immune changes in middle-aged mice were *** of the characteristics of allogeneic immune responses in aging mice may offer important information for transplantation *** major age-related changes in the immune cell phenotypes and function of 12 months old mice include:1)the significantly decreased CD4^+ cell population in the peripheral blood,the major peripheral CD4^+ cells is CD45RB^(low)CD62L^(low)memory phenotype;2)the in vitro responses to alloantigens and Con A of splenocytes markedly reduced;3)the in vivo secondary humoral immune responses to alloantigens significantly declined;4)the age-related alteration in the thymus mainly occurred in CD4/CD8 double positive(DP)stage;and 5)increased CD80^+ and MHC class II^+ cell population in ***,the major age-related immune changes in 12 months old mice occurred in CD4^+ T cells in the periphery and DP stage in the thymus,which may subsequently lead to the decreased allogeneic immune responses and the different sensitivity to immunosuppressive drugs and *** studies on the characteristics of allogeneic immunity in aging individuals may help to determine the appropriated treatment for transplant aging *** & Molecular Immunology.2004;1(6):440-446.

关键词： allogene middle-aged transplantation

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An update on the management of non-variceal upper gastrointestinal bleeding

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Gastroenterology Report 2023年第1期11卷 60-77页

作者： Ali A.Alali alan n.Barkun Division of Gastroenterology Department of medicineFaculty of MedicineKuwait UniversityKuwait Division of Gastroenterology McGill University Health CenterMcGill UniversityMontrealCanada

Upper gastrointestinal bleeding(UGIB)continues to be a common gastrointestinal emergency that carries significant morbidity and *** epidemiology of UGIB has been changing over the last few decades with an overall decrease in peptic ulcer disease and increase in the prevalence of other etiologies including vascular lesions and *** risk assessment and patient stratification are crucial to ensuring that optimal care is delivered to patients and some risk assessment tools have shown excellent ability to define a low-risk group who can be managed as outpatients *** of the etiology of UGIB,resuscitative interventions by primary care providers remain the most important initial measures to improve the outcome for patients including hemodynamic stabilization,an appropriate blood transfusion strategy,with or without acid-lowering agents,while also providing subsequent urgent endoscopic assessment and *** addition,with increasing use of antithrombotic agents in clinical practice and its associated risk of bleeding,the management of such agents in the acute setting has become a real challenge to all *** this article,we provide an up-to-date,evidence-based,practical review of recent changes and advances in UGIB with a focus on non-variceal etiologies.

关键词： UGIB peptic ulcer endoscopic hemostasis risk assessment antithrombotic

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Hazards from lakes and reservoirs: new interpretation of the Vaiont disaster

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Journal of Mountain Science 2022年第6期19卷 1717-1737页

作者： alan P.DYKES Edward n.BROMHEAD Centre for Engineering Environment and Society ResearchSchool of Engineering and the EnvironmentKingston UniversityPenrhyn RoadKingston upon ThamesKTi 2EEUK

Hazards in reservoirs and lakes arising from subaerial landslides causing impact waves(or ‘lake tsunamis’) are now well known, with several recent examples having been investigated in detail. The potential scale of such hazards was not widely known at the time of the Vaiont dam project in the 1950s and early 1960s, although a small wave triggered by a landslide at another new reservoir nearby in the Dolomites(northern Italy) drew the possible hazard to the attention of the Vaiont project’s managers. The Vaiont disaster in 1963 arose from a combination of disparate and seemingly unrelated factors and circumstances that led to an occurrence that could not have been imagined at that time. The ultimate cause was a very large landslide moving very rapidly into a reservoir and displacing the water. The resulting wave overtopped the dam to a height of around 175 m and around 2000 people were killed. This paper identifies and examines all of the issues surrounding the Vaiont dam and landslide in order to identify causal factors, contributory factors(including aggravating factors) and underlying factors. In doing so, it demonstrates that the disaster arose from the Vaiont dam project and cannot be attributed simply to the landslide. Underlying geological factors gave rise to the high speed of the landslide, which would have occurred anyway at some time. However, without the contributory factors that account for the presence of the reservoir, i.e. the choice of location for the project and management of the project with respect to a possible landslide hazard, there would have been no disaster. Indeed, the disaster could have been avoided if the reservoir could have been emptied pending further ground investigations. Understanding of this case provides many lessons for future dam projects in mountainous locations but also highlights an ongoing and perhaps under-appreciated risk from similar events involving other water bodies including geologically recent lakes formed behind n

关键词： Vaiont landslide Impulse wave Lake tsunami Dam project Causal factors for disaster

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Taxonomic confusion of two tramp ant species： Iridomyrmex anceps and Ochetellus glaber are really species complexes

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Current Zoology 2011年第5期57卷 662-667页

作者： Benjamin D. HOffMAnn alan n. AnDERSEn Xiang ZHAnG CSIRO Ecosystem Sciences Tropical Ecosystems Research Centre PMB 44 Winnellie NT 0822 Australia College of Plant Protection Fujian Agriculture and Forestry University Fuzhou Fujian 350002 China

Many invasive invertebrates belong to unresolved species complexes, and have a history of misidentification and in-appropriate management. Here we detail confusion surrounding the taxonomy and identification of two dolichoderine ant species, Iridomyrmex anceps Roger and OcheteUus glaber Mayr, which are commonly cited in the literature as having been spread widely by human commerce. We provide morphometric data and images strongly suggesting that these two ＂species＂ are instead com- plexes of species that are likely native to many regions where they are purportedly introduced. We take particular interest in the status of species referred to as L anceps and O. glaber in China, as this is the most northerly distribution of both genera. We con-clude by suggesting that many identifications of both species are likely to be unreliable, and we recommend against any manage- ment action aimed at controlling these species under the assumption that they are exotic [Current Zoology 57 （5）： 662-667, 2011].

关键词： Ant Exotic Invasive Invertebrate Management Tramp ant

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Medical research during the COVID-19 pandemic

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World Journal of Clinical Cases 2020年第15期8卷 3156-3163页

作者： Khalid Alnaamani Siham AlSinani alan n Barkun Division of Gastroenterology Department of Internal MedicineArmed Forces HospitalMuscat 999046Oman Graduate Medical Education Department and Department of Child Health Sultan Qaboos University HospitalMuscat 999046Oman Division of Gastroenterology McGill University and the McGill University Health CentreMontreal H3G1A4Canada

The current pandemic of coronavirus disease 2019(COVID-19)which was first detected in Wuhan,China in December 2019 is caused by the novel coronavirus named severe acute respiratory syndrome coronavirus-2(SARS-CoV-2).The virus has quickly spread to a large number of countries leading to a great number of ***,till today there is no specific treatment or vaccination for *** of the suggested treatment medications are based on in vitro laboratory investigations,experimental animal models,or previous clinical experience in treating similar viruses such as SARS-CoV-1 or other retroviral *** running of any clinical trial during a pandemic is affected at multiple *** for this include patient hesitancy or inability to continue investigative treatments due to self-isolation/quarantine,or limited access to public places(including hospitals).Additional barriers relate to health care professionals being committed to other critical tasks or quarantining themselves due to contact with COVID-19 positive *** best research approaches are those that adapt to such external unplanned *** clinical trials before COVID-19 pandemic have the potential for identifying important therapies in the long-term if they can be completed as ***,these clinical trials may require modifications due a pandemic such as this one to ensure the rights,safety,and wellbeing of participants as well as medical staff involved in the conduction of clinical *** trials initiated during the pandemic must be time-efficient and flexible due to high contagiousness of severe acute respiratory syndrome coronavirus 2,the significant number of reported deaths,and time constraints needed to perform high quality clinical trials,enrolling adequate sample *** between different countries as well as implementation of innovative clinical trial designs are essential to successfully complete such initiatives during the cur

关键词： SARS-CoV-2 COVID-19 Pandemic Research Clinical trials

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Diversity and biogeography of a species-rich ant fauna of the Australian seasonal tropics

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Insect Science 2018年第3期25卷 519-526页

作者： alan n. Andersen Benjamin D. Hoffmann Stefanie Oberprieler CSIRO Land & Water Tropical Ecosystems Research Centre Darwin Austrafia Research Institute forthe Environment and Livelihoods Charles Darwin University Darwin Australia Research School of Biology Australian National University Canberra Australia

Although ants are an ecologically dominant and extensively studied faunal group throughout the tropics, there is a poor understanding of tropical ant diversity and distribution at large spatial scales. Here we use a collection developed from 3 decades of ant surveys to present the first analysis of ant diversity and biogeography of a large tropical region. Our objective was to document the species richness, composition, and biogeographic distributions of the ant fauna of the 400 000 km^2 ＂Top End＂ of Australia＇s northern Territory. The known Top End ant fauna comprises 901 native species from 59 genera. The richest genera are Pheidole （90 species）, Melophorus （83）, Monomorium （83）, Camponotus （71）, Meranoplus （63）, Polyrhachis （57）, Rhytidoponera （50）, Tetramorium （43）, Cerapachys （32）, and Iridomyrmex （31）. The fauna is the center of diverse radiations within species-groups of genera such as Meranoplus, Rhytidoponera, and Leptogenys. It also includes IndoMalayan species that have likely bypassed the normal dispersal route into Australia through Cape York Peninsula in north Queensland. faunistic similarity with other regions of far northern Australia is associated more with rainfall than with geographic proximity. Most （60%） of Top End ant species have not been recorded elsewhere, and, despite uncertainties relating to species delimitation and sampling intensity, this appears to be a credible estimate of the level of endemism. Such exceptionally high endemism can be attributed to the Top End＇s geographic isolation from other regions of northern Australia with comparably high rainfall.

关键词： endemism northern Australia northern Territory species distribution tropical savanna

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D614G and SARS-CoV-2 replication fitness

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Signal Transduction and Targeted Therapy 2021年第4期6卷 1073-1074页

作者： Kathleen D.Engelman alan n.Engelman MassBiologics University of Massachusetts Medical SchoolBostonMAUSA Department of Cancer Immunology and Virology Dana-Farber Cancer InstituteBostonMAUSA Department of Medicine Harvard Medical SchoolBostonMAUSA

Molecular determinants of SARS-CoV-2 replication fitness and sensitivity to neutralization via the humoral immune response critically inform efforts to combat the COVID-19 *** published recently by Plante et *** natur... 详细信息

关键词： al. processes. D61

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Sexual selection affects the sizes of the mammalian prostate gland and seminal vesicles

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Current Zoology 2009年第1期55卷 1-8页

作者： Matthew J. AnDERSOn alan f. DIXSOn Conservation and Research for Endangered Species Zoological Society of San Diego School of Biological Sciences Victoria University of Wellington

The accessory reproductive glands of male mammals contribute the bulk of the secretions in which spermatozoa are transported to the female tract during copulation. Despite their morphological diversity, and the chemical complexity of their products, little is known about the possible effects of sexual selection upon these glands in mammals. Here we consider the seminal vesicles and prostate glands in a sample of 89 species and 60 genera representing 8 Orders of mammals. The sizes of the accessory glands are analysed in relation to body weight and testes weight. Both the seminal vesicles size and prostate size （corrected for body weight） correlate positively with relative testes size in this sample; this finding remains highly significant after application of procedures to correct for possible phylogenetic biases in the data set. The accessory reproductive glands are also significantly larger in those mammals which have large relative testes sizes, and in which the likelihood of sperm competition is greatest. These results support the hypothesis that sexual selection has played an important role in the evolution of the mammalian prostate gland and seminal vesicles.

关键词： Mammals Prostrate gland Seminal vesicles Sexual selection Sperm competition

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A study of fire propagation in coal seam with numerical simulation of heat transfer and chemical reaction rate in mining field

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International Journal of Mining Science and Technology 2019年第6期29卷 873-879页

作者： Moisés Oswaldo Bustamante Rúa alan José Daza Aragón Pablo Bustamante Baena national University of Colombia Cr 65 # 63 20 CIMEX Minerals Institute

Spontaneous combustion of coal is a problem that affects the mining operation and generates environ-mental,economic,social and geotechnical *** phenomenon has been divided into two pro-cesses:ignition and *** propagation develops in coal seams because of a set of factors such as direction and wind speed,fracturing and *** this work,heat transfer and chemical kinetics are studied from conservation equations of energy and species,respectively,using the software COMSOL Multiphysics to simulate the propagation of fires in coal *** possible scenarios were analyzed that usually occur in the walls of the coal seams,such as fire focus and fire complete *** was found that the propagation kinetics of the fire changes depending on the temperature,the fractur-ing of rock mass and the area of fire *** temperature values lower than 300℃,there is con-sumption around 250 cm^3/h,values around 700℃,the consumption is 1500 cm^3/h,and for fires of 1200℃ have values of 3000 cm^3/*** on the speed of propagation can vary from 4 to 17cm/day,considering on the level and fracturing of the final wall of the open pit.

关键词： Spontaneous combustion of coal Open pit mines Simulation Heat transfer Chemical reaction COMSOL

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