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Damage evolution of rock-encased-backfill structure under stepwise cyclic triaxial loading

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 597-615页

作者： Xin Yu Yuye Tan Weidong song john Kemeny shengwen Qi Bowen Zheng songfeng Guo Key Laboratory of shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100089China Innovation Academy for Earth science Chinese Academy of SciencesBeijing100089China University of Chinese Academy of sciences Beijing100049China school of Civil and Resources Engineering University of Science and Technology BeijingBeijing100083China Key Laboratory of High-Efficient Mining and safety of Metal Mines(Ministry of Education of China) University of Science and Technology BeijingBeijing100083China Department of Mining and Geological Engineering University of ArizonaTucsonAZ86721USA

Rock-encased-backfill(RB)structures are common in underground mining,for example in the cut-andfill and stoping *** understand the effects of cyclic excavation and blasting activities on the damage of these RB structures,a series of triaxial stepwise-increasing-amplitude cyclic loading experiments was conducted with cylindrical RB specimens(rock on outside,backfill on inside)with different volume fractions of rock(VF=0.48,0.61,0.73,and 0.84),confining pressures(0,6,9,and 12 MPa),and cyclic loading rates(200,300,400,and 500 N/s).The damage evolution and meso-crack formation during the cyclic tests were analyzed with results from stress-strain hysteresis loops,acoustic emission events,and post-failure X-ray 3D fracture *** results showed significant differences between cyclic and monotonic loadings of RB specimens,particularly with regard to the generation of shear microcracks,the development of stress memory and strain hardening,and the contact forces and associated friction that develops along the rock-backfill *** important finding is that as a function of the number of cycles,the elastic strain increases linearly and the dissipated energy increases ***,compared with monotonic loading,the cyclic strain hardening characteristics are more sensitive to rising confining pressures during the initial compaction *** finding is that compared with monotonic loading,more shear microcracks are generated during every reloading stage,but these microcracks tend to be dispersed and lessen the likelihood of large shear fracture *** transition from elastic to plastic behavior varies depending on the parameters of each test(confinement,volume fraction,and cyclic rate),and an interesting finding was that the transformation to plastic behavior is significantly lower under the conditions of 0.73 rock volume fraction,400 N/s cyclic loading rate,and 9 MPa *** the findings have important practical implications on t

关键词： Rock and backfill Triaxial cyclic loading Volume fraction Damage evolution 3D visualization

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What diameter?What height?Influence of measures of average tree size on area-based allometric volume relationships

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Forest Ecosystems 2024年第1期11卷 100-109页

作者： Yilin Wang john A.Kershaw Mark J.Ducey Yuan sun James B.McCarter Integrated Forest Mensuration and systems Analysis Laboratory Faculty of Forestry and Environmental ManagementUniversity of New BrunswickFrederictonNBCanada Department of Natural Resources and the Environment University of New HampshireDurhamNHUSA College of Forestry Nanjing Forestry UniversityNanjing210037China scientific Programmer RayonierYuleeFLUSA

Volume is an important attribute used in many forest management *** from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume *** density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height *** density was not included(Volume=f(Diameter,Height)),the opposite was *** models with density included,moment-based estimators of stand diameter and height performed better than all other *** models without density,largest tree estimators of stand diameter and height performed better than other *** overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses.

关键词： Allometric relationships stand structure Volume estimation stand-level attributes

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Combination treatment of inflammatory bowel disease:Present status and future perspectives

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World Journal of Gastroenterology 2024年第15期30卷 2068-2080页

作者： john K Triantafillidis Constantinos G Zografos Manousos M Konstadoulakis Apostolos E Papalois Inflammatory Bowel Disease Unit "Metropolitan General"HospitalHolargos 15562AtticaGreece Hellenic society for Gastrointestinal Oncology 354 Iera OdosChaidari 12461AtticaGreece The 2^(nd)Department of surgery University of AthensSchool of MedicineAretaieion HospitalAthens 11528Greece Unit of surgical Research and Training The 2^(nd)Department of SurgeryUniversity of AthensSchool of MedicineAretaieion HospitalAthens 11528Greece

The treatment of patients with inflammatory bowel disease(IBD),especially those with severe or refractory disease,represents an important challenge for the clinical *** seems to be no exaggeration to say that in these patients,not only the scientific background of the gastroenterologist is tested,but also the abundance of“gifts”that he should possess(insight,intuition,determ-ination,ability to take initiative,etc.)for the successful outcome of the *** daily clinical practice,depending on the severity of the attack,IBD is treated with one or a combination of two or more pharmaceutical *** combin-ations include not only the first-line drugs(e.g.,mesalazine,corticosteroids,antibiotics,etc)but also second-and third-line drugs(immunosuppressants and biologic agents).It is a fact that despite the significant therapeutic advances there is still a significant percentage of patients who do not satisfactorily respond to the treatment ***,a part of these patients are going to *** recent years,several small-size clinical studies,reviews,and case reports have been published combining not only biological agents with other drugs(e.g.,immunosuppressants or corticosteroids)but also the combination of two biologi-cal agents simultaneously,especially in severe *** our opinion,it is at least a strange(and largely unexplained)fact that we often use combinations of drugs in a given patient although studies comparing the simultaneous administration of two or more drugs with monotherapy are very *** mentioned above,there is a timid tendency in the literature to combine two biological agents in severe cases unresponsive to the applied treatment or patients with severe extraintestinal *** appropriate dosage,the duration of the administration,the suitable timing for checking the clinical and laboratory outcome,as well as the treatment side-effects,should be the subject of intense clinical research *** this

关键词： Biologics for immune-mediated conditions Dual-targeted treatment Combination treatment Inflammatory bowel disease Crohn’s

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Development and characterization of 3D-printed electroconductive pHEMA-co-MAA NP-laden hydrogels for tissue engineering

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Bio-Design and Manufacturing 2024年第3期7卷 262-276页

作者： sara De Nitto Aleksandra serafin Alexandra Karadimou Achim schmalenberger john J.EMulvihill Maurice N.Collins DIBRIs Polytechnic Inter-school section University of Genoa16126 GenoaItaly school of Engineering Bernal InstituteUniversity of LimerickLimerick V94 T9PXIreland school of Natural sciences Department of Biological SciencesUniversity of LimerickLimerick V94 T9PXIreland Health Research Institute University of LimerickLimerick V94 T9PXIreland AMBER University of LimerickLimerick V94 T9PXIreland

Tissue engineering(TE)continues to be widely explored as a potential solution to meet critical clinical needs for diseased tissue replacement and tissue *** this study,we developed a poly(2-hydroxyethyl methacrylate-co-methacrylic acid)(pHEMA-co-MAA)based hydrogel loaded with newly synthesized conductive poly(3,4-ethylene-dioxythiophene)(PEDOT)and polypyrrole(PPy)nanoparticles(NPs),and subsequently processed these hydrogels into tissue engineered constructs via three-dimensional(3D)*** presence of the NPs was critical as they altered the rheological properties during ***,all samples exhibited suitable shear thinning properties,allowing for the development of an optimized processing window for 3D *** were 3D printed into pre-determined disk-shaped configurations of 2 and 10 mm in height and diameter,*** observed that the NPs disrupted the gel crosslinking efficiencies,leading to shorter degradation times and compressive mechanical properties ranging between 450 and 550 *** conductivity of the printed hydrogels increased along with the NP concentration to(5.10±0.37)×10^(−7)s/*** vitro studies with cortical astrocyte cell cultures demonstrated that exposure to the pHEMA-co-MAA NP hydrogels yielded high cellular viability and proliferation ***,hydrogel antimicrobial studies with staphylococcus epidermidis bacteria revealed that the developed hydrogels affected bacterial *** together,these materials show promise for various TE strategies.

关键词： Conductive nanoparticles Hydroxyethyl methacrylate(HEMA) Ultraviolet(UV)polymerization 3D printing

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Morphometric study of the Mastoid Process and its Role in sex Differentiation:A Nigerian Computed Tomography study

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Journal of Forensic science and Medicine 2024年第1期10卷 1-10页

作者： Beryl shitandi Ominde john NIgabari Joyce Ekeme Ikubor Department of Human Anatomy and Cell Biology Delta State UniversityAbrakaNigeria Department of Mathematics Delta State UniversityAbrakaNigeria Department of Radiology Delta State University Teaching HospitalOgharaNigeria

Background:The mastoid process can be utilized in forensic identification due to its resistance to alterations and population variations in its *** study investigated the role of mastoid parameters in the determination of sex in a Nigerian *** and Objectives:The aim of this study was to determine the gender differences in measurements of the mastoid ***,the study aimed at assessing the percentage accuracy of using the mastoid variables in sex *** and Methods:This cross-sectional study used computed tomographic images of the brain,stored in the radiology unit of a referral hospital in Delta state,*** was granted by the hospital’s Ethics *** measurements of the mastoid process were taken on images of 310 patients(170 males and 140 females)aged 20-80 *** were summarized using means and standard ***,side,and age group comparisons were assessed using the independent t-test,paired t-test,and analysis of variance,*** association between variables was probed using Pearson’s correlation *** discriminant function analysis was used to determine the accuracy of correct sex *** probability value was set atsurements were larger in males than in females(Psagittal diameter,and mediolateral inclination angle showed significant differences between age groups(Pshowed a significant positive correlation with age(0stoid distance was the best sex-discriminating variable(89.4%).Using all nine variables,the accuracy of sex prediction was 89.7%.Conclusion:The sexually dimorphic mastoid dimensions can collectively be used for sex determination with acceptable accuracies,in cases where only the fragmented parts of the temporal bone are available in Delta state,Nigeria.

关键词： Forensic mastoid process measurements sex determination

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HVOF-sprayed HAp/s53P4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants

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Journal of Magnesium and Alloys 2024年第1期12卷 345-360页

作者： Carlos A.Poblano-salas john Henao Astrid L.Giraldo-Betancur Paola Forero-sossa Diego German Espinosa-Arbelaez Jorge A.González-sánchez Luis R.Dzib-Pérez susana T.Estrada-Moo Idelfonso E.Pech-Pech CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-Cinvestav Libramiento Norponiente#2000.Fraccionamiento Real de JuriquillaQuerétaro 76230Mexico Universidad Tecnológica de Querétaro Av.Pie de la Cuesta N°2501Querétaro 76148Mexico CIDEsI Av.Playa Pie de la Cuesta No 702Col.San PabloQuerétaro 76125Mexico Center for Corrosion Research Autonomous University of CampecheAv.Héroe de Nacozari No.480P.C.24070San Francisco de CampecheCam.Mexico

Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro *** the present work,75%***-25%wt.s53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/s53P4 BG composite coatings on a bioresorbable AZ31 *** study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those *** characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite *** results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal *** was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the *** addition,in-vitro electrochemical studies were performed on the obtained HAp/s53P4 BG composite coatings and compared against the uncoated AZ31 *** results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(sBF).

关键词： Coatings Composites Thermal spray Temporary implants Hydrogen evolution

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Extractable and kerogen-bound hopanoids from typical Eocene oil shales in China

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Energy Geoscience 2024年第2期5卷 171-179页

作者： Changbo Zhai Zhirong Zhang john K.Volkman Hong Lu Yan'e Chen sINOPEC Key Laboratory of Petroleum Accumulation Mechanisms Wuxi Institute of Petroleum GeologySINOPEC2060 Lihu RoadWuxiJiangsu213126China sINOPEC Petroleum Exploration and Production Research Institute 31 Xueyuan RoadBeijing100083China state Key Laboratory of Organic Geochemistry Guangzhou Institute of GeochemistryChinese Academy of ScienceGuangzhou510640GuangdongChina

This study conducted a comparative analysis of extractable hopanoid hydrocarbons and those released via stepwise pyrolysis of typical Eocene immature oil shales in China,namely the Huadian,Maoming,and Fushun *** the Huadian and Maoming shales exhibit immature indicators in extractable and kerogen-bound hopanoids(notably,high abundance of C_(29)to C_(32)17β,21β-hopanes and unsaturated hopenes).In contrast,the Fushun oil shale's hopanoids from extracts and pyrolyzates suggest a higher maturity *** absence of neohopenes in the pyrolyzates of the shales underpins that the kerogenbound hopanoid skeletons resist ***,the Huadian oil shale's asymmetric distribution of C_(29)and C_(30)hopenes and neohopenes hints at the presence of an additional *** unsaturated hopenes,such as hop-20(21)-enes,identified in pyrolyzates of the three kerogens at various pyrolysis temperatures,reveal the occurrence of double bonds in kerogen-bound hopanoid skeletons without methyl *** absence of hop-20-(21)-ene in extracts suggests that it might act as an intermediate of these novel hopenes during the epimerization of hopanoid skeletons within *** extractable and pyrolytic hopanoids'stereochemical alignment indicates that epimerization may occur in both ring systems and alkyl side chains of kerogen-bound hopanoid *** stepwise pyrolysis proves to be a quick screening method for geological hopanoids without causing any significant alteration to the original skeletons even when cracking multiple covalent bonds is necessary.

关键词： Hopanoid Hopane Hopene Neohopene stepwise pyrolysis Kerogen Eocene oil shale

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Orchard sports Injury and Illness Classification system (OsIICs) Version 15

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Journal of sport and Health science 2024年第4期13卷 599-604页

作者： john W.Orchard Ebonie Rio Kay M.Crossley Jessica J.Orchard Margo Mountjoy school of Public Health University of SydneySydneyNSW 2006Australia La Trobe sport and Exercise Medicine Research Centre La Trobe UniversityMelbourneVIC 3083Australia Department of Family Medicine McMaster UniversityHamilton L8S 4L8Canada

Background:sports medicine(injury and illnesses)requires distinct coding systems because the International Classification of Diseases is insuf-ficient for sports medicine *** Orchard sports Injury and Illness Classification system(OsIICs)is one of two sports medicine coding systems recommended by the International Olympic *** updates of coding systems are ***:For Version 15,updates for mental health conditions in athletes,sports cardiology,concussion sub-types,infectious diseases,and skin and eye conditions were considered particularly ***:Recommended codes were added from a recent International Olympic Committee consensus statement on mental health conditions in *** landmark sports cardiology papers were used to update a more comprehensive list of sports cardiology *** union protocols on head injury assessment were used to create additional concussion ***:It is planned that OsIICs Version 15 will be translated into multiple new languages in a timely fashion to facilitate international *** large number of recently published sport-specific and discipline-specific consensus statements on athlete surveillance warrant regular updating of OsIICs.

关键词： sports cardiology Dermatology Eye injuries Concussion Infectious diseases sports injury classification

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A four-band index for both liquid and solid water and its applications in the Aral sea Basin

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science China Earth sciences 2024年第3期67卷 769-788页

作者： Bing YUE Xi CHEN saibo LI Zhengping DU john WILsON Junhui YANG Yimen JIAO shuangyan HUANG Chenghu ZHOU Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Institute of Geographical sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China spatial sciences Institute University of Southern CaliforniaLos AngelesCA 90089-0374USA

Various investigations have been conducted to analyze the water-coverage area of the Aral sea and the Aral sea Basin(AsB). However, the investigations incorporated considerable uncertainty and the used water indices had misclassification problem, which made different research groups present different results. Thus we first ascertain the boundaries of the AsB, the syr and Amu river basins as well as their upper, middle and lower reaches. Then a four-band index for both liquid and solid water(ILsW) is proposed to address the misclassification problems of the classic water indices. ILsW is calculated by using the reflectance values of the green, red, near infrared, and thermal infrared bands, which combines the normalized difference water index(NDWI) and land surface temperature(LsT) together. Validation results show that the ILsW water index has the highest accuracy by far in the Aral sea Basin. Our results indicate that annual average decline of the water-coverage area was 963 km^(2) in the southern Aral sea, whereas the northern Aral sea has experienced little change. In the meanwhile, permanent ice and snow in upper reach of AsB has retreated considerably. Annual retreating rates of the permanent ice and snow were respectively 6233and 3841 km^(2) in upper reaches of Amu river basin(UARB) and syr river basin(UsRB). One of major reasons is that climate has become warmer in AsB. The climate change has caused serious water deficit problem. The water deficit had an increasing trend since the 1990s and its increasing rates was 3.778 billion m^(3) yearly on average. The total water deficit was 76.967 billion m^(3) on average in the whole area of AsB in the 2010s. However, up reaches of syr river basin(UsRB), a component area of AsB, had water surplus of 25.461 billion m^(3). These conclusions are useful for setting out a sustainable development strategy in AsB.

关键词： Aral sea Basin syr river basin Amu river basin Water indices Water-coverage area Water deficit Climate change

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Use of infrared thermography to detect reactions to stressful events:does animal personality matter?

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Integrative Zoology 2024年第2期19卷 224-239页

作者： Maria Vittoria MAZZAMUTO Marina MORANDINI William LAMPMAN Lucas Armand WAUTERs Damiano PREATONI john Lad KOPROWsKI Adriano MARTINOLI school of Natural Resources and Environment College of Agriculture and Life ScienceUniversity of ArizonaArizonaUSA Unitàdi Analisi e Gestione delle Risorse Ambientali Dipartimento di Scienze Teoriche e ApplicateGuido Tosi Research GroupUniversitàdegli Studi dell’InsubriaVareseItaly Haub school of Environment and Natural Resources University of WyomingWyomingUSA

The study of the relationship between animal stress and personality for free-ranging animals is limited and provides contrasting *** perception of stressors by an individual may vary due to its personality,and certain personality traits may help individuals to better cope with *** non-invasive infrared thermography(IRT),we investigated the link between physiological and behavioral components expressed during an acute stress event by free-ranging Fremont’s squirrels(Tamiasciurus fremonti).We expected that,during the acute stress event of being approached by the researcher,individuals that showed a fast pace-of-life syndrome(bolder,more active,and less social/more aggressive)based on an arena test would exhibit stronger sympathetic-adrenal-medullary system reactivity showing a more intense stress-induced hyperthermia(high core body temperature and low peripheral temperature)than individuals with a slow pace of life(shy,less active,and more social).We successfully employed IRT technology to images of Fremont’s squirrels with identification of the individuals’body parts(eye,nose,ear,hind foot).However,we found no support for our ***’body surface temperatures told us more about a squirrel’s external environment and less about the thermal state of the body in that environment following a stressful *** studies need to assess how to make IRT effective and efficient in the field and improve its performance in studying the relationships between physiology and personality in wildlife.

关键词： non-invasive method open field test physiology stress-induced hyperthermia Tamiasciurus fremonti

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