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Variable-top stem biomass equations at tree-level generated by a simultaneous density-integral system for second growth forests of roble, raulí,and coigüe in Chile

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Journal of Forestry Research 2019年第3期30卷 993-1010页

作者： Carlos valenzuela Eduardo Acuna Alicia Ortega Geronimo Quinonez-Barraza jose Corral-Rivas Jorge Cancino Departamento Manejo de Bosques y Medio Ambiente Facultad de Ciencias ForestalesUniversidad de Concepcion Victoria 631Barrio Universitario4070386 ConcepcionChile Instituto de Bosques y Sociedad Facultad de Ciencias Forestales y Recursos NaturalesUniversidad Austral de ChileCampus Isla Teja5110566 ValdiviaChile Campo Experimental Valle del Guadiana Instituto Nacional de Investigaciones Forestales Agricolas y Pecuarias (INIFAP)km 4.5 Carretera Durango-Mezquital34170 DurangoDGOMexico Instituto de Silvicultura e Industria de la Madera Universidad de Juarez del Estado de Durango34120 DurangoMexico

Variable-top stem biomass models at the tree level for second growth forests of roble (Nothofagus obliqua), rauli(Nothofagus alpina), and coigüe (Nothofagus dombeyi) were fitted by a simultaneous density-integral system, which combines a stem taper model and a wood basic density model. For each model, an autoregressive structure of order 2 and a power equation of residual variance were incorporated to reduce residual autocorrelation and heteroscedasticity, respectively. By using dummy variables in the regression analysis, zonal effects on the parameters in the variable-top stem biomass equations were detected in roble. Consequently, equations for clusters of zones were obtained. These equations presented significant parameters and a high precision in both fitting and validation processes (i.e., CV<11.5% and CVp<11.9%, respectively), demonstrating that they are unbiased. The advantage of these types of functions is that they provide estimates of volume and biomass of sections of the stem, defined between any two points of the stem in the three species. Thus, depending on the final use of the wood and the dimensions of the tree, a stem fraction can be quantified in units of volume and the remaining fraction in units of weight.

关键词： Autocorrelation Density-integral Dummy variables Autoregressive error structure Heteroscedasticity

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Management of cancer patients during COVID-19 pandemic at developing countries

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World Journal of Clinical Cases 2020年第16期8卷 3390-3404页

作者： Jaime González-Montero Guillermo valenzuela Mónica Ahumada Olga Barajas Luis Villanueva Department Faculty of MedicineUniversity of ChileSantiago 70058Chile Department Hospital Clinico Universidad de Chile and Clínica DávilaChile Department Hospital Clinico Universidad de Chile and Fundación Arturo López-PérezChile Department Hospital Clínico Universidad de Chile and Fundación Arturo López-PerezChile

Cancer patient care requires a multi-disciplinary approach and multiple medical and ethical *** care during a pandemic health crisis requires prioritising the use of resources for patients with a greater chance of survival,especially in developing *** coronavirus disease 2019 crisis has generated new challenges given that cancer patients are normally not prioritised for admission in critical care ***,the development of new cancer drugs and novel adjuvant/neoadjuvant protocols has dramatically improved the prognosis of cancer patients,resulting in a more complex decision-making when prioritising intensive care in pandemic *** this context,it is essential to establish an effective and transparent communication between the oncology team,critical care,and emergency units to make the best decisions,considering the principles of justice and ***,cancer treatment protocols must be adapted to prioritise according to oncologic response and *** technologies are powerful tools to optimise cancer care during pandemics,and we must adapt quickly to this new scenario of clinical care and *** this new challenging pandemic scenario,multi-disciplinary work and effective communication between clinics,technology,science,and ethics is the key to optimising clinical care of cancer patients.

关键词： Cancer Oncology Pandemic COVID-19 SARS-CoV-2

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Removal of Aqueous Lead and Copper Ions by Using Natural Hydroxyapatite Powder and Sulphide Precipitation in Cyanidation Process

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Materials Sciences and Applications 2013年第4期4卷 231-237页

作者： josé Refugio Parga Jesús Leobardo valenzuela Víctor Vazquez Mario Rodriguez Héctor Moreno Departament of Chemical Engineering and Metallurgy University of Sonora Hermosillo Mexico Department of Chemistry Institute Technology of Laguna Torreon Mexico Department of Metallurgy and Materials Science Institute Technology of Saltillo Saltillo Mexico

Mining, ore processing, and smelting activities have contaminated soil and water resources with cyanide and heavy metals throughout the world. In-situ chemical immobilization is a remediation technology that decreases the concentrations of dissolved ions of copper cyanide and lead hydroxides by adsorption or precipitation. This study deals, with a process to recover lead hydroxides with natural hydroxyapatite powder and copper cyanide ions with sulphide precipitation from solutions of the cyanidation process. This technology is based on inducing nucleated precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2.5 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 99% with 60 percent of copper purity and the cyanide ions associated with this complex the recovery was 90%. For the elimination of lead hydroxides ions from the aqueous cyanidation process with natural hydroxiapatite powder the recovery was 99%. The abundance of cow bones, its low price and non-aggressive nature towards the environment are advantages for its utilization in point of view of wastewater cleanup and Dore with higher quality.

关键词： Natural Hydroxyapatite Sulphide Precipitation Zinc Cementation

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Growth retardation and severe anemia in children with Trichuris dysenteric syndrome

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Asian Pacific Journal of Tropical Biomedicine 2015年第7期5卷 581-586页

作者： Rina Girard Kaminsky Renato valenzuela Castillo Coralia Abrego Flores Pediatric Department School of Medicine National Autonomous University of Honduras and Service of Parasitology University Hospital Honduras.P.O.Box 1547Tegucigalpa Honduras Pediatric Department School of Medicine National Autonomous University of Honduras Pediatric Psychology Unit University HospitalHonduras

Objective: To document epidemiologic data, clinical manifestations and treatment in hospitalized children with Trichuris dysenteric syndrome from Honduras during 2010-2012. Methods: Severe trichuriasis cases were identified by routine stool examinations from hospitalized patients(12 years old or less). Relevant epidemiologic, clinical and management data were obtained from review of clinical histories in the ward. Results: Of 122 Trichuris infections diagnosed in 11 528(1.0%) stool samples for all ages, 81(66.4%) were identified in the age group 2-12 years old, 21(25.9%) of which were severe(≥ 100 eggs in 2 mg of feces). Thirteen of those 21 patients collaborated in this study. Patients(9 males and 4 females) were of rural precedence, from large poor or very poor families, chronically parasitized, and between 2 and 12 years old. Dysentery of months duration, severe anemia and stunting were common complaints; clinical characteristics associated with heavy Trichuris infections included egg counts from 232-3 520 eggs per direct smear, hemoglobin from 3.4-10.8 g/d L, eosinophilia up to 43%, severe malnutrition and growth stunting. Orally administered drugs mebendazole, albendazole, metronidazole, nitaxozanide, and piperazine were prescribed at different dosages and duration other than recommended; no cure or egg excretion control was exercised before patient release. A range of 340 to about 10 000 worms were recovered after treatment from 8 patients. Conclusions: This report underlines the need for detailed community studies in trichuriasis morbidity, effective treatment assessment and clinical response in severely malnourished parasitized children.

关键词： Anemia Honduras Stunting Trichuris dysentery syndrome

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Passive Strategies for the Prevention of Muscle Wasting During Recovery from Sports Injuries

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Journal of Science in Sport and Exercise 2019年第1期1卷 13-19页

作者： Pedro L.valenzuela Javier S.Morales Alejandro Lucia Physiology Unit Department of Systems BiologySchool of MedicineUniversity of AlcaláCtra.BarcelonaKm 33600.Alcaláde Henares28871 MadridSpain Department of Sport and Health Spanish Agency for Health Protection in Sport(AEPSAD)MadridSpain Faculty of Sport Sciences Universidad Europea de MadridMadridSpain Research Institute of the Hospital 12 de Octubre(“i+12”)MadridSpain Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable MadridSpain

Background Recovery from sport injuries commonly involves a muscle disuse situation(i.e.,reduction in physical activity levels sometimes preceded by joint immobilization)with subsequent negative effects on muscle mass and *** To summarize the current body of knowledge on the effectiveness of different physical strategies that are currently available to mitigate the negative effects of muscle disuse during recovery from sports *** A narrative review was conducted to summarize the information available on neuromuscular electrical stimulation(NMES),blood flow restriction(BFR)and vibration *** The concomitant application of BFR and low-intensity exercise has shown promising results in the prevention of disuse-induced muscle *** benefits might also be obtained with BFR alone(i.e.,with no exercise),but evidence is still ***,which can be applied both passively and synchronously with exercise,can also attenuate most of the negative changes associated with disuse *** turn,the mechanical stimulus elicited by vibration seems effec-tive to reduce the loss of bone mineral density that accompanies muscle disuse and could also provide some benefits at the muscle tissue *** Different physical strategies are available to attenuate disuse-induced negative consequences during recovery from *** interventions can be applied passively,which makes them feasible during the first stages of the ***,it would be advisable to apply these strategies in conjunction with low-intensity voluntary exercise as soon as this is feasible.

关键词： Skeletal muscle Rehabilitation Training Muscle wasting Immobilization Injury

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Bioinspired MXene-Based Soft Actuators Exhibiting Angle-Independent Structural Color

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Nano-Micro Letters 2023年第1期15卷 1-13页

作者： Pan Xue Yuanhao Chen Yiyi Xu Cristian valenzuela Xuan Zhang Hari Krishna Bisoyi Xiao Yang Ling Wang Xinhua Xu Quan Li School of Materials Science and Engineering Tianjin UniversityTianjin 300350People’s Republic of China Institute of Advanced Materials School of Chemistry and Chemical EngineeringTech Key Laboratory for Biomedical ResearchSoutheast Universityand Jiangsu Province HiNanjing 211189People’s Republic of China Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State UniversityKentOH 44242USA

In nature,many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft ***,it is challenging to simultaneously biomimic the angle-independent structural color and shape-morphing capabilities found in the plum-throated cotinga flying ***,we report biomimetic MXene-based soft actuators with angle-independent structural color that are fabricated through controlled self-assembly of colloidal SiO_(2) nanoparticles onto highly aligned MXene films followed by vacuum-assisted infiltration of polyvinylidene fluoride into the *** resulting soft actuators are found to exhibit brilliant,angle-independent structural color,as well as ultrafast actuation and recovery speeds(a maximum curvature of 0.52 mm−1 can be achieved within 1.16 s,and a recovery time of~0.24 s)in response to acetone *** proof-of-concept illustrations,structural colored soft actuators are applied to demonstrate a blue gripper-like bird’s claw that can capture the target,artificial green tendrils that can twine around tree branches,and an artificial multicolored butterfly that can flutter its wings upon cyclic exposure to acetone *** strategy is expected to offer new insights into the development of biomimetic multifunctional soft actuators for somatosensory soft robotics and next-generation intelligent machines.

关键词： Bioinspired soft actuator Angle-independent structural color MXene liquid crystals Soft robotics

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Copper and Cyanide Recovery in Cyanidation Effluents

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Advances in Chemical Engineering and Science 2011年第4期1卷 191-197页

作者： josé R. Parga Jesús L. valenzuela Héctor Moreno Jaime E. Pérez 不详

Cyanidation is the main process for gold and silver recovery from its ores. In this study, a process is proposed to recover copper and cyanide from barren solutions from the Merrill-Crowe cementation process with zinc dust. This technology is based on inducing nucleated precipitation of copper and silver in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2.5 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 97 and 99%, when copper concentration in the influent was 636 and 900 ppm. respectively. In this process (sulphidization-acidification-thickening-HCN recycling), the cyanide associated with copper cyanide complexes, is released as HCN gas under weakly acidic conditions, allowing it to be recycled back to the cyanidation process as free cyanide. Cyanide recovery was 90%. Finally, this procedure was successfully run at Minera William in México.

关键词： Precipitation Cyanide Removal Copper Recovery Cyanidation

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Exercise and quality of life in cancer

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Journal of Sport and Health Science 2023年第4期12卷 489-490页

作者： Carmen Fiuza-Luces Pedro L.valenzuela Alejandro Santos-Lozano Ana Ruiz-Casado Alejandro Lucia Physical Activity and Health Research Group(PaHerg) Research Institute of Hospital 12 de Octubre(‘i+12’)Madrid 28041Spain Department of Systems Biology University of AlcalaMadrid 28871Spain i+HeALTH Research Group Department of Health SciencesEuropean University Miguel de CervantesValladolid 47012Spain Department of Medical Oncology Hospital Universitario Puerta de Hierro MajadahondaInstituto de Investigacion Sanitaria Puerta de Hierro-Segovia de Arana(IDIPHISA)Madrid 28220Spain Faculty of Sport Sciences Universidad Europea de MadridMadrid 28670Spain

Historically,patients with cancer were told to avoid physical *** dogma has changed over the last 2 decades,with an exponential growth in the number of studies showing not only the safety,but also the benefits of regular physical activity/exercise in the cancer continuum,notably for attenuating treatment-related toxicities and side effects.

关键词： cancer patients showing

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Frequency-amplitude behavior in the incipient movement of grains under vibration

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Particuology 2018年第5期16卷 1-9页

作者： Karina A.valenzuela Aracena Jesica G.Benito Luc Oger Irene Ippolito Rodolfo O.Ufiac Ana M.Vidales INFAP.CONICET Departamento de FfsieaFacultad de Ciencias Fisico Matemdticas y NaturalesUniversidad Nacional de San LuisEjerdto de los Andes 950D5700HHWSan LuisArgentina Institut de Physique de Rennes UMR UR1-CNRS 6251Universite de Rennes 1263Avenue du General LeclercCampus de BeaulieuCS 7420535042 Rennes CedexFrance Universidad de Buenos Aires Facultad de IngenierfaGrupo de Medios PorososPaseo Colon 8501063Buenos AiresArgentina

The onset of the movement of particles placed on a horizontal rough surface subject to a vertical sinusoidal vibration is investigated through tracking experiments,theoretical analysis,and numerical simulations. The frequency of vibration needed to move particles decays exponentially with the amplitude of the oscillatory *** behavior is explained through a simple mechanism in which a forced damped harmonic oscillator with a spring constant represents all the interactions between the particle and the *** numerical results compare well with experimental data,demonstrating that the forces included in the numerical calculations suitably account for the main particle response,even though the complexity of the surface is not fully taken into *** the way in which frequency varies with amplitude could be relevant to technological applications such as cleaning of material surfaces.

关键词： Vibration Incipient movement Forced oscillator 3D DEM simulation

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Developing a Business Ethics Curriculum for the Bachelor of Science in Accountancy （BSA） Students of De La Salle University （DLSU）-Manila

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Journal of Modern Accounting and Auditing 2011年第11期7卷 1179-1189页

作者： Marivic valenzuela-Manalo De La Salle University Manila Philippines

In a constantly changing environment, accountants must not only acquire technical accounting knowledge and skills, but also acquire integrity, objectivity and the skills that enable them to take a firm stand in difficult situations. The purpose of this study is to know how to effectively incorporate business ethics in the Bachelor of Science in Accountancy （BSA） curriculum at De La Salle University （DLSU）, Manila. Discussions in this paper focused on the responses of the students on what teaching strategies may prove to be effective when teaching business ethics subjects. Results of this study revealed that students ranked as the most effective the teaching strategy sub-group learning through ethical discussion and collaborative learning followed by the lecture method. Role playing and/or film viewing was ranked third. Inviting guest speaker for practitioner participation, case study method, personal value journals, and service learning were ranked fourth, fifth, sixth and seventh respectively. It is interesting to note that students ranked last/eighth the teaching strategy using the technology-enhanced learning or E-learning when teaching business ethics. This can give us an idea that even though the current generations of students are adept in using the computer and the Internet, they would still prefer actual classroom experiences in learning ethics courses.

关键词： ethics education accounting curriculum teaching strategies business ethics transformative learning

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