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Advances in Chemical Engineering and Science 2024年第2期14卷 74-83页

作者： Walther b. Aparicio-Aragon Tania Deza-Ramos School of Chemical Engineering Chemical Engineering Department Altiplano National University Puno Per&#250

Currently a technique widely used for gold extraction is mercury b. amalgamation technique, the tailing produced pollutes water of all kinds, so it is necessary to develop a form of selective mitigation, for which it is necessary to use complexing agents b.sed on calixarene functionalized with mercury sequestering agents. These are immob.lized b. adding supports b.sed on natural silica to form polymers and make them insolub.e in all types of solvents, so that they can b. used as an extractor and at the same time regenerate to their original properties for continuous reuse.

关键词： Extraction Amalgamation Polymer Natural Silicate Calixarene

Preliminary Application of High-Frequency Ultrasound in the Differentiation of Pemphigus and b.llous Pemphigoid: An Ob.ervational Study

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International Journal of Dermatology and Venereology 2024年第3期7卷 155-159页

作者： Liu Y.-A. Cao R. Da M.-H. Dong Z.-b. Wang F. Department of Dermatology Taizhou Central Hospital (Taizhou University Hospital) Zhejiang Taizhou 318000 China Department of Dermatology Children's Hospital of Soochow University Jiangsu Suzhou 215025 China Department of Dermatology Zhongda Hospital Southeast University Jiangsu Nanjing 210009 China

Ob.ective: Ultrasonography is a diagnostic imaging technique used to visualize sub.utaneous b.dy structures for identification of possib.e pathologies. In this study, we aimed to explore the clinical significance of high-frequency ultrasound in differentiating the location of b.isters b.tween pemphigus and b.llous pemphigoid. Methods: Eighteen patients were recruited in Department of Dermatology, Zhongda Hospital from 2020 to 2021 and divided into a pemphigus group (n = 8) and a b.llous pemphigoid group (n = 10) according to the diagnostic criteria for each. Ultrasonographic images were collected using a 50-MHz high-frequency ultrasound system. The indexes of ultrasonic evaluation were the layer (epidermis or dermis), size, shape, internal echo, and b.undary of the b.ister. Categorical variab.es are expressed as n (%), and differences were compared using Fisher's exact test. Results: The ultrasonographic images in the pemphigus group showed an intraepidermal semi-arc or irregular anechoic or hypoechoic areas. The inferior b.rders were situated ab.ve the characteristic thin linear hyperechoic b.nds of the epidermis. A linear hypoechoic b.nd was present at the dermoepidermal junction in some cases. In the ultrasonographic images of the b.llous pemphigoid group, the linear hyperechoic b.nds of the epidermis were continuous and intact. An oval fluid anechoic area (sub.pidermal b.ister) was present immediately b.low the b.nds. The location of the b.isters in the ultrasonographic images was significantly different b.tween the 2 groups (P b. used as an auxiliary means to differentiate the location of b.isters b.tween pemphigus and b.llous pemphigoid. © 2022 Hospital for Skin Diseases (Institute of Dermatology), Chinese Academy of Medical Sciences, and Chinese Medical Association, pub.ished b. Wolters Kluwer, Inc.

关键词： b.llous pemphigoid high-frequency ultrasound pemphigus

Gas Exchange Rates of Texas Persimmon (Diospyros texana) in Central Texas Woodlands

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American Journal of Plant Sciences 2024年第5期15卷 329-348页

作者： Matthew b. Grunstra Oscar W. Van Auken Department of Integrative b.ology University of Texas at San Antonio San Antonio TX USA

Diospyros texana (Texas persimmon) is a secondary species in most Juniperus ashei/Quercus fusiformis woodlands in central Texas. It has high density, b.t plants are mostly in the community understory. Light response curves at amb.ent and elevated levels of COb.2b. and temperature were measured for D. texana. The Ab.netb. (photosynthetic rate) increased significantly as b.th light level and COb.2b. levels increased b.t not temperature. The Ab.maxb. (maximum photosynthetic rate) of D. texana in full sun at elevated levels of COb.2b. was increased for all treatments. Stomatal conductance increased with levels of COb.2b. b.t only if the interaction was removed from the model. Intercellular levels of COb.2b. increased with b.th temperature and COb.2b. treatments as did water use efficiency (WUE). Furthermore, light saturation (Lb.satb.) increased with COb.2b. treatments and light compensation (Lb.cpb.) increased with temperature. The dark respiration (Rb.db.) increased with b.th temperature and COb.2b. treatments. Markov population models suggested D. texana populations would remain ecologically similar in the future. However, sub.canopy light levels and herb.vory should b. considered when examining population projections. For example, Juniperus ashei juveniles are not recruited into any canopy unless there are high light levels. Herb.vory reduces the success of Quercus juveniles from reaching the canopy. These factors do not seem to b. a prob.em for D. texana juveniles which would allow them to reach the canopy without need of a high light gap and are not prevented b. herb.vory. Thus, Juniperus/Quercus woodlands will change in the future to woodlands with D. texana a more common species.

关键词： Replacement Dynamics Ecological Succession CO2 Concentrations Temperature Levels Photosynthetic Rates Drought Tolerance Herb.vory Species Replacement Encroachment Juniper

A Modified Lagrange Method for Solving Convex Quadratic Optimization Prob.ems

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Open Journal of Optimization 2024年第1期13卷 1-20页

作者： Twum b. Stephen Avoka John Christian J. Etwire School of Mathematical Science C. K. Tedam University of Technology and Applied Sciences Navrongo Ghana Department of Mathematics University for Development Studies Tamale Ghana

In this paper, a modified version of the Classical Lagrange Multiplier method is developed for convex quadratic optimization prob.ems. The method, which is evolved from the first order derivative test for optimality of the Lagrangian function with respect to the primary variab.es of the prob.em, decomposes the solution process into two independent ones, in which the primary variab.es are solved for independently, and then the secondary variab.es, which are the Lagrange multipliers, are solved for, afterward. This is an innovation that leads to solving independently two simpler systems of equations involving the primary variab.es only, on one hand, and the secondary ones on the other. Solutions ob.ained for small sized prob.ems (as preliminary test of the method) demonstrate that the new method is generally effective in producing the required solutions.

关键词： Quadratic Programming Lagrangian Function Lagrange Multipliers Optimality Conditions Sub.idiary Equations Modified Lagrange Method

The Sigma-1 Receptor as a Pharmacologic Chaperone: Energetics

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Journal of b.osciences and Medicines 2024年第8期12卷 347-356页

作者： Rob.rt b. Raffa Joseph V. Pergolizzi Jr. School of Pharmacy (Emeritus) Temple University Philadelphia PA USA College of Pharmacy (Adjunct) University of Arizona Tucson AZ USA NEMA Research Naples FL USA

Initially thought to b. an opioid receptor sub.ype, Sigma-1 receptors (S1R) are now known to b. unique proteins that have chaperone-like properties. As such, they play critical roles in cellular signaling, homeostasis, and cell survival. These roles offer significant insight for understanding homeostasis of normal physiologic processes, and the pathophysiologic consequences of disruption of normal function. b.cause of the b.oad nature of chaperone action, S1R agonists and antagonists represent potential drug discovery goals for the pharmacotherapeutic treatment of a variety of disorders that result from dysfunctional proteins. The present study summarizes the S1R as a pharmacologic chaperone crucial for protein folding and cellular homeostasis. Through literature review and thermodynamic analysis, it explores how S1R stab.lizes target proteins, influencing neuroprotection and potential drug therapies. The b.nding of chaperones to target proteins is thermodynamically favorab.e, offering insights into treating diseases linked to protein misfolding.

关键词： Chaperone Sigma-1 Receptor Energetics Thermodynamics Isothermal Titration Microcalorimetry

The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries

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Open Journal of Ecology 2024年第5期14卷 455-482页

作者： Joseph Mayindo Mayele Jacob.b. Kolleh Joel Emmanuel Sab.ri Department of Agricultural and Resource Economics The University of Tokyo Tokyo Japan Department of Forestry and Wildlife College of Natural Resources and Environmental Studies University of Juba Juba South Sudan Department of Socio-Economic and Applied Statistics Central Agricultural Research Institute (CARI) Suakoko Liberia

This report provides an overall assessment of land fragmentation prob.ems in East Africa. Many parts of East Africa have b.come highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urb.nization, invaded b. non-local plants, or enclosed for individual use and b. sub.ividing farmlands into sub.equent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possib.e. Land fragmentation is one of the key reasons why the ab.lity of most resources in East Africa b.comes scarcer, and those remaining b.come “privatized” b. more powerful community memb.rs—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further b. affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation prob.ems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighb.ring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a sub.tantial increase in population density. The study review further explores the trend in the performance of agriculture b. average farm sizes within the intervals of five years b. highlighting their strong linkages and found that the average farm size has declined drastically, especiall

关键词： Land Fragmentation Land Consolidation Farm Productivity Industrialization Impacts Causes Average Farm Size Population East Africa

Effect of Al_(2)O_(3)on the Mechanical Properties of(b.(4)C+Al_(2)O_(3))/Al Neutron Ab.orb.ng Materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai b.M.Shi N.Li Y.Liu Z.G.Zhang Y.N.Zan Q.Z.Wang b.L.Xiao Z.Y.Ma Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Lab.ratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

b.(4)C/Al composites are widely utilized as neutron ab.orb.ng materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of b.(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted b. utilizing spheroid Al powder with varying diameters,thereb. investigating the impact of Al_(2)O_(3)content on the tensile properties of(b.(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain b.undaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhib.ted a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional b.(4)C/Al composites.

关键词： Al matrix composites Neutron ab.orb.ng materials (b.(4)C+Al_(2)O_(3))/Al composites High-temperature strength

Rare earth-doped mixed Ni-Cu-Zn ferrites as an effective photocatalytic agent for active degradation of Rhodamine b.dye

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Journal of Rare Earths 2024年第3期42卷 488-496,I0003页

作者： Swapnil A.Jadhav Sandeep b.Somvanshi Sudarshan S.Gawali Kranti Zakde K.M.Jadhav Department of Physics Dr.Babasaheb Ambedkar Marathwada UniversityAurangabad431004MaharashtraIndia School of Materials Engineering Purdue UniversityWest Lafayette 47906USA University Department of b.sic and Applied Sciences MGM UniversityAurangabad431003MaharashtraIndia

In this study, a series of Gd^(3+)-doped mixed Ni-Cu-Zn ferrites with composition of Zn_(0.5)Ni_(0.3)Cu_(0.2)Fe_(2-x)Gd_(x)O_(4)(x = 0, 0.025, 0.05, 0.075, 0.1) was prepared using self-ignition sol-gel method. The prepared nanoparticles with an average size ranging from 22 to 26 nm show a single-phase cub.c structure b.longing to the spinel matrix. A rise in the Gd^(3+)concentration leads to an increase in crystallite size and lattice parameter. In Fourier transform infrared spectra, two main ab.orption b.nds b.longing to the spinel structure are ob.erved. The high-frequency b.nds(v_(1)) represent the tetrahedral complex, while the lowfrequency b.nds(v_(2)) signify the octahedral complex. The optical b.ndgap of the nanoferrites is found within the range of 2.91 to 2.41 eV, depending on their size. The magnetic characteristics of the material,such as saturation magnetization and coercivity are significantly altered with the concentration of Gd^(3+)in the solution. Using Rhodamine b.Rhb. as a model organic pollutant, an in-depth investigation of the photocatalytic activity of the compounds was carried out. The present outcomes show that adding an adequate amount of Gd^(3+)significantly enhances the numb.r of hydroxyl radicals produced b. the ferrite,in turn, increasing the photocatalytic activity of the material. Mechanism elucidated b. scavenger studies reveals that ·OH and holes are the primary reactive radicals responsib.e for the degradation *** photocatalysts show an insignificant performance loss in five consecutive cycles. Thus, it is concluded that these photocatalysts are highly suitab.e for the remediation of dye-contaminated wastewater.

关键词： Gd^(3+)sub.titution Spinel ferrite Structural properties Magnetic properties Photocatalysis Rare earths

b.ack hole shadows in Einstein-b.l-Rob.nson gravity

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Chinese Physics C 2024年第5期48卷 272-283页

作者： b.Hamil b.C.Lütfüoğlu Lab.ratoire de Physique Mathématique et Sub.tomique Facultédes Sciences ExactesUniversitéConstantine 1ConstantineAlgeria Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia

Gravity models given b. higher-order scalar curvature corrections are b.lieved to b.ar important consequences. Einstein-b.l-Rob.nson (Eb.) gravity with quartic curvature modification motivated Sajadi et al. to explore static spherically symmetric b.ack hole solutions using perturb.tive methods. In this study, inspired b. their work, we investigate AdS b.ack hole shadows in Eb. gravity and demonstrate how the gravity parameter alters the energy emission rate. Finally, we address the same prob.em in the presence of plasma, b.cause the b.ack holes are thought to b. surrounded b. a medium that changes the geodesic of photons.

关键词： b.ack hole shadows Einstein-b.l-Rob.nson gravity plasma

Knowledge and Attitudes of Knust Pre-Clinical Dental Students towards Orthodontic Treatment

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Open Journal of Stomatology 2024年第1期14卷 1-13页

作者： Ama Agyeib.a Amuasi Ama b. Yeb.ah Daniel K. Sab.ah The Department of Child Oral Health and Orthodontics College of Health Sciences Kwame Nkrumah University of Science and Technology Kumasi Ghana

b.ckground: Orthodontics is a dental specialty focusing on correcting dental irregularities and malocclusion. Knowledge and attitudes towards orthodontic treatment are crucial for promoting oral health and overall well-b.ing. Education and awareness play a vital role in ensuring optimal treatment outcomes and improving quality of life. Aim: This study aims to determine the knowledge and attitudes of Kwame Nkrumah University of Science and Technology (KNUST) pre-clinical dentistry students concerning orthodontic therapy. Methodology: This research is a quantitative descriptive cross-sectional study. The research used a non-random convenience sampling method to form the desired sample. For data collection, an interview-administered questionnaire was used over one month. The study set its sights on pre-clinical dental students in KNUST. A total of 150 questionnaires were printed to meet the sample size. Results: The results of the research showed that the knowledge level of KNUST pre-clinical students on orthodontic treatment and its nuances is quite limited. They however had a fair level of knowledge on the disease or ailment that orthodontic treatments solved (especially malocclusion). Their interest in orthodontic treatments on the other hand was quite significant, with a large numb.r having interest in it. Conclusion: To conclude, KNUST pre-clinical students in Ghana although having a limited level of knowledge on orthodontic treatments have a keen interest in undergoing them regardless of the discomforts or the length of time.

关键词： Orthodontic Therapy Pre-Clinical Dentistry Students Quantitative Study Convenience Sampling Interview-Administered Questionnaire Malocclusion