检索结果-南通市图书馆

Rotating effects on the photoionization cross-section of a 2D quantum ring

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第10期76卷 153-159页

作者： Carlos Magno O Pereira Frankbelson dos s Azevedo luís Fernando C Pereira Edilberto O silva Departamento de Física Universidade Federal do Maranh?o

In this article, we investigate the nonrelativistic quantum motion of a charged particle within a rotating frame, taking into account the Aharonov–Bohm(AB) effect and a uniform magnetic field. Our analysis entails the derivation of the equation of motion and the corresponding radial equation to describe the system. solving the resulting radial equation enables us to determine the eigenvalues and eigenfunctions, providing a clear expression for the energy levels. Furthermore,our numerical analysis highlights the substantial influence of rotation on both energy levels and optical properties. specifically, we evaluate the photoionization cross-section with and without the effects of rotation. To elucidate the impact of rotation on the photoionization process of the system, we present graphics that offer an appealing visualization of the intrinsic nature of the physics involved.

关键词： Aharonov-Bohm effect photoionization cross-section quantum ring rotating effect

Perianal disease in inflammatory bowel disease:Broadening treatment and surveillance strategies for anal cancer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第28期30卷 3373-3385页

作者： Tatiana Pacheco sara Monteiro luísa Barros Jorge silva Department of Gastroenterology Centro Hospitalar do Tamega e SousaPenafiel 4560-136Portugal

The perianal disease affects up to one-third of individuals with Crohn's disease(CD),causing disabling symptoms and significant impairment in quality of life,particularly for those with perianal fistulising CD(PFCD).The collaborative effort between gastroenterologists and surgeons is essential for addressing PFCD to achieve fistula closure and promote luminal *** fistula healing rates with conventional therapies have prompted the emergence of new biological agents,endoscopic procedures and surgical techniques that show promising *** these,mesenchymal stem cells injection is a particularly hopeful *** addition to the burden of fistulas,individuals with perianal CD may face an increased risk of developing anal *** underscores the importance of surveillance programmes and timely interventions to prevent late diagnoses and poor ***,there is no established formal anal screening *** this review,we provide an overview of the current state of the art in managing PFCD,including novel medical,endoscopic and surgical *** discussion also focuses on the relevance of establishing an anal cancer screening programme in CD,intending to propose a risk-based surveillance *** validation of this surveillance programme would be a significant step forward in improving patient care and outcomes.

关键词： Inflammatory bowel disease Crohn's disease Perianal Fistula Anus diseases Management Anal cancer screening

Detection and clearance in Alzheimer’s disease: leading with illusive chemical, structural and morphological features of the targets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第3期19卷 497-498页

作者： luís Gales i3s−Instituto de Investigação e Inovação em saúde Rua Alfredo AllenPortoPortugal(Gales L)IBMC−Instituto de Biologia Molecular e CelularUniversidade do PortoRua Alfredo AllenPortoPortugal ICBAs−Instituto de Ciências Biomédicas Abel salazar Rua de Jorge Viterbo FerreiraPortoPortugal

Highly specific interactions between biomolecules,such as antigen-antibody,protein-ligand,or nucleic acid base pair complementary are on the basis of the organization of complex *** same principles may be tentatively used in molecular medicine for diagnosis and therapeutics.A molecule can be designed to selectively bind a protease and thereby inhibit the production of a peptide that forms toxic aggregates in the brain or an antibody may be produced to bind specifically to that peptide for detection or clearance ***,interference in biological systems is not that *** a start there is the inhibition of the physiological role of the protease;moreover,several cleavage fragments may be produced,which may continue to diverge due to putative post-translational modification and self-assembly processes,hiding the toxic target in a“soup”of peptide species varying in size,structure and chemical composition.A perspective of the current status and challenges in targeting peptide species for diagnosis and treatment in the context of Alzheimer’s disease is given.

关键词： Alzheimer diagnosis thereby

Ferroelectricity Induced by Oxygen Vacancies in Rhombohedral ZrO_(2) Thin Films

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第1期7卷 229-237页

作者： Veniero Lenzi José P.B.silva Břetislav Šmíd Vladimir Matoín Cosmin M.Istrate Corneliu Ghica Judith L.MacManus-Driscoll luís Marques Physics Center of Minho and Porto Universities(CF-UM-UP) University of MinhoCampus de Gualtar 4710-057Braga Portugal Laboratory of Physics for Materials and Emergent Technologies LapMETUniversity of Minho4710-057Braga Portugal Department of surface and Plasma science Faculty of Mathematics and PhysicsCharles UniversityV Holešovičkách 218000Prague 8 Czech Republic National Institute of Materials Physics 105 bis Atomistilor 077125Magurele Romania Department of Materials science and Metallurgy 27 Charles Babbage Rd.Cambridge CB3 OFSUK

Rhombohedral phase Hf_(x)Zr_(1.x)O_(2)(HZO,x from 0 to 1)films are promising for achieving robust ferroelectric polarization without the need for an initial wake-up pre-cycling,as is normally the case for the more commonly studied orthorhombic ***,a large spontaneous polarization observed in rhombohedral films is not fully understood,and there are also large discrepancies between experimental and theoretical *** this work,in rhombohedral ZrO_(2)thin films,we show that oxygen vacancies are not only a key factor for stabilizing the phase,but they are also a source of ferroelectric polarization in the *** is shown experimentally through the investigation of the structural properties,chemical composition and the ferroelectric properties of the films before and after an annealing at moderate temperature(400℃)in an oxygen environment to reduce the V_(o)concentration *** experimental work is supported by density functional theory(DFT)calculations which show that the rhombohedral phase is the most stable one in highly oxygen defective ZrO_(2)*** DFT calculations also show that V_(o)contribute to the ferroelectric *** findings reveal the importance of V_(o)for stabilizing rhombohedral ZrO_(2)thin films with superior ferroelectric properties.

关键词： charged defects ferroelectric polarization rhombohedral phase stability zirconia

Impact Containment Barriers with Geotextile Tubes

在线全文

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2024年第5期12卷 325-344页

作者： Flávio da silva Ornelas luís Fernando Martins Ribeiro Rafael Cerqueira silva Instituto Federal de Educaç &#227o Ci&#234ncia e Tecnologia&#8212IFTO Palmas Brasil Departamento de Engenharia Civil e Ambiental Programa de p&#243s gradua&#231&#227o em Geotecnia Universidade de Bras&#237lia&#8212UnB/Campus Universit&#225rio Darcy Ribeiro Bras&#237lia Brasil

Recently, tragic tailings dam collapses in Brazil have caused deaths and major destruction and the need to develop technologies capable of preventing damage to people and the environment. Brazilian tailings dams are in a situation of uncertainty due to new legislation that even requires decommissioning, an activity that involves many problems and where the risk of failure is the main one. An impact containment structure downstream of these dams can be effective and geotextile tubes, in a new approach, have emerged as an option with advantages in terms of execution, costs and safety. The technology is versatile and can bring many benefits such as the reuse of tailings or filling with low-energy or reused materials. In this research, geotextile tubes were tested as free containment barriers, experiencing impacts in reduced models. The safety factor for the stability of the structure was constructed using an equation which is the ratio between the self-weight of the barrier structure and its coefficient of static friction and the impact pressure, where the data showed an adequate correlation which suggests the viability of mitigating risks.

关键词： Geotextile Tube Debris Flow Barriers Impact Mining

A functional gel polymer electrolyte based on PVDF-HFP/gelatin toward dendrite-free lithium metal batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第4期17卷 2790-2799页

作者： Xiaoyi Hu Kangli Liu shijie Zhang Guosheng shao s.Ravi P.silva Peng Zhang state Center for International Cooperation on Designer Low-carbon and Environmental Materials(CDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China Zhengzhou Materials Genome Institute(ZMGI) ZhongyuanzhiguXingyang 450100China Nanoelectronics Center Advanced Technology InstituteUniversity of SurreyGuildfordGU27XHUK

The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries(LMBs).The appearance of gel polymer electrolyte(GPE)has obviously improved the safety of traditional ***,the limited inhibition of GPE on lithium dendrites is detrimental to the safety of ***,a kind of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)/gelatin(GN)GPE with high ionic conductivity,high-temperature resistance,and flame-retardancy,was prepared by electrospinning and soaking *** the electrospinning network of PVDF-HFP,its affinity to liquid electrolytes,makes this GPE more beneficial to ions transport and the formation of ***,the GN with sol–gel properties,enhances the mechanical property(13.5 MPa)of HFP-GN ***,X-ray photoelectron spectroscopy(XPs)and density functional theory(DFT)suggest that the attraction of polar groups of GN to Li+can regulate the distribution of Li+and protect Li ***,the application of HFP-GN GPEs to LMBs with cathodes of LiFePO_(4) and LiCoO_(2) deliver excellent electrochemical performances:after 300 cycles,the LiFePO_(4)/HFP-GN GPE/Li battery keeps a low capacity decay rate of 0.09%at 5 C;after 400 cycles at 2 C,the LiCoO_(2)/HFP-GN GPE/Li cell retains a high capacity retention of 74%.This GPE is demonstrated for the application prospect of safe LMBs.

关键词： poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP) gelatin polar groups lithium metal battery lithium dendrite

Molecular and cellular mechanisms of neuroprotection by oligopeptides from snake venoms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

BIOCELL 2024年第6期48卷 897-904页

作者： CARLOs ALBERTO-silva BRENDA RUFINO DA silva Natural and Humanities sciences Center Experimental Morphophysiology LaboratoryFederal University of ABC(UFABC)São Bernardo do CampoSão PauloBrazil

Venom snake-derived peptides have multiple biochemical,pharmacological,and toxicological proﬁles,allowing for the discovery of new medicinal products and therapeutic *** review speciﬁcally examines the fundamental elements of neuroprotection offered by different oligopeptides derived from snake *** also includes a brief evaluation of short peptides that are being considered as potential therapeutic ***-rich peptides and tryptophyllin family peptides isolated from the crude venom of Viperidae family snakes,speciﬁcally Bothrops atrox,Bothrops jararaca,and Bothrops moojeni,have been shown to have pro-survival properties,the ability to reduce oxidative stress,and the ability to promote cell viability and mitochondrial *** signiﬁcant mechanisms are related to the neuroprotection mediated by snake venom oligopeptides:(1)Activation of the L-arginine metabolite pathway,such as polyamines from ornithine metabolism,which reduces N-methyl-D-aspartate(NMDA)-type glutamate receptor activity;(2)Enhancement of cell viability by activating the nerve growth factor-signaling pathway;and(3)Activation of the Muscarinic acetylcholine receptor subtype M1(mAChR-M1).These small peptides show promise as neuroprotective agents against a variety of neurodegenerative disorders.

关键词： Neuroprotective peptides Neurodegenerative disease Oxidative stress Reactive oxygen species Biopeptides

High-efficiency prediction method for helicopter global/ground noise based on near-field acoustic holography

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 271-284页

作者： Mengxue sHAO Yang lu Xice XU Jiaxin lu National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Noise reduction program design is an effective approach that relies on efficient noise prediction for reducing ground noise during *** existing noise prediction methods have the limitations of being computationally expensive or only applicable to *** this paper,a High-Efficiency Prediction Method(HEPM)for helicopter global/ground noise based on near-field acoustic holography is *** HEPM can predict the global noise based on acoustic modal analysis and has the advantages of high prediction accuracy and low time *** process is given as follows:firstly,the rotor noise on the holographic surface in the specified flight is obtained by simulations or ***,the global noise model,which maps time-domain noise to acoustic modes,is established based on near-field acoustic holography and Fourier acoustic analysis ***,combined with acoustic modal amplitude,the model established enables efficiently predicting the global/ground noise in the corresponding flight *** verify the accuracy of the prediction method,a simulation study is conducted in hovering and forward flight states using a model helicopter with a 2-meter rotor and Rotor Body Interaction(ROBIN)*** comparison of HEPM with numerical results shows that the average prediction errors of the global and ground noise are less than 0.3 dB and 0.2 dB,*** a region containing 100000 observers,the computation time of the HEPM is only one-fifth of that of the acoustic hemisphere method,demonstrating the rapidity of the proposed method.

关键词： Helicopter Rotor noise prediction Noise abatement procedure design Acoustic modal analysis Near-field acoustic holography

Influence of previous plane of nutrition on molecular mechanisms regulating the expression of urea and water metabolism related genes in the rumen and kidney of finishing crossbred Angus steers

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第2期17卷 232-243页

作者： Aghata E.Moreira da silva Arturo Macias Franco Bradley s.Ferguson Mozart A.Fonseca College of Agriculture Biotechnology&Natural Resources University of Nevada Department of Animal and Range sciences Clayton Livestock Research Center New Mexico State University

This study aimed to understand how molecular mechanisms controlling water and urea metabolism at the finishing phase can be affected by previous plane of nutrition of crossbred Angus beef steers. Twentyfour(n = 24) animals were randomly distributed into either a moderate(MP) or high plane of nutrition during the background phase for 85 d. Animals were then blocked by their previous plane and were moved onto a 105-d finishing phase in a 2 × 2 factorial arrangement. The forage-finished group received only high-quality alfalfa hay, whereas the grain-fed group received a high grain diet(80% whole corn and20% alfalfa hay). By the end of the finishing phase, animals were harvested and tissue samples from the rumen and kidney were collected. Changes in gene expression of aquaporins(AQP)-2,-3,-4,-7, ATP1A1,ATP1B1, sGK1, CLIC1(kidney and rumen), UT-A1(kidney only) and UT-B(rumen only), were assayed via real-time q PCR; 18s r RNA was used as an endogenous control. One-way ANOVA followed by Tukey's post hoc analysis was conducted. When animals were from MP, forage-finishing increased the relative abundance of AQP3(P ≤ 0.05), AQP7(P ≤ 0.05), ATP1B1(P ≤ 0.05), and sGK1(P ≤ 0.05) in the kidney when compared to grain-fed animals. In the rumen, for the MP group, AQP7 was differentially expressed in both treatments at the finishing phase(P ≤ 0.01), with forage-finished steers having the highest expression of AQP7. For the MP group, UT-B had a tendency of presenting a higher expression on grainfed animals(P = 0.075). Overall, these results suggest that previous plane can impact expression of genes associated with water and urea metabolism during the finishing phase, namely AQP3, AQP7, ATP1B1, and sGK1 in the kidney, and AQP7 and UT-B in the rumen. The greatest impact observed on gene expression changes of investigated genes at the finishing phase was reflective of animals backgrounded on the moderate previous plane.

关键词： Gene expression Aquaporin sodium channel Urea transporter