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A high aspect ratio surface micromachined accelerometer based on a SiC-CNT composite material

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Microsystems & Nanoengineering 2024年第2期10卷 219-230页

作者： Jiarui Mo Shreyas Shankar roberto Pezone Guoqi Zhang Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands

Silicon carbide(SiC)is recognized as an excellent material for microelectromechanical systems(MEMS),especially those operating in challenging environments,such as high temperature,high radiation,and corrosive environments.However,SiC bulk micromachining is still a challenge,which hinders the development of complex SiC MEMS.To address this problem,we present the use of a carbon nanotube(CNT)array coated with amorphous SiC(a-SiC)as an alternative composite material to enable high aspect ratio(HAR)surface micromachining.By using a prepatterned catalyst layer,a HAR CNT array can be grown as a structural template and then densified by uniformly filling the CNT bundle with LPCVD a-SiC.The electrical properties of the resulting SiC-CNT composite were characterized,and the results indicated that the electrical resistivity was dominated by the CNTs.To demonstrate the use of this composite in MEMS applications,a capacitive accelerometer was designed,fabricated,and measured.The fabrication results showed that the composite is fully compatible with the manufacturing of surface micromachining devices.The Young’s modulus of the composite was extracted from the measured spring constant,and the results show a great improvement in the mechanical properties of the CNTs after coating with a-SiC.The accelerometer was electrically characterized,and its functionality was confirmed using a mechanical shaker.

关键词： composite surface electrical

Interleukin 1βreceptor and synaptic dysfunction in recurrent brain infection with Herpes simplex virus type-1

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Neural Regeneration Research 2025年第2期20卷 416-423页

作者： roberto Piacentini Claudio Grassi Department of Neuroscience UniversitàCattolica del Sacro CuoreRomeItaly Fondazione Policlinico Universitario A.Gemelli IRCCSRomeItaly

Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer’s disease.However,the molecular mechanisms underlying this association are not completely understood.Among the molecular mediators of synaptic and cognitive dysfunction occurring after Herpes simplex virus type-1 infection and reactivation in the brain neuroinflammatory cytokines seem to occupy a central role.Here,we specifically reviewed literature reports dealing with the impact of neuroinflammation on synaptic dysfunction observed after recurrent Herpes simplex virus type-1 reactivation in the brain,highlighting the role of interleukins and,in particular,interleukin 1βas a possible target against Herpes simplex virus type-1-induced neuronal dysfunctions.

关键词： herpes simplex virus type 1 interleukin 1β microglia neuroinflammation synaptic dysfunction

Assessment of compressive strength of jet grouting by machine learning

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 102-111页

作者： Esteban Diaz Edgar Leonardo Salamanca-Medina roberto Tomas Departamento de Ingeniería Civil Escuela Politécnica SuperiorUniversidad de AlicanteP.O.Box 99E-03080AlicanteSpain

Jet grouting is one of the most popular soil improvement techniques,but its design usually involves great uncertainties that can lead to economic cost overruns in construction projects.The high dispersion in the properties of the improved material leads to designers assuming a conservative,arbitrary and unjustified strength,which is even sometimes subjected to the results of the test fields.The present paper presents an approach for prediction of the uniaxial compressive strength(UCS)of jet grouting columns based on the analysis of several machine learning algorithms on a database of 854 results mainly collected from different research papers.The selected machine learning model(extremely randomized trees)relates the soil type and various parameters of the technique to the value of the compressive strength.Despite the complex mechanism that surrounds the jet grouting process,evidenced by the high dispersion and low correlation of the variables studied,the trained model allows to optimally predict the values of compressive strength with a significant improvement with respect to the existing works.Consequently,this work proposes for the first time a reliable and easily applicable approach for estimation of the compressive strength of jet grouting columns.

关键词： Jet grouting Ground improvement Compressive strength Machine learning

Highly-sensitive wafer-scale transfer-free graphene MEMS condenser microphones

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Microsystems & Nanoengineering 2024年第1期10卷 267-275页

作者： roberto Pezone Sebastian Anzinger Gabriele Baglioni Hutomo Suryo Wasisto Pasqualina M.Sarro Peter G.Steeneken Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands Infineon Technologies AG Am Campeon 1-15Neubiberg 85579Germany Kavli Institue of Nanoscience Department of Quantum NanoscienceDelft University of TechnologyDelftthe Netherlands Department of Precision and Microsystems Engineering(PME) Delft University of TechnologyDelftThe Netherlands

Since the performance of micro-electro-mechanical system(MEMS)-based microphones is approaching fundamental physical,design,and material limits,it has become challenging to improve them.Several works have demonstrated graphene’s suitability as a microphone diaphragm.The potential for achieving smaller,more sensitive,and scalable onchip MEMS microphones is yet to be determined.To address large graphene sizes,graphene-polymer heterostructures have been proposed,but they compromise performance due to added polymer mass and stiffness.This work demonstrates the first wafer-scale integrated MEMS condenser microphones with diameters of 2R=220-320μm,thickness of 7 nm multi-layer graphene,that is suspended over a back-plate with a residual gap of 5μm.The microphones are manufactured with MEMS compatible wafer-scale technologies without any transfer steps or polymer layers that are more prone to contaminate and wrinkle the graphene.Different designs,all electrically integrated are fabricated and characterized allowing us to study the effects of the introduction of a back-plate for capacitive read-out.The devices show high mechanical compliances C_(m)=0.081-1.07μmPa^(−1)(10-100×higher than the silicon reported in the state-of-the-art diaphragms)and pull-in voltages in the range of 2-9.5 V.In addition,to validate the proof of concept,we have electrically characterized the graphene microphone when subjected to sound actuation.An estimated sensitivity of S_(1kHz)=24.3-321 mV Pa^(−1)for a V_(bias)=1.5 V was determined,which is 1.9-25.5×higher than of state-of-the-art microphone devices while having a~9×smaller area.

关键词： transfer plate approaching

Ventriculo-atrial shunt with occlusion of the internal jugular vein: operative experience and surgical technique

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中华神经外科杂志(英文) 2024年第2期10卷 1-8页

作者： Quintero Silvia Tatiana ramirez-Velandia Felipe Moreno Andres Felipe Hortua Vera Lina Rugeles Paula Gonzalez Rafael Augusto Azuero Pontificia Universidad Javeriana Clinica Medilaser S.A.S. Clinica Chicamocha Bucaramanga Santander Colombia Neurology and Neurosurgery Research Group Pontificia Universidad Javeriana Bogotá D.C. Colombia Universidad Industrial de Santander Clinica Chicamocha Bucaramanga Colombia Universidad Autónoma de Bucaramanga Clinica Chicamocha Bucaramanga Colombia Clinica Chicamocha Bucaramanga Santander Colombia

Background Ventricular shunts are one of the most frequent techniques used for the management of hydrocephalus. The ventriculoperitoneal shunt (VPS) is the most commonly performed procedure, and the ventriculoatrial shunt (VAS) is the second option in most medical centers. The main objective of this study is to introduce and describe a surgical approach for VAS outlining our experience and comparing it with traditional shunting techniques.Methods In this retrospective cohort comparison study, we included patients with hydrocephalus treated with a surgical procedure between January 2010 and February 2021 at a single academic institution. We categorized the procedures into two groups: patients with VPS and conventional VAS grouped together into the conventional technique (CT) group, and the second group was patients with whom we performed VAS with complete internal jugular vein occlusion (IJVOT). We compared the surgical time, postoperative complications, and occurrence of shunt failure among the groups by performing univariate analysis using the Fisher exact test.Results Out of the 106 patients included in the analysis, IJVOT was performed in 66 patients, and CT in 40 patients. The median surgical time was 60 min (IQR 60-90) for IJVOT versus 100 min (IQR 60-120) for CT (p < 0.01). In the follow-up a month after the procedure, 83.3% of patients with IJVOT and 62.5% of patients with CT did not require shunt removal or shunt revision (p < 0.01). Shunt revision rates were 12.5% and 1.5% for CT while 1.5% and 2.5% for IJVOT at 1 and 6 months after the procedure.Conclusion Our findings demonstrate that VAS with IJVOT is a safe method that exhibited shorter surgical times and outcomes comparable to CT. However, since the present study represents the first cohort evaluating IJVOT, it is imperative to conduct larger prospective studies, along with clinical trials, to fully explore and establish efficacy, long-term outcomes, and an in-depth comparison among shunting techniques.

关键词： Hydrocephalus Ventriculoatrial shunting Internal jugular vein Operative time Complications Shunt removal

Nutrient restriction-activated Fra-2 promotes tumor progression via IGF1R in miR-15a downmodulated pancreatic ductal adenocarcinoma

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Signal Transduction and Targeted Therapy 2024年第3期9卷 1132-1146页

作者： Gian Luca Rampioni Vinciguerra Marina Capece Luca Reggiani Bonetti Giovanni Nigita Federica Calore Sydney Rentsch Paolo Magistri roberto Ballarin Fabrizio Di Benedetto Rosario Distefano roberto Cirombella Andrea Vecchione Barbara Belletti Gustavo Baldassarre Francesca Lovat Carlo M.Croce Department of Cancer Biology and Genetics and Comprehensive Cancer Center The Ohio State UniversityColumbus 43210 OHUSA Department of Clinical and Molecular Medicine Faculty of Medicine and PsychologySant’Andrea HospitalUniversity of Rome“Sapienza”Rome 00189Italy Department of Diagnostic Clinic and Public Health MedicineUniversity of Modena and Reggio EmiliaModena 41100Italy Hepato-pancreato-biliary Surgery and Liver Transplantation Unit University of Modena and Reggio EmiliaModena 41100Italy Division of Molecular Oncology Centro di Riferimento Oncologico di Aviano(CRO)Istituto di Ricovero e Cura a Carattere Scientifico(IRCCS)National Cancer InstituteAviano 33081Italy

Pancreatic ductal adenocarcinoma(PDAC)is a lethal disease,characterized by an intense desmoplastic reaction that compresses blood vessels and limits nutrient supplies.PDAC aggressiveness largely relies on its extraordinary capability to thrive and progress in a challenging tumor microenvironment.Dysregulation of the onco-suppressor miR-15a has been extensively documented in PDAC.Here,we identified the transcription factor Fos-related antigen-2(Fra-2)as a miR-15a target mediating the adaptive mechanism of PDAC to nutrient deprivation.We report that the IGF1 signaling pathway was enhanced in nutrient deprived PDAC cells and that Fra-2 and IGF1R were significantly overexpressed in miR-15a downmodulated PDAC patients.Mechanistically,we discovered that miR-15a repressed IGF1R expression via Fra-2 targeting.In miR-15a-low context,IGF1R hyperactivated mTOR,modulated the autophagic flux and sustained PDAC growth in nutrient deprivation.In a genetic mouse model,Mir15aKO PDAC showed Fra-2 and Igf1r upregulation and mTOR activation in response to diet restriction.Consistently,nutrient restriction improved the efficacy of IGF1R inhibition in a Fra-2 dependent manner.Overall,our results point to a crucial role of Fra-2 in the cellular stress response due to nutrient restriction typical of pancreatic cancer and support IGF1R as a promising and vulnerable target in miR-15a downmodulated PDAC.

关键词： IGF1R Fra miR

Therapeutic targeting of cellular prion protein: toward the development of dual mechanism anti-prion compounds

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Neural Regeneration Research 2025年第4期20卷 1009-1014页

作者： Antonio Masone Chiara Zucchelli Enrico Caruso Giovanna Musco roberto Chiesa Laboratory of Prion Neurobiology Department of NeuroscienceIstituto di Ricerche Farmacologiche Mario Negri IRCCSMilanItaly Biomolecular NMR Unit Division of Genetics and Cell BiologyIRCCS Ospedale San RaffaeleMilanItaly Department of Biotechnology and Life Sciences University of InsubriaVareseItaly

PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different pathogenic conformations(prion strains),which can be resistant to potential drugs,or acquire drug resistance,posing challenges for the development of effective therapies.Since PrPCis the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity,it represents an attractive therapeutic target fo r prion diseases.In this minireview,we briefly outline the approaches to target PrPCand discuss our recent identification of Zn(Ⅱ)-Bn PyP,a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action.We argue that in-depth understanding of the molecular mechanism by which Zn(Ⅱ)-Bn PyP targets PrPCmay lead toward the development of a new class of dual mechanism anti-prion compounds.

关键词： anti-prion drug anti-PrPC antibody antisense oligonucleotide neurodegeneration pharmacological chaperone porphyrin prion disease PrPC degrader PrPC shedding zinc finger repressor

ChatGPT and exercise prescription:Human vs.machine or human plus machine?

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Journal of Sport and Health Science 2024年第5期13卷 661-662页

作者： Timothy Gustavo Cavazzotto Diego Bessa Dantas Marcos roberto Queiroga Department of Physical Education Midwestern Parana State UniversityParana 85040-167Brazil Postgraduate Program in Physical Education UEM-UEL State University of LondrinaParana 86057-970Brazil

The power of artificial intelligence(AI)to create stories,music,art,and other creative projects has been demonstrated and criticized over recent decades in media,mainly because of the idea that AI will replace human jobs.Most recently,in November 2022,reactions to Chat Generative Pre-training Transformer(ChatGPT)release for public use reverberated in news and social media headlines,while its users exceeded100 million in just a few weeks.ChatGPT is a natural language processing program created by AI non-profit OpenAI Inc.

关键词： prescription replace Human

Nickel-based cerium zirconate inorganic complex structures for CO_(2)valorisation via dry reforming of methane

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Journal of Environmental Sciences 2024年第6期140卷 12-23页

作者： Juan Luis Martín-Espejo Loukia-Pantzechroula Merkouri Jesús Gándara-Loe José Antonio Odriozola Tomas ramirez Reina Laura Pastor-Pérez Department of Inorganic Chemistry and Material Sciences Institute of Seville University of Seville-CSICSeville 41092Spain Department of Chemical and Process Engineering University of SurreyGuildford GU27XHUnited Kingdom

The increasing anthropogenic emissions of greenhouse gases(GHG)is encouraging extensive research in CO_(2)utilisation.Dry reforming of methane(DRM)depicts a viable strategy to convert both CO_(2)and CH4into syngas,a worthwhile chemical intermediate.Among the different active phases for DRM,the use of nickel as catalyst is economically favourable,but typically deactivates due to sintering and carbon deposition.The stabilisation of Ni at different loadings in cerium zirconate inorganic complex structures is investigated in this work as strategy to develop robust Ni-based DRM catalysts.XRD and TPR-H2analyses confirmed the existence of different phases according to the Ni loading in these materials.Besides,superficial Ni is observed as well as the existence of a CeNiO_(3)perovskite structure.The catalytic activity was tested,proving that 10 wt.%Ni loading is the optimum which maximises conversion.This catalyst was also tested in long-term stability experiments at 600and 800℃in order to study the potential deactivation issues at two different temperatures.At 600℃,carbon formation is the main cause of catalytic deactivation,whereas a robust stability is shown at 800℃,observing no sintering of the active phase evidencing the success of this strategy rendering a new family of economically appealing CO_(2)and biogas mixtures upgrading catalysts.

关键词： CO_(2)conversion Dry reforming of methane Nickel catalysts Pyrochlore Cerium zirconate