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Exploring the synthesis conditions to control the morphology of gold-iron oxide heterostructures

Nano Research 2019年第8期12卷 1781-1788页

作者： Pablo Tancredi Luelc Souza da Costa Sebastian Calderon Oscar moscoso-Londono leandro m. Socolovsky Paulo J. Ferreira Diego muraca Daniela Zanchet marcelo Knobel Laboratory of Amorphous Solids INTECINFaculty of EngineeringUniversity of Buenos Aires - CONICETBuenos AiresCP C1063ACVArgentina department of Inorganic Chemistry Institute of ChemistryUniversity of Campinas (UNICAMP)CP615413083-970CampinasSPBrazil Brazilian Nanotechnology National Laboratory (LNNano) Rua Giuseppe Maximo Scolfaro 10000CampinasSPBrazil International Iberian Nanotechnology Laboratory (INL) Av. Mestre Jose Veiga s/n4715-330 BragaPortugal “Gleb Wataghin” Institute of Physics University of Campinas (UNICAMP)CEP 13083-859CampinasSPBrazil Autonomous University of manizales Antigua Estacion del FerrocarrilManizalesCP 170001Colombia Facultad Regional Santa Cruz Universidad Tecnoldgica Nacional - CIT Santa Cruz (CONICET)- Av delos Inmigrantes 555Rio GallegosSanta CruzArgentina materials Science and Engineering Program The University of Texas at AustinAustinTexas 78712USA

Gold-iron oxide nano-heterostructures with a clear and well-defined morphology were prepared via a seed-assisted method. The synthesis process and the events of heterogeneous nucleation during the decomposition of the iron precursor were carefully studied in order to understand the mechanism of the reaction and to tailor the architecture of the fabricated heterostructures. When employing Au seeds of 3 and 5 nm, nanoparticles with a dimer-like morphology were produced due to the occurrence of a single iron oxide nucleation event. Otherwise, multi-nucleation events could be favored by two mechanisms:(i) by the incorporation of a reducing agent and the slowing down of the heating protocol, leading to a core-shell system;(ii) by the increase of the Au seed size to 8 nm, leading to a flower-like system. Further increase of the Au seed size to 12 nm using similar synthesis conditions promotes the homogeneous nucleation and growth of the iron oxide phase, without formation of heterostructures. An in-depth study was performed on the gold-iron oxide heterostructures to confirm the epitaxial growth of the oxide domain over the Au seed and to analyze the elemental distribution of the components within the heterostructures. Finally, it was found that the modification of the plasmonic properties of the Au nanoparticles are strongly influenced by the architecture of the heterostructure, with a more pronounced damping effect for the systems produced after multi-nucleation events.

关键词： nanoparticles gold-iron oxide heterostructures heterogeneous nucleation epitaxial growth HR-microscopy

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The role of physical properties in explosive welding of copper to stainless steel

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defence Technology（防务技术） 2023年第4期22卷 88-98页

作者： G.H.S.F.L.carvalho I.Galvao R.mendes R.m.Leal A.B.moreira A.Loureiro Univ Coimbra CEMMPREDepartamento de Engenharia Mec^anicaRua Luís Reis Santos3030-788CoimbraPortugal department of Industrial Engineering University of FirenzeVia di Santa Marta 350139FirenzeItaly ISEL Departamento de Engenharia Mec^anicaInstituto Politecnico de LisboaRua Conselheiro Emídio Navarro 11959-007LisboaPortugal Univ Coimbra ADAILEDAPDepartamento de Engenharia Mec^anicaRua Luís Reis Santos3030-788CoimbraPortugal LIDA-ESAD.CR Instituto Politecnico de LeiriaRua Isidoro Inacio Alves de Carvalho2500-321Caldas da RainhaPortugal Univ.Porto LAETA/INEGIDept.Eng.Metalúrgica e de MateriaisR.Dr.Roberto Frias4200-465PortoPortugal

This paper investigates the effects of the physical properties on the microstructure and weldability of explosive welding by joining two metals with a significant contrast in thermophysical properties:stainless steel and *** welds between stainless steel and copper were obtained,and the interfacial morphology was wavy,regardless of the position of the *** weldability of dissimilar pairs was found to be more dependent on the relationship between the physical properties of the base materials than on the absolute value of the material *** there is a significant difference in thermal conductivity between the flyer and the base plate,together with a material with a low melting temperature,the weldability of the pair is often *** relative position of the plates affects the interfacial microstructure even when similar morphologies are *** the metallic pairs studied,the wave size was bigger for the configuration in which the ratio between the density of the flyer and the density of the base plate is *** same phenomenon was observed for the impedance:bigger waves were found for a smaller ratio between the impedance of the flyer and the impedance of the base plate.

关键词： Explosive welding Solid-state Copper-stainless steel Dissimilar Interface morphology Weldability

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Ternary supramolecular quantum-dot network flocculation for selective lectin detection

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Nano Research 2016年第7期9卷 1904-1912页

作者： maria Oikonomou Junyou Wang Rui Rijo carvalho Aldrik H. Velders Laboratory of BioNanoTechnology WageningenUR Dreijenplein 6 6703 HB Wageningen the Netherlands micronit microfluidics B.V. Colosseum 15 7521 PV Enschede the Netherlands Interventional molecular Imaging Laboratory Department of Radiology Leiden University Medical Center 2333 ZA Leiden the Netherlands

We present a versatile, tuneable, and selective nanoparficle-based lectin biosensor, based on flocculation of ternary supramolecular nanoparticle networks （NPN）, formed through the sequential binding of three building blocks. The three building blocks are ^-cyclodextrin-capped CdTe quantum dots, tetraethylene glycol-tethered mannose-adamantane cross-linkers （ADTEGman）, and the tetravalent lectin Concanavalin A （ConA）. The working principle of this selective sensor lies in the dual orthogonal molecular interactions of the linker, uniting adamantane-^-cyclodextrin and mannose-lectin interaction motifs, respectively. Only when the lectin is present, sequential binding takes place, leading to in situ self-organization of the sensor through the formation of ternary supramolecular networks. monitoring the loss of fluorescence signal of the quantum dots in solution, caused by controlled network formation and consecutive flocculation and sedimentation, leads to selective, qualitative, and quantitative lectin detection. Fluorescent sedimented networks can be observed by the naked eye or under UV illumination for a lectin concentration of up to 10 8 m. Quantitative detection is possible at 100 min with a lower detection limit of approximately 5 × 10 ^-8 m.

关键词： supramolecular cyclodextrin quantum dot sensor lectin flocculation

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A carbon- and oxygen-isotope record of recent environ- mental change from Qinghai Lake, NE Tibetan Plateau

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Chinese Science Bulletin 2003年第14期48卷 1463-1468页

作者： A.C.G.Henderson J.A.Holmes ZHANGJiawu m.J.Leng L.R.carvalho EnvironmentalChangeResearchCentre(ECRC) DepartmentofGeographyUniversityCollegeLondon26BedfordWayLondonWC1H0APUK CenterforAridenvironmentandPaleoclimateResearch NationalLaboratoryofWesternChina'sEnvironmentalSystemsLanzhouUniversityLanzhou730000China NERCIsotopeGeosciencesLaboratory(NIGL) BritishGeologicalSurveyKeyworthNottingham.NG125GGUK Presentaddress:CentreforEcologyandHydrology(CEH) EdinburghBushEstatePenicuikMidlothianEH260OB.UK

A c. 300-year oxygen and carbon isotope record derived from fine-grained and ostracod carbonate from Qinghai Lake testifies to dramatic interannual tointerdecadal limnological change. Fine-grained carbonates, which are mainly authigenic, are likely to have formed in the epilimnion of the lake and their isotopic composition reflects the summer temperature and, more importantly, the isotopic composition of the near-surface waters, which is mainly a function of evaporative concentration. Ostracod shells are secreted in the benthos of the lake, and their isotopic composition reflects summer bottom-water conditions, together with fractionation effects, which may differ between species. Differences betweencontemporaneous values from authigenic carbonates and ostracod shells may provide an indication of stratification within the lake and variations in effective precipitation over the northeast part of the Tibetan Plateau over the past 300 years. A period of m.derate evaporative concentration, from about 300 to 100 yr BP, was interrupted by a marked wet phase from ～100 to 40 yr BP, which was in turnfollowed by a return to drier conditions in the most recent part of the *** increase in ? 18O values in the latter part of the record accords well withinstrumental records of lake-level lowering and salinity increase since about 1955 AD.

关键词：中国西藏东北部环境变化碳同位素氧同位素季风古气候青海湖

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Sward Structural Characteristics and Performance of Beef Heifers Reared under Rotational Grazing management on Campos Grassland

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American Journal of Plant Sciences 2014年第7期5卷 1020-1029页

作者： Cezar Wancura Barbieri Fernando Luiz F. de Quadros Felipe Jochims émerson mendes Soares leandro Bittencourt de Oliveira Régis maximiliano R. carvalho Gabriela machado Dutra Felipe Xavier de Lima Franciele Gusatto Natural Grassland Ecology Research Group (LEPAN-UFSm) Universidade Federal de Santa Maria Animal Science Department Santa Maria Brazil

This study aimed to evaluate the effect of two rest intervals on structural sward characteristics and productive performance of beef heifers reared on Campos grassland managed on rotational grazing. The treatments were two intervals between grazing of 375 and 750 DD (degree days), based on thermal cumulative sum for leaf expansion of native grasses belonging to two functional groups. The experimental design was a randomized complete block design with two treatments and three replications. The tested animals were beef heifers with initial age of 12 months and average weight of 185.2 ± 17.4 kg. measures in the pasture were: herbage mass, mass of green leaf blades, stem mass, dead material mass and green leaf allowance. The 750 DD rest interval presented higher herbage mass (24%), higher green herbage mass and 19% more leaves in the canopy. This rest interval also presents a high proportion of dead material and stems in the sward structure. In the other way, the 375 DD rest interval presents better chemical characteristics, with 20% more crude protein in the hand plucking samples. Heifers’ dry matter intake was similar between the rest intervals (2.04% of live weight) and the bite mass was also similar (0.22 g Dm per bite) but the animal performance was higher in the 375 DD rest interval. The stocking density showed similarity between treatments with an average of 875 kg/LW/ha. The live weight gain per area was higher in 40 kg/LW/ha (P = 0.117) for 375 DD rest interval, reaching 251 kg/LW/ha produced over the 149 experimental days. Based on these results, we can conclude that the treatment of shortest interval between defoliation gave the highest gain individual animals in warm seasons.

关键词： Average Daily Gain Duration of Leaf Expansion Herbage mass Rotational Grazing Stocking Rate

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Nutritional supplements use in high-performance athletes is related with lower nutritional inadequacy from food

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Journal of Sport and Health Science 2016年第3期5卷 368-374页

作者： mónica Sousa maria J.Fernandes Pedro carvalho José Soares Pedro moreira Vitor Hugo Teixeira Centre of Research Education Innovation and Intervention in Sport Faculty of Sport University of Porto Faculty of Nutrition and Food Sciences University of Porto Research Centre on Physical Activity Health and Leisure Faculty of Sport University of Porto

Background: The use of nutritional supplements(NS) among athletes is widespread. However, little is known about the relationship between nutritional adequacy and NS usage. The aims of this study were to evaluate the NS usage and to compare the nutritional intake from food and prevalence of micronutrient inadequacy(PmI) between NS users and ***: Portuguese athletes from 13 sports completed an NS usage questionnaire and a semi-quantitative food-frequency questionnaire assessing information over the previous 12 months. The estimated average requirement cut-point method was used to calculate PmI. General linear m.dels were used to compare nutritional intake and NS usage. Chi-squared tests and logistic regression were performed to study, respectively,relationships and associations between PmI and NS ***: From the 244 athletes(66% males, 13–37 years), 64% reported NS usage. After adjustment, NS users showed a higher intake from food(p der, for energy, and for 7 of the 17 studied nutrients. The highest PmI were seen for vitamins D and E, calcium, folate,and magnesium. After adjustment, NS users, irrespective of gender, reported lower PmI for calcium(OR = 0.28, 95%CI: 0.12–0.65), and female users for magnesium(OR = 0.06, 95%CI: 0.00–0.98).Conclusion: Athletes using NS reported a higher nutritional intake from food, and a lower PmI for several nutrients. Perhaps, those who were taking NS were probably the ones who would least benefit from it.

关键词： Carbohydrates minerals Proteins Sport Vitamins

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Role of Genetic Ancestry in Oropharyngeal Squamous-Cell Carcinoma: A Cross-Sectional Study in Brazil

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Journal of Biosciences and medicines 2023年第1期11卷 150-161页

作者： Chrystiano de Campos Ferreira Ricardo Ribeiro Gama Ana Carolina de carvalho Iara Santana Raiany S. carvalho debora S. de A. e Silva Lais m. de Jesus Rui m. Reis Rozany Dufloth department of Head and Neck Surgery Barretos Cancer Hospital S&atilde o Paulo Brazil department of medicine Federal University of Rond&ocirc nia Rond&ocirc nia Brazil molecular Oncology Research Center Barretos Cancer Hospital S&atilde o Paulo Brazil department of Pathology Barretos Cancer Hospital S&atilde o Paulo Brazil Life and Health Sciences Research Institute (ICVS) Medical School University of Minho Braga Portugal Institute of Anatomical Pathology Rede D’Or S&atilde o Luiz Hospitals Network S&atilde o Paulo Brazil

Background: HPV infection represents an important etiologic factor for Oropharyngeal Squamous Cell Carcinoma (OPSCC). The different ethnic backgrounds could be related to different susceptibility to Human Papillomavirus (HPV). The aim of our study was to assess the whole of genetic ancestry in HPV status in OPSCC patients. methods: We conducted a cross-sectional study on patients with OPSCC admitted to the Barretos Cancer Hospital, Brazil from 2014 to 2019. Of these, DNA extraction was performed on 40 patients and genetic ancestry was assessed using a specific panel of 46 informative ancestry markers. Results: We observed a predominance of European ancestry (63%), followed by African (18%), Amerindian (9%) and Asian (8%) both in the OPSCC HPV-positive and HPV-negative group. We did not find any statistically significant differences between the HPV-positive and HPV-negative OPSCC groups in relation to European (p = 0.499), African (p = 0.448), Asian (p = 0.275) or Amerindian (p = 0.836) ancestry. Conclusions: We found a predominance of European ancestry, both in the HPV-positive and HPV-negative groups. In our study, we did not find statistically significant differences between HPV-positive or HPV-negative groups in relation to ancestry.

关键词： Oropharyngeal Neoplasms Genetic Ancestry HPV Head and Neck Neoplasms P16

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Renal function after laparoscopic cholecystectomy and analgesia with tramadol and dipyrone or ketorolac

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Health 2013年第11期5卷 35-41页

作者： Tiago Pechutti m.deiros Pedro Thadeu Galvao Vianna Leopoldo muniz da Silva Lidia Raquel de carvalho Gilberto Elias Wady leandro Gobbo Braz Yara marcondes machado Castiglia Graduate Program in Anesthesiology Botucatu Medical SchoolUNESP-Universidade Estadual PaulistaBotucatuBrazil department of Anesthesiology Botucatu Medical SchoolUNESP-Universidade Estadual PaulistaBotucatuBrazil Sao Luiz Hospital Sao PauloBrazil department of Biostatics Institute of BiosciencesUNESP-Universidade Estadual PaulistaBotucatuBrazil mercy Hospital Sao CarlosBrazil

Background: Laparoscopic cholecystectomy (LC) reduces surgical trauma and hospital stay, but requires effective and safe postoperative analgesia. This prospective and double-blind study investigated the effects of analgesia with tramadol combined with either dipyrone or ketorolac on the postoperative renal function of patients submitted to LC. methods: Pre-and post-operatively (PO), estimated glomerular filtration rates (GFR), obtained by two formulas dependent on blood Cr and one on blood cystatin C values, and tubular enzymuria—alkaline phosphatase (AP), γ-glutamiltransferase (γ-GT)— were determined in well hydrated patients who underwent LC and analgesia with tramadol combined with either dipyrone (Dipyrone, n = 63) or ketorolac (Ketorolac, n = 63). Upon discharge from the post-anesthetic care unit (PACU), pain (through Verbal Numerical Scale—VNS) and need for rescue analgesia with morphine were evaluated. Results: There was hemodilution PO, which m.de GFR profile analysis more difficult—those dependent on Cr increased and statistically correlated, but those dependent on cystatin C did not change. There was a significant PO increase in AP in the Dipyrone and Ketorolac groups, and in the product of the both enzymes in the Ketorolac group. Upon PACU discharge, the Dipyrone group showed signifi cantly higher VNS scores than the Ketorolac group. All patients received morphine PO, and the total dose needed for pain control differed between groups, but without statistical significance. Conclusions: The association of tramadol with dipyrone or ketorolac in well hydrated patients submitted to LC had similar analgesic effectiveness in the PACU. Postoperatively, the effect on GFR may have been masked by hemodilution, and enzymuria was discreetly enhanced when ketorolac was used.

关键词： Kidney Function Tests Pneumoperitoneum Biological markers Cystatin C Ketorolac Analgesia

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Aberrant DNA methylation reprogramming during induced pluripotent stem cell generation is dependent on the choice of reprogramming factors

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Cell Regeneration 2014年第1期3卷 30-43页

作者： Aline C Planello Junfeng Ji Vivek Sharma Rajat Singhania Faridah mbabaali Fabian müller Javier A Alfaro Christoph Bock Daniel D de carvalho Nizar N Batada Campbell Family Cancer Research Institute Ontario Cancer InstitutePrincess Margaret Cancer CentreUniversity Health NetworkTorontoON M5G 2 M9Canada department of morphology Piracicaba Dental SchoolUniversity of CampinasPiracicabaSPBrazil Ontario Institute for Cancer Research TorontoOntario M4G 0A3Canada Center of Stem Cell and developmental Biology Zhejiang UniversityHangzhouZhejiang Province 310058China National Cancer Institute NIHBethesdaMD 20892USA department of medical Biophysics University of TorontoTorontoON M5G 2 M9Canada max Planck Institute for Informatics Campus E1.466123 SaarbrückenGermany Cemm Research Center for molecular medicine of the Austrian Academy of Sciences Lazarettgasse 141090 ViennaAustria department of Laboratory medicine Medical University of ViennaWähringer Gürtel 18-201090 ViennaAustria

The conversion of somatic cells into pluripotent stem cells via overexpression of reprogramming factors involvesepigenetic rem.deling. DNA methylation at a significant proportion of CpG sites in induced pluripotent stem cells(iPSCs) differs from that of embryonic stem cells (ESCs). Whether different sets of reprogramming factors influencethe type and extent of aberrant DNA methylation in iPSCs differently remains unknown. In order to help resolvethis critical question, we generated human iPSCs from a common fibroblast cell source using either the Yamanakafactors (OCT4, SOX2, KLF4 and cmYC) or the Thomson factors (OCT4, SOX2, NANOG and LIN28), and determinedtheir genome-wide DNA methylation profiles. In addition to shared DNA methylation aberrations present in all ouriPSCs, we identified Yamanaka-iPSC (Y-iPSC)-specific and Thomson-iPSC (T-iPSC)-specific recurrent ***, not only were the genomic locations of the aberrations different but also their types: reprogrammingwith Yamanaka factors mainly resulted in failure to demethylate CpGs, whereas reprogramming with Thomsonfactors mainly resulted in failure to methylate CpGs. Differences in the level of transcripts encoding DNmT3b andTET3 between Y-iPSCs and T-iPSCs may contribute partially to the distinct types of aberrations. Finally, de novoaberrantly methylated genes in Y-iPSCs were enriched for NANOG targets that are also aberrantly methylated insome cancers. Our study thus reveals that the choice of reprogramming factors influences the amount, location,and class of DNA methylation aberrations in iPSCs. These findings may provide clues into how to produce humaniPSCs with fewer DNA methylation abnormalities.

关键词： SOX2 programming Thomson

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3D Printing Technology for Tapered Optical Fiber Protection With Gas Sensing Possibilities

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Photonic Sensors 2020年第4期10卷 298-305页

作者： Kaleb Roncatti de SOUZA Jonas H.OSÓRIO Juliana B.carvalho Beatriz mota LImA Cristiano m.B.CORdeIRO Gleb Wataghin Physics Institute State University of CampinasCampinas 13083-970Brazil

We present a new procedure for protecting micro-optical fibers(tapered fibers)by using the 3-dimensional(3D)printing technology.A standard single-m.de optical fiber was tapered down to the diameter of 1mm and embedded in a polymeric matrix obtained by an additive manufacturing *** show that the proposed structure protects the fiber taper against environmental humidity while keeping permeability to gas flow and the possibility of the realization of gas detection *** our knowledge,this is the first time 3D printed casings were applied to protect fiber tapers from humidity *** envisage this new approach will allow the development of new fiber taper devices to better resist in humid environments.

关键词： 3D printing additive manufacturing optical fiber tapered fibers sensing

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