Thermoluminescence of NaCl:Cu Sintered Phosphors Exposed to Beta Irradiation

R. Bernal,C. Cruz-Vázquez,F. Brown,W. Tostado-García,R. Pérez-Salas,V.M. Castaño 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.4

NaCl:Cu pellet-shaped phosphors were synthesized through a sintering process. Some samples were exposed to beta irradiation in order to investigate their thermoluminescence properties and capabilities to be used in detecting and measuring ionizing radiation. The glow curves reveal at least four thermoluminescence peaks below 250°C, and a main one above 300°C when a 5°C/s heating rate is used. The lowest temperature peak vanishes in less than 3 min after irradiation, giving rise to an intense afterglow luminescence, potentially useful for in situ non-thermoluminescence dosimetry, and the next remains for about 3 h, but the high temperature one exhibits no important changes after that time. The thermoluminescence intensity increased as the radiation dose increased in the 0.417 - 25.0 Gy dose range. Because the position and the remarkable stability of the higher temperature peak, besides the strong afterglow produced by the fast decaying of the lower temperature peak, it is concluded that these phosphors are very suitable candidates to be used in both thermoluminescence and non thermoluminescence dosimetry of ionizing radiation, having advantages over monocrystals of similar composition. The synthesis route here followed can be reproduced in standard college laboratories, and thermoluminescence be measured in home-made systems, allowing design practices for interdisciplinary physics, chemistry electronics, and materials science students.

Epitaxial Multiferroic BiFeO3 Thin Films: Progress and Future Directions

Chu, Y. H.,Martin, L. W.,Zhan, Q.,Yang, P. L.,Cruz, M. P.,Lee, K.,Barry, M.,Yang, S. Y.,Ramesh, R. Taylor Francis 2007 Ferroelectrics Vol.354 No.1

<P> We write this article in honor of Professor Vitaly L. Ginzburg, truly the father of the field of ferroelectricity. This article serves as a review of the current state of research pertaining to multiferroic BiFeO3 thin films. In this review we will delve into details of the growth of BiFeO3 thin films and the use of piezoforce microscopy and x-ray reciprocal space mapping to characterize the crystal structure and domain structure of BiFeO3. We will also discuss the use of vicinal and asymmetric substrates to simplify the domain structure in BiFeO3. By simplifying the domain structure we can, in turn, control the ferroelectric switching mechanisms in BiFeO3. Finally we describe the basic ferroelectric properties of BFO films and discuss the critical issues needed to be solved in BiFeO3 films including leakage, complex domain structure, coercivity, and reliability. Such results are promising for continued exploration for detailed multiferroic-coupling studies in the magnetoelectric BiFeO3 system and BiFeO3, in turn, provides a model platform with which to realize the exciting possibility of electrically control magnetism.</P>

Magnetoelectric complex-oxide heterostructures

Ramesh, R.,Zavaliche, F.,Chu, Y. H.,Martin, L. W.,Yang, S. Y.,Cruz, M. P.,Barry, M.,Lee, K.,Yang, P.,Zhan, Q. Taylor and Francis 2007 Philosophical magazine letters Vol.87 No.3

<P> A short review of recent progress in the field of multiferroic thin films and heterostructures is given. We focus on the bismuth iron oxide system due to its desirable properties, namely high ferroelectric Curie temperature and antiferromagnetic Neel temperature. Epitaxial growth of this model system in various crystallographic orientations has conclusively demonstrated the large ferroelectric polarization in this system. Piezoforce microscopy reveal a complex domain structure, especially on (100) SrTiO3 substrates. Electrical switching experiments show the co-existence of 71°, 109° and 180° domain switching mechanisms in such films. Preliminary work has shown promise for electrically controllable exchange bias in ferromagnet-multiferroic heterostructures.</P>

Antimicrobial Activity of Benzophenones and Extracts from the Fruits of Garcinia brasiliensis

Naldoni, F.J.,Claudino, A.L.R.,Cruz, J.W. Jr,Chavasco, J.K.,Silva, P.M. Faria e,Veloso, M.P.,Santos, M.H. Dos The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.2

The pericarp and seeds from fruits of Garcinia brasiliensis were subjected to extraction with hexane and ethanol. The pericarp hexane extract (PHE) and seed ethanol extract (SEE) were purified by silica gel column chromatography, which permitted isolation of the prenylated benzophenones 7-epiclusianone (1) and guttiferone-A (2), respectively. The antimicrobial activity of PHE, SEE, and compounds 1 and 2 were evaluated against Candida albicans, Staphylococcus aureus, Escherichia coli, and Bacillus cereus cultures. The minimum inhibitory concentration and minimum bactericidal concentration were established. The substances presented activity against S. aureus and B. cereus as follows: PHE, $4.0\;{\mu}g/mL$ and $2.4\;{\mu}g/mL$; SEE, $10.0\;{\mu}g/mL$ and $12.6\;{\mu}g/mL$; 7-epiclusianone, $1.2\;{\mu}g/mL$ and $0.6\;{\mu}g/mL$; and guttiferone-A, $2.4\;{\mu}g/mL$ and $2.4\;{\mu}g/mL$, respectively. The direct relationship between the lipophilic character of the structure and activity in Gram-positive bacteria was specifically observed. Therefore these extracts and prenylated benzophenones represent an interesting topic for further studies and open possibilities for an alternative control of diseases associated with Gram-positive bacteria.

Antimicrobial Activity of Benzophenones and Extracts from the Fruits of Garcinia brasiliensis

F.J. Naldoni,A.L.R. Claudino,J.W. Cruz Jr.,J.K. Chavasco,P.M. Faria e Silva,M.P. Veloso,M.H. Dos Santos 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.2

The pericarp and seeds from fruits of Garcinia brasiliensis were subjected to extraction with hexane and ethanol. The pericarp hexane extract (PHE) and seed ethanol extract (SEE) were purified by silica gel column chromatography, which permitted isolation of the prenylated benzophenones 7-epiclusianone (1) and guttiferone-A (2), respectively. The antimicrobial activity of PHE, SEE, and compounds 1 and 2 were evaluated against Candida albicans, Staphylococcus aureus, Escherichia coli, and Bacillus cereus cultures. The minimum inhibitory concentration and minimum bactericidal concentration were established. The substances presented activity against S. aureus and B. cereus as follows: PHE, 4.0 μg/mL and 2.4 μg/mL; SEE, 10.0 μg/mL and 12.6 μg/mL; 7-epiclusianone, 1.2 μg/mL and 0.6 μg/mL; and guttiferone-A, 2.4 μg/mL and 2.4 μg/mL, respectively. The direct relationship between the lipophilic character of the structure and activity in Gram-positive bacteria was specifically observed. Therefore these extracts and prenylated benzophenones represent an interesting topic for further studies and open possibilities for an alternative control of diseases associated with Gram-positive bacteria.

Grain yield variability and stability of corn varieties in rainfed areas in the Philippines

Anuada Anecito M.,Cruz Pompe C. Sta.,De Guzman Lucille Elna P.,Sanchez Pearl B. 한국작물학회 2022 Journal of crop science and biotechnology Vol.25 No.2

Determining the factors afecting the yield of corn varieties due to genotype by environment (G ×E) interaction can be helpful in the identifcation of sites with contrasting environments for efective multi-location trials. Field experiments were conducted for one cropping season in selected corn-growing areas in the Philippines. Corn varieties used were: (i) IPB Var 6, IPB Var 8, LB Lagkitan, IES Lagkitan, and Native corn in Luzon; (ii) IPB Var 6, IPB Var 11, IPB Var 13, and OxL in Visayas; and (iii) IPB Var 6, LB Lagkitan, and OxL in Mindanao. Climatic parameters, such as temperature, rainfall, and relative humidity in each location were determined. Grain yield variability was obtained as afected by the prevailing climatic factors during the growing period. In Luzon, variations in corn grain yield were mainly attributed to the genotypic efect under Type I climate (distinct dry and wet season), and IPB Var 6 has consistently higher grain yields across sites. The efect of the environment on the grain yield of IPB Var 6, IPB Var 8, LB Lagkitan, IES Lagkitan, and Native variety was apparent under Type IV climate and the diferent corn varieties were not afected by the climatic factors. In the Visayas, relative humidity contributed signifcantly to grain yield variations of four varieties in diferent locations with Type I climate. Varietal diferences in corn grain yield under Type IV climate were attributed to the genotypic efect and IPB Var 13 variety has consistently higher grain yield. Temperature, genotype, and relative humidity contributed signifcantly to the variations in the grain yield of IPB Var 6, OxL, and LB Lagkitan in locations with a Type II climate in Mindanao. On the other hand, genotype and relative humidity signifcantly infuenced the yield performance of three varieties grown in diferent locations with a Type IV climate. In conclusion: (i) IPB Var 6 can be recommended in Luzon under Type I and IV climates, based on yield performance across locations; (ii) IPB Var 13 can be recommended under Type I and IV climates in the Visayas based on grain yield, with IPB Var 11 being the most stable genotype across three locations with Type I and IV climates; and (iii) IPB Var 6 having the highest grain yield under Type II and IV climates in Mindanao, can be recommended in Mindanao, eventhough it has specifc adaptations in some locations.

Piglet colibacillosis diagnosis based on multiplex polymerase chain reaction and immunohistochemistry of paraffin-embedded tissues

Cíntia De Lorenzo,Caroline P. de Andrade,Verônica S. L. Machado,Matheus V. Bianchi,Veronica M. Rolim,Raquel A. S. Cruz,David Driemeier 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.1

Enterotoxigenic Escherichia coli (ETEC) causes diarrhea in pigs, referred to as colibacillosis. The aim of this study was to optimize multiplex polymerase chain reaction (PCR) and immunohistochemistry (IHC) analyses of paraffin-embedded material to detect pathogenic E. coli strains causing colibacillosis in pigs. Multiplex PCR was optimized for fimbriae (F18, F4, F6, F5, and F41) and toxins (types A and B heat-stable toxins [STaP and STb], heat-labile toxin [LT], and type 2 Shiga toxin [STx2e]), and IHC was optimized for an anti-E. coli polyclonal antibody. Samples (132) from pigs received between 2006 and 2014 with clinical and histopathological diagnoses of colibacillosis were analyzed. E. coli was detected by IHC in 78.7%, and at least one virulence factor gene was detected in 71.2%. Pathogenic strains of ETEC with at least one fimbria and one toxin were detected in 40% of the samples in multiplex PCR. The most frequent virulence types were F18-STaP (7.5%), F18-STaP-STb (5.7%), and F4-STaP (3.8%). A statistically significant association was noted between virulence factors F4, F18, STaP, and STb and positive immunostaining results. Colibacillosis diagnosis through multiplex PCR and IHC of paraffin-embedded tissues is a practical approach, as samples can be fixed and stored for long periods before analysis.

Precipitation Hardening and Corrosion Behavior of Friction Stir Welded A6005-TiB2 Nanocomposite

N. Abu‑warda,M. D. López,B. González,E. Otero,M. D. Escalera‑Rodríguez,S. Cruz,P. Rey 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

Precipitation hardening and corrosion behavior of a friction stir welding (FSW) based on the aluminum alloy A6005 reinforcedwith TiB2nanoparticles have been studied. Mechanical alloying (MA) and hot extrusion techniques have beenemployed as processing route followed by FSW. Samples characterization has been performed by DSC and TEM, and precipitationstrengthening of the bulk samples and the FSW joint has been evaluated by micro-hardness tests after T6 thermaltreatment. TEM characterization revealed the presence of Mg–Si hardening phases, mainly of β′ phase, and dispersoids ofα-Al(FeMnCr)Si into the aluminum matrix. The results revealed that samples subjected to MA had less susceptibility toT6 thermal treatment and that the presence of nano-TiB2 reinforcement accelerates aging time. In addition, electrochemicaltests based on polarization tests have been performed in 3.5% NaCl solution to assess the effect of FSW process on corrosionbehavior. The FSW joint had worse corrosion behavior since the passive Al2O3film was not generated on the weldzone. SEM–EDS analysis revealed that pits nucleated mainly in sites with a higher presence of Fe contaminant which actscathodically with respect to the aluminum matrix, producing galvanic corrosion.

Humoral Immune Responses In Experimentally Infected Primates With Mycobacterium Tuberculosis

( Sang Nae Cho ),( E. C. Dela Cruz ),( R. M. Abalos ),( G. P. Walsh ),( Joo Deuk Kim ),( M. A. Horwitz ) 대한결핵 및 호흡기학회 1995 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.81 No.-

Nivolumab in patients with advanced hepatocellular carcinoma (CheckMate 040): an open-label, non-comparative, phase ½ dose escalation and expansion trial

El-Khoueiry, A.B.,Sangro, B.,Yau, T.,Crocenzi, T.S.,Kudo, M.,Hsu, C.,Kim, T.Y.,Choo, S.P.,Trojan, J.,Welling, T.H.,Meyer, T.,Kang, Y.K.,Yeo, W.,Chopra, A.,Anderson, J.,dela Cruz, C.,Lang, L.,Neely, J. J. Onwhyn ; Elsevier Science Ltd 2017 The Lancet Vol.389 No.10088

Background: For patients with advanced hepatocellular carcinoma, sorafenib is the only approved drug worldwide, and outcomes remain poor. We aimed to assess the safety and efficacy of nivolumab, a programmed cell death protein-1 (PD-1) immune checkpoint inhibitor, in patients with advanced hepatocellular carcinoma with or without chronic viral hepatitis. Methods: We did a phase ½, open-label, non-comparative, dose escalation and expansion trial (CheckMate 040) of nivolumab in adults (≥18 years) with histologically confirmed advanced hepatocellular carcinoma with or without hepatitis C or B (HCV or HBV) infection. Previous sorafenib treatment was allowed. A dose-escalation phase was conducted at seven hospitals or academic centres in four countries or territories (USA, Spain, Hong Kong, and Singapore) and a dose-expansion phase was conducted at an additional 39 sites in 11 countries (Canada, UK, Germany, Italy, Japan, South Korea, Taiwan). At screening, eligible patients had Child-Pugh scores of 7 or less (Child-Pugh A or B7) for the dose-escalation phase and 6 or less (Child-Pugh A) for the dose-expansion phase, and an Eastern Cooperative Oncology Group performance status of 1 or less. Patients with HBV infection had to be receiving effective antiviral therapy (viral load <100 IU/mL); antiviral therapy was not required for patients with HCV infection. We excluded patients previously treated with an agent targeting T-cell costimulation or checkpoint pathways. Patients received intravenous nivolumab 0.1-10 mg/kg every 2 weeks in the dose-escalation phase (3+3 design). Nivolumab 3 mg/kg was given every 2 weeks in the dose-expansion phase to patients in four cohorts: sorafenib untreated or intolerant without viral hepatitis, sorafenib progressor without viral hepatitis, HCV infected, and HBV infected. Primary endpoints were safety and tolerability for the escalation phase and objective response rate (Response Evaluation Criteria In Solid Tumors version 1.1) for the expansion phase. This study is registered with ClinicalTrials.gov, number NCT01658878. Findings: Between Nov 26, 2012, and Aug 8, 2016, 262 eligible patients were treated (48 patients in the dose-escalation phase and 214 in the dose-expansion phase). 202 (77%) of 262 patients have completed treatment and follow-up is ongoing. During dose escalation, nivolumab showed a manageable safety profile, including acceptable tolerability. In this phase, 46 (96%) of 48 patients discontinued treatment, 42 (88%) due to disease progression. Incidence of treatment-related adverse events did not seem to be associated with dose and no maximum tolerated dose was reached. 12 (25%) of 48 patients had grade ¾ treatment-related adverse events. Three (6%) patients had treatment-related serious adverse events (pemphigoid, adrenal insufficiency, liver disorder). 30 (63%) of 48 patients in the dose-escalation phase died (not determined to be related to nivolumab therapy). Nivolumab 3 mg/kg was chosen for dose expansion. The objective response rate was 20% (95% CI 15-26) in patients treated with nivolumab 3 mg/kg in the dose-expansion phase and 15% (95% CI 6-28) in the dose-escalation phase. Interpretation: Nivolumab had a manageable safety profile and no new signals were observed in patients with advanced hepatocellular carcinoma. Durable objective responses show the potential of nivolumab for treatment of advanced hepatocellular carcinoma. Funding: Bristol-Myers Squibb.