110 research outputs found
Electrical properties of cork and derivates
The electrical properties of natural cork, commercial cork agglomerates (for floor and wall covering) and a composite of cork/TetraPak® were studied. The composite was developed at LNEG/Portugal and is made of recycled cork and TetraPak® containers. Measurements of isothermal charge and discharge currents (ICC/IDC) and dielectric relaxation spectroscopy (DRS) were made. The isothermal currents characteristics and the samples electrical conductivity were investigated under different conditions (electric field, temperature and measuring atmosphere). Dielectric relaxation spectroscopy was used to quantify the changes in the permittivity with the samples conditioning. Both experimental techniques showed the strong influence of water content on the electrical properties of cork and its derivatives
The influence of dna repair genes variants
Funding: This research was funded by FCT—Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) through Project UID/BIM/00009/2019—Centre for Toxicogenomics and Human Health.Radioiodine therapy with131I remains the mainstay of standard treatment for well-differentiated thyroid cancer (DTC). Prognosis is good but concern exists that131I-emitted ionizing radiation may induce double-strand breaks in extra-thyroidal tissues, increasing the risk of secondary malignancies. We, therefore, sought to evaluate the induction and 2-year persistence of micronuclei (MN) in lymphocytes from 26131I-treated DTC patients and the potential impact of nine homologous recombination (HR), non-homologous end-joining (NHEJ), and mismatch repair (MMR) polymorphisms on MN levels. MN frequency was determined by the cytokinesis-blocked micronucleus assay while genotyping was performed through pre-designed TaqMan® Assays or conventional PCR-restriction fragment length polymorphism (RFLP). MN levels increased significantly one month after therapy and remained persistently higher than baseline for 2 years. A marked reduction in lymphocyte proliferation capacity was also apparent 2 years after therapy. MLH1 rs1799977 was associated with MN frequency (absolute or net variation) one month after therapy, in two independent groups. Significant associations were also observed for MSH3 rs26279, MSH4 rs5745325, NBN rs1805794, and tumor histotype. Overall, our results suggest that131I therapy may pose a long-term challenge to cells other than thyrocytes and that the individual genetic profile may influence131I sensitivity, hence its risk-benefit ratio. Further studies are warranted to confirm the potential utility of these single nucleotide polymorphisms (SNPs) as radiogenomic biomarkers in the personalization of radioiodine therapy.publishersversionpublishe
Costochondral graft with green-stick fracture used in reconstruction of the mandibular condyle : experience in 13 clinical cases
Since its publication in 1920 by Gillies, costochondral grafts have been used by surgeons to replace an injured mandibular condyle and to reconstruct the temporomandibular joint. This procedure is currently applied in cases of congenital dysplasia, developmental defects, temporomandibular ankylosis, neoplastic disease, osteoarthritis and post-traumatic dysfunction. Over the years, various procedures for the reconstruction with this type of graft have been described. In 1989, Mosby and Hiatt described a technique for setting the graft securely, reducing the space between the graft and the mandibular area. In 1998, Monje and Martín-Granizo developed a variation of this method, enabling a precise adaptation of the costochondral graft to the remaining mandibular ramus. The aim of this study is to evaluate the functional and anatomic results of the costochondral graft treatment by green-stick fracture for reconstruction of the TMJ in the 10 years following the description of this technique. We carry out a retrospective study of thirteen cases of temporomandibular pathology (tumors, ankylosis and hypoplasia) treated during a period of ten years from 1998 to 2008. In all these cases, the technique described by Monje and MartínGranizo was used: removal of the sixth rib, fixation to a titanium mini-plate using screws, making an internal corticotomy in order to obtain a green-stick fracture of the outer cortex, providing adequate adaptation of the graft to the mandibular ramus. The graft was then set in place, attaching it with titanium screws. This technique was successful in achieving optimal ossification, a good interincisal opening and satisfactory cosmetic results. In conclusion, according to our experience, the green-stick fracture for the adaptation of costochondral grafts to the remaining mandibular ramus has presented outstanding results in the surgical treatment of temporomandibular pathology
Decavanadate, decaniobate, tungstate and molybdate interactions with sarcoplasmic reticulum Ca2+-ATPase: quercetin prevents cysteine oxidation by vanadate but does not reverse ATPase inhibition
Recently we demonstrated that the decavanadate (V10) ion is a stronger Ca2+-ATPase inhibitor than other oxometalates, such as the isoelectronic and isostructural decaniobate ion, and the tungstate and molybdate monomer ions, and that it binds to this protein with a 1 : 1 stoichiometry. The V10 interaction is not affected by any of the protein conformations that occur during the process of calcium translocation
(i.e. E1, E1P, E2 and E2P) (Fraqueza et al., J. Inorg. Biochem., 2012). In the present study, we further explore this subject, and we can now show that the decaniobate ion, [Nb10 = Nb10O28]6−, is a useful tool
in deducing the interaction and the non-competitive Ca2+-ATPase inhibition by the decavanadate ion [V10 = V10O28]6−. Moreover, decavanadate and vanadate induce protein cysteine oxidation whereas no effects were detected for the decaniobate, tungstate or molybdate ions. The presence of the antioxidant quercetin prevents cysteine oxidation, but not ATPase inhibition, by vanadate or decavanadate. Definitive
V(IV) EPR spectra were observed for decavanadate in the presence of sarcoplasmic reticulum Ca2+-
ATPase, indicating a vanadate reduction at some stage of the protein interaction. Raman spectroscopy clearly shows that the protein conformation changes that are induced by V10, Nb10 and vanadate are different from the ones induced by molybdate and tungstate monomer ions. Here, Mo and W cause
changes similar to those by phosphate, yielding changes similar to the E1P protein conformation. The putative reduction of vanadium(V) to vanadium(IV) and the non-competitive binding of the V10 and Nb10
decametalates may explain the differences in the Raman spectra compared to those seen in the presence of molybdate or tungstate. Putting it all together, we suggest that the ability of V10 to inhibit the Ca2+-
ATPase may be at least in part due to the process of vanadate reduction and associated protein cysteine oxidation. These results contribute to the understanding and application of these families of mono- and
polyoxometalates as effective modulators of many biological processes, particularly those associated with calcium homeostasis.MA thanks CCMAR; LAEBC and MPMM thank QFM-UC for
financial support. CAO is grateful for a QEII fellowship and
Discovery Project grant (DP110105530) from the Australian
Research Council. WHC acknowledges support from the U.S.
Department of Energy Office of Basic Energy Science via grant
DE-FG02-05ER15693, the National Science Foundation via
EAR-0814242 and an NSF CCI grant through the Center for
Sustainable Materials Chemistry, number CHE-1102637
Thyroid cancer: the quest for genetic susceptibility involving DNA repair genes
The incidence of thyroid cancer (TC), particularly well-differentiated forms (DTC), has been rising and remains the highest among endocrine malignancies. Although ionizing radiation (IR) is well established on DTC aetiology, other environmental and genetic factors may also be involved. DNA repair single nucleotide polymorphisms (SNPs) could be among the former, helping in explaining the high incidence. To further clarify the role of DNA repair SNPs in DTC susceptibility, we analyzed 36 SNPs in 27 DNA repair genes in a population of 106 DTCs and corresponding controls with the aim of interpreting joint data from previously studied isolated SNPs in DNA repair genes. Significant associations with DTC susceptibility were observed for XRCC3 rs861539, XPC rs2228001, CCNH rs2230641, MSH6 rs1042821 and ERCC5 rs2227869 and for a haplotype block on chromosome 5q. From 595 SNP-SNP combinations tested and 114 showing relevance, 15 significant SNP combinations (p < 0.01) were detected on paired SNP analysis, most of which involving CCNH rs2230641 and mismatch repair variants. Overall, a gene-dosage effect between the number of risk genotypes and DTC predisposition was observed. In spite of the volume of data presented, new studies are sought to provide an interpretability of the role of SNPs in DNA repair genes and their combinations in DTC susceptibility.info:eu-repo/semantics/publishedVersio
SARS-CoV-2 air and surface contamination in residential settings
© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.SARS-CoV-2 transmission occurs mainly indoors, through virus-laden airborne particles. Although the presence and infectivity of SARS-CoV-2 in aerosol are now acknowledged, the underlying circumstances for its occurrence are still under investigation. The contamination of domiciliary environments during the isolation of SARS-CoV-2-infected patients in their respective rooms in individual houses and in a nursing home was investigated by collecting surface and air samples in these environments. Surface contamination was detected in different contexts, both on high and low-touch surfaces. To determine the presence of virus particles in the air, two sampling methodologies were used: air and deposition sampling. Positive deposition samples were found in sampling locations above the patient's height, and SARS-CoV-2 RNA was detected in impactation air samples within a size fraction below 2.5 μm. Surface samples rendered the highest positivity rate and persistence for a longer period. The presence of aerosolized SARS-CoV-2 RNA occurred mainly in deposition samples and closer to symptom onset. To evaluate the infectivity of selected positive samples, SARS-CoV-2 viability assays were performed, but our study was not able to validate the virus viability. The presented results confirm the presence of aerosolized SARS-CoV-2 RNA in indoor compartments occupied by COVID-19 patients with mild symptoms, in the absence of aerosol-generating clinical procedures.This Project has been partially supported by Portuguese national funds via Fundação para a Ciência e a Tecnologia—Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES), under Project 679 Research4Covid19, UIDB/04539/2020 and UIDP/04539/2020.info:eu-repo/semantics/publishedVersio
Prototype of an affordable pressure-controlled emergency mechanical ventilator for COVID-19
We present a viable prototype of a simple mechanical ventilator intended as a
last resort to ventilate COVID-19 patients. The prototype implements the
pressure-controlled continuous mandatory ventilation mode (PC-CMV) with
settable breathing rates, inspiration/expiration time ratios and FiO2
modulation. Although safe, the design aims to minimize the use of technical
components and those used are common in industry, so its construction may be
possible in times of logistical shortage or disruption or in areas with reduced
access to technical materials and at a moderate cost, affordable to lower
income countries. Most of the device can be manufactured by modest technical
means and construction plans are provided.Comment: This version differs from version 2 in that it includes toxicological
and bio-safety tests and updated electronic
Dez anos de experiência com artéria torácica interna direita através do seio transverso na revascularização da artéria circunflexa e seus ramos
INSECTICIDE-TREATED BED NETS IN RONDÔNIA, BRAZIL: EVALUATION OF THEIR IMPACT ON MALARIA CONTROL
Use of antipsychotic drugs. A multicentric study of inpatients with acute psychotic disorders
Com o objectivo de caracterizar o padrão e os determinantes de utilização de fármacos antipsicóticos por via intra-muscular em indivíduos hospitalizados por perturbação psicótica aguda, efectuou-se um estudo retrospectivo de 244 indivíduos, admitidos em sete unidades hospitalares de internamento psiquiátrico. Foram seleccionados dois grupos, IM (Intra Muscular) e PO (Via Oral), que nos primeiros três dias de internamento receberam respectivamente medicação antipsicótica por via intramuscular ou por via oral, tendo-se explorado as eventuais diferenças nas áreas demográfica, clínica e terapêutica (com revisão dos casos aos 6 e 12 meses após a alta hospitalar). Os dois grupos foram homogéneos quanto à idade, raça, sexo, idade do início da doença e diagnóstico, tendo-se verificado um número maior de internamentos compulsivos no grupo IM. As perturbações psicóticas mais prevalentes em ambos os grupos foram a esquizofrenia e a perturbação bipolar, não se tendo encontrado qualquer associação entre os diagnósticos iniciais e a via de administração dos fármacos. O tempo de hospitalização foi igual entre grupos, embora nos doentes do grupo IM tivesse sido necessário tomar medidas de precaução especiais com maior frequência. A medicação ansiolítica foi superior no grupo PO nos dias um e dois de hospitalização e igual nos dois grupos no dia três e no dia de alta. A terapêutica anticolinérgica foi semelhante entre os dois grupos. O número de novas hospitalizações, bem como a percentagem de doentes a utilizar medicação antipsicótica, ansiolítica e anticolinérgica, foi semelhante nos dois grupos após 6 e 12 meses de seguimento. Neste estudo, a presença de agitação psicomotora e de comportamentos agressivo/destrutivo na fase inicial do internamento no grupo IM (incluindo o primeiro contacto, maioritariamente feito no serviço de urgência) foram os elementos estatisticamente determinantes da utilização da via intramuscular para a administração dos fármacos antipsicóticos. With the objective of determining the pattern and decision making process in using antipsychotic drugs in patients admitted to hospital for acute psychotic disorder we have made a retrospective analysis in 244 in-patients in 7 hospitals for mental disorders. We have selected two groups, IM and PO, that in the first three days of internment have received either intravenous antipsychotic medication or oral medication; the demographical, clinical and therapeutical differences have been considered (with a review of the cases at 6 and 12 months after discharge from hospital). Homogeneity was considered regarding age, race, gender, age at the onset of the disease and diagnosis; in the IM group there were a larger number of compulsive admissions. The most prevalent psychotic disorders in both groups were schizophrenia and bipolar disorder; with no association being made between the initial diagnosis and drug administration. The hospitalization period was the same for both groups, although in the patients in the IM group the need for special precautions was more frequent. Medication with anxiolytics was higher in the PO group on day 1 and 2 of the hospitalization and the same for the two groups on day 3 and on discharge. The number of new admissions, as well as the percentage of patients taking antipsychotic, anxiolytic and anticholinergic medication was similar in both groups after a period of 6 and 12 months follow-up. In this study, agitation and aggressive/destructive behaviours in the initial phase of hospitalization in the IM group (including the first contact, most of the times on admission at the ER) were statistically significant factors for the use of intramuscular administration of antipsychotic drugs.publishersversionpublishe
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