Impact of Surface Roughness on the Self-Assembling of Molecular Films onto Gold Electrodes for Label-Free Biosensing Applications

The properties of molecular films assembled over gold electrode surfaces are prone to reflect fabrication characteristics. Here we show the importance of controlling electrode surface characteristics of a gold interface destined to label-free electrochemical biosensing applications and how to decrease the effect of the roughness on the properties of the interface by using redox composite materials within 5 to 10 nm in thickness. This controlling of surface characteristics allows us to fabricate reproducible, disposable printed circuit board microelectrodes for label-free electrochemical capacitive assays, which are specifically aimed at applications in point-of-care molecular diagnostic devices. We demonstrate that both the electrochemical roughness factor and the mechanical roughness root mean square of the surface are useful parameters for the quality control of molecularly assembled films and the chemical modification of the surface. For instance, the measured ionic capacitance of gold interfaces is linear as a function of an electrochemical roughness factor lower than ca. 2. On the other hand, roughness factor values higher than ca. 2 lead to a random ionic capacitance outcome. A similar trend of presenting reproducible or irreproducible electrochemical behaviour, wherein a roughness threshold exists, is perceived for charge transfer resistance whether the interfacial redox activity is blocked with a dielectric molecular layer. It was also demonstrated that redox reversibility of gold interfaces is sensitive to the roughness root mean square. Finally, we also confirmed that if the roughness is controlled below a well-defined threshold or if a film thickness (within 5 to 10 nm) is assembled over the surface, the sensing properties are reproducible in micro-fabricated printed circuit board electrodes used in assaying C-reactive protein in human serum. This is an important upshot that permit the microfabrication of cost-effective microelectrodes for label-free electrochemical capacitive biosensors, within the capability to be further integrated into Lab-on-PCB microsystems

GOOD WATER, BUT FOR WHOM? A STUDY ON THE PERCEPTION OF WATER QUALITY BY AMAZONIAN POPULATIONS

In Brazil different regions have inadequate water and sewage treatment facilities, which can be made worse by the installation of large enterprises. The perception of these populations about the scenario in which they live is of great relevance in this context, the present study has the objective of analyzing the socioenvironmental profile and the perception of the water quality and its relation to health damage by populations resident from the area of Belo Monte hydropower plant. A cross-sectional study was conducted with 268 residents of two cities in the interior of Pará-Brazil and the data were obtained from the application of a semi-structured questionnaire. The results showed that the interviewees had minimal education and were low income. Most interviewees reported having running water in their home. However, 63.1% of the interviewees considered the water provided as organoleptically altered and of poor quality. Of the interviewees, 92.5% stated that their water is mainly from wells; 94.8% perceived a relationship between decreasing water quality and increasing health problems. Of these, 85.2% related to the decrease in water quality with renal problems, 75% with liver problems and 28% with hypertension. About 61.6% of respondents reported concerns about lack of basic sanitation. It is concluded that the populations studied understand the importance of quality water consumption and relate water quality to health problems. Therefore, these results serve as an alert to managers regarding the urgent need to improve the quality of life of this population. Keywords: Pará, sewage systems, drinking water, health, chronic disease.    RESUMO :No Brasil, diferentes regiões têm instalações inadequadas de tratamento de água e esgoto, o que pode ser agravado pela instalação de grandes empresas. A percepção dessas populações sobre o cenário em que vivem é de grande relevância neste contexto, o presente estudo tem como objetivo analisar o perfil socioambiental e a percepção da qualidade da água e sua relação com danos à saúde por populações residentes da área. da usina hidrelétrica de Belo Monte. Um estudo transversal foi realizado com 268 moradores de duas cidades do interior do Pará-Brasil e os dados foram obtidos a partir da aplicação de um questionário semiestruturado. Os resultados mostraram que os entrevistados tinham educação mínima e baixa renda. A maioria dos entrevistados relatou ter água encanada em casa. No entanto, 63,1% dos entrevistados consideraram a água fornecida como organoléptica- mente alterada e de má qualidade. Dos entrevistados, 92,5% afirmaram que a água é proveniente principalmente de poços; 94,8% perceberam uma relação entre diminuir a qualidade da água e aumentar os problemas de saúde. Destes, 85,2% relacionaram-se à diminuição da qualidade da água com problemas renais, 75% com problemas hepáticos e 28% com hipertensão. Cerca de 61,6% dos entrevistados relataram preocupações sobre a falta de saneamento básico. Conclui-se que as populações estudadas entendem a importância do consumo de água de qualidade e relacionam a qualidade da água a problemas de saúde. Portanto, esses resultados servem de alerta para os gestores quanto à necessidade urgente de melhorar a qualidade de vida dessa população. Palavras-chave: Pará, sistemas de esgoto, água potável, saúde, doença crônic

New Materials to Solve Energy Issues through Photochemical and Photophysical Processes: The Kinetics Involved

Kinetic rates of energy production are extremely controlled by the competing processes that occur in systems capable of energy transfer. Besides organic and inorganic compounds already known as electronically actives, supramolecular systems can be thought to form energy transfer complexes to efficiently convert, for instance, light into electricity and the mechanisms for that can be of any kind. Photophysical and photochemical processes can simultaneously occur in such systems to provide energy conversion, by competing mechanisms or collaborative ones. Thus, to investigate the kinetic rates of each process and to understand the dynamics of the electronic excited states population and depopulation in strategically structured materials, can offer important tools to efficiently make use of this not always so evident power of supramolecular materials. In this chapter, we present the state-of-the-art of the use of photophysical processes and photochemical changes, presented by new materials and devices to provide a control of energy transfer processes and enable distinct applications, since energy conversion to sensing and imaging techniques to material characterization

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Presynaptic Dopaminergic Imaging Characterizes Patients with REM Sleep Behavior Disorder Due to Synucleinopathy

Objective: To apply a machine learning analysis to clinical and presynaptic dopaminergic imaging data of patients with rapid eye movement (REM) sleep behavior disorder (RBD) to predict the development of Parkinson disease (PD) and dementia with Lewy bodies (DLB). Methods: In this multicenter study of the International RBD study group, 173 patients (mean age 70.5 ± 6.3 years, 70.5% males) with polysomnography-confirmed RBD who eventually phenoconverted to overt alpha-synucleinopathy (RBD due to synucleinopathy) were enrolled, and underwent baseline presynaptic dopaminergic imaging and clinical assessment, including motor, cognitive, olfaction, and constipation evaluation. For comparison, 232 RBD non-phenoconvertor patients (67.6 ± 7.1 years, 78.4% males) and 160 controls (68.2 ± 7.2 years, 53.1% males) were enrolled. Imaging and clinical features were analyzed by machine learning to determine predictors of phenoconversion. Results: Machine learning analysis showed that clinical data alone poorly predicted phenoconversion. Presynaptic dopaminergic imaging significantly improved the prediction, especially in combination with clinical data, with 77% sensitivity and 85% specificity in differentiating RBD due to synucleinopathy from non phenoconverted RBD patients, and 85% sensitivity and 86% specificity in discriminating PD-converters from DLB-converters. Quantification of presynaptic dopaminergic imaging showed that an empirical z-score cutoff of -1.0 at the most affected hemisphere putamen characterized RBD due to synucleinopathy patients, while a cutoff of -1.0 at the most affected hemisphere putamen/caudate ratio characterized PD-converters. Interpretation: Clinical data alone poorly predicted phenoconversion in RBD due to synucleinopathy patients. Conversely, presynaptic dopaminergic imaging allows a good prediction of forthcoming phenoconversion diagnosis. This finding may be used in designing future disease-modifying trials. ANN NEUROL 2024

Maintenance N-acetyl cysteine treatment for bipolar disorder : a double-blind randomised placebo controlled trial

Background N-acetyl cysteine (NAC) is a glutathione precursor that has been shown to have antidepressant efficacy in a placebo-controlled trial. The current study aimed to investigate the maintenance effects of NAC following eight weeks of open-label treatment for bipolar disorder.Method The efficacy of a double blind randomized placebo controlled trial of 2 g/day NAC as adjunct maintenance treatment for bipolar disorder was examined. Participants (n = 149) had a Montgomery Asberg Depression Rating Score of [greater than or equal to]12 at trial entry and, after eight weeks of open-label NAC treatment, were randomized to adjunctive NAC or placebo, in addition to treatment as usual. Participants (primarily outpatients) were recruited through public and private services and through newspaper advertisements. Time to intervention for a mood episode was the primary endpoint of the study, and changes in mood symptoms, functionality and quality of life measures were secondary outcomes.Results There was a substantial decrease in symptoms during the eight-week open-label NAC treatment phase. During the subsequent double-blind phase, there was minimal further change in outcome measures with scores remaining low. Consequently, from this low plateau, between-group differences did not emerge on recurrence, clinical functioning or quality of life measures.Conclusions There were no significant between-group differences in recurrence or symptomatic outcomes during the maintenance phase of the trial; however, these findings may be confounded by limitations. Trial Registration The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12607000074493)