Synergy of shaped-induced enhanced Raman scattering to improve surface-enhanced Raman scattering signal in the thiram molecule detection.

Herein, we explore the combined effect of Shaped-Induced Enhanced Raman Scattering (SIERS) and Surface-Enhanced Raman Scattering (SERS) for detecting thiram molecules. We fabricated V-shaped microchannels on a silicon (100) substrate through a standard lithography and etching process. The analysis of SIERS@SERS was performed for Si-V substrates modified with AuNRs with different thiram concentrations, 10-7 to 10-10 mol/L. The spectra were collected for different regions of the Si-V substrates, i.e., in the inside, edge, between (flat top), and far from Si-V (coffee-ring AuNRs aggregation) to assess the performance of Si-V microchannels obtained. The IDMAP statistical projection reveals a higher silhouette coefficient of 0.91 for the inside of Si-V, indicating a more excellent spectral reproducibility with closer relative intensities. The device platform used in this study stands out as a robust option for commercial sensors, demonstrating exceptional sensitivity in detecting a diverse range of molecules, even at low concentrations.

EVALUATION OF THE OMENTUM AS A STEM CELL DONOR ISCHEMIC MYOCARDIAL THROUGH CD34 IMMUNOHISTOCHEMICAL ANALYSIS / AVALIAÇÃO DO OMENTO COMO DOADOR DE CÉLULAS TRONCO NO MIOCÁRDIO ISQUÊMICO ATRAVÉS DA ANÁLISE IMUNOHISTOQUÍMICA DO CD34

Background: Cardiovascular diseases are the leading cause of death in the world. The use of hematopoietic precursor cells and recent advances made in heart graft bioengineering offer a new therapeutic modality for post-myocardial infarction (MI)  and cardiac tissue regeneration. CD34 is a marker expressed on all hematopoietic and endothelial precursor cells, and functions as a cell adhesion factor. The antibody corresponding to this marker is used in immunohistochemistry to assess the formation of new vessels and the presence of stem cells. Aim: To evaluate the efficacy of omentopexy as stem cell donor, on previously infarcted myocardium, using immunohistochemically analysis of CD34. Method: Myocardial infarction was generated in four pigs, by ligature of the 1st and 2nd marginal branches of the circumflex artery. In three animals, abrasion of the infarcted epicardium was performed followed by multiple myocardial perforations and the mobilization of the omentum from the abdominal cavity to the mediastinum, sutured on the infarcted area. In the fourth animal, omentopexy was not performed and only the abrasion and perforation of the infarcted area were performed. All hearts were removed for CD34 immunohistochemically evaluation. Results:  In the samples from the group submitted to omentopexy, there was a 60% increase in angiogenesis, and in the samples from the control animal there was minimal staining.  Four samples from different sites of each animal, totaling 16 histopathological samples were evaluated. All samples were immunolabelled for CD34. Conclusions: Omentopexy proved to be effective in seeding previously infarcted myocardium with stem angiogenic cells, seen through immunohistochemistry, using CD34 marker.

Racional: As doenças cardiovasculares são a principal causa de morte no mundo. O uso de células precursoras hematopoiéticas e os recentes progressos feitos na bioengenharia de enxertos cardíacos oferecem uma nova modalidade terapêutica para a regeneração do tecido cardíaco pós-infarto do miocárdio (IM). O CD34 é um marcador expresso em todas as células precursoras hematopoiéticas e endoteliais, e funciona como fator de adesão celular. O anticorpo que correspondente a este marcador é utilizado na imunohistoquímica para avaliar a formação de novos vasos e a presença de células-tronco. Objetivo: O estudo teve por objetivo avaliar a eficácia da omentopexia na neovascularização e na doação de células tronco de corações suínos previamente infartados, a partir da análise imunohistoquímica do CD34. Método: O infarto do miocárdio foi gerado em 4 suínos, por ligadura do 1°e 2° ramos marginais da artéria circunflexa. Em 3 animais realizou-se abrasão cuidadosa do epicárdio infartado seguido de múltiplas perfurações miocárdicas e a mobilização do omento da cavidade abdominal para o mediastino, envolvendo a área infartada e as perfurações. No quarto animal não foi realizado a omentopexia sendo realizado apenas a abrasão e perfuração da área infartada. Todos os animais foram eutanasiados ao 30º dia pós operatório e os corações retirados para avaliação macroscópica, microscópica e Imunohistoquímica do CD34. Resultados: Nas amostras do grupo submetido a omentopexia, ocorreu um aumento de 60% da angiogênese, sendo que nas amostras do animal controle houve marcação mínima. Foram avaliadas quatro amostras de diferentes sítios de cada coração dos animais, totalizando 16 amostras histopatológicas. Todas as amostras foram imunomarcadas para CD-34. Conclusões: O omento mostrou-se eficiente na indução de neovascularização pela presença de células tronco, vista através da marcação do CD34, demonstrando grande potencial como futura terapêutica para restaurar áreas de miocárdio isquêmico.

TISSUE RESPONSES AND HEALING PATTERN OF PERIOSTAL DEFECTS IN CALVARY BETWEEN TWO TYPES OF MEMBRANES PRODUCED THROUGH BIOENGINEERING: STUDY IN RABBITS / RESPOSTAS TECIDUAIS E PADRÃO DE CICATRIZAÇÃO DE DEFEITOS PERIOSTAIS NA CALVÁRIA ENTRE DOIS TIPOS DE MEMBRANAS PRODUZIDAS POR MEIO DE BIOENGENHARIA: ESTUDO EM COELHOS

Introduction: Simultaneously with the development of new biomaterials, numerous surgical modalities have been proposed, with the aim of promoting adequate regeneration of bone defects, without providing fenestrations or dehiscence. Among the regenerative techniques currently accepted for this purpose, guided tissue regeneration (GTR) stands out. Objective: To evaluate the healing pattern and the histological response of the organism to the insertion of a type A gelatin-based membrane, and to compare it with a commercial membrane. Methods: Fifteen adult rabbits were selected. In the parietal region of the calvaria, flaps were performed to create a supraperiosteal pouch and implantation of 2 types of resorbable membranes: Marquette membrane and Bio-Gide® membrane. After the surgical procedure, the animals were allocated into 3 randomly selected groups (n=5) for the period of euthanasia, which occurred at 2, 4 and 6 postoperative weeks. Subsequently, the calvaria areas were removed and stained by H&E and analyzed for periosteum formation, inflammatory infiltrate in the area of membrane insertion, membrane degradation/resorption, and perimembrane fibrosis. Results: A slight inflammatory infiltration occurred around the Bio-Gide® membrane and it underwent resorption during the postoperative period with periosteum reconstruction, predominantly of a fibrous nature. The Marquette membrane also did not trigger an important inflammatory reaction. However, there was no significant resorption during the period; there was also significant formation of fibrous capsule surrounding the entire membrane area. Conclusion: The Marquette membrane produces tissue isolation reaction, minimizing periosteal formation while not providing its degradation

Introdução: Simultaneamente ao desenvolvimento de novos biomateriais, abundantes modalidades cirúrgicas têm sido propostas, com a finalidade de promover adequada regeneração de defeitos ósseos, sem proporcionar 2 fenestrações ou deiscências. Entre as técnicas regenerativas atualmente aceitas para este propósito, destaca-se a regeneração tecidual guiada (RTG). Objetivo: Avaliar o padrão de cicatrização e a resposta histológica do organismo frente à inserção de uma membrana a base de gelatina tipo A, e compará-la com membrana comercial. Métodos: Foram selecionadas 15 coelhas adultas. Na região parietal da calvária foram realizados retalhos para criação de uma bolsa supraperiostal e implantação de 2 tipos de membranas reabsorvíveis: membrana Marquette e membrana Bio-Gide®. Após o procedimento cirúrgico os animais foram alocados em 3 grupos randomicamente selecionados (n=5) para o período de eutanásia, que ocorreu em 2, 4 e 6 semanas pós-operatórias. Posteriormente, as áreas da calvária foram removidas e coradas por H&E e analisadas para averiguar formação de periósteo, infiltrado inflamatório na área de inserção de membrana, degradação/reabsorção da membrana, e fibrose perimembranar. Resultados: Ao redor da membrana Bio-Gide® ocorreu discreta infiltração inflamatória e a membrana sofreu reabsorção ao decorrer do período pósoperatório com reconstrução de periósteo prevalentemente de caráter fibroso. A membrana Marquette também não desencadeou importante reação inflamatória. Contudo, não foi verificada reabsorção significativa durante o período, também ocorreu significante formação de cápsula fibrosa cerceando toda área membranar. Conclusão: A membrana Marquette produz reação de isolamento tecidual, minimizando a formação periostal ao mesmo tempo que não proporciona sua degradação.

VEGETABLE CELLULOSE NANOFIBER DRESSING AIDS IN THE HEALING PROCESS OF THIRD-DEGREE BURNS? STUDY ON RATS.

BACKGROUND: The treatment of 3rd degree burns represents a major medical challenge. Pinus vegetable cellulose is a biomaterial with characteristic similar to bacterial cellulose. AIM: To evaluate the safety of cellulose membrane (Pinus sp) in the treatment of 3rd burns in rats and to compare its effectiveness with the bacterial membrane already on the market. METHOD: Thirty-three Wistar rats were beaten with a 3rd degree burn on back skin by applying water at 98º C for 30 s. Then, they were divided into three groups (n=11): group 1 - simple dressing with gauze; group 2 - dressing with bacterial cellulose membrane; and group 3 - dressing with vegetable cellulose membrane. The animals were maintained for 15 days to check the general clinical status, macroscopic aspect, contraction of the wounds and microscopic analysis for the degree of healing and collagenization. RESULTS: They were clinically well during the experiment. During the removal of the dressing, there was bleeding in the wound of the control group, unlike the groups treated with cellulose membranes, which protected the bed from injury. The macroscopic evaluation showed a greater contraction of the wounds treated with the membranes in relation to the control. A microscopic analysis revealed that most of the wounds were in advanced healing degree with predominance of mature collagen in all groups. CONCLUSION: Pinus sp cellulose membrane showed efficacy similar to that of the bacterial membrane in the treatment of 3rd degree burns.

Reorganization Energy upon Controlled Intermolecular Charge-Transfer Reactions in Monolithically Integrated Nanodevices.

Intermolecular electron-transfer reactions are key processes in physics, chemistry, and biology. The electron-transfer rates depend primarily on the system reorganization energy, that is, the energetic cost to rearrange each reactant and its surrounding environment when a charge is transferred. Despite the evident impact of electron-transfer reactions on charge-carrier hopping, well-controlled electronic transport measurements using monolithically integrated electrochemical devices have not successfully measured the reorganization energies to this date. Here, it is shown that self-rolling nanomembrane devices with strain-engineered mechanical properties, on-a-chip monolithic integration, and multi-environment operation features can overcome this challenge. The ongoing advances in nanomembrane-origami technology allow to manufacture the nCap, a nanocapacitor platform, to perform molecular-level charge transport characterization. Thereby, employing nCap, the copper-phthalocyanine (CuPc) reorganization energy is probed, ≈0.93 eV, from temperature-dependent measurements of CuPc nanometer-thick films. Supporting the experimental findings, density functional theory calculations provide the atomistic picture of the measured CuPc charge-transfer reaction. The experimental strategy demonstrated here is a consistent route towards determining the reorganization energy of a system formed by molecules monolithically integrated into electrochemical nanodevices.

Silicon Microchannel-Driven Raman Scattering Enhancement to Improve Gold Nanorod Functions as a SERS Substrate toward Single-Molecule Detection.

The investigation of enhanced Raman signal effects and the preparation of high-quality, reliable surface-enhanced Raman scattering (SERS) substrates is still a hot topic in the SERS field. Herein, we report an effect based on the shape-induced enhanced Raman scattering (SIERS) to improve the action of gold nanorods (AuNRs) as a SERS substrate. Scattered electric field simulations reveal that bare V-shaped Si substrates exhibit spatially distributed interference patterns from the incident radiation used in the Raman experiment, resulting in constructive interference for an enhanced Raman signal. Experimental data show a 4.29 increase in Raman signal intensity for bare V-shaped Si microchannels when compared with flat Si substrates. The combination of V-shaped microchannels and uniform aggregates of AuNRs is the key feature to achieve detections in ultra-low concentrations, enabling reproducible SERS substrates having high performance and sensitivity. Besides SIERS effects, the geometric design of V-shaped microchannels also enables a "trap" to the molecule confinement and builds up an excellent electromagnetic field distribution by AuNR aggregates. The statistical projection of SERS spectra combined with the SIERS effect displayed a silhouette coefficient of 0.83, indicating attomolar (10-18 mol L-1) detection with the V-shaped Si microchannel.

Vegetable cellulose nanofiber dressing aids in the healing process of third-degree burns? study on rats / Curativo de nanofibras de celulose vegetal auxilia na cicatrização de queimaduras de terceiro grau? estudo em ratos

ABSTRACT Background: The treatment of 3rd degree burns represents a major medical challenge. Pinus vegetable cellulose is a biomaterial with characteristic similar to bacterial cellulose. Aim: To evaluate the safety of cellulose membrane (Pinus sp) in the treatment of 3rd burns in rats and to compare its effectiveness with the bacterial membrane already on the market. Method: Thirty-three Wistar rats were beaten with a 3rd degree burn on back skin by applying water at 98º C for 30 s. Then, they were divided into three groups (n=11): group 1 - simple dressing with gauze; group 2 - dressing with bacterial cellulose membrane; and group 3 - dressing with vegetable cellulose membrane. The animals were maintained for 15 days to check the general clinical status, macroscopic aspect, contraction of the wounds and microscopic analysis for the degree of healing and collagenization. Results: They were clinically well during the experiment. During the removal of the dressing, there was bleeding in the wound of the control group, unlike the groups treated with cellulose membranes, which protected the bed from injury. The macroscopic evaluation showed a greater contraction of the wounds treated with the membranes in relation to the control. A microscopic analysis revealed that most of the wounds were in advanced healing degree with predominance of mature collagen in all groups. Conclusion: Pinus sp cellulose membrane showed efficacy similar to that of the bacterial membrane in the treatment of 3rd degree burns.

RESUMO Racional: O tratamento das queimaduras de 3˚ grau representa grande desafio na área médica. A celulose vegetal de pinus é biomaterial com características semelhantes às da celulose bacteriana. Objetivo: Avaliar a segurança da membrana de celulose vegetal (Pinus sp) no tratamento de queimaduras de terceiro grau em ratos e comparar sua eficácia com a da membrana bacteriana já comercializada. Método: Trinta e três ratos Wistar foram submetidos à queimadura de 3º grau na pele do dorso mediante aplicação de água a 98º C durante 30 s. Em seguida, foram distribuídos em três grupos (n=11): grupo 1 - curativo simples com gaze; grupo 2 - curativo com membrana de celulose bacteriana; e grupo 3 - curativo com membrana de celulose vegetal . Os animais foram avaliados durante 15 dias para verificar o estado clínico geral, aspecto macroscópico, contração das feridas e análise microscópica pelo grau de cicatrização e colagenizacao. Resultados: Permaneceram clinicamente bem durante o experimento. Durante a retirada do curativo houve sangramento na ferida do grupo controle, diferentemente dos grupos tratados com as membranas de celulose, que protegeram o leito da lesão. A análise microscópica mostrou que a maioria das feridas apresentava-se em grau avançado de cicatrização, com predomínio de colágeno maduro em todos os grupos. Houve maior contração das feridas tratadas com as membranas em relação ao grupo controle. Conclus ão: A membrana de celulose de Pinus sp apresentou eficácia semelhante à da membrana bacteriana no tratamento de queimaduras de 3˚ grau.

Conductive Metal-Organic Framework Thin Film Hybrids by Electropolymerization of Monosubstituted Acetylenes.

1-Hexyne monomers were potentiostatically electropolymerized upon confinement in 1D channels of a surface-mounted metal-organic framework Cu(BDC) (SURMOF-2). A layer-by-layer deposition method allowed for SURMOF depostition on substrates with prepatterned electrodes, making it possible to characterize electrical conductivity in situ, i.e., without having to delaminate the conductive polymer thin film. Successful polymerization was evidenced by mass spectroscopy, and the electrical measurements demonstrated an increase of the electrical conductivity of the MOF material by 8 orders of magnitude. Extensive DFT calculations revealed that the final conductivity is limited by electron hopping between the conductive oligomers.

Self-assembled ultra-compact energy storage elements based on hybrid nanomembranes.

Self-assembly methods combined with standard top-down approaches are demonstrated to be suitable for fabricating three-dimensional ultracompact hybrid organic/inorganic electronic devices based on rolled-up nanomembranes. Capacitors that are self-wound and manufactured in parallel are almost 2 orders of magnitude smaller than their planar counterparts and exhibit capacitances per footprint area of around 200 microF/cm(2). This value significantly exceeds that which was previously reported for metal-insulator-metal capacitors based on Al(2)O(3), and the obtained specific energy (approximately 0.55 Wh/kg) would allow their usage as ultracompact supercapacitors. By incorporating organic monolayers into the inorganic nanomembrane structure we can precisely control the electronic characteristics of the devices. The adaptation of the process for creating ultracompact batteries, coils and transformers is an attractive opportunity for reducing the size of energy storage elements, filters, and signal converters. These devices can be employed as implantable electronic circuits or new approaches for energy-harvesting applications. Furthermore, the incorporation of functional organic molecules gives rise to novel devices with almost limitless chemical and biological functionalities.