Multi-Surface Adhesion Luminescent Solar Concentrators for Supply-Less IoT.

The growing prevalence of Internet of Things (IoT) devices hinges on resolving the challenge of powering sensors and transmitters. Addressing this, supply-less IoT devices are gaining traction by integrating energy harvesters. This study introduces a temperature sensor devoid of external power sources, achieved through a novel luminescent solar concentrator (LSC) device based on a stretchable, adhesive elastomer. Leveraging a lanthanide-doped styrene-ethylene-butylene-styrene matrix, the LSC yielded 0.09% device efficiency. The resultant temperature sensor exhibits a thermal sensitivity of 2.1%°C-1 and a 0.06 °C temperature uncertainty, autonomously transmitting real-time data to a server for user visualization via smartphones. Additionally, the integration of LED-based lighting enables functionality in low-light conditions, ensuring 24 h cycle operation and the possibility of having four distinct thermometric parameters without changing the device configuration, stating remarkable robustness and reliability of the system.

Strain measurement with multiplexed FBG sensor arrays: An experimental investigation.

In conventional rock mechanics testing, radial strain measuring devices are usually attached to the sample's surface at its mid-height. Although this procedure provides a realistic picture of the lateral deformation undergone by homogeneous samples, however, this assumption may not be accurate if the tested rock has significant heterogeneity. Fibre Bragg Grating (FBG) sensors have recently been introduced to various rock testing applications due to their versatility over conventional strain gauges and radial cantilevers. FBG sensors have small size, multiplexing capability, and immunity to magnetic interference. The main objective of this study is to explore and understand the capabilities of FBG sensing for strain measurement during rock mechanics testing, including under confining. To do so, two limestone plugs (Savonnières limestone) and one acrylic Poly Methyl Methacrylate (PMMA) plug, all of 38 mm diameter, were prepared. The acrylic plug and one of the Savonnières samples plugs were subjected to Unconfined Compressive Strength (UCS) tests. The second Savonnières plug was subjected to a hydrostatic test up to 20 MPa confining at room temperature. FBG sensors of 125 µm cladding diameter with ceramics (Ormocer) coating were glued on the surface of each sample, spreading across the entire sample's height. Strain gauges and cantilever-type radial gauges were used on the samples submitted to UCS for comparison. Results show that radial strain measurements and calculated elastic properties derived from the FBG readings for samples are comparable to readings from the conventional strain gauges and cantilever-type devices. Apparent bulk moduli based on volumetric strain computed from FBG radial strain readings during the hydrostatic test on the Savonnières sample was consistent with benchtop measurements conducted on the Savonnières sample and another plug extracted from the same parental block, as well as published literature data. Moreover, variations in the calculated elastic properties are interpreted as evidence that the FBG sensors detected heterogeneities in the samples' inner structure, which can be seen in the density profiles computed from x-ray CT images. Such observation confirms the potential of the presented FBG sensors configuration for 3D strain mapping in rock mechanics tests.

Label-free DNA detection using silver nanoprism decorated silicon nanoparticles: Effect of silicon nanoparticle size and doping levels.

In the present work, we have fabricated silver nanoprism (AgNPrs)/silicon nanoparticle (SiNPs) hybrid arrays for highly sensitive detection of biomolecules via surface-enhanced Raman spectroscopy (SERS) technique. SiNPs having 7 to 37 nm in size and with phosphorous doping varying from 1 × 1019 to 1 × 1020 cm-3 were synthesized in nonthermal plasma synthesis. SiNPs were further immobilized on glass substrates using spin-coating, followed by deposition of AgNPrs using the drop-casting method. SERS studies showed that AgNPrs/SiNPs hybrid arrays exhibit substantial amplification of fingerprint bands of rhodamine 6G (R6G) compared to bare silicon as the reference. Raman signal intensity was found to be dependent on the size of SiNPs, with the largest nanoparticles exhibiting the highest SERS enhancement. In addition, an increase in phosphorous doping concentration was found to reduce R6G peak intensities. AgNPrs/SiNPs hybrid arrays showed excellent stability over time and high spot-to-spot reproducibility as well. Moreover, hybrid arrays enabled DNA detection through intense vibrational modes of human genomic DNA, with a lower detection limit of 1.5 pg/µL; indicating that AgNPrs/SiNPs sensors can serve as a reliable and cost-effective biosensing platform for rapid and label-free analysis of biomolecules.

Postoperative aesthetic and healing features of postectomy using three different surgical techniques: a randomized, prospective, and interdisciplinary analysis.

OBJECTIVE: to compare the postoperative esthetic and healing aspects of postectomy performed by different surgical techniques, based on the evaluation of different specialty expert professionals. METHODS: prospective and randomized clinical trial enrolling 149 preschool children with a medical indication for circumcision, divided into three groups: postectomy with the hemostatic device Plastibell® (PB group), conventional technique (CV group) and conventional with subcuticular stitches (SC group). Pictures were taken from patients at pre-defined angles on the 30th and 60th postoperative days. Photos were evaluated by three specialists (dermatologist, pediatrician and plastic surgeon), who assigned scores from 1 to 5 regarding the esthetic and healing features at each moment. Grades 4 or 5 from all specialists characterized "best result". Data were analysed to compare the used surgical techniques, the judgments from specialties and postoperative complications. RESULTS: most of the patients obtained the "best result" regarding healing (70%) and esthetics (56%). The final overall result showed the PB group as the best for healing (p=0.028) and the SC group as the best for esthetics (p=0.002). For the dermatologist, on the 60th postoperative day, the CV group presented the worst aesthetic result, whereas for the pediatrician and the plastic surgeon, the PB group presented the best healing result and the SC group had the best esthetic result. There was no difference between the groups regarding the presence of complications. CONCLUSION: the most common surgical techniques used to perform postectomy in children were differently assessed regarding healing and esthetic features by distinct medical professionals. The analysis of these two parameters among experts from related areas diverged among them and over time.

Postoperative aesthetic and healing features of postectomy using three different surgical techniques: a randomized, prospective, and interdisciplinary analysis / Aspectos estético e cicatricial pós-operatórios da postectomia por três diferentes técnicas cirúrgicas: análise randomizada, prospectiva e interdisciplinar

ABSTRACT Objective: to compare the postoperative esthetic and healing aspects of postectomy performed by different surgical techniques, based on the evaluation of different specialty expert professionals. Methods: prospective and randomized clinical trial enrolling 149 preschool children with a medical indication for circumcision, divided into three groups: postectomy with the hemostatic device Plastibell® (PB group), conventional technique (CV group) and conventional with subcuticular stitches (SC group). Pictures were taken from patients at pre-defined angles on the 30th and 60th postoperative days. Photos were evaluated by three specialists (dermatologist, pediatrician and plastic surgeon), who assigned scores from 1 to 5 regarding the esthetic and healing features at each moment. Grades 4 or 5 from all specialists characterized "best result". Data were analysed to compare the used surgical techniques, the judgments from specialties and postoperative complications. Results: most of the patients obtained the "best result" regarding healing (70%) and esthetics (56%). The final overall result showed the PB group as the best for healing (p=0.028) and the SC group as the best for esthetics (p=0.002). For the dermatologist, on the 60th postoperative day, the CV group presented the worst aesthetic result, whereas for the pediatrician and the plastic surgeon, the PB group presented the best healing result and the SC group had the best esthetic result. There was no difference between the groups regarding the presence of complications. Conclusion: the most common surgical techniques used to perform postectomy in children were differently assessed regarding healing and esthetic features by distinct medical professionals. The analysis of these two parameters among experts from related areas diverged among them and over time.

RESUMO Objetivo: analisar os aspectos estético e cicatricial pós-operatórios (PO) de pacientes submetidos a postectomia por diferentes técnicas cirúrgicas a partir da avaliação de profissionais experientes de áreas afins. Método: ensaio clínico prospectivo e randomizado, incluindo 149 meninos em idade pré-escolar com indicação médica de postectomia, divididos em três grupos: postectomia com dispositivo hemostático Plastibell® (grupo PB), técnica convencional (grupo CV) e convencional com pontos subcuticulares (grupo SC). Os pacientes foram fotografados em ângulos predefinidos no 30º e 60º dias de PO e as fotos avaliadas por três especialistas (dermatologista, pediatra e cirurgião plástico) que atribuíram notas entre 1 e 5, quanto aos aspectos estético e cicatricial em cada momento. Notas 4 ou 5 de todos os especialistas caracterizaram o "melhor resultado". Os dados foram submetidos à análise estatística para comparar as técnicas cirúrgicas, as avaliações dos especialistas e as complicações pós-operatórias. Resultados: a maioria dos pacientes obteve "melhor resultado" cicatricial (70%) e estético (56%). O resultado geral final apontou o grupo PB como superior quanto à cicatrização (p=0,028) e o grupo SC quanto ao aspecto estético (p=0,002). Para o dermatologista, na segunda avaliação, o grupo CV apresentou o pior resultado estético, enquanto para o pediatra e o cirurgião plástico, o grupo PB apresentou o melhor resultado cicatricial e o grupo SC o melhor resultado estético. Não houve diferença entre os grupos quanto à presença de complicações. Conclusão: as técnicas cirúrgicas mais empregadas para realizar postectomia em crianças foram avaliadas quanto aos resultados cicatricial e estético de distintas maneiras. A análise desses dois parâmetros entre especialistas de áreas afins divergiu entre eles e ao longo do tempo.

Bladder Urothelial Carcinoma in a Child: Case Report and Review of Literature.

Bladder urothelial carcinoma (UC) it is the fifth most prevalent carcinoma in humans, nevertheless in children and young adults it's very rare. It usually occurs in older adults. Literature on UC in pediatric population is limited and important information (risk factors, follow-up protocols, etc.) are poorly defined. We present an 11-year-old boy with a painful macroscopic hematuria. Ultrasound revealed a heterogeneous intravesical mass without extravesical extension, which was confirmed by computed tomography (CT) and magnetic resonance imaging (MRI). The first biopsy was compatible with urothelial papilloma. After 1 year, he returned with a bigger mass. Transurethral resection of the bladder (TURB) was performed and immunohistochemistry showed low-grade papillary UC with a high-grade component, with tumor free margin. Tumor had mutations in the BRAF and KRAS genes. Two and a half years after the resection the patient has no recurrence. Less than 1% of bladder UC occur in the first two decades of life. Gross hematuria is a common symptom. Ultrasound is generally the first diagnostic tool. MRI is also helpful, but cystoscopy allows definitive diagnosis. Transurethral resection of the bladder (TURB) is the standard treatment, with good results and low recurrence rate, and it was the treatment of choice for our patient, that remains free of disease. The BRAF and KRAS gene mutations were never described before in pediatric UC. There are only few cases in literature of pediatric UC that present a tumor genetic profile; therefore, our case report adds more information to this very rare disease in children.

Behavioral and biochemical effects of the antifouler and antidandruff zinc pyrithione on the freshwater fish Gambusia holbrooki.

The presence of pharmaceutical residues in the aquatic environment is receiving great attention since the levels of these substances have significantly increased in this compartment, potentially leading to adverse ecological effects. Zinc pyrithione (ZnPt) is a widely used organometallic biocide, which is incorporated into antifouling formulas, such as paints, to prevent the establishment of biofilms on surfaces exposed to the aquatic environment. It is also used in cosmetics, such as antidandruff shampoos and soaps. Considering this wide use, and the absence of a significant amount of data on the toxicity of ZnPt especially towards non-target organisms, the objective of this study was to characterize the toxicity of ZnPt, on several ecological relevant endpoints assessed in the fish Gambusia holbrooki. For this purpose, we measured traits related to feeding and aggressive behavior, as well as indicators of oxidative stress (CAT and GSTs), neurotoxicity (AChE), and anaerobic metabolism (LDH), after acute and chronic exposures to ZnPt. In terms of behavioral features, the feeding test showed the occurrence of significant differences between the control animals and those exposed to a concentration of ZnPt of 45 µg/L. In addition, ZnPt caused changes in terms of oxidative stress biomarkers (CAT and GSTs), for both exposure periods. ZnPt was also capable of causing changes in the cholinergic neurotransmission functioning and anaerobic metabolism, but only following the chronic exposure.

Intra- and inter-nanocrystal charge transport in nanocrystal films.

The exploitation of semiconductor nanocrystal (NC) films in novel electronic and optoelectronic applications requires a better understanding of charge transport in these systems. Here, we develop a model of charge transport in NC films, based on a generalization of the concept of transport energy level ET to nanocrystal assemblies, which considers both intra- and inter-NC charge transfer processes. We conclude that the role played by each of these processes can be probed from temperature-dependent measurements of charge carrier density n and mobility µ in the same films. The model also enables the determination of the position of the Fermi energy level EF with respect to ET, an important parameter of charge transport in semiconductor materials, from the temperature dependence of n. Moreover, we provide support to an essentially temperature-independent intra-NC charge carrier mobility, considered in the transport level concept, and consequently the frequently observed temperature dependence of the overall mobility µ in NC films results from a temperature variation of the inter-NC charge transport processes. Importantly, we also conclude that the temperature dependence of conductivity in NC films should result in general from a combination of temperature variations of both n and µ. By applying the model to solution-processed Si NC films, we conclude that transport within each NC is similar to that in amorphous Si (a-Si), with charges hopping along band tail states located below the conduction band edge. For Si NCs, we obtain values of ET - EF of ∼0.25 eV. The overall mobility µ in Si NC films is significantly further reduced with respect to that typically found in a-Si due to the additional transport constraints imposed by inter-NC transfer processes inherent to a nanoparticulate film. Our model accounting for inter- and intra-NC charge transport processes provides a simple and more general description of charge transport that can be broadly applied to films of semiconductor NCs.

Substrate and Mg doping effects in GaAs nanowires.

Mg doping of GaAs nanowires has been established as a viable alternative to Be doping in order to achieve p-type electrical conductivity. Although reports on the optical properties are available, few reports exist about the physical properties of intermediate-to-high Mg doping in GaAs nanowires grown by molecular beam epitaxy (MBE) on GaAs(111)B and Si(111) substrates. In this work, we address this topic and present further understanding on the fundamental aspects. As the Mg doping was increased, structural and optical investigations revealed: i) a lower influence of the polytypic nature of the GaAs nanowires on their electronic structure; ii) a considerable reduction of the density of vertical nanowires, which is almost null for growth on Si(111); iii) the occurrence of a higher WZ phase fraction, in particular for growth on Si(111); iv) an increase of the activation energy to release the less bound carrier in the radiative state from nanowires grown on GaAs(111)B; and v) a higher influence of defects on the activation of nonradiative de-excitation channels in the case of nanowires only grown on Si(111). Back-gate field effect transistors were fabricated with individual nanowires and the p-type electrical conductivity was measured with free hole concentration ranging from 2.7 × 1016 cm-3 to 1.4 × 1017 cm-3. The estimated electrical mobility was in the range ≈0.3-39 cm2/Vs and the dominant scattering mechanism is ascribed to the WZ/ZB interfaces. Electrical and optical measurements showed a lower influence of the polytypic structure of the nanowires on their electronic structure. The involvement of Mg in one of the radiative transitions observed for growth on the Si(111) substrate is suggested.

Management of traumatic urethral injuries in children using different techniques: A case series and review of literature.

INTRODUCTION: Most pediatric urethral injuries are a result of pelvic fracture after high-impact blunt trauma, mainly due to motor vehicle accidents. The management of urethral injuries depends on if the rupture is complete or partial as well as the timing of surgical intervention. PRESENTATION OF CASES: Three male children with urethral trauma caused by motor vehicles accidents are presented in this article. Preoperative suprapubic catheterization was initially carried out in all patients. Each patient then received one of three different techniques during the deferred time to surgical intervention: anterior sagittal transanorectal approach (ASTRA) for end-to-end urethral anastomosis, perineal approach for urethroplasty using buccal mucosa, and urethroplasty with preputial skin flap. The three techniques were successfully performed. DISCUSSION: In the initial management suprapubic cystostomy has been a good solution in urgent situations. Deferred urethroplasty is the procedure of choice for the definite treatment of posterior urethral distraction defects. The anterior sagittal transanorectal approach provides excellent exposure of the posterior urethra and retrovesicular region, and allows the surgeon to perform dissection under direct vision. CONCLUSION: It's very important for the pediatric urologist to be familiar with the different techniques available in order to choose the best approach for each particular patient.