Enhanced Elastocaloric Effects in γ-Graphyne.

The global emphasis on sustainable technologies has become a paramount concern for nations worldwide. Specifically, numerous sustainable methods are being explored as promising alternatives to the well-established vapor-compression technologies in cooling and heating devices. One such avenue gaining traction within the scientific community is the elastocaloric (eC) effect. This phenomenon holds promise for efficient cooling and heating processes without causing environmental harm. Studies carried out at the nanoscale have demonstrated the efficiency of the eC effect, proving to be comparable to that of state-of-the-art macroscopic systems. In this study, we used classical molecular dynamics simulations to investigate the elastocaloric effect for the recently synthesized γ-graphyne. Our analysis goes beyond obtaining changes in eC temperature and the coefficient of performance (COP) for two species of γ-graphyne nanoribbons (armchair and zigzag). We also explore their dependence on various conditions, including whether they are deposited on a substrate or prestrained. Our findings reveal a substantial enhancement in the elastocaloric effect for γ-graphyne nanoribbons when subjected to prestrain, amplifying it by at least 1 order of magnitude. Under certain conditions, the changes in the eC temperature and the COP of the structures reach expressive values as high as 224 K and 14, respectively. We discuss the implications of these results by examining the shape and behavior of the carbon-carbon bond lengths within the structures.

Development of an image-based fluorometer with smartphone control for paper analytical devices.

This work describes the construction and evaluation of a fluorometer for use in paper analytical devices, using a smartphone to operate the instrument and to perform real-time image-based detection. In this approach, a circular PAD containing twenty analytical plates is rotated at 18° increments under a UV LED source, providing a sequential irradiation of plates and the detection of the luminescence with a lab-made application, capable of automatically identifying the analytical zones and collecting the RGB intensities from the selected pixels. As a proof of concept, the fluorometer performance was evaluated for the determination of quinine in beverages and riboflavin (B2 vitamin) in supplements. Quinine, which is less photoreactive, provided steady-state signals, while riboflavin, which rapidly degrades under UV photons, presented transient responses for RGB detection. For both analytes, linear calibration ranges (R2 > 0.99) were observed from 2.0 mg L-1 to 10.0 mg L-1 with limits of detection estimated at approximately 1.0 mg L-1. Nevertheless, it was demonstrated that successive additions of standard solutions to a single analytical plate of PAD could enhance the signal-to-noise ratios for less concentrated samples, acting as a pre-concentration step. In addition, suitable deviations for the signals (ca. 4.0%) and the absence of systematic errors for most samples (9 out of 11), when compared with a reference method at 95% confidence level, indicates that the proposed strategy is precise and accurate enough to be used as analytical tool for fluorescence detection in PAD.

Elastocaloric Effect in Graphene Kirigami.

Kirigami, a traditional Japanese art of paper cutting, has recently been explored for its elastocaloric effect (ECE) in kirigami-based materials (KMs), where an applied strain induces temperature changes. Importantly, the feasibility of a nanoscale graphene kirigami monolayer was experimentally demonstrated. Here, we investigate the ECE in GK representing the thinnest possible KM to better understand this phenomenon. Through molecular dynamics simulations, we analyze the temperature change and coefficient of performance (COP) of GK. Our findings reveal that while GKs lack the intricate temperature changes observed in macroscopic KMs, they exhibit a substantial temperature change of approximately 9.32 K (23 times higher than that of macroscopic KMs, which is about 0.4 K) for heating and -3.50 K for cooling. Furthermore, they demonstrate reasonable COP values of approximately 1.57 and 0.62, respectively. It is noteworthy that the one-atom-thick graphene configuration prevents the occurrence of the complex temperature distribution observed in macroscopic KMs.

Purple passion fruit (Passiflora edulis f. edulis): A comprehensive review on the nutritional value, phytochemical profile and associated health effects.

Passiflora is a highly diverse genus where taxonomic lack of consensus remains. This may be the reason why numerous studies do not specify to the infraspecific level the plant material used or lack consistency in the nomenclature of botanical formae of Passiflora edulis. Ultimately, this may contribute to inaccurate chemical composition and health effects attributed to different Passiflora edulis species and formae. Hence, this review aims to overcome these challenges by exploring the phytochemical profile, specific nutritional value and potential health benefits of purple passion fruit (PPF). PPF is often consumed fresh for its pulp (including seeds) or juice, either directly or added to food dishes. It is also used industrially to produce a wide range of products, where peels and seeds are abundant by-products, most often discarded or used in low-value applications. Herein, in a perspective of integral valorisation of the fruit, the potential use of all PPF fractions (peel, pulp and seeds) is discussed as a source of important macro and micronutrients, adequate to integrate a balanced and healthy diet. In addition, the phytochemical profile of such fractions is also discussed along with the associated in vitro biological activities (antioxidant, anti-inflammatory, antibacterial and antifungal) and in vivo beneficial effects in the management of several diseases (asthma, hypertension, osteoarthritis, diabetes and pulmonary fibrosis). In summary, this review gathers the current knowledge on the nutritional and phytochemical composition of PPF and highlights the potential of using all fractions as a source of ingredients in food formulations that promote health and well-being. At the same time, it also contributes to defining sustainable strategies for an integrated valorisation of this natural product.

Scalable Synthesis and Characterization of Multilayer γ-Graphyne, New Carbon Crystals with a Small Direct Band Gap.

γ-Graphyne is the most symmetric sp2/sp1 allotrope of carbon, which can be viewed as graphene uniformly expanded through the insertion of two-carbon acetylenic units between all the aromatic rings. To date, synthesis of bulk γ-graphyne has remained a challenge. We here report the synthesis of multilayer γ-graphyne through crystallization-assisted irreversible cross-coupling polymerization. A comprehensive characterization of this new carbon phase is described, including synchrotron powder X-ray diffraction, electron diffraction, lateral force microscopy, Raman spectroscopy, infrared spectroscopy, and cyclic voltammetry. Experiments indicate that γ-graphyne is a 0.48 eV band gap semiconductor, with a hexagonal a-axis spacing of 6.88 Å and an interlayer spacing of 3.48 Å, which is consistent with theoretical predictions. The observed crystal structure has an aperiodic sheet stacking. The material is thermally stable up to 240 °C but undergoes transformation at higher temperatures. While conventional 2D polymerization and reticular chemistry rely on error correction through reversibility, we demonstrate that a periodic covalent lattice can be synthesized under purely kinetic control. The reported methodology is scalable and inspires extension to other allotropes of the graphyne family.

Abdominal esophagocardiectomy with esophagogastric anastomosis, with vagal preservation and construction of a spiral anti reflux valve in the treatment of advanced megaesophagus.

OBJECTIVE: present a new operative technique characterized by abdominal esophagocardiectomy, with esophagogastrus anastomosis, vagal preservation and spiral anti-reflux valve construction in the treatment of advanced megaesophagus in patients with severe systemic diseases, as well as its result in an initial group of 17 patients. METHOD: We selected 17 patients with advanced megaesophagus and comorbidities submitted to new technique. The following parameters were analyzed: age, sex, length of hospital stay, early and late complications, mortality, radiological/endoscopic aspects. RESULTS: twelve male patients (70%) and five (30%) were operated on, with mean age of 51.5 years and mean hospital stay of 14.8 days. There was no mortality in the immediate intraoperative or postoperative period and there were no cases of postoperative fistula. During hospitalization there was one case of pulmonary atelectasis (5.8%), one of pleural effusion (5.8%), two of wall infection (11.7%) and one of urinary retention (5.8%). Discussion: We believe it to be an easy technique, made exclusively by the abdominal route, that is, without violating the thoracic cavity. Such a procedure would be beneficial in patients with advanced megaesophagus and important comorbidities, as well as in those with a history of previous surgeries. CONCLUSION: the technique described was easy to perform and safe, when performed by an experienced team, with low morbidity and mortality in patients with advanced megaesophagus and important comorbidities, which could increase your complications with more invasive and complex surgeries.

Managing tube thoracostomy with thoracic ultrasound: results from a randomized pilot study.

PURPOSE: Tube thoracostomy (TT) is a simple and a life-saving procedure; nevertheless, it carries morbidity, even after its removal. Currently, TT is managed and removed by chest X-ray (CXR) evaluation. There are limitations and these are directly linked to complications. The use of thoracic ultrasound (US) has already been established in the diagnosis of pneumothorax (PTX) and hemothorax (HTX); its use, in substitution of CXR can lead to improvement in care. Our aim is to evaluate the efficiency and safety of US in the management of TT. METHODS: Prospective and randomized study with patients requiring TT. They were divided in groups according to their thoracic injuries (PTX and HTX) and randomized into two groups according to TT management: US and CXR. Data collected included gender, age, mechanism of injury, days to TT removal, complications after TT removal and presence of mechanical ventilation. RESULTS: Sixty-one patients were randomized, of which 68.8% were male. The most frequent diagnosis was PTX, present in 37 cases. Median time for TT removal was 2.5 days in the US group and 4.9 in the control group (p = 0.009). The complication rate was 6.6%, with no morbidity in the US group. TT removal in patients with mechanical ventilation did not increase the incidence of complications. CONCLUSIONS: The use of US in the management is efficient and safe. It allows early TT removal regardless the cause of the thoracic injury.

Abdominal esophagocardiectomy with esophagogastric anastomosis, with vagal preservation and construction of a spiral anti reflux valve in the treatment of advanced megaesophagus / Esofagocardiectomia abdominal com esofagogastro anastomose, com preservação vagal e construção de válvula antirrefluxo em espiral no tratamento do megaesôfago avançado

ABSTRACT Objective: present a new operative technique characterized by abdominal esophagocardiectomy, with esophagogastrus anastomosis, vagal preservation and spiral anti-reflux valve construction in the treatment of advanced megaesophagus in patients with severe systemic diseases, as well as its result in an initial group of 17 patients. Method: We selected 17 patients with advanced megaesophagus and comorbidities submitted to new technique. The following parameters were analyzed: age, sex, length of hospital stay, early and late complications, mortality, radiological/endoscopic aspects. Results: twelve male patients (70%) and five (30%) were operated on, with mean age of 51.5 years and mean hospital stay of 14.8 days. There was no mortality in the immediate intraoperative or postoperative period and there were no cases of postoperative fistula. During hospitalization there was one case of pulmonary atelectasis (5.8%), one of pleural effusion (5.8%), two of wall infection (11.7%) and one of urinary retention (5.8%). Discussion: We believe it to be an easy technique, made exclusively by the abdominal route, that is, without violating the thoracic cavity. Such a procedure would be beneficial in patients with advanced megaesophagus and important comorbidities, as well as in those with a history of previous surgeries. Conclusion: the technique described was easy to perform and safe, when performed by an experienced team, with low morbidity and mortality in patients with advanced megaesophagus and important comorbidities, which could increase your complications with more invasive and complex surgeries.

RESUMO Objetivo: apresentar uma nova técnica caracterizada por esofagocardiectomia abdominal com esofagogastro anastomose, preservação vagal e construção de válvula antirrefluxo em espiral no tratamento do megaesôfago avançado de pacientes com doenças sistêmicas graves, assim como seu resultado em grupo inicial de 17 pacientes. Método: foram selecionados 17 pacientes com megaesôfago avançado e comorbidades submetidos a nova técnica. Os seguintes parâmetros analisados foram: idade, sexo, tempo de permanência hospitalar, complicações precoces e tardias, mortalidade, aspectos radiológicos/endoscópicos. Resultados: foram operados 12 (70%) pacientes do sexo masculino e 5 (30%) do sexo feminino, com idade média foi de 51,5 anos e tempo de permanência hospitalar médio de 14,8 dias. Não houve mortalidade no intraoperatório ou pós-operatório imediato e não houve casos de fìstula. Durante a internação houve um caso de atelectasia pulmonar (5,8%), um de derrame pleural (5,8%), dois de infecção de parede (11,7%) e um de retenção urinária (5,8%). Discussão: acreditamos ser uma técnica de fácil realização, feita exclusivamente por via abdominal, ou seja, sem violar a cavidade torácica. Tal procedimento seria benéfico em pacientes com megaesôfago avançado e comorbidades importantes, assim como naqueles com história de cirurgias prévias. Conclusão: a técnica descrita mostrou-se de fácil execução e segura, quando realizada por equipe experiente, com baixa morbimortalidade em pacientes com megaesôfago avançado e comorbidades importantes, o que poderia aumentar suas complicações com cirurgias mais invasivas e complexas.

A new quantitative gel electrophoresis method with image-based detection for the determination of food dyes and metallic ions.

This work describes an alternative application of gel electrophoresis for the separation and quantification of analytes with low molecular weights using an innovative and low-cost apparatus that enables the acquisition of image-based electropherograms with a webcam. As a proof of concept, the determination of Cu and Ni content in metallic alloys was evaluated by means of the separation and detection of the metallic ions, previously complexed with Eriochrome Black T. Furthermore, the determination of the food colouring agents Sunset Yellow FCF, Tartrazine, Brilliant Blue FCF and Amaranth Red in powder refreshment samples was investigated as alternative to well-stablished methods used for this purpose. For all investigated analytes, the corresponding electrophoretic peaks showed signal to noise ratios ranging from 10 to 180, suitable precision on areas (RSD < 3.5%) and linear relationships (R > 0.99) between RGB detected signals and concentrations of the standard solutions. Application of the method to the determination of Cu and Ni contents in metallic alloys provided results with no significant differences, at 95% confidence level, when compared to the results obtained with a FAAS based method. Apparent recoveries estimated for powder refreshment samples fortified with the food dyes ranged from 93% to 108% for added and found contents, suggesting the absence of matrix effects. The studies prove the feasibility of separation and quantification of coloured analytes by gel electrophoresis and image-based detection that can be useful for different samples.

Laparoscopic resection of primary retroperitoneal schwannoma: A case report.

BACKGROUND: Schwannomas are rare, often benign, tumors deriving from Schwann cells that have low incidence in the retroperitoneal region (0.5% to 5%). Their diagnosis is hardly confirmed at early stage due to lack of specific features in signs, symptoms and imaging tests. Thus, it is necessary performing guided punch biopsy in order to identify it. Tumor removal is the treatment of choice due to its low sensitivity to radiation and chemotherapy. CASE SUMMARY: Forty-seven years old female patient who was hospitalized for elective orthopedic procedure, without complications, evolved with severe pain in the lower limbs, thigh and gluteal region associated with neurogenic claudication. Persistent pain required magnetic resonance imaging (MRI) of the lumbar spine, which showed epidural collection with dural compression and massive heterogeneous perihepatic nodular lesion. The surgical team opted for draining the collection, as well as requested an MRI of the abdomen and pelvis, whose analysis showed expansive lesion in the retroperitoneum, in close contact with the inferior vena cava and with the right renal vein. A guided puncture was performed for diagnostic clarification, which showed immunohistochemical profile compatible with schwannoma. The selected treatment comprised retroperitoneum tumor resection in association with laparoscopic cholecystectomy. The patient was discharged and remained stable after 4-mo follow-up; she remains under follow-up to check the need of cancer investigations. CONCLUSION: Schwannoma features requires surgical treatment based on laparoscopic resection, which often presents low relapse rates and optimistic prognosis.