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Nano Letters Jul 2024The controlled vapor-phase synthesis of two-dimensional (2D) transition metal dichalcogenides (TMDs) is essential for functional applications. While chemical vapor...
The controlled vapor-phase synthesis of two-dimensional (2D) transition metal dichalcogenides (TMDs) is essential for functional applications. While chemical vapor deposition (CVD) techniques have been successful for transition metal sulfides, extending these methods to selenides and tellurides often faces challenges due to uncertain roles of hydrogen (H) in their synthesis. Using CVD growth of MoSe as an example, this study illustrates the role of a H-free environment during temperature ramping in suppressing the reduction of MoO, which promotes effective vaporization and selenization of the Mo precursor to form MoSe monolayers with excellent crystal quality. As-synthesized MoSe monolayer-based field-effect transistors show excellent carrier mobility of up to 20.9 cm/(V·s) with an on-off ratio of 7 × 10. This approach can be extended to other TMDs, such as WSe, MoTe, and MoSe/WSe in-plane heterostructures. Our work provides a rational and facile approach to reproducibly synthesize high-quality TMD monolayers, facilitating their translation from laboratory to manufacturing.
PubMed: 38949123
DOI: 10.1021/acs.nanolett.4c01314 -
Advanced Healthcare Materials Jun 2024Osteochondral regeneration remains formidable challenges despite significant advances in microsurgery. Herein, an acellular trilayer cryogel (TC) with injectability,...
Osteochondral regeneration remains formidable challenges despite significant advances in microsurgery. Herein, an acellular trilayer cryogel (TC) with injectability, tunable pore sizes (80-200 µm), and appropriate compressive modulus (10.8 kPa) is manufactured from self-healable hydrogel under different gelling times through Schiff reaction between chitosan and difunctionalized polyurethane (DFPU). Bioactive molecules (Y27632 and dexamethasone) are respectively loaded in the top and bottom layers to form the Y27632/dexamethasone-loaded trilayer cryogel (Y/DEX-TC). Mesenchymal stem cells (MSCs) seeded in Y/DEX-TC proliferated ≈350% in vitro and underwent chondrogenesis or osteogenesis in response to the respective release of Y or DEX in 14 days. Acupuncture is administered to animals in an attempt to modulate the innate regulatory system and mobilize endogenous MSCs for osteochondral defect regeneration. In vivo rabbit experiments using Y/DEX-TC combined with acupuncture successfully regulate SDF-1 and TGF-β1 levels, which possibly cause MSC migration toward Y/DEX-TC. The synergistic effect of cryogel and acupuncture on immunomodulation is verified with a ≈7.3-fold enhancement of the M2-/M1-macrophage population ratio by treatment of Y/DEX-TC combining acupuncture, significantly greater than ≈1.5-fold increase by acupuncture or ≈2.2-fold increase by Y/DEX-TC alone. This novel strategy using acellular drug-loaded cryogel and accessible acupuncture shows promise in treating osteochondral defects of joint damage.
PubMed: 38948966
DOI: 10.1002/adhm.202400462 -
Cureus May 2024Both public and academic scrutiny of the financial relationships between the medical device industry and the healthcare society occur less frequently than those...
Both public and academic scrutiny of the financial relationships between the medical device industry and the healthcare society occur less frequently than those involving the pharmaceutical industry, and Japan is no exception to these shortcomings. This paper examines the ethical and legal challenges inherent in Japan's medical device industry through the lens of bribery scandals, placing these issues within the broader context of global healthcare corruption. It aims to derive lessons and suggest universal strategies for ethical and legal enhancements. The discussion includes two notable cases: one involving inappropriate transactions between a cancer center and a biliary stent manufacturer, and another concerning a corrupt donation scheme between a medical device company and a university's anesthesiology department, which was found guilty. In our analysis, we also acknowledge the industry's efforts toward compliance and reform to maintain a balanced perspective. The analysis not only highlights the unique culture and structure of the Japanese medical device industry, such as the exploitation of flexible pricing and opaque financial practices but also contrasts these issues with the tightly regulated pharmaceutical industry. This approach reveals both sector-specific challenges and common corruption drivers, enhancing our understanding of why such scandals occur and persist. We propose ethical and compliance-focused business measures such as centralizing donation decisions, limiting the financial independence of marketing divisions, and increasing transparency, alongside adopting mandatory disclosure practices based on successful models from the United States and Europe. By emphasizing integrity and presenting diverse perspectives, this study aims to elevate ethical and legal standards in the medical device industry and improve patient health outcomes worldwide.
PubMed: 38947609
DOI: 10.7759/cureus.61285 -
Heliyon Jun 2024In this work, three different twist angles of a micro helical insert in a T-shaped are studied numerically in order to evaluate the laminar steady flow behavior of...
In this work, three different twist angles of a micro helical insert in a T-shaped are studied numerically in order to evaluate the laminar steady flow behavior of Newtonian fluid in chaotic geometry. In the geometries under consideration, thermal mixing behavior is carried out using fluids having two distinct input temperatures. Under the influence of chaotic advection and low rates of Reynolds number, the second law of thermodynamics is controlled in terms of the entropy generation caused by hydrodynamic and thermal processes. The governing equations are numerically solved using the CFD Fluent code. Thus, the micromixer's configuration demonstrated a very significant improvement in mixing degree while minimizing friction and thermal irreversibilities. The synergy coefficient, which depicts the link between velocity and heat transfer in angle form, is analyzed and the results are provided.
PubMed: 38947451
DOI: 10.1016/j.heliyon.2024.e32233 -
Analytical Methods : Advancing Methods... Jul 2024High-frequency pulse lasers, applied in the form of rapid scanning, act upon the surface of aircraft skin paint layers, thereby removing the paint layers, exhibiting...
High-frequency pulse lasers, applied in the form of rapid scanning, act upon the surface of aircraft skin paint layers, thereby removing the paint layers, exhibiting characteristics of efficiency and eco-friendliness. Real-time monitoring of the paint removal effect and prevention of substrate damage necessitates the continuous monitoring of paint removal thickness. Combining Laser-Induced Breakdown Spectroscopy (LIBS) online monitoring technology enables laser-controlled paint removal under multiple effects coupling, meeting the requirements of airworthiness maintenance. This paper, based on a high-frequency nanosecond infrared pulse laser paint removal LIBS monitoring platform, conducts research on laser paint removal thickness LIBS online monitoring of aluminum alloy plates coated with dual-layer paint. Spectra corresponding to the removal thickness of each group are collected and, respectively, paint removal thickness monitoring models based on LIBS spectra are established using the standard curve method and Principal Component Analysis-Support Vector Regression (PCA-SVR) algorithm. When monitoring paint removal thickness using the standard curve method, the intensity of five Ti element characteristic spectral lines selected is correlated with the paint removal thickness, and segmented curve fitting according to the paint layer structure satisfies the segmented curve fitting of topcoat and topcoat + primer. Among them, the average coefficient of the curve fitting of the Ti II 589.088 nm characteristic spectral line is 0.89, and the root mean square error (RMSE) is 12.28 μm. Its performance is superior in the five standard curves; thus, its fitting equation is used as the criterion for paint removal thickness monitoring. To further improve monitoring accuracy, research on paint removal thickness monitoring models based on PCA-SVR is conducted. Compared to the traditional univariate standard curve method, the PCA-SVR model does not require segmented monitoring. After parameter optimization, the average fitting coefficient reaches 0.97, and the RMSE is 2.92 μm. The results indicate that the PCA-SVR-based paint removal thickness monitoring model has higher accuracy, thereby forming the basis for paint removal thickness monitoring. Through comparative research on paint removal thickness monitoring models, two types of paint removal thickness monitoring criteria are obtained, providing model solutions for high-precision monitoring and automation of aircraft skin laser paint removal thickness.
PubMed: 38946640
DOI: 10.1039/d4ay00872c -
Chemistry (Weinheim An Der Bergstrasse,... Jul 2024How to coordinate electron and ion transport behavior across scales and interfaces within ion battery electrodes? The exponential increase in surface area observed in...
How to coordinate electron and ion transport behavior across scales and interfaces within ion battery electrodes? The exponential increase in surface area observed in nanoscale electrode materials results in an incomprehensibly vast spatial interval. Herein, to address the problems of volume expansion, dissolution of cathode material, and the charge accumulation problem existing in manganiferous materials for zinc ion batteries, metal organic framework is utilized to form the architecture of non-interfacial blocking ~10 nm Mn2O3 nanoparticles and amorphous carbon hybrid electrode materials, demonstrating a high specific capacity of 361 mAh g-1 (0.1 A g-1), and excellent cycle stability of 105 mAh g-1 after 2000 cycles under 1 A g-1. The uniform and non-separated disposition of Mn and C atoms constitutes an interconnected network with high electronic and ionic conductivity, minimizing issues like structural collapse and volume expansion of the electrode material during cycling. The cooperative insert mechanism of H+ and Zn2+ are analyzed via ex-situ XRD and in-situ Raman tests. The model battery is assembled to present practical possibilities. The results indicate that MOF-derived carbonization provides an effective strategy for exploring Mn-based electrode materials with high ion and electron transport capacity.
PubMed: 38946439
DOI: 10.1002/chem.202401802 -
Acta Dermatovenerologica Croatica : ADC Mar 2024Mutation of the BRAF oncogene is one of the most common mutations detected in human neoplasia, occurring in 40-60% of all cutaneous melanoma. BRAF is a serine/threonine...
Mutation of the BRAF oncogene is one of the most common mutations detected in human neoplasia, occurring in 40-60% of all cutaneous melanoma. BRAF is a serine/threonine protein kinase which is an essential part of the mitogen-activated protein kinase (MAPK) pathway. It is physiologically activated by RAS, but in mutated form, due to molecular conformational change, BRAF becomes constitutively active with subsequent persistent activation of downstream cytoplasmic and nuclear proteins (MEK, ERK, ETS), which finally leads to gene expression that promotes cell growth and survival. Inhibition of the altered MAPK pathway by BRAF inhibitors and combined BRAF/MEK inhibitors in BRAF mutated melanoma has become a standard therapeutic approach (1,2). We recently reported the frequency and clinicopathological features of BRAF V600E mutated melanomas in the Dalmatian region of Croatia. This report included 80 cutaneous melanomas with BRAF analyses performed at our institution until the second half of 2017, using a kit which detected only BRAF V600E mutation (3). From the second half of 2017, we started using a kit which detects several types of BRAF mutations along with NRAS mutation. The aim of this report was to determine the spectrum and frequency of different BRAF mutations in a group of skin melanomas in the Dalmatian region of Croatia and to comment on the relationship between type of BRAF mutation and therapeutic response to MAPK pathway inhibition. The analysis included 179 patients with stage 3 and stage 4 cutaneous melanoma with known BRAF/NRAS mutational status. The paraffin blocks were forwarded from four Dalmatian hospitals (Split: 139 cases, Zadar: 17 cases, Šibenik: 13 cases, Dubrovnik: 10 cases). BRAF/NRAS mutation analysis was performed at the Institute of Pathology, Clinical Hospital Center Split, Croatia, in the period from the second half of 2017 to the end of 2022. For DNA extraction analysis, hematoxylin and eosin stained slides from each submitted sample were reviewed by a pathologist, and tumor tissue was identified for analysis. For all tissue specimens, DNA was extracted from sections (10 mm thick) using the cobas® DNA Sample Preparation Kit (Roche Molecular Diagnostics), following the manufacturer's protocol. The amount of genomic DNA was quantified using the Qubit® 2.0 Fluorometer (Life Technologies) and adjusted to a fixed concentration to be added to the amplification/detection mixture. For mutation analysis, the target DNA was amplified and detected on the cobas z 480 analyzer using the amplification and detection reagents provided in the Roche BRAF/NRAS mutation test (LSR) kit, according to the manufacturer's protocol. The test results were reported as follows: BRAF exon 11 mutation detected, BRAF V600E/E2/D mutation detected, BRAF V600K mutation detected, BRAF V600R mutation detected, BRAF K601E mutation detected, NRAS (G12X, G13X, A18T, Q61X, other NRAS Ex3/4) mutation detected, mutation not detected, or invalid result (no result was obtained on the cobas test). BRAF mutation was observed in 87 patients (48.6%), NRAS mutation was found in 27 patients (15.1%), while 65 patients (36.3%) were without BRAF/NRAS mutation (Table 1). In the group of BRAF mutated melanomas, 61 cases (70.1%) had V600E/E2/D mutation, 20 cases (23%) had V600K mutation, 3 cases (3.4%) had exon 11 mutation, 2 cases (2.3%) had V600R mutation, and 1 case (1.2%) had K601E mutation (Table 2). The observed frequency of BRAF mutated melanomas in this study was similar to the frequency reported in our previous study (48.6% and 47.5%, respectively) (3). The vast majority were BRAF V600 mutations, while BRAF non-V600 mutations were rare (95.4% and 4.6%, respectively). In the group of BRAF V600 mutations, V600E/E2/D mutations predominated, followed by V600K mutations, while V600R mutations were rare. Greaves et al. reported similar frequency of BRAF V600 mutations in a group of 499 BRAF-mutated cutaneous melanomas, with V600E/E2/D mutations observed in 77.2% cases, followed by V600K mutations observed in 17.2% cases, and V600R mutations observed in 2.6% cases (4). BRAF non-V600 mutations (exon 11 and K601E mutations) were rarely observed in this study, confirming the findings of other authors (4,5). A three-class system of BRAF mutations was recently proposed that takes into account the differences in their kinase activity, with class I containing mutants with high kinase activity and high response rate to BRAF and BRAF/MEK inhibitors. Class II BRAF mutations have lower kinase activity than class I mutants, but higher than wild-type BRAF, showing resistance to BRAF inhibitor monotherapy and sensitivity to MEK and BRAF/MEK inhibitors. Finally, class III BRAF mutations are characterized by low kinase activity and low response rate to targeted therapy (6). BRAF V600 mutations belong to class I mutations, which means that the large majority of BRAF-positive melanomas in this study (95.4%) were sensitive to targeted therapy. However, the sensitivity to targeted therapy is different among different class I BRAF mutations. While large randomized controlled trials on combined BRAF/MEK inhibition showed good overall response (63-68%) and improvement of progression-free survival (PFS) and overall survival (OS) for the melanomas with most prevalent V600E and V600K mutations, Menzer et al. showed lower response rate to MAPK pathway inhibition (45%) in the group of metastatic melanomas with BRAF V600 mutations other than V600E/K. The overall response rate to MAPK pathway inhibition in the same group of melanomas with BRAF non-V600 mutations (class II and III mutations) was only 18% (7). In our group of BRAF mutated skin metastatic melanomas, we found only 6 cases (6.9%) with expected lower response rate to MAPK pathway inhibition: 2 cases with V600R mutation (class I non-V600E/K mutation), 1 case with K601E mutation (class II mutation), and 3 cases with exon 11 mutation (class II and III mutations).
Topics: Humans; Proto-Oncogene Proteins B-raf; Melanoma; Skin Neoplasms; Croatia; Mutation; Female; Male; Middle Aged; Aged; Adult; Aged, 80 and over
PubMed: 38946192
DOI: No ID Found -
Food Research International (Ottawa,... Aug 2024The effect of 90, 180 and 270 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), trisodium citrate (TSC) and sodium hexametaphosphate (SHMP) on the...
The effect of 90, 180 and 270 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), trisodium citrate (TSC) and sodium hexametaphosphate (SHMP) on the solubilisation of proteins and minerals and the rheological and textural properties of processed cheese (PC) prepared from Gouda cheese ripened for 30-150 d at 8°C was studied. The solubilisation of individual caseins and Ca and the maximum loss tangent during temperature sweeps of PC made from Gouda cheese increased, while hardness of PC decreased with ripening duration of the Gouda cheese. Levels of soluble Ca in PC increased with increasing concentration of TSC and SHMP, but decreased with increasing concentration of DSP. The solubilisation of casein and Ca due to ripening of Gouda cheese used for manufacturing PC could explain the changes in texture and loss tangent of PC. The results suggest that DSP, TSC or SHMP in PC formulation can form insoluble Ca-phosphate, soluble Ca-citrate or insoluble casein-Ca-HMP complexes, respectively, that influence casein solubilisation differently and together with levels of residual intact casein determine the functional attributes of PC.
Topics: Cheese; Food Handling; Caseins; Solubility; Rheology; Citrates; Calcium; Phosphates; Hardness; Time Factors; Calcium Phosphates
PubMed: 38945567
DOI: 10.1016/j.foodres.2024.114587 -
Neural Networks : the Official Journal... Jun 2024Brain-computer interfaces (BCIs), representing a transformative form of human-computer interaction, empower users to interact directly with external environments through...
Brain-computer interfaces (BCIs), representing a transformative form of human-computer interaction, empower users to interact directly with external environments through brain signals. In response to the demands for high accuracy, robustness, and end-to-end capabilities within BCIs based on motor imagery (MI), this paper introduces STaRNet, a novel model that integrates multi-scale spatio-temporal convolutional neural networks (CNNs) with Riemannian geometry. Initially, STaRNet integrates a multi-scale spatio-temporal feature extraction module that captures both global and local features, facilitating the construction of Riemannian manifolds from these comprehensive spatio-temporal features. Subsequently, a matrix logarithm operation transforms the manifold-based features into the tangent space, followed by a dense layer for classification. Without preprocessing, STaRNet surpasses state-of-the-art (SOTA) models by achieving an average decoding accuracy of 83.29% and a kappa value of 0.777 on the BCI Competition IV 2a dataset, and 95.45% accuracy with a kappa value of 0.939 on the High Gamma Dataset. Additionally, a comparative analysis between STaRNet and several SOTA models, focusing on the most challenging subjects from both datasets, highlights exceptional robustness of STaRNet. Finally, the visualizations of learned frequency bands demonstrate that temporal convolutions have learned MI-related frequency bands, and the t-SNE analyses of features across multiple layers of STaRNet exhibit strong feature extraction capabilities. We believe that the accurate, robust, and end-to-end capabilities of the STaRNet will facilitate the advancement of BCIs.
PubMed: 38945115
DOI: 10.1016/j.neunet.2024.106471 -
Nature Communications Jun 2024Compounding functional nanoparticles with highly conductive and porous carbon scaffolds is a basic pathway for engineering many important functional devices. However,...
Compounding functional nanoparticles with highly conductive and porous carbon scaffolds is a basic pathway for engineering many important functional devices. However, enabling uniform spatial distribution of functional particles within a massively conjugated, monolithic and mesoporous structure remains challenging, as the high processing temperature for graphitization can arouse nanoparticle ripening, agglomerations and compositional changes. Herein, we report a unique "popcorn-making-mimic" strategy for preparing a highly conjugated and uniformly compounded graphene@NiFeO composite film through a laser-assisted instantaneous compounding method in ambient condition. It can successfully inhibit the unwanted structural disintegration and mass loss during the laser treatment by avoiding oxidation, bursting, and inhomogeneous heat accumulations, thus achieving a highly integrated composite structure with superior electrical conductivity and high saturated magnetization. Such a single-sided film exhibits an absolute shielding effectiveness of up to 20906 dB cm g with 75% absorption rate, superior mechanical flexibility and excellent temperature/humidity aging reliability. These performance indexes signify a substantial advance in EMI absorption capability, fabrication universality, small form-factor and device reliability toward commercial applications. Our method provides a paradigm for fabricating sophisticated composite materials for versatile applications.
PubMed: 38942779
DOI: 10.1038/s41467-024-49498-1