Efficient and Stable Proton Exchange Membrane Water Electrolysis Enabled by Stress Optimization

Proton exchange membrane water electrolysis (PEMWE) is a promising solution for the conversion and storage of fluctuating renewable energy sources. Although tremendously efficient materials have been developed, commercial PEMWE products still cannot fulfill industrial demands regarding efficiency and stability. In this work, we demonstrate that the stress distribution, a purely mechanical parameter in electrolyzer assembly, plays a critical role in overall efficiency and stability. The conventional cell structure, which usually adopts a serpentine flow channel (S-FC) to deliver and distribute reactants and products, resulted in highly uneven stress distribution. Consequently, the anode catalyst layer (ACL) under the high stress region was severely deformed, whereas the low stress region was not as active due to poor electrical contact. To address these issues, we proposed a Ti mesh flow channel (TM-FC) with gradient pores to reduce the stress inhomogeneity. Consequently, the ACL with TM-FC exhibited 27 mV lower voltage initially and an 8-fold reduction in voltage degradation rate compared to that with S-FC at 2.0 A/cm2. Additionally, the applicability of the TM-FC was demonstrated in cross-scale electrolyzers up to 100 kW, showing a voltage increase of only 20 mV (accounting for less than 2% of overall voltage) after three orders of magnitude scaleup.

Effect of radiation cross-linked collagen scaffold in alveolar ridge preservation of extraction socket

This study aimed to evaluate the properties of radiation cross-linked collagen scaffold (RCS) and its efficacy for alveolar ridge preservation (ARP). RCS was prepared from collagen dispersion by electron beam irradiation and freeze-drying. The microstructure, swelling ratio, area alteration and mechanical properties of RCS were characterized. Fifty-four New Zealand rabbits performing incisor extraction on maxilla and mandible were randomly assigned into positive, sham operation or treatment groups. Micro-computed tomography (micro-CT) scans, performed after 1, 4, and 12 weeks of surgery, were to assess changes in ridge height at buccal and palatal side, in ridge width and in micromorphological parameters. Histological analysis accessed socket microarchitecture. The results showed that RCS had stable mechanical properties and morphologic features that provided a reliable physical support for ARP. Dimensional changes in treatment group revealed significantly greater vertical height at buccal (5.32 [3.37, 7.26] mm, p < .0001) and palatal (4.37 [2.66, 6.09] mm, p < .0001) side, and horizontal width at the maxilla (0.16 [0.04, 0.28] mm, p < .01) and mandible (0.33 [0.11, 0.54] mm, p < .01) than those in sham operation group after 12 weeks. The treatment group had advantage than positive group in vertical height preservation, quantitatively. The order and density of bone trabeculae were improved in treatment group. These findings indicated that RCS had the potential to serve as an effective scaffold for ARP.

A machine learning approach for predicting radiation-induced hypothyroidism in patients with nasopharyngeal carcinoma undergoing tomotherapy

The purpose of this study was to establish an integrated predictive model that combines clinical features, DVH, radiomics, and dosiomics features to predict RIHT in patients receiving tomotherapy for nasopharyngeal carcinoma. Data from 219 patients with nasopharyngeal carcinoma were randomly divided into a training cohort (n = 175) and a test cohort (n = 44) in an 8:2 ratio. RIHT is defined as serum thyroid-stimulating hormone (TSH) greater than 5.6 μU/mL, with or without a decrease in free thyroxine (FT4). Clinical features, 27 DVH features, 107 radiomics features and 107 dosiomics features were extracted for each case and included in the model construction. The least absolute shrinkage and selection operator (LASSO) regression method was used to select the most relevant features. The eXtreme Gradient Boosting (XGBoost) was then employed to train separate models using the selected features from clinical, DVH, radiomics and dosiomics data. Finally, a combined model incorporating all features was developed. The models were evaluated using receiver operating characteristic (ROC) curves and decision curve analysis. In the test cohort, the area under the receiver operating characteristic curve (AUC) for the clinical, DVH, radiomics, dosiomics and combined models were 0.798 (95% confidence interval [CI], 0.656-0.941), 0.673 (0.512-0.834), 0.714 (0.555-0.873), 0.698 (0.530-0.848) and 0.842 (0.724-0.960), respectively. The combined model exhibited higher AUC values compared to other models. The decision curve analysis demonstrated that the combined model had superior clinical utility within the threshold probability range of 1% to 79% when compared to the other models. This study has successfully developed a predictive model that combines multiple features. The performance of the combined model is superior to that of single-feature models, allowing for early prediction of RIHT in patients with nasopharyngeal carcinoma after tomotherapy.

A Highly Sensitive and Stretchable Core-Shell Fiber Sensor for Gesture Recognition and Surface Pressure Distribution Monitoring

This work reports a highly-strain flexible fiber sensor with a core-shell structure utilizes a unique swelling diffusion technique to infiltrate carbon nanotubes (CNTs) into the surface layer of Ecoflex fibers. Compared with traditional blended Ecoflex/CNTs fibers, this manufacturing process ensures that the sensor maintains the mechanical properties (923% strain) of the Ecoflex fiber while also improving sensitivity (gauge factor is up to 3716). By adjusting the penetration time during fabrication, the sensor can be customized for different uses. As an application demonstration, the fiber sensor is integrated into the glove to develop a wearable gesture language recognition system with high sensitivity and precision. Additionally, the authors successfully monitor the pressure distribution on the curved surface of a soccer ball by winding the fiber sensor along the ball's surface.

Recent Advance in Electrochromic Materials and Devices for Display Applications

Electrochromic devices (ECDs) possess the performance advantages in terms of color adjustability, low power consumption, and visual friendliness, emerging as one of the ideal candidates for energy-efficient smart windows, next-generation displays, and wearable electronics. The optical and electrical characteristics of ECDs can be adjusted by modifying the materials or structure of devices. This review summarizes the recent developments of innovative technologies and key materials of ECDs for display applications, highlighting the key issues and development trends in this area.

Comprehensive Effects of Potassium Lactate, Calcium Ascorbate and Magnesium Chloride as Alternative Salts on Physicochemical Properties, Sensory Characteristics and Volatile Compounds in Low-Sodium Marinated Beef

The search for alternative salt formulations similar to sodium chloride and their effect on marinated meat products is of great significance to the low-sodium meat processing industry. The main purpose of this study was to investigate the effect of partially replacing sodium chloride with potassium lactate, calcium ascorbate, and magnesium chloride on the sodium content, water activity and distribution, protein solubility, microstructure, sensory characteristics and volatile flavor compounds in low-sodium marinated beef. The sodium content in the test group decreased up to 28% compared to 100% in the sodium chloride group C1. The formulation including 60% sodium chloride and a total of 40% compound alternative salts in groups F1 and F2 increased their myofibril fragmentation index and promoted the disruption of the myogenic fiber structure. Group F1 (the ratio of potassium lactate, calcium ascorbate and magnesium chloride was 2:1:1) performed higher solubility of myofibrillar proteins and lower transverse relaxation value than group F2 detected by low-field nuclear magnetic resonance, which indicated that F1 formulation was beneficial to promote the solubility of myofibrillar proteins and attenuate the water mobility of marinated beef. Moreover, group F1 had a more similar microstructure and more similar overall sensory attributes to group C1 according to the scanning electron microscopy. The sensory evaluation showed higher peak intensity and response values of volatile flavor compounds than group C1 and C2 (only 60% sodium chloride) when detected using gas chromatography-ion mobility spectrometry technology, which indicated that the compound alternative salts of group F1 can improve the lower quality of low-sodium marinated beef and perform similar attributes to the C1 sample regarding moisture distribution and microstructure and even performs better than it with regards to flavor. Therefore, the F1 formula possessed greater potential for application in low-sodium marinated meat products.

Bi-allelic variants in DNAH3 cause male infertility with asthenoteratozoospermia in humans and mice

STUDY QUESTION

Are there other pathogenic genes for asthenoteratozoospermia (AT)?

SUMMARY ANSWER

DNAH3 is a novel candidate gene for AT in humans and mice.

WHAT IS KNOWN ALREADY

AT is a major cause of male infertility. Several genes underlying AT have been reported; however, the genetic aetiology remains unknown in a majority of affected men.

STUDY DESIGN SIZE DURATION

A total of 432 patients with AT were recruited in this study. DNAH3 mutations were identified by whole-exome sequencing (WES). Dnah3 knockout mice were generated using the genome editing tool. The morphology and motility of sperm from Dnah3 knockout mice were investigated. The entire study was conducted over 3 years.

PARTICIPANTS/MATERIALS SETTING METHODS

WES was performed on 432 infertile patients with AT. In addition, two lines of Dnah3 knockout mice were generated. Haematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), immunostaining, and computer-aided sperm analysis (CASA) were performed to investigate the morphology and motility of the spermatozoa. ICSI was used to overcome the infertility of one patient and of the Dnah3 knockout mice.

MAIN RESULTS AND THE ROLE OF CHANCE

DNAH3 biallelic variants were identified in three patients from three unrelated families. H&E staining revealed various morphological abnormalities in the flagella of sperm from the patients, and TEM and immunostaining further showed the loss of the central pair of microtubules, a dislocated mitochondrial sheath and fibrous sheath, as well as a partial absence of the inner dynein arms. In addition, the two Dnah3 knockout mouse lines demonstrated AT. One patient and the Dnah3 knockout mice showed good treatment outcomes after ICSI.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

This is a preliminary report suggesting that defects in DNAH3 can lead to asthenoteratozoospermia in humans and mice. The pathogenic mechanism needs to be further examined in a future study.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings show that DNAH3 is a novel candidate gene for AT in humans and mice and provide crucial insights into the biological underpinnings of this disorder. The findings may also be beneficial for counselling affected individuals.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from National Natural Science Foundation of China (82201773, 82101961, 82171608, 32322017, 82071697, and 81971447), National Key Research and Development Program of China (2022YFC2702604), Scientific Research Foundation of the Health Committee of Hunan Province (B202301039323, B202301039518), Hunan Provincial Natural Science Foundation (2023JJ30716), the Medical Innovation Project of Fujian Province (2020-CXB-051), the Science and Technology Project of Fujian Province (2023D017), China Postdoctoral Science Foundation (2022M711119), and Guilin technology project for people's benefit (20180106-4-7). The authors declare no competing interests.

Associations of elevated glucose levels at each time point during OGTT with fetal congenital heart diseases: a cohort study of 72,236 births

BACKGROUND

It remains unclear how the condition of glucose metabolism during pregnancy affects fetal outcomes. This study aimed to investigate the associations of gestational diabetes mellitus (GDM) and elevated glucose levels at each time point during oral glucose tolerance test (OGTT) with congenital heart disease (CHD) risk in offspring.

METHODS

We conducted a retrospective cohort study of mothers with singleton pregnancies of 20 weeks or more registered at Maternal and Child Health Centers in Fujian Province, China. The OGTT results and offspring CHD occurrence were collected. We used logistic regression to analyse the association between elevated blood glucose at each time point during OGTT and CHD.

RESULTS

A total of 71,703 normal and 533 CHD fetuses were included. Compared to the corresponding normal group, women with GDM, elevated blood glucose at different time points in OGTT (0 h ≥ 5.1 mmol/L, 1 h ≥ 10 mmol/L, and 2 h ≥ 8.5 mmol/L) showed an increased risk of CHD in offspring (adjusted OR = 1.41, 1.36, 1.37, and 1.41, all P < 0.05, respectively). Compared to group 1 (normal OGTT 0 h, 1 h and 2 h), the risk of CHD was higher in group 3 (normal OGTT 0 h and abnormal OGTT 1 h or 2 h) and group 4 (abnormal OGTT 0 h, 1 h and 2 h), OR = 1.53 and 2.21, all P < 0.05, respectively. Moreover, we divided participants by advanced maternal age, multipara, assisted reproduction, fetal sex, and others, similar associations were observed in the subgroup analyses.

CONCLUSION

Elevated blood glucose at different time points during OGTT was associated with CHD in offspring. Fetuses of pregnant women with GDM should be screened for a high risk of CHD.

A Novel Anderson-Type POMs-Based Hybrids Flame Retardant for Reducing Smoke Release and Toxicity of Epoxy Resins

Smoke emission and smoke toxicity have drawn more attention to improving the fire safety of polymers. In this work, a polyoxometalates (POMs)-based hybrids flame retardant (P-AlMo6 ) epoxy resin (EP) is prepared with toxicity-reduction and smoke-suppression properties via a peptide coupling reaction between POMs and organic molecules with double DOPO (bisDOPA). It combines the good compatibility of the organic molecule and the superior catalytic performance of POMs. Compared to pure EP, the glass transition temperature and flexural modulus of EP composite with 5 wt.% P-AlMo6 (EP/P-AlMo6 -5) are raised by 12.3 °C and 57.75%, respectively. Notably, at low flame-retardant addition, the average CO to CO2 ratio (Av-COY/Av-CO2 Y) is reduced by 33.75%. Total heat release (THR) and total smoke production (TSP) are lowered by 44.4% and 53.7%, respectively. The Limited Oxygen Index (LOI) value achieved 31.7% and obtained UL-94 V-0 rating. SEM, Raman, X-ray photoelectron spectroscopy, and TG-FTIR are applied to analyze the flame-retardant mechanism in condensed and gas phase. Outstanding flame retardant, low smoke toxicity properties are attained due to the catalytic carbonization ability of metal oxides Al2 O3 and MoO3 produced from the breakdown of POMs. This work advances the development of POMs-based hybrids flame retardants with low smoke toxicity properties.

A Novel P/N/Si-Containing Vanillin-Based Compound for a Flame-Retardant, Tough Yet Strong Epoxy Thermoset

It is still extremely challenging to endow epoxy resins (EPs) with excellent flame retardancy and high toughness. In this work, we propose a facile strategy of combining rigid-flexible groups, promoting groups and polar phosphorus groups with the vanillin compound, which implements a dual functional modification for EPs. With only 0.22% phosphorus loading, the modified EPs obtain a limiting oxygen index (LOI) value of 31.5% and reach V-0 grade in UL-94 vertical burning tests. Particularly, the introduction of P/N/Si-containing vanillin-based flame retardant (DPBSi) improves the mechanical properties of EPs, including toughness and strength. Compared with EPs, the storage modulus and impact strength of EP composites can increase by 61.1% and 240%, respectively. Therefore, this work introduces a novel molecular design strategy for constructing an epoxy system with high-efficiency fire safety and excellent mechanical properties, giving it immense potential for broadening the application fields of EPs.

LDH@Boronate Polymer Core-Shell Nanoparticles: Nanostructure Design for Synergistically Enhancing the Flame Retardancy of Epoxy Resin

As a promising nanofiller, layered double hydroxides (LDHs) can advance the fire safety of epoxy resin (EP), but so far, due to the problems of dispersion and low efficiency, it has still been a challenge to incorporate the flame retardancy and mechanical properties of EP nanocomposites effectively under the circumstance of a low additive amount. In this work, we take LDHs as the template, via the adsorption of a catechol group and the condensation polymerization between catechol groups and phenylboric acid groups, to prepare a core-shell structured nanoparticle LDH@BP, which contains rich flame-retardant elements. EP/LDH@BP nanocomposites were prepared by introducing LDH@BP into EP. The experimental results indicate that, compared with the original LDH, LDH@BP disperses uniformly in the EP matrix, and the flame retardancy and mechanical properties of EP/LDH@BP are significantly improved. At a relatively low content (5 wt%), EP/LDH@BP reached the rating of V-0 in the UL-94 test, LOI was increased to 29.1%, and peak heat release rate (PHRR) was reduced by 35.9% in cone calorimeter tests, which effectively inhibited the release of heat and toxic smoke during the combustion process of EP. Simultaneously, the mechanical properties of EP/LDH@BP have been improved satisfactorily. The above results derive from the reasonable architectural design of organic-inorganic nano-hybrid flame retardants and provide a novel method for the construction of efficient and balanced EP nanocomposite system with LDHs.

Periodic Acid Modification of Chemical-Bath Deposited SnO2 Electron Transport Layers for Perovskite Solar Cells and Mini Modules

Chemical bath deposition (CBD) has been demonstrated as a remarkable technology to fabricate high-quality SnO₂ electron transport layer (ETL) for large-area perovskite solar cells (PSCs). However, surface defects always exist on the SnO₂ film coated by the CBD process, impairing the devices' performance. Here, a facile periodic acid post-treatment (PAPT) method is developed to modify the SnO₂ layer. Periodic acid can react with hydroxyl groups on the surface of SnO₂ films and oxidize Tin(II) oxide to Tin(IV) oxide. With the help of periodic acid, a better energy level alignment between the SnO₂ and perovskite layers is achieved. In addition, the PAPT method inhibits interfacial nonradiative recombination and facilitates charge transportation. Such a multifunctional strategy enables to fabricate PSC with a champion power conversion efficiency (PCE) of 22.25%, which remains 93.32% of its initial efficiency after 3000 h without any encapsulation. Furthermore, 3 × 3 cm² perovskite mini-modules are presented, achieving a champion efficiency of 18.10%. All these results suggest that the PAPT method is promising for promoting the commercial application of large-area PSCs.

CBCT-based synthetic CT generated using CycleGAN with HU correction for adaptive radiotherapy of nasopharyngeal carcinoma

This study aims to utilize a hybrid approach of phantom correction and deep learning for synthesized CT (sCT) images generation based on cone-beam CT (CBCT) images for nasopharyngeal carcinoma (NPC). 52 CBCT/CT paired images of NPC patients were used for model training (41), validation (11). Hounsfield Units (HU) of the CBCT images was calibrated by a commercially available CIRS phantom. Then the original CBCT and the corrected CBCT (CBCT_cor) were trained separately with the same cycle generative adversarial network (CycleGAN) to generate SCT1 and SCT2. The mean error and mean absolute error (MAE) were used to quantify the image quality. For validations, the contours and treatment plans in CT images were transferred to original CBCT, CBCT_cor, SCT1 and SCT2 for dosimetric comparison. Dose distribution, dosimetric parameters and 3D gamma passing rate were analyzed. Compared with rigidly registered CT (RCT), the MAE of CBCT, CBCT_cor, SCT1 and SCT2 were 346.11 ± 13.58 HU, 145.95 ± 17.64 HU, 105.62 ± 16.08 HU and 83.51 ± 7.71 HU, respectively. Moreover, the average dosimetric parameter differences for the CBCT_cor, SCT1 and SCT2 were 2.7% ± 1.4%, 1.2% ± 1.0% and 0.6% ± 0.6%, respectively. Using the dose distribution of RCT images as reference, the 3D gamma passing rate of the hybrid method was significantly better than the other methods. The effectiveness of CBCT-based sCT generated using CycleGAN with HU correction for adaptive radiotherapy of nasopharyngeal carcinoma was confirmed. The image quality and dose accuracy of SCT2 were outperform the simple CycleGAN method. This finding has great significance for the clinical application of adaptive radiotherapy for NPC.

Qualitative study on diabetic cutaneous wound healing with radiation crosslinked bilayer collagen scaffold in rat model

Diabetes may leave patients more prone to skin problems, and minor skin conditions can more easily turn into serious damage to the extracellular matrix, which further impairs the skin's mechanical properties and delays wound healing. Therefore, the aim of the work is to develop extracellular matrix substitution to remodel the mechanical properties of diabetic cutaneous wound and thus accelerate diabetic wound healing. A green fabrication approach was used to prepare radiation crosslinked bilayer collagen scaffold from collagen dispersion. The morphological, mechanical and swelling characteristics of radiation crosslinked bilayer collagen scaffold were assessed to be suitable for cutaneous wound remodeling. The feasibility of radiation crosslinked bilayer collagen scaffold was performed on full-skin defect of streptozotocin-induced diabetic rats. The tissue specimens were harvested after 7, 14, and 21 days. Histopathological analysis showed that radiation crosslinked bilayer collagen scaffold has beneficial effects on inducing skin regeneration and remodeling in diabetic rats. In addition, immunohistochemical staining further revealed that the radiation crosslinked bilayer collagen scaffold could not only significantly accelerate the diabetic wound healing, but also promote angiogenesis factor (CD31) production. Vascularization was observed as early as day 7. The work expands the therapeutic ideas for cutaneous wound healing in diabetes.

Tcf21 Alleviates Pancreatic Fibrosis by Regulating the Epithelial-Mesenchymal Transformation of Pancreatic Stellate Cells

BACKGROUND AND AIMS

The activation of pancreatic stellate cells (PSCs) plays a key role in the occurrence and development of chronic pancreatitis (CP) and pancreatic fibrosis, which is related to the process of epithelial-mesenchymal transition (EMT). This study was designed to investigate the effect and mechanism of Tcf21 (one of tumor suppressor genes) on pancreatic inflammation and fibrosis in vivo and in vitro.

METHODS

C57BL/6 male mice were intraperitoneally injected with caerulein for 6 weeks to establish CP animal model. Fixed pancreatic tissue paraffin-embedded sections were used for immunohistochemistry staining of Tcf21, fibrosis-related markers (α-SMA), interstitial markers (Vimentin) and epithelial markers (E-cadherin). Western blotting and qRT-PCR assay were performed to analyze the change of expression of the above markers after stimulation of TGF-β1 or overexpressed Tcf21 lentivirus transfection in human pancreatic stellate cells (HPSCs).

RESULTS

The pancreatic expression of α-SMA and Vimentin of CP mice significantly increased, while the expression of Tcf21 and E-cadherin significantly decreased. TGF-β1 could promote activation and EMT process of HPSCs, and inhibited the expression of Tcf21. Overexpression of Tcf21 could significantly down-regulate the expression of α-SMA, Fibronectin and Vimentin, and up-regulated the expression of ZO-1 of HPSCs. Cell Counting Kit-8 assay and scratch wound-healing assay results showed that overexpression of Tcf21 could significantly inhibit the cell migration and proliferation of HPSCs.

CONCLUSIONS

Overexpression of Tcf21 could significantly alleviate the activation, proliferation, migration of PSCs by regulating the EMT process. Tcf21 had a potential prospect of a new target for CP therapy.

The Stability of Metal Halide Perovskite Nanocrystals-A Key Issue for the Application on Quantum-Dot-Based Micro Light-Emitting Diodes Display

The metal halide perovskite nanocrystal (MHP-NC), an easy-to-fabricate and low cost fluorescent material, is recognized to be among the promising candidates of the color conversion material in the micro light-emitting diode (micro-LED) display, providing that the stability can be further enhanced. It is found that the water steam, oxygen, thermal radiation and light irradiation-four typical external factors in the ambient environment related to micro-LED display-can gradually alter and destroy the crystal lattice. Despite the similar phenomena of photoluminescence quenching, the respective encroaching processes related to these four factors are found to be different from one another. The encroaching mechanisms are collected and introduced in separate categories with respect to each external factor. Thereafter, a combined effect of these four factors in an environment mimicking real working conditions of micro-LED display are also introduced. Finally, recent progress on the full-color application of MHP-NC is also reviewed in brief.