Interfacial ice sprouting during salty water droplet freezing.

Icing of seawater droplets is capable of causing catastrophic damage to vessels, buildings, and human life, yet it also holds great potential for enhancing applications such as droplet-based freeze desalination and anti-icing of sea sprays. While large-scale sea ice growth has been investigated for decades, the icing features of small salty droplets remain poorly understood. Here, we demonstrate that salty droplet icing is governed by salt rejection-accompanied ice crystal growth, resulting in freezing dynamics different from pure water. Aided by the observation of brine films emerging on top of frozen salty droplets, we propose a universal definition of freezing duration to quantify the icing rate of droplets having varying salt concentrations. Furthermore, we show that the morphology of frozen salty droplets is governed by ice crystals that sprout from the bottom of the brine film. These crystals grow until they pierce the free interface, which we term ice sprouting. We reveal that ice sprouting is controlled by condensation at the brine film free interface, a mechanism validated through molecular dynamics simulations. Our findings shed light on the distinct physics that govern salty droplet icing, knowledge that is essential for the development of related technologies.

scRNA-Seq and Bulk-Seq Analysis Identifies S100A9 Plasma Cells as a Potentially Effective Immunotherapeutic Agent for Multiple Myeloma.

Purpose: Immunological regimens are an important area of research for treating multiple myeloma (MM). Plasma cells play a crucial role in immunotherapy. Patients and Methods: In our study, we used both single-cell RNA sequencing (scRNA-seq) and bulk sequencing techniques to analyze MM patients. We analyzed each sample using gene set variation analysis (GSVA) based on immune-related gene sets. We also conducted further analyses to compare immune infiltration, clinical characteristics, and expression of immune checkpoint molecules between the H-S100A9 and L-S100A9 groups of MM patients. Results: We identified eight subpopulations of plasma cells, with S100A9 plasma cells being more abundant in patients with 1q21 gain and 1q21 diploid. CellChat analysis revealed that GAS and HGF signaling pathways were prominent in intercellular communication of S100A9 plasma cells. We identified 14 immune-related genes in the S100A9 plasma cell population, which allowed us to classify patients into the H-S100A9 group or the L-S100A9 group. The H-S100A9 group showed higher ESTIMATE, immune and stroma scores, lower tumor purity, and greater immune checkpoint expression. Patients with 1q21 gain and four or more copies had the lowest ESTIMATE score, immune score, stroma score, and highest tumor purity. Drug sensitivity analysis indicated that the H-S100A9 group had lower IC50 values and greater drug sensitivity compared to the L-S100A9 group. Quantitative reverse transcription (RT-q) PCR showed significantly elevated expression of RNASE6, LYZ, S100A8, S100A9, and S100A12 in MM patients compared to the healthy control group. Conclusion: Our study has identified a correlation between molecular subtypes of S100A9 plasma cells and the response to immunotherapy in MM patients. These findings improve our understanding of tumor immunology and provide guidance for developing effective immunotherapy strategies for this patient population.

Polyethylene glycol with dual three-dimensional porous carbon nanotube/diamond: a high thermal conductivity of composite PCM.

Polyethylene glycol (PEG) is widely used as a phase change material (PCM) in thermal energy storage systems due to its high latent heat and chemical stability. However, practical application has been hindered by its low thermal conductivity and leakage issues. Therefore, developing shape-stable high thermal conductivity PCM is of great importance. In this study, new shape-stable composite PCM with high thermal conductivity and leak-prevention capabilities were designed. The porous carbon skeleton of diamond foam (DF) and dual-3D carbon nanotube-diamond foam (CDF) were prepared using the microwave plasma chemical vapor deposition method. The composite materials (DF/PEG and CDF/PEG) were produced by vacuum impregnation with PEG and skeletons. The results showed that CDF/PEG had the highest thermal conductivity, measuring 2.30 W·m-1·K-1, which is 707% higher than that of pure PEG. The employing of 3D networks of CNTs, which can improve the phonon mean free path in DF/PEG (1.79 W·m-1·K-1) while reducing phonon dispersion.The phonon vibration of dual-3D CDF plays an important role in heat transfer. PEG was physically absorbed and well-distributed in CDF, alleviating leakage of liquid PEG. The weight loss of CDF/PEG was only 25% at 70 °C for 120 s. Using CDF is an attractive and efficient strategy to increase the heat transfer of PEG and improve heat storage efficiency, alleviate the problem of poor shape-stability.

Regulated Thermal Boundary Conductance between Copper and Diamond through Nanoscale Interfacial Rough Structures.

Interfacial structure optimization is important to enhance the thermal boundary conductance (TBC) as well as the overall performance of thermal conductive composites. In this work, the effect of interfacial roughness on the TBC between copper and diamond is investigated with molecular dynamics (MD) simulations and time-domain thermoreflectance (TDTR) experiments. It is found from MD simulations that the thermal transport efficiency across a rough interface is higher, and the TBC can be improved 5.5 times to 133 MW/m2·K compared with that of the flat interface. Also, the TBC is only dominated by the actual contact area at the interface for larger roughness cases; thus, we conclude that the phonon scattering probability increases with the increase of roughness and becomes stable gradually. Finally, the TBC of the copper/diamond interface with different roughness is characterized by TDTR experiments, and the results also confirm the trend of MD simulations. This study demonstrates the feasibility of the roughness modification for interfacial thermal management from both theoretical analysis and experimental measurements and provides a new idea for enhancing the thermal conductivity of composites.

Polypyrrole coated carbon nanotube aerogel composite phase change materials with enhanced thermal conductivity, high solar-/electro- thermal energy conversion and storage.

Phase change materials (PCMs) have been widely investigated as promising thermal management materials due to their high thermal storage capacity, satisfactory heat transfer rate and multi-responsive energy conversion and storage characteristics. In this work, a shape-stabilized solar-/electro- responsive thermal energy capture and storage system is proposed involving polypyrrole (PPy)-deposited carbon nanotubes (CNT) heterogeneous porous aerogel as a supporting matrix and the paraffin wax (PW) as a PCM. The composite PCMs obtained via integration of PW into aerogel supports present a relatively high thermal storage density of 160.9 J/g and outstanding phase transition stability even after 100 heating-cooling cycles. Furthermore, great enhancement of thermal conductivity (0.64 W/m-1·K-1, 2.56 times that of PW) is achieved in the composite PCMs by inducing PPy coating as a binder in the gap between CNTs. The mechanism of heat transport enhancement is explored by molecular dynamics simulation. It concludes that the in-situ polymerization of PPy through the vapor deposition method on the CNT aerogels effectively builds additional thermal transfer channels and enhances the heat transport between CNT by coordinating the carbon atom vibration. Herein, this reported stratagem may shed light on preparing composite PCMs with high thermal conductivity and multi-energy utilization functions.

Comparison and analysis of multiple machine learning models for discriminating benign and malignant testicular lesions based on magnetic resonance imaging radiomics.

Objective: Accurate identification of testicular tumors through better lesion characterization can optimize the radical surgical procedures. Here, we compared the performance of different machine learning approaches for discriminating benign testicular lesions from malignant ones, using a radiomics score derived from magnetic resonance imaging (MRI). Methods: One hundred fifteen lesions from 108 patients who underwent MRI between February 2014 and July 2022 were enrolled in this study. Based on regions-of-interest, radiomics features extraction can be realized through PyRadiomics. For measuring feature reproducibility, we considered both intraclass and interclass correlation coefficients. We calculated the correlation between each feature and the predicted target, removing redundant features. In our radiomics-based analysis, we trained classifiers on 70% of the lesions and compared different models, including linear discrimination, gradient boosting, and decision trees. We applied each classification algorithm to the training set using different random seeds, repeating this process 10 times and recording performance. The highest-performing model was then tested on the remaining 30% of the lesions. We used widely accepted metrics, such as the area under the curve (AUC), to evaluate model performance. Results: We acquired 1,781 radiomic features from the T2-weighted maps of each lesion. Subsequently, we constructed classification models using the top 10 most significant features. The 10 machine-learning algorithms we utilized were capable of diagnosing testicular lesions. Of these, the XGBoost classification emerged as the most superior, achieving the highest AUC value of 0.905 (95% confidence interval: 0.886-0.925) on the testing set and outstripping the other models that typically scored AUC values between 0.697-0.898. Conclusion: Preoperative MRI radiomics offers potential for distinguishing between benign and malignant testicular lesions. An ensemble model like the boosting algorithm embodied by XGBoost may outperform other models.

Physiological and transcriptomic analysis dissects the molecular mechanism governing meat quality during postmortem aging in Hu sheep (Ovis aries).

Introduction: Hu sheep, known for its high quality and productivity, lack fundamental scientific research in China. Methods: This study focused on the effects of 24 h postmortem aging on the meat physiological and transcriptomic alteration in Hu sheep. Results: The results showed that the 24 h aging process exerts a substantial influence on the mutton color, texture, and water content as compared to untreated group. Transcriptomic analysis identified 1,668 differentially expressed genes. Functional enrichment analysis highlighted the importance of glycolysis metabolism, protein processing in endoplasmic reticulum, and the FcγR-mediated phagocytosis pathway in mediating meat quality modification following postmortem aging. Furthermore, protein-protein interaction analysis uncovered complex regulatory networks involving glycolysis, the MAPK signaling pathway, protein metabolism, and the immune response. Discussion: Collectively, these findings offer valuable insights into the molecular mechanisms underlying meat quality changes during postmortem aging in Hu sheep, emphasizing the potential for improving quality control strategies in mutton production.

Superhydrophobic Strategy for Nature-Inspired Rotating Microfliers: Enhancing Spreading, Reducing Contact Time, and Weakening Impact Force of Raindrops.

Wind-dispersal of seeds is a remarkable strategy in nature, enlightening the construction of microfliers for environmental monitoring. However, the flight of these microfliers is greatly affected by climatic conditions, especially in rainy days, they suffer serious raindrop impact. Here, a hierarchical superhydrophobic surface is fabricated and a novel strategy is demonstrated that the superhydrophobic coating can enhance spreading while reduce contact time and impact force of raindrops, all of which are beneficial for the rotating microfliers. When the surface rotating speed exceeds a critical value, the effect of centrifugal force becomes considerable so that the droplet spreading is enhanced. The rotating superhydrophobic surface can rotate an impacting droplet by the tangential drag force from the air boundary layer, and the rotation of the droplet generates a negative pressure zone inside it, reducing the contact time by more than 30%. The impact force by the droplet on the rotating superhydrophobic surface also has a remarkable reduction of 53% compared to that on unprocessed hydrophilic surfaces, which helps maintain the flight stability of the microfliers. This work pioneers in revealing the droplet impact effect on rotating microflier surfaces and demonstrates the effectiveness of protecting microfliers with superhydrophobic coatings, which shall guide the manufacture and flight of microfliers in rainy conditions.

Synergistical thermal modulation function of 2D Ti3C2 MXene composite nanosheets via interfacial structure modification.

MXene demonstrates high in-plane thermal transport merit as an emerging two-dimensional material, but its out-of-plane thermal transport did not fully explore. Here Ti3C2 MXene nanosheets with either GO or CNF fillers were fabricated by using the vacuum-assisted filtration method. It was found that the addition of GO and CNF enlarged the interlayer spacing of the MXene layers, bringing about the opportunity for changeable spatial configuration of fillers and the thermal regulation function. If the GO nanosheets were interspersed parallel to the MXene layers, strong interference of increasing oxygen-containing functional group suppresses the out-of-plane thermal transport, resulting in the thermal conductivity decreasing from 0.5 W/(m·K) to 0.31 W/(m·K) for 20 wt% GO addition. Moreover, CNFs formed out-of-plane protruding on the surface of MXene nanosheets, resulting in the thermal conductivity increasing to 0.81 W/(m·K) for 20 wt% CNF addition. This discovery navigates how to prepare MXene composites with customized thermal properties.

Bimetallic Multi-Level Layered Co-NiOOH/Ni3 S2 @NF Nanosheet for Hydrogen Evolution Reaction in Alkaline Medium.

Development of efficient non-noble metal catalysts for water splitting is of great significance but challenging due to the sluggish kinetics of the hydrogen evolution reaction (HER) in alkaline medium. Herein, a bimetallic multi-level layered catalytic electrode composed of Ni3 S2 nanosheets with secondary Co-NiOOH layer of 3D porous and free-standing cathode in alkaline medium is reported. This integrated synergistic catalytic electrode exhibits excellent HER electrocatalytic performance. The resultant Ni0.67 Co0.33 /Ni3 S2 @NF electrode displays the highest HER activity with only overpotentials of 87 and 203 mV to afford current densities of 10 and 100 mA·cm-2 , respectively, and its Tafel slope is 80 mV·dec-1 . The chronopotentiometry operated at high current density of 50 mA·cm-2 shows negligible deterioration, indicating better stability of Ni0.67 Co0.33 /Ni3 S2 @NF electrode than Pt/C (20 wt.%). Such a desirable catalytic performance is attributed to the modification of physical and electronic structure that exposes abundant active sites and improves the intrinsic catalytic activity toward HER, which is also confirmed by electrochemically active surface area and X-ray photoelectron spectroscopy analysis. This work provides a strong support for the rational design of high-performance bimetallic electrodes for industrial water splitting.

Enhanced Moisture Condensation on Hierarchical Structured Superhydrophobic-Hydrophilic Patterned Surfaces.

Patterned surfaces combining hydrophobic and hydrophilic properties show great promise in moisture condensation; however, a comprehensive understanding of the multiscale interfacial behavior and the further controlling method is still lacking. In this paper, we studied the moisture condensation on a hybrid superhydrophobic-hydrophilic surface with hierarchical structures from micro- to nanoscale. For the first time, we demonstrated the effects of wettability difference and microstructure size on the final condensation efficiency. By optimizing the wettability difference, sub-millimeter pattern width, and microstructure size, maximum 90% enhancement of the condensation rate was achieved as compared with the superhydrophobic surface at a subcooling of 13 K. We also demonstrated the enhanced condensation mechanism by a detailed analysis of the condensation process. Our work proposed effective and systematical methods for controlling and optimizing moisture condensation on the patterned surfaces and shed light on application integration of such promising functional surfaces.

Freestanding Flexible Sensor Based on 3ω Technique for Anisotropic Thermal Conductivity Measurement of Potassium Dihydrogen Phosphate Crystal.

A new freestanding sensor-based 3ω technique is presented here, which remarkably expands the application of traditional 3ω technology to anisotropic materials. The freestanding flexible sensor was fabricated using the mature flexible printed circuit production technique, which is non-destructive to the samples and applicable to porous surfaces. The thermal conductivities of potassium dihydrogen phosphate (KDP) crystal along the (100), (010) and (001) crystallographic planes were measured based on this new sensor at room temperature. We found that the freestanding flexible sensor has considerable application value for thermal properties' characterization for crystals with anisotropic thermophysical properties and other structures for which the traditional 3ω technique is not applicable.

Large-Scale Dewetting via Surfactant-Laden Droplet Impact.

The dewetting phenomenon of a liquid film in the presence of a surfactant exists in various natural, industrial, and biomedical processes but still remains mysterious in some specific scenarios. Here, we investigate the dewetting behavior of water films initiated by surfactant-laden droplet impact and show that the maximum dewetting diameter can even reach more than 50 times that of the droplet size. We identify the S-type variation of the dewetting area and demonstrate its correlation to the dynamic surface tension reduction. From a viewpoint of energy conversion, we attribute the dewetting to the released surface energy caused by the surfactant addition and establish a linear relation between the maximum dewetting and the surfactant concentration in the film, i.e., dmax2 ∝ cfilm, which agrees well with the experiments. These results may advance the physics of liquid film dewetting triggered by surfactant injection, which shall further guide practical applications.

Development and Validation of a CD8+ T Cell Infiltration-Related Signature for Melanoma Patients.

Aim: Immunotherapy shows efficacy in only a subset of melanoma patients. Here, we intended to construct a risk score model to predict melanoma patients' sensitivity to immunotherapy. Methods: Integration analyses were performed on melanoma patients from high-dimensional public datasets. The CD8+ T cell infiltration related genes (TIRGs) were selected via TIMER and CIBERSORT algorithm. LASSO Cox regression was performed to screen for the crucial TIRGs. Single sample gene set enrichment analysis (ssGSEA) and ESTIMATE algorithm were used to evaluate the immune activity. The prognostic value of the risk score was determined by univariate and multivariate Cox regression analysis. Results: 184 candidate TIRGs were identified in melanoma patients. Based on the candidate TIRGs, melanoma patients were classified into three clusters which were characterized by different immune activity. Six signature genes were further screened out of 184 TIRGs and a representative risk score for patient survival was constructed based on these six signature genes. The risk score served as an indicator for the level of CD8+ T cell infiltration and acted as an independent prognostic factor for the survival of melanoma patients. By using the risk score, we achieved a good predicting result for the response of cancer patients to immunotherapy. Moreover, pan-cancer analysis revealed the risk score could be used in a wide range of non-hematologic tumors. Conclusions: Our results showed the potential of using signature gene-based risk score as an indicator to predict melanoma patients' sensitivity to immunotherapy.

Effect of the rotation errors on the γ pass rate of volume-modulated arc therapy plan in rectal cancer. / æ—‹è½¬è¯¯å·®å¯¹ç›´è‚ ç™Œå®¹ç§¯æ—‹è½¬è°ƒå¼ºæ”¾å°„æ²»ç–—éªŒè¯è®¡åˆ’Î³é€šè¿‡çŽ‡çš„å½±å“.

OBJECTIVES: To study the effect of rotation errors on the γ pass rate of volume-modulated arc therapy (VMAT) plan in rectal cancer based on the ArcCheck phantom. METHODS: CT data from 20 rectal cancer patients underwent VMRT were selected randomly for this study. Targeting areas were selected, and clinical radiotherapy and validation plans were formulated. ArcCheck model was selected to validate the radiotherapy plans. The effect of the rotation errors on the dosimetric verification for VMAT in rectal cancer was simulated and analyzed with ArcCheck model software. RESULTS: When there was no rotation errors, the γ pass rate of VMRT plans was more than 95%. When the absolute rotation angle was less than or equal to 1°, the γ pass rate of VMAT plans was more than 90%, meeting the clinical requirements. When the absolute rotation angle was greater than 1°, the γ pass rate was less than 90%, which did not meet clinical requirements. CONCLUSIONS: The rotation errors affect the γ pass rate of VMAT plans. The larger the rotation angle, the lower the γ pass rate. It meets clinical requirements when the rotation error is less than or equal to 1°.

In vivo skin thermophysical property testing technology using flexible thermosensor-based 3ω method.

Thermophysical properties of human skin surface and subsurface can reflect the hydration state of the skin and the blood flow rate in the near surface microvessels, which reveals important physiological information related to dermatology and overall health status of human body. Although a few techniques have been developed to measure these signs, complicated devices are required and the subjects need to be completely fixed during the test period. Here, a flexible thermosensor-based 3ω technology was used to monitor thermal conductivity of human skins at different states. Through the analysis of these characteristics, the corresponding physiological state can be established, which can provide a new detection method for the evaluation or prediction of human health status.

In situ confined growth of ultrasmall perovskite quantum dots in metal-organic frameworks and their quantum confinement effect.

The metal halide perovskite quantum dots (APbX3 PeQDs; A = Cs or CH3NH3; X = Cl, Br or I) have emerged as a new type of promising optoelectronic material for light-emitting and photovoltaic applications because of their excellent optical properties. However, the precise control over the size and photoluminescence (PL) emission of APbX3 PeQDs remains a great challenge, which has been one of the main obstacles to the applications of PeQDs. Herein, we report a unique strategy for in situ confined growth of MAPbBr3 (MA = CH3NH3) PeQDs by using porous metal-organic framework (MOF) UiO-66 as a matrix. By introducing Pb(Ac)2 and MABr precursors into the pores of UiO-66 via a stepwise approach, ultrasmall MAPbBr3 PeQDs were in situ grown in the matrix with the size tuned from 6.4 to 3.3 nm by changing the concentration of the Pb(Ac)2 precursor. Accordingly, the PL emission wavelength of the resulting MAPbBr3 PeQDs was blue-shifted from 521 to 486 nm with the size reduction, owing to the strong quantum confinement effect of the PeQDs. Due to the surface passivation effect endowed by the UiO-66 matrix, the ultrasmall MAPbBr3 PeQDs also displayed a high PL quantum yield (PLQY) of 43.3% and a long PL lifetime of 100.3 ns. This study proposes a new strategy to prepare ultrasmall PeQDs and effectively control their sizes and PL emissions, which may open up new avenues for the development of high-performance luminescent PeQDs for diverse applications.

Effect of the loading amount and arrangement of iodine chains on the interfacial thermal transport of carbon nanotubes: a molecular dynamics study.

Due to their excellent electrical and thermal conductivity properties, the nano-scale characteristics of carbon nanotubes (CNTs) are expected to be suitable for very large-scale integrated circuits and for next-generation micro interconnected devices. Consequently, CNT-metal composite materials have been widely researched, and have shown excellent performance in terms of thermal conductivity, electrical conductivity, thermal expansion, and adaptability to microelectronic devices. However, there are few studies on halogen-CNT composite materials with characteristics similar to CNT-metal composites, including regarding the remarkable electrical compatibility of the halogen and CNT and the large number of low-frequency phonons that are beneficial for thermal transport. In this work, iodine chains were considered to explore the halogen effect on CNTs. Variation of the interfacial thermal conductance of CNTs as a function of the iodine chains loading amount and arrangement was explored by a molecular dynamics method. The heat transfer mechanism was further analyzed based on the phonon state difference. This research is expected to provide a new pathway for the application of CNT composite materials in the field of next-generation microelectronics.

Thermal conductance bottleneck of a three dimensional graphene-CNT hybrid structure: a molecular dynamics simulation.

Three dimensional (3D) graphene-CNT hybrid structures (GCNTs) are promising materials for applications including capacitors and gas storage and separation devices, however until now their thermal conductance mechanism has scarcely been studied. These hybrid nanomaterials are particularly suitable as next-generation thermal interface materials due to the excellent thermal properties of carbon nanotubes and single atomic layer graphene. In this paper, the out-of-plane thermal conductivities of GCNTs, graphene nanomesh (GNM), and graphene sheets are investigated using molecular dynamics (MD) simulations which apply the Green-Kubo method. Distinct from GNMs and graphene sheets, the GCNTs exhibit a relatively high out-of-plane thermal conductivity, stemming from the CNTs' ability to accelerate the energy flow. However, the GCNT out-of-plane thermal conductivity is still far lower than that of pristine graphene due to extreme phonon localizations, which are concentrated on the graphene-CNT junction regions as evidenced by the participation ratio, phonon vibrational density of states, and overlap energy. This study provides microscopic insight into the GCNT heat transfer mechanism and offers design guidelines for application of GCNTs in thermal management devices.

Highly Conducting Polythiophene Thin Films with Less Ordered Microstructure Displaying Excellent Thermoelectric Performance.

Polythiophene (PTh) with highly regular molecular structure is synthesized as nearly amorphous thin films by electrochemical methods in a BFEE/DTBP mixed medium (BFEE = boron fluoride ethyl ether; DTBP = 2,6-di-tert-butypyridine). The doping level and film morphology of PTh are modulated through adjusting the current density applied during the polymerization process. A combined analysis with solid-state NMR, FT-IR, and Raman spectra reveals the molecular structural regularity of the resulted PTh films, which leads to the highest electrical conductivity up to 700 S cm-1 for films obtained under an optimized current density of 1 mA cm-2 . By applying the self-heating 3ω-method, thermal conductivities are measured along the in-plane direction. A highly reduced Lorenz number of 6.49 × 10-9 W Ω K-2 and low lattice thermal conductivity of 0.21 W m-1 K-1 were extracted based on the analyses of the electrical and thermal conductivities according to the Wiedemann-Franz Law; the former is about one-third of the Sommerfeld value. Finally, the maximized ZT value can reach up to 0.10 under room temperature, which shows that the highly conducting polymers with less ordered structure is the practical direction for developing organic thermoelectric materials.