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The details of the interaction of human thermal plume and breathing activities are simulated in the current study of an unsteady turbulent flow field in an elevator cabin. Air velocity and temperature distributions of the circulation flow pattern (i.e., the macroenvironment), the breathing-scale microenvironment's characteristics, and the thermal plume's fate are analyzed. The current study is aimed at showing how respiratory activities such as breathing and human thermal plumes affect the flow field and respiratory contaminants dispersion pattern in a nonventilated enclosed environment (the elevator cabin). The results from three cases, i.e., breathing thermal manikins, nonbreathing thermal manikins, and isothermal breathing manikins, are contrasted to unveil better the effects of human thermal plume and breathing on the flow field, including the velocity distribution, dispersion pattern of the exhaled contaminant, the human body's heat transfer coefficient, and the large-scale flow pattern. Results reveal that breathing inhalation increases the upward velocity of the thermal plume on the one hand, which directly affects the microenvironment and indirectly impacts the macroenvironment due to the more vigorous reflected thermal plume. On the other hand, the upward thermal plume reduces the penetration length of the exhaled jet. Breathing activities create ring vortices that connect the microenvironment and the macroenvironment. The circulation flow features a downward flow in the cabin's center, affecting the vortex strength and contaminant dispersion pattern. Overall, the human thermal plume and human breathing make comparable contributions to the resulting elevator-cabin flow characteristics. [ABSTRACT FROM AUTHOR]

Communities of interest promote knowledge sharing and discovery in social network platforms. However, platform users face difficulties of finding suitable communities, given their increasing number. Although recommendations have been proposed to help users find communities of interest, these methods ignore or exclude heterogeneous interactions between users and communities. In addition, widely used meta-paths help capture the complex semantic relation among entities but heavily rely on domain knowledge. In this study, we propose a novel recommendation model based on informative meta-path discovery in heterogeneous information networks and deep learning. Users, communities, relevant items and their relations are considered as entities in a heterogeneous information network, from where informative meta-paths are extracted on the basis of information theory to measure user-community similarities. Finally, similarities are incorporated in a deep learning model to predict whether target users join candidate communities. The proposed recommendation model is evaluated and compared against baseline methods using two data sets. Results demonstrate the superior performance of the present model in terms of precision, recall and F score. [ABSTRACT FROM AUTHOR]

Patent transfer is a common practice for companies to obtain competitive advantages. However, they encounter the difficulty of selecting suitable patents because the number of patents is increasingly large. Many patent recommendation methods have been proposed to ease the difficulty, but they ignore patent quality and cannot explain why certain patents are recommended. Patent quality and recommendation explanations affect companies' decision-making in the patent transfer context. Failing to consider them in the recommendation process leads to less effective recommendation results. To fill these gaps, this paper proposes an interpretable patent recommendation method based on knowledge graph and deep learning. The proposed method organizes heterogeneous patent information as a knowledge graph. Then it extracts connectivity and quality features from the knowledge graph for pairs of patents and companies. The former features indicate the relevance of the pairs while the latter features reflect the quality of the patents. Based on the features, we design an interpretable recommendation model by combining a deep neural network with a relevance propagation technique. We conduct experiments with real-world data to evaluate the proposed method. Recommendation lists with varying lengths show that the average precision, recall, and mean average precision of the proposed method are 0.596, 0.636, and 0.584, which improve corresponding performance of best baselines by 7.28%, 18.35%, and 8.60%, respectively. Besides, our method interprets recommendation results by identifying important features leading to the results. [ABSTRACT FROM AUTHOR]

Healthcare platforms have attracted many physicians and provided convenient medical services to patients. However, the large number of physicians brings the difficulty of finding suitable physicians for the patients. Despite attempts to develop recommendation methods to address this challenge, they fail to leverage multimodal medical data, which contain numerical, categorical, textual and visual data valuable for inferring patients’ preferences for physicians. Besides, previous methods ignore the semantic gap between patients’ health conditions and physicians’ specialties. The conditions describe the patients’ symptoms, while the specialties indicate the diseases the physicians can treat. They have different vocabularies and cannot be directly compared for generating recommendations. We put forward an innovative physician recommendation approach to effectively address the above research gaps. Our approach entails merging multimodal data with multiple network modules and employing a medical knowledge graph to fill the semantic gap. To assess the validity of our suggested approach, we perform comprehensive trials on real-world data. The trial outcomes indicate that our approach surpasses its variants and existing methods in the aspects of HR@k, MRR@k and NDCG@k. [ABSTRACT FROM AUTHOR]

Laser shock peening, an advanced technology for severe surface plasticity peening, encounters challenges such as shallow hardened layers and surface spalling when dealing with difficult-to-machine materials. In this study, we introduced a high-frequency electropulsing-assisted laser shock peening (HFEP-LSP) technique that coupled laser shock peening with high-frequency electric pulses to achieve a significant and deeper plastic deformation layer. In the HFEP-LSP technique, we first considered the dual "skin effect", which coupled the skin effect of high-frequency electric pulses with the "skin effect" of the mechanical effect induced by the laser shock wave. An integrated experimental platform comprising an electric pulse generator, laser shock peening equipment, and a control system was built. A >1.6 mm deep compressive residual stress layer was obtained, and the depth of the plastic deformation layer increased by 83.3 %. Furthermore, we elucidated the dual "skin effect"-induced complex heterostructure and β m phase transition. A comprehensive analysis revealed the factors contributing to the deeper strengthening layer induced by HFEP-LSP, including the compressive residual stress and plastic deformation layers. In addition, the effects of laser shock peening and HFEP-LSP on the mechanical properties were investigated. Compared to the annealed samples, the ultimate tensile strength and elongation of the HFEP-LSP-treated samples were increased by 12.3 % and 57.1 %, respectively, with a fatigue life improvement of 176.4 %. The mechanism of synergistic improvement in strength and ductility was demonstrated. [Display omitted] • High-frequency electropulsing-assisted laser shock peening (HFEP-LSP) was proposed. • HFEP-LSP-induced dual skin effect was found for the first time. • Dual skin effect induced heterogenous structure and metastable β m phase. • Formation mechanism of ultra-deep compressive residual stress layer was elucidated. • Synergistic improvement in strength-ductility mechanism was explained. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel analytical model is proposed for the stress distribution of the laser shock wave and the equation for LSW-induced residual strain in visco–elastic–plastic materials. • An approximate equation of the maximum micro-dimple depth induced by laser shock wave is derived. • The model provides a new insight into the promotion and application of laser shock peening in different industries. Laser shock peening (LSP) is an advanced surface strengthening technology that uses laser shock waves (LSWs) to induce severe plastic deformation, considerable compressive residual stress, and grain refinement, and thereby improve the fatigue performance of metallic materials. Understanding the spatiotemporal distribution of the stress wave is important for precisely managing the strengthening effect of LSP. In this paper, the stress distribution of LSWs and the equation for LSW-induced residual strain in visco-elasto-plastic materials are presented. The formation of LSW-induced micro dimples on the surface is noteworthy. We derived an approximate equation for the maximum micro-dimple depth induced by LSWs. Finally, we measured the micro-dimple depths induced by LSWs at different peak pressures and verified the reliability of the theoretical calculation by comparing the calculated data with the experimental data. The micro-dimple depth can serve as an indicator of the effectiveness of LSP and improvement in fatigue performance. This characteristic can be utilized as a non-destructive testing method. This study has demonstrated the potential for promoting and applying of LSP in different industries. [ABSTRACT FROM AUTHOR]

Purpose: Recommending suitable doctors to patients on healthcare consultation platforms is important to both the patients and the platforms. Although doctor recommendation methods have been proposed, they failed to explain recommendations and address the data sparsity problem, i.e. most patients on the platforms are new and provide little information except disease descriptions. This research aims to develop an interpretable doctor recommendation method based on knowledge graph and interpretable deep learning techniques to fill the research gaps. Design/methodology/approach: This research proposes an advanced doctor recommendation method that leverages a health knowledge graph to overcome the data sparsity problem and uses deep learning techniques to generate accurate and interpretable recommendations. The proposed method extracts interactive features from the knowledge graph to indicate implicit interactions between patients and doctors and identifies individual features that signal the doctors' service quality. Then, the authors feed the features into a deep neural network with layer-wise relevance propagation to generate readily usable and interpretable recommendation results. Findings: The proposed method produces more accurate recommendations than diverse baseline methods and can provide interpretations for the recommendations. Originality/value: This study proposes a novel doctor recommendation method. Experimental results demonstrate the effectiveness and robustness of the method in generating accurate and interpretable recommendations. The research provides a practical solution and some managerial implications to online platforms that confront information overload and transparency issues. [ABSTRACT FROM AUTHOR]

Summary: Background: Despite the worldwide prevalence of dermatophyte infections, only a few genes are reported to be related to dermatophyte infections. In addition, the mechanism by which different ecological dermatophytes infection leads to varying intensity of inflammation remains unclear. Objectives: To investigate the mechanism of varying intensity of skin inflammation caused by different ecological dermatophytes infection. Methods: We infected HaCaT cells with anthropophilic and geophilic dermatophytes to mimic various ecological dermatophyte infections. RNA‐sequencing (RNA‐seq) was employed to identify the change in the gene expression of HaCaT cells. To verify the expression of differentially expressed genes (DEGs), we selected 18 HaCaT cells genes to conduct qPCR experiments. In addition, immunoblotting was conducted to validate key genes from the MAPK signalling pathway. Results: After HaCaT cells were infected with the anthropophilic Trichophyton rubrum (T rubrum) and the geophilic Microsporum gypseum (M gypseum), 118 and 619 differentially expressed genes were identified in HaCaT cells, respectively. These genes may provide a clue as to how keratinocytes respond to anthropophilic and geophilic dermatophytes. We also found that JUN may play a critical role in keratinocytes infected with M gypseum. Conclusions: Differential gene expression in HaCaT cells may account for the various clinical presentation caused by anthropophilic and geophilic dermatophytes infections. In addition, the intense inflammatory reaction of M gypseum infection may be triggered by activating the JNK‐JUN signalling pathway. [ABSTRACT FROM AUTHOR]

• The fatigue crack initiation life and fatigue life both increase with the increasing LSP coverage layers. • The martensitic lath refinement and carbide fragment through dislocation movement and carbide precipitations are also characterized. • A nucleation equation by ultrahigh-strain-rate plastic deformation is developed. • LSP-induced enhancement mechanism as a function of the LSP coverage layer was revealed. Fatigue properties and plastic deformation-induced gradient nanostructures of 2Cr13 martensitic stainless steel subjected to laser shock peening (LSP) were investigated. Combining the residual stresses and microstructural evolution of 2Cr13 martensitic stainless steel before and after three-point bending fatigue test, the influences of LSP on fatigue crack initiation and growth are systematically analyzed. Results showed that massive LSP treatments with one and two coverage layers caused obvious improvements of 13% and 37.6% in the fatigue crack initiation life, 19.3% and 34.9% in the fatigue lives of 2Cr13 stainless steel, respectively. Typical in-depth microstructures for two kinds of LSP-treated specimens were described by transmission electron microscopy characterization. Results showed that dynamic recrystallization (DRX) process at room temperature may be activated and accelerated by LSP-induced atom collision, and then a nucleation equation by ultrahigh-strain-rate plastic deformation was developed, which depended strongly on LSP-induced ultrahigh strain rate. Moreover, the basic improvement mechanism of LSP on fatigue properties was analyzed in detail. [ABSTRACT FROM AUTHOR]

Grain refinement and arrangement is an effective strategy to enhance tensile and fatigue properties of key metallic components. Laser shock peening (LSP) is one of surface severe plastic deformation methods in extreme conditions, with four distinctive features, namely, high pressure (1 GPa–1 TPa), high energy (more than 1 GW), ultra-fast (no more than nanosecond scale), and ultra-high strain rate (more than 106 s−1), and generates a deeper compressive residual stress (CRS) field and the formation of a gradient nanostructure in the surface layer to prevent the crack initiation of metallic materials and alloys, which is widely used in aerospace, overload vehicle, ocean engineering, and nuclear power. Despite some investigations of LSP on surface integrity, microstructural evolution, and mechanical properties of metallic materials and alloys, there is a lack of a comprehensive perspective of LSP-induced microstructural evolution, mechanical properties for metallic materials and alloys in the last two decades. Furthermore, the relationship between the mechanical properties of metallic materials and alloys and the LSP processing parameters is presented. In particular, LSP-induced featured microstructure and grain refinement mechanisms in three kinds of crystal structures, for instance, face-centred cubic, body-centred cubic, and hexagonal close-packed metals, are present and summarised for the first time. In addition, some new emerging hybrid LSP technologies and typical industrial applications as important chapters are shown. Finally, the faced challenges and future trends in the next 10–20 years are listed and discussed. Results to date indicate that LSP, as an emerging and novel surface modification technology, has been increasingly used to surface layer of metallic components. These topics discussed could provide some important insights on researchers and engineers in the fields of surface modification and advanced laser manufacturing. [Display omitted] • Laser shock peening-induced microstructures of metallic materials are summarised. • Effects of laser shock peening on mechanical properties of materials are summarised. • Correlation among process, microstructure, property is discussed. • Perspectives on research opportunities in laser shock peening are outlooked. [ABSTRACT FROM AUTHOR]

The research on new functional layer materials and optimization of fabrication in organic light-emitting diode (OLED) has been continuously concerned. In this work, phosphotungstic acid solution used as a precursor is spin-coated onto ITO anode, and then a phosphorus-tungsten oxide (WO 3 -P 2 O 5 ) film is obtained after annealing treatment. Various parameters which include film composition, surface morphology, work function and optical property are measured. It suggests that the film has the composition of 24 WO 3 ·P 2 O 5 annealed at 200 °C, which exhibits work function of 5.55 eV, surface root mean square (RMS) roughness value of 1.525 nm and optical transmittance of over 92%. The WO 3 -P 2 O 5 film is used as hole injection layer (HIL), and the OLED with the structure of [ITO/ WO 3 -P 2 O 5 / TPD/ Alq 3 / LiF/ Al] is fabricated. The performance of device shows turn-on voltage of 2.6 V, maximum luminance of 13553 cd/m 2 , maximum current efficiency of 5.87 cd/A and maximum power efficiency of 3.44 lm/W, respectively. The results provide a new way to deposit HIL based on solution-processed metal oxide in efficient OLED. [ABSTRACT FROM AUTHOR]

A model is presented for predicting the evaporation behavior of liquid droplets containing nano-sized insoluble particles. The model is constructed based on, and supported by, the existing experimental result. Of particular interest are the evolution of droplet size, and evaporation rate constant prior to the shell formation (also called the first drying or evaporation stage), when the particles forms a compact shell at the droplet surface. As the droplet evaporation proceeds, increasingly more particles are “included” on its surface, reducing the effective liquid surface area for evaporation causing deviation from the classical d 2 -law for pure fluid droplet evaporation. Peclet number ( Pe ), a non-dimensional ratio of particle diffusion time to the droplet lifetime, and initial particle concentration ( Y vo ) are shown to play a role in the evaporation behavior prior to shell formation. The model predicts that: (1) the deviation from the classical d 2 -law is increasingly significant with increased Pe and Y vo ; (2) the time to shell formation decreases, and shell diameter increases, with increased Pe and initial particle concentration ( Y vo ). As a consequence, Y vo · Pe < 1.8 is necessary for the first stage to exist at all. Within the limiting value, the combination of larger Pe and smaller Y vo produces larger hollow shells with low densities. For Y vo · Pe > 1.8 the shell forms instantly and evaporation occurs after liquid diffuses through, and wet, the shell. The effect of contact angle ( θ ) on the effective liquid surface area for evaporation is also discussed. [ABSTRACT FROM AUTHOR]

The transcription factor AP-1 plays an important role in inflammation and cell survival. Using a dual-luciferase reporter assay system and a library of 940 candidate human secretory protein cDNA clones, we identified that CGREF1 can inhibit the transcriptional activity of AP-1. We demonstrated that CGREF1 is secreted via the classical secretory pathway through the ER-to-Golgi apparatus. Functional investigations revealed that overexpression of CGREF1 can significantly inhibit the phosphorylation of ERK and p38 MAPK, and suppress the proliferation of HEK293T and HCT116 cells. Conversely, specific siRNAs against CGREF1 can increase the transcriptional activity of AP-1. These results clearly indicated that CGREF1 is a novel secretory protein, and plays an important role in regulation of AP-1 transcriptional activity and cell proliferation. [ABSTRACT FROM AUTHOR]

The plant circadian clock is an internal timekeeper that coordinates biological processes with daily changes in the external environment. The transcript levels of clock genes, which oscillate to control circadian outputs, were examined during early seedling development in barley (Hordeum vulgare), a model for temperate cereal crops. Oscillations of clock gene transcript levels do not occur in barley seedlings grown in darkness or constant light but were observed with day-night cycles. A dark-to-light transition influenced transcript levels of some clock genes but triggered only weak oscillations of gene expression, whereas a light-to-dark transition triggered robust oscillations. Single light pulses of 6, 12 or 18 hours induced robust oscillations. The light-to-dark transition was the primary determinant of the timing of subsequent peaks of clock gene expression. After the light-to-dark transition the timing of peak transcript levels of clock gene also varied depending on the length of the preceding light pulse. Thus, a single photoperiod can trigger initiation of photoperiod-dependent circadian rhythms in barley seedlings. Photoperiod-specific rhythms of clock gene expression were observed in two week old barley plants. Changing the timing of dusk altered clock gene expression patterns within a single day, showing that alteration of circadian oscillator behaviour is amongst the most rapid molecular responses to changing photoperiod in barley. A barley EARLY FLOWERING3 mutant, which exhibits rapid photoperiod–insensitive flowering behaviour, does not establish clock rhythms in response to a single photoperiod. The data presented show that dawn and dusk cues are important signals for setting the state of the circadian oscillator during early development of barley and that the circadian oscillator of barley exhibits photoperiod-dependent oscillation states. [ABSTRACT FROM AUTHOR]

Metabolism plays a critical role in cancer. OLR1 has been implicated in cardiovascular and metabolic disorders, while its association with tumorigenesis and tumor immunity remains poorly defined in the literature. We conducted comprehensive pan-cancer analyses based on the TCGA database to examine OLR1 expression and its prognostic implications. Correlations between OLR1 expression level and tumor immunity and immunotherapy were investigated by immune infiltration, enrichment, and TIDE analysis methods. Immunohistochemistry detected OLR1 expression in HNSCC. We used the GSEA method to explore the potential signaling pathways in which OLR1 is involved, and a correlation analysis to investigate the relationships between OLR1 and epithelial–mesenchymal transition (EMT) and cuproptosis. In addition, the effects of OLR1 knockdown on the EMT process, invasion, stemness, and cuproptosis of HNSCC cells were examined by scratch, Transwell, CCK8, sphere formation, and flow cytometry, while changes in related proteins were detected using the immunoblotting method. OLR1 is highly expressed in most cancers, and it is associated with patient prognosis. OLR1 expression positively correlates with immunosuppressive cell infiltration and immune checkpoint molecules, while being negatively associated with effector T cells. Moreover, significant correlations are observed between OLR1 expression and tumor mutation burden (TMB) and microsatellite instability (MSI) in some cancers. In HNSCC, OLR1 expression is related to advanced clinicopathological factors and unfavorable outcomes. Patients with high OLR1 expression levels are prone to experience immune escape and benefit less from immune checkpoint inhibitor (ICI) therapy. Moreover, OLR1 expression may affect EMT, stemness, and cuproptosis resistance outcomes. OLR1 is an immune-related prognostic biomarker with potential as a prognostic indicator for immunotherapy, and it may also be involved in regulating the EMT process and cuproptosis in HNSCC. [ABSTRACT FROM AUTHOR]

Understanding of laser shock peening (LSP)-generated microstructural characteristics at the interfaces between hexagonal close-packed (HCP) and body-centered cubic (BCC) crystals and dislocation patterns could provide useful insights into designing the interface between both phases of dual- or multi- phase metallic materials, which is a key information for higher properties. Herein, with a severe plastic deformation process of LSP, a systematic work of the mechanism behind misfit dislocations at different grain size has been carried out. It demonstrates that, as the grain gradually is refined, extrusion and torsion of the lattice are important contributions to the modified d-spacing and quantity of misfit dislocation. Hence, the growth orientation and the style of bicrystal interface between HCP and BCC crystals are affected. Furthermore, the size effect of the LSP-generated dislocation pattern has a significant attribution to the stress of misfit dislocation originating from neighboring interfaces. • LSP-generated microstructural characteristics at HCP/BCC interfaces were observed. • The evolution of misfit dislocations based on the grain size effect was elaborated. • d-spacings of bonding planes were measured and the coherent interface was formed. • The relationship between misfit dislocations and dislocation patterns was determined. [ABSTRACT FROM AUTHOR]

Transcriptional activation of the VERNALIZATION1 gene mediates the acceleration of flowering by prolonged cold (vernalization) in temperate cereals. This study examined the earliest stages of the transcriptional response of VRN1 to low temperatures. Time-course analyses, using a sensitive quantitative PCR assay, showed that in sprouting barley seedlings VRN1 transcripts begin to accumulate within 24 hours of the onset of cold. The kinetics of the initial transcriptional response of VRN1 to cold was similar to the cold-induced genes DEHYDRIN5 (DHN5) and COLD REGULATED 14B (COR14B), but occurred at lower levels compared to cold acclimation genes or the response to longer cold treatments. Temperatures between 15 and –2 °C induced expression of VRN1 within 24 hours, with a maximal response observed between 2 and –2 °C. Transcriptional induction was also observed in undifferentiated callus cells. There were significant increases in histone acetylation levels at the VRN1 locus in response to 24-hour cold treatment. Sodium butyrate, a histone deacetylation inhibitor, triggered an increase in histone acetylation at VRN1 chromatin and elevated VRN1 transcript levels. The transcriptional response of VRN1 to short-term cold treatment was examined in near-isogenic lines that have different VRN1 genotypes, showing that an allele of the barley VRN1 gene with an insertion in the first intron and high basal expression levels has a reduced transcriptional response to short term cold treatment. This study suggests that low-temperature induction of VRN1 is a cellular response to cold triggered by the same mechanisms that mediate low-temperature induction of cold acclimation genes. [ABSTRACT FROM AUTHOR]

Abstract: The challenge of effectively removing high heat flux from microelectronic chips may hinder future advancements in the semiconductor industry. Spray cooling is a promising solution to dissipate high heat flux, but traditional sprays suffer from low cooling efficiency partly because of droplet rebound. Here we show that electrosprays provide highly efficient cooling by completely avoiding the droplet rebound, when the electrically charged droplets are pinned on the heated conducting surface by the electric image force. We demonstrate a cooling system consisting of microfabricated multiplexed electrosprays in the cone-jet mode generating electrically charged microdroplets that remove a heat flux of 96W/cm2 with a cooling efficiency reaching 97%. Scale-up considerations suggest that the electrospray approach is well suited for practical applications by increasing the level of multiplexing and by preserving the system compactness using microfabrication. [Copyright &y& Elsevier]

Many novel functional structures are now fabricated by controlled deposition as a maskless, bottom-up fabrication technique. These applications require rapid and precise deposition of minute amounts of solutions/suspensions or their ultimate particle products in predefined patterns. The electrospray is a promising alternative to the commonly used inkjet printing because it can easily handle highly viscous liquid, avoid high shear rates, and has low risk of clogging. We demonstrate a proof-of-concept digital electrospray. This system consists of a 61-nozzle array microfabricated in silicon and a 61-element digital extractor fabricated using flexible polyimide substrates. “Digital” refers to the state of each electrospray source that can be tuned either on or off independently and responsively. We showed a resolution of 675 μm and a response frequency up to 100 Hz. With similar design and industry standard fabrication procedures, it is feasible to scale up the system to O(1000) sources with spatial resolution better than 250 μm and a O(kHz) response frequency. The latter is controlled by the viscous damping time. [ABSTRACT FROM AUTHOR]

Abstract: We developed a well-controlled method to generate PLGA microparticles of different morphologies using the electrospray drying route. By judiciously selecting polymer molecular weight, concentration, and solution flow rate, we can control the order in which polymer entanglements and Coulomb fission occur in the droplets and their relative importance, and subsequently govern the morphology of the resulting polymer particles. We show that spherical, monodisperse particles are generated when sufficiently strong polymer entanglements set in the evaporating droplets before they undergo any Coulomb fission. On the other hand, tailed and elongated particles are obtained if the Coulomb fission occurs first and if the droplets/particles are sufficiently evaporated to freeze in their irregular shape. Strictly spherical particles are unachievable for polymer solutions below a critical concentration, because the onset of Coulomb fission always sets in prior to the development of a sufficiently entangled polymer network. An extension of a simple model, originally used to determine the onset of electrospinning of polymer solutions, adequately predicts when non-spherical particles are produced. We conclude by demonstrating the scale-up of this approach to the synthesis of polymer particles using a compact, microfabricated, multiplexed electrospray system, which would make it suitable for practical applications. [Copyright &y& Elsevier]

Abstract: Widespread application of the cone-jet electrospray has been hampered by the low flow rate at which the spray is dispersed, despite the unique ability of this device to disperse quasi-monodispersed particles over a phenomenal size range. Compact multiplexing, that is, with a high number of sources per unit area, is indispensable for dramatically increasing the throughput and reducing the cost per electrospray source. We demonstrate the successful operation of multiplexed electrospray systems with an unprecedented packing density of up to 11,547sources/cm2. The devices were fabricated and operated by implementing three criteria: (a) the extractor electrode configuration should be used to localize the electric field; (b) the viscous pressure drop acting on the liquid should dominate with respect to the electrostatic pulling force by the electric field; and (c) the electric field “driving” the droplets between the extractor electrode and the collector should be sufficiently intense to avoid reversal of the droplet motion near the extractor (satellite trapping). All devices showed excellent droplet size uniformity across the entire spray region, which indicates effective decoupling of the electrospray sources even for closely packed nozzles. The experimental results show that these design criteria provide effective and reliable guidelines for the successful design and operation of multiplexed devices from first principles, that is, based only on knowledge of the suitability of a liquid for electrospray dispersion and of the critical liquid properties such as surface tension, viscosity and electric conductivity. As a result, the design of these devices for a given application is achievable without costly trial-and-error microfabrication trials. This development opens the door for applications requiring flows from multiplexing 106–107 individual electrospray sources from industry-standard 12-in silicon wafers. [Copyright &y& Elsevier]

Abstract: The transcription factor NF-κB plays an important role in inflammation and cell survival. Here, we report the functional characterization of URP2SF (UNC-112 related protein 2 short form), which is a novel protein containing FERM and PH domains. The protein is conserved in evolution across different species. Northern blot and RT-PCR analysis revealed that the expression of URP2SF appeared to be primarily confined to immune system. URP2SF protein localized to the whole cell. Over-expression of URP2SF strongly repressed NF-κB activity in the absence or presence of NF-κB stimulus. Importantly, URP2SF over-expression also induced cell apoptosis. Furthermore, suppression of URP2SF expression by small interference RNA significantly activated the NF-κB reporter gene activities, as well as attenuated TNF-α induced apoptosis. Therefore, our data show for the first time that URP2SF may act as a transcriptional repressor in NF-κB signaling pathway and regulate cell apoptotic pathway. [Copyright &y& Elsevier]

Abstract: The effect of the space charge of the homopolarly charged droplets in a system of multiplexed electrosprays is investigated. The system consists of a microfabricated liquid distributor with multiple electrospray sources held at a high voltage, a nearby extractor electrode plate held at an intermediate voltage, and a grounded electrode further downstream. The system is very compact, with a spatial density as large as . Experimentally, we observed that the system performance was limited by the occurrence of path reversal of the satellite droplets, accumulating on the extractor electrode, flooding it and ultimately causing the electrospray to cease operation. To prevent this phenomenon, hereafter referred to as satellite trapping, and “sweep” the satellites downstream, the driving field between the extractor electrode and the ground must be increased. The system behavior was modeled by a simple line-of-charge approximation, which was validated by a more detailed Lagrangian model and by experiments on an individual electrospray. Subsequently, the line-of-charge model was extended to the multiplexed system yielding a satisfactory comparison between the computed minimum driving field that is necessary to prevent satellite path reversal and experimental values. Additional analytical approximations of the multilines-of-charge model yielded a scaling law showing the dependence of the space charge on: (i) the primary droplet residence time, (ii) the current emitted per unit area, and (iii) a dimensionless parameter, , that is the ratio of the distance between the extractor electrode and the ground electrode to the distance between neighboring nozzles. As a result, guidelines for the design of multiplexed electrosprays are established on a fundamental basis, without the need for costly and empirical microfabrication prototyping. [Copyright &y& Elsevier]

Abstract: The development, fabrication, and testing of a compact multiplexed system of electrosprays are presented with the dual goal of increasing by orders of magnitude the liquid flow rate to be dispersed and of retaining the quasi-monodispersity of the generated droplets. The system was microfabricated as an array of nozzles etched in silicon, with a density of 250sources/cm2. Although the operation of a single electrospray is rather forgiving with respect to the electrode geometry, successful performance of the multiplexed system is critically dependent on a careful selection of the electrode configuration, which in the present work entails an extractor electrode mounted at a distance from the spray sources that is comparable to the distance between sources (on the order of 0.5mm). The electrode has the dual function of limiting electric field cross-talk between neighboring sources and minimizing space charge feedback from the spray cloud. Measurements of current and droplet size as a function of flow rate and of droplet size distribution using ethanol demonstrated that the system may be optimized to produce uniform droplets simultaneously from all parallelized electrosprays, each one operating as an isolated spray in the quasi-monodisperse cone-jet mode. Ease of operation and uniformity in size from spray to spray require strategies to increase the pressure drop in the liquid flow path and/or to uniformize the electric field at the spray sources. [Copyright &y& Elsevier]

Abstract: The electrospray of conducting liquids operated in the cone-jet mode is well known to have the unique ability of generating droplets uniform in size over a phenomenal range of sizes depending primarily on the liquid flow rate and physical properties. Since there is a monotonic dependence of size on flow rate, the liquid flow rates that can be dispersed are modest if the goal is to produce very small (below a few micrometers in diameter) droplets. Yet, this is precisely the application niche for which few, if any, atomization alternatives are available. Multiplexing the spray source is indispensable for the electrospray capabilities to have an impact in high-value-added applications. We report here on a novel approach to multiplexing based on a well-known, but hitherto unexploited, regime of operation, the multi-jet mode. Ordinarily, such a mode is rather unsteady and the range of flow rates at which appreciable multiplexing is achieved is small. However, if the multi-jet mode is anchored by some sharp features (e.g., grooves, ridges, etc.) machined at the outlet of the atomizer, to intensify the electric field at discrete points around its perimeter, then the cone-jets are simultaneously anchored at these features and a stable mode of operation is identified over several hundreds of volts and a broad range of flow rates. Most importantly, so long as the machining is accurately reproduced from point to point, droplets generated do not vary significantly in size from spray to spray. As a result, a compact, inexpensive and versatile multiplexing system is realized without sacrificing droplet monodispersity. [Copyright &y& Elsevier]

Electronic thin films play a ubiquitous role in microelectronic devices and especially hold great promise for flexible electronics, energy conversion and storage, and biomedical applications. Their characterizations, including ultra‐thin, large‐scale dimensions, stretchability, and conformal ability to curved or 3D structures, present new challenges for thin film fabrication based on the solution method. Electrospray deposition emerges as a feasible method for fabricating large‐area, flexible, and curved films. It offers many advantages such as material adaptability, controlled atomization, tunable film morphology, and shape retention on complex substrates. These advantages make it a key method for fabricating high‐performance films on large‐area, 3D surfaces. This work presents a comprehensive review of the mechanisms, processes, applications, and equipment of electrospray deposition. First, the fundamental principles of electrospray deposition are introduced, focusing on the mechanisms and scaling laws of liquid atomization. Moreover, the control methods for electrospray modes, structures, and film morphology are discussed. These advanced control methods pave the way for the fabrication of smart skins, wearable devices, and energy conversion and storage components. Finally, this work introduces three types of electrospray deposition manufacturing equipment to illustrate the advantages of electrospray deposition for large‐area, and 3D surface manufacturing. [ABSTRACT FROM AUTHOR]

Electrohydrodynamic (EHD) printing enables large-area, ultra-high-resolution manufacturing across a broad range of ink viscosities, but inevitably encounters difficulties when printing on electrically insulating three-dimensional substrates due to unpredictable electric field and surface residual charges. To overcome these obstacles, a novel approach called plasma-induced electrohydrodynamic (PiE) printing has been proposed. PiE printing employs plasma to directly create a controllable local charge region directly on substrate surfaces, which triggers EHD ink ejection and mitigates the effect of residual charges. However, the underlying mechanisms of the jetting behavior with respect to printing parameters, such as the charge-induced electric field, remain unexplored. Here, we conduct a numerical investigation, based on the Taylor–Melcher leaky dielectric model and the level set method, on the jetting behavior of substrate surface charge-induced EHD printing. We first introduce the dynamics behavior throughout the entire printing process. Then, we carry out a comprehensive investigation on surface charge-induced EHD printing under four crucial parameters: the amount of preset surface charge, the radius of preset surface charge, the duration of preset surface charge, and liquid electrical conductivity. By analyzing the induced electric field, induced charge density, fluid velocity, jet diameters, and deposited droplet sizes obtained from the numerical results, we elucidate the influence of these parameters on the dynamic behavior, durations of jetting process, and printing quality. These findings offer valuable insights into surface charge-induced EHD jetting, advancing the understanding and optimization methods for this useful micro-/nano-manufacturing technology. [ABSTRACT FROM AUTHOR]

Top electrodes of organic photovoltaics (OPVs) are usually thermally evaporated in the vacuum, which is non‐continuous and time‐consuming and has been the bottleneck for the OPV fabrication process. Printable top electrodes that are free of vacuum, high temperature, and solvents will make OPVs more attractive. Low‐melting‐point alloys (LMPAs) are promising candidates for printable OPV electrodes thanks to the merits of matching work functions, high electron conductivity, high environment stability, and no need for post‐treatment. Here, LMPA electrodes are directly deposited on OPVs by simply falling a single LMPA droplet onto the substrate. The LMPA droplet spreads to form a thin film with a smooth interface intimately contacting the substrate. The electrode area can be tailored by adjusting the droplet diameter or the Weber number, which is the ratio of inertia to surface tension. The interface morphology is mainly affected by the contact temperature. The degree of oxidation and charges on the droplet can also influence the electrode area and interface morphology. OPVs with droplet‐impacted LMPA electrodes exhibit power conversion efficiencies of up to 16.17%. This work demonstrates the potential of single‐droplet impact deposition as a simple method for printing OPV electrodes for scalable manufacturing. [ABSTRACT FROM AUTHOR]

Background: Metal implants may affect the image quality, iodine concentration (IC), and CT Hounsfield unit (HU) quantification accuracy. Purpose: To investigate the quantitative accuracy of IC and HU from dual-layer spectral detector (DLCT) in the presence of metal artifacts. Material and Methods: An experimental cylindrical phantom containing eight iodine inserts and two metal inserts was designed. The phantom underwent scanning at three radiation dose levels and two tube voltage settings. A set of conventional images (CIs), virtual monoenergetic images (VMIs), and iodine concentration maps (ICMs) were generated and measured for all the eight iodine inserts. Quantitative indicators of mean absolute percentage error (MAPE), artifact index (AI), contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and standard deviation (SD) on CIs and VMIs were calculated for IC and HU. Subjective score evaluation was also conducted. Results: The MAPEiodine values of all regions of interest across different scanning configurations were all <5%. Almost all APEiodine values were <5%, indicating that metal artifacts had little impact on IC measurements. When the tube voltage was fixed, the SD value of attenuation decreased with the increase of the tube current; this is also true when the tube current was fixed. The middle energy reconstructions seemed to give a good balance between reducing artifacts and improving contrast. Conclusion: VMIs from DLCT can reduce metal artifacts, the accuracy of IC quantification is not sensitive to imaging parameters. In summary, metal implants exhibit minimal impact on image quality and IC quantification accuracy in reconstructed images from DLCT. [ABSTRACT FROM AUTHOR]

Organic semiconductor (OSC) films fabricated by meniscus‐guided coating (MGC) methods are suitable for cost‐effective and flexible electronics. However, achieving crystalline thin films by MGC methods is still challenging because the nucleation and crystal growth processes are influenced by the intertwined interactions among solvent evaporation, stochastic nucleation, and the fluid flow instabilities. Herein, a novel flexible fountain pen with active ink supply is designed and used to print OSCs. This direct‐write method allows the flexible pen tip to contact the substrate, maintaining a robust meniscus by eliminating the gap found in conventional MGCs. An in situ optical microscopy observation system shows that the precursor film plays a critical role on the crystallization and the formation of coffee rings and dendrites. The computational fluid dynamics simulations demonstrate that the microstructure of the pen promotes extensional flows, facilitating mass transport and crystal alignment. Highly‐aligned ribbon‐shaped crystals of a small organic molecule (TIPS‐pentacene), as well as a semiconducting polymer (N2200) with highly‐ordered orientations, have been successfully printed by the flexible fountain pen. Organic field‐effect transistors based on the flexible pen printed OSCs exhibit high performances and strong anisotropic mobility. In addition, the flexible fountain pen is expandable for printing multiple lines or large‐area films. [ABSTRACT FROM AUTHOR]

This study presents an innovative electrostatic spray flame synthesis (ESFS) reactor that combines the advantages of electrostatic spray and flame synthesis for precise spray control and efficient single-step continuous synthesis. To overcome the limitations of conventional ESFS systems, which often suffer from low atomized precursor flux, we successfully demonstrated a high-flux disk electrostatic atomizer coupled low-swirl flame reactor, achieving a precursor flux of up to 30 ml/h about 30 times higher than that of typical ESFS devices. The atomized precursor being rapidly carried away from the burner is undergoing high-temperature pyrolysis and particle formation through lifted premixed turbulent flames. The ESFS system provides extensive control over parameters such as flame temperature, equivalence ratio, residence time, initial droplet sizes, and precursor concentrations. For illustrative purposes, the ESFS system was utilized to synthesize silica nanoparticles, demonstrating the capability of synthesizing nanoparticles with various properties. By manipulating the collection position and height, the particle size has made a substantial leap from the nanoscale to the micrometer level. This remarkable achievement underscores the system's enormous potential for precise particle size regulation and one-step synthesis of complex structured thin films. [ABSTRACT FROM AUTHOR]

Recently, the COVID-19 virus pandemic has led to many studies on the airborne transmission of expiratory droplets. While limited experiments and on-site measurements offer qualitative indication of potential virus spread rates and the level of transmission risk, the quantitative understanding and mechanistic insights also indispensably come from careful theoretical modeling and numerical simulation efforts around which a surge of research papers has emerged. However, due to the highly interdisciplinary nature of the topic, numerical simulations of the airborne spread of expiratory droplets face serious challenges. It is essential to examine the assumptions and simplifications made in the existing modeling and simulations, which will be reviewed carefully here to better advance the fidelity of numerical results when compared to the reality. So far, existing review papers have focused on discussing the simulation results without questioning or comparing the model assumptions. This review paper focuses instead on the details of the model simplifications used in the numerical methods and how to properly incorporate important processes associated with respiratory droplet transmission. Specifically, the critical issues reviewed here include modeling of the respiratory droplet evaporation, droplet size distribution, and time-dependent velocity profile of air exhaled from coughing and sneezing. According to the literature review, another problem in numerical simulations is that the virus decay rate and suspended viable viral dose are often not incorporated; therefore here, empirical relationships for the bioactivity of coronavirus are presented. It is hoped that this paper can assist researchers to significantly improve their model fidelity when simulating respiratory droplet transmission. [ABSTRACT FROM AUTHOR]

In contrast to the existing research on the liquid jet colliding with a physical target to produce a single type of liquid sheet or bell, we used an opposing gas jet target to generate a series of diverse shapes of axisymmetric liquid films. Specifically, we experimentally investigated the outcome of a 0.4-mm diameter water jet impinging on an opposing gas jet of 0.3 mm initial diameter. Five different axisymmetric film shapes are identified for the experimental parameters explored in this work, and the momentum flux ratio (X) of the gas jet to the water jet is the dictating factor for the exact film shape: (i) X = 0: smooth bells that share the same shape and profile model with classic water bells of a liquid jet impacting a solid target. (ii) 0 < X < 0.4: crumpled bells being lifted off from the gas nozzle by a thin layer of squeezing gas flow that is quantifiable by the lubrication model. (iii) 0.4 < X < 0.9: transient bells with mildly wrinkled surfaces that undergo periodic cycles from closure to bursting at a gas Reynolds number of ∼2400. (iv) 0.9 < X < 1.4: turbulent parachutes with curved and rough shapes. (v) X > 1.4: turbulent sheets that are flattened and atomized by the relatively strong gas stream. This work demonstrated that an opposing gas jet is a simple yet versatile approach to achieving a rich collection of phenomena by diverting the liquid jet momentum in multiple ways. This investigation aims to explore and rationale the rich phenomenology of water bells resulting from the impingement of a water jet on a gaseous jet target. [ABSTRACT FROM AUTHOR]

The performance of organic solar cells is sensitive to the film thickness and the uniformity of the donor and acceptor distribution in the photoactive layer. Especially, in the quasi‐planar heterojunction fabricated by layer‐by‐layer process, the donor and acceptor materials may be non‐homogeneously distributed across the entire photoactive layer. Visualization of the spatial distributions of donor and acceptor components sheds light on the relationship between nanostructures and device performances. Based on the distinct infrared absorption characteristics of the organic donor and acceptor, a quasi‐monochromatic light transmittance (QMLT) technique is proposed to quantify the donor and/or acceptor thickness in the photoactive layer blend across the entire device area with nanometer precision. The variation in thickness of donor and acceptor can be clearly and separately revealed. Accordingly, the impacts of spin coating techniques (such as dynamic or static dispensing, and on‐center or off‐center spin coating), as well as solvent choices, on film morphology and device performance can be correlated by the noncontact, nondestructive, and convenient QMLT method. [ABSTRACT FROM AUTHOR]

T reg plays a pivotal role in the suppression of Th2 cell and the maintenance of immune homeostasis. The precise molecular mechanism underlying the disruption of T reg suppression of Th2 cell and the promotion of Th2 type inflammation in allergic diseases remains elusive. This study aims to investigate the molecular mechanism underlying quantitative and functional changes of T reg in AD. The molecular mechanism was investigated using flow cytometry, mRNA sequencing, co-culture experiments, co-immunoprecipitation, chromatin immunoprecipitation, and bisulfite sequencing in vitro or in AD mice model and patients with AD. Increased proportion of T reg was detected in mild and moderate AD. Conversely, characteristic decrease in both the number and CTLA-4 expression of T reg was relevant to serum IL-4 level in severe AD patients, which was verified under a high concentration of IL-4 treatment in vitro. The underlying mechanism is that IL-4/pSTAT6 pathway recruits DNMT1 and HDAC2 to inhibit transcriptional regulation of Foxp3 and CTLA-4 loci. High level of IL-4 impaired the suppression of T reg against Th2 cell differentiation mediated by CTLA-4, and blockade of IL-4Rα signaling in T reg restored T reg number and suppression of Th2 cell in AD model mice and patients with AD. The number of T reg is relevant to stratification of severity and serum IL-4 level in patients with AD. Abnormal high level of IL-4 epigenetically triggers a decrease in both the number and CTLA-4 expression of T reg. The reduced expression of CTLA-4 on T reg induced by IL-4 impairs suppression of Th2 cell differentiation. • The number of T reg is relevant to stratification of severity and serum IL-4 level in patients with AD. • High level of IL-4 epigenetically triggers a decrease in both the number and CTLA-4 expression of T reg in severe AD. • IL-4-induced reduction in both number and CTLA-4 expression of T reg impaired CTLA-4-mediated suppression of Th2 cell. • Blockade of IL-4Rα signaling in T reg restores T reg expression and its suppression of Th2 type inflammation in severe AD. [ABSTRACT FROM AUTHOR]

Cullin-RING E3 ubiquitin ligase (CRL) family members play critical roles in numerous biological processes and diseases including cancer and Alzheimer's disease. Oligomerization of CRLs has been reported to be crucial for the regulation of their activities. However, the structural basis for its regulation and mechanism of its oligomerization are not fully known. Here, we present cryo-EM structures of oligomeric CRL2FEM1B in its unneddylated state, neddylated state in complex with BEX2 as well as neddylated state in complex with FNIP1/FLCN. These structures reveal that asymmetric dimerization of N8-CRL2FEM1B is critical for the ubiquitylation of BEX2 while FNIP1/FLCN is ubiquitylated by monomeric CRL2FEM1B. Our data present an example of the asymmetric homo-dimerization of CRL. Taken together, this study sheds light on the ubiquitylation strategy of oligomeric CRL2FEM1B according to substrates with different scales. Synopsis: The structural basis and biological importance of cullin-RING ubiquitin ligase (CRL) oligomerization remain largely unclear. Here, high-resolution cryo-EM and biochemical data reveal that oligomerization of CRL2FEM1B serves as a structural foundation for accommodating substrates of varying sizes. Cryo-EM structures show oligomeric CRL2FEM1B in its unneddylated state and as neddylated form in complex with different substrates. RBX1 and CUL2 participate in the assembly of CRL2FEM1B oligomers. Asymmetric homo-dimerization allows CRL2FEM1B to ubiquitinate substrates with small scales, such as BEX2. Large substrates such as FNIP1/FLCN complexes are ubiquitinated by monomeric CRL2FEM1B. Asymmetric homo-dimerization allows ubiquitination of substrates with small scales, while large substrates are targeted by monomeric CRL2-FEM1B E3. [ABSTRACT FROM AUTHOR]

The dynamic response of a micrometer-sized gallium–indium (Ga-In) jet in nitrogen subjected to intense Neodymium-doped Yttrium Aluminum Garnet (Nd: YAG) laser pulses with energy ranging from 0.35 to 5.0 mJ per pulse is investigated experimentally. The rapid deformation of the jet was visualized using timed-delayed stroboscopic shadowgraphy. The laser pulse disrupts the jet to form a gap, and the length of the gap grows according to a logarithm relationship with respect to the dimensionless time normalized a characteristic timescale τ, which is determined by the pulse energy Ep. The ablation impulse bends and flattens the jet into a thin curved film that resembles a wind-blown sail. The area of the sail increases with t6/5Ep13/15, where t is time. The sail eventually breaks up into fine mist. Additionally, we found that the laser-blast-induced initial bending velocity of the jet could be predicted using the semi-empirical laser-ablated propulsion model for an In-Sn droplet of tens of micrometers. [ABSTRACT FROM AUTHOR]

Objective: To assess the feasibility of spectral CT–derived extracellular volume (ECV) for differentiating aldosterone-producing nodules (APN) from nonfunctioning adrenal nodules (NFN). Methods: Sixty-nine patients with biochemically and histologically confirmed unilateral APN (34) and NFN (35) as well as 23 patients with bilateral APN (19) and NFN (27) confirmed biochemically and by adrenal vein sampling (AVS) were enrolled in this retrospective study from October 2020 to April 2022. All patients underwent contrast-enhanced spectral CT of the adrenal glands with a 10-min delayed phase. The haematocrit level was measured within 2 days of CT. An iodine density map was derived from the delayed CT. The ECV fractions of the APN and NFN were calculated and compared in the test cohort of 69 patients with unilateral adrenal nodules. The optimal cut-off value was determined to evaluate the diagnostic efficacy of the ECV fraction for differentiating APN from NFN in the validation cohort of 23 patients with bilateral adrenal nodules. Results: The ECV fractions of the APN (11.17 ± 4.57%) were significantly lower (p < 0.001) than that of the NFN (24.79 ± 6.01%) in the test cohort. At cut-off ECV value of 17.16%, the optimal area under the receiver operating characteristic curve was 0.974 (95% confidence interval: 0.942–1) with 91.4% sensitivity, 93.9% specificity, and 92.8% accuracy in the test cohort and 89.5% sensitivity, 96.3% specificity, and 93.5% accuracy in the validation cohort for differentiating APN from NFN. Conclusion: The spectral CT–derived ECV fraction can differentiate APN from NFN with high diagnostic performance. Clinical relevance statement: Spectral CT–derived extracellular volume fraction could accurately differentiate between adrenal aldosterone-producing nodules and nonfunctioning nodules. It might serve as a noninvasive alternative to adrenal vein sampling in primary aldosteronism patients with bilateral adrenal nodules. Key Points: • Conventional CT cannot differentiate aldosterone-producing adrenal nodules from nonfunctioning nodules. • Extracellular volume of adrenal aldosterone-producing nodules was significantly lower than that of nonfunctioning nodules and normal adrenal glands. It can accurately differentiate between aldosterone-producing and nonfunctioning adrenal nodules. • Extracellular volume may be a novel, noninvasive biomarker alternative to adrenal vein sampling for determining the functional status of bilateral adrenal nodules in patients with primary aldosteronism. [ABSTRACT FROM AUTHOR]

Colloidal PbS quantum dots (QDs) have attracted tremendous attention in near‐infrared photodetection for their superior optoelectronic properties. However, appropriate fabrication methods remain a challenge for scalable and high performance PbS QD photodetectors. Herein, a flexible microcomb printing (FMCP) technique is first introduced to fabricate PbS QD photoconductors without a layer‐by‐layer ligand exchange technique, and the detectors demonstrate a responsivity of 2.1 A W−1. A computational fluid dynamics model is built to simulate the flow field distribution and analyze the relationship between the key parameters of FMCP and QD film morphology. The QD ink flow field at the tip of the microcomb exhibits high shear rates that lead to a better crystallization configuration for solid QD films formation, which is verified by Grazing‐incidence small and wide‐angle X‐ray scattering. Moreover, the relationship between the intrinsic nature of the QD ink (viscosity and surface tension), substrate temperature, and printing speed are systematically analyzed to experimentally achieve high performance QD films. Benefiting from the good crystallization configuration, FMCP‐printed photodetectors using the direct PbS QD ink without ligand exchange show high responsivities. The results indicate that FMCP is a promising method for scalable and high‐performance PbS QD photodetectors. [ABSTRACT FROM AUTHOR]

The Coronavirus Disease 2019 pandemic has become an unprecedented global challenge for public health and the economy. As with other respiratory viruses, coronavirus is easily spread through breathing droplets, particularly in poorly ventilated or crowded indoor environments. Therefore, understanding how indoor environmental conditions affect virus transmission is crucial for taking appropriate precautions. In this study, the effects of different natural wind-driven ventilation conditions and ambient relative humidities (RHs) on the cough droplet transmission in an indoor environment are investigated using the large eddy simulation approach with Lagrangian droplet tracking. The simulations show that the velocity and temperature of droplets significantly decrease in a short time after ejection. This feature for droplet velocity and temperature is more pronounced at smaller inlet wind speed (Vin) and larger Vin or lower RH, respectively. Wind-driven ventilation plays a crucial role in affecting the horizontal transmission distance of cough droplets. Under strong natural ventilation conditions (Vin = 4.17 m/s), cough droplets can spread more than 4 m within 1 s, whereas they can only travel within 2 m under weak ventilation with Vin = 0.05 m/s. The results confirm that the social distancing of 2 m is insufficient, while revealing that proper ventilation control can significantly remove virus-laden droplets from indoor air. We believe that there is no absolute safe social distancing because the droplet transmission and dispersion are mainly controlled by the local environmental conditions, and for safety, we recommend wearing a face mask and maintaining good indoor ventilation to reduce the release of potentially virus-laden droplets into the air. [ABSTRACT FROM AUTHOR]

Laser spark ignition of methane diffusion flames, in the stagnation region in counter-flow configuration, is studied with a range of transport properties achieved by using different levels of inert dilution with helium and argon as diluents in the fuel stream. The effects of transport properties on ignition strain rate and ignition delay time are investigated and possible effects of effective Lewis number ( Le e ) are also discussed and compared with those for flame extinction. The following results are obtained: (1) The role of Le e on the critical global strain rate, beyond which ignition is not possible, is qualitatively similar to that on the extinction strain rate. That is, with the same level of dilution, the inert diluent with smaller Le e (therefore relatively smaller heat loss rate) yields larger critical global strain rate. (2) For successful ignition, the ignition delay time decreases with increasing level of helium dilution, while the opposite is true with argon dilution – the experimental results correlated with the calculated results of the diffusion times with these two inert diluents, suggesting that the successful ignition and the ignition delay time is limited by the thermal diffusion time across the flammable layer in the counter-flow region, rather than resulting from the Lewis number effect. [ABSTRACT FROM AUTHOR]

The reliability of the long-term operation of multicrystalline silicon (mc-Si) modules is very important due to its large market share. However, mc-Si modules show significant degradation over time, when exposed to sunlight. In this paper, the changes in the electrical characteristics, before and after ultraviolet-induced degradation (UV-ID), were monitored in mc-Si passivated-emitter–rear-contact (PERC) cells. We first demonstrate that UV light causes the formation of defects in the bulk of solar cells, rather than destroying the surface passivation. An advanced hydrogen passivation process is performed to inhibit the bulk degradation and it is found that UV-ID is effectively suppressed on either the cell or the module. [ABSTRACT FROM AUTHOR]

All printing of organic photovoltaics (OPVs) including the top electrode is highly desirable for achieving cost‐effective, high‐throughput, and large‐area photovoltaic manufacturing. Here, the printing of a low‐melting‐point alloy as top electrodes in OPVs via blade coating is investigated. The Field's metal (FM) with the melting point of 62 °C is adopted for the top electrodes, because FM can be printed under moderate temperatures without harming the active layers while remaining solid state under solar irradiation. The correlations between the processing parameters and properties of the blade‐coated electrodes are elucidated. OPVs based on the D18:Y6 active layer and blade‐coated FM electrodes achieve a highest power conversion efficiency of 17.28%. The OPVs with FM‐electrode demonstrate much higher thermal stability than that of the Ag‐electrode devices. All‐printed OPVs, in which the FM electrode is blade coated and the other layers are prepared by flexible micro‐comb printing, exhibit an efficiency of 16.07%. The results represent the records of evaporation‐free and all‐printed OPVs, demonstrating that printing FM as OPV electrodes is a cost‐effective and time‐saving strategy to substitute the vacuum‐evaporated metals, as well as a feasible route toward high‐performance all‐printed OPVs. [ABSTRACT FROM AUTHOR]

Depositing all functional layers (including the top electrode) with spray methods is highly desirable and challenging for the eventual commercialization of organic solar cells (OSCs). This work addresses two key challenges toward fully‐sprayed OSCs: i) the printing of a high‐quality photoactive layer free of coffee rings and ii) the spray of the top electrode without the need of evaporation nor solvents. To eliminate coffee rings caused by individual droplets, the photoactive layer is deposited by electrospray on the cooled substrate. The reduced temperature slows down the solvent evaporation, promotes merging of individual droplets, and suppresses the formation of coffee rings. By optimizing the drying temperature, homogeneous films without coffee rings are obtained. The improved active‐layer morphology facilitates charge transport and reduces recombination. The device prepared by the coldplate‐assisted electrospray reaches a power conversion efficiency (PCE) of 17.13%. In addition, an alloy with the melting point of 62 °C is spray‐printed as the top electrode using an airbrush. The spray process is optimized by the trade‐off between the coverage rate and the film thickness. OSCs with the alloy electrode achieve the highest PCE of 16.26%. The fully‐sprayed OSCs exhibit PCEs up to 15.09%, demonstrating a viable route toward fully‐sprayed OSCs with high‐performance. [ABSTRACT FROM AUTHOR]

Air cushioning and bubble entrapment are common phenomena observed during low-velocity droplet impact on solid or fluid surfaces, whereby a thin layer of air mediates the lubrication pressure. Previously, it is found that both charging droplets and the application of external electric fields can eliminate air cushioning and bubble entrapment. In this study, we numerically investigate the air cushioning and bubble entrapment in the charged droplet impacting onto a solid surface under external electric fields. It is found that the presence of net charge has a field enhancement effect on polarized charges on the same side while weakening the electric field of polarized charges on the opposite side, which can be linearly superimposed in the atmospheric environment. Based on the mirror charge model, the scaling law of the electric field threshold required for the impact of charged droplets without air cushioning or bubble entrapment is given. A fitting function based on the scaling law shows a good agreement with the phase diagram of a charged droplet impact modes under electric fields. These findings offer valuable insight for applications that rely on charged droplets' impact under electric fields, such as electrohydrodynamic printing and spray coating, to mitigate the negative impact of air cushioning or bubble entrapment. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the influence of various factors on CT attenuation values (HUs) of acute and old fracture vertebra, and to determine the efficacy of HU differences (△HUs) in the differentiation of the two type of fractures. Materials and Methods: A total of 113 acute and 71 old fracture vertebrae confirmed by MRI were included. Four HUs measured at the mid-sagittal, upper 1/3 axial, mid-axial, and lower 1/3 axial planes of each vertebra were obtained. The △HUs between fracture vertebra and its control counterpart was calculated. Receiver operating characteristic (ROC) curve analysis was used and the areas under the ROC curve (AUC) were calculated to evaluate the efficacy of HUs and △HUs. To evaluate the effect of height reduction, region, age and gender on HUs and △HUs, one-way analysis of variance, Pearson correlation analysis and t-test were used. Results: The HUs and △HUs at the upper 1/3 axial plane achieved the highest AUCs of 0.801 and 0.839, respectively. The HUs decreased gradually from Thoracic to Lumbar in control group of acute fracture. While no significant differences were found in the HUs among the 3 localizations in both fracture groups (all P > 0.05). The HUs were negatively correlated with age in all groups. The HUs of male were significantly higher than female patients in all groups (all P < 0.05). While △HU was not significantly different between males and females (all P > 0.05). Conclusion: The vertebral HUs at the upper 1/3 axial plane are more likely to identify acute fractures. △HUs were beneficial in eliminating interfering factors. [ABSTRACT FROM AUTHOR]

Theanine, a tea plant-specific non-proteinogenic amino acid, is the most abundant free amino acid in tea leaves. It is also one of the most important quality components of tea because it endows the "umami" taste, relaxation-promoting, and many other health benefits of tea infusion. Its content in tea leaves is directly correlated with the quality and price of green tea. Theanine biosynthesis primarily occurs in roots and is transported to new shoots in tea plants. Recently, great advances have been made in theanine metabolism and transport in tea plants. Along with the deciphering of the genomic sequences of tea plants, new genes in theanine metabolic pathway were discovered and functionally characterized. Theanine transporters were identified and were characterized on the affinity for: theanine, substrate specificity, spatiotemporal expression, and the role in theanine root-to-shoot transport. The mechanisms underlying the regulation of theanine accumulation by: cultivars, seasons, nutrients, and environmental factors are also being rapidly uncovered. Transcription factors were identified to be critical regulators of theanine biosynthesis. In this review, we summarize the progresses in theanine: biosynthesis, catabolism, and transport processes. We also discuss the future studies on theanine in tea plants, and application of the knowledge to crops to synthesize theanine to improve the health-promoting quality of non-tea crops. [ABSTRACT FROM AUTHOR]

Background: Although β-catenin signaling cascade is frequently altered in human cancers, targeting this pathway has not been approved for cancer treatment. Methods: High-throughput screening of an FDA-approved drug library was conducted to identify therapeutics that selectively inhibited the cells with activated β-catenin. Efficacy of iron chelator and mitochondrial inhibitor was evaluated for suppression of cell proliferation and tumorigenesis. Cellular chelatable iron levels were measured to gain insight into the potential vulnerability of β-catenin-activated cells to iron deprivation. Extracellular flux analysis of mitochondrial function was conducted to evaluate the downstream events of iron deprivation. Chromatin immunoprecipitation, real-time quantitative PCR and immunoblotting were performed to identify β-catenin targets. Depletion of iron-regulatory protein 2 (IRP2), a key regulator of cellular iron homeostasis, was carried out to elucidate its significance in β-catenin-activated cells. Online databases were analyzed for correlation between β-catenin activity and IRP2-TfR1 axis in human cancers. Results: Iron chelators were identified as selective inhibitors against β-catenin-activated cells. Deferoxamine mesylate, an iron chelator, preferentially repressed β-catenin-activated cell proliferation and tumor formation in mice. Mechanically, β-catenin stimulated the transcription of IRP2 to increase labile iron level. Depletion of IRP2-sequered iron impaired β-catenin-invigorated mitochondrial function. Moreover, mitochondrial inhibitor S-Gboxin selectively reduced β-catenin-associated cell viability and tumor formation. Conclusions: β-catenin/IRP2/iron stimulation of mitochondrial energetics is targetable vulnerability of β-catenin-potentiated cancer. [ABSTRACT FROM AUTHOR]