Photomolecular effect: Visible light interaction with air-water interface.

Although water is almost transparent to visible light, we demonstrate that the air-water interface interacts strongly with visible light via what we hypothesize as the photomolecular effect. In this effect, transverse-magnetic polarized photons cleave off water clusters from the air-water interface. We use 14 different experiments to demonstrate the existence of this effect and its dependence on the wavelength, incident angle, and polarization of visible light. We further demonstrate that visible light heats up thin fogs, suggesting that this process can impact weather, climate, and the earth's water cycle and that it provides a mechanism to resolve the long-standing puzzle of larger measured clouds absorption to solar radiation than theory could predict based on bulk water optical constants. Our study suggests that the photomolecular effect should happen widely in nature, from clouds to fogs, ocean to soil surfaces, and plant transpiration and can also lead to applications in energy and clean water.

Frequency-domain probe beam deflection method for measurement of thermal conductivity of materials on micron length scale.

Time-domain thermoreflectance and frequency-domain thermoreflectance (FDTR) have been widely used for non-contact measurement of anisotropic thermal conductivity of materials with high spatial resolution. However, the requirement of a high thermoreflectance coefficient restricts the choice of metal coating and laser wavelength. The accuracy of the measurement is often limited by the high sensitivity to the radii of the laser beams. We describe an alternative frequency-domain pump-probe technique based on probe beam deflection. The beam deflection is primarily caused by thermoelastic deformation of the sample surface, with a magnitude determined by the thermal expansion coefficient of the bulk material to measure. We derive an analytical solution to the coupled elasticity and heat diffusion equations for periodic heating of a multilayer sample with anisotropic elastic constants, thermal conductivity, and thermal expansion coefficients. In most cases, a simplified model can reliably describe the frequency dependence of the beam deflection signal without knowledge of the elastic constants and thermal expansion coefficients of the material. The magnitude of the probe beam deflection signal is larger than the maximum magnitude achievable by thermoreflectance detection of surface temperatures if the thermal expansion coefficient is greater than 5 × 10-6 K-1. The uncertainty propagated from laser beam radii is smaller than that in FDTR when using a large beam offset. We find a nearly perfect matching of the measured signal and model prediction, and measure thermal conductivities within 6% of accepted values for materials spanning the range of polymers to gold, 0.1-300 W/(m K).

Odd-even effect on the thermal conductivity of liquid crystalline epoxy resins.

Rapid developments in high-performance computing and high-power electronics are driving needs for highly thermal conductive polymers and their composites for encapsulants and interface materials. However, polymers typically have low thermal conductivities of ∼0.2 W/(m K). We studied the thermal conductivity of a series of epoxy resins cured by one diamine hardener and seven diepoxide monomers with different precise ethylene linker lengths (x = 2-8). We found pronounced odd-even effects of the ethylene linker length on the liquid crystalline order, mass density, and thermal conductivity. Epoxy resins with even x have liquid crystalline structure with the highest density of 1.44 g/cm3 and highest thermal conductivity of 1.0 W/(m K). Epoxy resins with odd x are amorphous with the lowest density of 1.10 g/cm3 and lowest thermal conductivity of 0.17 W/(m K). These findings indicate that controlling precise linker length in dense networks is a powerful route to molecular design of thermally conductive polymers.

Efficacy and safety of leflunomide combined with corticosteroids for the treatment of IgA nephropathy: a Meta-analysis of randomized controlled trials.

OBJECTIVE: We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of leflunomide combined with corticosteroids, compared with corticosteroids alone, for IgA nephropathy. MATERIALS AND METHODS: Studies were retrieved by searching of PubMed, Embase, Cochrane's Library, China National Knowledge Infrastructure (CNKI), and Wanfang databases on 11 October 2021. A random-effect model incorporating the heterogeneity was used to pool the results. The efficacy outcomes included the complete remission rate of proteinuria, overall response rate (the combined rates of patients with complete and partial remission of proteinuria), changes of urine protein excretion (UPE), serum creatinine (SCr), and estimated glomerular infiltrating rate (eGFR). RESULTS: Nineteen studies were included. Patients receiving the combined therapy had a higher complete remission rate (relative risk [RR]: 1.29, 95% CI: 1.08-1.55, p = 0.006; I2 = 0%) and overall response rate (RR: 1.18, 95% CI: 1.10-1.26, p < 0.001, I2 = 0%) compared to patients who received CS alone. Besides, combined therapy was associated with significantly reduced levels of UPE (mean difference [MD]: -0.30 g/24h, 95% CI: -0.43 to -0.16, p < 0.001; I2 = 34%) and SCr (MD: -7.55 mmol/L, 95% CI: -11.06 to -4.04, p < 0.001; I2 = 34%), and increased level of eGFR (MD: 6.51 mL/min/1.73 m2, 95% CI: 4.06-8.97, p < 0.001; I2 = 0%). The incidence of adverse events was not significantly different. CONCLUSIONS: Combined treatment with leflunomide and corticosteroids was more effective than corticosteroids alone for patients with IgA nephropathy.

Structural insights into the specific interaction between Geobacillus stearothermophilus tryptophanyl-tRNA synthetase and antimicrobial Chuangxinmycin.

The potential antimicrobial compound Chuangxinmycin (CXM) targets the tryptophanyl-tRNA synthetase (TrpRS) of both Gram-negative and Gram-positive bacteria. However, the specific steric recognition mode and interaction mechanism between CXM and TrpRS is unclear. Here, we studied this interaction using recombinant GsTrpRS from Geobacillus stearothermophilus by X-ray crystallography and molecular dynamics (MD) simulations. The crystal structure of the recombinant GsTrpRS in complex with CXM was experimentally determined to a resolution at 2.06 Å. After analysis using a complex-structure probe, MD simulations, and site-directed mutation verification through isothermal titration calorimetry, the interaction between CXM and GsTrpRS was determined to involve the key residues M129, D132, I133, and V141 of GsTrpRS. We further evaluated binding affinities between GsTrpRS WT/mutants and CXM; GsTrpRS was found to bind CXM through hydrogen bonds with D132 and hydrophobic interactions between the lipophilic tricyclic ring of CXM and M129, I133, and V141 in the substrate-binding pockets. This study elucidates the precise interaction mechanism between CXM and its target GsTrpRS at the molecular level and provides a theoretical foundation and guidance for the screening and rational design of more effective CXM analogs against both Gram-negative and Gram-positive bacteria.

Expression, purification and X-ray crystal diffraction analysis of alcohol dehydrogenase 1 from Artemisia annua L.

Alcohol dehydrogenase 1 identified from Artemisia annua (AaADH1) is a 40 kDa protein that predominately expressed in young leaves and buds, and catalyzes dehydrogenation of artemisinic alcohol to artemisinic aldehyde in artemisinin biosynthetic pathway. In this study, AaADH1 encoding gene was subcloned into vector pET-21a(+) and expressed in Escherichia coli. BL21(DE3), and purified by Co2+ affinity chromatography. Anion exchange chromatography was performed until the protein purity reached more than 90%. Crystallization of AaADH1 was conducted for further investigation of the molecular mechanism of catalysis, and hanging-drop vapour diffusion method was used in experiments. The results showed that the apo AaADH1 crystal diffracted to 2.95 Å resolution, and belongs to space group P1, with unit-cell parameters, a = 77.53 Å, b = 78.49 Å, c = 102.44 Å, α = 71.88°, ß = 74.02°, γ = 59.97°. The crystallization condition consists of 0.1 M Bis-Tris pH 6.0, 13% (w/v) PEG 8000 and 5% (v/v) glycerol.

The Complex Structure of Protein AaLpxC from Aquifex aeolicus with ACHN-975 Molecule Suggests an Inhibitory Mechanism at Atomic-Level against Gram-Negative Bacteria.

New drugs with novel antibacterial targets for Gram-negative bacterial pathogens are desperately needed. The protein LpxC is a vital enzyme for the biosynthesis of lipid A, an outer membrane component of Gram-negative bacterial pathogens. The ACHN-975 molecule has high enzymatic inhibitory capacity against the infectious diseases, which are caused by multidrug-resistant bacteria, but clinical research was halted because of its inflammatory response in previous studies. In this work, the structure of the recombinant UDP-3-O-(R-3-hydroxymyristol)-N-acetylglucosamine deacetylase from Aquifex aeolicus in complex with ACHN-975 was determined to a resolution at 1.21 Å. According to the solved complex structure, ACHN-975 was docked into the AaLpxC's active site, which occupied the site of AaLpxC substrate. Hydroxamate group of ACHN-975 forms five-valenced coordination with resides His74, His226, Asp230, and the long chain part of ACHN-975 containing the rigid alkynyl groups docked in further to interact with the hydrophobic area of AaLpxC. We employed isothermal titration calorimetry for the measurement of affinity between AaLpxC mutants and ACHN-975, and the results manifest the key residues (His74, Thr179, Tyr212, His226, Asp230 and His253) for interaction. The determined AaLpxC crystal structure in complex with ACHN-975 is expected to serve as a guidance and basis for the design and optimization of molecular structures of ACHN-975 analogues to develop novel drug candidates against Gram-negative bacteria.

Effect of Linker Length and Temperature on the Thermal Conductivity of Ethylene Dynamic Networks.

Dynamic covalent networks are a class of polymers containing exchangeable bonds. The influence of the thermodynamics and kinetics of dynamic bond exchange on the thermal conductivity and mechanical properties of dynamic networks is important for understanding how they differ from thermoplastics and thermosets. In this work, a series of ethylene dynamic networks are synthesized from benzene diboronic acid and alkane diols with different precise ethylene linker lengths. The thermal conductivity of these ethylene dynamic networks at 40 °C decreases from 0.19 to 0.095 W/(m K) when the ethylene linker length increases from 4 to 12 carbons. The thermal conductivity also has a strong temperature dependence, decreasing by a factor of 3 over the temperature range from -80 °C to 100 °C. The minimum thermal conductivity model predicts these trends of the thermal conductivity with variations in ethylene linker length and temperature.

TMEM98, a novel secretory protein, promotes endothelial cell adhesion as well as vascular smooth muscle cell proliferation and migration.

Transmembrane protein 98 (TMEM98) is a novel gene, and its function has not been well investigated. In a prior study, we have shown that siRNA-mediated knockdown of TMEM98 inhibited interleukin-8 (IL-8) promoted endothelial cell (EC) adhesion, as well as vascular smooth muscle cell (VSMC) proliferation and migration in the vascular endothelial and smooth muscle cell dysfunction. Herein, we used gain- and loss-of-function approaches combined with biochemical techniques to further explore the role of TMEM98 in the vascular wall cell. The expression and secretion of TMEM98 was increased in cultured human umbilical vein endothelial cells (HUVECs) and VSMCs treated with IL-8 and platelet-derived growth factor-BB (PDGF-BB). Also, PDGF-BB secretion was increased in TMEM98-treated HUVECs and VSMCs. Thus, it appears that TMEM98 and PDGF-BB form a positive feedback loop in potentiation of EC adhesion, as well as VSMC proliferation and migration. Knockdown of TMEM98 mediated by siRNA inhibited PDGF-BB-promoted EC adhesion by downregulating the expression of ICAM-1 and VCAM-1, as well as impaired the proliferation and migration of VSMCs by suppressing the AKT/GSK3ß/cyclin D1 signaling pathway and reducing the expression of ß-catenin. Hence, TMEM98 promoted EC adhesion by inducing the expression of ICAM-1/VCAM-1 and triggered VSMC proliferation and migration by activating the ERK and AKT/GSK3ß signaling pathways. Taken together, TMEM98 may serve as a potential therapeutic target for the clinical treatment of vascular endothelial and smooth muscle cell dysfunction.

Identification of Functional Fragments in gMYL6 and the Mechanism of Improving NK Cell-Mediated Cytotoxicity.

BACKGROUND: In a previous study, the unrecognized role of gMYL6 in the up-regulation of human NK cells development and cytotoxicity was reported. OBJECTIVE: To further elucidate the mechanism of action of small recombinant fragments of gMYL6 enhancing the NK cells activity. METHODS: Mononuclear cells were isolated from umbilical cord blood (UCB) by density-gradient centrifugation and NK cells were propagated and cultured. The small peptides from the gMYL6, with the ability to enhance the cytotoxicity of NK cells were screened by CCK-8 method and one of the most powerful peptides was identified for the next study. Flow cytometry was used to assess the proliferation and apoptosis of K562 cells, as well as the cell cycle arrest. The apoptosis of target cells was observed by AO/EB fluorescence staining, and the degree of apoptosis was assessed by flow cytometry. Protein imprinting method was also used to explore the pathway of small peptides to enhance the NK cells' activity. On the other hand, Real-time Quantitative PCR Detecting System was used to verify the mechanism of K562 cells suppression. RESULTS: Small D peptide significantly increased NK cells cytotoxicity and induced both cell cycle arrest at G2/M and apoptosis of K562 cells. CONCLUSION: Small D peptide could be a novel promising peptide for cancer immunotherapy since it was shown to promote the cytotoxicity of cord blood-derived NK cells.

Fluorescent Tb(III)-MOF for Fe(III) Ion Detection and Treatment Effect in Aortic Dissection by Reducing ß-receptor Expression and D-Dimer Production.

Iron is a class of essential elements involved in the metabolic process in all living organisms. However, excessive or deficient iron levels from normal ranges can lead to severe diseases. In this study, a fluorescent Tb(III)-based metal-organic framework with the chemical formula of [Tb(cptpy)3]n (1, Hcptpy = 4'-(4-carboxyphenyl)-2,2':6',2''-terpyridine) has been prepared under the hydrothermal condition successfully and its properties were determined by X-ray single-crystal diffraction, IR spectra, powder X-ray diffraction (PXRD) thermogravimetric analyses (TGA) and elemental analyses. Luminescent and sensing properties of complex 1 were examined closely, and it is shown that the Tb-MOF has the distinct ability to efficiently and selectively detect the Fe3+ ion and acetone. Furthermore, the RT-PCR was employed to determine the effect of compound on the ß-receptor and mmp-9 genes expression in cardiomyocytes. And the ELISA assay was used for the measurement of D-Dimer in the serum after compound treatment.

A Nano-shield Design for Separators to Resist Dendrite Formation in Lithium-Metal Batteries.

Lithium dendrite growth during repeated charge and discharge cycles of lithium-metal anodes often leads to short-circuiting by puncturing the porous separator. Here, a morphological design, the nano-shield, for separators to resist dendrites is presented. Through both mechanical analysis and experiment, it is revealed that the separator protected by the nano-shield can effectively inhibit the penetration of lithium dendrites owing to the reduced stress intensity generated and therefore mitigate the short circuit of Li metal batteries. More than 110 h of lithium plating life is achieved in cell tests, which is among the longest cycle life of lithium metal anode and five times longer than that of blank separators. This new aspect of morphological and mechanical design not only provides an alternative pathway for extending lifetime of lithium metal anodes, but also sheds light on the role of separator engineering for various electrochemical energy storage devices.

Minimized lithium trapping by isovalent isomorphism for high initial Coulombic efficiency of silicon anodes.

Silicon demonstrates great potential as a next-generation lithium ion battery anode because of high capacity and elemental abundance. However, the issue of low initial Coulombic efficiency needs to be addressed to enable large-scale applications. There are mainly two mechanisms for this lithium loss in the first cycle: the formation of the solid electrolyte interphase and lithium trapping in the electrode. The former has been heavily investigated while the latter has been largely neglected. Here, through both theoretical calculation and experimental study, we demonstrate that by introducing Ge substitution in Si with fine compositional control, the energy barrier of lithium diffusion will be greatly reduced because of the lattice expansion. This effect of isovalent isomorphism significantly reduces the Li trapping by ~70% and improves the initial Coulombic efficiency to over 90%. We expect that various systems of battery materials can benefit from this mechanism for fine-tuning their electrochemical behaviors.

Cucurbitacins extracted from Cucumis melo L. (CuEC) exert a hypotensive effect via regulating vascular tone.

As an effective medicine for jaundice in traditional Chinese medicine, Cucumis melo L. has been widely used in China. However, its effect on vascular function is still unclear. In this study, we extracted the compounds of Cucumis melo L., and the major ingredients were identified as cucurbitacins (CuEC, cucurbitacins extracted from Cucumis melo L.), especially cucurbitacin B. We replicated the toxicity in mice by intraperitoneal injection of a high dose of CuEC (2 mg/kg) and demonstrated that the cause of death was CuEC-induced impairment of the endothelial barrier and, thus, increased vascular permeability via decreasing VE-cadherin conjunction. The administration of low doses of CuEC (1 mg/kg) led to a decline in systolic blood pressure (SBP) without causing toxicity in mice. More importantly, CuEC dramatically suppressed angiotensin II (Ang II)-induced SBP increase. Further studies demonstrated that CuEC facilitated acetylcholine-mediated vasodilation in mesenteric arteries of mice. In vitro studies showed that CuEC induced vasodilation in a dose-dependent manner in mesenteric arteries of both mice and rats. Pretreatment with CuEC inhibited phenylephrine-mediated vasoconstriction. In summary, a moderate dose of CuEC reduced SBP by improving blood vessel tension. Therefore, our study provides new experimental evidence for developing new antihypertensive drugs.

Elevated expression of the V-ATPase D2 subunit triggers increased energy metabolite levels in KrasG12D -driven cancer cells.

Mutations of the Ras oncogene are frequently detected in human cancers. Among Ras-mediated tumorigenesis, Kras-driven cancers are the most dominant mutation types. Here, we investigated molecular markers related to the Kras mutation, which is involved in energy metabolism in Kras mutant-driven cancer. We first generated a knock-in KrasG12D cell line as a model. The genotype and phenotype of the Kras G12D -driven cells were first confirmed. Dramatically elevated metabolite characterization was observed in Kras G12D -driven cells compared with wild-type cells. Analysis of mitochondrial metabolite-related genes showed that two of the 84 genes in Kras G12D -driven cells differed from control cells by at least twofold. The messenger RNA and protein levels of ATP6V0D2 were significantly upregulated in Kras G12D -driven cells. Knockdown of ATP6V0D2 expression inhibited motility and invasion but did not affect the proliferation of Kras G12D -driven cells. We further investigated ATP6V0D2 expression in tumor tissue microarrays. ATP6V0D2 overexpression was observed in most carcinoma tissues, such as melanoma, pancreas, and kidney. Thus, we suggest that ATP6V0D2, as one of the V-ATPase (vacuolar-type H + -ATPase) subunit isoforms, may be a potential therapeutic target for Kras mutation cancer.

Interfacial Solar Steam Generation Enables Fast-Responsive, Energy-Efficient, and Low-Cost Off-Grid Sterilization.

Steam sterilization is widely used as one of the most reliable sterilization methods for public health. However, traditional steam sterilization mainly relies on electricity, a constrained resource for many developing countries and areas. The lack of available and affordable sterilization techniques in these areas is exposing human beings to a high risk of various epidemic diseases, and calls for the development of off-grid sterilization solutions. For the first time, the kinetic advantages of interfacial solar steam generation is fundamentally revealed and it is demonstrated that interfacial solar steam generation can enable fast-responsive (as short as 8.4 min for a full sterilization cycle) and energy-efficient (100 J mL-1 for steam reaching 121 °C) sterilization, superior to those of the conventional sterilization techniques. The key solar absorber is made of low cost and widely available biochar. A proof-of-concept sterilization system with a 10.5 L solar autoclave is built with very low cost of whole life-cycle and operates with minimum carbon footprint. Effective sterilization (≈99.999999% inactivation of pathogen), exceeding the requirements of Food and Drug Administration is demonstrated, making the sterilization strategy a promising and complementary personalized sterilization solution, particularly beneficial for off-grid areas.

Solubility-enhanced gMYL6 fused with a hexa-lysine tag promotes the cytotoxicity of human NK cells.

Goat myosin light chain 6 (gMYL6) is a constituent of certain extracted immunization-induced goat anti-cancer bioactive peptides (ACBPs). However, little is known about its activity onto NK cells which are the basic cellular attackers in cancer immunotherapy for patients with malignancies. Because of the complicated extraction process and low yield of gMYL6 out of the goat ACBPs' mixture, the Nano-flow liquid chromatography and C-terminal polycationic tag expression strategy were used to identify and enrich the peptide to investigate its bioactivity against cancers/tumors. The solubility-enhanced gMYL6 fused with a hexa-lysine tag showed a capacity of promoting the NK cells' cytotoxicity, making it a novel promising heterogeneous peptide cytokine against cancers.

Tuning Transpiration by Interfacial Solar Absorber-Leaf Engineering.

Plant transpiration, a process of water movement through a plant and its evaporation from aerial parts especially leaves, consumes a large component of the total continental precipitation (≈48%) and significantly influences global water distribution and climate. To date, various chemical and/or biological explorations have been made to tune the transpiration but with uncertain environmental risks. In recent years, interfacial solar steam/vapor generation is attracting a lot of attention for achieving high energy transfer efficiency. Various optical and thermal designs at the solar absorber-water interface for potential applications in water purification, seawater desalination, and power generation appear. In this work, the concept of interfacial solar vapor generation is extended to tunable plant transpiration by showing for the first time that the transpiration efficiency can also be enhanced or suppressed through engineering the solar absorber-leaf interface. By tuning the solar absorption of membrane in direct touch with green leaf, surface temperature of green leaf will change accordingly because of photothermal effect, thus the transpiration efficiency as well as temperature and relative humidity in the surrounding environment will be tuned. This tunable transpiration by interfacial absorber-leaf engineering can open an alternative avenue to regulate local atmospheric temperature, humidity, and eventually hydrologic cycle.

HuR induces inflammatory responses in HUVECs and murine sepsis via binding to HMGB1.

The aim of the present study was to explore the roles of human antigen R (HuR) in sepsis. Reverse transcription­quantitative polymerase chain reaction and western blot analyses demonstrated that overexpression of HuR increased the expression of high­mobility group box 1 (HMGB1) in human umbilical vein endothelial cells (HUVECs). HMGB1 was investigated as a potential target of HuR through bioinformatics and RNA­immunoprecipitation assays. Furthermore, treatment with HuR small interfering (si)RNA suppressed the lipopolysaccharide (LPS)­mediated release of HMGB1 and reduced HMGB1­mediated hyperpermeability and leukocyte migration in HUVECs and in septic mice. In addition, HuR­siRNA injection reduced cecal ligation and puncture (CLP)­induced HMGB1 release, reduced production of interleukin 6 and lowered mortality rates. Notably, the promotive effects of HuR overexpression on the inflammatory response were attenuated when HUVECs were co­treated with HMGB1 short hairpin RNA. Therefore, the present results indicated that the ectopic expression of HuR may induce inflammatory responses and thus sepsis by activating the HMGB1 signaling pathway.