Enhanced interactions of interlayer excitons in free-standing heterobilayers.

Strong, long-range dipole-dipole interactions between interlayer excitons (IXs) can lead to new multiparticle correlation regimes1,2, which drive the system into distinct quantum and classical phases2-5, including dipolar liquids, crystals and superfluids. Both repulsive and attractive dipole-dipole interactions have been theoretically predicted between IXs in a semiconductor bilayer2,6-8, but only repulsive interactions have been reported experimentally so far3,9-16. This study investigated free-standing, twisted (51°, 53°, 45°) tungsten diselenide/tungsten disulfide (WSe2/WS2) heterobilayers, in which we observed a transition in the nature of dipolar interactions among IXs, from repulsive to attractive. This was caused by quantum-exchange-correlation effects, leading to the appearance of a robust interlayer biexciton phase (formed by two IXs), which has been theoretically predicted6-8 but never observed before in experiments. The reduced dielectric screening in a free-standing heterobilayer not only resulted in a much higher formation efficiency of IXs, but also led to strongly enhanced dipole-dipole interactions, which enabled us to observe the many-body correlations of pristine IXs at the two-dimensional quantum limit. In addition, we firstly observed several emission peaks from moiré-trapped IXs at room temperature in a well-aligned, free-standing WSe2/WS2 heterobilayer. Our findings open avenues for exploring new quantum phases with potential for applications in non-linear optics.

Twisted van der Waals Quantum Materials: Fundamentals, Tunability, and Applications.

Twisted van der Waals (vdW) quantum materials have emerged as a rapidly developing field of two-dimensional (2D) semiconductors. These materials establish a new central research area and provide a promising platform for studying quantum phenomena and investigating the engineering of novel optoelectronic properties such as single photon emission, nonlinear optical response, magnon physics, and topological superconductivity. These captivating electronic and optical properties result from, and can be tailored by, the interlayer coupling using moiré patterns formed by vertically stacking atomic layers with controlled angle misorientation or lattice mismatch. Their outstanding properties and the high degree of tunability position them as compelling building blocks for both compact quantum-enabled devices and classical optoelectronics. This paper offers a comprehensive review of recent advancements in the understanding and manipulation of twisted van der Waals structures and presents a survey of the state-of-the-art research on moiré superlattices, encompassing interdisciplinary interests. It delves into fundamental theories, synthesis and fabrication, and visualization techniques, and the wide range of novel physical phenomena exhibited by these structures, with a focus on their potential for practical device integration in applications ranging from quantum information to biosensors, and including classical optoelectronics such as modulators, light emitting diodes, lasers, and photodetectors. It highlights the unique ability of moiré superlattices to connect multiple disciplines, covering chemistry, electronics, optics, photonics, magnetism, topological and quantum physics. This comprehensive review provides a valuable resource for researchers interested in moiré superlattices, shedding light on their fundamental characteristics and their potential for transformative applications in various fields.

Mitochondrial calcium uniporter involved in foodborne mycotoxin-induced hepatotoxicity.

Foodborne mycotoxins are toxic metabolites that are produced by fungi. The widespread contamination of food and its by-products by mycotoxins is a global food safety problem that potentially threatens public health and other exposed animals. Most foodborne mycotoxins induce hepatotoxicity. However, only few studies have investigated the regulatory mechanisms of mitochondrial calcium transport monomers in mycotoxin-induced hepatotoxicity. Therefore, according to relevant studies and reports, this review suggests that intracellular Ca(2 +) homeostasis and mitochondrial Ca(2 +) uniporter are involved in the regulation of mycotoxin-induced hepatotoxicity. This review provides some ideas for future research involving mitochondrial Ca(2 +) uniporter in the molecular targets of mycotoxin-induced hepatotoxicity, as well as a reference for the research and development of related drugs and the treatment of related diseases.

TRAF3 plays a role in lupus nephritis by regulating Th17 cell and Treg cell balance as well as NF-κB signaling pathway in mice.

Lupus nephritis (LN) occurs with inflammatory lesion in patients suffering from systemic lupus erythematosus (SLE). Tumor necrosis factor (TNF) receptor associated factor 3 (TRAF3) is an important mediator in inflammation. To explore the roles of TRAF3 in LN, the LN mouse model was firstly established with intraperitoneal (i.p.) injection of pristine. Our results found that the amount of urinary protein was increased evidently at day 28, and renal damage occurred in the LN mouse model, but the TRAF3 knockdown reduced the urinary protein and alleviated the inflammatory lesion. The proinflammatory cytokines TNF-α, IL-1ß, IL-17a, IFN-γ and IgM, IgG antibody were enriched, but there was little amount of IL-10 in the LN mouse model. Moreover, the amount of CD40+ B cells, CD4+ T cells sub-type, Th17 cells were abundant, and the proteins TRAF3, TRAF2, NF-κBp52, IKKα, ICAM1 in the kidney were highly expressed in the LN mouse model. However, TRAF3 knockdown enhanced the production of IL-10 and reduced the amount of pro-inflammatory cytokines, immunoglobulin, and the protein expressions of TRAF3, TRAF2, NF-κBp52, IKKα, ICAM1. In conclusion, TRAF3 plays a role in LN by regulating Th17 cell and Treg cell balance as well as NF-κB signaling pathway in mice.

Dietary fructose and risk of metabolic syndrome in Chinese residents aged 45 and above: results from the China National Nutrition and Health Survey.

BACKGROUND: A growing number of researches supported that dietary fructose was associated with most of the key features of metabolic syndrome (MetS). However, there was no related epidemiological studies among Chinese population, despite the sharp increase in MetS cases. This study explores the relationship between dietary fructose and MetS among Chinese residents aged 45 and above. METHODS: A total of 25,528 participants (11,574 males and 13,954 females) were included in this nationwide representative cross-sectional study of China National Nutrition and Health Survey. Dietary fructose intake was assessed by 3-day 24-h dietary records. MetS was defined by the International Diabetes Federation and Chinese Diabetes Society criteria. RESULTS: The consumption of dietary fructose was 11.6 g/day for urban residents and 7.6 g/day for rural residents. Fruits and vegetables as well as their products were the main sources of fructose intake. There was no association between dietary fructose intake and the odds of having MetS in both urban (P = 0.315) and rural residents (P = 0.230) after adjustment for confounding factors. Moreover, for urban residents participating physical activities, the odds of having MetS in the fourth quartiles (OR: 0.67; 95%CI: 0.52-0.87) was lower than that in the first quartile. In the sensitivity analysis, a significant reduction in the odds of having MetS was also found in the fourth quartiles (OR, 95%CI: 0.68, 0.51-0.90; 0.67, 0.49-0.91; 0.74, 0.56-0.99) compared with the first quartile when excluding smokers, alcohol users, and underweight/obesity, respectively. And there was no association between dietary fructose intake and the odds of having MetS after multivariate adjustment stratified by gender, smoking and alcohol use. CONCLUSIONS: Under the current dietary fructose intake status, there was no association between dietary fructose intake and the odds of having MetS among Chinese residents aged 45 and above. Physical activity and relatively low fructose intake may have a beneficial synergistic effect on MetS.

Extinction ratio and image accuracy of relayed-microgrid polarimetric imaging systems: theory and experiment.

Herein we propose a polarimetric imaging system that uses a microgrid polarizer placed on the conjugate point of two telecentric optical paths, matching large polarizers with small sensors and thus effectively decreasing optical crosstalk and increasing imaging accuracy. We define a new parameter used to construct the high-precision polarization vector transfer model under crosstalk. Using the equivalent surface of the detector, we establish the relationship between focal shift and crosstalk ratio and obtain a multi-physical coupling mathematical model that accounts for the crosstalk ratio, extinction ratio, sensor error, target vector, and imaging accuracy of the system. The relayed-microgrid polarimetric imaging system is anticipated to be able to help identify objects of interest for remote sensing and military applications.

Highly Enhanced Many-Body Interactions in Anisotropic 2D Semiconductors.

Atomically thin two-dimensional (2D) semiconductors have presented a plethora of opportunities for future optoelectronic devices and photonics applications, made possible by the strong light matter interactions at the 2D quantum limit. Many body interactions between fundamental particles in 2D semiconductors are strongly enhanced compared with those in bulk semiconductors because of the reduced dimensionality and, thus, reduced dielectric screening. These enhanced many body interactions lead to the formation of robust quasi-particles, such as excitons, trions, and biexcitons, which are extremely important for the optoelectronics device applications of 2D semiconductors, such as light emitting diodes, lasers, and optical modulators, etc. Recently, the emerging anisotropic 2D semiconductors, such as black phosphorus (termed as phosphorene) and phosphorene-like 2D materials, such as ReSe2, 2D-perovskites, SnS, etc., show strong anisotropic optical and electrical properties, which are different from conventional isotropic 2D semiconductors, such as transition metal dichalcogenide (TMD) monolayers. This anisotropy leads to the formation of quasi-one-dimensional (quasi-1D) excitons and trions in a 2D system, which results in even stronger many body interactions in anisotropic 2D materials, arising from the further reduced dimensionality of the quasi-particles and thus reduced dielectric screening. Many body interactions have been heavily investigated in TMD monolayers in past years, but not in anisotropic 2D materials yet. The quasi-particles in anisotropic 2D materials have fractional dimensionality which makes them perfect candidates to serve as a platform to study fundamental particle interactions in fractional dimensional space. In this Account, we present our recent progress related to 2D phosphorene, a 2D system with quasi-1D excitons and trions. Phosphorene, because of its unique anisotropic properties, provides a unique 2D platform for investigating the dynamics of excitons, trions, and biexcitons in reduced dimensions and fundamental many body interactions. We begin by explaining the fundamental reasons for the highly enhanced interactions in the 2D systems influenced by dielectric screening, resulting in high binding energies of excitons and trions, which are supported by theoretical calculations and experimental observations. Phosphorene has shown much higher binding energies of excitons and trions than TMD monolayers, which allows robust quasi-particles in anisotropic materials at room temperature. We also discuss the role of extrinsic defects induced in phosphorene, resulting in localized excitonic emissions in the near-infrared range, making it suitable for optical telecommunication applications. Finally, we present our vision of the exciting device applications based on the highly enhanced many body interactions in phosphorene, including exciton-polariton devices, polariton lasers, single-photon emitters, and tunable light emitting diodes (LEDs).

Effect of sensor SNR and extinction ratio on polarimetric imaging error for nanowire-based systems.

High-sensor SNR and high extinction ratio (ER), which are often contradictory requirements for nanowire-filter-based polarimetric imaging systems, aid in attenuating polarimetric imaging system errors. Expressions were derived to analyze their attenuation effects and then simplified using photoelectronic numbers received by superpixels (PNRS). The first-derivative ratios of PNRS and ER were calculated to compare their attenuation effects. Mathematical models and experiments conducted using polarimetric imaging systems with various ERs and PNRSs indicate that systems with low PNRS and high ER exhibit a polarization error affected more by the attenuation effect of the PNRS than that of the ER. When the system ER is higher than 28, the attenuation effect of the PNRS is higher than that of the ER. Thus, system error attenuation is a trade-off between sensor SNR and ER.

Enhancing 2D Photonics and Optoelectronics with Artificial Microstructures.

By modulating subwavelength structures and integrating functional materials, 2D artificial microstructures (2D AMs), including heterostructures, superlattices, metasurfaces and microcavities, offer a powerful platform for significant manipulation of light fields and functions. These structures hold great promise in high-performance and highly integrated optoelectronic devices. However, a comprehensive summary of 2D AMs remains elusive for photonics and optoelectronics. This review focuses on the latest breakthroughs in 2D AM devices, categorized into electronic devices, photonic devices, and optoelectronic devices. The control of electronic and optical properties through tuning twisted angles is discussed. Some typical strategies that enhance light-matter interactions are introduced, covering the integration of 2D materials with external photonic structures and intrinsic polaritonic resonances. Additionally, the influences of external stimuli, such as vertical electric fields, enhanced optical fields and plasmonic confinements, on optoelectronic properties is analysed. The integrations of these devices are also thoroughly addressed. Challenges and future perspectives are summarized to stimulate research and development of 2D AMs for future photonics and optoelectronics.

Enhanced interactions of excitonic complexes in free-standing WS2.

Excitonic complexes, bound states of electrons and holes, provide a promising platform in monolayer transition-metal dichalcogenide (TMDC) semiconductors for investigating diverse many-body interaction phenomena. The surrounding dielectric environment has been found to strongly influence the excitonic properties of the TMDC monolayers. While the impact of different dielectric surroundings on two-dimensional semiconductor materials and their strong correlations have been well studied, the effects on exciton formation and its properties resulting from a further reduction in dielectric screening remain elusive. In this study, we examined free-standing tungsten disulfide (WS2) monolayers, where the efficient generation of higher-order correlated excitonic complexes is readily observed. This phenomenon arises from the effective mutual interactions among excitons and internal carriers, attributed to the modulated exciton dynamics generated by the further reduced dielectric screening effect in the freestanding structure. The formation efficiency of excitonic complexes is enhanced and the multiple biexciton species (five particles such as charged biexcitons and acceptor/donor-bound biexcitons) are successfully induced under low excitation intensity and moderate temperature conditions. Our findings offer valuable insights into the influence of the dielectric environment on exciton interactions and enable a productive avenue for exploring fundamental many-body interactions, providing new possibilities for dielectric engineering of atomic thin semiconductors.

Influence of ammonia nitrogen management strategies on microbial communities in biofloc-based aquaculture systems.

Controlling ammonia nitrogen is very important in intensive aquaculture. This study evaluated how different management strategies, i.e., chemoautotrophic (control), heterotrophic bacterial enhancement using carbon in glucose or polyhydroxy butyrate-hydroxy valerate (PHBV), and mature biofloc application, affect water quality and microbial community structure and composition. The management strategies were examined during the domestication and fish culture stages. In the domestication stage, the average NO2--N concentration, pH, and DO in the glucose-added groups were significantly lower than those in the control and PHBV groups. All water quality parameters differed significantly among treatment groups in the culture stage. Carbon additions decreased both bacterial richness and diversity in the fish culture stage. Both principal coordinate analysis and hierarchical cluster analysis grouped the 33 bacteria community samples from the two stages into four clusters, which were closely related to management strategy. The dominant taxa of the clusters were identified using linear discriminant analysis effect size (LEfSe). The biomarkers of Cluster I included Marinomonas, Photobacterium, and Vibrio. Porticoccus and Clade-1a were identified as the biomarkers of Cluster II. Marivia, Leucothrix, and Phaeodactylibacter were identified as the biomarkers of Cluster IV. The Cluster I biomarkers were positively correlated with NO2--N, while those of Cluster IV were positively correlated with NO3--N. The redundancy analysis showed that the bacterial communities and biomarkers were influenced by water quality parameters. Quantitative real-time PCR analysis revealed significant differences in the abundances of the amoA and nxrB genes among treatments and between the two stages. The abundance of the amoA gene was higher in the control group than in the carton-added treatments at the ends of both stages. This study provides an important theoretical basis for the selection of efficient ammonia nitrogen control strategies in aquaculture systems.

Extraordinary Phonon Displacement and Giant Resonance Raman Enhancement in WSe2/WS2 Moiré Heterostructures.

Twisted van der Waals heterostructures are known to induce surprisingly diverse and intriguing phenomena, such as correlated electronic phase and unconventional optical properties. This can be realized by controlled rotation of adjacent atomic planes, which provides an uncommon way to manipulate inelastic light-matter interactions. Here, we discover an extraordinary blue shift of 5-6 wavenumbers for high-frequency phonon modes in WS2/WSe2 twisted heterobilayers, captured meticulously using Raman spectroscopy. Phonon spectra displace rapidly over a subtle change in interlayer twist angle owing to heterostrain and atomic reconstruction from the Moiré pattern. First-order linear coefficients of the phonon modes in twisted heterostructures are further found to increase largely compared to their monolayer counterpart and vary immensely with the twist angle. Exceptional and extravagant enhancement of up to 50-fold is observed in the Raman vibrational intensity at a specific twist angle; this is largely influenced by the resonance process derived from a simple critical twist angle model. In addition, we depict how the resonance can be modulated by changing the thermal conditions and also the stacking angle. Therefore, our work further highlights the twist-driven phonon dynamics in pristine two-dimensional heterostructures, adding vital insight into Moiré physics and promoting comprehensive understanding of structural and optical properties in Moiré superlattices.

Engineering the Dynamics and Transport of Excitons, Trions, and Biexcitons in Monolayer WS2.

The study of transport and diffusion dynamics of quasi-particles such as excitons, trions, and biexcitons in two-dimensional (2D) semiconductors has opened avenues for their application in high-speed excitonic and optoelectronic devices. However, long-range transport and fast diffusion of these quasi-particles have not been reported for 2D systems such as transition metal dichalcogenides (TMDCs). The reported diffusion coefficients from TMDCs are low, limiting their use in high-speed excitonic devices and other optoelectronic applications. Here, we report the highest exciton diffusion coefficient value in monolayer WS2 achieved via engineering the radiative lifetime and diffusion lengths using static back-gate voltage and substrate engineering. Electrostatic doping is observed to modulate the radiative lifetime and in turn the diffusion coefficient of excitons by ∼three times at room temperature. By combining electrostatic doping and substrate engineering, we push the diffusion coefficient to an extremely high value of 86.5 cm2/s, which has not been reported before in TMDCs and is even higher than the values in some 1D systems. At low temperatures, we further report the control of dynamic and spatial diffusion of excitons, trions, and biexcitons from WS2. The electrostatic control of dynamics and transport of these quasi-particles in monolayers establishes monolayer TMDCs as ideal candidates for high-speed excitonic circuits, optoelectronic, and photonic device applications.

Direct observation of contact resistivity for monolayer TMD based junctions via PL spectroscopy.

Monolayer transition metal dichalcogenides (mTMDs) possess a direct band gap and strong PL emission that is highly sensitive to doping level and interfaces, laying the foundation for investigating the contact between mTMD and metal via PL spectroscopy. Currently, electrical methods have been utilized to measure the contact resistance (RC), but they are complicated, time-consuming, high-cost and suffer from inevitable chemical disorders and Fermi level pinning. In addition, previously reported contact resistances comprise both Schottky barrier and tunnel barrier components. Here, we report a simple, rapid and low-cost method to study the tunnel barrier dominated contact resistance of mTMD based junctions through PL spectroscopy. These junctions are free from chemical disorders and Fermi level pinning. Excluding the Schottky barrier component, solely tunnel barrier dominated contact resistances of 1 L MoSe2/Au and 1 L MoSe2/graphene junctions were estimated to be 147.8 Ω µm and 54.9 Ω µm, respectively. Density functional theory (DFT) simulations revealed that the larger RC of the former was possibly due to the existence of intrinsic effective potential difference (Φbarrier) between mTMD and metal. Both junctions exhibit an increasing tendency of RC as temperature decreases, which is probably attributed to the thermal expansion coefficient (TEC) mismatch-triggered interlayer spacing (d) increase and temperature-induced doping. Remarkably, a significant change of RC was observed in 1 L MoSe2/Au junctions, which is possibly ascribed to the changes of their orbital overlaps. Our results open new avenues for exploring fundamental metal-semiconductor contact principles and constructing high-performance devices.

Statistical optimization of medium composition for aspergiolide A production by marine-derived fungus Aspergillus glaucus.

Statistical methodologies were employed to optimize submerged culture medium for the production of a novel antineoplastic compound aspergiolide A by a marine-derived fungus Aspergillus glaucus HB1-19 for the first time. Orthogonal design was preformed to determine the initial composition. Then Plackett-Burman design was applied to evaluate the influence of related nutrients, and yeast extract paste, soybean powder and sodium glutamate were confirmed as critical factors in the medium. Response surface methodology (RSM) was finally taken as an effective approach to optimize the combination of the obtained three significant factors. The predicted maximal aspergiolide A production of 62.4 mg/L appeared at the region where the concentrations of sodium glutamate, soybean powder, and yeast extract paste were 2, 1, and 1.07 g/L, respectively. Under the proposed optimized conditions, the experimental aspergiolide A production reached 71.2 mg/L. The correlation between predicted value and measured value of these experiments proved the validity of the response model. After optimization, aspergiolide A production increased 4.22 times compared to that of the original medium. Elemental analysis was finally taken into consideration, and carbon-nitrogen ratio in the medium increased from 20.1:1 to 86.6:1. This great difference was inferred as the most important reason for production enhancement by metabolic pathway analysis.

Low molecular weight heparin monotherapy for recurrent abortion with antiphospholipid system: A protocol of a systematic review.

BACKGROUND: Previous clinical studies reported low molecular weight heparin (LMWH) monotherpay has been utilized for the treatment of recurrent abortion (RCA) with antiphospholipid system (APS). However, its efficacy is still inconclusive. This systematic review aims to assess its efficacy and safety for patients with RCA and APS. METHODS: A systematic literature search for article up to February 2019 will be conducted in 9 databases: Cochrane Library, EMBASE, MEDILINE, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Information, and Wanfang Data. Inclusion criteria are randomized control trials of LMWH monotherpay for patients with RCA and APS. The Cochrane risk of bias tool will be used to evaluate the methodological quality for each qualified study. The summary results will be showed by using fixed-effects and random-effects models for pooling the data based on the heterogeneity of included studies. RESULTS: This systematic review will assess the clinical efficacy and safety of LMWH monotherpay in treating RCA with APS. The primary outcome is pregnancy loss. The secondary outcomes include frequency of preterm delivery, live birth rates, maternal and fetal complications, as well as adverse events. CONCLUSION: The findings of this study will summarize the present evidence to judge whether LMWH monotherpay is an effective therapy for patients with RCA and APS. DISSEMINATION AND ETHICS: The findings of this study will be published by through peer-reviewed journals. This study does not needs ethic documents, because it will not analyze individual patient data. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019121064.

[Effects of curcumin on liver fibrosis induced by cholestasis in mice].

OBJECTIVE: To investigate the protective effects of curcumin on bile duct ligation(BDL)-induced liver cholestasis in mice, so as to provide a new treatment strategy for liver fibrosis. METHODS: Forty-two healthy adult male BALB/c mice were randomly divided into sham group (n =6), sham+curcumin group (n=6), BDL treatment group (n=10), BDL+curcumin group(n=10), BDL+curcumin+ZnPP group (n=10). Seven days after BDL operation, the sham operation + curcumin group and the BDL+ curcumin group were treated with curcumin at the dose of 30 mg/kg by intraperitoneal injection once a day for 7 days.The mice in BDL+ curcumin +ZnPP group were treated with curcumin (30 mg/kg) and ZnPP (50 µmol/kg) by intraperitoneal injection once a day for 7 days. For the sham group and the BDL group, mice were treated with equal-volume saline daily by intraperitoneal injection. After 14 days of BDL, the plasma and liver tissues were collected, the levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured. The pathological changes of liver tissue and liver fibrosis were observed, and the protein expression of HO-1 in liver tissue was detected. RESULTS: Compared with the sham group, mice in the BDL group had enlarged liver gallbladder and the serum levels of ALT and AST were increased significantly (P＜0.05). Meanwhile, the results of Sirius red staining and qRT-PCR of pro-fibrosis related genes showed collagen deposition in the liver, and immunohistochemistry of macrophages and neutrophils showed inflammatory cell infiltration in the liver. Compared with the BDL group, the serum levels of ALT and AST in the curcumin treatment group were decreased significantly (P＜0.05), collagen deposition and inflammatory cell infiltration were improved, and HO-1 expression was increased (P＜0.05) after curcumin treatement. In the curcumin treatment group, the protective effect of curcumin on liver injury could be reversed by HO-1 active inhibitor ZnPP. CONCLUSION: Curcumin can improve liver inflammation and fibrosis caused by BDL, and this protective effect is related to the regulation of HO-1 activity by curcumin.

Heme oxygenase-1 attenuates seawater drowning-induced acute lung injury through a reduction in inflammation and oxidative stress.

OBJECTIVE: Heme oxygenase-1 (HO-1) plays a critical protective role in various insults-induced acute lung injury (ALI) through its strong anti-inflammatory, anti-oxidant, and anti-apoptotic properties, but its protective role and mechanism on seawater aspiration-induced acute lung injury remains unclear. This study aimed to explore the therapeutic potential and mechanism of HO-1 to attenuate seawater aspiration-induced ALI in vivo and in vitro. METHODS: The viability and invasion of A549 cell were analyzed through cell counting kit-8 and lactate dehydrogenase release assay; the transcriptional level of inflammatory cytokines (TNF-α, IL-6, IL-8 and MCP-1) and cell proliferation-related cytokines (FoxM1, Ccnb1 and Cdc25C) in seawater-treated A549 cell were tested by qPCR; apoptotic cells were analyzed by flow cytometryd; HO-1mRNA and protein were determined by qPCR and western blotting; the fluorescent indicators (DCFH-DA, dihydroethidium, MitoSox Red and Fluo-4) were used to monitor generation of ROS and mitochondrial function. The lung wet/dry weight radio and lactate dehydrogenase activity, Sirius red staining, TUNEL assay and immunohistochemical staining with anti-pan Cytokeratin antibody were analyzed in seawater-drowning mice. The role of HO-1 on seawater-drowning pulmonary injury was explored via HO-1 activity inhibitors (Zinc protoporphyrin) in vitro and in vivo. RESULTS: Seawater exposure decreased the cellular viability, increased the production of pro-inflammatory cytokines (IL-6, IL-8 and TNF-α), induced cellular apoptosis and inhibited the expression of cell proliferation-related cytokines (FoxM1, Ccnb1 and Cdc25C). Moreover, seawater exposure led to mitochondrial dysfunction in A549 cells. Supplement of HO-1 sepcific inducer (heme) or its catalytic product (biliverdin) significantly attenuated seawater-induced A549 damage and promoted cell proliferation. However, Zinc protoporphyrin abolished the beneficial effects of HO-1 on seawater drowning-induced pulmonary tissue injury. CONCLUSION: HO-1 attenuates seawater drowning-induced lung injury by its anti-inflammatory, anti-oxidative, and anti-apoptosis function.

Ferroelectric-Driven Exciton and Trion Modulation in Monolayer Molybdenum and Tungsten Diselenides.

In this work, we show how domain-engineered lithium niobate can be used to selectively dope monolayer molybdenum selenide (MoSe2) and tungsten selenide (WSe2) and demonstrate that these ferroelectric domains can significantly enhance or inhibit photoluminescence (PL), with the most dramatic modulation occurring at the heterojunction interface between two domains. A micro-PL and Raman system is used to obtain spatially resolved images of the differently doped transition metal dichalcogenides (TMDs). The domain-inverted lithium niobate causes changes in the TMDs due to electrostatic doping as a result of the remnant polarization from the substrate. Moreover, the differently doped TMDs (n-type MoSe2 and p-type WSe2) exhibit opposite PL modulation. Distinct oppositely charged domains were obtained with a 9-fold PL enhancement for the same single MoSe2 sheet when adhered to the positive (P+) and negative (P-) domains. This sharp PL modulation on the ferroelectric domain results from different free electron or hole concentrations in the material's conduction band or valence band. Moreover, excitons dissociate rapidly at the interface between the P+ and P- domains due to the built-in electric field. We are able to adjust the charge on the P+ and P- domains using temperature via the pyroelectric effect and observe rapid PL quenching over a narrow temperature range, illustrating the observed PL modulation is electronic in nature. This observation creates an opportunity to harness the direct bandgap TMD 2D materials as an active optical component for the lithium niobate platform using domain engineering of the lithium niobate substrate to create optically active heterostructures that could be used for photodetectors or even electrically driven optical sources on-chip.

Modulated interlayer charge transfer dynamics in a monolayer TMD/metal junction.

The performance of optoelectronic devices based on monolayer transition-metal dichalcogenide (mTMD) semiconductors is significantly affected by the contact at the mTMD-metal interface, which is dependent on interlayer interactions and coupling. Here, we report a systematic optical method to investigate the interlayer charge transfer and coupling in a mTMD-metal heterojunction. Giant photoluminescence (PL) quenching was observed in a monolayer MoS2/Pd (1L MoS2/Pd) junction which is mainly due to the efficient interlayer charge transfer between Pd and MoS2. 1L MoS2/Pd also exhibits an increase in the PL quenching factor (η) as the temperature decreases, due to a reduction of the interlayer spacing. Annealing experiments were also performed which supported interlayer charge transfer as the main mechanism for the increase of η. Moreover, a monolayer MoS2/Au (1L MoS2/Au) junction was fabricated for engineering the interlayer charge transfer. Interestingly, a narrowing effect of the full width at half maximum (FWHM) was encountered as the junctions changed from 1L MoS2/SiO2 → 1L MoS2/Au → 1L MoS2/Pd, possibly originating from a change of the doping level induced weakening of exciton-carrier scattering. Our results deepen the understanding of metal-semiconductor junctions for further exploring fundamental phenomena and enabling high-performance devices using mTMD-metal junctions.