Ciclopirox mitigates inflammatory response in LPS-induced septic shock via inactivation of SORT1-mediated wnt/ß-Catenin signaling pathway.

OBJECTIVE: Septic shock, the most severe stage of sepsis, is a deadly inflammatory disorder with high mortality. Ciclopirox (CPX) is a broad-spectrum antimycotic agent which also exerts anti-inflammatory effects in human diseases. However, whether CPX can relieve inflammatory response in LPS-induced septic shock remains unclear. MATERIALS AND METHODS: Male C57BL/6 mice LPS were injected intraperitoneally with LPS to simulate septic shock in vivo. RAW264.7 cells and bone marrow-derived macrophages (BMDMs) were subject to LPS treatment to simulate septic shock in vitro. ELISA was applied to detect the level of pro-inflammatory cytokines. Cell viability was assessed by CCK-8 assay. Protein levels was detected by western blotting. RESULTS: CPX enhanced the survival rate and attenuated inflammation in mice with LPS-induced septic shock. Similarly, CPX dose-dependently mitigated LPS-induced inflammation in BMDMs. It was also found that Sortilin 1 (SORT1) was upregulated in both in vivo and in vitro models of LPS-induced septic shock. In addition, SORT1 overexpression counteracted the alleviative effects of CPX on the inflammation response of LPS-challenged BMDMs by activating the Wnt/ß-Catenin signaling. Furthermore, BML-284 (a Wnt/ß-Catenin agonist) treatment also abrogated CPX-mediated moderation of LPS-triggered inflammatory reaction in BMDMs. CONCLUSIONS: In sum, we found that CPX protected against LPS-induced septic shock by mitigating inflammation via SORT1-mediated Wnt/ß-Catenin signaling pathway.

Multiscale structures and rheology of bisurea-loaded resins for anti-sagging applications.

Four representative bisurea molecules (HDI-BA, MDI-BA, TDI-BA, and IPDI-BA) were synthesized and dispersed simultaneously by reacting benzylamine (BA) with various types of diisocyanates in a polyester/ortho-xylene resin medium to produce bisurea-loaded resins (BLRs) for anti-sagging application with paints and coating materials. These bisurea molecules are symmetric and differ only in the central spacer unit, thereby presenting an ideal and simplest model system to delve into the structure-performance relationship. The multiscale structural features arising from self-assembly in each of the BLRs were scrutinized using the combination of multi-angular dynamic light scattering (DLS), small-angle light/X-ray scattering (SALS/SAXS), rheology, and scanning electron/optical microscopy (SEM/OM) characterization. All four BLRs were revealed to foster micron-sized, mostly sphere-like agglomerates, with distinct hierarchical structures that correlate well with their thixotropic and anti-sagging performances. Three BLRs (HDI-BA, MDI-BA, and TDI-BA) produce similar rod-like packing units (10 × 1 × 1 nm3), with only one exception (IPDI-BA) that produces a spherical packing unit (2 nm in diameter). However, the bulk feature of the agglomeration state, which dictates the thixotropic and anti-sagging properties, cannot be readily foreseen from the chemical structure or elementary packing unit of a bisurea. The present findings, while confirming the importance of optimum molecular design that controls the early-stage self-assembly behavior of a bisurea in resin media, highlight the necessity of resolving detailed (multiscale) structural features in order to establish the full structure-performance relationship imperatively needed for like material systems and applications.

Electric-field driven photoluminescence probe of photoelectric conversion in InGaN-based photovoltaics.

The spatial distribution of electric field in photovoltaic multiple quantum wells (MQWs) is extremely important to dictate the mutual competition of photoelectric conversion and optical transition. Here, electric-field-driven photoluminescence (PL) in both steady-state and transient-state has been utilized to directly investigate the internal photoelectric conversion processes in InGaN-based MQW photovoltaic cell. As applying the reversed external electric field, the compensation of the quantum confined stark effect (QCSE) in InGaN QW is beneficial to help the photoabsorbed minor carriers drift out from the localized states, whereas extremely weakening the PL radiative recombination. A directly driven force by the reversed external electric field decreases the transit time of photocarriers drifting in InGaN QW. And hence, the overall dynamic PL decay including both the slow and fast processes gradually speeds up from 19.2 ns at the open-circuit condition to 3.9 ns at a negative bias of -3 V. In particular, the slow PL decay lifetime declines more quickly than that of the fast one. It is the delocalization of photocarriers by electric-field drift that helps to further enhance the high-efficiency photoelectric conversion except for the tunneling transport in InGaN-based MQW photovoltaics. Therefore, it can be concluded that the electric-field PL probe may provide a direct method for evaluating the photoelectric conversion in multilayer quantum structures and related multijunction photovoltaic cells.

Interfacial carrier transport properties of a gallium nitride epilayer/quantum dot hybrid structure.

Electron transport layers (ETLs) play a key role in the electron transport properties and photovoltaic performance of solar cells. Although the existing ETLs such as TiO2, ZnO and SnO2 have been widely used to fabricate high performance solar cells, they still suffer from several inherent drawbacks such as low electron mobility and poor chemical stability. Therefore, exploring other novel and effective electron transport materials is of great importance. Gallium nitride (GaN) as an emerging candidate with excellent optoelectronic properties attracts our attention, in particular its significantly higher electron mobility and similar conduction band position to TiO2. Here, we mainly focus on the investigation of interfacial carrier transport properties of a GaN epilayer/quantum dot hybrid structure. Benefiting from the quantum effects of QDs, suitable energy level arrangements have formed between the GaN and CdSe QDs. It is revealed that the GaN epilayer exhibits better electron extraction ability and faster interfacial electron transfer than the rutile TiO2 single crystal. Moreover, the corresponding electron transfer rates of 4.44 × 108 s-1 and 8.98 × 108 s-1 have been calculated, respectively. This work preliminarily shows the potential application of GaN in quantum dot solar cells (QDSCs). Carefully tailoring the structure and optoelectronic properties of GaN, in particular realizing the low-temperature deposition of high-quality GaN on various substrates, will significantly promote the construction of highly efficient GaN-ETL based QDSCs.

Two-Step Deposition of an Ultrathin GaN Film on a Monolayer MoS2 Template.

Ultrathin gallium nitride (GaN) application can be profoundly influenced by its quality, especially the issue of amorphous interfacial layers formed on conventional substrates. Herein, we report a two-step deposition of an ultrathin GaN film via the plasma-enhanced atomic layer deposition (PEALD) technique on a mono-MoS2 template over a SiO2/Si substrate for quality improvement, by starting the deposition temperature at 260 °C and then ramping it to 320 °C. It was found that a lower initiating deposition temperature could be conducive to maintaining the mono-MoS2 template to support the subsequent growth of GaN. Compared to the control group of one-step high-temperature deposition at 320 °C, ideal layer-by-layer film growth is achieved at the low temperature of the two-step method instead of island formation, leading to the direct crystallization of GaN on the substrate with a rather sharp interface. Structural and chemical characterizations show that this two-step method produces a preferred [0001] orientation of the film originating from the interface region. Additionally, the improved two-step ultrathin GaN displays a smooth surface roughness as low as 0.58 nm, a low oxygen impurity concentration of 3.6%, and a nearly balanced Ga/N stoichiometry of 0.95:1. Our work paves a possible way to the feasible fabrication of ultrathin high-quality PEALD-GaN, and it is promising for better performance of relevant devices.

Research advances in myocardial injury caused by COVID-19.

Coronavirus disease 2019 (COVID-19) caused a large-scale infection in China at the end of 2019. The virus, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has the characteristics of strong transmission capacity, diverse clinical manifestations, long incubation period, strong infection in incubation period, etc. With the increase of the number of cases and the continuous improvement of clinical data, we found that patients with COVID-19 have myocardial injury besides typical respiratory system manifestations. According to published data, we summarized the clinical manifestations of myocardial injury in COVID-19 patients, and discussed the probable injury mechanism, treatment methods and future research directions.

Long non­coding RNA MALAT1 serves as an independent predictive biomarker for the diagnosis, severity and prognosis of patients with sepsis.

The present prospective study was conducted to investigate the independent risk and predictive value of plasma long non­coding RNA metastasis­associated lung adenocarcinoma transcript 1 (MALAT1) as a biomarker for the diagnosis, severity and prognosis of sepsis. A total of 120 patients with sepsis and 60 healthy controls (HCs) were recruited. The expression levels of plasma MALAT1 were detected by quantitative PCR. The results demonstrated that the plasma levels of MALAT1 were significantly increased in patients with sepsis compared with HCs (P<0.001), in patients with septic shock compared with in patients without septic shock (P<0.001), and in non­survivors compared with in survivors (P<0.001). MALAT1 plasma levels exhibited weak positive correlation with serum procalcitonin levels (r=0.253; P=0.005), arterial lactate levels (r=0.488; P<0.001), sepsis­related organ failure assessment scores (r=0.566; P<0.001), and acute physiology and chronic health evaluation II scores (r=0.517; P<0.001) in patients with sepsis. Multivariate logistic regression analysis revealed that high MALAT1 expression was an independent risk factor for sepsis (P<0.001), septic shock (P=0.030) and poor prognosis (P=0.015). In addition, the receiver operating characteristic curve exhibited a significant predictive value for MALAT1 in distinguishing patients with sepsis from HCs with an area under the curve (AUC) of 0.910, patients with septic shock from patients without shock with an AUC of 0.836, and non­survivors from survivors with an AUC of 0.886. In conclusion, plasma MALAT1 may serve as a biomarker for the diagnosis, severity and prognosis of sepsis.

A large-scale, ultrahigh-resolution nanoemitter ordered array with PL brightness enhanced by PEALD-grown AlN coating.

III-nitride solid-state microdisplays have significant advantages, including high brightness and high resolution, for the development of advanced displays, high-definition projectors, head-mounted displays, large-capacity optical communication systems, and so forth. Herein, a high-brightness InGaN/GaN multiple-quantum-well (MQW) nanoemitter array with an ultrahigh resolution of 31 750 dpi was achieved by combining a top-down fabrication with surface passivation of plasma-enhanced atomic layer deposition (PEALD)-grown AlN coating. With regard to the nanometer-level top-down etching, the surface damage or defects on the newly-formed sidewall play a significant role in the photoluminescence (PL) quality. Note that these arrays can be effectively passivated by the PEALD-grown AlN coating with an over 345% PL enhancement. In addition, a sharp band bending at the interface of the luminescent InGaN QW and the AlN coating layer can electrically drift away the photogenerated electrons from the surface traps; this leads to enhancement of the bulk PL radiative recombination with a fast PL decay rate. Therefore, we have demonstrated a feasible way for realizing an advanced nanoemitter array with both high brightness and ultrahigh resolution for future smart displays, high-resolution imaging, big-data optical information systems and so on.

Interfacial Tailoring for the Suppression of Impurities in GaN by In Situ Plasma Pretreatment via Atomic Layer Deposition.

A method for suppressing impurities in GaN thin films grown via plasma-enhanced atomic deposition (PEALD) through the in situ pretreatment of Si (100) substrate with plasma was developed. This approach leads to a superior GaN/Si (100) interface. After pretreatment, the thickness of the interfacial layer between GaN films and the substrates decreases from 2.0 to 1.6 nm, and the oxygen impurity content at the GaN/Si (100) interface reduces from 34 to 12%. The pretreated GaN films exhibit thinner amorphous transition GaN layer of 5.3 nm in comparison with those nonpretreated of 18.0 nm, which indicates the improvement of crystallinity of GaN. High-quality GaN films with enhanced density are obtained because of the pretreatment. This promising approach is considered to facilitate the growth of high-quality thin films via PEALD.

PEALD-Grown Crystalline AlN Films on Si (100) with Sharp Interface and Good Uniformity.

Aluminum nitride (AlN) thin films were deposited on Si (100) substrates by using plasma-enhanced atomic layer deposition method (PEALD). Optimal PEALD parameters for AlN deposition were investigated. Under saturated deposition conditions, the clearly resolved fringes are observed from X-ray reflectivity (XRR) measurements, showing the perfectly smooth interface between the AlN film and Si (100). It is consistent with high-resolution image of the sharp interface analyzed by transmission electron microscope (TEM). The highly uniform thickness throughout the 2-inch size AlN film with blue covered surface was determined by spectroscopic ellipsometry (SE). Grazing incident X-ray diffraction (GIXRD) patterns indicate that the AlN films are polycrystalline with wurtzite structure and have a tendency to form (002) preferential orientation with increasing of the thickness. The obtained AlN films could open up a new approach of research in the use of AlN as the template to support gallium nitride (GaN) growth on silicon substrates.

Extracting Complex Refractive Index from Polycrystalline Glucose with Self-Referenced Method for Terahertz Time-Domain Reflection Spectroscopy.

A self-referenced method for extracting the complex refractive index of material was proposed. The method utilized signals reflected from the front and rear surfaces of a slice sample as reference and sample signals, respectively. Before using the self-referenced method, a hybrid filtering technique for eliminating systematic and random noises of time-domain terahertz reflection spectroscopy was used. A terahertz reflection spectrum of crystalline glucose was measured and three feature absorption peaks were obtained from 0.2 to 2.0 THz. We suggest that intermolecular vibrational modes may contribute to the observed absorption spectra in the THz frequency range.