Large mode-field area multi-element silica glass fibers for gigahertz ultrafast lasers.

Multi-gigahertz ultrafast fiber lasers are critical for many significant applications, including bioimaging, optical communications, and laser frequency combs. The gain fiber which is expected to simultaneously satisfy large mode-field area, highly gain coefficient and resistance to photodarkening, will effectively protect mode-locked materials/devices that generally possesses low damage threshold (<10 mJ/cm2) and enhance stability in the centimeter-scale fiber lasers. However, the gain fiber still remains a significant challenge. In this study, multi-element Er-Yb: silica glass fibers with large mode-field area are fabricated. Benefiting from the multi-element design, normalized frequency V-parameter of the silica glass fiber with a core diameter of around 10 µm is <2.405. Using the large mode-field area fibers, ultrafast fiber lasers with 1.6 GHz fundamental repetition rate are proposed and demonstrated. The signal-to-noise rate of the radio-frequency signal reaching up to 90 dB and the long-term stability are realized. The results indicated the fabricated large mode-field area fibers are demonstrated to be ultrafast fiber lasers with short resonant cavities, which could be extended to other rare-earth glass fiber device for exploration of high-power amplification systems.

Supramolecular-Interactions-Modulated Photoluminescence in Indium Bromide-Based Isomers.

Here, two isomeric ionic zero-dimensional indium bromide crystals of α (1)/ß (2)-[OPy][InBr4(Phen)] (OPy = N-octylpyridinium; Phen = 1,10-phenanthroline) have been isolated simply by changing the cooling conditions in solvothermal syntheses. Structural comparisons indicate their different supramolecular interactions, which can be confirmed by Hirshfeld surface analyses. The crystal 2 has additional hydrogen bonds and π-π interactions; as a result, the more compact stacking of 2 could result in a 10-fold higher photoluminescence (PL) quantum yield (PLQY) than that of 1. Density functional theory calculations confirm the electron transition from the inorganic moiety to the organic ligand, which provides a further understanding of the optical process. This work provides a new idea for designing PL indium-based halides by understanding the structure-PL relationship.

Luminescence Enhancement and Temperature Sensing Properties of Hybrid Bismuth Halides Achieved via Tuning Organic Cations.

Bismuth-halide-based inorganic-organic hybrid materials (Bi-IOHMs) are desirable in luminescence-related applications due to their advantages such as low toxicity and chemical stability. Herein, two Bi-IOHMs of [Bpy][BiCl4(Phen)] (1, Bpy = N-butylpyridinium, Phen = 1,10-phenanthroline) and [PP14][BiCl4(Phen)]·0.25H2O (2, PP14 = N-butyl-N-methylpiperidinium), containing different ionic liquid cations and same anionic units, have been synthesized and characterized. Single-crystal X-ray diffraction reveals that compounds 1 and 2 crystallize in the monoclinic space group of P21/c and P21, respectively. They both possess zero-dimensional ionic structures and exhibit phosphorescence at room temperature upon excitation of UV light (375 nm for 1, 390 nm for 2), with microsecond lifetime (24.13 µs for 1 and 95.37 µs for 2). Hirshfeld surface analysis has been utilized to visually exhibit the different packing motifs and intermolecular interactions in 1 and 2. The variation in ionic liquids makes compound 2 have a more rigid supramolecular structure than 1, resulting in a significant enhancement in photoluminescence quantum yield (PLQY), that is, 0.68% for 1 and 33.24% for 2. In addition, the ratio of the emission intensities for compounds 1 and 2 shows a correlation with temperature. This work provides new insight into luminescence enhancement and temperature sensing applications involving Bi-IOHMs.

Reversible Luminescent Switching Induced by Heat/Water Treatment in a Zero-Dimensional Hybrid Antimony(â ¢) Chloride.

Recently zero-dimensional (0-D) inorganic-organic metal halides (IOMHs) have become a promising class of optoelectronic materials. Herein, we report a new photoluminescent (PL) 0-D antimony(III)-based IOMH single crystal, namely [H2BPZ][SbCl5]·H2O (BPZ = benzylpiperazine). Photophysical characterizations indicate that [H2BPZ][SbCl5]·H2O exhibits singlet/triplet dual-band emission. Density functional theory (DFT) calculations suggest that [H2BPZ][SbCl5]·H2O has the large energy difference between singlet and triplet states, which might induce the dual emission in this compound. Temperature-dependent PL spectra analyses suggest the soft lattice and strong electron-phonon coupling in this compound. Thermogravimetric analysis shows that the water molecules in the lattice of the title crystal could be removed by thermal treatment, giving rise to a dehydrated phase of [H2BPZ][SbCl5]. Interestingly, such structural transformation is accompanied by a reversible PL emission transition between red light (630 nm, dehydrated phase) and yellow light (595 nm, water-containing phase). When being exposed to an environment with 77% relative humidity, the emission color of the dehydrated phase was able to change from red to yellow within 20 s, and the red emission could be restored after reheating. The red to yellow emission switching could be achieved in acetone with water concentration as low as 0.2 vol%. The reversible PL transition phenomenon makes [H2BPZ][SbCl5]·H2O a potential material for luminescent water-sensing.

Immune response to hepatitis B vaccination in human immunodeficiency virus-positive patients in China: A 2-year retrospective study.

Currently, the studies focused on the immune response to hepatitis B vaccination in Chinese human immunodeficiency virus (HIV)-positive patients are limited. In this study, the participants with an initial hepatitis B surface antibody (HBsAb) titer <10 mIU/ml were assigned to Cohort 1 to receive a standard dose of recombinant hepatitis B vaccine, and participants with an initial HBsAb titer between 10 and 100 mIU/ml were assigned to Cohort 2 to receive a single reinforced recombinant vaccine. In Cohort 1, the immune and high response rates in HIV-positive patients were 93.4%/81.4%, 87.4%/51.5%, and 83.2%/40.7% at 1-3 months, 1 year, and 2 years postvaccination. Multivariate analysis showed that only age and HIV RNA status at baseline were independent factors related to sustained immune response at 2 years postvaccination. In Cohort 2, the high immune response rates in HIV-positive patients were 78.8%, 60.6%, and 51.5% at 1-3 months, 1 year, and 2 years postvaccination. The immune or high response rates did not differ between HIV-positive patients and healthy controls at 1-3 months postvaccination in these two cohorts; however, HBsAb titers were significantly lower in HIV-positive patients. This study summarized the 2-year data of immune response to hepatitis B vaccination and analyzed the factors related to sustained immune response at 2 years postvaccination in Chinese HIV-positive patients.

Probing Interactions between Metal-Organic Frameworks and Freestanding Enzymes in a Hollow Structure.

It has been reported that the biological functions of enzymes could be altered when they are encapsulated in metal-organic frameworks (MOFs) due to the interactions between them. Herein, we probed the interactions of catalase in solid and hollow ZIF-8 microcrystals. The solid sample with confined catalase is prepared through a reported method, and the hollow sample is generated by hollowing the MOF crystals, sealing freestanding enzymes in the central cavities of hollow ZIF-8. During the hollowing process, the samples were monitored by small-angle X-ray scattering (SAXS) spectroscopy, electron microscopy, powder X-ray diffraction (PXRD), and nitrogen sorption. The interfacial interactions of the two samples were studied by infrared (IR) and fluorescence spectroscopy. IR study shows that freestanding catalase has less chemical interaction with ZIF-8 than confined catalase, and a fluorescence study indicates that the freestanding catalase has lower structural confinement. We have then carried out the hydrogen peroxide degradation activities of catalase at different stages and revealed that the freestanding catalase in hollow ZIF-8 has higher activity.

Mixed-valence compounds based on heterometallic-oxo-clusters containing Sb(III,V): crystal structures and proton conduction.

Two isostructural Co(Cd)-antimony-oxo tartrate cluster-based compounds with a one-dimensional (1-D) belt-like structure, namely H9.2[Co(H2O)6]{M0.5(H2O)3.5{M'(H2O)4[SbVO6[Co4.2(H2O)5SbIII6(µ3-O)2(tta)6]]}}2·nH2O (M = Co, M' = Co, n = 9 (1); M = Cd0.39/Co0.61, M' = Cd0.24/Co0.76, n = 7 (2); H4tta = tartaric acid), have been synthesized by solvothermal methods. It is noteworthy that the relatively rare mixed-valence Sb(III,V) exists in the structures. The anionic clusters in both compounds appear to be in a sandwich configuration; the top and bottom layers are based on {Sb3(µ3-O)(tta)3} brackets, and the intermediate layer is occupied by {SbVO6[Co4.2(H2O)5]}. The title compounds have been characterized by single-crystal X-ray diffraction, powder X-ray diffraction, elemental analyses, thermogravimetric analyses, and UV-Vis spectroscopy. We chose compound 2 as a representative to test its proton conductivity, and the results show that the conductivity can reach 1.42 × 10-3 S cm-1 at 85 °C under 98% relative humidity.

Controlled Synthesis of Large-Area Oriented ZnO Nanoarrays.

Large-area oriented ZnO nanoarrays (including nanowire, nanorod, and nanotube) on ITO glass substrates are synthesized via the simple hydrothermal, electrodeposition, and electrochemical etching approach. The morphology of ZnO nanoarrays is controlled by adjusting the reaction temperature, reaction time, and current density. The scanning and transmission electron microscopy (SEM and TEM) results indicate the successful preparation of large-area oriented ZnO nanoarrays with different types, and the energy-dispersive X-microanalysis spectrum (EDS) and X-ray diffraction (XRD) results confirm that the composition of the obtained nanoarrays is ZnO. More importantly, the as-prepared ZnO nanotube arrays are observed with about a 40% increase in ultraviolet absorption intensity compared to the ZnO nanowire/nanorod arrays, due to having larger specific surface areas. The as-prepared different types of ZnO nanoarrays have great potential for applications in low-cost and high-performance optoelectronic devices.

Qingda granule alleviates cerebral ischemia/reperfusion injury by inhibiting TLR4/NF-κB/NLRP3 signaling in microglia.

ETHNOPHARMACOLOGICAL RELEVANCE: Qingda granule (QDG) is effective for treating hypertension and neuronal damage after cerebral ischemia/reperfusion. However, the anti-neuroinflammatory effect of QDG on injury due to cerebral ischemia/reperfusion is unclear. AIM OF THE STUDY: The objective was to evaluate the effectiveness and action of QDG in treating neuroinflammation resulting from cerebral ischemia/reperfusion-induced injury. MATERIALS AND METHODS: Network pharmacology was used to predict targets and pathways of QDG. An in vivo rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) as well as an in vitro model of LPS-stimulated BV-2 cells were established. Magnetic resonance imaging (MRI) was used to quantify the area of cerebral infarction, with morphological changes in the brain being assessed by histology. Immunohistochemistry (IHC) was used to assess levels of the microglial marker IBA-1 in brain tissue. Bioplex analysis was used to measure TNF-α, IL-1ß, IL-6, and MCP-1 in sera and in BV-2 cell culture supernatants. Simultaneously, mRNA levels of these factors were examined using RT-qPCR analysis. Proteins of the TLR4/NF-κB/NLRP3 axis were examined using IHC in vivo and Western blot in vitro, respectively. While NF-κB translocation was assessed using immunofluorescence. RESULTS: The core targets of QDG included TNF, NF-κB1, MAPK1, MAPK3, JUN, and TLR4. QDG suppressed inflammation via modulation of TLR4/NF-κB signaling. In addition, our in vivo experiments using MCAO/R rats demonstrated the therapeutic effect of QDG in reducing brain tissue infarction, improving neurological function, and ameliorating cerebral histopathological damage. Furthermore, QDG reduced the levels of TNF-α, IL-1ß, IL-6, and MCP-1 in both sera from MCAO/R rats and supernatants from LPS-induced BV-2 cells, along with a reduction in the expression of the microglia biomarker IBA-1, as well as that of TLR4, MyD88, p-IKK, p-IκBα, p-P65, and NLRP3 in MCAO/R rats. In LPS-treated BV-2 cells, QDG downregulated the expression of proinflammatory factors and TLR4/NF-κB/NLRP3 signaling-related proteins. Additionally, QDG reduced translocation of NF-κB to the nucleus in both brains of MCAO/R rats and LPS-induced BV-2 cells. Moreover, the combined treatment of the TLR4 inhibitor TAK242 and QDG significantly reduced the levels of p-P65, NLRP3, and IL-6. CONCLUSIONS: QDG significantly suppressed neuroinflammation by inhibiting the TLR4/NF-κB/NLRP3 axis in microglia. This suggests potential for QDG in treating ischemia stroke.

Synthesizing axial inserting p-n heterojunction nanowire arrays for realizing synergistic performance.

Consideration of the material design and components match on structure and energy, the solid-solid combined nanowires of p-type conductive polymer of poly[3-thiophene carboxylic acid methyl ester] (PTCM) and n-type inorganic semiconductor PbS was prepared with a 2.57 µm(2) heterojunction interface. The axial deeply inserting heterojunction nanowire arrays exhibited excellent rectifying features and diode nature, as well as obvious electrical switching behavior, which are much excelled individual components of PTCM and PbS nanowire arrays for realizing synergistic performance.

Clinical features and predictive factors related to liver injury in SARS-CoV-2 Delta and Omicron variant-infected patients.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta and Omicron variants have become the dominant variants worldwide, and studies focused on liver injury in these patients are limited. MATERIALS AND METHODS: In this study, 157 SARS-CoV-2-infected patients were enrolled, including 77 Delta variant-infected patients and 80 Omicron variant-infected patients. Liver injury data and clinical data were summarized and compared between patients infected with the two variants, additionally, patients with or without liver injury were also compared and multivariate analysis was performed to explore the predictive factors related to liver injury in SARS-CoV-2-infected patients. RESULTS: Liver injury was found in 18 (23.4%)/15 (18.8%) in Delta/Omicron variant-infected patients on admission, and 4 (5.2%)/1 (1.3%) in Delta/Omicron variant-infected patients during hospitalization, respectively. The ratios of liver injury did not differ between the two groups ( χ2 = 1.571; P = 0.210). Among these patients, 17 (77.3%) and 12 (75.0%) Delta and Omicron variant-infected patients were considered to be related to SARS-CoV-2 infection, the biomarkers of liver function were mildly elevated, dominated by the parameter of cholangiocyte injury: 76.5% (13/17) and 83.3% (10/12) in Delta and Omicron variant-infected patients, and most of these patients recovered to normal during follow-up. Multivariate analysis showed that male sex [odds ratio (OR), 4.476; 95% confidence interval (CI), 1.235-16.222; P = 0.023] and high levels of peak viral load in the nasopharynx (OR, 3.022; 95% CI, 1.338-6.827; P = 0.008) were independent factors related to liver injury. CONCLUSION: Cholangiocyte injury biomarkers are dominated in Delta and Omicron variant-infected patients, male sex and high levels of peak viral load in the nasopharynx are predictive factors related to liver injury in SARS-CoV-2-infected patients.

Advances in Self-Powered Ultraviolet Photodetectors Based on P-N Heterojunction Low-Dimensional Nanostructures.

Self-powered ultraviolet (UV) photodetectors have attracted considerable attention in recent years because of their vast applications in the military and civil fields. Among them, self-powered UV photodetectors based on p-n heterojunction low-dimensional nanostructures are a very attractive research field due to combining the advantages of low-dimensional semiconductor nanostructures (such as large specific surface area, excellent carrier transmission channel, and larger photoconductive gain) with the feature of working independently without an external power source. In this review, a selection of recent developments focused on improving the performance of self-powered UV photodetectors based on p-n heterojunction low-dimensional nanostructures from different aspects are summarized. It is expected that more novel, dexterous, and intelligent photodetectors will be developed as soon as possible on the basis of these works.

Constructing a blue light photodetector on inorganic/organic p-n heterojunction nanowire arrays.

We described a new structure photodetector, which is constructed by p-n heterojunction nanowire arrays of PANI (polyaniline)/CdS. The nanowire arrays exhibit excellent rectifying features and a diode nature and show a sensitive spectral response to blue light under 420 nm. The rectification ratio plots of different illumination intensities show straight line behavior, implying that the quantitative detection of illumination intensity can be achieved. The p-n heterojunction nanowire array is a great candidate for applications in high-sensitivity and high-speed blue light photodetectors.

Particle swarm optimized neural networks based local tracking control scheme of unknown nonlinear interconnected systems.

In this paper, a local tracking control (LTC) scheme is developed via particle swarm optimized neural networks (PSONN) for unknown nonlinear interconnected systems. With the local input-output data, a local neural network identifier is constructed to approximate the local input gain matrix and the mismatched interconnection, which are utilized to derive the LTC. To solve the local Hamilton-Jacobi-Bellman equation, a local critic NN is established to estimate the proper local value function, which reflects the mismatched interconnection. The weight vector of the local critic NN is trained online by particle swarm optimization, thus the success rate of system execution is increased. The stability of the closed-loop unknown nonlinear interconnected system is guaranteed to be uniformly ultimately bounded through Lyapunov's direct method. Simulation results of two examples demonstrate the effectiveness of the developed PSONN-based LTC scheme.

Characterization of the complete mitochondrial genome of the hybrid grouper (Cromileptes altivelis♀ × Epinephelus tukula♂) with phylogenetic consideration.

Here we isolated and characterized the complete mitochondrial genome of the hybrid grouper (Cromileptes altivelis♀ × Epinephelus tukula♂). It is 16,503 bp long and contains 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a control region. The nucleotide composition is 29.08% of A, 29.03% of C, 15.66% of G and 26.23% of T, with 55.31% A + T. The phylogenetic analysis by neighbor-joining (NJ) method reveals that the hybrid offspring has a closer relationship to C. altivelis.

Constructing a Green Light Photodetector on Inorganic/Organic Semiconductor Homogeneous Hybrid Nanowire Arrays with Remarkably Enhanced Photoelectric Response.

We demonstrate that a novel photodetector is constructed by CdS/poly( p-phenylene vinylene) (PPV) homogeneous hybrid nanowire arrays via a simple template-assisted electrochemical codeposition approach. Owing to the well-matched energy levels between CdS and PPV, the recombination of photogenerated electrons and holes in CdS/PPV hybrid nanowire arrays is greatly inhibited. It is found that the homogeneous hybrid nanowire arrays exhibit remarkably enhanced photoelectric response and the ON/OFF ratio by 17 times compared to the individual CdS component. More importantly, the CdS/PPV hybrid nanowire arrays are observed with significant spectral selectivity especially for green light under 545 nm. In addition, a straight linear relationship is obtained between the ON/OFF ratios and the illumination intensities, implying that the quantitative detection of illumination intensity can be achieved. The new as-prepared homogeneous hybrid organic/inorganic semiconductor nanowire arrays have a bright prospect for applications in high-sensitivity and high-speed green photodetectors.

Field emission and electrical bistable properties of CuTCPQ nanostructures.

The organic charge-transfer (CT) complex nanostructures of CuTCPQ (copper tetracyanopentacenequinodimethane) were first successfully fabricated by organic solid phase reaction. The morphologies of CuTCPQ nanosrods can be prepared by controlling the reaction temperature. The electron field-emission properties on these nanostructures were investigated. The current density and turn-on field are 3.5 mA cm(-2) and 2.70 V µm(-1) for the nanorods of CuTCPQ. The results demonstrate that the nanorods of CuTCPQ are potential candidates for field emission cathodes. Stable and reproducible current-controlled electrical switch has been observed in amorphous organic nanorods of CuTCPQ films. The current-voltage characteristics reveal an abrupt decrease in impedance form 1.2 MΩ to less than 1.1kΩ. The maximum ON/OFF ratio of CuTCPQ nanorod arrays is up to 1100.

Synthesis and characterization of axial heterojunction inorganic-organic semiconductor nanowire arrays.

The end-to-end P-N heterojunction nanowire arrays combined organic (poly[1,4-bis(pyrrol-2-yl)benzene], BPB) and inorganic (CdS) molecules have been successfully designed and fabricated. The electrical properties of P-N heterojunctions of organic-inorganic nanowire arrays were investigated. The diode nature and rectifying feature of P-N heterojunction nanowire arrays were observed. The rectification ratio of the diode increased from 29.9 to 129.7 as the illumination intensity increased. The material exhibits a new property, which is an improvement in the integration of the physical and chemical properties of the two independent components.

Controlling the growth of low dimension nanostructures of an iridium complex.

Controlling the fabrication of the nanowire-nanotube junctions of a dichloro-bridged dimeric iridium complex of 2-phenylpyridine (IPPC) has been achieved by a facile template method. IPPC nanowire-nanotube junctions were prepared at 15 °C, and IPPC nanotubes could be formed by increasing the temperature. It is interesting that IPPC solid nanowires were produced when the temperature decreased to 0 °C. The results show that temperature is a key factor for controlling the process of growth. The emission of the IPPC nanostructures showed a blue shift and a stronger intensity in comparison to IPPC bulk materials.

Construction of heterojunction nanowires from polythiophene/polypyrrole for applications as efficient switches.

The design and fabrication of PTh-PPY heterojunction nanowires that exhibits smart responses to electrochemical redox potentials is described. In their oxidized state, PTh-PPY nanowires act as resistors, whilst in their reduced state, they acts as diodes. Furthermore, the electrical transport mode can be reversibly changed by alternately exposing the nanowires to negative and positive potentials. Constructing full-organic heterojunction nanowires with smart, controllable properties will contribute to the development of intelligent organic devices and organic-electronic circuits on the nanoscale.