Regulation of band gap and localized surface plasmon resonance by loading Au nanorods on violet phosphene nanosheets for photodynamic/photothermal synergistic anti-infective therapy.

In the face of the serious threat to human health and the economic burden caused by bacterial antibiotic resistance, 2D phosphorus nanomaterials have been widely used as antibacterial agents. Violet phosphorus nanosheets (VPNSs) are an exciting bandgap-adjustable 2D nanomaterial due to their good physicochemical properties, yet the study of VPNS-based antibiotics is still in its infancy. Here, a composite of gold nanorods (AuNRs) loaded onto VPNS platforms (VPNS/AuNR) is constructed to maximize the potential of VPNSs for antimicrobial applications. The loading with AuNRs not only enhances the photothermal performance via a localized surface plasmon resonance (LSPR) effect, but also enhances the light absorption capacity due to the narrowing of the band gap of the VPNSs, thus increasing the ROS generation capacity. The results demonstrate that VPNS/AuNR exhibits outstanding antibacterial properties and good biocompatibility. Attractively, VPNS/AuNR is then extensively tested for treating skin wound infections, suggesting promising in vivo antibacterial and wound-healing features. Our findings may open a novel direction to develop a versatile VPNS-based treatment platform, which can significantly boost the progress of VPNS exploration.

Strong In-Plane Optoelectronic Anisotropy and Polarization Sensitivity in Low-Symmetry 2D Violet Phosphorus.

Anisotropic optoelectronics based on low-symmetry two-dimensional (2D) materials hold immense potential for enabling multidimensional visual perception with improved miniaturization and integration capabilities, which has attracted extensive interest in optical communication, high-gain photoswitching circuits, and polarization imaging fields. However, the reported in-plane anisotropic photocurrent and polarized dichroic ratios are limited, hindering the achievement of high-performance anisotropic optoelectronics. In this study, we introduce novel low-symmetry violet phosphorus (VP) with a unique tubular cross-linked structure into this realm, and the corresponding anisotropic optical and optoelectronic properties are investigated both experimentally and theoretically for the first time. Remarkably, our prepared VP-based van der Waals phototransistor exhibits significant optoelectronic anisotropies with a giant in-plane anisotropic photocurrent ratio exceeding 10 and a comparable polarized dichroic ratio of 2.16, which is superior to those of most reported 2D counterparts. Our findings establish VP as an exceptional candidate for anisotropic optoelectronics, paving the way for future multifunctional applications.

Would you choose to be a psychiatrist again? A large-sample nationwide survey of psychiatrists and psychiatry residents in China.

BACKGROUND: The mental health workforce sustainability in China suffers high rates of attrition and the intention to leave. Among current professionals, the intention to choose the same career is an interesting way to gauge their job satisfaction and other factors, and it may affect the career choices of younger generations. We aimed to survey the intention of psychiatrists and psychiatry residents to choose the same career if they could start over and to identify associated factors. METHODS: We conducted an anonymous survey of psychiatrists in 41 tertiary psychiatric hospitals in China. We collected demographic data, work-related information, the sense of professional identity, job satisfaction, and burnout (Maslach Burnout Inventory), and we specifically asked each participant whether they would choose to be a psychiatrist again if they could. RESULTS: Among 3,783 psychiatrists we surveyed, one-quarter responded that they would not choose to be a psychiatrist again if they had a choice, with less than half (47.2%) saying they would. Those who would not choose psychiatry again were more likely to have a negative (relative to positive) professional identity (OR = 7.47, P＜0.001, 95%CI: 4.587-12.164); experience job burnout (OR = 2.945, P＜0.001, 95%CI: 2.356-3.681); be dissatisfied with their job (OR = 2.739, P＜0.001, 95%CI: 2.102-3.569) and excessive regulation (OR = 1.819, P＜0.001, 95%CI: 1.487-2.226); have a heavy workload (OR = 1.749, P＜0.001, 95%CI: 1.423-2.149) or a lower income (OR = 1.748, P＜0.001, 95%CI: 1.415-2.161); be married (relative to single) (OR = 1.604, P = 0.004, 95%CI: 1.165-2.208); be dissatisfied with strained doctor-patient relationship (OR = 1.333, P = 0.005, 95%CI: 1.089-1.632); have more night shifts per month (OR = 1.055, P = 0.021, 95%CI: 1.008-1.104) or work longer hours per week (OR = 1.016, P = 0.001, 95%CI: 1.006-1.025). CONCLUSION: Among psychiatrists in tertiary hospitals in China, those with a heavier workload, poor sense of professional identity, job dissatisfaction, and burnout were less likely to choose psychiatry again. Policymakers and hospital administrators need to take effective measures to improve psychiatrists' sense of professional identity and increase their intention to stay.

Dexmedetomidine alleviates ferroptosis following hepatic ischemia-reperfusion injury by upregulating Nrf2/GPx4-dependent antioxidant responses.

Hepatic ischemia-reperfusion injury (HIRI) adversely affects liver transplant and resection outcomes. Recently, ferroptosis has been associated with HIRI. Dexmedetomidine (Dex), a potent sedative with anti-inflammatory, antioxidant, and anti-apoptotic properties, protects organs from hypoxic or ischemia-reperfusion (I/R) injuries. However, the mechanisms underlying this protective effect against I/R-induced liver injury remain unclear. This study evaluated the effect of Dex on HIRI in mouse models and the oxygen-glucose deprivation/reperfusion (OGD/R) AML12 cell model. We examined ferroptosis-related markers, including Fe2+ levels, reactive oxygen species (ROS) content, mitochondrial morphology, GPX4 protein expression, 4-hydroxynonenal (4-HNE), and Nrf2. The Nrf2 inhibitor ML385 was used in combination with Dex to treat HIRI mice and OGD/R-induced cellular models to explore the pathways by which Dex counteracts ferroptosis. Our results showed that Dex treatment significantly ameliorated OGD/R-induced ferroptosis in AML12 cells, including reduced Fe2+, ROS, malondialdehyde (MDA), and 4-HNE levels. Dex also ameliorated liver tissue damage and reduced serum AST, ALT, and inflammatory factor levels in HIRI mice. Additionally, Dex increased the levels of GSH, an antioxidative stress marker, and GPX4 expression in HIRI mice. Mechanistically, Nrf2 expression and nuclear translocation were significantly inhibited in both HIRI mice and OGD/R-treated AML12 cells. Dex treatment also restored the I/R-induced inhibition of Nrf2 expression and nuclear translocation. ML385 significantly inhibited Dex-promoted Nrf2 nuclear aggregation with Gpx4 protein expression, hindering the efficacy of Dex. In conclusion, Dex ameliorates ferroptosis in HIRI by positively regulating the Nrf2/GPx4 axis, potentially presenting a therapeutic avenue for addressing HIRI.

Electromechanical behaviour of violet phosphorene nanoflakes.

Violet phosphorene (vP), a two-dimensional structure with various unique properties, has attracted much attention recently. The electromechanical behaviour, a mechanical-electrical-thermal coupling failure behaviour, of supported and suspended vP nanoflakes has been investigated by the c-AFM nanoindentation method under different loads and bias voltages in this work. A bump due to the oxidation caused by electric current-induced local heating was observed for the supported vP on substrates under mild load and bias voltage. A concave morphology was observed when a load of 1500 nN and a bias voltage of 10 V were applied. No bump was observed for the suspended vP due to the larger contact area between the probe and the sample, resulting in a lower temperature. Fatigue damage was observed for the vP nanoflakes under constant load and a cycled bias voltage from 10 V to -10 V. The electromechanical behaviour of vP was also analyzed through its specific heat capacity and conductivity by density functional theory.

Synthesis of violet phosphorus with large lateral sizes to facilitate nano-device fabrications.

Violet phosphorus has been proven to be the most stable phosphorus allotrope and has attracted much attention recently. The growth of violet phosphorus with large lateral sizes is crucial to obtain good quality violet phosphorene for nanodevice fabrication. Herein, a large number of violet phosphorus plates have been produced from molten lead using an optimized method to achieve red bronze luster. The crystal structure of the as-produced violet phosphorus was determined by single-crystal X-ray diffraction to be monoclinic with the space group P2/n (13) (CSD-2160375), identical to the one from the chemical vapor transport method (CSD-1935087). The as-produced violet phosphorus plates were found to have lateral sizes of 1.30 ± 0.41 mm2. The violet phosphorus plates were easily exfoliated and directly transferred to silicon substrates to facilitate building of a back-gate field-effect transistor. A hole mobility of 2.308 cm2 V-1 s-1 was obtained from a violet phosphorus nanosheet with a thickness of 52 nm under ambient conditions. The absolute responsivity of 130 mA W-1 with a fast response time of 27 ms was also obtained under the irradiation of a 530 nm laser.

[Progress on the researches of acupuncture preconditioning before surgery].

This paper reviews the researches on acupuncture preconditioning before surgery in recent years and explores its application value from three aspects, i.e. relieving preoperative anxiety, preventing from postoperative cognitive dysfunction, and preventing from postoperative gastrointestinal dysfunction. As a relatively safe non-drug treatment, acupuncture has the underlying advantages in participating into multidisciplinary coordination in the enhanced recovery after surgery (ERAS). By building up higher-quality medical evidences and revealing the effect mechanism of acupuncture from multi-dimenisonal aspects, it is expected that acupuncture technology can be coordinated with ERAS to optimize the clinical path in the perioperative period, and boost the development of the perioperative medicine ultimately.

Violet Antimony Phosphorus with Enhanced Photocatalytic Hydrogen Evolution.

Violet phosphorus (VP), a recently confirmed layered elemental structure, is demonstrated to have unique photoelectric, mechanical, and photocatalytic properties. Element substitution plays a significant role in modifying the physical/chemical properties of semiconducting materials. Herein, antimony is adopted to substitute some phosphorus atoms in VP crystals to tune their physical and chemical properties, resulting in a significantly enhanced photocatalytic hydrogen evolution performance. The antimony-substituted violet phosphorus single crystal (VP-Sb) is synthesized and characterized by single crystal X-ray diffraction (CSD-2214937). The bandgap of VP-Sb has been found to be lowered from that of VP by UV/vis diffuse reflectance spectroscopy and density-functional theory (DFT) calculation, enhancing the optical absorption during photocatalytic reaction. The conducting band minimum of VP-Sb is found to be upshifted from that of VP from measurements and calculation, enhancing its hydrogen reduction activity. The valance band maximum is found to be lowered to weaken its oxidation activity. The edge of VP-Sb is calculated to have an excellent H* adsorption-desorption performance and superior H2 generation kinetics. The H2 evolution rate of VP-Sb is demonstrated to be significantly enhanced to be 1473 µmol h-1 g-1 , about five times of that of pristine VP (299 µmol h-1 g-1 ) under the same experimental conditions.

A Review of Phosphorus Structures as CO2 Reduction Photocatalysts.

Effective photocatalytic carbon dioxide (CO2 ) reduction into high-value-added chemicals is promising to mitigate current energy crisis and global warming issues. Finding effective photocatalysts is crucial for photocatalytic CO2 reduction. Currently, metal-based semiconductors for photocatalytic CO2 reduction have been well reviewed, while review of nonmetal-based semiconductors is almost limited to carbon nitrides. Phosphorus is a promising nonmetal photocatalysts with various allotropes and tunable band gaps, which has been demonstrated to be promising non-metallic photocatalysts. However, no systematic review about phosphorus structures for photocatalytic CO2 reduction reactions has been reported. Herein, the progresses of phosphorus structures as photocatalysts for CO2 reduction are reviewed. The fundamentals of photocatalytic CO2 reduction, corresponding properties of phosphorus allotropes, photocatalysts with phosphorus doping or phosphorus-containing ligands, research progress of phosphorus allotropes as photocatalysts for CO2 reduction have been reviewed in this paper. The future research and perspective of phosphorus structures for photocatalytic CO2 reduction are also presented.

Violet phosphorus: an effective metal-free elemental photocatalyst for hydrogen evolution.

Violet phosphorus, a non-metallic elemental layered structure, has not been reported as a photocatalyst due to the lack of its resources. An excellent photocatalytic H2 evolution rate of 675 ± 109 µmol h-1 g-1 with high stability has been achieved by the violet phosphorus simply dispersed in deionized water with addition of 1.0 wt% of co-catalyst Pt, which is much higher than that obtained from black phosphorus. The H2 evolution rate was observed to reach values as high as 553 µmol h-1 g-1 with addition of 0.5 wt% co-catalyst Pt.

Structure and Properties of Violet Phosphorus and Its Phosphorene Exfoliation.

Black phosphorene has attracted much attention as a semiconducting two-dimensional material. Violet phosphorus is another layered semiconducting phosphorus allotrope with unique electronic and optoelectronic properties. However, no confirmed violet crystals or reliable lattice structure of violet phosphorus had been obtained. Now, violet phosphorus single crystals were produced and the lattice structure has been obtained by single-crystal x-ray diffraction to be monoclinic with space group of P2/n (13) (a=9.210, b=9.128, c=21.893 Å, ß=97.776°). The lattice structure obtained was confirmed to be reliable and stable. The optical band gap of violet phosphorus is around 1.7 eV, which is slightly larger than the calculated value. The thermal decomposition temperature was 52 °C higher than its black phosphorus counterpart, which was assumed to be the most stable form. Violet phosphorene was easily obtained by both mechanical and solution exfoliation under ambient conditions.

Biological characterisation and application of human MTH1 and monoclonal antibody preparation.

Human MutT homolog 1 (MTH1) hydrolyses oxidised nucleotide triphosphates, thereby preventing them from being incorporated into DNA; MTH1 has been found to be elevated in many types of cancers, including lung, stomach cancer, melanoma and breast cancer. Thus, tumour­targeted hMTH1 may be valuable for developing novel anticancer therapies. In the present study, we prepared human MTH1 protein and its monoclonal antibody (mAb). The hMTH1 gene was cloned into the prokaryotic expression vector pET28a and optimally expressed in the E. coli Transetta (DE3) strain. Using an Ni­NTA column and a G­50 gel filtration column, 20.1 mg of active hMTH1 was obtained from 1,000 ml of bacterial culture, and the purity was over 98%, as detected by high­performance liquid chromatography (HPLC). The half maximal inhibitory concentration (IC50) of TH287 (hMTH1 inhibitor) was determined to be 3.53±0.47 nM using the recombinant hMTH1 protein (rhMTH1). The enzyme activity assay showed the Michaelis constant (Km) and the catalytic constant (kcat) of the protein were 106.13±48.83 µM and 3.64±0.58 sec­1, respectively. The anti­hMTH1 mAb was obtained via the hybridoma technique and validated by western blot analysis. In addition, an immunofluorescence assay (IFA) and ELISA determined that the mAb could efficiently bind to natural hMTH1 expressed on the human breast cancer cell line MCF­7. Taken together, the results showed the rhMTH1 is an active protein and has practical applications for inhibitor selection, and our prepared hMTH1 mAb will provide a valuable tool for the further characterisation of hMTH1 and antitumour medicinal development in future.