Selective Integrating Molecular Catalytic Units into Bipyridine-Based Covalent Organic Frameworks for Specific Photocatalytic Fuel Production.

Molecular metal compounds have demonstrated excellent catalytic activity and product selectivity in the H2 evolution reaction (HER) and the CO2 reduction reaction (CO2RR). The heterogenization of molecular catalysts is regarded as an effective approach to improve their applicability. In this work, the molecular catalytic units [Cp*Ir(Bpy)Cl]+ and [Ru(Bpy)(CO)2Cl2] are constructed in situ on the bipyridine sites of the covalent organic framework for photocatalytic HER and CO2RR, respectively. Inheriting the impressive performance of molecular catalysts, the functionalized TpBpy-M exhibits excellent catalytic activity and product selectivity. Under visible light irradiation, the H2 production rate of TpBpy-Ir is about 760 µmol g-1 h-1, which is 6.7 times higher than that of TpBpy without built-in catalytic sites. Also, the HCOOH production rate of TpBpy-Ru is 271 µmol g-1 h-1, with an impressive selectivity of 88%. Control experiments validated that this improvement is attributed to the incorporation of molecular catalytic units into the framework. Photoluminescence spectroscopy measurements and theoretical calculation consistently demonstrate that, under illumination, the photosensitizer [Ru(Bpy)3]Cl2 is excited and transfers electrons to the catalytic sites in TpBpy-M, which then catalyzes the reduction of H+ and CO2.

Polysaccharide-Based Coating with Excellent Antibiofilm and Repeatable Antifouling-Bactericidal Properties for Treating Infected Hernia.

In recent years, the utilization of medical devices has gradually increased and implantation procedures have become common treatments. However, patients are susceptible to the risk of implant infections. This study utilized chemical grafting to immobilize polyethylenimine (QPEI) and hyaluronic acid (HA) on the surface of the mesh to improve biocompatibility while being able to achieve antifouling antimicrobial effects. From the in vitro testing, PP-PDA-Q-HA exhibited a high antibacterial ratio of 93% against S. aureus, 93% against E. coli, and 85% against C. albicans. In addition, after five rounds of antimicrobial testing, the coating continued to exhibit excellent antimicrobial properties; PP-PDA-Q-HA also inhibits the formation of bacterial biofilms. In addition, PP-PDA-Q-HA has good hemocompatibility and cytocompatibility. In vivo studies in animal implantation infection models also demonstrated the excellent antimicrobial properties of PP-PDA-Q-HA. Our study provides a promising strategy for the development of antimicrobial surface medical materials with excellent biocompatibility.

Regulating the Content of Donor Unit in Donor-Acceptor Covalent Triazine Frameworks for Promoting Photocatalytic H2 Production.

Using their own triazine groups as natural receptors, the introduction of various donor units to construct donor-receptor configuration in covalent triazine frameworks (CTFs) has been shown to be an effective strategy to improve photocatalytic activity. In this work, the effect of donor unit content (D-content) on the photoelectric properties and photocatalytic activity of CTFs was thoroughly investigated. Four analogous CTFs with different D-content have been rationally designed and synthesized, in which the bithiophene (Btp) as the donor unit and triazine as the acceptor unit. And CTF-Btp with the highest D-content showed the best photocatalytic activity. The experimental and theoretical results indicated this improvement is attributed to stronger visible light absorption capacity and higher photoinduced charge carrier separation efficiency. This study elucidates the relationship between the structural features of CTFs with varying D-content and their photocatalytic activity, offering a promising strategy for developing efficient photocatalysts.

Intestinal tuberculosis presented as spindle cell pseudotumor in a HIV-positive case / Tuberculosis intestinal presentada como pseudotumor de células fusiformes en un caso VIH positivo

MSP is a rare and atypical form of benign granulomatous inflammation characterised by tumour-like local proliferation of spindle-shaped histiocytes containing acid-fast positive mycobacteria, which should be differentiated from neoplastic lesions. A 26-year-old Chinese man complained an intermittent and mild right lower abdominal pain for 5 months in May 2022.Histopathology of biopsy samples showed Mycobacterial spindle cell pseudotumor (MSP). The test of Mycobacterium tuberculosis detected by polymerase chain reaction using intestinal tissue slice was negative. The metagenomic next-generation sequencing (BGI-Shenzhen) using formalin-fixation and paraffin-embedded intestine samples confirmed Mycobacterium tuberculosis complex (MTBC).(AU)

Treatment of rheumatoid arthritis with curcumin analog 3,5-bis(arylidene)-4-piperidone.

Rheumatoid arthritis (RA) is an inflammatory disease. Curcumin can inhibit NF-κB and reduce the expression of inflammation-related genes. Aim: To evaluate the potential development of 6d in the clinical treatment of inflammatory diseases such as RA. Methods: Using a skeleton fusion strategy to synthesize curcumin analogues for 6d. This work evaluates anti-inflammatory activity by conducting anti-arthritis experiments (adjuvant-induced RA models) on rats. Western blot and ELISA were used to detect the expression of inflammatory-related proteins and cytokines. Molecular docking analysis confirmed the binding effect of 6d with active sites. Conclusion: 6d inhibits NF-κB has a protective effect on arthritis caused by RA.

Neuroprotective Effects of Leptin on the APP/PS1 Alzheimer's Disease Mouse Model: Role of Microglial and Neuroinflammation.

Background: Microglia are closely linked to Alzheimer's disease (AD) many years ago; however, the pathological mechanisms of AD remain unclear. The purpose of this study was to determine whether leptin affected microglia in the hippocampus of young and aged male APP/PS1 mice. Objective: In a transgenic model of AD, we investigated the association between intraperitoneal injection of leptin and microglia. Methods: We intraperitoneal injection of leptin (1mg/kg) every day for one week and analyzed inflammatory markers in microglia in the hippocampus of adult (6 months) and aged (12 months) APP/PS1 mice. Results: In all leptin treatment group, the brain Aß levels were decrease. We found increased levels of IL-1ß, IL-6 and microglial activation in the hippocampus of adult mice. Using aged mice as an experimental model for chronic neuroinflammation and leptin resistance, the number of Iba-1+ microglia and the levels of IL-1ß/IL-6 in the hippocampus were greatly increased as compared to the adult. But between the leptin treatment and un-treatment, there were no difference. Conclusion: Leptin signaling would regulate the activation of microglia and the release of inflammatory factors, but it is not the only underlying mechanism in the neuroprotective effects of AD pathogenesis.

Mn(iii)-mediated C-P bond activation of diphosphines: toward a highly emissive phosphahelicene cation scaffold and modulated circularly polarized luminescence.

Transition metal mediated C-X (X = H, halogen) bond activation provides an impressive protocol for building polyaromatic hydrocarbons (PAHs) in C-C bond coupling and annulation; however, mimicking both the reaction model and Lewis acid mediator simultaneously in a hetero-PAH system for selective C-P bond cleavage faces unsolved challenges. At present, developing the C-P bond activation protocol of the phosphonic backbone using noble-metal complexes is a predominant passway for the construction of phosphine catalysts and P-center redox-dependent photoelectric semiconductors, but non-noble metal triggered methods are still elusive. Herein, we report Mn(iii)-mediated C-P bond activation and intramolecular cyclization of diphosphines by a redox-directed radical phosphonium process, generating phosphahelicene cations or phosphoniums with nice regioselectivity and substrate universality under mild conditions. Experiments and theoretical calculations revealed the existence of the unusual radical mechanism and electron-deficient character of novel phosphahelicenes. These rigid quaternary bonding skeletons facilitated versatile fluorescence with good tunability and excellent efficiency. Moreover, the enantiomerically enriched crystals of phosphahelicenes emitted intense circularly polarized luminescence (CPL). Notably, the modulated CPL of racemic phosphahelicenes was induced by chiral transmission in the cholesteric mesophase, showing ultrahigh asymmetry factors of CPL (+0.51, -0.48). Our findings provide a new approach for the design of emissive phosphahelicenes towards chiral emitters and synthesized precursors.

Effect of Grain Structure and Quenching Rate on the Susceptibility to Exfoliation Corrosion in 7085 Alloy.

The influence of grain structure and quenching rates on the exfoliation corrosion (EXCO) susceptibility of 7085 alloy was studied using immersion tests, optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and scanning transmission electron microscopy (STEM). The results show that as the cooling rate decreases from 1048 °C/min to 129 °C/min; the size of grain boundary precipitates (GBPs); the width of precipitate-free zones (PFZ); and the content of Zn, Mg, and Cu in GBPs rise, leading to an increase in EXCO depth and consequently higher EXCO susceptibility. Meanwhile, there is a linear relationship between the average corrosion depth and the logarithm of the cooling rate. Corrosion cracks initiate at the grain boundaries (GBs) and primarily propagate along the HAGBs. In the bar grain (BG) sample at lower cooling rates, crack propagation along the sub-grain boundaries (SGBs) was observed. Compared to equiaxed grain (EG) samples, the elongated grain samples exhibit larger GBPs, a wider PFZ, and minor compositional differences in the GBPs, resulting in higher EXCO susceptibility.

Decarboxylation of ß-boryl NHPI esters enables radical 1,2-boron shift for the assembly of versatile organoborons.

In recent years, numerous 1,2-R shift (R = aliphatic or aryl) based on tetracoordinate boron species have been well investigated. In the contrary, the corresponding radical migrations, especially 1,2-boryl radical shift for the construction of organoborons is still in its infancy. Given the paucity and significance of such strategies in boron chemistry, it is urgent to develop other efficient and alternative synthetic protocols to enrich these underdeveloped radical 1,2-boron migrations, before their fundamental potential applications could be fully explored at will. Herein, we have demonstrated a visible-light-induced photoredox neutral decarboxylative radical cross-coupling reaction, which undergoes a radical 1,2-boron shift to give a translocated C-radical for further capture of versatile radical acceptors. The mild reaction conditions, good functional-group tolerance, and broad ß-boryl NHPI esters scope as well as versatile radical acceptors make this protocol applicable in modification of bioactive molecules. It can be expected that this methodology will be a very useful tool and an alternative strategy for the construction of primary organoborons via a novel radical 1,2-boron shift mode.

Low complexity joint clock recovery and adaptive equalization based on a baud-rate timing phase error detector for short-reach digital coherent transmission.

Digital coherent receivers adopting joint clock recovery and adaptive equalization (JCA) can avoid failures of the adaptive equalizer (AEQ) or clock recovery algorithm (CRA) due to clock asynchrony and chromatic dispersion (CD). But in the previous JCA scheme, the AEQ has a heavy computational load as it has to generate two samples per symbol (SPS) for the subsequent timing phase error detector (TPED) which is the core of the CRA. Furthermore, the previous JCA scheme cannot compensate for receiver skew or accommodate Nyquist signals with small roll-off factors (ROFs). These shortcomings hinder its practical applications in ultrahigh-speed short-reach coherent transmission requiring low power consumption, high spectral efficiency, whilst being sensitive to receiver skew. To solve this problem, we propose a new JCA scheme by integrating a two-section real-valued (RV) AEQ with an all-digital feedback CRA based on a baud-rate TPED versatile for different ROFs. Experiments for 61-GBaud dual-polarization (DP) Nyquist 16QAM signals with an ROF of 0.01 show that, compared with the previous JCA scheme, the proposed scheme can reduce the AEQ computational load by about 70% for 10-km transmission, whilst improving the receiver sensitivity by more than 1.7 dB for a receiver skew of 1.5 ps. As far as we know, the proposed JCA scheme is the most comprehensive and efficient solution for ultrahigh-speed short-reach coherent transmission where CD, receiver skew, clock asynchrony, and Nyquist signals with small ROFs have to be dealt with.

Surface passivation for highly active, selective, stable, and scalable CO2 electroreduction.

Electrochemical conversion of CO2 to formic acid using Bismuth catalysts is one the most promising pathways for industrialization. However, it is still difficult to achieve high formic acid production at wide voltage intervals and industrial current densities because the Bi catalysts are often poisoned by oxygenated species. Herein, we report a Bi3S2 nanowire-ascorbic acid hybrid catalyst that simultaneously improves formic acid selectivity, activity, and stability at high applied voltages. Specifically, a more than 95% faraday efficiency was achieved for the formate formation over a wide potential range above 1.0 V and at ampere-level current densities. The observed excellent catalytic performance was attributable to a unique reconstruction mechanism to form more defective sites while the ascorbic acid layer further stabilized the defective sites by trapping the poisoning hydroxyl groups. When used in an all-solid-state reactor system, the newly developed catalyst achieved efficient production of pure formic acid over 120 hours at 50 mA cm-2 (200 mA cell current).

Embryonic perfect repair inspired electrospun nanofibers dressing with temperature-sensitive and antibacterial properties for wound healing.

Introduction: The development of highly effective wound dressings is crucial for successful clinical applications. Achieving wound closure, preventing infection, and minimizing scarring are key objectives in wound healing. Drawing inspiration from the regenerative mechanisms observed in embryonic tissue repair, we designed a series of wound-contractible dressings with exceptional antibacterial properties. Methods: This was achieved by encapsulating quaternized silicone (QP12) and poly(N-isopropylacrylamide-co-N-hydroxymethylacrylamide-co-octadecyl acrylate) (PNNS) within electrospun nanofibers of poly(ε-caprolactone) (PCL). Results and discussion: The resulting nanofibrous dressings demonstrated remarkable thermo-responsive self-contraction and tissue adhesion capabilities, enabling secure adherence to the skin and active wound closure. Notably, these nanofibers exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. Furthermore, they possessed desirable properties such as hydrophilicity, biocompatibility and mechanical properties resembling human skin. A full-thickness skin defect model evaluation revealed that these temperature-sensitive nanofibers expedited wound closure, enhanced wound healing, and suppressed scar formation. This result was evidenced by reduced infiltration of inflammatory cells, well-organized collagen arrangement, and improved vascularization. In summary, we propose that these wound-contractible nanofibers, with their antibacterial and anti-scarring properties, hold great promise as an advanced solution for skin wound repair.

Thermal Deformation Behavior and Dynamic Softening Mechanisms of Zn-2.0Cu-0.15Ti Alloy: An Investigation of Hot Processing Conditions and Flow Stress Behavior.

Through isothermal hot compression experiments at various strain rates and temperatures, the thermal deformation behavior of Zn-2.0Cu-0.15Ti alloy is investigated. The Arrhenius-type model is utilized to forecast flow stress behavior. Results show that the Arrhenius-type model accurately reflects the flow behavior in the entire processing region. The dynamic material model (DMM) reveals that the optimal processing region for the hot processing of Zn-2.0Cu-0.15Ti alloy has a maximum efficiency of about 35%, in the temperatures range (493-543 K) and a strain rate range (0.01-0.1 s-1). Microstructure analysis demonstrates that the primary dynamic softening mechanism of Zn-2.0Cu-0.15Ti alloy after hot compression is significantly influenced by temperature and strain rate. At low temperature (423 K) and low strain rate (0.1 s-1), the interaction of dislocations is the primary mechanism for the softening Zn-2.0Cu-0.15Ti alloys. At a strain rate of 1 s-1, the primary mechanism changes to continuous dynamic recrystallization (CDRX). Discontinuous dynamic recrystallization (DDRX) occurs when Zn-2.0Cu-0.15Ti alloy is deformed under the conditions of 523 K/0.1 s-1, while twinning dynamic recrystallization (TDRX) and CDRX are observed when the strain rate is 10 s-1.

Time-domain low-complexity clock recovery for non-integer oversampled Nyquist signals with a small roll-off factor.

A clock recovery algorithm (CRA) suitable for non-integer oversampled Nyquist signals with a small roll-off factor (ROF) is appealing to short-reach high-speed inter-datacenter transmission systems which need to cut down the transceiver power consumption and cost by reducing the oversampling factor (OSF) and using cheap low-bandwidth components. However, due to the lack of a suitable timing phase error detector (TPED), CRAs proposed now fail for non-integer OSFs below two and small ROFs close to zero and are not hardware-efficient. To solve these problems, we propose a low-complexity TPED by modifying the time-domain quadratic signal and reselecting the synchronization spectral component. We demonstrate that the proposed TPED, in combination with a piece-wise parabolic (PWP) interpolator, can significantly improve the performance of feedback CRAs for non-integer oversampled Nyquist signals with a small ROF. Numerical simulations and experiments show that, based on the improved CRA, the receiver sensitivity penalty can keep below 0.5 dB when the OSF is reduced from 2 to 1.25 and the ROF is varied from 0.1 to 0.001 for 45 GBaud dual-polarization Nyquist 16QAM signals.

Multifunctional xyloglucan-containing electrospun nanofibrous dressings for accelerating infected wound healing.

Preventing wound infection is a major challenge in biomedicine. Conventional wound dressings often have poor moisturizing and antimicrobial properties unfavorable for wound healing. In this study, we prepared a multifunctional electrospun nanofiber dressing (PCQX-M) containing xyloglucan, quaternized chitosan, Polyvinyl alcohol, and collagen. By applying the concept of wet healing, xyloglucan and quaternized chitosan polysaccharides with excellent water solubility were employed to improve the absorption and moisturizing properties and maintain a moist microenvironment for the wound healing process. PCQX-M demonstrated high mechanical, thermodynamic, and biocompatible properties, providing suitable healing conditions for wounds. In addition, PCQX-M showed exceptional antibacterial properties and a potential inhibitory effect on the growth of microorganisms in infected wounds. More intriguingly, the restorative healing effect was investigated on a mouse model of whole skin injury infected with Staphylococcus aureus. Wound healing, collagen deposition, and immunofluorescence results showed that PCQX-M significantly promoted cell proliferation and angiogenesis at the injury site and facilitated the healing of the infected wound. Our study suggests that PCQX-M has excellent potential for clinical application in infected wound healing.

Applications of Metal-Organic Frameworks and Their Derivatives in Electrochemical CO2 Reduction.

Electrochemically reducing CO2 to more reduced chemical species is a promising way that not only enables the conversion of intermittent energy resources to stable fuels, but also helps to build a closed-loop anthropogenic carbon cycle. Among various electrocatalysts for electrochemical CO2 reduction, multifunctional metal-organic frameworks (MOFs) have been employed as highly efficient and selective heterogeneous electrocatalysts due to their ultrahigh porosity and topologically diverse structures. Up to now, great progress has been achieved in the design and synthesis of highly active and selective MOF-related catalysts for electrochemical CO2 reduction reaction (CO2RR), and their corresponding reaction mechanisms have been thoroughly studied. In this review, we summarize the recent progress of applying MOFs and their derivatives in CO2RR, with a focus on the design strategies for electrocatalysts and electrolyzers. We first discussed the reaction mechanisms for different CO2RR products and introduced the commonly applied electrolyzer configurations in the current CO2RR system. Then, an overview of several categories of products (CO, HCOOH, CH4, CH3OH, and multi-carbon chemicals) generated from MOFs or their derivatives via CO2RR was discussed. Finally, we offer some insights and perspectives for the future development of MOFs and their derivatives in electrochemical CO2 reduction. We aim to provide new insights into this field and further guide future research for large-scale applications.

Self-Healing Hydrogels Fabricated by Introducing Antibacterial Long-Chain Alkyl Quaternary Ammonium Salt into Marine-Derived Polysaccharides for Wound Healing.

The development of hydrogels as wound dressings has gained considerable attention due to their promising ability to promote wound healing. However, in many cases of clinical relevance, repeated bacterial infection, which might obstruct wound healing, usually occurs due to the lack of antibacterial properties of these hydrogels. In this study, we fabricated a new class of self-healing hydrogel with enhanced antibacterial properties based on dodecyl quaternary ammonium salt (Q12)-modified carboxymethyl chitosan (Q12-CMC), aldehyde group- modified sodium alginate (ASA), Fe3+ via Schiff bases and coordination bonds (QAF hydrogels). The dynamic Schiff bases and coordination interactions conferred excellent self-healing abilities to the hydrogels, while the incorporation of dodecyl quaternary ammonium salt gave the hydrogels superior antibacterial properties. Additionally, the hydrogels displayed ideal hemocompatibility and cytocompatibility, crucial for wound healing. Our full-thickness skin wound studies demonstrated that QAF hydrogels could result in rapid wound healing with reduced inflammatory response, increased collagen disposition and improved vascularization. We anticipate that the proposed hydrogels, possessing both antibacterial and self-healing properties, will emerge as a highly desirable material for skin wound repair.

Intestinal tuberculosis presented as spindle cell pseudotumor in a HIV-positive case.

MSP is a rare and atypical form of benign granulomatous inflammation characterised by tumour-like local proliferation of spindle-shaped histiocytes containing acid-fast positive mycobacteria, which should be differentiated from neoplastic lesions. A 26-year-old Chinese man complained an intermittent and mild right lower abdominal pain for 5 months in May 2022.Histopathology of biopsy samples showed Mycobacterial spindle cell pseudotumor (MSP). The test of Mycobacterium tuberculosis detected by polymerase chain reaction using intestinal tissue slice was negative. The metagenomic next-generation sequencing (BGI-Shenzhen) using formalin-fixation and paraffin-embedded intestine samples confirmed Mycobacterium tuberculosis complex (MTBC).

A nanofiber/sponge double-layered composite membrane capable of inhibiting infection and promoting blood coagulation during wound healing.

Uncontrolled bleeding and bacterial infections cause severe damage to the wounds and remain a clinical challenge. Here, we developed a nanofiber/sponge bilayered composite membrane (QCP) containing quaternized silicone (QP12) and quaternized chitosan (QCS12) by joint approaches of electrospinning and freeze-drying and investigated their potential for wound dressing. The QCP was composed of a sponge (QCC) containing collagen (COL) and QCS12 and a nanofibrous membrane (MQP) containing poly-ε-caprolactone (PCL) and QP12. The QCP composite membrane possessed feasible permeability (0.22 ± 0.01 g/(cm2·24 h)), available thermal stability, suitable mechanical properties with natural skin, and in vivo hemostatic efficiency. The bonds of the N-quaternary and Schiff base endow composite membranes with significant anti-microbial invasion, potentially enhancing the wound healing process with an eligible microenvironment. Meanwhile, QCP evinced fine hemocompatibility, low cytotoxicity, negligible skin irritation, and other desirable biosafety as an excellent wound dressing. QCP promoted collagen deposition and re-epithelization to accelerate healing and suppress scars in the full-thickness acute wound models. Furthermore, the evaluation in the chronic skin incision model of diabetes mellitus manifested high healing efficiency with a certain resistance to bacterial infection of the composite membrane. Taken together, the QCP composite membrane may be a potential antibacterial and hemostatic wound dressing.

Time-dependent immune injury induced by short-term exposure to nanoplastics in the Sepia esculenta larvae.

Marine organisms are threatened by various environmental contaminants, and nanoplastics (NPs) is one of the most concerned. Studied have shown that NPs has a certain impact on marine organisms, but the specific molecular mechanism is still unclear. At present, researches on the effect of NPs on marine life mostly focus on crustaceans, gastropods, and bivalves. In this study, cephalopod Sepia esculenta larvae were first used to investigate the potential immune response molecular mechanisms caused by PS-NPs (50 nm, 50 mg/L) short-term exposure (4 and 24 h). Through S. esculenta larvae transcriptome profile of gene expression analysis, 548 and 1990 genes showed differential expression at 4 and 24 h after NPs exposure, respectively. GO and KEGG enrichment analysis were performed to find immune related DEGs. Then, the interaction relationship between the immune related DEGs after NPs exposure was known through the constructed protein-protein interaction network. 20 hub genes were found on the base of KEGG pathway numbers involved and protein-protein interaction numbers. This research supply valuable genes for the study of cephalopod immune response caused by NPs, which can help us further uncover the molecular mechanisms of organism against NPs.