Antimicrobial peptides for combating drug-resistant bacterial infections.

The problem of drug resistance due to long-term use of antibiotics has been a concern for years. As this problem grows worse, infections caused by multiple bacteria are expanding rapidly and are extremely detrimental to human health. Antimicrobial peptides (AMPs) are a good alternative to current antimicrobials with potent antimicrobial activity and unique antimicrobial mechanisms, which have advantages over traditional antibiotics in fighting against drug-resistant bacterial infections. Currently, researchers have conducted clinical investigations on AMPs for drug-resistant bacterial infections while integrating new technologies in the development of AMPs, such as changing amino acid structure of AMPs and using different delivery methods for AMPs. This article introduces the basic properties of AMPs, deliberates the mechanism of drug resistance in bacteria and the therapeutic mechanism of AMPs. The current disadvantages and advances of AMPs in combating drug-resistant bacterial infections are also discussed. This article provides important insights into the research and clinical application of new AMPs for drug-resistant bacterial infections.

Mesenchymal Stem Cell-Derived Exosomes as Drug Delivery Vehicles in Disease Therapy.

Exosomes are small vesicles containing proteins, nucleic acids, and biological lipids, which are responsible for intercellular communication. Studies have shown that exosomes can be utilized as effective drug delivery vehicles to accurately deliver therapeutic substances to target tissues, enhancing therapeutic effects and reducing side effects. Mesenchymal stem cells (MSCs) are a class of stem cells widely used for tissue engineering, regenerative medicine, and immunotherapy. Exosomes derived from MSCs have special immunomodulatory functions, low immunogenicity, the ability to penetrate tumor tissues, and high yield, which are expected to be engineered into efficient drug delivery systems. Despite the promising promise of MSC-derived exosomes, exploring their optimal preparation methods, drug-loading modalities, and therapeutic potential remains challenging. Therefore, this article reviews the related characteristics, preparation methods, application, and potential risks of MSC-derived exosomes as drug delivery systems in order to find potential therapeutic breakthroughs.

Atropselective synthesis of N-aryl pyridones via dynamic kinetic resolution enabled by non-covalent interactions.

The dynamic kinetic resolution of C-N atropisomeric pyridones was achieved via asymmetric phase-transfer catalysis, exploiting a rotational barrier-lowering hydrogen bond in the starting materials. X-ray and NMR experiments revealed the presence of a barrier-raising ground state CH⋯π interaction in the product, supported by DFT calculations. A co-crystal of the quinidine-derived phase-transfer catalyst and substrate reveals key substrate-catalyst non-covalent interactions.

Enhanced Hydrolytic Resistance of Fluorinated Silicon-Containing Polyether Urethanes.

The hydrolysis of a newly synthesized polyether urethane (PEU) that uses polydimethylsiloxane (PDMS) as a second macrodiol and fluorinated diol (FDO) as another chain extender has been studied via immersion in buffer solutions at 70 °C. The hydrolysis process was monitored using scanning electron microscopy (SEM), gel permeation chromatography (GPC), and tensile testing. After aging for 32 weeks, no surface defect was observed on the fluorinated silicon-containing PEUs (FSPEU). Meanwhile, the addition of FDO did not alter the other issues of bulk hydrolysis, such as the changes in molecular weight and mechanical strength. Moreover, microphase separation of FSPEU was suppressed during temperature-accelerated hydrolysis, whereas aging induced a more noticeable phase of morphological change in silicon-modified PEUs (SPEU) due to the hindrance effect of the fluorinated side chains. The formation of hydrolysis-prone allophanate is also reduced in the presence of FDO. FSPEU with enhanced antihydrolysis performance can potentially be applied to biostable medical devices.

Cytotoxic oligophenols from the rhizome of Wikstroemia indica.

A new tricoumarin glycoside, triumbelletin-7-O-ß-d-glucoside (1) and a new biflavonoid, wikstroflavone A (2), together with two known compounds, wikstaiwanone A (3) and wikstaiwanone B (4), were isolated from the rhizome of Wikstroemia indica. The structures of new compounds were elucidated by extensive spectroscopic techniques (UV, IR, HRESIMS, 1D, 2D NMR and CD), in combination with quantum chemical calculations of 13C NMR and ECD spectra. All isolates were tested for their antineoplastic activities against cancer-derived cell lines HCT116, SW480, U87 and T98G. Compounds 2-4 exhibited moderate cytotoxic activities to the four cell lines. The flow cytometry assay and western blot analysis revealed that the cytotoxic effects were possibly attributed to the induced apoptotic cell death.

Rigid External Distractor Aided Conventional Le Fort III Osteotomy Advancement in Adult With Severe Midfacial Hypoplasia.

BACKGROUND: Management of severe midfacial hypoplasia is still a challenge for craniofacial team, adult patients with syndromic midfacial hypoplasia made the situation even worse. The authors present the clinical result in an adult patient with Crouzon syndrome treated by rigid external distractor aided conventional Le Fort III procedure. METHODS: A 26-year-old patient with Crouzon syndrome presented with severe midfacial hypoplasia, a negative overjet of -17 mm, exorbitism, airway obstruction, and masticatory problem, while chief complaint of the patient was abnormal appearance. After Le Fort III osteotomy, rigid external distractor and distraction hooks were fixed. With the aid of rigid external distractor, the midfacial mass was immediately advanced to a desired position, allograft bone grafted in the gaps, and microplate fixed. The device was removed 3 weeks later when the advanced midface was stable. RESULTS: Point A was advanced by 18.6 mm in horizontal and displaced superiorly 0.5 mm in vertical at the time of device removal. Point A moved backward 1.5 mm and upward 0.3 mm at 2-year follow-up. A good and balanced facial profile was obtained in a short treatment period. Airway obstruction symptoms and exorbitism were relieved. CONCLUSIONS: The midfacial advancement achieved by rigid external distractor aided conventional Le Fort III osteotomy is a stable, controllable, and timesaving procedure. This technique may become an important choice for adult patients with severe midfacial hypoplasia.

Three-Dimensional Printing of Reduction Template in the Contouring of Craniofacial Fibrous Dysplasia.

BACKGROUND: Contouring is a minimal invasive procedure to remove excess lesions and restore facial appearance of patients with craniofacial fibrous dysplasia; however, it is difficult to measure the amount of excess lesions. This study is to demonstrate the use of reduction template produced by three-dimensional printer in contouring procedure. METHODS: Computed tomography data were reconstructed into a three-dimensional model by Mimics software. The unaffected side was mirrored and superimposed on the affected side. Excess fibrous dysplasia lesions were calculated by Boolean operations. Lesions to be removed were separated and saved as stereolithography file. This model was further constructed in 3-matic package of Mimics software, and several holes were designed to indicate the variation in depth. Finally, the virtual model was exported into three-dimensional printer to produce physical template. RESULTS: With the direct guidance of three-dimensional reduction template, contouring procedure was performed easily and accurately. Good facial symmetry was achieved with reduced operative time and loss of bleeding. CONCLUSIONS: The application of reduction template produced by three-dimensional printer in contouring procedure improves the efficient and safety of surgery. Good outcomes are obtained without extra requirement in craniofacial surgery.

An open auscultation dataset for machine learning-based respiratory diagnosis studies.

Machine learning enabled auscultating diagnosis can provide promising solutions especially for prescreening purposes. The bottleneck for its potential success is that high-quality datasets for training are still scarce. An open auscultation dataset that consists of samples and annotations from patients and healthy individuals is established in this work for the respiratory diagnosis studies with machine learning, which is of both scientific importance and practical potential. A machine learning approach is examined to showcase the use of this new dataset for lung sound classifications with different diseases. The open dataset is available to the public online.

Enhancing Mechanical Performance of High-Lignin-Filled Polypropylene via Reactive Extrusion.

Polypropylene (PP) is one of the most extensively used commodity plastics. In terms of eco-friendliness, it is worth considering preparing high-lignin-filled PP. This study explores the incorporation of high lignin content, derived from acetic acid lignin (AAL) and Kraft lignin (KL), into PP through twin-screw extrusion and injection molding. The challenge lies in maintaining mechanical performance. A compatibilizer-specifically, maleic anhydride-grafted polypropylene (MAPP)-is employed to enhance lignin-PP compatibility by chemically bonding with lignin and physically associating with the PP phase. Results indicate that KL maintains better dispersity than AAL. Compatibilizers with a high maleic anhydride (MA) level (≥0.8 wt.%) and moderate melt flow index (MFI) in the range of 60-100 g 10 min⁻¹ prove favorable in constructing a reinforced PP/KL network. Optimizing with 40 wt.% lignin content and 10 parts per hundred (pph) of compatibilizer yields blends with mechanical performance comparable to neat PP, exhibiting a notable increase in modulus and heat deflection temperature (HDT). Furthermore, utilizing PP/lignin blends can lead to a 20% reduction in expenses and approximately 40% reduction in PP-induced greenhouse gas (GHG) emissions. This approach not only reduces PP costs but also adds value to lignin utilization in a sustainable and cost-effective manner.

Interfacial energy conversion mechanism between 3003 aluminum alloy and 321 stainless steel in vaporizing foil actuator welding process.

Conventional welding methods encounter significant challenges, including poor weldability, low joint strength, and the formation of brittle intermetallic compounds, primarily due to the substantial disparities in the physical and chemical properties of aluminum and iron. To mitigate these issues, the vaporizing foil actuator welding (VFAW) process has emerged as a highly promising solid-phase welding technology, particularly suitable for joining dissimilar metals with pronounced differences in properties, such as aluminum alloys and stainless steels. The present study provides an innovative quantitative analysis of the interfacial impact energy conversion mechanisms within the VFAW process. The analysis reveals that the energy responsible for accelerating the flyer workpiece comprises burst vaporization energy ( E d ) and continuous vaporization energy ( E p ), with E d identified as the primary energy source, contributing approximately 65-80% of the total energy required for acceleration. Further examination elucidates the mechanisms underlying heat generation and transfer during the interface collision. The investigation identifies the formation of an overheating zone at the interface, attributed to the combined effects of plastic deformation energy and adiabatic shear energy within the flyer workpiece. Consequently, the interface temperature can rise significantly, reaching up to 1394 K, with impact velocities as high as 925 m/s. The analyses contribute to establishing a theoretical foundation for understanding the interface bonding mechanisms characteristic of the vaporizing foil actuator welding method.

Effects of percutaneous closure of atrial septal defects via the right internal jugular vein.

Background: Percutaneous atrial septal defect (ASD) closure is the preferred treatment for patients with suitable ASD anatomy. The safety and effectiveness of transcatheter closure have been established. However, reports on transesophageal echocardiography (TEE)-guided percutaneous closure of ASD via the right internal jugular vein (RIJV) are limited. The study aims to discuss the safety and effectiveness of percutaneous trans-jugular vein closure of ASD. Methods: We conducted a retrospective analysis of patients (n=103) with secondary ASD who underwent surgical treatment in the Department of Cardiovascular Surgery, the Second Hospital of Jilin University between July 2015 to July 2022. The article is a cross-sectional study. Clinical data, including age, gender, weight, defect diameter, tricuspid regurgitation, left atrial (LA) size, and the operation results, were collected and evaluated. Nonparametric rank sum tests were used to assess tricuspid regurgitation before and after surgery, while paired sample t-tests were used to compare LA size before and after surgery. Results: TEE-guided percutaneous closure of ASD via the RIJV was successfully performed in 97 out of 103 (94.2%) cases. The average procedure time was 34.48±13.06 min, and the mean age at the time of the procedure and ASD size were 36±18 years and 15.45±5.82 mm, respectively. On analyzing medical records and echocardiographic images, postoperative complications were found to occur in four (3.9%) patients. Among these, three patients had residual shunt as indicated by echocardiography during the operation, which subsequently disappeared at the three-month follow-up. One patient developed atrial fibrillation after surgery but returned to normal sinus rhythm with medication. Percutaneous closure of ASD via the RIJV was unsuccessful in 6 patients (5.8%), with 5 of them undergoing transthoracic ASD closure and achieving satisfactory results. One patient refused further surgical treatment. No pericardial effusion, thrombosis, atrioventricular block, or other complications were observed during the 3-month to 1-year follow-up period. Conclusions: ASD closure via the RIJV is a safe and effective therapeutic approach. The initial results are satisfactory, but further studies with large sample sizes and long-term follow-up are warranted to assess the long-term outcomes.

Truncated VZV gE Induces High-Titer Neutralizing Antibodies in Mice.

Backgrounds: A contemporary public health challenge is the increase in the prevalence rates of herpes zoster (HZ) worldwide. Methods: In this work, the gE gene structure was analyzed using bioinformatics techniques, and three plasmids of varying lengths, tgE537, tgE200, and tgE350, were expressed in Chinese hamster ovary (CHO) cells. These proteins were used to immunize BALB/c mice with Al/CpG adjuvant; ELISPOT and FCM were used to evaluate cellular immunity; and ELISA, VZV microneutralization, and FAMA assays were performed to detect antibody titers. Results: Target protein concentrations of 1.8 mg/mL for tgE537, 0.15 mg/mL for tgE200 and 0.65 mg/mL for tgE350 were effectively produced. The ability of the three protein segments to stimulate CD4+ and CD8+ T cells, as well as to cause lymphocytes to secrete IFN-γ and IL-4, did not significantly differ from one another. Both tgE537 and tgE350 were capable of generating VZV-specific antibodies and neutralizing antibodies, while tgE350 had the highest neutralizing antibody titer (4388). There was no equivalent humoral immune response induced by tgE200. Conclusions: The results of this investigation provide the groundwork for the creation of HZ recombinant vaccines using truncated proteins as antigens.

Genetic Characteristics of Wuxiang Virus in Shanxi Province, China.

Wuxiang virus (WUXV) is the first sandfly-borne Phlebovirus isolated from Phlebotomus chinensis collected in China and has been established as a consistent viral presence in the local sandfly populations of both Wuxiang County and Yangquan City. However, its distribution in the Shanxi Province remains unclear. In this study, three novel WUXV strains were isolated from sandflies collected from Jiexiu City, Shanxi Province, China, in 2022. Subsequently, whole-genome sequences of these novel strains were generated using next-generation sequencing. The open reading frame (ORF) sequences of the WUXV strains from the three locations were subjected to gene analysis. Phylogenetic analysis revealed that WUXV belongs to two distinct clades with geographical differences. Strains from Wuxiang County and Yangquan City belonged to clade 1, whereas strains from Jiexiu City belonged to clade 2. Reassortment and recombination analyses indicated no gene reassortment or recombination between the two clades. However, four reassortments or recombination events could be detected in clade 1 strains. By aligning the amino acid sequences, eighty-seven mutation sites were identified between the two clades, with seventeen, sixty, nine, and one site(s) in the proteins RdRp, M, NSs, and N, respectively. Additionally, selection pressure analysis identified 17 positively selected sites across the entire genome of WUXV, with two, thirteen, one, and one site(s) in the proteins RdRp, M, NSs, and N, respectively. Notably, sites M-312 and M-340 in the M segment not only represented mutation sites but also showed positive selective pressure effects. These findings highlight the need for continuous nationwide surveillance of WUXV.

Fabrication of Graphitized Carbon Fibers from Fusible Lignin and Their Application in Supercapacitors.

Lignin-based carbon fibers (LCFs) with graphitized structures decorated on their surfaces were successfully prepared using the simultaneous catalyst loading and chemical stabilization of melt-spun lignin fibers, followed by quick carbonization functionalized as catalytic graphitization. This technique not only enables surficial graphitized LCF preparation at a relatively low temperature of 1200 °C but also avoids additional treatments used in conventional carbon fiber production. The LCFs were then used as electrode materials in a supercapacitor assembly. Electrochemical measurements confirmed that LCF-0.4, a sample with a relatively low specific surface area of 89.9 m2 g-1, exhibited the best electrochemical properties. The supercapacitor with LCF-0.4 had a specific capacitance of 10.7 F g-1 at 0.5 A g-1, a power density of 869.5 W kg-1, an energy density of 15.7 Wh kg-1, and a capacitance retention of 100% after 1500 cycles, even without activation.

Pt single atoms and defect engineering of TiO2-nanosheet-assembled hierarchical spheres for efficient room-temperature HCHO oxidation.

Achieving high atomic utilization and low cost of desirable Pt/TiO2 catalysts is a major challenge for room temperature HCHO oxidation. Here, the strategy of anchoring stable Pt single atoms by abundant oxygen vacancies over TiO2-nanosheet-assembled hierarchical spheres (Pt1/TiO2-HS) was designed to eliminate HCHO. A superior HCHO oxidation activity and CO2 yield (∼100% CO2 yield) at relative humidity (RH) > 50% over Pt1/TiO2-HS is achieved for long-term run. We attribute the excellent HCHO oxidation performance to the stable isolated Pt single atoms anchored on the defective TiO2-HS surface. The Ptδ+ on the Pt1/TiO2-HS surface has a facile intense electron transfer with the support by forming Pt-O-Ti linkages, driving HCHO oxidation effectively. Further in situ HCHO-DRIFTS revealed that the dioxymethylene (DOM) and HCOOH/HCOO- intermediates were further degraded via active OH- and adsorbed oxygen on the Pt1/TiO2-HS surface, respectively. This work may pave the way for the next generation of advanced catalytic materials for high-efficiency catalytic HCHO oxidation at room temperature.

Base composition, adaptation, and evolution of goose astroviruses: codon-based investigation.

Goose astroviruses (GoAstVs) are causative agents that account for fatal infection of goslings characterized by visceral urate deposition, resulting in severe economic losses in major goose-producing regions in China since 2017. In this study, we sought to unravel the intrinsic properties associated with adaptation and evolution in the host environment of GoAstVs. Consistent results from phylogenetic analysis and correspondence analysis performed on the codon usage patterns (CUPs) reveal 2 clusters of GoAstVs, namely, GoAstV-1 and GoAstV-2. However, multiple similar compositional characteristics were found, despite the high divergence between GoAstV-1 and GoAstV-2. Studies on the base composition of GoAstVs reveal an A/U bias, indicating a compositional constraint, while natural selection prevailed in determining the CUPs in the virus genome based on our neutrality plot analysis, reflecting high adaptive pressure to fit the host environment. Codon adaptation index (CAI) analysis revealed a higher degree of fitness to the CUPs of the corresponding host for GoAstVs than avian influenza virus and betacoronaviruses, which may be a favorable factor contributing to the high pathogenicity and wide distribution of GoAstVs in goslings. In addition, GoAstVs were less adapted to ducks and chickens, with significantly lower CAI values than to geese, which may be a reason for the different prevalence of GoAstVs among these species. Extensive investigations on dinucleotide distribution revealed a significant suppression of the CpG and UpA motifs in the virus genome, which may facilitate adaptation to the host's innate immune system by evading surveillance. In addition, our study reported the trends of increasing fitness to the host's microenvironment for GoAstVs through increasing adaptation to host CUPs and ongoing reduction of CpG motifs in the virus genome. The present analysis deepens our understanding of the basic biology, pathogenesis, adaptation and evolutionary pattern of GoAstVs, and contributes to the development of novel antiviral strategies.

Persistence of Tembusu Virus in Culex tritaeniorhynchus in Yunnan Province, China.

The Tembusu virus (TMUV), a member of the Flaviviridae family, can be transmitted via mosquitoes and cause poultry disease. In 2020, a strain of TMUV (YN2020-20) was isolated from mosquito samples collected in Yunnan province, China. In vitro experiments showed that TMUV-YN2020-20 produced a significant cytopathic effect (CPE) in BHK, DF-1, and VERO cells, while the CPE in C6/36 cells was not significant. Phylogenetic analysis revealed that the strain belonged to Cluster 3.2 and was closely related to the Yunnan mosquito-derived isolates obtained in 2012 and the Shandong avian-derived isolate obtained in 2014. Notably, TMUV-YN2020-20 developed five novel mutations (E-V358I, NS1-Y/F/I113L, NS4A-T/A89V, NS4B-D/E/N/C22S, and NS5-E638G) at loci that were relatively conserved previously. The results of this study demonstrate the continuous circulation and unique evolution of TMUV in mosquitoes in Yunnan province and suggest that appropriate surveillance should be taken.

Metatranscriptomics Reveals the RNA Virome of Ixodes Persulcatus in the China-North Korea Border, 2017.

In recent years, numerous viruses have been identified from ticks, and some have been linked to clinical cases of emerging tick-borne diseases. Chinese northeast frontier is tick infested. However, there is a notable lack of systematic monitoring efforts to assess the viral composition in the area, leaving the ecological landscape of viruses carried by ticks not clear enough. Between April and June 2017, 7101 ticks were collected to perform virus surveillance on the China-North Korea border, specifically in Tonghua, Baishan, and Yanbian. A total of 2127 Ixodes persulcatus were identified. Further investigation revealed the diversity of tick-borne viruses by transcriptome sequencing of Ixodes persulcatus. All ticks tested negative for tick-borne encephalitis virus. Transcriptome sequencing expanded 121 genomic sequence data of 12 different virus species from Ixodes persulcatus. Notably, a new segmented flavivirus, named Baishan Forest Tick Virus, were identified, closely related to Alongshan virus and Harz mountain virus. Therefore, this new virus may pose a potential threat to humans. Furthermore, the study revealed the existence of seven emerging tick-borne viruses dating back to 2017. These previously identified viruses included Mudanjiang phlebovirus, Onega tick phlebovirus, Sara tick phlebovirus, Yichun mivirus, and three unnamed viruses (one belonging to the Peribunyaviridae family and the other two belonging to the Phenuiviridae family). The existence of these emerging tick-borne viruses in tick samples collected in 2017 suggests that their history may extend further than previously recognized. This study provides invaluable insights into the virome of Ixodes persulcatus in the China-North Korea border region, enhancing our ongoing efforts to manage the risks associated with tick-borne viruses.

Human and animal exposure to newly discovered sand fly viruses, China.

Introduction: The Hedi virus (HEDV) and Wuxiang virus (WUXV) are newly discovered Bunyaviruses transmitted by sandflies. The geographical distribution of isolation of these two viruses continues to expand and it has been reported that WUXV causes neurological symptoms and even death in suckling mice. However, little is known about the prevalence of the two viruses in mammalian infections. Methods: In order to understand the infection status of HEDV and WUXV in humans and animals from regions where the viruses have been isolated, this study used Western blotting to detect the positive rates of HEDV and WUXV IgG antibodies in serum samples from febrile patients, dogs, and chickens in the forementioned regions. Results: The results showed that of the 29 human serum samples, 17.24% (5/29) tested positive for HEDV, while 68.96% (20/29) were positive for WUXV. In the 31 dog serum samples, 87.10% (27/31) were positive for HEDV and 70.97% (22/31) were positive for WUXV, while in the 36 chicken serum samples, 47.22% (17/36) were positive for HEDV, and 52.78% (19/36) were positive for WUXV. Discussion: These findings suggest there are widespread infections of HEDV and WUXV in mammals (dogs, chickens) and humans from the regions where these viruses have been isolated. Moreover, the positive rate of HEDV infections was higher in local animals compared to that measured in human specimens. This is the first seroepidemiological study of these two sandfly-transmitted viruses. The findings of the study have practical implications for vector-borne viral infections and related zoonotic infections in China, as well as providing an important reference for studies on the relationship between sandfly-transmitted viruses and zoonotic infections outside of China.

Synergistically Promoting Coking Resistance of a La0.4Sr0.4Ti0.85Ni0.15O3-δ Anode by Ru-Doping-Induced Active Twin Defects and Highly Dispersed Ni Nanoparticles.

The development of anodes with highly efficient electrochemical catalysis and good durability is crucial for solid oxide fuel cells (SOFCs). This paper reports a superior Ru-doped La0.4Sr0.4Ti0.85Ni0.15O3-δ (L0.4STN) anode material with excellent catalytic activity and good stability. The doping of Ru can inhibit the agglomeration of in situ-exsolved Ni nanoparticles on the surface and induce the formation of abundant multiple-twinned defects in the perovskite matrix, which significantly increase the concentration of oxygen vacancies. The reduced L0.4STRN (R-L0.4STRN) anode shows an area-specific resistance (ASR) of 0.067 Ω cm2 at 800 °C, which is only about one-third of that of stochiometric R-L0.6STN (0.212 Ω cm2). A single cell with the R-L0.4STRN anode shows excellent stability (∼50 h at 650 °C) in both H2 and CH4. Furthermore, R-L0.4STRN exhibits outstanding resistance to carbon deposition, which can be attributed to the synergistic effect of highly dispersed Ni nanoparticles and active twinned defects induced by Ru doping.