Synthesis, Characterization and Antibacterial Activity Study of Para-substituted Derivatives of N -benzyl-3-methylbuten-2-enamides.

In order to deeply explore the effect of para-substituents on the antibacterial activity of N-benzyl-3-methylbuten-2- enamide derivatives, we elaborately synthesized three such para-substituted derivatives (compound a: N-(4-hydroxybenzyl)-3-methylbut 2- enamide; compound b: N-(4-isobutoxybenzyl)-3- methylbut-2-enamide; compound c: N-(4-isopropoxybenzyl) -3-methylbut-2- enamide), of which the structures were determined by ways of single crystal X-ray diffraction data analysis mainly. The antibacterial performance experiments showed that compounds a, b and c were evaluated for their antibacterial (Escherichia coli, Staphylococcus aureus, and Enterobacter aerogenes) activities. Among them, compounds a, b and c have an effective antibacterial reagents for E. coli exhibiting MIC values of 0.01, 0.01 and 0.01 g/mL, respectively, but inactive for E. aerogenes. In addition, compounds b and c have better activity than compound a against S. aureus with MIC values of 0.01 and 0.02 g/mL. These results provide an important basis for further study of the antibacterial properties and structure-activity relationship of these compounds, and are expected to provide valuable reference for the development of new antibacterial drugs.

The roles of cell wall inhibition responsive protein CwrA in the pathogenicity of Staphylococcus aureus.

The ability to form robust biofilms and secrete a diverse array of virulence factors are key pathogenic determinants of Staphylococcus aureus, causing a wide range of infectious diseases. Here, we characterized cwrA as a VraR-regulated gene encoding a cell wall inhibition-responsive protein (CwrA) using electrophoretic mobility shift assays. We constructed cwrA deletion mutants in the genetic background of methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) strains. Phenotypic analyses indicated that deletion of cwrA led to impaired biofilm formation, which was correlated with polysaccharide intercellular adhesin (PIA). Besides, the results of real-time quantitative PCR (RT-qPCR) and ß-galactosidase activity assay revealed that CwrA promoted biofilm formation by influence the ica operon activity in S. aureus. Furthermore, cwrA deletion mutants released less extracellular DNA (eDNA) in the biofilm because of their reduced autolytic activity compared to the wild-type (WT) strains. We also found that cwrA deletion mutant more virulence than the parental strain because of its enhanced hemolytic activity. Mechanistically, this phenotypic alteration is related to activation of the SaeRS two-component system, which positively regulates the transcriptional levels of genes encoding membrane-damaging toxins. Overall, our results suggest that CwrA plays an important role in modulating biofilm formation and hemolytic activity in S. aureus.

HOLI-1-to-3: Transient-Enhanced Holistic Image-to-3D Generation.

We introduce HOLI-1-to-3, a novel technique for holistic 3D shape recovery from a single-viewpoint input, by effectively combining line-of-sight (LOS) and non-line-of-sight (NLOS) imaging. We leverage advancements in ultrafast time-of-flight (ToF) sensors and learning-based 3D shape inference techniques, such as diffusion models. HOLI-1-to-3 employs a new neural plenoptic representation, which unifies radiance fields (for LOS RGB images) and transient fields (for NLOS transients). HOLI-1-to-3 is optimized through a two-stage pipeline involving diffusion priors and transients prior. Our technique allows for accurate and continuous reconstruction of both visible and invisible parts of objects from a single view. Comprehensive experiments on both simulated and real-world datasets demonstrate the effectiveness of HOLI-1-to-3 in resolving ambiguities in invisible parts of objects and significantly improving overall generation quality. The datasets used in our experiments will be made available to the research community to facilitate further achievements in holistic 3D shape recovery.

Insights into small-molecule compound CY-158-11 antibacterial activity against Staphylococcus aureus.

The widespread prevalence and dissemination of antibiotic-resistant bacteria, coupled with the diminishing supply of new antibiotics, emphasize the pressing necessity for the exploration of innovative antibacterial agents. Previously, we detailed the impact of the small-molecule compound CY-158-11 on S. aureus biofilm. By hindering adhesion and PIA-mediated biofilm formation, subinhibitory concentrations of CY-158-11 exhibit antibiofilm activity toward S. aureus. Here, we sought to elucidate the antibacterial activity and mode of action of this compound. Upon CY-158-11 treatment in culture, the inhibition of bacterial growth, coupled with MBC to MIC of >4, indicated that CY-158-11 exerted a bacteriostatic effect. Particularly, CY-158-11 showed strong antibacterial activity against a wide variety of S. aureus, including multidrug-resistant bacteria. We found that CY-158-11 promoted the permeability of cell membrane and propidium iodide absorption as well as caused the dissipation of membrane potential. The effect of CY-158-11 on the mammalian cytoplasmic membrane was measured using hemolytic and cytotoxicity assays, and the skin irritation and systemic toxicity of the drug were measured by injecting the compound into the skin and tail vein of mice. Moreover, CY-158-11 exhibited considerable efficacy in a subcutaneous abscess mouse model of S. aureus infection. In conclusion, CY-158-11 possesses antibacterial properties, including inhibition of bacterial growth, damage to cell membranes, and treatment of skin abscesses, which can be a promising therapeutic option for combating S. aureus. IMPORTANCE: The combination of the rising incidence of antibiotic resistance and the shrinking antibiotic pipeline has raised concern about the postantibiotic era. New antibacterial agents and targets are required to combat S. aureus-associated infections. In this study, we identified a maleimide-diselenide hybrid compound CY-158-11 exhibiting antibacterial activity against S. aureus in vitro and in vivo at relatively low concentrations. Furthermore, the investigation of its mode of action revealed that CY-158-11 can selectively perturb the cytoplasmic membrane of bacteria without harming mammalian cells or mouse organs. Thus, CY-158-11 is a compelling novel drug for development as a new therapy for S. aureus infections.

Precision encoder grating mounting: a near-sensor computing approach.

The rotary motor plays a pivotal role in various motion execution mechanisms. However, an inherent issue arises during the initial installation of the encoder grating, namely, eccentricity between the centers of the encoder grating and motor shaft. This eccentricity substantially affects the accuracy of motor angle measurements. To address this challenge, we proposed a precision encoder grating mounting system that automates the encoder grating mounting process. The proposed system mainly comprises a near-sensor detector and a push rod. With the use of a near-sensor approach, the detector captures rotating encoder grating images, and the eccentricity is computed in real-time. This approach substantially reduces the time delays in image data transmission, thereby enhancing the speed and accuracy of eccentricity calculation. The major contribution of this article is a method for real-time eccentricity calculation that leverages an edge processor within the detector and an edge-vision baseline detection algorithm. This method enables real-time determination of the eccentricity and eccentricity angle of the encoder grating. Leveraging the obtained eccentricity and eccentricity angle data, the position of the encoder grating can be automatically adjusted by the push rod. In the experimental results, the detector can obtain the eccentricity and eccentricity angle of the encoder grating within 2.8 s. The system efficiently and precisely completes a encoder grating mounting task in average 25.1 s, and the average eccentricity after encoder grating mounting is 3.8 µm.

Biofilm-producing ability of methicillin-resistant Staphylococcus aureus clinically isolated in China.

BACKGROUND: Staphylococcus aureus, a commensal bacterium, colonizes the skin and mucous membranes of approximately 30% of the human population. Apart from conventional resistance mechanisms, one of the pathogenic features of S. aureus is its ability to survive in a biofilm state on both biotic and abiotic surfaces. Due to this characteristic, S. aureus is a major cause of human infections, with Methicillin-Resistant Staphylococcus aureus (MRSA) being a significant contributor to both community-acquired and hospital-acquired infections. RESULTS: Analyzing non-repetitive clinical isolates of MRSA collected from seven provinces and cities in China between 2014 and 2020, it was observed that 53.2% of the MRSA isolates exhibited varying degrees of ability to produce biofilm. The biofilm positivity rate was notably high in MRSA isolates from Guangdong, Jiangxi, and Hubei. The predominant MRSA strains collected in this study were of sequence types ST59, ST5, and ST239, with the biofilm-producing capability mainly distributed among moderate and weak biofilm producers within these ST types. Notably, certain sequence types, such as ST88, exhibited a high prevalence of strong biofilm-producing strains. The study found that SCCmec IV was the predominant type among biofilm-positive MRSA, followed by SCCmec II. Comparing strains with weak and strong biofilm production capabilities, the positive rates of the sdrD and sdrE were higher in strong biofilm producers. The genetic determinants ebp, icaA, icaB, icaC, icaD, icaR, and sdrE were associated with strong biofilm production in MRSA. Additionally, biofilm-negative MRSA isolates showed higher sensitivity rates to cefalotin (94.8%), daptomycin (94.5%), mupirocin (86.5%), teicoplanin (94.5%), fusidic acid (81.0%), and dalbavancin (94.5%) compared to biofilm-positive MRSA isolates. The biofilm positivity rate was consistently above 50% in all collected specimen types. CONCLUSIONS: MRSA strains with biofilm production capability warrant increased vigilance.

Advances in co-pathogenesis of the united airway diseases.

According to the concept of "united airway diseases", the airway is a single organ in which upper and lower airway diseases are commonly comorbid. A range of inflammatory factors have been found to play an important role in the chain reaction of upper and lower airway diseases. However, the amount of research on this concept remains limited. The underlying mechanism of the relationship between typical diseases of the united airway, such as asthma, allergic rhinitis, and chronic sinusitis, also needs to be further explored. This review highlights the interaction between upper and lower respiratory diseases gathered from epidemiological, histoembryology, neural mechanistic, microbiological, and clinical studies, revealing the relationship between the upper and lower respiratory tracts.

Effects of HMGB1/TLR4 on secretion IL-10 and VEGF in human jaw bone-marrow mesenchymal stem cells.

OBJECTIVE: We aimed to investigate the regulatory effects of HMGB1/TLR4 signaling pathway on the expression of IL-10 and VEGF in human bone marrow mesenchymal stem cells. METHODOLOGY: Human JBMSCs were isolated and cultured. Then, HMGB1 was added into the JBMSCs culture medium, and the protein and mRNA expression levels of IL-10 and VEGF were assessed. Moreover, cells were pretreated with a specific TLR4 inhibitor (TAK-242), and the expression changes of IL-10 and VEGF were compared. RESULTS: Compared with the control group, exposure to HMGB1 in human JBMSCs up-regulated TLR4, IL-10, and VEGF secretion at both protein and mRNA levels (P<0. 05). In addition, the increased expression of IL-10 and VEGF could be restrained in TAK-242 group compared with the HMGB1 group (P<0.05). CONCLUSIONS: The results indicated that HMGB1 activate TLR4 signaling pathway in Human JBMSCs, which plays a regulatory role in cytokines expression.

Dynamic Structural Change of Plant Epidermal Cell Walls under Strain.

The molecular foundations of epidermal cell wall mechanics are critical for understanding structure-function relationships of primary cell walls in plants and facilitating the design of bioinspired materials. To uncover the molecular mechanisms regulating the high extensibility and strength of the cell wall, the onion epidermal wall is stretched uniaxially to various strains and cell wall structures from mesoscale to atomic scale are characterized. Upon longitudinal stretching to high strain, epidermal walls contract in the transverse direction, resulting in a reduced area. Atomic force microscopy shows that cellulose microfibrils exhibit orientation-dependent rearrangements at high strains: longitudinal microfibrils are straightened out and become highly ordered, while transverse microfibrils curve and kink. Small-angle X-ray scattering detects a 7.4 nm spacing aligned along the stretch direction at high strain, which is attributed to distances between individual cellulose microfibrils. Furthermore, wide-angle X-ray scattering reveals a widening of (004) lattice spacing and contraction of (200) lattice spacing in longitudinally aligned cellulose microfibrils at high strain, which implies longitudinal stretching of the cellulose crystal. These findings provide molecular insights into the ability of the wall to bear additional load after yielding: the aggregation of longitudinal microfibrils impedes sliding and enables further stretching of the cellulose to bear increased loads.

Single-pixel p-graded-n junction spectrometers.

Ultra-compact spectrometers are becoming increasingly popular for their promising applications in biomedical analysis, environmental monitoring, and food safety. In this work, we report a single-pixel-photodetector spectrometer with a spectral range from 480 nm to 820 nm, based on the AlGaAs/GaAs p-graded-n junction with a voltage-tunable optical response. To reconstruct the optical spectrum, we propose a tailored method called Neural Spectral Fields (NSF) that leverages the unique wavelength and bias-dependent responsivity matrix. Our spectrometer achieves a high spectral wavelength accuracy of up to 0.30 nm and a spectral resolution of up to 10 nm. Additionally, we demonstrate the high spectral imaging performance of the device. The compatibility of our demonstration with the standard III-V process greatly accelerates the commercialization of miniaturized spectrometers.

Optical ReLU-like activation function based on a semiconductor laser with optical injection.

Artificial neural networks usually consist of successive linear multiply-accumulate operations and nonlinear activation functions. However, most optical neural networks only achieve the linear operation in the optical domain, while the optical implementation of activation function remains challenging. Here we present an optical ReLU-like activation function (with 180° rotation) based on a semiconductor laser subject to the optical injection in an experiment. The ReLU-like function is achieved in a broad regime above the Hopf bifurcation of the injection-locking diagram and is operated in the continuous-wave mode. In particular, the slope of the activation function is reconfigurable by tuning the frequency difference between the master laser and the slave laser.

Two Undescribed Protostane Triterpenoids from the Rhizome of Alisma plantago-aquatica.

Two undescribed protostane triterpenoids, 11-deoxy-13(17),15-dehydro-alisol B 23-acetate (2) and alisol S (3), together with 21 known ones (1, 4-23), were isolated from the dried rhizome of Alisma plantago-aquatica. Of these compounds, 13(17),15-Dehydro-alisol B 23-acetate (1) and 11-deoxy-13(17),15-dehydro-alisol B 23-acetate (2) are two protostane triterpenoids containing conjugated double bonds in the five-membered ring D that are rarely found from nature resource, while alisol S (3) is a protostane triterpenoid with undescribed tetrahydrofuran moiety linked via C20 -O-C24 at the side chain. Additionally, compound 18 is a new natural product, and cycloartenol triterpenoid 23 is a non protostane triterpenoid firstly isolated from genus Alisma. Their structures were elucidated by extensive spectral analysis of the UV, IR, MS, 1D and 2D NMR, and comparison of the experimental and calculated CD curves.

Emergence of KPC-2 and NDM-5-coproducing hypervirulent carbapenem-resistant Klebsiella pneumoniae with high-risk sequence types ST11 and ST15.

The emergence of Klebsiella pneumoniae carbapenemase-2 (KPC-2) and New Delhi metallo-ß-lactamase (NDM)-coproducing hypervirulent carbapenem-resistant Klebsiella pneumoniae (KPC-2-NDM-hv-CRKP) poses a certain threat to public health. Currently, only a few sporadic reports of such double-positive hv-CRKPs were available. In this study, we isolated two KPC-2-NDM-5-hv-CRKPs from elderly patients with serious underlying diseases and poor prognoses. We found both FK3122 and FK3127 were typical multidrug-resistant (MDR) isolates, exhibiting high-level resistance to both carbapenems and novel ß-lactamase inhibitors ceftazidime/avibactam. Notably, FK3122 is even resistant to cefiderocol due to multiple blaNDM-5 elements. Besides the MDR phenotype, A549 human lung epithelial cells and Galleria mellonella infection model all indicated that FK3122 and FK3127 were highly pathogenic. According to the whole-genome sequencing analysis, we observed over 10 resistant elements, and the uncommon co-existence of blaKPC-2, blaNDM-5, and virulence plasmids in both two isolates. Both virulence plasmids identified in FK3122 and FK3127 shared a high identity with classical virulence plasmid pK2044, harboring specific hypervirulent factors: rmpA and iuc operon. We also found that the resistance and virulence plasmids in FK3127 could not only be transferred to Escherichia coli EC600 independently but also together as a co-transfer, which was additionally confirmed by the S1-pulsed-field gel electrophoresis plasmid profile. Moreover, polymorphic mobile genetic elements were found surrounding resistance genes, which may stimulate the mobilization of resistance genes and result in the duplication of these elements. Considering the combination of high pathogenicity, limited therapy options, and easy transmission of KPC-2-NDM-5-hv-CRKP, our study emphasizes the need for underscores the imperative for ongoing surveillance of these pathogens.IMPORTANCEHypervirulent Klebsiella pneumoniae drug resistance has increased gradually with the emergence of carbapenem-resistant hypervirulent K. pneumoniae (hv-CRKP). However, little information is available on the virulence characteristics of the New Delhi metallo-ß-lactamase (NDM) and Klebsiella pneumoniae carbapenemase-2 (KPC-2) co-producing K. pneumoniae strains. In this study, we obtained two KPC-2-NDM-hv-CRKPs from elderly patients, each with distinct capsule types and sequence types: ST11-KL64 and ST15-KL24; these ST-type lineages are recognized as classical multidrug-resistant (MDR) K. pneumoniae. We found these KPC-2-NDM-hv-CRKPs were not only typical MDR isolates, including resistance to ceftazidime/avibactam and cefiderocol, but also displayed exceptionally high levels of pathogenicity. In addition, these high-risk factors can also be transferred to other isolates. Consequently, our study underscores the need for ongoing surveillance of these isolates due to their heightened pathogenicity, limited therapeutic options, and potential for easy transmission.

The nonlinear mechanics of highly extensible plant epidermal cell walls.

Plant epidermal cell walls maintain the mechanical integrity of plants and restrict organ growth. Mechanical analyses can give insights into wall structure and are inputs for mechanobiology models of plant growth. To better understand the intrinsic mechanics of epidermal cell walls and how they may accommodate large deformations during growth, we analyzed a geometrically simple material, onion epidermal strips consisting of only the outer (periclinal) cell wall, ~7 µm thick. With uniaxial stretching by >40%, the wall showed complex three-phase stress-strain responses while cyclic stretching revealed reversible and irreversible deformations and elastic hysteresis. Stretching at varying strain rates and temperatures indicated the wall behaved more like a network of flexible cellulose fibers capable of sliding than a viscoelastic composite with pectin viscosity. We developed an analytic framework to quantify nonlinear wall mechanics in terms of stiffness, deformation, and energy dissipation, finding that the wall stretches by combined elastic and plastic deformation without compromising its stiffness. We also analyzed mechanical changes in slightly dehydrated walls. Their extension became stiffer and more irreversible, highlighting the influence of water on cellulose stiffness and sliding. This study offers insights into the structure and deformation modes of primary cell walls and presents a framework that is also applicable to tissues and whole organs.

Effects of HMGB1/TLR4 on secretion IL-10 and VEGF in human jaw bone-marrow mesenchymal stem cells

Abstract Objective: We aimed to investigate the regulatory effects of HMGB1/TLR4 signaling pathway on the expression of IL-10 and VEGF in human bone marrow mesenchymal stem cells. Methodology: Human JBMSCs were isolated and cultured. Then, HMGB1 was added into the JBMSCs culture medium, and the protein and mRNA expression levels of IL-10 and VEGF were assessed. Moreover, cells were pretreated with a specific TLR4 inhibitor (TAK-242), and the expression changes of IL-10 and VEGF were compared. Results: Compared with the control group, exposure to HMGB1 in human JBMSCs up-regulated TLR4, IL-10, and VEGF secretion at both protein and mRNA levels (P<0. 05). In addition, the increased expression of IL-10 and VEGF could be restrained in TAK-242 group compared with the HMGB1 group (P<0.05). Conclusions: The results indicated that HMGB1 activate TLR4 signaling pathway in Human JBMSCs, which plays a regulatory role in cytokines expression.

Regiospecific Cellulose Orientation and Anisotropic Mechanical Property in Plant Cell Walls.

Cellulose microfibrils (CMFs) are a major load-bearing component in plant cell walls. Thus, their structures have been studied extensively with spectroscopic and microscopic characterization methods, but the findings from these two approaches were inconsistent, which hampers the mechanistic understanding of cell wall mechanics. Here, we report the regiospecific assembly of CMFs in the periclinal wall of plant epidermal cells. Using sum frequency generation spectroscopic imaging, we found that CMFs are highly aligned in the cell edge region where two cells form a junction, whereas they are mostly isotropic on average throughout the wall thickness in the flat face region of the epidermal cell. This subcellular-level heterogeneity in the CMF alignment provided a new perspective on tissue-level anisotropy in the tensile modulus of cell wall materials. This finding also has resolved a previous contradiction between the spectroscopic and microscopic imaging studies, which paves a foundation for better understanding of the cell wall architecture, especially structure-geometry relationships.

Total glucosides of Rhizoma Smilacis Glabrae: a therapeutic approach for psoriasis by regulating Th17/Treg balance.

Total glucosides of Rhizoma Smilacis Glabrae (RSG) are selective immunosuppressants that exhibit primary efficacy in the treatment of rheumatoid arthritis through targeted inhibition of activated T cells. In this study, we aimed to investigate the potential application of RSG in the treatment of psoriasis and elucidate its mechanism of action and material basis. Our findings revealed significant improvements upon administration of RSG in an imiquimod (IMQ)-induced psoriasis model. These improvements were characterized by a remarkable increase in the number of tail scales in mice and a substantial amelioration of skin erythema, ulceration, and flaking. By transcriptome sequencing and T-cell flow sorting assay, we identified notable effects of RSG on the modulation of various cellular processes. Specifically, RSG prominently down-regulated the Th17/Treg ratio in damaged skin tissues and reduced the proportion of G2 phase cells. Furthermore, RSG exhibited a stimulatory effect on the proliferation and differentiation of epithelial cells. Of particular interest, we discovered that ß-sitosterol, sitostenone, stigmasterol, smiglanin, and cinchonain Ib displayed potent inhibitory effects on the IL-17-mediated inflammatory response in HaCaT cells. In summary, our study highlights the therapeutic potential of RSG in the treatment of psoriasis, attributed to its ability to regulate the Th17/Treg balance. These findings contribute to the development of new indications for RSG and provide a solid theoretical foundation for further exploration in this field.

The relationship between technology acceptance and self-regulated learning: the mediation roles of intrinsic motivation and learning engagement.

The current study assessed 495 middle school students in China using self-report questionnaires, to examine the multiple mediating effects of intrinsic motivation and learning engagement (vitality, dedication and absorption) in the relations between technology acceptance and students' self-regulated learning. The results indicated that technology acceptance had a significant impact on self-regulated learning, intrinsic motivation mediated the relations between technology acceptance and self-regulated learning, and learning engagement (vigor, dedication, and absorption) mediated the relations between technology acceptance and self- regulated learning. The findings suggested that students' perceived acceptance of technology can help them improve their ability to engage in self-regulated learning by enhancing intrinsic motivation and increasing learning engagement. The results expand our understanding of self-regulated learning for Chinese middle school students in the context of information technology, and have substantial theoretical and practical implications for educator and relevant researchers.

Mupirocin enhances the biofilm formation of Staphylococcus epidermidis in an atlE-dependent manner.

The pathogenicity of Staphylococcus epidermidis is largely attributed to its exceptional ability to form biofilms. Here, we report that mupirocin, an antimicrobial agent widely used for staphylococcal decolonization and anti-infection, strongly stimulates the biofilm formation of S. epidermidis. Although the polysaccharide intercellular adhesin (PIA) production was unaffected, mupirocin significantly facilitated extracellular DNA (eDNA) release by accelerating autolysis, thereby positively triggering cell surface attachment and intercellular agglomeration during biofilm development. Mechanistically, mupirocin regulated the expression of genes encoding for the autolysin AtlE as well as the programmed cell death system CidA-LrgAB. Critically, through gene knockout, we found out that deletion of atlE, but not cidA or lrgA, abolished the enhancement of biofilm formation and eDNA release in response to mupirocin treatment, indicating that atlE is required for this effect. In Triton X-100 induced autolysis assay, mupirocin treated atlE mutant displayed a slower autolysis rate compared with the wild-type strain and complementary strain. Therefore, we concluded that subinhibitory concentrations of mupirocin enhance the biofilm formation of S. epidermidis in an atlE dependent manner. This induction effect could conceivably be responsible for some of the more unfavourable outcomes of infectious diseases.