Comparison of the value of adipose tissues in abdomen and lumbar vertebra for predicting disease activity in Crohn's disease: A preliminary study based on CSE-MRI.

BACKGROUND: To compare the value of adipose tissues in abdomen and lumbar vertebra for predicting Crohn's disease (CD) activity based on chemical shift encoded magnetic resonance imaging (CSE-MRI). METHODS: 84 CD patients were divided into remission, mild, and moderate-severely groups based on CD activity index (CDAI). Differences in different adipose parameters [subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), mesenteric fat index (MFI), and bone marrow fat fraction (BMFF)] and blood inflammatory indicators among three groups, as well as the correlation of above parameters and CDAI were analyzed. The areas under the receiver-operating characteristic curves (AUCs) for the parameters selected by multivariate logistic regression analysis for predicting active CD were calculated. RESULTS: There were no significant differences in VAT and MFI among three groups (both P > 0.05). The cross-sectional areas of SAT in moderate-severe group were significantly lower than those in remission group (P = 0.014). BMFF values of remission group were significantly higher than those in the mild and moderate-severe groups (both P < 0.001). BMFF was negatively correlated with CDAI (r = -0.595, P < 0.001). SAT exhibited no significant correlation with CDAI. Erythrocyte sedimentation rate (ESR) and BMFF were the independent predictors of CDAI. Both combined had a higher diagnostic efficacy for active CD with an AUC of 0.895. CONCLUSIONS: BMFF is the best marker for predicting CD activity in fat parameters of abdomen and lumbar vertebra based on CSE-MRI. The model based on BMFF and ESR has a high efficiency in predicting active CD. TRIAL REGISTRATION: No. 22 K164 (Registered 18-07-2022).

Clearness qualitative comparative analysis of the spread of TikTok health science knowledge popularization accounts.

Objective: This study analyzed the popularity of TikTok health knowledge popularization accounts with the objective of creating a template for accounts suited to widely disseminating information, thereby enhancing the public's access to health knowledge on a broader scale. Methods: This study is based on 40 Chinese TikTok short video accounts that were active from February to April 2022 and were engaged in health science popularization. Data were validated by structured calibration using three qualitative anchors. It employs the "content-context" and the elaboration likelihood models as the theoretical framework. A qualitative comparative analysis is used to explore the factors affecting the popularity of this type of account mechanism. Results: Among the nine variables involved in the calculation, one reached 0.909091, demonstrating that the number of followers was both a necessary factor and a condition for the popularity of short health science video accounts. There were 16 paths in the complex solution with a consistency of 1, and their overall coverage reached 0.878788, indicating that approximately 87% of the cases could be explained. From the spread of the content and communication situation, professional medical knowledge, current hot topics, professionals, and serious issues were the most likely combinations for rapid spread. From the perspective of the central and edge paths, "likes" exceeding 100,000 and fans exceeding 1 million were essential combinations. Conclusions: The dissemination of medical knowledge has gained significant traction, especially with regard to trending and popular topics. When it comes to the tone of communication, a serious style proved effective in fostering what can be termed "hot communication." From the standpoint of central and peripheral paths, it is crucial that the number of likes in the past month and the total number of fans surpass 100,000 and one million, respectively.

Designing Surface-Defect Engineering to Enhance the Solar-Driven Conversion of CO2 to C2 Products over Zn3In2S6/ZnS.

The manipulation of electronic structure and prevention of photogenerated carriers from being quenched in bulk defects during the photocatalytic CO2 reduction reaction (CRR) have been effectively demonstrated through surface vacancy and defect engineering. In this work, the electronic structure on the surface of Zn3In2S6/ZnS (ZIS/ZnS) is significantly modified by the introduction and control of the surface S vacancies (SV) through Ar-plasma treatment. EPR and XPS analyses confirmed that SV was exclusively present on the ZIS/ZnS surface. The resulting ZIS/ZnS heterojunction photocatalysts demonstrate an impressive 46.6% selectivity toward C2 products even in the absence of cocatalysts. The mechanism of photocatalytic CRR is further elucidated through in situ analysis. Theoretical calculations demonstrate that the presence of In and Zn atoms adjacent to SV significantly enhances the adsorption of CO2 and facilitates C-C coupling.

Research on wheel-legged robot based on LQR and ADRC.

The traditional two-wheeled self-balancing robot can travel quickly in a flat road environment, and it is easy to destabilize and capsize when passing through a bumpy road. To improve the passing ability of a two-wheeled robot, a new wheel-legged two-wheeled robot is developed. A seven-link leg structure is proposed through the comprehensive design of mechanism configuration, which decouples the balanced motion and leg motion of the robot. Based on the Euler-Lagrange method, the dynamic model of the system is obtained by applying the nonholonomic dynamic Routh equation in the generalized coordinate system. The robot's state space is divided according to the robot's height, and the Riccati equation is solved in real-time by the linear quadratic regulator (LQR) method to complete the balance and motion control of the robot. The robot leg motion control is achieved based on the active disturbance rejection control (ADRC) way. A robot simulation model is built on Recurdyn to verify the algorithm's feasibility, and then an experimental prototype is built to demonstrate the algorithm's effectiveness. The experimental results show that the control method based on LQR and ADRC can make the robot pass through the bumpy road.

The novel small molecule BH3 mimetic nobiletin synergizes with vorinostat to induce apoptosis and autophagy in small cell lung cancer.

Small cell lung cancer (SCLC) is a highly lethal subtype of lung cancer with few therapeutic options; therefore, the identification of new targets and drugs with potent combination therapy is desirable. We previously screened BH3 mimetics from a natural product library, and in this study, we validated nobiletin as a BH3 mimetic. Specifically, we observed its combination potential and mechanism with vorinostat in SCLC in vitro and in vivo. The results showed that combination treatment with nobiletin and vorinostat reduced the proliferation of SCLC H82 cells and increased the levels of apoptotic proteins such as cleaved caspase-9 and cleaved PARP. The combination treatment increased LC3-II expression and induced autophagic cell death. In addition, this treatment significantly inhibited H82 cell xenograft SCLC tumor growth in nude mice. The combination treatment with nobiletin and vorinostat efficiently increased autophagy by inhibiting the PI3K-AKT-mTOR pathway and promoting dissociation of the BCL-2 and Beclin 1 complex, increasing the level of isolated Beclin 1 to stimulate autophagy. Molecular docking and surface plasmon resonance analysis showed that nobiletin stably bound to the BCL-2, BCL-XL and MCL-1 proteins with high affinity in a concentration-dependent manner. These results suggest that nobiletin is a BH3-only protein mimetic. Furthermore, the combination of nobiletin with vorinostat increased histone H3K9 and H3K27 acetylation levels in SCLC mouse tumor tissue and enhanced the expression of the BH3-only proteins BIM and BID. We conclude that nobiletin is a novel natural BH3 mimetic that can cooperate with vorinostat to induce apoptosis and autophagy in SCLC.

Experimental and Numerical Study on Hysteretic Behavior of Frictional Energy Dissipation Steel Truss.

In this study, the hysteretic behavior of a novel frictional energy dissipation steel truss (FED-ST) is examined. The proposed FED-ST incorporates a friction damper with brass as the friction material into the top chord of traditional truss to improve the seismic performance of the staggered truss framing systems. A FED-ST specimen with a scale of 1:2.5 was subjected to a hysteresis test. The hysteretic behavior, ductility, and energy dissipation capability were analyzed considering the test findings. It is demonstrated that the FED-ST specimen has favorable ductility and an energy dissipation capacity that is 7.3 times more than that of a conventional truss specimen. The test findings were then used to compare and validate a finite element (FE) model. The FE analysis results are in strong agreement with the test results, demonstrating the validity of the modeling approach. To further investigate the impact of the cover plate width on the behavior of the FED-ST, preliminary parametric research was also carried out.

Discovery of phosphonate derivatives containing different substituted 1,2,3-triazole motif as promising tobacco mosaic virus (TMV) helicase inhibitors for controlling plant viral diseases.

BACKGROUND: The discovery and identification of targets is of far-reaching significance for developing novel pesticide candidates and increasing the probability of success. To explore and identify highly effective tobacco mosaic virus (TMV) helicase-targeted lead structures, a series of novel phosphonate derivatives containing a 1,2,3-triazole motif were rationally engineered and their antiviral activity was assessed. RESULTS: Bioassay results showed that the optimized B17 exhibited more potent curative activity (EC50 = 271.5 µg mL-1 ) against TMV in vivo, which was superior to that of commercial Ribavirin (EC50 = 689.3 µg mL-1 ). B17 presented a stronger binding capacity through binding analysis with helicase, affording a corresponding value of 12.7 µM. Enzyme activity assay showed B17 exhibited excellent inhibitory activity on TMV helicase (39.2% at 300 µM). Furthermore, molecular docking simulations demonstrated that B17 displayed strong hydrogen-bond interactions (2.1, 2.1, 2.2, and 3.2 Å) with Ala-33, Gly-10, Gly-8, and Glu-217 of TMV helicase. Encouragingly, transmission electron microscopy analysis revealed that B17 could remarkably disrupt surface morphology and inhibit TMV proliferation. Additionally, these compounds also displayed potential anti-CMV (cucumber mosaic virus) and antipathogens (Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri) by expanding their applications in agriculture. CONCLUSION: Current research demonstrated that B17 could be considered as a potential antiviral agent alternative though targeting TMV helicase. © 2023 Society of Chemical Industry.

High-performance long-distance discrete-modulation continuous-variable quantum key distribution.

We experimentally demonstrate a high-rate discretely modulated continuous-variable quantum key distribution over 80-km standard single-mode fiber with a 2.5 Gbaud, 16-symbol, two-ring constellation. With the help of well-designed digital signal processing algorithms, the excess noise of the system can be effectively suppressed. The achieved secret key rates are 49.02 Mbits/s, 11.86 Mbits/s, and 2.11 Mbits/s over 25-km, 50-km, and 80-km optical fiber, respectively, and achieve 67.4%, 70.0%, and 66.5% of the secret key rate performance of a Gaussian-modulated protocol. Our work shows that it is feasible to build a high-performance, long-distance continuous-variable quantum key distribution system with only a small constellation size.

A new NASH model in aged mice with rapid progression of steatohepatitis and fibrosis.

Non-alcoholic fatty liver disease (NAFLD) has a high prevalence worldwide, with a significant proportion of patients progressing into non-alcoholic steatohepatitis (NASH) and further into cirrhosis and hepatocellular carcinoma (HCC). Most of the current animal models of NASH have limitations, such as incompatibility with human pathogenesis characteristics or long induction periods, which severely limit the development of new drugs and preclinical studies for NASH. We investigated the progression of NASH and fibrosis, as well as metabolic indicators, at different time points in aged mice induced by the Gubra Amylin NASH (GAN) diet, a high-fat, high-sugar, high-cholesterol diet, and attempted to establish a rapid and useful mouse model of NASH. Young and aged C57BL/6 mice were induced on a normal chow or GAN diet for 12 and 21 weeks, respectively. After 12 weeks of induction, aged mice developed NASH, including hepatic steatosis, lobular inflammation and hepatic ballooning, and the phenotype was more severe compared with young mice. After 21 weeks of induction, aged mice developed hepatic fibrosis, which greatly shortened the induction time compared with young mice. Furthermore, analysis of immune cell infiltration in the liver by flow cytometry elucidated the changes of multiple immune cells during the pathogenesis of NASH. These findings suggest that aged mice may develop NASH and fibrosis more rapidly under GAN diet induction, which may significantly shorten the period for preclinical studies of NASH.

Polyester Nanoparticles and Polyurethane Nanocapsules Deliver Pirfenidone To Reduce Fibrosis and Scarring.

Pirfenidone has been shown to reduce fibrosis and modulate inflammation associated with conditions from pulmonary fibrosis to rheumatoid arthritis. It may also be useful for ocular diseases as well. However, for pirfenidone to be effective, it needs to be delivered to the tissue of interest, which, in the case of the eye, in particular, motivates the need for a system that permits local, long-term delivery to address the continuing pathology of the, condition. We investigated a set of delivery systems to determine the impact of encapsulation materials on the loading and delivery of pirfenidone. While the polyester system based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles exhibited higher loading than a polyurethane-based nanocapsule system, the delivery was short, with 85% of the drug being released in 24 h and no measurable drug after 7 days. Addition of different poloxamers impacted the loading but not the release of the drug. In contrast, the polyurethane nanocapsule system delivered 60% of the drug over the first 24 h and the remainder over the next 50 days. Furthermore, the polyurethane system permitted on-demand delivery via ultrasound. Being able to tune the amount of drug delivered via ultrasound has the potential to tailor the delivery of pirfenidone to modulate inflammation and fibrosis. We used a fibroblast scratch assay to confirm the bioactivity of the released drug. This work provides multiple platforms for the delivery of pirfenidone locally and over time in both passive and on-demand formulations with the potential to address a range of inflammatory and fibrotic conditions.

Hierarchical 3D Porous Hydrogen-Substituted Graphdiyne for High-Performance Electrochemical Lithium-Ion Storage.

Graphdiyne (GDY) has realized significant achievements in lithium-ion batteries (LIBs) because of its unique π-conjugated skeleton with sp- and sp2-hybridized carbon atoms. Enriching the accessible surface areas and diffusion pathways of Li ions can realize more storage sites and rapid transport dynamics. Herein, three-dimensional porous hydrogen-substituted GDY (HsGDY) is developed for high-performance Li-ion storage. HsGDY, fabricated via a versatile interface-assisted synthesis strategy, exhibits a large specific surface area (667.9 m2 g-1), a hierarchical porous structure, and an expanded interlayer space, which accelerate Li-ion accessibility and lithiation/delithiation. Owing to this high π-conjugated, conductive, and porous framework, HsGDY exhibits a large reversible capacity (930 mA h g-1 after 100 cycles at 1 A g-1), superior cycle (720 mA h g-1 after 300 cycles at 1 A g-1), and rate (490 mA h g-1 at 5 A g-1) performances. Density functional theory calculations of the low diffusion barrier in the lamination and vertical directions further reveal the fast Li-ion transport kinetics of HsGDY. Additionally, a LiCoO2-HsGDY full cell is constructed, which exhibits a good practical charge/discharge capacity of 128 mA h g-1 and stable cycling behavior. This study highlights the advanced design of next-generation LIBs to sustainably develop the new energy industry.

Experimental and Theoretical Studies on Hysteretic Behavior of Friction Energy Dissipation Composite Chord under Quasi-Static Tests.

To improve the seismic performance of a staggered truss steel framing system, the basic force unit in the truss system is replaced by a friction energy dissipation truss. The difference between a friction energy dissipation truss and an ordinary truss is that the upper chord is a friction energy dissipation composite chord. In this paper, we investigate the effects of the number of bolts and the friction surface on the energy dissipation capacity of the chord by a quasi-static test on six composite chord specimens at a scale of 1:2. The results show that the hysteresis curves of friction energy dissipation composite chords are ideal rectangles, and the energy dissipation capacity is excellent. The more bolts there are in the specimen, the slower the energy dissipation capacity of the chord decreases. Among the different friction surface specimens, the energy dissipation capacity of the aluminum friction plate specimen decays the fastest, while the energy dissipation capacity of the shot-blasted treated specimen decays substantially after the first cycle. Friction plates can improve the stability of the hysteresis properties. Based on the test results, this paper proposes a calculation method for the ultimate bearing capacity of the composite chord, which provides a basis for the design of a friction energy dissipation truss. In addition, we studied the effects of different bolt clamping forces and slotted bolt hole lengths on the energy dissipation capacity of composite chords by establishing a finite element analysis. It was shown that as the clamping force of the bolt increases, the energy dissipation capacity of the specimen becomes stronger but the stability decreases. The energy dissipation capacity of the chord is close to a linear relationship with the slotted bolt hole lengths; thus, increasing the slotted bolt hole lengths within the allowable range of inter-story drifts can enhance the energy dissipation capacity of the chord. Finally, we propose the design method of the angle steel by analyzing the force of the chord.

A ketogenic diet improves vascular hyperpermeability in type 2 diabetic mice by downregulating vascular pescadillo1 expression.

The role of pescadillo1 (PES1) in regulating vascular permeability has been unknown. This study probes the role of PES1 and its mediated molecular mechanism in modulating vascular hyperpermeability in diabetic mice. Male C57BL/6J and db/db mice were fed a standard diet and a ketogenic diet (KD). Meanwhile, mouse vascular endothelial cells (MVECs) were treated with ß-hydroxybutyric acid (ß-HB), Pes1 siRNA or a Pes1 overexpression plasmid. Additionally, knockout (KO) of Pes1 in mice was applied. After 12 weeks of feedings, enhanced vascular PES1 expression in diabetic mice was inhibited by the KD. The suppression of PES1 was also observed in ß-HB-treated MVECs. In mice with Pes1 KO, the levels of vascular VEGF and PES1 were attenuated, while the levels of vascular VE-cadherin, Ang-1 and Occludin were upregulated. Similar outcomes also occurred after the knockdown of Pes1 in cultured MVECs, which were opposite to the effects induced by PES1 overexpression in MVECs. In vitro and in vivo experiments showed that high glucose concentration-induced increases in vascular paracellular permeability declined after MVECs were treated by ß-HB or by knockdown of Pes1. In contrast, increases in vascular permeability were induced by overexpression of Pes1, which were suppressed by coadministration of ß-HB in cultured endothelial cells. Similarly declines in vascular permeability were found by Pes1 knockdown in diabetic mice. Mechanistically, ß-HB decreased PES1-facilitated ubiquitination of VE-cadherin. The KD suppressed the diabetes-induced increase in PES1, which may result in vascular hyperpermeability through ubiquitination of VE-cadherin in type 2 diabetic mice.

Exploiting Natural Maltol for Synthesis of Novel Hydroxypyridone Derivatives as Promising Anti-Virulence Agents in Bactericides Discovery.

Anti-infection strategies based on suppression of bacterial virulence factors represent a crucial direction for the development of new antibacterial agents to address the resistance triggered by traditional drugs'/pesticides' bactericidal activity. To identify and obtain more effective and diverse molecules targeting virulence, we prepared a series of 3-hydroxy-2-methyl-1-pyridin-4-(1H)-one derivatives and evaluated their antibacterial behaviors. Compound B6 exhibited the highest bioactivity, with half-maximal effective concentration (EC50) values ranging fro9m 10.03 to 30.16 µg mL-1 against three plant pathogenic bacteria. The antibacterial mechanism showed that it could considerably reduce various virulence factors (such as extracellular enzymes, biofilm, and T3SS effectors) and inhibit the expression of virulence factor-related genes. In addition, the control efficiency of compound B6 against rice bacterial leaf blight at 200 µg mL-1 was 46.15-49.15%, and their control efficiency was improved by approximately 12% after the addition of pesticide additives. Thus, a new class of bactericidal candidates targeting bacterial virulence factors was developed for controlling plant bacterial diseases.

Novel cinnamic acid derivatives as a versatile tool for developing agrochemicals for controlling plant virus and bacterial diseases by enhancing plant defense responses.

BACKGROUND: Plant pathogens have led to large yield and quality losses in crops worldwide. The discovery and study of novel agrochemical alternatives based on the chemical modification of bioactive natural products is a highly efficient approach. Here, two series of novel cinnamic acid derivatives incorporating diverse building blocks with alternative linking patterns were designed and synthesized to identify their antiviral capacity and antibacterial activity. RESULTS: The bioassay results demonstrated that most cinnamic acid derivatives had excellent antiviral competence toward tobacco mosaic virus (TMV) in vivo, especially compound A5 (median effective concentration [EC50 ] = 287.7 µg mL-1 ), which had a notable protective effect against TMV when compared with the commercial virucide ribavirin (EC50  = 622.0 µg mL-1 ). In addition, compound A17 had a protective efficiency of 84.3% at 200 µg mL-1 against Xac in plants. Given these outstanding results, the engineered title compounds could be regarded as promising leads for controlling plant virus and bacterial diseases. Preliminary mechanistic studies suggest that compound A5 could enhance the host's defense responses by increasing the activity of defense enzymes and upregulating defense genes, thereby suppressing phytopathogen invasion. CONCLUSION: This research lays a foundation for the practical application of cinnamic acid derivatives containing diverse building blocks with alternative linking patterns in pesticide exploration. © 2023 Society of Chemical Industry.

Trace Cu+-dominated band structure engineering in CuxIn0.25ZnSy for promoting photocatalytic H2 evolution.

As an attractive semiconductor photocatalyst, (CuInS2)x-(ZnS)y has been intensively studied in photocatalysis, due to its unique layered structure and stability. Here, we synthesized a series of CuxIn0.25ZnSy photocatalysts with different trace Cu+-dominated ratios. The results show that doping with Cu+ ions leads to an increase in the valence state of In and the formation of a distorted S structure, simultaneously inducing a decrease in the semiconductor bandgap. When the doping amount of Cu+ ions is 0.04 atomic ratio to Zn, the optimized Cu0.04In0.25ZnSy photocatalyst with a bandgap of 2.16 eV shows the highest catalytic hydrogen evolution activity (191.4 µmol.h-1). Subsequently, among the common cocatalysts, Rh loaded Cu0.04In0.25ZnSy gives the highest activity of 1189.8 µmol·h-1, corresponding to an apparent quantum efficiency of 49.11 % at 420 nm. Moreover, the internal mechanism of photogenerated carrier transfer between semiconductors and different cocatalysts is analyzed by the band bending phenomenon.

New Inspiration of 1,3,4-Oxadiazole Agrochemical Candidates: Manipulation of a Type III Secretion System-Induced Bacterial Starvation Mechanism to Prevent Plant Bacterial Diseases.

Discovering new anti-virulent agents to control plant bacterial diseases by preventing bacterial pathogenesis/pathogenicity rather than affecting bacterial growth is a sensible strategy. However, the effects of compound-manipulated bacterial virulence factors on host response are still not clear. In this work, 35 new 1,3,4-oxadiazole derivatives were synthesized and systematically evaluated for their anti-phytopathogenic activities. Bioassay results revealed that compound C7 possessed outstanding antibacterial activity in vitro (half-maximal effective concentration: 0.80 µg/mL) against Xanthomonas oryzae pv. oryzae (Xoo) and acceptable bioactivity in vivo toward rice bacterial leaf blight. Furthermore, virulence factor-related biochemical assays showed that C7 was a promising anti-virulent agent. Interestingly, C7 could indirectly reduce the inducible expression of host SWEET genes and thereby alleviate nutrient supply in the infection process of phytopathogenic bacteria. Our results highlight the potential of 1,3,4-oxadiazole-based agrochemicals for manipulating type III secretion system-induced phytopathogenic bacteria starvation mechanisms to prevent plant bacterial diseases.

Resistance-driven innovations in the discovery of bactericides: novel triclosan derivatives decorating isopropanolamine moiety as promising anti-biofilm agents against destructive plant bacterial diseases.

BACKGROUND: Controlling bacterial infections in plants is a major challenge owing to the appearance of resistant strains. As a physical barrier, the bacterial biofilm helps bacterial infections acquire drug resistance by enabling bacteria to accommodate complex and volatile environmental conditions and avoid bactericidal effects. Thus, developing new antibacterial agents with antibiofilm potency is imperative. RESULTS: A series of simple triclosan derivatives containing isopropanolamine moiety were elaborately designed and assessed for their antibacterial behavior. Bioassay results showed that some title compounds had excellent bioactivity against three destructive bacteria Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac) and Pseudomonas syringae pv. actinidiae (Psa). Notably, compound C8 displayed high bioactivities toward Xoo and Xac, with EC50 values were 0.34 and 2.11 µg mL-1 , respectively. In vivo trials revealed that compound C8 exhibited excellent protective activities against rice bacterial blight and citrus bacterial canker at 200 µg mL-1 , with control effectivenesses of 49.57% and 85.60%, respectively. Compound A4 had remarkably inhibitory activity toward Psa, with an EC50 value of 2.63 µg mL-1 , and demonstrated outstanding protective activity with a value of 77.23% against Psa in vivo. Antibacterial mechanisms indicated that compound C8 dose-dependently prevented biofilm formation and extracellular polysaccharide production. C8 also significantly weakened the motility and pathogenicity of Xoo. CONCLUSION: This study contributes to the development and excavation of novel bactericidal candidates with broad-spectrum antibacterial activity by targeting bacterial biofilm to control refractory plant bacterial diseases. © 2023 Society of Chemical Industry.

Novel spiro[chromanone-2,4'-piperidine]-4-one derivatives as potential inhibitors of fatty acid synthesis in pathogens: Design, synthesis, and biological evaluation.

Bacterial survival depends on membrane lipid homeostasis that enables to regulate lipid composition to adapt and optimize their growth in diverse environments. Therefore, the development of inhibitors that interfere with the bacterial fatty acid synthesis process is considered to be a promising tactic. In this study, 58 novel spirochromanone derivatives were prepared and their structure-activity relationship (SAR) was investigated. The bioassay results showed that all most of the compounds showed excellent biological activities, exampled by compounds B14, C1, B15, and B13, which had outstanding inhibitory activities toward various pathogenic bacteria with EC50 values of 0.78 µg/mL ∼3.48 µg/mL. Preliminary antibacterial behavior was studied by a series of biochemical assays including, but not limited to, fluorescence imaging patterns, GC-MS analysis, TEM images, and fluorescence titration experiments. Notably, compound B14 decreased the lipid content of the cell membrane, and increased cell membrane permeability, thereby destroying the integrity of the bacterial cell membrane. Further qRT-PCR results indicated that compound B14 interfered with the mRNA expression levels of fatty acid synthesis process-related genes including ACC, ACP, and Fab family genes. Herein, we highlight the promising bactericidal skeleton based on the spiro[chromanone-2,4'-piperidine]-4-one as a potential inhibitor of fatty acid synthesis.

Impact of homodyne receiver bandwidth and signal modulation patterns on the continuous-variable quantum key distribution.

In continuous-variable quantum key distribution (CV-QKD), the key information are encoded on quadratures of the optical field, which are measured via balanced homodyne detector (BHD). The bandwidth of the BHD is one of key parameters for precise characterization of quantum states. We establish a theoretical model to analyze the impact of the BHD bandwidth and signal modulation patterns on the channel parameters estimation of CV-QKD systems. Based on the proposed model, the secure key rate of a practical CV-QKD system under different BHD bandwidths and signal modulation patterns are investigated. Our results show that insufficient BHD bandwidth will result in wrong estimate of the transmission loss and excess noise, which significantly affects the performance of CV-QKD systems. Given the BHD bandwidth, there exists an optimal signal repetition rate that maximizes the secure key rate. The BHD bandwidth requirement of the QKD system increases with the transmission distance for large duty cycle pulse. Furthermore, the root raised-cosine pulse signal modulation performs better than the square pulse signal modulation in general.