Dynamics, circuit design, feedback control of a new hyperchaotic system and its application in audio encryption.

In this study, a 4D hyperchaotic system is constructed based on the foundation of a 3D Lü chaotic system. The newly devised hyperchaotic system possesses a sole equilibrium point, showcasing a simplified system structure that reduces complexity. This simplification offers a clearer opportunity for in-depth analysis of dynamic behaviors in the realm of scientific research. The proposed hyperchaotic system undergoes an in-depth examination of its dynamical characteristics, including chaotic attractors, equilibrium point stability, Lyapunov exponents' spectrum, and bifurcation diagram. Numerical analysis results reveal that the attractor of this hyperchaotic system exhibits highly complex, non-periodic, and fractal structural dynamics. Its motion demonstrates extreme sensitivity and randomness, even within a wide range of variations in parameter d, affirming its hyperchaotic properties with two positive Lyapunov exponents. Hyperchaotic bifurcation diagrams typically exhibit highly intricate structures, such as fractals, branches, and period doubling characteristics, signifying that even minor parameter adjustments can lead to significant changes in system behavior, presenting diversity and unpredictability. Subsequently, to further investigate the practical utility of this hyperchaotic system, a linear feedback control strategy is implemented. Through linear feedback control, the hyperchaotic system is stabilized at its unique equilibrium point. Experimental validation is conducted using both computer software simulation Matlab, electronic circuit simulation Multisim, and embedded hardware STM32. The results of these experiments consistently align, providing theoretical support for the application of this hyperchaotic system in practical domains. Finally, leveraging the hyperchaotic keys generated by this hyperchaotic system, audio encryption is achieved using a cross-XOR algorithm, which is then realized on the embedded hardware platform STM32. The results show that the audio encryption scheme based on the hyperchaotic system is feasible, and the method is simple to implement, has nonlinear characteristics and certain algorithm complexity, which can be applied to audio encryption, image encryption, video encryption, and more.

Characteristics and Discrimination of the Commercial Chinese Four Famous Vinegars Based on Flavor Compositions.

Shanxi aged vinegar (SAV), Zhenjiang aromatic vinegar (ZAV), Sichuan bran vinegar (SBV), and Fujian monascus vinegar (FMV) are the representative Chinese traditional vinegars. However, the basic differential compositions between the four vinegars are unknown. In this study, compositions of commercial vinegar were investigated to evaluate the influence of diverse technologies on their distinct flavor. Unlike amino acids and organic acids which were mostly shared, only five volatiles were detected in all vinegars, whereas a dozen volatiles were common to each type of vinegar. The four vinegars could only be classified well with all compositions, and difference analysis suggested the most significant difference between FMV and SBV. However, SAV, ZAV, and SBV possessed similar volatile characteristics due to their common heating treatments. Further, the correlation of identification markers with vinegars stressed the contributions of the smoking process, raw materials, and Monascus inoculum to SAV, SBV, and FMV clustering, respectively. Therefore, regardless of the technology modification, this basic process supported the uniqueness of the vinegars. This study contributes to improving the standards of defining the characteristics of types of vinegar.

Genome analysis provides insight into hyper-virulence of Streptococcus suis LSM178, a human strain with a novel sequence type 1005.

Streptococcus suis has been well-recognized as a zoonotic pathogen worldwide, and the diversity and unpredictable adaptive potential of sporadic human strains represent a great risk to the public health. In this study, S. suis LSM178, isolated from a patient in contact with pigs and raw pork, was assessed as a hyper-virulent strain and interpreted for the virulence based on its genetic information. The strain was more invasive for Caco-2 cells than two other S. suis strains, SC19 and P1/7. Sequence analysis designated LSM178 with serotype 2 and a novel sequence type 1005. Phylogenetic analysis showed that LSM178 clustered with highly virulent strains including all human strains and epidemic strains. Compared with other strains, these S. suis have the most and the same virulent factors and a type I-89 K pathogenicity island. Further, groups of genes were identified to distinguish these highly virulent strains from other generally virulent strains, emphasizing the key roles of genes modeling transcription, cell barrier, replication, recombination and repair on virulence regulation. Additionally, LSM178 contains a novel prophage conducive potentially to pathogenicity.

Physicochemical Properties and Biological Activities of Silver Carp Scale Peptide and Its Nanofiltration Fractions.

To explore the physicochemical properties and biological functions of silver carp scale peptide (SCSP), its molecular-weight fractions SCSP-I, II, and III obtained by nanofiltration were assessed for their solubility, emulsibility, free radical scavenging ability, effect on the proliferation of mouse B16 cells. The results showed that the solubility of each fraction of SCSP was higher than 90%, SCSP-II and III were higher than 95%. The antioxidant powers on ⦁OH, O 2 - ⦁ and Fe3+ were ranked as SCSP-III > SCSP-II > SCSP-I > SCSP. All fractions of SCSP had no toxic or side effects in mouse B16 melanoma cells experiments in vitro. At a concentration of 0.01 mg/mL, the tyrosinase activity of B16 cells in the SCSP-II fraction was significantly lower than that of the α-arbutin (P < 0.05), at 65.37%. The molecular weight distribution of SCSP was 399-1404 Dalton and 13 peptide sequences were detected. Among them, SCSP-II contained many hydrophobic amino acids, and SCSP-III stood out for combining arginine with hydrophobic amino acids. This may be the reason why the low molecular-weight SCSPs show the strong antioxidant activity and strong tyrosinase inhibition. The work provides a data base for the development of SCSP and increases the possibility of its application.

Microbiological Characteristics of Carbapenem-Resistant Enterobacteriaceae Clinical Isolates Collected from County Hospitals.

OBJECTIVE: To investigate the molecular characteristics of carbapenem-resistant Enterobacteriaceae (CRE) from county hospitals in China. MATERIALS AND METHODS: Forty-three sequential non-duplicate CRE strains (including 33 Klebsiella pneumoniae isolates, 4 Enterobacter cloacae isolates, 3 Escherichia coli isolates, 1 Serratia marcescens, 1 Morganella morganii and 1 Citrobacter freundii) were collected from 4 county hospitals and 2 municipal hospitals. Antimicrobial susceptibility testing was conducted by broth microdilution method, using 3-aminophenylboronic acid and EDTA and the modified carbapenem inactivation method (mCIM) to screen phenotype of carbapenemase. ß-Lactamases were characterized by polymerase chain reaction (PCR) and DNA sequencing. The transferability of bla NDM-5 was investigated by transformation experiment. Clonal relatedness was evaluated by pulsed-field gel electrophoresis and multilocus sequence typing . RESULTS: The results of antimicrobial susceptibility testing indicated that 43 CRE strains were resistant to most of the antimicrobial agents, except tigecycline and colistin. Overall, 93%, 93%, and 97.7% of these strains were resistant to imipenem, meropenem, and ertapenem, respectively. PCR and DNA sequencing indicated that 67.4% (29/43) were bla KPC-2 positive isolates, in which 3.4% (1/29) was coproduced with bla NDM-1. In addition, 7.0% (3/43), 4.7% (2/43), 4.7% (2/43), 2.3% (1/43), 2.3% (1/43) were bla NDM-1, bla NDM-16, bla NDM-4, bla NDM-5, bla IMP-4 positive isolates, respectively. The 29 bla KPC-2-positive isolates belonged to 12 different PFGE type and designated as ST11 (n=20) and ST15, ST39, ST116, ST667, ST2245, ST2338. The plasmid bearing bla NDM-5 could be transferred into recipient E. coli J53 through transformation. CONCLUSION: Our study indicated the dissemination of CRE between the tertiary hospitals and secondary hospitals.