Water-soluble biopolymers calcium polymalate derived from fermentation broth of Aureobasidium pullulans markedly alleviates osteoporosis and fatigue.

Osteoporosis is a prevalent condition characterized by bone loss and decreased skeletal strength, resulting in an elevated risk of fractures. Calcium plays a crucial role in preventing and managing osteoporosis. However, traditional calcium supplements have limited bioavailability, poor solubility, and adverse effects. In this study, we isolated a natural soluble biopolymer, calcium polymalate (PMACa), from the fermentation broth of the fungus Aureobasidium pullulans, to investigate its potential as an anti-osteoporosis therapeutic agent. Characterization revealed that linear PMA-Ca chains juxtaposed to form a porous, rod-like state, in the presence of Ca2+. In vivo mouse models demonstrated that PMA-Ca significantly promoted the conversion of serum calcium into bone calcium, and stimulated bone growth and osteogenesis. Additionally, PMA-Ca alleviated exercise fatigue in mice by facilitating the removal of essential metabolites, such as serum lactate (BLA) and blood urea nitrogen (BUN), from their bloodstream. In vitro studies further showed that PMA-Ca strengthened osteoblast cell activity, proliferation, and mineralization. And PMA-Ca upregulated the expression of some genes involved in osteoblast differentiation, indicating a potential correlation between bone formation and PMACa. These findings indicate that soluble PMA-Ca has the potential to be a novel biopolymer-based calcium supplement with sustainable production sourced from the fermentation industry.

Prevalence and correlates of sleep disturbance among adolescents in the eastern seaboard of China.

BACKGROUND: Sleep disturbances are serious public health issues that warrant increased attention, especially in adolescents. The aim of this study was to investigate the prevalence and factors associated with sleep disorders among urban adolescents in China. METHODS: This study utilized an online survey to assess the demographic characteristics and mental health status of secondary school students in Lianyungang City. The Patient Health Questionnaire-9 (PHQ-9) was used to evaluate sleep disturbances in adolescents. The seven-item Generalized Anxiety Disorder (GAD-7) assessed anxiety symptoms, and the Perceived Social Support Scale (PSSS) was used to measure perceived social support. RESULTS: Among 3443 adolescents, the prevalence of sleep disorders were 10.8%, with significantly higher proportions of sleep disorders (13.7% VS 8.3%, P < 0.001) among female adolescents when compared to males. Binary regression analysis revealed that anxiety symptoms (OR = 1.305, 95% CI: 1.269-1.342, P < 0.001) was risk factor for sleep disturbances, and significant other support (OR = 0.944, 95% CI: 0.896-0.994, P = 0.028) and good annual household income (OR = 0.616, 95% CI: 0.394-0.963, P = 0.034) were protective factors. Furthermore, multinomial logistic regression analysis showed that age, sex, and anxiety symptoms were associated with an elevated risk of experiencing more frequent sleep disturbances (all P < 0.05). CONCLUSIONS: We have found that 10.8% of adolescents experience sleep disorders, and it is evident that various factors can influence healthy sleeping. These results underscore the significance of addressing these factors to enhance sleep health among this population.

Limit cycles and chaos in the hybrid atom-optomechanics system.

We consider atoms in two different periodic potentials induced by different lasers, one of which is coupled to a mechanical membrane via radiation pressure force. The atoms are intrinsically two-level systems that can absorb or emit photons, but the dynamics of their position and momentum are treated classically. On the other hand, the membrane, the cavity field, and the intrinsic two-level atoms are treated quantum mechanically. We show that the mean excitation of the three systems can be stable, periodically oscillating, or in a chaotic state depending on the strength of the coupling between them. We define regular, limit cycle, and chaotic phases, and present a phase diagram where the three phases can be achieved by manipulating the field-membrane and field-atom coupling strengths. We also computed other observable quantities that can reflect the system's phase such as position, momentum, and correlation functions. Our proposal offers a new way to generate and tune the limit cycle and chaotic phases in a well-established atom-optomechanics system.

TiO2 Hollow Spheres With Flower-Like SnO2 Shell as Anodes for Lithium-Ion Batteries.

SnO2 is a promising anode material for lithium-ion batteries due to its high theoretical specific capacity and low operation voltage. However, its poor cycling performance hinders its commercial application. In order to improve the cycling stability of SnO2 electrodes, novel flower-like SnO2/TiO2 hollow spheres were prepared by facile hydrothermal method using carbon spheres as templates. Their flower-like shell and mesoporous structure highlighted a large specific surface area and excellent ion migration performance. Their TiO2 hollow sphere matrix and 2D SnO2 nano-flakes ensured good cycle stability. The electrochemical measurements indicated that novel flower-like SnO2/TiO2 hollow spheres delivered a high specific capacity, low irreversible capacity loss and superior rate performance. After 1,000 cycles at current densities of 200 mA g-1, the capacity of the flower-like SnO2/TiO2 hollow spheres was still maintained at 720 mAh g-1. Their rate capacity reached 486 mAh g-1 when the current densities gradually increase to 2,000 mA g-1.

[Vaginal microbiome: community characteristics and disease intervention].

The application of high-throughput sequencing technologies has greatly enhanced our understanding to the human microbiome. The causal relations between human microbiome and diseases have become a critical issue to elucidate disease development and develop precision medicine. Recently, the study about vaginal microbiome (the microbial flora that inhabits the female vagina) has received wide interests. It has been shown that dysbiosis of vaginal microbiome was closely related to the development of genital tract diseases. This article summarizes the interaction between vaginal microbiome and disease and the treatment for the dysbiosis of vaginal microbiome. The culturomics of virginal microbiome, engineered probiotics and synthetic microbiome were also proposed.

Coproduction of polymalic acid and liamocins from two waste by-products from the xylitol and gluconate industries by Aureobasidium pullulans.

The coproduction of polymalic acid (PMA) and liamocins, two important metabolites secreted by Aureobasidium pullulans, from two waste by-products from the xylitol and gluconate industries was investigated in shake flasks and fermentors, confirming that waste xylose mother liquor (WXML) could be utilized as an economical feedstock without any pretreatment. Gluconate could strengthen carbon flux and NADPH supply for the synergetic biosynthesis of PMA and liamocins. High PMA and liamocin titers of 82.9 ± 2.1 and 28.3 ± 2.7 g/L, respectively, were obtained from the coupled WXML and waste gluconate mother liquor (WGML) in batch fermentation, with yields of 0.84 and 0.25 g/g, respectively. These results are comparable to those obtained from renewable feedstocks. Economic assessment of the process revealed that PMA and liamocins could be coproduced from two by-products at costs of $1.48/kg or $0.67/kg (with liamocins credit), offering an economic and sustainable process for the application of waste by-products.

The non-Hermitian geometrical property of 1D Lieb lattice under Majorana's stellar representation.

The topological properties of non-Hermitian Hamiltonian is a hot topic, and the theoretical studies along this research line are usually based on the two-level non-Hermitian Hamiltonian (or, equivalently, a spin-1/2 non-Hermitian Hamiltonian). We are motivated to study the geometrical phases of a three-level Lieb lattice model (or, equivalently, a spin-1 non-Hermitian Hamiltonian) with the flat band in the context of a polariton condensate. The topological invariants are calculated by both winding numbers in the Brillouin zone and the geometrical phase of Majorana stars on the Bloch sphere. Besides, we provide an intuitive way to study the topological phase transformation with the higher spin, and the flat band offers a platform to define the topological phase transition on the Bloch sphere. According to the trajectories of the Majorana stars, we calculate the geometrical phases of the Majorana stars. We study the Lieb lattice with a complex hopping and find their phases have a jump when the parameters change from the trivial phase to the topological phase. The correlation phase of Majorana stars will rise along with the increase of the imaginary parts of the hopping energy. Besides, we also study the Lieb lattice with different intracell hopping and calculate the geometrical phases of the model using non-Bloch factor under the Majorana's stellar representation. In this case, the correlation phases will always be zero because of the normalized coefficient is always a purely real number and the phase transition is vividly shown with the geometrical phases of the Majorana stars calculated by the mean values of the total phases of both right and the joint left eigenstates.

Design, synthesis, biological evaluation, structure-activity relationship, and toxicity of clinafloxacin-azole conjugates as novel antitubercular agents.

Based on the advantages of azole molecules and fluoroquinolone drugs, we designed and synthesized 34 clinafloxacin-azole conjugates using fragment-based drug design and drug combination principles. The in vitro activities of the synthesized conjugates against Mycobacterium tuberculosis (H37Rv), Hela cell as well as Gram-positive and Gram-negative bacteria were assayed. The bioassay results revealed that most of the target molecules had anti-tuberculosis (anti-TB) activity, of which 14 compounds had very strong anti-TB activity [minimum inhibitory concentration (MIC) < 2 µM]. In addition, the compounds with strong activity towards H37Rv had weak activity towards Gram-negative and Gram-positive bacteria, showing obvious selectivity towards H37Rv. Predicted toxicity data indicated that 27 molecules were less toxic or equivalent to that of the original drug (clinafloxacin). Especially, it is demonstrated that compound TM2l exhibited the strongest anti-TB activity (MIC = 0.29 µM), low antibacterial activity, negligible toxicity, and good drug-likeness values, which can be considered as an ideal lead molecule for future optimization.

CD82 suppresses CD44 alternative splicing-dependent melanoma metastasis by mediating U2AF2 ubiquitination and degradation.

Melanoma is one of the most lethal forms of skin cancer because of its early metastatic spread. The variant form of CD44 (CD44v), a cell surface glycoprotein, is highly expressed on metastatic melanoma. The mechanisms of regulation of CD44 alternative splicing in melanoma and its pathogenic contributions are so far poorly understood. Here, we investigated the expression level of CD44 in a large set of melanocytic lesions at different stages. We found that the expression of CD44v8-10 and a splicing factor, U2AF2, is significantly increased during melanoma progression, whereas CD82/KAI1, a tetraspanin family of tumor suppressor, is reduced in metastatic melanoma. CD44v8-10 and U2AF2 expression levels, which are negatively correlated with CD82 levels, are markedly elevated in primary melanoma compared with dysplastic nevi and further increased in metastatic melanoma. We also showed that patients with higher CD44v8-10 and U2AF2 expression levels tended to have shorter survival. By using both in vivo and in vitro assays, we demonstrated that CD82 inhibits the production of CD44v8-10 on melanoma. Mechanistically, U2AF2 is a downstream target of CD82 and in malignant melanoma facilitates CD44v8-10 alternative splicing. U2AF2-mediated CD44 isoform switch is required for melanoma migration in vitro and lung and liver metastasis in vivo. Notably, overexpression of CD82 suppresses U2AF2 activity by inducing U2AF2 ubiquitination. In addition, our data suggested that enhancement of melanoma migration by U2AF2-dependent CD44v8-10 splicing is mediated by Src/focal adhesion kinase/RhoA activation and formation of stress fibers, as well as CD44-E-selectin binding reinforcement. These findings uncovered a hitherto unappreciated function of CD82 in severing the linkage between U2AF2-mediated CD44 alternative splicing and cancer aggressiveness, with potential prognostic and therapeutic implications in melanoma.

The synthetic thyroid hormone, levothyroxine, protects cholinergic neurons in the hippocampus of naturally aged mice.

The thyroid hormones, triiodothyronine and thyroxine, play important roles in cognitive function during the mammalian lifespan. However, thyroid hormones have not yet been used as a therapeutic agent for normal age-related cognitive deficits. In this study, CD-1 mice (aged 24 months) were intraperitoneally injected with levothyroxine (L-T4; 1.6 µg/kg per day) for 3 consecutive months. Our findings revealed a significant improvement in hippocampal cytoskeletal rearrangement of actin and an increase in serum hormone levels of L-T4-treated aged mice. Furthermore, the survival rate of these mice was dramatically increased from 60% to 93.3%. The Morris water maze task indicated that L-T4 restored impaired spatial memory in aged mice. Furthermore, level of choline acetyltransferase, acetylcholine, and superoxide dismutase were increased in these mice, thus suggesting that a possible mechanism by which L-T4 reversed cognitive impairment was caused by increased activity of these markers. Overall, supplement of low-dosage L-T4 may be a potential therapeutic strategy for normal age-related cognitive deficits.

Design, synthesis, and biological evaluation of dihydroartemisinin-fluoroquinolone conjugates as a novel type of potential antitubercular agents.

Tuberculosis remains a global public health problem in recent years. To develop novel type of potential antitubercular agents, twelve novel dihydroartemisinin-fluoroquinolone (DHA-FQ) conjugates (three types of molecules) were gradually designed and conveniently synthesized. All the newly synthesized conjugates were well characterized and evaluated against different Mycobacterium tuberculosis strains in vitro. The screening results showed that five DHA-FQ conjugates were active toward M. tuberculosis H37Rv, and compound 3a exhibited the strongest inhibitory activity (MIC=0.0625 µg/mL), which was comparable to the positive control Moxifloxacin and even stronger than Ofloxacin. Conjugates 2a and 3a also displayed comparable activities against various clinically isolated sensitive and resistant M. tuberculosis strains (MIC=0.125-16 µg/mL) to Moxifloxacin. All target compounds possessed selective anti-M. tuberculosis ability. Preliminary structure-activity relationship demonstrated that short linker between DHA and FQ was favorable for strong antitubercular activity. This study provides a new clue for the development of novel antitubercular lead molecules.

Characterization of the IncA/C plasmid pSCEC2 from Escherichia coli of swine origin that harbours the multiresistance gene cfr.

OBJECTIVES: To determine the complete nucleotide sequence of the multidrug resistance plasmid pSCEC2, isolated from a porcine Escherichia coli strain, and to analyse it with particular reference to the cfr gene region. METHODS: Plasmid pSCEC2 was purified from its E. coli J53 transconjugant and then sequenced using the 454 GS-FLX System. After draft assembly, predicted gaps were closed by PCR with subsequent sequencing of the amplicons. RESULTS: Plasmid pSCEC2 is 135 615 bp in size and contains 200 open reading frames for proteins of ≥100 amino acids. Analysis of the sequence of pSCEC2 revealed two resistance gene segments. The 4.4 kb cfr-containing segment is flanked by two IS256 elements in the same orientation, which are believed to be involved in the dissemination of the rRNA methylase gene cfr. The other segment harbours the resistance genes floR, tet(A)-tetR, strA/strB and sul2, which have previously been found on other IncA/C plasmids. Except for these two resistance gene regions, the pSCEC2 backbone displayed >99% nucleotide sequence identity to that of other IncA/C family plasmids isolated in France, Chile and the USA. CONCLUSIONS: The cfr gene was identified on an IncA/C plasmid, which is well known for its broad host range and transfer and maintenance properties. The location on such a plasmid will further accelerate the dissemination of cfr and co-located resistance genes among different Gram-negative bacteria. The genetic context of cfr on plasmid pSCEC2 underlines the complexity of cfr transfer events and confirms the role that insertion sequences play in the spread of cfr.

A novel peptide delivers plasmids across blood-brain barrier into neuronal cells as a single-component transfer vector.

There is no data up to now to show that peptide can deliver plasmid into brain as a single-component transfer vector. Here we show that a novel peptide, RDP (consisted of 39 amino acids), can be exploited as an efficient plasmid vector for brain-targeting delivery. The plasmids containing Lac Z reporter gene (pVAX-Lac Z) and BDNF gene (pVAX-BDNF) are complexed with RDP and intravenously injected into mice. The results of gel retardation assay show that RDP enables to bind DNA in a dose-dependent manner, and the X-Gal staining identity that Lac Z is specifically expressed in the brain. Also, the results of Western blot and immunofluorescence staining of BDNF indicate that pVAX-BDNF complexed with RDP can be delivered into brain, and show neuroprotective properties in experimental Parkinson's disease (PD) model. The results demonstrate that RDP enables to bind and deliver DNA into the brain, resulting in specific gene expression in the neuronal cells. This strategy provides a novel, simple and effective approach for non-viral gene therapy of brain diseases.

Brucella virulence mechanisms and implications in novel vaccines and drugs.

Brucellosis, an infection caused by Brucella spp., is a common zoonosis in many parts of world. Human chronic infection is successfully established through contact with infected animals or their dirty products. The capacity of establishing and maintaining this persistent infection in the phagosomal compartment of host macro-phages is critical to their ability to produce chronic infections in their mammalian hosts. Bacterial virulence mechanisms play an important role in regulating during the infectious process, both to optimize the functioning of the virulence factors in promoting survival and thwarting host defenses and to produce an effective immune response against these virulence components. The availability of the genomic sequences and molecular strategies such as gene mutant technique provide an opportunity to identify the virulence mechanisms of Brucella. It will greatly accelerate our understanding of the infection of this pathogen and give us more clues to exploit new vaccines and drugs.

Complete genome sequence of Brucella abortus 134, a biovar 1 strain isolated from human.

Brucella abortus is one of the common pathogens causing brucellosis in China. Here, we report the genome sequence of B. abortus strain 134, a strain isolated from a human patient and belonging to biovar 1, the most highly represented biovar among B. abortus strains in China.

Complete genome sequence of Brucella canis strain 118, a strain isolated from canine.

Brucella canis infects several species of animals, and canine is the preferred host. Genome sequences of strains from different hosts are valuable for comparative analysis of host adaptation and microevolution. Here, we report the genome sequence of Brucella canis strain 118, a strain isolated from canine.

[Zebrafish as a model animal for the study of blood-brain barrier permeability by biomolecules].

Blood-brain barrier (BBB) is the major obstacle for drug delivery into the central nervous system (CNS). However, there is no ideal model animal for the study of BBB permeability till now. Currently zebrafish (Danio rerio) has emerged as a powerful model organism for the study of vertebrate biology. In this study, the feasibility of using zebrafish as model animal was investigated for BBB permeability by comparing the results of administration of BBB-penetrating peptide and protein to mouse and zebrafish. The results showed that the BBBs of mouse and zebrafish were similar in molecular permeability. Additionally, zebrafish has advantageous features as a model animal, such as small size, fertile and easy to breed. Therefore, it is suggested that zebrafish may be a favored model for the study of BBB permeability.

Targeted delivery of large fusion protein into hippocampal neurons by systemic administration.

Targeted delivery of proteins into the hippocampus has not yet been achieved. Here, we show that systemic administration of the ß-galactosidase, fused to a 43-amino-acid peptide derived from rabies virus glycoprotein (RVG), results in targeted delivery of the fusion protein into the hippocampal neurons. This approach may enable the development of protein therapy for neurodegenerative diseases, such as Alzheimer's disease. This result may open new possibilities in using neurotropic virus glycoprotein-derived peptides for targeted delivery of therapeutic molecules into local brain regions.

In vitro inhibition of classical swine fever virus replication by siRNAs targeting Npro and NS5B genes.

Classical swine fever (CSF) is a highly contagious disease of pigs, which causes important economic losses worldwide. In the present study, the specific effect of RNA interference on the replication of CSF virus (CSFV) was explored. Three species of small interfering RNA (siRNA), targeting different regions of CSFV Npro and NS5B genes, were prepared by in vitro transcription. After transfection of PK-15 cells with each of the siRNAs followed by infection with CSFV, the viral proliferation within the cells was examined by indirect immunofluorescence microscopy. At 72 h post-infection, only a few siRNA-treated cells were positive for viral antigen staining, while most untreated virus-infected cells were positive. Treatment with the siRNAs caused a 4-12-fold reduction in viral genome copy number as assessed by real time RT-PCR. Transfection with the siRNAs also suppressed the production of infectious virus by up to 467-fold as assessed by TCID50 assay. These results suggested that the three species of siRNAs can efficiently inhibit CSFV genome replication and infectious virus production, with the inhibition persisting for 72-84 h.

[Replicative kinetics of classical swine fever virus in PK-15 cells].

In order to understand the replication kinetics of classical swine fever virus (CSFV) in in vitro cells PK-15 cells were seeded in 96-well tissues culture plates. After overnight incubation at 37 degrees C in 5% CO2 environment when growing to 80% confluence, the cells were infected with CSFV strain Shimen at 100 TCID50 per well. At various time post infection (p.i.) the replication of the virus in the cells were analyzed repectively by detection of viral antigen using indirect immunofluorescent assay (IFA), RNA replication using reverse transcription real-time PCR and viral production using titration of TCID50. In the results of the IFA the viral antigen could be detected as early as 8hrs p.i. and at 72h hrs p.i. almost all cells showed positive staining, the real-time PCR showed that the synthesis of viral genomic RNA was gradually increased between 8-24 hrs p.i. and reached its peak at 72 hrs p.i.. However, the synthesis of negative strand RNA was maintained at a low level for a whole period of culture although it could be detected at 8hrs p.i.. Titration of TCID50 demonstrated that the production of live virions increased at 8h and peaked between 48 - 72 hrs p.i. without significant lose of titer.