Direct evidences for inner-shell electron-excitation by laser induced electron recollision

Extreme ultraviolet (XUV) attosecond pulses, generated by a process known as laser-induced electron recollision, are a key ingredient for attosecond metrology, providing a tool to precisely initiate and probe sub-femtosecond dynamics in the microcosms of atoms, molecules and solids[1]. However, with the current technology, extending attosecond metrology to scrutinize the dynamics of the inner-shell electrons is a challenge, that is because of the lower efficiency in generating the required soft x-ray \hbar\omega>300 eV attosecond bursts and the lower absorption cross-sections in this spectral range. A way around this problem is to use the recolliding electron to directly initiate the desired inner-shell process, instead of using the currently low flux x-ray attosecond sources.Such an excitation process occurs in a sub-femtosecond timescale, and may provide the necessary "pump" step in a pump-probe experiment[2]. Here we used a few cycle infrared \lambda_{0}~1800nm source[3] and observed direct evidences for inner-shell excitations through the laser-induced electron recollision process. It is the first step toward time-resolved core-hole studies in the keV energy range with sub-femtosecond time resolution.Comment: 6 pages, 4 figure

Effect of Emulsifier and Co-emulsifier Combination on Oxidation Stability of Flaxseed Oil Nanoemulsion

The purpose of this study was to investigate the effects of sodium starch octenyl succinate (SSOS) as emulsifier and soy protein isolate (SPI) as co-emulsifier on the oxidative stability of nanoemulsion. The ultrasonic emulsification method was used to prepare flaxseed oil nanoemulsion. The results showed that the optimum preparation conditions were as follows: ultrasonic power of 600 W, core-to-wall ratio of 1:1.5, pulse mode of 8 s, and ultrasonication time of 20 min. The nanoemulsion obtained under these conditions was characterized by high embedding rate ((75.1 ± 4.9)% to (74.6 ± 4.2)%), low particle size ((244.0 ± 3.0) to (246.8 ± 4.5) nm) and high absolute zeta-potential value ((−67.2 ± 3.0) to (−69.3 ± 4.0) mV). With the addition of SPI, the peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) value of the nanoemulsion were significantly reduced, and the oxidative stability was remarkably improved. This could result from the fact that SPI could increase the hydrophobicity of the mixed emulsifier, preventing flaxseed oil from contacting with oxygen radicals in the aqueous phase. This study will provide a new idea for improving the water solubility and oxidative stability of flaxseed oil, and provide a theoretical basis for extending the shelf life of flaxseed oil and promoting its application in the food field

A novel MIPgene mutation associated with autosomal dominant congenital cataracts in a Chinese family

BACKGROUND: The major intrinsic protein gene (MIP), also known as MIP26 or AQP0, is a member of the water-transporting aquaporin family, which plays a critical role in the maintenance of lifelong lens transparency. To date, several mutations in MIP (OMIM 154050) have been linked to hereditary cataracts in humans. However, more pathogenic mutations remain to be identified. In this study, we describe a four-generation Chinese family with a nonsense mutation in MIP associated with an autosomal dominant congenital cataract (ADCC), thus expanding the mutational spectrum of this gene. METHODS: A large four-generation Chinese family affected with typical Y-suture cataracts combined with punctuate cortical opacities and 100 ethnically matched controls were recruited. Genomic DNA was extracted from peripheral blood leukocytes to analyze congenital cataract-related candidate genes. Effects of the sequence change on the structure and function of proteins were predicted by bioinformatics analysis. RESULTS: Direct sequencing of MIP in all affected members revealed a heterozygous nucleotide exchange c.337C>T predicting an arginine to a stop codon exchange (p.R113X). The substitution co-segregated well in all the affected individuals in the family and was not found in unaffected members or in the 100 unrelated healthy controls. Bioinformatics analysis predicted that the mutation affects the secondary structure and function of the MIP protein. CONCLUSIONS: We identified a novel mutation of MIP (p.R113X) in a Chinese cataract family. This is the first nonsense mutation of MIP identified thus far. This novel mutation is also the first disease-causing mutation located in the loop C domain of MIP. The results add to the list of mutations of the MIP linked to cataracts

Virulence of H5N1 virus in mice attenuates after in vitro serial passages

The virulence of A/Vietnam/1194/2004 (VN1194) in mice attenuated after serial passages in MDCK cells and chicken embryos, because the enriched large-plaque variants of the virus had significantly reduced virulence. In contrast, the small-plaque variants of the virus and the variants isolated from the brain of mice that were infected with the parental virus VN1194 had much higher virulence in mice. The virulence attenuation of serially propagated virus may be caused by the reduced neurotropism in mice. Our whole genome sequence analysis revealed substitutions of a total of two amino acids in PB1, three in PB2, two in PA common for virulence attenuated variants, all or part of which may be correlated with the virulence attenuation and reduced neurotropism of the serially propagated VN1194 in mice. Our study indicates that serial passages of VN1194 in vitro lead to adaptation and selection of variants that have markedly decreased virulence and neurotropism, which emphasizes the importance of direct analysis of original or less propagated virus samples

Development of an ELISA-array for simultaneous detection of five encephalitis viruses

Japanese encephalitis virus(JEV), tick-borne encephalitis virus(TBEV), and eastern equine encephalitis virus (EEEV) can cause symptoms of encephalitis. Establishment of accurate and easy methods by which to detect these viruses is essential for the prevention and treatment of associated infectious diseases. Currently, there are still no multiple antigen detection methods available clinically. An ELISA-array, which detects multiple antigens, is easy to handle, and inexpensive, has enormous potential in pathogen detection. An ELISA-array method for the simultaneous detection of five encephalitis viruses was developed in this study. Seven monoclonal antibodies against five encephalitis-associated viruses were prepared and used for development of the ELISA-array. The ELISA-array assay is based on a "sandwich" ELISA format and consists of viral antibodies printed directly on 96-well microtiter plates, allowing for direct detection of 5 viruses. The developed ELISA-array proved to have similar specificity and higher sensitivity compared with the conventional ELISAs. This method was validated by different viral cultures and three chicken eggs inoculated with infected patient serum. The results demonstrated that the developed ELISA-array is sensitive and easy to use, which would have potential for clinical use

A duplex real-time reverse transcriptase polymerase chain reaction assay for detecting western equine and eastern equine encephalitis viruses

In order to establish an accurate, ready-to-use assay for simultaneous detection of Eastern equine encephalitis virus (EEEV) and Western equine encephalitis virus (WEEV), we developed one duplex TaqMan real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay, which can be used in human and vector surveillance. First, we selected the primers and FAM-labeled TaqMan-probe specific for WEEV from the consensus sequence of NSP3 and the primers and HEX-labeled TaqMan-probe specific for EEEV from the consensus sequence of E3, respectively. Then we constructed and optimized the duplex real-time RT-PCR assay by adjusting the concentrations of primers and probes. Using a series of dilutions of transcripts containing target genes as template, we showed that the sensitivity of the assay reached 1 copy/reaction for EEEV and WEEV, and the performance was linear within the range of at least 10(6 )transcript copies. Moreover, we evaluated the specificity of the duplex system using other encephalitis virus RNA as template, and found no cross-reactivity. Compared with virus isolation, the gold standard, the duplex real time RT-PCR assay we developed was 10-fold more sensitive for both WEEV and EEEV detection

A longitudinal study on new onset anxiety among children and adolescents during the COVID-19 epidemic

Objective·To investigate the occurrence of new onset anxiety symptoms in children and adolescents during the COVID-19 epidemic, and analyze the influencing factors.Methods·Based on Chengdu Positive Child Development (CPCD) cohort, a total of 5 566 children and adolescents from five primary and secondary schools in Chengdu were enrolled. Two longitudinal study cohorts of new anxiety symptoms in children and adolescents were established, and two rounds of survey were conducted. The first round of survey (baseline survey) was conducted from December 2019 to January 2020, and the general demographic characteristics of the cohort members were collected through the Student Questionnaire for the Study on Promoting Positive Growth of Children and Adolescents. The second round of survey (follow-up survey) was conducted from February to July 2020 to collect additional information on the cohorts' infection history of COVID-19, and whether their eating, learning, and social and recreational activities were affected by the COVID-19 epidemic. The Screen for Child Anxiety Related Emotional Disorders (SCARED) was used to evaluate the new onset anxiety symptoms of all subjects. The multivariate Logistic regression model was used to analyze the influencing factors of new onset anxiety symptoms in children and adolescents.Results·The results of SCARED assessment showed that the incidence of new onset anxiety symptoms among children and adolescents in Chengdu during the COVID-19 epidemic was 13.47%. In the longitudinal study cohort of new onset anxiety in children,the incidence was 11.91%, and in the longitudinal study cohort of new onset anxiety in adolescents, the incidence was 14.25%. The results of chi square test showed that there were statistically significant differences in the incidence of new onset anxiety symptoms among children in terms of age, whether they or their family members were infected with COVID-19, and whether their eating, learning and social activities were affected (all P<0.05); there were also statistically significant differences in the incidence of new onset anxiety symptoms among adolescents in gender, grade, age, residential area, and whether their eating, learning, and social and recreational activities were affected (all P<0.05). The results of multivariate Logistic regression analysis showed that, for children, 6‒8 years old was the protective factor for their new onset anxiety symptoms, while they or their family members infected with COVID-19 and the impact of their learning activities were the risk factors (all P<0.05); for adolescents, males, residing in urban areas, and grades ≤ 6 were the protective factors for their new onset anxiety symptoms, while the impact of their learning activities was the risk factor (all P<0.05).Conclusion·For children and adolescents, the factors that affect their new onset anxiety symptoms during the COVID-19 epidemic are not completely the same. For children, age, whether they or their family members are infected with COVID-19, and whether their learning is affected are independent influencing factors; but for adolescents, gender, grade, residential area, and whether their learning is affected are independent influencing factors. Therefore, in the process of dynamically paying attention to the mental health status of children and adolescents and continuously doing a good job of mental health intervention, it is necessary to follow the law of growth, fully consider the developmental characteristics of children and adolescents, and adopt different strategies and measures

Microbiome Structure and Mucosal Morphology of Jejunum Appendix and Colon of Rats in Health and Dysbiosis

Gut microbiota contributes to human health. Plenty of studies demonstrate that antibiotics can disrupt gut ecosystem leading to dysbiosis. Little is known about the microbial variation of appendix and its up/downstream intestine after antibiotic treatment. This study aimed to investigate the microbiome and mucosal morphology of jejunum, appendix, and colon of rats in health and dysbiosis. A rodent model of antibiotic-induced dysbiosis was employed. Microscopy was used to observe mucosal morphological changes. 16S rRNA sequencing was performed for identifying bacterial taxa and microbiome structure. The appendices of dysbiosis were found enlarged and infated with loose contents. Microscopy revealed the impairment of intestinal epithelial cells. High-throughput sequencing showed the Operational Taxonomic Units changed from 361±33, 634±18, 639±19 in the normal jejunum, appendix, colon to 748±98, 230±11, 253±16 in the disordered segments, respectively. In dysbiosis, Bacteroidetes translocated inversely from the colon and appendix (0.26%, 0.23%) to the jejunum (13.87%±0.11%); the relative abundance of all intestinal Enterococcaceae increased, while Lactobacillaceae decreased. Several bacterial clusters were found correlated to the normal appendix, whereas nonspecifc clusters correlated to the disordered appendix. In conclusion, species richness and evenness reduced in the disordered appendix and colon; similar microbiome patterns were shared between the appendix and colon regardless of dysbiosis; site-specifc bacteria were missing in the disordered appendix. Appendix is likely a transit region involving in upper and lower intestinal microfora modulation. The limitation of this study is all the data were derived from rats. We must be cautious about translating the microbiome results from rats to humans

The longitudinal association between internet addiction and depressive and anxiety symptoms among Chinese adolescents before and during the COVID-19 pandemic

BackgroundThe COVID-19 pandemic and related prevention policies, such as home quarantine or online courses, could increase the risks of experiencing internet addiction and mental health problems among Chinese adolescents. There is a lack of longitudinal evidence to show the association between internet addiction symptoms and psychological consequences (e.g., depressive and anxiety symptoms).ObjectiveThis study aimed to explore the association between internet addiction and depressive and anxiety symptoms before and during the coronavirus disease 2019 (COVID-19) pandemic.MethodsAn effective sample of 7,958 Chinese adolescents was recruited for this two-wave longitudinal survey conducted over a six-month interval. All participants completed two-wave surveys before and during the COVID-19 pandemic. A longitudinal cross-lagged path model was used to analyze the associations between internet addiction and depressive and anxiety symptoms after controlling for four covariates (i.e., age, sex, minority, and COVID-19 influence).ResultsHigher depressive and anxiety symptoms before COVID-19 significantly predicted severe internet addiction during COVID-19. Results showed a significant bidirectional relationship between internet addiction and depressive symptoms. Furthermore, the prevalence of internet addiction displayed an increasing trend over the two waves. Conversely, a reduced prevalence of anxiety and depressive symptoms was observed over the two waves.ConclusionThis current study provided valuable evidence that psychological problems and internet addiction significantly influenced each other before and during the COVID-19 outbreak. Consequently, the presence of psychological problems before and during the COVID-19 outbreak could indicate internet addiction. Thus, depression- and anxiety-related psychotherapies should be developed to prevent internet addiction among Chinese adolescents

Laser-Activatable CuS Nanodots to Treat Multidrug-Resistant Bacteria and Release Copper Ion to Accelerate Healing of Infected Chronic Nonhealing Wounds

Chronic nonhealing wounds have imposed serious challenges in the clinical practice, especially for the patients infected with multidrug-resistant microbes. Herein, we developed an ultrasmall copper sulfide (covellite) nanodots (CuS NDs) based dual functional nanosystem to cure multidrug-resistant bacteria-infected chronic nonhealing wound. The nanosystem could eradicate multidrug-resistant bacteria and expedite wound healing simultaneously owing to the photothermal effect and remote control of copper-ion release. The antibacterial results indicated that the combination treatment of photothermal CuS NDs with photothermal effect initiated a strong antibacterial effect for drug-resistant pathogens including methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase Escherichia coli both in vitro and in vivo. Meanwhile, the released Cu2+ could promote fibroblast cell migration and endothelial cell angiogenesis, thus accelerating wound-healing effects. In MRSA-infected diabetic mice model, the nanosystem exhibited synergistic wound healing effect of infectious wounds in vivo and demonstrated negligible toxicity and nonspecific damage to major organs. The combination of ultrasmall CuS NDs with photothermal therapy displayed enhanced therapeutic efficacy for chronic nonhealing wound in multidrug-resistant bacterial infections, which may represent a promising class of antibacterial strategy for clinical translation.Peer reviewe