Harmonic Suppression Induced by Three-Electron Dynamics of Li in Strong Laser Fields.

We build a model to elucidate the high harmonic generation in combined EUV and midinfrared laser fields by embodying the spin-resolved three-electron dynamics. The EUV pulse ionizes an inner-shell electron, and the midinfrared laser drives the photoelectron and steers the electron-ion rescattering. Depending on the spin of the photoelectron, the residual ion including two bound electrons can be either in a single spin configuration or in a coherent superposition of different spin configurations. In the latter case, the two electrons in the ion swap their orbits, leading to a deep valley in the harmonic spectrum. The model results agree with the time-dependent Schrödinger equation simulations including three active electrons. The intriguing picture explored in this work is fundamentally distinguished from all reported scenarios relied on spin-orbit coupling, but originates from the exchanges asymmetry of two-electron wave functions.

Development of bacterial cellulose/chitin multi-nanofibers based smart films containing natural active microspheres and nanoparticles formed in situ.

Nanofiber-based materials have recently gained increasing attention in food packaging, drug delivery, and biomedical applications. In this study, a multi-nanofibers composite film was developed based on bacterial cellulose nanofiber (BCNF)/chitin nanofiber (CNF) hybridization. The nanofibers were responsible for the formation of well-dispersed curcumin (Cur) micro/nanoparticles in the nanocomposite films. The release of Cur from the films were affected by CNF and the sizes of Cur particles formed in situ. The Cur particles reduced tensile strength and increased water vapor permeability of BCNF film. However, CNF improved the mechanical strength and barrier property of the Cur/BCNF/CNF composite film. Moreover, the multi-nanofibers composite film showed excellent dynamic antioxidant capacity and antibacterial activity, as well as was capable to monitor pH change and trace amount of boric acid. Results of this study suggested that the Cur/BCNF/CNF composite film can be used as a smart and active food packaging material.

Outcomes of the national programme on prevention of mother-to-child transmission of hepatitis B virus in China, 2016-2017.

BACKGROUND: In addition to providing free hepatitis B vaccine (HBvacc) series to all infants in China since 2005, the national programme on prevention of mother-to-child transmission (PMTCT) of hepatitis B virus (HBV) started providing free hepatitis B immunoglobulin for all new-borns born to hepatitis B surface-antigen (HBsAg) positive mothers in 2010. However, few studies have evaluated the effectiveness of the PMTCT programme. Therefore, we aimed to investigate the outcomes of the programme and identify associated factors. METHOD: Using a cross-sectional study design, we collected data on 4112 pairs of HBsAg-positive mothers and their children aged 7-22 months in four representative provinces through interviews and medical record review. We tested HBsAg and hepatitis B surface antibody (anti-HBs) of children by enzyme-linked immunosorbent assay at designated maternal and child hospital laboratories. We used logistic regression to analyse factors associated with child HBsAg and anti-HBs positivity. RESULTS: Thirty-five children were HBsAg positive, indicating the mother-to-child transmission (MTCT) rate was 0.9% (0.6-1.1%). The anti-HBs positive rate was 96.8% (96.3-97.4%). Children receiving HBvacc between 12 and 24 h of birth were 2.9 times more likely to be infected than those vaccinated in less than 12 h (adjusted odds ratio [aOR] = 2.9, 95% confidence interval [CI]: 1.4-6.3, P = 0.01). Maternal hepatitis B e-antigen (HBeAg) positivity was associated with higher MTCT rate (aOR = 79.1, 95% CI: 10.8-580.2, P <  0.001) and lower anti-HBs positive rate (aOR = 0.4, 95% CI: 0.3-0.6, P <  0.001). Children with low birth weight (LBW) were 60% less likely to be anti-HBs positive than those with normal birth weight (aOR = 0.4, 95% CI: 0.2-0.8, P = 0.01). CONCLUSIONS: The MTCT rate was lower than the 2030 WHO elimination goal, which implies the programme is on track to achieve this target. As earlier HBvacc birth dose (HBvcc-BD) was associated with lower MTCT rate, we suggest that the PMTCT programme work with the Expanded Programme on Immunization (EPI) to modify the current recommendation for early HBvcc-BD to a requirement. Our finding that LBW was associated with lower anti-HBs positivity points to the need for further studies to understand factors associated with these risks and opportunities for program strengthening. The programme needs to ensure providing essential test to identify HBeAg-positive mothers and their infants and provide them with appropriate medical care and follow-up.

[An analysis of antiretroviral therapy outcomes in the Medecins Sans Frontieres/Guangxi Center for Disease Control and Prevention HIV/AIDS project].

OBJECTIVE: To evaluate the 3-year outcomes of the Medecins Sans Frontieres/Guangxi Center for Disease Control and Prevention comprehensive and free of charge HIV/AIDS treatment and care project. METHODS: We present a detailed retrospective analysis of treatment outcomes of 432 cases who received highly active antiretroviral therapy (HAART) from December 2003 to December 2006. RESULTS: Among the adult patients who received HAART, the mortality rate was 6.5% and only 12 (2.8%) patients were lost to follow up. The mean CD4+ T cell count increase was 147 cells/microl and 246 cells/microl for patients receiving HAART for 9-15 and 21-27 months respectively. An adherence assessment conducted during March to December 2006 indicated that 95.9% of the study cases reached an adherence of 95% or more of the prescribed medications. Among the 30 children patients who received HAART, 4 (13.3%) cases died and the mean CD4+ T cell increase after 9-15 and 21-27 months of HAART was 673 cells/microl and 658 cells/microl respectively. 148 of the adult patients starting HAART were current or ex-intravenous drug users (IDU) and showed global death rate and lost to follow-up rate comparable to those of non-IDU patients (Log rank test, P = 0.91). CONCLUSIONS: Good mid-term therapeutic outcomes with combination antiretroviral therapy have been achieved in this project. Total free of charge care and treatment and intensive patient support/ counseling are crucial to program success.

Drug release and antioxidant/antibacterial activities of silymarin-zein nanoparticle/bacterial cellulose nanofiber composite films.

Bacterial cellulose (BC) is a biopolymer composed of nanofibers which has excellent film-forming ability. However, BC do not have antibacterial or antioxidant activity, thus limiting the applicability of BC for food and biomedical applications. In this study, flavonoid silymarin (SMN) and zein were assembled into spherical SMN-Zein nanoparticles that could be effectively adsorbed onto BC nanofibers. SMN-Zein nanoparticles greatly changed the wettability and swelling property of BC films due to the formation of nanoparticles/nanofibers nanocomposites. SMN-Zein nanoparticles enhanced the release of sparingly soluble silymarin from the nanocomposite films. The active films showed more effective antioxidant and antibacterial activities as compared with pure BC films and thus were able to protect salmon muscle from deterioration and lipid oxidation. These findings suggest that the nanoparticle/nanofiber composites may offer a suitable platform for modification of BC films with improved drug release properties and biological activities.