Ball milling synthesis of Fe3O4 nanoparticles-functionalized porous boron nitride with enhanced cationic dye removal performance.

Enhancement of the adsorption performance and recyclability of adsorbents is a crucial aspect of water treatment. Herein, we used one-dimensional porous boron nitride (PBN) as a carrier to load Fe3O4 nanoparticles for the preparation of Fe3O4 nanoparticles-functionalized porous boron nitride (Fe3O4/PBN) via a ball milling method. The high-energy ball milling promoted the creation of a negatively charged PBN surface and facilitated the uniform distribution of Fe3O4 nanoparticles on the surface of PBN. The adsorption performance of Fe3O4/PBN toward cationic dyes could be significantly improved while no enhancement was observed for anionic dyes. The great adsorption performance of Fe3O4/PBN is due to its surface functional groups and surface defects formed in the ball milling process. Moreover, the strong interaction force between Fe3O4/PBN and cationic dyes promotes rapid initial adsorption due to their negatively charged surface. Magnetic measurements demonstrated that Fe3O4/PBN is superparamagnetic. The composites with low loadings of Fe3O4 nanoparticles could be quickly separated from the aqueous solution under a low applied magnetic field, improving their recyclability. This work highlights the role of ball milling in improving the adsorption performance of Fe3O4/PBN and greatly promotes the practical application of Fe3O4/PBN in the field of environmental purification.

Immune persistence after different polio sequential immunization schedules in Chinese infants.

Trivalent oral poliovirus vaccine (tOPV) has been withdrawn and instead an inactivated poliovirus vaccine (IPV) and bivalent type 1 and type 3 OPV (bOPV) sequential immunization schedule has been implemented since 2016, but no immune persistence data are available for this polio vaccination strategy. This study aimed to assess immune persistence following different polio sequential immunization schedules. Venous blood was collected at 24, 36, and 48 months of age from participants who had completed sequential schedules of combined IPV and OPV in phase III clinical trials. The serum neutralizing antibody titers against poliovirus were determined, and the poliovirus-specific antibody-positive rates were evaluated. A total of 1104 participants were enrolled in this study. The positive rates of poliovirus type 1- and type 3-specific antibodies among the sequential immunization groups showed no significant difference at 24, 36, or 48 months of age. The positive rates of poliovirus type 2-specific antibody in the IPV-IPV-tOPV group at all time points were nearly 100%, which was significantly higher than the corresponding rates in other immunization groups (IPV-bOPV-bOPV and IPV-IPV-bOPV). Immunization schedules involving one or two doses of IPV followed by bOPV failed to maintain a high positive rate for poliovirus type 2-specific antibody.

Interface contact and modulated electronic properties by in-plain strains in a graphene-MoS2 heterostructure.

Designing a specific heterojunction by assembling suitable two-dimensional (2D) semiconductors has shown significant potential in next-generation micro-nano electronic devices. In this paper, we study the structural and electronic properties of graphene-MoS2 (Gr-MoS2) heterostructures with in-plain biaxial strain using density functional theory. It is found that the interaction between graphene and monolayer MoS2 is characterized by a weak van der Waals interlayer coupling with the stable layer spacing of 3.39 Å and binding energy of 0.35 J m-2. In the presence of MoS2, the linear bands on the Dirac cone of graphene are slightly split. A tiny band gap about 1.2 meV opens in the Gr-MoS2 heterojunction due to the breaking of sublattice symmetry, and it could be effectively modulated by strain. Furthermore, an n-type Schottky contact is formed at the Gr-MoS2 interface with a Schottky barrier height of 0.33 eV, which can be effectively modulated by in-plane strain. Especially, an n-type ohmic contact is obtained when 6% tensile strain is imposed. The appearance of the non-zero band gap in graphene has opened up new possibilities for its application and the ohmic contact predicts the Gr-MoS2 van der Waals heterojunction nanocomposite as a competitive candidate in next-generation optoelectronics and Schottky devices.

Excimer Laser-Deposited Na2/3Ni1/4Mn3/4O2 Film Cathode for Stable Sodium-Ion Battery.

Continued development of lithium-ion batteries is limited by the shortage of Li element. In this situation, the exploration of high-performance sodium-ion batteries is attracting much attention. In this experimental work, Na2/3Ni1/4Mn34O2 film cathode materials were fabricated by excimer laser deposition at different oxygen partial pressures. X-ray diffraction studies and field emission scanning electron microscopy revealed high c-axis orientation and uniform grain distribution, respectively, in the deposited films. Furthermore, after 30 cycles under a current density of 13 mA g-1, the film samples deposited at an oxygen partial pressure of 65 Pa exhibited a high capacity-retention of 91%. The film structure also had a large-current discharge performance, which makes practical applications possible.

Template-free synthesis of three dimensional porous boron nitride nanosheets for efficient water cleaning.

Preparation of efficient and reusable adsorption materials for water treatment and purification is still remarkably challenging. In this paper, three dimensional porous boron nitride nanosheets (3D porous BNNSs) with high chemical stability and excellent adsorption capacity for organic dyes have been successfully synthesized through a template-free route. The 3D porous BNNSs consist of uniform nanosheets with average diameter of about 200 nm and thickness of about 3 nm. The adsorption conditions have been optimized by varying the experimental parameters such as initial dye concentration, solution pH, contact time, etc. As expected, the 3D porous BNNSs exhibit superior adsorption activity toward methylene blue (MB) in aqueous solution: more than 95.3% of the dye can be removed within 5 min compared with the adsorption efficiency of 10% for conventional activated carbon and 67.5% for the 3D porous BNNSs reported previously at pH 8.0 and 30 °C. The unique 3D structure and high density adsorption sites are believed to play a key role in the efficient removal performance. Moreover, about 94.5% of the starting adsorption capacity is maintained after ten adsorption-regeneration cycles. With the high adsorption efficiency and reusability performance, the 3D porous BNNSs are suitable for water cleaning and meet the requirement of mass production.

Efficacy and safety of a pentavalent live human-bovine reassortant rotavirus vaccine (RV5) in healthy Chinese infants: A randomized, double-blind, placebo-controlled trial.

BACKGROUND: A randomized, double-blind, placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a pentavalent live human-bovine reassortant rotavirus vaccine (RotaTeq™, RV5) against rotavirus gastroenteritis (RVGE). METHODS: 4040 participants aged 6-12weeks were enrolled and randomly assigned to either 3 oral doses of RV5 (n=2020) or placebo (n=2020), administered ∼4weeks apart. The participants also received OPV and DTaP in a concomitant or staggered fashion. The primary objective was to evaluate vaccine efficacy (VE) against naturally-occurring RVGE at least 14days following the third dose. Key secondary objectives included: VE against naturally-occurring severe RVGE and VE against severe and any-severity RVGE caused by rotavirus serotypes contained in the vaccine, occurring at least 14days after the third dose. All adverse events (AEs) were collected for 30days following each dose. Serious AEs (SAEs) and intussusception cases were collected during the entire study. (ClinicalTrials.gov registry: NCT02062385). RESULTS: VE against RVGE of any-severity caused by any serotype was 69.3% (95% CI: 54.5, 79.7). The secondary efficacy analysis showed an efficacy of: 78.9% (95% CI: 59.1, 90.1) against severe RVGE caused by any serotype; 69.9% (95% CI: 55.2, 80.3) and 78.9% (95% CI: 59.1, 90.1) against any-severity and severe RVGE caused by serotypes contained in the vaccine, respectively. Within 30days following any vaccination, 53.5% (1079/2015) and 53.3% (1077/2019) of participants reported at least one AE, and 5.8% (116/2015) and 5.7% (116/2019) reported SAEs in the vaccine and placebo groups, respectively. No SAEs were considered vaccine-related in recipients of RV5. Two intussusception cases were reported in recipients of RV5 who recovered after receiving treatment. Neither was considered vaccine-related. CONCLUSIONS: In Chinese infants, RV5 was efficacious against any-severity and severe RVGE caused by any serotype and generally well-tolerated with respect to AEs.

Immunogenicity and reactogenicity of the human rotavirus vaccine, RIX4414 oral suspension, when co-administered with routine childhood vaccines in Chinese infants.

This study evaluated the immunogenicity of the human rotavirus (RV) vaccine (RIX4414) when co-administered with routine childhood vaccines in Chinese infants (NCT01171963). Healthy infants aged 6-16 weeks received 2 doses of either RIX4414 or placebo according to a 0, 1-month schedule. Infants received routine diphtheria-tetanus-acellular pertussis (DTPa) and oral poliovirus (OPV) vaccines either separately from or concomitantly with RIX4414/placebo (separate and co-administration cohorts, respectively). Anti-RV IgA seroconversion rates (one month post-dose-2) and seropositivity rates (at one year of age) were measured using ELISA. Immune responses against the DTPa and OPV antigens were measured one month post-DTPa dose-3 in the co-administration cohort. Solicited local and general symptoms were recorded for 8-days post-vaccination (total cohort). The according-to-protocol immunogenicity population included 511 infants in the separate cohort and 275 in the co-administration cohort. One month post-RIX4414 dose-2, anti-RV IgA seroconversion rates were 74.7% (95% confidence interval [CI]: 68.9-79.9) and 64.2% (95% CI: 55.4-72.3) in the separate and co-administration cohorts; seropositivity rates at one year of age were 71.5% (95% CI: 65.5-77.1) and 50.0% (95% CI: 40.9-59.1), respectively. One month post-DTPa dose-3, all infants in the co-administration cohort were seroprotected against diphtheria and tetanus, and seropositive for pertussis toxoid, pertactin and filamentous haemaglutinin. Two months post-OPV dose-3, seroprotection rates against anti-poliovirus types 1, 2 and 3 were >99% in the co-administration cohort. Reactogenicity profiles were similar in both cohorts. RIX4414 was immunogenic and well-tolerated in Chinese infants and did not appear to interfere with the immunogenicity and reactogenicity of co-administered routine childhood vaccines.

Human rotavirus vaccine (RIX4414) efficacy in the first two years of life: a randomized, placebo-controlled trial in China.

Rotaviruses (RV) are a major cause of severe gastroenteritis (GE) in children aged<5 y. For the first time in China, we assessed the efficacy of two oral doses of the human rotavirus vaccine (RIX4414) in infants during the first two years of life (113808/NCT01171963). Healthy infants aged 6-16 weeks were randomized (1:1) to receive two oral doses of either the RIX4414 vaccine/placebo according to a 0, 1 month schedule. Vaccine efficacy (VE) against severe RVGE was assessed from two weeks post-Dose 2 up until the end of the second RV season and calculated with its 95% confidence intervals (CI). The primary efficacy objective was met if the lower limit of the 95% CI on VE was ≥10%. Unsolicited symptoms reported during the 31-d post-vaccination follow-up period and serious adverse events (SAEs) reported throughout the study were assessed. Of 3333 enrolled infants, 3148 were included in the according-to-protocol efficacy cohort. Over two consecutive RV seasons, fewer severe RVGE episodes were reported in the RIX4414 group (n=21) vs. the placebo group (n=75). VE against severe RVGE was 72% (95% CI: 54.1-83.6); the lower limit of the 95% CI on VE was >10%. The number of unsolicited symptoms and SAEs reported was similar between both groups. Thirteen deaths (RIX4414=6; placebo=7) occurred during the study. All SAEs and deaths in the RIX4414 group were considered unrelated to vaccination. Two oral doses of RIX4414 vaccine provided a substantial level of protection against severe RVGE in Chinese children during the first two years of life.