N-Containing Carbon-Coated ß-Si3 N4 Enhances Si Anodes for High-Performance Li-Ion Batteries.

The lithiation/delithiation properties of α-Si3 N4 and ß-Si3 N4 are compared and the carbon coating effects are examined. Then, ß-Si3 N4 at various fractions is used as the secondary phase in a Si anode to modify the electrode properties. The incorporated ß-Si3 N4 decreases the crystal size of Si and introduces a new NSiO species at the ß-Si3 N4 /Si interface. The nitrogen from the milled ß-Si3 N4 diffuses into the surface carbon coating during the carbonization heat treatment, forming pyrrolic nitrogen and CNO species. The synergistic effects of combining ß-Si3 N4 and Si phases on the specific capacity are confirmed. The operando X-ray diffraction and X-ray photoelectron spectroscopy data indicate that ß-Si3 N4 is partially consumed during lithiation to form a favorable Li3 N species at the electrode. However, the crystalline structure of the hexagonal ß-Si3 N4 is preserved after prolonged cycling, which prevents electrode agglomeration and performance deterioration. The carbon-coated ß-Si3 N4 /Si composite anode shows specific capacities of 1068 and 480 mAh g-1 at 0.2 and 5 A g-1 , respectively. A full cell consisting of the carbon-coated ß-Si3 N4 /Si anode and a LiNi0.8 Co0.1 Mn0.1 O2 cathode is constructed and its properties are evaluated. The potential of the proposed composite anodes for Li-ion battery applications is demonstrated.

Building HIV healthcare worker capacity through telehealth in Vietnam.

Development of a robust technical assistance system is an essential component of a sustainable HIV response. Vietnam's National HIV Program is transitioning from a largely donor-funded programme to one primarily supported by domestic resources. Telehealth interventions are increasingly being used for training, mentoring and expert consultation in high-resource settings and hold significant potential for use as a tool to build HIV health worker capacity in low and middle-income countries. We designed, implemented and scaled up a novel HIV telehealth programme for Vietnam, with the goal of building a sustainable training model to support the country's HIV workforce needs. Over a 4-year period, HIV telehealth programmes were initiated in 17 public institutions with participation of nearly 700 clinical sites across 62 of the 63 provinces in the country. The telehealth programme was used to deliver certificate training courses, provide clinical mentoring and case-based learning, support programme implementation, provide coaching in quality improvement and disseminate new guidelines and policies. Programme evaluation demonstrated improved health worker self-reported competence in HIV care and treatment and high satisfaction among the programme participants. Lessons learnt from Vietnam's experience with telehealth can inform country programmes looking to develop a sustainable approach to HIV technical assistance and health worker capacity building.

Response to hepatitis B vaccination among HIV-infected adults in Vietnam.

OBJECTIVES: We sought to determine the rate of response to hepatitis B (HBV) vaccination among HIV-infected adults in Vietnam. METHODS: We retrospectively abstracted data from a cohort of HIV-infected adults who had received HBV vaccine at an HIV clinic in Hanoi. We examined demographic, clinical and laboratory factors for associations with development of a protective antibody (Ab) response following vaccination (defined as 'responders' with anti-HBs >10 IU/L). RESULTS: Out of 302 HIV-infected patients who completed the vaccine series and follow-up serology testing, 189 (62.6%) had a positive protective Ab response. Female patients had a higher response rate compared to male patients (71.4% vs 56.8%, P=0.01). Among responders, mean CD4 T cell count was 309 cells/µL as compared to 204 cells/µL in non-responders (P<0.0001). On multivariable analysis, CD4 T cell count prior to vaccination was the only factor independently associated with a positive Ab response. Compared to patients with a count less than 100 cells/µL, those with a CD4 T cell count between 100 and 200 cells/µL were 20% more likely to be responders (relative risk [RR] 1.20, 95% confidence interval [CI] 0.77-1.87), those with a CD4 T cell count between 200 and 300 cells/µL were 61% more likely to be responders (RR 1.61, 95% CI 1.05-2.45), and those with a CD4 T cell count greater than 300 cells/µL were 89% more likely to be responders (RR 1.89, 95% CI 1.26-2.83). CONCLUSIONS: We found that the CD4 T cell count at the time of vaccination to be the sole predictor of response to HBV vaccination among HIV-infected Vietnamese adults. Our findings highlight the importance of vaccinating HIV-infected adults prior to advanced immunosuppression.