Realizing N-type SnTe Thermoelectrics with Competitive Performance through Suppressing Sn Vacancies.

Due to the intrinsically plentiful Sn vacancies, developing n-type SnTe thermoelectric materials is a big challenge. Herein, n-type SnTe thermoelectric materials with remarkable performance were successfully synthesized through suppressing Sn vacancies, followed by electron-doping. Pb alloying notably depressed the Sn vacancies via populating Sn vacancies in SnTe (supported by transmission electron microscopy), and the electrical transports were shifted from p-type to n-type through introducing electrons using I doping. In the n-type SnTe, we found that the electrical conductivity could be enhanced by increased carrier mobility through sharpening conduction bands after alloying Pb, while the lattice thermal conductivity could be reduced via strong phonon scattering after introducing defects by Pb alloying and I doping. Resulting from these enhancements, the n-type Sn0.6Pb0.4Te0.98I0.02 achieves a notably high ZTmax ∼ 0.8 at 573 K and a remarkable ZTave ∼ 0.51 at 300-823 K, which can match many excellent p-type SnTe. This work indicates that n-type SnTe could be experimentally acquired and is a promising candidate for thermoelectric generation, which will stimulate further research on n-type SnTe thermoelectric materials and even devices on the basis of both n- and p-type SnTe legs.

Lychee-like TiO2@TiN dual-function composite material for lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are promising candidates for next generation rechargeable batteries because of their high energy density of 2600 W h kg-1. However, the insulating nature of sulfur and Li2S, the "shuttle effect" of lithium polysulfides (LiPSs), and the volumetric change of sulfur electrodes limit the practical application of Li-S batteries. Here, lychee-like TiO2@TiN hollow spheres (LTTHS) have been developed that combine the advantages of high adsorption TiO2 and high conductivity TiN to achieve smooth adsorption/spread/conversion of LiPSs and use them as a sulfur host material in Li-S batteries for the first time. The cathode exhibits an initial specific capacity of 1254 mA h g-1 and a reversible capacity of 533 mA h g-1 after 500 cycles at 0.2C, which corresponds to an average coulombic efficiency up to 99%. The cell with the LTTHS@S cathode achieved an extended lifespan of over 1000 cycles. Such good performance can be assigned to the good adsorption and catalysis of the dual-function TiO2@TiN composite. This work proved that the TiO2@TiN composite can be an attractive matrix for sulfur cathodes.

A population pharmacokinetic model of vancomycin for dose individualization based on serum cystatin C as a marker of renal function.

OBJECTIVES: This study aimed to establish a vancomycin population pharmacokinetics (PPK) model based on serum cystatin C and to optimize dosing for achieving targeted steady-state trough concentrations (Css ) of 10-15 and 15-20 mg/l. METHODS: Patients aged ≥18 years were prospectively enrolled. A vancomycin PPK model was built with glomerular filtration rate (GFR) as a renal covariate estimated by cystatin C. A new group of patients were used for external evaluation. PPK analysis and Monte Carlo simulations were performed using nonlinear mixed effect modelling programme. KEY FINDINGS: Two hundreds of patients with 514 samples were included. The final model was CL (L/h) = (5.07 × (GFR/105.5)0.524 × (AGE/48.5)-0.309 × (WT/60)0.491 ); V (l) = 46.3. Internal and external evaluations demonstrated good stability and predictability. The average probability of target attainment (PTA) of optimal dosing regimens for targeted Css achieving 10-15 and 15-20 mg/l were 51.2% and 40.6%, respectively. An average PTA ≥71% for targeted concentration of 10-20 mg/l was obtained. CONCLUSIONS: A vancomycin PPK model with cystatin C as the renal marker has good stability and predictability. The new proposed dosing regimens were predicted to achieve a good PTA.

Identification of Risk Factors in High-Dose Methotrexate-Induced Acute Kidney Injury in Childhood Acute Lymphoblastic Leukemia.

AIMS: Although high-dose methotrexate (HDMTX) is an effective means for the treatment of acute lymphoblastic leukemia (ALL), the development of renal dysfunction remains a significant management challenge. This study aimed to identify the key factors in HDMTX-induced acute kidney injury (AKI) in childhood ALL. METHODS: We retrospectively analyzed the clinical data in 1,329 courses of HDMTX treatment in 336 Chinese ALL children at the First Affiliated Hospital of Guangxi Medical University from September 2012 to November 2016. The clinical data were compared between the groups of children with development of AKI and those without. Risk factors were identified by multiple logistic regression analysis, and the diagnostic performance of plasma MTX concentration was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: AKI was observed in 88 patients (26.2%) and 104 courses (7.8%). Binary logistic regression revealed that age (OR 1.349; p = 0.005), first HDMTX course (OR 1.767; p = 0.013), MTX dose per body surface area (BSA; OR 1.944; p = 0.015), and baseline serum total protein (OR 0.929; p = 0.021) significantly correlated with AKI. The area under the ROC for 48-h plasma MTX concentration was 0.890 (95% CI 0.850-0.930), and sensitivity and specificity values of the cut-off value were 78.8 and 90.4%, respectively. CONCLUSION: Increasing age, higher MTX dose per BSA, lower baseline serum protein, and first HDMTX course were significant risk factors for developing HDMTX-induced AKI in childhood ALL. The threshold of 48-h MTX plasma concentration is valuable for the prediction of HDMTX-induced AKI.