A highly efficient and recyclable living biocatalyst using Shewanella@polydopamine@NH2-doped carbon dot biohybrids and polypyrrole immobilized melamine foam for microbial-photoreduction of Cr(VI)

A novel living biocomposite was engineered to boost environmental Cr(VI) remediation. Photosensitive biohybrids were firstly configured through an inward-to-outward assembly of NH2-doped carbon dots (NCDs), polydopamine (PDA) and wild Shewanella oneidensis MR-1 cells to generate microbial-photoreduction of Cr(VI) at the nanoscale. Then, biohybrid-derived biofilms were implanted onto the surface of melamine foam (MF) through an in-situ polypyrrole (PPy)-heterojunction to form highly conductive living MF/PPy/biohybrid biocomposites at a macroscale. Bacterial biomass immobilized onto the surface of MF and the efficacy of related biocomposites for Cr(VI) reduction increased with increasing pyrrole (PY) monomer concentrations (0.15 → 0.60 mL). In a 50 mg/L-Cr(VI) reduction system conducted under visible light illumination, biocomposites treated with 0.60 mL PY monomer displayed the highest Cr(VI) reduction efficiency (100%) with the shortest reaction time (24 h) during the first reduction cycle and significantly outperformed other biocomposite formulations over longer time periods (36–72 h). The living biocomposites exhibited an outstanding recyclability (>4 cycles) in subsequent reduction cycles. Overall, a reliable amalgamation of all living/non-living components integrated into the biocomposite ensured an efficient biocatalyst framework for Cr(VI) reduction and recyclable use

Validating HY-2A CMR precipitable water vapor using ground-based and shipborne GNSS observations

The calibration microwave radiometer (CMR) on board the Haiyang-2A (HY-2A) satellite provides wet tropospheric delay correction for altimetry data, which can also contribute to the understanding of climate system and weather processes. The ground-based global navigation satellite system (GNSS) provides precise precipitable water vapor (PWV) with high temporal resolution and could be used for calibration and monitoring of the CMR data, and shipborne GNSS provides accurate PWV over open oceans, which can be directly compared with uncontaminated CMR data. In this study, the HY-2A CMR water vapor product is validated using ground-based GNSS observations of 100 International GNSS Service (IGS) stations along the global coastline and 56 d shipborne GNSS observations over the Indian Ocean. The processing strategy for GNSS data and CMR data is discussed in detail. Special efforts were made in the quality control and reconstruction of contaminated CMR data. The validation result shows that HY-2A CMR PWV agrees well with ground-based GNSS PWV with 2.67 mm as the root mean square (rms) within 100 km. Geographically, the rms is 1.12 mm in the polar region and 2.78 mm elsewhere. The PWV agreement between HY-2A and shipborne GNSS shows a significant correlation with the distance between the ship and the satellite footprint, with an rms of 1.57 mm for the distance threshold of 100 km. Ground-based GNSS and shipborne GNSS agree with HY-2A CMR well

Crystal growth, structure and thermal properties of noncentrosymmetric single crystals PrCa4O(BO3)3

Noncentrosymmetric praseodymium calcium oxyborate single crystals, PrCa4O(BO3)3 (PrCOB), were grown by the Czochralski technique. The monoclinic unit cell parameters were found to be a = 8.177 Å, b = 16.157 Å, c = 3.629 Å and Z = 2 with space group Cm. Crystal density was measured using the Archimedes method, being on the order of 3.47 g cm-3. Thermal properties of PrCOB were investigated, where the specific heat was found to be 0.63 J g-1 °C-1 at room temperature, increasing to 0.85 J g-1°C-1 at 700°C. The thermal expansion coefficients were measured to be α11 = 7.99, α22 = 4.90 and α33 = 9.46 (10-6/°C), respectively. In addition, thermal diffusivity λ22 and thermal conductivity κ22 as a function of temperature were studied, where λ22 was observed to decrease from 0.89 to 0.58 mm2 s-1, while κ22 was found to maintain the same value, being ∼1.90 W m-1°C-1 over the temperature range of 20-700°C. 2013 The Royal Society of Chemistry

Draft genome sequence of the Tibetan antelope

The Tibetan antelope (Pantholops hodgsonii) is endemic to the extremely inhospitable high-altitude environment of the Qinghai-Tibetan Plateau, a region that has a low partial pressure of oxygen and high ultraviolet radiation. Here we generate a draft genome of this artiodactyl and use it to detect the potential genetic bases of highland adaptation. Compared with other plain-dwelling mammals, the genome of the Tibetan antelope shows signals of adaptive evolution and gene-family expansion in genes associated with energy metabolism and oxygen transmission. Both the highland American pika, and the Tibetan antelope have signals of positive selection for genes involved in DNA repair and the production of ATPase. Genes associated with hypoxia seem to have experienced convergent evolution. Thus, our study suggests that common genetic mechanisms might have been utilized to enable high-altitude adaptation