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Babesiosis is a malaria-like disease in humans and animals that is caused by Babesia species, which are tick-transmitted apicomplexan pathogens. Babesia duncani causes severe to lethal infection in humans, but despite the risk that this parasite poses as an emerging pathogen, little is known about its biology, metabolic requirements or pathogenesis. Unlike other apicomplexan parasites that infect red blood cells, B. duncani can be continuously cultured in vitro in human erythrocytes and can infect mice resulting in fulminant babesiosis and death. We report comprehensive, detailed molecular, genomic, transcriptomic and epigenetic analyses to gain insights into the biology of B. duncani. We completed the assembly, 3D structure and annotation of its nuclear genome, and analysed its transcriptomic and epigenetics profiles during its asexual life cycle stages in human erythrocytes. We used RNA-seq data to produce an atlas of parasite metabolism during its intraerythrocytic life cycle. Characterization of the B. duncani genome, epigenome and transcriptome identified classes of candidate virulence factors, antigens for diagnosis of active infection and several attractive drug targets. Furthermore, metabolic reconstitutions from genome annotation and in vitro efficacy studies identified antifolates, pyrimethamine and WR-99210 as potent inhibitors of B. duncani to establish a pipeline of small molecules that could be developed as effective therapies for the treatment of human babesiosis.

The ever‐increasing consumption of fossil energy highlights the urgent need to develop technologies to ensure the efficient drilling and exploration of oil and gas resources mainly distributed in deep layers. The complex geological conditions in deep formations with the feature of high temperature, high pressure, and high salinity result in high requirements for the performance of drilling fluids. Various additives are demonstrated to decide the physicochemical properties and functional characteristics of water‐based drilling fluids. As one of the most widely used additives in water‐based drilling fluids, various polymeric filtrate reducers play an important role in minimizing fluid loss, maintaining wellbore stability, ensuring drilling safety and efficiency as well as avoiding formation damage. Herein the design, preparation, and applications of polymer‐based filtrate reducers for fluid loss control in drilling operation are comprehensively summarized. The spotlight is centered on the design strategies and structure–property–performance relationships of polymeric filtrate reducers to minimize fluid loss under high temperature, high pressure, and high salinity conditions. Future perspectives for achieving excellent comprehensive performance are also discussed to motivate new strategies and technologies to design and develop high‐performance drilling fluids with optimal rheological and filtration properties. [ABSTRACT FROM AUTHOR]

Encouraged by the successful fabrication of C60‐GNR (GNR=graphene nanoribbon) single‐molecule transistors in experiments, four Fe‐containing derived double‐layered devices of Fe@C60‐GNR are designed by employing different electrode linkages and their transport properties are investigated by using density functional theory (DFT) and nonequilibrium Green's function (NEGF) methods. Regardless of electrode connection, all these devices give rise to a smaller negative differential resistance (NDR) peak at V=0.2 and a higher peak at 1.2 V, suggesting their stable maneuverability as molecular devices and good candidates for developing on(off)‐off(on)‐on(off) current switches. The macroscopic NDR performance depends on the delocalization character and the crossing mechanism of the frontier orbitals. The peak‐to‐valley current ratios (Rmax) range from 454 to 2737, determined by the electrode linkage. Such a large Rmax‐value is necessary for developing dynamic random‐access memory (DRAM) cells. Encapsulating the Fe atom inside C60 not only improves the conductivity but also introduces the spin‐polarized transport property. The spin‐filtering efficiency (SFE) of almost all devices oscillates up and down in response to the bias voltage, indicating the possibility of designing on(off)‐off(on)‐on(off) spin switches and up‐down spin switches. All these fascinating properties provide an important clue for designing similar molecular devices with multiple functions by trapping magnetic transition metal atoms inside fullerenes. [ABSTRACT FROM AUTHOR]

Encouraged by the promising performance of C60-graphene single-molecule transistors observed in experiments, two types of Fen/C60-GNR (n = 2 and 4 and GNR = graphene nanoribbon) molecules with Fe atoms sandwiched between the upper and lower GNR layers were designed and their electronic and transport properties were investigated by employing density functional theory (DFT) and nonequilibrium Green's function (NEGF) methods. Adding the Fe atoms induces high spin magnetism in the systems. Within the considered bias, almost all Fe2/C60-GNR devices generate double NDR peaks, and some of the Fen/C60-GNR devices (n = 2 and 4) possess a large peak-to-valley current ratio R = Ipeak/Ivalley (>400), implying potential applications in developing on–off–on/off–on–off current switches. The NDR character originates from the crossing of the frontier molecular orbitals. In addition, these systems show distinct spin-polarized transport characteristics, with up-spin channels displaying higher conductivity than down-spin pathways. The spin filter efficiency (SFE) oscillates up and down as bias is scanned for almost all devices, suggesting the possibility of designing on–off–on/off–on–off current switches as well as up–down spin switches. All these findings provide guidance for exploring single molecular devices with promising properties combined with graphene, fullerenes, and transition metals. [ABSTRACT FROM AUTHOR]