As a first step in a program to use genetically altered mice in the study of memory mechanisms, mutant mice were produced that do not express the alpha-calcium-calmodulin-dependent kinase II (alpha-CaMKII). The alpha-CaMKII is highly enriched in postsynaptic densities of hippocampus and neocortex and may be involved in the regulation of long-term potentiation (LTP). Such mutant mice exhibited mostly normal behaviors and presented no obvious neuroanatomical defects. Whole cell recordings reveal that postsynaptic mechanisms, including N-methyl-D-aspartate (NMDA) receptor function, are intact. Despite normal postsynaptic mechanisms, these mice are deficient in their ability to produce LTP and are therefore a suitable model for studying the relation between LTP and learning processes.
Binary metal oxides with three-dimensional (3D) superstructure have been regarded as desirable electrode materials for the supercapacitor due to the combination of the improved electrical conductivity and effective porous structure. 3D hierarchical flower-shaped nickel cobaltite (NiCo2O4) microspheres have been fabricated by a rapid and template-free microwave-assisted heating (MAH) reflux approach followed by pyrolysis of the as-prepared precursors. The flower-shaped NiCo2O4 microspheres, composed of ultrathin nanopetals with thickness of about 15 nm, are endowed with large specific surface area (148.5 m(2) g(-1)) and a narrow pore size distribution (5-10 nm). The as-fabricated porous flower-shaped NiCo2O4 microspheres as electrode materials for supercapacitor exhibited high specific capacitance of 1006 F g(-1) at 1 A g(-1), enhanced rate capability, and excellent electrochemical stability with 93.2% retention after 1000 continuous charge-discharge (CD) cycles even at a high current density of 8 A g(-1). The desirable integrated performance enables it to be a promising electrode material for the electrochemical supercapacitor (EC).
A 3D-nanonet structured cobalt-basic-carbonate precursor has been obtained by a facile, low cost and eco-friendly route under ambient temperature and pressure. After calcination in air, the as-prepared precursor was converted to a 3D-nanonet hollow structured Co3O4 with its original frame structure almost preserved. Encouragingly, by alternating experimental parameters (Table S1 in the Supporting Information ), such as concentration of the starting reagents and calcination temperature, we got the optimized condition for the final product with desirable electrochemical performance (Figure S1 in the Supporting Information ). The pseudocapacitive properties of the obtained Co3O4 were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge measurement and electrochemical impedance spectroscopy in 6.0 M KOH solution. At different scan rates of 5, 10, 20, and 30 mV s(-1), the corresponding specific capacitances were 820, 755, 693, and 656 F g(-1), respectively. The material also exhibited superior charge-discharge stability and maintained 90.2% of its initial capacitance after 1000 continuous charge-discharge cycles at a current density of 5 A g(-1). From a broad view, our research and the outstanding results not only present a feasible access to nanostructured Co3O4 but also remind us of paying more attention to the simple synthetic methods without complex processes and sophisticated instruments.
We examine the association between borrower (firm) and lender (bank) state ownership and accounting
conservatism for a sample of Chinese firms. We hypothesize that state-owned enterprises (SOEs) adopt less
conservative accounting than non-state-owned enterprises (NSOEs) because lenders are less concerned with
downside risk for SOEs than for NSOEs. We also hypothesize a negative relation between conservatism and the
fraction of total loans a firm borrows from state-owned banks (SBs) because SBs have weaker demand for assurance
of sufficient net assets to cover loan repayments than non-state-owned banks (NSBs). We find support for both
hypotheses. Further analyses reveal that: (1) firms that borrow from commercial SBs exhibit more conservative
accounting than firms that borrow from policy SBs and (2) firms adopt more conservative accounting as they get
more loans from banks with foreign ownership or exclusively foreign banks. However, the results of these additional
analyses are to some extent sensitive to alternative measures of accounting conservatism
BackgroundLichen is a classic mutualistic organism and the lichenization is one of the fungal symbioses. The lichen-forming fungus Endocarpon pusillum is living in symbiosis with the green alga Diplosphaera chodatii Bialsuknia as a lichen in the arid regions.Results454 and Illumina technologies were used to sequence the genome of E. pusillum. A total of 9,285 genes were annotated in the 37.5 Mb genome of E. pusillum. Analyses of the genes provided direct molecular evidence for certain natural characteristics, such as homothallic reproduction and drought-tolerance. Comparative genomics analysis indicated that the expansion and contraction of some protein families in the E. pusillum genome reflect the specific relationship with its photosynthetic partner (D. chodatii). Co-culture experiments using the lichen-forming fungus E. pusillum and its algal partner allowed the functional identification of genes involved in the nitrogen and carbon transfer between both symbionts, and three lectins without signal peptide domains were found to be essential for the symbiotic recognition in the lichen; interestingly, the ratio of the biomass of both lichen-forming fungus and its photosynthetic partner and their contact time were found to be important for the interaction between these two symbionts.ConclusionsThe present study lays a genomic analysis of the lichen-forming fungus E. pusillum for demonstrating its general biological features and the traits of the interaction between this fungus and its photosynthetic partner D. chodatii, and will provide research basis for investigating the nature of its drought resistance and symbiosis.
Sensors based on single-walled carbon nanotube (SWNT) networks were fabricated and their sensitive properties for the nerve agent stimulant dimethyl methylphosphonate (DMMP) vapor were investigated at room temperature. The SWNT networks were deposited on oxidized silicon surface functionalized with 3-aminopropyltrimethysilane (APS). Combining with a traditional silicon process, SWNT-based gas sensors were made at a wafer scale. The effects of the density of deposited SWNTs on the sensor response were studied. The excellent response is obtained under a density of 30-40 tubes microm(-2). The sensors exhibit high resistance response, fast response time, rapid recovery and good reproducibility for DMMP vapor. The deposited SWNT sensors will be potentially extended to large-scale fabrication.
Porous current collectors are conducive to enhance the property of Li metal anode. Unfortunately, congestion in diffusion path during plating process damages the effects of current collectors. Herein, we developed a 3D Cu skeleton with open micrometer-sized pores by NaCl-assisted powder-sintering method. The unobstructed pores of 3D Cu skeleton help to reduce congestion during plating, thus most of Li deposited inside the current collector. Besides, the large smooth surface promotes the deposition of Li with smooth spherical shape, which mitigating Li dendrite growth. As a result, better safety and rechargeability of Li metal anode were achieved in this design.
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