Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of ...sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'.
Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of ...sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'.
We studied the luminescent and photovoltaic properties of poly(9,9-dioctylfluorene-co-bithiophene) (F8T2) based on ITO/PEDOT:PSS/F8T2/Bphen/LiF(0 or 1 nm)/Al and ITO/PEDOT:PSS/F8T2:PCBM/Bphen/Al. A ...stable and bright yellow emission was obtained from polymer F8T2, and the electroluminescence power reached 45 μW at a 15 V driving voltage. Polymer F8T2 shows a broad absorption band from 400 to 500 nm, and has a shorter absorption edge at about 560 nm compared to that of the typical electron donor P3HT (650 nm). The photoluminescence quenching of F8T2 occurs with only a small fraction of blended PCBM due to the effective exciton dissociation at the interface between F8T2 and PCBM. Polymer solar cells (PSCs) using F8T2:PCBM as the active layer show a low power conversion efficiency (PCE) of 0.10% with an open circuit voltage (V oc) of 0.91 V and short circuit current density (J sc) of 0.23 mA/cm2. The PSCs using F8T2:P3HT:PCBM as the active layer have a V oc of 0.85 V and J sc of 3.02 mA/cm2, improving the PCE by about 0.90%. We attribute the improved cell performance to the higher number of photons harvested by P3HT molecules.
An entanglement concentration scheme for unknown atomic entanglement states is proposed via entanglement swapping in cavity QED. Because the interaction used here is a large-detuned one between two ...driven atoms and a quantized cavity mode, the effects of the cavity decay and thermal field have been eliminated. These advantages can warrant the experimental feasibility of the current scheme.
Electrophysiological studies were conducted in three groups of mice to determine the possible involvement of the antibodies to presynaptic membrane receptor (PsmR), a beta-bungarotoxin (beta-BuTX) ...binding protein, in the pathogenesis of myasthenia gravis (MG). Mice were untreated (untreated group, n = 8) or were injected (i.p.) with blood plasma from a MG patient, which contained antibodies to PsmR, at a dose of 1 ml per day for more than 2 months (MG plasma group, n = 12) or with plasma from healthy subjects (normal plasma group, n = 10). Prior to plasma injection, cyclophosphamide was given at 300 mg/kg (i.p.) to all three groups. About three weeks after plasma injection, most mice of the MG plasma group became less mobile in comparison with those of the two control groups. Electrophysiological recording showed three main changes in the MG plasma group: (1) the increase in the frequency of miniature endplate potentials (mEPPs) induced by Krebs solution with high K+ concentration (17.5 mM) was significantly lowered, which was confirmed in mice injected with IgG (50 mg per day) from this patient for two days; (2) the quantal content of EPP was decreased; and (3) the decrement in the amplitude of a train EPP (50 Hz) was quickened. Our results suggest that this experimental model is different from that of Lambert-Eaton myasthenic syndrome and that antibodies to PsmR may also be involved in the pathogenesis of MG.
A scheme of implementing the Grover search algorithm based on Josephson charge qubits has been proposed, which would be a key step to scale more complex quantum algorithms and very important for ...constructing a real quantum computer via Josephson charge qubits. The present scheme is simple but fairly efficient, and easily manipulated because any two-charge-qubit can be selectively and effectively coupled by a common inductance. More manipulations can be carried out before decoherence sets in. Our scheme can be realized within the current technology.
The mutation of B-Rafv600E is widespread in a variety of human cancers. Its inhibitors vemurafenib and dabrafenib have been launched as drugs for treating unresectable melanoma, demonstrating that ...B-Rafv600E is an ideal drug target. This study focused on developing novel B-Rafv600E inhibitors as drug leads against various cancers with B-Rafv600E mutation. Using molecular modeling approaches, 200 blockbuster drugs were spliced to generate 283 fragments followed by molecular docking to identify potent fragments. Molecular structures of potential inhibitors of B-Rafv600E were then obtained by fragment reassembly followed by docking to predict the bioactivity of the reassembled molecules. The structures with high predicted bioactivity were synthesized, followed by in vitro study to identify potent B-Rafv600E inhibitors. A highly potent fragment binding to the hinge area of B-Rafv600E was identified via a docking-based structural splicing approach. Using the fragment, 14 novel structures were designed by structural reassembly, two of which were predicted to be as strong as marketed B-Rafv600E inhibitors. Biological evaluation revealed that compound lm is a potent B-Rafv600E inhibitor with an IC50 value of 0.05 μmol/L, which was lower than that of vemurafenib （0.13 μmol/L）. Moreover, the selectivity of lm against B-RafwT was enhanced compared with vemurafenib. In addition, lm exhibits desirable solubility, bioavailability and metabolic stability in in vitro assays, Thus, a highly potent and selective B-Rafv600E inhibitor was designed via a docking-based structural splicing and reassembly strategy and was validated by medicinal synthesis and biological evaluation.
A scheme for implementing 2-qubit quantum controlled phase gate (QCPG) is proposed with two superconducting quantum interference devices (SQUIDs) in a cavity. The gate operations are realized within ...the two lower flux states of the SQUIDs by using a quantized cavity field and classical microwave pulses. Our scheme is achieved without any type of measurement, does not use the cavity mode as the data bus and only requires a very short resonant interaction of the SQUID-cavity system. As an application of the QCPG operation, we also propose a scheme for generating the cluster states of many SQUIDs.
We investigate a scheme for implementing quantum dense coding via atomic ensembles, where prior distribution of the quantum entangled state is not needed. Our scheme also combines another two ...distinct advantages: atomic ensembles qubits with long coherent time serve as memory qubits and phtonic qubit as flying qubit. Thus our suggestion may offer a simple and easy way of demonstrating quantum dense coding experimentally via atomic ensembles.
A scheme for the generation of the cluster states based on the Josephson charge qubit is proposed. The two-qubit generating case is first introduced, and then generalized to multi-qubit case. The ...scheme is simple and easily manipulated, because any two charge qubits can be selectively and effectively coupled by a common inductance. More manipulations can be realized before decoherence sets in. All the devices in the scheme are well within the current technology.
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