1,021 research outputs found

    Perspectives of Chitin Deacetylase Research

    Get PDF

    Poly[[μ-aqua-bis­(μ-4,4′-bipyridine-κ2 N:N′)bis­(μ-3-hy­droxy­adamantane-1-carboxyl­ato-κ2 O:O′)bis­(3-hy­droxy­adamantane-1-carboxyl­ato-κO)dicobalt(II)] hepta­hydrate]

    Get PDF
    The title coordination compound, {[Co(C11H15O3)4(C10H8N2)2(H2O)]·7H2O}n, consists of a pair of CoII atoms, four 3-hy­droxy­adamantane-1-carboxyl­ate anions (L), one water mol­ecule, two bridging 4,4′-bipyridine (4,4′-bpy) ligands and seven uncoordinated water mol­ecules. Both of the CoII ions are coordinated in a distorted octa­hedral geometry. Four L ligands bind to each pair of CoII atoms in a plane, two of which bridge the two CoII atoms as bidentate groups while the other two coordinate to a single CoII atom in a monodentate mode. Two half-mol­ecules of 4,4′-bipyridine coordinate the CoII atoms from the upside and underside. The packing features extensice O—H⋯O hydrogen bonding

    Observation of room-temperature ferroelectricity in elemental Te nanowires

    Full text link
    Ferroelectrics are essential in low-dimensional memory devices for multi-bit storage and high-density integration. A polar structure is a necessary premise for ferroelectricity, mainly existing in compounds. However, it is usually rare in elemental materials, causing a lack of spontaneous electric polarization. Here, we report an unexpected room-temperature ferroelectricity in few-chain Te nanowires. Out-of-plane ferroelectric loops and domain reversal are observed by piezoresponse force microscopy. Through density functional theory, we attribute the ferroelectricity to the ion-displacement created by the interlayer interaction between lone pair electrons. Ferroelectric polarization can induce a strong field effect on the transport along the Te chain, supporting a self-gated field-effect transistor. It enables a nonvolatile memory with high in-plane mobility, zero supply voltage, multilevel resistive states, and a high on/off ratio. Our work provides new opportunities for elemental ferroelectrics with polar structures and paves a way towards applications such as low-power dissipation electronics and computing-in-memory devices

    The genetic load for hereditary hearing impairment in Chinese population and its clinical implication

    Get PDF
    AbstractObjectiveTo understand the genetic load in the Chinese population for improvement in diagnosis, prevention and rehabilitation of deafness.MethodsDNA samples, immortalized cell lines as well as detailed clinical and audiometric data were collected through a national genetic resources collecting network. Two conventional genetic approaches were used in the studies. Linkage analysis in X chromosome and autosomes with microsatellite markers were performed in large families for gene mapping and positional cloning of novel genes. Candidate gene approach was used for screening themtDNA 12SrRNA, GJB2andSLC26A4mutations in population–based samples.ResultsA total of 2, 572 Chinese hearing loss families or sporadic cases were characterized in the reported studies, including seven X–linked, one Y–linked, 28 large and multiplex autosomal dominant hearing loss families, 607 simplex autosomal recessive hereditary hearing loss families, 100 mitochondrial inheritance families, 147GJB2induced hearing loss cases, 230 cases with enlarged vestibular aqueduct (EVA) syndrome, 169 sporadic cases with auditory neuropathy, and 1, 283 sporadic sensorineural hearing loss cases. Through linkage analysis or sequence analysis, two X–linked families were found transmitting two novel mutations in thePOU3F4gene, while another X–linked family was mapped onto a novel locus, nominated asAUNX1(auditory neuropathy, X–linked locus 1). The only Y–linked family was mapped onto theDFNY1locus (Y–linked locus 1,DFNY1). Eight of the 28 autosomal dominant families were linked to various autosomal loci. In population genetics studies, 2, 567 familial cases and sporadic patients were subjected to mutation screening for three common hearing loss genes:mtDNA 12S rRNA 1555G, GJB2andSLC26A4.The auditory neuropathy cases in our samples were screened forOTOFgene mutations.ConclusionsThese data show that the Chinese population has a genetic load on hereditary hearing loss. Establishing personalized surveillance and prevention models for hearing loss based on genetic research will provide the opportunity to decrease the prevalence of deafness in the Chinese population

    Unconventional Origin and Hybrid System for Construction of Pyrrolopyrrole Moiety in Kosinostatin Biosynthesis

    Get PDF
    SummaryKosinostatin (KST), an antitumor antibiotic, features a pyrrolopyrrole moiety spirally jointed to a five-membered ring of an anthraquinone framework glycosylated with a γ-branched octose. By a combination of in silico analysis, genetic characterization, biochemical assay, and precursor feeding experiments, a biosynthetic pathway for KST was proposed, which revealed (1) the pyrrolopyrrole moiety originates from nicotinic acid and ribose, (2) the bicyclic amidine is constructed by a process similar to the tryptophan biosynthetic pathway, and (3) a discrete adenylation enzyme and a peptidyl carrier protein (PCP) are responsible for producing a PCP-tethered building block parallel to type II polyketide synthase (PKS) rather than for the PKS priming step by providing the starter unit. These findings provide an opportunity to further explore the inexplicable enzymatic logic that governs the formation of pyrrolopyrrole moiety and the spirocyclic skeleton

    Evaluation of primary HPV-DNA testing in relation to visual inspection methods for cervical cancer screening in rural China: an epidemiologic and cost-effectiveness modelling study

    Get PDF
    BACKGROUND: A new lower-cost rapid-throughput human papillomavirus (HPV) test (careHPV, Qiagen, Gaithersburg, USA) has been shown to have high sensitivity for the detection of high grade cervical intraepithelial neoplasia. METHODS: We assessed the outcomes and cost-effectiveness of careHPV screening in rural China, compared to visual inspection with acetic acid, when used alone (VIA) or in combination with Lugol's iodine (VIA/VILI). Using data on sexual behaviour, test accuracy, diagnostic practices and costs from studies performed in rural China, we estimated the cost-effectiveness ratio (CER) and associated lifetime outcomes for once-lifetime and twice-lifetime screening strategies, and for routine screening at 5-yearly, 10-yearly and IARC-recommended intervals. The optimal age range for once-lifetime screening was also assessed. RESULTS: For all strategies, the relative ordering of test technologies in reducing cervical cancer incidence and mortality was VIA (least effective); VIA/VILI; [email protected] pg/ml and [email protected] pg/ml (most effective). For once-lifetime strategies, maximum effectiveness was achieved if screening occurred between 35-50 years. Assuming a participation rate of ~70%, once-lifetime screening at age 35 years would reduce cancer mortality by 8% (for VIA) to 12% (for [email protected]) over the long term, with a CER of US557(forVIA)to557 (for VIA) to 959 (for [email protected]) per life year saved (LYS) compared to no intervention; referenced to a 2008 GDP per capita in Shanxi Province of 2,975.Correspondingly,regularscreeningwithanagestandardisedparticipationrateof622,975. Correspondingly, regular screening with an age-standardised participation rate of 62% (which has been shown to be achievable in this setting) would reduce cervical cancer mortality by 19-28% (for 10-yearly screening) to 43-54% (using IARC-recommended intervals), with corresponding CERs ranging from 665 (for 10-yearly VIA) to $2,269 (for IARC-recommended intervals using [email protected]) per LYS. CONCLUSIONS: This modelled analysis suggests that primary careHPV screening compares favourably to visual inspection screening methodologies in rural China, particularly if used as part of a regular screening program

    Inhibitory Effects of the Attenuated Salmonella typhimurium

    Get PDF
    To observe the inhibitory effects of an attenuated S. typhimurium strain carrying IL-2 gene (TPI) on hepatoma cell line (HepG2) and transplanted tumors in mice. TPI, TPG (an attenuated S. typhimurium strain carrying green fluorescent protein gene), and TP (an attenuated S. typhimurium strain) strains were transfected into HepG2 cells. At 48h after transfecting, the transfection rate was 82.58 ± 1.74%. The expression level of IL-2 was (99.5 ± 12.2) ng/1×106 cells. Compared with TPG, TP, and normal mouse groups, the proportion of CD4+ T and CD8+ T cells in the blood from the TPI group was higher, the levels of IgM and IgG1 were significantly increased, and the proliferation activity of splenic lymphocyte was significantly stronger. The transplanted tumor weight in the TPI group was significantly smaller than that in the other two groups. The infiltration of lymphocytes increased in the tumor from TPI group mice. TPI was effectively transfected into cancer cells, which expressed the protein of interest. Oral administration of TPI prolonged survival of mice transplanted with hepatoma cell tumours
    corecore