Acoustic transmission enhancement through a periodically-structured stiff plate without any opening

We report both experimentally and theoretically that the enhanced acoustic transmission can occur in the subwavelength region through a thin but stiff structured-plate without any opening. This exotic acoustic phenomenon is essentially distinct from the previous related studies originated from, either collectively or individually, the interaction of the incident wave with openings in previous structures. It is attributed to the structure-induced resonant excitation of the non-leaky Lamb modes that exist intrinsically in the uniform elastic plate. Our finding should have impact on ultrasonic applications.Comment: 11 pages, 4 figure

Plasma deposition of thin carbonfluorine films on aligned carbon nanotube

The thin film of carbonfluorine was deposited on the surfaces of aligned carbon nanotubes using a plasma polymerization treatment. High-resolution transmission electron microscopy images revealed that a thin film of the polymer layer (20 nm)(20nm) was uniformly deposited on the surfaces of the aligned carbon nanotubes. Time-of-flight secondary ion mass spectroscopy and Fourier transform infrared experiments identified the carbonfluorine thin films on the carbon nanotubes. The plasma deposition mechanism is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87850/2/043107_1.pd

Magnetic alignment of carbon nanofibers in polymer composites and anisotropy of mechanical properties

Engineering applications of carbon nanofibers and nanotubes require their alignment in specific directions. Single-walled carbon nanotubes can be aligned in a magnetic field due to the presence of small amounts of catalyst elements, such as Ni and Co. However, for carbon nanofibers, their extremely low magnetic susceptibility is not sufficient for magnetically induced alignment. We present a method of solution-coating of NiO and CoO onto the surface of the carbon nanofibers. Due to the NiO- and CoO-coating, these nanofibers can be well aligned in the polymer composites under moderate magnetic field (3 T). Both transmission electron microscopy and scanning electron microscopy results show the well-aligned nanofibers in a polymer matrix. Mechanical testing shows a pronounced anisotropy in tensile strength in directions normal (12.1 MPa) and parallel (22 MPa) to the applied field, resulting from the well-aligned nanofibers in the polymer matrix. The mechanism of magnetic alignment due to coating of NiO and CoO on the nanofiber surface is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87644/2/064312_1.pd

Dynamic Phase Transition, Universality, and Finite-size Scaling in the Two-dimensional Kinetic Ising Model in an Oscillating Field

We study the two-dimensional kinetic Ising model below its equilibrium critical temperature, subject to a square-wave oscillating external field. We focus on the multi-droplet regime where the metastable phase decays through nucleation and growth of many droplets of the stable phase. At a critical frequency, the system undergoes a genuine non-equilibrium phase transition, in which the symmetry-broken phase corresponds to an asymmetric stationary limit cycle for the time-dependent magnetization. We investigate the universal aspects of this dynamic phase transition at various temperatures and field amplitudes via large-scale Monte Carlo simulations, employing finite-size scaling techniques adopted from equilibrium critical phenomena. The critical exponents, the fixed-point value of the fourth-order cumulant, and the critical order-parameter distribution all are consistent with the universality class of the two-dimensional equilibrium Ising model. We also study the cross-over from the multi-droplet to the strong-field regime, where the transition disappears

Monophyletic origin of domestic bactrian camel (Camelus bactrianus) and its evolutionary relationship with the extant wild camel (Camelus bactrianus ferus)

The evolutionary relationship between the domestic bactrian camel and the extant wild two-humped camel and the factual origin of the domestic bactrian camel remain elusive. We determined the sequence of mitochondrial cytb gene from 21 camel samples, including 18 domestic camels (three Camelus bactrianus xinjiang, three Camelus bactrianus sunite, three Camelus bactrianus alashan, three Camelus bactrianus red, three Camelus bactrianus brown and three Camelus bactrianus normal) and three wild camels (Camelus bactrianus ferus). Our phylogenetic analyses revealed that the extant wild two-humped camel may not share a common ancestor with the domestic bactrian camel and they are not the same subspecies at least in their maternal origins. Molecular clock analysis based on complete mitochondrial genome sequences indicated that the sub-speciation of the two lineages had begun in the early Pleistocene, about 0.7 million years ago. According to the archaeological dating of the earliest known two-humped camel domestication (5000–6000 years ago), we could conclude that the extant wild camel is a separate lineage but not the direct progenitor of the domestic bactrian camel. Further phylogenetic analysis suggested that the bactrian camel appeared monophyletic in evolutionary origin and that the domestic bactrian camel could originate from a single wild population. The data presented here show how conservation strategies should be implemented to protect the critically endangered wild camel, as it is the last extant form of the wild tribe Camelina

The Effects of the Acupuncture Treatment for Smoking Cessation in High School Student Smokers

The use of alternative medicine for smoking cessation have been increasing steadily in recent years. A series of clinical group studies was performed to clarify the effect, outcome and success rate of an acupuncture treatment for smoking cessation. This study was conducted for four weeks using 238 smoking students at 2 high schools. The subjects were separated into two groups: 159 students were treated with acupuncture on the anti-smoking acupoints of the ear, which is known to be effective for cessation of smoking (case group), and 79 students were treated at other sites of the ear (control group). The acupuncture treatment was alternately administered at each side of the ears on a weekly basis for 4 weeks. The smoking cessation success was only 1 case (0.6%) in the case group and none in the control group after 4 weeks. The change in the taste of tobacco and the intensity of the desire to smoke were not significantly different between the case and control groups, but the case group showed a tendency of reduction in the taste of tobacco and the intensity of the desire to smoke. In addition, the reduction in cigarette consumption was not significant, but the tendency of reduction in the study group was significant. It is believed that the site of auricular acupuncture for smoking cessation is not important. However, there was a significant tendency in terms of the reduction in cigarette consumption, the taste of tobacco and the intensity of the desire to smoke in the case group, indicating that auricular acupuncture in smoking cessation has some effect

Divergent human remodeling complexes remove nucleosomes from strong positioning sequences

Nucleosome positioning plays a major role in controlling the accessibility of DNA to transcription factors and other nuclear processes. Nucleosome positions after assembly are at least partially determined by the relative affinity of DNA sequences for the histone octamer. Nucleosomes can be moved, however, by a class of ATP dependent chromatin remodeling complexes. We recently showed that the human SWI/SNF remodeling complex moves nucleosomes in a sequence specific manner, away from nucleosome positioning sequences (NPSes). Here, we compare the repositioning specificity of five remodelers of diverse biological functions (hSWI/SNF, the SNF2h ATPase and the hACF, CHRAC and WICH complexes than each contain SNF2h) on 5S rDNA, MMTV and 601 NPS polynucleosomal templates. We find that all five remodelers act similarly to reduce nucleosome occupancy over the strongest NPSes, an effect that could directly contribute to the function of WICH in activating 5S rDNA transcription. While some differences were observed between complexes, all five remodelers were found to result in surprisingly similar nucleosome distributions. This suggests that remodeling complexes may share a conserved repositioning specificity, and that their divergent biological functions may largely arise from other properties conferred by complex-specific subunits

Vibrational biospectroscopy characterises biochemical differences between cell types used for toxicological investigations and identifies alterations induced by environmental contaminants

The use of cell-based assays is essential in reducing the number of vertebrates used in the investigation of chemical toxicities and in regulatory toxicology assessment. An important factor in obtaining meaningful results which can be accurately extrapolated is the use of biologically appropriate cell lines. In this preliminary study, ATR-FTIR spectroscopy with multivariate analysis was used to assess the fundamental biomolecular differences between a commonly used cell line, MCF-7 cells, and an environmentally relevant cell line derived from Mallard (Anas platyrhynchos) dermal fibroblasts. To better understand differences in basic cell biochemistry, the cells were analysed in the untreated state or post-exposure to PCB and PBDE congeners. The main spectral peaks in spectra from both cell types were associated with cellular macromolecules, particularly proteins and lipids but the spectra also revealed some cell-specific differences. Spectra from untreated Mallard fibroblasts spectra contained a large peak associated with lipids. The cell-related differences in lipid and DNA were also identified as regions of spectral alteration induced by PBDE and PCB exposure. Although lipid alterations were observed in post-treatment spectra from both cell types, these may be of more significance to Mallard fibroblasts, which may be due to increased intracellular lipid as determined by Nile red staining. Untreated MCF-7 cell spectra contained unique peaks related to DNA and nucleic acids. DNA associated spectral regions were also identified as areas of considerable alteration in MCF-7 cells exposed to some congeners including PBDE 47 and PCB 153. The findings indicate that in their native state, MCF-7 and Mallard cells have unique biochemical differences, which can be identified using ATR-FTIR spectroscopy. Such differences in biochemical composition differences, which may influence cell susceptibility to environmental contaminants and therefore influence the choice of cell type used in toxicology experiments. This is the first study to analyse the biochemistry of a Mallard dermal fibroblast cell line and to use ATR-FTIR spectroscopy for this purpose. ATR-FTIR spectroscopy is demonstrated as a useful tool for exploration of biomolecular variation at the cellular level and with further development, it could be used as part of a panel of cell-based assays to indicate when different results might be seen in environmental species compared to currently used cell lines. This article is protected by copyright. All rights reserve

CHILD: a new tool for detecting low-abundance insertions and deletions in standard sequence traces

Several methods have been proposed for detecting insertion/deletions (indels) from chromatograms generated by Sanger sequencing. However, most such methods are unsuitable when the mutated and normal variants occur at unequal ratios, such as is expected to be the case in cancer, with organellar DNA or with alternatively spliced RNAs. In addition, the current methods do not provide robust estimates of the statistical confidence of their results, and the sensitivity of this approach has not been rigorously evaluated. Here, we present CHILD, a tool specifically designed for indel detection in mixtures where one variant is rare. CHILD makes use of standard sequence alignment statistics to evaluate the significance of the results. The sensitivity of CHILD was tested by sequencing controlled mixtures of deleted and undeleted plasmids at various ratios. Our results indicate that CHILD can identify deleted molecules present as just 5% of the mixture. Notably, the results were plasmid/primer-specific; for some primers and/or plasmids, the deleted molecule was only detected when it comprised 10% or more of the mixture. The false positive rate was estimated to be lower than 0.4%. CHILD was implemented as a user-oriented web site, providing a sensitive and experimentally validated method for the detection of rare indel-carrying molecules in common Sanger sequence reads

SePreSA: a server for the prediction of populations susceptible to serious adverse drug reactions implementing the methodology of a chemical–protein interactome

Serious adverse drug reactions (SADRs) are caused by unexpected drug–human protein interactions, and some polymorphisms within binding pockets make the population carrying these polymorphisms susceptible to SADR. Predicting which populations are likely to be susceptible to SADR will not only strengthen drug safety, but will also assist enterprises to adjust R&D and marketing strategies. Making such predictions has recently been facilitated by the introduction of a web server named SePreSA. The server has a comprehensive collection of the structural models of nearly all the well known SADR targets. Once a drug molecule is submitted, the scale of its potential interaction with multi-SADR targets is calculated using the DOCK program. The server utilizes a 2-directional Z-transformation scoring algorithm, which computes the relative drug–protein interaction strength based on the docking-score matrix of a chemical–protein interactome, thus achieve greater accuracy in prioritizing SADR targets than simply using dock scoring functions. The server also suggests the binding pattern of the lowest docking score through 3D visualization, by highlighting and visualizing amino acid residues involved in the binding on the customer's browser. Polymorphism information for different populations for each of the interactive residues will be displayed, helping users to deduce the population-specific susceptibility of their drug molecule. The server is freely available at http://SePreSA.Bio-X.cn/