Description: Article So-called two-dimensional superconductivity has been reported in several material systems but just how thin a system can be and maintain a superconducting state has been difficult to determine. Da Jiang and colleagues demonstrate that Bi2Sr2CaCu2O8+ x continues to be superconducting even when it is just half a unit cell thick. Nature Communications doi: 10.1038/ncomms6708 Authors: Da Jiang, Tao Hu, Lixing You, Qiao Li, Ang Li, Haomin Wang, Gang Mu, Zhiying Chen, Haoran Zhang, Guanghui Yu, Jie Zhu, Qiujuan Sun, Chengtian Lin, Hong Xiao, Xiaoming Xie, Mianheng Jiang

Description: Article Multilevel societies (MLS) are a complex form of group organization found in mammals, yet the origin of MLS is poorly understood. Here the authors show that MLS of the golden snub-nosed monkey evolved from the aggregation of independent one-male, multifemale units found in ancestral Asian colobines. Nature Communications doi: 10.1038/ncomms6296 Authors: Xiao-Guang Qi, Paul A. Garber, Weihong Ji, Zhi-Pang Huang, Kang Huang, Peng Zhang, Song-Tao Guo, Xiao-Wei Wang, Gang He, Pei Zhang, Bao-Guo Li

Description: Background: Breast milk contains complex nutrients and facilitates the maturation of various biological systems in infants. Exosomes, membranous vesicles of endocytic origin found in different body fluids such as milk, can mediate intercellular communication. We hypothesized that microRNAs (miRNAs), a class of non-coding small RNAs of 18-25 nt which are known to be packaged in exosomes of human, bovine and porcine milk, may play important roles in the development of piglets. Results: In this study, exosomes of approximately 100 nm in diameter were isolated from porcine milk through serial centrifugation and ultracentrifugation procedures. Total RNA was extracted from exosomes, and 5S ribosomal RNA was found to be the major RNA component. Solexa sequencing showed a total of 491 miRNAs, including 176 known miRNAs and 315 novel mature miRNAs (representing 366 pre-miRNAs), which were distributed among 30 clusters and 35 families, and two predicted novel miRNAs were verified targeting 3'UTR of IGF-1R by luciferase assay. Interestingly, we observed that three miRNAs (ssc-let-7e, ssc-miR-27a, and ssc-miR-30a) could be generated from miRNA-offset RNAs (moRNAs). The top 10 miRNAs accounted for 74.5% (67,154 counts) of total counts, which were predicted to target 2,333 genes by RNAhybrid software. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses using DAVID bioinformatics resources indicated that the identified miRNAs targeted genes enriched in transcription, immunity and metabolism processes, and 14 of the top 20 miRNAs possibly participate in regulation of the IgA immune network. Conclusions: Our findings suggest that porcine milk exosomes contain a large number of miRNAs, which potentially play an important role in information transfer from sow milk to piglets. The predicted miRNAs of porcine milk exosomes in this study provide a basis for future biochemical and biophysical function studies.

Description: The two-body interception problem with an upper-bounded tangent impulse for the interceptor on an elliptic parking orbit to collide with a nonmaneuvering target on a hyperbolic orbit is studied. Firstly, four special initial true anomalies whose velocity vectors are parallel to either of the lines of asymptotes for the target hyperbolic orbit are obtained by using Newton-Raphson method. For different impulse points, the solution-existence ranges of the target true anomaly for any conic transfer are discussed in detail. Then, the time-of-flight equation is solved by the secant method for a single-variable piecewise function about the target true anomaly. Considering the sphere of influence of the Earth and the upper bound on the fuel, all feasible solutions are obtained for different impulse points. Finally, a numerical example is provided to apply the proposed technique for all feasible solutions and the global minimum-time solution with initial coasting time.

Description: Background: Auxin signaling has a vital function in the regulation of plant growth and development, both which are known to be mediated by auxin-responsive genes. So far, significant progress has been made toward the identification and characterization of auxin-response genes in several model plants, while no systematic analysis for these families was reported in cucumber (Cucumis sativus L.), a reference species for Cucurbitaceae crops. The comprehensive analyses will help design experiments for functional validation of their precise roles in plant development and stress responses. Results: A genome-wide search for auxin-response gene homologues identified 16 auxin-response factors (ARFs), 27 auxin/indole acetic acids (Aux/IAAs), 10 Gretchen Hagen 3 (GH3s), 61 small auxin-up mRNAs (SAURs), and 39 lateral organ boundaries (LBDs) in cucumber. Sequence analysis together with the organization of putative motifs indicated the potential diverse functions of these five auxin-related family members. The distribution and density of auxin response-related genes on chromosomes were not uniform. Evolutionary analysis showed that the chromosomal segment duplications mainly contributed to the expansion of the CsARF, CsIAA, CsGH3, and CsLBD gene families. Quantitative real-time RT-PCR analysis demonstrated that many ARFs, AUX/IAAs, GH3s, SAURs, and LBD genes were expressed in diverse patterns within different organs/tissues and during different development stages. They were also implicated in IAA, methyl jasmonic acid, or salicylic acid response, which is consistent with the finding that a great number of diverse cis-elements are present in their promoter regions involving a variety of signaling transduction pathways. Conclusion: Genome-wide comparative analysis of auxin response-related family genes and their expression analysis provide new evidence for the potential role of auxin in development and hormone response of plants. Our data imply that the auxin response genes may be involved in various vegetative and reproductive developmental processes. Furthermore, they will be involved in different signal pathways and may mediate the crosstalk between various hormone responses.

Description: The purpose of this meta-analysis was to evaluate the utility of positron emission tomography (PET) using fluor-18-deoxyglucose (FDG) to predict the response of rectal cancer to neo-adjuvant therapy. All previously published studies on the role of FDG-PET in predicting the response of rectal cancer to neo-adjuvant therapy were collected. Pooled sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using statistical software. A total of 28 studies, comprising 1204 patients with rectal cancer, were included in the meta-analysis. Pooled sensitivity, specificity, PPV and NPV for FDG-PET predicting the response to therapy was 78% (95%CI, 75%-82%), 66% (95%CI, 62%-69%), 70% (95%CI, 66%-73%) and 75% (95%CI, 71%-0.79%), respectively. The included studies were of a relatively high methodological quality according to the QUADAS (Quality Assessment of Studies of Diagnostic Accuracy Included in Systematic Reviews) criteria. Based on the subgroup analyses, there was no significant difference between the response index (RI), the standardised uptake value (SUV) and the visual response score (VRS) in predicting the therapy response. However, the accuracy of the group that underwent PET scanning during therapy showed significantly higher values (sensitivity 86% and specificity 80%) than the group that was scanned after completion of the therapy. Therefore, FDG- PET is valuable for predicting the response of rectal carcinoma to neo-adjuvant therapy, and early evaluation of response during the therapy may be more promising. However, additional studies using prospective clinical trials will be required to assess the clinical benefit of this strategy. © 2012 Wiley-Liss, Inc.

Description: Author(s): Qian Wang, Gang Li, and Qiang Zhao A detailed analysis of the open charm effects on the decays of J / ψ ( ψ ′ )→ V P is presented, where V stands for light vector meson and P for light pseudoscalar meson. These are the channels that the so-called “12% rule” of perturbative QCD (pQCD) is obviously violated. Nevertheless, they are also the cha... [Phys. Rev. D 85, 074015] Published Wed Apr 11, 2012

Description: Background: Gait deficits are important clinical symptoms of Parkinson's disease (PD). However, existing behavioral tests for the detection of motor impairments in rodents with systemic dopamine depletion only measure akinesia and dyskinesia, and data focusing on gait are scarce. We evaluated gait changes in the methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced C57BL/6 murine model of PD by using a computer-assisted CatWalk system. Correlations of gait parameters with tyrosine hydroxylase (TH) protein levels in the substantia nigra (SN) were also investigated. Results: The gait readouts, including the walking duration, variation of walking speed, step cycle, duty cycle, stance, initial dual stance, terminal dual stance, three- and four-point supports, and the base of support between hind limbs was noted to increase significantly one week after MPTP injection. In contrast, values of the stride length, cadence, swing speed, and diagonal dual support decreased substantially following MPTP treatment (p 〈 0.05). All of these changes lasted for three weeks after the last MPTP administration. Except for the stance in the fore limbs and the swing speed in the hind limbs, the gait variability in the PD mice showed a closer correlation with the protein levels of TH in the SN than the walking distances in the conventional open field test. Coordination parameters of the regularity index and step pattern were not affected in mice treated with MPTP. Conclusion: Data of the study suggest that the computer-assisted CatWalk system can provide reliable and objective criteria to stratify gait changes arising from MPTP-induced bilateral lesions in C57/BL6 mice. The extent of gait changes was noted to correlate with the expression of the biomarker for dopaminergic neurons. This novel analytical method may hold promise in the study of disease progression and new drug screening in a murine PD model.

Description: Author(s): Nianbei Li, Jie Ren, Lei Wang, Gang Zhang, Peter Hänggi, and Baowen Li Just as electrons in electronics, lattice vibrations or phonons, i.e., the carriers of heat, can be manipulated to produce useful devices for controlling energy and processing information. This Colloquium reviews, from the experimental and theoretical perspectives, the main issues and challenges in ... [Rev. Mod. Phys. 84, 1045] Published Tue Jul 17, 2012

Description: Journal of Medicinal Chemistry DOI: 10.1021/jm300828h