Crossbows and imperial craft organisation: the bronze triggers of China’s Terracotta Army

The Terracotta Army that protected the tomb of the Chinese emperor Qin Shihuang offers an evocative image of the power and organisation of the Qin armies who unified China through conquest in the third century BC. It also provides evidence for the craft production and administrative control that underpinned the Qin state. Bronze trigger mechanisms are all that remain of crossbows that once equipped certain kinds of warrior in the Terracotta Army. A metrical and spatial analysis of these triggers reveals that they were produced in batches and that these separate batches were thereafter possibly stored in an arsenal, but eventually were transported to the mausoleum to equip groups of terracotta crossbowmen in individual sectors of Pit 1. The trigger evidence for large-scale and highly organised production parallels that also documented for the manufacture of the bronze-tipped arrows and proposed for the terracotta figures themselves

The radial dimension of a supersonic jet expansion from conical nozzle

In a laser-cluster interaction experiment, the radial dimension of a supersonic gas jet is an important parameter for the characterization of interaction volume. It is noted that due to the lateral gas expansion, the diameter of a supersonic gas jet is larger than the idealized diameter of a gas jet from a conical nozzle. In this work the effect of the lateral expansion on the radial dimension of gas jet was investigated by simulations. Based on the simulation results, the diameter of gas jet l was compared in detail with the corresponding diameter l(T) in the idealized straight streamline model and the diameter l(H) at a half of maximum atom density of gas jet. The results reveal how the deviation of l from l(T) (l(H)) changes with respect to the opening angles of conical nozzles, the heights above the nozzle, the nozzle lengths and the gas backing pressures. It is found that the diameter of gas jet l is close to the idealized diameter l(T) and l(H) in the case where a long conical nozzle with a large opening angle is used under a low gas backing pressure. In this case, the effect of the lateral expansion is so weak that the edge of gas jet becomes sharp and the radial distribution of atom density in gas jet tends to be uniform. The results could be useful for the characterization of a supersonic gas jet. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).110Ysciescopu

Preparation and analysis of a new bioorganic metallic material

Biofouling on metal surfaces is one of the main reasons for increased ship drag. Many methods have already been used to reduce or remove it with moderate success. In this study, a synthetic peptide has been utilized to react with 304 stainless steel aiming to generate a bioorganic stainless steel using a facile technique. After the reaction, white matter was found on the surface of the treated stainless steel via SEM, whilst the nontreated stainless steel had none. Elemental analysis confirmed that excessive N existed on the surface of the treated samples using an integrated SEM-EDS instrument, implying the presence of peptides binding on the surface of the bioorganic stainless steel. The FTIR spectra showed amide A and II peaks on the surface of the bioorganic stainless steel suggesting that either the peptides grafted onto the steel surface or the polypeptide composition accumulated on the steel samples. XPS analysis of the treated steel demonstrated that there was nitrogen bonding on the surface and it was a chemical bond via a previously unreported chemical interaction. The treated steel has a markedly increased contact angle (water contact angle of 65.7 ± 4.7° for nontreated steel in comparison to treated, 96.4 ± 2.1°), which supported the observation of the wettability change of the surface, i.e. the decrease of the surface energy value after peptide treatment. The changes of the surface parameters (such as, Sa, Sq, Ssk and Sku) of the treated steel by surface analysis were observed

Allogeneic hematopoietic stem cell transplantation in China: where we are and where to go

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective and sometimes the only curative therapy for patients with certain hematological diseases. Allo-HSCT has been practiced in China for approximately 30 years, and great improvements have been made within the past decade, particularly in fields such as the haploidentical HSCT system, strategies to overcome relapse and GVHD, and modified HSCT for elderly patients. This review will describe the current situation and provide a prospective of these unique aspects of Allo-HSCT in China

The De Novo Cytosine Methyltransferase DRM2 Requires Intact UBA Domains and a Catalytically Mutated Paralog DRM3 during RNA–Directed DNA Methylation in Arabidopsis thaliana

Eukaryotic DNA cytosine methylation can be used to transcriptionally silence repetitive sequences, including transposons and retroviruses. This silencing is stable between cell generations as cytosine methylation is maintained epigenetically through DNA replication. The Arabidopsis thaliana Dnmt3 cytosine methyltransferase ortholog DOMAINS REARRANGED METHYLTRANSFERASE2 (DRM2) is required for establishment of small interfering RNA (siRNA) directed DNA methylation. In mammals PIWI proteins and piRNA act in a convergently evolved RNA–directed DNA methylation system that is required to repress transposon expression in the germ line. De novo methylation may also be independent of RNA interference and small RNAs, as in Neurospora crassa. Here we identify a clade of catalytically mutated DRM2 paralogs in flowering plant genomes, which in A.thaliana we term DOMAINS REARRANGED METHYLTRANSFERASE3 (DRM3). Despite being catalytically mutated, DRM3 is required for normal maintenance of non-CG DNA methylation, establishment of RNA–directed DNA methylation triggered by repeat sequences and accumulation of repeat-associated small RNAs. Although the mammalian catalytically inactive Dnmt3L paralogs act in an analogous manner, phylogenetic analysis indicates that the DRM and Dnmt3 protein families diverged independently in plants and animals. We also show by site-directed mutagenesis that both the DRM2 N-terminal UBA domains and C-terminal methyltransferase domain are required for normal RNA–directed DNA methylation, supporting an essential targeting function for the UBA domains. These results suggest that plant and mammalian RNA–directed DNA methylation systems consist of a combination of ancestral and convergent features

A Dual Inhibitory Mechanism Sufficient to Maintain Cell-Cycle-Restricted CENP-A Assembly

Chromatin featuring the H3 variant CENP-A at the centromere is critical for its mitotic function and epigenetic maintenance. Assembly of centromeric chromatin is restricted to G1 phase through inhibitory action of Cdk1/2 kinases in other phases of the cell cycle. Here, we identify the two key targets sufficient to maintain cell-cycle control of CENP-A assembly. We uncovered a single phosphorylation site in the licensing factor M18BP1 and a cyclin A binding site in the CENP-A chaperone, HJURP, that mediated specific inhibitory phosphorylation. Simultaneous expression of mutant proteins lacking these residues results in complete uncoupling from the cell cycle. Consequently, CENP-A assembly is fully recapitulated under high Cdk activities, indistinguishable from G1 assembly. We find that Cdk-mediated inhibition is exerted by sequestering active factors away from the centromere. Finally, we show that displacement of M18BP1 from the centromere is critical for the assembly mechanism of CENP-A

Synthesis and Application of Carbon–Iron Oxide Microspheres’ Black Pigments in Electrophoretic Displays

Carbon–iron oxide microspheres’ black pigments (CIOMBs) had been prepared via ultrasonic spray pyrolysis of aqueous solutions containing ferrous chloride and glucose. Due to the presence of carbon, CIOMBs not only exhibited remarkably acid resistance, but also could be well dispersed in both polar solvents and nonpolar solvent. Finally, dispersions of hollow CIOMBs in tetrachloroethylene had successfully been applied in electrophoretic displays

Analysis of the Constituents in Rat Serum after Oral Administration of Fufang Zhenzhu Tiaozhi Capsule by UPLC–Q–TOF–MS/MS

A rapid and sensitive UPLC/Q–TOF–MS method has been established for analysis of the constituents in rat serum after oral administration of Fufang Zhenzhu Tiaozhi (FTZ) capsule, an effective compound prescription for treating hyperlipidemia in the clinic. The UPLC/MS information of samples was obtained first in FTZ preparation and FTZ-treated rat serum. Mass spectra were acquired in both negative and positive ion modes. Thirty-six constituents in rat serum after oral administration of FTZ were detected, including the alkaloids, ginsenosides, pentacyclic triterpenes, and their metabolites. These chemicals were identified based on the retention time and mass spectrometry data with those of authentic standards or comparison of the literatures reports. Twenty-seven prototype components originated from FTZ and nine were the metabolites of the FTZ constituents. These results shed light on the potential active constituents of the complex traditional Chinese medicinal formulas

BioSunMS: a plug-in-based software for the management of patients information and the analysis of peptide profiles from mass spectrometry

<p>Abstract</p> <p>Background</p> <p>With wide applications of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS), statistical comparison of serum peptide profiles and management of patients information play an important role in clinical studies, such as early diagnosis, personalized medicine and biomarker discovery. However, current available software tools mainly focused on data analysis rather than providing a flexible platform for both the management of patients information and mass spectrometry (MS) data analysis.</p> <p>Results</p> <p>Here we presented a plug-in-based software, BioSunMS, for both the management of patients information and serum peptide profiles-based statistical analysis. By integrating all functions into a user-friendly desktop application, BioSunMS provided a comprehensive solution for clinical researchers without any knowledge in programming, as well as a plug-in architecture platform with the possibility for developers to add or modify functions without need to recompile the entire application.</p> <p>Conclusion</p> <p>BioSunMS provides a plug-in-based solution for managing, analyzing, and sharing high volumes of MALDI-TOF or SELDI-TOF MS data. The software is freely distributed under GNU General Public License (GPL) and can be downloaded from <url>http://sourceforge.net/projects/biosunms/</url>.</p