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

Shape-Controlled Synthesis of ZnS Nanostructures: A Simple and Rapid Method for One-Dimensional Materials by Plasma

In this paper, ZnS one-dimensional (1D) nanostructures including tetrapods, nanorods, nanobelts, and nanoslices were selectively synthesized by using RF thermal plasma in a wall-free way. The feeding rate and the cooling flow rate were the critical experimental parameters for defining the morphology of the final products. The detailed structures of synthesized ZnS nanostructures were studied through transmission electron microscope, X-ray diffraction, and high-resolution transmission electron microscope. A collision-controlled growth mechanism was proposed to explain the growth process that occurred exclusively in the gas current by a flowing way, and the whole process was completed in several seconds. In conclusion, the present synthetic route provides a facile way to synthesize ZnS and other hexagonal-structured 1D nanostructures in a rapid and scalable way

Cooperation of p300 and PCAF in the Control of MicroRNA 200c/141 Transcription and Epithelial Characteristics

Epithelial to mesenchymal transition (EMT) not only occurs during embryonic development and in response to injury, but is an important element in cancer progression. EMT and its reverse process, mesenchymal to epithelial transition (MET) is controlled by a network of transcriptional regulators and can be influenced by posttranscriptional and posttranslational modifications. EMT/MET involves many effectors that can activate and repress these transitions, often yielding a spectrum of cell phenotypes. Recent studies have shown that the miR-200 family and the transcriptional suppressor ZEB1 are important contributors to EMT. Our previous data showed that forced expression of SPRR2a was a powerful inducer of EMT and supports the findings by others that SPRR gene members are highly upregulated during epithelial remodeling in a variety of organs. Here, using SPRR2a cells, we characterize the role of acetyltransferases on the microRNA-200c/141 promoter and their effect on the epithelial/mesenchymal status of the cells. We show that the deacetylase inhibitor TSA as well as P300 and PCAF can cause a shift towards epithelial characteristics in HUCCT-1-SPRR2a cells. We demonstrate that both P300 and PCAF act as cofactors for ZEB1, forming a P300/PCAF/ZEB1 complex on the miR200c/141 promoter. This binding results in lysine acetylation of ZEB1 and a release of ZEB1 suppression on miR-200c/141 transcription. Furthermore, disruption of P300 and PCAF interactions dramatically down regulates miR-200c/141 promoter activity, indicating a PCAF/P300 cooperative function in regulating the transcriptional suppressor/activator role of ZEB1. These data demonstrate a novel mechanism of miRNA regulation in mediating cell phenotype

Proteomic analysis of differential proteins in pancreatic carcinomas: Effects of MBD1 knock-down by stable RNA interference

<p>Abstract</p> <p>Background</p> <p>Methyl-CpG binding domain protein 1 (MBD1), a suppressor of gene transcription, may be involved in inactivation of tumor suppressor genes during tumorigenesis. Over-expression of MBD1 has been reported in human pancreatic carcinomas.</p> <p>Methods</p> <p>In this study, we established a MBD1-knock-down pancreatic cancer cell line (BxPC-3) using stable RNA interference, to compare the proteomic changes between control and MBD1-knock-down cells using two-dimensional gel electrophoresis and mass spectrometry.</p> <p>Results</p> <p>We identified five proteins that were up-regulated and nine proteins that were down-regulated. Most of the identified proteins are involved in tumorigenesis, some are prognostic biomarkers for human malignant tumors.</p> <p>Conclusion</p> <p>Our data suggest that these differential proteins may be associated with the function of MBD1, and provide some insight into the functional mechanism of MBD1 in the development of pancreatic cancer.</p

The role of character positional frequency on Chinese word learning during natural reading

Readers? eye movements were recorded to examine the role of character positional frequency on Chinese lexical acquisition during reading and its possible modulation by word spacing. In Experiment 1, three types of pseudowords were constructed based on each character?s positional frequency, providing congruent, incongruent, and no positional word segmentation information. Each pseudoword was embedded into two sets of sentences, for the learning and the test phases. In the learning phase, half the participants read sentences in word-spaced format, and half in unspaced format. In the test phase, all participants read sentences in unspaced format. The results showed an inhibitory effect of character positional frequency upon the efficiency of word learning when processing incongruent pseudowords both in the learning and test phase, and also showed facilitatory effect of word spacing in the learning phase, but not at test. Most importantly, these two characteristics exerted independent influences on word segmentation. In Experiment 2, three analogous types of pseudowords were created whilst controlling for orthographic neighborhood size. The results of the two experiments were consistent, except that the effect of character positional frequency was absent in the test phase in Experiment 2. We argue that the positional frequency of a word?s constituent characters may influence the character-to-word assignment in a process that likely incorporates both lexical segmentation and identification

High Diversity of the Fungal Community Structure in Naturally-Occurring Ophiocordyceps sinensis

BACKGROUND: Ophiocordyceps sinensis (syn. Cordyceps sinensis), which is a parasite of caterpillars and is endemic to alpine regions on the Tibetan Plateau, is one of the most valuable medicinal fungi in the world. "Natural O. sinensis specimens" harbor various other fungi. Several of these other fungi that have been isolated from natural O. sinensis specimens have similar chemical components and/or pharmaceutical effects as O. sinensis. Nevertheless, the mycobiota of natural O. sinensis specimens has not been investigated in detail. METHODOLOGY/PRINCIPAL FINDINGS: Based on the technique of PCR-single-strand conformation polymorphism (PCR-SSCP), the mycobiota of three different sections (stromata, sclerotia, and mycelial cortices) from natural O. sinensis specimens were investigated using both culture-dependent and -independent methods. For the culture-dependent method, 572 fungal strains were isolated, and 92 putative operational taxonomic units (OTUs) were identified from 226 sequenced strains with the threshold of 97%. For the culture-independent method, 490 fungal clones were identified from about 3000 clones of ITS fragments from the whole-community DNA; based on PCR-SSCP analyses, 266 of these clones were selected to be sequenced, and 118 putative OTUs were detected. The overwhelming majority of isolates/clones and OTUs were detected from mycelial cortices; only a few were detected from stromata and sclerotia. The most common OTUs detected with both methods belonged to Ascomycota; however, only 13 OTUs were detected simultaneously by both methods. Potential novel lineages were detected by each of the two methods. CONCLUSIONS/SIGNIFICANCE: A great number of fungal species present in the mycobiota of naturally-occurring O. sinensis specimens were detected, and many of them may represent undescribed lineages. That only a few of the same OTUs were detected by both methods indicated that different methods should be used. This study increased our understanding about the fungal community structure of this valuable medicinal herb