[Preparation and Performance Evaluation of Polyacrylamide Hydrogel Coating on the Surface of Silicone Rubber Nasogastric Tube].

Objective: To prepare the hydrogel coating on the surfaces of nasogastric tubes and to evaluate its effect on the insertion of nasogastric tubes in a rabbit model. Methods: The polyacrylamide (PAAm) hydrogel coating was prepared by UV-induced free radical polymerization. The morphology of the PAAm coating and its interfacial bonding with the silicone rubber substrates of nasogastric tubes were observed with scanning electron microscope. The composition of the coating was analyzed by Fourier transform infrared (FTIR) spectrometer and X-ray photoelectron spectrometer (XPS). The water absorption power and stability of the coating were measured by the weighing method. Water contact angle meter was used to measure the wettability of the coating and tribometer was used to determine the friction coefficient of the silicone rubber substrates before and after the modification. The cytotoxicity of the coating on L929 murine fibroblast cell line was explored with CCK-8 assay after 24-h coculturing of the L929 cell line with silicone rubber substrates before and after modification. An animal model of nasogastric tube insertion in New Zealand rabbits was used to evaluate the effect of the lubrication coating by assessing the insertion time and nasal damage. Results: In this study, PAAm hydrogel coating was prepared and constructed on the surface of silicone rubber nasogastric tubes. The coating, with a three-dimensional network structure, showed strong interfacial bonding with silicone rubber substrates. The appearance of amino and carbonyl groups indicated that the PAAm hydrogel coating was grafted on the surfaces of nasogastric tubes. Before the modification, the silicone rubber substrate essentially did not absorb much water, whereas, after the modification, the silicone rubber substrate showed significant improvement of as much as 2.9% in water absorption. After sonication for 90 min, the weight loss rate was only 0.15%. Compared with pristine nasogastric tubes, the water contact angle of the modified nasogastric tubes was reduced from 111.9°±2.2° to 58.9°±1.5° ( t=22.59, P<0.05). In addition, the friction coefficient of silicone rubber nasogastric tubes decreased by 69.3% from 0.378±0.05 to 0.116±0.004 ( t=42.80, P<0.05) after modification. Moreover, there was no significant difference in the cytocompatibility between L929 cells cocultured with pristine nasogastric tube and those cocultured with modified nasogastric tube. The animal experiment of nasogastric tube insertion showed that the insertion time of the modified nasogastric tubes was reduced from (41.6±7.8) s to (12.4±2.9) s ( t=8.509, P<0.05). Laryngoscopy revealed that the PAAm hydrogel coating significantly reduced the mucosal damage caused by the insertion of nasogastric tubes. Conclusion: In this study, PAAm hydrogel coating with strong interfacial bonding was prepared on the surface of silicone rubber nasogastric tubes. The coating has excellent hydrophilic lubrication property and cytocompatibility, effectively shortens the insertion time, and reduces the damage caused by nasogastric tube insertion.

The leaf polarity factors SGS3 and YABBYs regulate style elongation through auxin signaling in Mimulus lewisii.

Style length is a major determinant of breeding strategies in flowering plants and can vary dramatically between and within species. However, little is known about the genetic and developmental control of style elongation. We characterized the role of two classes of leaf adaxial-abaxial polarity factors, SUPPRESSOR OF GENE SILENCING3 (SGS3) and the YABBY family transcription factors, in the regulation of style elongation in Mimulus lewisii. We also examined the spatiotemporal patterns of auxin response during style development. Loss of SGS3 function led to reduced style length via limiting cell division, and downregulation of YABBY genes by RNA interference resulted in shorter styles by decreasing both cell division and cell elongation. We discovered an auxin response minimum between the stigma and ovary during the early stages of pistil development that marks style differentiation. Subsequent redistribution of auxin response to this region was correlated with style elongation. Auxin response was substantially altered when both SGS3 and YABBY functions were disrupted. We suggest that auxin signaling plays a central role in style elongation and that the way in which auxin signaling controls the different cell division and elongation patterns underpinning natural style length variation is a major question for future research.

Source Symbol Purging-Based Distributed Conditional Arithmetic Coding.

A distributed arithmetic coding algorithm based on source symbol purging and using the context model is proposed to solve the asymmetric Slepian-Wolf problem. The proposed scheme is to make better use of both the correlation between adjacent symbols in the source sequence and the correlation between the corresponding symbols of the source and the side information sequences to improve the coding performance of the source. Since the encoder purges a part of symbols from the source sequence, a shorter codeword length can be obtained. Those purged symbols are still used as the context of the subsequent symbols to be encoded. An improved calculation method for the posterior probability is also proposed based on the purging feature, such that the decoder can utilize the correlation within the source sequence to improve the decoding performance. In addition, this scheme achieves better error performance at the decoder by adding a forbidden symbol in the encoding process. The simulation results show that the encoding complexity and the minimum code rate required for lossless decoding are lower than that of the traditional distributed arithmetic coding. When the internal correlation strength of the source is strong, compared with other DSC schemes, the proposed scheme exhibits a better decoding performance under the same code rate.

[Application of high resolution melting curve to identification of Cimicifugae Rhizoma].

High-resolution-melting analysis (HRM) is a new technology derived from q PCR and is widely used in the study of polymorphism, genotyping, and single nucleotide mutation. Advantages of HRM include cost-effectiveness and time-efficiency over PCR-based genotyping. However, the application of HRM in the authentication of herbal products is still limited with few studies on the classification and identification of herbal products. In this study, Cimicifugae Rhizoma was used as an example to verify the stability and accuracy of HRM technique in identification of Chinese materia medica. HRM assay was established for identification based on ITS2 region of Cimicifugae Rhizomas and its adulterants(including 41 samples). Our findings showed that HRM allows not only the identification of adulteration but also the quantification of the most common admixture. This study is significant for better quality in the verification of the authenticity of herbal medicine. The method is promising for future identification of traditional Chinese medicinal materials.

BLADE-ON-PETIOLE interacts with CYCLOIDEA to fine-tune CYCLOIDEA-mediated flower symmetry in monkeyflowers (Mimulus).

Morphological novelties, or key innovations, are instrumental to the diversification of the organisms. In plants, one such innovation is the evolution of zygomorphic flowers, which is thought to promote outcrossing and increase flower morphological diversity. We isolated three allelic mutants from two Mimulus species displaying altered floral symmetry and identified the causal gene as the ortholog of Arabidopsis BLADE-ON-PETIOLE. We found that MlBOP and MlCYC2A physically interact and this BOP-CYC interaction module is highly conserved across the angiosperms. Furthermore, MlBOP self-ubiquitinates and suppresses MlCYC2A self-activation. MlCYC2A, in turn, impedes MlBOP ubiquitination. Thus, this molecular tug-of-war between MlBOP and MlCYC2A fine-tunes the expression of MlCYC2A, contributing to the formation of bilateral symmetry in flowers, a key trait in angiosperm evolution.

Facile synthesis of gold nanoflowers with high surface-enhanced Raman scattering activity.

Highly branched gold nanoflowers are synthesized in high yield by a simple amino-reducing method, without additional seeds or surfactant agents. We present a systematic investigation of the influence of different parameters on the size, morphology, and monodispersity of gold nanoflowers. The initial concentration of reducing agent, the solvent viscosity, and the reaction temperature play critical roles in the formation of nanoparticles. A lower concentration of reducing agent causes larger particles with sharp and dendritic tips. Moreover, with increasing solvent viscosity, the obtained particles have more and larger tips. Examination of the nanoparticles at different reaction stages with transmission electron microscopy and UV-vis spectroscopy reveals the formation of the gold nanoflowers as a classical growth process in which diffusion-controlled growth gives rise to the highly branched structures. Additionally, these gold nanoflowers have prospects for surface-enhanced Raman scattering (SERS) imaging because of their strong SERS enhancement and clean surface.

Porous biomimetic membranes: fabrication, properties and future applications.

A cell membrane is a flexible lipid bilayer with sophisticated functions which dominate the exchange of material, energy and information between the outside and the inside of the cell. In order to understand and imitate these structures and functions, scientists had already developed a variety of mimic membranes which are alike in form based on lipid bilayer and organic channel-molecules. With the rise of nanotechnology, a large number of synthetic nano-devices are widely used to construct porous biomimetic membranes which are alike in spirit instead of the conventional lipid bilayer membranes. This perspective will first introduce several typical methods to fabricate porous biomimetic membranes, and then discuss the "smart" properties and future applications of these membranes in materials transport, energy transformation and signal transduction aspects.

The complete chloroplast genome of Keteleeria davidiana var. calcarea (Pinaceae), an endangered species endemic to China.

Keteleeria davidiana var. calcarea is an endangered tree with considerable economic potential that used as timber wood for furniture and house construction. However, the natural population of K. davidiana var. calcarea is very fragmented, which is the cause for its low genetic diversity. In this study, we report the complete chloroplast genome of K. davidiana var. calcarea using Illumina sequencing. The chloroplast genome size is 117,670 bp in length, harboring a pair of very short inverted repeats (IRs) of 262 bp separated by a large single copy (LSC) sequence of 64,634 bp and a small single copy (SSC) sequence of 53,078 bp. The chloroplast genome K. davidiana var. calcarea contains 113 genes (74 protein genes, 35 tRNA genes, and 4 rRNA genes) and the overall GC content is 38.6%. The maximum likelihood phylogenetic analysis shows that K. davidiana var. calcarea is clustered with K. davidiana in genus Keteleeria. This complete chloroplast genome will help us to understand the evolution of K. davidiana var. calcarea and lays the foundations for future studies in this species conservation.

The complete chloroplast genome of Euphorbia hirta (Euphorbiaceae), a commonly used medicinal plant in China.

Plants in the genus Euphorbia have been widely used as herbal medicine, and for ornamental horticulture and biofuel production. In this study, we report the complete chloroplast genome of Euphorbia hirta which is known as the 'asthma-plant' due to its medicinal use. The chloroplast genome of this species is 164,340 bp in length, including a pair of inverted repeat regions (IRs) (27,354 bp) that are divided by a large single-copy region (LSC) (91,373 bp) and a small single-copy region (SSC) (18,259 bp). The chloroplast genome of E. hirta contains 111 unique genes (77 protein-coding, 30 tRNA, and four rRNA), 19 of which are duplicated in the IR regions. The overall GC content is 35.4%. Phylogenetic analysis fully resolved E. hirta groups with other species of Euphorbia. The complete chloroplast genome of E. hirta provides useful information that can be used to distinguish related species and reconstruct evolutionary relationships.

Artificial, switchable K+-gated ion channels based on flow-through titania-nanotube arrays.

In the present work, we demonstrated a novel type of artificial K(+)-gated ion channels based on titania nanotubes loaded with Au nanoparticles and G-rich DNA composite structure. K(+) promoted conformational change of G-rich DNA from flexible chain to rigid quadruplex, which provided a blocking effect for the transport of anions such as Fe(CN)(6)(4-) and other molecules through the channels in TiO(2) nanotubes. This fabricated permselective membrane using K(+) as a trigger may set light to the field of biosensing, drug-release, ion exchange membrane and so on.

Species Quantification in Complex Herbal Formulas-Vector Control Quantitative Analysis as a New Method.

Product mislabeling and/or species fraud in Traditional Chinese Medicine (TCM) not only decrease TCM quality, but also pose a potential health issue to the end user. Up to now, methods to control TCM quality have been developed to detect specific metabolites or identify the original species. However, species quantification in complex herbal formulas is rarely concerned. Here, we reported a simple Vector Control Quantitative Analysis (VCQA) method for flexible and accurate multiplex species quantification in traditional Chinese herbal formulas. We developed PCR-based strategy to quickly generate the integrated DNA fragments from multiple targeted species, which can be assembled into the quantitative vector in one round of cloning by Golden Gate ligation and Gateway recombination technique. With this method, we recruited the nuclear ribosomal DNA Internal Transcribed Spacer (ITS) region for the quantification of Ligusticum sinense "Chuanxiong," Angelica dahurica (Hoffm.) Benth. & Hook.f. ex Franch. & Sav., Notopterygium incisum K. C. Ting ex H. T. Chang, Asarum sieboldii Miq., Saposhnikovia divaricata (Turcz.) Schischk., Nepeta cataria L., Mentha canadensis L., and Glycyrrhiza uralensis Fisch. ex DC. in ChuanXiong ChaTiao Wan, a classic Chinese herbal formula with very long historical background. We found that, firstly, VCQA method could eliminate the factors affecting such as the variations in DNA extracts when in combination with the use of universal and species-specific primers. Secondly, this method detected the limit of quantification of A. sieboldii Miq. in formula products down to 1%. Thirdly, the stability of quality of ChuanXiong ChaTiao Wan formula varies significantly among different manufacturers. In conclusion, VCQA method has the potential power and can be used as an alternative method for species quantification of complex TCM formulas.

Two MYB Proteins in a Self-Organizing Activator-Inhibitor System Produce Spotted Pigmentation Patterns.

Many organisms exhibit visually striking spotted or striped pigmentation patterns. Developmental models predict that such spatial patterns can form when a local autocatalytic feedback loop and a long-range inhibitory feedback loop interact. At its simplest, this self-organizing network only requires one self-activating activator that also activates a repressor, which inhibits the activator and diffuses to neighboring cells. However, the molecular activators and inhibitors fully fitting this versatile model remain elusive in pigmentation systems. Here, we characterize an R2R3-MYB activator and an R3-MYB repressor in monkeyflowers (Mimulus). Through experimental perturbation and mathematical modeling, we demonstrate that the properties of these two proteins correspond to an activator-inhibitor pair in a two-component, reaction-diffusion system, explaining the formation of dispersed anthocyanin spots in monkeyflower petals. Notably, disrupting this pattern impacts pollinator visitation. Thus, subtle changes in simple activator-inhibitor systems are likely essential contributors to the evolution of the remarkable diversity of pigmentation patterns in flowers.

High frequency plant regeneration from leaf culture of Neolamarckia cadamba.

Neolamarckia cadamba is a miracle tree species with considerable economic potential uses as a timber wood, woody forage and traditional medicine resource. The present study aimed to establish a highly efficient and robust protocol of plant regeneration for N. cadamba. Greenish callus was induced from very young leaf explants of sterile in vitro plantlets cultured on Murashige and Skoog's (MS) medium supplemented with 3 mg l-1 thidiazuron (TDZ), 0.1 mg l-1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.05 mg l-1 α-naphthaleneacetic acid (NAA). The callus could differentiate into nodular embryogenic structures or adventitious shoots, and these two regeneration pathways often occurred in the same callus clumps. The micro-shoots developed roots in MS supplemented with 0.05 mg l-1 NAA and 0.05 mg l-1 indole-3-butyric acid (IBA), while the nodular embryogenic structures germinated directly and developed into plantlets on induction medium contained with 0.5 mg l-1 (or 1 mg l-1) 6-benzyladenine (6-BA) and 0.05 mg l-1 NAA. The rooted plantlets could be successfully acclimatized to a greenhouse with more than 92.0% survival. This regeneration protocol can be used in large scale cultivation needs and may be useful for future genetic modifications of N. cadamba.

Genome-wide Analysis of the WRKY Gene Family and its Response to Abiotic Stress in Buckwheat (Fagopyrum Tataricum).

The WRKY gene family is an ancient plant transcription factor (TF) family with a vital role in plant growth and development, especially in response to biotic and abiotic stresses. Although many researchers have studied WRKY TFs in numerous plant species, little is known of them in Tartary buckwheat (Fagopyrum tataricum). Based on the recently reported genome sequence of Tartary buckwheat, we identified 78 FtWRKY proteins that could be classified into three major groups. All 77 WRKY genes were distributed unevenly across all eight chromosomes. Exon-intron analysis and motif composition prediction revealed the complexity and diversity of FtWRKYs, indicating that WRKY TFs may be of significance in plant growth regulation and stress response. Two separate pairs of tandem duplication genes were found, but no segmental duplications were identified. Overall, most orthologous gene-pairs between Tartary and common buckwheat evolved under strong purifying selection. qRT-PCR was used to analyze differences in expression among four FtWRKYs (FtWRKY6, 74, 31, and 7) under salt, drought, cold, and heat treatments. The results revealed that all four proteins are related to abiotic stress responses, although they exhibited various expression patterns. In particular, the relative expression levels of FtWRKY6, 74, and 31 were significantly upregulated under salt stress, while the highest expression of FtWRKY7 was observed from heat treatment. This study provides comprehensive insights into the WRKY gene family in Tartary buckwheat, and can support the screening of additional candidate genes for further functional characterization of WRKYs under various stresses.

DNA barcoding based identification of Hippophae species and authentication of commercial products by high resolution melting analysis.

Sea buckthorn (Hippophae), an ancient crop with modern virtues, is increasingly consumed in source of foods and nutraceuticals. The growing demand leads to the adulteration of commercial sea buckthorn products, which is a common form of food fraud. Herein, a high resolution melting assay, targeting a DNA barcoding region of the internal transcribed spacer 2 (ITS2) (Bar-HRM) was developed to identify the seven native Chinese Hippophae species, and to authenticate commercial sea buckthorn products. Melting data from the HRM assay demonstrated that all Hippophae species could be clearly distinguished. Then, application to commercial sea buckthorn products indicated the existence of adulterants or contamination, further confirmed using Sanger sequencing results for PCR products from HRM. The Bar-HRM technique proposed in this work could provide a method for regulatory agencies, promoting consumers trust, and raise the quality and safety of sea buckthorn products.

Development of an efficient regeneration system for the precious and fast-growing timber tree Toona ciliata.

Toona ciliata (Chinese mahogany) is an important timber species and secondary protected plant due to excessive exploitation in China. Here we developed a robust and efficient regeneration system for adventitious shoot induction using hypocotyl explants of T. ciliata. To facilitate plant growth, different regulators were added to Murashige-Skoog (MS) medium (0.5 mg/l 6-BA, 1.0 mg/l KT and 0.1 mg/l IBA). A regeneration frequency of 58.67% with four shoots per explant was achieved by horizontal setting of hypocotyls on MS medium and following a 20-day seeding period. MS medium supplemented with 0.3 mg/l 6-BA and 0.2 mg/l NAA was optimal for shoot multiplication and elongation, with a multiplication coefficient of 3.06. A rooting frequency of 93.33% was achieved using the half-strength MS containing 0.1 mg/l NAA. After acclimatization, plantlets were transplanted to sterilized nutrient soil containing a 2 : 1 ratio of vermiculate with 90% survival frequency. Thus, the regeneration system developed in this study would be useful for genetic transformation and other biotechnology endeavours in T. ciliata.

Using SSR-HRM to Identify Closely Related Species in Herbal Medicine Products: A Case Study on Licorice.

Traditional herbal medicines have played important roles in the ways of life of people around the world since ancient times. Despite the advanced medical technology of the modern world, herbal medicines are still used as popular alternatives to synthetic drugs. Due to the increasing demand for herbal medicines, plant species identification has become an important tool to prevent substitution and adulteration. Here we propose a method for biological assessment of the quality of prescribed species in the Chinese Pharmacopoeia by use of high resolution melting (HRM) analysis of microsatellite loci. We tested this method on licorice, a traditional herbal medicine with a long history. Results showed that nine simple sequence repeat (SSR) markers produced distinct melting curve profiles for the five licorice species investigated using HRM analysis. These results were validated by capillary electrophoresis. We applied this protocol to commercially available licorice products, thus enabling the consistent identification of 11 labels with non-declared Glycyrrhiza species. This novel strategy may thus facilitate DNA barcoding as a method of identification of closely related species in herbal medicine products. Based on this study, a brief operating procedure for using the SSR-HRM protocol for herbal authentication is provided.

Bioactivity of diatomaceous earth against the subterranean termite Reticulitermes chinensis Snyder (Isoptera: Rhinotermitidae).

The effects of diatomaceous earth (DE) on the penetrating behavior, tunneling behavior, mortality, and body surface characteristics of the subterranean termite Reticulitermes chinensis were investigated in this study. Our results show that the workers of R. chinensis were able to penetrate 1- and 2-mm layers of dry DE but not 3-mm layers. After treatment with dry DE for 6 h, the mortality of termites reached 100%, which was significantly higher than in the treatment with DE with a 10 and 25% moisture content and treatment with sand of three different moisture contents. The tunneling distances of workers in DE with 10, 25, and 50% moisture contents were all significantly shorter than those in sand with the same moisture contents (10, 25, and 50%), indicating that DE has a good suppressing effect on the tunneling behavior of workers. After treatment with dry DE for different times (1, 3, and 6 h), many DE particles adhered to the bodies of workers, whereas no particles adhered to the body of workers in the case of treatment with dry sand. The treatment with dry DE for 6 h resulted in the death of all workers, which presented conspicuous abdominal shrinkage, whereas workers treated with sand had no significant mortality and no obvious abdominal shrinkage. In summary, we suggest that dry DE has ideal insecticidal activity against the subterranean termite R. chinensis and can be further exploited for controlling termites inside houses.

Identifying the Species of Seeds in Traditional Chinese Medicine Using DNA Barcoding.

Seed is not only the main reproductive organ of most of herbal plants but also an important part of Traditional Chinese Medicine (TCM). Seed TCMs possess important medicinal properties and have been widely used as components of pharmaceutical products. In parallel with the increasing popularity and accessibility of seeds as medicinal products in recent years, numerous substitutes and adulterants have also appeared on the market. Due to the small volume and similar appearances of many seed TCMs, they are very difficult to accurately identify the constituent plant species through organoleptic methods. Usage of the wrong herb may be ineffective or may worsen the condition and even cause death. Correct identification of seed herbal medicines is therefore essential for their safe use. Here, we acquired 177 ITS2 sequences and 15 psbA-trnH sequences from 51 kinds of seed TCMs belonging to 64 species that have been described in the Chinese Pharmacopoeia. Tree-building analysis showed that the ITS2 sequences of 48 seed TCMs can be differentiated from each other, and they formed distinct, non-overlapping groups in the maximum-likelihood tree. Furthermore, all of the sequences acquired in this study have been submitted to the public DNA barcoding system for herbal medicine, and this integrated database was used to identify 400 seed TCM samples purchased from medicinal markets, drug stores, and the Internet, enabling the identification of 7.5% of the samples as containing non-declared species. This study provides a brief operating procedure for the identification of seed TCMs found in herbal medicine. In the future, researchers and traditional herbal medicine enterprises can use this system to test their herbal materials.

Metabolic discrimination of sea buckthorn from different Hippophaë species by 1H NMR based metabolomics.

Sea buckthorn (Hippophaë; Elaeagnaceae) berries are widely consumed in traditional folk medicines, nutraceuticals, and as a source of food. The growing demand of sea buckthorn berries and morphological similarity of Hippophaë species leads to confusions, which might cause misidentification of plants used in natural products. Detailed information and comparison of the complete set of metabolites of different Hippophaë species are critical for their objective identification and quality control. Herein, the variation among seven species and seven subspecies of Hippophaë was studied using proton nuclear magnetic resonance (1H NMR) metabolomics combined with multivariate data analysis, and the important metabolites were quantified by quantitative 1H NMR (qNMR) method. The results showed that different Hippophaë species can be clearly discriminated and the important interspecific discriminators, including organic acids, L-quebrachitol, and carbohydrates were identified. Statistical differences were found among most of the Hippophaë species and subspecies at the content levels of the aforementioned interspecific discriminators via qNMR and one-way analysis of variance (ANOVA) test. These findings demonstrated that 1H NMR-based metabolomics is an applicable and effective approach for simultaneous metabolic profiling, species differentiation and quality assessment.