Diaporaustalides A-L, Austalide Meroterpenoids from a Plant Endophytic Diaporthe sp.

Twelve new austalide meroterpenoids (1-12) were isolated from the endophytic fungus Diaporthe sp. XC1211. Their structures were elucidated by extensive spectroscopic analysis. The absolute configurations of compounds 1, 3, 4, and 6 were established by single-crystal X-ray diffraction, whereas those for the others were established by experimental electronic circular dichroism (ECD) data analysis. Compounds 1-12 represent a rare class of austalides with a 24α-CH3. Compounds 2 and 5 demonstrated potent proliferation inhibitory effects against LPS-induced B cells with IC50 values of 6.7 (SI = 3.6) and 3.8 (SI > 13) µM, respectively. Compounds 2 and 5 decreased the secretion of IL-6 in LPS-induced B cells in a dose-dependent manner.

Purification and characteristics of a novel milk-clotting metalloprotease from Bacillus velezensis DB219.

Milk-clotting enzyme (MCE) is the essential active agents in dairy processing. The traditional MCE is mainly obtained from animal sources, in which calf rennet is the most widely used in cheese industry. Traditional MCE substitute is becoming necessary due to its limited production and increased cheese consumption. A novel traditional MCE substitute was produced from Bacillus velezensis DB219 in this study. The DB219 MCE exhibited a notable specific activity of 6,110 Soxhlet units/mg and 3.16-fold purification yield with 28.87% recovery through ammonium sulfate fractionation and DEAE-Sepharose Fast Flow. The purified DB219 MCE was a metalloprotease with a molecular weight of 36 kDa. The DB219 MCE was weak acid resistance and stable at pH 6.0 to 10.0 and temperature <45°C. The highest milk-clotting activity was observed in substrate at pH 5.5 added with 20 to 30 mM CaCl2. The Michaelis constant and maximal velocity for casein were 0.31 g/L and 14.22 µmol/min. The DB219 MCE preferred to hydrolyze ß-casein instead of α-casein. The DB219 MCE hydrolyzed α-casein, ß-casein, and κ-casein to generate significantly different peptides in comparison with calf rennet and ES6023 MCE (fungal MCE) through SDS-PAGE and reversed-phase HPLC analysis. The DB219 MCE mainly cleaved Thr124-Ile125 and Ser104-Phe105 bonds in κ-casein and had unique casein cleavage sites and peptide composition through LC-MS/MS analysis. The DB219 MCE was potential to be a new milk coagulant and enriched kinds of traditional MCE substitute.

Nocardia panacis sp. nov., a novel actinomycete with antiphytopathogen activity isolated from the rhizosphere of Panax notoginseng.

Strain YIM PH21724T was isolated from the rhizosphere of Panax notoginseng. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain exhibits close phylogenetic relatedness to Nocardia kroppenstedtii N1286T (97.70%), Nocardia farcinica NCTC 11134T (97.67%) and Nocardia puris DSM 44599T (97.40%). The menaquinones were identified as MK-9 (H4), MK-8 (H4, ω-cyclo) and MK-8 (H4), and the major fatty acids (> 10%) were identified as C16:0, C18:1 ω9c and C18:0 10-methyl. The polar lipids were found to be composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and an unidentified lipid. The G + C content of the genomic DNA was determined to be 67.01 mol%. The phenotypic, chemotaxonomic, phylogenetic and genomic results clearly show strain YIM PH21724T should be classified in the genus Nocardia and represents a novel species, for which the name Nocardia panacis sp. nov. is proposed. The type strain is YIM PH21724T (= DSM 105904T = KCTC 49030T = CCTCC AA 2017043T).

Amycolatopsis panacis sp. nov., isolated from Panax notoginseng rhizospheric soil.

A novel Gram-positive bacterium, designated strain YIM PH21725T, was isolated from a sample of rhizospheric soil of Panaxnotoginseng cultivated in Anning, Yunnan. The strain contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The main fatty acids identified were C17 : 0, iso-C15 : 0, iso-C16 : 0 and C16 : 0. The main menaquinone was MK-9 (H4). The polar lipids included phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phospholipids and phospholipids of an unidentified structure containing glucosamine. The G+C content of genomic DNA was 69.43 mol%. On the basis of its 16S rRNA gene sequence, strain YIM PH21725T should belong to the genus Amycolatopsis, and was closely related to Amycolatopsis sulphurea DSM 46092T (98.57 %), Amycolatopsis jejuensis JCM13280T (97.27 %), Amycolatopsis jiangsuensis KCTC 19885T (96.88 %) and Amycolatopsis ultiminotia JCM 16989T (96.8 %). The phenotypic, chemotaxonomic, phylogenetic and digital DNA-DNA hybridization results clearly indicated that strain YIM PH21725T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsispanacis sp. nov. is proposed. The type strain is YIM PH21725T (=CCTCC AA 2017044T=KCTC 49031T=DSM 105902T).

Whole-Cell Pseudomonas aeruginosa Localized Surface Plasmon Resonance Aptasensor.

The detection of whole-cell Pseudomonas aeruginosa presents an intriguing challenge with direct applications in health care and the prevention of nosocomial infection. To address this problem, a localized surface plasmon resonance (LSPR) based sensing platform was developed to detect whole-cell Pseudomonas aeruginosa strain PAO1 using a surface-confined aptamer as an affinity reagent. Nanosphere lithography (NSL) was used to fabricate a sensor surface containing a hexagonal array of Au nanotriangles. The sensor surface was subsequently modified with biotinylated polyethylene glycol (Bt-PEG) thiol/PEG thiol (1:3), neutravidin, and biotinylated aptamer in a sandwich format. The 1:3 (v/v) ratio of Bt-PEG thiol/PEG thiol was specifically chosen to maximize PAO1 binding while minimizing nonspecific adsorption and steric hindrance. In contrast to prior whole-cell LSPR work, the LSPR wavelength shift was shown to be linearly related to bacterial concentration over the range of 10-103 cfu mL-1. This LSPR sensing platform is rapid (∼3 h for detection), sensitive (down to the level of a single bacterium), selective for detection of Pseudomonas strain PAO1 over other strains, and exhibits a clinically relevant dynamic range and excellent shelf life (≥2 months) when stored at ambient conditions. This versatile LSPR sensing platform should be extendable to a wide range of supermolecular analytes, including both bacteria and viruses, by switching affinity reagents, and it has potential to be used in point-of-care and field-based applications.

Polymer particles filled with multiple colloidal silica via in situ sol-gel process and their thermal property.

The in situ formation of dielectric silica (SiO2) particles was carried out in the presence of temperature-responsive poly(N-isopropylacrylamide) particles. Unlike the typical sol-gel method used to prepare various SiO2 particles, the highly uniform growth of SiO2 particles was achieved within the cross-linked polymer particles (i.e., the polymer particles were filled with the SiO2 particles) simply by utilizing interfacial interactions, including the van der Waals attractive force and hydrogen bonding in nanoscale environments. The structural and morphological features as well as the thermal behaviors of these composites were thoroughly examined by electron microscopes, dynamic light scattering, and thermal analyzers. In particular, the thermal properties of these composites were completely different from the bare polymer, SiO2 particles, and their mixtures, which clearly suggested the successful incorporation of multiple SiO2 particles within the cross-linked polymer particles. Similarly, titanium oxide (TiO2) particles were easily embedded within the polymer particle template which exhibited improved overall properties. As a whole, understanding in situ formation of nanoscale inorganic particles within polymer particle templates can allow for designing novel composite materials possessing enhanced chemical and physical properties.

Explicit memory and implicit memory in occipital lobe stroke patients.

BACKGROUND: Occipital stroke patients mainly showed cortical blindness and unilateral vision loss; memory is generally reserved. Recent reports from neuroimaging show the occipital lobe may be involved in the processing of implicit memory (IM), especially the perception type of IM processing. In this study, we explored the explicit memory (EM) and IM damage in occipital lobe stroke patients. METHODS: A total of 25 occipital strokes and 29 years of age, educational level equivalent healthy controls (HCs), evaluated by using immediate recall, delayed recall, recognition for EM tasks, picture identification, and category exemplar generation for IM tasks. RESULTS: There was no significant difference between occipital stroke patients and HCs in EM tasks and category exemplar generation task. In the picture identification task, occipital lobe stroke group score was poorer than HC group, the results were statistically significant, but in the pictures identify rate, occipital stroke patients and normal control group had no significant difference. CONCLUSIONS: The occipital stroke patients may have IM damage, primarily damage the perception type of IM priming effects, which was unrelated with their cortical blindness.

Construction of a novel fluorescent probe for sensitive determination of glyphosate in food and imaging living cells.

Glyphosate is a widely used broad-spectrum herbicide in agriculture and horticulture to control a variety of weeds and undesirable plants. However, the excessive use of glyphosate has raised a number of environmental and human health concerns. It is urgent to develop tools to detect glyphosate. Herein, a novel dual-signal probe CCU-Cu2+ was designed and synthesized on the basis of CCU. CCU exhibited excellent selectivity and great sensitivity for Cu2+ which were based on both fluorescence "turn-off" reaction and comparative color visualisation methods. Due to the strong chelating ability of glyphosate on Cu2+, the CCU-Cu2+ complex was applied to glyphosate detection in practical samples. The experimental results in vitro showed that the CCU-Cu2+ complex was highly selective and rapid, with a low detection limit (1.6 µM), and could be recognised by the naked eye in the detection of glyphosate. Based on the excellent properties of the CCU-Cu2+ complex, we also constructed a smartphone-assisted detection sensing system for glyphosate detection, which has the advantages of precision, sensitivity, and high interference immunity. Moreover, the CCU-Cu2+ complex was also successfully employed for exogenous glyphosate imaging in living cells. These characteristics demonstrated that CCU-Cu2+ holds significant potential for detection and imaging of glyphosate in bio-systems.

Preparation and characterization of flexible laminated composites impregnated with TPU/SiO2 for static puncture resistance.

At present, people face the danger of various occupational exposures, resulting in the rapid development of protective composites among which puncture-resistant materials are an essential component. In this article, composites impregnated with polyester polyurethane (TPU)/SiO2 are used to improve static puncture resistance. Different types of TPU and different concentrations of SiO2 in the impregnation solution are selected. The mechanical and wearing-related properties of composites are systematically explored and analyzed. The results show that static puncture resistance and tensile strength are improved after impregnation. Meanwhile, the composites can still maintain a good water-vapor transmission rate. The air permeability, tearing strength, elongation at break and flexibility of the composites decrease slightly. This study provides a novel and feasible strategy to prepare a flexible composite with high static puncture resistance as well as excellent wearability which is a desirable candidate as a garment accessory or gaket protecting the human body from puncture risk.

Thermally tunable catalytic and optical properties of gold-hydrogel nanocomposites.

We have developed a very simple approach for preparing physically embedded gold cores in a temperature-responsive hydrogel polymer nanoparticle under fluorescent light irradiation. The complete encapsulation of the multiple gold core nanoparticles is confirmed by the catalytic reduction of 4-nitrophenol, whose reactivity is significantly retarded above the lower critical solution temperature (LSCT) due to the deswelled polymer structure; its increased hydrophobicity slows the access of hydrophilic reactants to the cores. Since these gold cores are physically embedded in the polymer nanoparticles, further growth of the cores is reliably achieved in situ under light irradiation. Interestingly, the resulting composite nanoparticles exhibit reversible solution color changes as well as absorption bands from the visible to near-IR regions below and above the LSCT.

Isolation and production optimization of a novel milk-clotting enzyme Bacillus velezensis DB219.

The milk-clotting enzyme (MCE) is a crucial ingredient in cheese manufacture. Due to the limits of traditional MCE, finding viable substitute is a pressing issue. This study aims to isolate and identify a wild strain with high milk-clotting activity (MCA) and low proteolytic activity (PA) and optimize the fermentation conditions for MCE production. A strain of Bacillus velezensis DB219 with high MCA/PA value (9.2) was isolated from dairy soil (Wuchang, Heilongjiang, China) and identified through 16S rRNA from 40 strains. The optimal wheat bran, carbon, nitrogen, inoculum size, volume and initial pH were 60 g/L, soluble starch 12.5 g/L, corn steep liquor 3 g/L, 5%, 40 mL and 6.15, respectively for improving DB219 MCE production through single factor experiment. The wheat bran concentration, corn steep liquor concentration and volume were the most critical factor and their changed range was determined through Plackett-Burman design and the steepest ascent/descent experiments. The response surface analysis experiment of three factors and three levels was conducted by Box-Behnken design. The theoretical optimal fermentation conditions for DB219 MCE were as follows: wheat bran concentration 60.14 g/L, soluble starch 12.5 g/L, corn steep liquor 3 g/L, inoculum size 5%, volume 40.08 mL and initial pH 6.15. DB219 MCE achieved the maximal MCA (3164.84 SU/mL) that was 101.9% of the predicted value (3104.49 SU/mL) and 4.3-fold higher than the control.

[Determination of tenacissoside H in Marsdeniae tenacissimae by HPLC-ELSD].

In order to improve the quality standard of Marsdenia tenacissima, a quantitative determination method of tenacissoside H was developed using high performance liquid chromatography. The method was carried out on a YMC ODS-H80 (4.6 mm x 250 mm, 4 microm) column eluted with a mixture of acetonitrile and water (50:50) as the mobile phase. The flow rate was 0.8 mL x min(-1) and the column temperature was 35 degrees C. An evaporative light scattering detector (ELSD) was used with the temperature of drift tube set at 60 degrees C and the gas flow rate of nitrogen set at 1.5 mL x min(-1). The calibration curve was linear in the range from 0.5625 to 36.00 microg (r = 0.9998). The average recovery and RSD were 99.41% and 1.8%, respectively. The contents of tenacissoside H in the 11 samples from different habitats varied from 0.201% to 0.862%. The method established in this paper is specific and reliable to control and evaluate the quality of M. tenacissima.

Whole-cell biosensing by siderophore-based molecular recognition and localized surface plasmon resonance.

A siderophore-based active bacterial pull-down strategy was integrated in a localized surface plasmon resonance (LSPR) sensing platform and subsequently tested by detecting whole-cell Acinetobacter baumannii. The LSPR-based whole-cell sensing approach was previously demonstrated with aptamer-based molecular recognition motifs, and here it is extended to the powerful siderophore system, which exploits the natural bacterial need to sequester Fe(III). Specifically, a biscatecholate-monohydroxamate mixed ligand siderophore linked to a biotin via three polyethylene glycol repeating units was synthesized and immobilized on Au trigonal nanoprisms of an LSPR sensor. The resulting surface-confined biotinylated siderophore subsequently chelated Fe(III), forming a siderophore-Fe(III) complex which was shown to be competent to recognize A. baumannii. Target bacteria were captured and then detected by measuring wavelength shifts in the LSPR extinction spectrum. This siderophore pull-down LSPR biosensor approach is rapid (≤3 h detection) and sensitive - with a limit of detection (LOD) of 80 bacterial cells and a linear wavelength shift over the range 4 × 102 to 4 × 106 cfu mL-1. As intended by design, the siderophore-based biosensor was selective for A. baumannii over Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus, and was stable in ambient conditions for up to 2 weeks.

Microscale and Nanoscale Electrophotonic Diagnostic Devices.

Detecting and identifying infectious agents and potential pathogens in complex environments and characterizing their mode of action is a critical need. Traditional diagnostics have targeted a single characteristic (e.g., spectral response, surface receptor, mass, intrinsic conductivity, etc.). However, advances in detection technologies have identified emerging approaches in which multiple modes of action are combined to obtain enhanced performance characteristics. Particularly appealing in this regard, electrophotonic devices capable of coupling light to electron translocation have experienced rapid recent growth and offer significant advantages for diagnostics. In this review, we explore three specific promising approaches that combine electronics and photonics: (1) assays based on closed bipolar electrochemistry coupling electron transfer to color or fluorescence, (2) sensors based on localized surface plasmon resonances, and (3) emerging nanophotonics approaches, such as those based on zero-mode waveguides and metamaterials.

Enhanced sensitivity of capture IgE­ELISA based on a recombinant Der f 1/2 fusion protein for the detection of IgE antibodies targeting house dust mite allergens.

The detection of allergen­specific immunoglobulin (Ig)E is an important method for the diagnosis of IgE­mediated allergic diseases. The sensitivity of the indirect IgE­ELISA method against allergen extracts is limited by interference from high IgG titers and low quantities of effectual allergen components in extracts. To overcome these limitations, a novel capture IgE­ELISA based on a recombinant Der f 1/Der f 2 fusion protein (rDer f 1/2) was developed to enhance the sensitivity to IgEs that bind allergens from the house dust mite (HDM) species Dermatophagoides farina. pET28­Der f 1/2 was constructed and expressed in Escherichia coli BL21 (DE3) pLysS. The purified fusion protein was evaluated by IgE western blotting, IgE dot blotting and indirect IgE­ELISA. Capture­ELISA was performed by coating wells with omalizumab and incubating in series with sera, biotinylated Der f 1/2, horseradish peroxidase­conjugated streptavidin and 3,3,5,5­tetramethylbenzidine. The relative sensitivities of indirect­ELISA and capture­ELISA for HDM allergen­specific IgE binding were determined; sera from non­allergic individuals were used as the control group. rDer f 1/2 was expressed in the form of inclusion bodies comprising refolded protein, which were then purified. It exhibited increased IgE­specific binding (24/28, 85.8%) than rDer f 1 (21/28, 75.0%) or rDer f 2 (22/28, 78.6%) with HDM­allergic sera. Furthermore, in a random sample of HDM­allergic sera (n=71), capture­ELISA (71/71, 100%) was more sensitive than indirect­ELISA (68/71, 95.8%) for the detection of HDM­specific IgEs (P<0.01), indicating that this novel method may be useful for the diagnosis of HDM allergy.

Anti-IgE therapy for IgE-mediated allergic diseases: from neutralizing IgE antibodies to eliminating IgE+ B cells.

Allergic diseases are inflammatory disorders that involve many types of cells and factors, including allergens, immunoglobulin (Ig)E, mast cells, basophils, cytokines and soluble mediators. Among them, IgE plays a vital role in the development of acute allergic reactions and chronic inflammatory allergic diseases, making its control particularly important in the treatment of IgE-mediated allergic diseases. This review provides an overview of the current state of IgE targeted therapy development, focusing on three areas of translational research: IgE neutralization in blood; IgE-effector cell elimination; and IgE+ B cell reduction. IgE-targeted medicines such as FDA approved drug Xolair (Omalizumab) represent a promising avenue for treating IgE-mediated allergic diseases given the pernicious role of IgE in disease progression. Additionally, targeted therapy for IgE-mediated allergic diseases may be advanced through cellular treatments, including the modification of effector cells.

Optical Biosensing of Bacteria and Bacterial Communities.

Bacterial sensing is important for understanding the numerous roles bacteria play in nature and in technology, understanding and managing bacterial populations, detecting pathogenic bacterial infections, and preventing the outbreak of illness. Current analytical challenges in bacterial sensing center on the dilemma of rapidly acquiring quantitative information about bacteria with high detection efficiency, sensitivity, and specificity, while operating within a reasonable budget and optimizing the use of ancillary tools, such as multivariate statistics. This review starts from a general description of bacterial sensing methods and challenges, and then focuses on bacterial characterization using optical methods including Raman spectroscopy and imaging, infrared spectroscopy, fluorescence spectroscopy and imaging, and plasmonics, including both extended and localized surface plasmon resonance spectroscopy. The advantages and drawbacks of each method in relation to the others are discussed, as are their applications. A particularly promising direction in bacterial sensing lies in combining multiple approaches to achieve multiplex analysis, and examples where this has been achieved are highlighted.

Pains and Gains from China's Experiences with Emerging Epidemics: From SARS to H7N9.

Over the recent decades, China experienced several emerging virus outbreaks including those caused by the severe acute respiratory syndrome- (SARS-) coronavirus (Cov), H5N1 virus, and H7N9 virus. The SARS tragedy revealed faults in China's infectious disease prevention system, propelling the Chinese government to enact reforms that enabled better combating of the subsequent H1N1 and H7N9 avian flu epidemics. The system is buttressed by three fundamental, mutually reinforcing components: (1) enduring government administration reforms, including legislation establishing a unified public health emergency management system; (2) prioritized funding for biotechnology and biomedicine industrialization, especially in the areas of pathogen identification, drug production, and the development of vaccines and diagnostics; and (3) increasing investment for public health and establishment of a rapid-response infectious diseases prevention and control system. China is now using its hard-gained experience to support the fight against Ebola in Africa and the Middle East Respiratory Syndrome in its own country.

Dissociation between Conceptual and Perceptual Implicit Memory: Evidence from Patients with Frontal and Occipital Lobe Lesions.

The latest neuroimaging studies about implicit memory (IM) have revealed that different IM types may be processed by different parts of the brain. However, studies have rarely examined what subtypes of IM processes are affected in patients with various brain injuries. Twenty patients with frontal lobe injury, 25 patients with occipital lobe injury, and 29 healthy controls (HC) were recruited for the study. Two subtypes of IM were investigated by using structurally parallel perceptual (picture identification task) and conceptual (category exemplar generation task) IM tests in the three groups, as well as explicit memory (EM) tests. The results indicated that the priming of conceptual IM and EM tasks in patients with frontal lobe injury was poorer than that observed in HC, while perceptual IM was identical between the two groups. By contrast, the priming of perceptual IM in patients with occipital lobe injury was poorer than that in HC, whereas the priming of conceptual IM and EM was similar to that in HC. This double dissociation between perceptual and conceptual IM across the brain areas implies that occipital lobes may participate in perceptual IM, while frontal lobes may be involved in processing conceptual memory.

Sunlight-induced synthesis of various gold nanoparticles and their heterogeneous catalytic properties on a paper-based substrate.

This work describes the light-induced preparation of various gold nanoparticles and demonstrates their possible use as efficient photothermal heating materials and practical heterogeneous catalysts under the irradiation of a solar-based light after being loaded onto a paper-based substrate. The synthesis of gold nanoparticles was accomplished under the irradiation of daily sunlight and a solar-simulated light with an intensity that was closely adjusted to the one-sun condition. Tunable sizes of gold nanoparticles were systematically controlled by the ratio of trisodium citrate and gold chloride ions, particularly with the solar-simulated light source. The size distribution and absorption properties of the resulting nanoparticles were thoroughly characterized by scanning electron microscope, dynamic light scattering, and UV-visible spectroscopy. The broad-band solar-based light sources were found to be efficient external stimuli to induce/enhance the formation of various gold nanoparticles at room temperature. As gold nanoparticles typically exhibit efficient light-induced heating properties due to their strong absorption bands, these nanoparticles were physically embedded on a filter paper to examine their photothermal heating properties and heterogeneous catalytic activity in the reduction of 4-nitrophenol under the irradiation of the solar-simulated light. As expected, the gold-loaded filter papers exhibited a systematic increase of temperature as a function of the gold nanoparticle concentration and enhanced catalytic property under the irradiation of the light, presumably caused by the photothermally induced heating property of the loaded gold nanoparticles. Overall, solar-based light sources can offer dual functions for the synthesis and application of metal nanoparticles possessing strong absorption bands.