Zinc oxide nanoparticle-embedded tannic acid/chitosan-based sponge: A highly absorbent hemostatic agent with enhanced antimicrobial activity.

This study reports the development of a highly absorbent Chitosan (CS)/Tannic Acid (TA) sponge, synthesized via chemical cross-linking with Epichlorohydrin (ECH) and integrated with zinc oxide nanoparticles (ZnO NPs) as a novel hemostatic anti-infection agent. The chemical properties of the sponges were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and zeta potential measurements. Morphological and elemental analyses conducted through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX) revealed a uniform distribution of ZnO NPs, with particle sizes below 20 nm.

Structure and phase changes of alumina produced by flame hydrolysis.

Fumed alumina from the combustion of AlCl produced nano particles with specific areas from 30 to 220 m g (BET) which were characterized by powder X-ray diffraction, Al solid-state NMR and transmission electron microscopy. During the short-lived synthesis, highly disordered γ-alumina progressively transforms into a mixture of δ and θ-alumina. For the γ-alumina particles, only for particles with the highest specific area a significant amount of five-coordinated Al can be found which is only partially located in the particle surface.

Method for Surface Characterization Using Solid-State Nuclear Magnetic Resonance Spectroscopy Demonstrated on Nanocrystalline ZnO:Al.

Nanoscale zinc-oxide doped with aluminum ZnO:Al is studied by different techniques targeting surface changes induced by the conditions at which ZnO:Al is used as support material in the catalysis of methanol. While it is well established that a variety of H and Al resonances can be found by solid-state NMR for this material, it was not clear yet which signals are related to species located close to the surface of the material and which to species located in the bulk. To this end, a method is suggested that makes use of a paramagnetically impregnated material to suppress NMR signals close to the particle surface in the blind sphere around the paramagnetic metal atoms.

Influence of Mg on the Li ion mobility in LiMgPS.

Aliovalent substitution of Li in salts by Mg can generate Li vacancies and thus in principle improve the ionic conductivity. In fact the influence of substitution on ionic conductivity is far more complex. Here the impact of Mg substitution on Li ion mobility is studied in the example of LiPS by a combination of nuclear magnetic resonance experiments on P and Li at variable temperatures, impedance spectroscopy and X-ray powder diffraction to elucidate the relationship with structural changes and the effect on mobility on different length scales.

Echo pulses for background suppression by optimal control.

Materials used to construct magic-angle-spinning NMR probes can contain NMR active nuclei that produce a significant amount of background signal. Because these materials are located outside the sample coil, the use of spatially selective pulses to remove the background is a popular approach for background suppression. However, previously suggested spatially selective pulses suffer from limited excitation bandwidths, which may make them unsuitable for the acquisition of nuclei with a large chemical shift range.

On-Demand Cell Sheet Release with Low Density Peptide-Functionalized Non-LCST Polymer Brushes.

Cell sheet harvesting offers a great potential for the development of new therapies for regenerative medicine. For cells to adhere onto surfaces, proliferate, and to be released on demand, thermoresponsive polymeric coatings are generally considered to be required. Herein, an alternative approach for the cell sheet harvesting and rapid release on demand is reported, circumventing the use of thermoresponsive materials.

Digitization of imaging plates from Guinier powder X-ray diffraction cameras.

A Guinier camera equipped with an imaging plate is used to investigate and eliminate the sources of instrumental errors affecting the quality of the obtained scanned Guinier data. A program with a graphical user interface is presented which converts the data of the scanned images into different standard file formats for powder X-ray patterns containing intensities, their standard deviations and the diffraction angles. The program also allows for manual and automatic correction of the 2θ scale against a known reference material.

Silver nanoparticles adversely affect the swimming behavior of European Whitefish () larvae within the low µg/L range.

The aim of this study was to determine the effects of silver nanoparticles (AgNPs; speciation: NM-300 K) in the lab on the behavior of larvae in European Whitefish (), a relevant model species for temperate aquatic environments during alternating light and darkness phases. The behavioral parameters measured included activity, turning rate, and distance moved. were exposed to AgNP at nominal concentrations of 0, 5, 15, 45, 135, or 405 µg/L (n = 33, each) and behavior was recorded using a custom-built tracking system equipped with light sources that reliably simulate light and darkness.

Matrixyl Patch vs Matrixyl Cream: A Comparative In Vivo Investigation of Matrixyl (MTI) Effect on Wound Healing.

Wound healing is one of the most complex biological processes. Studies show that Matrixyl (MTI), known as a cosmetic peptide, can lead to a faster healing process. The contribution of MTI to collagen formation during wound healing also depends on its mode of delivery and its release over time.

Discrimination of Stressed and Non-Stressed Food-Related Bacteria Using Raman-Microspectroscopy.

As the identification of microorganisms becomes more significant in industry, so does the utilization of microspectroscopy and the development of effective chemometric models for data analysis and classification. Since only microorganisms cultivated under laboratory conditions can be identified, but they are exposed to a variety of stress factors, such as temperature differences, there is a demand for a method that can take these stress factors and the associated reactions of the bacteria into account. Therefore, bacterial stress reactions to lifetime conditions (regular treatment, 25 °C, HCl, 2-propanol, NaOH) and sampling conditions (cold sampling, desiccation, heat drying) were induced to explore the effects on Raman spectra in order to improve the chemometric models.

Incubation media modify silver nanoparticle toxicity for whitefish () and roach () embryos.

Toxicological studies were performed to examine silver nanoparticle (AgNP, size: 14.4 ± 2.5 nm) transformation within three different test media and consequent effects on embryos of whitefish () and roach ().

Cooperative Effects in Switchable Catalysis: Enhancing Double-Click Reaction Yield of Symmetrical Rotaxanes.

Reversible switching between the closed cyclic dimeric assembly [Cu (1) ] (OFF state) and the extended dimeric homoleptic complex [FeCu (1) ] (ON State) by addition/removal of Fe triggered catalysis of a double-click reaction and high yield preparation of [2]rotaxanes. Mechanistic and computational studies provide valuable general insight for double-click strategies by revealing cooperative effects in the second cycloaddition step due to a distance-tolerant preorganization of the first-click product by the two copper(I)-loaded phenanthroline subunits of [FeCu (1) ] .

Restoring Endogenous Repair Mechanisms to Heal Chronic Wounds with a Multifunctional Wound Dressing.

Current treatment of chronic wounds has been critically limited by various factors, including bacterial infection, biofilm formation, impaired angiogenesis, and prolonged inflammation. Addressing these challenges, we developed a multifunctional wound dressing-based three-pronged approach for accelerating wound healing. The multifunctional wound dressing, composed of nanofibers, functional nanoparticles, natural biopolymers, and selected protein and peptide, can target multiple endogenous repair mechanisms and represents a promising alternative to current wound healing products.

Rapid detection and discrimination of food-related bacteria using IR-microspectroscopy in combination with multivariate statistical analysis.

Spoilage microorganisms are of great concern for the food industry. While traditional culturing methods for spoilage microorganism detection are laborious and time-consuming, the development of early detection methods has gained a lot of interest in the last decades. In this work a rapid and non-destructive detection and discrimination method of eight important food-related microorganisms (Bacillus subtilis DSM 10, Bacillus coagulans DSM 1, Escherichia coli K12 DSM 498, Escherichia coli TOP10, Micrococcus luteus DSM 20030, Pseudomonas fluorescens DSM 4358, Pseudomonas fluorescens DSM 50090 and Bacillus thuringiensis israelensis DSM 5724) based on IR-microspectroscopy and chemometric evaluation was developed.

Multiplexed detection and differentiation of bacterial enzymes and bacteria by color-encoded sensor hydrogels.

We report on the fabrication and characterization of color-encoded chitosan hydrogels for the rapid, sensitive and specific detection of bacterial enzymes as well as the selective detection of a set of tested bacteria through characteristic enzyme reactions. These patterned sensor hydrogels are functionalized with three different colorimetric enzyme substrates affording the multiplexed detection and differentiation of α-glucosidase, β-galactosidase and β-glucuronidase. The limits of detection of the hydrogels for an observation time of 60 min using a conventional microplate reader correspond to concentrations of 0.

Drug Release from Thermo-Responsive Polymer Brush Coatings to Control Bacterial Colonization and Biofilm Growth on Titanium Implants.

Despite decades of biomedical advances, the colonization of implant devices with bacterial biofilms is still a leading cause of implant failure. Clearly, new strategies and materials that suppress both initial and later stage bacterial colonization are required in this context. Ideal would be the implementation of a bactericidal functionality in the implants that is temporally and spatially triggered in an autonomous fashion at the infection site.

Berberrubine Phosphate: A Selective Fluorescent Probe for Quadruplex DNA.

A phosphate-substituted, zwitterionic berberine derivative was synthesized and its binding properties with duplex DNA and G4-DNA were studied using photometric, fluorimetric and polarimetric titrations and thermal DNA denaturation experiments. The ligand binds with high affinity toward both DNA forms ( = 2-7 × 10 M) and induces a slight stabilization of G4-DNA toward thermally induced unfolding, mostly pronounced for the telomeric quadruplex . The ligand likely binds by aggregation and intercalation with ct DNA and by terminal stacking with G4-DNA.

Selective, pH-Dependent Colorimetric and Fluorimetric Detection of Quadruplex DNA with 4-Dimethylamino(phenyl)-Substituted Berberine Derivatives.

The 9- and 12-dimethylaminophenyl-substituted berberine derivatives 3 a and 3 b were readily synthesized by Suzuki-Miyaura reactions and shown to be useful fluorescent probes for the optical detection of quadruplex DNA (G4-DNA). Their association with the nucleic acids was investigated by spectrometric titrations, CD and LD spectroscopy, and with DNA-melting analysis. Both ligands bind to duplex DNA by intercalation and to G4-DNA by terminal π stacking.

Multitasking with Chemical Fuel: Dissipative Formation of a Pseudorotaxane Rotor from Five Distinct Components.

A 3-fold completive self-sorted library of dynamic motifs was integrated into the design of the pseudorotaxane-based rotor [Zn(·H)()()] operating at = 15.4 kHz. The rotational motion in the five-component device is based on association/dissociation of the pyridyl head of the pseudorotaxane rotator arm between two zinc(II) porphyrin stations.

Recent advances for understanding the role of nanobubbles in particles flotation.

Traditional froth flotation is the primary method for the separation and upgrading of fine mineral particles. However, it is still difficult for micro-fine and low-quality minerals to effectively separate. It is generally believed that bubble miniaturization is of great significance to improve flotation efficiency.

Enzyme-Responsive Biopolymeric Nanogel Fibers by Extrusion: Engineering of High-Surface-Area Hydrogels and Application in Bacterial Enzyme Detection.

The fabrication of covalently cross-linked high-surface-area biopolymeric nanogel fibers by nanopore extrusion is reported for the first time. The biopolymer pullulan was functionalized with -butyl acetoacetate via a transesterification reaction to synthesize the water-soluble ketone-rich precursor pullulan acetoacetate (PUAA). PUAA and carbonic dihydrazide (CDH) as cross-linker were extruded through anodic aluminum oxide (AAO) nanoporous membranes, which possessed an average pore diameter of 61 ± 2 nm.