Notes

Propionibacterium acnes endophthalmitis following transplantation regarding contaminated Descemet's membrane endothelial keratoplasty graft.
Because of excellent blood-brain barrier (BBB) permeability, good biocompatibility and stability, high specificity towards Aβ oligomers as well as strong turn-on fluorescence upon Aβ binding, DBAN-SLM was successfully applied for in vivo and ex vivo imaging of Aβ in AD mouse model, signifying its great promise as a useful theranostic agent for the early diagnosis and therapy of AD. Our results also demonstrated for the first time that the dibutyl-2-naphthylamine moiety is a useful and effective structural building block to promote the targeting capability of oligomeric Aβ.Illegal trafficking of pharmaceutical products by criminal organisations is a global threat for public health. Drugs for erectile dysfunction such as phosphodiesterase type 5 inhibitors are the most commonly counterfeited medicines in Europe. The search of possible toxic chemical substances in seized products is needed to provide early warning for public health. Furthermore, the elemental profile of the seized products can be useful in criminal investigations. For the first time an ion beam analysis (IBA) procedure to characterise authentic Viagra® tablets and sildenafil-based illegal products is described. Moreover, results are compared with the ones obtained by instrumental neutron activation analysis (INAA) on authentic Viagra® tablets in two reactors. IBA results showed that a combination of particle-induced X-ray emission (PIXE) and secondary ion mass spectrometry using primary ions with energies in the range of several MeV (MeV-SIMS) is a powerful tool to characterise different products in a straightforward manner, allowing discrimination between legal and illegal products. INAA allowed accurate elemental quantification and also showed a great potential for the future implementation of an inter-laboratory classification system.Fluorescent quantum dots (QDs), defined by a diameter size of less then 10 nm, have been the core concept of nanoscience and nanotechnology since their inception. QDs possess many unique structural, electrochemical and photochemical properties that render them a promising platform for sensing applications. These nanomaterials can greatly enhance the analytical performances of biosensors, namely detection limit, sensitivity and selectivity. QDs are being developed not only because of their ability for signal enhancement but also because of their high capacity for fuctionalization with bioreceptors. In this review, we summarize a basic knowledge of QDs before focusing on their application to sensing thus far followed by a discussion of future directions for research into the sensing field. Due to the nature of QDs, especially their ability to combine nanotechnology and biotechnology, they possess the potential to open a novel paradigm on early diagnosis of diseases using the electrochemical biosensors. Therefore, we try to give a comprehensive view of the role of these zero-dimensional (0D) nanomaterials in the designing electrochemical sensors for determination of disease-related biomolecules, including tumor markers, inflammatory biomarkers, depression markers and archetypal biomarker in diabetes diagnosis. Considering the high potential of QDs for the electrochemistry-based biosensing strategies, the authors suggest that more research is needed on understanding their electronic properties and why synthesis and surface modification methods can affect these properties.The technological growth, the increasing safety, and production standards cascade down to the quality of the raw materials. The development of analytical methods for high quality powder analysis needs to grow parallel to this trend. It is established that particle metal contaminants could trigger violent failures of lithium-ion batteries and compromise the battery performance, and the safety of the end user. Increased miniaturization requires exponential increases in quality of raw materials putting laboratories in a continuous process of development to achieve ever higher standards. Trace elements in a powder material can be present in different states, and their effect on the application can therefore be different according to the status. Trace elements can be present in the material as a dissolved impurity or as a particle contamination. Here we present an experimental method which is easy to implement and use, and is sensitive to contaminants (i.e. external particles that are not part of the material of interest) over total trace elements. Contaminants typically are a few orders of magnitude lower in concentration than total trace elements. The method focuses on the quantification of Fe, Ni and Cr in high purity carbon powders used in the lithium-ion battery industry. We present test sample size calculations prior to the method description to ensure high precision and assess possible bias. The method is based on the magnetic extraction of a large test sample, followed by acid digestion and quantification. The procedure and the method performance are described. The method ensures low levels of detection and quantification, high precision, and accuracy.Lysine methylations are common protein post-translational modifications (PTMs), that play significant roles in regulating gene activities. Studies of their functions and connections with diseases have important values. However, due to the small variations from their native structures and very low component proportions, it is very difficult to extract methylated peptides from biological mixtures. In this research, a new material that utilizes sulfonated calix[4]arene (SC4A) as the recognition unit and silica coated with TiO2 as carrier, denoted as SiO2@TiO2@SC4A, was synthesized. The equilibrium binding experiments demonstrated that SiO2@TiO2@SC4A can identify lysine and arginine methylation and peptides with these methylated residues. The maximum isotherm binding capacities are 70.0, 55.9, 31.4 and 24.8 μmol g-1 for Lys(Me3), Lys(Me)2, Lys(Me) and Lys, respectively. It demonstrated that the higher the degree of methylation, the stronger the interactions. https://www.selleckchem.com/products/tlr2-in-c29.html In addition, the analyses of high performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) demonstrated that peptides with methylated lysine or arginine can be selectively extracted from spiked histone trypsin digestion. The recoveries for the spiked GGAK(Me)R, GGAKR(Me)2 and GGAK(Me)3R are 83%, 78%, and 84% respectively. The experiments from the nuclear extracts of HeLa cells also illustrated that SiO2@TiO2@SC4A holds a potential in the enrichment and identification of lysine methylations.Osteoporosis (OP) is a bone disease involved in dysregulation of one of the bone metabolism arms, formation, or desorption cause a porous bone. Osteocalcin (OC) and beta-crosslap (BC), are the well-known markers for OP, which are connected to bone formation and desorption, respectively. In addition to the OP biomarker, BC is also used as an estrogen replacement therapeutic monitoring. ELISA and other antibody-based detection methods are routinely used for measuring OC and BC. These methods have limitations that include thermostability, sensitivity, sacrificing animals, and cost of production. However, aptamer-based-assays are of interest to overcome these drawbacks and achieve the most specific and robust application. Herein, specific aptamers for OC and BC were selected by the systematic evolution of ligands by exponential enrichment (SELEX) method from the pool of ssDNA library with 60 random sequences. The binding affinity (Kd) of the selected aptamers were evaluated against the respective biomarkers. The high-affinity aptamers of OC and BC showed the Kd values of 59 and 55 nM respectively. A graphene oxide-based aptasensors were fabricated from the high-affinity aptamers, and the detection limits of OC and BC were found to be 0.4 pg/ml and 0.21 pg/ml, respectively. These aptasensors have been tested with OC and BC spiked buffer samples and validated using serum samples collected from osteoporotic rats.The potential of a portable Near Infrared spectrophotometer compared with that of NIR benchtop equipment is assessed to determine the13C/12C relationship of stable isotopes and the fatty acid content. 105 samples of subcutaneous fat of Iberian pigs collected at the time of their slaughter have been analyzed. The analysis of stable isotopes and gas chromatography were the methods of reference used. The samples were analyzed without prior handling (portable and benchtop NIR) and after extracting the fat (benchtop NIR). The results show that with the portable equipment it is possible to determine δ13C (‰), 12 fatty acids, and 5 summations of fatty acids (SFA, MUFA, PUFA, w3, and w6), while with the benchtop NIR equipment it is possible to measure δ13C (‰), 16 fatty acids, and the 5 summationsof fatty acids. The correlation coefficients of the portable equipment were slightly lower than those of the NIR benchtop equipment.The single tumor antigen does not have enough specificity and sensitivity to meet the accurate diagnostic criteria, and single antigen measurement is often prone to false negative and false positive perceptions. Therefore, simultaneous monitoring of multiple tumor antigens related to precise tumors in serum samples has become an interesting and encouraging analytical method. In this work, we demonstrated an electrochemical biosensor based on multiple signal amplification methods, and simultaneously detect two lung cancer markers, cytokeratin 19 fragment 21-1 (CYFRA21-1) and carcinoembryonic antigen (CEA). Large number of gold nanoparticles distributed on the surface of three-dimensional graphene (3D-G), poly-thionine (pThi) and poly-m-Cresol purple (pMCP) not only provide large number of binding sites for antigen and antibody, but also enhance the electrochemical signal of biosensor and greatly improves the sensitivity of the biosensor. The detection linear range extends from 0.5 to 200 ng/mL, with low detection limits (LOD) of 0.18 ng/mL and 0.31 ng/mL for CYFRA21-1 and CEA, respectively. Overall, this kind of immune-biosensor provides great potential for the simultaneous detection of multiple targets in early clinical diagnosis.Rapid, periodic monitoring and detection of ethanol (EtOH) after consumption via a non-invasive measurement has been an area of increased research in recent years. Current point-of-care or on-site detection strategies rely on single use sensors which are inadequate for monitoring during a longer period. A low cost, portable and novel approach is developed here for real-time monitoring over several days utilising electrochemical techniques. The sensor shows oxidation of the ethanol in phosphate buffer and artificial sweat using the amperometric response from the application of +0.9 V to the polyaniline modified screen printed electrode using 1 mM EtOH as the averaged amount of EtOH eliminated in sweat after the consumption of one alcoholic beverage. Our enzyme based electrochemical sensor exhibits a qualitative assessment of the presence of EtOH in small volumes (≤40 μL) of 0.1 M sodium bicarbonate and subsequently artificial sweat, with 50 measurements taken daily over 11 days. While quantitative information is not obtained, the sensor system exhibits excellent stability after 3 months' dried storage in this complex biological matrix in an oxygen free cabinet.
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