Suitable Matrices Research Articles

MALDI-TOF MS-Based KPC Direct Detection from Patients' Positive Blood Culture Bottles, Short-Term Cultures, and Colonies at the Hospital.

Carbapenemase resistance in Enterobacterales is a global public health problem and rapid and effective methods for detecting these resistance mechanisms are needed urgently. Our aim was to evaluate the performance of a MALDI-TOF MS-based "Klebsiella pneumoniae carbapenemase" (KPC) detection protocol from patients' positive blood cultures, short-term cultures, and colonies in healthcare settings. Bacterial identification and KPC detection were achieved after protein extraction with organic solvents and target spot loading with suitable organic matrices. The confirmation of KPC production was performed using susceptibility tests and blaKPC amplification using PCR and sequencing. The KPC direct detection (KPC peak at approximately 28.681 Da) from patients' positive blood cultures, short-term cultures, and colonies, once bacterial identification was achieved, showed an overall sensibility and specificity of 100% (CI95: [95%, 100%] and CI95: [99%, 100%], respectively). The concordance between hospital routine bacterial identification protocol and identification using this new methodology from the same extract used for KPC detection was ≥92%. This study represents the pioneering effort to directly detect KPC using MALDI-TOF MS technology, conducted on patient-derived samples obtained from hospitals for validation purposes, in a multi-resistance global context that requires concrete actions to preserve the available therapeutic options and reduce the spread of antibiotic resistance markers.

Nonbovine milk and its products as sources of probiotics delivery: An overview of its viability,functionality and product quality characteristics

Dairy products are the most predominant food carriers for probiotics, providing adequate therapeutic and functional benefits to the host when sufficient probiotics are maintained. Bovine milk currently dominates the global probiotic food market, but there is an increasing trend of applying nonbovine milk from other dairy animals as probiotic carrier food matrices as described in this review. Nonbovine dairy products can be considered suitable food matrices for probiotic delivery due to their excellent probiotic viability (mostly >log 7 cfu/mL or g) during shelf life, functional properties and product quality characteristics, being considered desirable and novel dairy products.

Viability of Probiotic Microorganisms and the Effect of Their Addition to Fruit and Vegetable Juices.

Consumers' recent interest in healthier diets has increased the demand for food products with functional properties, such as probiotics. However, most probiotic food types available on the market are of dairy origin, which limits their consumption by individuals with food intolerances and by those who adhere to strict vegan and vegetarian diets. The aim of the current review is to assess both the limitations and impacts of the addition of probiotic microorganisms to fruit, vegetable, and/or mixed juices. Thus, an integrative literature review was herein carried out. A bibliographic survey was carried out in the following databases: Lilacs, Medline, Web of Science, Scopus, and Scielo. In addition, searches for studies published in English from 2010 to 2021 were carried out, based on the following meshes: "fruit", ''vegetable", ''juice", and "probiotics", which were used both in combination with each other and with Boolean operators such as "AND" and "OR". Although 254 articles were initially found in the literature search, only 21 of them were selected to compose the final sample. The included studies mainly addressed microorganism viability and physicochemical analyses. Overall, fruit and/or vegetable juices can be suitable matrices used to help the development of probiotic food types. However, the microorganisms added to these products must be capable of adapting to and surviving in them to enable a product's success. Therefore, factors such as pH, fiber content, amino acids, and phenolic compounds play an essential role in the survival of probiotic microorganisms. Given the wide variety of analyses, a comparison between parameters was the major limitation of the present study. Future studies should focus on filling the gaps persisting in the development of probiotic fruit and/or vegetable juices as well as mixed juices.

Myogenic differentiation of human myoblasts and Mesenchymal stromal cells under GDF11 on Poly-ɛ-caprolactone-collagen I-Polyethylene-nanofibers

BackgroundFor the purpose of skeletal muscle engineering, primary myoblasts (Mb) and adipogenic mesenchymal stem cells (ADSC) can be co-cultured and myogenically differentiated. Electrospun composite nanofiber scaffolds represent suitable matrices for tissue engineering of skeletal muscle, combining both biocompatibility and stability Although growth differentiation factor 11 (GDF11) has been proposed as a rejuvenating circulating factor, restoring skeletal muscle function in aging mice, some studies have also described a harming effect of GDF11. Therefore, the aim of the study was to analyze the effect of GDF11 on co-cultures of Mb and ADSC on poly-ε-caprolactone (PCL)-collagen I-polyethylene oxide (PEO)-nanofibers.ResultsHuman Mb were co-cultured with ADSC two-dimensionally (2D) as monolayers or three-dimensionally (3D) on aligned PCL-collagen I-PEO-nanofibers. Differentiation media were either serum-free with or without GDF11, or serum containing as in a conventional differentiation medium. Cell viability was higher after conventional myogenic differentiation compared to serum-free and serum-free + GDF11 differentiation as was creatine kinase activity. Immunofluorescence staining showed myosine heavy chain expression in all groups after 28 days of differentiation without any clear evidence of more or less pronounced expression in either group. Gene expression of myosine heavy chain (MYH2) increased after serum-free + GDF11 stimulation compared to serum-free stimulation alone.ConclusionsThis is the first study analyzing the effect of GDF11 on myogenic differentiation of Mb and ADSC co-cultures under serum-free conditions. The results of this study show that PCL-collagen I-PEO-nanofibers represent a suitable matrix for 3D myogenic differentiation of Mb and ADSC. In this context, GDF11 seems to promote myogenic differentiation of Mb and ADSC co-cultures compared to serum-free differentiation without any evidence of a harming effect.

Co-Precipitation of Cd, Cr, Pb, Zn, and Carbonates Using Vibrio harveyi Strain Isolated from Mediterranean Sea Sediment

Heavy metal contamination is listed among the most alarming threats to the environment and human health. The detrimental effects of heavy metals in the natural environment span from a reduction of biodiversity to toxic effects on marine life—through microplastic born heavy metals, to impairment of microbial activity in the soil, and to detrimental effects on animal reproduction. A host of different chemical and biological technologies have been proposed to alleviate environmental contamination by heavy metals. Relatively less attention has been paid to the microbial precipitation of heavy metals, as a side mechanism of the most general process of microbially induced calcite precipitation (MICP). This process is currently receiving a great deal of interest from both a theoretical and practical standpoint, because of its possible practical applications in concrete healing and soil consolidation, and its importance in the more general framework of microbial induced mineral precipitation. In this study, we analyse the ability of the marine bacteria Vibrio harveyi in co-precipitating CaCO3 minerals, together with Cd, Cr, Pb, and Zn added in form of nitrates, from solutions containing CaCl2. The precipitated carbonatic minerals were a function of the different heavy metals present in the solution. The process of co-precipitation appears to be rather effective and fast, as the concentrations of the 4 heavy metals were reduced in 2 days by 97.2%, on average, in the solutions. This bioremediation technology could be used as environmental friendly procedure to de-contaminate suitable environmental matrices. The high performance of this process makes it particularly interesting for an upscaling from lab to field.

Manipulation of Organic Afterglow in Fluoranthene-Containing Dopant-Matrix Systems: From Conventional Room-Temperature Phosphorescence to Efficient Red TADF-Type Organic Afterglow.

It remains challenging to fabricate highly-efficient and long-lived organic afterglow materials, especially in the case of red afterglow systems. Here we develop advanced charge transfer (CT) technology to boost afterglow efficiency and lifetimes in fluoranthene-containing dopant-matrix systems. First, organic CT molecules possess singlet-triplet splitting energy (ΔEST ) of around 0.5 eV, much smaller than localized excitation systems. Second, upon doping into suitable organic matrices, dipole-dipole interactions between 1 CT states and organic matrices reduce 1 CT levels with less effect on 3 CT levels, and thus further narrow ΔEST and enhance intersystem crossing. Third, the rigid planar structure of fluoranthene groups and the rigid microenvironment provided by organic matrices can suppress phosphorescence quenching. Forth, the multiple donor design enables spectral red-shifts to red region and switches on TADF mechanism to improve afterglow efficiency to 13.1 % and maintain afterglow lifetime of 0.1 s. Such high-performance afterglow materials have been rarely explored in reported studies.

Biomarkers of Oxidative Stress and Persistent Organic Pollutants in Plasma and Eggs of Chelonia mydas Nesting in the Southern Gulf of Mexico

The major nesting sites for the endangered green turtle (Chelonia mydas) are in Campeche, Mexico: Carmen, Isla Aguada, and Sabancuy. Although they are in a natural reserve, these nesting sites are threatened by agricultural activities and oil extraction. This study aimed to determine the presence and concentration of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in plasma and eggs and to assess the antioxidant response in plasma of nesting C. mydas from the southern Gulf of Mexico. Using censored statistics allowed us to do a realistic calculation incorporating the presence of non-detects in the analysis. A few contaminants (α+β+γ-HCH, trans-chlordane, 4,4′-DDE, 4,4′-DDT, methoxychlor, naphthalene, acenaphthylene, 2-Bromo naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, and dibenz[a,h]anthracene) were detected in plasma and their corresponding eggs, but correlations were not-significant. Spatial differences in concentrations of persistent organic pollutants (POPs) among nesting sites may reflect differences in foraging areas. Approximately 30% of the POPs in plasma and 60% of the POPs in eggs correlated with the biomarkers of oxidative stress. Detection of POPs in C. mydas indicated that plasma and eggs are suitable matrices to assess POPs concentrations.

Attachment of potential cultivable primo-colonizing bacteria and its implications on the fate of low-density polyethylene (LDPE) plastics in the marine environment

Plastics released in the environment become suitable matrices for microbial attachment and colonization. Plastics-associated microbial communities interact with each other and are metabolically distinct from the surrounding environment. However, pioneer colonizing species and their interaction with the plastic during initial colonization are less described. Marine sediment bacteria from sites in Manila Bay were isolated via a double selective enrichment method using sterilized low-density polyethylene (LDPE) sheets as the sole carbon source. Ten isolates were identified to belong to the genera Halomonas, Bacillus, Alteromonas, Photobacterium, and Aliishimia based on 16S rRNA gene phylogeny, and majority of the taxa found exhibit a surface-associated lifestyle. Isolates were then tested for their ability to colonize polyethylene (PE) through co-incubation with LDPE sheets for 60 days. Growth of colonies in crevices, formation of cell-shaped pits, and increased roughness of the surface indicate physical deterioration. Fourier-transform infrared (FT-IR) spectroscopy revealed significant changes in the functional groups and bond indices on LDPE sheets separately co-incubated with the isolates, demonstrating that different species potentially target different substrates of the photo-oxidized polymer backbone. Understanding the activity of primo-colonizing bacteria on the plastic surface can provide insights on the possible mechanisms used to make plastic more bioavailable for other species, and their implications on the fate of plastics in the marine environment.

Quantity and quality of suitable matrices matter in reducing the negative effect of fragmentation

The negative effect of fragmentation is one of the main concerns in the study of biodiversity loss in landscape ecology. The use of the matrix has been considered an important factor because it can change a population's relationship with the configuration of the landscape. A systematic way to assess the effect of matrix quality in fragmented landscapes could lead to a better understanding of how matrices can suppress the negative effect of fragmentation. We built a computational individual-based model capable of simulating bi-dimensional landscapes with three types of land cover (habitat, suitable matrix and hostile matrix) and individuals that inhabit those landscapes. We explored in which situations suitable matrix proportions and the degree of usability of this suitable matrix mitigate the negative effect of fragmentation per se. We observed that (i) an increase in the general matrix quality (increases in the suitable matrix proportion and/or usability) can suppress the fragmentation effect in 47% of the simulated scenarios; (ii) the less usable the matrix is, the more of it is needed to suppress the fragmentation effect; (iii) there is a level of usability below which increasing the suitable matrix proportion does cause the fragmentation effect to cease. These results point toward landscape management decisions that consider the similarity of the matrix to the native habitat under management. We suggest that an index to measure the usability of elements of the matrix could be an important tool for using computational models in landscape management more efficiently.

Force Sensorless Hybrid Position/Force Control with Equivalent Mass Matrices Switching for Decoupled Rubbing Motion

This paper presents a force sensorless workspace hybrid position/force control method with equivalent mass matrices switching for rubbing motion. The equivalent mass matrices express an interference between control axes. Since the determinant of the matrix computed from the design values of robots becomes near zero around the singular configuration of robots, the utilized matrices are often arbitrarily designed. However, inappropriate matrices conditions deteriorate control performance and could cause vibration during rubbing motion. This study reveals suitable equivalent mass matrices for rubbing motion depending on the velocity of the force control axes. Moreover, a hybrid controller with equivalent mass matrices switching depending on the expected velocity of the force control axes in tasks is proposed. The validity of the proposed hybrid controller is demonstrated by the experimental response of rubbing motion with a parallel link type direct-drive four-link manipulator.

Spectral Ranking in Complex Networks Using Memristor Crossbars

Various centrality measures have been proposed to identify the influence of each node in a complex network. Among the most popular ranking metrics, spectral measures stand out from the crowd. They rely on the computation of the dominant eigenvector of suitable matrices related to the graph: EigenCentrality, PageRank, Hyperlink Induced Topic Search (HITS) and Stochastic Approach for Link-Structure Analysis (SALSA). The simplest algorithm used to solve this linear algebra computation is the Power Method. It consists of multiple Matrix-Vector Multiplications (MVMs) and a normalization step to avoid divergent behaviours. In this work, we present an analog circuit used to accelerate the Power Iteration algorithm including current-mode termination for the memristor crossbars and a normalization circuit. The normalization step together with the feedback loop of the complete circuit ensure stability and convergence of the dominant eigenvector. We implement a transistor level peripheral circuitry around the memristor crossbar and take non-idealities such as wire parasitics, source driver resistance and finite memristor precision into account. We compute the different spectral centralities to demonstrate the performance of the system. We compare our results to the ones coming from the conventional digital computers and observe significant energy savings while maintaining a competitive accuracy.

W-MPD–N-DMP-solutions of constrained quaternion matrix equations

Abstract The solvability of several new constrained quaternion matrix equations is investigated, and their unique solutions are presented in terms of the weighted MPD inverse and weighted DMP inverse of suitable matrices. It is interesting to consider some exceptional cases of these new equations and corresponding solutions. Determinantal representations for the solutions of the equations as mentioned earlier are established as sums of appropriate minors. In order to illustrate the obtained results, a numerical example is shown.

Secure Electronic Healthcare Record based on Distributed Global Database and Schnorr Signcryption

Preserving privacy and security plays a key role in allowing each component in the healthcare system to access control and gain privileges for services and resources. Over recent years, there have been several role-based access control and authentication schemes, but we noticed some drawbacks in target schemes such as failing to resist well-known attacks, leaking privacy-related information, and operational cost. To defeat the weakness, this paper proposes a secure electronic healthcare record scheme based on Schnorr Signcryption, crypto hash function, and Distributed Global Database (DGDB) for the healthcare system. Based on security theories and the Canetti-Krawczyk model (CK), we notice that the proposed scheme has suitable matrices such as scalability, privacy preservation, and mutual authentication. Furthermore, findings from comparisons with comparable schemes reveal that the suggested approach provides greater privacy and security characteristics than the other schemes and has enough efficiency in computational and communicational aspects.

A spatial and temporal assessment of microplastics in seafloor sediments: A case study for the UK

Seafloor sediments have been defined as sinks for microplastics in the marine environment and could therefore represent suitable matrices for their long-term monitoring. On a regional aspect, the adoption of a common indicator for microplastics in seafloor sediments would allow regional monitoring and assessments through international frameworks such as OSPAR. This study presents the findings of a research and development project monitoring the occurrence and abundance of microplastics in UK seafloor sediments for the period 2013-2021, supporting the development of a national monitoring programme for microplastics in seafloor sediments for the UK (England and Wales). A fast-screening technique based on Nile Red staining of polymers coupled with µ-FTIR was applied and validated using µ-FTIR-FPA. Microplastic particles were detected in all 189 sediment samples from 15 stations selected around the UK for each investigated year (2013 - 2021). Microplastic concentrations (20 – 5000 µm) ranged from 133 – 6,933 particles kg-1 dry weight sediment for 2020-2021. Microplastics mainly consisted of fragments (73%), fibres (19%) and spheres (8%). Plastic fragments ranged from 46 to 3276 µm and plastic fibres from 300 to 1731 µm in length with a mean diameter of 16 µm. Single particle analysis using µ-FTIR indicated a prevalence of Rayon, PP, Rayon/Nylon/Polyester blends, Rubber, PS, PE, PA, PVC, Acrylic, EMAA and PET. Fragments were mainly white in colour (46%) followed by brown (38%), black (1%), blue (1%) and orange (1%). Fibres were mainly white in colour (57%) followed by black (14%), orange (14%) and red (14%). A trend assessment at the UK regional seas levels indicated little visual evidence of any trends in the abundance of microplastics over time in any of the regional seas – with the possible exception of the Northern North Sea with a reduction in abundance over time for the time-period 2013-2021.

Preparation characterization and blood compatibility studies of silk fibroin/gelatin/curcumin injectable hydrogels.

Hydrogel is a three-dimensional structure that has the potential to absorb and retain water within the mesh of its porous network structure. Currently hydrogels made from natural biopolymers are preferred in the discipline of biomedical applications because of their blood compatibility, adhesion of platelets and protein binding, ease of administration and delivery of ingredients to the place of action. The aim of this work was to prepare a hydrogel from natural biopolymers and evaluate its blood compatibility, swelling nature, prolonged degradation and morphological features in order to further recommend its clinical use. To prepare hydrogels, different combinations of gelatin, dialyzed SF, curcumin and N, N methylene bisacrylamide (MBA) were evenly mixed on a magnetic stirrer. After an hour of the gelation process it was kept in a refrigerator at 4 °C. For the characterization and biocompatibility studies of hydrogel, the swelling test and biodegradation analysis, SEM, FTIR, invitro coagulation tests, total serum albumin and cholesterol level analysis were applied. Injectable hydrogels were successfully made with significantly correlated combinations of polymers. The analysis of physiochemical biocompatibility studies and morphological characterization were done effectively. The results of the study indicate that hydrogels made from natural biopolymers are a potential source and suitable matrices with excellent biocompatible nature acting as a useful device in delivering drugs.

Some Novel Formulas of Lucas Polynomials via Different Approaches

Some new formulas related to the well-known symmetric Lucas polynomials are the primary focus of this article. Different approaches are used for establishing these formulas. A matrix approach to Lucas polynomials is followed in order to obtain some fundamental properties. Particularly, some recurrence relations and determinant forms are determined by suitable Hessenberg matrices. Conjugate Lucas polynomials and generating functions are derived and examined. Several connection problems between the Lucas polynomials and other celebrated symmetric and non-symmetric orthogonal polynomials such as the first and second kinds of Chebyshev polynomials and their shifted counterparts are solved. We prove that several argument-type hypergeometric functions are involved in the connection coefficients. In addition, we construct new formulas for high-order derivatives of Lucas polynomials in terms of their original polynomials, as well as formulas for repeated integrals of Lucas polynomials.

Materials Selection of Thermoplastic Matrices of Natural Fibre Composites for Cyclist Helmet Using an Integration of DMAIC Approach in Six Sigma Method Together with Grey Relational Analysis Approach

Natural fibre reinforced polymer composite (NFRPC) materials are gaining popularity in the modern world due to their eco-friendliness, lightweight nature, life-cycle superiority, biodegradability, low cost, and noble mechanical properties. Due to the wide variety of materials available that have comparable attributes and satisfy the requirements of the product design specification, material selection has become a crucial component of design for engineers. This paper discusses the study’s findings in choosing the suitable thermoplastic matrices of Natural Fibre Composites for Cyclist Helmet utilising the DMAIC, and GRA approaches. The results are based on integrating two decision methods implemented utilising two distinct decision-making approaches: qualitative and quantitative. This study suggested thermoplastic polyethylene as a particularly ideal matrix in composite cyclist helmets during the selection process for the best thermoplastic matrices material using the 6σ technique, with the decision based on the highest performance, the lightest weight, and the most environmentally friendly criteria. The DMAIC and GRA approach significantly influenced the material selection process by offering different tools for each phase. In the future study, selection technique may have been more exhaustive if more information from other factors had been added.

Amorphization of cyclodextrins by spray drying for producing encapsulated functional gas powders for agri-food applications

Cyclodextrin (CD) powders are the most suitable solid matrices to encapsulate gases to produce gas powders in agri-food industries, where gases have been widely used to ensure processability, quality, functionality, safety, and stability of many products. The use of gases in powder form is much easier and safer than conventional means of gas utilization from pressurized cylinders or tanks. Gas powders are typically produced by crystallization from aqueous CD solutions under gas pressure, which is time consuming and results in low product yield. In amorphous structure, CD powders enable a rapid and 100% yield method to produce stable gas powders. However, most commercial CD powders exist in crystalline structure. In this review, we describe the amorphization of CD powders by spray drying, the properties of amorphous CD powders in comparison with its crystalline counterparts, gas encapsulation using amorphous CD powders, and applications of gas-CD powders in food and agriculture production.

Stability of Perovskite Light‐Emitting Diodes: Existing Issues and Mitigation Strategies Related to Both Material and Device Aspects

Metal halide perovskites combine excellent electronic and optical properties, such as defect tolerance and high photoluminescence efficiency, with the benefits of low-cost, large-area, solution-based processing. Composition- and dimension-tunable properties of perovskites have already been utilized in bright and efficient light-emitting diodes (LEDs). At the same time, there are still great challenges ahead to achieving operational and spectral stability of these devices. In this review, the origins of instability of perovskite materials, and reasons for their degradation in LEDs are considered. Then, strategies for improving the stability of perovskite materials are reviewed, such as compositional engineering, dimensionality control, defect passivation, suitable encapsulation matrices, and fabrication of core/shell perovskite nanocrystals. For improvement of the operational stability of perovskite LEDs, the use of inorganic charge-transport layers, optimization of charge balance, and proper thermal management are considered. The review is concluded with a detailed account of the current challenges and a perspective on the key approaches and opportunities on how to reach the goal of stable, bright, and efficient perovskite LEDs.

Cayley Hash Values of Brauer Messages and Some of Their Applications in the Solutions of Systems of Differential Equations

Cayley hash values are defined by paths of some oriented graphs (quivers) called Cayley graphs, whose vertices and arrows are given by elements of a group H. On the other hand, Brauer messages are obtained by concatenating words associated with multisets constituting some configurations called Brauer configurations. These configurations define some oriented graphs named Brauer quivers which induce a particular class of bound quiver algebras named Brauer configuration algebras. Elements of multisets in Brauer configurations can be seen as letters of the Brauer messages. This paper proves that each point (x,y)∈V=R\{0}×R\{0} has an associated Brauer configuration algebra ΛB(x,y) induced by a Brauer configuration B(x,y). Additionally, the Brauer configuration algebras associated with points in a subset of the form (⌊(x)⌋,⌈(x)⌉]×(⌊(y)⌋,⌈(y)⌉]⊂V have the same dimension. We give an analysis of Cayley hash values associated with Brauer messages M(B(x,y)) defined by a semigroup generated by some appropriated matrices A0,A1,A2∈GL(2,R) over a commutative ring R. As an application, we use Brauer messages M(B(x,y)) to construct explicit solutions for systems of linear and nonlinear differential equations of the form X″(t)+MX(t)=0 and X′(t)−X2(t)N(t)=N(t) for some suitable square matrices, M and N(t). Python routines to compute Cayley hash values of Brauer messages are also included.