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Bacterial nanocellulose (BNC) currently has emerged as a potential biopolymer that can be used for various industrial applications. However, the major concern is the limitation of the bacteria used for BNC production on a larger scale. This study aimed to isolate and identify potential nanocellulose-producing bacteria from pineapple wastes. In this study, 11 isolates were screened and the F1 isolate, which produced the highest BNC yield was chosen for 16S rRNA sequencing. Based on the 16S rRNA analysis, Comamonas terrae YSZ sp. (OQ592726.1) was the best BNC producer with 1.68 ± 0.19 g/L yield. The physicochemical characteristics from FESEM analysis revealed that C. terrae YSZ sp. produced amorphous BNC, with fewer nanofibrils. The XRD analysis showed that the BNC produced had a 19.3% of crystallinity index. To the best of our knowledge, this is the first work reporting the isolation of C. terrae YSZ sp. from pineapple wastes with more amorphous regions providing an interesting alternative for heavy metal removal potentials. [ABSTRACT FROM AUTHOR]

In the industrial application of bacterial cellulose (BC), the yield becomes a crucial factor because it drives the selling price of BC. A Box–Behnken experimental design with three components and three levels was employed to create seventeen samples. A response surface method was then used to optimize the BC yield from the most relevant parameters, including incubation temperature, medium shaking intensity, and nitrogen supply pH. Fourier transform infrared (FTIR) analysis proved that BC was pure. By analyzing BC morphology using scanning electron microscopy (SEM), rod-like microfibrils with an average diameter of 6.5 were revealed. X-ray diffraction (XRD) tested the crystalline size and crystallinity and found 4.7 nm and 69%, respectively. Thermal transition and stability were assessed using a differential scanning calorimeter (DSC) and a thermogravimetric analyzer (TGA). For the manufacture of BC composite hydrogel, a chemical test method was used to determine the solubility of BC. This study aimed to identify the ideal circumstances for using leftover sweet lime pulp for biomedical applications to produce reasonably priced and effective BC. At 28.87 °C, 125.91 rpm shaking frequency, and 5.65 pH, a sweet lime pulp waste medium produced the highest yield of BC, three times greater than the yield in a Hestrin–Schramm medium under static circumstances. [ABSTRACT FROM AUTHOR]

Zr-based bulk metallic glasses (BMGs) are characterized by excellent glass-forming ability, combined with superior mechanical properties. However, oxygen impurities degrade both these aspects as oxides serve as heterogeneous nucleation sites during solidification. Rare-earth elements (REEs) are known to be good oxygen scavengers, binding oxygen to less harmful forms. The most stable rare-earth oxide (REO) is M2O3, which occurs in three polymorphic forms, depending on the radius of metal cation: cubic, hexagonal, and monoclinic. Here, we show the effect of Sc, Y, Lu, Nd, and Gd additions in relation to the oxygen content on the glass-forming ability of the Zr52.5Cu17.9Ni14.6Al10Ti5 alloy. Microscopic observations (SEM) supported by chemical analysis (EDS, WDS), structure identification (XRD), and thermal analysis (DTA) were carried out. The critical diameter for glass formation (Dc) in the high oxygen alloy doped with cubic oxide-forming elements (Sc, Y, and Lu) can be even higher (Dc = 9 mm) compared to the undoped alloy synthesized from low oxygen components. Therefore, we have demonstrated that it is feasible to produce BMG using low-purity constituents with REE-based oxygen scavengers. This bridges the gap between laboratory development and cost-effective commercial applications. [ABSTRACT FROM AUTHOR]

The pathways of dehydration reaction of both calcium atorvastatin trihydrate (CAT) and grinded CAT were investigated using CRTA technique under controlled residual water vapor pressure of 5 hPa using complementary analysis techniques, namely TG, DSC and XRD. The results show that the studied sample is a pure atorvastatin in its trihydrated form and that, under CRTA conditions, it dehydrates in three separated steps between 261 and 393 K, each corresponds to the loss of one water molecule. On the other hand, the grinded CAT dehydrates in one step. From the duration of the CRTA experiment and the X-ray diffraction technique, we have showed that the grinding partially dehydrates CAT, to obtain calcium atorvastatin 1.5 H2O, while decreasing its crystallinity. Also, examination by X-ray diffraction technique of the CRTA final products of both, CAT and grinded CAT, showed that the anhydrous phase of CAT is crystallized, whereas the one of the grinded CAT is amorphous. The apparent activation energies corresponding to the dehydration steps of intact CAT (39 kJ mol−1 and 34 kJ mol−1) and grinded CAT (126 kJ mol−1 and 289 kJ mol−1) were obtained by means of two CRTA curves realized at two different reaction rates without any hypothesis on the kinetic model of the reaction. [ABSTRACT FROM AUTHOR]

In this work, Ca1−xCuxTiO3 samples (x = 0 (CTO), x = 0.04 (CCTO0.04) and x = 0.08 (CCTO0.08)) were synthesized via the sol–gel method. The influence of A-site copper substitution on the structural, optical, and dielectric properties of Ca1−xCuxTiO3 powders was investigated. X-ray diffraction (XRD) confirmed the formation of a pure perovskite structure. Moreover, Rietveld refinement revealed the crystallization of all samples under the orthorhombic Pbnm structure with the appearance of a minor secondary cubic phase with Cu2+ incorporation in the CaTiO3 host lattice. The vibrational investigation using Micro-Raman (MR) spectroscopy confirmed XRD results. Moreover, MR analysis revealed that A-site copper substitution results in the displacement of Ti atoms which induces distortions in the lattice. Ultraviolet–Visible (UV–Vis) absorption and photoluminescence (PL) measurements revealed the effect of copper-induced structural defects, distortions, and/or strains on the optical properties. Furthermore, the dielectric studies indicated high-temperature stability of the dielectric properties of the samples over a broad temperature range. The photoluminescence and dielectric results suggest that Ca1−xCuxTiO3 powders are promising materials for potential use in several electronic devices such as capacitors and light-emitting devices. [ABSTRACT FROM AUTHOR]

Objectives: To assess the probability of survival of crowns made with a 3Y-TZP, a 5Y-TZP, and a lithium disilicate. Materials and methods: CAD-CAM premolar crowns with occlusal thicknesses of 1.0 mm or 1.5 mm and cemented on a metal dye. Step-stress accelerated life testing (SSALT) was performed to access the use level probability Weibull curves and reliability were calculated for the completion of a mission of 100,000 cycles at 300 to 1200 N. Results: All ceramics showed a high probability of survival (87–99%) at 300 N, irrespective of thickness. 3Y-TZP shows no significant decrease in the probability of survival up to 1200 N (83–96%). Lithium disilicate presented lower reliability than zirconia under the 600 N mission. 5Y-TZP showed lower reliability than 3Y-TZP at 1200 N. There was no significant difference in the Weibull modulus (3.23–7.12). 3Y-TZP had the highest characteristic strength (2483–2972 N), followed by 5Y-TZP (1512–1547 N) and lithium disilicate (971–1154 N). Conclusion: Zirconia ceramics have a high probability of survival (up to 900 N-load), while lithium disilicate survives up to 300 N load only, irrespective of the thickness (1.0 mm or 1.5 mm). Clinical relevance: The probability of survival of posterior crowns made with zirconia ceramics resists extreme loads while glass ceramics resist normal chewing loads. In addition, crowns with thinner occlusal face showed sufficient mechanical behavior. [ABSTRACT FROM AUTHOR]

The increase in environmental consciousness has promoted the use of renewable resources. A tremendous spike has been observed in the use of products that decompose into environment-friendly constituents, which leads to the protection of the environment. Such environment-centric thinking has reduced the volume of solid waste generated by consumers every year, together with reuse and recycling. However, the environmentally friendly initiatives and regulations face a setback when the cost is high. Often the quality of such products is compromised in comparison with synthetically derived products for consumer usage. Plastic is a ubiquitous pollutant with potentially harmful effects on living beings. The increasing population and a steady increase in petrochemical plastics' demand hamper global plastic waste management. The use of bioplastics has helped us to overcome these issues. Poly(hydroxybutyrate) (PHB) is commonly known, first synthesized bioplastic, which has strong potential in replacing conventional plastics. This review focuses on the PHB biopolymer's significant properties over plastic, its application in different fields, i.e., medical science, agriculture, construction, packaging, energy, etc. It also covers PHB biosynthesis using different waste products as a substrate to minimize the production process cost, degradation, and different analytical methods to characterize the PHB. Along with these, we have also discussed about the other polysaccharide based biodegradable polymers. [ABSTRACT FROM AUTHOR]

Every year, all over the world, the industry generates huge amounts of residues. Side-streams are most often used as feed, landfilled, incinerated, or discharged into sewage. These disposal methods are far from perfect. Taking into account the composition of the side-streams, it seems that they should be used as raw materials for further processing, in accordance with the zero-waste policy and sustainable development. The article describes the latest achievements in biotechnology in the context of bacterial reprocessing of residues with the simultaneous acquisition of their metabolites. The article focuses on four metabolites — bacterial cellulose, propionic acid, vitamin B12 and PHAs. Taking into account global trends (e.g. food, packaging, medicine), it seems that in the near future there will be a sharp increase in demand for this type of compounds. In order for their production to be profitable and commercialised, cheap methods of its obtaining must be developed. The article, in addition to obtaining these bacterial metabolites from side-streams, also discusses e.g. factors affecting their production, metabolic pathways and potential and current applications. The presented chapters provide a complete overview of the current knowledge on above metabolites, which can be helpful for the academic and scientific communities and the several industries. Key points: • The industry generates millions of tons of organic side-streams each year. • Generated residues burden the natural environment. • A good and cost-effective method of side-streams management seems to be biotechnology – reprocessing with the use of bacteria. • Biotechnological disposal of side-streams gives the opportunity to obtain valuable compounds in cheaper ways: BC, PA, vitmain B12, PHAs. [ABSTRACT FROM AUTHOR]

The oxide glass–ceramics is a promising class of solid state materials because they are using thermally stable and chemically inert glass oxide matrices. Development of such efficient glass matrices suitable for creation of glass–ceramic materials for several purposes is an important practical task. The xLi2O–yV2O5–(100 − x − y)B2O3 undoped glass and 47Li2O–2V2O5–50B2O3–1La0.3Eu0.7VO4 glass samples with crystalline nanoinclusions were synthesized and investigated using XRD, IR and UV–Vis spectroscopy and UV band-to-band excitation of luminescence. The synthesized glass samples are characterized by wide band photoluminescence emission with maximum at 570 nm and intensity increased with increase of Li2O concentration. The excitation spectra consist of three bands with maxima located at 270, 320 and 365 nm. The observed concentration dependencies of spectral distributions in the absorption and excitation spectra are explained by influence of the lithium ions on a ratio between triborate and tetraborate groups in the glass networks. The assumption is made that the observed wide band photoluminescence emission of the glass matrix can appear as a result of recombination processes between the defects in borate networks and the broken vanadate groups. The crystalline component in the doped glass samples is found to not affect the luminescence properties of the glass matrix. Intensity of narrow band photoluminescence emission of the crystalline component is up to 10 times more intense than that of the glass matrix wide band emission. The synthesized type of the glass matrices has promising characteristics for the use of developed materials in lighting devices, as it allows improving the spectral distribution of light emission towards the white light. [ABSTRACT FROM AUTHOR]

Neodymium doped Bismuth Ferrite (Nd-BFO) samples, synthesized using solid-state reaction route are subjected to various structural and dielectric characterization to investigate the influence of Nd3+ ions in modifying bismuth ferrite multiferroic properties. Structural characterizations including XRD, FESEM, FTIR, and Raman characterization have shown that higher amount of dopant concentration has caused disruption in the structural ordering. Dielectric studies such as dielectric constant, loss, measured using an LCR meter with respect to the temperature and frequency variations are analyzed in this paper. Further electrical characterization such as impedance analysis is also presented. All these results broadly indicate the tunable electrical nature of these samples at different temperatures and frequencies, with doping, which is a correlation to their structural and morphological ordering and low concentration doped Nd-BFOs only possess the potential for applications. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) techniques such as laser powder bed fusion (LPBF) and directed energy deposition (DED) are viable methods to produce large-size bulk metallic Glass (BMG) components. Even though BMGs with low glass forming abilities (GFA) can potentially be manufactured via AM, the resultant build undergoes partial devitrification, structural relaxation, cracking, or picks up oxygen (O). O pick-up is a serious issue for AM fabricated BMGs as it causes embrittlement and affects its potential use as a structural material. Here, a detailed review of the O pick-up in BMGs during AM fabrication is provided. The effect of O on the propensity of crystal nuclei formation and the glass forming ability of BMGs is critically discussed. Thereafter, the effect of on the mechanical properties of BMGs, and how it affects its structural performance are reviewed. Above a certain threshold, which could be composition-specific, O improves the strength of the BMG but diminishes its fracture, fatigue, and plasticity. These discussions will lead to the formulation of some future directions of research in AM fabrication of BMGs that have both scientific and technological relevance. [ABSTRACT FROM AUTHOR]

We investigate the direct and indirect effects of silica nanoparticles, NP, on the molecular mobility and crystallization of a series of polymer nanocomposites, PNCs, based on polylactide, PLA. To that aim, a sum of complementary techniques was employed, namely infrared spectroscopy, calorimetry, dielectric spectroscopy, X-ray diffraction, polarized and electron microscopy. The introduction of NPs was found to result in formation of interfacial interactions, an in general moderate elevation of the glass transition temperature and a suppression of the chains fragility/cooperativity. Regarding crystallinity, neither the unfilled PLA nor the PNCs were found to crystallize during cooling from the melt state, whereas all samples crystallize upon heating (cold crystallization), suggesting that the initially slow crystallization and poor nucleation of the used PLA was not improved. The degree of crystallinity upon the addition of NP is also suppressed. Surprisingly, severely more active nuclei were recorded in the PNCs. This is interpreted in terms of the indirect effect of slowing down of the chains' diffusion related to the NP-polymer interaction. This results in slower crystals' growing around more PLA-nuclei in PNCs as compared to the unfilled matrix, within which the antagonistic crystal growing is faster and dominant around less nuclei. This is also manifested by altered crystals structuring in terms of crystals with smaller size and lower density. Regarding local dynamics, the local β relaxation screening the dipolar motions arising from the crankshaft motion of the backbone ‒C=O was recorded to follow, on the one hand, the formation of interfacial interactions via the suppression of its strength and, on the other hand, to be sensitive to large scale phase changes (glassy to rubbery). Finally, an additional relaxation process was recorded in the highly loaded PNCs and assigned to modified PLA mobility. [ABSTRACT FROM AUTHOR]

Cellulose, the most abundant polysaccharide on earth, can be obtained from various sources including the cell wall of plants and woods, bacteria, algae, and tunicates. However, the cellulose obtained from bacteria known as bacterial cellulose or bacterial nanocellulose (BC) has gained major popularity due to its simple production process, non–toxicity, high purity, and biocompatibility. Furthermore, the BC holds distinct properties like higher crystallinity, larger surface area, high porosity, great water holding capacity, and enhanced tensile strength. These unique features of BC further widen its application in several areas including drug delivery, tissue engineering, wound dressing, etc. The present review summarizes the recent developments in BC production and its biomedical applications. Firstly, the microorganisms involved, various medium compositions used and the methods adopted for BC production are discussed, and then reactors used for industrial production of BC are introduced. Subsequently, the applications of BC in tissue engineering, drug delivery system, and pharmaceutical & medical sectors are discussed in detail. Finally, the future perspective of BC in biomedical applications is discussed in brief. [ABSTRACT FROM AUTHOR]

China is the third largest sugar producer in the world. However, the sugar industry is challenged by high production costs (attributed to the high cane supply price), which lead to continuous financial deficits for sugar companies. Currently, sugarcane products are primarily composed of white sugar and non-centrifugal sugar (NCS); the utilization of sugarcane by-products (i.e. bagasse, filter mud, and molasses) has also been partially industrialized. However, these strategies are far from adequate to address the challenge. China has successfully developed an innovative sugar manufacturing process using nano-ceramic membrane technology to overcome this predicament. In addition, concepts of high-value diversification of sugarcane products and value-added utilization of industrial by-products have been proposed. A series of sugarcane-based products, e.g. NCS produced by nano-ceramic membrane technology (MNCS), sugarcane-based beverages, plant water, and cultivation substrates, have been developed to improve the overall return of sugar enterprises. Thus, this paper mainly summarizes the diversification of sugarcane products and their development opportunities in China. [ABSTRACT FROM AUTHOR]

Glass-forming alloys are very sensitive to oxygen contaminations. Here, the oxygen-scavenging effect of five rare-earth elements (REEs) was studied when added to the Zr50Cu40Al10 alloy, synthesized from commercially available zirconium. The effects of precise REEs additions (Y, Sc, Lu, Gd, Nd) with respect to the measured oxygen content, based on the stoichiometric relationship in the M2O3 oxide, are reported. Additionally, the influence of double and triple REE-to-oxygen ratios on the critical diameter (Dc) and other glass-forming ability (GFA) indicators were investigated. To evaluate the GFA and phase transformations during heating, differential thermal analysis was performed along with neutron diffraction. The combination of these two techniques allowed to identify crystallization products and distinguish the differences in phase transformations of low and high-oxygen-content alloys. Microstructural analysis was carried out by means of electron microscopy (SEM, STEM), supported by X-ray diffraction. The best oxygen scavengers were found to be rare earths that form cubic sesquioxides, i.e., Y, Sc, and Lu, allowing to increase Dc in the high-oxygen Zr50Cu40Al10 alloy from 2.5 mm up to 8 mm (double-stoichiometric concentration of Y-to-oxygen). Our results indicate that low-purity alloys can be easily vitrified, highlighting their potential for wide commercialization. [ABSTRACT FROM AUTHOR]

Bismuth sulfide (Bi2S3) nanorods have been prepared using a simple and low-cost reflux method. This method is easy to handle and opens up a way to manufacture photocatalytic pigment at a low cost. The Bi2S3 catalyst was subjected to X-ray diffraction (XRD), UV–Visible spectroscopy (UV–Vis), scanning electron microscope, high-resolution transmission electron microscopy, FT-IR spectroscopy, thermogravimetric analysis (TG/DTA), and X-ray photoelectron spectroscopy. The structures of the Bi2S3 nanorod have been investigated and were seen to be orthorhombic. The electron microscopic observations showed that surfactants greatly affect the morphologies of the as-prepared Bi2S3 samples. The XRD and TEM results confirmed that the Bi2S3 nanorods have a high surface area and are good crystallinity. TEM measurements revealed that the average breadth and length is 75 nm and 385 nm for Bi2S3 nanorods prepared using NaOH. The uniform one-dimensional Bi2S3 nanorods are due to the presence of NaOH which controls the nucleation and growth process of Bi2S3 nanorods. The photocatalytic activity of the Bi2S3 nanocrystallites has been estimated by the degradation of methylene blue (MB) under the irradiation of halogen light. It was noted that the absorption peak corresponding to MB reduced indicating the photocatalytic nature of the sample. In these conditions, the maximum degradation of the dye was achieved within 140 min for KOH added Bi2S3 samples and the photodegradation efficiency is 87.98%. A possible photocatalytic reaction mechanism of the Bi2S3 samples has also been proposed. [ABSTRACT FROM AUTHOR]

Objectives: The effect of toothbrushing on the color, relative translucency, and surface roughness of extrinsically stained zirconia dental restorations is still unclear. The purpose of the present study was to evaluate the optical properties and surface textures of extrinsically stained or glazed partially stabilized zirconia with 5 mol% yttria (5Y-PSZ) after toothbrushing by determining changes in the color, translucency parameter (TP), and surface roughness. Materials and methods: Specimens (2 mm thick; n = 50) were sectioned from 5Y-PSZ blanks. Three brands of powdered stains (namely VI, SH, IV) and a glaze (GL) were used to extrinsically stain the specimen surfaces (n = 10 per group). The specimens were subjected to 10,000–50,000 simulated toothbrushing strokes using a toothpaste slurry (Ora2 PREMIUM Stain clear paste). The color parameters were measured before staining or glazing and before and after simulated brushing. The color changes and TP values can be calculated before and after simulated brushing. The surface roughness was also evaluated. Results: Significant changes were found in the shade and TP values of 5Y-PSZ after extrinsic staining, but no significant changes were found after toothbrushing, irrespective of the staining brand (p > 0.05). The surface roughness of the characterized 5Y-PSZ specimens decreased after toothbrushing, whereas that of the non-characterized 5Y-PSZ group increased. Conclusions: Toothbrushing markedly affects the surface roughness of extrinsically stained or glazed 5Y-PSZ specimens, whereas no impacts on the color or translucency were observed. Clinical relevance: For esthetic reasons, clinicians and dental technicians prefer to apply extrinsic stains to zirconia restorations, which profoundly affects its appearance. The limited influence of toothbrushing on color and translucency of 5Y-PSZ is promising for clinical applications. [ABSTRACT FROM AUTHOR]

The effects of molecular weight (Mw) and content of poly(vinyl acetate) (PVAc) on the crystallization behaviors, competing crystallization of homocrystallites and stereocomplex crystallites (SCs), crystalline structure, and mechanical properties of poly(L-lactic acid) (PLLA)/poly(D-lactic acid) (PDLA) blends were investigated. The crystallization of PLLA/PDLA component is accelerated after the addition of low-Mw PVAc and is suppressed with high-Mw PVAc. The ability of SC formation is enhanced via blending with PVAc, irrespective of its Mw, and becomes prominent with low-Mw PVAc. The exclusive SCs are obtained in the blends with 30 mass % low-Mw PVAc. The improvement in thermomechanical property above 170 °C is ascribed to the enhancement of SC content. This work presents guidance for achieving the melt processability of SC-PLA, thus proving their potential as a high-performance substitute for conventional plastics. [ABSTRACT FROM AUTHOR]

Type 2 diabetes, Body weight, Telemedicine, Lockdown, HbA1c Keywords: Type 2 diabetes; Lockdown; HbA1c; Body weight; Telemedicine EN Type 2 diabetes Lockdown HbA1c Body weight Telemedicine 281 284 4 02/15/22 20220201 NES 220201 Introduction The lockdown measures for COVID-19 could interfere with the management of diabetes. [Extracted from the article]

Cocrystallization is a very efficient strategy to improve the physicochemical properties of bioactive agents. A new norfloxacin (NOR)–saccharin cocrystal and a cocrystal–solvate were synthesized through the mechanochemical method (neat and liquid-assisted grinding), and the characterization was performed by thermal analysis (TG–DTA, DSC and DSC microscopy), infrared vibrational spectroscopy and powder X-ray diffraction. Moreover, solubility experiments carried out in water and buffer solutions (pH 3.0, 6.1 and 8.5) showed that norfloxacin has an aqueous solubility 3.5 times higher when cocrystallized with saccharin than in its pristine state, and an inverted pH-dependency compared to NOR alone (2 times higher in 6.1, slightly increase in pH 3.0, and a decrease of 0.7 times in 8.5 buffer solution). Furthermore, the solvate–cocrystal has a water solubility 2.3 times higher than NOR and the same solubility in 6.1 buffer solution than the cocrystal (2 times higher than NOR alone). [ABSTRACT FROM AUTHOR]

Objective: To investigate the influence of different finishing/polishing techniques and in situ aging on the flexural strength (σ), surface roughness, and Candida albicans adherence of 5 mol% yttria-stabilized zirconia (ultratranslucent zirconia). Materials and methods: A total of 120 zirconia bars (Prettau Anterior, Zirkonzahn) with dimensions of 8 × 2 × 0.5 mm were divided into 8 groups (n = 15) according to two factors: "in situ aging" (non-aged and aged (A)) and "finishing/polishing" (control (C), diamond rubber polishing (R), coarse grit diamond bur abrasion (B), and coarse grit diamond bur abrasion + diamond rubber polishing (BR)). Half of the samples from each group were subjected to a 60-day in situ aging by fixing the bars into cavities prepared in the posterior region of the base of complete or partial dentures of 15 patients. The samples were then subjected to the mini flexural (σ) test (1 mm/min). A total of 40 zirconia blocks (5 × 5 × 2 mm) were prepared and subjected to roughness (Ra) analyses and fungal adherence and complementary analyses (X-ray diffraction (XRD) and scanning electron microscopy (SEM)). The data of mean σ (MPa) and roughness Ra (μm) were statistically analyzed by two-way and one-way ANOVA, respectively, and Tukey's test. The Weibull analysis was performed for σ data. The fungal adhesion (Log CFU/mL) data were analyzed by Kruskal–Wallis tests. Results: For flexural resistance, the "finishing/polishing" factor was statistically significant (P = 0.0001); however, the "in situ aging" factor (P = 0.4458) was not significant. The non-aged (507.3 ± 115.7 MPa) and aged (487.6 ± 118.4 MPa) rubber polishing groups exhibited higher mean σ than the other techniques. The non-aged (260.2 ± 43.3 MPa) and aged (270.1 ± 48.8 MPa) bur abrasion groups presented lower σ. The coarse-grit diamond bur abrasion group (1.82 ± 0.61 µm) presented the highest roughness value (P = 0.001). Cell adhesion was not different among groups (P = 0.053). Group B presented the most irregular surface and the highest roughness Ra of 0.61 m. Conclusions: The finishing of ultratranslucent zirconia might be preferably done with a diamond rubber polisher. Moreover, the protocols used did not interfere with Candida albicans adhesion. Clinical relevance: Coarse-grit diamond burs might be avoided for finishing ultratranslucent monolithic zirconia, which might be preferably performed with a diamond rubber polisher. [ABSTRACT FROM AUTHOR]

This study investigates the use of CaO–TiO2 mixed oxides as solid base catalysts to produce biodiesel from cotton oil (Gossypium hirsutism). These CaO–TiO2 mixed-oxide catalysts were prepared in different molar proportions of Ca:Ti (0.75Ca:0.25Ti, 1Ca:1Ti e 0.25Ca:0.75Ti) and characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TGA), Raman spectroscopy, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray analysis, and Brunauer–Emmett–Teller surface area analysis. The effects of reaction parameters such as the methanol/oil molar ratio, the amount of catalyst amount, and the reaction temperature were also investigated. The process was evaluated by TGA and confirmed by FTIR and GC/MS. The catalysts obtained were tested in the following reaction parameters: 20:1 methanol:oil molar ratio; 10% of catalyst amount; and 60 °C temperature for 5 h. The best catalyst was determined to be 0.25Ca–0.75Ti (calcined at 800 °C), considering its catalytic and anti-leeching abilities, because it obtained the highest yield (92.2%) without leaching calcium. Therefore, CaO–TiO2 catalysts have the potential to be used in biodiesel products. [ABSTRACT FROM AUTHOR]

The Sol–gel spin-coating method was used to deposit Bismuth Ferrite (BiFeO3) and Mn-substituted BiFeO3 (BiFe1−xMnxO3) thin films on glass substrates. The powder XRD data of the grown BiFeO3 thin films indicated a distorted rhombohedral structure. The powder XRD data of the Mn-substituted BiFeO3 thin films indicate the change of crystal structure from distorted rhombohedral to orthorhombic. FESEM and AFM imaging were used to investigate the surface morphology and topography of the grown thin film samples. The UV–visible absorption studies BiFe1−xMnxO3 thin films that show an increase in optical absorption as the Mn substitution increases in the films, and correspondingly, the UV–visible transmittance of the films decreases with an increase in Mn substitution. The optical bandgap obtained from the UV–visible optical absorption of spectra of the BiFe1−xMnxO3 thin films was found to decrease with an increase in Mn substitution. The FTIR absorption band with maximum absorption around 550 cm−1 indicates the formation of BiFe1−xMnxO3. The Raman spectra of the samples recorded over the range of 200–800 cm−1 confirm the formation of BiFe1−xMnxO3. The magnetic hysteresis (M–H) loops of the BiFe1−xMnxO3 thin films were measured with a magnetic field up to 70 kOe at 10 K and room temperature using a SQUID magnetometer. The room temperature M–H loops of the sample show weak ferromagnetism and the 10 K M–H loops show superparamagnetic behavior. [ABSTRACT FROM AUTHOR]

Introduction: To investigate the effect of preexisting treatment with dipeptidyl peptidase-4 inhibitors (DPP-4is) on COVID-19-related hospitalization and mortality in patients with type 2 diabetes mellitus (T2DM). Methods: A multicenter, retrospective cohort study was conducted using patient data extracted from the Turkish National Electronic Database. All patients who tested positive for COVID-19 (PCR test) between 11 March through to 30 May 2020 were screened for eligibility (n = 149,671). Following exclusion of patients based on pre-determined inclusion criteria, patients with T2DM using a DPP-4i or glucose-lowering medications other than a DPP-4i were compared for mortality and hospitalization. The propensity score method was used to match age, gender, micro- and macrovascular complications, and medications in the two groups. Independent associates of mortality were analyzed using multivariable analysis on the whole T2DM population. Results: A total of 33,478 patients with T2DM who tested postive for COVID-19 who met the inclusion criteria were included in the analysis. Median (interquartile range) age was 54 (22) years and 42.4% were male. Of these, 9100 patients using DPP-4is (n = 4550) or other glucose-lowering drugs (n = 4550) were matched in two groups. After matching, analysis revealed a lower mortality in the DPP-4i group (9.5 vs. 11.8%; p < 0.001). In the multivariable model, the use of DPP-4is (odds ratio [OR] 0.57, 95% confidence interval [CI] 0.35–0.91; p = 0.02) was associated with lower mortality in the whole sample, while age, male gender, computed tomography finding of COVID-19, obesity, low glomerular filtration rate, and an insulin-based regimen also predicted increased risk of death. There was no association between the preexisting treatment with DPP-4is and COVID-19-related hospitalization in the matched analysis or multivariate model. The rate of admission to the intensive care unit and/or mechanical ventilation favored the DPP-4i group (21.7 vs. 25.2%; p = 0.001), although this association became saturated in the multivariate analysis (OR 0.65, 95% CI 0.39–1.08; p = 0.099). Conclusions: The results of this study demonstrate an association between DDP-4i use and reduced mortality in people with T2DM who tested PCR positive for COVID-19. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of grinding on some surface properties of two lithium disilicate-based glass-ceramics, one experimental new product denominated LaMaV Press (UFSCar-Brazil) and another commercial known as IPS e-max Press (Ivoclar), in the context of simulated clinical adjustment. Discs (N = 24, 12 mm in diameter) were separated into four groups: LaMaV Press with no grinding (E), LaMaV Press after grinding (EG), IPS e-max Press with no grinding (C), and IPS e-max Press after grinding (CG). A 0.1-mm deep grinding was carried out on EG and CG samples (final thickness of 1.4 mm) using a diamond stone in a low-speed device. The E and C samples had the same thickness. The effect of grinding on the sample surfaces was evaluated by X-ray diffraction, mechanical and optical profilometry, scanning electron microscopy, goniometry, and Vickers hardness. The mean roughness (Ra) was evaluated by Kruskal–Wallis and Student–Newman–Keuls statistics. The surface energy (SE) by the sessile drop method and Vickers hardness (VH) were analyzed using two-way ANOVA. The Ra medians were E = 1.69 µm, EG = 1.57 µm, C = 1.45 µm, and CG = 1.13 µm with p = 0.0284. The SE and VH were similar for all materials and treatments. Grinding smoothed the surfaces and did not significantly alter the hardness and surface energy of both LaMaV Press and IPS e-max Press. These glass-ceramics presented similar surface properties, and clinical adjustments can be implemented without loss of performance of both materials. [ABSTRACT FROM AUTHOR]

Purpose: Less local availability and higher skin permeation restrict wide application of silver sulfadiazine (SSD) formulations against infectious burn wound. Aim: We aimed to develop β-cyclodextrin inclusion complex-based in situ pluronic gel of SSD (β-CD-ssd P-Gel). Methods: Formation of inclusion complex was confirmed by FT-IR, DSC, SEM, and XRD and checked for improved solubility. Results and Discussion: Poloxamer (407/118)-based in situ gel of inclusion complex was prepared and characterized for its gelation temperature (33.50 °C), viscosity (1159.25 ± 5.60 cps), pH (6.4 ± 0.56), and drug content (91.56 ± 1.62%). The developed gel showed slow drug release and slow permeation of the drug through the skin. It showed broader zone of Staphylococcus aureus growth inhibition (31 ± 0.20 mm) and high wound contraction (98.89%) when compared with the marketed formulation (26 ± 0.20 mm and 58.00%, respectively). Conclusions: A consistent, biocompatible, β-CD-ssd P-Gel was prepared successfully. It was found able to ensure increased local availability by forming viscous gel below body temperature, high SSD availability at the desired site, and high efficacy against infectious wound. [ABSTRACT FROM AUTHOR]

Microwave combustion technique (MCT) was used to synthesize of spinel Ni1-xSrxFe2O4 (x = 0.0, 0.1, 0.3 and 0.5) nanoparticles (NPs) by employing the fuel L-arginine. The physical characteristics of the as-prepared NPs were obtained by following methods, viz., powder X-ray diffraction (XRD), high-resolution scanning electron microscope (HR-SEM), energy-dispersive X-ray (EDX), UV-visible diffuse reflectance spectra (UV-Vis DRS), Fourier-transform infrared spectra (FT-IR), and vibrating sample magnetometer (VSM) techniques. The diffraction studies revealed that the average crystallite size exists in the band of 14.25 to 27.52 nm. The HR-SEM pictures revealed the agglomerated and spherical morphology of spinel Ni1-xSrxFe2O4 (x = 0 to 0.5) nanoparticles. Elemental analysis ensured the existence of Ni, Sr, O, and Fe ions. The energy band gap of the NPs was observed to exist in the range of 2.95 to 3.39 eV upon varying the concentration of Sr2+ dopant. The broad peaks at 437 cm−1 and 582 cm−1 correspond to octahedral (B-) metal stretching (Ni-O) and tetrahedral (A-) metal stretching (Fe-O) of nickel ferrite respectively. Magnetic results revealed that the prepared NPs are ferromagnetic in nature. The antibacterial activity (ABA) of gram-positive Staphylococcus aureus and Bacillus subtilis and gram-negative Escherichia coli and Klebsiella pneumonia has been investigated using pure and Sr2+-substituted NiFe2O4 NPs. It was found that the improved activity is intensified with smooth Sr2+ doping as it causes a decrease in the grain size. [ABSTRACT FROM AUTHOR]

The microwave combustion process (MCP) is used to synthesize Mg1-xCaxFe2O4 (0 ≤ x ≤ 0.5) spinel nanoparticles using the fuel l-arginine. Synthesized samples were examined by employing techniques such as XRD, HR-SEM, EDX, DRS-UV, TG-DTA and VSM. The XRD corroborated the constitution of the cubic spinel structure and the average crystallite size was valued to lie in the range of 16.09 to 33.10 nm. The morphology of the Mg1-xCaxFe2O4 (0 ≤ x ≤ 0.5) spinel nanoparticles was observed by HR-SEM. EDX studies confirmed the formation of spinel ferrite structure. Further bandgap values were estimated to be in the range of 1.84 eV to 2.00 eV. TG-DTA studies confirmed weight loss and exothermic transitions. The M-H loops exhibited ferromagnetic behaviour. [ABSTRACT FROM AUTHOR]

The present investigation reports, the bacterial cellulose (BC) a high-purity polymer produced from isolated strain ZKE7. BC production was optimized by Plackett–Burman and central composite designs yielding 18.5 g/l BC with a 4.5-fold enhancement. BC composites functionalized with antibiotics, BC-gelatin hydrogel, BC-Chitosan hydrogel and BC silver nanoparticle composites were developed and evaluated for water retention capability, moisture content and protein adsorption. The drug release behavior of the composites was consistent for controlled drug delivery. Composites were assessed for functional characteristic such as antimicrobial properties. BC composites functionalized with Neotericine exhibited antifungal activity against Candida albicans. Other composites showed pronounced antibacterial properties against Escherichia coli, Bacillus subtilis and Micrococcus luteus. Structural and thermal characterization of BC composites was carried out by FTIR, SEM with energy dispersive X-ray analysis, TGA and differential scanning calorimetry analysis. The results reveal high BC production with excellent properties that can be employed in biomedical field. [ABSTRACT FROM AUTHOR]

A set of glass samples with composition based on ternary 50P2O5–30Na2O–20ZnO (PNZ) matrix doped with different MnO contents was prepared via melt-quenching technique. Thermal, structural and spectroscopic properties were investigated by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Raman spectroscopy, UV–visible absorption, photoluminescence (PL) and by electron paramagnetic resonance (EPR) using Mn2+ as probe. Glass compositions (100-x)PNZ:xMn (0.01 ≤ x ≤ 1.0 in mol% of MnO) were characterized as glasses after careful analysis of the thermal and structural data. While DSC curves show the presence of the glass transition phenomenon (Tg), XRD analysis identified the non-crystalline arrangement, compatible with glass structure. Raman spectra of PNZ:xMn samples showed that the successive increase in Mn2+ content leads to rise of vibrational modes assigned to phosphate Q1 units, suggesting the breakdown of phosphate glass network chains. UV–Vis absorption spectra of glasses presented absorption bands centered at 250, 318, 341, 358 and 408 nm attributed to the Mn2+ electronic transitions. Glass samples containing above 0.06 mol% of MnO presented a broadband absorption centered at 511 nm assigned to the presence of traces of Mn3+. Additionally, UV–Vis, PL and EPR data showed that Mn2+ ions are occupying octahedral arrangements. Besides, EPR results suggest that the increase in MnO concentration influences on the EPR signal and hyperfine splitting constant suggests the presence of a moderately ionic bond between Mn2+ and PNZ glass network. [ABSTRACT FROM AUTHOR]

The coacervation process of Graham's Salt Na(PO3)n enabled the preparation of polyphosphate coacervates (CPPs) by adding different metallic ions (Mn+), and/or low-molecular-weight solvents at a specific solution, which resulted in a phase separation. The more viscous phase is termed as CPP and the less viscous one is the supernatant. CPPs have been extensively studied in recent years as a glass precursor at room temperature. Preparation at room temperature allows the preservation of the physicochemical properties of a wide range of active principles that may be used in controlled drug-delivery systems. Despite the present limitations of CPPs in terms of high hygroscopicity, this vulnerability to water is considered one of the great advantages of this material regarding applications in the controlled release of drugs and tissue engineering. Thus, in the presence of water, CPPs will dissolve in calcium and phosphate ions, which are the major inorganic constituents of bone and hydroxyapatite (HAP). It is believed that, in contact with body fluids, CPPs will degrade and, as this process occurs, they will be replaced by HAP. Therefore, CPPs configure a potential biomaterial that offers excellent properties with a wide range of biomedical applications that will be discussed and reviewed in this paper, including the structural properties and the recent improvements of materials based on CPPs and related devices. Highlights: The Polyphosphates Coacervates (CPPs) can be used as soft Glass-Materials precursors. The coacervation process of polyphosphate solution enables the preparation of CPPs. CPPs are biocompatible and allow the development of biomedical and pharmaceutical materials. CPPs can be applied in drug delivery systems and radiopaque resorbable. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) membrane can be architected to covalently immobilize biomolecules, generating materials with new functionality. The processes of purification (via alkaline treatment) and chemical modification (via NaIO4) to the wet BC membrane is the innovation of this work. This wet oxidized BC (OxBC) membrane could act as a support matrix for covalent immobilization of enzymes. BC produced over 5 days of static fermentation, followed by purification with K2CO3 (BC-5d-K2CO3) was selected for our study due to high porosity and surface area, which are properties that favor its chemical modification. This wet BC membrane proven suitable for NaIO4 oxidation. Time and temperature conditions were evaluated in the oxidation reaction, with oxidation BC (OxBC) performed at 1% (w/v) NaIO4 for 6 h at 55 °C under most advantageous conditions, as it provided 50% oxidation degree and preserved its morphological structure. BC and OxBC were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Scanning electron microscopy, mechanical test, and thermal analysis. The oxidation reaction decreased BC crystallinity, tensile strength, and thermal stability and compacted the cellulose layers. BC and OxBC showed non-cytotoxicity. Fourier transform infrared confirmed that OxBC can covalently immobilize papain and that after immobilization the enzyme showed a recovered enzymatic activity of 93.1%. In addition, the oxidized membrane presented greater amount of immobilized papain in its study than BC, proving to be a more efficient support for enzymatic immobilization. [ABSTRACT FROM AUTHOR]

Castor oil is an environmentally friendly alternative to hydrocarbon-based feedstocks for the synthesis of polyurethanes due to its major constituent, ricinoleic acid. This work aimed to obtain and characterize castor oil-based polyurethane (coPU) systems containing domperidone and verapamil hydrochloride, separately, as model drugs. The drug-loaded coPU systems were obtained by solvent evaporation method and were characterized by differential scanning calorimetry, thermogravimetry, Fourier transform infrared spectroscopy and X-ray powder diffraction. Additionally, dissolution studies and scanning electron microscopy were performed. Verapamil hydrochloride was successfully incorporated in coPU, once it interacted through hydrogen bonds, and this system showed as a potential candidate for sustained drug release. Domperidone precipitated during solvent evaporation, resulting in a drug suspension into the polymer matrix. However, around 20% of domperidone interacted chemically with the polymer by the reaction of the active hydrogen of domperidone imidazole groups with the terminal isocyanate of the prepolymer. Finally, the drug release profile is guided by the drug–polymer physicochemical interaction, which will depend on the drug and polymer functional groups that are stereochemically available. [ABSTRACT FROM AUTHOR]

Bacterial nanocellulose (BNC) and two BNC-based composites with carboxymethyl cellulose or hydroxyethyl cellulose (BNC-CMC or BNC-HEC, respectively), were produced in situ by Komagataeibacter xylinus E25 under stationary conditions and plasticized with glycerol (ex situ modification). The BNC-CMC composite had the loosest structure (visible in SEM images) and was less crystalline (CI of 88.6%) than BNC (CI of 92.9%) and BNC-HEC (CI of 90.4%). Cellulose fibers synthesized by K. xylinus E25 in the presence of HEC were thinner in comparison to the fibers of control BNC while there was no difference in the fibers width between the BNC-CMC and control BNC. The glycerol-plasticized BNC, BNC-CMC and BNC-HEC membranes were flexible after drying, and absorbed high amounts of artificial exudate and water after rehydration. BNC-CMC treated with 2.5% v/v aqueous glycerol was characterized by the greatest free swell absorptive capacity (up to 19 g artificial exudate/g dry weight in 24 h) while the highest rehydration capacity (around 96% of the initial water content) was observed in case of BNC-CMC plasticized with 10% v/v glycerol and dehydrated. The in situ and ex situ modifications of BNC affected also the tensile strength. The highest values of tensile strength at break (around 152.2 N) and Young's modulus (around 290.3 MPa) were observed in case of the BNC-CMC composite plasticized with 2.5% v/v glycerol. The impact of plasticized BNC, BNC-CMC and BNC-HEC on the viability of HaCaT keratinocytes was also studied and found to be positive at glycerol concentrations up to 2.5% (v/v) that suggests their potential utility as wound dressings. [ABSTRACT FROM AUTHOR]

Economic, social and environmental factors have led many industries to find new and attractive ways of waste management. Clean biotechnology is an integrated platform for the conversion of wastes into valuable and less toxic end products. Bacterial cellulose (BC) has a long history of its use as an important biomaterial for various applications. However, the potential for its industrialization and commercialization at large scale is still a challenge due to high fermentation cost, low productivity and expensive culture media. To overcome this problem, low-cost substrates and large waste biomass byproducts of various industries have been evaluated for BC production. Of these, tons of wastes produced from the agro, food, brewery and sugar industries, lignocellulosic biorefineries, textile and pulp mills are ideal raw materials for BC production. Recently, various studies have reported the wastes from these industries as a source of various nutrient for the low cost production of BC. This review is centered on BC production from low cost substrates with a major focus on the wastes from agro, food, brewery, sugar industries, lignocellulosic biorefineries, textile and pulp mills. Moreover, recent research trends and commercial media available for BC production are also discussed. This review also discuss briefly the properties and applications of BC. This article would likely draw the attention of researchers towards utilization of industrial wastes as potential alternate media for the production of BC. [ABSTRACT FROM AUTHOR]

A series of Ni-modified Mo2C catalysts with La2O3-stabilized ZrO2 supports were synthesized via template method coupled with incipient wetness impregnation and temperature-programmed carbonization. The catalyst was tested in dry reforming of methane (DRM) reaction at the temperature range from 973 to 1173 K in a fixed-bed quartz reactor under atmospheric pressure. XRD, Raman, BET, H2-TPD, SEM, EDS and TEM were conducted to characterize the phase constitution, the pore structure, the morphology and the crystal structure of the catalysts. Ni-Mo2C nanoparticles of ~ 3 nm diameter were obtained for these catalysts, and the La2O3-ZrO2 supports exhibited a cubic lattice structure with a sheet shape, which is believed to contain an abundant of oxygen vacancies. And the synergistic interaction between the oxygen vacancy in La-Zr-O solid solution and the Ni-Mo2C particles could decrease the apparent activation energy of CO2. Both of them are beneficial for accelerating DRM reaction. CH4 conversion of the best specimen catalyst reaches 94% at 1173 K, and the catalyst maintains its stability after 100-h reaction. The superior catalytic activity of NMLZ-7.5 is attributed to the improved BET surface area (33.2 m2/g), smaller crystallites, grain boundaries and oxidation-carbonization cycle of Ni-Mo2C. [ABSTRACT FROM AUTHOR]

A detailed study of the structural, morphological, optical, and electrical properties of the spin-coated Ga-doped ZnO (GZO) films in which these properties are altered by varying the spin acceleration time (tacc) was undertaken. The results showed that, by varying tacc, there is no significant variation in crystal size, and band gap energy of the films, while some physical parameters such as strain ε, surface roughness (RMS), and porosity (P) are remarkably varied. By increasing tacc from 0 to 8 s, ε, RMS, and P, were increased by 230, 83, and 49%, respectively. Electrical data were presented to demonstrate unambiguously that the variation in the films resistivity (ρ) is closely connected to the change in these parameters. To explain these findings, a simple formula was proposed in the investigated range of tacc, which demonstrated that ρ is more related to ε and P, and then to RMS. [ABSTRACT FROM AUTHOR]

This study concerns the first urinary schistosomiasis case observed in Corsica (France, Europe) occurring in a 12-year-old German boy. The aim was to identify the relationship between this Schistosoma haematobium infection and other schistosomes of the Schistosoma group with terminal-spined ova. Morphological and molecular analyses were conducted on the ova. The results showed that the schistosome responsible for the emergence of schistosomiasis in Corsica was due to S. haematobium introgressed by genes from S. bovis. [ABSTRACT FROM AUTHOR]

Calcium titanate (CaTiO) nanoparticles with different average sizes were prepared by a polyacrylamide gel route, where the particle size was tailored by using different chelating agents. Scanning electron microscope observation shows that the samples prepared by using the chelating agents EDTA, acetic acid, tartaric acid, and citric acid have an average particle size of 25, 33, 36, and 55 nm, respectively. All the particles are regularly shaped like spheres. The bandgap energy of the four samples is measured to be 3.66-3.59 eV by ultraviolet (UV)-visible diffuse reflectance spectroscopy. The photocatalytic activity of the prepared CaTiO samples was evaluated by the degradation of methyl orange under 254 nm UV irradiation, revealing that they exhibit a good photocatalytic activity. Hydroxyl radicals are revealed, by the photoluminescence technique using terephthalic acid as a probe molecule, to be produced on the irradiated CaTiO nanoparticles and suggested to be the primary active species toward the dye degradation. [ABSTRACT FROM AUTHOR]

Several medicinally important compounds carry benzimidazole carbamate moiety. In the scientific literature, these molecules are represented in different tautomeric forms. In this report, conformational and tautomeric preferences were analyzed on the model benzimidazole carbamate (carbendazim), so as to understand the potential energy surface of the title compounds. Quantum chemical calculations have been performed using HF, B3LYP, and MP2 methods in gas phase and solvent phase on model benzimidazole carbamate to understand the conformational and tautomeric preferences. (1) PE surface of amide-imide tautomers, (2) electron distribution, (3) AIM analysis, (4) NBO charges, (5) 1,3-H shift, etc., have been investigated for carbendazim and its conformers. The molecular electrostatic potential (MESP) surfaces of carbendazim have been studied. Further to understand the polymorphism in benzimidazole carbamate, analysis of dimers of carbendazim has been carried out. The results indicate that a neglected tautomer is important and the tautomeric equilibrium is quite subtle in these systems and it should be extensively considered in all studies related to these drugs. [ABSTRACT FROM AUTHOR]