Dental caries results from the bacterial pathogen Streptococcus mutans (S. mutans) and is the maximum critical reason for caries formation. Consequently, the present study aims to evaluate the antibacterial activity of a newly synthesized nanoantibiotic–Biodentine formulation. The silver nanoparticles (ROE-AgNPs) were biosynthesized from the usage of Rosmarinus officinalis L. extract (ROE) and conjugated with cefuroxime to form Cefuroxime-ROE-AgNPs. Using Biodentine™ (BIOD), five groups of dental materials were prepared, in which Group A included conventional BIOD, Group B included BIOD with ROE-AgNPs, Groups C and D included BIOD with Cefuroxime-ROE-AgNPs at concentrations of 0.5% and 1.5% cefuroxime, respectively, and Group E included BIOD with 1.5% cefuroxime. The synthesized ROE-AgNPs or Cefuroxime-ROE-AgNPs were characterized for conjugating efficiency, morphology, particle size, and in vitro release. Minimum inhibitory concentration (MIC) of the cefuroxime, ROE-AgNPs, and Cefuroxime-ROE-AgNPs were additionally evaluated against cefuroxime resistant S. mutans, which furthered antibacterial efficacy of the five groups of dental materials. The UV-Visible spectrum showed the ROE-AgNPs or Cefuroxime-ROE-AgNPs peaks and their formation displayed through transmission electron microscopy (TEM), X-ray diffraction (XRD) pattern, and Fourier transforms infrared (FTIR) analysis. The end result of Cefuroxime-ROE-AgNPs showed conjugating efficiency up to 79%. Cefuroxime-ROE-AgNPs displayed the highest antibacterial efficacy against S. mutans as compared to cefuroxime or ROE-AgNPs alone. Moreover, the MIC of ROE-AgNPs and Cefuroxime-ROE-AgNPs was detected against S. mutans to be 25 and 8.5 μg/mL, respectively. Consequently, Cefuroxime-ROE-AgNPs displayed that a decrease in the MIC reached to more than three-fold less than MIC of ROE-AgNPs on the tested strain. Moreover, Cefuroxime-ROE-AgNPs/BIOD was employed as a novel dental material that showed maximum antimicrobial activity. Groups C and D of novel materials showed inhibitory zones of 19 and 26 mm, respectively, against S. mutans and showed high antimicrobial rates of 85.78% and 91.17%, respectively. These data reinforce the utility of conjugating cefuroxime with ROE-AgNPs to retrieve its efficiency against resistant S. mutant. Moreover, the nanoantibiotic delivered an advantageous antibacterial effect to BIOD, and this may open the door for future conjugation therapy of dental materials against bacteria that cause dental caries. 

Dental pathogens lead to chronic diseases like periodontitis that causes loss of teeth. This research was to examine the plausible antibacterial efficacy of copper nanoparticles (CME-CuNPs) synthesized using Cupressus macrocarpa extract (CME) against periodontitis-causing bacteria. Moreover, antimicrobial properties of CME-CuNPs were assessed against oral microbes (M. luteus. B. subtilis, P. aerioginosa), which causes periodontal disease which was identified using morphological, biochemical analysis, and 16S-rRNA techniques. The CME-CuNPs were characterized by analysis techniques. Accordingly, the peak found at 577 nm using UV-vis spectrometer explained the formation of stable CME-CuNPs. Also, the results revealed the formation of spherical and oblong monodispersed CME-CuNPs with sizes ranged from 11.3 to 22.4 nm. The FTIR analysis suggested that the CME contains reducing agents. Consequently, they had a role in Cu reduction, and CME-CuNPs were formed. Furthermore, the CME-CuNPs exhibited potent antimicrobial efficacy against different isolates and it was superior to the reported values in literature. Antibacterial efficacy of CME-CuNPs upon testing bacteriawas compared to the synergistic solutionof clindamycin with CME-CuNPs. Particularly, synergistic solutions exhibited a superior capacity to prevent the selected bacterialgrowth. Minimum inhibitory concentration (MIC), Minimum bactericidal concentration (MBC), and FIC (Fractional Inhibitory Concentration) of CME-CuNPs with clindamycin recorded against the selected periodontal disease-causing microorganisms are observed between the range of 2.6-3.6 …

Electron/hole traps alter the optical and electrical properties of materials by creating additional recombination pathways, trapping or providing charge carriers and modifying exciton dynamics. Understanding the defect/trap dynamics is crucial to control the optoelectronic properties of materials, and measuring donor/acceptor ionization energy is critical in semiconductor research. Here, we developed a highly sensitive thermally stimulated emission (TSE) spectrometer for the low temperature regime of 9–325 K to detect and characterize shallow traps in bandgap materials with enhanced sensitivity. It provides a powerful characterization tool for a wide range of semiconductors and electronic and photonic materials. This technique is ideal where electrical methods cannot be used for donor/acceptor characterization as in powder, irregular shape and thickness, and high resistive samples. 

Electron/hole traps alter the optical and electrical properties of materials by creating additional recombination pathways, trapping or providing charge carriers and modifying exciton dynamics. Understanding the defect/trap dynamics is crucial to control the optoelectronic properties of materials, and measuring donor/acceptor ionization energy is critical in semiconductor research. Here, we developed a highly sensitive thermally stimulated emission (TSE) spectrometer for the low temperature regime of 9–325 K to detect and characterize shallow traps in bandgap materials with enhanced sensitivity. It provides a powerful characterization tool for a wide range of semiconductors and electronic and photonic materials. This technique is ideal where electrical methods cannot be used for donor/acceptor characterization as in powder, irregular shape and thickness, and high resistive samples. 

Photoemission is used for a large variety of experimental techniques for study of material properties. Further applications photoemission finds for electron beam generation. Development of photocathodes with high quantum efficiency requires sufficient microscopic understanding of photoemission processes. The LaB₆ is a well-known thermionic emitter, which can be used as a photocathode. Anomalous, thermally assisted increase of quantum efficiency was previously demonstrated for this material. The increase shows a bi-exponential rise with photon-energy dependent slopes. The photon-energy dependency indicates correlation of extracted current with electronic band structure. In this work, we have investigated possible mechanisms, which could be the reason for the anomalous dependence of photoemission current on the cathode temperature. In particular, the Fowler–DuBridge theory was modified to account for changes in the electron density of states. The results show negligible low influence of density of states structure. Finally, we make a suggestion regarding the modification of the electron escape probability, which can cause the increase in photoemission.

Enhanced hydrogen evolution was pursued in this work. Rhodobacter sp. (Rb) and Rhodopseudomonas palustris (Rp), single or mixed were used to extract hydrogen molecules from Chlorella fusca biomass. To elevate their fermentable contents, Chlorella was grown at nitrogen and/or phosphorus deprivation. Besides, cellulase and/or macerozyme, Triton X100 or sonicated yeast were applied for further biohydrogen fermentation. Utilizing hydrolysates of mineral deprived Chlorella cultures, Rb exhibited relatively higher cumulative hydrogen (4200 ml L1 ) than Rp (2500 ml L1 ) while mixed cultures attained significantly higher levels (4700 ml L1 ). Triton or enzymes significantly enhanced hydrogen evolution, with more effectiveness of macerozyme than cellulase. A novel use of sonicated yeast, as enzymes pool, induced the highest significant collective H2 (up to 47 times that of microalgal supernatant). Sonicated yeast induced a remarkable hydrolysis of algae, as inferred from increased reducing sugars. However, hydrogen evolution efficiency exhibited poor proportionality with reducing sugars, indicating fermentation of other metabolites. © 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Enhanced hydrogen evolution was pursued in this work. Rhodobacter sp. (Rb) and Rhodopseudomonas palustris (Rp), single or mixed were used to extract hydrogen molecules from Chlorella fusca biomass. To elevate their fermentable contents, Chlorella was grown at nitrogen and/or phosphorus deprivation. Besides, cellulase and/or macerozyme, Triton X100 or sonicated yeast were applied for further biohydrogen fermentation. Utilizing hydrolysates of mineral deprived Chlorella cultures, Rb exhibited relatively higher cumulative hydrogen (4200 ml L1 ) than Rp (2500 ml L1 ) while mixed cultures attained significantly higher levels (4700 ml L1 ). Triton or enzymes significantly enhanced hydrogen evolution, with more effectiveness of macerozyme than cellulase. A novel use of sonicated yeast, as enzymes pool, induced the highest significant collective H2 (up to 47 times that of microalgal supernatant). Sonicated yeast induced a remarkable hydrolysis of algae, as inferred from increased reducing sugars. However, hydrogen evolution efficiency exhibited poor proportionality with reducing sugars, indicating fermentation of other metabolites. © 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

The p38 mitogen-activated protein kinases (p38 MAPK) is a 38kD polypeptide recognized as the target for many potential anti-inflammatory agents. Accumulating evidence indicates that p38 MAPK could perform many roles in human disease pathophysiology. Therefore, great therapeutic benefits can be attained from p38 MAPK inhibitors. Ginseng is an exceptionally valued medicinal plant of the family Araliaceae (Panax genus). Recently, several studies targeted the therapeutic effects of purified individual ginsenoside, the most significant active ingredient of ginseng, and studied its particular molecular mechanism(s) of action rather than whole-plant extracts. Interestingly, several ginsenosides: ginsenosides compound K, F1, Rb1, Rb3, Rc, Rd, Re, Rf, Rg1, Rg2, Rg3, Rg5, Rh1, Rh2, Ro, notoginsenoside R1, and protopanaxadiol have shown to possess great therapeutic potentials mediated by their ability to downregulate p38 MAPK signaling in different cell lines and experimental animal models. Our review compiles the research findings of various ginsenosides as potent anti-inflammatory agents, highlighting the crucial role of p38 MAPK suppression in their pharmacological actions. In addition, in silico studies were conducted to explore the probable binding of these ginsenosides to p38 MAPK. The results obtained proposed p38 MAPK involvement in the beneficial pharmacological activities of ginsenosides in different ailments.

Zn-rich ZnCdS nanoparticles (NPs) are successfully synthesized by a facile chemical co-precipitation technique at room temperature. The crystal structure homogeneity of the as-synthesized ternary alloy is examined by the x-ray diffraction pattern and the micro-Raman spectroscopy. The average crystalline domain size is about 4 nm
indicating the spatial particle confinement of ternary ZnCdS NPs. The optical bandgap (Eg) of the as-synthesized
ZnCdS NPs is 3.95 eV that is higher than the corresponding ternary bulk alloy due to the improvement in the
quantum size effect. The effect of UV irradiation on the optical band gap of ZnCdS NPs is investigated at different
exposure times. A strong decrease in Eg is observed with increasing exposure time up to 60 min followed by Eg
saturation at higher UV exposure times. The as-synthesized ZnCdS nanopowder exhibits a wide emission spectrum extending from UV to visible spectral region, which originating from various intrinsic structural defects.
The aging of the as-synthesized ZnCdS nanopowder results in emission intensity quenching without changing
peak positions. The emission intensity is recovered by the direct exposure to UV irradiation. This indicates the
ability of UV irradiation to cure the emission characteristics of small NPs. This would provide more durability
about the emission characteristics of the ZnCdS NPs-based fluorescence sensor.

The exfoliation of micron-layered materials to few-layered nanosheets is still a great challenge due to their widespread use in various applications. Herein, we provide a new approach for one-step mechanical exfoliation and deposition of graphite, MoS2, and boron nitride at room temperature. The essence of this technique is that the shock compaction wave produced by the micron powder impact with the hard substrate at a high velocity induces fragmentation and exfoliation of layered materials. The lattice expansion due to removal of stacked layers and reduction of crystalline domain size in nanosized thin films is identified using x-ray diffraction and a high-resolution transmission electron microscope. Raman spectra of the nanostructured thin film indicate the improvement of disorder-related modes due to the kinetic-induced layer separation and powder fragmentation. X-ray photoelectron spectra analysis indicates the transformation of bond configuration from sp² hybridization of bulk hexagonal structure to sp³ in the nanostructured thin film.