Scanning Electron Microscopy Studies Research Articles

Spirolactam ring locking and unlocking tuned solvent regulated unique Hg(II) sensing by a novel AIE active Rhodamine −1, 2 diamino propane-based Schiff chemosensor and its pH sensor performance

The present study highlights the development, identification, and solvent-regulated chemosensing property of a Schiff base chemosensor (E)-2-(2-((5-chloro-2-hydroxybenzylidene)amino)propyl)-3′,6′-bis(diethylamino)spiro[isoindoline-1,9′-xanthen]-3-one (RBAS). The Schiff base RBAS is developed by the simple condensation of 5-chloro salicylaldehyde and rhodamine-1,2 diamino propane derivative (RBAP). Interestingly this probe can optically as well as fluorometrically exhibit pH sensor activity and the spirolactam ring opening and the conversion from enol to keto form in lower and higher pH regions respectively are the main key factors to show pH sensor activity. Several spectroscopic, Dynamic Light Scattering (DLS), and scanning electron microscopy (SEM) studies confirm the AIE active property of the probe in 2:8 DMSO-water and ethanol-water mediums where the probe exhibits strong luminescence properties. Interestingly in ethanol-water and DMSO-water medium, it can detect Hg(II) via turn-on and off fluorescence respectively. Actually, in different solvent mediums, the presence of Hg(II) plays a crucial role in the spirolactam ring opening and closing of the developed probe. Simultaneously in an ethanol-water medium, it can detect picric acid by turning off fluorescence. By using mass and NMR spectrum analysis, the 1:1 stoichiometric addition of the probe and target analytes has been verified and the density functional theory (DFT) study is implemented in optimizing the probe-analyte structure. The live cell imaging study gives the approval of the biosensing ability of the probe. Impressively the probe can be successfully used to detect Hg(II) in real soil samples.

Preparation and investigation of Montmorillonite-K10 Polyaniline nanocomposites for optoelectronic applications

One-dimensional polyaniline (PANI) nanostructures were synthesized in situ in the presence of two-dimensional (2D) Montmorillonite (MMT) clay nanosheets. Strong interactions between the polymer and MMT platelets in the nanocomposites were confirmed through spectroscopic studies. X-ray diffraction and scanning electron microscopic studies revealed the clay's profound effect on the polymer's crystallinity and morphology. The clay nanosheets induced higher crystallinity and well-defined nanorod morphology in the polymer structure. Consequently, the nanocomposite showed an electrical conductivity of 8.72 S/cm, closer to that of the pristine polymer (8.97 S/cm), despite the presence of highly insulting clay material. Surprisingly, a notable decrease in the optical bandgap of the polymer from 3.73 to 2.88 eV of the nanocomposite was also observed. This novel integration of a narrow band gap and high conductivity in PANI/MMT nanocomposites can expand their utility for visible light interactions in areas encompassing photocatalysis, photovoltaics, electro/photochromism, and related technologies.

Cu/Co binary‐transition metal glycerolates as anode materials for lithium‐ion batteries

AbstractThe energy density of Lithium‐ion batteries (LiBs) fails to keep pace with the growing demand for long‐driving range EVs. Developing novel anode materials with high specific capacities is one of the most effective ways to increase the energy density of LiBs. Herein, a series of Cu and Co binary‐transition metal glycerolates (labeled as CuxCoy/G) were prepared as the anodes for LiBs. It was observed that CuxCoy/G exhibited a distinctive yolk‐shell architecture, which significantly differed from the solid spherical structure of Cu/G and Co/G counterparts. X‐ray powder diffraction and Scanning electron microscope studies suggested that Cu element existed as Cu2+1O in CuxCoy/G, and the Co element was in the form of amorphous glycerolates. Electrochemical studies showed that Cu0.4Co1/G delivered a high capacity over 1000 mAh g−1 at the first discharge, and it exhibited the most stable cycling performance over 200 cycles. Mechanism study suggested both Cu and Co elements contributed to lithium storage capacities in CuxCoy/G at the initial discharging process. Experimental results revealed that Co exhibited reversible capacity while Cu element was reduced to metallic Cu which contributed to the electronic conductivity, rendering Cu0.4Co1/G exhibited a better long‐term cycling stability than Co/G. This work explored a new type of anode material with high specific capacity for LiBs, paving the way to high energy density LiBs.

Comparative evaluation of smear layer removal by using different irrigant activation techniques: An in vitro scanning electron microscopic study.

This in vitro study aims to assess and compare the effectiveness of different irrigation activation techniques in removing the smear layer from the root canal dentin using Scanning electron microscope (SEM) analysis. A total of 60 extracted single-rooted premolar with straight canal and mature apex were used for this study. After the selection of teeth, all the samples were decoronated followed by biomechanical preparation. The sample after preparation was irrigated with sodium hypochlorite and randomly divided into three groups with 20 sample in each group (n = 20), (Group 1) control, (Group 2) ultrasonic, and (Group 3) laser. The irrigant activation was done in all the groups and then sample was prepared for the scanning electron microscope analysis. The statistical analysis was performed using the Mann-Whitney-U-test. The findings suggested that the diode laser irrigant activation technique was superior to the ultrasonic and conventional techniques to eradicate smear layers. With the limitation of this study, diode laser activation showed better cleaning of root dentinal walls compared to ultrasonic activator and traditional method.

Comparative evaluation of remineralization efficacy of ELSENZ and SHY-XT toothpastes on initial enamel lesions: A scanning electron microscopic study

The present study was done to evaluate the remineralization potential of two different commercially available toothpaste, namely, ELSENZ and SHY-XT on initial enamel white spot lesion using Scanning Electron Microscope (SEM). The objective of this study is to evaluate and compare the remineralization efficacy of ELSENZ and SHY-XT toothpaste on initial enamel white spot lesion. This study included a total 12 samples of extracted human permanent anterior teeth that were collected from the Oral and Maxillofacial Department in College of Dental Science Amargadh, Bhavnagar, Gujarat. All samples were equally divided in three groups. In group 1, remineralization was done by ELSENZ (fluoro-calcium phosphosilicate) toothpaste, and in group 2, remineralization was done by SHY-XT (nano–hydroxyapatite and fluoride) toothpaste and group 3 was taken as control group in which deionized water was used. At the end of 12 days, pH cycling procedure, remineralization for all the samples were analysed by the scanning electron microscope. Statistical analysis was done by One Way Analysis of Variance to check the difference between the groups and Post hoc analysis was done by Tukey’s test. The result showed that the maximum remineralization occurred in ELSENZ toothpaste group (P<0.00) followed by SHY-XT toothpaste group (P<0.50) and deionized water showed least remineralization potential (P<2.00). From the result of the study, we concluded that ELSENZ toothpaste has more remineralization potential on initial enamel white spot lesion as compared to SHY-XT toothpaste.

Visible‐Light‐Active Electrospun Membranes Based on Cobalt‐Doped ZnO Nanohybrids: Applications for Food Packaging

AbstractA cellulose acetate electrospun membrane based on Cobalt doped ZnO (Co‐ZnO) was developed. The synthesis of pure zinc oxide nanoparticles (NPs) and cobalt‐zinc oxide nanorods with varying cobalt‐to‐zinc atomic ratios of 5 %, 10 %, 15 %, and 20 % was carried out, using the co‐precipitation method. The successful incorporation of cobalt into ZnO was confirmed by using the techniques of Powder X‐ray Diffraction (PXRD), X‐ray Photoelectron Spectroscopy (XPS), and Energy Dispersive X‐ray Spectroscopy (EDX). Scanning Electron Microscopy (SEM) studies denoted the change in shape from spherical to rod‐shaped upon doping Co. A red shift was observed in band gap energies from 3.26‐3.01 eV upon increasing the Co concentration. The photocatalytic activity was evaluated, using methylene blue under sunlight and a 50 W LED lamp. The most effective photocatalyst observed in this study was a composition consisting of 15 % Co‐ZnO. When exposed to sunshine, this photocatalyst demonstrated a degradation rate of 40 % over a one‐hour period. Similarly, when subjected to a lamp, the degradation rate was found to be 24 % over the same duration. A nanofiber membrane was produced by incorporating Co‐ZnO at a concentration of 15 % (w/w) into the cellulose acetate (CA) polymer matrix by the electrospinning technique. The created CA nanofiber mat with Co‐ZnO was employed to extend the shelf life of strawberries up to 18 days along with the reduced pH increase and lower reduction of weight, firmness, and titratable acidity.

Development of highly sensitive electrochemical immunosensor using PPy-MoS2-based nanocomposites modified with 90MeV C6+ ion beams.

Theevaluation of electrochemical sensing activity of hydrothermally derived PPy-MoS2-based nanocomposites subjected to 90MeV C6+ ion beam with fluence ranging, 1.0 × 1010-1.0 × 1013 ions/cm2, is reported. Cross-linking, chain scissioning, and ion track formation could occur in the irradiated systems, as revealed from Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FE-SEM)studies. Electrochemical studies, viz., cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed in 0.1M phosphate buffer solution (PBS) containing 5mM K3[Fe(CN)6] as redox probe. High redox activity, lower charge transfer resistance (Rct = 490 Ω) and larger electroactive area (A = 0.4485 cm2) were obtained in case of the composite system irradiated with a fluence of 3.5 × 1011 ions/cm2. Immunosensor fabrication was executed via immobilization of mouse IgG over the pristine and post-irradiated electrodes. Afterwards, differential pulse voltammetry (DPV) was performed within thepotential window - 0.2 to + 0.6V (vs. Ag/AgCl) for the detection of specific analyte. Noticeably, the electrode system irradiated with a fluence of 3.5 × 1011 ions/cm2 ischaracterized by a lower limit of detection (LOD) of 0.203nM and a higher sensitivity value of 10.0 µAmLng-1cm-2. The energetic particle irradiation at a modest fluence can offer beneficial effects to thePPy-MoS2-based nanohybrid system providing immense scope as advanced electrochemical biosensor.

Taxonomic significance of megaspores in some species of Selaginella from Arunachal Pradesh in India.

The present study was carried out to record the color, size, and ornamentation of megaspores in 18 species of the family Selaginellaceae from Arunachal Pradesh using scanning electron microscope (SEM) and light microscope (LM). Electron microscopic study of the spore features revealed the type of ornamentation and microsculptural detail. SEM study on megaspore of Selaginella pentagona (S. pentagona), Selaginella tenuifolia, Selaginella semicordata, and Selaginella chrysorrhizos is presented for the first time. Variation in the megaspore ornamentation is noted at the interspecific level and intraspecific level in some cases. Examination of the megaspores under study found all the megaspores as trilete, with a size ranging from 116 to 560 μm in diameter. Taxonomic key is prepared to differentiate the species. Short descriptions of megaspores are provided and supported by photo plates. New features are recorded for seven species. The study contributes to the separation of species within the genus Selaginella based on the spore feature and brings forward the use of spore as a diagnostic tool in the taxonomy of the genus. These works contribute to the systematic of the family Selaginellaceae and provide useful information in the field of palynology. RESEARCH HIGHLIGHTS: Study on megaspore features of Selaginella species collected from Arunachal Pradesh, using SEM and LM. Taxonomic key is provided for each species based on megaspores features. New megaspore features are recorded for the seven species. The study brings forward the use of spore as a diagnostic tool in the taxonomy of the genus. These works provide useful information in the field of systematic and palynology.

In vitro efficacy of Er:YAG laser-activated irrigation versus passive ultrasonic irrigation and sonic-powered irrigation for treating multispecies biofilms in artificial grooves and dentinal tubules: an SEM and CLSM study

BackgroundMultispecies biofilms located in the anatomical intricacies of the root canal system remain the greatest challenge in root canal disinfection. The efficacy of Er:YAG laser-activated irrigation techniques for treating multispecies biofilms in these hard-to-reach areas has not been proved. The objective of this laboratory study was to evaluate the effectiveness of two Er:YAG laser-activated irrigation techniques, namely, photon-induced photoacoustic streaming (PIPS) and shock wave-enhanced emission photoacoustic streaming (SWEEPS), in treating multispecies biofilms within apical artificial grooves and dentinal tubules, in comparison with conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI), and sonic-powered irrigation (EDDY). Two types of multispecies root canal biofilm models were established in combination with two assessment methods using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) with the aim to obtain more meaningful results.MethodsNinety extracted human single-rooted premolars were chosen for two multispecies biofilm models. Each tooth was longitudinally split into two halves. In the first model, a deep narrow groove was created in the apical segment of the canal wall. After cultivating a mixed bacterial biofilm for 4 weeks, the split halves were reassembled and subjected to five irrigation techniques: CNI, PUI, EDD, PIPS, and SWEEPS. The residual biofilms inside and outside the groove in Model 1 were analyzed using SEM. For Model 2, the specimens were split longitudinally once more to evaluate the percentage of killed bacteria in the dentinal tubules across different canal sections (apical, middle, and coronal thirds) using CLSM. One-way analysis of variance and post hoc multiple comparisons were used to assess the antibiofilm efficacy of the 5 irrigation techniques.ResultsRobust biofilm growth was observed in all negative controls after 4 weeks. In Model 1, within each group, significantly fewer bacteria remained outside the groove than inside the groove (P < 0.05). SWEEPS, PIPS and EDDY had significantly greater biofilm removal efficacy than CNI and PUI, both from the outside and inside the groove (P < 0.05). Although SWEEPS was more effective than both PIPS and EDDY at removing biofilms inside the groove (P < 0.05), there were no significant differences among these methods outside the groove (P > 0.05). In Model 2, SWEEPS and EDDY exhibited superior bacterial killing efficacy within the dentinal tubules, followed by PIPS, PUI, and CNI (P < 0.05).ConclusionEr:YAG laser-activated irrigation techniques, along with EDDY, demonstrated significant antibiofilm efficacy in apical artificial grooves and dentinal tubules, areas that are typically challenging to access.

Biosurfactant-Assisted Cu Doping of Brushite Coatings: Enhancing Structural, Electrochemical, and Biofunctional Properties.

Stainless steel (316L SS) has been widely used in orthopedic, cardiovascular stents, and other biomedical implant applications due to its strength, corrosion resistance, and biocompatibility. To address the weak interaction between steel implants and tissues, it is a widely adopted strategy to enhance implant performance through the application of bioactive coatings. In this study, Cu-doped brushite coatings were deposited successfully through pulse electrodeposition on steel substrates facilitated with a biosurfactant (BS) (i.e., surfactin). Further, the combined effect of various concentrations of Cu ions and BS on the structural, electrochemical, and biological properties was studied. The X-ray diffraction (XRD) confirms brushite composition with Cu substitution causing lattice contraction and a reduced crystallite size. The scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) studies reveal the morphological changes of the coatings with the incorporation of Cu, which is confirmed by X-ray photoelectron spectroscopy (XPS) and elemental mapping. The Fourier transform infrared (FTIR) and Raman spectroscopy confirm the brushite and Cu doping in the coatings, respectively. Increased surface roughness and mechanical properties of Cu-doped coatings were analyzed by using atomic force microscopic (AFM) and nanohardness tests, respectively. Electrochemical assessments demonstrate corrosion resistance enhancement in Cu-doped coatings, which is further improved with the addition of biosurfactants. In vitro biomineralization studies show the Cu-doped coating's potential for osseointegration, with added stability. The cytocompatibility of the coatings was analyzed using live/dead and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays; cell adhesion, proliferation, and migration studies were evaluated using SEM. Antibacterial assays highlight significant improvement in the antibacterial properties of Cu-doped coatings with BS. Thus, the developed Cu-doped brushite coatings with BS demonstrate their potential in the realm of biomedical implant technologies, paving the way for further exploration.

Nanostructured Coatings Based on Graphene Oxide for the Management of Periprosthetic Infections.

To modulate the bioactivity and boost the therapeutic outcome of implantable metallic devices, biodegradable coatings based on polylactide (PLA) and graphene oxide nanosheets (nGOs) loaded with Zinforo™ (Zin) have been proposed in this study as innovative alternatives for the local management of biofilm-associated periprosthetic infections. Using a modified Hummers protocol, high-purity and ultra-thin nGOs have been obtained, as evidenced by X-ray diffraction (XRD) and transmission electron microscopy (TEM) investigations. The matrix-assisted pulsed laser evaporation (MAPLE) technique has been successfully employed to obtain the PLA-nGO-Zin coatings. The stoichiometric and uniform transfer was revealed by infrared microscopy (IRM) and scanning electron microscopy (SEM) studies. In vitro evaluation, performed on fresh blood samples, has shown the excellent hemocompatibility of PLA-nGO-Zin-coated samples (with a hemolytic index of 1.15%), together with their anti-inflammatory ability. Moreover, the PLA-nGO-Zin coatings significantly inhibited the development of mature bacterial biofilms, inducing important anti-biofilm efficiency in the as-coated samples. The herein-reported results evidence the promising potential of PLA-nGO-Zin coatings to be used for the biocompatible and antimicrobial surface modification of metallic implants.

Bisphosphonate's effect on the tongue in adult male albino rats and the possible protective role of rutin: light and scanning electron microscopic study.

Alendronate sodium (ALS) is a nitrogen-containing bisphosphonate used for the treatment of different bone disorders. However, its adverse effect on oral soft tissue has been detected. Rutin (RUT) is natural flavonoid with antioxidant and anti-inflammatory properties. This work aimed to investigate the possible effect of ALS on the tongue of adult male albino rats and to evaluate the possible protective role of RUT. Forty adult male albino rats were equally divided into four groups: group I (control), group II (RUT): Received RUT 50 mg/kg, group III (ALS): Received ALS 1 mg/kg, group IV (ALS+RUT): Received ALS and RUT with the same doses as pervious groups. The drugs were given once daily for 5 weeks. Tongue specimens were taken and processed for light and scanning electron microscopic inspection. ALS treated group revealed structural changes in the tongue in the form of decrease in the height of the filiform papillae with blunt ends, marked atrophy in some papillae with areas of focal loss, loss of some epithelial cells, pyknotic nuclei and cytoplasmic vacuoles in some epithelial cells. The lamina propria showed inflammatory cellular infiltration with congested blood vessels. Statistically, there were highly significant decrease in the number of proliferating cell nuclear antigen immunopositive cells, area percentage of Bcl-2 immunoexpression and highly significant increase in the collagen content compared to control group. Administration of RUT with ALS minimizes these changes. RUT protected the rat tongue against the histological and immunohistochemical changes induced by ALS through its antioxidant and anti-inflammatory properties.

ADARs regulate cuticle collagen expression and promote survival to pathogen infection

BackgroundIn all organisms, the innate immune system defends against pathogens through basal expression of molecules that provide critical barriers to invasion and inducible expression of effectors that combat infection. The adenosine deaminase that act on RNA (ADAR) family of RNA-binding proteins has been reported to influence innate immunity in metazoans. However, studies on the susceptibility of ADAR mutant animals to infection are largely lacking.ResultsHere, by analyzing adr-1 and adr-2 null mutants in well-established slow-killing assays, we find that both Caenorhabditis elegans ADARs are important for organismal survival to gram-negative and gram-positive bacteria, all of which are pathogenic to humans. Furthermore, our high-throughput sequencing and genetic analysis reveal that ADR-1 and ADR-2 function in the same pathway to regulate collagen expression. Consistent with this finding, our scanning electron microscopy studies indicate adr-1;adr-2 mutant animals also have altered cuticle morphology prior to pathogen exposure.ConclusionsOur data uncover a critical role of the C. elegans ADAR family of RNA-binding proteins in promoting cuticular collagen expression, which represents a new post-transcriptional regulatory node that influences the extracellular matrix. In addition, we provide the first evidence that ADAR mutant animals have altered susceptibility to infection with several opportunistic human pathogens, suggesting a broader role of ADARs in altering physical barriers to infection to influence innate immunity.

The Influence of Nickel-Titanium (Ni-Ti) Rotary Instrument Systems on Debris and Smear Layer Formation in Endodontic Procedures: An In Vitro Scanning Electron Microscopy Study.

Background Successful endodontic treatment relies on the effective removal of debris and the prevention of smear layer formation within the root canals. The choice of nickel-titanium (Ni-Ti) rotary instrument systems can significantly impact these outcomes. Aim This study aims to evaluate and compare the debris and smear layer formation in root canals of extracted mandibular second premolar teeth following instrumentation with the ProTaper Universal (Dentsply Sirona,Charlotte, NC) (Group II), Twisted File (Kerr Endodontics, Gilbert, AZ) (Group III), and XP Endo (FKG Dentaire,La Chaux-de-Fonds, Switzerland) (Group IV) Ni-Ti rotary instrument systems. Methods In this in vitro study, 60 extracted mandibular second premolar teeth were randomly divided into four groups, each containing 15 teeth. Group I served as the control with no instrumentation. Groups II, III, and IV were instrumented with the ProTaper Universal rotary file, the Twisted File, and the XP Endo file systems, respectively. Debris and smear layer formation were evaluated through scanning electron microscopy (SEM), and photomicrographs were scored using a standardized index. Results Group II (ProTaper) exhibited the highest mean debris and smear layer scores, with values of 3.50 and 2.70, respectively. Group IV (XP Endo) demonstrated the least debris and smear layer formation, with mean scores of 2.65 and 2.08, respectively. Statistical analysis confirmed significant differences among the groups for both debris and smear layer formation. Conclusion The results highlight the practical importance of selecting appropriate Ni-Ti rotary instrument systems to minimize debris and smear layer formation during endodontic procedures. The XP Endo file system showed promise as a favorable choice in this regard, but further clinical research is needed to validate these findings.

Synthesis of V-shaped Thiophene Based Rotor-Stilbene: Substituent Dependent Aggregation and Photophysical Properties.

Thiophene core V-shaped rotor-stilbene derivatives have been synthesized utilizing two-fold Heck coupling reaction. These compounds are blue emitters with moderate quantum yield in dilute solution. Rotor nature of the synthesized stilbenes supports aggregation induced emission (AIE) behaviour and they show substituent dependent emission behavior in aggregate state. In presence of donating groups (e.g., tert-butyl, methoxy, diphenylamine group) in stilbenes, they exhibit AIE property. But with the introduction of electron withdrawing group (nitro group), they shows aggregation caused quenching (ACQ) behavior. Different types of nano-aggregates formation is observed in aggregated state, which was confirmed by dynamic light scattering (DLS) and scanning electron microscopy (SEM) studies. The details photophysical (absorption, fluorescence, and lifetime), electrochemical property (cyclic voltammetry) and thermal stability have been investigated. Optimized structure, energy and electronic distribution of molecular orbitals have been studied by theoretical calculation.

Emission enhancement in the luminescence performance of warm red light-emitting LiSrVO4 :Pr3+ phosphors.

Warm red-emitting praseodymium-doped LiSrVO4 phosphors were synthesized via solid-state reaction. The phase formation was verified using an X-ray diffraction study and the morphology was investigated using a scanning electron microscope study. The LiSrVO4 :Pr3+ phosphors emitted red light when exposed to ultraviolet light, indicating their possibility for use in warm white light-emitting diodes (WLEDs). Furthermore, the effect of charge compensators on the luminescence characteristics was addressed. The decay time was investigated using time-resolved photoluminescence. Furthermore, thermal quenching was analyzed through temperature-dependent photoluminescence spectra. Their sensitivity was calculated using temperature-dependent decay time analysis. The colour purity of the emitted light could be measured by photometric analysis. This comprehensive investigation provides a thorough understanding of the luminescence properties of phosphors for WLED applications.

Exploring microscopic pollen morphology in herbaceous Flora: Insights and analysis using scanning electron microscopy.

Microscopic techniques can be applied to solve taxonomic problems in the field of plant systematic and are extremely versatile in nature. This study was focused on the new approaches to visualizing the imaging, tool to cover the micro-structural techniques applied to the pollen study of flowers. The current research was proposed to evaluate microscopic pollen morphological attributes using light and scanning electron microscopy of herbaceous flora from Samarkand, Uzbekistan. A total of 13 herbaceous species, classified into 11 different families were collected, pressed, and identified, and then acetolyzed their pollen to visualize under light and scanning electron microscopy. Herbaceous flora can be characterized by small to very large-sized pollen morphotypes presenting four types of pollen shapes, prolate spheroidal (six species), spheroidal (three species) and prolate and oblate (two species each). The polar diameter and equatorial distance were calculated maximum in Hibiscus syriacus 110.55 and 111.2 μm respectively. Pollen of six different types was found namely tricolporate pollen observed in seven species, tricolpate and pantoporate in two species each, sulcate in Gagea olgae and hexacolpate pollen was examined in Salvia rosmarinus. Exine ornamentation of pollen was examined tectate perforate, verrucate-reticulate, micro-reticulate, reticulate, reticulate-cristatum, gemmate-echinate, echinate-perforate, perforate-striate, rugulate, rugulate-striate, bi-reticulate, reticulate-perforate and perforate-micro-reticulate showing great variations. Exine thickness was noted highest for Rosa canina 2.9 μm and minimum in Punica granatum 0.65 μm. This study of pollen imaging visualization of herbaceous flora contributes to the opportunity for the taxonomic evaluation of and fills knowledge gaps in studies of herbaceous flora identification using classical microscopic taxonomic tools for their accurate identification. RESEARCH HIGHLIGHTS: Pollen in unexplored herbaceous flora of the Samarkand region was studied with light and scanning electron microscopic pollen study. There is a high variation in observed pollen micromorphological characters. Pollen microscopic morphology has important taxonomic value for the identification of herbaceous species.

Structural and optical characterization of dilute Bi-doped GaN nanostructures grown by molecular beam epitaxy

We have carried out detailed studies on the epitaxy and characterization of dilute Bi-doped GaN nanostructures. A comprehensive investigation of Bi-doped GaN nanowires and quasi-film epitaxial growth conditions has been performed. Scanning electron microscopy studies show that lowering the GaBiN growth temperature causes gradual changes in top c-plane nanowire morphology due to the incremental incorporation of foreign Bi atoms. This trend is further substantiated by the secondary ion mass spectroscopy analysis of a multi-layer Bi-doped GaN quasi-film. However, it is also found that the amount of Bi incorporation into the GaN lattice is relatively independent of the N2 flow rate variation under the growth conditions investigated. Furthermore, room-temperature micro-Raman spectra show that there are additional peaks near 530, 650, and 729 cm−1 wave numbers in the Bi-doped GaN samples, which can primarily be attributed to Bi local vibrational modes, indicative of a small amount of Bi incorporation in the GaN lattice. Moreover, phonon calculations with density functional theory indicate that Bi replacing the N sites is the likely origin of the experimentally measured Raman modes. X-ray photoelectron spectroscopy measurements have also been obtained to deduce the electronic interaction between the Bi dopant atom and the GaN nanostructure. Such one-dimensional nanowires permit the synthesis of dislocation-free highly mismatched alloys due to strain relaxation, allowing efficient light absorption and charge carrier extraction that is relevant for solar energy harvesting and artificial photosynthesis.

Microwave-assisted synthesis of SnO2:ZnO nanocomposites for photocatalytic, antimicrobial and electrochemical urea detection applications

In this work, we have synthesized SnO2:ZnO nanocomposites (0.25, 0.5, 0.75, and 1 M ZnO) by employing an efficient microwave-assisted synthesis method. The synthesized nanocomposite's structural, morphological, and optical characteristics are examined using different physicochemical techniques. The X-ray diffraction patterns revealed that the SnO2 and ZnO nanoparticles crystallize in tetragonal and hexagonal crystal systems, respectively. This observation is further substantiated by the results obtained in the Raman analysis. The Field Emission Scanning Electron Microscope study of SnO2:ZnO nanocomposites (NCs) reveals a few rod-shaped nanoparticles as well as big, irregularly shaped particles of reduced size. Additionally, the absorption edge of diffuse reflectance UV–visible spectra exhibits a red shift, and the band gap value of SnO2:ZnO NCs at equal proportion is determined to be 3.3 eV. In the presence of hydrogen peroxide (H2O2), the photocatalytic degradation efficiency of the synthesized nanocomposites is investigated for different dyes. With a degradation efficiency of 98 %, the nanocomposites tend to be more reactive towards crystal violet dye (20 ppm) than the other dyes while adding 20 mg of synthesized SnO2:ZnO NCs in equal proportions. The impact of pH and reactive oxygen species involved in the degradation process is also tested. SnO2:ZnO material showed nearly similar degradation efficiency even after six recycles. The study of electrochemical detection of urea employing SnO2:ZnO NCs showed a two-fold increase in peak current value with a detection limit between 0.05 and 4 mM urea. In addition, Escherichia coli and Bacillus subtilis strains were used to test the nanocomposite's antibacterial capabilities, which showed promise as potential antimicrobial agents.

SEM Studies Assessing the Efficacy of Laser Treatment for Primary Teeth: A Systematic Review

Treating and limiting caries among young children are crucial issues for pediatric dentistry. In our systematic review, the authors intend to assess alterations in the surfaces of primary teeth following laser treatment using Scanning Electron Microscopy (SEM). The aim of this article is to systematically review and consolidate existing knowledge regarding the use of SEM imaging to assess the efficacy of laser treatment for primary teeth. On 10 November 2023, an electronic search was systematically conducted across PubMed, Cochrane, Web of Science, and Scopus databases with keywords ((laser) AND ((primary teeth) OR (deciduous teeth)) AND (SEM)). The initial pool consisted of 205 records, from which 93 duplicates were eliminated. After careful examination of the remaining articles, 24 records were included in this systematic review. The majority of articles suggest that laser treatment provides dentinal surface without a smear layer, enhances remineralization of enamel, and improves the bonding quality of resin restorations. However, some discrepancies are still present. Based on the gathered articles, the authors of this review have concluded that laser treatment could be applied to deciduous teeth in terms of caries treatment and remineralization although further research is still needed.