Microscopy Techniques Research Articles

Physical properties and hydration behaviors of paste casting brick containing coal gasification slag (CGS): Effect of curing condition and CGS dosage

In the process of developing coal chemical technologies, it is necessary to address environmental pollution and resource waste caused by the associated solid waste coal gasification slag (CGS). This study investigated the feasibility of using CGS as a substitute for fly ash (FA) in the preparation of paste casting bricks. The effects of curing conditions and CGS dosages on the physical properties of the specimens were investigated and related to the hydration behaviors through various microscopic techniques. The results showed that the occurrence of electrostatic flocculation and the enrichment of active substances increased the yield stress of the slurry as the CGS replacement rose, which manifested as decreased fluidity at the macroscopic level. The secondary hydration reaction was facilitated with the increased CGS replacement rate due to the desirable hydraulic activity of CGS. XRD, FTIR and TG results corroborated that the content of hydration products which contributed to strength development were enhanced with the addition of CGS under different curing conditions. XRD and SEM-EDS results indicated that the doping of elements such as Mg and Al under autoclaved condition led to a reduction in the grain size of tobermorite, and the micro-morphology tended to concentrate stresses under pressure. The results of this study promote the resourceful utilization of CGS in building materials and lay the foundation for further scale-up industrial application.

Playing with active matter

In the past 20 years, active matter has been a very successful research field, bridging the fundamental physics of nonequilibrium thermodynamics with applications in robotics, biology, and medicine. Active particles, contrary to Brownian particles, can harness energy to generate complex motions and emerging behaviors. Most active-matter experiments are performed with microscopic particles and require advanced microfabrication and microscopy techniques. Here, we propose some macroscopic experiments with active matter employing commercially available toy robots (the Hexbugs). We show how they can be easily modified to perform regular and chiral active Brownian motion and demonstrate through experiments fundamental signatures of active systems such as how energy and momentum are harvested from an active bath, how obstacles can sort active particles by chirality, and how active fluctuations induce attraction between planar objects (a Casimir-like effect). These demonstrations enable hands-on experimentation with active matter and showcase widely used analysis methods.

Engineered Cementitious Composite with Nanocellulose and High-Volume Fly Ash

This research develops a sustainable Engineered Cementitious Composites (ECC) with reduced cement usage by incorporating high volume fly ash (HVFA) and silica fume, along with the novel application of nanocellulose (NC), a plant-based nanomaterial, and hybrid fibres to achieve high strength and ductility simultaneously. 12 mixes were developed including three base ECC mixes with 1.5% polyethylene (PE) and 0.5% steel fibres with varying proportions of fly ash and silica fume (1.2:0-1:0.2) and nine NC reinforced ECC mixes with varying dosages of NC (0.15%, 0.2%, 0.25% by weight). The effect of fly ash/silica fume ratio and NC on mechanical properties was investigated through compressive and uniaxial tensile tests. Scanning electron microscope (SEM) and differential scanning calorimetry (DSC) techniques were utilized to gain insights into the HVFA and NC matrix systems and NC and hybrid fibre mechanism. Results showed that reducing the fly ash/ silica fume ratio increased strength but reduced tensile strain. Incorporating NC improved strength across all mixes, irrespective of fly ash/silica fume content, with the mix containing 0.2% NC showing the highest improvement. This novel ECC is anticipated to offer a sustainable and high-performance material solution for engineering structures.

Novel 3D plate-like g-C3N4/BiOCl heterojunction as a highly efficient photocatalyst for the degradation of carbofuran in wastewater under visible light irradiation

The g-C3N4/BiOCl (gCN-BCl) heterojunction photocatalyst was synthesized using a low-temperature precipitation method for effective photocatalytic degradation of carbofuran (CBF). All gCN-BCl composites demonstrate greater efficacy in removing CBF compared to its individual constituents. The synergistic effect of incorporating the 0D structured BiOCl onto the 2D structured g-C3N4 was comprehensively examined using various microscopic, X-ray, and spectroscopic analytical techniques. Additionally, optical and photoelectrochemical analyses were conducted. The findings validated that the interaction between the two semiconductors at the heterointerfaces enhanced remarkable physical and structural stability, promoted high charge separation and transfer properties, and improved photocatalytic degradation. Under optimal conditions, 5-gCN-BCl (0.25 g/L) achieved a CBF (5 mg/L) removal efficiency of 95.7 % under visible light irradiation of 120 min, achieving 3.1- and 5.9-times higher degradation rate than the pure BiOCl and g-C3N4, respectively. The radical trapping experiments indicated that the h+ and •O2− were the primary reactive species involved in the CBF degradation. Furthermore, the potential toxicity of CBF and its intermediates was assessed, revealing that the photocatalytic degradation process significantly lowered the ecotoxicity of pesticide wastewater. The potency of 5-gCN-BCl was also evaluated in tap water and real wastewater samples, with CBF degradation efficiencies of 85.8 %, 47.6 %, and 38.7 % in tap water, municipal, and pesticide industry wastewater, respectively. Additionally, artificial neural network (ANN) modeling was employed to predict and optimize the photocatalytic degradation process, providing further insights into the system’s performance. The outcomes of this work offer valuable insights into the development of heterojunction photocatalysts with superior stability and efficacy for eliminating pesticides from water bodies.

Initial stages of silver electrodeposition on a model Pt(111) single-crystal substrate from ethaline

Deep eutectic solvents (DES) are a new class of solvents with unique properties that are very promising media for the electroplating of metals and alloys. Knowledge about the regularities of metal electrodeposition is noticeably promoted by studies on model single crystal electrodes with a known well-ordered surface structure. In this work, we investigate the regularities of under- and overpotential deposition (upd and opd, respectively) of silver from a silver chloride solution in ethaline on a Pt(111) single crystal surface. For a better understanding of the occurring processes, we employ a complex approach involving electrochemical and in situ and ex situ microscopic techniques. We show that the process of gradual surface poisoning is observed on Pt(111) in the potential range in which no massive solvent degradation is yet observed. We also observe that the extent of this process largely depends on the employed potential of contact between the electrode and the solution and the studied potential range.The presence of Ag upd on Pt(111) in ethaline is demonstrated using voltammetric and in situ STM data. The available results and charge analysis are used to compare the Ag upd processes in ethaline and in aqueous solutions. We discuss the number of Ag adlayers on Pt(111), the effect of the potential of initial contact of the electrode with the solution and cycling history, and the possibility of anion upd and formation of coadsorbate between Ag adatoms and upd chloride anions (chlorine adatoms). We also demonstrate that upd Ag is not completely desorbed until high anodic potentials, where it seems to catalyze the solvent oxidation. Phase deposition of silver from ethaline on Pt(111) starts at almost zero overpotentials, which is probably related to the presence of the already deposited Ag adlayer. Even at very low overpotentials the deposit includes both large planar 2D crystallites and 3D crystallites formed on the surface defects and at the edges of the flat deposit islands. As the overpotential grows, the epitaxiality is gradually lost; the deposit becomes unshaped and the amount of 3D crystallites and their height increase

Prop-1-ene-1,3-sultone as interfacial-engineering additive in nonflammable electrolyte for 4.45 V LiCoO2/Si-Graphite lithium-ion batteries with high performance

To achieve high energy density for lithium-ion batteries, employing high-voltage cathodes and Si-based anodes is available. Fluoroethylene carbonate-based electrolytes show potential for use in high-voltage lithium-ion batteries due to their superior oxidation stability. However, fluoroethylene carbonate is prone to reductively decompose on the anode and brings about adverse effects on the battery performance. In this work, prop-1-ene-1,3-sultone is incorporated as an efficacious film-forming additive into fluoroethylene carbonate/dimethyl carbonate electrolyte for the purpose of ameliorating the compatibility with Si-Graphite anode in high-voltage lithium-ion batteries. The flame retardant (ethoxy)pentafluorocyclotriphosphazene is also incorporated into the electrolyte to guarantee the nonflammable feature. This nonflammable electrolyte has an ideal conductivity higher than 8 mS cm−1 at 25 °C, and it grants competitive performances to a high-voltage LiCoO2/Si-Graphite pouch cell. This cell after 300 cycles test exhibits a capacity retention of over 80 % at 1C, and the discharge capacity at 8C exceeds 50 % of that at 1C. By virtue of X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy techniques, it is confirmed that prop-1-ene-1,3-sultone enhances interfacial properties of Si-Graphite anode and contributes to an optimized interface, which restrains the volume expansion of Si-Graphite and inhibits persistently reductive decomposition of electrolytes.

An aged-related structural study of DHPR tetrads in peripheral couplings of human skeletal muscle.

Among the numerous changes that occur in skeletal muscle during aging, the reduced regeneration potential after an injury is largely due to the impaired ability of satellite cells to proliferate and differentiate. Herein, using the freeze-fracture electron microscopy technique, we analyzed both the incidence and size of dihydropyridine receptors (DHPRs) tetrads (4 particles) in cultured myotubes from a young subject (28 years) after 9 days of differentiation and from an old subject (71 years) after 9 and 12 days of differentiation. Compared to young myotubes, at 9 days of differentiation old myotubes exhibited: i) a lower incidence and a smaller size of DHPR clusters and ii) a lower number of complete tetrads. At 12 days of differentiation values of incidence, size and number of complete tetrads in old myotubes were instead comparable with those of young myotubes at 9 days of differentiation. Collectively, these results indicate that in aged myotubes the synthesis process of the proteins involved in the excitation-contraction coupling mechanism, such as the DHPR, is somehow slowed, supporting previous studies evidence of a decrease in the differentiation potential of myotubes from elderly individuals.

Statistical Design and Analysis for Enhanced Production of Tetracycline‐Conjugated Copper Oxide Nanoparticles with Improved Antimicrobial Properties

AbstractPurpose: Since decades, numerous antibiotics have been used to treat different bacterial illnesses; among these, tetracycline is one of the commonly used antibiotics, which has led to development of bacterial resistance. To tackle this critical issue, we have developed a novel, biocompatible nanodrug that improves the antibacterial activity of tetracycline by conjugating it with copper oxide nanoparticles, thereby addressing the problem of multidrug resistance in bacteria. Methods: In this study, using unipot approach, tetracycline conjugated copper oxide nanoparticles were synthesized where tetracycline act as reducing as well as stabilizing agent. These nanoparticles were characterized by different analytical and microscopic technique. For statistical analysis, FFD and CCD model were employed to assess the effect of various parameters (concentration, pH, temperature and time). Results: The synthesis of nanoparticles was confirmed through different techniques. Synthesized nanoparticles exhibited the highest antibacterial activity against various microbes including multi‐drug resistant microbes compared to its individual constituents. DPPH and ABTS assays revealed high antioxidant activity of nanoparticles whereas, biocompatibility was assessed via MTT assay. The drug release profile confirms the sustained release of tetracycline molecules. Conclusions: We have successfully developed tetracycline conjugated copper oxide nanoparticles exhibiting potent antibacterial, antioxidant and biocompatible activity.

Comparative Analysis of Mechanical Characteristics: Ultrasonically Compacted vs. Conventionally Additive Manufactured Polymeric Samples

This scientific paper presents a comparative analysis of the mechanical characteristics of PLA samples fabricated through conventional AM methods and AM then ultrasonically compacted. The study aims to assess the potential advantages and limitations of ultrasonic compaction of PLA AM samples, as a reinforcing manufacturing technique. The methodology involves the fabrication of PLA samples using AM processes, then ultrasonically compact part of them to make a comparative study on their mechanical characteristics, including tensile strength. Additionally, the surface morphology and internal microstructure of the samples are analysed using microscopy techniques. The results of the study provide insights into the mechanical performance and structural integrity of the ultrasonically compacted samples compared to the conventionally PLA AM samples. The findings highlight any potential improvements or limitations in terms of mechanical properties, such as strength, durability, and overall performance.

Ultrafast Charge and Exciton Diffusion in Monolayer Films of 9-Armchair Graphene Nanoribbons.

Determining the electronic transport properties of graphene nanoribbons is crucial for assessing their suitability for applications. So far, this has been highly challenging both through experimental and theoretical approaches. This is particularly the case for graphene nanoribbons that are prepared by chemical vapor deposition, which is a scalable and industry-compatible bottom-up growth method that results in closely packed arrays of ribbons with relatively short lengths of a few tens of nanometers. In this study, the experimental technique of spatiotemporal microscopy is applied to study monolayer films of 9-armchair graphene nanoribbons prepared using this growth method, and combined with linear-scaling quantum transport calculations of arrays of thousands of nanoribbons. Both approaches directly resolve electronic spreading in space and time through diffusion and give an initial diffusivity approaching 200 cm2 s-1 during the first picosecond after photoexcitation. This corresponds to a mobility up to 550 cm2 V-1 s-1. The quasi-free carriers then form excitons, which spread with a diffusivity of tens of cm2 s-1. The results indicate that this relatively large charge carrier mobility is the result of electronic transport not being hindered by defects nor inter-ribbon hopping. This confirms their suitability for applications that require efficient electronictransport.

Giant Uniaxial Magnetocrystalline Anisotropy in SmCrGe3.

Magnetic anisotropy is a crucial characteristic for enhancing the spintronic device performance. The synthesis of SmCrGe3 single crystals through a high-temperature solution method has led to the determination of uniaxial magnetocrystalline anisotropy. Phase verification was achieved by using scanning transmission electron microscopy (STEM), powder, and single-crystal X-ray diffraction techniques. Electrical transport and specific heat measurements indicate a Curie temperature (TC) of approximately 160 K, while magnetization measurements were utilized to determine the anisotropy fields and constants. Curie-Weiss fitting applied to magnetization data suggests the contribution of both Sm and Cr in the paramagnetic phase. Additionally, density functional theory (DFT) calculations explored the electronic structures and magnetic properties of SmCrGe3, revealing a significant easy-axis single-ion Sm magnetocrystalline anisotropy of 16 meV/fu. Based on the magnetization measurements, easy-axis magnetocrystalline anisotropy at 20 K is 13 meV/fu.

The role of BaTiO3 nanoparticles as photocatalysts in the synthesis and characterization of novel fruit dyes is investigated.

In the present work, the photocatalytic activity against the natural dye extracted from the novel fruits has been studied by the BaTiO3 nanoparticles (NPs) under a ultra-violet (UV) light source. The large concentrations of an essential phenolic agent present in this phytochemical extract superimposed with cloths fibers make strong stain and degrade into another form of toxic, which is excluded from the many textiles industries as the colorful waste waters without recycling and removal of that dye pigments have been investigated using both photodegradation and photoluminescence techniques. The entitled nanoparticles (NPs) were prepared using the soft chemical root-modified solvothermal synthesis combo method and exposure to heat treatment such that the annealing process has been done for different temperatures ranging from 100°C to 250°C. As for as concern the characterization, as a start, structural and morphology studies have been reported here that highly crystalline oriented peaks data using powder x-ray diffraction techniques (PXRD) as well as the surface morphology including the size, shape, and mass distribution using the field emission scanning electron microscopy (FESEM) techniques, which purely belong to rutile tetragonal structure of the crystal system and circular and noncircular flakes like rough surface morphology materials respectively. The lattice dissociation constant 'ε' value of the BaTiO3 NPs has determined to be ~2.71 × 10-3 using the Williamson-Hall (W-H plot) analysis of crystallographic data. In the UV visible spectroscopy findings, since the extreme quantum confinement of BaTiO3 nanoflakes/nanodisc, the optical energy bandgap has been estimated to be a range of 1.98 to 2.67 eV (~2.48 eV) found from the Tauc plot analysis, which contributes to the significantly owing to the enhanced photocatalytic efficiency with excellent performance along exciton formation, superoxide ions, and hydroxyl free radicals generations under UV-vis light irradiation resulting in efficient degradation of typical novel fruit organic dye. Photoluminescence spectra observed at room temperature and low temperature have been observed for the BaTiO3 nanoflakes, which exhibit the blue emission due to the crystalline defects such as the appearance of Ba vacancies leads to the conceivable beginning of p-type conductivity and the origination of free exciton emission reveals the direct bandgap transition nature of nanoflakes. RESEARCH HIGHLIGHTS: According to our findings, 89.71% of the natural syzygium cumin is degraded by photocatalysis reaction. As a plausible mechanism for the destruction of natural dyes under solar light, photocatalytic destruction has been proposed. The reaction between these reactive free radical species leads to high efficiency photodegradation with a short decay time. In addition to water treatment and environmental cleaning applications, the excellent performance of this photocatalyst makes it a promising candidate for other applications. Hence, the synthesized BaTiO3 nanoflakes showcase a highly significant advancement towards the development of a textiles dye recycling method.

Investigating the Biological Efficacy of Albumin-Enriched Platelet-Rich Fibrin (Alb-PRF): A Study on Cytokine Dynamics and Osteoblast Behavior

The development of effective biomaterials for tissue regeneration has led to the exploration of blood derivatives such as leucocyte- and platelet-rich fibrin (L-PRF). A novel variant, Albumin-Enriched Platelet-Rich Fibrin (Alb-PRF), has been introduced to improve structural stability and bioactivity, making it a promising candidate for bone regeneration. This study aimed to evaluate Alb-PRF’s capacity for cytokine and growth factor release, along with its effects on the proliferation, differentiation, and mineralization of human osteoblasts in vitro. Alb-PRF membranes were analyzed using histological, scanning electron microscopy, and fluorescence microscopy techniques. Cytokine and growth factor release was quantified over seven days, and osteoinductive potential was evaluated with MG-63 osteoblast-like cells. Structural analysis showed Alb-PRF as a biphasic, highly cellularized material that releases lower levels of inflammatory cytokines and higher concentrations of platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) compared to L-PRF. Alb-PRF exhibited higher early alkaline phosphatase activity and in vitro mineralization (p < 0.05) and significantly increased the OPG/RANKL mRNA ratio (p < 0.05). These results indicate that Alb-PRF has promising potential as a scaffold for bone repair, warranting further in vivo and clinical assessments to confirm its suitability for clinical applications.

Evidence of renal tubular injury in canine patients after elective desexing.

To investigate the frequency of perioperative acute kidney injury (AKI) in American Society of Anesthesiologists (SA) Grade I canine patients undergoing elective desexing using urine microscopy techniques and assess if pre- and intraoperative factors affect risk of developing AKI. Prospective observational clinical study conducted between September 2020 and October 2020. University teaching hospital. Thirty-two female and four male dogs between 5 months and 5 years of age classified as ASA I undergoing elective desexing surgery. Urinalysis was performed preoperatively and 20-24 h postoperatively to identify markers of renal tubular injury (RTI), particularly the presence of granular and renal tubular epithelial cell (RTEC) casts on sediment analysis. Dogs underwent a full physical examination and a preoperative assessment including measurement of urine specific gravity (USG), packed cell volume (PCV), total plasma protein and serum creatinine (sCr) was conducted as a part of the desexing programme. Anaesthetic records were examined for any evidence of intraoperative hypotension, defined as a mean arterial pressure (MAP) of <60 mmHg for any duration of time. MAP was measured using an indirect oscillometric technique. For analysis, animals were subdivided into affected and nonaffected groups, with affected animals those that hadpostoperative increases in granular and RTEC casts. Categorical and comparative analyses were then performed between groups to identify associations of increased casts with pre-, intra- and postoperative variables. A frequency of RTI of 5.6% was identified. This was accompanied by a significant association between increases in casts with total duration (p = 0.027) and number (p = 0.016) of hypotensive episodes. RTI is an anaesthetic consideration in ASA I veterinary patients undergoing elective desexing surgery. The identification of an association between the total duration and number of hypotensive episodes and the frequency of RTI highlights the importance of early detection of hypotension along with prompt and effective intervention in veterinary patients.

Electrochemical boost via thermally reduced graphene oxide for tailoring composite paste electrodes

Carbon-based composite materials are employed in diverse electrochemical applications, such as in catalysis, (bio)molecular sensing, and energy storage. In practice, electrode material needs to be highly conductive to allow high-speed electron transference to electrolyte species and possess high-surface area to obtain greater measured signals and power capabilities, as well as long useful life and stability. In this sense, graphene derivatives emerge as interesting candidates, even more so if they constitute part of practical, economical and versatile paste electrodes.This work presents a detailed analysis of the electrochemical performance of paste electrodes fabricated with multilayer partially reduced graphene oxide (rGO). The rGO was strategically produced via thermal treatment as a key factor that minimizes both mass loss and energy consumption. The results obtained through diffraction, microscopy and spectroscopy techniques show an effective partial reduction in the range of 100 to 400 °C. Furthermore, the enhanced electrochemical performance of rGO was determined by exploring the specific capacitance from cyclic voltammetry (CV) and galvanostatic charge–discharge measurements (GCD) as well as charge transfer resistance via electrochemical impedance spectroscopy (EIS). Our results evidence how an integral performance with suitable chemical, structural and morphological properties achieved for GO heat-treated at 200 °C leads to an improved electronic conductivity when a small part is combined with graphite in paste electrodes. This latter combination provides higher versatility compared to other alternatives since it arises as an economical and effective carbonaceous matrix for (bio)electrochemical sensors, hybrid supercapacitors or other desired nanotechnological applications.

Thermal stability and anti-ablation performance of plasma spray coated-YSZ on Al2TiO5 modified novel ablative carbon-phenolic composites

Abstract Despite ongoing challenges, ablative thermal protection systems are among the most promising methods for safeguarding spacecraft during re-entry thermal protection systems (TPS). A novel aluminium titanate (Al2TiO5/AT) and a highly efficient thermal barrier of coating (TB/TBCs) made from yttria-stabilized zirconia (YSZ), powder, but deposited using the plasma spray technique on polyacrylonitrile (PAN)-based carbon fiber fabric(C)-reinforced with resorcinol phenol formaldehyde resin (RF) composites (C-RF)) would be a potential candidate for TPS applications. This study investigates the composites with varying wt.% of AT that were developed, namely 0 wt.% (YSZ-C-RF), 1 wt.%, 3 wt.%, and 5 wt.% (YSZ-AT-C-RF) by utilizing a hot press moulding machine. Thermal stability and ablation performance of unmodified C-RF with modified YSZ-C-RF and YSZ-AT-C-RF composites are examined through thermogravimetric analysis (TGA) and oxyacetylene torch test/OAT (4.0 MW/m2 for 60 sec). Also, the phase composition and microstructure of the ablated surface are determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The TBC of YSZ has an obvious influence on the residual weight ratios at high temperatures in C-RF and also plays a positive role in increasing thermal stability under nitrogen atmosphere for enhancing ablation resistance concerning YSZ-C-RF. The mass and linear ablation rates (MAR and LAR) of the composites after modifying the surface by YSZ-coated particles are reduced by 82.98% and 15.65%, respectively. Similarly, the introduction of AT particles and TBC of YSZ results in evidence of improving the thermal stability and the ablation resistance in varying wt.% of YSZ-AT-C-RF composites. The primary optimum AT weight loading for enhancing ablation resistance in YSZ-C-RF composites is 1wt.%. The modification of 1wt.% AT particles and YSZ-Coated particles reduce MAR and LAR by 54.79% and 61.94%, respectively. This work offers a meaningful method to remarkably enhance the ablation performance of the modified C-RF and YSZ-AT-C-RF composites.&amp;#xD;

Studies of Protein Phase Separation Using Leishmania Kinetoplastid Membrane Protein-11.

Despite the significant understanding of phase separation in proteins with intrinsically disordered regions, a considerable percentage of proteins without such regions also undergo phase separation, presenting an intriguing area for ongoing research across all kingdoms of life. Using a combination of spectroscopic and microscopic techniques, we report here for the first time that a low temperature and low pH can trigger the liquid-liquid phase separation (LLPS) of a parasitic protein, kinetoplastid membrane protein-11 (KMP-11). Electrostatic and hydrophobic forces are found to be essential for the formation and stability of phase-separated protein assemblies. We show further that the increase in the ionic strength beyond a threshold decreases the interchain electrostatic interactions acting between the alternate charged blocks, altering the propensity for phase separation. More interestingly, the addition of cholesterol inhibits LLPS by engaging the cholesterol recognition amino acid consensus (CRAC)-like domains present in the protein. This was further confirmed using a CRAC-deleted mutant with perturbed cholesterol binding, which did not undergo LLPS.

HIV-1 N-myristoylation-dependent hijacking of late endosomes/lysosomes to drive Gag assembly in macrophages.

Macrophages represent an important viral reservoir in HIV-1-infected individuals. Different from T cells, HIV-1 assembly in macrophages occurs at intracellular compartments termed virus-containing compartments (VCCs). Our previous research in HeLa cells - in which assembly resembles that found in infected T cells - suggested that late endosomes/lysosomes (LEL) play a role in HIV-1 trafficking towards its assembly sites. However, LEL's role during assembly at VCCs is not fully understood. Herein, we used the HIV-1-inducible cell line THP-1 GagZip as a model to study HIV-1 Gag intracellular trafficking and assembly in macrophages. We demonstrated LEL involvement at VCCs using various microscopy techniques and biochemical approaches. Live-cell imaging revealed that HIV-1 repositions LEL towards the plasma membrane and modulates their motility. We showed that Arl8bmediated LEL repositioning is not responsible of Gag trafficking to VCCs. Additionally, myristoylation inhibition by PCLX-001 decreased Gag presence on endosomes and inhibited VCCs formation, in both cell-line- and primary macrophages. In conclusion, we presented evidence supporting the idea that HIV-1 manipulates the LEL trajectory to guide Gag to VCCs in an N-myristoylation-dependent manner.

Analytical microscopy techniques using coaxial and oblique illuminations to detect thin glass particulates generated from glass vials for parenteral drug products

Glass vials are the most widely used primary containers for the packaging of parenteral products due to their optical clarity, general inertness, and hermetic properties, but under certain circumstances, they can pose safety concerns. Most of these issues are related to the potential formation of glass particulates through delamination or precipitation, resulting from the chemical interaction between the drug product and the inner surface of the glass vial. Hence, it is imperative for pharmaceutical companies to conduct product-vial compatibility studies to determine the appropriate packaging/container closure system. To support this development activity, scientists need to develop analytical methods to detect subvisible glass particulates in parenteral products, along with the appropriate positive controls, to facilitate detection and identification. This paper outlines the utilization of coaxial/episcopic and oblique illumination microscopy, combined with spectroscopic techniques, to detect thin glass particulates generated from a modified procedure. It also showcases the importance of angle-dependent lighting in visualizing positive control samples containing thin glass particulates. The analytical microscopy techniques discussed in this paper can assist scientists in selecting suitable container closure systems for developing parenteral products.

Unraveling the Origin of Elemental Chemical Shift and the Role of Atomic Hydrogen in a Surface Ullmann Coupling System.

The Ullmann coupling of aryl halides is a powerful method in the on-surface synthesis of functional materials. Understanding its basic aspects and influencing factors can aid in the use of this tool for the fabrication of intriguing structures. In this study, we unveil (1) the origin of the shift in the elemental binding energy (BE) and (2) the functions of atomic hydrogen (AH) in a typical Ullmann coupling system using combined spectroscopy and microscopy techniques. During debromination of the aryl halide precursor, the work function (WF) alteration is correlated with the surface Br amount. The WF change instead of C-Ag formation is proposed to play a dominant role in the shift of the molecular C 1s BE. AH dosing onto organometallic chains leads to chain decomposition and surface Br removal. In contrast, AH dosing onto covalent poly(para-phenylene) (PPP) chains results in superhydrogenation in addition to Br removal. The C 1s BE shift is attributed to both WF change and superhydrogenation effects. Thermal annealing restores the PPP chains by eliminating superhydrogenation, which causes the C 1s BE to shift to a high BE. This study provides deep insights into the mechanisms of Ullmann coupling on surfaces, highlighting the significant role of WF alterations and AH treatments in these processes.