Cytomorphological findings in confirmed cases of tubercular lymphadenitis.

Objective: Tuberculosis (TB) remains a major health problem, especially in the developing countries. Fine-needle aspiration cytology is the first line of investigation for tubercular lymphadenitis as it is easy to perform, less invasive, quick, and economical. The typical cytopathological features of tuberculosis TB include epithelioid cell granulomas with Langhans giant cells and caseous necrosis. The present study aimed to evaluate the cytomorphological features of newly diagnosed cases of tubercular lymphadenitis confirmed by GeneXpert. Material and Methods: This was a retrospective study in which all fine-needle aspirates from newly diagnosed cases of tubercular lymphadenitis confirmed by GeneXpert over a 1-year period from July 2022 to July 2023 were included in the study. The May-Grunwald-Giemsa stained smears from these aspirates were categorized into three patterns-epithelioid cell granulomas with necrosis, epithelioid granulomas without necrosis, and necrosis only. The granulomas were further categorized into well-formed, ill--formed, and splintered. The background of the aspirate which included a reactive lymphoid background, lymphocytes, eosinophils, and neutrophils was tabulated for all the cases. Results: Out of the three cytomorphological patterns, epithelioid granulomas with necrosis were the most predominant (67.5%), followed by necrosis only (20.8%) and granulomas without necrosis (11.6%). An acid-fast bacilli (AFB) positivity of 53.3% (64 cases) was seen on the Ziehl-Neelsen stain. Well-composed, poorly formed, and splintered granulomas were seen in 55 (57.9%), 42 (44.2%), and 21 (22.1%) cases, respectively. Neutrophils were the most common background population (42, 35%) followed by lymphocytes (36, 30%). Reactive lymphoid cells and eosinophils were seen in 12 (10%) and 3 (2.5%) cases, respectively. Conclusion: Fine-needle aspiration cytology is a rapid inexpensive minimally invasive test for tubercular lymphadenitis as epithelioid cell granulomas along with caseous necrosis are highly suggestive of TB. However, manual acid-fast AFB detection has a low sensitivity as is illustrated in the present study where only AFBwas demonstrated in only 53.3% of cases.

Direct inkjet writing of polylactic acid/ß-tricalcium phosphate composites for bone tissue regeneration: A proof-of-concept study.

There is an ever-evolving need of customized, anatomic-specific grafting materials for bone regeneration. More specifically, biocompatible and osteoconductive materials, that may be configured dynamically to fit and fill defects, through the application of an external stimulus. The objective of this study was to establish a basis for the development of direct inkjet writing (DIW)-based shape memory polymer-ceramic composites for bone tissue regeneration applications and to establish material behavior under thermomechanical loading. Polymer-ceramic (polylactic acid [PLA]/ß-tricalcium phosphate [ß-TCP]) colloidal gels were prepared of different w/w ratios (90/10, 80/20, 70/30, 60/40, and 50/50) through polymer dissolution in acetone (15% w/v). Cytocompatibility was analyzed through Presto Blue assays. Rheological properties of the colloidal gels were measured to determine shear-thinning capabilities. Gels were then extruded through a custom-built DIW printer. Space filling constructs of the gels were printed and subjected to thermomechanical characterization to measure shape fixity (Rf) and shape recovery (Rr) ratios through five successive shape memory cycles. The polymer-ceramic composite gels exhibited shear-thinning capabilities for extrusion through a nozzle for DIW. A significant increase in cellular viability was observed with the addition of ß-TCP particles within the polymer matrix relative to pure PLA. Shape memory effect in the printed constructs was repeatable up to 4 cycles followed by permanent deformation. While further research on scaffold macro-/micro-geometries, and engineered porosities are warranted, this proof-of-concept study suggested suitability of this polymer-ceramic material and the DIW 3D printing workflow for the production of customized, patient specific constructs for bone tissue engineering.

Pt-CsPbBr3 Perovskite Nanocrystal Heterostructures: All Epitaxial.

Designing heterostructures of soft ionic nanocrystals with metallic or covalent nanostructures having epitaxial junctions in solution poses several fundamental challenges. Hence, in spite of large successes in developing lead halide perovskite nanocrystals, the chemistry of formation of their facet-directive epitaxial growth of noble metals cannot be explored yet. To address this, herein, epitaxial heterostructures of orthorhombic CsPbBr3 and cubic Pt in multiple directional approaches are reported. Appropriate facets of perovskite nanocrystals and high-temperature reaction are the key parameters for obtaining such nanocrystal heterostructures. Interfacial planes at the junctions having ideal lattice matching helped in establishing the epitaxial relations of (110) of orthorhombic (space group Pbnm) CsPbBr3 with {020} of cubic Pt and again (011) of CsPbBr3 with {111} of Pt. These results provided strong fundamental insights that ionic halide perovskite nanostructures and materials having different crystal phases can be placed in a single building block with continuous sublattice structures.

Hydrosilylation of Terminal Alkynes Catalyzed by an Air-Stable Manganese-NHC Complex.

In recent years, catalysis with base metal manganese has received a significant amount of interest. Catalysis with manganese complexes having N-heterocyclic carbenes (NHCs) is relatively underdeveloped in comparison to the extensively investigated manganese catalysts possessing pincer ligands (particularly phosphine-based ligands). Herein, we describe the synthesis of two imidazolium salts decorated with picolyl arms (L1 and L2) as NHC precursors. Facile coordination of L1 and L2 with MnBr(CO)5 in the presence of a base resulted in the formation manganese(I)-NHC complexes (1 and 2) as an air-stable solid in good isolated yield. Single-crystal X-ray analysis revealed the structure of the cationic complexes [Mn(CO)3(NHC)][PF6] with tridentate N,C,N binding of the NHC ligand in a facile fashion. Along with a few known manganese(I) complexes, these Mn(I)-NHC complexes 1 and 2 were tested for the hydrosilylation of terminal alkynes. Complex 1 was proved to be an effective catalyst for the hydrosilylation of terminal alkynes with good selectivity toward the less thermodynamically stable ß-(Z)-vinylsilanes. This method provided good regioselectivity (anti-Markovnikov addition) and stereoselectivity (ß-(Z)-product). Experimental evidence suggested that the present hydrosilylation pathway involved an organometallic mechanism with manganese(I)-silyl species as a possible reactive intermediate.

Spontaneous hydrogen production using gadolinium telluride.

Developing materials for controlled hydrogen production through water splitting is one of the most promising ways to meet current energy demand. Here, we demonstrate spontaneous and green production of hydrogen at high evolution rate using gadolinium telluride (GdTe) under ambient conditions. The spent materials can be reused after melting, which regain the original activity of the pristine sample. The phase formation and reusability are supported by the thermodynamics calculations. The theoretical calculation reveals ultralow activation energy for hydrogen production using GdTe caused by charge transfer from Te to Gd. Production of highly pure and instantaneous hydrogen by GdTe could accelerate green and sustainable energy conversion technologies.

Low bandgap high entropy alloy for visible light-assisted photocatalytic degradation of pharmaceutically active compounds: Performance assessment and mechanistic insights.

The incessant accumulation of pharmaceutically active compounds (PhACs) in various environmental compartments represents a global menace. Herein, an equimolar high entropy alloy (HEA), i.e., FeCoNiCuZn, is synthesized via a facile and scalable method, and its effectiveness in eliminating four different PhACs from aqueous matrices is rigorously examined. Attributing to its relatively low bandgap and multielement active sites, the as-synthesized quinary HEA demonstrates more pronounced photocatalytic decomposition efficiency, towards tetracycline (86%), sulfamethoxazole (94%), ibuprofen (80%), and diclofenac (99%), than conventional semiconductor-based photocatalysts, under visible light irradiation. Additionally, radical trapping assays are conducted, and the dissociation intermediates are identified, to probe the plausible photocatalytic degradation pathways. Further, the end-products of FeCoNiCuZn-mediated photocatalysis are apparently non-toxic, and the HEA can be successfully recycled repeatedly, with no obvious leaching of heavy metal ions. Overall, the findings of this study testify the applicability of FeCoNiCuZn as a visible light-active photocatalyst, for treating wastewaters contaminated with PhACs.

Hexahedron Symmetry and Multidirectional Facet Coupling of Orthorhombic CsPbBr3 Nanocrystals.

The cube shape of orthorhombic phase CsPbBr3 nanocrystals possesses the ability of selective facet packing that leads to 1D, 2D, and 3D nanostructures. In solution, their transformation with linear one-dimensional packing to nanorods/nanowires is extensively studied. Here, multifacet coupling in two directions of the truncated cube nanocrystals to rod couples and then to single-crystalline rectangular rods is reported. With extensive high-resolution transmission electron microscopy image analysis, length and width directions of these nanorods are derived. For the seed cube structures, finding {110} and {002} facets has remained difficult as these possess the hexahedron symmetry and their size remains smaller; however, for nanorods, these planes and the ⟨110⟩ and ⟨001⟩ directions are clearly identified. From nanocrystal to nanorod formation, the alignment directions are observed as random (as shown in the abstract graphic), and this could vary from one to the other rods obtained in the same batch of samples. Moreover, seed nanocrystal connections are derived here as not random and are rather induced by addition of the calculated amount of additional Pb(II). The same has also been extended to nanocubes obtained from different literature methods. It is predicted that a Pb-bromide buffer octahedra layer was created to connect two cubes, and this can connect along one, two, or even more facets of cubes simultaneously to connect other cubes and form different nanostructures. Hence, these results here provide some basic fundamentals of seed cube connections, the driving force to connect those, trapping the intermediate to visualize their alignments for attachments, and identifying and establishing the orthorhombic ⟨110⟩ and ⟨001⟩ directions of the length and width of CsPbBr3 nanostructures.

Cobalt catalyzed chemoselective reduction of nitroarenes: hydrosilylation under thermal and photochemical reaction conditions.

Commercially available Co2(CO)8 was used as an effective catalyst for the hydrosilylation of nitroarenes under both thermal and photochemical conditions. A wide variety of nitroarenes with various functionalities were selectively reduced to aromatic amines. Syntheses of drug molecules expand the potential utility of this protocol. Experimental evidence suggested a radical pathway.

Azide-Alkyne Cycloaddition Catalyzed by Copper(I) Coordination Polymers in PPM Levels Using Deep Eutectic Solvents as Reusable Reaction Media: A Waste-Minimized Sustainable Approach.

Two air-stable copper(I)-halide coordination polymers 1 and 2 with NNS and NNO ligand frameworks were synthesized and successfully utilized as efficient catalysts in an important organic reaction, namely, copper-catalyzed azide-alkyne cycloaddition, which is generally conducted in a mixture of water and organic solvents. The azide-alkyne "click" reaction was successfully conducted in pure water at r.t. under aerobic conditions. Other green solvents, including ethanol and glycerol, were also effectively used. Finally, deep eutectic solvents as green and sustainable reaction media were successfully utilized. In deep eutectic solvents, complete conversion with excellent isolated yield was achieved in a short period of time (1 h) with low catalyst loading (1 mol %) at r.t. Full conversion could also be achieved within 24 h with ppm-level (50 ppm) catalyst loading at 70 °C. Optimized reaction conditions were used for the syntheses of a large number of 1,4-disubstituted 1,2,3-triazoles with various functionalities. Triazole products were easily isolated by simple filtration. The reaction media, such as water and deep eutectic solvents, were recovered and recycled in three consecutive runs. The limited waste production is reflected in a very low E-factor (0.3-2.8). Finally, the CHEM21 green metrics toolkit was employed to evaluate the sustainability credentials of different optimized protocols in various green solvents such as water, ethanol, glycerol, and deep eutectic solvents.

Manganese-Catalyzed Chemoselective Hydrosilylation of Nitroarenes: Sustainable Route to Aromatic Amines.

Herein we report efficient catalytic hydrosilylations of nitroarenes to form the corresponding aromatic amines using a well-defined manganese(II)-NNO pincer complex with a low catalyst loading (1 mol %) under solvent-free conditions. This base-metal-catalyzed hydrosilylation is an easy and sustainable alternative to classical hydrogenation. A large variety of nitroarenes bearing various functionalities were selectively transformed into the corresponding aromatic amines in good yields. The potential utility of the present catalytic protocol was demonstrated by the preparation of commercial drug molecules.

The effect of worked material hardness on stone tool wear.

The identification of ancient worked materials is one of the fundamental goals of lithic use wear analysis and one of the most important parts of understanding how stone tools were used in the past. Given the documented overlaps in wear patterns generated by different materials, it is imperative to understand how individual materials' mechanical properties might influence wear formation. Because isolating physical parameters and measuring their change is necessary for such an endeavor, controlled (rather than replicative) experiments combined with objective measurements of surface topography are necessary to better grasp how surface modifications formed on stone tools. Therefore, we used a tribometer to wear natural flint surfaces against five materials (bone, antler, beech wood, spruce wood, and ivory) under the same force, and speed, over one, three, and five hours. The study aimed to test if there is a correlation between surface modifications and the hardness of the worked material. We measured each raw material's hardness using a nano-indentation test, and we compared the surface texture of the flint bits using a 3D optical profilometer. The interfacial detritus powder was analyzed with a scanning electron microscope to look for abraded flint particles. We demonstrate that, contrary to expectation, softer materials, such as wood, create a smoother surface than hard ones, such as ivory.

Novel dual labelled nanoprobes for nanosafety studies: Quantification and imaging experiment of CuO nanoparticles in C. elegans.

Metal oxide nanoparticles have been extensively studied for their toxicological impacts. However, accurate tracing/quantification of the nanomaterials and their biological responses are difficult to measure at low concentrations. To overcome the challenge, we developed a dual-labelling technique of CuO nanoparticles with a stable isotope of 65Cu, and with rhodamine dye. In vivo experiments on C. elegans were performed using natural feeding of Rhodamine B isothiocyanate-(3 aminopropyl) triethoxysilane functionalized 65CuO nanoprobes (RBITC-APTES@65CuO) (size = 7.41 ± 1 nm) within the range of Predicted Environmental Concentration (PEC) of CuO nanoparticles in soil and sediments. Fluorescence emission (570 nm) was detected in the lumen of the intestine and the pharynx of C. elegans with no impact of nanoparticle exposure on the brood size and life span of worms. The ingested fluorescent labelled RBITC-APTES@65CuO nanoprobes did not enter the reproductive system and were distributed in the alimentary canal of C. elegans. Strong fluorescent signals from the ingested RBITC-APTES@65CuO nanoprobes were achieved even after 24 h of exposure demonstrating the high stability of these nanoprobes in vivo. The net accumulation measured of 65Cu in C. elegans after background subtraction was 0.001 µg mg-1 (3.52 %), 0.005 µg mg-1 (1.76 %) and 0.024 µg mg-1 (1.69 %) for an exposure concentration of 0.0284 µg mg-1, 0.284 µg mg-1, and 1.42 µg mg-1 of 65Cu, respectively. Using C. elegans as a model organism, we demonstrated that RBITC-APTES tagged 65CuO nanoparticles acted as novel nanoprobes for measuring the uptake, accumulation, and biodistribution through quantification and imaging the nanoprobes at a very low exposure concentration (65CuO concentration: 0.033 µg mg-1).

Equilibriums in Formation of Lead Halide Perovskite Nanocrystals.

Physical insights related to ion equilibrium involved in the synthesis of lead halide perovskite nanocrystals remain key parameters for regulating the phase stability and luminescence intensity of these emerging materials. These have been extensively studied since the development of these nanocrystals, and different reaction processes controlling the formation of CsPbX3 nanocrystals are largely understood. However, growth kinetics related to the formation of these nanocrystals have not been established yet. Hence, more fundamental understanding of the formation processes of these nanocrystals is urgently required. Keeping these in mind and emphasizing the most widely studied nanocrystals of CsPbBr3, different equilibrium processes involved in their synthesis for phase and composition variations are summarized and discussed in this Perspective. In addition, implementations of these findings for shape modulations by growth are discussed, and several new directions of research for understanding more fundamental insights are also presented.

Cs-Lattice Extension and Expansion for Inducing Secondary Growth of CsPbBr3 Perovskite Nanocrystals.

The increase of the stability of perovskite nanocrystals with respect to exposure to polar media, layers growth, or shelling with different materials is in demand. While these are widely studied for metal chalcogenide nanocrystals, it has yet to be explored for perovskite nanocrystals. Even growth of a single monolayer on any facet or on the entire surface of these nanocrystals could not be established yet. To address this, herein, a secondary growth approach leading to creation of a secondary lattice with subsequent expansion on preformed CsPbBr3 perovskite nanocrystals is reported. As direct layer growth by adding precursors was not successful, Cs-lattice extension to preformed CsPbBr3 nanocrystals was performed by coupling CsBr to these nanocrystals. Opening both {110}/{002} and {200} facets of parent CsPbBr3 nanocrystals, CsBr was observed to be connected with lattice matching to the {200} facets. Further with Pb(II) incorporation, the Cs-sublattices of CsBr were expanded to CsPbBr3 and led to cube-couple nanocrystals. However, as cubes in these nanostructures were differently oriented, these showed lattice mismatch at their junctions. This lattice mismatch though restricted complete shelling but successfully favored the secondary growth on specific facets of parent CsPbBr3 nanocrystals. Details of this secondary growth via lattice extension and expansion are microscopically analyzed and reported. These results further suggest that lead halide perovskite nanocrystals can be epitaxially grown under proper reaction design and more complex as well as heterostructures of these materials can be fabricated to meet the current demands.

The mineralogy and structure of use-wear polish on chert.

Polished edges of archaeological stone tools are commonly investigated to obtain information on the tools' uses in prehistory. Yet to this day, it remains unclear what exactly such polishes are and how they form. Answering these questions should allow the elaboration of new interpretative methods based on objective measurements. Two major competing hypotheses of polish formation have been proposed: abrasion and the formation of a thin amorphous film on the chert or flint surface. We employ reflectance infrared spectroscopy, a technique particularly sensitive to thin amorphous films, to investigate these two hypotheses. We found no added amorphous layer that would have formed upon friction against bone, antler, ivory or wood. Our observations suggest polish formation by abrasion, notwithstanding previous claims of added amorphous surface structures. This has implications for our understanding of the physical processes taking place during friction of chert and flint against different materials. Our results also open the possibility to propose new pathways for identifying different use-wear processes, based on the degree of abrasion.

α-Halo Ketone for Polyhedral Perovskite Nanocrystals: Evolutions, Shape Conversions, Ligand Chemistry, and Self-Assembly.

Bright lead halide perovskite nanocrystals, which have been extensively studied in the past 5 years, are mostly confined to a six faceted hexahedron (cube/platelet) shape. With variations of ligand, precursor, reaction temperature, and surface modification, their brightness has been enhanced and phase became stable, but ultimate nanocrystals still retained the hexahedron cube or platelet shape in most of the hot injection reactions. In contrast, by exploration of α-halo ketone in amine as a halide precursor, different shaped nanocrystals without compromising the photoluminescence quantum yield (PLQY) are reported. Confining to orthorhombic CsPbBr3, the obtained nanocrystals are stabilized by 12 facets ({200}, {020}, {112}) and led to 12 faceted rhombic dodecahedrons. These facets are absolutely different from six ({110}, {002}) equivalent facets of widely reported orthorhombic cube shaped CsPbBr3 nanocrystals. These also retained the colloidal and phase stability, as well as showed near unity PLQY. With further annealing, these are transformed to 26 faceted rhombicuboctahedrons by dissolving all their vertices. Importantly, these 12 faceted nanocrystals showed wide area self-assembly in most of the reactions. It has also been concluded that primary ammonium ions led to six faceted nanocrystals, but tertiary ammonium ions obtained in this case stabilized different group of facets. While perovskite nanocrystals were broadly confined to only nanocubes, these new nanocrystals with intense emission would certainly provide a new avenue for continuing their further research.

Hydrosilylation of Esters Catalyzed by Bisphosphine Manganese(I) Complex: Selective Transformation of Esters to Alcohols.

Selective and efficient hydrosilylations of esters to alcohols by a well-defined manganese(I) complex with a commercially available bisphosphine ligand are described. These reactions are easy alternatives for stoichiometric hydride reduction or hydrogenation, and employing cheap, abundant, and nonprecious metal is attractive. The hydrosilylations were performed at 100 °C under solvent-free conditions with low catalyst loading. A large variety of aromatic, aliphatic, and cyclic esters bearing different functional groups were selectively converted into the corresponding alcohols in good yields.

Doping the Smallest Shannon Radii Transition Metal Ion Ni(II) for Stabilizing α-CsPbI3 Perovskite Nanocrystals.

Red emitting α-CsPbI3 nanocrystals are highly phase sensitive to ambient exposure, and B-site doping with suitable cations is adopted as one of the most feasible approaches for their phase stability. There are several reports herein: Ni(II) ions having the smallest transition metal Shannon radii were explored for doping in these nanocrystals. This successfully stabilized the cubic phase and retained the intense emission of nanocrystals for nearly 2 months. Being the smallest ion, the halide octahedra in the perovskite lattice were expected to provide high restraint ability toward δ-CsPbI3. Comparing with postsynthesis iodide treatments, the importance of doping in high temperature reaction was discussed. Finally, these doped nanocrystals were explored for photovoltaic devices and showed comparable efficiency (9.1%) to different other similar doped nanocrystals. Hence, the finding reported here is a step forward for understanding the insights of phase stability of α-CsPbI3 perovskite nanocrystals.

Doping Mn(II) in All-Inorganic Ruddlesden-Popper Phase of Tetragonal Cs2PbCl2I2 Perovskite Nanoplatelets.

Doping Mn(II) in inorganic Ruddlesden-Popper phase Cs2PbCl2I2 perovskite nanoplatelets is reported. The host nanostructures were prepared with a calculative protocol taking the exact required composition of Cs(I) and Pb(II) and injecting the preformed mixed oleylammonium chlorides and iodides at optimized reaction temperature. Reactions were optimized with various halides and their mixtures, but the stable phase of the Cs2PbX4 system was obtained only for the chloride-iodide mixed-halide system. Introduction of Mn(II) along with Pb(II), resulted in successful light-emitting doped nanocrystals. Measuring the photoluminescence and the decay lifetimes at room and liquid nitrogen temperatures, the variations in the excitonic, self-trapped, and Mn dopant emission properties were compared with those of the chalcogenide and perovskite nanocrystals.