Formation Of Rods Research Articles

Initial Stages of the Formation of the Supramolecular Structure of Ca and Mg Oxides

The optimal geometries of (CaO)n and (MgO)n clusters at n = 2–30 have been found and the enthalpies of formation of 1D, 2D, and 3D structures have been determined using quantum-chemical DFT calculations. The calculation demonstrates that the formation of linear chains of Ca and Mg oxides practically does not occur, while the formation of two-dimensional (tiled) and three-dimensional (cubic) structures proceeds with a large release of energy. The competing process of formation of molecular rods consisting of planar six-membered rings (MO)3 has been considered, and it has been shown to proceed not through the stage of preliminary formation of six-membered rings, but directly from monomer units.

UNILATERAL RHINITIS AND HEMOBARTONELLA FELIS INFECTION IN DOMESTIC CATS WITH A HISTORY OF CHRONIC KIDNEY DISEASE

Rhinitis is an inflammation of the mucous membranes of the nasal cavity, which can arise from a number of intranasal or systemic disorders. Hemobartonella felis is a gram-negative intracellular bacterium that attacks cat's erythrocytes. This treatment aims to discuss diagnostic and treatment techniques for rhinitis and Hemobartonellosis infection in cat with kidney failure. The animal is a local cat with a history of kidney failure, female, 6 years old and weighing 2.7 kg. The owner came with complaints of a serous discharge in the right nasal cavity and occasional sneezing. The cat has decreased appetite since 6 months and looks weak. Clinical examination showed swelling of the right mandibular lymph nodes and inspection of the oral cavity found gingivitis, tartar, and halitosis. Routine hematological examination results showed that the cat had macrocytic hypochromic anemia accompanied by thrombocytopenia. Examination of the blood smear preparations found coccoid formations with short chains or rod formations in the cat's erythrocytes which indicated a positive result for Hemobartonella felis. Case animal was diagnosed with unilateral rhinitis and Hemobartonella felis infection. The therapy given consisted of Doxycycline antibiotics at a dose of 10 mg/kg once a day for 14 days, anti-inflammatory Dexamethasone at a dose of 0.5 mg once a day for 5 days and Sangobion as a supportive therapy 1 capsule once a day for 10 days. The therapy given helps to improve the condition of the case animal. General check up of health conditions is required during the maintenance period.

Different Cooling Histories of Ultrahigh-Temperature Granulites Revealed by Ti-in-Quartz: An Electron Microprobe Approach

The cooling history of granulite is crucial to understanding tectonic scenarios of the continental crust. Ti-in-quartz, a useful indicator of temperature, can decipher the thermal evolution of crustal rocks. Here we apply the Ti-in-quartz (TitaniQ) thermometer to ancient ultrahigh-temperature (UHT) granulites from the Khondalite Belt (KB) in the North China Craton (NCC) and young UHT granulites from the Mogok Metamorphic Belt (MMB), Myanmar. Ti content in quartz was analyzed using a highly precise method constructed in a CAMECA SXFive electron probe microanalyzer (EPMA). The granulites from the two localities show different quartz Ti contents with a constant deforced beam of 10 μm. Matrix quartz and quartz inclusions from the NCC granulites have 57–241 ppm and 65–229 ppm, respectively, corresponding to the TitaniQ temperatures of 653–810 °C and 666–807 °C. The calculated temperatures are significantly lower than the peak temperatures (850–1096 °C) obtained by other methods, due to the formation of abundant rutile exsolution rods in quartz during cooling. Thus, the low calculated temperatures for the NCC granulites reflect a cooling state near or after the exsolution of rutile from quartz, most likely caused by a slow cooling process. However, the matrix quartz from the MMB granulites is exsolution-free and records higher Ti contents of 207–260 ppm and higher metamorphic temperatures of 894–926 °C, close to the peak UHT conditions. This feature indicates that the MMB granulites underwent rapid cooling to overcome Ti loss from quartz. Therefore, determining the amount of Ti loss from quartz by diffusion can provide new insight into the cooling behavior of UHT granulites. When a large deforced beam of 50 μm was used to cover the rutile rods, the matrix quartz in the KB granulites could also yield the TitaniQ temperatures above 900 °C. Thus, our new data suggest that the TitaniQ thermometer could be useful for revealing UHT conditions.

The CERV protein of Cer1, a C. elegans LTR retrotransposon, is required for nuclear export of viral genomic RNA and can form giant nuclear rods.

Retroviruses and closely related LTR retrotransposons export full-length, unspliced genomic RNA (gRNA) for packaging into virions and to serve as the mRNA encoding GAG and POL polyproteins. Because gRNA often includes splice acceptor and donor sequences used to splice viral mRNAs, retroelements must overcome host mechanisms that retain intron-containing RNAs in the nucleus. Here we examine gRNA expression in Cer1, an LTR retrotransposon in C. elegans which somehow avoids silencing and is highly expressed in germ cells. Newly exported Cer1 gRNA associates rapidly with the Cer1 GAG protein, which has structural similarity with retroviral GAG proteins. gRNA export requires CERV (C. elegans regulator of viral expression), a novel protein encoded by a spliced Cer1 mRNA. CERV phosphorylation at S214 is essential for gRNA export, and phosphorylated CERV colocalizes with nuclear gRNA at presumptive sites of transcription. By electron microscopy, tagged CERV proteins surround clusters of distinct, linear fibrils that likely represent gRNA molecules. Single fibrils, or groups of aligned fibrils, also localize near nuclear pores. During the C. elegans self-fertile period, when hermaphrodites fertilize oocytes with their own sperm, CERV concentrates in two nuclear foci that are coincident with gRNA. However, as hermaphrodites cease self-fertilization, and can only produce cross-progeny, CERV undergoes a remarkable transition to form giant nuclear rods or cylinders that can be up to 5 microns in length. We propose a novel mechanism of rod formation, in which stage-specific changes in the nucleolus induce CERV to localize to the nucleolar periphery in flattened streaks of protein and gRNA; these streaks then roll up into cylinders. The rods are a widespread feature of Cer1 in wild strains of C. elegans, but their function is not known and might be limited to cross-progeny. We speculate that the adaptive strategy Cer1 uses for the identical self-progeny of a host hermaphrodite might differ for heterozygous cross-progeny sired by males. For example, mating introduces male chromosomes which can have different, or no, Cer1 elements.

Microstructural characteristics and mechanical performances of Al–Si–Cu–Mg-(Ge) alloys prepared under 5GPa-level pressure

The influence of 5 GPa-level high pressure on the microstructure and mechanical properties of Al–7Si–3Cu-0.4 Mg and Al–7Si–3Cu-0.4Mg-0.5Ge alloys is investigated. It is found that α-Al dendrites disappear owing to the enhanced growth interfacial stability induced by high pressure. Unconventional nanocrystalline eutectics emerge in the intragranular region, while Si phases in all forms of eutectics display significantly modified structures. The pressure-induced influence on the microstructure evolution of alloy is further explored concerning thermodynamics and kinetics changes. After the direct aging treatment, fine Si particles precipitate densely and uniformly along the <100>Al directions in the Al matrix in both alloys. The APT analysis shows that these Si precipitates are enriched with Mg and segregated by Cu. The role of enhanced solid solubility and solute interactive effect on the formation of nanoscale Si rods is demonstrated. The Al–7Si–3Cu-0.4 Mg alloy fabricated under 5 GPa exhibits the highest compressive strength of 863.6 MPa and microhardness of 214.3 HV after aging. The findings reported in this paper provide a potential way to develop aluminum-silicon-based alloys with improved performance by introducing high pressure.

Development of Nitrate-Ion Selective Electrode (NO3-ISE) Based on Carbon from Disposal Battery

This research is related to the successfully well fabricated NO3-ISE sensor from battery waste disposal. Two types of material used, i.e., the battery waste taken from (i) graphite rods and (ii) carbon paste. The fabrication of NO3-ISE sensors from graphite rods only goes through two main processes, namely removal of impurities and the growth of the Polypyrrole layer doped with NO3 (PPy-NO3). While the NO3-ISE sensor prepared from carbon paste run through four stages, which include removal of impurities, the formation of graphite rod, dry-ing of graphite rod and formation of PPy-NO3 coating. However, both sensors produce the performance that are not much different with respect to Nernstian number between −58.8–(−60.8) mV dec−1 for graphite rods and −50.3–(−59.5) mV dec−1 based on carbon paste with a linear range of 0.1–10−4 M. The PPy-NO3 coating process on the surfaces of both graphite was carried out with a 16 cycles through Cyclic Voltammetry technique. Both sensors also exhibit considerable interferences from the IO3 − and Cl− ions, but show good selectivity against the H2PO4 − and SO4 2− ions. Both self-fabricated sensors have an accuracy that is comparable to the standard APHA method Ed.22nd 4500-NO3-E2012.

Untangling the Signatures of Acquired Sporadic Late Onset Nemaline Myopathy (SLONM) and Inherited Nemaline Myopathy (S7.001)

<h3>Objective:</h3> To identify biomarkers distinguishing acquired sporadic late onset nemaline myopathy (SLONM) from inherited nemaline myopathy (iNM) and investigate the pathophysiology leading to nemaline rod formation in these different disorders. <h3>Background:</h3> SLONM and iNM both feature accumulation of nemaline rods in muscle fibers. Unlike iNM, SLONM is amenable to therapy. The distinction between these disorders is therefore crucial, especially when the diagnosis remains ambiguous after initial clinical assessment and investigations. <h3>Design/Methods:</h3> Twenty-two muscle samples from patients affected by SLONM or genetically characterized iNM underwent quantitative histological analysis, laser capture microdissection for proteomic analysis of nemaline rod areas and rod-free areas, and transcriptomic analysis. <h3>Results:</h3> In all iNM samples, nemaline rods were found in subsarcolemmal or central aggregates, whereas they were diffusely distributed within muscle fibers in 70% of SLONM samples. In SLONM, muscle fibers harboring nemaline rods were smaller than those without rods, while the opposite was seen in iNM. Necrotic fibers, increased endomysial connective tissue, and atrophic fibers filled with nemaline rods were significantly more common in SLONM. Proteomic analysis detected 142 differentially expressed proteins between nemaline rod areas and rod-free areas across all samples. Comparing SLONM and iNM, fifty-one proteins were differentially expressed in nemaline rod areas and 10 proteins were differentially expressed in rod-free areas. These differentially expressed proteins implicated immune, structural, metabolic, and cellular processes in disease pathophysiology. Notably, immunoglobulin overexpression with accumulation in nemaline rod areas was detected in SLONM, supporting use of plasma cell-targeting chemotherapy for SLONM treatment. Transcriptomic analysis corroborated the proteomic findings and further revealed substantial gene expression differences between SLONM and iNM. <h3>Conclusions:</h3> We identified unique pathological and molecular signatures associated with SLONM and iNM, suggesting distinct underlying pathophysiological mechanisms. These findings are a critical step towards optimizing diagnostic tools that can better distinguish these disorders and accelerating SLONM treatment. <b>Disclosure:</b> The institution of Dr. Nicolau has received research support from Muscular Dystrophy association. The institution of Dr. Nicolau has received research support from American Brain Foundation. The institution of Dr. Nicolau has received research support from American Neuromuscular Foundation. Dr. Dasgupta has nothing to disclose. Prof. Dasari has nothing to disclose. Dr. Charlesworth has nothing to disclose. Mr. Johnson has received intellectual property interests from a discovery or technology relating to health care. Dr. Pandey has nothing to disclose. Dr. Doles has nothing to disclose. Dr. Milone has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Argenx. Dr. Milone has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Neurology Genetics, AAN. The institution of Dr. Milone has received research support from Mayo Clinic, CCaTS-CBD. The institution of Dr. Milone has received research support from Mayo Clinic, SGP Award. The institution of Dr. Milone has received research support from MDA for Care Center grant. The institution of Dr. Milone has received research support from Regenerative medicine Minnesota.

Understanding the Photocatalytic Activity of Sodium Hexatitanate Nanoparticles for Pollutants Degradation: A Spectroscopic Insight

Sodium hexatitanate (Na2Ti6O13) nanoparticles have been synthesized by the hydrothermal method with microwave and conventional heating, after which their photocatalytic properties toward an azo dye pollutant degradation have been investigated. Insights into the dynamics and reactivity of the species involved in the photocatalytic mechanism of the (Na2Ti6O13) samples were precisely investigated, for the first time, by X-band electron paramagnetic resonance (EPR) spectroscopy under different experimental conditions. X-ray diffraction structural analysis revealed that all samples crystallized in a monoclinic C2/m structure, with different short-range structural order according to the employed heating, as indicated by Raman. Field-emission scanning electron microscopy and transmission electron microscopy results revealed the formation of rod- and fiber-like nanoparticles with different diameters and lengths. EPR measurements indicated the presence of different Ti3+ point defects and F centers in the samples. X-ray photoelectron spectroscopy analysis proved the presence of oxygen-related defects, but no Ti3+ was detected on the surface. Spin trapping experiments monitored the generation of hydroxyl (OH·) radicals over UV-irradiation time. Various parameters contribute to the photocatalytic activity of the samples; however, the type of defect and particle morphology appeared as key factors for enhanced efficiency. Our study provides significant information about paramagnetic defects in Na2Ti6O13 materials and their role in photocatalysis to design other Ti-based photocatalysts.

Hydrothermal Synthesis of ZnO Superstructures with Controlled Morphology via Temperature and pH Optimization

Zinc oxide, as a widely used material in optics, electronics, and medicine, requires a complete overview of different conditions for facile and easily reproducible syntheses. Two types of optimization of ZnO hydrothermal preparation from zinc acetate and sodium hydroxide solution are presented, which allowed for obtaining miscellaneous morphologies of materials. The first was a temperature-controlled synthesis from 100 to 200 °C, using citric acid as a capping agent. The formation of hexagonal rods at the lowest temperature was evidenced, which agglomerated to flower-like structures at 110 and 120 °C. It was followed by transformation to flake-like roses at 160 °C, up to disordered structures composed of nanosized plates (>180 °C). The transformations were generated through a temperature change, which had an impact on the diffusion effect of hydroxide and citrate complexes. The second optimization was the hydrothermal synthesis free of organic additives and it included only a pH variation from 7.5 to 13.5. It was found that by utilizing a slow-dropping process and varying amounts of NaOH solutions, it is possible to obtain well-formed hexagonal pellets at pH 8.0-8.5. Strongly basic conditions of pH 11.0 and 13.5 impeded superstructure formations, giving small elongated particles of ZnO. All samples were characterized by high phase purity and crystallinity, with a specific surface area of 18-37 m2/g, whereas particle size distribution indicated a predominance of small particles (<1 μm).

ACTA1 H40Y mutant iPSC-derived skeletal myocytes display mitochondrial defects in an in vitro model of nemaline myopathy

Nemaline myopathies (NM) are a group of congenital myopathies that lead to muscle weakness and dysfunction. While 13 genes have been identified to cause NM, over 50% of these genetic defects are due to mutations in nebulin (NEB) and skeletal muscle actin (ACTA1), which are genes required for normal assembly and function of the thin filament. NM can be distinguished on muscle biopsies due to the presence of nemaline rods, which are thought to be aggregates of the dysfunctional protein. Mutations in ACTA1 have been associated with more severe clinical disease and muscle weakness. However, the cellular pathogenesis linking ACTA1 gene mutations to muscle weakness are unclear To evaluate cellular disease phenotypes, iPSC-derived skeletal myocytes (iSkM) harboring an ACTA1 H40Y point mutation were used to model NM in skeletal muscle. These were generated by Crispr-Cas9, and include one non-affected healthy control (C) and 2 NM iPSC clone lines, therefore representing isogenic controls. Fully differentiated iSkM were characterized to confirm myogenic status and subject to assays to evaluate nemaline rod formation, mitochondrial membrane potential, mitochondrial permeability transition pore (mPTP) formation, superoxide production, ATP/ADP/phosphate levels and lactate dehydrogenase release. C- and NM-iSkM demonstrated myogenic commitment as evidenced by mRNA expression of Pax3, Pax7, MyoD, Myf5 and Myogenin; and protein expression of Pax4, Pax7, MyoD and MF20. No nemaline rods were observed with immunofluorescent staining of NM-iSkM for ACTA1 or ACTN2, and these mRNA transcript and protein levels were comparable to C-iSkM. Mitochondrial function was altered in NM, as evidenced by decreased cellular ATP levels and altered mitochondrial membrane potential. Oxidative stress induction revealed the mitochondrial phenotype, as evidenced by collapsed mitochondrial membrane potential, early formation of the mPTP and increased superoxide production. Early mPTP formation was rescued with the addition of ATP to media. Together, these findings suggest that mitochondrial dysfunction and oxidative stress are disease phenotypes in the in vitro model of ACTA1 nemaline myopathy, and that modulation of ATP levels was sufficient to protect NM-iSkM mitochondria from stress-induced injury. Importantly, the nemaline rod phenotype was absent in our in vitro model of NM. We conclude that this in vitro model has the potential to recapitulate human NM disease phenotypes, and warrants further study.

Synthesis of tunable near infrared absorbance of gold nanorods (AuNRs) and their gold oxidation states during nanorod formation following by synchrotron based X-ray absorption spectroscopy (XANES)

A study of growth mechanism on AuNRs synthesized using seed-mediated method has been conducted via time resolved synchrotron based XAS. The synthesized AuNRs were characterized by TEM and UV–vis spectroscopy. It was found that the volume change of AgNO3 solution influenced their surface plasmon resonances (SPR) of AuNRs. An increase of silver ions concentration resulted in an increase of the aspect ratio (AR). For the growth mechanism investigation, time-resolved XANES in fluorescent mode and UV–vis measurement were employed. The potential growth mechanism was proposed according to the XANES spectrums. The reduction of Au(3+) oxidation state to Au(0) occurs after the reducing agent were added. The change in oxidation state of the AuNRs corresponded to the XANES spectrum of AuCl illustrating the oxidation states were reduced from Au(3+) to Au(+) then Au(0), respectively. Moreover, the rate of change in oxidation state depended on the AR. The formation of AuNRs was completed for the shorter rods (AR∼2.0) while the longer rods (AR∼4.2) still exhibit higher feature of oxidation state compared at the same reaction time. In addition, the change in absorbance from UV–vis spectrums revealed that AuNRs with AR∼2.0 took 50 min to complete rod formation which is faster than that of the AuNRs with AR∼4.2 (60 min). These UV–vis results were in a good agreement with the XANES spectrums. This finding leaded to conclude that the rod formation of AuNRs with lower AR could occurred faster than the formation of AuNRs with higher AR.

Rapid synthesis of bismuth-organic frameworks as selective antimicrobial materials against microbial biofilms.

Antibiotic resistance is a global public health threat, and urgent actions should be undertaken for developing alternative antimicrobial strategies and approaches. Notably, bismuth drugs exhibit potent antimicrobial effects on various pathogens and promising efficacy in tackling SARS-CoV-2 and related infections. As such, bismuth-based materials could precisely combat pathogenic bacteria and effectively treat the resultant infections and inflammatory diseases through a controlled release of Bi ions for targeted drug delivery. Currently, it is a great challenge to rapidly and massively manufacture bismuth-based particles, and yet there are no reports on effectively constructing such porous antimicrobial-loaded particles. Herein, we have developed two rapid approaches (i.e., ultrasound-assisted and agitation-free methods) to synthesizing bismuth-based materials with ellipsoid- (Ellipsoids) and rod-like (Rods) morphologies respectively, and fully characterized physicochemical properties. Rods with a porous structure were confirmed as bismuth metal-organic frameworks (Bi-MOF) and aligned with the crystalline structure of CAU-17. Importantly, the formation of Rods was a 'two-step' crystallization process of growing almond-flake-like units followed by stacking into the rod-like structure. The size of Bi-MOF was precisely controlled from micro-to nano-scales by varying concentrations of metal ions and their ratio to the ligand. Moreover, both Ellipsoids and Rods showed excellent biocompatibility with human gingival fibroblasts and potent antimicrobial effects on the Gram-negative oral pathogens including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Both Ellipsoids and Rods at 50​μg/mL could disrupt the bacterial membranes, and particularly eliminate P.gingivalis biofilms. This study demonstrates highly efficient and facile approaches to synthesizing bismuth-based particles. Our work could enrich the administration modalities of metallic drugs for promising antibiotic-free healthcare.

Molecular signatures of inherited and acquired sporadic late onset nemaline myopathies

Acquired sporadic late onset nemaline myopathy (SLONM) and inherited nemaline myopathy (iNM) both feature accumulation of nemaline rods in muscle fibers. Unlike iNM, SLONM is amenable to therapy. The distinction between these disorders is therefore crucial when the diagnosis remains ambiguous after initial investigations. We sought to identify biomarkers facilitating this distinction and to investigate the pathophysiology of nemaline rod formation in these different disorders. Twenty-two muscle samples from patients affected by SLONM or iNM underwent quantitative histological analysis, laser capture microdissection for proteomic analysis of nemaline rod areas and rod-free areas, and transcriptomic analysis. In all iNM samples, nemaline rods were found in subsarcolemmal or central aggregates, whereas they were diffusely distributed within muscle fibers in most SLONM samples. In SLONM, muscle fibers harboring nemaline rods were smaller than those without rods. Necrotic fibers, increased endomysial connective tissue, and atrophic fibers filled with nemaline rods were more common in SLONM. Proteomic analysis detected differentially expressed proteins between nemaline rod areas and rod-free areas, as well as between SLONM and iNM. These differentially expressed proteins implicated immune, structural, metabolic, and cellular processes in disease pathophysiology. Notably, immunoglobulin overexpression with accumulation in nemaline rod areas was detected in SLONM. Transcriptomic analysis corroborated proteomic findings and further revealed substantial gene expression differences between SLONM and iNM. Overall, we identified unique pathological and molecular signatures associated with SLONM and iNM, suggesting distinct underlying pathophysiological mechanisms. These findings represent a step towards enhanced diagnostic tools and towards development of treatments for SLONM.

Hydrophilic ionic liquid assisted hydrothermal synthesis of ZnO nanostructures with controllable morphology.

Nanostructured ZnO with controllable morphology was prepared by a hydrothermal method in the presence of three different hydrophilic ionic liquids (ILs), 1-ethyl-3-methylimidazolium methylsulfate, ([C2mim]CH3SO4), 1-butyl-3-methylimidazolium methylsulfate, ([C4mim]CH3SO4) and 1-ethyl-3-methylimidazolium ethylsulfate, ([C2mim]C2H5SO4) as soft templates. The formation of ZnO nanoparticles (NPs) with and without IL was verified using FT-IR and UV-visible spectroscopy. X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns indicated the formation of pure crystalline ZnO with a hexagonal wurtzite phase. Field emission scanning electron microscopic (FESEM) and high-resolution transmission electron microscopic (HRTEM) images confirmed the formation of rod-shaped ZnO nanostructures without using IL, whereas the morphology varied widely following addition of ILs. With increasing concentrations of [C2mim]CH3SO4, the rod-shaped ZnO nanostructures transformed into flower-shaped nanostructures whereas with rising concentrations of [C4mim]CH3SO4 and [C2mim]C2H5SO4 the morphology changed into petal- and flake-like nanostructures, respectively. The selective adsorption effect of the ILs could protect certain facets during the formation of ZnO rods and promote the growth in directions other than [0001] to yield petal- or flake-like architectures. The morphology of ZnO nanostructures was, therefore, tunable by the controlled addition of hydrophilic ILs of different structures. The size of the nanostructures was widely distributed and the Z-average diameter, evaluated from dynamic light scattering measurements, increased as the concentration of the IL increased and passed through a maximum before decreasing again. The optical band gap energy of the ZnO nanostructures decreased when IL was added during the synthesis which is consistent with the morphology of the ZnO nanostructures. Thus, the hydrophilic ILs serve as self-directing agents and soft templates for the synthesis of ZnO nanostructures and the morphology and optical properties of ZnO nanostructures are tunable by changing the structure of the ILs as well as systematic variation of the concentration of ILs during synthesis.

Lamella-rod pattern transition and confinement effects during eutectic growth

We present an in situ experimental study of the lamellar-to-rod transition during directional solidification of a model eutectic transparent alloy –the succinonitrile-(d)camphor (SCN-DC) system. Coupled-growth patterns, and their morphological transformations upon changes of the pulling velocity V (3.5−70.0nms−1) were observed in real time in a series of flat-wall samples with different thicknesses δ from 15 (thin samples) to 350 µm (thick samples). At relatively large velocity, rod-like patterns formed systematically. In contrast, stable lamellae were observed at sufficiently low velocity, regardless of the sample thickness in the investigated range. In confined-geometry samples (δ=30−140 µm), lamellar patterns were stable over a large range of the interphase spacing λ at low V. The lamella in contact with the sample walls were stabilized against a propagative breakup, and the formation of rods was mediated by secondary instabilities such as a zigzag mode and a spatial-oscillation mode. In the bistable range, a hysteresis upon increasing or decreasing V was observed, as well as complex phenomena involving oscillatory, mixed and hybrid patterns. The (reverse) transition from rods to lamellae involved a rod elongation instability. A discussion on the elementary mechanisms that determine the lamellar-rod transition, and their dependence on λ and V is initiated.

Cytoskeletal dysregulation and neurodegenerative disease: Formation, monitoring, and inhibition of cofilin-actin rods.

The presence of atypical cytoskeletal dynamics, structures, and associated morphologies is a common theme uniting numerous diseases and developmental disorders. In particular, cytoskeletal dysregulation is a common cellular feature of Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease. While the numerous activators and inhibitors of dysregulation present complexities for characterizing these elements as byproducts or initiators of the disease state, it is increasingly clear that a better understanding of these anomalies is critical for advancing the state of knowledge and plan of therapeutic attack. In this review, we focus on the hallmarks of cytoskeletal dysregulation that are associated with cofilin-linked actin regulation, with a particular emphasis on the formation, monitoring, and inhibition of cofilin-actin rods. We also review actin-associated proteins other than cofilin with links to cytoskeleton-associated neurodegenerative processes, recognizing that cofilin-actin rods comprise one strand of a vast web of interactions that occur as a result of cytoskeletal dysregulation. Our aim is to present a current perspective on cytoskeletal dysregulation, connecting recent developments in our understanding with emerging strategies for biosensing and biomimicry that will help shape future directions of the field.

Formation of actin–cofilin rods by depletion forces

Various stress conditions induce the formation of actin–cofilin rods in either the nucleus or the cytoplasm, although the mechanism of rod formation is unclear. In this study, we constituted actin–cofilin rods using purified actin, cofilin and actin interacting protein 1 (AIP1) in the presence of a physiological buffer containing a crowding agent, 0.8% methylcellulose (MC), which led to bundled actin filaments formed by depletion forces. Most of the F-actin bundles formed with methylcellulose were linear, whereas cofilin-bound F-actin bundles often had bent, looped, and often ring-like shapes. Increasing the amount of AIP1 shortened actin–cofilin bundles into rod-like bundles with tapering at both ends. As much shorter actin–cofilin filaments were formed in the presence of AIP1 before MC was added to the mixture, the rod-like bundle might be a mass of those short filaments. Furthermore, the small rods fused with each other to become larger rods, indicating that these rods were anisotropic liquid droplets. Several minutes after the addition of MC to the F-actin–cofilin–AIP1 mixture, we observed some long bundles in which the thick and thin parts appear alternately, reminiscent of a Plateau–Rayleigh instability observed in fluid columns. Simultaneously, we found images in which thin parts were interrupted, but the thick parts were arranged in a row in the longitudinal direction. These structures were also observed in cytoplasmic actin–cofilin rods in cells overexpressing cofilin–GFP, suggesting that cytoplasmic actin–cofilin rods have the same structure formation process as the rods reconstituted in vitro.

Amelioration of rectification properties of CuO nanostructures using surface modification

In the current work, CuO spherical and rod-shaped particles has been synthesized with help of co-precipitation technique. XRD studies reveal the presence of phase reversal of CuOH to CuO with single phase monoclinic structure. FT-IR analysis authenticates the occurrence of copper oxide nanostructures with the removal of nitrogen-based vibrations and organic species. FESEM micrographs reveals the formation of interlinked spherical and rod like structured CuO particles with an average size 57 nm. UV–Visible analysis unveils the optical bandgap reduction from 2.62 to 2.04 eV during annealing. XPS analysis portrays the dominant appearance of Cu2+ which confirms the formation of CuO particles inconsistence with XRD and FT-IR results. The improved performance of the prepared photodiode is obtained from I–V characteristics. The excellent optoelectronic properties of the developed photodiode make them suitable for future nano-electronics.

Group formation and collective motion of colloidal rods with an activity triggered by visual perception.

We investigate the formation of cohesive groups and the collective diffusion of colloidal spherocylinders with a motility driven by a simple visual perception model. For this, we perform Brownian dynamics simulations without hydrodynamic interactions. The visual perception is based on sight cones attached to the spherocylinders and perception functions quantifying the visual stimuli. If the perception function of a particle reaches a predefined threshold, an active component is added to its motion. We find that, in addition to the opening angle of the cone of sight, the aspect ratio of the particles plays an important role for the formation of cohesive groups. If the elongation of the particles is increased, the maximum angle for which the rods organize themselves into such groups decreases distinctly. After a system forms a cohesive group, it performs a diffusive motion, which can be quantified by an effective diffusion coefficient. For increasing aspect ratios, the spatial expansion of the cohesive groups and the effective diffusion coefficient of the collective motion increase, while the number of active group members decreases. We also find that a larger particle number, a smaller propulsion velocity of the group members, and a smaller threshold for the visual stimulus increase the maximum opening angle for which cohesive groups form. Based on our results, we expect anisotropic particles to be of great relevance for the adjustability of visual perception-dependent motility.

Constructing "Closed" and "Open" {Mn8} Clusters.

Use of the 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane ligand, LH3, in manganese chemistry affords access to two structurally related {Mn8} clusters: a “closed” {MnIII6MnII2} puckered square wheel of formula [Mn8L2(LH)O3(OH)2(MeO)2Br(imH)(H2O)3](Br)3 (1; imH = imidazole) and an “open” {MnIII8} rod of formula [MnΙΙΙ8L2O4(aibH)2(aib)2(MeO)6(MeOH)2](NO3)2 (2, aibH = 2-amino-isobutyric acid). In each case the triaza ligands, L/LH, direct the formation of {Mn3} triangles with their N atoms preferentially bonding to the Jahn–Teller axes of the MnIII ions. Subsequent self-assembly is dependent on the anion of the Mn salt and the identity of the organic coligand employed—the terminally bonded imidazole and the chelating/bridging amino acid. The {Mn3} triangles fold up on themselves in 1, forming a wheel. However, the syn, syn-bridging carboxylates in 2 prevent this from happening, instead directing the formation of a linear rod. Magnetic susceptibility and magnetization measurements reveal competing ferro- and antiferromagnetic interactions in both complexes, the exchange being somewhat weaker in 1 due to the presence of MnII ions.