The envelope density of the roll-compacted ribbon is a widely accepted physical property that serves as a criterion for the transferability of dry granulation processes. Existing methods of obtaining ...ribbon density data have drawbacks in their reliability and availability at production facilities. A novel method is proposed in this paper and the performance thereof is compared to other established techniques. A pilot study was conducted on several roller compactors to prepare various batches of ribbons under different process parameters using model and real formulations from the industry. The presented method measures the envelope volume of roll-compacted ribbons by solid volume displacement of glass microspheres. The solid displacement method for measuring envelope density is as precise as mercury porosimetry, provided that the ribbon quality is adequate, even in the presence of minor structural failures, it is nondestructive allowing sample reuse, and it is scalable to larger ribbon sizes.
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•A novel method of measuring envelope density of compacted solids is proposed.•Method utilize solid volume displacement of glass microspheres.•Method performance validated on samples of pharmaceutical roll compacted ribbons.•Solid displacement method is as precise as mercury porosimetry, even in the presence of minor structural failures.
Ribbon Synapses and Retinal Disease: Review Frederick, Courtney E; Zenisek, David
International journal of molecular sciences,
03/2023, Volume:
24, Issue:
6
Journal Article
Peer reviewed
Open access
Synaptic ribbons are presynaptic protein complexes that are believed to be important for the transmission of sensory information in the visual system. Ribbons are selectively associated with those ...synapses where graded changes in membrane potential drive continuous neurotransmitter release. Defective synaptic transmission can arise as a result of the mutagenesis of a single ribbon component. Visual diseases that stem from malfunctions in the presynaptic molecular machinery of ribbon synapses in the retina are rare. In this review, we provide an overview of synaptopathies that give rise to retinal malfunction and our present understanding of the mechanisms that underlie their pathogenesis and discuss muscular dystrophies that exhibit ribbon synapse involvement in the pathology.
In the present paper, the thermal stability of the nanotextures formed from the same-sized weft and warp graphene ribbons were examined by molecular dynamics simulations. It was found that graphene ...ribbons existed in a nanotexture had relative sliding, rotating and bending movements at room temperature. Due to asynchronous motion, the initially parallel ribbons (either weft or warp ribbons) became curved and a part of neighboring ribbons were found to be attached together, consequently, the obtained nanotexture became wrinkled and lost its stability. Moreover, the wrinkle direction was aligned with one of the diagonals of the square nanotexture. It was noticed that nanotextures formed from zigzag ribbons were thermally shrunk at higher temperatures, whereas, the nanotextures obtained from armchair ribbons manifested thermal expansion properties. Furthermore, nanotextures formed from ribbons wider than 0.7 nm were thermally stability at room temperature.
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•A new two-dimensional material, i.e., nanotexture, fabricated by weft and warp ribbons is proposed.•At relative high temperature, nanotexture composed from narrow ribbons wrinkles in thermal bath.•Wrinkle goes along a diagonal of the square nanotexture with the same-sized weft and warp ribbons.•Wrinkle is caused by asynchronous motion of neighbor ribbons in relaxation.
Air pollution has threatened public health and environment especially in particulate matter (PM) diffusion. Due to the efficient removal, electrospun nanofiber membranes with multi-hierarchical ...structure have attracted attention for advanced air filtration. However, nanofibers fabricated by traditional electrospinning confront the challenge encountered in consuming numerous organic solvent which cause secondary pollution to the environment. In this study, based on green one-step electrospinning, eco-friendly curved-ribbon nanofiber membrane with multi-hierarchical structure was proposed for efficient, breathable and sustainable air filtration. Compared with common stick-like fiber, the typical curved-ribbon fiber exhibited excellent removal of PM depending on the unique morphological interception and polar adsorption. In addition, benefiting from loose and elastic structure, nanofiber membrane with the typical curved-ribbon feature possessed remarkable air permeability and stretch ability. This study provides a green and convenient design to the production of an eco-friendly, breathable and high-performance air filter with multi-hierarchical structure, which is prospective to substitute the traditional filters for accommodating to the sustainable development in the future.
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•The typical curved-ribbon nanofiber membrane was fabricated.•The multi-hierarchical structure for improving physical interception was proposed.•The green and simple method were carried out during the preparation process.•The curved-ribbon nanofiber membrane exhibited excellent filtration performance.
This study presents the synthesis of nanocomposite namely n-type CeO2/p-type CuS heterojunctions as adsorbent/photocatalysts by electrospinning and hydrothermal methods with a low band gap. ...Photo-degradation of MB at various time under visible light radiation (LED) for calculating Langmuir–Hinshelwood (L–H) kinetics used. The influence of the operational parameters such as are pH, concentration of MB, amount of photocatalyst, and irradiation time investigated.
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Composite of n-type CeO2/p-type CuS heterojunctions as adsorbent/photocatalysts were successfully synthesized based on electrospinning technique, calcination and hydrothermal methods following growth of CuS nanostructures on the primary CeO2 nanofibers, while laterally were characterized by FE-SEM, EDS, XRD, DRS and FT-IR. Present composite in aqueous solutions was applied for methylene blue (MB) degradation was investigated under visible light radiation (LED). DRS analysis illustrates that CeO2/CuS n–p heterojunction exhibited enhanced absorption in the visible region with band gap of 2.55. Under optimal conditions (3.0 mg L−1 MB, 1 g L−1 of CeO2/CuS dosage and 40 min irritation time at pH of 6.0) lead to 89.80% photocatalytic decomposition of MB. The CeO2/CuS composite nanofiber as photocatalyst exhibited enhanced visible-light absorption and reduced charge recombination, as compared to bare CeO2 ribbon-like nanofibers, due to the interfacial charge transfer effect among the CuS species and CeO2. The first-order kinetics based on Langmuir–Hinshelwood (L–H) model was able for effective fitting empirical data, while its rate constant (kobs), L–H rate constants (kr) and L–H adsorption constants (KA) were 0.0625 min−1, 0.157 mg min−1 L and 0.24 L mg−1 by CeO2/CuS in optimum condition. The reusability of CeO2/CuS composite is relatively undesirable in view of the recycling of photocatalysts.
Fe-based nanocrystalline ribbon is an alternative to the ferrite for high-frequency magnetic cores due to its low hysteresis loss and high magnetic saturation. The drawback of the Fe-based ...nanocrystalline ribbon is its high conductivity. Crushing the homogenous ribbon to restructure a nanocrystalline flake ribbon (NFR) can reduce the conductivity while maintaining other superior magnetic properties of the non-crushed nanocrystalline ribbon. So far, several previous works have proven that the NFR can replace the ferrite in the dual active bridge and wireless power transfer system. However, seldom of these works mention the detailed mechanism of the NFR. In this paper, the structure and manufacturing process of the NFR are introduced. the effect of the relative permeability and the crushing pattern on the magnetic properties of NFR has been quantitatively reported. A dual-permeability core formed by two types of NFR has been demonstrated for an inductor. Comparison has been made to inductors using the ferrite core (N27, N87, DMR44) in a similar size. Experiment results show that the dual-permeability NFR core has a lower core loss and higher magnetic saturation than the ferrite counterparts at frequencies from 100 to 300 kHz.
We fabricated the amorphous Ho0.2Tm0.2Gd0.2Co0.2Al0.2 ribbon by melt-spun method and systematically investigated its glass forming ability (GFA) and magnetic properties, especially of the magnetic ...phase transition (MPT) and magneto-caloric (MC) effect. The melt-spun Ho0.2Tm0.2Gd0.2Co0.2Al0.2 ribbon is found to exhibit a fully amorphous structure and good GFA. The amorphous Ho0.2Tm0.2Gd0.2Co0.2Al0.2 ribbon undergoes a second order type MPT around 32.6 K from ferromagnetic to paramagnetic state. Large reversible low temperature MC effect and good MC performances in the amorphous Ho0.2Tm0.2Gd0.2Co0.2Al0.2 ribbon were realized which was identified by the parameters of magnetic entropy change, temperature-averaged entropy change, and refrigerant capacity. These parameters are are at similarly high level with recently reported low temperature MC materials, making the amorphous Ho0.2Tm0.2Gd0.2Co0.2Al0.2 ribbon also attractive for magnetic cooling.
The magnetic properties and magnetic entropy change of amorphousized Tm60Co20Ni20 ribbon were systematically studied. The results indicate that the Tm60Co20Ni20 amorphous ribbon reveals a second ...order magnetic transition (paramagnetic to ferromagnetic state) based on the Arrott plots and rescaled magnetic entropy change curves. A large magnetic entropy change is achieved around its Curie temperature of TC ∼6.7 K. Under the magnetic field change (ΔΗ) of 0–5 T, the maximum values of magnetic entropy change (−ΔSMmax) and relative cooling power (RCP) are 17.1 J/kg K and 273 J/kg, respectively. In particular, under a relative low ΔΗ of 0–2 T, a large magnetic entropy change of 11.8 J/kg K reaches, making it attractive in the field of low-temperature magnetic refrigeration.
•The magnetic properties and magnetocaloric effect (MCE) of amorphousized Tm60Co20Ni20 ribbon were systematically studied.•A large reversible MCE, especially under a low magnetic field change of 0–2 T was observed in Tm60Co20Ni20.•The origin of MCE and its potential application in amorphousized Tm60Co20Ni20 ribbon were discussed.
Hearing is an extremely delicate sense that is particularly vulnerable to insults from environment, including drugs and noise. Unsurprisingly, mice of different genetic backgrounds show different ...susceptibility to hearing loss. In particular, CBA/CaJ (CBA) mice maintain relatively stable hearing over age while C57BL/6J (B6) mice show a steady decline of hearing, making them a popular model for early onset hearing loss. To reveal possible underlying mechanisms, we examined cellular differences in the cochlea of these two mouse strains. Although the ABR threshold and Wave I latency are comparable between them, B6 mice have a smaller Wave I amplitude. This difference is probably due to fewer spiral ganglion neurons found in B6 mice, as the number of ribbon synapses per inner hair cell (IHC) is comparable between the two mouse strains. Next, we compared the outer hair cell (OHC) function and we found OHCs from B6 mice are larger in size but the prestin density is similar among them, consistent with the finding that they share similar hearing thresholds. Lastly, we examined the IHC function and we found IHCs from B6 mice have a larger Ca
current, release more synaptic vesicles and recycle synaptic vesicles more quickly. Taken together, our results suggest that excessive exocytosis from IHCs in B6 mice may raise the probability of glutamate toxicity in ribbon synapses, which could accumulate over time and eventually lead to early onset hearing loss.
Roller compaction is a widely used continuous dry granulation process in the food and pharmaceutical industries. The flow and distribution of the powder across the rollers in the compaction area ...plays a crucial role in determining the quality of the final product. Non-uniform powder flow and distribution across the rollers can lead to variations in quality across the ribbon, resulting in uneven qualities in the granules. Hence, it is essential to enhance the powder flow and distribution across the rollers in the compaction area. Besides that, insufficient compaction stress on both sides of the roller edges can also contribute to presence of uncompacted fines during compaction process.
This research aims to systematically study a whole range of customized guiders design (T-1 until T-14) that improves powder flow and distribution across the rollers and reduces the percentage of fines in the compaction zone. The 3D printed customized guiders with different grade (1 mm until 14 mm) were applied in roller compactor with horizontal feeding system to control the amount of powder passing through the roller width by guiding more powder to the sides between the rollers and less powder to the centre. The effectiveness of the design was validated by examining crystalline and spray dry lactose powders with varying flowabilities using online thermal imaging. The results demonstrate a significant trend, indicating improved uniformity of powder flow and distribution across the rollers and reduced production of fines. These findings have the potential to contribute to long-term sustainability and resource conservation in industrial applications by reducing the need for material recycling and lowering energy consumption in continuous processes.
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•A systematic study of 14 customized guiders on powder distribution in roller compaction was conducted using PAT.•Crystalline and spray-dried lactose with varying flowability were utilized.•Powder with low flowability shows non-uniform distribution during compaction.•Customized guiders improved temperature distribution, uniformity, and reduced fines in low-flowability lactose powder.
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