Poor Compression Research Articles

1569: Could radiotherapy be avoided in poor prognosis spinal cord compression?

1569: Could radiotherapy be avoided in poor prognosis spinal cord compression?

Highly compressive aerogel-elastomer hybrid porous material with redistributed strain for high-sensitive soft pressure sensors

Owing to the good sensitivity and simple fabrication process, flexible piezoresistive pressure sensors based on aerogels shows great applications in soft robotics, bioelectronics and so on. However, the poor compressibility and stability of the aerogel is still challenging the development of aerogel based flexible piezoresistive pressure sensors, simultaneously, it is urgent to pave a way to enhance the sensitivity of these sensors. Here, for the first time, we propose a universal strategy to prepare aerogel skeleton-elastomer shell hybrid porous material with enhanced compressibility for high-sensitive and stable flexible pressure sensors. We found that the elastomer shell disperses the strain in the aerogel skeleton and enhances the compressibility of the aerogel, which improve the stability of the sensor (10000 cycles of compression). More importantly, there are elastomer micro-blocks formed in the hybrid material, these micro-blocks redistribute the strain in the material which contributes to the high sensitivity (10.25 kPa−1) of the sensors. Furthermore, the sensors are successful in monitoring both of the large joint bending and subtle skin vibration, as well as remote controlling toy car and artificial hand. This work provides an effective and universal strategy to enhance the sensitivity and stability of the aerogel based flexible pressure sensors and promotes their development towards practical applications.

Optimizing irbesartan spherical agglomerates through principal component analysis and experimental design

Background: This study explores the amalgamation of crystallization and agglomeration through spherical crystallization, aiming to develop the spherical crystals of Irbesartan with improved micromeritic properties. The main objective is to use spherical crystallization techniques to improve the micromeritic characteristics of Irbesartan, which has poor flow and compressibility because of its crystal habit. Methodology: A solvent change approach was utilized to synthesize spherical agglomerates of Irbesartan. Several system parameters, including the amount of bridging liquid, the rate of stirring, and the concentration of the polymer, were tuned to enhance the particle size distribution and mechanical qualities. SEM, GC, PXRD, DSC, and FTIR analyses characterised the spherical crystals. Result and Discussion: The study demonstrated that spherical crystallization significantly enhanced Irbesartan's micromeritic properties. The angle of repose of optimized agglomerates was reduced by around 52%, indicating improved considerably flowability of irbesartan. The sphericity of the crystals was validated by SEM examination (shape factor: 0.996), and the solvent levels were found to be within allowable bounds by GC analysis. PXRD data showed no polymorphism alterations, and DSC/FTIR analyses confirmed that the excipients and drug were compatible. Conclusion: This process provides a feasible alternative to classic granulation and agglomeration procedures, resulting in better flow, compressibility, and spherical crystals. It streamlines the Irbesartan formulation, improving efficiency and uniformity, reducing manufacturing costs, higher tablet consistency, and enhancing patient compliance.

A Retrospective Analysis of Polymer Selection Using Solvent Casting: Formulation and DoE Optimization of the Amorphous Solid Dispersion of Amoxicillin Trihydrate by a Spray Drying Method

Background. Amoxicillin trihydrate possesses poor solubility, compressibility, and flow behavior. Amorphous solid dispersion prepared by spray drying could solve all three problems at the same time. Objective. To prepare amorphous solid dispersion after screening of polymers by solvent casting method using a spray drying method. Methods. The solvent casting method was used to screen polymers, PVP/VA S-630, PVP K30, Soluplus, PEG 4000, HPMC AS, and HPMC HP55, in 1 : 1 and 2 : 3 ratios and followed by spray drying after polymer selection. Results. The dissolution performance of the formulation improved with time. The optimum feed rate and feed concentration were found to have an impact on the flow properties and particle size of spray-dried formulations, and they were selected as independent variables in a 32 full factorial statistical design. The ANOVA and regression analysis suggest that the developed regression model has a significant overall fit to the data and can explain a substantial proportion of the variability in the dissolution at 10 minutes. The optimized batch was selected based on the decisive factors of minimum and maximum values of response variables. Overall, the optimized batch demonstrated improved characteristics in terms of percentage yield (32.81%), dissolution at 10 min (49.70%), and angle of repose at 31.42°. Conclusion. This study provides valuable insights into optimizing formulation strategies for preserving the amorphous state of drugs and contributes to the development of stable pharmaceutical formulations.

Effect of Ground Nut Shell Powder on Soil Stabilization By IJISRT

Various varieties of soil may be found across the world. The engineering features of soil are the most significant consideration in any building development. Construction on expanding soil is the most essential difficulty that civil engineers encounter. The expansive soil has typically undesired engineering properties, such as poor shear strength, plasticity, and compressibility; it expands when wet and shrinks when dry. Its characteristics can be enhanced with appropriate stabilizing procedures. Black cotton covers around 15% of the soil in India. Crops produced on black cotton soil include pea nuts, cotton, wheat, jowar, linseed, tobacco, castor, sunflower, and millets. In comparison, the peanut industry generates millions of tons of garbage. Nowadays, a key issue is "How to benefit from the industrial waste product." Soil stabilization is performed in order to improve the engineering qualities of the soil. The rising expense of typical stabilizing chemicals, along with the need to economically utilize industrial and agricultural waste for positive engineering reasons, prompted an inquiry into the stabilizing potential of groundnut shell powder (GSP) in expansive soil. This study looks at how to improve the geotechnical characteristics of expansive soil by performing various tests such as specific gravity, atterberg limit, compaction test, and California bearing ratio test to determine the properties of the untreated soil sample and then adding 5%, 7%, and 9% ground nut shell powder by weight of soil. In this phase, only untreated soil testing are conducted. After receiving treated and untreated soil results, compare the untreated black cotton soil results to various percentages of ground nut shell powder results to determine the optimum amount of ground nut shell powder necessary to increase the stability of black cotton soil.

JPEG-compatible Joint Image Compression and Encryption Algorithm with File Size Preservation

Joint image compression and encryption algorithms are intensively investigated due to their powerful capability of simultaneous image data compression and sensitive information protection. Unfortunately, most of the existing algorithms suffered from either poor compression efficiency or weak encryption strength, making them vulnerable to cryptanalysis. To address these limitations, we propose a chaos-based JPEG-compatible joint image compression and encryption algorithm. We separate the luminance and chrominance coefficients to preserve file size and encrypt the discrete cosine transform (DCT) coefficients in parallel. The proposed inter-block DC encryption strategy achieves high encryption intensity based on the permutation-substitution structure. In addition, we apply both inter- and intra-block permutations to AC coefficients and strengthen the encryption using an inter-block substitution for non-zero AC coefficients. The results of security and performance analyses demonstrate that the proposed algorithm offers robust encryption of image data while maintaining compression efficiency for real-time transmission.

Karakterisasi Pembentukan Ko-kristal Tenoksikam-Asam Malat dan Evaluasi Kompresibilitas dan Tabletabilitasnya

Tenoxicam is a non-steroidal anti-inflammatory drug which has poor compressibility and compactibility. One way to change the compressibility and compactibility of a material is to use co-crystallization techniques The aim of this research is to characterize the formation of co-crystal between tenoxicam and malic acid and evaluate their compressibility and tabletability. Tenoxicam-malic acid co-crystal were prepared using the ultrasound-assisted solution co-crystallisation (USSC) method with the addition of ethanol solvent at the same molar ratio. The USSC result was characterized by polarization microscopy, powder X-ray diffraction, and thermal analysis methods. Evaluation of compressibility and tabletability (tensile strength and elactic recovery) was carried out on tenoxicam-malic acid co-crystal and intact tenoxicam. Characterization of the USSC result indicated the formation of tenoxicam-malic acid co-crystal, which were characterized by crystal habit, powder X-ray diffraction patterns, and DSC thermograms that were specific and different from intact tenoxicam and malic acid. Compressibility evaluation results show that the tenoxicam-malic acid co-crystal is in the good flow properties category, while the intact tenoxicam is in the poor flow properties category. The tensile strength of tenoxicam-malic acid co-crystal is higher than that of intact tenoxicam at the same compression strength (40 kg/cm2). Tenoxicam-malic acid co-crystal showed lower elastic recovery compared to intact tenoxicam. These results can be concluded that tenoxicam-malic acid co-crystals have been successfully prepared using the USSC method and have better compressibility and tabletability than intact tenoxicam.

Early Failure Detection for CO2 Reduction Electrolyzers Via in-Line Electrochemical Impedance Spectroscopy

The electrochemical CO2 reduction reaction (CO2RR) presents the opportunity to produce chemical feedstocks and fuels directly from CO2. Recent achievements in energy efficiency and current density are approaching the targets required for commercial viability; however, stability remains more than two orders of magnitude below the required 80,000 h. In CO2RR there is a challenge to distinguish the cause of failure among many possibilities. Failure can result from initial setup (e.g. over or under compression of the membrane and electrodes), gradual degradation of components (e.g. cathode and anode catalyst restructuring and dissolution), accumulation of products or byproducts (e.g. alcohols or salt accumulation), or immediate failures (e.g. a hole in the membrane or a short circuit). These failure modes must be addressed to reach the targeted stability needed for the wide-scale adoption of this technology. Early identification and mitigation of these failures would increase the electrolyzer lifetime and the commercial viability of CO2RR electrolyzers.Current techniques to characterize failures of the electrolyzer rely on post-mortem analysis of cell components. The analysis of individual components after operation may not accurately reflect their state in operando. There are techniques that are capable of analyzing the cell in operation (e.g. XAS, Raman, and TEM), but these typically require modified cell architectures and are operated at lower reaction rates. To effectively diagnose failure, the analysis technique should be applied to electrolyzers operating under realistic conditions.Here we implement an in-line real-time electrochemical impedance spectroscopy (EIS) technique to monitor CO2RR electrolyzers during operation. EIS is a non-destructive technique that can provide continuous information on the performance of specific components within the electrolyzer. We characterize common failure modes, such as poor compression, salt formation, catalyst degradation, and short circuits, and their identifying changes to the EIS response. We extract key electrochemical parameters from the EIS response and use them to develop a framework to identify and prevent the most common failure modes. Among other applications, this framework allowed for the detection of anode catalyst degradation 11 h before other indicators, such as cell voltage or product selectivity. This technique and framework can be applied to monitor CO2 electrolyzers as they are scaled and stacked.

Outstanding Synergy of Sensitivity and Linear Range Enabled by Multigradient Architectures.

Flexible pressure sensors are devices that mimic the sensory capabilities of natural human skin and enable robots to perceive external stimuli. One of the main challenges is maintaining high sensitivity over a broad linear pressure range due to poor structural compressibility. Here, we report a flexible pressure sensor with an ultrahigh sensitivity of 153.3 kPa-1 and linear response over an unprecedentedly broad pressure range from 0.0005 to 1300 kPa based on interdigital-shaped, multigradient architectures, featuring modulus, conductivity, and microstructure gradients. Such multigradient architectures and interdigital-shaped configurations enable effective stress transfer and conductivity regulation, evading the pressure sensitivity-linear range trade-off dilemma. Together with high pressure resolution, high frequency response, and good reproducibility over the ultrabroad linear range, proof-of-concept applications such as acoustic wave detection, high-resolution pressure measurement, and healthcare monitoring in diverse scenarios are demonstrated.

Twin-screw melt granulation for high-dose paracetamol tablets

Abstract Objectives In this study twin-screw melt granulation (TSMG) was used to produce sustained release formulations and improve the poor compressibility of paracetamol (PMOL). Methods By using various amounts of polyethylene glycol (PEG), a low melting point binder and ethyl cellulose (EC) as insoluble carrier, the formation of high content of PMOL granules occurred at low processing temperatures (55°C). Key findings X-ray diffraction and differential scanning calorimetry analysis showed the presence of partially crystalline PMOL in the extruded granules. Compressed caplet tablets comprising of TSMG granules presented sustained release profiles for 3-4 h depending on the EC concentration. The tablets showed excellent tabletability and low compaction forces were applied. Conclusions TSMG can be used for the processing of drugs with poor compressibility actives for the compression of high-dose tablets.

Understanding the static performance of composite helical springs with braided nested structures

Application of composite helical springs (CHSs) is constrained by their poor static compression performance. In this study, a novel composite helical spring with a braided nested structure (BNCHS) is proposed. The fiber volume fraction (Vf) of BNCHS with braided angle of 15° and 30° (BNCHS15° and BNCHS30°) only increases by 0.9% and 1.8% respectively comparing with that of unidirectional composite helical spring with Vf of 55% (UCHS55%). The compression experimental results show that the spring constant of BNCHS15° and BNCHS30° can reach 105.4% and 171.4% higher than that of UCHS55% respectively. The internal mechanism of significantly improving compression performance of BNCHS is revealed by using a meso model. Numerical result shows that the mises stress of BNCHS15° and BNCHS30° can be 2.43 and 3.14 times higher than that of UCHS55% respectively. Finally, the resilience and specific spring stiffness of BNCHS and steel are compared, highlighting the obvious advantage of static performance of BNCHS.

Bioinspired Engineering of Fillable Gradient Structure into Flexible Capacitive Pressure Sensor Toward Ultra-High Sensitivity and Wide Working Range.

Tactile sensing is required for electronic skin and intelligent robots to function properly. However, the dielectric layer's poor structural compressibility in conventional pressure sensors results in a limited pressure sensing range and low sensitivity. To solve this issue, a flexible pressure sensor with a crocodile-inspired fillable gradient structure is provided. The fillable gradient structure and grooves in the pressure sensor accommodate the deformed microstructure that permits the enhancement of the media layer compressibility via COMSOL finite element simulation and optimization. The pressure sensor exhibits a high sensitivity of up to 0.97kPa-1 (0-4kPa), a wide pressure detection range (7Pa-380kPa), and outstanding repeatability. The sensor can detect Morse code, robotic grabbing, and human motion monitoring. As a result, flexible sensors with a bionic fillable gradient structure pave the way for wearable devices and offer a novel method for achieving highly precise tactile perception.

Effect of Different Stabilizers on Spherical Agglomerates of Montelukast Sodium by Quasi Emulsion Solvent Diffusion (QESD)

Abstract: The present study was focused on the spherical crystallization of an asthmatic drug, Montelukast Sodium (MLS) using quasi emulsion solvent diffusion (QESD) technique in which distilled water was an external phase and the internal phase consisted of Ethanol which acts as good solvent and Ethyl acetate as a bridging liquid for recrystallization and agglomeration process. Apart from being poorly water soluble, MLS exhibits poor flow and compressibility. The spherical agglomeration was carried out in the presence of different stabilizers like acacia, PEG 4000, sodium lauryl sulphate, span 40 and tween 80. The prepared agglomerates were characterized in terms of production yield, drug content, solubility, in-vitro release profile, Xray diffraction (XRD), and Fourier transform infra red spectroscopy (FT-IR).The optimized spherical agglomerates exhibited excellent physicochemical and micromeritic properties, solubility and dissolution rate when compared with pure drug .The XRD also revealed a characteristic decrease in crystallinity. The dissolution studies demonstrated a marked increase in the dissolution rate. FTIR study reveals there are no chemical changes in prepared recrystallized agglomerates. The considerable improvement in the dissolution rate of MLS from optimized crystal formulation was attributed to the wetting effect of polymers, decreased drug crystallinity, altered surface morphology and micronization. If this process can be scaled-up to manufacturing level, this technology has the potential to provide the directly compressed spherical agglomerates with improving the physicochemical and micromeritic properties

Microparticulation of Levofloxacin HCl by Crystallo-co-agglomeration Technique

Particle engineering techniques have gained a unique place in the present pharma industry to improve physicochemical properties of the drugs. The aim of this research work was to formulate and evaluate directly compressible agglomerates of Levofloxacin HCl with a view to improve their micromeritic properties and thereby to reduce the cost of production. Fluoroquinolone anti-infective, is used to treat bacterial conjunctivitis, sinusitis, chronic bronchitis, community- acquired pneumonia and pneumonia caused by penicillin resistant strains of Streptococcus pneumonia. Some of the fluoroquinolone high dose’s exhibit poor compressibility and flow properties, hence may not be suitable candidate for direct compression process, but by applying the crystallo-co-agglomeration (CCA) technique, the attempt may be made to change the properties of these molecules to make them suitable candidates for direct compression. This investigation was aimed to utilize CCA process to develop spherical agglomerates of levofloxacin HCl in selected polymers in different ratio. The developed spherical agglomerates of levofloxacin HCl may exhibit improved micrometric and dissolution properties hence may be suitable for direct compression process. Results indicated that micromeritic, mechanical and compressional properties of the agglomerates were greatly influenced by nature and type of polymer incorporated. The mean release time, mean dissolution time, dissolution efficiency, Q30 and Q90 of the tablets prepared from agglomerates showed remarkable increase in CCA compared to tablets prepared by wet granulation. Observations also revealed that by varying the type and concentration of polymer, desired release rate can be obtained.

Case report: Intra arterial thrombolysis with iv line can save an acutely ischemic limb

Case report: Intra arterial thrombolysis with iv line can save an acutely ischemic limb

Large-scale manufacturing of soluble hemostatic spacer dressing with excellent mechanical and comfortable properties

Death from acute hemorrhage is a major life-threatening. Spacer fabrics-based composite dressings have been widely concerned because of their good hemostasis and protection in wound healing, but the poor liquid absorption and compression recovery properties hinder their utilization. Herein, we report a soluble hemostatic spacer dressing based on a braided yarn of PTFE (core yarn)/carboxymethylated viscose (shell yarn) as the skin contact layer, a wrapped yarn of nylon monofilament (core yarn)/Coolmax (shell yarn) as the spacer layer, and UHMWPE yarn as the waterproof layer for wound healing. Among these, carboxymethylated viscose can stop bleeding, while PTFE has low adhesion and ensures the structural integrity of the spacer fabric. Moreover, the nylon monofilament can endow the dressing with excellent comfortability, resilience, and fatigue resistance. Coolmax can absorb blood. The as-prepared spacer dressing shows excellent mechanical, comfortable, and hemostasis properties. F2 had a hemostasis time of 5.15 min, a low coagulation index of 7.96%, a hemolysis rate of 0.98%, and a blood absorption rate of 159.09%. This work presents an integrated molding method to achieve large-scale manufacturing of spacer dressing, which is expected to guide materials design for future innovations in biomedical applications.

A REVIEW OF PHARMACEUTICAL NANO-COCRYSTAL: A NOVEL STRATEGY TO IMPROVE THE CHEMICAL AND PHYSICAL PROPERTIES FOR POORLY WATER SOLUBLE DRUGS

Drugs are a crucial commercial good in our lifestyle because they help us stay healthy and treat illnesses. Poor solubility,permeability, bioavailability, dissolving rate, hygroscopicity, tablet ability, compressibility, and stability of medicines aremajor causes of medication failure during clinical development. To overcome the shortcomings of pharmaceuticals,several methods can be created including salt formation, Nano-formulations, co-solvency, complexation withcyclodextrins and surfactants, micronization, solid dispersions, coamorphous formulations, cocrystallization,nanococrystallization, etc.Nanococrystallization is the approach that has the best chance of enhancing the physical and chemical characteristics ofAPIs without altering their chemical composition. With the extra advantage of a carrier-free delivery route,nanococrystallization offers a flexible technique for saving poorly soluble medicines. In this review, we provide acomprehensive analysis of nanococrystals. In these we also compare the cocrystal with nano cocrystal along with theformulation methods, advantages and characterization techniques for nanococrystals.

A study on the effects of interfering with the conventional sequential protocol for chemical isolation and characterization of chitosan from biowaste of giant freshwater prawn Macrobrachium rosenbergii

Unless better measures are put in place to address the environmental and social impacts emanating from the huge waste generated from sea food processing industries; ‘tragedy of the commons’ is inevitable. Needless to re-emphasise the enormous contributions of aquaculture as the perfect substitute to capture fisheries which has been proven unsustainable. Be that as it may, the huge amount of bio-waste produced could be transformed into useful products such as chitin and chitosan with far reaching applications. Chitin and chitosan have been consistently processed from many sources following the traditional chemical sequence of Demineralization (DM), Deproteinization (DP), Decolouration (DC) and Deacetylation (DA). In this study, this method was re-ordered, resulting to 4 sequences of chemical processes. HCl, NaOH, ethanol (97%) and NaOH (50%) were used for DM, DP, DC and DA respectively. The results of this study showed that better chitin (23.99 ± 0.61%) and chitosan (15.17 ± 1.69%) yields were obtained from sequence four (SQ4) following the order of DC-DM-DP-DA. In addition, physicochemical properties such as DDA (80.67 ± 2.52%) and solubility (66.43 ± 2.61%) were significantly higher (p ≤ 0.05) in SQ4 thereby making the obtained product suitable for use as coagulant and flocculant in wastewater treatment. Results of FTIR, XRD and SEM of the study proved that the resultant product exhibited the characteristic nature of chitosan with porous and fibril nature. In the analysis of the physical properties of chitosan obtained from bio-waste of Macrobrachiumrosenbergii, the high Carr's index (CI) and low bulk as well as tapped densities were an indication that the chitosan produced in this study had poor flowability and compressibility, thereby making it unfit for application in pharmaceutical industries.

Bioinspired MXene‐Based Piezoresistive Sensor with Two‐stage Enhancement for Motion Capture

AbstractStructured piezoresistive membranes are compelling building blocks for wearable bioelectronics. However, the poor structural compressibility of conventional microstructures leads to rapid saturation of detection range and low sensitivity of piezoresistive devices, limiting their commercial applications. Herein, a bioinspired MXene‐based piezoresistive device is reported, which can effectively boost the sensitivity while broadening the response range by architecting intermittent villus‐like microstructures. Benefitting from the two‐stage amplification effect of this intermittent architecture, the developed MXene‐based piezoresistive bioelectronics exhibit a high sensitivity of 461 kPa−1 and a broad pressure detection range of up to 311 kPa, which are about 20 and 5 times higher than that of the homogeneous microstructures, respectively. Cooperating with the deep‐learning algorithm, the designed bioelectronics can effectively capture complex human movements and precisely identify human motion with a high recognition accuracy of 99%. Evidently, this intermittent architecture of biomimetic strategy may pave a promising avenue to overcome the limitation of rapid saturation and low sensitivity in piezoresistive bioelectronics, and provide a general way to promote its large‐scale applications.

Enhancing tabletability of high-dose tablets by tailoring properties of spray-dried insulin particles

The oral delivery of proteins and peptides provides an attractive dosing option due to its high patient compliance. However, as oral formulations of such macromolecules require the addition of typically poorly compactable permeation enhancers, the compression behaviour in tableting processes can become challenging. In this study, we show that poor compression behaviour can be overcome by tailoring the properties of peptide or protein particles, especially in high-dose tablet formulations. Spray-dried particles with varying particle size and morphology were produced and characterized. The particles were then evaluated for tabletability in well- and poorly tabletable formulations. Tabletability was found to be enhanced most with small and non-hollow spray-dried insulin particles in both formulations. The enhancement was more pronounced in the poorly tabletable formulation than in the well-tabletable one. Thus, the API particle properties play a key role, when evaluating manufacturability of poorly tabletable formulations.