Angle Measurements Research Articles

Scoliosis Progression after Lung Transplantation: Scoliosis after lung transplantation.

Scoliosis is a potential postoperative complication of various pediatric cardiothoracic conditions. To investigate the incidence of scoliosis in pediatric lung transplant patients and explore the factors associated with its development. Retrospective observational study PATIENT SAMPLE: 330 consecutive lung transplant recipients at a single institution between April 2002 and June 2022. The incidence of scoliosis METHODS: After excluding 45 patients with <1 year of follow-up, 285 patients were analyzed: 43 pediatric (≤17 years) and 242 adult (>18 years) patients. Data on baseline demographics, Cobb angle measurements pre- and post-transplant, and lung volumes at 1-year post-transplant in pediatric patients were collected. The prevalence of scoliosis was compared between pediatric and adult patients. Additionally, the impact of lung volume differences (right minus left) on scoliosis progression was assessed. Pediatric (n=43) and adult (n=242) patients had a mean age of 10.3 and 44.9 years, respectively. Scoliosis was significantly more prevalent in pediatric patients, with 30.2% having a Cobb angle >10° and 13.9% having a Cobb angle >20°, compared to 11.5% and 1.6% in adults, respectively. Pediatric patients with Cobb angles >20° exhibited significant lung volume differences 1-year post-transplant. Lung volume disparities increased the risk of scoliosis progression, particularly in patients with unilateral lung collapse. Pediatric lung transplant recipients have a higher incidence of significant scoliosis than adult recipients. Post-transplant lung volume disparities, especially in cases of unilateral lung collapse, may contribute to scoliosis progression. Routine spinal assessments are necessary for managing scoliosis in pediatric lung transplant patients to prevent curvature progression and ensure long-term musculoskeletal health.

Enhancing the biological characteristics of aminolysis surface-modified 3D printed nanocomposite polycaprolactone/nanohydroxyapatite scaffold via gelatin biomacromolecule immobilization: An in vitro and in vivo study.

The surface characteristics of scaffolds utilized in bone tissue engineering profoundly influence subsequent cellular response. This study investigated the efficacy of applying a gelatin coat to the surface of aminolysis surface-modified scaffolds fabricated through 3D printing with a polycaprolactone/hydroxyapatite nanocomposite, employing the hot-melt extrusion FDM technique. Initially, aminolysis surface modification using hexamethylenediamine enhanced surface hydrophilicity by introducing amine functional groups. Subsequently, gelatin solutions were applied to the scaffolds, and crosslinking with EDC/NHS was performed to increase coating strength. Contact angle measurements revealed a significantly increased surface hydrophilicity post-aminolysis. Aminolysis facilitated uniform gelatin coating formation and distribution. Subsequently, crosslinking enhanced coating durability. The addition of gelatin coating resulted in a notable 20 % increase in scaffold mechanical strength and more than 50 % rise in Young's modulus and exhibited enhancement of biodegradability and bioactivity. Gelatin coated scaffolds also demonstrated improved cell viability and adhesion and over two times higher expression of OPN and ALP genes, suggesting improved biological properties. In addition, in vivo bone formation studies verified the biological enhancement of scaffolds. Utilizing an immobilized crosslinked gelatin biomacromolecule coating effectively enhanced the biological characteristics of 3D printed scaffolds and their potential applications as bone tissue engineering scaffolds.

Development of a superhydrophobic and superoleophilic halloysite nanotube/phenyltriethoxysilane-coated melamine sponge sorbent material with high performance in supercritical CO2 atmosphere for the selective and effective oil spill cleanup and oil-water separation.

In this study, activated halloysite nanotube (HNT) and phenyltriethoxysilane (PTES) were utilized for the first time to fabricate modified HNT materials and coat them onto melamine sponge (MS) substrate in the supercritical carbon dioxide (scCO2) atmosphere. The successful coating of MS substrate was confirmed using SEM, EDS, XPS, and contact angle measurements. The drainage technique applied in the CO2 medium achieved the uniform coating of both the inner and outer surfaces of the MS. Water and oil contact angles of the fabricated sorbent material (MS-PTES) were measured as 167.1° and 0°, respectively. MS-PTES sorbent having superhydrophobic and superoleophilic properties demonstrated sorption capacities ranging from 47.6g/g to 132.2g/g for 13 different pollutants, including various petroleum products, oils, and organic solvents. Moreover, the MS-PTES sorbent material showed outstanding separation efficiency (99.99%) for the diesel-water mixture using a continuous separation process. It also displayed high selectivity for oil and organic solvent pollutants under acidic, saline, and alkaline conditions, along with excellent reusability, chemical stability, robustness, and mechanical flexibility. MS sorbent material coated with HNT-modified PTES nanoparticles, produced in the scCO2 atmosphere using the drainage technique, represents a promising solution for the removal of petroleum derivatives, oils, and organic solvents from water.

Design of the magnetic circuit compensation type of large angle measurement of RVDT

Design of the magnetic circuit compensation type of large angle measurement of RVDT

Optimization of PVA/ alkali treated ramie fiber-based composite film for green packaging application using response surface methodology approach

Natural fiber-reinforced composites have gained significant attention as eco-friendly alternatives in sustainable packaging due to their biodegradability, renewability, and low environmental impact. This study aimed to produce an optimum composite film by combining PVA with alkali-treated-ramie fiber using a central composite design (CCD). This research investigates the effects of two independent factors, PVA (60-100 wt%) and alkali-treated ramie fiber (0-40 wt%), on three dependent variables: tensile strength, elongation at break (%), and contact angle of the composite film. Response surface methodology (RSM) determined that the optimal film composition for packaging application is 80 wt% PVA and 20 wt% alkali treated-ramie fiber. This combination resulted in a tensile strength of 46.03 MPa, an elongation limit of 251.4 %, and a contact angle of 66.75°. The film, which was produced utilizing the optimal outcomes, was then subjected to several characterization methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, contact angle measurement, water vapor transmission rate analysis, and FTIR spectroscopy. This outcome exemplified the optimal use of processed Ramie fiber in a polymer matrix for the purpose of eco-friendly packaging.

Preparation and characterization of mangiferin-loaded polylactic acid nanofiber mat with antioxidant and anti-browning properties for the development of food packaging products

In this study, antioxidant nanofiber-based food packaging material composed of polylactic acid (PLA) and mangiferin (MG) was produced to reduce food spoilage. To this end, MG was extracted from Mangifera indica and chemically characterized. In vitro assays for scavenging several radical ions showed excellent antioxidant properties of MG. Thereafter, MG was blended with PLA to form nanofibers (PLA-MG) using electrospinning. The Field Emission-Scanning Electron Microscopy (FE-SEM) images of the prepared nanofibers displayed defect-free homogeneous morphology with an average fiber diameter of 176.89 ± 61.97 nm. Fabricated nanofibers were physico-chemically characterized. From chromatography, mangiferin content in the PLA-MG fiber was found to be 40.55 ± 3.7 μg/mg of fiber. Contact angle measurements of the fabricated nanofibers showed the hydrophobic nature of PLA-MG nanofibers. PLA-MG nanofibers demonstrated a significantly higher antioxidant activity compared to PLA nanofibers (****p < 0.0001), as evidenced by their superior performance in DPPH, ABTS, and FRAP assays. Specifically, PLA-MG nanofibers exhibited 3676 ± 3.46 mg/100 g vitamin C equivalents in antioxidant activity (VCEAC) and 1866 ± 2.12 VCEAC in ABTS and DPPH radical scavenging assays respectively. Further, apples wrapped with PLA-MG nanofibers showed that the browning of the fruit decreased when compared with controls. The MTT assay and live-dead assay indicated that the fabricated nanofibers were cytocompatible with L929 fibroblasts. The results showed that the fabricated PLA-MG nanofibers can be an effective non-toxic food packaging material to increase the shelf-life of the food. Finally, PLA-MG nanofiber-coated food container production was demonstrated to be commercialized for the effective transportation of food.

Predicting bursal-side supraspinatus tendon tears with the acromioclavicular angle

BackgroundBursal-side supraspinatus tendon tears are a common form of rotator cuff injury, often associated with acromial impingement and other extrinsic factors. Existing anatomical parameters, such as the lateral acromion angle, acromial index, and critical shoulder angle, have been studied in relation to rotator cuff tears; however, reliable indicators specific to the risk of bursal-side supraspinatus tears remain lacking. The acromioclavicular (AC) angle, which reflects the angular relationship between the acromion and clavicle, may offer a new predictive marker for this specific pathology. MethodsIn this retrospective case-control study, patients presenting with shoulder pain between January 2016 and February 2020 were reviewed. Group 1 included patients with isolated bursal-side supraspinatus tendon tears confirmed by arthroscopy, while Group 2 consisted of age- and gender-matched controls without rotator cuff pathology. The AC angle was measured using both X-ray and MRI. Diagnostic performance was assessed through Receiver Operating Characteristic (ROC) curve analysis, identifying the optimal cut-point with Youden's index. Reliability was measured using the Intraclass Correlation Coefficient (ICC) for both intra- and inter-rater reliability. ResultsThe ROC analysis determined an optimal AC angle cut-point of ≤160°. X-ray measurements showed moderate diagnostic value (AUC 0.60, sensitivity 67.2 %, specificity 51.7 %), while MRI measurements demonstrated good diagnostic performance (AUC 0.79, sensitivity 84.5 %, specificity 70.7 %). X-ray yielded high sensitivity but low specificity, suggesting its utility as an initial screening tool, whereas MRI provided improved diagnostic accuracy. Reliability assessments indicated high intra- and inter-rater reliability for AC angle measurements across both imaging modalities (ICC >0.80). ConclusionThe AC angle, particularly when measured on MRI, may serve as a valuable diagnostic marker for identifying isolated bursal-side supraspinatus tendon tears. While X-ray can be utilized as an accessible screening tool, combining it with clinical assessments and MRI is recommended for greater diagnostic precision. Further multi-center, prospective studies are warranted to confirm the clinical utility of the AC angle in predicting rotator cuff pathology.

Micropatterned CuS@PDMS films with anti-adhesive property for photothermal sterilization

This study presents the development of micropatterned polydimethylsiloxane (PDMS) films with hollow CuS NPs (p-CuS@PDMS) designed for both anti-adhesive and photothermal sterilization applications. Hollow CuS nanoparticles (NPs) synthesized via the Kirkendall effect were incorporated into PDMS films to enhance the photothermal conversion. Micropatterning, achieved through a yogurt lid templating method, increased surface roughness and hydrophobicity and significantly reduced bacterial adhesion. The improved anti-adhesive properties were demonstrated by water contact angle measurements, which showed an increase of 24° from 103° to 127° for the micropatterned p-CuS@PDMS films. Under near-infrared (NIR) irradiation, the p-CuS@PDMS films achieved a temperature increase of 91 °C with a photothermal conversion efficiency of 73 %, which is much higher than the 61 °C achieved by plain PDMS. The presence of CuS NPs in the PDMS matrix improved the bacterial inactivation rates, with p-CuS@PDMS achieving a 99 % bacterial kill rate after 90 s of irradiation. Although the anti-adhesive properties were influenced more by micropatterning, the combination of CuS and micropatterning provided a synergistic effect. These results demonstrate the potential of p-CuS@PDMS films for applications in healthcare and packaging, where effective sterilization and bacterial resistance are critical.

DNA crossover flexibilities upon discrete spacers revealed by single-molecule FRET.

In this study, we utilized the origami technique to integrate various types of spacers into the double-stranded crossover and examined their flexibilities using single-molecule fluorescence resonance energy transfer (smFRET). We discovered that for the traditional Holliday Junction connection with zero-base spacers, the inter-structural angle measures 58.7 degrees, which aligns well with previous crystallographic research. When introducing non-complementary double-stranded spacers as a free leash, we observed that longer spacers resulted in a more relaxed connection. In contrast, when using complementary segments, the two origami structures rotated as the number of base pairs increased, reflecting the structural characteristics of the B-duplex. Our findings indicate that a stable intramolecular duplex requires a minimum of 5 base pairs. Overall, our results highlight the potential for re-engineering crossovers and designing materials that can change volume with shrink-swell capabilities, as well as applications in torque sensing using short DNA duplexes.

Synergistic effect and mechanism of ferric ion modified citric acid depressant in the flotation separation of scheelite from cassiterite

Scheelite and cassiterite often coexist in skarn deposits, which are prone to excessive crushing during dissociation, and gravity separation faces a challenge. However, research on flotation separation is limited. This study aimed to investigate the selective depression behavior and depression mechanism of a combined depressant containing ferric chloride and citric acid on cassiterite to successfully achieve the flotation separation of scheelite and cassiterite. Experimental studies on single minerals and artificially mixed minerals indicated that the individual ferric chloride or citric acid exhibited weak depressive abilities and poor selectivity toward cassiterite. However, a combination of ferric chloride and citric acid in a mass ratio of 3:7 achieved better separation results. At a pH of 8, with a concentration of 1 × 10–3 mol/L mixed depressant, and a sodium oleate concentration of 5 × 10–5 mol/L, scheelite and cassiterite exhibited recovery of 73.35 % and 19.98 %, with grades of 61.76 % and 16.18 %, respectively. Fourier–transform infrared spectroscopy and X–ray photoelectron spectroscopy analyses revealed that the mixed depressant strongly chemically adsorbed on the cassiterite surface, forming FeOOH at ferric species sites. Contact angle measurements indicated a significant reduction in surface hydrophobicity of the cassiterite surface due to mixed depressant components. Atomic force microscopy imaging analysis elucidated the adsorption morphology of the mixed depressant depressive component FeOOH on the cassiterite surface in both 2D and 3D imaging, indicating abundant high–intensity reagent peak adsorption. Therefore, the mixed depressant enhanced the selectivity of the depressant, facilitating the effective separation of scheelite and cassiterite.

Management of Congenital Scoliosis Presented to Department of Orthopedic &amp; Spine HMC: A Single Center Experience

Objective: To evaluate the impact of congenital scoliosis on spinal curvature severity and quality of life in patients treated at a single center in Pakistan, with a focus on demographic distribution, Cobb angle, and quality of life outcomes. Methodology: A retrospective cohort study was conducted from June 2013 to June 2023 at the Orthopedics and Spine Department, Hayatabad Medical Complex, Peshawar. The study included 100 patients aged 1 to 30 years diagnosed with congenital scoliosis. Data on demographics, Cobb angle measurements, and quality of life (using the SRS-22 questionnaire) were collected. Statistical analyses, including t-tests and chi-square tests, were performed to examine associations between gender, Cobb angle, and quality of life, with significance set at p &lt; 0.05. Results: The mean age of participants was 15.2 years (SD = 8.4), with an even gender distribution (52% male). The average Cobb angle was 49.7 degrees (SD = 18.6), indicating moderate to severe scoliosis, with no significant difference between genders (mean Cobb angle: males = 51.2°, females = 48.1°; p = 0.26). Quality of life scores averaged 3.7 (SD = 0.9), and a moderate negative correlation was found between Cobb angle and quality of life score (r = -0.35), suggesting that more severe curvature is associated with lower quality of life. A chi-square test also indicated no significant association between gender and scoliosis severity (p = 0.99). Conclusion: This study emphasizes the impact of congenital scoliosis on quality of life, with severity of spinal curvature correlating with reduced well-being. The findings highlight the need for early diagnosis and targeted intervention to optimize outcomes. This foundational data contributes to the understanding and management of congenital scoliosis in similar healthcare settings.

Influence of silver nanoparticles on the surface characteristics and electrical properties of polypyrrole/PET polymeric composite films for electronic devices

The motivation behind this study is to fabricate novel nanocomposite materials with stronger dielectric characteristics to be applied in electronic devices. The chemical oxidative polymerization technique was employed to fabricate the PET/(PPy-Ag) polymer composite films. These films consist of silver nanoparticles (AgNPs) and polypyrrole (PPy), and the blend (PPy-Ag) is then deposited on the polyethylene terephthalate (PET) substrate. The choice of method depends on the desired application, the properties of the polymer and the level of nanoparticle dispersion required. The characterization methods, Fourier-transform-infrared spectroscopy (FTIR) and energy dispersive X-ray (EDX) were utilized in this study. The EDX data show that the PET/(PPy-Ag) is successfully fabricated with elements C, N, O and Ag, with weight ratios of 15.76%, 8.92%, 65.88% and 9.44%, respectively. The influence of (PPy-Ag) on the conductivity and surface wettability of PET was evaluated. The surface-free energy and adhesion work were determined using contact angle measurements. The surface-free energy increased from 41.64 to 60.24[Formula: see text]mJ/m2 and the water adhesion work increased from 98.78[Formula: see text]mJ/m2 for PET/(PPy-Ag)-1 to 121.01[Formula: see text]mJ/m2 for PET/(PPy-Ag). Moreover, the conductivity enhanced from [Formula: see text][Formula: see text]S.cm[Formula: see text] for PET to [Formula: see text][Formula: see text]S.cm[Formula: see text] for (PPy-Ag)/PET. By modifying the properties of the composite PET/(PPy-Ag), the results demonstrated that the fabricated composite can be used as an electronic and industrial device.

Surface Hydrophilic Modification of Polypropylene by Nanosecond Pulsed Ar/O2 Dielectric Barrier Discharge.

Polypropylene (PP) membranes have found diverse applications, such as in wastewater treatment, lithium-ion batteries, and pharmaceuticals, due to their low cost, excellent mechanical properties, thermal stability, and chemical resistance. However, the intrinsic hydrophobicity of PP materials leads to membrane fouling and filtration flux reduction, which greatly hinders the applications of PP membranes. Dielectric barrier discharge (DBD) is an effective technique for surface modification of materials because it generates a large area of low-temperature plasma at atmospheric pressure. In this study, O2 was added to nanosecond pulsed Ar DBD to increase its reactivity. Electrical and optical diagnostic techniques were used to study the discharge characteristics of the DBD at varying O2 contents. The uniformity of the discharge was quantitatively analyzed using the observed discharge images. Water contact angle measurements were used to assess the surface hydrophilicity of polypropylene. The surface morphology and chemical composition of the PP materials before and after treatment were analyzed using field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The results show that the moderate addition of O2 enhances surface hydrophilicity and the uniformity of the modification. By increasing the O2 addition from 0% to 0.1%, the average power increased from 4.19 W to 5.79 W, and the energy efficiency increased from 17.78% to 21.51%. The water contact angle of the DBD-treated PP showed a tendency to decrease and then increase with increasing O2 content, with the optimum O2 addition determined to be 0.1%. Under this condition, the water contact angle of the PP surface decreased by 31.88°, which is 52.31% lower than the untreated surface. O2 increases the number of oxygen-containing polar groups (-OH, C=O, and O-C=O) on the surface of the material, and deepens and densifies the grooves on the surface of the PP material, resulting in an increase in the hydrophilicity of the PP surface.

External Validity of the Novel Surrogate Measures for Occipitocervical Alignment

Background: Occipitocervical fusion (OCF) is a rare and often challenging surgical procedure. Several methods have been introduced to obtain the best measures for occipitocervical alignment. The mandible-C2 angle was first introduced in 2020. In this study, we aimed to evaluate the out-of-sample validity of these measures. Methods: We retrospectively studied 274 lateral cervical radiographs of patients aged 1 to 87 years with no cervical pathology evident on X-ray. A board-certified radiologist and a second-year radiology resident performed the measurements on five specific angles as suggested by Bellabarba. The five angles measured consisted of: 1) anterior C2 body/anterior mandible angle (AB/AM), 2) anterior C2 body/posterior mandible angle (AB/PM), 3) posterior C2 body/anterior mandible angle (PB/AM), 4) posterior C2 body/posterior mandible angle (PB/PM), and 5) occipito-C2 angle (OC2A). Results: Inter-rater correlation data were calculated for single and average measures. The inter-rater agreement for individual angle measures of O-C2A, AB/AM, AB/PM, PB/AM, and PB/PM were 0.49, 0.11, 0.25, 0.33, and 0.49, respectively. The intraclass correlation coefficient (ICC) for average measures of O-C2A, AB/AM, AB/PM, PB/AM, and PB/PM were 0.66, 0.20, 0.40, 0.50, and 0.66, respectively. Conclusion: Our study did not find statistically significant evidence to confirm that these angles were dependable indicators of occipitocervical alignment, except for the PB/PM angle, which showed a validity comparable to our reference angle

Preparation and characterization of PEG-Dex macromolecular schiff base particles and their application on the stabilization of water-in-water emulsion

In this study, polyethylene glycol (PEG) and dextran (Dex) were chemically modified to obtain amino-functionalized PEG (PEG-(NH2)2) and oxidized dextran (ODex). They were subsequently reacted via -NH2 and -CHO groups to synthesize a macromolecular Schiff base particle. The structures, morphologies, and thermal properties of the macromolecular Schiff base particle were characterized using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and thermogravimetry analysis (TGA). The macromolecular Schiff base particle was then employed as a stabilizer to stabilize Dex/PEG water-in-water (W/W) emulsions, and the effects of stabilizer composition, concentration, and dextran oxidation degree on emulsion phase separation and microstructure were investigated. The results from the laser particle size analyzer indicate that the macromolecular Schiff base stabilizers have particle sizes ranging from 100 to 200 nm and exhibit an interpenetrating network structure, as observed in SEM images. A decrease in emulsion droplet size was observed with increasing mass ratio of PEG-(NH2)2 to ODex, ODex oxidation degree, and stabilizer concentration. Rheological analysis showed that the viscosity of W/W emulsions decreased with increasing shear rate. Contact angle measurements indicated that the macromolecular Schiff base stabilizers preferentially interacted with the continuous phase of PEG, thereby promoting emulsion stability.

Optimizing Melamine Sponges Modified With Titanium Dioxide Nanoparticles for Environmental and Industrial Applications

ABSTRACTThis study explored the development and characterizations of a lightweight, cost‐effective, and easily accessible titanium dioxide (TiO2)/melamine sponge with outstanding hydrophobicity, oil absorption/separation, flame retardancy, durability, and electromagnetic wave absorption capacities. Commercial melamine sponges were modified using the silane coupling agent and TiO2 nanoparticles via a solution‐immersion method. Scanning Electron Microscopy revealed the structural integrity and surface morphology with increased surface roughness and uniform distribution of TiO2 particles. The hydrophobicity of the TiO2/sponge was confirmed by contact angle measurements, showing a high value of 145°. The oil absorption capacity and separation efficiency were also quantified, with the modified sponges able to absorb oils at 70 to 120 times their weight while maintaining a separation efficiency above 95% even after 10 reuse cycles. Additionally, the TiO2/sponge exhibited excellent flame resistance, strong mechanical abrasion resistance, and stability in saline environments. Electromagnetic absorption tests over the 2–18 GHz range showed efficient absorption, with reflection loss values below −10 dB at higher frequencies for thicker sponges. These results suggest that TiO2/sponge composites provide multifaceted enhancements, making them suitable for various environmental and industrial applications, including oil spill management and electromagnetic radiation mitigation.

Systematic Evaluation of IMU Sensors for Application in Smart Glove System for Remote Monitoring of Hand Differences.

Human hands have over 20 degrees of freedom, enabled by a complex system of bones, muscles, and joints. Hand differences can significantly impair dexterity and independence in daily activities. Accurate assessment of hand function, particularly digit movement, is vital for effective intervention and rehabilitation. However, current clinical methods rely on subjective observations and limited tests. Smart gloves with inertial measurement unit (IMU) sensors have emerged as tools for capturing digit movements, yet their sensor accuracy remains underexplored. This study developed and validated an IMU-based smart glove system for measuring finger joint movements in individuals with hand differences. The glove measured 3D digit rotations and was evaluated against an industrial robotic arm. Tests included rotations around three axes at 1°, 10°, and 90°, simulating extension/flexion, supination/pronation, and abduction/adduction. The IMU sensors demonstrated high accuracy and reliability, with minimal systematic bias and strong positive correlations (p > 0.95 across all tests). Agreement matrices revealed high agreement (<1°) in 24 trials, moderate (1-10°) in 12 trials, and low (>10°) in only 4 trials. The Root Mean Square Error (RMSE) ranged from 1.357 to 5.262 for the 90° tests, 0.094 to 0.538 for the 10° tests, and 0.129 to 0.36 for the 1° tests. Likewise, mean absolute error (MAE) ranged from 0.967 to 4.679 for the 90° tests, 0.073 to 0.386 for the 10° tests, and 0.102 to 0.309 for the 1° tests. The sensor provided precise measurements of digit angles across 0-90° in multiple directions, enabling reliable clinical assessment, remote monitoring, and improved diagnosis, treatment, and rehabilitation for individuals with hand differences.

Pectin as Pore Agent of Nylon 6.6 Membranes: Fabrication and Characterization

The application of membrane technology in the separation process has led to the technology's present rapid development. Nylon 6.6 polyamide membrane has hydrophilic properties and has advantages such as low fouling tendency and resistance to high temperatures. This research aims to determine the effect of pectin on the characteristics of nylon 6.6 membranes. In this study, the membrane was made from nylon 6.6 using the phase inversion technique. Modification was carried out by adding pectin at variations of 0, 0.25, 0.5, and 0.75% by weight. The IR structure characterization results of the nylon6.6-pectin membrane show the same peak for the-NH group and the OH, C-H, amide I, amide II, amide III, CH2, and C-C groups. Membrane contact angle measurements P0, P0.25, P0.5, and P0.75 were 59.37°, 67.70°, 63.48°, and 58.00° respectively, indicating hydrophilic properties. Meanwhile, the degree of swelling after the membrane was soaked in distilled water for 24 hours showed values of 55.32%, 44.44%, 60.38%, and 63.16% for membranes P0, P0.25, P0.5, and P0.75. The P0.75 membrane has the lowest contact angle which is increasingly hydrophilic and the highest swelling value which indicates the highest absorption level compared to other variations.

Hydrophobization of Chitin Nanofibers by Grafting of Partially 2-Deoxygenated Amyloses Through Enzymatic Approach

In recent years, increased attention has been given to the effective use of chitin nanofibers (ChNFs). We have developed a method to fabricate thinner chitin nanomaterials, called scale-down chitin nanofibers (SD-ChNFs), by a bottom-up procedure at the nanoscale level, with subsequent disintegration by electrostatic repulsion. The surface modification of SD-ChNFs is anticipated to provide new properties and functions for their practical applications. Inspired by our previous reports, which found hydrophobicity in partially 2-deoxygenated (P2D-) amylose obtained by the glucan phosphorylase (GP)-catalyzed enzymatic copolymerization of α-d-glucose 1-phosphate/d-glucal as comonomers, this work investigated the hydrophobization of SD-ChNFs via an enzymatic approach. After the modification of maltooligosaccharide primers on SD-ChNFs was performed by a reductive alkylation toward ChNFs, the grafting of the P2D-amyloses was performed by GP-catalyzed enzymatic copolymerization. 1H NMR analysis supported the production of P2D-amylose-grafted SD-ChNFs with different d-glucose/2-deoxy-d-glucose unit ratios on SD-ChNFs. The X-ray diffraction analysis of the products confirmed that the chain lengths and unit ratios of the grafted polysaccharides strongly affected the entire crystalline structures. Water contact angle measurements of the cast films of the products indicated that successful hydrophobization was achieved by the grafting of P2D-amylose chains with a sufficient chain length, a relatively high 2-deoxy-d-glucose unit ratio, and low crystallinity.

Development of a new composite surface tensiometry parameter for quality evaluation of the maturation process of peloids by contact angle method

With the introduction of the rheological and surface tensiometry approaches, peloids started to be viewed as a geological complex system that needed to be characterized in an integrated way. The development of the Rossi factor revealed variations in the surface free energy of Euganean thermal muds as a function of their quality, conformity, and matura-tion degree. The Rossi factor consents to measuring the contact angle of Fomblin HC/25PFPE Polyperfluoromethylisopropyl Ether by static sessile drop method. The de-velopment of the Kinetic Contact Angle sessile drop methodology, applied to the meas-urement of Fomblin HC/25 PFPE contact angles over time, led to the determination of an integrated surface tensiometry parameter for the evaluation of the maturation process of Euganean thermal peloids, here called the Maturation Mud Index. The Mud Maturation Index is based on the contact angle measurements performed onto peloids surfaces col-lected by Osservatorio Termale Permanente of University of Padova from 2005 to 2010. The Mud Maturation Index has shown a connection to the activity of thermal spas during their pelotherapy season. As a result, this index can serve as a valuable tool for surface tensiometry in assessing the maturation process quality of a peloid based on its level of maturation within the thermal activity of the Euganean Thermal Area in Padova, Italy.