scholarly journals The Effect of Cellulose Nanocrystal Suspension Treatment on Suspension Viscosity and Casted Film Property

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2168
Author(s):  
Yucheng Peng ◽  
Brian Via
Keyword(s):  
Near Infrared ◽  
Critical Role ◽  
Degree Of Crystallinity ◽  
Film Property ◽  
Film Properties ◽  
Rotational Viscometer ◽  
Industrial Sectors ◽  
Magnetic Stirrer ◽  
Suspension Viscosity ◽  
Pre Treatment

Cellulose nanocrystals (CNCs) have attracted significant interest in different industrial sectors. Many applications have been developed and more are being explored. Pre-treatment of the suspension plays a critical role for different applications. In this study, different pre-treatment methods, including homogenization, ultrasonication, and mixing with a magnetic stirrer were applied to a CNC suspension. After treatment, the rheological behaviors of the treated CNC suspensions were characterized using a rotational viscometer. The treated suspensions were then used to cast films for characterization by ultraviolet-visible (UV-Vis) and Fourier transform near-infrared spectroscopy (FT-NIR). All the CNC suspensions demonstrated a shear thinning phenomena. Homogenization or ultrasonication significantly decreased the suspension viscosity compared with the suspension mixed by a magnetic stirrer. The viscosity of CNC suspension changed with time after treatment and settlement of treated CNC suspensions in room conditions increased the viscosity dramatically with time. Different UV and visible light interferences were observed for the CNC films generated from suspensions treated by different methods. The degree of crystallinity of the CNC films evaluated by FT-NIR showed that the film from suspension treated by homogenization and ultrasonication has the highest degree of crystallinity. Pre-treatments of CNC suspension affected the suspension viscosities and formed film properties.

Near Infrared Spectroscopy Estimation of Feeding Value of Forage Perennial Grasses in Breeding Programmes by Global and Specific Calibrations. Estimation of Chemical Composition and Digestibility

1998 ◽  
Vol 6 (1) ◽  
pp. 153-165 ◽  
Author(s):  
Y. Naydenova ◽  
P. Tomov ◽  
P. Dardenne
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Predictive Models ◽  
Near Infrared ◽  
Perennial Grasses ◽  
Standard Errors ◽  
Breeding Programmes ◽  
Feeding Value ◽  
Pre Treatment ◽  
Better Than

Near infrared (NIR) spectral analysis with a NIRSystems 6500 monochromator was applied to evaluate accuracy of predictive models for forage quality in clone breeding processes of the original Bulgarian varieties over different cuts and years. The varieties were the perennial grasses: Dactylis glomerata L., Festuca arundinacea Schreb. and Bromus inermis Leyss. Global calibrations for the 418 perennial grass samples and specific calibrations for each single grass species and internal cross-validations were performed by the PLS regression method. The effect of different spectral data pre-treatments was investigated on the residual standard errors of the NIR predictive models. Among 60 calibration equations, the model with the lowest SECV value was retained for each parameter in each database. No particular data pre-treatment was really better than the other ones. Generally, the best results of the global calibrations were obtained with SNVD and MSC. For the specific calibrations, SNVD and WMSC were the best treatments. In both cases, the first or second derivatives were needed after the first pre-treatment. Chemical composition and in vitro enzymatic digestibility of clones were predicted with accuracy similar to that of classical laboratory methods. For the cell wall component contents, the standard errors of cross-validation SECV(%DM) ranged from 0.49 for ADL ( Festuca) to 2.02 for NDF ( Dactylis). The digestibilities of dry and organic matter, IVDMD and IVOMD, were estimated with SECVs from 2.6 to 3.0%, the relative intake, from 0.06 to 0.09 rel% body weight and the relative feeding value, from 4.39 to 5.64 rel%. The global calibration models offer an acceptable accuracy for the estimation of the cell wall nutrient contents, the digestibility and the nutritive value. The standard errors of prediction of specific single species calibrations with smaller numbers of terms were lower in 60% of the cases than those obtained from the best global calibrations with higher numbers of terms. On average, SECVs from specific calibrations are better than those from global calibrations, but the differences are quite small, and for the prediction of totally new samples (new crops, another year), the global calibrations will detect less outlier samples. Even with very high variability between cuts and years, NIR spectroscopy is able via ANOVA GL Models to sort clones on their feeding value and to provide relevant information for the breeding programmes.

Modification of Bi:YIG film properties by substrate surface ion pre-treatment

2014 ◽  
Vol 55 ◽  
pp. 19-25 ◽  
Author(s):  
A.N. Shaposhnikov ◽  
A.R. Prokopov ◽  
A.V. Karavainikov ◽  
V.N. Berzhansky ◽  
T.V. Mikhailova ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Film Properties ◽  
Pre Treatment

scholarly journals One-Step Quaternization/Hydroxypropylsulfonation to Improve Paste Stability, Adhesion, and Film Properties of Oxidized Starch

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1110 ◽  
Author(s):  
Wei Li ◽  
Zhenzhen Xu ◽  
Zongqian Wang ◽  
Jian Xing
Keyword(s):  
Tensile Strength ◽  
Degree Of Crystallinity ◽  
Trimethylammonium Chloride ◽  
Film Properties ◽  
Moisture Regain ◽  
Breaking Elongation ◽  
End Use ◽  
Paste Viscosity ◽  
The Stability ◽  
Viscosity Stability

To investigate the influences of quaternization/hydroxypropylsulfonation on viscosity stability, adhesion to fibers and film properties of oxidized tapioca starch (OTS) for ameliorating its end-use ability in applications such as warp-sizing and paper-making, a series of quaternized and hydroxypropylsulfonated OTS (QHOTS) samples were synthesized by simultaneous quaternization and hydroxypropylsulfonation of OTS with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHPTAC) and 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na). The QHOTS granules were characterized by Fourier transform infra-red spectroscopic and scanning electron microscope techniques. Apparent viscosity and viscosity stability were determined, and adhesion was evaluated by measuring the bonding force of starch to the fibers. Film properties were also estimated in terms of tensile strength, breaking elongation, bending endurance, degree of crystallinity, and moisture regain. It was showed that quaternization/hydroxypropylsulfonation was capable of obviously improving viscosity stability of gelatinized OTS paste, enhancing bonding forces of OTS to cotton and polylactic acid (PLA) fibers, increasing breaking elongation, bending endurance and moisture regain of film and decreasing its tensile strength and degree of crystallinity, thereby obviously stabilizing paste viscosity, improving adhesion to fibers and lessening film brittleness. Increasing the level of quaternization/hydroxypropylsulfonation favored improvement in the stability, enhancement in adhesion and decrease in brittleness. The QHOTS showed potential in the applications of cotton and PLA sizing.

scholarly journals The Effect Of Thickness on The Optical Properties Of ZnS

2007 ◽  
Vol 4 (4) ◽  
pp. 647-652
Author(s):  
Baghdad Science Journal
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Near Infrared ◽  
High Vacuum ◽  
Ultra Violet ◽  
Infrared Region ◽  
Complex Dielectric Constant ◽  
Film Properties ◽  
Corning Glass ◽  
Different Thickness

Zinc sulfide(ZnS) thin films of different thickness were deposited on corning glass with the substrate kept at room temperature and high vacuum using thermal evaporation technique.the film properties investigated include their absorbance/transmittance/reflectance spectra,band gap,refractive index,extinction coefficient,complex dielectric constant and thickness.The films were found to exhibt high transmittance(59-98%) ,low absorbance and low reflectance in the visible/near infrared region up to 900 nm..However, the absorbance of the films were found to be high in the ultra violet region with peak around 360 nm.The thickness(using optical interference fringes method) of various films thichness(100,200,300,and 400) nm.The band gap measured was found to be in the range (3.52 -3.78 )eV.

THE EFFECT OF LEG PREFERENCE ON MECHANICAL EFFICIENCY DURING SINGLE-LEG EXTENSION EXERCISE

2021 ◽  
Author(s):  
Massimo Venturelli ◽  
Cantor Tarperi ◽  
Chiara Milanese ◽  
Luca Festa ◽  
Luana Toniolo ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Near Infrared ◽  
Isometric Force ◽  
Fiber Type ◽  
Vastus Lateralis ◽  
Critical Role ◽  
Inverse Correlation ◽  
Mechanical Efficiency ◽  
Peak Power Output ◽  
Leg Extension

To investigate how leg preference affects net efficiency (ηnet), we examined central and peripheral hemodynamics, muscle fiber type, activation and force of preferred (PL) and non-preferred (NPL) leg. Our hypothesis was that PL greater efficiency could be explained by adaptations and interactions between central, peripheral factors and force. Fifteen young participants performed single-leg extension exercise at absolute (35W) and relative (50%peak power-output (Wpeak)) workloads with PL and NPL. Oxygen uptake, photoplethysmography, Doppler ultrasound, near-infrared-spectroscopy deoxy-hemoglobin [HHb], integrated electromyography (iEMG), maximal isometric force (MVC), rate of force development (RFD50-100) and muscle biopsies of both vastus lateralis, were studied to assess central and peripheral determinants of ηnet. During exercise executed at 35W, ηnet was 17.5±5.1% and 11.9±2.1% (p<0.01) in NP and NPL respectively, while during exercise at the 50% of Wpeak, was in PL = 18.1±5.1% and in NPL = 12.5±1.9 (p<0.01). The only parameter correlated with ηnet was iEMG which showed an inverse correlation for absolute (r=-0.83 and -0.69 for PL and NPL) and relative workloads (r=-0.92 and -0.79 for PL and NPL). MVC and RFD50-100 were higher in PL than in NPL but not correlated to ηnet. This study identified a critical role of leg preference in the efficiency during single-leg extension exercise. The whole spectrum of the central and peripheral, circulatory and muscular determinants of ηnet did not explain the difference between PL and NPL efficiency. Therefore, the lower muscle activation exhibited by the PL is likely the primary determinant of this physiological phenomenon.

scholarly journals The Development and Treatment of Lymphatic Dysfunction in Cancer Patients and Survivors

Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2280
Author(s):  
Melissa B. Aldrich ◽  
John C. Rasmussen ◽  
Caroline E. Fife ◽  
Simona F. Shaitelman ◽  
Eva M. Sevick-Muraca
Keyword(s):  
Breast Cancer ◽  
Head And Neck Cancer ◽  
Head And Neck ◽  
Cancer Patients ◽  
Cancer Progression ◽  
Neck Cancer ◽  
Cancer Metastasis ◽  
Near Infrared ◽  
Critical Role ◽  
Lymphatic Function

Breast-cancer-acquired lymphedema is routinely diagnosed from the appearance of irreversible swelling that occurs as a result of lymphatic dysfunction. Yet in head and neck cancer survivors, lymphatic dysfunction may not always result in clinically overt swelling, but instead contribute to debilitating functional outcomes. In this review, we describe how cancer metastasis, lymph node dissection, and radiation therapy alter lymphatic function, as visualized by near-infrared fluorescence lymphatic imaging. Using custom gallium arsenide (GaAs)-intensified systems capable of detecting trace amounts of indocyanine green administered repeatedly as lymphatic contrast for longitudinal clinical imaging, we show that lymphatic dysfunction occurs with cancer progression and treatment and is an early, sub-clinical indicator of cancer-acquired lymphedema. We show that early treatment of lymphedema can restore lymphatic function in breast cancer and head and neck cancer patients and survivors. The compilation of these studies provides insights to the critical role that the lymphatics and the immune system play in the etiology of lymphedema and associated co-morbidities.

scholarly journals Effect of pneumatic compression therapy on lymph movement in lymphedema-affected extremities, as assessed by near-infrared fluorescence lymphatic imaging

2017 ◽  
Vol 10 (02) ◽  
pp. 1650049 ◽  
Author(s):  
Melissa B. Aldrich ◽  
Deborah Gross ◽  
John Rodney Morrow ◽  
Caroline E. Fife ◽  
John C. Rasmussen
Keyword(s):  
Near Infrared ◽  
Contractile Activity ◽  
Lymphatic Vessels ◽  
Compression Therapy ◽  
Direct Visualization ◽  
Near Infrared Fluorescence ◽  
Pre Treatment ◽  
And Function ◽  
Lymphatic Imaging

Previous studies have shown cost effectiveness and quality-of-life benefit of pneumatic compression therapy (PCT) for lymphedema (LE). Insurers, such as the Centers for Medicare/Medicaid (CMS), however, desire visual proof that PCT moves lymph. Near-infrared fluorescence lymphatic imaging (NIRFLI) was used to visualize lymphatic anatomy and function in four subjects with primary and cancer treatment-related LE of the lower extremities before, during, and after PCT. Optically transparent and windowed PCT garments allowed visualization of lymph movement during single, 1[Formula: see text]h PCT treatment sessions. Visualization revealed significant extravascular and lymphatic vascular movement of intradermally injected dye in all subjects. In one subject with sufficient patent lymphatic vessels to allow quantification of lymph pumping velocities and frequencies, these values were significantly increased during and after PCT as compared to pre-treatment values. Lymphatic contractile activity in patent lymphatic vessels occurred in concert with the sequential cycling of PCT. Direct visualization revealed increased lymphatic function, during and after PCT therapy, in all LE-affected extremities. Further studies are warranted to assess the effects of PCT pressure and sequences on lymph uptake and movement.

Multivariate Calibration and Chemometrics for near Infrared Spectroscopy: Which Method?

2000 ◽  
Vol 8 (4) ◽  
pp. 229-237 ◽  
Author(s):  
Pierre Dardenne ◽  
George Sinnaeve ◽  
Vincent Baeten
Keyword(s):  
Near Infrared ◽  
Multivariate Calibration ◽  
Scatter Correction ◽  
Large Data ◽  
Data Sets ◽  
Agricultural Commodity ◽  
Regression Methods ◽  
Standard Normal Variate ◽  
Pre Treatment ◽  
Artificial Neural Network Ann

The four most important regression methods are evaluated on very large data sets: Multiple Linear Regression (MLR), Partial Least Squares (PLS), Artificial Neural Network (ANN) and a new concept called “LOCAL” (PLS with selection of a calibration sample subset of the closest neighbours for each sample to predict). The Standard Errors of Prediction ( SEPs) are statistically tested and the results show that the regression methods are almost equal and that the data matrices are more important than the fitting methods themselves. The types of pre-treatments (Multiplicative Scatter Correction, Detrend, Standard Normal Variate, derivative etc.) of the spectra are too numerous to be able to test all the combinations. For each test, the pre-treatment found as the best with the PLS method is fixed for the other ones. The second part of the paper emphasises the importance of the number of samples. If any agricultural commodity, and probably any kind of product measured by an NIR instrument, can be considered as a mixture of several constituents, the databases built by collecting actual samples bringing new information can reach hundreds, if not thousands, of samples.

scholarly journals Artemisinin Attenuated Oxidative Stress and Apoptosis by Inhibiting Autophagy in MPP+-treated SH-SY5Y Cell 

2020 ◽  
Author(s):  
Junqiang Yan ◽  
Hongxia Ma ◽  
Xiaoyi Lai ◽  
Jiannan Wu ◽  
Anran Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Dopaminergic Neurons ◽  
Artemisia Annua ◽  
Cell Model ◽  
Neuroprotective Effect ◽  
Critical Role ◽  
Neuroprotective Effects ◽  
Pre Treatment

Abstract Background Parkinson's disease (PD) is the second most common neurodegenerative disease after Alzheimer's. The drugs currently used to treat PD cannot inhibit the development of PD, and long-term use produces severe drug resistance and adverse reaction. Artemisinin (ART) is an active ingredient of Artemisia annua and has a neuroprotective effect, but the mechanism is still unclear. This study was designed to investigate the neuroprotective effect of ART in MPP+-treated SH-SY5Y cells. Results There was no significant cytotoxicity when the ART concentration was under. 40μM. The 20μM ART for 24h could increase the cell viability by reducing oxidative stress and cell apoptosis in MPP+-treated SH-SY5Y cell. In addition, immunoblot and immunofluorescence results showed that MPP+ treatment increased the expression of Beclin1, LC3II/LC3I and decreased the expression of P62, while ART can reverse the changes caused by MPP+. Discussion More and more researches reported that ART and its derivates have neuroprotective effects through anti-oxidant and anti-apoptosis. we found that pre-treated cells with 20μM ART for 4h could significantly increase the viability in Parkinson's disease cell model. The oxidative stress and apoptosis were the main reason for the degeneration of dopaminergic neurons, while artemisinin can attenuate oxidative stress and apoptosis in MPP+-lesioned dopaminergic neurons. The levels of autophagy proteins LC3II/I, Beclin1 and P62 also showed that MPP+ increased the autophagy level, and pre-treatment with ART decreased the autophagy level, which may be the pathological mechanism for artemisinin to reduce oxidative stress damage and apoptosis. Conclusions These results indicate that ART exerts a positive effect on MPP+-treated SH-SY5Y cells in terms of anti-oxidative stress and anti-apoptosis. These effects may be related to autophagy. These findings contribute to a better understanding of the critical role of ART in PD treatment.

scholarly journals Infrared and Millimeter Views of the Helix: the Nearest, Massive, Neutral Remnant of a Circumstellar Envelope

1999 ◽  
Vol 191 ◽  
pp. 425-430 ◽  
Author(s):  
P.J. Huggins ◽  
P. Cox ◽  
T. Forveille ◽  
R. Bachiller ◽  
K. Young
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Critical Role ◽  
Ring Structure ◽  
Circumstellar Envelope ◽  
3 Dimensional ◽  
Optical Images ◽  
Formation And Evolution ◽  
Visualization Techniques

We present new, infrared and millimeter views of the Helix nebula which illustrate the critical role of remnant, neutral AGB envelopes in the formation and evolution of planetary nebulae. Large scale ∼ 1 000″ mapping of the entire nebula in the CO (J = 2 − 1) line with the CSO reveals the global structure of the envelope. The CO emission forms the familiar ring structure seen in optical images of the Helix, and indicates a massive remnant with ≳ 50% the mass of the ionized nebula. High resolution CO mapping with the IRAM 30 m telescope shows that the whole envelope is fragmented into an intricate array of small clumps, closely related to the cometary globules seen in the central, ionized cavity. 5–17 μm spectroscopy of the Helix with ISOCAM reveals a remarkable near infrared spectrum, dominated by the pure (v = 0 − 0) rotational lines of H2. The H2 lines are excited to a temperature of ∼ 900 K, and likely arise in warm, outer layers of the small clumps seen in CO. Imaging of the H2 emission with ISOCAM over the whole nebula provides a striking portrait of the fragmented neutral envelope. 3-dimensional views of the envelope are also presented, based on CO mapping and using 3-dimensional visualization techniques. Point symmetries dominate the toroidal structure, and suggest an origin for the Helix in equatorial mass-loss on the AGB, shaped by the action of bipolar outflows or jets.

Sign in / Sign up

Export Citation Format

Share Document