For Fourier Transform Infrared Research Articles

Biomolecular composition of porcine ovarian follicles following in vitro treatment of vitamin D3 and insulin alone or in combination

The study aimed to analyze changes in biomolecular composition of granulosa and theca interna cells of porcine ovarian follicles following in vitro treatment of vitamin D3 and insulin alone or in combination. Medium antral follicles (n = 4/each group) were cultured alone (C; control) or in the presence of 1α,25(OH)2D3 (VD; 100 ng/mL) and insulin (I; 10 ng/mL) separately or in combination, VD and I (VD+I). Then paraplast-embedded ovarian follicles were used for Fourier Transform Infrared (FTIR) spectroscopy and respective histological stainings. FTIR analysis revealed changes in the content of fibrous proteins (mainly collagens) within theca interna following vitamin D3 and insulin co-administration that was verified by Masson’s trichrome staining. Treatment-dependent differences were also observed in the secondary structure of proteins, indicating enhanced conversion to α-helices in response to vitamin D3 and insulin action/interaction in both follicular compartments. In the granulosa and theca interna layers, tendency to lower DNA content in the VD+I group was noted and confirmed by Fulgen’s staining. Finally, altered monosaccharides production in both follicular layers was found. Based on FTIR results, it is possible to attribute the observed alterations to biological processes that could be regulated by vitamin D3 and insulin in the porcine ovarian follicles.

Sensing Liquid- and Gas-Phase Hydrocarbons via Mid-Infrared Broadband Femtosecond Laser Source Spectroscopy.

In this study, we demonstrate the combination of a tunable broadband mid-infrared (MIR) femtosecond laser source separately coupled to a ZnSe crystal horizontal attenuated total reflection (ATR) sensor cell for liquid phase samples and to a substrate-integrated hollow waveguide (iHWG) for gas phase samples. Utilizing this emerging light source technology as an alternative MIR radiation source for Fourier transform infrared (FTIR) spectroscopy opens interesting opportunities for analytical applications. In a first approach, we demonstrate the quantitative analysis of three individual samples, ethanol (liquid), methane (gas), and 2-methyl-1-propene (gas), with limits of detection of 0.3% (ethanol) and 22 ppmv and 74 ppmv (methane and isobutylene), respectively, determined at selected emission wavelengths of the MIR laser source (i.e., 890 cm-1, 1046 and 1305 cm-1). Hence, the applicability of a broadband MIR femtosecond laser source as a bright alternative light source for quantitative analysis via FTIR spectroscopy in various sensing configurations has been demonstrated.

Morphological and lipid metabolism alterations in macrophages exposed to model environmental nanoplastics traced by high-resolution synchrotron techniques.

The release of nanoplastics (NPs) in the environment is a significant health concern for long-term exposed humans. Although their usage has certainly revolutionized several application fields, at nanometer size, NPs can easily interact at the cellular level, resulting in potential harmful effects. Micro/Nanoplastics (M/NPs) have a demonstrated impact on mammalian endocrine components, such as the thyroid, adrenal gland, testes, and ovaries, while more investigations on prenatal and postnatal exposure are urgently required. The number of literature studies on the NPs' presence in biological samples is increasing. However, only a few offer a close study on the model environmental NP-immune system interaction exploited by advanced microscopy techniques. The present study highlights substantial morphological and lipid metabolism alterations in human M1 macrophages exposed to labeled polypropylene and polyvinyl chloride nanoparticles (PP and PVC NPs) (20 μg/ml). The results are interpreted by advanced microscopy techniques combined with standard laboratory tests and fluorescence microscopy. We report the accurate detection of polymeric nanoparticles doped with cadmium selenide quantum dots (CdSe-QDs NPs) by following the Se (L line) X-ray fluorescence emission peak at higher sub-cellular resolution, compared to the supportive light fluorescence microscopy. In addition, scanning transmission X-ray microscopy (STXM) imaging successfully revealed morphological changes in NP-exposed macrophages, providing input for Fourier transform infrared (FTIR) spectroscopy analyses, which underlined the chemical modifications in macromolecular components, specifically in lipid response. The present evidence was confirmed by quantifying the lipid droplet (LD) contents in PP and PVC NPs-exposed macrophages (0-100 μg/ml) by Oil Red O staining. Hence, even at experimental NPs' concentrations and incubation time, they do not significantly affect cell viability; they cause an evident lipid metabolism impairment, a hallmark of phagocytosis and oxidative stress.

A novel infrared spectral preprocessing method based on self-deconvolution and differentiation in the frequency domain

Spectral preprocessing is a crucial step before establishing a multivariate calibration model for Fourier transform infrared (FTIR) spectroscopic analysis. However, a single preprocessing method has limited effects, such as insufficient noise reduction or limited resolution improvement. As two classical preprocessing methods, Fourier self-deconvolution (FSD) and Fourier filtering and differentiation (FFD) have their benefits and drawbacks. FSD has low noise but limited resolution, while FFD could improve resolution and eliminate baseline simultaneously, but is susceptive to noise. By combining FSD and FFD, we design a novelty resolution enhancement method, termed Fourier self-deconvolution differentiation (FSDD), which can significantly improve spectral resolution with good noise and baseline robustness. Partial least squares regression (PLS) is combined with five preprocessing methods, FSD, FFD, direct derivation (DD), Savitsky-Golay smoothing and derivation (SGSD), and FSDD, to analyze the albiflorin dataset and the γ-polyglutamic acid (γ-PGA) fermentation dataset. Compared with other preprocessing methods, FSDD obtained the optimum performance merits, including root mean squared error of prediction (RMSEP), determination coefficient (R2), and Mean Absolute Error (MAE).

The Effect of Sample Preparation Techniques on Lignin Fourier Transform Infrared Spectroscopy.

The characterization and quantification of functional groups in technical lignins are among the chief obstacles of the utilization of this highly abundant biopolymer. Although several techniques were developed for this purpose, there is still a need for quick, cost-efficient, and reliable quantification methods for lignin. In this paper, three sampling techniques for fourier transform infrared (FTIR) spectroscopy were assessed both qualitatively and quantitatively, delineating how these affected the resultant spectra. The attenuated total reflectance (ATR) of neat powders and DMSO-d6 solutions, as well as transmission FTIR using the KBr pelleting method (0.5 wt%), were investigated and compared for eight lignin samples. The ATR of neat lignins provided a quick and easy method, but the signal-to-noise ratios in the afforded spectra were limited. The ATR of the DMSO-d6 solutions was highly concentration dependent, but at a 30 wt%, acceptable signal-to-noise ratios were obtained, allowing for the lignins to be studied in the dissolved state. The KBr pelleting method gave a significant improvement in the smoothness and resolution of the resultant spectra compared to the ATR techniques. Subsequently, the content of phenolic OH groups was calculated from each FTIR mode, and the best correlation was seen between the transmission mode using KBr pellets and the ATR of the neat samples (R2 = 0.9995). Using the titration measurements, the total OH and the phenolic OH group content of the lignin samples were determined as well. These results were then compared to the FTIR results, which revealed an under-estimation of the phenolic OH groups from the non-aqueous potentiometric titration, which was likely due to the differences in the pKa between the lignin and the calibration standard 4-hydroxybenzoic acid. Further, a clear correlation was found between the lower Mn and the increased phenolic OH group content via SEC analyses. The work outlined in this paper give complementary views on the characterization and quantification of technical lignin samples via FTIR.

Design and Optimization of Sustained-Release Trihexyphenidyl Hydrochloride Nanoparticles: Design of the Experiment Approach

Background: Trihexyphenidyl chloride (THP) is an antidyskinetic medication used in single and combination therapy to symptomatically treat Parkinson's disease. Due to its fast metabolism and short elimination of half-life, it causes changes in plasma concentrations and requires frequent dosage. Objectives: The aim of this study was to prepare a sustained release formulation of Trihexyphenidyl chloride (THP). Materials and Methods: Using chitosan as the natural polymer, the polymeric nanoparticles were prepared by using the ionic gelation method. A 32 response surface methodology was used to optimize the effects of independent variables, such as the amount of polymer (X1mg) and the amount of copolymer (X2mg), on dependent variables, such as entrapment efficiency (% EE) (Y1) and drug release (% DR) (Y2). Results: The prepared formulations were evaluated for Fourier transform-infrared (FTIR), X-ray Diffraction, Field scanning micrographs (FESEM), and In vitro drug release. Higher drug entrapment efficiency was observed for batch T11. FTIR confirmed the loading of trihexyphenidyl drug into the chitosan matrix. X-ray diffraction pattern indicated that the degree of crystallinity of pure drug was reduced in the formulated NPs. Conclusion: The drug release from the formulated batches (T1-T13) showed sustained-release action for around 9-14 hrs. The technique reduced the dosing frequencies and possible side effects of trihexyphenidyl chloride.

FTIR autecological analysis of bottom-ice diatom taxa across a tidal strait in the Canadian Arctic

A recent study demonstrated that an Arctic tidal strait, where a shoaled and constricted waterway increases tidally driven sub-ice currents and turbulence, represents a “hotspot” for ice algal production due to a hypothesized enhanced ocean-ice nutrient supply. Based on these findings, we sampled the bottom-ice algal community across the same tidal strait between the Finlayson Islands within Dease Strait, Nunavut, Canada, in spring 2017. Our objective was to examine cellular responses of sea-ice diatoms to two expected nutrient supply gradients in their natural environment: (1) a horizontal gradient across the tidal strait and (2) a vertical gradient in the bottom-ice matrix. Two diatom taxa, Nitzschia frigida and Attheya spp. in bottom-ice sections (0–2, 2–5, and 5–10 cm) under thin snow cover (<5 cm), were selected for Fourier Transform Infrared (FTIR) spectrochemical analysis for lipid and protein content. Results from the FTIR technique strongly supported the existence of a horizontal nutrient gradient across the tidal strait of the Finlayson Islands, while estimates of particulate organic carbon and chlorophyll a concentrations were difficult to interpret. The larger N. frigida cells appeared to be more sensitive to the suspected horizontal nutrient gradient, significantly increasing in lipid content relative to protein beyond the tidal strait. In contrast, the epiphytic diatoms, Attheya spp., were more sensitive to the vertical gradient: above 2 cm in the bottom-ice matrix, the non-motile cells appeared to be trapped with a depleted nutrient inventory and evidence of a post-bloom state. Application of the FTIR technique to estimate biomolecular composition of algal cells provided new insights on the response of the bottom-ice algal community to the examined spatial gradients that could not be obtained from conventional bulk measurements alone. Future studies of sea ice and associated environments are thus encouraged to employ this technique.

Fourier-transform infrared spectroscopy for characterization of liquid protein solutions: A comparison of two sampling techniques

Whereas industrial laboratory systems for Fourier-Transform Infrared (FTIR) spectroscopic characterization have been available for decades, dedicated FTIR solutions for in-line process control or for industrial at-line analysis of protein quality are still scarce. Thus, the present study aimed to compare two industrially viable sampling techniques, namely attenuated total reflectance (ATR) and dry film FTIR spectroscopy, for qualitative and quantitative analysis of liquid protein solutions. For this purpose, two sample sets were acquired: set 1 consisted of 95 protein hydrolysate samples produced in the laboratory from salmon processing by-products, and set 2 consisted of 133 protein hydrolysate samples obtained from an industrial processing plant of poultry by-products. Average molecular weights (AMW) and Brix measurements of protein hydrolysates were used as reference values for obtaining regression models. AMW was predicted with higher accuracy and lower estimation errors using dry film FTIR compared to ATR measurements for both sample types. The difference in predictive performance was higher in poultry hydrolysates because the protein and tissue complexities are higher than in salmon hydrolysates, and information from the amide I region in the FTIR spectra is needed to provide good calibration results. ATR, on the other hand, was more reliable for the prediction of Brix values of protein hydrolysates. The study also showed that FTIR spectroscopy can be used to predict protein quality features of industrially produced protein hydrolysates with a sensitivity of high industrial relevance. Therefore, developing industrially viable portable instruments for at-line process analysis in the food, feed, and biotech industries is a natural next development stage.

Synthesis and characterization of ZnO–TiO2–chitosan–escin metallic nanocomposites: Evaluation of their antimicrobial and anticancer activities

Abstract This work intended to formulate bio-nanocomposites of zinc oxide (ZnO), titanium oxide (TiO2), chitosan, and escin, characterize their physical properties, and evaluate their antimicrobial and anticancer properties. X-ray diffractometers (XRD) and scanning and transmission electron microscopes were applied to characterize the morphology and ultrastructure of chemically synthesized bio-nanocomposites. To investigate the functional groups of bio-nanocomposites, we used Perkin–Elmer spectrometers for Fourier transform infrared (FTIR) analysis and photoluminescence (PL) spectroscopy for PL spectrum analysis. Antimicrobial activities against bacterial and fungal strains were tested with agar well diffusion. Bio-nanocomposites were tested for anticancer effects on a MOLT4 blood cancer cell line using morphological analysis, methyl thiazole tetrazolium assay, apoptosis by acridine orange/ethidium bromide, and mitochondrial membrane potential (ΔΨm). In XRD, FTIR, and PL, the active compounds of ZnO–TiO2, chitosan, and escin peaks were observed. Our bio-nanocomposites demonstrated antimicrobial activity against bacterial and fungal pathogens. The bio-nanocomposite was cytotoxic to MOLT4 cells at an IC50 concentration of 33.4 µg·mL−1. Bio-nanocomposites caused cytotoxicity, changes in cell morphology, and mitochondrial membrane potential degradation, all of which resulted in apoptotic cell death. MOLT4 cells were found to be responsive to bio-nanocomposites based on ZnO–TiO2–chitosan–escin.

μATR-FTIR Spectral Libraries of Plastic Particles (FLOPP and FLOPP-e) for the Analysis of Microplastics

Raman spectral libraries specific to microplastics demonstrated improved spectral matching results when weathered plastics and a variety of particle colors and morphologies were included. Here, we explore if this is true for Fourier transform infrared (FTIR) spectroscopy as well. We present two novel databases specific to microplastics using attenuated total reflection (μATR-FTIR): (1) an FTIR library of plastic particles (FLOPP), containing 186 spectra from common plastic items, across 14 polymer types and (2) an FTIR library of plastic particles sourced from the environment (FLOPP-e), containing 195 spectra across 15 polymer types. Both libraries include particles from a variety of sources, morphologies, and colors. We demonstrate the applicability of these libraries for microplastics research by comparing spectral match results from two microplastic datasets. For this, we use different combinations of libraries including: commercially available reference libraries, an open-access polymer library, and FLOPP and FLOPP-e. Among tests, the greatest mean HQI result was achieved when the greatest number of libraries was included. This work demonstrates that spectral libraries specific to plastic particles found in the environment improve the accuracy of spectral matching and are best used in combination with commercial libraries containing chemical components that are commonly found within plastics and other anthropogenic particles. Multivariate principal component analyses of FLOPP and FLOPP-e spectra confirmed differences among polymer types and higher variation in principal component scores among weathered particles, but no patterns were observed among particle colors or morphologies. These results demonstrate that ATR-FTIR analyses are sensitive to weathering of plastics but not to particle color and morphology.

On the Limit of Detection in Infrared Spectroscopic Imaging.

Infrared (IR) spectroscopic imaging instruments' performance can be characterized and optimized by an analysis of their limit of detection (LOD). Here we report a systematic analysis of the LOD for Fourier transform IR (FT-IR) and discrete frequency IR (DFIR) imaging spectrometers. In addition to traditional measurements of sample and blank data, we propose a decision theory perspective to pose the determination of LOD as a binary classification problem under different assumptions of noise uniformity and correlation. We also examine three spectral analysis approaches, namely, absorbance at a single frequency, average of absorbance over selected frequencies and total spectral distance - to suit instruments that acquire discrete or contiguous spectral bandwidths. The analysis is validated by refining the fabrication of a bovine serum albumin protein microarray to provide eight uniform spots from ∼2.8 nL of solution for each concentration over a wide range (0.05-10 mg/mL). Using scanning parameters that are typical for each instrument, we estimate a LOD of 0.16 mg/mL and 0.12 mg/mL for widefield and line scanning FT-IR imaging systems, respectively, using the spectral distance approach, and 0.22 mg/mL and 0.15 mg/mL using an optimal set of discrete frequencies. As expected, averaging and the use of post-processing techniques such as minimum noise fraction transformation results in LODs as low as ∼0.075 mg/mL that correspond to a spotted protein mass of ∼112 fg/pixel. We emphasize that these measurements were conducted at typical imaging parameters for each instrument and can be improved using the usual trading rules of IR spectroscopy. This systematic analysis and methodology for determining the LOD can allow for quantitative measures of confidence in imaging an analyte's concentration and a basis for further improving IR imaging technology.

FORMULATION AND IN VIVO EVALUATION OF SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM OF RAMIPRIL IN WISTAR RATS

Objective: The aim was to formulate and evaluate self-nanoemulsifying drug delivery systems (SNEDDS) of ramipril, an antihypertensive drug to improve the solubility and bioavailability.
 Methods: Based on solubility studies oil phase (Sefsol 218), surfactant (Acrysol EL135), and cosurfactant (Transcutol P), respectively, were selected to prepare SNEDDS. Ramipril SNEDDS optimized employing box-Behnken design through the study of factors. All formulations were evaluated for particle size, zeta potential (ZP), polydispersity index (PDI), entrapment efficiency (EE), drug content, and in vitro drug release. The optimized formulation was characterized for Fourier transform infrared (FTIR), scanning electron microscopy (SEM), stability studies, and pharmacokinetic study.
 Results: The mean particle size, PDI, ZP, EE, content uniformity, and in vitro drug release profile of optimized ramipril-loaded SNEDDS (RF14) were found to be 75.3±2.21nm, 0.126±0.05, −24.4±5.78mV, 98.74±1.97%, 99.52±1.67%, and 98.65±1.73%, respectively. FTIR studies revealed that there is no incompatibility between drug and excipients, SEM images exhibited nanoparticles to be more porous and in spherical shape. Stability studies indicated formulation was stable for 6 months. In vivo studies were conducted for optimized formulation RF14, the Tmax was found to be 0.5±0.62 and 0.5±0.95 h for the optimized and commercial formulations respectively, while Cmax was 25.16±1.73 ng/mL was significant (p<0.05) as compared to the ramipril pure drug 8.02±0.086 ng/mL. AUC0-t of the SNEDDS formulation was higher 355.49±1.76ng h/ml compared to pure drug 116.57±1.64 ng h/ml indicated higher amount of drug concentration in blood proving better systemic absorption of ramipril from SNEDDS formulation as compared to the pure drug.
 Conclusion: It is concluded from the results that ramipril was successfully formulated into SNEDDS with higher concentration with fast action.

IN VIVO EVALUATION OF QUINAPRIL TRILAYERED MATRIX TABLETS

Objective: The aim was to design, formulate, and evaluate the trilayer matrix tablets incorporated with quinapril for extend drug release.
 Methods: Quinapril trilayer matrix tablets were formulated using design of experiment software wherein initially 27 formulations (QF1-QF27) were designed for active layer from which one best formulation was chosen based on drug content, swelling index and in vitro release studies. The chosen formulation was formulated into extended release trilayed matrix tablet by varying proportions of polymers by direct compression and was evaluated for various physicochemical parameters, drug release. Best formulation was characterized for Fourier transform infrared (FTIR), stability, and pharmacokinetic study.
 Results: Out of 27 formulations highest drug release was exhibited by QF16 (98.85%) which was formulated into trilayer matrix tablets (AQF16- HQF16). Out of which EQF16 was found to exhibit highest values with 98.42% swelling index, 99.56% drug content, and 99.72% drug release in 24 h. All quinapril trilayer formulations showed zero-order and first-order for marketed product. The optimized formulation EQF16 was found to exhibit no interaction with excipients interpreted by FTIR and no significant changes were observed after loading for stability. In vivo studies conducted using optimized formulation EQF16 attained peak drug concentration (Tmax) of 4.0±0.06 and 1.0±0.03 h for the optimized and commercial formulations, respectively, while mean maximum drug concentration (Cmax) was 302.64±0.07 ng/mL and was significant (p<0.05) as compared to the quinapril marketed product formulation 358.78±0.75 ng/mL.
 Conclusion: Hence, quinapril was successfully formulated into trilayer matrix tablet and found to be stable.

ACUTE EXERCISE CHANGES THE FOURIER-TRANSFORM INFRARED SPECTRA PROFILE IN INDIVIDUALS WITH HYPERTENSION AND OTHER CARDIOVASCULAR RISK FACTORS: EFFECT OF THE SESSION DURATION

Objective: Evaluate the acute effects of two sessions of moderate exercise with different durations, on the metabolomic profile of adults with cardiovascular risk factors or established cardiovascular disease. Design and method: 15 adults (age: 66.5 ± 7.6 years; BMI: 26.8 ± 3.7 kg/m2; 80% women) were recruited in a community exercise program of a primary health care centre. They performed two sessions of moderate intensity aerobic (endurance) exercise with different duration periods (30 versus 45 min). Venous blood was collected before and after each exercise session. Samples were centrifuged and the plasma was used for Fourier-transform infrared (FTIR) spectroscopy analysis. The spectra were acquired, and multivariate analysis applied. Results: FTIR analysis showed good discrimination between pre- and post- the 30 min session in the 1700–1600 cm-1 region (Amide I band) and 1500–900 cm-1 region (fingerprint region). Principal component analysis of the fingerprint region revealed that the post-exercise samples presented peaks related to glycogen (1079 cm-1) and collagen (1458 cm-1, 1339 cm-1), which reflect the exercise training. Pre-exercise samples had peaks related to ribose (996 cm-1) and carbohydrates (1045 cm-1) that are sources of energy that are ready to be used during the session. Partial least squares regression of the Amide I region also showed differences after exercise. In the baseline, the participants seem to have higher levels of antiparallel β-sheets (1690 cm-1) and side chains (1611 cm-1), which are linked with proteins prone to aggregate. However, after exercise, the participants showed a peak related to random coils (1639 cm-1), which may indicate a transitional state for the β-sheet rich protein to a more stable profile. In the 45 min session no differences were observed after the session in the amide I region. Conclusions: A single aerobic exercise, irrespective of the duration, does not induce deleterious changes in the metabolomic profile. Only the 30 min session promoted a positive alteration in the quality of the proteins; this change in the quality of the proteins and the fingerprint region indicates a possible alteration associated with the duration of the exercise.

Potential for Fourier transform infrared (FTIR) spectroscopy toward predicting antioxidant and phenolic contents in powdered plant matrices.

Mid-infrared spectroscopy is finding an increasing number of applications; however, many of its potential uses remain unexplored. In this study, mid-infrared spectroscopy is applied to predict total antioxidant capacity and phenolic contents of powdered matrices of 14 diverse plant species. In all instances, the optimum prediction models were found using standard normal variate smoothing as a pre-processing method. The results show high correlation between the FTIR predicted and chemically determined values, namely R2 values of 0.962 for total phenolics, 0.829 for cupric reducing antioxidant potential (CUPRAC) and 0.911 for ferric reducing antioxidant potential (FRAP). The relative RMSE found for validation indicated that total phenolic content could be predicted with higher accuracy than CUPRAC or FRAP. This pilot study highlights the promise of this technology for plant breeders and a range of industries where rapid screening of many samples for antioxidant and/or phenolic content is envisaged.

Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy Characterization of Adhesive Produced From Polystyrene Waste

In this study, the optimized adhesive formulated from polystyrene waste was characterized for Fourier transform infrared (FTIR) spectra, Scanning Electron Microscopy (SEM) / Energy Dispersive X-ray (EDX) spectroscopy, solubility, density and water absorption for identification of existing functional group(s), morphology, elemental compositions, etc. The results revealed that polystyrene, unsaturated hydrocarbon has been degraded to form a new product containing aromatic compounds. SEM morphology showed well mixed blended adhesive with silver-like appearance due to additives and EDX revealed 12 existing elemental compositions with their corresponding percentage atomic weights as follows; carbon 93.14 %, hafnium 1.44 %, vanadium 1.66 %, chromium 1.40 %, bromine 0.47 %, palladium 0.26 %, copper 0.43 %, nickel 0.31 %, cobalt 0.29 %, potassium 0.38 %, iron 0.15 % and manganese 0.08 %. The produced polystyrene adhesive was sparsely soluble in water after 30 minutes; it has a density of 1041 kg/m3 and does not absorb moisture. Because of these results, the adhesive from polystyrene waste could serve as green adhesive, since there are no threats of toxic substance emission from the spectral analysis since most of the elements are used as a supplement in pharmaceuticals and catalyst in process industries.

Novel polyisoprene based UV-activated oxygen scavenging films and their applications in packaging of beef jerky

In this study, polyisoprene (PS), a natural rubber with 5, 10, and 20% (w/w) concentrations, was incorporated into low-density polyethylene (LDPE) matrix to develop novel oxygen-scavenging films. UV light was utilized to activate the oxygen-scavenging reaction in the film. The resulting OS films were analyzed for Fourier transform infrared (FTIR) spectra, mechanical, barrier, thermal properties, and oxygen-scavenging capabilities. The tensile strength (TS) and elongation break (EB) of the LDPE/PS 20% films did not affect with the addition of PS and increased 6.13 ± 0.43 to 6.91 ± 0.77 MPa and from 121.39 ± 0.23 to 132.01 ± 0.93%, respectively. However, barrier properties were greater than those of pure LDPE films. The thermal stability of the resulting LDPE/PS films was improved upon the introduction of PS. The prepared LDPE/PS 10% and 20% films had 13.6 and 16.72 mL O2/g oxygen-scavenging capacity, respectively. Beef jerky packed with the LDPE/PS 20% film increased its stability, color, and pH during storage. Further, on analyzing lipid oxidation, LDPE/PS 20% was effective as butylated hydroxytoluene to maintain the oxidative stability of beef jerky. Jerky packed with LDPE/PS 10% and 20% films had a significantly decreased microbial count after storage for 90 d (p < 0.05).

FORMULATION AND EVALUATION OF LIQUISOLID COMPACTS OF LORNOXICAM

Objective: Objective of the present investigation was to enhance the solubility and dissolution rate of poorly water-soluble drug lornoxicam using liquisolid technique with comparative determination of in vitro release profile of liquisolid compacts and conventional formulation of lornoxicam.&#x0D; Methods: Formulation was prepared by a liquisolid technique using different drug concentration in a liquid vehicle and different carrier/coating ratio. Prepared liquisolid compact was evaluated for Fourier transform infrared (FTIR) spectra analysis, differential scanning calorimetry (DSC), X-ray diffraction (P-XRD), scanning electron microscopy (SEM) and in vitro dissolution study.&#x0D; Results: The result showed that liquisolid compacts of lornoxicam displayed significantly higher drug release rate as compared to pure drug and conventional tablet prepared. The results of both DSC and X-ray crystallography indicated loss of crystallinity of the drug upon formulated into the liquisolid compact.&#x0D; Conclusion: Dissolution rate of the drug from liquisolid compacts was affected by changing the drug concentration and excipient ratio. The liquisolid technique appeared to be a promising approach for improving the dissolution of poorly soluble drug lornoxicam.

Synthesis and Characterization of Alkylated Graphene Oxide (AGO) and Reduced Graphene Oxide (ARGO)

Abstract This work focuses on alkylation as an effective method to cope with mixing issue between both graphene oxide (GO) and reduced graphene oxide (RGO) with hydrophobic polymer such as polypropylene. Alkylation is an amidation reaction to graft alkyl groups onto GO and RGO surfaces. The successful grafting of alkyl groups on GO and RGO to form alkylated graphene oxide (AGO) and alkylated reduced graphene oxide (ARGO) were supported by several analysis. Scanning Electron Microscopy (SEM) micrographs showed the formation of wrinkle surfaces in higher degree for AGO and ARGO, as compared with GO. No agglomeration was seen on both surfaces as well. For Fourier Transform Infrared (FTIR) spectroscopy, the appearance of new peaks at around 2921 cm-1, 2850 cm-1 and 1424 cm-1 confirmed the alky chains were grafted successfully. Furthermore, ID/IG ratio for AGO and ARGO were almost similar, proving that no further amount of defect onto structure of AGO was formed in the reduction of AGO. Lastly, for AGO and ARGO, the X-ray Diffraction (XRD) spectra showed the presence of new peaks at 2θ = 20.26° and 20.18°, respectively. Several other peaks can be seen as well, to prove successful alkylation which implied the grafting of alkyl groups provides more reactive site for stronger interfacial reaction with polymer to improve mechanical properties.

A Fully Automated Robot for the Preparation of Fungal Samples for FTIR Spectroscopy Using Deep Learning

Manual preparation of fungal samples for Fourier Transform Infrared (FTIR) spectroscopy involves sample washing, homogenization, concentration and spotting, which requires time-consuming and repetitive operations, making it unsuitable for screening studies. This paper presents the design and development of a fully automated robot for the preparation of fungal samples for FTIR spectroscopy. The whole system was constructed based on a previously-developed ultrasonication robot module, by adding a newly-designed centrifuge module and a newly-developed liquid handling module. The liquid handling module consists of a high accuracy electric pipette for spotting and a low accuracy syringe pump for sample washing and concentration. A dual robotic arm system with a gripper connects all of the hardware components. Furthermore, a camera on the liquid handling module uses deep learning to identify the labware settings, which includes the number and positions of well plates and pipette tips. Machine vision on the ultrasonication robot module can detect the sample wells and return the locations to the liquid handling module, which makes the system hand-free for users. Tight integration of all the modules enables the robot to process up to two 96-well microtiter (MTP) plates of samples simultaneously. Performance evaluation shows the deep learning based approach can detect four classes of labware with high average precision, from 0.93 to 1.0. In addition, tests of all procedures show that the robot is able to provide homogeneous sample spots for FTIR spectroscopy with high positional accuracy and spot coverage rate.