Total Reflectance Fourier Transform Infrared Research Articles

The effect of Styrene Maleic Anhydride on the microstructure evolution of PSF-based membrane prepared by thermal-induced phase separation method

Polysulfone (PSF) and Styrene Maleic Anhydride (SMA) were blended by thermally induced phase separation method in the preparation of membranes for water treatment. Dipropylene Glycol Dibenzoate (DPGDB) was used as a diluent which was extracted using ethanol. The increase in SMA concentration was positively confirmed by monitoring the intensity of the peak at 1779 cm−1 characteristic to CO in the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) spectra. This observation was validated by elemental quantification using X-Ray Photoelectron Spectroscopy (XPS). Scanning Electron Microscopy (SEM) showed that the surface and cross-section morphology changed with an increase in SMA concentration. The average membrane pore size increased from 38.25 nm to 61.30 nm. In the same regard, average porosity increased from 16% to 57%. These observations were attributed to the effect of SMA molecules on the liquid-solid phase separation. The effect of SMA on wettability of the membrane was investigated by contact angle measurements where it was found that the hydrophilicity decrease with an increase in SMA content. The hydrophilicity had positive influence in membrane fouling resistance. The antifouling propensity reached up to 91% when the SMA content was 2% wt/wt compared to the base membrane which was 86%. The maximum pure water flux was found to be 147 Lm−2 h−1 when the SMA content was 2%. It decreases to 33 Lm−2 h−1 when SMA increases to 10% wt/wt. On the other hand, Bovine Serum Albumin (BSA) rejection increased with an increase in SMA concentration. The highest rejection was 92 ± 3%.

Assessment of aqueous cleaning of acrylic paints using innovative cryogels

Waterborne acrylic paints have been widely used by artists since their development in the late 50s. Their cleaning, i.e., the removal of mainly airborne dust and grime, is a challenging operation, because acrylics are very sensitive to solvents in a wide range of polarity. Even if aliphatic and low-molecular weight aromatic hydrocarbons are less prone to interact with the hydrophilic components of the acrylic paint layer, the use of water is necessary since it grants better cleaning performances. In this paper, three acrylic commercial paints from Liquitex® (USA) were selected and characterized using Fourier Transform Infrared spectroscopy (FT–IR) and pyrolysis – gas chromatography – mass spectrometry (Py-GC–MS). The removal of artificial soil from these paint films was carried out using novel highly retentive PVA-based cryogels that have been recently developed to avoid the uncontrolled wetting of water-sensitive artistic surfaces. Their cleaning efficiency was evaluated using Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM). Finally, an ATR-FTIR and 2D FTIR Imaging study about the residues left by the gels was carried out by comparing the cryogel with a Velvesil Plus® emulsion, a gel-like silicone polyether copolymer used in the recent past to create a stable water-in-oil emulsion, and still available on the market to conservators. In conclusion, the cryogel granted a safe and satisfactory cleaning action and a residue-free soil removal from acrylic paint films, overcoming the drawbacks of traditional cleaning methods.

Printing of UV-curable transparent conductive polymer composite

The aim of the study is to produce an UV-curable transparent conductive film. First of all, ZnO microparticles were synthesized and modified with acrylate. Then, UV-curable coating formulations having acrylate-modified ZnO microparticles were prepared. Composite polymeric matrix has been printed on the glass surface with screen printing. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy, current–voltage meter, goniometer, SEM and thermogravimetric analysis were used for chemical structure, electrical surface and thermal properties. As a result; all materials were successfully produced and dispersed onto the surface homogenously. It has been observed that ZnO added screen-printed lines increased the conductivity. UV-curable coating formulations containing ZnO were effectively applied by screen printing.

The Effect of Prescription on the Framework of Lipid Matrix and In Vitro Properties.

To clarify the inner framework and relative properties in vitro of Lyotropic liquid crystal (LLC) based on various prescriptions by using hydrophilic sinomenine hydrochloride (SH) and lipophilic cinnamaldehyde (CA) as model drugs. Phase structures were checked by polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS). Rheological studies and Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) analysis were carried out to reveal their molecular interactions. In vitro release and skin permeation were conducted by Franz diffusion cell. PLM and SAXS showed double diamond cubic crystal. All the samples displayed characteristics of non-Newtonian fluid, and the molecular interactions increased with the reducing water. ATRFTIR showed that the strongest strength of hydrogen bond emerged in the formulation with 32% water. Released SH of S2 and S3 arrived over 80%, while S1 only reached 45%, and that of CA was about 23%. Water-rich prescription gave higher percutaneous penetration for hydrophilic drugs, whereas no significant difference existed in CA permeation. Proportion of Phytantriol to water determined the LLC assembling and affected the dissolving status of hydrophilic substance, thereby impacting on the location sites of guest molecular interactions among the substances, rheology properties, and finally the release and penetration behavior in vitro. Adjusting the basic prescription was the key to obtain satisfactory percutaneous delivery and stability for LLC carrying multi-therapeutic agents.

Lopinavir Loaded Spray Dried Liposomes with Penetration Enhancers for Cytotoxic Activity.

HIV protease inhibitors (HIV-PI) are the drugs utilized for the treatment of HIV. However, their effectiveness is limited due to lack of bioavailability and they need to be coadministered with another drug. In this study single lopinavir (LPV) loaded phospholipid vesicles were prepared by the spray-drying method. The LPV-loaded spray-dried powder (L-SDP) was transformed into vesicles and then entrapped in a cream base with peppermint and olive oil. It is an Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) membrane fluidity study that is used to predict oil's effect on skin. The central composite design was used to optimize the L-SDP cream formulation. Ex-vivo drug release, skin deposition study, and cell proliferation assays were carried out using cancer cell lines of breast, lung, and skin melanoma. Analysis of DNA by flow cytometry on human breast cancer cell line MDA-MB-231 was carried out. The fluorescence microscopy, histopathological study, and in-vivo bioavailability studies were performed to measure the penetration and inertness of cream in animals. A membrane fluidity study revealed the effectiveness of oils as penetration enhancers. The L-SDP cream showed comparatively superior (%) drug deposition and permeability . Fluorescence images further confirm the penetration ability of the L-SDP cream which showed promising antiproliferative action on breast and lung cancer cells. The histopathological study demonstrates the inertness of cream while in-vivo bioavailability studies showed the many-fold increase in bioavailability of LPV. The liposomal drug delivery system of LPV has the potential to expose skin to systemic circulation and is useful for treating cancer.

Protein loading studies using polyelectrolyte microcapsules

In this study, PSS doped CaCO3 microparticles were used as sacrificial templates for the fabrication of hollow polyelectrolyte microcapsules. The lysozyme loading studies of two systems - chitosan/polymethacrylic acid (CHI/PMA) and chitosan/polystyrene sulfonate (CHI/PSS) microcapsules were carried out. The influences of feed and deposition pH on loading were investigated. Feed pH 8.8 showed more than 97% loading. The study suggests that loading of lysozyme depends upon both feed and deposition pH of the medium. The microcapsules were characterized by Attenuated Total Reflectance Fourier Transform Infrared spectrometer (ATR-FTIR), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and optical microscope.

A comparative study of oregano (Origanum vulgare L.) essential oil-based polycaprolactone nanocapsules/ microspheres: Preparation, physicochemical characterization, and storage stability

Essential oils have been used in clinical therapies and healing practices for several chronic diseases, but it is still challenging their extent use due to their poor stability. Nanotechnology delivery systems have been proposed as an alternative to improve their stability. Oregano (Origanum vulgare L.) is one of the most important medicinal plant highly reputed as an efficient remedy for infectious diseases. This study proposes the use of polycaprolactone, a biodegradable polymer, as a wall material for the encapsulation of Origanum vulgare L. essential oil, a carvacrol-rich source, using the nanoprecipitation and double emulsion methods. Nanocapsules formulations showed different values of mean particle size ranged between 175.17 ± 0.31 nm and 220.93 ± 2.73 nm, negative zeta potential values ranged between −18.7 ± 0.50 mV up to −42.53 ± 1.01 mV, and encapsulation efficiencies ranging from 50.36 ± 1.86% and 85.89 ± 2.40%. The optimized nano-formulation presented a nano-scale size of 181.6 ± 2.17 nm, a monomodal size distribution with a polydispersity index of 0.133 ± 0.01, a pH value of 4.92 and a zeta potential value of −40.9 ± 0.93 mV. The encapsulation efficiency of 85.89 ± 2.40% was achieved. In addition, microspheres produced by double emulsion, demonstrated porous microspheres morphology in the size of 1759.00 ± 162.6 nm, pH value of 5.98, a zeta potential value of −15.7 ± 1.56 mV and encapsulation efficiency of 47.52 ± 0.52%. Dynamic light scattering and scanning electron microscopy were performed to verify the size and the colloidal morphology. Thermal properties were assessed by thermogravimetric analysis and differential scanning calorimetry and the measurements revealed the thermal stability of the particles and showed that the crystalline state was less ordered in nanocapsules. Attenuated Total Reflectance Fourier Transform Infrared results indicated a slight shift in the CO band of the polymer from 1723 cm−1 induced by the change in its crystallinity degree due to the successful incorporation of oregano within its shell. Moreover, the long-term stability study was carried out for a period of 60 days at 4 ± 2 °C, 25 ± 2 °C and 40 ± 2 °C. Results showed that nanocapsules were physically stable with high carvacrol retention at different temperatures. However when microspheres were thermally treated at 25 °C and 40 °C, an increase in particle size was observed. Besides, carvacrol retention decreased to 64.56% and 61.84% at 25 °C and 40 °C, respectively. From gathered results, the good physical stability of nanocapsules in long-term storage with high carvacrol retention stability were observed mainly at 4 °C.

Infrared chemical mapping of degradation products in cross-sections from paintings and painted objects

Paintings and painted objects are quite susceptible to degradation, as paint layers are usually composed of complex mixtures of materials that can participate in chemical degradation processes. The identification of the constituent materials in paint (including binders, pigments, and fillers) and the degradation products within paint layers is of particular importance to ensuring the conservation of paintings, by providing important information both about their material history as well as their state of conservation. Metal fatty acid salts (metal soaps) are degradation products that can form in situ from interactions between inorganic pigments and free fatty acids in oil-based binding media, and can cause significant condition issues in paintings. Fourier transform infrared (FTIR) spectroscopy is one of the leading analytical techniques for the study of metal soaps. In this article, the materials analysis of several cross-sections from paintings and painted objects from works in Canadian collections is presented. Recent results on the use of external reflection FTIR (R-FTIR) spectroscopy to identify and map the distribution of paint components and metal soap degradation products is presented. In particular, zinc, lead, calcium, and copper fatty acid salts were all readily identified in paint cross-sections by R-FTIR spectroscopy, along with several pigments and the oil binding medium. The results shown here are among the first detailed examinations of these metal soaps in paint cross-sections using R-FTIR spectroscopy. The use of highly polished samples in which specular reflection is dominant allowed for spectral transformations to be applied to generate transmission/absorption-like spectra which facilitated identification of these species. The distribution of these species across the cross-sections was mapped by integrating characteristic absorption features in the R-FTIR spectra. Attenuated total internal reflection (ATR) FTIR spectroscopy was also performed on several samples, which provided additional compositional details at the interface of paint layers and degradation products.

Functionalized Poly(arylene ether nitrile) Porous Membrane with High Pb(II) Adsorption Performance.

Porous materials with high specific surface area possess a broad application prospect in the treatment of wastewater. In this work, sulfonated poly(arylene ether nitrile) (SPEN) functionalized with a carboxylic acid group was successfully synthesized, which was subsequently transformed into SPEN porous membranes with cetyltrimethyl ammonium bromide (CTAB) as pore-forming agents to study the adsorption performance for lead ions in aqueous solution. Then, experiments were conducted to investigate the effect of pH, contact time and initial solution concentration on the adsorption performance of porous membranes, and the adsorption capacities of porous membranes with different content (0, 5 and 15 wt %) of CTAB were 183.60, 161.73 and 127.43 mg/g, respectively, which manifested that the adsorption capacity decreased with the increase of CTAB. The adsorption capacities of porous membranes increased with the increase of the initial concentration of lead ions, and the maximum reached was 246.96 mg/g. The simulation of adsorption kinetics revealed that the adsorption was accorded with the pseudo-second-order kinetic model and Langmuir equation, indicating that the adsorption process followed Langmuir monolayer adsorption. Thermogravimetric analysis demonstrated that the porous membranes had excellent thermodynamic properties both before and after adsorption. In addition, the change of adsorption peak in the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) spectrum indicated that the absorption performance of porous membranes for lead ions benefited from the chelation between lead ions and the carboxylic acid group on SPEN. Moreover, the porous membranes maintained excellent adsorption properties after circulating five times under the conditions of acidic or alkaline, and the cycle regeneration effect was outstanding.

Prompt Screening of the Alterations in Biochemical and Mineral Profile of Wheat Plants Treated with Chromium Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy and X-ray Fluorescence Excited by Synchrotron Radiation

With mounting pressure of heavy metal pollution on agriculture, the demand of practical tools and protocols for nondestructive, pre-visual detection of plant response towards heavy metals has received great impetus. Advances in modern spectroscopic techniques such as synchrotron radiation X-ray fluorescence and attenuated total reflectance Fourier transform infrared spectroscopy have the capability of providing a complete picture of the metabolic events taking place in plants stressed with heavy metals without subjecting the sample to pre-processing. The present study explores the utility of synchrotron radiation X-ray fluorescence and attenuated total reflectance Fourier transform infrared spectroscopy along with multivariate analysis for the detection of the response as spectral indices of wheat seedlings towards chromium treatment. For this, wheat has been grown under optimized growth conditions and exposed to chromium at concentrations from 20 to 100 µM. The synchrotron radiation X-ray fluorescence spectra of control and chromium exposed seedlings show that exposure to chromium leads to its accumulation in the leaves of wheat seedlings which results in a reduction of the uptake of calcium, potassium, manganese iron, copper and zinc by the seedlings. The alterations in the biochemicals of wheat seedlings as a result of chromium exposure have been assessed by attenuated total reflectance Fourier transform infrared spectroscopy. Analysis of the infrared data reveals that chromium significantly alters the spectral signatures of cellulose, pectin, hemicelluloses, lignin, amide II, amide I and lipid in the leaves of wheat seedlings. The observed changes are dependent on the dose of chromium. The spectral signatures obtained in this study serve as important monitoring indices for observing alterations in the physiological, biochemical and metabolic status of plants under heavy metal stress.

Differentiation of locally manufactured Kajal by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy supported by chemometric analysis

Kajal, also known as Kohl (Arabic name) a cosmetic, is used for the beautificationof eyes and face as a whole. It can serve as an important corroborative evidence in various crimes against women and can also be used as a writing instrument to write the anonymous letters, threatening notes, suicide letters on a variety of substrates such as cotton cloth, tissue paper, tissue wipes, skin etc. 40 Kajal samples from 33 different brands were collected and analyzed using Attenuated Total Reflectance Fourier Transform Infrared (ATR FT-IR) Spectroscopy with advance statistical and computational tools. The present research investigated the application of this technique for the differentiation of locally manufactured Kajal based on the differences in the peak patterns, frequencies, and strengths of peak exhibited within the fingerprint region.The blind test was conducted with four unknown samples which were pretended to be unknown to the analyst and it was observed that all the unknown samples were predicted correctly with their respective classes. Effect of substrates and ageing were also studied under similar set of experimental conditions. This technique has been proven to be of high significance with complete non-destructive nature requiring minimal or no sample preparation and high repeatability.

Selenium conversion coating on AZ31 Mg alloy: A solution for improved corrosion rate and enhanced bio-adaptability

Among the various new generation medical implant materials, magnesium (Mg) and its alloys have drawn attention because of their biodegradability with non-toxicity and avoidance of revision surgery. The purpose of this work is to reduce the corrosion rate of AZ31 Mg alloy with selenium conversion coating and to enhance antibacterial activity and bio-adaptability. The corrosion rate has been greatly reduced and the localized corrosion behavior was analyzed to examine the possibility of pitting. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Raman IR spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results indicated that the coating consists of magnesium hydroxide, magnesium selenite and selenium. The topographical analysis with the scanning electron microscope and surface profilometer show that the surface consists of heterogenous agglomerated granules with increased surface roughness, which aided the apatite formation after immersion in Earle's solution for 7 days. The hydrogen evolution rate was reduced to ~0.021 ml cm−2 day−1 and selenium release from the coating was around 12 μg cm−2 day−1, which is lower than the daily requirement of humans. In addition, the coating shows better antibacterial and anti-biofilm formation activity.

Silk fibroin-derived polypeptides additives to promote hydroxyapatite nucleation in dense collagen hydrogels.

Silk fibroin-derived polypeptides (FDPs) are polypeptides resulting from the enzymatic separation of the hydrophobic crystalline (Cp) and hydrophilic electronegative amorphous (Cs) components of silk fibroin (SF). The role of these polypeptides in promoting the nucleation of hydroxyapatite (HA) has been previously investigated, yet is still not fully understood. Here we study the potential of HA mineralization via FDPs incorporated at 1:10, 1:2 and 1:1 in a plastically compressed (PC) and dense collagen (DC) scaffold. Scaffolds were immersed in simulated body fluid (SBF) at physiological conditions (pH = 7.4, 37°C) to promote biomineralization. The effect of Cs and Cp to promote HA nucleation was investigated at different time points, and compared to pure DC scaffolds. Characterization of Cs and Cp fragments using Liquid Chromatography–Mass Spectrometry (LCMS) showed little difference in the amino acid composition of the FDPs. Results obtained in vitro using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM) X-Ray Diffraction (XRD) and mass analysis showed little difference between scaffolds that incorporated Cs, Cp, and DC hydrogels. These results demonstrated that silk FDPs incorporation are not yet suitable to promote HA nucleation in vivo without further refining the collagen-FDP system.

Biosynthesis of Silver Nanoparticles Using Epilobium parviflorum Green Tea Extract: Analytical Applications to Colorimetric Detection of Hg2+ Ions and Reduction of Hazardous Organic Dyes

The present paper reports an unexplored simple, single step and cost effective green process for the preparation of highly stable silver nanoparticles (AgNPs) using Epilobium parviflorum (EP) extract and investigates their catalytic activity towards hazardous organic dyes, congo red (CR), rhodamine B (RhB), methyl orange (MO), methyl red (MR), and colorimetric sensing ability for Hg2+ ions in solutions. Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR–FTIR) studies confirmed the capping and stabilization of the AgNPs by EP extract. X-ray diffraction (XRD) pattern showed face centered cubic structure for the AgNPs. Transmission electron microscopy (TEM) validated that the AgNPs are spherical in shape with narrow size distribution of 5.59 ± 1.12 nm. The results indicate that regardless of their good linear dynamic range (0.5–5.0 µM), detection limit (58.11 nM, 11.62 ppb) and selectivity for the accurate determination of Hg2+ ions, the AgNPs can be attractive choices for wastewater management systems.

Tannin: A natural corrosion inhibitor for aluminum alloys

This work aims at investigating the effect of tannin, a natural compound, as corrosion inhibitor for bare and coated aluminum alloys (AA1200). Tannin was characterized by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (FTIR-ATR) and its interaction with the sample surface was evaluated by computational calculations using the density functional theory (DFT) and electrochemical measurements. The corrosion behavior was studied by open circuit potential (EOCP), electrochemical impedance spectroscopy (EIS) and by the scanning vibrating electrode technique (SVET). Complementary studies were performed by scanning electron microscopy (SEM). Results demonstrated that tannin is an effective corrosion inhibitor protecting both coated and uncoated aluminum samples.

Coordination polymer-derived CuO catalysts for oxidative degradation of methylene blue

Coordination polymers (CP) are a new class of hybrid materials consisting of metal clusters connected by organic ligands and forming structures along one, two or three dimensions. Three Cu2+ coordination polymers Cu(1,3-BDC).3H2O, Cu(1,4-BDC), and Cu(5-NH2-1,3-BDC) (BDC = benzenedicarboxylic) were prepared via an electrochemical method and used as precursors for CuO by calcination in air at 650 °C. All the prepared samples were characterized by Powder X-ray Diffraction (PXRD), Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), Thermal Analysis (TGA-DTA), and Scanning Electron Microscopy (SEM). The results confirmed both the crystallization of the CPs and the formation of copper oxide after the thermal treatment. The CP-derived CuO was tested in the catalytic degradation of the methylene blue in the presence of H2O2, and the effect of reaction parameters such as the mass of catalyst and volume of H2O2 were studied. Cu(1,4-BDC)-derived CuO catalyst showed discoloration efficiency about 92% at 308 K, and 100% at 331 K after 120 and 30 min, respectively with good recyclability up to the four cycles (71.77%).

Antibacterial behaviour of surface modified composite polyamide nanofiltration (NF) membrane by immobilizing Ag-doped TiO2 nanoparticles

ABSTRACT Modification of active membrane surface is an auspicious way to enhance the membrane performance. In our study, a commercially available composite polyamide Nanofiltration (NF) membrane was modified by immobilizing silver doped TiO2 (Ag–TiO2) nanoparticles. Ag–TiO2 with different nanoparticles concentration (0.05, 0.1, and 0.5 wt. %) were coated on the surface of the membrane by a dip coating method. The evidence of successful coating was evaluated by Scanning Electron Microscopy coupled with Energy Dispersive Spectroscopy and Atomic Force Microscopy images. Moreover, the Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), contact angle measurement and permeation tests were carried out in order to evaluate the membrane performance after coating. The antifouling property of the modified membrane was evaluated for Gram-positive (Bacillus subtilis) and Gram-negative (Escherichia coli) bacteria by colony counting method. The results indicated that the modified membranes keep efficient antibacterial efficacy against both types of bacteria. The bacterial growth reduced approximately 93% and 91% on the modified membrane as compared to the unmodified membrane for E.coli and B.subtilis, respectively. Ag–TiO2 nanoparticles imbedded nanofiltration membranes inhibit the biofilm formation and facilitate in cleaning membrane surface without using excessive chemical agents.

Determination of trace amounts with ATR FTIR spectroscopy and chemometrics: 5-(hydroxymethyl)furfural in honey

The feasibility of Attenuated Total Reflectance Fourier Transform Infrared (ATR FTIR) spectroscopy and chemometric modeling for analysis of trace compounds is studied on the example of 5-(hydroxymethyl)furfural (HMF) in honey up to a concentration of 110 ppm, and compared to results in literature. Randomized repeated measurements of the calibration samples were carried out to prevent analytical artifacts. A partial least squares (PLS) model was calculated for quantitative determination. The considered spectral range has significant influence on the PLS model. Furthermore, averaging of spectra can improve the model quality due to the elimination of statistical noise. A low root mean square error of prediction (RMSEP) of 13 ppm was achieved. Hence, the results indicate that trace compound determination with ATR FTIR spectroscopy is possible, although calibration and modeling efforts are higher compared to standard applications of ATR FTIR spectroscopy and chemometrics.

Real time FTIR spectroscopy of tissue smears from gynecologic cancer tissues: A preliminary study.

e17089 Background: Women with suspected Gynecologic cancer undergo surgical procedures during which tissue from suspected areas is excised. Fast histopathology analysis is performed intra-operatively using frozen section (FS) analysis, results of which are available within less than an hour. However, the accuracy of the FS test ranges between 75% and 100% when compared to final histopathology diagnoses. Fourier transform Infrared (FTIR) spectroscopy, utilized for classification of tissue samples into malignant and benign tumors, has shown comparable results to those of FS histopathology analysis. However, the sample preparation time and the effects of tissue preparation on the measured spectra have been a concern for the utilization of this technique in clinical practice. In this study we used attenuated total reflection (ATR) FTIR spectroscopy to examine fresh tissue impression smears as an alternative to the FS technique for rapid classification of tissue samples obtained during surgery. Methods: The study was approved by relevant ethics committees and was conducted in accordance with the Declaration of Helsinki. All patients provided written, informed consent. In total, 23 biopsies (ovarian and uterine) were extracted from suspected tumor sites during surgical procedures and sent to the histopathology laboratory for both pathological and FTIR analyses. Results of the histopathology analysis classified 15 samples as benign and 8 samples as malignant. Prior to the histopathologic analysis, tissue samples from these tumors were lightly pressed against the surface of an ATR crystal, leaving on its' surface impression smears. These smears were air dried for ~5 minutes. Mid-IR absorbance spectra were collected using an ATR-FTIR spectrometer. Machine learning techniques (PCA-LDA and SVM) were utilized to build discrimination models from the absorbance data of the measured smears. Sensitivity and specificity were calculated. Results: IR absorbance spectra of malignant smears were consistently higher from spectra of benign smears in the 850cm-1 to 1450 cm-1 range and they were consistently lower in the 3200cm-1 to 3600cm-1 range. The PCA-LDA discrimination model correctly classified the samples with a sensitivity and specificity of 100%, and the SVM showed a training accuracy of 100% and a cross validation accuracy of 91.3%. Conclusions: These preliminary results suggest that ATR-FTIR spectroscopy of tissue smears may have an important role in the development of next-generation techniques for intra-operative tumor classification.

Performance of magnesia-modified sodium carbonate-activated slag/fly ash concrete

Various innovative research in the cement industry is looking into improving its environmental sustainability. Sodium carbonate-activated slag/fly ash (NC-SF) binders has recently evolved as a potentially more sustainable binding materials than both Portland cement and conventional alkali activated materials such as sodium silicate and sodium hydroxide activated materials. The reaction mechanism and some microstructural properties of NC-SF cements have been a major area of research recently. However, very few studies have scaled up the investigation of these binders into concrete specimens. This paper, therefore, provides new insight into the strength development and the durability performance of NC-SF concrete and MgO-modified NC-SF concrete. Concrete testing included measurements of compressive strength, split tensile strength, water absorption, depth of carbonation, sulphate exposure, acid exposure and elevated-temperature exposure. Microstructure studies were conducted using Powder X-Ray diffraction (PXRD), Thermogravimetric analysis (TGA) and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR). It is concluded that NC-SF concrete mixes develop acceptable mechanical strength and demonstrate high resistance to sulphate attack. They also showed higher resistance to acid attack than the control mix based on sodium silicate-activated slag concrete. Here, emphasis is placed on the potential of developing NC-SF concrete with excellent performance and less complicated production methods as well as a low carbon footprint. It is also found that the use of reactive MgO enhanced the strength development of NC-SF concrete as well as its resistance to acid and carbonation.