Spectroscopic Evaluation Research Articles

Mechanism of protein biofilm formation on Ag-DLC films prepared for application in joint implants

Silver-doped diamond-like carbon (Ag-DLC) films offer low residual stress, good adhesion, and excellent wear resistance, and thus are promising materials for surface modification of joint prostheses. Further, as proteins are the most abundant component of joint fluid, the wear performance of Ag-DLC films in protein environments warrants investigation. We prepared DLC and 10.0 at.% Ag-DLC films using hybrid deposition technique by combining high-power pulsed magnetron sputtering and high-power pulsed plasma-enhanced chemical vapor deposition. The wear performance of the films was tested using bovine serum albumin (BSA) solution. A biofilm of denatured proteins formed at the friction interface of the Ag-DLC film, which improve wear resistance. Subsequent protein adsorption, Ag+ ions release, and spectroscopic evaluation of the interaction between Ag+ ions and BSA molecules revealed the mechanism of biofilm formation. Ag doping promoted the protein adsorption on film surface and friction interface of Ag-DLC films. Meanwhile, Ag-DLC films released Ag+ ions when exposed in physiological solutions. The released Ag+ ions break the hydrogen bonds and disulfide bonds in proteins and transform the α-helix structure to β-sheet and β-turn structure, thus unfolding the protein, exposing the inner hydrophobic groups, and inducing protein deposition and biofilm formation. The study elucidates the biofilm formation mechanism at the friction interface of Ag-DLC films and counterparts and can aid in design of hardwearing joint implants.

Magnetic resonance imaging and spectroscopy in evaluation of hypoxic ischemic encephalopathy in pediatric age group

BackgroundHypoxic ischemic encephalopathy is a major cause of pediatric mortality and morbidity, with possible long-term neurologic sequel, such as cerebral palsy. With improvements in care of at-risk neonates, more children survive. This makes it increasingly important to assess, soon after birth, the prognosis of children with hypoxic-ischemic encephalopathy. The aim of the study was to assess the additive role of magnetic resonance spectroscopy over conventional MRI in diagnosis and early prediction of pathological motor development in neonates with hypoxic ischemic encephalopathy.ResultsMRS ratios showed significant difference between unfavorable and normal outcome infants. MRS ratios as Lac/Cr, NAA/Cr and NAA/Cho within basal ganglia, thalamus and white matter can significantly differentiate between patients with normal and pathological outcome at 1 year.Lac/Cr positively correlates with the severity of HIE. Both NAA/Cr and NAA/Cho negatively correlate with the severity of the disease. Ratios cutoff values as Lac/Cr above 0.38 and 0.42 in basal ganglia and white matter, respectively, NAA/Cr below 0.9 and 0.8 in basal ganglia and occipital white matter, respectively, and NAA/Cho below 0.29 and 0.31 in basal ganglia and frontal white matter, respectively, were significantly predictive of pathological outcome.ConclusionHigh Lac/Cr, low NAA/Cr and low NAA/Cho ratios within examined regions of the brain including deep grey matter nuclei as well as white matter are associated with an adverse outcome in infants with perinatal asphyxia. MRS is an accurate quantitative MR biomarker within the neonatal period for prediction of neurodevelopmental outcome after perinatal HIE. MRS may be useful in early clinical management decisions, and counseling parents thereby ensuring appropriate early intervention and rehabilitation.

A perspective on alloy effects between polymer additives in the development of nondust blends: A DSC and spectroscopic evaluation

AbstractThe optimum synergistic melt blending of 18 antioxidants and light stabilizers has been evaluated using differential scanning calorimetry (DSC) analysis and melting point phase plots obtained to evaluate any effective true eutectic mixtures. Although only three systems gave true eutectic mixtures, optimum lower temperature melt blends were possible up to 230°C. Systems with Lowilite 26 and Cyasorb 1164 showed effective eutectic mixtures especially with hindered piperidine stabilizers while those based on Anox 20 and Lowilite 62 were poor. Eutectic mixtures between aromatic phenolics and amines infer that they are not simply a mechanical mixture of the two components, but a preferential ordering of atomic planes occurs during their formation associated with intermolecular hydrogen bonding. Fourier transform infra‐red spectroscopy (FTIR) and ultra‐violet (UV) absorption analysis showed in some cases strong bonding interactions between some of the additives where hydroxyl, amine, and carbonyl groups can potentially interact. This was especially notable where strong eutectic behavior was observed for benzophenone absorbers, where alkoxy substitution (Lowilite 22) was replaced by hydroxyl groups (Lowilite 24). Strong interaction between hindered piperidine and phenolic antioxidants also gave effective eutectic lattice phases. The analysis is discussed in relation to potential outcomes for the use of additive melt blends in polymer stabilization.

Synthesis, spectroscopic and biological activity evaluation of Ni(II), Cu(II) and Zn(II) complexes of schiff base derived from pyridoxal and 4-fluorobenzohydrazide

A novel Schiff base ligand, 4-fluoro-N-((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)benzohydrazide (PLFBH) was synthesized by condensationof pyridoxal and 4-fluorobenzohydrazide. Its complexes with Ni(II), Cu(II), and Zn(II) metal ionswere prepared and characterized by spectroscopic IR, 1H-NMR, UV, LC-MS, ESR, and powder XRD studies and by elemental analysis and thermal analysis, molar conductance, and magnetic susceptibility measurements. The results indicate the geometry of the complexes to be hexa coordinate distorted octahedral. Based on the electronic absorption and fluorescence emission spectra and viscosity studies, an intercalative mode of binding of the complexes with CT-DNA was suggested, which was also supported by DNA docking studies. The docking studies of metal complexes with DNA were carried out using Autodock 4.2. The in vitro anticancer assay for the Cu(II)-PLFBH complex was performed to assess the ability of the complex to inhibit human cell proliferation on HeLa human cervical carcinoma cells, MCF-7 human breast carcinoma cells, and A549 human lung carcinoma cells. The Cu(II)-PLFBH complex exhibited moderate to good inhibitory effect on the cancer cell lines studied. The complexes showed good cleavageability toward plasmid pBR322 DNA. The metal complexes were found to show good antibacterial activity against gram positive bacteria, Staphylococcus aureus and Bacillus cereus and gram negative bacteria Escherichia coli and Pseudomonas aeruginosa cultures,while the ligand showed marginal activity. Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1961271 .

Structural and spectroscopic analysis and evaluation of cytotoxic activity of 2-hydroxychalcones against human cancer cell lines

Chalcones and their derivatives exhibit a broad spectrum of pharmacological activities, including antiproliferative activities. Accordingly, they are deemed robust anticancer candidates for cytotoxicity assays. Herein, we synthesized and characterized four chalcones using nuclear magnetic resonance (1H NMR and 13C NMR), Fourier transform Raman (FT-Raman), attenuated total reflection Fourier transform infrared (ATR-FTIR), and ultraviolet-visible (UV–vis) spectroscopy. Theoretical calculations of quantum chemistry were performed to obtain data regarding normal vibration modes, frontier molecular orbitals, molecular electrostatic potential maps, theoretical UV–vis spectra, and quantum chemical parameters expected for these chalcones. In addition, we evaluated the cytotoxic potential of these compounds. For synthesized compounds, quantum chemical calculations demonstrated excellent correlation with experimental data. The electronic properties revealed that chalcones 1 and 4 possess a higher electrophilic character, while chalcones 2 and 3 possess a higher nucleophilic character. Chalcone 3 demonstrated the highest value of HOMO energy, indicating the greatest propensity to donate electronic density among the four compounds. According to the HOMO-LUMO energy gap and global hardness, the reactivity of chalcones should follow the order 1 < 2 < 4 < 3. Regarding the cytotoxic potential, chalcones 1 and 4 exhibited superior activity against HL-60 acute promyelocytic leukemia cells (IC50 = 14.09 ± 1.001 and 28.02 ± 1.47 µM, respectively) and HCT-116 colon cancer cells (IC50 = 22.64 ± 0.64 and 42.74 ± 4.63 µM, respectively).

What is alanine adipate, in fact?

We show that a recently published paper “Spectroscopic evaluation of Alanine Adipate nonlinear optical materials growth dynamics: Mechanical and thermal optimization” (S. Akilandeswari, L. Jothi, J. Mol. Struct. 1240 (2021) 130577) is completely erroneous. A so-called “alanine adipate” actually is adipic acid, which is centrosymmetric and therefore cannot be a nonlinear optical crystal showing second harmonic activity.

Comparative spectroscopic analysis, performance and emissions evaluation of Madhuca longifolia and Jatropha curcas produced biodiesel.

In order to fulfil the growing need to replace fossil fuels, investigations exploring the production of biodiesel from agricultural biomass have gained attention. In this study, biodiesels were produced from Madhuca longifolia and Jatropha curcas by means of pre-treatment followed by a two-step acid-base homogeneous catalyst method. These biodiesels were blended with diesel at different percentages. The efficacy of the process was examined using various characterization methods while the efficiency of the produced biodiesels was examined by their engine performance and emission tests. Both Madhuca and Jatropha-based biodiesels exhibited physiochemical properties like that of diesel. Biodiesels were produced by pre-treating with orthophosphoric acid and toluene. The second step involves acid esterification, followed by base transesterification. Raman spectra exhibited C=O stretching at 1725 cm-1 indicating conversion of Madhuca and Jatropha oil into biodiesel. Fourier transform infrared spectroscopy showed a strong presence of fatty acid profile and triglyceride ester linkage at 1744 cm-1. Ultraviolet-visible (UV) spectra confirmed the presence of conjugated dienes in the extracted biodiesels. UV absorbance at 320 nm decreased linearly with blend percentage. 1H and 13C nuclear magnetic resonance (NMR) confirmed the presence of methyl ester moiety at 3.6 δ (ppm) and methoxy carbon at 51.2 δ in biodiesel, distinguishing it from diesel. In the engine performance tests, the variations of brake specific fuel consumption, exhaust gas temperature and brake thermal efficiency versus brake power were studied. The emission tests of different blends were done in terms of carbon monoxide, nitrous oxide and unburnt hydrocarbon. The Jatropha biodiesel exhibited lower mean brake specific fuel consumption, exhaust gas temperature, emitted less carbon monoxide and unburnt hydrocarbon than Madhuca biodiesel. The average decrease in brake thermal efficiency was more in Jatropha biodiesel than Madhuca biodiesel. The present work uses for the first time treatment of ortho phosphoric acid and toluene to produce biodiesel followed by a two-step homogeneous acid-base catalyst method, drastically reducing free fatty acid value.

Facile fabrication and structural elucidation of lignin based macromolecular green composites for multifunctional applications

AbstractThe present work deals with the preparation and characterization of lignin based macromolecular polymeric composites and applications thereof. Here lignin is complexed with pectin and/ or gellan gum, to form two different macromolecular green composites LP and LPG. The best ratios screened out through evaluation of nanoparticle characterization and rheology, then confirmed by surface morphology. The superior thermal stability is proved by DSC analysis. The reaction groups involving in complexation are confirmed by FT‐IR spectroscopic evaluation where the methoxy or methyl group of lignin interacts with the hydroxyl group of pectin and gellan gum to form nanocomposites. The reduced particle size and surface charge confirm the complexation due to interaction between ionizable functional groups. The applications of these composites are validated by their dye adsorption capacity and anti‐microbial properties (after loading of green silver nanoparticles) which proves the multifunctional properties of novel composites. The maximum dye removal efficiency of both composites is independent of initial dye concentration. Dye adsorption capacity is best fitted by Freundlich adsorption isotherms that follow pseudo‐second‐order adsorption kinetics. The antibacterial study of developed silver nanoparticle loaded and unloaded composites shows wide spectrum activity against E. coli and S. aureus, with higher inhibition efficiency against gram‐negative organism.

Application of Magnetic Resonance Imaging in the Evaluation of Nutritional Status: A Literature Review with Focus on Dialysis Patients.

Magnetic resonance imaging (MRI) is indispensable in clinical medicine for the morphological and tomographic evaluation of many parenchymal organs. With varied imaging methods, diverse biological information, such as the perfusion volume and measurements of metabolic products, can be obtained. In addition to conventional MRI for morphological assessment, diffusion-weighted MRI/diffusion tensor imaging is used to evaluate white matter structures in the brain; arterial spin labeling is used for cerebral blood flow evaluation; magnetic resonance elastography for fatty liver and cirrhosis evaluation; magnetic resonance spectroscopy for evaluation of metabolites in specific regions of the brain; and blood oxygenation level-dependent imaging for neurological exploration of eating behavior, obesity, and food perception. This range of applications will continue to expand in the future. Nutritional science is a multidisciplinary and all-inclusive field of research; therefore, there are many different applications of MRI. We present a literature review of MRI techniques that can be used to evaluate the nutritional status, particularly in patients on dialysis. We used MEDLINE as the information source, conducted a keyword search in PubMed, and found that, as a nutritional evaluation method, MRI has been used frequently to comprehensively and quantitatively evaluate muscle mass for the determination of body composition.

A Review on High Performance Liquid Chromatographic Methods for the Determination of Metformin

Background: The presence of pharmaceuticals (PACs) drugs in the environment and their detection and quantification have emerged as one of the challenging issues for the scientific community. Introduction: The gold standard, an anti-diabetic drug, Metformin has a strong potential to contaminate the aquatic bodies, being a highly polar drug. Different analytical methods based on spectroscopic evaluation or chromatographic techniques have been developed to find out the concentration of drug/ their metabolites. Methods: This review article discussed the chromatographic techniques for analysis of Metformin (in ng/L to μg/L) in aqueous samples, pharmaceutical drugs and biological fluids such as urine and human plasma are High-Performance Liquid Chromatography (HPLC), Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC), High-Performance Thin-layer Chromatography (HPTLC), Hydrophilic Interaction Liquid Chromatography HILIC–MS/MS, Liquid Chromatographic–tandem mass spectrometric (LC-MS-MS), Ultra-High Performance Liquid Chromatography (UPLC). Result: The relevance modifications of traditional HPLC methods for separation of the mixture of drugs with a focus on the lesser time, better resolution, sensitivity, symmetry of peaks, the limit of detection and accuracy of the results has been envisaged through research findings. Hydrophilic interaction liquid chromatography (HILIC) – tandem mass spectrometry method offered the possible solution for highly polar drugs detection and quantification in effluent and surface water samples. Conclusion: HPLC based analytical techniques offer the advantages viz. less time requirement, minimum usage of organic solvents and better separation and quantification of Metformin. The futuristic research approach lies in the development of newer extraction strategies, mobile phases and adsorbent materials for the HPLC based separations.

Ovarian stimulation drugs alter the metabolite content of the growing follicle: in vivo spectroscopic evaluation of follicle fluid

Objective: To determine and compare metabolite content using magnetic resonance spectroscopy (MRS) of growing follicles in patients with polycystic ovary syndrome (PCOS) receiving recombinant follicle stimulating hormone (rFSH), clomiphene citrate (CC) or aromatase inhibitor (AI) for ovarian stimulation.Material and Methods: Thirty patients diagnosed with PCOS and infertility and scheduled for ovarian stimulation were divided by therapy, rFSH/CC/AI, into three equal groups. Five fertile cases were designated as the control group. When the follicle diameters reached 16-18 mm in each group, patients underwent MRS and the metabolite content of a dominant follicle was analyzed. N-acetylaspartate, lactate (Lac), creatine (Cr), and choline (Cho) metabolite levels in parts per million were measured in the spectra.Results: A ~three-fold decrease in dominant follicle Cho content was found in patients receiving CC compared to control subjects. Similarly, the dominant follicle Cho intensities of patients given rFSH and AI were noted to be significantly higher than those who received CC. Only dominant follicle Lac levels of the patients who received CC were found to be significantly higher than the other groups. Cr peak intensities of patients receiving CC were found to be approximately three times less than control subjects. Cr signal intensity was significantly higher in patients receiving rFSH or AI than in patients receiving CC. While two patients became pregnant in the CC group, three patients in the AI group and five patients in the rFSH group became pregnant. The main metabolites detected in patients who conceived in each group were Cho and Cr. In cases who could not conceive, while Lac and lipid signals increased, Cho and Cr signals decreased.Conclusion: Unlike CC, ovarian stimulation with rFSH or AI does not alter dominant follicle metabolite content. The developmental capacity of a growing egg may be determined non-invasively with MRS.

In vitro antioxidant assay guided ex vivo investigation of cytotoxic effect of phytosomes assimilating taxifolin rich fraction of Cedrus deodara bark extract on human breast cancer cell lines (MCF7)

ObjectiveCharacterization, in vitro evaluation of antioxidant activity and ex vivo investigation of cytotoxic effect of phytosomes assimilating ethyl acetate fraction fractionated from hydro alcoholic extract of Cedrus deodara bark. MethodSolvent fractions of hydro alcoholic extract were analyzed by HPTLC to identify taxifolin, using toluene: ethyl acetate: formic acid (04:38:06) as mobile phase. Phytosomes of ethyl acetate fraction were prepared with antisolvent precipitation method and characterized by particle size analysis, entrapment efficiency, DSC, IR spectroscopy and partition coefficient. Phytosomes were screened for in vitro antioxidant activity and concentration exhibiting highest antioxidant activity was reinforced ahead for evaluation of ex vivo anticancer investigation by MTT assay and TB assay using MCF7 cell lines. ResultOwing to identification of taxifolin (Rf=0.61) in ethyl acetate fraction during HPTLC, it was utilized further for complexation. Oval shape, particle size (544 nm), zeta potential (−28.1) and polydispersity index (0.141) of PC3 phytosomes concluded about characterization of the complex. Entrapment efficiency (75.40 ± 0.53%) and partition coefficient (0.89 ± 0.91) of PC3 phytosomes was higher as compared to PC1 and PC2 complex, therefore, PC3 was evaluated for ex vivo studies after DSC and infrared spectroscopic evaluation. PC3 phytosomes (100 mg/mL) exhibited highest antioxidant activity (P < 0.001) and reduced IC50 value, as compared to ethyl acetate fraction and standard. Further on ex vivo investigation, it also showed enhancement in cytotoxic activity (P < 0.001) in contrast to ethyl acetate fraction. ConclusionPresent study reveals about in vitro antioxidant assay guided ex vivo investigation of cytotoxic effect of ethyl acetate fraction and phytosomes of taxifolin-rich fraction extracted from Cedrus deodara bark.

Spectroscopic evaluation of vibrational temperature and electron density in reduced pressure radio frequency nitrogen plasma

The optical emission spectroscopy technique is used to determine the vibrational temperature of the second positive band system, N_{2} (C,upsilon^{^{prime}} - B,upsilon^{^{primeprime}}) in the wavelength range 367.1–380.5 nm by using the line-ratio and Boltzmann plot methods. The electron temperature is evaluated from the intensity ratio of the selected molecular bands corresponding to N_{2}^{ + } (B,upsilon - X, upsilon^{^{prime}} , 391.44 nm), and, N_{2} (C,upsilon^{^{prime}} - B,upsilon^{^{primeprime}}, 375.4 nm) transitions, respectively. The selected bands have a different threshold of excitation energies and thus serve as a sensitive indicator of the electron energy distribution function (EEDF). The electron density has been determined from the intensity ratio of the molecular transitions corresponding to N_{2}^{ + } (B,upsilon - X, upsilon^{^{prime}} , 391.44 nm), and, N_{2} (C,upsilon^{^{prime}} - B,upsilon^{^{primeprime}}, 380.5 nm) for different levels of pressure and radio frequency power. The results show that the vibrational temperature decreases with increasing nitrogen fill pressure and radio frequency power. However, the electron temperature increases with radio frequency power and reduces with fill pressure. The electron density increases both with nitrogen fill pressure and radio frequency power that attributes to the effective collisional transfer of energy producing electron impact ionization. Plasma parameters show a significant dependence on discharge conditions and can be fine-tuned for specific surface treatments.Article HighlightsSpectrum analysis of RF-driven nitrogen plasma for varying discharge conditionsEvaluation of vibrational temperature using line-ratio and Boltzmann plot methodsComparison of vibrational temperatures for line-ratio and Boltzmann plot methodsEvaluation of electron temperature and density using the intensity-ratio of bandsCorrelation of temperature and density with varying fill pressure and RF power

Spectroscopic evaluation of Alanine Adipate nonlinear optical materials growth dynamics: Mechanical and thermal optimization

Semi organic nonlinear optical material of alanine adipate (AA) was grown by slow evaporation solution method using ethanol as a solvent. The synthesized material was subjected to various characterization techniques. The single crystal X-ray diffraction analysis was carried out and their lattice parameters were determined. The presence of various functional groups of AA and their vibrational modes were identified from Fourier transform infrared (FTIR). FT-Raman spectral study has been performed to confirm the functional groups. The optical transmittance of the material was identified from UV–VIS-NIR studies. and the optical energy gap of AA is determined as 4. 851 eV. Fluorescence spectrum was also carried out using spectrofluorometer and the emission peak was observed at 454. 48 nm confirming the blue emission of the prepared crystals. The mechanical property of the grown crystal was studied using Vicker's micro hardness tester and the mechanical parameter values are calculated. Mechanical measurement indicates that the grown crystal belongs to softer category. Thermal properties of AA were evaluated with thermogravimetric analysis, differential thermal analysis and differential scanning calorimetry. The second harmonic generation efficiency was found to be 1.06 higher than that of standard potassium dihydrogen orthophosphate (KDP).

Elucidation of in-situ produced organic matrix effect on the solar photo/photocatalytic inactivation of E. coli

Solar photoinactivation and photocatalytic inactivation of E. coli in aqueous solution was investigated in various matrix conditions in the presence/absence of humic acid as representative of natural organic matter and inorganic components focusing on the spectroscopic evaluation of in-situ produced organic matrix. Characterization of organic matter with respect to E. coli inactivation under various experimental conditions was followed by the elucidation of specified UV–vis and fluorescence parameters as well as dissolved organic carbon content. Solar light initiated destruction of bacterial cells via lysis were visualized by the occurrence of protein-like fluorophores and fluorophores of microbial by-products as presented in excitation emission matrix fluorescence contour plots indicating a variety of changes in their shape and intensity with respect to increasing irradiation periods. Moreover, under similar experimental conditions, in the presence of humic matter these fluorophores were mainly quenched by humic-like fluorophores.E. coli inactivation kinetics obeyed first order kinetic model for both solar photoinactivation and photocatalytic inactivation conditions. Rate constants for photoinactivation of E.coli ranged from 0.184 to 0.0920 min−1, whereas photocatalytic inactivation rate constants varied from 0.248 to 0.0488 min−1. Both humic acid and water matrix components had inhibitory effects on inactivation efficiency which could be attributed to competitive reactions occurring between humic matter, bacterial cells, and bacteria derived organic material. Further evaluation of bacteria inactivation was followed by detection of organic (protein and carbohydrate) and inorganic (K+ leakage) constituents under specified conditions in correlation to the spectroscopic parameters.

Spectroscopic evaluation of carcinogenesis in endometrial cancer

Carcinogenesis is a multifaceted process of cancer formation. The transformation of normal cells into cancerous ones may be difficult to determine at a very early stage. Therefore, methods enabling identification of initial changes caused by cancer require novel approaches. Although physical spectroscopic methods such as FT-Raman and Fourier Transform InfraRed (FTIR) are used to detect chemical changes in cancer tissues, their potential has not been investigated with respect to carcinogenesis. The study aimed to evaluate the usefulness of FT-Raman and FTIR spectroscopy as diagnostic methods of endometrial cancer carcinogenesis. The results indicated development of endometrial cancer was accompanied with chemical changes in nucleic acid, amide I and lipids in Raman spectra. FTIR spectra showed that tissues with development of carcinogenesis were characterized by changes in carbohydrates and amides vibrations. Principal component analysis and hierarchical cluster analysis of Raman spectra demonstrated similarity of tissues with cancer cells and lesions considered precursor of cancer (complex atypical hyperplasia), however they differed from the control samples. Pearson correlation test showed correlation between cancer and complex atypical hyperplasia tissues and between non-cancerous tissue samples. The results of the study indicate that Raman spectroscopy is more effective in assessing the development of carcinogenesis in endometrial cancer than FTIR.

Photocatalytic Bactericidal Performance of LaFeO3 under Solar Light: Kinetics, Spectroscopic and Mechanistic Evaluation

Lanthanum orthoferrites are a versatile class of catalysts. Here, the photocatalytic bactericidal performance of LaFeO3 (LF) to inactivate pathogenic microorganisms, i.e., Escherichia coli (E. coli), in water under simulated solar irradiation conditions was investigated. Various competing and contributing factors were covered to visualize the reaction medium consisting of E. coli K12 cells, organic sub-fractions formed by cell destruction, and LF surface. LF solar photocatalytic inactivation (SPCI) kinetics revealed the highest inactivation rate in ultrapure water as expected, followed by distilled water (DW), aqueous solution containing anions and cations (WM) and saline solution (SS). Characterization of the released organic matter was achieved by UV-vis and fluorescence spectroscopic techniques as well as organic carbon contents (DOC). Upon SPCI, significant amounts of K+ along with released protein contents were detected expressing cell wall destruction and lysis. Under the specified experimental conditions, in the presence of released intracellular organic and inorganic components via cell lysis, a significant count of E. coli was still present in SS, whereas almost all bacteria were removed in other matrices due to various challenging reasons. Based on the presented data, SPCI of E. coli using LF as a novel photocatalyst was successfully demonstrated as an alternative and promising method for disinfection purposes.

Abstract PS1-38: Role of MR spectroscopy in evaluation of axilla in breast cancer

Abstract The role of surgery for women with breast cancer presenting with clinically negative axilla is being questioned. Trials are underway to evaluate axillary ultrasound (AUS) for non-invasive evaluation of axilla instead of sentinel node biopsy. However, AUS has a sensitivity of 50-59%. Thus, there is a need for non-invasive test to complement AUS. MR Spectoroscopy (MRS) identifies metabolites, viz. glycerophosphocholine (GPC), phosphocholine (PC), threonine (Thr), lactate (Lac), Choline (Cho) etc that are associated with presence of metastasis in axillary lymph nodes (LN) . Biochemical changes in tumor infiltrated LNs occur earlier than morphological changes and MRS can detect these chemical changes, it can be a useful investigation in evaluation of axilla. Aim: To evaluate the role of MR Spectroscopy (MRS) in identifying biochemical changes in axillary lymph nodes in breast cancer and correlate the findings with Histopathology (HP) to predict presence of metastasis.Methods: Axillary lymph nodes were obtained from 59 patients with early breast cancer with clinically negative axilla who underwent surgery. Each LN was bisected into two equal halves. One half of LN was snap frozen in liquid nitrogen (-196°C) and then stored at −80°C until perchloric acid extraction was carried out. Other half of LN was subjected to HP evaluation with standard Eosin and Hematoxylin staining . METHOD OF MR Spectroscopy: Water-soluble metabolites from the tissue samples were extracted using PCA extraction procedure (Seenu et al Magn Reson Imaging 2005 doi: 10.1016/j.mri.2005.10.004). Proton (1H) NMR spectroscopy of specimen was performed. Concentrations of GPC, PC, Thr, Lac, Cho and other metabolites were determined by comparing the integrated intensity of isolated resonances of the compounds of interest with that of the TSP signal, correcting for the number of contributing protons and with the tissue weight . Intensity ratio for metabolites, GPC, PC and Thr (GPC+PC/Thr) was also determined.Statistical Analyses: Levels of concentrations of various metabolites were compared between involved and non-involved lymph nodes using Wilcoxon rank sum test. Diagnostic indices of MRS were assessed in terms of sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratios and overall accuracy taking final histopathology as ‘gold standard’ with 95% confidence intervals.Results: Mean concentrations of GPC, PC and Thr were significantly increased in involved as compared to non-involved node (table 1). Cho and Lac were not significantly increased. A cut-off value of 0.80 for the GPC-PC/Thr ratio was chosen to obtain a maximum accuracy of 89% based on previous study. MRS accurately predicted metastasis in 21 of the 24 patients who had LN metastasis on HP. Out of 35 patients with no LN metastasis, MRS correlated accurately with HP in 30 of them. Sensitivity, specificity, PPV, NPV and overall accuracy for MRS in detecting LN metastasis were 87.5%; 88%; 80.7%; 90.9%; and 86.4% respectively. Likelihood ratio for positive test and negative test for MRS to detect LN metastasis were 6.1 and 0.14 respectively.Conclusion: MRS can accurately predict presence of metastasis in axillary lymph nodes in vitro. In vivo studies are essential to corroborate these findings. Mean concentrations of metabolites in axillary lymph nodesInvolvedNon involvedP valueGPC0.5923(SD=0.5726)0.3648(SD=0.6774)0.02PC0.7347(SD=0.9466)0.5286(SD=1.1111)0.03Cho0.6930(SD=0.6756)0.8435(SD=0.5030)0.21Thr2.9656(SD=2.2397)1.1674(SD=1.2274)0.02Lac4.5515(SD=2.3271)3.2907(SD=1.3296)0.31 Citation Format: Srineil Vuthaluru, Anurag Srivastava. Role of MR spectroscopy in evaluation of axilla in breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-38.

Spectroscopic evaluation of chalcone derivatives and their zinc metal complexes: A combined experimental and computational approach studying the interactions of the complexes with the serum albumin

• Zinc metal ions contributes to an increase binding affinity of chalcones to the serum albumin • Structural elucidation of chalcone derivatives via TD-DFT • Zinc-Chalcone complexes synthesis Three chalcone derivatives ( L 1 , L 2 , L 3 ) were synthesized using Claisen-Schmidt condensation reaction. Their molecular structures and spectroscopic properties (IR, UV-vis, 1 HNMR), were calculated at B3LYP level. Electrostatic interactions and HOMO-LUMO properties were calculated using TD-DFT method. Molecular docking was used to compare the HSA (human serum albumin) interactions with the ligands and their Zn complexes ( C 1 , C 2 , C 3 ) which were synthesized by interaction between the ligands and the Zn (II) ion in a 2:1 M ratio. Elemental analysis, FT-IR, and UV–Vis spectroscopy studies investigated the structure of the synthesized complexes. UV–Vis, molecular docking and molecular dynamics were used to study the interactions of the Zn complexes with the BSA (bovine serum albumin). The biological activity of the Zn-Chalcone complexes was generally higher than the chalcones when evaluated spectroscopically and theoretically.

Spectroscopic and DFT evaluation of the positional effect of amino group on the properties of aminobenzenesulphonic acid: solvents interactions

Positional effect of NH2 group on the properties of aminobenzenesulphonic acid (AMBSA) has been investigated. Potential energy scan (PES) calculation revealed the energy difference between the two global minima predicted for each of the derivatives to be decreasing with the increasing distance between the –NH2 substituent and the –SO3H moiety. On the other hand, the zero-point energy affirmed the ortho and para substituted AMBSAs as being more stable than the meta counterpart by 1.7 kcal/mol. The derivatives showed comparable chemical reactivity, whereas the simulation of their solubility in the selected solvents affirmed the 4-aminobenzenesulphonic acid to be generally more soluble than the other derivatives. Application of Kamlet–Taft model on the absorption data of the aminobenzenesulphonic acids revealed the influence of solvent polarity together with hydrogen bonding ability on their solubility. On the part of vibrational property, the vibrational modes associated with –SO3H moiety were found to be sensitive to the position of amino substituent.