Colorimetric pH-sensing of artificial gastric fluid using naphthalimide-based CH acids.

In this study, we introduce novel colorimetric pH-sensing probes based on naphthalimide malonate derivatives. These probes were synthesized by reacting 4-bromo-1,8-naphthalimide with various malonates, including malononitrile, ethyl cyanoacetate, and diethyl malonate. Each derivative exhibited distinct pH-sensing characteristics due to their differing CH acidities.

Potential authentication of re-esterified triacylglycerol-type omega-3 oils using multivariate analysis of lipid profiles.

This study aimed to authenticate re-esterified triacylglycerol (rTG)-type omega-3 oils prone to adulteration with fatty acid ethyl ester (FAEE)-type oils via hierarchical cluster analysis (HCA) and principal component analysis (PCA) of their lipid profiles. A total of 104 rTG-type omega-3 oil samples, consisting of seven authentic (two commercial and five laboratory-made), 60 adulterated, and 37 unauthenticated commercial samples, were analyzed for their acylglycerol, FAEE, and total EPA/DHA contents. Type 1 authentic samples contained higher triacylglycerols (TG) (63.

Wet Mechanochemical Synthesis of BH-Substituted Lithium Argyrodites.

In all-solid-state batteries, a solid electrolyte with high ionic conductivity is required for fast charging, uniform lithium deposition, and increased cathode capacity. Lithium argyrodite with BH substitution has promising potential due to its higher ionic conductivity compared to argyrodites substituted with halides. In this study, LiPS(BH), characterized by a high ionic conductivity of 13.

Evaluation of sterols as markers of fungal spoilage in red pepper powder.

Red pepper powder (RPP) made from ground dried red pepper (Capsicum annuum L.) is prone to adulteration with fungal-spoiled RPP to gain unfair profits in Korea. This study aimed to investigate the effects of fungal infection on the ergosterol and phytosterol content of RPP and evaluate the potential of the sterol content as a marker for identifying fungal-spoiled RPP.

Geographical discrimination of Asian red pepper powders using H NMR spectroscopy and deep learning-based convolution neural networks.

This study investigated an innovative approach to discriminate the geographical origins of Asian red pepper powders by analyzing one-dimensional H NMR spectra through a deep learning-based convolution neural network (CNN). H NMR spectra were collected from 300 samples originating from China, Korea, and Vietnam and used as input data. Principal component analysis - linear discriminant analysis and support vector machine models were employed for comparison.

A colorimetric and fluorescent signaling probe for assaying Pd in practical samples.

We developed an optical signaling probe to detect Pd ions in Pd-containing catalyst and drug candidate. The Pd signaling probe (Res-DT) was readily prepared by reacting the versatile fluorochrome resorufin with phenyl chlorodithioformate. In a phosphate-buffered saline solution (pH 7.

Changes of molecular mobility of ascorbyl palmitate and α-tocopherol by phospholipid and their effects on antioxidant properties in bulk oil.

Molecular mobility of ascorbyl palmitate and α-tocopherol in the presence of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) were determined by NMR relaxation technique. Synergistic effects of DOPC on the antioxidative capacities of ascorbyl palmitate were evaluated in DPPH radical scavenging assay and bulk oil matrix. NMR relaxation technique can provide information on the mobility of protons.

Colorimetric screening of elevated urinary mercury levels by a novel Hg-selective probe of resorufin phosphinothioate.

Urinary mercury levels are the most reliable indicators of mercury exposure but identifying them requires complex techniques and heavy instruments. In this research, we reported a simple and convenient urinary mercury analysis method using a readily available office scanner. Probe MP-1 synthesized by the reaction of resorufin and dimethylthiophosphinoyl chloride revealed Hg-selective chromogenic and fluorescent signaling behavior.

Combined analysis of inorganic elements and sugars for the identification of red pepper powder containing undeclared ingredients.

This study sought to identify adulterated red pepper powder (RPP) containing undeclared ingredients, such as salts, glucose, Monascus red pigments, and other plant ingredients (e.g., wheat flour, garlic powder, onion powder) using element and sugar analysis methods.

Development and Validation of a Simple Method to Quantify Contents of Phospholipids in Krill Oil by Fourier-Transform Infrared Spectroscopy.

This study focuses on developing a quantification method for phosphatidylcholine (PC) and total phospholipid (PL) in krill oil using Fourier-transform infrared (FT-IR) spectroscopy. Signals derived from the choline and phosphate groups were selected as indicator variables for determining PC and total PL content; calibration curves with a correlation coefficient of >0.988 were constructed with calibration samples prepared by mixing krill oil raw material and fish oil in different ratios.

Hydrazone Photoswitches for Structural Modulation of Short Peptides.

Molecules that undergo light-driven structural transformations constitute the core components in photoswitchable molecular systems and materials. Among various families of photoswitches, photochromic hydrazones have recently emerged as a novel class of photoswitches with superb properties, such as high photochemical conversion, spectral tunability, thermal stability, and fatigue resistance. Hydrazone photoswitches have been adopted in various adaptive materials at different length scales, however, their utilization for modulating biomolecules still has not been explored.

Distinguishing Korean and Chinese red pepper powder using inductively coupled plasma and X-ray fluorescence-based analysis.

This study aimed to distinguish between Korean and Chinese red pepper powder (RPP) using inorganic elemental analysis data combined with orthogonal partial least squares-discriminant analysis (OPLS-DA). Elemental concentrations were obtained for 31 Korean and 31 Chinese RPP samples that were collected in Korea. Energy dispersive X-ray fluorescence spectroscopy detected 11 elements in these samples.

Discriminant Analysis of the Geographical Origin of Asian Red Pepper Powders Using Second-Derivative FT-IR Spectroscopy.

This study aimed to discriminate between the geographical origins of Asian red pepper powders distributed in Korea using Fourier-transform infrared (FT-IR) spectroscopy coupled with multivariate statistical analyses. Second-derivative spectral data were obtained from a total of 105 red pepper powder samples, 86 of which were used for statistical analysis, and the remaining 19 were used for blind testing. A one-way analysis of variance (ANOVA) test confirmed that eight peak variables exhibited significant origin-dependent differences, and the canonical discriminant functions derived from these variables were used to correctly classify all the red pepper powder samples based on their origins.

Rubidium analysis as a possible approach for discriminating between Korean and Chinese perilla seeds distributed in Korea.

The aim of this study was to discriminate between Korean and Chinese perilla seeds by using inorganic elemental analysis data combined with orthogonal partial least squares-discriminant analysis (OPLS-DA). Inorganic element content data were obtained from 29 Korean and 11 Chinese perilla seed samples distributed in Korea. Using energy dispersive X-ray fluorescence spectroscopy, 11 species of inorganic elements were detected in the perilla seed samples and eight of them were quantified.

The first hydride-Meisenheimer adduct of electron-deficient 3-nitronaphthalimide: application to colorimetric borohydride determination.

The first hydride-Meisenheimer adduct of 3-nitronaphthalimide was used for the colorimetric borohydride assay. To explain the regioselectivity of the adduct, the reaction enthalpies of the two most plausible Meisenheimer adducts were obtained via computational calculation. Using the adduct formation, the assay of borohydride reagents was successfully conducted.

A Second Derivative Fourier-Transform Infrared Spectroscopy Method to Discriminate Perilla Oil Authenticity.

The aim of this study was to discriminate the authenticity of perilla oils distributed in Korea using their Fourier-Transform infrared spectroscopy (FT-IR) spectra with attenuated total reflectance accessory. By using orthogonal projections for latent structures discriminant analysis (OPLS-DA) technique, the =C-H cis-double bond, -C-H asymmetric and -C-H symmetric stretching are determined to be the best variables for discriminating the perilla oil authenticity. Comparing the integral and the second derivative methods between authentic and adulterated perilla oil samples, the most obvious and significant differences among the three variables is =C-H cis-double bond stretching.

Electronic Effect on the Molecular Motion of Aromatic Amides: Combined Studies Using VT-NMR and Quantum Calculations.

Rotational barrier energy studies to date have focused on the amide bond of aromatic compounds from a kinetic perspective using quantum calculations and nuclear magnetic resonance (NMR). These studies provide valuable information, not only regarding the basic conformational properties of amide bonds but also the molecular gear system, which has recently gained interest. Thus, we investigate the precise motion of the amide bonds of two aromatic compounds using an experimental rotational barrier energy estimation by NMR experiments and a theoretical evaluation of the density functional theory calculation.

High-performance and scalable metal-chalcogenide semiconductors and devices via chalco-gel routes.

We report a general strategy for obtaining high-quality, large-area metal-chalcogenide semiconductor films from precursors combining chelated metal salts with chalcoureas or chalcoamides. Using conventional organic solvents, such precursors enable the expeditious formation of chalco-gels, which are easily transformed into the corresponding high-performance metal-chalcogenide thin films with large, uniform areas. Diverse metal chalcogenides and their alloys (MQ : M = Zn, Cd, In, Sb, Pb; Q = S, Se, Te) are successfully synthesized at relatively low processing temperatures (<400°C).

A 43 MHz Low-Field Benchtop H Nuclear Magnetic Resonance Method to Discriminate Perilla Oil Authenticity.

The aim of this study was to discriminate the authenticity of perilla oils distributed in Korea using their H nuclear magnetic resonance (NMR) spectra acquired by a 43 MHz low-field benchtop NMR spectrometer. Significant differences existed in the integration values of all 6 peaks found in the spectrum between authentic and adulterated perilla oil samples. The integration values of 4 peaks that signify the methylene protons present in all fatty acids (FA) and allylic or olefinic protons present in all unsaturated FA were the best variables for establishing perilla oil authenticity.

A Nuclear Magnetic Resonance Spectroscopy Approach to Discriminate the Geographic Origin of Roasted Asian Sesame Oils.

The aim of this study was to discriminate the geographic origin of Korean, Chinese, and Indian sesame oils distributed in Korea using H NMR spectroscopy in combination with canonical discriminant analysis (CDA). H NMR spectra were obtained from 84 roasted oil samples prepared from 51 Korean, 19 Chinese, and 14 Indian sesame seeds. The integration values of 26 peaks observed in the NMR spectra were determined and normalized on the basis of the peak derived from the terminal CH of the fatty acids (0.

Combined Analysis of Stable Isotope, (1)H NMR, and Fatty Acid To Verify Sesame Oil Authenticity.

The aim of this study was to verify the authenticity of sesame oils using combined analysis of stable isotope ratio, (1)H NMR spectroscopy, and fatty acid profiles of the oils. Analytical data were obtained from 35 samples of authentic sesame oils and 29 samples of adulterated sesame oils currently distributed in Korea. The orthogonal projection to latent structure discriminant analysis technique was used to select variables that most effectively verify the sesame oil authenticity.

High resolution in vivo 31P-MRS of the liver: potential advantages in the assessment of non-alcoholic fatty liver disease.

Background: Biopsy remains the current gold-standard for assessing non-alcoholic fatty liver disease (NAFLD). To develop a non-invasive means of assessing the disease, 31P magnetic resonance spectroscopy (31P-MRS) has been explored, but the severe spectral overlaps and low signal-to-noise-ratio in 31P-MRS spectra at clinical field strength are clearly limiting factors.

Purpose: To investigate potential advantages of high resolution in vivo 31P-MRS in assessing NAFLD.

In vivo (1)H-MRS hepatic lipid profiling in nonalcoholic fatty liver disease: an animal study at 9.4 T.

The applicability of the in vivo proton magnetic resonance spectroscopy hepatic lipid profiling (MR-HLP) technique in nonalcoholic fatty liver disease was investigated. Using magnetic resonance spectroscopy, the relative fractions of diunsaturated (fdi), monounsaturated (fmono), and saturated (fsat) fatty acids as well as total hepatic lipid content were estimated in the livers of 8 control and 23 CCl4-treated rats at 9.4 T.

Detection of iron-labeled single cells by MR imaging based on intermolecular double quantum coherences at 14 T.

To evaluate the efficiency and feasibility of intermolecular multiple quantum coherence (iMQC) magnetic resonance (MR) imaging for single cell detection, we obtained intermolecular double quantum coherence (iDQC) and conventional gradient echo (GE) images of macrophage cells labeled by contrast agents in gel. The iDQC images obtained with echo-planar readout visualized the labeled cells effectively and with a higher contrast than seen in conventional GE images, especially at low planar resolutions and with thick slices. This implies that iDQC imaging with contrast agents could be a good alternative to conventional MR imaging for detecting labeled single cells or cell tracking under favorable conditions.