Reflectance spectroscopy: a non-invasive strategy to explore skin reactions to topical products.

Reflectance spectroscopy has emerged as a powerful analytical technique in the field of dermatology, offering a non-invasive strategy to assess several cutaneous properties and skin response to topical products. By analyzing reflected light across different wavelengths, reflectance spectroscopy allows the quantification of cutaneous parameters, such as erythema index and melanin content. Moreover, this analytical technique enables the monitoring of any changes in skin physiology facilitating the assessment of long-term effects of topical products as well as predicting cutaneous diseases. This review provides an overview of the application of reflectance spectroscopy in investigating skin properties and reaction to topical applied products, including both pharmaceutical and cosmetic formulations, thereby aiding in the development of personalized solutions tailored to individual needs.

Assessment of fungal species in some spices using molecular study with detection of their mycotoxins using chromatography analysis.

Spices are food flavouring agents that are highly used in Iraq. However, they may be contaminated by toxicogenic fungi and subsequent production of mycotoxins. The aim of this study was to investigate the contamination of commonly used spices with fungi using polymerase chain reaction (PCR) assay and to detect fungal mycotoxin using high-performance liquid chromatography. Thirty-five spices (seven samples from each black pepper, red pepper, turmeric, cumin and ginger) were cultured on an appropriate medium to identify various fungi species. Later on, the toxigenicity of Aspergillus flavus and Aspergillus niger was determined using a PCR assay. The fungal mycotoxins, including aflatoxins and ochratoxins, were then determined through a high-performance liquid chromatography using the validated Quick, Easy, Cheap, Effective, Rugged, and Safe (QuECHERS) method. Aspergillus species were the predominantly isolated fungi, followed by Penicillium and Fusarium. The PCR results indicate the high toxigenicity of A. flavus as 85.7% of the strains had aflQ/aflR genes and 79% had PKS15KS/PKS15C-MeT genes. Regarding mycotoxin contamination in spices, the highest rates of aflatoxins and ochratoxins were found in black pepper (5.913 µg/kg) and red chilli (6.9055 µg/kg), respectively. Spices are susceptible substrates for the growth of mycotoxigenic fungi. Thus, regular effective surveillance and quality control procedures are highly recommended.

Quantification of Arbortristoside-A isolated from Nyctanthes arbor-tristis using HPLC: Method development and pharmaceutical applications.

Arbortristoside-A (Arbor-A) is a naturally occurring iridoid glycoside and herbal-based lead molecule with proven medicinal potential. Aiming at the development of an efficient analytical tool for the quantification of Arbor-A in pharmaceutical dosage forms, in the presented work, we developed an economical, fast, and sensitive RP-HPLC-UV method and validated the procedure as per the ICH guidelines, Q2(R1). The chromatographic separation was accomplished under the optimised experimental conditions using an HPLC system with an LC-2010 autosampler, a PDA detector, and a Phenomenex C18 column with the mobile phase composed of a 70:30 (v/v) water-acetonitrile mixture eluting isocratically at a flow rate of 1 mL/min at ambient temperature, and UV detection at 310 nm. Arbor-A showed a sharp peak at the retention time of 5.60 min and exhibited linearity (R2 = 0.9988) with LOD and LOQ of 0.50 µg/mL and 1.50 µg/mL, respectively. The accuracy of the method was 98.33-101.36 % with acceptable intra-day and inter-day precisions as well as robustness (<2% RSD). To ratify the applicability of the presented approach in emerging pharmaceuticals, a nanoformulation loaded with Arbor-A was designed and analysed utilising the provided methodology. The method has also enabled to determine the degradation kinetics of Arbor-A under stress conditions, etcetera, employing forced degradation and short term stability studies.

Technological advances for analyzing the content of organ-on-a-chip by mass spectrometry.

Three-dimensional (3D) cell cultures, including organ-on-a-chip (OOC) devices, offer the possibility to mimic human physiology conditions better than 2D models. The organ-on-a-chip devices have a wide range of applications, including mechanical studies, functional validation, and toxicology investigations. Despite many advances in this field, the major challenge with the use of organ-on-a-chips relies on the lack of online analysis methods preventing the real-time observation of cultured cells. Mass spectrometry is a promising analytical technique for real-time analysis of cell excretes from organ-on-a-chip models. This is due to its high sensitivity, selectivity, and ability to tentatively identify a large variety of unknown compounds, ranging from metabolites, lipids, and peptides to proteins. However, the hyphenation of organ-on-a-chip with MS is largely hampered by the nature of the media used, and the presence of nonvolatile buffers. This in turn stalls the straightforward and online connection of organ-on-a-chip outlet to MS. To overcome this challenge, multiple advances have been made to pre-treat samples right after organ-on-a-chip and just before MS. In this review, we summarised these technological advances and exhaustively evaluated their benefits and shortcomings for successful hyphenation of organ-on-a-chip with MS.

Variational iteration method along with intelligent computing system for the radiated flow of electrically conductive viscous fluid through porous medium.

This article aims to investigate the analytical nature and approximate solution of the radiated flow of electrically conductive viscous fluid into a porous medium with slip effects (RFECVF). In order to build acceptable accurate solutions for RFECVF, this study presented an efficient Levenberg-Marquardt technique of artificial neural networks (LMT-ANNs) approach. One of its fastest back-propagation algorithms for nonlinear lowest latency is the LMT. To turn a quasi-network of PDEs expressing RFECVF into a set of standards, the appropriate adjustments are required. During the flow, the boundary is assumed to be convective. The flow and heat transfer are governed by partial differential equations, and similarity transform is the main tool to convert it into a coupled nonlinear system of ODEs. The usefulness of the constructed LMT-ANNs for such a modelled issue is demonstrated by the best promising algebraic outputs in the E-03 to E-08 range, as well as error histogram and regression analysis measures. Mu is a controller that oversees the entire training procedure. The LMT-ANNs mainly focuses on the higher accuracy of nonlinear systems. Analytical results for the improved boundary layer ODEs are produced using the Variational Iteration Method, a tried-and-true method (VIM). The Lagrange Multiplier is a powerful tool in the suggested method for reducing the amount of computing required. Further, a tabular comparison is provided to demonstrate the usefulness of this study. The final results of the Variational Iteration Method (VIM) in MATLAB have accurately depicted the physical characteristics of a number of parameters, including Eckert, Prandtl, Magnetic, and Thermal radiation parameters.

Mass spectrometry in food authentication and origin traceability.

Food authentication and origin traceability are popular research topics, especially as concerns about food quality continue to increase. Mass spectrometry (MS) plays an indispensable role in food authentication and origin traceability. In this review, the applications of MS in food authentication and origin traceability by analyzing the main components and chemical fingerprints or profiles are summarized. In addition, the characteristic markers for food authentication are also reviewed, and the advantages and disadvantages of MS-based techniques for food authentication, as well as the current trends and challenges, are discussed. The fingerprinting and profiling methods, in combination with multivariate statistical analysis, are more suitable for the authentication of high-value foods, while characteristic marker-based methods are more suitable for adulteration detection. Several new techniques have been introduced to the field, such as proton transfer reaction mass spectrometry, ambient ionization mass spectrometry (AIMS), and ion mobility mass spectrometry, for the determination of food adulteration due to their fast and convenient analysis. As an important trend, the miniaturization of MS offers advantages, such as small and portable instrumentation and fast and nondestructive analysis. Moreover, many applications in food authentication are using AIMS, which can help food authentication in food inspection/field analysis. This review provides a reference and guide for food authentication and traceability based on MS.

Current sample preparation methods and analytical techniques for the determination of synthetic antioxidants in edible oils.

Synthetic antioxidants play a critical role in the storage and process of edible oils due to that they can retard lipid oxidation, maintain the quality of oils, and prolong the shelf life. However, a series of studies have proved the potential risks of synthetic antioxidants for human health when consumed in excess, and many countries have established the permitted amounts of synthetic antioxidants in oils. Thus, the accurate quantification of synthetic antioxidants in edible oils is necessary, and there have developed various analytical methods involved in chromatographical, electrochemical, and spectroscopic methods. Owing to the complex matrix and the incompatibility between the oil sample and the detection instrument, sample preparation is usually adopted prior to the instrument detection to improve the detection effectiveness. The current review aims to provide a comprehensive overview of the recently developed sample preparation methods and analytical techniques applied to determine synthetic antioxidants in edible oils from 2010 to present, with emphasis on the sample preparation methods combined with separation-based analytical techniques such as capillary electrophoresis and liquid chromatography with various detectors. The advantages and limitations of some typical analytical methods are discussed and some insights in the future perspectives are also provided in this review.

Comparison of signal-averaging and regression approaches to analyzing sympathetic transduction.

PURPOSE: Spontaneous sympathetic transduction reflects the vascular and/or pressor responses to bursts of muscle sympathetic nerve activity (MSNA). Separately, signal-averaging and regression-based approaches have been implemented to quantify resting sympathetic transduction. It is unknown whether the outcomes of these analytical approaches provide (dis)similar information, which is imperative for between-study comparisons and the amalgamation of results for synthesis of multiple studies (i.e., meta-analyses). We explored the diastolic blood pressure (DBP) responses to spontaneous bursts of MSNA between these two methods of analysis. METHODS: Resting beat-by-beat DBP (via finger photoplethysmography) and common peroneal nerve MSNA (via microneurography) were recorded in 52 healthy, normotensive adults (age 38 ± 20 years; 19 females). For the signal-averaged method, transduction was quantified as the mean peak increase in DBP (ΔDBP) during the 12 cardiac cycles following each MSNA burst. In addition, DBP was regressed to a moving two-cardiac-cycle window of normalized relative burst height (mmHg/relative %) to provide the regression-based transduction outcome. RESULTS: The signal-averaged (1.2 ± 0.7 mmHg) and regression-based approaches (0.009 ± 0.016 mmHg/%) were unrelated (ρ = 0.03, p = 0.86). Adding to the discrepancy, only the signal-averaging approach demonstrated a lower transduction in middle-aged-older males versus younger males. CONCLUSIONS: The decision of which method to use when calculating sympathetic transduction influences study outcomes, with the two most common methods of determining transduction being unrelated. There are challenges of making sweeping conclusions across studies if different analysis strategies are implemented. An understanding of when to use each method is needed to adopt a harmonized approach to quantifying sympathetic transduction.

Efficiency calculation of proton recoil neutron telescope with relativistic correction for neutron energy 4 to 20 MeV.

The efficiencies of a proton recoil neutron telescope for neutron energies ranging from 4 MeV to 20 MeV were calculated for different geometries given by Bame et al., for the case of an isotropic point neutron source colinear with the radiator and charge particle detector that are parallel & coaxial to each other. An analytical expression for the efficiency was obtained as a function of the radiator size, detector aperture, source-radiator & radiator-detector distances and n-p differential scattering cross section. The relativistic transformation of n-p differential scattering cross section from center-of-mass to laboratory system was used in the calculations, taking into account the angular anisotropy of the n-p scattering. The accuracies of the calculations were checked by comparing with published efficiency values by Thomas & Axton and Bame et al. The difference between calculated and published efficiencies were small and, in most cases, it was below 1%. Finally, efficiency of the telescope was calculated using the latest n-p scattering cross section data from the evaluated nuclear data file (ENDF) VII for neutron energies ranging from 4 MeV to 20 MeV.

Efficacy of Analytical Technologies in Metabolomics Studies of the Gastrointestinal Cancers.

According to the reports of the World Health Organization and the International Agency for Research on Cancer, cancer is the second leading cause of human death worldwide. However, early-stage detection of cancers can efficiently enhance the chance of therapy and saving lives. Metabolomics strategies apply a variety of approaches to discover new potential diagnoses, prognoses, and/or therapeutic biomarkers of various diseases. Metabolomics aims to identify and measure different low-molecular-weight biomolecules in physiological environments. In these studies, special metabolites are extracted from biological samples and identified using analytical techniques. Afterward, using data processing programs discovering significantly associated biomarkers is pursued. In the present review, we aimed to discuss recently reported analytical approaches on the metabolomics studies of gastrointestinal cancers including gastric, colorectal, and esophageal cancers. The gas- and liquid-chromatography with different detectors have been shown that are the main analytical techniques and for metabolites quantification, nuclear magnetic resonance has been utilized as a master method.

NMR technique and methodology in botanical health product analysis and quality control.

Botanicals have played an important role in maintaining human health and well-being throughout history. During the past few decades in particular, the use of botanical health products has gained more popularity. Whereas, quality, safety and efficacy concerns have continuously been critical issues due to the intrinsic chemical complexity of botanicals. Chemical analytical technologies play an imperative role in addressing these issues. Nuclear magnetic resonance (NMR) spectroscopy has proven to be a powerful and useful tool for the investigation of botanical health products. In this review, NMR techniques and methodologies that have been successfully applied to the research and development of botanical health products in all stages, from plants to products, are discussed and summarized. Furthermore, applications of NMR together with other analytical techniques in a variety of domains of botanical health products investigation, such as plant species differentiation, adulteration detection, and bio-activity evaluation, are discussed and illustrated with typical examples. This article provides an overview of the potential uses of NMR techniques and methodologies in an attempt to further promote their recognition and utilization in the field of botanical health products analysis and quality control.

A GC-SSIM-CRDS system: Coupling a gas chromatograph with a Cavity Ring-Down Spectrometer for onboard Twofold analysis of molecular and isotopic compositions of natural gases during ocean-going research expeditions.

Carbon dioxide (CO2) and methane (CH4) are two climate-sensitive components of gases migrating within sediments and emitted into the water column on continental margins. They are involved in several key biogeochemical processes entering into the global carbon cycle. In order to perform onboard measurements of both the molecular and stable carbon isotope ratios (δ13C) of CH4 and CO2 of natural gases during oceanic cruises, we have developed a novel approach coupling gas chromatography (GC) with cavity ring-down spectroscopy (CRDS). The coupled devices are connected to a small sample isotope module (SSIM) to form a system called GC-SSIM-CRDS. Small volumes of natural gas samples (<1 mL) are injected into the GC using a headspace autosampler or a gas-tight syringe to separate the chemical components using a Shincarbon ST packed column and for molecular quantification by thermal conductivity detection (TCD). Subsequently, CO2 from the sample is trapped in a 7 mL loop at 32 °C before being transferred to the CRDS analyzer for sequential determination of the stable carbon isotope ratios of CH4 and CO2 in 24 min. The loop is an open column (without stationary phase). This approach does not require the use of adsorbents or cooling for the trapping step. Optimization of the separation step prior to analysis was focused on the influence of two key separation factors 1) the flow of the carrier gas and 2) the temperature of the oven. Our analytical system and the measurement protocol were validated on samples collected from gas seeps in the Sea of Marmara (Turkey). Our results show that the GC-SSIM-CRDS system provides a reliable determination of the molecular identification of CH4 and CO2 in complex natural gases, followed by the stable carbon isotope ratios of methane and carbon dioxide.

Pharmacometabonomics: data processing and statistical analysis.

Individual variations in drug efficacy, side effects and adverse drug reactions are still challenging that cannot be ignored in drug research and development. The aim of pharmacometabonomics is to better understand the pharmacokinetic properties of drugs and monitor the drug effects on specific metabolic pathways. Here, we systematically reviewed the recent technological advances in pharmacometabonomics for better understanding the pathophysiological mechanisms of diseases as well as the metabolic effects of drugs on bodies. First, the advantages and disadvantages of all mainstream analytical techniques were compared. Second, many data processing strategies including filtering, missing value imputation, quality control-based correction, transformation, normalization together with the methods implemented in each step were discussed. Third, various feature selection and feature extraction algorithms commonly applied in pharmacometabonomics were described. Finally, the databases that facilitate current pharmacometabonomics were collected and discussed. All in all, this review provided guidance for researchers engaged in pharmacometabonomics and metabolomics, and it would promote the wide application of metabolomics in drug research and personalized medicine.

Trimethylamine N-oxide (TMAO) in human health.

Due to numerous links between trimethylamine-N-oxide (TMAO) and various disorders and diseases, this topic is very popular and is often taken up by researchers. TMAO is a low molecular weight compound that belongs to the class of amine oxides. It is formed by the process of oxidation of trimethylamine (TMA) by the hepatic flavin monooxygenases (FMO1 and FMO3). TMAO is mainly formed from nutritional substrates from the metabolism of phosphatidylcholine/choline, carnitine, betaine, dimethylglycine, and ergothioneine by intestinal microflora in the colon. Its level is determined by many factors, such as age, gender, diet, intestinal microflora composition, kidney function, and also liver flavin monooxygenase activity. Many studies report a positive relationship between the level of TMAO concentration and the development of various diseases, such as cardiovascular diseases and cardiorenal disorders, including atherosclerosis, hypertension, ischemic stroke, atrial fibrillation, heart failure, acute myocardial infarction, and chronic kidney disease, and also diabetes mellitus, metabolic syndrome, cancers (stomach, colon), as well as neurological disorders. In this review, we have summarized the current knowledge on the effects of TMAO on human health, the relationship between TMAO and intestinal microbiota, the role of TMAO in different diseases, and current analytical techniques used in TMAO determination in body fluids.

Hyper-Spectral Imaging Technique in the Cultural Heritage Field: New Possible Scenarios.

Imaging spectroscopy technique was introduced in the cultural heritage field in the 1990s, when a multi-spectral imaging system based on a Vidicon camera was used to identify and map pigments in paintings. Since then, with continuous improvements in imaging technology, the quality of spectroscopic information in the acquired imaging data has greatly increased. Moreover, with the progressive transition from multispectral to hyperspectral imaging techniques, numerous new applicative perspectives have become possible, ranging from non-invasive monitoring to high-quality documentation, such as mapping and characterization of polychrome and multi-material surfaces of cultural properties. This article provides a brief overview of recent developments in the rapidly evolving applications of hyperspectral imaging in this field. The fundamentals of the various strategies, that have been developed for applying this technique to different types of artworks are discussed, together with some examples of recent applications.

[Overview of Analytical Techniques for Evaluation of Nano-DDS Formulations].

Nanotechnology-based formulations have attracted much attention as delivery tools for a variety of payloads. These payloads include oligonucleotides, peptides, and low-molecular weight chemical entities. Guidelines and reflection papers for nanotechnology-based drug products have been published by the Japanese Ministry of Health, Labour, and Welfare. These documents include the concept of quality by design (QbD) approach, as described in the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The quality attributes that affect efficacy and safety of nanotechnology-based drug products should be identified to establish the entire picture of the drug products. Hence it is essential to develop analytical methods for characterizing these attributes. Furthermore, to evaluate the comparability of nano-drug delivery system (DDS) formulations before and after changes to their manufacturing process, it is desirable to characterize the key attributes using more than one analytical method for each. Standardization of these analytical methods is underway. This paper provides an overview of the concept and significance of the QbD approach for nano-DDS formulations, guidelines for the development of nano-DDS formulations, and standardization of analytical methods for nano-DDS formulations.

Creative use of analytical techniques and high-throughput technology to facilitate safety assessment of engineered nanomaterials.

With the rapid development and numerous applications of engineered nanomaterials (ENMs) in science and technology, their impact on environmental health and safety should be considered carefully. This requires an effective platform to investigate the potential adverse effects and hazardous biological outcomes of numerous nanomaterials and their formulations. We consider predictive toxicology a rational approach for this effort, which utilizes mechanism-based in vitro high-throughput screening (HTS) to make predictions on ENMs' adverse outcomes in vivo. Moreover, this approach is able to link the physicochemical properties of ENMs to toxicity that allows the development of structure-activity relationships (SARs). To build this predictive platform, extensive analytical and bioanalytical techniques and tools are required. In this review, we described the predictive toxicology approach and the accompanying analytical and bioanalytical techniques. In addition, we elaborated several successful examples as a result of using the predictive approach.

A técnica zen como resposta lacaniana à crise da técnica analítica / The zen technique as a Lacanian response to the crisis of analytical technique / La technique zen comme réponse lacanienne à la crise de la technique analytique

O texto procura investigar uma resposta lacaniana àquilo que ele próprio chamou de crise da técnica analítica (1953/1998) entre os pós-freudianos. Destaca alguns impasses decorrentes da noção de eu e suas consequências clínicas e teóricas, bem como a tentativa de manutenção de uma técnica padronizada e destituída de uma epistemologia freudiana que resultou em desvios entre aqueles que Lacan chama de pós-freudianos. Aponta o recurso à técnica zen no início do ensino de Lacan como uma crítica a um desvio da prática, como um princípio não identitário e não essencialista do eu. O zen não seria um recurso alegórico numa retórica lacaniana, mas uma forma precisa de retomada de um pensamento da negatividade em conformidade com uma epistemologia freudiana no interior da prática analítica.

The text seeks to investigate a Lacanian response to what he himself called the "crisis of analytic technique" among post-Freudians. It highlights some impasses arising from the notion of "Ego" and its clinical and theoretical consequences. It points to the use of the Zen technique, at the beginning of Lacan's teaching, as a critique of a deviation from practice, and as a non-identitarian and non-essentialist principle of the self. Zen would not be an allegorical feature in Lacanian rhetoric, but a precise form of resumption of a thought of negativity within analytic practice.

Le texte cherche à étudier une réponse lacanienne à ce qu'il appelle la crise postfreudienne de la technique analytique (1953/1998). Il met en évidence certaines impasses découlant de la notion de moi et de ses conséquences cliniques et théoriques. Ainsi que la tentative de maintenir une technique standardisée dépourvue d'une épistémologie freudienne, qui a abouti à des déviations entre celles que Lacan appelle postfreudiennes. Il souligne l'utilisation de la technique zen au début de l'enseignement de Lacan comme une critique d'une déviation de la pratique en tant que principe non identitaire et non essentiel de moi. Le Zen ne serait pas un trait allégorique dans une rhétorique Lacanienne, mais un moyen précis de reprendre une pensée de négativité en accord avec une épistémologie freudienne dans la pratique analytique.

Thermodynamic and kinetic analyses of curcumin and bovine serum albumin binding.

Bovine serum albumin (BSA)/curcumin binding and dye photodegradation stability were evaluated. BSA/curcumin complex showed 1:1 stoichiometry, but the thermodynamic binding parameters depended on the technique used and BSA conformation. The binding constant was of the order of 105L·mol-1 by fluorescence and microcalorimetric, and 103 and 104L·mol-1 by surface plasmon resonance (steady-state equilibrium and kinetic experiments, respectively). For native BSA/curcumin, fluorescence indicated an enthalpic and entropic driven process based on the standard enthalpy change (ΔH○F=-8.67kJ·mol-1), while microcalorimetry showed an entropic driven binding process (ΔH○cal=29.11kJ·mol-1). For the unfolded BSA/curcumin complex, it was found thatp ΔH○F=-16.12kJ·mol-1 and ΔH○cal=-42.63kJ·mol-1. BSA (mainly native) increased the curcumin photodegradation stability. This work proved the importance of using different techniques to characterize the protein-ligand binding.