Semi-quantitative Method Research Articles

Mixed-phase weak anion-exchange/reversed-phase LC–MS/MS for analysis of nucleotide sugars in human fibroblasts

Nucleotide sugars (NS) fulfil important roles in all living organisms and in humans, related defects result in severe clinical syndromes. NS can be seen as the “activated” sugars used for biosynthesis of a wide range of glycoconjugates and serve as substrates themselves for the synthesis of other nucleotide sugars. NS analysis is complicated by the presence of multiple stereoisomers without diagnostic transition ions, therefore requiring separation by liquid chromatography. In this paper, we explored weak anion-exchange/reversed-phase chromatography on a hybrid column for the separation of 17 nucleotide sugars that can occur in humans. A robust and reproducible method was established with intra- and inter-day coefficients of variation below 10% and a linear range spanning three orders of magnitude. Application to patient fibroblasts with genetic defects in mannose-1-phosphate guanylyltransferase beta, CDP-l-ribitol pyrophosphorylase A, and UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase showed abnormal levels of guanosine-5′-diphosphate-α-d-mannose (GDP-Man), cytidine-5′-diphosphate-l-ribitol (CDP-ribitol), and cytidine-5′-monophosphate-N-acetyl-β-d-neuraminic acid (CMP-Neu5Ac), respectively, in consonance with expectations based on the diagnosis. In conclusion, a novel, semi-quantitative method was established for the analysis of nucleotide sugars that can be applied to diagnose several genetic glycosylation disorders in fibroblasts and beyond.

Comparison of Bone Mineral Density and Trabecular Bone Score in Patients with and without Vertebral Fractures and Differentiated Thyroid Cancer with Long-Term Serum Thyrotrophin-Suppressed Therapy.

The study of BMD provides only partial information on bone health in patients undergoing TSH suppression therapy due to differentiated thyroid cancer (DTC). The trabecular bone score (TBS), a new parameter assessing bone microarchitecture, is proposed for studying bone in this context. This study aimed to analyze their long-term use in patients with DTC. Bone mineral density (BMD) was measured by dual X-ray densitometry (DXA) and TBS was assessed with iNsigth software (version 2.0, MediImaps, France) in 145 postmenopausal patients with DTC. Vertebral fractures (VFs) were identified using a semi-quantitative X-ray method. The BMD at the end of this study did not differ from the initial measurement. However, the TBS decreased from 1.35 ± 0.1 to 1.27 ± 0.1 (p = 0.002). Increased levels of PTH, osteocalcin, and bone alkaline phosphatase (BAP) were observed, suggesting enhanced bone remodeling. There was an increase in the prevalence of osteoporosis and osteopenia (40.6% and 16.5% to 46.6% and 18.6%, respectively). The proportion of patients with partially degraded and totally degraded TBS increased from 31% and 15.1% to 48.9% and 24.8% by the end of this study. Among the 30 patients with VFs, there were no significant differences in age, body mass index (BMI), calcium intake, alcohol consumption, smoking, radioiodine, therapy, or thyroid parameters compared to those without VFs. The odds ratio for VFs increased with osteopenia (OR 2.63). Combining TBS with BMD did not improve discrimination. The TBS decreased while the BMD remained unchanged. The percentage of patients with osteoporosis and osteopenia, whether partially degraded or totally degraded, increased by the end of this study. The predominant discordance was found in partially degraded microarchitectures, with a higher proportion of osteopenic patients compared to those with normal or osteoporotic bone density. The AUC of the combination of TBS and BMD did not enhance discrimination. TBS, radioactive iodine therapy, and sedentary lifestyle emerged as the main distinguishing factors for DTC patients with VFs.

Antimicrobial efficacy of Punica granatum Lythraceae peel extract against pathogens belonging to the ESKAPE group.

The improper use and abuse of antibiotics have led to an increase in multidrug-resistant (MDR) bacteria resulting in a failure of standard antibiotic therapies. To date, this phenomenon represents a leading public health threat of the 21st century which requires alternative strategies to fight infections such as the identification of new molecules active against MDR strains. In the last 20 years, natural extracts with biological activities attracted scientific interest. Following the One Health Approach, natural by-products represent a sustainable and promising alternative solution. Consistently, the aim of the present study was to evaluate the antimicrobial activity of hydro-alcoholic pomegranate peel extract (PPE) against MDR microorganisms belonging to Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. "ESKAPE" group pathogens. Through semiquantitative and quantitative methods, the PPE showed effective antimicrobial activity against Gram-positive and Gram-negative MDR bacteria. The kinetics of bactericidal action of PPE highlighted that microbial death was achieved in a time- and dose-dependent manner. High concentrations of PPE exhibited antioxidant activity, providing a protective effect on cellular systems and red blood cell membranes. Finally, we report, for the first time, a significant intracellular antibacterial property of PPE as highlighted by its bactericidal action against the staphylococcal reference strain and its bacteriostatic effect against clinical resistant strain in the HeLa cell line. In conclusion, due to its characterized content of polyphenolic compounds and antioxidant activity strength, the PPE could be considered as a therapeutic agent alone or in conjunction with standard antibiotics against challenging infections caused by ESKAPE pathogens.

External evaluation of a deep learning-based approach for automated brain volumetry in patients with huntington’s disease

A crucial step in the clinical adaptation of an AI-based tool is an external, independent validation. The aim of this study was to investigate brain atrophy in patients with confirmed, progressed Huntington's disease using a certified software for automated volumetry and to compare the results with the manual measurement methods used in clinical practice as well as volume calculations of the caudate nuclei based on manual segmentations. Twenty-two patients were included retrospectively, consisting of eleven patients with Huntington's disease and caudate nucleus atrophy and an age- and sex-matched control group. To quantify caudate head atrophy, the frontal horn width to intercaudate distance ratio and the intercaudate distance to inner table width ratio were obtained. The software mdbrain was used for automated volumetry. Manually measured ratios and automatically measured volumes of the groups were compared using two-sample t-tests. Pearson correlation analyses were performed. The relative difference between automatically and manually determined volumes of the caudate nuclei was calculated. Both ratios were significantly different between the groups. The automatically and manually determined volumes of the caudate nuclei showed a high level of agreement with a mean relative discrepancy of − 2.3 ± 5.5%. The Huntington's disease group showed significantly lower volumes in a variety of supratentorial brain structures. The highest degree of atrophy was shown for the caudate nucleus, putamen, and pallidum (all p < .0001). The caudate nucleus volume and the ratios were found to be strongly correlated in both groups. In conclusion, in patients with progressed Huntington's disease, it was shown that the automatically determined caudate nucleus volume correlates strongly with measured ratios commonly used in clinical practice. Both methods allowed clear differentiation between groups in this collective. The software additionally allows radiologists to more objectively assess the involvement of a variety of brain structures that are less accessible to standard semiquantitative methods.

Revealing the intrinsic sintering mechanism of high-strength ceramsite from CFB fly ash: Focus on the role of CaO

The preparation of high-strength ceramsite from circulating fluidized bed (CFB) fly ash is an effective approach for commercial utilization. The role of CaO plays a key factor in the performance of ceramsite. The impact of CaO on the sintering mechanism was studied at the sintering temperature from 1200 °C to 1300 °C and the CaO addition ratio from 2 wt% to 8 wt%. The in-situ visual furnace equipped with a high-resolution microscope, incorporated with TG-DSC-FTIR, SEM, XRD, and the semi-quantitative analysis method of XRD, was conducted to investigate the sintering process of ceramsite. The results verified that during the high-temperature sintering, CaO reacted with SiO2 and Al2O3 in CFB fly ash to constitute low-melting minerals like anorthite, and the elevation of sintering temperature expedited the conversion of anorthite and eutectics into the molten liquid phase. The expansion gas was wrapped by the molten liquid phase and reached equilibrium, which contributed to the closure of the pores and the elevation of the shrinkage rate of ceramsite. In addition, the rise in sintering temperature dropped the amorphous phase content and increased the mullite content, further enhancing the compressive strength. When the sintering temperature was in the range of 1250 °C–1300 °C and the CaO content was in the range of 2 wt%-4 wt%, the high-strength ceramsite with excellent physicochemical properties could be obtained. It suggested that the synergistic impacts of sintering temperature and CaO improved the performance of ceramsite.

Human fecal alpha-glucosidase activity and its relationship with gut microbiota profiles and early stages of intestinal mucosa damage

ObjectivesWe investigated potential relationships among initial lesions of the intestinal mucosa, fecal enzymatic activities and microbiota profiles. MethodsFecal samples from 54 volunteers were collected after recruitment among individuals participating in a colorectal cancer (CRC) screening program in our region (Northern Spain) or attending for consultation due to clinical symptoms; intestinal mucosa samples were resected during colonoscopy. Enzymatic activities were determined in fecal supernatants by a semi-quantitative method. The fecal microbiota composition was determined by 16S rRNA gene-based sequencing. The results were compared between samples from clinical diagnosis groups (controls and polyps), according with the type of polyp (hyperplastic polyps or conventional adenomas) and considering the grade of dysplasia for conventional adenomas (low and high grade dysplasia). ResultsHigh levels of α-glucosidase activity were more frequent among samples from individuals diagnosed with intestinal polyps, reaching statistical significance for conventional adenomas and for low grade dysplasia adenomas when compared to controls. Regarding the microbiota profiles, higher abundance of Christensenellaceae_R-7 group and Oscillospiraceae_UCG-002 were found in fecal samples displaying low α-glucosidase activity as compared with those with higher activity as well as in controls with respect to conventional adenomas. A relationship was evidenced among intestinal mucosal lesions, gut glucosidase activities and intestinal microbiota profiles. ConclusionsOur findings suggest a relationship among altered fecal α-glucosidase levels, the presence of intestinal mucosal lesions, which can be precursors of CRC, and shifts in defined microbial groups of the fecal microbiota.

Health Risk Assessment from Exposure to Ambient Volatile Organic Compounds (VOCs) at a Truck Tire Factory in the Yangtze River Delta, China

Occupational health risk assessments of exposure to VOCs still need to be extensively studied to improve the safety standards in the industry. Based on the monitoring of organic pollutants at various workstations in a truck tire factory in Jiangsu Province, both semi-quantitative and quantitative health risk assessment methods were employed to assess health risk levels. The findings indicated that VOCs were categorized into five classes, which included alkanes, aromatics, halocarbons, carbon disulfide, and oxygenated volatile organic compounds (OVOCs). The highest concentration of total volatile organic compounds (TVOCs) was found in shaping workshop; alkanes were the most abundant class (74.2%), followed by aromatics (24.02%) and OVOCs (1.96%). Although the results of the semi-quantitative risk assessment showed that most of the organic compounds had low R values, various kinds of VOCs were detected; particularly, many harmful organic compounds (such as toluene, ethyl benzene) were detected in all the sampling sites. The quantitative risk in the calendering and vulcanizing workshop exceeded the acceptable level; both the carcinogenic risk of ethylbenzene in the tire-strip storage room, and trichloroethylene and perchloroethylene in the calendering workshop were unacceptable. Thus, the calendering and vulcanizing processes in rubber tire manufacturing should be priority-controlled processes.

Fosfomycin Susceptibility Among Multidrug-Resistant Extended-Spectrum β-Lactamase and Metallo-β-Lactamase–Producing Uropathogens in a Tertiary Care Hospital

Background Urinary tract infections (UTIs) affect an estimated 150 million people each year worldwide involving women more than men. Because of unrestricted use of antimicrobials and accelerating antimicrobial resistance, therapeutic options for treatment of UTIs are becoming limited. Fosfomycin, a broad-spectrum, rapidly absorbable, antimicrobial agent with good bioavailability and substantial activity against multidrug-resistant (MDR) isolates has antimicrobial activity against a substantial percentage of these MDR isolates. Methods A cross-sectional study over a period of 20 months on urine samples of all patients of all age groups clinically suspected of UTI was conducted in a tertiary care center of southern Rajasthan. Samples were processed immediately as per standard microbiological techniques, followed by culture by a semiquantitative method and antimicrobial susceptibility testing using the Kirby-Bauer disk diffusion method. All gram-negative pathogens were screened for extended-spectrum β-lactamase and further metallo-β-lactamase production using standard disk diffusion tests. Results Of the 1858 positive samples isolated, the most common uropathogen was Escherichia coli (59.96%), with 8.97% confirmed extended-spectrum β-lactamase–producing isolates. Fosfomycin had susceptibility of 96.69%, with its sensitivity and specificity being 98.15% and 6.98% more than nitrofurantoin, respectively. Among the metallo-β-lactamase producers, fosfomycin had susceptibility of 78.58%, with sensitivity and specificity being 91.67% and 25% more than nitrofurantoin, respectively. Conclusion With an increasing threat due to MDR uropathogens in both hospitals and in the community, fosfomycin, with its unique mechanism of action, appears to be a better oral, effective, and safe therapeutic option and a viable potential alternative over other drugs for treatment of UTIs.

Obesity Is Associated with Asymptomatic Vertebral Fractures: A Yakumo Study.

(1) Background: Patients with primary vertebral fracture (VF) are at high risk of re-fracture and mortality. However, approximately two-thirds of patients with VFs receive minimal clinical attention. (2) Methods: The current study aimed to investigate the factors associated with asymptomatic VFs in middle-aged and elderly individuals who underwent resident health examinations. (3) Results: The current study included 217 participants aged > 50 years. VFs were diagnosed based on lateral radiographic images using Genant's semiquantitative (SQ) method. The participants were divided into non-VF (N; SQ grade 0) and asymptomatic VF (F; SQ grades 1-3) groups. Data on body composition, blood tests, quality of life measures, and radiographic parameters were assessed. A total of 195 participants were included in the N group (mean age, 64.8 ± 7.8 years), and 22 were in the F group (mean age, 66.1 ± 7.9 years). The F group had a significantly higher body mass index (BMI), body fat percentage (BF%), and proportion of patients with knee osteoarthritis (KOA) than the N group. The F group had a significantly higher knee joint pain visual analog scale (VAS) score and painDETECT score than the N group. Logistic regression analysis showed that BF% was associated with asymptomatic VFs. (4) Conclusions: Middle-aged and elderly individuals with asymptomatic VF presented with high BMIs, BF%, and incidence of KOA.

Chemical release risk assessment in earthquake: Natech event scenario

IntroductionIn recent decades, an increase in natural disasters has led to the Natech events occurrence, which are technological accidents triggered by natural hazards. This study aims to assess the risk of chemical release of the H2S toxic gas following an earthquake from the refinery. MethodThe Natech risk assessment was carried out in potential earthquake risk scenarios via a semi-quantitative method using Rapid-N software. The reference scenario was obtained using the Australian SMUG Model, which has presented precise prioritization. FindingsThe Natech risk assessment has shown 40 possible earthquake risk scenarios from 5 enclosing Faults in Tehran (North Tehran, Mosha, North Ray, South Ray, and Kahrizak) with an extension of more than 15 km. The earthquake moment magnitudes of 7.5, 7.1, 6.5, and 5.9 were obtained on the Richter scale and at two Focal depths of 5 and 10 km. The South-Ray Fault (HSR-1) was selected as the reference scenario with a moment magnitude of 7.5 on the Richter scale at a Focal depth of 5 km and a distance of 5.5 km from the earthquake epicenter. The highest probability of Natech risk has shown the release of H2S toxic gas in an area with a radius of 6.59 km from the studied vessel in atmospheric stability conditions. ConclusionLegislation in line with risk reduction, planning for the transfer of potentially dangerous industries to outside urban areas, monitoring land use laws, and promoting coordination between the government, industries, and people in the management of risks caused by industries containing hazardous substances and processes, assessing the risk of Natech events and their consequences, strengthening risk communication and the installation of early warning systems, and public education to adopt personal and socially safe behaviors when facing natural disasters are recommended.

Semi-Quantitative Categorization Method for the Corrosion Behavior of Metals Based on Immersion Test

Corrosion processes are complex in nature and their studies have become an interdisciplinary research field, combining fundamental sciences and engineering. As the quantification of corrosion processes is affected by many variables, standard guidelines to study such phenomena had been developed, such as ASME and ISO, and are broadly used in industry and academics. They describe methods to perform immersion test experiments and to quantify the corrosion rates of metals exposed to corrosive environments, but do not provide any guidelines for post-exposure analysis of the as-obtained corroded samples, which might provide useful information to understand the underlying physicochemical mechanisms of corrosion. This knowledge is useful for selecting optimal construction materials and developing corrosion prevention strategies. In this work, a semi-quantitative categorization method of the corrosion behavior of metals exposed to a corrosive medium based on their mass loss and aspect is presented. For each category, the mathematical aspects of gravimetric measurements of mass change rate and the analytical techniques that can be used for the characterization of materials are discussed. The following method does not intend to replace industrial standards, but to expand them in order to maximize the amount of information that can be extracted from immersion tests.

Optical coherence tomography and gray scale digital analysis as noninvasive techniques for evaluating molar-incisor hypomineralization severity: A comparative study with microcomputed tomography.

Molar-incisor hypomineralization (MIH) is a qualitative defect of dental enamel characterized by demarcated opacities present in permanent first molars and other teeth. It is considered a major clinical challenge in dentistry because it makes affected teeth more susceptible to fractures and dental caries. Its diagnosis is mainly clinical and there are few technological resources that allow for a more accurate diagnosis, especially with respect to the depth of the defect in the dental enamel. In this context, optical coherence tomography (OCT), which is routinely used in ophthalmology, can produce images of the depth of the dental enamel, making it a promising method. In this study, 33 teeth with different MIH severities were evaluated using OCT and microcomputed tomography (microCT). Semi-quantitative methods of grayscale pattern analysis were used to compare images obtained from different severities of MIH with the mineral density obtained through microCT. MicroCT evaluation revealed that hypomineralized enamel had a significantly lower mineral density than intact enamel. However, this difference was not observed between the mild and severe MIH lesions. In the OCT evaluation, significant differences were observed between the intact and hypomineralized enamel, and the gray value comparison provided a method for quantitative differentiation between the two. This study suggests that OCT could be a useful adjunct to traditional diagnostic methods for MIH, offering a noninvasive approach to evaluate enamel defects. RESEARCH HIGHLIGHTS: Combining optical coherence tomography with grayscale digital analysis shows potential as a promising method for diagnosing molar-incisor hypomineralization and assessing its level of severity.

Development of a highly sensitive colloidal gold semiquantitative method for the determination of difenoconazole residues in citrus.

Difenoconazole (DIFE) is a common pesticide used in citrus cultivation; excessive intake can cause neurological damage to the organism, and the existing colloidal gold immunochromatographic test strips cannot meet the requirements for the detection of citrus samples. Difenoconazole test strip was prepared based on the colloidal gold immunochromatographic technique (GICT), and its application in citrus samples was investigated; with colloidal gold (CG) as the probe, the optimization of GICT parameters, and the determination of reaction method, the immunochromatographic test strips for the detection of DIFE in citrus was developed, and the limit of detection (LOD), specificity, accuracy, and stability of the test strips were verified. The results showed that the visual detection limit of the prepared colloidal gold immunochromatographic test strips was 0.2 mg/kg and the quantitative range was 0.06-0.6 mg/kg, and the test strips could specifically identify DIFE and have no cross-reaction with other common triazole pesticides. The detection method established in this study was verified by the GC-MS method, and the detection results achieved good consistency (R2 > 0.98). The test strips developed in this study have good performance and can be used for highly sensitive detection of citrus samples.

Semi-quantitative Evaluation Method and Application of Pipeline Geological Risk

Since the 21st century, long oil pipelines have become the arteries of global energy transportation and an important part of social development. With the continuous development and progress of the economy, the construction of long-distance pipelines is the main way to ensure related transportation. With the emergence of long-distance pipeline transportation, people pay more and more attention to the safety problem. In practical work, pipeline transportation is more obvious in geological risks. In this paper, the quantitative evaluation technology of geological hazards of long-distance transportation pipelines is studied.

Identification and quantification of adulteration in frozen-thawed meat of different breeds by NIR spectroscopy and chemometrics

This work aims to compare the characteristic near-infrared absorption bands of different breeds of meats and to develop a qualitative and semi-quantitative method for the detection of adulteration in various types of frozen meat based on near-infrared spectroscopy and chemometrics methods. The adulterated samples were in various combinations of pork, beef and mutton adulterated with different proportions of pork, beef, lamb, duck and chicken. The results showed that the accuracy of the PLS-DA model that identified all adulteration types together was the lowest (AUCP= 0.8265), while the accuracy of the PLS-DA model of lamb-chicken and beef-chicken was the highest (AUCP= 1). AUCP of other adulteration types was higher than 0.92. And the PLSR model constructed by all the adulteration types together had the worst result (Rp2= 0.5348, RMSECV=0.1895, RPD=1.48). The results of PLSR prediction models constructed by the adulteration types separately all reached the expectation (Rp2= 0.8707–0.9703，RMSECV= 0.0637–0.1089，RPD= 2.78–5.80). The results of the PLS-DA models and PLSR models using characteristic band spectral information are basically the same or slightly improved compared with those results of the models using full-band spectral information. Therefore, NIR spectroscopy and chemometrics methods can directly qualitatively identified all adulteration types, but it is more accurate to semi-quantitatively predict the proportion of adulteration according to different adulteration types. The near-infrared absorption of moisture and fat contributed more to the detection of meat adulteration.

Comparison of Tissue Factors in the Ontogenetic Aspects of Human Cholesteatoma.

An acquired cholesteatoma is a benign but locally aggressive lesion in the middle ear. It is characterized by chronic inflammation and the destruction of surrounding bone. Therefore, the aim of this study was to compare defensins HβD-2 and HβD-4; pro- and anti-inflammatory cytokines IL-1α and IL-10; proliferation marker Ki-67; transcription factor NF-κβ; angiogenetic factor VEGF; Sonic hedgehog gene protein SHH; and remodeling factors MMP-2, MMP-9, TIMP-2, and TIMP-4 in adult and pediatric cholesteatoma tissue, and to compare these groups with control skin tissue. The study included 25 cholesteatoma tissue material samples from children, 25 from adults, and 7 deep external ear canal skin samples from cadavers. The tissues were stained immunohistochemically and evaluated using semi-quantitative methods. Nonparametric tests, such as the Kruskal-Wallis test and Spearman rank correlation, were used. There were no statistically discernible differences between the adult and children groups when comparing the relative numbers of factor-positive cells. There are no histopathological differences between adult and children cholesteatoma tissues.

An Exploratory Data Analysis (EDA) Tool for Tracer Selection in Sediment and Pollution Fingerprinting Studies

Tracer selection is a critical step for any mixing model that uses the information of multiple variables to find the most likely solution for sediment or pollution source apportionment. The purpose of this work was to design an Exploratory Data Analysis (EDA) tool for qualitative and quantitative interpretation of tracer selection based on boxplots. This tool establishes a set of conditions presented as a decision tree to support the user in tracer selection decisions where current systems are either too statistically driven, which limits user interaction with the data, or rely too heavily on judgement and prior knowledge of tracer behaviour. This method extends upon the classical “range test” by incorporating a set of conditions and thresholds, creating a semi-quantitative method with a visual component to improve the tracer selection process and enable targeted consideration of geochemical behaviours for conservativism purposes. We present the results from experimental mixtures using the mixing model MixSIAR to demonstrate the method and illustrate the value of this approach for improved tracer selection. The tool, which is written in R, is freely available for use across a wide range of source apportionment applications.

Relationships between Motor Skills and Academic Achievement in School-Aged Children and Adolescents: A Systematic Review.

This review systematically summarizes the studies of the relationship between primary-to-secondary school students' motor skills and academic achievement, and analyzes the relationship between gross and fine motor skills and performance in different subjects. Five electronic databases, Web Of Science, PubMed, PsycINFO, SPORTDiscus, and Academic Search Premier, were searched in March 2023. Semi-quantitative assessment methods were used to analyze the results of the included studies. Seventy-eight articles were included in this systematic review. The semi-quantitative assessment results showed that gross (+, 65.0/62.5%) and fine motor skills (+, 83.3/80%) were positively correlated with overall performance and language performance, with ≥60% of the associations in the same direction. For different subjects, fine motor skills were positively correlated with students' mathematics (+, 75.0%), reading (+, 72.7%), writing (+, 66.7%), and spelling (+, 60.0%) scores. However, the association between gross motor skills and students' mathematics achievement (?, 52.8%), reading (?, 53.8%), and spelling (?, 50.0%) is uncertain, with <60% of the associations in the same direction. It is wise to direct our gaze toward the evolution of motor skills among students, especially primary school students. Different motor skill intervention modes should be selected in a targeted manner according to different subject achievements.

Visual detection of biogenic monoamines based on amine oxidase-peroxidase coupling reaction using ascorbic acid as H2O2 scavenger.

This study represents a visual detection for total biogenic monoamines with naked eye as a simple and rapid semi-quantitative method for biogenic amine monitoring. The equivalent reaction of H2O2 with ascorbic acid resulted in color development by an amine oxidase-peroxidase coupling reaction in the samples containing the biogenic monoamines higher than the subjected ascorbic acid by 10μM. Upon employing the commercial doenjang extracts as a model food, an additional heating step was requested, and the expected ranges for the biogenic monoamines from 360 to 480μM covered the real contents of the samples (360.2-407.3μM). Therefore, this visual detection method makes it possible to decide with naked eye whether the sample contains the biogenic monoamines higher than the ascorbic acid supplemented as much as a control level on manufacturing sites without instrumental analysis.

A semi-quantitative histochemical method for assessment of biochemical responses to osmotic stress in Coffea arabica leaf disks.

A simple method set for assessing biochemical changes associated with osmotic stress responses was developed using coffee (Coffea arabica L.) leaf disks. Stress was induced by polyethylene glycol (PEG) exposure. Quantitative evaluation of tissue physiological stress parameters was carried out using analytical methods to validate the conversion of classic qualitative histochemical tests for localizing lipid peroxidation, hydrogen peroxide, and total xanthine alkaloids into semi-quantitative assays. Relative electrolyte leakage (EL%) and chlorophyll content (SPAD index) were also recorded. EL% levels of treated disks were higher than those of control ones, whereas SPAD indexes were comparable. Histochemical localization indicated that levels of lipid peroxidation, H2O2, and total xanthines were also higher under osmotic stress than in control conditions. Semi-quantitative data obtained by image processing of histochemical staining consistently matched quantitative evaluations. Chromatographic analyses revealed that theophylline and caffeine concentrations increased in the presence of PEG, whereas theobromine remained constant in relation to the control. The methods herein described can be useful to rapidly acquire initial data regarding biochemical osmotic stress responses in coffee tissues based on simple staining and imaging steps. Moreover, it is likely that the same method may be applicable to other types of stresses and plant species upon minor adjustments.