Kyushu Tokai University

ABSTRACT This paper investigates the robust finite‐time control for uncertain discrete‐time singular systems with nonlinear repeated scalars and Markovian jump parameters. By employing the implicit function theorem and Lyapunov function approaches, sufficient conditions are derived to guarantee the regularity, causality, uniqueness of solutions in the neighborhood of the origin, singular stochastic finite‐time stabilization, and singular stochastic finite‐time stabilization for the addressed systems. According to the descriptor system approach, solvability criteria for these control problems are also established, which can be effectively converted into linear matrix inequalities. Additionally, the correctness and feasibility of the proposed method are demonstrated by numerical examples.

Abstract Cultivation as a summer annual grass in temperate regions of new extremely late‐maturing guineagrass cultivar “Umaku” without heading with fertilizer application entails risks of toxic nitrate nitrogen (nitrate‐N) concentration in the grass. No report has described a study of nitrate‐N in guineagrass without heading cultivated as an annual grass in temperate regions. Therefore, for two years, we clarified nitrogen fertilizer effects on dry matter yield (DMY), nutritional values and nitrate‐N concentration in Umaku without heading cultivated as a summer annual grass. Subsequently, we evaluated management strategies aimed at optimizing nitrogen application to enhance DMY and crude protein (CP) content without increasing nitrate‐N. Treatments were factorial combinations of two basal fertilizer applications (10 or 20 g N/m 2 , respectively, as S or D treatment) and two grasses (“Umaku” and “OKI‐1” of Urochloa hybrid as a control) in a randomized complete block design with three replicates. Although differences between years in all measurements were significant, CP and nitrate‐N for the D treatment were significantly higher than for the S treatment. Nitrate‐N values of both grasses exceeded the toxic thresholds (0.2% DM) in all except for the S treatment of 2020. Delaying harvest until after a sufficient yield has been attained is suggested as an effective strategy for suppressing nitrate‐N concentrations. For Umaku, approximately 620 g/m 2 of DMY with 10 g N/m 2 fertilizer application and at least 800 g/m 2 of DMY with 20 g N/m 2 fertilizer application are recommended. The derived relation between total nitrogen and nitrate‐N well demonstrated that cultivation as annual summer grass without heading carries a risk of toxic nitrate‐N concentration (0.2% DM) when the supplied nitrogen fertilizer is intended to achieve a CP content exceeding 9%. However, because of our limited dataset, further data accumulation is necessary. Furthermore, measuring nitrate‐N concentrations at the time of harvesting on farm is required for preventing nitrate‐N poisoning.

Three new acylated glycosidic acid methyl esters and one known compound were isolated by treating the crude resin glycoside fraction derived from the seeds of Ipomoea lacunosa with indium(III) chloride in methanol, and their structures were elucidated using spectroscopic methods. The new compounds contained methyl 3S,11S-dihydroxytetradecanoate as the aglycone. Two were hexaglycosides and one was a nonaglycoside, with saccharide cores partially acylated by a glycosidic acid, 7S-hydroxydecanoic acid 7-O-β-d-quinovopyranoside (quamoclinic acid B), and/or organic acids, including isobutyric and 2S-methylbutyric acids. Furthermore, the cytotoxic activities of the isolated compounds against HL-60 human promyelocytic leukemia cells were evaluated, and they exhibited moderate activities.

Oxidative and glycation stress are interrelated pathological processes that significantly contribute to the development and progression of chronic diseases, including diabetes, chronic kidney disease, cardiovascular disorders, and neurodegenerative conditions. These processes alter biomolecules by generating reactive oxygen species (ROS), reactive nitrogen species (RNS), and advanced glycation end products (AGEs), thereby amplifying cellular dysfunction. Therefore, precise monitoring of these biomarkers is essential for understanding disease mechanisms and for clinical assessments. Conventional methods, such as chromatography, mass spectrometry, and immunoassays, provide high sensitivity and specificity; however, their extensive clinical application is restricted owing to their high cost, labor intensity, and equipment requirements. In contrast, emerging electrochemical and optical biosensor technologies offer advantages in terms of rapidity, portability, and real-time analysis and hold promise for point-of-care (POC) testing and integration into wearable devices. This review systematically summarizes the detection principles and clinical applications of oxidative and glycation stress-related biomarkers and highlights the need for integrated monitoring systems that can simultaneously capture both processes. Advances in these technologies are expected to contribute significantly to early diagnosis, risk stratification, and implementation of personalized medicine.

The present study evaluated the larvicidal and pupicidal activities of pure and mixed monoterpene formulations-eucalyptol, geranial, trans-anethole, and trans-cinnamaldehyde-against Aedes aegypti and compared them with 1% (w/w) temephos. Safety bioassays of all formulations on non-target species confirmed their safety. The combined mixture of eucalyptol + trans-anethole at 400 µg/mL exhibited stronger larvicidal activity, with an LC50 of 176 µg/mL, while the combination of trans-anethole + geranial at 400 µg/mL exhibited stronger pupicidal activity with an LC50 of 167 µg/mL. Both formulations were more effective than a 1% temephos. All the mixture formulations were more strongly synergistic compared to pure formulations, with an increased mortality value (IMV) of 25% to 95%. External morphological aberrations observed at death included swelling of the respiratory system. Importantly, all the formulations were safe for two non-target species: guppies (Poecilia reticulata) and honeybees (Apis mellifera). The combination formulations are strong larvicides and pupicides for controlling Ae. Aegypti, which will help reduce the spread of viruses carried by this vector.

Eight new resin glycosides, named calyhedins XXIV (1)–XXXI (8), were isolated from the rhizomes of Calystegia hederacea Wall. (Convolvulaceae), along with six known calyhedins: calyhedins II (9), III (10), IV (11), V (12), VIII (13), and XII (14). Their structures were determined from the spectroscopic data. Compounds 1–7 were hexa- or hepta-glycosides with macrolactone structures (jalapins), and their sugar moieties were partially acylated by five organic acids, including 2S-methylbutyric, (E)-2-methylbut-2-enoic, and 2R-methyl-3R-hydroxybutyric acids. Compounds 1–7 were macrolactones with 22- (1, 7), 23- (2), 27- (3–5), or 28- (6) membered rings. Compound 8 was identified as an acylated glycosidic acid methyl ester, corresponding to the compound in which the lactone ring of 1 was cleaved and subsequently methylated. In addition, the cytotoxic activities of 1–8, 11, 12, and 14 against HL-60 human promyelocytic leukemia cells and the antiviral activities of 1–14 and 11 previously isolated calyhedins against herpes simplex virus type 1 (HSV-1) were evaluated. Except for 1, the other ten tested compounds exhibited cytotoxicity against HL-60 cells, with the IC50 values of 3, 4, 6, 7, 11, and 12 being closer to or rather lower than that of the positive control cisplatin. Additionally, all tested compounds demonstrated anti-HSV-1 activity, with seven compounds, i.e., 3, 6, 9, 10, 22, 23, and 24, having EC50 values lower than or comparable to that of the positive control acyclovir.Graphical abstract

Advanced glycation end-products (AGEs) have been extensively studied because of their close association with the onset and progression of diabetic complications. However, owing to their formation through diverse metabolic pathways, AGEs often reflect a wide range of pathological conditions rather than being specific to diabetic complications. Consequently, identifying an AGE that directly correlates only with diabetic complications remains a challenge. Chronic hyperglycemia not only saturates the glycolytic pathway but also upregulates the polyol pathway, leading to the excessive production of fructose, a highly reactive reducing sugar. Although it has long been understood that fructose-derived AGEs contribute to diabetic complications, their chemical structures remain unidentified. Recent breakthroughs have revealed that glucoselysine (GL) is a primary fructose-specific AGE. Unlike other AGEs, GL is exclusively formed from fructose and not from other reducing sugars, such as glucose or galactose. This specificity provides GL with a distinct advantage in that its production pathway can be traced, making it a reliable indicator of polyol pathway activity. Furthermore, emerging evidence suggests that GL levels correlate with the progression of diabetic complications, including both micro- and macrovascular complications, making it a promising biomarker. GL's potential extends beyond diagnostics, as it may serve as a therapeutic target for managing complications associated with prolonged hyperglycemia and enhanced of polyol pathway. This review focuses on the enhanced polyol pathway and the formation of GL and discusses its biochemical characteristics, clinical significance, and potential as a novel diagnostic marker and therapeutic target in diabetic care.

Succination is a non-enzymatic post-translational modification of cysteine (Cys) residues, resulting in the formation of S-(2-succino)cysteine (2SC). While hundreds of 2SC-modified proteins have been identified and are associated with the dysfunction of proteins, the underlying molecular mechanisms remain poorly understood. Conventional methods for synthesizing succinated compounds, such as 2SC, often require prolonged reaction times and/or HCl hydrolysis. In this study, we present a rapid and efficient synthesis method for succinated compounds using maleic anhydride, enabling more effective in vivo studies of succination mechanisms. This method was tested on thiol compounds with varying molecular weights, including Cys derivatives, Cys-containing peptides, and reduced bovine serum albumin. By incubating these compounds in an aqueous buffer with maleic anhydride dissolved in an organic solvent like diethyl ether, we achieved significantly improved succination efficiency compared to conventional methods. The succination efficiency using maleic anhydride surpassed that of fumaric acid or maleic acid. Notably, this approach facilitated the succination of amino acids, peptides, and proteins within minutes at 25 °C, without requiring acid hydrolysis. Our findings provide a straightforward, time-efficient strategy for synthesizing succinated thiol compounds, offering a valuable tool to enhance the understanding of succination's molecular mechanisms and its role in protein function and dysfunction.