Syntheses of guanidino alkaloids (-)-monanchoradin A and (-)-crambescin A2 392 are described. The key feature of the syntheses is the cyclization-carbonylation-cyclization cascade of the optically active propargyl guanidine. The bicyclic guanidino cores bearing an asymmetric center and ester or carboxylic acid functionality were constructed in a single step.
View Article and Find Full Text PDFImmune cell delivery using injectable hydrogel attracts much attention for improving its therapeutic effect. Specifically, dendritic cells (DCs) are the trigger cells for immune responses, and DC vaccines are studied for improving cancer immunotherapy. Hydrogel-assisted cell delivery is expected to enhance the viability of the implanted cells.
View Article and Find Full Text PDFUtilization of well-defined siloxane molecules allows for the construction of functional siloxane-based nanoporous materials based on the molecular design. Herein, a novel class of siloxane-based porous materials is synthesized via cross-linking of dimethylsilyl- and dimethylvinylsilyl-functionalized cage siloxanes with double-6-ring (D6R) geometry. Compared with the conventional double-4-ring cage siloxane, this study highlights the characteristics of D6R siloxanes as building blocks, demonstrating their high surface area and chemical stability.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
March 2024
Topological gels possess structures that are cross-linked only via physical constraints; ideally, no attractive intermolecular interactions act between their components, which yields interesting physical properties. However, most reported previous topological gels were synthesized based on supramolecular interlocked structures such as polyrotaxane, for which attractive intermolecular interactions are essential. Here, we synthesize a water-soluble "molecular net" (MN) with a large molecular weight and three-dimensional network structure using poly(ethylene glycol).
View Article and Find Full Text PDFDeveloping delivery vehicles that achieve drug accumulation in the liver and transferability into hepatic stellate cells (HSCs) across the liver sinusoidal endothelium is essential to establish a treatment for hepatic fibrosis. We previously developed hyaluronic acid (HA)-coated polymeric micelles that exhibited affinity to liver sinusoidal endothelial cells. HA-coated micelles possess a core-shell structure of self-assembled biodegradable poly(l-lysine)--poly(lactic acid) AB-diblock copolymer (PLys--PLLA), and its exterior is coated with HA through polyion complex formation via electrostatic interaction between anionic HAs and cationic PLys segments.
View Article and Find Full Text PDFPolyinosinic-polycytidylic acid (poly I:C) is a type of pathogen-associated molecular pattern that can strongly induce the expression of type I interferon (I-IFN). Our previous study has demonstrated that the combination of poly I:C with a recombinant protein antigen not only stimulated the expression of I-IFN but also conferred protection against Edwardsiella piscicida in the Japanese flounder (Paralichthys olivaceus). In this study, our aim was to develop a better immunogenic and protective fish vaccine, for which we intraperitoneally coinjected P.
View Article and Find Full Text PDFObjective: Tourette syndrome (TS) is a neurobehavioral disorder characterized by motor and vocal tics. Simple tics are purposeless involuntary movements that spontaneously resolve during middle adolescence. Complex tics appear to be semi-voluntary movements that may become intractable when associated with obsessive-compulsive disorder (OCD).
View Article and Find Full Text PDFHerein, we designed and synthesized a thermally stable carboxybetaine copolymer with a one- or three-carbon spacer between ammonium and carboxylate groups (CBMA1 and CBMA3) to create an anti-nonspecific adsorption surface with the ability to immobilize antibodies. A series of controlled poly(,-dimethylaminoethyl methacrylate) was successfully prepared using reversible addition-fragmentation chain-transfer (RAFT) polymerization and was derived to carboxybetaine copolymers of poly(CBMA1--CBMA3) [P(CBMA1/CBMA3)] with various CBMA1 contents, including the homopolymers of CBMA1 and CBMA3. Thermal stability of the carboxybetaine (co)polymers was higher than that of the carboxybetaine polymer with a two-carbon spacer (PCBMA2).
View Article and Find Full Text PDFWater in a crosslinked dextran gel, Sephadex G25, is known to remain partially unfrozen during cooling and undergoes ice crystallization during rewarming. However, the mechanism of ice crystallization during rewarming is still unclear. To elucidate the frozen state of water in the gel, thermal behavior at low temperatures was investigated by using adiabatic calorimetry.
View Article and Find Full Text PDFUnderstanding the structure and wettability of monolayer water is essential for revealing the mechanisms of nucleation, growth, and chemical reactivity at interfaces. We have investigated the wetting layer formation of water (ice) on the graphite (0001) surface using a combination of low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). At around monolayer coverages, the LEED pattern showed a (2 × 2) periodicity and STM revealed a hydrogen-bonded hexagonal network.
View Article and Find Full Text PDFRed sea bream iridovirus (RSIV) is the pathogen that causes red sea bream iridoviral disease. It causes a huge loss to the Japanese aquaculture industry. In 2021, outbreaks of red sea bream iridovirus occurred in South Japan.
View Article and Find Full Text PDFHyaluronic acid (HA)-coated biodegradable polymeric micelles were developed as nanoparticulate vaccine delivery systems to establish an effective nasal vaccine. We previously reported HA-coated micelles prepared by forming a polyion complex (PIC) of poly(L-lysine)--polylactide (PLys--PLA) micelles and HA. The HA-coated micelles exhibited specific accumulation in HA receptor-expressing cells and extremely high colloidal stability under diluted blood conditions.
View Article and Find Full Text PDFThe basal ganglia(BG)is composed of four parallel loops: the motor, oculomotor, associative, and limbic loops. The motor loop starts from the cortex, travels through the BG and thalamus, and returns to the same area of the cortex with somatotopic organization. The striatum is the major input nucleus of the cortex, and the internal segment of the globus pallidus(GPi)is the main output nucleus.
View Article and Find Full Text PDFPrevious studies have reported that the reduced scattering coefficient (μ') in the vastus lateralis changes during ramp-incremental exercise due to blood volume changes or accumulation of metabolic by-products. We aimed to clarify the influences of deoxygenation and blood volume changes during exercise on μ' dynamics in subjects with various aerobic capacities. Twenty-three healthy young men participated in this study.
View Article and Find Full Text PDFThe primary symptom in patients with chronic heart failure (CHF) is exercise intolerance. Previous studies have reported that reduced exercise tolerance in CHF can be explained not only by cardiac output (a central factor) but also by reduced skeletal muscle aerobic capacity (a peripheral factor). Although exercise training in CHF improves exercise tolerance, few studies have evaluated the effects of exercise training on each specific central and peripheral factor in CHF.
View Article and Find Full Text PDFObjective: We report a case of sustained atypical myokymia associated with short bursts of neuromyotonic discharges involving the abductor pollicis brevis (APB) muscle and describe a useful way of detecting a focal slowing involving a small number of median nerve motor fibers with a concentric needle using the filter setting for single fiber electromyography (EMG).
Methods And Results: A 62-year-old woman developed right thumb twitches at regular interval of 1.7-3.
Purpose: Near-infrared spectroscopy (NIRS), performed with a commonly available noninvasive tissue oxygenation monitoring device, is based on the modified Beer-Lambert law (MBLL). Although NIRS based on MBLL (NIRSMBLL) assumes that the optical path length (PL) is constant, the effects of changes in PL during exercise on muscle oxygenation calculated by MBLL are still incompletely understood. Thus, the purposes of this study were to examine the changes in optical properties during ramp incremental exercise and to compare muscle oxygen dynamics measured by time-resolved NIRS with those calculated based on MBLL.
View Article and Find Full Text PDFBackground: Severe intractable tics, which are associated with Tourette syndrome and chronic tic disorder (TS/CTD), severely affect the quality of life. Common less-invasive treatments are often unable to attenuate tics with deep brain stimulation currently being the only effective treatment. We aimed to assess the anti-tic effect of deep slow nasal respiration with tight lip closure using patients with TS/CTD.
View Article and Find Full Text PDFStimuli-responsive materials have been actively researched over the past few decades. Among such materials, spiropyran is one of the most attractive compounds because the structure and polarity of the material are dramatically changed after photo irradiation, unlike other materials. In this work, we designed and synthesized a spiropyran derivative (SpMA) with a methacryloyl group on the nitrobenzene ring of a spiropyran skeleton.
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