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Identifying the factors that contribute to individual differences in mid-level intensity neuromuscular fatigue is essential to improve performance and effective exercise in training and rehabilitation. This study investigated factors affecting individual differences in knee extensor fatigue induced by sustained isometric mid-level contractions. Twenty-six healthy young men performed a sustained fatiguing contraction to task failure at 40% maximal voluntary contraction (MVC) torque of the knee extensors. The MVC torque (TQMVC), evoked triplet torque (TQTRI), and voluntary activation (VA%) of the knee extensors were determined before and after the fatiguing task. Differences in TQMVC, TQTRI, and VA% before and after the fatiguing task were examined, and the relationship between TQMVC and TQTRI or VA% after the fatiguing task normalized to baseline was examined using Pearson product-moment correlation analysis. TQMVC and TQTRI decreased significantly after the fatiguing task (31.1% decrease for TQMVC, 38.8% decrease for TQTRI, p < 0.001), whereas VA% did not change significantly (4.2% increase for VA%, p = 0.057). After the fatiguing task, the normalized TQMVC was significantly correlated with the normalized TQTRI (r = 0.617, p < 0.001), but not with the normalized VA% (r = 0.348, p = 0.082). Individual differences in knee extensor fatigue induced by sustained mid-level contraction were more affected by peripheral fatigue than by central fatigue. Therefore, focusing on fatigue resistance in peripheral areas is important to improve endurance in moderate-intensity exercises.

The rhodium(I)-catalyzed reaction of alkynes with aryl­boronic acids in the presence of formaldehyde results in a CO-gas-free arylative dual-carbonylation to produce γ-butenolide derivatives. The simultaneous loading of phosphine-ligated and phosphine-free rhodium(I) complexes is required for efficient catalysis. The former complex catalyzes the abstraction of a carbonyl moiety from formaldehyde through the activation of its formyl C–H bond (decarbonylation) and the latter catalyzes the subsequent dual-incorporation of the resulting carbonyl unit (carbonylation). The use of larger amounts of the phosphine-ligated rhodium(I) complex generates more carbonyl units, leading to the formation γ-butenolides via the dual-incorporation of the carbonyl unit.

Organic azides are still in the center of click chemistry connecting two molecules. However, taming the conjugation selectivity of azides is difficult without the help of bulky groups. We report herein the unique reactivities of α-azido secondary acetamides (α-AzSAs) as minimal and unhindered azide structures. The NH–azide interaction in the α-AzSAs, supposed by DFT calculations, allowed selective conjugation in the presence of other azido moieties, even without steric hindrance. With Staudinger–Bertozzi ligation, α-AzSAs underwent conjugation prior to the other primary alkyl azides. On the other hand, in propargyl cation-mediated triazole synthesis, other alkyl azides, including tertiary alkyl azides, underwent the conjugation faster than α-AzSAs. We also demonstrated site-selective integration of the functional components onto the diazide modular hubs.

Objective: The emergence of malaria as a global health problem over the past few decades, accompanied by the rise of chemoresistant strains ofPlasmodium falciparum, has emphasized the need for the discovery of new therapeutic drugs against this disease. In this study, enantiomericallyenriched (enantioenriched) analogs of triclosan were synthesized and evaluated for antimalarial activity against P. falciparum cultures.Methods: Enantioselective dihydroxylation of the olefin in amide seven was performed efficiently using chiral quinine ligand (DHQ)2PHAL to yieldenantioenriched dihydroxy propionamide derivative (+)-1 in moderate yields. In a similar way, the chiral quinidine ligand (DHQD)2PHAL was used asstereoselectivity agent yielded the desired enantioenriched (−)-1. The enantioenriched products were used for further in vitro assay, and accordingly thepercent enantiomeric excess (% ee) was not determined. The structures of compounds were proven by spectral data (1H NMR, 13C NMR, and mass spectra).Results: The phenol moiety at the C1 position of triclosan was chemically substituted with a methoxy group, in conjunction with an introducedstereocenter in a 2,3-dihydroxy-propionamide group at C2’ position. Unmodified triclosan inhibited the P. falciparum cultures with an IC50 value of27.2 μM. By contrast, the triclosan analogs, compounds (+)-1 and (−)-1, inhibited the P. falciparum cultures with IC50 values of 0.034 and 0.028 μM,respectively.Conclusion: Collectively, our preliminary in vitro results suggest that these triclosan analogs have potent antimalarial activity and represent apromising new treatment strategy on further development.

Introduction: Sargassum polycystum is one of marine algal which has a potent antioxidant anticancer activities. This research aims to investigate phytochemical composition, antioxidant activity and in vitro cytotoxicity of marine algal Sargassum polycystum on cervical HeLa cancer. Methods: Sargassum polycystum collected from Dompu beach, Lombok, Nusa Tenggara Barat Province, Indonesia, were extracted into organic solvent of n-hexane, ethylacetate, chloroform and ethanol, respectively. Subsequently, Sargassum polycystum extracts were applied for Thin Layer Chromatography (TLC) analysis, phytochemistry test, total phenolic and total flavonoid contents, as well as for antioxidant activity test by DPPH (2,2-diphenyl-1-picrylhydrazyl) method, and in vitro cytotoxicity evaluation on HeLa cells by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide) assay. Results: Phytochemical analysis of S. polycystum extracts are positive for metabolites of flavonoid, steroid, tannin and glycoside. TLC analysis revealed that S. polycystum extracts containing four phytochemical components. Ethylacetate extract of S. polycystum showed the highest total phenolic content, and exhibited greater antioxidant activity than ethanol extract. Total phenolic and total flavonoid content in ethylacetate extract are 548.61 μg/mL and 40.06 μg /mL, respectively. Ethylacetate extract of S. polycystum with IC50 value of 298.3 μg/mL is assigned to have a weak antioxidant activity against DPPH free radical. The results indicate that antioxidant activity of ethylacetate extracts of S. polycystum is directly correlated with its total phenolic and flavonoid content. Moreover, S. polycystum extracts demonstrated a strong anticancer activity on cervical HeLa cells with IC50 ranging from 38.3 μg/mL to 112.8 μg/mL. Conclusion: This work confirmed that S.polycystum are promising natural antioxidant and anti-cervical cancer agents.

We describe transfer carbonylation reactions of 2-bromoarenes that contain a carbon-nucleophile using aldehydes as a substitute for CO, leading to the formation of indanone derivatives. The transformation proceeds efficiently under RhI /Pd0 -hybrid catalytic conditions consisting of two discrete transition metals, rhodium and palladium, which catalyze the decarbonylation of aldehydes and the subsequent carbonylation of bromoarenes using the resulting carbonyl moiety, respectively. The majority of the abstracted CO is transferred directly to the product via a CO-relay process from rhodium to palladium.

Lithium-ion secondary batteries have been used in a wide variety of purposes, such as for powering mobile devices and electric vehicles, but their performance should be improved. One of the factors that limits their performance is the non-uniformity of the chemical reaction in the process of charging and discharging. Many attempts have been made to elucidate the mechanism behind this reaction non-uniformity. In this paper, to detect non-uniformity in various physical properties from Co K-edge two-dimensional x-ray absorption spectroscopy (2D-XAS) images of lithium ion batteries, we propose a method that consists of one-sided orthogonal non-negative matrix factorization in combination with removal of the reference signal. The difference between x-ray absorption spectra acquired at different positions in the battery is very small. However, even in such a situation, our method can decompose the 2D-XAS data into different spatial domains and their corresponding absorption spectra. From the spectral decomposition of the obtained absorption spectra, we confirmed a transition-energy shift of the main peak as evidence for a change in the state of charge and also found spectral changes due to orbital hybridization in the decomposed spectral components.

We report herein the unique reactivities of α-azido secondary acetamides (α-AzSAs) as minimal and unhindered azide structures. The NH–azide interaction in the α-AzSAs, supposed by DFT calculation, allowed selective conjugation in the presence of other azido moieties. With Staudinger-Bertozzi ligation, α-AzSAs proceeded the conjugation prior to the other primary alkyl azides. On the other hand, in propargyl cation-mediated triazole synthesis, other alkyl azides, including tertiary alkyl azides, underwent the conjugation faster than α-AzSAs. We also demonstrated discriminative integration of the functional components onto the diazide modular hubs.

We report herein the unique reactivities of α-azido secondary acetamides (α-AzSAs) as minimal and unhindered azide structures. The NH–azide interaction in the α-AzSAs, supposed by DFT calculation, allowed selective conjugation in the presence of other azido moieties. With Staudinger-Bertozzi ligation, α-AzSAs proceeded the conjugation prior to the other primary alkyl azides. On the other hand, in propargyl cation-mediated triazole synthesis, other alkyl azides, including tertiary alkyl azides, underwent the conjugation faster than α-AzSAs. We also demonstrated discriminative integration of the functional components onto the diazide modular hubs.

We describe the effective rhodium(I)-catalyzed [2+2+1] carbonylative cycloaddition of diynes, yielding cyclopentadienes (CPDs), under photoirradiation. The catalysis involves the promotion of the photodissociation of the product CPD, with the simultaneous production of an essential vacant coordination site on the rhodium for an unreacted substrate. The combined use of cationic [Rh(cod)2]BF4 as a catalyst and photoirradiation was also found to give various CPDs in high yields (≤96%).

In this work, the [2+2] photocycloaddition of carbonyl compounds with olefins, the Paterno-Buchi-type photoreaction, was performed in a flow microreactor under slug flow (two-phase flow) conditions...

This paper reports the selective conversion of alkyl azido groups at the carbonyl α-position into oximes through β-elimination of dinitrogen, followed by transoximation. With this method and diazo conversion, a triazido molecule was transformed into a triple click conjugation scaffold allowing one-pot four-component coupling.

Schmidt reaction by sulfonium ions is described. General primary, secondary, and tertiary alkyl azides were converted to the corresponding carbonyl or imine compounds without any trace of the activators. This bond scission reaction showcased ring-opening, -expansion, and one-pot further conversion of the substrates as well as the application with C-H azidation.

Although the influence of the series elastic element of the muscle–tendon unit on jump performance has been investigated, the corresponding effect of the parallel elastic element remains unclear. This study examined the relationship between the resting calf muscle stiffness and drop jump performance. Twenty-four healthy men participated in this study. The shear moduli of the medial gastrocnemius and the soleus were measured at rest as an index of muscle stiffness using ultrasound shear wave elastography. The participants performed drop jumps from a 15 cm high box. The Spearman rank correlation coefficient was used to examine the relationships between shear moduli of the muscles and drop jump performance. The medial gastrocnemius shear modulus showed a significant correlation with the drop jump index (jump height/contact time) (r = 0.414, P = 0.044) and jump height (r = 0.411, P = 0.046), but not with contact time (P > 0.05). The soleus shear modulus did not correlate with these jump parameters (P > 0.05). These results suggest that the resting medial gastrocnemius stiffness can be considered as one of the factors that influence drop jump performance. Therefore, increase in resting muscle stiffness should enhance explosive athletic performance in training regimens.

Gallic acid is a phenolic compound distributed in plants and fruits which has been reported to have cytotoxic effect on MCF-7 breast cancer cell line. In this research, we investigated in vitro cytotoxic effect of six synthesized compounds of gallic acid derivatives (N-alkyl gallamide), namely N-methyl gallamide (2); N-ethyl gallamide (3); N-butyl gallamide (4); N-sec-butyl gallamide (5); N-tert-butyl gallamide (6) and N-hexyl gallamide (7) against breast MCF-7 cells by MTT assay. Linear regression analysis is utilized to analyze data to regenerate IC50 value. The results will be compared with gallic acid as an original compound and doxorubicin as a positive control.Among six synthesized compounds, N-tert-butyl gallamide (6) with IC50 value of 2.1 µg/mL, and N-hexyl gallamide (7) with IC50 value of 3.5µg/mL,showed the stronger cytotoxicity against breast MCF-7 cells compared to gallic acid and doxorubicin. Thus,N-tert-butyl gallamide (6) and N-hexyl gallamide (7) are potential to be further developed as a promising anti-breast cancer agents.

The synthesis and characterization of a 'complete set' of positional isomers of tetrakis(perfluorophenyl)porphyrins (TFPP)-glucose conjugates (1OH, 2OH, 3OH, 4OH, and 6OH) are reported herein. The cellular uptake and photocytotoxicity of these conjugates were examined in order to investigate the influence of location of the TFPP moiety on the d-glucose molecule on the biological activity of the conjugates. An In vitro biological evaluation revealed that the certain of these isomers have a greater effect on cellular uptake and cytotoxicity than others. The TFPP-glucose conjugates 1OH, 3OH, and 4OH were found to exert exceptional photocytotoxicity in several types of cancer cells compared to 2OH and 6OH substituted isomers.

Nitrosoallene-mediated endo-dig cyclization reactions producing (hetero)cyclic exo-unsaturated oximes (enoximes) are described. The intramolecular 1,4-type addition to in situ generated nitrosoallenes afforded α-substituted cyclic enoximes with exo-methylene units, which are the favored conformation for further cyclizations. The strong electron-withdrawing ability of the nitroso group facilitated the construction of five-to-seven-membered ring systems via C-O, C-N, C-S, and C-C bond formations, including a quaternary carbon center, at low temperatures.

In spite of the significant progress made in transformations of unstrained benzylic (tert-)alcohols through β-aryl elimination, catalytic carbonylation has not yet been developed extensively because alkoxycarbonylation is probably favored over β-aryl elimination. In this letter, we report on the rhodium(I)-catalyzed carbonylative annulation of α,α-dimethyl-(2-bromoaryl)methanols with internal alkynes using furfural leading to the formation of indenones. The key to the success of the reaction is the timely generation of the carbonyl source via the decarbonylation of furfural.

The rhodium(I)-catalyzed carbonylative annulation of iodobenzenes with strained olefins in the presence of furfural as a carbonyl source, accompanied by ortho-C–H bond cleavage, is reported. The use of 4-octyne in place of strained olefins also leads to the formation of the corresponding inden-9-one. The timely release of the carbonyl moiety via the rhodium-catalyzed decarbonylation of furfural plays a decisive role in this reaction.

We herein describe the syntheses and characterization of extended germa[N]pericyclynes, which are macrocycles composed of germanium-butadiyne units. The obtained novel extended germa[4]-[8]pericyclynes were characterized by X-ray crystallography, UV-Vis spectroscopy, fluorescence and phosphorescence emission spectroscopy, and cyclic voltammetry, and exhibited characteristic absorptions and emissions. Density functional theory (DFT) calculations suggested smaller HOMO-LUMO gap energy compared to that of general germapericyclynes.

In this study, novel caged antisense oligonucleotides with thiochromone S,S-dioxide as the photolabile protecting group were synthesized, and their photodeprotection was investigated. In vitro experiment, the original target molecule was successfully recovered by photoirradiation. Furthermore, the photodeprotection process was also successfully monitored by the fluorescence spectroscopy of highly fluorescent byproducts generated from the thiochromone-type photolabile protecting group.

This study investigated the acute effect of active recovery (AR) following fatigue induced by 80 three-second maximal voluntary isometric plantar flexion contractions (MVICs) in 12 young men. AR consisted of a total of 180 voluntary isometric ramp contractions of the plantar flexors (0.75-s contraction/relaxation) targeting 10% of MVIC torque. MVIC torque, voluntary activation and root mean square values of electromyographic signals for the triceps surae normalized by each peak-to-peak amplitude of compound motor action potential were determined before, and immediately, 10, 20 and 30 min after the fatiguing task. Evoked torques were similarly assessed except for immediately after it. The AR and passive recovery were randomly performed on two days by each participant between 5 min and 10 min after the fatiguing task. For all the parameters other than MVIC torque, there was no significant difference between the conditions at any time point. MVIC torque decreased significantly immediately after the fatiguing task regardless of condition (P 0.05), and the corresponding decrease in MVIC torque recovered 30 min after the fatiguing task only in AR (P 0.05). These results suggest an acute positive effect of AR on recovery of neuromuscular function and/or contractile properties after fatigue.

A new and efficient thiochromenone S , S -dioxide-based photolabile protecting group for propargylic alcohols is described. Robust protection reactions were developed through copper (II)-catalyzed substitution of propargylic alcohols. Subsequent photodeprotection proceeded smoothly to give the corresponding propargylic alcohols quantitatively within 15 minutes, as demonstrated by 1 H NMR spectroscopy and HPLC. Notably, the photoproduct derived from the thiochromenone derivatives showed a high fluorescence quantum yield, permitting monitoring of the reaction progress by fluorescence spectroscopy. A new strategy for the synthesis of triazoles by a one-pot reaction is also presented.

A typical (Paterno-Buchi type) organic photoreaction is examined in flow microreactors. Compared to the results achieved for simple one-layer flow modes, slug flow conditions (with the unreactive reagent composed of organic solution and water) achieve higher efficiency (conversion and yield) irrespective of the light source, concentration, and solvent. Furthermore, remarkably high productivity is also observed when only 5% water is added as an unreactive reagent. This method is broadly applicable for achieving highly efficient organic photoreactions not only in the laboratory, but also on the industrial scale.

This study investigated the effects of cooling the triceps surae with carbon dioxide hydrate (CDH), which is a gas hydrate, a crystalline structure belonging to the clathrates, on the recovery from muscle fatigue. Thirty-six healthy young men were equally and randomly assigned to an ICE group, a CDH group, or a non-cooling (NON) group. All participants performed 80 maximal voluntary isometric contractions (MVCs) of the plantar flexors as a fatiguing task. MVC torque and voluntary activation were determined before, immediately after, and 20 min after the fatiguing task. Evoked torque was similarly assessed except for immediately after the task. In the ICE and CDH groups, the triceps surae was cooled for 5 min using ice and CDH, starting 5 min after the fatiguing task, respectively. The MVC torque and voluntary activation were higher in order of before >20 min after >immediately after the fatiguing task regardless of group, and those time-course changes did not differ between the groups. A decrease in the evoked torque from before to 20 min after the fatiguing task was observed in the ICE and NON groups but not in the CDH group. These results suggest that cooling muscle with CDH can facilitate recovery from peripheral muscle fatigue. This may be due to an increase in blood flow caused by carbon dioxide contained within the CDH, and indicates the potential of CDH as a recovery tool after fatiguing exercise.

A dual neutral-cationic rhodium(I)-catalyzed Pauson–Khand-type reaction using formaldehyde as a carbonyl source is described. The simultaneous use of neutral rhodium(I) and cationic rhodium(I) complexes is required for efficient cooperative catalysis, which involves the neutral rhodium(I)-catalyzed decarbonylation of formaldehyde and the cationic rhodium(I)-catalyzed cyclocarbonylation of 1,6-enynes using the resulting carbonyl moiety.

Synthesis and optical properties of skipped polyynes comprising germanium–acetylene units are presented. The prepared germanium polymers were investigated by UV-vis, fluorescence, and phosphorescence spectroscopy and DFT calculations. The optical properties were compared to those of cyclic compounds, germa[N]pericyclynes. The unique fluorescence and phosphorescence behaviours of acyclic polymers were observed.

The diastereodifferentiating [2+2] photocycloaddition of a chiral cyclohexenone with cyclopentene was performed in supercritical carbon dioxide (scCO2) using a flow microreactor. In all cases examined, the microreactor gave higher conversions than the batch system because of the very short path length of the microreactor. Additionally, by using the microreactor, accurate temperature control produced higher diastereoselectivity. These distinguished findings can be attributed to the synergistic effect of superior light penetration in the microreactor and the unique solvent property (clustering effect) of scCO2.

We describe the full details of multicomponent coupling reactions in acid-mediated synthesis of fully substituted 1,2,3-triazoles syntheses, and their applications to bioactive molecule synthesis. For substitution with wide range of nucleophiles, selection of acids or activating reagents was important, and various types of multicomponent coupling reactions were demonstrated, allowing functionalization with alcohols, amines, thiol, azide, and carbon nucleophiles. Four-component couplings including double triazolations were also tested. The efficiency of this method was demonstrated by the synthesis of serine hydrolase inhibitor and its novel substituted derivatives.

This paper presents the synthesis and characterization of (TMS-ethynyl)-substituted germa[4]pericyclyne composed of acetylene moieties and germanium atoms. Characterization was performed by X-ray crystallography, UV–vis absorption, and photoluminescence spectroscopy. DFT calculations suggested interactions between the side chain alkynes and the ring-forming acetylenes through germanium vertex atoms.

Paraformaldehyde serves as a carbonyl source in the Pd-catalyzed cyclocarbonylation of 2-bromobiphenyls through the cleavage of a C–H bond to afford good yields of fluoren-9-one derivatives. This p...