Publications by authors named "Kenichiro Nakashima"

The discovery of hidden laws in data is the core challenge in many fields, from the natural sciences to the social sciences. However, this task has historically relied on human intuition and experience in many areas, including psychology. Therefore, discovering laws using artificial intelligence (AI) has two significant advantages.

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We report the different properties of two types of red fluorescent proteins (RFP), undescribed species, extracted from two octocorals, Scleronephthya sp. 1 (S. sp.

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Objective: The transition from school to the workforce is important for concrete future planning. During this period, people are more likely to experience psychological health problems, such as anxiety and feelings of hopelessness and helplessness. In particular, job hunting in individuals with low socioeconomic status (SES) leads to various impulsive behaviors and physical and psychological problems due to a scarcity of economic and time resources.

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We examined the factorial structure and validity of a Japanese version of the Parental Burnout Assessment, the PBA-J, with 1,500 Japanese parents. The Parental Burnout Assessment measures burnout using four dimensions: exhaustion in one's parental role, contrast in parental self, feelings of being fed up, and emotional distancing. Confirmatory factor analysis on the PBA-J supported a four-factor model.

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We developed a novel assay using high-performance liquid chromatography (HPLC) with fluorescence detection for the determination of tocilizumab (TCZ), after it has undergone a facile and rapid pretreatment. TCZ belongs to the same subclass as IgG1 (Immunoglobulin G subclass 1), and we could separate TCZ from IgG1 without antigen-antibody reactions, with the novel detection method. The separation of these antibodies was achieved by pretreatment with an organic solvent containing a base, such as trimethylamine and triethylamine.

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Functional triterpenic acids such as ursolic acid (UA), oleanolic acid (OA) and betulinic acid (BA) are representative ingredients in rosemary that may have health benefits. UA, OA and BA in rosemary extracts were derivatized with 4-(4,5-diphenyl-1H-imidazole-2-yl)benzoyl chloride (DIB-Cl) and detected using HPLC-fluorescence (FL). Dried rosemary (50 mg) was ground, added to 3 ml of ethanol, sonicated for 40 min, then the sample solution was added to a mixture of 1% trimethylamine and 1 mM DIB-Cl in acetonitrile.

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Description: Design methods of nanoparticle formulations are divided into break-down methods and build-up methods. The former is further divided into dry and wet processes. For drug nanoparticle preparations, the wet process is generally employed, and organic solvents are used in most formulations.

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Nanoparticle suspensions are thermodynamically unstable and subject to aggregation. Freeze-drying on addition of saccharides is a useful method for preventing aggregation. In the present study, tetrasaccharides (stachyose) was employed as an additive.

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Previous studies have argued that masculinity is linked to war. We conducted a web-based survey to examine relationships between gender, attitudes toward war, and masculinities within a sample of Japanese adults of both sexes ( N = 366). Our results indicated that while men were more likely than women to accept war, the relationship between attitudes toward war and masculinities was inconclusive.

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The luminol chemiluminescence (CL) profile of an oil-in-water (O/W) emulsion during thermal oxidation (60°C) was assessed using the luminol-K[Fe(CN)] assay, in which the oxidation species produced by the autoxidation of an O/W emulsion generated CL emission. Increased CL intensity was observed for O/W emulsions prepared using either linseed or corn oil, which was increased by the addition of Fe to the O/W emulsion. The relationship between the CL profile and results obtained by conventional approaches, such as the peroxide value (PV) and thiobarbituric acid (TBA) methods, were compared.

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Propofol (PRO) is a hypnotic used to induce and maintain general anesthesia. A risk of drug-drug interactions exists in cases of clinical co-administration of PRO and midazolam (MDZ) or carbamazepine (CBZ). Therefore a sensitive and rapid assay is needed to monitor these drugs.

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Trolox, a water-soluble vitamin E analogue has been used as a positive control in Trolox equivalent antioxidant capacity and oxygen radical antioxidant capacity assays due to its high antioxidative effect. In this study, the ex vivo antioxidative effects of Trolox and its concentration in blood and brain microdialysates from rat after administration were evaluated by newly established semi-microflow injection analysis, chemiluminescence detection and HPLC-UV. In the administration test, the antioxidative effect of Trolox in blood and brain microdialysates after a single administration of 200 mg/kg of Trolox to rats could be monitored.

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Propofol (Pro) is an ultra-short-acting hypnotic agent used for general anesthesia that has no analgesic properties. Remifentanil (Rem) is an ultra-short-acting opioid administered concomitantly as an analgesic with Pro. To evaluate the pharmacokinetic interactions between Pro and Rem, we developed and validated a method combining high-performance liquid chromatography with tandem mass spectrometry for simultaneous determination of Pro and Rem.

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Sulfur-containing amino acids (SAAs), homocysteine (Hcy), methionine (Met) and cysteine (Cys) in blood are related to homocystinuria, an inborn error of metabolism. In this study, an assay method with HPLC-fluorescence detection to quantify the SAAs in a dried blood spot was established and applied to samples from newborn babies (n=200). Sample pretreatment involving reduction, derivatization with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole, and liquid-liquid extraction with ethyl acetate gave the separation of the derivatives with retention times within 12 min.

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New methods of preparing nanoparticles and in vivo studies of their behavior have been the subject of much study. However, there exist few studies on maintaining the nanoparticle size. In this work, we report on the interaction mechanism between raffinose and nanoparticles during freeze-drying.

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In vitro screening of a Fe(2+) -chelating effect using a Fenton's reaction-luminol chemiluminescence (CL) system is described. The luminescence between the reactive oxygen species generated by the Fenton's reaction and luminol was decreased on capturing Fe(2+) using a chelator. The proposed method can prevent the consumption of expensive seed compounds (drug discovery candidates) owing to the high sensitivity of CL detection.

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A chemiluminescence (CL) reaction of folic acid (FA) with ruthenium (II) and cerium (IV) was applied to quantify FA-related compounds such as FA, dihydrofolic acid, tetrahydrofolic acid, 5-methyltetrahydrofolic acid, 5-formyltetrahydrofolic acid and methotrexate (MTX). Among the FAs, 5-methyltetrahydrofolic acid provided the highest CL intensity. HPLC-CL detection of FA was applied to quantify FA in pharmaceutical preparations and supplements.

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Gelatin film sheets are often used to form the shell in soft capsules prepared using the rotary die method. Examination of the film sheet properties is extremely important when materials other than gelatin are used. We examined the relationship between the width and the tensile strength of the gelatin film sheet in order to establish the required indexes of the gelatin film sheets.

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A simple and selective HPLC-fluorescence (FL) method with FL probe, 4-[4-(4-dimethylaminophenyl)-5-phenyl-1H-imidazol-2-yl]benzoic acid methyl ester (DAPIM), for simultaneous determination of mercaptalbumin (HMA) and nonmercaptalbumin (HNA1) was developed. After HMA and HNA1 were separated on an ion-exchange column, they were on-line and post-column mixed with DAPIM. The DAPIM-albumin complex produces FL (λex 370nm and λem 510nm); however, DAPIM solution never gives the FL.

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The present study aims to investigate the possibility of interaction of donepezil (DP) and galantamine (GAL) as acetylcholinestrase inhibitors, on memantine (MT) hydrochloride in rat plasma by HPLC-fluorescence detection. The separation of MT was achieved within 12 min without interference of DP and GAL on the chromatogram. MT levels in rat plasma with a single administration of MT (2.

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Moderating effects of group type on the relationship between in-group social values and group identity were investigated. Previous research has indicated that values attached to the in-group, such as its status, privileges, and power, lead to increased group identity. However, these studies have not investigated the role of the type of in-groups on this effect.

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The binding of a lophine-based fluorescence probe, 4-[4-(4-dimethylaminophenyl)-5-phenyl-1H-imidazol-2-yl]benzoic acid methyl ester (DAPIM) with human serum albumin (HSA) was investigated by fluorescence spectroscopy under physiological conditions. While DAPIM shows extreme low fluorescence in aqueous solution, DAPIM binding with HSA emits strong fluorescence at 510nm. The binding constant and binding number determined by Scatchard plot was 3.

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3,4-Methylenedioxymethamphetamine (MDMA) and methamphetamine often cause serious adverse effects (e.g., rhabdomyolysis, and cardiac disease) following hyperthermia triggered by release of brain monoamines such as dopamine and serotonin.

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Isoamyl nitrite is used as a therapeutic reagent for cardiac angina and as an antidote for cyanide poisoning, but it is abused because of its euphoric properties. Therefore, a method to determine isoamyl nitrite is required in many fields, including pharmaceutical and forensic studies. In this study, a simple, rapid and sensitive method for the determination of isoamyl nitrite was developed using a flow injection analysis system equipped with a chemiluminescence detector and on-line photoreactor.

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An HPLC-fluorescence (FL) method for determination of sulfur-containing amino acids such as homocysteine (Hcy), methionine (Met) and cysteine (Cys) in human plasma was developed. The sulfur-containing amino acids were labeled with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F). Calibration curves in the range of 1-100 µm (Hcy and Met) and 5-500 µm (Cys) indicated good linearities (r ≥ 0.

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