A portable liquid chromatography system based on a separation/detection chip module consisting of a replaceable ultraviolet-visible absorbance or contactless conductivity detection unit.

Recently, there has been a growing demand for miniaturized analytical instruments, including portable HPLC systems, that can enable rapid analysis in the field. This study aimed to develop chip-based separation/detection modules with replaceable detection units for constructing compact HPLC systems to minimize the dead volume. This module provides a tubing-free connection between the column and the detection unit. This study also built detection units for conductivity detection and ultraviolet-visible (UV-Vis) detection to cover a wide variety of inorganic and organic compounds. Furthermore, UV- and Vis-light-emitting diodes were employed for the absorbance detection unit. In addition, portable all-in-one HPLC systems and a handy HPLC system were constructed for ion chromatography and reversed-phase chromatography, demonstrating the successful separation and detection of inorganic ions and several organic compounds.

Interpersonal predictors of loneliness in Japanese children: variable- and person-centered approaches.

BACKGROUND: Loneliness in children has been a major topic of interest in both clinical and developmental psychology. Further studies to investigate predictors of loneliness are needed for educational practices. METHODS: A total of 1088 late elementary school-aged children (48.81% boys, Mage = 10.35) participated in a 1-year longitudinal survey. We used hierarchical linear modeling and mover-stayer latent transition analysis. DISCUSSION: Findings from the variable- and person- centered approaches suggested that less positive peer relations, higher victimization, and higher relational aggression are predictors of higher future loneliness. Meanwhile, both approaches did not reach an agreement concerning predictors to reduce loneliness. This result highlighted a utility of a combined approach and sounded an alarm for overreliance on the variable-centered approach dominating child research. CONCLUSION: To protect young children from loneliness, it will be more beneficial to prevent the development of loneliness rather than to apply interventions to reduce loneliness once established. Preventive practices need to be implemented to protect children from loneliness.

Supercritical fluid chromatography with post-column addition of supporting electrolyte solution for electrochemical determination of tocopherol and tocotrienol isomers.

A supercritical fluid chromatography with electrochemical detection system was developed for the simultaneous determination of tocopherol and tocotrienol isomers. The supercritical fluid chromatography with electrochemical detection system was connected with an additional pump to create a flow path to add a supporting electrolyte solution. The supporting electrolyte solution was mixed with a mobile phase in a post-column fashion, enabling the independent control of the separation and detection. After optimization of the measurement conditions, vitamin E isomers and an internal standard substance (2,2,5,7,8-pentamethyl-6-hydroxychroman) were separated within 30 min using a mixture of supercritical carbon dioxide and methanol (99:1, v/v) as a mobile phase and a cyanopropyl column (4.6 mm inner diameter × 250 mm length, 5 µm). For the electrochemical detection, methanol containing 1.0 mol/L ammonium acetate was used as a supporting electrolyte solution, and the applied potential was set at +0.8 V. This analytical method showed good linearity (5-100 µg/mL) and repeatability (less than 2.5% relative standard deviation, n = 6) and was applicable to the determination of tocopherol and tocotrienol isomers in nutrition supplements.

Prevention of Acute Upper Respiratory Infections by Consumption of Catechins in Healthcare Workers: A Randomized, Placebo-Controlled Trial.

Catechins, phytochemicals contained mainly in green tea, exhibit antiviral activity against various acute infectious diseases experimentally. Clinical evidence supporting these effects, however, is not conclusive. We performed a placebo-controlled, single-blind, randomized control trial to evaluate the clinical effectiveness of consumption of catechins-containing beverage for preventing acute upper respiratory tract infections (URTIs). Two hundred and seventy healthcare workers were randomly allocated to high-catechin (three daily doses of 57 mg catechins and 100 mg xanthan gum), low-catechin (one daily dose of 57 mg catechins and 100 mg xanthan gum), or placebo (0 mg catechins and 100 mg xanthan gum) group. Subjects consumed a beverage with or without catechins for 12 weeks from December 2017 through February 2018. The primary endpoint was incidence of URTIs compared among groups using a time-to-event analysis. A total of 255 subjects were analyzed (placebo group n = 86, low-catechin group n = 85, high catechin group n = 84). The URTI incidence rate was 26.7% in the placebo group, 28.2% in the low-catechin group, and 13.1% in the high-catechin group (log rank test, p = 0.042). The hazard ratio (95% confidence interval (CI)) with reference to the placebo group was 1.09 (0.61-1.92) in the low-catechin group and 0.46 (0.23-0.95) in the high-catechin group. These findings suggest that catechins combined with xanthan gum protect against URTIs.

[The development of the Five-item Loneliness Scale for Children].

The purpose of the present study was to develop a simplified scale to assess loneliness in children. Participants were 646 elementary school students (335 boys and 311 girls) from 4th to 6th grade and 24 homeroom teachers who identified lonely children within the participants of their classes. The'student participants completed the Five-item Loneliness Scale for Children (Five-LSC) and other scales measuring social skills, social competence, and withdrawal to confirm the validity of the Five-LSC. The results showed that the Five-LSC was both reliable and valid. In addition, there were no grade or sex differences in loneliness. Future research using the Five-LSC was discussed.

[The relationship between autonomous motivation and academic adjustment in junior high school students].

This study investigated the relationship between autonomous motivation and academic adjustment based on the perspective of self-determination theory. It also examined motivational profiles to reveal individual differences and the characteristic of these profiles for groups with varying levels of autonomous and controlled regulation (autonomous, controlled, high motivation, and low motivation). Data were collected from 442 junior high school students for academic motivation, academic performance, academic competence, meta-cognitive strategy, academic anxiety, apathy, and stress experience. Correlation analyses generally supported the basic hypothesis of self-determination theory that a more autonomous regulation style was strongly related to academic adjustment. The results also showed that persons with a high autonomous regulation and a low controlled regulation style were the most adaptive.

[Changes in academic motivation among elementary and junior high school students].

This study examined changes in academic motivation among elementary and junior high school students. Based on self-determination theory (Ryan & Deci, 2000a), we focused on changes in autonomous and controlled motivation. In Study 1, we examined inter-individual changes in academic motivation among 5th to 9th grade students (N = 1 572) through a cross-sectional study. In Study 2, we examined intra-individual changes in academic motivation among students (N = 128) who were in transition from elementary to junior high school through a longitudinal study. All participants completed the Academic Motivation Scale (Nishimura, Kawamura, & Sakurai, 2011) that measured autonomous and controlled motivation. The results revealed that autonomous motivation decreased in the students from elementary to junior high school, while controlled motivation increased during the same period. This is a unique finding because a prior study conducted in a Western culture suggested that both motivations decrease gradually in school.

Resonant-type Smooth Impact Drive Mechanism (SIDM) actuator using a bolt-clamped Langevin transducer.

The Smooth Impact Drive Mechanism (SIDM) is a linear piezoelectric actuator that has seen practically applied to camera lens modules. Although previous SIDM actuators are easily miniaturized and enable accurate positioning, these actuators cannot actuate at high speed and cannot provide powerful driving because they are driven at an off-resonant frequency using a soft-type PZT. In the present study, we propose a resonant-type SIDM using a bolt-clamped Langevin transducer (BLT) with a hard-type PZT. The resonant-type SIDM overcomes the above-mentioned problems and high-power operation becomes possible with a very simple structure. As a result, we confirmed the operation of resonant-type SIDM by designing a bolt-clamped Langevin transducer. The properties of no-load maximum speed was 0.28m/s at driving voltages of 80V(p-p) for 44.9kHz and 48V(p-p) for 22.45kHz with a pre-load of 3.1N.

Formation of metal-assisted stable double helices in dimers of cyclic bis-tetrapyrroles that exhibit spring-like motion.

Bidipyrrin-bridged macrocycles, prepared from Ni(II)-bridged dipyrrin-based nanorings by intramolecular oxidative biaryl coupling reactions, yielded [2+4]-type Zn(II)-assisted stable twisted-ring dimers comprising two double helices. These [2+4]-type metal complexes can be optically resolved by chiral HPLC and exhibit tunable electronic and optical properties as a result of spring-like motions. The double helices behave as glue to connect two macrocycles and as the screws of hinges to form thermally responsive synchronized spring systems.