Relative stereochemical determination of the C61-C83 fragment of symbiodinolide using a stereodivergent synthetic approach.

Structural determination is required in the use of marine natural products to create novel drugs and drug leads in medicinal chemistry. Symbiodinolide, which is a polyol marine natural product with a molecular weight of 2860, increases the intracellular Ca2+ concentration and exhibits inhibitory activity against cyclooxygenase-1. Seventy percent of the structure of symbiodinolide has been stereochemically clarified. Herein, we report the elucidation of the relative configuration of the C61-C83 fragment, which is among the remaining thirty percent, using a stereodivergent synthetic strategy. We first assigned the relative configuration of the C61-C74 fragment. Two candidate diastereomers of the C61-C74 fragment were synthesized, and their NMR data were compared with those of the natural product, revealing the relative stereochemistry of this component. We then narrowed down the candidate compounds for the C69-C83 fragment from 16 possible diastereomers by analyzing the NMR data of the natural product, and we thus selected eight candidate diastereomers. Stereodivergent synthesis of the candidates for this fragment and comparison of the NMR data of the natural product and the eight synthetic products resulted in the relative stereostructural clarification of the C69-C83 fragment. These individually determined relative stereochemistries of the C61-C74 and C69-C83 fragments were connected via the common C69-C73 tetrahydropyran moiety of the fragments. Finally, the relative configuration of the C61-C83 fragment of symbiodinolide was determined. The stereodivergent synthetic approach used in this study can be extended to the stereochemical determination of other fragments of symbiodinolide.

Meat the challenge: Segmentation and profiling of Japanese beef mince and its substitutes consumers.

Shifts in protein production methods are an emerging challenge toward realizing a sustainable society. This paper aims to examine preferences among Japanese consumers regarding attributes of beef mince and its substitutes, to develop consumer segments based on these preferences, and to explore the segment with higher acceptance of replacement from conventional products. This paper also aims to explain intersegment differences from consumer heterogeneity in human values, scientific literacy, and sociodemographic viewpoints for a deeper understanding of consumer behavior in each segment. The results of an online choice experiment involving 4421 consumers in Japan, using food labels on mince showed that Japanese-origin organic beef was associated with the highest utility among the five production methods mentioned. Five consumer segments were identified with latent class analysis: novelty accepters, generous customers, attribute-economy balancers, price-conscious, and conservatives, which vary in preference in choice behavior, sociodemographic, human values, and scientific literacy.

Real-Time Assessment of Causal Attribution Shift and Stay Between Two Successive Tests of Movement Aids.

The development of welfare assistive devices for frail elderly people has attracted significant attention for its effort to improve the quality of life and reduce the burden on caregivers. However, it is challenging to conduct multiple user tests because of the significant burden on the elderly; thus, we need efficient ways to extract insight through different approaches. In this study, we aim to elucidate real-time transitions in users' emotions and achievement motivation while using such a device. We synthesize an utterance analysis method based on attribution theory, in which all users' utterances are attributed to four categories (ability, effort, task difficulty, and luck) that follow the developed coding rules. Knowing the transitions in causal attribution allows us to extract salient experiences for users, especially by extracting shifts from them and analyzing why the shift occurred and what exactly was happening before and after the shift. If only salient user experiences can be referenced from the aggregate data, useful information can be extracted in a short time to improve system characteristics and the environment. We discussed the validity and reliability of the proposed method by conducting a user test of an electric-assisted four-wheeled cycle for frail elderly people in Kakegawa city in Shizuoka, Japan. We also succeeded in marking the points that need attention, which is about 33% of the total amount of utterance data (1626 utterances), and thus confirmed the potential of the proposed method. Future research should examine how the developed methodology can help designers improve assistive device development, as well as how it can contribute to other fields such as education and social assistance.

Necessity of two-dimensional visualization of validity in the nanomechanical mapping of atomic force microscopy for sulphur cross-linked rubber.

The importance of the two-dimensional (2D) visualization of validity for nanomechanical mapping in atomic force microscopy (AFM) for sulphur cross-linked rubber is emphasized for accurately interpreting the nanoscale physical properties on the surface of the soft material. The "R-factor," evaluated to be the difference between the experimental and theoretical force-deformation curves, was considered to be the reliability index of the AFM analysis for all data points on the sample surface. A small R-factor corresponds to high accuracy. The advantage of the R-factor mapping method is demonstrated using nanomechanical mapping data of the inhomogeneous isoprene rubber network by the Johnson-Kendall-Roberts and the Derjaguin, Muller, and Toporov contact mechanics models. The 2D R-factor mapping clearly and correctly supported the roles of sulphur cross-linking reagents to control the network morphology of vulcanizates. Additionally, the blanket effect, which is induced by the rubber layer on the hard part and influences experimental force-deformation curves, is firstly proposed in this study. Nanomechanical mapping with 2D reliability indexes is expected to contribute to an advance in AFM studies on soft matter such as rubber materials, leading to a more accurate understanding of the structural characteristics of the rubber networks. Thus, this validity confirmation method is necessary for developing rubber science and technology.

Late-stage divergent synthesis and antifouling activity of geraniol-butenolide hybrid molecules.

Hybrid molecules consisting of geraniol and butenolide were designed and synthesized by the late-stage divergent strategy. In the synthetic route, ring-closing metathesis was utilized for the construction of a butenolide moiety. A biological evaluation of the eight synthetic hybrid compounds revealed that these molecules exhibit antifouling activity against the cypris larvae of the barnacle Balanus (Amphibalanus) amphitrite with EC50 values of 0.30-1.31 µg mL-1. These results show that hybridization of the geraniol and butenolide structural motifs resulted in the enhancement of the antifouling activity.

[Limits of Cognition with Visual Parallax of Stereoscopic Images].

OBJECTIVES: Recent advances in three-dimensional (3D) display technology have contributed significantly to society, particularly in the increasing use of stereoscopic characters. For example, 3D text information is utilized in digital signage. However, research on 3D characters is limited and discussion on the safety and comfort of 3D technology is lacking. According to the 3D Consortium Safety Guidelines in Japan, a comfortable visual parallax with 3D images is less than ±1.0°. However, 3D text must be shown in front of its associated content in order for it to be displayed simultaneously with that content. METHODS: We carried out an experiments to verify the permissive limits of cognition in subjects regarding the parallax of 3D images. In the experiment, 94 subjects aged 18 to 81 viewed a 3D flat Maltess cross image having no depth and projected outward from a screen at a large parallax of 1.0° to 6.0°. RESULTS: Eighty-six percent of the subjects recognized the 3D flat image even when it protruded at a 2.0° parallax. These subjects viewed the image comfortably and without visual problems. CONCLUSIONS: This study concludes that people can cognitively recognize a 3D telop at a 2.0° parallax without feeling fatigued.