Porous composite with negative thermal expansion obtained by photopolymer additive manufacturing

Additive manufacturing (AM) could be a novel method of fabricating composite and porous materials having various effective performances based on mechanisms of their internal geometries. Materials fabricated by AM could rapidly be used in industrial application since they could easily be embedded in the target part employing the same AM process used for the bulk material. Furthermore, multi-material AM has greater potential than usual single-material AM in producing materials with effective properties. Negative thermal expansion is a representative effective material property realized by designing a composite made of two materials with different coefficients of thermal expansion. In this study, we developed a porous composite having planar negative thermal expansion by employing multi-material photopolymer AM. After measurement of the physical properties of bulk photopolymers, the internal geometry was designed by topology optimization, which is the most effective structural optimization in terms of both minimizing thermal stress and maximizing stiffness. The designed structure was converted to a three-dimensional STL model, which is a native digital format of AM, and assembled as a test piece. The thermal expansions of the specimens were measured using a laser scanning dilatometer. The test pieces clearly showed negative thermal expansion around room temperature.Comment: 11 pages, 4 figure

Postnatal development of inhibitory synaptic transmission to superior salivatory neurons in rats

The primary parasympathetic center of the submandibular and sublingual salivary glands is the superior salivatory (SS) nucleus, and its neurons receive excitatory (glutamatergic) and inhibitory (GABAergic and glycinergic) synaptic transmissions in rats. In the present study, we focused on the postnatal development of inhibitory transmission to SS neurons. Gramicidin-perforated whole-cell patch-clamp recordings were performed in rat brainstem slices on postnatal day 2 (P2)-P14. Developmental changes in the intracellular Cl- concentration ([Cl-]in) were examined based on the reversal potentials of total inhibitory postsynaptic currents (GABAergic plus glycinergic), which were evoked by electrical stimulation near the recording neuron. The [Cl-]in in the P8-P14 groupwas significantly lower than in the P2-P7 group. The effect of GABA application at the resting potentials changed from depolarization to hyperpolarization around P8, suggesting that SS neurons acquired mature inhibitory systems around P8. The period at which GABA responses change from excitatory to inhibitory in SS neurons was discussed compared with those of the forebrain, brainstem, and spinal neurons

Endoscopic findings of gastric neoplasms in familial adenomatous polyposis are associated with the phenotypic variations and grades of dysplasia

Patients with familial adenomatous polyposis (FAP) are at increased risk of developing gastric neoplasms. However, endoscopic findings have not been sufficiently investigated. We investigated the phenotypic expression of gastric adenoma (low-grade dysplasia) and gastric cancer (high-grade dysplasia or carcinoma) in patients with FAP and clarified their relationships to endoscopic findings. Of 29 patients with FAP who underwent esophagogastroduodenoscopy between 2005 and 2020, 11 (38%) had histologically confirmed gastric neoplasms, including 23 lesions of gastric adenoma and 9 lesions of gastric cancer. The gastric neoplasms were classified into 3 phenotypes (gastric, mixed, or intestinal type) according to the immunostaining results and evaluated for location (U or M region: upper or middle third of the stomach or L region: lower third of the stomach), color (same as the background mucosa, whitish, or reddish), macroscopic type (elevated, flat, or depressed), background mucosal atrophy (present or absent), fundic gland polyps in the surrounding mucosa (present or absent), and morphologic changes in tumor size. Elevated whitish gastric adenomas were further subdivided by macroscopic type (flat elevated, protruded, or elevated with a central depression) and color (milky- or pinkish-white). The gastric adenomas included gastric (11/23, 48%), mixed (4/23, 17%), and intestinal (8/23, 35%) phenotypes. In contrast, no lesions of gastric cancers showed a gastric phenotype (0/9, 0%), while 5 (56%) and 4 (44%) lesions were intestinal and mixed phenotypes, respectively. Gastric cancers were significantly more likely than gastric adenomas to present as reddish depressed lesions with gastric atrophy. All gastric-type adenomas occurred in non-atrophic mucosa, in mucosa with fundic gland polyps in the periphery, in the U or M region, and as flat elevated or protruded lesions with a milky-white color. Half of the lesions increased in size. Meanwhile, the typical endoscopic features of intestinal-type adenomas included occurrence in the L region and elevated pinkish-white lesions with central depression. None of the intestinal-type adenomas increased in size during the observation period. We believe that these endoscopic features will be useful for the prompt diagnosis and appropriate management of gastric neoplasms in patients with FAP

Clinical effects of swimming training in a hot spring pool on bronchial asthma

Five severe bronchial asthma patients with glucocorticoid therapy have had free swimming training in the hot spring pool at Misasa Medical Branch. The clinical effect of the swimming training was evaluated after 3 months' training. 1. A slight increase in pulse rate and blood pressure was observed immediately after 30 minutes, swimming, although no significant increase in the two parameters was shown 30 min. after the training. 2. No significant fall in ventilatory function tests such as % FVC, FEV(1.0)%, V(50) and V(25) was demonstrated following the swimming training in a hot spring pool. The results suggest that the free swimming training in a hot spring pool does not induce bronchoconstriction. 3. Clinical efficacy of the swimming training on bronchial asthma was evaluated according to a treatment score, an attack score and an asthmatic score. These scores were decreased during the swimming training. The results obtained in this study showed that free swimming training in a hot spring pool is one of the most suitable therapies for severe bronchial asthma patients