Study on Bearing Strength and Failure Modes of Single Bolted Joint Carbon/Epoxy Composite Materials.

The growth of the Urban Air Mobility (UAM) industry emphasizes the need for considerable study into assembly procedures and dependability to guarantee its effective integration into air transport networks. In this context, this study seeks to evaluate the mechanical characteristics of bolted joint Carbon Fiber Reinforced Plastic (CFRP), with a particular emphasis on bearing strength. By altering the w/D (specimen width to hole diameter) and e/D (distance between hole center and specimen end to hole diameter) ratios, the study investigates how edge and end distances affect material performance. The study discovered a shift from tension to bearing failure at w/D ratios of 4.0, with maximum bearing strength decreases of 90.50% and 69.96% compared to full bearing failure. Similarly, for e/D ratios of 1.5, 2.0, and 3.0, transitioning from shear to bearing failure at 2.0 resulted in maximum bearing strength losses of 94.90% and 75.96%, respectively. Maintaining a w/D ratio of at least 6.0 and an e/D ratio of at least 3.0 is critical for maintaining maximum performance and stability in CFRP structure design.

Effect of Ambient Plasma Treatments on Thermal Conductivity and Fracture Toughness of Boron Nitride Nanosheets/Epoxy Nanocomposites.

With the rapid growth in the miniaturization and integration of modern electronics, the dissipation of heat that would otherwise degrade the device efficiency and lifetime is a continuing challenge. In this respect, boron nitride nanosheets (BNNS) are of significant attraction as fillers for high thermal conductivity nanocomposites due to their high thermal stability, electrical insulation, and relatively high coefficient of thermal conductivity. Herein, the ambient plasma treatment of BNNS (PBNNS) for various treatment times is described for use as a reinforcement in epoxy nanocomposites. The PBNNS-loaded epoxy nanocomposites are successfully manufactured in order to investigate the thermal conductivity and fracture toughness. The results indicate that the PBNNS/epoxy nanocomposites subjected to 7 min plasma treatment exhibit the highest thermal conductivity and fracture toughness, with enhancements of 44 and 110%, respectively, compared to the neat nanocomposites. With these enhancements, the increases in surface free energy and wettability of the PBNNS/epoxy nanocomposites are shown to be attributable to the enhanced interfacial adhesion between the filler and matrix. It is demonstrated that the ambient plasma treatments enable the development of highly dispersed conductive networks in the PBNNS epoxy system.

Investigation of transient eye closure evoked with bright light in the patients with intermittent exotropia.

BACKGROUND: This study aimed to present a simple method for evaluating transient eye closure (TEC) evoked by bright light and find the agreement between TEC and photosensitivity. We also assessed the associated factors with TEC in the patients with intermittent exotropia (IXT). METHODS: In this retrospective study, IXT patients were exposed to different brightness: darkness, low-intensity white light, and high-intensity white light using a near-infrared camera vision monitor system (Mon CV3, Metrovision, France). TEC was considered to be present if the subject closed his or her eyes immediately, and for more than half of the scotopic lid fissure distance in response to the high-intensity or low-intensity photopic stimulus of light, compared with lid fissure distance in the scotopic phase. We assessed the presence of photosensitivity using a questionnaire and evaluated the agreement between TEC and photosensitivity. We also investigated the sensory fusion, motor fusion, and pupil dynamic components for the existence of TEC in IXT patients. RESULTS: Sixty-one patients with IXT were included. With the new method to evaluate TEC under different light intensities, 27 (44.3%) of the 61 IXT patients showed TEC, and 34 (55.7%) did not demonstrate TEC. TEC under high-intensity white light had a strong correlation with self-reporting photosensitivity (r = 0.77). The smaller angle of deviation at near was associated with the presence of TEC, with statistical significance (p = 0.04). Normal sensory status at a distance was significantly associated with TEC (p <  0.01). Multivariate analysis using multiple logistic regression analysis showed that normal sensory status was significantly associated with TEC (p = 0.02). CONCLUSIONS: The test using a near-infrared camera vision monitor system was a simple and objective tool in identifying TEC evoked by bright light. The presence of TEC strongly correlated with self-reporting photosensitivity in patients with IXT. However, TEC may be an independent phenomenon with motor alignment, stereopsis, and pupil reflex pathway in patients with IXT.

Development of New Solitary Retinoblastoma Tumors during and after Chemotherapy.

PURPOSE: To review the occurrence of new solitary tumors during and after intravenous chemotherapy against retinoblastoma. METHODS: From 115 eyes of 78 patients with a diagnosis of intraocular retinoblastoma who underwent intravenous chemotherapy and focal treatment without prior treatment, patient demographics, age at diagnosis, laterality, classification (Reese-Ellsworth and International Classification of Retinoblastoma), and treatment options were recorded. In addition, the occurrence of small tumors during and after chemotherapy was documented with a detailed review of medical records and fundus photographs. RESULTS: Of a total of 115 eyes of 78 consecutive patients, new solitary tumors were observed in 50 eyes (50 / 115, 43%) of 40 patients (40 / 78, 51%). Multinominal logistic regression analyses showed that age at diagnosis (before 1 year) and vitreal seeding at diagnosis were linked to the development of isolated and miliary tumors, respectively. Kaplan-Meier analyses demonstrated that all small tumors developed with 20 months from the start of chemotherapy. Twenty-eight eyes (28 / 34, 82%) were salvaged with additional focal treatment in 34 eyes with isolated tumors. CONCLUSIONS: Small tumors were observed during and after chemotherapy against retinoblastoma in patients who underwent intravenous chemotherapy and focal treatment. It is necessary to promptly identify and address small tumors for the preservation of eyeball and vision.

[Endoscopic Diagnosis of Aortoesophageal Fistula Not Presenting Hematemesis].

Aortoesophageal fistula (AEF) is an extremely rare but lethal cause of massive gastrointestinal hemorrhage. Characteristic symptoms are mid-thoracic pain, sentinel minor hemorrhage, and massive hemorrhage after a symptom-free interval. Prompt diagnosis and immediate treatments are necessary to reduce mortality. However, AEF is difficult to diagnose because it is uncommon and often leads to death with massive bleeding before proper evaluation. We report a case of endoscopic diagnosis of AEF that did not present with hematemesis; it was treated with thoracic endovascular aortic repair (TEVAR) and surgery. A 71-year-old female presented to the emergency department with epigastric discomfort. Endoscopy demonstrated a submucosal tumor-like protrusion and pulsating mass with blood clots. Contrast-enhanced chest CT confirmed AEF due to descending thoracic aortic aneurysm. The patient immediately underwent TEVAR to prevent massive bleeding and subsequently underwent surgery. Endoscopists should consider AEF if they see a submucosal tumor-like mass with a central ulcerative lesion or a pulsating protrusion covered with blood clots in mid-esophagus during an endoscopy.

Nonconvulsive status epilepticus disguising as hepatic encephalopathy.

Nonconvulsive status epilepticus has become an important issue in modern neurology and epileptology. This is based on difficulty in definitively elucidating the condition and its various clinical phenomena and on our inadequate insight into the intrinsic pathophysiological processes. Despite nonconvulsive status epilepticus being a situation that requires immediate treatment, this disorder may not be appreciated as the cause of mental status impairment. Although the pathophysiology of nonconvulsive status epilepticus remains unknown, this disorder is thought to lead to neuronal damage, so its identification and treatment are important. Nonconvulsive status epilepticus should be considered in the differential diagnosis of patients with liver cirrhosis presenting an altered mental status. We report a case of a 52-year-old male with liver cirrhosis presenting an altered mental status. He was initially diagnosed with hepatic encephalopathy but ultimately diagnosed with nonconvulsive status epilepticus by electroencephalogram.

[A Case of Small Bowel Diffuse Large B-cell Lymphoma Mimicking Crohn's Disease].

A 66-year-old male with dyspepsia and weight loss was referred to our hospital for evaluation. On laboratory examination, anti-saccharomyces cerevisiae (ASCA)-IgA was positive and iron deficiency anemia was present. PET/CT and abdominal CT scan images showed multiple small bowel segmental wall thickening and inflammation. Capsule endoscopy images showed multiple small bowel ulcerative lesions with exudates. Based on laboratory test results and imaging studies, the patient was diagnosed with Crohn's disease and treated with prednisolone and 5-aminosalicylic acid (5-ASA). However, the patient underwent second operation due to small bowel perforation within 2 month after initiation of treatment. Pathology report of the resected specimen was compatible to primary small bowel diffuse large B cell lymphoma and pertinent treatment was given to the patient after recovery. Herein, we describe a case of primary small bowel diffuse large B cell lymphoma that was mistaken for Crohn's disease.

Optical induction of muscle contraction at the tissue scale through intrinsic cellular amplifiers.

The smooth muscle cell is the principal component responsible for involuntary control of visceral organs, including vascular tonicity, secretion, and sphincter regulation. It is known that the neurotransmitters released from nerve endings increase the intracellular Ca(2+) level in smooth muscle cells followed by muscle contraction. We herein report that femtosecond laser pulses focused on the diffraction-limited volume can induce intracellular Ca(2+) increases in the irradiated smooth muscle cell without neurotransmitters, and locally increased intracellular Ca(2+) levels are amplified by calcium-induced calcium-releasing mechanisms through the ryanodine receptor, a Ca(2+) channel of the endoplasmic reticulum. The laser-induced Ca(2+) increases propagate to adjacent cells through gap junctions. Thus, ultrashort-pulsed lasers can induce smooth muscle contraction by controlling Ca(2+), even with optical stimulation of the diffraction-limited volume. This optical method, which leads to reversible and reproducible muscle contraction, can be used in research into muscle dynamics, neuromuscular disease treatment, and nanorobot control.