RESUMEN

Respiratory masks are the primary and most effective means of protecting individuals from airborne hazards such as droplets and particulate matter during public engagements. However, conventional electrostatically charged melt-blown microfiber masks typically require thick and dense membranes to achieve high filtration efficiency, which in turn cause a significant pressure drop and reduce breathability. In this study, we have developed a multielectrospinning system to address this issue by manipulating the pore structure of nanofiber networks, including the use of uniaxially aligned nanofibers created via an electric-field-guided electrospinning apparatus. In contrast to the common randomly collected microfiber membranes, partially aligned dual-nanofiber membranes, which are fabricated via electrospinning of a random 150 nm nanofiber base layer and a uniaxially aligned 450 nm nanofiber spacer layer on a roll-to-roll collector, offer an efficient way to modulate nanofiber membrane pore structures. Notably, the dual-nanofiber configuration with submicron pore structure exhibits increased fiber density and decreased volume density, resulting in an enhanced filtration efficiency of over 97% and a 50% reduction in pressure drop. This leads to the highest quality factor of 0.0781. Moreover, the submicron pore structure within the nanofiber networks introduces an additional sieving filtration mechanism, ensuring superior filtration efficiency under highly humid conditions and even after washing with a 70% ethanol solution. The nanofiber mask provides a sustainable solution for safeguarding the human respiratory system, as it effectively filters and inactivates human coronaviruses while utilizing 130 times fewer polymeric materials than melt-blown filters. This reusability of our filters and their minimum usage of polymeric materials would significantly reduce plastic waste for a sustainable global society.

Asunto(s)

RESUMEN

This study aims to investigate human hair color perception through two empirical studies in the context of colored hair. The preliminary study was intended to establish a numerical representation of perceptually meaningful brightness levels. It identified that the brightness level was proportional to the power of 0.766 of L*. In the visual assessment, participants (N = 47) categorized 246 hair color samples into eight color hue groups aligned with the Munsell system. Hue judgment was conducted by visually comparing dyed hair tresses with natural black hair. Based on the L*, a*, and b* values of hair tresses and visual assessments thereof, we observed the ranges of hue categories for hair color alongside the brightness levels. Additionally, the differences between the Munsell hue names and the assessment results were compared. Predominantly influenced by the dark brown hair color, the neutral orientation was shifted to the first quadrant of the a*-b* plane. The study contributes to an understanding of human hair color perception and provides insights into color categorization and labeling, especially when the context is confined.

Asunto(s)

RESUMEN

This study investigated facial skin color differences before and after makeup. Toward this goal, a photo gauge, devised with a pair of color checkers as a reference, collected face images. In addition, color calibration and a deep-learning method extracted the color values of representative areas of facial skin. The photo gauge photographed 516 Chinese females before and after applying makeup. Then, the collected images were calibrated by referencing skin color patches, and the lower cheek regions' pixel colors were extracted using open-source computer vision libraries. Following the visible color spectrum of humans, the color values were computed in L*, a*, and b* of CIE1976L*a*b*. The results showed that the facial colors of the Chinese females changed to become brighter, less reddish, and less yellowish after applying the makeup, resulting in a paler skin tone. During the experiment, subjects were given five varieties of liquid foundation to choose one sample that best fits their skin. However, we failed to find any noticeable relationship between the individual's facial skin color characteristics and the liquid foundation selected. In addition, 55 subjects were identified according to their makeup use frequency and skill, but their color changes did not differ from the other subjects. This study provided quantitative evidence of makeup trends in the Shanghai region in China, and the method proposes a novel approach toward remote skin color research.

Asunto(s)

RESUMEN

We investigated physiological and subjective responses to morning light exposure of commercially available LED lighting with different correlated colour temperatures to predict how LED-based smart lighting employed in future learning environments will impact students. The classical markers of the circadian system (melatonin and cortisol), as well as the subjective perception of sleepiness, mood, and visual comfort, were compared. Fifteen university students underwent an hour of morning light exposure to both warm (3,500 K) and blue-enriched (6,500 K) white lights at recommended illuminance levels for classrooms and lecture halls (500 lux). The decline of melatonin levels was significantly greater after the exposure to blue-enriched white light. Exposure to blue-enriched white light significantly improved subjective perception of alertness, mood, and visual comfort. With regard to cortisol, we did not find a significant difference in the cortisol decrement between the two light conditions. Our findings suggest that the sensitivity of physiological and subjective responses to white LED light is blue-shifted. These findings, extending the already known effects of short-wavelength light on human physiology, reveal interesting practical implications. Blue-enriched LED light seems to be a simple yet effective potential countermeasure for morning drowsiness and dozing off in class, particularly in schools with insufficient daylight.

Asunto(s)

RESUMEN

This study aims to investigate the white perception of mobile display devices under dark-adapted and chromatic-adapted conditions. The white perception was modeled with error ellipses and bivariate Gaussian distributions. The dark-adapted white encompassed a rather large area centered around 7300 K, slightly above the Planckian locus. The chromatic-adapted whites were highly dependent on the ambient illuminant, and were not parallel to the Planckian locus. Combined, the white region encompassing 6179 to 7479 K in correlated color temperature and -0.0038 to 0.0144 in Duv was suggested. The results of this study are expected to be the basis for enhanced white appearance on mobile display devices.

RESUMEN

This study aims to investigate the effects of lighting color temperatures on elementary students' performance, and thereby propose a dynamic lighting system for a smart learning environment. Three empirical studies were conducted: First, physiological responses were measured as a potential mediator of performance. Second, cognitive and behavioral responses were observed during academic and recess activities. Lastly, the experiment was carried out in a real-life setting with prolonged exposure. With a comprehensive analysis of the three studies, three lighting presets-3500 K, 5000 K, and 6500 K-are suggested for easy, standard, and intensive activity, respectively. The study is expected to act as a good stepping stone for developing dynamic lighting systems to support students' performance in learning environments.

Asunto(s)

RESUMEN

This study aims to derive context-based lighting setup presets in residential space by exploring the multilateral relationships among household activities, affects, and lighting setups. Three procedures were involved: First, sixty affective words were evaluated through which seven affect factors were extracted to facilitate the evaluation of colored illumination in the subsequent experiment. Second, in the user study, seven affect factors and thirty household activities were used to evaluate 147 lighting setups extracted from combinations of twelve hues, six illuminance levels, and three purity levels. As a result, twenty lighting setup presets were derived that were not only activity-based, but affect-based as well. Lastly, the twenty presets were prototyped as a set of testbed to further explore potentials and limitations. This study demonstrates that intuitive, context-based presets can help users explore the effects of colored illumination in creating a diverse range of user experiences.

Asunto(s)

RESUMEN

Renal artery stenosis (RAS) is commonly presented with hypertension and chronic kidney disease. We report a rare case of RAS occurring in a 78-year-old man who presented with nephrotic-range proteinuria. Renal biopsy on the left side was performed, and results showed mesangiopathic glomerulonephritis, which was not compatible with the cause of nephrotic-range proteinuria. Proteinuria was decreased by angiotensin receptor blocker, but azotemia was aggravated. Therefore, angiotensin receptor blocker was discontinued inevitably and thorough evaluation for the possibility of RAS was performed. Computed tomography angiography revealed significant RAS on the left side and a renal artery stent was inserted. After stenting, aortic dissection developed and progressed despite tight control of blood pressure. After inserting another stent graft through the true lumen of the left renal artery, the patient's renal function and proteinuria improved markedly.

Asunto(s)

RESUMEN

We herein describe a 70-year-old woman who presented with respiratory failure due to extensive lung adenocarcinoma. Despite advanced disease, care in the intensive care unit with ventilator support was performed because she was a newly diagnosed patient and was considered to have the potential to recover after cancer treatment. Because prompt control of the cancer was needed to treat the respiratory failure, empirical treatment with an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was initiated before confirmation of EGFR-mutant adenocarcinoma, and the patient was successfully treated. Later, EGFR-mutant adenocarcinoma was confirmed.

Asunto(s)

RESUMEN

We herein describe a 70-year-old woman who presented with respiratory failure due to extensive lung adenocarcinoma. Despite advanced disease, care in the intensive care unit with ventilator support was performed because she was a newly diagnosed patient and was considered to have the potential to recover after cancer treatment. Because prompt control of the cancer was needed to treat the respiratory failure, empirical treatment with an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor was initiated before confirmation of EGFR-mutant adenocarcinoma, and the patient was successfully treated. Later, EGFR-mutant adenocarcinoma was confirmed.

Asunto(s)

RESUMEN

The study investigates the optimal display luminance for viewing smartphones in conditions of low illuminance. This proposes a model of adaptive display in that display luminance changes gradually with the passage of watching time. It starts at a fairly low display luminance of 10 cd/m2, and after 10 seconds, the luminance increases slowly until it reaches 40 cd/m2 for 20 seconds and maintains the luminance. For the development of the model, an experiment was conducted to identify the optimal luminance for initial viewing and that for continuous viewing, as well as the change speed of display luminance. In order to validate the model, users' subjective judgments and activation of alpha rhythm were observed, and the result confirmed the superiority of the adaptive display luminance compared to the current display luminance in terms of physiological comfort and psychological satisfaction. It is expected that this study contributes to the pleasing use of displays at night under low illuminance by applying to diverse types of display devices.

RESUMEN

Although cystic fibrosis (CF) is one of the most common hereditary disorders among Caucasians, it is very rare in the Korean population. Patients with CF are at particularly high risk for developing lung disease caused by nontuberculous mycobacteria such as the Mycobacterium avium-intracellulare complex or Mycobacterium abscessus. Here, we report a successfully treated case of M. abscessus lung disease in a Korean patient with CF.

Asunto(s)

RESUMEN

Metastases to skeletal muscle and paraneoplastic syndromes involving beta-human chorionic gonadotropin (HCG) production are an extremely rare manifestation of head and neck squamous cell carcinoma. We report a patient with a beta-HCG-secreting squamous cell carcinoma of the tongue with diffuse metastases involving skeletal muscle. A 47 year old female, who was being treated heavily with palliative chemotherapy for metastatic tongue cancer, was admitted with a palpable thigh mass and pain. A magnetic resonance image showed an intramuscular metastasis in the thigh. Ultrasound-guided biopsy of the thigh mass confirmed metastatic squamous cell carcinoma. She was scheduled for enrollment into a clinical trial; however, a positive serum beta-HCG test was noticed. There was no evidence of pregnancy or a trophoblastic or non-trophoblastic tumor secreting beta-HCG. Finally, she was revealed to have a paraneoplastic syndrome with diffuse metastases and was ultimately referred for palliative care. We review the literature of previously reported cases of an increase of beta-HCG in patients with head and neck cancer.

Asunto(s)

RESUMEN

This is a report of the first South Korean case of a lung disease caused by Mycobacterium simiae. The patient was a previously healthy 52-year-old female. All serial isolates were identified as M. simiae by multi-locus sequencing analysis, based on hsp65, rpoB, 16S-23S rRNA internal transcribed spacer, and 16S rRNA fragments. A chest radiography revealed deterioration, and the follow-up sputum cultures were persistently positive, despite combination antibiotic treatment, including azithromycin, ethambutol, and rifampin. To the best of our knowledge, this is the first confirmed case of a lung disease caused by M. simiae in South Korea.

Asunto(s)

RESUMEN

Primary ciliary dyskinesia (PCD) is characterized by the congenital impairment of mucociliary clearance. When accompanied by situs inversus, chronic sinusitis and bronchiectasis, PCD is known as Kartagener syndrome. The main consequence of impaired ciliary function is a reduced mucus clearance from the lungs, and susceptibility to chronic respiratory infections due to opportunistic pathogens, including nontuberculous mycobacteria (NTM). There has been no report of NTM lung disease combined with Kartagener syndrome in Korea. Here, we report an adult patient with Kartagener syndrome complicated with Mycobacterium abscessus lung disease. A 37-year-old female presented to our hospital with chronic cough and sputum. She was ultimately diagnosed with M. abscessus lung disease and Kartagener syndrome. M. abscessus was repeatedly isolated from sputum specimens collected from the patient, despite prolonged antibiotic treatment. The patient's condition improved and negative sputum culture conversion was achieved after sequential bilateral pulmonary resection.

Asunto(s)