1,744 research outputs found
An Active and Soft Hydrogel Actuator to Stimulate Live Cell Clusters by Self-folding
The hydrogels are widely used in various applications, and their successful uses depend on controlling the mechanical properties. In this study, we present an advanced strategy to develop hydrogel actuator designed to stimulate live cell clusters by self-folding. The hydrogel actuator consisting of two layers with different expansion ratios were fabricated to have various curvatures in self-folding. The expansion ratio of the hydrogel tuned with the molecular weight and concentration of gel-forming polymers, and temperature-sensitive molecules in a controlled manner. As a result, the hydrogel actuator could stimulate live cell clusters by compression and tension repeatedly, in response to temperature. The cell clusters were compressed in the 0.7-fold decreases of the radius of curvature with 1.0 mm in room temperature, as compared to that of 1.4 mm in 37 degrees C. Interestingly, the vascular endothelial growth factor (VEGF) and insulin-like growth factor-binding protein-2 (IGFBP-2) in MCF-7 tumor cells exposed by mechanical stimulation was expressed more than in those without stimulation. Overall, this new strategy to prepare the active and soft hydrogel actuator would be actively used in tissue engineering, drug delivery, and micro-scale actuators
Organizing Pneumonia by Paragonimiasis and Coexistent Aspergilloma Manifested as a Pulmonary Irregular Nodule
Organizing pneumonia by paragonimiasis and coexistent aspergilloma as a pulmonary nodule is a rare case of lung disease. Its radiographic or CT feature has not been described before in the radiologic literature. We present organizing pneumonia by paragonimiasis and coexistent aspergilloma manifested as a pulmonary irregular nodule on CT
Association of factor XIII Val34Leu polymorphism and coronary artery disease: A meta-analysis
Background: Factor XIII plays an important role in the stabilization of the linkage between fibrins and in the pathophysiology of coronary artery disease (CAD). The association between factor XIII Val34Leu polymorphism and CAD risk remains controversial.
Methods: We conducted a meta-analysis of 36 studies involving 26,940 cases and 34,694 controls. Subgroup analyses were performed with division of data into disease (myocardial infarction [MI], CAD without MI), age, and sex.
Results: Factor XIII Val34Leu polymorphism was significantly associated with ove all CAD risk (odds ratio [OR] = 1.09, 95% confidence interval [CI] = 1.03–1.06, p = 0.004) and MI risk (OR = 1.15, 95% CI 1.07–1.25, p = 0.0003), but not with CAD without MI risk (OR = 1.00, 95% CI 0.87–1.15, p = 0.96). In the subgroup analysis by age and sex, there was no association between Val34Leu polymorphism and CAD.
Conclusions: This meta-analysis found that factor XIII Val34Leu polymorphism was associated with CAD risk, especially MI, but not with CAD without MI. In addition, age and sex did not affect the relationship between factor XIII Val34Leu polymorphism and CAD risk.
Multi-Agent Deep Reinforcement Learning for Efficient Passenger Delivery in Urban Air Mobility
It has been considered that urban air mobility (UAM), also known as
drone-taxi or electrical vertical takeoff and landing (eVTOL), will play a key
role in future transportation. By putting UAM into practical future
transportation, several benefits can be realized, i.e., (i) the total travel
time of passengers can be reduced compared to traditional transportation and
(ii) there is no environmental pollution and no special labor costs to operate
the system because electric batteries will be used in UAM system. However,
there are various dynamic and uncertain factors in the flight environment,
i.e., passenger sudden service requests, battery discharge, and collision among
UAMs. Therefore, this paper proposes a novel cooperative MADRL algorithm based
on centralized training and distributed execution (CTDE) concepts for reliable
and efficient passenger delivery in UAM networks. According to the performance
evaluation results, we confirm that the proposed algorithm outperforms other
existing algorithms in terms of the number of serviced passengers increase
(30%) and the waiting time per serviced passenger decrease (26%).Comment: 6 pages, 5 figure
Pharmacological effects of active saponins from Panax ginseng Meyer
Purpose: To investigate the pharmacological effects of the active saponins isolated from Panax ginseng Meyer (P. ginseng) via extraction, heat treatment, and enzyme conversion.
Methods: The effects of active saponins on rat blood were determined using a multichannel analyzer. The population doubling time (PDT) of mesenchymal stem cells (MSCs) and human-derived leukocyte cancer cells (A549) was determined by cell counting. b-galactosidase was measured in human toothderived stem cells (HTS) using a β-galactosidase ELISA kit.
Results: Intraperitoneal administration of active saponins resulted in 30.09 % increase in red blood cell count and 55.55 % decrease in blood triglyceride concentrations. The stimulatory effect of active saponins (10 ng/mL) on cellular differentiation was determined based on PDT of MSCs, which decreased by 33.82 % compared to control. A 22.29 % increase in PDT of A549 cells demonstrated the suppressive effects of active saponins on cancer cell growth. Active saponins (10 ng/mL) also decreased intracellular β-galactosidase concentration by 20.42 % in HTS cells.
Conclusion: Administration of active saponins to rats extends the lifespan, promotes differentiation in MSCs, suppresses A549 cell differentiation, and reduces TG and b-galactosidase associated with aging in HTS. Thus, active saponins have potentially beneficial effects in humans
A case of primary psoas abscess presenting as buttock abscess
Buttock abscess is a rare clinical manifestation from unusual extrapelvic extension of psoas abscess. A 48-year-old woman presented with painful swelling of the buttock with a sense of local heat. Magnetic resonance imaging revealed a large subfascial abscess over the glutei muscles and was traced into the intraabdominal cavity over the iliac wing to the psoas muscle. Both the psoas abscess and the buttock abscess were evacuated via separate approaches. Empirical antibiotic therapy was delivered for 3 weeks. After 6 months, no evidence of recurrence was found. Psoas abscess could be included in the differential diagnosis of buttock abscess
- …