426 research outputs found
Microspinning: Local Surface Mixing via Rotation of Magnetic Microparticles for Efficient Small-Volume Bioassays
The need for high-throughput screening has led to the miniaturization of the reaction volume of the chamber in bioassays. As the reactor gets smaller, surface tension dominates the gravitational or inertial force, and mixing efficiency decreases in small-scale reactions. Because passive mixing by simple diffusion in tens of microliter-scale volumes takes a long time, active mixing is needed. Here, we report an efficient micromixing method using magnetically rotating microparticles with patterned magnetization induced by magnetic nanoparticle chains. Because the microparticles have magnetization patterning due to fabrication with magnetic nanoparticle chains, the microparticles can rotate along the external rotating magnetic field, causing micromixing. We validated the reaction efficiency by comparing this micromixing method with other mixing methods such as simple diffusion and the use of a rocking shaker at various working volumes. This method has the potential to be widely utilized in suspension assay technology as an efficient mixing strategy
Surface Sr segregation behaviors in a model thin film perovskite cathode for solid oxide fuel cells
Surface cation segregation, strontium (Sr) in particular, has been considered as one of crucial barriers to achieving a fast surface oxygen exchange rate of perovskite oxide electrodes for solid oxide fuel cells (SOFCs). However, the major driving force for the segregation phenomenon still remains unknown, and thus it is also unknown how to maximize the cathode performance.
In this work, we fabricated epitaxial thin films of SrTi1-xFexO3-δ (STF) via pulsed laser deposition (PLD) and quantitatively characterized their microstructures, surface chemical compositions and oxygen exchange rates by a range of analysis tools, in this case HR-TEM, HR-XRD, angle resolved X-ray photoelectron spectroscopy (AR-XPS) and electrical conductivity relaxation (ECR). The use of well-defined epitaxial thin films not only guarantees high precision, reproducibility and reliability of the surface properties, but also enables us to control the degree of misfit strain by varying the choice of the substrate and the target composition. This, in combination with density functional theory (DTF) simulation, enabled to reveal a close relationship between the degree of surface Sr segregation and the misfit strain and thereby to identify the governing factors for the Sr segregation phenomenon
How Many Sentinel Lymph Nodes Are Enough for Accurate Axillary Staging in T1-2 Breast Cancer?
Purpose: During a sentinel lymph node biopsy (SLNB) for breast cancer, the appropriate number of sentinel lymph nodes (SLNs) to be removed for accurate axillary staging is still controversial. We hypothesized that there might be an optimal threshold number of SLNs. We investigated how many SLNs should be removed to achieve an acceptable accuracy and ensure minimal morbidity. Methods: We reviewed data of 328 patients with invasive breast cancer who underwent SLNB followed by complete level I and II axillary dissection between January 2004 and December 2005. The false negative rate (FNR) and accuracy of SLNB according to the number of removed SLNs were evaluated. Results: The mean number of SLNs removed was 3.0 (range, 1-14), and that of total retrieved axillary lymph nodes was 17.5 (range, 10-40). In total, 111 (33.8%) patients had positive nodes on the permanent pathological report. Among them, 12 patients had negative SLNs
First Record of a Snailfish, Careproctus notosaikaiensis (Scorpaeniformes: Liparidae) from Korea
A single specimen (134.3 mm standard length) of a snailfish, Careproctus notosaikaiensis was collected from a fish trap in Goseong-gun, Gangwon-do, East Sea, Korea. It is characterized by having the teeth strongly trilobed; dorsal fin rays 52; anal fin rays 47; pectoral fin rays 35; caudal fin rays 10; vertebrae 58; ribs 2 pairs; cephalic pores, 2-6-7-2; gill slit extending to the fifth pectoral fin ray; chin pores paired and equal in size; dorsal and anal fins with distinct reddish margins. We describe this species as the first record to Korea, and proposed the new Korean name, “Dong-hae-bun-hong-ggom-chi” for this species
Comprehensive Analysis of Individual Anatomical Structures for Micturition Symptoms and Maximum Flow Rate in Men With Benign Prostatic Hyperplasia/Lower Urinary Tract Symptoms
Purpose Individual anatomical structural variations, including intravesical prostatic protrusion (IPP), prostatic urethral angle (PUA), prostatic urethral length, or prostatic apex shape, were correlated with micturition symptoms. We aimed to investigate the effects of these variables on micturition symptoms in men with benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS). Methods This observational study was based on data from 263 men with the first visit to health promotion center and without BPH/LUTS treatment between March 2020 and September 2022. A multivariate analysis was performed to determine the variables affecting total international prostate symptom score, maximum flow rate (Qmax), and voiding efficacy (postvoid residual volume to total bladder volume ratio). Results Of 263 patients, decreasing PUA increases the severity of international prostate symptoms score (mild, 141.9°; moderate, 136.0°; severe, 131.2°; P<0.015). A multivariate analysis reported that the total international prostate symptom score was correlated with age (P=0.002), PUA (P=0.007), and Qmax (P=0.008). Qmax was negatively associated with IPP (P=0.002). In subanalysis for large prostate volume (≥30 mL, n=81), international prostate symptom score was correlated with PUA (P=0.013), Qmax was correlated with prostatic apex shape (P=0.017), and length of proximal prostatic urethra (P=0.007). IPP was not identified as a significant factor. For small prostate volume (<30 mL, n=182), age (P=0.011) and prostate volume (P=0.004) are correlated with increasing Qmax. Conclusions This study presented that individual anatomical structure variations influenced the micturition symptoms according to prostate volume. To identify the major resistant factors in men with BPH/LUTS, further studies are required to investigate which components played a role in major resistant factors for micturition symptoms
Mind Bomb 1-Expressing Intermediate Progenitors Generate Notch Signaling to Maintain Radial Glial Cells
SummaryNotch signaling is critical for the stemness of radial glial cells (RGCs) during embryonic neurogenesis. Although Notch-signal-receiving events in RGCs have been well characterized, the signal-sending mechanism by the adjacent cells is poorly understood. Here, we report that conditional inactivation of mind bomb-1 (mib1), an essential component for Notch ligand endocytosis, in mice using the nestin and hGFAP promoters resulted in complete loss of Notch activation, which leads to depletion of RGCs, and premature differentiation into intermediate progenitors (IPs) and finally neurons, which were reverted by the introduction of active Notch1. Interestingly, Mib1 expression is restricted in the migrating IPs and newborn neurons, but not in RGCs. Moreover, sorted Mib1+ IPs and neurons can send the Notch signal to neighboring cells. Our results reveal that not only newborn neurons but also IPs are essential Notch-ligand-presenting cells for maintaining RGC stemness during both symmetric and asymmetric divisions
Recessive C10orf2 mutations in a family with infantile-onset spinocerebellar ataxia, sensorimotor polyneuropathy, and myopathy
Recessive mutations in chromosome 10 open reading frame 2 (C10orf2) are relevant in infantile-onset spinocerebellar ataxia (IOSCA). In this study, we investigated the causative mutation in a Korean family with combined phenotypes of IOSCA, sensorimotor polyneuropathy, and myopathy. We investigated recessive mutations in a Korean family with two individuals affected by IOSCA. Causative mutations were investigated using whole exome sequencing. Electrophysiological analyses and muscle and nerve biopsies were performed, along with magnetic resonance imaging (MRI) of the brain and lower extremities. Compound heterozygous mutations c.1460C>T and c.1485-1G>A in C10orf2 were identified as causative of IOSCA. Skeletal muscle showed mitochondrial DNA (mtDNA) deletions. Both patients showed a period of normal development until 12–15 months, followed by ataxia, athetosis, hearing loss, and intellectual disability. Electrophysiological findings indicated motor and sensory polyneuropathies. Muscle biopsy revealed variations in the size and shape of myofibers with scattered, small, and angulated degenerating myofibers containing abnormal mitochondria; these observations are consistent with myopathy and may be the result of mtDNA deletions. Sural nerve biopsy revealed an axonal neuropathy. High-signal-intensity lesions in the middle cerebellar peduncles were correlated with clinical severity, and MRI of the lower legs was compatible with the hypothesis of length-dependent axonal degeneration. We identified novel compound heterozygous mutations of the C10orf2 gene as the cause of IOSCA with sensorimotor polyneuropathy and myopathy. Signs of motor neuropathy and myopathy were discovered for the first time in IOSCA patients with C10orf2 mutations. These results suggest that the clinical spectrum of IOSCA caused by C10orf2 mutations may be more variable than previously reported. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10048-014-0405-1) contains supplementary material, which is available to authorized users
Fate of untreated asymptomatic osteonecrosis of the femoral head
BACKGROUND: Magnetic resonance imaging has made it possible to detect asymptomatic lesions of osteonecrosis of the femoral head before abnormalities appear on plain radiographs. The extent of a necrotic lesion is known to be an important prognostic factor. In this study, we evaluated the fate of untreated asymptomatic osteonecrosis of the femoral head with an emphasis on the size of the lesion. We hypothesized that a lesion smaller than a certain size would not progress to symptomatic disease. METHODS: One hundred and five initially asymptomatic hips of patients with bilateral nontraumatic osteonecrosis of the femoral head who had been followed without any treatment for at least five years or until pain developed were enrolled in this study. The extent of a lesion was estimated according to the area of the lesion based on a two-dimensional analysis on magnetic resonance images or on plain radiographs at the time of diagnosis. RESULTS: Sixty-two hips became symptomatic, and forty-three hips remained asymptomatic for more than five years (average, eight years and seven months). Of the twenty-one hips with a small necrotic lesion (50% of the area of the femoral head), fifty became painful. Forty-six of the sixty-two hips that became symptomatic required surgery. Pain developed within five years after the diagnosis in fifty-eight (94%) of the sixty-two symptomatic hips. CONCLUSIONS: No treatment appears to be necessary for asymptomatic necrotic lesions with an area smaller than 30% of the femoral head, as the vast majority of these lesions will remain asymptomatic for more than five years
Mind bomb 1 in the lymphopoietic niches is essential for T and marginal zone B cell development
Notch signaling regulates lineage decisions at multiple stages of lymphocyte development, and Notch activation requires the endocytosis of Notch ligands in the signal-sending cells. Four E3 ubiquitin ligases, Mind bomb (Mib) 1, Mib2, Neuralized (Neur) 1, and Neur2, regulate the Notch ligands to activate Notch signaling, but their roles in lymphocyte development have not been defined. We show that Mib1 regulates T and marginal zone B (MZB) cell development in the lymphopoietic niches. Inactivation of the Mib1 gene, but not the other E3 ligases, Mib2, Neur1, and Neur2, abrogated T and MZB cell development. Reciprocal bone marrow (BM) transplantation experiments revealed that Mib1 in the thymic and splenic niches is essential for T and MZB cell development. Interestingly, when BM cells from transgenic Notch reporter mice were transplanted into Mib1-null mice, the Notch signaling was abolished in the double-negative thymocytes. In addition, the endocytosis of Dll1 was impaired in the Mib1-null microenvironment. Moreover, the block in T cell development and the failure of Dll1 endocytosis were also observed in coculture system by Mib1 knockdown. Our study reveals that Mib1 is the essential E3 ligase in T and MZB cell development, through the regulation of Notch ligands in the thymic and splenic microenvironments
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