4,627 research outputs found
Bandwidth Enhancement of Single-Layer Microstrip Reflectarrays with Multi-Dipole Elements
The gain bandwidth limit of a single-layer microstrip reflectarray is analyzed using multi-dipole elements. By observing the reflection phase characteristics of the multi-dipole elements with different numbers of dipoles, it is shown how the bandwidth can be enhanced by increasing the number of element resonant structures. The fundamental limit of the bandwidth enhancement is then derived by analyzing the coupling between the surface wave and the incident plane wave. It is shown that the surface wave can be excited even with the plane wave of normal incidence on the reflectarray and that the excitation frequency of the surface wave is dominated by array parameters and is almost independent of the number of resonant structures. The degradation of the element reflection characteristics caused by the surface wave, which limits the reflectarray bandwidth, is investigated. By comparing the radiation characteristics of three reflectarrays with three-, five-, and seven-dipole element, respectively, the analysis of the bandwidth enhancement and its limit is verified. The measured 1-dB gain bandwidth of the three-dipole element reflectarray is 25.12%, and the bandwidth is enhanced to 33.52% with the five-dipole element. However, because of the surface wave, no further bandwidth enhancement is achieved when the seven-dipole element is used, as predicted
THE ANALYSIS OF OCULAR MOVEMENT FOR THE DYNAMIC POSTURAL CONTROL OF TURN MOTION ON THE BALANCE BEAM
This study demonstrated the importance of dynamic postural balancing and ocular movement in a turn motion on the balance beam using a manufactured wireless EOG measuring system with three female gymnasts. This study found that among the dynamic postural control variables, angular displacement and ocular movement were closely related. During a turn motion, the ocular movement was in opposite direction of the angular displacement of head and trunk along the medio-lateral axis. This resulted from the gymnastās effort to stare at the end of the balance beam or the front in order to keep balance. The change of angular displacement of head around the medio-lateral axis and vertical axis was in opposite direction of the ocular movement. When the motion was successful, the gymnasts performed a spotting motion
Markedly enhanced intratumoral spread and antitumor effect of oncolytic adenovirus expressing decorin
With the aim of improving viral distribution and tumor penetration, we have engineered decorin expressing replication-incompetent (dl-LacZ-DCNG) and -competent (Ad-[DELTA]E1B-DCNG) adenoviruses. In both tumor spheroids and established solid tumors in vivo, administration of dl-LacZ-DCNG resulted in greater transduction efficiency and viral spread throughout the tumor mass. Ad-[DELTA]E1B-DCNG also enhanced viral distribution and tumor spread, leading to an increased anti-tumor effect and survival advantage. Upon histological analysis, Ad-[DELTA]E1B-DCNG also elicited greater percentage of apoptotic cells and extensive necrosis compared to those from untreated or control virus-treated tumors. Furthermore, Ad-[DELTA]E1B-DCNG substantially decreased extracellular matrix components within the tumor tissue, while normal tissue adjacent to the tumor was not affected. Finally, intratumoral administration of Ad-[DELTA]E1B-DCNG did not enhance but inhibited the formation of pulmonary metastases of B16BL6 melanoma cells in mice. Taken together, these data demonstrate the utility of decorin as a dispersion agent and suggest its utility and potential in improving the efficacy of replicating adenovirus-mediated cancer gene therapy
Boundary Work and Transactive Memory Systems in Teams: Moderating Effects of the Visibility Affordance
Individuals in work teams frequently cross boundaries across teams, often by using information and communication technologies (ICTs). The current study investigates the effects of membersā boundary work and the visibility affordance of teamsā ICTs on Transactive Memory Systems (TMS) in teams. Survey data from 212 full-time employees whose work hours were divided between multiple teams reveals that boundary spanning enhances the focal teamās TMS credibility and specialization and negatively influences TMS coordination. Additionally, boundary reinforcement positively affects TMS credibility and coordination. The visibility affordance has a direct positive impact on all three dimensions of TMS and a moderating effect for boundary reinforcement such that higher visibility overrides the positive direct effect of boundary reinforcement on TMS. These findings suggest that different types of boundary work contribute to different dimensions of TMS and that teams might consider prioritizing the use of ICTs with high visibility to enhance their TMS
Investigation of the SH3BP2 Gene Mutation in Cherubism
Cherubism is a rare developmental lesion of the jaw that is generally inherited as an autosomal dominant trait. Recent studies have revealed point mutations in the SH3BP2 gene in cherubism patients. In this study, we examined a 6-year-old Korean boy and his family. We found a Pro418Arg mutation in the SH3BP2 gene of the patient and his mother. A father and his 30-month-old younger brother had no mutations. Immunohistochemically, the multinucleated giant cells proved positive for CD68 and tartrate-resistant acid phosphatase (TRAP). Numerous spindle-shaped stromal cells expressed a ligand for receptor activator of nuclear factor kB (RANKL), but not in multinucleated giant cells. These results provide evidence that RANKL plays a critical role in the differentiation of osteoclast precursor cells to multinucleated giant cells in cherubism. Additionally, genetic analysis may be a useful method for differentiation of cherubism.</p
Short-hairpin RNA-induced suppression of adenine nucleotide translocase-2 in breast cancer cells restores their susceptibility to TRAIL-induced apoptosis by activating JNK and modulating TRAIL receptor expression
Pulmonary Venous Malformation in a 4-Year-Old Boy: a Case Report
We report a case of a pulmonary venous malformation in a 4-year-old boy who presented with recurrent pneumonia. A radiograph revealed a right infrahilar mass and a hyperlucent right lung. Computed tomography (CT) demonstrated a mass containing intensely enhancing areas and multiple phleboliths located in the right lower lobe and encasing the right bronchus and right inferior pulmonary vein. Magnetic resonance imaging (MRI) precisely revealed the mass demarcation. A right lower lobectomy was performed and a pathological examination confirmed the diagnosis of a venous malformation. To the best of our knowledge, a venous malformation in pulmonary tissue has not been reported in the English literature. Herein, we report a case of a pulmonary venous malformation, with the radiograph, CT, MRI, and blood pool scan findings, along with its pathologic correlation
Stratifying the early radiologic trajectory in dyspneic patients with COVID-19 pneumonia
OBJECTIVE: This study aimed to stratify the early pneumonia trajectory on chest radiographs and compare patient characteristics in dyspneic patients with coronavirus disease 2019 (COVID-19).
MATERIALS AND METHODS: We retrospectively included 139 COVID-19 patients with dyspnea (87 men, 62.7+/-16.3 years) and serial chest radiographs from January to September 2020. Radiographic pneumonia extent was quantified as a percentage using a previously-developed deep learning algorithm. A group-based trajectory model was used to categorize the pneumonia trajectory after symptom onset during hospitalization. Clinical findings, and outcomes were compared, and Cox regression was performed for survival analysis.
RESULTS: Radiographic pneumonia trajectories were categorized into four groups. Group 1 (n = 83, 59.7%) had negligible pneumonia, and group 2 (n = 29, 20.9%) had mild pneumonia. Group 3 (n = 13, 9.4%) and group 4 (n = 14, 10.1%) showed similar considerable pneumonia extents at baseline, but group 3 had decreasing pneumonia extent at 1-2 weeks, while group 4 had increasing pneumonia extent. Intensive care unit admission and mortality were significantly more frequent in groups 3 and 4 than in groups 1 and 2 (P \u3c .05). Groups 3 and 4 shared similar clinical and laboratory findings, but thrombocytopenia ( \u3c 150x103/muL) was exclusively observed in group 4 (P = .016). When compared to groups 1 and 2, group 4 (hazard ratio, 63.3; 95% confidence interval, 7.9-504.9) had a two-fold higher risk for mortality than group 3 (hazard ratio, 31.2; 95% confidence interval, 3.5-280.2), and this elevated risk was maintained after adjusting confounders.
CONCLUSION: Monitoring the early radiologic trajectory beyond baseline further prognosticated at-risk COVID-19 patients, who potentially had thrombo-inflammatory responses
- ā¦