364 research outputs found

    Heat Transfer in Laser Tumor Excision

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    Cancer is an ongoing disease that is present in a majority of the population. Laser surgery provides minimally invasive techniques to excise tumors in humans. This method allows quicker recoveries and fewer complications. This study analyzes the effectiveness of excision of tumor tissue using a CO2 laser. By using computer aided design and finite element analysis, we model a cylindrical tumor tissue with 0.3cm in diameter and height. A flux of 282mmW from the laser and a convection coefficient of KmmW???26105 were applied when designing this model. Our results produced temperature contour plots at several time intervals, all showing precise laser excision with minimal inadvertent tissue damage (less than 0.006 mm in depth after excising approximately 0.15 mm of tissue in depth). Sensitivity analysis indicate that changes in material properties such as conductivity, convection, specific heat, density, and laser power have minimal affects on the temperature profile

    On the Infra-Red Spectra of Solutions of O-Chlorophenol and Phenol

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    <p><b>a–d Immunoblotting of different proteins in control and study groups of gastric adenocarcinoma.</b> (a) Representative immunoblots of different target proteins in gastric epithelium of the control and study groups (from patients 1 to 4) with GAPDH as a loading control. M, marker. Relative protein abundance of NKA α1 (b), NKA β1 (c), and E-cadherin (d) in gastric epithelium of the control and study groups. The asterisks indicate a significant difference between the control and study groups. Values were expressed as the means ± SEM. A.u., arbitrary unit. ***, P < 0.001; ****, P < 0.0001.</p

    Sediment Budget in the Taiwan Strait with High Fluvial Sediment Inputs from Mountainous Rivers: New Observations and Synthesis

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    The shallow Taiwan Strait at the southern opening of the East China Sea (ECS) receives abundant sediments from turbid mountainous rivers in Taiwan. The volume of sediment is among the highest sediment yields on the global surface. This large amount of sediment discharged from modern Taiwan (range: 175 - 380 Mt y-1 based on 50-yr data) is comparable to that discharged from Changjaing (500 Mt y-1-decreasing in recent decades), underscoring the importance of sediment budget in the Taiwan Strait and sediment flux from Taiwan into the ECS.We documented fluvial mud and sand concentrations during flash flooding with our observations indicating that fluvial materials in Taiwan¡¦s rivers are chiefly composed of mud (> 70 and up to 98 ). By contrast, sand fraction dominates (> 85 for most stations) surface sediments in the Taiwan Strait. Super typhoon Herb alone delivered 130 Mt of sediments from Choshui, the largest river in Taiwan, yet only insignificant amounts of mud were found at the river mouth six months later. The actions of waves, tides, and currents apparently prevent the deposition of fine grained sediments. Assuming sand occupied 30 (the maximum) of the 60 Mt y-1 total sediment input from major western Taiwanese rivers, our annual budget estimate shows that the amount of sand input (18 5 Mt y-1) is comparable to the burial output of sand (12 10 Mt y-1). However, mud burial (6 5 Mt y-1) in the strait is far below the estimated mud input (42 11 Mt y-1), resulting in a significant shortfall. Hydrodynamic conditions were synthesized to explain the distribution pattern of limited mud patches in the strait and to reveal potential pathways by which fine-grain sediment transportation takes place in the seas surrounding Taiwan. A significant shortfall in the mud budget in the Taiwan Strait suggests that ~85 of the fluvial mud left the strait. Alternatively, the 50-year modern sediment flux data used in this study reflects exacerbated sediment flux due to human activity and is possibly too high to represent loads during pre-Anthropocene. Additional studies are needed to explore the flux and fate of mud in and surrounding Taiwan over a longer time scale

    Acute effect of electroacupuncture at the Zusanli acupoints on decreasing insulin resistance as shown by lowering plasma free fatty acid levels in steroid-background male rats

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    <p>Abstract</p> <p>Background</p> <p>Insulin sensitivity has been enhanced by electroacupuncture (EA) in rats, but the EA phenomenon in an insulin resistant state is still unclear. This study reports the use of a large dose of prednisolone to evaluate the effects of EA in a state of insulin resistance.</p> <p>Methods</p> <p>The plasma levels of free fatty acids (FFAs) were estimated in steroid-background rats (SBRs) and compared with those in healthy rats treated with normal saline. In addition, plasma glucose and endogenous insulin levels were assayed to calculate the homeostasis model assessment (HOMA) index. Intravenous glucose tolerance test (IVGTT) was carried out to compare glucose tolerance. The SBRs were randomly divided into EA-treatment and non-EA treatment groups and 15-Hz EA was applied to the bilateral Zusanli acupoints to investigate its effects on insulin resistance. In addition to an insulin challenge test (ICT) and IVGTT, the plasma levels of FFAs were measured and western blot was performed to help determine the effects of EA on the insulin resistant state.</p> <p>Results</p> <p>The plasma levels of FFAs increased markedly in SBRs, the HOMA index was markedly higher, and glucose tolerance was impaired. EA improved glucose tolerance and insulin sensitivity by decreasing the plasma levels of FFAs. Further, the insulin signaling proteins (IRS1) and glucose transporter isoform protein (GLUT4) in skeletal muscle inhibited by prednisolone recovered after EA.</p> <p>Conclusion</p> <p>Insulin resistance was successfully induced by a large dose of prednisolone in male rats. This insulin resistance can be improved by 15 Hz EA at the bilateral Zusanli acupoints, as shown by decreased plasma levels of FFAs.</p

    Estrogen Augments Shear Stress–Induced Signaling and Gene Expression in Osteoblast-like Cells via Estrogen Receptor–Mediated Expression of β1-Integrin

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    Estrogen and mechanical forces are positive regulators for osteoblast proliferation and bone formation. We investigated the synergistic effect of estrogen and flow-induced shear stress on signal transduction and gene expression in human osetoblast-like MG63 cells and primary osteoblasts (HOBs) using activations of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and expressions of c-fos and cyclooxygenase-2 (I) as readouts. Estrogen (17β-estradiol, 10 nM) and shear stress (12 dyn/cm2) alone induced transient phosphorylations of ERK and p38 MAPK in MG63 cells. Pretreating MG63 cells with 17β-estradiol for 6 hours before shearing augmented these shear-induced MAPK phosphorylations. Western blot and flow cytometric analyses showed that treating MG63 cells with 17β-estradiol for 6 hrs induced their β1-integrin expression. This estrogen-induction of β1-integrin was inhibited by pretreating the cells with a specific antagonist of estrogen receptor ICI 182,780. Both 17β-estradiol and shear stress alone induced c-fos and Cox-2 gene expressions in MG63 cells. Pretreating MG63 cells with 17β-estradiol for 6 hrs augmented the shear-induced c-fos and Cox-2 expressions. The augmented effects of 17β-estradiol on shear-induced MAPK phosphorylations and c-fos and Cox-2 expressions were inhibited by pretreating the cells with ICI 182,780 or transfecting the cells with β1-specific small interfering RNA. Similar results on the augmented effect of estrogen on shear-induced signaling and gene expression were obtained with HOBs. Our findings provide insights into the mechanism by which estrogen augments shear stress responsiveness of signal transduction and gene expression in bone cells via estrogen receptor–mediated increases in β1-integrin expression. © 2010 American Society for Bone and Mineral Research

    Application of importance-satisfaction analysis and influence-relations map to evaluate design delay factors

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    Design delays can negatively influence the total completion time of a facility construction project. Knowing the factors to which design delays are most sensitive supports the time management of designs. However, factors that cause design delays are several and interrelated. This study proposes a new model to identify key factors that drive design delays. The core of the model integrates importance-satisfaction analysis (ISA) and an influence-relations map (IRM). The ISA evaluates the performance of each delay factor, while the IRM captures the causal relationships among factors. Additionally, the IRM is generated using a decision making trial and evaluation laboratory technique (DEMATEL). The model is applied to a real-world high-tech facility construction project to indicate the strengths of the model. In this investigation, four first-level delay factors and 17 second-level delay sub-factors are derived. The factor of “organization's decision making and budget constraints” is identified as the key driver of design delays in the project of interest. The results support management in determining which problem factors should be given priority attention. The proposed model can be employed in other decision-making situations that involve interrelated factors

    Acute Paraparesis Caused by a Giant Cell Tumor of the Thoracic Spine

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    AbstractGiant cell tumor (GCT) is a benign but locally aggressive skeletal neoplasm of young adults. GCT located in the spine is relatively rare and may need a combination of surgical and adjunctive therapies. Here we present a patient who had intermittent thoracic back pain for two weeks and experienced an acute episode of decreased muscle power of both lower limbs. Magnetic resonance (MR) imaging examinations of the thoracic spine revealed that the patient had severe spinal canal compression caused by pathological fracture due to a tumor within the seventh thoracic vertebra. She underwent an emergent surgical intervention for total removal of the tumor and spinal reconstruction with autologous rib grafts and instruments. Postoperatively, the patient made an uneventful recovery of muscle power of bilateral lower limbs. She subsequently received adjuvant radiotherapy. In a follow-up period of 36 months, the patient had no clinical or radiological evidence of tumor recurrence. Even though spinal location for GCT is a rare event, it should be included in the differential diagnosis in patients with osteolytic lesions or pathological fractures of the vertebra, especially in young female patients sustaining no trauma who had a clinical history of persistent low back pain

    Serologic Status for Pandemic (H1N1) 2009 Virus, Taiwan

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    We studied preexisting immunity to pandemic (H1N1) 2009 virus in persons in Taiwan. A total of 18 (36%) of 50 elderly adults in Taiwan born before 1935 had protective antibodies against currently circulating pandemic (H1N1) 2009 virus. Seasonal influenza vaccines induced antibodies that did not protect against pandemic (H1N1) 2009 virus
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