1,582 research outputs found
Ultra-Low Temperature Chillers for Semiconductor Manufacturing Process
The growth of the semiconductor market and advancement of manufacturing technology have led to an increase in wafer size and highly integrated semiconductor devices. The temperature of the supplied cooling medium from the chiller that removes the heat produced in the semiconductor manufacturing process is required to be at a lower level because of the high integration. The Joule-Thomson cooling cycle, which uses a mixed refrigerant (MR) to produce the cooling medium at a level of −100°C required for the semiconductor process, has recently gained attention. When a MR is used, the chiller’s performance is heavily influenced by the composition and proportions of the refrigerant charged to the chiller system. Therefore, this paper introduces a cooling cycle that uses an MR to achieve the required low temperature of −100°C in the semiconductor manufacturing process and provides the results of simple experiments to determine the effects of different MR compositions
Carpal Tunnel Syndrome Caused by Space Occupying Lesions
PURPOSE: To evaluate the diagnosis and treatment of the carpal tunnel syndrome (CTS) due to space occupying lesions (SOL).
MATERIALS and METHODS: Eleven patients and 12 cases that underwent surgery for CTS due to SOL were studied retrospectively. We excluded SOL caused by bony lesions, such as malunion of distal radius fracture, volar lunate dislocation, etc. the average age was 51 years. There were 3 men and 8 women. Follow-up period was 12 to 40 months with an average of 18 months. the diagnosis of CTS was made clinically and electrophysiologically. in patients with swelling or tenderness on the area of wrist flexion creases, magnetic resonance imaging (MRI) and/or computed tomogram (CT) were additionally taken as well as the carpal tunnel view. We performed conventional open transverse carpal ligament release and removal of SOL.
RESULTS: the types of lesion confirmed by pathologic examination were; tuberculosis tenosynovitis in 3 cases, nonspecific tenosynovitis in 2 cases, and gout in one case. Other SOLs were tumorous condition in five cases, and abnormal palmaris longus hypertrophy in 1 case. Tumorous conditions were due to calcifying mass in 4 cases and ganglion in 1 case. Following surgery, all cases showed alleviation of symptom without recurrence or complications.
CONCLUSION: in cases with swelling or tenderness on the area of wrist flexion creases, it is important to obtain a carpal tunnel view, and MRI and/or CT should be supplemented in order to rule out SOLs around the carpal tunnel, if necessary.ope
Massive transfusion protocol: the reason it is necessary
Objective. The purpose of this study is to identify problems of emergency transfusion at the bedside and to determine need for massive transfusion protocol.
Methods. We included patients who met the criteria for “trauma team activation” and were admitted to division of trauma. The amount of blood product transfused in each unit was investigated for balanced transfusion. We also investigated the compliance with assessment of blood consumption score. The correlation between the time elapsed from patient visit to first transfusion order and time elapsed from first transfusion order to transfusion start was analyzed. Finally, we investigated various factors which serve to influence the decision-making process regarding early transfusion order.
Results. Ratio of packed Red blood cells (pRBC): Fresh frozen plasma (FFP) was well-balanced, but platelet transfusion done was much lower than pRBC and FFP in emergency room. The application of emergency blood release did not match the criteria of assessment of blood consumption (ABC) score. The time from the first transfusion order to the transfusion start was found to be constant irrespective of time from patient visit to first transfusion order. And, the time from the first transfusion order to transfusion start did not differ significantly among patients with early transfusion order and delayed transfusion order. Only systolic blood pressure of < 90 mmHg was identified as a major predictor for early transfusion order.
Conclusion. Balanced transfusion is not easy and emergency transfusion could be delayed at the bedside. Integrated and systematic structures for massive transfusion protocol would be invaluable and indispensable
Anticholinesterase Therapy for Patients with Ophthalmoplegia Following Snake Bites: Report of Two Cases
Although ophthalmoplegia following snake bites is not indicative of a serious neurotoxic complication, symptoms of diplopia, dizziness and ocular discomfort can be emotionally devastating for patients. The authors experienced two cases of ophthalmoplegia following snake bites in Korea. The patients complained of diplopia that had developed several hours after the snake bites. The diplopia did not improve with antivenom treatment, but resolved completely after several injections of neostigmine
A copula method for modeling directional dependence of genes
<p>Abstract</p> <p>Background</p> <p>Genes interact with each other as basic building blocks of life, forming a complicated network. The relationship between groups of genes with different functions can be represented as gene networks. With the deposition of huge microarray data sets in public domains, study on gene networking is now possible. In recent years, there has been an increasing interest in the reconstruction of gene networks from gene expression data. Recent work includes linear models, Boolean network models, and Bayesian networks. Among them, Bayesian networks seem to be the most effective in constructing gene networks. A major problem with the Bayesian network approach is the excessive computational time. This problem is due to the interactive feature of the method that requires large search space. Since fitting a model by using the copulas does not require iterations, elicitation of the priors, and complicated calculations of posterior distributions, the need for reference to extensive search spaces can be eliminated leading to manageable computational affords. Bayesian network approach produces a discretely expression of conditional probabilities. Discreteness of the characteristics is not required in the copula approach which involves use of uniform representation of the continuous random variables. Our method is able to overcome the limitation of Bayesian network method for gene-gene interaction, i.e. information loss due to binary transformation.</p> <p>Results</p> <p>We analyzed the gene interactions for two gene data sets (one group is eight histone genes and the other group is 19 genes which include DNA polymerases, DNA helicase, type B cyclin genes, DNA primases, radiation sensitive genes, repaire related genes, replication protein A encoding gene, DNA replication initiation factor, securin gene, nucleosome assembly factor, and a subunit of the cohesin complex) by adopting a measure of directional dependence based on a copula function. We have compared our results with those from other methods in the literature. Although microarray results show a transcriptional co-regulation pattern and do not imply that the gene products are physically interactive, this tight genetic connection may suggest that each gene product has either direct or indirect connections between the other gene products. Indeed, recent comprehensive analysis of a protein interaction map revealed that those histone genes are physically connected with each other, supporting the results obtained by our method.</p> <p>Conclusion</p> <p>The results illustrate that our method can be an alternative to Bayesian networks in modeling gene interactions. One advantage of our approach is that dependence between genes is not assumed to be linear. Another advantage is that our approach can detect directional dependence. We expect that our study may help to design artificial drug candidates, which can block or activate biologically meaningful pathways. Moreover, our copula approach can be extended to investigate the effects of local environments on protein-protein interactions. The copula mutual information approach will help to propose the new variant of ARACNE (Algorithm for the Reconstruction of Accurate Cellular Networks): an algorithm for the reconstruction of gene regulatory networks.</p
Impact of Toxocariasis in Patients with Unexplained Patchy Pulmonary Infiltrate in Korea
Toxocariasis is one of the causes of pulmonary eosinophilic infiltrate that is increasing in Korea. This study was designed to identify the prevalence of toxocara seropositivity in patients with unexplained pulmonary patchy infiltrate and to evaluate associated factors. We evaluated 102 patients with unexplained pulmonary patchy infiltrate on chest computed tomography (CT) scan. As a control set, 116 subjects with normal chest CT were also evaluated. History of allergic disease, drug use, parasitic disease and raw cow liver intake were taken. Blood eosinophil count and total IgE level were measured. Specific serum IgG antibody to Toxocara canis larval antigen and specific IgG antibodies to 4 other parasites were measured by enzyme-linked immunosorbent assay (ELISA). In the infiltrate group, 66.7% subjects were toxocara seropositive whereas 22.4% of the control group were seropositive (p<0.001). In the infiltrate group, patients with a history of eating raw cow liver (odds ratio [OR], 7.8) and patients with eosinophilia (OR, 5.2) had a higher incidence of toxocara seropositivity. Thirty-five percent of toxocara seropositive patients with infiltrate exhibited migrating infiltrate and 48% had decreased infiltrate on the follow-up CT. We recommend that toxocara ELISA should be performed in patients with unexplained pulmonary patchy infiltrate, and that the eating of raw cow liver should be actively discouraged
Correlation of hypoxia inducible transcription factor in breast cancer and SUVmax of F-18 FDG PET/CT
BACKGROUND: Tumor hypoxia induces the expression of several genes via the hypoxia-inducible transcription factor-1 alpha (HIF-1a). It is associated with the prognosis of several cancers. We studied the immunohistochemical expression of HIF-1a in patients with invasive ductal cancer (IDC) of the breast and the possible correlation with the maximum standardized uptake value of the primary tumor (pSUVmax) as well as other biological parameters. Prognostic significance of pSUVmax and expression of HIF-1a for the prediction of progression-free survival (PFS) was also assessed.
MATERIAL AND METHODS: Two-hundred seven female patients with IDC who underwent pretreatment fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) were enrolled. The pSUVmax was compared with clinicopathological parameters including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), axillary lymph node (LN) metastasis, stage and HIF-1a expression. The prognostic value of pSUVmax for PFS was assessed using the Kaplan-Meier method.
RESULTS: pSUVmax was significantly higher in patients with HIF-1a expression ≥ 2 compared to patients with HIF-1a expression < 2 (5.2 ± 4.5 vs. 3.7 ± 3.1, p = 0.008). pSUVmax was also significantly higher in higher stage (p < 0.000001), ER-negative tumors (p < 0.0001), PR-negative tumors (p = 0.0011) and positive LN metastasis (p = 0.0013). pSUVmax was significantly higher in patients with progression compared to patients who were disease-free (6.8 ± 4.4 vs. 4.1 ± 3.7, p = 0.0005). A receiver-operating characteristic curve demonstrated a pSUVmax of 6.51 to be the optimal cutoff for predicting PFS (sensitivity: 53.6%, specificity: 86.0%). Patients with high pSUVmax (> 6.5) had significantly shorter PFS compared to patients with low pSUVmax (p < 0.0001).
CONCLUSIONS: pSUVmax on pretreatment F-18 FDG PET/ CT reflect expression of HIF-1a and can be used as a good surrogate marker for the prediction of progression in patients with IDC. The amount of FDG uptake is determined by the presence of glucose metabolism and hypoxia in breast cancer cell
GAIT ASYMMETRY IN CHILDREN WITH DOWN SYNDROME
It has been reported that approximately 80% of children with Down syndrome (OS) exhibit gait problems (Matteo, 2002), characterized by flat-footed contact with no heel-strike, excessive abduction of the leg in the swing phase, and abnormal knee and hip f1exions throughout the gait cycle (Parker et aI., 1986). Due to muscle hypotonia, muscle weakness, !igamentous laXity, and other orthopedic abnormalities, different gait characteristics exist. The purpose of this study was to investigate the gait (walking and running) asymmetry in children with OS
Radiation exposure from computed tomography in blunt trauma patients
Introduction. Computed tomography (CT) has many diagnostic advantages, spurring growth in the number of CT examinations.
As the use of CT increases, the potential for radiation-induced adverse effects has become an issue. The primary
objective of this study was to assess the liberal use of CT induced radiation exposure in patients with multiple blunt traumas.
The secondary objective was to investigate the factors affecting the estimated effective dose resulting from CTs unrelated
to final diagnosis.
Methods. Using data from our hospital information system, we selected patients assigned a trauma code, according to the
Korean Standard Classification of Diseases, and with three or more body lesions assessed by CT at the same time in the
emergency department. Each CT conducted was categorized into ‘CT related to the final diagnosis’ or ‘CT unrelated to
final diagnosis’. The characteristics and estimated effective dose of CTs unrelated to the final diagnosis were analyzed. The
factors affecting the estimated effective dose of CTs unrelated to final diagnosis were investigated.
Results. More than half of all CT examinations were not associated with the final diagnosis. The additional estimated effective
dose due to CTs being unrelated to the final diagnosis in each patient was a sufficient amount of radiation exposure to
increase the possibility of fatal cancer.
Conclusion. A considerable number of CT scans were unrelated to the patient’s final diagnosis, which exposes the patient
to additional radiation exposure
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