96 research outputs found
Performance metrics in professional baseball pitchers before and after surgical treatment for neurogenic thoracic outlet syndrome
Natriuretic peptide receptor-C is up-regulated in the intima of advanced carotid artery atherosclerosis
OBJECTIVE: Natriuretic peptide receptor-C (NPR-C/NPR-3) is a cell surface protein involved in vascular remodelling that is up-regulated in atherosclerosis. NPR-C expression has not been well characterized in human carotid artery occlusive lesions. We hypothesized that NPR-C expression correlates with intimal features of vulnerable atherosclerotic carotid artery plaque. METHODS: To test this hypothesis, we evaluated NPR-C expression by immunohistochemistry (IHC) in carotid endarterectomy (CEA) specimens isolated from 18 patients. The grade, location, and co-localization of NPR-C in CEA specimens were evaluated using two tissue analysis techniques. RESULTS: Relative to minimally diseased CEA specimens, we observed avid NPR-C tissue staining in the intima of maximally diseased CEA specimens (65%; p=0.06). Specifically, maximally diseased CEA specimens demonstrated increased NPR-C expression in the superficial intima (61%, p=0.17), and deep intima (138% increase; p=0.05). In the superficial intima, NPR-C expression significantly co-localized with vascular smooth muscle cells (VSMCs) and macrophages. The intensity of NPR-C expression was also higher in the superficial intima plaque shoulder and cap regions, and significantly correlated with atheroma and fibroatheroma vulnerable plaque regions (β=1.04, 95% CI=0.46, 1.64). CONCLUSION: These findings demonstrate significant NPR-C expression in the intima of advanced carotid artery plaques. Furthermore, NPR-C expression was higher in vulnerable carotid plaque intimal regions, and correlate with features of advanced disease. Our findings suggest that NPR-C may serve as a potential biomarker for carotid plaque vulnerability and progression, in patients with advanced carotid artery occlusive disease
Modulation of African lightning and rainfall by the global five day wave
Thesis (S.M. and S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references (leaves 169-176).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Using a field station in Rhode Island, we record electromagnetic transients caused by global mesoscale lightning activity in the Schumann resonance band (3Hz-50Hz). For this thesis, mesoscale lightning flashes originating in Africa were analyzed and compared to the phase and amplitude of a five day global pressure wave and African easterly waves. Evidence was also presented for the mesoscale lightning to be correlated with African rainfall and kinetic energy. The five day global pressure wave was located in terms of phase and amplitude for every day of the years 1989, 1996, and 1998. This global pressure wave seems to have a certain phase relationship with African convection and could possibly be modulating rainfall and lightning by a factor of two. Evidence is also presented for the possible modulation of African easterly waves by the five day wave.by Akash C. Patel.S.M.and S.B
MATLAB-Simulink environment based power quality improvement in photovoltaic system using multilevel inverter
Introduction. In this world of technical advancement, conventional resources are at the stage of destruction. To avoid such problems, we are going to use an alternative energy source namely solar by photovoltaic effect. The demand for multilevel inverters increased as they are used for different dynamic (high) voltage and dynamic (high) power appliances as they are capable of producing the output wave shape with low total harmonic distortion. Novelty. A new multilevel inverter is used in adding a (bidirectional) two way switch in between the capacitor and a traditional H-bridge module. This produces a better sine wave. By series connection of these two H-bridge modules, nine levels output voltage including zero is possible. The purpose of the proposed topology is reduction in the number of switches and it gives the good result with comparatively less power loss when it is compared with the other normal basic traditional inverters of the same output quality. Methods. In this paper, sinusoidal pulse width modulation technique is used for the working of the switches in the multilevel inverter. The results are verified by using simulation and also experimental setup is done. From the results it is observed that the proposed topology with reduced number of switches gives lower electromagnetic interference, lower harmonic distortion. Practical value. The total harmonic distortion value in the simulation is 14.4 % and practically it is 13.8 %.Вступ. У світі технічного прогресу звичайні ресурси перебувають у стадії руйнації. Щоб уникнути таких проблем, ми збираємося використати альтернативне джерело енергії, а саме сонячну енергію з фотоелектричним ефектом. Попит на багаторівневі інвертори збільшився, оскільки вони використовуються для різних динамічних (високих) напруг та динамічних (високих) потужностей, оскільки вони здатні формувати вихідну форму хвилі з низьким гармонічним загальним спотворенням. Новизна. Новий багаторівневий інвертор використовується для додавання двостороннього перемикача між конденсатором і традиційним модулем Н-моста. Це дає найкращу синусоїду. При послідовному з’єднанні двох модулів Н-моста можливо дев’ять рівнів вихідної напруги, включаючи нуль. Метою запропонованої топології є зменшення кількості перемикачів, що дає хороший результат при порівняно менших втратах потужності порівняно з іншими традиційними звичайними інверторами з такою ж вихідною якістю. Методи. У цій статті для роботи перемикачів у багаторівневому інверторі використовується метод широтно-імпульсної синусоїдальної модуляції. Результати перевіряються за допомогою моделювання, а також виконується експеримент. З результатів видно, що пропонована топологія зі зменшеною кількістю перемикачів дає менші електромагнітні перешкоди, менші гармонійні спотворення. Практична цінність. Сумарне значення гармонійних спотворень при моделюванні складає 14,4 %, а практично – 13,8 %
Significance analysis of microarray for relative quantitation of LC/MS data in proteomics
<p>Abstract</p> <p>Background</p> <p>Although fold change is a commonly used criterion in quantitative proteomics for differentiating regulated proteins, it does not provide an estimation of false positive and false negative rates that is often desirable in a large-scale quantitative proteomic analysis. We explore the possibility of applying the Significance Analysis of Microarray (SAM) method (PNAS 98:5116-5121) to a differential proteomics problem of two samples with replicates. The quantitative proteomic analysis was carried out with nanoliquid chromatography/linear iron trap-Fourier transform mass spectrometry. The biological sample model included two <it>Mycobacterium smegmatis </it>unlabeled cell cultures grown at pH 5 and pH 7. The objective was to compare the protein relative abundance between the two unlabeled cell cultures, with an emphasis on significance analysis of protein differential expression using the SAM method. Results using the SAM method are compared with those obtained by fold change and the conventional <it>t</it>-test.</p> <p>Results</p> <p>We have applied the SAM method to solve the two-sample significance analysis problem in liquid chromatography/mass spectrometry (LC/MS) based quantitative proteomics. We grew the pH5 and pH7 unlabelled cell cultures in triplicate resulting in 6 biological replicates. Each biological replicate was mixed with a common <sup>15</sup>N-labeled reference culture cells for normalization prior to SDS/PAGE fractionation and LC/MS analysis. For each biological replicate, one center SDS/PAGE gel fraction was selected for triplicate LC/MS analysis. There were 121 proteins quantified in at least 5 of the 6 biological replicates. Of these 121 proteins, 106 were significant in differential expression by the <it>t</it>-test (<it>p </it>< 0.05) based on peptide-level replicates, 54 were significant in differential expression by SAM with Δ = 0.68 cutoff and false positive rate at 5%, and 29 were significant in differential expression by the <it>t</it>-test (<it>p </it>< 0.05) based on protein-level replicates. The results indicate that SAM appears to overcome the false positives one encounters using the peptide-based <it>t</it>-test while allowing for identification of a greater number of differentially expressed proteins than the protein-based <it>t</it>-test.</p> <p>Conclusion</p> <p>We demonstrate that the SAM method can be adapted for effective significance analysis of proteomic data. It provides much richer information about the protein differential expression profiles and is particularly useful in the estimation of false discovery rates and miss rates.</p
Towards an optimal therapy strategy for myogenous TMD, physiotherapy compared with occlusal splint therapy in an RCT with therapy-and-patient-specific treatment durations
Appendix. Threshold of signs and symptoms. Post-hoc power analysis on measures of effectiveness. Two-way ANOVA statistical analysis for pain intensity. Rules for progressing and ending splint therapy. Rules for progressing and ending physiotherapy. A stepped-care model including two possible therapies. (PDF 86 kb
Substrate specificity and role of PepN, a metallo-aminoendopeptidase from Escherichia coli
A case of subdural hematoma following lumbar puncture
Lumbar puncture (LP) is a frequent procedure done for administration of spinal anesthesia or for obtaining cerebrospinal fluid for analysis. The common complications of LP are pain at the local site and headache. Fortunately, the serious complications such as infections of central nervous system, brain stem herniation, and subdural hematoma are rare. We present a rare case of subdural hematoma following a LP
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