717 research outputs found
Effective Treatment of Severe Hypertension
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72801/1/j.1751-7117.1999.tb00186.x.pd
A rigorous analysis of high order electromagnetic invisibility cloaks
There is currently a great deal of interest in the invisibility cloaks
recently proposed by Pendry et al. that are based in the transformation
approach. They obtained their results using first order transformations. In
recent papers Hendi et al. and Cai et al. considered invisibility cloaks with
high order transformations. In this paper we study high order electromagnetic
invisibility cloaks in transformation media obtained by high order
transformations from general anisotropic media. We consider the case where
there is a finite number of spherical cloaks located in different points in
space. We prove that for any incident plane wave, at any frequency, the
scattered wave is identically zero. We also consider the scattering of finite
energy wave packets. We prove that the scattering matrix is the identity, i.e.,
that for any incoming wave packet the outgoing wave packet is the same as the
incoming one. This proves that the invisibility cloaks can not be detected in
any scattering experiment with electromagnetic waves in high order
transformation media, and in particular in the first order transformation media
of Pendry et al. We also prove that the high order invisibility cloaks, as well
as the first order ones, cloak passive and active devices. The cloaked objects
completely decouple from the exterior. Actually, the cloaking outside is
independent of what is inside the cloaked objects. The electromagnetic waves
inside the cloaked objects can not leave the concealed regions and viceversa,
the electromagnetic waves outside the cloaked objects can not go inside the
concealed regions. As we prove our results for media that are obtained by
transformation from general anisotropic materials, we prove that it is possible
to cloak objects inside general crystals.Comment: The final version is now published in Journal of Physics A:
Mathematical and Theoretical, vol 41 (2008) 065207 (21 pp). Included in
IOP-Selec
“Environmental Hypertensionology” The Effects of Environmental Factors on Blood Pressure in Clinical Practice and Research
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/88111/1/j.1751-7176.2011.00543.x.pd
Thoracoscopic treatment of pulmonary sequestration
Objective: Pulmonary sequestration is a rare congenital malformation and may be the cause of recurrent infections or hemoptysis. It has been shown in case reports that resection by video-assisted thoracic surgery (VATS) is feasible despite the possible technical difficulties due to inflammatory changes, but its role has not been evaluated yet in a larger series of consecutively treated patients. Methods: Retrospective analysis of all consecutively thoracoscopically treated patients (between January 1991 and January 2005) with pulmonary sequestration in a single center. We included 14 patients in the study who fulfilled the criteria; seven were women. Median age was 33 years (20-64 years). The following data were analyzed for all patients: major symptoms, diagnostic procedures, treatment, and outcome. Operative parameters and findings including operating time, blood loss, anatomical location of the sequestration, and feeding vessels were evaluated. Results: Leading symptoms were recurrent infections (10), hemoptysis (3), and chest discomfort (1). The diagnosis was made by CT scan. Additionally, an arteriography or an angio-MRI was done in three patients and one patient, respectively. Thirteen intralobar (all lower lobes, eight on the right) and one left-sided extralobar pulmonary sequestration were resected. We performed eight lobectomies, four atypical segmentectomies, one extralobar resection, and one occlusion of the aberrant artery. One case had to be converted to a thoracotomy due to bleeding from the aberrant artery. There was no mortality. Complications included pneumonia in three cases, one hemothorax, one pneumothorax after removing the chest tube, and one wound infection. All were treated conservatively. Conclusion: Thoracoscopic treatment of pulmonary sequestration is feasible in experienced hands. The aberrant systemic artery can be freed and dissected safely despite the frequently occurring inflammatory changes. Conversion rate to thoracotomy is lo
Inverse Scattering at a Fixed Quasi-Energy for Potentials Periodic in Time
We prove that the scattering matrix at a fixed quasi--energy determines
uniquely a time--periodic potential that decays exponentially at infinity. We
consider potentials that for each fixed time belong to in space. The
exponent 3/2 is critical for the singularities of the potential in space. For
this singular class of potentials the result is new even in the
time--independent case, where it was only known for bounded exponentially
decreasing potentials.Comment: In this revised version I give a more detailed motivation of the
class of potentials that I consider and I have corrected some typo
Small-Energy Analysis for the Selfadjoint Matrix Schroedinger Operator on the Half Line
The matrix Schroedinger equation with a selfadjoint matrix potential is
considered on the half line with the most general selfadjoint boundary
condition at the origin. When the matrix potential is integrable and has a
first moment, it is shown that the corresponding scattering matrix is
continuous at zero energy. An explicit formula is provided for the scattering
matrix at zero energy. The small-energy asymptotics are established also for
the corresponding Jost matrix, its inverse, and various other quantities
relevant to the corresponding direct and inverse scattering problems.Comment: This published version has been edited to improve the presentation of
the result
Associations between fruit and vegetable intake and quality of life
Abstract Dysregulation of the immune response to microbiota is associated with inflammatory bowel disease (IBD), which can trigger intestinal fibrosis. MyD88 is a key component of microbiota signalling but its influence on intestinal fibrosis has not been clarified. Small bowel resections from donor-mice were transplanted subcutaneously into the neck of recipients C57BL/6 B6-MyD88tm1 Aki (MyD88−/−) and C57BL/6-Tg(UBC-green fluorescence protein (GFP))30Scha/J (GFP-Tg). Grafts were explanted up to 21 days after transplantation. Collagen layer thickness was determined using Sirius Red stained slides. In the mouse model of fibrosis collagen deposition and transforming growth factor-beta 1 (TGF-β1) expression was equal in MyD88+/+ and MyD88−/−, indicating that MyD88 was not essential for fibrogenesis. Matrix metalloproteinase (Mmp)9 expression was significantly decreased in grafts transplanted into MyD88−/− recipients compared to MyD88+/+ recipients (0.2 ± 0.1 vs. 153.0 ± 23.1, respectively, p < 0.05), similarly recruitment of neutrophils was significantly reduced (16.3 ± 4.5 vs. 25.4 ± 3.1, respectively, p < 0.05). Development of intestinal fibrosis appears to be independent of MyD88 signalling indicating a minor role of bacterial wall compounds in the process which is in contrast to published concepts and theories. Development of fibrosis appears to be uncoupled from acute inflammation
Prognostic significance of epithelial-mesenchymal transition in malignant pleural mesothelioma
Background: Epithelial-to-mesenchymal transition (EMT) is a morphologic transdifferentiation of carcinomas, conferring increased tumour invasiveness, but may also be applied to the epithelioid versus sarcomatoid histotype of malignant pleural mesothelioma (MPM). Herein, we correlated proteins of a putative MPM-EMT axis, including periostin, epidermal growth factor receptor (EGFR), integrin beta1, phosphatase and tensin homologue (PTEN), integrin-linked kinase (ILK), p21 and p27, with clinico-pathologic parameters, in particular overall survival (OS). Patients and Methods: A retrospective cohort of 352 mostly untreated patients with MPM was investigated by immunohistochemistry of a tissue microarray. Protein expression intensities were semi-quantitatively scored from 0 to 3 in their respective compartments, including peritumoural stroma as well as tumour cell plasma membrane, cytoplasm or nucleus. Data were correlated with histotype and survival outcome. Results: A total of 32% of the tumours were diagnosed as epithelioid, 13% as sarcomatoid and 55% as biphasic histotype. High expression of membranous EGFR and integrin beta1 as well as nuclear p27 correlated with the epithelioid and high expression of cytoplasmic tumoural and stromal periostin with the sarcomatoid histotype. The median survival time of the 128 patients with complete follow-up data was 11.7 months. Univariate survival analysis revealed age, epithelioid histotype and any therapy as prognosticators for better OS. High expression of cytoplasmic PTEN or ILK as well as high expression of nuclear p21 or p27 correlated with increased, whereas high expression of cytoplasmic periostin with decreased OS (all p values <0.05). Multivariate Cox regression revealed any treatment, low cytoplasmic periostin and high cytoplasmic PTEN as independent prognosticators for better OS. Conclusion: Activation of periostin-triggered EMT is associated with the sarcomatoid histotype and has an impact on shorter survival of MPM patients. Finally, only the high expression of PTEN and the low expression of cytosolic periostin could be shown to be independent prognostic factors for longer O
The postpneumonectomy syndrome: clinical presentation and treatment
Background: Postpneumonectomy syndrome (PPS) is a rare complication after pneumonectomy. It consists of an excessive mediastinal shift resulting in compression and stretching of the tracheobronchial tree and the esophagus. The aim of this study was to give a comprehensive overview of diagnosis, variety of symptoms and evaluation of surgical treatment of PPS. Methods: We retrospectively reviewed the charts of all our patients with PPS since 1994 with respect to symptomatology, treatment and outcome. Our results were compared with case reports and case series in the literature. Results: Six women with a median age of 56.5 years (range 49-65) developed PPS after pneumonectomy for the treatment of lung cancer. Four presented with a right PPS and two with a left PPS, respectively. Symptoms consisted of shortness of breath in all patients and dysphagia as well as heartburn in two patients. Correction of PPS required re-exploration of the pneumonectomy space, reposition of the mediastinum followed by the insertion of single silicone prosthesis in five patients or fixation of the mediastinum with a xenopericardial graft in one patient. We could observe an improvement of the FEV(1)/FVC ratio in all our patients and the clinical improvement of shortness of breath was better than we expected by changes of lung function. Four patients returned to their regular activities with a follow-up of four years. We found 73 cases of PPS in the literature, on the right side in 50 patients (68%) and on the left side in 23 patients (32%). Fifty-nine patients (81%) were treated surgically. Symptoms can be suspicious for cardiogenic origin and vary from heartburn to recurrent syncopes. Conclusion: PPS is rare and not predictable. It can occur after right or left pneumonectomy. Symptoms are manifold and result from a shift, leading to compression and stretching of the two conduits located within the mediastinum, the tracheobronchial tree and the esophagus and consists of shortness of breath, stridor and heartburn. Diagnosis must be made by exclusion. Implantation of prosthesis is the most commonly used and effective treatmen
Contemporary antihypertensive therapy
Pharmacotherapy of human hypertension is effective, safe and well-tolerated. Antihypertensive drugs are of three broad classes: diuretics, sympatholytics and vasodilators. The use of each class is discussed and a summary of therapeutic considerations offered for representative agents. Recent trends in antihypertensive therapy are identified.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26517/1/0000055.pd
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