297 research outputs found
Seismicity, earthquake mechanisms, and seismic wave attenuation in the northeastern United States
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1983.Microfiche copy available in Archives and ScienceVita.Bibliography: leaves 276-289.by Jay J. Pulli.Ph.D
Preliminary studies on the conservation of whole sorghum and corn plant and sugar corn stover for silage
The whole corn plant and sugar corn stover were ensiled in stacks covered with plastics and soil. Sorghum was ensiled in tower silo. The amounts of fodder ensiled were 2 500 kg, 3 100 kg and 1400 kg, respectively. All silages were chopped with a precision chopper and ensiled without preservatives. The feeding values of the silages were determined with sheep according to 2 X 3 X 3 Latin square design. Urea (0.3 % of the fresh weight) was added to the silages before feeding. An intense secondary fermentation was found in all silages. The possible causes for this were the soil contamination of the fodder during harvesting and the effluent remained in the stack silages. The secondary fermentation decreased the sugar content of the silages and increased the fermentation losses especially in the corn silage. However, the quality of the silages was fairly good. Urea decreased the palatability of the silages and it would be better to add the urea to the silages before the ensiling. The energy and DCP values of the silages were quite modest. There were 0.63, 0.72 and 0.69 f.u./kg silage DM in sorghum, corn and corn stover silages, respectively The corresponding values for DCP were 75, 62 and 86 g/kg silage DM (urea included)
Maize for silage II. The effect of urea and acid as preservative treament on rumen fermentations and on feeding values of silages
The rumen fermentations and N-balances of rumen fistulated sheep were studied on diets of silages treated with urea and acid preservative. The digestibilities and feeding values of the silages were also calculated. The experiment was performed according to 5 x 5 Latin-square design. The digestibilities were determined by total collection the collection period lasting seven days. The rumen samples were taken on the last two days during the collection periods before and 1.5, 3.0, 4.5 and 6.0 hours after feeding. Besides the silages the animals received mineral mixture and water ad libitum. Urea or acid treatment had no effect (P > 0.05) on the consumption of silage DM. The consumption ranged from 1.7 to 1.9 kg DM/100 kg liveweight. Urea did not have a clear effect on the VFA production in the rumen. It tended, however, to decrease the proportions of C3 and C4âC5 acids in the rumen. Acid preservative decreased the production of VFA and the proportion of C3-acid (P 0.05) were found between the energy values, which varied between 0,12â0.14 f.u./kg of silage. There were no differences in the N-balances of the animals on different diets. The balances were positive on all diets
Alternative hybrid reconstruction for bilateral common and internal iliac artery aneurysms associated with external iliac artery occlusion
Purpose: To describe an alternative reconstruction for bilateral common (CIA) and internal
(IIA) iliac artery aneurysms associated with external iliac artery (EIA) occlusion in a patient
unfit for open surgery.
Case Report: A high-risk 81-year-old man presented with contained rupture of a left CIA
aneurysm in the presence of bilateral CIA and IIA aneurysms associated with complete
occlusion of the left EIA and normal patency of both common femoral arteries. In an
emergent procedure, the left EIA was recanalized subintimally, and the right IIA was
embolized with a 14-mm Amplatzer Plug. The main body of a standard Excluder endograft
was deployed just distal to the origin of the left renal artery, and the ipsilateral leg was
extended into the proximal right EIA. On the contralateral side, a short 10-mm-diameter
limb was inserted through a 12-F sheath and deployed in the CIA, proximal to the iliac
bifurcation. Via a percutaneous left brachial artery access, 3 covered stents (9359 mm,
10359 mm, 10359 mm) were deployed from the distal IIA to the endograft contralateral
limb. A right-to-left femorofemoral crossover bypass graft concluded the operation. The
patient was discharged on the 5th postoperative day without complications; follow-up
imaging at 6 months showed patency of the stent-graft and crossover bypass, with
complete exclusion of the aneurysms and no evidence of endoleak.
Conclusion: This case demonstrates an effective solution for complex aortoiliac lesions
using commercially available devices, underlining how an accurate knowledge of
alternative endovascular techniques and materials is crucial in the management of
complex cases
Random Expert Sampling for Deep Learning Segmentation of Acute Ischemic Stroke on Non-contrast CT
Purpose: Multi-expert deep learning training methods to automatically
quantify ischemic brain tissue on Non-Contrast CT Materials and Methods: The
data set consisted of 260 Non-Contrast CTs from 233 patients of acute ischemic
stroke patients recruited in the DEFUSE 3 trial. A benchmark U-Net was trained
on the reference annotations of three experienced neuroradiologists to segment
ischemic brain tissue using majority vote and random expert sampling training
schemes. We used a one-sided Wilcoxon signed-rank test on a set of segmentation
metrics to compare bootstrapped point estimates of the training schemes with
the inter-expert agreement and ratio of variance for consistency analysis. We
further compare volumes with the 24h-follow-up DWI (final infarct core) in the
patient subgroup with full reperfusion and we test volumes for correlation to
the clinical outcome (mRS after 30 and 90 days) with the Spearman method.
Results: Random expert sampling leads to a model that shows better agreement
with experts than experts agree among themselves and better agreement than the
agreement between experts and a majority-vote model performance (Surface Dice
at Tolerance 5mm improvement of 61% to 0.70 +- 0.03 and Dice improvement of 25%
to 0.50 +- 0.04). The model-based predicted volume similarly estimated the
final infarct volume and correlated better to the clinical outcome than CT
perfusion. Conclusion: A model trained on random expert sampling can identify
the presence and location of acute ischemic brain tissue on Non-Contrast CT
similar to CT perfusion and with better consistency than experts. This may
further secure the selection of patients eligible for endovascular treatment in
less specialized hospitals
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Measuring Myeloperoxidase Activity in Biological Samples
Background: Enzymatic activity measurements of the highly oxidative enzyme myeloperoxidase (MPO), which is implicated in many diseases, are widely used in the literature, but often suffer from nonspecificity and lack of uniformity. Thus, validation and standardization are needed to establish a robust method that is highly specific, sensitive, and reproducible for assaying MPO activity in biological samples. Principal findings We found conflicting results between in vivo molecular MR imaging of MPO, which measures extracellular activity, and commonly used in vitro MPO activity assays. Thus, we established and validated a protocol to obtain extra- and intracellular MPO from murine organs. To validate the MPO activity assays, three different classes of MPO activity assays were used in spike and recovery experiments. However, these assay methods yielded inconsistent results, likely because of interfering substances and other peroxidases present in tissue extracts. To circumvent this, we first captured MPO with an antibody. The MPO activity of the resultant samples was assessed by ADHP and validated against samples from MPO-knockout mice in murine disease models of multiple sclerosis, steatohepatitis, and myocardial infarction. We found the measurements performed using this protocol to be highly specific and reproducible, and when performed using ADHP, to be highly sensitive over a broad range. In addition, we found that intracellular MPO activity correlated well with tissue neutrophil content, and can be used as a marker to assess neutrophil infiltration in the tissue. Conclusion: We validated a highly specific and sensitive assay protocol that should be used as the standard method for all MPO activity assays in biological samples. We also established a method to obtain extra- and intracellular MPO from murine organs. Extracellular MPO activity gives an estimate of the oxidative stress in inflammatory diseases, while intracellular MPO activity correlates well with tissue neutrophil content. A detailed step-by-step protocol is provided
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Loss of CD147 results in impaired epithelial cell differentiation and malformation of the meibomian gland
Meibomian gland dysfunction is a leading cause of ocular surface disease. However, little is known about the regulatory processes that control the development and maintenance of this sebaceous gland. Here, we identify a novel function for CD147, a transmembrane protein that promotes tissue remodeling through induction of matrix metalloproteinases, in regulating meibocyte differentiation and activity. We found that CD147 localized along basal cells and within discrete membrane domains of differentiated meibocytes in glandular acini containing gelatinolytic activity. Induction of meibocyte differentiation in vitro promoted CD147 clustering and MMP9 secretion, whereas RNAi-mediated abrogation of CD147 impaired MMP9 secretion, concomitant with a reduction in the number of proliferative cells and cytoplasmic lipids. Meibomian glands of CD147 knockout mice had a lower number of acini in both the superior and inferior tarsal plates of the eyelids, and were characterized by loss of lipid-filled meibocytes compared with control mice. Together, our data provide evidence showing that gelatinolytic activity in meibocytes is dependent on CD147, and supports a role for CD147 in maintaining the normal development and function of the meibomian gland
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Loss of CD147 results in impaired epithelial cell differentiation and malformation of the meibomian gland
Meibomian gland dysfunction is a leading cause of ocular surface disease. However, little is known about the regulatory processes that control the development and maintenance of this sebaceous gland. Here, we identify a novel function for CD147, a transmembrane protein that promotes tissue remodeling through induction of matrix metalloproteinases, in regulating meibocyte differentiation and activity. We found that CD147 localized along basal cells and within discrete membrane domains of differentiated meibocytes in glandular acini containing gelatinolytic activity. Induction of meibocyte differentiation in vitro promoted CD147 clustering and MMP9 secretion, whereas RNAi-mediated abrogation of CD147 impaired MMP9 secretion, concomitant with a reduction in the number of proliferative cells and cytoplasmic lipids. Meibomian glands of CD147 knockout mice had a lower number of acini in both the superior and inferior tarsal plates of the eyelids, and were characterized by loss of lipid-filled meibocytes compared with control mice. Together, our data provide evidence showing that gelatinolytic activity in meibocytes is dependent on CD147, and supports a role for CD147 in maintaining the normal development and function of the meibomian gland
SUrgical versus PERcutaneous Bypass: SUPERB-trial; Heparin-bonded endoluminal versus surgical femoro-popliteal bypass: study protocol for a randomized controlled trial
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96315.pdf (publisher's version ) (Open Access)BACKGROUND: Endovascular treatment options for the superficial femoral artery are evolving rapidly. For long lesions, the venous femoropopliteal bypass considered to be superior above the prosthetic bypass. An endoluminal bypass, however, may provide equal patency rates compared to the prosthetic above knee bypass. The introduction of heparin-bonded endografts may further improve patency rates. The SUrgical versus PERcutaneous Bypass (SuperB) study is designed to assess whether a heparin-bonded endoluminal bypass provides equal patency rates compared to the venous bypass and to prove that it is associated with improved quality of life, related to a decreased complication rate, or not. METHODS/DESIGN: Two-hundred-twenty-two patients with peripheral arterial occlusive disease, category 3-6 according to Rutherford, will be randomized in two treatment arms; 1. the surgical femoro-popliteal bypass, venous whenever possible, and 2. the heparin-bonded endoluminal bypass. The power analysis was based on a non-inferiority principle, with an effect size of 90% and 10% margins (alpha 5%, power 80%). Patients will be recruited from 5 teaching hospitals in the Netherlands during a 2-year period. The primary endpoint is primary patency and quality of life evaluated by the RAND-36 questionnaire and the Walking Impairment Questionnaire. Secondary endpoints include secondary patency, freedom-from-TLR and complications. DISCUSSION: The SuperB trial is a multicentre randomized controlled trial designed to show non-inferiority in patency rates of the heparin-bonded endograft compared to the surgical bypass for treatment of long SFA lesions, and to prove a better quality of life using the heparin bonded-endograft compared to surgically treatment, related to a reduction in complications. TRIAL REGISTRATION: Clinicaltrials: NCT01220245
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