We report on the design, manufacturing and first characterisation of pad diodes, test structures and microstrip detectors processed with high resistivity magnetic Czochralski (MCz) p- and n-type Si. ...The pre-irradiation study on newly processed microstrip detectors and test structures show a good overall quality of the processed wafers. After irradiation with 24
GeV/
c protons up to 4×10
14
cm
-2 the characterisation of n-on-p and p-on-n MCz Si sensors with the
C–
V method show a decrease of the full depletion voltage and no space charge sign inversion. Microscopic characterisation has been performed to study the role of thermal donors in Czochralski Si. No evidence of thermal donor activation was observed in n-type MCz Si detectors if contact sintering was performed at a temperature lower than 380
°C and the final passivation oxide was omitted.
The luminosity upgrade of the CERN Large Hadron Collider (SLHC) imposes severe requirements on the radiation hardness of the tracking systems. The CERN RD50 collaboration as well as the Italian INFN ...SMART project (fifth commission) are focused on the study of new radiation hard materials and devices in view of this upgrade. Preliminary studies on irradiated high resistivity n- and p-type magnetic Czochralski silicon are described in this paper. Electrical characterization and microscopic defect studies were performed on a wide set of diodes made with both n- and p-type float zone and magnetic Czochralski silicon irradiated up to a nominal fluence of 3×10
15
cm
−2 1
MeV equivalent neutrons. The annealing behavior was studied in detail and a first evaluation of the damage-related parameters is shown.
Abstract
Objective
To analyse the effects of chronic oral anticoagulation on long–term outcomes after repair of type A acute aortic dissection and its influence on false lumen fate.
Methods
We ...studied 188 patients (median age 62 years; 74% males) who had repair of type A aortic dissection; patients receiving postoperative chronic oral anticoagulation (n = 59) were compared to those on antiplatelet therapy alone (n = 129).
Results
Median age was similar: 60 (18–79 years) vs 64 years (22–86) (p = 0.11); patients on anticoagulants were more frequently males (88% vs 67%, p = 0.003). After a median follow–up of 8.4 years (2 months to 30 years) 58 patients died, 18 for aortic–related causes, and 37 underwent aortic reintervention. After multivariable adjustment, anticoagulation showed no significant effect on long–term survival (HR 0.85, 95% CI 0.41–1.76; p = 0.66) neither on risk of reintervention (HR 0.55, 95% CI 0.27–1.15; p = 0.11). Analysis of 127 postoperative computed tomography scans showed a patent false lumen in 53% of anticoagulated vs 38% of not anticoagulated patients (p = 0.09); partially thrombosed in 8% vs 28% (p = 0.01) and thrombosed in 39% vs 34% (p = 0.63). In patients with a control computed tomography there were 6 late aortic–related deaths, 1 among patients anticoagulated and 5 in those who were not.
Conclusions
Chronic anticoagulation after repair of type A acute aortic dissection favours persistent late false lumen patency which is not a risk factor for late mortality or reoperation. Chronic anticoagulation can be administered safely to patients with repaired type A acute aortic dissection regardless of its specific indication.
In the present paper, the comparison of steady, simple pulsatile flow and physiological pulsatile flow on flow reversal zone and hemodynamic wall parameters wall shear stress (WSS) and oscillatory ...shear index (OSI) for the progression of the disease, atherosclerosis has been investigated numerically. The governing equations have been solved by finite volume method. For the numerical analysis, Womersley number, Reynolds number and percentage of restriction are taken as 10, 100 and 50 % respectively. From this study it is revealed that the separated flow from the stenosis strongly depends on inlet flow situations, the maximum chance of deposition of plaque material due to streamline contour is higher at time step t* = 0.75 for simple pulsatile flow and at time step t* = 0 for physiological pulsatile flow and this chance is lower in case of steady flow. The effect of WSS on the disease is higher in physiological pulsatile flow compared to steady as well as simple pulsatile flow. The maximum possibility of initiation as well as progression for atherosclerosis in arterial wall due to high WSS takes place at t* = 0.25 for physiological pulsatile flow. OSI indicates same length of separation for two cases of transient flow, but the rate of cyclic departure of WSS is higher in case of physiological pulsatile flow.
Till now pre-eclampsia is a disease of multiple theories. This case control study was carried out in the department of Obstetrics and Gynaecology of Bangabandhu Sheikh Mujib Medical University ...Hospital and Dhaka Medical College Hospital, from January 2006 to December 2007 to determine the association of maternal serum triglyceride with pre-eclampsia. Ninety pregnant women were studied, among them 45 patients were pre-eclamptic and served as case and 45 normal healthy pregnant women served as control. Estimation of serum triglyceride levels of all study patients was done with the help of enzymatic method. The mean (± SD) systolic blood pressure was 152.4 ± 19.8 mmHg in study group and 112.0 ± 8.9 mmHg in control group (p<0.05). Similarly the mean (± SD) diastolic blood pressure was 103.1 ± 12.2 mmHg in case group and 75.5 ± 6.6 mmHg in control group (p<0.05). Serum triglyceride level was more than the normal reference value in pre-eclamptic group. The mean (± SD) serum triglyceride level was 242.9 ± 36.8 mg/dl in case group and 184.6 ± 12.5mg/dl in control group. Statistically the difference was significant (p<0.05). The level of serum triglyceride positively correlated with the rise of blood pressure and degree of albuminuria. Thus serum triglyceride level increase in pre-eclampsia and the level correlate with the severity of the disease.
An interim report evaluating the feasibility of myeloablative therapy followed by peripheral blood stem cell (PBSC) autotransplant in patients aged >60 years is presented. In the last 2 years 19 ...patients >60 years old with several oncological conditions, mostly hematological, underwent PBSC autotransplant either as salvage therapy following relapse or resistance to conventional treatment, or as consolidating therapy as a part of a well defined protocol. There were 13 males and six females; the mean age was 66.9 years (range 61-76 years); nine patients had resistant or relapsed lymphoma, six myeloma, two acute leukemia, one Waldenstrom's disease and one lung cancer. Myeloablative schemes included BEAM exclusively for lymphomas, busulfan and melphalan (Bu-MPH) mainly for myeloma, busulfan and cyclophosphamide (Bu-CTX) for lymphomas and leukemia and VP-16 and CTX for lung cancer. Mobilization of CD34+ cells was achieved in all patients with the combination of high-dose CTX and G-CSF with collections between 2.83 to 19.04 x 10(6)/kg (mean 7.1). All patients engrafted with a median time for recovery of PMN (>0.5 x 10(3)/microl) of 10 days (range 8-12 days) and for PLT (>20 x 10(3)/microl) of 12 days (range 10-17 days). Major responses were obtained in 15 of 16 patients evaluable for response and eight patients entered CR; overall eight patients are in CR, five are alive with disease, five are dead from disease progression and one is dead because of congestive heart failure 7 months following PBSC autotransplant. No early deaths following the procedure occurred; major side-effects were grade I-II mucositis (58%), fever with documented sepsis (10%), pneumonia (5%), cardiac, renal and liver toxicity (5%). Cardiac function was evaluated before and after myeloablative therapy by VEF in all patients; no significant modifications were necessary. In conclusion, our experience demonstrates that myeloablative therapies in older selected patients can be feasible; the feasibility of introducing PBSC autotransplantation following myeloablative therapy as a front-line treatment in patients aged >60 years, needs accurate guide lines for selection of appropriate patients.
Wall shear stress (WSS) characteristics of a stenosed artery which are the important physiological parameters for the progression of the arterial diseases atherosclerosis, are studied and compared ...for different Reynolds numbers and different Womersley numbers. Numerical simulations of physiological pulsatile flow through a model stenotic artery are performed by finite volume method. From this study, it is revealed that the chance of formation of atherosclerosis increases with increase in Reynolds number and decreases with increase in Womersley number. The phenomenon of mass transportation across arterial wall is more in case of increase in Womersley number rather than Reynolds number. The chance of formation of atheromatous plaque will be high with higher Reynolds number and Womersley number. In the low WSS region, high magnitude of Womersley number indicates high chance of progression of the disease atherosclerosis. High magnitude of Womersley number with low Reynolds number is more dangerous for the progression of the disease in the low WSS region.
Flow cytometry crossmatch (FCXM) is used to assess pre-transplant immunologic risk. Each laboratory must establish FCXM positive thresholds but the method to do so is not standardized. Many factors ...affect FCXM and its interpretation. Our aim was to compare methods of calculating FCXM thresholds and evaluate the impact of cell source and pronase.
Threshold study (TS) data were collected by FCXM with healthy control sera negative for HLA antibodies (n = 24) vs pronased, negatively selected T & B cells from either peripheral blood (PBL), fresh or frozen spleen (n = 264, 215, and 96, respectively). Non-pronased FCXM were tested in parallel (n = 72). Data normality tests were performed on this and previous TS data. Outlier values were assessed by 1.5 interquartile range (IQR) and standard deviation (SD). Thresholds were calculated by mean or median + varying SD as well as 97.5th percentile. Thresholds were assessed in expected positive FCXM (PBL & spleen) with/without pronase.
Median channel values (MCV) were not normally distributed in either TS dataset (Fig. 1). Thresholds vary by cell source: fresh spleen < PBL < frozen spleen. The best test for removing outliers was 1.5IQR: low numbers of FCXM with high MCVs excluded. Non-pronased T cell thresholds were higher than in pronased cells; T cell FCXM was more sensitive with pronased cells. T cells were better able to detect low levels of class I antibody in PBL FCXM but sensitivity is similar between T & B cells from spleen.
Non-parametric means of assessing FCXM thresholds may be required. Cell source affects FXCM sensitivity for class I antibodies, perhaps due to number of T vs B cells. We have previously shown that pronase increases class I detection on T cells; these FCXM data support this finding; preliminary thresholds calculated from non-pronased cells do not correct this reduced sensitivity. A thorough understanding of factors that affect FCXM will optimize determination of relevant thresholds and assist in the interpretation of this commonly used assay.▪
Purpose This paper aims to perform numerical simulations through different shaped double stenoses in a vascular tube for a better understanding of arterial blood flow patterns, and their possible ...role during the progression of atherosclerosis. The dynamics of flow features have been studied by wall pressure, streamline contour and wall shear stress distributions for all models. Designmethodologyapproach A finite volume method has been employed to solve the governing equations for the twodimensional, steady, laminar flow of an incompressible and Newtonian fluid. Findings The paper finds that impact of pressure drop, reattachment length and peak wall shear stress at each restriction primarily depends upon percentage of restriction, if restriction spacing is sufficient. The quantum of impact of pressure drop, reattachment length and peak wall shear stress is much effected for smaller restriction spacing. If recirculating bubble of first restriction merges with the recirculating bubble formed behind the second restriction in this smaller restriction spacing. The similar effect of smaller restriction spacing is observed, if Reynolds number increases also. Originalityvalue The effect of different shaped stenoses, restriction spacing and Reynolds number on the flow characteristics has been investigated and the role of all the flow characteristics on the progression of the disease, atherosclerosis, is discussed.
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