Medical ultrasound imaging using pulse compression

Pulse compression techniques can play a major role in improving image quality in medical ultrasound. A prototype imaging and digital signal processing system incorporating this technique is described. Feasibility studies were performed and system resolution was evaluated with experiments on tissue mimicking phantoms.<>     

The clinical relevance of circulating tumor necrosis factor-alpha in acute decompensated chronic heart failure without cachexia

STUDY OBJECTIVE: To evaluate the clinical relevance of circulating tumor necrosis factor-alpha (TNF alpha) in subjects with advanced acutely decompensated congestive heart failure (CHF) and to determine the modulatory effect of clinical interventions on short-term elaboration of this cytokine. DESIGN: Prospective, case-controlled study. SETTING: Inpatient and outpatient (hospital and clinic), at regional academic medical center. PATIENT INTERVENTIONS: Plasma concentrations of TNF alpha were determined in 25 healthy, normal control subjects and in 29 noncachectic patients with advanced CHF (mean ejection fraction = 16 +/- 6%) who required hospitalization for i.v. diuretic and/or inotropic therapy despite optimization of oral medical regimens. CHF patients were divided into two groups: diuretic responsive (group A; n = 6) and diuretic resistant requiring inotropic support (group B; n = 23). Group B was randomly allocated to receive either i.v. dobutamine (n = 13) or milrinone (n = 10) for 72 h. TNF alpha levels in CHF patients were measured serially at baseline, at 6 h, at 48 h, at 72 h, and at 1-week follow-up after hospital discharge. RESULTS: Plasma TNF alpha levels at baseline in CHF patients were 4.0 +/- 1.1 pg/mL (range, 0.5 to 6.5 pg/ mL) and 2.5 +/- 0.6 pg/mL (range, 0.5 to 6.8 pg/mL) in groups A and B, respectively, which were significantly different (p < 0.002) from normal subjects (0.89 +/- 0.40 pg/mL; range, 0.5 to 9.7 pg/mL). Despite clinically successful therapy with i.v. diuretics, dobutamine, or milrinone, plasma levels of this cytokine remained unchanged. Plasma TNF alpha in CHF patients measured in recovery (1 week after hospital discharge) was 5.1 +/- 1.2 pg/mL (range, 1.0 to 9.9 pg/mL) and 3.9 +/- 0.8 pg/mL (range, 0.5 to 8.7 pg/mL) in groups A and B, respectively. CONCLUSION: These findings suggest that although noncachectic patients with chronic heart failure who suffer acute decompensation elaborate significantly higher circulating levels of TNF alpha compared with healthy control subjects, no significant reduction or alteration in circulating TNF alpha is noted in the short-term follow-up despite clinical improvement.     

Analysis of copper-induced metallothionein expression using autonomously replicating plasmids in Candida glabrata

Candida glabrata strains and a stable plasmid were developed that were suitable for analysis of copper-inducible expression from promoters of the three metallothionein (MT) genes. The two homologous MTII genes, MTIIa and MTIIb, encode the same polypeptide but are differentially induced by copper salts. MTIIb is more highly inducible than MTIIa and cells harboring a single MTIIb exhibit a greater resistance to copper salts compared to cells harboring a single MTIIa. The differential copper inducibility was mapped to sequences between ? 503 and ? 292 upstream of the MT coding sequences. Expression of MTI is highly Cu-regulated, but this MT gene confers much less resistance than MTII genes.     

Leaching and bioavailability of aluminium, copper and manganese from tea (Camellia sinensis)

To assess human exposure to Al, Cu and Mn from tea drinking, eight tea samples were analysed for their ‘total’ and soluble elemental content. From this data, the percentage of ‘available’ element to the human system was calculated. Results for the samples showed that, compared to background levels for plants, concentrations of Al were highly elevated. The solubility of Al, Cu and Mn in infusions at 2, 5 and 10 min with boiling water showed that the solubility in the first infusion was the highest followed by the second and the third infusions in decreasing order. Calculation of percentage ‘available’ Al, Cu and Mn to the human system showed that tea is a rich source of dietary Mn, contributes towards our dietary copper intake, and is of no cause for concern in terms of Al toxicity in healthy individuals.     

Cast iron deterioration with time in various aqueous salt solutions

The changes with time in the corrosion rate and corrosion current density on a cast iron electrode in various aqueous salt solutions have been carried out using total immersion test and potentiostatic polarization curves. The concentration of salts taken is expected to be present in potable water. The relative behaviour of these salts towards corrosion has also been studied, which is found to be different from previous studies. The total immersion test parameters viz. weight loss, corrosion rate as well as potentiostatic parameters, open circuit potential,I _corr, Tafel slopes, corrosion rate, have been calculated by standard methods. Besides these the relative increase in corrosion rate with time as well as the percentage to which corrosion rate should be decreased so as to provide protection towards corrosion have also been calculated. It was found that KCl and NaCl are major contributors than MnSO₄, Pb(NO₃)₂, KI and KBr. The relative increase in corrosion is high in KBr, KI, NaNO₃, CaCl₂, and less in Pb(NO₃)₂, NaHCO₃ and CaCO₃ test solutions. For the reliability of results the data has been statistically analysed.     

HLA association and occurrence of autoantibodies in Asian-Indian patients with ulcerative colitis

OBJECTIVES: The purpose of the present study was to determine the profile of HLA class I antigens, antinuclear antibodies (ANA), and antineutrophil cytoplasmic antibodies (ANCA) in ulcerative colitis (UC) patients from Northern India. METHODS: The study consisted of 100 UC patients with or without extraintestinal manifestations. Data on HLA, ANA, and ANCA were analyzed with respect to age at onset, sex, duration of disease, and occurrence of extraintestinal manifestations, and data were correlated with those of healthy controls from the same population. RESULTS: The most common extraintestinal manifestations in order of occurrence were arthralgia (53.8%), ocular lesions (18%), sacroiliitis (12.7%), hepatobiliary (7.7%), cutaneous (5%), and vascular (2.6%). ANA and ANCA were positive in only 3% of cases. Of the HLA class I antigens, HLA-A19 was significantly increased in UC patients compared with controls (63.4% vs. 33.5%, p < 0.001, RR = 3.4), particularly its subtype HLA-A33 (20.7% vs. 4%, p < 0.001, RR = 6.3). There was no deviation in the frequency of HLA-B locus antigens, whereas HLA-Cw6 was increased significantly in patients compared with controls (14.6% vs. 3.5%, p < 0.001, RR = 4.4). CONCLUSIONS: The occurrence of extraintestinal manifestations in Indian patients with UC is similar to that reported elsewhere, although ANA and ANCA positivity is lower. HLA studies revealed that A19(33) and Cw6 are associated with UC.     

Computing a Pareto-optimal solution for multi-objective flexible linear programming in a bipolar framework

In this paper, we study the multi-objective flexible linear programming (MOFLP) problems (or fuzzy multi-objective linear programming problems) in the heterogeneous bipolar framework. Bipolarity allows us to distinguish between the negative and the positive preferences. Negative preferences denote what is unacceptable while positive preferences are less restrictive and express what is desirable. This viewpoint enables us to handle fuzzy sets representing constraints and objective functions separately and combine them in distinct ways. In this paper, a solution concept of Pareto-optimality for MOFLP problems is defined and an approach is proposed to single out such a solution for MOFLP with highest possible degree of feasibility.     

Enhanced indexing for risk averse investors using relaxed second order stochastic dominance

The less efficient markets offer scope for enhanced indexing (EI), an investment strategy of portfolio selection which seeks to earn more return than the benchmark index. In this context, we examine the use of relaxed second order stochastic dominance (RSSD) by introducing underachievement and overachievement variables in the second order stochastic dominance (SSD), for EI. We propose a linear optimization model that maximizes the mean return subject to the constraints formed using RSSD. We impose bounds on the ratio of the total underachievement to the sum of total underachievement and total overachievement variables depicting the risk-return tradeoff in the model. The proposed model for EI is inspired from many applications of SSD and almost SSD (ASSD). We examine the performance of the proposed model with the SSD model, EI model of maximizing mean return and minimizing the underperformance (MM) from the benchmark index, \(\epsilon \)-almost second order stochastic dominance (\(\epsilon \)-ASSD) model, and the naïve 1/N portfolio, on two Indian stock indices, CNX 100 and CNX 200, through a rolling window strategy. To widen the empirical analysis, we also compare all models on the eight publicly available real financial data sets from Beasley OR library through a single window strategy. The portfolios from the proposed model are shown to produce statistically significant mean excess return and excess Sharpe ratio (both from the benchmark indices) more often than the MM and \(\epsilon \)-ASSD models. Also, the portfolios from the proposed model always have smaller violation area in SSD constraints from benchmark indices than the MM and \(\epsilon \)-ASSD models.