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In response to the potential hazards associated with the globalization of the food industry, research has been focused on the development of new sensing techniques to provide the means of contamination detection at any stage in the food supply chain. The demand for on-site detection is growing as pre-emptive sensing of pathogens could eliminate foodborne-related outbreaks and associated healthcare costs. Reduction in food waste is also a driver for point-of-use (POU) sensing, from both an economic and environmental standpoint. The following review discusses the latest advancements in platforms that have the greatest potential for inexpensive, real-time detection, and identification of foodborne pathogens. Specific focus has been placed on the development techniques, which utilize micro- and nanoscale technology. Sample preparation-free techniques are also discussed, as the growing demand to enable POU sensing at any stage in the food supply chain will be a major driver toward the advancements of these nondestructive methods.

This study analyzes the initial experience with minimally invasive mitral valve surgery through a right minithoracotomy in a public teaching hospital in Australia and evaluates early surgical outcomes.A retrospective review of patients who underwent minimally invasive mitral valve surgery between November 2006 and March 2009 was performed.A total of 60 patients included 47 (78%) patients who had mitral valve plasty and 13 (22%) who had mitral valve replacement. The mean age was 61 ± 15 years; 33 (55%) patients were male; and 6 (10%) had had previous cardiac operations. The mean cardiopulmonary bypass and aortic cross-clamp times were 140 ± 46 and 93 ± 35 min, respectively. All patients who underwent mitral valve plasty left the operation room with no more than trivial residual mitral regurgitation. There was no operative mortality. Reoperation for bleeding and stroke occurred in 2 patients each. The mean intensive care unit and hospital stays were 3.1 ± 5.8 and 10.6 ± 8.9 days, respectively. Among the 47 patients with mitral valve plasty, 46 (98%) had mild or less mitral regurgitation on transthoracic echocardiography at discharge. There was one late death. No reoperation for the mitral valve has been observed so far. An echocardiography report was obtained for 34 of the 47 who had had mitral valve plasty at 12.1 ± 7.9 months postoperatively, and 27 (79%) of them had mild or less mitral regurgitation.Minimally invasive mitral valve surgery through a right minithoracotomy was safely performed with no early mortality.

Formation of a large aortic root abscess is an infrequent complication of aortic valve endocarditis in adults. Extrinsic compression of the coronary arteries by this abscess is still rarer. Here, we report a case of a 22-year-old male with aortic root abscess, who presented 2 months after the completion of treatment of endocarditis with exertional angina. Coronary angiogram revealed compression of proximal left anterior descending and left circumflex arteries by the abscess. The patient was successfully treated with pericardial patch exclusion of the abscess cavity and coronary artery bypass graft. The presentation of aortic root abscess with myocardial ischemia as a late complication of treated endocarditis has not been reported earlier.

A 25-year old acyanotic lady with unclear pulmonary venous drainage and a dilated coronary sinus was catheterized. Left pulmonary veins drained into coronary sinus in a left pulmonary vein angiogram done through the coronary sinus with a National Institute of Health 7F catheter. After the angiogram, the catheter got entrapped in a coronary sinus tributary and could be removed only by surgery. The left pulmonary veins were rerouted into the left atrium by unroofing the coronary sinus. Surgery is the treatment of choice for entrapped catheters when the primary condition itself merits surgical correction.

INTRODUCTION Percutaneous device closure of atrial septal defect (ASD) has emerged as an alternative to traditional surgical closure. Although reduced hospital stay, decreased morbidity and absence of a surgical incision are beneficial, other procedure- or device-related complications are coming into light. We report a rare complication of early embolization of the Blockaid septal occluder into the main pulmonary artery bifurcation associated with 'aortic rim' erosion and present a brief review of literature pertaining to the high incidence of complications associated with deficient or eroded 'aortic rims' necessitating surgical intervention. MATERIALS AND METHODS An 18-year-old male underwent successful percutaneous device closure of a 24.5 mm ASD after fulfilling institutional criteria for the procedure. The device used was a Blockaid septal occluder, a device morphologically similar to the Amplatzer device. The subsequent day, he had embolization of the device into the main pulmonary artery bifurcation, and underwent emergency surgical retrieval of the same with closure of the ASD. At surgery the ASD was found to have an eroded aortic rim. COMMENTS We believe that embolization of the percutaneous septal occluder in our patient was due to a combination of factors including an inadequate aortic rim; a grossly oversized device which eroded the aortic rim; and the Blockaid septal occluder, whose formally untested design and configuration could have led to its migration. CONCLUSION Strict selection criteria governing an 'adequate' aortic rim, the size of the device, and the choice of the device may help reduce the incidence of complications like the rare, but potentially fatal embolization of the device into the pulmonary artery following percutaneous device closure of an ASD.

A 55-year-old diabetic, hypertensive and dyslipidemic male with functional class III angina was admitted for coronary revascularization. Patient had a history of stroke with left hemiparesis five years ago, with complete recovery within a year. He had one episode of seizure three years back but did not seek any medical advice. Cardiac evaluation revealed triple vessel disease with fair left ventricular function without any intracardiac clots. Liver function test revealed SGOT of 48 u/L and SGPT of 56 u/L (normal range up to 40 u/l). Ultrasonography of abdomen showed fatty liver. Carotid artery duplex scanning showed 30% stenosis of right and 45% stenosis of left internal carotid artery. Computerised tomography (CT) of brain revealed chronic infarct in right frontal and gangliocapsular region. Electroencephalogram three weeks prior to surgery showed a spike and wave discharge over temporal areas consistent with seizure disorder, and patient was started on oral Phenytoin 100 mg thrice daily. He underwent coronary artery bypass grafting under CPB. Postoperatively hemodynamics remained stable. Oral aspirin and Phenytoin were restarted on first postoperative day. He was initially in a state of confusion, and, on the 3rd postoperative day, developed pronounced ataxia, nystagmus, dysarthria and vomiting. A likely clinical diagnosis of posterior circulation stroke was considered. CT scan ruled out a hemorrhagic stroke but could not rule out new embolic phenomena. Heparin infusion was thus started empirically. The neurological status was slowly deteriorating. MRI done on the fifth postoperative day revealed no fresh structural lesions in the brain. At this stage a likely possibility of Phenytoin toxicity was considered. Serum total Phenytoin concentration estimation revealed a toxic level of 40 microgram/ deciliter. (Therapeutic range 10-20 mcg/dl) which clinched the diagnosis. Patient also had hyponatremia requiring frequent corrections, however levels of urinary sodium were low. Phenytoin was stopped and patient showed good recovery with no residual neurological deficit within 15 days. At discharge his serum Phenytoin level was within normal range and he was advised to remain under a neurologist follow up.

Scimitar syndrome is a rare variant of partial anomalous pulmonary venous connection. The combination of scimitar syndrome with anomalous connection of the left superior pulmonary vein to the left innominate vein is extremely rare, and is yet to be documented in literature. We report the successful single-stage correction of such a rare type of anomalous pulmonary venous connection.

Separation of fine coal particles from the associated mineral matter is achieved either by flotation or flocculation. Such a separation process relies on the surface modification of the components involved. Flotation is mainly accomplished with the addition of a suitable collector molecule to the coal slurry and flocculation makes use of synthetic flocculants such as polyacrylamide and polyethylene oxides. In the latter case, the interaction between coal particles and the polymer flocculant is considered to be non-specific and often results in inefficient flocculation. In the present study a microorganism, Mycobacterium phlei , has been used as a bioflocculant in the separation of combustibles from Illinois #6 and Kentucky #9 coals. This bacterium was reported to be negatively charged and highly hydrophobic. The flocculation phenomenon was explained based on the interactions between the coal particles and the bacteria. The results suggested that the hydrophobic interactions play a dominant role. The aggregated coal flocs were found to contain some pyrite and mineral matter due to similar settling velocities. However, improved separation of combustibles was accomplished by column flotation using a frother and nitrogen gas.

The selective adhesion of hydrophobic Mycobacterium phlei to coal particles is responsible for flocculation of fine coal from its associated ash forming minerals. The driving force for the differential adhesion is the hydrophobic interactions between the surface of the organism through its constituents such as fatty acids and coal particles. The effect of Mycobacterium phlei on surface hydrophobicity, surface charge and mechanism of adhesion on coal and associated minerals are controlled by several factors including hydrophobicity and surface and solution chemistry of the system. Adhesion measurements indicate that maximum adhesion occurs below the iso-electric point (IEP) of the coal particles. While massive adhesion of Mycobacterium phlei is observed on coal, only negligible amount of Mycobacterium phlei attached to pyrite and quartz.

The bacterium Mycobacterium phlei is highly hydrophobic and negatively charged. It has specificity for selective adhesion to fine coal particles, mainly due to hydrophobic interaction. However, it does not attach to pyrite and ash-forming minerals present in the coal matrix. Results have shown that this bacterium is an excellent flocculant for fine coal. Not only are the coal particles visibly aggregated, but the optical micrograph has shown that the coal particles are held in the aggregate by adhesion and bacterial bridging. With Mycobacterium phlei, the flocculation characteristic of coal is markedly different from that usually observed with synthetic polymeric flocculants. In particular, the entwining characteristics of the long chain molecules of synthetic flocculants are absent in the case of Mycobacterium phlei. Since the hydrophobic interactions between the adhering particles are of greater importance in the formation of particle aggregation, the flocculation process is very selective.

A pacing system infection may lead to infective endocarditis and systemic sepsis. Tricuspid valve surgery may be required if the valve is severely damaged in the process of endocarditis. Although, cardiopulmonary bypass is the safe choice for performing right-heart procedures, it may carry risk of inducing systemic inflammatory response and multi-organ dysfunction. Some studies have advocated TV surgery without institution of CPB. We report tricuspid valve excision using the off-pump inflow occlusion technique in a 68-year-old man. We also describe role of intra-operative TEE as a monitoring tool at different stages of the surgical procedure. .

The computer-based control and the implementation of an energy-efficient pressure cycle comminution technique for ore reduction are presented. The effects of various parameters, such as permeability, porosity, saturation time, and applied pressure, on process performance and modeling of a machine designed to reduce the particle size of porous material in tension through the use of rapid depressurization of water-saturated ore are discussed. In addition, the synergistic effect of surface energy modifiers and pressurization to achieve better performance is discussed. >

Objective: Homologous blood transfusion after open heart surgery puts a tremendous load on the blood banks. This prospective randomized study evaluates the efficacy of infusing back residual cardiopulmonary bypass (CPB) circuit i.e., pump blood as a means to reduce homologous transfusion after coronary artery bypass surgery (CABG) and whether its use increases postoperative drainage. Materials and Methods: Sixty-seven consecutive patients who underwent elective CABGs under CPB were randomized into 2 groups: (1) cases where residual pump blood was used and (2) controls where residual pump blood was not used. Patients were monitored for hourly drainage on the day of surgery and the 1 st postoperative day and the requirements of homologous blood and its products. Data were matched regarding change in Hemoglobin, Packed Cell Volume and coagulation parameters till 1st postoperative day. All cases were followed up for three years. Results: There was a marginal reduction in bleeding pattern in the early postoperative period in the cases compared to controls. The requirement of homologous blood and its products were also reduced in the cases. Conclusions: The use of CPB circuit blood is safe in the immediate postoperative period. The requirement of homologous blood transfusion can come down if strict transfusion criteria are maintained.

Postoperative studies in patients with chronic thromboembolic pulmonary hypertension (CTPH) have shown that pulmonary thromboembolectomy (PTE) results in a rapid decrease of right ventricular (RV) size, improvement in the RV systolic function and left ventricular (LV) diastolic function. However, the extent to which the biventricular function recovers immediately after embolectomy in post-cardiopulmonary bypass period is not clear. A 45-year-old male patient was operated for retrieval of thrombus from pulmonary trunk and right pulmonary artery. Intraoperative transesophageal echocardiography (TOE) before surgery revealed signs of RV dysfunction and enlargement. The interventricular septum was seen moving paradoxically during end-systole and early-diastole. E/A ratio on transmitral Doppler flow velocity profile was about 0.63 and S/D ratio on pulmonary venous Doppler profile was 2.25, indicative of LV diastolic dysfunction. After weaning the patient from bypass, navigation on TOE showed marginal recovery of the RV systolic function and abatement of septal paradox to some extent. However, significant improvement was observed in the LV diastolic parameter (normal E/A ratio, S/D ratio of 1.08). We conclude that the geometrically altered LV recovers more than the hypertrophied and hypokinetic RV in a patient with CTPH in the post-bypass period.

The principle of microwave drying of fine coal is based on the selective absorption of microwaves by water. Coal is a poor absorber of microwaves. As a result, water can be removed from fine coal by selectively heating water molecules. One of the difficult problems during microwave heating is the exact determination of temperature in the core of the materials. The electromagnetic energy absorption in coal/water mixtures during microwave drying is controlled by several factors including the dielectric properties of the constituents. In this paper, electromagnetic and thermal models of coal are presented that can predict the energy absorption and temperature distribution during microwave drying.

The flotability of Argonne Premium coals varying in rank has been correlated with the intrinsic moisture content and dielectric properties of the intrinsic water. It is shown that as the coal rank increases the intrisic moisture and dielectric constant of the coals decreases. The nature of intrinsic water present in the coal of different ranks has been characterized using a dielectric mixture model. The water present in lignite is different from that of sub-bituminous and bituminous coals. The flotability of coals of various ranks is explained in terms of the nature and extent of the intrinsic water

Bulk single crystals of CdZnTe compound semiconductor is used for room temperature radiation detection in commercial radiation sensors. A large volume of detector material with low defect density is required for increasing the detection efficiency. Manufacture of such a bulky detector-quality material with low defect density is expensive. In this communication, synthesis of nanowires arrays of CdZnTe that can be used for detecting low energy radiation is reported for the first time. CdZnTe ternary compound semiconductor, referred as CZT, was electrodeposited in the form of nanowires onto a TiO2 nanotubular template in non-aqueous electrolytes using a pulse-reverse process at 130 oC. Very high electrical resistivity of the CZT nanowires (in the order of 10 10 Ω-cm) was obtained. Such a high resistivity was attributed to the presence of deep defect states such as cadmium vacancies created by the anodic cycle of the pulse-reverse electrodeposition process. Stacks of series connected CZT nanowire arrays were impressed with different bias potentials. The leakage current was in the order of tens of PicoAmperes. When exposed to a radiation source (Am -241, 60 keV), the current flow in the circuit increased. The preliminary results indicate that the CZT nanowire arrays can be used as radiation detector materials at room temperature with a much low bias potential (0.7 – 2.3 V) as against 300 – 500 V applied to the bulk detector materials.

The application of microwaves has a demonstrated potential for the ultimate removal of water from fine coal. The electromagnetic energy absorption in coal during microwave drying is controlled by several factors, with dielectric properties being among the most important. In this paper, the measured dielectric properties of various ranks of coal are presented as a function of frequency and moisture content. A knowledge of the dielectric properties is essential in estimating the electromagnetic energy absorption in coal during microwave heating.

Gastrointestinal bleeding due to angiodysplasia of the large intestine associated with calcific aortic stenosis is a well-known entity. Angiodysplasias are artero-venous malformations and they form one of the common causes of occult gastro-intestinal bleeding in the elderly. A 59-year-old man underwent aortic valve replacement for severe aortic regurgitation, developed severe gastro intestinal bleeding. Selective angiography was inconclusive. Exploratory laparotomy revealed angiodysplasia of the terminal ileum, which was resected. We report this case to draw attention to this rare cause of gastro intestinal bleeding and the difficulty in arriving at a diagnosis by the usual investigations. q 2003 Elsevier B.V. All rights reserved.

The following describes the objectives of Project Activity 023 “Second Generation Waste Package Design Study” under DOE Cooperative Agreement DE-FC28-04RW12232. The objectives of this activity are: to review the current YMP baseline environment and establish corrosion testenvironments representative of the range of dry to intermittently wet conditions expected in the drifts as a function of time; to demonstrate the oxidation and corrosion resistance of A588 weathering steel and reference Alloy 22 samples in the representative dry to intermittently dry conditions; and to evaluate backfill and design features to improve the thermal performance analyses of the proposed second-generation waste packages using existing models developed at the University of Nevada, Reno(UNR). The work plan for this project activity consists of three major tasks: Task 1. Definition of expected worst-case environments (humidity, liquid composition and temperature) at waste package outer surfaces as a function of time, and comparison with environments defined in the YMP baseline; Task 2. Oxidation and corrosion tests of proposed second-generation outer container material; and Task 3. Second Generation waste package thermal analyses. Full funding was not provided for this project activity.

Superior type of sinus venosus atrial septal defect (SVASD) is invariably associated with the unroofing of right upper pulmonary vein (RUPV). Warden procedure and pericardial patch repair with rerouting of the RUPV are commonly performed operations for the superior SVASD. Both operations involve the risk of obstruction to the flow of superior vena cava or rerouted pulmonary vein in the postoperative period. The sinus venosus defects are well visualized on the transesophageal echocardiography (TEE) because of the proximity of the TEE probe to these structures. We are reporting two cases operated for the superior SVASD with unroofed RUPV, highlighting the intraoperative echocardiographic features before and after the surgery.

Delayed development of left ventricular pseudoaneurysm is a rare late complication of mitral valve prosthesis and requires early surgical intervention. Here we describe the occurrence of such a complication diagnosed 6-months after the valve surgery in a 60-year-old lady. The anatomic delineation of subannular left ventricular pseudoaneurysm using multiple imaging modalities including CT angiography is also being discussed.

A single step pulsed potential electrodeposition of cadmium zinc telluride (CZT) nanowires was carried out in propylene carbonate solution at 130°C onto a nanotubular TiO2 template. Various combinations of potential pulses were investigated and the electrochemical parameters were optimised to obtain nanowires with a stoichiometry of Cd0.96Zn0.04Te. The CZT nanowires showed an electrical resistivity of 4.48 × 109 Ω-cm and an electronic band gap of 1.53 eV after annealing at 350°C for 1 h in argon atmosphere. The CZT nanowires grown on semiconductor nanotubular TiO2 templates can be integrated into a detection device for sensing low-medium energy gamma rays.

The dielectric properties of different ranks of Argonne Premium coal samples have been measured using an automated network analyzer system in the frequency range 0.3MHz to 3GHz. These measurements indicate that the inherent moisture present in the various ranks ofcoal has dielectric properties which are different from that of free water. The dielectric properties were also observed to increase with the moisture content as well as with the amount of oxygen present in the coal sample. A mixture model was successfully used topredict these dielectric properties.The measured dielectric properties have been incorporated into numerical calculations ofthe distribution of absorbed energy in coal irradiated with electromagnetic waves. The numerical technique used is the Method of Moments. Subsequently, the temperature distribution obtained in the coal is evaluated using a Finite Difference technique to solve the heat conduction equation. These calculations should prove very useful in the microwave drying of coal where it is difficult to monitor the temperature using probes.

The dispersion of oily collector has a significant effect on the flotation recovery of ultrafine coal. Generally, reagent dispersion is accomplished by mechanical mixing and/or ultrasonic agitation, followed by direct addition of dispersed collector into the flotation cell. Such dispersion and reagent addition techniques are invariably inadequate and nonselective. A new collector addition technique involving gas phase transport of atomized collector has shown improved results when compared to conventional reagent addition techniques. This technique involves atomization of the collector into the air stream. Under these circumstances, an aerosol is introduced into the flotation cell. Initially, the oil is dispersed within the air phase (continuous with respect to oil), and the air phase is dispersed within the pulp (continuous with respect to aerosol). In the flotation cell, the atomized oil droplets coalesce on the bubble’s surface and create a de facto oil-encapsulated bubble. This approach provides excellent dispersion, increases selectivity, and, most significantly, increases the flotation rate of ultrafine coal. Atomization of collector/frother combinations yielded improved flotation recovery and maintained near uniform froth levels, which is a desirable feature in coal flotation. Microscopic examinations of the attachment of oil-coated bubbles at a coal surface were conducted by attachment time and contact angle measurements. Oil-coated bubbles attach at significantly faster rates and with a higher contact angle than oil-free bubbles.

The chemistry of coal flotation has received considerable attention in recent years. Most of the research effort has been concerned with the characterization of the coal surface and adsorption reactions, which modulate the hydrophobic/hydrophillic balance at the coal surface. With the possible exception of oxygen very few experimental results have been reported regarding the effect of gas-phase composition on the flotation recovery of coal. Preliminary experimental results which indicate that improved fine coal flotation can be achieved using carbon dioxide are presented and discussed.

The flocculation of coal is typically accomplished by the addition of commercially available polymeric flocculants. Recently it was shown that biopolymers derived from microorganisms can also be used. The biopolymers flocculate coal efficiently and make the coal more hydrophobic. This increase in hydrophobicity can be utilized to separate coal flocs and can be used for reducing the moisture content of the flocculated coal. In this regard, flocculation and settling tests using biopolymers and synthetic flocculants were performed on fine coal. The experimental results are discussed and a transport model is presented for the time-dependent settling of fine coal.