An Integrated Approach for Numerical Analysis of Coupled Flow and Heat Transfer in Co-rotating Twin Screw Extruders

The co-rotating twin screw extrusion process is widely employed in chemical industries for the processing of complex fluids including various polymers, suspensions, emulsions and gels. Here we propose a new integrated modeling strategy that is based on the numerical analysis of pressure-generating extrusion elements concomitantly with the pressure-losing extrusion elements of the co-rotating twin screw extrusion process for non-Newtonian fluids under nonisothermal conditions. The numerical analysis undertakes three-dimensional (3-D) finite element simulations of any multiple combinations of forwarding and reversing fully-flighted screw elements with other types of elements including kneading discs staggered in the forward or reverse configurations and the die. The abilities of the methodologies in simulating the coupled flow and heat transfer in industrially-relevant mixing sections or pressurization/die shaping are demonstrated with predictions of the degree of fill and typical velocity, deformation rate, stress magnitude, pressure distributions as functions of various operating parameters and basic twin screw extrusion geometries for a viscoplastic type generalized Newtonian fluid.

Infection prevention and control measures for acute respiratory infections in healthcare settings: an update

Viruses account for the majority of the acute respiratory tract infections (ARIs) globally with a mortality exceeding 4 million deaths per year. The most commonly encountered viruses, in order of frequency, include influenza, respiratory syncytial virus, parainfluenza and adenovirus. Current evidence suggests that the major mode of transmission of ARls is through large droplets, but transmission through contact (including hand contamination with subsequent self-inoculation) and infectious respiratory aerosols of various sizes and at short range (coined as "opportunistic" airborne transmission) may also occur for some pathogens. Opportunistic airborne transmission may occur when conducting highrisk aerosol generating procedures and airborne precautions will be required in this setting. General infection control measures effective for all respiratory viral infections are reviewed and followed by discussion on some of the common viruses, including severe acute respiratory syndrome (SARS) coronavirus and the recently discovered novel coronavirus.

Proarrhythmic safety of repeat doses of mirabegron in healthy subjects: a randomized, double-blind, placebo-, and active-controlled thorough QT study

Potential effects of the selective β(3)-adrenoceptor agonist mirabegron on cardiac repolarization were studied in healthy subjects. The four-arm, parallel, two-way crossover study was double-blind and placebo- and active (moxifloxacin)-controlled. After 2 baseline ECG days, subjects were randomized to one of eight treatment sequences (22 females and 22 males per sequence) of placebo crossed over with once-daily (10 days) 50, 100, or 200 mg mirabegron or a single 400-mg moxifloxacin dose on day 10. In each period, continuous ECGs were recorded at two baselines and on the last drug administration day. The lower one-sided 95% confidence interval for moxifloxacin effect on QTcI was >5 ms, demonstrating assay sensitivity. According to ICH E14 criteria, mirabegron did not cause QTcI prolongation at the 50-mg therapeutic and 100-mg supratherapeutic doses in either sex. Mirabegron prolonged QTcI interval at the 200-mg supratherapeutic dose (upper one-sided 95% CI >10 ms) in females, but not in males.

[Breast cancer centres in North Rhine-Westphalia - case volume trends 2004-2010]

BACKGROUND

To improve quality of breast cancer care, in 2004 the state of North Rhine-Westphalia (NRW), Germany, began to appoint 51 breast cancer centres. These centres comprise 91 hospitals performing breast cancer surgery which have - amongst other things - to fulfill minimum volume standards. The aim of our study was to analyse if the intended regionalisation of care from 252 hospitals performing breast cancer surgery formerly to the appointed hospitals had taken place by the year 2010.

METHODS

We used data for the years 2004-2010 from the agency for quality assurance in North Rhine-Westphalia concerning breast cancer care and analysed trends concerning the number of hospitals performing breast cancer surgery, case volumes, and achievement of minimum volume standards by performing descriptive and inferential statistics.

RESULTS

Between 2004 and 2010 the number of breast cancer cases increased by 36.6% from 12 975 to 17 724 cases (p<0.001, Wilcoxon test). Simultaneously, the number of hospitals performing breast cancer surgery decreased from 252 to 208 whereby more than double the number of planned hospitals still performed breast cancer surgery. The case volumes of the 71 appointed hospitals for which we had individual data over the entire period of time increased by 49.4% from 8 103 cases in year 2004 to 12 105 cases in 2010. Assuming that case volume trends of those 20 appointed hospitals of which we did not have individual data developed uniformly to all other appointed hospitals, the proportion of cases that were operated in not appointed hospitals decreased from 20% in year 2004 to 12.5% in 2010 (p<0.001, χ2 test). Simultaneously, the proportion of cases that were operated in hospitals not achieving minimum volume standards decreased from 42.7% in year 2004 to 12.1% in 2010 (p<0.001, χ2 test).

CONCLUSION

The establishment of breast cancer centres in NRW regionalised breast cancer surgery. In fact, in 2010 breast cancer surgery still took place in more than 100 not appointed hospitals. However, these hospitals were responsible for only a small proportion of breast cancer surgery.

Bacteriological Profile Of Ear Discharge And Their Antibiotic Sensitivity In Chronic Suppurative Otitis Media In Kashmir,India

The objective of the study was to study the microflora and the antibiograms of patients with chronic suppurative otitis media (CSOM) in Kashmir,in order to provide a guidelines for making a protocol for empirical antibiotic therapy. Study design:Prospective study Material and methods: This study was conducted on OPD basis in Department of Ear, Nose and Throat and HNS Government medical college Srinagar kashmir from july 2010 to june 1011 and one hundred twenty five(125) patients with unilateral or bilateral active chronic suppurative otitis media were prospectively studied.They had chronic ear discharge and had not received antibiotics for the previous five days. Swabs were taken from discharging ear's and sent to microbiological section of hospital were culture for bacteria was done Antibiotic sensitivity testing was done with standard antibiotic discs using Kirby-bauer disk diffusion method.4 Results:From the Clinical specimens off the 125 patients microbiological culture was positive in 110 specimens. The most common causal organisms isolated were Staphylococcus aureus (48%) including 8% of methcillin resistant staph aureus and Pseudomonas aeruginosa (16%) followed by coagulase negative.Antibiotic sensitivities of staph aureus (other than MRSA) showed that 72% isolates were sensitivity to gentamicin,55% to ciprofloxacin followed by 36% to cephalosporins (cetazidime,ceftriaxone) .For pseudomonas aeruginosa 72% isolates were sensitive to piperacillin/tazobactum 48% to ciprofloxacin and 32% to ceftazidime/ceftriaxone. Of the three antibiotics commonly available as topical eardrops,ciprofloxacin and gentamicin has the highest susceptibility rate. DOI: http://dx.doi.org/10.3329/bjms.v11i3.11731 Bangladesh Journal of Medical Science Vol. 11 No. 03 July’12

Anti-neutrophil cytoplasmic antibody-positive neutrophilic dermatosis of the dorsal hands

Neutrophilic dermatosis of the hands is a localized variant of Sweet syndrome (SS). It was first reported in 1995, and is an uncommon condition, with < 100 cases reported to date. The female preponderance, morphological and histological features, and response to treatment are similar to SS, but it differs in its distribution on the body. There may also be a lack of systemic features and inconsistent laboratory findings. Significantly, about half of all cases are associated with haematological problems, i.e. myelodysplasia and leukaemia. Other cases may be associated with ulcerative colitis or solid tumours. We describe a case of a 71-year-old man with neutrophilic dermatoses of the hands, who also had involvement of the lips. There was an associated rise in his anti-neutrophil cytoplasmic antibody level, which corresponded with the activity of the disease.

Upregulation of Ras/Raf/ERK1/2 signaling and ERK5 in the brain of autistic subjects

Autism is a neurodevelopmental disorder characterized by impairments in social interaction, verbal communication and repetitive behaviors. A number of studies have shown that the Ras/Raf/ERK1/2 (extracellular signal-regulated kinase) signaling pathway plays important roles in the genesis of neural progenitors, learning and memory. Ras/Raf/ERK1/2 and ERK5 have also been shown to have death-promoting apoptotic roles in neural cells. Recent studies have shown a possible association between neural cell death and autism. In addition, two recent studies reported that a deletion of a locus on chromosome 16, which included the mitogen-activated protein kinase 3 (MAPK3) gene that encodes ERK1, is associated with autism. Most recently, our laboratory detected that Ras/Raf/ERK1/2 signaling activities were significantly enhanced in the brain of BTBR mice that model autism, as they exhibit many autism-like behaviors. We thus hypothesized that Ras/Raf/ERK1/2 signaling and ERK5 could be abnormally regulated in the brain of autistic subjects. In this study, we show that the expression of Ras protein was significantly elevated in the frontal cortex of autistic subjects. C-Raf phosphorylation was increased in the frontal cortex, while both C-Raf and A-Raf activities were enhanced in the cerebellum of autistic subjects. We also detected that both the protein expression and activities of ERK1/2 were significantly upregulated in the frontal cortex of autistic subjects, but not in the cerebellum. Furthermore, we showed that ERK5 protein expression is upregulated in both frontal cortex and cerebellum of autistic subjects. These results suggest that the upregulation of Ras/Raf/ERK1/2 signaling and ERK5 activities mainly found in the frontal cortex of autistic subjects may be critically involved in the pathogenesis of autism.

Health disparities between Muslim and non-Muslim countries

We examined differences in health indicators and associated factors across countries according to the proportion of the population who are Muslim. Of 190 UN countries, 48 were classified as Muslim-majority countries (MMC) and 142 as non-MMC. Data on 41 potential determinants of health were obtained from 10 different data sources, and 4 primary outcome measures (male and female life expectancy, maternal mortality ratio and infant mortality rate) were analysed. Annual per capita expenditure on health in MMC was one-fifth that of non-MMC. Maternal mortality and infant mortality rates were twice as high in MMC as non-MMC. Adult literacy rate was significantly higher for non-MMC. Four significant predictors explained 52%-72% of the differences in health outcomes between the 2 groups: gross national income, literacy rate, access to clean water and level of corruption.

The surgical management of intercostal lung herniation using bioprosthesis

Lung hernia is a rare occurrence. Consequently there is little literature providing guidance to effective management. Classified as congenital or acquired, there are fewer than 300 cases described in current literature (1). We describe a unique method for the management of spontaneous rib fractures and, resulting posterior lung herniation in a 65 year old man following a bout of coughing.

Changes of the T-wave amplitude and angle: an early marker of altered ventricular repolarization in hypertension

BACKGROUND

The heterogeneity of ventricular repolarization is an important proarrhythmic factor. QT dispersion has been proposed to reflect the inhomogeneity of ventricular repolarization, but a poor reproducibility limits its clinical applicability. Reliable noninvasive methods to quantify abnormalities in ventricular repolarization are still lacking. The T-loop morphology analysis is a novel method aimed at quantifying ventricular repolarization.

HYPOTHESIS

To test the ability of the T-loop morphology analysis to discriminate between hypertensive patients and healthy subjects, 105 hypertensive patients (mean age 63.6 +/- 12.3 years) and 110 healthy controls (mean age 49.7 +/- 14.3 years) were evaluated.

METHODS

The maximum QT interval (QT maximum), the minimum QT interval (QT minimum), and their difference (QT dispersion) were calculated from a digitally recorded 12-lead electrocardiogram (ECG) in both study groups. X, Y, and Z leads were reconstructed from the 12-lead ECG, and the amplitude of the maximum T vector (T amplitude) and the angle between the maximum T vector and X axis (T angle) were calculated from the projection of the T loop in the frontal plane.

RESULTS

T amplitude (p < 0.001), T angle (p = 0.05), and QT dispersion (p = 0.04) were significantly different between hypertensive patients and controls, while QT maximum (p = 0.14) and QT minimum (p = 0.35) did not differ between the groups. T amplitude was the only marker which differed between hypertensive patients without ECG criteria for left ventricular hypertrophy and controls (p = 0.002).

CONCLUSIONS

T-loop features and particularly T amplitude are significantly different between hypertensive patients and healthy controls and may serve as early markers of repolarization abnormalities in a hypertensive population.

Optimum lead positioning for recording bipolar atrial electrocardiograms during sinus rhythm and atrial fibrillation

BACKGROUND

To date, Holter monitoring has been predominantly utilized in the investigation and monitoring of ventricular arrhythmias and myocardial ischemia. Whether currently employed lead configurations are optimal for recording atrial electrocardiograms (ECGs) is unknown.

HYPOTHESIS

This study was undertaken to determine which conventional and novel lead configurations are optimal for recording atrial electrical activity during sinus rhythm and atrial fibrillation.

METHODS

Recordings were performed on eight healthy volunteers in sinus rhythm and four patients in atrial fibrillation. Each subject had 10 ECGs of three bipolar and three augmented unipolar leads recorded during supine rest, while rising to upright, and during standing rest, yielding a total of 60 leads (30 bipolar leads). Each tracing was inspected by two observers, and parameters such as P-wave amplitude and duration, whether the P-wave onset was clearly seen, atrial fibrillatory-wave amplitude, and amplitude of noise during standing were scored.

RESULTS

Leads recording inferiorly and leftward orientated bipoles provided the best registration of sinus P waves. The P-wave amplitude in the standard bipolar C5 lead (0.12 +/- 0.02 mV) was, however, inferior to others such as recordings between C1 and C6 positions (P-wave amplitude 0.16 +/- 0.02 mV) or from below the right clavicle to the left upper quadrant of the abdomen (0.16 +/- 0.01 mV). Optimal recording of fibrillatory waves was from different leads, such as a bipole from below the left clavicle to a low C1 position (fibrillatory wave amplitude 0.27 +/- 0.03 mV).

CONCLUSION

When Holter recordings are performed for the investigation of atrial arrhythmias, nonstandard lead configurations provide superior recording of atrial electrical activity. We advocate the use of electrodes positioned from C1 to C6, from below the left clavicle to a low C1 position, and a vertically orientated lead from the manubium to the twelfth vertebra or the xiphisternum.

Relation of ventricular repolarization to cardiac cycle length in normal subjects, hypertrophic cardiomyopathy, and patients with myocardial infarction

BACKGROUND

Prolonged QT interval and QT dispersion have been reported to reflect an increased inhomogeneity of ventricular repolarization, which is believed to be responsible for the development of arrhythmic events in patients with long QT syndrome, coronary heart disease, and myocardial infarction, congestive heart failure, and hypertrophic cardiomyopathy (HC).

HYPOTHESIS

This study was undertaken to determine whether an abnormal QT/RR dynamicity may reflect autonomic imbalance and may contribute to arrhythmogenesis in patients with heart disease.

METHODS

The relation between QT, QTpeak (QTp), Tpeak-Tend (TpTe) intervals and cardiac cycle length was assessed in 70 normal subjects, 37 patients with HC, and 48 survivors of myocardial infarction (MI). A set of 10 consecutive electrocardiograms was evaluated automatically in each subject using QT Guard software (Marquette Medical Systems, Milwaukee, Wisc.).

RESULTS

In patients with HC, all intervals were significantly prolonged compared with normals (p < 0.001 for QT and QTp; p < 0.04 for TpTc); in survivors of MI, this was true for the maximum QT and QTp intervals (p < 0.05). A strong linear correlation between QT, QTp, and RR intervals was observed in normals and in patients with MI and HC (r = 0.65-0.59, 0.82-0.77, 0.79-0.74, respectively, p < 0.0001). TpTe interval only showed a weak correlation with heart rate in normals (r = 0.24, p < 0.05) and was rate-independent in both patient groups (p = NS). Compared with normals, the slopes of QT/RR and QTp/RR regression lines were significantly steeper in patients with MI and HC (0.0990-0.0883, 0.1597-0.1551, 0.1653-0.1486, respectively). Regression lines were neither parallel nor identical between normals and patients (T > 1.96, Z > 3.07). There was no difference in steepness for TpTeR/RR lines between groups (0.0110, 0.0076, 0.0163, respectively). TpTe/QTp ratio was similar in normals and in patients with MI and HC (0.30 +/- 0.03, 0.31 +/- 0.07, 0.30 +/- 0.04, respectively), in the absence of any correlation between QTp and TpTe intervals, suggesting disproportional prolongation of both components of QT interval.

CONCLUSION

Compared with normals, a progressive increase in QT and QTp intervals at slower heart rates in patients with MI and HC may indicate an enhanced variability of the early ventricular repolarization and may be one of the mechanisms of arrhythmogenesis.

Stability of the noninvasive baroreflex sensitivity assessment using cross-spectral analysis of heart rate and arterial blood pressure variabilities

BACKGROUND

Depressed baroreflex sensitivity (BRS), usually estimated using the invasive phenylephrine method or the nitroprusside test, is significantly and independently associated with an increased risk of malignant ventricular arrhythmias and sudden cardiac death in patients surviving acute myocardial infarction. Several investigators have compared the standard phenylephrine test and different noninvasive methods.

HYPOTHESIS

This study evaluated the influence of different body positions with different breathing regimes on cross-spectral baroreflex indices (coherence between the spectral densities of blood pressure and cardiac cycle variabilities) in both low- and high-frequency bands.

METHODS

The data were obtained in 103 patients (73 males, aged 53 +/- 12 years) with coronary artery disease and/or hypertension. Simultaneous electrocardiographic and noninvasive blood pressure recordings were obtained in each subject in both supine and sitting positions during both spontaneous and slow and fast controlled respiration (0.1 and 0.33 Hz).

RESULTS

The results show a significant bias and disagreement between noninvasive baroreflex sensitivity (BRS) indices. The mean values of the baroreflex in low frequency ranged from 5.0 +/- 5.3 to 10.1 +/- 7.9 ms/mmHg, while in high frequency, the mean values ranged from 6.6 +/- 6.1 to 10.1 +/- 7.9 ms/mmHg. The limits of agreement ranged from +/-1.7 to +/-4.1 ms/mmHg with bias from -1.0 to +0.7 ms/mmHg.

CONCLUSION

A comprehensive comparison of different methods shows that BRS estimated in low-frequency band in sitting position during spontaneous respiration is the most representative part of the global baroreflex gain.

[Long-term electrocardiogram]

The review deals with the technical and clinical advances achieved in the field of long-term electrocardiography over the past decades, and outlines possible future developments. The technological background is reviewed from the initial conception by Dr Norman J Holter up to the modern loop and implantable recorders. The contemporary clinical applicability is considered including arrhythmia monitoring, tracking the morphological electrocardiographic changes with particular attention to ischaemia monitoring, and high-precision electrocardiographic measurements related to the assessment of drug-induced myocardial repolarisation changes. The section on future outlook discusses the possibility of using long-term electrocardiograms for identification of patients at increased risk of sudden arrhythmic death that might be preventable by prophylactic use of implantable defibrillators.

Distribution of phosphorus compounds in corn processing

Distillers dried grains with solubles (DDGS) and corn gluten feed (CGF) are major coproducts of ethanol production from corn dry grind and wet milling facilities, respectively. These coproducts contain important nutrients, nevertheless, high levels of phosphorus (P). About 50-80% of the P in these products is in an organically bound form known as phytate. The phytate P in these products cannot be digested by nonruminant animals. Consequently, large quantities of phytate are deposited into the soil with the animal wastes which potentially could cause P pollution in soil and underground water resources. As regulations on the concentration of P material in ethanol production coproducts become more restrictive, measures need to be taken for effective extraction of phytate P from the coproducts to make these processes more environmentally compatible. Proper marketing of coproducts is critical to the overall economy of ethanol production facilities. In this study, distribution of P compounds in different streams of dry grind and wet milling operations was determined. In the dry grind process, the highest P concentration was found to be in the condensed distillers solubles (CDS) at about 1.34 wt.% (db). About 59% of P in this stream was in phosphates form. The highest concentration of P in the wet milling process was found in the light steep water at about 3.4 wt.% (db). In this stream, about 22% of P was attributed to phosphates.

[Repolarization homogeneity in patients after acute myocardial infarction assessed from long-term 12-lead electrocardiographic recordings]

BACKGROUND

Abnormal heterogeneity of myocardial electrophysiologic processes increases the risk of malignant arrhythmias. The aim of the studywas to assess changes ofrepolarization homogeneity in patients after acute myocardial infarction (MI) using morphological parameters obtained from long-term 12-lead electrocardiographic recordings.

METHODS

In the group of 200 patients (45 females, 155 males) a long-term (10 minutes supine) 12-lead electrocardiographic recording (SEER MC, GE Medical) was performed 48-72 hours after acute myocardial infarction. The following parameters were calculated using experimental software: total cosine R to T (TCRT) and Twave residuum (TWR). The results were correlated with Q wave evolution and left ventricular ejection fraction (LVEF).

RESULTS

Distinguishing the MI type (Q vs nonQ) the following values were obtained: TCRT: 0.17 +/- 0.61 vs 0.16 +/- 0.49, p = 0.52, absolute TWR: 21,200 +/- 21,700 vs 25,700 +/- 29,300, p = 0.3, relative TWR: 0.0012 +/- 0.0017 vs 0.0017 +/- 0.0026, p = 0.28. Stratification according to LVEF (< or = 40% vs > 40%) led to: TCRT: -0.03 +/- 0.66 vs 0.25 +/- 0.54, p = 0.01, absolute TWR: 29,700 +/- 32,400 vs 21,300 +/- 21,500, p = 0.14, relative TWR: 0.0021 +/- 0.0047 vs 0.0013 +/- 0.0021, p = 0.48.

CONCLUSION

TCRT is a robust measurement of the spatial angle between the QRS complex and T wave loops which is related to LVEF. The results concerning TWR might indicate that this parameter is independent of LVEF, which needs to be confirmed in further analyses in a larger population.