Comparison of absolute renal uptake by using Tc-99m MAG-3 and Tc-99m DMSA.

PURPOSE: The purpose of this study is to compare the value of absolute renal uptake (ARU %) in patients by using Tc-99m MAG-3 and Tc-99m DMSA scan. MATERIAL AND METHODS: Absolute renal uptake is calculated using Tc-99m MAG-3 and Tc-99m DMSA in renal scintigraphy, Itoh and Tauex kidney depth methods used, respectively. n = 40 adult patients of both genders were included. All patients underwent Tc-99m MAG-3 and Tc-99m DMSA, respectively. RESULTS: The values of ARU (%) were calculated separately in selected patients n = 40, (left = 17, right = 23 normal functioning kidneys) by MAG-3 and DMSA. Absolute renal uptake (%) of Tc-99m MAG-3 in left kidneys was found to be 15.2 ±â€…3.4, with spilt renal function 79.2 ±â€…14.7 and ARU (%) in right kidneys 16.2 ±â€…3.4 with spilt renal function 77.5 ±â€…19. Absolute renal uptake of Tc-99m DMSA in left kidneys was 17.5 ±â€…3.2 and in right kidneys 17.9 ±â€…4.5 with spilt renal function 81.8 ±â€…10.7 and 79.3 ±â€…13.8 for left and right kidney, respectively. Statistical analysis showed strong Pearson correlation. CONCLUSION: Absolute renal uptake % was found to be more reliable in cases of bilateral compromised kidneys. ARU (%) calculated by Tc-99m MAG-3 solely can be used as predictor of renal function. The use of Tc-99m MAG-3 has more advantages than Tc-99m DMSA alone in renal scintigraphy as dynamic scintigraphy gives less radiation burden to patient, more information regarding renal function, and shorter stay time at hospital in comparison to static renal imaging. SRF % is less reliable than ARU (%).

Gastric Metastasis from Invasive Lobular Breast Cancer, Resembling Primary Gastric Cancer.

Invasive lobular carcinoma (ILC) is the second most common subtype of invasive breast cancer and sometimes presents with an unusual metastatic pattern. Its gastric metastasis is difficult to differentiate from primary adenocarcinoma. This report presents a case of breast ILC for which the initial presentation was gastric metastasis. A 62-y-old woman presented with gastric outlet obstruction secondary to a gastric mass that had been diagnosed on upper gastrointestinal endoscopy and biopsy. The patient had been referred for 18F-FDG PET/CT for staging. The baseline 18F-FDG PET/CT scan demonstrated extensive axillary nodal and gastric metastases with a breast mass, which raised suspicion of a primary breast carcinoma. Distinguishing primary gastric adenocarcinoma from metastatic breast ILC is essential, considering that the 2 diagnoses lead to divergent treatments. Therefore, this entity needs to be considered in the differential diagnosis in clinical practice.

Technical modelling of solar photovoltaic water pumping system and evaluation of system performance and their socio-economic impact.

Water is a precious resource for agriculture and most of the land is irrigated by tube wells. Diesel engines and electricity-operated pumps are widely used to fulfill irrigation water requirements; such conventional systems are inefficient and costly. With rising concerns about global warming, it is important to choose renewable energy source. In this study, SPVWPS has been optimally designed considering the water requirement, solar resources, tilt angle and orientation, losses in both systems and performance ratio. A PVSyst and SoSiT simulation tools were used to perform simulation analysis of the designed solar photovoltaic WPS. After designing and performance analysis, farmers were interviewed during fieldwork to assess socioeconomic impacts. In the result section, performance of PV system is analyzed at various tilt angles and it is established that system installed at a 15° tilt angle is more efficient. The annual PV array virtual energy at MPP of designed photovoltaic system is 33342 kWh and the annual energy available to operate the WPS is 23502 kWh. Module array mismatch and ohmic wiring losses are 374.16 kWh and 298.83 kWh, respectively. The total annual water demand of the selected site is 80769 m³ and designed SPWPS pumped 75054 m³ of water, supplying 92.93% of the irrigation demand. The normalized values of the effective energy, system losses, collection losses and unused energy in the SPVWP system are 2.6 kW/kWp/day, 0.69 kW/kWp/day, 0.72 kW/kWp/day and 0.48 kW/kWp/day, respectively. The annual average performance ratio of the proposed system is 74.62%. The results of the interviews showed that 70% of farmers are extremely satisfied with the performance of SPVWPS and 84% of farmers indicated that they did not incur any operating costs. The unit cost of the SPWPS is 0.17 €/kWh, which is 56.41% and 19.04% less expensive than the cost of diesel and grid electricity.

Exascale applications: skin in the game.

As noted in Wikipedia, skin in the game refers to having 'incurred risk by being involved in achieving a goal', where 'skin is a synecdoche for the person involved, and game is the metaphor for actions on the field of play under discussion'. For exascale applications under development in the US Department of Energy Exascale Computing Project, nothing could be more apt, with the skin being exascale applications and the game being delivering comprehensive science-based computational applications that effectively exploit exascale high-performance computing technologies to provide breakthrough modelling and simulation and data science solutions. These solutions will yield high-confidence insights and answers to the most critical problems and challenges for the USA in scientific discovery, national security, energy assurance, economic competitiveness and advanced healthcare. This article is part of a discussion meeting issue 'Numerical algorithms for high-performance computational science'.

Effect of risk factors like age, gender, hypertension, diabetes, smoking, dyslipidemia on coronary artery disease in Karachiites with angiographical data of local population: Number, site, severity of coronary lesion.

The aim of this study was to determine the effect of major risk factors like age, gender, hypertension, diabetes, smoking, dyslipidemia on coronary artery disease in Karachiites and highlighted the angiographic data of local population like number of vessels involvement, site and severity of coronary lesions. This was a cross sectional analytical prospective study which was carried out at Abbasi Shaheed Hospital Karachi from August 2004 - July 2014. We includedfive hundred (500) consecutive patients (188 female & 312 male) between 26-80 years old, who came for coronary angiography with suspecting ischemic heart disease clinically or otherwise proven by relevant tests like ETT, ECHO, and Thallium stress test. Post PCI and CABG patients were excluded from study. During this study variables like age, gender, hypertension, diabetes, smoking and dyslipidemia were taken into account in relation to coronary artery disease in Karachiites. In addition we also assorted some important findings of coronary angiography like: number of vessels involved, site and severity lesions in our population and compared them with existing literature. Our study revealed that in our local population not only old age and male gender are potential threat for an early coronary artery disease but other variables like hypertension, diabetes, smoking, and dyslipidemia are also playing important role in coronary artery disease. It is also concluded that our population is more prone to multiple vessels involvement with almost involvement of LAD in majority of population.

Chaos and noise.

Simple dynamical systems--with a small number of degrees of freedom--can behave in a complex manner due to the presence of chaos. Such systems are most often (idealized) limiting cases of more realistic situations. Isolating a small number of dynamical degrees of freedom in a realistically coupled system generically yields reduced equations with terms that can have a stochastic interpretation. In situations where both noise and chaos can potentially exist, it is not immediately obvious how Lyapunov exponents, key to characterizing chaos, should be properly defined. In this paper, we show how to do this in a class of well-defined noise-driven dynamical systems, derived from an underlying Hamiltonian model.

Pharmacological and biological evaluation of extracts from Gratiola officinalis L. (Scrophulariaceae).

The crude extract of Gratiola officinalis and its n-hexane, chloroform, ethyl acetate, n-butanol and aqueous fractions were subjected to biological (Brine Shrimp Bioassay, Insecticidal and Phytotoxicity/Cytotoxic) and neuropharmacological (Head dip, Open field Forced swimming test, Sodium pentothal induced sleep) activities. Results obtained in this study indicated that at high concentration dose (1000µg/ml), all test samples showed 60-95% phytotoxicity. In crude extract, n-butanol and aqueous fractions produced more than 85% phytotoxicity. While low concentration (10µg/ml) dose showed 25-28% phytotoxicity in all test samples. The crude extract was devoid of any effect against the growth of Callosbruchus analis and Tribolium castaneum and caused 10 mortality of Rhyzopertha dominica. n-Hexane, chloroform, ethylacetate, n-butanol and aqueous fractions caused 50, 30, 40, 10 and 20% mortality respectively of C. analis where as chloroform, ethyl-acetate, aqueous and crude extract, n-hexane, ethyl-acetate fractions also caused low mortality (10%) of Tribolium castaneum and Rhyzopertha dominica respectively. In cytotoxic assay at 1000µg/ml concentration, n-butanol fraction produced 36.7% and the crude extract produced 13.3% mortality of brine shrimp, its aqueous fraction was inactive at all concentrations. The results of head dip, open field, mobility time and Pentothal Na induced sleep indicated that crude extract, n-butanol and ethylacetate fractions of G. officinalis had mild sedative effect. However aqueous fraction was found to produce a significant decrease in motor activities and potentiated the duration of sleep.

Nonparametric dark energy reconstruction from supernova data.

Understanding the origin of the accelerated expansion of the Universe poses one of the greatest challenges in physics today. Lacking a compelling fundamental theory to test, observational efforts are targeted at a better characterization of the underlying cause. If a new form of mass-energy, dark energy, is driving the acceleration, the redshift evolution of the equation of state parameter w(z) will hold essential clues as to its origin. To best exploit data from observations it is necessary to develop a robust and accurate reconstruction approach, with controlled errors, for w(z). We introduce a new, nonparametric method for solving the associated statistical inverse problem based on Gaussian process modeling and Markov chain Monte Carlo sampling. Applying this method to recent supernova measurements, we reconstruct the continuous history of w out to redshift z=1.5.

Diagnostic accuracy of Tc-99m-MIBI for breast carcinoma in correlation with mammography and sonography.

OBJECTIVE: To evaluate the accuracy of 99mTc-MIBI scintimammography (SMM) in differentiating malignant breast cancer from benign breast mass and in detecting axillary lymph node metastasis in comparison with mammography and ultrasonography. STUDY DESIGN: Comparative cross-sectional study. PLACE AND DURATION OF STUDY: At the Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN), Karachi, from December 2006 to May 2007. METHODOLOGY: A total of 28 patients (both with breast lumps or/and axillary masses) included were in the study. They underwent clinical examination, mammography and ultrasound imaging followed by planar SMM using a single head detector. All subjects received a 740-1110 MBq bolus injection of 99mTc-Sestamibi. 5-10 minutes and 1 hour delayed images were acquired after the injection. SMM scans were considered positive when there was focal area of increased radiotracer uptake. Qualitative (visual) as well as quantitative evaluation of scans was done and compared with ultrasound and mammography, taking histopathology as Gold standard. Sensitivity, specificity, negative and positive predictive values (NPV and PPV respectively) were determined. RESULTS: There were 22 patients presenting with breast lesions (20 palpable, 2 non-palpable) and 6 patients with axillary lump. Scintimammography accurately predicted malignant lesions in the breast (sensitivity 93.3%, specificity. 71.4%, PPV 87.5%, NPV 83.3%, overall accuracy 86.4%) as well as in patients with axillary metastasis (sensitivity 100%, specificity 66%, PPV 75%, NPV 100%, accuracy 83%). A combination of scintimammography with any other imaging modality provides better results than a single test to detect breast cancer. CONCLUSION: SMM has good diagnostic accuracy in the detection of breast cancer as well as in axillary metastasis in association with mammography and ultrasound.

Acoustic analysis of normal Saudi adult voices.

OBJECTIVE: To determine the acoustic differences between Saudi adult male and female voices, and to compare the acoustic variables of the Multidimensional Voice Program (MDVP) obtained from North American adults to a group of Saudi males and females. METHODS: A cross-sectional survey of normal adult male and female voices was conducted at King Abdulaziz University Hospital, Riyadh, Kingdom of Saudi Arabia between March 2007 and December 2008. Ninety-five Saudi subjects sustained the vowel /a/ 6 times, and the steady state portion of 3 samples was analyzed and compared with the samples of the KayPentax normative voice database. RESULTS: Significant differences were found between Saudi and North American KayPentax database groups. In the male subjects, 15 of 33 MDVP variables, and 10 of 33 variables in the female subjects were found to be significantly different from the KayPentax database. CONCLUSION: We conclude that the acoustical differences may reflect laryngeal anatomical or tissue differences between the Saudi and the KayPentax database.

Semiclassics of the chaotic quantum-classical transition.

We elucidate the basic physical mechanisms responsible for the quantum-classical transition in one-dimensional, bounded chaotic systems subject to unconditioned environmental interactions. We show that such a transition occurs due to the dual role of noise in regularizing the semiclassical Wigner function and averaging over fine structures in classical phase space. The results are interpreted in the context of applying recent advances in the theory of measurement and open systems to the semiclassical quantum regime. We use these methods to show how a local semiclassical picture is stabilized and can then be approximated by a classical distribution at later times. The general results are demonstrated explicitly via high-resolution numerical simulations of the quantum master equation for a chaotic Duffing oscillator.

Chest wall recurrence of breast cancer demonstrated on 99mTc-MIBI scintimammography.

BACKGROUND: The mastectomy site is usually assessed by clinical examination and ultrasonography for recurrence of breast cancer, although post-surgical and radiotherapy changes limit the accuracy of these methods. MRI has been used successfully but it remains an expensive modality and may not be readily available. Scintimammography is an alternative method which has the advantage of not being affected by post-operative morphological changes. AIM: To evaluate the usefulness of planar Tc-MIBI scintimammography and supine Tc-MIBI SPECT in the detection of chest wall recurrence post-mastectomy. METHODS: The study population comprised of 26 patients (mean age, 47.15 years; median age 47 years; age range, 22-77 years) with suspected chest wall recurrence of breast cancer on clinical examination. All patients received a 740-1000 MBq bolus i.v. injection of Tc-MIBI preferably in the pedal vein. At 5-10 min post-injection planar images were obtained in the prone lateral and supine anterior positions using a double-head gamma camera. After planar imaging supine SPECT was performed (64 projections, 64x64 matrix, 30 s.frame). MIBI uptake was scored as follows: 1 = normal uptake (compared with contralateral side); 2 = focal low uptake (equivocal); and 3 = focal high uptake (positive). All patients underwent excision biopsy or FNAC for tissue diagnosis. FNAC was considered sufficient if unequivocally positive. RESULTS: For the 26 patients, planar scintimammography was found true positive in 14 and true negative in seven. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 78%, 87.5%, 93%, 64% and 81%, respectively (P<0.001). SPECT showed a significantly higher overall sensitivity than planar imaging (89% vs. 78%; P<0.001). SPECT and planar imaging showed the same specificity (87.5%). SPECT showed a significantly higher negative predictive value and accuracy than planar imaging (78% vs. 64% and 88% vs. 81%, respectively; P<0.05). CONCLUSION: Scintimammography is a reliable diagnostic tool and appears accurate in the detection of chest wall recurrence. SPECT shows high positive predictive value and aids in the diagnosis of the chest wall recurrence with greater confidence.

Role of 99mTc-MIBI scintimammography and X-ray mammography in the diagnosis of locoregional recurrence of breast cancer.

OBJECTIVE: To evaluate the utility of Tc- MIBI scintimammography in the loco-regional recurrence of breast cancer and its comparison with mammography. METHODS: The study population comprised of 33 subjects (mean age, 44.9 +/- 14.1 years); evaluated for suspected loco-regional recurrence of breast cancer on clinical examination. All subjects received a 740-1000 MBq bolus IV injection of 99mTc-MIBI preferably in pedal vein. At 5-10 min and 60-90 min post injection planar images were obtained in prone lateral and supine anterior position using double head gamma camera. MIBI uptake was scored as follows: 1: as normal uptake (compared with contralateral side); 2: focal low intense uptake (equivocal); 3: focal high intense uptake (positive). Mammography was performed by two standard views of cranio-caudal and mediolateral oblique in 26 patients. All patients had either excision biopsy or fine needle aspiration cytology (FNAC) for tissue diagnosis. RESULTS: Out of 33 patients, 21 had confirmed as recurrence on hiostopathology/cytology. Scintimammography was found true positive in 18 and true negative in 11 patients. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 85.7%, 91.7%, 94.7%, 78.6% and 87.8% respectively. In comparison, mammography was true positive in 9 and true negative in 6 patients with sensitivity of 52.9%, specificity, 66.7%, PPV 75%, NPV 42.9% and accuracy 57.7%. CONCLUSION: Scintimammography has better diagnostic accuracy than mammography in the detection of loco-regional recurrence of breast cancer.

Assessment of viable myocardium by nitrate augmented 99mTc MIBI myocardial perfusion imaging.

OBJECTIVE: To determine the efficacy of 99mTcMIBI with nitrate administration for the detection of viable myocardium in patients with MI. METHODS: Thirty-five patients (31 men, 4 women; mean age 51.91 +/- 8.86 years, median = 50) with previous history of myocardial infarction (with mean duration of 11.50 +/- 11.4, median =4 months after MI) were included in the study. All patients underwent baseline rest and Nitroglycerine 99mTcMIBI myocardial perfusion imaging (2 day protocol). Fifteen out of 34 patients were also submitted for rest and redistribution TI-201 imaging (3 day protocol). The data were reconstructed in transaxial slices and then reoriented into short, vertical long and horizontal long axis slices. The images were divided into seven different segments for qualitative as well as semi quantitative analysis. The images were interpreted by two independent observers. The segments with tracer activity of more than 55% as compared to maximum, were considered as viable. RESULTS: In the baseline study with 99mTcMIBI, 168/245 (68.57%) were viable segments and these were increased to 197 (80.40%) in the Nitrate MIBI study (p = 0.001 vs. baseline). Total 21 (60%) out of 35 patients demonstrated viable myocardium. The concordance for viable segments detection between Nitroglycerine MIBI and redistribution TI-201 imaging was found in 100 out of 105 segments (95.24%) for 15 patients, with significant kappa = 0.746 +/- 0.079 SE. CONCLUSION: The data suggest that use of nitrate augmented 99mTcMIBI protocol in Cardiac SPECT imaging results in improved detection of viable but hypoperfused segments and achieves results similar to those from standard TI-201 rest and redistribution protocol.

A randomized clinical trial comparing 50mCi and 100mCi of iodine-131 for ablation of differentiated thyroid cancers.

OBJECTIVE: To compare the efficacy of low (50 mCi) and high dose (100 mCi) Iodine-131 in ablation of differentiated thyroid cancer remnants. METHODS: Baseline serum thyroglobulin (sTg), thyroglobulin antibody (Tg Ab) and diagnostic whole body iodine scan with 2 mCi of I-131 were performed in each individual. After 6 months serum Tg, Tg Ab (of-thyroxin) and WB iodine scan with 10 mCi of I-131 were done to assess the efficacy of the low and high dose of I-131. Iodine ablative therapy (IAT) was considered successful (complete ablation) if the I-131 whole body scan was negative and sTg level was undetectable. In case of positive scan and/or sTg level detectable the patient was considered as unsuccessfully/partially ablated. RESULTS: In group A, (high dose) successful IAT was seen in 12/20 (60%) patients. Of these 5/7 (71%) had follicular Carcinoma on histopathology and 7/13 (54%) had papillary Ca. In group B, (low dose) successful IAT was seen in 8/20 (40%) patients, out of which 3/10 (30%) had follicular Carcinoma on histopathology and had successful IAT. 5/10 (50%) patients with papillary Carcinoma had successful IAT. As far as histopathology is concerned, in group A, response to high dose I-131 was better in follicular type than papillary type. Whereas in group B, response to low dose I-131 was better in patients with papillary type than follicular. CONCLUSION: 100 mCi of radioactive Iodine-131 (I-131) is a more effective therapeutic dose than 50 mCi (I-131) in the treatment of differentiated thyroid cancer remnants. Furthermore, follicular Carcinoma respond better to 100 mCi I-131 than 50 mCi while papillary Carcinoma showed an almost equal response to both.

Emergence of chaos in quantum systems far from the classical limit.

The dynamical status of isolated quantum systems is unclear as conventional measures fail to detect chaos in such systems. However, when quantum systems are subjected to observation--as all experimental systems must be--their dynamics is no longer linear and, in the appropriate limit(s), the evolution of expectation values, conditioned on the observations, closely approaches the behavior of classical trajectories. Here we show, by analyzing a specific example, that microscopic continuously observed quantum systems, even far from any classical limit, can have a positive Lyapunov exponent, and thus be truly chaotic.

The semiclassical regime of the chaotic quantum-classical transition.

An analysis of the semiclassical regime of the quantum-classical transition is given for open, bounded, one-dimensional chaotic dynamical systems. Environmental fluctuations-characteristic of all realistic dynamical systems-suppress the development of a fine structure in classical phase space and damp nonlocal contributions to the semiclassical Wigner function, which would otherwise invalidate the approximation. This dual regularization of the singular nature of the semiclassical limit is demonstrated by a numerical investigation of the chaotic Duffing oscillator.

Chaos and quantum mechanics.

The relationship between chaos and quantum mechanics has been somewhat uneasy--even stormy, in the minds of some people. However, much of the confusion may stem from inappropriate comparisons using formal analyses. In contrast, our starting point here is that a complete dynamical description requires a full understanding of the evolution of measured systems, necessary to explain actual experimental results. This is of course true, both classically and quantum mechanically. Because the evolution of the physical state is now conditioned on measurement results, the dynamics of such systems is intrinsically nonlinear even at the level of distribution functions. Due to this feature, the physically more complete treatment reveals the existence of dynamical regimes--such as chaos--that have no direct counterpart in the linear (unobserved) case. Moreover, this treatment allows for understanding how an effective classical behavior can result from the dynamics of an observed quantum system, both at the level of trajectories as well as distribution functions. Finally, we have the striking prediction that time-series from measured quantum systems can be chaotic far from the classical regime, with Lyapunov exponents differing from their classical values. These predictions can be tested in next-generation experiments.

Inverse-scattering theory and the density perturbations from inflation.

We show how to use inverse-scattering theory as the basis for the inflationary reconstruction program, the goal of which is to gain information about the physics which drives inflation. Inverse-scattering theory provides an effective and well-motivated procedure, having a sound mathematical basis and being of sufficient generality that it can be considered the foundation for a nonparametric reconstruction program. We show how simple properties of the power spectrum translate directly into statements about the evolution of the background geometry during inflation.

Nonlinear and nonequilibrium dynamics in geomaterials.

The transition from linear to nonlinear dynamical elasticity in rocks is of considerable interest in seismic wave propagation as well as in understanding the basic dynamical processes in consolidated granular materials. We have carried out a careful experimental investigation of this transition for Berea and Fontainebleau sandstones. Below a well-characterized strain, the materials behave linearly, transitioning beyond that point to a nonlinear behavior which can be accurately captured by a simple macroscopic dynamical model. At even higher strains, effects due to a driven nonequilibrium state, and relaxation from it, complicate the characterization of the nonlinear behavior.