Comparison of back propagation network and radial basis function network in Departure from Nucleate Boiling Ratio (DNBR) calculation

Since estimating the minimum departure from nucleate boiling ratio (MDNBR) requires complex calculations, an alternative method has always been considered. One of these methods is neural network. In this study, the Back Propagation Neural network (BPN) and Radial Basis Function Neural network (RBFN) are introduced and compared in order to estimate MDNBR of the VVER-1000 light water reactor. In these networks, the MDNBR were predicted with the inputs including core mass flux, core inlet temperature, pressure, reactor power level and position of the control rods. To obtain the data required to design these neural networks, an externally coupledcode was developed and its ability to estimate the thermo-hydraulic parameters of the VVER-1000 reactor was compared with other numerical solutions of this benchmark and the Final Safety Analysis Report (FSAR). After ensuring the accuracy of this coupled-code, MDNBR was calculated for 272 different conditions of reactor operating, and it was used to design BPN and RBFN. Comparison of these two neural networks revealed that when the output SMEs of the two systems were approximately the same, the training process in RBFN was much faster than in BPN and the maximum network error in RBFN was less than in BPN.

Comparison of back propagation network and radial basis function network in Departure from Nucleate Boiling Ratio (DNBR) calculation

Since estimating the minimum departure from nucleate boiling ratio (MDNBR) requires complex calculations, an alternative method has always been considered. One of these methods is neural network. In this study, the Back Propagation Neural network (BPN) and Radial Basis Function Neural network (RBFN) are introduced and compared in order to estimate MDNBR of the VVER-1000 light water reactor. In these networks, the MDNBR were predicted with the inputs including core mass flux, core inlet temperature, pressure, reactor power level and position of the control rods. To obtain the data required to design these neural networks, an externally coupledcode was developed and its ability to estimate the thermo-hydraulic parameters of the VVER-1000 reactor was compared with other numerical solutions of this benchmark and the Final Safety Analysis Report (FSAR). After ensuring the accuracy of this coupled-code, MDNBR was calculated for 272 different conditions of reactor operating, and it was used to design BPN and RBFN. Comparison of these two neural networks revealed that when the output SMEs of the two systems were approximately the same, the training process in RBFN was much faster than in BPN and the maximum network error in RBFN was less than in BPN.

Deep eutectic-water binary solvent associations investigated by vibrational spectroscopy and chemometrics

Investigation of the behaviour of deep eutectic solvents (DESs) as novel green solvents in the presence of other solvents is of great interest. In this study the behaviour of a common natural DES, namely choline chloride-glycerol deep eutectic solvent (GDES), was studied in the presence of water. A detailed study of the association of the two solvents was performed by integration of two vibrational spectroscopic methods (FTIR and Raman spectroscopy) followed by multivariate analysis. Moreover, a binary mixture of glycerol (Gly) as one of the liquid constituents of GDES and water was explored under the same conditions. A quintuplet and ternary systems were resolved for GDES-water and Gly-water probes, respectively, using multivariate analysis of global data (multi-technique and multi-experiment data arrangements). The results confirmed that in the presence of water the GDES showed different behaviour from its components. Therefore, a DES can be introduced as an independent solvent with its unique properties. Also, different H-bond interaction energies of GDES and its pure components in the presence of water were shown by theoretical calculations based on a density functional theory framework. To investigate the effects of water on the structure of GDES, molecular dynamics (MD) simulations of GDES-water liquid mixtures were performed at 0.9 mole fraction of water.

Super RLuc8-sFv; a new luciferase-labeled probe for detection of human CD4+ cells

A probe has been designed, produced and assayed for the detection of T-helper cells. The sFv fragment fused to the C-terminus of super Renilla luciferase 8 (Super RLuc8) and the probe successfully used for detection of human CD4+ cells using luminometer.

Sleep Disorders in ESRD Patients Undergoing Hemodialysis

Kidney failure affects different aspects of normal life. Among different manifestations, sleep problem can be considered as a common complaint of ESRD (End Stage Renal Disease) patients. In this study, we aimed to investigate the interrelationship between sleep disorders in ESRD patients and their characteristics. Through a cross-sectional study (2010-2011), 88 ESRD patients undergoing maintenance hemodialysis thrice weekly were recruited to enter the study. We used a self-administered questionnaire into which the data were reflected. The patients selected their specific sleep disorders using a nine-item scale while the Epworth Sleepiness Scale (ESS) determined both the presence and severity of sleep disorders. The data was finally analyzed with their baseline characteristics, dialysis characteristics, medication/stimulants use, and clinical and biochemical parameters. Over 95% of the patients had, at least, one specific sleep disorder while the ESS revealed 36.36% of patients as normal, 59.09% as having mild sleep disorders, and 4.54% as having moderate to severe sleep disorders. Sleep disorders were significantly correlated with older ages (P=0.035), dialysis dose (P=0.001), blood creatinine levels (P=0.037), upper airways obstruction (P=0.035), hepatomegaly (P=0.006), hepatic failure (P=0.001), higher blood TSH levels (P=0.039), history of hypothyroidism (P=0.005), and the use of levodopa (P=0.004), anti-hypertensive medications (P=0.006), benzodiazepines (P=0.006), Eprex (Erythropoietin) (P=0.001), Venofer (Iron Sucrose Injection) (P=0.013), and phosphate-binders agents (P=0.018). Sleep disorders are common findings among ESRD patients and seem to be a more complicated issue than a simple accumulation of the wastes products in the body. Whatever the causes of sleep disorders are, disorder-specific treatments should be considered.

Oncoplastic surgery in breast conservation: a prospective evaluation of the patients, techniques, and oncologic outcomes

BACKGROUND

The oncologic efficacy of breast-conserving therapies has been established in recent decades. Oncoplastic breast surgery (OBS), as a leap forward in breast conservation, offers concomitant techniques of oncologic and plastic surgeries that grant better esthetic results. The outcomes of our oncoplastic surgeries from 2007 to 2012 are reported.

METHODS

A series of 258 cases with breast masses (18 benign and 240 carcinomas) were operated on by OBS techniques and prospectively followed. Neoadjuvant and adjuvant oncologic treatments were also delivered as indicated.

RESULTS

Free margins were obtained in 95% of cancer patients. During the 26 months of follow-up, local recurrence happened in 7 (2.9%) patients, of which 1 underwent oncologic therapies and 6 underwent completion mastectomy. Complications postponed adjuvant therapies in 3 (1.2%) patients. Postsurgically, metastases were diagnosed in 8 (3.3%) patients. Two patients (.8%) died of cancer.

CONCLUSIONS

Outcomes of OBS are oncologically acceptable with low frequencies of positive margins and recurrence, while cosmetic results are much improved by OBS.

Olfactory function after nasal plastic surgery

OBJECTIVE

Nasal plastic surgery is a common procedure, which may cause complications. Many patients are concerned about possible changes in the ability to smell. This study aimed to investigate the impact of nasal surgery, by itself, on the sense of smell in a group of patients with minimal endonasal pathologies and no pre-operative olfactory alterations.

METHODOLOGY

In this prospective study from January 2009 until January 2011, we evaluated post-rhinoplasty olfactory changes in a series of 100 rhinoplasty candidates. Olfactory evaluation was performed both subjectively and objectively. The subjective evaluation contained a 0-to-100 Visual Analogue Scale and a five-choice qualitative questionnaire; while, the objective evaluation was performed using the same odor variant of the University of Pennsylvania Smell Identification Test (UPSIT40). Then, the results were analyzed by age, sex, operation method, symptoms, and time-interval groups.

RESULTS

Subjective and objective scoring revealed no significant change in terms of postsurgical olfactory outcome. According to subjective grading, 26 patients had improvement, 61 had no change, and 13 had deterioration of the smell sense. Closed rhinoplasty resulted in a better smell outcome after surgery according to the Visual Analogue Quantitative Score (P = 0.034).

CONCLUSION

Rhinoplasty does not appear to significantly change the preexisting olfactory status.

Transient threshold shift after gunshot noise exposure

BACKGROUND

Many people, such as soldiers, are routinely exposed to gunshot noise during target practice. It is suspected that this high-intensity noise may affect audition through repeated Transient Threshold Shifts (TTS); it can also mechanically alter auditory components such as waves. This study investigates the scope of gunshot noise from the AK-47 rifle (Kalashnikov) and the impact on the shooters' audition.

METHODS

Forty soldiers (80 ears) were recruited in this study. They were all young and being exposed to gunshot noise for the first time. Gunshot characteristics were measured before exposure. The soldiers underwent auditory evaluation with Pure Tone Audiometry (PTA) and Oto-Acoustic Emission (OAE) once before exposure and immediately (less than one hour) after exposure.

RESULTS

The AK-47 gunshot noise pressure level varied between L(AIm) = 73.7 dBA to L(AIm) = 111.4 dBA. Fourteen participants had subclinical hearing impairment in their pre-exposure evaluation; this number increased to 16 after the exposure. Six months post-exposure and later, the number of cases with impairment had fallen to eight (improvement in 50%). Both pre- and post-exposure OAE results were within normal values, while PTA results indicated a significant threshold alteration only at 6 kHz.

CONCLUSION

The results of this study confirm that exposure to gunshot noise with no ear protection can represent a significant hazard for auditory function, especially at higher frequencies.

Postrhinoplasty acne formation: a case-control study

BACKGROUND

Acne formation is a common dermatological problem which, if left untreated, may lead to severe facial scars, a consideration that may be particularly important for patients who seek cosmetic surgery. Postrhinoplasty acne development has not yet been discussed in the literature. We therefore decided to evaluate the occurrence of acne in nasal plastic surgery in a case-control study.

SUBJECTS & METHODS

One hundred and twenty patients were selected for this case-control study and were then assigned to case and control groups, each consisting of 60 patients. None of the participants was a known case of acne and those with any specific skin condition were excluded from the study. The cases were patients whose external nasal structures had been affected by the procedure; the control group consisted of matched patients who were candidates for closed septoplasty. After the operation, acne formation was evaluated in all participants and a comparison was made between cases and controls looking at the surgical method employed, and at the patients' personal and family backgrounds.

RESULTS

Twelve patients, all from the case group, developed postsurgical acne; all these patients had undergone open rhinoplasty. Age, gender, family history for acne and recent medication use prior to the surgery showed no significant correlation with acne formation.

CONCLUSION

The incidence of acne after nasal plastic surgery was significantly higher than in the control group, especially when the method of surgery was open rhinoplasty.

A Novel Test to Differentiate Anosmic Malingerers from Actually Anosmic Patients

Background

The available olfactory evaluation tests are mainly subjective methods requiring patients’ collaboration. If, for any reason, the patients refuse to honestly report what they perceive, the test reliability will be questionable; this condition is potentially observable in malingering patients because of their financial or psychosocial incentives. In an olfactory discrimination test context, this study was aimed to design a test capable of distinguishing malingerer from actually anosmic or severely hyposmic patients.

Methods

The pilot experiment of our methodology study determined five substances (coffee, lemon, rosewater, thyme, and garlic) as qualified odors of a 20-item odor discrimination test and set its normal reference value at 15. Through two simulations, 70 normosmic participants emulated actual anosmia and also malingering. The outcome results were used to measure test reliability factors.

Results

During the malingering simulation, only seven participants were capable of keeping their scores at the test chance level with enough randomness in their sequences of answers while the actual anosmia simulation revealed that 39 had scores at the test chance level. Accordingly, the Tehran University Odor Discrimination Test (TUODT) was measured to have 90% sensitivity, 55.71% specificity, 67.02% positive predictive value, and 84.78%negative predictive value.

Conclusion

The TUODT is a relatively efficient method to identify anosmia malingerers.

Litigation after nasal plastic surgery

INTRODUCTION

Esthetic surgeries are among the commonest medical procedures in the world nowadays; and as statistics declare, there has been a rapid increase in the rate of rhinoplasty during the recent years. Hence, as the number of cosmetic surgeries rises, the increment in the number of physicians being sued is quite inevitable; either due to complication in rhinoplasties or even inability to fulfill the patients' expectations. This article aims to clarify the aspects of causes leading to these legal claims.

MATERIALS AND METHODS

We designed a retrospective study according to the available files in the Iranian Organization for Forensic Medicine in which physicians were sued for the outcomes of rhinoplasty through the years 2004 to 2010. In addition, information on the patients' demographic data, surgeons' specialty and experience, and method of anesthesia were also collected.

RESULTS

One hundred twenty six patients entered the study among which 77 (61%) were female and 49 (39%) male. Mean age was obtained as 26.9 ± 7.7yrs. Up to 79.4% of patients had complaints concerning the cosmetic outcomes, 39.7% with respiratory and 4.8% with olfactory problems. The reason to sue the physician had a significant relationship with the patients' age and sex, and also with the surgeons' experience.

CONCLUSION

There are multiple reasons impelling the patients to sue surgeons after rhinoplasty, some are related to physicians' malpractice and some to the patients' social and personal circumstances.

Impact of anti-tuberculosis therapy on plasma zinc status in childhood tuberculosis

This study compared plasma zinc levels in 15 children with active pulmonary tuberculosis, 15 malnourished children and 15 healthy children. Mean plasma zinc concentrations in children with tuberculosis (71.7 microg/dL) were not significantly different than the other 2 groups (72.5 and 76.9 microg/dL). The zinc status of the children with tuberculosis was evaluated after 2 months and 4 months of DOTS therapy. The serum zinc level during anti-tuberculosis therapy decreased after 1 month and then recovered to the initial level after 4 months of treatment.

Efficient electrocatalysis of L-cysteine oxidation at carbon ionic liquid electrode

The electrochemistry of L-cysteine (CySH) in neutral aqueous media was investigated using carbon ionic liquid electrode (CILE). Comparative experiments were carried out using glassy carbon electrodes. At CILE, highly reproducible and well-defined cyclic voltammograms were obtained for l-cysteine with a peak potential of 0.49V vs Ag/AgCl, showing that CILE manifests a good electrocatalytic activity toward oxidation of l-cysteine. A linear dynamic range of 2-210microM with an experimental detection limit of 2microM was obtained. The method was successfully applied to the determination of l-cysteine in a sample of soya milk. Cysteine oxidation at CILE does not result in deactivation of the electrode surface. Mechanistic studies showed that, at CILE, the overall CySH oxidation is controlled by the oxidation of the CyS(-) electroactive species.

Dynamic method as a simple approach for wide range pH measurements using optodes

In this paper, a flow system equipped with an optode has been suggested for wide range pH measurements. Triacetyl cellulose was used as the optode membrane in which different pH indicators were immobilized. For extending the pH range, the dynamic response rather than the steady-state response of the optode was measured. Since diffusion is the main process governing the system response, different parameters having influence on diffusion of the analyte into the membrane were optimized. Under the optimum conditions, wide range pH determination (up to 11 pH units) is simply achieved regardless of the pKa of the pH indicator immobilized in the membrane. To validate the application of the method different indicators with different structures and pKa values were tested and the results were all confirming the precision and accuracy of the method. The suggested method also has combined advantages of flow systems together with inherent advantages of kinetic systems.

Primary and acquired drug resistance in childhood tuberculosis

This study determined the resistance pattern of Mycobacterium tuberculosis to 4 first-line anti-tuberculosis drugs in children with pulmonary tuberculosis at the Iranian National Research Institute of Tuberculosis and Lung Diseases from 1999 to 2004. There were 350 children with positive cultures over the study period: 7 (2%) were resistant to at least one of the 4 anti-tuberculosis drugs. Primary resistance was detected in 4 cases and secondary resistance in 3 cases. Most cases (6) were among Afghan refugees. Resistance to rifampicin both in primary and secondary resistances was high, showing that children in the Islamic Republic of Iran face the threat of drug-resistant tuberculosis transmission.

CCD camera full range pH sensor array

Changes in colors of an array of optical sensors that responds in full pH range were recorded using a CCD camera. The data of the camera were transferred to the computer through a capture card. Simple software was written to read the specific color of each sensor. In order to associate sensor array responses with pH values, a number of different mathematics and chemometrics methods were investigated and compared. The results show that the use of "Microsoft Excel's Solver" provides results which are in very good agreement with those obtained with chemometric methods such as artificial neural network (ANN) and partial least square (PLS) methods.

Simultaneous spectrophotometric determination of Fe(III), Al(III) and Cu(II) by partial least-squares calibration method

A spectrophotometric method for simultaneous determination of Fe(III), Al(III) and Cu(II) using Alizarin Red S as a chelating agent was developed. The parameters controlling behavior of the system were investigated and optimum conditions were selected. A partial least-squares multivariate calibration method was used for the analysis of ternary mixtures of Fe(III), Al(III) and Cu(II) over the range of 450-6000, 140-4000 and 450-15000 ng ml(-1), respectively. Absorbance data were taken between 400 and 800 nm. Applying this method to simultaneous determination of these metal ions in several synthetic alloy solutions with total relative standard error of less than 5% validated the proposed method.

Flow injection analysis of riboflavin with chemiluminescence detection using a N-halo compounds-luminol system

A chemiluminescent method for the determination of riboflavin is described. The method is based on the chemiluminescence (CL) generated during the oxidation of luminol by N-bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) in alkaline medium. It was found that riboflavin could greatly enhance this CL intensity when present in the luminol solution. Based on this observation, a new flow-injection CL method for the determination of riboflavin is proposed in this paper. The detection limits were 7.5 ng/mL and 3.5 ng/mL of riboflavin for the NBS- and NCS-luminol CL systems, respectively. The relative CL intensity was linear, with riboflavin concentration in the range 19-600 ng/mL and 600-2000 ng/mL for the NBS-luminol CL system, and 12-200 ng/mL and 200-2000 ng/mL for the NCS-luminol CL system. The results obtained for the assay of pharmaceutical preparations compared well with those obtained by the official method and demonstrated good accuracy and precision.

Cloud point extraction, preconcentration and simultaneous spectrophotometric determination of nickel and cobalt in water samples

Cloud point extraction has been used for the preconcentration and simultaneous spectrophotometric determination of nickel and cobalt after the formation of a complex with 2-amino-cyclopentene-1-dithiocarboxylic acid (ACDA), and latter analysis by spectrophotometer using Triton X-114 as surfactant. The parameters affecting the separation phase and detection process were optimized. Under the optimum experimental conditions (i.e. pH=5, 0.07 mM ACDA, Triton X-114=0.25% (w/v)), calibration graphs were linear in the range of 20-500 and 20-200 microg l(-1) with detection limits of 10 and 7.5 microg l(-1) for Ni and Co, respectively. The method was applied to the determination of Ni and Co in natural and waste water samples with satisfactory results.

Flow-injection determination of isoniazid using sodium dichloroisocyanurate- and trichloroisocyanuric acid-luminol chemiluminescence systems

A chemiluminescent (CL) method for the determination of isoniazid is described. The method is based on the CL generated during the oxidation of luminol by sodium dichloroisocyanurate (SDCC) and trichloroisocyanuric acid (TCCA) in alkaline medium. It was found that isoniazid greatly enhances this CL intensity when present in the luminol solution. Based on this observation, a new flow-injection CL method for the determination of isoniazid has been proposed in this paper. The detection limits were 2 and 3 ng ml(-1) isoniazid for the SDCC-luminol and TCCA-luminol CL systems, respectively. The relative CL intensity was linear with the isoniazid concentration in the range of 4-100 and 100-200 ng ml(-1) for the SDCC-luminol CL system, and 6-200 and 200-1000 ng ml(-1) for the TCCA-luminol CL system. The results obtained for the assay of pharmaceutical preparations compared well with those obtained by the official methods and demonstrated good accuracy and precision.

Sensitive indirect spectrophotometric determination of isoniazid

A simple, rapid, sensitive and accurate indirect spectrophotometric method for the microdetermination of isoniazid (INH) in pure form and pharmaceutical formulations is developed. The procedure is based on the reaction of copper(II) with isoniazid in the presence of neocuproine (NC). In the presence of neocuproine, copper(II) is reduced easily by isoniazid to a Cu(I)-neocuproine complex, which shows an absorption maximum at 454 nm. By measuring the absorbance of the complex at this wavelength, isoniazid can be determined in the range 0.3-3.5 microgml-1. This method was applied to the determination of isoniazid in pharmaceutical formulation and enabled the determination of the isoniazid in microgram quantities (0.3-3.5 microgml-1). The results obtained for the assay of pharmaceutical preparations compared well with those obtained by the official method and demonstrated good accuracy and precision.