The Risk Assessment of Cancer Risk during Normal Operation of Tehran Research Reactor Due to Radioactive Gas Emission
In this research, the risk assessment of radiation hazard for the Research Nuclear Reactor has been studied. In the current study, the MCNPx computational code has been used and coupled with a developed program using MATLAB software to evaluate Total Effective Dose Equivalent (TEDE) and cancer risk according to the BEIR equations for various human organs. In this study, the risk assessment of cancer has been calculated for ten years after exposure, in each of body organs of different ages and sexes. Also, the risk assessment of cancer has been calculated in each of body organs of different ages and sexes due to exposure after the retirement of the reactor staff. According to obtained results, a conservative whole-body dose rate, during a year, is 0.261 Sv and the probability the cancer risk for women is more than men and for children is more than adults. It has been shown that thyroid cancer was more possible than others.
Iterative Image Reconstruction for Sparse-View Computed Tomography via Total Variation Regularization and Dictionary Learning
Recently, low-dose computed tomography (CT) has become highly desirable due to increasing attention to the potential risks of excessive radiation. For low-dose CT imaging, ensuring image quality while reducing radiation dose is a major challenge. To facilitate low-dose CT imaging, we propose an improved statistical iterative reconstruction scheme based on the Penalized Weighted Least Squares (PWLS) standard combined with total variation (TV) minimization and sparse dictionary learning (DL) to improve reconstruction performance. We call this method "PWLS-TV-DL". In order to evaluate the PWLS-TV-DL method, we performed experiments on digital phantoms and physical phantoms, respectively. The experimental results show that our method is in image quality and calculation. The efficiency is superior to other methods, which confirms the potential of its low-dose CT imaging.
Exploring the Safety of Sodium Glucose Co-Transporter-2 Inhibitors at the Imperial College London Diabetes Centre, UAE
Introduction: Sodium-glucose co-transporter-2 (SGLT2) inhibitors are a new class of oral anti-diabetic drugs with a unique mechanism of action. They are used to improve glycaemic control in adults with type 2 diabetes by enhancing urinary glucose excretion. In the UAE, there has been certainly an increased use of these medications. As with any new medication, there are safety considerations related to their use in patients with type two diabetes. A retrospective study was conducted at the three main centres of the Imperial College London Diabetes Centre. Methodology: All patients in electronic database (Diamond) from October 2014 to October 2017 were included with a minimum of six months usage of sodium glucose co-transporter inhibitors that comprise canagliflozin, dapagliflozin and empagliflozin. There were 15 paired sample biochemical and clinical correlations. The analysis was done at the start of the study, three months and six months apart. SPSS version 24 was used for this study. Conclusion: This study of sodium glucose co-transporter-2 inhibitors used showed significant reductions in weight, glycated haemoglobin A1C, systolic and diastolic blood pressures. As the case with systematic reviews, there were similar changes in liver enzymes, raised total cholesterol, low density lipopoptein and high density lipoprotein. There was slight improvement in estimated glomerular filtration rate too. Our analysis also showed that they increased in the incidence of urinary tract symptoms and incidence of urinary tract infections.
Absorbed Dose Estimation of 177Lu-DOTATOC in Adenocarcinoma Breast Cancer Bearing Mice
In this study, the absorbed dose of human organs after injection of 177Lu-DOTATOC was studied based on the biodistribution of the complex in adenocarcinoma breast cancer bearing mice. For this purpose, the biodistribution of the radiolabelled complex was studied and compartmental modeling was applied to calculate the absorbed dose with high precision. As expected, 177Lu-DOTATOC illustrated a notable specific uptake in tumor and pancreas, organs with high level of somatostatin receptor on their surface and the effectiveness of the radio-conjugate for targeting of the breast adenocarcinoma tumors was indicated. The elicited results of modeling were the exponential equations, and those are utilized for obtaining the cumulated activity data by taking their integral. The results also exemplified that non-target absorbed-doses such as the liver, spleen and pancreas were approximately 0.008, 0.004, and 0.039, respectively. While these values were so much lower than target (tumor) absorbed-dose, it seems due to this low toxicity, this complex is a good agent for therapy.
Machine Learning Methods for Network Intrusion Detection
Network security engineers work to keep services available all the time by handling intruder attacks. Intrusion Detection System (IDS) is one of the obtainable mechanisms that is used to sense and classify any abnormal actions. Therefore, the IDS must be always up to date with the latest intruder attacks signatures to preserve confidentiality, integrity, and availability of the services. The speed of the IDS is a very important issue as well learning the new attacks. This research work illustrates how the Knowledge Discovery and Data Mining (or Knowledge Discovery in Databases) KDD dataset is very handy for testing and evaluating different Machine Learning Techniques. It mainly focuses on the KDD preprocess part in order to prepare a decent and fair experimental data set. The J48, MLP, and Bayes Network classifiers have been chosen for this study. It has been proven that the J48 classifier has achieved the highest accuracy rate for detecting and classifying all KDD dataset attacks, which are of type DOS, R2L, U2R, and PROBE.
An Earth Mover’s Distance Algorithm Based DDoS Detection Mechanism in SDN
Software-defined networking (SDN) provides a solution
for scalable network framework with decoupled control and data
plane. However, this architecture also induces a particular distributed
denial-of-service (DDoS) attack that can affect or even overwhelm
the SDN network. DDoS attack detection problem has to date been
mostly researched as entropy comparison problem. However, this
problem lacks the utilization of SDN, and the results are not accurate.
In this paper, we propose a DDoS attack detection method, which
interprets DDoS detection as a signature matching problem and is
formulated as Earth Mover’s Distance (EMD) model. Considering
the feasibility and accuracy, we further propose to define the cost
function of EMD to be a generalized Kullback-Leibler divergence.
Simulation results show that our proposed method can detect DDoS
attacks by comparing EMD values with the ones computed in the case
without attacks. Moreover, our method can significantly increase the
true positive rate of detection.
Estimation of Human Absorbed Dose Using Compartmental Model
Dosimetry is an indispensable and precious factor in patient treatment planning to minimize the absorbed dose in vital tissues. In this study, compartmental model was used in order to estimate the human absorbed dose of 177Lu-DOTATOC from the biodistribution data in wild type rats. For this purpose, 177Lu-DOTATOC was prepared under optimized conditions and its biodistribution was studied in male Syrian rats up to 168 h. Compartmental model was applied to mathematical description of the drug behaviour in tissue at different times. Dosimetric estimation of the complex was performed using radiation absorbed dose assessment resource (RADAR). The biodistribution data showed high accumulation in the adrenal and pancreas as the major expression sites for somatostatin receptor (SSTR). While kidneys as the major route of excretion receive 0.037 mSv/MBq, pancreas and adrenal also obtain 0.039 and 0.028 mSv/MBq. Due to the usage of this method, the points of accumulated activity data were enhanced, and further information of tissues uptake was collected that it will be followed by high (or improved) precision in dosimetric calculations.
Towards a Security Model against Denial of Service Attacks for SIP Traffic
Nowadays, security threats in Voice over IP (VoIP) systems are an essential and latent concern for people in charge of security in a corporate network, because, every day, new Denial-of-Service (DoS) attacks are developed. These affect the business continuity of an organization, regarding confidentiality, availability, and integrity of services, causing frequent losses of both information and money. The purpose of this study is to establish the necessary measures to mitigate DoS threats, which affect the availability of VoIP systems, based on the Session Initiation Protocol (SIP). A Security Model called MS-DoS-SIP is proposed, which is based on two approaches. The first one analyzes the recommendations of international security standards. The second approach takes into account weaknesses and threats. The implementation of this model in a VoIP simulated system allowed to minimize the present vulnerabilities in 92% and increase the availability time of the VoIP service into an organization.
Assessment of Occupational Exposure and Individual Radio-Sensitivity in People Subjected to Ionizing Radiation
The estimation of accumulated radiation doses in people professionally exposed to ionizing radiation was performed using methods of biological (chromosomal aberrations frequency in lymphocytes) and physical (radionuclides analysis in urine, whole-body radiation meter, individual thermoluminescent dosimeters) dosimetry. A group of 84 "A" category employees after their work in the territory of former Semipalatinsk test site (Kazakhstan) was investigated. The dose rate in some funnels exceeds 40 μSv/h. After radionuclides determination in urine using radiochemical and WBC methods, it was shown that the total effective dose of personnel internal exposure did not exceed 0.2 mSv/year, while an acceptable dose limit for staff is 20 mSv/year. The range of external radiation doses measured with individual thermo-luminescent dosimeters was 0.3-1.406 µSv. The cytogenetic examination showed that chromosomal aberrations frequency in staff was 4.27±0.22%, which is significantly higher than at the people from non-polluting settlement Tausugur (0.87±0.1%) (р ≤ 0.01) and citizens of Almaty (1.6±0.12%) (р≤ 0.01). Chromosomal type aberrations accounted for 2.32±0.16%, 0.27±0.06% of which were dicentrics and centric rings. The cytogenetic analysis of different types group radiosensitivity among «professionals» (age, sex, ethnic group, epidemiological data) revealed no significant differences between the compared values. Using various techniques by frequency of dicentrics and centric rings, the average cumulative radiation dose for group was calculated, and that was 0.084-0.143 Gy. To perform comparative individual dosimetry using physical and biological methods of dose assessment, calibration curves (including own ones) and regression equations based on general frequency of chromosomal aberrations obtained after irradiation of blood samples by gamma-radiation with the dose rate of 0,1 Gy/min were used. Herewith, on the assumption of individual variation of chromosomal aberrations frequency (1–10%), the accumulated dose of radiation varied 0-0.3 Gy. The main problem in the interpretation of individual dosimetry results is reduced to different reaction of the objects to irradiation - radiosensitivity, which dictates the need of quantitative definition of this individual reaction and its consideration in the calculation of the received radiation dose. The entire examined contingent was assigned to a group based on the received dose and detected cytogenetic aberrations. Radiosensitive individuals, at the lowest received dose in a year, showed the highest frequency of chromosomal aberrations (5.72%). In opposite, radioresistant individuals showed the lowest frequency of chromosomal aberrations (2.8%). The cohort correlation according to the criterion of radio-sensitivity in our research was distributed as follows: radio-sensitive (26.2%) — medium radio-sensitivity (57.1%), radioresistant (16.7%). Herewith, the dispersion for radioresistant individuals is 2.3; for the group with medium radio-sensitivity — 3.3; and for radio-sensitive group — 9. These data indicate the highest variation of characteristic (reactions to radiation effect) in the group of radio-sensitive individuals. People with medium radio-sensitivity show significant long-term correlation (0.66; n=48, β ≥ 0.999) between the values of doses defined according to the results of cytogenetic analysis and dose of external radiation obtained with the help of thermoluminescent dosimeters. Mathematical models based on the type of violation of the radiation dose according to the professionals radiosensitivity level were offered.
Comparison of Statins Dose Intensity on HbA1c Control in Outpatients with Type 2 Diabetes: A Prospective Cohort Study
The effect of statins dose intensity (SDI) on glycemic control in patients with existing diabetes is unclear. Also, there are many contradictory findings were reported in the literature; thus, it is limiting the possibility to draw conclusions. This project was designed to compare the effect of SDI on glycated hemoglobin (HbA1c%) control in outpatients with Type 2 diabetes in the endocrine clinic at Hospital Pulau Pinang, Malaysia, between July 2015 and August 2016. A prospective cohort study was conducted, where records of 345 patients with Type 2 diabetes (Moderate-SDI group 289 patients and high-SDI cohort 56 patients) were reviewed to identify demographics and laboratory tests. The target of glycemic control (HbA1c < 7% for patient < 65 years, and < 8% for patient ≥ 65 years) was estimated, and the results were presented as descriptive statistics. From 289 moderate-SDI cohorts with a mean age of 57.3 ± 12.4 years, only 86 (29.8%) cases were shown to have controlled glycemia, while there were 203 (70.2%) cases with uncontrolled glycemia with confidence interval (CI) of 95% (6.2–10.8). On the other hand, the high-SDI group of 56 patients with Type 2 diabetes with a mean age 57.7±12.4 years is distributed among 11 (19.6%) patients with controlled diabetes, and 45 (80.4%) of them had uncontrolled glycemia, CI: 95% (7.1–11.9). The study has demonstrated that the relative risk (RR) of uncontrolled glycemia in patients with Type 2 diabetes that used high-SDI is 1.15, and the excessive relative risk (ERR) is 15%. The absolute risk (AR) is 10.2%, and the number needed to harm (NNH) is 10. Outpatients with Type 2 diabetes who use high-SDI of statin have a higher risk of uncontrolled glycemia than outpatients who had been treated with a moderate-SDI.
Using SNAP and RADTRAD to Establish the Analysis Model for Maanshan PWR Plant
In this study, we focus on the establishment of the analysis model for Maanshan PWR nuclear power plant (NPP) by using RADTRAD and SNAP codes with the FSAR, manuals, and other data. In order to evaluate the cumulative dose at the Exclusion Area Boundary (EAB) and Low Population Zone (LPZ) outer boundary, Maanshan NPP RADTRAD/SNAP model was used to perform the analysis of the DBA LOCA case. The analysis results of RADTRAD were similar to FSAR data. These analysis results were lower than the failure criteria of 10 CFR 100.11 (a total radiation dose to the whole body, 250 mSv; a total radiation dose to the thyroid from iodine exposure, 3000 mSv).
Directionally-Sensitive Personal Wearable Radiation Dosimeter
In this paper, the authors propose a personal
wearable directionally-sensitive radiation dosimeter using multiple
semiconductor CdZnTe detectors. The proposed dosimeter not only
measures the real-time dose rate but also provide the direction of the
radioactive source. A linear relationship between radioactive source
direction and the radiation intensity measured by each detectors is
established and an equation to determine the source direction is
derived by the authors. The efficiency and accuracy of the proposed
dosimeter is verified by simulation using Geant4 package. Results
have indicated that in a measurement duration of about 7 seconds,
the proposed dosimeter was able to estimate the direction of a 10μCi
137/55Cs radioactive source to within 2 degrees.
Effective Dose and Size Specific Dose Estimation with and without Tube Current Modulation for Thoracic Computed Tomography Examinations: A Phantom Study
The purpose of this study is to reduce radiation dose for chest CT examination by including Tube Current Modulation (TCM) to a standard CT protocol. A scan of an anthropomorphic male Alderson phantom was performed on a 128-slice scanner. The estimation of effective dose (ED) in both scans with and without mAs modulation was done via multiplication of Dose Length Product (DLP) to a conversion factor. Results were compared to those measured with a CT-Expo software. The size specific dose estimation (SSDE) values were obtained by multiplication of the volume CT dose index (CTDIvol) with a conversion size factor related to the phantom’s effective diameter. Objective assessment of image quality was performed with Signal to Noise Ratio (SNR) measurements in phantom. SPSS software was used for data analysis. Results showed including CARE Dose 4D; ED was lowered by 48.35% and 51.51% using DLP and CT-expo, respectively. In addition, ED ranges between 7.01 mSv and 6.6 mSv in case of standard protocol, while it ranges between 3.62 mSv and 3.2 mSv with TCM. Similar results are found for SSDE; dose was higher without TCM of 16.25 mGy and was lower by 48.8% including TCM. The SNR values calculated were significantly different (p=0.03<0.05). The highest one is measured on images acquired with TCM and reconstructed with Filtered back projection (FBP). In conclusion, this study proves the potential of TCM technique in SSDE and ED reduction and in conserving image quality with high diagnostic reference level for thoracic CT examinations.
Management Software for the Elaboration of an Electronic File in the Pharmaceutical Industry Following Mexican Regulations
For certification, certain goods of public interest, such as medicines and food, it is required the preparation and delivery of a dossier. For its elaboration, legal and administrative knowledge must be taken, as well as organization of the documents of the process, and an order that allows the file verification. Therefore, a virtual platform was developed to support the process of management and elaboration of the dossier, providing accessibility to the information and interfaces that allow the user to know the status of projects. The development of dossier system on the cloud allows the inclusion of the technical requirements for the software management, including the validation and the manufacturing in the field industry. The platform guides and facilitates the dossier elaboration (report, file or history), considering Mexican legislation and regulations, it also has auxiliary tools for its management. This technological alternative provides organization support for documents and accessibility to the information required to specify the successful development of a dossier. The platform divides into the following modules: System control, catalog, dossier and enterprise management. The modules are designed per the structure required in a dossier in those areas. However, the structure allows for flexibility, as its goal is to become a tool that facilitates and does not obstruct processes. The architecture and development of the software allows flexibility for future work expansion to other fields, this would imply feeding the system with new regulations.
Characterization of an Extrapolation Chamber for Dosimetry of Low Energy X-Ray Beams
Extrapolation chambers were designed to be used as primary standard dosimeter for measuring absorbed dose in a medium in beta radiation and low energy x-rays. The International Organization for Standardization established series of reference x-radiation for calibrating and determining the energy dependence of dosimeters that are to be reproduced in metrology laboratories. Standardization of the low energy x-ray beams with tube potential lower than 30 kV may be affected by the instrument used for dosimetry. In this work, parameters of a 23392 model PTW extrapolation chamber were determined aiming its use in low energy x-ray beams as a reference instrument.
Radon-222 Concentration and Potential Risk to Workers of Al-Jalamid Phosphate Mines, North Province, Saudi Arabia
Usually, phosphate deposits contain 238U and 232Th in addition to their decay products. Due to their different pathways in the environment, the 238U/232Th activity concentration ratio usually found to be greater than unity in phosphate sediments. The presence of these radionuclides creates a potential need to control exposure of workers in the mining and processing activities of the phosphate minerals in accordance with IAEA safety standards. The greatest dose to workers comes from exposure to radon, especially 222Rn from the uranium series, and has to be controlled. In this regard, radon (222Rn) was measured in the atmosphere (indoor and outdoor) of Al-Jalamid phosphate-mines working area using a portable radon-measurement instrument RAD7, in a purpose of radiation protection. Radon was measured in 61 sites inside the open phosphate mines, the phosphate upgrading facility (offices and rooms of the workers, and in some open-air sites) and in the dwellings of the workers residence-village that lies at about 3 km from the mines working area. The obtained results indicated that the average indoor radon concentration was about 48.4 Bq/m3. Inside the upgrading facility, the average outdoor concentrations were 10.8 and 9.7 Bq/m3 in the concentrate piles and crushing areas, respectively. It was 12.3 Bq/m3 in the atmosphere of the open mines. These values are comparable with the global average values. Based on the average values, the annual effective dose due to radon inhalation was calculated and risk estimates have been done. The average annual effective dose to workers due to the radon inhalation was estimated by 1.32 mSv. The potential excess risk of lung cancer mortality that could be attributed to radon, when considering the lifetime exposure, was estimated by 53.0x10-4. The results have been discussed in detail.
Experimental and Analytical Dose Assessment of Patient's Family Members Treated with I-131
Radiation exposure to the patient's family members is one of the major concerns during thyroid cancer radionuclide therapy. The aim of this study was to measure the total effective dose of the family members by means of thermoluminescence personal dosimeter, and compare with those calculated by analytical methods. Eighty-five adult family members of fifty-one patients volunteered to participate in this research study. Considering the minimum and maximum range of dose rate from 15 µsv/h to 120 µsv/h at patients' release time, the calculated mean and median dose values of family members were 0.45 mSv and 0.28 mSv, respectively. Moreover, almost all family members’ doses were measured to be less than the dose constraint of 5 mSv recommended by Basic Safety Standards. Considering the influence parameters such as patient dose rate and administrated activity, the total effective doses of family members were calculated by TEDE and NRC formulas and compared with those of experimental results. The results indicated that, it is fruitful to use the quantitative calculations for releasing patients treated with I-131 and correct estimation of patients' family doses.
Effect of Gamma Radiation on Bromophenol Blue Dyed Films as Dosimeter
Ionizing radiation can cause a drastic change in the physical and chemical properties of the material exposed. Numerous medical devices are sterilized by ionizing radiation. In the current research paper, an attempt was made to develop precise and inexpensive polymeric film dosimeter which can be used for controlling radiation dosage. Polymeric film containing (pH sensitive dye) indicator dye Bromophenol blue (BPB) was casted to check the effect of Gamma radiation on its optical and physical properties. The film was exposed to gamma radiation at 4 kGy/hr in the range of 0 to 300 kGy at an interval of 50 kGy. Release of vinyl acetate from an emulsion on high radiation reacts with the BPB fading the color of the film from blue to light blue and then finally colorless, indicating a change in pH from basic to acidic form. The change was characterized by using CIE l*a*b*, ultra-violet spectroscopy and FT-IR respectively.
Radon Concentration in the Water Samples of Hassan District, Karnataka, India
Radon is a radioactive gas emitted from radium, a daughter product of uranium that occurs naturally in rocks and soil. Radon, together with its decay products, emits alpha particles that can damage lung tissue. The activity concentration of 222Ra has been analyzed in water samples collected from borewells and rivers in and around Hassan city, Karnataka State, India. The measurements were performed by Emanometry technique. The concentration of 222Rn in borewell waters varies from 18.49±1.89 to 397.26±12.3 Bql-1 with geometric mean 120.48±12.87 Bql-1 and in river waters it varies from 92.63±9.31 to 93.98±9.51 Bql-1 with geometric mean of 93.16±9.33 Bql-1. In the present study, the radon concentrations are higher in Adarshanagar and Viveka Nagar which are found to be 397.26±12.3 Bql-1 and 325.78±32.56 Bql-1. Most of the analysed samples show a 222Rn concentration more than 100 Bql-1 and this can be attributed to the geology of the area where the ground waters are located, which is predominantly of granitic characteristic. The average inhalation dose and ingestion dose in the borewell water are found to be 0.405 and 0.033 µSvy-1; and in river water it is found to be 0.234 and 0.019 µSvy-1, respectively. The average total effective dose rate in borewell waters and river waters are found to be 0.433 and 0.253 µSvy-1, which does not cause any health risk to the population of Hassan region.
Natural Radioactivity in Foods Consumed in Turkey
This study aims to determine the natural radioactivity levels in some foodstuffs produced in Turkey. For this purpose, 48 different foods samples were collected from different land parcels throughout the country. All samples were analyzed to designate both gross alpha and gross beta radioactivities and the radionuclides’ concentrations. The gross alpha radioactivities were measured as below 1 Bq kg-1 in most of the samples, some of them being due to the detection limit of the counting system. The gross beta radioactivity levels ranged from 1.8 Bq kg-1 to 453 Bq kg-1, larger levels being observed in leguminous seeds while the highest level being in haricot bean. The concentrations of natural radionuclides in the foodstuffs were investigated by the method of gamma spectroscopy. High levels of 40K were measured in all the samples, the highest activities being again in leguminous seeds. Low concentrations of 238U and 226Ra were found in some of the samples, which are comparable to the reported results in the literature. Based on the activity concentrations obtained in this study, average annual effective dose equivalents for the radionuclides 226Ra, 238U, and 40K were calculated as 77.416 µSv y-1, 0.978 µSv y-1, and 140.55 µSv y-1, respectively.
Degradation of Endosulfan in Different Soils by Indigenous and Adapted Microorganisms
The environmental fate of organic contaminants in soils is influenced significantly by the pH, texture of soil, water content and also presence of organic matter. In this study, biodegradation of endosulfan isomers was studied in two different soils (Soil A and Soil B) that have contrasting properties in terms of their texture, pH, organic content, etc. Two Nocardia sp., which were isolated from soil, were used for degradation of endosulfan. Soils were contaminated with commercial endosulfan. Six sets were maintained from two different soils, contaminated with different endosulfan concentrations for degradation experiments. Inoculated and uninoculated mineral media with Nocardia isolates were added to the soils and mixed. Soils were incubated at a certain temperature (30 °C) during ten weeks. Residue endosulfan and its metabolites’ concentrations were determined weekly during the incubation period. The changes of the soil microorganisms were investigated weekly.
Estimation Model for Concrete Slump Recovery by Using Superplasticizer
This paper aimed to introduce the solution of concrete
slump recovery using chemical admixture type-F (superplasticizer,
naphthalene base) to the practice in order to solve unusable concrete
problem due to concrete loss its slump, especially for those tropical
countries that have faster slump loss rate. In the other hand, randomly
adding superplasticizer into concrete can cause concrete to segregate.
Therefore, this paper also develops the estimation model used to
calculate amount of second dose of superplasticizer need for concrete
slump recovery. Fresh properties of ordinary Portland cement
concrete with volumetric ratio of paste to void between aggregate
(paste content) of 1.1-1.3 with water-cement ratio zone of 0.30 to
0.67 and initial superplasticizer (naphthalene base) of 0.25%-1.6%
were tested for initial slump and slump loss for every 30 minutes for
one and half hour by slump cone test. Those concretes with slump
loss range from 10% to 90% were re-dosed and successfully
recovered back to its initial slump. Slump after re-dosed was tested
by slump cone test. From the result, it has been concluded that, slump
loss was slower for those mix with high initial dose of
superplasticizer due to addition of superplasticizer will disturb
cement hydration. The required second dose of superplasticizer was
affected by two major parameters, which were water-cement ratio
and paste content, where lower water-cement ratio and paste content
cause an increase in require second dose of superplasticizer. The
amount of second dose of superplasticizer is higher as the solid
content within the system is increase, solid can be either from cement
particles or aggregate. The data was analyzed to form an equation use
to estimate the amount of second dosage requirement of
superplasticizer to recovery slump to its original.
Study on Compressive Strength and Setting Times of Fly Ash Concrete after Slump Recovery Using Superplasticizer
Fresh concrete has one of dynamic properties known
as slump. Slump of concrete is design to compatible with placing
method. Due to hydration reaction of cement, the slump of concrete
is loss through time. Therefore, delayed concrete probably get reject
because slump is unacceptable. In order to recover the slump of
delayed concrete the second dose of superplasticizer (naphthalene
based type F) is added into the system, the slump recovery can be
done as long as the concrete is not setting. By adding superplasticizer
as solution for recover unusable slump loss concrete may affects
other concrete properties. Therefore, this paper was observed setting
times and compressive strength of concrete after being re-dose with
chemical admixture type F (superplasticizer, naphthalene based) for
slump recovery. The concrete used in this study was fly ash concrete
with fly ash replacement of 0%, 30% and 50% respectively. Concrete
mix designed for test specimen was prepared with paste content (ratio
of volume of cement to volume of void in the aggregate) of 1.2 and
1.3, water-to-binder ratio (w/b) range of 0.3 to 0.58, initial dose of
superplasticizer (SP) range from 0.5 to 1.6%. The setting times of
concrete were tested both before and after re-dosed with different
amount of second dose and time of dosing. The research was
concluded that addition of second dose of superplasticizer would
increase both initial and final setting times accordingly to dosage of
addition. As for fly ash concrete, the prolongation effect was higher
as the replacement of fly ash increase. The prolongation effect can
reach up to maximum about 4 hours. In case of compressive strength,
the re-dosed concrete has strength fluctuation within acceptable range
The Clinical Use of Ahmed Valve Implant as an Aqueous Shunt for Control of Uveitic Glaucoma in Dogs
Objective: Safety and efficacy of Ahmed glaucoma
valve implantation for the management of uveitis induced glaucoma
evaluated on the five dogs with uncontrollable glaucoma. Materials
and Methods: Ahmed Glaucoma Valve (AGV®; New World
Medical, Rancho Cucamonga, CA, USA) is a flow restrictive, nonobstructive
self-regulating valve system. Preoperative ocular
evaluation included direct ophthalmoscopy and measurement of the
intraocular pressure (IOP). The implant was examined and primed
prior to implantation. The selected site of the valve implantation was
the superior quadrant between the superior and lateral rectus muscles.
A fornix-based incision was made through the conjunectiva and
Tenon’s capsule. A pocket is formed by blunt dissection of Tenon’s
capsule from the episclera. The body of the implant was inserted into
the pocket with the leading edge of the device around 8-10 mm from
the limbus. Results: No post-operative complications were detected
in the operated eyes except a persistent corneal edema occupied the
upper half of the cornea in one case. Hyphaema was very mild and
seen only in two cases which resolved quickly two days after surgery.
Endoscopical evaluation for the operated eyes revealed a normal
ocular fundus with clearly visible optic papilla, tapetum and retinal
blood vessels. No evidence of hemorrhage, infection, adhesions or
retinal abnormalities was detected. Conclusion: Ahmed glaucoma
valve is safe and effective implant for treatment of uveitic glaucoma
Screening for Larvicidal Activity of Aqueous and Ethanolic Extracts of Fourteen Selected Plants and Formulation of a Larvicide against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) Larvae
This study aims to: a) obtain ethanolic (95% EtOH) and aqueous extracts of Selaginella elmeri, Christella dentata, Elatostema sinnatum, Curculigo capitulata, Euphorbia hirta, Murraya koenigii, Alpinia speciosa, Cymbopogon citratus, Eucalyptus globulus, Jatropha curcas, Psidium guajava, Gliricidia sepium, Ixora coccinea and Capsicum frutescens and screen them for larvicidal activities against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) larvae; b) to fractionate the most active extract and determine the most active fraction; c) to determine the larvicidal properties of the most active extract and fraction against by computing their percentage mortality, LC50, and LC90 after 24 and 48 hours of exposure; and d) to determine the nature of the components of the active extracts and fractions using phytochemical screening. Ethanolic (95% EtOH) and aqueous extracts of the selected plants will be screened for potential larvicidal activity against Ae. aegypti and Ae. albopictus using standard procedures and 1% malathion and a Piper nigrum based ovicide-larvicide by the Department of Science and Technology as positive controls. The results were analyzed using One-Way ANOVA with Tukey’s and Dunnett’s test. The most active extract will be subjected to partial fractionation using normal-phase column chromatography, and the fractions subsequently screened to determine the most active fraction. The most active extract and fraction were subjected to dose-response assay and probit analysis to determine the LC50 and LC90 after 24 and 48 hours of exposure. The active extracts and fractions will be screened for phytochemical content. The ethanolic extracts of C. citratus, E. hirta, I. coccinea, G. sepium, M. koenigii, E globulus, J. curcas and C. frutescens exhibited significant larvicidal activity, with C. frutescens being the most active. After fractionation, the ethyl acetate fraction was found to be the most active. Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, indoles and steroids. A formulation using talcum powder–300 mg fraction per 1 g talcum powder–was made and again tested for larvicidal activity. At 2 g/L, the formulation proved effective in killing all of the test larvae after 24 hours.
CT Medical Images Denoising Based on New Wavelet Thresholding Compared with Curvelet and Contourlet
One of the most important challenging factors in
medical images is nominated as noise. Image denoising refers to the
improvement of a digital medical image that has been infected by
Additive White Gaussian Noise (AWGN). The digital medical image
or video can be affected by different types of noises. They are
impulse noise, Poisson noise and AWGN. Computed tomography
(CT) images are subjects to low quality due to the noise. Quality of
CT images is dependent on absorbed dose to patients directly in such
a way that increase in absorbed radiation, consequently absorbed
dose to patients (ADP), enhances the CT images quality. In this
manner, noise reduction techniques on purpose of images quality
enhancement exposing no excess radiation to patients is one the
challenging problems for CT images processing. In this work, noise
reduction in CT images was performed using two different
directional 2 dimensional (2D) transformations; i.e., Curvelet and
Contourlet and Discrete Wavelet Transform (DWT) thresholding
methods of BayesShrink and AdaptShrink, compared to each other
and we proposed a new threshold in wavelet domain for not only
noise reduction but also edge retaining, consequently the proposed
method retains the modified coefficients significantly that result good
visual quality. Data evaluations were accomplished by using two
criterions; namely, peak signal to noise ratio (PSNR) and Structure
Human Absorbed Dose Estimation of a New IN-111 Imaging Agent Based on Rat Data
The measurement of organ radiation exposure dose is
one of the most important steps to be taken initially, for developing a
new radiopharmaceutical. In this study, the dosimetric studies of a
novel agent for SPECT-imaging of the bone metastasis, 111In-
1,4,7,10-tetraazacyclododecane-1,4,7,10 tetraethylene phosphonic
acid (111In-DOTMP) complex, have been carried out to estimate the
dose in human organs based on the data derived from rats. The
radiolabeled complex was prepared with high radiochemical purity in
the optimal conditions. Biodistribution studies of the complex was
investigated in the male Syrian rats at selected times after injection
(2, 4, 24 and 48 h). The human absorbed dose estimation of the
complex was made based on data derived from the rats by the
radiation absorbed dose assessment resource (RADAR) method.
111In-DOTMP complex was prepared with high radiochemical purity
of >99% (ITLC). Total body effective absorbed dose for 111In-
DOTMP was 0.061 mSv/MBq. This value is comparable to the other
111In clinically used complexes. The results show that the dose with
respect to the critical organs is satisfactory within the acceptable
range for diagnostic nuclear medicine procedures. Generally, 111In-
DOTMP has interesting characteristics and can be considered as a
viable agent for SPECT-imaging of the bone metastasis in the near
Design, Construction and Performance Evaluation of a HPGe Detector Shield
A multilayer passive shield composed of low-activity
lead (Pb), copper (Cu), tin (Sn) and iron (Fe) was designed and
manufactured for a coaxial HPGe detector placed at a surface
laboratory for reducing background radiation and radiation dose to
the personnel. The performance of the shield was evaluated and
efficiency curves of the detector were plotted by using of various
standard sources in different distances. Monte Carlo simulations and
a set of TLD chips were used for dose estimation in two distances of
20 and 40 cm. The results show that the shield reduced background
spectrum and the personnel dose more than 95%.
Preliminary Dosimetric Evaluation of a New Therapeutic 177Lu Complex for Human Based on Biodistribution Data in Rats
Abstract—[Tris (1,10-phenanthroline) lanthanum(III)]
trithiocyanate is a new compound that has shown high ability for
stopping the synthesis of DNA and also acting as a photosensitizer.
Nowadays, the radiation dose assessment resource (RADAR) method
is known as the most common method for absorbed dose calculation.
177Lu was produced by (n, gamma) reaction in a research reactor.
177Lu-PL3 was prepared in the optimized condition. The
radiochemical yield was checked by ITLC method. The
biodistribution of the complex was investigated by intravenously
injection to wild-type rats via their tail veins. In this study, the
absorbed dose of 177Lu-PL3 to human organs was estimated by
RADAR method. 177Lu was prepared with a specific activity of 2.6-3
GBq.mg-1 and radionuclide purity of 99.98 %. Final preparation of
the radiolabelled complex showed high radiochemical purity of >
99%. The results show that liver and spleen have received the highest
absorbed dose of 1.051 and 0.441 mSv/MBq, respectively. The
absorbed dose values for these two dose-limiting tissues suggest
more biological studies special in tumor-bearing animals.
Estimated Human Absorbed Dose of 111In-BPAMD as a New Bone-Seeking SPECT-Imaging Agent
An early diagnosis of bone metastasis is very
important for making a right decision on a subsequent therapy. One
of the most important steps to be taken initially, for developing a new
radiopharmaceutical is the measurement of organ radiation exposure
dose. In this study, the dosimetric studies of a novel agent for
SPECT-imaging of the bone metastasis, 111In-(4-
-1,4,7,10-tetraazacyclododec-1-yl) acetic acid (111In-BPAMD)
complex, have been carried out to estimate the dose in human organs
based on the data derived from mice. The radiolabeled complex was
prepared with high radiochemical purity in the optimal conditions.
Biodistribution studies of the complex was investigated in the male
Syrian mice at the selected times after injection (2, 4, 24 and 48 h).
The human absorbed dose estimation of the complex was made based
on data derived from the mice by the radiation absorbed dose
assessment resource (RADAR) method. 111In-BPAMD complex was prepared with high radiochemical
purity >95% (ITLC) and specific activities of 2.85 TBq/mmol. Total
body effective absorbed dose for 111In-BPAMD was 0.205
mSv/MBq. This value is comparable to the other 111In clinically used
complexes. The results show that the dose with respect to the critical
organs is satisfactory within the acceptable range for diagnostic
nuclear medicine procedures. Generally, 111In-BPAMD has
interesting characteristics and it can be considered as a viable agent
for SPECT-imaging of the bone metastasis in the near future.