Dose Evaluation of Head and Neck Cancer IMRT Treatment Planning Based on Gamma Index Analysis of Varian Halcyon 2.0 Linac

Varian Halcyon 2.0 linear accelerator was launched and became available for clinical use in 2018. Therefore, it is necessary to evaluate the accuracy of exit fluence of the Halcyon 2.0 for quality assurance (QA) of head and neck cancer treatment planning, pretreatment, and treatment. The accuracy of the exit fluence for twenty treatment plannings has been evaluated by conducting gamma analysis for QA pretreatment and treatment in each field and composite field by using criteria for gamma index 3 %/3 mm and 2 %/2 mm. The QA pretreatment results are in the average value for each criterion for each field and composite fields on actual gantry angle and null gantry angle with gamma passing rate (GPR) of over 99 % (range 99.78 %-99.95 %) The total treatments consisted of 2717 fractions. The analysis results of GPR for fields were 99.32 % and 97.74 % for gamma indexes of 3 %/3 mm and 2 %/2 mm, respectively. In addition, the analysis results of GPR for composites were 95.46 % and 81.38 % for gamma indexes of 3 %/3 mm and 2 %/2 mm, respectively. Based on this result, the average GPRs of QA pretreatment are ≈ 99 % of the total pixels. This means the prediction dose of Varian Halcyon 2.0 is accurate. The average GPRs of treatment is nearly  90 %, showing that Varian Halcyon 2.0 is effective for creating treatment plans for complex cases

Bone histomorphometric study of young rats following oestrogen deficiency

Osteoporosis is a global problem which results in increased fractures risk. The reports from earlier studies were inconsistent with the aging factor as well as the time which is needed to induce bone loss post-ovariectomy. This study aimed to determine the short-term effects of estrogen deficiency on bone structural histomorphometric parameters in young rats. 30 Sprague-Dawley female rats weighing 250 to 300 g were assigned to baseline, sham-operated and ovariectomy groups. The baseline group (n = 10) was sacrificed immediately. Sham-operated rats (SO, n = 10) underwent sham operation while ovariectomised group (OVX, n =10) underwent bilateral ovariectomy. All the rats were sacrificed 6 weeks post-ovariectomy. Following sacrifice, the right femora were dissected and subjected to the histomorphometric analysis using modified Von Kossa method. Bone volume/tissue volume (BV/TV) and trabecular number (Tb.N) reduced significantly, while trabecular separation (Tb.Sp) increased significantly in the ovariectomized rats, compared to the baseline and sham groups 6 weeks postovariectomy (P<0.001). In the other hand, trabecular thickness (Tb.Th) was consistent among the groups (P=0.41). Estrogen deficiency resulted in marked decline in BV/TV which most probably attributed to a reduction in Tb.N. In contrast, Tb.Th was found to be preserved following estrogen loss. Hence, the period of 6 weeks post-ovariectomy was sufficient to induce osteoporosis in ovariectomized rats without affecting Tb.Th.Key words: Bone histomorphometry, menopause, estrogen deficiency, osteoporosis, ovariectomy, trabecular bone

Aligning cloud computing security with business strategy

These days, the technological growth in the IT sector is rapid. Cloud computing is also one of the new technologies that have both benefits and limitations. This paper gives an overview of how cloud computing can be helpful for an enterprise. It emphasizes on how cloud computing can be adopted in the IT sector. The paper also discusses the security issues of cloud computing. This article also highlights the issue of data leakage in this technology which faces cloud computing clients. The authors have designed a model to solve this issue through data isolation. A business value will be achieved through the proposed model by aligning the cloud computing security with the business strategy and increase the security procedures to verify the authenticated users through the virtual system

Properties of resin impregnated oil palm wood (Elaeis Guineensis Jack)

Oil palm wood (OPW) was treated with medium-molecular weight PF resin (mmw-PF) through a modified impregnation-compression method. The method consists of four steps, namely, drying, impregnation, heating, and hot pressing densification. The objective of the study was to optimize the impregnation variables. The overall density of the OPW increased, whereas the density gradient between the two OPW structural elements (namely, parenchyma tissues and vascular bundles) decreased. The weight percent gain (WPG) significantly increased even with a very short impregnation period (i.e. 1 hour). Young`s Modulus of the compression parallel to the grain increased by 15 times (from 170 to 2600 MPa) and the shear strength increased by 7 times (from 1.9 to 13 MPa). The strength of the samples was increased exponentially against density increment. The treatment also made the two OPW structural elements to be strongly bonded that helped in enhancing the durability and machining characteristics of the material

A study of frequency and pulses for stepper motor controller system by using programmable logic controller

The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load

Isolation and characterization of polyhydroxyalkanoates (PHAS) producing bacteria from brackish stream

Polyhydroxyalkanoates (PHAs) are biopolymers which have similar characteristics with petrochemical plastics but a step better due to its biodegradable property. A total of 23 strains were isolated from two different brackish sources. In order to detect the PHAs granules, the PHAs producing bacteria were first screened with Sudan Black B staining. Twenty strains were observed with lipid granules and were subjected to further confirmation with Nile blue staining. From the Nile blue staining, only 10 strains have the ability in producing PHAs and 2 were identified as strong PHAs producers. This study focuses on the 2 strains named S1 and L1. Further identification procedure was carried out and found that strain S1 and L1 belongs to Pseudomonas sp. L1 strain was found to be promising for PHAs production since it accumulated PHAs for about 88.3%. The PHAs produced by this strain was analyzed using Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) analysis and was identified as poly-3-hydroxybutyrate (P-3HB)

Validation of a virtual patient and virtual trials method for accurate prediction of tight glycemic control protocol performance

Peer reviewe

Indoor Radon Concentration Measurement in Selected Factories in Northern and Central Iraq

In this work, the outdoor radon concentration level and lung cancer risks have been measured in selected locations in northern and central Iraq during the summer season 2012 by using time integrated passive radon dosimeters containing LR-115 Type II plastic track detectors. These measurements were carried out in the factories for an exposure time of 60 day. The radon concentration in these factories ranges from (36.36 – 125.10) Bq.m-3 with an average of (59.93Bq.m-3), which within the acceptable radon levels (50-150) Bq.m-3 recommended by the International Commission on Radiological Protection (ICRP). The average absorption effective dose equivalent for a person living in factories for which the investigation were done was found to be (1.425mSv.y-1). It is observed that the average lung cancer per year per 106 person was found to be 25.654. Keyword: LR-115 Type II nuclear track detectors; Radon concentration; AEDE; PAEC