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Background: The use of boluses for radiation therapy is very necessary to overcome the problem of sending inhomogeneous doses in the target volume due to irregularities on the surface of the skin. The bolus materials for radiation therapy need to be evaluated. Objective: The present study aims to evaluate some handmade boluses for megavoltage electron and photon radiation therapy. Several dosimetric properties of the synthesized boluses, including relative electron density (RED), transmission factor, mass attenuation coefficient, percentage depth dose (PDD), and percentage surface dose (PSD) were investigated. Material and Methods: In this experimental study, we evaluated natural rubber, silicone rubber mixed either with aluminum or bismuth, paraffin wax, red plasticine, and play-doh as soft tissue equivalent. CT-simulator, in combination with ECLIPSE software, was used to determine bolus density. Meanwhile, Linear Accelerator (Linac) Clinac iX (Varian Medical Systems, Palo Alto), solid water phantom, and Farmer ionization chamber were used to measure and analyze of dosimetric properties. Results: The RED result analysis has proven that all synthesized boluses are equivalent to the density of soft tissue such as fat, breast, lung, and liver. The dosimetric evaluation also shows that all synthesized boluses have a density similar to the density of water and can increase the surface dose with a value ranging from 6-20% for electron energy and 30-50% for photon energy. Conclusion: In general, all synthesized boluses have an excellent opportunity to be used as an alternative tissue substitute in the surface area of the body when using megavoltage electron and photon energy.

Blood cancer causes a significant increase in the concentration of Leukocytes, which can be broken down through dielectrophoresis and electrochemical procedures. Therefore, the electric field plays an important role in the migration of leukocytes to high voltage areas. This is because different electrode arrangements produce varying electric field distributions. Furthermore, this study applied finite element methods to generate electric fields when electrodes with an AC voltage were applied to blood placed in a chamber. Therefore, in this study, variations of mediums and electrode arrangements were investigated, which led to the recommendation of 3 models. The objective was to investigate electrode arrangements that produce optimal electric field distribution for the three models to exhibit a booster of electric field distribution. The maximum electric field is generated close to the electrode (Z=2 mm and Z=92 mm) for any material (i.e. normal blood, B lymphocyte, and T lymphocyte) with values of 22.6 V/m and 23.47 V/m, 22.85 V/m and 22.97 V/m, and 24.88 V/m and 25.01 V/m. Based on principle, lymphocytes in the blood result in positive dielectrophoresis, since they migrate to a higher electric field close to the electrode, with enough input voltage to turn the electrochemical process on the leukocytes into electric current. Furthermore, this study provides new perspectives and ideas, which have not been revealed in previous studies on blood cancer therapy using the electric field of Ag electrode in blood cancer distribution.Keywords: blood cancer, dielectrophoresis, electric field, voltage, electrochemical, and cancer therapy.

The delivery of radiation therapy to patients requires prior planning made by medical physicists to achieve radiotherapy goals. Radiotherapy has a plan to eradicate the growth of cancer cells by giving high doses and minimizing the radiation dose to normal tissue. Evaluation of planning is generally done based on dosimetric parameters, such as minimum dose, maximum dose, and means dose obtained from the DVHs data. Based on the same DVHs, data were evaluate dinterms of biological effects to determine the highest possible toxicity in normal tissue after the tumor had been treated with radiation using the NTCP model. The evaluation was conducted by selecting three DICOM-RT data of post-mastectomy right breast cancer patients who had been prescribed a dose of 50 Gy obtained from the Hospital MRCCC Siloam Semanggi database. All data were processed using open-source software DICOManTX to get the DVH and isodose information. Matlab-based CERR software was used to calculate the NTCP model. The results show that the three patients' DVH and isodose treatment planning result in a homogeneous dose distribution result because the PTV area obtains adose limit of ≥ 95%. Moreover, normalt issue still gets adose below the tolerance limit based on the standard from RTOG 1005 and ICRU 83. Analysis of NTCP shows a complication probability below 1% for each organ, suggesting that any organ which has been irradiated has a low likelihood of complications. Therefore, it can be concluded that the treatment planning which has been made in the three patients using the IMRT technique has achieved the objectives of radiotherapy, which is to minimize toxicity to healthy organs. |Keywords: DVH, isodose, NTCP, radiotherapy.

Electrocardiography is a process or method to observe and record the activity of the heart by using a graph of electrical voltage versus time. A standard plan to achieve this is by measuring the bioelectric potential or bioimpedance of the heart organ. In this research, an electrical impedance cardiography device will be designed and tested. The process is carried out by using four electrodes that are attached at the neck and the diaphragm level of the body, an electric current with a specific value and frequency, then injected on a pair of electrodes, and the voltage will be measured on other pair of electrodes. The device testing process is carried out on subjects in good health and having no medical abnormality in a sitting and upright position. Impedance data will be measured and recorded at each time; the data that has been obtained will then be processed to determine the impedance graph Z and the first derivative of Z (dZ/dt). The number of heartbeats will also be calculated each time with another method, which is by using a stopwatch to compare the validity of the heart rate readings from the impedance cardiography device. The result demonstrated that the electrical impedance cardiography device that has been made could be used to illustrate heart rate graphs as a result of cardiovascular activity

Treatment planning aimed to provide the maximum dose to target tumor and minimize doses received by healthy tissue. Dose-volume histograms contain essential information about the dose distribution that radiation oncologists use in considering a treatment planning. In breast cancer mastectomy, the thickness of the thorax wall has decreased because of surgery. Therefore it is necessary to analyze the dose received by healthy tissue around the tumor. This study analyzes the doses distribution in breast cancer mastectomy using SlicerRT and compares it with treatment planning from the hospital. The study used three data patients from MRCCC Siloam Hospitals Jakarta. The simulation results were analyzed based on the International Commission on Radiation Units and Measurements Report’s 83 for target tumor and tolerance limits of healthy tissue according to limitations from various references. Although the target tumor’s homogeneity does not qualify, the healthy tissue around the tumor is still within tolerance. It is not a problem in intensity-modulated radiation therapy if avoidance of healthy tissue is more important than homogeneity. For the comparison result, the percentage acceptance of SlicerRT simulation is quite good, above 90%.

Lung cancer has decreased mortality rates each year that can treat with radiotherapy. The radiotherapy module is own by 3D Slicer that is open-source software. The purpose is to determine the distribution of doses on the dose-volume histogram (DVH) and the percentage of the suitability of the 3D Slicer simulation results with the Treatment Planning System (TPS) at MRCCC Siloam Hospital. The data used were three Computed Tomographic images of lung cancer patients obtained from the MRCCC Siloam Hospital. The parameters analyzed included volume, the dose of the target volume, and organ at risk (OAR). Analytical studies were carried out by comparing the target volume with The International Commission on Radiation Unit (ICRU) Report 83 and comparing the OAR regarding dose tolerance. The dose distribution of all patients from the simulated 3D slicer for OAR met the tolerance limit reference recommendations. The Planning Target Volume (PTV) of all patients also matched the evaluation recommended by the ICRU Report 83. The percentage value of the suitability between the 3D Slicer and TPS results for all patients was above 95%. It shows that 3D Slicer can use as a recommendation software for initial radiotherapy planning studies.

The success indicator of radiotherapy planning is that it can deliver a precise and maximum dose to the tumor, and at the same time, health tissues receive a minimum dose. The success can be achieved by understanding the density of the organs that go into the treatment beams because the dose distribution was directly affected by tissue inhomogeneity. Therefore, the study aimed to evaluate the tissue density of DICOM images and the homogeneity of the distribution of dose from treatment planning in lung cancer using 3D Slicer-SlicerRT. The method used in the study was used 3 data of CT and RT – Structures data from The Cancer Imaging Archive (TCIA), NSCLC-Radiomics with a diagnosis of stage IIIB squamous cell carcinoma, the location of right cancer, and only one nodule. The calculation of tissue density values using segment statistics in 3D Slicer was based on CT-DICOM information. While the treatment planning was built using 3D Slicer-SlicerRT with a prescription of 60 Gy/30 fractions. Treatment design used six fields, and optimization was done by combining a gantry angle and beam weight. The results represented that the calculation of tissue density was following the reference standard and relative electron density for each organ. Besides, the study had successfully designed a treatment planning system using 3D Slicer-SlicerRT that fulfilled the total dose standard, was excellent for OAR sparing, and had a homogeneity index for patient data ID 1 until 4 with values of 0.252, 0.009, 0.007, and 0.007, respectively.

The bolus is also known a tissue compensation that has material similar to body tissue and placed directly onto the skin surface for radiation therapy. This study aims to characterize and evaluate the synthesized homemade bolus using Natural Rubber, Paraffin Candle, Play-Doh, and Paraffin Wax Pure for radiation therapy using a photon beam. Several dosimetry properties of the synthesized of the bolus, including relative electron density (RED), transmission factor, attenuation coefficient, and percentage of surface dose (PSD), were investigated. All the synthesized bolus made with the same dimension of 11×11 cm2 with the thickness is 1 cm. CT-Scan was used to measure relative electron density (RED) where as LINAC 2300iX with energies 6 and 10 MV were used to evaluate percentage of surface dose. The RED value of all bolus material is in accordance with the provisions of bolus as a tissue compensation of the human body, which is almost the same as the value of HU in breast organs, skin, fat and adult bones. Large transmission factors and attenuation coefficients of each bolus correspond to bolus from paraffin candles as the default bolus of the hospital. The maximum bolus dose value increases when compared to measurements without bolus.

Carbon electrodes have been successfully synthesized and characterized for desalination system based on Capacitive Deionization (CDI) technology. The carbon electrodes were synthesized with an activated carbon (700 – 1400 m2/g), carbon black, glutaric acid and polyvinyl alcohol as a binder using cross-linking method at 120 °C. The study was to investigate salt removal percentage value of 0.1 M NaCl, MgCl and KCl using CDI cell. A solution with 0.1 M was supplied to the cell using a Boyu Submersible pump (model SP-601) at a flow rate of 10 mL/min. When potentials of 1.0, 2.0, and 3.0 V were applied to the CDI cell, the result showed that a solution of 0.1 M KCl has greater salt-removal percentage than the solutions with 0.1 M NaCl and MgCl. The salt-removal percentage of KCl was achieved at 55% for 3.0 V whilst resulted in 20 and 30% for NaCl and MgCl, respectively.

Carbon electrodes prepared with crosslink method for desalination purpose has been synthesized and characterized. The carbon electrodes were synthesized with activated carbon (700 – 1400 m2/g) and polyvinyl alcohol (PVA) as a binder using crosslink method with temperature crosslink at 120°C. Electrochemical properties of carbon electrodes were examined using electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The proposed study was to measure the salt-removal percentage of 330 µS/cm NaCl using a capacitive deionization (CDI) unit cell prepared with two pairs of carbon electrodes. The applied potential of 2.0 V and a flow rate of 25 mL/min were used to desalination tests. The result showed that the greatest value of the percentage of salt-removal was achieved at 36.1% for the carbon electrodes with Active Carbon Modified (ACM) while the salt-removal percentage for the Active Carbon (AC) electrodes only at 22%. The fact indicates that the active carbon modified using HNO3 can improve the ef...

Carbon electrodes for desalination purpose have been successfully synthesized using activated carbon powder (BET surface area=700 – 1400 m2/g), carbon black and polyvinyl alcohol (PVA) binder by cross-linking method with glutaric acid (GA) at 120 °C. The electrochemical properties of the carbon electrodes were analyzed using electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) whilst the physical properties were observed with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). In order to assess the desalting performance, salt removal experiments were performed by constructing a capacitive deionization unit cell with five pairs of carbon electrodes. For each pair consisted of two parallel carbon electrodes separated by a spacer. Desalination and regeneration processes were also observed in the salt-removal experiments. The salt-removal experiments were carried out in single-pass mode using a solution with 0.1 M NaCl at a flow rate of 10 mL/min. A voltage of 3 V...

Carbon electrodes prepared with freezing thawing method for desalination purpose has been synthesized and characterized. The carbon electrodes were prepared with an activated carbon (700 – 1400 m2/g) and polyvinyl alcohol (PVA) as a binder using freezing thawing method with 3 and 4 cycles (1 cycle is 12 hours for freezing and 12 hours for thawing). Electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to analyze their electrochemical properties. The main study was to measure the salt-removal of 180 µS/cm NaCl, MgCl and KCl using a capacitive deionization (CDI) unit cell with five pairs of carbon electrodes. The applied potential of 2.0 V and a flow rate of 25 mL/min were used to desalination tests, the result showed that the salt-removal percentage of KCl solution has greater than NaCl and MgCl. The highest value for the salt-removal of NaCl, KCl and MgCl can be achieved for the freezing thawing method with 4 cycles. The salt-removal percentage of KCl was achieved at 64.10% whilst ...

Ion-exchange membrane technology has shown a great potential to enhance the desalting efficiency. Ion-exchange membranes are placed in front of the electrodes so that the charged ions can be selectively passed through the membrane layer and captured by the oppositely charged electrode more quickly, so as to increase the efficiency of desalination. In this research, carbon electrodes have been synthesized from an activated carbon (700 – 1400 m2/g) and polyvinyl alcohol (PVA) as a binder using freezing thawing method. A solution with 180 µS/cm NaCl was pumped to the capacitive deionization (CDI) cell using a Boyu Submersible pump (model SP-601) at a flow rate of 25 mL/min and the voltage was set at 2 V. The result showed that the CDI cell with ion-exchange membrane (MCDI) has the salt removal efficiency greater than the CDI cell without ion-exchange membrane. The salt-removal percentage of MCDI was achieved at 66.36%, meanwhile the CDI cell without ion-exchange membrane resulted in 54.4%.

Attachment of bacteria to surfaces and subsequent biofilm formation remains a major cause of cross-contamination capable of inducing both food-related illness and nosocomial infections. Resistance to many current disinfection technologies means facilitating their removal is often difficult. The aim of this study was to investigate the efficacy of 405 nm light for inactivation of bacterial attached as biofilms to glass and acrylic. Escherichia coli biofilms (10(3)-10(8) CFU mL(-1)) were generated on glass and acrylic surfaces and exposed for increasing times to 405 nm light (5-60 min) at ca 140 mW cm(-2). Successful inactivation of biofilms has been demonstrated, with results highlighting complete/near-complete inactivation (up to 5 log10 reduction on acrylic and 7 log10 on glass). Results also highlight that inactivation of bacterial biofilms could be achieved whether the biofilm was on the upper "directly exposed" surface or "indirectly exposed" underside surface. Statistically significant inactivation was also shown with a range of other microorganisms associated with biofilm formation (Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes). Results from this study have demonstrated significant inactivation of bacteria ranging from monolayers to densely populated biofilms using 405 nm light, highlighting that with further development this technology may have potential applications for biofilm decontamination in food and clinical settings.

The antimicrobial properties of light is an area of increasing interest. This study investigates the sensitivity of the significant foodborne pathogen Listeria monocytogenes to selected wavelengths of visible light. Results demonstrate that exposure to wavelength region 400-450 nm, at sufficiently high dose levels (750 J cm(-2)), induced complete inactivation of a 5 log(10) population. Exposure to wavelengths longer than 450 nm did not cause significant inactivation. Analysis of 10 nm bandwidths between 400 and 450 nm confirmed 405(± 5) nm light to be most effective for the inactivation of L. monocytogenes, with a lesser bactericidal effect also evident at other wavelengths between 400 and 440 nm. Identification of the optimum bactericidal wavelength enabled the comparison of inactivation using 405(± 5) nm filtered light and a 405 nm light-emitting diode (LED) array (14 nm FWHM). Results demonstrate similar inactivation kinetics, indicating that the applied dose of 405 nm light is the important factor. Use of the 405 nm LED array for the inactivation of L. monocytogenes and other Listeria species resulted in similar kinetics, with up to 5 log(10) reductions with a dose of 185 J cm(-2). Comparative data for the 405 nm light inactivation of L. monocytogenes and other important foodborne pathogens, Escherichia coli, Salmonella enteritidis and Shigella sonnei, are also presented, with L. monocytogenes showing higher susceptibility to inactivation through 405 nm light exposure.

The bactericidal effect of 405 nm light was investigated on taxonomically diverse bacterial pathogens from the generaSalmonella, Shigella, Escherichia, Listeria, and Mycobacterium. High-intensity 405 nm light, generated from an array of 405-nm light-emitting diodes (LEDs), was used to inactivate bacteria in liquid suspension and on exposed surfaces.L. monocytogeneswas most readily inactivated in suspension, whereasS. entericawas most resistant. In surface exposure tests,L. monocytogeneswas more susceptible than Gram-negative enteric bacteria to 405 nm light when exposed on an agar surface but interestingly less susceptible thanS. entericaafter drying onto PVC and acrylic surfaces. The study findings, that 405 nm light inactivates diverse types of bacteria in liquids and on surfaces, in addition to the safety advantages of this visible (non-UV wavelength) light, indicate the potential of this technology for a range of decontamination applications.

Carbon electrodes for desalination system have successfully been synthesized with and/or without modified activated carbon by chemically activated using HNO3. The freezing-thawing method was used to synthesize the carbon electrodes. In this study, 5 cycles of freezing-thawing were applied in the synthesized carbon electrodes (1 cycle is 12 hours for freezing and 6 hours for thawing). Electrochemical properties of the synthesized carbon electrodes with and/or without modified activated carbon were characterized and observed by cyclic voltammetry (CV) and Electrical impedance spectroscopy (EIS). The salt-removal percentage experiments were conducted to evaluate the performance of capacitive deionization (CDI) cell using the two pairs of carbon electrodes with each pair consisting of two parallel electrodes that separated by a spacer. The result showed that the salt removal percentage of the carbon electrodes with modified activated carbon has greater than the carbon electrodes without modified activated carbon, with reduction level at 55.7 and 24.8%, respectively.