Boron Dose Research Articles

Assessing the biological effects of boron neutron capture therapy through cellular DNA damage repair model.

Boron neutron capture therapy (BNCT) is a targeted radiotherapy that relies on the 10B (n, α) 7Li reaction, which produces secondary particles with high linear energy transfer (LET), leading to a high relative biological effectiveness (RBE) in tumors. The biological effectiveness of BNCT is influenced by factors such as boron distribution and concentration, necessitating improved methods for assessing its radiobiological effects and clarifying the sensitivity of the differences in different factors to the biological effects. This paper introduces a method to evaluate the biological effects of BNCT using the cellular repair model. This method aims to overcome some of the limitations of current evaluation approaches. The primary goal is to provide guidance for clinical treatments and the development of boron drugs, as well as to investigate the impact of the synergistic effects of mixed radiation fields in BNCT on treatment outcomes. The approach involves three key steps: first, extending the radial energy deposition distribution of BNCT secondary particles using Geant4-DNA. This allows for the calculation of initial DNA double-strand breaks (DSBs) distributions for a given absorbed dose. Next, the obtained initial DSB distributions are used for DNA damage repair simulations to generate cell survival curves, then thereby quantifying RBE and compound biological effectiveness (CBE). The study also explores the synergistic effects of the mixed radiation fields in BNCT on assessing biological effects were also explored in depth. The results showed that the RBE of boronophenylalanine (BPA) and sodium borocaptate (BSH) drugs at cell survival fraction 0.01 was 2.50 and 2.15, respectively. The CBE of the boron dose component was 3.60 and 0.73, respectively, and the RBE of the proton component was 3.21, demonstrating that BPA has a significantly higher biological impact than BSH due to superior cellular permeability. The proton dose significance in BNCT treatment is also underscored, necessitating consideration in both experimental and clinical contexts. The study demonstrates that synergistic effects between disparate radiation fields lead to increased misrepairs and enhanced biological impact. Additionally, the biological effect diminishes with rising boron concentration, emphasizing the need to account for intercellular DNA damage heterogeneity. This methodology offers valuable insights for the development of new boron compounds and precise assessment of bio-weighted doses in clinical settings and can be adapted to other therapeutic modalities.

Dose-Dependent Performance of Boron-Implanted Self-Aligned Bottom-Gate IGZO TFTs

This work provides an interpretation of donor activation in self-aligned bottom-gate (SA-BG) Indium-Gallium-Zinc Oxide (IGZO) TFTs with ion-implantation of boron (11B+) species as the source/drain treatment. The effect of implant dose on device operation was investigated. Transfer characteristics appeared similar with a boron dose of 1 and 2×1015 cm-2 however, a 45% decrease in max current was observed for devices implanted with a 4×1015 cm-2 dose. Van der Pauw measurements displayed a similar trend; an increase in boron dose resulted in an increase in sheet resistance. A left-shift in transfer characteristics was observed with a greater shift in the 4×1015 cm-2 dose devices, following thermal stability treatments. The existence of two separate boron species is hypothesized, (1) an electrically active donor species involving a relatively small fraction of the total boron concentration and (2) additional boron interstitials and/or other associated defects. A detailed discussion on developed arguments arrived at through analysis of TFT electrical characteristics is presented.

Simulation of Boron Dose and Irradiation Time in Lung Cancer Treatment with Boron Neutron Capture Therapy (BNCT) Using MCNP-6

<p>Boron Neutron Capture Therapy (BNCT) is a cancer radiation treatment. This approach employs a boron carrier agent in the form of a chemical that is injected into the body and then travels to the cancer cells. In a lung cancer case study, BNCT treatment simulation was carried out using Monte Carlo N Particle (MCNP) software version 6.2. The goal of this study was to determine the most effective boron concentration and irradiation duration in lung cancer therapy utilizing the BNCT method. The geometry based on a phantom model created by Oak Ridge National Laboratory (ORNL). The simulated cancer geometry, which is placed in the right lung's middle lobe. The skin, ribs, and right lung are among the organs at risk. The skin, ribs, and right lung are among the organs at risk. The neutron source for the simulation is the collimator output from the Kartini Nuclear Reactor's thermal column. In this simulation, the variations in boron concentrations were 40 g/g, 45 g/g, 50 g/g, 55 g/g, and 60 g/g of cancer tissue at 5 g/g intervals. The researchers discovered a link between boron injection concentration and irradiation time, with higher boron injection concentrations resulting in shorter irradiation times. The volume of boron injected determines the effective dose absorbed by healthy tissue surrounding cancer cells. The effective boron concentration for lung cancer therapy is 60 g/g, with deterministic cell killing in the rib marrow and right lung. When utilizing a boron concentration of 60 g/g, the irradiation time is 20.4 minutes. Boron concentrations of 60 g/g are projected to create an effective irradiation time for BNCT-based lung cancer therapy based on the ALARA principle due to their shorter duration when compared to other concentration variations.</p>

Dosimetry of Neutron Flow and Gamma-Radiation for two Neutron Beam Shaping Assembly at the VITA Facility using a Scintillator Detector

The BNCT method is considered one of the promising methods of external beam therapy in the treatment of radioresistant tumors such as glioblastoma, melanoma and others, which selectively destroy cancer cells due to previous accumulations of boron-10 isotopes stable inside them, and subsequent irradiation with epithermal neutrons. As a result of neutron capture by boron, nuclear radiation interacts with the release of a large amount of energy (charged particles with a high linear energy transfer), which leads to the destruction of the cancer cell. This method is distinguished by a short number of treatment sessions compared to traditional radiation therapy (photons and electrons). In this study, the boron dose rate and the dose rate of gamma radiation in air and in a water phantom are measured using a small-sized neutron detector with a pair of cast polystyrene scintillators, one of which is enriched with boron, developed at BINP. Two neutron beam shaping assembly were used, one with a magnesium fluoride crystal moderator and the other with a Plexiglas moderator. The article will present the experimental results, discuss the features of the neutron beam shaping assembly and formulate recommendations for conducting clinical trials of the BNCT technique

Effect of boron and molybdenum on growth and yield attributes of cauliflower (Brassica oleraceae Var. Botrytis L) at Salyan, Nepal

A research study was conducted to investigate the impact of varying levels of boron and molybdenum on the growth and yield parameters of the Silvercup-60 variety of cauliflower in the fields of Luham, Salyan during the winter season of 2022. The experiment comprised seven treatments arranged in a Randomized Complete Block Design (RCBD) with three replications. Each replication included seven treatments denoted as follows: T1 (Control), T2 (Borax @10 kg/ha), T3 (Ammonium Molybdate @1 kg/ha), T4 (Borax @10 kg/ha + Ammonium Molybdate @1 kg/ha), T5 (Borax @10 kg + Ammonium Molybdate @2 kg/ha), T6 (Borax @20 kg/ha + Ammonium Molybdate @1 kg/ha), and T7 (Borax @20 kg/ha + Ammonium Molybdate @2 kg/ha), representing different doses of boron and molybdenum. Various growth parameters, including plant height, number of leaves, leaf length, and leaf width, were recorded at intervals of 15, 30, 45, and 55 days post-transplanting, along with yield parameters such as curd diameter and curd yield. Notably, treatment T4 (Borax @10 kg/ha + Ammonium Molybdate @1 kg/ha) exhibited significantly superior curd diameter (19.03 cm) and yield (16.41 mt/ha) compared to the control group, while the control group yielded the lowest values for these parameters. Based on the findings of this study, it can be concluded that the application of boron and molybdenum at a rate of 10 kg/ha of Borax and 1 kg/ha of Ammonium Molybdenum is recommended for cauliflower cultivation in the Salyan district, as it leads to enhanced growth and yield of cauliflower crops.

Residual Effect of Boron on Yield, Yield Parameters and Economics of Knol-Khol (Brassica oleracea var. gongylodes L.) in Coastal Regions of Odisha

Background: Rice-vegetable is one of the remunerative and profitable cropping system in Odisha to be grown in kharif and rabi season respectively. From GPS based soil survey and analysis by AICRP on Micronutrient, OUAT, Bhubaneswar, it was observed that boron deficiency was widespread in soils of Odisha (8-79%) and is a major constraint in light texture sandy loam soils under vegetable production. Growing of a shallow rooted crop like rice as direct crop followed by a deep-rooted vegetable crop can utilize leached Boron efficiently from subsoil thereby benefitting both rice and vegetable. Farmers in coastal Odisha generally grow knol-khol after rice and apply B frequently to both rice and knol-khol. Boron is one of the essential micronutrients required for the normal growth of knol-khol and plays an important role in yield of quality knobs. Till now no proper method and dose of boron is standardized for long term rice based vegetable cropping system regarding whether application of small dose every year is suitable or bulk quantity once or application in alternate years. Methods: A field experiment was conducted at E bock of Central Research Station, under AICRP on Micronutrient, O.U.A.T, Bhubaneswar to standardize the dose and frequency of boron application for rice-knol khol cropping system where boron is applied to first crop and knol-khol gets residual boron. In the present investigation residual effect of different graded doses of boron and its frequency of application on growth, yield, quality, post-harvest shelf life and economics of knol-khol for the year 2018-19 was studied. The experiment was laid out in a Factorial Randomized Block Design with three replications and four different doses of boron (0.5 kg ha-1, 1.0 kg ha-1, 1.5 kg ha-1 and 2.0 kg ha-1) at three different frequencies (application of boron once, alternate year and every year) were applied. Result: The maximum values of growth attributing parameters were recorded with residual effect of boron @ 1.5 kg ha-1 in every year application. Highest yield and yield attributing characters such as diameter of knob (8.70 cm), length of knob (6.53 cm) and total knob yield (224.72 q ha-1) were recorded with residual effect of boron @ 1.5 kg ha-1 in every year application. Highest B: C ratio of (2.27) was observed with residual effect of boron applied @ 1.5 kg ha-1 in every year application.

Influence of Drip Fertigation and Foliar Spray of Boron on Yield and Nutrient Uptake by Cucumber cv. Himangi

The effect of fertigation and foliar application of boron on yield, uptake of nutrients and nutrient use efficiency by cucumber Cv. Himangi was studied during two consecutive years 2018-19 and 2019-20. An experiment was carried out in open field conditions with five fertigation levels viz., 100 % RDF through soil, 120 %, 100 %, 80 % and 60 % RDF through fertigation in ten equal splits at 10 days interval along with three levels of foliar application of boron viz. 0.0, 0.1, and 0.2 per cent concentration at 30, 45 and 60 DAS to determine suitable fertigation and foliar spray of boron dose for cucumber cultivation. The experiment was consisting of fifteen treatment combinations of recommended doses of water soluble fertilizers, comprising of five levels of fertigation. The results indicated that, yield, nutrient uptake and nutrient use efficiency of nitrogen, phosphorus and potassium under study were significantly influenced by various fertigation and boron levels. On the basis of pooled data, it was observed that, among various treatment combinations, minimum male : female sex ratio (1:4), maximum average weight of fruit (239.88 g), yield per vine ( 2.44 kg), yield ( 228.37 q/ha), uptake of nitrogen by shoot, ( 13.03 kg/ha), ( 81.62 kg/ha) by fruit and (94.01 kg/ha) by whole cucumber vine, maximum uptake of phosphorus by shoot (3.62 kg/ha), (21.52 kg/ha) by fruit and ( 25.13 kg/ha) by whole cucumber vine and the maximum uptake of potassium by shoot ( 14.05 kg/ha), by fruit (101.45 kg/ha) and ( 115.20 kg/ha) by whole cucumber vine, B:C ratio (2.99) and minimum (27.73, 25.71 and 17.2, 16.85 and 55.28, 50.28 %, respectively) nutrient use efficiency of NPK were recorded with the application of 120 % RDF through fertigation due to nutrient losses through leaching, devolatilization. While, maximum (36.70, 34.70 and 25.38, 21.90 and 65.81, 63.43 respectively) nutrient use efficiency of NPK was recorded with the application of 60 % RDF through fertigation. The maximum (22.59, 20.61 and 6.99, 7.70 and 27.30, 30.47 %, respectively) nutrient use efficiency with foliar application of boron at concentration of 0.2 per cent and minimum (3.60, 3.44 and 0.56, 0.52 and 3.72, 4.05 %, respectively) nutrient use efficiency with foliar application of boron at concentration of 0.1 per cent.

Investigation of Boron Addition to Dried Alfalfa In Vitro Ruminal Profile and Potential for Reducing Enteric Methane Emission

The aim of our study is to investigate the effects of increasing doses of boron on methane gas production amounts, short chain fatty acids level, protozoa number and organic matter digestibility in vitro with HFT (Hohenheim Futterwert Test) technique. In vitro incubation was performed in the Hohenheim Gas test method at 39°C for 24 hours in the study. Dried alfalfa was used as substrate for fermentation. Increasing doses of boron were used on fresh rumen fluid, buffer solution and dried alfalfa. In the study, 54 syringes were used for a total of 6 groups, including 1 control and 5 trial ( B1: 25 ppm boric acid, B2: 50 ppm boric acid, B3: 100 ppm boric acid, B4: 200 ppm boric acid, B4: 500 ppm boric acid). The measurement of methane gas at 2, 4, 6, 8, 12 and 24th hours of boric acid addition at increasing doses was found to be significant the difference between the groups at each hour under in vitro rumen conditions. When we look at the effect of the dose; Increasing doses appear to reduce methane production for each measured hour. The difference between the measured hours (except the 24th hour) of each group was not significant. However, the difference between the groups was found to be significant in the methane measurement made only for the 24th hour. At the 24th hour of fermentation under in vitro rumen condition, acetic acid and total short chain fatty acid values were linearly and cubically affected. With increasing doses of boron, propionic acid, isobutyric acid, butyric acid and valeric acid values were linearly affected The total number of protozoa was not affected by the addition of increasing doses of boron at the 24th hour of fermentation under in vitro rumen conditions. Consequently, the addition of boric acid at increasing doses in in vitro rumen conditions decreased methane production and positively affected the amount of some short-chain fatty acids, organic matter digestibility and total short chain fatty acids. In the light of these findings, it was emphasized that boron has the potential to reduce methane emissions from ruminant animals, considering the greenhouse gas effect.

A compact scintillator-based detector with collimator and shielding for dose monitoring in boron neutron capture therapy

Boron neutron capture therapy exploits 10B(n,α)7Li reactions for targeted tumor destruction. In this work, we aimed at developing a dose monitoring system based on the detection of 478keV gamma rays emitted by the reactions, which is very challenging due to the severe background present. We investigated a compact gamma-ray detector with a pinhole collimator and shielding housing. Experimental nuclear reactor measurements involved varying boron concentrations and artificial shifts of the sources. The system successfully resolved the 478keV photopeak and detected 1cm lateral displacements, confirming its suitability for precise boron dose monitoring.

Effect of nitrogen and boron treatments on harvest index and nitrogen use efficiency in sugar beet

The aim of this study is to examine the effect of different doses of nitrogen (N) and boron (B) treatment on sugar harvest index (SHI), nitrogen harvest index (NHI), and nitrogen use efficiency (NUE) parameters and to determine the economic optimum nitrogen rates (EONR) in sugar beet. The experiment was set up in a randomized block factorial design with three replications. Five doses of N (0, 90, 180, 270, and 360 kg N ha-1) and four doses of B (0, 2, 4, and 6 kg B ha-1) were applied in the study. According to the results of the research, the SHI decreased statistically significantly with the increase of dose of the N treatment, but the NHI was not affected by the N treatment. Physiological efficiency of nitrogen in taproot dry matter yield (NPETDMY) and physiological efficiency of nitrogen in sugar yield (NPESY) decreased statistically significantly (p<0.01) with the increase in the dose of N treatment. A similar case was observed in the parameters of nitrogen agronomic efficiency (NAgE) and nitrogen uptake efficiency (NUpE). The increase in boron treatment doses statistically significantly (p<0.01) increased the NAgE in the first year. The EONR, calculated using the quadratic model, was found to be 240 kg N ha-1 on average of two years. As a result, the nitrogen use potential decreased with the increase of N doses applied to sugar beet. The use of EONR can be recommended for optimum yield and quality in the region.

Effect of Foliar Application of Boron on the Growth and Yield of Green Chili (Capsicum annum L.)

A field study was performed at the Bangladesh Institute of Nuclear Agriculture (BINA) sub-station farm, Rangpur during Rabi season of 2021-22 to determine the effect of varieties and foliar application of boron on the growth and yield of green chili. The treatments were laid out in a Split-plot and replicated three times. Different concentrations of foliar Boron were applied as foliar sprays. The experiment comprised of nine treatments: T1= 0.5 g BL-1H2O at vegetative stage, T2= 1.0 g BL-1H2O at vegetative stage, T3= 0.5 g BL-1H2O at vegetative stage + 1.0 g BL-1H2O at Fruiting stage, T4= 1.0 g BL-1H2O at vegetative stage + 1.0 g BL-1H2O at Fruiting stage, T5= 1.5 g BL-1H2O at vegetative stage & T6= 1.5 g BL-1H2O at vegetative stage + 1.5 g BL-1H2O at Fruiting stage, T7= 2.0 g BL-1H2O at vegetative stage, T8= 2.0 g BL-1H2O at vegetative stage + 2.0 g BL-1H2O at Fruiting stage & T9 = Control and two chili varieties/lines viz. Binamorich-2 & RCL-1. From the present study, it was concluded that the highest fresh chili yield (18.11 tha-1) produced Binamorich-2 compared to RCL-1 which gave 14.52 tha-1. Among the nine treatments of foliar boron, B @ 2.0 g/L H2O at vegetative stage + B @ 2.0 g/L H2O at fruiting stage exhibited the highest fresh chili yield (21.22 tha-1). In respect of the interaction effect of foliar boron and variety, the Binamorich-2 was giving the highest fresh chili yield (25.00 tha-1). However, further research will be needed with different doses of foliar boron for promising production of chili at different locations of Bangladesh.

English

Boron sources and doses can positively increase fruit quality and tomato yield. This study aimed to evaluate the influence of boron doses and sources on the development and yield of industrial tomatoes under irrigation. A randomized block design with four replications in a 3x4x2 factorial scheme was used. Three boron sources, boric acid, borax, and ulexite; four boron doses (0, 1, 2, and 3 kg/ha); and two locations, Goianésia, GO (AE I) and Vila Propício, GO (AE II) were evaluated. Stem diameter (SD), plant height (PH), the total number of fruits (TNF), the number of ripe fruits (NRF), the number of green fruits per plant (NGF), the number of lateral branches per plant (NLB), longitudinal fruit diameter (LFD), transversal fruit diameter (TFD), yield (YLD), total soluble solids content (°BRIX), pH, and titratable acidity (TA) were evaluated. There was no significant difference for the evaluated boron sources, while boron doses statistically influenced the increase in the TNF, NRF, °BRIX, and YLD. The dose of 1.23 kg ha-1 provided the highest values of ºBRIX (4.75%). The dose of 1.89 kg/ha provided the highest yield (119001.5 kg/ha), regardless of sources and locations. Boron sources did not significantly affect tomato crops, so both can be used for the study conditions

A dose calculation algorithm for boron neutron capture therapy using convolution/superposition method

The convolution/superposition (C/S) method originally designed for photon dose calculation was first applied for developing a treatment planning system for boron neutron capture therapy. The original concept of TEGMA (total energy generated per unit mass) was proposed to represent distinctive dose components from neutron reactions with the elements in the patient's tissue. First, neutron fluence distributions in a homogeneous brain phantom irradiated with an energy-groupwise pencil beam of 2.5 × 2.5 mm2 were calculated using the MCNP6.2 code. Then, a library of energy-groupwise TEGMA and KERMA were generated and stored in the developed C/S code. As a benchmark, dose distributions in a cuboid phantom and a human head phantom were calculated using the developed C/S and PHITS Monte Carlo codes. A neutron beam having a continuous epithermal spectrum and a square field of 22.5 × 22.5 mm2 or a circle field of 22.5 mm in diameter was assumed to be incident on the phantoms. The human head phantom was created by the pre-processing including the voxelization and transformation of test DICOM CT images. The differences in boron doses between C/S and MC ranged from 2% to 6%. In nitrogen doses, the differences were from 4% to 9%. A large discrepancy observed in hydrogen lateral dose profiles could be explained by the differences in cross-section data and recoil-proton transport algorithms of MCNP6.2 and PHITS. With isodose curves normalized at the center of the tumor in the human head phantom, they were almost identical in the range of 60%–110% for both cases. The C/S have underestimated the backscattering neutron and showed a larger absorbed dose gradient around 40% region. The calculation time of C/S using Intel i7-10700 processor was less than 1 min for both phantoms. The calculation time of PHITS using three Intel Xeon E5-2640 v4 processors was 15.5 min for the cuboid phantom and ∼380 min for the human head phantom. The proposed algorithm has the advantages of high speed while promising fair accuracy in BNCT dose calculations.

Elastic backscattering during boron implantation in Si1-xGex

We have investigated the elastic backscattering which occurs during ion implantation, and its impact on the retained implantation dose. A series of Si1-xGex (0 ≤ x ≤ 1) alloy films were implanted with 5 × 1014 atoms/cm2 of 11B at an energy of 10 keV. Nuclear reaction analysis (NRA) was used to characterize the retained boron dose within the Si1-xGex (0 ≤ x ≤ 1) samples by means of the 11B(p,α1)2α12 nuclear reaction. The experimental results show that the elastic backscattering effect is significant in this case, with the retained boron dose decreasing linearly as the target matrix varies from pure silicon to pure germanium. Our findings are in good agreement with simulations carried out using the SRIM-2013 software. Our study indicates that the backscattering effect during implantation must be accounted for when a specific concentration is targeted, or when adopting an implanted film as a reference standard, for example, in secondary ion mass spectrometry.

Doses and application timing of boron on the agronomic characteristics of corn

Corn cultivation holds great economic importance in Brazil, as it is grown throughout the country, covering approximately 21.5 million hectares annually, with a production of 113 million tons in the 2021/2022 harvest. However, crop production is directly linked to plant nutrition, and boron (B) is one of the essential micronutrients for plant development. Its deficiency imposes limitations on Brazilian agricultural crops. Therefore, the objective of this study was to evaluate the vegetative and productive characteristics of corn in response to the application of different doses of boron at different application timings. The experimental design used was completely randomized, in a 3x5 factorial scheme, with 4 replications, consisting of the combination of 5 doses of B (0, 0.5, 1, 2, and 4 kg ha-1) applied in the sowing furrow and at the V4 and V7 phenological stages. Plant height, first ear insertion height, stem diameter, number of rows per ear, number of grains per row, number of grains per ear, ear weight, grain weight per plant, and 100-grain weight were evaluated. No significant differences were observed between the doses and/or timing of boron application in the hybrid corn used in this study.

Dosimetry for boron neutron capture therapy developed and verified at the accelerator based neutron source VITA

The method of boron neutron capture therapy for malignant tumors, proposed in 1936, is beginning to enter clinical practice. The development of dosimetry tools for characterization of therapeutic mixed neutron-photon beam and assessing the patient’s response to treatment is becoming relevant. In this work, a number of dosimetric techniques have been developed: a compact neutron detector with a pair of cast scintillators, one of which is enriched with boron, to measure the boron dose and the γ-ray dose; cell dosimeter for measuring the sum of the equivalent dose of fast neutrons and the equivalent nitrogen dose; prompt γ-ray spectroscopy for in situ measurement of boron dose in real time; epithermal neutron flux monitor for measuring the epithermal neutron flux. Their verification carried out on the accelerator based neutron source VITA showed that they can become convenient and reliable tools for characterization of neutron beam and assessing the patient’s response to treatment.

Feasibility study of optical imaging of the boron-dose distribution by a liquid scintillator in a clinical boron neutron capture therapy field.

Evaluation of the boron dose is essential for boron neutron capture therapy (BNCT). Nevertheless, a direct evaluation method for the boron-dose distribution has not yet been established in the clinical BNCT field. To date, even in quality assurance (QA) measurements, the boron dose has been indirectly evaluated from the thermal neutron flux measured using the activation method with gold foil or wire and an assumed boron concentration in the QA procedure. Recently, we successfully conducted optical imaging of the boron-dose distribution using a cooled charge-coupled device (CCD) camera and a boron-added liquid scintillator at the E-3 port facility of the Kyoto University Research Reactor (KUR), which supplies an almost pure thermal neutron beam with very low gamma-ray contamination. However, in a clinical accelerator-based BNCT facility, there is a concern that the boron-dose distribution may not be accurately extracted because the unwanted luminescence intensity, which is irrelevant to the boron dose is expected to increase owing to the contamination of fast neutrons and gamma rays. The purpose of this research was to study the validity of a newly proposed method using a boron-added liquid scintillator and a cooled CCD camera to directly observe the boron-dose distribution in a clinical accelerator-based BNCT field. A liquid scintillator phantom with 10 B was prepared by filling a small quartz glass container with a commercial liquid scintillator and boron-containing material (trimethyl borate); its natural boron concentration was 1wt%. Luminescence images of the boron-neutron capture reaction were obtained in a water tank at several different depths using a CCD camera. The contribution of background luminescence, mainly due to gamma rays, was removed by subtracting the luminescence images obtained using another sole liquid scintillator phantom (natural boron concentration of 0wt%) at each corresponding depth, and a depth profile of the boron dose with several discrete points was obtained. The obtained depth profile was compared with that of calculated boron dose, and those of thermal neutron flux which were experimentally measured or calculated using a Monte Carlo code. The depth profile evaluated from the subtracted images indicated reasonable agreement with the calculated boron-dose profile and thermal neutron flux profiles, except for the shallow region. This discrepancy is thought to be due to the contribution of light reflected from the tank wall. The simulation results also demonstrated that the thermal neutron flux would be severely perturbed by the 10 B-containing phantom if a relatively larger container was used to evaluate a wide range of boron-dose distributions in a single shot. This indicates a trade-off between the luminescence intensity of the 10 B-added phantom and its perturbation effect on the thermal neutron flux. Although a partial discrepancy was observed, the validity of the newly proposed boron-dose evaluation method using liquid-scintillator phantoms with and without 10 B was experimentally confirmed in the neutron field of an accelerator-based clinical BNCT facility. However, this study has some limitations, including the trade-off problem stated above. Therefore, further studies are required to address these limitations.

Developmental Response of Berseem (Trifolium alexandrinum L.) to Boron

The aim of the study was to determine the effect of boron fertilization on agromorphological properties of berseem (Trifolium alexandrinum L.). The field experiment was arranged in randomized blocks with divided parcels. It was applied with 3 replications in 2017 and 2018 years in Ankara conditions. Three different berseem varieties (Derya, Erix, Mario) were sown to main parcels and 5 different boron fertilizer doses (0, 100, 200, 400, 800 g da-1) were applied to sub-parcels. According to the research results; plant height was varied between 67.20 and 98.33 cm. Stem diameter was 3.43-4.45 mm, stem numbers were 6.17-11.67 pieces and head numbers were 7.28-15.02 pieces. The highest plant height and stem diameter were exhibited by variety of Mario. Erix displayed the highest development in terms of stem numbers, Derya showed the highest development in terms of head numbers. When boron doses were compared with control parcel, the highest plant height, stem diameter, stem numbers and head numbers were obtained at 100 g da-1 boron dose.

The Critical Levels of Boron for Germination and Seedling Growth of Melon

This study was conducted to determine the effects of boron levels on germination and seedling growth of melon cultivars with different fruit characteristics under laboratory conditions. The seeds of three melon cultivars (Hasanbey 1, Kırkağaç 589, and Toros Sarıbal) were germinated at different boron levels (0, 20, 40, 60, 80, and 100 mg L-1) constituted by sodium borate (Na2B8O13.4H2O). Germination percentage, mean germination time, germination index, seedling growth parameters, and seedling dry matter were investigated. The optimum and toxicity levels of boron were calculated by regression analysis. Germination percentage, mean germination time, and germination index were not affected by increasing boron levels. A boron dose of 20 mg L-1 promoted root length, shoot length, and seedling fresh weight of melon; however, seedling growth of melon cultivars was inhibited at higher boron levels than 40 mg L-1. Seedling dry weight and dry matter significantly enhanced when the boron levels were increased. Root length was more sensitive to boron than shoot length. Melon cultivars showed different responses to boron levels and the highest seedling growth parameters were obtained from Kırkağaç 589. The optimum boron level for shoot growth was calculated as 12.8 mg L-1, while the inhibitory level of boron for root growth was 65.4 mg L-1. The toxicity of boron on the germination performance was not detected and higher levels than 20 mg L-1 inhibited seedling growth of melon.

Effects of Coating with Different Doses of Boron Compound on Germination Parameters of Cotton Seeds

In this study, seeds of cotton plants were coated with different boron concentrations and their effect on seedling growth was investigated. The experiment was carried out at Muş Alparslan University, Faculty of Applied Sciences, Department of Plant Production and Technologies, under laboratory and greenhouse conditions, according to the Randomized Plots Trial Design with 4 in laboratory and 3 in greenhouse replications, respectively. In the study, Di-sodium tetraborate decahydrate (Na2B4O7.10H20) (M=381.37 g mol-1) with a minimum purity of 99% boron compound have been used in different doses; 0 (control), 250, 500, 750, 1000, 1250, 1500, 1750, 2000, 2250 and 2500 mg kg-1. According to the results of the regression analysis, it was determined that as the boron dose in the application increased, the root length was positively correlated and other parameters were negatively correlated. In terms of the parameters examined, 250 mg kg-1 Kaolin+liquid K-Humate (15% HA) 400 ml kg-1 (U3) boron application under laboratory conditions showed better results, and 1000 ml kg-1 Kaolin+liquid boron application under greenhouse conditions. It was determined that the application of K-Humate (15% HA) 400 ml kg-1 (U6) promoted growth. In addition, it was found that the results were confirmed in the grouping of the relationships between applications and parameters with heat map clustering and PCA graphs. As a result, it was determined that the toxic range of boron applications applied to the seed in the cotton plant was very narrow, and that it promoted seedling development and root elongation in the U6 application, but it was concluded that the study should also be studied in field trials in order to make more decisive decisions.