bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of small PRESAGE® samples for measurements near the dosimeter edges
Authors: Costa Filipa , Doran Simon , Adamovics John , Nill Simeon , Hanson Ian M , Oelfke Uwe
Published: August 2019

Measurements near the edges of PRESAGE® 3D dosimeters will be important for validating the electron return effect (ERE) that can occur at tissue-air interfaces during radiotherapy treatment delivered with the Elekta MR-linac. We investigate and characterize the spatially non-uniform response of small samples of PRESAGE® to radiation in a conventional linac. We develop a correction to compensate for these non-uniformities and obtain dose values near the dosimeter edges. Five samples from the same batch were uniformly irradiated in a water tank with a broad beam. The non-uniform response of the samples to radiation was investigated and a radial dose-correction function was generated from each sample to obtain a correction image. We then applied these correction images to another sample from the same batch, irradiated with four beams in an inhomogeneous medium, and compared this with the relevant simulated data. Additionally, we irradiated samples after physically removed their edges (axially and top and bottom edges). Higher sensitivity to radiation was observed at the edges (~6mm) of the samples in comparison with the central region. Applying the dose correction function improved agreement between simulations and measurements, but only partial correction was possible. A uniform response was observed on the samples with the edges removed, which we propose as the best option to measure dose at the edges of PRESAGE® samples.
The MD Anderson experience with 3D dosimetry and an MR-linac
Authors: Ibbott Geoffrey S. , Le Hannah J. , Roe Yvonne
Published: August 2019

A recent extension of image guidance in radiation therapy has been brought about by the introduction of the MR-linac; a hybrid system comprising an MR imager and a medical linear accelerator. The University of Texas MD Anderson Cancer Center is one of seven institutes around the world that have collaborated with the manufacturer to develop this system and bring it into clinical use. In the process, a great deal has been learned about the influence of the magnetic field on radiation dose deposition and upon dosimetry systems. A number of dosimetry systems have been evaluated and issues affecting their performance have been investigated. The potential value of three-dimensional dosimetry systems has been explored.
SRS and SBRT and advanced dosimetry: Duke experiences
Authors: Oldham Mark
Published: August 2019

Stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) are among the most demanding of radiation therapy techniques in terms of requirements for high accuracy and conformality of treatment delivery. Compared to conventional treatments, they require specialized high-precision equipment (including high specification medical accelerators and alignment frames), extensive imaging (including multi-modal and motion management methods), specialized Quality Assurance protocols, and increased person-power effort. In addition, the high dose-per-fraction renders SRS/SBRT a high-stakes treatment setting, where small errors may cause significant treatment morbidity in normal healthy tissue. All of these issues combine to render SRS/SBRT one of the most opportunistically rich and clinically important areas for advanced dosimetry research. Some of the applications of advanced 3D dosimetry to SRS and SBRT and small field treatment verification are explored. Applications include base of skull IMRT, single-isocenter multi-lesion radiosurgery, pre-clinical precision treatments, interpreting the clinical significance of 3D QA data, remote dosimetry, dosimetry in magnetic fields, trigeminal neuralgia, rodent-morphic dosimetry, motion, and small field commissioning.
Influence of the components of a radiochromic PVA – Iodide gel dosimeter on the optical dose response
Authors: Hayashi Shin-Ichiro , Ono Kaoru , Fujino Keisuke , Fujimoto Sachie
Published: August 2019

A novel radiochromic gel dosimeter based on a poly(vinyl alcohol)-iodide complex (PVA-I) has been developed with the aim of using it in optical computed tomography (CT). The PVA-I gel dosimeter exhibits excellent characteristics such as high sensitivity, dose rate independence, a wide dose range, and especially reusability. The standard PVA-I gel dosimeter is composed of poly(vinyl alcohol) (average degree of polymerization 1000 and degree of saponification 88 mol%), iodide (potassium iodide), reducing sugar (fructose), gelling agent (gellan gum), and water. In this study, the influence on dose response is investigated upon substitution of the components by PVAs with different degrees of polymerization (500, 1500, 3500) and saponification (80 mol%, 98 mol%), different iodide salts (LiI, NaI, NH4I), and different reducing sugars (glucose, maltose, lactose). The results show that these substitutions have little effect on the dose rate dependence, while the iodide salt affects the sensitivity.
Preliminary investigation of a reusable radiochromic sheet for radiation dosimetry
Authors: Collins Cielle , Kodra Jacob , Yoon Suk Whan , Coakley Robert , Adamovics John , Oldham Mark
Published: August 2019

This work investigates a novel reusable radiochromic sheet developed as an economic film substitute or as a radiochromic bolus. The radiation-induced optical density (OD) change of the sheet is read-out with a commercial flat-bed optical scanner. An optimized readout procedure was developed including an optimal scan-time window. Fundamental radiochromic properties of the sheets were characterized including temporal decay of OD, dose sensitivity and consistency through repeated irradiations, and temperature sensitivity. The radiation induced OD change in the sheets was found to decay to baseline within ~24 hours, after which the sheet could be reused. The sensitivity of subsequent re-irradiations was found to be consistent within ±5% (coefficient of variation of 4.5%) for at least 6 irradiations and potentially many more. Importantly, the sheets were not observed to carry any detectable memory of previous irradiations within measurement uncertainty. In conclusion, the Presage sheets show promise as an economic multi-purpose alternative for film applications and potentially as a radiochromic bolus. Further work is required to test the sheet in diverse clinical applications, and to develop a softer material for bolus applications.
Development of a reusable PVA-GTA-I gel dosimeter for 3D radiation dose assessments
Authors: Taño J , Hayashi S , Hirota S , Gonzales CA , Yasuda H
Published: August 2019

A novel formula of crosslinked polyvinyl alcohol (PVA) with glutaraldehyde (GTA), a tri-iodide complex, and glucono-δ-lactone (GDL) acid for gel dosimetry was investigated in the present study. The objectives of this study were to evaluate the formula’s dose response properties through spectrophotometry and possible reusability by reannealing. After production, the gel samples were irradiated from 1 to 70 Gy of gamma-rays from a Cs-137 source with a constant dose rate of 0.857 Gy/min. Spectrum data were obtained using a UV-Vis spectrophotometer and analyses were done for dose linearity, dose sensitivity versus GTA concentration, and absorbance profile versus time. The resulting unirradiated gel samples were colorless and transparent, while the irradiated samples turned to a reddish-brown hue with a peak absorbance response at 490 nm. Dose linearity results indicated R2 values of 0.9, 0.986 and 0.8 for GTA concentrations of 7 mM, 15 mM and 30 mM, respectively. Moreover, dose sensitivity is higher for lower concentrations of GTA. Time progression results indicated that the absorbance decreases within one day after irradiation and increases subsequently. Through reannealing for 24 hours at 45°C in an oven, a colorless material with an absorbance value identical to the unirradiated samples was finally made for samples irradiated from 1 to 20 Gy, while the 70 Gy irradiated sample had a significant decrease in color and absorbance peak. This radiochromic gel dosimeter is promising and should be useful for 3D radiation dose assessments. Further investigation of the formula and preparation techniques are suggested for future experiments.
Three-dimensional radiochromic and polymer gel dosimeters with Pluronic F-127 matrix – a review of current research
Authors: Kozicki M , Jaszczak M , Kwiatos K , Maras P , Kadlubowski S , Wach R , Dudek M
Published: August 2019

A co-polymer of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic F-127, PEO-PPO-PEO) was proposed as a physical gel matrix, substituting gelatine for three-dimensional polymer gel dosimeters and as a matrix for the preparation of new radiochromic gel dosimeters. Two polymer gel dosimeters and seven radiochromic gel dosimeters were obtained with this new matrix. In this review we summarise the main advantages of using Pluronic F-127 for manufacturing radiation dosimeters and the best performing new Pluronic dosimeters.
Making and assessing 3D dosimeters
Authors: Jordan Kevin , De Deene Yves
Published: August 2019

Several 3D dosimeters are commercially available. However, there are many circumstances that require a customized 3D dosimeter. Examples include feasibility tests of non-standard treatment modalities, inhomogeneous tissue configurations, unique shapes and sizes and teaching. In this session, general approaches for preparing radiochromic dosimeters, Fricke and polymer gel dosimeters, micelle gel and silicone dosimeters were presented. Advise will be given to developers of new 3D dosimeters. For optical readout, light absorption and scatter can limit the practical size of dosimeters. Specifically, increasing from 5 to 15 cm diameter dosimeters is optically challenging. Strategies to maximize initial optical transmission were presented. For MRI readout, the dose resolution is determined by both the dosimeter sensitivity and the pulse sequence parameters and the accuracy is determined by the sensitivity of the dosimeter to temperature and dose rate, next to imaging performance. For X-ray CT imaging, the dose resolution is determined by the sensitivity of the dosimeter which largely depends on the polymer density that can be achieved. The importance of characterizing the dosimeter in terms of dose sensitivity and stability, spatial integrity, dose rate and fractionation dependence, oxygen and ambient light sensitivity, temperature sensitivity and thermal history were emphasized. The dosimeter requirements also dictate the types of vessels and scanners appropriate for readout. For example, the preferred dosimeter formulation may include a compound that is incompatible with the preferred vessel.
Comparison of low dose proton and photon irradiation induced polymerization processes in advanced nMAG gels using Raman spectroscopy
Authors: Šeperienė N , Adlienė D
Published: August 2019

A rapid development of the new radiation based cancer treatment technologies that are more individualized and patient oriented request precise 3D treatment dose verification methods in high dose gradient fields. Polymeric dose gels are excellent 3D dosemeters that allow analysis of spatial dose distribution in the irradiated target and also in the regions out of the target since the investigation of low dose induced secondary effects (secondary cancer, inflammations) stands on the priority list. Since the sensitivity of dose gel to different types of irradiation depends on radiation induced polymerization processes, in this work we present Raman analysis results related to advanced nMAG dose gels polymerization upon its irradiation with high energy photons and protons to doses ≤ 5 Gy.
Clear micelle gel dosimeter with nanoclay
Authors: Hayashi K , Nemoto M , Takanashi T , Kang Y , Togo H , Kotoku J , Kobayashi T , Mihashi M , Hayashi S , Gotoh H
Published: August 2019

We built a clear micelle gel dosimeter with nanoclay. Jordan et al. reported that Laponite RD clay nanoparticles when added to radiochromic leucomalachite green micelle gels eliminate diffusion and increase the dose sensitivity by roughly ten folds. However, owing to the cloudiness of the sample, there was a problem in reading the optical computed tomography (CT). In this study, we constructed a nanoclay-added micelle gel dosimeter by changing the type of gelatin. As a result, in addition to yielding a clear gel and making the optical CT readable, diffusion and temporal stability were improved more than the gel without using nanoclay, and the dosimeter showed the same level of sensitivity and diffusion as the one based on Laponite-added micelle gel reported by Jordan et al.
Novel dual-wavelength optical-CT imaging method for gel dosimeter readout
Authors: Du Yi , Wang Xiangang , Xiang Xincheng , De Deene Yves
Published: August 2019

Dual-wavelength scanning is a technique eliminating the need of phantom repositioning for optical-CT gel readout. To further diminish artifacts caused by phantom impurities, we hereby propose a novel dual-wavelength imaging method based on phantom impurity recognition and correction. In this method, impurities in motion trajectories during phantom rotation are recognized at the reference wavelength via motion-tracking as a binary mask, which is then applied to correct impurity-contaminated pixels at the data wavelength. Compared with the existent dual-wavelength imaging method, the proposed method is demonstrated to be capable of reducing impurity-induced artifacts and improving imaging SNR and CNR in the same process.
Spatial dose distribution analysis of Co-60 HDR brachytherapy of cervical cancer using an AQUAJOINT®-based VIPET polymer gel dosimeter
Authors: Oe Ayumi , Nemoto Mikio , Miyazawa Masanori , Sahade Daniel Antonio , Hamada Toshimasa
Published: August 2019

High-dose rate brachytherapy treatment has become more complicated with the use of three-dimensional image-guided brachytherapy (3D-IGBT) to prepare treatment plans using 3D images, such as those obtained from computed tomography (CT). In planning a 3D-IGBT, spatial measurement of dose distribution verification is recommended. In this study, the spatial dose distribution of intrauterine cavity irradiation by a Co-60 sealed brachytherapy source was acquired using an AQUAJOINT® polymer gel dosimeter. A CT/magnetic resonance imaging (MRI) compatible applicator was inserted into the gel in a bottle. It was irradiated and visualized using MRI. The image was converted to an R2 image using a DD-System (R-TECH INC, Japan), and dose distribution was evaluated using the dose–R2 response curve. The obtained dose distribution, dose profile of the radiotherapy treatment planning system, isodose curve, and gradient passing were calculated. In the dose profile, the dose difference was large near the applicator (high-dose region) and was less than ±2% in the middle-dose region. The isodose curves showed good agreement in the region of 2–6 Gy near the prescription point. The gamma analysis was 87.594% on the sagittal cross-section and 93.711% on the coronal cross-section based on the dose difference (DD)/distance to agreement (DTA) of 3%/3 mm.
Dose reconstruction including dynamic six-degree of freedom motion during prostate radiotherapy
Authors: Muurholm C G , Ravkilde T , Skouboe S , Eade T , Nguyen D T , Booth J , Keall P J , Poulsen P R
Published: August 2019

An in-house developed program for real-time reconstruction of motion-induced dose errors, DoseTracker, was extended to handle rotational target motion in addition to the previously implemented translational motion, and applied offline for prostate VMAT treatments. For translational motion, the motion-induced errors of DoseTracker were in good agreement with ground truth dose reconstructions performed in a commercial treatment planning system. For rotational motion, no ground truth was available, but DoseTracker showed that the VMAT dose is highly robust against static interfractional rotations but quite sensitive to dynamic intrafraction rotations due to interplay effects between target motion and machine motion.
Development of an experimental 3-D tool based on radiochromic films to determine normal tissue doses in external radiotherapy
Authors: Colnot J , Garnier G , Zefkili S , Dumas J-L , Gschwind R , Huet C
Published: August 2019

External radiotherapy largely proved its efficacy to treat cancer. However, this technique leads to unavoidable exposure of normal tissues that may results in adverse effects. One of the main concerns is the induction of second cancers that may appear at the periphery or even away from the treated area. Risk estimation models need accurate 3-D dosimetric data on healthy organs. To this aim, we developed an experimental tool based on radiochromic films measurements. In this work, we present a study performed with a heterogeneous phantom. EBT3 films were positioned in between the phantom slices and irradiated according to a VMAT plan. The dose was reconstructed in 3-D by interpolation thanks to an in-house Matlab tool. Two interpolation methods are studied and the reconstructed dose is compared to independent film measurements for validation. Finally, dosimetric data such as DVH are compared to the TPS evaluation. Continuous interpolation proves to better reconstruct the doses in high gradient areas whereas linear interpolation seems to be a better option to evaluate doses away from the field edge. Besides, TPS and 3-D measurements give comparable results for organs placed inside the beams (maximum 6.3% difference on organs mean doses). However, the TPS tends to underestimate doses to organs placed at least partially outside the fields (from 29 to 59% difference on mean doses). Optimization of the dose reconstruction tool by using a combination of the two interpolation methods is ongoing. Comparison with gel dosimetry will also be investigated.
EPIDs and QA of advanced treatments
Authors: Mijnheer B
Published: August 2019

In this paper I will summarize the various possibilities of EPIDs for their use as tools for QA of advanced treatments. After elucidating the choice of EPIDs for this purpose, I will review the use of EPIDs for pre-treatment and in vivo (transit) dosimetry applications. Several solutions became recently commercially available, allowing relative and/or absolute dose verification at points (0D), in 2D, or in 3D. Each of these solutions will be briefly discussed, indicating the differences in possibilities with respect to QA of advanced treatments. I will conclude with some general remarks about the current status of EPID-based QA of advanced treatments and revealing some future developments in 3D pre-treatment and in vivo dosimetry using EPIDs.
End to end QA in image guided and adaptive radiation therapy
Authors: Schreiner L J
Published: August 2019

It has been suggested that modern radiation therapy could benefit from adopting the “End to End” (E2E) type of testing developed originally in computer science to determine whether applications and systems work as required under real-world scenarios. The motivation for adopting E2E techniques for image guided adaptive radiation therapy validation is to extend beyond current common testing using standard physics QA that inherently probes only select points or systems within the IGART schema. E2E methodologies extend the testing to evaluate complete IGART processes, including the complex interchanges that occur during and throughout a patient’s treatment as clinical staff interpret and respond to information acquired during the treatment course.

While limited radiotherapy E2E QA may have been adopted periodically by clinics when implementing a new treatment technique, clinical E2E QA has been confined to date mainly to tests mediated by external auditing bodies such as IROC, the Imaging and Radiation Oncology Core in the United States. This testing often includes having the clinic in question irradiate a purpose-built phantom containing dosimeters to specific criteria under protocols set by the auditing body. The auditors then determine off site whether the clinic’s treatment process was successful by comparing the dose measurements with the intended dose delivery.

The advance of three dimensional (3D) radiation dosimeters opens the possibility for in-house E2E testing. Approaches for in-house E2E testing have been proposed for over a decade, but such comprehensive internal E2E testing has not been widely adopted. In this presentation the barriers and challenges to the development of clinical in-house E2E QA will be reviewed primarily based on the experience in Kingston.
A chemical evolution of NVP-containing VIPAR-family 3D polymer gel dosimeters – a brief overview
Authors: Kozicki M , Jaszczak M , Maras P , Dudek M
Published: August 2019

NVP-containing three-dimensional polymer gel dosimeters for radiotherapy dosimetry have been developed for more than 20 years. There have been 11 main modifications of the originally proposed VIPAR polymer gel dosimeter that altogether have amounted to 12 gel dosimeter formulae. This communication is to summarise the main chemical changes made to the VIPAR dosimeter over these years of research. The newest NVP-polymer gel dosimeters are also introduced.
Regulation of land reallocation based on the preservation of the most valuable agricultural land
Authors: Nosov S I , Bondarev B E , Cherkashin K I
Published: August 2019

The analysis of different approaches to agricultural land reallocation implemented in several countries leads to the proof that the current methods of preserving valuable agricultural land in Russia are not effective and that the cancellation of compensation of agricultural production losses had led to some negative consequences. The authors developed a new methodology of allocation and preservation of the most valuable agricultural land and carried out calculations of their areas in all federal districts of the European part of the Russian Federation, which includes the most part of arable land in the country. Based on that was developed a new approach to land reallocation and economic regulation of that process.
Analysis of economic efficiency of livestock in the Republic of Tuva
Authors: Taibyl R S , Sevek V K , Sevek R M , Darzhaa Ch B
Published: August 2019

As thousands of years ago, now Tuvan arats-pastoralists keep seven types of livestock (sheep, goats, cows, horses, yaks, camels, deer), each of which takes a certain place in the diet of population. The natural areas of Tuva are perfect for transhumance. Reforms in the 1990s led to the collapse of state farms, in the absence of work in rural areas, the population engaged in the Tuvan traditional type of livestock breeding – transhumance, mainly sheep, goats and cattle of local breed. For a large number of the rural population of Tuva, animal husbandry has become a socially important and vital activity. Now there are more livestock in Tuva than during the industrialization of agriculture in Soviet times. However, Tuva has not developed an effective mechanism for the sale of livestock products and its further processing which would increase the income of shepherds’ families. For the first time on the basis of the complex analysis of animal husbandry in Tuva the structure of expenses and income of an average livestock farm is defined, also its economic efficiency is calculated. It was concluded that animal products, such as milk, wool and skin, economically viable in the Soviet period, currently do not generate income because of absence of organized animal products collection points, and the economic efficiency of livestock farms nowadays is achieved only through the production of ovine and bovine meat.
Ecological conditionality of population’s diseases
Authors: Danilova Z A
Published: August 2019

The purpose of this article is to study the impact of polluted atmospheric air on the morbidity and mortality rate of the population. The ecological conditionality of population’s diseases and mortality in the Russian Federation has been revealed. The regions of the Russian Federation were ranked into relatively ecologically “clean” and “polluted” areas, on the basis of which the significant difference in indicators of health and mortality of the population have been defined. In environmentally unfriendly areas, lower health outcomes and higher mortality rates have been noted. The correlation between emissions of solid particles, carbon and sulfur oxides, nitrogen dioxide and risks of cardiovascular system diseases, respiratory organs, congenital anomalies, neoplasms in the Russian Federation and the Baikal region has been calculated. In contrast to the country as a whole, the region has higher correlation coefficients of individual diseases and atmospheric pollution. A high degree of correlation between carbon monoxide emissions and diseases of the respiratory system, blood circulation and congenital anomalies in the Irkutsk region has been revealed. There is a positive correlation between emissions of solid particles and congenital anomalies in Buryatia.
The role of international infrastructure projects in sustainable social and economic development of the border areas (the case of Russia and Mongolia)
Authors: Sh Rygzynov T , Tsydypov V E
Published: August 2019

During the existence of the USSR, Mongolia was in the sphere of political and economic interests of Russia. On the one hand, the decrease of economic relations between Russia and Mongolia, and, on the other hand, the geographical proximity of Russia and China have made it necessary to search for new partners and sources of investment in mining, processing industry, energy and transport, service and tourism. The growing interest of foreign countries in Mongolia and presence of their representatives there undoubtedly speaks of the growing political and economic competition in the region. In the face of the current global geopolitical situation, growth of China’s influence in Mongolia’s economy and infrastructure projects being carrying out within the framework of the New Silk Road Concept, the role of border regions and cross-border interaction is growing. One way to increase the presence of other countries is by attracting investment or directly participating in the construction of new infrastructure facilities. The need to find ways of rational territorial organization of economic activities, using the potential of border areas, strengthening the infrastructure cooperation between the two countries determine the urgency of further research. A large amount of accumulated information on this subject of research and developed research methods, singled out comparable indicators of social and economic development of the regions of Russia and Mongolia allow for a qualitative, comprehensive study.
Global climate change: wild fires and permafrost degradation in the Republic of Buryatia (Eastern Siberia, Russia)
Authors: Badmaev Nimazhap , Bazarov Aleksandr , Kulikov Anatoly , Gyninova Ayur , Sympilova Darima , Shakhmatova Ekaterina , Badmaeva Natalya , Gonchikov Bato-Munko , Mangataev Aleksandr
Published: August 2019

On the territory of the Republic of Buryatia due to global climate change, significant transformations of the natural environment have been observed. Statistically significant trends of increase in temperature and decrease in precipitation with identification of wet and dry periods have been established. In the last 20 years due to the abnormally high air temperatures and the increasing aridity of the territory, the frequency and area of fires have increased, the rate of permafrost degradation on the southern boundary of the permafrost zone in the soils of meadow-steppe landscapes has increased twice.
Global warming and rational agricultural lands use in the Baikal Nature Territory
Authors: Ilyin Y M , Ayurzhanaev A A , Semenova M V , Sodnomov B V , Tsydypov B Z
Published: August 2019

A comparative assessment of moisture deficiency in the root zone of the soil based on its water properties has been made. The frequency of precipitation was determined. A reduction in the area of arable land with their transfer to deposits, hayfields and pastures has been proposed. It is shown that the risks of the agricultural sector need to be leveled by irrigated agriculture.
Chemical composition and water quality of the Baikal ecosystem in 2018
Authors: Grebenshchikova V I , Kuzmin M I , Yu Suslova M , Shtykova Yu R , Doroshkov A A
Published: August 2019

Analysis of the ion composition in the water of the Baikal ecosystem (Lake Baikal, the Angara River estuary and 35 tributaries) in the spring and autumn of 2018 has shown that the water from Baikal and the Angara estuary maintains low mineralization (94-98 mg/l) and corresponds to the calcium bicarbonate composition. The average chemical composition of the water from the Angara estuary is within the range of minimum-maximum values of the Baikal water. In the water from some tributaries, mineralization is two-three times higher compared to Baikal and the estuary. The average ion composition of the Baikal water intermediates in the range of minimum-maximum values of the studied tributaries. Microbiological studies have shown that the average number of hygiene indicator microorganisms in the water from the tributaries is much higher than in Baikal and the Angara estuary. Unlike the tributaries, the water from Baikal and the Angara estuary contain less number of organotrophic microorganisms. The most extensive Baikal tributaries, which drain the significant and status diverse (anthropogenic and natural) areas around Lake Baikal, definitely have a negative impact on the lake. However, many smaller rivers and streams flowing into Baikal, as well as horizontal and cyclonic currents existing in Baikal, preserve its status as the site with pure drinking water, but only in the pelagic zone of the lake.
Thermochemical decomposition of molybdenum concentrates with usage of magnesium-containing additives of natural origin
Authors: Khomoksonova D P , Budaeva A D , Antropova I G
Published: August 2019

This article presents the results of research on the sintering of molybdenite concentrate with magnesium-containing natural additives — brucite (Mg(OH)2) and magnesite (MgCO3). Physical and chemical properties of initial materials were studied. The thermodynamic assessment of the interaction of molybdenum with hydroxide and magnesium carbonate in an oxidizing medium is given. The process of thermochemical decomposition of molybdenum was optimized with usage of cheap magnesium-containing minerals to form molybdate and magnesium sulfate. The developed method makes it possible to reduce the cost of thermochemistry, to minimize the release of sulfur dioxide due to its rapid binding to magnesium sulfate.
Reduction of negative environmental impact of mechanisms by improving tribotechnical indicators of sealing materials
Authors: Kornopoltsev V N , Mognonov D M , Zh Ayurova O , Il’ina O V , Dashitsyrenova M S
Published: August 2019

In order to eliminate the negative environmental impact of transport and mechanisms operating under high speeds and loads, high abrasion wear, composite materials for sealing devices, thrust bearings, Goodrich stern bearings have been developed by the interaction of nitrile butadiene rubber with novolac resin, cured with dinitrile. The physico-mechanical and tribotechnical data of laboratory and production tests of the developed composites are shown.
Water disinfection by sonophotochemical method using persulfate
Authors: Tsenter I M , Garkusheva N M , Shirapova G S
Published: August 2019

The efficiency of water disinfection was investigated using advanced oxidation processes (AOPs) based on ultraviolet (UV) LEDs and high-frequency ultrasound (US) in the presence and absence of persulfate (PS). The hybrid oxidation system {UV+US+PS} was found to be the most effective for inactivating Enterococcus faecalis in a row: {UV+US+PS}>{UV+PS}>{UV+US}>{UV}>{US+PS}>{US}. The effect of US in this hybrid system for Escherichia coli was not observed and the systems {UV+US+PS} and {UV+PS} were equally effective. Complete inactivation (100%) of E. faecalis and E. coli by sonophotochemical method using PS was achieved after 10 - and 7-min treatment, respectively. We suppose that this method is promising for effective water disinfection.
Using the method of chemical dosimetry to evaluate the level of generation of active oxygen forms in advanced oxidation processes based on ultrasound
Authors: Aseev D G , Krasnekov D S
Published: August 2019

The widespread use of ultrasound is due to the diversity of phenomena occurring in an ultrasonic field. Ultrasonic vibrations initiate dispersion and emulsification of substances, contribute to coagulation and degassing, affect the processes of crystallization and dissolution. It is known that ultrasound causes various chemical transformations of a substance, including oxidation reactions, reduction, polymerization, etc. Research on the chemical effects of acoustic cavitation is an important task and for this, there are a large number of different chemical dosimeters of organic and inorganic nature. However, the proposed dosimeters have both advantages and disadvantages, including a long analysis time, high measurement errors, cost analysis, the use of expensive equipment. This work shows that the known substance butyl potassium dithiocarbonate can be used as a dosimeter of the effects of acoustic cavitation, in particular, high-frequency ultrasound 1.7 MHz, and has several advantages over the commonly used dosimeters. A large synergistic effect (2.26) was shown in the oxidation of dithiocarbonate from the combined effect of two directed at each other sources of ultrasound.
Effect of benzotriazolyl fragments on properties of thermoreactive benzotriazolylsuccinimides
Authors: Mognonov D M , Farion I A , Il’ina O V , Zh Ayurova O , Kornopol’tsev V N
Published: August 2019

An effect from the introduction of the benzotriazolyl fragments into the structure of thermoreactive resins based on benzotriazols and molar excesses of hexamethylene-bismaleimide was revealed. A change of thermal characteristics and improving mechanical properties and adhesion of the cured thermally glue layers to the surfaces of metallic samples made of Steel-3 were found. Such a conclusion was made from the data of the thermal analyzes and mechanical testes, when compared the samples made of both ‘pure’ hexamethylene-bismaleimide and the ones containing benzotriazolyl fragments.
Artemisia jacutica Drob. as the source of terpenoids
Authors: Dylenova E P , Randalova T E , Tykheev Zh A , Zhigzhitzhapova S V , Radnaeva L D
Published: August 2019

The object of research is Artemisia jacutica Drob. from Absinthium section, Asteracea family. The aerial part of A. jacutica was collected in Buryatia in 2017-2018. In this research we identified three types of terpenoid-containing structures: nonspecialized parenchyma cells with the inclusion of essential oils’ droplets, schizogenous intercellular space and essential oil glands. Also, we isolated the essential oil from the aerial part, and identified its component composition using GC-MS method. The dominant components were γ-eudesmol, chamazulene, neryl-3-methylbutanoate, neryl-isobutanoate and geranyl-3-methylbutanoate. Using IR-spectroscopy we made the screening of the sum of extractives for the presence of γ-lactones in water, ethanol and chloroform extracts. Then, the quantitative content of the total sum of sesquiterpene lactones from samples collected in 2017 and 2018 was 1.13±0.04 % and 1.05±0.07 %, respectively. More than that, we identified arglabin in CO2- and chloroform (1:10) extracts using HPLC-UV method. The extract yield was 0.79% and 2.39%, respectively. The yield of arglabin in these extracts was 0.001% and 1.15%, respectively.
Adsorption of Cr(VI) from aqueous solution by crosslinked cationic konjac glucomannan with different degree of substitution
Authors: Wang Pengyuan , Wang Ruolin , Liu Jianye , Niu Chunmei
Published: August 2019

Chromium has numerous industrial applications, such as metallurgy, processing of leather, producing chromic acid, acting as catalyst and electroplating. These activities cause Cr(VI) contamination in air, soil and water resources. Developing efficient and cost-effective adsorbents for removing Cr(VI) is of utmost importance. Crosslinked cationic konjac glucomannan (CCKGM) with different degrees of substitution (DS) 0.226, 0.391 and 0.456, were prepared by reaction of 3-chloro-2-hydroxypropyl-trimethyl ammonium chloride, konjac glucomannan (KGM) and epichlorohydrin and used to adsorb Cr(VI) ions from the aqueous solutions. Then the adsorption behaviour of CCKGM to Cr (VI) was explored. The adsorption effect of CCKGM on Cr(VI) is affected by pH, Cr(VI) initial concentration, adsorbent dose and temperature. With the increase of DS, adsorption capacity increased. The adsorption capacity was 31.52 mg/g, 58.82 mg/g and 62.59 mg/g corresponding to DS 0.226, 0.391 and 0.456, respectively. Adsorption can get equilibrium within several minutes and follows Langmuir isothermal adsorption. The process is exothermal and low temperature is favourable for adsorption. CCKGM has potential to be used as adsorbents for Cr (VI).
Romantic Poetry and the TV Series Form: The Rhyme of John Logan’s Penny Dreadful
Authors: Farizova Nina
Published: August 2019

The creator of the TV series Penny Dreadful John Logan has stated that he drew inspiration for the first three seasons (2014–16) from English Romantic poetry. Characters in the series read and recite Blake, Clare, Keats, Shelley, and Wordsworth; comment on the nature of poetry; and make emotional connections through poetic affinities. Simultaneously, the structure of the series is gradually revealed to the audience as a pattern of doublings and couplings, of mirrors and parallels—all of which can be associated with the poetic device of rhyme. Rhyming shapes the sensory and cognitive experiences of the audience of the series; it also reflects the order of the diegetic universe, be it a freakish correspondence of incongruous things or God’s plan. Since these aesthetic choices seem to be part of the creator’s highly self-conscious design, the series becomes an adaptation of Romantic poetry, not only directly using the historical Romantic texts, but re-enacting in its organization the epistemological practice that rhyme is for English poetry.
A-05 Gender differences in veterans referred for neuropsychological evaluation in an outpatient neuropsychology consultation service
Authors: Sullivan-Baca E , Naylon K , Zartman A , Ardolf B , Westhafer J
Published: August 2019

Objective

Women represent a growing population within the VA Healthcare System about which little is known from a neuropsychological perspective. The present study explored sex differences in veterans presenting for neuropsychological evaluation to delineate trends in demographics, referral questions, effort, and outcome diagnoses.

Method

A database derived from an outpatient neuropsychology clinic at a VA medical center spanning 2013 to 2019 was analyzed (n = 232 women/2642 men). Initial analyses explored demographic features of the full sample. Further analyses separated the sample into younger (n = 836 men, 155 women) and older adult (n = 1805 men, 77 women).

Results

Groups differed in age (t(1,2872) = 10.41, p < .001) and education (t(1,2830) = 6.68, p < .001). Men were older, less educated, and had greater vascular risk factors. In the younger group, men were more often referred for TBI (X2(1,1) = 7.27, p < .01) and women for multiple sclerosis (X2(1,1) = 13.56, p < .01). In the older group, men performed worse on effort measures (WMT IR: t(1,42.24) = 2.36, p < .05; WMT MC: t(1,327) = 2.57, p < .05; TOMM Trial 2: t(1,199) = 2.17, p < .05). Older women evidenced higher scores on GDS (t(1,43.04) = 2.94, p < .01) and were more commonly diagnosed with depression (X2(1,1) = 12.66, p < .01).

Conclusions

Sex differences in demographics, medical conditions, referral question, effort, and outcome diagnoses emerged in a large sample of veterans referred for outpatient neuropsychological assessment. These differences point to important diagnostic considerations for neuropsychologists in VA settings.
B-39 Is the Latent Structure of Neurocognitive Domains Invariant Across Males and Females with Schizophrenia?
Authors: Becker M , Allen D
Published: August 2019

Objective

Differences between males and females with schizophrenia have been identified for numerous important disorder-related variables including age of onset, severity, and course, among others. Evidence suggests there also may be differences in intellectual functioning and possibly specific cognitive deficits. This study examined differences in the latent structure of cognitive abilities between males and females with schizophrenia.

Method

Participants included 659 males (age X̄ = 38.25, 64.5% Caucasian, education X̄ = 11.69) and 209 females (age X̄ = 40.52, 55.5% Caucasian, education X̄ = 11.72) with schizophrenia who were evaluated with neuropsychological tests as part of a large multicenter randomized control trial of antipsychotic medications (CATIE). Confirmatory factor analysis (CFA) was used to test four competing models based on prior CFA of the CATIE data. Model accuracy was evaluated using Comparative Fit Index (CFI), Root Mean Squared Error of Approximation (RMSEA), and Akaike’s Information Criterion (AIC).

Results

CFAs were completed for each sex using EQS 6.3. Models included one-factor, five-factor, six-factor, and a hierarchical model in which five factors load on a single factor “g”. The six-factor model was the best fitting for both males and females.

Conclusions

The results indicated that a six-factor model of neurocognition is the best fitting model for both males and females. The results also suggest that the latent structure of cognitive abilities is similar for both sexes. This provides a strong basis for uniform interpretation of neuropsychological domains across males and females, although there may be sex-related differences in patterns and severity of deficit in each domain.
B-54 Insights into a Novel Integrated Screening Clinic: Parent Perceptions of Emotional Functioning in Acute Recovery Phase Following Pediatric Neurocritical Care
Authors: Bradbury K , Wagner A , Leonard S , Williams C , Piantino J , Luther M , Hall T
Published: August 2019

Objective

Children with traumatic brain injury (TBI) requiring neurocritical care are at high risk for neurocognitive, emotional, physical, and psychosocial difficulties, collectively known as Post-Intensive Care Syndrome. Our study sought to characterize parent ratings of emotional functioning in the acute recovery phase based upon mechanism of injury.

Method

Twenty children (Mdn = 12.6 years, IQR = 9-15; 65% male) were screened as part of a multidisciplinary follow-up clinic 1-month following hospital discharge. Emotional functioning was assessed using PROMIS Parent Proxy Report for Anxiety and Depression. A brief neurocognitive battery estimated presence of cognitive impairment. MANCOVA was used to compare emotional functioning across injury mechanism (high velocity injury [HVI], 65%; fall, 35%).

Results

Groups did not differ on age, gender, and presence of cognitive impairment. After controlling for severity, mechanism of injury had a significant effect on both anxiety (p = .026) and depression (p = .004). The HVI group had mildly elevated anxiety (M = 50.5, SD = 12.2) and depression (M = 54.2, SD = 10.6) scores, while the fall group had anxiety (M = 38.0, SD = 6.2) and depression (M = 39.0, SD = 7.3) scores within normal limits.

Conclusions

In the acute recovery phase following TBI, anxiety and depression symptoms are more common after HVI than falls, even when controlling for severity of injury. The HVI group includes injuries resulting from motor vehicle accidents which may have a broader impact on the family and may explain higher rates of emotional distress in this patient group compared to other mechanisms of TBI. Additional research is needed to further explore variables related to emotional functioning following TBI and how they change over the course of recovery.
B-58 Post-traumatic Stress Symptoms Are Associated with Worse Neuropsychological Functioning, but not Diffusion Tensor Imaging Findings, in Military Service Members Following Mild Traumatic Brain Injury.
Authors: Lange R , Lippa S , Brickell T , Yeh P , French L
Published: August 2019

Objective

The purpose of this study was to examine neurobehavioral and neurocognitive functioning, and white matter integrity (using Diffusion Tensor Imaging [DTI]), in service members with versus without PTSD following mild traumatic brain injury (MTBI).

Method

Participants were 101 U.S. military service members who had sustained an uncomplicated MTBI (n = 80) or an injury without TBI (i.e., Injured Control [IC], n = 21) prospectively enrolled from the Walter Reed National Military Medical Center (Bethesda, Maryland). Participants completed a battery of neuropsychological tests, as well as DTI of the brain, on average 4-years post-injury. Measures of FA, MD, AD, and RD were generated for 18 regions of interest [ROIs]. Participants in the MTBI group were divided into two sub-groups based on DSM-IV-TR diagnostic criteria for PTSD: MTBI/PTSD-Present (n = 22) and MTBI/PTSD-Absent (n = 58).

Results

The MTBI/PTSD-Present group reported a significantly higher number of postconcussion symptoms, had higher scores on the majority of MMPI-2-RF scales, and had worse scores on the vast majority of cognitive domains (i.e., Attention, Processing Speed, Immediate Memory, Delayed Memory, Executive Functioning, Visuospatial Ability) compared to both the MTBI/PTSD-Absent group (all p’s < .05) and IC/PTSD-Absent group (all p’s < .05). For the DTI variables, there were no significant group differences for all DTI measures in all regions of the brain, with the exception of a handful of measures (i.e., right cingulum–cingulate gyrus, and bilaterally in the corticospinal tract).

Conclusion

These results provide support for a (a) strong relationship between PTSD and poor neurobehavioral and neurocognitive outcome following MTBI, and (b) weak relationship between PTSD and white matter integrity following MTBI.
B-70 The Effect of Bilingualism on Trail Making Test Performance in Traumatic Brain Injury Survivors and Healthy Adults
Authors: Litvin P , Rugh-Fraser R , Lopez-Hernandez W , Knight J , Cervantes R , Bueno A , Arzuyan A , Rico M , Fatoorechi S , Mangassarian SHardy D , Vespa P , Plurad D , Hovda D , Woo E , Fuster J , Budding D , Wright M
Published: August 2019

Objective

Traumatic brain injury (TBI) is associated with a number of cognitive deficits. Language factors also impact neurocognitive performance. We examined the effects of TBI and bilingualism/monolingualism on a test of attention and executive functioning (Trail Making Test; TMT).

Method

The sample (N = 96) consisted of 36 healthy controls (19 bilingual; 17 monolingual), 34 acute TBI participants (12 bilingual; 21 monolingual), and 27 chronic TBI participants (16 bilingual; 11 monolingual). Acute TBI participants were tested 6 months post-injury and chronic TBI participants were tested 12 months or more post-injury. 3X2 ANOVAs were conducted to determine the effect of TBI and bilingualism/monolingualism on TMT part A and B.

Results

Main effects were found between groups (i.e., control and TBI groups) on TMT A, p < .001, ηp² = .17 and TMT B, p < .05, ηp² = .09. Pairwise comparisons revealed a difference only between the control group and the 6-month TBI group, with the latter performing worse. Main effects were found for bilingualism/monolingualism on TMT A, p < .05, ηp² = .04 and TMT B, p < .05, ηp² = .05; monolingual participants performed better than bilingual participants. No interactions emerged.

Conclusion

Relative to monolinguals, bilingual participants demonstrated worse attention and executive functioning performances 6 months post-TBI; however, 12 months post-TBI, the difference was negligible.