Verifying 4D gated radiotherapy using time-integrated electronic portal imaging: a phantom and clinical study

<p>Abstract</p> <p>Background</p> <p>Respiration-gated radiotherapy (RGRT) can decrease treatment toxicity by allowing for smaller treatment volumes for mobile tumors. RGRT is commonly performed using external surrogates of tumor motion. We describe the use of time-integrated electronic portal imaging (TI-EPI) to verify the position of internal structures during RGRT delivery</p> <p>Methods</p> <p>TI-EPI portals were generated by continuously collecting exit dose data (aSi500 EPID, Portal vision, Varian Medical Systems) when a respiratory motion phantom was irradiated during expiration, inspiration and free breathing phases. RGRT was delivered using the Varian RPM system, and grey value profile plots over a fixed trajectory were used to study object positions. Time-related positional information was derived by subtracting grey values from TI-EPI portals sharing the pixel matrix. TI-EPI portals were also collected in 2 patients undergoing RPM-triggered RGRT for a lung and hepatic tumor (with fiducial markers), and corresponding planning 4-dimensional CT (4DCT) scans were analyzed for motion amplitude.</p> <p>Results</p> <p>Integral grey values of phantom TI-EPI portals correlated well with mean object position in all respiratory phases. Cranio-caudal motion of internal structures ranged from 17.5–20.0 mm on planning 4DCT scans. TI-EPI of bronchial images reproduced with a mean value of 5.3 mm (1 SD 3.0 mm) located cranial to planned position. Mean hepatic fiducial markers reproduced with 3.2 mm (SD 2.2 mm) caudal to planned position. After bony alignment to exclude set-up errors, mean displacement in the two structures was 2.8 mm and 1.4 mm, respectively, and corresponding reproducibility in anatomy improved to 1.6 mm (1 SD).</p> <p>Conclusion</p> <p>TI-EPI appears to be a promising method for verifying delivery of RGRT. The RPM system was a good indirect surrogate of internal anatomy, but use of TI-EPI allowed for a direct link between anatomy and breathing patterns.</p

Production of food nanomaterials by specialized equipment

In the past decade, there has been a great interest in using nanotechnology by different industries, including food, pharmaceutical, and beauty. Nanotechnology provides many advantages to produce functional compounds which tend to be delivered for desired properties, such as protection from the environment or food matrix, controlled release, and increased bioavailability and bioaccessibility (Muhammad et al., 2019, Sedaghat Doost et al., 2019b, Sedaghat Doost et al., 2018c). There is a variety of methods to prepare food nanomaterials. Specialized equipment is frequently employed for the production of efficient nano-delivery systems, which is the focus of this chapter; the basic principle of conventional and recent techniques, as well as their advantages and disadvantages are described

A viewpoint on the gastrointestinal fate of cellulose nanocrystals

Background: Cellulose nanocrystalline (CNC) particles possess unique functional properties such as vastlymodifiable surface, considerable mechanical strength and acid resistance, as well as, high aspect ratio. CNCshave received great attention for application in diverse fields of technology including (composite) hydrogelsfabrication for the gastric protection and enteral delivery of drugs and nutraceuticals.Scope and approach: The orogastrointestinal digestibility and absorbability of the orally administered CNCs isoverviewed in the current article. At first, some surface charge-related characteristics of acid-isolated CNCs are communicated. Then, the biocompatibility and biodegradability of CNCs and CNC-reinforced hydrogels arereviewed, followed by presenting credible digestion and absorption scenarios. Finally, the post-absorptionmetabolism of CNCs is briefly debated.Key findings and conclusions: Bacterial cellulose shows good biocompatibility and hemocompatibility. CNCoxidation provides biologically beneficial impacts; for instance, the TEMPO- and periodate-oxidized CNCs have been shown to regulate some blood metabolic variables and improve the degradability in simulated human blood plasma, respectively. Spherical and carboxyl-bearing cellulose nanoparticles can be isolated through ammonium persulfate digestion. The sphericity of particles results in faster cellular uptake. Negatively-charged CNCs are non-mucoadhesive and thus upon ingestion can penetrate into the buccal and intestinal mucosa. One may augment the absorption of CNCs by targeted receptor-mediated endocytosis. It was postulated that sodium bicarbonate secretion into the duodenum can alter CNCs surface chemistry and influence CNC interaction with gut microbiot

The Adaptation Assessment of Different Sunflower Cultivars under Kabul Agro Climatic Conditions

Sunflower (Helianthus annuus L.) is one of the most important oilseeds crops due to its wide adaptability, mechanization potential, low labor requirements, and high oil and protein content. The present study was conducted to evaluate the performance of elite sunflower cultivars under Kabul agro-ecological conditions. The main objective of this research is to identify superior genotypes best adapted to Kabul agro-ecological conditions. Three improved cultivars of sunflowers, two from France (Robiacs and Imeriacs) and a local one were tested for two years, 2018-19, on the farm of Agriculture faculty at Kabul University. The experiment was arranged in a randomized complete block design (RCBD) with three replications. Data were collected on achene's yield and other parameters. Analysis revealed a highly significant difference among cultivars for all parameters under study except the number of days to complete emergence, number of plants m-2, plant height and leaf area index. Among the cultivars examined, there were significant differences in achene yield. Local cultivar (4696.92kg ha-1) followed by Robiacs (4346.62 kg ha-1) yielded significantly higher than Imeriacs cultivar (3029). These cultivars have shown to be the best local and exotic genotypes in terms of achene's yield. With additional tastings, these potential lines could be released for specific environments in Afghanistan similar to the Kabul agro-ecology

Production and properties of tragacanthin-conjugated lysozyme as a new multifunctional biopolymer

In this communication we describe preparation and characterization of an enzyme-biopolymer conjugate composed of water-soluble part of gum tragacanth and chicken egg white lysozyme (LZM) under mild Maillard reaction conditions. SDS-PAGE together with FT-IR spectroscopy revealed that Maillard reactions occurred between LZM and tragacanthin (TRG). Under optimum conditions (pH = 8.5, 60 degrees C, RH = 79%, 8 days), approximately 2 TRG molecules were attached to one LZM molecule. DSC analysis showed that conjugation with TRG increased denaturation temperature by 6.35 degrees C. The resulting conjugates were characterized using scanning electron microscopy. The modified enzyme activity retained 77% of the original enzymatic activity after 8 days. TRG-conjugated LZM exhibited improved solubility and emulsion properties as compared with the native LZM. In addition, a significant increase in foam capacity and stability of LZM-TRG conjugate was detected. Conjugate with TRG significantly improved the inhibitory effect of LZM on the growth of Staphylococcus aureus, Bacillus cereus, Escherichia coli and Salmonella typhi in a dose dependent manner such that at 4000 mu g/ml, LZM-TRG conjugate inhibited S. aureus, Bacillus cereus, Escherichia coli and Salmonella typhi by 90%, 80%, 50% and 40%, respectively. Taken together these results suggest that the functional properties and antimicrobial activities of LZM can be improved by conjugation with TRG. The conjugation might expand the applications of LZM as a multifunctional ingredient in food and pharmaceutical industries

Short-term and long-term reproducibility of lung tumor position using active breathing control (ABC).

PURPOSE: To evaluate the short-term and long-term reproducibility of lung tumor position for scans acquired using an active breathing control (ABC) device. METHODS AND MATERIALS: Ten patients with lung cancer were scanned over three sessions during the course of treatment. For each session, two scans were acquired at deep inhale, and one scan each at half of deep inhale and at exhale. Long-term reproducibility was evaluated by comparing the same breathing state scans from two sessions, with setup variation removed by skeletal alignment. Tumor alignment was based on intensity matching of a small volume around the tumor. For short-term reproducibility, the two inhale volumes from the same session were compared. RESULTS: For the short-term reproducibility, the mean and the standard deviation (SD) of the displacement of the center of tumor were 0.0 (1.5) mm in anteroposterior (AP), 0.3 (1.4) mm in superior/inferior (SI), and 0.2 (0.7) mm in right/left (RL) directions. For long-term reproducibility, the mean (SD) were -1.3 (3.1) mm AP, -0.5 (3.8) mm SI, and 0.3 (1.6) mm RL for inhale and -0.2 (2.8) mm AP, 0.2 (2.1) mm SI, and -0.7 (1.1) mm RL for exhale. CONCLUSION: The ABC device demonstrates very good short-term and long-term reproducibility. Increased long-term variability in position, primarily in the SI and AP directions, indicates the role of tumor-directed localization in combination with breath-held immobilizatio