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Herein, the internal stress is regulated to enhance the electrocaloric effect (ECE) of the BaZr 0.2 Ti 0.8 O 3 -2 wt% LiCO 3 (2BLZT) thick films. The internal stress in 2BLZT thick films is inversely proportional to increased grain size. XRD Rietveld refinements reveal an increased fraction of ferroelectric R 3 m phase with the enlarged grain size, resulting in larger polarization and EC strength. A maximum Δ T of 1.88 K is achieved at 150 kV/cm. Furthermore, the 2BLZT ceramics with multilayer structure (2BLZT MLCs) are prepared, which can withstand a high field of 250 kV/cm and achieve a Δ T of 1.2 K. These performances are higher than that of 2BLZT bulks with the same effective working medium. Moreover, the required voltage to produce the same Δ T of 0.6 K is reduced from 1920 V for the bulks to 440 V for the MLCs. This work provides a strategy for designing high-ECE lead-free thick films and MLCs. [ABSTRACT FROM AUTHOR]

Background: In developing countries like India, cobalt-60 machines still find their applicability, considering the cost and maintenance issues. With a view to deliver conformal treatment plans using teletherapy machines, an automated Multi-Leaf Collimator (MLC) was developed for the existing machines as a retrofit attachment to the collimator assembly without any modifications to the unit. Objective: This study aims to investigate the radiation characteristics of leaf designs incorporated in two add-on prototype MLC systems with respect to the shape of leaf projected at the isocenter plane and the isodose distribution around the target. Besides, the dosimetric characteristics of prototype MLC with divergent leaf design are validated through simulation and experimental measurements.Material and Methods: In this experimental study, two add-on prototype MLC systems were designed and fabricated. The characteristic measurements of leaf designs incorporated in both the prototypes were carried out using Gafchromic films (GAF) and compared with Monte Carlo (MC) simulations. For divergent leaf design, beam profiles were obtained using Monte Carlo simulations which are complemented with the results obtained from measurements of radiochromic films and ionization chamber (IC) profiler. Dosimetric characteristics like radiation field width and beam penumbra were evaluated. Results: The Monte Carlo simulated data are in agreement with experimental data from IC profiler as well as from Radiochromic films. The results of this study are well within acceptable tolerance limits. Conclusion: The prototype MLC system designed for existing telecobalt machines supports its clinical applicability for conformal therapy to better manage treatment in rural areas, which can provide superior cost effective treatments.

Background: In developing countries like India, cobalt-60 machines still find their applicability, considering the cost and maintenance issues. With a view to deliver conformal treatment plans using teletherapy machines, an automated Multi-Leaf Collimator (MLC) was developed for the existing machines as a retrofit attachment to the collimator assembly without any modifications to the unit. Objective: This study aims to investigate the radiation characteristics of leaf designs incorporated in two add-on prototype MLC systems with respect to the shape of leaf projected at the isocenter plane and the isodose distribution around the target. Besides, the dosimetric characteristics of prototype MLC with divergent leaf design are validated through simulation and experimental measurements. Material and Methods: In this experimental study, two add-on prototype MLC systems were designed and fabricated. The characteristic measurements of leaf designs incorporated in both the prototypes were carried out using Gafchromic films (GAF) and compared with Monte Carlo (MC) simulations. For divergent leaf design, beam profiles were obtained using Monte Carlo simulations which are complemented with the results obtained from measurements of radiochromic films and ionization chamber (IC) profiler. Dosimetric characteristics like radiation field width and beam penumbra were evaluated. Results: The Monte Carlo simulated data are in agreement with experimental data from IC profiler as well as from Radiochromic films. The results of this study are well within acceptable tolerance limits. Conclusion: The prototype MLC system designed for existing telecobalt machines supports its clinical applicability for conformal therapy to better manage treatment in rural areas, which can provide superior cost effective treatments. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare 3D treatment plans implemented using 6 MV Linac with a retrofitted multileaf collimator (MLC) based cobalt-60 plans. In this retrospective study, DVH analysis was used to compare homogeneity of dose within the target and the dose received by critical organs. A prototype MLC designed and developed as a retrofit to current cobalt-60 teletherapy machines with a dedicated 3D treatment planning system was used. Cases representing 5 tumor sites like head & neck, glottis, lung, gall bladder, stomach were taken for the study, which were planned using Eclipse treatment planning system and treated with 6 MV photon beams. The plans were re-planned using the retrofit cobalt-60 MLC with same beam arrangement and dose prescription in Radiation Oncology planning system (ROPS). For each case, DVH data was evaluated for both types of beam energies. Conformity index (CI) and homogeneity index (HI) for target were calculated and compared. The conformal plans created using cobalt MLC for five sites were found to be similar to those planned using 6 MV photon beams. CI values close to unity reflected dose uniformity in the target volume while HI evaluated the hotspots in the target volume. It was concluded that plans created using retrofit prototype MLC developed for cobalt-60 teletherapy machines can provide dose distributions comparable to 6 MV photon beams. The prototype MLC developed can provide a promising treatment option for existing telecobalt machines in implementing conformal therapy in developing countries. [ABSTRACT FROM AUTHOR]

Generating cells with the molecular and functional properties of embryo cells and with full developmental potential is an aim with fundamental biological significance. Here we report the in vitro generation of mouse transient morula-like cells (MLCs) via the manipulation of signaling pathways. MLCs are molecularly distinct from embryonic stem cells (ESCs) and cluster instead with embryo 8- to 16-cell stage cells. A single MLC can generate a blastoid, and the efficiency increases to 80% when 8–10 MLCs are used. MLCs make embryoids directly, efficiently, and within 4 days. Transcriptomic analysis shows that day 4–5 MLC-derived embryoids contain the cell types found in natural embryos at early gastrulation. Furthermore, MLCs introduced into morulae segregate into epiblast (EPI), primitive endoderm (PrE), and trophectoderm (TE) fates in blastocyst chimeras and have a molecular signature indistinguishable from that of host embryo cells. These findings represent the generation of cells that are molecularly and functionally similar to the precursors of the first three cell lineages of the embryo. [Display omitted] • Stat3 activation induces the generation of transient morula-like cells (MLCs) • MLCs segregate rapidly into cells representing the first three embryo lineages • MLCs make embryoids directly and reach an early gastrulation-like stage within 4 days • MLCs have in vitro and in vivo embryonic and extraembryonic developmental potential Li et al. report that increased Stat3 activation reprograms mouse embryonic stem cells into cells with molecular and functional properties of morula. Such morula-like cells have in vitro and in vivo embryonic and extraembryonic developmental competence, suggesting that such cells may be precursor cells of the first three embryo lineages. [ABSTRACT FROM AUTHOR]

Abstract: Searching for the multiple longest common subsequences (MLCS) has found significant applications in the areas of bioinformatics, information processing, data mining, etc. There is a variety of MLCS algorithms, but none of the existing algorithms give effective solutions under the condition of a large alphabet, a considerable number of sequences and a long average length of sequences. Aiming at the defects of the MLCS algorithms available, this paper proposes a novel parallel algorithm for the MLCS—NMLCS based on the ideas of parallel processing and match pair by pre-processing. Experimental results show that our NMLCS resolves the problems mentioned above with great efficiency and significantly reduces time-space complexity as compared with other MLCS algorithms. [Copyright &y& Elsevier]

Mixed liver cell spheroids from rats consisting of hepatocytes and nonparenchymal cells lose three-dimensional structure and function when cultured on dishes. In order to maintain the configuration and function of the spheroids, we cultured them with collagen gel in various conditions, such as on the surface of collagen gel (group 2), between two collagen gel layers (group 3), and within collagen gel (group 4). Spheroids cultured on a standard collagen-coated dish were used as controls (group 1). Culture was continued for 10 days. Phase-contrast microscopy revealed that the spheroids of group 1 lost their spheroidal configuration and became a monolayer within 24 h. Group 2 spheroids also spread out to a monolayer, but thus occurred at 24 to 48h. In group 3, spheroid configuration was sustained until day 10, though slightly flattened. In group 4, the spheroid configuration was well maintained throughout the culture period. Urea synthesis of the spheroids cultured with collagen gel was significantly higher than in group 1 between days 1 and 3. Albumin synthesis of three experimental groups was also significantly higher than that of group 1. Although three experimental groups showed no difference in urea synthesis, albumin production by spheroids in groups 3 and 4 was better maintained than in group 2, even toward the end of the culture period. It is concluded that mixed liver-cell spheroid culture within collagen gels showed better maintenance of their configuration and function. [ABSTRACT FROM AUTHOR]