Prism Architecture Research Articles

A novel image processing procedure for the quantitative evaluation of dental enamel prism arrangement.

Enamel prism is the main microstructural unit of mammalian enamel which composed of hundreds of bioapatite nanocrystals. Prism structure plays a key role in the excellent mechanical performance of dental enamel during millions of chewing cycles without significant remodeling. Thus, quantitative understanding of prism architecture is of utmost importance for biomechanical materials design. To characterize enamel prism orientation quantitatively, a novel image processing method has been developed. Our method is based on scanning electron microscopy images of etched enamel surface and consists of an ellipse fitting procedure, which provides a numerical approximation of prism shape and orientation in the studied cross section. The obtained analytical data allow to construct color coded orientation maps, which provide quick and useful insight into the microstructure of enamel. Besides striking visualization, orientation maps allow to extract and plot the rich information on the azimuthal and inclination angles of the prisms as function of location. Numerical data on prism arrangement can be analyzed using statistical tools over large areas, which paves the way towards quantifying comparative investigation of prism arrangement either in dentistry research or evolution biology. The application of the method is demonstrated for a distal-mesial cross-section of sound human tooth enamel. HIGHLIGHTS: Scanning electron microscopy images of etched enamel surface are analyzed using ellipse fitting. Geometrical parameters of the fitted ellipses provide numerical data of thousands of prisms. Prism arrangement is visualized on color coded orientation maps and analyzed using statistical tools.

Reviewing topics of COVID-19 news articles: case study of CNN and China daily

PurposeThe purpose of this study is to analyze the topics of COVID-19 news articles for better obtaining the relationship among and the evolution of news topics, helping to manage the infodemic from a quantified perspective.Design/methodology/approachTo analyze COVID-19 news articles explicitly, this paper proposes a prism architecture. Based on epidemic-related news on China Daily and CNN, this paper identifies the topics of the two news agencies, elucidates the relationship between and amongst these topics, tracks topic changes as the epidemic progresses and presents the results visually and compellingly.FindingsThe analysis results show that CNN has a more concentrated distribution of topics than China Daily, with the former focusing on government-related information, and the latter on medical. Besides, the pandemic has had a big impact on CNN and China Daily's reporting preference. The evolution analysis of news topics indicates that the dynamic changes of topics have a strong relationship with the pandemic process.Originality/valueThis paper offers novel perspectives to review the topics of COVID-19 news articles and provide new understandings of news articles during the initial outbreak. The analysis results expand the scope of infodemic-related studies.

Lithium-Rich Layered Oxide with a Porous Prism Architecture for High-Performance Cathode Materials of Lithium-Ion Batteries

Lithium-rich layered oxides are among the most promising cathode materials for high-energy-density lithium-ion batteries (LIBs). Besides the composition and structure, the morphology of Li-rich layered materials also has significant effects on their electrochemical performance. In this work, a porous prism architecture of Li1.2Mn0.54Ni0.13Co0.13O2 materials is constructed via a coprecipitation solvothermal method and subsequent heat treatment. Appropriate concentrations of transition metal ions and oxalic acid as the precipitant used in synthesis govern the growth of the porous prism structure. When employed as a cathode material for LIBs, the optimized material achieves a high initial discharge capacity of 295.3 mAh g–1 at 0.1C and excellent rate capability of 150.6 mAh g–1 even at 5.0C. These outstanding performances can be attributed to the synergistic effect of the porous morphology and one-dimensional prism architecture. In particular, the porous morphology promotes the intercalation and extraction of Li+ while the prism architecture is associated with the observed superior structural stability. This architecture opens a promising avenue for the development of high-performance cathode materials in LIBs.

Exploration of carbohydrate binding behavior and anti-proliferative activities of Arisaema tortuosum lectin

BackgroundLectins have come a long way from being identified as proteins that agglutinate cells to promising therapeutic agents in modern medicine. Through their specific binding property, they have proven to be anti-cancer, anti-insect, anti-viral agents without affecting the non-target cells. The Arisaema tortuosum lectin (ATL) is a known anti-insect and anti-cancer candidate, also has interesting physical properties. In the present work, its carbohydrate binding behavior is investigated in detail, along with its anti-proliferative property.ResultsThe microcalorimetry of ATL with a complex glycoprotein asialofetuin demonstrated trivalency contributed by multiple binding sites and enthalpically driven spontaneous association. The complex sugar specificity of ATL towards multiple sugars was also demonstrated in glycan array analysis in which the trimannosyl pentasaccharide core N-glycan [Manα1-6(Manα1-3)Manβ1-4GlcNAcβ1-4GlcNAcβ] was the highest binding motif. The high binding glycans for ATL were high mannans, complex N-glycans, core fucosylated N-glycans and glycans with terminal lactosamine units attached to pentasaccharide core. ATL induced cell death in IMR-32 cells was observed as time dependent loss in cell number, formation of apoptotic bodies and DNA damage. As a first report of molecular cloning of ATL, the in silico analysis of its cDNA revealed ATL to be a β-sheet rich heterotetramer. A homology model of ATL showed beta prism architecture in each monomer with 85% residues in favoured region of Ramachandran plot.ConclusionsDetailed exploration of carbohydrate binding behavior indicated ATL specificity towards complex glycans, while no binding to simple sugars, including mannose. Sequence analysis of ATL cDNA revealed that during the tandem evolutionary events, domain duplication and mutations lead to the loss of mannose specificity, acquiring of new sugar specificity towards complex sugars. It also resulted in the formation of a two-domain single chain polypeptide with both domains having different binding sites due to mutations within the consensus carbohydrate recognition sites [QXDXNXVXY]. This unique sugar specificity can account for its significant biological properties. Overall finding of present work signifies anti-cancer, anti-insect and anti-viral potential of ATL making it an interesting molecule for future research and/or theragnostic applications.

Increasing light capture in silicon solar cells with encapsulants incorporating air prisms to reduce metallic contact losses.

Silicon solar cells are the most widely deployed modules owing to their low-cost manufacture, large market, and suitable efficiencies for residential and commercial use. Methods to increase their solar energy collection must be easily integrated into module fabrication. We perform a theoretical and experimental study on the light collection properties of an encapsulant that incorporates a periodic array of air prisms, which overlay the metallic front contacts of silicon solar cells. We show that the light collection efficiency induced by the encapsulant depends on both the shape of the prisms and angle of incidence of incoming light. We elucidate the changes in collection efficiency in terms of the ray paths and reflection mechanisms in the encapsulant. We fabricated the encapsulant from a commercial silicone and studied the change in the external quantum efficiency (EQE) on an encapsulated, standard silicon solar cell. We observe efficiency enhancements, as compared to a uniform encapsulant, over the visible to near infrared region for a range of incident angles. This work demonstrates exactly how a periodic air prism architecture increases light collection, and how it may be designed to maximize light collection over the widest range of incident angles.

Intrinsically Disordered Mollusk Shell Prismatic Protein That Modulates Calcium Carbonate Crystal Growth

The formation of calcite prism architecture in the prismatic layer of the mollusk shell involves the participation of a number of different proteins. One protein family, Asprich, has been identified as a participant in amorphous calcium carbonate stabilization and calcite architecture in the prismatic layer of the mollusk, Atrina rigida . However, the functional role(s) of this protein family are not fully understood due to the fact that insufficient quantities of these proteins are available for experimentation. To overcome this problem, we employed stepwise solid-phase synthesis to recreate one of the 10 members of the Asprich family, the 61 AA single chain protein, Asprich "3". We find that the Asprich "3" protein inhibits the formation of rhombohedral calcite crystals and induces the formation of round calcium carbonate deposits in vitro that contain calcite and amorphous calcium carbonate (ACC). This mineralization behavior does not occur under control conditions, and the formation of ACC and calcite is similar to that reported for the recombinant form of the Asprich "g" protein. Circular dichroism studies reveal that Asprich "3" is an intrinsically disordered protein, predominantly random coil (66%), with 20-30% β-strand content, a small percentage of β-turn, and little if any α-helical content. This protein is not extrinsically stabilized by Ca(II) ions but can be stabilized by 2,2,2-trifluoroethanol to form a structure consisting of turn-like and random coil characteristics. This finding suggests that Asprich "3" may require other extrinsic interactions (i.e., with mineral or ionic clusters or other macromolecules) to achieve folding. In conclusion, Asprich "3" possesses in vitro functional and structural qualities that are similar to other reported for other Asprich protein sequences.

Error Resilience in Current Distributed Video Coding Architectures

In distributed video coding the signal prediction is shifted at the decoder side, giving therefore most of the computational complexity burden at the receiver. Moreover, since no prediction loop exists before transmission, an intrinsic robustness to transmission errors has been claimed. This work evaluates and compares the error resilience performance of two distributed video coding architectures. In particular, we have considered a video codec based on the Stanford architecture (DISCOVER codec) and a video codec based on the PRISM architecture. Specifically, an accurate temporal and rate/distortion based evaluation of the effects of the transmission errors for both the considered DVC architectures has been performed and discussed. These approaches have been also compared with H.264/AVC, in both cases of no error protection, and simple FEC error protection. Our evaluations have highlighted in all cases a strong dependence of the behavior of the various codecs to the content of the considered video sequence. In particular, PRISM seems to be particularly well suited for low-motion sequences, whereas DISCOVER provides better performance in the other cases.

Active deformation across the Sumatran forearc over the December 2004 Mw9.2 rupture

A 220-km-long, single-channel seismic reflection profile crosses the northern Sumatra margin and presumed rupture zone of the December 2004 M w 9.2 tsunamigenic earthquake and images active deformation across the forearc. At the largest wavelength (tens of kilometers), the forearc surface is defined by a steep, 55-km-wide outer slope, a 110-km-wide upper slope forming a broad depression between two forearc highs, and a 25-km-wide steep inner slope between the landward high and forearc basin. Superimposed on these prism-wide variations are anticlinal ridges spaced ∼13 km apart; the inner and outer slopes are characterized by landward and seaward fold vergence, respectively. Between anticlines, growth strata deposited in slope basins are folded at ∼2–3 km wavelengths. These small folds deform the seafloor and increase in amplitude with depth, verging toward anticlinal hinges. We suggest that long-wavelength variations are consistent with variations in strength across the forearc. The ∼13 km anticline spacing implies deformation of a slope apron that deforms independently of a stronger wedge interior. Growth strata geometries indicate ongoing deformation within individual basins. Our model for prism architecture suggests that the wedge interior advances during great earthquakes like the 2004 M w 9.2 event, peeling up shallower and less competent trench fill, deforming the toe and the upper slope of the forearc, and producing seabottom uplift responsible for the tsunami.

Three‐dimensional architecture of the Nankai accretionary prism's imbricate thrust zone off Cape Muroto, Japan: Prism reconstruction via en echelon thrust propagation

A 9 km wide, 92 km long, three‐dimensional (3‐D) seismic reflection volume acquired off Shikoku Island, Japan, images the seaward portion of the subduction of the Philippine Sea plate at the Nankai Trough and Nankai accretionary prism. Detailed interpretation of the imbricate thrust and protothrust zones, the portions of the prism between the deformation front and the first out‐of‐sequence thrust, shows a high degree of variability in the thrust faults that all parallel the frontal thrust but are arranged in en echelon patterns along strike and frequently include complications such as piggyback faults and fault splays. Interestingly, the sinuous seafloor morphology of the prism does not accurately reflect the en echelon 3‐D architecture of the primary prism thrusts. Seafloor morphology appears to average across several thrusts along strike and is further modified by near‐surface thrust splays and backthrusts, suggesting that care must be taken in interpreting seafloor relief in terms of lateral continuity or thrust fault geometry. Subduction of the Kinan seamounts 20 km northeast of the center of the Muroto 3‐D volume generated a scallop‐shaped embayment in the prism; the rebuilding process appears to influence the northeastern portion of the 3‐D volume where a ∼625 m landward step in the position of the frontal thrust and numerous changes in prism architecture are observed. These observations imply that accretionary prisms may reattain equilibrium following seamount subduction by lateral en echelon fault propagation into damaged zones that facilitate an increase accretion rate until a laterally continuous deformation front is reestablished.

Enhanced streaming services in a content distribution network

Prism's content naming, management, discovery, and redirection mechanisms support: high-quality streaming media services in an IP-based content distribution network. IP content distribution networks (CDNs) are special-purpose networks that provide scalability by distributing many servers across the Internet close to consumers. Prism (Portal infrastructure for Streaming Media) is a CDN architecture for: distributing, storing, and delivering high quality streaming media over IP networks. The Prism-based stored-TV (STV) service allows users to select content based on the program's name as well as the time it was aired. Content stored inside the network is accessible throughout the whole Prism infrastructure. For example, a user in the US can access European TV content both live and on-demand. Prism also allows users to specify content to be stored in a network-VCR type service. The authors introduce the components of the Prism architecture.