4,135 research outputs found
Optimal synthesis of multivalued quantum circuit
Although many of works have been done in multivalued quantum logic synthesis,
the question whether multivalued quantum circuits are more efficient than the
conventional binary quantum circuits is still open. In this article we devote
to the optimization of generic multivalued quantum circuits. The multivalued
quantum Shannon decompositions (QSD) are improved so that the circuits obtained
are asymptotically optimal for all dimensionality d. The syntheses of uniformly
multifold controlled rotations are also optimized to make the circuits
further simplified. Moreover, the theoretical lower bound of complexity for
multivalued quantum circuits is investigated, and a quantity known as
efficiency index is proposed to evaluate the efficiency of synthesis of various
quantum circuits. The algorithm for qudit circuits given here is an efficient
synthesis routine which produces best known results for all dimensionality d,
and for both cases the number of qudit n is small and that is asymptotic. The
multivalued quantum circuits are indeed more efficient than the binary quantum
circuits. The facts, the leading factor of the lower bound of complexity for
qudit circuits is small by a factor of d-1 in comparison to that for qubit
circuits and the asymptotic efficiency index is increased with the increase of
dimensionality d, reveal the potential advantage of qudit circuits over generic
qubit circuits. The generic n-qudit circuits with and generic
two-ququart circuits synthesized by the algorithm given here are practical
circuits which are more efficient than the most efficient qubit circuits.Comment: 7 pages, 2 figures, 6 table
Systematics of g factors of 2_1^+ states in even-even nuclei from Gd to Pt: A microscopic description by the projected shell model
The systematics of g factor of first excited 2^+ state vs neutron number N is
studied by the projected shell model. The study covers the even-even nuclei of
all isotopic chains from Gd to Pt. g factors are calculated by using the
many-body wavefunctions that reproduces well the energy levels and B(E2)'s of
the ground-state bands. For Gd to W isotopes the characteristic feature of the
g factor data along an isotopic chain is described by the present model.
Deficiency of the model in the g factor description for the heavier Os and Pt
isotopes is discussed.Comment: 9 pages, 5 figure
Structure and mechanism of human DNA polymerase η
The variant form of the human syndrome xeroderma pigmentosum (XPV) is caused by a deficiency in DNA polymerase eta (Pol eta), a DNA polymerase that enables replication through ultraviolet-induced pyrimidine dimers. Here we report high-resolution crystal structures of human Pol eta at four consecutive steps during DNA synthesis through cis-syn cyclobutane thymine dimers. Pol eta acts like a 'molecular splint' to stabilize damaged DNA in a normal B-form conformation. An enlarged active site accommodates the thymine dimer with excellent stereochemistry for two-metal ion catalysis. Two residues conserved among Pol eta orthologues form specific hydrogen bonds with the lesion and the incoming nucleotide to assist translesion synthesis. On the basis of the structures, eight Pol eta missense mutations causing XPV can be rationalized as undermining the molecular splint or perturbing the active-site alignment. The structures also provide an insight into the role of Pol eta in replicating through D loop and DNA fragile sites
Decoding BIM Adoption: A Meta-Analysis of 10 Years of Research—Exploring the Influence of Sample Size, Economic Level, and National Culture
In recent years, some studies have explored the determinants of Building Information Modeling (BIM) adoption. However, the findings of these studies are varied and sometimes contradicting. Consequently, this study undertakes an in-depth exploration of the relationship between influencing factors and behavioral intention. This analysis is achieved through a synthesis of findings from prior empirical studies, considering the nuanced impacts of specific contextual factors, including sample size, national culture, and economic level, on these relationships. In total, this meta-analysis encompasses 57 articles, and as of 31 December 2023, incorporates 63 datasets comprising a collective sample size of 13,301. An extended Unified Theory of Acceptance and Use of Technology (UTAUT) model was developed based on the most frequently studied constructs relevant to BIM adoption. The analysis reveals that BIM adoption is primarily affected by performance expectancy, social influence, facilitating conditions, effort expectancy, and perceived value. The moderator analysis indicates that sample size statistically significantly moderates the relationships between facilitating conditions and use behavior. Moreover, the extent of individualism in each national culture significantly moderates the associations between facilitating conditions and user behavior. The research serves to enrich the existing body of literature on BIM acceptance by addressing contradictory and mixed results found in empirical studies. It represents one of the first attempts to explore the influence of sample size, economic level, and Hofstede’s six cultural dimensions as moderators in the field of BIM utilizing meta-analytic techniques.</jats:p
Germanium-lead perovskite light-emitting diodes.
Reducing environmental impact is a key challenge for perovskite optoelectronics, as most high-performance devices are based on potentially toxic lead-halide perovskites. For photovoltaic solar cells, tin-lead (Sn-Pb) perovskite materials provide a promising solution for reducing toxicity. However, Sn-Pb perovskites typically exhibit low luminescence efficiencies, and are not ideal for light-emitting applications. Here we demonstrate highly luminescent germanium-lead (Ge-Pb) perovskite films with photoluminescence quantum efficiencies (PLQEs) of up to ~71%, showing a considerable relative improvement of ~34% over similarly prepared Ge-free, Pb-based perovskite films. In our initial demonstration of Ge-Pb perovskite LEDs, we achieve external quantum efficiencies (EQEs) of up to ~13.1% at high brightness (~1900 cd m-2), a step forward for reduced-toxicity perovskite LEDs. Our findings offer a new solution for developing eco-friendly light-emitting technologies based on perovskite semiconductors
Long Non-Coding RNA CYP4B1-PS1-001 Inhibits Proliferation and Fibrosis in Diabetic Nephropathy by Interacting with Nucleolin
Background/Aims: Our previous studies demonstrated that a novel long non-coding RNA, CYP4B1-PS1-001, was significantly downregulated in early diabetic nephropathy in vivo and in vitro, and CYP4B1-PS1-001 overexpression could inhibit the proliferation and fibrosis of mouse mesangial cells (MMCs). However, the underlying mechanism of the CYP4B1-PS1-001-mediated regulation of proliferation and fibrosis in diabetic nephropathy remains undetermined. Methods: RNA-protein pull-down assay, RNA-binding protein immunoprecipitation, and mass spectrometry were used to investigate CYP4B1-PS1-001 interacted with the upregulated protein nucleolin (NCL). siRNA method was applied to knockdown NCL in MMCs, the interaction between CYP4B1-PS1-001 and NCL were determined by Western blot analysis and RT-qPCR. The effect of CYP4B1-PS1-001 in the regulation of NCL was detected by cycloheximide (CHX) and ubiquitination assays. Results: We found that CYP4B1-PS1-001 interacts with NCL, and CYP4B1-PS1-001 inhibits the proliferation and fibrosis of MMCs depending on interaction with NCL. Furthermore, degradation of CYP4B1-PS1-001-associated NCL was mediated by a ubiquitin proteasome-dependent pathway. Conclusion: Our study provides evidence that CYP4B1-PS1-001 regulates the ubiquitination and degradation of NCL and thereby plays a critical role in the proliferation and fibrosis of MMCs, indicating that CYP4B1-PS1-001 and NCL may be promising prognostic biomarkers and molecular targets for the treatment of diabetic nephropathy
Approaches in biotechnological applications of natural polymers
Natural polymers, such as gums and mucilage, are biocompatible, cheap, easily available and non-toxic materials of native origin. These polymers are increasingly preferred over synthetic materials for industrial applications due to their intrinsic properties, as well as they are considered alternative sources of raw materials since they present characteristics of sustainability, biodegradability and biosafety. As definition, gums and mucilages are polysaccharides or complex carbohydrates consisting of one or more monosaccharides or their derivatives linked in bewildering variety of linkages and structures. Natural gums are considered polysaccharides naturally occurring in varieties of plant seeds and exudates, tree or shrub exudates, seaweed extracts, fungi, bacteria, and animal sources. Water-soluble gums, also known as hydrocolloids, are considered exudates and are pathological products; therefore, they do not form a part of cell wall. On the other hand, mucilages are part of cell and physiological products. It is important to highlight that gums represent the largest amounts of polymer materials derived from plants. Gums have enormously large and broad applications in both food and non-food industries, being commonly used as thickening, binding, emulsifying, suspending, stabilizing agents and matrices for drug release in pharmaceutical and cosmetic industries. In the food industry, their gelling properties and the ability to mold edible films and coatings are extensively studied. The use of gums depends on the intrinsic properties that they provide, often at costs below those of synthetic polymers. For upgrading the value of gums, they are being processed into various forms, including the most recent nanomaterials, for various biotechnological applications. Thus, the main natural polymers including galactomannans, cellulose, chitin, agar, carrageenan, alginate, cashew gum, pectin and starch, in addition to the current researches about them are reviewed in this article.. }To the Conselho Nacional de Desenvolvimento Cientfíico e Tecnológico (CNPq) for fellowships (LCBBC and MGCC) and the Coordenação de Aperfeiçoamento de Pessoal de Nvíel Superior (CAPES) (PBSA). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and COMPETE 2020 (POCI-01-0145-FEDER-006684) (JAT)
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