Plasmonic metasurfaces, which can be considered as the two-dimensional analog of metal-based metamaterials, have attracted progressively increasing attention in recent years because of the ease of ...fabrication and unprecedented control over the reflected or transmitted light while featuring relatively low losses even at optical wavelengths. Among all the different design approaches, gap-surface plasmon metasurfaces – a specific branch of plasmonic metasurfaces – which consist of a subwavelength thin dielectric spacer sandwiched between an optically thick metal film and arrays of metal subwavelength elements arranged in a strictly or quasi-periodic fashion, have gained awareness from researchers working at practically any frequency regime as its realization only requires a single lithographic step, yet with the possibility to fully control the amplitude, phase, and polarization of the reflected light. In this paper, we review the fundamentals, recent developments, and opportunities of gap-surface plasmon metasurfaces. Starting with introducing the concept of gap-surface plasmon metasurfaces, we present three typical gap-surface plasmon resonators, introduce generalized Snell’s law, and explain the concept of Pancharatnam-Berry phase. We then overview the main applications of gap-surface plasmon metasurfaces, including beam-steerers, flat lenses, holograms, absorbers, color printing, polarization control, surface wave couplers, and dynamically reconfigurable metasurfaces. The review is ended with a short summary and outlook on possible future developments.
Molecular basis of protein stability at different temperatures is a fundamental problem in protein science that is substantially far from being accurately and quantitatively solved as it requires an ...explicit knowledge of the temperature dependence of folding free energy of amino acid residues. In the present study, we attempted to gain insights into the thermodynamic stability of SazCA and its implications on protein folding/unfolding. We report molecular dynamics simulations of water solvated SazCA in a temperature range of 293-393 K to study the relationship between the thermostability and flexibility. Our structural analysis shows that the protein maintains the highest structural stability at 353 K and the protein conformations are highly flexible at temperatures above 353 K. Larger exposure of hydrophobic surface residues to the solvent medium for conformations beyond 353 K were identified from H-bond analysis. Higher number of secondary structure contents exhibited by SazCA at 353 K corroborated the conformations at 353 K to exhibit the highest thermal stability. The analysis of thermodynamics of protein stability revealed that the conformations that denature at higher melting temperatures tend to have greater maximum thermal stability. Our analysis shows that 353 K conformations have the highest melting temperature, which was found to be close to the experimental optimum temperature. The enhanced protein stability at 353 K due the least value of heat capacity at unfolding suggested an increase in folding. Comparative Gibbs free energy analysis and funnel shaped energy landscape confirmed a transition in folding/unfolding pathway of SazCA at 353 K.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Fiber hybridization consisted of simultaneous use of steel and polymer (PVA) fibers.•Polymer fibers melt at high temperatures, creating pathways for release of water.•Steel fibers remain intact at ...high temperatures, bridging cracks.•Hybridization significantly improved mechanical performance at high temperatures.
Recent studies have shown improved mechanical performance of Fiber-Reinforced Concretes (FRC) compared to conventional concrete at high temperatures. While polymer fibers in FRC improve the compressive behavior by providing pathways for moisture to escape through melting of fibers at high temperatures, steel fibers in FRC improve the tensile behavior through crack-bridging at high temperatures. The goal of this research is to investigate the influence of utilizing both polymer and steel fibers in a single FRC for improving compressive and tensile properties at high temperatures, simultaneously. For this purpose, a Polyvinyl Alcohol (PVA)-steel Hybrid Fiber-Reinforced Strain Hardening Cementitious Composite (HFR-SHCC) was developed. SHCC is a special class of FRC with strain-hardening behavior under direct uniaxial tension. The residual compressive and tensile properties of HFR-SHCC after being subjected to temperatures of up to 800 °C were experimentally determined. Additional FRCs, including a conventional SHCC with only PVA fibers and a fiber-reinforced concrete with only steel fibers (steel FRC), as well as conventional concretes of two different compressive strengths were tested with the same protocol for a comprehensive comparison. The HFR-SHCC shows clear improvement over conventional SHCC, steel FRC and conventional concretes in terms of residual tensile strength after exposure to high temperatures, while simultaneously retaining the benefits of conventional SHCC, which include high tensile strain capacity and microscopic crack widths at normal temperatures and improved retention of compressive strength after exposure to high temperature.
•Extracellular, intracellular and total antibiotic resistance genes (ARGs) studied.•Two metagenomics pipelines compared for ARG-host assignment.•Sediment microbial community similar for iDNA and ...total DNA vs. eDNA.•ARGs associated with MGEs increased in downstream sites for iDNA.•Putative pathogenic ARG hosts identified via both pipelines.
Human health risk assessment for environmental antibiotic resistant microbes requires not only quantifying the abundance of antibiotic resistance genes (ARGs) in environmental matrices, but also understanding their hosts and genetic context. Further, differentiating ARGs in intracellular and extracellular DNA (iDNA and eDNA) fractions may help refine our understanding of ARG transferability. The objectives of this study were to understand the (O1) abundance and diversity of extracellular, intracellular, and total ARGs along a land use gradient and (O2) impact of bioinformatics pipeline on the assignment of putative hosts for the ARGs observed in the different DNA fractions. Sediment samples were collected along a land use gradient in the Raritan River, New Jersey, USA. DNA was extracted to separate eDNA and iDNA and qPCR was performed for select ARGs and the 16S rRNA gene. Shotgun metagenomic sequencing was performed on DNA extracts for the different DNA fractions. ARG hosts were assigned via two different bioinformatic pipelines: network analysis of raw reads versus assembly. Results of the two pipelines were compared to evaluate their performance in terms of number and diversity of linkages and accuracy of in silico matrix spike host assignments. No differences were observed in the 16S rRNA gene normalized sul1 concentrations between the DNA fractions. The overall microbial community structure was more similar for iDNA and total DNA compared to eDNA and generally clustered by sampling site. ARGs associated with mobile genetic elements increased in iDNA for the downstream sites. Regarding host assignment, the raw reads pipeline via network analysis identified 247 ARG hosts as compared to 53 hosts identified by assembly pipeline. Other comparisons between the pipelines were made including ARG assignment to taxa containing waterborne pathogens and practical considerations regarding processing time.
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The composite ceramic electrolyte CeO2 containing Li6.6La3Zr1.6Sb0.4O12 been prepared by solid state reaction method. Effect of CeO2addition on the structure, density and ionic conductivity of ...Li6.6La3Zr1.6Sb0.4O12 electrolyte has been studied. The cubic garnet phase of LLZO has been confirmed from XRD analysis. SEM analysis has been carried out for morphological study and elemental distribution in the sample. Complex impedance analysis has been carried out with ac conductivity measurements and modulus studies. Addition of 2 wt% CeO2 in Li6.6La3Zr1.6Sb0.4O12 enhances the ionic conductivity by half an order of magnitude and acts as sintering aid. Highest conductivity of 2.62 × 10−4 Scm−1 at 25 °C has been observed for 2 wt% CeO2 added Li6.6La3Zr1.6Sb0.4O12 ceramic sintered at 1050 °C for 6 h.
•Li6.6La3Zr1.6Sb0.4O12 was prepared by solid state sintering method with wt% addition of CeO2 to form a composite solid electrolyte.•High conducting cubic phase garnet structure of LLZO was confirmed from X-Ray diffraction analysis and distribution of Ce at grain and grain boundary was detected by elemental mapping.•With addition of CeO2, the sintering temperature and duration reduced and the conductivity enhanced.•Maximum ionic conductivity of 2.62 × 10−4 Scm−1 at 25 °C has been observed for 2 wt% CeO2 added Li6.6La3Zr1.6Sb0.4O12 ceramic.
The human Mre11/Rad50/Nbs1 (hMRN) complex is critical for the sensing, processing, and signaling of DNA double-strand breaks. The nuclease activity of Mre11 is essential for mammalian development and ...cell viability, although the regulation and substrate specificity of Mre11 have been difficult to define. Here we show that hMRN catalyzes sequential endonucleolytic and exonucleolytic activities on both 5′ and 3′ strands of DNA ends containing protein adducts, and that Nbs1, ATP, and adducts are essential for this function. In contrast, Nbs1 inhibits Mre11/Rad50-catalyzed 3′-to-5′ exonucleolytic degradation of clean DNA ends. The hMRN endonucleolytic cleavage events are further stimulated by the phosphorylated form of the human C-terminal binding protein-interacting protein (CtIP) DNA repair enzyme, establishing a role for CtIP in regulating hMRN activity. These results illuminate the important role of Nbs1 and CtIP in determining the substrates and consequences of human Mre11/Rad50 nuclease activities on protein-DNA lesions.
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•The MRN complex introduces endonucleolytic cuts in DNA adjacent to 5′ adducts•Nbs1 promotes MR exonuclease at adduct sites but blocks resection of open ends•MRN endo- and exonuclease activity targets both strands of DNA close to the adduct•MRN endonuclease activity at blocked ends is stimulated by CtIP
Deshpande et al. reconstitute processing of DNA ends containing protein adducts using human MRN complex in vitro. Nbs1 promotes Mre11/Rad50-catalyzed endo- and exonucleolytic cleavage of DNA containing 5′ adducts to generate clean double-strand break ends.
Approximately 50 000 women of reproductive age in the United States are currently living after kidney transplantation (KT), and another 2800 undergo KT each year. Although KT improves reproductive ...function in women with ESRD, studies of post‐KT pregnancies are limited to a few voluntary registry analyses and numerous single‐center reports. To obtain more generalizable inferences, we performed a systematic review and meta‐analysis of articles published between 2000 and 2010 that reported pregnancy‐related outcomes among KT recipients. Of 1343 unique studies, 50 met inclusion criteria, representing 4706 pregnancies in 3570 KT recipients. The overall post‐KT live birth rate of 73.5% (95%CI 72.1–74.9) was higher than the general US population (66.7%); similarly, the overall post‐KT miscarriage rate of 14.0% (95%CI 12.9–15.1) was lower (17.1%). However, complications of preeclampsia (27.0%, 95%CI 25.2–28.9), gestational diabetes (8.0%, 95%CI 6.7–9.4), Cesarean section (56.9%, 95%CI 54.9–58.9) and preterm delivery (45.6%, 95%CI 43.7–47.5) were higher than the general US population (3.8%, 3.9%, 31.9% and 12.5%, respectively). Pregnancy outcomes were more favorable in studies with lower mean maternal ages; obstetrical complications were higher in studies with shorter mean interval between KT and pregnancy. Although post‐KT pregnancy is feasible, complications are relatively high and should be considered in patient counseling and clinical decision making.
This systematic review and meta‐analysis of pregnancy‐related outcomes in kidney transplant recipients shows that while pregnancies are viable, obstetric complications are relatively high and should be considered in patient counseling and clinical decision making. See editorial by Armenti on page 2275.
The series Li
7−4
x
Ge
x
La
3
Zr
2
O
12
has been synthesized using conventional solid-state reaction method by substituting Germanium (Ge) at the Li site with the varying content of Ge (
x
) from ...0.05 to 0.20. The conducting cubic phase is confirmed using XRD analysis. The surface morphology and elemental distribution have been studied with the help of SEM characterization. The densities of the samples were calculated. For the confirmation of functional groups present, IR spectroscopy has been studied. The modulus and ac conductivity studies have also been examined. A complex impedance study has been carried out in the frequency range 20 Hz to 20 MHz .The highest ionic conductivity has been observed for 0.10 Ge. The minimum activation energy of 0.56 eV is associated with the highest conductivity value of 7.23 × 10
−6
S/cm at room temperature. The increment in ionic conductivity by one order at room temperature makes 0.10 Ge containing ceramic sample a promising candidate as a solid electrolyte.
Fruit cultivation plays a pivotal role in improvement of the agricultural economy. Pomegranate is a nutritionally rich fruit that is highly valuable because of its excellent antioxidant properties, ...richness in vitamins and fiber. Pomegranate is affected by diseases, which can severely affect its yield and quality. Timely disease detection is vital for effective disease control in pomegranate orchards. This study presents a novel approach for disease detection in pomegranate and categorization of pomegranate using a hybrid Convolutional Neural Network (CNN) coupled with the Honey Badger Optimization Algorithm (HBOA). The proposed hybrid CNN-HBOA approach leverages the strengths of both CNN and metaheuristic optimization algorithm HBOA. The CNN model was designed to extract high-level features from images of pomegranate affected by various diseases, and HBOA was employed to fine-tune the CNN parameters to improve the accuracy and robustness of the model. Initially, the quality of the images was enhanced using a contrast enhancement technique, and the images were segmented using the Detectron2 algorithm. Finally, the extracted features were fed as input to the disease detection stage wherein the CNN classifies the disease. Furthermore, the classification accuracy of the CNN model was enhanced using the HBOA algorithm. The performance of the hybrid CNN-HBOA algorithm was evaluated using a vast collection of images depicting multiple disease categories of pomegranate. Experimental results demonstrate the superiority of the hybrid CNN-HBOA system, which achieves a detection accuracy of 99.58%, precision of 100%, recall of 99.71% and F1 score of 99.75% compared to other existing state-of-the-art models.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The Mre11/Rad50/Nbs1 complex initiates double-strand break repair by homologous recombination (HR). Loss of Mre11 or its nuclease activity in mouse cells is known to cause genome aberrations and ...cellular senescence, although the molecular basis for this phenotype is not clear. To identify the origin of these defects, we characterized Mre11-deficient (MRE11−/−) and nuclease-deficient Mre11 (MRE11−/H129N) chicken DT40 and human lymphoblast cell lines. These cells exhibit increased spontaneous chromosomal DSBs and extreme sensitivity to topoisomerase 2 poisons. The defects in Mre11 compromise the repair of etoposide-induced Top2-DNA covalent complexes, and MRE11−/− and MRE11−/H129N cells accumulate high levels of Top2 covalent conjugates even in the absence of exogenous damage. We demonstrate that both the genome instability and mortality of MRE11−/− and MRE11−/H129N cells are significantly reversed by overexpression of Tdp2, an enzyme that eliminates covalent Top2 conjugates; thus, the essential role of Mre11 nuclease activity is likely to remove these lesions.
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•Topoisomerase 2 (Top2) frequently fails to complete catalysis•Failed catalysis causes the formation of Top2-cleavage complex (Top2cc)•Mre11 nuclease eliminates Top2cc followed by DNA double-strand break repair•Top2cc accumulation leads mitotic chromosomal breakage and apoptosis
The MRN complex is critical for genomic stability through several mechanisms. Hoa et al. find that nuclease activity of Mre11 is critical for the removal of topoisomerase 2-cleavage complexes that naturally accumulate in the genome when topoisomerase 2 fails to complete catalysis.
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