Continuous-wave room-temperature diamond maser

The maser, older sibling of the laser, has been confined to relative obscurity due to its reliance on cryogenic refrigeration and high-vacuum systems. Despite this it has found application in deep-space communications and radio astronomy due to its unparalleled performance as a low-noise amplifier and oscillator. The recent demonstration of a room-temperature solid- state maser exploiting photo-excited triplet states in organic pentacene molecules paves the way for a new class of maser that could find applications in medicine, security and sensing, taking advantage of its sensitivity and low noise. However, to date, only pulsed operation has been observed in this system. Furthermore, organic maser molecules have poor thermal and mechanical properties, and their triplet sub-level decay rates make continuous emission challenging: alternative materials are therefore required. Therefore, inorganic materials containing spin-defects such as diamond and silicon carbide have been proposed. Here we report a continuous-wave (CW) room-temperature maser oscillator using optically pumped charged nitrogen-vacancy (NV) defect centres in diamond. This demonstration unlocks the potential of room-temperature solid-state masers for use in a new generation of microwave devices.Comment: 7 pages, 4 figure

Effects of CuO additives and sol-gel technique on NiNb2O6 dielectric ceramics for LTCC application

The effects of CuO additives and sol–gel method synthesis on the sintering behavior, microstructure and the microwave dielectric properties of NiNb2O6 ceramics were investigated systematically. The NiNb2O6 ceramics were synthesized with traditional solid state method and sol–gel method, and the CuO additives were used in the solid state method for comparison. The sintering temperature of NiNb2O6 ceramics with the highest densification can be effectively reduced from about 1275 °C to 1050 and 1100 °C respectively by using CuO additions and sol–gel technique. To study their applicability in low temperature co-fired ceramic technology, dielectric properties have been characterized. The dielectric properties exhibited a significant dependence on the sintering condition, composition and crystal structure of the ceramics. In particular, the 2.5 wt% CuO-doped NiNb2O6 ceramics sintered at 1050 °C have excellent microwave dielectric properties: εr = 21.45, Q × f = 23,531 GHz, τf = −27.9 ppm/°C. While the NiNb2O6 ceramics prepared by sol–gel method obtain microwave dielectric properties as: εr = 19.16, Q × f = 11,149 GHz, τf = −27.3 ppm/°C after sintered at 1100 °C for 2 h

Brain multiplexes reveal morphological connectional biomarkers fingerprinting late brain dementia states

Accurate diagnosis of mild cognitive impairment (MCI) before conversion to Alzheimer\u27s disease (AD) is invaluable for patient treatment. Many works showed that MCI and AD affect functional and structural connections between brain regions as well as the shape of cortical regions. However, \u27shape connections\u27 between brain regions are rarely investigated -e.g., how morphological attributes such as cortical thickness and sulcal depth of a specific brain region change in relation to morphological attributes in other regions. To fill this gap, we unprecedentedly design morphological brain multiplexes for late MCI/AD classification. Specifically, we use structural T1-w MRI to define morphological brain networks, each quantifying similarity in morphology between different cortical regions for a specific cortical attribute. Then, we define a brain multiplex where each intra-layer represents the morphological connectivity network of a specific cortical attribute, and each inter-layer encodes the similarity between two consecutive intra-layers. A significant performance gain is achieved when using the multiplex architecture in comparison to other conventional network analysis architectures. We also leverage this architecture to discover morphological connectional biomarkers fingerprinting the difference between late MCI and AD stages, which included the right entorhinal cortex and right caudal middle frontal gyrus

One-step hydrothermal synthesis of graphene decorated V2O5 nanobelts for enhanced electrochemical energy storage

Graphene-decorated V2O5 nanobelts (GVNBs) were synthesized via a low-temperature hydrothermal method in a single step. V2O5 nanobelts (VNBs) were formed in the presence of graphene oxide, a mild oxidant, which also enhanced the conductivity of GVNBs. From the electron energy loss spectroscopy analysis, the reduced graphene oxide (rGO) are inserted into the layered crystal structure of V2O5 nanobelts, which further confirmed the enhanced conductivity of the nanobelts. The electrochemical energy-storage capacity of GVNBs was investigated for supercapacitor applications. The specific capacitance of GVNBs was evaluated using cyclic voltammetry (CV) and charge/discharge (CD) studies. The GVNBs having V2O5-rich composite, namely, V(3)G(1) (VO/GO = 3:1), showed superior specific capacitance in comparison to the other composites (V(1)G(1) and V(1)G(3)) and the pure materials. Moreover, the V(3)G(1) composite showed excellent cyclic stability and the capacitance retention of about 82% was observed even after 5000 cycles.open

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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Adaptive Introgression across Semipermeable Species Boundaries between Local Helicoverpa zea and Invasive Helicoverpa armigera Moths.

Hybridization between invasive and native species has raised global concern, given the dramatic increase in species range shifts and pest outbreaks due to anthropogenic dispersal. Nevertheless, secondary contact between sister lineages of local and invasive species provides a natural laboratory to understand the factors that determine introgression and the maintenance or loss of species barriers. Here, we characterize the early evolutionary outcomes following secondary contact between invasive Helicoverpa armigera and native H. zea in Brazil. We carried out whole-genome resequencing of Helicoverpa moths from Brazil in two temporal samples: during the outbreak of H. armigera in 2013 and 2017. There is evidence for a burst of hybridization and widespread introgression from local H. zea into invasive H. armigera coinciding with H. armigera expansion in 2013. However, in H. armigera, the admixture proportion and the length of introgressed blocks were significantly reduced between 2013 and 2017, suggesting selection against admixture. In contrast to the genome-wide pattern, there was striking evidence for adaptive introgression of a single region from the invasive H. armigera into local H. zea, including an insecticide resistance allele that increased in frequency over time. In summary, despite extensive gene flow after secondary contact, the species boundaries are largely maintained except for the single introgressed region containing the insecticide-resistant locus. We document the worst-case scenario for an invasive species, in which there are now two pest species instead of one, and the native species has acquired resistance to pyrethroid insecticides through introgression

Analysis of PM10 in Kuala Terengganu by Instrumental Neutron Activation Analysis

Instrumental neutron activation analysis was used for the determination of trace elements in airborne particulate matter (PM10) for air pollution monitoring. For the collection of air samples, the PM10 high volume sampler unit and Whatman 41 cellulose filter papers were employed. Samples were collected at 13 selected sampling sites covering areas in the city center, inner and outer city of Kuala Terengganu during the month of March 2005. The average PM10 was 69.64 μgm-3, 83.58 μgm-3 and 72.22 μgm-3 for sampling stations located in the city center, inner and outer city of Kuala Terengganu, respectively. It was found that the mass of air particles in the study area was higher compared to Bangi and Kuala Lumpur. Chemical analysis of selected elements (Al, Fe, Cu, Pb, V, Mn, Zn, Cr, As Cd), ionic species (Na+, SO4 2-, Cl-, NH4 +,Mg2+, K+ , Ca2+) and some rare earth elements (REE) were included in this study. In general, most of the average concentration of trace elements in the city center sampling stations was generally higher than the inner and outer city sampling stations. The concentrations of trace elements in sampling stations follow the general trend of Al>Fe>Zn>Cu>Mn>Pb>V>Cr>As>Ni>Cd. The elements concentration ranged from 680-2119 ngm-3, 170-1132 ngm-3, 8.13-122.4 ngm-3, 8.48-77.3 ngm-3, 7.68-14.4 ngm-3, 1-90.4 ngm-3, 1.47-3.25 ngm-3, 1.43-5.03 ngm-3, 1.15-4.45 ngm-3, 0.24-3.75 ngm-3 and 0.28-1.36 ngm-3, respectively

A new portable vibrator for plaster pouring: effect on the marginal fit at cylinder-abutment

OBJECTIVE: The aim of this study was to test a new portable vibrator for plaster pouring (developed for this purpose), comparing the effect of its use on the accuracy of working cast of implant-supported restorations to the conventional vibrator. MATERIAL AND METHODS: From a master cast with 2 implants, 30 transfer moldings were made randomly and divided into three groups: Group I (GI): pouring performed in an outsourced dental laboratory with conventional plaster vibrator (10 casts), Group II (GII): pouring performed in the laboratory of the Federal University of Santa Catarina (UFSC) with conventional plaster vibrator (10 casts) and Group III (GIII): pouring performed with the portable vibrator fabricated for this study (10 casts). The position of the analogue and marginal adaptation of the infrastructure were verified by testing the single screw on the master model and on the working model. The measurement of misfit was blindly performed with a precision microscope and analyzing unit, Quadra-Check 200. The data were statistically analyzed by analysis of variance (ANOVA) and the Holm-Sidak test (α=0.05). RESULTS: Means±standard deviations were as follows: GI: 19.19±4.73 µm; GII: 21.72±5.41 µm; GIII: 13.5±2.39 µm (P<0.05), with GIII significantly lower as compared to the other groups. CONCLUSION: Within the limitations of this study, it was concluded that a greater accuracy of working cast was achieved when a portable vibrator was used for casting molds

Early Initiation of Colorectal Cancer Screening in Individuals with Affected First-degree Relatives

BACKGROUND: Several guidelines recommend initiating colorectal cancer screening at age 40 for individuals with affected first-degree relatives, yet little evidence exists describing how often these individuals receive screening procedures. OBJECTIVES: To determine the proportion of individuals in whom early initiation of colorectal cancer screening might be indicated and whether screening disparities exist. DESIGN: Population-based Supplemental Cancer Control Module to the 2000 National Health Interview Survey. PARTICIPANTS: Respondents, 5,564, aged 40 to 49 years were included within the analysis. MEASUREMENTS: Patient self-report of sigmoidoscopy, colonoscopy, or fecal occult blood test. RESULTS: Overall, 279 respondents (5.4%: 95% C.I., 4.7, 6.2) reported having a first-degree relative affected with colorectal cancer. For individuals with a positive family history, 67 whites (27.9%: 95% C.I., 21.1, 34.5) and 3 African American (9.3%: 95% C.I., 1.7, 37.9) had undergone an endoscopic procedure within the previous 10 years (P-value = .03). After adjusting for age, family history, gender, educational level, insurance status, and usual source of care, whites were more likely to be current with early initiation endoscopic screening recommendations than African Americans (OR = 1.38: 95% C.I., 1.01, 1.87). Having an affected first-degree relative with colorectal cancer appeared to have a stronger impact on endoscopic screening for whites (OR = 3.21: 95% C.I., 2.31, 4.46) than for African Americans (OR = 1.05: 95% C.I., 0.15, 7.21). CONCLUSIONS: White participants with a family history are more likely to have endoscopic procedures beginning before age 50 than African Americans

Evaluation of the accuracy of different transfer impression techniques for multiple implants

The aim of this study was to evaluate the accuracy of three implant transfer impression techniques. Four groups (n = 5) were defined, according to the technique: TC - tapered copings without splint; SC - square copings without splint; SCS - square copings splinted with dental floss and acrylic resin, and CG (control group) - master model with four external hexagonal implants and a superstructure. Individual trays and polyether were used for the impression. All casts were checked for their fit into the master superstructure; for this, all four screws were placed in the implants. Digital photos were taken and images were analyzed using UTHSCSA ImageTool software. Statistical analyses were performed using one-way analysis of variance and Student’s t test (p < 0.05). The means and standard deviation were (µm): CG = 2.03 ± 0.00, TC = 14.74 ± 3.41, SC = 12.08 ± 2.56, and SCS = 6.51 ± 0.09. The control group was found to be statistically different from the TC and SC groups. Within the limitations of this study, all groups presented clinically acceptable standard gap values, and the SCS group showed no statistical difference in relation to the CG (control group), demonstrating more accuracy and fidelity to transfer implants