Characterization of Low-Loss Dielectric Materials for High-Speed and High-Frequency Applications.

In this study, the Df (dissipation factor or loss tangent) and Dk (dielectric constant or permittivity) of the low-loss dielectric material from three different vendors are measured by the Fabry-Perot open resonator (FPOR) technique. Emphasis is placed on the sample preparation, data collection, and the comparison with the data sheet values provided from vendors. A coplanar waveguide with ground (CPWG) test vehicle with one of these raw dielectric materials (vendor 1) is designed (through Polar and simulation) and fabricated. The impedance of the test vehicle is measured by TDR (time-domain reflectometer), and the effective Dk of the test vehicle is calculated by the real cross-section of the metal line width, spacing, and thickness of the test vehicle and a closed-form equation. In parallel, the insertion loss and return loss are measured with the VNA (vector network analyzer) of the test vehicle. Finally, the measurement and simulation results are correlated. Some recommendations on the low-loss dielectric materials of the Dk and Df are also provided.

Comparative performance of two commercial sample-to-result systems for hepatitis C virus quantitation and genotyping.

OBJECTIVES: Accurate assays for hepatitis C virus (HCV) quantitation and genotyping are important for the management of HCV infection. In this study, we evaluated the performance of cobas HCV and cobas HCV GT assays (Roche) for HCV quantitation and genotyping on the cobas 4800 System. METHODS: We compared the performance of the cobas HCV assays with another commercial system (Abbott m2000) using a panel of well-characterized patient samples and proficiency testing samples. RESULTS: The limit-of-detection of the cobas HCV assay in our center was higher (15 IU/mL) than the manufacturer claim (9.2 IU/mL). The assay showed high analytical specificity, accuracy, precision, and linearity. Performance was congruent with the RealTime HCV assay (Abbott). For genotyping, the cobas HCV GT assay only showed moderate agreement with the RealTime HCV Genotype II assay (kappa = 0.550). The cobas assay outperformed the RealTime assay for typing HCV genotypes 1b and 6 (p = 0.033). CONCLUSION: Our results confirm that the cobas 4800 System is a reliable platform for HCV quantitation and genotyping. The cobas HCV GT assay is a good choice for genotype 1b/6 endemic areas in east Asia, clearly outperforming the RealTime HCV Genotype II assay.

Housing First and Photovoice: Transforming Lives, Communities, and Systems.

This article presents findings from a community-based participatory evaluation of a Housing First program on the Island of O'ahu. In this study, clients in a Housing First program used Photovoice to evaluate the program and to advocate for progressive housing policies. Written together by members of the Housing First Photovoice group, this collaborative article describes the outcomes from both the Housing First program and the Photovoice project and demonstrates the ways in which participatory program evaluations can interact with client-driven programs like Housing First to produce a cumulative, transformative impact. Findings suggest that community psychologists hoping to re-engage with community mental health systems through enacting transformative change should consider taking a community-based participatory approach to program evaluation because increased client voice in community mental health programs and their evaluations can have far-reaching, transformative impacts for research, practice, and policy.

Bayesian Analysis of Individual Level Personality Dynamics.

A Bayesian technique with analyses of within-person processes at the level of the individual is presented. The approach is used to examine whether the patterns of within-person responses on a 12-trial simulation task are consistent with the predictions of ITA theory (Dweck, 1999). ITA theory states that the performance of an individual with an entity theory of ability is more likely to spiral down following a failure experience than the performance of an individual with an incremental theory of ability. This is because entity theorists interpret failure experiences as evidence of a lack of ability which they believe is largely innate and therefore relatively fixed; whilst incremental theorists believe in the malleability of abilities and interpret failure experiences as evidence of more controllable factors such as poor strategy or lack of effort. The results of our analyses support ITA theory at both the within- and between-person levels of analyses and demonstrate the benefits of Bayesian techniques for the analysis of within-person processes. These include more formal specification of the theory and the ability to draw inferences about each individual, which allows for more nuanced interpretations of individuals within a personality category, such as differences in the individual probabilities of spiraling. While Bayesian techniques have many potential advantages for the analyses of processes at the level of the individual, ease of use is not one of them for psychologists trained in traditional frequentist statistical techniques.

Contribution of HIV-1 genomes that do not integrate to the basic reproductive ratio of the virus.

Recent experimental data indicate that HIV-1 DNA that fails to integrate (from now on called uDNA) can by itself successfully produce infectious offspring virions in resting T cells that become activated after infection. This scenario is likely important at the initial stages of the infection. We use mathematical models to calculate the relative contribution of unintegrated and integrated viral DNA to the basic reproductive ratio of the virus, R0, and the models are parameterized with preliminary data. This is done in the context of both free virus spread and transmission of the virus through virological synapses. For free virus transmission, we find that under preliminary parameter estimates, uDNA might contribute about 20% to the total R0. This requires that a single copy of uDNA can successfully replicate. If the presence of more than one uDNA copy is required for replication, uDNA does not contribute to R0. For synaptic transmission, uDNA can contribute to R0 regardless of the number of uDNA copies required for replication. The larger the number of viruses that are successfully transmitted per synapse, however, the lower the contribution of uDNA to R0 because this increases the chances that at least one virus integrates. Using available parameter values, uDNA can maximally contribute 20% to R0 in this case. We argue that the contribution of uDNA to virus reproduction might also be important for continued low level replication of HIV-1 in the presence of integrase inhibitor therapy. Assuming a 20% contribution of uDNA to the overall R0, our calculations suggest that R0=1.6 in the absence of virus integration. While these are rough estimates based on preliminary data that are currently available, this analysis provides a framework for future experimental work which should directly measure key parameters.

A single-blind, placebo-controlled, dose-ranging trial of oral hepatic-directed vesicle insulin add-on to oral antidiabetic treatment in patients with type 2 diabetes mellitus.

The dose response of postprandial plasma glucose (PPG) to add-on, premeal oral hepatic-directed vesicle-insulin (HDV-I), an investigational lipid bio-nanoparticle hepatocyte-targeted insulin delivery system, was evaluated in a 3-test-meal/day model in type 2 diabetes patients. The single-blind, placebo-controlled, dose-escalating trial enrolled 6 patients with HbA(1c) 8.6 ± 2.0% (70.0 ± 21.9 mmol/mol) and on stable metformin therapy. Patients received oral HDV-I capsules daily 30 minutes before breakfast, lunch, and dinner as follows: placebo capsules, 0.05, 0.1, 0.2, and 0.4 U/kg on days 1, 2, 3, 4, and 5, respectively. Outcome measures were PPG and incremental PPG area under the concentration-time curve (AUC). All 4 doses of oral HDV-I statistically significantly lowered mean PPG (P ≤ .0110 each) and incremental PPG (P ≤ .0352 each) AUC compared to placebo. A linear dose response was not observed. The 0.05 U/kg dose was the minimum effective dose in the dosage range studied. Three adverse events unrelated to treatment were observed. Add-on oral HDV-I 0.05-0.4 U/kg significantly lowered PPG excursions and the dose response curve was flat. These results are consistent with the lack of a linear dose response between portal and systemic plasma insulin concentrations in previous animal and human studies. Oral HDV-I was safe and well tolerated.

Superior mesenteric artery blood flow velocities following medical treatment of a patent ductus arteriosus.

We examined superior mesenteric artery blood flow velocity in response to feeding in infants randomized to trophic feeds (n = 16) or nil per os (n = 18) during previous treatment for patent ductus arteriosus. Blood flow velocity increased earlier in the fed infants, but was similar in the 2 groups at 30 minutes after feeding.

Nearest-neighbor interactions, habitat fragmentation, and the persistence of host-pathogen systems.

Spatial interactions are known to promote stability and persistence in enemy-victim interactions if instability and extinction occur in well-mixed settings. We investigate the effect of spatial interactions in the opposite case, where populations can persist in well-mixed systems. A stochastic agent-based model of host-pathogen dynamics is considered that describes nearest-neighbor interactions in an undivided habitat. Contrary to previous notions, we find that in this setting, spatial interactions in fact promote extinction. The reason is that, in contrast to the mass-action system, the outcome of the nearest-neighbor model is governed by dynamics in small "local neighborhoods." This is an abstraction that describes interactions in a minimal grid consisting of an individual plus its nearest neighbors. The small size of this characteristic scale accounts for the higher extinction probabilities. Hence, nearest-neighbor interactions in a continuous habitat lead to outcomes reminiscent of a fragmented habitat, which is underlined further with a metapopulation model that explicitly assumes habitat fragmentation. Beyond host-pathogen dynamics, axiomatic modeling shows that our results hold for generic enemy-victim interactions under specified assumptions. These results are used to interpret a set of published experiments that provide a first step toward model testing and are discussed in the context of the literature.

Complex spatial dynamics of oncolytic viruses in vitro: mathematical and experimental approaches.

Oncolytic viruses replicate selectively in tumor cells and can serve as targeted treatment agents. While promising results have been observed in clinical trials, consistent success of therapy remains elusive. The dynamics of virus spread through tumor cell populations has been studied both experimentally and computationally. However, a basic understanding of the principles underlying virus spread in spatially structured target cell populations has yet to be obtained. This paper studies such dynamics, using a newly constructed recombinant adenovirus type-5 (Ad5) that expresses enhanced jellyfish green fluorescent protein (EGFP), AdEGFPuci, and grows on human 293 embryonic kidney epithelial cells, allowing us to track cell numbers and spatial patterns over time. The cells are arranged in a two-dimensional setting and allow virus spread to occur only to target cells within the local neighborhood. Despite the simplicity of the setup, complex dynamics are observed. Experiments gave rise to three spatial patterns that we call "hollow ring structure", "filled ring structure", and "disperse pattern". An agent-based, stochastic computational model is used to simulate and interpret the experiments. The model can reproduce the experimentally observed patterns, and identifies key parameters that determine which pattern of virus growth arises. The model is further used to study the long-term outcome of the dynamics for the different growth patterns, and to investigate conditions under which the virus population eliminates the target cells. We find that both the filled ring structure and disperse pattern of initial expansion are indicative of treatment failure, where target cells persist in the long run. The hollow ring structure is associated with either target cell extinction or low-level persistence, both of which can be viewed as treatment success. Interestingly, it is found that equilibrium properties of ordinary differential equations describing the dynamics in local neighborhoods in the agent-based model can predict the outcome of the spatial virus-cell dynamics, which has important practical implications. This analysis provides a first step towards understanding spatial oncolytic virus dynamics, upon which more detailed investigations and further complexity can be built.

Discovery of seven novel Mammalian and avian coronaviruses in the genus deltacoronavirus supports bat coronaviruses as the gene source of alphacoronavirus and betacoronavirus and avian coronaviruses as the gene source of gammacoronavirus and deltacoronavirus.

Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus, Deltacoronavirus, in the subfamily Coronavirinae. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sparrow coronavirus HKU17, magpie robin coronavirus HKU18, night heron coronavirus HKU19, wigeon coronavirus HKU20, and common moorhen coronavirus HKU21. Complete genome sequencing and comparative genome analysis showed that the avian and mammalian deltacoronaviruses have similar genome characteristics and structures. They all have relatively small genomes (25.421 to 26.674 kb), the smallest among all coronaviruses. They all have a single papain-like protease domain in the nsp3 gene; an accessory gene, NS6 open reading frame (ORF), located between the M and N genes; and a variable number of accessory genes (up to four) downstream of the N gene. Moreover, they all have the same putative transcription regulatory sequence of ACACCA. Molecular clock analysis showed that the most recent common ancestor of all coronaviruses was estimated at approximately 8100 BC, and those of Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus were at approximately 2400 BC, 3300 BC, 2800 BC, and 3000 BC, respectively. From our studies, it appears that bats and birds, the warm blooded flying vertebrates, are ideal hosts for the coronavirus gene source, bats for Alphacoronavirus and Betacoronavirus and birds for Gammacoronavirus and Deltacoronavirus, to fuel coronavirus evolution and dissemination.

Hepatic-directed vesicle insulin: a review of formulation development and preclinical evaluation.

Hepatic-directed vesicle insulin (HDV-I), a novel investigational vesicle (<150 nm diameter) insulin delivery system that carries insulin and a specific hepatocyte-targeting molecule (HTM) in its phospholipid bilayer and has the ability to mimic a portal vein insulin infusion remotely [subcutaneous (SC) HDV-I] and noninvasively (oral HDV-I), has been developed. This review summarizes formulation development, subsequent refinements, and results of preclinical evaluation studies, including biodistribution, mechanistic, and toxicology studies of predominantly SC HDV-I, in various animal models. Studies conducted to date have confirmed the hepatocyte specificity of HDV and HDV-I and revealed that HDV-I can stimulate the conversion of hepatic glucose output to uptake at a dose that is <1% of the dose of regular insulin (RI) required for liver stimulation; suggest that the enhanced antihyperglycemic effect of HDV-I is due to hepatic glucose uptake; and in pancreatectomized dogs during an oral glucose tolerance test, HDV-I normalized blood glucose curves when compared to control curves in intact dogs and prevented secondary hypoglycemia in contrast to the same dose of RI. A 28-day SC HDV toxicity study in rats revealed no clinical, clinical laboratory, or histopathological findings, and the battery of three genetic toxicology studies was negative. Results support the hypothesis that HDV-I works by stimulating hepatic glucose uptake and/or glycogen storage in insulin-deficient animals. The ability to target the delivery of HDV-I to the liver reestablishes the liver as a major metabolic modulator of glucose metabolism. The future of HDV-I depends on the results of ongoing development and longer term clinical trials.

[Determination of lead, cadmium, mercury, chromium and arsenic in acrylonitrile-butadiene-styrene copolymer using microwave digestion-ICP-MS].

A method was studied for the analysis of Cr, As, Cd, Hg and Pb in acrylonitrile-butadiene-styrene copolymer by using ICP-MS. The instrument parameters were optimized and the introduction system was developed systematically. The sample is decomposed by microwave digestion. The digestion condition was optimized concerning digestion system, proportion of acids and digestion procedure, which affords reference for the preparation of the same kinds of polymer samples. The detection limits of the method for all sample elements were 0.7-6.5 ng x g(-1), the recoveries were 89.8%-110.8%, and the RSDs were 2.8%-11.3%. The analytical method presented was characterized with good precision and accuracy, simplicity, rapidness, low limits of detection and no matrix matching requirements.