277 research outputs found
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MicroRNA detection on microsensor arrays by SPR imaging measurements with enzymatic signal enhancement.
We investigated sequence-specific and simultaneous microRNA (miRNA) detections by surface plasmon resonance (SPR) imaging measurements on SPR chips possessing an Au spot array modified with probe DNAs based on a miRNA-detection-selective SPR signal amplification method. MiRNAs were detected with the detection limit of the attomole level by SPR imaging measurements for different miRNA concentrations on a single chip. SPR signals were enhanced based on a combination process of sequence-specific hybridization of the miRNA to the probe DNAs, extension reaction of polyadenine (poly(A)) tails by poly(A) polymerase, binding of a ternary complex of T30-biotin/horseradish peroxidase (HRP)-biotin/streptavidin to the poly(A) tails, and the oxidation reaction of tetramethylbenzidine (TMB) on the HRP by providing a blue precipitate on the surface. This process sequence-specifically and dramatically amplified the SPR signals. This is a simple, cost-effective, and feasible signal amplification method based on the organic compound TMB instead of metal nanoparticles
Implementation of Raman spectroscopy at manufacturing scale: Overcoming modeling challenges while implementing advanced process control
In order to improve glycation control in our new high intensity platform process, we investigated implementation of Raman spectroscopy to monitor and control glucose at low levels throughout the process. Using Raman allows a way to measure glucose near real time which in turn allows for a more responsive and flexible control algorithm. Prior literature has shown connections between elevated glucose levels and glycation when in presence of high protein concentrations, which was indicative of our process. Using Raman along with advanced process control (APC), allowed us the flexibility to reduce glycation back towards historical process levels.
We will share a case study of how Raman models were built using the RXN2-785 system and later deemed unresponsive due to high levels of fluorescence on day 5 of a 14 day process. We will discuss potential sources of the fluorescence and provide a multi-product comparison for perspective. Additional development effort was required in tight time frame to derive a manufacturing ready solution to this challenging problem. We will describe what that solution was and how we were able to successfully create new models with errors acceptable within our process control strategy design. Lastly, we will demonstrate how controlling glucose at lower levels during the process impacted glycation. Our work ended with two engineering runs at 17,000L scale where we used Raman spectroscopy to successfully monitor and control glucose at a lower set point and effectively lower glycation by 40% of its original value
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Placing High-Redshift Quasars in Perspective: Unifying Distant Quasars with Their Lower Redshift Counterparts through Near-Infrared Spectroscopy
I present spectroscopic measurements for 260 sources from the Gemini Near Infrared Spectrograph–Distant Quasar Survey (GNIRS-DQS). Being the largest uniform, homogeneous survey of its kind, it represents a flux-limited sample of Sloan Digital Sky Survey (SDSS) quasars at 1.5 < z < 3.5. A combination of the GNIRS and SDSS spectra covers principal quasar diagnostic features, chiefly the C IV λ1549, Mg II λλ2798, 2803, Hβ λ4861, and [O III] λλ4959, 5007 emission lines, in each source. The spectral inventory is utilized primarily to develop prescriptions for obtaining more accurate and precise redshifts, black hole masses, and accretion rates for all quasars. Additionally, the measurements facilitate an understanding of the dependence of rest-frame ultraviolet–optical spectral properties of quasars on redshift, luminosity, and Eddington ratio, and test whether the physical properties of the quasar central engine evolve over cosmic time
Vertical probe-induced asymmetric dust oscillation in complex plasma
Spherical, micrometer-sized particles within a Coulomb crystal levitated in
the sheath above the powered lower electrode in a GEC reference cell are
perturbed using a Zyvex S100 Nanomanipulator. Using the S100, a vertical probe
is positioned within the cell at various locations with respect to the crystal
formed within the sheath. As the probe is lowered toward the horizontal plane
of the dust layer, a circular cavity opens in the center of the crystal and
expands. To explore the minimally perturbative state, the probe is lifted to
the position that closes this cavity, the probe potential is oscillated, and
the motion of the particle directly beneath the probe is analyzed. Using a
simple electric field model for the plasma sheath, the change predicted in the
levitation height is compared with experiment.Comment: 9 pages, 2 tables, 13 figures, submitted to Physical Review E on
January 15, 2013 and assigned manuscript number EA1098
Initial cardiac diagnostic imaging choices for obese patients: cost and outcomes with cardiac MRI
Oxygen transfer rate model for cell-free and predictive D.O. control in intensified bioreactor processes
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Introduction: Science and Religion Around the World
From a scholarly perspective, we reasoned that our research examining the beliefs of scientists would provide insight into the major theoretical issues related to religious change and the impact of science on religion-and religion on science-in different national contexts. Our goal was to understand how science is related to ideas about secularization, or the decline of religion\u27s vitality and influence, among scientists and societies. For policy makers and the general public, our research would reveal how national ideologies and policies related to religion affect scientists\u27 work, and how this in tum might affect the way science is presented and implemented in their nations. We also wanted our research to increase understanding of how the personal religious views of scientists can shape their practice, dissemination, and interpretation of science, as well as how their scientific work can shape their religious views. Ultimately, where there is conflict between science and religion, we wanted our research to illuminate the root of this conflict. Does science destroy religious belief and authority? Does increased commitment to science really lead to decreased commitment to religion? How do views on religion affect how scientists approach research, teaching, and interactions with their colleagues, students, and the public? How many scientists see conflict between science and faith? Are there ways that scientists and religious communities can work together for the common good
Testing Electrostatic Complementarity in Enzyme Catalysis: Hydrogen Bonding in the Ketosteroid Isomerase Oxyanion Hole
A longstanding proposal in enzymology is that enzymes are electrostatically and geometrically complementary to the transition states of the reactions they catalyze and that this complementarity contributes to catalysis. Experimental evaluation of this contribution, however, has been difficult. We have systematically dissected the potential contribution to catalysis from electrostatic complementarity in ketosteroid isomerase. Phenolates, analogs of the transition state and reaction intermediate, bind and accept two hydrogen bonds in an active site oxyanion hole. The binding of substituted phenolates of constant molecular shape but increasing p K (a) models the charge accumulation in the oxyanion hole during the enzymatic reaction. As charge localization increases, the NMR chemical shifts of protons involved in oxyanion hole hydrogen bonds increase by 0.50–0.76 ppm/p K (a) unit, suggesting a bond shortening of ˜0.02 Å/p K (a) unit. Nevertheless, there is little change in binding affinity across a series of substituted phenolates (ΔΔG = −0.2 kcal/mol/p K (a) unit). The small effect of increased charge localization on affinity occurs despite the shortening of the hydrogen bonds and a large favorable change in binding enthalpy (ΔΔH = −2.0 kcal/mol/p K (a) unit). This shallow dependence of binding affinity suggests that electrostatic complementarity in the oxyanion hole makes at most a modest contribution to catalysis of ˜300-fold. We propose that geometrical complementarity between the oxyanion hole hydrogen-bond donors and the transition state oxyanion provides a significant catalytic contribution, and suggest that KSI, like other enzymes, achieves its catalytic prowess through a combination of modest contributions from several mechanisms rather than from a single dominant contribution
Radiographic Union Scoring Scale for Determining Consolidation Rates in the Calcaneus.
The reliable evaluation of osseous consolidation after hindfoot osteotomy can be difficult. Concomitant hindfoot osteotomies often dictate the advancement of weightbearing, and radiographs are the mainstay imaging tool owing to cost, efficiency, and radiation exposure. Understanding the radiographic parameters that can be used to reliably determine osseous healing is paramount. However, currently, no reliable or validated method is available to determine osseous healing of hindfoot osteotomies in irregular bones of the foot. The purpose of the present study was to develop a radiographic healing scoring system that would enhance the diagnostic healing assessment after elective calcaneal osteotomy. We adapted existing orthopedic scales validated for healing in the leg for application in the irregular bones of the foot. A total of 168 cases were evaluated by 6 blinded assessors to test the interrater reliability of subjective healing assessment compared with the proposed scoring system. The radiographs were classified by postoperative period: ≤4 weeks, 5 to 12 weeks, and \u3e12 weeks. The proposed scale had high interrater reliability but was burdensome. Using a priori item reduction protocols, a limited 6-item scale further improved internal consistency and reduced the burden. The result was excellent interrater reliability (α = 0.98, standard deviation 0.02, 95% confidence interval 0.91 to 0.96) among all assessors when using the scoring scale compared with unacceptable reliability (α = 0.438) for subjective osteotomy healing. The reliability of our system appeared superior to that of subjective assessment of osseous healing alone, even in the absence of clinical correlates after osteotomy of the calcaneus
Gemini Near Infrared Spectrograph Distant Quasar Survey: Initial Results
We present the first installment of spectroscopic measurements performed with the Gemini Near Infrared Spectrograph Distant Quasar Survey (GNIRS-DQS). This is a three-year project, launched in 2017, aimed at obtaining high quality near-infrared spectroscopy of 416 Sloan Digital Sky Survey (SDSS) quasars between redshifts of 1.5 and 3.5 in the ~1.0-2.5 μm band. A combination of the GNIRS and SDSS spectra will cover principal quasar diagnostic features, chiefly the C IV, Mg II, Hβ, and [O III] emission lines, in each source. The spectral inventory will be utilized primarily to develop prescriptions for obtaining more accurate and precise redshifts, black hole masses, and accretion rates for all quasars. Additionally, our measurements will facilitate a more complete understanding of how the rest-frame UV-optical spectral properties of quasars depend on redshift and luminosity, and test whether the physical properties of the quasar central engine evolve over cosmic time. Our raw data are immediately available to the public through the Gemini Observatory Archive, and our final reduced and calibrated spectra will be made available shortly thereafter on a dedicated public website. This work is supported by National Science Foundation grants AST-1815281 and AST-1815645.Fil: Matthews, Brandon. University of North Texas; Estados UnidosFil: Shemmer, Ohad. University of North Texas; Estados UnidosFil: Brotherton, Michael S.. University of North Texas; Estados UnidosFil: Andruchow, Ileana. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Boronson, Todd A.. Las Cumbres Observatory; ChileFil: Brandt, W. N.. State University of Pennsylvania; Estados UnidosFil: Cellone, Sergio Aldo. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Ferrero Sosa, Gabriel Antonio. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: and other authors. no específica; Argentina235th Meeting of the American Astronomical SocietySeattleEstados UnidosAmerican Astronomical Societ
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