Electrical and Low Frequency Noise Characterization of Graphene Chemical Sensor Devices Having Different Geometries.

Chemiresistive graphene sensors are promising for chemical sensing applications due to their simple device structure, high sensitivity, potential for miniaturization, low-cost, and fast response. In this work, we investigate the effect of (1) ZnO nanoparticle functionalization and (2) engineered defects onto graphene sensing channel on device resistance and low frequency electrical noise. The engineered defects of interest include 2D patterns of squares, stars, and circles and 1D patterns of slots parallel and transverse to the applied electric potential. The goal of this work is to determine which devices are best suited for chemical sensing applications. We find that, relative to pristine graphene devices, nanoparticle functionalization leads to reduced contact resistance but increased sheet resistance. In addition, functionalization lowers 1/f current noise on all but the uniform mesa device and the two devices with graphene strips parallel to carrier transport. The strongest correlations between noise and engineering defects, where normalized noise amplitude as a function of frequency f is described by a model of AN/fγ, are that γ increases with graphene area and contact area but decreases with device total perimeter, including internal features. We did not find evidence of a correlation between the scalar amplitude, AN, and the device channel geometries. In general, for a given device area, the least noise was observed on the least-etched device. These results will lead to an understanding of what features are needed to obtain the optimal device resistance and how to reduce the 1/f noise which will lead to improved sensor performance.

Correction: Impacts of a sugar sweetened beverage tax on body mass index and obesity in Thailand: A modelling study.

[This corrects the article DOI: 10.1371/journal.pone.0250841.].

Impacts of a sugar sweetened beverage tax on body mass index and obesity in Thailand: A modelling study.

BACKGROUND: The World Health Organization (WHO) recommends sugar-sweetened beverage (SSB) taxes to address obesity. Thailand has just launched the new tax rates for SSB in 2017; however, the existing tax rate is not as high as the 20% recommended by the WHO. The objective for this study was to estimate the impacts of an SSB tax on body mass index (BMI) and obesity prevalence in Thailand under three different scenarios based on existing SSB and recommended tax rates. METHODS: A base model was built to estimate the impacts of an SSB tax on SSB consumption, energy intake, BMI, and obesity prevalence. Literature review was conducted to estimate pass on rate, price elasticity, energy compensation, and energy balance to weight change. Different tax rates (11%, 20% and 25%) were used in the model. The model assumed no substitution effects, model values were based on international data since there was no empirical Thai data available. Differential effects by income groups were not estimated. FINDINGS: When applying 11%, 20%, and 25% tax rates together with 100% pass on rate and an -1.30 own-price elasticity, the SSB consumption decreased by 14%, 26%, and 32%, respectively. The 20% and 25% price increase in SSB price tended to reduce higher energy intake, weight status and BMI, when compared with an 11% increase in existing price increase of SSB. The percentage changes of obesity prevalence of 11%, 20% and 25% SSB tax rates were estimated to be 1.73%, 3.83%, and 4.91%, respectively. CONCLUSIONS: A higher SSB tax (20% and 25%) was estimated to reduce consumption and consequently decrease obesity prevalence. Since Thailand has already endorsed the excise tax structure, the new excise tax structure for SSB should be scaled up to a 20% or 25% tax rate if the SSB consumption change does not meet a favourable goal.

Cleveland Clinic International IV Robotics Summit.

PURPOSE: The proceedings of an international summit on the current and desired future state of use of robotic systems to compound intravenous (IV) solutions are summarized. SUMMARY: The International IV Robotics Summit was held at the Cleveland Clinic main campus in Cleveland, OH, on April 29 and 30, 2019. The purpose of the summit was 2-fold: (1) to define the current state of robotic IV compounding and (2) to develop a guide for automation companies, pharmacy departments, and drug manufacturers to improve the technology and expand the use of IV robotics in health systems in the future. The first day of the summit included 45-minute presentations by each of the speakers. Each lecturer recounted a different hospital's experience implementing and using IV robotics. On day 2 of the summit, an expert panel dedicated to mapping the future of IV robotics was convened to determine barriers to widespread adoption of IV robotics in health systems and offer potential solutions to remove these barriers. The expert panel targeted 3 specific audiences: robot manufacturers, drug manufacturers, and fellow pharmacy leaders. CONCLUSION: It is the hope of the international faculty that the information that emerged from the summit can be used by others to successfully implement IV compounding robotics in their sterile products areas to maximize patient safety. The summit also served as a call to action for pharmacy leaders, drug manufacturers, and robotic companies to develop a safer, more efficient future for patients by working together to optimize the development and operation of IV robotics.

Comparison of IV oncology infusions compounded via robotics and gravimetrics-assisted workflow processes.

PURPOSE: A study was conducted to compare an intravenous (IV) gravimetric technology-assisted workflow (TAWF) platform to an IV robotic system. In the study we reviewed both IV technology platforms using the same gravimetric quality assurance system, which allowed for direct comparison. METHODS: All oncology preparations compounded from January 2016 through December 2018 using either system were included in our retrospective analysis. Final preparation accuracy, IV system precision, and workflow throughput (analyzed using lean process methodologies) were evaluated. RESULTS: Data analysis indicated that use of the IV gravimetric TAWF system was associated with a significantly lower percentage of accuracy errors compared to the IV robotics system (1.58% vs 2.47%, P < 0.001), with no significant difference in absolute precision (1.12 vs 1.12 P = 0.952). Lean analysis demonstrated that overall completion time (17:49 minutes vs 24:45 minutes) and compound preparation time (2:39 minutes vs 6:07 minutes) were less with the IV gravimetric TAWF vs the IV robotics system. CONCLUSION: Implementation of either an IV gravimetric TAWF system or IV robotics system will result in similar compounding accuracy and precision. Preparation time was less with use of the IV gravimetric TAWF vs the IV robotic system, but the IV robotic system required less human intervention. Both systems ensure medication safety for patients, although the IV robotic system has increased safeguards in place. Therefore, the primary driver for implementing these systems is alternative factors such as cost of systems implementation and maintenance, employee safety, and drug waste.

Leveraging advanced preparation of oncology medications: Decreasing turnaround-times in an outpatient infusion center.

INTRODUCTION: Many oncology infusions are provided in hospital-based infusion centers. With hospital-based infusion centers seeing increased volumes, patient wait times continue to be a priority. Extended wait times for oncology infusions have been shown to lead to patient dissatisfaction. METHODS: Advanced Preparation of oncology infusion medications allows pharmacy to verify and prepare specific medications the day before a patient's infusion appointment. Our study targeted lower cost, commonly used medications to prepare in advance. Data analyzed included turnaround time (TAT), medication waste, and oncology infusion preparation volumes. Implementation took place in two phases to allow time for the healthcare team to adjust to the new workflow. Phase I medications include a small amount of medications prepared manually by pharmacy technicians. Phase II medications included all phase I medications plus additional medications that were compounded in the intravenous (IV) robotic compounding system. RESULTS: Our study demonstrated significant decrease in median TAT for medications prepared in advance. 537 infusions were prepared using the Advanced Preparation module with a median TAT of 24.2 minutes (IQR, 18.0-34.0). The pre-implementation median TAT was 45.0 minutes (IQR, 36.0-56.0), which represents a decrease of 20.8 minutes (46.2%) following implementation of the program, (p<0.001). There were a total of 149 advanced preparation doses that were wasted (21.7% of doses). CONCLUSION: We have seen a statistically significant reduction in TAT for Advanced Preparation medications. Low volume of Advanced Preparation medications compared to total infusion volume limited impact on overall TAT.

Surface potential and thin film quality of low work function metals on epitaxial graphene.

Metal films deposited on graphene are known to influence its electronic properties, but little is known about graphene's interactions with very low work function rare earth metals. Here we report on the work functions of a wide range of metals deposited on n-type epitaxial graphene (EG) as measured by Kelvin Probe Force Microscopy (KPFM). We compare the behaviors of rare earth metals (Pr, Eu, Er, Yb, and Y) with commonly used noble metals (Cr, Cu, Rh, Ni, Au, and Pt). The rare earth films oxidize rapidly, and exhibit unique behaviors when on graphene. We find that the measured work function of the low work function group is consistently higher than predicted, unlike the noble metals, which is likely due to rapid oxidation during measurement. Some of the low work function metals interact with graphene; for example, Eu exhibits bonding anomalies along the metal-graphene perimeter. We observe no correlation between metal work function and photovoltage, implying the metal-graphene interface properties are a more determinant factor. Yb emerges as the best choice for future applications requiring a low-work function electrical contact on graphene. Yb films have the strongest photovoltage response and maintains a relatively low surface roughness, ~5 nm, despite sensitivity to oxidation.

The Recombinant Sea Urchin Immune Effector Protein, rSpTransformer-E1, Binds to Phosphatidic Acid and Deforms Membranes.

The purple sea urchin, Strongylocentrotus purpuratus, possesses a sophisticated innate immune system that functions without adaptive capabilities and responds to pathogens effectively by expressing the highly diverse SpTransformer gene family (formerly the Sp185/333 gene family). The swift gene expression response and the sequence diversity of SpTransformer cDNAs suggest that the encoded proteins have immune functions. Individual sea urchins can express up to 260 distinct SpTransformer proteins, and their diversity suggests that different versions may have different functions. Although the deduced proteins are diverse, they share an overall structure of a hydrophobic leader, a glycine-rich N-terminal region, a histidine-rich region, and a C-terminal region. Circular dichroism analysis of a recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1) demonstrates that it is intrinsically disordered and transforms to α helical in the presence of buffer additives and binding targets. Although native SpTrf proteins are associated with the membranes of perinuclear vesicles in the phagocyte class of coelomocytes and are present on the surface of small phagocytes, they have no predicted transmembrane region or conserved site for glycophosphatidylinositol linkage. To determine whether native SpTrf proteins associate with phagocyte membranes through interactions with lipids, when rSpTrf-E1 is incubated with lipid-embedded nylon strips, it binds to phosphatidic acid (PA) through both the glycine-rich region and the histidine-rich region. Synthetic liposomes composed of PA and phosphatidylcholine show binding between rSpTrf-E1 and PA by fluorescence resonance energy transfer, which is associated with leakage of luminal contents suggesting changes in lipid organization and perhaps liposome lysis. Interactions with liposomes also change membrane curvature leading to liposome budding, fusion, and invagination, which is associated with PA clustering induced by rSpTrf-E1 binding. Longer incubations result in the extraction of PA from the liposomes, which form disorganized clusters. CD shows that when rSpTrf-E1 binds to PA, it changes its secondary structure from disordered to α helical. These results provide evidence for how SpTransformer proteins may associate with molecules that have exposed phosphates including PA on cell membranes and how the characteristic of protein multimerization may drive changes in the organization of membrane lipids.

Comparative Effectiveness and Safety Analysis of Dual Antiplatelet Therapies Within an Integrated Delivery System.

BACKGROUND: Dual antiplatelet therapy is a mainstay of care for percutaneous coronary intervention (PCI) patients; however, uncertainty exists in real-world practice about comparative effectiveness and safety outcomes. OBJECTIVE: To evaluate outcomes of different oral P2Y12 inhibitors in PCI patients. METHODS: We retrospectively studied patients treated between July 1, 2010, and December 31, 2013. Patients received clopidogrel, prasugrel, ticagrelor, or more than 1 antiplatelet (switch) during PCI. Outcomes were evaluated for major adverse cardiovascular events (MACE) and bleeding at 1 year. Propensity score matching with Cox proportional hazards analysis was used to determine predictors of MACE and bleeding. RESULTS: A total of 8127 patients were included: clopidogrel (n = 6872), prasugrel (n = 605), ticagrelor (n = 181), and switch (n = 469). Treatment with prasugrel was associated with the lowest risk of MACE using multivariate regression (odds ratio [OR] = 0.57; 95% CI = 0.36-0.92; P = 0.02). In the propensity score-matched analysis, only the prasugrel group was associated with a lower risk of MACE compared with the clopidogrel group. Clopidogrel was associated with the lowest risk of major bleeding using multivariate regression (OR = 0.64; 95% CI = 0.42-0.98; P = 0.042). Both ticagrelor (hazard ratio [HR] = 2.00; 95% CI = 1.11-3.59) and the switch groups (HR = 1.65; 95% CI = 1.09-2.50) were associated with a greater risk of major bleeding compared with clopidogrel. However, no differences were found in the propensity score-matched analysis. CONCLUSIONS: Dual antiplatelet therapies differed in both MACE and bleeds in a real-world setting of PCI. Prasugrel was associated with fewer MACE, whereas clopidogrel had fewer major bleeding events.

Epitaxial graphene quantum dots for high-performance terahertz bolometers.

Light absorption in graphene causes a large change in electron temperature due to the low electronic heat capacity and weak electron-phonon coupling. This property makes graphene a very attractive material for hot-electron bolometers in the terahertz frequency range. Unfortunately, the weak variation of electrical resistance with temperature results in limited responsivity for absorbed power. Here, we show that, due to quantum confinement, quantum dots of epitaxial graphene on SiC exhibit an extraordinarily high variation of resistance with temperature (higher than 430 MΩ K(-1) below 6 K), leading to responsivities of 1 × 10(10) V W(-1), a figure that is five orders of magnitude higher than other types of graphene hot-electron bolometer. The high responsivity, combined with an extremely low electrical noise-equivalent power (∼2 × 10(-16) W Hz(-1/2) at 2.5 K), already places our bolometers well above commercial cooled bolometers. Additionally, we show that these quantum dot bolometers demonstrate good performance at temperature as high as 77 K.

Tunable Terahertz Hybrid Metal-Graphene Plasmons.

We report here a new type of plasmon resonance that occurs when graphene is connected to a metal. These new plasmon modes offer the potential to incorporate a tunable plasmonic channel into a device with electrical contacts, a critical step toward practical graphene terahertz optoelectronics. Through theory and experiments, we demonstrate, for example, anomalously high resonant absorption or transmission when subwavelength graphene-filled apertures are introduced into an otherwise conductive layer. These tunable plasmon resonances are essential yet missing ingredients needed for terahertz filters, oscillators, detectors, and modulators.

Indium Tin Oxide Nanowire Networks as Effective UV/Vis Photodetection Platforms.

We demonstrate that indium tin oxide nanowires (ITO NWs) and cationic polymer-modified ITO NWs configured in a network format can be used as high performing UV/vis photodetectors. The photovoltage response of ITO NWs is much higher than similarly constructed devices made from tin oxide, zinc tin oxide, and zinc oxide nanostructures. The ITO NW mesh-based devices exhibit a substantial photovoltage (31-100 mV under illumination with a 1.14 mW 543 nm laser) and photocurrent (225-325 µA at 3 V). The response time of the devices is fast with a rise time of 20-30 µs and a decay time of 1.5-3.7 ms when probed with a 355 nm pulsed laser. The photoresponsivity of the ITO NW devices ranges from 0.07 to 0.2 A/W at a 3 V bias, whose values are in the performance range of most commercial UV/vis photodetectors. Such useful photodetector characteristics from our ITO NW mesh devices are attained straightforwardly without the need for complicated fabrication procedures involving highly specialized lithographic tools. Therefore, our approach of ITO NW network-based photodetectors can serve as a convenient alternative to commercial or single NW-based devices.

Electron-hole transport and photovoltaic effect in gated MoS2 Schottky junctions.

Semiconducting molybdenum disulfphide has emerged as an attractive material for novel nanoscale optoelectronic devices due to its reduced dimensionality and large direct bandgap. Since optoelectronic devices require electron-hole generation/recombination, it is important to be able to fabricate ambipolar transistors to investigate charge transport both in the conduction band and in the valence band. Although n-type transistor operation for single-layer and few-layer MoS2 with gold source and drain contacts was recently demonstrated, transport in the valence band has been elusive for solid-state devices. Here we show that a multi-layer MoS2 channel can be hole-doped by palladium contacts, yielding MoS2 p-type transistors. When two different materials are used for the source and drain contacts, for example hole-doping Pd and electron-doping Au, the Schottky junctions formed at the MoS2 contacts produce a clear photovoltaic effect.

Electrical properties and memory effects of field-effect transistors from networks of single- and double-walled carbon nanotubes.

We study field-effect transistors made of single- and double-walled carbon nanotube networks for applications as memory devices. The transfer characteristics of the transistors exhibit a reproducible hysteresis which enables their use as nano-sized memory cells with operations faster than 10 ms, endurance longer than 10(+4) cycles and charge retention of a few hours in air. We propose water enhanced charge trapping at the SiO(2)/air interface close to the nanotubes as the dominant mechanism for charge storage. We show that charge storage can be improved by limiting exposure of the device to air.