Sum Of Charges Research Articles

Electrostatics affects formation of Watson-Crick complex between DNA bases in monolayers of nucleolipids deposited at a gold electrode surface

Chronocoulometry was applied to determine charge in a monolayer of nucleolipid (1,2-dipalmitoyl-sn‑glycero-3-(cytidine diphosphate)) deposited at a gold electrode surface. The immersion method was used to measure the potential of zero charge of the interface (Epzci), which is a sum of charge on the monolayer of the nucleolipid and charge on the gold surface. Photon polarization infrared reflection absorption spectroscopy (PM-IRRAS) was used to determine formation of the Watson-Crick complex between terminal cytidine moiety of the nucleolipid and guanine (its complementary base) added to the solution. The combination of electrochemical and spectroscopic studies allowed one to demonstrate that the Watson-Crick complex is formed when the interface is positively charged. The potential applied to the electrode affects not only the complex formation but also orientation of the cytosine moiety. The complex is formed when the cytosine moiety is oriented assuming a small angle with respect to the electrode surface.

Facile Method for Constructing Lewis (Electron Dot) Structures

A simple method to determine Lewis electron dot structures and formal charges without a need to sum all of the valence electrons, reorganize electron pairs, draw and pair up individual electrons, or remember a formal charge formula is described. The formal charge is determined by the group number (number of valence electrons) and the number of bonds, with the sum of formal charges then being equal to the total charge. This leads directly to a valid Lewis structure. The facility of the procedure allows the student to focus more on the chemical aspects of deciding which valid Lewis structure (or structures) is the correct or most important one.

Cooperative Operation Schedules of Energy Storage System and Demand Response Resources Considering Urban Railway Load Characteristic under a Time-of-Use Tariff

This paper proposes an algorithm for the cooperative operation of air conditioning facilities and the energy storage system (ESS) in railway stations to minimize electricity. Unlike traditional load patterns, load patterns of an urban railway station can peak where energy charge rates are not high. Due to this possibility, if applying the traditional peak-reduction algorithm to railway loads, energy changes can increase, resulting in higher electricity bills. Therefore, it is required to develop a new method for minimizing the sum of capacity charges and energy charges, which is a non-linear problem. To get a feasible solution for this problem, we suggest an algorithm that optimizes the facility operation through two optimizations (primary and secondary). This method is applied to the air-quality change model for operating air conditioning facilities as demand-response (DR) resources in railway stations. This algorithm makes it possible to estimate operable DR capacity every hour, rather than calculating the capacity of DR resources conservatively in advance. Finally, we perform a simulation for the application of the proposed method to the operation of DR resources and ESS together. The simulation shows that electricity bills become lowered, and the number of charging and discharging processes of ESS is also reduced.

Monitoring electron energies during FLASH irradiations

When relativistic electrons are used to irradiate tissues, such as during FLASH pre-clinical irradiations, the electron beam energy is one of the critical parameters that determine the dose distribution. Moreover, during such irradiations, linear accelerators (linacs) usually operate with significant beam loading, where a small change in the accelerator output current can lead to beam energy reduction. Optimisation of the tuning of the accelerator’s radio frequency system is often required. We describe here a robust, easy-to-use device for non-interceptive monitoring of potential variations in the electron beam energy during every linac macro-pulse of an irradiation run. Our approach monitors the accelerated electron fringe beam using two unbiased aluminium annular charge collection plates, positioned in the beam path and with apertures (5 cm in diameter) for the central beam. These plates are complemented by two thin annular screening plates to eliminate crosstalk and equalise the capacitances of the charge collection plates. The ratio of the charge picked up on the downstream collection plate to the sum of charges picked up on the both plates is sensitive to the beam energy and to changes in the energy spectrum shape. The energy sensitivity range is optimised to the investigated beam by the choice of thickness of the first plate. We present simulation and measurement data using electrons generated by a nominal 6 MeV energy linac as well as information on the design, the practical implementation and the use of this monitor.

Harmonic Surface Mapping Algorithm for Electrostatic Potentials in an Atomistic/Continuum Hybrid Model for Electrolyte Solutions

Simulating charged many-body systems has been a computational demanding task due to the long-range nature of electrostatic interaction. For the multi-scale model of electrolytes which combines the strengths of atomistic/continuum electrolyte representations, a harmonic surface mapping algorithm is developed for fast and accurate evaluation of the electrostatic reaction potentials. Our method reformulates the reaction potential into a sum of image charges for the near-field, and a charge density on an auxiliary spherical surface for the far-field, which can be further discretized into point charges. Fast multipole method is used to accelerate the pairwise Coulomb summation. The accuracy and efficiency of our algorithm, as well as the choice of relevant numerical parameters are demonstrated in detail. As a concrete example, for charges close to the dielectric interface, our method can improve the accuracy by two orders of magnitudes compared to the Kirkwood series expansion method.

Studies of Quark and Gluon Contributions to Jets using Jet Charge Measurements in pp and PbPb Collisions

Jet charge, defined as the momentum-weighted sum of the electric charges of particles inside a jet is sensitive to the electric charge of the initiating parton and can be used to study the color charge dependence of the parton energy loss in the QGP. In this paper, the first measurements of jet charge in heavy-ion collisions are presented using lead-lead (PbPb) collision data and compared to results from proton-proton (pp) data at the same collision energy. The measurements are unfolded for detector and background effects and are studied differentially in pT and additionally as a function of collision centrality in PbPb collisions. We also present a template fitting technique for estimating the fractions of quark- and gluon-initiated jets in pp and PbPb collisions based on Monte Carlo templates. This analysis uses pp and PbPb collision data collected by the CMS experiment at sNN=5.02TeV.

Мікрокулонометр – вимірювач електричних зарядів

The most difficult problem in the laboratory practice of the educational process for the demonstration of electrostatics and electromagnetism is the measurement of electric charges on the surface of bodies and in the airspace of the environment. The fundamental property of electric charges is determined by their type, which are conditionally called positive and negative, they are attracted or repelled, have an electromagnetic interaction. Characterized by an elementary charge i.e. the smallest value of electric charge, regardless of type. The electric charge can take only a discrete value proportional to the smallest charge, which can only be expressed as an integer regardless of the type of charge. Depending on the surface on which they are located, they can have different concentrations, which can be described by linear, surface or bulk density. Electric charges are subject to the law of conservation of charges – the sum of charges in an isolated system is constant. Measurement of electric charges is complex, devices – galvanometers and electroscopes, which are used for this purpose, require certain conditions that are not always convenient to use, do not provide the necessary accuracy of measurement. Methods and devices using the circuitry of a microcoulometer for measuring electric charges in electrostatics and electromagnetism, which is built on a modern element base with the use of operational amplifiers and microcontrollers, are proposed.

Spiral phase plate with multiple singularity centers

We investigate a multispiral phase plate (MSPP) with multiple centers of phase singularity arbitrarily located in the MSPP plane. Equations to describe the topological charge of an optical vortex in the initial plane immediately behind the MSPP and orbital angular momentum (OAM) normalized relative to the beam power are derived. The topological charge in the initial plane is found as a sum of the topological charges of all singularities if their centers are located inside a finite-radius circular aperture. If the phase singularity centers are partially located on the boundary of a circular diaphragm limiting the MSPP, the total topological charge is found as the sum of all singularities divided by 2. Total OAM that the vortex carries depends on the location of the singularity centers: the farther from the center of the plate the singularity center is located, the smaller is its contribution to the OAM. If all singularity centers are located on the boundary of the diaphragm limiting MSPP, then the OAM of the vortex beam equals zero, although in this case the topological charge of the beam is nonzero.

Measurement of quark- and gluon-like jet fractions using jet charge in PbPb and pp collisions at 5.02 TeV

The momentum-weighted sum of the electric charges of particles inside a jet, known as jet charge, is sensitive to the electric charge of the particle initiating the parton shower. This paper presents jet charge distributions in sqrt{s_{mathrm{NN}}} = 5.02 TeV lead-lead (PbPb) and proton-proton (pp) collisions recorded with the CMS detector at the LHC. These data correspond to integrated luminosities of 404 μb−1 and 27.4 pb−1 for PbPb and pp collisions, respectively. Leveraging the sensitivity of the jet charge to fundamental differences in the electric charges of quarks and gluons, the jet charge distributions from simulated events are used as templates to extract the quark- and gluon-like jet fractions from data. The modification of these jet fractions is examined by comparing pp and PbPb data as a function of the overlap of the colliding Pb nuclei (centrality). This measurement tests the color charge dependence of jet energy loss due to interactions with the quark-gluon plasma. No significant modification between different centrality classes and with respect to pp results is observed in the extracted quark- and gluon-like jet fractions.

M-Carborane as a Novel Core for Periphery-Decorated Macromolecules.

Closom-C2B10H12 can perform as a novel core of globular periphery-decorated macromolecules. To do this, a new class of di and tetrabranched m-carborane derivatives has been synthesized by a judicious choice of the synthetic procedure, starting with 9,10-I2-1,7-closo-C2B10H10. The 2a-NPA (sum of the natural charges of the two bonded atoms) value for a bond, which is defined as the sum of the NPA charges of the two bonded atoms, matches the order of electrophilic reaction at the different cluster bonds of the icosahedral o-and m- carboranes that lead to the formation of B-I bonds. As for m-carborane, most of the 2a-NPA values of B-H vertexes are positive, and their functionalization is more challenging. The synthesis and full characterization of dibranched 9,10-R2-1,7-closo-carborane (R = CH2CHCH2, HO(CH2)3, Cl(CH2)3, TsO(CH2)3, C6H5COO(CH2)3, C6H5COO(CH2)3, N3(CH2)3, CH3CHCH, and C6H5C2N3(CH2)3) compounds as well as the tetrabranched 9,10-R2-1,7-R2-closo-C2B10H8 (R = CH2CHCH2, HO(CH2)3) are presented. The X-ray diffraction of 9,10-(HO(CH2)3)2-1,7-closo-C2B10H10 and 9,10-(CH3CHCH)2-1,7-closo-C2B10H10, as well as their Hirshfeld surface analysis and decomposed fingerprint plots, are described. These new reported tetrabranched m-carborane derivatives provide a sort of novel core for the synthesis of 3D radially grown periphery-decorated macromolecules that are different to the 2D radially grown core of the tetrabranched o-carborane framework.

Generation of Multiply Charged Protein Anions from Multiply Charged Protein Cations via Gas-Phase Ion/Ion Reactions.

We report a novel charge inversion ion/ion reaction that converts multiply charged protein cations to multiply charged protein anions via a single ion/ion collision using highly charged anions derived from nanoelectrospray ionization (nESI) of hyaluronic acids (HAs). This type of charge inversion reaction is demonstrated with cations derived from cytochrome c, apo-myoglobin, and carbonic anhydrase (CA) cations. For example, the reaction has been demonstrated to convert the [CA+22H]22+ carbonic anhydrase cation to a distribution of anions as high in absolute charge as [CA-19H]19-. Ion/ion reactions involving multiply charged ions of opposite polarity have previously been observed to result predominantly in the attachment of the reactant ions. All mechanisms for ion/ion charge inversion involving low energy ions proceed via the formation of a long-lived complex. Factors that underlie the charge inversion of protein cations to high anionic charge states in reaction with HA anions are hypothesized to include: (i) the relatively high charge densities of the HA anions that facilitate the extraction of multiple protons from the protein leading to multiply charged protein anions, (ii) the relatively high sum of absolute charges of the reactants that leads to high initial energies in the ion/ion complex, and (iii) the relatively high charge of the ion/ion complex following the multiple proton transfers that tends to destabilize the complex.

Jet charge modification in finite QCD matter

Jet production and jet substructure modification in heavy-ion collisions have played an essential role in revealing the in-medium evolution of parton showers and the determination of the properties of strongly-interacting matter under extreme conditions. It is imperative to extend these studies to include flavor tagging and to devise observables that are sensitive to the partonic origin of jets. The average jet charge, defined as the momentum-weighted sum of the electric charges of particles inside the jet, is a proxy of the electric charge of the quark or gluon that initiates the jet. We demonstrate how the factorization framework of soft-collinear effective theory can be generalized to evaluate the jet charge in a dense strongly-interacting matter environment, such as the one produced in nuclear reactions at collider energies. Observables that can separate the contribution of in-medium branching from the trivial isospin effects are identified and their connection to established jet quenching effects is elucidated. We present predictions for the transverse momentum dependence of the jet charge distribution in nucleus-nucleus collisions and its modification relative to the proton case.

Enormous enhancement of molecular ionization at high x-ray intensity

SynopsisThe ultra-intense and ultra-short x-ray pulses provided by X-ray Free-Electron Lasers (XFELs) sequentially ionize molecular samples many times. In this context, we have recently discovered that under intense x-ray radiation the total charge of a molecule is enhanced compared to the sum of charges of its constituent isolated atoms[2, 3]. We report here on new theoretical results[5] for iodobenzene (C6H5I) that show an even stronger ionization enhancement than previously observed for iodomethane (CH3I)[3].

Topological and real charge of Bjerrum defects in ices Ih and Ic

Two mechanisms for the interaction of Bjerrum defects in ices are considered. (i) In the lattice ice models, the defects are topological charges interacting by the entropy of proton disorder. The charge magnitude is calculated by fitting the potential of mean force of a pair of defects (minus log of the simulated 3D distribution function) in the periodic boundary conditions to the Ewald summation energy. (ii) At the atomic level, the effective Coulomb charges for several classical water models are calculated as a sum of Gaussian-smoothed partial charges. The topological charge is equivalent to % of the Bjerrum defect real charge.

Bessel beams formation by hybrid axicons

We present a new type of diffractive optical elements (DOE) – hybrid axicons. The process of formation of identical intensity distributions in focus by different hybrid axicons on the example of Bessel beams is shown. The beams order is determined by the sum of the topological charges of the phase plate (structure charge) and the spiral axicon (zone charge). The results of mathematical modeling of light diffraction on hybrid axicons are presented.

Range-separated tensor decomposition of the discretized Dirac delta and elliptic operator inverse

In this paper, we introduce the operator dependent range-separated (RS) tensor approximation of the discretized Dirac delta function (distribution) in Rd. It is constructed by application of the elliptic operator to the RS tensor representation of the associated Green kernel discretized on the d-dimensional Cartesian grid. The proposed local-global decomposition of the Dirac delta can be applied for solving the potential equations in a non-homogeneous medium when the density in the right-hand side is given by a large sum of pointwise singular charges. As an example of applications, we describe the regularization scheme for solving the Poisson-Boltzmann equation that models the electrostatics in bio-molecules. We show how the idea of the operator dependent RS tensor decomposition of the Dirac delta can be generalized to the closely related problem on range-separated tensor representation of the elliptic resolvent. This approach paves the way for application of tensor numerical methods to elliptic problems with non-regular data. Numerical tests confirm the expected localization properties of the RS tensor approximation of the Dirac delta represented on a tensor grid in 3D.

Diagnostika akutních poruch acidobazické rovnováhy

Traditional diagnostic approach to acute acid-base disorders is based on the assessment of bicarbonate buffer system, in which pH is determined by the ratio of [HCO3-] to pCO2. This, in turn, creates basis for distinguishing metabolic and respiratory disorders, and defines the term “compensation”. The use of electroneutrality advantageously complements the bicarbonate-based approach when dealing with complex acid-base disorders. It is possible to simplify this approach so it can be applied only using mental arithmetics. In principle, the space created by strong ion difference (which can be simplified to [Na+]-[Cl-]) is shared by negative charges on albumin and bicarbonate. In turn, a shrinkage of this space ([Na+]-[Cl-] 36 mM causes alka-losis, as well as a decrease in albumin concentration (for every 10 g/L of albumin, 3 mM is freed to be occupied by [HCO3-]). Lastly, if the sum of negative charges on albumin and [HCO3-] is lower than estimated strong ion difference, an unmeasured anion must be present. This concept is explained on commented case reports.

SAT-138 Predictors and Health Care Expenditures Associated with Recurrent Diabetic Ketoacidosis Admissions in Adults with Type 1 Diabetes

Introduction: Diabetic ketoacidosis (DKA) is a serious complication in patients with type 1 diabetes (T1D). Recurrent DKA admissions have been associated with increased mortality and substantial healthcare costs. In contrast to pediatrics, significantly less attention has been devoted to exploring and addressing recurrent DKA admissions in adults with T1D. We aimed to characterize the adult population of T1D admitted with DKA in Maryland, identify predictors of recurrent DKA admissions, and quantify their associated healthcare costs. Methods: We conducted a cross-sectional study using the Maryland Health Services Cost Review Commission's database, which collects data from all acute care hospitals in the state. We defined DKA using ICD diagnostic codes for ketoacidosis and hyperosmolality in T1D. We selected adult patients (age 20 or above) with T1D who lived in or bordering Maryland and had at least one admission with a primary diagnosis of DKA between January 1, 2012 and December 31, 2017. The predictors analyzed in this study represent patient characteristics from the first DKA admission. The primary outcome was readmission for DKA in the study period. The summation of admission charges was used to calculate DKA healthcare expenditures. Results: There were 6,147 DKA admissions by 3,368 T1D adults admitted in Maryland in the study period. Readmissions occurred in 915 (27%) patients, with 1-3 and >4 readmissions occurring in 700 (76%) and 487 (24%) of these patients, respectively. Overall, the patients admitted with DKA were predominately non-Hispanic (96%) white (45%) or black (45%) men (53%) between the ages 20-39 years old (48%) from areas of low to moderate socioeconomic status (SES). The majority of patients were insured by private (37%) and Medicaid (27%) insurance. The strongest predictors for DKA readmissions were female sex (OR 1.3; 95%CI 1.1-1.6), residing in an area of low SES (OR 1.5; 95% 1.1-2.0), being insured by Medicare (OR 1.7; 95%CI 1.3-2.2), Medicaid (OR 1.5 95%CI 1.2-1.8) or Self-pay/charity (OR 1.5; 95%CI 1.1-1.9), and discharge against medical advice (OR 1.6; 95%CI 1.2-2.3). Older and non-white patients had a reduced odds of readmission. The expenditure of all adult DKA admissions totaled 5.4 billion dollars. While patients who had DKA readmissions consisted of only 27% of those admitted with DKA, their total costs were 59% of these DKA charges at 3.2 billion dollars. Conclusion: There is a high prevalence of recurrent DKA admissions in adults with T1D. Younger patients, women, having non-private insurance and those living in areas of low SES have the highest odds for readmission. Although these patients are a minority, they account for a majority of DKA health expenditures. Further studies are needed to understand drivers of these admissions in order to intervene in this population at high risk for poor outcomes. Supported by a NIH T32 Grant T32 and Saudek Fellowship Award.

Hospital and ED charges for spina bifida care in the United States between 2006 and 2014: Over $2 billion annually.

BackgroundMore children with spina bifida (SB) are surviving into adulthood. Unfortunately, little data exist regarding the economic implications of modern SB care. ObjectiveWe examined economic data from two national databases to estimate the annual nationwide hospital and emergency charges of SB from 2006–14. MethodsWe analyzed the 2006–2014 Nationwide Inpatient Sample (NIS) and Nationwide Emergency Department Sample (NEDS). SB patients were defined using ICD-9-CM codes. Demographic and charge data were obtained from each database. Multiple imputation was used to estimate missing data (1.6% for NIS and 22% in NEDS). The principal outcomes were mean, median, and total charges for encounters each year. ResultsThere were 725,646 encounters for individuals with SB between 2006 and 2014. The average age of captured SB patients who were admitted to a hospital or seen in an ER was 29 years. In 2014, the median charge for inpatient encounters was $31,071 (IQR: $15,947, $63,063) and for ER encounters was $2407.02 (IQR: $1321.91, $4211.35). In total, the sum of charges from all SB-related admissions in 2014 was $1,862,016,217 (95% CI: $1.69 billion, $2.03 billion), while the sum of charges of all SB-related ER encounters in 2014 was $176,843,522 (95% CI: $158 million, $196 million). There was a steady increase in charges over the study period. ConclusionCharges for SB-related inpatient and emergency care in the US in 2014 was in excess of $2 billion in contrast to $1.2 billion in 2006, after adjusting for inflation; this is an impressively high figure for a relatively small number of patients.

Chiral rings for surface operators in 4d and 5d SQCD

Chiral rings of two-dimensional (2,2) theories coupled to 4d mathcal{N} = 2 theories with matter hypermultiplets are studied. Specifically, the vacua of the twisted superpotential of the 2d theories with vanishing sum of matter charges are computed by considering the resolvent of the bulk theory. The solutions to the chiral ring equations are also obtained from the instanton partition function via Higgsing for simple surface operators and via the orbifold description for full surface operators. These 2d/4d coupled theories are lifted to 3d/5d theories and vacua are found similarly in two different methods: by solving the 3d chiral ring equations taking into account the effect of 5d resolvent and by computing the 5d instanton partition function in the presence of a surface operator. We also check the Seiberg-like duality for both 2d/4d and 3d/5d coupled systems with a specific Chern-Simons coefficient for the latter.