Screening Corrections Research Articles

Surgical approach to the posterior fossa in children, including anesthetic considerations and complications: The prone and the sitting position. Technical note

IntroductionMedulloblastoma (MB) in children is, in most cases, a midline lesion located in the posterior fossa, with a high tendency to invade the fourth ventricle (and sometimes its floor). MethodsIn this technical note, we present both the sitting and the prone position for children with medulloblastoma. These positions will be described together by deliberately deciding not to oppose one against the other. The park bench position, seldom used in pediatric neurosurgery is not described here. The latter procedure can be useful, however, for MB located more laterally or within the cerebellopontine angle. ResultsThe aim of this technical note is to provide the reader with a step by step procedure (from installation to closure), at least from the author's point of view. A special focus regarding anesthetic considerations is also provided. This anesthesia requires perfect coordination and communication between both the anesthetic and surgical teams. Complications of posterior fossa surgery are mentioned as well. Some of the advantages and disadvantages of each positions are mentioned. ConclusionOnly careful installation, respect of certain surgical principles (careful attention of the vermis and dentate nuclei for example), knowledge of anatomy, closure and perioperative monitoring, screening and immediate correction of potentially devastating complications will enable surgeons to obtain the best results from their surgery.

Nuclear effects in proton transport and dose calculations

Interactions of protons with nuclei are modeled in a form that is suitable for Monte Carlo simulation of proton transport. The differential cross section (DCS) for elastic collisions of protons with neutral atoms is expressed as the product of the Rutherford DCS, which describes scattering by a bare point nucleus, and two correction factors that account for the screening of the nuclear charge by the atomic electrons and for the effect of the structure of the nucleus. The screening correction is obtained by considering the scattering of the projectile by an atom with a point nucleus and the atomic electron cloud described by a parameterization of the Dirac-Hartree-Fock-Slater self-consistent electron density. The DCS for scattering by this point nucleus atom is calculated by means of the eikonal approximation. The nuclear correction to the DCS for elastic collisions is calculated by conventional partial-wave analysis with a global optical-model potential that describes the interaction with the bare nucleus. Inelastic interactions of the projectile with target nuclei are described by using information from data files in ENDF-6 format, which provide cross sections, multiplicities, and angle-energy distributions of all reaction products: light ejectiles (neutrons, protons, …), gammas, as well as recoiling heavy residuals. These interaction models and data have been used in the Monte Carlo transport code penh, an extension of the electron-gamma code penelope, which originally accounted for electromagnetic interactions only. The combined code system penh/penelope performs simulations of coupled electron-photon-proton transport. A few examples of simulation results are presented to reveal the influence of nuclear interactions on proton transport processes and on the calculation of dose distributions from proton beams.

Screening corrections to electron capture rates and resulting constraints on primordial magnetic fields

We explore screening effects arising from a relativistic magnetized plasma with applications to Big Bang nucleosynthesis (BBN). %Specifically, due to their small magnetic moments, energies of electrons and positrons can be easily quantized via Landau quantization. The screening potential which depends on the thermodynamics of charged particles in the plasma is altered by the magnetic field. We focus on the impact of screening on the electron capture interaction. Taking into account the correction in BBN arising from a homogeneous primordial magnetic field (PMF), we constrain the epoch at which the PMF was generated and its strength during BBN. Considering such screening corrections to the electron capture rates and using up-to-date observations of primordial elemental abundances, we also discuss the possibility of solving the problem of under-estimation of the deuterium abundance. We find for certain values of the PMF strength predicted D and $^4$He abundances are both consistent with the observational constraints.

Inner screening corrections to the Debye interaction in hot/dense plasmas in the vicinity of the bound – free transitions

Considering hot/dense plasmas strongly ionized and still retaining hydrogenic bound states (1 ≤ z ≤ 6), we focus attention on the delocalization features of ion-electron orbitals, such as wide spreading and attending of pertaining wave functions close to the free bound transition. A systematic embedding process of increasingly excited states is shown to introduce short-range corrections to the Debye potential, while highlighting blue line shifts relative to initial Debye data. D-Dependence of a ion-electron dipole bound in a Debye potential evaluated. The probability of presence r2 R2nl (r) of the electron around its bounding ion are plotted. Orbitals 1S and 2S in a 3-component hydrogen plasma with T = 8.62 eV and ne =2.24x1023 cm-3 are calculated. A classical – partially degenerate difference is shown. Normalized solutions to quantum – mechanical equation for partially ionized hydrogen are obtained. Also levels deeply involved in the bound-free transition, close to vanishing in the continuum are shown.

Screening effects on resonant thermonuclear reaction rates

The reaction rate of several astrophysically important nuclear reactions is dominated by the contribution of narrow resonances at the astrophysically most effective energies. In the stellar plasma the partial width of the resonances in the entrance channel is modified due to screening corrections. This effect, so far ignored in stellar reaction network calculations, reduces the conventional Salpeterscreening enhancement of the reaction rate. We derive analytical screening correction factors for the contributions of narrow resonances to the stellar reaction rate and discuss the effects for UC (a, j)lsO, 150(a,7)19 Ne and other reactions of relevance to explosive hydrogen burning

Retrieval of Snow Properties from the Sentinel-3 Ocean and Land Colour Instrument

The Sentinel Application Platform (SNAP) architecture facilitates Earth Observation data processing. In this work, we present results from a new Snow Processor for SNAP. We also describe physical principles behind the developed snow property retrieval technique based on the analysis of Ocean and Land Colour Instrument (OLCI) onboard Sentinel-3A/B measurements over clean and polluted snow fields. Using OLCI spectral reflectance measurements in the range 400–1020 nm, we derived important snow properties such as spectral and broadband albedo, snow specific surface area, snow extent and grain size on a spatial grid of 300 m. The algorithm also incorporated cloud screening and atmospheric correction procedures over snow surfaces. We present validation results using ground measurements from Antarctica, the Greenland ice sheet and the French Alps. We find the spectral albedo retrieved with accuracy of better than 3% on average, making our retrievals sufficient for a variety of applications. Broadband albedo is retrieved with the average accuracy of about 5% over snow. Therefore, the uncertainties of satellite retrievals are close to experimental errors of ground measurements. The retrieved surface grain size shows good agreement with ground observations. Snow specific surface area observations are also consistent with our OLCI retrievals. We present snow albedo and grain size mapping over the inland ice sheet of Greenland for areas including dry snow, melted/melting snow and impurity rich bare ice. The algorithm can be applied to OLCI Sentinel-3 measurements providing an opportunity for creation of long-term snow property records essential for climate monitoring and data assimilation studies—especially in the Arctic region, where we face rapid environmental changes including reduction of snow/ice extent and, therefore, planetary albedo.

Accuracy of analytical theories for relativistic bremsstrahlung

Angular and energy-dependent photon distributions emitted from $50\text{\ensuremath{-}}\mathrm{keV}$ to $2.5\text{\ensuremath{-}}\mathrm{MeV}$ electrons colliding with targets ranging from Cu to Pb are calculated using a consistent higher order analytical approach as well as the exact Dirac partial-wave theory. By comparison with exact numerical results for neutral atoms, the validity of the Olsen-Maximon-Wergeland additivity rule for handling the screening correction is probed, and its applicability for collision energies above $100\phantom{\rule{0.16em}{0ex}}\mathrm{keV}$, if the photon frequency and emission angle are both small, is established. The comparison for a point-Coulomb field, aimed at testing the accuracy of the underlying analytical theory, reveals in most cases a deviation below $60%$ for Au, decreasing with target nuclear charge down to $10--20%$ for Cu.

Features of glycemic status and risk factors in patients with coronary artery disease and type 2 diabetes in Azerbaijan population

Aim . To study the associations of glycemic control with risk factors of cardiovascular diseases and parameters of life quality in patients with coronary artery disease (CAD) and type 2 diabetes (T2D). Material and methods . In single-step cross-sectional clinical-epidemiology cohort study were involved 142 patients with CAD and T2D between the ages of 35 and 69. The patients answered the questions of “ARiC” questioner about their socio-demographic status, behavioral risk factors and quality of life. We measured anthropometric indicators, determined level of glucose and glycated hemoglobin in venous plasma. Results. It was determined no statistically significant relationship between level of glycemic status and patients ages, education level, occupation and family status, physical activities, body mass index, smoking habit, feeding disorder, anxiety, stress conditions. Such life quality parameters as moving, taking care of oneself, daily activities, pain or feeling discomfort also didn’t have associations with glycemic status. In the background of abdominal obesity (p=0,034), using alcohol (p=0,045), depressive conditions (p=0,036) and such life quality parameters as anxiety or depression (p=0,039) control of glycaemia was disturbed. As a result, in 28,7% of patients with poor glycemic control compared with previous years, there was no change in the condition of patients, and 55,7%, on the contrary, worsened. An increase in the duration of diabetes and chronic hyperglycemia adversely affected the course of the disease (F=4,3, p=0,041 and F=18,3, p<0,001, respectively), and insufficient control of the glycemic status was accompanied by tachycardia. Conclusion . In patients with CHD and T2D, alcohol intake, depressive conditions, abdominal obesity and an increase in the duration of diabetes were accompanied by worsening of glycemic control, which led to deterioration in the life quality parameters. Timely screening and adequate correction of these risk factors will prevent complications, mortality and disability, as well as reduce healthcare costs associated with these diseases.

PNS15 PRAGMATIC ARTIFICIAL INTELLIGENCE-BASED REFERENCE SCREENING IN SYSTEMATIC REVEIWS. ARE TWO ROBOTS BETTER THAN ONE?

The use of natural language processing (NLP) to automate the systematic review (SR) screening process is of considerable interest. The reported precision of most approaches is inadequate to permit their use in autonomous reference exclusion. This study sought to measure the performance when running two parallel NLP classifiers (Naïve Bayes [NB] and Support Vector Machine [SVM]) to screen for exclusion, to compare error rates to humans using a dual screening process and estimate potential time savings. We examined screening data from three human-completed SRs (two health technology assessments and one economic review). Data were available for screening decisions, corrections and screening time. For each SR, we randomly selected 10% of screened references to train the NLP classifiers on inclusion/exclusion decisions. The classifiers then independently screened references for consensus exclusion. Where there was no consensus, references remained unreviewed. Error rates (false exclusions) were calculated for the machine-indicated exclusions and compared to the human-screened results. Time saved through automation was calculated by multiplying the median screening time per reference by the number of references automatically screened. The three SRs contained 12,229 screened references. The NLP classifiers achieved consensus exclusion for 3706/7969 (47%), 252/944 (27%) and 1448/3316 (44%) records. NLP error rates by project were 0.05%, 0% and 0%, whereas human error rates (weighted averages) were 1.55%, 1.06% and 0.45%. Automated title and abstract screening saved approximately 76.14, 3.5 and 32.18 hours respectively. Across these three reviews, NB/SVM classifiers, running independently, achieved error rates that were lower than the human reviewers. However, both the classifiers and humans produced false exclusions, reinforcing dual screening as a best practice. More research is required to test the combined NB/SVM classifiers as a second screener or its use in autonomous title and abstract screening to exclude irrelevant references.

Analytic calculations of electron–nucleus bremsstrahlung cross sections above a few MeV including higher-order corrections and multiple scattering in the target

Calculations of the elementary process of electron–nucleus bremsstrahlung employing a partial–wave expansion of the initial and final electron wave functions are exact and offer results that match the experimental data, but they become impractical for increasingly higher electron energies, especially in some regions of the emitted photon phase space. Here we take the opposite approach and use analytic expressions based on the Olsen–Maximon–Wergeland additivity rule, valid above few MeV, to decouple the calculation of the screening and Coulomb corrections. The former is obtained from the first Born approximation, while the latter is evaluated within the formalism of the Furry–Sommerfeld–Maue wave functions using the leading–order expression by Elwert and Haug and the next–to–leading–order corrections by Roche, Ducos, and Proriol, which is presently the best way to calculate cross sections for electrons with energies in the range of hundreds of MeV. A detailed discussion of the approximations involved and an extensive comparison with experimental data have been published in previous works. Here we focus on the numerical procedures that have been developed and on the stringent cross checks that have been performed to ensure the accuracy of the results. Published benchmark calculations for bremsstrahlung in a pure Coulomb field, that stop at 100 keV, are extended here to 100 MeV by making available selected values that could be used by other independent researchers to validate their programs. We also discuss the numerical details of the procedure adopted to convolve the bremsstrahlung cross section with the impinging electron angular distribution due to multiple scattering in the target.

Congenital ear deformity screening and non-invasive correction effect analysis

Objective:To synchronously perform external auricle examination during neonatal hearing screening, follow up auricle deformity with neonatal disease screening system, and calculate the incidence of auricle deformity, self-healing rate, correction rate, incidence of complications and the relationship with hearing loss in Zhuhai area. Method:According to the diagnostic criteria of auricle deformity, the newborns in Zhuhai Maternal and Child Health Hospital were examined on the spot within 2 months. The deformity auricle was registered and uploaded into the newborn hearing screening system. The newborns were followed up by short message notification 7 days after birth, and then compared with the photo uploading system again. At 14 days, the ears of those who could not self-heal were went on non-invasive correction, and collect of relevant data for summary analysis. Result:Among the 1 073 newborns(2 146 ears), 26(37 ears) with malformed ears were treated with auricular pattern correction.The corrective rates of newborns less than 14 days, 14-30 days and 31-60 days were 95%, 90% and 87% respectively, and the incidence of complications were 50%, 58% and 69%, respectively. Conclusion:The incidence of auricular deformities in neonates is high. The earlier correction the better. The ear deformity can be detected at the earliest stage and missed diagnosis can be avoided by simultaneous hearing screening and ear deformity screening. During the window period of 7-14 d, by monitoring the self-healing rate of the affected ear excessive medical correction can be avoided. By hearing screening system statistics, ear shape malformation is not directly related to hearing loss.

Dense-plasma screening effects on the thermonuclear 3H(2H,n)4He fusion reaction

We investigate the dense-plasma screening effects on the thermonuclear [Formula: see text] fusion reaction. In this study, we focus on the strong screening with the weak quantum effect in the thermonuclear region. At the first step, we calculate the cross-section and [Formula: see text]-factor of the bare [Formula: see text] fusion using a model inspired by halo/cluster effective field theory approach. The evaluations of the plasma screening corrections in the [Formula: see text]-factor and the reaction rate would be studied in the next step. Concentrating on the thermonuclear region, we use the Salpeter’s potential justifying the electron cloud around reactant as an incompressible and uniformly charged liquid drop. Finally, we show the changes in the [Formula: see text]-factor and production rate due to the screening electrons.

Biochemical screen correction possibilities in patients with non-alcoholic fatty liver disease with diabetes mellitus

The rationale for this study is the controversial data regarding the efficacy of hepatoprotectors and antioxidants for lipid profile correction in non-alcoholic fatty liver disease, the prevalence of which is increasing especially in association with diabetes mellitus. We examined 100 non-alcoholic fatty liver disease patients (40–75 years old) with concomitant type 2 diabetes mellitus (n = 73) or without it (n = 27), the groups were standardized by age and gender. In patients with non-alcoholic fatty liver disease with diabetes mellitus we revealed significantly higher rates of total cholesterol, triglycerides and atherogenic factor in association with a significantly lower high-density lipoproteins level versus the group of patients without concomitant diabetes. We recommended the modification of lifestyle as basic management of their condition to all patients, hypoglycemic therapy with metformin to persons with concomitant diabetes mellitus and rosuvastatin to patients with non-alcoholic fatty liver disease without diabetes. In addition, 25 patients received essential phospholipids (2 caps. 3 times a day) and omega-3 polyunsaturated fatty acids (1000 mg per day) for 3 months; 26 patients – α-lipoic acid (600 mg daily) for 3 months, 22 patients received rosuvastatin (10 mg daily), 27 patients with non-alcoholic fatty liver disease without diabetes mellitus received rosuvastatin (10 mg daily). We evaluated the treatment efficiency after 3 months treatment, and the remote consequences – 12 months after the start of combined treatment. After 3 months, the alanine-aminotransferase rate had decreased by 15.1% in the group taking combined essential phospholipids and ω3-polyunsaturated fatty acids and by 12.9% in the group taking alpha-lipoic acid, which was significantly larger than in the rosuvastatin group (7.5%); gamma-glutamate transpeptidase level decreased by 16.7%, 18.7% and 9.4% respectively indicating anticholestatic and hepatoprotective effect of both proposed treatment combinations. The same tendency of cytolysis and cholestasis processes inhibition was observed after 12 months as well. In conclusion, the combination of standard treatment with antioxidant and hepatoprotective agents (omega-3 polyunsaturated fatty acids with essential phospholipids or only alpha-lipoic acid) promotes both cytolysis and cholestasis syndromes inhibition in non-alcoholic fatty liver disease patients with concomitant type 2 diabetes mellitus.

Neonatal ECG screening and QT correction: the march towards consistency and accuracy.

Neonatal ECG screening and QT correction: the march towards consistency and accuracy.

Solar Models with Dynamic Screening and Early Mass Loss Tested by Helioseismic, Astrophysical, and Planetary Constraints

The faint young Sun paradox remains an open question. Presented here is one possible solution to this apparent inconsistency, a more massive early Sun. Based on conditions on early Earth and Mars, a luminosity constraint is set as a function of mass. We examine helioseismic constraints of these alternative mass-losing models. Additionally, we explore a dynamic electron screening correction in an effort to improve helioseismic agreement in the core of the an early mass-losing model.

Effects of special exercise programs on functional movement screen scores and injury prevention in preprofessional young football players

To increase movement capacity and to reduce injury risk in young soccer players by implementing a special functional exercise program based on functional movement screen (FMS) and correctives. 67 young male athletes 14–19 years of age from a Super League Football Club Academy participated in the study. Functional movement patterns were evaluated with FMS assessment protocol. Deep squat, hurdle step, inline lunge, shoulder mobility, active straight leg raise, trunk stability push-up, and rotatory stability were examined in FMS. Considering the FMS scores the number of intervention and control groups were defined as 24 and 43, respectively. Intervention program was composed of 1 hr twice a week sessions in total of 12 weeks with 4 weeks of mobility, 4 weeks of stability, and 4 weeks of integration exercises. At the end of 12-week intervention and control groups were re-evaluated with FMS protocol. Contact and noncontact sports injuries recorded during one season. In intervention group there was statistically significant difference in increase in total FMS scores (P<0.01), deep squat (P≤0.001), hurdle step (P<0.05), inline lunge (P<0.01), and trunk stability push-up (P<0.01). In control group total FMS, deep squat, and trunk stability push-up scores increased with a statistical difference (P<0.01, P<0.05, P≤0.01, respectively). The incidence of noncontact injury in control group was higher than intervention group (P<0.05). Periodic movement screening and proper corrections with functional training is valuable in order to create better movement capacity to build better physical performance and more effective injury prevention.

Photodegradation of sulfathiazole under simulated sunlight: Kinetics, photo-induced structural rearrangement, and antimicrobial activities of photoproducts

Photolysis is a core natural process impacting the fate of some sulfonamide antibiotics in sunlit waters. In this study, sunlight-induced phototransformation of sulfathiazole was investigated. A photolytic quantum yield of 0.079 was obtained in buffered water (pH = 8.0). Different natural organic matter isolates inhibited the photolysis of sulfathiazole by light screening effect. A kinetic model was developed to predict the photodegradation rate of sulfathiazole using the light screening correction factor of the water matrix in the wavelength range of 300–350 nm. An isomeric photoproduct of sulfathiazole with a longer retention time was observed on liquid chromatography. Based on its MS/MS spectra and absorption characteristics, the isomer was postulated as 2-imino-3-(p-aminobenzenesulfinyl-oxy)-thiazole. A reaction mechanism for the photo-cleavage and photo-induced structural rearrangement was proposed. The formation mechanism of the isomer was supported by photochemical experiments spiking synthetic 2-aminothiazole; while the formation kinetics were treated with a partly-diffusion-controlled model. The three identified products showed significantly enhanced photo-stability. Antimicrobial assay of irradiated sulfathiazole solutions with Escherichia coli indicated little antimicrobial potency ascribed to photoproducts. This study demonstrates the efficacy of sunlight in rapidly degrading sulfathiazole at a predictable rate, leading to photoproducts of low antimicrobial potency. The mass spectrometry and mechanistic work described here are new insights into the photochemistry of sulfonamides.

Inelastic nuclear screening for different secondaries produced in p+Pb collisions at LHC energy

We calculate the inclusive spectra of secondaries produced in soft (minimum-bias) pPb collisions in the framework of the quark-gluon string model at LHC energy, by taking into account the inelastic screening corrections (percolation effects). The role of these effects is expected to be very large at the very high energies, and they should decrease the spectra more than 2 times in the midrapidity region at ${\sqrt{s}}_{NN}=5\text{ }\text{ }\mathrm{TeV}$.

Le syndrome coronaire aigu avec sus-décalage du segment ST chez la femme

In France, coronary disease is responsible for 11.9 deaths/100,000 women aged 35 to 74 years old every year. In France, the number of hospitalizations and deaths for myocardial infarction (MI) increases more significantly in women, particularly under 65. To date, women with MI were 5–10 years older than men, with more risk factors and comorbidities, especially regarding diabetes, high blood pressure and lipid profile. However, a recent comparative study of the FAST-MI registry notes a change in the characteristics of these patients with more and more young women, active smoking and obesity. Their symptoms include more often atypics ones. They also have the particularity of a higher frequency of MI without obstructive lesion. Though, even at the same age, women have a worse prognosis with significantly higher mortality rate, especially early, in-hospital, than those of men. However, there are means to implement in order to reduce complications rate and improve the prognosis through information campaign and primary prevention screening and appropriate care and correction of risk factors. It is also important to raise awareness of general population and care actors about women MI risk even young, about its atypical forms and the necessity of to rapid and aggressive care processes. A better understanding of specific pathophysiological mechanisms appears mandatory and should be supported by prospective dedicated studies.

Roles of singlet oxygen and dissolved organic matter in self-sensitized photo-oxidation of antibiotic norfloxacin under sunlight irradiation

Many fluoroquinolone (FLQ) antibiotics undergo rapid photodegradation in sunlit waters and form multifaceted photo-products. The high photodegradation rate is primarily ascribed to their photosensitizing properties. Though widely studied, the photo-reaction pathways are not completely revealed; photo-products mediated by different reactive oxygen species are not identified. In our study, photo-degradation of fluoroquinolone norfloxacin was investigated. A rapid degradation in buffered water was observed with a first-order rate constant of 2.45/hr and a quantum yield of 0.039. After light screening correction, selected DOMs (5 mg C/L) slightly enhanced the photodegradation rate with the exception of Suwannee river hydrophobic organic matter (SR-HPO). Three major photo-products were identified using high resolution mass spectrometry (HRMS). With 1O2 dark formation and competitor experiments, norfloxacin self-sensitized 1O2 was found to oxidize norfloxacin by inducing its piperazine chain cleavage. DOMs exhibited a dual role by inhibiting the 1O2-mediated reaction while enhancing the heterolytic defluorination pathway. DOMs were proposed to enhance heterolytic defluorination by donating electron to triplet state FLQ, this proposal was supported with specific UV absorbance (SUVA) as an indicator for the abundance of π bonds. Fluoride formation indicated a 79% elimination ratio of fluorine, an important functional group for antimicrobial activity. This work provides important new insights into the photochemical fate of fluoroquinolone antibiotics in natural water.