Effect of Electron Capture on Spectral Line Broadening in Hot Dense Plasmas.

Accurate calculation of spectral line broadening is important for many hot, dense plasma applications. However, calculated line widths have significantly underestimated measured widths for Δn=0 lines of Li-like ions, which is known as the isolated-line problem. In this Letter, scrutinization of the line-width derivation reveals that the commonly used expression neglects a potentially important contribution from electron-capture. Line-width calculations including this process are performed with two independent codes, both of which removed the discrepancies at temperatures below 10 eV. The revised calculations also suggest the remaining discrepancy scales more strongly with electron temperature than the atomic number as was previously suggested.

Capacity of Abbott RealTime MTB RIF/INH to detect rifampicin- and isoniazid-resistant tuberculosis.

Abbott RealTime MTB RIF/INH Resistance (RT RIF/INH) is a new assay for the detection of resistance to rifampicin (RIF) and isoniazid (INH) in tuberculosis (TB) patients. To evaluate the capacity of RT RIF/INH to detect resistance-associated mutations in target genes. A total of 311 Mycobacterium tuberculosis strains that had been pre-characterised using genotypic methods (GenoType® MTBDRplus, Sanger sequencing) and phenotypic drug susceptibility testing were subjected to DNA extraction on Abbott m2000sp and analysed using RT RIF/INH. Detection of heteroresistant mutations was studied with artificial mixtures of wild-type and mutant DNA. Overall sensitivity and specificity values of RT RIF/INH to detect resistance were respectively 87.2% and 98.4% for RIF and respectively 90.1% and 99.2% for INH. The capacity of RT RIF/INH to detect specific mutations was 100% for katG, inhA and frequent rpoB mutations, and 76% for rare rpoB mutations. Among the latter, two rare mutations were not consistently detected. With heteroresistant samples, RT RIF/INH reported resistance if samples contained at least 75-90% of mutant DNA. RT RIF/INH is a reliable high-throughput assay for the detection of RIF and INH resistance markers. The ability to detect INH resistance also may be of benefit in areas with high rates of INH-resistant, non-multidrug-resistant TB. .

Near-Threshold Cross Sections for Electron and Positron Impact Ionization of Atomic Hydrogen.

Using classical arguments Wannier [Phys. Rev. 90, 817 (1953)PHRVAO0031-899X10.1103/PhysRev.90.817] proposed an electron-impact ionization cross section for neutral atoms to behave as E^{1.127}, where E is the excess energy above threshold. Using similar arguments Klar [J. Phys. B 14, 4165 (1981)JPAMA40022-370010.1088/0022-3700/14/21/027] obtained E^{2.65} to be the corresponding threshold law for positron impact. Recently, Babij et al. [Phys. Rev. Lett. 120, 113401 (2018)PRLTAO0031-900710.1103/PhysRevLett.120.113401] measured near-threshold positron-impact breakup behavior to be similar to that expected for electrons. Using the convergent close-coupling method for the atomic hydrogen target, we examine cross sections at near-threshold energies for electron and positron impact. Contrary to the experiment, the calculated cross sections are found to behave differently for the two projectiles and consistently with the aforementioned threshold laws, despite the entirely quantum nature of these problems. For electron impact, the threshold behavior holds while the total electron spin asymmetry remains constant, whereas for positron scattering the threshold law holds for breakup while the positronium-formation component of the ionization cross section remains constant.

Tuberculosis among migrants in Bishkek, the capital of the Kyrgyz Republic.

Setting: Twenty-two first-line, two second-line and one tertiary health facility in Bishkek, the capital of Kyrgyzstan. Objectives: Among migrants, a marginalised population at risk for acquiring and transmitting tuberculosis (TB), we determined the proportion with TB among all registered TB cases. For those registered at primary-level facilities, we then reported on their demographic and clinical profiles and TB treatment outcomes. Design: This was a retrospective cohort analysis of 2012-2013 programme data. Results: Of 2153 TB patients registered in all health facilities, 969 (45%) were migrants, of whom 454 were registered in first-line facilities. Of these, 27% were cross-border migrants, 50% had infectious TB and 12% had drug-resistant TB. Treatment success was 74% for new cases and 44% for retreatment TB (the World Health Organization target is ⩾85%). Failure in new and retreatment TB patients was respectively 8% and 25%. Twenty-six individuals started on a first-line anti-tuberculosis regimen failed due to multidrug-resistant TB. Eight (25%) of 32 individuals on a retreatment TB regimen also failed. Loss to follow-up was 10% for new and 19% for retreatment TB. Conclusion: Migrants constituted almost half of all TB patients, drug resistance is prevalent and treatment outcomes unsatisfactory. Fostering inter-country collaboration and prioritising rapid TB diagnostics (Xpert® MTB/RIF) and innovative ways forward for improving treatment outcomes is urgent.

Contexte : Vingt-deux structures de santé de premier niveau, deux de second niveau et une de troisième niveau à Bichkek, la capitale du Kirghizstan.Objectifs : Parmi les migrants qui sont une population marginalisée à risque d'acquérir et de transmettre la tuberculose (TB), nous avons déterminé la proportion de migrants atteints de TB parmi tous les cas de TB enregistrés. Pour ceux enregistrés dans des structures de premier niveau, nous exposons leur profil démographique et clinique et les résultats du traitement de la TB.Schéma : Une analyse rétrospective de cohorte des données du programme de 2012 à 2013.Résultats : Sur 2153 patients TB enregistrés dans toutes les structures de santé, 969 (45%) ont été des migrants ; 454 ont été enregistrés dans des structures de premier niveau. Parmi ces derniers, 27% étaient des migrants transfrontaliers, 50% avaient une TB contagieuse et 12% avaient une TB pharmacorésistante. Le taux de succès a été de 74% pour les cas nouveaux et de 44% pour les TB en retraitement (cible de l'Organisation Mondiale de la Santé ⩾85%). Les échecs dans les cas nouveaux et les cas en retraitement ont été respectivement de 8% et de 25%. Vingt-six individus mis sous protocole de traitement de TB de première ligne ont eu un échec dû à une TB multirésistante. Huit (25%) des 32 individus en protocole de retraitement de TB ont également eu un échec. Les taux de perdus de vue ont été de 10% pour les cas nouveaux et de 19% pour les TB en retraitement.Conclusion : Les migrants ont constitué près de la moitié de tous les patients TB, la pharmacorésistance a été prévalent et les résultats du traitement ne sont pas satisfaisants. Il est urgent d'encourager la collaboration entre les pays, de prioriser les diagnostics rapides de TB (Xpert® MTB/RIF) et les manières innovantes d'améliorer les résultats du traitement.

Marco de referencia: Veintidós establecimientos de salud de atención primaria, dos establecimientos de atención secundaria y uno de atención terciaria en Bishkek, la capital de Kirguistán.Objetivos: En los migrantes, una población marginada con riesgo de contraer la tuberculosis (TB) y transmitirla, se determinó la proporción que padecía TB a partir de todos los casos de TB registrados. En los casos notificados por los establecimientos de atención primaria, se analizaron luego sus características demográficas, el aspecto clínico y los desenlaces del tratamiento antituberculoso.Método: Fue este un análisis retrospectivo de cohortes de datos del programa del 2012 y el 2013.Resultados: De los 2153 pacientes registrados con diagnóstico de TB en todos los establecimientos de salud, 969 eran migrantes (45%); 454 se registraron en centros de atención primaria. De estos últimos, el 27% correspondió a migrantes transfronterizos, el 50% presentaba TB contagiosa y el 12% padecía TB farmacorresistente. La tasa de éxito terapéutico en los casos nuevos de tuberculosis fue 74% y en los casos de retratamiento fue 44% (meta de la Organización Mundial de la Salud ⩾85%). El índice de fracaso terapéutico de los casos nuevos fue 8% y el de los casos en retratamiento fue 25%. En 26 personas que iniciaron el tratamiento antituberculoso de primera línea el tratamiento fracasó debido a la TB multirresistente. También fracasó el régimen de retratamiento en ocho de las 32 personas que lo habían recibido (25%). Las pérdidas durante el seguimiento fueron 10% en los casos nuevos y 19% en los casos de retratamiento.Conclusión: Los migrantes representan cerca de la mitad de todos los casos de TB, la farmacorresistencia es frecuente y alcanzan desenlaces terapéuticos desfavorables. Es urgente promover la colaboración entre los países, dar prioridad a los medios diagnósticos rápidos de la TB (Xpert® MTB/RIF) y encontrar formas innovadoras de progreso que favorezcan mejores desenlaces terapéuticos.

Quantum suppression of antihydrogen formation in positronium-antiproton scattering.

The interaction of antiprotons with low-energy positronium atoms is a fundamental three-body problem whose significance is its utility for formation of antihydrogen. Particular importance resides in understanding processes involving excited positronium states. Until recently such studies were performed using classical techniques. However, they become inapplicable in the low-energy domain. Here we report the results of comprehensive quantum calculations, which include initial excited positronium states with principal quantum numbers up to n i = 5. Contrary to expectation from earlier work, there are only muted increases in the cross-sections for antihydrogen formation for n i > 3. We interpret this in terms of quantum suppression of the reaction at higher angular momenta. Furthermore, the cross-sections for elastic scattering are around two orders of magnitude higher, which we attribute to the degeneracy of the positronium states. We outline some experimental consequences of our results.

Maximum entropy modeling risk of anthrax in the Republic of Kazakhstan.

The objective of this study was to zone the territory of the Republic of Kazakhstan (RK) into risk categories according to the probability of anthrax emergence in farm animals as stipulated by the re-activation of preserved natural foci. We used historical data on anthrax morbidity in farm animals during the period 1933 - 2014, collected by the veterinary service of the RK. The database covers the entire territory of the RK and contains 4058 anthrax outbreaks tied to 1798 unique locations. Considering the strongly pronounced natural focality of anthrax, we employed environmental niche modeling (Maxent) to reveal patterns in the outbreaks' linkages to specific combinations of environmental factors. The set of bioclimatic factors BIOCLIM, derived from remote sensing data, the altitude above sea level, the land cover type, the maximum green vegetation fraction (MGVF) and the soil type were examined as explanatory variables. The model demonstrated good predictive ability, while the MGVF, the bioclimatic variables reflecting precipitation level and humidity, and the soil type were found to contribute most significantly to the model. A continuous probability surface was obtained that reflects the suitability of the study area for the emergence of anthrax outbreaks. The surface was turned into a categorical risk map by averaging the probabilities within the administrative divisions at the 2nd level and putting them into four categories of risk, namely: low, medium, high and very high risk zones, where very high risk refers to more than 50% suitability to the disease re-emergence and low risk refers to less than 10% suitability. The map indicated increased risk of anthrax re-emergence in the districts along the northern, eastern and south-eastern borders of the country. It was recommended that the national veterinary service uses the risk map for the development of contra-epizootic measures aimed at the prevention of anthrax re-emergence in historically affected regions of the RK. The map can also be considered when developing large-scale construction projects in the areas comprising preserved soil foci of anthrax.

Diagnostic accuracy of the Xpert® MTB/RIF cycle threshold level to predict smear positivity: a meta-analysis.

SETTING: Xpert® MTB/RIF is the most widely used molecular assay for rapid diagnosis of tuberculosis (TB). The number of polymerase chain reaction cycles after which detectable product is generated (cycle threshold value, CT) correlates with the bacillary burden.OBJECTIVE To investigate the association between Xpert CT values and smear status through a systematic review and individual-level data meta-analysis. DESIGN: Studies on the association between CT values and smear status were included in a descriptive systematic review. Authors of studies including smear, culture and Xpert results were asked for individual-level data, and receiver operating characteristic curves were calculated. RESULTS: Of 918 citations, 10 were included in the descriptive systematic review. Fifteen data sets from studies potentially relevant for individual-level data meta-analysis provided individual-level data (7511 samples from 4447 patients); 1212 patients had positive Xpert results for at least one respiratory sample (1859 samples overall). ROC analysis revealed an area under the curve (AUC) of 0.85 (95%CI 0.82-0.87). Cut-off CT values of 27.7 and 31.8 yielded sensitivities of 85% (95%CI 83-87) and 95% (95%CI 94-96) and specificities of 67% (95%CI 66-77) and 35% (95%CI 30-41) for smear-positive samples. CONCLUSION: Xpert CT values and smear status were strongly associated. However, diagnostic accuracy at set cut-off CT values of 27.7 or 31.8 would not replace smear microscopy. How CT values compare with smear microscopy in predicting infectiousness remains to be seen.

Antiproton stopping power data for radiation therapy simulations.

Stopping powers of H, He, H2, and H2O targets for antiprotons have been calculated using a convergent close-coupling method. For He and H2 targets electron-electron correlations are fully accounted for using a multiconfiguration approximation. Two-electron processes are included using an independent-event model. The water molecule is described using a neon-like structure model with a pseudo-spherical potential. Results are tabulated for the purpose of Monte Carlo simulations to model antiproton transport through matter for radiation therapy.

[Alterations of serum neurospecific proteins concentrations in patients with metabolic syndrome]. / Izmenenie kontsentratsii syvorotochnykh neirospetsificheskikh belkov u patsientov s metabolicheskim sindromom.

AIM: Metabolic syndrome (MS) - is a complex of metabolic, hormonal and clinical disorders which are risk factors for cardiovascular disease. The study aimed to determine the markers NSE, GFAP, MMP-9 in patients with MS and to assess their prognostic value in the development of acute stroke. MATERIAL AND METHODS: A cross-sectional analytical studyincluded 157 patients stratified into 4groups (control group, patients with MS, patients with ischemic stroke and patients with ischemic stroke and MS). Laboratory examinations included measurements of MS parameters(total cholesterol, blood glucose, cholesterol, HDL and LDL, triglycerides) and concentrations of neurospecific markers NSE, GFAP and MMP-9 by ELISA. RESULTS AND CONCLUSION: A relationship between MS and increased concentration of NSE is found. This indicates the presence of neuronal brain injury in patients with metabolic syndrome. There were no changesin the concentrations of GFAP and MMP-9 in patients with MS.

Antihydrogen Formation via Antiproton Scattering with Excited Positronium.

Utilizing the two-center convergent close-coupling method, we find a several order of magnitude enhancement in the formation of antihydrogen via antiproton scattering with positronium in an excited state over the ground state. The effect is greatest at the lowest energies considered, which encompass those achievable in experiment. This suggests a practical approach to creating neutral antimatter for testing its interaction with gravity and for spectroscopic measurements.

Target structure-induced suppression of the ionization cross section for low-energy antiproton-molecular hydrogen collisions: theoretical confirmation.

Theoretical confirmation of the experimentally observed phenomenon [Knudsen et al., Phys. Rev. Lett. 105, 213201 (2010)] of target structure-induced suppression of the ionization cross section for low-energy antiproton-molecular hydrogen collisions is given. To this end a novel time-dependent convergent close-coupling approach to the scattering problem that accounts for all possible orientations of the molecular target, has been developed. The approach is applied to study single ionization of molecular hydrogen on the wide energy range from 1 keV to 2 MeV with a particular emphasis on low energies. Results for the orientation-averaged total single ionization cross section are compared with available experimental data and good agreement is found at low (<20 keV) and high (>90 keV) energies. A minor discrepancy is found within a small energy gap near the maximum of the cross section.

Coulomb breakup problem.

We formulate scattering theory in the framework of a surface-integral approach utilizing analytically known asymptotic forms of the three-body wave functions. This formulation is valid for both short-range and Coulombic potentials. The post and prior forms of the breakup amplitude are derived without any reference to renormalization procedures.

Near-threshold positron-impact ionization of atomic hydrogen.

We consider the positron-impact ionization (breakup) of atomic hydrogen utilizing the full and S-wave model calculations, concentrating on the near-threshold energy region. Unlike the corresponding electron-impact case, the S-wave model does support the Wannier-like threshold law predicted by Ihra et al. [Phys. Rev. Lett. 78, 4027 (1997)10.1103/PhysRevLett.78.4027]. It is found that convergent S-wave model cross sections are obtained only if complete expansions are utilized on both the atomic and the positronium centers. Furthermore, we suggest that, in the model and full calculations, the separate contributions to the breakup cross section from both centers become equal at threshold.

Integral representation for the electron-atom ionization amplitude which is free of ambiguity and divergence problems.

It is shown that existing problems with the formal theory of ionization can be effectively resolved. An integral representation for the ionization amplitude free of ambiguity and divergence problems is given. Moreover, the ionization amplitude in the new formulation is shown directly to have an ideal form for practical calculations.

Diagnostic features of Alzheimer's disease extracted from PET sinograms.

Texture analysis of positron emission tomography (PET) images of the brain is a very difficult task, due to the poor signal to noise ratio. As a consequence, very few techniques can be implemented successfully. We use a new global analysis technique known as the Trace transform triple features. This technique can be applied directly to the raw sinograms to distinguish patients with Alzheimer's disease (AD) from normal volunteers. FDG-PET images of 18 AD and 10 normal controls obtained from the same CTI ECAT-953 scanner were used in this study. The Trace transform triple feature technique was used to extract features that were invariant to scaling, translation and rotation, referred to as invariant features, as well as features that were sensitive to rotation but invariant to scaling and translation, referred to as sensitive features in this study. The features were used to classify the groups using discriminant function analysis. Cross-validation tests using stepwise discriminant function analysis showed that combining both sensitive and invariant features produced the best results, when compared with the clinical diagnosis. Selecting the five best features produces an overall accuracy of 93% with sensitivity of 94% and specificity of 90%. This is comparable with the classification accuracy achieved by Kippenhan et al (1992), using regional metabolic activity.

[Work capacity of patients with tuberculosis of a solitary kidney]. / Trudosposobnost' ftiziologicheskikh bol'nykh s edinstvennoi pochkoi.

The material for this report is based on the examination data produced from 105 patients with a single kidney who were operated on for contralateral kidney tuberculosis. The conducted clinical trial confirms the approach that the correct solution of the problems in medical labor examination depends on the nature of a pathologic process in the single kidney, clinical course of the disease and period of a pathologic process, degree of a chronic renal failure, arterial hypertension and severity of the pain syndrome. The role of social factors and the rehabilitation aspects of this type of the patients are considered.

[Ultrasonic scanning in chronic renal insufficiency]. / Ul'trazvukovoe skanirovanie pri khronicheskoi pochechnoi nedostatochnosti.

A total of 315 patients with chronic renal insufficiency (CRI) were investigated in order to study the potentialities of ultrasound scanning in early diagnosis of obstructive nephropathy. The susceptibility of the test was 96%, specificity--94%. Due to its simplicity and noninvasiveness it can be recommended as a method of screening in renal obstruction irrespective of renal function. It provides an opportunity to rapidly identify groups of patients who need urgent surgical aid to restore urine passage or conservative therapy. In the absence of ultrasound signs of obstructive diseases further x-ray examination is inappropriate. The use of ultrasound scanning as the first diagnostic procedure simplifies and facilitates the examination of CRI patients, preventing undesirable complications, associated with radiocontrast methods of kidney visualization.