A study of the biohydrometallurgical method for extracting gold from flotation tailings

This paper shows the results of the comparative study of efficiency of gold extraction methods from technogenic flotation tails by agitation cyanidation and biooxidation followed by leaching. A representative sample of flotation tails was taken at gold extraction plant of Altyntau Kokshetau LLP. Experimentally, an increase in the efficiency of leaching gold from flotation tails during preliminary bacterial oxidation was found. By biochemical leaching, 72 % was extracted, which is 7 % more than using expensive sodium peroxide and 10 % more than using the traditional method of cyanidation

Electromagnetic nucleon-delta transition in the perturbative chiral quark model

We apply the perturbative chiral quark model to the gamma N -> Delta transition. The four momentum dependence of the respective transverse helicity amplitudes A(1/2) and A(3/2) is determined at one loop in the pseudoscalar Goldstone boson fluctuations. Inclusion of excited states in the quark propagator is shown to result in a reasonable description of the experimental values for the helicity amplitudes at the real photon point.Comment: 25 page

Cubic optical nonlinearity of free electrons in bulk gold

A fast (τresponse &lt;90 fs) free-electron spin-flipping frequency-degenerate nonlinearity with a significant value of |χ(3)xxyy(ω,ω,ω,-ω) χ(3)xyyx(ω,ω,ω,-ω)| ~ 10-8 esu has been observed in bulk gold at 1260 nm by use of a new pump-probe polarization-sensitive technique. <br/

Three-Body approach to the K^- d Scattering Length in Particle Basis

We report on the first calculation of the scattering length A_{K^-d} based on a relativistic three-body approach where the two-body input amplitudes coupled to the Kbar N channels have been obtained with the chiral SU(3) constraint, but with isospin symmetry breaking effects taken into account. Results are compared with a recent calculation applying a similar set of two-body amplitudes,based on the fixed center approximation, considered as a good approximation for a loosely bound target, and for which we find significant deviations from the exact three-body results. Effects of the hyperon-nucleon interaction, and deuteron $D$-wave component are also evaluated.Comment: 5 pages, Submitted to Phys. Rev.

The physical meaning of scattering matrix singularities in coupled-channel formalisms

The physical meaning of bare and dressed scattering matrix singularities has been investigated. Special attention has been attributed to the role of well known invariance of scattering matrix with respect to the field transformation of the effective Lagrangian. Examples of evaluating bare and dressed quantities in various models are given.Comment: 14 pages, Summary of the BRAG2007 worksho

Coastal Dynamics of the Pechora and Kara Seas Under Changing Climatic Conditions and Human Disturbances

Coastal dynamics monitoring on the key areas of oil and gas development at the Barents and Kara Seas has been carried out by Laboratory of Geoecology of the North at the Faculty of Geography (Lomonosov Moscow State University) together with Zubov State Oceanographic Institute (Russian Federal Service for Hydrometeorology and Environmental Monitoring) for more than 30 years. During this period, an up-to-date monitoring technology, which includes direct field observations, remote sensing and numerical methods, has been developed. The results of such investigations are analyzed on the example of the Ural coast of Baydaratskaya Bay, Kara Sea. The dynamics of thermal-abrasion coasts are directly linked with climate and sea ice extent change. A description of how the wind-wave energy flux and the duration of the ice-free period affect the coastal line retreat is provided, along with a method of the wind-wave energy assessment and its results for the Kara Sea region. We have also evaluated the influence of local anthropogenic impacts on the dynamics of the Arctic coasts. As a result, methods of investigations necessary for obtaining the parameters required for the forecast of the retreat of thermoabrasional coasts have been developed

Chiral dynamics in systems with strangeness

In this talk a brief review of several problems involving systems with strangeness is made. In the first place one shows how the Λ(1405), Λ(1670) and Σ(1620) states, for S=−1, and the Ξ(1620) for S=−2 are generated dynamically in the context of unitarized chiral perturbation theory. The results for the K¯N interaction are then used to evaluate the K−d scattering length. Results obtained for the kaon selfenergy in a nuclear medium within this approach, with application to K− atoms, are also mentioned. Finally a few words are said about recent developments in the weak decay of Λ hypernuclei and the puzzle of the Γn/Γp ratio

Staghorn stone and squamous cell carcinoma of the renal pelvis: a clinical case and literature review

Squamous cell carcinoma of the renal pelvis is a rare neoplasm. The incidence does not exceed 1% of all neoplasms of this localization. In the general population, up to 90% of all neoplasms of the renal pelvis are represented by urothelial carcinoma, while from 0.7% to 7.0% of cases are squamous cell carcinoma. Stones of the renal collecting system are found in 14 – 50% of patients with squamous cell carcinoma of the pelvis. As a possible etiopathogenetic mechanism, chronic inflammation on the background of a stone is considered, leading to squamous urothelial metaplasia with subsequent keratinization and malignization. Clinical manifestation of squamous cell carcinoma of the renal pelvis is nonspecific and is primarily associated with manifestations of urolithiasis. Squamous cell carcinoma of the renal pelvis is characterised by high aggressiveness, insensitivity to chemotherapy and radiation therapy, and consequently an unfavourable prognosis. The survival rate of most patients is less than one year from the diagnosis, while the 5-year survival rate does not exceed 10%. We present our own clinical case of a patient with a staghorn stone and squamous cell carcinoma of the renal pelvis

Ультразвуковое исследование с контрастным усилением в дифференциальной диагностике опухолевых образований печени

Purpose: to evaluate the diagnostic value of contrastenhanced ultrasound (CEUS) with SonoVue in differential diagnosis of focal liver lesions (FLL) in a multidisciplinary clinic in Russian Federation.Materials and methods. Bolus intravenous administration of 1.2 ml of SonoVue (Bracco Swiss CA, Switzerland) followed with 5ml saline flush was used for liver CEUS. We utilized the scanners Mindray DC-8 (Mindrаy, China), Logiq S8 (GE, USA), Philips Epiq 7 (Philips, Holland), SonoScape S9 (SonoScape, China), Hitachi Ascendus (Hitachi, Japan) with 3.0–5.0 MHz convex probes in specialized “contrast” mode with low mechanic index (MI 0.08–0.1). The study conferred 73 patients in the age between 18 and 84 years (mean age 49 years) with FLL. CEUS was performed in 22 patients with previously verified diagnosis, while the rest of patients underwent CEUS before the final diagnosis. Contrast-enhanced liver CT was performed in all patients. In 49 (67.12%) of 73 cases, a pathology was performed after a targeted core-needle biopsy or autopsy. Qualitative features of US contrast enhancement of FLL were evaluated.Results. Qualitative aspects of CEUS for differentiation of FLL were defined. The principal sign for diagnosis between benign and malignant masses with CEUS was hypoenhancement of malignant lesions in comparison to surrounding normal parenchyma in portal and late venous phase (p ≤ 0.01). Alternatively, hyper- or isoenhancement throughout late venous phase was characteristic for benign FLL. Diffuse heterogeneous contrast enhancement was indicative of malignant FLL, and homogeneous – for benign. Additional diagnostic feature (p ≤ 0.05) was the type of contrast enhancement in the arterial phase. Heterogeneous diffuse contrast enhancement was observed in malignant FLL, while homogeneous – in benign FLL. Peripheral nodular contrast enhancement with centripetal filling was characteristic for liver hemangioma, centrifugal filling with “spoke-wheel” vascular pattern – for FNH, and peripheral rim-like hyperenhancement with rapid achievement of hypoenhancement at the beginning of the portal phase – for liver metastasis.Conclusion. Complex analysis of qualitative characteristics of CEUS with SonoVue is a promising option for differential diagnosis of FLL (sensitivity 92.85%, specificity 91.3%, diagnostic accuracy 92.15%) and can be utilized in daily practice.Цель исследования: оценить диагностические возможности применения ультразвукового исследования (УЗИ) с использованием контрастного препарата Соновью (Бракко Свисс СА, Швейцария) в дифференциальной диагностике опухолевых образований печени (ООП) в условиях многопрофильной клиники на территории Российской Федерации.Материал и методы. Контраст-усиленное УЗИ (КУУЗИ) печени выполнялось с внутривенным болюсным введением 1,2 мл контрастного препарата Соновью (Бракко Свисс СА, Швейцария) и последующим введением 5 мл 0,9% раствора NaCl. Исследования проводили на сканерах Mindray DC-8 (Mindrаy, Китай), Logiq S8 (GE, США), Philips EPIQ 7 (Philips, Нидерланды), SonoScape S9 (SonoScape, Китай), Hitachi Ascendus (Hitachi, Япония) с использованием конвексных датчиков 3–5 МГц в специализированном режиме “контраст” с низким меха ническим индексом (МИ 0,08–0,1). Исследование проведено 73 пациентам в возрасте 18–84 лет (средний возраст 49 лет) с опухолевыми образованиями печени. Из них 22 пациента до КУУЗИ имели установленный диагноз, у остальных КУУЗИ выполнено до установ ления окончательного диагноза. Во всех случаях пациентам проведена МСКТ печени с внутривенным контрастированием. В 49 (67,12%) из 73 случаев проведено морфологическое исследование после прицельной толсто игольной биопсии или аутопсии. Произведена оценка качественных характеристик контрастного усиления очаговых образований печени.Результаты. Выявлены качественные характеристики КУУЗИ, позволяющие проводить дифференциальную диагностику ООП. Основным дифференциально-диагностическим признаком доброкачественных и злокачественных ООП при КУУЗИ (p ≤ 0,01) является появление гипоусиления ООП в портальную и позднюю венозную фазу в случае злокачественных ООП, и изо- или гиперусиления в портальную и позднюю венозную фазы в случае доброкачественных ООП. Диффузное неоднородное контрастное усиление характерно для злокачественных ООП, а однородное контрастное усиление – для доброкачественных. Дополнительными диффе ренциально-диагностическими признаками (p ≤ 0,05) различных ООП являются тип и характер контрастного усиления в артериальную фазу: неоднородное диффузное контрастное усиление для злокачественных ООП и однородное – для доброкачественных ООП, перифе рическое узловое центростремительное контрастное усиление –достоверный признак гемангиом печени, центробежное усиление с сосудистым рисунком по типу “спиц колеса” – фокально-нодулярной гиперплазии и периферическое кольцевидное гипер-усиление, раннее появление гипоусиления в начале портальной фазы–метастазов печени.Выводы. Комплексная оценка качественных параметров КУУЗИ с ультразвуковым контрастным препаратом Соновью имеет большой диаг ностический потенциал для дифференциальной диаг ностики различных ООП (чувствительность 92,85%, специфичность 91,3%, общая точность 92,15%) и может использоваться в повседневной практике врача ультразвуковой диагностики