7 research outputs found

    Morphological features of autoimmune gastritis

    Get PDF
    Aim of investigation. To estimate presence of classical morphological signs of autoimmune gastritis (AIH) in patients with high titer of antiparietal cells antibodies.Material and methods. Overall 15 patients (3 men and 12 women, 28 to 72 years old) have been included in original study. Clinical symptoms in the study group varied and included both severe В12-deficient anemia and normal levels of pepsinogen I, gastrin-17 and cyanocobalamine. In 4 patients Helicobacter pylori infection has been detected. According to guidelines of the Russian Society of Pathologists in all cases multiple biopsies have been taken at esophagogastroduodenoscopy. Biopsy specimens were processed by the standard technique, sections were stained by hematoxyline and eosine.Results. Classical signs of AIH i.e. atrophy of mucosa of body of the stomach and intestinal metaplasia were not revealed. The signs of feeble inflammation in body of the stomach were found in 6 patients. In 4 cases biopsy specimens had no inflammatory or atrophic changes. Pseudo-hypertrophy of parietal cells was the unique morphological feature found out in these cases. At all patients involvement of antral region of the stomach was marked. Atrophic gastritis with intestinal metaplasia was diagnosed in 4 patients. In 3 cases non-metaplastic variant of patchy atrophic gastritis was present, the rest revealed superficial gastritis with signs of activity in 4 cases. No Н. рylori was found out morphologically.Conclusion. In our investigation in patients with AIG no metaplastic atrophic lesions was found in body of the stomach, while metaplastic atrophy had patchy pattern. The pseudo-hypertrophy of parietal cells as well as dilation of main glands lumen can be the earliest and unique sign found in biopsy specimens. Involvement of antral region was revealed in all patients, in 4 cases it has been related to presence of H. pylori infection at the moment of investigation. Thus, the diagnosis of AIG was based mainly on elevated level antiparietal cells antibodies at blood serum test

    Impact of liquid metal surface on plasma-surface interaction in experiments with lithium and tin capillary porous systems

    Get PDF
    The lithium and tin capillary-porous systems (CPSs) were tested with steady-state plasma in the PLM plasma device which is the divertor simulator with plasma parameters relevant to divertor and SOL plasma of tokamaks. The CPS consists of tin/lithium tile fixed between two molybdenum meshs constructed in the module faced to plasma. Steady-state plasma load of 0.1 - 1 MW/m(2) on the CPS during more than 200 min was achieved in experiments on PLM which is a modeling far scrapeoff- layer and far zone of divertor plasma of a large tokamak. The heating of the CPS was controlled remotely including biasing technique which allows to regulate evaporated metal influx to plasma. After exposure, the materials of the tin and lithium CPSs were inspected and analyzed with optic and scanning electron micriscopy. Experiments have demonstrated sustainability of the tin and lithium CPSs to the high heat steady state plasma load expected in a large scale tokamak. The effect of evaporated lithium and tin on the plasma transport/radiation was studied with spectroscopy to evaluate changes of plasma properties and plasma-surface interaction

    Spectral Characteristics of Polarization Radiation in the Water Window Range

    No full text
    The high-intensity and monochromatic radiation sources in the water window spectral range are desirable for many applications. One of the potential candidates of soft X-ray sources is polarization radiation produced by a charged particle passing through a thin foil. In the soft X-ray range near the absorption edges of a target material, the real part of dielectric permittivity can exceed unity, and the Tamm–Frank criterion is fulfilled. Thus, two types of radiation are produced: transition and Cherenkov radiation. In this report, we theoretically investigated the spectral characteristics of radiation produced in both cases when the Tamm–Frank criterion is met or not met. We showed the dependences of the spectrum as a function of thickness and the incidence angle. To describe the properties of polarization radiation and the complex dielectric permittivity, the polarization current approach and Henke’s model were used, respectively

    Current injected detectors (CID): a new approach for detector operation in very high radiation environment

    No full text
    For the upcoming Super LHC (SLHC) experiments on the LHC upgrade, Si detectors will still be considered as the main detectors for inner tracker. However, the radiation level in SLHC will be up to 10 times more than that in LHC due to the increase of luminosity from 10/sup 34based on the current injection in the detector bulk is considered. It is shown that the symmetric p/sup positive n-p/sup positive structures as well as regular p/sup positive n-n/sup positive silicon detectors after irradiation by neutrons up to 5centerdot10/sup 14/ cm /sup -2/ can operate at self-stabilized current injection (SSCI) or space charge limited current (SCLC) mode. This provides a stable electric field profile at any higher fluences with the electric field distributed in the entire detector thickness (full depletion mode). In this study operation of heavily irradiated Si detectors in the SSCI mode is confirmed by the measurements of I-V characteristics, which show the region with square I on V dependence and then the sharp current rise at a threshold voltage. It is shown that the threshold voltage rises linearly with the irradiation fluence that allows biasing the detectors by higher voltage with the fluence increase. This is obviously helpful for reduction of the collection time and consequently the related charge loss due to trapping

    NWChem: Past, present, and future

    Get PDF
    Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook

    NWChem

    Get PDF
    Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.Peer reviewe
    corecore