140 research outputs found
Vortex core size in interacting cylindrical nanodot arrays
The effect of dipolar interactions among cylindrical nanodots, with a
vortex-core magnetic configuration, is analyzed by means of analytical
calculations. The cylinders are placed in a N x N square array in two
configurations - core oriented parallel to each other and with antiparallel
alignment between nearest neighbors. Results comprise the variation in the core
radius with the number of interacting dots, the distance between them and dot
height. The dipolar interdot coupling leads to a decrease (increase) of the
core radius for parallel (antiparallel) arrays
Analysis of X-ray whispering gallery waves propagating along liquid meniscuses
X-ray diffraction and fluorescence of whispering galleries (WGs) which propagate along meniscuses of deionized water or silicahydrosols enriched by CsOH have been analyzed for the first time. The measurements have been performed using the diffractometer with a moving tube-detector system. The X-ray beam rotation angle reached a maximum value of 4° on a silica hydrosol sample. The WG mode propagating near the surface of a concave meniscus as well as the fluorescence intensity have been found from a solution of the respective Helmholtz equations. For analysis of intensities of the X-ray scattering and fluorescence we have used a two-layer model of the liquid with the upper non-uniform corrugated layer in which the concentration of levitating Cs+ ions near the surface has a maximum derived from the experiment in the hydrosol depth of ~ 15 nm for SiO2particle sizes of ~ 5...7 nm. In order to determine the fluorescence intensity we have used the approach based on a method of fundamental parameters using the reciprocity theorem
Studying microstructure and phase composition of a new complex calcium containing alloy
In the given article there are presented the results of studying the microstructure and phase structure of a complex alloy of alumosilicon with calcium. It is established that in the studied CAMS alloy active elements are present at a type of difficult intermetallid that positively influences quality of both ordinary, and qualitative brands of steel
Condensation of Silica Nanoparticles on a Phospholipid Membrane
The structure of the transient layer at the interface between air and the
aqueous solution of silica nanoparticles with the size distribution of
particles that has been determined from small-angle scattering has been studied
by the X-ray reflectometry method. The reconstructed depth profile of the
polarizability of the substance indicates the presence of a structure
consisting of several layers of nanoparticles with the thickness that is more
than twice as large as the thickness of the previously described structure. The
adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the
hydrosol/air interface is accompanied by the condensation of anion silica
nanoparticles at the interface. This phenomenon can be qualitatively explained
by the formation of the positive surface potential due to the penetration and
accumulation of Na+ cations in the phospholipid membrane.Comment: 7 pages, 5 figure
11C-Choline Pet/Ct in the Detection of Prostate Cancer Relapse in Patients After Radical Treatment With Psa Level < 10 Ng/Ml
Purpose: To evaluate the usefulness of 11C-Choline PET/CT in the detection of recurrent prostate cancer (PCa) in patients with biochemical relapse after radical treatment. Materials and methods: This retrospective study included 217 PCa patients who underwent 11C-Choline PET/CT in the Department of Nuclear Medicine of Bakoulev Scientific Centre. All patients had biochemical relapse 3±2 years after radical treatment for locally advanced PCa (T1–3 N0–1 M0): radical prostatectomy (n = 159) and radiation therapy (n = 58). The mean PSA value in the group was 2.1±2.5 (0.2–9.7) ng/ml, median – 1.9 ng/ml. Imaging was performed on PET/CT scanner (Biograph-64, Siemens) 10 min after injection of 11C-Choline (400–550 Mbq).
Results: Overall, according to 11C-Choline PET/CT results PCa relapse was detected in 56% (121/217) of cases: in 50% (80/159) after radical prostatectomy and in 71% (41/58) after radiation therapy. The mean PSA value in PET-positive cases was 3.1±2.2 (0.2–9.7) ng/ml, while in PETnegative cases – 1.8±1.7 (0.2–4.6) ng/ml. The majority – 68% (65/96) patients with PET-negative scan had low PSA levels (< 2 ng/ml). PET/CT results were positive in 43% (50/115) patients with PSA of < 2 ng/ml, in 63% (45/72) with PSA of 2 to 5 ng/ml, and in 87% (26/30) with PSA of > 5 ng/ml. Local relapse was detected in 51% (62/121) patients, distant metastases – in 28% (34/121) of cases, both local and distant metastases – in 21% (25/121) of cases. Lymph node metastases were detected in 38% (86/217) of all patients included in the analysis, of which 28% (24/86) had lesions in lymph node of normal size (median 7 mm). Of all PET-positive patients bone metastases were detected in 33% (40/121), of which 60% (24/40) had isolated skeletal involvement. Importantly, that 27% (11/40) of PETpositive patients with bone metastases had no structural abnormalities on CT images (CT-negative cases), corresponding to isolated involvement of bone marrow. And half of these CT-negative patients (5/11) had single lesions. The mean PSA value in patients with bone metastases was 5.0±3.7 (0.4–9.1) ng/ml, median – 3.8 ng/ml. According to 11C-Choline PET/CT results oligometastatic PCa recurrence was revealed in 38% (82/217) of all patients, of which 62% (51/82) had local relapse only. Distant oligometastatic lesions were detected in 38% (31/82), of which 13% (4/31) were presented by normal-size lymph nodes and 19% (6/31) – by early bone marrow metastases. 48% (58/121) of PET-positive results were confirmed by data of repeated PET/CT examinations. Conclusion: 11C-Choline PET/CT has been shown to be a single noninvasive accurate technique for detection of recurrent PCa in patients with rising PSA after radical treatment, which allows to differentiate patients with local and distant metastases in one study, as well as identify oligometastatic process, and therefore was useful in determining the further personalized therapeutic approach.
Keywords: prostate cancer, PET/CT, 11C-Choline, biochemical recurrence, PSA
LOCAL RECURRENCE OF TUBULOCYSTIC CARCINOMA 4 YEARS AFTER RENAL RESECTION (A CLINICAL OBSERVATION)
The paper describes a clinical case of a local recurrence of tubulocystic carcinoma (TCC) in a 46-year-old man, a relatively good course (the relapse occurred after 4 years), who has been successfully operated on and is being followed up. This disease is a rare renal malignancy and, until recently, it has been referred to as collecting tubular carcinoma. However, this disease has come to be regarded as an independent nosological entity, by taking into account its certain morphological, immunohistohemical, and cytogenetic characteristics, as well as the nature of its course. About 80 TCC cases have been described to date. Further study of this disease and other rare renal malignancies will allow the more accurate elaboration of management tactics for such patients in terms of certain prognostic factors, which calls for a larger number of cases of this disease
Reformation of system of emergency medical help for injured persons on early hospital stage
Objective. To determine the key trend of reformation of the system of the emergent medical help to the injured persons on early hospital stage.
Маterials and methods. The systemic analysis, including a bibliographical one, semantic and economic methods of investigation, as well as organization of the medical help delivery to the injured persons in USA.
Results. The system of the emergency medical help delivery to the injured persons is based on the trauma centers net. Treatment of the injured persons, suffering severe trauma in the centers of trauma is by 40 - 60% more effective and by 50 - 60% more cost-effective, than in surgical/traumatological departments of the national Medical Health Service. The system of Emergency Medical Help for injured persons on early hospital stage in Ukraine demands organization of no less than 30 Centers of Trauma of the level І on the base of the University Regional Hospitals and in the cities with more than 1 million of inhabitants; approximately 200 the Level II Centers of Trauma on the base of multidisciplinary hospitals for intensive treatment of the second level and 300 the Level III trauma centers on the base of multidisciplinary hospitals for intensive treatment of the first level. Complete need for Ukraine constitutes 530 Centers of Trauma.
Conclusion. The system for the Emergency Medical Help Delivery to the injured persons must be based on the net of the Trauma Centers of a certain level. The trauma centers organization needs some preliminary work to do: to study the traumatism indices, analysis of the regional need in medical help delivery and depicting of the National Trauma Registry. Trauma Centers in Ukraine is expedient to create on the base of the university regional hospitals, multidisciplinary hospitals of intensive therapy and hospitals of urgent medical help. Possibility of inclusion to the medical help delivery of such specialists, as a surgeon, anesthesiologist, traumatologist and neurosurgeon, constitutes an obligatory element of the trauma center organization. Financial support for the medical help delivery to the injured persons, suffering severe combined trauma, demands additional input of the nonbudget resources
Fabrication and thermal stability of arrays of Fe nanodots
This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.We have fabricated arrays of 60-nm-size magnetic Fe nanodots over a 1-cm2 -size area using nanoporous alumina membranes as shadow masks. The size and size distribution of the nanodots correlate very well with that of the membrane pores. By placing an antiferromagnetic FeF2 layer underneath the Fe nanodots, an exchange anisotropy can be introduced into the Fe/FeF2 system. We have observed an increase in the magnetic hysteresis loop squareness in biased nanodots, suggesting that exchange bias may be used as a tunable source of anisotropy to stabilize the magnetization in such nanodots
Experience of interinstitutional interaction while delivering of surgical aid in the disasters environment
Objective. Investigation of interinstitutional interaction environment while delivering of surgical aid in conditions of disaster, the need in certain kinds of surgical operations estimation of efficacy of civil-military interaction in sector of the antiterrorist operation conduction.
Materials and methods. The results of surgical treatment of 290 wounded persons and patients in medical company of Military Forces of Ukraine, which have functioned in a health care facility on Lugansk direction in summer 2015 yr, were presented. The efficacy of a civil-military interaction was estimated. Methods of the system analysis, clinical, medic-statistic and economic were there applied.
Results. Introduction of system of the civil-military interaction while conduction of to all wounded persons and patients, to enhance the resource support of a health care facility by 39.7%.
Conclusion.Joint usage of present civil and military resources for delivery of medical help to patients and wounded persons impacts on the treatment results positively
Effect of surface interactions on the hysteresis of capillary condensation in nanopores
Gas adsorption and liquid desorption of a number of organic vapors in anodized nanoporous alumina, with controlled geometry (cylindrical pore diameters from 10 to 60 nm), are studied using optical interferometry. The narrow-diameter distribution of disconnected pores allows checking the validity of the (long-predicted but not experimentally verified) Kelvin equation without any adjustable parameters, modeling or other assumptions. Evaporation occurs at liquid-vapor equilibrium according to this equation, whereas condensation occurs from metastable states of the vapor phase by nucleation, enhanced by surface defects inside the nanopores. This produces hysteresis, in qualitative agreement with theoretical models and simulations that use Van der Waals interactions between the fluid and the pore surface. The reproducibility of the hysteresis depends on the strength of these interactions, which play an important role in the dynamics of capillary condensation
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