Penetrators (penetrating sondes) and new possibilities for study of the planets

The fields of possible use of penetrators in space research are considered. A survey of the condition of development and plans for use of penetrators abroad is presented and an analysis is given of the significance of scientific problems when probing planets

Ion-cyclotron turbulence and diagonal double layers in a magnetospheric plasma

A survey of current concepts regarding electrostatic ion-cyclotron turbulence (theory and experiment), and regarding inclined double potential layers in the magnetospheric plasma is presented. Anomalous resistance governed by electrostatic ion-cyclotron turbulence, and one-dimensional and two-dimensional models of double electrostatic layers in the magnetospheric plasma are examined

Chatbot Design and Implementation: Towards an Operational Model for Chatbots

The recent past has witnessed a growing interest in technologies for creating chatbots. Advances in Large Language Models for natural language processing are underpinning rapid progress in chatbot development, and experts predict revolutionary changes in the labour market as many manual tasks are replaced by virtual assistants in a range of business functions. As the new technology becomes more accessible and advanced, more companies are exploring the possibilities of implementing virtual assistants to automate routine tasks and improve service. This article reports on qualitative inductive research undertaken within a chatbot development team operating in a major international enterprise. The findings identify critical success factors for chatbot projects, and a model is developed and validated to support the planning and implementation of chatbot projects. The presented model can serve as an exemplary guide for researchers and practitioners working in this field. It is flexible and applicable in a wide range of business contexts, linking strategic business goals with execution steps. It is particularly applicable for teams with no experience in chatbot implementation, reducing uncertainty and managing decisions and risks throughout the project lifecycle, thereby increasing the likelihood of project success

The use of (99m}Tc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]O[3], and Group II patients (n=30) received 99mTc-labeled phytate colloid. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. 18 hours after {99m}Tc-Al[2]O[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II SLNs were detected in 27 patients. 18 hours after injection of the phytate colloid the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. The new radiopharmaceutical based on the {99m}Tc-Al[2]O[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. The sensitivity and specificity of {99m}Tc-Al[2]O[3] were 100% for both SPECT and intraoperative gamma probe identification

The use of (99m}Tc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]O[3], and Group II patients (n=30) received 99mTc-labeled phytate colloid. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. 18 hours after {99m}Tc-Al[2]O[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II SLNs were detected in 27 patients. 18 hours after injection of the phytate colloid the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. The new radiopharmaceutical based on the {99m}Tc-Al[2]O[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. The sensitivity and specificity of {99m}Tc-Al[2]O[3] were 100% for both SPECT and intraoperative gamma probe identification

Experimental study of {99m}Tc-aluminum oxide use for sentinel lymph nodes detection

The purpose of the study was a comparative research in the possibility of using the radiopharmaceuticals {99m}Tc-Al[2]O[3] and {99m}Tc-Nanocis for visualizing sentinel lymph nodes. The measurement of the sizes of {99m}Tc-Al[2]O[3] and {99m}Tc-Nanocis colloidal particles was performed in seven series of radiopharmaceuticals. The pharmacokinetics of {99m}Tc-Al[2]O[3] and {99m}Tc-Nanocis was researched on 50 white male rats. The possibility of the use of {99m}Tc-Al[2]O[3] and {99m}Tc-Nanocis for lymphoscintigraphy was studied in the experiments on 12 white male rats. The average dynamic diameter of the sol particle was 52-77 nm for {99m}Tc-Al[2]O[3] and 16.7-24.5 nm for {99m}Tc-Nanocis. Radiopharmaceuticals accumulated in the inguinal lymph node in 1 hour after administration; the average uptake of {99}mTc-Al[2]O[3] was 8.6% in it, and the accumulation of {99m}Tc-Nanocis was significantly lower-1.8% (p < 0.05). In all study points the average uptake of {99m}Tc-Al[2]O[3] in the lymph node was significantly higher than {99m}Tc-Nanocis accumulation. The results of dynamic scintigraphic studies in rats showed that {99m}Tc-Al[2]O[3] and {99m}Tc-Nanocis actively accumulated into the lymphatic system. By using {99m}Tc-Al[2]O[3] inguinal lymph node was determined in 5 minutes after injection and clearly visualized in all the animals in the 15th minute, when the accumulation became more than 1% of the administered dose. Further observation indicated that the {99m}Tc-Al[2]O[3] accumulation reached a plateau in a lymph node (average 10.5%) during 2-hour study and then its accumulation remained practically at the same level, slightly increasing to 12% in 24 hours. In case of {99m}Tc-Nanocis inguinal lymph node was visualized in all animals for 15 min when it was accumulated on the average 1.03% of the administered dose. Plateau of {99m}Tc-Nanocis accumulation in the lymph node (average 2.05%) occurred after 2 hours of the study and remained almost on the same level (in average 2.3%) for 24 hours. Thus, the experimental study of a new domestic radiopharmaceutical showed that the {99m}Tc-Al[2]O[3]accumulates actively in the lymph nodes several times as compared to the imported analogue and its practical application will facilitate intraoperative identification of sentinel lymph nodes

Numerical investigation of meniscus deformation and flow in an isothermal liquid bridge subject to high-frequency vibrations under zero gravity conditions

International audienceThis paper deals with meniscus deformation and flow in an isothermal liquid bridge maintained between two circular rods, when one rod is subject to axial monochromatic vibrations. It concerns a fundamental aspect of the problem of crystal growth from melt by the floating-zone technique which is often considered in weightlessness conditions. In the absence of vibrations the bridge is cylindrical; but due to vibration the mean shape of the meniscus is no more cylindrical and the meniscus oscillates around this mean shape. Two models are developed. First, we take into account the pulsating deformations of the meniscus (free surface), but we assume that the mean shape of meniscus remains cylindrical (i.e., we neglect the influence of vibration on this mean shape). For this simple case, a solution of the problem for the pulsating meniscus deformations and the pulsating velocity field is found in explicit form. For the mean flow, the problem is solved numerically by a finite-difference method. The calculations demonstrate the contribution of two basic mechanisms of mean flow generation due to vibrations, related to the generation of mean vorticity in the viscous boundary layer near the rigid boundaries and surface-wave propagation at a free surface. The intensity of the mean flow induced by surface waves is found to be sharply increasing when the vibration frequency approaches the resonance values that are determined from the explicit form of the solution of pulsation problem. In the second model, we take into account both pulsating and mean deformations of the meniscus. The governing equations for the potential of pulsating velocity and mean velocity, and for the pressure, are solved by using a finite-difference method and a boundary-fitted curvilinear coordinate system fitting the free surface

Development and Study of {99m}Tc-1-Thio-D-glucose for Visualization of Malignant Tumors

The preclinical studies of {99m}Tc-1-Thio-D-glucose, a new tumor-seeking agent based on technetium-99mlabeled glucose derivative, were conducted, and the feasibility of using this radiopharmaceutical for tumor visualization was studied. The preclinical studies were carried out strictly in accordance with the local legislation and were regulated by the generally accepted research standards. {99m}Tc-1-Thio-D-glucose was found to have optimal pharmacokinetic and physico-chemical properties for diagnostic imaging and was proved to belong to the low-toxic substances. The potential utility of {99m}Tc-1-thio-D-glucose for tumor imaging was studied in vitro and in vivo models. The present study demonstrated that {99m}Tc-1-Thio-D-glucose is a prospective radiopharmaceutical for cancer visualization

The first experience of using of {99}mTc-Al[2]O[3] for detection of sentinel lymph nodes in breast cancer

Purpose: to study the feasibility of using the new radiopharmaceutical based on the technetium-99m-labeled gamma-alumina for identification of sentinel lymph nodes (SLNs) in breast cancer patients. Materials and methods. The study included two groups of breast cancer patients who underwent single photon emission computed tomography (SPECT) and intraoperaive gamma probe identification of sentinel lymph nodes (SLNs). To identify SLNs, the day before surgery Group I patients (n=34) were injected with radioactive {99m}Tc-Al[2]0[3], and Group II patients (n=30) received {99m}Tc-labeled phytate colloid. Results. A total of 37 SLNs were detected in Group I patients. The number of identified SLNs per patient ranged from 1 to 2 (the average number of identified SLNs was 1.08). Axillary lymph nodes were the most common site of SLN localization. At 18 hours after {99m}Tc-Al[2]0[3] injection, the percentage of its accumulation in the SLN was 7-11% (of the counts in the injection site) by SPECT and 17-31% by gamma probe detection. In Group II patients, SLNs were detected in 27 patients. At 18 hours after injection of the phytate colloid, the percentage of its accumulation in the SLN was 1.5-2% out of the counts in the injection site by SPECT and 4-7% by gamma probe. Conclusion. The new radiopharmaceutical based on the {99m}Tc -Al[2]0[3] demonstrates high accumulation in SLNs without redistribution through the entire lymphatic basin. Sensitivity and specificity of {99m}Tc -Al[2]0[3] were 100% for both SPECT and intraoperative gamma probe identification

Development new radiopharmaceutical based on 5-thio-d- glucose labeled technetium-99m

The article considers the obtaining and possibility of using 5-thio-D-glucose labeled technetium-99m for the diagnosis of malignant tumors by single photon emission computed tomography. The analysis of the level of international developments of radiopharmaceuticals based on derivatives of glucose has been carried out. Also the article provides information on of using experimental batches of lyophilisate on the basis of 5-thio-D-glucose for preliminary biomedical testing on the mice