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1.
Opt Lett ; 49(11): 3042-3045, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38824323

RESUMEN

It is well known that the beam splitter is an integral part of many classical and quantum devices. The use of beam splitters in quantum technologies is currently particularly relevant. The emergence of new types of beam splitters provides new statistical characteristics of the separated photon beam and their control and new possibilities for use in various devices. This Letter presents a new, to the best of our knowledge, type of beam splitter based on free charged particles. This type of beam splitter has all the properties of a linear beam splitter with its reflection coefficient R, transmission coefficient T, and phase shift ϕ, which are presented in a simple analytical form. This type of beam splitter has interesting application prospects.

2.
Georgian Med News ; (347): 117-121, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38609126

RESUMEN

An elderly person is the subject of changes and development of the basic conditions of his life. Older patients may experience manifestations of social aging, in which some new areas of social reality remain unexplored for them. This article analyzes dispositional optimism and locus of control, as two personal characteristics closely related to the social and psychological aspects. The aim of the study was to examine the relationship between dispositional optimism and locus of control in young and old people. During the study, 115 elderly respondents from the Gerontological Center were surveyed. The average age was 70 [52-74]. A survey of 120 students of the Krasnoyarsk State Medical University of the first, second, third and fourth years, whose average age was 20 [19-25] was conducted. The majority of elderly patients were classified as having an external locus of control (54%), while 46% had an internal locus of control. Regarding optimism, 20% of older people were optimists, 73% were pessimists, and 7% of respondents had a combination of both optimism and pessimism. The majority of young respondents also fell into the category with an external locus of control (70%), while 30% had an internal locus of control. 73% of young people were optimists, 19% were pessimists, and 8% of respondents had a combination of both optimism and pessimism. In older people, there is an inverse relationship between the indicators - the level of internality is inversely proportional to the level of optimism, which is explained by the expectation that bad events will happen more often in the future than good ones. Accordingly, it is necessary to introduce practical recommendations.


Asunto(s)
Geriatría , Motivación , Anciano , Humanos , Adolescente , Adulto Joven , Adulto , Envejecimiento , Factores de Riesgo , Optimismo
3.
Phys Chem Chem Phys ; 25(2): 1310-1330, 2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36533685

RESUMEN

The results of a rigorous study of the two first pure rotational transitions of CO perturbed by Ar are presented. The experimental part is based on the use of three different spectrometers covering together the pressure range from 0.02 up to 1500 torr. The measurement results of collisional line shape parameters are supported by fully ab initio calculations, which are in remarkable agreement with retrieved data. A sub-percent uncertainty of line intensity measurements is achieved and the first firm evidence that the resonance spectrum of CO is observed on the continual pedestal is given. We analyze the results of our ab initio calculations on the basis of early analytical theories and demonstrate a good general applicability of the latter to the CO-Ar collisional system.

4.
Mol Biol (Mosk) ; 55(1): 164-176, 2021.
Artículo en Ruso | MEDLINE | ID: mdl-33566035

RESUMEN

Resistance developed to the majority of drugs used to treat infectious diseases warrants the design of new compounds effective against drug-resistant strains of pathogens. Recently, several groups of modified nucleosides have been synthesized and showed significant antibacterial activity in vitro, but their further studies were difficult to undertake because of their low solubility in aqueous solutions. Nevertheless, new compounds, well soluble in water-organic solutions, were synthesized and found to be more effective in inhibiting the growth of Gram-positive bacteria and mycobacteria. The water-soluble forms of modified nucleosides under study were assumed to be their depot forms. To check the assumption, the compounds were tested for hydrolysis in various media and their molecular docking was performed into the active center of the putative target, Mycobacterium tuberculosis flavin-dependent thymidylate synthase ThyX. Computer modelling showed that the water-soluble analogs do not act as ThyX inhibitors, supporting the assumption of their depot nature. The compounds were resistant to chemical hydrolysis but were hydrolyzed when incubated with porcine liver carboxylesterase, human serum, or Staphylococcus aureus 209P. The results demonstrate that the compounds are most likely depot forms of modified nucleosides.


Asunto(s)
Mycobacterium tuberculosis , Nucleósidos , Animales , Antibacterianos/farmacología , Glicoles , Humanos , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Nucleósidos/farmacología , Fosfatos , Porcinos
5.
Khirurgiia (Mosk) ; (4): 34-38, 2021.
Artículo en Ruso | MEDLINE | ID: mdl-33759466

RESUMEN

OBJECTIVE: To reduce the incidence of complications in acute destructive pancreatitis via stenting of the main pancreatic duct in complex treatment of these patients. MATERIAL AND METHODS: There were 182 patients aged 31-76 (mean 42.8±11) years with acute destructive pancreatitis. All patients admitted to the 1st and the 2nd surgical departments of the Kazan City Hospital No. 7 for the period from 2017 to 2019. There were 78 (43%) men and 104 (57%) women. Two groups of patients were distinguished in order to compare the effectiveness of stenting of the main pancreatic duct in acute pancreatitis: main group (34 patients including 14 men and 20 women) - stenting of the main pancreatic duct, control group (50 patients including 20 men and 30 women) without stenting. RESULTS: Complex diagnosis and treatment of acute pancreatitis in intensive care unit with percutaneous drainage of fluid accumulations under ultrasound control and stenting of the main pancreatic duct reduce postoperative mortality from 16% in the control group (n=50) to 9.2% in the main group (n=34). Moreover, this approach is valuable to localize the foci of pancreatic necrosis in 79% of cases. the An efficiency of endoscopic decompression of the main pancreatic duct was 42% in patients with alcoholic pancreatitis. CONCLUSION: Endoscopic stenting of the main pancreatic duct is effective for pathogenetic treatment of patients with biliary pancreatitis, aimed at reducing intraductal hypertension in the early stages of disease.


Asunto(s)
Conductos Pancreáticos/cirugía , Pancreatitis , Adulto , Anciano , Descompresión Quirúrgica , Drenaje , Endoscopía del Sistema Digestivo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conductos Pancreáticos/diagnóstico por imagen , Pancreatitis/diagnóstico por imagen , Pancreatitis/etiología , Pancreatitis/mortalidad , Pancreatitis/cirugía , Implantación de Prótesis , Stents , Resultado del Tratamiento , Ultrasonografía Intervencional
6.
Bull Exp Biol Med ; 166(1): 155-162, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30417290

RESUMEN

Human umbilical cord represents a source of multipotent stromal cells of a supreme therapeutic potential. The cells can be isolated from either fresh or cryopreserved umbilical cord tissues. DMSO is a cryoprotectant most commonly used for preservation of umbilical cord tissues; however, cyto- and genotoxicity of this compound is evident and well documented. In the present study we performed successful cryopreservation of the umbilical cord tissue using other cryoprotectants: propylene glycol, ethylene glycol, and glycerol. Of these, 1.5 M ethylene glycol and 20% glycerol turned out to be the best in terms of the preservation of living cells within the frozen tissue, early onset of migration of these cells out of the thawed explants, and overall efficacy of multipotent stromal cell isolation. Cryobanking of tissues can improve availability of multiple cell products for medical purposes and promote the development of personalized medicine.


Asunto(s)
Criopreservación/métodos , Crioprotectores/química , Crioprotectores/farmacología , Dimetilsulfóxido/química , Glicol de Etileno/farmacología , Glicerol/farmacología , Humanos , Células Madre Multipotentes/efectos de los fármacos , Propilenglicol/farmacología , Cordón Umbilical/citología
7.
Angiol Sosud Khir ; 24(3): 116-121, 2018.
Artículo en Ruso | MEDLINE | ID: mdl-30321155

RESUMEN

The authors retrospectively analysed medical case histories of 287 patients subjected to femoral amputations over the period from January 1, 1998 to December 31, 2013. The studied parameters were as follows: the frequency of and risk factors for femoral stump ischaemia, as well as the effect on patients' survival after femoral amputation. Amongst 156 patients having endured transfemoral truncation of the limb performed as the first amputation, early femoral stump ischaemia (EFSI) within 3 postoperative months was found to have occurred in 43 (27.6%) patients, whereas amongst 127 patients first subjected to amputation of the crus and then to femoral truncation it occurred in 15 (13.2%) cases; p<0.05. The incidence rate of late femoral stump ischaemia (LFSI) was virtually similar in both groups, amounting to 5.8% (9 of 156) and 5.5% (7 of 127), respectively; p>0.05. The survival rate for patients without stump ischaemia at 12 months after amputation amounted to 79.4%, for those with EFSI to 50.0% (p=0.00928), and for those with LFSI to 71.4% (p=0.22576), whereas by the end of a 5-year follow up period these values appeared to equal 49.2%, 32.1% (p=0.13225) and 7.1% (p=0.01385), respectively. The obtained findings demonstrated that the risk factors for EFSI were as follows: the presence of a femoral stump on the contralateral side, grade III ischaemia, and proximal localization of the lesion of the arterial bed (odds ratio 3.3, 2.7 and 3.8, respectively); a risk factor for LFSI was the presence of a femoral stump on the contralateral side (odds ratio 6.0).


Asunto(s)
Muñones de Amputación/irrigación sanguínea , Amputación Quirúrgica , Isquemia , Efectos Adversos a Largo Plazo , Extremidad Inferior , Complicaciones Posoperatorias , Amputación Quirúrgica/efectos adversos , Amputación Quirúrgica/métodos , Amputación Quirúrgica/estadística & datos numéricos , Femenino , Humanos , Isquemia/diagnóstico , Isquemia/etiología , Isquemia/mortalidad , Efectos Adversos a Largo Plazo/diagnóstico , Efectos Adversos a Largo Plazo/mortalidad , Extremidad Inferior/irrigación sanguínea , Extremidad Inferior/cirugía , Masculino , Persona de Mediana Edad , Evaluación de Procesos y Resultados en Atención de Salud , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/mortalidad , Estudios Retrospectivos , Factores de Riesgo , Federación de Rusia/epidemiología , Tasa de Supervivencia
8.
Khirurgiia (Mosk) ; (11): 35-38, 2018.
Artículo en Ruso | MEDLINE | ID: mdl-30531751

RESUMEN

AIM: To investigate five-year survival, short- and long-term outcomes of hip stump ischemia treatment. MATERIAL AND METHODS: There were 383 patients with hip stump in 1997-2013. Critical hip stump ischemia in 3 months after amputation occurred in 45 patients. RESULTS: Two-fold decrease of 5-year survival was found. Five-year survival was higher 3 times in patients after arterial reconstruction compared with those without revascularization. The same tendency was confirmed in analysis of groups standardized by gender, age and type of arterial disease.


Asunto(s)
Muñones de Amputación/irrigación sanguínea , Cadera/irrigación sanguínea , Isquemia/cirugía , Recuperación del Miembro/métodos , Enfermedad Arterial Periférica/complicaciones , Procedimientos Quirúrgicos Vasculares , Amputación Quirúrgica/efectos adversos , Amputación Quirúrgica/mortalidad , Arterias/cirugía , Enfermedad Crónica , Cadera/cirugía , Humanos , Isquemia/mortalidad , Recuperación del Miembro/mortalidad , Enfermedad Arterial Periférica/cirugía , Estudios Retrospectivos , Factores de Riesgo , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/métodos , Procedimientos Quirúrgicos Vasculares/mortalidad
10.
Bull Exp Biol Med ; 158(5): 670-2, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25778656

RESUMEN

The therapeutic efficiency of recombinant thymosin ß4 (rTß4) synthesized by us was studied in vivo on spontaneous CBRB mouse model that is adequate to human chronic dermatitis. Three applications of the drug during a week significantly alleviated symptoms of the disease in female mice, and in complex with subsequent antibacterial and antifungal therapy led to a pronounced and lasting (2 months) therapeutic effect. The results attest to a possibility of using rTß4 in combination with the known treatment protocols for chronic inflammatory diseases of the skin.


Asunto(s)
Dermatitis/tratamiento farmacológico , Proteínas Recombinantes/uso terapéutico , Timosina/uso terapéutico , Animales , Enfermedad Crónica/tratamiento farmacológico , Modelos Animales de Enfermedad , Femenino , Ratones
11.
Nanotechnology ; 25(8): 085703, 2014 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-24492459

RESUMEN

We report on the effect of microstructure and geometrically induced modifications of the magnetic properties of granular CoCrPt:SiO2 films with weakly interacting magnetic grains deposited on pre-structured GaSb nanocone templates fabricated by an ion erosion technique. By tuning the irradiation conditions, nanocone patterns of different cone sizes were prepared (from 28 to 120 nm in diameter and 32 to 330 nm high, respectively). The influence of the intergranular exchange coupling was also investigated by varying the SiO2 content from 8 to 12 at.%. Deposition of CoCrPt:SiO2 on samples with small nanocones leads to a close magnetic grain packing, which results in the formation of extended magnetic domains larger than the average distance between the GaSb cones. In contrast, on larger nanocones, the magnetic coating grows on the side-walls, with a large separation between neighboring cones, leading to magnetic single-domain regions, which are correlated to the underlying structure. Magnetometry indicates that both remanence and coercivity decrease with increasing cone size and/or SiO2 content due to a combined effect of the angular distribution of the magnetic easy axis of the grains and the intergranular exchange coupling strength.

12.
Nanotechnology ; 24(14): 145702, 2013 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-23507583

RESUMEN

Magnetization reversal processes in Co/Pt multilayers prepared on nanoperforated templates are probed by magnetization relaxation measurements. The signature of pinning controlled domain wall movement as expected for percolated media is identified. This contrasts with the nucleation-type reversal mechanism of a Co/Pt reference film prepared on a smooth substrate. A zero field energy barrier of 93kBT is determined by fluctuation field measurements and is elucidated by micromagnetic calculations using the nudged elastic band method. This value is sufficiently large to qualify the material as a promising percolated medium.

13.
J Phys Chem Lett ; 14(4): 1000-1006, 2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36693119

RESUMEN

In rare-earth compounds with valence fluctuation, the proximity of the 4f level to the Fermi energy leads to instabilities of the charge configuration and the magnetic moment. Here, we provide direct experimental evidence for an induced magnetic polarization of the Eu3+ atomic shell with J = 0, due to intra-atomic exchange and spin-orbital coupling interactions with the Eu2+ atomic shell. By applying external pressure, a transition from antiferromagnetic to a fluctuating behavior in EuNiGe3 single crystals is probed. Magnetic polarization is observed for both valence states of Eu2+ and Eu3+ across the entire pressure range. The anomalous magnetism is discussed in terms of a homogeneous intermediate valence state where frustrated Dzyaloshinskii-Moriya couplings are enhanced by the onset of spin-orbital interaction and engender a chiral spin-liquid-like precursor.

14.
Nanotechnology ; 23(25): 255701, 2012 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-22652540

RESUMEN

Magnetotransport of individual rolled-up Fe(3)Si nanomembranes is investigated in a broad temperature range from 4.2 K up to 300 K in pulsed magnetic fields up to 55 T. The observed magnetoresistance (MR) has the following pronounced features: (i) MR is negative in the investigated intervals of temperature and magnetic field; (ii) its magnitude increases linearly with the magnetic field in a low-field region and reveals a gradual trend to saturation when the magnetic field increases; (iii) the MR effect becomes more pronounced with increasing temperature. These dependences of MR on the magnetic field and temperature are in line with predictions of the spin-disorder model of the spin-flip s-d interaction assisted with creation or annihilation of magnons, which is expected above a certain critical temperature. Comparison of the MR features in rolled-up and planar samples reveals a substantial increase of the critical temperature in the rolled-up tube, which is attributed to a new geometry and internal strain arising in the rolled-up nanomembranes, influencing the electronic and magnetic properties of the material.

15.
Sci Rep ; 12(1): 4976, 2022 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-35322132

RESUMEN

The theory of scattering of ultrashort laser pulses (USP) is the basis of diffraction analysis of matter using modern USP sources. At present, the peculiarities of interaction of USP with complex structures are not well developed. In general, the research focuses on the features of the interaction of USP with simple systems, these are atoms and simple molecules. Here we present a theory of scattering of ultrashort laser pulses on molecules with a multi-atomic structure, taking into account the specifics of the interaction of USP with such a substance. The simplicity of the obtained expressions allows them to be used in diffraction analysis. As an example, the scattering spectra of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are presented. It is shown that the theory developed here is more general in the scattering theory and passes into the previously known one if we consider the duration of the USP to be sufficiently long.


Asunto(s)
Rayos Láser , Luz , ARN
16.
Comput Biol Chem ; 101: 107775, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36240523

RESUMEN

Structural variation and different bioactivity of ionic liquids (ILs) make them highly promising for the development of novel biocides. Application of computational methods to the evaluation of potential antibacterial activity of chemical compounds is a useful, time- and cost-saving tool replacing numerous experimental syntheses. In the present study, quantitative structure-activity relationship (QSAR) modeling is applied to develop models (based on more than 800 data points) aiming to predict the minimal inhibitory concentration (MIC) of ILs against three types of human pathogens - Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The random forest model with the AlvaDesc descriptors in general demonstrates the best performance for all the three types of bacteria and is suggested as a final model. To interpret the final model and determine the most significant descriptors, a SHapley Additive exPlanation (SHAP) method was applied. Six amino acid ILs, which were synthesized for the first time, and five halogenide ionic liquids purchased, all based on 1-alkyl-3methylimidozolium cations with different alkyl chain lengths, C10, C12 and C14, are tested in vitro and used to validate the developed QSAR models. The data sets and developed model are available free of charge at http://ochem.eu/article/147386.


Asunto(s)
Líquidos Iónicos , Humanos , Líquidos Iónicos/farmacología , Líquidos Iónicos/química , Staphylococcus aureus , Antibacterianos/farmacología , Antibacterianos/química , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad Cuantitativa , Aprendizaje Automático , Escherichia coli
17.
J Chem Phys ; 134(8): 084306, 2011 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-21361538

RESUMEN

It is shown that the evolution of water vapor spectra in the 2500-5000 cm(-1) range recorded at 650 K and pressures up to 130 atms after subtraction of monomer contribution may be interpreted qualitatively well on the basis of experimental data on water dimer and trimer obtained from cold molecular beams and in He droplets. The proposed spectroscopic model considers water vapor as a mixture of nonideal monomers, dimers, and trimers at chemical equilibrium. The effect of line mixing is taken into account in the monomer spectrum modeling. Decomposition of the high temperature spectra allowed determining a dimer equilibrium constant that was compared with the previously known values. The contribution of water trimer is assessed. The performed analysis indicates that the number of bound dimers in water vapor is quite large, even at such a high temperature.

18.
J Nanosci Nanotechnol ; 11(3): 1958-67, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21449334

RESUMEN

Self-assembled magnetic colloidal suspensions are sought after by material scientists owing to its huge application potential. The biomedical applications of colloidal nanoparticles necessitate that they are biocompatible, non-interacting, monodispersed and hence the synthesis of such nanostructures has great relevance in the realm of nanoscience. Silica-coated superparamagnetic iron oxide nanoparticles based ferrofluids were prepared using polyethylene glycol as carrier fluid by employing a controlled co-precipitation technique followed by a modified sol-gel synthesis. A plausible mechanism for the formation of stable suspension of SiO2-coated Iron Oxide nanoparticles with a size of about 9 nm dispersed in polyethylene glycol (PEG) is proposed. Core-shell nature of the resultant SiO2-Iron Oxide nanocomposite was verified using transmission electron microscopy. Fourier transform-infrared spectroscopy studies were carried out to understand the structure and nature of chemical bonds. The result suggests that Iron Oxide exist in an isolated state inside silica matrix. Moreover, the presence of silanol bonds establishes the hydrophilic nature of silica shell confirming the formation of stable ferrofluid with PEG as carrier fluid. The magnetic characterization reveals the superparamagnetic behavior of the nanoparticles with a rather narrow distribution of blocking temperatures. These properties are not seen in ferrofluids prepared from Iron Oxide nanoparticles without SiO2 coating. The latter suggests the successful tuning of the inter-particle interactions preventing agglomeration of nanoparticles. Cytotoxicity studies on citric acid coated water based ferrofluid and silica-coated PEG-based ferrofluid were evaluated by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium chloride assay and it shows an enhanced compatibility for silica modified nanoparticles.


Asunto(s)
Materiales Biocompatibles/síntesis química , Supervivencia Celular/efectos de los fármacos , Compuestos Férricos/química , Nanoestructuras/administración & dosificación , Nanoestructuras/química , Nanoestructuras/ultraestructura , Dióxido de Silicio/química , Materiales Biocompatibles/farmacología , Cristalización/métodos , Células HeLa , Humanos , Magnetismo , Ensayo de Materiales , Tamaño de la Partícula , Soluciones
19.
Sci Rep ; 11(1): 3571, 2021 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-33574452

RESUMEN

It is well known that the scattering of ultrashort pulses (USPs) of an electromagnetic field in the X-ray frequency range can be used in diffraction analysis. When such USPs are scattered by various polyatomic objects, a diffraction pattern appears from which the structure of the object can be determined. Today, there is a technical possibility of creating powerful USP sources and the analysis of the scattering spectra of such pulses is a high-precision instrument for studying the structure of matter. As a rule, such scattering occurs at a frequency close to the carrier frequency of the incident USP. In this work, it is shown that for high-power USPs, where the magnetic component of USPs cannot be neglected, scattering at the second harmonic appears. The scattering of USPs by the second harmonic has a characteristic diffraction pattern which can be used to judge the structure of the scattering object; combining the scattering spectra at the first and second harmonics therefore greatly enhances the diffraction analysis of matter. Scattering spectra at the first and second harmonics are shown for various polyatomic objects: examples considered are 2D and 3D materials such as graphene, carbon nanotubes, and hybrid structures consisting of nanotubes. The theory developed in this work can be applied to various multivolume objects and is quite simple for X-ray structural analysis, because it is based on analytical expressions.

20.
Sci Rep ; 11(1): 10274, 2021 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-33986464

RESUMEN

It is well known that a beam splitter (BS) can be used as a source of photon quantum entanglement. This is due to the fact that the statistics of photons changes at the output ports of the BS. Usually, quantum entanglement and photon statistics take into account the constancy of the reflection coefficient R or the transmission coefficient T of the BS, where [Formula: see text]. It has recently been shown that if BS is used in the form of coupled waveguides, the coefficients R and T will depend on the photon frequencies. In this paper, it is shown that the quantum entanglement and statistics of photons at the output ports of a BS can change significantly if a BS is used in the form of coupled waveguides, where the coefficients R and T are frequency-dependent.

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