Quantum beam splitter based on free charged particles.

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.

Specificity of scattering of ultrashort laser pulses by molecules with polyatomic structure.

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.

Quantum entanglement and statistics of photons on a beam splitter in the form of coupled waveguides.

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.

X-ray diffraction analysis of matter taking into account the second harmonic in the scattering of powerful ultrashort pulses of an electromagnetic field.

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.

[Five-year survival and outcomes of chronic hip stump ischemia treatment]. / Piatiletniaia vyzhivaemost' i rezul'taty lecheniia khronicheskoi ishemii kul'ti bedra.

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.

[Ischaemia of a femoral stump in short- and long-term periods after limb amputation]. / Ishemiia kul'ti bedra v rannem i pozdnem periodakh posle amputatsii.

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).