6 research outputs found
Use of Addenbrooke’s cognitive examination-revised to evaluate the patients’ state in general medical practice
The differential diagnosis of cognitive impairments is of great importance in mental disorders detectable in general medical practice. Objective: to study whether Addenbrooke's Cognitive Examination — Revised (ACE-R) may be used in these patients. Patients and methods. The study was conducted in two steps at somatic hospitals and city polyclinics. It enrolled 130patients (36 men and 94 women) with anxiety-depression spectrum disorders (ADSD), mild cognitive disorders (MCD) and a concurrence of these conditions. The authors used the following psychometric scales: the hospital anxiety and depression scale; the mini-mental state examination; the frontal assessment battery; ACE-R; ten words learning test. The psychometric characteristics of ACE-R and the possibilities of its use were estimated to detect MCD. The differences in the spectrum of cognitive impairments were analyzed in patients with different types of ADSD. Results. ACE-R is shown to be an effective neuropsychological tool for the primary diagnosis, detection, and evaluation of MCD in the general medical network. The results of ACE-R use indicate that the spectrum of cognitive impairments has substantial differences in patients with different types of non-psychotic disorders
Optical Biomedical Imaging Reveals Criteria for Violated Liver Regenerative Potential
To reduce the risk of post-hepatectomy liver failure in patients with hepatic pathologies, it is necessary to develop an approach to express the intraoperative assessment of the liver’s regenerative potential. Traditional clinical methods do not enable the prediction of the function of the liver remnant. Modern label-free bioimaging, using multiphoton microscopy in combination with second harmonic generation (SHG) and fluorescence lifetime imaging microscopy (FLIM), can both expand the possibilities for diagnosing liver pathologies and for assessing the regenerative potential of the liver. Using multiphoton and SHG microscopy, we assessed the structural state of liver tissue at different stages of induced steatosis and fibrosis before and after 70% partial hepatectomy in rats. Using FLIM, we also performed a detailed analysis of the metabolic state of the hepatocytes. We were able to determine criteria that can reveal a lack of regenerative potential in violated liver, such as the presence of zones with reduced NAD(P)H autofluorescence signals. Furthermore, for a liver with pathology, there was an absence of the jump in the fluorescence lifetime contributions of the bound form of NADH and NADPH the 3rd day after hepatectomy that is characteristic of normal liver regeneration. Such results are associated with decreased intensity of oxidative phosphorylation and of biosynthetic processes in pathological liver, which is the reason for the impaired liver recovery. This modern approach offers an effective tool that can be successfully translated into the clinic for express, intraoperative assessment of the regenerative potential of the pathological liver of a patient
Optical Biomedical Imaging Reveals Criteria for Violated Liver Regenerative Potential
To reduce the risk of post-hepatectomy liver failure in patients with hepatic pathologies, it is necessary to develop an approach to express the intraoperative assessment of the liver’s regenerative potential. Traditional clinical methods do not enable the prediction of the function of the liver remnant. Modern label-free bioimaging, using multiphoton microscopy in combination with second harmonic generation (SHG) and fluorescence lifetime imaging microscopy (FLIM), can both expand the possibilities for diagnosing liver pathologies and for assessing the regenerative potential of the liver. Using multiphoton and SHG microscopy, we assessed the structural state of liver tissue at different stages of induced steatosis and fibrosis before and after 70% partial hepatectomy in rats. Using FLIM, we also performed a detailed analysis of the metabolic state of the hepatocytes. We were able to determine criteria that can reveal a lack of regenerative potential in violated liver, such as the presence of zones with reduced NAD(P)H autofluorescence signals. Furthermore, for a liver with pathology, there was an absence of the jump in the fluorescence lifetime contributions of the bound form of NADH and NADPH the 3rd day after hepatectomy that is characteristic of normal liver regeneration. Such results are associated with decreased intensity of oxidative phosphorylation and of biosynthetic processes in pathological liver, which is the reason for the impaired liver recovery. This modern approach offers an effective tool that can be successfully translated into the clinic for express, intraoperative assessment of the regenerative potential of the pathological liver of a patient
Towards Bright Single-Photon Emission in Elliptical Micropillars
In recent years, single-photon sources (SPSs) based on the emission of a single semiconductor quantum dot (QD) have been actively developed. While the purity and indistinguishability of single photons are already close to ideal values, the high brightness of SPSs remains a challenge. The widely used resonant excitation with cross-polarization filtering usually leads to at least a two-fold reduction in the single-photon counts rate, since single-photon emission is usually unpolarized, or its polarization state is close to that of the exciting laser. One of the solutions is the use of polarization-selective microcavities, which allows one to redirect most of the QD emission to a specific polarization determined by the optical mode of the microcavity. In the present work, elliptical micropillars with distributed Bragg reflectors are investigated theoretically and experimentally as a promising design of such polarization-selective microcavities. The impact of ellipticity, ellipse area and verticality of the side walls on the splitting of the optical fundamental mode is investigated. The study of the near-field pattern allows us to detect the presence of higher-order optical modes, which are classified theoretically. The possibility of obtaining strongly polarized single-photon QD radiation associated with the short-wavelength fundamental cavity mode is shown
Design optimization for bright electrically-driven quantum dot single-photon sources emitting in telecom O-band
© 2021 Optica Publishing Group. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.A combination of advanced light engineering concepts enables a substantial improvement in photon extraction efficiency of micro–cavity–based single–photon sources in the telecom O–band at ∼1.3 µm. We employ a broadband bottom distributed Bragg reflector (DBR) and a top DBR formed in a dielectric micropillar with an additional circular Bragg grating in the lateral plane. This device design includes a doped layer in pin–configuration to allow for electric carrier injection. It provides broadband (∼8–10 nm) emission enhancement with an overall photon–extraction efficiency of ∼83% into the upper hemisphere and photon–extraction efficiency of ∼79% within numerical aperture NA=0.7. The efficiency of photon coupling to a single–mode fiber reaches 11% for SMF28 fiber (with NA=0.12), exceeds 22% for 980HP fiber (with NA=0.2) and reaches ∼40% for HNA fiber (with NA=0.42) as demonstrated by 3D finite–difference time–domain modeling