75 research outputs found
Complex neuroimaging study of the proximal segment after rigid fixation and dynamic stabilization in patients with degenerative lumbar disease
Background. The development of the adjacent level syndrome and, as a consequence, adjacent segment degenerative disease are currently the most common complications of decompression and stabilization surgery with the development of segmental instability. The aim of the study. To conduct a comprehensive neuroimaging assessment of the proximal adjacent segment after rigid fixation and dynamic stabilization in degenerative lumbar disease. Materials and methods. We conducted a prospective multicenter study of the results of surgical treatment of 274 patients with degenerative-dystrophic diseases of the lumbar spine, who underwent monosegmental decompression and stabilization surgery using the TLIF (transforaminal lumbar interbody fusion) technique and open transpedicular rigid fixation, as well as open hemilaminectomy with stabilization of the operated segments with nitinol rods. The study included radiography, diffusion-weighted magnetic resonance imaging and computed tomography (dualenergy mode) of intervertebral discs and isolated facet degeneration of the upper adjacent level. Results and discussion. Combination of the initial proximal segment degeneration in the form of facet joints degeneration (density of cartilaginous plate – 163.5 ± 14.2 HU, density of external facet – 709.35 ± 13.6 HU, density of internal facet – 578.1 ± 12.1 HU), Pfirrmann III, IV grade degeneration of intervertebral disc and a measured diffusion coefficient of less than 1300 mm2/s cause high risks of developing adjacent segment degenerative disease, which regulates the use of monosegmental dynamic fixation with nitinol rods, or preventive rigid fixation of the adjacent segment. Conclusion. Using complex neuroimaging in the preoperative period makes it possible to predict the results of surgical treatment, take timely measures to prevent degenerative diseases of the adjacent segment, and to carry out dynamic monitoring of processes in the structures of the spinal motion segment
Experimental study of negative photoconductivity in n-PbTe(Ga) epitaxial films
We report on low-temperature photoconductivity (PC) in n-PbTe(Ga) epitaxial
films prepared by the hot-wall technique on -BaF_2 substrates. Variation
of the substrate temperature allowed us to change the resistivity of the films
from 10^8 down to 10_{-2} Ohm x cm at 4.2 K. The resistivity reduction is
associated with a slight excess of Ga concentration, disturbing the Fermi level
pinning within the energy gap of n-PbTe(Ga). PC has been measured under
continuous and pulse illumination in the temperature range 4.2-300 K. For films
of low resistivity, the photoresponse is composed of negative and positive
parts. Recombination processes for both effects are characterized by
nonexponential kinetics depending on the illumination pulse duration and
intensity. Analysis of the PC transient proves that the negative
photoconductivity cannot be explained in terms of nonequilibrium charge
carriers spatial separation of due to band modulation. Experimental results are
interpreted assuming the mixed valence of Ga in lead telluride and the
formation of centers with a negative correlation energy. Specifics of the PC
process is determined by the energy levels attributed to donor Ga III, acceptor
Ga I, and neutral Ga II states with respect to the crystal surrounding. The
energy level corresponding to the metastable state Ga II is supposed to occur
above the conduction band bottom, providing fast recombination rates for the
negative PC. The superposition of negative and positive PC is considered to be
dependent on the ratio of the densities of states corresponding to the donor
and acceptor impurity centers.Comment: 7 pages, 4 figure
The first report of RPSA polymorphisms, also called 37/67 kDa LRP/LR gene, in sporadic Creutzfeldt-Jakob disease (CJD)
<p>Abstract</p> <p>Background</p> <p>Although polymorphisms of <it>PRNP</it>, the gene encoding prion protein, are known as a determinant affecting prion disease susceptibility, other genes also influence prion incubation time. This finding offers the opportunity to identify other genetic or environmental factor (s) modulating susceptibility to prion disease. Ribosomal protein SA (<it>RPSA</it>), also called 37 kDa laminin receptor precursor (LRP)/67 kDa laminin receptor (LR), acts as a receptor for laminin, viruses and prion proteins. The binding/internalization of prion protein is dependent for LRP/LR.</p> <p>Methods</p> <p>To identify other susceptibility genes involved in prion disease, we performed genetic analysis of <it>RPSA</it>. For this case-control study, we included 180 sporadic Creutzfeldt-Jakob disease (CJD) patients and 189 healthy Koreans. We investigated genotype and allele frequencies of polymorphism on <it>RPSA </it>by direct sequencing or restriction fragment length polymorphism (RFLP) analysis.</p> <p>Results</p> <p>We observed four single nucleotide polymorphisms (SNPs), including -8T>C (rs1803893) in the 5'-untranslated region (UTR) of exon 2, 134-32C>T (rs3772138) in the intron, 519G>A (rs2269350) in the intron and 793+58C>T (rs2723) in the intron on the <it>RPSA</it>. The 519G>A (at codon 173) is located in the direct PrP binding site. The genotypes and allele frequencies of the <it>RPSA </it>polymorphisms showed no significant differences between the controls and sporadic CJD patients.</p> <p>Conclusion</p> <p>These results suggest that these <it>RPSA </it>polymorphisms have no direct influence on the susceptibility to sporadic CJD. This was the first genetic association study of the polymorphisms of <it>RPSA </it>gene with sporadic CJD.</p
Secukinumab, an Interleukin-17A Inhibitor, in Ankylosing Spondylitis
Background Secukinumab is an anti–interleukin-17A monoclonal antibody that has been shown to control the symptoms of ankylosing spondylitis in a phase 2 trial. We conducted two phase 3 trials of secukinumab in patients with active ankylosing spondylitis. Methods In two double-blind trials, we randomly assigned patients to receive secukinumab or placebo. In MEASURE 1, a total of 371 patients received intravenous secukinumab (10 mg per kilogram of body weight) or matched placebo at weeks 0, 2, and 4, followed by subcutaneous secukinumab (150 mg or 75 mg) or matched placebo every 4 weeks starting at week 8. In MEASURE 2, a total of 219 patients received subcutaneous secukinumab (150 mg or 75 mg) or matched placebo at baseline; at weeks 1, 2, and 3; and every 4 weeks starting at week 4. At week 16, patients in the placebo group were randomly reassigned to subcutaneous secukinumab at a dose of 150 mg or 75 mg. The primary end point was the proportion of patients with at least 20% improvement in Assessment of Spondyloarthritis International Society (ASAS20) response criteria at week 16. Results In MEASURE 1, the ASAS20 response rates at week 16 were 61%, 60%, and 29% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for both comparisons with placebo); in MEASURE 2, the rates were 61%, 41%, and 28% for subcutaneous secukinumab at doses of 150 mg and 75 mg and for placebo, respectively (P<0.001 for the 150-mg dose and P=0.10 for the 75-mg dose). The significant improvements were sustained through 52 weeks. Infections, including candidiasis, were more common with secukinumab than with placebo during the placebo-controlled period of MEASURE 1. During the entire treatment period, pooled exposure-adjusted incidence rates of grade 3 or 4 neutropenia, candida infections, and Crohn’s disease were 0.7, 0.9, and 0.7 cases per 100 patient-years, respectively, in secukinumab-treated patients. Conclusions Secukinumab at a subcutaneous dose of 150 mg, with either subcutaneous or intravenous loading, provided significant reductions in the signs and symptoms of ankylosing spondylitis at week 16. Secukinumab at a subcutaneous dose of 75 mg resulted in significant improvement only with a higher intravenous loading dose. (Funded by Novartis Pharma; ClinicalTrials.gov numbers, NCT01358175 and NCT01649375.
The Waveguide Device for Measurement Dielectric Constant of a Heterogeneous Dispersed Liquid Media
В статье представлено новое волноводное устройство для измерения диэлектрической проницаемости гетерогенных дисперсных жидких сред. Работа устройства основана на использовании эффекта релейной смены режима работы волноводной линии передачи в целях контроля параметров гетерогенных дисперсных жидких сред. Подробно описывается моделирование устройства в CST Studio suit при измерении диэлектрической проницаемости авиационного керосина со свободной влагой и механическими примесями. Характеристики волноводного устройства позволяют проводить высокоточные измерения диэлектрической проницаемости гетерогенных жидких средIn this paper a new waveguide device for control the dielectric permittivity of heterogeneous dispersed liquid media is presented. Device operation is based on the effect relay changing the operating mode of the waveguide transmission line in order to control a parameters of heterogeneous dispersed liquid media. It is spoken in detail CST Studio suit simulation device when measuring the dielectric constant of aviation fuel with a free moisture and mechanical impurity. Characteristics waveguide device allows to perform high precision measurement of the permittivity heterogeneous liquid medi
Effect of the screen thickness on performance of double periodic perforated diffracton gratings. (in Russian)
Diffraction of electromagnetic waves on aperture array of finite thickness. (in Russian)
The Waveguide Device for Measurement Dielectric Constant of a Heterogeneous Dispersed Liquid Media
В статье представлено новое волноводное устройство для измерения диэлектрической проницаемости гетерогенных дисперсных жидких сред. Работа устройства основана на использовании эффекта релейной смены режима работы волноводной линии передачи в целях контроля параметров гетерогенных дисперсных жидких сред. Подробно описывается моделирование устройства в CST Studio suit при измерении диэлектрической проницаемости авиационного керосина со свободной влагой и механическими примесями. Характеристики волноводного устройства позволяют проводить высокоточные измерения диэлектрической проницаемости гетерогенных жидких средIn this paper a new waveguide device for control the dielectric permittivity of heterogeneous dispersed liquid media is presented. Device operation is based on the effect relay changing the operating mode of the waveguide transmission line in order to control a parameters of heterogeneous dispersed liquid media. It is spoken in detail CST Studio suit simulation device when measuring the dielectric constant of aviation fuel with a free moisture and mechanical impurity. Characteristics waveguide device allows to perform high precision measurement of the permittivity heterogeneous liquid medi
Renomedullary interstitial cell tumor: review of a rare clinical case
Autopsy study of a 49-year-old patient demonstrates a rare kidney tumor that had a structure of a mesenchymal renomedullary interstitial tumor (RIO), which had specific characteristics. They include a predominance of the cellular component in the tumor, represented by cells with processes elements (fibroblasts, myofibroblasts), which were surrounded by collagen fibers of interstitium. Apparently, these cells can be involved in the regulation of renin and bicarbonates, the exchange of components of connective tissue (collagen fibers, proteoglycans) and hormones (estrogen, progesterone). Since these tumor cells regulate the synthesis and secretion of the substances, numerous clinical manifestations of RIO can be explained. Most likely, these include increased blood pressure, water-electrolyte disorders, hormonal disorders due to the presence of estrogen receptors, progesterone in the tumor tissue and metabolic disorders (diabetes mellitus). However, these assumptions require further clinical, morphological and immunohistochemical studies
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