49 research outputs found

    The method of long-life calculation for a friction couple “rotor – hybrid bearing”

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    Reliability of rotating machinery is determined to a considerable degree by the bearing units. For several applications the requirements in rotation speed, bearing load and maximal vibration level are so extreme that neither rolling-element bearings nor fluid-film bearings could provide necessary performance characteristics during all regimes of operation. Hybrid bearings, which are a combination of rolling-element and fluid-film bearings, can improve performance characteristics and reliability of the rotor-bearing systems. The article presents the approach for to formation of the method of resource calculation for hybrid bearing with speed separation. The results show that the resource of the slide bearing increases significantly when it is used in combination with a rolling-element bearing compared to its single setting

    Global Retinoblastoma Presentation and Analysis by National Income Level

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    Importance: Early diagnosis of retinoblastoma, the most common intraocular cancer, can save both a child's life and vision. However, anecdotal evidence suggests that many children across the world are diagnosed late. To our knowledge, the clinical presentation of retinoblastoma has never been assessed on a global scale. Objectives: To report the retinoblastoma stage at diagnosis in patients across the world during a single year, to investigate associations between clinical variables and national income level, and to investigate risk factors for advanced disease at diagnosis. Design, Setting, and Participants: A total of 278 retinoblastoma treatment centers were recruited from June 2017 through December 2018 to participate in a cross-sectional analysis of treatment-naive patients with retinoblastoma who were diagnosed in 2017. Main Outcomes and Measures: Age at presentation, proportion of familial history of retinoblastoma, and tumor stage and metastasis. Results: The cohort included 4351 new patients from 153 countries; the median age at diagnosis was 30.5 (interquartile range, 18.3-45.9) months, and 1976 patients (45.4%) were female. Most patients (n = 3685 [84.7%]) were from low- A nd middle-income countries (LMICs). Globally, the most common indication for referral was leukocoria (n = 2638 [62.8%]), followed by strabismus (n = 429 [10.2%]) and proptosis (n = 309 [7.4%]). Patients from high-income countries (HICs) were diagnosed at a median age of 14.1 months, with 656 of 666 (98.5%) patients having intraocular retinoblastoma and 2 (0.3%) having metastasis. Patients from low-income countries were diagnosed at a median age of 30.5 months, with 256 of 521 (49.1%) having extraocular retinoblastoma and 94 of 498 (18.9%) having metastasis. Lower national income level was associated with older presentation age, higher proportion of locally advanced disease and distant metastasis, and smaller proportion of familial history of retinoblastoma. Advanced disease at diagnosis was more common in LMICs even after adjusting for age (odds ratio for low-income countries vs upper-middle-income countries and HICs, 17.92 [95% CI, 12.94-24.80], and for lower-middle-income countries vs upper-middle-income countries and HICs, 5.74 [95% CI, 4.30-7.68]). Conclusions and Relevance: This study is estimated to have included more than half of all new retinoblastoma cases worldwide in 2017. Children from LMICs, where the main global retinoblastoma burden lies, presented at an older age with more advanced disease and demonstrated a smaller proportion of familial history of retinoblastoma, likely because many do not reach a childbearing age. Given that retinoblastoma is curable, these data are concerning and mandate intervention at national and international levels. Further studies are needed to investigate factors, other than age at presentation, that may be associated with advanced disease in LMICs

    Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

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    37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

    Transverse momentum spectra of charged particles in proton-proton collisions at s=900\sqrt{s} = 900 GeV with ALICE at the LHC

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    The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at s=900\sqrt{s} = 900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (η<0.8)(|\eta|<0.8) over the transverse momentum range 0.15<pT<100.15<p_{\rm T}<10 GeV/cc. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for η<0.8|\eta|<0.8 is <pT>INEL=0.483±0.001\left<p_{\rm T}\right>_{\rm INEL}=0.483\pm0.001 (stat.) ±0.007\pm0.007 (syst.) GeV/cc and \left_{\rm NSD}=0.489\pm0.001 (stat.) ±0.007\pm0.007 (syst.) GeV/cc, respectively. The data exhibit a slightly larger <pT>\left<p_{\rm T}\right> than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.Comment: 20 pages, 8 figures, 2 tables, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/390

    The global retinoblastoma outcome study : a prospective, cluster-based analysis of 4064 patients from 149 countries

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    DATA SHARING : The study data will become available online once all analyses are complete.BACKGROUND : Retinoblastoma is the most common intraocular cancer worldwide. There is some evidence to suggest that major differences exist in treatment outcomes for children with retinoblastoma from different regions, but these differences have not been assessed on a global scale. We aimed to report 3-year outcomes for children with retinoblastoma globally and to investigate factors associated with survival. METHODS : We did a prospective cluster-based analysis of treatment-naive patients with retinoblastoma who were diagnosed between Jan 1, 2017, and Dec 31, 2017, then treated and followed up for 3 years. Patients were recruited from 260 specialised treatment centres worldwide. Data were obtained from participating centres on primary and additional treatments, duration of follow-up, metastasis, eye globe salvage, and survival outcome. We analysed time to death and time to enucleation with Cox regression models. FINDINGS : The cohort included 4064 children from 149 countries. The median age at diagnosis was 23·2 months (IQR 11·0–36·5). Extraocular tumour spread (cT4 of the cTNMH classification) at diagnosis was reported in five (0·8%) of 636 children from high-income countries, 55 (5·4%) of 1027 children from upper-middle-income countries, 342 (19·7%) of 1738 children from lower-middle-income countries, and 196 (42·9%) of 457 children from low-income countries. Enucleation surgery was available for all children and intravenous chemotherapy was available for 4014 (98·8%) of 4064 children. The 3-year survival rate was 99·5% (95% CI 98·8–100·0) for children from high-income countries, 91·2% (89·5–93·0) for children from upper-middle-income countries, 80·3% (78·3–82·3) for children from lower-middle-income countries, and 57·3% (52·1-63·0) for children from low-income countries. On analysis, independent factors for worse survival were residence in low-income countries compared to high-income countries (hazard ratio 16·67; 95% CI 4·76–50·00), cT4 advanced tumour compared to cT1 (8·98; 4·44–18·18), and older age at diagnosis in children up to 3 years (1·38 per year; 1·23–1·56). For children aged 3–7 years, the mortality risk decreased slightly (p=0·0104 for the change in slope). INTERPRETATION : This study, estimated to include approximately half of all new retinoblastoma cases worldwide in 2017, shows profound inequity in survival of children depending on the national income level of their country of residence. In high-income countries, death from retinoblastoma is rare, whereas in low-income countries estimated 3-year survival is just over 50%. Although essential treatments are available in nearly all countries, early diagnosis and treatment in low-income countries are key to improving survival outcomes.The Queen Elizabeth Diamond Jubilee Trust and the Wellcome Trust.https://www.thelancet.com/journals/langlo/homeam2023Paediatrics and Child Healt

    The method of long-life calculation for a friction couple “rotor – hybrid bearing”

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    Reliability of rotating machinery is determined to a considerable degree by the bearing units. For several applications the requirements in rotation speed, bearing load and maximal vibration level are so extreme that neither rolling-element bearings nor fluid-film bearings could provide necessary performance characteristics during all regimes of operation. Hybrid bearings, which are a combination of rolling-element and fluid-film bearings, can improve performance characteristics and reliability of the rotor-bearing systems. The article presents the approach for to formation of the method of resource calculation for hybrid bearing with speed separation. The results show that the resource of the slide bearing increases significantly when it is used in combination with a rolling-element bearing compared to its single setting

    Development and Research of A Virtual Test Bench for Electric Impedance Tomography Channel Main Components Simulation

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    When developing and determining the principles of construction and algorithms for the operation of electrical impedance tomography devices, it is necessary to verify the adequacy of the adopted circuitry solutions, their technical level and the possibility of practical implementation. To assess the technical capabilities and operating parameters of the device and its components, it is advisable to develop specialized tools for research and adjustment. Considering that the devices for electrical impedance tomography being developed are hardware and software solutions, and their components are complete electronic units that interact with each other, it seems possible to develop an experimental bench.The development of a virtual automated experimental bench for preliminary tests of the main components of the electrical impedance tomography channel is proposed. On the basis of the operating principles of the hardware bench, the principles of building a virtual bench are formulated. The correspondence of the main elements of hardware and virtual benches in terms of their functional purpose is shown.For each of the software components of the virtual bench, input actions and output parameters are determined.A schematic diagram of the analog part of the electrical impedance tomography channel has been developed to test the performance of the virtual bench. Studies have shown that the developed virtual bench is suitable for preliminary testing of all analog components of the channel.The use of the developed virtual bench will allow optimizing the time and material costs for conducting experimental research in the process of developing hardware for technical means of electrical impedance tomograph

    A New Variant of Charcot-Marie-Tooth Disease Type 2 Is Probably the Result of a Mutation in the Neurofilament-Light Gene

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    Charcot-Marie-Tooth (CMT) disease is the most common inherited motor and sensory neuropathy. The axonal form of the disease is designated as “CMT type 2” (CMT2). Although four loci known to be implicated in autosomal dominant CMT2 have been mapped thus far (on 1p35-p36, 3q13.1, 3q13-q22, and 7p14), no one causative gene is yet known. A large Russian family with CMT2 was found in the Mordovian Republic (Russia). Affected members had the typical CMT2 phenotype. Additionally, several patients suffered from hyperkeratosis, although the association, if any, between the two disorders is not clear. Linkage with the CMT loci already known (CMT1A, CMT1B, CMT2A, CMT2B, CMT2D, and a number of other CMT-related loci) was excluded. Genomewide screening pinpointed the disease locus in this family to chromosome 8p21, within a 16-cM interval between markers D8S136 and D8S1769. A maximum two-point LOD score of 5.93 was yielded by a microsatellite from the 5′ region of the neurofilament-light gene (NF-L). Neurofilament proteins play an important role in axonal structure and are implicated in several neuronal disorders. Screening of affected family members for mutations in the NF-L gene and in the tightly linked neurofilament-medium gene (NF-M) revealed the only DNA alteration linked with the disease: a A998C transversion in the first exon of NF-L, which converts a conserved Gln333 amino acid to proline. This alteration was not found in 180 normal chromosomes. Twenty unrelated CMT2 patients, as well as 26 others with an undetermined form of CMT, also were screened for mutations in NF-L, but no additional mutations were found. It is suggested that Gln333Pro represents a rare disease-causing mutation, which results in the CMT2 phenotype

    On the volatility of nihonium (Nh, Z = 113

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    Gas-phase chromatography studies of nihonium (Nh, Z=113 Z=113 were carried out at the one-atom-at-a-time level. For the production of nihonium, the heavy-ion-induced nuclear fusion reaction of48^{48} Ca with243^{243} Am was used. This leads to isotopes284,285^{284, 285} Nh, as the direct descendants of the α\alpha -decaying precursors288,289^{288, 289} Mc. Combining the Dubna Gas-Filled Recoil Separator with gas-phase chromatographic separation, the experiment was sensitive to elemental nihonium and its adsorption behavior on Teflon, theoretically predicted by modern relativistic density functional theory. The non-observation of any decays of Nh after the chemical separation indicates a larger than expected retention of elemental Nh on a Teflon surface

    Prophylactic thyroidectomy results among RET germline mutation bearers in families with hereditary forms of medullary thyroid cancer

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    Genetically caused medullary thyroid cancer (MTC) is associated with unfavorable survival prognosis, so it makes necessary to develop new diagnostic techniques to reveal pre-clinical stage of disease as well as to introduce into clinical practice the effective method of tumor prevention. The article represents first in Russia summary clinical experience of prophylactic thyroidectomy have been executed in the period 1998 – 2015 yeas among ten bearers of RET gene germlinemutation in families with hereditary disease including syndrome MEN2A and familial MTC. Aim: to evaluate the results of surgical treatment of asymptomatic carriers of germinal mutations in the RET gene. Materials and methods. In the period from 1998 to 2015, in two centers: N.N. Blokhin Russian Cancer Research Center, Moscow and A. Tsyb Medical Radiological Research Centre – branch of the National Medical Research Radiological Centre, Obninsk was conducted prophylactic surgical treatment in 10 patients – asymptomatic carriers of germinal mutations in RET. Age of patients – from 2 to 23 years old. 9 patients – from families with the syndrome of multiple endocrineneoplasia type 2A (MEN2A), one – with the family of MTC. According to genealogy in 9 families of patients there have been cases of death from MTC or pheochromocytoma (PC). In all cases, surgical treatment was performed in a volume of TE, two patients additionally performed lymph node dissection VI level. The observation period after surgery ranged from 6 months to 16 years. Results. DNA diagnostics in 8 patients identified a mutation in exon 11, in one case – in exon 10 and one patient had revealed two mutations in exons 13 and 14. The age of patients ranged from 2 to 23 years. Basal calcitonin level was elevated in 7 of 10 patients. Such prophylactic TE in 2 patients was supplemented by selective lymph node dissection. Histological examination of the removal of the thyroid gland (TG) revealed foci of medullary cancer in 6 of 10. At 2 patients revealed a C-cell hyperplasia and at 2 patients were found signs of the well expressed and weakly expressed sclerosis in thyroid tissue. The earliest age to identify MTC was a child 3 years old, mutations in codon 634, from a family where relatives observed for aggressive MTC. In the course of follow-recurrence was detected in one patient, a child of 15 years, a similar mutation carrier. Conclusion. In view of the risk of MTC developing identifying a mutation in RET gene and preventive TE should be carried out as soon as possible. The high risk of MTC developing in RET-gene positive subjects was confirmed in this study (6 cases of cancer from 10 patients)
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