Self-ignition of hydrogen–nitrogen mixtures during high-pressure release into air

This paper demonstrates experimental and numerical study on spontaneous ignition of H2–N2 mixtures during high-pressure release into air through the tubes of various diameters and lengths. The mixtures included 5% and 10% (vol.) N2 addition to hydrogen being at initial pressure in range of 4.3–15.9 MPa. As a point of reference pure hydrogen release experiments were performed with use of the same experimental stand, experimental procedure and extension tubes. The results showed that N2 addition may increase the initial pressure necessary to self-ignite the mixture as much as 2.12 or 2.85 – times for 5% and 10% N2 addition, respectively. Additionally, simulations were performed with use of Cantera code (0-D) based on the ideal shock tube assumption and with the modified KIVA3V code (2-D) to establish the main factors responsible for ignition and sustained combustion during the release

Advanced, lately diagnosed primary hyperparathyroidism in a patient mistakenly treated for multiple bone metastasis. A case report and review of the literature

We report a case of 66-years-old woman mistakenly diagnosed as a metasases’ dissemination on a basis of mulitifocal skeleton lesion showed by 99mTc-MDP scanning, high serum calcium level and a vague breast tumour history. Additionally she suffered had humer and femur fractures. Immobilised and diagnosed as a cancer patient, she he was referred to palliative care. In hospice for the first time the suspicion of hyperparathyroidism was raised. When 99mTc-MIBI SPECT/CT scan revealed a parathyroid adenoma, also considering her biochemical parameters, she underwent the surgery. Following this her biochemical parameters normalised. This case illustrates a pitfall, which sometimes happens in this rare disease. A review of literature is provided.We report a case of 66-years-old woman mistakenly diagnosed as a metasases’ dissemination on a basis of mulitifocal skeleton lesion showed by 99mTc-MDP scanning, high serum calcium level and a vague breast tumour history. Additionally she suffered had humer and femur fractures. Immobilised and diagnosed as a cancer patient, she he was referred to palliative care. In hospice for the first time the suspicion of hyperparathyroidism was raised. When 99mTc-MIBI SPECT/CT scan revealed a parathyroid adenoma, also considering her biochemical parameters, she underwent the surgery. Following this her biochemical parameters normalised. This case illustrates a pitfall, which sometimes happens in this rare disease. A review of literature is provided

Interleukin 2-regulated in vitro antibody production following a single spinal manipulative treatment in normal subjects

<p>Abstract</p> <p>Background</p> <p>Our recent investigations have demonstrated that cell cultures from subjects, who received a single spinal manipulative treatment in the upper thoracic spine, show increased capacity for the production of the key immunoregulatory cytokine, interleukin-2. However, it has not been determined if such changes influence the response of the immune effector cells. Thus, the purpose of the present study was to determine whether, in the same subjects, spinal manipulation-related augmentation of the <it>in vitro </it>interleukin-2 synthesis is associated with the modulation of interleukin 2-dependent and/or interleukin-2-induced humoral immune response (antibody synthesis).</p> <p>Methods</p> <p>A total of seventy-four age and sex-matched healthy asymptomatic subjects were studied. The subjects were assigned randomly to: venipuncture control (n = 22), spinal manipulative treatment without cavitation (n = 25) or spinal manipulative treatment associated with cavitation (n = 27) groups. Heparinized blood samples were obtained from the subjects before (baseline) and then at 20 minutes and 2 hours post-treatment. Immunoglobulin (antibody) synthesis was induced in cultures of peripheral blood mononuclear cells by stimulation with conventional pokeweed mitogen or by application of human recombinant interleukin-2. Determinations of the levels of immunoglobulin G and immunoglobulin M production in culture supernatants were performed by specific immunoassays.</p> <p>Results</p> <p>The baseline levels of immunoglobulin synthesis induced by pokeweed mitogen or human recombinant interleukin-2 stimulation were comparable in all groups. No significant changes in the production of pokeweed mitogen-induced immunoglobulins were observed during the post-treatment period in any of the study groups. In contrast, the production of interleukin-2 -induced immunoglobulin G and immunoglobulin M was significantly increased in cultures from subjects treated with spinal manipulation. At 20 min post-manipulation, immunoglobulin G synthesis was significantly elevated in subjects who received manipulation with cavitation, relative to that in cultures from subjects who received manipulation without cavitation and venipuncture alone. At 2 hr post-treatment, immunoglobulin M synthesis was significantly elevated in subjects who received manipulation with cavitation relative to the venipuncture group. There were no quantitative alterations within the population of peripheral blood B or T lymphocytes in the studied cultures.</p> <p>Conclusion</p> <p>Spinal manipulative treatment does not increase interleukin-2 -dependent polyclonal immunoglobulin synthesis by mitogen-activated B cells. However, antibody synthesis induced by interleukin-2 alone can be, at least temporarily, augmented following spinal manipulation. Thus, under certain physiological conditions spinal manipulative treatment might influence interleukin-2 -regulated biological responses.</p

DETERMINATION OF DETONABLE GAS MIXTURE HEAT FLUXES AT THERMAL DEBURRING

Modern technology requires a multitude of precise parts that are a necessity in reliable methods of surface finishing. Energy of detonable gas mixture combustion has been used in manufacturing as a processing source for a long time. One of the most underappreciated methods is thermal deburring; this is caused by certain difficulties in modelling and simulation of this process due to a complex and poorly predictable nature of the combustion. A theoretical approach towards thermal deburring process using the conception of an equivalent chamber is described. Processing of combined experimental and computational data results in a simplified model of thermal deburring in the case with deflagration and combustion with a shock waves formation. The proposed mathematical model was verified by an experimental investigation of the combustion in a shock tube, the difference of compared parameters did not exceed 3%. The heat fluxes at thermal deburring by combustible gas mixtures and their distribution on part surfaces according to the direction of the shock waves propagation were calculated. A relation between the value of the heat flux and shock waves propagation was found with a convincing repeating trend

Prediction of Deflagrative Explosions in Variety of Closed Vessels

In this paper the multi-phenomena deflagration model is used to simulate deflagrative combustion of several fuel–air mixtures in various scale closed vessels. The experimental transient pressure of methane–air, ethane–air, and propane–air deflagrations in vessels of volume 0.02 m3, 1 m3, and 6 m3 were simulated. The model includes key mechanisms affecting propagation of premixed flame front: the dependence of laminar burning velocity of concentration, pressure, and temperature; the effect of preferential diffusion in the corrugated flame front or leading point concept; turbulence generated by flame front itself or Karlovitz turbulence; increase of the flame front area with flame radius by fractals; and turbulence in the unburned mixture. Laminar velocity dependence on concentration, pressure, and temperature were calculated using CANTERA software. Various scale and geometry of used vessels induces various combustion mechanism. Simulations allow insight into the dominating mechanism. The model demonstrated an acceptable predictive capability for a variety of fuels and vessel sizes

Role of germline aberrations affecting CTNNA1, MAP3K6 and MYD88 in gastric cancer susceptibility

Background: In approximately 10% of all gastric cancer (GC) cases, a heritable cause is suspected. A subset of these cases have a causative germline CDH1 mutation; however, in most cases the cause remains unknown. Our objective was to assess to what extent these remaining cases may be explained by germline mutations in the novel candidate GC predisposing genes CTNNA1, MAP3K6 or MYD88. Methods: We sequenced a large cohort of unexplained young and/or familial patients with GC (n=286) without a CDH1germline mutation for germline variants affecting CTNNA1, MAP3K6 and MYD88 using a targeted next-generation sequencing approach based on single-molecule molecular inversion probes. Results: Predicted deleterious germline variants were not encountered in MYD88, but recurrently observed in CTNNA1 (n=2) and MAP3K6 (n=3) in our cohort of patients with GC. In contrast to deleterious variants in CTNNA1, deleterious variants in MAP3K6 also occur frequently in the general population. Conclusions: Based on our results MAP3K6 should no longer be considered a GC predisposition gene, whereas deleterious CTNNA1 variants are confirmed as an infrequent cause of GC susceptibility. Biallelic MYD88 germline mutations are at most a very rare cause of GC susceptibility as no additional cases were identified

The usefulness of bone scannning for the diagnosis and evaluation of otogenic skull base osteomyelitis. A description of three cases

BACKGROUND: The aim of this report was to assess the usefulness of bone scanning in the diagnosis and evaluation of the skull base osteomyelitis. MATERIAL AND METHODS: Bone scanning was performed in three male patients with otogenic skull base osteomyelitis, aged 65&#8211;84 years utilizing Tc99m-MDP and dual-head gamma camera. RESULTS: In one case, bone scanning played a crucial role in establishing the diagnosis. In two cases, it provided confirmed MRI results. CT scanning was negative in two cases. CONCLUSIONS: Bone scans may give valuable information for establishing the diagnosis and assessing the severity of this disease, and add complementary physiological information to radiological imaging