35 research outputs found
Investigation of spontaneous combustion tendency of vegetable oils by the means of differential thermal analysis
The potential of vegetable oils to undergo violent thermal oxidation is long-known
problem. The process of this oxidation is investigated by the means of differential thermal
analysis. Polyurethane foam was saturated with Tung oil rich in unsaturated fatty acids at
three different mass rations, and airfl ow at three different rates is introduces to the sample
to ensure suffi cient volume of air for oxidation. The samples were thermally stressed
both dynamically and isothermally. The results were compared to results of standard
differential Mackey test
Enhanced pulmonary expression of the TrkB neurotrophin receptor in hypoxic rats is associated with increased acetylcholine-induced airway contractility
AIM
We have recently reported that hypoxia stimulates transcription of the TrkB neurotrophin receptor in cultured cells via stabilization of hypoxia-inducible factor-1alpha. Here we investigated whether the expression of TrkB and other neurotrophin receptors is oxygen-sensitive also in vivo, and explored the functional consequences of an oxygen-regulated TrkB expression.
METHODS
Rats were exposed either to 21% O(2) or 8% O(2) for 6 h and TrkB was analysed by reverse transcription real-time PCR, in situ mRNA hybridization, and immunological techniques. The importance of the brain-derived neurotrophic factor (BDNF)-TrkB pathway in the control of mechanical airway function was assessed on isolated tracheal segments from normoxic and hypoxic rats.
RESULTS
TrkB transcripts were increased approx. 15-fold in the lungs of hypoxic rats, and the respiratory epithelium was identified as the site of enhanced TrkB expression in hypoxia. The TrkB ligand, BDNF, significantly increased the contractile response to acetylcholine (ACh) of isolated tracheal segments from hypoxic but not from normoxic rats. This effect of BDNF was prevented by pre-incubation of the tissue specimens with the tyrosine kinase inhibitor K252a and by mechanical removal of the TrkB containing airway epithelium. Likewise, the nitric oxide (NO) synthase inhibitor l-NAME abrogated the influence of BDNF on ACh-induced contractions of isolated tracheal segments from hypoxic rats.
CONCLUSION
These results demonstrate that systemic hypoxia stimulates expression of the TrkB neurotrophin receptor in the airway epithelium. Furthermore, activation of TrkB signalling by BDNF in hypoxia enhances mechanical airway contractility to ACh through a mechanism that requires NO
Učinak toplinske obrade na proces izgaranja drva smreke (Picea abies)
This paper deals with the effect of thermal treatment of spruce wood on its burning process. Samples of 100 mm x 100 mm were dried out and then heat-treated at 150 °C, 200 °C, 250 °C and 300 °C. Thus prepared samples were tested on a cone calorimeter at a heat flow of 50 kW·m-2. The obtained results clearly show that with the increasing temperature of the treatment, the released heat from the surface unit decreases and the unit weight increases. The carbon dioxide concentration in the flue gas increases as well, however, the optical density of the smoke decreases substantially. It can be stated that the burning of spruce wood is considerably affected mainly by the thermal treatment at temperatures above 200 °C. From the point of view of the use of spruce wood as fuel, the most optimal treatment temperature is 250 °C.U radu se razmatra učinak toplinske obrade smrekova drva na proces njegova gorenja. Uzorci dimenzija 100 x 100 mm osušeni su i zatim toplinski obrađeni na 150, 200, 250 i 300 °C. Tako pripremljeni uzorci ispitani su na konusnom kalorimetru, pri toplinskom toku od 50 kW·m-2. Iz dobivenih se rezultata može uočiti da se povećanjem temperature toplinske obrade smanjuje oslobođena toplina površinske jedinice i povećava jedinična težina uzoraka od smrekovine. Koncentracija ugljikova dioksida u dimnom plinu također se povećava, ali se optička gustoća dima znatno smanjuje. Može se također zaključiti da na izgaranje smrekovine uglavnom znatno utječe toplinska obrada pri temperaturama višim od 200 °C. S gledišta upotrebe smrekovine kao ogrjeva, optimalna je temperatura toplinske obrade tog drva 250 °C
A new approach to the assessment of the reduction in visibility caused by fires of electrical cables
Electricity is the most important form of household energy and one of the most important forms of energy for industry and transport. Electrical distribution in construction and transport is almost exclusively implemented using electrical cables. One of the unresolved problems associated with electrical cables is the release of smoke and the resulting reduction of visibility in case of fire in the area. In this study, a new approach was developed to assess the reduction of visibility in an area affected by an electrical cable fire. This approach is based on the determination of the critical ratio of smoke volume (in the smoke layer and exhausted from the fire compartment) to the length of the burning cable, through which the visibility of reflective and illuminated signs was reduced to a lower limit value (a standard of 10 m). The input data for this approach was the extinction area of the smoke released from one meter of burning cable and the length of the cables in the area. This approach was used to test two power cables (CHKE-V J3x1.5 and CHKE-R J3x1.5) and one signal cable J-H(St)H 1 x 2 x 0.8 with the B2(ca), s1, d1, a1 fire reaction class. The smoke extinction area of the examined cables was determined using a cone calorimeter at a heat flux of 50 kW/m(2). The obtained data showed that in order to maintain a visibility of 10 m for reflective signs, the critical ratio of smoke volume to length of burning cable was 7.5 m(3)/m. For illuminated signs, the critical ratio was 2.8 m(3)/m. The relationship between burning length and visibility allows the calculation of visibility in the fire compartment affected by cable fire only from cables length.Web of Science53art. no. 4
Translating recent results from the Cardiovascular Outcomes Trials into clinical practice: recommendations from the Central and Eastern European Diabetes Expert Group (CEEDEG)
Aims: These recommendations aim to improve care for patients with type 2 diabetes (T2D) at high cardiovascular (CV) risk in Central and Eastern Europe. Cardiovascular disease (CVD) and/or chronic kidney disease (CKD) are major interdependent comorbidities in patients with T2D, accounting for 50% of mortality. Following recent CV outcomes trial (CVOT) results, including those from EMPA-REG -OUTCOME (R), LEADER (R), SUSTAIN (TM)-6 and, most recently, the CANVAS study, it is essential to develop regional expert consensus recommendations to aid physicians in interpreting these newest data to clinical practice. Methods: The Central and Eastern European Diabetes Expert Group (CEEDEG) followed a Delphi method to develop treatment algorithms to aid physicians in the clinical management of patients with T2D at high CV risk. Results: In light of the latest CVOT results, and in particular the EMPA-REG -OUTCOME (R) and -LEADER (R) trials, the diagnosis, assessment, treatment choice and monitoring of patients with T2D and established CVD and/or CKD have been considered together with existing guidelines and presented in two reference algorithms. In addition, adherence, special prescribing considerations and a proposed multidisciplinary management approach have been discussed and are presented with the proposed algorithms. Conclusions: The latest available high-level evidence on glucose-lowering drugs has enabled CEEDEG to develop practical consensus recommendations for patients with established CVD and/ or CKD. These recommendations represent an update to international and country-level guidelines used for these patients, with the aim of providing a resource not only to endocrinologists, but to cardiologists, nephrologists and primary care physicians in the region
Canagliflozin and renal outcomes in type 2 diabetes and nephropathy
BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead