1,364 research outputs found
Evaluation of Wind Energy Potential in Tindouf, South West of Algeria
The wind energy is one of the most significant and rapidly developing renewable energy sources in the world and it provides a clean energy resource, which is a promising alternative in the short term in Algeria. The main purpose of this paper is to discuss the wind potential in Tindouf (south west of Algeria) and to perform an investigation on the wind power potential of desert of Algeria. The Weibull density function has been used to estimate the monthly power wind density and to determine the characteristics of monthly parameters of Weibull. A simulation model has been established to describe the characteristics of a particular wind turbine. The monthly power generated and the monthly operating hours by the wind turbine to be simulated. The simulation based on the data wind speed measured at the 10th meters and collected during 8760hours by wind observation station web site weather underground (The global weather data could be obtained from internet). Keywords: Weibull distribution; Parameters of Wiebull; Wind energy; Wind turbine ; operating hours
Impact of corpulence parameters and haemoglobin A1c on metabolic control in type 2 diabetic patients: comparison of apolipoprotein B/A-I ratio with fasting and postprandial conventional lipid ratios
Background and objective: The incidence of diabetes co-morbidities could probably be better assessed by studying its associations with major corpulence parameters and glycaemic control indicators. We assessed the utility of body mass index (BMI), waist circumference (WC), and glycosylated haemoglobin (HbA1c) levels in metabolic control for type 2 diabetic patients.Methods: Fasting and postprandial blood samples were collected from 238 type 2 diabetic patients aged 57.4911.9 years. The sera were analysed for glucose, HbA1c, total cholesterol (TC), triglycerides (TG), highdensity lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), and apolipoproteins (apoA-I and apoB). Ratios of lipids and apolipoproteins were calculated and their associations with BMI, WC, and HbA1c levels were analysed.Results: Our investigation showed increases in most fasting and postprandial lipid parameters according to BMI and WC. In men, postprandial HDL-c and TG levels were significantly higher (pB0.05) in overweight and obese patients, respectively, as well as in patients with abdominal obesity. Contrariwise, postprandial TC levels were significantly higher (pB0.01) in overweight and abdominal obese women. However, elevations of apoA-I and apoB levels were according to BMI and WC in both genders. There was a strong influence of BMI,WC, and HbA1c levels on the apoB/apoA-I ratio compared to traditional fasting and postprandial lipid ratios in both men and women. The apoB/apoA-I ratio was more correlated with postprandial TC/HDL and LDL-c/HDL-c ratios in men and with postprandial TG/HDL-c in women.Conclusion: The apoB/apoA-I ratio is helpful in assessing metabolic risk caused by overall obesity, abdominal obesity and impaired glycaemia in type 2 diabetic patients.Keywords: type 2 diabetes; body mass index; waist circumference; HbA1c; metabolic contro
Pattern of second primary malignancies in thyroid cancer patients
Many factors, including relatively young age of thyroid cancer diagnoses and improved survival, have led to increased concerns about the occurrence of second primary malignancies. This paper describes the pattern of occurrence of second primary malignancies in patients who were treated for malignant thyroid neoplasms in an Indian hospital. There were 21 affected patients of the approximately 4500 seen over 25 years. Most of the second primary cancers are solid tumors, and when nonthyroid cancers are the second tumors, ductal carcinoma of the female breast is the most common. Most of these tumors have very short detection intervals (including synchronous occurrences), suggesting that therapy with internal radiation was not contributory to the tumor development. Whenthyroid malignancies were the second primary cancers, they usually follow radiotherapy to the head and neck region for treatment of the first primary tumor and tend to be of aggressive histologic types than the common welldifferentiated thyroid carcinomas.Key words: Radiation, radiotherapy, second malignancies, thyroid cance
Electron localization and possible phase separation in the absence of a charge density wave in single-phase 1T-VS
We report on a systematic study of the structural, magnetic and transport
properties of high-purity 1T-VS powder samples prepared under high
pressure. The results differ notably from those previously obtained by
de-intercalating Li from LiVS. First, no Charge Density Wave (CDW) is found
by transmission electron microscopy down to 94 K. Though, \textit{ab initio}
phonon calculations unveil a latent CDW instability driven by an acoustic
phonon softening at the wave vector (0.21,0.21,0)
previously reported in de-intercalated samples. A further indication of latent
lattice instability is given by an anomalous expansion of the V-S bond distance
at low temperature. Second, infrared optical absorption and electrical
resistivity measurements give evidence of non metallic properties, consistent
with the observation of no CDW phase. On the other hand, magnetic
susceptibility and NMR data suggest the coexistence of localized moments with
metallic carriers, in agreement with \textit{ab initio} band structure
calculations. This discrepancy is reconciled by a picture of electron
localization induced by disorder or electronic correlations leading to a phase
separation of metallic and non-metallic domains in the nm scale. We conclude
that 1T-VS is at the verge of a CDW transition and suggest that residual
electronic doping in Li de-intercalated samples stabilizes a uniform CDW phase
with metallic properties.Comment: 22 pages, 10 Figures. Full resolution pictures available at
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.89.23512
Vectorial Formalism of Polyphase Synchronous Machine with Permanents Magnets
- This paper presents a mathematical model that transforms the real machine to fictitious machines and our goal is to simulate these and see the behavior of these machines in load. The polyphase machines are developed mainly in the field of variable speed drives of high power because increasing the number of phases on the one hand allows to reduce the dimensions of the components in power modulators energy and secondly to improve the operating safety. By a vector approach (vector space), it is possible to find a set of single-phase machine and / or two-phase fictitious equivalent to polyphase synchronous machine. These fictitious machines are coupled electrically and mechanically but decoupled magnetically. This approach leads to introduce the concept of the equivalent machine (multimachine multiconverter system MMS) which aims to analyze systems composed of multiple machines (or multiple converters) in electric drives. A first classification multimachine multiconverter system follows naturally from MMS formalism. We present an example of a pentaphase (polyphase) synchronous machine for a simulation and study the behavior of the machine load
Serum IL-33, a new marker predicting response to rituximab in rheumatoid arthritis
Background. Recent works have suggested a possible link between IL-33 and B-cell biology. We aimed to study in different cohorts and with an accurate ELISA assay the possible association between serum IL-33 detection and response to rituximab (RTX) in rheumatoid arthritis (RA) patients. Method. Serum IL-33, rheumatoid factor (RF), anti-citrullinated cyclic peptide antibodies (anti-CCP), high serum IgG level were assessed in 111 RA patients receiving a first course of 2 grams RTX (cohort 1) in an observational study and in 74 RA patients treated with the same schedule in routine care (cohort 2). Uni and multivariate analyzes identified factors associated with a European League Against Rheumatism response at 24 weeks. Results. At week 24, 84/111 (76%) and 54/74 (73%) patients reached EULAR response in the cohorts 1 and 2, respectively. Serum IL-33 was detectable in only 33,5% of the patients. In the combined cohorts, presence of RF or anti-CCP (OR 3.27, 95%CI [1.13-9.46]; p=0.03), high serum IgG (OR 2.32, 95%CI [1.01-5.33]; p=0.048) and detectable serum IL-33 (OR 2.40, 95%CI [1.01-5.72]; p=0.047) were all associated with RTX response in multivariate analysis. Combination of these 3 factors increased the likelihood to response to RTX. When serum IL-33 detection was added to seropositivity and serum IgG level, 100% of the patients with the 3 risk factors (corresponding to 9% of the population) responded to RTX (OR versus patients with none of the 3 risk factors = 29.61; 95% CI [1.30-674.79] p=0.034) Conclusion. Detectable serum IL-33 may predict clinical response to RTX, independently of and synergistically with autoantibodies and serum IgG level
Baseline total metabolic tumor volume is prognostic for refractoriness to Iimunochemotherapy in DLBCL: results from GOYA
Introduction
A good response to initial therapy is key to maximizing survival in patients with diffuse large B-cell lymphoma (DLBCL), but patients with chemorefractory disease and early progression have poor outcomes.
Patients and Methods
Data from the GOYA study in patients with DLBCL who received first-line rituximab or obinutuzumab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) were analyzed. Positron emission tomography/computed tomography (PET/CT)-derived characteristics associated with total metabolic tumor volume (TMTV) and clinical risk factors for primary chemorefractory disease and disease progression within 12 months (POD12) were explored.
Results
Of those patients fulfilling the criteria for analysis, 108/1126 (10%) were primary chemorefractory and 147/1106 (13%) had POD12. Primary chemorefractory and POD12 status were strongly associated with reduced overall survival. After multivariable analysis of clinical and imaging-based risk factors by backward elimination, only very high TMTV (quartile [Q] 1 vs. Q4 odds ratio [OR]: 0.45; P = .006) and serum albumin levels (low vs. normal OR of 1.86; P = .004) were associated with primary chemorefractoriness. After additionally accounting for BCL2/MYC translocation in a subset of patients, TMTV and BCL2/MYC double-hit status remained as significant predictors of primary chemorefractoriness (Q1 vs. Q4 OR: 0.32, P = .01 and double-hit vs. no-hit OR of 4.47, P = .02, respectively). Risk factors including very high TMTV, high sum of the product of the longest diameters (SPD), geographic region (Asia), short time since diagnosis, extranodal involvement and low serum albumin were retained for POD12.
Conclusion
PET-derived TMTV has prognostic value in identifying patients at risk of early treatment failure
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