363 research outputs found
The thermal dehydration of magnesium sulfate hexahydrate (MgSO3.6H2O) and magnesium sulfite trihydrate (MgSO3.3H2O)
The thermal dehydration of MgSO3.3H2O and MgSO3.6H2O have been studied by differential thermal analysis, differential scanning calorimetry and thermal gravimetric analysis.
Similar studies by other groups led to contradictory conclusions. In this investigation, these results were reconciled and it was concluded that MgSO3.6H2O, under equilibrium conditions, dehydrates in two steps through the intermediate formation of MgSO3.3H2O.
One consequence of this work is the development of a simple analytical procedure, using TGA, for the quantitative determination of both hydrates in mixtures and in the presence of thermally inactive material
DNA ploidy and proliferative activity (S-phase) in childhood soft-tissue sarcomas: their value as prognostic indicators.
The value of DNA ploidy as a prognostic indicator is well established in many cancers, but recent studies in childhood rhabdomyosarcoma (RMS) have been contradictory. In a retrospective study of 128 cases of soft-tissue sarcoma (STS) diagnosed since 1980, the prognostic value of clinical, histological and flow cytometric parameters was compared, using univariate and multivariate methods. Eighty-one RMSs, 18 extraosseous Ewing's (EOE)/peripheral neuroectodermal tumours (PNETs) and 29 other non-RMS STSs were histologically and clinically reviewed. Five year actuarial survival was 63.4% for all STSs and 69.4% for RMSs. Paraffin-embedded tissue blocks were available for flow cytometry in 90 cases. Of the RMSs, 65.5% were aneuploid [DNA index (DI) > 1.1] compared with 23% of the EOE/PNETs and 31% of non-RMS STSs. Median S-phase was also significantly higher in RMSs (17.0%) than in other STSs (10.8%) (P = 0.0023). Univariate analysis in RMSs showed that stage, ploidy status, S-phase, site and tumour size all had a significant impact on survival. In multivariate analysis of 59 cases of RMS, one clinical and two flow cytometric parameters were independently associated with poor prognosis. These were stage (IV), nonhyperdiploidy (DI < 1.10 and > 1.8) and a high rate of proliferative activity (S-phase > 14.0%). These results confirm that ploidy and S-phase are important new prognostic indicators in rhabdomyosarcoma
Sexually transmitted infections case notification rates in the Kingdom of Saudi Arabia, 2005–2012
Introduction: Sexually transmitted infections (STIs) are major public health concerns around the world. This study describes the epidemiology of reported STI cases from 2005 to 2012 in the Kingdom of Saudi Arabia.
Methodology: The annual registry was the main source of data as reported by healthcare providers. Case definitions were based on positive human immunodeficiency virus (HIV) antibodies detectable by enzyme-linked immunosorbent assay (ELISA) and confirmed by western blot test for HIV cases. The definitions of other STIs were based on published Centers for Disease Control and Prevention (CDC) definitions.
Results: During the study period, 68,886 new cases were reported, with nongonococcal urethritis being the highest STI (25.4) per 100,000 population (25.4), followed by trichomoniasis (9.1), HIV (7), human papillomavirus (HPV) infection (2.9), and syphilis (1.3). The cases included nongonococcal urethritis (n = 35,613; 51.7%), trichomoniasis (n = 12,679; 18.4%), gonococcal urethritis (n = 3,006; 4.4%), syphilis (n = 1,769; 2.6%), HIV (n = 9,843; 14.3%), genital warts (n = 4,018; 5.8%), genital herpes (n = 1,508; 2.2%), and chancroid (n = 450; 0.7%). Saudi contribution to HIV cases increased from 28.9% in the preceding decade to 43.5% in the current study.
Conclusions: Nongonococcal urethritis, trichomoniasis, and HIV were the most commonly reported STIs in the Kingdom of Saudi Arabia
A Third Approach to Gene Prediction Suggests Thousands of Additional Human Transcribed Regions
The identification and characterization of the complete ensemble of genes is a main goal of deciphering the digital information stored in the human genome. Many algorithms for computational gene prediction have been described, ultimately derived from two basic concepts: (1) modeling gene structure and (2) recognizing sequence similarity. Successful hybrid methods combining these two concepts have also been developed. We present a third orthogonal approach to gene prediction, based on detecting the genomic signatures of transcription, accumulated over evolutionary time. We discuss four algorithms based on this third concept: Greens and CHOWDER, which quantify mutational strand biases caused by transcription-coupled DNA repair, and ROAST and PASTA, which are based on strand-specific selection against polyadenylation signals. We combined these algorithms into an integrated method called FEAST, which we used to predict the location and orientation of thousands of putative transcription units not overlapping known genes. Many of the newly predicted transcriptional units do not appear to code for proteins. The new algorithms are particularly apt at detecting genes with long introns and lacking sequence conservation. They therefore complement existing gene prediction methods and will help identify functional transcripts within many apparent “genomic deserts.
A developed IoT technique and P&O-MPPT to enhance the output power of solar cell systems
Abstract- Given the urgent need for continuous development in solar cell systems to increase their efficiency, in this study, a developed IoT technique was built to monitor the solar irradiance fluctuation around the solar cell systems, and a Perturbation and observation algorithm (P&O) was developed to increase the output power from the PV systems. In order to save energy, the IoT technique has been supported with a light-dependent resistor to operate and shut down with sunlight. The whole IoT technique was fed from the PV system to save energy and avoid a power outage. The measured solar irradiance profile was displayed online on the ubidots. Then, the measured solar power irradiance through IoT was introduced to the MATLAB simulation program to study the performance of the proposed P&O maximum power point tracking (P&O-MPPT) algorithm. The P&O-MPPT algorithm was used to control the voltage and current by continuous adjustments in the duty cycle to improve the output power of the studied solar system. The obtained results showed the efficiency of the monitoring system based on IoT in recording changes in solar radiation and the improvement in the output power as a result of the developed P&O-MPPT system
A developed IoT technique and P&O-MPPT to enhance the output power of solar cell systems
Abstract- Given the urgent need for continuous development in solar cell systems to increase their efficiency, in this study, a developed IoT technique was built to monitor the solar irradiance fluctuation around the solar cell systems, and a Perturbation and observation algorithm (P&O) was developed to increase the output power from the PV systems. In order to save energy, the IoT technique has been supported with a light-dependent resistor to operate and shut down with sunlight. The whole IoT technique was fed from the PV system to save energy and avoid a power outage. The measured solar irradiance profile was displayed online on the ubidots. Then, the measured solar power irradiance through IoT was introduced to the MATLAB simulation program to study the performance of the proposed P&O maximum power point tracking (P&O-MPPT) algorithm. The P&O-MPPT algorithm was used to control the voltage and current by continuous adjustments in the duty cycle to improve the output power of the studied solar system. The obtained results showed the efficiency of the monitoring system based on IoT in recording changes in solar radiation and the improvement in the output power as a result of the developed P&O-MPPT system
Aluminium and lead abnormalities in children on haemodialysis: relationship with some medications
Adiponectin: an adipocyte-derived hormone, and its gene encoding in children with chronic kidney disease
BACKGROUND: The prevalence of cardiovascular disease (CVD) and inflammation is high in patients with chronic kidney disease (CKD). Adiponectin (ADPN) is an adipocytokine that may have significant anti-inflammatory and anti-atherosclerotic effects. Low adiponectin levels have previously been found in patients with high risk for CVD. METHODS: On seventy eight advanced CKD (stages 4 and 5) pediatric patients undergoing maintenance hemodialysis( MHD) or conservative treatment (CT) the following parameters were studied: body mass index, left ventricular mass index(LVMI), serum adiponectin , cholesterol, HDL-cholesterol, high sensitivity C-reactive protein (hs CRP),interleukin 6(IL6) and single-nucleotide polymorphisms (SNPs) in the ADIPOQ gene at positions 45, and 276. Seventy age-and gender-matched healthy subjects served as control subjects. RESULTS: Markedly (P = 0.01) elevated plasma adiponectin levels were observed in CKD patients, especially CT patients, compared to control subjects. The wild type of ADIPOQ 45T > G (T) allele is the main gene for patients and controls. MHD and CT patients had significantly higher frequency of the TT genotypes of +276G > T gene (P = 0.04) compared with control subjects. A significant positive correlation was observed between plasma adiponectin and IL6 level, whereas negative correlations were found between adiponectin level, cholesterol, HDL cholesterol and hs CRP. In a stepwise backward multiple regression model only IL6 (P = 0.001) was independently associated with plasma adiponectin levels. The adiponectin gene the 276 GT+TT genotypes were associated with a higher level of adiponectin . CONCLUSIONS: The present study demonstrated that ADPN is related to several metabolic and inflammatory CV risk factors in a manner consistent with the hypothesis that this protein might have a protective role against these factors. We observed an association between the +276G>T SNP in the adiponectin gene and CKD in children. Genetic variation of +276 gene seemed to have a positive impact on circulating adiponectin levels in CKD patients
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