491 research outputs found
Sorption of Eu(III) on Attapulgite Studied by Batch, XPS and EXAFS Techniques.
The effects of pH, ionic strength and temperature on sorption of Eu(III) on attapulgite were investigated in the presence and absence of fulvic acid (FA) and humic acid (HA). The results indicated that the sorption of Eu(III) on attapulgite was strongly dependent on pH and ionic strength, and independent of temperature. In the presence of FA/HA, Eu(III) sorption was enhanced at pH 7. The X-ray photoelectron spectroscopy (XPS) analysis suggested that the sorption of Eu(III) might be expressed as ≡X3Eu0 ≡SwOHEu3+ and ≡SOEu-OOC-/HA in the ternary Eu/HA/attapulgite system. The extended X-ray absorption fine structure (EXAFS) analysis of Eu-HA complexes indicated that the distances of d(Eu-O) decreased from 2.451 to 2.360 Å with increasing pH from 1.76 to 9.50, whereas the coordination number (N) decreased from ~9.94 to ~8.56. Different complexation species were also found for the different addition sequences of HA and Eu(III) to attapulgite suspension. The results are important to understand the influence of humic substances on Eu(III) behavior in the natural environment
Resequencing And Nucleotide Variation Of Sucrose Synthase (Nmsusy1) Gene In A Tropical Timber Tree Neolamarckia Macrophylla
Sucrose synthase (SuSy) is a key enzyme that catalyses the reversible synthesis and degradation of sucrose. It provides greater impact in
regulating the photosynthetic processes and environmental stresses in plants. Thus, the nucleotide variation of partial NmSusy1 genomic DNAs (750 bp)
generated through PCR amplification was examined in this study, and this followed by resequencing from 15 selected Neolamarckia macrophylla clones.
The consensus sequences were aligned to detect the presence of single nucleotide polymorphisms (SNPs). In total, five SNPs were detected at
nucleotide 1, 2, 34, 35 and 397. Of these, four SNPs were located at the predicted coding region while one SNP was located at the predicted non-coding
region. Interestingly, one single base pair InDel polymorphism was also detected at nucleotide 17. On average, one SNP at every 150 bp was detected
based on the 15 NmSusy1 sequences. There was one non-synonymous mutation detected, whereby amino acid glutamic acid (E) was replaced by
arginine (R) in one of the 15 samples tested. This non-synonymous SNP might change the structural, functional or biochemical properties of the enzyme
being produced and therefore possibly lead to changes in phenotypic characteristic of the trees. Overall, this study has demonstrated that resequencing
is an effective technique for classifying molecular diversity or nucleotide variation in the Susy gene of N. macrophylla. Those SNPs, once validated,
could potentially be used as a tool in marker-assisted selection (MAS) that enables more precise and accurate in the selection and prediction of yield or
performance at the early developmental stages, such as at the seedling stage
Optimal Biomethane Injection into Natural Gas Grid – Biogas from Palm Oil Mill Effluent (POME) in Malaysia
The Malaysian government aims to facilitate the renewable energy (RE) sector by introducing the National Renewable Energy Policy and Action Plan during 2010. 4,000 MW of installed RE capacity is targeted by 2030, with 410 MW biogas capacity. Palm oil mill effluent (POME), agro-based industries and farming industries are identified as potential sources of biogas. It was studied that more than 500 kt of biomethane could be produced yearly if all the POME is treated anaerobically. The utilization of biomethane has remained unexplored for its injection into natural gas grid. This papers aims to identify the potential of POME biomethane injection into natural gas grid by using the BeWhere model, a techno-economic spatial explicit model. The locations, capacity and technology of biogas refinery plants will be identified based on cost minimization of the full supply chain of biogas production. The result shows that 135 - 227 biogas plants were selected, supplying 40% - 67% residential fossil gas demand, under different carbon price implementation and fossil gas subsidy scenarios
Nano Fe3O4-activated carbon composites for aqueous supercapacitors
In this study, a symmetric supercapacitor has been fabricated by adopting the nanostructured iron oxide (Fe3O4)-activated carbon (AC) composite as the core electrode materials. The composite electrodes were prepared via a facile mechanical mixing process and PTFE polymeric solution has been used as the electrode material binder. Structural analysis of the nanocomposite electrodes were characterized by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis. The electrochemical performances of the prepared supercapacitor were studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in 1.0 M Na2SO3 and 1.0 M Na2SO4 aqueous solutions, respectively. The experimental results showed that the highest specific capacitance of 43 F/g is achieved with a fairly low Fe3O4 nanomaterials loading (4 wt. %) in 1 M Na2SO3. It is clear that the low concentration of nanostructured Fe3O4 has improved the capacitive performance of the composite via pseudocapacitance charge storage mechanism as well as the enhancement on the specific surface areas of the electrode. However, further increasing of the Fe3O4 content in the electrode is found to distort the capacitive performance and deteriorate the specific surface area of the electrode, mainly due to the aggregation of the Fe3O4 particles within the composite. Additionally, the CV results showed that the Fe3O4/AC nanocomposite electrode in Na2SO3 electrolyte exhibits a better charge storage performance if compared with Na2SO4 solution. It is believed that Fe3O4 nanoparticles can provide favourable surface adsorption sites for sulphite (SO32-) anions which act as catalysts for subsequent redox and intercalation reactions
Physiologie appliquee, nutrition et metabolisme
This study examined whether expectancy of ergogenicity of a commonly used nutritional supplement (sodium bicarbonate; NaHCO3) influenced subsequent high-intensity cycling capacity. Eight recreationally active males (age, 21 ± 1 years; body mass, 75 ± 8 kg; height, 178 ± 4 cm; WPEAK = 205 ± 22 W) performed a graded incremental test to assess peak power output (WPEAK), one familiarisation trial and two experimental trials. Experimental trials consisted of cycling at 100% WPEAK to volitional exhaustion (TLIM) 60 min after ingesting either a placebo (PLA: 0.1 g·kg(-1) sodium chloride (NaCl), 4 mL·kg(-1) tap water, and 1 mL·kg(-1) squash) or a sham placebo (SHAM: 0.1 g·kg(-1) NaCl, 4 mL·kg(-1) carbonated water, and 1 mL·kg(-1) squash). SHAM aimed to replicate the previously reported symptoms of gut fullness (GF) and abdominal discomfort (AD) associated with NaHCO3 ingestion. Treatments were administered double blind and accompanied by written scripts designed to remain neutral (PLA) or induce expectancy of ergogenicity (SHAM). After SHAM mean TLIM increased by 9.5% compared to PLA (461 ± 148 s versus 421 ± 150 s; P = 0.048, d = 0.3). Ratings of GF and AD were mild but ~1 unit higher post-ingestion for SHAM. After 3 min TLIM overall ratings of perceived exertion were 1.4 ± 1.3 units lower for SHAM compared to PLA (P = 0.020, d = 0.6). There were no differences between treatments for blood lactate, blood glucose, or heart rate. In summary, ergogenicity after NaHCO3 ingestion may be influenced by expectancy, which mediates perception of effort during subsequent exercise. The observed ergogenicity with SHAM did not affect our measures of cardiorespiratory physiology or metabolic flux.University of Derby Departmental Teaching Budge
Defining factors associated with high-quality surgery following radical cystectomy : analysis of the British Association of Urological Surgeons cystectomy audit
Background
Radical cystectomy (RC) is associated with high morbidity.
Objective
To evaluate healthcare and surgical factors associated with high-quality RC surgery.
Design, setting, and participants
Patients within the prospective British Association of Urological Surgeons (BAUS) registry between 2014 and 2017 were included in this study.
Outcome measurements and statistical analysis
High-quality surgery was defined using pathological (absence of positive surgical margins and a minimum of a level I lymph node dissection template with a minimum yield of ten or more lymph nodes), recovery (length of stay ≤10 d), and technical (intraoperative blood loss <500 ml for open and <300 ml for minimally invasive RC) variables. A multilevel hierarchical mixed-effect logistic regression model was utilised to determine the factors associated with the receipt of high-quality surgery and index admission mortality.
Results and limitations
A total of 4654 patients with a median age of 70.0 yr underwent RC by 152 surgeons at 78 UK hospitals. The median surgeon and hospital operating volumes were 23.0 and 47.0 cases, respectively. A total of 914 patients (19.6%) received high-quality surgery. The minimum annual surgeon volume and hospital volume of ≥20 RCs/surgeon/yr and ≥68 RCs/hospital/yr, respectively, were the thresholds determined to achieve better rates of high-quality RC. The mixed-effect logistic regression model found that recent surgery (odds ratio [OR]: 1.22, 95% confidence interval [CI]: 1.11–1.34, p < 0.001), laparoscopic/robotic RC (OR: 1.85, 95% CI: 1.45–2.37, p < 0.001), and higher annual surgeon operating volume (23.1–33.0 cases [OR: 1.54, 95% CI: 1.16–2.05, p = 0.003]; ≥33.1 cases [OR: 1.64, 95% CI: 1.18–2.29, p = 0.003]) were independently associated with high-quality surgery. High-quality surgery was an independent predictor of lower index admission mortality (OR: 0.38, 95% CI: 0.16–0.87, p = 0.021).
Conclusions
We report that annual surgeon operating volume and use of minimally invasive RC were predictors of high-quality surgery. Patients receiving high-quality surgery were independently associated with lower index admission mortality. Our results support the role of centralisation of complex oncology and implementation of a quality assurance programme to improve the delivery of care.
Patient summary
In this registry study of patients treated with surgical excision of the urinary bladder for bladder cancer, we report that patients treated by a surgeon with a higher annual operative volume and a minimally invasive approach were associated with the receipt of high-quality surgery. Patients treated with high-quality surgery were more likely to be discharged alive following surgery
Osteoprotegerin: A Novel Secreted Protein Involved in the Regulation of Bone Density
AbstractA novel secreted glycoprotein that regulates bone resorption has been identified. The protein, termed Osteoprotegerin (OPG), is a novel member of the TNF receptor superfamily. In vivo, hepatic expression of OPG in transgenic mice results in a profound yet nonlethal osteopetrosis, coincident with a decrease in later stages of osteoclast differentiation. These same effects are observed upon administration of recombinant OPG into normal mice. In vitro, osteoclast differentiation from precursor cells is blocked in a dose-dependent manner by recombinant OPG. Furthermore, OPG blocks ovariectomy-associated bone loss in rats. These data show that OPG can act as a soluble factor in the regulation of bone mass and imply a utility for OPG in the treatment of osteoporosis associated with increased osteoclast activity
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