3,157 research outputs found
Computer Modeling of Platinum Reforming Reactors
Usually, the reformate that is leaving any stage of the platinum reforming reactors in terms of hydrocarbon composition is assessed by laboratory analysis. The ideal composition can only be tested through theoretical means, which in most cases is avoided because of long computation time involved. This paper, instead of using a theoretical approach has considered a computer model as means of assessing the reformate composition for three-stage fixed bed reactors in platforming unit. This is done by identifying many possible hydrocarbon transformation reactions that are peculiar to the process unit, identify the operating data, mathematically model and programme their reaction rate equations using QBasic language. In this article outlet product rate of 311363.59 kg/hr in the first, second and third reactor was obtained by modeling 275 m3/h inlet feed rate of Bayton Rouge Naphtha in the Kaduna Refinery. A manual or theoretical calculated value of 311145.22 kg/hr of outlet product rate was obtained showing a slight deviation of 0.9%. The authors are convinced that the written computer model could be applied in the process unit because it is accurate and less time consuming
Ultrafiltration for acute decompensated cardiac failure: A systematic review and meta-analysis
Background
Ultrafiltration is a method used to achieve diuresis in acute decompensated heart failure (ADHF) when there is diuretic resistance, but its efficacy in other settings is unclear. We therefore conducted a systematic review and meta-analysis to evaluate the use of ultrafiltration in ADHF.
Methods
We searched MEDLINE and EMBASE for studies that evaluated outcomes following filtration compared to diuretic therapy in ADHF. The outcomes of interest were body weight change, change in renal function, length of stay, frequency of rehospitalization, mortality and dependence on dialysis. We performed random effects meta-analyses to pool studies that evaluated the desired outcomes and assessed statistical heterogeneity using the I2 statistic.
Results
A total of 10 trials with 857 participants (mean age 68 years, 71% male) compared filtration to usual diuretic care in ADHF. Nine studies evaluated weight change following filtration and the pooled results suggest a decline in mean body weight − 1.8; 95% CI, − 4.68 to 0.97 kg. Pooled results showed no difference between the filtration and diuretic group in change in creatinine or estimated glomerular filtration rate. The pooled results suggest longer hospital stay with filtration (mean difference, 3.70; 95% CI, − 3.39 to 10.80 days) and a reduction in heart failure hospitalization (RR, 0.71; 95% CI, 0.51–1.00) and all-cause rehospitalization (RR, 0.89; 95% CI, 0.43–1.86) compared to the diuretic group. Filtration was associated with a non-significant greater risk of death compared to diuretic use (RR, 1.08; 95% CI, 0.77–1.52)
Balancing carrots and sticks: incentives for sustainable hilsa fishery management in Bangladesh
Mihir Kanti Majumder, Md Mokammel Hossain, Atiq Rahman, Belayet Hussei
Evaluation of early and late presentation of patients with ocular mucous membrane pemphigoid to two major tertiary referral hospitals in the United Kingdom
PURPOSE: Ocular mucous membrane pemphigoid (OcMMP) is a sight-threatening autoimmune disease in which referral to specialists units for further management is a common practise. This study aims to describe referral patterns, disease phenotype and management strategies in patients who present with either early or established disease to two large tertiary care hospitals in the United Kingdom.\ud
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PATIENTS AND METHODS: In all, 54 consecutive patients with a documented history of OcMMP were followed for 24 months. Two groups were defined: (i) early-onset disease (EOD:<3 years, n=26, 51 eyes) and (ii) established disease (EstD:>5 years, n=24, 48 eyes). Data were captured at first clinic visit, and at 12 and 24 months follow-up. Information regarding duration, activity and stage of disease, visual acuity (VA), therapeutic strategies and clinical outcome were analysed.\ud
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RESULTS: Patients with EOD were younger and had more severe conjunctival inflammation (76% of inflamed eyes) than the EstD group, who had poorer VA (26.7%=VA<3/60, P<0.01) and more advanced disease. Although 40% of patients were on existing immunosuppression, 48% required initiation or switch to more potent immunotherapy. In all, 28% (14) were referred back to the originating hospitals for continued care. Although inflammation had resolved in 78% (60/77) at 12 months, persistence of inflammation and progression did not differ between the two phenotypes. Importantly, 42% demonstrated disease progression in the absence of clinically detectable inflammation.\ud
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CONCLUSIONS: These data highlight that irrespective of OcMMP phenotype, initiation or escalation of potent immunosuppression is required at tertiary hospitals. Moreover, the conjunctival scarring progresses even when the eye remains clinically quiescent. Early referral to tertiary centres is recommended to optimise immunosuppression and limit long-term ocular damage.\ud
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Gibbsian Method for the Self-Optimization of Cellular Networks
In this work, we propose and analyze a class of distributed algorithms
performing the joint optimization of radio resources in heterogeneous cellular
networks made of a juxtaposition of macro and small cells. Within this context,
it is essential to use algorithms able to simultaneously solve the problems of
channel selection, user association and power control. In such networks, the
unpredictability of the cell and user patterns also requires distributed
optimization schemes. The proposed method is inspired from statistical physics
and based on the Gibbs sampler. It does not require the concavity/convexity,
monotonicity or duality properties common to classical optimization problems.
Besides, it supports discrete optimization which is especially useful to
practical systems. We show that it can be implemented in a fully distributed
way and nevertheless achieves system-wide optimality. We use simulation to
compare this solution to today's default operational methods in terms of both
throughput and energy consumption. Finally, we address concrete issues for the
implementation of this solution and analyze the overhead traffic required
within the framework of 3GPP and femtocell standards.Comment: 25 pages, 9 figures, to appear in EURASIP Journal on Wireless
Communications and Networking 201
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Visualizing the Spatial Relationship of the Genome with the Nuclear Envelope Using Fluorescence In Situ Hybridization
The genome has a special relationship with the nuclear envelope in cells. Much of the genome is anchored at the nuclear periphery, tethered by chromatin binding proteins such nuclear lamins and other integral membrane proteins. Even though there are global assays such as DAM-ID or ChIP to assess what parts of the genome are associated with the nuclear envelope, it is also essential to be able to visualize regions of the genome in order to reveal their individual relationships with nuclear structures in single cells. This is executed by fluorescence in situ hybridization (FISH) in 2-dimensional flattened nuclei (2D-FISH) or 3-dimensionally preserved cells (3D-FISH) in combination with indirect immunofluorescence to reveal structural proteins. This chapter explains the protocols for 2D- and 3D-FISH in combination with indirect immunofluorescence and discusses options for image capture and analysis. Due to the nuclear envelope proteins being part of the non-extractable nucleoskeleton, we also describe how to prepare DNA halos through salt extraction and how they can be used to study genome behavior and association when combined with 2D-FISH.SPARKs children’s charity for funding CSC; Brunel University London Progeria Research Fund; The Gordon Memorial Trust; EURO-laminopathies consortium FP6
A genome-wide association study to identify genetic markers associated with endometrial cancer grade
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Evaluation of the zucker diabetic fatty (ZDF) rat as a model for human disease based on urinary peptidomic profiles
Representative animal models for diabetes-associated vascular complications are extremely relevant in assessing potential therapeutic drugs. While several rodent models for type 2 diabetes (T2D) are available, their relevance in recapitulating renal and cardiovascular features of diabetes in man is not entirely clear. Here we evaluate at the molecular level the similarity between Zucker diabetic fatty (ZDF) rats, as a model of T2D-associated vascular complications, and human disease by urinary proteome analysis. Urine analysis of ZDF rats at early and late stages of disease compared to age- matched LEAN rats identified 180 peptides as potentially associated with diabetes complications. Overlaps with human chronic kidney disease (CKD) and cardiovascular disease (CVD) biomarkers were observed, corresponding to proteins marking kidney damage (eg albumin, alpha-1 antitrypsin) or related to disease development (collagen). Concordance in regulation of these peptides in rats versus humans was more pronounced in the CVD compared to the CKD panels. In addition, disease-associated predicted protease activities in ZDF rats showed higher similarities to the predicted activities in human CVD. Based on urinary peptidomic analysis, the ZDF rat model displays similarity to human CVD but might not be the most appropriate model to display human CKD on a molecular level
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