Temporary worsening of kidney function following aortic reconstructive surgery.

INTRODUCTION Little is known about the incidence of temporary kidney dysfunction following major vascular surgeries. We aimed to assess the frequency of temporary decreased kidney function following aortic surgeries. MATERIALS AND METHODS In a retrospective study, we assessed 108 hospital records of the patients who had undergone elective open abdominal surgery of aortic aneurysm. Preoperative and postoperative (days 1, 2, and 3) data on estimated glomerular filtration rate (GFR) were collected and evaluated in relation to the patients' clinical characteristics and outcomes. A decline greater than 10% in GFR on day 1 or 2, and then, an increase of GFR to a level of maximum 10% below the baseline value on the third postoperative day was considered as temporary worsening of kidney function. Postoperative alterations of GFR not greater than 10% in relation to the baseline were considered as improved or unchanged kidney function. Two patients with persistent decrease in GFR were excluded. RESULTS Temporary worsening of kidney function was seen in 25 patients (23.6%). Short-term mortality rate was 44.0% in this group of patients, while it was 17.3% in those without decreased GFR (P = .006). According to the regression analysis, the only predictor of mortality was temporary worsening of kidney function, with a hazard ratio of 4.03 (95% confidence interval, 1.44 to 11.31; P = .008). CONCLUSIONS Nearly 1 out of 4 aortic surgeries results in kidney dysfunction. Albeit temporary in most cases, it seems to be associated with a higher short-term mortality rate

Fullerene-based delivery systems

With the development of new drugs, there have been many attempts to explore innovative delivery routes. Targeted delivery systems are a desired solution designed to overcome the deficiency of routine methods. To transform this idea into reality, a wide range of nanoparticles has been proposed and studied. These nanoparticles should interact well with biological environments and pass through cell membranes to deliver therapeutic molecules. One of the pioneer classes of carbon-based nanoparticles for targeted delivery is the fullerenes. Fullerenes have a unique structure and possess suitable properties for interaction with the cellular environment. This short review concentrates on newly developed fullerene derivatives and their potential as advanced delivery systems for pharmaceutical applications. © 2019 Elsevier Lt

Studies on the stability of population equilibrium of the diamondback moth (Plutella xylostella (Lep.: Plutellidae)) using perturbation method

Nowadays, a basic understanding of population biology is necessary to establish ecological strategies of pest management. In the present study, the population behavior of the diamondback moth after a perturbation was examined. For this purpose, a long-term experiment with three treatments (control, a perturbation using density reduction and a perturbation using density increase) was performed. The experiment was started with 10 pairs of adult moths in ventilated cages under the standard constant environment. The experiment was continued for 10 generations. After five generations, the perturbation was applied and each treatment was replicated 10 times. Adults and larvae were fed with honey solution (20%) and Chinese cabbage, respectively. The population trend and stability were monitored by weekly census counts of live adults, and the data used as a measure of abundance for the population dynamics. The results showed that the populations of the diamondback moth persisted at equilibrial levels when there was no perturbation. On the contrary, when the populations were perturbed using density reduction, the population equilibrium was shifted to a lower level; in this situation perturbations using sustainable strategies, such as the release of natural enemies or the application of microbial insecticides, may set the equilibrium beneath economic injury threshold. While, a perturbation using density increase can cause instability of population equilibrium toward a decreasing trend that may drive the population to extinction. The causes and effects of the findings in relation with the moth life history, resource competition and its ecological consequences on the population behavior were discussed

Nanotechnology and global energy demand: challenges and prospects for a paradigm shift in the oil and gas industry.

The exploitation of new hydrocarbon discoveries in meeting the present global energy demand is a function of the availability and application of new technologies. The relevance of new technologies is borne out of the complex subsurface architecture and conditions of offshore petroleum plays. Conventional techniques, from drilling to production, for exploiting these discoveries may require adaption for such subsurface conditions as they fail under conditions of high pressure and high temperature. The oil and gas industry over the past decades has witnessed increased research into the use of nanotechnology with great promise for drilling operations, enhanced oil recovery, reservoir characterization, production, etc. The prospect for a paradigm shift towards the application of nanotechnology in the oil and gas industry is constrained by evolving challenges with its progression. This paper gave a review of developments from nano-research in the oil and gas industry, challenges and recommendations

Synthesising executable gene regulatory networks in haematopoiesis from single-cell gene expression data

A fundamental challenge in biology is to understand the complex gene regulatory networks which control tissue development in the mammalian embryo, and maintain homoeostasis in the adult. The cell fate decisions underlying these processes are ultimately made at the level of individual cells. Recent experimental advances in biology allow researchers to obtain gene expression profiles at single-cell resolution over thousands of cells at once. These single-cell measurements provide snapshots of the states of the cells that make up a tissue, instead of the population-level averages provided by conventional high-throughput experiments. The aim of this PhD was to investigate the possibility of using this new high resolution data to reconstruct mechanistic computational models of gene regulatory networks. In this thesis I introduce the idea of viewing single-cell gene expression profiles as states of an asynchronous Boolean network, and frame model inference as the problem of reconstructing a Boolean network from its state space. I then give a scalable algorithm to solve this synthesis problem. In order to achieve scalability, this algorithm works in a modular way, treating different aspects of a graph data structure separately before encoding the search for logical rules as Boolean satisfiability problems to be dispatched to a SAT solver. Together with experimental collaborators, I applied this method to understanding the process of early blood development in the embryo, which is poorly understood due to the small number of cells present at this stage. The emergence of blood from Flk1+ mesoderm was studied by single cell expression analysis of 3934 cells at four sequential developmental time points. A mechanistic model recapitulating blood development was reconstructed from this data set, which was consistent with known biology and the bifurcation of blood and endothelium. Several model predictions were validated experimentally, demonstrating that HoxB4 and Sox17 directly regulate the haematopoietic factor Erg, and that Sox7 blocks primitive erythroid development. A general-purpose graphical tool was then developed based on this algorithm, which can be used by biological researchers as new single-cell data sets become available. This tool can deploy computations to the cloud in order to scale up larger high-throughput data sets. The results in this thesis demonstrate that single-cell analysis of a developing organ coupled with computational approaches can reveal the gene regulatory networks that underpin organogenesis. Rapid technological advances in our ability to perform single-cell profiling suggest that my tool will be applicable to other organ systems and may inform the development of improved cellular programming strategies.Microsoft Research PhD Scholarshi

Large-scale unit commitment under uncertainty: an updated literature survey

The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

The effect of contact angles and capillary dimensions on the burst frequency of super hydrophilic and hydrophilic centrifugal microfluidic platforms, a CFD study.

This paper employs the volume of fluid (VOF) method to numerically investigate the effect of the width, height, and contact angles on burst frequencies of super hydrophilic and hydrophilic capillary valves in centrifugal microfluidic systems. Existing experimental results in the literature have been used to validate the implementation of the numerical method. The performance of capillary valves in the rectangular and the circular microfluidic structures on super hydrophilic centrifugal microfluidic platforms is studied. The numerical results are also compared with the existing theoretical models and the differences are discussed. Our experimental and computed results show a minimum burst frequency occurring at square capillaries and this result is useful for designing and developing more sophisticated networks of capillary valves. It also predicts that in super hydrophilic microfluidics, the fluid leaks consistently from the capillary valve at low pressures which can disrupt the biomedical procedures in centrifugal microfluidic platforms