Characterization of mechanical behavior of electrospun non-woven mats

Electrospinning is a simple and efficient method for the production of nanometer to micrometer fibers. While the process of electrospinning has been known for over half a century, current understanding of the process and those parameters that affect the properties of the fibers is very limited. Not much work has been done in the field electrospinning process to study the mechanical properties of nonwoven mats produced and to study parameters affecting their properties. In the first part of this thesis electrospun nonwoven mats made of poly(lactides) solutions were characterized based on their mechanical behavior in biorelevant conditions. In the second part of this thesis the effect of aging of solution on the mechanical behavior of electrospun nonwoven mats was investigated using poly(c-caprolactone) as the solute. The yield strain of the mat has increased in biorelevent conditions compared to ordinary conditions though no significant difference in yield strength was observed. The yield strength of the aged solution mat was less than that of fresh solution mat and also its mechanical behavior has changed completely

A GPU-based Implementation for Improved Online Rebinning Performance in Clinical 3-D PET

Online rebinning is an important and well-established technique for reducing the time required to process Positron Emission Tomography data. However, the need for efficient data processing in a clinical setting is growing rapidly and is beginning to exceed the capability of traditional online processing methods. High-count rate applications such as Rubidium 3-D PET studies can easily saturate current online rebinning technology. Realtime processing at these high-count rates is essential to avoid significant data loss. In addition, the emergence of time-of-flight (TOF) scanners is producing very large data sets for processing. TOF applications require efficient online Rebinning methods so as to maintain high patient throughput. Currently, new hardware architectures such as Graphics Processing Units (GPUs) are available to speedup data parallel and number crunching algorithms. In comparison to the usual parallel systems, such as multiprocessor or clustered machines, GPU hardware can be much faster and above all, it is significantly cheaper. The GPUs have been primarily delivered for graphics for video games but are now being used for High Performance computing across many domains. The goal of this thesis is to investigate the suitability of the GPU for PET rebinning algorithms

Integration Of Maintenance Into Design And Sustainability Of Buildings

Custodial maintenance is an important aspect of operational maintenance in a facility. Custodial maintenance improves an organization\u27s discipline, performance and keeps surroundings healthy. That being said maintaining clean surroundings involves considerable cost. Custodial maintenance cost forms significant portion of building budgets, however these costs are often neglected. This research deals with the identification of variables that affect maintenance costs in a facility and reduction of maintenance costs. The minimization of cost is done by giving the administrator or facilities manager the option of selecting alternatives in frequency of maintenance, level of maintenance and the number of people required to complete a maintenance task. This allows the administrator to develop maintenance strategies to accommodate the custodial maintenance budget. An optimization model has been built to achieve the goals of the research. Furthermore, the custodial management system (CMS) developed based on an optimization model allows the administrator to design new buildings from the perspective of reduced custodial maintenance cost and to sustain these costs over time. A case study is presented to validate the working of the model and the software. A sensitivity analysis has also been presented to identify the best alternative for the case study

An approach for formal analysis of the security of a water treatment testbed

This thesis focuses on securing critical infrastructures such as chemical plants, manufacturing units, and power generating plants against attacks that disrupt the information flow from one component to another. Such systems are controlled by an Industrial Control System (ICS) that includes controllers communicating with each other, and with physical sensors and actuators, using a communications network. Traditional security models partition the security universe into two worlds, secure and insecure, but in the real world the partitions often overlap and information is leaked even through the physical observation which makes it much harder to analyze a Cyber physical system (CPS). To overcome these, this thesis focus on the Multiple Security Domain Nondeducibility (MSDND) model to identify the vulnerable points of attack on the system that hide critical information as in the STUXNET virus rather than theft of information. It is shown how MSDND analysis, conducted on a realistic multi-stage water treatment testbed, is useful in enhancing the security of a water treatment plant. Based on the MSDND analysis, this thesis offers a thorough documentation on the vulnerable points of attack, invariants used for removing the vulnerabilities, and suggested design decisions that help in developing invariants --Abstract, page iii

RECURRENT MALIGNANT APOCRINE SWEAT GLAND CARCINOMA - A CASE REPORT

Apocrine carcinomas arise from normal or modified sweat glands. The slow-growing nature and rarity of sweat gland carcinomas complicate their diagnosis at the early stage. The incidence of PASGC is quite low at 0.0049–0.0173 cases/100,000 persons/year. A 21-year-old male patient was presented in February 2016 with small solitary mass in the right axilla with mild tenderness and pain. Underwent wide local excision and axillary dissection at our institution followed by adjuvant radio and chemotherapy. Later on, after 18 months developed local recurrence and was planned for re-surgery and a second phase of palliative radiotherapy. After a year, presented to the hospital with pin sized irregular swelling in the axilla. Sweat gland carcinomas which are rarely diagnosed create a pathological dilemma due to their unpredicted biological behavior. However, wide local excision with or without nodal dissection is the primary treatment till date. In this particular case even though patient had underwent axillary node dissection, patient had recurrence twice with no distant metastasis which is a key point to be noted. Thorough study of the available apocrine carcinoma case reports or case series, the better knowledge regarding the apocrine carcinoma can be obtained

Indirect Impacts of COVID-19 on the Environment: A Global Review

Coronavirus (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus, which has plagued the Earth for the past two years and brought much controversy along with it. This report aims to analyze how the Covid-19 pandemic has had indirect effects on the environment. The onset of the pandemic has not only caused havoc disrupting routine average and businesses, but also claimed at least five million lives worldwide. This prompted the governments and the World Health Organization (WHO) to formulate measures to contain the transmission and the impact of the disease on the populations. Quarantine measures, movement restrictions, lockdowns and curfews, and travel bans are some of the most effective response methods that have helped the world contain the pandemic's spread. The adopted measures have had an indirect impact on the environment, opening the global community to numerous opportunities and threats. This report provides a critical analysis of how the Covid-19 pandemic has had indirect effects on the environment, examining how the response and containment measures have affected the environment. It focuses on air quality, water demand and quality, climate change, afforestation and deforestation, wildlife resurgence, littering, traffic congestion, noise reduction and changed human activities. It explores how the Covid-19 containment measures have had an environmental impact with a keen interest in the earlier areas

Toxicity Evaluation of Silver Nanoparticle in the Kidneys of Wistar Rats

This study aimed to evaluate the nephrotoxic effects of silver nanoparticles (AgNPs) in Wistar rats using biochemical, oxidative stress and histopathological changes. Three groups of six rats were orally administered AgNPs once a day for 28 days with doses of 100, 500, 1000 mg/kg bodyweight. A control group was administered with deionized water. Blood and kidneys were collected 24 h after the last treatment following standard protocols. The activities of creatinine and blood urea nitrogen against AgNP-induced toxicity was determined in the serum by colorimetric microplate assay. Various activity levels of oxidative stress including, Catalase (CAT), Superoxide dismutase (SOD), Glutathione peroxidase (GPx) and Lipid hydroperoxides (LPO) were evaluated in the kidney tissue. Scanning (SEM) and transmission electron microscopy (TEM) was used to determine the histopathological evaluation of the kidneys. A significant increase in the levels of serum creatinine, blood urea nitrogen, CAT and LPO, were noted in AgNPs exposed rats compared to that in control rats. In contrast, decreased activities of SOD and GPx in a dose-dependent manner was observed in AgNPs exposed rats relative to control rats. SEM and TEM study showed significant morphological alterations in kidneys of AgNPs exposed rats in accordance with the biochemical markers. The results of the study demonstrate that AgNPs might be nephrotoxic, and its toxicity is mediated through oxidative stress mechanism

Maternal serum ischemia modified albumin as a marker for hypertensive disorders of pregnancy: a pilot study

Background: Hypoxia driven oxidative stress of the placenta contributes to the pathogenesis of preeclampsia. Serum Ischemia Modified Albumin (IMA) has recently emerged as an oxidative stress marker, used in diagnosis of cardiac ischemia. Aim: To determine the efficiency of serum IMA in differentiating hypertensive disorders of pregnancy (pregnancy induced hypertension, preeclampsia) from normal pregnancy.Methods: It was a case control study. Pregnant women ≥32 weeks of gestation. Study population were included 3 groups, 19 Normotensive Pregnant (NP) women as controls, 18 pregnant women with Pregnancy Induced Hypertension (PIH) and 19 with preeclampsia (PE). Serum IMA was estimated by Enzyme Linked Immune Sorbent Assay (ELISA). Results were analyzed by student ‘t’test. Critical values for serum IMA were obtained by Receiver Operation Characteristics (ROC) curves.Results: Serum IMA levels were significantly elevated in PE (56.84 ± 21.57 ng/ml) when compared with PIH (36.24 ± 14.51 ng/ml) and NP (35.47 ± 11.58 ng/ml) (P value <0.001). With a cutoff of 38.33 ng/ml, sensitivity and specificity for preeclampsia was 88.9% and 73.7% respectively.Conclusions: Our study demonstrated that serum IMA, an oxidative stress marker is elevated in PE & PIH. Hence serum IMA can undergo further evaluation as a marker of PE.

Genotoxicity of Silver Nanoparticles in Vicia faba: A Pilot Study on the Environmental Monitoring of Nanoparticles

The use of silver nanoparticles (AgNPs) in commercial products has increased significantly in recent years. Although there have been some attempts to determine the toxic effects of AgNPs in mammalian and human cell-lines, there is little information on plants which play a vital role in ecosystems. The study reports the use of Vicia faba root-tip meristem to investigate the genotoxicity of AgNPs under modified GENE-TOX test conditions. The root tip cells of V. faba were treated with four different concentrations of engineered AgNPs dispersion to study toxicological endpoints such as mitotic index (MI), chromosomal aberrations (CA) and micronucleus induction (MN). For each concentration, five sets of microscopy observations were carried out. The results demonstrated that AgNPs exposure significantly increased (p < 0.05) the number of chromosomal aberrations, micronuclei, and decreased the MI in exposed groups compared to control. From this study we infer that AgNPs might have penetrated the plant system and may have impaired mitosis causing CA and MN. The results of this study demonstrate that AgNPs are genotoxic to plant cells. Since plant assays have been integrated as a genotoxicity component in risk assessment for detection of environmental mutagens, they should be given full consideration when evaluating the overall toxicological impact of the nanoparticles in the environment

Heart Transplantation in the United States, 1999–2008

This article features 1999–2008 trends in heart transplantation, as seen in data from the Organ Procurement and Transplantation Network (OPTN) and the Scientific Registry of Transplant Recipients (SRTR). Despite a 32% decline in actively listed candidates over the decade, there was a 20% increase from 2007 to 2008. There continues to be an increase in listed candidates diagnosed with congenital heart disease or retransplantation. The proportion of patients listed as Status 1A and 1B continues to increase, with a decrease in Status 2 listings. Waiting list mortality decreased from 2000 through 2007, but increased 18% from 2007 to 2008; despite the increase in waiting list death rates in 2008, waiting list mortality for Status 1A and Status 1B continues to decrease. Recipient numbers have varied by 10% over the past decade, with an increased proportion of transplants performed in infants and patients above 65 years of age. Despite the increase in Status 1A and Status 1B recipients at transplant, posttransplant survival has continued to improve. With the rise in infant candidates for transplantation and their high waiting list mortality, better means of supporting infants in need of transplant and allocation of organs to infant candidates is clearly needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79117/1/j.1600-6143.2010.03042.x.pd