1,764 research outputs found
Cerebral Amyloid Angiopathy and Intracerebral Hemorrhage
https://scholarlycommons.henryford.com/detstrokeconf2019/1012/thumbnail.jp
RHEOLOGICAL BEHAVIOR OF DSPC-, DBPC-, AND DPPC-OXYGEN MICROBUBBLES AND THEIR EFFECTIVENESS IN IMPROVING SURVIVAL IN A RAT MODEL OF LIPOPOLYSACCHARIDE-INDUCED ACUTE RESPIRATORY DISTRESS SYNDROME
Acute respiratory distress syndrome (ARDS) causes 75,000 deaths in the U.S., annually. It is characterized by hypoxemia and damage to the lung alveoli. ARDS Management strategies involve extracorporeal membrane oxygenation (ECMO) and mechanical ventilation, but none of these methods improve the mortality rates. Oxygen microbubbles (OMBs) consist of a lipid shell with an oxygen core and have potential to augment oxygenation to manage ARDS. Previous studies demonstrated significant improvements in systemic oxygenation and mortality upon administering OMBs.
We replicated an ARDS rat model by intratracheal administration of lipopolysaccharide at a 24 mg/kg dose. After inducing the disease in rats, the distearoylphosphatidylcholine (DSPC), dibehenoylphosphatidylcholine (DBPC), or dipalmitoylphosphatidylcholine (DPPC) OMBs were administered intraperitoneally at a 100 mL/kg dose every 12 h, up to 36 h. Arterial blood gas analysis and pulse oximetry were then performed. Results showed 77.8%, 20%, and 10% survival in the DSPC, DBPC, and DPPC groups. Rats in the first group had significantly greater survival than others. Beyond 12 hours, the mean %SpO2 and PaO2 of rats was greater in the DSPC group. Additionally, the mean edema score, wet/dry ratio, and inflammation scores were lower in the DSPC group.
The rheological behavior was characterized using a rotating rheometer. The oxygen microbubbles showed a shear-thinning behavior. The results also showed that the viscosity decreased with a decreasing volume fraction and increasing temperature. Lipids with longer chain lengths showed greater viscosities and greater storage and loss moduli. The viscoelastic behavior at lower angular frequencies was predominantly viscous. At greater frequencies, the behavior was predominantly elastic. These results explain the behavior of OMBs when acted upon by a stress. Non-Newtonian fluid models (Casson, Herschell-Bulkley, Power-law) were fit to the shear stress-shear strain data and the R2 and best-fit parameters were obtained to assess the fit. The viscoelastic behavior provides insight into the structure, molecular weight, and temperature-dependent properties of a material.
Advisor: Benjamin S. Terr
On Centralizing and Generalized Derivations Of prime Rings with involution
Let (R,∗) be a 2-torsion free ∗-prime ring with involution ∗, L= 0 be a nonzero square closed ∗-Lie ideal of R and Z the center of R. An additive mapping F: R −→ R is called a generalized derivation on R if there exists a derivation d: R−→Rcommutes with ∗ such that F(xy) = F(x)y +xd(y) holds for all x,y ∈ R. In the present paper, we shall show that L is contained in the center of R such that R admits a generalized derivations F and G with associated derivations d and g commute with ∗ satisfying several conditions
Select Financial Ratios as a Determinant of Profitability Evidence from Petrochemical Industry in Saudi Arabia
The pedestal of economic growth of the Kingdom of Saudi Arabia cardinally hinges upon the growth and development of the Petrochemical companies. Of late, there is risk of an increase in feedstock cost, which can pressurize margins for Saudi companies. This has encouraged the researchers to analyze the profitability and select financial ratios of petrochemicals industry in Saudi Arabia. The research paper makes an endeavor to determine the profitability of listed Petrochemical companies in Saudi Arabia with five years accounting period from 2008 to 2012. The paper encompasses six variables, namely, Creditors’ Velocity (CRSV), Debtors’ Turnover Ratio (DTR), Inventory Turnover Ratio (ITR), Long-Term-Debt to Equity Ratio (LTDER), Total Assets Turnover Ratio (TATR) and Net profit Margin (NPM). Profitability as a dependent variable is exhibited by Net profit Margin (NPM) while the select ratios (CRSV), (DTR), (ITR), (LTDER), (TATR) are expressed as independent variables. Based on the findings of the study, it is cogently revealed that there is a significant relationship between the four selected ratios and Net Profit Margin (NPM) of Petrochemical companies in Saudi Arabia. Keywords: Profitability, Financial Ratios, Petrochemical industr
Follicular sensitivity index: A tool to predict successful conception after intra-cytoplasmic sperm injection
Follicular sensitivity index (FSI) is used for estimation of follicular responsiveness to controlled ovarian hyperstimulation (COH) during intra-cytoplasmic sperm injection (ICSI). In a retrospective study, FSI of 1,385 females was calculated as [pre-ovulatory follicle count (PFC) × 100,000]/ [antral follicle count (AFC) × total received stimulation doses]. Females were then categorised into low, middle and high FSI groups according to FSI tertile values. FSI was 8.65 ±2.82 in non-pregnant as compared to 12.02 ±2.04 (p \u3c0.01) in pregnant cohort. FSI turned out to be a strong predictor of successful conception on the receiver operating curve with cutoff value 10.36 at 76% specificity, sensitivity of 86% and area under the curve (AUC; 0.83). Calculation of FSI can thus predict the chances of successful conception in females with different causes of infertility
Development of volume function for final felling of Pinus brutia Ten in Kurdistan Iraq
Planning for forest management depends upon the forest dynamics, which includes integration of all forest disciplines and understanding of forest resource characteristics including its growth dynamics. The forest growth and yield modelling can provide valuable information about forestry which can be used to determine harvest levels or allowable cut, and to analyze alternative stand treatments. Growth and yield models are generally used to predict the temporal development of forest stands. Knowledge of Diameter at Breast Height (DBH) and total tree height is fundamental to both developing and applying many growth and yield models [1]. Among the several available approaches in the yield prediction methodology, the multilevel model approach, which is a statistical technique, found to be commonly used in many fields of study for generating improvements in parameter estimation .A volume estimation of a forest stand is a good example. Volume estimation in the form of volume function and volume table has been widely used for many different purposes in forestry for more that hundred years including forest plantations and an inventory for timber harvesting. In view of the importance of these functions in forestry, this study was conducted with the main aim to develop a volume function for Pinus brutia Ten, which is a very common forest tree species planted in northern Iraq. The least squares method was used to fit eight unweighted volume equations including two logarithmic transformed equations and seven weighted forms of volume equations to volume data of a 25-30 years old Pinus brutia Ten plantation. The best fit equation was done using Furnival’s index
Nondestructive test methods for concrete bridges: A review
NDT methods applicable to concrete bridges are reviewed. The methodology, advantages and disadvantages along with up to date research on NDT methods are presented. Different damage levels, having less dependence on inspector judgment, are suggested. Moreover, a flow chart based on damage level along with NDT methods and potential remedial measures are proposed for periodic health monitoring of structures
An Alternate Account on the Ethical Implications of Autonomous Vehicles
Given the widespread popularity of Autonomous Vehicles (AVs), researchers have been exploring the ethical implications of AVs. Researchers believe that empirical experiments can provide insights into human characterization of ethically sound machine behavior. Previous research indicates that humans generally endorse utilitarian AVs, however, this paper explores an alternative account on the discourse of ethical decision-making in AVs. We refrain from favoring consequentialism or non-consequential ethical theories, and argue that human moral decision-making is pragmatic, or in other words, ethically and rationally bounded. We hold the perspective that our moral preferences shift based on various externalities and biases. To further this concept, we conduct two Amazon Mechanical Turk studies to investigate factors, such as, the \u27degree of harm\u27, and \u27level of affection\u27, which influence people\u27s moral decision-making. Our experimental findings seem to suggest that human moral judgements cannot be wholly deontological or utilitarian. We discovered that as the degree of harm decreased, people became less utilitarian (more deontological), and as the level of affection increased, people became less utilitarian (more deontological). These findings offer evidence on the ethical variations in human decision-making processes and refutes the view that aim to advocate application of a specific moral framework based on empirical evidence. The findings also offer useful insights for policymakers to explore the overall public perception on the ethical implications of AV
Ultrafast monolithic HPLC method for simultaneous quantification of the anticancer agents, imatinib and sorafenib: Application to tablet dosage forms
Purpose: To develop and validate a simple ultrafast monolithic high performance liquid chromatography (HPLC) method for the simultaneous quantification of two anti-cancer agents, imatinib and sorafenib, in pure form and tablet preparations.Method: Chromatographic separation was accomplished using Chromolith flash RP-18 HPLC-column (25 - 4.6 mm; macropores, 2 μm; mesopores, 13 – 15 nm). The optimum mobile phase composition of ammonium acetate buffer (10 mM, pH 8.5) and methanol at ratio of 35:65 v/v was used. Effluent flow rate was adjusted to 1.0 mL/min and the analysis was performed at 250 nm wavelength. The developed method was evaluated for specificity, linearity, precision and accuracy.Results: The method offered a linear relationship over the concentration range of 1 - 16 μg/ml (correction coefficient, R2 = 0.9999) for both analytes. Limit of detection (LOD) was 0.1891 and 0.1888 μg/ml while limit of quantification (LOQ) was 0.6303 and 0.6294 μg/ml for imatinib and sorafenib, respectively. Mean recovery was within 100 ± 2 %. The utility of the new method was demonstrated by its successful use for the analysis of commercially available tablet formulations of both drugs.Conclusion: The developed method is fast and economical, and is being recommended for routine analysis of imatinib and sorafenib in bulk drug and tablet dosage forms in quality control laboratories.Keywords: RP-HPLC, Chromolith, Imatinib, Sorafenib, Validation, Quality contro
- …