Issues in the mining of heart failure datasets

This paper investigates the characteristics of a clinical dataset using a combination of feature selection and classification methods to handle missing values and understand the underlying statistical characteristics of a typical clinical dataset. Typically, when a large clinical dataset is presented, it consists of challenges such as missing values, high dimensionality, and unbalanced classes. These pose an inherent problem when implementing feature selection and classification algorithms. With most clinical datasets, an initial exploration of the dataset is carried out, and those attributes with more than a certain percentage of missing values are eliminated from the dataset. Later, with the help of missing value imputation, feature selection and classification algorithms, prognostic and diagnostic models are developed. This paper has two main conclusions: 1) Despite the nature of clinical datasets, and their large size, methods for missing value imputation do not affect the final performance. What is crucial is that the dataset is an accurate representation of the clinical problem and those methods of imputing missing values are not critical for developing classifiers and prognostic/diagnostic models. 2) Supervised learning has proven to be more suitable for mining clinical data than unsupervised methods. It is also shown that non-parametric classifiers such as decision trees give better results when compared to parametric classifiers such as radial basis function networks(RBFNs).     

NOVEL ENERGY-SAVING METHOD OF RECTIFICATION

The conventional rectification method to separate and purify chemical mixtures has the disadvantage of being an energy-intensive unit operation. The innovative method proposed in this article employs vapor and liquid recycles to the trays that in turn reduce the reflux rate and vapor boil-up rate, resulting in energy reduction without compromising the separations.

These findings were supported with examples of ethanol-water and butane- pentane system separations. With ethanol-water system, the experiments were conducted without overhead liquid recycle and using 16 and 5 vapor recycles. The energy saved was found to be 25-35% for 16 recycles and 20-30% for 5 recycles. Butane-pentane system was chosen as an example of industrial use of the proposed method. A liquid overhead reflux ratio of 0.5 (L/D) was used with vapor recycles, compared to a reflux ratio of 1.25 for the conventional separation without vapor recycles. This resulted in 30-35% saving in energy while giving the same productivity of the column. Butane-pentane separation was also simulated using a commercial process simulator (ASPEN^©PLUS).     

Degradation of DC characteristics of InGaAs/InP singleheterojunction bipolar transistors under electron irradiation

The effects of high-energy (~1 MeV) electron irradiation on the dc characteristics of InGaAs/InP single heterojunction bipolar transistors (SHBT's) are investigated. The device characteristics do not show any significant change for electron doses <10¹⁵/cm². For higher doses, devices show a decrease in collector current, a degradation of common-emitter current gain, an increase in collector saturation voltage and an increase in the collector output conductance. A simple SPICE-like device model is developed to describe the dc characteristics of SHBT's. The model parameters extracted from the measured dc characteristics of the devices before and after irradiation are used to get an insight into the physical mechanisms responsible for the degradation of the devices     

Low-temperature hydrothermal synthesis of NiEuFe2O4 nanoparticles: Magnetic,thermal, and magneto-dielectric behavior

The Ni_1−xEu_xFe₂O₄ (x = .02–.08) (NEF) nanoparticles are prepared using the low-temperature hydrothermal method. The X-ray diffraction patterns evidenced the cubic structure of NEF having the increasing trend of lattice constants from .8971 to .8984 nm as a function of Eu-content. The microstructure reveals the asymmetrical spheres like nanosized grains and particles. The particle size seemed to be increasing from 67.3 to 103.7 nm with x. The magneto-dielectric and magneto-loss natures are studied as a function of frequency and composition at the varying magnetic field of .0–1.5 T. The hysteresis nature of NEF is observed from magnetization versus (M–H) curves. The results ensured that the x = .08 content provided the highest magnetization of 89.03 emu/g. The mass loss (Δm) and transition temperatures are determined using TG–DSC curves. The endothermic and exothermic temperatures are clearly noticed for x = .02–.08.     

Squeezing Organic Conjugated Molecules—What Does One Learn?

The effects of hydrostatic pressure on conjugated polymers, in particular polyphenyls (see Figure for monomer unit) have been studied using photoluminescence, absorption, photo‐induced absorption, and Raman spectroscopy. The effect of pressure on the singlet and triplet excitons and polarons allows an understanding of localized and delocalized electronic states. Changes in the intensity ratios of Raman bands that correspond to vibrations of a perpendicular and a coplanar array of phenyl rings in the chain, and comparison with calculated intensities, demonstrate the influence of pressure on the polymer's conformation.     

Degradation of InGaAs/InP single heterojunction bipolar transistors under high energy electron irradiation

The d.c. characteristics of InGaAs/InP single heterojunction bipolar transistors (SHBTs) were studied for the first time under high energy (1 MeV) electron radiation of cumulative dose up to 5.4×10¹⁵ electrons/cm². No degradation was observed for electron doses below 10¹⁵/cm². For electron doses greater than 10¹⁵/cm² the following degradation effects were observed: (1) decrease in collector current; (2) decrease in current gain up to 50%; (3) an increase in collector saturation voltage by 0.2–0.8 V depending on base current; and (4) increase in output conductance. The degradation of collector current and current gain are thought to be due to increased recombination caused by radiation-induced defects in the base–emitter junction. The increase in collector saturation voltage is attributed to an increase in emitter contact resistance after irradiation. The increase in the avalanche multiplication in the reverse biased base–collector junction caused by radiation induced defects is believed to be responsible for increased output conductance after irradiation.     

Build optimization of fiber-reinforced additively manufactured components

Structural and Multidisciplinary Optimization - Additive manufacturing (AM) has enabled the fabrication of artifacts with unprecedented geometric and material complexity. The focus of this paper is...     

An improved synthesis of lysosomal activated mustard prodrug for tumor-specific activation and its cytotoxic evaluation

Cyclophosphamide, an alkylating agent widely used as anticancer agent, biotransformed in vivo to unstable phosphoramidic mustard and acrolein, where the latter metabolite has been found responsible for hemorrhagic cystitis and renal toxicity. Being one of the most popular strategies to avoid these deleterious effects, prodrug design has been attempted, which can, in addition, enable selective drug targeting. Our efforts to design, synthesize and evaluate the enzymatically activated prodrug phosphorodiamidic mustard as potential candidate for selective chemotherapy in antibody-directed enzyme prodrug therapy or prodrug monotherapy strategies are described. We propose an improved synthesis of prodrug 14, consisting of a galactose moiety, a spacer and a cytotoxic drug and its cytotoxicity has been investigated. The prodrug 14 has been found to be nontoxic (in vitro) which could be a valuable candidate for further development.     

Bio-electrohydrolysis as a pretreatment strategy to catabolize complex food waste in closed circuitry: Function of electron flux to enhance acidogenic biohydrogen production

A novel bio-electrohydrolysis system (BEH) based on self-inducing electrogenic activity was designed as a pretreatment device to enhance biohydrogen (H₂) production efficiency of food waste. Experimental strategy involved two-stage integrated/hybrid operation with hydrolysis in initial stage followed by acidogenic fermentation for H₂ production in second stage. After pre-treatment, catabolized food waste from control (anaerobic) and BEH (closed circuit mode of operation) system was used as substrate in a separate bioreactor to evaluate H₂ production in dark-fermentation process. Pretreated-waste from BEH showed higher H₂ production (29.12 ml/h; 24th h) than control (26.75 ml/h; 16th h). Higher cumulative H₂ production and maximum substrate degradation were also noticed with BEH-pretreated substrate (CHP, 0.91 l; COD, 52.42%) than control (CHP, 0.68 l; COD, 43.68%). Under closed circuitry, anode served as an alternative electron acceptor promoting biotransformation of complex organics to simpler molecules through catabolism.