Run-to-run failure detection and diagnosis using neural networks and Dempster-Shafer theory: an application to excimer laser ablation

The formation of microvias in multilayer substrates is a critical factor in microelectronic packaging manufacturing. Such microstructures can be produced efficiently by excimer laser ablation. Thus, laser ablation systems are evolving to a level where the need to offset high capital equipment investment and lower equipment downtime are imminent. This paper presents a methodology for inline failure detection and diagnosis of the excimer laser ablation process. The methodology employs response data originating directly from the equipment and characterization of microvias formed by the ablation process. Neural network (NN) models are trained and validated based on this data to generate evidential belief for potential sources of deviations in the responses. Dempster-Shafer (D-S) theory is adopted for evidential reasoning. Successful failure detection is achieved in 100% of 19 possible failure scenarios. Moreover, successful failure diagnosis is also achieved with only a single false alarm occurring in the 19 failure scenarios.     

Managing obesity through mobile phone applications: a state-of-the-art review from a user-centred design perspective

Evidence has shown that the trend of increasing obesity rates has continued in the last decade. Mobile phone applications, benefiting from their ubiquity, have been increasingly used to address this issue. In order to increase the applications’ acceptance and success, a design and development process that focuses on users, such as user-centred design, is necessary. This paper reviews reported studies that concern the design and development of mobile phone applications to prevent obesity, and analyses them from a user-centred design perspective. Based on the review results, strengths and weaknesses of the existing studies were identified. Identified strengths included: evidence of the inclusion of multidisciplinary skills and perspectives; user involvement in studies; and the adoption of iterative design practices. Weaknesses included the lack of specificity in the selection of end-users and inconsistent evaluation protocols. The review was concluded by outlining issues and research areas that need to be addressed in the future, including: greater understanding of the effectiveness of sharing data between peers, privacy, and guidelines for designing for behavioural change through mobile phone applications.     

Clearance of FGF‐23 during continuous renal replacement therapy

FGF‐23 is a 32 kDa protein that is a key regulator of phosphorus and vitamin D metabolism. Emerging evidence also demonstrates that FGF‐23 increases within 24 hours of acute kidney injury (AKI) and may be associated with adverse clinical outcomes. We conducted this study to evaluate FGF23 clearance during continuous veno‐venous hemofiltration (CVVH) in critically ill patients with AKI. We demonstrate that plasma clearance of FGF‐23 during CVVH is ～11 mL/min and the mean sieving coefficient is 0.27 ± 0.1. Future studies will need to clarify FGF‐23's role in adverse outcomes among AKI patients, and whether therapies aimed at reducing FGF‐23 levels may be beneficial.     

Bacteremia in a community hospital: spectrum and mortality

The problem of bacteremia was studied at our 500-bed community hospital during 1974-1975. All patients with positive blood cultures for clinically significant organisms were analyzed with respect to age, sex, host factors, type, dose, and time of institution of therapy with antibiotics, and mortality. Of 142 episodes of bacteremia, outcome according to underlying host factors showed that 12/15 died in the rapidly, fatal group, 12/24 died in the ultimately fatal group, and in the nonfatal group 25/103 died. Mortality for Gram-positive bacteremia was 37% (7/54) for Gram-negative bacteremia in the nonfatal group. In addition to underlying host factors, inappropriate antibiotic therapy also contributed to higher mortality in patients with gram-negative bacteremia.     

Humidity sensing and electrical properties of polyaniline/cobalt oxide composites

Polyaniline/cobalt oxide composites were synthesized by an in situ chemical polymerization method with ammonium persulfate as an oxidizing agent. This was a single‐step polymerization process for the direct synthesis of the emeraldine salt phase of the polymer. The polymers were characterized with X‐ray diffraction, scanning electron microscopy, and Fourier transform infrared spectral analysis. The formation of mixed phases of the polymer together with the conducting emeraldine salt phase was confirmed by spectroscopic techniques. High‐temperature conductivity measurements showed thermally activated behavior. A change in the resistance was observed with respect to the relative humidity when the pellets were exposed to a wide humidity range of 10–95%. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 653–658, 2007     

Toughening of bone cement using nanoparticle: The effect of solvent

Drawbacks of poly(methyl methacrylate) (PMMA)‐based bone cement as a grouting agent for in vivo fixation of orthopedic and dental implants such as considerable low mechanical strength have been improved using nanotechnology. Bone cement‐layered silicate nanocomposites have been prepared without any heat treatment in the presence of polar (dimethyl formamide, DMF) and nonpolar (benzene) solvents. Solvents have been removed completely from the bone cement after its preparation. Nanostructure is very much dependent on the solvent used for nanocomposite preparation, and benzene‐based nanocomposites are highly intercalated, whereas DMF‐based nanocomposites do not exhibit intercalation. Thermal stability of bone cement has improved in the presence of nanoclays. The relative enhanced interaction in case of benzene‐based nanocomposites has been shown through FTIR and UV–vis studies. The significant improvement in modulus and toughness of bone cement has been demonstrated in the presence of minimum amount of nanoclay for benzene‐based nanocomposites, whereas no change in modulus and reduced toughness have been observed for DMF‐based nanocomposites. The decrease of contact angle has been witnessed with increasing nanoclay concentration indicating better hydrophilic materials suitable for biomedical applications for greater cell growth. The reason for varying property enhancement in different solvents has been discussed considering the polarity effect and interactions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Formulation,in vitro evaluation and study of variables on tri-layered gastro-retentive delivery system of diltiazem HCl

Context: Tri-layered floating tablets using only one grade of polyethylene oxide (PEO) would enable easy manufacturing, reproducibility and controlled release for highly soluble drugs.

Objective: To evaluate the potential of PEO as a sole polymer for the controlled release and to study the effect of formulation variables on release and gastric retention of highly soluble Diltiazem hydrochloride (DTZ).

Methods: Tablets were compressed with middle layer consisting of drug and polymer while outer layers consisted of polymer with sodium bicarbonate. Design of formulation to obtain 12?h, zero-order release and rapid floatation was done by varying the grades, quantity of PEO and sodium bicarbonate. Dissolution data were fitted in drug release models and swelling/erosion studies were undertaken to verify the drug release mechanism. Effect of formulation variables and tablet surface morphology using scanning electron microscopy were studied.

Results and discussion: The optimized formula passed the criteria of USP dissolution test I and exhibited floating lag-time of 3–4?min. Drug release was faster from low molecular weight (MW) PEO as compared to high MW. With an increase in the amount of sodium bicarbonate, faster buoyancy was achieved due to the increased CO₂ gas formation. Drug release followed zero-order and gave a good fit to the Korsmeyer–Peppas model, which suggested that drug release was due to diffusion through polymer swelling.

Conclusion: Zero-order, controlled release profile with the desired buoyancy can be achieved by using optimum formula quantities of sodium bicarbonate and polymer. The tri-layered system shows promising delivery of DTZ, and possibly other water-soluble drugs.     

Variable Expression of GABAA Receptor Subunit Gamma 2 Mutation in a Nuclear Family Displaying Developmental and Encephalopathic Phenotype

Mutations in GABA_A receptor subunit genes (GABRs) are a major etiology for developmental and epileptic encephalopathies (DEEs). This article reports a case of a genetic abnormality in GABRG2 and updates the pathophysiology and treatment development for mutations in DEEs based on recent advances. Mutations in GABRs, especially in GABRA1, GABRB2, GABRB3, and GABRG2, impair GABAergic signaling and are frequently associated with DEEs such as Dravet syndrome and Lennox–Gastaut syndrome, as GABAergic signaling is critical for early brain development. We here present a novel association of a microdeletion of GABRG2 with a diagnosed DEE phenotype. We characterized the clinical phenotype and underlying mechanisms, including molecular genetics, EEGs, and MRI. We then compiled an update of molecular mechanisms of GABR mutations, especially the mutations in GABRB3 and GABRG2 attributed to DEEs. Genetic therapy is also discussed as a new avenue for treatment of DEEs through employing antisense oligonucleotide techniques. There is an urgent need to define treatment targets and explore new treatment paradigms for the DEEs, as early deployment could alleviate long-term disabilities and improve quality of life for patients. This study highlights biomolecular targets for future therapeutic interventions, including via both pharmacological and genetic approaches.