Vibroacoustic performance of fiber metal laminates with delamination

In the present work, the numerical assessment of vibroacoustic (VA) performance of fiber metal laminates (FML) with mid-plane center delamination is presented. A fluid structure interaction study has been done using finite element method (FEM). Experimental validation is performed on an aluminium (AL) panel for verifying the correctness of finite element (FE) idealization procedure to simulate the fluid-structure interaction. Delamination is introduced in the FE model of FML panel and VA analysis is subsequently carried out. Sound transmission loss (STL) is computed on the panel with center delamination and without delamination. The overall sound pressure level (OASPL) shows that the presence of delamination (40% in total area) in FML has not changed the total energy of the transmitted sound when compared to aluminium and composites. However, in the narrow frequency bands (150–200 Hz, 200–250 Hz), the sound transmission nature has been significantly affected due to local delamination modes participating in the fluid-structure interaction process

High-Level Model Extraction via Symbolic Execution

We study the problem of extracting high-level state machine models from software source code. Our target domain is GUI-driven applications for small hand-held devices such as cell phones and PDAs. In such systems, a natural high-level model is captured by a state machine, where states are GUI screens and button/menu item tappings are actions that trigger transitions between states. The paper presents a symbolic execution technique that allows us to identify states and transitions from the application source code. We discuss an implementation of this technique that operates on a large subset of the C# language and apply as a case study to the subsystem of a decision support tool for medical diagnosis

Influence of active stiffening on dynamic behaviour of piezo-hygro-thermo-elastic composite plates and shells

The active stiffening and active compensation analyses are carried out to present the influence of active stiffness on the dynamic behaviour of piezo-hygro-thermo-elastic laminates. A coupled piezoelectric finite element formulation involving a hygrothermal strain field is derived using the virtual work principle and is employed in a nine-noded field consistent Lagrangian element. The closed-loop system is modelled with elastic stiffness, active stiffness introduced by isotropic actuator lamina and geometric stiffness due to stresses developed by hygrothermal strain. Through a parametric study, the influence of active stiffening and active compensation effects on the dynamics of cross-ply and angle-ply laminated plates and shells are highlighted. The active stiffening on thin shells is significantly influenced by boundary effects and the actuator efficiency further decreases with increase in curvature. The reduction in natural frequencies of cross-ply laminates due to hygrothermal strain is actively compensated by active stiffening; however, it is observed that the actuator performance reduces significantly with increase in curvature particularly in angle-ply laminates, which demands the use of directional actuators. The active stiffening and active compensation effects are low in moderately thick piezo-hygro-thermo-elastic plates and shells, which are less influenced by boundary conditions

Calcific Uremic Arteriolopathy in Peritoneal Dialysis Populations

Calciphylaxis or calcific uremic arteriolopathy is an infrequent complication of end stage kidney disease. It is characterized by arteriolar medial calcification, thrombotic cutaneous ischemia, tissue necrosis often leading to ulceration, secondary infection and increased mortality rates. Current, multimodality treatment involves local wound care, well-controlled calcium, phosphate and parathyroid hormone levels and combination therapy with sodium thiosulfate and hyperbaric oxygen therapy. This combination therapy may be changing the historically poor prognosis of calcific uremic arteriolopathy reported in the literature. Peritoneal dialysis is considered a risk factor based on limited publications, however this remains to be proven. Clinical presentation, diagnosis, pathogenesis and treatment of calcific uremic arteriolopathy in these patients are no different from other patients manifesting with this condition

Vibroacoustic Performance of Fiber Metal Laminates with Delamination

In the present work, the numerical assesment of vibroacoustic (VA) performance of Fibre Metal Laminates (FML) with mid-plane center delamination is presented. A fluid structure interaction study has been done using Finite Element Method (FEM). Experimental validation is performed on aluminium panel for verifying the correctness of Finite Element idealization procedure to simulate the fluid-structure interaction. Delamination is introduced in the FE model of FML panel and VA analysis is subsequently carried out. Sound Transmission Loss (STL) is computed on the panel with center delamination and without delamination. The Over All Sound Pressure Level (OASPL) shows that the presence of delamination (40% in total area) in FML has not changed the total energy of the transmitted sound, when compared to aluminium and composites. However, in the narrow frequency bands (150-200 Hz, 200-250 Hz) the sound transmission nature has been significantly affected due to local delamination modes, participating in the fluid-structure interaction process

Randomised Controlled Trial to determine the appropriate time to initiate peritoneal dialysis after insertion of catheter to minimise complications (Timely PD study)

Background. The most appropriate time to initiate dialysis after surgical insertion of Tenckhoff catheters is not clear in the literature. There is the possibility of peritoneal dialysis (PD) complications such as leakage and infection if dialysis is started too soon after insertion. However, much morbidity and expense could be saved by reducing dependency on haemodialysis (HD) by earlier initiation of PD post catheter insertion. Previous studies are observational and mostly compare immediate with delayed use. The primary objective is to determine the safest and shortest time interval between surgical placement of a Tenckhoff catheter and starting PD. Methods/Design. This is a randomised controlled trial of patients who will start PD after insertion of Tenckhoff catheter at Royal Brisbane and Women's Hospital (RBWH) or Rockhampton Base Hospital (RBH) who meet the inclusion criteria. Patients will be stratified by site and diabetic status. The patients will be randomised to one of three treatment groups. Group 1 will start PD one week after Tenckhoff catheter insertion, group 2 at two weeks and group 3 at four weeks. Nurses and physicians will be blinded to the randomised allocation. The primary end point is the complication rate (leaks and infection) after initiation of PD. Discussion. The study will determine the most appropriate time to initiate PD after placement of a Tenckhoff catheter

Case Report Dialysis and Pregnancy in End Stage Kidney Disease Associated with Lupus Nephritis

Female patients with systemic lupus erythematosus are often of childbearing age at diagnosis, and though fertility in these patients is similar to the general population, successful pregnancy remains a rare occurrence. This incidence is, however, increasing and the management of these high risk pregnancies is often further complicated by the patient's need for dialysis as a result of lupus nephritis (LN). We share our experience in managing two LN patients with successful pregnancies, one on automated peritoneal dialysis and the other on haemodialysis, as well as a review of cases in the literature

Psychosocial Factors in End-Stage Kidney Disease Patients at a Tertiary Hospital in Australia

Aim. This study seeks to review the psychosocial factors affecting patients with end-stage kidney disease (ESKD) from a tertiary hospital in Australia. Methods. We audited patients with ESKD, referred to social work services from January 2012 to December 2014. All patients underwent psychosocial assessments by one, full-time renal social worker. Patient demographics, cumulative social issues, and subsequent interventions were recorded directly into a database. Results. Of the 244 patients referred, the majority were >60 years (58.6%), male (60.7%), born in Australia (62.3%), on haemodialysis (51.6%), and reliant on government financial assistance (88%). Adjustment issues (41%), financial concerns (38.5%), domestic assistance (35.2%), and treatment nonadherence (21.3%) were the predominant reasons for social work consultation. Younger age, referral prior to start of dialysis, and unemployment were significant independent predictors of increased risk of adjustment issues ( = 0.004, <0.001, and =0.018, resp.). Independent risk factors for treatment nonadherence included age and financial and employment status ( = 0.041, 0.052, and 0.008, resp.). Conclusion. Psychosocial and demographic factors were associated with treatment nonadherence and adjustment difficulties. Additional social work support and counselling, in addition to financial assistance from government and nongovernment agencies, may help to improve adjustment to the diagnosis and treatment plans as patients approach ESKD

The influence of biofilms on carbapenem susceptibility and patient outcome in device associated K. pneumoniae infections : insights Into phenotype vs genome-wide analysis and correlation

Klebsiella pneumoniae is one of the leading causes of nosocomial infections. Carbapenem-resistant K. pneumoniae are on the rise globally. The biofilm forming ability of K. pneumoniae further complicates patient management. There is still a knowledge gap on the association of biofilm formation with patient outcome and carbapenem susceptibility, which is investigated in present study. K. pneumoniae isolates from patients admitted in critical care units with catheters and ventilators were included. K. pneumoniae (n = 72) were subjected to 96-well plate biofilm formation assay followed by MBEC assay for subset of strong biofilm formers. Whole genome sequencing and a core genome phylogenetic analysis in comparison with global isolates were performed. Phenotypic analyses showed a positive correlation between biofilm formation and carbapenem resistance. Planktonic cells observed to be susceptible in vitro exhibited higher MICs in biofilm structure, hence MICs cannot be extrapolated for treatment. The biofilm forming ability had a significant association with morbidity/mortality. Infections by stronger biofilm forming pathogens significantly (p < 0.05) resulted in fewer “average days alive” for the patient (3.33 days) in comparison to those negative for biofilms (11.33 days). Phylogenetic analysis including global isolates revealed clear association of sequence types with genes for biofilm formation and carbapenem resistance. Known hypervirulent clone-ST23 with wcaG, magA, rmpA, rmpA2, and wzc with lack of mutation for hyper-capsulation might be poor biofilm formers. ST15, ST16, ST307, and ST258 (reported global high-risk clones) were wcaJ negative indicating the high potential of biofilm forming capacity. Genes wabG and treC for CPS, bcsA and pgaC for adhesins, luxS for quorum sensing were common in all clades in addition to genes for aerobactin (iutA), allantoin (allS), type I and III fimbriae (fimA, fimH, and mrkD) and pili (pilQ and ecpA). This study is the first of its kind to compare genetic features of antimicrobial resistance with a spectrum covering most of the genetic factors for K. pneumoniae biofilm. These results highlight the importance of biofilm screening to effectively manage nosocomial infections by K. pneumoniae. Further, data obtained on epidemiology and associations of biofilm and resistance genetic factors will serve to enhance our understanding on biofilm mechanisms in K. pneumoniae

Randomised Controlled Trial to determine the appropriate time to initiate peritoneal dialysis after insertion of catheter to minimise complications (Timely PD study)

Background. The most appropriate time to initiate dialysis after surgical insertion of Tenckhoff catheters is not clear in the literature. There is the possibility of peritoneal dialysis (PD) complications such as leakage and infection if dialysis is started too soon after insertion. However, much morbidity and expense could be saved by reducing dependency on haemodialysis (HD) by earlier initiation of PD post catheter insertion. Previous studies are observational and mostly compare immediate with delayed use. The primary objective is to determine the safest and shortest time interval between surgical placement of a Tenckhoff catheter and starting PD. Methods/Design. This is a randomised controlled trial of patients who will start PD after insertion of Tenckhoff catheter at Royal Brisbane and Women's Hospital (RBWH) or Rockhampton Base Hospital (RBH) who meet the inclusion criteria. Patients will be stratified by site and diabetic status. The patients will be randomised to one of three treatment groups. Group 1 will start PD one week after Tenckhoff catheter insertion, group 2 at two weeks and group 3 at four weeks. Nurses and physicians will be blinded to the randomised allocation. The primary end point is the complication rate (leaks and infection) after initiation of PD. Discussion. The study will determine the most appropriate time to initiate PD after placement of a Tenckhoff catheter