Reconfigurable nested ring-split ring transmitarray unit cell employing the element rotation method by microfluidics

A continuously tunable, circularly polarized X-band microfluidic transmitarray unit cell employing the element rotation method is designed and fabricated. The unit cell comprises a double layer nested ring-split ring structure realized as microfluidic channels embedded in Polydimethylsiloxane (PDMS) using soft lithography techniques. Conductive regions of the rings are formed by injecting a liquid metal (an alloy of Ga, In, and Sn), whereas the split region is air. Movement of the liquid metal together with the split around the ring provides 360° linear phase shift range in the transmitted field through the unit cell. A circularly polarized unit cell is designed to operate at 8.8 GHz, satisfying the necessary phase shifting conditions provided by the element rotation method. Unit cell prototypes are fabricated and the proposed concept is verified by the measurements using waveguide simulator method, within the frequency range of 8-10 GHz. The agreement between the simulation and measurement results is satisfactory, illustrating the viability of the approach to be used in reconfigurable antennas and antenna arrays. © 2015 IEEE

Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2); high error rates with Microscan WalkAway

<p>Abstract</p> <p>Background</p> <p>Increasing reports of carbapenem resistant <it>Acinetobacter baumannii </it>infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of <it>A. baumannii </it>isolates, by comparing to the validated test methods.</p> <p>Methods</p> <p>Selected 112 clinical isolates of <it>A. baumanii </it>collected between January 2003 and May 2006 were tested to confirm imipenem susceptibility results. Strains were tested against imipenem by the reference broth microdilution (BMD), disk diffusion (DD), Etest, BD Phoenix, MicroScan WalkAway and Vitek 2 automated systems. Data were analysed by comparing the results from each test method to those produced by the reference BMD test.</p> <p>Results</p> <p>MicroScan performed true identification of all <it>A. baumannii </it>strains while Vitek 2 unidentified one strain, Phoenix unidentified two strains and misidentified two strains. Eighty seven of the strains (78%) were resistant to imipenem by BMD. Etest, Vitek 2 and BD Phoenix produced acceptable error rates when tested against imipenem. Etest showed the best performance with only two minor errors (1.8%). Vitek 2 produced eight minor errors(7.2%). BD Phoenix produced three major errors (2.8%). DD produced two very major errors (1.8%) (slightly higher (0.3%) than the acceptable limit) and three major errors (2.7%). MicroScan showed the worst performance in susceptibility testing with unacceptable error rates; 28 very major (25%) and 50 minor errors (44.6%).</p> <p>Conclusion</p> <p>Reporting errors for <it>A. baumannii </it>against imipenem do exist in susceptibility testing systems. We suggest clinical laboratories using MicroScan system for routine use should consider using a second, independent antimicrobial susceptibility testing method to validate imipenem susceptibility. Etest, whereever available, may be used as an easy method to confirm imipenem susceptibility.</p

Performance limits of the three MEMS inertial energy generator transduction types

Accepted versio

A new laparoscopic technique for the placement of a permanent peritoneal dialysis catheter - The preperitoneal tunneling method

WOS: 000227332900014PubMed: 15529192Background: Mechanical outflow obstruction and leakage from the exit site of the catheter are two common complications of continuous ambulatory peritoneal dialysis. To lessen these complications and to achieve immediate use of the catheter, we developed a new laparoscopic technique for catheter placement. Methods: A total of 12 consecutive patients with end-stage renal failure were included in this study between April 2003 and July 2003. The average age of the patients was 42.4 years (range, 37-72). Patients were excluded only if a serious risk for general anesthesia was found. Using two 5-mm ports and a 3.3-mm mini-laparoscope, a peritoneal dialysis catheter was passed through a preperitoneal tunnel before the tip of the catheter was introduced into the pelvis. Routine peritoneal dialysis was started immediately after the operation while the patients were still in the operating room. Results: The mean operating time was 18.6 min (range, 12-37). There was no operative morbidity. The mean follow-up period was 4.3 months (range, 3-7). No leakage of the dialysate liquid or outflow obstruction was observed during this period. Conclusion: The advantages of this method include accurate placement, preperitoneal fixation, and immediate use of the catheter for routine peritoneal dialysis. We also believe that because of the preperitoneal fixation of the catheter, this technique will decrease outflow obstruction, which usually occurs due to omental wrapping or displacement of the catheter tip

A novel tunneling method for long-term peritoneal dialysis - Reply

WOS: 00023234340002

Pretransplant uric acid levels may be predictive for prognosis of renal transplant donors

Background The living kidney donor counseling prior to the operation may be helpful to learn how to properly care for the remaining single kidney for the rest of their lives. Worsening kidney function is associated with elevated serum uric acid (UA) levels. In this study, we compared the baseline laboratory findings of renal transplant donors with their follow-up laboratory values. Methods The study consisted of 173 adult donors including 91 females and 82 males with a mean age of 46.82 +/- 11.31 years. The follow-up clinical and laboratory examinations were performed on the third day at the end of the first and the sixth months of the surgery. According to donor's creatinine levels we constituted two groups: high creatinine and normal creatinine. Results Patients within the high creatinine group had significantly higher mean serum UA levels when compared with the normal creatinine group. In multivariate analysis, among the other effective variables, UA level alone was found to be the most effective parameter predicting the post-transplant creatinine levels (p = 0.004, odds ratio: 12.4, 95% CI: 2.3-68.3) at sixth month post-transplantation. In the ROC analysis for the effects of UA, the following cutoff values were found: >6 mg/dL in men (sensitivity 81.3%, specificity 76.9%, positive predictive value 89.7%, negative predictive value 62.5%, accuracy 80%) and >= 5 mg/dL in women (sensitivity 72.2, specificity 74.4%, positive predictive value 89.7%, negative predictive value 62.5%, accuracy: 73.7%). Conclusion Pretransplant serum UA levels can give important clues regarding the renal functions of the donors during the postoperative period

First isolation of vancomycin-resistant enteroccoci and spread of a single clone in a university hospital in northwestern Turkey

Reported here is the first isolation of vancomycin-resistant Enterococcus (VRE) at a hospital in northwestern Turkey and a description of the ensuing outbreak investigation. The first isolate was obtained from a wound culture of a patient in an intensive care unit. Thereafter, a total of 205 rectal swabs, 67 skin swabs and 123 environmental samples were screened, revealing five more VRE isolates. All isolates showed similar antibiotic resistance patterns, except for two that differed regarding gentamicin resistance. The vanA gene was present in all isolates. Pulsed-field gel electrophoresis demonstrated that all isolates belonged to a single clone, with the gentamicin-resistant isolates demonstrating two-band differences. This is the first outbreak to be caused by spread of a single VRE clone in Turkey; it was successfully controlled by strict adherence to appropriate infection control practices. © 2007 Springer-Verlag