On the transient performance of a class of second-order limit-cycling control systems

An approach is described for the study of the transient performance of a class of second-order limit-cycling control systems. The geometrical features of the problem are used to derive expressions relating the limit-cycle dimensions with the excess overshoot. An example of application is studied using this approach.     

High mRNA Expression Levels of Heat Shock Protein Family B Member 2 (HSPB2) Are Associated with Breast Cancer Patients’ Relapse and Poor Survival

Small heat shock proteins (sHSPs) are ubiquitous ATP-independent chaperones that contribute to the maintenance of proteome integrity and functionality. Recent evidence suggests that sHSPs are ubiquitously expressed in numerous types of tumors and have been proposed to be implicated in oncogenesis and malignant progression. Heat shock protein family B member 2 (HSPB2) is a member of the sHSPs, which is found to be expressed, among others, in human breast cancer cell lines and constitutes an inhibitor of apical caspase activation in the extrinsic apoptotic pathway. In this study, we investigated the potential prognostic significance of HSPB2 mRNA expression levels in breast cancer, which represents the most frequent malignancy in females and one of the three most common cancer types worldwide. To this end, malignant breast tumors along with paired non-cancerous breast tissue specimens were used. HSPB2 expression levels were quantified in these two cohorts using a sensitive and accurate SYBR green-based quantitative real-time polymerase chain reaction (q-RT-PCR). Extensive biostatistical analyses were performed including Kaplan–Meier and Cox regression survival analyses for the assessment of the results. The significant downregulation of HSPB2 gene expression was revealed in breast tumors compared to their adjacent non-cancerous breast tissues. Notably, high HSPB2 mRNA expression predicts poor disease-free survival and overall survival of breast cancer patients. Multivariate Cox regression analysis revealed that HSPB2 mRNA overexpression is a significant predictor of poor prognosis in breast cancer, independent of other clinicopathological factors. In conclusion, high HSPB2 mRNA expression levels are associated with breast cancer patients’ relapse and poor survival.     

Analysis of ESD failure mechanism in 65nm bulk CMOS ESD NMOSFETs with ESD implant

Electrical and SEM analysis of gate-silicided (GS) ESD NMOSFETs in a 65nm bulk CMOS technology show that the failure mechanism changes from source-to-drain filamentation to drain-to-substrate short when a p-type ESD implant (ED) is used. Simulations show that the reason for change in failure mode is the different current and temperature distribution when the device is operated in bipolar mode due to the presence of ED. The size of the drain silicide blocking can be reduced from 3 to 0.75 μm by the use of ED while keeeping the same ESD failure current with the corresponding area saving benefit. When the ED implant extends under the drain contacts, the on-resistance (Ron) of the device can be reduced by 50% with respect to a design where ED is not located under the contacts.     

An improved DOA estimation algorithm for asynchronous multipath CDMA system

This paper proposes an improved Direction Of Arrival（DOA） estimation algorithm for asynchronous multipath Code Division Multiple Access（CDMA） system. The algorithm is based on the correlation matrices of outputs of decorrelator, which is a Multi-User Detection（MUD） approach, one of the key techniques for CDMA system. Through decorrelating processing, the desired user＇s mulipath signals can be resolved and all the other resolved multipath signal interference is eliminated. So the proposed algorithm is expected to perforln much better than algorithm such as that based directly on the Matched Filter（MF） bank outputs. Simulation results confirm this. While the improved algorithm performs better and better as Signal-to-Noise Ratio（SNR） increases, the performance of algorithm based directly on the MF bank outputs can not be improved.     

Impairment of left atrial appendage function after spontaneous conversion of atrial flutter

This paper reports a patient in atrial flutter who spontaneously converted to sinus rhythm while undergoing a transesophageal echocardiogram. Atrial appendage flow velocities were noted to be significantly decreased after conversion to sinus rhythm. Spontaneous contrast also developed in the left atrium shortly after conversion. Spontaneous cardioversion may be associated with decreased mechanical activity of the left atrium and appendage, resulting in "stunning." This provides a possible explanation for the occurrence of thromboembolic events in patients without apparent thrombus before cardioversion.     

Informationssysteme für „Wicked Problems“

The objective of this commentary is to propose fruitful research directions built upon the reciprocal interplay of social media and collective intelligence. We focus on ?wicked problems“ – a class of problems that Introne et al. (Künstl. Intell. 27:45–52, 2013) call ?problems for which no single computational formulation of the problem is sufficient, for which different stakeholders do not even agree on what the problem really is, and for which there are no right or wrong answers, only answers that are better or worse from different points of view“. We argue that information systems research in particular can aid in designing appropriate systems due to benefits derived from the combined perspectives of both social media and collective intelligence. We document the relevance and timeliness of social media and collective intelligence for business and information systems engineering, pinpoint needed functionality of information systems for wicked problems, describe related research challenges, highlight prospective suitable methods to tackle those challenges, and review examples of initial results.     

Value of acute rest sestamibi perfusion imaging for evaluation of patients admitted to the emergency department with chest pain

OBJECTIVES: This study sought to determine the ability of early perfusion imaging using technetium-99m sestamibi to predict adverse cardiac outcomes in patients who present to the emergency department with possible cardiac ischemia and nondiagnostic electrocardiograms (ECGs). BACKGROUND: Evaluation of patients presenting to the emergency department with possible acute coronary syndromes and nondiagnostic ECGs is problematic. Accurate risk stratification is necessary to prevent serious adverse outcomes. Initial results suggest that early perfusion imaging using technetium-99m sestamibi enables reliable risk stratification. METHODS: Patients presenting to the emergency department with a low to moderate probability of acute coronary syndromes underwent rapid sestamibi injection with gated single-photon emission computed tomographic imaging. Studies showing perfusion defects with associated wall motion abnormalities were considered positive. RESULTS: A total of 532 consecutive patients underwent serial myocardial marker analysis and rest perfusion imaging. Of these patients, perfusion imaging was positive in 171 (32%). Positive perfusion imaging was the only multivariate predictor of myocardial infarction (MI) (p < 0.0001, odds ratio [OR] 33, 95% confidence interval [CI] 7.7 to 141) and was the most important independent predictor of MI or revascularization (p < 0.0001, OR 14, 95% CI 7.3 to 25), followed by diabetes (p < 0.01, OR 2.8, 95% CI 1.5 to 5.1), typical angina (p = 0.01, OR 2.1, 95% CI 1.2 to 3.7) and male gender (p = 0.03, OR 1.9, 95% CI 1.1 to 3.5). The sensitivity of positive perfusion imaging for MI was 93% (95% CI 77% to 98%), and for MI or revascularization it was 81% (95% CI 71% to 88%), with negative predictive values of 99% (95% CI 98% to 100%) and 95% (95% CI 92% to 97%), respectively. CONCLUSIONS: Positive rest perfusion imaging accurately identified patients at high risk for adverse cardiac outcomes, whereas negative perfusion imaging identified a low risk patient group. Early perfusion imaging allows for rapid and accurate risk stratification of emergency department patients with possible cardiac ischemia and nondiagnostic ECGs.     

Ionic thermoplastic elastomer based on maleated epdm rubber. I. Effect of zinc stearate

Neutralization of maleated EPDM rubber by zinc oxide results in an ionic elastomer. The rate and extent of the neutralization reaction increase by addition of stearic acid. Although the rubber is not easy processable as such, incorporation of zinc stearate at a loading of 30 phr makes the rubber behave the rubber behave like a thermoplastic during high temperature (≥ 150°C) processing. Furthermore, zinc stearate causes improvement in the physical properties of the rubber under ambient conditions. It is believed that zinc stearate acts as a reinforcing filler under ambient conditions and as a plasticizer for the ionic domains at higher temperature (that is, above its melting point, 128°C). The conclusions are based on the results of dynamic mechanical, rheological, and infrared spectroscopic studies. © 1996 John Wiley & Sons, Inc.     

Andreev Bound States and Josephson Coupling in YBa2Cu3O7−δ/Pb tunnel junctions

We have made in-situ [103] and [110]YBCO/Pb junctions, which display an hysteretic behaviour with both a well-defined Quasi-Particule branch and a Josephson current. A zero energy conductance peak is observed in the tunneling conductance — which is a signature of Andreev Bound States (ABS) at a surface of a d-wave superconductor — which splits at low temperature. This may confirm the existence of a surface state which breaks time-reversal symmetry. However, up to now, we have not seen any evidence of a coupling between Josephson current and the zero-energy ABS, predicted by Y. Tanaka and S. Kashiwaya ¹ .