Failure analysis of a broken tooth

Several days after heart surgery, a patient discovered his upper right canine tooth had broken at the root. Such tooth damage, recognized post-operatively, is usually assumed to be caused by blunt mechanical force from an instrument used by the anesthesiologist during placement of a breathing tube at the start of surgery. In this case, the patient had saved the crown portion of the broken tooth, and it was possible to examine the root fracture characteristics. The curvature and direction of the crack path and natural tooth situation suggested that failure could be described through a cantilever beam model. This was confirmed when a whole extracted sample tooth was embedded and broken by a measured force in a manner consistent with the model. The resulting fracture surface matched that of the patient’s broken canine tooth. However, the high load and force direction necessary to fracture the root was inconsistent with forces applied during the anesthesia procedure. The failure analysis and further investigation indicated tooth clenching on the breathing tube during recovery was the likely cause of fracture. This paper presents an alternate explanation for intubation-related dental injury, demonstrates the practicality of fractographic analysis of biological materials, and introduces a methodology for simulating in vitro tooth settings for mechanical testing.     

The application of virtual reality technology in rehabilitation.

Virtual reality (VR) is an emerging technology with a variety of potential benefits for many aspects of rehabilitation assessment, treatment, and research. Through its capacity to allow the creation and control of dynamic 3-dimensional, ecologically valid stimulus environments within which behavioral responding can be recorded and measured, VR offers clinical assessment and rehabilitation options that are not available with traditional methods. Initial applications of VR in other aspects of medicine and psychology have yielded encouraging results, but continued research and understanding of this evolving technology will be crucial for its effective integration into rehabilitation. This article provides a brief introduction to VR technology, examines the specific benefits VR offers consumers and providers of rehabilitation services and discusses potential areas of application and important considerations in applying this technology. Finally, 2 examples of current Vr applications are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A small chip size 2 W, 62% efficient HBT MMIC for 3 V PCNapplications

This work describes the L-band low voltage (⩾1.6 V) power performance of AlGAs/GaAs heterojunction bipolar transistors (HBTs), their modeling and the design of a 2-W monolithic microwave integrated circuit (MMIC) for 3-V wireless mobile PCN applications (1800 MHz). The two-stage MMIC achieves 62% power-added efficiency (PAE) and 33 dB of linear gain, at a very small chip size of 1.2 mm². To our knowledge this is the best combination of power performance data for wireless applications demonstrated so far for a MMIC. The chip size is about a factor of four smaller than comparable MMIC's known before. The MMIC offers the potential both for low cost production due to small chip size, single voltage supply, and high performance at the same time     

Impaired delay eyeblink classical conditioning in individuals with anterograde amnesia resulting from anterior communicating artery aneurysm rupture.

Anterior communicating artery (ACoA) aneurysm rupture can lead to an anterograde amnesia syndrome similar to that observed after damage to the hippocampus and medial temporal lobes (MT). It is currently believed that ACoA amnesia results from basal forebrain damage that disrupts hippocampal processing without direct hippocampal damage. Converging evidence from animal studies and computational modeling suggests that qualitative differences may exist in the pattern of memory impairment after basal forebrain or MT damage. For example, animals with basal forebrain but not hippocampal damage are impaired at delay eyeblink classical conditioning (EBCC). In this study, individuals with ACoA amnesia were shown to be impaired at delay EBCC compared with matched controls; this contrasts with the spared delay EBCC previously observed in MT amnesia. This finding suggests the beginning of a possible dissociation between the memory impairments in MT versus ACoA amnesia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expected versus experienced neck comfort

There is certainly room for economy‐class travelers to make their trips more pleasant. A travel pillow might improve comfort. In this study, the comfort expectations and experience of travel pillows were examined. Comparing these 2 aspects indicated that it is not always possible to predict the comfort experience associated with a product based on a picture, and that there is a discrepancy between expected and experienced comfort. Experienced comfort is highest for travel pillows that restrict head movements in all directions in order to maintain a neutral posture. The results of this study also support earlier studies that suggested that discomfort experience can be predicted by observing the number of participants’ in‐seat movements; more movements result in higher experienced discomfort.     

Reel-to-reel wet coating as an efficient up-scaling technique for the production of bulk-heterojunction polymer solar cells

In this paper we report for the first time very promising results in up-scaling coating processes for thin flexible polymer solar cell (PSC) application. Two functional layers for PSC devices, the conducting poly- (3,4-ethylene-dioxythiophene):polystyrenesulfonate and the photoactive one (poly-3-hexylthiophene/[6,6]-phenyl-C61-butyric acid methyl ester), could be successfully prepared by continuous reel-to-reel (R2R) wet coating of low-viscosity solutions and dispersions on ITO-coated PET substrates. A laboratory coating machine (LBA-200) was used for R2R slot die coating (1-4 m/min). Out of this R2R-produced bilayer-system PSCs were accomplished and tested. Light power conversion efficiencies up to 1.7% under AM 1.5 illumination (100 mW/cm²) could be obtained.     

IPRA—ENHANCING THE SENSING ABILITIES OF AMBIENT INTELLIGENCE

The ability of ambient intelligence to serve a person could be considerably enhanced, if intelligent devices would take into account the person's current cognitive and affective state. One primary source for state information are physiological measures. However, obtaining state information requires concertedly employing a multitude of different techniques. To facilitate the use of physiological signals as sources of state information and thereby allow improving ambient intelligence, we developed Ipra , an integrated pattern recognition approach which (a) employs all techniques necessary to appropriately analyze physiological data, (b) is broadly applicable, and (c) is easy to use even for nonexperts. This approach together with results of its first application are presented in this contribution.     

Analysis of megadalton ions using cryodetection MALDI time-of-flight mass spectrometry

Presented are initial results from the first commercially available matrix-assisted laser desorption/ionization time-of-flight mass spectrometer specifically designed for the sensitive detection of very high mass ions (macromizer, Comet AG). This new instrument utilizes a 16-element superconducting tunnel junction detector coupled with a fully adjustable gimbal-mounted ion source/focusing region that allows unparalleled sensitivity for detection of singly charged high molecular weight ions. Using this new technology, the singly charged ions in the megadalton region are detected from immunoglobulin M and von Willebrand factor proteins. This detector technology also measures the kinetic energy of the particles impacting the detector, which can be correlated to the charge of the particles. Immunoglobulin G and streptavidin were used to demonstrate the ability of the macromizer instrument to detect high-mass ions and to discern the charge state of the ions.     

Algorithm 35 an algorithm for non-smoothing contour representations of two-dimensional arrays

The FORTRAN code calculates, plots and labels approximate contour linesz(x, y)=c for data that are given as a rectangular arrayz _ik =z(x _i ,y _k ).