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The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines recommend the Royal Free Hospital-Nutritional Prioritizing Tool (RFH-NPT) to identify malnutrition risk in patients with liver disease. However, little is known about the application of the RFH-NPT to screen for the risk of malnutrition in China, where patients primarily suffer from hepatitis virus-related cirrhosis. A total of 155 cirrhosis patients without liver cancer or uncontrolled co-morbid illness were enrolled in this prospective study. We administered the Nutritional Risk Screening 2002 (NRS-2002), RFH-NPT, Malnutrition Universal Screening Tool (MUST) and Liver Disease Undernutrition Screening Tool (LDUST) to the patients within 24 h after admission and performed follow-up observations for 1·5 years. The RFH-NPT and NRS-2002 had higher sensitivities (64·8 and 52·4 %) and specificities (60 and 70 %) than the other tools with regard to screening for malnutrition risk in cirrhotic patients. The prevalence of nutritional risk was higher under the use of the RFH-NPT against the NRS-2002 (63 v. 51 %). The RFH-NPT tended more easily to detect malnutrition risk in patients with advanced Child–Pugh classes (B and C) and lower Model for End-stage Liver Disease scores (<15) compared with NRS-2002. RFH-NPT score was an independent predictive factor for mortality. Patients identified as being at high malnutrition risk with the RFH-NPT had a higher mortality rate than those at low risk; the same result was not obtained with the NRS-2002. Therefore, we suggest that using the RFH-NPT improves the ability of clinicians to predict malnutrition risk in patients with cirrhosis primarily caused by hepatitis virus infection at an earlier stage.
It is well-known that attention deficit hyperactivity disorder (ADHD) is associated with changes in the dopaminergic system. However, the relationship between central dopaminergic tone and the blood oxygen level-dependent (BOLD) signal during receipt of rewards and penalties in the corticostriatal pathway in adults with ADHD is unclear.
Single-photon emission computed tomography with [99mTC]TRODAT-1 was used to assess striatal dopamine transporter (DAT) availability. Event-related functional magnetic resonance imaging was conducted on subjects performing the Iowa Gambling Test.
DAT availability was found to be associated with the BOLD response, which was a covariate of monetary loss, in the medial prefrontal cortex (r = 0.55, P = .03), right ventral striatum (r = 0.69, P = .003), and right orbital frontal cortex (r = 0.53, P = .03) in adults with ADHD. However, a similar correlation was not found in the controls.
The results confirmed that dopaminergic tone may play a different role in the penalty-elicited response of adults with ADHD. It is plausible that a lower neuro-threshold accompanied by insensitivity to punishment could be exacerbated by the hypodopaminergic tone in ADHD.
Previous studies have indicated that there is dopamine transporter (DAT) dysregulation and P300 abnormality in adults with attention-deficit hyperactivity disorder (ADHD); however, the correlations among the three have not been fully explored.
A total of 11 adults (9 males and 2 females) with ADHD and 11 age-, sex-, and education-level-matched controls were recruited. We explored differences in DAT availability using single-photon emission computed tomography and P300 wave of event-related potentials between the two groups. The correlation between DAT availability and P300 performance was also examined.
DAT availability in the basal ganglia, caudate nucleus, and putamen was significantly lower in the ADHD group. Adults with ADHD had lower auditory P300 amplitudes at the Pz and Cz sites, as well as longer Fz latency than controls. DAT availability was negatively correlated to P300 latency at Pz and Fz.
Adults with ADHD had both abnormal DAT availability and P300 amplitude, suggesting that ADHD is linked to dysfunction of the central dopaminergic system and poor cognitive processes related to response selection and execution.
Following is a list of microscopy related meetings and courses. The editors would greatly appreciate input to this list via the electronic submission form found in the MSA World-Wide Web page at http://www.msa.microscopy.com. We will gladly add hypertext links to the notice on the web and insert a listing of the meeting in the next issue of the Journal. Send comments and questions to Nan Yao, nyao@Princeton.edu.
We investigated a cluster of postoperative febrile episodes and episodes of Acinetobacter baumannii bacteremia in obstetrics and gynecology wards after an electrical blackout and loss of the water supply. The use of patient-controlled analgesia was the only independent risk factor associated with postoperative fever, and A. baumannii isolates recovered from the blood of patients who had received patient-controlled analgesia were genetically related to an isolate recovered from the diluted morphine solution used for this procedure. After inappropriate preparation of the morphine solution was identified and stopped, the outbreak ended.
Traditional imaging of biological samples has been limited to the use of light microscopes, scanning electron microscopes (SEM), transmission electron microscopes (TEM), and atomic force microscopes (AFM). The information provided by these methods is limited, however, lacking the ability to fully characterize three-dimensional morphology and ultrastructure. Although SEM allows for an analysis of surface morphology, in order, however to study subsurface features complex sectioning must be performed outside of the sample chamber. TEM provides ultra-high resolution, but is unable to offer direct study of three-dimensional morphology. In an opposite manner, AFM provides high resolution in three dimensions, but is unable to reveal information concerning underlying ultrastructure. To overcome these shortcomings, researchers have turned to the focused ion beam (FIB). Traditional use of the FIB has been centered on specimen preparation as well as specimen analysis in the field of semiconductors and microcircuits. Capabilities of the focused ion beam/scanning electron microscope (FIB/SEM) system such as micro-sectioning and in-situ imaging provide an efficient method for failure analysis and repair of defective circuits. Furthermore, gas assisted etching of surface layers can reveal underlying circuitry in localized areas. Development of new techniques for the study of materials by FIB analysis is occurring at a greater frequency as ion beams gain in technical significance.
Despite the well-established use of FIB in the semiconductor field, application of FIB to the study of biological samples remains relatively uncommon [1–10]. Nonetheless, traditional techniques for analysis of traditional hard samples are also applicable to biological samples.
Ion implantation is a method for the direct, controlled introduction of impurities into solids. In ion implantation, a beam of dopant ions is aimed at a target material (the substrate) so that the ions are incident with sufficient energy to become permanently embedded. Because ion implantation is an essentially nonequilibrium process, it allows for the creation of concentration profiles that would be impossible to achieve using equilibrium techniques such as diffusion. The advent of focused ion beam (FIB) systems spawned a host of new applications for ion implantation. The ability to create high-resolution (feature sizes of order 10 nm [1, 2]) doping configurations without the use of a mask allows not only for rapid prototyping, but also for unique devices whose fabrication would not otherwise be feasible. FIB implantation has been used to make a wide variety of experimental devices including low-dimensional transistors, single photon detectors, subwavelength optics, and quantum computers.
This chapter covers the basics of ion implantation in general and of FIB implantation in particular. Next it considers the challenge of measuring the ion dose introduced into the substrate. It then discusses the major parameters relevant to the FIB implantation process and presents a sample of their complex interrelationships. Finally, it describes the aforementioned applications of FIB implantation to the fabrication of novel devices.
In the years since its development in the 1950s , ion implantation has become the preferred method for the introduction of impurities into solid substrates.
In the past few years, scientists have begun to gain the exquisite of controlling the arrangement of matter on the nanometer scale (1 nm = 10−9 m), a new field called nanotechnology, consequently, has started to emerge. As the foundation of nanotechnology, nanostructured materials take on an enormously richer variety of properties and promise exciting new advances in micromechanical, electronic, and magnetic devices as well as in molecular fabrications. The structure–composition–processing–property relationships for these sub-100 nm-sized materials can only be understood by employing the new generation microscopes such as the focused ion beam system in corporate with simultaneous operation of electron beam and in-situ analysis. This book will highlight the principles and vast capabilities of this technique and their applications in this fast-growing nanotechnology field and the challenges in the twenty-first century.
The focused ion beam (FIB) system is an important tool for understanding and manipulating the structure of materials at the nanoscale. Combining this system with an electron beam creates a DualBeam - a single system that can function as an imaging, analytical and sample modification tool. Presenting the principles, capabilities, challenges and applications of the FIB technique, this edited volume, first published in 2007, comprehensively covers the ion beam technology including the DualBeam. The basic principles of ion beam and two-beam systems, their interaction with materials, etching and deposition are all covered, as well as in situ materials characterization, sample preparation, three-dimensional reconstruction and applications in biomaterials and nanotechnology. With nanostructured materials becoming increasingly important in micromechanical, electronic and magnetic devices, this self-contained review of the range of ion beam methods, their advantages, and when best to implement them is a valuable resource for researchers in materials science, electrical engineering and nanotechnology.