Researchers worldwide are taking advantage of novel, commercially available, technologies, such as ion mobility mass spectrometry (IM-MS), for metabolomics and lipidomics applications in a variety of fields including life, biomedical, and food sciences. IM-MS provides three main technical advantages over traditional LC-MS workflows. Firstly, in addition to mass, IM-MS allows collision cross-section values to be measured for metabolites and lipids, a physicochemical identifier related to the chemical shape of an analyte that increases the confidence of identification. Second, IM-MS increases peak capacity and the signal-to-noise, improving fingerprinting as well as quantification, and better defining the spatial localization of metabolites and lipids in biological and food samples. Third, IM-MS can be coupled with various fragmentation modes, adding new tools to improve structural characterization and molecular annotation. Here, we review the state-of-the-art in IM-MS technologies and approaches utilized to support metabolomics and lipidomics applications and we assess the challenges and opportunities in this growing field. 相似文献
Multidimensional Systems and Signal Processing - The applications of object-based image analysis (OBIA) in remote sensing studies have received a considerable amount of attention over the recent... 相似文献
The structural application of plywood boards has increased considerably in recent years. In this context, determining plywood mechanical properties such as bending strength and modulus of elasticity through predictive models using more-easily obtained properties is a very useful tool for in-factory quality control. Artificial neural networks have demonstrated their high capacity for modelling complex relations between variables, considerably improving on results obtained through regression techniques. Four neural networks were developed to obtain these mechanical properties by determining board thickness, moisture content, specific gravity, bending strength and modulus of elasticity of test pieces of small dimensions. The results were compared with those of a regression model and in all cases the results of the present study were better. 相似文献
The temperature gradient occurring for a short time during friction stir welding greatly affects the localized corrosion properties of welded 7050-T7451 plates. An immersion experiment in a salty solution was carried out in order to verify the influence of short-term post-weld heat treatments at temperatures similar to those taking place during friction stir welding on the corrosion behaviour of friction stir welded 7050-T7451. The experiment consisted of inserting thermocouples at different weld regions for the registration of the temperature development with time, and partially immersing the welded plate in a salty solution at 480 °C. In this manner, the weld experienced different temperature expositions at different locations. It was found that a temperature exposition above 180 °C for 20 min significantly increases the general corrosion resistance of friction stir welded 7050-T7451. The re-exposition of 7050-T7451 friction stir weld to a time–temperature combination similar to that occurring during the welding process on the thermomechanically heat affected zones of the weld, significantly improves the corrosion properties and the environmental cracking resistance. After the short-term temperature exposition, the fracture location of samples tested in a 3.5 wt.% NaCl solution moved from the corrosion susceptible thermomechanically affected zone to the heat affected zone. 相似文献
The antioxidant activity and nutritional components of Philippine salt-fermented shrimp paste were improved through prolonged fermentation (90, 180, and 360 days). The antioxidant ability against 1,1-diphenyl-2-picryhydrazyl (DPPH) radical, hydrogen peroxide, and lipid peroxidation increased significantly with prolonged fermentation and were suggested to be related with the Maillard reaction products formed, as measured by the characteristic browning and fluorescent developments. Polyunsaturated fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the shrimp paste were not substantially damaged for 360 days, while free amino acid content dramatically increased at 90 days. However, excessive fermentation showed slight but significant decrease in free amino acids and increase in ammonia. These results suggest that properly prolonged fermentation would improve antioxidant ability and some nutritional value in the salt-fermented shrimp paste. 相似文献
UWB technology is a useful and safe new technology in the area of wireless body area network. There are many advantages of
using UWB as a communication standard for biomedical applications. Due to very low radiated power (−41.3 dBm/MHz), low power
consumption, good coexistence with the other existing instruments, Robustness to interference and multipath. Moreover, one
specific UWB technology, namely Frequency Modulated (FM)-UWB, has also an important advantage, which make it even more convenient
for medical applications, such as simple low cost design (FM, no receive LO, no carrier synchronization as in IR-UWB). UWB
technology has been also proposed radar applications such as: Non-Invasive Heart and Respiration Rate Monitoring; Detection
of Cardiac Arrhythmias; Detection of Pathological Respiratory Patterns, particularly in Sudden Infant Death Syndrome (SIDS)
and Sleep Apnea; Multi-Patient Monitoring; Detection and Non-Invasive Imaging of Breast Tumors. However, pulsed radar are
mainly used for these applications. The main issue that is addressed in this paper is the integration of sensing and communication
using FM-UWB and radar technology so that a single device can be obtained for two different operational mode. We have show
that FM-UWB as radar can meet the requirements of typical biomedical applications such as Non-Invasive Heart and Respiration
Rate Monitoring. Advantages and challenges of this integration are shown. Future perspectives of this novel activity will
be drawn. 相似文献
Intermetallic particle electrochemistry plays significant role in localized corrosion and stress-corrosion cracking of aluminum
alloys. This article presents specific examples from recent and on-going studies of stress-corrosion cracking in Al-Mg alloys
and localized corrosion in Al-Cu alloys. The common approach in these examples is an explicit accounting of the intermetallic
particle-dissolution characteristics, which is developed by measuring the electrochemical behavior of bulk analog compounds.
Findings from these types of measurements combined with results from new and advanced small-length scale measurements confirm
some of the established ideas about localized corrosion in aluminum alloys, but also lead to new insights that are important
for a thorough understanding of corrosion damage accumulation.
For more information, contact R.G. Buchheit, The Ohio State University, Department of Materials Science and Engineering, 477
Watts Hall, 2041 College Road, Columbus, Ohio 43210; (614) 292-6085; fax (614) 292-9857; e-mail buchheit.8@osu.edu. 相似文献
Ablative materials represent a widespread solution for shielding space vehicles from overheating during a reentry phase in atmosphere where the high heating fluxes and the consequent high temperatures cannot be compatible with the vehicle structure and with the safety of the payload and/or the crew. In this work, two different kinds of carbon-phenolic ablators with a density of 0.3 g/cm3 were manufactured and their mechanical and thermal properties were experimentally evaluated. The thermal protection performances of the developed ablators were assessed in a hypersonic plasma wind tunnel facility, setting representative enthalpy and heat flux conditions (6 and 13 MW/m2), consistent with atmospheric reentry missions from high energy orbits. Data of the experimental tests were compared with the results obtained by a finite element model built up for these materials with the commercial software SAMCEF Amaryllis. All results enlighten the good performances of the ablators under severe heat flux conditions and outline their operating limits.
Percutaneous replacement of the pulmonary valve is a recently developed interventional technique which involves the implantation of a valved stent in the pulmonary trunk. It relies upon careful consideration of patient anatomy for both stent design and detailed procedure planning. Medical imaging data in the form of two-dimensional scans and three-dimensional interactive graphics offer only limited support for these tasks. The paper reports the results of an experimental investigation on the use of arterial models built by rapid prototyping techniques. An analysis of clinical needs has helped to specify proper requirements for such model properties as cost, strength, accuracy, elastic compliance, and optical transparency. Two different process chains, based on the fused deposition modelling technique and on the vacuum casting of thermoset resins in rubber moulds, have been tested for prototype fabrication. The use of anatomical models has allowed the cardiologist's confidence in patient selection, prosthesis fabrication, and final implantation to be significantly improved. 相似文献