Magnetic Properties of Epitaxial Mn-doped ZnO Thin Films

Epitaxial ZnO thin film doped with 7% Mn have been made by reactive rf magnetron sputtering onto (1120) sapphire substrates at 400 °C. X-ray diffraction measurements reveal that the Zn0.93Mn0.07O film has a (0001) wurtzite single-crystal structure with a rocking curve width od 0.98°. UV-VIS absorption spectra show a band gap of 3.25 eV for pure ZnO films and 3.31 eV for the Zn0.93Mn0.07O film with states extending into the gap. The Auger electron spectroscopy shows homogeneous distribution of Mn in the film. The magnetic properties of the Zn0.93Mn0.07O film have been measured by a superconducting quantum interference device magnetometer at various temperatures with fields up to 5 T. No ferromagnetic ordering has been observed at temperature at 5 K. Instead, paramagnetic characteristics with a Curie-Weiss behavior have been observed

Magnetic Properties of One-Dimensional Quasiperiodic Co/Pt Multilayers

We have fabricated Fibonacci [Co/Pt] multilayers with two constituent Co/Pt bilayers, as well as periodic multilayers of the same Co/Pt bilayers, all of which exhibit perpendicular magnetic anisotropy. Magnetic properties of the quasiperiodic and periodic [Co/Pt] multilayers have been studied macroscopically by vibrating sample magnetometry and microscopically by magnetic force microscopy. The Fibonacci [CoPt] multilayers show enhanced squareness in magnetic hysteresis loops compared to the corresponding periodic [Co/Pt]n multilayers, due to a smaller density of isolated nucleation sites in the saturation state

Magnetic Properties of One-Dimensional Quasiperiodic Co/Pt Multilayers

We have fabricated Fibonacci [Co/Pt] multilayers with two constituent Co/Pt bilayers, as well as periodic multilayers of the same Co/Pt bilayers, all of which exhibit perpendicular magnetic anisotropy. Magnetic properties of the quasiperiodic and periodic [Co/Pt] multilayers have been studied macroscopically by vibrating sample magnetometry and microscopically by magnetic force microscopy. The Fibonacci [CoPt] multilayers show enhanced squareness in magnetic hysteresis loops compared to the corresponding periodic [Co/Pt]n multilayers, due to a smaller density of isolated nucleation sites in the saturation state

Computation of the optical properties of tissues from light reflectance using a neural network

We have established a neural network to quickly deduce optical properties of tissue slabs from the diffuse reflectance distribution. Diffusion theory based on multiple image sources mirrored about the two extrapolated boundaries is used to prepare the training and testing sets for the neural network. The neural network is trained using backpropagation with the conjugate gradient method. Once the neural network is trained, it is able to deduce optical properties of tissues within on the order of a millisecond. The range of the tissue optical properties that is covered by our neural network is 0.01 - 2 cm^(-1) for absorption coefficient, 5 - 25 cm^(-1) for reduced scattering coefficient, and 0.001 - 1 cm for tissue thickness. A separate network is also trained for thick tissue slabs. A simple experimental setup applying the trained neural network is designed to measure tissue optical properties quickly

Ultrasound-modulated optical tomography for thick tissue imaging

Continuous-wave ultrasonic modulation of scattered laser light has been used to image objects in tissue-simulating turbid media for the first time. We hypothesize that the ultrasound wave focused into the turbid media modulates the laser light passing through the ultrasonic focal spot. The modulated laser light collected by a photomultiplier tube reflects the local mechanical and optical properties in the focal zone. Buried objects in 5-cm thick tissue phantoms are located with millimeter resolution by scanning and detecting alterations of the ultrasound-modulated optical signal. Ultrasound-modulated optical tomography separates the conflict between signal and resolution in purely optical imaging of tissue and does not rely on ballistic or quasi-ballistic photons but on the abundant diffuse photons. The imaging resolution is determined by the focused ultrasonic wave. This technique has the potential to provide a noninvasive, nonionizing, inexpensive diagnostic tool for diseases such as breast cancer

Ultrasound-modulated optical tomography for dense turbid media

Continuous-wave ultrasonic modulation of scattered laser light has been used to image objects in tissue-simulating turbid media for the first time. We hypothesized that the ultrasound wave focused into the turbid media modulates the laser light passing through the ultrasonic focal zone. The modulated laser light collected by a photomultiplier tube reflects the local mechanical and optical properties in the focal zone. Buried objects in 5-cm thick tissue phantoms (absorption coefficient µ_a = 0.1 cm^(-1), reduced scattering coefficient µ_s' = 10 cm^(-1)) were located with millimeter resolution by scanning and detecting alterations of the ultrasound-modulated optical signal

Continuous-wave ultrasonic modulation of scattered laser light to image objects in turbid media

Continuous-wave ultrasonic modulation of scattered laser light has been used to image objects in tissue-simulating turbid media for what is to our knowledge the first time. The ultrasound wave focused into the turbid media modulates the laser light passing through the ultrasonic focal zone. The modulated laser light collected by a photomultiplier tube reflects the local mechanical and optical properties in the focal zone. Buried objects are located with millimeter resolution by scanning and detecting alterations of the modulated optical signal. This technique has the potential to provide a noninvasive, nonionizing, inexpensive diagnostic tool for diseases such as breast cancer

Comparison of the Health Aspects of Swimming With Other Types of Physical Activity and Sedentary Lifestyle Habits

Swimming, water jogging, and aqua aerobics may provide health benefits to the general population as well as patients with chronic diseases. Research on the health benefits of aquatic exercise in comparison with activities such as running and walking is scarce, however. The goal of this study was to evaluate characteristics of participants in the Aerobics Center Longitudinal Study and to compare health habits and physiological characteristics among swimmers, runners, walkers, and sedentary women and men in order to evaluate the health benefits of swimming compared to other types of physical activity. Participants were 10,518 women and 35,185 men ages 20-88 years who completed a health examination during 1970 and 2005. Differences in the distribution of selected characteristics between swimmers and those participating in other types of activities (sedentary, runners, or walkers) were tested using logistics regression for proportion and ANOVA for continuous variables. The principal findings of this report are that swimming, as well as walking and running, has health benefits compared with a sedentary lifestyle

Swimming and All-Cause Mortality Risk Compared With Running, Walking, and Sedentary Habits in Men

Swimming, water jogging, and aqua aerobics are lifetime physical activities that provide many health benefits comparable to those of walking and running. Research on the association between swimming and mortality is scarce, however. To evaluate the association between different types of physical activity and all-cause mortality, we studied 40,547 men age 20-90 years who completed a health examination during 1971 – 2003. Cox proportional-hazards regression was used to estimate the relative risks according to physical activity exposure categories. A total of 3,386 deaths occurred during 543,330 man-years of observation. After adjustment for age, body-mass index, smoking status, alcohol intake, and family history of cardiovascular disease, swimmers had 53%, 50%, and 49% lower all-cause mortality risks than did men who were sedentary, walkers, or runners, respectively (p \u3c 0.05 for each). Additional adjustment for baseline prevalent diseases did not change the inverse association between different activities and all-cause mortality. In conclusion, swimmers have lower mortality rates in comparison with those who were sedentary, walkers, and runners

Relationships of Clinical, Psychologic, and Individual Factors with the Functional Status of Neck Pain Patients

AbstractObjectiveThe objective of this study was to use both generic and disease-specific functional measures examining relationships of clinical, psychologic, and individual factors with the functional status of neck pain patients.MethodsPatients who visited a university-based spine clinic and reported neck pain were included in this study. A comprehensive computerized survey questionnaire was used to collect the information related to this study. The questionnaire also contained a generic measure, short form 12-item survey (SF-12), and a disease-specific measure, neck disability index (NDI). Correlation and multiple regression analysis were conducted to examine the relationships.ResultsA range of clinical, psychologic, and individual factors emerged to be significant predictors of the NDI or physical component of the SF-12 (PCS). The predictors of higher NDI included higher levels of neck pain, higher levels of back pain, higher levels of pain in arm or shoulder areas, not working, lower education, higher stress, the presence of depression or anxiety, and smoking. The predictors of lower PCS included not working, higher levels of back pain, higher levels of neck pain, lower education, female sex, the presence of cardiovascular disorders, the absence of cervical disk disorders, and older age.Conclusions The  predictors  of  the  NDI  or  PCS  appear to be multidimensional. Interventions designed to maximally improve the functional status of neck pain patients should be multifaceted and involve multidisciplinary teams. Selection of the most appropriate functional measures for an intervention study should consider differences between the generic and disease-specific measures in terms of their respective relationships with targeted factors. Prospective studies are needed to confirm the relationships observed in this study