MI Ratio Research Articles

Type I Diabetes Mellitus and Insulin Therapy on Bone Microarchitecture, Composition and Mechanical Properties

The aim of this study was to evaluate the microarchitecture, composition and mechanical properties of cortical bone of rats with type I diabetes mellitus (TIDM) and submitted to insulin therapy (IT). Thirty rats were divided into three groups (n=10): non-diabetic, diabetic and diabetic+insulin. TIDM was induced by intravenous injection of streptozotocin. In diabetic+insulin group, 4IU insulin was administered twice per day (1I U at 7 am and 3I U at 7 pm). The animals were euthanized five weeks after TIDM induction; the tibiae were removed and submitted to microcomputed tomography (micro-CT, 8 μm), fourier transform infrared spectroscopy (FTIR) and dynamic microhardness indentation. Micro-CT analysis showed that diabetic group had lower bone surface/tissue volume ratio (BS/BV) (p=0.018), cortical thickness (Ct.Th) (p<0.001) and degree of anisotropy (Ct.DA) (p=0.034) values compared to non-diabetic group. The diabetic group showed lower Ct.Th than diabetic + insulin group (p=0.018). The non-diabetic group had lower fractal dimension (Ct.FD) values compared to diabetic groups (p<0.001). The ATR-FTIR analyses showed lower values for all measured parameters in the diabetic group than the non-diabetic group (amide I ratio: p=0.046; crystallinity index: p=0.038; matrix:mineral ratios - M:MI: p=0.006; M:MIII: p=0.028). The diabetic+ insulin group showed a lower crystallinity index (p=0.022) and M:MI ratio (p=0.002) than nondiabetic and diabetic groups, respectively. The diabetic group showed lower Vickers hardness values than non-diabetic (p<0.001) and diabetic+insulin (p=0.003) groups. TIDM negatively affects bone microarchitecture, collagen maturation, mineralization and bone microhardness. Moreover, insulin minimized the effect of TIDM on cortical thickness and organic/mineral matrix.

Extensive Brain Pathologic Alterations Detected with 7.0-T MR Spectroscopic Imaging Associated with Disability in Multiple Sclerosis.

Background MR spectroscopic imaging (MRSI) allows in vivo assessment of brain metabolism and is of special interest in multiple sclerosis (MS), where morphologic MRI cannot depict major parts of disease activity. Purpose To evaluate the ability of 7.0-T MRSI to depict and visualize pathologic alterations in the normal-appearing white matter (NAWM) and cortical gray matter (CGM) in participants with MS and to investigate their relation to disability. Materials and Methods Free-induction decay MRSI was performed at 7.0 T. Participants with MS and age- and sex-matched healthy controls were recruited prospectively between January 2016 and December 2017. Metabolic ratios were obtained in white matter lesions, NAWM, and CGM regions. Subgroup analysis for MS-related disability based on Expanded Disability Status Scale (EDSS) scores was performed using analysis of covariance. Partial correlations were applied to explore associations between metabolic ratios and disability. Results Sixty-five participants with MS (mean age ± standard deviation, 34 years ± 9; 34 women) and 20 age- and sex-matched healthy controls (mean age, 32 years ± 7; 11 women) were evaluated. Higher signal intensity of myo-inositol (mI) with and without reduced signal intensity of N-acetylaspartate (NAA) was visible on metabolic images in the NAWM of participants with MS. A higher ratio of mI to total creatine (tCr) was observed in the NAWM of the centrum semiovale of all MS subgroups, including participants without disability (marginal mean ± standard error, healthy controls: 0.78 ± 0.04; EDSS 0-1: 0.86 ± 0.03 [P = .02]; EDSS 1.5-3: 0.95 ± 0.04 [P < .001]; EDSS ≥3.5: 0.94 ± 0.04 [P = .001]). A lower ratio of NAA to tCr was found in MS subgroups with disabilities, both in their NAWM (marginal mean ± standard error, healthy controls: 1.46 ± 0.04; EDSS 1.5-3: 1.33 ± 0.03 [P = .03]; EDSS ≥3.5: 1.30 ± 0.04 [P = .01]) and CGM (marginal mean ± standard error, healthy controls: 1.42 ± 0.05; EDSS ≥3.5: 1.23 ± 0.05 [P = .006]). mI/NAA correlated with EDSS (NAWM of centrum semiovale: r = 0.47, P < .001; parietal NAWM: r = 0.43, P = .002; frontal NAWM: r = 0.34, P = .01; frontal CGM: r = 0.37, P = .004). Conclusion MR spectroscopic imaging at 7.0 T allowed in vivo visualization of multiple sclerosis pathologic findings not visible at T1- or T2-weighted MRI. Metabolic abnormalities in the normal-appearing white matter and cortical gray matter were associated with disability. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Barker in this issue.

Магнитный импеданс пленочных наноструктур для оценки полей рассеяния микрочастиц магнитных композитов

Longitudinal giant magnetoimpedance effect of [Fe21Ni79/Cu]5/Cu/[Fe21Ni79/Cu]5 film element was investigated depends on stray magnetic field of epoxy magnetic composite with 30 % weight concentration of iron oxide magnetic microparticles. Configuration of an experiment was a model of thrombus detection in a blood vessel. Stray magnetic field was varied by movement of a magnetic composite above the element perpendicular to the long side. Composite was either magnetized or not to the state of remanence. As the magnetic composite approaches the GMI element, MI ratio curves are smoothed and shifted along the field axis and maximum value of the MI ratio decreases. Magnetic properties of magnetic composite and film element were investigated as well.

Magnetic impedance of film nanostructures for stray magnetic field evaluation of microparticles in magnetic composites

Longitudinal giant magnetoimpedance effect of [Fe21Ni79/Cu]5/Cu/[Fe21Ni79/Cu]5 film element was investigated depends on stray magnetic field of epoxy magnetic composite with 30% weight concentration of iron oxide magnetic microparticles. Configuration of an experiment was a model of thrombus detection in a blood vessel. Stray magnetic field was varied by movement of a magnetic composite above the element perpendicular to the long side. Composite was either magnetized or not to the state of remanence. As the magnetic composite approaches the GMI element, MI ratio curves are smoothed and shifted along the field axis and maximum value of the MI ratio decreases. Magnetic properties of magnetic composite and film element were investigated as well. Keywords: Magnetoimpedance effect, multilayered film nanostructures, composite materials, biodetection.

Effects of water deficit at different growth stages under drip irrigation on fruit quality of citrus in the humid areas of South China

Fruit quality as affected by water deficit applied at different growth stages remain largely elusive. Therefore, to evaluate the effects of deficit irrigation (DI) timing and degree under drip irrigation on fruit physical and chemical quality of citrus, the low (D15%), mild (D30%), moderate (D45%) and severe (D60%) water deficit treatments were set at the growth stage I, II, III and IV, respectively, with a control treatment (CK), during two growing seasons. The application of water deficit under drip irrigation at the early growth stage (stages I and II) had remarkable effects on physical quality of citrus. The I-D45% treatment increased the single fruit weight and firmness by 5.78−9.85% and 13.25−17.14%, respectively, and the II-D15% treatment improved them by 6.67−9.15% and 1.43−14.46%. The application of water deficit under drip irrigation at the middle growth stage (stage III) had remarkable effects on physical and chemical quality of citrus. There was no remarkable reduction in fruit physical quality under the III-D15% treatment, while the contents of fructose, glucose, sucrose, vitamin C (Vc), total soluble solids (TSS), and MI (TSS/TA (titratable acidity) ratio) were significantly increased by 12.95−17.67%, 9.26−17.84%, 7.90−19.65%, 9.10−29.20%, 7.68−15.96% and 18.07−29.19% (P < 0.05), respectively, and TA was reduced by 8.82−9.91%. The application of water deficit under drip irrigation at the late growth stage (stage IV) had remarkable effects on chemical quality of citrus. The IV-D30% treatment significantly increased the contents of fructose, glucose, sucrose, Vc, TSS and MI by 22.95−25.54%, 16.47−17.79%, 18.56−19.54%, 25.63−50.23%, 12.49−20.59%, and 18.87−24.47% (P < 0.05), respectively, while reduced TA by 3.60−5.88%. Therefore, I-D45% and II-D15% treatments significantly improved physical quality of citrus by saving about 178 and 154 m3/ha at stage I and II, respectively; III-D15% and IV-D30% treatments significantly increased chemical quality of citrus by saving about 635 and 782 m3/ha at stage III and IV, respectively, which was demonstrated as the suitable water deficit pattern. And this strategy had no significant effect on yield. Among all the treatments, the IV-D30% treatment improved the fruit quality of citrus most significantly.

Myo-Inositol Levels Measured with MR Spectroscopy Can Help Predict Failure of Antiangiogenic Treatment in Recurrent Glioblastoma.

Background Patients with recurrent glioblastoma (GBM) are often treated with antiangiogenic agents, such as bevacizumab (BEV). Despite therapeutic promise, conventional MRI methods fail to help determine which patients may not benefit from this treatment. Purpose To use MR spectroscopic imaging (MRSI) with intermediate and short echo time to measure corrected myo-inositol (mI)normalized by contralateral creatine (hereafter, mI/c-Cr) in participants with recurrent GBM treated with BEV and to investigate whether such measurements can help predict survivorship before BEV initiation (baseline) and at 1 day, 4 weeks, and 8 weeks thereafter. Materials and Methods In this prospective longitudinal study (2016-2020), spectroscopic data on mI-a glial marker and osmoregulator within the brain-normalized by contralateral creatine in the intratumoral, contralateral, and peritumoral volumes of patients with recurrent GBM were evaluated. Area under the receiver operating characteristic curve (AUC) was calculated for all volumes at baseline and 1 day, 4 weeks, and 8 weeks after treatment to determine the ability of mI/c-Cr to help predict survivorship. Results Twenty-one participants (median age ± standard deviation, 62 years ± 12; 15 men) were evaluated. Lower mI/c-Cr in the tumor before and during BEV treatment was predictive of poor survivorship, with receiver operating characteristic analyses showing an AUC of 0.75 at baseline, 0.87 at 1 day after treatment, and 1 at 8 weeks after. A similar result was observed in contralateral normal-appearing tissue and the peritumoral volume, with shorter-term survivors having lower levels of mI/c-Cr. In the contralateral volume, a lower ratio of mI to creatine (hereafter, mI/Cr) predicted shorter-term survival at baseline and all other time points. Within the peritumoral volume, lower mI/c-Cr levels were predictive of shorter-term survival at baseline (AUC, 0.80), at 1 day after treatment (AUC, 0.93), and at 4 weeks after treatment (AUC, 0.68). Conclusion Lower levels of myo-inositol normalized by contralateral creatine within intratumoral, contralateral, and peritumoral volumes were predictive of poor survivorship and antiangiogenic treatment failure as early as before bevacizumab treatment. Adapting MR spectroscopic imaging alongside conventional MRI modalities conveys critical information regarding the biologic characteristics of tumors to help better treat individuals with recurrent glioblastoma. Clinical trial registration no. NCT02843230 © RSNA, 2021 Online supplemental material is available for this article.

Magneto-impedance Effects in Electrodeposited Multi-layer [NiFe/Cu]3 on Cu Wire Substrates for kHz-order Frequency Measurements

The magneto-impedance effect (MI) in an electrodeposited multi-layered system of [NiFe/Cu]N on a Cu wire was modified by varying the thickness of the Cu spacer layer. The multi-layered samples of [NiFe/Cu]N were deposited by the electrodeposition using a platinum electrode. The MI ratio rapidly increased with a frequency of up to 100 kHz where it saturated. Conversely, the MI ratio of the multi-layered system [NiFe (800 nm)/Cu(y nm)]3 was a decreasing function of Cu layer thickness. The decreased MI ratio may be attributed to the lowered saturation magnetization in the multi-layered system with thicker spacer layers.

The Influence of AC Driving Current on Magnetoimpedance in [Ni80Fe20/Cu]x/Cu/[Ni80Fe20/Cu]6-x Multilayers

The phenomenon of magnetoimpedance in the multilayer configuration of [Ni80Fe20/Cu]x/Cu/[Ni80Fe20/Cu]6-x with x = 1, 2, and 3 has been successfully investigated. The electrodeposition method used for the multilayer film preparation on the meander pattered of Cu PCB. The obtained multilayer samples were evaluated the MI effect at room temperature with a frequency of 100 kHz. Here, the MI effects were evaluated for a variation of the AC driving current i.e. IAC = 4 mA, 8 mA, 12 mA, 16 mA, and 20 mA. The MI measurement results show that the multilayer x = 3 has the largest MI ratio and the multilayer with x = 1 was the smallest one. It is indicated that interlayer coupling contributes to the MI effect. Whereas the skin depth also confirms to contribute the MI ratio that showed the MI ratio increase with the increase of the I&lt;sub&gt;AC&lt;/sub&gt;.

Effect of multilayer structure parameters on magnetoimpedance ratio with low frequency measurements

The magneto-impedance of the NiFe thin films is experimentally dependent on their structure. The multilayer structures of [NiFe/Cu]&lt;sub&gt;4&lt;/sub&gt; and [NiFe/Cu]&lt;sub&gt;2&lt;/sub&gt;/Cu/[NiFe/Cu]&lt;sub&gt;2&lt;/sub&gt; on the &lt;em&gt;meander structure&lt;/em&gt; PCB Cu substrate in this study were deposited using the electrodeposition method. The frequency was varied in order to determine its effect on the magneto-impedance ratio. The results of the magneto-impedance characterization measurement showed that the maximum MI ratio in the multilayer [NiFe/Cu]&lt;sub&gt;4&lt;/sub&gt; structure was 6.82% while in [NiFe/Cu]&lt;sub&gt;2&lt;/sub&gt;/Cu/[NiFe/Cu]&lt;sub&gt;2&lt;/sub&gt; was 3.08% with a frequency of 100 kHz. The increase in the MI ratio in the low frequency range indicates that the MI ratio depends on the structure of the layer which is affected by the permeability of the magnetic material.

Statistical inference for estimating the incidence of cancer at the prefectural level in Japan.

Information of prefectural cancer incidence in Japan is an important resource to plan an effective regional cancer control program. In order to obtain accurate prefectural cancer incidence, we have to adjust for both of completeness of regional cancer registries and regional dispersion, simultaneously, Then, we developed a hierarchal Bayes model with a completeness adjustment by using the relation between MI ratio (mortality divided by incidence) and proportion of death certificate notified among incidence. Prefectural cancer incidence is estimated with the 95% credible interval, which suggests that the national MI ratio should be 0.386 if the registry were complete. Because cancer behavior has a variation depending on prefecture, such accurate incidence must contribute to plan and assess regional cancer control program.

Effects of Current Pulsation on Magnetic Properties and Giant Magnetoimpedance of Electrodeposited NiFe Coatings on Cu Wires

This work presents a systematic study of the effects of current pulsation on soft magnetic properties and giant magnetoimpedance (GMI) of nickel-iron (NiFe) coatings electrodeposited on copper wires. The specimens were prepared by the electrodeposition technique with controlled bath compositions and varied applied current waveforms. The microstructural and chemical investigations indicate that current pulsation with 50% duty cycle and 50 Hz frequency provides significantly smoother coating surface of uniform nodules, with comparable Fe content but different phase composition, as compared to the direct current condition. The vibrating sample magnetometer evidently shows that the deposits prepared with a pulsed current exhibit relatively small coercivity, below 4 Oe. Using the four-point probe technique, the MI ratio of the pulse deposits is found to reach a significantly high value above 2,000% with decent sensitivity. The benefits of current pulsation in improving the characteristics of NiFe deposits, and correspondingly the alloys’ soft magnetic properties and MI effects are demonstrated.

Brain amyloid burden and cerebrovascular disease are synergistically associated with neurometabolism in cognitively unimpaired older adults

Alzheimer's disease (AD) is the most common cause of cognitive dysfunction in older adults. The pathological hallmarks of AD such as beta amyloid (Aβ) aggregation and neurometabolic change, as indicated by altered myo-inositol (mI) and N-acetylaspartate (NAA) levels, typically precede the onset of cognitive dysfunction by years. Furthermore, cerebrovascular disease occurs early in AD, but the interplay between vascular and neurometabolic brain change is largely unknown. Thirty cognitively normal older adults (age = 70 ± 5.6 years, Mini-Mental State Examination = 29.2 ± 1) received 11-C-Pittsburgh Compound B positron emission tomography for estimating Aβ-plaque density, 7 Tesla fluid-attenuated inversion recovery magnetic resonance imaging for quantifying white matter hyperintensity volume as a marker of small vessel cerebrovascular disease and high-resolution magnetic resonance spectroscopic imaging at 7 Tesla, based on free induction decay acquisition localized by outer volume suppression to investigate tissue-specific neurometabolism in the posterior cingulate and precuneus. Aβ (β = 0.45, p = 0.018) and white matter hyperintensities (β = 0.40, p = 0.046) were independently and interactively (β = −0.49, p = 0.026) associated with a higher ratio of mI over NAA (mI/NAA) in the posterior cingulate and precuneus gray matter but not in the white matter. Our data suggest that cerebrovascular disease and Aβ burden are synergistically associated with AD-related gray matter neurometabolism in older adults.

Quality assessment and improvement of cancer registration system in Kamrup Urban District: A report.

The global burden of cancer incidence and mortality are rising continuously worldwide. As per the GLOBOCAN 2012 estimates, about 14.1 million cancer cases and 8.2 million cancer deaths occurred and 32.6 million people living with cancer (within 5 years of diagnosis) in 2012 worldwide. Reliable data on the magnitude and the pattern of cancer are essential for monitoring the health of the community, assessing the performance of the health care system. Cancer registries should pay great attention to quality of their data. The completeness of cancer registry data- the extent to which all of the incident cancers occurring in the population are included in the registry database- is an extremely important attribute of a cancer registry. There are mainly four aspects influencing the quality of data namely, comparability, completeness, validity and timeliness. Data regarding incidence and mortality with methods of diagnosis for individual years were obtained from the National Cancer Registry Program database of the Indian Council of Medical Research for 2009 to 2014 periods and recalculated for combined years (2009-2014). In males in 2009-11, 77.1% were microscopically confirmed cases which are improved in the later years and for the year 2012-2014, it is 81.4%. In females also the percentage of microscopically confirmed cases were increased from 80.2% to 82.9%. An improvement in mortality to incidence ratio was observed over the years. MI ratio in males was improved to 32.9%. for the year 2012-14 as compared to 28.6% for the year 2009-11 while in female MI ratio is also increased from 18.8% to 21.8% over the period from 2009-11 to 2012-14. Whereas DCO was decreased from 12% to 10.7% in males and 7.3% to 6.6% in females respectively from the period 2009-11 to 2012-14. Although there is a slight improvement in data quality till date, there is an enormous scope for population based cancer registry Guwahati to improve the data quality.

Improvement of cancer control in mainland China: epidemiological profiles during the 2004–10 National Cancer Prevention and Control Program

BackgroundFollowing the appeal of the World Health Assembly for national cancer plans and programmes, the Chinese Ministry of Health issued governmental outlines of the National Cancer Prevention and Control Programme (2004–10). This study aimed to evaluate the efficacy of that programme in mainland China. MethodsThe Chinese Ministry of Health outlines aimed to establish a national cancer registry system, enhance the population health education, and organise prevention, early detection, and early treatment for principal cancers, especially in rural areas for high-incidence cancers. We retrieved the crude incidence and mortality (per 100 000 people) in urban and rural areas from annual reports of the National Central Cancer Registry from 2004 to 2010. We estimated mortality index [MI=mortality/(incidence+mortality)] to represent the overall efficacy of screening and treatment for cancers. Trends of epidemiological profiles were observed over time. Only descriptive results are provided in this abstract, a statistical test was not performed. FindingsThe all-cancer incidence reached the peak at the 2008 and then decreased, whereas the all-cancer mortality changed accordingly. All-cancer incidence was higher in urban areas than in rural areas, but the urban MI was lower. The all-cancer MIs decreased more sharply in the rural population (from 43·2% to 39·8%) than in the urban population (from 38·8% to 37·8%), while rural-to-urban ratios of MI were decreased, especially among women (from 1·19 to 1·05). Lung, colorectal, and breast cancers were predominant among urban populations, whereas oesophageal, gastric, and liver cancers were predominant among the rural population. Particularly, rural-to-urban ratios of oesophageal cancer incidence and mortality were decreased from 3·73 to 1·65 for incidence and from 3·82 to 1·61 for mortality, but MIs never differed between rural and urban populations. The rural-to-urban ratio of MI for breast cancer was decreased from 1·47 to 1·08. InterpretationThe National Cancer Prevention and Control Programme (2004–10) obtained obvious achievement in narrowing the urban-rural gap of the worse cancer incidence or survival in the rural areas, especially for oesophageal and breast cancers respectively. However, the overall health burden from cancers is still heavy in mainland China and requires further governmental support to improve the cancer control. FundingNational Natural Science Foundation of China (81301866) and Outstanding Young Scientific Scholarship Foundation of Sichuan University, from the Fundamental Research Funds for the Central Universities of China (2015SCU04A43).

Magnetic properties and magnetoimpedance of short CuBe/CoFeNi electroplated microtubes

The magnetic properties and, particularly the magnetoimpedance, MI, of short CuBe/CoFeNi electroplated microtube, 0.9⬜1.7cm long, consisting of a CuBe metallic core surrounded by an electroplated ferromagnetic CoFeNi shell have been investigated with the final aim to be used as sensitive elements in sensor devices. From the analysis of the experimental hysteresis loops, we confirm the presence of a circular magnetic anisotropy of the ferromagnetic shell and the significant role of the inhomogeneous local distribution of the magnetization near the ends of the microtube.It is experimentally observed that the maximum MI ratio and its ohmic component depend very significantly on the microtube length while particularly the maximum value of the ohmic component is higher than that of the total MI ratio for all selected samples. These maxima are different from each other: the value of (ΝZ/Z)max, (ΝR/R)max, the MI sensitivity, and the value of the field in which each particular MI appears. Interesting MI behavior was observed in the low excitation frequency of 2.5MHz, where the length dependence of operation frequency was also studied.An optimal response is obtained for intermediate (critical) length sample with reduced border effect. This fact makes electroplated microtubes attractive for magnetic conditions devices and other applications.

Impact of ribbon width on magnetoimpedance and permeability of Fe69.2Co7.7Cu0.6Nb2.5Si11B9 soft magnetic alloy

Fe69.2Co7.7Cu0.6Nb2.5Si11B9 soft magnetic alloy ribbons of different widths, 4.4 and 8.0 mm respectively, were used for the research work. The influences of structural modifications induced by heat treatment on magnetoimpedance effect and permeability have been studied. In as quenched state and annealed at temperatures < 773 K, 4.4 mm wide ribbons showed larger MI values than the 8.0 mm wide ribbons. After being annealed at temperatures >823 K, the MI values of the 8.0 mm wide ribbons were slightly higher than those of 4.4 mm wide ribbons due to the improved soft magnetic properties. With controlled heat treatment at 853 K, a maximum MI ratio of 82% was detected for the 8.0 mm wide ribbon.

MRI findings of extranodal malignant lymphoma and squamous cell carcinoma in the head and neck regions

To compare magnetic resonance imaging (MRI) findings between patients with malignant lymphoma (ML) and squamous cell carcinoma (SCC) in the head and neck regions, and to show the characteristic findings for ML. We analyzed 10 lesions in nine patients with ML and 25 lesions in 25 patients with SCC. Diffusion-weighted imaging, T1-weighted imaging, and T2-weighted imaging were performed for all lesions. We estimated the apparent diffusion coefficients (ADCs) with b-factors of 0, 500, and 1000 s/mm2, and obtained the means and standard deviations. In 29 cases, dynamic contrast-enhanced MRI (DCE-MRI) was performed and time–intensity curves were obtained. The peak time, maximum-to-initial ratio (MI ratio), end-to-maximum ratio, and end-to-initial ratio (EI ratio) were estimated. Receiver-operating characteristic analyses were performed to estimate the diagnostic power for these indices. The mean ADC for ML (0.762 ± 0.126 × 10−3 mm2/s) was significantly lower than that for SCC (1.24 ± 0.22 × 10−3 mm2/s, p < 0.0001). ML had a smaller MI ratio (2.13 ± 0.26) and smaller EI ratio (1.90 ± 0.29) than SCC (MI ratio: 2.46 ± 0.38, p = 0.033; EI ratio: 2.19 ± 0.29, p = 0.025). The area under the curve for the mean ADC (0.989) was higher than those for the MI ratio (0.779) and EI ratio (0.792). The most characteristic findings for ML were extremely low ADCs. If the ADCs cannot be estimated because of severe susceptibility artifacts, DCE-MRI provides an alternative index for differentiating ML from SCC.

Association Between Physician Follow-Up and Outcomes of Care After Chest Pain Assessment in High-Risk Patients

Assessment of chest pain is one of the most common reasons for emergency department visits in developed countries. Although guidelines recommend primary care physician (PCP) follow-up for patients who are subsequently discharged, little is known about the relationship between physician follow-up and clinical outcomes. An observational study was conducted on patients with higher baseline risk, defined as having diabetes mellitus or established cardiovascular disease, who were evaluated for chest pain, discharged, and without adverse clinical outcomes for 30 days in Ontario from 2004 to 2010. Multivariable proportional hazard models were constructed to adjust for potential confounding between physician groups (cardiologist, PCP, or none). Among 56767 included patients, 17% were evaluated by cardiologists, 58% were evaluated by PCPs alone, and 25% had no physician follow-up. The mean age was 66±15 years, and 53% were male. The highest rates of diagnostic testing, medical therapy, and coronary revascularization were seen among patients treated by cardiologists. At 1 year, the rate of death or MI was 5.5% (95% confidence interval, 5.0-5.9) in the cardiology group, 7.7% (95% confidence interval, 7.4-7.9) in the PCP group, and 8.6% (95% confidence interval, 8.2-9.1) in the no-physician group. After adjustment, cardiologist follow-up was associated with significantly lower adjusted hazard ratio of death or MI compared with PCP (hazard ratio, 0.85; 95% confidence interval, 0.78-0.92) and no physician (hazard ratio, 0.79; 95% confidence interval, 0.71-0.88) follow-up. Among patients with higher baseline cardiovascular risk who were discharged from the emergency department after evaluation for chest pain in Ontario, follow-up with a cardiologist was associated with a decreased risk of all-cause mortality or hospitalization for MI at 1 year compared with follow-up with a PCP or no physician follow-up.

Magnetic and electric property evolution of amorphous cobalt-rich alloys driven by field annealing

Microstructure changes of the cross-section of Co-rich amorphous ribbons (Co68.15Fe4.35Si12.5B15, atomic%) annealed at 450 °C for 30 min with a zero field, a 10 Oe longitudinal external magnetic field or a 10 Oe transverse external magnetic field are investigated by comparing with as-spun ribbons. The ribbons annealed without a field, and under the transverse or longitudinal field exhibit different gradient microstructures along the cross-section of the ribbons, forming gradient amorphous–nanocrystalline (AN) composites different from the as-spun amorphous species. These kinds of AN composites preserve unique magnetic properties and enhanced conductivities when compared with the as-spun ribbons, leading to excellent giant magneto-impedance (GMI) effects. In particular, the AN composites prepared from the ribbons annealed under the longitudinal field lose the dual-peak feature shown by the as-spun ribbons but a mono-GMI peak appears, preserving a maximum MI ratio as high as 520% and a low magnetic field (0–1 Oe) sensitivity of 80% Oe−1 at 15 MHz and a maximum field of 40 Oe. The distinctly graded AN composites prepared from the ribbons annealed under the transverse field still preserve the dual-peak feature as the as-spun ribbons, having a maximum MI ratio of 320% and a significantly enhanced low magnetic field (0–1 Oe) sensitivity of 200% Oe−1 at 10 MHz and a maximum field of 40 Oe.

EFFECT OF ROTATING DIRECTION AND INTERVAL ON GIANT MAGNETO-IMPEDANCE OF SPUTTERED Ni80Fe20/Cu COMPOSITE WIRES

In this paper, a new method for fabricating Ni80Fe20/Cu composite wires is presented. A series of samples were prepared by alternating the rotating direction of the Cu wire during RF magnetron sputtering. In order to keep the overall coating thickness of all the samples constant, the alternating intervals and rotating period of each sample during sputtering were varied. As the rotating period increased, the samples showed different magneto-impedance profiles. Experimental results indicated that there was a critical thickness for single sputtered layer which the MI ratio was significantly enhanced at a relatively low driven current frequency. Qualitative discussion on these phenomena was explained in terms of exchange interaction and electromagnetic interactions.