Investigation on Temperature Dependent Inductance (TDI) of a planar Multi-Layer Inductor (MLI) down to 4.2 K.

This paper presents an investigation of the temperature dependence characteristics specific to cryogenic planar Multi-Layer Inductors (MLIs). This paper establishes that the inductance of a planar MLI at a specific frequency varies with temperature when the sensor is cooled down to 4.2 K while providing a detailed analysis of various possible factors that might contribute to the variation in the sensor performance, such as the thermal deformation and the variation in the properties of sensor materials, using a combination of experiments and simulations. By calculating the interlayer capacitance, we have attempted to adopt a novel approach in the investigation of the effects of thermal deformation on the sensor. In order to arrive at that, the relative permittivity of the base material (G10CR-FR4) at cryogenic temperatures was obtained through experiments. The ANSYS static structural package was used for modeling thermally induced deformations, after which the deformed capacitance and inductance were obtained using Ansoft MAXWELL. From the analysis, we have concluded that the variation in the inductance of the sensor has a direct correlation with the electrical resistivity (hence the residual resistivity ratio) of the coil material. The number of inductor layers and the area of the component layer will also determine the temperature dependence phenomenon. These conclusions are not obvious from the established inductance models.

Clinical significance of preoperative serum interleukin-6 and C-reactive protein level in breast cancer patients.

BACKGROUND: Breast cancer is a disease that continues to plague females during their entire lifetime. IL-6 and CRP are found to be elevated in various inflammatory and malignant diseases and their levels are found to correlate with the extent of the disease. The primary objective of this study was to determine the preoperative serum levels of IL-6 and CRP in breast carcinoma, and to correlate them with the staging of the disease and the prognosis. METHODS: 59 female patients admitted for breast cancer were identified for the study and were subjected to thorough evaluation. Serum levels of IL-6 were assessed via Enzyme-Linked Immuno-Sorbent Assay (ELISA), and CRP was measured via immunoturbidimetry. Histological findings included tumour size, lymph node (LN) metastasis, and tumour staging. Relevant investigations were made to find out the presence of distant metastasis. Statistical analysis of the data was then processed. RESULTS: Increases in cancer invasion and staging are generally associated with increases in preoperative serum IL-6 levels. IL-6 and CRP levels correlated with LN metastasis (P < 0.001, P < 0.001) and TNM stage (P < 0.001, P < 0.001). Tumour invasion and the presence of distant metastasis is associated with higher IL-6 levels (P = 0.001, P = 0.009). When we established the cutoff value for IL-6 level (20.55 pg/dl) by ROC curve, we noted a significant difference in overall survival (OS; P = 0.008). However, CRP evidenced no significance with regard to patient's OS levels. Serum IL-6 levels were correlated positively with CRP levels (r² = 0.579, P < 0.01) CONCLUSION: Serum levels of IL-6 correlates well with the extent of tumor invasion, LN metastasis, distant metastasis and TNM staging thus enveloping all aspects of breast cancer.

ISSLS prize winner: a study of effects of in vivo mechanical forces on human lumbar discs with scoliotic disc as a biological model: results from serial postcontrast diffusion studies, histopathology and biochemical analysis of twenty-one human lumbar scoliotic discs.

STUDY DESIGN: A comprehensive study of 21 lumbar scoliotic discs by in vivo serial post contrast diffusion magnetic resonance imaging (MRI), histopathological, and biochemical analysis. OBJECTIVE: To investigate the in vivo effects of compressive and tensile mechanical stress on the lumbar discs with scoliotic disc as the biologic model. SUMMARY OF BACKGROUND DATA: Most studies implicating mechanical stress in degenerative disc disease (DDD) are on animals, in vitro conditions and cadavers. They are also restricted to histopathological or biochemical evaluation without analyzing the endplate (EP) and nucleus pulposus (NP) separately. The few human studies have not analyzed diffusion changes which is the final pathway for DDD. Adolescent scoliotic disc offer a perfect model to study the effects of mechanical stress. METHODS: Twenty-one discs from 6 patients with adolescent idiopathic scoliosis undergoing anterior corrective surgery were assessed before surgery by postcontrast MRI to document the EP diffusion patterns. The same discs harvested during surgery were analyzed histologically and biochemically. The results were correlated to clinical and radiologic parameters. RESULTS: Altered diffusion patterns was seen in all discs with site specific breaks in 2, double peak pattern in 3, high intensity pattern in 14, and frank contrast leak in 2. There was marked decrease in cell density and viability in all discs on both convex and concave sides compared to the control disc (P = 0.001). Neovascularization, calcification, and matrix degeneration were observed to varying extent in different regions of NP and EP. There was a decrease in water content with increasing severity of curves with significant difference between mild and severe curves (NP: P = 0.000, EP: P = 0.002). Lactate was significantly higher in caudal EP (P = 0.035) and discs with coronal migration of more than 15 mm (P = 0.007). Regression analysis showed that truncal decompensation was a main factor for decrease in cell density, matrix degeneration, calcification, and water content. CONCLUSION: The study documents widespread changes in the EP and NP even in discs with minimal wedging. EP damage and alterations in diffusion were observed earlier than MRI changes and could indicate nutritional factors as the primary mechanism of degeneration induced by mechanical stress. Degeneration was more severe in caudal discs and those with truncal decompensation. Its implications on the timing and choice of surgery in scoliosis are discussed.

Infrared thermal imaging for detection of peripheral vascular disorders.

Body temperature is a very useful parameter for diagnosing diseases. There is a definite correlation between body temperature and diseases. We have used Infrared Thermography to study noninvasive diagnosis of peripheral vascular diseases. Temperature gradients are observed in the affected regions of patients with vascular disorders, which indicate abnormal blood flow in the affected region. Thermal imaging results are well correlated with the clinical findings. Certain areas on the affected limbs show increased temperature profiles, probably due to inflammation and underlying venous flow changes. In general the temperature contrast in the affected regions is about 0.7 to 1 degrees C above the normal regions, due to sluggish blood circulation. The results suggest that the thermal imaging technique is an effective technique for detecting small temperature changes in the human body due to vascular disorders.

Assessment of bone mineral density by DXA and the trabecular microarchitecture of the calcaneum by texture analysis in pre- and postmenopausal women in the evaluation of osteoporosis.

The in vivo evaluation of trabecular bone structure could be useful in the diagnosis of osteoporosis for the characterization of therapeutic response and understanding the role of parameters other than bone mineral density (BMD) in defining skeletal status. This study was made to evaluate changes taking place in the trabecular architecture of bone with age and menopausal status in women. The findings are compared with the femoral neck bone as well as the trochantar bone mineral density determined by dual energy X-ray absorptiometry (DXA), which is a standard reference test for evaluation of osteoporosis. Seventy females were recruited for the study, 25 premenopausal (mean age ± SD: 39.4 ± 3.8) and 45 postmenopausal (mean age ± SD: 57.9 ± 7.9) women. The right femoral neck bone mineral density was measured for them by dual energy X-ray absorptiometry (DXA). For the same individuals, lateral view radiographs of the right calcaneum were taken as well. The radiographs were digitized and the region of interest (ROI) of 256 × 256 pixels was selected, the run length matrix was computed for calculating seven parameters [Table 1] and the two dimensional fast Fourier transform of the image was calculated. Using the FFT, the power spectral density (PSD) was derived and the root mean square (RMS) value was determined. Our results confirm that age has a significant influence on the texture of the trabecular bone and bone mineral density.