Silicon nanowire piezoresistor and its applications: a review.

Monocrystalline bulk silicon with doped impurities has been the widely preferred piezoresistive material for the last few decades to realize micro-electromechanical system (MEMS) sensors. However, there has been a growing interest among researchers in the recent past to explore other piezoresistive materials with varied advantages in order to realize ultra-miniature high-sensitivity sensors for area-constrained applications. Of the various alternative piezoresistive materials, silicon nanowires (SiNWs) are an attractive choice due to their benefits of nanometre range dimensions, giant piezoresistive coefficients, and compatibility with the integrated circuit fabrication processes. This review article elucidates the fundamentals of piezoresistance and its existence in various materials, including silicon. It comprehends the piezoresistance effect in SiNWs based on two different biasing techniques, viz., (i) ungated and (ii) gated SiNWs. In addition, it presents the application of piezoresistive SiNWs in MEMS-based pressure sensors, acceleration sensors, flow sensors, resonators, and strain gauges.

Identification of Tibial Malrotation After Nailing Using Unique CT Scan Reference Line, and Influence of Position of Leg for Distal Locking on Rotation.

INTRODUCTION: Tibial torsion can be measured by various clinical and radiological methods. Computed tomography (CT) scan measurement is currently the investigation of choice. The purpose of our study was to compare the clinical and CT scan methods to reveal malrotation after nailing of tibia and also to find out if leg position for distal locking has any influence on incidence of malrotation. MATERIALS AND METHODS: We have included 106 patients (21-68 years) of tibia nailing, and categorised them as category A (figure of four position n = 54) and category B (knee straight position n = 52) based on limb position for distal locking. The plumb line measurement, Thigh Foot Axis (TFA) and CT scan measurement (using new reference line) were documented and compared with the uninjured limb. RESULTS: We observed plumb line measurement to be the most inaccurate method followed by TFA method. CT scan measurement was the most accurate method showing external rotations (> 10º) in 32 cases (30.1%) and internal rotation (> - 10º) in five cases (4.71%). The TFA method had a sensitivity of 44% and specificity of 86% in identifying malrotations. The interobserver reliability for CT scan measurement was 0.96. Even though statistically not significant (P value), figure of four position for distal locking leads to larger number of malrotations (both external and internal rotation). CONCLUSION: CT scan is the most accurate method of measuring malrotation. The new reference line used in our study provides accurate measurement of malrotation. The two different positions of leg for distal locking do not have a statistically significant influence on incidence of malrotation.

Understanding health care-seeking behaviour of the tribal population in India among those with presumptive TB symptoms.

BACKGROUND AND OBJECTIVES: Understanding the drivers for care-seeking among those who present with symptoms of TB is crucial for early diagnosis of TB and prompt treatment, which will in turn halt further TB transmission. While TB is a challenge among the tribal population, little is known about the care-seeking behaviour and the factors influencing care-seeking behaviour among the tribal population across India. METHODOLOGY: This community-based descriptive study was carried out in 17 states of India across 6 zones, covering 88 villages from tribal districts with over 70% tribal population. The sample population included individuals ≥15 years old who were screened through an interview for symptoms suggestive of pulmonary TB (PTB), currently and/or previously on anti-TB treatment. Those with symptoms were then assessed on their health-seeking behavior using a semi-structured interview schedule. RESULTS: Among 74532 eligible participants screened for symptoms suggestive of TB, 2675 (3.6%) were found to be presumptive TB cases. Of them, 659 (24.6%) sought care for their symptoms. While 48.2% sought care after a week, 19.3% sought care after one month or more, with no significant difference in the first point of care; 46.9% approaching a private and 46.7% a public facility. The significant factors influencing care-seeking behaviour were knowledge on TB (OR: 4.64 (3.70-5.83), p < 0.001), age<35 years (OR: 1.60 (1.28-2.00), p < 0.001), co-morbidities like asthma (OR: 1.80 (1.38-2.35), p < 0.001) and blood pressure (OR: 2.59 (1.75-3.85), p < 0.001), symptoms such as blood in sputum (OR: 1.69 (1.32-2.16), p < 0.001), shortness of breath (OR: 1.43 (1.19-1.72), p < 0.001) and weight loss (OR: 1.59 (1.33-1.89), p < 0.001). The cough was the most often reported symptom overall. There were gender differences in symptoms that prompted care-seeking: Males were more likely to seek care for weight loss (OR: 1.78 (1.42-2.23), p<0.001), blood in the sputum (OR: 1.69 (1.25-2.28), p<0.001), shortness of breath (OR: 1.49 (1.18-1.88), p<0.001) and fever (OR: 1.32 (1.05-1.65), p = 0.018). Females were more likely to seek care for blood in sputum (OR: 1.68 (1.10-2.58), p = 0.018) and shortness of breath (OR = 1.35, (1.01-1.82), p = 0.048). The cough did not feature as a significant symptom that prompted care-seeking. CONCLUSION: Delayed healthcare-seeking behaviour among those with symptoms presumptive of TB in the tribal population is a major concern. Findings point to differences across gender about symptoms that prompt care-seeking in this population. Gender-sensitive interventions with health system strengthening are urgently needed to facilitate early diagnosis and treatment among this population.