Magnetic field-guided orientation of carbon nanotubes through their conjugation with magnetic nanoparticles

Low intensity magnetic fields (22mT) rendered by a pair of bar magnets have been used to achieve in situ precise orientation of multiwalled carbon nanotubes (MWCNTs) and their directional deposition on solid substrates. The nanotubes were imparted magnetic characteristics through Fe₃O₄ (magnetite) nanoparticles covalently attached to their surface. The side walls of nanotubes were first acid oxidized with H₂SO₄/HNO₃ (3:1 v/v) mixture and amine-functionalized magnetic nanoparticles were then interfaced to ends and side walls of the nanotubes through covalent linkages in the presence of a zero length cross linker, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide. Fourier transformed infrared spectroscopic investigations affirmed the functionalization of nanostructures and formation of a magnetic nanohybrid. Transmission electron microscopy results revealed the attachment of nanoparticles along the side walls of MWCNTs. A flow cell was utilized to orient magnetic nanohybrid in the desired direction and also to create thin films of aligned MWCNTs. Further, directional assembly of magnetic MWCNTs at different orientation angles on solid substrates was studied by field emission scanning electron microscopy and optical microscopy. The procedure can be scaled to align CNTs on large surface areas for numerous applications, e.g., nanosensors, field emitters, and composites.     

Adaptive Neuro Fuzzy Inference System (ANFIS) based wildfire risk assessment

Wildfires are extremely destructive disasters that cause significant loss of lives, forest cover and wildlife. This is due to their uncontrolled, erratic, rapid spread and behaviour. The incidence of wildfires is expected to increase worldwide because of Global Warming. Henceforth, it becomes increasingly important to detect and tackle such fires in their infancy to minimise their adverse effects. IoT technology has shown an exponential growth in recent years. Moreover, deployment of IoT devices to monitor and collect time-critical data is pressing need of hour. This research proposes an effective Fog-IoT centric framework for timely detection of wildfires. The proposed methodology provides an efficient real-time solution to dilute the destruction caused by wildfires. Initially, K-means Clustering is used to detect the wildfire outbreak at fog layer followed by real-time alert generation to the administration and community. Furthermore, cloud layer based Adaptive Neuro Fuzzy Inference System is used for assessing the vulnerability of a forest block to forest fires as well as classifying it into one of the five risk zones based on Forest Fire Vulnerability Index. Implementation results of the proposed framework prove its efficiency in detecting and predicting wildfires. In addition, real-time alert generation further enhances the efficacy of the proposed system.     

Serum Calcium and the Risk of Breast Cancer: Findings from the Swedish AMORIS Study and a Meta-Analysis of Prospective Studies

To investigate the association between serum calcium and risk of breast cancer using a large cohort and a systematic review with meta-analysis. From the Swedish Apolipoprotein Mortality Risk (AMORIS) Study we included 229,674 women who had baseline measurements of serum total calcium and albumin. Multivariable Cox regression was used to assess the association between total and albumin-corrected calcium and breast cancer risk. For the systematic review, an electronic search of MEDLINE and EMBASE databases was performed to identify other prospective cohorts assessing the relationship between serum calcium and breast cancer risk. We pooled the results of our AMORIS cohort with other eligible studies in a meta-analysis using a random effects model. I² test was used to assess heterogeneity. In the AMORIS study, 10,863 women were diagnosed with breast cancer (mean follow-up: 19 years). We found an inverse association between total serum calcium and breast cancer when comparing the fourth quartile to the first quartile (HR: 0.94, 95% CI: 0.88–0.99, p value for trend 0.04) and similar results using albumin-corrected calcium. In the systematic review, we identified another two prospective cohorts evaluating pre-diagnostic serum total calcium and breast cancer. Combining these studies and our findings in AMORIS in a meta-analysis showed a protective effect of serum calcium against breast cancer, with a summary RR of 0.80 (95% CI: 0.66–0.97). No substantial heterogeneity was observed. Our findings in AMORIS and the meta-analysis support an inverse association between serum calcium and breast cancer risk, which warrants mechanistic investigations.     

陶瓷-熔融盐复合相变储能材料（英文）CSCD

研究了石墨材料包括纳米石墨对基于硝酸盐陶瓷复合相变储热材料性能的影响。其目的在于制备一种可用于集中式太阳能热发电(CSP)和工业废热回收(IWH)等应用的新型高温复合相变材料,并且使用导热增强物质(TCE)提升相变材料的导热性能。复合相变储热材料主要由硝酸钠(NaNO_3)相变材料,氧化镁(MgO)陶瓷基体,以及不同种类、不同比例的石墨导热增强剂组成。通过对复合材料的形态及热物理性质测定表明:不同种类的石墨导热增强剂对复合材料的导热性能影响不同,复合材料的储热密度随复合材料中相变材料比例的增加而增加。所得基于硝酸盐的陶瓷复合材料均可在500℃保持良好的热稳定性,因此其潜在应用包括工业废热回收及集中式太阳能热发电系统(CSP)等。     

Stabilization of horseradish peroxidase in silk materials

Horseradish peroxidase (HRP) is widely used as an indicator enzyme in enzyme immunoassays, enzyme electrodes, effluent treatment and synthetic organics. Previous studies showed that HRP was not stable in solution especially for low concentration solutions. It is important to prevent HRP from losing its activity. In the present study, we describe HRP stabilization in silk fibroin solution and in silk films. The results showed that HRP activity increased 30%―40% after being added into silk solution. The half-life time of HRP activity was 25 days at room temperature and 1h at 60°C in silk solution while it was only 2.5h at room temperature and 0.3h at 60°C in PBS buffer. The HRP activity in silk film still remained at 24%, 22%, 17%, when compared with the original amount of activity, after being immobilized in silk films stored at 4°C, room temperature and 37°C for 5 months, respectively. Electrostatic interactions and hydrophobic interactions between silk and HRP might account for this improved stabilization. Silk fibroin can be used as an HRP protecting reagent in solution and in films.