Bio-Inspired Aramid Fibers@silica Binary Synergistic Aerogels with High Thermal Insulation and Fire-Retardant Performance.

Flame-retardant, thermal insulation, mechanically robust, and comprehensive protection against extreme environmental threats aerogels are highly desirable for protective equipment. Herein, inspired by the core (organic)-shell (inorganic) structure of lobster antenna, fire-retardant and mechanically robust aramid fibers@silica nanocomposite aerogels with core-shell structures are fabricated via the sol-gel-film transformation and chemical vapor deposition process. The thickness of silica coating can be well-defined and controlled by the CVD time. Aramid fibers@silica nanocomposite aerogels show high heat resistance (530 °C), low thermal conductivity of 0.030 W·m-1·K-1, high tensile strength of 7.5 MPa and good flexibility. More importantly, aramid fibers@silica aerogels have high flame retardancy with limiting oxygen index 36.5. In addition, this material fabricated by the simple preparation process is believed to have potential application value in the field of aerospace or high-temperature thermal protection.

Differential diagnostic value of 18F-FDG PET/CT for benign and malignant vertebral compression fractures: comparison with magnetic resonance imaging.

PURPOSE: The purpose of this study was to evaluate the differential diagnostic value of 2-[fluorine-18]-fluoro-2-deoxy-d-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for benign and malignant vertebral compression fractures (VCFs), where the diagnostic accuracy of 18F-FDG PET/CT was compared with magnetic resonance imaging (MRI). PATIENTS AND METHODS: Between 2015 and 2017, we retrospectively evaluated 87 patients with 116 VCFs. MRI was performed in all the 87 patients, whereas 18F-FDG PET/CT was executed in 51 patients. Three malignant features (convex posterior cortex, epidural mass formation, and pedicle enhancement) from MRI and the maximum standardized uptake value (SUVmax) from 18F-FDG PET/CT were evaluated in benign and malignant VCFs, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI and 18F-FDG PET/CT were compared in the differentiation of malignant from benign VCFs. RESULTS: The results of our investigation showed that the sensitivity and specificity for predicting malignant VCFs were 75.6% and 77.3% for convex posterior cortex, 82.9% and 813% for epidural mass formation, and 85.7% and 70.8% for pedicle enhancement. 18F-FDG PET/CT demonstrated higher sensitivity (100%) but lower specificity (38.9%) as compared to MRI with regard to differentiation between benign and malignant VCFs. A significant difference in the SUVmax values was observed between the benign and malignant fractures (2.9 ± 1.0 vs 5.0 ± 1.8, P < 0.01). Besides the value of SUVmax, it has been noticed that the FDG uptake pattern differed in malignant and benign fractures. CONCLUSION: Significant MRI findings such as convex posterior cortex, epidural mass formation, and pedicle enhancement are highly suggestive of malignancy. 18F-FDG PET/CT reliably differentiated the fractures of malignant from benign based on both SUVmax and 18F-FDG uptake pattern. In a situation where MRI findings are not diagnostic, 18F-FDG PET/CT provides additional information as it has high sensitivity and is semiquantitative.

Pre-clinical study of a TNFR1-targeted 18F probe for PET imaging of breast cancer.

Tumor necrosis factor receptor 1 (TNFR1) is overexpressed in several varieties of carcinoma, including breast cancer. WH701 (Ala-Thr-Ala-Gln-Ser-Ala-Tyr-Gly), which was identified by phage display, can specifically bind to TNFR1. In this study, we labeled WH701 with 18F and investigated its tumor diagnostic value. WH701 was synthesized by standard Fmoc-solid phase synthetic protocols and conjugated by NOTA-NHS. NOTA-WH701 was radiolabeled with 18F using NOTA-AlF chelation reaction. The tumor target properties were evaluated in vitro and in vivo using MCF-7 xenografts and inflammation models. [18F]AlF-NOTA-WH701 was labeled in 25 min with a decay-corrected yield of 38.1 ± 4.8% (n = 5) and a specific activity of 10.4-13.0 GBq/µmol. WH701 had relatively high affinity for MCF-7 cells in vitro and [18F]AlF-NOTA-WH701 displayed relatively high tumor uptake in vivo. The tumor to muscle ratio was 4.25 ± 0.56 at 30 min post-injection (p.i.); further, there was a significant difference between the tumor/muscle and inflammation/muscle (3.22 ± 0.56) ratio, which could differentiate the tumor and inflammation. The tumor uptake of [18F]AlF-NOTA-WH701 could be inhibited by 71.1% by unlabeled WH701 at 30 min p.i. We have developed a promising PET tracer [18F]AlF-NOTA-WH701 for the noninvasive detection of breast cancer in vivo.

Effect of local mild hypothermia on regional cerebral blood flow in patients with acute intracerebral hemorrhage assessed by 99mTc-ECD SPECT imaging.

OBJECTIVE: This study aimed to observe the effect of local mild hypothermia on regional cerebral blood flow (rCBF) after acute intracerebral hemorrhage (ICH) and to evaluate its relation to clinical outcome in patients with ICH. METHODS: 36 CT proven ICH patients with Glasgow coma scale (GCS) score of 5 or more were randomly assigned to 2 group: local mild hypothermia with conventional mannitol (Group A) or conventional mannitol (Group B). SPECT study was performed at day 7 after therapy. The SPECT images were semi-quantitatively analyzed, and the radioactivity ratios of lesion to normal tissue (L/NT) were calculated. National Institutes of Health Stroke Scale (NIHSS) were used in evaluation at days 14 and 21 after therapy. RESULTS: There were significant differences in NIHSS score at days 14 and 21, and the L/NT ratios between the groups A and B (P < 0.05). Based on GCS, more patients in the group A showed favorable outcomes than patients in the group B (P < 0.05). Furthermore, the L/NT ratios significantly increased in patients with favorable outcomes compared to poor outcomes. Changes in NIHSS score at days 14 and 21 were closely negatively correlated with the L/NT ratios in the groups A and B (r= -0.58, -0.61, and -0.52, -0.75, respectively, P < 0.05). CONCLUSION: Local mild hypothermia could significantly increase rCBF and improve clinical outcome in ICH patients as evaluated by ^{99m}Tc-ECD SPECT study.

Adenosine stress thallium-201 myocardial perfusion imaging for detecting coronary artery disease at an early stage.

The aims of this study were to evaluate the diagnostic value of adenosine thallium-201 myocardial perfusion imaging and to compare it with exercise stress thallium-201 myocardial perfusion imaging for detecting coronary artery disease (CAD) at an early stage. Forty-one patients suspected with CAD were randomly divided into two groups. In Group 1 (n=21) adenosine stress was undertaken; the exercise stress myocardial perfusion imaging was performed in Group 2 (n=20). Coronary angiography (CAG) was performed in each patient within 2 weeks before or after single photon emission computed tomography (SPECT). Adenosine stress group vs. exercise stress group, the sensitivity was 92.86% vs. 100.0%, specificity 57.14% vs. 60.0%, positive predictive value 81.25% vs. 71.43%, negative predictive value 80.0% vs. 100.0%, accuracy 80.95% vs. 80.0% respectively. Detection rates of vessels of coronary artery lesions were 66.67% in Group 1 and 72.22% in Group 2 (P> 0.05). The side effects were mild and transient. Our results demonstrated that adenosine stress myocardial perfusion imaging is a safe and reliable diagnostic method for an early stage of CAD. As a comparative sensitivity and accuracy with exercise stress thallium-201 myocardial perfusion imaging, adenosine stress testing may provide a feasible alternative pharmacological stress method in myocardial SPECT for detection of CAD.