Significantly reduced radiation dose to operators during percutaneous vertebroplasty using a new cement delivery device.

BACKGROUND: Percutaneous vertebroplasy (PVP) might lead to significant radiation exposure to patients, operators, and operating room personnel. Therefore, radiaton exposure is a concern. The aim of this study was to present a remote control cement delivery device and study whether it can reduce dose exposue to operators. METHODS: After meticulous preoperative preparation, a series of 40 osteoporosis patients were treated with unilateral approach PVP using the new cement delivery divice. We compared levels of fluoroscopic exposure to operator standing on different places during operation. group A: operator stood about 4 meters away from X-ray tube behind the lead sheet. group B: operator stood adjacent to patient as using conventional manual cement delivery device. RESULTS: During whole operation process, radiation dose to the operator (group A) was 0.10 ± 0.03 (0.07-0.15) µSv, group B was 12.09 ± 4.67 (10-20) µSv. a difference that was found to be statistically significant (P < 0.001) between group A and group B. CONCLUSION: New cement delivery device plus meticulous preoperative preparation can significantly decrease radiation dose to operators.

Zr(H2O)2EDTA modulated luminescent carbon dots as fluorescent probes for fluoride detection.

A novel fluorescent probe (Zr(CDs-COO)(2)EDTA) has been designed for fluoride ion (F(-)) content detection based on the competitive ligand reactions carried out between the carboxylate groups (-COOH) on the surface of the luminescent carbon dots (CDs) and F(-) coordinated to Zr(H(2)O)(2)EDTA. The strong and stable fluorescence signal of this probe was quenched upon the addition of F(-) as a result of the formation of the non-fluorescent complex Zr(F)(2)EDTA, due to the stronger affinity of F(-) than the -COOH in the CDs to Zr(IV). The fluorescence change (ΔF) in this process was linear with respect to the content of F(-), ranging from 0.10 µM to 10 µM. The probe has been applied to F(-) detection in toothpaste and water samples with satisfactory results. Moreover, the mechanism of this Zr(H(2)O)(2)EDTA modulated fluorescent probe for the detection of F(-) was also discussed.

Highly conductive and anti-freezing cellulose hydrogel for flexible sensors.

Ionic conducting hydrogels (ICHs) are emerging materials for multi-functional sensors in the fields of healthcare monitoring and flexible electronics. However, there is a long-standing dilemma between ionic conductivity and mechanical properties of the ICHs. In this work, ionic conductive, flexible, transparent, and anti-freezing hydrogels are fabricated by dissolving cotton linter pulp in ZnCl2/CaCl2 solution and cross-linking with epichlorohydrin (ECH). The presence of inorganic salt imparts the hydrogel with high ionic conductivity and low-temperature tolerance. While the introduction of ECH as the second network gives the hydrogel with desirable mechanical performance. By tailoring the ECH addition, the tensile strength, compressive strength, elongation at break, and conductivity of the hydrogel could reach 0.82 MPa, 2.80 MPa, 260 %, and 5.48 S m-1, respectively. The prepared ICHs are fabricated into sensors for detecting full-range human body motions, and they demonstrate fast response and durable sensitivity to both tensile strain and compressive deformation. Moreover, flexible sensors can work at subzero temperatures. This work provides a new idea for the preparation of cellulose-based hydrogels with good ionic conductivity and mechanical properties under extreme conditions.

Facile fabrication of strong and conductive cellulose hydrogels with wide temperature tolerance for flexible sensors.

Cellulose-based ionic conductive hydrogels (ICHs) have found extensive applications in flexible electronics and multifunctional sensors. However, simultaneous realization of sufficient conductivity, superior mechanical property and extreme environment tolerance for ICHs remains to be a huge challenge. In this work, a facile one-pot approach was developed to fabricate ICHs by directly dissolving cotton linter cellulose and polyvinyl alcohol (PVA) in a concentrated ZnCl2 solution. By regulating the content of PVA in ICHs, the optimal hydrogel (Gel-5) exhibits a tensile strength of 0.30 MPa, a compressive strength of 2.05 MPa and a conductivity of 8.16 S m-1. Moreover, the resulting dual-network ICHs present high transparency, good thermal reversibility and desirable ionic conductivity. Due to the high concentration of inorganic salts in the porous dual-network structure, the ICH presents good anti-drying and anti-freezing (as low as -90 °C) properties. Such hydrogel can be assembled into multi-functional sensors for human motion and temperature monitoring, and they demonstrate durable sensitivity, cycling stability in a wide operating temperature. This work will shed light on the design of cellulose-based hydrogels with good ionic conductivity and mechanical performance under extreme conditions.

Effects of polystyrene nanoplastics on the physiological and biochemical characteristics of microalga Scenedesmusquadricauda.

The contamination of the aquatic environment with microplastics has become a global environmental concern. Microplastic particles can be shredded to form smaller nanoplastics, and knowledge on their impacts on phytoplankton, especially freshwater microalgae, is still limited. To investigate this issue, the microalga Scenedesmus quadricauda was exposed to polystyrene nanoplastics (PS-NPs) of five concentrations (10, 25, 50, 100, and 200 mg/L). The growth; the contents of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD); the chlorophyll content; and concentrations of soluble protein and soluble polysaccharide were accordingly measured. The results showed that the microalgal density increased with the increase of the polystyrene nanoplastic concentrations, and the physiological features of alga were enhanced after the stimulation of nanoplastics. Furthermore, a high concentration (200 mg/L) of nanoplastics increased the contents of chlorophyll, soluble protein, and polysaccharide (P < 0.05). The antioxidant enzyme activities of Scenedesmus quadricauda were significantly activated by nanoplastics. Lastly, we propose three possible algal recovery mechanisms in response to nanoplastics in which Scenedesmus quadricauda was tolerant with PS-NPs by cell wall thickening, internalization, and aggregation. The results of this study contribute to understanding of the ecological risks of nanoplastics on freshwater microalgae.

Structure reorganization of cellulose hydrogel by green solvent exchange for potential plastic replacement.

Petroleum-based plastics have raised great environmental concerns from the beginning of their production to the end-of-life cycle. It is urgently needed to develop sustainable and green materials with certain plastic properties. Herein, biobased cellulose films are fabricated from low quality cotton cellulose by manipulating its hydrogen bonding network with green solvents. The cellulose is dispersed in inorganic salts (ZnCl2/CaCl2) to form ionic hydrogels, and then transformed into tough and flexible films through ethanol exchange and air drying. Without extra hot-pressing treatment, the aggregate structure of cellulose is re-organized with the disruption and re-construction of hydrogen bonds. Benefiting from the densely packed structure and highly in-plane orientation, the cellulose film presents outstanding optical, thermal and mechanical properties. Such cellulose materials hold a potential for plastic replacement in the field of biodegradable packing.

Lignocellulose hydrogels fabricated from corncob residues through a green solvent system.

It is still a challenge to find an effective solvent system that can simultaneously dissolve the cellulose and lignin in biomass residues to fabricate lignocellulose hydrogels (LHs). Herein, corncob residues from furfural production were pretreated with alkaline peroxide to regulate the lignin content. The lignin/cellulose composites with various lignin content were then dissolved and regenerated by a green and facile ZnCl2/CaCl2 solvent system. The inorganic salt solvents were served as linkers and flexible LHs were obtained. Substrate material containing 10.75% lignin shows the best compressive stress (76.71 kPa). Inspired by its superior ionic conductivity, the hydrogels were assembled into a solid-state electrolyte for a zinc-ion hybrid supercapacitor. This research develops a feasible, simple, and low-cost route for lignin-containing hydrogel preparation and offers insights into the high-value application of agro-industrial lignocellulosic wastes.

Metal nanoparticle-embedded bacterial cellulose aerogels via swelling-induced adsorption for nitrophenol reduction.

Bacterial cellulose aerogels were chosen as the substrate for supporting and dispersing metal nanoparticles (Cu and Ni). During the catalyst preparation, we found that the swelling-induced adsorption process could control the metal size and dispersion simultaneously. Cu and Ni nanoparticles were confined into the bacterial cellulose network and SEM results demonstrated that Cu particles had a smaller size compared to Ni particles. The metal-loaded catalysts exhibited good catalytic performance in the 4-nitrophenol reduction reaction. The optimal sample (BC-Cu-0.5) prepared with 0.5 wt% CuSO4 solution could complete the reduction process within 8 min. Besides, the BC-Cu-0.5 catalyst showed excellent stability and reusability. This study sheds light on the deposition of metal particles and provides a wider application for bacterial cellulose.

Health risk in children to fluoride exposure in a typical endemic fluorosis area on Loess Plateau, north China, in the last decade.

Excessive and inadequate intake of fluoride may cause adverse effects in children, such as dental caries and dental fluorosis. This study reports the results of monitoring fluoride concentrations in drinking water from an endemic fluorosis region during the ten-year period (2008 through 2017). The fluoride concentration had a range of 0.03-9.42 mg L-1 (mean = 0.55 ± 0.01 mg L-1). Approximately 10%, 1.3% and 0.06% children are at risk for dental decay, dental fluorosis and skeletal fluorosis, respectively. Probabilistic risks for children were assessed and the fluoride endemic areas were marked by GIS mapping system. On several water consumption points, the hazard quotient (HQ) values for children were higher than 1, indicating potential non-cancer health risks due to fluoride exposure. The results of this study will help governmental agencies to develop better policies for protecting children from exposure to fluoride.

A specific Tween-80-Rhodamine S-MWNTs phosphorescent reagent for the detection of trace calcitonin.

The present study proposed a simple sensitive and specific immunoassay for the quantification of calcitonin (CT) in human serum with water-soluble multi-walled carbon nanotubes (MWNTs). The COOH group of MWNTs could react with the NH group of rhodamine S (Rhod.S) molecules to form Rhod.S-MWNTs, which could emit room temperature phosphorescence (RTP) on acetate cellulose membrane (ACM) and react with Tween-80 to form micellar compound. Tween-80-Rhod.S-MWNTs (TRM), as a phosphorescent labelling reagent, could dramatically enhance the RTP signal of the system. The developed TRM phosphorescent reagent was used to label anti-calcitonin antibody (Ab(CT)) to form the TRM-Ab(CT) labelling product, which could take high specific immunoreaction with CT, and the ΔI(p) (= I(p2)-I(p1), I(p2) and I(p1) were the phosphorescence intensity of the test solution and the blank sample, respectively) of the system was linear to the content of CT. Hence, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) was established for the determination of CT in human serum. This sensitive (limit of quantification (LOQ) was 8.0×10(-14) g mL(-1)), accurate, selective and precise method has been applied to determine CT in human serum and predict primary osteoporosis and fractures, with the results in good agreement with those obtained by chemiluminescence immunoassay (CLIA). Simultaneously, the structure of MWNTs was characterized with scanning electron microscopy (SEM) and infrared spectroscopy (IR), and the reaction mechanisms of both labelling Ab(CT) with TRM and SSRTPIA for the determination of trace CT were discussed.