8 research outputs found
Thermal Conductivity of Composite Materials Containing Copper Nanowires
The development of thermal conductive polymer composite is necessary for the application in thermal management. In this paper, the experimental and theoretical investigations have been conducted to determine the effect of copper nanowires (CuNWs) and copper nanoparticles (CuNPs) on the thermal conductivity of dimethicone nanocomposites. The CuNWs and CuNPs were prepared by using a liquid phase reduction method, and they were characterized through scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experimental data show that the thermal conductivity of composites increases with the increase of filler. With the addition of 10 vol.% CuNWs, the thermal conductivity of the composite is 0.41 W/m/K. The normalized thermal conductivity enhancement factor is 2.73, much higher than that of the analogue containing CuNPs (1.67). These experimental data are in agreement with Nan’s model prediction. Due to the high aspect ratio of 1D CuNWs, they can construct thermal networks more effectively than CuNPs in the composite, resulting in higher thermal conductivity
Photosynthesis-assisted remodeling of three-dimensional printed structures
The mechanical properties of engineering structures continuously weaken during service life because of material fatigue or degradation. By contrast, living organisms are able to strengthen their mechanical properties by regenerating parts of their structures. For example, plants strengthen their cell structures by transforming photosynthesis-produced glucose into stiff polysaccharides. In this work, we realize hybrid materials that use photosynthesis of embedded chloroplasts to remodel their microstructures. These materials can be used to three-dimensionally (3D)-print functional structures, which are endowed with matrix-strengthening and crack healing when exposed to white light. The mechanism relies on a 3D-printable polymer that allows for an additional cross-linking reaction with photosynthesis-produced glucose in the material bulk or on the interface. The remodeling behavior can be suspended by freezing chloroplasts, regulated by mechanical preloads, and reversed by environmental cues. This work opens the door for the design of hybrid synthetic-living materials, for applications such as smart composites, lightweight structures, and soft robotics
Cleaner production of ammonium poly-vanadate by membrane electrolysis of sodium vanadate solution: The effect of membrane materials and electrode arrangements
In this study, we put forward a clean and complete process of V2O5 production from vanadiumcontaining solutions. It features membrane electrolysis for V/Na separation and AMV precipitation. With the aid of membrane electrolysis, the vanadium and sodium in the leaching solution can be directly separated using membrane-electrolysis. Meanwhile, the NaOH in the cathode chamber can also be recycled for vanadium slag decomposition. The electrolysis systems and membrane types have been investigated. It was found that 3-chamber electrolysis was much more energy efficient than the traditional 2-chamber electrolysis, while F8080 membrane showed a better separation efficiency than N117, CMI7000, LF0014 membrane. The main electrolysis parameters were also investigated, and it appeared that high current density and electrolyte temperature, as well as low initial cathodic NaOH concentration were beneficial for the separation efficiency. Under the optimum electrolysis conditions the electricity consumption of producing 750 kg V2O5 and 1000 kg NaOH and was 2151 kW h, with a current efficiency of 92.9%. During the vanadium precipitation process, NH4VO3 was used as precipitant for the first time, avoiding the introduction of impurity ions, such as Cl-, SO42- or Ca2+, realizing zero waste generation by source. A low-sodium medium product of (NH4)(2)V6O16 was precipitated at pH between 2 and 4. The commercial quality V2O5 product could be obtained by calcination and the ammonium slat was recycled for precipitation. This method can achieve the clean production of V2O5 with no wastewater or solid waste generated through the whole process. (C) 2019 Elsevier Ltd. All rights reserved
Testicular Transcriptome of Males and Pseudo-Males Provides Important New Insight into Sex Reversal of <i>Rana dybowskii</i>
Rana dybowskii (R. dybowskii) is an ecological species found in China, Japan, Korea, and Russia. Like most amphibians, R. dybowskii lacks heterotypic sex chromosomes, limiting the in-depth study of sex determination and sex reversal mechanisms. Previous studies have shown that certain environmental factors can modify R. dybowskii genotypic females into phenotypic males, but the mechanism is still unknown. Considering the difficulties in identifying and collecting sex reversal gonads at different stages of differentiation under natural conditions, testes from sexually mature wild adult R. dybowskii were taken in this study, and the genotypic sex of individuals and sex reversal were identified by two male-linked genetic markers reported in our most recent findings. Transcriptome sequencing was performed on testicular tissue from males and pseudo-males, as well as female ovary tissue. The results show that the gene expression patterns of pseudo-males’ testes were similar to those of the males but highly differed from females’ ovaries. One hundred and seventeen differentially expressed genes between testes of pseudo-males and males were found, and the up-regulation of doublesex and mab-3 related transcription factor 1 (Dmrt1) in testes of pseudo-males may play a key role in R. dybowskii sex reversal
Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL): A Novel Biomarker for Prognostic Assessment and Risk Stratification of Acute Pulmonary Embolism
Background: Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is associated with poor prognosis in cardiovascular diseases. However, the predictive value of TRAIL for the short-term outcome and risk stratification of acute pulmonary embolism (PE) remains unknown. Methods: This study prospectively included 151 normotensive patients with acute PE. The study outcome was a composite of 30-day adverse events, defined as PE-related death, shock, mechanical ventilation, cardiopulmonary resuscitation, and major bleeding. Results: Overall, nine of 151 (6.0%) patients experienced 30-day adverse composite events. Multivariable logistic regression showed that TRAIL was an independent predictor of study outcome (OR 0.19 per SD; 95% CI 0.04–0.90). An ROC curve revealed that TRAIL’s area under the curve (AUC) was 0.83 (95% CI 0.76–0.88). The optimal cut-off value for TRAIL was 18 pg/mL, with a sensitivity, specificity, negative predictive value, positive predictive value, positive likelihood ratio, and negative likelihood ratio of 89%, 69%, 99%, 15%, 2.87, and 0.16, respectively. Compared with the risk stratification algorithm outlined in the 2019 ESC guidelines, our biomarker-based risk stratification strategy (combining TRAIL and hs-cTnI) has a similar risk classification effect. Conclusion: Reduced plasma TRAIL levels predict short-term adverse events in normotensive patients with acute PE. The combination of the 2019 ESC algorithm and TRAIL aids risk stratification in normotensive patients with acute PE