126 research outputs found

    Persistent Fluorescence-Assisted TiO<sub>2‑<i>x</i></sub>N<sub><i>y</i></sub>-Based Photocatalyst for Gaseous Acetaldehyde Degradation

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    Photocatalytic technologies were utilized to develop an environment-friendly system that is capable of removing and oxidizing organic pollutants from an air stream. A series of long-afterglow phosphors emitting long lifetime fluorescence was adapted to prepared TiO<sub>2</sub>-based composite photocatalysts for the photodegradation of gas-phase acetaldehyde. Although the photocatalytic reaction by an undoped titania (Degussa P25) was stopped immediately after turning off the irradiation light, the long-afterglow phosphor/nitorogen-doped TiO<sub>2</sub> (TiO<sub>2‑<i>x</i></sub>N<sub><i>y</i></sub>) composites maintained the acetaldehyde photodegradation ability even after turning off the light for a long time. This novel photocatalytic property may be attributed to the presence of the long-afterglow phosphor, which can reserve the light energy and generate the persistent fluorescence afterward as the light source for the photocatalytic reaction with the visible-light responsive TiO<sub>2‑<i>x</i></sub>N<sub><i>y</i></sub>. The substitution of the undoped TiO<sub>2</sub> with TiO<sub>2‑<i>x</i></sub>N<sub><i>y</i></sub> was essential to use the fluorescence as a light source for photocatalysis. Such a self-fluorescence-assisted system could enhance the performance of photocatalysts for environmental cleanup

    Additional file 1: of Visible Light-Driven Photocatalytic Activity of Oleic Acid-Coated TiO2 Nanoparticles Synthesized from Absolute Ethanol Solution

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    Supplementary information. Figure S1. XRD patterns of as-prepared samples by adding Sr source (SrCl2) into starting material (a) oleic acid-ethanol and (b) acetic acid-ethanol solutions with a large amount of Ti source. Figure S2. DeNOx abilities of different TiO2 samples. Figure S3. Crystalline morphology properties of nitrogen-doped TiO2 nanoparticles. Figure S4. DRS spectrum of nitrogen-doped TiO2 and P25 TiO2. Figure S5. DeNOx abilities of nitrogen-doped and TOS-TiO2 samples

    The Efficacy of Synchronous Combination of Chemotherapy and EGFR TKIs for the First-Line Treatment of NSCLC: A Systematic Analysis

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    <div><p>Background</p><p>The combination of chemotherapy and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) currently has become the hotspot issue in the treatment of non-small lung cancer (NSCLC). This systematic review was conducted to compare the efficacy and safety of the synchronous combination of these two treatments with EGFR TKIs or chemotherapy alone in advanced NSCLC.</p><p>Methods</p><p>EMBASE, PubMed, the Central Registry of Controlled Trials in the Cochrane Library (CENTRAL), Chinese biomedical literature database (CNKI) and meeting summaries were searched. The Phase II/III randomized controlled trials were selected by which patients with advanced NSCLC were randomized to receive a combination of EGFR TKIs and chemotherapy by synchronous mode vs. EGFR TKIs or chemotherapy alone.</p><p>Results</p><p>A total of six randomized controlled trials (RCTs) including 4675 patients were enrolled in the systematic review. The meta-analysis demonstrated that the synchronous combination group of chemotherapy and EGFR TKIs did not reach satisfactory results; there was no significant difference in overall survival (OS), time to progression (TTP) and objective response rate (ORR), compared with monotherapy (OS: HR = 1.05, 95%CI = 0.98–1.12; TTP: HR = 0.94, 95%CI = 0.89–1.00; ORR: RR = 1.07, 95%CI = 0.98–1.17), and no significant difference in OS and progression-free survival (PFS), compared with EGFR TKIs alone (OS: HR = 1.10, 95% CI = 0.83–1.46; PFS: HR = 0.86, 95% CI = 0.67–1.10). The patients who received synchronous combined therapy presented with increased incidences of grade 3/4 anemia (RR = 1.40, 95% CI = 1.10–1.79) and rash (RR = 7.43, 95% CI = 4.56–12.09), compared with chemotherapy, grade 3/4 anemia (RR = 6.71, 95% CI = 1.25–35.93) and fatigue (RR = 9.60, 95% CI = 2.28–40.86) compared with EGFR TKI monotherapy.</p><p>Conclusions</p><p>The synchronous combination of chemotherapy and TKIs is not superior to chemotherapy or EGFR TKIs alone for the first-line treatment of NSCLC.</p></div

    Effects of Composition and Melting Time on the Phase Separation of Poly(3-hydroxybutyrate)/Poly(propylene carbonate) Blend Thin Films

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    In this study, the effect of composition and melting time on the phase separation of poly­(3-hydroxybutyrate)/poly­(propylene carbonate) (PHB/PPC) blend thin films was investigated. Optical microscopy under phase contrast confirms the occurrence of phase separation of PHB/PPC blends at 190 °C. Polarized optical and scanning electron microscopies (POM and SEM) demonstrate that phase separation takes place along both horizontal and vertical film planes, which should be attributed to the two different interfaces and immiscible blends. A low PPC content (e.g. 30 wt %) results in the formation of compact PHB spherulites filling the whole space, whereas the noncrystallizable PPC spherical microdomains scatter in the PHB region, and their size shows a remarkable melting-time dependence. With the increasing PPC component and melting time, it is observed from POM that the separated PHB domains scattered in the continuous PPC phase, like the island structure. However, it can be revealed by SEM micrographs that the PHB thick domains are actually connected by its thin layer under the PPC layer. The real situation is, therefore, a large amount of PPC aggregates to the surface to form a network uplayer, whereas the PHB thick domains connected by its thin layer form a continuous PHB region, leading to a superimposed bilayer structure. There is also a small amount of PHB small domains scattered in the PHB phase. The PHB thick domains crystallize cooperatively with the PHB- or PHB-rich sublayer in a way just like the growth of pure PHB spherulites. This superimposed bilayer by interplay between phase separation and crystallization may provide availability to tailor the final structure and properties of crystalline/amorphous polymer blends

    Polymorphism and Enzymatic Degradation of Poly(1,4-butylene adipate) and Its Binary Blends with Atactic Poly(3-hydroxybutyrate) and Poly(vinyl phenol)

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    The influence of atactic poly­(3-hydroxybutyrate) (aPHB) and poly­(vinyl phenol) (PVPh) on the crystallization, phase transition, and enzymatic degradation behaviors of poly­(1,4-butylene adipate) (PBA) was studied. It was found that both aPHB and PVPh can lower the critical temperature of neat α-PBA crystallization from 34 °C for neat PBA to 32 °C for the blends. Also the critical temperatures of neat β-PBA crystallization decrease from 28 °C for neat PBA to 26 and 24 °C for the PBA/aPHB and PBA/PVPh, respectively. Moreover, the β-to-α phase transition can be accelerated by incorporation of PVPh and aPHB. The β-to-α phase transition completes at 55 °C during heating process for neat PBA, while the temperatures for a complete β-to-α transition of PBA in PBA/aPHB and PBA/PVPh are 50 and 45 °C, respectively. This result should be attributed to the decreasing melting point of PBA in its blends with aPHB or PVPh. Therefore, the melting of the original β-PBA and accompanied recrystallization into α ones should take place earlier and more quickly in the blends than that in neat PBA. The analysis of enzymatic degradation demonstrates that the degradation of PBA can be affected by crystalline morphology and the molecular chain mobility of PBA in the amorphous region. The restricted mobility of amorphous PBA imposed by aPHB and PVPh can slow down the degradation rate of PBA in the blends. The higher <i>T</i><sub>g</sub> and stronger intermolecular interaction between PVPh and PBA result in the slowest degradation of PBA in the PBA/PVPh blend. Furthermore, in neat PBA, PBA/PVPh, or PBA/aPHB, the degradation rate of α-PBA crystals obtained via annealing is slower than that of α-PBA prepared by isothermal crystallization and even slower than that of β-PBA

    Effect of Anodic Alumina Oxide Pore Diameter on the Crystallization of Poly(butylene adipate)

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    Poly­(butylene adipate) (PBA) was infiltrated into the anodic alumina oxide (AAO) templates with the pore diameter of around 30, 70, and 100 nm and PBA nanotubes with different diameters were prepared. The crystallization and phase transition behavior of the obtained PBA nanotubes capped in the nanopores have been explored by using X-ray diffraction and differential scanning calorimetry. Only α-PBA crystals form in the bulk sample during nonisothermal crystallization. By contrast, predominant β-PBA crystals form in the AAO templates. The β-PBA crystals formed in the nanopores with pore diameter less than 70 nm prefer to adopt an orientation with their <i>b</i>-axis parallel to the long axis of the pore. During the melt recrystallization, it was found that the critical temperature (<i>T</i><sub>β</sub>), below which pure β-crystals form, is 20 °C for bulk PBA. It drops down significantly with the pore diameter for the PBA in the AAO template. Moreover, the β-crystals in the porous template exhibit larger lattice parameters compared with the bulk crystals. By monitoring the change of β-crystals in the heating process, it was found that β-crystals in the AAO template with the pore diameter of 30 nm (D30) melt directly while the β-crystals transform to α-crystals in the template with the pore diameter of 100 nm (D100). The intensity of (020) Bragg peak of β-crystals decreases at a similar rate in both D30 and D100 but disappears at a relatively lower temperature in D30. On the other hand, the β(110) peak intensity of β-PBA crystals formed in the D100 template decreases first at slower rate before α crystals appear, and then at a faster rate once the β to α phase transition takes place

    Effects of Composition and Melting Time on the Phase Separation of Poly(3-hydroxybutyrate)/Poly(propylene carbonate) Blend Thin Films

    No full text
    In this study, the effect of composition and melting time on the phase separation of poly­(3-hydroxybutyrate)/poly­(propylene carbonate) (PHB/PPC) blend thin films was investigated. Optical microscopy under phase contrast confirms the occurrence of phase separation of PHB/PPC blends at 190 °C. Polarized optical and scanning electron microscopies (POM and SEM) demonstrate that phase separation takes place along both horizontal and vertical film planes, which should be attributed to the two different interfaces and immiscible blends. A low PPC content (e.g. 30 wt %) results in the formation of compact PHB spherulites filling the whole space, whereas the noncrystallizable PPC spherical microdomains scatter in the PHB region, and their size shows a remarkable melting-time dependence. With the increasing PPC component and melting time, it is observed from POM that the separated PHB domains scattered in the continuous PPC phase, like the island structure. However, it can be revealed by SEM micrographs that the PHB thick domains are actually connected by its thin layer under the PPC layer. The real situation is, therefore, a large amount of PPC aggregates to the surface to form a network uplayer, whereas the PHB thick domains connected by its thin layer form a continuous PHB region, leading to a superimposed bilayer structure. There is also a small amount of PHB small domains scattered in the PHB phase. The PHB thick domains crystallize cooperatively with the PHB- or PHB-rich sublayer in a way just like the growth of pure PHB spherulites. This superimposed bilayer by interplay between phase separation and crystallization may provide availability to tailor the final structure and properties of crystalline/amorphous polymer blends

    Effects of Composition and Melting Time on the Phase Separation of Poly(3-hydroxybutyrate)/Poly(propylene carbonate) Blend Thin Films

    No full text
    In this study, the effect of composition and melting time on the phase separation of poly­(3-hydroxybutyrate)/poly­(propylene carbonate) (PHB/PPC) blend thin films was investigated. Optical microscopy under phase contrast confirms the occurrence of phase separation of PHB/PPC blends at 190 °C. Polarized optical and scanning electron microscopies (POM and SEM) demonstrate that phase separation takes place along both horizontal and vertical film planes, which should be attributed to the two different interfaces and immiscible blends. A low PPC content (e.g. 30 wt %) results in the formation of compact PHB spherulites filling the whole space, whereas the noncrystallizable PPC spherical microdomains scatter in the PHB region, and their size shows a remarkable melting-time dependence. With the increasing PPC component and melting time, it is observed from POM that the separated PHB domains scattered in the continuous PPC phase, like the island structure. However, it can be revealed by SEM micrographs that the PHB thick domains are actually connected by its thin layer under the PPC layer. The real situation is, therefore, a large amount of PPC aggregates to the surface to form a network uplayer, whereas the PHB thick domains connected by its thin layer form a continuous PHB region, leading to a superimposed bilayer structure. There is also a small amount of PHB small domains scattered in the PHB phase. The PHB thick domains crystallize cooperatively with the PHB- or PHB-rich sublayer in a way just like the growth of pure PHB spherulites. This superimposed bilayer by interplay between phase separation and crystallization may provide availability to tailor the final structure and properties of crystalline/amorphous polymer blends
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