Search

The nuclear protein poly(ADP-ribose) polymerases-1/2 (PARP-1/2) are involved in DNA repair damaged by endogenous or exogenous process. And PARP-1/2 inhibitors have been proved to be clinically efficacious for DNA repair deficient tumors in the past decade. We have developed a series of 4,5,6,7-tetrahydrothienopyridin-2-yl benzimidazole carboxamides as novel and potent PARP-1/2 inhibitors. The best compound resulted from this series is compound 27 which displays excellent PARP-1 and PARP-2 inhibitory activity with IC 50 of 18 nM and 42 nM, respectively. Furthermore, it can selectively kill BRCA2 deficient V-C8 cells with a CC 50 of 920 nM. In the MDA-MB-436 (BRCA-1 mutant) xenograft model, this compound was well tolerated and showed single-agent activity. Based on the results above, compound 27 has been selected as a lead candidate targeting PARP-1/2 and its preclinical characterization is also underway. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of ethylene under visible light remains a challenge at the frontiers of chemistry. In this study, In 2 O 3 -Ag-Ag 3 PO 4 composite semiconductors with Z-scheme configuration were fabricated for the first time by in-situ synthesis of Ag 3 PO 4 on In 2 O 3 and subsequent photoreduction of Ag 3 PO 4 to generate nano silver. Their performances on photocatalytic degradation of ethylene under visible light illumination were investigated. Results demonstrated that both the activity of ethylene photocatalytic degradation and Ag 3 PO 4 photostabilization are considerably improved by making such a Z-scheme composite. According to the material design perspective and the application in the field of environmental pollutant remediation, the present research will provide potential value for further study on the removal of HC (Hydrocarbons) from the atmosphere and the stability concern of Ag 3 PO 4 and other materials with photocorrosion. [ABSTRACT FROM AUTHOR]

Photocatalytic oxidation of ethylene continues to be a challenge at the frontier of chemistry. In a previous report, a simple Ag3PO4 semiconductor material was shown to have strong photooxidative properties and efficiently oxidised water and decomposed organics in aqueous solution under visible-light illumination. Herein, its effects on the photo-oxidation of gaseous C2H4 were investigated by fabricating graphitic C3N4-Ag3PO4 composite semiconductors with direct Z-scheme configuration. It was found that both the ethylene photo-oxidative activity and the stability of Ag3PO4 are considerably improved by fabrication of Z-scheme composites. Moreover, stable C2H4 photo-oxidation activity could be obtained by treating the composite at 450 °C for 3 h after long-term operation. From the point of view of environmental pollutant cleanup, the present technique avoids the side reaction of oxidising water and will be valuable for further investigations on both Ag3PO4 and CH degradation. [ABSTRACT FROM AUTHOR]

A concise palladium-catalyzed method for oxidative C–H/C–H cross-coupling between benzothiazoles and thiophenes/thiazoles has been developed. This CDC reaction is insensitive to air and moisture with high functional group tolerance. [ABSTRACT FROM AUTHOR]

Abstract: A green and efficient preparation of functionalized δ-carbolines/carbazoles via reductive ring closure by 1,2-bis(dipenylphosphino)ethane under solvent-free conditions is described. The starting materials 3-nitro-2-phenylpyridines/2-nitrobiphenyl derivatives are readily prepared through Suzuki–Miyaura cross-coupling reaction from commercially available compounds. And the polar by-product ethane-1,2-diylbis(diphenylphosphine oxide) is easily removed from the relatively polar reaction mixture. Various substituted δ-carbolines/carbazoles are obtained in acceptable yields. It is particularly worth mentioning that substrates with electron-withdrawing groups (EWG) also give the desired products in good yield. [Copyright &y& Elsevier]

Abstract: A triple sampling method to have enabled excellent channel uniformity and high in-band energy efficiency is firstly proposed for the design of an ultrahigh-channel-count fiber Bragg grating (FBG), which is based on the simultaneous utilization of two amplitude-assisted phase sampling (AAPS) functions and a phase-only sampling (POS) function. As an example, one linearly chirped FBG with consecutive 1215 channels enabling to cover all fiber telecom bands (O+E+S+C+L+U) is numerically demonstrated, which has a length of 9cm, a dispersion of −1360ps/nm, and a channel spacing of 50GHz. The maximum index-change required for 10dB strength of the FBG is less than 6×10−3. [Copyright &y& Elsevier]

30 examples [ABSTRACT FROM AUTHOR]

A facile one-pot two-step synthesis of functionalized indenones [cf. [ABSTRACT FROM AUTHOR]

Abstract: A novel optical fiber pressure sensor based on a Fabry–Perot (FP) interferometer and phase demodulation method is described. MEMS techniques and common communication devices are used to fabricate the sensor. The principle of pressure measurement has been introduced; the relationship between silicon membrane size and sensor performance has been simulated. A phase demodulation method based on a Fourier transformation is explored, which can reduce errors resulting from intensity variations of a light source. Experimental results demonstrate that the sensor has reasonable linearity, sensitivity, and a wide pressure measurement range from 0 to 3MPa. [Copyright &y& Elsevier]

• Cu oxide quantum dots were loaded on the exposed {0 0 1} facets of TiO 2 nanosheets. • The H 2 evolution rate reaches 18.39 mmol h−1 g−1 with ultra long term stability. • The interface interaction significantly enhanced the catalytic activity and stability. To simultaneously enhance both the hydrogen generation activity and long term stability of a TiO 2 based photocatalyst using Cu species as co-catalyst is a great challenge. In this work, highly reactive TiO 2 nanosheets with {0 0 1} facets were prepared by a hydrothermal method, and then Cu oxides quantum dot was loaded on the nanosheets by an impregnation method. Comprehensive analysis demonstrates that the Cu species change from CuO to Cu 2 O and partially to Cu during photocatalysis, and this process is reversed during oxidation. The exposed TiO 2 (0 0 1) planes provide a platform for a strong interaction between the Cu oxide and TiO 2 nanosheets, enabling the firmly anchor and charge transfer between the Cu oxide and TiO 2. The optimized composite photocatalyst shows a high efficiency and robust, long term stability for H 2 evolution. With simple O 2 regeneration, the H 2 generation rate maintains to 98% after irradiation for 30 h. It is expected that Cu 2 O is sandwiched between TiO 2 and CuO, and the composite configuration changes to TiO 2 /Cu 2 O/Cu after long term irradiation. The energy band alignment of the double heterojunction provides the effective charge separation and maintains the structural stability during the photocatalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoO was first used as C 2 H 4 degradation photocatalyst in this study. • A 0D/2D CoO QDs/Bi 2 MoO 6 monolayer S-scheme heterojunction is built. • This photocatalyst shows outstanding visible light activities for C 2 H 4 degradation. • The S-scheme heterojunction enhances the stability of CoO in photocatalytic reaction. • The S-scheme heterojunction could apply in fruit and vegetable preservation. As a plant hormone, C 2 H 4 causes significant economic losses during the storage and transportation of fruits and vegetables. How to efficiently photocatalytic oxidation of atmospheric C 2 H 4 using sun-light remains a significant challenge at the frontiers of chemistry. Inspired by natural photosynthesis of plant, here, we design a novel S-scheme heterojunction for highly efficient photocatalytic C 2 H 4 degradation. We first conducted density functional theory (DFT) calculations to predict an S-scheme heterojunction can be formed between CoO and Bi 2 MoO 6 , and then fabricated a novel CoO Quantum dots (QDs)/Bi 2 MoO 6 monolayer S-scheme heterojunction by using a practical hydrothermal approach to in-situ deposit CoO QDs on a Bi 2 MoO 6 monolayer. Furthermore, the UV–Vis DRS, UPS, in-situ XPS and electron spin resonance (ESR) characterization of DMPO-•O 2 – signals and DMPO-•OH signals evidence that the transfer pathway of space charge in photocatalytic degradation of ethylene accords with the S-scheme. Moreover, due to the unique structural design, CoO QDs and Bi 2 MoO 6 monolayer form an S-scheme heterojunction, and the intimate contact that enables efficient charge transfer and sufficient redox ability simultaneously, the CoO QDs/Bi 2 MoO 6 monolayer catalyst achieves a remarkable ethylene photocatalytic-degradation rate of 3.27 × 10−2∙min−1, 19.2 times higher than CoO and 22.5 times higher than Bi 2 MoO 6. This work provides novel insights for designing efficient S-scheme photocatalysts for C 2 H 4 degradation. [ABSTRACT FROM AUTHOR]

Making full use of photogenerated charge carriers by careful design multifunctional photocatalysts to achieving bi-value-added production with high-efficiency is highly desirable and extremely challenge. Herein, a novel 2D/3D ZnIn 2 S 4 @Ni 1 /UiO-66-NH 2 (ZIS@Ni 1 /UN) heterojunction with spatially separated and precise redox sites was designed and fabricated for both photocatalytic H 2 production and benzyl alcohol (BA) valorization. By precise structural regulation and modification of UiO-66 integrated with -NH 2 , ZnIn 2 S 4 (ZIS) and Ni single-atom, the spatial separation of redox sites and directional electron transfer has been achieved. This realizes collaborative and efficient solar energy to chemical energy conversion. The optimal sample 5ZIS@Ni 1 /UN-6 shows high photocatalytic H 2 and benzaldehyde (BAD) production rates of 11.44 mmol∙g−1∙h−1 and 10.02 mmol∙g−1∙h−1 under visible light. This work highlights the importance of rational construction for the engineering of charge behavior in heterogeneous photocatalysts with spatial separation and identifies their crucial role in promoting the photocatalytic redox coupling reactions. [Display omitted] • A novel 2D/3D ZnIn 2 S 4 @Ni 1 /UiO-66-NH 2 heterojunction is successfully design and fabricated. • High production rates of benzaldehyde and H 2 simultaneous is achieved under visible-light. • Precise construction of spatially separated redox-sites and directional electron transfer synergistically boost photocatalytic performance. • The carbon-centered free radical process of selective oxidation of benzylalcohol is confirmed by in-situ EPR. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel 0D/2D MoS 3 QDs/C-doped atomic-layer TiO 2 (B) nanosheet composite was fabricated. • The unique nanostructure exhibits remarkable performance for photocatalytic H 2 evolution. • MoS 3 exhibits a superior cocatalyst than MoS 2 and Pt for H 2 evolution and stability. Developing efficient photocatalysts for H 2 generation is of huge interest for sources of long-term sustainable energy. Here, a novel 0D/2D MoS 3 quantum dots (QDs)/C-doped atomically thin TiO 2 (B) nanosheet composite (MoS 3 /TiO 2 (B)-C) was fabricated for H 2 evolution. The simultaneous loading of the highly-efficient cocatalyst MoS 3 and carbon and oxygen vacancy co-doping into an atomically thin TiO 2 (B) nanosheet was achieved by an annealing process. This unique nanostructure of the MoS 3 /TiO 2 (B)-C exhibits remarkable photocatalysis of H 2 in the full spectrum. We obtain a yield of 2.47 mmol·g−1·h−1, 30 times higher than pure TiO 2 (B) nanosheet, and even higher than MoS 2 and Pt loaded TiO 2 (B) nanosheets (2.23 and 2.36 mmol·g−1·h−1, respectively). In-depth characterization shows that notably MoS 3 is a superior cocatalyst than MoS 2 for H 2 evolution and stability. We note MoS 2 is an earth-abundant robust cocatalyst previously recognized as an ideal substitute for Pt. Importantly, this research work also provides new insights for the design and practical manufacture of low-cost highly efficient H 2 generating photocatalysts by ultra-thin 2D materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ternary core–shell nanostructures were obtained by a facile and surfactant free method. • The resultant Pd-SNOF@SnO 2 shows efficient photoactivity for C 2 H 4 oxidation. • The core–shell structure can obviously improve the charge separation efficiency. A ternary core–shell structure composed of Sn 1.1 Nb 2 O 5.5 F 0.9 (SNOF), Pd nanoparticles, and the SnO 2 was fabricated by a facile one-step process at room temperature. In this structure, the SNOF nano-octahedrons were coated with thin layers of SnO 2 , and Pd nanoparticles were embedded in the SnO 2 matrix. The formation of SnO 2 and Pd nanomaterials was induced by the redox reaction between the reductive Sn2+ ions of the SNOF and the H 2 PdCl 4 solution. During this process, there are no organic species or foreign reducing agents involved. The as-obtained Pd-Sn 1.1 Nb 2 O 5.5 F 0.9 @SnO 2 (Pd-SNOF@SnO 2) nanocomposites showed efficient photoactivities for C 2 H 4 oxidation under simulated sunlight irradiation, which was significantly higher than that of the blank SNOF. The mineral ratio was determined to be ∼ 100%, and the catalyst was stable after five cycles. This result was ascribed to the core–shell structure of SNOF and SnO 2 as well as the embedded Pd nanoparticles functioning as an electron trapping site, which can effectively accept the photo-excited electrons. [ABSTRACT FROM AUTHOR]

Achieving efficient photocatalytic degradation of atmospheric volatile organic compounds (VOCs) under sun-light is still a significant challenge for environmental protection. The S-scheme heterojunction with its unique charge migration route, high charge separation rate and strong redox ability, has great potential. However, how to regulate interfacial charge transfer of the S-scheme heterojunction is of significant importance. Here, density functional theory (DFT) calculations were first conducted and predicted that an S-scheme heterojunction could be formed in the CdS quantum dots/Bi 2 MoO 6 monolayer system. Subsequently, this novel heterojunction is constructed by in-situ hydrothermal synthesis of CdS quantum dots on monolayer Bi 2 MoO 6. Under visible-light, this novel S-scheme system gives a high-efficiency photocatalytic degradation rate (6.04 × 10−2 min−1) towards C 2 H 4 , which is 30.3 times higher than that of pure CdS (1.99 × 10−3 min−1) and 41.7 times higher than pure Bi 2 MoO 6 (1.45 × 10−3 min−1). Strong evidence for the S-scheme charge transfer path is provided by in-situ XPS, PL, TRPL and EPR. [Display omitted] • A novel S-scheme CdS QDs/Bi 2 MoO 6 monolayer photocatalyst was synthesized. • This S-scheme heterojunction shows excellent activities for C 2 H 4 photodegradation. • The reaction mechanism of C 2 H 4 photooxidation was comprehensively investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Designed and fabricated a CdS QDs/Bi 2 WO 6 monolayer S-scheme heterojunction. • Bi-S bonds deliberately introduced at the interface to regulate the charge transfer. • S-scheme heterojunction show excellent photoactivities for C 2 H 4 oxidation. The S-scheme heterojunction with unique photogenerated electrons and holes migration pathway, excellent separation efficiency of photogenerated carrier and high redox potential, has great potential in this field of photocatalytic oxidation of atmospheric C 2 H 4. However, optimising the transfer of photogenerated charge at the S-scheme heterostructure interface continues to a major challenge. Here, density functional theory (DFT) calculations were first conducted to predict an S-scheme heterojunction can be formed in the CdS quantum dots (QDs)/Bi 2 WO 6 monolayer system, and then CdS QDs/Bi 2 WO 6 monolayer S-scheme heterojunction were constructed by in-situ hydrothermal synthesis of CdS QDs onto Bi 2 WO 6 monolayer. Bi-S bonds are deliberately introduced at the interface to maximise the photogenerated charge transfer. As expected, the substantial enhancement of the photocatalytic degradation of ethylene and the photostabilization of CdS is demonstrated. The S-scheme band alignment and the connected Bi-S coordination introduced at the junction interface allow highly efficient charge separation and an effective interfacial charge migration path. This research provides a basis for understanding the design of materials for the removal of hydrocarbons in air and environmental pollutant remediation, and improving the stability of sulfide and other photocatalysts to photocorrosion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) nanosheets are constructed. • The nanosheets exhibits a remarkable photothermal synergistic H 2 evolution rate. • Ti 0.5 Ru 0.5 O 2 shows much better co-catalytic ability compared to Ru and RuO 2. TiO 2 is an important material used in photocatalytic H 2 evolution. Here nanosheets with a Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) three-phase-junctions, composed of solid solution rutile phase Ti 0.5 Ru 0.5 O 2 , bronze phase TiO 2 (B), and anatase phase TiO 2 (A), are constructed via a hydrothermal method and subsequent calcination. At the optimal calcination temperature of 350 °C, the highest H 2 evolution rate reaches 27.817 mmol∙g−1∙h−1 at 25 °C, which is further increased up to 62.357 mmol∙g−1∙h−1 at 70 °C by synergistic photothermal catalysis. The photocatalytic activity of the optimized catalyst was further enhanced by loading with Pt as a co-catalyst. It is found that, in addition to helping charge separation, migration, and inhibiting the charge recombination, the three-phase-junctions structure is a key to present strong oxidation and reduction ability. Ti 0.5 Ru 0.5 O 2 solid solution has excellent co-catalytic ability, much better than Ru oxide, metallic Ru, as well as Pt. It works as hole acceptor, accelerating the generation and quench of photo induced peroxyl radicals, and thus significantly enhancing the H 2 generation rate. [ABSTRACT FROM AUTHOR]

Abstract: Data obtained from the newly installed MF radar at Langfang (39.4°N, 116.7°E), China, during the summer months of 2009 are used to study the short-term variability and summer averages of the mean wind and tidal oscillations in the mesosphere and lower thermosphere (MLT). Both the zonal and meridional daily winds between 80km and 98km show considerable day-to-day variability; their Lomb–Scargle spectra reveal active quasi-2-day and quasi-16-day planetary waves. The tidal large day-to-day variations have time scales of days or longer, which could be attributed to the contribution of planetary waves. The summer-averaged zonal wind is westward below 82km and eastward above 88km with the transition altitude at ∼85km. The meridional wind is dominated by the southward wind. The summer-averaged zonal and meridional semidiurnal tides exhibit amplitudes of 10–15m/s; they are larger than the diurnal tides, whose amplitudes are 5–10m/s. The phase tilt of the semidiurnal tide is downward, indicating this component is excited below the MLT. For the diurnal tide, the phase propagation is downward above 86km but it is upward below 86km, which indicates that the tide is evanescent or a mixture of evanescent and propagating modes. These wind and tide observations are compared with data from other mid-latitude stations at ∼40°N and with the HWM and GSWM models. Comparisons show that HWM-93 is better than HWM-07 in delineating the 2009 summer-averaged zonal wind over Langfang while both have systematic discrepancy in delineating the meridional mean winds. The prediction of the 2009 summer-averaged diurnal tide over Langfang by GSWM-09 is better than that from GSWM-02 but not the semidiurnal tide. [Copyright &y& Elsevier]

• We showed the photo-corrosion process of TiO 2 nanosheet. • Facile photo-deposition method in aqueous solution was used. • TiO 2 -Au-4h(PVP) displayed the highest QE of 30.9 % and best stability. • This method can be generally valid for other nanosheet photocatalyst. Though TiO 2 was famous for good chemical stability, as an ultrathin flaky structure, TiO 2 nanosheet also got mired in photo-corrosion. Herein, we explored the inner mechanism of photo-corrosion phenomenon among nanosheet structure, and demonstrated the vital role of high specific surface area and perfect dispersity of nanosheet photo-catalyst in H 2 evolution reaction, rather than the heterophase junction of TiO 2 (B)/λ-Ti 3 O 5. Through exploring four different Conditions, we have confirmed the important modification of highly active metal co-catalyst and surfactant PVP for greatly promoted catalytic efficiency and excellent morphology, efficiency stability. In especial, sole addition of PVP not only stabilized the nanosheet morphology, also tripled the original TiO 2 (B) efficiency, while TiO 2 -Au-4h(PVP) displayed the highest QE of 30.9 %, and best stability. This work developed an excellent stable TiO 2 (B) nanosheet based catalyst, also established a possible strategy to settle photocorrosion for other nanosheet mateials under illuminated applications. Active Au and PVP modified TiO 2 (B) showed excellent morphology, efficiency stability and greatly promoted hydrogen generation. Thereinto, Au helped to transfer photo-produced electrons to proton, while PVP linked to nanosheets effectively reduced their surface energy, and protected nanosheets from restacking. [Display omitted] [ABSTRACT FROM AUTHOR]

• Poto-deposited Hexagonal CdS/TiO 2 (B) shows visible light catalytic activity. • Hydrothermal fabricated Cubic CdS/TiO 2 (B) shows only UV light catalytic activity. • The photocorrosion resistance of CdS/TiO 2 (B) can be enhanced by PVP modification. A conventional TiO 2 photocatalyst cannot respond to visible light due to its large band gap. Here, we describe the construction of tandem CdS/TiO 2 (B) nanosheet architectures with visible light H 2 evolution. A type II heterojunction of hexagonal CdS/TiO 2 (B) (PCT) was constructed by photodeposition and CdS dots, with size about 6 nm, were anchored on TiO 2 (B) nanosheets. A second type I heterojunction of cubic CdS/TiO 2 (B) (HCT) was fabricated by a hydrothermal method and CdS nanoparticles, with size about 50 nm, were dispersed on TiO 2 (B) nanosheets. Both heterojunction systems display remarkable enhancement of H 2 evolution activity under full spectrum irradiation, with highest H 2 evolution rate of 1776 μmol·g−1·h−1 for the photodeposited catalyst and 1494 μmol·g−1·h−1 for the hydrothermal process. The different heterojunction systems show very different H 2 evolution under just visible light irradiation. The highest H 2 evolution (1577 μmol·g−1·h−1) for the type II system is far much higher than the type I (48 μmol·g−1·h−1). The type II system shows more effective utilization of full spectrum with the apparent quantum efficiency in the wavelength range extended from 300 to 500 nm, matching well with the optical absorbance spectrum of the composite catalyst. The structure, morphology, and photocatalytic mechanism of the CdS/TiO 2 (B) composites are discussed. [ABSTRACT FROM AUTHOR]

• 0D/2D Ni 2 P quantum dots/TiO 2 (B) nanosheets architecture was synthesized by a solvothermal method. • Photocatalytic H 2 evolution rate is superior to the noble metal Pt as cocatalyst. • The quantum efficiency of 10% Ni 2 P/TiO 2 (B) nanosheets is as high as 31% at 313 nm. • The H 2 production can be further enhanced 5 times by photothermal synergistic reaction at 90 °C. The development of low cost, stable, robust photocatalysts to convert solar energy into hydrogen energy is an important challenge. Here, we describe a simple solvothermal method to successfully fabricate a catalyst with a hybrid 0D/2D Ni 2 P quantum dot/TiO 2 (B) nanosheet architecture. HRTEM shows that Ni 2 P quantum dots about 5 nm in size were dispersed on ultrathin TiO 2 (B) nanosheets. The optimum photocatalytic H 2 evolution rate with 10 wt% Ni 2 P/TiO 2 (B) (3.966 mmol g−1 h−1) was superior to Pt loaded TiO 2 (B) (3.893 mmol h−1 g−1), which was 15 times higher than pure TiO 2 (B) nanosheets. Significantly, the new catalyst shows high stability and reusability in multiply cycled H 2 production runs for a 30 h period. The H 2 production rate can be considerably increased furthered by using synergistic photothermal H 2 evolution (20.129 mmol g−1 h−1 at 90 °C). [ABSTRACT FROM AUTHOR]