Impact of Electron Acceptor on Three-Photon Absorption Cross-Section of the Fluorene Derivatives

Small three-photon absorption (3PA) cross-section values of present nonlinear organic molecules limit their practical applications. Although electron donors and electron acceptors have a great effect on 3PA cross-section, little is known about how the strength and situation of electron acceptors influence the 3PA cross-section value of a compound. The present work reports 3PA effects of two fluorene derivatives with symmetric D-π-π­(A)-π-D archetype, which are named as 2,7-bis­(4-methoxyphenylacetylene)-9-fluorenone (FATT) and 2,7-bis­(4-methoxyphenylacetylene)-9-thoine-fluorene (TSATL). Large 3PA cross-section and ideal 3PA-induced optical limiting effects have been found in the two fluorene derivatives. The two molecules both have a different electron acceptor on the fluorene core, by which the 3PA cross-section value for FATT is enhanced by nearly 3-fold compared with that for TSATL. The mechanism of this significant enhancement in 3PA cross-section has been investigated by density functional theory (DFT) and configuration interaction singles (CIS) method with use of 6-311+G basis set in combination with conductor polarizable continuum model (CPCM). The theoretical results show that increase of electronegative character of the electron acceptor on the core is responsible for the increase of 3PA cross-section values of the two molecules

Additional file 2: Table S2. of Comparative transcriptional profiling of orange fruit in response to the biocontrol yeast Kloeckera apiculata and its active compounds

List and MapMan analysis of differentially expressed genes in citrus in response to K. apiculata, the extract and phenylethanol, respectively. (XLS 264 kb

Preparation and Properties of CX (X: O, N, S) Based Distillable Ionic Liquids and Their Application for Rare Earth Separation

The negligible vapor pressure of ionic liquids prevents the separation of ionic liquids from other nonvolatile substances by distillation. Most distillable ionic liquids have been reported are protic ionic liquids, and the aprotic ionic liquids are still scarce. In this work, we designed and synthesized a series of unsaturated bond (CX; X is O, N, S) based ionic liquids and some of them could be distilled at a mild condition. Moreover, [MDMF]­TfO shows a high efficiency for separation of EuCl₃ from the mixture of EuCl₃ and NdCl₃

Organocatalytic Highly Enantioselective Monofluoroalkylation of 3‑Bromooxindoles: Construction of Fluorinated 3,3′-Disubstituted Oxindoles and Their Derivatives

A new practical organocatalytic asymmetric protocol for the introduction of a monofluoroalkyl group into the oxindole framework has been successfully developed. Excellent diastereoselectivities (>20:1 dr) and enantioselectivities (93–99% ee) of the products were obtained with a wide range of pre-electrophiles (3-bromooxindoles) and prenucleophiles (α-fluorinated β-keto <i>gem</i>-diols). The obtained products themselves and their derivatives may significantly benefit drug discovery

Base-Catalyzed Diastereoselective [3 + 3] Annulation of 3‑Isothiocyanatooxindoles and Azomethine Imines

An unprecedented diastereoselective [3 + 3] annulation of 3-isothiocyanatooxindoles and azomethine imines was catalyzed by Et₃N, affording 3,3′-triazinyl spirooxindoles in excellent yields and diastereoselectivities under mild conditions

Multi-timescale Thermal Network Model of Power Devices Based on POD Algorithm

The heat transfer of power devices has the characteristics of multi-timescale. However, the traditional thermal network model is difficult to predict the temperature information of power devices at multi-timescale accurately. This paper proposes a multi-timescale thermal network model for power devices, with MOSFET as an example. First, we establish a finite element model for temperature calculation of power devices and then reduce the order of the finite element model based on the proper orthogonal decomposition (POD) algorithm. The reduced order model is converted into an equivalent circuit model by the node voltage method and integrated into the circuit simulation software. To demonstrate its general applicability, this paper also establishes thermal network models for both IGBT and SiC MOSFET devices, validates the multi-time scale thermal network models through ANSYS/Transient Thermal software and experiments. The temperature calculation results of the three power devices all indicate that the proposed multi-time scale thermal network model can calculate the temperature of power devices faster than ANSYS/Transient Thermal model, and has less than 5% error under test conditions. This paper is accompanied by a video demonstrating a comparison of the computational speed of the multi-timescale thermal network model with a finite element model. Finally, a case study of junction temperature calculation in a Buck converter is presented to illustrate the application method of the thermal network model.</p

Antibacterial Adhesion of Borneol-Based Polymer via Surface Chiral Stereochemistry

During its adhesion on external surfaces, a cell exhibits obvious inclination to different molecular chirality, which encourages us to develop a new type of antibacterial material catering to the “chiral taste” of bacteria. On the basis of the natural product borneol (a camphane-type bicyclic monoterpene), a series of borneol-based polymer, polyborneolacrylate (PBA), was successfully prepared and showed superior antibacterial adhesion properties resulting from the borneol isomers on material surface. The results of this study reveal that bacteria simply dislike this type of stubborn surface of PBA, and the PBA surface stereochemistry contributes to the interfacial antibacterial activities. The PBA polymers were evaluated as noncytotoxic and can be simply synthesized, demonstrating their great potential for biomedical applications

Correction to Adaptive Chitosan Hollow Microspheres as Efficient Drug Carrier

Correction to Adaptive Chitosan Hollow Microspheres as Efficient Drug Carrie

Adaptive Chitosan Hollow Microspheres as Efficient Drug Carrier

Smart drug carrier with function-oriented adaptations is highly desired due to its unique properties in medical applications. Herein, adaptive chitosan hollow microspheres (CHM) are fabricated by employing interfacial Schiff-base bonding reaction. Hydrophilic macromolecules of glycol chitosan are fixed at the oil/water interface through numerous hydrophobic small molecules of borneol 4-formylbenzoate, forming the CHM with a positively charged surface and lipophilic cavity. These CHM have an average size of 400–1000 nm after passing through the 0.22 μm apertures of filter paper. This phenomenon combined with SEM measurements demonstrates its remarkable shape-adaptive behavior. Furthermore, the CHM present a pH-dependence of structural stability. When pH value reduces from 7.06 to 5.01, the CHM begin to lose their integrity. All those characteristics make the CHM an intelligent drug carrier, especially for water-insoluble anticancer drugs, paclitaxel (PTX) in particular. Both cell uptake and cell cytotoxicity assays suggest that the PTX-loaded CHM are highly efficient on HepG2 and A549 cells. Therefore, rather than most of the traditional materials, these adaptive CHM show great potential as a novel drug carrier

GSH/pH Cascade-Responsive Nanoparticles Eliminate Methicillin-Resistant Staphylococcus aureus Biofilm via Synergistic Photo-Chemo Therapy

Bacterial biofilm infection threatens public health, and efficient treatment strategies are urgently required. Phototherapy is a potential candidate, but it is limited because of the off-targeting property, vulnerable activity, and normal tissue damage. Herein, cascade-responsive nanoparticles (NPs) with a synergistic effect of phototherapy and chemotherapy are proposed for targeted elimination of biofilms. The NPs are fabricated by encapsulating IR780 in a polycarbonate-based polymer that contains disulfide bonds in the main chain and a Schiff-base bond connecting vancomycin (Van) pendants in the side chain (denoted as SP–Van@IR780 NPs). SP–Van@IR780 NPs specifically target bacterial biofilms in vitro and in vivo by the mediation of Van pendants. Subsequently, SP–Van@IR780 NPs are decomposed into small size and achieve deep biofilm penetration due to the cleavage of disulfide bonds in the presence of GSH. Thereafter, Van is then detached from the NPs because the Schiff base bonds are broken at low pH when SP@IR780 NPs penetrate into the interior of biofilm. The released Van and IR780 exhibit a robust synergistic effect of chemotherapy and phototherapy, strongly eliminate the biofilm both in vitro and in vivo. Therefore, these biocompatible SP–Van@IR780 NPs provide a new outlook for the therapy of bacterial biofilm infection