Synergistic Effects of Selenophene and Extended Ladder-Type Donor Units for Efficient Polymer Solar Cells.

Two pairs of polymer donor materials based on indacenodithiophene (IDT) and indacenodithieno[3,2-b]thiophene (IDTT) as the donor units are synthesized. Thiophene or selenophene is introduced as the π-bridge units and electron-deficient fluorine-substituted quinoxaline is used as acceptor unit. Selenophene-containing polymers PIDT-DFQ-Se and PIDTT-DFQ-Se show redshifted absorption and narrower bandgaps. Combined with IDTT donor unit, PIDTT-DFQ-Se shows the highest absorption coefficient. Both the IDTT unit and selenophene unit have positive effects on the hole mobilities, making PIDTT-DFQ-Se the highest one. The best power conversion efficiency of 7.4% is obtained from devices based on PIDTT-DFQ-Se:[6,6]-phenyl C71 butyric acid methyl ester (PC71 BM) with a Jsc of 12.6 mA cm-2 , a Voc of 0.89 V, and a fill factor (FF) of 0.66.

The Influence of Oxygen Atoms on Conformation and π-π Stacking of Ladder-Type Donor-Based Polymers and Their Photovoltaic Properties.

A novel ladder-type donor pyran-bridged indacenodithiophene (IDTP) is developed by introducing two oxygen atoms into indacenodithiophene unit. IDTP possesses a twisted backbone and leads to facially asymmetric arrangement of side chains, resulting in enhanced local π-π stacking of according polymer poly[(5,5,11,11-tetrakis(4-octylphenyl)-5,11-dihydrothieno[2',3':5,6]pyrano[3,4-g]thieno[3,2-c]isochromene)-alt-4,7-(5-fluoro-2,1,3-benzothiadiazole)] (PIDTP)-FBT, which shows extended absorption range. Moreover, oxygen atoms render deeper highest occupied molecular orbital (HOMO) levels of poly[indacenodithiophene-alt-4,7-(5-fluoro-2,1,3-benzothiadiazole)] (PIDTP)-FBT compared with PIDT-FBT, therefore bringing a higher open-circuit voltage (Voc ).

Combination of polyvinylpolypyrrolidone extraction and standard addition strategy for the accurate determination of multiple allergen residues in red wine by UPLC-MS/MS.

During the winemaking process, fining materials derived from milk and egg products are traditionally used to remove undesirable substances to reduce bitterness and astringency. The possible residues of allergens in treated wine may pose a potential risk for allergy patients. In this study, we developed a method for the simultaneous quantification of eight allergens (αS1-casein, αS2-casein, ß-casein, κ-casein, ß-lactoglobulin, lysozyme, ovalbumin and ovotransferrin) in red wine by ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The sample was extracted with polyvinylpolypyrrolidone (PVPP) solution, following trypsin digestion and peptide-level purification by solid-phase extraction (SPE). A strategy based on standard addition was used for the accurate quantification of the target allergens in wine products. The limits of detection (LODs) were shown to be 0.003-0.015 µg/mL for milk allergens and 0.1 µg/mL for egg allergens. This economical and reliable method would be appropriate for routine analysis and further allergen label management for red wine.

Noninvasive In Vivo Imaging and Monitoring of 3D-Printed Polycaprolactone Scaffolds Labeled with an NIR Region II Fluorescent Dye.

Significant progress has been made in fabricating porous scaffolds with ultrafine fibers for tissue regeneration. However, the lack of noninvasive tracking methods in vivo makes it impossible to track the fate of such scaffolds in situ. The development of near-infrared region II (NIR-II, 1000-1700 nm) dyes provides the possibility of performing noninvasive visualization with deep-tissue penetration and high spatial resolution in vivo. Herein, we developed a polycaprolactone (PCL) ink containing the small organic NIR-II dye SY-1030 and the fluorescently labeled macromolecular dye SY-COO-PCL and fabricated high-resolution NIR-II active scaffolds via electrohydrodynamic jet (EHDJ) printing. All printed scaffolds subcutaneously implanted in mice were clearly imaged one week after the operation. Compared with scaffolds containing SY-1030, the fluorescence intensity emitted from scaffolds containing SY-COO-PCL can be tracked for up to three weeks. Moreover, the image quality can be optimized by adjusting the dye concentration, laser power, and exposure time. The advantage of such NIR-II active scaffolds is evidenced by the lower dye concentration, longer tracking period, and better in vivo stability. We also demonstrated the biocompatibility and biodegradability of the scaffolds containing SY-COO-PCL over a 3-month period. The developed NIR-II active scaffolds have potential applications in biopolymer implant tracking, tissue reconstruction monitoring, and target-position-based drug delivery.

[Clinical study of lumbar fusion by hybrid construct of stem cells technique and biodegradable material].

OBJECTIVE: To explorer the effectiveness of enriched bone marrow stem cells technique for lumbar fusion. METHODS: With the randomization and control principles, 2 graft materials [Enrichment bone marrow mesenchymal stem cells hybridized with beta-tri calcium phosphate (composite graft group), autologous iliac crest bone graft (autograft group)] were compared in posterior lumbar fusion procedures. 56 patients with degenerative disc disease, lumbar instability or spinal stenosis, were included. The volume of cells suspension in pre- and post-enrichment and the number of nucleated cells (NCs) were identified. The number of osteoprogenitor cells was estimated by counting the colony-forming units which express alkaline phosphatase (CFUs/ALP+). Then the efficiency of the enrichment was evaluated. Clinical follow-up with roentgenogram and Oswestry scale scores was performed for outcome evaluation. RESULTS: (249 +/- 31) ml bone marrow per patient from bilateral iliac crests was aspirated peri-operatively. About (43 +/- 11) ml enriched bone marrow was collected. The number of NCs was concentrated from (15.9 +/- 3.3) x 10(6)/ml to (44.1 +/- 10.8) x 10(6)/ml, CFUs/ALP+ was significantly increased from (118 +/- 86)/ml to(486 +/- 305)/ml. The follow-up was about (26.3 +/- 7.5) months. There was no significant differences in age, gender, disease and fusion segments between the two groups. The fusion rate was 93.3% and 96.2% for composite graft group and autograft group, respectively (chi2 = 0.2146, P = 0.6432). There was no difference in operation time between the two group (t = 0.5243, P = 0.6022), but blood loss in composite graft group was more than that in autograft group (t = 6.4664, P < 0.01). Cell salvage for auto-transfusion could transfuse back half of the blood loss during operation. No hematoma or chronic soreness in the bone marrow donor sites of composite graft group occurred, but a little exudation or moderate swelling in the wound happened in 4 cases which disappeared under medical treatment. Meanwhile, 15.4% patients had hematoma in the iliac bone donor site and 26.9% patients had chronic soreness, but no case had wound problem in autograft group. As for Oswestry scale scores, there was no significant difference between the two groups. CONCLUSIONS: The enrichment technique of autologous bone marrow stem cells can greatly increase the concentration of MSCs. It is a rapid and safe method used peri-operatively. The composite material of enriched MSCs and porous beta-TCP is a good bone substitute in posterior spinal fusion.

Effects of Two Surfactants and Beta-Cyclodextrin on Beta-Cypermethrin Degradation by Bacillus licheniformis B-1.

The biodegradation efficiency of beta-cypermethrin (ß-CY) is low especially at high concentrations mainly due to poor contact between this hydrophobic pesticide and microbial cells. In this study, the effects of two biodegradable surfactants (Tween-80 and Brij-35) and ß-cyclodextrin (ß-CD) on the growth and cell surface hydrophobicity (CSH) of Bacillus licheniformis B-1 were studied. Furthermore, their effects on the solubility, biosorption, and degradation of ß-CY were investigated. The results showed that Tween-80 could slightly promote the growth of the strain while Brij-35 and ß-CD exhibited little effect on its growth. The CSH of strain B-1 and the solubility of ß-CY were obviously changed by using Tween-80 and Brij-35. The surfactants and ß-CD could enhance ß-CY biosorption and degradation by the strain, and the highest degradation was obtained in the presence of Brij-35. When the surfactant or ß-CD concentration was 2.4 g/L, the degradation rate of ß-CY in Brij-35, Tween-80, and ß-CD treatments was 89.4%, 50.5%, and 48.1%, respectively. The half-life of ß-CY by using Brij-35 was shortened by 69.1 h. Beta-CY content in the soil with both strain B-1 and Brij-35 decreased from 22.29 mg/kg to 4.41 mg/kg after incubation for 22 d. This work can provide a promising approach for the efficient degradation of pyrethroid pesticides by microorganisms.

Graphene Oxide Selectively Enhances Thermostability of Trypsin.

In the past few years, graphene and its derivative, graphene oxide (GO), have been extensively studied for their applications in biotechnology. In our previous work, we reported certain PEGylated GOs (GO-PEGs) can selectively promote trypsin activity and enhance its thermostability. To further explore this, here we synthesized a series of GO-PEGs with varying PEGylation degrees. Enzymatic activity assay shows that both GO and GO-PEGs can protect trypsin, but not chymotrypsin, from thermal denaturation at high temperature. Surprisingly, the lower the PEGylation degree, the better the protection, and GO as well as the GO-PEG with the lowest PEGylation degree show the highest protection efficiency (∼70% retained activity at 70 °C). Fluorescence spectroscopy analysis shows that GO/GO-PEGs have strong interactions with trypsin. Molecular Dynamics (MD) simulation results reveal that trypsin is adsorbed onto the surface of GO through its cationic residues and hydrophilic residues. Different from chymotrypsin adsorbed on GO, the active site of trypsin is covered by GO. MD simulation at high temperature shows that, through such interaction with GO, trypsin's active site is therefore stabilized and protected by GO. Our work not only illustrates the promising potential of GO/GO-PEGs as efficient, selective modulators for trypsin, but also provides the interaction mechanism of GO with specific proteins at the nano-bio interface.

Biomimetic material--poly(N-vinylimidazole)-zinc complex for CO2 separation.

A novel material, poly(N-vinylimidazole)-zinc complex, is prepared to simulate the zinc active site of carbonic anhydrase. The obtained complex can separate CO(2) efficiently.