Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
1.
Adv Mater ; : e2406623, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38899799

ABSTRACT

Morphology control is crucial in achieving high-performance organic solar cells (OSCs) and remains a major challenge in the field of OSC. Solid additive is an effective strategy to fine-tune morphology, however, the mechanism underlying isomeric solid additives on blend morphology and OSC performance is still vague and urgently requires further investigation. Herein, two solid additives based on pyridazine or pyrimidine as core units, M1 and M2, are designed and synthesized to explore working mechanism of the isomeric solid additives in OSCs. The smaller steric hindrance and larger dipole moment facilitate better π-π stacking and aggregation in M1-based active layer. The M1-treated all-small-molecule OSCs (ASM OSCs) obtain an impressive efficiency of 17.57%, ranking among the highest values for binary ASM OSCs, with 16.70% for M2-treated counterparts. Moreover, it is imperative to investigate whether the isomerization engineering of solid additives works in state-of-the-art polymer OSCs. M1-treated D18-Cl:PM6:L8-BO-based devices achieve an exceptional efficiency of 19.70% (certified as 19.34%), among the highest values for OSCs. The work provides deep insights into the design of solid additives and clarifies the potential working mechanism for optimizing the morphology and device performance through isomerization engineering of solid additives.

2.
Adv Mater ; 36(16): e2312635, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38229541

ABSTRACT

Efficient cathode interfacial materials (CIMs) are essential components for effectively enhancing the performance of organic solar cells (OSCs). Although high-performance CIMs are desired to meet the requirements of various OSCs, potential candidates for CIMs are scarce. Herein, an amino-functionalized graphdiyne derivative (GDY-N) is developed, which represents the first example of GDY that exhibits favorable solubility in alcohol. Utilizing GDY-N as the CIM, an outstanding champion PCE of 19.30% for devices based on the D18-Cl:L8-BO (certified result: 19.05%) is achieved, which is among the highest efficiencies reported to date in OSCs. Remarkably, the devices based on GDY-N exhibit a thickness-insensitive characteristic, maintaining 95% of their initial efficiency even with a film thickness of 25 nm. Moreover, the GDY-N displays wide universality and facilitates exceptional stability in OSCs. This work not only enriches the diversity of GDY derivatives, but also demonstrates the feasibility of GDY derivatives as CIMs with high thickness tolerance in OSCs.

3.
J Chromatogr A ; 1713: 464528, 2024 Jan 04.
Article in English | MEDLINE | ID: mdl-38029658

ABSTRACT

Multi-column periodic counter-current chromatography is a promising technology for continuous antibody capture. However, dynamic changes due to disturbances and drifts pose some potential risks for continuous processes during long-term operation. In this study, a model-based approach was used to describe the changes in breakthrough curves with feedstock variations in target proteins and impurities. The performances of continuous capture of three-column periodic counter-current chromatography under ΔUV dynamic control were systematically evaluated with modeling to assess the risks under different feedstock variations. As the concentration of target protein decreased rapidly, the protein might not breakthrough from the first column, resulting in the failure of ΔUV control. Small reductions in the concentrations of target proteins or impurities would cause protein losses, which could be predicted by the modeling. The combination of target protein and impurity variations showed complicated effects on the process performance of continuous capture. A contour map was proposed to describe the comprehensive impacts under different situations, and nonoperation areas could be identified due to control failure or protein loss. With the model-based approach, after the model parameters are estimated from the breakthrough curves, it can rapidly predict the process stability under dynamic control and assess the risks under feedstock variations or UV signal drifts. In conclusion, the model-based approach is a powerful tool for continuous process evaluation under dynamic changes and would be useful for establishing a new real-time dynamic control strategy.


Subject(s)
Antibodies, Monoclonal , Countercurrent Distribution , Countercurrent Distribution/methods , Antibodies, Monoclonal/chemistry , Staphylococcal Protein A/chemistry
4.
J Chromatogr A ; 1707: 464302, 2023 Sep 27.
Article in English | MEDLINE | ID: mdl-37607430

ABSTRACT

Continuous manufacturing in monoclonal antibody production has generated increased interest due to its consistent quality, high productivity, high equipment utilization, and low cost. One of the major challenges in realizing continuous biological manufacturing lies in implementing continuous chromatography. Given the complex operation mode and various operation parameters, it is challenging to develop a continuous process. Due to the process parameters being mainly determined by the breakthrough curves and elution behaviors, chromatographic modeling has gradually been used to assist in process development and characterization. Model-assisted approaches could realize multi-parameter interaction investigation and multi-objective optimization by integrating continuous process models. These approaches could reduce time and resource consumption while achieving a comprehensive and systematic understanding of the process. This paper reviews the application of modeling tools in continuous chromatography process development, characterization and design. Model-assisted process development approaches for continuous capture and polishing steps are introduced and summarized. The challenges and potential of model-assisted process characterization are discussed, emphasizing the need for further research on the design space determination strategy and parameter robustness analysis method. Additionally, some model applications for process design were highlighted to promote the establishment of the process optimization and process simulation platform.


Subject(s)
Antibodies , Chromatography , Commerce , Computer Simulation
5.
Angew Chem Int Ed Engl ; 62(11): e202217173, 2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36692893

ABSTRACT

The design and selection of a suitable guest acceptor are particularly important for improving the photovoltaic performance of ternary organic solar cells (OSCs). Herein, we designed and successfully synthesized two asymmetric silicon-oxygen bridged guest acceptors, which featured distinct blue-shifted absorption, upshifted lowest unoccupied molecular orbital energy levels, and larger dipole moments than symmetric silicon-oxygen-bridged acceptor. Ternary devices with the incorporation of 14.2 wt % these two asymmetric guest acceptors exhibited excellent performance with power conversion efficiencies (PCEs) of 18.22 % and 18.77 %, respectively. Our success in precise control of material properties via structural fusion of five-membered carbon linkages and six-membered silicon-oxygen connection at the central electron-donating core unit of fused-ring electron acceptors can attract considerable attention and bring new vigor and vitality for developing new materials toward more efficient OSCs.

6.
Small ; 19(3): e2205594, 2023 01.
Article in English | MEDLINE | ID: mdl-36449633

ABSTRACT

Active layer material plays a critical role in promoting the performance of an organic solar cell (OSC). Small-molecule (SM) materials have the merits of well-defined chemical structures, few batch-to-batch variations, facile synthesis and purification procedures, and easily tuned properties. SM-donor and non-fullerene acceptor (NFA) innovations have recently produced all-small-molecule (ASM) devices with power conversion efficiencies that exceed 17% and approach those of their polymer-based counterparts, thereby demonstrating their great future commercialization potential. In this review, recent progress in both SM donors and NFAs to illustrate structure-property relationships and various morphology-regulation strategies are summarized. Finally, ASM-OSC challenges and outlook are discussed.


Subject(s)
Polymers
7.
J Chromatogr A ; 1677: 463311, 2022 Aug 16.
Article in English | MEDLINE | ID: mdl-35843202

ABSTRACT

Multi-column counter-current chromatography is an advanced technology used for continuous capture processes to improve process productivity, resin capacity utilization and product consistency. However, process development is difficult due to process complexity. In this work, some general and convenient guidances for three-column periodic counter-current chromatography (3C-PCC) were developed. Boundaries and distributions of operating windows of 3C-PCC processes were clarified by model-based predictions. Interactive effects of feed concentration (c0), resin properties (qmax and De), recovery and regeneration times (tRR) were evaluated over a wide range for maximum productivity (Pmax). Furthermore, variation of Pmax was analyzed considering the constraint factors (capacity utilization target and flow rate limitation). The plateau value of Pmax was determined by qmax and tRR. The operating conditions for Pmax were controlled by qmax, tRR and c0 interactively, and a critical concentration existed to judge whether the operating conditions of Pmax under constraints. Based on the comprehensive understanding on 3C-PCC processes, a model-free strategy was proposed for process development. The optimal operating conditions could be determined based on a set of breakthrough curves, which was used to optimize process performance and screen resins. The approach proposed was validated using monoclonal antibody (mAb) capture with a 3C-PCC system under various mAb and feed concentrations. The results demonstrated that a thorough model-based process understanding on multi-column counter-current chromatography is important and could improve process development and establish a model-free strategy for more convenient applications.


Subject(s)
Countercurrent Distribution , Staphylococcal Protein A , Antibodies, Monoclonal/chemistry , Countercurrent Distribution/methods , Resins, Plant , Staphylococcal Protein A/chemistry
8.
Med Sci Monit ; 28: e936248, 2022 Jun 25.
Article in English | MEDLINE | ID: mdl-35751366

ABSTRACT

BACKGROUND High levels of TP53 protein can lead to apoptosis of myocardial cells. However, TP53 protein influence of myocardial damage remains unclear. This prospective study investigated the involvement of TP53 protein in secondary myocardial damage in children up to 18 years of age. MATERIAL AND METHODS Serum TP53 protein, N-terminal prohormone B-type natriuretic peptide (NT-ProBNP), cardiac troponin-I (cTnI), and creatine kinase isoenzyme MB (CK-MB) concentrations were measured in 50 hospitalized patients with secondary myocardial damage, 50 hospitalized patients without myocardial damage, and 50 healthy individuals (control). Cardiac damage was diagnosed based on cTnI, NT-ProBNP, and CK-MB levels, with electrocardiographic evidence as the reference. The appropriate cut-off value of TP53 protein for secondary myocardial damage was analyzed by receiver operating characteristic (ROC) curves. RESULTS The serum TP53 protein, NT-ProBNP, cTnI, and CK-MB concentrations of the patients with and without myocardial damage were 10.20±1.20 and 0.30±0.10 ng/L, 505.30 and 107.8 ng/L, 0.23±0.13 and 0.02±0.01 µg/L, and 28.30±5.13 and 12.24±4.29 IU/L, respectively. For the 50 patients with myocardial damage, the area under the ROC curve for serum TP53 protein, NT-ProBNP, cTnI, and CK-MB concentrations were 0.89 (95% CI: 0.81-0.95), 0.83 (95% CI: 0.77-0.91), 0.92 (95% CI: 0.84-0.97), and 0.85 (95% CI: 0.78-0.93), respectively, and the diagnostic cut-off values were 12.00 ng/L, 500.00 ng/L, 0.16 µg/L, and 27.00 IU/L, respectively, with positive likelihood ratios of 20.8, 13.2, 24.6, and 15.6. CONCLUSIONS TP53 protein is a valid biomarker of secondary myocardial damage in pediatric patients and can be diagnostic.


Subject(s)
Natriuretic Peptide, Brain , Tumor Suppressor Protein p53 , Biomarkers , Blood Proteins , Child , Creatine Kinase, MB Form , Humans , Peptide Fragments , Prospective Studies , ROC Curve , Troponin I
9.
Macromol Rapid Commun ; 43(22): e2200139, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35319114

ABSTRACT

All-polymer solar cells (all-PSCs) are one of the most promising application-oriented organic photovoltaic technologies due to their excellent operational and mechanical stability. However, the power conversion efficiencies (PCEs) are mostly lower than 16%, restricting their core competitiveness. Furthermore, the improvement of mechanical durability is rarely paid attention to cutting-edge all-PSCs. This work deploys a low-cost "technical grade" PCBM (incompletely separated but pure mixtures containing ≥90% [70]PCBM or [60]PCBM), into the efficient PM6:PY-IT all-polymer blend, successfully yielding a high-performance ternary device with 16.16% PCE, among the highest PCE values for all-PSCs. Meanwhile, an excellent mechanical property (i.e., crack onset strain = 11.1%) promoted from 9.5% for the ternary system is also demonstrated. The "technical grade" PCBM slightly disrupts the crystallization of polymers, and disperses well into the amorphous polymer regions of the all-PSC blends, thus facilitating charge transport and improving film ductility simultaneously. All these results confirm introducing low-cost "technical grade" PCBM with high electron mobility into all-polymer blends can improve carrier mobility, reduce charge recombination, and optimize morphology of the amorphous polymer regions, thus yielding more efficient and mechanically durable all-PSCs.

10.
Med Sci Monit ; 27: e933400, 2021 Dec 18.
Article in English | MEDLINE | ID: mdl-34921128

ABSTRACT

BACKGROUND The N-terminal fragment of proB-type natriuretic peptide (NT-proBNP) is an established predictive marker for sepsis-related mortality in adult. This retrospective study aimed to determine age-stratified cut-off values for serum levels of NT-proBNP and mortality from sepsis in children under 18 years. MATERIAL AND METHODS Patients were stratified by age as follows: <1 year, 1-3 years, 4-6 years, and 7-18 years (age groups). The control group consisted of age- and sex-matched healthy children. Serum NT-proBNP levels were detected by laboratory assays in the participants. The appropriate serum NT-proBNP cut-off values for predicting short-term mortality of the sepsis patients were calculated via receiver operating characteristic (ROC) curve analyses. RESULTS Among 327 pediatric patients with sepsis, the serum NT-proBNP cut-off concentrations for predicting sepsis-related mortality in the <1 year, 1-3 years, 4-6 years, and 7-18 years age groups were 5000 ng/L, 4500 ng/L, 4100 ng/L, and 3800 ng/L, respectively (P<0.001). The area under the ROC curve (AUC) values for these were 0.815, 0.812, 0.806 and 0.725, respectively (P<0.001). CONCLUSIONS This retrospective study provided the age range-specific serum NT-proBNP cut- off concentrations for predicting short-term mortality in children. In children <1 year, 1-3 years, 4-6 years, and 7-18 years, age-stratified cut-off values that predicted sepsis-associated mortality were 5000 ng/L, 4500 ng/L, 4100 ng/L, and 3800 ng/L, respectively.


Subject(s)
Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Sepsis/mortality , Adolescent , Age Factors , Biomarkers/blood , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , ROC Curve , Retrospective Studies , Sepsis/blood
11.
J Chromatogr A ; 1654: 462454, 2021 Sep 27.
Article in English | MEDLINE | ID: mdl-34407469

ABSTRACT

Continuous chromatography is a promising technology for downstream processing of biopharmaceuticals. The operation of continuous processes is significantly different to batch-mode chromatography and needs comprehensive evaluation. In this work, the performances of four Protein A affinity resins were studied systematically for twin-column continuous capture processes. A model-based approach was used to evaluate the process performance (productivity and capacity utilization) under varying operation conditions, and the objective was to reveal the crucial resin properties for continuous capture. The trade-off between productivity and capacity utilization was found, and it is necessary to select appropriate resins for different feedstock and operation conditions. The capacity utilization heavily depends on mass transfer, and steep breakthrough curves are favorable for high capacity utilization. The productivity is determined by both equilibrium binding capacity and mass transfer, and the balance of feed amount and feed time is critical. Moreover, the influence of binding capacity and mass transfer on process productivity and parameter sensitivity with two important resin properties (equilibrium binding capacity qmax and effective pore diffusion coefficient De) were assessed by the model, and suitable resin parameter ranges for twin-column continuous capture were determined. The model-based approach is an effective and useful tool to evaluate the complex performance of different resins and guide the design of next-generation resins for continuous processes.


Subject(s)
Chromatography, Affinity , Staphylococcal Protein A , Chromatography, Affinity/instrumentation , Chromatography, Affinity/standards , Models, Chemical , Staphylococcal Protein A/metabolism
12.
ACS Appl Mater Interfaces ; 13(34): 40766-40777, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34424658

ABSTRACT

A ternary strategy is recognized as a promising approach that enjoys both the simplicity of fabrication conditions and potential to improve performance in organic solar cells. Herein, a C-shaped narrow band gap non-fullerene acceptor GL1 with a C2v symmetry based on a new core was designed and synthesized. A power conversion efficiency (PCE) of 11.43% was achieved by employing PBDB-T:GL1 as an active layer to fabricate photovoltaic devices. To further promote photovoltaic performance, following a similar-structure prescreen principle, a middle band gap acceptor F-2Cl with the same backbone shape, side-chain distribution, and dipole moment orientation as GL1 was introduced as the guest acceptor into the active layer. Thus, benefiting from the collaboration of complementary absorption, cascade energy levels, and well-modified microstructure of the active layer, a 13.17% PCE was obtained with concurrently elevated Jsc, fill factor, and stability for the optimized ternary device. This work presents a successful example of prescreening the third component to simplify the workload for a high-performance ternary device.

13.
RSC Adv ; 11(28): 17332-17339, 2021 May 06.
Article in English | MEDLINE | ID: mdl-35479682

ABSTRACT

Numerous efforts have been devoted to capability improvement and cycling stability in the past decades, and these performances have been significantly enhanced. Low initial coulombic efficiency is still a problem in the metal sulfide-based anode materials. This study developed a strategy to achieve high initial coulombic efficiency and superior capacity retention by interpenetrating binary metal sulfides of SnS and MoS2 in a conductive carbon matrix. The synergy ascension of electrochemical performances for the metal sulfides is attributed to their mutual impeding effects on coarsening of metal grains and the capsule-shaped coating structure embedded in the carbon sheet architecture. The SnS/MoS2/C composite was prepared by a simple NaCl template-assisted ball milling method, and showed excellent electrochemical performances in terms of a high initial coulombic efficiency up to 90.2% and highly stable reversibility with a specific capacity of 515.4 mA h g-1 after 300 cycles at 1.0 A g-1. All of these characteristics suggest that the proposed materials are superior among the previously reported metal sulfide-based anode materials for lithium-ion batteries.

14.
J Chromatogr A ; 1625: 461300, 2020 Aug 16.
Article in English | MEDLINE | ID: mdl-32709343

ABSTRACT

Multi-column continuous chromatography has advantages of high resin capacity utilization and productivity, low buffer consumption and small footprint. Experimental optimization is often time-consuming and inefficient due to the complexity of continuous processes. In this study, a model-based approach was investigated to improve process development of twin-column continuous capture with Protein A affinity resin MabSelect PrismA. Breakthrough curves under various conditions, productivity and capacity utilization (CU) of the continuous processes under varying operating conditions were predicted. Effects of three key operating parameters (feed concentration (c0), interconnected feed residence time (RT) and breakthrough percentage control of the first column during interconnected feeding (s)) on the productivity and CU were evaluated. A recommended working window can be determined directly from contour maps to balance the trade-off between productivity and CU. The model-optimized operating conditions at varying feed concentrations were verified by experiments, which indicated that the model-based approach was feasible and reliable. The results showed that the suitable RT was 1~2 min and suitable s was 0.6~0.75 for the continuous IgG capture with MabSelect PrismA. The maximum productivity varied from 14 to 47 g/L/h with the feed IgG concentrations at the range of 1 to 10 mg/mL. The results indicated that model-based approach could assist process development efficiently and promote target-orientated process design for continuous processes.


Subject(s)
Chromatography, Affinity/methods , Models, Theoretical , Resins, Synthetic/chemistry , Staphylococcal Protein A/chemistry , Humans , Reproducibility of Results , Time Factors
15.
Front Chem ; 8: 329, 2020.
Article in English | MEDLINE | ID: mdl-32411669

ABSTRACT

A new small molecule donor with an acceptor-donor-acceptor (A-D-A) structure, namely DRTB-FT, has been designed and synthesized for all-small-molecule organic solar cells (ASM-OSCs). By introducing fluorine atoms on the thienyl substituent of the central benzodithiophene unit, DRTB-FT shows a low-lying highest occupied molecular orbital (HOMO) energy level of -5.64 eV. Blending with an A-D-A type acceptor F-2Cl, DRTB-FT based ASM-OSCs gave a power conversion efficiency (PCE) of 7.66% with a high open-circuit voltage (V oc) of 1.070 V and a low energy loss of 0.47 eV. The results indicate that high V oc of ASM-OSC devices can be obtained through careful donor molecular optimization.

16.
ACS Appl Mater Interfaces ; 12(24): 27425-27432, 2020 Jun 17.
Article in English | MEDLINE | ID: mdl-32466636

ABSTRACT

Adding an additive is one of the effective strategies to fine-tune active layer morphology and improve performance of organic solar cells. In this work, a binary additive 1,8-diiodooctane (DIO) and 2,6-dimethoxynaphthalene (DMON) to optimize the morphology of PBDB-T:TTC8-O1-4F-based devices is reported. With the binary additive, a power conversion efficiency (PCE) of 13.22% was achieved, which is higher than those of devices using DIO (12.05%) or DMON (11.19%) individually. Comparison studies demonstrate that DIO can induce the acceptor TTC8-O1-4F to form ordered packing, while DMON can inhibit excessive aggregation of the donor and acceptor. With the synergistic effect of these two additives, the PBDB-T:TTC8-O1-4F blend film with DIO and DMON exhibits a suitable phase separation and crystallite size, leading to a high short-circuit current density (Jsc) of 23.04 mA·cm-2 and a fill factor of 0.703 and thus improved PCE.

17.
J Biol Chem ; 294(17): 6670-6684, 2019 04 26.
Article in English | MEDLINE | ID: mdl-30803987

ABSTRACT

Blood platelets are required for normal wound healing, but they are also involved in thrombotic diseases, which are usually managed with anticoagulant drugs. Here, using genetic engineering, we coupled the disintegrin protein echistatin, which specifically binds to the platelet integrin αIIbß3 receptor, to annexin V, which binds platelet membrane-associated phosphatidylserine (PS), to create the bifunctional antithrombotic molecule recombinant echistatin-annexin V fusion protein (r-EchAV). Lipid binding and plasma coagulation studies revealed that r-EchAV dose-dependently binds PS and delays plasma clotting time. Moreover, r-EchAV inhibited ADP-induced platelet aggregation in a dose-dependent manner and exhibited potent antiplatelet aggregation effects. r-EchAV significantly prolonged activated partial thromboplastin time, suggesting that it primarily affects the in vivo coagulation pathway. Flow cytometry results indicated that r-EchAV could effectively bind to the platelet αIIbß3 receptor, indicating that r-EchAV retains echistatin's receptor-recognition region. In vivo experiments in mice disclosed that r-EchAV significantly prolongs bleeding time, indicating a significant anticoagulant effect in vivo resulting from the joint binding of r-EchAV to both PS and the αIIbß3 receptor. We also report optimization of the r-EchAV production steps and its purification for high purity and yield. Our findings indicate that r-EchAV retains the active structural regions of echistatin and annexin V and that the whole molecule exhibits multitarget-binding ability arising from the dual functions of echistatin and annexin V. Therefore, r-EchAV represents a new class of anticoagulant that specifically targets the anionic membrane-associated coagulation enzyme complexes at thrombogenesis sites and may be a potentially useful antithrombotic agent.


Subject(s)
Annexin A5/metabolism , Blood Coagulation/drug effects , Intercellular Signaling Peptides and Proteins/metabolism , Phosphatidylserines/metabolism , Platelet Glycoprotein GPIIb-IIIa Complex/metabolism , Recombinant Fusion Proteins/metabolism , Thrombosis/prevention & control , Animals , Escherichia coli/genetics , Humans , Male , Mice , Phosphatidylserines/pharmacology , Platelet Aggregation/drug effects , Protein Binding , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/pharmacology
18.
Adv Sci (Weinh) ; 5(6): 1800307, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29938192

ABSTRACT

A new acceptor-donor-acceptor (A-D-A) type nonfullerene acceptor, 3TT-FIC, which has three fused thieno[3,2-b]thiophene as the central core and difluoro substituted indanone as the end groups, is designed and synthesized. 3TT-FIC exhibits broad and strong absorption with extended onset absorption to 995 nm and a low optical bandgap of 1.25 eV. The binary device based on 3TT-FIC and the polymer PTB7-Th exhibits a power conversion efficiency (PCE) of 12.21% with a high short circuit current density (   Jsc) of 25.89 mA cm-2. To fine-tune the morphology and make full use of the visible region sunlight, phenyl-C71-butyricacid-methyl ester (PC71BM) is used as the third component to fabricate ternary devices. In contrast to the binary devices, the ternary blend organic solar cells show significantly enhanced EQE ranging from 300 to 700 nm and thus an improved  Jsc with a high value of 27.73 mA cm-2. A high PCE with a value of 13.54% is achieved for the ternary devices, which is one of the highest efficiencies in single junction organic solar cells reported to date. The results provide valuable insight for the ternary devices in which the external quantum efficiency (EQE) induced by the third component is evidently observed and directly contributed to the enhancement of the device efficiency.

19.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi ; 32(6): 736-744, 2018 06 15.
Article in Chinese | MEDLINE | ID: mdl-29905054

ABSTRACT

Objective: To investigate the early effects of acellular xenogeneic nerve combined with adipose-derived stem cells (ADSCs) and platelet rich plasma (PRP) in repairing facial nerve injury in rabbits. Methods: The bilateral sciatic nerves of 15 3-month-old male Sprague-Dawley rats were harvested and decellularized as xenografts. The allogeneic ADSCs were extracted from the neck and back fat pad of healthy adult New Zealand rabbits with a method of digestion by collagenase type Ⅰ and the autologous PRP was prepared by two step centrifugation. The 3rd generation ADSCs with good growth were labelled with CM-Dil living cell stain, and the labelling and fluorescence attenuation of the cells were observed by fluorescence microscope. Another 32 New Zealand rabbits were randomly divided into 4 groups and established the left facial nerve defect in length of 1 cm ( n=8). The nerve defects of groups A, B, C, and D were repaired with CM-Dil-ADSCs composite xenogeneic nerve+autologous PRP, CM-Dil-ADSCs composite xenogeneic nerve, xenogeneic nerve, and autologous nerve, respectively. At 1 and 8 weeks after operation, the angle between the upper lip and the median line of the face (angle θ) was measured. At 4 and 8 weeks after operation, the nerve conduction velocity was recorded by electrophysiological examination. At 8 weeks after operation, the CM-Dil-ADSCs at the distal and proximal ends of regenerative nerve graft segment in groups A and B were observed by fluorescence microscopy; after toluidine blue staining, the number of myelinated nerve fibers in regenerated nerve was calculated; the structure of regenerated nerve fibers was observed by transmission electron microscope. Results: ADSCs labelled by CM-Dil showed that the labelling rate of cells was more than 90% under fluorescence microscope, and the labelled cells proliferated well, and the fluorescence attenuated slightly after passage. All the animals survived after operation, the incision healed well and no infection occurred. At 1 week after operation, all the animals in each group had different degrees of dysfunction. The angle θ of the left side in groups A, B, C, and D were (53.4±2.5), (54.0±2.6), (53.7±2.4), and (53.0±2.1)°, respectively; showing significant differences when compared with the healthy sides ( P<0.05). At 8 weeks after operation, the angle θ of the left side in groups A, B, C, and D were (61.9±4.7), (56.8±4.2), (54.6±3.8), and (63.8±5.8)°, respectively; showing significant differences when compared with the healthy sides and with the values at 1 week ( P<0.05). Gross observation showed that the integrity and continuity of regenerated nerve in 4 groups were good, and no neuroma and obvious enlargement was found. At 4 and 8 weeks after operation, the electrophysiological examination results showed that the nerve conduction velocity was significantly faster in groups A and D than in groups B and C ( P<0.05), and in group B than in group C ( P<0.05); no significant difference was found between groups A and D ( P>0.05). At 8 weeks after operation, the fluorescence microscopy observation showed a large number of CM-Dil-ADSCs passing through the distal and proximal transplants in group A, and relatively few cells passing in group B. Toluidine blue staining showed that the density of myelinated nerve fibers in groups A and D were significantly higher than those in groups B and C ( P<0.05), and in group B than in group C ( P<0.05); no significant difference was found between groups A and D ( P>0.05). Transmission electron microscope observation showed that the myelinated nerve sheath in group D was large in diameter and thickness in wall. The morphology of myelin sheath in group A was irregular and smaller than that in group D, and there was no significant difference between groups B and C. Conclusion: ADSCs can survive as a seed cell in vivo, and can be differentiated into Schwann-like cells under PRP induction. It can achieve better results when combined with acellular xenogeneic nerve to repair peripheral nerve injury in rabbits.


Subject(s)
Facial Nerve Injuries , Nerve Regeneration , Platelet-Rich Plasma , Stem Cell Transplantation , Adipocytes , Animals , Facial Nerve Injuries/therapy , Male , Rabbits , Rats , Rats, Sprague-Dawley , Sciatic Nerve , Stem Cells
20.
Adv Mater ; 30(18): e1707508, 2018 May.
Article in English | MEDLINE | ID: mdl-29575107

ABSTRACT

Fabricating solar cells with tandem structure is an efficient way to broaden the photon response range without further increasing the thermalization loss in the system. In this work, a tandem organic solar cell (TOSC) based on highly efficient nonfullerene acceptors (NFAs) with series connection type is demonstrated. To meet the different demands of front and rear sub-cells, two NFAs named F-M and NOBDT with a whole absorption range from 300 to 900 nm are designed, when blended with wide bandgap polymer poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))] (PBDB-T) and narrow bandgap polymer PTB7-Th, respectively, the PBDB-T: F-M system exhibits a high Voc of 0.98 V and the PTB7-Th: NOBDT system shows a remarkable Jsc of 19.16 mA cm-2 , which demonstrate their potential in the TOSCs. With the guidance of optical simulation, by systematically optimizing the thickness of each layer in the TOSC, an outstanding power conversion efficiency of 14.11%, with a Voc of 1.71 V, a Jsc of 11.72 mA cm-2 , and a satisfactory fill factor of 0.70 is achieved; this result is one of the top efficiencies reported to date in the field of organic solar cells.

SELECTION OF CITATIONS
SEARCH DETAIL
...