Optimized Crystal Framework by Asymmetric Core Isomerization in Selenium-Substituted Acceptor for Efficient Binary Organic Solar Cells.

Both the regional isomerization and selenium-substitution of the small molecular acceptors (SMAs) play significant roles in developing efficient organic solar cells (OSCs), while their synergistic effects remain elusive. Herein, we developed three isomeric SMAs (S-CSeF, A-ISeF, and A-OSeF) via subtly manipulating the mono-selenium substituted position (central, inner, or outer) and type of heteroaromatic ring on the central core by synergistic strategies for efficient OSCs, respectively. Crystallography of asymmetric A-OSeF presents a closer intermolecular π-π stacking and more ordered 3-dimensional network packing and efficient charge-hopping pathways. With the successive out-shift of the mono-selenium substituted position, the neat films give a slightly wider band gap and gradually higher crystallinity and electron mobility. The PM1 : A-OSeF afford favourable fibrous phase separation morphology with more ordered molecular packing and efficient charge transportation compared to the other two counterparts. Consequently, the A-OSeF-based devices achieve a champion efficiency of 18.5 %, which represents the record value for the reported selenium-containing SMAs in binary OSCs. Our developed precise molecular engineering of the position and type of selenium-based heteroaromatic ring of SMAs provides a promising synergistic approach to optimizing crystal stacking and boosting top-ranked selenium-containing SMAs-based OSCs.

Regioisomer-Free Difluoro-Monochloro Terminal-based Hexa-Halogenated Acceptor with Optimized Crystal Packing for Efficient Binary Organic Solar Cells.

Herein, we synthesized new hetero-halogenated end groups with well-determined fluorinated and chlorinated substitutions (o-FCl-IC and FClF-IC), and synthesized regioisomer-free small molecular acceptors (SMAs) Y-Cl, Y-FCl, and Y-FClF with distinct hetero-halogenated terminals, respectively. The single-crystal structures and theoretical calculations indicate that Y-FClF exhibits more compact three-dimensional network packing and more significant π-π electronic coupling compared to Y-FCl. From Y-Cl to Y-FCl to Y-FClF, the neat films exhibit a narrower optical band gap and gradually enhanced electron mobility and crystallinity. The PM6 : Y-FClF blend film exhibits the strongest crystallinity with preferential face-on molecular packing, desirable fibrous morphology with suitable phase segregation, and the highest and balanced charge mobilities among three blend films. Overall, the PM6 : Y-FClF organic solar cells (OSCs) deliver a remarkable efficiency of 17.65 %, outperforming the PM6 : Y-FCl and PM6 : Y-Cl, which is the best PCE for reported hetero-halogens-based SMAs in binary OSCs. Our results demonstrate that difluoro-monochloro hetero-terminal is a superior regio-regular unit for enhancing the intermolecular crystal packing and photovoltaic performance of hetero-halogenated SMAs.

Two-Dimensional Conjugated Benzo[1,2-b:4,5-b']diselenophene-Based Copolymer Donor Enables Large Open-Circuit Voltage and High Efficiency in Selenophene-based Organic Solar Cells.

A two-dimensional electron-rich fused-ring moiety (ClBDSe) based on benzo[1,2-b:4,5-b']diselenophene is synthesized. Three copolymers (PBDT-Se, PBDSe-T, and PBDSe-Se) are obtained by manipulating the connection types and number of selenophene units on the conjugated main chains with two 2D fused-ring units and two different π-bridges, respectively. In comparison with PBDT-Se and PBDSe-Se, PBDSe-T with benzo[1,2-b:4,5-b']diselenophene unit and thiophene π-bridge exhibits the deepest HOMO energy level and the strongest crystallinity in neat films. The PBDSe-T:Y6 blend film exhibits the best absorption complementarity, the most distinctive face-on orientation with proper phase separation, the highest carrier mobilities, and the lowest charge recombination among three blend films. Finally, the PBDSe-T:Y6-based device delivers an impressive power conversion efficiency (PCE) of 14.50 %, which is higher than those of PBDT-Se:Y6 and PBDSe-Se:Y6. Moreover, a decent open-circuit voltage (Voc ) of 0.89 V with a remarkably small energy loss of 0.44 eV is achieved for PBDSe-T:Y6. The efficiency of 14.50 % is the highest value for selenophene-containing copolymer-based binary organic solar cells (OSCs). This study provides evidence that introduction of 2D-benzo[1,2-b:4,5-b']diselenophene as a fused electron-rich unit with π-bridging into copolymeric donors is a valid strategy for providing high Voc and excellent PCE simultaneously in selenophene-based OSCs.

A Synergistic Strategy of Manipulating the Number of Selenophene Units and Dissymmetric Central Core of Small Molecular Acceptors Enables Polymer Solar Cells with 17.5 % Efficiency.

A dissymmetric backbone and selenophene substitution on the central core was used for the synthesis of symmetric or dissymmetric A-DA'D-A type non-fullerene small molecular acceptors (NF-SMAs) with different numbers of selenophene. From S-YSS-Cl to A-WSSe-Cl and to S-WSeSe-Cl, a gradually red-shifted absorption and a gradually larger electron mobility and crystallinity in neat thin film was observed. A-WSSe-Cl and S-WSeSe-Cl exhibit stronger and tighter intermolecular π-π stacking interactions, extra S⋅⋅⋅N non-covalent intermolecular interactions from central benzothiadiazole, better ordered 3D interpenetrating charge-transfer networks in comparison with thiophene-based S-YSS-Cl. The dissymmetric A-WSSe-Cl-based device has a PCE of 17.51 %, which is the highest value for selenophene-based NF-SMAs in binary polymer solar cells. The combination of dissymmetric core and precise replacement of selenophene on the central core is effective to improve Jsc and FF without sacrificing Voc .

Uncoupling protein 2 combats oxidative damage to human sperm / 中华男科学杂志

<p><b>OBJECTIVE</b>Germ cells are much more susceptible to oxidative stress than somatic cells. Accumulating evidence indicates that uncoupling protein 2 (UCP2) prevents the apoptosis of multiple types of cells induced by reactive oxygen species (ROS). The present study aimed to evaluate the protective effect of uncoupling protein 2 (UCP2) against oxidative damage to human sperm.</p><p><b>METHODS</b>Semen parameters were obtained from 97 semen samples by computer assisted sperm analysis (CASA), and the samples, based on the percentage of grade a + b sperm, allotted to Groups I (n = 25, grade a + b sperm > 50%), II (n = 24, grade a + b sperm 25%-50%), III (n = 24, grade a + b sperm 10-25%) and IV (n = 24, grade a + b sperm < 10%). The expressions of sperm UCP2 mRNA was detected by RT-PCR, and the malonaldehyde (MDA) content in ROS was determined in the sperm suspension.</p><p><b>RESULTS</b>The expressions of UCP2 mRNA in sperm were 1.51 +/- 0.24, 1.28 +/- 0.15, 1.17 +/- 0.20 and 0.69 +/- 0.18, and the MDA contents were (14.66 +/- 2.55), (16.00 +/- 2.09), (17.44 +/- 1.40) and (21.20 +/- 3.50) nmol/10(8) sperm in Groups I, II, III and lV, respectively. There was a significant negative correlation between the expression of UCP2 mRNA and the content of MDA (r = -0.633, P < 0.01), the former obviously reduced while the latter remarkably increased in the groups of lower sperm motility (P < 0.01).</p><p><b>CONCLUSION</b>UCP2 plays an important protective role against oxidative stress damage to human sperm by diminishing ROS production.</p>

Expression of uncoupling protein 2 on macrophages and its relation to interleukin-10/interferon ratio in patients with unexplained recurrent spontaneous abortion / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the relationship between the expression of uncoupling protein 2 (UCP2) and ratio of interleukin-10/interferon-gamma (IL10/IFNgamma) in the macrophages from patients with unexplained recurrent spontaneous abortion (URSA).</p><p><b>METHODS</b>Twelve women undergoing selective termination of normal early pregnancy (control) and 11 having URSA were included in this study. Magnetic cell sorting (MACS) was used to isolate the macrophages in the decidua, and the expression of UCP2 was detected with flow cytometry. Cytokine (IL10 and IFNgamma) secretion by the macrophages was detected by enzyme-linked immunosorbent spot-forming (ELISPOT) cell assay.</p><p><b>RESULTS</b>Compared to the control group, the women with URSA showed significantly decreased expression of UCP2 on decidual macrophage (136-/+25 vs 201-/+31, P<0.01), and the expression of UCP2 was positively correlated to the ratio of IL10/IFNgamma(r=0.73, P<0.01).</p><p><b>CONCLUSION</b>UCP2 may play an important role in the regulation of macrophage activity and cytokine secretion to contribute to spontaneous abortion.</p>

Uncoupling protein-2 expression in granular cells and embryo development in in vitro fertilization-embryo transfer cycle / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the expression of uncoupling protein-2 (UCP2) in the granular cell of women undergoing in vitro fertilization (IVF) and explore its role in embryo development.</p><p><b>METHODS</b>In this prospective study, the levels of UCP2 and reactive oxygen species (ROS) were measured by the chemiluminescence method in the granular cell of 53 women.</p><p><b>RESULTS</b>Women with low UCP2 level had higher ROS level, suggesting an inverse relationship between them (r=-0.578, P<0.01), and their oocyte development was impaired. Granular cells of elder women exhibited lowered UCP2 expression.</p><p><b>CONCLUSION</b>The granular cells increase UCP2 expression to suppress the elevation of intracellular ROS level through a feedback mechanism and therefore protect the oocytes against oxidative stress.</p>