Designing Nonfullerene Acceptors with Oligo(Ethylene Glycol) Side Chains: Unraveling the Origin of Increased Open-Circuit Voltage and Balanced Charge Carrier Mobilities.

Despite the recent rapid development of organic solar cells (OSCs), the low dielectric constant (ϵr =3-4) of organic semiconducting materials limits their performance lower than inorganic and perovskite solar cells. In this work, we introduce oligo(ethylene glycol) (OEG) side chains into the dicyanodistyrylbenzene-based non-fullerene acceptors (NIDCS) to increase its ϵr up to 5.4. In particular, a NIDCS acceptor bearing two triethylene glycol chains (NIDCS-EO3) shows VOC as high as 1.12 V in an OSC device with a polymer donor PTB7, which is attributed to reduced exciton binding energy of the blend film. Also, the larger size grain formation with well-ordered stacking structure of the NIDCS-EO3 blend film leads to the increased charge mobility and thus to the improved charge mobility balance, resulting in higher JSC , FF, and PCE in the OSC device compared to those of a device using the hexyl chain-based NIDCS acceptor (NIDCS-HO). Finally, we fabricate NIDCS-EO3 devices with various commercial donors including P3HT, DTS-F, and PCE11 to show higher photovoltaic performance than the NIDCS-HO devices, suggesting versatility of NIDCS-EO3.

Changes in lipid peroxidation and antioxidant trace elements in serum of women with cervical intraepithelial neoplasia and invasive cancer.

This study investigated serum lipid peroxidation, antioxidant capacity, and trace element levels in Korean women as related to uterine cervical neoplasia. Twenty-eight subjects had cervical intraepithelial neoplasia (CIN), 36 had invasive cervical cancer, as determined by a colposcopically directed biopsy, and controls included 44 subjects with normal colposcopic findings. Significantly lower selenium (Se) and zinc (Zn) levels and higher copper/Zn ratios were found in both CIN and cancer patients compared with the controls. Serum malondialdehyde levels decreased significantly in the order CIN>cancer>control, implying the involvement of reactive oxygen species at the precancerous stage, that is, prior to progression into invasive cervical cancer. Serum glutathione peroxidase activity was significantly lower in patients with CIN or cancer than controls, and total antioxidant ability decreased from controls to CIN to cancer (P < 0.0001). This study demonstrated the involvement of lipid peroxidation, decreased Se and Zn levels, and an impaired serum antioxidant system in the pathogenesis of cervical dysplasia. Further research is needed to examine the possibility of an effective chemopreventive treatment in cervical cancer based on enhancing the endogenous antioxidant system.