| 1. |
- Cui, Peng, et al.
(författare)
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Long-term androgen excess induces insulin resistance and non-alcoholic fatty liver disease in PCOS-like rats.
- 2021
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Ingår i: The Journal of steroid biochemistry and molecular biology. - : Elsevier BV. - 1879-1220 .- 0960-0760. ; 208
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Tidskriftsartikel (refereegranskat)abstract
- Women with polycystic ovary syndrome (PCOS) are at higher risk for metabolic disorders compared to healthy women, and about 51 % of women with PCOS suffer from non-alcoholic fatty liver disease (NAFLD). Investigation into the pathological mechanism behind this association will provide insights for the prevention and treatment of this complication.Dihydrotestosterone (DHT), a nonaromatic androgen, was used to mimic the pathological conditions of hyperandrogenism and insulin resistance. Hematoxylin and eosin staining, Oil Red O staining, immunofluorescent staining, Western blots, and qRT-PCR were used to verify the hepatic steatosis and inflammation, and the latter two methods were also used for energy and mitochondrion-related assays. ELISA was used to measure the level of reactive oxygen species.Twelve weeks of DHT exposure led to obesity and insulin resistance as well as hepatic steatosis, lipid deposition, and different degrees of inflammation. The expression of molecules involved in respiratory chain and aerobic respiration processes, such as electron transfer complex II, pyruvate dehydrogenase, and succinate dehydrogenase complex subunit A, was inhibited. In addition, molecules associated with apoptosis and autophagy were also abnormally expressed, such as increased Bak mRNA, an increased activated caspase-3 to caspase-3 ratio, and increased Atg12 protein expression. All of these changes are associated with the mitochondria and lead to lipid deposition and inflammation in the liver.Long-term androgen excess contributes to insulin resistance and hepatic steatosis by affecting mitochondrial function and causing an imbalance in apoptosis and autophagy, thus suggesting the pathogenesis of NAFLD in women with PCOS.
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| 2. |
- Hu, Jutao, et al.
(författare)
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Effects of NH4+ doping on the hydrogen storage properties of metal hydrides
- 2023
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Ingår i: International journal of hydrogen energy. - : Elsevier Ltd. - 0360-3199 .- 1879-3487. ; 48:50, s. 19153-19159
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Tidskriftsartikel (refereegranskat)abstract
- Doping can modify the properties of metal hydrogen storage materials significantly. Currently, the metal doping is a frequent strategy, while the non-metal cation doping has not been examined extensively so far. In this study, the effects of NH4+ doping on the hydrogen storage properties of different metal hydrides, including TiH2, Ti0·25V0·25Nb0·25Zr0·25H2, Ti0·5V0·5H2 and VH2, are investigated by first-principles calculations. It is found that the NH4+ presents a good affinity for metal hydrides and the NH4+ incorporation leads to charge redistribution and formation of dihydrogen bond. Furthermore, the NH4+ doping in metal hydrides is favorable for enhancing the hydrogen storage capacity and decreasing the thermal stability simultaneously. The possible reason for the NH4+ doping induced destabilization in metal hydrides is the relatively weak interaction between NH4+ and hydrogen atoms.
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| 3. |
- Hu, Jutao, et al.
(författare)
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The origin of anomalous hydrogen occupation in high entropy alloys
- 2022
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 10:13, s. 7228-7237
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Tidskriftsartikel (refereegranskat)abstract
- Metal hydrogen storage materials have been the focus of intensive research in the field of hydrogen-based economy. An outstanding question is that the number of hydrogen atoms accommodated in metal hydrides is generally much below the number of interstices, which limits their hydrogen storage capacities. Unlike traditional FCC metal hydrides where hydrogen can only occupy tetrahedral interstices, this study demonstrates that hydrogen can also occupy octahedral interstices in FCC high entropy alloy (HEA) hydrides, which leads to the violation of the Switendick criterion. For Ti25V25Nb25Ta25 and Ti25V25Nb25Zr25 HEAs, nearly 20% and 17.5% of octahedral interstices can be occupied by hydrogen, respectively. The anomalous hydrogen occupation mainly originates from the intrinsic electron delocalization between hydrogen atoms in HEA hydrides, which presents a sharp contrast to traditional metal hydrides. Such electron delocalization decreases repulsive interactions between hydrogens and promotes the electron localization at octahedral interstices. Additionally, this study reveals that hydrogen occupation at octahedral interstices enhances the structural disordering and decreases the thermal stability of HEA hydrides, which will be beneficial to reduce the dehydrogenation temperature. The presented results may provide a new strategy for the design of high-density storage materials.
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| 4. |
- Qu, Jishuang, et al.
(författare)
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Improved performance and air stability of perovskite solar cells based on low-cost organic hole-transporting material X60 by incorporating its dicationic salt
- 2018
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Ingår i: Science in China Series B. - : Science Press. - 1674-7291 .- 1869-1870. ; 61:2, s. 172-179
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Tidskriftsartikel (refereegranskat)abstract
- The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)(2), and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10(-6) to 10(-4) S cm(-1). The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm(-2), AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)(2) also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)(2) doped HTM layer, which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.
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| 5. |
- Schäfer, Sarah K., et al.
(författare)
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To sleep or not to sleep, that is the question : A systematic review and meta-analysis on the effect of post-trauma sleep on intrusive memories of analog trauma
- 2023
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Ingår i: Behaviour Research and Therapy. - : Elsevier. - 0005-7967 .- 1873-622X. ; 167
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Forskningsöversikt (refereegranskat)abstract
- Distressing intrusive memories of a traumatic event are one of the hallmark symptoms of posttraumatic stress disorder. Thus, it is crucial to identify early interventions that prevent the occurrence of intrusive memories. Both, sleep and sleep deprivation have been discussed as such interventions, yet previous studies yielded contradicting effects. Our systematic review aims at evaluating existing evidence by means of traditional and individual participant data (IPD) meta-analyses to overcome power issues of sleep research. Until May 16th, 2022, six databases were searched for experimental analog studies examining the effect of post-trauma sleep versus wakefulness on intrusive memories. Nine studies were included in our traditional meta-analysis (8 in the IPD meta-analysis). Our analysis provided evidence for a small effect favoring sleep over wakefulness, log-ROM = 0.25, p < .001, suggesting that sleep is associated with a lower number of intrusions but unrelated to the occurrence of any versus no intrusions. We found no evidence for an effect of sleep on intrusion distress. Heterogeneity was low and certainty of evidence for our primary analysis was moderate. Our findings suggest that post-trauma sleep has the potential to be protective by reducing intrusion frequency. More research is needed to determine the impact following real-world trauma and the potential clinical significance.
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| 6. |
- Sun, Zhengyi, 1982-, et al.
(författare)
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Buffer-enhanced electron injection in organic light-emitting devices with copper cathode
- 2013
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Ingår i: Organic electronics. - Amsterdam : Elsevier. - 1566-1199 .- 1878-5530. ; 14:2, s. 511-515
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Tidskriftsartikel (refereegranskat)abstract
- We explore in this work the use of Cu as a cathode material in organic light-emitting devices (OLEDs) and find a dual electron–injection enhancement mechanism derived from the LiF layer. Different from what observed previously in Ag- and Au-cathode devices, the LiF buffer layer in the Cu-cathode OLEDs starts to play its role in performance improvement when it is much thinner than 3 nm, the optimal value of buffer thickness, and in the case of optimal thickness, the device exhibits excellent performance comparable to conventional Al-cathode device. The phenomenon observed is ascribed to enhanced electron injection as a result of combined effect of interfacial reaction and tunneling barrier reduction mechanism: while chemical reaction plays a key role at the very beginning of interface formation, tunneling dominates in the subsequent stage leading to the tremendous improvement of the characteristics.
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| 7. |
- Yu, Ze, et al.
(författare)
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High-efficiency perovskite solar cells employing a conjugated donor-acceptor co-polymer as a hole-transporting material
- 2017
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Ingår i: RSC Advances. - : ROYAL SOC CHEMISTRY. - 2046-2069. ; 7:44, s. 27189-27197
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we have successfully introduced 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) as an efficient p-type dopant for donor-acceptor (D-A) co-polymer poly[2,6-(4,4-bis-(2ethylhexyl)- 4H-cyclopenta[2,1-b; 3,4-b'] dithiophene)-alt-4,7(2,1,3-benzothiadiazole)] (PCPDTBT) as an HTM in mesoscopic perovskite solar cells (PSCs). The bulk conductivity is significantly enhanced by 4 orders of magnitude when PCPDTBT is doped with F4TCNQ (6%, w/w). UV-vis and Fourier transform infrared spectroscopy (FTIR) results indicate the occurrence of p-doping, which results in higher bulk conductivity. The high conductivity leads to an impressive overall efficiency of 15.1%, which is considerably higher than the pristine PCPDTBT based devices (9.2%). The superior performance obtained should be largely attributed to the significant enhancement of the photocurrent density strongly correlated with a more efficient charge collection. This is the highest efficiency reported so far for PCPDTBT-based PSCs. Thus, molecularly p-doping has been demonstrated to be an effective strategy for further improving the performance of a wide range of D-A and other types of polymeric HTMs in PSCs.
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| 8. |
- Zhang, Feifei, et al.
(författare)
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Diversity of the Gut Microbiota in Dihydrotestosterone-Induced PCOS Rats and the Pharmacologic Effects of Diane-35, Probiotics, and Berberine. : Gut Microbiota in Dihydrotestosterone-Induced PCOS Rats
- 2019
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Ingår i: Frontiers in microbiology. - : Frontiers Media SA. - 1664-302X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Polycystic ovary syndrome (PCOS) is a frequent endocrine and metabolic syndrome in reproductive-age women. Recently, emerging evidence has shown that gut microbiota is closely related to metabolic diseases such as type 2 diabetes, obesity and PCOS. In the present study, we established dihydrotestosterone (DHT)-induced PCOS rats and used Illumina MiSeq sequencing (PE300) to examine the composition, diversity, and abundance of the gut microbiota in PCOS. We compared the effects of three PCOS treatments: Diane-35 (estrogen and progesterone), probiotics and berberine. The DHT-induced rats showed constant estrous cycles, the loss of mature ovarian follicles, insulin resistance and obesity. The reproductive and metabolic functions in the PCOS rats were improved by treatment with Diane-35 and probiotics. Diane-35 and probiotics could restore the diversity of the gut microbiota, and the recovery of gut microbiota disorders improved the reproductive function in PCOS-like rats. However, berberine drastically reduced the species diversity and amount of gut microbiota and showed no improvement in PCOS. The findings of this study will help us to better understand the influence of the gut microbiota in the metabolic and reproductive alterations in PCOS as well as suggest opportunities for future personal dietary guidance for PCOS.
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