Enhancing Near-Infrared Absorption in Terpyridyl Ru/Os Complexes with Ancillary Ligands to Activate Spin-Forbidden Transitions in Dye-Sensitized Solar Cells: A TDDFT Investigation.

Dye sensitizers with wideband absorption covering the near-IR region have long been of interest because they potentially harvest a wide range of solar energies essential to promote photocurrent power conversion efficiencies. In this study, we used time-dependent density functional theory with spin-orbit (SO) interactions to theoretically explore the long-wavelength absorptions and spin-forbidden triplet transitions activated by SO interactions for terpyridyl ruthenium/osmium complex dyes. These dyes feature a Ru(II) sensitizer coordinated with a phosphine ligand and are exemplified by DX1, denoted as [trans-dichloro-(phenyldimethoxyphosphine)(2,2';6',2″-terpyridyl-4,4',4″-tricarboxylic)Ru]. We found that ancillary ligands significantly affected the longest wavelength spin-allowed absorption, with NCS- ligands yielding longer wavelength S1 transitions than halides. High atomic number halide ligands caused blue shifts in the S1 transition. Os complexes consistently exhibited longer wavelength S1 transitions than Ru complexes with identical ligands. In Ru/Os complexes, ancillary ligands with higher atomic numbers have a more pronounced effect in activating spin-forbidden triplet transitions through spin-orbit coupling (SOC) than those with lower atomic numbers. The absorption wavelength of the SOC-activated transition primarily depended on the energy of lower lying triplet states. Some complexes exhibited T1 states activated by SOC, leading to longer wavelength absorption than that of SOC-activated T2 states. Our study revealed the significance of ancillary ligands and SOC interactions in Ru/Os complexes, offering insights for optimizing materials with enhanced long-wavelength absorption properties, particularly in the near-IR range, for photovoltaic and optoelectronic applications.

Electroactive Carbazole-Based Polycyclic Aromatic Hydrocarbons: Synthesis, Photophysical Properties, and Computational Studies.

Herein, we explored the oxidative coupling reactions of carbazole-based polycyclic aromatic hydrocarbons using traditional Scholl reactions and electrochemical oxidation. Our findings indicate that the oxidation predominantly occurs at the carbazole functional group. The underlying reaction mechanisms were also clarified through theoretical investigations, highlighting that the primary oxidation pathway involves the 3,6-positions of the carbazole moiety, which is attributable to its high electron density.

Effect of regio-specific arylamine substitution on novel π-extended zinc salophen complexes: density functional and time-dependent density functional study on DSSC applications.

A series of π-extended salophen-type Schiff-base zinc(ii) complexes, e.g., zinc-salophen complexes (ZSC), were investigated toward potential applications for dye-sensitized solar cells. The ZSC dyes adopt linear-, X-, or π-shaped geometries either with the functionalization of 1 donor/1 acceptor or 2 donors/2 acceptors to achieve a push-pull type molecular structure. The frontier molecular orbitals, light-harvesting properties as well as charge transfer characters against regio-specific substitution of donor/acceptor groups were studied by using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The results reveal that all ZSC dyes of D-ZnS-π-A geometry (where D, S, and A denote to donor, salophen ligand, and acceptor, respectively) exhibit relatively lower HOMO energy compared to the structurally resembled porphyrin dye YD2-o-C8. Natural transition orbital (NTO) and electron-hole separation (EHS) approaches clearly differentiate the linear type YD-series dyes from CL-, AJ1-, and AJ2-series dyes because of poor charge transfer (CT) properties. In contrast, the π-shaped AJ2-series and X-shaped AJ1-series dyes outperform the others in a manner of stronger CT characteristics, broadened UV-vis absorption as well as tunable bandgap simply via substitution of p-ethynylbenzoic acids (EBAs) and arylamine donors at salophen 7,8- and 2,3,12,13-positions, respectively. Both EHS and calculated exciton binding energies suggest the strength of CT character for ZSC dyes with an amino donor in the trend TPA > AN > DPA. This work has provided clear illustration toward molecular design of efficient dyes featuring a zinc-salophen backbone.

Effect of Thiophene Insertion on X-Shaped Anthracene-Based Hole-Transporting Materials in Perovskite Solar Cells.

In this work, two novel tetra-substituted X-shaped molecules X1 and X2 that were constructed with anthracene as the central core and arylamine as the donor groups have been synthesized. The HTMs X1 and X2 were synthesized in two steps from industrially accessible and moderately reasonable beginning reagents. These new HTMs are described in terms of utilization of light absorption, energy level, thermal properties, hole mobility (µh), and film-forming property. The photovoltaic performances of these HTMs were effectively assessed in perovskite solar cells (PSCs). The devices based on these HTMs accomplished an overall efficiency of 16.10% for X1 and 10.25% for X2 under standard conditions (AM 1.5 G and 100 mW cm-2). This precise investigation provides another perspective on the use of HTMs in PSCs with various device configurations.

Proliferating cell nuclear antigen clamp associated factor, a potential proto-oncogene with increased expression in malignant gastrointestinal tumors.

Gastrointestinal (GI) cancers, including malignancies in the gastrointestinal tract and accessory organs of digestion, represent the leading cause of death worldwide due to the poor prognosis of most GI cancers. An investigation into the potential molecular targets of prediction, diagnosis, prognosis, and therapy in GI cancers is urgently required. Proliferating cell nuclear antigen (PCNA) clamp associated factor (PCLAF), which plays an essential role in cell proliferation, apoptosis, and cell cycle regulation by binding to PCNA, is a potential molecular target of GI cancers as it contributes to a series of malignant properties, including tumorigenesis, epithelial-mesenchymal transition, migration, and invasion. Furthermore, PCLAF is an underlying plasma prediction target in colorectal cancer and liver cancer. In addition to GI cancers, PCLAF is also involved in other types of cancers and autoimmune diseases. Several pivotal pathways, including the Rb/E2F pathway, NF-κB pathway, and p53-p21 cascade, are implicated in PCLAF-mediated diseases. PCLAF also contributes to some diseases through dysregulation of the p53 pathway, WNT signal pathway, MEK/ERK pathway, and PI3K/AKT/mTOR signal cascade. This review mainly describes in detail the role of PCLAF in physiological status and GI cancers. The signaling pathways involved in PCLAF are also summarized. Suppression of the interaction of PCLAF/PCNA or the expression of PCLAF might be potential biological therapeutic strategies for GI cancers.

Upregulation of RAGE at the blood-brain barrier in streptozotocin-induced diabetic mice.

Deposition of amyloid-beta peptide (Abeta) in the brain of diabetes is poorly understood. The receptor for advanced glycation end products (RAGE) at the blood-brain barrier (BBB) is critical for regulation of Abeta homeostasis in the brain. In this studies, we used streptozotocin-induced diabetic mice to observe the expression of RAGE at the BBB by Western blot and immunocytochemical analysis, and the in vivo blood-to-brain influx transport of (125)I-Abeta(1-) (40) using the permeability surface area product (PS) and brain capillary uptake. In the diabetic mice with hyperglycemia (>16.0 mmol/L) at 6 weeks, RAGE expression at the BBB was significantly upregulated, no significant changes of RAGE levels were found at 1 and 3 weeks after diabetes induction. The data of PS and brain capillary uptake for Abeta showed significant RAGE-dependent transport of Abeta across the BBB and substantial RAGE-dependent brain capillary uptake at 6 weeks after diabetes induction. We conclude that the upregulation of RAGE at the BBB contributes to cerebral Abeta deposition in the diabetes.

PI3Kß inhibitor AZD6482 exerts antiproliferative activity and induces apoptosis in human glioblastoma cells.

Glioblastoma is the most common type of primary brain tumour in adults, and its pathogenesis is particularly complicated. Among the many possible mechanisms underlying its pathogenesis, hyperactivation of the PI3K/Akt pathway is essential to the occurrence and development of glioma through the loss of PTEN or somatic activating mutations in PIK3CA. In the present study, we investigated the effect of the PI3Kß inhibitor AZD6482 on glioma cells. The CCK-8 assay showed dose-dependent cytotoxicity in glioma cell lines treated with AZD6482. Additionally, AZD6482 treatment was found to significantly induce apoptosis and cell cycle arrest as detected using flow cytometry. Moreover, as shown using western blot analysis, the levels of p-AKT, p-GSK-3ß, Bcl-2, and cyclin D1 were decreased after AZD6482 treatment. In addition, we found that AZD6482 inhibited the migration and invasion of glioma cells as detected by wound healing and Transwell invasion assays. Taken together, our findings indicate that AZD6482 exerts an antitumour effect by inhibiting proliferation and inducing apoptosis in human glioma cells. AZD6482 may be applied as an adjuvant therapy to improve the therapeutic efficacy of glioblastoma treatment.

TGX-221 inhibits proliferation and induces apoptosis in human glioblastoma cells.

Glioblastoma is the most common type of primary brain tumor in adults, with high mortality and morbidity rates. More effective therapeutic strategies are imperative. Previous studies have shown that the known p110-ß-selective inhibitor TGX-221 blocks the activation of PKB/Akt in PTEN-deficient cells. We treated U87 and U251 glioblastoma cells with TGX-221 to determine the effect of TGX-221. We performed a Cell Counting Kit-8 (CCK-8) test, EDU staining and cell cycle distribution analysis and found that TGX-221 inhibited glioblastoma cell proliferation. Next, the effect of TGX-221 on cell apoptosis was investigated using flow cytometry. These results demonstrated that TGX-221 induced apoptosis in glioblastoma cells. Moreover, migration and invasion assays revealed that TGX-221 inhibited human glioblastoma cell migration and invasion. Collectively, our study revealed that TGX-221 could inhibit proliferation and induce apoptosis in glioblastoma cells.

Downregulation of LRP1 [correction of LPR1] at the blood-brain barrier in streptozotocin-induced diabetic mice.

Deposition of amyloid-beta peptide (Abeta) in the diabetic brain is poorly understood. Low-density lipoprotein receptor related protein 1(LRP1) at the blood-brain barrier (BBB) is critical for regulation of Abeta homeostasis in the brain. In this study, we used streptozotocin-induced diabetic mice to observe the expression of LRP1 at the BBB by Western blot and immunocytochemical analysis, and to study in vivo brain-to-blood efflux transport of 125I-Abeta1-40 using brain clearance studies. In the diabetic mice with hyperglycemia (>16.0 mmol/l) at 6 weeks, LRP1 expression at the BBB was significantly downregulated; no significant changes of LRP1 levels were found at 1 and 3 weeks after diabetes induction. The data of brain clearance studies for Abeta showed significant decrease in LRP1-dependent transport of Abeta across the BBB at 6 weeks after diabetes induction, while no significant changes of LRP1-dependent transport of Abeta across the BBB at 1 or 3 weeks after diabetes induction were apparent. We conclude that the downregulation of LRP1 at the BBB contributes to cerebral Abeta deposition in diabetes mellitus.