Discovery of Novel Coumarin-quinolinium Derivatives as Pan-KRAS Translation Inhibitors by Targeting 5'-UTR RNA G-Quadruplexes.

Hyperactivated KRAS mutations fuel tumorigenesis and represent attractive targets for cancer treatment. While covalent inhibitors have shown clinical benefits against the KRASG12C mutant, advancements for non-G12C mutants remain limited, highlighting the urgent demand for pan-KRAS inhibitors. RNA G-quadruplexes (rG4s) in the 5'-untranslated region of KRAS mRNA can regulate KRAS translation, making them promising targets for pan-KRAS inhibitor development. Herein, we designed and synthesized 50 novel coumarin-quinolinium derivatives, leveraging our previously developed rG4-specific ligand, QUMA-1. Notably, several compounds exhibited potent antiproliferative activity against cancer cells as pan-KRAS translation inhibitors. Among them, 15a displayed exceptional capability in stabilizing KRAS rG4s, suppressing KRAS translation, and consequently modulating MAPK and PI3K-AKT pathways. 15a induced cell cycle arrest, prompted apoptosis in KRAS-driven cancer cells, and effectively inhibited tumor growth in a KRAS mutant xenograft model. These findings underscore the potential of 15a as a pan-KRAS translation inhibitor, offering a novel and promising approach to target various KRAS-driven cancers.

Progress and Challenges Toward Effective Flexible Perovskite Solar Cells.

The demand for building-integrated photovoltaics and portable energy systems based on flexible photovoltaic technology such as perovskite embedded with exceptional flexibility and a superior power-to-mass ratio is enormous. The photoactive layer, i.e., the perovskite thin film, as a critical component of flexible perovskite solar cells (F-PSCs), still faces long-term stability issues when deformation occurs due to encountering temperature changes that also affect intrinsic rigidity. This literature investigation summarizes the main factors responsible for the rapid destruction of F-PSCs. We focus on long-term mechanical stability of F-PSCs together with the recent research protocols for improving this performance. Furthermore, we specify the progress in F-PSCs concerning precise design strategies of the functional layer to enhance the flexural endurance of perovskite films, such as internal stress engineering, grain boundary modification, self-healing strategy, and crystallization regulation. The existing challenges of oxygen-moisture stability and advanced encapsulation technologies of F-PSCs are also discussed. As concluding remarks, we propose our viewpoints on the large-scale commercial application of F-PSCs.

Surface Modification in CsPb0.5Sn0.5I2Br Inorganic Perovskite Solar Cells: Effects of Bifunctional Dipolar Molecules on Photovoltaic Performance.

Inorganic tin-lead binary perovskites have piqued the interest of researchers as effective absorbers for thermally stable solar cells. However, the nonradiative recombination originating from the surface undercoordinated Sn2+ cations and the energetic offsets between different layers cause an excessive energy loss and deteriorate the perovskite device's performance. In this study, we investigated two thioamide derivatives that differ only in the polar part connected to their common benzene ring, namely, benzenecarbothioamide and 4-fluorophenylcarbothioamide (F-TBA). These two molecules were implemented as modifiers onto the inorganic tin-lead perovskite (CsPb0.5Sn0.5I2Br) surface in the perovskite solar cells. Modifiers that carry C═S and NH2 functional groups, equipped with lone electron pairs, can autonomously associate with surface Sn2+ through coordination and electrostatic attraction mechanisms. This interaction serves effectively to passivate the surface. In addition, due to the permanent dipole moment of the intermediate layer, an interfacial dipole field appears at the PCBM/CsPb0.5Sn0.5I2Br interface, reducing the electron extraction potential barrier. Consequently, the planar solar cell with an ITO/PEDOT:PSS/CsPb0.5Sn0.5I2Br/PCBM/BCP/Ag layered structure featuring an F-TBA surface post-treatment demonstrated a noteworthy power conversion efficiency of 14.01%. Simultaneously, after being stored for 1000 h in an inert atmosphere glovebox, the non-encapsulated CsPb0.5Sn0.5I2Br solar cells managed to preserve 94% of their original efficiency.

Single-Crystal Nanowire Cesium Tin Triiodide Perovskite Solar Cell.

This work reports for the first time a highly efficient single-crystal cesium tin triiodide (CsSnI3 ) perovskite nanowire solar cell. With a perfect lattice structure, low carrier trap density (≈5 × 1010 cm-3 ), long carrier lifetime (46.7 ns), and excellent carrier mobility (>600 cm2 V-1 s-1 ), single-crystal CsSnI3 perovskite nanowires enable a very attractive feature for flexible perovskite photovoltaics to power active micro-scale electronic devices. Using CsSnI3 single-crystal nanowire in conjunction with highly conductive wide bandgap semiconductors as front-surface-field layers, an unprecedented efficiency of 11.7% under AM 1.5G illumination is achieved. This work demonstrates the feasibility of all-inorganic tin-based perovskite solar cells via crystallinity and device-structure improvement for the high-performance, and thus paves the way for the energy supply to flexible wearable devices in the future.

Discovery of Clinically Used Octenidine as NRAS Repressor That Effectively Inhibits NRAS-Mutant Melanoma.

Mutations in NRAS promote tumorigenesis and drug resistance. As this protein is often considered an undruggable target, it is urgent to develop novel strategies to suppress NRAS for anticancer therapy. Recent reports indicated that a G-quadruplex (G4) structure formed in the untranslated region of NRAS mRNA can downregulate NRAS translation, suggesting a potential NRAS suppression strategy. Here, we developed a novel cell-based method for large-scale screening of NRAS G4 ligand using the G-quadruplex-triggered fluorogenic hybridization probe and successfully identified the clinically used agent Octenidine as a potent NRAS repressor. This compound suppressed NRAS translation, blocked the MAPK and PI3K-AKT signaling, and caused concomitant cell cycle arrest, apoptosis, and autophagy. It exhibited better antiproliferation effects over clinical antimelanoma agents and could inhibit the growth of NRAS-mutant melanoma in a xenograft mouse model. Our results suggest that Octenidine may be a prominent anti-NRAS-mutant melanoma agent and represent a new NRAS-mutant melanoma therapy option.

Fabrication of High-Quality CsPbI3 Perovskite Films with Phosphorus Pentachloride Additive for Highly Stable Solar Cells.

Fully inorganic perovskite cesium lead triiodide (CsPbI3 ) has garnered much attention from researcher for photovoltaic application because of its excellent thermal stability compared with the inorganic-organic hybrid counterparts, along with the potential to serve as the top cell in tandem devices with silicon solar cell. However, the active α-phase cubic CsPbI3 spontaneously tends to transform into the non-perovskite δ-CsPbI3 when subjected to ambient condition. This work proposes an effective method to fabricate high-quality and stable α-phase cubic CsPbI3 films by introducing phosphorus pentachloride (PCl5 ) as an additive. PCl5 acts as colloidal binder for modulating crystallization dynamics of perovskites, resulting in high-quality film and a significantly suppressed phase transition. Finally, highly stable CsPbI3 perovskite solar cells can be achieved with a power conversion efficiency up to 17.85 %, and a long-term stability in N2 filled glove box.

Effects of regional citrate anticoagulation on thrombin generation, fibrinolysis and platelet function in critically ill patients receiving continuous renal replacement therapy for acute kidney injury: a prospective study.

BACKGROUND: Regional citrate anticoagulation (RCA) is recommended for continuous renal replacement therapy (CRRT). However, filter life varies and premature filter clotting can occur. The aims of this explorative prospective study were to investigate the effects of RCA on thrombin generation, fibrinolysis and platelet function in critically ill patients receiving CRRT, to compare clotting parameters between systemic and intra-circuit blood samples, and to screen participants for coagulation disorders. We recruited critically ill adult patients admitted to a 30-bedded Intensive care unit in a tertiary care hospital who required CRRT with RCA for acute kidney injury (AKI). Patients with pre-existing thrombotic, bleeding tendencies or a CRRT duration less than 48 h were excluded. We measured coagulation and thrombophilia parameters at baseline. Thrombin generation, D-dimer and platelet function were measured pre-CRRT and at 12, 24, 36, 48 and 72 h after commencing CRRT using blood samples taken from the arterial line and the circuit. RESULTS: At baseline, all eleven patients (mean age 62.4 years, 82% male) had Factor VIII and von Willebrand Factor concentrations above reference range and significantly increased peak thrombin generation. During CRRT, there were no significant changes in systemic maximum peak thrombin generation, time to peak thrombin generation, fibrinogen, D-dimer and platelet function analysis. We observed no significant difference between paired samples taken from the patient's arterial line and the circuit. CONCLUSIONS: Critically ill patients with AKI requiring CRRT are hypercoagulable. Citrate used for anticoagulation during CRRT does not affect thrombin generation, D-dimer or platelet function. Systemic clotting parameters reflect intra-circuit results. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02486614. Registered 01 July 2015-Registered after recruitment of first patient. https://clinicaltrials.gov/ct2/show/NCT02486614.

Local VOC Measurements by Kelvin Probe Force Microscopy Applied on P-I-N Radial Junction Si Nanowires.

This work focuses on the extraction of the open circuit voltage (VOC) on photovoltaic nanowires by surface photovoltage (SPV) based on Kelvin probe force microscopy (KPFM) measurements. In a first approach, P-I-N radial junction (RJ) silicon nanowire (SiNW) devices were investigated under illumination by KPFM and current-voltage (I-V) analysis. Within 5%, the extracted SPV correlates well with the VOC. In a second approach, local SPV measurements were applied on single isolated radial junction SiNWs pointing out shadowing effects from the AFM tip that can strongly impact the SPV assessment. Several strategies in terms of AFM tip shape and illumination orientation have been put in place to minimize this effect. Local SPV measurements on isolated radial junction SiNWs increase logarithmically with the illumination power and demonstrate a linear behavior with the VOC. The results show notably that contactless measurements of the VOC become feasible at the scale of single photovoltaic SiNW devices.

Tin dioxide nanoparticles as catalyst precursors for plasma-assisted vapor-liquid-solid growth of silicon nanowires with well-controlled density.

The fabrication of arrays of silicon nanowires (Si NWs) with well-defined surface coverage using the vapor-liquid-solid process requires a good control of the density and size distribution for the metal catalyst. We report on a cost-effective bottom-up approach to produce Si NWs by a low-temperature deposition technology using plasma-enhanced chemical vapor deposition and tin dioxide (SnO2) nanoparticles as the source of tin catalyst. This strategy offers a straightforward method to select specific particle sizes by conventional colloidal techniques, and to tune the surface coverage using a polyelectrolyte layer to efficiently immobilize the particles on the substrate by electrostatic grafting. After a further step of reduction into tin metal droplets using hydrogen plasma treatment, the catalyst particles are used for the growth of Si NWs. This approach allows the prodcution of controlled Si NWs arrays which can be used as a template for radial junction thin film solar cells.

Longitudinal Study of the Effects of Environmental pH on the Mechanical Properties of Aspergillus niger.

The regulation of environmental pH is key to the health of an ecosystem, influencing the metabolic activity, growth, and development of organisms within it. Although pH values can be measured by a wide range of readily available technologies ranging from fluorescent dyes and nanosensors, these cannot reveal the history of environmental pH from before monitoring begins. This information is sometimes crucial for piecing together what has happened to an ecosystem, and our long-term goal is therefore to develop technologies capable of obtaining it. Here, we propose monitoring environmental pH over time by tracking mechanical properties of a common fungus. As a first step toward obtaining a time history of pH, we evaluate the effect of pH upon the effective indentation modulus of spores and hyphae of Aspergillus niger. We report that the indentation modulus of this phosphorus-solubilizing fungus, obtained through atomic force microscopy and nanoindentation, correlated with environmental acidity. We observed a significant, monotonic increase in moduli over the course of incubation in an acidic environment, but no change in moduli over time for incubation in a neutral environment. Results show promise for using our scheme to detect and track environmental pH over time, and more broadly for using a microorganism's mechanical properties as a biomarker for environmental detection.

Homocysteine metabolism and the associations of global DNA methylation with selected gene polymorphisms and nutritional factors in patients with dementia.

Epigenetics (particularly DNA methylation) together with environmental and genetic factors, are key to understanding the pathogenesis of many diseases including dementia. Disturbances in DNA methylation have already been implicated in dementia. Homocysteine metabolism, with folate and vitamin B12 as essential cofactors, is integral to methylation processes. We evaluated in a case-control study the association of global DNA methylation, homocysteine, folate and vitamin B12 status with dementia. Selected polymorphisms of genes previously associated with dementia development and the influence of various factors on DNA methylation were also investigated. 102 patients with dementia (53 with Alzheimer's disease, 17 with vascular dementia and 32 with mixed dementia) were recruited. The non-demented controls consisted of 45 age-matched subjects without dementia and 47 individuals with mild cognitive impairment. Global DNA methylation was determined by Imprint Methylated DNA Quantification Kit MDQ1 (Sigma-Aldrich, Gillingham, Dorset, UK). Plasma homocysteine, serum folate and vitamin B12 were determined by chemiluminescence. Plasma and erythrocyte 5-methyltetrahydrofolate and plasma methylmalonic acid (markers of folate and vitamin B12 status) were measured by HPLC. APOE, PON1 p.Q192R, MTHFR 677C>T (c.665C>T) and IL1B-511C>T polymorphisms were identified using PCR-RFLP methods. Patients with dementia had significantly higher concentrations of homocysteine (p=0.012) and methylmalonic acid (p=0.016) and lower folate (p=0.002) and plasma 5-methyltetrahydrofolate (p=0.005) than non-demented subjects. There was no difference in DNA methylation between patients and controls. A non-significant tendency to higher DNA methylation in patients with vascular dementia (p=0.061) was observed. Multivariate regression analysis of all recruited individuals demonstrated a significant positive association between DNA methylation and folate (p=0.013), creatinine (p=0.003) concentrations and IL1B-511T (p=0.002) and PON1 192R (p=0.049) alleles and negative association with fasting glucose (p=0.004). The biochemical results showed significantly lower folate and vitamin B12 status in demented patients than controls. Global DNA methylation was associated with markers of folate status, creatinine, glucose and PON1 and IL1B polymorphisms.

A study of organic acid production in contrasts between two phosphate solubilizing fungi: Penicillium oxalicum and Aspergillus niger.

Phosphate solubilizing fungi (PSF) have huge potentials in enhancing release of phosphorus from fertilizer. Two PSF (NJDL-03 and NJDL-12) were isolated and identified as Penicillium oxalicum and Aspergillus niger respectively in this study. The quantification and identification of organic acids were performed by HPLC. Total concentrations of organic acids secreted by NJDL-03 and NJDL-12 are ~4000 and ~10,000 mg/L with pH values of 3.6 and 2.4 respectively after five-days culture. Oxalic acid dominates acidity in the medium due to its high concentration and high acidity constant. The two fungi were also cultured for five days with the initial pH values of the medium varied from 6.5 to 1.5. The biomass reached the maximum when the initial pH values are 4.5 for NJDL-03 and 2.5 for NJDL-12. The organic acids for NJDL-12 reach the maximum at the initial pH = 5.5. However, the acids by NJDL-03 continue to decrease and proliferation of the fungus terminates at pH = 2.5. The citric acid production increases significantly for NJDL-12 at acidic environment, whereas formic and oxalic acids decrease sharply for both two fungi. This study shows that NJDL-12 has higher ability in acid production and has stronger adaptability to acidic environment than NJDL-03.

Two nonsense mutations cause protein C deficiency by nonsense-mediated mRNA decay.

INTRODUCTION: Protein C deficiency is a genetic disorder caused by mutations in the protein C gene (PROC). More than 10% of nonsense and frameshift mutations carrying premature termination codons have been identified in PROC, but the exact molecular mechanisms of these mutations on the pathogenesis of protein C deficiency remain unclear. OBJECTIVE: The aim of this study is to investigate whether nonsense-mediated mRNA decay (NMD) can be a mechanism accounting for protein C deficiency. METHODS: PROC of genomic DNA was amplified and sequenced. Recombinant plasmids expressing wild-type (wt) and mutant EGFP-protein C (EGFP-PC) cDNA were constructed and transiently transfected into human embryonic kidney cells using lipofectamine. Expression of mRNAs and proteins of EGFP-PC and NMD factor UPF1 were analyzed by qPCR and Western blot. RESULTS: DNA sequencing revealed a novel heterozygous nonsense mutation (p.Trp247*) in patient 1 and two compound heterozygous mutations (p.Phe181Val and p.Arg199*) in patient 2. Expression studies showed that cells transfected with the mutant plasmids expressed significantly lower levels of EGFP-PC mRNAs and proteins compared to cells transfected with the wt plasmid. A translation inhibitor cycloheximide and UPF1 small interfering RNA (UPF1 siRNA) significantly increased mRNA or protein expression of EGFP-PC in cells transfected with the mutant plasmids. CONCLUSION: Two PROC nonsense mutations (p.Trp247* and p.Arg199*) trigger NMD, resulting in protein C deficiency.

Molecular basis and bleeding manifestations of factor XI deficiency in 11 Turkish families.

Factor XI (FXI) deficiency is an autosomal bleeding disorder characterized by variable bleeding tendency. In the present study, the gene encoding FXI (F11) was analyzed by direct sequencing in 33 individuals belonging to 11 unrelated Turkish families, and the bleeding tendency was quantitatively assessed by means of a bleeding questionnaire in 27 individuals with low FXI clotting activity and/or mutated F11 gene. We identified 10 distinct mutations (five missense, three nonsense and two splice site), four of which were novel. No mutation was found in one family. Of the four novel mutations, homozygosity for a c.89T>C (p.Phe30Ser) mutation and compound heterozygosity for a c.646G>A (p.Asp216Asn) mutation with the known c.403G>T (p.Glu135) type II Jewish mutation were associated with severe deficiency, whilst heterozygosity for the novel c.1655A>C (p.His552Arg) and c.1627G>A (p.Glu543Lys) mutations was associated with partial deficiency. p.Glu135 was found in 19% (5/27) of the mutated alleles. Bleeding score was positive in 57% (4/7) of individuals with severe and 39% (7/18) of those with partial deficiency. It was significantly correlated with clinical severity of bleeding (r = 0.43, P = 0.02), but not with FXI clotting activity (P > 0.05). There was no optimal cut-off level of the bleeding score that could predict FXI deficiency. We conclude that the spectrum of mutations found in this study reflects the genetic heterogeneity of FXI deficiency in the Turkish population. Quantitative assessment of the bleeding symptoms by a bleeding questionnaire seems to be useful for evaluating the severity of bleeding episodes, but it can not be recommended as a screening tool for FXI deficiency.

Characterisation of five factor XI mutations.

A large scale factor XI (FXI) mutation screening program identified a number of novel candidate mutations and previously reported mutations and polymorphisms. Five potential missense mutations were selected for further study; these included two novel missense mutations - Met-18Ile (p.Met1Ile) and Met102Thr (p.Met120Thr), two previously reported missense mutations - Tyr133Ser (Tyr151Ser) and Thr575Met (Thr593Met), and one amino acid substitution previously reported as a polymorphism - Arg378Cys (Arg396Cys). The substitutions were recreated by the site-directed mutagenesis of a FXI cDNA and stably expressed in a BHK-570 cell line. Subsequent analysis of both the conditioned media and cell lysates showed that three of the substitutions, Met-18Ile, Met102Thr andTyr133Ser, prevented secretion of the mutated protein from the transfected cell line, resulting in a cross-reactive material negative (CRM-) phenotype. The remaining two mutants, Thr575Met and Arg378Cys, secreted significant levels of FXI into the conditioned media; however, these mutant FXIs were shown to have negligible factor IX activation activity in an APTTbased assay. These results confirmed all five of the missense mutations as being causative of factor XI deficiency, despite one having been previously reported as a polymorphism (Arg378Cys) and one (Tyr133Ser) as a mild mutation - FXI:C 38 U/dl in a homozygous patient.

Spectrum of factor XI (F11) mutations in the UK population--116 index cases and 140 mutations.

Factor XI deficiency is an autosomal bleeding disorder of variable severity. It is particularly common in the Ashkenazi Jewish population, the result of two founder mutations - E117X and F283L. Recent studies have shown the causative mutations of Factor XI deficiency, outside the Ashkenazi Jewish population, to be highly heterogeneous. We have studied 116 index cases, mostly from an ethnically diverse UK population, in order to better understand the spectrum of mutations responsible for factor XI deficiency. A total of 140 causative mutations of the F11 gene were identified in 109 patients. Fifty-five (39.3%) of the mutations were one of three common mutations--E117X (Type II), F283L (Type III), or C128X. The remaining 85 (60.7%) mutations comprised at least 57 variants including 31 novel mutations and whole gene deletions. This large study reconfirms that, despite the presence of founder mutations in discrete populations, factor XI deficiency remains a highly heterogeneous disease at the molecular level. .

An Alu-mediated 31.5-kb deletion as the cause of factor XI deficiency in 2 unrelated patients.

Factor XI deficiency (MIM 264900) is an autosomal bleeding disorder of variable severity. Inheritance is not completely recessive as heterozygotes may display a distinct, if mild, bleeding tendency. Recent studies have shown the causative mutations of factor XI deficiency, outside the Ashkenazi Jewish population, to be highly heterogeneous. We studied 39 consecutively referred patients with factor XI deficiency to identify the molecular defect. Conventional mutation screening failed to identify a causative mutation in 4 of the 39 patients. Epstein-Barr virus (EBV)-transformed cells from these 4 patients were converted from a diploid to haploid chromosome complement. Subsequent analysis showed that 2 of the patients had a large deletion, which was masked in the heterozygous state by the presence of a normal allele. We report here the first confirmed whole gene deletion as the causative mutation of factor XI deficiency, the result of unequal homologous recombination between flanking Alu repeat sequences.