Two series of novel boron–dipyrromethene (BODIPY) dyes containing 8-phenyl groups have been synthesized and their spectral properties have been studied. Series
2 with four methyl groups at ...1,3,5,7-positions show much higher fluorescence quantum yields and extinction coefficients than series
1 (without methyl groups). The “push–pull” electronic effect caused by the methyl groups at 3 and 5 positions is a significant positive factor to the high quantum yields of
2. The X-ray structure analysis of
1c and
2c reveals that steric expulsion exists between the phenyl and adjacent two methyl groups. Moreover, the steric expulsion might block the intramolecular vibronic relaxation and internal conversion of the excited
2, which also contributes to their high fluorescence quantum yields. The substituent effects on photostability and redox potentials of these dyes have been discussed.
Perfluoroalkyl substances (PFASs) have recently attracted increasing concerns due to their ubiquitous existence, adverse effects and persistence in environment. This study employed four ...perfluorinated carboxylic acids (PFCAs) to examine effects of salinity and temperature on the PFAS uptake in wheat, one of the major crops in the North China Plain. Wheat plants were grown in the spiked-PFCA hydroponic culture system at different salinities and temperatures. As expected, salinity and temperature significantly impacted the root uptake and translocation of wheat to four PFCAs, and the concentrations for each of PFCAs in wheat root and shoot increased with increasing salinity and temperature, respectively. PFCA concentrations at high salinity or high temperature were up to thrice those found at low salinity or low temperature. Except for perfluorobutanoic acid, the amount of PFCAs in root was always higher than that in shoot at the ranges of salinity and temperature tested. Additionally salinity and temperature were also capable of influencing the transfer factors (TFs) of four PFCAs, and significant increase was observed in the TFs in response to the increases in salinity and temperature.
A large number of neuroanatomical, neurophysiologic, and neurochemical mechanisms are thought to contribute to the development and maintenance of neuropathic pain. However, mechanisms responsible for ...neuropathic pain have not been completely delineated. It has been demonstrated that neuropeptide galanin (Gal) is upregulated after injury in the dorsal root ganglion (DRG) and spinal dorsal horn (SDH) where it plays a predominantly antinociceptive role. In the present study, sciatic nerve-pinch injury rat model was used to determine the effects of exogenous Gal on the expression of the Gal and its receptors (GalR1, GalR2) in DRG and SDH, the alterations of pain behavior, nerve conduction velocity (NCV) and morphology of sciatic nerve. The results showed that exogenous Gal had antinociceptive effects in this nerve-pinch injury induced neuropathic pain animal model. It is very interesting that Gal, GalR1 and GalR2 change their expression greatly in DRG and SDH after nerve injury and intrathecal injection of exougenous Gal. Morphological investigation displays a serious damage after nerve-pinch injury and an amendatory regeneration after exogenous Gal treatment. These findings imply that Gal, via activation of GalR1 and/or GalR2, may have neuroprotective effects in reducing neuropathic pain behaviors and improving nerve regeneration after nerve injury.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Biasing the conformational preferences of aromatic oligoamides by internally placing intramolecular hydrogen bonds has led to a series of stably folded molecular strands. This article presents the ...results from extensive solid-state, solution, and computational studies on these folding oligomers. Depending on its backbone length, an oligoamide adopts a crescent or helical conformation. Surprisingly, despite the highly repetitive nature of the backbone, the internally placed, otherwise very similar intramolecular hydrogen bonds showed significantly different stabilities as demonstrated by hydrogen−deuterium exchange data. It was also observed that the hydrogen-bonding strength can be tuned by adjusting the substituents attached to the exterior of the aromatic backbones. Examining the amide hydrogen−deuterium exchange rates of trimers revealed that a six-membered hydrogen bond nearing the ester end is the weakest among all the four intramolecular hydrogen bonds of a molecule. This observation was verified by ab initio quantum mechanical calculations at the level of B3LYP/6-31G*. Such a “weak point” creates the “battle of the bulge” where backbone twisting is centered, which is consistently observed in the solid-state structures of the four trimer molecules studied. In the solid state, the oligomers assemble into interesting one-dimensional structures. A pronounced columnar packing of short oligomers (i.e., dimers, trimers, and tetramer) and channel-like, potentially ion-conducting stacks of longer oligomers (i.e., tetramer, pentamer, and hexamer) were observed.
Aim
Cyclin E1‐driven ovarian cancer (OvCa) is characterized with metabolic shift. In this study, we aim to pinpoint the metabolic pathway altered and assess its therapeutic potential.
Methods
In ...silico reproduction of TCGA ovarian cancer dataset and functional annotation using GSEA was performed. Candidate metabolic pathway was validated using in vitro and in vivo assays.
Results
From TCGA database, we found that polyamine metabolism was significantly enriched in Cyclin E1‐driven OvCa. Expressions of SMS, SRM, and ODC1 were positively correlated with that of CCNE1, respectively. ODC1 and SMS expressions were significantly correlated with decreased immune infiltrates. PGC‐1α silencing significantly decreased invasion and migration in both OvCa cell lines. Both spermidine and spermine levels were significantly increased when PGC‐1α was silenced. Targeting SRM significantly decreased spermine level in OVCAR3 cells, which was rescued when PGC‐1α was silenced. Silencing of PGC‐1α resulted in increased SRM in both OvCa cells. Dinaciclib significantly decreased invasion and migration of OVCAR3 cells. Expressions of PD‐L1 and PD‐L2 were predominantly in tumor‐infiltrating lymphocytes. Dinaciclib showed no notable effect of PD‐1 yet substantially induced the increased levels of PD‐L1 and PD‐L2.
Conclusion
Cyclin E1‐driven OvCa is characterized with activated polyamine synthesis, which is associated with decreased cancer immunity. Targeting polyamine and CDK2 may therefore sensitize this genotype to immune checkpoint blockade.
Cyclin E1‐driven ovarian cancer shows metabolic shift that is mediated by GCN5/PGC‐1α axis. Combination therapy targeting both CDK2 and GCN5 hold promise for combating Cyclin E1‐driven ovarian cancer.
Abstract
Background
Astragalin
(AG), a flavonoid from many traditional herbs and medicinal plants, has been described to exhibit in vitro anti-inflammatory activity. The paper aimed to study the ...effects of
astragalin
on anti-inflammatory, anti-oxidative ability and apoptosis signaling pathway in brain tissue of rats with cerebral ischemia-reperfusion injury, and to explore its possible mechanism.
Methods
The rat model of focal cerebral ischemia-reperfusion injury was established by suture method. It was randomly divided into 5 groups, sham operation group, ischemia-reperfusion (I/R) treatment group, and
astragalin
treatment I / R group (12.5, 25, 50 mg / kg). After 24 h of reperfusion, the neurological deficits of the rats were analyzed and HE staining was performed. The volume of cerebral infarction was calculated by triphenyltetrazolium chloride (TTC) staining, and the apoptosis of nerve cells was detected by TUNEL staining. In addition, the content of malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), glutathione (GSH) assay and glutathione peroxidase (GSH-Px) were measured in rat brain tissue. Western blot analysis was used to determine the expression of related proteins.
Results
Compared with I/R group, the neurological deficit score and infarct volume of I/R rats were reduced in the
astragalin
treatment group. In the
astragalin
treatment group, MDA and NO levels in I/R rats were reduced, antioxidant enzymes and superoxide dismutase (SOD) activity were increased. In the
astragalin
treatment group, NF-κB (p65) and cyclooxygenase-2 (COX-2) expression levels were down-regulated, NF-E2-related factor 2 (Nrf2) nucleus and heme oxygenase-1 (HO-1) protein expression levels were up-regulated. In addition, the
astragalin
treatment can inhibit apoptosis, down-regulate Bax and cleaved caspase-3 expression, up-regulate Bcl-Xl expression.
Conclusion
The antioxidant properties of
astragalin
may play an important role in improving cerebral ischemia-reperfusion injury.
Entrepreneurial activity has been documented as an important mechanism to achieve poverty alleviation. In line with this, providing access to entrepreneurial finance for disadvantaged groups has been ...a prominent policy tool. The advent of digital finance may prove a game changer in that it could substantially lower the threshold to access entrepreneurial finance, particularly for disadvantaged entrepreneur who have a hard time accessing formal sources of finance. This study explores whether the availability of digital finance indeed increases the propensity and the quality of entrepreneurship among Chinese migrants. The paper applies data of the China Migrants Dynamic Survey in 2018 and the China's digital financial inclusion index. The results show that local digital financial development is indeed positively associated with entrepreneurial probability and quality. Moreover, the three sub-dimensions of digital finance (e.g., breadth of coverage, depth of use and level of digitization) also increase the likelihood of migrants' entrepreneurship. From the perspective of entrepreneurial motivation, digital finance has a significant positive impact on not only the migrants' choice of necessity-based entrepreneurship, but also on the selection of opportunity-based entrepreneurship. In addition, this paper finds that the facilitating role of digital finance on entrepreneurship is more prominent for migrants who lived in rural regions, with lower educational levels, experienced cross-provincial mobility, not belonging to a member of party organization and whose parents do not have good education background and local hukou, which reflects the inclusiveness of digital finance in reversing the financing disadvantage of vulnerable groups. Though this study is set in the context of China, the principle that access to digital finance increases the propensity of entrepreneurship as well as its quality likely translates to other contexts in the developing world.
•The rise of digital finance has provided more diversified financing sources for the entrepreneurship of disadvantaged groups.•We explore the role of digital finance development on the entrepreneurial behavior of Chinese migrants from multiple levels.•Digital finance is conducive to enhancing the entrepreneurial probability and quality of migrants in less developed areas.•The sub-dimensions of breadth of coverage, depth of use and level of digitization can promote the migrants’ entrepreneurship.•Digital finance development promotes both migrants’ necessity-based entrepreneurship and opportunity-based entrepreneurship.•It is more prominent for migrants in rural regions, with lower educational levels or experienced cross-provincial mobility.•It is more significant for migrants who are not party members or parents without good education background and local hukou.•The inclusiveness of digital finance in stimulating entrepreneurship can inspire common prosperity for developing countries.
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•The N, S co-doped carbon dots (N,SCDs) were synthesized from biomass and compound.•The N,SCDs have excellent antioxidant properties.•The N,SCDs are sensitive to detect trace of Cr ...(VI).
In this study, a facile synthesis of N, S-co-doped carbon dots (N, SCDs) from biomass was developed by hydrothermal treatment, using ammonium persulfate as passivator. The N, SCDs have favorable fluorescent properties including high quantum yield (18.7%) and idea fluorescent stability. In addition, the N, SCDs exhibit excellent radical scavenging activities against DPPH radicals, hydroxyl radicals and superoxide anion radicals. It is found that the fluorescence of N, SCDs can be effectively quenched by Cr (VI). The quenching mechanism could be explained due to the antioxidation of N, SCDs. Based on this feature, the selective and sensitive detection of Cr (VI) was performed, showing that a good linear relationship between fluorescence intensity of N, SCDs and Cr (VI) was achieved at the concentration from 1 to 40μM. Furthermore, the detection was applied in real water samples (Taihu and tap waters), resulting in high sensitivity and good recoveries. In a word, this study provides more applications of N, SCDs in antioxidant fields and environmental fields for Cr (VI) detection.
Taking the green credit policy in 2012 as a quasi-natural experiment, this paper applies the methods of propensity score matching and Difference-in-Difference (PSM-DID) to investigate the ...relationship between green credit policy and enterprises’ green technology innovation performance based on Chinese industrial enterprises database and green patent database. The results show that the implementation of “green credit guidelines” policy has significantly improved the green innovation performance of high-polluting and high-energy consuming enterprises, which indicates that the incentive effect of green credit policy on enterprises exceeds the constraint effect and leads to “Porter effect.” Moreover, the green credit policy has significantly increased the number of non-invention patents rather than invention patents. In addition, the green credit policy has a more significant effect on the green innovation performance of high-polluting and energy-intensive enterprises that are state-owned and have weak market power. Mechanism test shows that green credit policy can change the credit financing constraints and R&D investment allocation to affect the green innovation performance of high-polluting and energy-intensive enterprises.
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