Zwitterionic Aqua Palladacycles with Noncovalent Interactions for meta-Selective Suzuki Coupling of 3,4-Dichlorophenol and 3,4-Dichlorobenzyl Alcohol in Water.

The site-selective reaction of substrates with multiple reactive sites has been a focus of the current synthetic chemistry. The use of attractive noncovalent interactions between the catalyst and substrate is emerging as a versatile approach to address site-selectivity challenges. Herein, we designed and synthesized a series of palladacycles, to control meta-selective Suzuki coupling of 3,4-dichlorophenol and 3,4-dichlorobenzyl alcohol. Noncovalent interactions directed zwitterionic aqua palladacycles catalyzed meta-selective Suzuki couplings of 3,4-dichloroarenes bearing hydroxyl in water have been developed. Experiments and density functional theory (DFT) calculations demonstrated that the electrostatic interactions play a critical role in meta-selective coupling of 3,4-dichlorophenol, while meta-selective coupling of 3,4-dichlorobenzyl alcohol arises due to the hydrogen-bonding interactions.

Molecular phylogenetic analysis of the East Asian hemicultrine fishes (Teleostei: Cyprinidae: Xenocypridinae), with suggestions to their generic classification and redescription of the recently described species Hemiculter yungaoi Vasil'eva et al. 2022.

The hemicultrine fishes are a group of small-sized cyprinids, widely distributed but endemic to East Asian rivers and lakes. Till now, the taxonomic boundaries and relationships within this group remain poorly explored. In the present study, we study the phylogeny of this group, providing suggestions for classification of the hemicultrine group. Using two mitochondrial and three nuclear genes, and samples representing all genera, our results showed that the group consists of seven major lineages, of which four (Hemiculterella, Hainania, Pseudolaubuca, and Anabarilius) were monophyletic and three (Hemiculter, Toxabramis, and Pseudohemiculter) were not. Based on the phylogenetic tree, we redefined the genera. We revive the genus Siniichthys, which has three species, Siniichthys bleekeri, Siniichthys lucidus, and S. varpachovskii, that were previously treated as members of the genus Hemiculter but showed distant relationships to the genus Hemiculter in our phylogenetic tree. With the new results, a diagnostic key for clades of the hemicultrine group is provided. Furthermore, we provide more detailed information on diagnostic features of the recently described species Hemiculter yungaoi (Vasil'eva et al., 2022). This work will facilitate future systematic studies, pave the way for evolutionary studies, and provide valuable information for the urgent conservation of hemicultrine fishes.

Effluent quality prediction of the sewage treatment based on a hybrid neural network model: Comparison and application.

The accurate prediction and assessment of effluent quality in wastewater treatment plants (WWTPs) are paramount for the efficacy of sewage treatment processes. Neural network models have exhibited promise in enhancing prediction accuracy by simulating and analyzing diverse influent parameters. In this study, a back propagation neural network hybrid model based on a tent chaotic map and sparrow search algorithm (Tent_BP_SSA) was developed to predict the effluent quality of sewage treatment processes. The prediction performance of the propose hybrid model was compared with traditional neural network models using five performance indicators (MAE, RMSE, SSE, MAPE and R2). Specifically, in comparison with the prior Tent_BP_SSA, Tent_BP_SSA2 demonstrated notable enhancements, with the R2 increasing from 0.9512 to 0.9672, while MAE, RMSE, SSE, and MAPE decreased by 9.62%, 18.84%, 24.80%, and 47.10%, respectively. These indicators collectively affirm that the utilization of higher-order input parameters ensures improved accuracy of the Tent_BP_SSA2 hybrid model in predicting effluent quality. Moreover, the Tent_BP_SSA2 model exhibited robust prediction ability (R2 of 0.9246) when applied to assess the effluent quality of an actual sewage treatment plant. The incorporation of integrated models comprising the sparrow search optimizing algorithm, tent chaotic mapping, and higher-order magnitude decomposition of input parameters has demonstrated the capacity to enhance the accuracy of effluent quality prediction. This study illuminates novel perspectives on the prediction of effluent quality and the assessment of effluent warnings in WWTPs.

Biotic resistance to fish invasions in southern China: Evidence from biomass, habitat, and fertility limitation.

Understanding the mechanisms underlying the invasion success or failure of alien species can help to predict future invasions and cope with the invaders. The biotic resistance hypothesis posits that diverse communities are more resistant to invasion. While many studies have examined this hypothesis, the majority of them have focused on the relationship between alien and native species richness in plant communities, and results have often been inconsistent. In southern China, many rivers have been invaded by alien fish species, providing an opportunity to test the resistance of native fish communities to alien fish invasions. Using survey data for 60,155 freshwater fish collected from five main rivers of southern China for 3 years, we assessed the relationships between native fish richness and the richness and biomass of alien fishes at river and reach spatial scales, respectively. Based on two manipulative experiments, we further examined the impact of native fish richness on habitat selection and the reproductive ability of an exotic model species Coptodon zillii. We found no apparent relationship between alien and native fish richness, whereas the biomass of alien fish significantly decreased with increasing native fish richness. In experiments, C. zillii preferred to invade those habitats that had low native fish richness, given evenly distributed food resources; reproduction of C. zillii was strongly depressed by a native carnivorous fish Channa maculata. Together, our results indicate that native fish diversity can continue to provide biotic resistance to alien fish species in terms of limiting their growth, habitat selection, and reproduction when these aliens have successfully invaded southern China. We thus advocate for fish biodiversity conservation, especially for key species, to mitigate against the population development and ecological impact of alien fish species.

Large-scale DNA barcoding of the subfamily Culterinae (Cypriniformes: Xenocyprididae) in East Asia unveils a geographical scale effect, taxonomic warnings and cryptic diversity.

Geographical scale might be expected to impact significantly the efficiency of DNA barcoding as spatially comprehensive sampling provides opportunities to uncover intricate relationships among closely related species and to detect cryptic diversity for widespread taxa. Here, we present a DNA barcoding study on a Xencyprididae subfamily (Culterinae) involving the production of 998 newly generated DNA barcodes from East Asian drainages (80 localities). Together with 513 barcodes mined from BOLD and GenBank, a reference library consisting of 1511 DNA barcodes (116 localities) for 42 species was assembled, accounting for 66% of known Culterinae species. Intraspecific genetic distances are positively correlated to geographical scale, while a negative correlation is detected between interspecific genetic distances and geographical scale. The present study demonstrates that geographical scale influences the efficiency of DNA barcoding by narrowing the width of the barcoding gap. DNA-based species delimitation analyses delimited 44 molecular operational taxonomic units (MOTUs). Rampant cryptic diversity is detected within eight species with multiple MOTUs, whereas 25 species present mismatch between morphological and molecular delimitations. A total of 18 species are lumped into nine MOTUs due to low interspecific divergence and/or mixed lineages. Several MOTU divergences are hypothesized to relate to known biogeographical barriers and geological events during the Pliocene and Pleistocene. This study provides new insights into the taxonomy and phylogeography of the subfamily Culterinae.

HFIP as Protonation Reagent and Solvent for Regioselective Alkylation of Indoles with All-Carbon Centers.

The regio- and chemoselective construction of indole bearing an all-carbon center at the C3-position, a versatile bioactive building block, by C(sp2)-C(sp3) formation with olefins has been achieved through utilization of hexafluoroisopropanol (HFIP) as the protonation reagent and solvent. The catalytic reactions are operationally simple and green compared with previous reports utilizing elaborated olefins and catalysts. This protocol allows for alkylation of a variety of substituted indoles with diverse of styrene type alkenes in excellent yields and with high selectivity. Application of this protocol to the synthesis of drug was pursued and with an improved yield in contrast to previous art. Catalytic kinetics and deuterium-labeling experiments suggest that the rate-determining step involves the protonation of olefin by HFIP to generate carbocation, followed by electrophilic addition to indole derivative.

Light-Promoted Low-Valent-Tungsten-Catalyzed Ambient Temperature Amination of Boronic Acids with Nitroaromatics.

Triggering C-N bond formation with nitroaromatics and boronic acids at mild conditions is highly desirable, since most prior works were carried out under harsh conditions and sometimes suffered from poor chemo- or regioselectivity. Herein, a low-valent-tungsten-catalyzed reaction that enables the ambient temperature amination of boronic acids with nitroaromatics is disclosed. With readily available W(CO)6 as a precatalyst under external-photosensitizer-free conditions, nitroaromatics smoothly undergo C-N coupling reactions with their boronic acid partners, delivering structurally diverse secondary amines in good yields (>50 examples, yields up to 96%). This methodology is both scalable and highly chemoselective and engages both aliphatic and aromatic boronic acid partners. The catalysis is initiated by the deoxygenation of nitroaromatics by a trans-[W(CO)4(PPh3)2] (trans-W, PPh3 = triphenylphosphine) complex, which forms in situ via ligand replacement.

Tuning the Equatorial Negative Charge in Hexagonal Bipyramidal Dysprosium(III) Single-Ion Magnets to Improve the Magnetic Behavior.

Taking advantage of the pentaethylene glycol (EO5) and deprotonation of EO5, a family of new structurally hexagonal bipyramidal Dy(III) complexes, [Dy(EO5)(2,6-dichloro-4-nitro-PhO)2](2,6-dichloro-4-nitro-PhO) (1), [Dy(EO5-BPh2)(2,6-dichloro-4-nitro-PhO)2] (2), and [Dy(EO5-BPh2)(2,6-dichloro-4-nitro-PhO)Cl] (3), were controbllably synthesized and structurally characterized. Magnetic measurements show that complex 1 is a zero-field SIM and has an observable hysteresis opening up to 4 K. Conversely, only under extra magnetic field is slow magnetic relaxation observed in 2 and 3. This considerable difference in the magnetic behavior is mainly caused by the change of the equatorial negative charge. Detailed ab initio calculations further elucidate that the quantum tunneling is induced by the presence of equatorial negative charge, and the magnetic anisotropy depends on the axial ligands. This work demonstrates that the absence of the equatorial negative charge should also be considered in the rational design of promising single molecular magnets based on the oblate ions.

MIR4435-2HG regulates cancer cell behaviors in oral squamous cell carcinoma cell growth by upregulating TGF-ß1.

MIR4435-2HG has been characterized as an oncogenic lncRNA in several types of cancer, while its role in oral squamous cell carcinoma (OSCC, a major subtype of oral cancer) has not been characterized. We explored the functionality of MIR4435-2HG in OSCC and investigated its interactions with TGF-ß1. Blood samples were extracted from OSCC patients (n = 44) and healthy volunteers (n = 38), RT-qPCR, CCK-8, Transwell assays and western blot were performed in this study. The results showed that levels of MIR4435-2HG and TGF-ß1 in plasma were upregulated in OSCC. Across OSCC plasma samples, TGF-ß1 and MIR4435-2HG were significantly and positively correlated. Overexpression of MIR4435-2HG resulted in upregulated TGF-ß1 expression, while exogenous TGF-ß1 treatment had no effect on the expression of MIR4435-2HG. Overexpression of MIR4435-2HG and exogenous TGF-ß1 treatment led to promoted, while TGF-ß inhibitor led to inhibited migration, proliferation and invasion of cancer cells. Moreover, TGF-ß inhibitor led to reduced effects of overexpressing MIR4435-2HG. Therefore, MIR4435-2HG regulates the behaviors of OSCC cells by promoting the expression of TGF-ß1.

[Research Progress of Micro-arc Oxidation Surface Treatment of Magnesium Alloy].

An oxide ceramic coating can be formed on the surface of magnesium alloy by micro-arc oxidation so that the corrosion resistance of the magnesium alloy can be enhanced.In this paper,ageneral overview of the surface treatment of micro-arc oxidation on the surface of magnesium alloy is presented,the related research on the treatment of several kinds of magnesium alloys is introduced in detail,and a brief introduction of biological activity of magnesium alloy due to micro-arc oxidation is given.Finally,the technical advantages and existing problems are summarized.

A polysaccharide from the alkaline extract of Glycyrrhiza inflata induces apoptosis of human oral cancer SCC-25 cells via mitochondrial pathway.

In the present study, we isolated and characterized a homogenous polysaccharide (GIAP1) from the alkaline extract of the roots of Glycyrrhiza inflata. The anti-tumor activity of GIAP1 toward human oral cancer SCC-25 cells and the underlying mechanisms were also examined in vitro. GIAP1 dose-dependently inhibited the proliferation of SCC-25 cells via inducing apoptosis. Moreover, GIAP1 downregulated Bax/Bcl-2 ratio, disrupted the mitochondrial membrane potential (MMP), and caused the release of cytochrome c to cytosol. Besides, GIAP1 triggered activation of capase-3 and caspase-9, as well as the degradation of poly (ADP-ribose) polymerase (PARP). In addition, the caspase-3 or caspase-9 inhibitor significantly inhibited GIAP1-induced apoptosis in SCC-25 cells. Collectively, we can conclude that the GIAP1 induces apoptosis in SCC-25 cells via a mitochondrial pathway.

A polysaccharide from Glycyrrhiza inflata Licorice inhibits proliferation of human oral cancer cells by inducing apoptosis via mitochondrial pathway.

In the present study, we isolated and characterized a water-soluble polysaccharide (GIP1) from the roots of Glycyrrhiza inflata. The goal of this study was to investigate the anti-tumor effect of GIP1 on the human oral cancer SCC-25 cell line and to explore the possible mechanism. Our experimental result showed that GIP1 (50, 100, and 200 µg/mL) specifically decreased cell viability of SCC-25 cells in a concentration-dependent manner via the induction of apoptosis. Furthermore, Western blot analysis showed that exposure of SCC-25 cells to GIP1 led to down-regulation of anti-apoptotic protein Bcl-2 and up-regulation of pro-apoptotic protein Bax, thus causing a loss of mitochondrial membrane potential and the release of cytochrome c to the cytosol. Moreover, we observed activation of the initiator caspaes-9, and the effector caspases-3, but not caspase-8. Concomitantly, GIP1-induced apoptosis can be blocked by caspase-3- or caspase-9-specific inhibitor, but not caspase-8 inhibitor. As well, the cleaved poly (ADP-ribose) polymerase, as a caspae-3 substrate, occurred in SCC-25 cells following GIP1 treatment at three concentrations. Collectively, our results showed that the GIP1 induced apoptosis in SCC-25 cells involving a caspase-dependent mitochondrial signaling pathway.

Licochalcone A as a potent antitumor agent suppresses growth of human oral cancer SCC-25 cells in vitro via caspase-3 dependent pathways.

The majority of anticancer drugs are of natural origin. However, it is unknown whether licochalcone A is cytotoxic towards oral squamous cell carcinoma (OSCC) cells. The goal of this study was to investigate the cytotoxic effects of licochalcone A on the human OSCC SCC-25 cells and to identify the underlying molecular mechanism. Exposure of SCC-25 cells to licochalcone A dose- and time-dependently decreased cell viability by arresting cell cycle at the S and G2/M phase as well as inducing apoptosis. Furthermore, the proapoptotic activity of licochalcone A was revealed by DNA fragmentation. Concomitantly, we observed activation of the effector caspases-3, induced by activation of the initiator caspases -8 and -9, which subsequent trigger both death receptor pathway and the mitochondrial apoptotic pathway in licochalcone A-mediated SCC-25 cell apoptosis. Besides, treatment with 50 µg/mL of licochalcone A for 36 h led to the cleavage of PARP, an indicator of apoptosis induction. Therefore licochalcone A may be a good candidate for development as a possible chemopreventive agent against OSCC.

Antimetastatic effects of licochalcone A on oral cancer via regulating metastasis-associated proteases.

Licochalcone A, a major phenolic constituent of the licorice species Glycyrrhiza inflata, has been proven to possess various biological benefits including anti-cancer activity. However, the detailed effects and molecular mechanisms of licochalcone A on the invasiveness and metastasis of oral cancer cells have not been fully understood. Thus, SCC-25 oral cancer cells were subjected to a treatment with licochalcone A at indicated concentrations (25, 50, and 100 µg/mL) for 36 h and then analyzed for the effect of licochalcone A on the cell migration and invasion. In vitro assays, including wound healing, cell adhesion, and cell invasion/migration assays, revealed that licochalcone A treatment significantly inhibited the cell migration/invasion capacities of SCC-25 cells. Also, results of zymography and Western blotting showed that activity and protein level of matrix metalloproteinase-2 (MMP-2) was suppressed, but TIMP-2 level was increased, indicating the important role of MMP-2 and TIPM-2 in anti-metastatic regulation of SCC-25 cells. Furthermore, licochalcone A was shown to suppress the nuclear factor-kappa B (NF-κB) signal, as evidenced by the decreased expression of phosphorylated p65 (p-65) protein in licochalcone A-treated SCC-25 cells. Notably, we also found that licochalcone A treatment increased the expression of the epithelial marker E-cadherin and decreased the expression of mesenchymal markers N-cadherin in SCC-25 cells. This is the first report describing the effects and possible mechanisms of licochalcone A on tumor invasion and metastasis of SCC-25 cells. Taken together, our findings support that licochalcone A can be developed to a potent anti-metastatic candidate for oral cancer therapy.

Phylogenetic analysis of Cyprinus acutidorsalis (Wang, 1979) from the Hainan population using complete mitochondrial genome.

Cyprinus acutidorsalis (Wang, 1979) is an endemic fish in China that is sparsely distributed in the Hainan provinces and Guangxi Zhuang Autonomous Region (GZAR). In this study, the complete mitochondrial genome of C. acutidorsalis from the Hainan population from the Wanquan River was sequenced, and its phylogenetic relationship was analyzed. The circular mtDNA was 16,581 bp in length, and the overall base composition was A (32.0%), C (27.5%), T (24.8%), and G (15.70%), with a slight bias toward A + T. The complete mitogenome encoded 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and a control region. Phylogenetic analysis indicated that the most closely related fish to C. acutidorsalis from the Hainan population was C. acutidorsalis from the Guangxi population. These findings offer basic molecular data and a better understanding of the phylogenetic relationships among the Cyprinus species.

Low-valent-tungsten catalysis enables hydroboration of esters and nitriles.

In the research presented herein, low-valent-tungsten-catalyzed hydroboration of esters and nitriles was investigated. Aromatic and aliphatic substrates were smoothly reduced to corresponding alcohol derivatives and N,N-diborylamines in the presence of W(CO)4(NCMe)2. Valuable derivatives were conveniently accessed by introducing a further functionalization process to crude hydroboration mixtures in one pot.

Yolk-shell structured nanoreactor Au@Co3O4/CeO2@mSiO2 with superior peroxidase-like activity as nanozyme for ultra-sensitive colorimetric biosensing.

For yolk-shell structured nanoreactors, multiple active components can be precisely positioned on core and/or shell that can afford more exposed accessible active sites, and the internal voids can guarantee sufficient contact of reactants and catalysts. In this work, a unique yolk-shell structured nanoreactor Au@Co3O4/CeO2@mSiO2 was fabricated and applied as nanozyme for biosensing. The Au@Co3O4/CeO2@mSiO2 exhibited superior peroxidase-like activity with a lower Michaelis constant (Km) and a higher affinity to H2O2. The enhanced peroxidase-like activity was attributed to the unique structure and the synergistic effects between the multiple active components. Colorimetric essays were developed based on Au@Co3O4/CeO2@mSiO2 for the ultra-sensitive sensing of glucose in the range of 3.9 nM-1.03 mM with the limit of detection as low as 3.2 nM. In the detection of glucose-6-phosphate dehydrogenase (G6PD), the cooperation between G6PD and Au@Co3O4/CeO2@mSiO2 triggered the redox cycling between NAD+ and NADH, thereby achieving the amplification of the signal and enhancing the sensitivity of the assay. The assay showed superior performance as compared to other methods with linear response of 5.0 × 10-3-15 mU mL-1 and lower detection limit of 3.6 × 10-3 mU mL-1. The fabricated novel multi-enzyme catalytical cascade reaction system allowed rapid and sensitive biodetection, demonstrating its potential in biosensors and biomedical applications.

Triphenyltin Influenced Carotenoid-Based Coloration in Coral Reef Fish, Amphiprion ocellaris, by Disrupting Carotenoid Metabolism.

Triphenyltin (TPT), a kind of persistent pollutant, is prevalent in the aquatic environment and could pose a threat to coral reef fish. However, little is known about the toxicity of TPT on coral reef fish, especially regarding the representative characteristics of body coloration. Therefore, this study chose the clownfish (Amphiprion ocellaris) in order to investigate the effects of TPT exposure on its carotenoid-based body coloration under the environmentally relevant concentrations (0, 1, 10 and 100 ng/L). After TPT exposure for 60 d, the carotenoid contents were decreased and histological damage in the liver was found, shown as nuclear pyknosis and shift, lipid deposition and fibrotic tissue hyperplasia. Liver transcriptomic analysis showed that TPT exposure interfered with oxidative phosphorylation and fatty acid metabolism pathways, which related to carotenoids uptake and metabolism. Furthermore, TPT exposure led to oxidative damage in the liver, which is responsible for the changes in the antioxidant capacity of enzymes, including GSH, MDA, POD, CAT and T-SOD. TPT exposure also affected the genes (Scarb1, CD36, Stard3 and Stard5) related to carotenoid absorption and transport, as well as the genes (GstP1 and Bco2) related to carotenoid deposition and decomposition. Taken together, our results demonstrate that TPT influenced carotenoid-based coloration in coral reef fish by disrupting carotenoid metabolism, which complements the ecotoxicological effects and toxic mechanisms of TPT and provides data for the body color biology of coral reef fishes.

Light-enhanced transparent hydrogel for uric acid and glucose detection by four different analytical platforms.

The lack of solid-phase media limits the portability of colorimetric sensing platforms. In this study, a series of transparent polyvinyl alcohol (PVA) hydrogels encapsulated antimony tin oxide nanoparticles (ATO NPs) and 3,3',5,5'-tetramethylbenzidine (TMB) were developed as the solid-phase sensing media for glucose and uric acid. Under the conditions of H2O2 and UV light, the hydrogel presented a multicatalytic ability (photo Fenton-like and peroxidase-like activities), which accelerated the oxidation of TMB, turning the hydrogel from colorless to blue and finally enhancing the detection signal. The plasticity of the hydrogel allowed it to be designed into various shapes (membrane, microsphere etc.) to adapt multiple detection platforms (a liquid/solid-phase UV spectrophotometer, a NanoPhotometer, and smartphone spectroscopy). The hydrogel sensing media exhibited excellent tunability and enhanced the photocatalytic ability. The proposed material was successfully applied to detect glucose and uric acids in real samples by four detection platforms to evaluate its practicability.