A new cavefish of Sinocyclocheilus (Teleostei: Cypriniformes: Cyprinidae) from the Nanpanjiang River in Guizhou, China.

A new species, Sinocyclocheilus xingyiensis, is described based on specimens collected from a karst cave in Guizhou Province, China. The authors used an integrated taxonomic approach, including morphological and molecular data, to identify the new species as a member of the Sinocyclocheilu angularis group, and it can be distinguished from all other members of this group by a combination of the following features: two pairs of long barbels and long pectoral fins, 42-46 lateral-line scales, 7 (13-14) on outer (inner) side of the first gill arch and 35 (14-15 + 4 + 16 - 17) vertebrae. Phylogenetic analyses based on the cytochrome b (cyt b) gene fragment suggest that S. xingyiensis is a sister lineage to Sinocyclocheilus flexuosdorsalis. The genetic distance (Kimura 2-parameter) between the S. xingyiensis and S. angularis groups of Sinocyclocheilus species based on cyt b gene fragment ranged from 1.2% to 15.4%.

Highly Efficient and Reusable PI/TiO2 Organic-Inorganic Microfibers for Sustainable Photocatalytic Degradation of Multiple Organic Pollutants under Simulated Sunlight.

Herein, a series of polyimide (PI)/titanium dioxide (TiO2) organic-inorganic flexible composite microfibers with high photocatalytic performance and good reusability were prepared by combining electrospinning technology and a hydrothermal method. Under simulated sunlight, the photocatalytic characteristics of the as-prepared PI nanofibers, TiO2 nanorods, and PI/TiO2 microfibers were evaluated with photocatalytic degradation of Rhodamine B (RhB) solution. Among the tested samples, PI/TiO2-3 mL hydrochloric acid-160 °C-14 h (PI/TiO-3-160-14) (100%) exhibited a superior photocatalytic degradation rate compared to pure PI (84.0%) and TiO2 (62.2%). The enhancement of the photocatalytic performance was attributed to the Z-scheme heterojunction mechanism. When the interface was irradiated by simulated sunlight, the band edge bending, built-in electric field, and Coulomb interaction synergistically facilitated the separation and transport of electron-hole pairs in the heterojunction. This enhanced the oxidation and reduction abilities of the valence and conduction bands of PI/TiO2. These results were adequately verified by X-ray photoelectron spectroscopy (XPS) analyses and radical trapping experiments. Additionally, PI/TiO2 microfibers also demonstrated excellent photocatalytic activity toward methylene blue (MB, 81.4%), methyl orange (MO, 95.9%), and malachite green (KG, 98.9%), underscoring the versatile applicability of PI/TiO2. Further supplementary investigations illustrated that PI/TiO2 microfibers also possess excellent photostability during our extensive recycling photocatalytic experiments.

Comprehensive transcripts analysis based on single-molecule real-time sequencing and Illumina sequencing provides insights into the mining of Toll-like receptor family in Schizothorax lissolabiatus.

Schizothorax lissolabiatus is an economically important cold-water fish species in southwestern China. Because of water pollution and habitat destruction, the number of wild populations has dramatically decreased. In this study, we used PacBio single-molecule real-time (SMRT) sequencing and Illumina sequencing to generate the first full-length transcriptome and transcriptome, respectively. A total of 19 310 polished consensus reads (PC) were obtained, with an average length of 1379 bp and an N50 length of 1485 bp. Meanwhile, 12 253 transcripts were successfully annotated as known homologous genes. The pathway annotation indicated that the enrichment and expression of most genes were mainly related to membrane, signal transduction and binding, and immune response. Furthermore, we identified 16 Toll-like receptors (TLRs) by mining the data from the transcripts. Phylogeny analysis showed that S. lissolabiatus TLR genes (slTLRs) supported the classification of TLRs into six families as in other vertebrates. Selection pressure analyses showed that 16 slTLRs revealed purification selection at the overall evolutionary selection. Further, positive selection signals were still detected in eight slTLRs, and most of the positive selection sites were located in the leucine-rich repeat region (LRR domain) associated with the recognition of pathogenic microorganisms, indicating that the function of these slTLR genes may be affected. Tissue specific expression analysis showed all slTLRs are present in kidney, spleen and liver but the relative expression varied among tissues. In conclusion, this study not only provided a valuable resource of transcripts for further research on S. lissolabiatus, but also contributed to improve the current understanding of the evolutionary history of immune-related genes and the TLR gene family in S. lissolabiatus.

Theoretical study on the superconductivity of graphene-like TMB6 (TM = Cr, Fe and Co) monolayer and its potential anchoring and catalytic properties for lithium-sulfur batteries.

In recent years, two-dimensional materials have aroused enormous interest owing to their superior electrochemical performance, abundant exposed active sites, high specific surfaces and so on. Unlike many stable allotropes, honeycomb hexagonal borophene is kinetically unstable. In this study, we introduce transition metal atoms (Cr, Fe and Co) to stabilize honeycomb hexagonal borophene, forming stable graphene-like TMB6 (TM = Cr, Fe and Co) monolayers. Moreover, we explored the possibility of superconductivity and the anchoring materials of lithium-sulfur batteries using the first-principles density functional theory (DFT) calculation. Our results show that CoB6 exhibited the best superconductivity with a superconducting transition temperature of 33.3 K. Furthermore, CoB6 and FeB6 are promising anchoring materials because of the suppression of lithium polysulfides shuttling in lithium-sulfur batteries because they can accelerate sulfur reduction reaction kinetics.

Effect of Cathodal Transcranial Direct Current Stimulation for Lower Limb Subacute Stroke Rehabilitation.

Methods: A pilot double-blind and randomized clinical trial. Ninety-one subjects with subacute stroke were treated with cathodal/sham stimulation tDCS based on CGR (physiotherapy 40 min/d and occupational therapy 20 min/d) once daily for 20 consecutive working days. Computer-based stratified randomization (1 : 1) was employed by considering age and sex, with concealed assignments in opaque envelopes to ensure no allocation errors after disclosure at the study's end. Patients were evaluated at T0 before treatment, T1 immediately after the posttreatment assessment, and T2 assessment one month after the end of the treatment. The primary outcome index was assessed: lower limb Fugl-Meyer motor score (FMA-LE); secondary endpoints were other gait assessment and relevant stroke scale assessment. Results: Patients in the trial group performed significantly better than the control group in all primary outcome indicators assessed posttreatment T1 and at follow-up T2: FMA-LE outcome indicators between the two groups in T1 (P = 0.032; effect size 1.00, 95% CI: 0.00 to 2.00) and FMA-LE outcome indicators between the two groups in T2 (P = 0.010; effect size 2.00, 95% CI: 1.00 to 3.00). Conclusion: In the current pilot study, ctDCS plus CGR was an effective treatment modality to improve lower limb motor function with subacute stroke. The effectiveness of cathodal tDCS in poststroke lower limb motor dysfunction is inconclusive. Therefore, a large randomized controlled trial is needed to verify its effectiveness.

In Vivo Monitoring of Hydrogen Polysulfide via a NIR-Excitable Reversible Fluorescent Probe Based on Upconversion Luminescence Resonance Energy Transfer.

Hydrogen polysulfide (H2Sn), derived from hydrogen sulfide (H2S), has attracted increasing attention, which is suggested to be the actual signal molecule instead of H2S in physiological and pathological processes. Reversible detection of H2Sn through a NIR-excitable fluorescence probe is an effective means to understand its functions but is quite challenging. Herein, we reported a NIR-excitable ratiometric nanoprobe for the reversible detection of H2Sn based on luminescence resonance energy transfer principle with upconversion nanoparticles as the energy donor and an organic molecule, SiR1, as the energy acceptor and reversible recognition unit of H2Sn. The as-prepared nanoprobe exhibited high selectivity and fast response for the reversible detection of H2Sn, which can monitor the formation and consumption of endogenous H2Sn in living cells. Because of the reduced autofluorescence by NIR excitation, it was successfully applied for tracking the fluctuation of H2Sn concentration of mice in physiological and pathological processes including inflammation and liver injury.

Thermo-Responsive ZnPc-g-TiO2-g-PNIPAM Photocatalysts Sensitized with Phthalocyanines for Water Purification under Visible Light.

A novel thermo-responsive 2,9(10),16(17),23(24)-tetrakis[(3-carboxyacrylamide) phthalocyaninato] zinc (ZnPc)-g-TiO2-g-poly(N-isopropylacrylamide) (PNIPAM) photocatalyst modified with phthalocyanines was prepared. The photocatalyst exhibited thermo-responsive properties due to the introduction of PNIPAM, which performed recovery for reuse above the lower critical solution temperature (LCST, about 26 °C). ZnPc-g-TiO2-g-PNIPAM effectively expanded the light response range to the visible light region and inhibited the recombination of electron-hole pairs, which enhanced the performance of the photocatalyst. As expected, ZnPc-g-TiO2-g-PNIPAM (0.3 g/L) exhibited excellent photocatalytic performance for the removal of Rhodamine B (RhB, 1.0 × 10-5 mol/L) and methylene blue (MB, 1.0 × 10-5 mol/L) under visible light, which reached 97.2% and 88.6% at 20 °C within 40 min, respectively. Furthermore, the influence of temperature upon photocatalytic performance was also investigated. When the temperature increased from 20 °C to 45 °C, the removal of RhB decreased by approximately 53.8%. The stability of the photocatalyst demonstrated that the photocatalytic activity was still above 80% for the removal of RhB after 3 cycles. Above all, this work provided an intelligent thermally responsive photocatalyst based on phthalocyanine for water purification under visible light.

A Versatile Strategy for Constructing Ratiometric Upconversion Luminescent Probe with Sensitized Emission of Energy Acceptor.

When fabricating ratiometric optical probes using lanthanide-doped upconversion nanoparticles (UCNPs), which are promising luminescent materials that have widely been utilized in biosensing and bioimaging as energy donors, it is still a challenge to obtain the emission signal of energy acceptors with reasons unclear so far. Herein, we reveal that the energy-transfer efficiency and brightness of UCNPs as well as the aggregation-caused quenching (ACQ) of energy accepting dyes are the main factors restricting the emission of energy acceptors, and we have circumvented this problem by modulating the structure of UCNPs and the assembly manner of the energy donor-acceptor pair. On this basis, a proof-of-concept ratiometric upconversion nanoprobe was constructed for hydrogen sulfide (H2S) detection with an elaborate dye Fl-1 as an energy acceptor. As the H2S concentration increased, the emission intensity of Fl-1 at 525 nm increased gradually, accompanied by a decrease of upconversion luminescence at 480 nm, thus providing a ratiometric signal of F480/F525 dependent on the H2S concentration. This probe was able to track H2S in living cells and zebrafish and visualize the H2S level of mice in physiological processes.

Aggregation-induced fluorescent response of urea-bearing polyphenyleneethynylenes toward anion sensing.

A π-conjugated urea-bearing phenyleneethynylene polymer (Poly-2) was rationally designed by the Sonogashira coupling condensation reaction and had been demonstrated to have a unique fluorescent quenching effect for the optical detection of all determined anions, especially for CN-. The fluorescent emission of Poly-2 was significantly quenched upon adding CN-, together accompanied with a continuous red shift of the emission peak from 442 to 464 nm with the cyanide concentration increased from 0 to 1.0 mM. On the contrary, its precursor polymer, Poly-1, itself also displayed fluorescent responsibility with all selected anions but had no obvious selectivity and tendency. For instance, the addition of highly basic CN-, N3 -, AcO-, or F- to Poly-1 solution in DMF/H2O (v/v = 1:1) led to the photoluminescence amplification, while the addition of weakly basic anions like Cl-, I-, and Br- showed a fluorescence quenching effect. Both polymers were in a seriously self-aggregated state in solution no matter in the absence or presence of an anion. Interestingly, it was found that Poly-2 exhibited an aggregation-induced emission behavior, while Poly-1 had an aggregation-caused quenching effect, based on the relationship between photoluminescence and polymer aggregation state. The structural characterizations were carried out by NMR spectroscopy and size exclusion chromatography measurements; the photoluminescence properties of Poly-1 and Poly-2 together with anion sensing properties were followed by fluorescence spectroscopy, and the relationship between photoluminescence and aggregation behavior of both polymers in solution was investigated by dynamic light scattering measurements.

One-Pot Facile Synthesis of Noble Metal Nanoparticles Supported on rGO with Enhanced Catalytic Performance for 4-Nitrophenol Reduction.

In this study, reduced graphene oxide (rGO)-supported noble metal (gold, silver, and platinum) nanoparticle catalysts were prepared via the one-pot facile co-reduction technique. Various measurement techniques were used to investigate the structures and properties of the catalysts. The relative intensity ratios of ID/IG in rGO/Au, rGO/Ag, rGO/Pt, and GO were 1.106, 1.078, 1.047, and 0.863, respectively. The results showed the formation of rGO and that noble metal nanoparticles were decorated on rGO. Furthermore, the catalytic activities of the designed nanocomposites were investigated via 4-nitrophenol. The catalysts were used in 4-nitrophenol reduction. The catalytic performance of the catalysts was evaluated using the apparent rate constant k values. The k value of rGO/Au was 0.618 min-1, which was higher than those of rGO/Ag (0.55 min-1) and rGO/Pt (0.038 min-1). The result proved that the rGO/Au catalyst exhibited a higher catalytic performance than the rGO/Ag catalyst and the rGO/Pt catalyst. The results provide a facile method for the synthesis of rGO-supported nanomaterials in catalysis.

Synthesis and characterization of phenylboronic acid-containing polymer for glucose-triggered drug delivery.

Thermo-, pH- and glucose-responsive polymeric nanoparticles are of great interest in developing a self-regulated drug delivery system. The novel core-shell nanoparticles were synthesized by self-assembly of a phenylboronic acid-based block copolymer poly-(N-isopropylacrylamide)-block-poly(3-acrylamidophenylboronic acid) (PNIPAM136-b-PAPBA16) and a fluorescent complex glucosamine-poly(N-isopropylacrylamide)/Eu(III) (GA-PNIPAM)/Eu(III) based on the cross-linking between PBA- and GA-containing blocks in this work. The nanoparticles can be tuned via thermo-induced collapse or glucose-induced swelling at appropriate pH and temperatures; they had an average kinetic radius was about 80nm, and which showed excellent fluorescence. MTT assays revealed the nanocarriers had no significant cytotoxic response of the micelle when it was observed in the cell line over the concentration range from 0.1 to 1000 µg/ml at any exposure times.

Transesterification Reaction and the Repair of Embedded Ribonucleotides in DNA Are Suppressed upon the Assembly of DNA into Nucleosome Core Particles †.

Ribonucleotides can be incorporated into DNA through many different cellular processes, and abundant amounts of ribonucleotides are detected in genomic DNA. Embedded ribonucleotides lead to genomic instability through either spontaneous ribonucleotide cleavage via internal transesterification or by inducing mutagenesis, recombination, and chromosome rearrangements. Ribonucleotides misincorporated in genomic DNA can be removed by the ribonucleotide excision repair (RER) pathway in which RNase HII initiates the repair by cleaving the 5'-phosphate of the ribonucleotide. Herein, based on in vitro reconstituted nucleosome core particles (NCPs) containing a single ribonucleotide at different positions, we studied the kinetics of ribonucleotide cleavage via the internal transesterification reaction and repair of the ribonucleotides by RNase HII in NCPs. Our results show that ribonucleotide cleavage via the internal transesterification in NCPs is suppressed compared to that in free DNA. DNA bending and structural rigidity account for the suppressed ribonucleotide cleavage in NCPs. Ribonucleotide repair by RNase HII in NCPs exhibits a strong correlation between the translational and rotational positions of the ribonucleotides. An embedded ribonucleotide located at the entry site while facing outward in NCP is repaired as efficiently as that in free DNA. However, the repair of those located in the central part of NCPs and facing inward are inhibited by up to 273-fold relative to those in free dsDNA. The difference in repair efficiency appears to arise from their different accessibility to repair enzymes in NCPs. This study reveals that a ribonucleotide misincorporated in DNA assembled into NCPs is protected against cleavage. Hence, the spontaneous cleavage of the misincorporated ribonucleotides under physiological conditions is not an essential threat to the stability of chromatin DNA. Instead, their decreased repair efficiency in NCPs may result in numerous and persistent ribonucleotides in genomic DNA, which could exert other deleterious effects on DNA such as mutagenesis and recombination.

Effect of Pb Filling and Synthesis Pressure Regulation on the Thermoelectric Properties of CoSb3.

To take the advantage of the synergy of atom filling and pressure regulation, atom Pb was assumed to play the role of fillers to occupy the Sb-icosahedron voids. In this paper, skutterudite Pb xCo4Sb11.5Te0.5 materials have been synthesized by high-pressure and high-temperature (HPHT) method with 0.5 h processing time. Although the increase of Pb filling rate increased the electrical resistivity of samples, it reduced the thermal conductivity of samples significantly. When the synthesis pressure increased, the Seebeck coefficients of Pb0.2Co4Sb11.5Te0.5 increased, and the thermal conductivity decreased. The crystal morphology and structure of samples, which can effectively affect the thermoelectric properties of materials, were investigated with XRD, Raman spectra, SEM mapping, and HR-TEM analysis.

Facile synthesis of Fe3O4@Au core-shell nanocomposite as a recyclable magnetic surface enhanced Raman scattering substrate for thiram detection.

The Fe3O4@Au core-shell nanocomposites, as the multifunctional magnetic surface enhanced Raman scattering (SERS) substrates, were fabricated successfully by the seeds growth method based on the Fe3O4-Au core-satellite nanocomposites. The SERS properties of the Fe3O4-Au core-satellite nanocomposites and the Fe3O4@Au core-shell nanocomposites were compared using 4-aminothiophenol (4-ATP) as the probe molecule. It was found that Fe3O4@Au core-shell nanocomposites showed better SERS performance than Fe3O4-Au core-satellite nanocomposites. The Au shell provided an effectively large surface area for forming sufficient plasmonic hot spots and capturing target molecules. The integration of magnetic core and plasmonic Au nanocrystals endowed the Fe3O4@Au core-shell nanocomposites with highly efficient magnetic separation and enrichment ability and abundant interparticle hot spots. The Fe3O4@Au core-shell nanocomposites could be easily recycled because of the intrinsic magnetism of the Fe3O4 cores and had good reproducibility of the SERS signals. For practical application, the Fe3O4@Au core-shell nanocomposites were also used to detect thiram. There was a good linear relationship between the SERS signal intensity and the concentration of thiram from 1 × 10-3 to 1 × 10-8 M and the limit of detection was 7.69 × 10-9 M. Moreover, residual thiram on apple peel was extracted and detected with a recovery rate range of 99.3%. The resulting substrate with high SERS activity, stability and strong magnetic responsivity makes the Fe3O4@Au core-shell nanocomposites a perfect choice for practical SERS detection applications.

Synthesis and characterization of a hyperbranched grafting copolymer PEI-g-PLeu for gene and drug co-delivery.

L-Leucine (Leu) is a hydrophobic natural amino acid and can polymerize into poly-L-Leucine (PLeu) to be an excellent biocompatible material. In this paper, a hyperbranched copolymer polyethyleneimine-g-poly-L-leucine (PEI-g-PLeu) was synthesized by ring-opening polymerization with leucine NCA as monomer and PEI as initiator, which will be used as drug and gene co-delivery system for cancer therapy. To characterize the transfection efficiency in vitro, pGL3 as the reporter gene was loaded in PEI-g-PLeu to form complexes. Doxorubicin (DOX) with cis-aconitic anhydride linker (CAD) and calf thymus DNA (as model DNA) were co-loaded in PEI-g-PLeu to obtain PEI-g-PLeu/DNA/CAD nanoparticles to measure Zeta potentials and particle sizes. Lastly, CAD and modified Bc12-shRNA(as therapeutic gene) were co-loaded in PEI-g-PLeu to get PEI-g-PLeu/CAD/DNA complexes. Our finding revealed when PEI and PLeu with the molar ratio of 1:240, and PEI-g-PLeu and DNA with the mass ratio of 1:5, PEI-g-PLeu/CAD/DNA had negligible cytotoxicity with equivalent gene transfaction efficiency compared with PEI25k. As a result, PEI-g-PLeu/CAD/DNA was a promising drug and gene co-delivery system.

Synthesis of Sialic Acids, Their Derivatives, and Analogs by Using a Whole-Cell Catalyst.

Sialic acids (Sias) are important constituents of cell surface glycans. Ready access to Sias in large quantities would facilitate the development of carbohydrate-based vaccines and small-molecule drugs. We now present a facile method for synthesizing various natural forms and non-natural derivatives or analogs of Sias by using a whole-cell catalyst, which is constructed by adding a plasmid containing necessary enzyme genes into a metabolically engineered strain of Escherichia coli. The flexible substrate tolerance of incorporated enzymes (N-acetylglucosamine 2-epimerase and N-acetylneuraminic acid aldolase) allows the cellular catalyst to convert a wide range of simple and inexpensive sugars into various Sia-related compounds through an easily scalable fermentation process. Further, syntheses using this whole-cell biotransformation in combination with three conventional enzymatic reactions provide a series of complex Sia-containing glycans (sialyloligosaccharides) and their derivatives bearing different substituents. The processes described herein should permit the large-scale and economical production of both Sias and sialyloligosaccharides, and may complement existing chemical and enzymatic strategies.

Planar tetracoordinate carbon species CLi3E with 12-valence-electrons.

We exhibit theoretically a series of 12-valence-electron pentaatomic species CLi3E (E = N, P, As, Sb, Bi) and CLi3E(+) (E = O, S, Se, Te, Po). The analyses of potential energy surfaces indicate that the C2v structures with a planar tetracoordinate carbon are the global minimum in these species except for E = N, P. A localized C[double bond, length as m-dash]E double bond is found in the planar tetracoordinate carbon species. The molecular orbitals and the valence populations reveal that the C[double bond, length as m-dash]E double bonds in CLi3E are different from those in CLi3E(+). The thermodynamic and kinetic calculations show that some of the planar tetracoordinate carbon species are stable and are likely to exist in the gas phase.

Unconventional charge distribution in the planar wheel-type M©B6H6(-/0/+) (M = Mn, Fe and Co): central M with negative charges and peripheral boron ring with positive charges.

Planar wheel-type D6h M©B6H6(-/0/+) (M = Mn, Fe and Co for anion, neutral and cation, respectively.) clusters with a planar hexacoordinate transition-metal at the center of the boron ring were designed and investigated by density functional theory. These planar clusters are chemically stable as a result of their large binding energy, vertical ionization potential, and vertical electron affinity. The detailed natural population and molecular orbital analyses suggest that not only does the M atom donate electrons to the boron ring for participation in the π-delocalized bonding, but also the boron ring donates electrons back to the M atom for the formation of the σ-delocalized bonding, which leads to a strong aromaticity and unconventional charge distribution, i.e., the M atom is negatively charged, while the boron ring is positively charged. This study may open a new area in coordination chemistry for planar hexacoordinate transition metals and we expect further experimental exploration of their synthesis and potential applications.

Synthesis and characterization of ultraviolet light-emitting organic acids.

Three ultraviolet light-emitting organic acids of 3,3'-(4-phenyl-4H-1,2,4-triazole-3,5-diyl)dibenzoic acid (Tz-1), 4,4',4″-(4H-1,2,4-triazole-3,4,5-triyl)tribenzoic acid (Tz-2), and 4,4'-(4-(4'-carboxy-[1,1'-biphenyl]-4-yl)-4H-1,2,4-triazole-3,5-diyl)dibenzoic acid (Tz-3) were successfully synthesized and fully characterized by the (1)H NMR, the IR absorption spectra, and the X-ray single crystal diffraction. It was found that Tz-1, Tz-2, and Tz-3 could give out the ultraviolet photoluminescent spectra centered at 369 nm, 365 nm and 350 nm, respectively. The luminescence quantum yields of Tz-1 and Tz-2 were measured to be 0.20 and 0.14, respectively. Additionally, the density functional theory (DFT) and the time-dependent DFT calculations were also carried out for Tz-1, Tz-2, and Tz-3.

A novel algorithm combining finite state method and genetic algorithm for solving crude oil scheduling problem.

A hybrid optimization algorithm combining finite state method (FSM) and genetic algorithm (GA) is proposed to solve the crude oil scheduling problem. The FSM and GA are combined to take the advantage of each method and compensate deficiencies of individual methods. In the proposed algorithm, the finite state method makes up for the weakness of GA which is poor at local searching ability. The heuristic returned by the FSM can guide the GA algorithm towards good solutions. The idea behind this is that we can generate promising substructure or partial solution by using FSM. Furthermore, the FSM can guarantee that the entire solution space is uniformly covered. Therefore, the combination of the two algorithms has better global performance than the existing GA or FSM which is operated individually. Finally, a real-life crude oil scheduling problem from the literature is used for conducting simulation. The experimental results validate that the proposed method outperforms the state-of-art GA method.