Design, Synthesis, Insecticidal Activity, and SAR of Aryl Isoxazoline Derivatives Containing Pyrazole-5-carboxamide Motif.

It is important to develop new insecticides with a new mode of action because of increasing pesticide resistance. In this study, a series of novel aryl isoxazoline derivatives containing the pyrazole-5-carboxamide motif were designed and synthesized. Their structures were confirmed by 1H NMR, 13C NMR, and HRMS. Bioassays indicated that the 24 compounds synthesized possessed excellent insecticidal activity against Mythimna separate and no activity against Aphis craccivora and Tetranychus cinnabarinus. Among these aryl isoxazoline derivatives, 3-(5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4,5-dihydrozol-3-yl)-N-(4-fluorophenyl)-1-methyl-1H-pyrazole-5-carboxamide (IA-8) had the best insecticidal activity against M. separate, which is comparable with the positive control fluralaner. The molecular docking results of compound IA-8 and fluralaner with the GABA model demonstrated the same docking mode between compound IA-8 and positive control fluralaner in the active site of GABA. Molecular structure comparisons and ADMET analysis can potentially be used to design more active compounds. The structure-activity relationships are also discussed. This work provided an excellent insecticide for further optimization.

The complete chloroplast genome of Corethrodendron multijugum (Fabaceae: Corethrodendron) and phylogenetic analysis.

Corethrodendron multijugum (Maxim.) (Fabaceae: Corethrodendron), also known as Hedysarum multijugum, is an important medicinal plant and is widely used in traditional Chinese medicine. To better understand the diversity and phylogeny of C. multijugum and other Fabaceae species, we sequenced and annotated the complete chloroplast genome of C. multijugum using the Illumina HiSeq 2500 platform. This complete genome was 122,994 bp long, and encodes a total of 110 genes, including 76 protein-coding genes (PCGs), 30 transfer RNA genes (tRNAs), and four ribosomal RNA unit genes (rRNAs). The C. multijugum plastid with a G + C content of 34.5% presents a negative AT -skew (-0.002) and a positive GC -skew (0.032). Phylogenetic analysis revealed that C. multijugum is more closely related to Hedysarum petrovii. This study provides genetic resource information for the further study of Corethrodendron.

Evaluation of efficacy and safety of PARP inhibitors in breast cancer: A systematic review and meta-analysis.

BACKGROUND: Many breast cancer clinical trials with PARPi have been completed or are currently carried out, either by monotherapy or combined with chemotherapy. We aim to assess the efficacy and safety of PARPi in breast cancer patients as compared to chemotherapy. METHODS: A comprehensive literature search of PubMed, EMBASE, CENTRAL, conference meetings and clinical trial registry was performed. The primary outcomes were progression-free survival (PFS), overall survival (OS), overall response rate (ORR). The secondary outcome was safety profile. The comparative effects were measured using hazard ratio (HR) or relative risk (RR) with 95% confidence interval. Subgroup analyses were conducted based on types of intervention and baseline characteristics of patients. RESULTS: Six RCTs (n = 1953) were included. Two RCTs were recognized as high risk. PARPi was associated with an improved PFS (HR, 0.65; 95% CI, 0.56-0.74), OS (HR, 0.86; 95% CI, 0.73-1.01), and a higher ORR (RR, 1.38; 95% CI, 1.05-1.82). PARPi, however, significantly increased risk of grade 3-4 thrombocytopenia (RR, 1.63; 95% CI, 1.06-2.52). Monotherapy was observed with lower risk of disease progression and higher ORR rate than combination therapy, 0.56 to 0.65 and 2.21 to 1.05, respectively. For patients without prior platinum treatment, PARPi significantly improved PFS (HR, 0.64; 95% CI, 0.52-0.79). CONCLUSIONS: PARPi was observed with a significantly improved efficacy in aspects of PFS and ORR, but also higher risk of grade 3-4 thrombocytopenia as compared to chemotherapy. PARPi was a better choice for patients who had not received previous platinum treatment.

Electron Information in Single- and Dual-Frequency Capacitive Discharges at Atmospheric Pressure.

Determining the electron properties of weakly ionized gases, particularly in a high electron-neutral collisional condition, is a nontrivial task; thus, the mechanisms underlying the electron characteristics and electron heating structure in radio-frequency (rf) collisional discharges remain unclear. Here, we report the electrical characteristics and electron information in single-frequency (4.52 MHz and 13.56 MHz) and dual-frequency (a combination of 4.52 MHz and 13.56 MHz) capacitive discharges within the abnormal α-mode regime at atmospheric pressure. A continuum radiation-based electron diagnostic method is employed to estimate the electron density (ne) and temperature (Te). Our experimental observations reveal that time-averaged ne (7.7-14 × 1011 cm-3) and Te (1.75-2.5 eV) can be independently controlled in dual-frequency discharge, whereas such control is nontrivial in single-frequency discharge, which shows a linear increase in ne and little to no change in Te with increases in the rf input power. Furthermore, the two-dimensional spatiotemporal evolution of neutral bremsstrahlung and associated electron heating structures is demonstrated. These results reveal that a symmetric structure in electron heating becomes asymmetric (via a local suppression of electron temperature) as two-frequency power is simultaneously introduced.

Ultrasensitive photoelectrochemical aptasensor for lead ion detection based on sensitization effect of CdTe QDs on MoS2-CdS:Mn nanocomposites by the formation of G-quadruplex structure.

An ultrasensitive photoelectrochemical (PEC) aptasensor for lead ion (Pb2+) detection was fabricated based on MoS2-CdS:Mn nanocomposites and sensitization effect of CdTe quantum dots (QDs). MoS2-CdS:Mn modified electrode was used as the PEC matrix for the immobilization of probe DNA (pDNA) labeled with CdTe QDs. Target DNA (tDNA) were hybridized with pDNA to made the QDs locate away from the electrode surface by the rod-like double helix. The detection of Pb2+ was based on the conformational change of the pDNA to G-quadruplex structure in the presence of Pb2+, which made the labeled QDs move close to the electrode surface, leading to the generation of sensitization effect and evident increase of the photocurrent intensity. The linear range was 50 fM to 100 nM with a detection limit of 16.7 fM. The recoveries of the determination of Pb2+ in real samples were in the range of 102.5-108.0%. This proposed PEC aptasensor provides a new sensing strategy for various heavy metal ions at ultralow levels.

Visible-light mediated directed perfluoroalkylation of hydrazones.

Perfluoroalkylation of N-alkylhydrazones has been achieved via visible light mediated photoredox reactions between the hydrazone and perfluoroalkyl iodide (RfI). This protocol provides a convenient and efficient access to a series of perfluoroalkylated aromatic aldehyde hydrazones which tolerates a wide range of functional groups on the aromatic ring, and allows the use different types of primary and secondary perfluoroalkyl iodides with up to eight carbon atoms. Furthermore, aliphatic aldehyde hydrazones and N-monosubstituted hydrazones which are unreactive in previously reported hydrazone perfluoroalkylation reactions now take part in the reaction under our reaction conditions to give a satisfactory yield of products. Stern-Volmer quenching studies and spin-trapping experiments indicated that these reactions proceed by free radical addition of the Rf radical to the azomethine atom followed by one electron oxidation of the hydrazyl radical and deprotonation of the diazenium cation.

Highly Sensitive and Selective Photoelectrochemical Biosensor for Hg(2+) Detection Based on Dual Signal Amplification by Exciton Energy Transfer Coupled with Sensitization Effect.

A highly sensitive and selective photoelectrochemical (PEC) biosensor for Hg(2+) detection was developed on the basis of the synergistic effect of exciton energy transfer (EET) between CdS quantum dots (QDs) and Au nanoparticles (NPs) coupled with sensitization of rhodamine 123 (Rh123) for signal amplification. First, the TiO2/CdS hybrid structure obtained by depositing CdS QDs on TiO2 film was employed as a matrix for immobilizing probe DNA (pDNA). Next, Rh123 was introduced into the pDNA terminal, and then Au NP labeled target DNA (Au-tDNA) was hybridized with pDNA to form a rod-like double helix structure. The detection of Hg(2+) was based on a conformational change of the pDNA after incubating with Hg(2+). In the absence of Hg(2+), Rh123 was located away from the electrode surface due to the DNA hybridization, leading to inhibition of the sensitization effect, and meanwhile, the occurrence of EET between CdS QDs and Au NPs resulted in a photocurrent decrease. However, after incubating with Hg(2+), the rod-like double helix was disrupted, and the energy transfer was broken. In this case, the photocurrent recovered, and meanwhile, the folded pDNA made the labeled Rh123 move closer to the electrode surface, leading to the formation of the sensitization structure, which evidently increased the photocurrent intensity. The sensitivity of the biosensor for Hg(2+) detection was greatly enhanced for the dual signal amplification strategy. The linear range was 10 fM to 200 nM, with a detection limit of 3.3 fM. This biosensor provides a promising new platform for detecting various heavy metal ions at ultralow levels.

Electron transfer mediated electrochemical biosensor for microRNAs detection based on metal ion functionalized titanium phosphate nanospheres at attomole level.

MicroRNAs (miRNAs) have emerged as new candidates as diagnostic and prognostic biomarkers for the detection of a wide variety of cancers; thus, sensitive and selective detection of microRNAs is significant for early-phase cancer diagnosis and disease prevention. A novel and simple electrochemical miRNA biosensor was developed using Cd(2+)-modified titanium phosphate nanoparticles as signal unit, two DNA as capture probes, and Ru(NH3)6(3+) as electron transfer mediator. Large quantities of cadmium ions were mounted in titanium phosphate spheres to output the electrochemical signal. Because of the presence of Ru(NH3)6(3+) molecules that interacted with DNA base-pairs as electron wire, the electrochemical signal significantly increased more than 5 times. This approach achieved a wide dynamic linear range from 1.0 aM to 10.0 pM with an ultralow limit detection of 0.76 aM, exerting a substantial enhancement in sensitivity. Moreover, the proposed biosensor was sufficiently selective to discriminate the target miRNAs from homologous miRNAs and could be used for rapid and direct analysis of miRNAs in human serum. Therefore, this strategy provides a new and ultrasensitive platform for miRNA expression profiling in biomedical research and clinical diagnosis.

Bimetallic Pd-Pt supported graphene promoted enzymatic redox cycling for ultrasensitive electrochemical quantification of microRNA from cell lysates.

The expression of microRNAs (miRNAs) is related to some cancer diseases. Recently, miRNAs have emerged as new candidate diagnostic and prognostic biomarkers for detecting a wide variety of cancers. Due to low levels, short sequences and high sequence homology among family members, the quantitative miRNA analysis is still a challenge. A novel electrochemical biosensor with triple signal amplification for the ultrasensitive detection of miRNA was developed based on phosphatase, redox-cycling amplification, a bimetallic Pd-Pt supported graphene functionalized screen-printed gold electrode, and two stem-loop structured DNAs as target capturers. The proposed biosensor is highly sensitive due to the enhanced electrochemical signal of Pd-Pt supported graphene and sufficiently selective to discriminate the target miRNA from homologous miRNAs in the presence of loop-stem structure probes with T4 DNA ligase. Therefore, this strategy provided a new and ultrasensitive platform for amplified detection and subsequent analysis of miRNA in biomedical research and clinical diagnosis.

A competitive electrochemical immunosensor for the detection of human interleukin-6 based on the electrically heated carbon electrode and silver nanoparticles functionalized labels.

A facile one-step electrochemical reduction method was developed to prepare electrochemically reduced graphene oxide (ERGO) and gold-palladium bimetallic nanoparticles (AuPdNPs) as the platform of immunosensor. A novel competitive electrochemical immunosensor was then proposed by combining the ERGO-AuPdNPs platform with silver nanoparticles (AgNPs) functionalized polystyrene bionanolabel for the sensitive detection of human interleukin-6 (IL-6). An electrically heated carbon electrode (HCPE) was introduced in the detection procedure of the immunosensor, and further improved the sensitivity. The immunosensor exhibited a wide linear response to IL-6 ranging from 0.1 to 100000 pg mL(-1) with a detection limit of 0.059 pg mL(-1). The proposed method showed good precision, broad linear range, acceptable stability and high reproducibility, and could be used for the detection of IL-6 in real samples, which possessed promising application in clinical research.

Sonoelectrochemical synthesis of water-soluble CdTe quantum dots.

A facile and fast one-pot method has been developed for the synthesis of CdTe quantum dots (QDs) in aqueous phase by a sonoelectrochemical route without the protection of N2. The morphology, structure and composition of the as-prepared products were investigated by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and energy dispersive X-ray spectrometer (EDS). The influences of current intensity, current pulse width, and reaction temperature on the photoluminescence (PL) and quantum yield (QY) of the products were studied. The experimental results showed that the water-soluble CdTe QDs with high PL qualities can be conveniently synthesized without precursor preparation and N2 protection, and the PL emission wavelength and QY can be effectively controlled by adjusting some parameters. This method can be expected to prepare other QDs as promising building blocks in solar cell, photocatalysis and sensors.

Ultrasensitive multi-analyte electrochemical immunoassay based on GNR-modified heated screen-printed carbon electrodes and PS@PDA-metal labels for rapid detection of MMP-9 and IL-6.

An ultrasensitive electrochemical immunoassay was developed for rapid detection of interleukin-6 (IL-6) and matrix metallopeptidase-9 (MMP-9); the method utilized PS@PDA-metal nanocomposites based on graphene nanoribbon (GNR)-modified heated screen-printed carbon electrode (HSPCE). Because of the good hydrophilicity and low toxicity, GNRs were used to immobilize antibodies (Ab) and amplify the electrochemical signal. PS@PDA-metal was used to label antibodies and generate a strong electrochemical signal in acetic buffer. A sandwich strategy was adopted to achieve simultaneous detection of MMP-9 and IL-6 based on HSPCE without cross-talk between adjacent electrodes in the range of 10(-5) to 10(3) ng mL(-1) with detection limits of 5 fg mL(-1) and 0.1 pg mL(-1) (S/N=3), respectively. The proposed method showed wide detection range, low detection limit, acceptable stability and good reproducibility. Satisfactory results were also obtained in the practical samples, thus showing this is a promising technique for simultaneous clinical detection of biocomponent proteins.

Fabrication of a boron nitride-gold nanocluster composite and its versatile application for immunoassays.

A multifunctional boron nitride-gold nanocluster composite was fabricated using poly-diallyldimethylammonium chloride as a stabilizer and a linker. The as-fabricated composite could be used as a fluorescent or an electrochemical label for immunosensing in the sensitive detection of interleukin-6.

Fabrication of graphene quantum dots and hexagonal boron nitride nanocomposites for fluorescent cell imaging.

Graphene quantum dots (GQDs) with green fluorescence were incorporated onto hexagonal boron nitride sheets (HBN) through electrostatic interaction by using poly(diallyldimethylammonium) (PDDA) as the bridge to fabricate the novel nanocomposites (HBN-GQDs). The HBN-GQDs nanocomposites exhibited strong green fluorescent property, high stability, water solubility, very low cytotoxicity on Hela cells. These properties make the HBN-GQDs nanocomposites as good candidate materials for biological applications. The results for the imaging of live cells indicated that the cell-penetrating HBN-GQDs could be a promising nanoprobe for intracellular imaging and therapeutic applications.

[Maxillary first molar with two palatal canals: a case report].

Maxillary first molar with two palatal canals is rare. Clinicians should be aware of the normal anatomy of root canal system and vigilant about the possible existence of canal variation. A patient with acute episode of chronic pulpitis of 26, as presented by the case report, was examined to have four canals, which were the mesial buccal canal, the distal buccal canal, the mesial palatal canal and the distal palatal canal. When suspecting the existence of canal variation, clinicians should carefully explore the pulpal floor, further by changing the X-ray projection angle to confirm the existence of variation and prevent the missed canals, all of which are necessary for a successful root canal therapy.

The effects of biotic and abiotic factors on the spatial heterogeneity of alpine grassland vegetation at a small scale on the Qinghai-Tibet Plateau (QTP), China.

Understanding the complex effects of biotic and abiotic factors on the composition of vegetation is very important for developing and implementing strategies for promoting sustainable grassland development. The vegetation-disturbance-environment relationship was examined in degraded alpine grasslands in the headwater areas of three rivers on the Qinghai-Tibet Plateau in this study. The investigated hypotheses were that (1) the heterogeneity of the vegetation of the alpine grassland is due to a combination of biotic and abiotic factors and that (2) at a small scale, biotic factors are more important for the distribution of alpine vegetation. On this basis, four transects were set along altitudinal gradients from 3,770 to 3,890 m on a sunny slope, and four parallel transects were set along altitudinal gradients on a shady slope in alpine grasslands in Guoluo Prefecture of Qinghai Province, China. It was found that biological disturbances were the major forces driving the spatial heterogeneity of the alpine grassland vegetation and abiotic factors were of secondary importance. Heavy grazing and intensive rat activity resulted in increases in unpalatable and poisonous weeds and decreased fine forages in the form of sedges, forbs, and grasses in the vegetation composition. Habitat degradation associated with biological disturbances significantly affected the spatial variation of the alpine grassland vegetation, i.e., more pioneer plants of poisonous or unpalatable weed species, such as Ligularia virgaurea and Euphorbia fischeriana, were found in bare patches. Environmental/abiotic factors were less important than biological disturbances in affecting the spatial distribution of the alpine grassland vegetation at a small scale. It was concluded that rat control and light grazing should be applied first in implementing restoration strategies. The primary vegetation in lightly grazed and less rat-damaged sites should be regarded as a reference for devising vegetation restoration measures in alpine pastoral regions.

Seed rain and its relationship with above-ground vegetation of degraded Kobresia meadows.

Seed rain is a crucial element in vegetation regeneration, but has been rarely studied in high altitude regions, particularly degraded Kobresia meadow. Weed infestation is a distinctive feature of pasture degradation in Kobresia meadows on the Tibetan plateau, the ecological mechanism of which is closely related with vegetation's seed rain. In this paper we assess the effect of vegetation degradation on seed rain and consider its implication for restoration of degraded Kobresia meadows in the headwater area of Yellow river, through analysis of seed species composition, number of seeds landing per m(2) of soil surface, and their relationship with above ground vegetation. Vegetation degradation had an impact on the species composition and numbers of seeds in seed rain and their relationship with above-ground vegetation. Within the un-degraded meadow, which provided a closed vegetation cover, 35 % of the seed rain was of sedge and gramineae species. However, within the degraded meadows, as the extent of degradation increased, so the total number of seeds m(-2) increased, with those derived from sedge and gramineae species forming a declining proportion of the total. Degradation of Kobresia meadow on the Tibetan plateau is exacerbated by the seed input of weed species (such as Oxytropis ochrocephala, Carum carvi, Aconitum pendulum, Pedicularis kansuensis in this study). Therefore, a major priority for the restoration of such degraded meadows should be the elimination of these weeds from the above ground vegetation by human intervention.

[Establishment and application of imported falciparum malaria control system in Yangzhou City].

To aim at the characteristics of epidemic situation that the imported falciparum malaria cases increased year by year in Yangzhou City, an imported falciparum malaria control system was established. This control system was based on enhancing the management of returned labor service export persons from falciparum malaria endemic areas, the active medical remind service, the diagnostic capability and health education, and the cooperation of medical personnel and patients, and also avoiding diagnosis delay and misdiagnosis and promoting the treatment in time so as to decrease the serious patients and prevent them from death. After the application of the control system, there were 164 imported falciparum malaria cases from the returned persons of labor service export. The time from the attack of the disease to the diagnosis confirmed decreased from 6.8 days before the application of the system to 2.7 days after the application, and the rate of serious patients was 1.8% and there were no death cases.

Sonoelectrochemical synthesis and assembly of bismuth-antimony alloy: from nanocrystals to nanoflakes.

Bismuth-based nanostructures have attracted growing interest because of their promising thermoelectric properties and applications in optics and electronics. Pulsed sonoelectrochemical technique was selected to fabricate bismuth-antimony (BiSb) flake-like alloy in ethylene glycol aqueous solution. The formation mechanism for the BiSb alloy was discussed. Ultrasonic played an important role in regenerating electrode and promoting the formation of BiSb nanoflakes. Citrate and polyvinylpyrrolidone (PVP) were introduced as mixed controlling agents during the nucleation and growth process.

[Uptake 14CO2 from air and accumulation of 14C in hornwort].

Uptake 14CO2 from air and accumulation of 14C in the hornwort were studied by using the isotope-tracer techniques in order to get a better understanding of the environmental behavior of 14CO2. And the possibility of hornwort used as the indicator plant in the supervisor of 14CO2 air pollution was discussed. The results show that the hornwort could uptake 14CO2 from the air by some way and formed an accumulating trend. The main way was that the hornwort absorbed free 14CO2 and H 14CO3- from the water through photosynthesis. During the introducing 14CO2, the increasing rate of 14C specific activity in dry hornwort and fresh hornwort were between 91.9-95.6 Bq/(g x d) and 6.1-6.3 Bq/(g x d), respectively, which was roughly equal to the increasing rate in the wheat. The results indicate that the hornwort had strong ability of absorbing 14CO2 indirectly through water. The hornwort has an certain concentration of 14CO2. And the concentration factor (CF) values rise with the introduction of 14CO2 and decline slowly after it reached the maximum value. Owing to its accumulation of 14CO2, hornwort can be used as the indicator plant in the supervisor of 14CO2 air pollution.