Exposure to mixtures of PM2.5 components and term premature rupture of membranes: a case-crossover study in Shijiazhuang, China.

This study aims to explore the acute effects of short-term exposure to PM2.5 components and their mixture on PROM. Counts of hospital admissions due to PROM were collected at the Fourth Hospital of Shijiazhuang. The associations between the PROM and PM2.5 components was examined using a time-stratified case-crossover approach. The overall effects of components on TPROM were examined using the BKMR. During the study period 30,709 cases of PROMwere identified. The relative risks and the 95% CI of TPROM were 1.013 (1.002, 1.028) and 1.015 (1.003, 1.028) associated with per interquartile range increase in nitrate and ammonium ion on the current day and they were 1.007 (1.001, 1.013) and 1.003 (1.000, 1.005) on the previous day. The results from the BKMR models showed a higher risk of TPROM was associated with exposure to mixtures, in which, nitrate and organic matter were the main contributors to the overall effect.

Preparation of Conotoxin-Encapsulated Chitosan Nanoparticles and Evaluation of Their Skin Permeability.

µ-Conotoxin CnIIIC (conotoxin, CTX)-loaded chitosan nanoparticles (CTX-NPs) were prepared using the ionic cross-linking method. The CTX-NPs were spherical and well with a polydispersity index of 0.292 ± 0.039, drug loading efficiency of 25.9 ± 1.2%, and encapsulation efficiency of 95.6 ± 1.3%. In vitro release studies showed that the release behavior of CTX-NPs in a pH 5.0 acetate buffer followed zero-order kinetics. In vitro transdermal experiments using Franz diffusion cells mounted with mouse abdominal skin demonstrated that the cumulative intradermal deposition amount of CTX per unit area in 8 h (D8) and permeability coefficient (Pf) of CTX loaded on CTX-NPs were 2.30- and 7.71-times that of the CTX solution. In vivo transdermal experiments in mice showed that the amount of CTX deposited in the skin after 8 h of CTX saline administration was significantly lower than that of CTX deposited in the skin after administration of CTX-NPs. In vitro fluorescence labeling transdermal studies through Franz diffusion cells mounted with mouse abdominal skin indicated that CTX-NPs aggregated at hair follicles. Skin irritation tests in mice indicated that the irritation due to CTX-NPs was negligible. The cytotoxicity experiment showed that the viability of Balb/c 3T3 cells with CTX-NPs containing 230 µg/mL (0.08 µM) CTX was greater than 75%. CTX-NPs increase intradermal deposition of CTX by accumulating in hair follicles, which has positive implications for transdermal penetration of CTX.

Orthodontic care in orthodontic patients during the COVID-2019 pandemic: emergency, emergency response and orthodontic treatment preference.

BACKGROUND: The objective of this study was to investigate the characteristics of emergencies and the requirement for emergency treatment after the suspension of orthodontic appointments. The attitude towards orthodontic treatment preference was evaluated as well, including receiving orthodontic treatment and the preference for orthodontic appliances. SUBJECTS AND METHODS: An electronic questionnaire was distributed to the patients, including 4 sections: Section 1 - demographic and basic information; Section 2 - the characteristics of emergencies and emergency treatment requirements; Section 3 - the NRS-11 for pain and Manchester Orofacial Pain Disability Scale used to evaluate the intensity of orofacial pain and disability; and Section 4 - attitudes towards receiving orthodontic treatment and appliance preference. Descriptive statistics, Pearson's chi-square test, Wilcoxon's rank-sum test and stepwise generalized linear model (GLM) were performed with significance set at P < 0.05. RESULT: Most participants' (91.61%) follow-up appointments were suspended. The emergency rate and emergency treatment requirements were not different between the fixed appliance (FA) and clear aligner (CA) groups. Patients who reported emergencies (P < 0.01) in the FA group (P < 0.05) and some emergencies in the FA (P < 0.05) suffered worse pain and disability. More FA participants preferred alternative appliances (P < 0.05) due to pain and disability (P < 0.05). CONCLUSION: FA patients' emergencies caused worse pain and disability when orthodontic appointments were suspended. Pain and disability were not the causes of emergency treatment requirements. The CA group seemed to show a tendency towards orthodontic appliance preference, which was an ideal modality to weather the epidemic, combined with telemedicine.

Paternal reprogramming-escape histone H3K4me3 marks located within promoters of RNA splicing genes.

MOTIVATION: Exposure of mouse embryos to atrazine decreased histone tri-methylation at lysine 4 (H3K4me3) and increased expression of alternatively spliced RNA in the third generation. Specificity protein (SP) family motifs were enriched in the promoters of genes encoding differentially expressed alternative transcripts. RESULTS: H3K4me3 chromatin immunoprecipitation sequencing (ChIP-seq) of mouse sperm, preimplantation embryo development and male gonad primordial germ cells (PGCs) were analysed to identify the paternal reprogramming-escape H3K4me3 regions (RERs). In total, 251 RERs selected harbour H3K4me3 marks in sperm, with signals occurring in the paternal genome during early development and in male gonad PGCs, and 179 genes had RERs within 1 kb of transcription start sites (TSSs). These genes were significantly enriched in the gene ontology term 'RNA splicing', and SP1/SP2/SP3 motifs were enriched in RER-associated H3K4me3 peaks. Overall, the H3K4me3 marks within TSSs of RNA splicing genes survived two rounds of the epigenetic reprogramming process. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Copper-Catalyzed Dynamic Kinetic C-P Cross-Coupling/Cyclization for the Concise Asymmetric Synthesis of Six-, Seven- and Eight-Membered P-Stereogenic Phosphorus Heterocycles.

A copper-catalyzed asymmetric aryl C-P cross-coupling/cyclization reaction was successfully developed via dynamic kinetic asymmetric transformation (DYKAT) under mild conditions. This study provides a general and simple method for the catalytic enantioselective synthesis of stable six-, seven- and eight-membered P-stereogenic phosphorus heterocycles with excellent enantioselectivities and moderate to high yields. One-pot gram-scale asymmetric synthesis of the P-stereogenic P-heterocycle from commercially available materials was also successfully accomplished with excellent enantioselectivity and high yield.

High-Performance Perovskite Composite Electrocatalysts Enabled by Controllable Interface Engineering.

Single-phase perovskite oxides that contain nonprecious metals have long been pursued as candidates for catalyzing the oxygen evolution reaction, but their catalytic activity cannot meet the requirements for practical electrochemical energy conversion technologies. Here a cation deficiency-promoted phase separation strategy to design perovskite-based composites with significantly enhanced water oxidation kinetics compared to single-phase counterparts is reported. These composites, self-assembled from perovskite precursors, comprise strongly interacting perovskite and related phases, whose structure, composition, and concentration can be accurately controlled by tailoring the stoichiometry of the precursors. The composite catalyst with optimized phase composition and concentration outperforms known perovskite oxide systems and state-of-the-art catalysts by 1-3 orders of magnitude. It is further demonstrated that the strong interfacial interaction of the composite catalysts plays a key role in promoting oxygen ionic transport to boost the lattice-oxygen participated water oxidation. These results suggest a simple and viable approach to developing high-performance, perovskite-based composite catalysts for electrochemical energy conversion.

Determination of PEGylation homogeneity of polyethylene glycol-modified canine uricase.

Polyethylene glycol-modified canine uricase (PEG-UHC) was prepared by modifying the ε-amino group of lysine residues on the canine uricase (UHC) protein to near-saturation with 5 kDa monomethoxyl-polyethylene glycol succinimide (mPEG-SPA-5k). In order to accurately determine the PEGylation uniformity of PEG-UHC, CZE, 3-8% gradient gel SDS-PAGE, and imaging CIEF (iCIEF) analyses were compared. CZE could not effectively separate PEG-UHC proteins with different degrees of modification, 3-8% gradient gel SDS-PAGE could separate PEG-UHC into seven gel bands; however, most of the gel bands were smeared or blurred, and the separation of PEG-UHC samples by iCIEF was significantly better than that by 3-8% gradient gel SDS-PAGE. Under denatured conditions, iCIEF separated 12 pI peaks, and could also accurately quantify the relative monomer PEG-UHC content. More than 85% of the total monomeric PEG-UHC was conjugated with 7-12 PEG molecules; of this 85%, approximately 40% was conjugated with 9-10 PEG molecules. These results demonstrated that iCIEF exhibits good potential for determining the PEGylation homogeneity of PEGylated protein drugs.

Construction of a Carbon Dots/Cobalt Oxyhydroxide Nanoflakes Biosensing Platform for Detection of Acid Phosphatase.

Because abnormal acid phosphatase (ACP) can disrupt the normal physiological processes, determination of ACP level is extremely important for early diagnosis, treatment, and prognostic evaluation of diseases. Herein, a fluorescence platform for monitoring ACP level was established based on the assembly of red-emitting carbon dots (RCDs) on cobalt oxyhydroxide (CoOOH) nanoflakes. RCDs displayed excellent water solubility, pH stability, salt resistance, and photobleaching resistance. Interestingly, the fluorescence of the RCDs assembled on the surface of the CoOOH nanoflakes could be quenched due to the energy transfer caused by the nanoflakes. However, the ascorbic acid (AA) produced by the hydrolysis of ascorbic acid-2-phosphate trisodium salt (AAP) catalyzed by ACP could quickly and effectively reduce CoOOH nanoflakes, leading to the fluorescence recovery of the RCDs. Therefore, an "off-on" biosensor platform for rapid, sensitive, and selective detection of ACP was constructed with a limit of detection of 0.25 mU/L. With the assistance of the biosensor, the level of ACP in human serum samples was evaluated, and the spike recovery values ranged from 94.0% to 104.5%.

First Report of Ergot (Claviceps purpurea) on Drunken Horse Grass (Achnatherum inebrians) in China.

Drunken horse grass (Achnatherum inebrians) belongs to the family Poaceae: it is mainly distributed in the natural grasslands of northern and northwestern in China. Ergot is a disease that can not only affect the growth of the grass, but also cause livestock poisoning (Coufal-Majewski et al. 2016). In September 2018, ergot was observed in a large area (about 15 ha) in Xinghai county, Qinghai province, China (35° 47' N, 99° 53' E, Altitude 3559 m). Around 65% of the plants of Achnatherum inebrians were affected. Symptoms initially showed drop-like honeydew on the ears of drunken horse grass, and later brown to dark brown sclerotia were observed. These were straight to slightly curved, measured 6.7 to 13.5 × 1.5 to 2.1 mm, which was approximately 1 to 4 times the size of healthy seeds. Sixteen spikes with typical symptoms were collected from eight different fields. Sclerotia were disinfested by immersion in 75% ethanol for 30 s and 1% NaClO for 90 s, rinsed three times in sterilized water, plated on potato dextrose agar (PDA) medium, incubated at 24°C in the dark and isolates purified by culturing from single spores. Finally, 16 single-spore cultures with similar phenotypes were obtained from these sclerotia. Colonies produced on PDA for 15 days at 24 ℃ were grayish white with fluffy aerial mycelium, about 60 mm in diameter. Conidia were hyaline, ovoid to cylindrical, 5.42 to 7.69 × 2.85 to 3.75 µm (avg. 5.67 × 3.2; n = 50). These morphological characteristics were consistent with the descriptions of Claviceps species in general (PíchovÁ et al. 2018). To further identify the Claviceps spp., isolate NSZJ (=MHLZU-AI20201012) was selected as a representative for molecular characterization. Two nuclear protein-coding genes TUB2 and MCM7 were amplified by T2/T12 (O'Donnell and Cigelnik 1997) and CARCA-F/M456-5R (Rehner and Buckley 2005), respectively, and sequenced. Sequences were deposited in GenBank (accession nos. MW115640 for TUB2 and MW115641 for MCM7). A BLAST analysis of these two segments showed >99% identity with those sequences of isolate W3 of C. purpurea (Pazoutová et al. 2014). To confirm the pathogenicity on drunken horse grass, 20 healthy plants (2-year-old) grown in an experimental field at the College of Pasture Agriculture Science and Technology, Yuzhong Campus of Lanzhou University in China (104° 39' E, 35° 89' N, altitude1653m) were spray-inoculated with conidial suspension (1 × 106 conidia/ml) during the flowering period. Another 20 plants in the field were sprayed with sterilized distilled water as controls. All plants were individually covered with transparent polyethylene bags for 24 h to maintain high relative humidity. After 7 to 10 days, small yellowish-white drops of honeydew were observed in some florets. At 22 days post inoculation, all the inoculated panicles developed three to six sclerotia per head, ranging in size from 6.7 to 13.5 mm, while control plants remained healthy. The same pathogen was consistently re-isolated from inoculated spikes and confirmed by morphological and molecular characterization as described above. Claviceps purpurea was reported to be associated with ergot in A. lemmonii in Idaho and A. robustum in Montana (Alderman et al. 2004). To our knowledge, this is the first report of C. purpurea causing ergot in A. inebrians in China.

A phenylenediamine-based carbon dot-modified silica stationary phase for hydrophilic interaction chromatography.

Red emitting carbon dots derived from p-phenylenediamine (PPDCDs) were successfully prepared and grafted onto the surface of silica spheres, which served as a new stationary phase (Sil-PPDCDs) for liquid chromatography with excellent hydrophilic selectivity. Various hydrophilic analytes including nucleosides and bases, amino acids, saccharides and ginsenosides can be well separated on this stationary phase. Compared with the precursor-modified silica, i.e. p-phenylenediamine functionalized silica stationary phase (Sil-PPD), Sil-PPDCDs possessed enhanced selectivity for the separation of tested polar compounds. Moreover, compared with two commercially available hydrophilic columns, the selective behavior of the stationary phase was also considerable. The successful application of the Sil-PPDCDs stationary phase again indicated the great potential of carbon dots as a new modifier of the stationary phase in high performance liquid chromatography, and this kind of new stationary phase is very promising to be used for the separation of hydrophilic compounds in biochemical and pharmaceutical analysis.

Discriminative Detection of Glutathione in Cell Lysates Based on Oxidase-Like Activity of Magnetic Nanoporous Graphene.

As the most abundant intracellular biothiol, glutathione (GSH) plays a central role in many cellular functions and has been proved to be associated with numerous clinical diseases. Nevertheless, it is still a challenge to detect GSH over other mercaptoamino acids owing to their similar structures and activities. In this paper, magnetic nanoporous graphene (MNPG) nanocomposites were prepared for the first time through partial combustion of graphene oxide (GO) and ferric chloride. Due to the combination of porous graphene and magnetic nanoparticles, the MNPG nanocomposites exhibited large specific surface area, fast mass, and electron transport kinetics, resulting in remarkable oxidase mimic activity and easy separation. On the basis of the inhibition effect of GSH on the MNPG-catalyzed oxidation of thiamine, a novel and simple method for fluorescence determination of GSH was established. The sensor displayed a good linear response in the range of 0.2-20 µM toward GSH with a limit of detection of 0.05 µM. High sensitivity and selectivity facilitated its practical application for discriminative detection of GSH levels in PC12 cell lysates. The presented assay will be a simple and powerful tool to monitor intracellular GSH levels for biomedical diagnosis. Furthermore, the MNPG nanocomposites will provide insights to construct nanoporous graphene-based hybrids and push forward the advancement of porous graphene for wide applications.

Fast Charge Diffusion in MAPb(I1- xBr x)3 Films for High-Efficiency Solar Cells Revealed by Ultrafast Time-Resolved Reflectivity.

Organometallic halide perovskite solar cells such as MAPbI3 have shown great promise as a low-cost, high-efficiency photovoltaic candidate. Recent studies demonstrated that by substituting an appropriate amount I ions of MAPbI3 with Br ions, the device performance parameters, such as moisture stability or power conversion efficiency, can be further optimized. In this study, using time-resolved optical reflectivity to track the carrier dynamics in MAPb(I1- xBr x)3 films with different Br contents, we found that photocarriers in MAPb(I1- xBr x)3 films with x = 0.01 and 0.02 diffuse much faster than those in films with other Br contents. We suggest that the faster charge carrier diffusion benefits from larger crystal grain size. As a result, this suppresses electron and hole recombination and increases the carrier extraction efficiency, in agreement with the higher power conversion efficiency reported previously.

Fluorometric dopamine assay based on an energy transfer system composed of aptamer-functionalized MoS2 quantum dots and MoS2 nanosheets.

The authors describe a fluorometric strategy for the determination of dopamine (DA). It is based on the use of aptamer-functionalized MoS2 quantum dots (QDs) and MoS2 nanosheets (NSs). The QDs and NSs were extensively characterized with regard to their physical and chemical properties using methods such as TEM, XRD, FT-IR, EDX and molecular spectroscopies. The aptamer against dopamine was labeled with QDs acting as the energy donor in an energy transfer system, while the NSs serve as the energy acceptor. Under the optimal conditions, the fluorescence (FL) intensity (best measured at excitation/emission peaks of 315/412 nm) increases with increasing DA concentration in the range from 0.1 nM to 1000 nM, with a lower detection limit of 45 pM. The method was successfully applied to the determination of DA in complex matrices. In our perception, the method has a wide scope in that it may be extended to other biomolecules for which respective aptamer are available. The QDs show excellent optical properties, good stability, low cytotoxicity, and may also be applied to fluorometric imaging of live cells. Graphical abstract A "turn-on" fluorometric aptasensor for the determination of dopamine (DA) was established based on aptamer-functionalized molybdenum disulfide quantum dots (MoS2 QDs) and MoS2 nanosheets. This assay exhibits high selectivity and sensitivity with a detection limit as low as 45 pM.

The ethanol extract of honeysuckle stem modulates the innate immunity of Chinese mitten crab Eriocheir sinensis against Aeromonas hydrophila.

Honeysuckle stem had been used as feed additives to modulate immunity in breeding industry, which was limited in the aquaculture field. In this study, the immunomodulation of honeysuckle stem ethanol extract (designed as HSE) on Chinese mitten crab Eriocheir sinensis was detected. The crabs fed with HSE diets for 30 days had higher level of the total haemocyte count (HTC), lysozyme activity and PO activity (P < 0.05), and had no obvious affect on the phagocytic activity, NO and TNF-α level. When challenged with Aeromonas hydrophila (1.0 × 107 colony-forming units), HSE exhibited weak antibacterial activity against A. hydrophila and increased survival rate of crabs. The decreasing of THC and the increasing of TNF-α concentration, EsCaspase and EsLITAF mRNA expression level were all inhibited significantly by HSE treatment (P < 0.05), when the crabs were challenged by A. hydrophila. Moreover, the following immune parameters of crabs were enhanced by HSE treatment after A. hydrophila infection, including the rising of phagocytosis index and phagocytic rate of haemocyte, the rising of lysozyme, PO, NOS activities and nitric oxide concentration (P < 0.05). Therefore, it was concluded that HSE had great potential to develop into feed additive of crabs, which could enhance the innate immunity of Chinese mitten crabs E. sinensis effectively after A. hydrophila infection.

Preparation and characterization of carbon dot-decorated silica stationary phase in deep eutectic solvents for hydrophilic interaction chromatography.

In this paper, N-doped carbon dots (NCDs) were successfully decorated on the spherical porous silica surface in deep eutectic solvents (DESs) as a novel class of green solvents. The appropriate density and hydrophility of DESs guaranteed the fine dispersibility of silica particles and NCDs, resulting in a homogeneous and thin layer of NCDs immobilization. As compared with traditional organic solvents (DMF and THF), higher surface coverage was obtained in the medium of DES, proving its feasibility as a new kind of alternative solvent for hydrophilic nanomaterial-based surface modification of silica spheres. The resulting NCDs-decorated silica particles (Sil-NCDs) were characterized in detail and packed into chromatographic columns to study their initial feasibility as adsorbent material for liquid chromatography. The resultant packing materials demonstrate a selective behavior for polar compounds in hydrophilic interaction liquid chromatography (HILIC) mode. This work gives a typical example of using carbon dots as stationary phase component, and such material is hopeful to be used in other research fields such as solid absorbents, recycling catalysts, and solid-state electrochemistry etc. Graphical Abstract N-doped carbon dots (NCDs) were successfully coupled on the surface of porous silica spheres in a green strategy using deep eutectic solvents (DES) as media for HILIC.

One-step synthesis of nitrogen, boron co-doped fluorescent carbon nanoparticles for glucose detection.

Heteroatom-doped carbon nanoparticles (CNPs) have attracted considerable attention due to an effective improvement in their intrinsic properties. Here, a facile and simple synthesis of nitrogen, boron co-doped carbon nanoparticles (NB-CNPs) from a sole precursor, 3-aminophenylboronic acid, was performed via a one-step solid-phase approach. Because of the presence of boronic acid, NB-CNPs can be used directly as a fluorescent probe for glucose. Based on a boronic acid-triggered specific reaction, we developed a simple NB-CNP probe without surface modification for the detection of glucose. When glucose was introduced, the fluorescence of NB-CNPs was suppressed through a surface-quenching states mechanism. Obvious fluorescence quenching allowed the highly sensitive determination of glucose with a limit of detection of 1.8 µM. Moreover, the proposed method has been successfully used to detect glucose in urine from people with diabetes, suggesting potential application in sensing glucose.

Bovine Serum Albumin Adsorption in Mesoporous Titanium Dioxide: Pore Size and Pore Chemistry Effect.

Understanding the mechanism of protein adsorption and designing materials with high sensitivity, high specificity and fast response are critical to develop the next-generation biosensing and diagnostic platforms. Mesoporous materials with high surface area, tunable pores, and good thermal/hydrostatic stabilities are promising candidates in this field. Because of the excellent biocompatibility, titanium dioxide has received an increasing interest in the past decade for biomedical applications. In this work, we synthesized mesoporous titanium dioxide with controlled pore sizes (7.2-28.0 nm) and explored their application for bovine serum albumin (BSA) adsorption. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption/desorption experiments were performed to characterize the mesoporous TiO2 samples before and after BSA adsorption. Isothermal microcalorimetry was applied to measure both the adsorption heat and conformation rearrangement heat of BSA in those mesopores. We also carried out thermogravimetry measurements to qualitatively estimate the concentration of hydroxyl groups, which plays an important role in stabilizing BSA in-pore adsorption. The adsorption stability was also examined by leaching experiments. The results showed that TiO2 mesopores can host BSA adsorption when their diameters are larger than the hydrodynamic size of BSA (∼9.5 nm). In larger mesopores studied, two BSA molecules were adsorbed in the same pores. In contrast to the general understanding that large mesopores demonstrate poor stabilities for protein adsorptions, the synthesized mesoporous TiO2 samples demonstrated good leaching stabilities for BSA adsorption. This is probably due to the combination of the mesoporous confinement and the in-pore hydroxyl groups.

Generation of low repetition rate subnanosecond pulse in an optimal doubly QML Nd:Lu0.15Y0.85VO4 laser with EO and Cr4⁺:YAG.

Employing different output couplers and Cr4+:YAG saturable absorbers with different initial transmittances in a Q-switched mode-locked (QML) Nd:Lu0.15Y0.85VO4 laser, the symmetry of the Q-switched envelope was optimized and the envelope duration was shortened. By applying the above mentioned optimization into an EO/Cr4+:YAG dual-loss-modulated QML Nd:Lu0.15Y0.85VO4 laser, the Q-switched envelope can be further compressed until only containing one mode-locking pulse. Mode-locking pulse energy and peak power up to 1.15 mJ and 3.15 MW, respectively, were achieved. The rate equation theory was utilized to analyze the experimental results, and the theoretical simulation was basically in accordance with the experimental data.

Fluorescence resonance energy transfer-based ratiometric fluorescent assay for highly sensitive and selective determination of sulfide anions.

A novel and effective ratiometric fluorescence strategy was developed for rapidly, sensitively and selectively probing sulfide anions (S(2-)). A dual-emission nanosensor was prepared by covalently attaching fluorescent carbon nanoparticles (CNPs) to gold nanoclusters (Au NCs), triggering the sensing mechanism of fluorescence resonance energy transfer (FRET) from CNPs (donor) to Au NCs (acceptor). Once S(2-) was added, considerable fluorescence recovery of CNPs and quenching of Au NCs were observed due to the inhibition of FRET progress via the formation of Au2S. The ratiometric probe showed good, specific S(2-) sensing behavior and high sensitivity with a detection limit of 18 nM. Significantly, the assay was successfully employed to determine the S(2-) content in biological and water samples, presenting immense promise in the biological and environmental fields.