Calcium titanate (CaTiO
3
) nanoparticles with different average sizes were prepared by a polyacrylamide gel route, where the particle size was tailored by using different chelating agents. Scanning ...electron microscope observation shows that the samples prepared by using the chelating agents EDTA, acetic acid, tartaric acid, and citric acid have an average particle size of 25, 33, 36, and 55 nm, respectively. All the particles are regularly shaped like spheres. The bandgap energy of the four samples is measured to be 3.66–3.59 eV by ultraviolet (UV)–visible diffuse reflectance spectroscopy. The photocatalytic activity of the prepared CaTiO
3
samples was evaluated by the degradation of methyl orange under 254 nm UV irradiation, revealing that they exhibit a good photocatalytic activity. Hydroxyl radicals are revealed, by the photoluminescence technique using terephthalic acid as a probe molecule, to be produced on the irradiated CaTiO
3
nanoparticles and suggested to be the primary active species toward the dye degradation.
Context.
No robust detection of prompt electromagnetic counterparts to fast radio bursts (FRBs) has yet been obtained, in spite of several multi-wavelength searches having been carried out so far. ...Specifically, X/
γ
-rays counterparts are predicted by some models.
Aims.
We aim to search for prompt
γ
-ray counterparts in the Insight-Hard X-ray Modulation Telescope (Insight-HXMT) data, taking advantage of the unique combination of the large effective area in the keV–MeV energy range, and of sub-ms time resolution.
Methods.
We selected 39 FRBs that were promptly visible from the High-Energy (HE) instrument aboard Insight-HXMT. After calculating the expected arrival times at the location of the spacecraft, we searched for a significant excess in both individual and cumulative time profiles over a wide range of time resolutions, from several seconds down to sub-ms scales. Using the dispersion measures in excess of the Galactic terms, we estimated the upper limits on the redshifts.
Results.
No convincing signal was found, and for each FRB we constrained the
γ
-ray isotropic-equivalent luminosity and the released energy as a function of emission timescale. For the nearest FRB source, the periodic repeater FRB 180916.J0158+65, we find
L
γ
, iso
< 5.5 × 10
47
erg s
−1
over 1 s, whereas
L
γ
, iso
< 10
49
− 10
51
erg s
−1
for the bulk of FRBs. The same values scale up by a factor of ∼100 for a ms-long emission.
Conclusions.
Even on a timescale comparable with that of the radio pulse itself, no keV–MeV emission is observed. A systematic association with either long or short GRBs is ruled out with high confidence, except for sub-luminous events, as is the case for the core-collapse of massive stars (long) or binary neutron star mergers (short) viewed off axis. Only giant flares from extragalactic magnetars at least ten times more energetic than Galactic siblings are ruled out for the nearest FRB.
Fourteen isolates of Toxoplamsa gondii were isolated from cats from 4 different geographic provinces (Anhui, Hubei, Shanxi and Guangdong) in China and their genetic diversity with 8 nuclear loci ...SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico, was analysed by restriction fragment length polymorphisms (RFLPs). Two genotypes from these 14 isolates were identified but none of them belongs to the typical genetic types (types I, II and III). It is unexpected that such high similarity was observed in these 14 isolates although their original regions are significantly distant. Our results strongly indicate that the three traditional clonal lineages of types I, II and III of this parasite may not be preponderant in China. In addition, our results show that the genotypes of T. gondii in China may be highly clonal with atypical genotypes and higher virulence.
An anaerobic kraft lignin (KL)‐degrading bacterial strain was isolated from sludge of a pulp and paper mill. It was characterized as Acetoanaerobium sp. WJDL‐Y2 by 16S rRNA gene sequencing. The ...maximum KL degradation capability of strain Y2 was determined to be 24·9% on a COD basis under an optimal condition with temperature of 31·5°C, initial pH of 6·8 and KL to nitrogen (as NH₄Cl) ratio of 6·5 by mass. Growth kinetic studies showed that the KL tolerance of strain Y2 was relatively high (Kᵢ = 8120·45 mg l⁻¹). Analysing KL degradation products by GC‐MS revealed the formation of low‐molecular‐weight aromatic compounds (LMWACs), including benzene‐propanoic acid, syringic acid and ferulic acid. This indicates that strain Y2 can oxidize lignin structure's p‐hydroxyphenyl (H) units, guaiacyl (G) units and syringyl (S). In addition, the inoculated sample also contained low‐molecular acid compounds, such as hexanoic acid, adipic acid and 2‐hydroxybutyric acid, further validating strain Y2's ability to degrade KL. SIGNIFICANCE AND IMPACT OF THE STUDY: Kraft lignin containing effluents discharged from pulp and paper industries causes serious environmental pollution in developing countries. Due to the immense environmental adaptability and biochemical versatility, bacterial ligninolytic potential deserve to be studied for application in effluent treatment of pulp and paper industry. In this study, an anaerobic lignin‐degrading bacterium, Acetoanaerobium sp. WJDL‐Y2 (accession no. KF176997),was isolated from the sludge of a pulp and paper mill. Strain Y2 can play an important role in treating pulp and paper wastewater, as well as breaking down materials for biofuel and chemical production.
Branched-chain volatile fatty acids (BCVFA) supplements could promote lactation performance and milk quality by improving ruminal fermentation and milk fatty acid synthesis. This study was conducted ...to evaluate the effects of BCVFA supplementation on milk performance, ruminal fermentation, nutrient digestibility and mRNA expression of genes related to fatty acid synthesis in mammary gland of dairy cows. A total of 36 multiparous Chinese Holstein cows averaging 606±4.7 kg of BW, 65±5.2 day in milk (DIM) with daily milk production of 30.6±0.72 kg were assigned to one of four groups blocked by lactation number, milk yield and DIM. The treatments were control, low-BCVFA (LBCVFA), medium-BCVFA (MBCVFA) and high-BCVFA (HBCVFA) with 0, 30, 60 and 90 g BCVFA per cow per day, respectively. Experimental periods were 105 days with 15 days of adaptation and 90 days of data collection. Dry matter (DM) intake tended to increase, but BW changes were similar among treatments. Yields of actual milk, 4% fat corrected milk, milk fat and true protein linearly increased, but feed conversion ratio (FCR) linearly decreased with increasing BCVFA supplementation. Milk fat content linearly increased, but true protein content tended to increase. Contents of C4:0, C6:0, C8:0, C10:0, C12:0, C14:0 and C15:0 fatty acids in milk fat linearly increased, whereas other fatty acids were not affected with increasing BCVFA supplementation. Ruminal pH, ammonia N concentration and propionate molar proportion linearly decreased, but total VFA production and molar proportions of acetate and butyrate linearly increased with increasing BCVFA supplementation. Consequently, acetate to propionate ratios linearly increased. Digestibilities of DM, organic matter, CP, NDF and ADF also linearly increased. In addition, mRNA expressions of peroxisome proliferator-activated receptor γ, sterol regulatory element-binding factor 1 and fatty acid-binding protein 3 linearly increased, mRNA expressions of acetyl-coenzyme A carboxylase-α, fatty acid synthase and stearoyl-CoA desaturase quadratically increased. However, lipoprotein lipase mRNA expression was not affected by treatments. The results indicated that lactation performance and milk fat synthesis increased with BCVFA supplementation by improving ruminal fermentation, nutrient digestibility and mRNA expressions of genes related to milk fat synthesis.
We performed the broadband (1-100 keV) spectral analysis of the first Galactic Be ultraluminous X-ray pulsar (BeULX) Swift J0243.6+6124 observed by Insight-HXMT during the 2017−2018 outburst. The ...results show spectral transitions at two typical luminosities, roughly consistently with those reported previously via pure timing analysis. We find that the spectrum evolves and becomes softer and has higher cutoff energies until the luminosity reaches L1 (∼1.5 × 1038 erg s−1). Afterwards the spectrum becomes harder with lower cutoff energies until the luminosity increases to L2 (∼4.4 × 1038 erg s−1), around which the second spectral transition occurs. Beyond L2, the spectrum softens again and has larger cutoff energies. Similar behaviors were observed previously in other high-mass X-ray binary systems (HMXBs), especially for the second transition at higher luminosities, which is believed to have a correlation with the magnetic field of the harbored neutron star. Accordingly, we speculate that Swift J0243.6+6124 owns a neutron star with magnetic field strength >1013 G. The spectral transition at around L1 of Swift J0243.6+6124 is first observed thoroughly for any HMXB outburst characterized by strong evolution of the thermal component: the temperature of the blackbody drops sharply accompanied by a sudden increase of the blackbody radius. These spectral transitions can in principle be understood in a general scenario of balancing the emission patterns between the pencil and the fan beams at the magnetic pole, for which the extreme brightness of Swift J0243.6+6124 may provide an almost unique lab to probe the details.
Purpose
The purpose of this study was to investigate and evaluate the accuracy and the preoperative diagnostic value of high-resolution magnetic resonance imaging (MRI) techniques, three-dimensional ...time-of-flight (3D-TOF) and three-dimensional constructive interference in steady state (3D-CISS) sequence, solely or in combination for the detection of the relationship between the facial nerve and adjacent vessels in patients with hemifacial spasm (HFS).
Methods
A total of 95 patients with primary HFS were subject to 3D-TOF and 3D-CISS MRI. The MR images were then used to evaluate the anatomical neurovascular relationships, and the results were compared with the surgical findings. We categorized the neurovascular relationship into three types: compression, contact, and neighboring or distant. Compression and/or contacts between root exit zone (REZ) and vessels were defined as positive, whereas neighboring or distant was considered to be negative.
Results
3D-TOF combined with 3D-CISS assessment showed that 94 of 95 patients had artery compression or contact at REZ, whereas the remaining patient had compression at the peripheral branch of the facial nerve but not at REZ. The positive rates and the overall accuracy were 98.95 and 100 %, respectively, for the 3D-TOF combined with 3D-CISS assessment; 92.63 and 93.68 %, respectively, for the 3D-TOF assessment; and 85.26 and 86.32 %, respectively, for the 3D-CISS assessment. The positive rates and overall accuracy for the 3D-TOF combined with 3D-CISS assessment was significantly higher than those for the 3D-TOF or 3D-CISS assessment.
Conclusions
Combination of 3D-TOF with 3D-CISS imaging well delineates the relationship between the facial nerve and adjacent vessels in terms of increased positive rates and accuracy.
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