Polyvinyl alcohol (PVA) is the main pollutant in printing and dyeing wastewaters. This pollutant exhibits great demand, poor biodegradability and refractory degradation. In this study, PVA wastewater ...treatment experiments were conducted in a stably operating baffled anaerobic bioreactor (ABR) by using simulated PVA wastewater. The PVA degradation pathway and mechanism of the mixed dominant PVA-degrading bacterial strains were identified through the analysis of their degradation products. From the results, we inferred that PVA was degraded in a stepwise process under the synergistic action of different extracellular and intracellular enzymes produced by the mixed dominant PVA-degrading bacterial strains. In this process, PVA was first degraded into ketones, fatty acids and alcohols. It was then regenerated into acetic acid, hydrogen and carbon dioxide. Finally, these substances could be further utilized by methanogens. PVA was thus degraded completely. This study may serve as a reference for future works on the degradation of PVA in the ecological environment. It may also guide the sustainable development of PVA.
A nasopharyngeal carcinoma (NPC) mass screening trial using a combination of immunoglobulin A antibodies to Epstein-Barr virus capsid antigen and nuclear antigen-1 by enzyme-linked immunosorbent ...assay in addition to indirect mirror examination in the nasopharynx and/or lymphatic palpation (IMLP) was conducted in southern China. Cantonese aged 30-59 years residing in 2 cities randomly selected by cluster sampling, Sihui and Zhongshan, were invited to participate in this screening from May 2008 through May 2010. Participants were offered fiberoptic endoscopy examination and/or pathologic biopsy if their serologic tests reached our predefined level of high risk or if results from the physical examination indicated possible cancer (i.e., were IMLP positive). A total of 28,688 individuals were voluntarily screened in the initial round. The overall NPC detection rate was 0.14% (41/28,688) with an early diagnosis rate of 68.3% (28/41) during the first year of follow-up. Thirty-eight of 41 cases (92.7%) were detected among the high-risk group, and 7 of 41 cases (17.1%) were detected among the IMLP-positive group. The 2 Epstein-Barr virus serologic tests by enzyme-linked immunosorbent assay could be a feasible alternative for NPC screening in endemic areas. Further follow-up is needed to examine whether screening has an effect on decreasing mortality from NPC in these areas.
•Effect of Y content on grain refinement in the simulated coarse-grained heat-affected zone of X70 steel was investigated.•In-situ observation of austenite grain growth and microstructural ...transformation during thermal cycle.•The misorientation and crystallographic grain size of investigated steels with the EBSD analysis.•Two different grain refinement mechanisms were obtained in 0.034 wt.%-Y and 0.075 wt.%-Y steels, respectively.
This study aims to investigate the influence of Y content on grain refinement in the simulated coarse-grained heat-affected zone (CGHAZ) of X70 pipeline steels. The results explored that two different grain refinement mechanisms were presented in 0.034 wt.%-Y and 0.075 wt.%-Y steels, respectively. The Y2O2S inclusions and YP precipitates are formed in 0.034 wt.%-Y steel instead of the YP inclusions and more YP precipitates in 0.075 wt.%-Y steel. The grain refinement mechanism in the simulated CGHAZ of 0.034 wt.%-Y steel mainly depends on the formation of acicular ferrite induced by Y2O2S inclusion. Whereas, the grain refinement mechanism in the simulated CGHAZ of 0.075 wt.%-Y steel primarily relies on the austenite boundary pinning effect by higher density of YP precipitates.
Aims
The effect of increasing dietary cation–anion difference (DCAD) on rumen fermentation and ruminal microbial community in dairy cows under heat stress (HS) conditions were evaluated.
Methods and ...Results
This study was performed as a two‐period cross‐over design during the summer season, with eight lactating dairy cows randomly distributed to either a control DCAD diet (CON: 33·5 mEq/100 g DM) or high DCAD diet (HDCAD: 50·8 mEq/100 g DM). Throughout the present study, the temperature and humidity index (THI; 80·2 ± 4·29) was generally elevated above the threshold (THI = 72) that is reported to cause HS in lactating dairy cows. Rumen liquid samples were collected on 15 and 21 d during each 21 d‐period. The absolute concentration of ruminal total volatile fatty acid (TVFA) in HDCAD treatment was significantly (P < 0·05) higher than those in the control, whilst the ruminal pH, NH3‐N, and VFA molar percentages were unaffected through increasing DCAD. Furthermore, the copy numbers of the cellulolytic bacteria Ruminococcus albus and Ruminococcus flavefaciens in rumen fluid significantly (P < 0·05) rose along with the increment of DCAD. Although the Alpha diversity indexes and the bacterial microbiota structure were unaffected, increasing DCAD significantly (P < 0·05) enriched the phylum Fibrobacteres and genus Fibrobacter in the microflora of rumen fluid, whilst the genera Flexilinea and Dubosiella were the most differentially abundant taxa in the control.
Conclusions
Increasing DCAD under HS conditions resulted in a greater concentration of total VFA without affecting rumen bacteria diversity or structure, although the enrichment of some cellulolytic/hemicellulolytic bacteria was observed.
Significance and Impact of the Study
The present study provides information on the modulation of rumen fermentation and microbial community through the increment of DCAD in Holstein dairy cows under HS conditions.
Defining the correlates of protection necessary to manage the COVID-19 pandemic requires the analysis of both antibody and T cell parameters, but the complexity of traditional tests limits ...virus-specific T cell measurements. We tested the sensitivity and performance of a simple and rapid SARS-CoV-2 spike protein-specific T cell test based on the stimulation of whole blood with peptides covering the SARS-CoV-2 spike protein, followed by cytokine (IFN-γ, IL-2) measurement in different cohorts including BNT162b2-vaccinated individuals (n = 112), convalescent asymptomatic and symptomatic COVID-19 patients (n = 130), and SARS-CoV-1-convalescent individuals (n = 12). The sensitivity of this rapid test is comparable to that of traditional methods of T cell analysis (ELISPOT, activation-induced marker). Using this test, we observed a similar mean magnitude of T cell responses between the vaccinees and SARS-CoV-2 convalescents 3 months after vaccination or virus priming. However, a wide heterogeneity of the magnitude of spike-specific T cell responses characterized the individual responses, irrespective of the time of analysis. The magnitude of these spike-specific T cell responses cannot be predicted from the neutralizing antibody levels. Hence, both humoral and cellular spike-specific immunity should be tested after vaccination to define the correlates of protection necessary to evaluate current vaccine strategies.
The microstructural framework of a high-pressure die-cast hypoeutectic AlSi10MnMg alloy and the formation mechanism of two type abnormal eutectic bands under varied die casting shot speeds are ...proposed. Before the eutectic band zone solidifies, the central external solidified crystals (ESCs) dendrite-enriched zone and surface chilling zone have been developed. The residual Si-rich melt stars to solidify from surface to center along the formed feeding path of framework. In addition, liquid filling speed in high pressure die casting (HPDC) will not alter the sequential solidification sequence but affect the formation of eutectic band. The high-speed liquid flow causes relatively dispersive ESCs from surface to center while low-speed liquid flow accelerates the migration of ESCs to center and thus causes the formation of a larger dendritic network which is decisive to the different formation mechanism of eutectic bands. Eutectic band position before solidification serving as an interface between solidified zone and central dendritic network exhibits the characteristics of a higher velocity melt flow, a lower solid fraction and a fewer ESCs content. This study provides insights into near-rapid solidified behavior combining liquid filling process and it is expected to expand the conception to other die cast alloys.
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•The microstructural framework in a HPDC AlSi10MnMg alloy is studied.•The formation mechanism of two type eutectic bands is studied.•Eutectic band serving as an interface between solidified zone and central dendritic network.
Research into novel one-dimensional (1D) materials and associated structural transitions is of significant scientific interest. It is widely accepted that a 1D system with a short-range interaction ...cannot have 1D phase transition at finite temperature. Herein, we propose a series of new stable carbon nanotubes by rolling up penta-graphene sheets, which exhibit fascinating well-defined 1D phase transitions triggered by axial strain. Our first-principles calculations show that such penta-graphene nanotubes (PGNTs) are dynamically stable by phonon calculations, but transform from a tri-layer structure to a highly defective single-walled nanotube at low temperature in molecular dynamics simulations. We show that moderate compressive strains can drive structural transitions of (4,4), (5,5), and (6,6) PGNTs, during which the distances of neighboring carbon dimers in the inner shell have a sudden drop, corresponding to dimer-dimer nonbonding to bonding transitions. After such transition, the tubes become much more thermally stable and undergo semiconductor-metal transitions under increasing strain. The band gaps of PGNTs are not sensitive to chirality whereas they can be tuned effectively from visible to short-wavelength infrared by appropriate strain, making them appealing materials for flexible nano-optoelectronics. These findings provide useful insight into unusual phase transitions in low-dimensional systems.
The objective of this research was to test the hypothesis that in ovo feeding of l-arginine (Arg) may improve hatchability and posthatch performance in domestic pigeons (Columba livia). A completely ...randomized design (n = 3) with an Arg feeding treatment (Arg group, 1.14 mg Arg dissolved in 200 µL of 0.75% NaCl buffered saline as 1% concentration compared to total Arg in the egg), a buffered saline feeding treatment (SC group, 7.5 g NaCl dissolved in 1 L sterile distilled water as the concentration of poultry physiological saline), and a nonfeeding treatment (NC group) was used. Six squabs from each treatment were randomly sampled on day of hatch (DOH), posthatch d 7 (D7), and posthatch d 14 (D14), respectively. Hatchability, hatch time, BW, organ development, and carcass traits were examined. Results showed that in ovo feeding of the Arg solution increased (P < 0.05) the hatchability and advanced (P < 0.05) the hatching time in comparison with those of the other groups. Body weight of pigeon squabs that received Arg in ovo feeding was heavier (P < 0.05) on DOH and D14 than that of the NC group, and a greater (P < 0.05) BW gain from DOH to D14 and D7 to D14 was observed. Three clusters of 12 organs were classified according to the changes of organ indices. Squabs provided the Arg in ovo feeding treatment gained a priority in organ development. The heart index and gizzard index on D7 and the proventriculus index on D14 of squabs receiving Arg in ovo feeding were increased (P < 0.05) compared to those of the other groups. The brain index on DOH, the small intestine index and pancreas index on D7, and the liver index, pancreas index, and spleen index on D14 of squabs fed Arg were higher (P < 0.05) than those of the NC group. The spleen index on D7 and the small intestine index on D14 of squabs provided the Arg feeding treatment were enhanced (P < 0.05) compared with those of the SC group. The semieviscerated carcass weight of squabs receiving Arg was higher (P < 0.05) on D14 than that of other groups. The absolute weight of breast meat yield on D7 and breast meat yield percentage on D7 and D14 were improved (P < 0.05) in the Arg group compared with the NC group. The leg meat percentage on D7 and the carcass weight, eviscerated carcass weight, and absolute weight of breast meat yield on D14 were increased (P < 0.05) in the Arg group compared with those of the SC group. The results of this study indicate that in ovo feeding of pigeon embryos with Arg may have beneficial effects on squab hatch performance and early posthatch performance.
The reaction mechanisms and rate constants of N, N-diethylhydroxylamine (DEHA) with
·
OH, CO
3
−
·
, e
aq
−
and
·
H were studied. Results show that
·
OH radicals oxidize DEHA by hydrogen abstraction ...from DEHA’s hydroxyl group to form transient (C
2
H
5
)
2
NO
·
, which has an absorption maximum at 395 nm. The transient intermediates for the reactions of DEHA with CO
3
−
·
and e
aq
−
, as well as protonated DEHA with
·
H, show no absorption peak between 300 and 800 nm. The rate constants for the reactions of DEHA with
·
OH, CO
3
−
·
and e
aq
−
, also protonated DEHA with
·
H, were measured.
Abstract Tumefactive demyelinating lesions (TDLs) that may resemble brain neoplasms or abscesses are uncommon but noteworthy. A solid knowledge of how to distinguish TDLs from malignancy or infection ...is a key step to avoid unnecessary medical or surgical interventions. Almost all the intracranial demyelination diseases after liver transplantation (LT) refer to central pontine myelinolysis or extrapontine myelinolysis; TDLs after LT have never been reported. In 2005, a 45-year-old Chinese male underwent orthotopic LT due to “acute on chronic liver failure” in our hospital. He took triple anti-rejection drugs including tacrolimus, mycophenolate mofetil, and corticosteroids after LT. In 2010, he was admitted for right limb weakness, and the head magnetic resonance imaging and magnetic resonance spectroscopy revealed the lesions were more likely to be TDLs. His symptoms disappeared after he was administered corticosteroid therapy which proved the diagnosis. Five years later, he was admitted again to hospital with dizziness and double version. The magnetic resonance image and magnetic resonance spectroscopy showed that the new solitary lesion in the cerebellum may in fact be the new TDL. He received corticosteroid therapy and was discharged after symptoms improved. Herein, to our knowledge, we reported the first case of TDL after LT. We reported this case to provide helpful information to clinicians about intracranial demyelination diseases after LT which maybe are not always central pontine myelinolysis or extrapontine myelinolysis.
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