The Effect of Conditioning on the Flotation of Pyrrhotite in the Presence of Chlorite

The influence of conditioning on the flotation of pyrrhotite in the presence of chlorite was investigated through flotation tests, sedimentation tests, and X-ray photoelectron spectroscopy (XPS) analysis. The flotation results show that chlorite slimes dramatically impair the flotation of pyrrhotite. Sedimentation and flotation tests reveal that conditioning can effectively remove chlorite slimes from pyrrhotite surfaces, resulting in an enhanced flotation recovery of pyrrhotite. When mixed minerals were conditioned under the natural atmosphere, a faster conditioning speed and longer conditioning time decreased the flotation recovery of pyrrhotite. However, when mixed minerals were conditioned under a nitrogen atmosphere, a more intensive conditioning process provided better flotation results. XPS analyses illustrate that a faster conditioning speed and longer conditioning time under the natural atmosphere accelerates the oxidation of pyrrhotite, leading to a decrease in the flotation recovery of pyrrhotite

Effects of electrostatic therapy on nighttime sleep and daytime symptoms in patients with chronic insomnia: Evidences from an open label study

IntroductionTranscranial electric stimulation (TES) is a neuromodulation approach that applies low-intensity electrical current to the brain and has been proposed as a treatment for insomnia. Electrostatic therapy is a kind of TES and people do not have a feeling of electrical stimuli when the voltage of static electricity is lower than 2,000 volts. However, no studies have examined the effects of electrostatic therapy on objective sleep and daytime symptoms in patients with insomnia.Materials and methodsThirty chronic insomnia patients were included. All patients received a 6 week electrostatic therapy and three comprehensive assessments including two consecutive polysomnography (PSG) and daytime symptoms assessments, at pre-treatment, 3 week and 6 week of treatment. Insomnia Severity Index (ISI) was used to assess the severity of insomnia. Multiple sleep latency test (MSLT), Epworth Sleepiness Scale (ESS), and Flinders Fatigue Scale (FFS) were used to assess objective and self-reported daytime sleepiness and fatigue, respectively. Attention network test (ANT) was used to assess attention levels.ResultsTotal ISI scores decreased significantly at 3 weeks (p < 0.001) and 6 weeks (p < 0.001) after initiation of treatment. Furthermore, objective total sleep time (TST, p = 0.020) and sleep efficiency (SE, p = 0.009) increased and wake time after sleep onset (p = 0.012) decreased significantly after 6 weeks electrostatic therapy. Regarding daytime symptoms, ESS and FFS scores decreased significantly at 3 weeks (ESS, p = 0.047; FFS, p = 0.017) and 6 weeks (ESS, p = 0.008; FFS, p = 0.003) after initiation of treatment. Moreover, executive control improved significantly from pre-treatment to 3 weeks (p = 0.006) and 6 weeks (p = 0.013) and altering network improved significantly at 6 weeks (p = 0.003) after initiation of treatment. Secondary analyses showed that TST and SE improved significantly after electrostatic therapy in insomnia patients who slept < 390 min (all p-value < 0.05). However, no significant changes regarding TST and SE were observed in insomnia patients who slept ≥ 390 min.ConclusionElectrostatic therapy improves both nighttime sleep and daytime symptoms in patients with chronic insomnia. The effect on objective sleep appears to be stronger in patient with objective short sleep duration. Electrostatic therapy might be a therapeutic choice for insomnia patients with difficulty maintaining sleep and not responding to behavioral treatments.Clinical trial registration[www.clinicaltrials.gov], identifier [ChiCTR2100051590]

18F-Labeled GRPR Agonists and Antagonists: A Comparative Study in Prostate Cancer Imaging

Radiolabeled bombesin analogs are promising probes for cancer imaging of gastrin-releasing peptide receptor (GRPR). In this study, we developed 18F-labeled GRPR agonists and antagonists for positron emission tomography (PET) imaging of prostate cancer. GRPR antagonists ATBBN (D-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-NHCH2CH3) and MATBBN (Gly-Gly-Gly-Arg-Asp-Asn-D-Phe-Gln-Trp-Ala-Val-Gly-His-Leu-NHCH2CH3), and agonists AGBBN (Gln-Trp-Ala-Val-Gly-His-Leu-MetNH2) and MAGBBN (Gly-Gly-Gly-Arg-Asp-Asn-Gln-Trp-Ala-Val-Gly-His-Leu-MetNH2) were radiolabeled with 18F via 4-nitrophenyl 2-18F-fluoropropionate. The in vitro receptor binding, cell uptake, and efflux properties of the radiotracers were studied on PC-3 cells. An in vivo PET study was performed on mice bearing PC-3 tumors. Direct 18F-labeling of known GRPR antagonist ATBBN and agonist AGBBN did not result in good tumor targeting or appropriate pharmacokinetics. Modification was made by introducing a highly hydrophilic linker Gly-Gly-Gly-Arg-Asp-Asn. Higher receptor binding affinity, much higher cell uptake and slower washout were observed for the agonist 18F-FP-MAGBBN over the antagonist 18F-FP-MATBBN. Both tracers showed good tumor/background contrast, with the agonist 18F-FP-MAGBBN having significantly higher tumor uptake than the antagonist 18F-FP-MATBBN (P < 0.01). In conclusion, Gly-Gly-Gly-Arg-Asp-Asn linker significantly improved the pharmacokinetics of the otherwise hydrophobic BBN radiotracers. 18F-labeled BBN peptide agonists may be the probes of choice for prostate cancer imaging due to their relatively high tumor uptake and retention as compared with the antagonist counterparts

Effect of direct current electric field intensity and electrolyte layer thickness on oxygen reduction in simulated atmospheric environment

The effect of direct current (DC) electric field and electrolyte layer thickness on oxygen reduction in simulated atmospheric environment were investigated using electrochemical measurements. The results show that the limiting diffusion current density (ilim) decreases with increasing the thin electrolyte layers (TELs) thickness but it increases with increasing the DC electric field intensity. The potential shifts negatively with the DC electric field. It is found that the DC electric field enables OH− ions to quickly migrate from the solution/electrode interface to the electrolyte layer. All these features promote the cathodic reduction process thereby enhancing the metal corrosion rate

Two‐Dimensional Design Strategy to Construct Smart Fluorescent Probes for the Precise Tracking of Senescence

The tracking of cellular senescence usually depends on the detection of senescence‐associated β‐galactosidase (SA‐β‐gal). Previous probes for SA‐β‐gal with this purpose only cover a single dimension: the accumulation of this enzyme in lysosomes. However, this is insufficient to determine the destiny of senescence because endogenous β‐gal enriched in lysosomes is not only related to senescence, but also to some other physiological processes. To address this issue, we introduce our fluorescent probes including a second dimension: lysosomal pH, since de‐acidification is a unique feature of the lysosomes in senescent cells. With this novel design, our probes achieved excellent discrimination of SA‐β‐gal from cancer‐associated β‐gal, which enables them to track cellular senescence as well as tissue aging more precisely. Our crystal structures of a model enzyme E. coli β‐gal mutant (E537Q) complexed with each probe further revealed the structural basis for probe recognition.<br/

Experimental study on mechanical properties of filling-bulk ce-menting combination body

In order to study the influence of caved rocks in the goaf on the backfilling body in the backfilling mining, uniaxial compression test are carried out on the backfilling body-cemented granular body combination with different granular heights, discrete element lithology and backfilling body strength. The uniaxial compression failure of the combination body specimen is monitored in real time by using the three-dimensional acoustic emission positioning technology. The deformation and failure corresponding to the AE events in the loading process is characterized by combining the time parameters of AE events with the starting time points of the four stages of the stress-strain curve. Based on this, the failure model for the interface of the combination body is established. The results show that the height of granular is negatively correlated with the strength of the combination body, and the uniaxial compressive strength of the combination body with the backfilling height ratio of 1:4 is only 55.0 % of that of the single backfilling body. The discrete element lithology and the strength of backfilling body are positively correlated with the strength of the combination body. Although high-strength backfilling body can improve the uniaxial compressive strength of the combination body, the higher the strength of filling body in the combination body, the more serious the strength reduction of the combination body. When the particle lithology in cemented bulk is siltstone with low strength, the uniaxial compressive strength of the combination body is only 42.9% of that of single combination body. The siltstone with smaller compressive strength will have a fracture plane due to shear failure during the failure, and the limestone with larger compressive strength can withstand shear load by using the shear strength of the granular particles. When the cementing matrix in the cemented granular fails or the particles in the cemented granular are broken, the interface of the backfilling body and the cemented granular undergoes non-uniform compression deformation, resulting in the stress concentration on the backfilling body on the interface damaged by the cemented granular, resulting in the shear failure of the upper backfilling body locally, and the failure of backfilling body is the contribution of both axial stress and non-uniform deformation of the interface

Genome of Pythium myriotylum Uncovers an Extensive Arsenal of Virulence-Related Genes among the Broad-Host-Range Necrotrophic Pythium Plant Pathogens

The Pythium (Peronosporales, Oomycota) genus includes devastating plant pathogens that cause widespread diseases and severe crop losses. Here, we have uncovered a far greater arsenal of virulence factor-related genes in the necrotrophic Pythium myriotylum than in other Pythium plant pathogens. The genome of a plant-virulent P. myriotylum strain (~70 Mb and 19,878 genes) isolated from a diseased rhizome of ginger (Zingiber officinale) encodes the largest repertoire of putative effectors, proteases, and plant cell wall-degrading enzymes (PCWDEs) among the studied species. P. myriotylum has twice as many predicted secreted proteins than any other Pythium plant pathogen. Arrays of tandem duplications appear to be a key factor of the enrichment of the virulence factor-related genes in P. myriotylum. The transcriptomic analysis performed on two P. myriotylum isolates infecting ginger leaves showed that proteases were a major part of the upregulated genes along with PCWDEs, Nep1-like proteins (NLPs), and elicitin-like proteins. A subset of P. myriotylum NLPs were analyzed and found to have necrosis-inducing ability from agroinfiltration of tobacco (Nicotiana benthamiana) leaves. One of the heterologously produced infection-upregulated putative cutinases found in a tandem array showed esterase activity with preferences for longer-chain-length substrates and neutral to alkaline pH levels. Our results allow the development of science-based targets for the management of P. myriotylum-caused disease, as insights from the genome and transcriptome show that gene expansion of virulence factor-related genes play a bigger role in the plant parasitism of Pythium spp. than previously thought. IMPORTANCE Pythium species are oomycetes, an evolutionarily distinct group of filamentous fungus-like stramenopiles. The Pythium genus includes several pathogens of important crop species, e.g., the spice ginger. Analysis of our genome from the plant pathogen Pythium myriotylum uncovered a far larger arsenal of virulence factor-related genes than found in other Pythium plant pathogens, and these genes contribute to the infection of the plant host. The increase in the number of virulence factor-related genes appears to have occurred through the mechanism of tandem gene duplication events. Genes from particular virulence factor-related categories that were increased in number and switched on during infection of ginger leaves had their activities tested. These genes have toxic activities toward plant cells or activities to hydrolyze polymeric components of the plant. The research suggests targets to better manage diseases caused by P. myriotylum and prompts renewed attention to the genomics of Pythium plant pathogens

Energy Management Strategy of Hybrid Ships Using Nonlinear Model Predictive Control via a Chaotic Grey Wolf Optimization Algorithm

Reducing energy consumption and carbon emissions from ships is a major concern. The development of hybrid technologies offers a new direction for the rational distribution of energy. Therefore, this paper establishes a torque model for internal combustion engines and motors based on first principles and fitting the data collected from the test platform; in turn, it develops a model for fuel consumption and carbon emissions. Furthermore, the effect of irregular waves using an extended Kalman filter is estimated as well as feedback to the controller as a disturbance variable. Then, a parallel hybrid ship energy management strategy based on a new real-time nonlinear model of predictive control is designed to achieve energy conservation and emission decrease. A hybrid algorithm of chaotic optimization combined with grey wolf optimization is utilized to solve the nonlinear optimization problem in the nonlinear model predictive control strategy and a local refined search is performed using sequential quadratic programming. Through the comparison of fuel consumption, carbon emissions, real-time performance, and the engine load path, the superiority of the nonlinear model predictive control energy management strategy based on the chaotic grey wolf optimization algorithm is verified