Micro groove, as a typical surface texture, has played an important role in the development of many advanced fields. This paper introduced an electrochemical machining of micro groove using masked ...porous cathode. A porous metallic plate covered with a mask was prepared as the masked porous cathode. During machining, the masked porous cathode was covered on the workpiece, and the electrolyte could flow into the machining region through the porous structure in the cathode for machining. As the machining unit was closed, the distribution of electrical field was uniform on the machining surface, which could improve the machining accuracy. In addition, the masked porous mask had no damage during machining and could be reused, which improved the machining efficiency. With this method, multiphysics coupling model, including flow field model, electric current model, heat transfer model, reactant transport model, and moving mesh model, was built to investigate their influence on the machining process with different flow modes. The simulation and experiment results indicated that compared with other two flow modes, jet flow mode could provide a high electrolyte velocity in the machining region around the nozzle, and the mass transfer process was enhanced, which was helpful to improve the machining quality. The effect of pulse duty cycle was investigated, and the pulse duty cycle of 20% with the frequency of 2 kHz could further improve the mass transfer process and was preferred to generate micro groove with low standard deviation and roughness. In addition, with the applied voltage rising, the depth of micro groove increased, and increasing the nozzle reciprocating motion number could enhance the mass transfer process during machining, which further improved machining quality. Finally, with the optimized flow mode and machining parameters, a group of ten micro grooves were well generated by using a masked porous cathode with ten micro slits, and the width was about 330 μm with the depth of 45 μm.
Chronic lymphocytic leukemia (CLL) is a progressive malignancy of mature B-cells that involves the peripheral blood (PB), lymph nodes (LNs) and bone marrow (BM). Although the majority of CLL cells ...are in a resting state, small populations of proliferating cells exist; however, the anatomical site of active cell proliferation remains to be definitively determined. Based on findings that CLL cells in LNs have increased expression of B-cell activation genes, we tested the hypothesis that the fraction of 'newly born' cells would be highest in the LNs. Using a deuterium oxide (
H) in vivo labeling method in which patients consumed deuterated (heavy) water (
H
O), we determined CLL cell kinetics in concurrently obtained samples from LN, PB and BM. The LN was identified as the anatomical site harboring the largest fraction of newly born cells, compared to PB and BM. In fact, the calculated birth rate in the LN reached as high a 3.3% of the clone per day. Subdivision of the bulk CLL population by flow cytometry identified the subpopulation with the CXCR4
CD5
phenotype as containing the highest proportion of newly born cells within each compartment, including the LN, identifying this subclonal population as an important target for novel treatment approaches.
Charged particles can be accelerated to high energies by collisionless shock waves in astrophysical environments, such as supernova remnants. By interacting with the magnetized ambient medium, these ...shocks can transfer energy to particles. Despite increasing efforts in the characterization of these shocks from satellite measurements at Earth’s bow shock as well as powerful numerical simulations, the underlying acceleration mechanism or a combination thereof is still widely debated. Here we show that astrophysically relevant super-critical quasi-perpendicular magnetized collisionless shocks can be produced and characterized in the laboratory. We observe the characteristics of super-criticality in the shock profile as well as the energization of protons picked up from the ambient gas to hundreds of kiloelectronvolts. Kinetic simulations modelling the laboratory experiment identified shock surfing as the proton acceleration mechanism. Our observations not only provide direct evidence of early-stage ion energization by collisionless shocks but also highlight the role played by this particular mechanism in energizing ambient ions to feed further stages of acceleration. Furthermore, our results open the door to future laboratory experiments investigating the possible transition to other mechanisms, when increasing the magnetic field strength, or the effect that induced shock front ripples could have on acceleration processes.Proton acceleration by a super-critical collisionless shock is observed in laboratory experiments, and numerical simulations suggest shock surfing as the underlying acceleration mechanism.
Abstract
Quasar-driven galactic outflows are a major driver of the evolution of massive galaxies. We report observations of a powerful galactic-scale outflow in a
z
= 3 extremely red and ...intrinsically luminous (
L
bol
≃ 5 × 10
47
erg s
−1
) quasar SDSSJ1652 + 1728 with the Near-infrared Spectrograph on board JWST. We analyze the kinematics of rest-frame optical emission lines and identify the quasar-driven outflow extending out to ∼10 kpc from the quasar with a velocity offset of (
v
r
= ± 500 km s
−1
) and high velocity dispersion (FWHM = 700–2400 km s
−1
). Due to JWST’s unprecedented surface brightness sensitivity in the near-infrared, we unambiguously show that the powerful high velocity outflow in an extremely red quasar encompasses a large swath of the host galaxy’s interstellar medium. Using the kinematics and dynamics of optical emission lines, we estimate the mass outflow rate—in the warm ionized phase alone—to be at least 2300 ± 1400
M
⊙
yr
−1
. We measure a momentum flux ratio between the outflow and the quasar accretion disk of ∼1 on a kpc scale, indicating that the outflow was likely driven in a relatively high (>10
23
cm
−2
) column density environment through radiation pressure on dust grains. We find a coupling efficiency between the bolometric luminosity of the quasar and the outflow of 0.1%, matching the theoretical prediction of the minimum coupling efficiency necessary for negative quasar feedback. The outflow has sufficient energetics to drive the observed turbulence seen in shocked regions of the quasar host galaxy, which are likely directly responsible for prolonging the time that it takes for gas to cool efficiently.
Objectives
This study correlated immunohistochemical studies with fluorodeoxyglucose (FDG) uptake on positron emission tomography–computed tomography (PET–CT) and identified prognostic factors for ...radiotherapy (RT)‐based treatment outcomes in patients with squamous cell carcinoma of the oropharynx and hypopharynx.
Methods
Genomic data from pre‐treatment biopsy specimens (Glut1, CAIX, VEGF, HIF‐1α, EGFR, Ki‐67, Bcl‐2, CLAUDIN‐4, YAP‐1, c‐Met and p16) of 76 patients were analysed using tissue microarrays. FDG uptake was evaluated using the maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG).
Results
The overexpression of Glut1 positively associated with increased values of the SUVmax, MTV and TLG, whereas VEGF and HIF‐1α expression with the MTV and TLG, respectively. A VEGF immunoreactive score (IRS) >2 (P = 0.001, hazard ratio HR = 3.94) and an MTV defined by an SUV of 2.5 (MTV2.5) >14.5 mL (P = 0.004, HR = 3.31) were prognostic factors for low cause‐specific survival, whereas a VEGF IRS >2 (P = 0.02, HR = 2.83) for low primary relapse‐free survival.
Conclusion
The overexpression of Glut1, VEGF and HIF‐1α associated with increased FDG uptake. For patients with pharyngeal cancer requiring RT, the treatment outcome can be stratified by VEGF and MTV2.5.
Our understanding of the dynamics of ion collisional energy loss in a plasma is still not complete, in part due to the difficulty and lack of high-quality experimental measurements. These ...measurements are crucial to benchmark existing models. Here, we show that such a measurement is possible using high-flux proton beams accelerated by high intensity short pulse lasers, where there is a high number of particles in a picosecond pulse, which is ideal for measurements in quickly expanding plasmas. By reducing the energy bandwidth of the protons using a passive selector, we have made proton stopping measurements in partially ionized Argon and fully ionized Hydrogen plasmas with electron temperatures of hundreds of eV and densities in the range 10
-10
cm
. In the first case, we have observed, consistently with previous reports, enhanced stopping of protons when compared to stopping power in non-ionized gas. In the second case, we have observed for the first time the regime of reduced stopping, which is theoretically predicted in such hot and fully ionized plasma. The versatility of these tunable short-pulse laser based ion sources, where the ion type and energy can be changed at will, could open up the possibility for a variety of ion stopping power measurements in plasmas so long as they are well characterized in terms of temperature and density. In turn, these measurements will allow tests of the validity of existing theoretical models.
In this study, the microbial interactions among cocultures of Streptococcus thermophilus (St) with potential probiotics of Bifidobacterium animalis ssp. lactis (Ba) and Lactiplantibacillus plantarum ...(Lp) in fermented milk were investigated during a storage period of 21 d at 4°C, in terms of acidifying activity (pH and titratable acidity), viable counts, and metabolites. A nontargeted metabolomics approach based on ultra-high-performance liquid chromatography coupled with mass spectrometry was employed for mapping the global metabolite profiles of fermented milk. Probiotic strains cocultured with St accelerated milk acidification, and improved the microbial viability compared with the single culture of St. The St–Ba/Lp treatment manifested a higher bacteria viability and acidification ability in comparison with the St–Ba or the St–Lp treatment. Relative quantitation of 179 significant metabolites was identified, including nucleosides, AA, short peptides, organic acids, lipid derivatives, carbohydrates, carbonyl compounds, and compounds related to energy metabolism. The principal component analysis indicated that St treatment and coculture treatments displayed a complete distinction in metabolite profiles, and Lp had a larger effect than Ba on metabolic profiles of fermented milk produced by cofermentation with St during storage. The heat map in combination with hierarchical cluster analysis showed that the abundance of metabolites significantly varied with the starter cultures over the storage, and high abundance of metabolites was observed in either St or coculture samples. The St-Ba/Lp treatment showed relatively high abundance for the vast majority of metabolites. These findings suggest that the profile of the metabolites characterizing fermented milk samples may depend on the starter cultures, and incorporation of probiotics may considerably influence the metabolomic activities of fermented milks.
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