► The effect of hydrogen charging on the pitting in DSS was studied by SKPFM. ► The low-potential areas occur in the ferrite/austenite boundaries or inside ferrite. ► These areas may be considered as ...the nucleation sites of pitting induced by hydrogen. ► The continuous evolution of Volta potential after hydrogen charging was observed. ► The images exhibit the effects of hydrogen on ferrite and austenite were different.
The influence of the hydrogen charging on the pitting corrosion in duplex stainless steel was investigated by the scanning Kelvin probe PROBE force microscopy. The Volta potential maps of the hydrogen charged sample revealed that some low potential areas emerged at the ferrite/austenite boundaries or inside the ferrite phases, which may be considered as preferential nucleation sites of pitting corrosion induced by hydrogen. Moreover, a continuous evolution of Volta potential images indicated that the effects of hydrogen on ferrite and austenite were different due to different hydrogen behavior in two phases, which was confirmed by the work function of ferrite and austenite.
Two experiments were conducted to determine the effects of Lactobacillus plantarum B1 on broiler performance, cecal bacteria, and ileal and cecal short chain fatty acids (SCFA). The study also ...determined whether it was necessary to feed Lactobacillus throughout the entire growth period or if the beneficial effects could be obtained by supplementation during the starter or finisher period only. Experiment 1 was conducted with 72 broilers assigned to 2 treatments (N = 6). One treatment was the basal diet (Con), and the other was the basal diet supplemented with 2 × 109 cfu/kg L. plantarum B1 (Wh). In experiment 2, 144 one-day-old broilers were assigned to 4 treatments (N = 6) including a basal diet (Con), the basal diet supplemented with 2 × 109 cfu/kg L. plantarum B1 during d one to 21 only (St), the basal diet supplemented with L. plantarum B1 during d 22 to 42 only (Fn), and, finally, the basal diet supplemented with L. plantarum B1 from d one to 42 (Wh). Experiment 1 showed that L. plantarum B1 enhanced broiler average daily gain (ADG) and feed conversion ratio (FCR). In experiment 2, during the starter period, broilers in the Wh and St treatments had higher ADG (P < 0.05) than broilers in the Con and Fn, while during the finisher period, broilers in the Wh and Fn had higher ADG (P < 0.01) and improved FCR (P < 0.01) compared with broilers in the Con and St. On d 42, broilers in the Wh and Fn had decreased E. coli (P < 0.05) and increased lactic acid bacteria (P < 0.05) in their cecal digesta. L. plantarum B1 also increased (P < 0.05) ileal mucosal sIgA as well as ileal and cecal SCFA. However, L. plantarum B1 had no effect on intestinal morphology. In conclusion, L. plantarum B1 plays a positive role in broilers. Supplementation during the finisher period or the entire growth period is superior to supplementation during the starter period only.
Hydrogen effect on semiconductivity and compositions of passive films formed on ferrite and austenite phases in a duplex stainless steel were investigated by current sensing atomic force microscopy ...and X-ray photoelectron spectroscopy. It is demonstrated that hydrogen significantly increases the conductivity of passive film due to the increase of OH
/O
ratio. The passive film on austenite has higher conductivity than that on ferrite after hydrogen charging due to more hydrogen in austenite. The presence of hydrogen causes an inversion of conductivity type of passive film from p-type to n-type, attributed to the chemical composition change.
The large-scale magnetic field of our Galaxy can be probed in three dimensions using Faraday rotation of pulsar signals. We report on the determination of 223 rotation measures from polarization ...observations of relatively distant southern pulsars made using the Parkes radio telescope. Combined with previously published observations, these data give clear evidence for large-scale counterclockwise fields (viewed from the north Galactic pole) in the spiral arms interior to the Sun and weaker evidence for a counterclockwise field in the Perseus arm. However, in interarm regions, including the solar neighborhood, we present evidence that suggests that large-scale fields are clockwise. We propose that the large-scale Galactic magnetic field has a bisymmetric structure with reversals on the boundaries of the spiral arms. Streaming motions associated with spiral density waves can directly generate such a structure from an initial, inwardly directed radial field. Large-scale fields increase toward the Galactic center, with a mean value of about 2 kG in the solar neighborhood and 4 kG at a galactocentric radius of 3 kpc.
The L12-strengthened heterostructure Co40Cr20Ni30Mo2Al4Ti4 (at%) high-entropy alloys (HEAs) exhibit excellent tensile mechanical properties over a wide temperature range. In particular, the yield ...strength of this alloy reaches up to about 1400 MPa from room temperature to 600 °C, which is much higher than that of most alloys. The reasons for the different mechanical behaviors of this alloy above and below the transformation temperature are discussed. Unique super-lattice stacking faults appear in the high-temperature deformed alloys, which may be attributed to the decrease of super-lattice stacking fault energy when the temperature increases. In the present work, the deformation mechanisms of precipitation-strengthened HEAs at high temperatures are preliminarily explored, which has guiding significance for the development of advanced high-temperature structural materials.
In the present work, three kinds of precipitates with different morphologies, structures, sizes, and volume fractions were obtained via energetically-tuning the microstructures of the ...nano-precipitated CoCrFeNiTi0.2 high-entropy alloy (HEA). Subjected to the heavy cold rolling immediately after homogeneous precipitation, L12 structured spherical nano-particles with an average size of 16.5 nm rapidly grow into 200 nm-sized spherical ones due to Ostwald ripening. On the other hand, superfluous mechanical energy storage energetically facilitates the phase transformation from spherical L12 to rod-shaped D024 structures for initially formed nano-precipitates. Besides, some other newly formed nano-precipitates with an average size of 6.5 nm are available, originating from heavily plastically deformed-induced nucleated sites. Multi-scale precipitates interact with dislocations in different ways. The strengthening provided by dislocations cutting through smaller nano-particles and bypassing grown ones account for 57.7% and 42.3% of precipitation strengthening, respectively, while rod-shaped precipitates can act as equivalent interfaces to hinder dislocation movement. Their synergistic effect has achieved remarkable strengthening and toughening. Specially, dislocation slips dominate at 298 K, while stacking faults (SFs) assist plastic deformation at 77 K. Compared with 298 K, the yield strength (YS) and ultimate tensile strength (UTS) of the current HEAs at 77 K are increased by 38.9% and 38.2% to 1 GPa and 1.5 GPa, respectively, and the tensile strain is slightly increased to 35% instead of loss, realizing excellent strength and plasticity combination. Theoretically established strengthening models agree well room-temperature and cryogenic yield strengths experimentally. Moreover, the tensile elongation is effectively predicted by the Whitehouse-Clyne model. This strengthening strategy of energetically-tuning polymorphous precipitates provides the basic guidance to develop high-performance nano-precipitated alloys. The current strengthening and plasticity models can be employed to well predict the mechanical properties of such kinds of alloys at cryogenic temperatures.
Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) ...aimed to evaluate the performance of enhanced linear-splinter amplification sequencing, a previously described cell-free DNA (cfDNA) methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary, and pancreas.
A customized panel of 161 984 CpG sites was constructed and validated by public and in-house (cancer: n = 249; non-cancer: n = 288) methylome data, respectively. The cfDNA samples from 1693 participants (cancer: n = 735; non-cancer: n = 958) were retrospectively collected to train and validate two multi-cancer detection blood test (MCDBT-1/2) models for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1010 participants (cancer: n = 505; non-cancer: n = 505). Simulation using the cancer incidence in China was applied to infer stage shift and survival benefits to demonstrate the potential utility of the models in the real world.
MCDBT-1 yielded a sensitivity of 69.1% (64.8%-73.3%), a specificity of 98.9% (97.6%-99.7%), and tissue origin accuracy of 83.2% (78.7%-87.1%) in the independent validation set. For early-stage (I-III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%-65.0%). In the real-world simulation, MCDBT-1 achieved a sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%-46.4%, and increasing 5-year survival rate by 33.1%-40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.
In this large-scale clinical validation study, MCDBT-1/2 models showed high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.
•MCDBT-1 had a sensitivity of 69.1% and a specificity of 98.9% in detecting six cancers.•In the real world, MCDBT-1 decreased late-stage incidence by 38.7%-46.4% and increased 5-year survival rate by 33.1%-40.4%.•In parallel, MCDBT-2 was set at a lower specificity but a higher sensitivity than MCDBT-1 and had an ideal performance.
Hydrostatic pressure (HP) effects on corrosion process of X70 steel in 3.5% NaCl solution have been investigated by situ electrochemical impedance spectroscopy (EIS), immersion tests and Raman ...spectra. These results indicate HP affects the corrosion behavior of the X70 steel during the whole immersion period. At the initial immersion, HP promotes the electrochemical reaction of corrosion process. Pitting initiation rate and propagation are both promoted by HP, corrosion rate increases with HP at the initial immersion period. At the stable immersion period, inner layer corrosion product is complete at 0.1 MPa, obvious cracks can be observed at 10 MPa. HP promotes Cl− transport and adsorption on the rust layer, corrosion rate slightly increases with HP.
Serine-Selective Bioconjugation Vantourout, Julien C; Adusumalli, Srinivasa Rao; Knouse, Kyle W ...
Journal of the American Chemical Society,
10/2020, Letnik:
142, Številka:
41
Journal Article
Recenzirano
Odprti dostop
This Communication reports the first general method for rapid, chemoselective, and modular functionalization of serine residues in native polypeptides, which uses a reagent platform based on the ...P(V) oxidation state. This redox-economical approach can be used to append nearly any kind of cargo onto serine, generating a stable, benign, and hydrophilic phosphorothioate linkage. The method tolerates all other known nucleophilic functional groups of naturally occurring proteinogenic amino acids. A variety of applications can be envisaged by this expansion of the toolbox of site-selective bioconjugation methods.
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