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The lightweight of liquefied natural gas (LNG) tanker can reduce transportation cost and improve transportation efficiency. However, in lightweight design, the random vibration analysis based on fluid–structure interaction (FSI) is difficult, which demands to be effectively solved by simplifying the finite element model and load. The vibration test and fluid–structure interaction modal numerical analysis of a tanker model were carried out, respectively, and the results are in good agreement. Taking the DC18 LNG tanker as an example, the random vibration response analysis was carried out based on the fluid–structure interaction modal numerical analysis, and the random fatigue damage coefficient of the support region of the inner container was obtained, which was used as the benchmark for the model and load simplification. The finite element model of the LNG tanker was simplified by applying the equivalent liquid mass to the walls of the inner container in the form of density. It is found that when the equivalent liquid mass ratio is 40%, the random vibration response characteristics of the DC18 LNG tanker are close to the actual structure. In the static calculation of the simplified model, the stress response of the container support area is close to the actual structural when the equivalent road spectrum load is 0.95 g vertical acceleration. In this case, the stress result and the overall damage coefficient equivalent to the actual structure can be obtained just by static calculation, which greatly simplifies the solution process.

Context The evidence of long-term polyethylene glycol recombinant human GH (PEG-rhGH) in pediatric GH deficiency (GHD) is limited. Objective This study aimed to examine the effectiveness and safety of long-term PEG-rhGH in children with GHD in the real world, as well as to examine the effects of dose on patient outcomes. Design A prospective, observational, posttrial study (NCT03290235). Setting, participants and intervention Children with GHD were enrolled from 81 centers in China in 4 individual clinical trials and received weekly 0.2 mg/kg/wk (high-dose) or 0.1 to Main outcomes measures Height SD score (Ht SDS) at 12, 24, and 36 months. Results A total of 1170 children were enrolled in this posttrial study, with 642 patients in the high-dose subgroup and 528 in the low-dose subgroup. The Ht SDS improved significantly after treatment in the total population (P < 0.0001), with a mean change of 0.53 ± 0.30, 0.89 ± 0.48, 1.35 ± 0.63, 1.63 ± 0.75 at 6 months, 12 months, 24 months, and 36 months, respectively. In addition, the changes in Ht SDS from baseline were significantly improved in the high-dose subgroup compared with the low-dose subgroup at 6, 12, 24, and 36 months after treatment (all P < 0.05). A total of 12 (1.03%) patients developed serious adverse events. There was no serious adverse event related to the treatment, and no AEs leading to treatment discontinuation or death occurred. Conclusions PEG-rhGH showed long-term effectiveness and safety in treating children with GHD. Both dose subgroups showed promising outcomes, whereas PEG-rhGH 0.2 mg/kg/wk might show additional benefit.

In this study, the pitting corrosion behavior of 13Cr4Ni martensitic stainless steel (BASE) and that modified with rare earth (REM) in 0.1 mol/L NaCl solution were characterized. Techniques such as automatic secondary electron microscope (ASPEX PSEM detector), scanning electron microscope (SEM), transmission electron microscope (TEM), scanning Kelvin probe force microscope (SKP), potentiodynamic and potentiostatic polarizations were employed. The results obtained indicate that BASE steel contains Al2O3/MnS, Al2O3 and MnS inclusions, while REM steels contain (La, Ce, Cr, Fe)-O and (La, Ce, Cr, Fe)-O-S inclusions. Compared with BASE steel, REM steel is more susceptible to induce the metastable pitting nucleation and repassivation, whereas it restrains the transition from metastable pitting to stable pitting. Adding 0.021% rare earth element to BASE steel can reduce the number and area of inclusions, while that of 0.058% can increase the number and enlarged the size of inclusions, which is also the reason that pitting corrosion resistance of 58REM steel is slightly lower than that of 21REM steel. In the process of pitting corrosion induced by Al2O3/MnS inclusions, MnS is preferentially anodic dissolved, and also the matrix contacted with Al2O3 is subsequently anodic dissolved. For REM steels, anodic dissolution preferentially occurs at the boundary between inclusions and matrix, while (La, Ce, Cr, Fe)-O inclusions chemically dissolve in local acidic environment or are separated from steel matrix. The chemically dissolved substance (La3+ and Ce3+) of (La, Ce, Cr, Fe)-O inclusions are concentrated in pitting pits, which inhibits its continuous growth.

Background Pressure ulcers (PU) refer to local tissue ulceration and necrosis caused by long-term compression and friction brought on by tissue ischemia and hypoxia. Diabetic wounds do not easily heal, and once a pressure ulceration occurs, it is difficult to deal with. The purpose of this study was to analyze the current research status of PUs in diabetic patients. Methods The Science Citation Index Expanded (SCI-E) database was searched with terms of "Pressure Ulcer" and "Diabetes". Citespace software was used to analyze the annual distribution of the number of target documents and the distribution of countries, institutions, journals, authors, and keywords used in these works. Results In all, 1271 documents were retrieved, with a total citation frequency of 47,081, and an h-index of 101. The top 5 countries in terms of the number of publications were the United States, the United Kingdom, China, Australia, and the Netherlands; the top 5 countries in centrality were the Netherlands, the United States, Canada, Japan, and France. The institutions with the greatest number of publications were the University of Amsterdam, Cardiff University, The University of Washington, and the University of Manchester. The institutions with the highest centrality were the University of Amsterdam, the University of Groningen, the University of Washington, the University of Adelaide, Baylor College of Medicine, and Queensland University of Technology. The authors with a highest number of publications were Bus SA, Apelqvist J, and the International Working Group on the Diabetic Foot, and Hinchliffe RJ. Only 2 authors had a centrality score above 0.01. Journals such as Diabetes Metabolism Research and Reviews, Diabetes Care, and Journal of Wound Care showed considerable influence in this field. Keyword analysis indicated that the use of keywords in this field is not uniform, and the focus of research on PUs in diabetic patients lies the risk and management of foot ulcers. Conclusions There are few studies concerning PUs in patients with diabetes and little collaboration between authors. The current focus in this field is on the risk and management of foot ulcers.

Bacteriophage T4 has enormous potential for biomedical applications due to its large size, capsid architecture, and high payload capability for protein and DNA delivery. However, it is not very easy to genetically engineer its genome heavily modified by cytosine hydroxymethylation and glucosylation. The glucosyl hydroxymethyl cytosine (ghmC) genome of phage is completely resistant to most restriction endonucleases and exhibits various degrees of resistance to CRISPR-Cas systems. Here, we found that the type V CRISPR-Cas12a system, which shows efficient cleavage of ghmC-modified genome when compared to the type II CRISPR-Cas9 system, can be synergistically employed to generate recombinant T4 phages. Focused on surface display, we analyzed the ability of phage T4 outer capsid proteins Hoc (highly antigenic outer capsid protein) and Soc (small outer capsid protein) to tether, in vivo, foreign peptides and proteins to T4 capsid. Our data show that while these could be successfully expressed and displayed during the phage infection, shorter peptides are present at a much higher copy number than full-length proteins. However, the copy number of the latter could be elevated by driving the expression of the transgene using the strong T7 RNA polymerase expression system. This CRISPR-inspired approach has the potential to expand the application of phages to various basic and translational research projects.

In this work, the corrosion behavior of medium-carbon steels (45, 45Cu and 45Cuq steels) in acidic chloride environment was investigated. The results indicated that the micro-galvanic effect between the anodic ferrite matrix phase and the cathodic cementite secondary phase notably affected the corrosion resistance of the three steels. For 45 steel, serious pitting corrosion happened in and around the pearlite regions, and a large number of lamellar cementite was fixed in the corrosion pits. Meanwhile, the continuously increasing superficial area of cathodic cementite enhanced the micro-galvanic corrosion, resulting in a rapidly increase in corrosion rate with time. While for 45Cu and 45Cuq steels, macroscopic uniform corrosion occurred, and the cementite accumulation was markedly reduced as compared with 45 steel, thus the micro-galvanic effect was weakened and the corrosion rate was decreased accordingly. Among these, 45Cuq steel showed the most stable and excellent corrosion resistance during long-term corrosion, indicating the occurrence of a synergistic effect between cementite spheroidization and Cu alloying, thereby significantly improving the corrosion resistance of 45 steel.

An experimental model for simulating the corrosion of carbon steel fasteners (bolt and nut) composed of a contact carbon steel electrode (CCSE) and an exposed bare carbon steel plate electrode (BCSE) was designed. The effect of coupling on the corrosion process of the galvanically coupled carbon steel electrode was evaluated and compared with the self-corrosion process observed independently at the exposed and contact regions. Results obtained indicated that at an equal area ratio and uncoupled conditions, the corrosion rate is accelerated in the surface directly exposed to bulk solution compared to the bolt surface in contact with the nut. A coupling current was recorded when the exposed surface (BCSE) was electrically connected with the contact surface (CCSE); with the CCSE acting as the anode thereby suppressing the corrosion process in the exposed surface. By implication, the galvanic coupling between CCSE and BCSE increased the corrosion rate of CCSE. The difference in oxygen supply was responsible for the coupling effect observed in the system as there was no decrease in the solution pH. Moreover, varying the cathode-to-anode area (Sc/Sa) ratio significantly influenced the corrosion current density as increased Sc/Sa ratio resulted in an accelerated galvanic corrosion process. The corroded surfaces and interfaces were analysed using stereomicroscopy and scanning electron microscopy. X-ray diffractometry was adopted for corrosion product characterization. The results obtained showed supportive evidence of the corrosion behaviour in carbon steel fasteners.

This study reports on the effect of the addition of Glycine to Hank’s solution on the in-vitro corrosion behavior of AZ31 magnesium (Mg) alloy at 37 ℃ and a pH of 7.4 studied by using potentiodynamic polarization (PDP), hydrogen collecting techniques and electrochemical impedance spectroscopy (EIS) in combination with surface characterization techniques such as optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy analysis (XPS). The results reveal that adsorption of glycine initially subdues the dissolution of AZ31 Mg alloy while in long run it enhances the dissolution of the alloy due to the commencement of the chelation effect of glycine with Ca2+ released from hydroxyapatite. The chelation of glycine with Ca2+ induces the formation of cracks in the surface film which further promotes the dissolution of AZ31 Mg alloy thereby forming a porous corrosion products layer on the surface of the alloy. As a result, both the continuous dissolution of AZ31 magnesium alloy and the hydrogen evolution rate (HER) are enhanced with increasing the immersion time in Hank’s solution.

The corrosion evolution of steel disposal container largely depends on the evolution of surrounding bentonite environment in the long-term geological disposal of high-level radioactive wastes. This study focused on the influence of the deteriorated bentonite sediments on the corrosion behavior of NiCu low alloy steel in the top supernatant and bottom slurry formed by Gaomiaozi bentonite and 0.05 M NaHCO3 + 0.1 M NaCl + 0.1 M Na2SO4 solution. In the top supernatant, the cathodic process of the steel corrosion was transformed from the reduction in oxygen to the reduction in ferric corrosion products with time as same as that in the blank solution. While in the bottom bentonite slurry, the cathodic process always maintained as the hydrogen evolution reaction due to the coverage of more bentonite sediments. Meanwhile, the corrosion rate of NiCu steel was obviously decreased. In addition, the localized corrosion tendency of the steel could also be reduced by the large amount of deteriorated bentonite sediments.

The corrosion behavior of mild steel in a simulated coastal atmosphere environment has been investigated by the indoor accelerated wet/dry cyclic corrosion acceleration test (CCT), scanning electron microscopy (SEM), Raman spectroscopy and electrochemical measurements. During the CCT test of 60 cycles, the evolution of logarithmic (corrosion rate) vs. logarithmic (CCT cycles) presents a turning point at the 5th cycle, presenting a tendency to increase first and then decrease to gradually stabilize as the CCT cycle prolonged. Before the 5th cycle, γ-FeOOH and β-FeOOH and Fe3O4 were detected, respectively. And then, α-FeOOH as a new chemical composition was detected in the subsequent corrosion cycles. It is found that, after long term corrosion, the rust separated into a relatively dense inner layer rich with α-FeOOH and a loose outer layer rich with γ-FeOOH, both of which have poor electrical conductivity. The rapid increase of corrosion rate in the early stage since reducible corrosion products are involved in the reduction process of the cathode which promotes the dissolution of the anodic metal substrate. Afterward, as the rust layer thickens, the resistance of the rust increases, and the aggressive ions diffusion is blocked, gradually suppressing the electrochemical corrosion process. At last, when the composition and distribution of the rust layer remain stable, the corrosion presents a fluctuating speed around a certain value during the cracking and self-repairing process of the rust layer.

The effect of adding d -fructose to simulated body fluid (SBF) on the corrosion behavior of AZ31 magnesium (Mg) alloy at 37 °C and at a pH of 7.4 was studied by potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), potentiostatic polarization and hydrogen (H2) collecting techniques, Raman spectroscopy technique, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy analysis (XPS) and Fourier transformed infrared (FTIR). The results demonstrated that the addition of fructose enhanced the deposition of phosphates forming thick and compact corrosion products, which inhibited the transmission of aggressive ions into the Mg substrate. As a result, both the anodic dissolution of Mg and negative difference effect (NDE) were suppressed. Thus, the corrosion resistance of AZ31 Mg alloy in SBF was significantly improved.

The corrosion damage of 20SiMn steel by sulphate-reducing bacteria (SRB) and the mitigation effect of organic silicon quaternary ammonium salt (OSA) were studied in sterilized mild alkaline simulated concrete pore solution (STR) with different additions of SRB and OSA at pH 9.35 for 28 days. Uniform corrosion occurs in STR medium while slight localized corrosion is observed in STR + OSA medium, and localized pitting corrosion occurs in STR + SRB and STR + SRB + OSA media. The largest pit depth reduces from 36.70 μm in STR + SRB medium to 3.31 μm in STR + SRB + OSA medium due to the mitigation effect of OSA. The corrosion rate reflected by weight loss and electrochemical impedance spectroscopy (EIS) results presents the order of STR

The corrosion behavior of the as-received steel and the spheroidized steel in acidic chloride environment was investigated. The results indicate the corrosion mode and corrosion rate of two steels are diverse due to their difference in microstructure. For as-received steel with ferrite-pearlite microstructure, severe localized corrosion happens on the pearlite regions, and plenty of cathodic cementite remains in the pits, further strengthening the micro-galvanic effect and accelerating the corrosion rate. While for spheroidized steel with tempered martensite microstructure, the nanosized cementite particles evenly distributed on the ferrite substrate are easy to fall off, which can significantly reduce the cementite accumulation on the steel surface, relieving the acceleration effect of micro-galvanic corrosion.

Process industries often use B-ring self-tightening sealing structures and rely on interference assembly to meet the initial sealing requirements. Therefore, determining reasonable B-ring material, size and interference is crucial to ensure the sealing performance of the structure. In this paper, based on elastic deformation analysis, the deformation co-ordination equation of a B-ring sealing structure was established, and a sealing contact pressure calculation formula was obtained, with discussion of the main factors affecting sealing performance. With the finite element method, transient temperature field analysis was carried out for startup and shutdown load cases, and contact analysis was carried out for interference assembly, startup and shutdown. Based on the evaluation criteria of sealing performance with proposed sealing rate and leakage parameters, the effects of material properties, interference, B-ring size, etc., on sealing performance were investigated, revealing that although a B-ring with high material yield stress can meet the sealing requirements, both the B-ring and the sealing surface of a reactor body will yield plastic deformation. B-rings with a low material yield stress exhibit obvious plastic deformation during startup and leak during shutdown. However, leakage parameters can be minimized by smaller interference and moderate wave radius.

By means of first-principles calculations, we have proposed an ab initio modeling to establish a formula between the hydrogen evolution rate and its overpotential of hydrogen evolution reaction (HER), relating with three different rate determining mechanisms, when Volmer reaction, Tafel reaction and Heyrowsky reaction are the rate determining steps of the entire reaction, respectively. Within this modeling, the free energy ( Δ G H * ) of the adsorbed hydrogen atom and the concentration of hydrogen ions in the solution have been correlated to the exchange current density. The hydrogen evolution modeling has been validated by available experimental results. Furthermore, by combining the previously proposed first-principles modeling of the anodic dissolution and this modeling of the HER in the electrochemical corrosion, the polarization curves of the 18 crystallographic surfaces of pure Mg have been theoretically derived. It has been found that in a neutral solution ( p H = 7 ) the corrosion current densities (icorr) of the 18 crystallographic surfaces range from 10 − 3.477 to 10 − 0.455 A/cm2 and their corresponding corrosion potentials (Ecorr) range from −1.36 to −0.892 VSHE, respectively. The base (0001) surface exhibits a lower corrosion rate of 10 − 3.345 A/cm2, whereas the crystal (21 3 ¯ 0) surface has a fast corrosion rate of 10 − 0.455 A/cm2. The calculations even reveal that except for Ag, all the other alloying elements considered here accelerate the rates of the cathodic HER. In agreement with theoretical results, the experimentally measured polarization curves of the Mg-1Zn and Mg-2Sn alloys verify that both Zn and Sn additions accelerate the rate of the HER of Mg.

Scattering and correlation properties of a two-photon (TP) pulse are studied in a four-terminal waveguide system, i.e., two one-dimensional waveguides connected by a Jaynes-Cummings emitter (JCE). The wave function approach is utilized to exactly calculate the real-time dynamic evolution of the TP transport. When the width of the incident TP Gaussian pulse is much larger than the photon wavelength, the TP transmission spectra approach that of the corresponding single photon cases and are almost independent of the pulse width. On the contrary, as the pulse width is comparable to the photon wavelength, the TP transmission and correlation both show strong dependence on the pulse width. The resonant scattering due to the JCE and the photon interference together determine the TP correlation. When the distance between the TPs is small, the TP correlations between any two terminals for the scattered TP pulse are much different from those for the incident TP pulse and therefore, such a four-terminal waveguide system provides a way to control the TP correlation.

Bacteriophage T4 has enormous potential for biomedical applications due to its large size, capsid architecture, and high payload capability for protein and DNA delivery. However, it is not very easy to genetically engineer its genome heavily modified by cytosine hydroxymethylation and glucosylation. The glucosyl hydroxymethyl cytosine (ghmC) genome of phage is completely resistant to most restriction endonucleases and exhibits various degrees of resistance to CRISPR-Cas systems. Here, we found that the type V CRISPR-Cas12a system, which shows efficient cleavage of ghmC-modified genome when compared to the type II CRISPR-Cas9 system, can be synergistically employed to generate recombinant T4 phages. Focused on surface display, we analyzed the ability of phage T4 outer capsid proteins Hoc (highly antigenic outer capsid protein) and Soc (small outer capsid protein) to tether

The corrosion kinetics and patina (corrosion products) layer evolution of galvanized steel submitted to wet/dry cyclic corrosion test in a simulated coastal-industrial atmosphere was investigated. The results show that zinc coating has a greater corrosion rate during the initial period and a lower corrosion rate during the subsequent period, and the patina composition and structure can greatly affect the corrosion kinetics evolution of zinc coating. Moreover, Zn5(OH)6(CO3)2 and Zn4(OH)6SO4 are identified as the main stable composition and exhibit an increasing relative amount; while Zn12(OH)15Cl3(SO4)3 cannot stably exist and diminish in the patina layer as the corrosion develops.

The effect of tin addition on the atmospheric corrosion behavior of a low-alloy steel in simulated coastal-industrial atmosphere has been investigated by indoor wet/dry cyclic corrosion test (CCT). The results indicate that tin addition can obviously make the steel substrate more resistant to atmospheric corrosion by suppressing the cathodic H+ reduction reaction, and but tin addition is not of obvious beneficial effect when the steel is covered with a thicker rust layer during long-term corrosion process. The reason lies in the fact that the presence of un-reduced H+ can lower the electrolyte pH value and lead to a loose and porous rust layer on tin-containing steel sample than that on tin-free steel sample. In addition, the 120 CCT cycles corrosion process of the two steels can be divided into three stages. Both the tin-free and tin-containing steels show an increasing corrosion rate during the initial corrosion stage and then exhibit a decreasing corrosion rate during the second and third corrosion stages. Moreover, tin addition makes the tin-containing steel rust layer have a higher amount of α-FeOOH and lower amount of γ-FeOOH and Fe3O4 than the tin-free steel rust layer.

The microstructures in B4C-6061Al composite hot-pressed at different temperatures (560 °C, 620 °C) are characterized, and the corrosion behavior of the materials is studied using electrochemical tests and quasi in-situ TEM observations. The composite fabricated at 620 °C is composed of more matrix-reinforcement reaction products (Al3BC at the interfaces and MgB2 in the alloy matrix). Corrosion occurred slightly in boric acid but severely in Cl−-containing solution. The B4C/Al interface in both samples is preferentially attacked and the MgB2 dispersions in the high-temperature-pressed composite remarkably promoted the pitting. Dealloying of Mg2Si precipitate does not obviously deteriorate the corrosion resistance of the composite.

This work investigated the influence of Sn and Mo on corrosion behavior of ferrite-pearlite steel in the simulated bottom plate environment of cargo oil tank. The results indicate that the corrosion rate of three ferrite-pearlite steels increased with extending the immersion time due to the continuous accumulation of the residual Fe3C. However, the addition of Sn or the combined addition of Sn and Mo could reduce the corrosion rate of Sn containing steel and Sn-Mo containing steel to 37.5% and 20% of that of carbon steel, respectively. Moreover, the cathodic reaction of Sn containing steel and Sn-Mo containing steel was always controlled by the charge transfer step during the whole immersion test, while that of carbon steel was gradually transformed into the diffusion-controlled process. These results were mainly related with the deposition of metallic Sn and Mo on the steel surface. The metallic Sn and Mo with uniform distribution restrained the galvanic effect through suppressing both the anodic dissolution of ferrite and cathodic hydrogen evolution reaction on the residual Fe3C.