Highly anisotropic Fe3C microflakes constructed by solid-state phase transformation for efficient microwave absorption

Soft magnetic materials with flake geometry can provide shape anisotropy for breaking the Snoek limit, which is promising for achieving high-frequency ferromagnetic resonances and microwave absorption properties. Here, two-dimensional (2D) Fe3C microflakes with crystal orientation are obtained by solid-state phase transformation assisted by electrochemical dealloying. The shape anisotropy can be further regulated by manipulating the thickness of 2D Fe3C microflakes under different isothermally quenching temperatures. Thus, the resonant frequency is adjusted effectively from 9.47 and 11.56 GHz under isothermal quenching from 700 °C to 550 °C. The imaginary part of the complex permeability can reach 0.9 at 11.56 GHz, and the minimum reflection loss (RLmin) is -52.09 dB (15.85 GHz, 2.90 mm) with an effective absorption bandwidth (EAB≤-10 dB) of 2.55 GHz. This study provides insight into the preparation of high-frequency magnetic loss materials for obtaining high-performance microwave absorbers and achieves the preparation of functional materials from traditional structural materials.

Rapid Plasma Electrolytic Oxidation Synthesis of Intermetallic PtBi/MgO/Mg Monolithic Catalyst for Efficient Removal of Organic Pollutants

The intermetallic PtBi/MgO/Mg monolithic catalyst was first prepared using non-equilibrium plasma electrolytic oxidation (PEO) technology. Spherical aberration-corrected transmission electron microscope (ACTEM) observation confirms the successful synthesis of the PtBi intermetallic structure. The efficiency of PtBi/Mg/MgO catalysts in catalyzing the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4 was demonstrated. The activity factor for the catalyst is 31.8 s-1 g-1, which is much higher than reported values. In addition, the resultant catalyst also exhibits excellent catalytic activity in the organic pollutant reaction of p-nitrobenzoic acid (p-NBA) and methyl orange (MO). Moreover, benefiting from ordered atomic structures and the half-embedded PtBi nanoparticles (NPs), the catalyst demonstrates excellent stability and reproducibility in the degradation of 4-NP. This study provides an example of a simple method for the preparation of intermetallic structures as catalysts for organic pollutant degradation.

Tuning the electronic structure of Pd by the surface configuration of Al2O3 for hydrogenation reactions

The electronic interaction between a metal and a support modulates the electronic structures of supported metals and plays an important role in manipulating their catalytic performance. However, this interaction is mainly realized in heterogeneous catalysts composed of reducible oxides. Herein, we demonstrate the electronic interaction between γ-Al2O3 and η-Al2O3 with varying acid-base properties and supported Pd nanoparticles (NPs) of 2 nm in size. The strength and number of acid-base sites on the supports and catalysts were systemically characterized by FT-IR spectroscopy and TPD. The supported Pd NPs exhibit electron-rich surface properties by receiving electrons from the electron-donating basic sites on γ-Al2O3, which are beneficial for catalyzing the hydrogenation of nitrobenzene. In contrast, Pd NPs loaded on η-Al2O3 are electron-deficient because of the rich electron-withdrawing acid sites of η-Al2O3. As a result, Pd/η-Al2O3 exhibits higher catalytic activity in phenylacetylene hydrogenation than Pd/γ-Al2O3. Our results suggest a promising route for designing high-performance catalysts by adjusting the acid-base properties of Al2O3 supports to maneuver the electronic structures of metals.

Reactive Molecular Dynamics Simulations of Polystyrene Pyrolysis

Polymers' controlled pyrolysis is an economical and environmentally friendly solution to prepare activated carbon. However, due to the experimental difficulty in measuring the dependence between microstructure and pyrolysis parameters at high temperatures, the unknown pyrolysis mechanism hinders access to the target products with desirable morphologies and performances. In this study, we investigate the pyrolysis process of polystyrene (PS) under different heating rates and temperatures employing reactive molecular dynamics (ReaxFF-MD) simulations. A clear profile of the generation of pyrolysis products determined by the temperature and heating rate is constructed. It is found that the heating rate affects the type and amount of pyrolysis intermediates and their timing, and that low-rate heating helps yield more diverse pyrolysis intermediates. While the temperature affects the pyrolytic structure of the final equilibrium products, either too low or too high a target temperature is detrimental to generating large areas of the graphitized structure. The reduced time plots (RTPs) with simulation results predict a PS pyrolytic activation energy of 159.74 kJ/mol. The established theoretical evolution process matches experiments well, thus, contributing to preparing target activated carbons by referring to the regulatory mechanism of pyrolytic microstructure.

Immunomodulatory effect of Ti-Cu alloy by surface nanostructure synergistic with Cu2+ release

The inflammatory response induced by implant/macrophage interaction has been considered to be one of the vital factors in determining the success of implantation. In this study, TiCuNxOy coating with an immunomodulatory strategy was proposed for the first time, using nanostructured TiCuNxOy coating synthesized on Ti-Cu alloy by oxygen and nitrogen plasma-based surface modification. It was found that TiCuNxOy coating inhibited macrophage proliferation but stimulated macrophage preferential activation and presented an elongated morphology due to the surface nanostructure. The most encouraging discovery was that TiCuNxOy coating promoted the initial pro-inflammatory response of macrophages and then accelerated the M1-to-M2 transition of macrophages via a synergistic effect of fast-to-slow Cu2+ release and surface nanostructure, which was considered to contribute to initial infection elimination and tissue healing. As expected, TiCuNxOy coating released desirable Cu2+ and generated a favorable immune response that facilitated HUVEC recruitment to the coating, and accelerated proliferation, VEGF secretion and NO production of HUVECs. On the other hand, it is satisfying that TiCuNxOy coating maintained perfect long-term antibacterial activity (≥99.9%), mainly relying on Cu2O/CuO contact sterilization. These results indicated that TiCuNxOy coating might offer novel insights into the creation of a surface with immunomodulatory effects and long-term bactericidal potential for cardiovascular applications.

Flatband λ-Ti3O5 towards extraordinary solar steam generation

Solar steam interfacial evaporation represents a promising strategy for seawater desalination and wastewater purification owing to its environmentally friendly character1-3. To improve the solar-to-steam generation, most previous efforts have focused on effectively harvesting solar energy over the full solar spectrum4-7. However, the importance of tuning joint densities of states in enhancing solar absorption of photothermal materials is less emphasized. Here we propose a route to greatly elevate joint densities of states by introducing a flat-band electronic structure. Our study reveals that metallic λ-Ti3O5 powders show a high solar absorptivity of 96.4% due to Ti-Ti dimer-induced flat bands around the Fermi level. By incorporating them into three-dimensional porous hydrogel-based evaporators with a conical cavity, an unprecedentedly high evaporation rate of roughly 6.09 kilograms per square metre per hour is achieved for 3.5 weight percent saline water under 1 sun of irradiation without salt precipitation. Fundamentally, the Ti-Ti dimers and U-shaped groove structure exposed on the λ-Ti3O5 surface facilitate the dissociation of adsorbed water molecules and benefit the interfacial water evaporation in the form of small clusters. The present work highlights the crucial roles of Ti-Ti dimer-induced flat bands in enchaining solar absorption and peculiar U-shaped grooves in promoting water dissociation, offering insights into access to cost-effective solar-to-steam generation.

Coexisting Ferroelectric and Ferrovalley Polarizations in Bilayer Stacked Magnetic Semiconductors

It has long been expected that the coexistence of ferroelectric and ferrovalley polarizations in one magnetic semiconductor could offer the possibility to revolutionize electronic devices. In this study, monolayer and bilayer YI₂ are studied. Monolayer YI₂ is a ferromagnetic semiconductor and exhibits a valley polarization up to 105 meV. All of the present bilayer YI₂ regardless of stacking orders show antiferromagnetic states. Interestingly, the bilayer YI₂ with 3R-type stackings shows not only valley polarization but also unexpected ferroelectric polarization, proving the concurrent ferrovalley and multiferroics behaviors. Moreover, the valley polarization of 3R-type bilayer YI₂ can be reversed by controlling the direction of ferroelectric polarization through an electric field or manipulating the magnetization direction using an external magnetic field. The amazing phenomenon is also demonstrated in 2D van der Waals LaI₂ and GdBr₂ bilayers. A design idea of multifunctional devices is proposed based on the concurrent ferrovalley and multiferroics characteristics.

Recent Progress for Single-Molecule Magnets Based on Rare Earth Elements

Single-molecule magnets (SMMs) have attracted much attention due to their potential applications in molecular spintronic devices. Rare earth SMMs are considered to be the most promising for application owing to their large magnetic moment and strong magnetic anisotropy. In this review, the recent progress in rare earth SMMs represented by mononuclear and dinuclear complexes is highlighted, especially for the modulation of magnetic anisotropy, effective energy barrier (U_eff) and blocking temperature (T_B). The terbium- and dysprosium-based SMMs have a U_eff of 1541 cm^-1 and an increased T_B of 80 K. They break the boiling point temperature of liquid nitrogen. The development of the preparation technology of rare earth element SMMs is also summarized in an overview. This review has important implications and insights for the design and research of Ln-SMMs.

[A comparative study for the efficacies of transaxillary non-inflatable endoscopic surgery versus traditional surgery for papillary thyroid carcinoma]

Objective: To compare the efficacies between open surgery and axillary non-inflatable endoscopic surgery in papillary thyroid carcinoma (PTC). Methods: A retrospective analysis was performed on 343 patients with unilateral PTC treated by traditional open surgery (201 cases) and transaxillary non-inflating endoscopic surgery (142 cases) from May 2019 to December 2021 in the Head and Neck Surgery of Sichuan Cancer Hospital. Among them, 97 were males and 246 were females, aged 20-69 years. 1∶1 propensity score matching (PSM) was performed on the enrolled patients, and the basic characteristics, perioperative clinical outcomes, postoperative complications, postoperative quality of life (Thyroid Cancer-Specific Quality of Life), aesthetic satisfaction and other aspects of the two groups were compared after successful matching. SPSS 26.0 software was used for statistical analysis. Results: A total of 190 patients were enrolled after PSM, with 95 cases in open group and 95 cases in endoscopic group. Intraoperative blood losses for endoscopic and open groups were [20 (20) ml vs. 20 (10) ml, M (IQR), Z=-2.22], postoperative drainage volumes [170 (70)ml vs. 101 (55)ml, Z=-7.91], operative time [135 (35)min vs. 95 (35)min, Z=-7.34], hospitalization cost [(28 188.7±2 765.1)yuan vs. (25 643.5±2 610.7)yuan, x¯±s, t=0.73], postoperative hospitalization time [(3.1±0.9)days vs. (2.6±0.9)days, t=-3.24], and drainage tube placement time [(2.5±0.8) days vs. (2.0±1.0)days, t=-4.16], with statistically significant differrences (all P<0.05). There was no significant difference in surgical complications (P>0.05). There were significant diffferences between two groups in the postoperative quality of life scores in neuromuscular, psychological, scar and cold sensation (all P<0.05), while there were no statistically significant differences in other quality of life scores (all P>0.05). In terms of aesthetic satisfaction 6 months after surgery, the endoscopic group was better than the open group, with statistically significant difference (χ²=41.47, P<0.05). Conclusion: Endoscopic thyroidectomy by a gasless unilateral axillary approach is a safe and reliable surgical method, which has remarkable cosmetic effect and can improve the postoperative quality of life of patients compared with the traditional thyroidectomy.

The performance of left/right adrenal volume ratio and volume difference in predicting unilateral primary aldosteronism

PURPOSE

The role of computed tomography (CT) in the diagnosis of primary aldosteronism (PA) warrants attention, since the success application of adrenal venous sampling (AVS) remains limited. We aimed to investigate the value of CT-based volumetric indicators, including left-versus-right-adrenal-volume ratio (L/Rv) and left-subtract-right-adrenal-volume difference (L - Rv), in the diagnosis of unilateral primary aldosteronism (UPA).

METHODS

A retrospective case-control study included 153 patients with PA and 1272 controls. AVS was used to classify patients into bilateral disease, left-sided disease, and right-sided disease groups.

RESULTS

Adrenal gland volume on both sides of PA patients was significantly larger than controls. The optimal cutoff values of L/Rv and L - Rv were 1.417 [area under the curve (AUC) 0.864] and 1.185 (AUC 0.827), respectively, for the diagnosis of left-sided PA, and 1.030 (AUC 0.767) and 0.220 (AUC 0.769), respectively, for the diagnosis of right-sided PA. The mean AUC for subsequent cross-validation ranged from 0.77 ± 0.03 to 0.86 ± 0.02. Based on the optimal cutoff values, the combination of L/Rv and L - Rv detected 69.6% of patients with left-sided PA and 74.3% of patients with right-sided PA, with a specificity of 93.5% and 89.0%, respectively. For a better clinical application, we reported the sub-optimal cutoffs corresponding to a specificity of 95%. A L/Rv higher than 1.431 and a L - Rv higher than 3.185 as sub-optimal cutoff values was detected in 26.1% of patients with left-sided PA (specificity: 97.2%). A L/Rv smaller than 0.892 and a L - Rv smaller than -0.640 could detect 48.6% of patients with right-sided PA (specificity: 97.5%).

CONCLUSIONS

CT-based L/Rv and L - Rv performed well in predicting UPA. The combination of L/Rv and L - Rv may serve as a potential indicator for guiding surgical decision making in centers without AVS programs.

Quantitative Evaluation of the Carrier Separation Performance of Heterojunction Photocatalysts: The Case of g-C3N4/SrTiO3

Heterojunction photocatalysts are of great interest in the energy and environmental fields, because of their potential to significantly increase the efficiency of harvesting solar energy. Advances in design have been hampered by the continued use of only qualitative analyses. Quantitative evaluation of the carrier separation performance is urgently needed for the design and application of heterojunction photocatalysts. Taking the g-C₃N₄/SrTiO₃ heterojunction as an example, we address the conventional energy band and electronic structure issues by first-principles analysis. After interface coupling, the band edge alignment reverses from that of the respective isolated states of the heterojunction components, suggesting new ways of thinking about the catalytic mechanism of the heterojunction. More significantly, we show the carrier separation performance of heterojunction photocatalysts can be quantitatively predicted by the nonadiabatic molecular dynamics method, enabling more precisely directed research and promoting the quantified design and application of heterojunction photocatalysis, making a contribution of great scientific significance.

Laparoscopic radical resection for rectal cancer in a patient with uncorrected truncus arteriosus type IV: A case report

Persistent truncus arteriosus is a rare congenital heart malformation which if not corrected, results in the death of about 50% of the patients, while fewer than 20% of the patients survive the first year of life. Here, we report the successful anesthetic management of an adult patient with uncorrected truncus arteriosus who presented for the laparoscopic radical resection of rectal cancer.

A Tale of Two Sites: Neighboring Atomically Dispersed Pt Sites Cooperatively Remove Trace H2 in CO-Rich Stream

Single-atom catalysts (SACs) exhibit distinct catalytic behavior compared with nano-catalysts because of their unique atomic coordination environment without the direct bonding between identical metal centers. How these single atom sites interact with each other and influence the catalytic performance remains unveiled as designing densely populated but stable SACs is still an enormous challenge to date. Here, a fabrication strategy for embedding high areal density single-atom Pt sites via a defect engineering approach is demonstrated. Similar to the synergistic mechanism in binuclear homogeneous catalysts, from both experimental and theoretical results, it is proved that electrons would redistribute between the two oxo-bridged paired Pt sites after hydrogen adsorption on one site, which enables the other Pt site to have high CO oxidation activity at mild-temperature. The dynamic electronic interaction between neighboring Pt sites is found to be distance dependent. These new SACs with abundant Pt-O-Pt paired structures can improve the efficiency of CO chemical purification.

Modulation of Osteogenesis and Angiogenesis Activities Based on Ionic Release from Zn-Mg Alloys

The enhancement of osteogenesis and angiogenesis remains a great challenge for the successful regeneration of engineered tissue. Biodegradable Mg and Zn alloys have received increasing interest as potential biodegradable metallic materials, partially due to the biological functions of Mg²⁺ and Zn²⁺ with regard to osteogenesis and angiogenesis, respectively. In the present study, novel biodegradable Zn-xMg (x = 0.2, 0.5, 1.0 wt.%) alloys were designed and fabricated, and the effects of adding different amounts of Mg to the Zn matrix were investigated. The osteogenesis and angiogenesis beneficial effects of Zn²⁺ and Mg²⁺ release during the biodegradation were characterized, demonstrating coordination with the bone regeneration process in a dose-dependent manner. The results show that increased Mg content leads to a higher amount of released Mg²⁺ while decreasing the Zn²⁺ concentration in the extract. The osteogenesis of pre-osteoblasts was promoted in Zn-0.5Mg and Zn-1Mg due to the higher concentration of Mg²⁺. Moreover, pure Zn extract presented the highest activity in angiogenesis, owing to the highest concentration of Zn²⁺ release (6.415 μg/mL); the proliferation of osteoblast cells was, however, inhibited under such a high Zn²⁺ concentration. Although the concentration of Zn ion was decreased in Zn-0.5Mg and Zn-1Mg compared with pure Zn, the angiogenesis was not influenced when the concentration of Mg in the extract was sufficiently increased. Hence, Mg²⁺ and Zn²⁺ in Zn-Mg alloys show a dual modulation effect. The Zn-0.5Mg alloy was indicated to be a promising implant candidate due to demonstrating the appropriate activity in regulating osteogenesis and angiogenesis. The present work evaluates the effect of the Mg content in Zn-based alloys on biological activities, and the results provide guidance regarding the Zn-Mg composition in designs for orthopedic application.

Bulk-immiscible CuAg alloy nanorods prepared by phase transition from oxides for electrochemical CO2 reduction

Combining Cu and Ag in an alloy state holds promise to serve as a tandem catalyst for electrocatalytic CO₂ reduction, but is restricted by immiscibility in the bulk. Here, a far-from-equilibrium method is developed to synthesize CuAg alloy by electroreduction of Cu₂Ag₂O₃ under a large cathodic overpotential. The alloy state of CuAg is conducive to the formation of C₂₊ molecules. A high formation rate of C₂H₄ of 159.8 μmol cm^-2 h^-1 is reached on the CuAg alloy nanorods, 2.3 times higher than that on pure Cu.

[Clinical features and prognoses of re-operated patients for persistent/recurrent papillary thyroid carcinoma]

Objective: To investigate the clinicopathological characteristics and the survival of re-operated patients for persistent/recurrent papillary thyroid carcinoma (PTC) and risk factors for re-recurrence after the second operation. Method: A retrospective analysis of 69 cases underwent re-operation for persistent/recurrent PTC in Sichuan Cancer Hospital from January 2010 to December 2016 was performed. There were 21 males and 48 females, aged 14-85 (44.8) years old. According to the imaging after initial treatment, they were divided into a recurrence group (42 cases) and a persistent disease/residual group (27 cases). The positive rates of ipsilateral paratracheal lymph node metastases at re-operation were calculated and compared by chi-square test. Patients were divided into different subgroups according to potential risk factors for re-recurrence. Kaplan-Meier (K-M) method was used for survival analysis. Results: The positive rate of ipsilateral paratracheal lymph node metastasis in recurrence group (15/42, 35.7%) was significantly lower than that in the persistent disease/residual group (17/27, 63.0%) (χ²=4.91, P<0.05). The follow-up period after re-operation was 60-104 months, with a median of 66 months, and 8 patients were lost to follow-up. Permanent hypoparathyroidism occurred in 2 cases (2.9%) and permanent recurrent laryngeal nerve palsy in 1 case (1.4%). Twenty patients had structural recurrences and/or distant metastases. The 5-year disease-specific survival rate was 92.8% and the 5-year recurrence-free survival rate was 68.1%. Survival analysis was performed on risk factors such as age≥55 years old, recurrent tumor diameter ≥4 cm, number of positive lymph nodes ≥ 10, and obvious extracapsular invasion (ENE). Among them, age and diameter of recurrent tumor had significant influences on recurrence-free survival rate (χ² was 6.36, 8.17, respectively, both P values<0.05). There was a statistically significant difference in recurrence-free survival rates between ENE(+) group and ENE(-) group (χ²=5.52, P<0.05). Conclusion: For the re-operated patients due to persistence/ recurrence PTC, attention should be paid to protecting the parathyroid gland and recurrent laryngeal nerve during re-operation. Timely and effective postoperative follow-up for patients aged ≥ 55 years, with recurrent tumor diameter ≥ 4 cm and ENE(+), can significantly improve their prognoses.

A high-hydrophilic Cu2O-TiO2/Ti2O3/TiO coating on Ti-5Cu alloy: Perfect antibacterial property and rapid endothelialization potential

In order to make novel antibacterial Ti-Cu alloy more suitable for cardiovascular implant application, a Cu-containing oxide coating was manufactured on Ti-Cu alloy by plasma-enhanced oxidation deposition in plasma enhanced chemical vapor deposition (PECVD) equipment to further improve the antibacterial ability and the surface bioactivity. The results of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and water contact angle indicated that a sustainably high-hydrophilic Cu₂O-TiO₂/Ti₂O₃/TiO coating with nano-morphology on Ti-5Cu was successfully constructed. The corrosion performance results showed that the coating enhanced the corrosion resistance while releasing more Cu²⁺, compared with Ti-5Cu. Antibacterial tests confirmed the perfect antibacterial property of the coating (R ≥ 99.9 %), superior to Ti-Cu alloy (R > 90 %). More delightfully, it was observed by phalloidin-FITC and DAPI staining that the coating improved the early adhesion of HUVEC cells mainly due to strong hydrophilicity and nano-morphology. It was demonstrated that the extract of the coated sample significantly promoted proliferation (RGR = 112 %-138 % after cultivation for 1 to 3 days) and migration of HUVEC cells due to the appropriate Cu²⁺ release concentration. Hemolysis assay and platelet adhesion results showed that the coating had excellent blood compatibility. All results suggested that the coating on Ti-Cu alloy might be a promising surface with the perfect antibacterial ability, blood compatibility and evident promoting endothelialization ability for the cardiovascular application.

Effect of Precipitates on the Mechanical Performance of 7005 Aluminum Alloy Plates

In this study, the strength, elongation, and fatigue properties of 7005 aluminum alloy plates with different configurations of precipitates were investigated by means of tensile tests, fatigue tests, and microstructural observation. We found that the number and size of GP zones in an alloy plate matrix increased and the distribution was more uniform after the aging time was extended from 1 h to 4 h at 120 °C, which led to a rise in both strength and elongation of alloy plates with the extending aging time. The fatigue life of the alloy plates shortened slightly at first, then significantly prolonged, and then shortened again with the aging time extending from 1 h to 192 h and a fatigue stress level of 185 MPa and stress ratio (R) = 0. After aging at 120 °C for 96 h, the precipitates in the alloy plate matrix were almost all metastable η'-phase particles, which had the optimal aging strengthening effect on the alloy matrix, and the degree of mismatch between the α-Al matrix and second-phase particles was the smallest; the fatigue crack initiation and propagation resistances were the largest, leading to the best fatigue performance of alloy plates, and the fatigue life of the aluminum plate was the longest, up to 1.272 × 10⁶ cycles. When the aging time at 120 °C was extended to 192 h, there were a small number of equilibrium η phases in the aluminum plates that were completely incoherent with the matrix and destroyed the continuity of the aluminum matrix, easily causing stress concentration. As a result, the fatigue life of alloy plates was shortened to 9.422 × 10⁵ cycles.

Portevin-Le Chatelier Characterization of Quenched Al-Mg Alloy Sheet with Different Mg Concentrations

In the present study, the PLC characteristic parameters and DSA mechanism of Al-(2.86~9.41) Mg alloy sheets were investigated during tensile testing at room temperature with a tensile rate of 1 × 10⁻³ s⁻¹. On the basis of the solution Mg concentrations in the α-Al matrix, the initial vacancy concentration, the second-phase particle configuration and the recrystallized grain configuration are almost the same by quenching treatment. The results show that the type of room-temperature tensile stress–strain curves of quenched Al-(2.86~9.41) Mg alloy sheets varied according to the Mg content. The type of stress–strain curve of the Al-2.86 Mg alloy sheet was B + C, while the type of stress–strain curve of the Al-(4.23~9.41) Mg alloy sheets was C. When the quenched Al-(2.86~9.41) Mg alloy sheets were stretched at room temperature, the strain cycle of the rectangular waves corresponding to the high stress flow ΔεTmax and stress drop amplitude Δσ on the zigzag stress–strain curve of alloy sheets increased with increasing the Mg content. Moreover, the strain cycle of ΔεTmax and Δσ on the stress–strain curve of alloy sheets increased gradually with increasing tensile deformation. The yield stress of quenched Al-(2.86~9.41) Mg alloy sheets increased gradually with increasing the Mg content. Moreover, the critical strain corresponding to yield stress εσ and the critical strain corresponding to the occurrence of the PLC shearing band εc of alloy sheets both increased with increasing the Mg content. However, the difference in flow strain value Δεc−σ between εc and εσ of alloy sheets decreased gradually with increasing the Mg content.

Yeast culture (Saccharomyces cerevisiae) and its active metabolites affect the cecal microbiome of broilers

Yeast cultures (YCs) are defined as promising feed additives that maintain the health of birds and improve growth performance by modulating gut microbiota. YCs contain effective metabolites such as glycine, fructose, inositol, galactose, and sucrose. This study investigated the effects of YCs and their effective metabolites on carcass traits and cecal microflora in broilers. A total of 280 one-day-old mixed-sex Arbor Acres broilers were randomly allocated to seven groups. The basal diet (control DZ) was supplemented with various proportions of glycine, fructose, inositol, galactose, and sucrose (Groups A, B, and C), 24-hour grown Saccharomyces cerevisiae cultures (Group D) (YC), and a commercial yeast culture product (SZ) at concentrations of 0.1% and 1% (Groups E and F). Bodyweight of broilers was correlated positively with proportions of Proteobacteria in Group C and Lactobacillus and Roseburia in Group B (P <0.05). Broilers fed diets supplemented with YC or its active metabolites had the highest proportions of bacteria involved in nucleotide metabolism, and amino acid and carbohydrate metabolism. These results suggested that the dietary addition of YC could alter the proliferation of beneficial bacteria in broilers.

Effect of Post-Fabricated Aging on Microstructure and Mechanical Properties in Underwater Friction Stir Additive Manufacturing of Al–Zn–Mg–Cu Alloy

The fabricated Al–Zn–Mg–Cu alloy build has low mechanical properties due to the dissolution of strengthening precipitates back into the matrix during friction stir additive manufacturing (FSAM). Post-fabricated aging was considered an effective approach to improve the mechanical performance of the build. In this study, various post-fabricated aging treatments were applied in the underwater FSAM of Al–7.5 Zn–1.85 Mg–1.3 Cu–0.135 Zr alloy. The effect of the post-fabricated aging on the microstructure, microhardness, and local tensile properties of the build was investigated. The results indicated that over-aging occurred in the low hardness zone (LHZ) of the build after artificial aging at 120 °C for 24 h as the high density of grain boundaries, subgrain boundaries, dislocations, and Al₃Zr particles facilitated the precipitation. Low-temperature aging treatment can effectively avoid the over-aging problem. After aging at 100 °C for 48 h, the average microhardness value of the build reached 178 HV; the yield strength of the LHZ and high hardness zone (HHZ) was 453 MPa and 463 MPa, respectively; and the ultimate tensile strength of the LHZ and HHZ increased to 504 MPa and 523 MPa, respectively.

[Evaluation of the effect of comprehensive prevention and management of diabetes mellitus of two cross-sectional surveys based on community population]

To investigate the prevalence of diabetes mellitus (DM) among residents in Chongchuan district, Nantong city in 2012 and 2018, and evaluate the effectiveness of community comprehensive management of DM. Based on the data of 17 780 and 13 382 residents in the cross-sectional surveys of the " National Demonstration Area for Comprehensive Prevention and Control of Chronic Diseases " project in Chongchuan District of Nantong City, Jiangsu Province in 2012 and 2018, 4 583 and 3 996 DM-related information were obtained. The population of Jiangsu Province in 2012 and 2018 was used as the reference for standardization. The rates of prevalence and management (including awareness, treatment, treatment of patients who knew their diabetic situation, control and control of patients under treatment) of DM in the two surveys were compared using chi-square test. The results showed that in 2012 and 2018, the prevalence rates of DM were 12.0% and 15.7% (χ²=24.25, P<0.05), and the standardized rates were 10.1% and 10.8% (χ²=1.05, P=0.306). The incidence rates were 5.7% and 2.3%, respectively (χ²=55.60, P<0.05). The standardized prevalence rates in the two surveys were 9.7% and 11.6% for males (χ²=3.66, P=0.056) and 10.5% and 9.9% for females (χ²=0.50, P=0.481), 7.2% and 6.5% (χ²=0.85, P=0.357) for people aged 18-59 years old and 20.6% and 21.9% (χ²=0.91, P=0.339) for people aged 60 years and over, respectively. The standardized rates of awareness, treatment, treatment of patients who knew their diabetic situation, control, and control of patients under treatment in 2018 were 84.4%, 80.3%, 95.2%, 58.4%, and 70.2%, respectively, higher than 47.2%, 23.4%, 44.8%, 30.4% and 59.4% in 2012 (χ²=183.33, χ²=380.65, χ²=282.99, χ²=93.24, χ²=6.22, all P<0.05). Among men, the standardized rates of awareness, treatment, treatment of patients who knew their diabetic situation, and control in 2018 were 85.8%, 78.8%, 91.8% and 62.7%, higher than 50.5%, 37.5%, 72.3% and 32.6% in 2012 (χ²=78.40, χ²=96.17, χ²=27.55, χ²=48.96, all P<0.05). Similarly, the standardized management rates in 2018 were 83.0%, 81.7%, 98.5%, 54.1% and 65.1%, higher than 44.0%, 10.0%, 18.3%, 28.2% and 48.8% in 2012 among women (χ²=105.52, χ²=326.36, χ²=317.22, χ²=43.34, χ²=3.87, all P<0.05). The standardized rates of awareness, treatment, treatment of patients who knew their diabetic situation, and control of people aged 18-59 and 60 years and over were 82.9%, 79.7%, 96.1%, 55.0% and 88.0%, 81.8%, 93.0% and 67.2%, higher than 42.6%, 19.8%, 42.2%, 27.5% and 63.9%, 36.8%, 53.9%, 40.8% in 2012 (χ²=44.51, χ²=102.17, χ²=57.78, χ²=21.65, all P<0.05; χ²=71.18, χ²=181.55, χ²=146.26, χ²=59.23, all P<0.05). The comprehensive prevention and control system of chronic diseases, which comprehensively covered the life of community residents, had good management effect on DM, and effectively promoted health education and health promotion.

High-entropy-alloy nanoparticles with ultra-mixed 21 elements for efficient photothermal conversion

Multi-metallic nanoparticles have been proven to be an efficient photothermal conversion material, for which the optical absorption can be broadened through the interband transitions (IBTs), but it remains a challenge due to the strong immiscibility among the repelling combinations. Here, assisted by an extremely high evaporation temperature, ultra-fast cooling and vapor-pressure strategy, the arc-discharged plasma method was employed to synthesize ultra-mixed multi-metallic nanoparticles composed of 21 elements (FeCoNiCrYTiVCuAlNbMoTaWZnCdPbBiAgInMnSn), in which the strongly repelling combinations were uniformly distributed. Due to the reinforced lattice distortion effect and excellent IBTs, the nanoparticles can realize an average absorption of >92% in the entire solar spectrum (250 to 2500 nm). In particular, the 21-element nanoparticles achieve a considerably high solar steam efficiency of nearly 99% under one solar irradiation, with a water evaporation rate of 2.42 kg m^–2 h^–1, demonstrating a highly efficient photothermal conversion performance. The present approach creates a new strategy for uniformly mixing multi-metallic elements for exploring their unknown properties and various applications.

A novel Ti-Au alloy with strong antibacterial properties and excellent biocompatibility for biomedical application

In order to avoid the toxic and side effects on human body of long-term dissolution of metal ions from antibacterial titanium alloys, Au element with non-toxicity and non-side effect was selected as the alloying element to prepare a new Ti-Au alloy with strong antibacterial property. We produced Ti-Au(S) sintered alloy by powder metallurgy and Ti-Au ingot alloy by ingot metallurgy, and investigated the influence of the secondary phase on the relative antimicrobial properties and antibacterial mechanism in this work. The results indicated that the aged Ti-Au(T6) alloy and Ti-Au(S) sintered alloy exhibited strong antibacterial rate against S. aureus due to the formation of Ti₃Au phases. In vitro cell culture (MC3T3 cells) experiments showed that Ti-Au alloys had good cytocompatibility and osteogenic properties. The following viewpoints of antibacterial mechanism are that the Ti₃Au destroyed the ROS homeostasis of bacteria, causing oxidative stress in bacterial cells and preventing from the biofilms formation.

Quinary High-Entropy-Alloy@Graphite Nanocapsules with Tunable Interfacial Impedance Matching for Optimizing Microwave Absorption

Designing heterogeneous interfaces and components at the nanoscale is proven effective for optimizing electromagnetic wave absorption and shielding properties, which can achieve desirable dielectric polarization and ferromagnetic resonances. However, it remains a challenge for the precise control of components and microstructures via an efficient synthesis approach. Here, the arc-discharged plasma method is proposed to synthesize core@shell structural high-entropy-alloy@graphite nanocapsules (HEA@C-NPs), in which the HEA nanoparticles are in situ encapsulated within a few layers of graphite through the decomposition of methane. In particular, the HEA cores can be designed via combinations of various transition elements, presenting the optimized interfacial impedance matching. As an example, the FeCoNiTiMn HEA@C-NPs obtain the minimum reflection loss (RL_min ) of -33.4 dB at 7.0 GHz (3.34 mm) and the efficient absorption bandwidth (≤-10 dB) of 5.45 GHz ranging from 12.55 to 18.00 GHz with an absorber thickness of 1.9 mm. The present approach can be extended to other carbon-coated complex components systems for various applications.

Twin Boundary Superstructures Assembled by Periodic Segregation of Solute Atoms

Twinning is a common deformation mechanism in metals, and twin boundary (TB) segregation of impurities/solutes plays an important role in the performances of alloys such as thermostability, mobility, and even strengthening. The occurrence of such segregation phenomena is generally believed as a one-layer coverage of solutes alternately distributed at extension/compression sites, in an orderly, continuous manner. However, in the Mn-free and Mn-containing Mg-Nd model systems, we reported unexpected three- and five-layered discontinuous segregation patterns of the coherent {101̅1} TBs, and not all the extension sites occupied by solutes larger in size than Mg, and even some larger sized solutes taking the compression sites. Nd/Mn solutes selectively segregate at substitutional sites and thus to generate two new types of ordered two-dimensional TB superstructures or complexions. These findings refresh the understanding of solute segregation in the perfect coherent TBs and provide a meaningful theoretical guidance for designing materials via targeted TB segregation.

[Comparison of three kinds of free flaps used in patients with oral and oropharyngeal tumors]

Objective: To compare the recovery and quality of life of patients with oral and oropharyngeal tumors treated with three kinds of free soft tissue flaps. Methods: The clinical data of 103 patients, including 66 males and 37 females, aged 26-74 years, who underwent primary repair of defects after resection of oral and oropharyngeal tumors in Sichuan Tumor Hospital from July 2014 to August 2020 were analyzed. Anterolateral thigh flap (ALTF) was used in 43 patients, radial forearm free flap (RFFF) in 45 patients, and lateral arm free flap (LAFF) in 15 patients. Postoperative qualities of life of patients were evaluated by the university of Washington quality of life questionnaire and oral health impact scale (HIP-14 Chinese edition). SPSS 23.0 software was used for statistical analysis. Results: The T staging of RFFF or LAFF group was significantly lower than that of ALTF group (P<0.05). There was no significant difference in mean flap areas between ALTF group ((55.87±27.38) cm²) and LAFF group ((49.93±19.44) cm²), while RFFF group had smaller mean flap area ((33.18±6.05) cm²) than ALTF group (t=5.311, P<0.001) and LAFF group (t=3.284, P=0.005). In terms of oral functions including swallowing, mastication, taste and spitmouth, there were no significant differences between LAFF group and RFFF group (P>0.05), but both groups had better oral functions than ALTF group (P<0.05). There was no significant difference in appearance scores between LAFF group (75(75, 75)) and ALTF group (75(75,75) vs.75(75,75),Z=-1.532, P=0.126), and both groups had higher scores than RFFF group (50(50, 75),Z values were -3.447 and -3.005 respectively, P<0.05). RFFF group had higher speech score (100(67, 100)) than LAFF group (67(50, 76),Z=-2.480, P<0.05) and ALTF group (67(33, 67),Z=-5.414, P<0.05). ALTF group had lower mean score of quality of life than RFFF group [72(56,77) vs.79(69, 89),Z=-3.070, P<0.05), but there was no statistical difference in the mean scores of qualities of life between ALTF group and LAFF group (Z=1.754, P=0.079). According to the evaluation of oral health impact scale (HIP-14 Chinese version) 1 year after surgery, individual item scores and the average score of all items in ALTF group were lower than those in RFFF and LAFF groups (P<0.05), with no significant difference between RFFF group and LAFF group (P>0.05). Conclusions: RFFF has unique advantages for small tissue defects, while ALTF is suitable for large tissue defects, such as buccal penetrating defect, whole tongue and near whole tongue defect, and LAFF is a compromise choice between ALTF and RFFF. ALTF is inferior to RFFF and LAFF in oral functional reconstruction, including swallowing, chewing, taste and spittle. ALTF and LAFF are superior to RFFF in postoperative appearance.

Sulfur-doped wood-derived porous carbon for optimizing electromagnetic response performance

Bio-mass materials have been selected as one of the advanced electromagnetic (EM) functional materials due to their natural porous framework for dynamically and flexibly optimizing the EM response property. Herein, we demonstrate sulfur-doped wood-derived porous carbon EM materials (SPC) for optimizing the EM response performance via the coupling between doped heterostructures and the original 3D microchannels. The experimental results reveal that both the dielectric loss capacity and interfacial impedance matching could be increased by the sulfur-doped heterostructures. By tailoring the sulfur content, the microwave absorption (normalized RL_min) of SPC could be optimized to -15.90 dB mm^-1, while the effective absorption bandwidth (EAB_{RL≤-10 dB}) could cover the K band. Moreover, the shielding effectiveness of SPC can be enhanced from 10 dB to 30 dB with the assistance of water, ascribed to the super-wettability performance. This present study provides a novel strategy to further optimize the EM response performance of wood-derived materials, and meanwhile could be widely extended to other bio-mass absorbers.

Enhanced resistive switching performance in yttrium-doped CH3NH3PbI3 perovskite devices

In this study, yttrium-doped CH₃NH₃PbI₃ (Y-MAPbI₃) and pure CH₃NH₃PbI₃ (MAPbI₃) perovskite films have been fabricated using a one-step solution spin coating method in a glove box. X-ray diffractometry and field-emission scanning electron microscopy were used to characterize the crystal structures and morphologies of perovskite films, respectively. It was found that the orientation of the crystal changed and the grains became more uniform in Y-MAPbI₃ film, compared with the pure MAPbI₃ perovskite film. The films were used to prepare the resistive switching memory devices with the device structure of Al/Y-MAPbI₃ (MAPbI₃)/ITO-glass. The memory performance of both devices was studied and showed a bipolar resistive switching behavior. The Al/MAPbI₃/ITO device had an endurance of about 328 cycles. In contrast, the Al/Y-MAPbI₃/ITO device exhibited an enhanced performance with a long endurance up to 3000 cycles. Moreover, the Al/Y-MAPbI₃/ITO device also showed a higher ON/OFF ratio of over 10³, long retention time (≥10⁴ s), lower operation voltage (±0.5 V) and outstanding reproducibility. Additionally, the conduction mechanism of the high resistance state transformed from space-charge limited current for a Y free device to the Schottky emission after Y doping. The present results indicate that the Al/Y-MAPbI₃/ITO device has a great potential to be used in high-performance memory devices.

High-Entropy-Alloy Nanoparticles with Enhanced Interband Transitions for Efficient Photothermal Conversion

Photothermal materials with broadband optical absorption and high conversion efficiency are intensively pursued to date. Here, proposing by the d-d interband transitions, we report an unprecedented high-entropy alloy FeCoNiTiVCrCu nanoparticles that the energy regions below and above the Fermi level (±4 eV) have been fully filled by the 3d transition metals, which realizes an average absorbance greater than 96 % in the entire solar spectrum (wavelength of 250 to 2500 nm). Furthermore, we also calculated the photothermal conversion efficiency and the evaporation rate towards the steam generation. Due to its pronounced full light capture and ultrafast local heating, our high-entropy-alloy nanoparticle-based solar steam generator has over 98 % efficiency under one sun irradiation, meanwhile enabling a high evaporation rate of 2.26 kg m^-2  h^-1 .

Effects of feed with different protein digestion kinetic profiles on intestinal health of growing pigs

This study evaluated the effects of feed ingredients with different protein digestion kinetic profiles on the intestinal health of growing pigs. Two protein sources were selected, namely casein (CAS) as a rapid release source of amino acids (AAs), and corn gluten meal (CGM) as a slow-release source. Twenty-four crossbred barrows (Duroc × Landrace × Yorkshire) with similar bodyweight (43.27 ± 3.51 kg) were selected and randomly assigned to four treatments with six barrows. These consisted of T1: 13.2% digestible crude protein (CP) with supplemental CAS; T2: 13.2% digestible CP with supplemental CGM; T3: 11.2% digestible CP with supplemental CAS (T3); and T4: 11.2% digestible CP with supplemental CGM. Diets with CGM had increased crypt depth in the duodenum, jejunum, and ileum and reduced villi height in the jejunum in comparison with CAS. They also had increased intestinal permeability, as seen by the high level of serum diamine oxidase (DAO) compared with CAS. The diets with CAS increased health-promoting Lactobacillus and decreased health-threatening Treponema compared with those fed CGM diets. The CAS diets had a positive effect on gut functions with increased villi height, decreased crypt depth and high villi height/crypt depth. Thus, use of CAS in diets for pigs is favoured over CGM.

Two-Dimensional Frank-Kasper Z Phase with One Unit-Cell Thickness

Z phase is one of the three basic units by which the Frank-Kasper (F-K) phases are generally assembled. Compared to the other two basic units, that is, A₁₅ and C₁₅ structures, the Z structure is rarely experimentally observed because of a relatively large volume ratio among the constituents to inhibit its formation. Moreover, the discovered Z structures are generally the three-dimensional ordered Gibbs bulk phases to conform to their thermodynamic stability. Here, we confirmed the existence of a metastable two-dimensional F-K Z phase that has only one unit-cell height in the crystallography in a model Mg-Sm-Zn system, using atomic-scale scanning transmission electron microscopy combined with the first-principles calculations. Self-adapted atomic shuffling can convert the simple hexagonal close-packed structure to the topologically close-packed F-K Z phase. This finding provides new insight into understanding the formation mechanism and clustering behavior of the F-K phases and even quasicrystals in general condensed matters.

Full-Electrical Writing and Reading of Magnetization States in a Magnetic Junction with Symmetrical Structure and Antiparallel Magnetic Configuration

Full-electrical writing and reading of magnetization states are vital for the development of next-generation spintronic devices with high density and ultralow-power consumption. Here, we proposed a method to realize the full-electrical writing and reading of magnetization states via a structural design, which only requires a symmetrical device structure and an antiparallel magnetic configuration. CrBr₃, h-BN, and 1T-MnSe₂ were selected to construct the device of CrBr₃/h-BN/1T-MnSe₂/h-BN/CrBr₃, where the magnetization of two CrBr₃ layers was fixed to the antiparallel state. By changing the direction and magnitude of the applied electric field, it is proved that the magnetization of 1T-MnSe₂ could be reversed. Moreover, the device energies before and after the magnetization reversal are the same when the applied electric field is removed due to the structural symmetry. Meanwhile, the magnetic anisotropy energy of 1T-MnSe₂ could induce an energy barrier, to guarantee the nonvolatile magnetization reversal in the present device. In addition, the tunnel magnetoresistance ratio was found up to 421%, showing a promising application to full-electrically write and read magnetization in spintronics. The present study likely promotes the development of full-electrical and ultralow-power spintronics devices.

The osteoimmunomodulatory effect of nanostructured TiFx/TiOxcoating on osteogenesis induction

Macrophages play a central role in the host response and the integration of implant materials. The nanostructured TiF_x/TiO_xcoating (FOTi) on titanium surfaces has shown multiple properties, including antibacterial properties and bioactivity. However, little is known about the effects of these coatings on the regulation of macrophage activity and the subsequent immunomodulatory effects on osteogenesis. In this study, the behavior of macrophages on the FOTi samples was evaluated, and conditioned medium was collected and used to stimulate MC3T3-E1 cellsin vitro. The results showed that the FOTi samples stimulated macrophage elongation and promoted the production of proinflammatory cytokines at 24 h, while induced macrophage polarization to the anti-inflammatory M2 phenotype at 72 h. Furthermore, the immune microenvironment generated by macrophage/ FOTi samples interactions effectively promoted the osteogenic differentiation of MC3T3-E1 cells, as evidenced by improved cell adhesion, enhanced alkaline phosphatase activity and extracellular matrix mineralization, and upregulated osteogenesis-related gene expression. In summary, the FOTi samples mediated macrophage phenotype behaviors and induced beneficial immunomodulatory effects on osteogenesis, which could be a potential strategy for the surface modification of bone biomaterials.

MiR-21-5p in macrophage-derived extracellular vesicles affects podocyte pyroptosis in diabetic nephropathy by regulating A20

OBJECTIVES

Podocyte pyroptosis, characterized by inflammasome activation, plays an important role in inflammation-mediated diabetic nephropathy (DN). Our study aimed to investigate whether miR-21-5p in macrophage-derived extracellular vesicles (EVs) could affect podocyte injury in DN.

METHODS

EVs were extracted after the treatment of RAW 264.7 (mouse macrophage line) with high glucose (HG). The podocyte pyroptosis was determined using the flow cytometry and the western blot. After the knockdown of miR-21-5p in HG-induced RAW264.7 cells, we injected the extracted EVs into DN model mice.

RESULTS

The level of miR-21-5p was higher in HG-stimulated macrophage-derived EVs than in normal glucose-cultured macrophage-derived EVs. The co-culture of EVs and podocytes promoted reactive oxygen species (ROS) production and activation of inflammatory in MPC5 cells (mouse podocyte line). However, restraint of miR-21-5p in EVs reduced ROS production and inhibit inflammasome activation in MPC5 cells, thereby reducing podocytes injury. Meanwhile, we found that miR-21-5p inhibited the A20 expression through binding with its 3'-untranslated regions in MPC5 cells. Further studies showed that A20 was also involved in the regulation of miR-21-5p of RAW 264.7-derived EVs on MPC5 injury. At the same time, it was also proved in the DN model mice that miR-21-5p in macrophage-derived EVs could regulate podocyte injury.

CONCLUSION

MiR-21-5p in macrophage-derived EVs can regulate pyroptosis-mediated podocyte injury by A20 in DN.

Development of a low elastic modulus and antibacterial Ti-13Nb-13Zr-5Cu titanium alloy by microstructure controlling

In order to prepare a titanium with a low elastic modulus and good antibacterial property to meet the requirements as a biomedical material, Ti-13Nb-13Zr-5Cu (TNZ-5Cu) alloy was prepared by high vacuum consume electric arc melting furnace and then subjected to a solution treatment at 950 °C followed by a short-term aging treatment at 600 °C, for 15 min, 30 min, 1 h and 2 h, respectively. The microstructure, mechanical property, antibacterial property and biocompatibility of TNZ-5Cu were investigated in detail. The research results have shown that the solid solution treated alloy was mainly composed of β-phase and α″-phase, while the aged alloys of β-phase, α″-phase, α-phase and Ti₂Cu. Compared with Ti-13Nb-13Zr alloy (65 GPa) and Ti-6Al-4 V alloy (111 GPa), the elastic modulus of TNZ-5Cu alloy after solution treatment was about 72 GPa and increased with the aging treatment up to 85 GPa, and the hardness was maintained at a higher level than that of Ti-13Nb-13Zr alloys (288 HV). The bacteria plate count results showed that the antibacterial ability of TNZ-5Cu alloy increased with the extension of the aging duration from <60% at 15-30 min to >90% at 1-2 h. Cell experiments showed that all TNZ-5Cu alloy had good cell compatibility. The low modulus and the antibacterial property could provide potential to avoid stress shield and device-related inflection in the clinical application.

Nonsymmetrical Segregation of Solutes in Periodic Misfit Dislocations Separated Tilt Grain Boundaries

Interfacial segregation is ubiquitous in mulit-component polycrystalline materials and plays a decisive role in material properties. So far, the discovered solute segregation patterns at special high-symmetry interfaces are usually located at the boundary lines or are distributed symmetrically at the boundaries. Here, in a model Mg-Nd-Mn alloy, we confirm that elastic strain minimization facilitated nonsymmetrical segregation of solutes in four types of linear tilt grain boundaries (TGBs) to generate ordered interfacial superstructures. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy observations indicate that the solutes selectively segregate at substitutional sites at the linear TGBs separated by periodic misfit dislocations to form such two-dimensional planar structures. These findings are totally different from the classical McLean-type segregation which has assumed the monolayer or submonolayer coverage of a grain boundary and refresh understanding on strain-driven interface segregation behaviors.

Antibacterial metals and alloys for potential biomedical implants

Metals and alloys, including stainless steel, titanium and its alloys, cobalt alloys, and other metals and alloys have been widely used clinically as implant materials, but implant-related infection or inflammation is still one of the main causes of implantation failure. The bacterial infection or inflammation that seriously threatens human health has already become a worldwide complaint. Antibacterial metals and alloys recently have attracted wide attention for their long-term stable antibacterial ability, good mechanical properties and good biocompatibility in vitro and in vivo. In this review, common antibacterial alloying elements, antibacterial standards and testing methods were introduced. Recent developments in the design and manufacturing of antibacterial metal alloys containing various antibacterial agents were described in detail, including antibacterial stainless steel, antibacterial titanium alloy, antibacterial zinc and alloy, antibacterial magnesium and alloy, antibacterial cobalt alloy, and other antibacterial metals and alloys. Researches on the antibacterial properties, mechanical properties, corrosion resistance and biocompatibility of antibacterial metals and alloys have been summarized in detail for the first time. It is hoped that this review could help researchers understand the development of antibacterial alloys in a timely manner, thereby could promote the development of antibacterial metal alloys and the clinical application.

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This paper focuses the recent development of several antibacterial metals and alloys as biomedical materials.

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The possible antibacterial mechanisms of antibacterial metals and alloys are summarized in this paper.

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This review discusses the feasibility of antibacterial metals and alloys as biomedical implants in the future.

Position selective dielectric polarization enhancement in CNT based heterostructures for highly efficient microwave absorption

Constructing carbon nanotube (CNT) based heterostructures has proven to be an effective way of improving the microwave absorption (MA) capability of these materials, regardless of whether the heterostructures are located on the inner or outer walls of the CNTs. However, the potential of the two sides of CNTs for constructing efficient MA heterostructures has not been compared, and the underlying mechanism behind this difference has not been determined. Therefore, CNT based heterostructures with Fe2O3 nanoparticles inside (Fe2O3-in-CNTs) and outside (Fe2O3-out-CNTs) of the CNTs were synthesized and characterized. The minimum reflection loss and maximum effective bandwidth of the Fe2O3-in-CNTs are -34.1 dB at 3.0 mm and 5.1 GHz at 2.6 mm, much better than those of the Fe2O3-out-CNTs. Stronger interfacial polarization at the inner surface of the CNTs than at the outer surface was confirmed using off-axis electron holography, which is regarded as the key factor that determines the excellent MA performance of the heterointerface constructed by the inner surface of the CNTs. The attractive potential of the inner surface of CNTs for constructing highly efficient MA heterostructures has, to our knowledge, not been proposed before, the findings of which can shed the light on the approach of developing CNT composited MA materials that have outstanding MA properties.

Magnesium in Combinatorial With Valproic Acid Suppressed the Proliferation and Migration of Human Bladder Cancer Cells

Magnesium, the second most predominant intracellular cation, plays a crucial role in many physiological functions; magnesium-based biomaterials have been widely used in clinical application. In a variety of cancer types, the high intracellular concentration of magnesium contributes to cancer initiation and progression. Therefore, we initiated this study to investigate the likelihood of confounding magnesium with cancer therapy. In this study, the anti-tumor activity of magnesium and underlying mechanisms were assessed in bladder cancer both in vitro and in vivo. The results indicated that the proliferation of bladder cancer cells was inhibited by treatment with a high concentration of MgCl₂ or MgSO₄. The apoptosis, G0/G1 cell cycle arrest, autophagy, and ER stress were promoted following treatment with MgCl₂. However, the migratory ability of MgCl₂ treated cells was similar to that of control cells, as revealed by the trans-well assay. Besides, no significant difference was observed in the proportion of CD44 or CD133 positive cells between the control and MgCl₂ treated cells. Thus, to improve the therapeutic effect of magnesium, VPA was used to treat cancer cells in combination with MgCl₂. As expected, combination treatment with MgCl₂ and VPA could markedly reduce proliferation, migration, and in vivo tumorigenicity of UC3 cells. Moreover, the Wnt signaling was down-regulated, and ERK signaling was activated in the cells treated with combination treatment. In conclusion, the accurate utilization of MgCl₂ in targeting autophagy might be beneficial in cancer therapy. Although further studies are warranted, the combination treatment of MgCl₂ with VPA is an effective strategy to improve the outcome of chemotherapy.

Mechanical performance and biocompatibility assessment of Zn-0.05wt%Mg-(0.5, 1 wt%) Ag alloys

Zn alloys are emerging as promising degradable biomedical materials due to their tailorable mechanical properties and moderate biodegradable rate, compared with conventional biodegradable metallic materials. Ag, as an effective antibacterial and reinforcing element, was incorporated into Zn-0.05Mg alloys. In the present work, the effects of the Ag addition on mechanical, cytotoxic, hemolytic, pyrogenic, histological behaviors of the animal were investigated. The compressive yielding strength is enhanced from 198 MPa for Zn-0.05Mg alloy up to 224 and 234 MPa for Zn-0.05Mg-0.5Ag and Zn-0.05Mg-1Ag alloys, respectively. When the compressive strain was 65%, the strength of the Zn-0.05Mg-1.0Ag alloy reached 833 MPa, which was much higher than that of 721 MPa for Zn-0.05Mg alloy. The relative growth rate (RGR) for the extracts of Zn-0.05Mg-1Ag alloy with the concentrations of 10, 50, and 100% after 5 days incubation reaches 98.5, 95.2, and 94.2%, which are higher than those in extracts of Zn-0.05Mg-0.5Ag alloy (98.2, 93.9, 92.1%). The hemolysis rate of the Zn-0.05Mg alloys with 0.5 and 1 wt% Ag is 2.46 and 2.28%, respectively. The variations of body weight and temperature, postinjection symptoms, pathological morphologies of the visceral organs demonstrate that the alloys are nontoxic according to the toxicity rating standards. Zn-0.05wt%Mg-(0.5, 1 wt%) Ag alloys are experimentally safe materials and promising for the future application as biodegradable medical devices.

Gender and age differences in the association between sleep characteristics and fasting glucose levels in Chinese adults

AIM

The present study examined the associations between night-time sleep duration, midday napping duration and bedtime, and fasting glucose levels, and whether or not such associations are dependent on gender and age.

METHODS

This study was a cross-sectional analysis of 172,901 adults aged≥40 years living in mainland China. Sleep duration was obtained by self-reports of bedtime at night, waking-up time the next morning and average napping duration at midday. Fasting plasma glucose (FPG)≥7.0mmol/L was defined as hyperglycaemia. Independent associations between night-time sleep duration, midday naptime duration and bedtime with hyperglycaemia were evaluated using regression models.

RESULTS

Compared with night-time sleep durations of 6-7.9h, both short (<6h) and long (≥8h) night-time sleep durations were significantly associated with an increased risk of hyperglycaemia in women [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.29 and OR: 1.14, 95% CI: 1.08-1.21, respectively], and revealed a U-shaped distribution of risk in women and no significant association in men. Long midday nap durations (≥1h) were significantly but weakly associated with hyperglycaemia (OR: 1.04, 95% CI: 1.01-1.09) compared with no napping without interactions from gender or age, whereas the association between bedtime and fasting glucose levels did vary according to gender and age.

CONCLUSION

Night-time sleep duration, midday napping duration and bedtime were all independently associated with the risk of hyperglycaemia, and some of the associations between these sleep characteristics and hyperglycaemia were gender- and age-dependent.

Synergistic effects of dopant (Ti or Sn) and oxygen vacancy on the electronic properties of hematite: a DFT investigation

Hematite has been widely studied as one of the most promising photoanodes in the photoelectrochemical decomposition of water. At present, a prevailing strategy of coupling dopant (Ti or Sn) with oxygen vacancies has been proposed by experiment, and effectively improves the photocatalytic activity. In order to clarify the intrinsic reasons for the improvement of the photochemical activity, density functional theory is adopted to calculate the formation mechanism and electronic properties of hematite with doping ions and oxygen vacancies. The result shows that the doped atom is beneficial to the formation of oxygen vacancies in hematite, thus forming a stable structure containing doping ions and oxygen vacancies. Due to the synergistic effects of dopant and oxygen vacancies, the bandgap of hematite decreases, and donor levels are introduced into the bandgap, which lead to the increase of carrier concentration. In the system with doped Ti and oxygen vacancies, donor levels are introduced at 1.47 eV and 1.73 eV below the bottom of the conduction band, respectively. For the case containing Sn and oxygen vacancies, the donor level is introduced at 1.75 eV from the conduction band minimum. Our results elaborate the reasons for the enhancement of carrier densities in terms of electronic structure, and provide some guidance for the future modification of photocatalysts.

Hematite has been widely studied as one of the most promising photoanodes in the photoelectrochemical decomposition of water.