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Rapid and sensitive quantification of pathogenic bacteria is highly desired for environmental health supervision and food safety control. Yet, the amplification and detection of bacteria with a concentration lower than 10

LZ7C3 fibres with nanostructures have been synthesised by the sol–gel method combined with electrostatic spinning technology and a high-temperature-resistant LZ7C3 ceramic material prepared by high...

Summary Purpose The aim of this study was to determine whether the neutrophil to lymphocyte ratio (NLR) can predict severe Coronavirus disease 2019 (COVID-19). Patients and methods A multicenter case-control study was conducted to investigate whether the NLR can help predict the severity of COVID-19. Patients confirmed to have COVID-19 between 16 January 2020 and 15 March 2020 were enrolled. Furthermore, meta-analyses were conducted based on both previous studies and our case-control study. Results In the case-control study, 213 patients (severe: 81) were included. The results suggested that the NLR was an independent risk factor (odds ratio [OR], 1.155, 95% confidence interval [95% CI]: 1.043–1.279, P = 0.006) and a great predictor (the area under the ROC curve was 0.728, 95% CI: 0.656–0.800) for severe COVID-19. In total, 18 datasets from 16 studies combined with our case-control study (severe: 1211; non-severe: 5838) were included in the meta-analyses and the results showed that the NLR of the severe COVID-19 group was significantly higher than that of the non-severe group (SMD = 1.10, 95% CI: 0.90–1.31, P Conclusion Based on a multicenter case-control study and a meta-analysis, we found that the initial NLR was a great predictor of severe COVID-19.

The aim of this work is to study the effect of solution treatment time on the Ti2Ni second phase morphology, phase transformations, mechanical properties and superelastic behavior of plasma arc deposited (PAD) nitinols. The results demonstrate that the Ti2Ni second phases are significantly affected by the solution treatment time. The Ti2Ni second phase is dissolved into the TiNi matrix phase gradually, and its size and volume fraction also gradually decreases with increasing solution treatment time. Additionally, the solution treatment time exhibits a visible influence on the phase transformation, mechanical properties and superelasticity of the PAD nitinol, but the degree of influence depends on the size, volume fraction and distribution of the Ti2Ni second phase. With increasing solution treatment time, the phase transformation temperatures gradually increase, and the phase transformation peaks decrease in width and become sharp with a single transformation. Besides, the compressive strength first increases and then decreases, while the plasticity increases with solution treatment time increases from 0 to 8 h. Moreover, the superelastic stability of the PAD nitinol is improves as the solution treatment time increases from 0 to 6 h and then decreases. This phenomenon is closely related to the critical stress for dislocation slip, which depends on the change in the Ti2Ni second phase.

A highly ordered surface enhanced Raman spectroscopy substrate based on TiO2-Ag nanotubes was prepared using simple and rapid electrochemical method. Its enhancement factor was measured up to 1.5 × 109 using rhodamine 6G probe.

The aim of this study was to explore the effect of pelvic floor muscle training as an adjunct for prolapse surgery. Participants were randomly allocated into 2 groups receiving lifestyle advice (n = 48) and lifestyle advice + pelvic floor muscle training (n = 49). This study compared the total score (Pelvic Floor Distress Inventory-20) and the scores of the Urinary Distress Inventory-6/Colorectal Anal Distress Inventory-8/Pelvic Organ Prolapse Distress Inventory-6 at admission, discharge, and 42 and 60 days after surgery. The UDI-6 score in the lifestyle advice + pelvic floor muscle training group was lower than that in the lifestyle advice group 42 and 60 days after surgery. Pelvic floor muscle training can improve the bladder-related symptoms to have positive significance for pelvic floor rehabilitation after pelvic organ prolapse surgery.

Today, many researchers focus on the destructive effects of the laser in underwater environment. In this paper, we present underwater wet laser repairing which is a kind of technique to avert the destructive effects of the interactions between laser, water and target. We introduce helpful materials to repair nickel aluminum bronze (NAB) plate and discuss the effect of interactions between the laser, water and target on the repairing quality during underwater wet laser repairing process. As a result, the useful materials, Zn and Ti, protect melting pool from damaging by the high-speed water jet and shock wave. The as-repaired layers possess good repairing quality. In addition, the as-repaired layer manufactured by underwater wet laser repairing process possesses smaller heat affected zone, smaller coating thickness and more deformation than the layer manufactured in the air. In summary, with the help of the useful materials, a good repairing quality can be obtained.

The requirement of repairing damaged surface of nickel aluminum bronze (NAB) parts from underwater environment is urgent in recent years. In this paper, a novel approach to underwater laser cladded NAB by adding Ti and applying Zn protective layer has been reported. The materials fabricated underwater from this approach possess desirable performance. Ti additives increases the surface tension in melting pool, and prevents the high-speed water jet from invading the melting pool. Therefore, pores are almost disappearing. Due to the fast heat loss during underwater laser cladding process, the microstructure of underwater laser cladded nickel aluminum with adding titanium is fine, homogeneous and stable, in addition, the heat affected zone is small. Electrochemical results shows that the corrosion resistance of underwater laser cladded nickel aluminum bronze with adding titanium is better than that of substrate. In this study, the underwater environment is favorable for manufacturing a good material by using laser processing technology. The results of this study will provide meaningful reference to repairing NAB parts in underwater environment.

To investigate the clinical practice of Chinese respiratory therapists (RTs) participating in the treatment of coronavirus disease 2019 (COVID-19) patients and summarize the experience and role of RTs in the treatment of pandemic infectious diseases.A self-designed questionnaire was used to investigate the RTs who treated COVID-19 patients in 31 provinces, cities and autonomous regions in China. The survey questionnaire included the basic work of RTs, the specific work of the treatment for COVID-19 patients and problems encountered at work.A total of 126 questionnaires were issued and 40 valid questionnaires were collected from RTs who treated COVID-19 patients at 22 COVID-19 designated hospitals in 8 provinces and municipalities. This included 7 hospitals in Wuhan, the epicenter of the epidemic. In their medical team, RTs accounted for 2.9% (1.5%, 6.7%) of medical staff, the working experience of the RTs was about (6.2±5.4) years, the ratio of RTs to beds was about 1:11 (1:5, 1:26), and 85.0% (34/40) of RTs were transferred from other hospitals. 97.5% (39/40) of RTs were involved in formulating individual respiratory care strategies in their medical teams, and they were all involved in the evaluation of respiratory care and decision-making as well as the early identification of deterioration of respiratory function. All RTs [100% (40/40)] indicated that they would actively monitor patients' respiratory status, increase the means and frequency of the monitoring, implement standardized oxygen therapy, prevent ventilator-associated lung injury (VALI), and standardize the management of artificial airway. However, less than 50% of RTs had carried out stress and strain, transpulmonary pressure, partial pressure of end-tidal carbon dioxide (PetCORTs performed their professional role fully in the assessment, decision-making, and clinical practice in the treatment of COVID-19 patients. However, the manpower shortage of RTs is extremely prominent, the practical experience has provided the basis for the future treatment of infectious respiratory diseases and effectively promoted the development of respiratory care in China.

Background Acute kidney injury (AKI) is a serve and harmful syndrome in the intensive care unit. Our previous study has shown that patients who will progress to AKI 3 stage are considered to receive RRT. This study aimed to develop a prediction model that can predict whether progression to AKI stage 3. Methods Patients with AKI stage 1/2, when they were first diagnosed with AKI in the Medical Information Mart for Intensive Care (MIMIC-III), were included. Patients who receive RRT or progress to AKI 3 stage within 72 hours of first AKI diagnosis were excluded. We build two predictive models, respectively using machine learning extreme gradient boosting (XGBoost) and logistic regression, to predict patients who will progress to AKI stage 3. Established models were evaluated by cross-validation and area under receiver operating characteristic curve (AU-ROC). Results Of the 29238 patients included in the analysis, 3237 (11.1%) patients progressed to AKI stage 3. Creatinine, blood urea nitrogen (BUN), sepsis and respiratory failure were the important predictors of AKI progression. The machine learning XGBoost model has a better performance than the Cox regression model on predicting AKI stage 3 progression (AU-ROC, 0.860 vs. 0.728, respectively). Conclusions The XGBoost model was able to identify patients with AKI progression better than the Cox regression model. Machine learning techniques may improve predictive modeling in medical research.

In order to obtain metallurgical shape memory alloy with a better quality, electro-magnetic stirring (EMS) technology is selected as an aiding method during plasma arc deposition (PAD) process. In this work, Ti51Ni49 alloys were successfully produced by EMS-assisted PAD technology. Influence of EMS on the microstructure, phase transformation behavior, micro-hardness and wear resistance of PAD TiNi alloy have been systematically investigated. The PAD TiNi alloy is composed of TiNi coarse columnar dendrites with a certain number of Ti2Ni phases distributed in the inter-dendritic regions. Under the action of EMS, TiNi coarse columnar dendrites transform into fine non-dendrites or spheroid grains and the homogeneity of microstructures improves significantly. The implementation of EMS during PAD do not change the path of phase transformation, but improve the degree of phase transformations and reduce the transformation temperatures of PAD TiNi alloy. The EMS-PAD TiNi alloy possesses better dry wear resistance than the PAD TiNi alloy, which can be attributed to the higher degree of pseudo-elasticity of TiNi phases and strengthening of Ti2Ni phases.

Recently, additive manufacturing (AM) technology has drawn significant attention to fabricate shape memory alloys. In this study, plasma arc deposition (PAD), an AM technology, has been successfully applied to prepare the Ti51Ni49 alloy directly and rapidly at the first time. The synthesized PAD Ti51Ni49 alloy consisting of TiNi (B2), TiNi (B19′) and Ti2Ni phase, exhibited primary TiNi columnar dendrites structure with a certain number of Ti2Ni phases distributed in the interdendritic regions. The as-deposited Ti51Ni49 alloy displayed a two-step phase transformation evidently (B2→ R → B19’) during cooling process, and special linear superelasticity (up to 4.5%) with narrow hysteresis due to Ti2Ni phase embedded in TiNi matrix phase. This work suggests that the PAD is an effective technology to directly and rapidly synthesize shape memory alloy.

Recently, additive manufacturing have gradually become an attractive processing technology for TiNi alloy. In this work, the Ti50Ni50 alloy was successfully prepared by plasma arc deposition (PAD) technology. The microstructures, phase transformation characteristics and mechanical properties were investigated in detail. The PAD-TiNi alloy mainly comprised of TiNi (B2), TiNi (B19’) and Ti2Ni phases. The TiNi cellular crystals, TiNi dendrite crystals and TiNi equiaxed crystals were presented at the bottom, middle and top area of PAD-TiNi alloys, respectively. Some irregular Ti2Ni phases were distributed in the inter-dendritic areas. The peritectic reaction of L (Ti) + TiNi →Ti2Ni led to the formation of irregular Ti2Ni phases. The coherence of Ti2Ni phases and TiNi matrix phases drove the two-step phase transformation (B2→ R → B19’) during the cooling process. The as-deposited samples showed favorable hardness and high strength, especially possessing special quasi-linear superelasticity (up to 3.8%) with narrow hysteresis, which was derived from the quick appearance and disappearance of deformation microtwins under loading and unloading condition. The newly formed interface between Ti2Ni precipitates and TiNi matrix phase offered the nucleation sites for deformation microtwins and promoted the formation of microtwins.

The metastable materials have attracted the attention of researchers due to their promising physicochemical properties, but the thermal stability limits their practical application. In this paper, Ni-B/La2O3 amorphous/nanocrystalline composite coatings were prepared on AISI 1045 steel substrate by electro-brush plating technique. The surface morphology, component and the phase structure of coatings were observed by Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-Ray Diffraction (XRD), respectively. The coatings were further analyzed by Transmission Electron Microscope (TEM). Then the thermal stability of coatings with different content of La2O3 was also analyzed under different annealing temperature. It was found that the coating had a unique microstructure consisting of amorphous and nanocrystalline structures. The addition of La2O3 does improve the thermal stability of metastable Ni-B coatings when the annealing temperature is over 355 °C. In addition, the thermal stability of the amorphous/nanocrystalline coatings depends on the percentage of amorphous phase and grain sizes.

High temperature wear is a common phenomenon, but in the field of high-entropy alloys, there are limited literatures on the wear behavior of laser-cladded high-entropy alloy coatings at elevated temperature. In this work, the wear performance of laser-cladded FeNiCoAlCu high-entropy alloy coating at room temperature, 200 °C, 400 °C, 600 °C and 800 °C were investigated in detail. The phase constitution and microstructure of laser-cladded FeNiCoAlCu high-entropy alloy coating were analyzed by XRD, SEM, EPMA and TEM. The results show that the synthesized FeNiCoAlCu high-entropy alloy coating is composed of FCC and BCC solid solution phases with a typical uniform dendrite microstructure, and the phase constitution of inter-dendritic region and dendritic region are Fe-rich BCC and Cu-rich FCC solid solution, respectively. The high-temperature XRD and DSC results indicate that the laser-cladded FeNiCoAlCu high-entropy alloy coating has a good thermal-stability below 780 °C. The laser-cladded FeNiCoAlCu high-entropy alloy coating also has a good wear performance at high temperature, which is mainly attributed to the formation of oxide films on the surface of the coating. The wear mechanisms are dominated by abrasive wear and oxidative wear.

The carburized 12Cr2Ni4A alloy steel was implanted by Ti + N double elements implantation. The microstructure, nano-hardness and corrosion properties were investigated by EPMA, TEM, XPS, nano-hardness and electrochemistry tests in detail. The results showed that the Ti + N co-implanted layer is composed of FCC TiN and TiC phases with BCC martensite. Compared with the un-implanted layer, the Ti + N implanted layer has higher nano-hardness and better corrosion resistance. In addition, the higher nano-hardness was presented below the surface of 1800 nm compared with un-implanted layer, which is far beyond the thickness of the implanted layer. The results also indicated that the generation of nanoscale ceramic phase and structures are not the only factor to impose the influence on the nano-hardness and corrosion resistance, but the radiation damage and lattice distortion will play an important role.

An attempt, combined with the technologies of laser cladding and laser remelting, has been made to develop a Ni-Cr-Co-Ti-V high entropy alloy coating. The phase composition, microstructure, micro-hardness and wear resistance (rolling friction) were studied in detail. The results show that after laser remelting, the phase composition remains unchanged, that is, as-cladded coating and as-remelted coatings are all composed of (Ni, Co)Ti2 intermetallic compound, Ti-rich phase and BCC solid solution phase. However, after laser remelting, the volume fraction of Ti-rich phase increases significantly. Moreover, the micro-hardness is increased, up to ∼900 HV at the laser remelting parameters: laser power of 1 kW, laser spot diameter of 3 mm, and laser speed of 10 mm/s. Compared to the as-cladded high-entropy alloy coating, the as-remelted high-entropy alloy coatings have high friction coefficient and low wear mass loss, indicating that the wear resistance of as-remelted coatings is improved and suggesting practical applications, like coatings on brake pads for wear protection. The worn surface morphologies show that the worn mechanism of as-cladded and as-remelted high-entropy alloy coatings are adhesive wear.

Alloyed layer with gradient structure was prepared on the surface of 20Cr2Ni4A steel by lanthana-bearing supersonic fine particle bombarding (SFPB). Microstructure features of the surface layer were characterized. Subsequently, the samples were carburized in an ECM vacuum furnace. Based on the experimental observations, the mechanism of promoting the diffusion of carbon atoms by lanthana-bearing SFPB was proposed. It mainly involves the promotion of the structure obtained by lanthana-bearing SFPB on the adsorption and diffusion of carbon atoms during carburization. The promotion mechanism of the rare earth in the alloying layer on carbon atom diffusion was analyzed from the aspects of accelerating mechanism of carbon source decomposition by rare earth, subsurface diffusion channel mechanism and driving force. Experimental evidence and related mechanisms show that, the structure formed by the step of austenitization during carburization and the existence of rare earth are necessary to promote the diffusion of carbon atoms. Therefore, our research results clarify the promotion mechanism of lanthana-bearing SFPB treatment on the diffusion of carbon atoms in the carburizing process, and further useful to adjust the surface structure to promote the application of pretreatment technology in surface modification.

The fracture behavior of high-profile high-entropy alloy coating was characterized by in-situ TEM tensile testing. The samples for in-situ TEM tensile testing were obtained by FIB technology. The results show that irrelevant to phase constitution, the Young's module, fracture strength and ultimate elongation are measured as ∼107 GPa, ∼2.70 GPa and ∼2.6%, respectively. Transcrystalline fracture and cleavage fracture with the cleavage plane of {112} are observed evidentially and the evolution of the dislocation motion in the material could be directly connected with the fracture behavior from the recorded movies obtained by a Gatan CCD camera. The engineering stress-strain curve is nearly linearity, however, a slight deviation away from linearity could be noted in the end of engineering stress-strain curve, which is attributed that the extra elastic deformation results in part of continued deformation.

Plasma cladding is an effect method to prepare a large-area coating as well as HEA coatings. In this work, the relatively simple microstructure of FeCoNiAlCu high-entropy alloy coating was successfully prepared by plasma cladding. The microstructure characterization and thermodynamic calculation were studied in detail. The synthesized FeCoNiAlCu high-entropy alloy coating is composed of an FCC1 phase enriched with Fe and Cu, an FCC2 phase enriched with Cu and a BCC phase enriched with Fe. The lattice parameter of FCC1, FCC2 and BCC phases are 3.664 A, 3.634 A and 2.872 A, respectively. The thermodynamic calculation is successful to a certain extent, agreeing with the experimental characterization well in terms of phase composition and the major enriched element of phases. However, establishing a developed database of CALPHAD approach is necessary to guide the design of high-entropy alloys and predict the phase composition and properties.

As bearing parts, 12Cr2Ni4A is expected to have high hardness and excellent fatigue strength, so carburizing is employed to improve the inherit properties of 12Cr2Ni4A. However, the traditional carburizing is limited by poor microstructure distribution and low rate of carburizing. The rare earth ion implantation is known to help improving the properties of tribology, corrosion resistance and oxidation resistance of metal. In this article, the RE implantation is employed to assist the carburizing. Lanthanum and cerium ion implantations are initially used to assist 12Cr2Ni4A low pressure vacuum carburization. The microstructure, content of retained austenite, hardness, thickness of layer and carbon diffusion were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Rockwell/Vickers hardness tester, respectively. It was shown that lanthanum and cerium implantations can improve structure of the vacuum carburizing layer, and enhance the uniformity of carbon element distribution on the carburized surface. Meanwhile the RE implantation plays a positive role in promoting the surface hardness and carburized rate. The lanthanum element has more significant effect on surface hardness and content of retained austenite than cerium element. The surface hardness of lanthanum element implanted layer was 62.9 HRC with 9.6% content of retained austenite, while the carburizing rate of cerium implanted layer increased by 12.4%.

Fe60(NiCrCoTiVx)40 (x = 0, 0.5, 1) multicomponent alloy coatings on low-cost AISI 1045 steel were successfully prepared by laser surface alloying. The effect of V content on microstructure, micro-hardness, wear resistance and corrosion resistance were studied in detail. The Fe60(NiCrCoTiVx)40 (x = 0, 0.5, 1) multicomponent alloy coatings are all composed of a FCC solid solution phase and a BCC solid solution phase with a Fe2Ti-type Laves phase. The lattice parameter of the BCC solid solution phase is not sensitive to V content, but the addition of V leads to the decrease of FCC content and the refinement of Fe2Ti-type Laves phase. The addition of V significantly affects the properties of coatings, and the Fe60(NiCrCoTiV0.5)40 multicomponent alloy coating has higher micro-hardness and better wear resistance while the Fe60(NiCrCoTiV1)40 multicomponent alloy coating has the best corrosion resistance. In addition, the corrosion resistance of Fe60(NiCrCoTiVx)40 (x = 0, 0.5, 1) multicomponent alloy coatings are better than that of the corresponding reference material. The results also indicate that micro-hardness is not the only factor to impose the influence on the wear resistance and the place where corrosion first occurs may be along with the Fe2Ti-type Laves phase.

In this work, a nanocrystallisation surface layer with an average grain size of 29 nm was fabricated on the 12Cr2Ni4A steel by the supersonic fine particles bombarding (SFPB). The vacuum carburising process was carried out on the original and the SFPB pre-treatment samples. X-ray diffraction, scanning electron microscopy and hardness tester were employed to study the phase constituents, grain size, hardness and residual stress of the two carburised samples. Experimental results showed that compared to the coarse-grain carburised layer (without SFPB), the carburised layer with SFPB pre-treatment has smaller martensite and carbide, and its thickness, hardness, compressive residual stress and wear resistance have been significantly improved. The dominant wear mechanisms of the two carburised samples were both abrasive wear and fatigue wear.

In mammals, PIAS proteins are important SUMO E3 ligases and act as versatile regulators of over sixty different proteins, including components from the NF-κB pathways. But the PIAS functions are not well-understood due to complicated molecular mechanisms and multiple gene paralogs with overlapping roles, which is especially true in lower vertebrates where dedicated studies are scarce. As a basal chordate with a single PIAS gene, amphioxus is a convenient model to study PIAS from the evolutionary perspective. TRAF6 is a critical adaptor of the NF-κB pathways but it is not known whether TRAF6 is regulated by PIAS. Here we discover that in mammalian cells, amphioxus PIAS inhibited NF-κB activation by co-localizing and binding with TRAF6. The interaction relied on the N-terminal SAP and PINIT domains of PIAS. TRAF6 is an E3 ubiquitin ligase, which initiates downstream NF-κB signaling by promoting its self-ubiquitination. Both amphioxus SUMO1 and Ubc9 (SUMO E2 ligase) could suppress TRAF6 self-ubiquitination and NF-κB activation, suggesting that the SUMOylation activity competed away the ubiquitination activity of TRAF6. However, we show that the wild-type PIAS and the mutant PIAS without SUMO E3 ligase activity both could inhibit TRAF6-mediated NF-κB activation by reducing TRAF6 self-ubiquitination. This implies that SUMO ligase activity is not the only mechanism for PIAS to negatively regulate TRAF6. Finally, we tested the interactions between human PIAS1-4 and TRAF6. It reveals that human PIAS1, 3 and 4, but not 2, were able to repress NF-κB activation by reducing TRAF6 self-ubiquitination. Taken together, our study discovers a conserved regulatory interaction between chordate PIAS and TRAF6. It therefore sheds light on the complicated role of PIAS in immune regulation, and may help to understand the PIAS functions in other lower chordate taxa, such as jawless and jawed fishes.

Apextrin C-terminal (ApeC) is a novel protein domain with unknown functions, although early studies suggest that some ApeC-containing proteins (ACPs) bind to carbohydrates and have a role in development and immunity. Here we investigated the taxonomic distribution, sequence diversification and origin of ACPs in Metazoa. Most ACPs are present in invertebrates from aquatic or moist environments, including cnidarians, mollusks, echinoderms, cephalochordates, flatworms, water bears, nematodes and annelids. However, ACPs are absent in vertebrates and in most arthropod lineages (e.g. insects and crustaceans) except arachnids. ACPs apparently undergo rapid turnover and diversification, hence no orthologs could be found between (sub)phyla. ApeC can function either as a standalone domain or as a partner domain. It has been found to pair up with over ten different domain types in different ACPs. The partner domains are related to immunity, extracellular matrix, protein-protein and protein-carbohydrate interactions. Notably, the domain pair with the widest taxonomic distribution is MACPF/perforin-ApeC, which represent a classic group of ACPs called apextrins. ApeC also frequently pairs up with itself to form dual-ApeC modules in different phyla. Notably, in parasite flatworms, dual-ApeCs are present in 70% of ACPs and all inherited from a common ancestor. The broad distribution of MACPF-ApeC and dual-ApeC suggest their conserved yet unknown functions. We also discovered distant ApeC homologs in bacteria, hence tracing the origin of ApeC back to prokaryotes. Our findings show that ApeC has an ancient origin and is able to function alone or in complex domain architectures, though it is less prevalent than other versatile domains such as immunoglobulin domains and C-type lectin domains. This work provides a foundation for further functional study of this novel domain type.