Microporous metallic scaffolds supported liquid infused icephobic construction.

Ice accretion on component surfaces often causes severe impacts or accidents. Liquid-infused surfaces (LIS) have drawn much attention as icephobic materials for ice mitigation in recent years due to their outstanding icephobicity. However, the durability of LIS constructions remains a big challenge, including mechanical vulnerability and rapid depletion of lubricants. The practical applications of LIS materials are significantly restrained, and the full potential of LIS for ice prevention has yet to be demonstrated. A universal approach was proposed to introduce microporous metallic scaffolds in the LIS construction to increase the applicability and durability, and to prompt the potential of LIS for ice mitigation. Microporous Ni scaffolds were chosen to integrate with polydimethylsiloxane modified by silicone oil addition. The new LIS construction demonstrated significantly improved durability in icing/de-icing cyclic test, and it also offered a solution for the rapid oil depletion by restraining the deformation of the matrix material. Low ice adhesion strength could be maintained via a micro-crack initiation mechanism. The results indicated that the multi-phase LIS construction consisting of microporous Ni scaffolds effectively addressed the shackles of the icephobicity deterioration of LIS materials, confirming a new design strategy for the R&D of icephobic surfaces

Prognostic analysis of breast cancer in Xinjiang based on Cox proportional hazards model and two−step cluster method

ObjectiveTo examine the factors that affect the prognosis and survival of breast cancer patients who were diagnosed at the Affiliated Cancer Hospital of Xinjiang Medical University between 2015 and 2021, forecast the overall survival (OS), and assess the clinicopathological traits and risk level of prognosis of patients in various subgroups.MethodFirst, nomogram model was constructed using the Cox proportional hazards models to identify the independent prognostic factors of breast cancer patients. In order to assess the discrimination, calibration, and clinical utility of the model, additional tools such as the receiver operating characteristic (ROC) curve, calibration curve, and clinical decision curve analysis (DCA) were used. Finally, using two-step cluster analysis (TCA), the patients were grouped in accordance with the independent prognostic factors. Kaplan-Meier survival analysis was employed to compare prognostic risk among various subgroups.ResultT-stage, N-stage, M-stage, molecular subtyping, type of operation, and involvement in postoperative chemotherapy were identified as the independent prognostic factors. The nomogram was subsequently constructed and confirmed. The area under the ROC curve used to predict 1-, 3-, 5- and 7-year OS were 0.848, 0.820, 0.813, and 0.791 in the training group and 0.970, 0.898, 0.863, and 0.798 in the validation group, respectively. The calibration curves of both groups were relatively near to the 45° reference line. And the DCA curve further demonstrated that the nomogram has a higher clinical utility. Furthermore, using the TCA, the patients were divided into two subgroups. Additionally, the two groups’ survival curves were substantially different. In particular, in the group with the worse prognosis (the majority of patients did not undergo surgical therapy or postoperative chemotherapy treatment), the T-, N-, and M-stage were more prevalent in the advanced, and the total points were likewise distributed in the high score side.ConclusionFor the survival and prognosis of breast cancer patients in Xinjiang, the nomogram constructed in this paper has a good prediction value, and the clustering results further demonstrated that the selected factors were important. This conclusion can give a scientific basis for tailored treatment and is conducive to the formulation of focused treatment regimens for patients in practical practice

Metallic skeleton promoted two-phase durable icephobic layers

HypothesisThe accretion of ice on component surfaces often causes severe impacts or accidents in modern industries. Applying icephobic surface is considered as an effective solution to minimise the hazards. However, the durability of the current icephobic surface and coatings for long-term service remains a great challenge. Therefore, it is indeed to develop new durable material structures with great icephobic performance.ExperimentsA new design concept of combining robust porous metallic skeletons and icephobic filling was proposed. Nickel/polydimethylsiloxane (PDMS) two-phase layer was prepared using porous Ni foam skeletons impregnated with PDMS as filling material by a two-step method.FindingsGood icephobicity and mechanical durability have been verified. Under external force, micro-cracks could easily initiate at the ice/solid interface due to the small surface cavities and the difference of local elastic modulus between the ice and PDMS, which would promote the ice fracture and thus lead to low ice adhesion strength. The surface morphology and icephobicity almost remain unchanged after water-sand erosion, showing greatly improved mechanical durability. By combining the advantages of the mechanical durability of porous Ni skeleton and the icephobicity of PDMS matrix, the Ni foam/PDMS two-phase layer demonstrates great potentials for ice protection with long-term service time

Analysis of COVID-19 Guideline Quality and Change of Recommendations: A Systematic Review.

Background Hundreds of coronavirus disease 2019 (COVID-19) clinical practice guidelines (CPGs) and expert consensus statements have been developed and published since the outbreak of the epidemic. However, these CPGs are of widely variable quality. So, this review is aimed at systematically evaluating the methodological and reporting qualities of COVID-19 CPGs, exploring factors that may influence their quality, and analyzing the change of recommendations in CPGs with evidence published. Methods We searched five electronic databases and five websites from 1 January to 31 December 2020 to retrieve all COVID-19 CPGs. The assessment of the methodological and reporting qualities of CPGs was performed using the AGREE II instrument and RIGHT checklist. Recommendations and evidence used to make recommendations in the CPGs regarding some treatments for COVID-19 (remdesivir, glucocorticoids, hydroxychloroquine/chloroquine, interferon, and lopinavir-ritonavir) were also systematically assessed. And the statistical inference was performed to identify factors associated with the quality of CPGs. Results We included a total of 92 COVID-19 CPGs developed by 19 countries. Overall, the RIGHT checklist reporting rate of COVID-19 CPGs was 33.0%, and the AGREE II domain score was 30.4%. The overall methodological and reporting qualities of COVID-19 CPGs gradually improved during the year 2020. Factors associated with high methodological and reporting qualities included the evidence-based development process, management of conflicts of interest, and use of established rating systems to assess the quality of evidence and strength of recommendations. The recommendations of only seven (7.6%) CPGs were informed by a systematic review of evidence, and these seven CPGs have relatively high methodological and reporting qualities, in which six of them fully meet the Institute of Medicine (IOM) criteria of guidelines. Besides, a rapid advice CPG developed by the World Health Organization (WHO) of the seven CPGs got the highest overall scores in methodological (72.8%) and reporting qualities (83.8%). Many CPGs covered the same clinical questions (it refers to the clinical questions on the effectiveness of treatments of remdesivir, glucocorticoids, hydroxychloroquine/chloroquine, interferon, and lopinavir-ritonavir in COVID-19 patients) and were published by different countries or organizations. Although randomized controlled trials and systematic reviews on the effectiveness of treatments of remdesivir, glucocorticoids, hydroxychloroquine/chloroquine, interferon, and lopinavir-ritonavir for patients with COVID-19 have been published, the recommendations on those treatments still varied greatly across COVID-19 CPGs published in different countries or regions, which may suggest that the CPGs do not make sufficient use of the latest evidence. Conclusions Both the methodological and reporting qualities of COVID-19 CPGs increased over time, but there is still room for further improvement. The lack of effective use of available evidence and management of conflicts of interest were the main reasons for the low quality of the CPGs. The use of formal rating systems for the quality of evidence and strength of recommendations may help to improve the quality of CPGs in the context of the COVID-19 pandemic. During the pandemic, we suggest developing a living guideline of which recommendations are supported by a systematic review for it can facilitate the timely translation of the latest research findings to clinical practice. We also suggest that CPG developers should register the guidelines in a registration platform at the beginning for it can reduce duplication development of guidelines on the same clinical question, increase the transparency of the development process, and promote cooperation among guideline developers all over the world. Since the International Practice Guideline Registry Platform has been created, developers could register guidelines prospectively and internationally on this platform

Study on multi-phase structured icephobic constructions

The accumulation of ice on critical infrastructure, such as aviation, telecommunication, electricity, and transportation systems, can cause severe disruptions to daily life and significant economic losses. While applying icephobic coatings has been proposed as a potential solution, the challenge remains in creating coatings that can effectively withstand adverse environmental conditions, and also demonstrate a long service life and mechanical durability. The motivation of the work is to provide a comprehensive analysis of the fundamental aspects related to icephobicity research, and to explore novel, durable icephobic materials and surfaces, to produce well-rounded research outcomes. Liquid-infused surfaces (LIS) with self-replenishing properties have been adopted for anti-icing and de-icing applications. However, the mechanical durability of the LIS polymer is limited, rendering them unsuitable for long-term practical use in ice protection. To alleviate the difficulties associated with limited mechanical durability and rapid oil depletion among LIS structures, this study proposes a multi-phase LIS construction based on microporous metallic scaffolds. The proposed approach aims to tackle the problem of icephobicity deterioration in LIS materials. Specifically, the study employed Ni scaffolds and a PDMS-modified silicone oil (NP-SO) system for the LIS construction. The inclusion of Ni scaffolds facilitated stress redistribution during de-icing, thereby safeguarding the LIS material from external loads and impacts. As a result, the ice adhesion strength of the NP-SO samples down to 2.0 ± 0.7 kPa after undergoing 50 cycles of anti-icing/de-icing tests. Conversely, samples without Ni scaffolds demonstrated surface damage after 30 cycles of anti-icing/de-icing tests. The rapid depletion of infused oil due to large polymer deformation was also addressed. The multi-phase construction reduced oil depletion by over three times after 50 cycles of anti-icing/de-icing tests, providing a resolution for the oil depletion concerns in extended service environments. To achieve enhanced icephobic performance and durability, a novel design concept involving the integration of phase change liquids with Ni scaffolds and polydimethylsiloxane (PDMS) has been introduced in the multi-phase icephobic construction. Incorporating phase change liquids within the LIS construction allows for heat absorption and release during the icing process, which enhances icephobic performance. Differential scanning calorimetry analysis demonstrated that samples with phase change liquids have a phase change enthalpy of 3.2 J/g for groundnut oil and 3.8 J/g for coconut oil, respectively. As a result of the heat release during the phase change process of the incorporated phase change liquids, the surface temperature of the sample increased, resulting in a delayed ice formation of the supercooled water droplet. The observed freezing time of the droplets on the sample surface was 7-8 times longer than that observed on aluminum alloy. Solidification of the phase change liquids occurred at a low temperature, leading to a concurrent reduction in oil depletion during the de-icing process. This effect was confirmed from the weight maintenance ratio of samples, which remained unchanged even after undergoing 50 cycles of anti-icing/de-icing tests. The introduction of phase change liquids has been demonstrated to be a viable strategy for enhancing the anti-icing performance of icephobic surfaces. A high-quality icephobic surface should encompass multiple facets of icephobicity, such as anti-icing performance, de-icing ability, and mechanical stability. It is noteworthy that achieving all of these requirements simultaneously is a formidable challenge. To address this issue, a potential icephobic structure has been proposed, which incorporates Ni scaffolds with ice depressing liquid and a polydimethylsiloxane (PDMS) matrix. The ice depressing liquid utilized in this study included glycol and glycerol. The incorporation of ice depressing liquid into the surface layer led to an increase in the amount of hydroxyl groups present, resulting in a notable reduction in the freezing point of supercooled droplets at the liquid-solid interfaces. Furthermore, samples containing ice depressing liquid exhibited a considerable delay in the onset of icing, with respective times of 153.7 ± 2.5 s and 209.7 ± 4.5 s. The results of anti-icing tests provided evidence of the efficacy of ice depressing liquid in reducing the icing point temperature. Upon the sample preparation, the glycol and glycerol in the ice depressing liquid underwent volatilization, leading to the formation of internal porosities within the PDMS. Despite this, the surface morphology of the samples remained smooth and intact. The presence of these internal pores could increase the difference in elastic modulus between the polymer and metallic scaffolds, thus facilitating the initiation of micro-cracks at the ice-solid interfaces and aiding in ice detachment from the sample surface. Consequently, the ice adhesion strength was reduced to below 2 kPa, in contrast to 29.8 ± 2.9 kPa observed for Ni-PDMS samples. Moreover, the results indicated that the de-icing ability of the samples remained stable throughout cyclic icing/de-icing tests

Study on multi-phase structured icephobic constructions

The accumulation of ice on critical infrastructure, such as aviation, telecommunication, electricity, and transportation systems, can cause severe disruptions to daily life and significant economic losses. While applying icephobic coatings has been proposed as a potential solution, the challenge remains in creating coatings that can effectively withstand adverse environmental conditions, and also demonstrate a long service life and mechanical durability. The motivation of the work is to provide a comprehensive analysis of the fundamental aspects related to icephobicity research, and to explore novel, durable icephobic materials and surfaces, to produce well-rounded research outcomes. Liquid-infused surfaces (LIS) with self-replenishing properties have been adopted for anti-icing and de-icing applications. However, the mechanical durability of the LIS polymer is limited, rendering them unsuitable for long-term practical use in ice protection. To alleviate the difficulties associated with limited mechanical durability and rapid oil depletion among LIS structures, this study proposes a multi-phase LIS construction based on microporous metallic scaffolds. The proposed approach aims to tackle the problem of icephobicity deterioration in LIS materials. Specifically, the study employed Ni scaffolds and a PDMS-modified silicone oil (NP-SO) system for the LIS construction. The inclusion of Ni scaffolds facilitated stress redistribution during de-icing, thereby safeguarding the LIS material from external loads and impacts. As a result, the ice adhesion strength of the NP-SO samples down to 2.0 ± 0.7 kPa after undergoing 50 cycles of anti-icing/de-icing tests. Conversely, samples without Ni scaffolds demonstrated surface damage after 30 cycles of anti-icing/de-icing tests. The rapid depletion of infused oil due to large polymer deformation was also addressed. The multi-phase construction reduced oil depletion by over three times after 50 cycles of anti-icing/de-icing tests, providing a resolution for the oil depletion concerns in extended service environments. To achieve enhanced icephobic performance and durability, a novel design concept involving the integration of phase change liquids with Ni scaffolds and polydimethylsiloxane (PDMS) has been introduced in the multi-phase icephobic construction. Incorporating phase change liquids within the LIS construction allows for heat absorption and release during the icing process, which enhances icephobic performance. Differential scanning calorimetry analysis demonstrated that samples with phase change liquids have a phase change enthalpy of 3.2 J/g for groundnut oil and 3.8 J/g for coconut oil, respectively. As a result of the heat release during the phase change process of the incorporated phase change liquids, the surface temperature of the sample increased, resulting in a delayed ice formation of the supercooled water droplet. The observed freezing time of the droplets on the sample surface was 7-8 times longer than that observed on aluminum alloy. Solidification of the phase change liquids occurred at a low temperature, leading to a concurrent reduction in oil depletion during the de-icing process. This effect was confirmed from the weight maintenance ratio of samples, which remained unchanged even after undergoing 50 cycles of anti-icing/de-icing tests. The introduction of phase change liquids has been demonstrated to be a viable strategy for enhancing the anti-icing performance of icephobic surfaces. A high-quality icephobic surface should encompass multiple facets of icephobicity, such as anti-icing performance, de-icing ability, and mechanical stability. It is noteworthy that achieving all of these requirements simultaneously is a formidable challenge. To address this issue, a potential icephobic structure has been proposed, which incorporates Ni scaffolds with ice depressing liquid and a polydimethylsiloxane (PDMS) matrix. The ice depressing liquid utilized in this study included glycol and glycerol. The incorporation of ice depressing liquid into the surface layer led to an increase in the amount of hydroxyl groups present, resulting in a notable reduction in the freezing point of supercooled droplets at the liquid-solid interfaces. Furthermore, samples containing ice depressing liquid exhibited a considerable delay in the onset of icing, with respective times of 153.7 ± 2.5 s and 209.7 ± 4.5 s. The results of anti-icing tests provided evidence of the efficacy of ice depressing liquid in reducing the icing point temperature. Upon the sample preparation, the glycol and glycerol in the ice depressing liquid underwent volatilization, leading to the formation of internal porosities within the PDMS. Despite this, the surface morphology of the samples remained smooth and intact. The presence of these internal pores could increase the difference in elastic modulus between the polymer and metallic scaffolds, thus facilitating the initiation of micro-cracks at the ice-solid interfaces and aiding in ice detachment from the sample surface. Consequently, the ice adhesion strength was reduced to below 2 kPa, in contrast to 29.8 ± 2.9 kPa observed for Ni-PDMS samples. Moreover, the results indicated that the de-icing ability of the samples remained stable throughout cyclic icing/de-icing tests

Research on food safety prediction method based on k-means clustering algorithm

Aiming at the problem of food risk prediction, this paper proposes a method based on clustering algorithm to predict product risk by raw material risk. Firstly, based on the provincial supply chain closed-loop hypothesis, this paper proposes the selection method of clustering indexes for products and their raw materials. Secondly, this paper uses the k-means clustering algorithm to cluster the products and the corresponding raw materials respectively, then based on the clustering Class results automatically determine the high-risk categories of the products and their raw materials. Finally, the analysis of the experimental data of the 8 categories of products and their raw materials shows that the ratio of the high-risk categories of products and the ratios of the corresponding high-risk categories of raw materials have a strong positive correlation. The experimental results prove the rationality of the raw material clustering index selection method proposed in this paper and the correctness of the method of predicting product risk based on the raw material risk based on the clustering algorithm

Structural, Raman spectroscopic and microwave dielectric studies on (1-x) NiZrNb2O8 - x ZnTa2O6

(1 - x) NiZrNb2O8 - x ZnTa2O6 microwave dielectric ceramics were prepared via the conventional solid-state reaction route. Structural and lattice parameters of the (1 - x) NiZrNb2O8 - x ZnTa2O6 ceramics were analyzed through X-ray diffraction, Raman spectra, and scanning electron microscopy. The results showed that there were serious ionic diffusion and solid solution reaction in the composite ceramics. The substitution of Ni2+, Zr4+, and Zn2+ at A-sites and the substitution of Nb5+ and Ta5+ at B-sites led to the change of the lattice parameters. There was a gradual transformation in crystal structure from monoclinic phase into Tri-alpha PbO2 phase with the increasing ZnTa2O6 content. With the increase of x value from 0 to 1, the epsilon (r) value increased from 23.76 to 35.71 and the Q x AE' value increased from 32107 to 46709 GHz. The temperature frequency resonance coefficient near zero could be obtained at x = 0.8. The 0.2NiZrNb(2)O(8) - 0.8ZnTa(2)O(6) ceramics were obtained at 1275 A degrees C with excellent microwave dielectric properties: epsilon (r) similar to 33.69, Q x AE' similar to 37,529 GHz and tau(AE') similar to + 2.56 ppm/A degrees C

synthesischaracterizationanddielectricpropertiesofanoveltemperaturestable1xcotinb2o8xznnb2o6ceramic

(1–x)CoTiNb_2O_8 –xZnNb_2O_6 microwave dielectric ceramics were prepared via the conventional solid-state reaction route with the aim of reducing the τ_f value and improving the thermal stability. The phase composition and the microstructure were investigated using X-ray diffraction, Raman spectra, and scanning electron microscopy. A set of phase transitions which were induced by composition had been confirmed via the sequence: rutile structure→coexistence of rutile and columbite phase→columbite phase. For (1–x)CoTiNb_2O_8 –xZnNb_2O_6 microwave dielectric ceramics, the addition of ZnNb_2O_6 content (x =0–1) led to the decrease of ε_r from 62.98 to 23.94. As a result of the high Q ×? of ZnNb_2O_6 ceramics, the increase of ZnNb_2O_6 content also led to the lower sintering temperatures and the higher Q ×? values. The τ_f value was reduced from+108.04 (x =0) to – 49.31 ppm/℃ (x = 1). Among them, high density 0.5CoTiNb_2O_8 -0.5ZnNb_2O_6 ceramics were obtained at 1175 ℃ with excellent microwave dielectric properties of ε_r 39.2, Q ×? 40013 GHz, and τ_f+ 3.57 ppm/℃

Synthesis, characterization and dielectric properties of a novel temperature stable (1-x)CoTiNb2O8-xZnNb(2)O(6) ceramic

(1-x)CoTiNb2O8-xZnNb(2)O(6) microwave dielectric ceramics were prepared via the conventional solid-state reaction route with the aim of reducing the (f) value and improving the thermal stability. The phase composition and the microstructure were investigated using X-ray diffraction, Raman spectra, and scanning electron microscopy. A set of phase transitions which were induced by composition had been confirmed via the sequence: rutile structurecoexistence of rutile and columbite phasecolumbite phase. For (1-x)CoTiNb2O8-xZnNb(2)O(6) microwave dielectric ceramics, the addition of ZnNb2O6 content (x = 0-1) led to the decrease of epsilon(r) from 62.98 to 23.94. As a result of the high Q x f of ZnNb2O6 ceramics, the increase of ZnNb2O6 content also led to the lower sintering temperatures and the higher Q x f values. The (f) value was reduced from +108.04 (x = 0) to - 49.31 ppm/degrees C (x = 1). Among them, high density 0.5CoTiNb(2)O(8)-0.5ZnNb(2)O(6) ceramics were obtained at 1175 degrees C with excellent microwave dielectric properties of epsilon(r) 39.2, Q x f 40013 GHz, and (f)+3.57 ppm/degrees C