Search

Magnetization reduction roasting is an important method for the utilization of oolitic magnetite. In this study, the magnetization reduction behavior and kinetics of oolitic hematite in gas-based roasting were systematically investigated by X-ray photoelectron spectroscopy (XPS). The results revealed that under optimal roasting conditions of 650 °C, a roasting time of 60 min, and a CO concentration of 30%, the magnetization reduction rate of the roasted product reached 44.34%. Furthermore, the weak magnetic separation concentrate presented a TFe of 58.09% and a concentrate iron recovery of 94.3%. The results of the XPS spectrum indicated that the peak area ratio (Fe2+/Fe3+) gradually increased with an increase in roasting temperature, roasting time, and CO concentration, while over-reduction occurred when the roasting temperature exceeded 750 °C. The investigation of magnetization roasting kinetics for varying particle sizes demonstrated that the magnetization reduction process is controlled by chemical reaction, with a corresponding activation energy range of 42.96 kJ/mol to 63.29 kJ/mol, indicating the particle size has little effect on the magnetization reduction of oolitic hematite. [ABSTRACT FROM AUTHOR]

Edible bird's nest (EBN) has been proven to exhibit whitening activity. In spite of this, the relationship between the digestive products of EBN and the whitening activity is still unclear. Hence, the B16-F10 cell model was used in this study to study the whitening activity of simulated EBN digestion products in vitro. The simulated digestive juices showed significant inhibition of tyrosinase (TYR) (P < 0.05), and the release rate of free sialic acid was 21.87% in EBN digestive juices. After simulated gastrointestinal digestion, the relative contents of <1 kDa components, 1–3 kDa components, and >3 kDa components were 42.63%, 15.05%, and 42.32%, respectively. EBN digestive products were further fractionated, and the fraction of <1 kDa (EPP-1) exhibited the highest tyrosinase inhibitory activity with 83.12% and its peptides content was 92.44%. The EPP-1 significantly inhibited tyrosinase activity and decreased melanin content (P > 0.05) by regulating the cAMP/MITF/TRP-1/TRP-2 tyrosinase signaling pathways in the B16-F10 cell experiment. Based on these findings, our data suggest that the digestive products of EBN may potentially be fit for developing a new generation of natural whitening health products. [ABSTRACT FROM AUTHOR]

In order to promote the high value-added utilization of high calcium fly ash, the geopolymer with excellent mechanical properties was prepared using fly ash as main raw material by water glass alkali excitation. Then, hydrogen peroxide was introduced as foaming agent, sodium dodecyl sulfate (SDS) was used as foaming stabilizer and the foaming process was optimized to prepare porous foaming geopolymer. The pore size distribution of foaming section was analyzed by Image-Pro Plus image software and the microstructure of foaming geopolymer was characterized by XRD, FTIR and SEM-EDS. The results show that under the conditions of liquid-solid ratio of 0. 50, alkali equivalent of 10% (mass fraction), water glass modulus of 1. 50, H2O2 content of 3% (mass fraction), SDS content of 0. 3% (mass fraction) and foaming at 80 °C for 4 h, the 28 d compressive strength of specimen after standard curing is 1. 78 MPa, and the apparent density is 631 kg/m³. Foaming geopolymer has small pore size and uniform distribution, resulting in low density. The polymerization product is a small amount of C-S-H gel and a large amount of N(C)-A-S-H gel produced by the synergistic reaction of calcium, aluminum and sodium, which ensures the mechanical strength of foaming geopolymer. [ABSTRACT FROM AUTHOR]

Most spectral data, such as those obtained via infrared, Raman, and mass spectroscopy, have baseline drifts due to fluorescence or other reasons, which have an adverse impact on subsequent analyses. Therefore, several researchers have proposed the use of various baseline-correction methods to address the aforementioned issue. However, most baseline-correction methods require manual adjustment of the parameters to achieve desirable performance. In this study, we propose a baseline-correction method based on a deep-learning model that combines ResNet and UNet. The method uses a deep-learning model trained with simulated spectral data to perform baseline corrections and eliminates the need for manual parameter adjustments. Based on the results of the qualitative and quantitative analyses of the simulated spectral data and actual Raman spectra, the proposed method is easier to apply and has better performance compared to the existing methods. As the proposed method can be applied to Raman spectra and other spectra, it is expected to be widely used. [ABSTRACT FROM AUTHOR]

Sintering accounts for about 50% of the total NOx emissions of the iron and steel industry. NOx emissions from the sintering process can be simulated using the emissions from coke combustion. However, the generation and emission law for NOx burning in the sintering process of pulverized coal is still not clear. The formation characteristics of NOx during coal combustion catalyzed by iron ore fines and several iron-containing pure minerals were studied in this paper. The results showed that iron ore fines can improve the NOx emission rate and increase the total NOx emissions during coal combustion. The type and composition of the iron ore fines have an important impact on the generation and emission of NOx in the process of coal combustion. The peak concentration and emissions of NOx in coal combustion flue gas with limonite, hematite or specularite added increased significantly. The peak value for the NOx concentration in the coal combustion flue gas with magnetite or siderite added increased, but the emissions decreased. Therefore, the generation of NOx in the sintering process can to a certain extent be controlled by adjusting the type of iron-containing raw materials and the distribution of the iron-containing raw materials and coal. [ABSTRACT FROM AUTHOR]

Enterprise strategic management is not only an important part of enterprise work, but also an important factor to deepen the reform of management system and promote the centralized and unified management of enterprises. Enterprise strategic management is to study the major problems of survival and development of enterprises in the competitive environment from the overall and long-term point of view. It is the most important function of senior leaders of modern enterprises. Starting from the characteristics of the recognition object, this paper analyzes the individual differences of biometrics through intelligent face image recognition technology to identify biometrics, which can be used to identify different individuals. This paper studies the main problems of personnel identity authentication in the current enterprise strategic management system. Based on identity management and supported by face image recognition technology, deep learning, and cloud computing technology, the personnel management model of the management system is constructed, which solves the problems of personnel real identity authentication and personnel safety behavior control. Experiments show that the model can simplify the workflow, improve the operation efficiency, and reduce the management cost. From the perspective of enterprise system development, building a scientific enterprise strategic management system is of great significance to improve the scientific level of enterprise system management. [ABSTRACT FROM AUTHOR]

Using an energy-based method, this paper investigates the [L.sub.2] disturbance attenuation excitation control of multimachine power system connected with constant power loads. First, a general result is presented for the [L.sub.2] disturbance attenuation control of nonlinear differential algebraic systems with dissipative Hamiltonian realization. Then, pre-feedback is employed to transform the power system into a dissipative Hamiltonian form. Based on this, a decentralized [L.sub.2] excitation control scheme is proposed to improve the transient stability of the system. Simulation results demonstrate the effectiveness of the controller. Index Terms--Dissipative Hamiltonian realization, [L.sub.2] disturbance attenuation, multimachine multiload power systems, nonlinear differential algebraic systems.

Accumulating evidences have shown the beneficial effects of natural products for Alzheimer's disease (AD) treatment. The present study was designed to investigate the neuroprotective effects of secondary metabolites of Galactomyces geotrichum (SMGG) on D-galactose induced AD mice. SMGG was extracted and its toxicological evaluation was conducted. To explore the neuroprotective mechanism responsible for anti-AD activity of SMGG, spatial learning and memory behavioral, oxidative stress levels, acetylcholinesterase and choline acetyltransferase activity assays were employed. The AD mice received SMGG treatment exhibited significant improvement in cognitive performance, enhanced antioxidant capacity, decreased acetylcholinesterase activity and increased choline acetyltransferase activity. Meanwhile, SMGG had no toxicity and seven compounds were separated from it: 7,8-dimethyl-iso-alloxazine, 1-methyl-3-benzyl-6-(4-hydroxybenzyl)-2,5-piperzainedione, cyclo-(Phe-Pro), cyclo-(Leu-Pro), cyclo-(Pro-Gly), cyclo-(Gly-Leu) and uracil, respectively. Overall, these data suggested that SMGG protects the brain against D-galactose induced cognitive impairment, oxidative damages and acetylcholine content decrease in AD mice. [ABSTRACT FROM AUTHOR]

Objectives: Acute coronary syndrome (ACS) is an acute disease with high mortality. Although early percutaneous coronary intervention (PCI) is proved to be the practical approach in treating ACS, the incidence of cardiovascular events is still far from satisfactory. The combination of Suxiao Jiuxin Pill (SJP) and Western medicine is one conventional approach in the treatment of ACS. Many elementary and clinical trials have proved the efficacy and safety in the improvement of cardiocerebral vascular conditions. The aim of this project is to evaluate the safety and efficacy of SJP on ACS with early PCI patients. Trial Design: This is a multicenter randomized, double-blind placebo-controlled trial. Trial registration: ChiCTR-TRC-13003053. Settings: Hospitals. Subjects: A total of 200 ACS with early PCI patients were randomly divided into SJP group (n = 100) and placebo group (n = 100). Interventions: The SJP group was treated with routine treatment and SJP (taking eight SJP pills orally each time, three times per day). The placebo group was treated with routine treatment along with equal amounts of SJP placebo. The course of treatment was 6 months and a follow-up visit at 12 months. Outcome Measures: Assessments of major adverse cardiovascular events (MACE), safety assessments, adverse events, left ventricular systolic function (LVEF), Seattle angina questionnaire (SAQ), troponin C (cTNI), C-reactive protein (CRP), fibrinogen (Fib), and cystatin C (cysC). Results: The SJP group had a relatively low incidence of MACE than the placebo (p < 0.05, odds ratio: 1.916, 95% confidence interval [0.999–3.674]). LVEF was significantly higher in the SJP group than the placebo group on the 360-day follow-up (p < 0.01). SJP had a significant increase score in the SAQ subscale of physical limitation, angina frequency, and treatment satisfaction (p < 0.05). There is no significant difference in the cTNI and CRP level between the two groups. The serum concentration of Fib and cysC in the SJP was significantly decreased compared with the placebo (p < 0.05). The numbers of adverse events between the two groups were not statistically different (p > 0.05). Conclusions: SJP is associated with a reduction in MACE, and an improvement of heart function and quality of life in ACS patients with early PCI, and is probably safe to use. [ABSTRACT FROM AUTHOR]

In order to improve the intelligence of higher mathematics teaching resource scheduling, a higher mathematics teaching resource scheduling system based on cloud computing is designed. A balanced modulation control algorithm for higher mathematics teaching resources is proposed on the overall design of this system and an association rule constraint model for higher mathematics teaching resource allocation is constructed based on the design results. The adaptive weighted control method is adopted for distributed control of higher mathematics teaching resources and a priority attribute list of higher teaching resource scheduling is established. The higher mathematics teaching resource allocation and adaptive information fusion are realized according to the priority list. On this basis, the higher mathematics teaching resource scheduling system based on cloud computing is designed optimally through the embedded control technology. The simulation results show that, in the allocation of teaching resources, the balance coefficient of higher mathematics teaching resource scheduling system based on cloud computing has increased by 12.54%, and the accuracy of sending and receiving teaching data provided by this system has improved by 13.6%, which indicates that this system has relatively good intelligence and strong human-computer interaction ability. [ABSTRACT FROM AUTHOR]

This network meta-analysis addresses the need for evidence-based best-practice treatment regimens for HER2-positive breast cancer. We compared the relative efficacy and tolerability of currently available HER2-positive neoadjuvant immunotherapy regimens based on systematic searches of available randomized controlled trials (RCTs) data. Based on intention-to-treat principle, pathological complete response (pCR), overall serious adverse events (SAEs), and breast-conserving surgery (BCS) rate were analyzed using random-effect, Bayesian network meta-analysis, and standard pairwise meta-analysis. 16 RCTs (3868 patients) were included. Analyzed treatment regimens were as follows: chemotherapy+trastuzumab+pertuzumab (CTP), trastuzumab emtansine+pertuzumab (MP), chemotherapy+trastuzumab (CT), chemotherapy+pertuzumab (CP), trastuzumab+pertuzumab (TP), chemotherapy+trastuzumab+lapatinib (CTL), and chemotherapy+lapatinib (CL), and chemotherapy (C) alone. We found that, for the chance of achieving pCR, CTP was ranked first (SUCRA: 97%), followed by CTL, MP, and CT (SUCRA: 80%, 75%, and 55%, resp.). MP provided the safest regimen (SUCRA: 97%), then TP, C, and TPC (SUCRA: 82%, 76%, and 47%, resp.). CTL proved the most toxic therapy (SUCRA: 7%). No significant difference between neoadjuvant regimens was identified for BCS. Hormone receptor status did not impact ORs for pCR in any regimen. In conclusion, our findings support CTP as the optimum neoadjuvant regimen for HER2-positive breast cancer, with the best pCR and acceptable toxicity compared with CT. MP provides a therapeutic option for patients with poor performance status. [ABSTRACT FROM AUTHOR]

There has been increasing demands for large-scale pelletization equipment recently in order to improve the composition of blast furnace burden, conserve energy and reduce emission. Accordingly, the BaoSteel built the Zhanjiang palletization plant with the capacity of 5 million-tons per year, which holds the record in the world for the largest grate-kiln to produce fluxed pellets. The features included preprocessing raw materials with the combination of ball mills and high-press roller presses, production of fluxed pellets with limestone, pre-mixing of dust wastes, and advanced desulfurization technologies. This plant has marked an important step in the development of grate-kiln pelletization technology. [ABSTRACT FROM AUTHOR]

The Ezhou pelletization plant of the BAOWU with production capacity of 5,000,000 ton oxide pellets per year has the biggest single production line of Grate-Kiln-Ring cooler, which was provided by Metso Company. The iron concentrate was mainly imported from Brazil and self-provided by Jinshandian. The iron concentrates were dried and ground by the high pressure roller. The ground iron concentrates were pelleted by drum and disc pelletizers. The qualified green pellets were subjected to grate, rotary kiln, and ring cooler successively. The innovation and creation of process and equipment of Ezhou pelletization plant of BAOWU plays an exemplary role for the application of large-scale grate-kiln-cooler in iron and steel industrial. The use of the high pressure roller grinding significantly improved the pelletization ability of the iron concentrate and the quality of the finished pellets. Compared with other same scale grinding equipment, it is more energy-saving. The combined technique of high pressure roller with wet ball mill grinding was used to treat some hard specularite with large particle size. The first successful application and design of electrostatic precipitator on the large-scale grate-kiln in China provides a good foundation for other large-scale pellets plants. [ABSTRACT FROM AUTHOR]

In this paper, firstly, we study the linear processing of amplify-and-forward (AF) relays for the multiple relays multiple users scenario. We regard all relays as one special “relay”, and then the subcarrier pairing, relay selection and channel assignment can be seen as a linear processing of the special “relay”. Under fixed power allocation, the linear processing of AF relays can be regarded as a permutation matrix. Employing the partitioned matrix, we propose an optimal linear processing design for AF relays to find the optimal permutation matrix based on the sorting of the received SNR over the subcarriers from BS to relays and from relays to users, respectively. Then, we prove the optimality of the proposed linear processing scheme. Through the proposed linear processing scheme, we can obtain the optimal subcarrier paring, relay selection and channel assignment under given power allocation in polynomial time. Finally, we propose an iterative algorithm based on the proposed linear processing scheme and Lagrange dual domain method to jointly optimize the joint optimization problem involving the subcarrier paring, relay selection, channel assignment and power allocation. Simulation results illustrate that the proposed algorithm can achieve a perfect performance. [ABSTRACT FROM AUTHOR]

Gly-Pro-Ala-Gly-Pro-His-Gly-Pro-Pro-Gly ( GPAGPHGPPG), a chelating peptide derived from Alaska pollock skin, has been approved with outstanding ability to chelate calcium, zinc and iron ions. In this study, the stability of GPAGPHGPPG during in vitro gastrointestinal enzymatic digestion, the potential binding site between peptide and metal ions as well as its effects on mineral transport in Caco-2 cells were investigated. Results showed that approximately 75% of GPAGPHGPPG remained intact at the end of the in vitro gastrointestinal enzymatic digestion. The formation of peptide-metal complex was potentially related to histidine and cyclic structure in terms of dehydration. Moreover, GPAGPHGPPG revealed significant promotional effects on calcium (112.7%, P < 0.01), zinc (32.3%, P < 0.01) and iron (27.7%, P < 0.01) transport in Caco-2 cell monolayer. In conclusion, GPAGPHGPPG could be developed as a potential functional ingredient to prevent mineral deficiency. [ABSTRACT FROM AUTHOR]

Sea cucumbers treated by high pressure steam ( HPSC) could degrade during storage at 4C. Texture profile analysis was explored, and it showed that after 160 days the hardness and chewiness decreased dramatically from 295.85 to 15.67 gf and from 227.08 to 9.18 gf2 s, respectively. The water activity significantly increased from 0.935 to 0.973, and the content of free water rose as the proportion of transverse relaxation time (T23) mounted from 0.810 to 0.901 after 45 days. In addition, T1-weighted and T2-weighted imaging confirmed that the distribution of immobilized water and free water in body wall underwent significant changes after 60 days. The collagen fibers fractured, free hydroxyproline and ammoniacal nitrogen levels increased significantly during storage. The present findings indicated that the degradation of HPSC was primarily caused by the destruction of body wall, which was related to the water distribution and the decline of quality. Practical Applications Sea cucumber has become an important food resource due to its high nutritional value. It is well known that sea cucumbers are easy to autolyze when taken out of sea water because of enzymes, microorganisms and several environmental factors. Therefore, it is difficult to preserve and transport sea cucumbers. Various drying methods were used to extend the quality and shelf life and that would bring nutrition loss and food safety problems. The enzymes and microorganisms were inactivated by high pressure steam sterilization, which could prolong shelf life and maintain quality of sea cucumbers. However, sea cucumbers treated by high pressure steam ( HPSC) degraded after a period of storage time. This study aimed to study the degradation and the associated mechanism of HPSC during storage. [ABSTRACT FROM AUTHOR]

The oxidation behaviour of vanadium in stone coal and its mechanisms in conventional blank roasting (CBR) and microwave blank roasting (MBR) are investigated. In both roasting methods, vanadium oxidation rates are increased and the controlling step of vanadium oxidation reaction is changed from chemical control to internal diffusion control with increasing temperature. Compared to CBR, MBR was more efficient in vanadium oxidation under same roasting conditions. The change of controlling step occurred at the temperature range of 500–600 °C and 600–700 °C for MBR and CBR, respectively. This oxidation behaviour of vanadium was mainly dependent on the reducing materials in stone coal and their reaction characteristics. Due to efficient and the lower temperatures of mineral transformations (including reaction of reducing materials and deformation of muscovite structure), MBR had higher vanadium oxidation efficiency and lower temperature range of changing the controlling step than CBR. [ABSTRACT FROM AUTHOR]

The cement industry has for some time been seeking alternative raw material for the Portland cement clinker production. The aim of this research was to investigate the possibility of utilizing iron ore tailings (IOT) to replace clay as alumina-silicate raw material for the production of Portland cement clinker. For this purpose, two kinds of clinkers were prepared: one was prepared by IOT; the other was prepared by clay as a reference. The reactivity and burnability of raw meal, mineralogical composition and physical properties of clinker, and hydration characteristic of cement were studied by burnability analysis, differential thermal analysis, X-ray diffraction, and hydration analysis. The results showed that the raw meal containing IOT had higher reactivity and burnability than the raw meal containing clay, and the use of IOT did not affect the formation of characteristic mineralogical phases of Portland cement clinker. Furthermore, the physical and mechanical performance of two cement clinkers were similar. In addition, the use of IOT was found to improve the grindability of clinker and lower the hydration heat of Portland cement. These findings suggest that IOT can replace the clay as alumina-silicate raw material for the preparation of Portland cement clinker. [ABSTRACT FROM AUTHOR]

Background: Most studies have found that osteopontin (OPN) expression level is related to the poor prognosis of gastric cancer. However, few studies have examined the relationship between OPN expression and gastric precancerous diseases, and the potential role of OPN in the formation and development of GC. We investigated the relationships between serum OPN levels and the risks of gastric cancer (GC) and its precancerous disease, to explore the diagnostic efficacy of serum OPN level for GC and atrophic gastritis and its influencing factors. Methods: A total of 1,452 patients were enrolled, including 609 with mild superficial gastritis (SG), 594 with atrophic gastritis (AG) and 249 with GC. The levels of serum OPN and serum Helicobacter pylori IgG antibody were detected by enzyme-linked immunosorbent assay. Results: Serum OPN levels increased from mild SG (1.99±1.91 ng/ml) to AG (2.37±2.27 ng/ml) to GC (5.94±4.52 ng/ml) (P≤0.002), along with increasing severity of gastric disease. OPN levels were significantly higher in patients with GC compared with the non-cancer population (2.17±2.10, P<0.0001). Serum OPN level was positively correlated with age and was higher in men than women, but was not correlated with H. pylori infection status. The area under the receiver operating characteristic curve was 0.805, the optimal cutoff was 2.56 ng/ml and the sensitivity and specificity were 74.3% and 71.8%, respectively, for the ability of serum OPN to discriminate GC. Conclusions: Serum OPN expression was closely related to the risks of GC and AG, and it might be a useful marker for the discrimination of GC. OPN level was positively correlated with age and male sex, but was not affected by H. pylori infection, and it was promoted by smoking and drinking, in patients with mild SG. [ABSTRACT FROM AUTHOR]

Sea cucumbers show high nutritional and medicinal value. Fresh sea cucumber can be degraded after being harvested out of water because of the autolytic enzyme and microorganism in sea cucumber. It can also be degraded even if the enzyme and microorganisms in sea cucumbers lost their activities, which is known as non-enzymatic degradation. Non-enzymatic degradation of the body wall gel is an important factor restricting the development of sea cucumber products. The high hydrostatic pressure (HP) technology is a novel method which shows various advantages. In order to investigate the mechanism of stability and degradation of sea cucumber body wall under high hydrostatic pressure (HPSC), the sea cucumbers were treated with high hydrostatic pressure (650 MPa) for 40 min. The changes of textural parameters, histological features of collagen fibers, moisture status, moisture distribution, and biochemical parameters were explored by accelerated destruction test, which was performed at 37׎ and the samples were stored for 30 days at this condition. The results showed that the hardness, chewiness, restorability and other texture profile analysis (TPA) parameters had a significant downward trend during storage (P<0.05). The hardness of HPSC decreased sharply from 840.50 to 23.33 after storage for 30 days. Besides this, the elastic modulus, viscous modulus and other rheological parameters of HPSC also decreased significantly (P<0.05). The elastic modulus E1 decreased from 2.24×104 N/m2 to 0.40×104 N/m2. But the descending rate of these parameters was much lower than that of the sea cucumber treated by high pressure and high temperature, which indicates that high hydrostatic pressure can put off the degradation. The collagen fiber of HPSC had a three-dimensional network structure according to the Van Gieson stain image, similar to that of fresh sea cucumber. This indicated that the thermal gel structure did not form in collagen fiber under high hydrostatic pressure treatment. In addition, the collagen fiber was degraded significantly after stored for 20 days. Longitudinal relaxation time and transverse relaxation time-weighted imaging showed that both the combined water with a short relaxation time and the free water with a long relaxation time distributed evenly during the early storage time. After 20-day storage, the combined water transformed into the free water, which resulted in the significant increase of water activity (P<0.05), and this was due to the structure destruction of sea cucumber body wall. The level of ammonium nitrogen, free hydroxyproline, and ƒÃ-amino in the HPSC had a significant increase during the storage (P<0.05), indicating that the collagen of sea cucumber body wall had been degraded. Therefore, the gel deterioration of sea cucumber body wall was largely due to the breakage of collagen fiber, the conversion between the bound water and free water, and protein degradation. Previous studies have demonstrated that sea cucumbers treated by high temperature and high pressure had the self-degradation phenomenon during storage, and temperature is an important factor leading to the degradation of sea cucumber body wall. But the results of this research showed that the temperature was not the only factor causing the degradation of sea cucumber body wall, and sea cucumbers treated by non-thermal high pressure can also be degraded during the storage time. For this reason, other efficient measures that can inhibit the self-degradation should be taken in order to extend the shelf life of sea cucumber. [ABSTRACT FROM AUTHOR]