The granulation behavior of iron ores is essential for subsequent parameter optimization and efficient granulation, especially under changing material conditions. In this study, the effects of surface properties and p...The granulation behavior of iron ores is essential for subsequent parameter optimization and efficient granulation, especially under changing material conditions. In this study, the effects of surface properties and particle size were analyzed using a laboratory granulation method; an estimation of the granulation of sintering blends was subsequently conducted for the base ores. Circularity and porosity were observed to negatively affect the granulation of iron ores, whereas wettability positively affected the granulation and was the most influential factor, indicating that wetting of iron ores is desirable during granulation. When iron ores with complex size distributions were granulated, the equivalent surface area was the main influencing factor for coarse particles larger than 1 mm and the ratio of adhering fines to intermediates was the main factor for fine particles smaller than 1 mm. By combining the granulation of coarse and fine particles with their proportioning, we proposed a calculation method for estimating the granulation ability of sintering blends. Good verification was demonstrated with the designed schemes. The results suggest that the developed method is effective for predicting the granulation of iron ore mixtures.展开更多
Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size o...Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size on the assimilation characteristics and fluidity of liquid phase of five different iron ores were analyzed in this study. Next, the mechanism based on the reaction between gangues and sintering mate- dais was unraveled. The results show that, as the SiO2 levels increase in the iron ores, the lowest assimilation temperature （LAT） decreases, whereas the index of fluidity of liquid phase （IFL） increases. Below 1.5wt%, Al2O3 benefits the assimilation reaction, but higher concentra- tions proved detrimental. Larger quartz particles increase the SiO2 levels at the local reaction interface between the iron ore and CaO, thereby reducing the LAT. Quartz-gibbsite is more conductive to assimilation than kaolin. Quartz-gibbsite and kaolin gangues encourage the forma- tion of liquid-phase low-Al2O3-SFCA with high IFL and high-Al2O3-SFCA with low IFL, respectively.展开更多
The appropriate content and distribution of sinter moisture play an important role in the granulation of iron ores. In this study, the effects of porosity, size distribution, and particle shape on the water absorption...The appropriate content and distribution of sinter moisture play an important role in the granulation of iron ores. In this study, the effects of porosity, size distribution, and particle shape on the water absorption rate （WAR） of four types of iron ores were analyzed by using the immersion method and capillary water absorption method. In addition, the mechanism underlying the water absorption process in iron ores was unraveled. It is found that the WARs of iron ores decrease quickly with the increase in water absorption time at the initial stages of water absorption. With further increase in absorption time, the WARs decrease gradually, until near 0. Iron ores with higher porosity, smaller particle size, and plate-like structure have the higher WARs. Compared with pores in the single-particle iron ore, voids among particles in the multi-particle iron oxide play an important role at the initial stages of water absorption. The water absorption mechanism of all single-particle and multi-particle iron ores analyzed in this study includes four steps, wherein the first three steps play a significant role in the sintering pro-cess.展开更多
Sinter body strength, which reflects the strength of sinter, plays an important role in the improvement of sinter. In this study, the sinter body strengths of iron ores were measured using a microsintering method. The...Sinter body strength, which reflects the strength of sinter, plays an important role in the improvement of sinter. In this study, the sinter body strengths of iron ores were measured using a microsintering method. The relationship between the chemical composition and sinter body strength was discussed. Moreover, sinter-pot tests were performed. The effects of sinter body strength on the sintering indexes were then elucidated, and the bottom limit of sinter body strength of blending ores was confirmed. In the results, the compressive strengths（CSs） of iron ores are observed to decrease with the increasing of the contents of loss on ignition（LOI）, SiO 2, and Al2O3; however, LOI of less than 3wt% does not substantially influence the CSs of fine ores. In the case of similar mineral composition, the porosity, in particular, the ratio between the number of large pores and the total number of pores, strongly influences the sinter body strength. With an increase of the blending-ore CSs used in sinter-pot tests, the yield, productivity, and tumbler strength increase, and the solid fuel consumption decreases. The CSs of the blending ores only slightly affect the sintering time. The CS bottom limit of the blending ores is 310 N. When the CSs of the blending ores increase by 10%, the yield, productivity, and tumbler index increase by 1.9%, 2.8%, and 2.0%, respectively, and the solid fuel consumption decreases by 1.9%.展开更多
Objective To evaluate the efifcacy and safety of traditional Chinese medicine (TCM) combined with Western medicine in the treatment of patients with common hand, foot and mouth disease (HFMD) by conducting a prospecti...Objective To evaluate the efifcacy and safety of traditional Chinese medicine (TCM) combined with Western medicine in the treatment of patients with common hand, foot and mouth disease (HFMD) by conducting a prospective, controlled, and randomized trial. Methods A total of 452 patients with common HFMD were randomly assigned to receive Western medicine alone (n=220) or combined with TCM (Reduning or Xiyanping injections) (n=232). The primary outcome was the incidence rate of rash/herpes disappearance within 5 days, while secondary outcomes included the incidence rate for fever, cough, lethargy, agitation, and vomiting clearance within 5 days. Results The rash/herpes disappearance rate was 45.5% (100/220) in Western medicine therapy group, and 67.2% (156/232) in TCM and Western medicine combined therapy group, with significant difference (P<0.001). Moreover, TCM remarkably increased the incidence rate of secondary disappearance, which was 56.4%in Western medicine therapy group and 71.4%in TCM and Western medicine combined therapy group (P=0.001). No drug-related adverse events were observed. Conclusions It’s suggested that the integrative TCM and Western medicine therapy achieved a better therapeutic efficacy. TCM may become an important complementary therapy on relieving the symptoms of HFMD.展开更多
This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with des...This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, respectively.The height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.展开更多
BACKGROUND Suppurative oesophagitis is a diffuse inflammation of the oesophagus characterized by suppurative exudate or pus formation.Suppurative infections can affect any part of the gastrointestinal tract,most commo...BACKGROUND Suppurative oesophagitis is a diffuse inflammation of the oesophagus characterized by suppurative exudate or pus formation.Suppurative infections can affect any part of the gastrointestinal tract,most commonly the stomach,with inflammation involving the entire gastric cavity.However,cases extending beyond the cardia or pylorus and involving the oesophagus,small intestine,and colon are rare.Usually such cases are discovered during surgery or autopsy.CASE SUMMARY We report a rare case of acute suppurative oesophagitis.A 57-year-old man presented at the Emergency Department of our hospital with fever and productive cough.The patient had a significant history of lower oesophageal mucosal frostbite.He was successfully diagnosed and treated with repeated gastroscopy,appropriate antibiotics,and innovative symptomatic treatment.CONCLUSION Early diagnosis and appropriate treatment of acute suppurative oesophagitis are critical.Nutritional support,postural drainage,and other symptomatic treatments must be considered.展开更多
Objective: To study the protective effect of ruanganyin on the liver of HBV transgenic mice. Methods: 50 half HBV transgenic mice, male and female, were randomly divided into treatment group (high, medium and low dose...Objective: To study the protective effect of ruanganyin on the liver of HBV transgenic mice. Methods: 50 half HBV transgenic mice, male and female, were randomly divided into treatment group (high, medium and low dose Ruanganyin), model group, positive control group (entecavir dispersible tablet) and 10 non HBV transgenic mice as blank control. The mice were killed after 4 weeks of drug intervention.The serum levels of ALT, AST, TBIL, LN, HA, IV-C and PCIII were observed. Results: (1) compared with the blank control group, the ALT,AST and TBIL levels in the model group were significantly higher than those in the blank control group (P < 0.01);compared with the model group, the ALT, AST and TBIL levels in the high-dose group of ruanganyin after treatment were significantly lower than those in the model group (P<0.01/P<0.05);the ALT, AST and TBIL levels in the positive control group were lower than those in the model group (P<0.01/P<0.05) There was no significant difference in ALT, AST and TBIL levels between the two groups (P>0.05). (2) Compared with the blank control group, the level of LN, HA, IV-C and PCIII in the model group was significantly higher than that in the blank control group (P<0.01);compared with the model group, the level of LN, HA and IV-C in the high-dose group and the positive control group after treatment was significantly lower than that in the model group (P<0.01);the level of PCIII in the high-dose group and the positive control group after treatment was significantly lower than that in the model group (P<0.01);There was no significant difference in LN, HA, IV-C and PCIII levels between the two groups (P> 0.05). Conclusion: Chinese medicine Ruanganyin has the effects of protecting liver, reducing enzyme and anti fibrosis, but its mechanism of anti fibrosis needs further study.展开更多
Background Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awarenes...Background Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awareness and effective treat-ments, to further standardize and strengthen the clinical management and to reduce the mortality of HFMD, the guidelines for diagnosis and treatment have been developed. Methods National Health Commission of China assembled an expert committee for a revision of the guidelines. The com-mittee included 33 members who are specialized in diagnosis and treatment of HFMD. Results Early recognition of severe cases is utmost important in diagnosis and treatment of patients with HFMD. The key to diagnosis and treatment of severe cases lies in the timely and accurate recognition of stages 2 and 3 of HFMD, in order to stop progression to stage 4. Clinicians should particularly pay attention to those EV-A71 cases in children aged less than 3 years, and those with disease duration less than 3 days. The following indicators should alert the clinician of possible deterioration and impending critical disease: (1) persistent hyperthermia;(2) involvement of nervous system;(3) worsening respiratory rate and rhythm;(4) circulatory dysfunction;(5) elevated peripheral WBC count;(6) elevated blood glucose and (7) elevated blood lactic acid. For treatment, most mild cases can be treated as outpatients. Patients should be isolated to avoid cross-infection. Intense treatment modalities should be given for those severe cases. Conclusion The guidelines can provide systematic guidance on the diagnosis and management of HFMD.展开更多
Wheat stripe rust,due to infection by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease that causes significant global grain yield losses.Yr36,which encodes Wheat Kinase START1(WKS1),is an effec-tive hig...Wheat stripe rust,due to infection by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease that causes significant global grain yield losses.Yr36,which encodes Wheat Kinase START1(WKS1),is an effec-tive high-temperature adult-plant resistance gene and confers resistance to a broad spectrum of Pst races.We previously showed that WKS1 phosphorylates the thylakoid ascorbate peroxidase protein and reduces its ability to detoxify peroxides,which may contribute to the accumulation of reactive oxygen species(ROS).WKS1-mediated Pst resistance is accompanied by leaf chlorosis in Pst-infected regions,but the un-derlying mechanisms remain elusive.Here,we show that WKS1 interacts with and phosphorylates PsbO,an extrinsic member of photosystem Ⅱ(PS Ⅱ),to reduce photosynthesis,regulate leaf chlorosis,and confer Pst resistance.A point mutation in PsbO-A1 or reduction in its transcript levels by RNA interference resulted in chlorosis and reduced Pst sporulation.Biochemical analyses revealed that WKS1 phosphorylates PsbO at two conserved amino acids involved in physical interactions with PS Ⅱ and reduces the binding affinity of PsbO with PS Ⅱ.Presumably,phosphorylated PsbO proteins dissociate from the PS Ⅱ complex and then un-dergo rapid degradation by cysteine and aspartic proteases.Taken together,these results demonstrate that perturbations of wheat PsbO by point mutation or phosphorylation by WKS1 reduce the rate of photo-synthesis and delay the growth of Pst pathogen before the induction of ROS.展开更多
The South China Sea(SCS)is the largest extensional basin in the western Pacific and was formed after rifting of the Euro-Asian continental margin.The nature of its underlying mantle remains enigmatic due to the lack o...The South China Sea(SCS)is the largest extensional basin in the western Pacific and was formed after rifting of the Euro-Asian continental margin.The nature of its underlying mantle remains enigmatic due to the lack of sampling of the seafloor’s igneous crust.The International Ocean Discovery Program Expedition 349 cored seafloor basalts of the southwestern(Site U1433)and eastern(Site U1431)SCS sub-basins.The recovered basalt samples exhibit different source lithologies and geochemistries.The Mg isotopic compositions of seafloor basalts from these sites were investigated to elucidate the origin of this large-scale mantle inhomogeneity.Results indicate that the Site U1431 basalts have a mantlelike averageδ^(26)Mg value of-0.27‰±0.06‰(2 SD;n=10).Together with inhomogeneous Sr-Nd-Pb-Hf isotopic compositions,the Site U1433 basalts have an averageδ^(26)Mg value(-0.20‰±0.06‰;2 SD;n=8)higher than those of the Site U1431 basalts and normal mantle.Their heavier Mg isotopic compositions and low206 Pb/204 Pb ratios(17.7)indicate that the Site U1433 basalts were affected by the re-melting of detached continental-arc lithosphere in the sub-ridge mantle.The coupling of Mg and Sr-Nd isotopes provides robust evidence that the mantle-likeδ^(26)Mg values of the Site U1431 basalts resulted from mixing between detached continental arc lithosphere and the nearby Hainan plume,with respective supra-and sub-normalδ^(26)Mg values.From the perspective of Mg isotope,the mantles of the southwestern and eastern sub-basins are compositionally inhomogeneous,with their mantle evolutionary histories being distinct.展开更多
A theoretical investigation on the pH-induced switching of mixed polyelectrolyte brushes was performed by using a molecular theory. The results indicate that the switching properties of mixed polyelectrolyte brushes a...A theoretical investigation on the pH-induced switching of mixed polyelectrolyte brushes was performed by using a molecular theory. The results indicate that the switching properties of mixed polyelectrolyte brushes are dependent on the pH values. At low pH, negatively charged chains adopt a compact conformation on the bottom of the brush while positively charged chains are highly stretched away from the surface. At high pH values, the inverse transformation takes place. The role of pH determining the polymer chains conformation and charge behavior of mixed polyelectrolyte brushes was analyzed. It is found that there exists a mechanism for reducing strong electrostatic repulsions： stretching of the chains. The H＋ and OH- units play a more important role as counterions of the charged polymers do. The collapse of the polyelectrolyte chains for different pH values could be attributed to the screening of the electrostatic interactions and the counterion-mediated attractive interaction along the chains.展开更多
Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote ...Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe- troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids （11.2 mg/L） increased the removal efficiency of crude oil from 17.7% （in the absence of rham- nolipids） to 63%. At 25 ~C, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment （22.5 mg/L） for 24 h at 20℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interfacial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater.展开更多
Crystal patterns in ultrathin films of six poly（ethylene oxide） fractions with molecular weights from 25000 to 932000 g/mol were characterized within crystallization temperature range from 20 ℃to 60℃. Labyrinthine...Crystal patterns in ultrathin films of six poly（ethylene oxide） fractions with molecular weights from 25000 to 932000 g/mol were characterized within crystallization temperature range from 20 ℃to 60℃. Labyrinthine, dendritic and faceted crystal patterns were observed in different temperature ranges, and then labyrinthine-to-dendritic and dendritic-to- faceted transition temperatures T_L-D and T_D-F were quantitatively identified. Their molecular weight dependences are T_L-D（M_w） = T_L-D（∞） -K_L-D/M_w, where T_L-D（∞） = 38.2 ℃ and K_L-D = 253000 ℃.g/mol and T_D-F（M_w） = T_D-F（∞） -K_D-F/M_w, where T_D-F（∞） = 54.7 ℃ and K_D-F= 27000 ℃.g/mol. Quasi two-dimensional blob models were proposed to provide empirical explanations of the molecular weight dependences. The labyrinthine-to-dendritic transition is attributed to a molecular diffusion process change from a local-diffusion to diffusion-limited-aggregation （DLA） and a polymer chain with M_w ≈253000 g/mol within a blob can join crystals independently. The dendritic-to-faceted transition is attributed to a turnover of the pattern formation mechanism from DLA to crystallization control, and a polymer chain with a M_w ≈27000 g/tool as an independent blob crosses to a depletion zone to join crystals. These molecular weight dependences reveal a macromolecular effect on the crystal pattern formation and selection of crystalline polymers.展开更多
Background:Endotoxin tolerance(ET)is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide(LPS)leads to dramatically elevated survival.Accumulating evidence has shown that peripher...Background:Endotoxin tolerance(ET)is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide(LPS)leads to dramatically elevated survival.Accumulating evidence has shown that peripheral T cells contribute to the induction of ET.However,what happens to T cell development in the thymus under ET conditions remains unclear.The purpose of this study was to analyze the alterations in thymocyte populations(double-positive[DP]and single-positive[SP]cells)under ET conditions.Methods:Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups:a group examined 72 h after LPS injection(72-h group)and a group examined 8 days after LPS injection(8-day group).Injection of phosphate-buffered saline was used as a control(control group).Changes in thymus weight,cell counts,and morphology were detected in the three groups.Moreover,surface molecules such as CD4,CD8,CD44,CD69,and CD62L were analyzed using flow cytometry.Furthermore,proliferation,apoptosis,cytokine production,and extracellular signal-regulated kinase(ERK)pathway signaling were analyzed in thymocyte populations.The polymorphism and length of the T-cell receptor(TCR)P chain complementarity-determining region 3(CDR3)were analyzed using capillary electrophoresis DNA laser scanning analysis(ABI 3730).Results:Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET.Moreover,the proportions of DP cells(control:72.130±4.074,72-h:10.600±3.517,8-day:84.770±2.228),CD4+SP cells(control:15.770±4.419,72-h:44.670±3.089,8-day:6.367±0.513),and CD8+SP cells(control:7.000±1.916,72-h:34.030±3.850,8-day:5.133±0.647)were obviously different at different stages of ET.The polymorphism and length of TCR β chain CDR3 also changed obviously,indicating the occurrence of TCR rearrangement and thymocyte diversification.Further analysis showed that the expression of surface molecules,including CD44,CD69,and CD62L,on thymocyte populations(DP and SP cells)were changed to different degrees.Finally,the proliferation,apoptosis,cytokine production,and ERK pathway signaling of thymocyte populations were changed significantly.Conclusion:These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.展开更多
Brown adipose tissue(BAT)plays a key role in thermogenesis during acute cold exposure.However,it remains unclear how BAT is prepared to rapidly turn on thermogenic genes.Here,we show that damage-specific DNA binding p...Brown adipose tissue(BAT)plays a key role in thermogenesis during acute cold exposure.However,it remains unclear how BAT is prepared to rapidly turn on thermogenic genes.Here,we show that damage-specific DNA binding protein 1(DDB1)mediates the rapid transcription of thermogenic genes upon acute cold exposure.Adipose-or BAT-specific Ddb1 knockout mice show severely whitened BAT and significantly decreased expression of thermogenic genes.These mice develop hypothermia when subjected to acute cold exposure at 4℃ and partial lipodystrophy on a high-fat diet due to deficiency in fatty acid oxidation.Mechanistically,DDB1 binds the promoters of Ucp1 and Ppargc1a and recruits positive transcriptional elongation factor b(P-TEFb)to release promoter-proximally paused RNA polymerase II(Pol II),thereby enabling rapid and synchronized transcription of thermogenic genes upon acute cold exposure.Our findings have thus provided a regulatory mechanism of how BAT is prepared to respond to acute cold challenge.展开更多
基金The financial supports of the National Natural Science Foundation of China (U1260202)the Fundamental Research Funds for the Central Universities of China (FRF-MP-12-003B)
文摘The granulation behavior of iron ores is essential for subsequent parameter optimization and efficient granulation, especially under changing material conditions. In this study, the effects of surface properties and particle size were analyzed using a laboratory granulation method; an estimation of the granulation of sintering blends was subsequently conducted for the base ores. Circularity and porosity were observed to negatively affect the granulation of iron ores, whereas wettability positively affected the granulation and was the most influential factor, indicating that wetting of iron ores is desirable during granulation. When iron ores with complex size distributions were granulated, the equivalent surface area was the main influencing factor for coarse particles larger than 1 mm and the ratio of adhering fines to intermediates was the main factor for fine particles smaller than 1 mm. By combining the granulation of coarse and fine particles with their proportioning, we proposed a calculation method for estimating the granulation ability of sintering blends. Good verification was demonstrated with the designed schemes. The results suggest that the developed method is effective for predicting the granulation of iron ore mixtures.
基金financially supported by the Fundamental Research Funds for the Central Universities of China(No.FRF-MP-12-003B)
文摘Gangue existing states largely affect the high-temperature characteristics of iron ores. Using a micro-sintering method and scan- ning electron microscopy, the effects of gangue content, gangue type, and gangue size on the assimilation characteristics and fluidity of liquid phase of five different iron ores were analyzed in this study. Next, the mechanism based on the reaction between gangues and sintering mate- dais was unraveled. The results show that, as the SiO2 levels increase in the iron ores, the lowest assimilation temperature （LAT） decreases, whereas the index of fluidity of liquid phase （IFL） increases. Below 1.5wt%, Al2O3 benefits the assimilation reaction, but higher concentra- tions proved detrimental. Larger quartz particles increase the SiO2 levels at the local reaction interface between the iron ore and CaO, thereby reducing the LAT. Quartz-gibbsite is more conductive to assimilation than kaolin. Quartz-gibbsite and kaolin gangues encourage the forma- tion of liquid-phase low-Al2O3-SFCA with high IFL and high-Al2O3-SFCA with low IFL, respectively.
基金financially supported by the National Natural Science Foundation of China(No.U1260202)the Fundamental Research Funds for the Central Universities(No.FRF-MP-12-003B)
文摘The appropriate content and distribution of sinter moisture play an important role in the granulation of iron ores. In this study, the effects of porosity, size distribution, and particle shape on the water absorption rate （WAR） of four types of iron ores were analyzed by using the immersion method and capillary water absorption method. In addition, the mechanism underlying the water absorption process in iron ores was unraveled. It is found that the WARs of iron ores decrease quickly with the increase in water absorption time at the initial stages of water absorption. With further increase in absorption time, the WARs decrease gradually, until near 0. Iron ores with higher porosity, smaller particle size, and plate-like structure have the higher WARs. Compared with pores in the single-particle iron ore, voids among particles in the multi-particle iron oxide play an important role at the initial stages of water absorption. The water absorption mechanism of all single-particle and multi-particle iron ores analyzed in this study includes four steps, wherein the first three steps play a significant role in the sintering pro-cess.
基金financially supported by the Fundamental Research Funds for the Central Universities of China (No. FRF-IC-14-006)
文摘Sinter body strength, which reflects the strength of sinter, plays an important role in the improvement of sinter. In this study, the sinter body strengths of iron ores were measured using a microsintering method. The relationship between the chemical composition and sinter body strength was discussed. Moreover, sinter-pot tests were performed. The effects of sinter body strength on the sintering indexes were then elucidated, and the bottom limit of sinter body strength of blending ores was confirmed. In the results, the compressive strengths（CSs） of iron ores are observed to decrease with the increasing of the contents of loss on ignition（LOI）, SiO 2, and Al2O3; however, LOI of less than 3wt% does not substantially influence the CSs of fine ores. In the case of similar mineral composition, the porosity, in particular, the ratio between the number of large pores and the total number of pores, strongly influences the sinter body strength. With an increase of the blending-ore CSs used in sinter-pot tests, the yield, productivity, and tumbler strength increase, and the solid fuel consumption decreases. The CSs of the blending ores only slightly affect the sintering time. The CS bottom limit of the blending ores is 310 N. When the CSs of the blending ores increase by 10%, the yield, productivity, and tumbler index increase by 1.9%, 2.8%, and 2.0%, respectively, and the solid fuel consumption decreases by 1.9%.
基金supported by State Administration of Traditional Chinese Medicine of China Research Project (200907001-3)
文摘Objective To evaluate the efifcacy and safety of traditional Chinese medicine (TCM) combined with Western medicine in the treatment of patients with common hand, foot and mouth disease (HFMD) by conducting a prospective, controlled, and randomized trial. Methods A total of 452 patients with common HFMD were randomly assigned to receive Western medicine alone (n=220) or combined with TCM (Reduning or Xiyanping injections) (n=232). The primary outcome was the incidence rate of rash/herpes disappearance within 5 days, while secondary outcomes included the incidence rate for fever, cough, lethargy, agitation, and vomiting clearance within 5 days. Results The rash/herpes disappearance rate was 45.5% (100/220) in Western medicine therapy group, and 67.2% (156/232) in TCM and Western medicine combined therapy group, with significant difference (P<0.001). Moreover, TCM remarkably increased the incidence rate of secondary disappearance, which was 56.4%in Western medicine therapy group and 71.4%in TCM and Western medicine combined therapy group (P=0.001). No drug-related adverse events were observed. Conclusions It’s suggested that the integrative TCM and Western medicine therapy achieved a better therapeutic efficacy. TCM may become an important complementary therapy on relieving the symptoms of HFMD.
基金supported by National High-tech R&D Program of China(No.2012AA050905)
文摘This paper proposes a design of passive cooling system for CPR1000 spent fuel pool(SFP). Our design can effectively manage the SFP temperature not to exceed80 C. Then the transient analysis of the CPR1000 SFP with designed passive cooling system is carried out in station blackout(SBO) accident by the best-estimate thermal-hydraulic system code RELAP5. The simulation results show that to maintain the temperature of CPR1000 SFP under 80 C, the numbers of the SFP and air cooling heat exchangers tubes are 6627 and 19 086, respectively.The height difference between the bottom of the air cooling heat exchanger and the top of the SFP heat exchanger is3.8 m. The number of SFP heat exchanger tubes decreases as the height difference increases, while the number of the air cooling heat exchanger tubes increases. The transient analysis results show that after the SBO accident, a stable natural cooling circulation is established. The surface temperature of CPR1000 SFP increases continually until 80 C, which indicates that the design of the passive air cooling system for CPR1000 SFP is capable of removing the decay heat to maintain the temperature of the SFP around 80 C after losing the heat sink.
基金Supported by the Fund of Spring Wind Plan of Tianjin First Central Hospital,No.TFCHCF201814.
文摘BACKGROUND Suppurative oesophagitis is a diffuse inflammation of the oesophagus characterized by suppurative exudate or pus formation.Suppurative infections can affect any part of the gastrointestinal tract,most commonly the stomach,with inflammation involving the entire gastric cavity.However,cases extending beyond the cardia or pylorus and involving the oesophagus,small intestine,and colon are rare.Usually such cases are discovered during surgery or autopsy.CASE SUMMARY We report a rare case of acute suppurative oesophagitis.A 57-year-old man presented at the Emergency Department of our hospital with fever and productive cough.The patient had a significant history of lower oesophageal mucosal frostbite.He was successfully diagnosed and treated with repeated gastroscopy,appropriate antibiotics,and innovative symptomatic treatment.CONCLUSION Early diagnosis and appropriate treatment of acute suppurative oesophagitis are critical.Nutritional support,postural drainage,and other symptomatic treatments must be considered.
文摘Objective: To study the protective effect of ruanganyin on the liver of HBV transgenic mice. Methods: 50 half HBV transgenic mice, male and female, were randomly divided into treatment group (high, medium and low dose Ruanganyin), model group, positive control group (entecavir dispersible tablet) and 10 non HBV transgenic mice as blank control. The mice were killed after 4 weeks of drug intervention.The serum levels of ALT, AST, TBIL, LN, HA, IV-C and PCIII were observed. Results: (1) compared with the blank control group, the ALT,AST and TBIL levels in the model group were significantly higher than those in the blank control group (P < 0.01);compared with the model group, the ALT, AST and TBIL levels in the high-dose group of ruanganyin after treatment were significantly lower than those in the model group (P<0.01/P<0.05);the ALT, AST and TBIL levels in the positive control group were lower than those in the model group (P<0.01/P<0.05) There was no significant difference in ALT, AST and TBIL levels between the two groups (P>0.05). (2) Compared with the blank control group, the level of LN, HA, IV-C and PCIII in the model group was significantly higher than that in the blank control group (P<0.01);compared with the model group, the level of LN, HA and IV-C in the high-dose group and the positive control group after treatment was significantly lower than that in the model group (P<0.01);the level of PCIII in the high-dose group and the positive control group after treatment was significantly lower than that in the model group (P<0.01);There was no significant difference in LN, HA, IV-C and PCIII levels between the two groups (P> 0.05). Conclusion: Chinese medicine Ruanganyin has the effects of protecting liver, reducing enzyme and anti fibrosis, but its mechanism of anti fibrosis needs further study.
文摘Background Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awareness and effective treat-ments, to further standardize and strengthen the clinical management and to reduce the mortality of HFMD, the guidelines for diagnosis and treatment have been developed. Methods National Health Commission of China assembled an expert committee for a revision of the guidelines. The com-mittee included 33 members who are specialized in diagnosis and treatment of HFMD. Results Early recognition of severe cases is utmost important in diagnosis and treatment of patients with HFMD. The key to diagnosis and treatment of severe cases lies in the timely and accurate recognition of stages 2 and 3 of HFMD, in order to stop progression to stage 4. Clinicians should particularly pay attention to those EV-A71 cases in children aged less than 3 years, and those with disease duration less than 3 days. The following indicators should alert the clinician of possible deterioration and impending critical disease: (1) persistent hyperthermia;(2) involvement of nervous system;(3) worsening respiratory rate and rhythm;(4) circulatory dysfunction;(5) elevated peripheral WBC count;(6) elevated blood glucose and (7) elevated blood lactic acid. For treatment, most mild cases can be treated as outpatients. Patients should be isolated to avoid cross-infection. Intense treatment modalities should be given for those severe cases. Conclusion The guidelines can provide systematic guidance on the diagnosis and management of HFMD.
基金This research is supported by the National Key R&D Program of China(2016YFD0100500)the National Science Foundation of China(NSFC)(31772146,31972350)for J.G.J.D.acknowledges support from BARD and the Howard Hughes Medical Institute.We thank an open project for support from the National Key Laboratory of Wheat and Maize Crop Science,Henan Agricultural University.
文摘Wheat stripe rust,due to infection by Puccinia striiformis f.sp.tritici(Pst),is a devastating disease that causes significant global grain yield losses.Yr36,which encodes Wheat Kinase START1(WKS1),is an effec-tive high-temperature adult-plant resistance gene and confers resistance to a broad spectrum of Pst races.We previously showed that WKS1 phosphorylates the thylakoid ascorbate peroxidase protein and reduces its ability to detoxify peroxides,which may contribute to the accumulation of reactive oxygen species(ROS).WKS1-mediated Pst resistance is accompanied by leaf chlorosis in Pst-infected regions,but the un-derlying mechanisms remain elusive.Here,we show that WKS1 interacts with and phosphorylates PsbO,an extrinsic member of photosystem Ⅱ(PS Ⅱ),to reduce photosynthesis,regulate leaf chlorosis,and confer Pst resistance.A point mutation in PsbO-A1 or reduction in its transcript levels by RNA interference resulted in chlorosis and reduced Pst sporulation.Biochemical analyses revealed that WKS1 phosphorylates PsbO at two conserved amino acids involved in physical interactions with PS Ⅱ and reduces the binding affinity of PsbO with PS Ⅱ.Presumably,phosphorylated PsbO proteins dissociate from the PS Ⅱ complex and then un-dergo rapid degradation by cysteine and aspartic proteases.Taken together,these results demonstrate that perturbations of wheat PsbO by point mutation or phosphorylation by WKS1 reduce the rate of photo-synthesis and delay the growth of Pst pathogen before the induction of ROS.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22050101 and XDB42020302)the National Natural Science Foundation of China(91858206 and 41876040)+2 种基金the Laboratory for Marine GeologyQingdao Pilot National Laboratory for Marine Science and Technology(MGQNLM-TD201806)the Taishan Scholars Program of Shandong Province(tsqn201909157)。
文摘The South China Sea(SCS)is the largest extensional basin in the western Pacific and was formed after rifting of the Euro-Asian continental margin.The nature of its underlying mantle remains enigmatic due to the lack of sampling of the seafloor’s igneous crust.The International Ocean Discovery Program Expedition 349 cored seafloor basalts of the southwestern(Site U1433)and eastern(Site U1431)SCS sub-basins.The recovered basalt samples exhibit different source lithologies and geochemistries.The Mg isotopic compositions of seafloor basalts from these sites were investigated to elucidate the origin of this large-scale mantle inhomogeneity.Results indicate that the Site U1431 basalts have a mantlelike averageδ^(26)Mg value of-0.27‰±0.06‰(2 SD;n=10).Together with inhomogeneous Sr-Nd-Pb-Hf isotopic compositions,the Site U1433 basalts have an averageδ^(26)Mg value(-0.20‰±0.06‰;2 SD;n=8)higher than those of the Site U1431 basalts and normal mantle.Their heavier Mg isotopic compositions and low206 Pb/204 Pb ratios(17.7)indicate that the Site U1433 basalts were affected by the re-melting of detached continental-arc lithosphere in the sub-ridge mantle.The coupling of Mg and Sr-Nd isotopes provides robust evidence that the mantle-likeδ^(26)Mg values of the Site U1431 basalts resulted from mixing between detached continental arc lithosphere and the nearby Hainan plume,with respective supra-and sub-normalδ^(26)Mg values.From the perspective of Mg isotope,the mantles of the southwestern and eastern sub-basins are compositionally inhomogeneous,with their mantle evolutionary histories being distinct.
基金financially supported by the National Natural Science Foundation of China(Nos.21264016 and 11265015)the General Foundation of Yi Li Normal University(No.2013YSYB17)
文摘A theoretical investigation on the pH-induced switching of mixed polyelectrolyte brushes was performed by using a molecular theory. The results indicate that the switching properties of mixed polyelectrolyte brushes are dependent on the pH values. At low pH, negatively charged chains adopt a compact conformation on the bottom of the brush while positively charged chains are highly stretched away from the surface. At high pH values, the inverse transformation takes place. The role of pH determining the polymer chains conformation and charge behavior of mixed polyelectrolyte brushes was analyzed. It is found that there exists a mechanism for reducing strong electrostatic repulsions： stretching of the chains. The H＋ and OH- units play a more important role as counterions of the charged polymers do. The collapse of the polyelectrolyte chains for different pH values could be attributed to the screening of the electrostatic interactions and the counterion-mediated attractive interaction along the chains.
基金Project (No. 56310503014) supported by the Department of Education of Zhejiang Province, China
文摘Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra- ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe- troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids （11.2 mg/L） increased the removal efficiency of crude oil from 17.7% （in the absence of rham- nolipids） to 63%. At 25 ~C, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment （22.5 mg/L） for 24 h at 20℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interfacial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater.
基金financially supported by the National Science Foundation of China(No.20874053)
文摘Crystal patterns in ultrathin films of six poly（ethylene oxide） fractions with molecular weights from 25000 to 932000 g/mol were characterized within crystallization temperature range from 20 ℃to 60℃. Labyrinthine, dendritic and faceted crystal patterns were observed in different temperature ranges, and then labyrinthine-to-dendritic and dendritic-to- faceted transition temperatures T_L-D and T_D-F were quantitatively identified. Their molecular weight dependences are T_L-D（M_w） = T_L-D（∞） -K_L-D/M_w, where T_L-D（∞） = 38.2 ℃ and K_L-D = 253000 ℃.g/mol and T_D-F（M_w） = T_D-F（∞） -K_D-F/M_w, where T_D-F（∞） = 54.7 ℃ and K_D-F= 27000 ℃.g/mol. Quasi two-dimensional blob models were proposed to provide empirical explanations of the molecular weight dependences. The labyrinthine-to-dendritic transition is attributed to a molecular diffusion process change from a local-diffusion to diffusion-limited-aggregation （DLA） and a polymer chain with M_w ≈253000 g/mol within a blob can join crystals independently. The dendritic-to-faceted transition is attributed to a turnover of the pattern formation mechanism from DLA to crystallization control, and a polymer chain with a M_w ≈27000 g/tool as an independent blob crosses to a depletion zone to join crystals. These molecular weight dependences reveal a macromolecular effect on the crystal pattern formation and selection of crystalline polymers.
基金the Project of the Guizhou Provincial Department of Science and Technology(No.QKH-JC-2018-1428)the National Natural Science Foundation of China(No.31760258)the Guizhou Province Graduate Research Fund(No.YJSCXJH-2020-093).
文摘Background:Endotoxin tolerance(ET)is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide(LPS)leads to dramatically elevated survival.Accumulating evidence has shown that peripheral T cells contribute to the induction of ET.However,what happens to T cell development in the thymus under ET conditions remains unclear.The purpose of this study was to analyze the alterations in thymocyte populations(double-positive[DP]and single-positive[SP]cells)under ET conditions.Methods:Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups:a group examined 72 h after LPS injection(72-h group)and a group examined 8 days after LPS injection(8-day group).Injection of phosphate-buffered saline was used as a control(control group).Changes in thymus weight,cell counts,and morphology were detected in the three groups.Moreover,surface molecules such as CD4,CD8,CD44,CD69,and CD62L were analyzed using flow cytometry.Furthermore,proliferation,apoptosis,cytokine production,and extracellular signal-regulated kinase(ERK)pathway signaling were analyzed in thymocyte populations.The polymorphism and length of the T-cell receptor(TCR)P chain complementarity-determining region 3(CDR3)were analyzed using capillary electrophoresis DNA laser scanning analysis(ABI 3730).Results:Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET.Moreover,the proportions of DP cells(control:72.130±4.074,72-h:10.600±3.517,8-day:84.770±2.228),CD4+SP cells(control:15.770±4.419,72-h:44.670±3.089,8-day:6.367±0.513),and CD8+SP cells(control:7.000±1.916,72-h:34.030±3.850,8-day:5.133±0.647)were obviously different at different stages of ET.The polymorphism and length of TCR β chain CDR3 also changed obviously,indicating the occurrence of TCR rearrangement and thymocyte diversification.Further analysis showed that the expression of surface molecules,including CD44,CD69,and CD62L,on thymocyte populations(DP and SP cells)were changed to different degrees.Finally,the proliferation,apoptosis,cytokine production,and ERK pathway signaling of thymocyte populations were changed significantly.Conclusion:These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.
基金This work was supported by the National Key R&D Program of China(2020YFA0803601)the National Natural Science Foundation of China(32125022 and 32101046)the China Postdoctoral Science Foundation(2019M661348 and 2020T130115).
文摘Brown adipose tissue(BAT)plays a key role in thermogenesis during acute cold exposure.However,it remains unclear how BAT is prepared to rapidly turn on thermogenic genes.Here,we show that damage-specific DNA binding protein 1(DDB1)mediates the rapid transcription of thermogenic genes upon acute cold exposure.Adipose-or BAT-specific Ddb1 knockout mice show severely whitened BAT and significantly decreased expression of thermogenic genes.These mice develop hypothermia when subjected to acute cold exposure at 4℃ and partial lipodystrophy on a high-fat diet due to deficiency in fatty acid oxidation.Mechanistically,DDB1 binds the promoters of Ucp1 and Ppargc1a and recruits positive transcriptional elongation factor b(P-TEFb)to release promoter-proximally paused RNA polymerase II(Pol II),thereby enabling rapid and synchronized transcription of thermogenic genes upon acute cold exposure.Our findings have thus provided a regulatory mechanism of how BAT is prepared to respond to acute cold challenge.
