AIM: To investigate the roles of PKC-α/ezrin signals in phagocytosis crisis of retinal pigment epithelium(RPE) cells in light damage model. METHODS: Light induced mice RPE injury model was established by continuo...AIM: To investigate the roles of PKC-α/ezrin signals in phagocytosis crisis of retinal pigment epithelium(RPE) cells in light damage model. METHODS: Light induced mice RPE injury model was established by continuously irradiating cool white light at different exposure time(0, 4, 8h light intensity: 4.18×10^-6 J/cm^2). In vitro, human ARPE-19 cells treated with the doses and intensity(1.57×10^-6 J/cm^2) of laser irradiation. Histology analysis was evaluated by hematoxylin and eosin(HE) staining. In vivo RPE phagocytosis was quantified by measuring the accumulation of photoreceptor outer segments in the sub-retinal space. In vitro RPE phagocytosis was assessed by calculating the relative fluorescence intensity of FITC-labeled microspheres in ARPE-19 cells. To further investigate the molecular mechanism, the activation of PKC-α/ezrin signal was evaluated by Western blot in vivo and in vitro.RESULTS: HE staining revealed that the thickness of outer nuclear layer decreased significantly after 4 and 8h light exposure. By immunostaining with rhodopsin, a significant greater accumulation of photoreceptor outer segment was noticed after light injury. In vitro, light injuredRPE cells had less phagocytic activity in a dose dependent manner than that of the normal control(P〈0.01). Western blot suggested the activation of PKC-α/ezrin signaling was down-regulated in a dose-dependent manner after light exposure. CONCLUSION: Our data suggest that light induced phagocytic crisis of RPE cells may result from the downregulation of PKC-α/ezrin signaling.展开更多
AIM: To clone and characterize the porcine aquaporins (AQPs) in the gastrointestinal system.METHODS: A PCR-based cloning strategy and RACE were used to clone full-length AQP coding sequence from reversely transcri...AIM: To clone and characterize the porcine aquaporins (AQPs) in the gastrointestinal system.METHODS: A PCR-based cloning strategy and RACE were used to clone full-length AQP coding sequence from reversely transcribed pig liver cDNA. Stopped-flow light scattering and a YFP-based fluorescence method were used to measure the osmotic water permeability of erythrocytes and the stably transfected CHO cells. RT-PCR, Northern blot, and immunohistochemistry were used to determine the gastrointestinal expression and localization of cloned AQPs. Protein expression in transfected cells and red blood cells was analyzed by Western blot.RESULTS: An 813 bp cDNA encoding a 271 amino acid porcine aquaporin (designated pAQP1) was cloned from liver mRNA (pAQP1 has a 93% identity with human AQP1 and contains two NPA motifs conserved in AQP family, one consensus sequence for N-linked glycosylation, and one mercury-sensitive site at cysteine 191). RT-PCR analysis revealed extensive expression of pAQP1 mRNA in porcine digestive glands and gut. Northern blot showed a single 3.0 kb transcript in selected digestive organs, pAQP1 protein was localized at central lacteals of the small intestine, microvessles of salivary glands, as well as epithelium of intrahepatic bile ducts by immunoperoxydase. High osmotic water permeability that is inhibitable by HgCI2 was detected in porcine erythrocytes and CHO cells stably transfected with pAQP1 cDNA. Immunoblot analysis of porcine erythrocytes and pAQP-transfected CHO cells revealed an unglycosylated 28 ku band and larger glycosylated proteins.CONCLUSION: pAQP1 is the first porcine aquaporin that can be molecularly identified so far. The broad distribution of pAQP1 in epithelium and endothelium of porcine digestive organs may suggest an important role of channel-mediated water transport in fluid secretion/absorption as well as in digestive function and pathophysiology of the gastrointestinal system.展开更多
AIM:To investigate the content of serum micro RNA-126(mi R-126) and its role in screening retinal endothelial injury and early diagnosis of proliferative diabetic retinopathy.METHODS:The study included 184 serum s...AIM:To investigate the content of serum micro RNA-126(mi R-126) and its role in screening retinal endothelial injury and early diagnosis of proliferative diabetic retinopathy.METHODS:The study included 184 serum samples,59 samples from healthy individuals,44 samples from diabetes mellitus(DM) patients without diabetic retinopathy(NDR),42 from non-proliferative diabetic retinopathy(NPDR) patients and 39 samples from proliferative diabetic retinopathy(PDR) patients.The expression of mi R-126 was evaluated using a real-time quantitative polymerase chain reaction.RESULTS:The serum content of mi R-126 declined as the damage degree in the retina.There was significant difference between the two retinopathy groups(P〈0.001).No difference was observed in mi R-126 content between healthy individuals and NDR patients(P〉0.05).Receiver operating characteristic curve(ROC) analyses indicated that serum mi R-126 had significant diagnostic value for PDR.It yielded an area under the curve(AUC) of ROC of 0.976 with 81.21% sensitivity and 90.34% specificity in discriminating PDR from healthy controls,and an AUC of ROC of 0.919 with 84.75% sensitivity and 94.41% specificity in discriminating NDR and NPDR from healthy controls.When the diagnostic threshold was greater than or equal to 8.43,there was an increase in the possibility of NPDR.When the content of mi R-126 was less than or equal to 5.02,the possibility of the occurrence of PDR increased.CONCLUSION:Serum mi R-126 can serve as a non-invasive biomarker for screening retinal endothelial injury and early diagnosis PDR.展开更多
Double main phase process is applied to fabricate [(Pr, Nd)1 – xMMx]13.8FebalM1.5B5.9 (x = 0.5 and 0.7;M = Cu, Al, Co, and Nb) sintered magnets with high misch metal (MM) content. In comparison to the magnets by sing...Double main phase process is applied to fabricate [(Pr, Nd)1 – xMMx]13.8FebalM1.5B5.9 (x = 0.5 and 0.7;M = Cu, Al, Co, and Nb) sintered magnets with high misch metal (MM) content. In comparison to the magnets by single main phase process, the enhanced magnetic properties have been achieved. For magnets of x = 0.7, Hcj increases to 371.9 kA/m by 60.5%, and (BH)max is significantly enhanced to 253.3 kJ/m3 by 56.9%, compared with those of the single main phase magnets of the same nominal composition. In combination with minor loops and magnetic recoil curves, the property improvement of magnets with double main phase method is well explained. As a result, it is demonstrated that double main phase technology is an effective approach to improve the permanent magnetic properties of MM based sintered magnets.展开更多
Electroacupuncture has therapeutic effects on ischemic brain injury, but its mechanism is still poorly understood. In this study, mice were stimulated by electroacupuncture at the Baihui(GV20) acupoint for 30 minute...Electroacupuncture has therapeutic effects on ischemic brain injury, but its mechanism is still poorly understood. In this study, mice were stimulated by electroacupuncture at the Baihui(GV20) acupoint for 30 minutes at 1 m A and 2/15 Hz for 5 consecutive days. A cerebral ischemia model was established by ligating the bilateral common carotid artery for 15 minutes. At 72 hours after injury, neuronal injury in the mouse hippocampus had lessened, and the number of terminal deoxynucleotide transferase-mediated d UTP nick-end labeling-positive cells reduced after electroacupuncture treatment. Moreover, expression of adenosine monophosphate-activated protein kinase α(AMPKα) and phosphorylated AMPKα was up-regulated. Intraperitoneal injection of the AMPK antagonist, compound C, suppressed this phenomenon. Our findings suggest that electroacupuncture preconditioning alleviates ischemic brain injury via AMPK activation.展开更多
BACKGROUND Tooth avulsion is one of the most severe types of dental trauma.Most avulsed teeth undergo long-term ankylosis and replacement resorption after delayed reimplantation and exhibit a poor prognosis.The aim of...BACKGROUND Tooth avulsion is one of the most severe types of dental trauma.Most avulsed teeth undergo long-term ankylosis and replacement resorption after delayed reimplantation and exhibit a poor prognosis.The aim of this work was to improve the success rate of avulsed teeth after delayed reimplantation using autologous platelet-rich fibrin(PRF).CASE SUMMARY Case 1 was a 14-year-old boy who fell and knocked out his left upper central incisor 18 h prior to his arrival at the department.The diagnoses were avulsion of tooth 21,lateral luxation of tooth 11 and alveolar fracture of teeth 11 and 21.In case 2,a 17-year-old boy fell 2 h prior to his presentation to the hospital,and his left upper lateral incisor was completely knocked out of the alveolar socket.The diagnoses included avulsion of tooth 22,complicated crown fracture of tooth 11and complicated crown-root fracture of tooth 21.The avulsed teeth were reimplanted along with autologous PRF granules and splinted using a semiflexible titanium preshaped labial arch.The root canals of the avulsed teeth were filled with calcium hydroxide paste,and root canal filling was performed 4 wk after reimplantation.The reimplanted teeth showed no symptoms of inflammatory root resorption or ankylosis at the 3-,6-,and 12-mo follow-up examinations after reimplantation with autologous PRF.In addition to the avulsed teeth,the other injured teeth were treated using corresponding conventional treatment methods.CONCLUSION These cases provide examples of the successful use of PRF to reduce pathological root resorption of the avulsed teeth,and the application of PRF may provide new healing opportunities for traditionally“hopeless”avulsed teeth.展开更多
BACKGROUND Type 1 diabetes(T1D),a chronic metabolic and autoimmune disease,seriously endangers human health.In recent years,mesenchymal stem cell(MSC)transplantation has become an effective treatment for diabetes.Mens...BACKGROUND Type 1 diabetes(T1D),a chronic metabolic and autoimmune disease,seriously endangers human health.In recent years,mesenchymal stem cell(MSC)transplantation has become an effective treatment for diabetes.Menstrual bloodderived endometrial stem cells(MenSC),a novel MSC type derived from the decidual endometrium during menstruation,are expected to become promising seeding cells for diabetes treatment because of their noninvasive collection procedure,high proliferation rate and high immunomodulation capacity.AIM To comprehensively compare the effects of MenSC and umbilical cord-derived MSC(UcMSC)transplantation on T1D treatment,to further explore the potential mechanism of MSC-based therapies in T1D,and to provide support for the clinical application of MSC in diabetes treatment.METHODS A conventional streptozotocin-induced T1D mouse model was established,and the effects of MenSC and UcMSC transplantation on their blood glucose and serum insulin levels were detected.The morphological and functional changes in the pancreas,liver,kidney,and spleen were analyzed by routine histological and immunohistochemical examinations.Changes in the serum cytokine levels in the model mice were assessed by protein arrays.The expression of target proteins related to pancreatic regeneration and apoptosis was examined by western blot.RESULTS MenSC and UcMSC transplantation significantly improved the blood glucose and serum insulin levels in T1D model mice.Immunofluorescence analysis revealed that the numbers of insulin+and CD31+cells in the pancreas were significantly increased in MSC-treated mice compared with control mice.Subsequent western blot analysis also showed that vascular endothelial growth factor(VEGF),Bcl2,Bcl-xL and Proliferating cell nuclear antigen in pancreatic tissue was significantly upregulated in MSC-treated mice compared with control mice.Additionally,protein arrays indicated that MenSC and UcMSC transplantation significantly downregulated the serum levels of interferonγand tumor necrosis factorαand upregulated the serum levels of interleukin-6 and VEGF in the model mice.Additionally,histological and immunohistochemical analyses revealed that MSC transplantation systematically improved the morphologies and functions of the liver,kidney,and spleen in T1D model mice.CONCLUSION MenSC transplantation significantly improves the symptoms in T1D model mice and exerts protective effects on their main organs.Moreover,MSC-mediated angiogenesis,antiapoptotic effects and immunomodulation likely contribute to the above improvements.Thus,MenSC are expected to become promising seeding cells for clinical diabetes treatment due to their advantages mentioned above.展开更多
Objective To investigate the effect of emodin on lipopolysaccharides (LPS)-induced corneal injury in rats. Methods Three parallel incisions on the central surface of corneal epithelium were made and LPS was applied...Objective To investigate the effect of emodin on lipopolysaccharides (LPS)-induced corneal injury in rats. Methods Three parallel incisions on the central surface of corneal epithelium were made and LPS was applied on them to induce corneal injury in Wistar rats. All rats were randomly divided into emodin group (n=40) and keratitis group (n=40). Rats in the emodin group received subconjunctival injection of emodin and rats in the keratitis group received its vehicle 30 minutes before LPS exposure. At different time points-1 3, 6, 12, and 24 hours after LPS exposure, the symptoms of all rats were observed and the severity of their ocular inflammation was examined with a slit lamp microscope, then 8 rats in each group were killed through cervical dislocation and their eyes were enucleated and prepared to observe pathological changes of corneal tissue under a light microscope. The activation of nuclear factor-loB (NF-κB) under different condi- tions was determined by Western blot. Immunocytochemistry staining with an antibody against intercellular adhesion molecule-1 (ICAM-1) was performed to identify positive cells in corneal tissues. Results The model of acute keratitis was successfully established in Wistar rats. LPS could induce a typical corneal inflammatory response, such as hyperemia, corneal edema and opacity, which were observed in model rats. Compared with keratitis group, both ocular behaviors and damages of the corneal structure were improved in emodin group. Furthermore, the activation of NF-κB and the expression of ICAM-1 induced by LPS were markedly inhibited in emodin group. Conclusion Emodin can inhibit the activation of NF-κB and the expression of ICAM-I induced by LPS in corneas, protect against acute corneal injury, and improve symptoms in rats.展开更多
To suppress the electric field crowding at sidewall and improve the detection sensitivity of the AlGaN separate absorption and multiplication(SAM)avalanche photodiodes(APDs),we propose the new AlGaN APDs structure com...To suppress the electric field crowding at sidewall and improve the detection sensitivity of the AlGaN separate absorption and multiplication(SAM)avalanche photodiodes(APDs),we propose the new AlGaN APDs structure combining a large-area mesa with a field plate(FP).The simulated results show that the proposed AlGaN APDs exhibit a significant increase in avalanche gain,about two orders of magnitude,compared to their counterparts without FP structure,which is attributed to the suppression of electric field crowding at sidewall of multiplication layer and the reduction of the maximum electric field at the p-type GaN sidewall in p-n depletion region.Meanwhile,the APDs can produce an obviously enhanced photocurrent due to the increase in cross sectional area of multiplication region.展开更多
The misch-metal (MM) partially substituted Nd-Fe-B sintered magnets were fabricated by the dual alloy method, and the crystal structure, microstructure, and magnetic properties were analyzed comprehensively. X-ray d...The misch-metal (MM) partially substituted Nd-Fe-B sintered magnets were fabricated by the dual alloy method, and the crystal structure, microstructure, and magnetic properties were analyzed comprehensively. X-ray diffraction (XRD) reveals that the increasing content of the MM has an inconsiderable effect on the crystallographic alignment of the magnets. Grains of the two main phases are uniformly distributed, and slightly deteriorate on the grain boundary. Due to the diffusion between the adjacent grains, the MM substituted Nd-Fe-B magnets contain three types of components with different Ce/La concentrations. Moreover, the first-order reversal curve (FORC) diagram is introduced to analyze the magnetization reversal process, coercivity mechanism, and distribution of reversal field in magnetic samples. The analysis indicates that there are two major reversal components, corresponding to the two different main phases. The domain nucleation and growth are determined to be the leading mechanism in controlling the magnetization reversal processes of the magnets sintered by the dual alloy method.展开更多
Objective This study was to examine the relationship between socioeconomic status and the incidence and mortality of non-Hodgkin lymphoma(NHL).Methods We compared the age-standardized incidence rate(ASIR),age-standard...Objective This study was to examine the relationship between socioeconomic status and the incidence and mortality of non-Hodgkin lymphoma(NHL).Methods We compared the age-standardized incidence rate(ASIR),age-standardized mortality rate(ASMR),and the ASMR to ASIR ratio(MIR)at national and regional levels and studied the correlation between the MIR and the human development index(HDI)in 2012 and 2018.Results The highest ASIR was in North America in 2012 and in Australia in 2018,and the lowest ASIR was in Central and South Asia in both 2012 and 2018.The highest ASMR was in North Africa in both 2012 and 2018,and the lowest ASMR was in Eastern Asia and South-Central Asia in 2012 and in South-Central Asia in 2018.The lowest MIR was in Australia in both 2012 and 2018,and the highest MIR was in Western Africa in both 2012 and 2018.HDI was strongly negatively correlated with MIR(r:−0.8810,P<0.0001,2012;r:−0.8895,P<0.0001,2018).Compared to the 2012 data,the MIR in the intermediate HDI countries significantly deceased and the HDI in low and high HDI countries significantly increased in 2018.Conclusion The MIR is negatively correlated with HDI.Increasing the HDI in low and intermediate HDI countries may reduce the MIR and increase the survival of patients with NHL.展开更多
Objective: To explore the effect of felodipine in combined with irbesartan on the blood uric acid (UA);serum adiponectin (APN);and renal function in young males with essential hypertension (EH). Methods: A total of 13...Objective: To explore the effect of felodipine in combined with irbesartan on the blood uric acid (UA);serum adiponectin (APN);and renal function in young males with essential hypertension (EH). Methods: A total of 134 young male patients with EH who were admitted in our hospital from January;2016 to January;2017 were included in the study and randomized into the observation group and the control group. The patients in the control group were given felodipine sustanined release tablets;5 mg/time;1 time/d. On this basis;the patients in the observation group were given irbesartan;150 mg/time;1 time/d. To those whose blood pressure was not reduced under 140/90 mmHg after 4 week treatment;the dose of felodipine sustanined release tablets was increased to 10 mg/d. A maintenance dose was adopted according to the individual conditions until the ideal blood pressure reduction effect was achieved. The morning fasting venous blood was collected before treatment;4 and 12 weeks after treatment in the two groups. ELISA was used to detect APN level. Uricase-peroxide enzymic method was used to detect UA level. The full automatic biochemical analyzer was used to detect BUN and Scr. Ccr was calculated. Urine was collected. RIA was used to detect 24 h Upro. The morning fasting venous blood before treatment;24 and 48 weeks after treatment was collected. RIA was used to detect the serum T and SHBG levels. Results: Scr and 24 h Upro 4 and 12 weeks after treatment in the two groups were gradually reduced;while Ccr was gradually elevated. BUN 12 weeks after treatment in the observation group was significantly reduced. Scr and 24 h Upro 4 and 12 weeks after treatment in the observation group were significantly lower than those in the control group;while Ccr was significantly higher than that in the control group. BUNS 12 weeks after treatment in the observation group were significantly lower than those in the control group. T level 24 and 48 weeks after treatment in the two groups was significantly elevated;while SHBG after treatment was not significantly changed. T level 24 and 48 weeks after treatment in the observation group was significantly higher than that in the control group. APN 4 and 12 weeks after treatment in the two groups was significantly elevated;while UA was significantly reduced. APN 4 and 12 weeks after treatment in the observation group was significantly higher than that in the control group;while UA was significantly lower than that in the control group. Conclusions: Felodipine in combined with irbesartan in the treatment of EH in young males can effectively regulate APN and UA levels;protect the renal function;enhance the sex hormone levels;and has a great significance in reducing the target organ damage and improving the prognosis.展开更多
In this study, the effect of wheel speed and mischmetal(MM) content on the magnetic properties of MMFeB ribbons was investigated. The samples were prepared via direct solidification technique. The nominal compositio...In this study, the effect of wheel speed and mischmetal(MM) content on the magnetic properties of MMFeB ribbons was investigated. The samples were prepared via direct solidification technique. The nominal composition of the alloy ingots is MM;Fe;B;with x varying from 9 to 15 in steps of 2. Experimental results show the overall magnetic properties of the ribbons.Analysis of the results shows that the magnetic properties first improve and then degrade with the wheel speed and MM content increasing. Increase in MM content leads to better formation of crystal texture in the ribbons, indicating that the a-Fe phase might undermine the formation of crystal texture. Magnetic properties results show that the coercivity of the ribbons rises with an appropriate increase in both MM content and wheel speed during melt-spun process. The strongest magnetic properties of the ribbons(remanence of M;= 0.72 T, intrinsic coercivity of H;= 352.58 kA·m;, and maximum energy product of(BH);=72.14 kJ·m;) are obtained for compositions where x = 13 and a wheel speed of v = 20 m·s;.展开更多
The isotropic nanocrystalline[(PrNd)0.8MM0.2]29.8Fe68.7Al0.1Cu0.12Co0.88B magnets(MM:mischmetal)were prepared by single-main phase and double-main phase methods using spark plasma sintering(SPS).Melt-spinning method w...The isotropic nanocrystalline[(PrNd)0.8MM0.2]29.8Fe68.7Al0.1Cu0.12Co0.88B magnets(MM:mischmetal)were prepared by single-main phase and double-main phase methods using spark plasma sintering(SPS).Melt-spinning method was used to prepare initial powder and avoid component deviations caused by longtime ball milling.The magnetic properties of the magnet prepared by double-main phase method(called double-main phase magnet,DMP magnet)are remanence of Br=0.75 T,intrinsic coercivity of Hcj=909.83 kA·m-1,maximum magnetic energy product of(BH)max=95.48 kJ·m-3,which are better than those of the magnet prepared by single-main phase method(called singlemain phase magnet,SMP magnet).The diffraction peaks of the main phase of DMP magnet split in X-ray diffractometer(XRD)pattern,indicating that R2 Fe14B phases with different distributions of La/Ce elements exist in the magnet.This speculation is confirmed by transmission electron microscopy(TEM)observation.The La/Ce-rich main phase and La/Celean main phase are present in DMP magnets.The heterogeneity of rare earth elements suppresses the magnetic dilution effect in DMP magnet,and the magnetic properties are improved.Though the DMP magnet contains different main phases,it presents unitary Curie temperature(TC)of 577 K,which is higher than that of SMP magnet.This result suggests that the TC of the magnets can be promoted by double-main phase method and SPS.展开更多
Objective:Hederacolchiside A1,exhibits cytostatic and cytotoxic activity against various cancer cells in vitro,however,the mechanism is not well understood.Methods:In this study,hederacolchiside A1 from Pulsatilla c...Objective:Hederacolchiside A1,exhibits cytostatic and cytotoxic activity against various cancer cells in vitro,however,the mechanism is not well understood.Methods:In this study,hederacolchiside A1 from Pulsatilla chinensis was isolated and tested its anticancer activity and mechanism.Hederacolchiside A1 could inhibit proliferation of A549,SMMC-7721,BEL-7402,and MCF-7 cells by MTT assay.Investigations of apoptosis of treated cancer cells were identified in hederacolchiside A1 by flow cytometric analysis of annexin V expression.Results:Based on the results of western blotting and JC-1 staining,hederacolchiside A1 reduced the mitochondrial membrane potential and Bcl-2 protein levels,whereas cleaved caspase-3 was higher.Furthermore,hederacolchiside A1 effectively inhibited the phosphorylations of phosphatidylinositol 3 kinase(PI3K),protein kinase B(Akt),and mammalian target of rapamycin(m TOR).In vivo study showed that hederacolchiside A1(3.0,4.5,and 6.0 mg/kg,ip)could significantly inhibit the weight of tumor in anmodel.Similar inhibitory activities were observed when the compound(3.25,7.5,and15.0 mg/kg,ig)was tested in nude mice xenograft tumor models using human breast carcinoma MCF-7 cells.Conclusion:These data indicated that hederacolchiside A1 suppressed the proliferation of human tumor cells by inducing apoptosis through modulating the PI3K/Akt/m TOR signaling pathway.展开更多
The magnetic properties and microstructure of sintered R-Fe-B(R, rare earth) magnets with nominal composition of((PrNd)(1-x)MMx)(30)Fe(bal)B1(x = 0, 0.1.0.2,0.3, 0.4, 0.5 and 0.7; MM, misch metal) prepar...The magnetic properties and microstructure of sintered R-Fe-B(R, rare earth) magnets with nominal composition of((PrNd)(1-x)MMx)(30)Fe(bal)B1(x = 0, 0.1.0.2,0.3, 0.4, 0.5 and 0.7; MM, misch metal) prepared using dual-alloy method were investigated. For x = 0.3, the maximum energy product((BH)(max)) of the sintered magnet is higher than 318.4 kJ·m^-3,but intrinsic coercivity(H(cj)) is lower than 351.8 kA·m^-1. The La and Ce contents are obviously different in some matrix-phase grains, which proves that the multi-hard magnetic phases(La, Ce-rich and La, Ce-lean) exist in the magnets. The coercivity is improved by the method of doping PrNd nanoparticles without sacrificing other magnetic properties. An enhancement in coercivity from 517.2 to 872.9 kA·m^-1 is achieved by doping 5 wt% PrNd nanoparticles. Meanwhile, it could exhibit better magnetic properties(remanence Br = 1.332 T.intrinsic coercivity H(cj)= 872.9 kA·m^-1 maximum energy product(BH)(max)=318.6 kJ·m^-3) and make the distribution of the intergranular phase become more homogeneous.展开更多
This study investigated the oxidation behavior of a new casting Ni-based superalloy K4750 at 750°C-1000°C in air for 100 h-1000 h by isothermal oxidation tests.The oxidation-kinetic curves were plotted by th...This study investigated the oxidation behavior of a new casting Ni-based superalloy K4750 at 750°C-1000°C in air for 100 h-1000 h by isothermal oxidation tests.The oxidation-kinetic curves were plotted by the static discontinuous weight gain method.Observation and identification of oxidation products were conducted using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),electron probe micro-analysis(EPMA)and X-ray diffraction(XRD).X-ray photoelectron spectrometer(XPS)was also used to analyze the chemical state of elements and the distribution in depth.The results showed that the oxidation-kinetic curves of K4750 alloy basically obeyed the parabolic law.The average oxidation rate below 900°C was less than 0.1 g/m 2·h which meant the alloy was at a complete anti-oxidation grade,and the alloy was at an anti-oxidation grade at 1000°C.The predominant surface oxide was Cr_(2)O_(3),and a double layer structure of the oxide scale was observed at all tested temperatures as time increased.The outer oxide layer contained continuous Cr_(2)O_(3)and a small amount of oxides mixed TiO2 and NiCr2O4,while the inner oxide layer was composed with Al_(2)O_(3).The oxidation process could be interpreted by the competitive oxidation of different elements.The diffusion rate of Ti through Cr_(2)O_(3)layer increased with increasing temperature,and thus the generation of TiO2 was advantageous.The dispersed TiO2 reaching a certain amount destroyed the continuity of the surface oxide layer,which accounted for the reduction of oxidation resistance of K4750 alloy at high temperatures.展开更多
To the Editor:Blue rubber bleb nevus syndrome (BRBNS) is a rare systemic vascular disorder characterized by multiple venous malformations involving many organs.BRBNS can occur in various organs,but the most frequently...To the Editor:Blue rubber bleb nevus syndrome (BRBNS) is a rare systemic vascular disorder characterized by multiple venous malformations involving many organs.BRBNS can occur in various organs,but the most frequently involved organs are the skin and gastrointestinal tract.Gastrointestinal lesions of BRBNS can cause acute or chronic bleeding and anemia.[1] Only several case reports of pregnant women with BRBNS could be found in the current database and most of them were complicated by hemorrhage of the gastrointestinal tract.We report a case of BRBNS during pregnancy that suffered from severe pulmonary embolism (PE) and was successfully resuscitated.展开更多
Objective To investigate the chemical constituents from Aidi Injection.Methods The chemical constituents were isolated by chromatography on Sephadex LH-20 gel columns and reverse phase semi-preparative HPLC repeatedly...Objective To investigate the chemical constituents from Aidi Injection.Methods The chemical constituents were isolated by chromatography on Sephadex LH-20 gel columns and reverse phase semi-preparative HPLC repeatedly.Their structures were identified by spectroscopic analysis(NMR and MS).Results Twenty-two compounds were isolated and identified to be 3-O-3′,4′-diacetyl-β-D-xylopyranosyl-6-O-β-D-glucopyranosyl- cycloastragenol(1),astragaloside IV(2),astragaloside II(3),astragaloside I(4),isoastragaloside I(5), acetylastragaloside I(6),ginsenosid Re(7),ginsenoside Rf(8),ginsenoside Rg1(9),ginsenoside Rb3(10), notoginsenoside R4(11),ginsenoside Rb1(12),ginsenoside Rc(13),ginsenoside Rb2(14),ginsenoside Rd(15), lucyoside H(16),3-O-β-D-glucopyranosyl(1→4)-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)-α-L- arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl(1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside (17),3-O-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl[β-D-glucopyranosyl-(1→4)]-(1→2)-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-arabinopyranosyl(1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside(18),syringin (19),elentheroside E(20),4-(1,2,3-trihydroxypropyl)-2,6-dimethoxyphenyl-1-O-β-D-glucopyranoside(21),and coniferin(22).Conclusion Compounds 1-6 are originated from Astragalus membranceus,compounds 7-18 are originated from Panax ginseng,and compounds 19-22 are originated from Acanthopanax senticosus by LC-MS analysis.Compound 1 is a new compound.展开更多
基金Supported by the National Natural Science Foundation of China(No.81641057)the Natural Science Foundation of Liaoning Province(No.201602292No.201602298)
文摘AIM: To investigate the roles of PKC-α/ezrin signals in phagocytosis crisis of retinal pigment epithelium(RPE) cells in light damage model. METHODS: Light induced mice RPE injury model was established by continuously irradiating cool white light at different exposure time(0, 4, 8h light intensity: 4.18×10^-6 J/cm^2). In vitro, human ARPE-19 cells treated with the doses and intensity(1.57×10^-6 J/cm^2) of laser irradiation. Histology analysis was evaluated by hematoxylin and eosin(HE) staining. In vivo RPE phagocytosis was quantified by measuring the accumulation of photoreceptor outer segments in the sub-retinal space. In vitro RPE phagocytosis was assessed by calculating the relative fluorescence intensity of FITC-labeled microspheres in ARPE-19 cells. To further investigate the molecular mechanism, the activation of PKC-α/ezrin signal was evaluated by Western blot in vivo and in vitro.RESULTS: HE staining revealed that the thickness of outer nuclear layer decreased significantly after 4 and 8h light exposure. By immunostaining with rhodopsin, a significant greater accumulation of photoreceptor outer segment was noticed after light injury. In vitro, light injuredRPE cells had less phagocytic activity in a dose dependent manner than that of the normal control(P〈0.01). Western blot suggested the activation of PKC-α/ezrin signaling was down-regulated in a dose-dependent manner after light exposure. CONCLUSION: Our data suggest that light induced phagocytic crisis of RPE cells may result from the downregulation of PKC-α/ezrin signaling.
基金Supported by National Natural Science Foundation for Distinguished Young Scholars,No.30325011National Natural Science Foundation of China,No.30470405Distinguished Young Scholar Foundation of Jilin Province,No.20030112.
文摘AIM: To clone and characterize the porcine aquaporins (AQPs) in the gastrointestinal system.METHODS: A PCR-based cloning strategy and RACE were used to clone full-length AQP coding sequence from reversely transcribed pig liver cDNA. Stopped-flow light scattering and a YFP-based fluorescence method were used to measure the osmotic water permeability of erythrocytes and the stably transfected CHO cells. RT-PCR, Northern blot, and immunohistochemistry were used to determine the gastrointestinal expression and localization of cloned AQPs. Protein expression in transfected cells and red blood cells was analyzed by Western blot.RESULTS: An 813 bp cDNA encoding a 271 amino acid porcine aquaporin (designated pAQP1) was cloned from liver mRNA (pAQP1 has a 93% identity with human AQP1 and contains two NPA motifs conserved in AQP family, one consensus sequence for N-linked glycosylation, and one mercury-sensitive site at cysteine 191). RT-PCR analysis revealed extensive expression of pAQP1 mRNA in porcine digestive glands and gut. Northern blot showed a single 3.0 kb transcript in selected digestive organs, pAQP1 protein was localized at central lacteals of the small intestine, microvessles of salivary glands, as well as epithelium of intrahepatic bile ducts by immunoperoxydase. High osmotic water permeability that is inhibitable by HgCI2 was detected in porcine erythrocytes and CHO cells stably transfected with pAQP1 cDNA. Immunoblot analysis of porcine erythrocytes and pAQP-transfected CHO cells revealed an unglycosylated 28 ku band and larger glycosylated proteins.CONCLUSION: pAQP1 is the first porcine aquaporin that can be molecularly identified so far. The broad distribution of pAQP1 in epithelium and endothelium of porcine digestive organs may suggest an important role of channel-mediated water transport in fluid secretion/absorption as well as in digestive function and pathophysiology of the gastrointestinal system.
基金Supported by Science and Technology Planning Project of Guangdong Province(No.201 4A020212631)Science and Technology Planning Project of Guangzhou(No.201604020105)Science and Technology Planning Project of Tianhe District,Guangzhou(No.201504KW023)
文摘AIM:To investigate the content of serum micro RNA-126(mi R-126) and its role in screening retinal endothelial injury and early diagnosis of proliferative diabetic retinopathy.METHODS:The study included 184 serum samples,59 samples from healthy individuals,44 samples from diabetes mellitus(DM) patients without diabetic retinopathy(NDR),42 from non-proliferative diabetic retinopathy(NPDR) patients and 39 samples from proliferative diabetic retinopathy(PDR) patients.The expression of mi R-126 was evaluated using a real-time quantitative polymerase chain reaction.RESULTS:The serum content of mi R-126 declined as the damage degree in the retina.There was significant difference between the two retinopathy groups(P〈0.001).No difference was observed in mi R-126 content between healthy individuals and NDR patients(P〉0.05).Receiver operating characteristic curve(ROC) analyses indicated that serum mi R-126 had significant diagnostic value for PDR.It yielded an area under the curve(AUC) of ROC of 0.976 with 81.21% sensitivity and 90.34% specificity in discriminating PDR from healthy controls,and an AUC of ROC of 0.919 with 84.75% sensitivity and 94.41% specificity in discriminating NDR and NPDR from healthy controls.When the diagnostic threshold was greater than or equal to 8.43,there was an increase in the possibility of NPDR.When the content of mi R-126 was less than or equal to 5.02,the possibility of the occurrence of PDR increased.CONCLUSION:Serum mi R-126 can serve as a non-invasive biomarker for screening retinal endothelial injury and early diagnosis PDR.
基金Project supported by the National Natural Foundation of China(Grant Nos.51590880,11564030,and 51571126)the National Key Research Program of China(Grant No.2016YFB0700903)+3 种基金Fujian Institute of Innovation,Chinese Academy of Sciences(Grant No.FJCXY18040302)the Key Program of the Chinese Academy of Sciences(Grant No.KJZD-EW-M05-1)the Inner Mongolia Science and Technology Major Project of 2016,Chinathe Natural Science Foundation of Inner Mongolia,China(Grant Nos.2018LH05006 and 2018LH05011)。
文摘Double main phase process is applied to fabricate [(Pr, Nd)1 – xMMx]13.8FebalM1.5B5.9 (x = 0.5 and 0.7;M = Cu, Al, Co, and Nb) sintered magnets with high misch metal (MM) content. In comparison to the magnets by single main phase process, the enhanced magnetic properties have been achieved. For magnets of x = 0.7, Hcj increases to 371.9 kA/m by 60.5%, and (BH)max is significantly enhanced to 253.3 kJ/m3 by 56.9%, compared with those of the single main phase magnets of the same nominal composition. In combination with minor loops and magnetic recoil curves, the property improvement of magnets with double main phase method is well explained. As a result, it is demonstrated that double main phase technology is an effective approach to improve the permanent magnetic properties of MM based sintered magnets.
基金supported by the National Natural Science Foundation of China,No.81273821
文摘Electroacupuncture has therapeutic effects on ischemic brain injury, but its mechanism is still poorly understood. In this study, mice were stimulated by electroacupuncture at the Baihui(GV20) acupoint for 30 minutes at 1 m A and 2/15 Hz for 5 consecutive days. A cerebral ischemia model was established by ligating the bilateral common carotid artery for 15 minutes. At 72 hours after injury, neuronal injury in the mouse hippocampus had lessened, and the number of terminal deoxynucleotide transferase-mediated d UTP nick-end labeling-positive cells reduced after electroacupuncture treatment. Moreover, expression of adenosine monophosphate-activated protein kinase α(AMPKα) and phosphorylated AMPKα was up-regulated. Intraperitoneal injection of the AMPK antagonist, compound C, suppressed this phenomenon. Our findings suggest that electroacupuncture preconditioning alleviates ischemic brain injury via AMPK activation.
基金Supported by Natural Science Foundation of China,No.31971248National Clinical Research Center for Oral Diseases Project of Military Stomatology,No.LCA202007。
文摘BACKGROUND Tooth avulsion is one of the most severe types of dental trauma.Most avulsed teeth undergo long-term ankylosis and replacement resorption after delayed reimplantation and exhibit a poor prognosis.The aim of this work was to improve the success rate of avulsed teeth after delayed reimplantation using autologous platelet-rich fibrin(PRF).CASE SUMMARY Case 1 was a 14-year-old boy who fell and knocked out his left upper central incisor 18 h prior to his arrival at the department.The diagnoses were avulsion of tooth 21,lateral luxation of tooth 11 and alveolar fracture of teeth 11 and 21.In case 2,a 17-year-old boy fell 2 h prior to his presentation to the hospital,and his left upper lateral incisor was completely knocked out of the alveolar socket.The diagnoses included avulsion of tooth 22,complicated crown fracture of tooth 11and complicated crown-root fracture of tooth 21.The avulsed teeth were reimplanted along with autologous PRF granules and splinted using a semiflexible titanium preshaped labial arch.The root canals of the avulsed teeth were filled with calcium hydroxide paste,and root canal filling was performed 4 wk after reimplantation.The reimplanted teeth showed no symptoms of inflammatory root resorption or ankylosis at the 3-,6-,and 12-mo follow-up examinations after reimplantation with autologous PRF.In addition to the avulsed teeth,the other injured teeth were treated using corresponding conventional treatment methods.CONCLUSION These cases provide examples of the successful use of PRF to reduce pathological root resorption of the avulsed teeth,and the application of PRF may provide new healing opportunities for traditionally“hopeless”avulsed teeth.
基金Henan Province Foundation of China,No.202300410307 and No.212102310611Xinxiang City Foundation of China,No.GG2020009.
文摘BACKGROUND Type 1 diabetes(T1D),a chronic metabolic and autoimmune disease,seriously endangers human health.In recent years,mesenchymal stem cell(MSC)transplantation has become an effective treatment for diabetes.Menstrual bloodderived endometrial stem cells(MenSC),a novel MSC type derived from the decidual endometrium during menstruation,are expected to become promising seeding cells for diabetes treatment because of their noninvasive collection procedure,high proliferation rate and high immunomodulation capacity.AIM To comprehensively compare the effects of MenSC and umbilical cord-derived MSC(UcMSC)transplantation on T1D treatment,to further explore the potential mechanism of MSC-based therapies in T1D,and to provide support for the clinical application of MSC in diabetes treatment.METHODS A conventional streptozotocin-induced T1D mouse model was established,and the effects of MenSC and UcMSC transplantation on their blood glucose and serum insulin levels were detected.The morphological and functional changes in the pancreas,liver,kidney,and spleen were analyzed by routine histological and immunohistochemical examinations.Changes in the serum cytokine levels in the model mice were assessed by protein arrays.The expression of target proteins related to pancreatic regeneration and apoptosis was examined by western blot.RESULTS MenSC and UcMSC transplantation significantly improved the blood glucose and serum insulin levels in T1D model mice.Immunofluorescence analysis revealed that the numbers of insulin+and CD31+cells in the pancreas were significantly increased in MSC-treated mice compared with control mice.Subsequent western blot analysis also showed that vascular endothelial growth factor(VEGF),Bcl2,Bcl-xL and Proliferating cell nuclear antigen in pancreatic tissue was significantly upregulated in MSC-treated mice compared with control mice.Additionally,protein arrays indicated that MenSC and UcMSC transplantation significantly downregulated the serum levels of interferonγand tumor necrosis factorαand upregulated the serum levels of interleukin-6 and VEGF in the model mice.Additionally,histological and immunohistochemical analyses revealed that MSC transplantation systematically improved the morphologies and functions of the liver,kidney,and spleen in T1D model mice.CONCLUSION MenSC transplantation significantly improves the symptoms in T1D model mice and exerts protective effects on their main organs.Moreover,MSC-mediated angiogenesis,antiapoptotic effects and immunomodulation likely contribute to the above improvements.Thus,MenSC are expected to become promising seeding cells for clinical diabetes treatment due to their advantages mentioned above.
基金Supported by Technology Foundation of Shandong Education Department (J08LH59)
文摘Objective To investigate the effect of emodin on lipopolysaccharides (LPS)-induced corneal injury in rats. Methods Three parallel incisions on the central surface of corneal epithelium were made and LPS was applied on them to induce corneal injury in Wistar rats. All rats were randomly divided into emodin group (n=40) and keratitis group (n=40). Rats in the emodin group received subconjunctival injection of emodin and rats in the keratitis group received its vehicle 30 minutes before LPS exposure. At different time points-1 3, 6, 12, and 24 hours after LPS exposure, the symptoms of all rats were observed and the severity of their ocular inflammation was examined with a slit lamp microscope, then 8 rats in each group were killed through cervical dislocation and their eyes were enucleated and prepared to observe pathological changes of corneal tissue under a light microscope. The activation of nuclear factor-loB (NF-κB) under different condi- tions was determined by Western blot. Immunocytochemistry staining with an antibody against intercellular adhesion molecule-1 (ICAM-1) was performed to identify positive cells in corneal tissues. Results The model of acute keratitis was successfully established in Wistar rats. LPS could induce a typical corneal inflammatory response, such as hyperemia, corneal edema and opacity, which were observed in model rats. Compared with keratitis group, both ocular behaviors and damages of the corneal structure were improved in emodin group. Furthermore, the activation of NF-κB and the expression of ICAM-1 induced by LPS were markedly inhibited in emodin group. Conclusion Emodin can inhibit the activation of NF-κB and the expression of ICAM-I induced by LPS in corneas, protect against acute corneal injury, and improve symptoms in rats.
基金the Natural Science Research Project of Anhui University,China(Grant No.KJ2019A0644)the National Natural Science Foundation of China(Grant Nos.61634002 and 61804089)+3 种基金the Natural Science Alliance Foundation,China(Grant No.U1830109)the Natural Science Foundation of Anhui Province,China(Grant No.1708085MF149)the Chuzhou University Research Project,China(Grant No.zrjz2019002)the Project of the Higher Educational and Technology Program of Shandong Province,China(Grant No.J16LN04).
文摘To suppress the electric field crowding at sidewall and improve the detection sensitivity of the AlGaN separate absorption and multiplication(SAM)avalanche photodiodes(APDs),we propose the new AlGaN APDs structure combining a large-area mesa with a field plate(FP).The simulated results show that the proposed AlGaN APDs exhibit a significant increase in avalanche gain,about two orders of magnitude,compared to their counterparts without FP structure,which is attributed to the suppression of electric field crowding at sidewall of multiplication layer and the reduction of the maximum electric field at the p-type GaN sidewall in p-n depletion region.Meanwhile,the APDs can produce an obviously enhanced photocurrent due to the increase in cross sectional area of multiplication region.
基金Project supported by the National Natural Science Foundation of China(Grant No.51590880)the National Key Research and Development Program of China(Grant Nos.2014CB643702 and 2016YFB0700903)+1 种基金Key Research Program of the Chinese Academy of Sciences of Chinathe Inner Mongolia Science and Technology Major Project of China 2016
文摘The misch-metal (MM) partially substituted Nd-Fe-B sintered magnets were fabricated by the dual alloy method, and the crystal structure, microstructure, and magnetic properties were analyzed comprehensively. X-ray diffraction (XRD) reveals that the increasing content of the MM has an inconsiderable effect on the crystallographic alignment of the magnets. Grains of the two main phases are uniformly distributed, and slightly deteriorate on the grain boundary. Due to the diffusion between the adjacent grains, the MM substituted Nd-Fe-B magnets contain three types of components with different Ce/La concentrations. Moreover, the first-order reversal curve (FORC) diagram is introduced to analyze the magnetization reversal process, coercivity mechanism, and distribution of reversal field in magnetic samples. The analysis indicates that there are two major reversal components, corresponding to the two different main phases. The domain nucleation and growth are determined to be the leading mechanism in controlling the magnetization reversal processes of the magnets sintered by the dual alloy method.
基金supported by the National Natural Science Foundation of China(No.81700147).
文摘Objective This study was to examine the relationship between socioeconomic status and the incidence and mortality of non-Hodgkin lymphoma(NHL).Methods We compared the age-standardized incidence rate(ASIR),age-standardized mortality rate(ASMR),and the ASMR to ASIR ratio(MIR)at national and regional levels and studied the correlation between the MIR and the human development index(HDI)in 2012 and 2018.Results The highest ASIR was in North America in 2012 and in Australia in 2018,and the lowest ASIR was in Central and South Asia in both 2012 and 2018.The highest ASMR was in North Africa in both 2012 and 2018,and the lowest ASMR was in Eastern Asia and South-Central Asia in 2012 and in South-Central Asia in 2018.The lowest MIR was in Australia in both 2012 and 2018,and the highest MIR was in Western Africa in both 2012 and 2018.HDI was strongly negatively correlated with MIR(r:−0.8810,P<0.0001,2012;r:−0.8895,P<0.0001,2018).Compared to the 2012 data,the MIR in the intermediate HDI countries significantly deceased and the HDI in low and high HDI countries significantly increased in 2018.Conclusion The MIR is negatively correlated with HDI.Increasing the HDI in low and intermediate HDI countries may reduce the MIR and increase the survival of patients with NHL.
文摘Objective: To explore the effect of felodipine in combined with irbesartan on the blood uric acid (UA);serum adiponectin (APN);and renal function in young males with essential hypertension (EH). Methods: A total of 134 young male patients with EH who were admitted in our hospital from January;2016 to January;2017 were included in the study and randomized into the observation group and the control group. The patients in the control group were given felodipine sustanined release tablets;5 mg/time;1 time/d. On this basis;the patients in the observation group were given irbesartan;150 mg/time;1 time/d. To those whose blood pressure was not reduced under 140/90 mmHg after 4 week treatment;the dose of felodipine sustanined release tablets was increased to 10 mg/d. A maintenance dose was adopted according to the individual conditions until the ideal blood pressure reduction effect was achieved. The morning fasting venous blood was collected before treatment;4 and 12 weeks after treatment in the two groups. ELISA was used to detect APN level. Uricase-peroxide enzymic method was used to detect UA level. The full automatic biochemical analyzer was used to detect BUN and Scr. Ccr was calculated. Urine was collected. RIA was used to detect 24 h Upro. The morning fasting venous blood before treatment;24 and 48 weeks after treatment was collected. RIA was used to detect the serum T and SHBG levels. Results: Scr and 24 h Upro 4 and 12 weeks after treatment in the two groups were gradually reduced;while Ccr was gradually elevated. BUN 12 weeks after treatment in the observation group was significantly reduced. Scr and 24 h Upro 4 and 12 weeks after treatment in the observation group were significantly lower than those in the control group;while Ccr was significantly higher than that in the control group. BUNS 12 weeks after treatment in the observation group were significantly lower than those in the control group. T level 24 and 48 weeks after treatment in the two groups was significantly elevated;while SHBG after treatment was not significantly changed. T level 24 and 48 weeks after treatment in the observation group was significantly higher than that in the control group. APN 4 and 12 weeks after treatment in the two groups was significantly elevated;while UA was significantly reduced. APN 4 and 12 weeks after treatment in the observation group was significantly higher than that in the control group;while UA was significantly lower than that in the control group. Conclusions: Felodipine in combined with irbesartan in the treatment of EH in young males can effectively regulate APN and UA levels;protect the renal function;enhance the sex hormone levels;and has a great significance in reducing the target organ damage and improving the prognosis.
基金financially supported by the National Natural Science Foundation of China (Nos. 51461033, 51571126, 51541105, and 11547032)the Inner Mongolia Innovative Research Team (No. 3400102)+3 种基金the Inner Mongolia Science Foundation (No. 2013MS0110)the Provincial Major Science and Technology Project of Inner Mongolia (No. 2009J1006)the Baotou Major Research Project Special for Rare Earth (No. 2012R1006)the Inner Mongolia University of Science and Technology Innovation Fund
文摘In this study, the effect of wheel speed and mischmetal(MM) content on the magnetic properties of MMFeB ribbons was investigated. The samples were prepared via direct solidification technique. The nominal composition of the alloy ingots is MM;Fe;B;with x varying from 9 to 15 in steps of 2. Experimental results show the overall magnetic properties of the ribbons.Analysis of the results shows that the magnetic properties first improve and then degrade with the wheel speed and MM content increasing. Increase in MM content leads to better formation of crystal texture in the ribbons, indicating that the a-Fe phase might undermine the formation of crystal texture. Magnetic properties results show that the coercivity of the ribbons rises with an appropriate increase in both MM content and wheel speed during melt-spun process. The strongest magnetic properties of the ribbons(remanence of M;= 0.72 T, intrinsic coercivity of H;= 352.58 kA·m;, and maximum energy product of(BH);=72.14 kJ·m;) are obtained for compositions where x = 13 and a wheel speed of v = 20 m·s;.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0700903)the National Natural Science Foundation of China(Nos.51571064 and 51571126).
文摘The isotropic nanocrystalline[(PrNd)0.8MM0.2]29.8Fe68.7Al0.1Cu0.12Co0.88B magnets(MM:mischmetal)were prepared by single-main phase and double-main phase methods using spark plasma sintering(SPS).Melt-spinning method was used to prepare initial powder and avoid component deviations caused by longtime ball milling.The magnetic properties of the magnet prepared by double-main phase method(called double-main phase magnet,DMP magnet)are remanence of Br=0.75 T,intrinsic coercivity of Hcj=909.83 kA·m-1,maximum magnetic energy product of(BH)max=95.48 kJ·m-3,which are better than those of the magnet prepared by single-main phase method(called singlemain phase magnet,SMP magnet).The diffraction peaks of the main phase of DMP magnet split in X-ray diffractometer(XRD)pattern,indicating that R2 Fe14B phases with different distributions of La/Ce elements exist in the magnet.This speculation is confirmed by transmission electron microscopy(TEM)observation.The La/Ce-rich main phase and La/Celean main phase are present in DMP magnets.The heterogeneity of rare earth elements suppresses the magnetic dilution effect in DMP magnet,and the magnetic properties are improved.Though the DMP magnet contains different main phases,it presents unitary Curie temperature(TC)of 577 K,which is higher than that of SMP magnet.This result suggests that the TC of the magnets can be promoted by double-main phase method and SPS.
基金funded by the National Sciences Foundation of China(No.81273402,81573548)
文摘Objective:Hederacolchiside A1,exhibits cytostatic and cytotoxic activity against various cancer cells in vitro,however,the mechanism is not well understood.Methods:In this study,hederacolchiside A1 from Pulsatilla chinensis was isolated and tested its anticancer activity and mechanism.Hederacolchiside A1 could inhibit proliferation of A549,SMMC-7721,BEL-7402,and MCF-7 cells by MTT assay.Investigations of apoptosis of treated cancer cells were identified in hederacolchiside A1 by flow cytometric analysis of annexin V expression.Results:Based on the results of western blotting and JC-1 staining,hederacolchiside A1 reduced the mitochondrial membrane potential and Bcl-2 protein levels,whereas cleaved caspase-3 was higher.Furthermore,hederacolchiside A1 effectively inhibited the phosphorylations of phosphatidylinositol 3 kinase(PI3K),protein kinase B(Akt),and mammalian target of rapamycin(m TOR).In vivo study showed that hederacolchiside A1(3.0,4.5,and 6.0 mg/kg,ip)could significantly inhibit the weight of tumor in anmodel.Similar inhibitory activities were observed when the compound(3.25,7.5,and15.0 mg/kg,ig)was tested in nude mice xenograft tumor models using human breast carcinoma MCF-7 cells.Conclusion:These data indicated that hederacolchiside A1 suppressed the proliferation of human tumor cells by inducing apoptosis through modulating the PI3K/Akt/m TOR signaling pathway.
基金financially supported by the National Key Research and Development Program of China (No.2016YFB0700903)the National Natural Science Foundation of China (No.51571126)+3 种基金the Inner Mongolia Innovative Research Team(No.3400102)the Innovative Science and Technology Project of Inner Mongolia (No.4140300502)the Science and Technology Project of Baotou (Nos.2012R1006 and 2015C2006-13)the Science and Technology Innovation Project of University (No.2014QDL003)
文摘The magnetic properties and microstructure of sintered R-Fe-B(R, rare earth) magnets with nominal composition of((PrNd)(1-x)MMx)(30)Fe(bal)B1(x = 0, 0.1.0.2,0.3, 0.4, 0.5 and 0.7; MM, misch metal) prepared using dual-alloy method were investigated. For x = 0.3, the maximum energy product((BH)(max)) of the sintered magnet is higher than 318.4 kJ·m^-3,but intrinsic coercivity(H(cj)) is lower than 351.8 kA·m^-1. The La and Ce contents are obviously different in some matrix-phase grains, which proves that the multi-hard magnetic phases(La, Ce-rich and La, Ce-lean) exist in the magnets. The coercivity is improved by the method of doping PrNd nanoparticles without sacrificing other magnetic properties. An enhancement in coercivity from 517.2 to 872.9 kA·m^-1 is achieved by doping 5 wt% PrNd nanoparticles. Meanwhile, it could exhibit better magnetic properties(remanence Br = 1.332 T.intrinsic coercivity H(cj)= 872.9 kA·m^-1 maximum energy product(BH)(max)=318.6 kJ·m^-3) and make the distribution of the intergranular phase become more homogeneous.
文摘This study investigated the oxidation behavior of a new casting Ni-based superalloy K4750 at 750°C-1000°C in air for 100 h-1000 h by isothermal oxidation tests.The oxidation-kinetic curves were plotted by the static discontinuous weight gain method.Observation and identification of oxidation products were conducted using scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),electron probe micro-analysis(EPMA)and X-ray diffraction(XRD).X-ray photoelectron spectrometer(XPS)was also used to analyze the chemical state of elements and the distribution in depth.The results showed that the oxidation-kinetic curves of K4750 alloy basically obeyed the parabolic law.The average oxidation rate below 900°C was less than 0.1 g/m 2·h which meant the alloy was at a complete anti-oxidation grade,and the alloy was at an anti-oxidation grade at 1000°C.The predominant surface oxide was Cr_(2)O_(3),and a double layer structure of the oxide scale was observed at all tested temperatures as time increased.The outer oxide layer contained continuous Cr_(2)O_(3)and a small amount of oxides mixed TiO2 and NiCr2O4,while the inner oxide layer was composed with Al_(2)O_(3).The oxidation process could be interpreted by the competitive oxidation of different elements.The diffusion rate of Ti through Cr_(2)O_(3)layer increased with increasing temperature,and thus the generation of TiO2 was advantageous.The dispersed TiO2 reaching a certain amount destroyed the continuity of the surface oxide layer,which accounted for the reduction of oxidation resistance of K4750 alloy at high temperatures.
文摘To the Editor:Blue rubber bleb nevus syndrome (BRBNS) is a rare systemic vascular disorder characterized by multiple venous malformations involving many organs.BRBNS can occur in various organs,but the most frequently involved organs are the skin and gastrointestinal tract.Gastrointestinal lesions of BRBNS can cause acute or chronic bleeding and anemia.[1] Only several case reports of pregnant women with BRBNS could be found in the current database and most of them were complicated by hemorrhage of the gastrointestinal tract.We report a case of BRBNS during pregnancy that suffered from severe pulmonary embolism (PE) and was successfully resuscitated.
基金National Technology Research Program for Creating New Drugs (2009ZX09308-003 and 2011ZX09201-201-16)
文摘Objective To investigate the chemical constituents from Aidi Injection.Methods The chemical constituents were isolated by chromatography on Sephadex LH-20 gel columns and reverse phase semi-preparative HPLC repeatedly.Their structures were identified by spectroscopic analysis(NMR and MS).Results Twenty-two compounds were isolated and identified to be 3-O-3′,4′-diacetyl-β-D-xylopyranosyl-6-O-β-D-glucopyranosyl- cycloastragenol(1),astragaloside IV(2),astragaloside II(3),astragaloside I(4),isoastragaloside I(5), acetylastragaloside I(6),ginsenosid Re(7),ginsenoside Rf(8),ginsenoside Rg1(9),ginsenoside Rb3(10), notoginsenoside R4(11),ginsenoside Rb1(12),ginsenoside Rc(13),ginsenoside Rb2(14),ginsenoside Rd(15), lucyoside H(16),3-O-β-D-glucopyranosyl(1→4)-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)-α-L- arabinopyranosyl oleanolic acid 28-O-α-L-rhamnopyranosyl(1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside (17),3-O-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl[β-D-glucopyranosyl-(1→4)]-(1→2)-α-L-arabinopyranosyl oleanolic acid 28-O-α-L-arabinopyranosyl(1→4)-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside(18),syringin (19),elentheroside E(20),4-(1,2,3-trihydroxypropyl)-2,6-dimethoxyphenyl-1-O-β-D-glucopyranoside(21),and coniferin(22).Conclusion Compounds 1-6 are originated from Astragalus membranceus,compounds 7-18 are originated from Panax ginseng,and compounds 19-22 are originated from Acanthopanax senticosus by LC-MS analysis.Compound 1 is a new compound.