Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic co...Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical methods.The mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural roughness.Moreover,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic modulus.The effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also revealed.This study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.展开更多
Hot isostatic pressing parameters are critical to Ti60 high temperature titanium alloy castings which have wide application perspective in aerospace.In order to obtain optimal processing parameters,the effects of hot ...Hot isostatic pressing parameters are critical to Ti60 high temperature titanium alloy castings which have wide application perspective in aerospace.In order to obtain optimal processing parameters,the effects of hot isostatic pressing parameters on defects,composition uniformity,microstructure and mechanical properties of Ti60 cast high temperature titanium alloy were investigated in detail.Results show that increasing temperature and pressure of hot isostatic pressing can reduce defects,especially,the internal defects are substantially eliminated when the temperature exceeds 920℃or the pressure exceeds 125 MPa.The higher temperature and pressure can improve the microstructure uniformity.Besides,the higher pressure can promote the composition uniformity.With the temperature increases from 880℃to 960℃,α-laths are coarsened.But with increasing pressure,the grain size of prior-βphase,the widths ofα-laths andα-colony are reduced.The tensile strength of Ti60 alloy is 949 MPa,yield strength is 827 MPa,and the elongation is 11%when the hot isostatic pressing parameters are 960℃/125 MPa/2 h,which exhibits the best match between the strength and plasticity.展开更多
AIM:To investigate the role of Rho-associated protein kinase (ROCK) inhibitor, Y27632, in mediating the production of extracellular matrix (ECM) components including fibronectin, matrix metallo-proteinase-2 (MMP-2) an...AIM:To investigate the role of Rho-associated protein kinase (ROCK) inhibitor, Y27632, in mediating the production of extracellular matrix (ECM) components including fibronectin, matrix metallo-proteinase-2 (MMP-2) and type I collagen as induced by connective tissue growth factor(CTGF) or transforming growth factor-β (TGF-β) in a human retinal pigment epithelial cell line, ARPE-19. METHODS:The effect of Y27632 on the CTGF or TGF-β induced phenotype in ARPE-19 cells was measured with immunocytochemistry as the change in F-actin. ARPE-19 cells were treated with CTGF (1, 10, 100ng/mL)and TGF-β (10ng/mL) in serum free media, and analyzed for fibronectin, laminin, and MMP-2 and type I collagen by RT-qPCR and immunocytochemistry. Cells were also pretreated with an ROCK inhibitor, Y27632, to analyze the signaling contributing to ECM production. ·RESULTS:Treatment of ARPE-19 cells in culture with TGF-β or CTGF induced an ECM change from a cobblestone morphology to a more elongated swirl pattern indicating a mesenchymal phenotype. RT-qPCR analysis and different gene expression analysis demonstrated an upregulation in expression of genes associated with cytoskeletal structure and motility. CTGFor TGF-β significantly increased expression of fibronectin mRNA (P =0.006, P =0.003 respectively), laminin mRNA (P =0.006, P =0.005), MMP-2 mRNA (P =0.006, P =0.001), COL1A1 mRNA (P =0.001, P =0.001), COL1A2 mRNA (P = 0.001, P =0.001). Preincubation of ARPE-19 with Y27632 (10mmol/L) significantly prevented CTGF or TGF-β induced fibronectin (P=0.005, P=0.003 respectively), MMP-2 (P = 0.003, P =0.002), COL1A1 (P =0.006, P =0.003), and COL1A2 (P =0.006, P =0.004) gene expression, but not laminin (P =0.375, P =0.516). CONCLUSION:Our study demonstrated that both TGF-β and CTGF upregulate the expression of ECM components including fibronectin, laminin, MMP-2 and type I collagen by activating the RhoA/ROCK signaling pathway. During this process, ARPE-19 cells were shown to change from an epithelial to a mesenchymal phenotype in vitro. Y27632, a ROCK inhibitor, inhibited the transcription of fibronectin, MMP-2 and type I collagen, but not laminin. The data from our work suggest a role for CTGF as a profibrotic mediator. Inhibiting the RhoA/ROCK pathway represents a potential target to prevent the fibrosis of retinal pigment epithelial (RPE) cells. This might lead to a novel therapeutic approach to preventing the onset of early proliferative vitreoretinopathy(PVR).展开更多
·AIM: To evaluate the reliability of β-III-Tubulin protein as a retinal ganglion cell(RGC) marker in the experimental glaucoma model.·METHODS: Glaucoma mouse models were established by injecting polystyrene...·AIM: To evaluate the reliability of β-III-Tubulin protein as a retinal ganglion cell(RGC) marker in the experimental glaucoma model.·METHODS: Glaucoma mouse models were established by injecting polystyrene microbeads into the anterior chamber of C57BL/6J mice, then their retinas were obtained 14 d and 28 d after the intraocular pressure(IOP)was elevated. Retinal flat mounts and sections were double-labeled by fluorogold(FG) and β-III-Tubulin antibody or single-labeled by β-III-Tubulin antibody,then RGCs were counted and compared respectively.· RESULTS: IOP of the injected eyes were elevated significantly and reached the peak at 22.8 ±0.7 mm Hg by day 14 after injection, then dropped to 11.3 ±0.7 mm Hg by day 28. RGC numbers counted by FG labeling and β-III- Tubulin antibody labeling were 64 807 ± 4930 and64 614 ±5054 respectively in the control group, with no significant difference. By day 14, RGCs in the experimental group decreased significantly compared to the control group, but there was no significant difference between the FG labeling counting and the β-III-Tubulin antibody labeling counting either in the experimental group or in the control group. The result was similar by day 28, with further RGC loss.·CONCLUSION: Our result suggested that the β-III-Tubulin protein was not affected by IOP elevation and can be used as a reliable marker for RGC in experimental models of glaucoma.展开更多
● AIM: To assess the neuro-protective effect of bone marrow mesenchymal stem cells(BMSCs) on retinal ganglion cells(RGCs) following optic nerve crush in mice.● METHODS: C56BL/6J mice were treated with intravitreal i...● AIM: To assess the neuro-protective effect of bone marrow mesenchymal stem cells(BMSCs) on retinal ganglion cells(RGCs) following optic nerve crush in mice.● METHODS: C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs(BIM), and GDNF-interference BMSCs(GIM) following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain m RNA or protein was detected by q-PCR or ELISA, respectively.● RESULTS: The density(cell number/mm^2) of RGCs was 410.77±56.70 in the retina 21 d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control(P <0.05). RGCs in BMSCs treated eyes was 625.07±89.64/mm2,significantly higher than that of no or PBS treatment(P<0.05). While RGCs was even less in the retina with intravitreal injection of BIM(354.07±39.77) and GIM(326.67±33.37) than that without treatment(P<0.05). BMSCs injection improved the internal BDNF expression in retinas.● CONCLUSION: Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.展开更多
Adaptive optics scanning laser ophthalmoscopy(AOSLO) has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics(AO) and AO-SLO. Then it compar...Adaptive optics scanning laser ophthalmoscopy(AOSLO) has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics(AO) and AO-SLO. Then it compares AO-SLO with conventional imaging methods(fundus fluorescein angiography, fundus autofluorescence, indocyanine green angiography and optical coherence tomography) and other AO techniques(adaptive optics flood-illumination ophthalmoscopy and adaptive optics optical coherence tomography). Furthermore, an update of current research situation in AO-SLO is made based on different fundus structures as photoreceptors(cones and rods), fundus vessels, retinal pigment epithelium layer, retinal nerve fiber layer, ganglion cell layer and lamina cribrosa. Finally, this review indicates possible research directions of AO-SLO in future.展开更多
AIM: To explore the pathogenesis of asymmetric primary open angle glaucoma(POAG) in both eyes by comparing the intraocular pressure(IOP) of patients who sleep in different positions and to investigate the relationship...AIM: To explore the pathogenesis of asymmetric primary open angle glaucoma(POAG) in both eyes by comparing the intraocular pressure(IOP) of patients who sleep in different positions and to investigate the relationship between IOP variations and sleep positions.METHODS: One hundred and thirty-one patients with asymmetric POAG and forty-six healthy volunteers were enrolled. All participants completed a questionnaire that provided information about their sleep laterality. The cup disc ratio(C/D) and visual field defect established binocular asymmetry. The IOP of both eyes was measured using i Care parameters after the patients were asked to change body position. The "worse" and "better" eyes were identified according to the diagnosis, whereas the "dependent" and "independent" eyes were defined according to the lateral position. RESULTS: No significant difference in sleep laterality was observed between healthy people and patients with POAG(F=3.195, P=0.362). Among the enrolled patients, the IOP of the dependent eye was always greater than that of the independent eye in the lateral position(P<0.05). In the patients with binocular asymmetric POAG, the questionnaire clearly showed that 85.7% of left side preferences were found their left eyes to be the worse eyes and the right eyes of 71.4% patients with a right side preference were the more serious. When the asymmetric C/D ratio was greater than or equal to 0.2, the worse eye of patients with POAG and a preferred sleeping position was the dependent eye(χ~2=16.762, P=0.001).CONCLUSION: A higher IOP was measured in the dependent eye in the lateral position. The long-term tendency to choose a lateral sleeping position might lead the dependent eye to manifest more severe symptoms than the independent eye. Thus, the lateral sleeping position might be one cause of asymmetric POAG.展开更多
BACKGROUND Budd-Chiari syndrome(BCS)is an uncommon disorder characterized by obstruction of hepatic venous outflow.To date,the exact mechanism underlying hepatic injury derived from the hepatic venous outflow obstruct...BACKGROUND Budd-Chiari syndrome(BCS)is an uncommon disorder characterized by obstruction of hepatic venous outflow.To date,the exact mechanism underlying hepatic injury derived from the hepatic venous outflow obstruction in BCS remains largely unknown.AIM To assess the role of NF-κB-mediated inflammation in BCS-induced liver injury in humans and rats.METHODS A total of 180 rats were randomly assigned into nine groups,including four BCS model groups(1,3,6 and 12 wk),four sham-operated groups(1,3,6 and 12 wk),and a control group.Lipopolysaccharide(LPS)levels in each group were detected by the Tachypleus Amebocyte Lysate assay.The mRNA and protein levels of TLR4,NF-κB,tumor necrosis factor(TNF)-α,interleukin(IL)-2 and interferon(IFN)-γwere quantified.In addition,60 patients with BCS and 30 healthy controls were enrolled,and their blood samples were analyzed.RESULTS Hepatic and plasma LPS levels were significantly increased in rats.The mRNA and protein expression levels of TLR4,NF-κB and inflammatory cytokines(TNF-α,IL-2 and IFN-γ)in liver tissues were significantly higher in the BCS model groups compared with the other two groups.In addition,the model groups(1,3,6 and 12 wk after BCS induction)showed significant differences in the levels of LPS,TLR4,NF-κB,TNF-α,IL-2 and IFN-γ.Notably,there was a significant correlation between the LPS concentrations and mRNA and protein levels of TLR4,NF-κB and inflammatory cytokines.Importantly,it was revealed that the levels of LPS,TLR4,NF-κB and inflammatory cytokines were significantly greater in chronic BCS patients than healthy controls and acute BCS patients.CONCLUSION LPS level is markedly elevated in BCS,in turn activating the TLR4/NF-κB signaling pathway,leading to induction of inflammatory cytokines(TNF-α,IL-2 and IFN-γ)in response to BCS-induced liver injury.展开更多
The existing decoy-state quantum key distribution(QKD)beating photon-number-splitting(PNS)attack provides a more accurate method to estimate the secure key rate,while it still considers that only single-photon pulses ...The existing decoy-state quantum key distribution(QKD)beating photon-number-splitting(PNS)attack provides a more accurate method to estimate the secure key rate,while it still considers that only single-photon pulses can generate secure keys in any case.However,multiphoton pulses can also generate secure keys if we can detect the possibility of PNS attack in the channel.The ultimate goal of this line of research is to confirm the absence of all types of PNS attacks.In particular,the PNS attack mentioned and detected in this paper is only the weaker version of PNS attack which significantly changes the observed values of the legitimate users.In this paper,under the null hypothesis of no weaker version of PNS attack,we first determine whether there is an attack or not by retrieving the missing information of the existing decoy-state protocols,extract a Cauchy distribution statistic,and further provide a detection method and the type I error probability.If the result is judged to be an attack,we can use the existing decoy-state method and the GLLP formula to estimate the secure key rate.Otherwise,the pulses with the same basis received including both single-photon pulses and multiphoton pulses,can be used to generate the keys and we give the secure key rate in this case.Finally,the associated experiments we performed(i.e.,the significance level is 5%)show the correctness of our method.展开更多
BACKGROUND Many ant species can harm humans;however,only a few cause life-threatening allergic reactions.Normally,reactions caused by ants occur in patients who come into contact with ant venom.Venom contains various ...BACKGROUND Many ant species can harm humans;however,only a few cause life-threatening allergic reactions.Normally,reactions caused by ants occur in patients who come into contact with ant venom.Venom contains various biologically active peptides and protein components,of which acids and alkaloids tend to cause anaphylaxis.Ant venom can cause both immediate and delayed reactions.The main histopathological changes observed in ant hypersensitivity are eosinophil recruitment and Th2 cytokine production.CASE SUMMARY A 70-year-old man was bitten by a large number of ants when he was in a drunken stupor and was hospitalized at a local hospital.Five days later,because of severe symptoms,the patient was transferred to our hospital for treatment.Numerous pustules were observed interspersed throughout the body,with itching and pain reported.He had experienced fever,vomiting,hematochezia,mania,soliloquy,sleep disturbances,and elevated levels of myocardial enzymes since the onset of illness.The patient had a history of hypertension for more than 1 year,and his blood pressure was within the normal range after hypotensive drug treatment.He had no other relevant medical history.Based on the clinical history of an ant bite and its clinical manifestations,the patient was diagnosed with an ant venom allergy.The patient was treated with 60 mg methylprednisolone for 2 d,40 mg methylprednisolone for 3 d,and 20 mg methylprednisolone for 2 d.Oral antihistamines and diazepam were administered for 12 d and 8 d,respectively.Cold compresses were used to treat the swelling during the process.After 12 d of treatment,most pustules became crusts,whereas some had faded away.No symptoms of pain,itching,or psychological disturbances were reported during the follow-up visits within 6 mo.CONCLUSION This case report emphasizes the dangers of ant stings.展开更多
AIM:To assess the effectiveness of immunosuppressants in the prophylaxis of corneal allograft rejection after high-risk keratoplasty and normal-risk keratoplasty.METHODS:We searched the Cochrane Central Register of Co...AIM:To assess the effectiveness of immunosuppressants in the prophylaxis of corneal allograft rejection after high-risk keratoplasty and normal-risk keratoplasty.METHODS:We searched the Cochrane Central Register of Controlled Trials(CENTRAL),MEDLINE,EMBASE,CNKI,VIP and reference lists of articles.Date of most recent search:18 June,2011.All randomised controlled trials(RCTs) assessing the use of immunosupressants in the prevention of graft rejection,irrespective of publication language.Two authors assessed trial quality and extracted data independently.Only dichotomous outcomes(clear graft survival,ratio of immune reactions and side effects) were available and were expressed as relative risk(RR) and 95% confidence intervals(CI).RESULTS:Seven studies were included in this review.In the comparing of mycophenolate mofetil(MMF) with placebo,the results showed MMF could significantly reduce immune reactions compared with placebo(RR 1.08 95% Cl 0.95 to 1.21),but no effect on clear graft survival(RR 1.11 95% Cl 0.90 to 1.35).In clear graft survival and immune reactions,MMF and cyclosporine A(CsA) showed similar effect(RR 1.11 95% Cl 0.90 to 1.35,and RR 1.48,95% Cl 0.56 to 3.93,respectively).Tacrolimus(FK506) and steroid showed similar effects on clear graft survival and immune reactions(RR 0.32,95% CI 0.02 to 6.21,and RR 1.00,95%CI 0.88 to 1.14,respectively).No drug relative side effect has been found.CONCLUSION:MMF may reduce immune reactions in both normal-risk and high-risk rejection of penetrating keratoplasty.CsA and FK506 showed similar effects as MMF.However,due to the lack of large clinical trials,the evidence remain weak,the quality of evidences were rated as very low to moderate.Large,properly randomised,placebo-controlled,double masked trials are needed to evaluate the effect of immunosuppressants.展开更多
High-entropy alloys(HEAs)are based on solid solutions which characterized by chemical short-range ordering(CSRO),but there is no accurate structural tool to address CSRO characteristic,which obstacles precise composit...High-entropy alloys(HEAs)are based on solid solutions which characterized by chemical short-range ordering(CSRO),but there is no accurate structural tool to address CSRO characteristic,which obstacles precise composition design for HEAs.In this study,based on the cluster-plus-glue-atoms model,the composition law of Al-TMs(TMs,transition metals)HEAs with BCC and FCC structures was revealed.In BCC structure,with five elements in equi-atomic ratio,the composition formula of Al-TMs HEAs can be expressed by a cluster formula[Al-M_(14)]Al_(3),and in non equi-atomic ratio can be expressed by[Al-M_(14)]Al,where M is the average atom of the TMs.But in FCC structure,both Al-TMs HEAs with five elements in equiatomic and non equi-atomic ratios can be expressed by a cluster formula[Al-M_(12)]Al.To confirm the effectiveness of cluster formula for Al-TMs,two alloys were designed,[Al-Ti_(4)V_(3)Nb_(4)Mo_(3)]Mo and[Al-Ti_(3)V_(3)Nb_(4)Mo_(4)]Al.Results show that the[Al-Ti_(3)V_(3)Nb_(4)Mo_(4)]Al alloy has both higher strength and higher plastic deformation at room temperature.Besides,[Al-Ti_(3)V_(3)Nb_(4)Mo_(4)]Al alloy shows slower soften effect at 800℃,contributed to its higher strength.By substituting Ta for some of Mo,the strength of[Al-Ti_(3)V_(3)Nb_(4)Mo_(3)Ta]Al at room temperature and high temperature drastically decreases,suggesting that Ta element deteriorates the properties of Al-TMs alloys.展开更多
Cycloaddition of CO_(2) and epoxide into cyclic carbonate is one of the most efficient ways for CO_(2) conversion with 100% atom-utilization. Metal–organic frameworks are a kind of potential heterogeneous catalysts, ...Cycloaddition of CO_(2) and epoxide into cyclic carbonate is one of the most efficient ways for CO_(2) conversion with 100% atom-utilization. Metal–organic frameworks are a kind of potential heterogeneous catalysts, however, high temperature, high pressure, and high-purity CO_(2) are still required for the reaction.Here, we report two new Zn(Ⅱ) imidazolate frameworks incoporating MoO_(4)^(2–)or WO_(4)^(2–)units, which can catalyse cycloaddition of CO_(2) and epichlorohydrin at room temperature and atomospheric pressure, giving 95% yield after 24 h in pure CO_(2) and 98% yield after 48 h in simulated flue gas(15% CO_(2)+ 85% N_(2)),respectively. For comparison, the analogic Zn(Ⅱ) imidazolate framework MAF-6 without non-3d metal oxide units showed 71% and 33% yields under the same conditions, respectively. The insightful modulation mechanisms of the MoO_(4)^(2–)unit in optimizing the electronic structure of Zn(Ⅱ) centre, facilitating the rate-determined ring opening process, and minimizing the reaction activation energy, were revealed by X-ray photoelectron spectroscopy, temperature programmed desorption and computational calculations.展开更多
Understanding phase transitions in multi-component crystals is of importance for regulating specified functional materials.Herein,we present two new organic-inorganic hybrid crystals,(Me_(3)NCH_(2)CH_(2)X)_(4)[Ni(NCS)...Understanding phase transitions in multi-component crystals is of importance for regulating specified functional materials.Herein,we present two new organic-inorganic hybrid crystals,(Me_(3)NCH_(2)CH_(2)X)_(4)[Ni(NCS)_6](X=Cl and Br),revealing distinct phase transitions.Specifically,the Clsubstituted cations weakly interact with discrete inorganic part hence reveal step-wise dynamic changes upon heating,which result in multi-step solid-solid phase transitions (P1-P2_1/n-A2/a-Cmce) including a ferroelastic one with a spontaneous strain of 0.0475.Whereas the Br-substituted cations with larger steric effect prevent the solid-solid phase transition but give a solid-liquid phase transition at above 419 K.The present instances well demonstrate the complicity for multi-component crystals arising from the delicate balance established by abundant weak intermolecular interactions,and inspire the design of novel phase-transition materials by judiciously assembling multi-component crystals.展开更多
Inorganic solids are a kind of important catalysts,and their activities usually come from sparse active sites,which are structurally different from inactive bulk.Therefore,the rational optimization of activity depends...Inorganic solids are a kind of important catalysts,and their activities usually come from sparse active sites,which are structurally different from inactive bulk.Therefore,the rational optimization of activity depends on studying these active sites.Copper is a widely used catalyst and is expected to be a promising catalyst for the electroreduction of CO_(2) to C_(2)H_(4).展开更多
Technological application of the electrochemical reduction of CO_(2)relies on efficient electrocatalysts.We demonstrate that the introduction of amino groups alongside the porphyrin cobalt centers in a metal-organic f...Technological application of the electrochemical reduction of CO_(2)relies on efficient electrocatalysts.We demonstrate that the introduction of amino groups alongside the porphyrin cobalt centers in a metal-organic framework(MOF)can dramatically accelerate the electrochemical CO_(2)reduction performance.A classic cobalt porphyrin-based MOF showing moderate CO_(2)-to-CO electroreduction performance(turnover frequency[TOF]=0.20 s^(−1),Faradic efficiency[FE]=47.4%)is modified.By molecular design of the porphyrin-based ligand,amino groups are introduced alongside the cobalt center,giving remarkably enhanced CO_(2)-to-CO electroreduction performance as high as FE 99.4%,current density 7.2 mA cm^(−2),and TOF 21.17 s^(−1),in a nearneutral aqueous solution at a low overpotential of 525 mV.Density functional theory calculations showed that the prepositioned amino groups,although located not sufficiently close to the active center,serve as hydrogen-bonding donors to stabilize the intermediate Co-CO_(2)adduct and impede the formation of Co-H_(2)O adduct,which not only promotes the CO_(2)reduction reaction but also restrains the hydrogen evolution reaction.展开更多
基金This work is financially supported by the Key Laboratory of Icing and Anti/De-icing of CARDC(Grant No.IADL20210402)the National Natural Science Foundation of China(Grant Nos.12002350,12172314,11772278 and 11904300)+1 种基金the Jiangxi Provincial Outstanding Young Talents Program(Grant No.20192BCBL23029)the Fundamental Research Funds for the Central Universities(Xiamen University:Grant No.20720210025).
文摘Understanding the hydrate adhesion is important to tackling hydrate accretion in petro-pipelines.Herein,the relationship between the Tetrahydrofuran(THF)hydrate adhesion strength(AS)and surface stiffness on elastic coatings is systemically examined by experimental shear force measurements and theoretical methods.The mechanical factor-elastic modulus of the coatings greatly dictates the hydrate AS,which is explained by the adhesion mechanics theory,beyond the usual factors such as wettability and structural roughness.Moreover,the hydrate AS increases with reducing the thickness of the elastic coatings,resulted from the decrease of the apparent surface elastic modulus.The effect of critical thickness for the elastic materials with variable elastic modulus on the hydrate AS is also revealed.This study provides deep perspectives on the regulation of the hydrate AS by the elastic modulus of elastic materials,which is of significance to design anti-hydrate surfaces for mitigation of hydrate accretion in petro-pipelines.
基金financially supported by the National Key Research and Development Program of China(Grant No.2020YFB2008300)。
文摘Hot isostatic pressing parameters are critical to Ti60 high temperature titanium alloy castings which have wide application perspective in aerospace.In order to obtain optimal processing parameters,the effects of hot isostatic pressing parameters on defects,composition uniformity,microstructure and mechanical properties of Ti60 cast high temperature titanium alloy were investigated in detail.Results show that increasing temperature and pressure of hot isostatic pressing can reduce defects,especially,the internal defects are substantially eliminated when the temperature exceeds 920℃or the pressure exceeds 125 MPa.The higher temperature and pressure can improve the microstructure uniformity.Besides,the higher pressure can promote the composition uniformity.With the temperature increases from 880℃to 960℃,α-laths are coarsened.But with increasing pressure,the grain size of prior-βphase,the widths ofα-laths andα-colony are reduced.The tensile strength of Ti60 alloy is 949 MPa,yield strength is 827 MPa,and the elongation is 11%when the hot isostatic pressing parameters are 960℃/125 MPa/2 h,which exhibits the best match between the strength and plasticity.
文摘AIM:To investigate the role of Rho-associated protein kinase (ROCK) inhibitor, Y27632, in mediating the production of extracellular matrix (ECM) components including fibronectin, matrix metallo-proteinase-2 (MMP-2) and type I collagen as induced by connective tissue growth factor(CTGF) or transforming growth factor-β (TGF-β) in a human retinal pigment epithelial cell line, ARPE-19. METHODS:The effect of Y27632 on the CTGF or TGF-β induced phenotype in ARPE-19 cells was measured with immunocytochemistry as the change in F-actin. ARPE-19 cells were treated with CTGF (1, 10, 100ng/mL)and TGF-β (10ng/mL) in serum free media, and analyzed for fibronectin, laminin, and MMP-2 and type I collagen by RT-qPCR and immunocytochemistry. Cells were also pretreated with an ROCK inhibitor, Y27632, to analyze the signaling contributing to ECM production. ·RESULTS:Treatment of ARPE-19 cells in culture with TGF-β or CTGF induced an ECM change from a cobblestone morphology to a more elongated swirl pattern indicating a mesenchymal phenotype. RT-qPCR analysis and different gene expression analysis demonstrated an upregulation in expression of genes associated with cytoskeletal structure and motility. CTGFor TGF-β significantly increased expression of fibronectin mRNA (P =0.006, P =0.003 respectively), laminin mRNA (P =0.006, P =0.005), MMP-2 mRNA (P =0.006, P =0.001), COL1A1 mRNA (P =0.001, P =0.001), COL1A2 mRNA (P = 0.001, P =0.001). Preincubation of ARPE-19 with Y27632 (10mmol/L) significantly prevented CTGF or TGF-β induced fibronectin (P=0.005, P=0.003 respectively), MMP-2 (P = 0.003, P =0.002), COL1A1 (P =0.006, P =0.003), and COL1A2 (P =0.006, P =0.004) gene expression, but not laminin (P =0.375, P =0.516). CONCLUSION:Our study demonstrated that both TGF-β and CTGF upregulate the expression of ECM components including fibronectin, laminin, MMP-2 and type I collagen by activating the RhoA/ROCK signaling pathway. During this process, ARPE-19 cells were shown to change from an epithelial to a mesenchymal phenotype in vitro. Y27632, a ROCK inhibitor, inhibited the transcription of fibronectin, MMP-2 and type I collagen, but not laminin. The data from our work suggest a role for CTGF as a profibrotic mediator. Inhibiting the RhoA/ROCK pathway represents a potential target to prevent the fibrosis of retinal pigment epithelial (RPE) cells. This might lead to a novel therapeutic approach to preventing the onset of early proliferative vitreoretinopathy(PVR).
基金Supported by National Natural Science Foundation of China (No.81270993, No. 81200687)National Major Scientific Equipment Program (No. 2012YQ12008005)Science and Technology Support Program of Sichuan (No. 2013FZ0055)
文摘·AIM: To evaluate the reliability of β-III-Tubulin protein as a retinal ganglion cell(RGC) marker in the experimental glaucoma model.·METHODS: Glaucoma mouse models were established by injecting polystyrene microbeads into the anterior chamber of C57BL/6J mice, then their retinas were obtained 14 d and 28 d after the intraocular pressure(IOP)was elevated. Retinal flat mounts and sections were double-labeled by fluorogold(FG) and β-III-Tubulin antibody or single-labeled by β-III-Tubulin antibody,then RGCs were counted and compared respectively.· RESULTS: IOP of the injected eyes were elevated significantly and reached the peak at 22.8 ±0.7 mm Hg by day 14 after injection, then dropped to 11.3 ±0.7 mm Hg by day 28. RGC numbers counted by FG labeling and β-III- Tubulin antibody labeling were 64 807 ± 4930 and64 614 ±5054 respectively in the control group, with no significant difference. By day 14, RGCs in the experimental group decreased significantly compared to the control group, but there was no significant difference between the FG labeling counting and the β-III-Tubulin antibody labeling counting either in the experimental group or in the control group. The result was similar by day 28, with further RGC loss.·CONCLUSION: Our result suggested that the β-III-Tubulin protein was not affected by IOP elevation and can be used as a reliable marker for RGC in experimental models of glaucoma.
基金Supported by the National Major Scientific Equipment program(No.2012YQ12008005)the Institute of Neurological Disease,West China Hospital,Sichuan University
文摘● AIM: To assess the neuro-protective effect of bone marrow mesenchymal stem cells(BMSCs) on retinal ganglion cells(RGCs) following optic nerve crush in mice.● METHODS: C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs(BIM), and GDNF-interference BMSCs(GIM) following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain m RNA or protein was detected by q-PCR or ELISA, respectively.● RESULTS: The density(cell number/mm^2) of RGCs was 410.77±56.70 in the retina 21 d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control(P <0.05). RGCs in BMSCs treated eyes was 625.07±89.64/mm2,significantly higher than that of no or PBS treatment(P<0.05). While RGCs was even less in the retina with intravitreal injection of BIM(354.07±39.77) and GIM(326.67±33.37) than that without treatment(P<0.05). BMSCs injection improved the internal BDNF expression in retinas.● CONCLUSION: Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.
基金Supported by National Key Scientific Instrument and Equipment Development Project of China (No.2012YQ12008005)
文摘Adaptive optics scanning laser ophthalmoscopy(AOSLO) has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics(AO) and AO-SLO. Then it compares AO-SLO with conventional imaging methods(fundus fluorescein angiography, fundus autofluorescence, indocyanine green angiography and optical coherence tomography) and other AO techniques(adaptive optics flood-illumination ophthalmoscopy and adaptive optics optical coherence tomography). Furthermore, an update of current research situation in AO-SLO is made based on different fundus structures as photoreceptors(cones and rods), fundus vessels, retinal pigment epithelium layer, retinal nerve fiber layer, ganglion cell layer and lamina cribrosa. Finally, this review indicates possible research directions of AO-SLO in future.
基金Supported by the National Major Scientific Equipment Program (NO.2012YQ12008005)the Health Research Funding of Sichuan Province in 2017 (No.17PJ539)
文摘AIM: To explore the pathogenesis of asymmetric primary open angle glaucoma(POAG) in both eyes by comparing the intraocular pressure(IOP) of patients who sleep in different positions and to investigate the relationship between IOP variations and sleep positions.METHODS: One hundred and thirty-one patients with asymmetric POAG and forty-six healthy volunteers were enrolled. All participants completed a questionnaire that provided information about their sleep laterality. The cup disc ratio(C/D) and visual field defect established binocular asymmetry. The IOP of both eyes was measured using i Care parameters after the patients were asked to change body position. The "worse" and "better" eyes were identified according to the diagnosis, whereas the "dependent" and "independent" eyes were defined according to the lateral position. RESULTS: No significant difference in sleep laterality was observed between healthy people and patients with POAG(F=3.195, P=0.362). Among the enrolled patients, the IOP of the dependent eye was always greater than that of the independent eye in the lateral position(P<0.05). In the patients with binocular asymmetric POAG, the questionnaire clearly showed that 85.7% of left side preferences were found their left eyes to be the worse eyes and the right eyes of 71.4% patients with a right side preference were the more serious. When the asymmetric C/D ratio was greater than or equal to 0.2, the worse eye of patients with POAG and a preferred sleeping position was the dependent eye(χ~2=16.762, P=0.001).CONCLUSION: A higher IOP was measured in the dependent eye in the lateral position. The long-term tendency to choose a lateral sleeping position might lead the dependent eye to manifest more severe symptoms than the independent eye. Thus, the lateral sleeping position might be one cause of asymmetric POAG.
基金Natural Science Foundation Project of Anhui Province,No.1708085QH218。
文摘BACKGROUND Budd-Chiari syndrome(BCS)is an uncommon disorder characterized by obstruction of hepatic venous outflow.To date,the exact mechanism underlying hepatic injury derived from the hepatic venous outflow obstruction in BCS remains largely unknown.AIM To assess the role of NF-κB-mediated inflammation in BCS-induced liver injury in humans and rats.METHODS A total of 180 rats were randomly assigned into nine groups,including four BCS model groups(1,3,6 and 12 wk),four sham-operated groups(1,3,6 and 12 wk),and a control group.Lipopolysaccharide(LPS)levels in each group were detected by the Tachypleus Amebocyte Lysate assay.The mRNA and protein levels of TLR4,NF-κB,tumor necrosis factor(TNF)-α,interleukin(IL)-2 and interferon(IFN)-γwere quantified.In addition,60 patients with BCS and 30 healthy controls were enrolled,and their blood samples were analyzed.RESULTS Hepatic and plasma LPS levels were significantly increased in rats.The mRNA and protein expression levels of TLR4,NF-κB and inflammatory cytokines(TNF-α,IL-2 and IFN-γ)in liver tissues were significantly higher in the BCS model groups compared with the other two groups.In addition,the model groups(1,3,6 and 12 wk after BCS induction)showed significant differences in the levels of LPS,TLR4,NF-κB,TNF-α,IL-2 and IFN-γ.Notably,there was a significant correlation between the LPS concentrations and mRNA and protein levels of TLR4,NF-κB and inflammatory cytokines.Importantly,it was revealed that the levels of LPS,TLR4,NF-κB and inflammatory cytokines were significantly greater in chronic BCS patients than healthy controls and acute BCS patients.CONCLUSION LPS level is markedly elevated in BCS,in turn activating the TLR4/NF-κB signaling pathway,leading to induction of inflammatory cytokines(TNF-α,IL-2 and IFN-γ)in response to BCS-induced liver injury.
文摘The existing decoy-state quantum key distribution(QKD)beating photon-number-splitting(PNS)attack provides a more accurate method to estimate the secure key rate,while it still considers that only single-photon pulses can generate secure keys in any case.However,multiphoton pulses can also generate secure keys if we can detect the possibility of PNS attack in the channel.The ultimate goal of this line of research is to confirm the absence of all types of PNS attacks.In particular,the PNS attack mentioned and detected in this paper is only the weaker version of PNS attack which significantly changes the observed values of the legitimate users.In this paper,under the null hypothesis of no weaker version of PNS attack,we first determine whether there is an attack or not by retrieving the missing information of the existing decoy-state protocols,extract a Cauchy distribution statistic,and further provide a detection method and the type I error probability.If the result is judged to be an attack,we can use the existing decoy-state method and the GLLP formula to estimate the secure key rate.Otherwise,the pulses with the same basis received including both single-photon pulses and multiphoton pulses,can be used to generate the keys and we give the secure key rate in this case.Finally,the associated experiments we performed(i.e.,the significance level is 5%)show the correctness of our method.
文摘BACKGROUND Many ant species can harm humans;however,only a few cause life-threatening allergic reactions.Normally,reactions caused by ants occur in patients who come into contact with ant venom.Venom contains various biologically active peptides and protein components,of which acids and alkaloids tend to cause anaphylaxis.Ant venom can cause both immediate and delayed reactions.The main histopathological changes observed in ant hypersensitivity are eosinophil recruitment and Th2 cytokine production.CASE SUMMARY A 70-year-old man was bitten by a large number of ants when he was in a drunken stupor and was hospitalized at a local hospital.Five days later,because of severe symptoms,the patient was transferred to our hospital for treatment.Numerous pustules were observed interspersed throughout the body,with itching and pain reported.He had experienced fever,vomiting,hematochezia,mania,soliloquy,sleep disturbances,and elevated levels of myocardial enzymes since the onset of illness.The patient had a history of hypertension for more than 1 year,and his blood pressure was within the normal range after hypotensive drug treatment.He had no other relevant medical history.Based on the clinical history of an ant bite and its clinical manifestations,the patient was diagnosed with an ant venom allergy.The patient was treated with 60 mg methylprednisolone for 2 d,40 mg methylprednisolone for 3 d,and 20 mg methylprednisolone for 2 d.Oral antihistamines and diazepam were administered for 12 d and 8 d,respectively.Cold compresses were used to treat the swelling during the process.After 12 d of treatment,most pustules became crusts,whereas some had faded away.No symptoms of pain,itching,or psychological disturbances were reported during the follow-up visits within 6 mo.CONCLUSION This case report emphasizes the dangers of ant stings.
文摘AIM:To assess the effectiveness of immunosuppressants in the prophylaxis of corneal allograft rejection after high-risk keratoplasty and normal-risk keratoplasty.METHODS:We searched the Cochrane Central Register of Controlled Trials(CENTRAL),MEDLINE,EMBASE,CNKI,VIP and reference lists of articles.Date of most recent search:18 June,2011.All randomised controlled trials(RCTs) assessing the use of immunosupressants in the prevention of graft rejection,irrespective of publication language.Two authors assessed trial quality and extracted data independently.Only dichotomous outcomes(clear graft survival,ratio of immune reactions and side effects) were available and were expressed as relative risk(RR) and 95% confidence intervals(CI).RESULTS:Seven studies were included in this review.In the comparing of mycophenolate mofetil(MMF) with placebo,the results showed MMF could significantly reduce immune reactions compared with placebo(RR 1.08 95% Cl 0.95 to 1.21),but no effect on clear graft survival(RR 1.11 95% Cl 0.90 to 1.35).In clear graft survival and immune reactions,MMF and cyclosporine A(CsA) showed similar effect(RR 1.11 95% Cl 0.90 to 1.35,and RR 1.48,95% Cl 0.56 to 3.93,respectively).Tacrolimus(FK506) and steroid showed similar effects on clear graft survival and immune reactions(RR 0.32,95% CI 0.02 to 6.21,and RR 1.00,95%CI 0.88 to 1.14,respectively).No drug relative side effect has been found.CONCLUSION:MMF may reduce immune reactions in both normal-risk and high-risk rejection of penetrating keratoplasty.CsA and FK506 showed similar effects as MMF.However,due to the lack of large clinical trials,the evidence remain weak,the quality of evidences were rated as very low to moderate.Large,properly randomised,placebo-controlled,double masked trials are needed to evaluate the effect of immunosuppressants.
基金supported by the National Key Research and Development Program of China(Grant Nos.2020YFB2008305,2020YFB2008303).
文摘High-entropy alloys(HEAs)are based on solid solutions which characterized by chemical short-range ordering(CSRO),but there is no accurate structural tool to address CSRO characteristic,which obstacles precise composition design for HEAs.In this study,based on the cluster-plus-glue-atoms model,the composition law of Al-TMs(TMs,transition metals)HEAs with BCC and FCC structures was revealed.In BCC structure,with five elements in equi-atomic ratio,the composition formula of Al-TMs HEAs can be expressed by a cluster formula[Al-M_(14)]Al_(3),and in non equi-atomic ratio can be expressed by[Al-M_(14)]Al,where M is the average atom of the TMs.But in FCC structure,both Al-TMs HEAs with five elements in equiatomic and non equi-atomic ratios can be expressed by a cluster formula[Al-M_(12)]Al.To confirm the effectiveness of cluster formula for Al-TMs,two alloys were designed,[Al-Ti_(4)V_(3)Nb_(4)Mo_(3)]Mo and[Al-Ti_(3)V_(3)Nb_(4)Mo_(4)]Al.Results show that the[Al-Ti_(3)V_(3)Nb_(4)Mo_(4)]Al alloy has both higher strength and higher plastic deformation at room temperature.Besides,[Al-Ti_(3)V_(3)Nb_(4)Mo_(4)]Al alloy shows slower soften effect at 800℃,contributed to its higher strength.By substituting Ta for some of Mo,the strength of[Al-Ti_(3)V_(3)Nb_(4)Mo_(3)Ta]Al at room temperature and high temperature drastically decreases,suggesting that Ta element deteriorates the properties of Al-TMs alloys.
基金supported by the National Natural Science Foundation of China (Nos. 22090061, 21731007, 21890380 and 22161021)the Guangdong Pearl River Talents Program (No. 2017BT01C161)the support of Jiangxi Province (No. jxsq2018106041)。
文摘Cycloaddition of CO_(2) and epoxide into cyclic carbonate is one of the most efficient ways for CO_(2) conversion with 100% atom-utilization. Metal–organic frameworks are a kind of potential heterogeneous catalysts, however, high temperature, high pressure, and high-purity CO_(2) are still required for the reaction.Here, we report two new Zn(Ⅱ) imidazolate frameworks incoporating MoO_(4)^(2–)or WO_(4)^(2–)units, which can catalyse cycloaddition of CO_(2) and epichlorohydrin at room temperature and atomospheric pressure, giving 95% yield after 24 h in pure CO_(2) and 98% yield after 48 h in simulated flue gas(15% CO_(2)+ 85% N_(2)),respectively. For comparison, the analogic Zn(Ⅱ) imidazolate framework MAF-6 without non-3d metal oxide units showed 71% and 33% yields under the same conditions, respectively. The insightful modulation mechanisms of the MoO_(4)^(2–)unit in optimizing the electronic structure of Zn(Ⅱ) centre, facilitating the rate-determined ring opening process, and minimizing the reaction activation energy, were revealed by X-ray photoelectron spectroscopy, temperature programmed desorption and computational calculations.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.22071273 and 21821003)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01C161)。
文摘Understanding phase transitions in multi-component crystals is of importance for regulating specified functional materials.Herein,we present two new organic-inorganic hybrid crystals,(Me_(3)NCH_(2)CH_(2)X)_(4)[Ni(NCS)_6](X=Cl and Br),revealing distinct phase transitions.Specifically,the Clsubstituted cations weakly interact with discrete inorganic part hence reveal step-wise dynamic changes upon heating,which result in multi-step solid-solid phase transitions (P1-P2_1/n-A2/a-Cmce) including a ferroelastic one with a spontaneous strain of 0.0475.Whereas the Br-substituted cations with larger steric effect prevent the solid-solid phase transition but give a solid-liquid phase transition at above 419 K.The present instances well demonstrate the complicity for multi-component crystals arising from the delicate balance established by abundant weak intermolecular interactions,and inspire the design of novel phase-transition materials by judiciously assembling multi-component crystals.
基金This work was supported by the NSFC(21890380 and 21821003)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01C16i)the Science and Technology Key Project of Guangdong Province,China(2020B010188002)。
文摘Inorganic solids are a kind of important catalysts,and their activities usually come from sparse active sites,which are structurally different from inactive bulk.Therefore,the rational optimization of activity depends on studying these active sites.Copper is a widely used catalyst and is expected to be a promising catalyst for the electroreduction of CO_(2) to C_(2)H_(4).
基金This research was supported by the National Key Research and Development Program of China(grant no.2021YFA1500401)the National Natural Science Foundation of China(grant nos.21890380,21821003,22071272,21975290,and 21731007)+1 种基金the Guangdong Pearl River Talents Program(grant no.2017BT01C161)the Guangdong Natural Science Funds for Distinguished Young Scholar(grant no.2018B030306009).
文摘Technological application of the electrochemical reduction of CO_(2)relies on efficient electrocatalysts.We demonstrate that the introduction of amino groups alongside the porphyrin cobalt centers in a metal-organic framework(MOF)can dramatically accelerate the electrochemical CO_(2)reduction performance.A classic cobalt porphyrin-based MOF showing moderate CO_(2)-to-CO electroreduction performance(turnover frequency[TOF]=0.20 s^(−1),Faradic efficiency[FE]=47.4%)is modified.By molecular design of the porphyrin-based ligand,amino groups are introduced alongside the cobalt center,giving remarkably enhanced CO_(2)-to-CO electroreduction performance as high as FE 99.4%,current density 7.2 mA cm^(−2),and TOF 21.17 s^(−1),in a nearneutral aqueous solution at a low overpotential of 525 mV.Density functional theory calculations showed that the prepositioned amino groups,although located not sufficiently close to the active center,serve as hydrogen-bonding donors to stabilize the intermediate Co-CO_(2)adduct and impede the formation of Co-H_(2)O adduct,which not only promotes the CO_(2)reduction reaction but also restrains the hydrogen evolution reaction.
