ABSTRACT
A built-in electric field in electrocatalyst can significantly accumulate higher concentration of NO3 - ions near electrocatalyst surface region, thus facilitating mass transfer for efficient nitrate removal at ultra-low concentration and electroreduction reaction (NO3 RR). A model electrocatalyst is created by stacking CuCl (111) and rutile TiO2 (110) layers together, in which a built-in electric field induced from the electron transfer from TiO2 to CuCl (CuCl_BEF) is successfully formed . This built-in electric field effectively triggers interfacial accumulation of NO3 - ions around the electrocatalyst. The electric field also raises the energy of key reaction intermediate *NO to lower the energy barrier of the rate determining step. A NH3 product selectivity of 98.6 %, a low NO2 - production of <0.6 %, and mass-specific ammonia production rate of 64.4â h-1 is achieved, which are all the best among studies reported at 100â mg L-1 of nitrate concentration to date.
ABSTRACT
We sought to measure serum salusin-α levels in patients with coronary artery disease (CAD) and to assess their correlation with the severity of the disease. We enrolled 172 patients with CAD and 91 controls. We assessed the angiographic severity of CAD by coronary atherosclerosis index (CAI) and detected serum salusin-α levels by enzyme-linked immunosorbent assay (ELISA). We demonstrated that CAD patients had significantly lower serum salusin-α levels compared to controls. Moreover, serum salusin-α levels were independently and negatively correlated with the presence and severity of CAD. These findings indicated that salusin-α might serve as a potential biomarker for predicting the development and progression of CAD.
Subject(s)
Coronary Artery Disease/blood , Intercellular Signaling Peptides and Proteins/blood , Aged , Biomarkers/blood , C-Reactive Protein/metabolism , Case-Control Studies , Coronary Angiography , Coronary Artery Disease/diagnostic imaging , Female , Humans , Male , Middle Aged , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Severity of Illness IndexABSTRACT
OBJECTIVE: To test 25# and 27# ultramicroporous expanded polytetrafluo-roethylene mitral valve (UPMV) under pulsatile flow condition in vitro. METHODS: Six 25# and six 27#UPMV were tested using TH-1200 HV Prosthesis Pulsatile Flow Tester in vitro at the cycling rate of 70 cycle/min, with the systolic pressure maintained at about 16 kPa (120 mmHg), diastolic pressure at 10.7 kPa (80 mmHg), and the percentage of mean forward flow at 35%. The stimulant cardiac output was maintained at 2, 3, 4, 5 and 6 L/min, respectively, for the testing. RESULTS: The mean pressure difference for the 25#UPMV under stimulant cardiac output of 2, 3, 4, 5 and 6 L/min was 2.488-/+0.378, 4.427-/+0.240, 5.460-/+0.449, 6.776-/+0.391 and 8.327-/+0.490 mmHg, and its effective valvular orifice was 1.430-/+0.333, 1.993-/+0.208, 2.260-/+0.477, 3.204-/+0.174 and 3.652-/+0.158 cm(2), respectively. The regurgitant fraction of the 25#UPMV under each stimulant cardiac output was (5.731-/+0.643) %, (5.431-/+0.312) %, (5.059-/+0.708) %, (3.545-/+0.097) % and (2.615-/+0.125) %, respectively. The mean pressure difference of the 27#UPMV under each stimulant cardiac output was 1.618-/+0.497, 3.448-/+0.440, 4.825-/+0.434, 5.494-/+0.446 and 7.482-/+0.455 mmHg, effective valvular orifice was 1.773-/+0.364, 2.113-/+0.305, 2.409-/+0.295, 3.326-/+0.417 and 4.522-/+0.445 cm(2), and regurgitant fraction was (5.357-/+0.509) %, (5.407-/+0.110) %, (4.999-/+0.182) %, (4.010-/+0.254) % and (2.584-/+0.114)%, respectively. CONCLUSION: The mean pressure difference, effective valvular orifice and regurgitant fraction of the UPMVs can measure up to the national criteria for artificial heart valve prosthesis of China.
Subject(s)
Heart-Assist Devices/standards , Mitral Valve , Polytetrafluoroethylene/chemistry , Pulsatile Flow , Biocompatible Materials/chemistry , Cardiac Output , Heart Valve Prosthesis/standards , Heart Valve Prosthesis Implantation/methods , Humans , Materials Testing/methods , PorosityABSTRACT
OBJECTIVE: To study the durability of expanded polytetrafluoroethylene artificial heart valve (ePTFE AHV). METHODS: Six ePTFE AHVs were tested for 400 million times against accelerated fatigue using TH-2200 artificial heart valve exosomatic accelerated fatigue instrument. Hydromechanical parameters of fore-and-aft accelerated fatigue test of the 6 AHVs were obtained by TH-1200 artificial heart valve exosomatic pulsatile stream instrument. RESULTS AND CONCLUSION: The mean gradient pressure spanning the valve and the effective orific area of ePTFE AHVs did not undergo significant changes after fore-and-aft the fatigue test, but the regurgitation volume and regurgitation rate of ePTFE AHVs were reduced after the accelerated fatigue test, suggesting good durability of ePTFE AHV.
Subject(s)
Biocompatible Materials/chemistry , Heart Valve Prosthesis/standards , Materials Testing/methods , Polytetrafluoroethylene/chemistry , Tensile StrengthABSTRACT
OBJECTIVE: To study in vivo calcification and biomechanics of the ultra-microporous expanded polytetrafluo- roethylene (UePTFE) in rabbits in comparison with glutaral-treated bovine pericardium (BP), so as to assess the potential of UePTFE as a material for cardiac valve prosthesis. METHODS: Factorial analysis was adopted in the experiment. UePTFE and glutaral-treated BP of appropriate sizes were embedded beneath skin of young New Zealand rabbits, and at 0, 1, 3 and 6 months following the implantation, the materials were measured for the content of calcium and biomechanics properties. RESULTS: Lower level of calcification of the UePTFE occurred after the implantation, as compared with BP, and the biomechanics indices of the former UePTFE were obviously suprior to those of the latter. CONCLUSION: UePTFE is a better material than BP for cardiac valve prosthesis.
Subject(s)
Bioprosthesis , Calcinosis/etiology , Heart Valve Prosthesis , Polytetrafluoroethylene , Animals , Biomechanical Phenomena , Cattle , Female , Male , RabbitsABSTRACT
OBJECTIVE: To review our experience in surgical treatment of ascending aortic aneurysm (AAA) with aortic insufficiency in 14 cases of by Bentall's procedure. METHODS AND RESULTS: All the patients underwent replacement of the ascending aorta and aortic valve with composite valved vascular prosthesis and received direct implantation of the aortic graft of the coronary orifices (Bentall's procedure) with satisfactory results. Five patients had ascending aortic dissection and 4 had typical Marfan's syndrome. All the patients suffered severe aortic insufficiency while 2 had mitral insufficiency. Coronary orifices were implanted in situ in 13 cases while in 1 case, Cabrol's method was adopted. No death occurred during the surgery and in the subsequent follow-up, and all the patients had good recovery. CONCLUSION: Bentall's procedure can be effective in the treatment of AAA with aortic insufficiency.