Effects of reflowing temperature and time on the alloy layer of tinplate and its electrochemical behavior in 3.5%NaCl solution were investigated by electrochemical measurements and surface characterization.It is found...Effects of reflowing temperature and time on the alloy layer of tinplate and its electrochemical behavior in 3.5%NaCl solution were investigated by electrochemical measurements and surface characterization.It is found that the amount of alloy layer increases with the increase of reflowing temperature and time.Then the corrosion potential of detinned tinplate shifts positively and the corrosion rate decreases.After being coupled with tin,the detinned tinplate acts as cathode and tin acts as anode initially.However,after being exposed for some time,the potential shifts of both detinned tinplate and tin reverse the polarity of the coupling system.The galvanic current density decreases with the increase of reflowing temperature and time.展开更多
Interactions between 63Sn37Pb solder and PBGA metallization (Au/Ni/Cu) duringlaser and infrared reflow soldering were studied. During laser reflow soldering process,a thin layer of AuSn_4 was observed at the interface...Interactions between 63Sn37Pb solder and PBGA metallization (Au/Ni/Cu) duringlaser and infrared reflow soldering were studied. During laser reflow soldering process,a thin layer of AuSn_4 was observed at the interface of the solder bumps, its morphologywas strongly dependent on the laser reflow power and heating time. The solder bumpsformed by the first laser reflow was reflowed again to form the solder joints. TheAuSn_4 compounds formed in the first laser reflow process dissolved into the bulk solderafter the secondary infrared reflow process. The needle-like AuSn_4 changed into rod-like, and distributed inside the solder near the solder/pad interface.展开更多
Objective To evaluate effects of preinfarction angina(PA) on no reflow phenomenon after percutaneous coronary intervention(PCI) in patients with acute myocardial infarction(AMI).Methods one hundred patients with first...Objective To evaluate effects of preinfarction angina(PA) on no reflow phenomenon after percutaneous coronary intervention(PCI) in patients with acute myocardial infarction(AMI).Methods one hundred patients with first AMI were divided into no reflow group( n =15)and reflow group( n =85). All patients undervent PCI within 12h after onset of AMI.No reflow phenomenon,defined as TIMI grade 2 flow or less without apparent residual stenosis .Myocardial enzyme was continuously measured;Left ventricular function was assessed by radionuclideimaging; The incidence of ventricular aneurysm and in hospital mortality was observed. Results (1)Patients with no reflow had a significantly lower incidence of PA( 20% vs 61% , P <0.01 ), a higher incidence of anterior infarction (67%vs35%, P <0.05 ), and had significantly higher peak creatine MB fraction than those with reflow(403±132vs277±151, P <0.01 ).(2) Patients with no reflow had significantly larger myocardial infarction area (MIA) ( 27.6 ±9.1% vs 20.9 ±9.4% , P <0.01 ), significantly higer left ventricular ejection fraction (46±8% vs 53±9%, P <0.01 ),and had a higher incidence of ventricular aneurysm and mortality than those with reflow (20%vs4%,p<0.05;20% vs 2%, P <0.05 ). (3)Multivariate Logistic analysis showed that the absence of preinfarction angina was a major independent determinant of no reflow( OR = 6.12 , P =0.01 ).Conclusions The absence of preinfarction angina is a high dangerous factor of no reflow phenomenon; No reflow phenomenon is associated with a high incidence of heart failure and mortality.展开更多
With the increase of surface assembly density and the rapid development of surface mount technology (SMT), electronic products tend to be miniaturized and integrated. The welding quality and welding technology of surf...With the increase of surface assembly density and the rapid development of surface mount technology (SMT), electronic products tend to be miniaturized and integrated. The welding quality and welding technology of surface mount components have attracted more and more attention. Reflow processing technology is a comprehensive scientific research. There are many reasons for the welding quality defects of each electronic component. Any material performance change or unreasonable processing parameters may lead to hidden welding quality defects. Therefore, in the specific production process, it is necessary to make in-depth analysis of practical problems and constantly improve the reflow soldering process, so as to improve the reflow soldering quality, ensure the up-to-standard rate of new products and improve the stability of electronic products and commodity quality.展开更多
Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Met...Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Methods Patients were placed in a DI group and control group.The DI group was given DI and the control group was given physiologic saline.The administration lasted 4 to 6 days in both groups after PCI.Cardiac magnetic resonance(CMR)was carried out during the perioperative period(7±2 days).The primary endpoint of the study was myocardial infarct size(IS)imaged on delayed-enhancement CMR.The secondary endpoint was major adverse cardiac events observed 6 months after PCI.Results In total,160 high-risk NR patients were enrolled,and 110 patients completed the CMR examination.According to postoperative CMR,the Myocardial Salvage Index and left ventricular ejection fraction were higher in the DI group(0.57±0.13 vs.0.48±0.17,P<0.01;49.3%±6.9%vs.46.2%±7.7%,P=0.03,respectively),whereas the IS was lower(19.7%±5.6%vs.22.2%±6.5%,P=0.04),compared with that in the control group.These differences were observed to be significant.After 6 months,the prevalence of major adverse cardiac events in the DI group decreased compared with that in the control group,but the differences were not observed to be significant(P>0.05).Conclusion The application of DI can reduce the myocardial infarct size in STEMI patients at a high risk of NR during primary PCI.展开更多
Loquat(Eriobotrya japonica Lindl.)is an evergreen fruit tree species of the Rosaceae,and its unique flowering time greatly hinders its production.To explore the artificial regulation of loquat flowering time,we remove...Loquat(Eriobotrya japonica Lindl.)is an evergreen fruit tree species of the Rosaceae,and its unique flowering time greatly hinders its production.To explore the artificial regulation of loquat flowering time,we removed the main inflorescence(by cutting it)to induce reflowering.For different loquat tree cultivars with different stages,the inflorescence was removed by cutting the main floral axis at two alternative positions:the upper or the lower position beneath the inflorescence,and it was found that the proportion of reflowering resulting from removing the upper position of the main floral axis of yellow-flesh loquat cultivars during the full-bloom stage was the highest.In addition,compared with those of the normal-growing panicles,the number of flower buds and branch axes of the reflowering panicles decreased significantly after cutting.Importantly,these newly produced inflorescences flowered 2–4 months later than normal-growing inflorescences did,effectively prolonging both the flowering and fruiting time.In addition,qRT-PCR results showed that EjFT1,EjFT2,EjAP1–1 and EjAP1–2 were highly expressed in the floral axis.These findings highlighted a new method for extending the production cycle of loquat and provided a reference for the flowering regulation of loquat and other economically important fruit tree species.展开更多
To investigate the effect of Au thickness on evolution of AuSnx IMCs, pads with 0. 1, 0. 5 and 4. 0 μm thickness of Au surface finish were utilized. Laser reflowed solder joints were aged in 125℃ isothermal ovens. R...To investigate the effect of Au thickness on evolution of AuSnx IMCs, pads with 0. 1, 0. 5 and 4. 0 μm thickness of Au surface finish were utilized. Laser reflowed solder joints were aged in 125℃ isothermal ovens. Results indicated that little IMC formed at the interface of solder and pad with 0. 1 μm thickness of Au. Even in condition of 744 hours aging, thickness of lMCs did not increase obviously. As for the joints with 0. 5 μm thickness of Au, most of AuSn4 IMCs stayed at the inteornce and were in needle-like or dendritic morphology. With the increase of aging time, AuSn4 IMCs beeame flat and changed to a continuous layer. In the joints with 4. 0 μm thickness of Au on pads, AuSn, AuSn2, AuSn4 IMCs and Au2Sn phase formed at the interface. As aging time was increased, more Sn rich IMCs formed at the interface, and evolved to AuSn4 IMCs in condition of long time aging. Thickness of AuSn4 IMCs reached about 30μm.展开更多
ead-free Sn3.5Ag and Sn3.5Ag0.5Cu solder balls were reflowed by laser to form solder bumps. Shear test was performed on the solder bumps, and SEM/EDX （scanning electron microscopy/energy dispersive X-ray spectrometer...ead-free Sn3.5Ag and Sn3.5Ag0.5Cu solder balls were reflowed by laser to form solder bumps. Shear test was performed on the solder bumps, and SEM/EDX （scanning electron microscopy/energy dispersive X-ray spectrometer） was used to analyze the formation of intermetallic compounds （IMCs） at interface region. A finite element modeling on the temperature gradient and distribution at the interface of solder bump during laser reflow process was conducted to elucidate the mechanism of the IMCs growth direction. The results show that the parameters window for laser reflow bumping of Sn3.5Ag0.5Cu was wider than that of Sn3.5Ag. The shear strength of Sn3.5Ag0.5Cu solder bump was comparable to that of Sn3.5Ag solder bump, and was not affected obviously by laser power and irradiation time when appropriate parameters were used. Both laser power and heating time had a significant effect on the formation of IMCs. A continuous AuSn4 intermetallic compound layer and some needle-like AuSn4 were observed at the interface of solder and Au/Ni/Cu metallization layer when the laser power is small. The formation of needle-like AuSn4 was due to temperature gradient at the interface, and the direction of temperature gradient was the preferred growth direction of AuSn4. With increasing the laser power and heating time, the needle-like AuSn4 IMCs dissolved into the bulk solder, and precipitated out once again during solidification along the grain boundary of the solder bump.展开更多
Background: Acute myocardial infarction is a leading cause of death worldwide nowadays and treatment of choice is primary percutaneous coronary intervention (PCI). No reflow is a complication that increases mortality ...Background: Acute myocardial infarction is a leading cause of death worldwide nowadays and treatment of choice is primary percutaneous coronary intervention (PCI). No reflow is a complication that increases mortality and morbidity post intervention and one of its predictors is platelet lymphocyte ratio. Aim of Study: To assess relation between admission platelet to lymphocyte ratio (PLR) and angiographic reflow after primary PCI in acute ST elevation myocardial infarction (STEMI). Patients and Methods: This is a prospective study that was conducted from May 2017 to May 2018 at Cardiology Department, Menoufia University Hospital. Sixty patients presented with ST-elevation myocardial infarction who were eligible for primary PCI were enrolled in the study. According to TIMI flow post intervention, patients were arranged into 2 groups: Group 1 (Normal Reflow) included thirty patients with post intervention TIMI flow III and Group 2 (NO Reflow) included thirty patients with post intervention TIMI flow (0, I, II). Comparison between both groups was done regarding platelet lymphocyte ratio (PLR). Result: PLR was significantly higher in patients with coronary no reflow than in patients with normal reflow with a P-value of , timing interval between onset of chest pain to time of intervention and thrombus grading was significantly higher in patients with no reflow than in patients with normal reflow. Conclusion: Pre-intervention PLR is an independent predictor of slow flow/no reflow following PPCI in patient with acute STEMI.展开更多
Adhering tin is the main reason of a reflow conductor roll which works in an electroplating tin line （ETL）. A det- inning agent whose main composition is NaOH and KOH and assistant composition is Na2PbO2 or K2PbO2 a...Adhering tin is the main reason of a reflow conductor roll which works in an electroplating tin line （ETL）. A det- inning agent whose main composition is NaOH and KOH and assistant composition is Na2PbO2 or K2PbO2 and NaNO3 or NaNO2 has excellent detinning effects when the temperature of detinning solution is 40-80℃ and the temperature of the reflow conductor roll reaches 40-70℃. After the adhering tin layer of the reflow conductor roll is removed, the roughness of the reflow conductor roll can resume to 4.0 μm, its service life increases by 80%, and the repairing cost decreases by 90%.展开更多
The surface roughness of reflow conductor roll was checked on membrane sample. The surface morphology of conductor roll was observed by microscope, and the composition of adhered layer on conductor roll surface was an...The surface roughness of reflow conductor roll was checked on membrane sample. The surface morphology of conductor roll was observed by microscope, and the composition of adhered layer on conductor roll surface was analyzed by X-ray spectroscope. The results show that tin adhesion is the main reason for failure of conductor roll, and the failure of conductor roll is accelerated by wear. The measures to decrease tin adhesion and improve wear resistance were put forward.展开更多
The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated thr...The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves （shear force vs displacement）. From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.展开更多
Laser and hot air reflow soldering of PBGA solder ball was investigated. Experimental results showed that surface quality and shear strength of solder bump reflowed by laser was superior than the solder bump by hot ai...Laser and hot air reflow soldering of PBGA solder ball was investigated. Experimental results showed that surface quality and shear strength of solder bump reflowed by laser was superior than the solder bump by hot air, and the microstructure within the solder bump reflowed by laser was much finer. Analysis on interfacial reaction showed that eutectic solder reacted with Au/Ni/Cu pad shortly after the solder was melted. Interface of solder bump reflowed by laser consists of a continuous AuSn 4 layer and remnant Au element. Needle like AuSn 4 grew sidewise from interface, and then spread out to the entire interface region. A thin layer of Ni 3Sn 4 intermetallic compound was found at the interface of solder bump reflowed by hot air, and AuSn 4 particles distributed within the whole solder bump randomly. The combination effect of the continuous AuSn 4 layer and finer eutectic microstructure contributes to the higher shear strength of solder bump reflowed by laser.展开更多
Introduction: No reflow during primary angioplasty is associated with a poor prognosis despite the reopening of the culprit coronary. The aim of our work was to determine the predictive factors of no reflow. Methodolo...Introduction: No reflow during primary angioplasty is associated with a poor prognosis despite the reopening of the culprit coronary. The aim of our work was to determine the predictive factors of no reflow. Methodology: Single-center retrospective analytical study from June 2000 to December 2016 that included patients presenting with STEMI took care of by primary angioplasty. No reflow was defined according to angiographic criteria: a TIMI flow Results: The prevalence of no reflow was 24%. In univariate analysis mean age, diabetes,hypertension, tachycardia, hypotension, killip stage 4 left ventricular failure, hyperglycemia > 11, renal failure, left ventricular dysfunction, tritruncal status, common trunk involvement, initial TIMI flow at 0, significant thrombotic load, delay to angioplasty > 6 hours, and predilation were all correlated with no reflow with a p 75 years [OR = 6.02, 95% CI 1.4 - 27, p = 0.014], tachycardia [OR = 4.3, 95% CI 1.6 - 7.4, p = 0.037], delay to angioplasty > 6 hours [OR = 1.3, 95% CI 1.1 - 2.1, p = 0.003] and high thrombotic load [OR = 1.5, 95% CI 1.3 - 3.2, p = 0.02] were independent predictors of no reflow. Conclusion: No reflow is associated with a poor short-term prognosis. Its care requires knowledge of predictive factors, prevention and treatment.展开更多
Coronary no-reflow phenomenon belongs to a type of coronary microcirculation disturbance,and its main pathogenic factors are vascular endothelial cell injury,microembolism and inflammatory reaction,which are correspon...Coronary no-reflow phenomenon belongs to a type of coronary microcirculation disturbance,and its main pathogenic factors are vascular endothelial cell injury,microembolism and inflammatory reaction,which are corresponding to the pathogenesis of choroid injury,blood stasis and heat toxin in traditional Chinese medicine,such as NO,ET-1,chemokine,IL and other cytokines.The degree of improvement of patients'symptoms and laboratory examination data provide a basis for traditional Chinese medicine compound prescription,monomer and traditional Chinese medicine characteristic therapy for the treatment of no-reflow phenomena(NRP).Combined with related factors,the author summarizes the research progress of traditional Chinese medicine treatment of NRP in recent years,in order to provide clinical reference.展开更多
Objective: To study the effect of intracoronary sodium nitroprusside and tirofiban injection on myocardial injury in patients with no reflow in PCI. Methods: Patients with acute coronary syndrome who underwent PCI and...Objective: To study the effect of intracoronary sodium nitroprusside and tirofiban injection on myocardial injury in patients with no reflow in PCI. Methods: Patients with acute coronary syndrome who underwent PCI and had no reflow in Gong'an County People's Hospital in Hubei Province between August 2014 and July 2017 were selected as the research subjects and randomly divided into two groups, combined group accepted intracoronary sodium nitroprusside and tirofiban injection during PCI, and control group accepted intracoronary tirofiban injection during PCI. The serum levels of myocardial injury indexes, oxidative stress indexes and inflammatory mediators of the two groups were measured before treatment and 1 d after treatment. Results: 1 d after treatment, serum CK-MB, H-FABP, sFas, cMyBP-C, MPO, MDA, Caspase-3, MCP-1, IL-1β, IL-18, MMP2 and MMP9 levels of both groups were significantly lower than those before treatment whereas SOD and NQO-1 levels were higher than those before treatment, and serum CK-MB, H-FABP, sFas, cMyBP-C, MPO, MDA, Caspase-3, MCP-1, IL-1β, IL-18, MMP2 and MMP9 levels of combined group were significantly lower than those of control group whereas SOD and NQO-1 levels were higher than those control group. Conclusion: Intracoronary sodium nitroprusside and tirofiban injection can reduce the myocardial injury in patients with no reflow in PCI.展开更多
Background The no-reflow phenomenon is correlated with adverse effects on short-term and long-term outcomes of ST-elevation myocardial infarction(STEMI) in patients undergoing primary percutaneous coronary interventio...Background The no-reflow phenomenon is correlated with adverse effects on short-term and long-term outcomes of ST-elevation myocardial infarction(STEMI) in patients undergoing primary percutaneous coronary intervention(PCI). The lymphocyte-to-monocyte ratio(LMR) is a novel inflammatory marker which is associated with slow coronary flow. We aimed to investigate the predictive value of LMR for no-reflow phenomenon in patients with STEMI undergoing primary PCI. Methods A total of 1350 STEMI patients were enrolled in this study from January 2014 to January 2018. Blood samples were obtained at initial admission for analysis of LMR.The univariate and multivariate logistic regression analysis was performed to study the relationship between LMR and no-reflow phenomenon. Results All the 156 patients among the study population suffered from no-reflow phenomenon during the procedure. The LMR level was significantly lower in patients with no-reflow(1.6 ±1.0 vs. 3.25 ± 1.8, P<0.001). Multivariate logistic regression analysis showed that LMR was independently associated with no-reflow post primary PCI in STEMI patients.(OR 2.356, 95% CI 1.201-5.945;P=0.030). The area under the ROC curve for the LMR was 0.757 [95% confidence interval(CI) 0.686-0.828, P<0.001]. Conclusions LMR at admission could serve as a biomarker for no-reflow phenomenon in patients undertaken primary PCI for STEMI.[S Chin J Cardiol 2019;20(4):228-235]展开更多
Background Percutaneous coronary intervention （PCI） is used as a treatment for acute myocardial infarction （AMI）, and one of its major complications is the angiographic no-reflow phenomenon （NR）. Although intra-...Background Percutaneous coronary intervention （PCI） is used as a treatment for acute myocardial infarction （AMI）, and one of its major complications is the angiographic no-reflow phenomenon （NR）. Although intra-aortic balloon pumping （IABP） is sometimes used in such patients to increase the diastolic coronary blood flow, there is little available information regarding the effects of IABP on the angiographic no-reflow phenomenon. Method Twenty-two AMI patient with NR were performed primary PCI between January 2006 and December 2009, of which 12 patients were selected for IABP therapy and the left 10 were selected as the control group by group procedure of odd and even days; We observed the vasoactive substance in both groups on the days of 1, 2, 3, 5, 7, 10 after the different interventions, which include plasma renin activity （PRA）, angiotensin Ⅱ （ANG Ⅱ）, aldosterone （ALD）, adrenaline （E）, and noradrenalin （NE）; In addition, cardiac structure and cardiac ventricle systolic function including left atrium medial diameter （LAMD）, left ventricular medial diameter （LVMD） Finally, left ventricular ejection fraction （LVEF） were evaluated after 10 days, 3 months and 6 months; statistics was taken to analysis. Results According to the time concentration curve, vasoactive substance of the IABP group decreased faster than that of the control group, and this difference had statistical significance （P 〈 0.01 ） ; In terms of LAMD, LVMD, and LVEF, echocardiography difference of the IABP and the control group in 10 days, 3 months, and 6 months also showed statistical significance （P 〈 0.05）. Conclusions IABP can significantly reduce the release of vasoactive substances of NR in patients of primary PCI for AMI; LAMD, LVMD and LVEF in 10 days, 3 months, and 6 months can be improved using this method, which is conducive to recovery of heart function.展开更多
Background To investigate the effect of intra-aortic balloon pumping （IABP） on no-reflow phenomenon primary percutaneous coronary intervention （PCI） for ST-Elevation Myocardial Infarction （STEMI）. Methods Clinic...Background To investigate the effect of intra-aortic balloon pumping （IABP） on no-reflow phenomenon primary percutaneous coronary intervention （PCI） for ST-Elevation Myocardial Infarction （STEMI）. Methods Clinical data of 22 acute myocardial infarction patients after PCI with angiographic no-reflow phenomenon were retrospectively analyzed between January 2006 and December 2009.12 patients underwent IABP, other 10 patients as control group. We observed difference of cardiac structure, brain natriuretic peptide （BNP） and ventricular systolic function between two group, as well as cardiac injury markers （MYO,CK-MB, cTnI） in both groups on the days of 1, 2, 3, 5, 7, 10 after the different interventions. In addition, cardiac structure and ventricular systolic function including left atrium medial diameter （LAMD）, left ventricular medial diameter （LVMD）, left ventricular ejection fraction （LVEF） was evaluated after 10 days, 3 months,6 months Finally, statistics was used to analysis the data. Results The several vasoactive substances as well as cardiac injury markers and LAMD, LVMD, LVEF of 10 days, 3 months, 6 months of IABP group were significant difference with control group significant difference （P 〉 0.0 PCI with angiographic no-reflo （P 〈 0.05）. 5）. Conclusions w phenomenon, BNP targets of IABP group compared with the control group no IABP has effects on prognosis in STEMI patients who performed which is conducive to recovery of heart function.展开更多
基金Projects (50771092,21073162) supported by the National Natural Science Foundation of China
文摘Effects of reflowing temperature and time on the alloy layer of tinplate and its electrochemical behavior in 3.5%NaCl solution were investigated by electrochemical measurements and surface characterization.It is found that the amount of alloy layer increases with the increase of reflowing temperature and time.Then the corrosion potential of detinned tinplate shifts positively and the corrosion rate decreases.After being coupled with tin,the detinned tinplate acts as cathode and tin acts as anode initially.However,after being exposed for some time,the potential shifts of both detinned tinplate and tin reverse the polarity of the coupling system.The galvanic current density decreases with the increase of reflowing temperature and time.
文摘Interactions between 63Sn37Pb solder and PBGA metallization (Au/Ni/Cu) duringlaser and infrared reflow soldering were studied. During laser reflow soldering process,a thin layer of AuSn_4 was observed at the interface of the solder bumps, its morphologywas strongly dependent on the laser reflow power and heating time. The solder bumpsformed by the first laser reflow was reflowed again to form the solder joints. TheAuSn_4 compounds formed in the first laser reflow process dissolved into the bulk solderafter the secondary infrared reflow process. The needle-like AuSn_4 changed into rod-like, and distributed inside the solder near the solder/pad interface.
文摘Objective To evaluate effects of preinfarction angina(PA) on no reflow phenomenon after percutaneous coronary intervention(PCI) in patients with acute myocardial infarction(AMI).Methods one hundred patients with first AMI were divided into no reflow group( n =15)and reflow group( n =85). All patients undervent PCI within 12h after onset of AMI.No reflow phenomenon,defined as TIMI grade 2 flow or less without apparent residual stenosis .Myocardial enzyme was continuously measured;Left ventricular function was assessed by radionuclideimaging; The incidence of ventricular aneurysm and in hospital mortality was observed. Results (1)Patients with no reflow had a significantly lower incidence of PA( 20% vs 61% , P <0.01 ), a higher incidence of anterior infarction (67%vs35%, P <0.05 ), and had significantly higher peak creatine MB fraction than those with reflow(403±132vs277±151, P <0.01 ).(2) Patients with no reflow had significantly larger myocardial infarction area (MIA) ( 27.6 ±9.1% vs 20.9 ±9.4% , P <0.01 ), significantly higer left ventricular ejection fraction (46±8% vs 53±9%, P <0.01 ),and had a higher incidence of ventricular aneurysm and mortality than those with reflow (20%vs4%,p<0.05;20% vs 2%, P <0.05 ). (3)Multivariate Logistic analysis showed that the absence of preinfarction angina was a major independent determinant of no reflow( OR = 6.12 , P =0.01 ).Conclusions The absence of preinfarction angina is a high dangerous factor of no reflow phenomenon; No reflow phenomenon is associated with a high incidence of heart failure and mortality.
文摘With the increase of surface assembly density and the rapid development of surface mount technology (SMT), electronic products tend to be miniaturized and integrated. The welding quality and welding technology of surface mount components have attracted more and more attention. Reflow processing technology is a comprehensive scientific research. There are many reasons for the welding quality defects of each electronic component. Any material performance change or unreasonable processing parameters may lead to hidden welding quality defects. Therefore, in the specific production process, it is necessary to make in-depth analysis of practical problems and constantly improve the reflow soldering process, so as to improve the reflow soldering quality, ensure the up-to-standard rate of new products and improve the stability of electronic products and commodity quality.
基金supported by grant from the Capital health research and development of special project (2016-15011)
文摘Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Methods Patients were placed in a DI group and control group.The DI group was given DI and the control group was given physiologic saline.The administration lasted 4 to 6 days in both groups after PCI.Cardiac magnetic resonance(CMR)was carried out during the perioperative period(7±2 days).The primary endpoint of the study was myocardial infarct size(IS)imaged on delayed-enhancement CMR.The secondary endpoint was major adverse cardiac events observed 6 months after PCI.Results In total,160 high-risk NR patients were enrolled,and 110 patients completed the CMR examination.According to postoperative CMR,the Myocardial Salvage Index and left ventricular ejection fraction were higher in the DI group(0.57±0.13 vs.0.48±0.17,P<0.01;49.3%±6.9%vs.46.2%±7.7%,P=0.03,respectively),whereas the IS was lower(19.7%±5.6%vs.22.2%±6.5%,P=0.04),compared with that in the control group.These differences were observed to be significant.After 6 months,the prevalence of major adverse cardiac events in the DI group decreased compared with that in the control group,but the differences were not observed to be significant(P>0.05).Conclusion The application of DI can reduce the myocardial infarct size in STEMI patients at a high risk of NR during primary PCI.
基金supported by Shaoguan City Science and Technology Planning Project(Social Development Direction-Supporting Scientific Research Workers Project)(Grant No.200811094530739)the Key Realm R&D Program of Guang Dong Provide(Grant No.2018B020202011)+2 种基金Open Fund of Key laboratory of Loquat Germplasm Innovation and Utilization(Putian University)Fujian Province University(Grant No.2019005)Guangdong Province College Students’Innovative and Entrepreneurial Training Program(Grant No.S202010576014X)。
文摘Loquat(Eriobotrya japonica Lindl.)is an evergreen fruit tree species of the Rosaceae,and its unique flowering time greatly hinders its production.To explore the artificial regulation of loquat flowering time,we removed the main inflorescence(by cutting it)to induce reflowering.For different loquat tree cultivars with different stages,the inflorescence was removed by cutting the main floral axis at two alternative positions:the upper or the lower position beneath the inflorescence,and it was found that the proportion of reflowering resulting from removing the upper position of the main floral axis of yellow-flesh loquat cultivars during the full-bloom stage was the highest.In addition,compared with those of the normal-growing panicles,the number of flower buds and branch axes of the reflowering panicles decreased significantly after cutting.Importantly,these newly produced inflorescences flowered 2–4 months later than normal-growing inflorescences did,effectively prolonging both the flowering and fruiting time.In addition,qRT-PCR results showed that EjFT1,EjFT2,EjAP1–1 and EjAP1–2 were highly expressed in the floral axis.These findings highlighted a new method for extending the production cycle of loquat and provided a reference for the flowering regulation of loquat and other economically important fruit tree species.
基金Acknowledgement This work is finaneially supported by the National Natural Science Foundation of China （Grant No. 51005058）, National Hight- eeh R＆D Program （863 Program ） of China （Grant No. 2007AA04Z314） and Natural Scientific Research Innovation Foundation in Harbin Institute of Technology （ HIT. NSRIF. 2009037 ）.
文摘To investigate the effect of Au thickness on evolution of AuSnx IMCs, pads with 0. 1, 0. 5 and 4. 0 μm thickness of Au surface finish were utilized. Laser reflowed solder joints were aged in 125℃ isothermal ovens. Results indicated that little IMC formed at the interface of solder and pad with 0. 1 μm thickness of Au. Even in condition of 744 hours aging, thickness of lMCs did not increase obviously. As for the joints with 0. 5 μm thickness of Au, most of AuSn4 IMCs stayed at the inteornce and were in needle-like or dendritic morphology. With the increase of aging time, AuSn4 IMCs beeame flat and changed to a continuous layer. In the joints with 4. 0 μm thickness of Au on pads, AuSn, AuSn2, AuSn4 IMCs and Au2Sn phase formed at the interface. As aging time was increased, more Sn rich IMCs formed at the interface, and evolved to AuSn4 IMCs in condition of long time aging. Thickness of AuSn4 IMCs reached about 30μm.
基金supported by the National Natural Science Foundation of China under grant No.50475031/E052104.
文摘ead-free Sn3.5Ag and Sn3.5Ag0.5Cu solder balls were reflowed by laser to form solder bumps. Shear test was performed on the solder bumps, and SEM/EDX （scanning electron microscopy/energy dispersive X-ray spectrometer） was used to analyze the formation of intermetallic compounds （IMCs） at interface region. A finite element modeling on the temperature gradient and distribution at the interface of solder bump during laser reflow process was conducted to elucidate the mechanism of the IMCs growth direction. The results show that the parameters window for laser reflow bumping of Sn3.5Ag0.5Cu was wider than that of Sn3.5Ag. The shear strength of Sn3.5Ag0.5Cu solder bump was comparable to that of Sn3.5Ag solder bump, and was not affected obviously by laser power and irradiation time when appropriate parameters were used. Both laser power and heating time had a significant effect on the formation of IMCs. A continuous AuSn4 intermetallic compound layer and some needle-like AuSn4 were observed at the interface of solder and Au/Ni/Cu metallization layer when the laser power is small. The formation of needle-like AuSn4 was due to temperature gradient at the interface, and the direction of temperature gradient was the preferred growth direction of AuSn4. With increasing the laser power and heating time, the needle-like AuSn4 IMCs dissolved into the bulk solder, and precipitated out once again during solidification along the grain boundary of the solder bump.
文摘Background: Acute myocardial infarction is a leading cause of death worldwide nowadays and treatment of choice is primary percutaneous coronary intervention (PCI). No reflow is a complication that increases mortality and morbidity post intervention and one of its predictors is platelet lymphocyte ratio. Aim of Study: To assess relation between admission platelet to lymphocyte ratio (PLR) and angiographic reflow after primary PCI in acute ST elevation myocardial infarction (STEMI). Patients and Methods: This is a prospective study that was conducted from May 2017 to May 2018 at Cardiology Department, Menoufia University Hospital. Sixty patients presented with ST-elevation myocardial infarction who were eligible for primary PCI were enrolled in the study. According to TIMI flow post intervention, patients were arranged into 2 groups: Group 1 (Normal Reflow) included thirty patients with post intervention TIMI flow III and Group 2 (NO Reflow) included thirty patients with post intervention TIMI flow (0, I, II). Comparison between both groups was done regarding platelet lymphocyte ratio (PLR). Result: PLR was significantly higher in patients with coronary no reflow than in patients with normal reflow with a P-value of , timing interval between onset of chest pain to time of intervention and thrombus grading was significantly higher in patients with no reflow than in patients with normal reflow. Conclusion: Pre-intervention PLR is an independent predictor of slow flow/no reflow following PPCI in patient with acute STEMI.
基金[This research was financially supported by Baoshan Iron & Steel Co., Ltd. (No. KOZDSAE400).]
文摘Adhering tin is the main reason of a reflow conductor roll which works in an electroplating tin line （ETL）. A det- inning agent whose main composition is NaOH and KOH and assistant composition is Na2PbO2 or K2PbO2 and NaNO3 or NaNO2 has excellent detinning effects when the temperature of detinning solution is 40-80℃ and the temperature of the reflow conductor roll reaches 40-70℃. After the adhering tin layer of the reflow conductor roll is removed, the roughness of the reflow conductor roll can resume to 4.0 μm, its service life increases by 80%, and the repairing cost decreases by 90%.
文摘The surface roughness of reflow conductor roll was checked on membrane sample. The surface morphology of conductor roll was observed by microscope, and the composition of adhered layer on conductor roll surface was analyzed by X-ray spectroscope. The results show that tin adhesion is the main reason for failure of conductor roll, and the failure of conductor roll is accelerated by wear. The measures to decrease tin adhesion and improve wear resistance were put forward.
文摘The shear failure modes and respective failure mechanism of Sn3.5Ag and Sn3.0Ag0.5Cu lead-free solder bumping on Au/Ni/Cu metallization formed by induction spontaneous heating reflow process have been investigated through the shear test after aging at 120℃ for 0, 1, 4, 9 and 16 d. Different typical shear failure behaviors have been found in the loading curves （shear force vs displacement）. From the results of interracial morphology analysis of the fracture surfaces and cross-sections, two main typical failure modes have been identified. The probabilities of the failure modes occurrence are inconsistent when the joints were aged for different times. The evolution of the brittle NiaSn4 and Cu-Ni-Au-Sn layers and the grains coarsening of the solder bulk are the basic reasons for the change of shear failure modes.
文摘Laser and hot air reflow soldering of PBGA solder ball was investigated. Experimental results showed that surface quality and shear strength of solder bump reflowed by laser was superior than the solder bump by hot air, and the microstructure within the solder bump reflowed by laser was much finer. Analysis on interfacial reaction showed that eutectic solder reacted with Au/Ni/Cu pad shortly after the solder was melted. Interface of solder bump reflowed by laser consists of a continuous AuSn 4 layer and remnant Au element. Needle like AuSn 4 grew sidewise from interface, and then spread out to the entire interface region. A thin layer of Ni 3Sn 4 intermetallic compound was found at the interface of solder bump reflowed by hot air, and AuSn 4 particles distributed within the whole solder bump randomly. The combination effect of the continuous AuSn 4 layer and finer eutectic microstructure contributes to the higher shear strength of solder bump reflowed by laser.
文摘Introduction: No reflow during primary angioplasty is associated with a poor prognosis despite the reopening of the culprit coronary. The aim of our work was to determine the predictive factors of no reflow. Methodology: Single-center retrospective analytical study from June 2000 to December 2016 that included patients presenting with STEMI took care of by primary angioplasty. No reflow was defined according to angiographic criteria: a TIMI flow Results: The prevalence of no reflow was 24%. In univariate analysis mean age, diabetes,hypertension, tachycardia, hypotension, killip stage 4 left ventricular failure, hyperglycemia > 11, renal failure, left ventricular dysfunction, tritruncal status, common trunk involvement, initial TIMI flow at 0, significant thrombotic load, delay to angioplasty > 6 hours, and predilation were all correlated with no reflow with a p 75 years [OR = 6.02, 95% CI 1.4 - 27, p = 0.014], tachycardia [OR = 4.3, 95% CI 1.6 - 7.4, p = 0.037], delay to angioplasty > 6 hours [OR = 1.3, 95% CI 1.1 - 2.1, p = 0.003] and high thrombotic load [OR = 1.5, 95% CI 1.3 - 3.2, p = 0.02] were independent predictors of no reflow. Conclusion: No reflow is associated with a poor short-term prognosis. Its care requires knowledge of predictive factors, prevention and treatment.
基金Shandong traditional Chinese Medicine Science and Technology Development Plan Project(No.2015-075)Shandong traditional Chinese Medicine Science and Technology Development Plan Project(No.2019-0191)+1 种基金Shandong Natural Science Foundation Project(No.ZR2019MH032)Shandong Natural Science Foundation Youth Project(No.ZR2020QH333)。
文摘Coronary no-reflow phenomenon belongs to a type of coronary microcirculation disturbance,and its main pathogenic factors are vascular endothelial cell injury,microembolism and inflammatory reaction,which are corresponding to the pathogenesis of choroid injury,blood stasis and heat toxin in traditional Chinese medicine,such as NO,ET-1,chemokine,IL and other cytokines.The degree of improvement of patients'symptoms and laboratory examination data provide a basis for traditional Chinese medicine compound prescription,monomer and traditional Chinese medicine characteristic therapy for the treatment of no-reflow phenomena(NRP).Combined with related factors,the author summarizes the research progress of traditional Chinese medicine treatment of NRP in recent years,in order to provide clinical reference.
文摘Objective: To study the effect of intracoronary sodium nitroprusside and tirofiban injection on myocardial injury in patients with no reflow in PCI. Methods: Patients with acute coronary syndrome who underwent PCI and had no reflow in Gong'an County People's Hospital in Hubei Province between August 2014 and July 2017 were selected as the research subjects and randomly divided into two groups, combined group accepted intracoronary sodium nitroprusside and tirofiban injection during PCI, and control group accepted intracoronary tirofiban injection during PCI. The serum levels of myocardial injury indexes, oxidative stress indexes and inflammatory mediators of the two groups were measured before treatment and 1 d after treatment. Results: 1 d after treatment, serum CK-MB, H-FABP, sFas, cMyBP-C, MPO, MDA, Caspase-3, MCP-1, IL-1β, IL-18, MMP2 and MMP9 levels of both groups were significantly lower than those before treatment whereas SOD and NQO-1 levels were higher than those before treatment, and serum CK-MB, H-FABP, sFas, cMyBP-C, MPO, MDA, Caspase-3, MCP-1, IL-1β, IL-18, MMP2 and MMP9 levels of combined group were significantly lower than those of control group whereas SOD and NQO-1 levels were higher than those control group. Conclusion: Intracoronary sodium nitroprusside and tirofiban injection can reduce the myocardial injury in patients with no reflow in PCI.
文摘Background The no-reflow phenomenon is correlated with adverse effects on short-term and long-term outcomes of ST-elevation myocardial infarction(STEMI) in patients undergoing primary percutaneous coronary intervention(PCI). The lymphocyte-to-monocyte ratio(LMR) is a novel inflammatory marker which is associated with slow coronary flow. We aimed to investigate the predictive value of LMR for no-reflow phenomenon in patients with STEMI undergoing primary PCI. Methods A total of 1350 STEMI patients were enrolled in this study from January 2014 to January 2018. Blood samples were obtained at initial admission for analysis of LMR.The univariate and multivariate logistic regression analysis was performed to study the relationship between LMR and no-reflow phenomenon. Results All the 156 patients among the study population suffered from no-reflow phenomenon during the procedure. The LMR level was significantly lower in patients with no-reflow(1.6 ±1.0 vs. 3.25 ± 1.8, P<0.001). Multivariate logistic regression analysis showed that LMR was independently associated with no-reflow post primary PCI in STEMI patients.(OR 2.356, 95% CI 1.201-5.945;P=0.030). The area under the ROC curve for the LMR was 0.757 [95% confidence interval(CI) 0.686-0.828, P<0.001]. Conclusions LMR at admission could serve as a biomarker for no-reflow phenomenon in patients undertaken primary PCI for STEMI.[S Chin J Cardiol 2019;20(4):228-235]
文摘Background Percutaneous coronary intervention （PCI） is used as a treatment for acute myocardial infarction （AMI）, and one of its major complications is the angiographic no-reflow phenomenon （NR）. Although intra-aortic balloon pumping （IABP） is sometimes used in such patients to increase the diastolic coronary blood flow, there is little available information regarding the effects of IABP on the angiographic no-reflow phenomenon. Method Twenty-two AMI patient with NR were performed primary PCI between January 2006 and December 2009, of which 12 patients were selected for IABP therapy and the left 10 were selected as the control group by group procedure of odd and even days; We observed the vasoactive substance in both groups on the days of 1, 2, 3, 5, 7, 10 after the different interventions, which include plasma renin activity （PRA）, angiotensin Ⅱ （ANG Ⅱ）, aldosterone （ALD）, adrenaline （E）, and noradrenalin （NE）; In addition, cardiac structure and cardiac ventricle systolic function including left atrium medial diameter （LAMD）, left ventricular medial diameter （LVMD） Finally, left ventricular ejection fraction （LVEF） were evaluated after 10 days, 3 months and 6 months; statistics was taken to analysis. Results According to the time concentration curve, vasoactive substance of the IABP group decreased faster than that of the control group, and this difference had statistical significance （P 〈 0.01 ） ; In terms of LAMD, LVMD, and LVEF, echocardiography difference of the IABP and the control group in 10 days, 3 months, and 6 months also showed statistical significance （P 〈 0.05）. Conclusions IABP can significantly reduce the release of vasoactive substances of NR in patients of primary PCI for AMI; LAMD, LVMD and LVEF in 10 days, 3 months, and 6 months can be improved using this method, which is conducive to recovery of heart function.
文摘Background To investigate the effect of intra-aortic balloon pumping （IABP） on no-reflow phenomenon primary percutaneous coronary intervention （PCI） for ST-Elevation Myocardial Infarction （STEMI）. Methods Clinical data of 22 acute myocardial infarction patients after PCI with angiographic no-reflow phenomenon were retrospectively analyzed between January 2006 and December 2009.12 patients underwent IABP, other 10 patients as control group. We observed difference of cardiac structure, brain natriuretic peptide （BNP） and ventricular systolic function between two group, as well as cardiac injury markers （MYO,CK-MB, cTnI） in both groups on the days of 1, 2, 3, 5, 7, 10 after the different interventions. In addition, cardiac structure and ventricular systolic function including left atrium medial diameter （LAMD）, left ventricular medial diameter （LVMD）, left ventricular ejection fraction （LVEF） was evaluated after 10 days, 3 months,6 months Finally, statistics was used to analysis the data. Results The several vasoactive substances as well as cardiac injury markers and LAMD, LVMD, LVEF of 10 days, 3 months, 6 months of IABP group were significant difference with control group significant difference （P 〉 0.0 PCI with angiographic no-reflo （P 〈 0.05）. 5）. Conclusions w phenomenon, BNP targets of IABP group compared with the control group no IABP has effects on prognosis in STEMI patients who performed which is conducive to recovery of heart function.
基金Acknowledgements： The work is supported by National Natural Science Foundation of China （No. 50675047） and Samsung Semiconductor （China） R ＆ D Co., Ltd. The authors would like to thank Professor LI Ming-yu in Shenzhen Graduate School, Harbin Institute of Technology, and Dr. DING Ying, in Microjoining Lab, Schoo） of Materials Science and Engineering, Harbin Institute of Technology for their comments.
