Self-Formation of a Ru/ZnO Multifunctional Bilayer for the Next-Generation Interconnect Technology via Area-Selective Atomic Layer Deposition.

This study suggests a Ru/ZnO bilayer grown using area-selective atomic layer deposition (AS-ALD) as a multifunctional layer for advanced Cu metallization. As a diffusion barrier and glue layer, ZnO is selectively grown on SiO2 , excluding Cu, where Ru, as a liner and seed layer, is grown on both surfaces. Dodecanethiol (DDT) is used as an inhibitor for the AS-ALD of ZnO using diethylzinc and H2 O at 120 °C. H2 plasma treatment removes the DDT adsorbed on Cu, forming inhibitor-free surfaces. The ALD-Ru film is then successfully deposited at 220 °C using tricarbonyl(trimethylenemethane)ruthenium and O2 . The Cu/bilayer/Si structural and electrical properties are investigated to determine the diffusion barrier performance of the bilayer film. Copper silicide is not formed without the conductivity degradation of the Cu/bilayer/Si structure, even after annealing at 700 °C. The effect of ZnO on the Ru/SiO2 structure interfacial adhesion energy is investigated using a double-cantilever-beam test and is found to increase with ZnO between Ru and SiO2 . Consequently, the Ru/ZnO bilayer can be a multifunctional layer for advanced Cu interconnects. Additionally, the formation of a bottomless barrier by eliminating ZnO on the via bottom, or Cu, is expected to decrease the via resistance for the ever-shrinking Cu lines.

Diabetes-Induced Jagged1 Overexpression in Endothelial Cells Causes Retinal Capillary Regression in a Murine Model of Diabetes Mellitus: Insights Into Diabetic Retinopathy.

BACKGROUND: Several mechanisms have been proposed to account for diabetes-induced microvasculopathy (DMV). Although Notch signaling was reported to be affected by glucose metabolism in endothelial cells during developmental angiogenesis, it has not been investigated in vascular remodeling of adult capillaries in relation to diabetes mellitus. METHODS: We induced diabetes mellitus in 8-week-old adult mice by intravenously administering streptozotocin. After 6 weeks, we harvested organs, including retina, heart, and skeletal muscle, and evaluated the capillaries with immunofluorescence and confocal microscopy. We modulated endothelial Notch signaling using chemical inhibitors in wild-type mice or transgenic mice, inducing conditional knockout of Jagged1 or Mib1. RESULTS: DMV was characterized by capillary remodeling, regression, and decreased density. Notch ligand Jagged1, but not δ-like ligand 4, was markedly increased in endothelial cells of diabetic mice. Using endothelium-specific Jagged1 knockdown mice, we found that blocking Jagged1 prevented DMV even under diabetic conditions. Furthermore, in the inducible endothelium-specific Jagged1 knockdown mice, blocking Jagged1 even at 4 weeks after the establishment of DMV could reverse it, leading to normalization of retinal vasculature. A search for downstream signals revealed that diabetes mellitus decreased the nuclear localization of Notch1 intracellular domain and reduced the expression of VE-cadherin and N-cadherin in endothelial cells. Chemical Notch inhibition phenocopied DMV in normal mice. CONCLUSIONS: Our findings indicate that diabetes mellitus induces Jagged1 overexpression and suppresses Notch signaling in endothelial cells, leading to DMV in adult mice. We conclude that dysregulated intercellular Notch signaling may be a novel mechanism of DMV.

Feasibility study of transfer function model on electrocardiogram change caused by acupuncture.

BACKGROUND: Acupuncture treatments that regulate the heart are used to treat various clinical disorders and conditions. Although many studies have been conducted to measure quantitatively the effects of acupuncture, thus far, models that describe these effects have not been established. The purpose of this study was to derive a transfer function model of acupuncture stimulation within the electrocardiograms based on the periods before, during, and after acupuncture. METHODS: Fourteen healthy subjects were included in this clinical trial. Five-minute electrocardiograms were captured before, during, and after acupuncture at HT7. For each period, signal-averaged electrocardiograms were created from all of the subjects' 5-min electrocardiograms for that period. Individual transfer functions, which has the highest average goodness of fit, were derived for each period pair. By averaging individual transfer functions, generalized transfer functions were derived. RESULTS: The transfer function with the highest average goodness of fit was a fraction with 4th order numerator and 5th order denominator. Fourteen individual transfer functions were derived separately for each pair of periods: before and during acupuncture, during and after acupuncture, and before and after acupuncture. Three generalized transfer functions were derived by averaging individual transfer functions for each period pair. CONCLUSION: The three generalized transfer functions that were derived may reflect the electrocardiogram changes caused by acupuncture. However, this clinical trial included only 14 subjects. Further studies with control groups and more subjects are needed. This clinical trial has been registered on the Clinical Research Information Service, Republic of Korea (No. KCT0001944). The first enrolment of subject started at 2 June 2015 and this trial was retrospectively registered at 14 June 2016.

Interaction between platelets and endothelial progenitor cells via LPA-Edg-2 axis is augmented by PPAR-δ activation.

BACKGROUND: Peroxisome proliferator-activated receptor (PPAR)-δ is a nuclear receptor regulating cell metabolism. The role of PPAR-δ in late endothelial progenitor cells (EPCs) has not been fully elucidated. We aim to understand the effects of PPAR-δ activation on late EPC and to reveal the underlying mechanism. METHODS AND RESULTS: Treatment with a highly selective PPAR-δ agonist (GW501516) induced proliferation of late EPCs and enhanced their vasculogenic potential. Search for the target molecule of PPAR-δ activation revealed endothelial differentiation gene (Edg)-2. Chromatin immunoprecipitation and promoter assays demonstrated that Edg-2 gene was specifically induced by PPAR-δ through direct transcriptional activation. Lysophosphatidic acid (LPA), an Edg ligand, mimicked the pro-vasculogenic effects of GW501516 in late EPCs whereas Edg antagonist (Ki16425) blocked these effects. Edg-2 is a membrane receptor for LPA which is a major growth factor from activated platelets. Thus, the interaction between platelets and late EPCs via the LPA-Edg-2 axis was assessed. Platelet supernatant boosted the pro-vasculogenic effects of GW501516, which was reversed by antagonist to PPAR-δ (GSK0660) or Edg (Ki16425). Both of in vivo Matrigel plug model and mouse skin punch-wound model demonstrated that the combination of platelets and PPAR-δ-activated late EPCs synergistically enhanced vascular regeneration. CONCLUSIONS: There exists a synergistic interaction between human platelets and late EPCs leading to vascular regeneration. This interaction consists of LPA from platelets and its receptor Edg-2 on the surface of EPCs and can be potentiated by PPAR-δ activation in EPCs. A PPAR-δ agonist is a good candidate to achieve vasculogenesis for ischemic vascular disease.

Vascular calcifying progenitor cells possess bidirectional differentiation potentials.

Vascular calcification is an advanced feature of atherosclerosis for which no effective therapy is available. To investigate the modulation or reversal of calcification, we identified calcifying progenitor cells and investigated their calcifying/decalcifying potentials. Cells from the aortas of mice were sorted into four groups using Sca-1 and PDGFRα markers. Sca-1(+) (Sca-1(+)/PDGFRα(+) and Sca-1(+)/PDGFRα(-)) progenitor cells exhibited greater osteoblastic differentiation potentials than Sca-1(-) (Sca-1(-)/PDGFRα(+) and Sca-1(-)/PDGFRα(-)) progenitor cells. Among Sca-1(+) progenitor populations, Sca-1(+)/PDGFRα(-) cells possessed bidirectional differentiation potentials towards both osteoblastic and osteoclastic lineages, whereas Sca-1(+)/PDGFRα(+) cells differentiated into an osteoblastic lineage unidirectionally. When treated with a peroxisome proliferator activated receptor γ (PPARγ) agonist, Sca-1(+)/PDGFRα(-) cells preferentially differentiated into osteoclast-like cells. Sca-1(+) progenitor cells in the artery originated from the bone marrow (BM) and could be clonally expanded. Vessel-resident BM-derived Sca-1(+) calcifying progenitor cells displayed nonhematopoietic, mesenchymal characteristics. To evaluate the modulation of in vivo calcification, we established models of ectopic and atherosclerotic calcification. Computed tomography indicated that Sca-1(+) progenitor cells increased the volume and calcium scores of ectopic calcification. However, Sca-1(+)/PDGFRα(-) cells treated with a PPARγ agonist decreased bone formation 2-fold compared with untreated cells. Systemic infusion of Sca-1(+)/PDGFRα(-) cells into Apoe(-/-) mice increased the severity of calcified atherosclerotic plaques. However, Sca-1(+)/PDGFRα(-) cells in which PPARγ was activated displayed markedly decreased plaque severity. Immunofluorescent staining indicated that Sca-1(+)/PDGFRα(-) cells mainly expressed osteocalcin; however, activation of PPARγ triggered receptor activator for nuclear factor-κB (RANK) expression, indicating their bidirectional fate in vivo. These findings suggest that a subtype of BM-derived and vessel-resident progenitor cells offer a therapeutic target for the prevention of vascular calcification and that PPARγ activation may be an option to reverse calcification.

Reliability and validity of tongue color analysis in the prediction of symptom patterns in terms of East Asian Medicine.

OBJECTIVE: To examine whether color parameters of tongue inspection (TI) using a digital camera was reliable and valid, and to examine which color parameters serve as predictors of symptom patterns in terms of East Asian medicine (EAM). METHODS: Two hundred female subjects' tongue substances were photographed by a mega-pixel digital camera. Together with the photographs, the subjects were asked to complete Yin deficiency, Phlegm pattern, and Cold-Heat pattern questionnaires. Using three sets of digital imaging software, each digital image was exposure- and white balance-corrected, and finally L* (luminance), a* (red-green balance), and b* (yellow-blue balance) values of the tongues were calculated. To examine intra- and inter-rater reliabilities and criterion validity of the color analysis method, three raters were asked to calculate color parameters for 20 digital image samples. Finally, four hierarchical regression models were formed. RESULTS: Color parameters showed good or excellent reliability (0.627-0.887 for intra-class correlation coefficients) and significant criterion validity (0.523-0.718 for Spearman's correlation). In the hierarchical regression models, age was a significant predictor of Yin deficiency (ß = 0.192), and b* value of the tip of the tongue was a determinant predictor of Yin deficiency, Phlegm, and Heat patterns (ß = - 0.212, - 0.172, and - 0.163). Luminance (L*) was predictive of Yin deficiency (ß = -0.172) and Cold (ß = 0.173) pattern. CONCLUSION: Our results suggest that color analysis of the tongue using the L*a*b* system is reliable and valid, and that color parameters partially serve as symptom pattern predictors in EAM practice.

Direct conversion of adult skin fibroblasts to endothelial cells by defined factors.

BACKGROUND: Cell-based therapies to augment endothelial cells (ECs) hold great therapeutic promise. Here, we report a novel approach to generate functional ECs directly from adult fibroblasts. METHODS AND RESULTS: Eleven candidate genes that are key regulators of endothelial development were selected. Green fluorescent protein (GFP)-negative skin fibroblasts were prepared from Tie2-GFP mice and infected with lentiviruses allowing simultaneous overexpression of all 11 factors. Tie2-GFP(+) cells (0.9%), representing Tie2 gene activation, were detected by flow cytometry. Serial stepwise screening revealed 5 key factors (Foxo1, Er71, Klf2, Tal1, and Lmo2) that were required for efficient reprogramming of skin fibroblasts into Tie2-GFP(+) cells (4%). This reprogramming strategy did not involve pluripotency induction because neither Oct4 nor Nanog was expressed after 5 key factor transduction. Tie2-GFP(+) cells were isolated using fluorescence-activated cell sorting and designated as induced ECs (iECs). iECs exhibited endothelium-like cobblestone morphology and expressed EC molecular markers. iECs possessed endothelial functions such as Bandeiraea simplicifolia-1 lectin binding, acetylated low-density lipoprotein uptake, capillary formation on Matrigel, and nitric oxide production. The epigenetic profile of iECs was similar to that of authentic ECs because the promoters of VE-cadherin and Tie2 genes were demethylated. mRNA profiling showed clustering of iECs with authentic ECs and highly enriched endothelial genes in iECs. In a murine model of hind-limb ischemia, iEC implantation increased capillary density and enhanced limb perfusion, demonstrating the in vivo viability and functionality of iECs. CONCLUSIONS: We demonstrated the first direct conversion of adult fibroblasts to functional ECs. These results suggest a novel therapeutic modality for cell therapy in ischemic vascular disease.

Human podoplanin-positive monocytes and platelets enhance lymphangiogenesis through the activation of the podoplanin/CLEC-2 axis.

Emerging studies suggested that murine podoplanin-positive monocytes (PPMs) are involved in lymphangiogenesis. The goal of this study was to demonstrate the therapeutic lymphangiogenesis of human PPMs by the interaction with platelets. Aggregation culture of human peripheral blood mononuclear cells (PBMCs) resulted in cellular aggregates termed hematospheres. During 5-day culture, PPMs expanded exponentially and expressed several lymphatic endothelial cell-specific markers including vascular endothelial growth factor receptor (VEGFR)-3 and well-established lymphangiogenic transcription factors. Next, we investigated the potential interaction of PPMs with platelets that had C-type lectin-like receptor-2 (CLEC-2), a receptor of podoplanin. In vitro coculture of PPMs and platelets stimulated PPMs to strongly express lymphatic endothelial markers and upregulate lymphangiogenic cytokines. Recombinant human CLEC-2 also stimulated PPMs through Akt and Erk signaling. Likewise, platelets in coculture with PPMs augmented secretion of a lymphangiogenic cytokine, interleukin (IL)-1-ß, via podoplanin/CLEC-2 axis. The supernatant obtained from coculture was able to enhance the migration, viability, and proliferation of lymphatic endothelial cell. Local injection of hematospheres with platelets significantly increased lymphatic neovascularization and facilitated wound healing in the full-thickness skin wounds of nude mice. Cotreatment with PPMs and platelets augments lymphangiogenesis through podoplanin/CLEC-2 axis, which thus would be a promising novel strategy of cell therapy to treat human lymphatic vessel disease.

Individual characteristics of reliable lumbar coupling motions.

INTRODUCTION: Coupling motions (CMs) are the motions occurring in different directions around the primary motion. As low back pain (LBP) is known to be associated with lumbar CMs, some studies measured lumbar CMs using the microelectromechanical system inertial measurement unit (MEMS-IMU) because of its low cost and small size. This study aimed to examine the reliability of lumbar CM measurements using the MEMS-IMU and to classify the individual characteristics of lumbar CMs. METHODS: MEMS-IMUs were attached to the two lumbar points (L1, L5) of 19 male volunteers (age, 24.3 ± 1.2 years). Following an instructional video and audio recording, they conducted the six lumbar movements three times: flexion and extension, left and right lateral bending, and left and right rotation. The six lumbar movements were repeated after 1 h. Raw data were transformed into angle data using MATLAB. Intraclass correlation coefficients (ICCs) were calculated to evaluate intratest repeatability and test-retest reliability. Finally, angle data were analyzed to examine whether individual characteristics of lumbar CMs could be identified. RESULTS: Lumbar CM measurements showed fair to good or excellent intratest repeatability and test-retest reliability, ranging from 0.669 to 0.997 of the ICCs. All lumbar CMs could be categorized into six types, and flexion and extension CMs were more prominent than other CMs. CONCLUSIONS: Lumbar CM measurements obtained using the MEMS-IMU are reliable, and identifying the individual variations of lumbar CMs may be helpful for alleviating chronic or recurrent LBP.

Biodegradable-polymer drug-eluting stents vs. bare metal stents vs. durable-polymer drug-eluting stents: a systematic review and Bayesian approach network meta-analysis.

BACKGROUND: The aim of this study was to compare the safety and efficacy of biodegradable-polymer (BP) drug-eluting stents (DES), bare metal stents (BMS), and durable-polymer DES in patients undergoing coronary revascularization, we performed a systematic review and network meta-analysis using a Bayesian framework. METHODS AND RESULTS: Study stents included BMS, paclitaxel-eluting (PES), sirolimus-eluting (SES), endeavor zotarolimus-eluting (ZES-E), cobalt-chromium everolimus-eluting (CoCr-EES), platinium-chromium everolimus-eluting (PtCr-EES), resolute zotarolimus-eluting (ZES-R), and BP biolimus-eluting stents (BP-BES). After a systematic electronic search, 113 trials with 90 584 patients were selected. The principal endpoint was definite or probable stent thrombosis (ST) defined according to the Academic Research Consortium within 1 year. RESULTS: Biodegradable polymer-biolimus-eluting stents [OR, 0.56; 95% credible interval (CrI), 0.33-0.90], SES (OR, 0.53; 95% CrI, 0.38-0.73), CoCr-EES (OR, 0.34; 95% CrI, 0.23-0.52), and PtCr-EES (OR, 0.31; 95% CrI, 0.10-0.90) were all superior to BMS in terms of definite or probable ST within 1 year. Cobalt-chromium everolimus-eluting stents demonstrated the lowest risk of ST of all stents at all times after stent implantation. Biodegradable polymer-biolimus-eluting stents was associated with a higher risk of definite or probable ST than CoCr-EES (OR, 1.72; 95% CrI, 1.04-2.98). All DES reduced the need for repeat revascularization, and all but PES reduced the risk of myocardial infarction compared with BMS. CONCLUSIONS: All DESs but PES and ZES-E were superior to BMS in terms of ST within 1 year. Cobalt-chromium everolimus-eluting stents was safer than any DES even including BP-BES. Our results suggest that not only the biodegradability of polymer, but the optimal combination of stent alloy, design, strut thickness, polymer, and drug all combined determine the safety of DES.

Physical properties and biocompatibility of an injectable calcium-silicate-based root canal sealer: in vitro and in vivo study.

BACKGROUND: The aim of this study was to investigate the physical properties and biological effects of an experimentally developed injectable premixed calcium-silicate root canal sealer (Endoseal) in comparison with mineral trioxide aggregate (MTA) and a resin-based sealer (AHplus). METHODS: The pH, solubility, dimensional change, flow, and radiopacity of the materials were evaluated. Biocompatibility was evaluated on the basis of cell morphology and a viability test using MC3T3-E1 cells. For evaluate inflammatory reaction, the tested sealers were implanted into dorsal subcutaneous connective tissue of Sprague Dawley rats. After 7 days, the implants with the surrounding tissue were retrieved, and histological evaluation was performed. RESULTS: Endoseal showed high alkalinity similar to that of MTA. The solubility of the tested materials was similar. The dimensional change and flow of Endoseal was significantly higher than that of other materials (P < 0.05). The radiopacity of Endoseal was lower than that of AHplus (P < 0.05). The biocompatibility was similar to those of MTA. Inflammatory reaction of Endoseal was similar with that of MTA, but lower than that of AHplus (P < 0.05). CONCLUSIONS: The present study indicates that Endoseal has favorable physical properties and biocompatibility. Therefore, we suggest that Endoseal has the potential to be used as a predictable root canal sealer.

High glucose-induced jagged 1 in endothelial cells disturbs notch signaling for angiogenesis: a novel mechanism of diabetic vasculopathy.

Angiogenesis is a multistep process which is orchestrated by intercellular signaling. We developed an in vitro model of human angiogenesis to identify a pathologic angiogenesis and intercellular signaling in high glucose condition. We co-cultivated human endothelial cells (ECs) and smooth muscle cells (SMCs) in a spheroid on an SMC monolayer for 7 days either in high glucose or in control condition. We analyzed vascular growth and expression of notch or its ligands with confocal microscopy. Abnormal angiogenesis by high glucose condition was characterized by (1) increased sprouting and branching (high glucose vs. normal: number of sprouts 20.3±1.5 vs. 13.7±2.9, p=0.024; number of branching points 7.6±2.5 vs. 2.3±2.1, p=0.047), (2) decreased vascular diameter (diameter of the tubes 13.4±6. 1µm vs. 19.1±8.8 µm, p=0.012) and (3) destabilization of the tubes. We identified that high glucose induced jagged 1 and suppressed notch1 in ECs whereas it did not affect Dll4. Constitutive jagged 1 overexpression or inhibition of notch1 in ECs induced abnormal angiogenesis as the high glucose condition did. Endothelial-specific shRNA targeting jagged 1 rescued the aberrant angiogenesis in high glucose condition. High glucose condition induced an abnormal endothelial intercellular signaling leading to aberrant angiogenesis. It is a novel mechanism of diabetic microvasculopathy which can be a therapeutic target beyond glucose control.

The impact of residual coronary lesions on clinical outcomes after percutaneous coronary intervention: Residual SYNTAX score after percutaneous coronary intervention in patients from the Efficacy of Xience/Promus versus Cypher in rEducing Late Loss after stENTing (EXCELLENT) registry.

BACKGROUND: The SYNTAX score (SS) is used in preprocedural evaluation for percutaneous coronary intervention (PCI); it assesses the complexity of coronary lesions and predicts PCI outcome. However, the usefulness of the residual SS (rSS), which can be calculated after PCI and may reflect the completeness of revascularization, has not been fully investigated in an enriched PCI population. METHODS AND RESULTS: The baseline SS and rSS were determined in 5,088 patients (3,046 everolimus-eluting stents and 2,042 sirolimus-eluting stents) from the EXCELLENT registry. The primary end point was 1-year patient-oriented composite end point (POCE), comprising all-cause death, myocardial infarction, and repeat revascularization. The mean baseline SS was 13.6 ± 9.1 and rSS was 4.7 ± 6.5. Residual SS tertiles were defined as rSS = 0 (42.7%), 0 < rSS < 7 (29.9%), and rSS ≥ 7 (27.4%). Increasing rSS tertiles had increasing 1-year POCE rates (5.2%, 8.1%, 12.4%; P < .001) mainly caused by the increase in repeat revascularization. Also, rSS was an independent predictor of 1-year POCE after multivariate analysis (P for trend < .001) and had better predictability in simple coronary lesions (baseline SS < 16). The clinical rSS, calculated by multiplying the rSS to a modified age, creatinine clearance, and ejection fraction score (age/ejection fraction + 1 for each 10 mL the creatinine clearance <60 mL/min), was also associated with 1-year POCE, with predictability similar to rSS (area under curve 0.610 vs 0.607, P = .634). CONCLUSION: Greater residual coronary lesions after PCI with "limus" drug-eluting stent, as quantified by the rSS and the clinical rSS, are associated with increased risk of adverse cardiac events.

Peroxisome proliferator-activated receptor-δ activates endothelial progenitor cells to induce angio-myogenesis through matrix metallo-proteinase-9-mediated insulin-like growth factor-1 paracrine networks.

AIMS: The roles of peroxisome proliferator-activated receptor (PPAR)-δ in vascular biology are mainly unknown. We investigated the effects of PPAR-δ activation on the paracrine networks between endothelial progenitor cells (EPCs) and endothelial cells (ECs)/skeletal muscle. METHODS AND RESULTS: Treatment of EPCs with GW501516, a PPAR-δ agonist, induced specifically matrix metallo-proteinase (MMP)-9 by direct transcriptional activation. Subsequently, this increased-MMP-9 broke down insulin-like growth factor-binding protein (IGFBP)-3, resulting in IGF-1 receptor (IGF-1R) activation in surrounding target cells. Treatment of conditioned medium from GW501516-stimulated EPCs enhanced the number and functions of human umbilical vein ECs and C2C12 myoblasts via MMP-9-mediated IGF-1R activation. Systemic administration of GW501516 in mice increased MMP-9 expression in EPCs, and augmented IGFBP-3 degradation in serum. In a mouse hindlimb ischaemia model, systemic treatment of GW501516 or local transplantation of GW501516-treated EPCs induced IGF-1R phosphorylation in ECs and skeletal muscle in the ischaemic limbs, leading to augmented angiogenesis and skeletal muscle regeneration. It also enhanced wound healing with increased angiogenesis in a mouse skin punch wound model. These pro-angiogenic and muscle-regenerating effects were abolished by MMP-9 knock-out. CONCLUSION: Our results suggest that PPAR-δ is a crucial modulator of angio-myogenesis via the paracrine effects of EPCs, and its agonist is a good candidate as a therapeutic drug for patients with peripheral vascular diseases.

Brittle Fracture Behavior of Sn-Ag-Cu Solder Joints with Ni-Less Surface Finish via Laser-Assisted Bonding.

In this study, we investigated the brittle fracture behavior of Sn-3.0Ag-0.5Cu (SAC305) solder joints with a Direct Electroless Gold (DEG) surface finish, formed using laser-assisted bonding (LAB) and mass reflow (MR) techniques. Commercial SAC305 solder balls were used to ensure consistency. LAB increases void fractions and coarsens the primary ß-Sn phase with higher laser power, resulting in a larger eutectic network area fraction. In contrast, MR produces solder joints with minimal voids and a thicker intermetallic compound (IMC) layer. LAB-formed joints exhibit higher high-speed shear strength and lower brittle fracture rates compared to MR. The key factor in the reduced brittle fracture in LAB joints is the thinner IMC layer at the joint interface. This study highlights the potential of LAB in enhancing the mechanical reliability of solder joints in advanced electronic packaging applications.

Safety and efficacy of everolimus- versus sirolimus-eluting stents: a systematic review and meta-analysis of 11 randomized trials.

BACKGROUND: While EES have proven superior to paclitaxel-eluting stents, it remains uncertain whether EES improve clinical outcomes compared to SES, which are the most efficacious among the first-generation drug-eluting stents. We performed a meta-analysis of randomized trials comparing the efficacy and safety of everolimus-eluting stents (EES) versus sirolimus-eluting stents (SES) in patients undergoing percutaneous coronary intervention. METHODS: From online and offline search until December 2011, we identified 11 randomized trials (total 12,869 patients). The primary endpoint was major adverse cardiac events. RESULTS: The risk of major adverse cardiac events did not differ significantly between the patients treated with EES versus SES [OR, 0.90 (95% CI, 0.77-1.04); P = .162]. However, we found a significant reduction in the risk of repeat revascularization in the EES arm [OR, 0.85 (95% CI, 0.71-1.00); P = .047]. There were no significant differences regarding the risk of cardiac death [OR, 0.97 (95% CI, 0.74-1.27); P = .834], or myocardial infarction [OR, 0.95 (95% CI, 0.75-1.20), P = .656]. The risk of definite or probable stent thrombosis tended to be lower [OR, 0.68 (95% CI, 0.45-1.02); P = .065], while definite ST was significantly lower [OR, 0.44 (95% CI, 0.25-0.80); P = .007] with EES. CONCLUSIONS: In a large systematic overview of comparative trials involving percutaneous revascularization with drug-eluting stents, treatment with EES significantly reduced the risk of repeat revascularization and definite ST compared to SES. We found no significant differences in the risk of cardiac death or myocardial infarction.

COMP-Ang1 stimulates HIF-1α-mediated SDF-1 overexpression and recovers ischemic injury through BM-derived progenitor cell recruitment.

Recruitment and adhesion of bone marrow (BM)-derived circulating progenitor cells to ischemic tissue are important for vasculogenesis and tissue repair. Recently, we found cartilage oligomeric matrix protein (COMP)-Ang1 is a useful cell-priming agent to improve the therapeutic efficacy of progenitor cells. However, the effect and the underlying mechanisms of COMP-Ang1 on recruitment of BM-derived progenitor cells (BMPCs) to foci of vascular injury have not been well defined. Here, we found that COMP-Ang1 is a critical stimulator of stromal cell-derived factor 1 (SDF-1), the principal regulator of BM-cell trafficking. Furthermore, SDF-1 stimulation by COMP-Ang1 was blocked by small-interfering RNA (siRNA) against hypoxia-inducible factor-1α (HIF-1α). COMP-Ang1 increased the synthesis of HIF-1α by activating mammalian target of rapamycin (mTOR) in hypoxic endothelium. The intermediate mechanism transmitting the COMP-Ang1 signal to the downstream mTOR/HIF-1α/SDF-1 pathway was the enhanced binding of the Tie2 receptor with integrin-linked kinase (ILK), an upstream activator of mTOR. In the mouse ischemic model, local injection of COMP-Ang1 stimulated the incorporation of BMPCs into ischemic limb, thereby enhancing neovasculogenesis and limb salvage. Collectively, our findings identify the COMP-Ang1/HIF-1α/SDF-1 pathway as a novel inducer of BMPC recruitment and neovasculogenesis in ischemic disease.

CYP3A4 genetic status may be associated with increased vulnerability to the inhibitory effect of calcium-channel blockers on clopidogrel.

BACKGROUND: Calcium-channel blockers (CCBs) inhibit the CYP3A4 enzyme, which is involved in clopidogrel activation. Studies have shown conflicting results regarding the effect of concomitant CCB administration on clopidogrel response. We investigated the relationship between CYP3A4 genotype and the inhibitory effect of CCBs on clopidogrel response. METHODS AND RESULTS: Clopidogrel on-treatment platelet reactivity (OPR) was measured and CYP3A4 (IVS10+12G>A) genotyped in 1,247 consecutive patients with drug-eluting stent implantation. The mean OPR was 231±83 (P2Y12 reaction units: PRU). In total, 332 (26.6%) CCB users had higher OPR compared with 915 (73.4%) non-CCB users (245±84 vs. 227±83 PRU, P=0.001). The distribution of CYP3A4 (IVS10+12G>A) genotype was 63.6%, 32.6% and 3.8% for GG, GA and AA genotypes, respectively. After adjustment for possible confounding factors, the number of A-alleles was associated with increased vulnerability to CCB use (effect of CCB use ΔPRU: +8 PRU, P=0.210, +24 PRU, P=0.012, +50 PRU, P=0.025, for patients with 0, 1, and 2 A-alleles, respectively, +24 PRU, P=0.005 for GA/AA genotypes). Furthermore, only in the GA/AA-genotype did CCB use result in a significantly increased risk for high-OPR (odds ratio 1.84, 95% confidence interval 1.15-2.92, P=0.010). CONCLUSIONS: CCB use is associated with increased OPR. The number of CYP3A4 (IVS10+12G>A) A-alleles may be associated with an increased vulnerability to the effects of CCBs on clopidogrel response variation.

Usefulness of the SYNTAX and clinical SYNTAX scores in predicting clinical outcome after unrestricted use of sirolimus- and everolimus-eluting Stents.

BACKGROUND: The SYNTAX score (SS) and clinical SS (cSS) can assess coronary lesion complexity and are useful indices in predicting outcomes after percutaneous coronary intervention. However, their validity has not been fully investigated in daily practice where "limus"-eluting stents are used. METHODS AND RESULTS: The SS and cSS were independently assessed from the Efficacy of Xience/Promus vs. Cypher in rEducing Late Loss after stENTing (EXCELLENT) registry, together with the 1-year patient-oriented composite endpoint (POCE; all-cause death, any myocardial infarction (MI), and any revascularization) and target-lesion failure (TLF; cardiac death, target-vessel MI, and target-lesion revascularization). Among 5,102 patients, tertiles for SS were defined as low-SS <8, 8≤mid-SS≤16, high-SS >16. Both POCE (4.2% vs. 7.7% vs. 12.2%, P<0.001) and TLF (1.6% vs. 2.4% vs. 4.5%, P<0.001) increased significantly with increasing SS tertile, and SS was an independent predictor of POCE (P<0.001 for trend) and TLF (P=0.023 for trend) in multivariate analysis. The predictability of SS and cSS was similar for POCE (area under the curve (AUC): 0.635 vs. 0.629, P=0.599), whereas SS was superior in predicting restenosis-related outcomes such as revascularization (AUC: 0.624 vs. 0.577, P<0.001) and cSS was superior in other components such as death (AUC: 0.654 vs. 0.795, P<0.001). CONCLUSIONS: Both SS and cSS were applicable to unrestricted use of "limus"-eluting stents in predicting the risk of 1-year clinical outcomes.

Secondary sphere formation enhances the functionality of cardiac progenitor cells.

Loss of cardiomyocytes impairs cardiac function after myocardial infarction (MI). Recent studies suggest that cardiac stem/progenitor cells could repair the damaged heart. However, cardiac progenitor cells are difficult to maintain in terms of purity and multipotency when propagated in two-dimensional culture systems. Here, we investigated a new strategy that enhances potency and enriches progenitor cells. We applied the repeated sphere formation strategy (cardiac explant → primary cardiosphere (CS) formation → sphere-derived cells (SDCs) in adherent culture condition → secondary CS formation by three-dimensional culture). Cells in secondary CS showed higher differentiation potentials than SDCs. When transplanted into the infarcted myocardium, secondary CSs engrafted robustly, improved left ventricular (LV) dysfunction, and reduced infarct sizes more than SDCs did. In addition to the cardiovascular differentiation of transplanted secondary CSs, robust vascular endothelial growth factor (VEGF) synthesis and secretion enhanced neovascularization in the infarcted myocardium. Microarray pathway analysis and blocking experiments using E-selectin knock-out hearts, specific chemicals, and small interfering RNAs (siRNAs) for each pathway revealed that E-selectin was indispensable to sphere initiation and ERK/Sp1/VEGF autoparacrine loop was responsible for sphere maturation. These results provide a simple strategy for enhancing cellular potency for cardiac repair. Furthermore, this strategy may be implemented to other types of stem/progenitor cell-based therapy.