Stabilizing resistive random access memory by constructing an oxygen reservoir with analyzed state distribution.

In this paper, the instability mechanism of resistive random access memory (RRAM) was investigated, and a technique was developed to stabilize the distribution of high resistance states (HRS) and better concentrate the set voltage. Due to the accumulation of oxygen, an interface-type switching characteristic was observed on the I-V curves beneath the filament-type switching behavior. In this work, the interface-type switching characteristic is used to fit the natural distribution of HRS as an analysis of the instability mechanism. According to the results, the HRS distribution is attributed to the accumulation of excess oxygen ions left from the lower oxygen content and oxygen vacancy recombination during the reset process. The proposed solution with simple plasma treatment, can create an excess oxygen reservoir by changing the surface topography of the electrode to store the surplus oxygen ions from the reset process, eliminating the oxygen accumulation effect and further improving the device stability.

Risk factors for infective endocarditis in children with congenital heart diseases - A nationwide population-based case control study.

BACKGROUND: Infective endocarditis (IE) is uncommon in childhood. Its associated epidemiological characteristics in patients with congenital heart disease (CHD) remain unclear. METHODS: The study population included children born in Taiwan during the years 1997 to 2005 who were diagnosed as having CHD before 3years of age. All children were followed up until the end year of 2010, the diagnosis of infective endocarditis, or death. The demographic characteristics of patients with and without IE, the invasive procedures performed during 6months before the index date, the prophylactic antibiotics related to dental procedures, and in-hospital mortality were collected. RESULTS: Information of 24,729 children with CHD were retrieved for our analysis and 237 patients with newly diagnosed IE were identified. The incidence rate of IE in all CHD lesions was 11.13 per 10,000person-years. Taking ASD for reference, the following CHD lesions were at risk for IE: cyanotic CHD (adjusted OR, 9.58; 95% confidence interval, 5.38-17.05), endocardial cushion defect (ECD) (8.01; 2.73-23.50), Left-sided lesions (4.36; 1.90-10.01) and VSD (2.93; 1.64-5.23). Patients who underwent procedures have a higher risk of acquiring IE which include central venous catheter (CVC) insertion (3.17; 2.36-4.27), cardiac catheterization (3.74; 2.67-5.22), open-heart surgery (2.47; 1.61-3.77), valve surgery (3.20; 1.70-6.02), and shunt surgery (7.43; 2.36-23.41). However, dental procedures did not increase the risk of IE, irrespective of antibiotic usage. CONCLUSIONS: The risk of IE varies markedly among CHD lesions in our study. Invasive heart procedures but not dental procedures, are more significantly associated with IE among children with CHD.

Risk factors and derived formosa score for intravenous immunoglobulin unresponsiveness in Taiwanese children with Kawasaki disease.

BACKGROUND/PURPOSE: Kawasaki disease (KD) is the most common pediatric vasculitis. The study aimed to identify the risk factors of intravenous immunoglobulin (IVIG) unresponsiveness from the initial clinical parameters of the Taiwanese KD patients. METHODS: We enrolled 248 KD (development dataset: 181, validation: 67) patients who received IVIG within 10 days after fever onset. IVIG unresponsiveness was defined by persistent fever beyond 24 hours after IVIG or recrudescent fever with KD symptoms. RESULTS: From the development dataset (181 patients), IVIG unresponsiveness was noted in 22 patients (12.1%). The preIVIG levels of albumin, percentage of neutrophils, and positive lymphadenopathy were identified with highest risk for IVIG unresponsiveness. These three variables were used to construct a three-variable logistic regression model, which yielded an area under the receiver-operating-characteristics curve of 0.87. These three variables were further used to generate a composite scoring model (Formosa score) which yielded a sensitivity of 90.9% and specificity of 81.3% for a cut-off point of three or more. Validation in an independent cohort (67 KD patients) yielded sensitivity and specificity of 71.4% and 81.0%, respectively. CONCLUSION: We have established a simple three-variable Formosa score for KD patients to identify early those at risk of IVIG unresponsiveness for timely aggressive immunomodulation initially.

Acute and late coronary outcomes in 1073 patients with Kawasaki disease with and without intravenous γ-immunoglobulin therapy.

OBJECTIVE: To explore acute and late coronary outcomes and their risk/modifiers in patients with Kawasaki disease (KD). DESIGN: Retrospective study. SETTING AND PATIENTS: 1073 patients with KD identified from a tertiary care medical centre (1980-2012; 8677 patient-years). MAIN OUTCOME MEASURES: The acute coronary severities and late outcomes (survival free of coronary aneurysm persistence and ischaemia) were assessed. RESULTS: Coronary arterial lesions occurred in 40.6% of cases at their acute febrile stages, and persisted beyond 1 month in 196 (18.3%, M/F=138/58) patients: 125 (11.6%) had small aneurysms, 44 (4.1%) had medium aneurysms, and 27 (2.5%) had giant aneurysms. At follow-up (1-46 years), coronary aneurysms persisted in all with giant aneurysms, in 55% of those with medium aneurysms (18% with stenosis), and in 9% of those with small aneurysms. Ischaemia events occurred in 14 patients (M/F=13/1) and caused four deaths. Among the patients with KD with coronary aneurysms, 10-year ischaemia event-free and aneurysm persistence probability was 87.5% and 20.6%, respectively. The only independent risk for aneurysm persistence was the aneurysm severity 1 month after KD onset (χ(2)=80.73, p<10(-3)). Male patients and intravenous γ-immunoglobulin (IVIG) therapy were independent risk factors of initial coronary severity but were not associated with the late coronary outcomes, even in severity stratified subgroups. CONCLUSIONS: The coronary severity 1 month after KD onset is most crucial to the late coronary outcomes. Although IVIG use improves the initial severity of coronary lesions, it does not further modify the long-term fate of coronary aneurysms.

Coronary Diameters in Taiwanese Children Younger than 6 Years Old: Z-Score Regression Equations Derived from Body Surface Area.

BACKGROUND: The measurements of coronary diameters, usually obtained by 2-dimentsional echocardiography, play important roles oin the management and follow-up of Kawasaki disease (KD). However, in Taiwan, domestic normgrams and a Z-score calculator for coronary artery diameters are still not available. METHODS: Echocardiography was performed on 412 healthy children younger than 6 years of age. The appropriate exponential regression model was fitted to correspond with body surface area (BSA). The computed Z-scores of all subjects were also tested for normal distribution. RESULTS: Using the model ln (measurement) = ß1 + ß2 × ln (BSA), the adjusted R(2) values were 0.611 and 0.484 for the models of the left main coronary artery (LMCA) and the right (RCA), respectively. Analysis of computed Z-score distribution showed acceptable goodness of fit for a normal distribution [p = 0.90 (LMCA); p = 0.17 (RCA)]. CONCLUSIONS: We have established reference ranges for the coronary artery diameters in Taiwanese children younger than 6 years of age. The regression equations and Z-score calculators for the LMCA and RCA provide an objective determination of coronary dilatation in a large population, which is important for the care and medical management of KD patients in Taiwan. KEY WORDS: Coronary diameter; Kawasaki disease; Taiwan; Z-score.

Clinical Implication of the C Allele of the ITPKC Gene SNP rs28493229 in Kawasaki Disease: Association With Disease Susceptibility and BCG Scar Reactivation.

BACKGROUND: a functional single nucleotide polymorphism (SNP) (rs28493229) in the inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) gene has been linked to the susceptibility to Kawasaki disease (KD). The implication remains unclear. SUBJECTS AND METHODS: genotyping for the ITPKC polymorphism was conducted on 280 unrelated Taiwanese children with KD and 492 healthy ethnically and gender-matched controls. The clinical manifestations and laboratory data were systemically collected. RESULTS: the GC and CC genotypes of ITPKC gene SNP rs28493229 were overrepresented in KD patients (GG:GC:CC was 236:43:1, C allele frequency: 8.04%) than those in the controls (GG:GC:CC was 454:37:1, C allele frequency: 3.96%; OR: 2.23, P = 0.001). In KD patients, those with GC or CC genotypes of SNP rs28493229 (19/44) were more likely to have reactivation at the Bacille Calmette-Guérin (BCG) inoculation site than those with GG genotypes (66/236; OR: 1.96, P = 0.044). Such association was particularly strong in patients aged <20 months (OR: 3.26, P = 0.017). The other clinical manifestations were not related to this SNP. There were 160 (57.1%) patients with coronary arterial lesions. The development and the severity of coronary arterial lesion were also not associated with this SNP. Comparison between patients with and without BCG reactivation revealed only one difference: patients with reactivation were younger. CONCLUSION: in a cohort from a population with the world's third highest incidence of KD, we demonstrated that the C-allele of ITPKC SNP rs28493229 is associated with KD susceptibility and BCG scar reactivation during the acute phase, although its frequency is lower than that in the Japanese cohort (22.6%), suggesting this SNP contributes to KD susceptibility through induced hyperimmune function reflected in the BCG reactivation.

Abnormal matrix remodeling in adolescents and young adults with Kawasaki disease late after onset.

BACKGROUND: Patients with a history of Kawasaki disease (KD), have been found to have pericoronary and myocardial fibrosis. Serum biomarkers of fibrosis may be sensitive indices for detection of these late cardiac complications in KD patients. METHODS: We studied a cohort of 60 adolescents and young adults comprising 10 KD patients with persistent coronary artery lesions (CAL) occurring at a mean (SD) time of 14.5 (4.4) years after disease onset, 25 KD patients with no CAL after disease onset, and 25 healthy age-matched volunteers. We compared laboratory data from the patients and volunteers, including lipid profile, liver function, amino-terminal propeptide of type III procollagen (PIIINP), matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1), and MMP-9:TIMP-1 ratios. Severity of CAL was determined on the basis of computed tomography determinations of the frequency of aneurysms and the extent of coronary stenosis/occlusion, thrombosis, and calcification. RESULTS: Increased PIIINP and decreased MMP-9 and TIMP-1 concentrations and decreased MMP-9:TIMP-1 ratios were found not only in KD patients with persistent CAL but also in KD patients without CAL, although to a lesser extent in the latter group. In KD patients, the concentrations of PIIINP were positively associated with the severity of coronary stenosis/occlusion (r = 0.72, P = 0.011) and with the extent of coronary thrombus (r = 0.64, P = 0.014). The concentrations of high-sensitivity C-reactive protein, however, did not differ across groups. CONCLUSIONS: Our results demonstrate alterations in extracellular matrix biomarkers in KD patients, suggesting enhanced collagen synthesis and ameliorated degradation in adolescents and young adults late after the onset of KD. We also observed an association between the concentrations of PIIINP and the extent of coronary stenosis/occlusion or thrombosis in KD patients, a finding that needs confirmation in further studies.

Extracorporeal membrane oxygenation to rescue profound pulmonary hemorrhage due to idiopathic pulmonary hemosiderosis in a child.

Idiopathic pulmonary hemosiderosis (IPH) is a rare cause of diffuse alveolar hemorrhage (DAH) in pediatric patients. During the acute phase, death due to massive alveolar hemorrhage and subsequent severe respiratory failure with associated multiple organ failure often occurs. We report the case of an 11-year-old girl who developed severe hypoxemic respiratory failure and pulmonary hemorrhage. Extracorporeal membrane oxygenation (ECMO) was instituted on the next day because medical treatment and mechanical ventilation failed to maintain oxygenation. She was successfully decannulated 5 days later without ECMO-related complications. Four months later, she was intubated again and the diagnosis of IPH was made by open lung biopsy. She was treated with systemic steroid therapy and discharged smoothly. We suggest that ECMO provides a chance of recovery and survival for patients with IPH, even if accompanied by severe pulmonary hemorrhage.

Premature with trichomoniasis: report of one case.

We report a case of an extremely-low-birth-weight premature infant with Trichomonas vaginalis infection of the vagina and urinary tract. Her mother is also infected with Trichomonas vaginalis but is asymptomatic. The patient's illness started as an asymptomatic pyuria and later on at early infancy developed profuse malodorous vaginal discharge. Her vaginal discharge was positive for Trichomonas vaginalis, both on wet mount and Papanicolaou smear, and the infection responded well to treatment with metronidazole. Infants with recurrent vaginal discharge presenting beyond the neonatal period may be attributed to T. vaginalis infection.

Persistent truncus arteriosus: twenty years experience in a tertiary care center in Taiwan.

BACKGROUND: Persistent truncus arteriosus (PTA) is a rare congenital heart disease. The disease spectrum and outcome in the Oriental are still unclear. METHODS AND RESULTS: A total of 35 patients with PTA were identified from the Pediatric Cardiology Database of this institution, giving an incidence of 0.47%. According to the Van Praagh classification, we found type A1 in 16, A2 in 10, A3 in 4 and A4 in 5 patients. The most common truncal valves were still tricuspid (57.1%) and quadricuspid (28.5%), with the latter being associated with moderate to severe truncal regurgutation. Eleven patients had not received surgery and all died. We classified the era of operation as early (between 1980 and 1995) or late (1996-2001), and further classified the type of PTA as simple (type A1 or A2) or complex (interrupted aortic arch-A4, absent orifice of one PA from truncal root-A3 or moderate truncal valve insufficiency). The overall surgical mortality was 67%. Statistical analysis revealed that age at operation (older than 6 months), early operation era and complex PTA were risk factors for survival. CONCLUSIONS: PTA is a rare form of congenital heart disease in Taiwan and probably also in the Oriental. The surgical reparation seems to improve with experience. Early operation may prevent pulmonary vasculopathy. However, the results in complex PTA remain poor.