Structural Engineering on Pt-Free Electrocatalysts for Dye-Sensitized Solar Cells

In recent decades, plenty of nanomaterials have been investigated as electrocatalysts for the replacement of the expensive platinum (Pt) counter electrode in dye-sensitized solar cells (DSSCs). The key function of the electrocatalyst is to reduce tri-iodide ions to iodide ions at the electrolyte/counter electrode interface. The performance of the electrocatalyst is usually determined by two key factors, i.e., the intrinsic heterogeneous rate constant and the effective electrocatalytic surface area of the electrocatalyst. The intrinsic heterogeneous rate constant of the electrocatalyst varies by different types of materials, which can be roughly divided into five groups: non-Pt metals, carbons, conducting polymers, transition metal compounds, and their composites. The effective electrocatalytic surface area is determined by the nanostructure of the electrocatalyst. In this chapter, the nanostructural design and engineering on different types of Pt-free electrocatalysts will be systematically introduced. Also, the relationship between various nanostructures of electrocatalysts and the pertinent physical/electrochemical properties will be discussed

Open circuit voltage and state of charge relationship functional optimization for the working state monitoring of the aerial lithium-ion battery pack.

The aerial lithium-ion battery pack works differently from the usual battery packs, the working characteristic of which is intermittent supplement charge and instantaneous large current discharge. An adaptive state of charge estimation method combined with the output voltage tracking strategy is proposed by using the reduced particle - unscented Kalman filter, which is based on the reaction mechanism and experimental characteristic analysis. The improved splice equivalent circuit model is constructed together with its state-space description, in which the operating characteristics can be obtained. The relationship function between the open circuit voltage and the state of charge is analyzed and especially optimized. The feasibility and accuracy characteristics are tested by using the aerial lithium-ion battery pack experimental samples with seven series-connected battery cells. Experimental results show that the state of charge estimation error is less than 2.00%. The proposed method achieves the state of charge estimation accurately for the aerial lithium-ion battery pack, which provides a core avenue for its high-power supply security

Demineralized Bone Matrix Combined Bone Marrow Mesenchymal Stem Cells, Bone Morphogenetic Protein-2 and Transforming Growth Factor-β3 Gene Promoted Pig Cartilage Defect Repair

Objectives To investigate whether a combination of demineralized bone matrix (DBM) and bone marrow mesenchymal stem cells (BMSCs) infected with adenovirus-mediated- bone morphogenetic protein (Ad-BMP-2) and transforming growth factor-β3 (Ad-TGF-β3) promotes the repair of the full-thickness cartilage lesions in pig model. Methods BMSCs isolated from pig were cultured and infected with Ad-BMP-2(B group), Ad-TGF-β3 (T group), Ad-BMP-2 + Ad-TGF-β3(BT group), cells infected with empty Ad served as a negative group(N group), the expression of the BMP-2 and TGF-β3 were confirmed by immunofluorescence, PCR, and ELISA, the expression of SOX-9, type II collagen(COL-2A), aggrecan (ACAN) in each group were evaluated by real-time PCR at 1w, 2w, 3w, respectively. The chondrogenic differentiation of BMSCs was evaluated by type II collagen at 21d with immunohistochemical staining. The third-passage BMSCs infected with Ad-BMP-2 and Ad-TGF-β3 were suspended and cultured with DBM for 6 days to construct a new type of tissue engineering scaffold to repair full-thickness cartilage lesions in the femur condyles of pig knee, the regenerated tissue was evaluated at 1,2 and 3 months after surgery by gross appearance, H&E, safranin O staining and O\u27driscoll score. Results Ad-BMP-2 and Ad-TGF-β3 (BT group) infected cells acquired strong type II collagen staining compared with Ad-BMP-2 (B group) and Ad-TGF-β3 (T group) along. The Ad-BMP-2 and Ad-TGF-β3 infected BMSCs adhered and propagated well in DBM and the new type of tissue engineering scaffold produced hyaline cartilage morphology containing a stronger type II collagen and safranin O staining, the O\u27driscoll score was higher than other groups. Conclusions The DBM compound with Ad-BMP-2 and Ad-TGF-β3 infected BMSCs scaffold has a good biocompatibility and could well induce cartilage regeneration to repair the defects of joint cartilage. This technology may be efficiently employed for cartilage lesions repair in vivo

Effects of thyroid dysfunction on the severity of coronary artery lesions and its prognosis

AbstractBackgroundAbnormal thyroid hormone metabolism influences the occurrence and progress of coronary heart disease (CHD). The aim of the present study was to analyze the severity of coronary artery lesions and the prognosis of thyroid dysfunction patients admitted for coronary angiography (CAG).MethodsFrom July 2011 to July 2012, 605 consecutive patients with suspected coronary heart disease admitted for CAG were selected. The patients were divided into three groups, based on their thyroid function prior to CAG: euthyroid group (n=455 patients), low T3 syndrome group (n=96 patients), and hypothyroidism group (n=54 patients). All patients underwent CAG. Then the severity of coronary artery lesions was assessed by Gensini scores. All patients were followed up for major adverse cardiac events.ResultsThe prevalence of CHD in low T3 syndrome group and hypothyroidism group was significantly higher than that in the euthyroid group (p<0.001 and p=0.004, respectively). Moreover, the severity of coronary artery lesions in low T3 syndrome group and hypothyroidism group was significantly greater than that in the euthyroid group (all p<0.001). Multinomial logistic regression analysis demonstrated that low T3 syndrome was an independent risk factor of coronary artery moderate [odds ratio (OR)=4.268, 95% CI: 3.294–7.450, p=0.016] and severe (OR=4.294, 95% CI: 2.259–9.703, p<0.001) lesions. The mean duration of follow-up was 15.3±3.8 months; patients with thyroid dysfunction had a significantly worse prognosis as compared to those in the euthyroid group for the composite end-point (p<0.01). Moreover, the incidence of the composite end-point (all-cause death, non-fatal myocardial infarction, and coronary revascularization) was significantly higher in low T3 syndrome group and hypothyroidism group compared with that of in the euthyroid group (all p<0.001).ConclusionsThe patients with hypothyroidism and low T3 syndrome had a high prevalence of CHD, increased severity of coronary artery lesions and poor prognosis

An Outbreak of Coxsackievirus A16 Infection: Comparison With Other Enteroviruses in a Preschool in Taipei

Background/PurposeThe transmission rate of enteroviruses in young children remains unclear. Therefore, we carried out active surveillance in preschool children to investigate the transmission rate and clinical manifestation of enteroviruses.MethodsFrom September 2006 to December 2008, we monitored infectious diseases in children 2(–3 years of age) in a preschool in Taipei. If any child had a febrile illness or symptoms/signs of enteroviral infection [e.g. herpangina or hand-foot-and-mouth disease (HFMD)], we performed viral isolation and enterovirus polymerase chain reaction. VP1 sequencing was performed to define their serotypes. We also collected clinical data and analyzed transmission rates.ResultsThere were eight episodes of enterovirus infection during the study period. The serotypes included coxsackievirus A4 (CA4), CA2 and CA16. The transmission rates of CA4 and CA2 among children in same class were 26% and 35%, respectively. Between November 28 and December 12, 2008, 13/21 (61.9%) children contracted herpangina and/or HFMD. The average age was 2.82 (range, 2.43–3.39) years. CA16 was detected in 10/13 (76.9%) of the throat swabs by polymerase chain reaction VP1 genotyping. Compared with previous CA2 and CA4 outbreaks, CA16 had a significantly higher transmission rate (p = 0.035) and resulted in more cases of HFMD (p < 0.001). The transmission duration of coxsackie A viruses within the same class ranged from 12 to 40 days.ConclusionCompared with CA2 and CA4, CA16 infections resulted in more cases of HFMD and had significantly higher transmission rates in preschoolers

Viral load and clinical features in children infected with seasonal influenza B in 2006/2007

Background/PurposeIn influenza B infection, viral load is believed to be related to the severity of clinical illness. The correlation between viral load and symptoms is not known. We conducted a study to assess the relationship between virus load and clinical features in children infected with influenza B, in the hope that clinical features could be used as surrogate markers of viral load to guide treatment.MethodsBetween December 2006 and February 2007, 228 patients with fever and respiratory symptoms were prospectively enrolled in our tertiary hospital-based study. Real-time reverse transcription polymerase chain reaction (RT-PCR) was performed to determine viral load.ResultsReal-time RT-PCR was positive for influenza B in 76 patients. Using virus culture as the gold standard, the sensitivity and specificity were 95% and 87%, respectively. Influenza culture positive rate significantly correlated with viral load (p = 0.03). The median copy number of influenza B virus in the 76 RT-PCR positive patients was 9735 copies/ml (range 4.8×101–2.0×106 copies/ml). Samples obtained later in the clinical course tended to have lower viral load (p = 0.7), while patient age (p = 0.72) and fever duration (p = 0.96) positively related to viral load. In patients >3 years of age, myalgia was related to statistically lower viral loads (14300 vs. 1180; p = 0.025). Patients with chills tended to have higher viral loads (72450 vs. 7640; p = 0.1). Patients with abdominal pain tended to have lower viral loads (1998 vs. 12550; p = 0.06).ConclusionCulture rate positively correlated with viral load. Patients with myalgia had a lower viral load