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Abstract Background The data are inconsistent regarding whether extreme N-terminal fragment pro-B-type natriuretic peptide (NT pro-BNP) levels are associated with impaired renal function. Furthermore, the relationship between extreme NT pro-BNP levels and cardiac and renal function in elderly patients has not been reported. The aim of the present study was to examine a hypothesis that extreme NT pro-BNP levels may be associated with impaired cardiac and renal function in elderly patients. Methods We retrospectively analyzed the data of demographic, clinical, and echocardiographic features on 152 consecutive elderly patients aged more than 80 years old (average age, 83.65 ± 3.58 years) with NT pro-BNP levels ≥ 3000 pg/ml. The participants were divided into two categories according to their NT pro-BNP levels: (1) 3000–10000 pg/mL and (2) >10000 pg /mL. Results The number of patients with impaired renal function (P = 0.019) and the mortality (P 10000 pg /mL. The levels of serum creatinine and creatine kinase MB (CK-MB) in the group of NT pro-BNP > 10000 pg / mL were higher than those in the group of NT pro-BNP = 3000-10000 pg/mL (P = 0.001 and P = 0.023, respectively). Furthermore, no significant difference in the distribution by NYHA class in different NT pro-BNP levels was observed. Multiple linear regression analyses demonstrated that with NT pro-BNP levels as the dependent variable, NT pro-BNP levels were positively correlated with CK-MB (β = 0.182, P = 0.024) and creatinine levels (β = 0.281, P = 0.001). The area under the receiver-operating characteristic (ROC) curve of NT pro-BNP levels and clinical diagnosis of impaired renal function was 0.596 and reached significant difference (95%CI:0.503-0.688, P = 0.044). Conclusion These data suggest that the extreme elevation of NT pro-BNP levels (≥3000 pg/ml) is mainly determined by impaired renal function in elderly patients above 80 years. Extreme NT pro-BNP levels may be useful for assessing the severity of impaired renal function.

Abstract Background Platelet-derived growth factor D (PDGF-D) plays an important role in angiogenesis, vessel remodeling, inflammation and repair in response to injury. We hypothesized that genetic variation in PDGFD gene might alter the susceptibility to stroke. Findings We determined the genotypes of a single nucleotide polymorphism (SNP) (-858A/C, rs3809021) in 1484 patients with stroke (654 cerebral thrombosis, 419 lacunar infarction, 411 intracerebral hemorrhage [ICH]) and 1528 control subjects from an unrelated Chinese Han population and followed the stroke patients up for a median of 4.5 years. The -858AA genotype showed significantly increased risk of ICH (dominant model: odds ratio [OR] 1.29, 95% confidence interval [CI] 1.00-1.68, P = 0.05; additive model: OR 1.24, 95% CI 1.01-1.52, P = 0.04) than wild-type genotype. Further analyses showed that -858AA genotype conferred about 2-fold increase in risk of non-hypertensive ICH (dominant model: OR 2.1, 95%CI 1.34-3.29, P = 0.001; additive model: OR 1.75, 95% CI 1.24-2.46, P = 0.001). After a median follow-up of 4.5 years, -858AA genotype was associated with a reduced risk of ICH recurrence (dominant model: adjusted hazard ratio [HR] 0.09, 95%CI 0.01-0.74, P = 0.025; additive model: HR 0.21, 95% CI 0.04-1.16, P = 0.073) in non-hypertensive patients. Conclusions The -858AA genotype is probably associated with risk for non-hypertensive ICH. Further studies should be conducted to reveal the role of PDGF-D at various stages of ICH development--beneficial, or deleterious.

Summary: Subzero start‐up of the polymer electrolyte membrane fuel cell (PEMFC) is one of the most challenging tasks to be solved before commercialization. During the subzero start‐up process, water generated in the oxygen reduction reaction at the cathode side of PEMFC is susceptible to freeze，which makes active sites covered by the ice and gases failed to reach the surface of the catalyst layer (CL), leading to a substantial decay and even ending up with a failure of the start‐up. Given that many factors affect the cold start process, the relative contribution of the essential factors on the cold start process is independently analyzed using first‐order finite‐difference sensitivity analysis from −20°C to −30°C. The effect of essential parameters on the cold start process is quantified. The investigated parameters include the ratio of bipolar plate (BP) thickness to that of the CL (RBP/CL), the starting voltage (Vini), stoichiometry ratios, inlet gas temperature (Tin), the porosity of the CL (εCL), initial membrane water content (λini), membrane thickness (θmem), the volume fraction of ionomer (ωCL) in CLs, and the heat capacity of the BP (ρcpBP). Results show that the cold start process is most sensitive to RBP/CL and λini. Significant improvement of cold start performance can be achieved by appropriately adjusting RBP/CL, λini, Tin, and εCL. Appropriately increasing the Vini also can be a method to improve cold start performance, especially for the cold start from −30°C. Besides, optimized ωCL in CLs, proper θmem, and lower ρcpBP can contribute to better performance, especially for the cold start from −20°C. [ABSTRACT FROM AUTHOR]