T. Zhu

Evidence of Reactive Aromatics As a Major Source of Peroxy Acetyl Nitrate over China

We analyze the observations of near-surface peroxy acetyl nitrate (PAN) and its precursors in Beijing, China in August of 2007. The levels of PAN are remarkably high (up to 14 ppbv), surpassing those measured over other urban regions in recent years. Analyses employing a 1-D version of a chemical transport model (Regional chEmical and trAnsport Model, REAM) indicate that aromatic non-methane hydrocarbons (NMHCs) are the dominant (55-75%) PAN source. The major oxidation product of aromatics that produces acetyl peroxy radicals is methylglyoxal (MGLY). PAN and O(3) in the observations are correlated at daytime; aromatic NMHCs appear to play an important role in O(3) photochemistry. Previous NMHC measurements indicate the presence of reactive aromatics at high levels over broad polluted regions of China. Aromatics are often ignored in global and (to a lesser degree) regional 3D photochemical transport models; their emissions over China as well as photochemistry are quite uncertain. Our findings suggest that critical assessments of aromatics emissions and chemistry (such as the yields of MGLY) are necessary to understand and assess ozone photochemistry and regional pollution export in China.

Mutations of Plakophilin-2 in Chinese With Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited heart muscle disease associated with increased risks of sudden death, particularly in young, otherwise healthy, patients. The pathologic features are progressive myocardial atrophy and fibrofatty replacement. Plakophilin-2 (PKP2) is reported as the most common ARVD/C-causing gene in Western countries. In this study we aimed to determine the prevalence of PKP2 mutations in Chinese patients with ARVD/C and their phenotype characteristics. Genotype and phenotype were investigated in a cohort of 18 unrelated Chinese patients with a clinical diagnosis of ARVD/C. Direct sequencing of PKP2 led to the identification of 5 novel heterozygous mutations (R158K, Q211X, L419S, A793D, and N852fsX930) in 39% of patients (7 of 18) with ARVD/C. Among them, N852fsX930 was found in 3 unrelated young patients who presented with symptomatic ventricular tachyarrhythmia. Nevertheless, no significant difference could be detected between patients with ARVD/C with (n = 7) and without (n = 11) PKP2 mutations with regard to the phenotype characteristics and clinical outcomes. Decreased penetrance was prominent in family members. In conclusion, 5 novel PKP2 mutations were identified in a cohort of symptomatic Chinese patients with ARVD/C. N852fsX930 appeared to be a hot-spot mutation in which patients presented with a severe ARVD/C phenotype, and 2/3 had early onset of arrhythmic events. No significant difference was found in phenotype characteristics between patients with ARVD/C with and without PKP2 mutations. The decreased penetrance indicated that an ARVD/C diagnosis cannot solely rely on genotyping results.

Measurements of particle number size distributions and optical properties in urban Shanghai during 2010 World Expo: relation to air mass history

To investigate the air quality during 2010 World Expo, continuous measurements of particle number size distributions and optical parameters were performed at urban Shanghai from April to June 2010. Total particle number and volume concentrations in the size range 16–600 nm were 12 700±6200 cm−3 and 16±8 µm3/cm3, respectively. Meanwhile, the optical parameters, particle light-scattering coefficient b sp,532nm and absorption coefficient b ap,532nm were 210±140 Mm−1 and 26±20 Mm−1, respectively. Strong correlation (R=0.69) was observed between b sp,532nm and the number concentration of accumulation mode particles, especially in the specific size range 300–500 nm (R=0.87). Cluster analysis on air mass history was performed to explore the relationship between air mass origins and the optical as well as microphysical parameters. Back trajectories were classified into four major clusters. Air masses came from the west direction, in which continental aerosols were predominant, associating with the polluted cases during the summertime in Shanghai. In addition, the northern air mass showed the lower values of aerosol single scattering albedo ω 0,532nm, indicating the presence of smaller light-absorbing particles originated from the North China Plain.

From Recurrent Syncope to Sudden Cardiac Death: Clinical Characteristics in a Chinese Patient Carrying a Plakophilin-2 Gene Mutation

We report a case of Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) which illustrates the natural progression of disease in the absence of availability of an implanted cardiac defibrillator (ICD). Electrocardiograms and cardiac imaging show the progress of ARVC and these clinical milestones of disease are presented herein.

PHENOTYPE DIFFERENCE BETWEEN GENOTYPE OF PLAKOPHILIN-2 MUTATION AND DESMOGLEIN-2 MUTATION IN SYMPTOMATIC CHINESE PATIENTS WITH ARRHYTHMOGENIC RIGHT VENTRICULAR DYSPLASIA/CARDIOMYOPATHY-A REPORT FROM CHINESE ARVD REGISTRY

Objectives Arrhythmogenic Right Ventricular Dysplasia/cardiomyopathy (ARVD/C) is an inherited heart muscle disease associated mainly with the mutations of desmosome. Plakophilin-2 (PKP2) and desmoglein-2 (DSG-2) are reported as the most two common ARVD-causing genes in western countries. In this study we aim to determine the prevalence of PKP2 and DSG2 mutations in Chinese ARVD/C patients, and their phenotype characteristics. Methods Genotype and phenotype were investigated in a cohort of 23 symptomatic unrelated Han Chinese with a clinical diagnosis of ARVD. PKP2 and DSG2 genes were identified using PCR and direct sequencing. Clinical evaluation included family and personal medical histories, 12-lead electrocardiography, transthoracic echocardiography, signal average electrocardiography, 24-h ambulatory electrocardiography, and MRI in some patients. Results Five novel heterozygous mutations (R158K, Q211X, L419S, A793D and N852fsX930) of PKP2 were identified in 30% (7/23) of ARVD patients; three mutations (R46G, D494A and F531C) in DSG2 were identified 13% (3/23) of the patients. Among the positive patients initial symptoms occurred at 30±10 years. All of them documented VT. Symptoms of the patients with PKP2 mutation were severe than that of patients with DSG2 mutation, all of the patients with PKP2 mutation had syncope, but none of the patients with DSG2, they only had palpitation. most of the patients with PKP2 mutation (6/7) showed epsilon waves in ECGs but only one in patients with DSG2; 6 patients with PKP2 mutation showed inverted T wave in V1 to V3, but only one in patients with DSG2 mutation. Conclusions Five novel heterozygous mutations (R158K, Q211X, L419S, A793D and N852fsX930) of PKP2 and three heterozygous mutations (R46G, D494A and F531C) of DSG2 were identified. The study has revealed a greater frequency of occurrence of PKP2 mutations when compared to DSG2 mutations. There are some difference between patients with PKP2 mutation and that with DSG2 mutation including clinical symptom and ECGs. It seems that phenotype of PKP2 mutation were severe than that of DSG2 mutation in this cohort.