Rapid growth of new atmospheric particles by nitric acid and ammonia condensation.

A list of authors and their affiliations appears at the end of the paper New-particle formation is a major contributor to urban smog1,2, but how it occurs in cities is often puzzling3. If the growth rates of urban particles are similar to those found in cleaner environments (1-10 nanometres per hour), then existing understanding suggests that new urban particles should be rapidly scavenged by the high concentration of pre-existing particles. Here we show, through experiments performed under atmospheric conditions in the CLOUD chamber at CERN, that below about +5 degrees Celsius, nitric acid and ammonia vapours can condense onto freshly nucleated particles as small as a few nanometres in diameter. Moreover, when it is cold enough (below -15 degrees Celsius), nitric acid and ammonia can nucleate directly through an acid-base stabilization mechanism to form ammonium nitrate particles. Given that these vapours are often one thousand times more abundant than sulfuric acid, the resulting particle growth rates can be extremely high, reaching well above 100 nanometres per hour. However, these high growth rates require the gas-particle ammonium nitrate system to be out of equilibrium in order to sustain gas-phase supersaturations. In view of the strong temperature dependence that we measure for the gas-phase supersaturations, we expect such transient conditions to occur in inhomogeneous urban settings, especially in wintertime, driven by vertical mixing and by strong local sources such as traffic. Even though rapid growth from nitric acid and ammonia condensation may last for only a few minutes, it is nonetheless fast enough to shepherd freshly nucleated particles through the smallest size range where they are most vulnerable to scavenging loss, thus greatly increasing their survival probability. We also expect nitric acid and ammonia nucleation and rapid growth to be important in the relatively clean and cold upper free troposphere, where ammonia can be convected from the continental boundary layer and nitric acid is abundant from electrical storms4,5.

Maternal and neonatal outcomes in women with congenital heart disease: A nationwide population-based study.

BACKGROUND: We evaluated the outcomes of pregnancy in women with congenital heart disease (CHD) and their offspring in Taiwan. We also investigated how different severity levels may influence the outcomes. METHODS: We used data (2009-2017) from the Birth Certificate Application database in Taiwan, which is linked to the National Health Insurance Research Database and Taiwan Maternal and Child Health Database. We identified 2990 women with CHD who had 4227 births. Based on the CHD subtypes, patients were further divided into "severe CHD" and "simple CHD" groups. RESULTS: Women with CHD have a significant risk of stillbirth. In maternal cardiac events, they had the highest risk of heart failure, followed by arrhythmia. The severity of CHD had a significant effect on the outcomes as well. The neonatal birth event that mothers with CHD have the highest risk of is preterm birth at < 32 weeks of gestation. The prominent difference in neonatal morbidities between mothers with severe and simple CHD is recurrent CHD in the offspring. The offspring of the severe CHD group had a higher risk of severe CHD, whereas those of the simple CHD group had a higher risk of simple CHD. CONCLUSION: During pregnancy, the monitoring of heart function and cardiac rhythm could be more intensive in mothers with CHD. In addition to accurately assessing fetal growth and development during antenatal care, mothers with severe CHD should be provided with careful fetal heart structure assessment and genetic testing along with counseling.

Maternal risk factors associated with offspring biliary atresia: population-based study.

BACKGROUND: Biliary atresia (BA) is a progressive, idiopathic, fibro-obliterative disease of the intra and extrahepatic biliary tree. If untreated, it results in severe liver injury and death. The etiology and pathogenesis of BA remain unclear. Few studies have investigated the association between maternal illness/drug use and the occurrence of BA in offspring. METHODS: We used the data from the Birth Certificate Application of Taiwan and linked to National Health Insurance Research Database and Taiwan Maternal and Child Health Database for the years 2004 to 2017 (N = 1,647,231) on 2022/03, and identified BA cases according to diagnosis and procedure code. A total of 285 BA cases were identified. RESULTS: Mothers with type 2 diabetes mellitus and non-dependent drug abuse had higher rates having BA children than non-BA children, with an odds ratio of 2.17 (95% confidence interval [CI] = 1.04-4.53) and OR: 3.02 (95% CI = 1.34-6.78), respectively. CONCLUSION: These results support the notion that BA occurrence is related to maternal reasons. Further studies should be designed to identify additional maternal and pregnancy risk factors and to understand the underlying pathophysiology. IMPACT: 1. The occurrence of offspring biliary atresia may be related to maternal illness/drug use. 2. Maternal drug abuse and type 2 diabetes mellitus pose a high risk for offspring biliary atresia. 3. If maternal etiology is found, biliary atresia might be a preventable disease.

Ultraselective Extraction Reprocessing of 99TcO4-/ReO4- with a Promising Carbamic Acid Extractant System.

With the development of nuclear energy, the reprocessing of 99TcO4-/ReO4- has become a very difficult problem due to environmental issues such as high output, long life, and easy leakage. In this study, three extraction systems containing carbamic acid were introduced into the reprocessing of 99TcO4-/ReO4- for the first time. The results involving one of the three results show that N-[N,N-di(2-ethylhexyl) aminocarbonylmethyl] glycine (D2EHAG) has ultrahigh selectivity for removal to 99TcO4-/ReO4-. When the extreme concentration ratio of SO42- and Cl- to ReO4- of D2EHAG is 10,000:1, the distribution coefficient of ReO4- still reaches 12.73 and 2.67, respectively. Additionally, the most hydrophilic NO3-, when the extreme concentration ratio of NO3- and ReO4- is 1000:1, still has a distribution coefficient close to 2.33, which is more than the most reported MOF adsorption materials. Moreover, the reaction kinetics, stripping rate, and reuse rate were studied. After five cycles, the removal rate is still 98.12%, with a decrease of less than 0.7%. The system containing carbamic acid is a potential extraction removal system to remove 99TcO4-/ReO4- from nuclear radioactive wastewater.

Polypyrrole-coated copper@graphene core-shell nanoparticles for supercapacitor application.

The performance of supercapacitors strongly depends on the electrochemical characterizations of electrode materials. Herein, a composite material consisted of polypyrrole (PPy) and multilayer graphene-wrapped copper nanoparticles (PPy/MLG-Cu NPs) is fabricated on a flexible carbon cloth (CC) substrate via two-step synthesis process for supercapacitor application. Where, MLG-Cu NPs are prepared on CC by one-step chemical vapor deposition synthesis approach; thereafter, the PPy is further deposited on the MLG-Cu NPs/CC via electropolymerization. The related material characterizations of PPy/MLG-Cu NPs are well investigated by scanning electron microscopic, high resolution transmission electron microscopy, Raman spectrometer and x-ray photoelectron spectroscopy; the electrochemical behaviors of the pertinent electrodes are studied by cyclic voltammogram, galvanostatic charge/discharge and electrochemical impedance spectroscopy measurements. The flexible electrode with PPy/MLG-Cu NPs composites exhibits the best specific capacitance of 845.38 F g-1at 1 A g-1, which is much higher than those of electrodes with PPy (214.30 F g-1), MLG-Cu NPs (6.34 F g-1), multilayer graphene hollow balls (MLGHBs; 52.72 F g-1), and PPy/MLGHBs (237.84 F g-1). Finally, a supercapacitor system consisted of four PPy/MLG-Cu NPs/CC electrodes can efficiently power various light-emitting diodes (i.e. red, yellow, green and blue lighs), demonstrating the practical application of PPy/MLG-Cu NPs/CC electrode.

Synthesis of non-planar graphene-wrapped copper nanoparticles with iron(III) oxide decoration for high performance supercapacitors.

The performance of supercapacitors strongly depends on the electrochemical characterizations of electrode materials. Herein, a composite material consisted of iron(III) oxide (Fe2O3) and multilayer graphene-wrapped copper nanoparticles (Fe2O3/MLG-Cu NPs) is fabricated on a flexible carbon cloth (CC) substrate via two-step synthesis process for supercapacitor application. Where, MLG-Cu NPs are prepared on CC by one-step chemical vapor deposition synthesis approach; thereafter, the Fe2O3is further deposited on the MLG-Cu NPs/CC via successive ionic layer adsorption and reaction method. The related material characterizations of Fe2O3/MLG-Cu NPs are well investigated by scanning electron microscopic, high resolution transmission electron microscopy), Raman spectrometer and X-ray photoelectron spectroscopy; the electrochemical behaviors of the pertinent electrodes are studied by cyclic voltammogram, galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy measurements. The flexible electrode with Fe2O3/MLG-Cu NPs composites exhibits the best specific capacitance of 1092.6 mF cm-2at 1 A g-1, which is much higher than those of electrodes with Fe2O3(863.7 mF cm-2), MLG-Cu NPs (257.4 mF cm-2), multilayer graphene hollow balls (MLGHBs, 14.4 mF cm-2) and Fe2O3/MLGHBs (287.2 mF cm-2). Fe2O3/MLG-Cu NPs electrode also exhibits an excellent GCD durability, and its capacitance remains 88% of its original value after 5000 cycles of the GCD process. Finally, a supercapacitor system consisted of four Fe2O3/MLG-Cu NPs/CC electrodes can efficiently power various light-emitting diodes (i.e. red, yellow, green, and blue lights), demonstrating the practical application of Fe2O3/MLG-Cu NPs/CC electrode.

Molecular Understanding of the Enhancement in Organic Aerosol Mass at High Relative Humidity.

The mechanistic pathway by which high relative humidity (RH) affects gas-particle partitioning remains poorly understood, although many studies report increased secondary organic aerosol (SOA) yields at high RH. Here, we use real-time, molecular measurements of both the gas and particle phase to provide a mechanistic understanding of the effect of RH on the partitioning of biogenic oxidized organic molecules (from α-pinene and isoprene) at low temperatures (243 and 263 K) at the CLOUD chamber at CERN. We observe increases in SOA mass of 45 and 85% with increasing RH from 10-20 to 60-80% at 243 and 263 K, respectively, and attribute it to the increased partitioning of semi-volatile compounds. At 263 K, we measure an increase of a factor 2-4 in the concentration of C10H16O2-3, while the particle-phase concentrations of low-volatility species, such as C10H16O6-8, remain almost constant. This results in a substantial shift in the chemical composition and volatility distribution toward less oxygenated and more volatile species at higher RH (e.g., at 263 K, O/C ratio = 0.55 and 0.40, at RH = 10 and 80%, respectively). By modeling particle growth using an aerosol growth model, which accounts for kinetic limitations, we can explain the enhancement in the semi-volatile fraction through the complementary effect of decreased compound activity and increased bulk-phase diffusivity. Our results highlight the importance of particle water content as a diluting agent and a plasticizer for organic aerosol growth.

Association between initial in-hospital heart rate and glycemic control in patients with acute ischemic stroke and diabetes mellitus.

BACKGROUND: A high resting heart rate (HR) has been associated with an increased risk of diabetes mellitus. This study explored the association between initial in-hospital HR and glycemic control in patients with acute ischemic stroke (AIS) and diabetes mellitus. METHODS: We analyzed data from 4,715 patients with AIS and type 2 diabetes mellitus enrolled in the Chang Gung Research Database between January 2010 and September 2018. The study outcome was unfavorable glycemic control, defined as glycated hemoglobin (HbA1c) ≥ 7%. In statistical analyses, the mean initial in-hospital HR was used as both a continuous and categorical variable. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression analysis. The associations between the HR subgroups and HbA1c levels were analyzed using a generalized linear model. RESULTS: Compared with the reference group (HR < 60 bpm), the adjusted ORs for unfavorable glycemic control were 1.093 (95% CI 0.786-1.519) for an HR of 60-69 bpm, 1.370 (95% CI 0.991-1.892) for an HR of 70-79 bpm, and 1.608 (95% CI 1.145-2.257) for an HR of ≥ 80 bpm. Even after adjusting for possible confounders, the HbA1c levels after admission and discharge among diabetic stroke patients increased significantly in the subgroups with higher HRs (p < 0.001). CONCLUSIONS: High initial in-hospital HR is associated with unfavorable glycemic control in patients with AIS and diabetes mellitus, particularly in those with an HR of ≥ 80 bpm, compared with those with an HR of < 60 bpm.

High Gas-Phase Methanesulfonic Acid Production in the OH-Initiated Oxidation of Dimethyl Sulfide at Low Temperatures.

Dimethyl sulfide (DMS) influences climate via cloud condensation nuclei (CCN) formation resulting from its oxidation products (mainly methanesulfonic acid, MSA, and sulfuric acid, H2SO4). Despite their importance, accurate prediction of MSA and H2SO4 from DMS oxidation remains challenging. With comprehensive experiments carried out in the Cosmics Leaving Outdoor Droplets (CLOUD) chamber at CERN, we show that decreasing the temperature from +25 to -10 °C enhances the gas-phase MSA production by an order of magnitude from OH-initiated DMS oxidation, while H2SO4 production is modestly affected. This leads to a gas-phase H2SO4-to-MSA ratio (H2SO4/MSA) smaller than one at low temperatures, consistent with field observations in polar regions. With an updated DMS oxidation mechanism, we find that methanesulfinic acid, CH3S(O)OH, MSIA, forms large amounts of MSA. Overall, our results reveal that MSA yields are a factor of 2-10 higher than those predicted by the widely used Master Chemical Mechanism (MCMv3.3.1), and the NOx effect is less significant than that of temperature. Our updated mechanism explains the high MSA production rates observed in field observations, especially at low temperatures, thus, substantiating the greater importance of MSA in the natural sulfur cycle and natural CCN formation. Our mechanism will improve the interpretation of present-day and historical gas-phase H2SO4/MSA measurements.

Propensity-Score Matched Analyses Comparing Clinical Outcomes of Minimally Invasive Versus Open Distal Pancreatectomies: A Single-Center Experience.

BACKGROUND: Minimally invasive distal pancreatectomy (MIDP) is being adopted increasingly worldwide. This study aimed to compare the short-term outcomes of patients who underwent MIDP versus open distal pancreatectomy (ODP). METHODS: A retrospective review of all patients who underwent a DP in our institution between 2005 and 2019 was performed. Propensity score matching based on relevant baseline factors was used to match patients in the ODP and MIDP groups in a 1:1 manner. Outcomes reported include operative duration, blood loss, postoperative length of stay, morbidity, mortality, postoperative pancreatic fistula rates, reoperation and readmission. RESULTS: In total, 444 patients were included in this study. Of 122 MIDP patients, 112 (91.8%) could be matched. After matching, the median operating time for MIDP was significantly longer than ODP [260 min (200-346.3) vs 180 (135-232.5), p < 0.001], while postoperative stay for MIDP was significantly shorter [median 6 days (5-8) versus 7 days (6-9), p = 0.015]. There were no significant differences noted in any of the other outcomes measured. Over time, we observed a decrease in the operation times of MIDP performed at our institution. CONCLUSION: Adoption of MIDP offers advantages over ODP in terms of a shorter postoperative hospital stay, without an increase in morbidity and/or mortality but at the expense of a longer operation time.

Survey of factors associated with the willingness toward living kidney donation.

BACKGROUND: Living donor kidney transplantation (LDKT) is an important organ resource, especially in countries with low deceased donation rates. Strategies for expanding access to transplantation should be developed by identifying the modifiable factors. In this study, we evaluated these factors in the relatives of patients from both medical centers and dialysis clinics using questionnaires. METHODS: The questionnaires were anonymous and confidential. We collected questionnaires from previous donors, relatives of patients on the waitlist in the medical center, and relatives of dialysis patients in three nephrology clinics. The study groups were divided into three categories: donor group (n = 68), willing group (n = 43), and non-donor group (n = 65). RESULTS: Respondents in the clinics had lower cognition and willingness towards LDKT than those in the medical center. More knowledge of LDKT, better relationship with patients, more familial support, and female gender were positively related to donation. The non-donor group tended to want to maintain an intact body for the afterlife. There was no significant difference in age, educational degree, average monthly income, and medical compliance among the three groups. CONCLUSION: More efforts need to be made in dialysis clinics, where general nephrologists are important for the outreach of information. In addition, dealing with religious ambivalence and reestablishing cultural mindsets with health education programs are important issues in a non-Christian country.

Short- and long-term outcomes after minimally invasive versus open spleen-saving distal pancreatectomies.

INTRODUCTION: This study aimed to compare the perioperative outcomes of patients who underwent minimally invasive spleen-preserving distal pancreatectomy (MI-SPDP) versus open surgery SPDP (O-SPDP). It also aimed to determine the long-term vascular patency after spleen-saving vessel-preserving distal pancreatectomies (SSVDPs). METHODS: A retrospective review of 74 patients who underwent successful SPDP and met the study criteria was performed. Of these, 67 (90.5%) patients underwent SSVDP, of which 38 patients (21 open, 17 MIS) had adequate long-term post-operative follow-up imaging to determine vascular patency. RESULTS: Fifty-one patients underwent open SPDP, whereas 23 patients underwent minimally invasive SPDP, out of which 10 (43.5%) were laparoscopic and 13 (56.5%) were robotic. Patients who underwent MI-SPDP had significantly longer operative time (307.5 vs. 162.5 min, P = 0.001) but shorter hospital stay (5 vs. 7 days, P = 0.021) and lower median blood loss (100 vs. 200 cc, P = 0.046) compared to that of O-SPDP. Minimally-invasive spleen-saving vessel-preserving distal pancreatectomy (MI-SSVDP) was associated with poorer long-term splenic vein patency rates compared to O-SSVDP (P = 0.048). This was particularly with respect to partial occlusion of the splenic vein, and there was no significant difference between the complete splenic vein occlusion rates between the MIS group and open group (29.4% vs. 28.6%, P = 0.954). The operative time was statistically significantly longer in patients who underwent robotic surgery versus laparoscopic surgery (330 vs. 173 min, P = 0.008). CONCLUSION: Adoption of MI-spleen-preserving distal pancreatectomy (SPDP) is safe and feasible. MI-SPDP is associated with a shorter hospital stay, lower blood loss but longer operation time compared to O-SPDP. In the present study, MI-SSVDP was associated with poorer long-term splenic vein patency rates compared to O-SSVDP.

Investigation of anxiety and depressive disorders and psychiatric medication use before and after cancer diagnosis.

OBJECTIVE: Data regarding the prevalence of depression and anxiety among cancer patients, especially before cancer diagnosis, remains scarce. This study investigated the prevalence of these conditions and associated drug use among cancer patients pre- and post-diagnosis. METHODS: This population-based cohort study using data from Taiwan's National Health Insurance Research Database recruited patients with a registered cancer diagnosis and matched control between January 1, 2000, and December 31, 2011. We compared the prevalence of anxiety and depressive disorders between cancer patients and non-cancer participants during a 2-year period both pre- and post-diagnosis by Pearson's chi-square test. Psychiatric medication use was also examined for the associated mental condition. RESULTS: We examined participants diagnosed with liver (N = 17,154), colorectal (N = 30,391), breast (N = 40,036), gynecological (N = 23,218), and lung (N = 15,671) cancer. Before the cancer diagnosis, the prevalence of depression was higher in non-cancer participants than in gynecological cancer patients (p = 0.018) but anxiety is higher in liver, colorectal, and lung cancer patients when compared to non-cancer participants (p < 0.05). After the cancer diagnosis, the prevalence of anxiety and depression became significantly higher in all enrolled cancer patients than non-cancer participants (p < 0.05). Similar results were observed in psychiatric medication use trends. CONCLUSIONS: This study proposed that patients with liver, colorectal, and lung cancer had an increased risk of developing anxiety, which might be a sentinel diagnosis. The participants had a significantly higher level of anxiety and depressive disorder post-diagnosis, which highlights the importance of the care for both mental and physical conditions in cancer management.

Effectiveness of N-acetylcysteine in autism spectrum disorders: A meta-analysis of randomized controlled trials.

OBJECTIVE: Currently, pharmaceutical treatment options for autism spectrum disorder are limited. Brain glutaminergic dysregulation is observed in autism spectrum disorder. N-acetylcysteine, which can be converted to glutathione and subsequently release glutamate into the extracellular space, and thus reduce glutamatergic neurotransmission at synapses, is considered a potential drug for autism spectrum disorder treatment. Here, we analyzed the treatment effects of N-acetylcysteine on autism spectrum disorder in randomized controlled trials. STUDY DESIGN: Updated systematic review and meta-analysis. DATA SOURCES: By systematically searching the PubMed, Embase and Cochrane Library, we obtained five randomized controlled trials. STUDY SELECTION: Meta-analyses were performed to examine the improvement in autistic behaviors as measured by the Aberrant Behavior Checklist, Social Responsiveness Scale and Repetitive Behavior Scale-Revised, using mean difference with a 95% confidence interval and a random-effects model. DATA SYNTHESIS: After 8-12 weeks of N-acetylcysteine supplementation, the pooled result of four trials revealed an improvement in Aberrant Behavior Checklist total score (mean difference = 1.31, 95% confidence interval = [0.42, 2.20]). When one trial was excluded, the sensitivity test result was stronger (mean difference = 1.88, 95% confidence interval = [0.92, 2.83]). The pooled results of three trials revealed significant improvements in hyperactivity (mean difference = 4.80, 95% confidence interval = [1.20, 8.40]) and irritability (mean difference = 4.07, 95% confidence interval = [1.13, 7.04]). Regarding Social Responsiveness Scale, the pooled result of two trials showed significant improvement in social awareness after 8-12 weeks of N-acetylcysteine supplementation (mean difference = 1.34, 95% confidence interval = [0.09, 2.59]). No differences were observed in the pooled results of two trials using Repetitive Behavior Scale, either in the total or the subscales. CONCLUSION: We concluded that N-acetylcysteine is safe and tolerable, reduces hyperactivity and irritability and enhances social awareness in children with autism spectrum disorder. However, further evidence should be sought before a general recommendation.

Recent Advances on Pt-Free Electro-Catalysts for Dye-Sensitized Solar Cells.

Since Prof. Grätzel and co-workers achieved breakthrough progress on dye-sensitized solar cells (DSSCs) in 1991, DSSCs have been extensively investigated and wildly developed as a potential renewable power source in the last two decades due to their low cost, low energy-intensive processing, and high roll-to-roll compatibility. During this period, the highest efficiency recorded for DSSC under ideal solar light (AM 1.5G, 100 mW cm-2) has increased from ~7% to ~14.3%. For the practical use of solar cells, the performance of photovoltaic devices in several conditions with weak light irradiation (e.g., indoor) or various light incident angles are also an important item. Accordingly, DSSCs exhibit high competitiveness in solar cell markets because their performances are less affected by the light intensity and are less sensitive to the light incident angle. However, the most used catalyst in the counter electrode (CE) of a typical DSSC is platinum (Pt), which is an expensive noble metal and is rare on earth. To further reduce the cost of the fabrication of DSSCs on the industrial scale, it is better to develop Pt-free electro-catalysts for the CEs of DSSCs, such as transition metallic compounds, conducting polymers, carbonaceous materials, and their composites. In this article, we will provide a short review on the Pt-free electro-catalyst CEs of DSSCs with superior cell compared to Pt CEs; additionally, those selected reports were published within the past 5 years.

Real-Time Detection of Aerosol Metals Using Online Extractive Electrospray Ionization Mass Spectrometry.

Metal emissions are of major environmental and practical concern because of their highly toxic effects on human health and ecosystems. Current technologies available in the market for their detection are typically limited by a time resolution of 1 h or longer (e.g., via semicontinuous X-ray fluorescence measurements) or are nonquantitative (e.g., laser ablation mass spectrometry). In this work, we report the development of a novel technique for the real-time detection and monitoring of metal particles in situ using an extractive electrospray ionization (EESI) source coupled to a high-resolution time-of-flight mass spectrometer (TOF-MS). The experiments were conducted in negative ionization mode using disodium ethylenediamine tetraacetic acid (EDTA) dihydrate to chelate with metals and form stable metal complexes. Results for water-soluble metal compounds were obtained. The following representative metal ions were examined: Pb, Cd, Zn, Ce (III), Ba, Ni, Fe(II), Fe(III), Cu(II), Cr, Mo, Co(II), Mg, Nd, Li, Ti, Ca, Cs, Ag, Tm, Er(III), La(III), Yb(III), Eu(III), Pr(III), Gd(III), Lu(III), Dy(III), Tb(III), Ho, and Ru(III). The results showed a very good linear mass response (R2 = 0.9983), low ng/m3 limits of detection (LoD), and a fast response time (1 s). The stability and repeatability of the developed EESI-TOF-MS were tested under complex dynamic and periodic experimental conditions, and negligible matrix effects were measured for internally and externally mixed metal particles. Benchmark testing against inductively coupled plasma-mass spectrometry (ICP-MS) was also performed, highlighting the online measurement capabilities of aerosol metals with a LoD lower than those of ICP-MS. Proof-of-concept ambient measurements were performed in New Delhi, India, and very promising results were obtained, allowing further exploitation elsewhere.

Online Aerosol Chemical Characterization by Extractive Electrospray Ionization-Ultrahigh-Resolution Mass Spectrometry (EESI-Orbitrap).

Current mass spectrometry techniques for the online measurement of organic aerosol (OA) composition are subjected to either thermal/ionization-induced artifacts or limited mass resolving power, hindering accurate molecular characterization. Here, we combined the soft ionization capability of extractive electrospray ionization (EESI) and the ultrahigh mass resolution of Orbitrap for real-time, near-molecular characterization of OAs. Detection limits as low as tens of ng m-3 with linearity up to hundreds of µg m-3 at 0.2 Hz time resolution were observed for single- and mixed-component calibrations. The performance of the EESI-Orbitrap system was further evaluated with laboratory-generated secondary OAs (SOAs) and filter extracts of ambient particulate matter. The high mass accuracy and resolution (140 000 at m/z 200) of the EESI-Orbitrap system enable unambiguous identification of the aerosol components' molecular composition and allow a clear separation between adjacent peaks, which would be significantly overlapping if a medium-resolution (20 000) mass analyzer was used. Furthermore, the tandem mass spectrometry (MS2) capability provides valuable insights into the compound structure. For instance, the MS2 analysis of ambient OA samples and lab-generated biogenic SOAs points to specific SOA precursors in ambient air among a range of possible isomers based on fingerprint fragment ions. Overall, this newly developed and characterized EESI-Orbitrap system will advance our understanding of the formation and evolution of atmospheric aerosols.

Effect of carvedilol on arteriovenous graft primary patency.

BACKGROUND: The major mechanisms of arteriovenous graft (AVG) failure due to intimal hyperplasia (IH) are smooth muscle cell proliferation and inflammation. Therefore, carvedilol may improve AVG primary patency because of its anti-proliferative and anti-inflammatory activities. METHODS: The data of end-stage renal disease patients receiving regular hemodialysis were collected from the National Health Insurance Research database. The end point was the first percutaneous transluminal angioplasty (PTA) for AVG failure or death during a follow-up period of two years or the end of 2013. The analysis was calculated with Cox proportional hazard model. RESULTS: There were 3028 patients treated with carvedilol and 13,704 patients not treated with carvedilol. According to a univariate analysis, the carvedilol group was younger, received more anti-hypertensive medications and platelet aggregation inhibitors, and had higher rates of diabetes mellitus and hyperlipidemia but had lower rates of hypotension and smoking. According to a multivariate analysis, after controlling for covariates, the use of carvedilol for more than 84 days reduced the probability of a first PTA for AVG failure by 9% compared with no use of carvedilol (p = 0.021), but the use of carvedilol for 1 to 84 days did not. CONCLUSION: The results of this study indicate that the use of carvedilol for more than 84 days improves the primary patency of AVGs, but the use of carvedilol for less than 84 days does not.

Geographic variation of genotype 6 hepatitis C virus infection in an endemic area of southern Taiwan.

Taiwan is a hepatitis C virus (HCV) endemic country with geographic variation of prevalence and main genotypes(GTs) are 1 b and 2a. We recently reported high GT6 prevalence in Tainan of southern Taiwan. To clarify this special genotype as a local endemic disease and its geographic variation, the prevalence rates of HCV GTs of 37 districts of Tainan were analyzed. A total of 3040 patients with HCV viremia were enrolled. The prevalence rates of HCV GT 1a, 1 b, 2, 3, 4, 6 and mixed types were 3.9%, 31.6%, 45.9%, 0.6%, 0.2%, 17.1% and 0.5% respectively. GT6 prevalence showed marked variation from 0 to 39.2%. Four districts with GT6 prevalence >30% are located between Jishui and Zengwen rivers. Preliminary subtyping data were 6 g/a/w. This geographic variation with spatial restriction by two rivers with 6 g/w is suggestive of local endemic infection of preexisting GT 6 HCV for centuries.

High prevalence of genotype 6 hepatitis C virus infection in Southern Taiwan using Abbott genotype assays.

BACKGROUND/PURPOSE: Abbott RealTime Genotype II assay can effectively identify hepatitis C virus (HCV) genotypes (GTs), but some GT 6 subtypes might not be differentiated from GT 1. Abbott RealTime Genotype II PLUS and sequencing might be needed to resolve these ambiguous results. Unlike the high prevalence of GT 6 in Southeast Asia, GT 6 had rarely been reported in Taiwan except in intravenous drug abusers (IDU). But the prevalence of GT 6 in Taiwan might be underestimated. We conducted this study to determine the GTs in a HCV endemic area in Southern Taiwan. METHODS: A total of 1147 patients with hepatitis C viremia for direct acting antivirals (DAA) treatment at the Chi Mei medical system in Tainan were enrolled. Genotype was determined using a working flow consisted of Abbott GT II, PLUS assays and 5' untranslated region (5' UTR)/core sequencing. RESULTS: Among the 1147 patients, 883 (77.0%) obtained GT results by GT II, 264 (23.0%) samples with ambiguous results by GT II assay received further tests, including 194 (73.5%) with PLUS assay and 70 (26.5%) with 5'UTR/core sequencing. Nearly three-quarters (73.5%) of ambiguous results by GT II assay were GT 6. Overall, 18.3% of samples were GT 6. Phylogenetic study of 11 samples of GT 6 subtypes showed 7 (63.6%) were 6 g. CONCLUSION: GT 6 is the major factor for high ambiguous rate by GT II. Unexpected high prevalence of GT 6 (18.3%) in Southern Taiwan, especially subtype 6 g, closely related to Indonesian strains, is first reported.