Solvent Vehicle Research Articles

Characteristics and Source of VOCs During O3 Pollution Between August to September, Langfang Development Zones

A total of 99 volatile organic compound(VOC) species were detected the Langfang development zones based on continuous monitoring using a ZF-PKU-1007 between August 25 and September 30, 2018. The concentrations, reactivity, and sources of VOCs were studied under different O3 concentrations using compositional analysis. The results showed that the average VOCs concentration during the research period was(75.17±38.67)×10-9, and was(112.33±30.96)×10-9, (66.25±34.84)×10-9 on pollution days and cleaning days, respectively(VOCs concentrations were 69.6% higher on pollution days). The contribution of VOCs species to the ozone formation potential(OFP) were ranked in the order aldehydes > aromatics > alkenes > alkanes. In the case of L·OH, the main contributions were from aromatics(30.0%) and alkenes(25.8%) on pollution days, while the contribution from aromatic alkenes(29.8%) was a slightly higher than aromatics(28.0%) on cleaning days. By applying the positive matrix factorization(PMF) model, five major VOCs sources were extracted, namely vehicle emissions(34.4%), solvent usage and evaporation(31.7%), the petrochemical industry(15.7%), combustion(11.1%), and plant emissions(7.9%). The contributions of solvent usage and evaporation and plant emission sources on pollution days were 13.1% and 1.2% higher than on cleaning days, respectively, which was likely due to relatively higher temperatures on these days. Therefore, vehicle emissions and solvent usage and evaporation should be priorities in VOCs control strategies for the Langfang development zones between August to September.

The role of pumpkin pulp extract carotenoids against mycotoxin damage in the blood brain barrier in vitro.

Some mycotoxins such as beauvericin (BEA), ochratoxin A (OTA), and zearalenone (ZEA) can cross the blood brain barrier, which is why we tested the anti-inflammatory action of a pumpkin carotenoid extract (from the pulp) against these mycotoxins and their combinations (OTA+ZEA and OTA+ZEA+BEA) on a blood brain barrier model with co-cultured ECV304 and C6 cells using an untargeted metabolomic approach. The cells were added with mycotoxins at a concentration of 100 nmol/L per mycotoxin and pumpkin carotenoid extract at 500 nmol/L. For control we used only vehicle solvent (cell control) or vehicle solvent with pumpkin extract (extract control). After two hours of exposure, samples were analysed with HPLC-ESI-QTOF-MS. Metabolites were identified against the Metlin database. The proinflammatory arachidonic acid metabolite eoxin (14,15-LTE4) showed lower abundance in ZEA and BEA+OTA+ZEA-treated cultures that also received the pumpkin extract than in cultures that were not treated with the extract. Another marker of inflammation, prostaglandin D2-glycerol ester, was only found in cultures treated with OTA+ZEA and BEA+OTA+ZEA but not in the ones that were also treated with the pumpkin extract. Furthermore, the concentration of the pumpkin extract metabolite dihydromorelloflavone significantly decreased in the presence of mycotoxins. In conclusion, the pumpkin extract showed protective activity against cellular inflammation triggered by mycotoxins thanks to the properties pertinent to flavonoids contained in the pulp.

Setting Time of Calcium Hydroxide from Indonesian Limestone Paste with Various Solvent Vehicle for Intracanal Medicament

Calcium hydroxide (Ca(OH)2 has been recently synthesized from natural Indonesian limestone to be used as an intracanal medicament for root canal infection. Ca(OH)2 is applied into the infected root canal in a non-setting paste form to release calcium and hydroxyl ions which elevates the pH and provide an antimicrobial effect to pathogenic bacteria. To form an injectable paste, Ca(OH)2 powder has to be mixed with a proper solvent to produce optimal consistency, ion dissociation, and maintain its property as a non-set material. Solvent is an important factor affecting ion dissociation and preserving its non-setting paste condition. The aim of this study is to synthesize Ca(OH)2 powder from Indonesian limestone, and evaluate the setting time of Ca(OH)2 paste from mixture of Ca(OH)2 powder synthesized from Indonesian limestone (limestone Ca(OH)2) with various solvent, to evaluate which solvent serve best to prevent the Ca(OH)2 paste from setting, to form an ideal paste be used as an intracanal medicament. This study consists of 5 groups (n=5); commercially Ca(OH)2 paste (Calcipex II) as positive control, Ca(OH)2 powder (Merck) + distilled water as negative control, limestone Ca(OH)2 powder + natrium carboxy methylcellulose (Na CMC) as group 1, limestone Ca(OH)2 powder + propylene glycol (PG) as group 2, and limestone Ca(OH)2 powder + polyethylene glycol (PEG) as group 3. Setting time evaluation was measured according to ISO 9917 by vicat needle in 37°C to mimic the physiological body condition. Results were analyzed by One Way Anova test and Post Hoc Tukey test. The result of this study showed that the setting time of Ca(OH)2 paste mixed with Na CMC solvent was 1:04 hours, PG 72:15 hours, and PEG did not harden until 7 days of observation. PEG is a hygroscopic high viscosity solvent, resulting in low and steady molecule interaction, thus prolonged its setting time. From this study it can be concluded that PEG inhibit Ca(OH)2 setting reaction up to 7 days and might be used as solvent for Ca(OH)2 paste as intracanal medicament.

The characteristics and source analysis of VOCs emissions at roadside: Assess the impact of ethanol-gasoline implementation

To research the effect of ethanol-gasoline on the VOCs emission from vehicles, two long-term roadside experiments were carried out to obtain the characteristics of VOCs emissions from vehicles at TEDA road in Tianjin. The Positive Matrix Factorization (PMF) source analysis model is used to analyze the VOCs at roadside and assess the impact of ethanol-gasoline implementation. The results show that the average VOCs concentration in the roadside environment was 45.67 ± 34.60 μg/m3 in the 2019 experiment. Alkanes, alkenes, halogenated hydrocarbons, alkynes, aromatic hydrocarbons and oxygen volatile organic compounds (OVOCs) accounted for 63.18%, 13.24%, 9.04%, 6.03%, 5.35% and 3.16%, respectively. Compared with the experiment in 2018, the concentration of m/p-xylene and benzene in the roadside environment showed a significant decrease. Five VOCs sources were identified, including gasoline vehicle exhaust emissions (27.46%), diesel vehicle exhaust emissions (23.70%), evaporative emission (22.67%), LPG/CNG vehicle emission (13.86%) and solvent usage (12.30%). The PMF analysis results of 2018 and 2019 showed that the contribution of gasoline vehicle exhaust emissions decreased by 8%, but the contribution rate of evaporative emissions increased by 6%. The implementation of ethanol-gasoline can reduce VOCs emissions from vehicle exhaust, however, the evaporative emissions of VOCs will increase. Evaporative emission from vehicles should be strictly controlled in the future.

Characteristics and health risks of benzene series and halocarbons near a typical chemical industrial park

Health risks of typical benzene series and halocarbons (BSHs) in a densely populated area near a large-scale chemical industrial park were investigated. Ambient and indoor air and tap water samples were collected in summer and winter; and the concentration characteristics, sources, and exposure risks of typical BSH species, including five benzene series (benzene, toluene, ethylbenzene, o-xylene, m,p-xylene) and five halocarbons (dichloromethane, trichloromethane, trichloroethylene, tetrachloromethane, and tetrachloroethylene), were analysed. The total mean concentrations of BSHs were 53.32 μg m−3, 36.29 μg m−3, and 26.88 μg L−1 in indoor air, ambient air, and tap water, respectively. Halocarbons dominated the total BSHs with concentrations relatively higher than those in many other industrial areas. Industrial solvent use, industrial processes, and vehicle exhaust emissions were the principal sources of BSHs in ambient air. The use of household products (e.g., detergents and pesticides) was the principal source of indoor BSHs. Inhalation is the primary human exposure route. Ingestion of drinking water was also an important exposure route but had less impact than inhalation. Lifetime non-cancer risks of individual and cumulative BSHs were below the threshold (HQ = 1), indicating no significant lifetime non-cancer risks in the study area. However, tetrachloromethane, benzene, trichloromethane, ethylbenzene, and trichloroethylene showed potential lifetime cancer risk. The cumulative lifetime cancer risks exceeded the tolerable benchmark (1 × 10−4), indicating a lifetime cancer risk of BSHs to residents near the chemical industry park. This study provides valuable information for the management of public health in chemical industrial parks.

The Role of Common Solvents against Pseudomonas aeruginosa-Induced Pathogenicity in a Murine Burn Site Infection Model.

ABSTRACTDimethyl sulfoxide (DMSO) and polyethylene glycols (PEGs) are frequently used as potent excipients in pharmaceutical formulations. However, these agents also have an interesting antimicrobial and anti-inflammatory profile that could interfere with the efficacy testing of anti-infective compounds when the latter are solubilized in DMSO or PEGs. Here, we demonstrate the antimicrobial and anti-inflammatory effects of DMSO-PEG400 in a murine Pseudomonas aeruginosa infection model, aiming to draw attention to the appropriate selection of solvents for difficult-to-solubilize anti-infectives.IMPORTANCE Our study demonstrates the antimicrobial and anti-inflammatory effects of the combination of DMSO and PEG400 against Pseudomonas aeruginosa in vitro and in vivo in a murine infection model of heightened intestinal permeability. The aim of this study is to draw attention to the appropriate selection of solvents for difficult-to-solubilize anti-infective compounds, to avoid interference with the assay or system tested. This is an extremely important consideration, since potential antimicrobial and anti-inflammatory effects of the solvent vehicle are detrimental to research studies on the efficacy of new anti-infective agents, given that the vehicle effect can mask the effect of the tested compounds. Our results can therefore be of great value to the scientific community, as they can guide researchers in the future to avoid this significant pitfall that can cost substantial amounts of money and valuable time during investigations of the effects of novel, difficult-to-solubilize antimicrobial compounds.

Dihydromyricetin Imbues Antiadipogenic Effects on 3T3-L1 Cells via Direct Interactions with 78-kDa Glucose-Regulated Protein.

Obesity is among the most serious public health problems worldwide, with few safe pharmaceutical interventions. Natural products have become an important source of potential anti-obesity therapeutics. Dihydromyricetin (DHM) exerts antidiabetic effects. The biochemical target of DHM, however, has been unknown. It is crucial to identify the biochemical target of DHM for elucidating its physiological function and therapeutic value. The objective of this study was to identify the biochemical target of DHM. An abundant antiadipogenic flavanonol was extracted from the herbal plant Ampelopsis grossedentata through bioassay-guided fractionation and characterized with high-resolution LC-MS and 1H and 13C nuclear magnetic resonance. Antiadipogenic experiments were done with mouse 3T3-L1 preadipocytes. A biochemical target of the chemical of interest was identified with drug affinity responsive target stability assay. Direct interactions between the chemical of interest and the protein target in vitro were predicted with molecular docking and subsequently confirmed with surface plasmon resonance. Expression levels of peroxisome proliferator-activated receptor γ (PPARγ), which is associated with 78-kDa glucose-regulated protein (GRP78), were measured with real-time qPCR. DHM was isolated, purified, and structurally characterized. Cellular studies showed that DHM notably reduced intracellular oil droplet formation in 3T3-L1 cells with a median effective concentration of 294 μM (i.e., 94μg/mL). DHM targeted the ATP binding site of GRP78, which is associated with adipogenesis. An equilibrium dissociation constant between DHM and GRP78 was 21.8μM. In 3T3-L1 cells upon treatment with DHM at 50 μM (i.e., 16μg/mL), the expression level of PPARγ was downregulated to 53.9% of the solvent vehicle control's level. DHM targets GRP78 in vitro. DHM is able to reduce lipid droplet formation in 3T3-L1 cells through a mode of action that is plausibly associated with direct interactions between GRP78 and DHM, which is a step forward in determining potential applications of DHM as an anti-obesity agent.

Positive Effects of Oral Antibiotic Administration in Murine Chronic Graft-Versus-Host Disease.

Chronic graft-versus-host disease (cGVHD) is one of the most frequent complications experienced after allogeneic hematopoietic stem cell transplantation. Reportedly, dysbiosis and severe damage to the microbiome are also closely associated with GVHD. Herein, we aimed to elucidate the positive and negative effects of the administration of various antibiotics in a murine model of cGVHD. For allogeneic bone marrow transplantation (allo-BMT), bone marrow from B10.D2 mice were transplanted in BALB/c mice to induce cGVHD. The cGVHD mice were orally administered ampicillin, gentamicin (GM), fradiomycin, vancomycin, or the solvent vehicle (control group). Among the antibiotic-treated mice, the systemic cGVHD phenotypes and ocular cGVHD manifestations were suppressed significantly in GM-treated mice compared to that in control mice. Inflammatory cell infiltration and fibrosis in cGVHD-targeted organs were significantly attenuated in GM-treated mice. Although regulatory T cells were retained at greater levels in GM-treated mice, there were significantly fewer Th17 cells and interleukin (IL)-6-producing macrophages in cGVHD-targeted organs in these mice. Collectively, our results revealed that orally administered GM may exert positive effects in a cGVHD mouse model.

Behaviour of Functionalized Multi-Walled Carbon Nanotubes (MWCNTs) as Conductive Nano-Ink in Isopropyl Alcohol Solvent

This paper presents the preparation of dispersion solutions for conductive nano-ink for inkjet printers which included filler, vehicle (solvent) and additive. For fillers, multi-walled carbon nanotubes (MWCNTs) encounter major problem such as poor dispersion resulting in agglomeration, sedimentation and unstable solution, causing nozzle clogging. MWCNTs consist of two main functional groups, namely carboxyl (−COOH) and hydroxyl (−OH) groups dispersed in isopropyl alcohol (IPA) solvent. Each functional group showed good performance as a filler after dispersing in IPA. However, MWCNT-OH has better conductivity with lower resistance of 11.3 kΩ compared to MWCNT-COOH of 15.1 kΩ. It is important for MWCNTs to have good behaviour as a filler to produce stable and high conductivity nano-ink with resistance range in kilo-ohms (kΩ). In addition, dispersing solvent is also important to ensure dispersion stability as well as maintain the performance of the filler.

Chaihu Guizhi decoction produces antidepressant-like effects via sirt1-p53 signaling pathway

To investigate the mechanism of the antidepressant-like effects of Chaihu Guizhi decoction (CGD). Chaihu Guizhi decoction at the daily dose of 17 g/kg and solvent vehicle were administered by gavage in 12 and 14 male C57BL/6J mice for 7 consecutive days, respectively. Forced swimming test (FST), elevated plus maze (EPM) test, open field test (OFT) and novelty-suppressed feeding test (NSF) were performed to assess the depression- and anxiety-like behaviors and motor ability of the mice. We further used chronic social defeat stress (CSDS) and social interaction test to evaluate the antidepressant-like effects of CGD in comparison with the solvent vehicle. Western blotting and RT-qPCR were performed to detect the expressions of sirt1, p53, acetylated p53, and the neuron plasticity-related genes including synapsin I (Syn1), Rab4B, SNAP25 and tubulin beta4b in the hippocampus of the mice. In FST, the immobility time of CGDtreated mice was decreased significantly (P < 0.05); no significant differences were found in the performances in EPM, NSF and OFT tests between the two groups. In social interaction test, the mouse models of CSDS treated with CGD showed significantly increased time in the interaction zone (P < 0.05). Compared with those in the vehicle group, the CGD-treated mouse models exhibited significantly increased protein level of SIRT1 and decreased p53 acetylation (P < 0.05) with up-regulated synapsin I mRNA expression in the hippocampus (P < 0.05); no significant difference were found in Rab (P=0.813), SNAP (P=0.820), or Tubb mRNA expressions (P=0.864) between the two groups. CGD produces antidepressant-like effects in mice possibly through the sirt1-p53 signaling pathway and synaptic plasticity.

Volatile Organic Compounds Monitored Online at Three Photochemical Assessment Monitoring Stations in the Pearl River Delta (PRD) Region during Summer 2016: Sources and Emission Areas

Volatile organic compounds (VOCs) were monitored online at three photochemical assessment monitoring stations (MDS, WQS and HGS) in the Pearl River Delta region during the summer of 2016. Measured levels of VOCs at the MDS, WQS and HGS sites were 34.78, 8.54 and 8.47 ppbv, respectively, with aromatics and alkenes as major ozone precursors and aromatics as major precursors to secondary organic aerosol (SOA). The positive matrix factorization (PMF) model revealed that VOCs at the sites mainly came from vehicle exhaust, petrochemical industry, and solvent use. Vehicle exhaust and industrial processes losses contributed most to ozone formation potentials (OFP) of VOCs, while industrial processes losses contributed most to SOA formation potentials of VOCs. Potential source contribution function (PSCF) analysis revealed a north-south distribution for source regions of aromatics occurring at MDS with emission sources in Guangzhou mainly centered in the Guangzhou central districts, and source regions of aromatics at WQS showed an east-west distribution across Huizhou, Dongguan and east of Guangzhou, while that at HGS showed a south-north distribution across Guangzhou, Foshan, Zhaoqing and Yangjiang. This study demonstrates that multi-point high time resolution data can help resolve emission sources and locate emission areas of important ozone and SOA precursors.

Characteristics and Source Apportionment of Ambient VOCs in Spring in Liuzhou

The objective was to investigate the characteristics and sources of ambient volatile organic compounds (VOCs) in the karst region in southwestern China. We monitored atmospheric VOCs in Liuzhou by the GC955 VOCs Online Monitoring System and analyzed the pollution characteristics, ozone formation potential (OFP), aerosol formation potential (AFP), and the positive matrix factorization (PMF) model in March 2019. The results show that ① 50 kinds of VOC components were detected during the supervised period, with an average daily concentration of 25.52×10-9 mol·mol-1, which was composed of alkanes (56.08%), alkenes (19.63%), alkynes (14.25%), and aromatics (10.04%), respectively. ② The concentration of VOCs was lower during the day and higher at night, with the highest value at 23:00. The VOC concentration was low in daytime and high at night. The peak value of VOCs with regard to diurnal variation was correlated with the time of morning and the evening traffic peak and may be influenced by various factors. ③ The contribution of alkenes, aromatics, and alkanes to OFP was 44.30%, 33.03%, and 19.96%, respectively. This indicates that the control of aromatic and olefin should prioritize alkanes. In addition, Liuzhou city is in the VOC sensitive area of O3 generation, and the reduction of VOCs had a controlling effect on O3 generation. ④ The contribution of aromatic hydrocarbons to AFP was up to 95.27%. Therefore, the improvement and control of the processes in motor vehicle exhaust emissions, solvent use, and the automobile industry and the chemical industry could effectively suppress ozone and haze pollution. ⑤ The emission sources of VOCs in spring were mainly industrial emission sources (28.34%), motor vehicle sources (25.47%), combustion sources (24.37%), solvent sources (13.28%), and plant emission sources (8.54%), respectively. This indicates that the control of industrial emission sources, motor vehicle sources, and combustion sources is the main way to control VOC pollution in Liuzhou City. Meanwhile, the olefin and aromatic hydrocarbons emitted by these emission sources should be mainly considered.

Source apportionment of volatile organic compounds: Implications to reactivity, ozone formation, and secondary organic aerosol potential

Volatile organic compounds (VOCs) are important contributors to atmospheric chemical reactivity rate (LOH), ozone formation potential (OFP), and secondary organic aerosol formation potential (SOAP). The purpose of this study was to determine the contributions of different VOC sources to LOH, OFP, and SOAP using positive matrix factorization (PMF) model. Hourly observation of ambient VOCs at a megacity of Central China was conducted for one month in winter. The LOH, OFP, and SOAP of VOC species were firstly estimated. The PMF model was then used to apportion their sources. Five VOC sources including solvent usage, gasoline evaporation, combustion sources, vehicle emissions, and industrial sources were apportioned with their average contributions of 11.6%, 14.2%, 39.0%, 22.5%, and 12.6%, respectively. Industrial sources were the highest contributors to the LOH and SOAP with average contributions of 32.2% and 32.8%, respectively, while vehicle emissions contributed most to the OFP (27.8%). This study highlighted that the VOCs and ozone pollution control should give priority to the reactivity (OFP and SOAP) based strategies rather than concentration contribution-based strategies.

Evolution and Evaluation of O3 and VOCs in Zhengzhou During the National Traditional Games of Ethnic Minorities Period

During the National Traditional Games of Ethnic Minorities (NTGEM) 2019, air quality in Zhengzhou was analyzed to evaluate the impact of pollution prevention and control measures on Zhengzhou. Ground-observed meteorological and pollutant data as well as the chemical compositions of volatile organic compounds (VOCs) were investigated. The results showed that the six parameters of pollutants in the safeguard period in 2019 indicated a downward trend as compared with that during the same time in 2018, and the average concentrations of PM2.5 and PM10 were decreased by 16.2% and 25.1%, respectively. However, the average concentration of O3 was only reduced by 3.7%. The daily proportions of primary pollutants of O3 increased to 90% during the NTGEM, and the ozone pollution was severe in this period. Meanwhile, the concentration of total volatile organic compounds (TVOCs) in the safeguard period was 26.21×10-9, which was significantly lower than that during the historical period. Six emission sources of the VOCs were identified using PMF model, including vehicle exhaust (28%), LPG evaporation (21%), combustion source (16%), industrial emissions (15%), solvent utilization (15%), and biogenic VOCs (5%). During the NTGEM period, the control of combustion sources and industrial sources was evident.

Occurrence of indicator bacteria and pathogens in the waters of the noyyal river near its source and downstream in coimbatore district

Water, the bloodstream of the biosphere, also acts as a sink, solvent and transport vehicle for domestic, agricultural and industrial waste, causing pollution. The Noyyal River, a tributary of the River Cauvery, was once the lifeline of Coimbatore, but is now being threatened by pollution from various sources. Assessments of microbiological water quality have focused on the presence of Fecal Indicator Bacteria, which indicate that a contamination pathway exists between a bacterial source and the water supply, serving as a route for pathogen entry. Water samples from seven sites (Kooduthurai, Madakkadu,Thombilipalayam, Alandurai, Mathampatti, Perur and Aathuppalam) along the Noyyal, were analyzed for various microbiological characteristics. The results indicated that the river was relatively unpolluted upstream near its sources, but is progressively polluted on moving further downstream towardsCoimbatore city. Levels of Total Heterotrophic Bacteria, indicators such as Enterobacteriaceae, Total Coliforms, Fecal Coliforms (FC), Fecal Streptococci (FS), pathogens like Salmonella sp., Shigella sp., and Vibrio sp. were elevated at downstream sampling sites. Evaluation of the FC:FS ratio revealed that, the water was unfit for drinking at almost all the downstream sampling stations, and could have limited use for irrigation. The release of fecal microorganisms and pathogens from the sediments to the water column could be a major source of bacterial loading. Non-point sources were identified as the major contributors of contaminants. Regular monitoring of the river water and sediment, amelioration of point / non-pointsources of pollution, and speedy implementation of remedial measures, may restore this stretch of the Noyyal River to its former pristine state.

The Effect of an Intramembrane Light-Actuator on the Dynamics of Phospholipids in Model Membranes and Intact Cells.

The noncovalent intercalation of amphiphilic molecules in the lipid membrane can be exploited to modulate efficiently the physical status of the membrane. Such effects are largely employed in a range of applications, spanning from drug-delivery to therapeutics. In this context, we have very recently developed an intramembrane photo-actuator consisting of an amphiphilic azobenzene molecule, namely ZIAPIN2. The selective photo-isomerization occurring in the lipid bilayer induces a photo-triggered change in the membrane thickness and capacitance, eventually permitting to evoke light-induced neuronal firing both in vitro and in vivo. Here, we present a study on the dynamical perturbation in the lipid membrane caused by ZIAPIN2 and its vehicle solvent, dimethyl sulfoxide. Effects on the dynamics occurring in the picosecond time range and at the molecular level are probed using quasi-elastic neutron scattering. By coupling experiments carried out both on model membranes and intact cells, we found that DMSO leads to a general retardation of the dynamics within a more dynamically ordered landscape, a result that we attribute to the dehydration at the interface. On the other hand, ZIAPIN2 partitioning produces a general softening of the bilayer owing to its interaction with the lipids. These data are in agreement with our recent studies, which indicate that the efficacy of ZIAPIN2 in triggering cellular signalling stems from its ability to mechanically perturb the bilayer as a whole, by forming light-sensitive membrane spanning dimers.

Metabolic Acidosis – Not Always the Medication to Blame

Background: Metabolic acidosis is a clinical disturbance characterized by an increase in acidity of plasma. Metabolic acidosis is considered a sign of an underlying disease. Identification of this underlying condition is the cornerstone to initiate appropriate management. Metabolic acidosis is typically classified as having a normal anion gap (AG) (i.e. non-AG) or a high AG. An increase in the AG can result from either a decrease in unmeasured cations (e.g. hypokalemia, hypocalcemia, hypomagnesemia) or an increase in unmeasured anions (e.g. hyperphosphatemia, high albumin levels). Case: A 46-year-old male with a history of type 2 diabetes mellitus, recently started on liraglutide. He was presented to the emergency department with 4 days of nausea, vomiting, and diarrhea and one day of lethargy. He appeared to be dyspneic upon presentation, and he was initially placed on noninvasive positive pressure ventilation. The arterial blood gases (ABG), however, showed metabolic acidosis. After admission and resolution of diabetic ketoacidosis, his bicarbonate was still low, and a sodium bicarbonate drip was begun. Correction only had occurred after stopping liraglutide. Conclusion: Vehicle solvent such as propylene glycol should be considered in the differential diagnosis of high anion gap metabolic acidosis, and its level should be measured in intractable cases.

OR03-01 Effects Of Alpha-emitting Meta-211At-astato-benzylguanidine (211At-MABG) Compared To 131I-meta-iodobenzylguanidine (131I-MIBG) on Tumor Growth Suppression in a Pheochromocytoma Mouse Model

Objectives: Given the limited treatment approaches currently available for patients with metastatic pheochromocytoma and paraganglioma (PPGL), new effective approaches are being sought. The radioisotope approach using 131I-meta-iodobenzylguanidine (131I-MIBG) has limited survival benefits in metastatic PPGL but is currently considered one of the standard therapeutic approaches. In theory, the alpha-emitting radiopharmaceutical meta-211At-astato-benzylguanidine (211At-MABG) could be a very effective targeted treatment for metastatic PPGL. However, this possibility has not been evaluated. Therefore, the purpose of this study was to evaluate the tumor growth suppression effects of 211At-MABG compared to 131I-MIBG using a PC-12 mouse pheochromocytoma model. Methods: Rat pheochromocytoma (PC-12) cells were subcutaneously inoculated into male BALB/c nu/nu nude mice. When tumor volumes reached approximately 300 mm3, mice bearing PC-12 tumors received intravenously either 1.11 MBq of 211At-MABG (n=6), 31 MBq of 131I-MIBG (n=3) or vehicle solvent (n = 6). The tumor volume was measured 3 times per week for 2 weeks. The tumor volume was compared among the three groups. Results: At 14 days, the tumor volumes significantly increased in the control group (328.82±83.65 to 3568.83±693.23 mm3, P<0.001). In contrast, there were no significant changes in tumor volumes in the 211At-MABG group (284.65±56.77 to 274.3±87.95 mm3, P=0.616) and 131I-MIBG group (484.40±46.25 to 323.93±127.27 mm3, P=0.084). The 211At-MABG group showed significantly lower percentage change in tumor volume than did the control group (-5.0±15.99 vs. 1043.83±320.79%, P<0.001), and 131I-MIBG group also showed significant volume reduction rate compared to that of the control group (-34.33±21.39 vs. 1043.82±320.79%, P<0.001). There was no significant difference in percentage tumor volume changes between the 211At-MABG and 131I-MIBG groups (P=0.052). Conclusion: At 14 days after radiopharmaceutical administration, 211At-MABG produced significant tumor volume reduction as compared to that in the control group and to that associated with 131I-MIBG, which is considered one of the current treatment options. Therefore, 211At-MABG may have future clinical applications for the treatment of metastatic pheochromocytoma and paraganglioma.

Source apportionment of biogenic and anthropogenic VOCs in Bolu plateau

Total of 69 volatile organic compounds (VOCs) including both biogenic (isoprene, monoterpenes and oxygenated compounds) and anthropogenic ones were investigated in Bolu plateau by passive sampling technique. The main objective of this study was to determine spatial distributions, seasonal variations and possible sources for a wide variety of VOCs. Two-week passive sampling campaigns were performed in the winter and summer of 2017. Anthropogenic VOCs were predominant with a high percentage of contribution, 91% and 69% for winter and summer, respectively. Relatively higher concentrations of biogenic VOCs during the summer campaign were found to be related to higher solar intensity, temperature and amount of broad-leaved tree species. Benzaldehyde, toluene, phenol, benzene, hexane, decanal, benzothiazole, dodecane and acetophenone were anthropogenic VOCs with higher concentrations. Among biogenic VOCs, hexanal, alpha-pinene and limonene were found to be in higher concentrations. Spatial distribution maps were drawn for each VOC. Elevated concentrations of VOCs around the city center and major roads indicate that emissions from domestic heating activities and vehicular emissions can be significant sources of VOCs. The results were also supported by Positive Matrix Factorization (PMF) analyses and G-score distribution maps. Solvent evaporation, wood-coal combustion, biogenic emissions (pine, grain, grass), city atmosphere (styrene emissions from plastic production), biogenic (hornbeam, pine, juniper) and vehicle emissions were the identified as the primary VOC sources in Bolu plateau, contributing 31%, 22%, 8.0%, 8.0%, 13%, and 18%, respectively to the total VOC concentrations.

Anode ink formulation for a fully printed flexible fuel cell stack

In fuel cells the underlying reactions take place at the catalyst layers composed of materials favoring the desired electrochemical reactions. This paper introduces a formulation process for a catalyst inkjet ink used as an anode for a fully printed flexible fuel cell stack. The optimal ink formulation was 2.5 wt% of carbon–platinum–ruthenium mixture with 0.5% Nafion concentration in a diacetone alcohol solvent vehicle. The best jetting performance was achieved when 1 wt% binder was included in the ink formulation. Anodes with resistivity of approximately 0.1 Ω cm were inkjet printed, which is close to the commercial anode resistivity of 0.05 Ω cm. The anodes were used in fuel cell stacks that were prepared by utilizing only printing methods. The best five-cell-air-breathing stack showed an open circuit potential under H2/air conditions of 3.4 V. The peak power of this stack was 120 µW cm−2 at 1.75 V, with a resistance obtained from potentiostatic impedance analysis of 295 Ohm cm2. The printed electrodes showed a performance suitable for low-performance solutions, such as powering single-use sensors.