Secondary OA Research Articles

Chemical characterization of fine particulate matter in Changzhou, China, and source apportionment with offline aerosol mass spectrometry

Abstract. Knowledge of aerosol chemistry in densely populated regions is critical for effective reduction of air pollution, while such studies have not been conducted in Changzhou, an important manufacturing base and populated city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particulate matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in this city. A suite of analytical techniques was employed to measure the organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosol (WSOA). The average PM2.5 concentration was found to be 108.3 µg m−3, and all identified species were able to reconstruct ∼ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (∼ 52.1 %), with SO42−, NO3−, and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating that traffic emissions were more important than stationary sources. OC and EC correlated well with each other and the highest OC ∕ EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondary and primary ones. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to ∼ 5.0 % of PM2.5 during winter. PAH concentrations were also high in winter (140.25 ng m−3), which were predominated by median/high molecular weight PAHs with five and six rings. The organic matter including both water-soluble and water-insoluble species occupied ∼ 21.5 % of the PM2.5 mass. SP-AMS determined that the WSOA had average atomic oxygen-to-carbon (O ∕ C), hydrogen-to-carbon (H ∕ C), nitrogen-to-carbon (N ∕ C), and organic matter-to-organic carbon (OM ∕ OC) ratios of 0.54, 1.69, 0.11, and 1.99, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized oxygenated OA) and two primary OA (POA) factors (a nitrogen-enriched hydrocarbon-like traffic OA and a local primary OA likely including species from cooking, coal combustion, etc.). On average, the POA contribution outweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions in the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species are likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.

Primary and secondary aerosols in Beijing in winter: sources, variations and processes

Abstract. Winter has the worst air pollution of the year in the megacity of Beijing. Despite extensive winter studies in recent years, our knowledge of the sources, formation mechanisms and evolution of aerosol particles is not complete. Here we have a comprehensive characterization of the sources, variations and processes of submicron aerosols that were measured by an Aerodyne high-resolution aerosol mass spectrometer from 17 December 2013 to 17 January 2014 along with offline filter analysis by gas chromatography/mass spectrometry. Our results suggest that submicron aerosols composition was generally similar across the winter of different years and was mainly composed of organics (60 %), sulfate (15 %) and nitrate (11 %). Positive matrix factorization of high- and unit-mass resolution spectra identified four primary organic aerosol (POA) factors from traffic, cooking, biomass burning (BBOA) and coal combustion (CCOA) emissions as well as two secondary OA (SOA) factors. POA dominated OA, on average accounting for 56 %, with CCOA being the largest contributor (20 %). Both CCOA and BBOA showed distinct polycyclic aromatic hydrocarbons (PAHs) spectral signatures, indicating that PAHs in winter were mainly from coal combustion (66 %) and biomass burning emissions (18 %). BBOA was highly correlated with levoglucosan, a tracer compound for biomass burning (r2 = 0.93), and made a considerable contribution to OA in winter (9 %). An aqueous-phase-processed SOA (aq-OOA) that was strongly correlated with particle liquid water content, sulfate and S-containing ions (e.g. CH2SO2+) was identified. On average aq-OOA contributed 12 % to the total OA and played a dominant role in increasing oxidation degrees of OA at high RH levels (> 50 %). Our results illustrate that aqueous-phase processing can enhance SOA production and oxidation states of OA as well in winter. Further episode analyses highlighted the significant impacts of meteorological parameters on aerosol composition, size distributions, oxidation states of OA and evolutionary processes of secondary aerosols.

Vertical force analysis in dogs with hip osteoarthritis undergoing treatment with chondroprotectors

This study was aimed at evaluating vertical forces generated during locomotion in dogs affected with hiposteoarthritis (OA) submitted to chondroprotective treatment with chondroitin sulphate and lucosamine(CS-GLU). Eighteen dysplastic dogs suffering from secondary bilateral hip OA and treated with CS-GLU(200mg and 300mg/10kg/SID respectively) for 60 days (treated group), and 18 lameness free dogs withnormal hip joints (healthy group) were evaluated. A pressure sensitive walkway was used to measure peakvertical force (PVF), vertical impulse (VI) and stance phase (SP) duration. Data collection was performed prior to and within 30 and 60 days of treatment (treated group), or on a single occasion (healthy group). Longitudinal and intergroup comparisons were made using repeated measures ANOVA followed by the Tukey post-hoc test and the unpaired t-test respectively, with a significance level of 5% (p<0.05). Mean peak vertical force did not differ significantly within the treated group. However, mean PVF and VI were lower in the treated compared to the control group. A slight increase in mean VI was documented in one treated limbat time points 30 and 60. Results of this study suggest hip OA leads to decreased weight bearing and treatmentwith CS-GLU does not improve PVF in the short term.

Chemical composition, sources and evolution processes of aerosol at an urban site in Yangtze River Delta, China during wintertime

To investigate the composition, sources and evolution processes of submicron aerosol during wintertime, a field experiment was conducted during December 1–31, 2013 in urban Nanjing, a megacity in Yangtze River Delta of China. Non-refractory submicron aerosol (NR-PM1) species were measured with an Aerodyne Aerosol Chemical Speciation Monitor. NR-PM1 is dominated by secondary inorganic aerosol (55%) and organic aerosol (OA, 42%) during haze periods. Six OA components were identified by positive matrix factorization of the OA mass spectra. The hydrocarbon-like OA and cooking-related OA represent the local traffic and cooking sources, respectively. A highly oxidized factor related to biomass burning OA accounted for 15% of the total OA mass during haze periods. Three types of oxygenated OA (OOA), i.e., a less-oxidized OOA (LO-OOA), a more-oxidized OOA (MO-OOA), and a low-volatility OOA (LV-OOA), were identified. LO-OOA is likely associated with fresh urban secondary OA. MO-OOA likely represents photochemical products showing a similar diurnal cycle to nitrate with a pronounced noon peak. LV-OOA appears to be a more oxidized factor with a pronounced noon peak. The OA composition is dominated by secondary species, especially during haze events. LO-OOA, MO-OOA and LV-OOA on average account for 11%, (18%), 24% (21%) and 23% (18%) of the total OA mass for the haze (clean) periods respectively. Analysis of meteorological influence suggested that regional transport from the northern and southeastern areas of the city is responsible for large secondary and low-volatility aerosol formation.

Mapping articular cartilage biomechanical properties of normal and osteoarthritis mice using indentation

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A254 could be a relative increase in trabecular bone volume, which decrease in advance OA. For the tibias, only the SMI was increased in the ACLT knees versus the controls. It might be that 12 weeks is not sufficient time to detect OA trabecular bone microarchitecture changes in the tibia after the Pond-Nuki surgically induced secondary OA in the canine model. This study quantitatively analyzed the trabecular bone in the anterior cruciate ligament transection (ACLT) Pond-Nuki dog model. The results may help establish the standard characteristics of the knee joint trabecular bone microarchitecture upon development of OA, and to provide a greater understanding of OA from the clinical viewpoint and to aid in its treatment. Figure 1. showing 3D BMD color maps for the control femur (A) and tibia (B) and the ACLT femur (B) and tibia (D). The ACLT femur (B) shows lower BMD than the control (A). 391 MAPPING ARTICULAR CARTILAGE BIOMECHANICAL PROPERTIES OF NORMAL AND OSTEOARTHRITIS MICE USING INDENTATION J.-F. Lavoie yz, S. Sim yx, E. Quenneville x, M. Garon x, A. Moreau kz, M.D. Bushmann y, C.E. Aubin yz. y Polytechnique Montreal, Montreal, QC, Canada; z Sainte-Justine Univ. Hosp. Ctr., Montreal, QC, Canada; xBiomomentum, Laval, QC, Canada; k Faculty of Med., Dept of Biochemistry and Dept of Stomatology, Univ. of Montreal, Montreal, QC,

Correction of an inflammatory process with an interleukin-1 inhibitor in the combination treatment of secondary osteoarthritis in the presence of comorbid condition

To enhance the efficiency of treatment in patients with secondary osteoarthritis (ОА) in the presence of comorbid condition, by using an interleukin-1 inhibitor (IL-1i) and laser therapy (LT). A total of 248 patients aged 38 to 65 years with RA and secondary OA who had predominantly Stage II in accordance with the Disease Activity Score 28 (DAS28) were examined. According to the received therapy, the patients were divided into 4 groups: 1) IL-1i + LT + mrthotrexate (MT); 2) IL-1i + MT; 3) LT + MT; 4) MT. The efficiency of treatment was evaluated from changes in the KOOS (Knee injury and Osteoarthritis Outcome Score), DAS 28, IL-1, and cartilage oligomeric matrix protein (COMP) 6 months later. There were statistically significant functional improvements in KOOS and DAS28 in Groups 1 and 2 patients with secondary OA in RA. Clinical efficacy was confirmed by positive changes in serum IL-1 and COMP levels. Incorporation of an IL-1i into a therapy regimen for secondary OA in RA patients during basic therapy could not only improve the functional status of patients, but also decrease activity of the underlying disease according to the DAS 28.

THU0217 The Aftereffect of the Use of the Inhibitor of Interleukin-1 in Complex Therapy of Secondary Osteoarthritis of the Knee in Patients with Rheumatoid Arthritis

BackgroundNumerous studies have proved the advantageous aftereffect of the use of inhibitor of interleukin-1 in the therapy of patients with OA.ObjectivesThe aim of the study was to estimate the aftereffect...

SAT0450 Efficacy of Hydroxychloroquine in the Treatment of Symptomatic Knee Osteoarthritis in Older Adults: A Randomized Placebo-Controlled Trial

BackgroundOsteoarthritis (OA), particularly knee OA, is one of the most common causes of pain and disability in older people. Inflammation has been implicated in the pathogenesis of OA. Antimalarial agents...

High abundances of oxalic, azelaic, and glyoxylic acids and methylglyoxal in the open ocean with high biological activity: Implication for secondary OA formation from isoprene

AbstractAtmospheric dicarboxylic acids (DCA) are a ubiquitous water‐soluble component of secondary organic aerosols (SOA), which can act as cloud condensation nuclei (CCN), affecting the Earth's climate. Despite the high abundances of oxalic acid and related compounds in the marine aerosols, there is no consensus on what controls their distributions over the open ocean. Marine biological productivity could play a role in the production of DCA, but there is no substantial evidence to support this hypothesis. Here we present latitudinal distributions of DCA, oxoacids and α‐dicarbonyls in the marine aerosols from the remote Pacific. Their concentrations were found several times higher in more biologically influenced aerosols (MBA) than less biologically influenced aerosols. We propose isoprene and unsaturated fatty acids as sources of DCA as inferred from significantly higher abundances of isoprene‐SOA tracers and azelaic acid in MBA. These results have implications toward the reassessment of climate forcing feedbacks of marine‐derived SOA.

Characterization of submicron aerosols during a month of serious pollution in Beijing, 2013

Abstract. In January 2013, Beijing experienced several serious haze events. To achieve a better understanding of the characteristics, sources and processes of aerosols during this month, an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was deployed at an urban site between 1 January and 1 February 2013 to obtain the size-resolved chemical composition of non-refractory submicron particles (NR-PM1). During this period, the mean measured NR-PM1 mass concentration was 89.3 ± 85.6 μg m−3, and it peaked at 423 μg m−3. Positive matrix factorization (PMF) differentiated the organic aerosol into five components, including a highly oxidized, low-volatility oxygenated organic aerosol (LV-OOA), a less oxidized, semi-volatile oxygenated OA (SV-OOA), a coal combustion OA (CCOA), a cooking-related OA (COA), and a hydrocarbon-like OA (HOA), which on average accounted for 28%, 26%, 15%, 20% and 11% of the total organic mass, respectively. A detailed comparison between the polluted days and unpolluted days found many interesting results. First, the organic fraction was the most important NR-PM1 species during the unpolluted days (58%), while inorganic species were dominant on polluted days (59%). The OA composition also experienced a significant change; it was dominated by primary OA (POA), including COA, HOA and CCOA, on unpolluted days. The contribution of secondary OA (SOA) increased from 35% to 63% between unpolluted and polluted days. Second, meteorological effects played an important role in the heavy pollution in this month and differed significantly between the two types of days. The temperature and relative humidity (RH) were all increased on polluted days and the wind speed and air pressure were decreased. Third, the diurnal variation trend in NR-PM1 species and OA components showed some differences between the two types of days, and the OA was more highly oxidized on polluted days. Fourth, the effects of air masses were significantly different between the two types of days; air was mainly transported from contaminated areas on the polluted days. The comparison also found that the aerosol was more acidic on polluted days. Additionally, the variation trends of the mass concentration and mass fractions of NR-PM1 species and OA components were more dramatic when the NR-PM1 mass loading was at a higher level. The serious pollution observed in this month can be attributed to the synergy of unfavorable meteorological factors, the transport of air masses from high-pollution areas, emission by local sources, and other factors.

AB0804 Experience of educational programs for physicians in diagnosis and treatment of osteoporosis in kazan (russia)

BackgroundOsteoporosis is a serious and badly diagnosed problem for doctors in various specialties.ObjectivesTo evaluate the effectiveness of educational activities for general practitioners (GP), internists, neurologists in osteoporosis (OP) detection.MethodsThe educational...

Idiopathic hand osteoarthritis vs haemochromatosis arthropathy--a clinical, functional and radiographic study

Haemochromatosis arthropathy is a secondary OA and the most frequent and earliest clinical presentation of hereditary haemochromatosis (HH). The aim of this study was to perform a direct clinical, functional and radiographic comparison with idiopathic hand OA (HOA) to unravel important differences between these clinical entities. In total, 299 patients (141 with HH arthropathy of the hands and 158 patients with idiopathic HOA) were recruited. Structured clinical assessment including hand function tests, as well as hand radiographs with scoring according to Kellgren-Lawrence, were carried out in all patients. HH arthropathy and HOA differed significantly: patients with HH arthropathy were younger and predominantly male as compared with HOA. In males but not females, HH arthropathy led to an earlier start of symptoms than in HOA. Patients with HOA had more tender joints and worse hand function than patients with HH arthropathy, although subjective measures of joint pain and function were similar. MCP and wrist joint involvement was more frequent and severe in HH arthropathy, while HOA patients more frequently had degenerative changes in the first CMC as well as PIP and DIP joints. HH arthropathy and idiopathic HOA differ significantly in terms of epidemiology, localization, severity of symptoms and radiographic changes.

Effects of Passive Upper Extremity Joint Mobilization on Pain Sensitivity and Function in Participants With Secondary Carpometacarpal Osteoarthritis: A Case Series

ObjectiveThe purpose of this case series is to report on the effects of passive joint mobilization (PJM) of the shoulder, elbow, and wrist on pain intensity, pain sensitivity, and function in elderly participants with secondary carpometacarpal osteoarthritis (CMC OA). MethodsFifteen inpatients from the Department of Physical Therapy, Residenze Sanitarie Assistenziali, Collegno (Italy), with secondary CMC OA (70-90 years old) were included in this study. All patients received PJM of the dominant arm (shoulder, elbow, and wrist) for 4 sessions for 2 weeks. Pain severity was measured by visual analog scale, and pain sensitivity was measured with pressure pain threshold (PPT) at CMC joint, at the tubercle of the scaphoid bone, and at the unciform apophysis of the hamate bone. Tip and tripod pinch strength were measured by a pinch gauge. ResultsPassive joint mobilization reduced pain severity after the first follow-up by 30%, in addition to increased PPT by 13% in the hamate bone. Strength was enhanced after treatment. Tripod pinch increased by 18% in the dominant hand after treatment. ConclusionsThis case series provides preliminary evidence that PJM of upper extremity joints diminished pain and may increase PPT tip and tripod pinch in some participants with secondary CMC OA.

Ten-year follow-up of SpA-related oligoarthritis involving the knee: the presence of psoriasis but not HLA-B27 or baseline MRI bone oedema predicts outcome

Bone marrow oedema (BMO) and HLA-B27 are poor prognostic factors in axial SpA, and psoriasis is a poor prognostic factor in small-joint polyarthropathy. The aim of this study was to investigate the influence of HLA-B27, MRI BMO and psoriasis on long-term outcomes in early SpA-related knee joint oligoarthritis. Patients with SpA-related oligoarthritis with knee involvement were recruited. Baseline assessment included ESSG criteria, RF, HLA-B27 and MRI. The degree of MRI BMO was determined on fat-suppression sequences and scored using the whole-organ magnetic resonance imaging score (WORMS) (range 0-45). Patients were treated at the discretion of their rheumatologist and followed up for 10 years. Outcome assessments included joint counts, functional and symptomatic questionnaire, CRP and radiographic assessment for OA. Forty-four patients were recruited [mean age 32 years (range 15-59 years), 70% male] with a mean disease duration at baseline of 9.75 months (1-48 months). Twenty-six (59%) patients (mean age 43 years, 65% male) returned for follow-up after a mean of 10 years (range 8.4-12.6 years). Ten (38%) patients had persistent clinical synovitis and 31% of knees had secondary radiographic OA. Global outcome was poor/very poor in 69% of cases. The only factor predicting outcome at 10 years was psoriasis, but neither HLA-B27 nor BMO. PsA patients had significantly worse global outcome compared with ReA (P = 0.036), and significantly worse symptomatic (P = 0.001) and functional (P = 0.001) outcome compared with other subtypes. SpA-related knee joint oligoarthritis has significant long-term clinical and radiological morbidity despite standard treatments. HLA-B27 and MRI BMO were not predictors of poor outcome as they are in axial SpA; however, the presence of psoriasis predicted significantly worse outcome.

Understanding atmospheric organic aerosols via factor analysis of aerosol mass spectrometry: a review

Organic species are an important but poorly characterized constituent of airborne particulate matter. A quantitative understanding of the organic fraction of particles (organic aerosol, OA) is necessary to reduce some of the largest uncertainties that confound the assessment of the radiative forcing of climate and air quality management policies. In recent years, aerosol mass spectrometry has been increasingly relied upon for highly time-resolved characterization of OA chemistry and for elucidation of aerosol sources and lifecycle processes. Aerodyne aerosol mass spectrometers (AMS) are particularly widely used, because of their ability to quantitatively characterize the size-resolved composition of submicron particles (PM1). AMS report the bulk composition and temporal variations of OA in the form of ensemble mass spectra (MS) acquired over short time intervals. Because each MS represents the linear superposition of the spectra of individual components weighed by their concentrations, multivariate factor analysis of the MS matrix has proved effective at retrieving OA factors that offer a quantitative and simplified description of the thousands of individual organic species. The sum of the factors accounts for nearly 100% of the OA mass and each individual factor typically corresponds to a large group of OA constituents with similar chemical composition and temporal behavior that are characteristic of different sources and/or atmospheric processes. The application of this technique in aerosol mass spectrometry has grown rapidly in the last six years. Here we review multivariate factor analysis techniques applied to AMS and other aerosol mass spectrometers, and summarize key findings from field observations. Results that provide valuable information about aerosol sources and, in particular, secondary OA evolution on regional and global scales are highlighted. Advanced methods, for example a-priori constraints on factor mass spectra and the application of factor analysis to combined aerosol and gas phase data are discussed. Integrated analysis of worldwide OA factors is used to present a holistic regional and global description of OA. Finally, different ways in which OA factors can constrain global and regional models are discussed.

Paper # 104: Clinical and Radiological Results After Isolated and Combined Patellofemoral Arthroplasty With the Journey PFJ Trochleashield – A Prospective Study With a Follow Up of 2 Years

Combined patellofemoral arthroplasty with the Journey PFJ Trochleashield for treatment of secondary patellofemoral OA due to patellofemoral instability showed improving good results at two years postoperative follow up. Interestingly isolated procedures for treatment of isolated primary OA showed at two years a slight decline in results after initial good results at the one year follow up.

Hypoalgesic and Motor Effects of Kaltenborn Mobilization on Elderly Patients with Secondary Thumb Carpometacarpal Osteoarthritis: A Randomized Controlled Trial

Objective This study evaluated the effects of Kaltenborn manual therapy on sensory and motor function in elderly patients with secondary carpometacarpal osteoarthritis (CMC OA). Method Twenty-nine female patients with secondary CMC OA (70-90 years old) were randomized into Kaltenborn manual therapy and sham groups. This study was designed as a double-blind, randomized controlled trial (RCT). Therapy consisted of Kaltenborn mobilization of posterior-anterior gliding with distraction in grade 3 of the carpometacarpal (CMC) joint of the dominant hand during 6 sessions over 2 weeks. Pain was measured by algometry, as the pressure pain threshold (PPT) at the CMC joint and tubercle of the scaphoid bone. The tip and tripod pinch strength was also measured. Grip strength was measured by a grip dynamometer. Measurements were taken before treatment and after 1 week (first follow-up [FU]) and 2 weeks (second FU). Results All values in the sham group remained unchanged during the treatment period. In the treated group, the PPT in the CMC joint was 2.98 ± 0.30 kg/cm 2, which increased after treatment to 4.07 ± 0.53, and was maintained at the same level during the first FU (3.46 ± 0.31) and second FU (3.84 ± 0.36). Similarly, the PPT in the scaphoid bone was 3.61 ± 0.29 kg/cm 2, which increased after treatment to 4.87 ± 0.37, and was maintained at the same level during the first FU (4.44 ± 0.43) and second FU (4.22 ± 0.32). In contrast, we found no differences in the tip, tripod pinch, and grip strength measurements between the treatment and sham groups. Conclusions This study showed that Kaltenborn manual therapy decreased pain in the CMC joint and scaphoid bone areas of elderly female patients; however, it did not confer an increase in motor function in patients with CMC OA.

Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behavior

Abstract. Vacuum Ultraviolet (VUV) photoionization mass spectrometry has been used to measure the evolution of chemical composition for two distinct organic aerosol types as they are passed through a thermodenuder at different temperatures. The two organic aerosol types considered are primary lubricating oil (LO) aerosol and secondary aerosol from the α-pinene + O3 reaction (αP). The evolution of the VUV mass spectra for the two aerosol types with temperature are observed to differ dramatically. For LO particles, the spectra exhibit distinct changes with temperature in which the lower m/z peaks, corresponding to compounds with higher vapor pressures, disappear more rapidly than the high m/z peaks. In contrast, the αP aerosol spectrum is essentially unchanged by temperature even though the particles experience significant mass loss due to evaporation. The variations in the LO spectra are found to be quantitatively in agreement with expectations from absorptive partitioning theory whereas the αP spectra suggest that the evaporation of αP derived aerosol appears to not be governed by partitioning theory. We postulate that this difference arises from diffusivity within the αP particles being sufficiently slow that they do not exhibit the expected liquid-like behavior and perhaps exist in a glassy state. To reconcile these observations with decades of aerosol growth measurements, which indicate that OA formation is described by equilibrium partitioning, we present a conceptual model wherein the secondary OA is formed and then rapidly converted from an absorbing form to a non-absorbing form. The results suggest that, although OA growth may be describable by equilibrium partitioning theory, the properties of organic aerosol once formed may differ significantly from the properties determined in the equilibrium framework.

Efficacy of leech therapy in the management of osteoarthritis (Sandhivata)

Osteoarthritis (degenerative joint disease) is the most common joint disorder. It mostly affects cartilage. The top layer of cartilage breaks down and wears away. Osteoarthritis is of two types, primary (idiopathic) and secondary. In idiopathic osteoarthritis, the most common form of the disease, no predisposing factor is apparent. Secondary OA is pathologically indistinguishable from idiopathic OA but is attributable to an underlying cause. In Ayurveda the disease Sandhivata resembles with osteoarthritis which is described under Vatavyadhi. The NSAIDs are the main drugs of choice in modern medicine which have lots of side effects and therefore are not safe for long-term therapy. Raktamokshan, i.e., blood letting is one of the ancient and important parasurgical procedures described in Ayurveda for treatment of various diseases. Of them, Jalaukavacharana or leech therapy has gained greater attention globally, because of its medicinal values. The saliva of leech contains numerous biologically active substances, which have antiinflammatory as well as anesthetic properties. Keeping this view in mind we have started leech therapy in the patients of osteoarthritis and found encouraging results.

Modeling organic aerosols during MILAGRO: importance of biogenic secondary organic aerosols

Abstract. The meso-scale chemistry-transport model CHIMERE is used to assess our understanding of major sources and formation processes leading to a fairly large amount of organic aerosols – OA, including primary OA (POA) and secondary OA (SOA) – observed in Mexico City during the MILAGRO field project (March 2006). Chemical analyses of submicron aerosols from aerosol mass spectrometers (AMS) indicate that organic particles found in the Mexico City basin contain a large fraction of oxygenated organic species (OOA) which have strong correspondence with SOA, and that their production actively continues downwind of the city. The SOA formation is modeled here by the one-step oxidation of anthropogenic (i.e. aromatics, alkanes), biogenic (i.e. monoterpenes and isoprene), and biomass-burning SOA precursors and their partitioning into both organic and aqueous phases. Conservative assumptions are made for uncertain parameters to maximize the amount of SOA produced by the model. The near-surface model evaluation shows that predicted OA correlates reasonably well with measurements during the campaign, however it remains a factor of 2 lower than the measured total OA. Fairly good agreement is found between predicted and observed POA within the city suggesting that anthropogenic and biomass burning emissions are reasonably captured. Consistent with previous studies in Mexico City, large discrepancies are encountered for SOA, with a factor of 2–10 model underestimate. When only anthropogenic SOA precursors were considered, the model was able to reproduce within a factor of two the sharp increase in OOA concentrations during the late morning at both urban and near-urban locations but the discrepancy increases rapidly later in the day, consistent with previous results, and is especially obvious when the column-integrated SOA mass is considered instead of the surface concentration. The increase in the missing SOA mass in the afternoon coincides with the sharp drop in POA suggesting a tendency of the model to excessively evaporate the freshly formed SOA. Predicted SOA concentrations in our base case were extremely low when photochemistry was not active, especially overnight, as the SOA formed in the previous day was mostly quickly advected away from the basin. These nighttime discrepancies were not significantly reduced when greatly enhanced partitioning to the aerosol phase was assumed. Model sensitivity results suggest that observed nighttime OOA concentrations are strongly influenced by a regional background SOA (~1.5 μg/m3) of biogenic origin which is transported from the coastal mountain ranges into the Mexico City basin. The presence of biogenic SOA in Mexico City was confirmed by SOA tracer-derived estimates that have reported 1.14 (±0.22) μg/m3 of biogenic SOA at T0, and 1.35 (±0.24) μg/m3 at T1, which are of the same order as the model. Consistent with other recent studies, we find that biogenic SOA does not appear to be underestimated significantly by traditional models, in strong contrast to what is observed for anthropogenic pollution. The relative contribution of biogenic SOA to predicted monthly mean SOA levels (traditional approach) is estimated to be more than 30% within the city and up to 65% at the regional scale which may help explain the significant amount of modern carbon in the aerosols inside the city during low biomass burning periods. The anthropogenic emissions of isoprene and its nighttime oxidation by NO3 were also found to enhance the SOA mean concentrations within the city by an additional 15%. Our results confirm the large underestimation of the SOA production by traditional models in polluted regions (estimated as 10–20 tons within the Mexico City metropolitan area during the daily peak), and emphasize for the first time the role of biogenic precursors in this region, indicating that they cannot be neglected in urban modeling studies.