bluuebunny/crossref_metadata_2025 huggingface dataset:
Immune-Mediated Mechanisms of Parasite Tissue Sequestration during Experimental Cerebral Malaria
Authors: Amante Fiona H. , Haque Ashraful , Stanley Amanda C. , Rivera Fabian de Labastida , Randall Louise M. , Wilson Yana A. , Yeo Gladys , Pieper Christian , Crabb Brendan S. , de Koning-Ward Tania F. , Lundie Rachel J. , Good Michael F. , Pinzon-Charry Alberto , Pearson Mark S. , Duke Mary G. , McManus Donald P. , Loukas Alex , Hill Geoff R. , Engwerda Christian R.
Published: August 2010

Cerebral malaria is a severe complication of malaria. Sequestration of parasitized RBCs in brain microvasculature is associated with disease pathogenesis, but our understanding of this process is incomplete. In this study, we examined parasite tissue sequestration in an experimental model of cerebral malaria (ECM). We show that a rapid increase in parasite biomass is strongly associated with the induction of ECM, mediated by IFN-γ and lymphotoxin α, whereas TNF and IL-10 limit this process. Crucially, we discovered that host CD4+ and CD8+ T cells promote parasite accumulation in vital organs, including the brain. Modulation of CD4+ T cell responses by helminth coinfection amplified CD4+ T cell-mediated parasite sequestration, whereas vaccination could generate CD4+ T cells that reduced parasite biomass and prevented ECM. These findings provide novel insights into immune-mediated mechanisms of ECM pathogenesis and highlight the potential of T cells to both prevent and promote infectious diseases.
CCR6 Marks Regulatory T Cells as a Colon-Tropic, IL-10–Producing Phenotype
Authors: Kitamura Kazuya , Farber Joshua M. , Kelsall Brian L.
Published: August 2010

Expression of CCR6 and its ligand, CCL20, are increased in the colon of humans with inflammatory bowel diseases and mice with experimental colitis; however, their role in disease pathogenesis remains obscure. In this study, we demonstrate a role for CCR6 on regulatory T (Treg) cells in the T cell-transfer model of colitis. Rag2−/− mice given Ccr6−/−CD4+CD45RBhigh T cells had more severe colitis with increased IFN-γ–producing T cells, compared with the mice given wild-type cells. Although an equivalent frequency of induced/acquired Treg (iTreg) cells was observed in mesenteric lymph nodes and colon from both groups, the suppressive capacity of Ccr6−/− iTreg cells was impaired. Cotransfer studies of wild-type or Ccr6−/− Treg cells with CD4+CD45RBhigh T cells also showed a defect in suppression by Ccr6−/− Treg cells. CCR6+ Treg cells were characterized as Ag-activated and IL-10–producing in the steady-state and preferentially migrated to the colon during inflammation. Thus, we conclude that CCR6 expression on Treg cells was required for the full function of Treg cell-mediated suppression in the T cell-transfer model of colitis. CCR6 may contribute to the regulation of colitis by directing its function in Ag-specific, IL-10–producing iTreg cells to the inflamed colon.
Prolonged Antigen Storage Endows Merocytic Dendritic Cells with Enhanced Capacity To Prime Anti-Tumor Responses in Tumor-Bearing Mice
Authors: Reboulet Rachel A. , Hennies Cassandra M. , Garcia Zacarias , Nierkens Stefan , Janssen Edith M.
Published: August 2010

Tumor cell vaccination with irradiated autologous tumor cells is a promising approach to activate tumor-specific T cell responses without the need for tumor Ag identification. However, uptake of dying cells by dendritic cells (DCs) is generally a noninflammatory or tolerizing event to prevent the development of autoreactive immune responses. In this study, we describe the mechanisms that confer the potent T cell priming capacity of a recently identified a population of DCs (merocytic DCs [mcDCs]) that potently primes both CD8+ and CD4+ T cells to cell-associated Ags upon uptake of apoptotic cells. mcDCs acquired cell-associated materials through a process of merocytosis that is defined by the uptake of small particles that are stored in nonacidic compartments for prolonged periods, sustained Ag presentation, and the induction of type I IFN. T cells primed by mcDCs to cell-associated Ags exhibit increased primary expansion, enhanced effector function, and increased memory formation. By using transgenic T cell transfer models and endogenous models, we show that treatment of tumor-bearing mice with mcDCs that have been exposed to dying tumor cells results in tumor suppression and increased host survival through the activation of naive tumor-specific CD8+ T cells as well as the reinvigoration of tumor-specific T cells that had been rendered nonresponsive by the tumor in vivo. The potent capacity of mcDCs to prime both CD4+ and CD8+ T cells to cell-associated Ags under immunosuppressive conditions makes this DC subset an attractive target for tumor therapies as well as interventional strategies for autoimmunity and transplantation.
Nonmalignant Clonal Expansions of Memory CD8+ T Cells That Arise with Age Vary in Their Capacity To Mount Recall Responses to Infection
Authors: Kohlmeier Jacob E. , Connor Lisa M. , Roberts Alan D. , Cookenham Tres , Martin Kyle , Woodland David L.
Published: August 2010

Immune responsiveness declines with age in part due to the development of CD8+ T cell clonal expansions (TCEs) that can dominate the peripheral T cell pool. Although some TCEs arise due to persistent Ag stimulation from chronic infections, others arise in the apparent absence of chronic infection. We have recently shown that this latter class of TCEs can arise over time from the memory CD8+ T cell pool established by an acute viral infection. Unlike TCEs driven by chronic infections, these age-related TCEs do not display the phenotypic and in vitro functional characteristics of exhausted cells. However, the rate at which these age-related TCEs develop from the memory CD8+ T cell pool, as well as their ability to mount a recall response to secondary pathogen challenge in vivo, is not known. In this study, we analyzed large cohorts of mice over time for the development of TCE following Sendai virus infection and found a progressive increase in the appearance of TCEs, such that most mice showed evidence of TCE within the memory T cell pool by 2 y postinfection. Using a dual adoptive transfer approach to address the recall potential of virus-specific TCEs, we also demonstrate that most TCEs examined are poorly responsive to a secondary infection. Therefore, we provide evidence that the development of TCE is a common occurrence due to the progressive dysregulation of the virus-specific memory T cell pool with age, but many TCEs are profoundly defective in their ability to mediate recall responses.
ParkinExon Rearrangements and Sequence Variants inLRRK2Mutations Carriers: Analysis on a Possible Modifier Effect onLRRK2Penetrance
Authors: Solla Paolo , Cannas Antonino , Floris Gianluca , Murru Maria Rita , Corongiu Daniela , Tranquilli Stefania , Cuccu Stefania , Rolesu Marcella , Marrosu Francesco , Marrosu Maria Giovanna
Published: August 2010

Mutations inLRRK2represent the most common causes of Parkinson's disease (PD) identified to date, but their penetrance is incomplete and probably due to the presence of other genetic or environmental factors required for development of the disease. We analyzed the presence ofparkinsequence variants (mutations or polymorphisms) and exon rearrangements inLRRK2mutations carriers (both PD patients and unaffected relatives) in order to detect a possible modifier effect on penetrance. Eight families with nine PD patients with heterozygousLRRK2mutations (identified within 380 Sardinian PD patients screened for the presence of the five most commonLRRK2mutations) and sixteen additional relatives were genetically investigated for the presence ofLRRK2andparkinmutations. No evidence was found for the presence of pathologicalparkinmutations or exon rearrangements in patients or not affected family members. Three single-nucleotide polymorphisms (SNPs) were identified both in patients and unaffected relatives but did not significantly differ between the two groups. These data provide no support to the hypothesis whereby suchparkingene mutations may be commonly implicated in possible effect on penetrance inLRRK2mutation carriers.
Global analysis of cloud field coverage and radiative properties, using morphological methods and MODIS observations
Authors: Bar-Or R. Z. , Altaratz O. , Koren I.
Published: August 2010

Abstract. The recently recognized continuous transition zone between detectable clouds and cloud-free atmosphere ("the twilight zone") is affected by undetectable clouds and humidified aerosol. In this study, we suggest to distinguish cloud fields (including the detectable clouds and the surrounding twilight zone) from cloud-free areas, which are not affected by clouds. For this classification, a robust and simple-to-implement cloud field masking algorithm which uses only the spatial distribution of clouds, is presented in detail. A global analysis, estimating Earth's cloud field coverage (50° S–50° N) for 28 July 2008, using the Moderate Resolution Imaging Spectroradiometer (MODIS) data, finds that while the declared cloud fraction is 51%, the global cloud field coverage reaches 88%. The results reveal the low likelihood for finding a cloud free pixel and suggest that this likelihood may decrease as the pixel size becomes larger. A global latitudinal analysis of cloud fields finds that unlike oceans, which are more uniformly covered by cloud fields, land areas located under the subsidence zones of the Hadley cell (the desert belts), contain proper areas for investigating cloud free atmosphere as there is 40–80% probability to detect clear sky over them. Usually these golden-pixels, with higher likelihood to be free of clouds, are over deserts. Independent global statistical analysis, using MODIS aerosol and cloud products, reveals a sharp exponential decay of the global mean aerosol optical depth (AOD) as a function of the distance from the nearest detectable cloud, both above ocean and land. Similar statistical analysis finds an exponential growth of mean aerosol fine-mode fraction (FMF) over Oceans when the distance from the nearest cloud increases. A 30 km scale break clearly appears in several analyses here, suggesting this is a typical natural scale of cloud fields. This work shows different microphysical and optical properties of cloud fields, urging to separately investigate cloud fields and cloud-free atmosphere in future climate research.
An automatic contrail tracking algorithm
Authors: Vazquez-Navarro M. , Mannstein H. , Mayer B.
Published: August 2010

Abstract. A method designed to track the life cycle of contrail-cirrus using satellite data with high temporal and spatial resolution, from its formation to the final dissolution of the aviation-induced cirrus cloud is presented. The method follows the evolution of contrails from their linear stage until they are undistinguishable from natural cirrus clouds. Therefore, the study of the effect of aircraft-induced clouds in the atmosphere is no longer restricted to linear contrails and can include contrail-cirrus. The method takes advantage of the high spatial resolution of polar orbiting satellites and the high temporal resolution of geostationary satellites to identify the pixels that belong to an aviation induced cloud. The high spatial resolution data of the MODIS sensor is used for contrail detection, and the high temporal resolution of the SEVIRI sensor in the Rapid Scan mode is used for contrail tracking. An example is included in which the method is applied to the study of a long lived contrail over the bay of Biscay.
Synergetic cloud fraction determination for SCIAMACHY using MERIS
Authors: Schlundt C. , Kokhanovsky A. A. , von Hoyningen-Huene W. , Dinter T. , Istomina L. , Burrows J. P.
Published: August 2010

Abstract. Since clouds play an essential role in the Earth's climate system, it is important to understand the cloud characteristics as well as their distribution on a global scale using satellite observations. The main scientific objective of SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) onboard the ENVISAT satellite is the retrieval of vertical columns of trace gases. On the one hand, SCIAMACHY has to be sensitive to low variations in trace gas concentrations which means the ground pixel size has to be large enough. On the other hand, such a large pixel size leads to the problem that SCIAMACHY spectra are often contaminated by clouds. SCIAMACHY spectral measurements are not well suitable to derive a reliable sub-pixel cloud fraction that can be used as input parameter for subsequent retrievals of cloud properties or vertical trace gas columns. Therefore, we use MERIS/ENVISAT spectral measurements with its high spatial resolution as sub-pixel information for the determination of MerIs Cloud fRation fOr Sciamachy (MICROS). Since MERIS covers an even broader swath width than SCIAMACHY, no problems in spatial and temporal collocation of measurements occur. This enables the derivation of a SCIAMACHY cloud fraction with an accuracy much higher as compared with other current cloud fractions that are based on SCIAMACHY's PMD (Polarization Measurement Device) data. We present our new developed MICROS algorithm, based on the threshold approach, as well as a qualitative validation of our results with MERIS satellite images for different locations, especially with respect to bright surfaces such as snow/ice and sands. In addition, the SCIAMACHY cloud fractions derived from MICROS are intercompared with other current SCIAMACHY cloud fractions based on different approaches demonstrating a considerable improvement regarding geometric cloud fraction determination using the MICROS algorithm.
Adaptive method of lines for multi-component aerosol condensational growth and cloud droplet activation
Authors: Arabas S. , Pawlowska H.
Published: August 2010

Abstract. The process of formation of cloud droplets on an ensemble of aerosol particles is modelled by numerous investigators using the method of lines (MOL). The method involves discretization of the aerosol size spectrum into bins whose position and width evolve with time. One of the drawbacks of the method is its poor representation of the aerosol spectrum shape in the region between the unactivated aerosol mode and the activated cloud-droplet mode. An adaptive spectrum refinement procedure that improves the performance of the method is introduced and tested. A model of drop formation on multi-component aerosol is formulated for the purpose of the study. Model formulation includes explicit treatment of the drop temperature evolution. Several examples of the model set-up are used to demonstrate model capabilities. Model results are compared to those without adaptivity, and are compared to the Twomey's formul\\ae. A C++ implementation of the model is available as an electronic supplement of the paper.
Soil moisture and evapotranspiration of wetlands vegetation habitats retrieved from satellite images
Authors: Dabrowska-Zielinska K. , Budzynska M. , Kowalik W. , Turlej K.
Published: August 2010

Abstract. The research has been carried out in Biebrza Ramsar Convention test site situated in the N-E part of Poland. Data from optical and microwave satellite images have been analysed and compared to the detailed soil-vegetation ground truth measurements conducted during the satellite overpasses. Satellite data applied for the study include: ENVISAT.ASAR, ENVISAT.MERIS, ALOS.PALSAR, ALOS.AVNIR-2, ALOS.PRISM, TERRA.ASTER, and NOAA.AVHRR. Optical images have been used for classification of wetlands vegetation habitats and vegetation surface roughness expressed by LAI. Also, heat fluxes have been calculated using NOAA.AVHRR data and meteorological data. Microwave images have been used for the assessment of soil moisture. For each of the classified wetlands vegetation habitats the relationship between soil moisture and backscattering coefficient has been examined, and the best combination of microwave variables (wave length, incidence angle, polarization) has been used for mapping and monitoring of soil moisture. The results of this study give possibility to improve models of water cycle over wetlands ecosystems by adding information about soil moisture and surface heat fluxes derived from satellite images. Such information is very essential for better protection of the European sensitive wetland ecosystems. ENVISAT and ALOS images have been obtained from ESA for AO ID 122 and AOALO.3742 projects.
Climate change and its effect on agriculture, water resources and human health sectors in Poland
Authors: Szwed M. , Karg G. , Pińskwar I. , Radziejewski M. , Graczyk D. , Kędziora A. , Kundzewicz Z. W.
Published: August 2010

Abstract. Multi-model ensemble climate projections in the ENSEMBLES Project of the EU allowed the authors to quantify selected extreme-weather indices for Poland, of importance to climate impacts on systems and sectors. Among indices were: number of days in a year with high value of the heat index; with high maximum and minimum temperatures; length of vegetation period; and number of consecutive dry days. Agricultural, hydrological, and human health indices were applied to evaluate the changing risk of weather extremes in Poland in three sectors. To achieve this, model-based simulations were compared for two time horizons, a century apart, i.e., 1961–1990 and 2061–2090. Climate changes, and in particular increases in temperature and changes in rainfall, have strong impacts on agriculture via weather extremes – droughts and heat waves. The crop yield depends particularly on water availability in the plant development phase. To estimate the changes in present and future yield of two crops important for Polish agriculture i.e., potatoes and wheat, some simple empirical models were used. For these crops, decrease of yield is projected for most of the country, with national means of yield change being: –2.175 t/ha for potatoes and –0.539 t/ha for wheat. Already now, in most of Poland, evapotranspiration exceeds precipitation during summer, hence the water storage (in surface water bodies, soil and ground) decreases. Summer precipitation deficit is projected to increase considerably in the future. The additional water supplies (above precipitation) needed to use the agro-potential of the environment would increase by half. Analysis of water balance components (now and in the projected future) can corroborate such conclusions. As regards climate and health, a composite index, proposed in this paper, is a product of the number of senior discomfort days and the number of seniors (aged 65+). The value of this index is projected to increase over 8-fold during 100 years. This is an effect of both increase in the number of seniors (over twofold) and the number of senior-discomfort days (nearly fourfold).
Assessment of the natural history of forefoot bursae using ultrasonography in patients with rheumatoid arthritis: A twelve‐month investigation
Authors: Bowen Catherine J. , Hooper Lindsey , Culliford David , Dewbury Keith , Sampson Madeleine , Burridge Jane , Edwards Christopher J. , Arden Nigel K.
Published: August 2010

Objective

To determine the natural history and clinical significance of forefoot bursae over a 12‐month period in patients with rheumatoid arthritis (RA).

Methods

Patients with RA (n = 149) attending rheumatology outpatient clinics were assessed at baseline. A total of 120 participants, mean ± SD age 60.7 ± 12.1 years and mean ± SD disease duration 12.99 ± 10.4 years, completed the 12‐month followup (98 women, 22 men, 93 rheumatoid factor positive, 24 rheumatoid factor negative, and 3 unknown). Musculoskeletal ultrasound (US) was used to identify forefoot bursae in all of the participants. Clinical markers of disease activity (well‐being visual analog scale [VAS], erythrocyte sedimentation rate [ESR], C‐reactive protein [CRP] level, and Disease Activity Score in 28 joints [DAS28]) and foot symptoms on the Leeds Foot Impact Scale (LFIS) Questionnaire were recorded on both occasions.

Results

Presence of US‐detectable forefoot bursae was identified in 93.3% of returnee (n = 120) participants (individual mean 3.7, range 0–11) at baseline. Significant associations were identified between bursae presence and patient‐reported foot impact for impairment/footwear (LFISIF; baseline: r = 0.226, P = 0.013 and 12 months: r = 0.236, P = 0.009) and activity limitation/participation restriction (LFISAP; baseline: r = 0.254, P = 0.005 and 12 months: r = 0.235, P = 0.010). After 12 months, 42.5% of participants had an increase in the number of US‐detectable forefoot bursae and 45% of participants had a decrease. Changes in bursae number significantly correlated with changes in LFISIF (r = 0.216, P = 0.018) and LFISAP (r = 0.193, P = 0.036). No significant associations were identified between changes in bursae and changes in global well‐being VAS, ESR, CRP level, or DAS28.

Conclusion

The findings of this study suggest that forefoot bursae may regress or hypertrophy over time in patients with RA, and that these changes may be associated with self‐reported foot impairment and activity restriction.
Emotional, physical, and sexual abuse in fibromyalgia syndrome: A systematic review with meta‐analysis
Authors: Häuser Winfried , Kosseva Maria , Üceyler Nurcan , Klose Petra , Sommer Claudia
Published: August 2010

Objective

To systematically assess the potential association of fibromyalgia syndrome (FMS) with emotional, physical, and sexual abuse.

Methods

The databases EMBase, Google Scholar, Medline, and PsycINFO (through April 2010) and the reference sections of original studies were searched for eligible studies. Eligible studies were cohort or case–control studies that assessed at least one type of emotional, physical, or sexual abuse in childhood or adulthood in patients with FMS and in controls. Two authors independently extracted descriptive, quality, and outcome data from included studies. Methodologic quality was assessed by the Newcastle‐Ottawa Quality Assessment Scale. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were pooled across studies by using the random‐effects model. Heterogeneity was assessed by I2 statistics.

Results

The search identified 18 eligible case–control studies with 13,095 subjects. There were significant associations between FMS and self‐reported physical abuse in childhood (OR 2.49 [95% CI 1.81–3.42], I2 = 0%; 9 studies) and adulthood (OR 3.07 [95% CI 1.01–9.39], I2 = 79%; 3 studies), and sexual abuse in childhood (OR 1.94 [95% CI 1.36–2.75], I2 = 20%; 10 studies) and adulthood (OR 2.24 [95% CI 1.07–4.70], I2 = 64%; 4 studies). Study quality was mostly poor. Low study quality was associated with higher effect sizes for sexual abuse in childhood, but not with other effect sizes.

Conclusion

The association of FMS with physical and sexual abuse could be confirmed, but is confounded by study quality.
Do spouses know how much fatigue, pain, and physical limitation their partners with rheumatoid arthritis experience? Implications for social support
Authors: Lehman Allen J. , Pratt Daniel D. , DeLongis Anita , Collins John B. , Shojania Kam , Koehler Barry , Offer Robert , Esdaile John M.
Published: August 2010

Objective

To determine whether perceptions of clinical manifestations (fatigue, pain, and physical limitation) of rheumatoid arthritis (RA) differ between spouses and their partners with RA, and to determine whether the differences are associated with the perception of beneficial and problematic spousal social support.

Methods

English‐speaking adults with RA of ≥6 months' duration and their spouses (n = 222 couples) completed standardized questionnaires for fatigue, pain, physical limitation, beneficial spousal support, and problematic spousal support. Spouses completed questionnaires based on their perception of their partner with RA. Agreement scores for fatigue, pain, and physical limitation were calculated by subtracting spouse scores from the scores of the partner with RA. Agreement levels were defined a priori: agreement (within ± one‐half of a minimum clinically important difference [MCID] unit), overestimator (< one‐half an MCID), and underestimator (> one‐half an MCID). Separate hierarchical linear regression models were used to measure the association between beneficial support and problematic support after adjusting for RA duration, physical health, sex, educational level, relationship duration, and satisfaction.

Results

Response rate for couples was 82%. Relative to participants with RA, spouses overestimated fatigue (26%), pain (29%), and physical limitation (39%), and underestimated fatigue (11%), pain (17%), and physical limitation (34%). After statistically controlling for demographic, disease, and psychosocial variables, participants with RA whose spouses underestimated fatigue received more problematic support (R2 = 3.7%, P = 0.002), as did those whose spouses underestimated or overestimated physical limitation (R2 = 3.4%, P = 0.017).

Conclusion

Persons with RA perceived more problematic spousal support when their spouse underestimated fatigue, or underestimated or overestimated physical limitation levels.
Prophylactic antibiotics for the prevention of neutropenic fever in patients undergoing autologous stem‐cell transplantation: Results of a single institution, randomized phase 2 trial
Authors: Eleutherakis‐Papaiakovou Evangelos , Kostis Evangelos , Migkou Magda , Christoulas Dimitrios , Terpos Evangelos , Gavriatopoulou Maria , Roussou Maria , Bournakis Evangelos , Kastritis Efstathios , Efstathiou Eleni , Dimopoulos Meletios A. , Papadimitriou Christos A.
Published: August 2010

One hundred and fifty‐seven patients undergoing high‐dose chemotherapy (HDT) and autologous stem‐cell transplantation (ASCT) for hematopoietic malignancies and solid tumors were randomly assigned to receive (Group A) or not (Group B) prophylaxis with ciprofloxacin, orally, and vancomycin, intravenously. Prophylactic antibiotics were given from day 0 until resolution of neutropenia or the appearance of a febrile event. Furthermore, patients in both groups received once a day fluconazole, orally. The primary end‐point of our study was the incidence of neutropenic febrile episodes attributed to infection. One hundred and twelve (71.3%) patients developed neutropenic fever, 50 (56.2%) in Group A and 62 (91.2%) in Group B (P < 0.001) with the majority (82%) of patients developing fever of unknown origin. Patients on prophylactic antibiotics had a significantly lower rate of bacteremias (5.6%) than did those randomized to no prophylaxis (29.4%) (P = 0.005) and, when developing neutropenic fever, they had a lower probability of response to first‐line empirical antibiotics (P = 0.025). Prophylactic administration of ciprofloxacin and vancomycin reduced the incidence of neutropenic fever in patients receiving HDT with ASCT, however, without affecting the total interval of hospitalization, time to engraftment, or all‐cause mortality. Therefore, our results do not support the use of antibiotic prophylaxis for patients undergoing HDT and ASCT. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.
A case of occupational peritoneal mesothelioma from exposure to tremolite‐free chrysotile in Quebec, Canada: A black swan case
Authors: Egilman David , Menéndez Lelia M.
Published: August 2010

Background

Tremolite contamination has been proposed as the cause of mesothelioma in workers exposed to commercial chrysotile. The asbestos industry and scientists it has sponsored, for example, have argued that commercial chrysotile does not cause peritoneal mesothelioma.

Method

Case report of peritoneal mesothelioma in a mill worker from a tremolite free Canadian mine.

Results

Reports from pathology and occupational health and safety panels conclude that this mill worker developed work‐related peritoneal mesothelioma.

Conclusion

Chrysotile without tremolite can cause peritoneal mesothelioma. Am. J. Ind. Med. 54:153–156, 2011. © 2010 Wiley‐Liss, Inc.
The estimated national burden of physical ergonomic hazards among US workers
Authors: Tak SangWoo , Calvert Geoffrey M.
Published: August 2010

Purpose

To estimate the national burden of physical ergonomic hazards among working adults in the US.

Methods

We estimated the population prevalence of and the total number of workers who are exposed to physical ergonomic hazards, such as vibration, working in cramped space, kneeling, body bending or twisting, climbing, and repetitive motions using Occupational Information Network (O*NET) data and the Occupational Employment Statistics (OES) from the U.S. Bureau of Labor Statistics (BLS) stratified by occupation title.

Results

Repetitive motion was the most prevalent of all ergonomic hazards (27% of US workers are estimated to be exposed continually). Bending or twisting of the body more than half their time at work was also common, involving over 32 million US workers (25% of US workforce). Kneeling, crouching, stooping, or crawling was another ergonomic hazard that 14 million US workers perform more than half their time at work. Almost 4 million workers climb ladders, scaffolds, poles, etc. for more than half their time at work. We estimate that over 13 million workers (10% of US workforce) were exposed to cramped workspace that requires getting into awkward positions every day. Finally, about 3.5 million workers (2.7% of US workforce) were estimated to be exposed to whole body vibration every day.

Conclusion

A large portion of the US work force is exposed to ergonomic hazards known to be associated with musculoskeletal disorders (MSDs). The occupations with the highest prevalence of each ergonomic hazard may be deserving of prompt efforts toward prevention of MSDs. Am. J. Ind. Med. 54:395–404, 2011. © 2010 Wiley‐Liss, Inc.
Work‐relatedness of selected chronic medical conditions and workers' compensation utilization: National health interview survey occupational health supplement data
Authors: Luckhaupt Sara E. , Calvert Geoffrey M.
Published: August 2010

Background

An occupational health supplement (OHS) to the 1988 National Health Interview Survey (NHIS) bypassed many limitations of traditional occupational health surveillance systems, but the data collected about chronic work‐related conditions have not yet been reported.

Methods

We calculated the prevalence and proportion of cases related to work for the aggregation of 13 chronic conditions included in the NHIS‐OHS, and for 11 conditions individually. For each of nine conditions, and for the aggregation of all conditions, we also calculated the prevalence of workers' compensation claims filed.

Results

The overall prevalence of work‐related chronic conditions was 7.5% (SE = 0.16). The work‐related conditions with the highest prevalence were repeated trouble with the back/neck/spine (4.91%; SE = 0.13) and trouble hearing (1.14%; SE = 0.06). Overall, workers' compensation claims were filed for 39.0% (SE = 1.00) of work‐related cases.

Conclusions

The burden of work‐related illnesses in the US is substantial, and the workers' compensation system is underutilized. Am. J. Ind. Med. 53:1252–1263, 2010. © 2010 Wiley‐Liss, Inc.
Diverse morphologies of PVDF hollow fiber membranes and their performance analysis as gas/liquid contactors
Authors: Feng Chunsheng , Wang Rong , Zhang Hongyan , Shi Lei
Published: August 2010

A systematic investigation on the morphology development of polyvinylidene fluoride hollow fiber membrane made using various N‐methyl‐2‐pyrrolidone (NMP) aqueous solutions as an inner coagulant was carried out. The cross‐sectional and inner surface morphology were analyzed with scanning electronic microscopy (SEM). It is found that with increase on NMP concentration, the morphology of the resultant membranes gradually shifted from a double‐skin to a single‐skin structure. When 40.0 ∼ 55.0 wt.% NMP solution was used, some unexpected macrovoids near the inner region were observed. This special morphology feature was attributed to the reduced solidification rate of the inner surface as a result of increase on NMP concentration, which sharply weakened the inner skin strength. While the existence of centralized stress formed in the phase inversion process, such as shrinkage stress from syneresis, resulted in fractured points in the nascent skin surface that finally made it difficult to maintain a uniform structure. Investigations on effects of the dope flow rate and the bore fluid velocity on the morphology of PVDF fiber membranes experimentally confirmed the suggestion. Three model membranes with double skins, single skin and single skin with macrovoids structures, respectively, were used to test their permeation performance in a CO2 membrane contactor system. The experimental results show the membranes without an inner skin present higher permeability and lower mass transfer resistance than the membrane with a double skin structure. © 2010 Wiley Periodicals, Inc. Journal of Applied Polymer Science, 2010
Crystallization behavior and foaming properties of polypropylene containing ultra‐high molecular weight polyethylene under supercritical carbondioxide
Authors: Xin Chunling , He Yadong , Li Qingchun , Huang Yingzhu , Yan Baorui , Wang Xiaodong
Published: August 2010

In this study, a systematic investigation on the nonisothermal crystallization kinetics of conversional polypropylene (PP) containing various amounts of ultra‐high molecular weight polyethylene (UHMWPE) was reported, and the effects of UHMWPE on crystallization behavior of these PP materials and their foaming properties were also presented. The kinetic studies revealed that the incorporation of UHMWPE into PP led to an increase in the crystallization temperature and temperature range during the crystallization process as well as the relative crystallinity. This behavior was attributed to a comprehensive effect of the nucleation and entanglement of the UHMWPE chains. The kinetic models based on Ozawa's and Mo's methods were used to analyze the nonisothermal crystallization behaviors. It was found that the latter succeeded in describing the nonisothermal crystallization behavior of the PP containing UHMWPE, while the former was not appropriate. The activation energy for the nonisothermal crystallization determined by Kissinger's method also indicated that the crystallization ability of PP was improved with the addition of UHMWPE. Owing to the modification of the crystallization kinetics of the PP materials by introduction of UHMWPE, the foaming properties (i.e., cell uniformity and expandability etc.) were improved significantly. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Formulation and in vitro evaluation of transdermal delivery of zidovudine—An anti‐HIV drug
Authors: Mundargi Raghavendra C. , Babu V. Ramesh , Rangaswamy Vidhya , Aminabhavi Tejraj M.
Published: August 2010

This study was designed to develop matrix type of transdermal‐controlled delivery system for zidovudine using Eudragit L100 by varying the amounts of drug in addition to polyethylene glycol as a plasticizer and Tween 80® as a penetration enhancer. Transparent smooth and flexible films were characterized for weight, thickness uniformity, and drug content. Drug interactions with the polymer films were studied by differential scanning calorimetry, whereas X‐ray diffraction was used to understand the drug polymorphism in the films. The in vitro drug release experiments were performed in phosphate buffer using the Keshary‐Chien diffusion cell. Variations of drug release profiles were analyzed using the Ritger and Peppas empirical equation to describe the type of release mechanism. The exponent n values of the equation varied over the wide range of 0.75–2.23, suggesting non‐Fickian to super Case‐II type of diffusion transport. Statistical analyses of release data performed by the analysis of variance (ANOVA) method indicated significant differences within experimental measurements. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Montmorillonite‐filled nanocomposites of tung oil/styrene/divinylbenzene polymers prepared by thermal polymerization
Authors: Kundu P. P. , Larock R. C.
Published: August 2010

Montmorillonite‐filled nanocomposites were prepared by the thermal copolymerization of tung oil (TUNG), styrene (ST), and divinylbenzene (DVB). These nanocomposites were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), and their mechanical properties. The XRD of the modified montmorillonite exhibited a peak that vanished completely in the nanocomposites. Thus, the XRD results apparently indicate a distortion of the platy layers of the nanofiller in the TUNG–ST–DVB polymers. A platy nanolayered structure of the modified montmorillonite in the TUNG–ST–DVB polymers was observed by TEM. The extent of separation of the platy layers as observed by the TEM reached a maximum for the 5% modified nanofiller (at a fixed polymer composition), 50%‐oil‐containing polymer (at a fixed nanofiller concentration of 5%), and TUNG intragallery nanocomposites (at both fixed polymer and nanofiller concentrations). The DMA results show a broadened glass‐transition temperature along with a hump for these nanofilled polymers, indicating the presence as a majority constituent of a copolymer consisting of TUNG and aromatics, along with a grafted TUNG polymer, respectively. The improvements in the Young's modulus and compressive strength upon incorporation of the nanofiller indicated the presence of a partially intercalated and distorted platy‐layered structure of the nanofiller. However, from the results of all of these studies, it was tough to estimate the exact level of delamination/exfoliation in these TUNG nanocomoposites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis, characterization, and preliminary antimicrobial evaluation of bisphenol‐A formaldehyde resin coordinated with transition metal complexes of ethylenediamine
Authors: Nishat Nahid , Asma  , Manisha
Published: August 2010

Coordination polymers containing bisphenol‐A, formaldehyde, and transition metal complexes of ethylenediamine [M(en)2] were synthesized by the reaction of bisphenol‐A, formaldehyde, and M(en)2 complex in alkaline medium, using M for Fe+3, Co+2, Ni+2, Cu+2, and Zn+2. The materials were characterized by elemental analysis, FTIR, UV–Vis, 1H‐NMR spectra, TGA, and magnetic susceptibility measurement. The geometry of the central metal ions was determined by electronic spectral studies and magnetic moment measurement. The MN and CN bonds were confirmed by the IR spectra of the polychelates. The 1H‐NMR spectra of the chelating resins confirmed polycondensation with well‐defined peaks for bridging methylene functions. Complexation studies with transition metal ions revealed effective coordination of the bisphenol‐A formaldehyde resin. The antimicrobial activities of these chelated resins were screened against E. coli, S. dysantrea (bacteria), and C. albicans, A. niger (fungi) by using agar well diffusion method. All the polymeric chelates show promising antimicrobial activities. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The effects of crystallization condition on the microstructure and thermal stability of istactic polypropylene nucleated by β‐form nucleating agent
Authors: Dong Mu , Guo Zhaoxia , Su Zhiqiang , Yu Jian
Published: August 2010

This article deals with the crystallization behaviors of original (prepared in a torque rheometer), DSC crystallization and mold crystallization (quenching and slow nonisothermal crystallization) of isotactic polypropylene (iPP) mixed with β‐form nucleating agent. The microstructure and thermal stability of these samples were investigated. The wide angle X‐ray diffraction (WAXD) results indicate that fast cooling is favorable for β‐form iPP formation. With slower cooling rate and higher concentration of nucleating agent, the lamellar thickness and stability of crystal0s were enhanced. Polarized optical microscopy (POM) and scanning electron microscopy (SEM) both showed that rapid crystallized samples gave rise to tiny spherulites, whereas under slow crystallization condition, nucleated samples could be fully developed in the form of dendritic or transcrystalline structures, depending on the nucleating agent concentration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Methylamino‐group‐modified hypercrosslinked polystyrene resin for the removal of phenol from aqueous solution
Authors: He Chunlian , Huang Jianhan , Liu Jianbo , Deng Linbei , Huang Kelong
Published: August 2010

Chemical modification was performed for macroporous crosslinked chloromethylated polystyrene. The obtained HJ‐K01 resin was used to remove phenol from aqueous solution, and its adsorption behaviors for phenol were compared with commercial Amberlite XAD‐4. The results indicate that methylamino groups were successfully uploaded onto the surface of the HJ‐K01 resin and the adsorption capacity of phenol onto the HJ‐K01 resin was much larger than that onto XAD‐4. Furthermore, the original phenol solution was suitable for the adsorption, the adsorption isotherms could be fitted by the Freundlich model, and its kinetic curves could be characterized by a pseudo‐second‐order rate equation. The fixed‐bed column adsorption demonstrated that the HJ‐K01 resin was an excellent resin for the removal of phenol. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of new anthracene‐based semiconducting polyethers
Authors: Hriz K. , Jaballah N. , Chemli M. , Fave J. L. , Majdoub M.
Published: August 2010

New anthracene‐based polyethers, anthracene/bisphenol A (An–BPA) and anthracene/fluorinated bisphenol A (An–BPAF), were synthesized and characterized. An–BPA and An–BPAF were fully soluble in common organic solvents and had number‐average molecular weights of 2580 and 3240, respectively. The optical properties of the polymers were investigated with ultraviolet–visible absorption and photoluminescence spectroscopy. Blue photoluminescence was observed in dilute solutions. In solid thin films, π–π interactions influenced the optical properties, and redshifted photoluminescence spectra were obtained; a green emission (504 nm) for An–BPAF and a green‐yellow emission (563 nm) for An–BPA were found. By cyclic voltammetry, the electrochemical band gap was estimated to be 2.72 and 3.05 eV for An–BPA and An–BPAF, respectively. Single‐layer diode devices of an indium tin oxide/polyether/aluminum configuration were fabricated and showed relatively low turn‐on voltages (3.5 V for An–BPA and 3.7 V for An–BPAF). © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Mechanical properties and multiscale characterization of nanofiber–alumina/epoxy nanocomposites
Authors: Brown G. M. , Ellyin F.
Published: August 2010

In contrast to the bulk of published nanocomposite studies, in this study we investigated the mechanical properties of alumina/epoxy nanocomposites manufactured with nanofillers having a fiber or whisker morphology. The article describes how ultrasonic dispersion and in situ polymerization were used to incorporate these 2–4 nm diameter fibers (with aspect ratios of 25–50) into a two‐part epoxy resin (Epon 826/Epicure 9551). The use of untreated and surface‐modified nanoparticles is contrasted, and improvements in both the tensile strength and modulus were observed at low filler loadings. Microstructural characterization of the nanocomposites via multiscale digital image analysis was used to interpret the mechanical properties and was found to be useful for direct comparison with other nanocomposites. In addition, superior performance was demonstrated through comparisons with numerous nanocomposites with nanoparticle reinforcements ranging from carbon nanofibers to spherical alumina particles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of pH Value on the aqueous precipitation copolymerization of acrylonitrile and vinyl acetate
Authors: Yao Zhen , Chen Huan‐Jin , Qin Yi‐Xiu , Cao Kun
Published: August 2010

The aqueous precipitation copolymerization of acrylonitrile (AN) and vinyl acetate (VAc) with NaClO3/NaHSO3 redox initiation system is carried out continuously in a 10L pilot‐plant reactor. The effects of pH value on ionization equilibrium of NaHSO3, polymerization rate, particle morphology, particle size and its distribution, molecular weight and its distribution have been investigated. It has been found that effective concentration of reductant H2SO3 increases with the decrease in pH value. On the other hand, deceasing pH value intensifies the coalescence among particles and then reduces diffusion rate of monomer and radicals into particles. Experimental data shows that the increase of pH value results in higher conversion. It indicates that pH value's effect on particle stability prevails its influence on effective concentration of the reductant. This conclusion is verified by the molecular weight, particle size, and particle morphology. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Development and physicochemical characterization of modified polymeric surfaces for bacterial adhesion
Authors: Anjum N. , Riquet A.‐M.
Published: August 2010

Radiation‐induced graft polymerization was used to modify the surfaces of polypropylene (PP) sheets for bacterial adhesion. For the experiments, two monomers were mixed: the quaternary ammonium salt (QAS) [2‐(methacryloyloxy)ethyl]trimethylammonium chloride and acrylic acid (AAc). The PP sheets were activated by electron‐beam radiation before the grafting reaction. Different AAc/QAS comonomer mixture ratios (50 : 10, 40 : 20, 30 : 30, 20 : 40, and 10 : 50) were used to determine the degree of grafting and to make the PP surfaces hydrophilic. The graft level increased with an increase in the percentage of AAc in the comonomer mixtures. Synergism was investigated during graft polymerization to quantify the poly(acrylic acid) and poly{[2‐(methacryloyloxy)ethyl]trimethylammonium chloride} graft fractions in the resulting graft copolymers. An approximation of the graft fractions was made with an analytical technique based on acid–base volumetric titration. The wettability of the modified surfaces was determined by the measurement of the water contact angles. The surfaces prepared with higher percentages of QAS in the comonomer mixtures had lower contact angles than those prepared with lower percentages of QAS. The presence of oxygen and nitrogen on the modified PP surfaces was investigated with X‐ray photoelectron spectroscopy. Structural changes in unmodified and modified PP were characterized with differential scanning calorimetry. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011