290 research outputs found
Quantitative EEG and Functional Outcome Following Acute Ischemic Stroke
Objective: To identify the most accurate quantitative electroencephalographic (qEEG) predictor(s) of unfavorable post-ischemic stroke outcome, and its discriminative capacity compared to already known demographic, clinical and imaging prognostic markers.
Methods: Prospective cohort of 151 consecutive anterior circulation ischemic stroke patients followed for 12 months. EEG was recorded within 72 h and at discharge or 7 days post-stroke. QEEG (global band power, symmetry, affected/unaffected hemisphere and time changes) indices were calculated from mean Fast Fourier Transform and analyzed as predictors of unfavorable outcome (mRS ≥ 3), at discharge and 12 months poststroke, before and after adjustment for age, admission NIHSS and ASPECTS.
Results: Higher delta, lower alpha and beta relative powers (RP) predicted outcome. Indices with higher discriminative capacity were delta-theta to alpha-beta ratio (DTABR) and alpha RP. Outcome models including either of these and other clinical/imaging stroke outcome predictors were superior to models without qEEG data. In models with qEEG indices, infarct size was not a significant outcome predictor.
Conclusions: DTAABR and alpha RP are the best qEEG indices and superior to ASPECTS in post-stroke outcome prediction. They improve the discriminative capacity of already known clinical and imaging stroke outcome predictors, both at discharge and 12 months after stroke.
Significance: qEEG indices are independent predictors of stroke outcome.info:eu-repo/semantics/publishedVersio
Interrater agreement on classification of photoparoxysmal electroencephalographic response
Our goal was to assess the interrater agreement (IRA) of photoparoxysmal response (PPR) using the classification proposed by a task force of the International League Against Epilepsy (ILAE), and a simplified classification system proposed by our group. In addition, we evaluated IRA of epileptiform discharges (EDs) and the diagnostic significance of the electroencephalographic (EEG) abnormalities. We used EEG recordings from the European Reference Network (EpiCARE) and Standardized Computer-based Organized Reporting of EEG (SCORE). Six raters independently scored EEG recordings from 30 patients. We calculated the agreement coefficient (AC) for each feature. IRA of PPR using the classification proposed by the ILAE task force was only fair (AC = 0.38). This improved to a moderate agreement by using the simplified classification (AC = 0.56; P = .004). IRA of EDs was almost perfect (AC = 0.98), and IRA of scoring the diagnostic significance was moderate (AC = 0.51). Our results suggest that the simplified classification of the PPR is suitable for implementation in clinical practice
LOCUS (LOng Covid–Understanding Symptoms, events and use of services in Portugal): A three-component study protocol
Approximately 10% of patients experience symptoms of Post COVID-19 Condition (PCC) after a SARS-CoV-2 infection. Akin acute COVID-19, PCC may impact a multitude of organs and systems, such as the cardiovascular, respiratory, musculoskeletal, and neurological systems. The frequency and associated risk factors of PCC are still unclear among both community and hospital settings in individuals with a history of COVID-19. The LOCUS study was designed to clarify the PCC's burden and associated risk factors. LOCUS is a multi-component study that encompasses three complementary building blocks. The "Cardiovascular and respiratory events following COVID-19" component is set to estimate the incidence of cardiovascular and respiratory events after COVID-19 in eight Portuguese hospitals via electronic health records consultation. The "Physical and mental symptoms following COVID-19" component aims to address the community prevalence of self-reported PCC symptoms through a questionnaire-based approach. Finally, the "Treating and living with Post COVID-19 Condition" component will employ semi-structured interviews and focus groups to characterise reported experiences of using or working in healthcare and community services for the treatment of PCC symptoms. This multi-component study represents an innovative approach to exploring the health consequences of PCC. Its results are expected to provide a key contribution to the optimisation of healthcare services design.info:eu-repo/semantics/publishedVersio
Post-Stroke Seizures Are Clinically Underestimated
Cerebrovascular disease is the leading cause of epilepsy in adults, although post-stroke seizures reported frequency is variable and few studies used EEG in their identification. To describe and compare EEG and clinical epileptic manifestations frequency in patients with an anterior circulation ischaemic stroke. Prospective study of acute anterior circulation ischaemic stroke patients, consecutively admitted to a Stroke Unit over 24 months and followed-up for 1 year. All patients underwent standardized clinical and diagnostic assessment. Seizure occurrence was clinically evaluated during hospitalization and by a telephone interview at 6 months and a clinical appointment at 12 months after stroke. Video-EEG was performed in the first 72 h (1st EEG), daily after the 1st EEG for the first 7 days after the stroke, or later if neurological worsening, at discharge, and at 12 months. 151 patients were included (112 men) with a mean age of 67.4 (11.9) years. In the 1st year after stroke, 38 patients (25.2%) had an epileptic seizure. During hospitalization, 27 patients (17.9%) had epileptiform activity (interictal or ictal) in the EEG, 7 (25.9%) of them electrographic seizures. During the first week after stroke, 22 (14.6%) patients had a seizure and 4 (2.6%) non-convulsive status epilepticus criteria. Five (22.7%) acute symptomatic seizures were exclusively electrographic. At least one remote symptomatic seizure occurred in 23 (16%) patients. In the first 7 days after stroke, more than one-fifth of patients with seizures had exclusively electrographic seizures. Without a systematic neurophysiological evaluation the frequency of post-stroke seizures are clinically underestimated.info:eu-repo/semantics/publishedVersio
Search for the Flavor-Changing Neutral Current Decay with the HERA-B Detector
We report on a search for the flavor-changing neutral current decay using events recorded with a dimuon trigger in
interactions of 920 GeV protons with nuclei by the HERA-B experiment. We find
no evidence for such decays and set a 90% confidence level upper limit on the
branching fraction .Comment: 17 pages, 4 figures (of which 1 double), paper to be submitted to
Physics Letters
Measurement of the J/Psi Production Cross Section in 920 GeV/c Fixed-Target Proton-Nucleus Interactions
The mid-rapidity (dsigma_(pN)/dy at y=0) and total sigma_(pN) production
cross sections of J/Psi mesons are measured in proton-nucleus interactions.
Data collected by the HERA-B experiment in interactions of 920 GeV/c protons
with carbon, titanium and tungsten targets are used for this analysis. The
J/Psi mesons are reconstructed by their decay into lepton pairs. The total
production cross section obtained is sigma_(pN)(J/Psi) = 663 +- 74 +- 46
nb/nucleon. In addition, our result is compared with previous measurements
Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms
The main aim of this work was to assess the influence
of the application of power ultrasound during blanching
of mushrooms (60 90 °C) on the shrinkage, heat transfer, and
quality parameters. Kinetics of mushroom shrinkage was
modeled and coupled to a heat transfer model for conventional
(CB) and ultrasonic-assisted blanching (UB). Cooking value
and the integrated residual enzymatic activity were obtained
through predicted temperatures and related to the hardness and
color variations of mushrooms, respectively. The application
of ultrasound led to an increase of shrinkage and heat transfer
rates, being this increase more intense at low process temperatures.
Consequently, processing time was decreased (30.7
46.0 %) and a reduction in hardness (25.2 40.8 %) and
lightness (13.8 16.8 %) losses were obtained. The best retention
of hardness was obtained by the UB at 60 °C, while to
maintain the lightness it was the CB and UB at 90 °C. For
enhancing both quality parameters simultaneously, a combined
treatment (CT), which consisted of a CB 0.5 min at
90 °C and then an UB 19.9min at 60 °C, was designed. In this
manner, compared with the conventional treatment at 60 °C,
reductions of 39.1, 27.2, and 65.5 % for the process time,
hardness and lightness losses were achieved, respectively.
These results suggest that the CT could be considered as an
interesting alternative to CB in order to reduce the processing
time and improve the overall quality of blanched mushrooms.The authors acknowledge the financial support of Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional de La Plata from Argentina, Erasmus Mundus Action 2-Strand 1 and EuroTango II Researcher Training Program and Ministerio de Economia y Competitividad (SPAIN) and the FEDER (project DPI2012-37466-CO3-03).Lespinard, A.; Bon Corbín, J.; Cárcel Carrión, JA.; Benedito Fort, JJ.; Mascheroni, RH. (2015). Effect of Ultrasonic-Assisted Blanching on Size Variation, Heat Transfer, and Quality Parameters of Mushrooms. Food and Bioprocess Technology. 8(1):41-53. https://doi.org/10.1007/s11947-014-1373-zS415381Aguirre, L., Frias, J. M., Barry-Ryan, C., & Grogan, H. (2009). Modelling browning and brown spotting of mushrooms (Agaricus bisporus) stored in controlled environmental conditions using image analysis. Journal of Food Engineering, 91, 280–286.Anantheswaran, R. C., Sastry, S. K., Beelman, R. B., Okereke, A., & Konanayakam, M. (1986). Effect of processing on yield, color, and texture of canned mushrooms. Journal of Food Science, 51(5), 1197–1200.Biekman, E. S. A., Kroese-Hoedeman, H. I., & Schijvens, E. P. H. M. (1996). Loss of solutes during blanching of mushrooms (Agaricus bisporus) as a result of shrinkage and extraction. Journal of Food Engineering, 28(2), 139–152.Biekman, E. S. A., van Remmen, H. H. J., Kroese-Hoedeman, H. I., Ogink, J. J. M., & Schijvens, E. P. H. M. (1997). Effect of shrinkage on the temperature increase in evacuated mushrooms (Agaricus bisporus) during blanching. Journal of Food Engineering, 33(1–2), 87–99.Brennan, M., Le Port, G., & Gormley, R. (2000). Post-harvest treatment with citric acid or hydrogen peroxide to extend the shelf life of fresh sliced mushrooms. Lebensmittel Wissenschaft und Technologie, 33, 285–289.Cárcel, J. A., Benedito, J., Rosselló, C., & Mulet, A. (2007). Influence of ultrasound intensity on mass transfer in apple immersed in a sucrose solution. Journal of Food Engineering, 78, 472–479.Cárcel, J. A., Benedito, J., Bon, J., & Mulet, A. (2007). High intensity ultrasound effects on meat brining. Meat Science, 76, 611–619.Cárcel, J. A., García-Pérez, J. V., Benedito, J., & Mulet, A. (2011). Food process innovation through new technologies: Use of ultrasound. Journal of Food Engineering, 110, 200–207.Cheng, X., Zhang, M., & Adhikari, B. (2013). The inactivation kinetics of polyphenol oxidase in mushroom (Agaricus bisporus) during thermal and thermosonic treatmemts. Ultrasonics Sonochemistry, 20, 674–679.Cliffe-Byrnes, V., & O’Beirne, D. (2007). Effects of gas atmosphere and temperature on the respiration rates of whole and sliced mushrooms (Agaricus bisporus): implications for film permeability in modified atmosphere packages. Journal of Food Science, 72, 197–204.Coskuner, Y., & Ozdemir, Y. (1997). Effects of canning processes on the elements content of cultivated mushrooms (Agaricus bisporus). Food Chemistry, 60(4), 559–562.Cruz, R. M. S., Vieira, M. C., Fonseca, S. C., & Silva, C. L. M. (2011). Impact of thermal blanching and thermosonication treatments on watercress (Nasturtium officinale) quality: thermosonication process optimisation and microstructure evaluation. Food and Bioprocess Technology, 4(7), 1197–1204.De Gennaro, L., Cavella, S., Romano, R., & Masi, P. (1999). The use of ultrasound in food technology I: inactivation of peroxidase by thermosonication. Journal of Food Engineering, 39, 401–407.De la Fuente, S., Riera, E., Acosta, V. M., Blanco, A., & Gallego-Juárez, J. A. (2006). Food drying process by power ultrasound. Ultrasonics, 44, 523–527.Delgado, A. E., Zheng, L., & Sun, D. W. (2009). Influence of ultrasound on freezing rate of immersion-frozen apples. Food and Bioprocess Technology, 2, 263–270.Devece, C., Rodríguez-López, J. N., Fenoll, J. T., Catalá, J. M., De los Reyes, E., & García-Cánovas, F. (1999). Enzyme inactivation analysis for industrial blanching applications: comparison of microwave, conventional, and combination heat treatments on mushroom polyphenoloxidase activity. Journal of Agricultural and Food Chemistry, 47(11), 4506–4511.Fernandes, F. A. N., & Rodrigues, S. (2007). Ultrasound as pre-treatment for drying of fruits: dehydration of banana. Journal of Food Engineering, 82, 261–267.Gabaldón-Leyva, C. A., Quintero-Ramos, A., Barnard, J., Balandrán-Quintana, R. R., Talamás-Abbud, R., & Jiménez-Castro, J. (2007). Effect of ultrasound on the mass transfer and physical changes in brine bell pepper at different temperatures. Journal of Food Engineering, 81, 374–379.Gallego-Juárez, J. A., Riera, E., De la Fuente, S., Rodríguez-Corral, G., Acosta-Aparicio, V. M., & Blanco, A. (2007). Application of high-power ultrasound for dehydration of vegetables: processes and devices. Drying Technology, 25, 1893–1901.Gamboa-Santos, J., Montilla, A., Soria, A. C., & Villamiel, M. (2012). Effects of conventional and ultrasound blanching on enzyme inactivation and carbohydrate content of carrots. European Food Research and Technology, 234, 1071–1079.García-Pérez, J. V., Cárcel, J. A., De la Fuente, S., & Riera, E. (2006). Ultrasonic drying of foodstuff in a fluidized bed. Parametric study. Ultrasonics, 44, 539–543.García-Pérez, J. V., Cárcel, J. A., Riera, E., Rosselló, C., & Mulet, A. (2012). Intensification of low-temperature drying by using ultrasound. Drying Technology, 30, 1199–1208.Gonzáles-Fandos, E., Giménez, M., Olarte, C., Sanz, S., & Simón, A. (2000). Effect of packaging conditions on the growth of microorganisms and the quality characteristics of fresh mushrooms (Agaricus bisporus) stored at inadequate temperatures. Journal of Applied Microbiology, 89, 624–632.Gormley, T. R. (1975). Chill storage of mushrooms. Journal of the Science of Food and Agriculture, 26, 401–411.Gouzi, H., Depagne, C., & Coradin, T. (2012). Kinetics and thermodynamics of thermal inactivation of polyfenol oxidase in an aqueous extract from Agaricus bisporus. Journal of Agricultural and Food Chemistry, 60, 500–506.Holdsworth, S. D. (1997). Thermal processing of packaged foods. London: Chapman Hall.Horžić, D., Jambrak, A. R., Belščak-Cvitanović, A., Komes, D., & Lelas, V. (2012). Comparison of conventional and ultrasound assisted extraction techniques of yellow tea and bioactive composition of obtained extracts. Food and Bioprocess Technology, 5, 2858–2870.Jambrak, A. R., Mason, T. J., Paniwnyk, L., & Lelas, V. (2007a). Ultrasonic effect on pH, electric conductivity, and tissue surface of button mushrooms, brussels sprouts and cauliflower. Czech Journal of Food Science, 25, 90–99.Jambrak, A. R., Mason, T. J., Paniwnyk, L., & Lelas, V. (2007b). Accelerated drying of button mushrooms, Brussels sprouts and cauliflower by applying power ultrasound and its rehydration properties. Journal of Food Engineering, 81, 88–97.Jasinski, E. M., Stemberger, B., Walsh, R., & Kilara, A. (1984). Ultra structural studies of raw and processed tissue of the major cultivated mushroom, Agaricus bisporus. Food Microstructure, 3, 191–196.Jolivet, S., Arpin, N., Wicher, H. J., & Pellon, G. (1998). Agaricus bisporus browning: a review. Mycological Research, 102, 1459–1483.Konanayakam, M., & Sastry, S. K. (1988). Kinetics of shrinkage of mushroom during blanching. Journal of Food Science, 53(5), 1406–1411.Kotwaliwale, N., Bakane, P., & Verma, A. (2007). Changes in textural and optical properties of oyster mushroom during hot air drying. Journal of Food Engineering, 78(4), 1207–1211.Leadley C. & Williams A. (2002). Power ultrasound—current and potential applications for food processing, Review No 32, Campden and Chorleywood Food Research Association.Lespinard, A. R., Goñi, S. M., Salgado, P. R., & Mascheroni, R. H. (2009). Experimental determination and modeling of size variation, heat transfer and quality indexes during mushroom blanching. Journal of Food Engineering, 92, 8–17.Lima, M., & Sastry, S. K. (1990). Influence of fluid rheological properties and particle location on ultrasound-assisted heat transfer between liquid and particles. Journal of Food Science, 55(4), 1112–1115.López, P., & Burgos, J. (1995). Peroxidase stability and reactivation after heat treatment and manothermosonication. Journal of Food Science, 60(3), 551–553.López, P., Sala, F. J., Fuente, J. L., Cardon, S., Raso, J., & Burgos, J. (1994). Inactivation of peroxidase lipoxigenase and phenol oxidase by manothermosonication. Journal of Agricultural and Food Chemistry, 42(2), 253–256.Mansfield, T. (1962). High temperature-short time sterilization. Proceedings First International Congress on Food Science and Technology, 4, 311–316.Mason T. J. (1998). Power ultrasound in food processing—the way forward. In M. J. W. Povey & T. J. Mason (Eds.), Ultrasound in Food Processing (pp 103–126). Blackie Academic & Professional, London.McArdle F. J. & Curwen D. (1962). Some factors influencing shrinkage of canned mushrooms. Mushroom Science, 5, 547–557.McArdle, F. J., Kuhn, G. D., & Beelman, R. B. (1974). Influence of vacuum soaking on yield and quality of canned mushrooms. Journal of Food Science, 39, 1026–1028.Mohapatra, D., Bira, Z. M., Kerry, J. P., Frías, J. M., & Rodrigues, F. A. (2010). Postharvest hardness and color evolution of White button mushrooms (Agaricus bisporus). Journal of Food Science, 75(3), 146–152.Ohlsson, T. (1980). Temperature dependence of sensory quality changes during thermal processing. Journal of Food Science, 45(4), 836–847.Ortuño, C., Martínez-Pastor, M., Mulet, A., & Benedito, J. (2013). Application of high power ultrasound in the supercritical carbon dioxide inactivation of Saccharomyces cerevisiae. Food Research International, 51, 474–481.Peralta-Jimenez, L., & Cañizares-Macías, M. P. (2012). Ultrasound-assisted method for extraction of theobromine and caffeine from cacao seeds and chocolate products. Food and Bioprocess Technology, 6, 3522–3529.Rodríguez-López, J. N., Fenoll, N. G., Tudela, J., Devece, C., Sánchez-Hernández, D., De los Reyes, D., et al. (1999). Thermal inactivation of mushroom polyphenoloxidase employing 2450 MHz microwave radiation. Journal of Agricultural Food Chemistry, 47, 3028–3035.Sala, F., Burgos, J., Condon, S., Lopez, P., & Raso, J. (1995). Effect of heat and ultrasound on microorganisms and enzymes. In G. W. Gould (Ed.), New methods of food preservation (1st ed., pp. 176–204). Glasgow: Blackie Academic and professional.Sanjuán, N., Hernando, I., Lluch, M. A., & Mullet, A. (2005). Effects of low temperature blanching on texture, microstructure and rehydration capacity of carrots. Journal of the Science of Food and Agriculture, 85, 2071–2076.Santos, M. V., & Lespinard, A. R. (2011). Numerical simulation of mushrooms during freezing using the FEM and an enthalpy—Kirchhoff formulation. Heat and Mass Transfer, 47, 1671–1683.Sastry, S. K., Beelman, R. B., & Speroni, J. J. (1985). A three-dimensional finite element model for thermally induced changes in foods: application to degradation of agaritine in canned mushrooms. Journal of Food Science, 50(5), 1293–1299.Sastry, S. K., Shen, G. Q., & Blaisdel, J. L. (1989). Effect of ultrasonic vibration on fluid-to-particule convective heat transfer coefficients. Journal of Food Science, 54(1), 229–230.Sensoy, I., & Sastry, S. K. (2004). Ohmic blanching of mushrooms. Journal of Food Process Engineering, 27(1), 1–15.Sheen, S., & Hayakawa, K. (1991). Finite difference simulation for heat conduction with phase change in an irregular food domain with volumetric change. International Journal of Heat and Mass Transfer, 34(6), 1337–1346.Simal, S., Benedito, J., Sanchez, E. S., & Rossello, C. (1998). Use of ultrasound to increase mass transport rates during osmotic dehydration. Journal of Food Engineering, 36, 323–336.Siró, I., Vén, C., Balla, C., Jónás, G., Zeke, I., & Friedrich, L. (2009). Application of an ultrasonic assisted curing technique for improving the diffusion of sodium chloride in porcine meat. Journal of Food Engineering, 91, 353–362.Soria, A. C., & Villamiel, M. (2010). Effect of ultrasound on the technological properties and bioactivity in foods: a review. Trends in Food Science and Technology, 21, 323–331.Verlinden, B. E., Yuksel, D., Baheri, M., De Baerdemaeker, J., & Van Dijk, C. (2000). Low temperature blanching effect on the changes in mechanical properties during subsequent cooking of three potato cultivars. International Journal of Food Science and Technology, 35, 331–340.Wu, C. M., Wu, J. L.-P., Chen, C.-C., & Chou, C.-C. (1981). Flavor recovery from mushroom blanching water. In G. Charalambous & G. Inglett (Eds.), The quality of foods and beverages: chemistry and technology, vol. 1. New York: Academic Press.Zivanovic, S., & Buescher, R. (2004). Changes in mushroom texture and cell wall composition affected by thermal processing. Journal of Food Science, 69, 44–48
Impact of Empiric Antimicrobial Therapy on Outcomes in Patients with Escherichia coli and Klebsiella pneumoniae Bacteremia: A Cohort Study
<p>Abstract</p> <p>Background</p> <p>It is unclear whether appropriate empiric antimicrobial therapy improves outcomes in patients with bacteremia due to <it>Escherichia coli </it>or <it>Klebsiella</it>. The objective of this study is to assess the impact of appropriate empiric antimicrobial therapy on in-hospital mortality and post-infection length of stay in patients with <it>Escherichia coli </it>or <it>Klebsiella </it>bacteremia while adjusting for important confounding variables.</p> <p>Methods</p> <p>We performed a retrospective cohort study of adult patients with a positive blood culture for <it>E. coli </it>or <it>Klebsiella </it>between January 1, 2001 and June 8, 2005 and compared in-hospital mortality and post-infection length of stay between subjects who received appropriate and inappropriate empiric antimicrobial therapy. Empiric therapy was defined as the receipt of an antimicrobial agent between 8 hours before and 24 hours after the index blood culture was drawn and was considered appropriate if it included antimicrobials to which the specific isolate displayed <it>in vitro </it>susceptibility. Data were collected electronically and through chart review. Survival analysis was used to statistically assess the association between empiric antimicrobial therapy and outcome (mortality or length of stay). Multivariable Cox proportional hazards models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI).</p> <p>Results</p> <p>Among 416 episodes of bacteremia, 305 (73.3%) patients received appropriate empiric antimicrobial therapy. Seventy-one (17%) patients died before discharge from the hospital. The receipt of appropriate antimicrobial agents was more common in hospital survivors than in those who died (p = 0.04). After controlling for confounding variables, there was no association between the receipt of appropriate empiric antimicrobial therapy and in-hospital mortality (HR, 1.03; 95% CI, 0.60 to 1.78). The median post-infection length of stay was 7 days. The receipt of appropriate antimicrobial agents was not associated with shortened post-infection length of stay, even after controlling for confounding (HR, 1.11; 95% CI 0.86 to 1.44).</p> <p>Conclusion</p> <p>Appropriate empiric antimicrobial therapy for <it>E. coli </it>and <it>Klebsiella </it>bacteremia is not associated with lower in-hospital mortality or shortened post-infection length of stay. This suggests that the choice of empiric antimicrobial agents may not improve outcomes and also provides data to support a randomized trial to test the hypothesis that use (and overuse) of broad-spectrum antibiotics prior to the availability of culture results is not warranted.</p
Increased Mobility of Metal Oxide Nanoparticles Due to Photo and Thermal Induced Disagglomeration
Significant advances have been made on our understanding of the fate and transport of engineered nanomaterials. One unexplored aspect of nanoparticle aggregation is how environmental stimuli such as light exposure and temperature variations affect the mobility of engineered nanoparticles. In this study, TiO2, ZnO, and CeO2 were chosen as model materials for investigating the mobility of nanoparticles under three external stimuli: heat, light and sonication. Sunlight and high power sonication were able to partially disagglomerate metal oxide clusters, but primary particles bonded by solid state necks were left intact. A cycle of temperature increase from 25°C to 65°C and then decrease back was found to disagglomerate the compact clusters in the heating phase and reagglomerate them as more open fractal structures during the cooling phase. A fractal model summing the pair-wise DLVO interactions between primary particles within two fractal agglomerates predicts weak attractions on the order of a few kT. Our study shows that common environmental stimuli such as light exposure or temperature variation can disagglomerate nanoparticle clusters and enhance their mobility in open waters. This phenomenon warrants attention since it is likely that metal oxide nanoparticles will experience these natural stimuli during their transport in the environment
Anthroponotic transmission of Cryptosporidium parvum predominates in countries with poorer sanitation - a systematic review and meta-analysis
Background: Globally cryptosporidiosis is one of the commonest causes of mortality in children under 24 months old and may be associated with important longterm health effects. Whilst most strains of Cryptosporidium parvum are zoonotic, C. parvum IIc is almost certainly anthroponotic. The global distribution of this potentially important emerging infection is not clear. Methods: We conducted a systematic review of papers identifying the subtype distribution of C. parvum infections globally. We searched PubMed and Scopus using the following key terms Cryptospor* AND parvum AND (genotyp* OR subtyp* OR gp60). Studies were eligible for inclusion if they had found C. parvum within their human study population and had subtyped some or all of these samples using standard gp60 subtyping. Pooled analyses of the proportion of strains being of the IIc subtype were determined using StatsDirect. Meta-regression analyses were run to determine any association between the relative prevalence of IIc and Gross Domestic Product, proportion of the population with access to improved drinking water and improved sanitation. Results: From an initial 843 studies, 85 were included in further analysis. Cryptosporidium parvum IIc was found in 43 of these 85 studies. Across all studies the pooled estimate of relative prevalence of IIc was 19.0% (95% CI: 12.9–25.9%), but there was substantial heterogeneity. In a meta-regression analysis, the relative proportion of all C. parvum infections being IIc decreased as the percentage of the population with access to improved sanitation increased and was some 3.4 times higher in those studies focussing on HIV-positive indivduals. Conclusions: The anthroponotic C. parvum IIc predominates primarily in lower-income countries with poor sanitation and in HIV-positive individuals. Given the apparent enhanced post-infectious virulence of the other main anthroponotic species of Cryptosporidium (C. hominis), it is important to learn about the impact of this subtype on human health
- …