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BACKGROUND: The objectives of the present study were to (a) measure the prevalence of defecation symptoms in IBS, (b) investigate the relationship between stool consistency and defecation symptoms in IBS, and (c) investigate the association of defecation symptoms with health-related quality of life (HRQL) and self-reported stress in patients with IBS cared for in a primary health care setting. METHODS: Ten primary health care centres joined the study. 282 patients with IBS as well as 372 non-IBS controls filled in gastrointestinal symptom diaries prospectively for two weeks as well as the Perceived Stress Scale-14 (PSS14) and the EuroQol barometer to measure perceived stress and HRQL, respectively. RESULTS: Incomplete evacuation was present in 51% vs. 21% of the stools among the IBS patients and the non-IBS controls, respectively. The need to strain during defecation was existing in 41% vs. 33% of the stools for the IBS patients and the non-IBS controls, respectively. Urgency was experienced in 37% of the stools in the IBS patients compared with 18% of the stools in the non-IBS controls. Patients with IBS experienced in a significant higher degree of overlapping symptoms per stool (p < 0.001 to p = 0.007). The occurrence of all defecation symptoms in the same patient was related to decreased HRQL, and increased stress (p = 0.001 to p < 0.001). CONCLUSIONS: An overlap between IBS and symptoms from the anorectal region related to defecation was found in a primary health care population. Defecation symptoms are very common in primary care IBS-patients, it co-occurs with increased self-perceived stress, and decreased HRQL.
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Síndrome del Colon Irritable , Humanos , Síndrome del Colon Irritable/complicaciones , Síndrome del Colon Irritable/epidemiología , Síndrome del Colon Irritable/diagnóstico , Defecación , Calidad de Vida , Atención Primaria de SaludRESUMEN
Anisotropic two-dimensional layered materials with low-symmetry lattices have attracted increasing attention due to their unique orientation-dependent mechanical properties. Black arsenic (b-As), with the puckered structure, exhibits extreme in-plane anisotropy in optical, electrical, and thermal properties. However, experimental research on mechanical properties of b-As is very rare, although theoretical calculations predicted the exotic elastic properties of b-As, such as the anisotropic Young's modulus and negative Poisson's ratio. Herein, experimental observations on highly anisotropic elastic properties of b-As were demonstrated using our developed in situ tensile straining setup based on the effective microelectromechanical system. The cyclic and repeatable load-displacement curves proved that Young's modulus along the zigzag direction was â¼1.6 times greater than that along the armchair direction, while the anisotropic ratio of ultimate strain reached â¼2.5, attributed to the hinge structure in the armchair direction. This study could provide significant insights into the design of novel anisotropic materials and explore their potential applications in nanomechanics and nanodevices.
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2D magnetic materials are ideal to fabricate magneto-optical, magneto-electric, and data storage devices, which are proposed to be critical to the next generation of information technologies. Benefited from their labile structures, 2D perovskites are amenable for magnetic manipulation through structural optimization. In this work, 2D room-temperature ferromagnetic SrTiO3 is achieved through straining effect induced by supercritical carbon dioxide (SC CO2 ). According to experimental results, the cubic phase of SrTiO3 is converted to tetragonal with exposure of (110), (200), (111), and (211) planes over the SC CO2 treatment, leading to significant ferromagnetic enhancement. Theoretical calculations illustrate that over the conversion from cubic to tetragonal, the electronic structure of SrTiO3 is significantly modulated. Specifically, the spin density of planes of (200), (111), and (211) is enhanced, presumably due to the stabilization of the highest occupied molecular orbital over straining by SC CO2 , leading to magnetic optimizations. This work suggests that magnetic optimization can be achieved from SC CO2 -induced electronic structure modulation.
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The genotype and phenotype of acral melanoma are obviously different from UV-radiation-induced melanoma. Based on the clinical data, mechanical stimulation is believed to be a potential cause of acral melanoma. In this case, it is desirable to clarify the role of mechanical stimulation in the progression of acral melanoma. However, the pathological process of cyclic straining that stimulates acral melanoma is still unclear. In this study, the influence of cyclic straining on melanoma cell proliferation was analyzed by using a specifically designed cell culture system. In the results, cyclic straining could promote melanoma cell proliferation but was inefficient after the disruption of cytoskeleton organization. Therefore, the mechanotransduction mechanism of promoted proliferation was explored. Both myosin and actin polymerization were demonstrated to be related to cyclic straining and further influenced the morphogenesis of melanoma cells. Additionally, the activation of mechanosensing transcription factor YAP was related to regulatory morphogenesis. Furthermore, expression levels of melanoma-involved genes were regulated by cyclic straining and, finally, accelerated DNA synthesis. The results of this study will provide supplementary information for the understanding of acral melanoma.
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Melanoma , Neoplasias Cutáneas , Actinas/genética , Actinas/metabolismo , Proliferación Celular/genética , ADN , Humanos , Mecanotransducción Celular/fisiología , Melanoma/genética , Morfogénesis , Factores de Transcripción/metabolismo , Melanoma Cutáneo MalignoRESUMEN
Emulsified vegetable oil (EVO), as one of the novel green substrates, has been widely used in subsurface remediation. In these applications, the retention behavior of EVO presents a challenge to remediation efficiency as mechanism insights into the retention of EVO is limited. Herein, Brinell funnels experiments with X-ray microtomography (XMT) were conducted to examine the drainage and retention of nanoscale EVO in porous media, with a specific focus on investigating the impact of pore straining, grain surface roughness, and interfacial effects on Nano-EVO (NEVO) retention. This study demonstrated that the retention of NEVO in porous media is the synergistic result of pore straining, roughness wedging, and interface attachment. With the action of these effects, three residual states of NEVO, incorporating retention at porous ganglia, grain-grain contacts, and grain surface, were identified by XMT in porous media. After multiple periods of drainage and imbibition, the NEVO arrived at stable retention proportions of 46.3%, 72.2%, and 85.9% in three independent systems with coarse, medium, and fine sand as porous media, respectively. The interfacial effects, including the attachment of solid-phase and air-liquid interface, are confirmed as the dominant factors for the retention of NEVO in porous media, which contributed 35.63-47.33% of total retention for the conditions employed. Correspondingly, the contributions of pore straining and roughness wedging only ranged 3.78-24.06% and 3.87-9.94%, respectively. The consistency of the contributions between the actual measurement of XMT and computational evaluation further confirmed the rationality and reliability of the results. In such the dominant factor, interfacial tension, contact angle, and capillary radius play an essential role in NEVO retention, which could be reflected by capillary rise height. These findings advance our understanding on NEVO retention caused by substrate-media interaction and also offer a promising direction for subsurface remediation.
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Aceites de Plantas , Porosidad , Reproducibilidad de los ResultadosRESUMEN
AIMS: To determine terminology and methods for raising intra-abdominal pressure (IAP) currently used by clinicians to assess pelvic floor dysfunction (PFD) and to measure the effect of these maneuvers on IAP. METHODS: Three-hundred questionnaires were distributed at two scientific meetings in the United Kingdom to determine methods clinicians used to raise IAP and their perceptions of these methods. Twenty healthy volunteers were also recruited to measure the effect of two methods of raising IAP: Valsalva maneuver (VM) and bear down maneuver (BDM). IAP pressure was measured with rectal catheters connected to pressure sensors. The IAP was measured during each maneuver in both standing and supine positions. RESULTS: Maneuvers used in practice were cough (79%), BDM (60%), and VM (38%). 44% of clinicians felt patients found it difficult to raise their IAP. There was uncertainty among clinicians as to which method was the most effective in raising IAP and whether the different methods produced the same rise in IAP. On testing IAP in 20 healthy volunteers, median (interquartile range) IAP generated during BDM; 101 (59.1) cmH2 O was significantly higher than that generated during VM; 80.3 (43.6) cmH2 O (p < .0001). CONCLUSION: Clinicians varied widely in the maneuvers they used to raise patients' IAP to test for PFD and there was uncertainty about the maneuvers' effect on IAP. In healthy volunteers, BDM produced significantly higher IAP than VM. We recommend standardization of terminology and techniques used to raise IAP when assessing PFD, to ensure consistency of diagnosis and assessment of treatment outcomes.
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Trastornos del Suelo Pélvico/diagnóstico , Maniobra de Valsalva/fisiología , Femenino , Humanos , Presión , Encuestas y CuestionariosRESUMEN
Occupational kneeling and squatting are well-documented risk factors for knee disorders. A method using 3 wireless accelerometers to detect and discriminate kneeling and squatting during work were developed based on data from a semi-standardised laboratory protocol. The method was tested for validity under free-living working conditions. The developed method showed high sensitivity (88-99%) and specificity (98-99%) for detection of kneeling and squatting during the semi-standardised laboratory conditions. During free-living working conditions, kneeling showed very high sensitivity (94%) and specificity (99%), while squatting results were non-conclusive due to limited duration of squatting during the free-living working conditions. This method shows great promise for long-term technical measurement of kneeling and squatting during normal working conditions using wireless accelerometers. The method opens up possibilities for using technical measurements to provide valid exposure assessments and intervention evaluations of kneeling and squatting, as well as increased feasibility for technical measurements in large cohort studies. Practitioner summary: Quantification of kneeling and squatting during work is important for prevention, but limited by either imprecise or costly methods. This study developed and validated an inexpensive wireless accelerometer-based measurement method that can be used by practitioners and researchers for long-term measurements of kneeling and squatting during free-living working conditions.
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Acelerometría/instrumentación , Articulación de la Rodilla/fisiología , Postura , Carga de Trabajo , Adulto , Femenino , Humanos , Masculino , Enfermedades Profesionales/prevención & control , Exposición Profesional/prevención & control , Reproducibilidad de los Resultados , Tecnología InalámbricaRESUMEN
BACKGROUND: Transient global amnesia is reported to be caused by cerebral venous congestion. Internal jugular venous flow reversal in particular with the Valsalva maneuver leads to cerebral venous congestion. In addition, Valsalva maneuver can also induce subarachnoid hemorrhage. Transient global amnesia and subarachnoid hemorrhage might have common a pathophysiology in cerebral venous congestion. CASE PRESENTATION: We report here the case of a 57-year-old woman who twice experienced convexal subarachnoid hemorrhage just after straining at stool following an episode of transient global amnesia. Digital subtraction angiography showed left temporal congestion. Left jugular vein ultrasonography revealed reflux with the Valsalva maneuver only in acute phase, indicating transient cerebral venous congestion. CONCLUSIONS: Subarachnoid hemorrhage followed by transient global amnesia indicates a common factor between them. Transient venous congestion is discussed in order to explain this rare phenomenon.
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Amnesia Global Transitoria , Venas Cerebrales/fisiopatología , Hemorragia Subaracnoidea , Defecación , Femenino , Humanos , Persona de Mediana Edad , Maniobra de ValsalvaRESUMEN
AIMS: To assess the effects of the Valsalva manoeuvre versus straining on bladder neck (BN) and puborectalis muscle (PR) position, BN stiffness and pelvic floor muscle (PFM) activation in urinary incontinent women and healthy continent controls. METHODS: We recruited 17 continent and 85 incontinent women. A Microtip transducer measured urethral and vesical/abdominal pressures. A surface EMG electrode attached to a sponge was placed vaginally at the pelvic floor level. BN and PR movements were assessed with perineal ultrasound. Stiffness was calculated as the increase in vesical pressure per descent of BN and PR during manoeuvres. Women were standing and asked to perform a Valsalva against a closed mouth and glottis and thereafter to relax the PFM and strain as if defecating. To demonstrate a difference of 5 mm in PR descent between Valsalva and straining with a power of 80% and α = 0.05, 24 women were necessary. RESULTS: During Valsalva, 71% of continent and 76% of incontinent women demonstrated PFM activation, whereas during straining significantly fewer women activated the PFM (29% and 32%, respectively). During straining, BN and PR muscle descent was significantly greater and stiffness was lower than during Valsalva in both incontinent and continent women. CONCLUSION: Valsalva and straining are different tasks with different PFM activation patterns. The PF is stiffer with Valsalva resulting in better BN support whereas straining leads to more PR and BN descent. These terms should not be used interchangeably and women have to be instructed carefully to allow appropriate interpretation of data.
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Diafragma Pélvico/diagnóstico por imagen , Vejiga Urinaria/diagnóstico por imagen , Incontinencia Urinaria de Esfuerzo/fisiopatología , Maniobra de Valsalva/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Defecación , Electromiografía , Femenino , Humanos , Persona de Mediana Edad , Diafragma Pélvico/fisiología , Diafragma Pélvico/fisiopatología , Perineo , Postura , Presión , Ultrasonografía , Uretra , Vejiga Urinaria/fisiología , Vejiga Urinaria/fisiopatología , Incontinencia Urinaria/diagnóstico por imagen , Incontinencia Urinaria/fisiopatología , Incontinencia Urinaria de Esfuerzo/diagnóstico por imagen , VaginaRESUMEN
PURPOSE: The corticospinal responses to skill training may be different to strength training, depending on how the strength training is performed. It was hypothesised that the corticospinal responses would not be different following skill training and metronome-paced strength training (MPST), but would differ when compared with self-paced strength training (SPST). METHODS: Corticospinal excitability, short-interval intra-cortical inhibition (SICI) and strength and tracking error were measured at baseline and 2 and 4 weeks. Participants (n = 44) were randomly allocated to visuomotor tracking, MPST, SPST or a control group. RESULTS: MPST increased strength by 7 and 18%, whilst SPST increased strength by 12 and 26% following 2 and 4 weeks of strength training. There were no changes in strength following skill training. Skill training reduced tracking error by 47 and 58% at 2 and 4 weeks. There were no changes in tracking error following SPST; however, tracking error reduced by 24% following 4 weeks of MPST. Corticospinal excitability increased by 40% following MPST and by 29% following skill training. There was no change in corticospinal excitability following 4 weeks of SPST. Importantly, the magnitude of change between skill training and MPST was not different. SICI decreased by 41 and 61% following 2 and 4 weeks of MPST, whilst SICI decreased by 41 and 33% following 2 and 4 weeks of skill training. Again, SPST had no effect on SICI at 2 and 4 weeks. There was no difference in the magnitude of SICI reduction between skill training and MPST. CONCLUSIONS: This study adds new knowledge regarding the corticospinal responses to skill and MPST, showing they are similar but different when compared with SPST.
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Destreza Motora , Fuerza Muscular , Acondicionamiento Físico Humano/métodos , Tractos Piramidales/fisiología , Adulto , Femenino , Humanos , Contracción Isométrica , Masculino , Corteza Motora/fisiología , Inhibición NeuralRESUMEN
A precise evaluation of bacteria transport and mathematical investigations are useful for best management practices in agroecosystems. In this study, using laboratory experiments and modeling approaches, we assess the transport of bacteria released from three types of manure (cow, sheep, and poultry) to find the importance of the common manures in agricultural activities in soil and water pollution. Thirty six intact soil columns with different textures (sandy, loamy, and silty clay loam) were sampled. Fecal coliform leaching from layers of the manures on the soil surface was conducted under steady-state saturated flow conditions at 20 °C for up to four Pore Volumes (PVs). Separate leaching experiments were conducted to obtain the initial concentrations of bacteria released from the manures (Co). Influent (Co) and effluent (C) bacteria concentrations were measured by the plate-count method and the normalized concentrations (C/C0) were plotted versus PV representing the breakthrough curves (BTCs). Transport parameters were predicted using the attachment/detachment model (two-kinetic site) in HYDRUS-1D. Simulations fitted well the experimental data (R2 = 0.50-0.96). The attachment, detachment, and straining coefficients of bacteria were more influenced by the soils treated with cow manure compared to the sheep and poultry manures. Influent curves of fecal coliforms from the manures (leached without soil) illustrated that the poultry manure had the highest potential to pollute the effluent water from the soils in term of concentration, but the BTCs and simulated data related to the treated soils illustrated that the physical shape of cow manure was more important to both straining and detachment of bacteria back into the soil solution. Detachment trends of bacteria were observed through loam and silty clay loam soils treated with cow manure compared to the cow manure enriched sandy soil. We conclude that management strategies must specifically minimize the effect of fecal coliform concentrations before field application, especially for the combination of poultry and cow manures, which has higher solubility and tailing behavior, respectively. Interestingly, the addition of sheep manure with all three soils had the lowest mobilization of bacteria. We also suggest studying the chemistry of soil solution affected by manures to present all relevant information which affect bacterial movement through soils during leaching.
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Agricultura , Estiércol , Contaminantes del Suelo , Animales , Bovinos , Femenino , Ovinos , SueloRESUMEN
The effects of porous media grain size distribution on the transport and deposition of polydisperse suspended particles under different flow velocities were investigated. Selected Kaolinite particles (2-30µm) and Fluorescein (dissolved tracer) were injected in the porous media by step input injection technique. Three sands filled columns were used: Fine sand, Coarse sand, and a third sand (Mixture) obtained by mixing the two last sands in equal weight proportion. The porous media performance on the particle removal was evaluated by analysing particles breakthrough curves, hydro-dispersive parameters determined using the analytical solution of convection-dispersion equation with a first order deposition kinetics, particles deposition profiles, and particle-size distribution of the recovered and the deposited particles. The deposition kinetics and the longitudinal hydrodynamic dispersion coefficients are controlled by the porous media grain size distribution. Mixture sand is more dispersive than Fine and Coarse sands. More the uniformity coefficient of the porous medium is large, higher is the filtration efficiency. At low velocities, porous media capture all sizes of suspended particles injected with larger ones mainly captured at the entrance. A high flow velocity carries the particles deeper into the porous media, producing more gradual changes in the deposition profile. The median diameter of the deposited particles at different depth increases with flow velocity. The large grain size distribution leads to build narrow pores enhancing the deposition of the particles by straining.
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Filtración/métodos , Hidrodinámica , Cinética , Fenómenos Mecánicos , Modelos Químicos , Tamaño de la Partícula , Porosidad , Dióxido de SilicioRESUMEN
Silver nanowires are promising components of flexible electronics such as interconnects and touch displays. Despite the expected cyclic loading in these applications, characterization of the cyclic mechanical behavior of chemically synthesized high-quality nanowires has not been reported. Here, we combine in situ TEM tensile tests and atomistic simulations to characterize the cyclic stress-strain behavior and plasticity mechanisms of pentatwinned silver nanowires with diameters thinner than 120 nm. The experimental measurements were enabled by a novel system allowing displacement-controlled tensile testing of nanowires, which also affords higher resolution for capturing stress-strain curves. We observe the Bauschinger effect, that is, asymmetric plastic flow, and partial recovery of the plastic deformation upon unloading. TEM observations and atomistic simulations reveal that these processes occur due to the pentatwinned structure and emerge from reversible dislocation activity. While the incipient plastic mechanism through the nucleation of stacking fault decahedrons (SFDs) is fully reversible, plasticity becomes only partially reversible as intersecting SFDs lead to dislocation reactions and entanglements. The observed plastic recovery is expected to have implications to the fatigue life and the application of silver nanowires to flexible electronics.
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OBJECTIVE: Guidelines for the management of irritable bowel syndrome (IBS) encourage a positive diagnosis, but some evidence suggests organic disease may be missed unless investigations are performed. We examined yield of colonoscopy in a cohort of secondary care patients meeting criteria for IBS. MATERIALS AND METHODS: Demographic data, symptoms and findings at colonoscopy were recorded prospectively in consecutive, unselected adults with gastrointestinal (GI) symptoms compatible with IBS according to the Rome III criteria. Prevalence of organic GI disease was compared between those meeting criteria for IBS, according to the presence or absence of co-existent alarm features, and by IBS subtype. RESULTS: A total of 559 patients met Rome III criteria for IBS, of whom 423 reported ≥1 alarm feature and 136 none. There was a significantly higher prevalence of organic GI disease among those reporting alarm features (117 [27.7%]), compared with those without (21 [15.4%]) (p = 0.002). In the latter group of 136 patients, Crohn's disease was the commonest finding (10 [7.4%] subjects), followed by coeliac disease (4 [2.9%] subjects), and microscopic colitis (3 [2.2%] subjects). Regardless of presence or absence of alarm features, patients with constipation-predominant IBS were less likely to exhibit organic GI disease than those with diarrhea-predominant or mixed IBS (12.7% vs. 32.1% and 23.8%, p = 0.006). CONCLUSIONS: One in six patients with symptoms compatible with IBS without alarm features in this selected group exhibited organic GI disease following investigation. Assessment of alarm features in a comprehensive history is vital to reduce diagnostic uncertainty that can surround IBS.
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Colonoscopía/métodos , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/epidemiología , Síndrome del Colon Irritable/diagnóstico , Dolor Abdominal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Estudios Transversales , Diagnóstico Diferencial , Diarrea , Femenino , Enfermedades Gastrointestinales/patología , Humanos , Síndrome del Colon Irritable/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Adulto JovenRESUMEN
Research and development of two-dimensional transition metal dichalcogenides (TMDC) (e.g., molybdenum disulfide [MoS2]) in electronic, optical, and catalytic applications has been growing rapidly. However, there is little known regarding the behavior of these particles once released into aquatic environments. Therefore, an in-depth study regarding the fate and transport of two popular types of MoS2 nanomaterials, lithiated (MoS2-Li) and Pluronic PF-87 dispersed (MoS2-PL), was conducted in saturated porous media (quartz sand) to identify which form would be least mobile in aquatic environments. The electrokinetic properties and hydrodynamic diameters of MoS2 as a function of ionic strength and pH were determined using a zeta potential analyzer and dynamic light scattering techniques. Results suggest that the stability is significantly decreased beginning at 10 and 31.6 mM KCl, for MoS2-PL and MoS2-Li, respectively. Transport study results from breakthrough curves, column dissections, and release experiments suggest that MoS2-PL exhibits a greater affinity to be irreversibly bound to quartz surfaces as compared with the MoS2-Li at a similar ionic strength. Derjaguin-Landau-Verwey-Overbeek theory was used to help explain the unique interactions between the MoS2-PL and MoS2-Li surfaces between particles and with the quartz collectors. Overall, the results suggest that the fate and transport of MoS2 is dependent on the type of MoS2 that enters the environment, where MoS2-PL will be least mobile and more likely be deposited in porous media from pluronic-quartz interactions, whereas MoS2-Li will travel greater distances and have a greater tendency to be remobilized in sand columns.
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Determining the role of micro-nanobubbles (MNBs) in controlling the risk posed by pathogens to soil and groundwater during reclaimed water irrigation requires clarification of the mechanism of how MNBs block pathogenic bacteria. In this study, real-time bioluminescence imaging was used to investigate the effects of MNBs on the transport and spatiotemporal distribution of bioluminescent Escherichia coli 652T7 strain in porous media. The presence of MNBs significantly increased the retention of bacteria in the porous media, decreasing the maximum relative effluent concentration (C/C0) by 78 % from 0.97 (without MNBs) to 0.21 (with MNBs). The results suggested that MNBs provided additional sites at the air-water interface (AWI) for bacterial attachment and acted as physical obstacles to reduce bacterial passage. These effects varied with environmental conditions such as solution ionic strength and pore water velocity. The results indicated that MNBs enhanced electrostatic attachment of bacteria at the AWI and their mechanical straining in pores. This study suggests that adding MNBs in pathogen-containing water is an effective measure for increasing filtration efficiency and reducing the risk of pathogenic contamination during agricultural irrigation.
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Escherichia coli , Porosidad , Microbiología del AguaRESUMEN
Information about the influence of surface charges on nanoplastics (NPLs) transport in porous media, the influence of NPL concentrations on porous media retention capacities, and changes in porous media adsorption capacities in the presence of natural water components are still scarce. In this study, laboratory column experiments are conducted to investigate the transport behavior of positively charged amidine polystyrene (PS) latex NPLs and negatively charged sulfate PS latex NPLs in quartz sand columns saturated with ultrapure water and Geneva Lake water, respectively. Results obtained for ultrapure water show that amidine PS latex NPLs have more affinity for negatively charged sand surfaces than sulfate PS latex NPLs because of the presence of attractive electrical forces. As for the Geneva Lake water, under natural conditions, both NPL types and sand are negatively charged. Therefore, the presence of repulsion forces reduces NPL's affinity for sand surfaces. The calculated adsorption capacities of sand grains for the removal of both types of NPLs from both types of water are oscillating around 0.008 and 0.004 mg g-1 for NPL concentrations of 100 and 500 mg L-1, respectively. SEM micrography shows individual NPLs or aggregates attached to the sand and confirms the limited role of the adsorption process in NPL retention. The important NPL retention, especially in the case of negatively charged NPLs, in Geneva Lake water-saturated columns is related to heteroaggregate formation and their further straining inside narrow pores. The presence of DOM and metal cations is then crucial to trigger the aggregation process and NPL retention.
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BACKGROUND: Northeast farmworkers are a small, widely dispersed, and isolated population. Little is known about their occupational injury and illness risk. METHODS: Researchers conducted chart reviews in migrant health centers across the Northeast, and calculated incidence-density for agricultural morbidity based on a new method for estimating total worker hours at risk, and adjusting for cases seen at other sources of care. RESULTS: An estimated annual average of 1,260 cases translated to an incidence of 30.27 per 10,000 worker weeks, (12.7 per 100 FTEs). Straining/spraining events (56% cases) was the most common occurrence (16.8 per 10,000 worker weeks), and lifting (21.5% cases) was the leading contributing factor. Incidence by crop category ranged from 12.95 (ground crop) to 29.69 (bush crop) per 10,000 weeks. Only 2.8% filed for Workers' Compensation. CONCLUSION: The predominance of straining/spraining events affecting the back, and their association with lifting suggests that Northeastern farmworker occupational health programs should focus on ergonomics, and specifically on safe lifting.
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Enfermedades de los Trabajadores Agrícolas/epidemiología , Agricultura , Traumatismos Ocupacionales/epidemiología , Esguinces y Distensiones/epidemiología , Migrantes , Adolescente , Adulto , Anciano , Enfermedades de los Trabajadores Agrícolas/etiología , Femenino , Humanos , Incidencia , Masculino , Mid-Atlantic Region/epidemiología , Persona de Mediana Edad , New England/epidemiología , Traumatismos Ocupacionales/etiología , Vigilancia de la Población , Esguinces y Distensiones/etiología , Adulto JovenRESUMEN
Straining of PVA/PE and PVA/PP blends (70:30) is monitored by small-angle x-ray scattering (SAXS). Sheet-extruded films with different predraw ratio are investigated. The discrete SAXS of predrawn samples originates from polyolefin nanofibrils inside of polyolefin microfibrils immersed in a PVA matrix. PE nanofibrils deform less than the macroscopic strain without volume change. PP nanofibrils experience macroscopic strain. They lengthen but their diameter does not decrease. This is explained by strain-induced crystallization of PP from an amorphous depletion shell around the core of the nanofibril. The undrawn PVA/PE film exhibits isotropic semicrystalline nanostructure. Undrawn PVA/PP holds PP droplets containing oriented stacks of semicrystalline PP like neat precursors of hard-elastic thermoplasts. Respective predrawn films are softer than the undrawn material, indicating conversion into the hard-elastic state. Embedding of the polyolefin significantly retards neck formation. The polyolefin microfibrils can easily be extracted from the water-soluble matrix.
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Introduction Constipation is a common condition in children, affecting almost one-third of the population at some point in childhood across the world. Functional constipation is the most common cause, with no clear etiology. From April 25, 2014, through October 16, 2015, the water source for the city of Flint residents was untreated Flint River water, which resulted in lead-contaminated drinking water. Lead poisoning has been associated with constipation and has multisystem sequelae, including neurological, muscular, and hematological impacts. Children may be especially vulnerable to this with their higher water intake-to-body weight ratio. There has been no previous study examining the possible relationship between the Flint water crisis and constipation in children. In our study, we aimed to see if the increased lead level in the water had any effect on constipation in children in Flint. Methods We included all children seen and diagnosed with constipation at Hurley Medical Center's Pediatric Gastrointestinal (GI) Clinic. We included only children seen in 2013 (pre-water crisis) and 2017 (post-water crisis). Children with chronic neurologic disorders, celiac disease, hypothyroidism, diabetes, Hirschsprung's disease, short bowel syndrome, and gastrointestinal surgeries were excluded. We looked at the age of presentation, associated symptoms, medications used, need for hospital admission or emergency department (ED) visits, and improvements at follow-up. Results A total of 79 patients were included in the study. There were 29 patients from 2013 and 50 patients from 2017 (post-lead exposure period). The rate of constipation referrals to the GI clinic for the Flint population of children was significantly higher in 2017 (p=0.001). The most common associated symptom was abdominal pain in both groups. Straining was more prominent in the 2017 group (60%) compared to the 2013 group (34.5%, p=0.029). There was no clinical or statistically significant difference between the groups noted in abdominal pain, blood in the stool, fecal incontinence, vomiting, history of urinary tract infection (UTI), abdominal distention, or stool impaction. Conclusions The number of patients referred to Hurley's Pediatric GI Clinic for constipation increased after the lead water crisis in Flint. Moreover, straining has significantly increased in post-lead exposure compared to pre-lead exposure. There was no clinical or statistically significant difference noted in abdominal pain, blood in the stool, fecal incontinence, vomiting, history of UTI, abdominal distention, or stool impaction between both groups. A larger study would need to be done to confirm these findings, rule out other cofactors, and look into minerals in water and their effect on intestine innervations.