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1.
Proc Natl Acad Sci U S A ; 121(2): e2307836121, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38170749

RESUMEN

High-harmonic generation from a gas target exhibits sharp spectral features and rapid phase variation near the Cooper minimum. By applying spectral filtering, shaped isolated attosecond pulses can be generated where the pulse is split into two in the time domain. Using such shaped extreme-ultraviolet (XUV) pulses, we theoretically study attosecond transient absorption (ATA) spectra of helium [Formula: see text] autoionizing state which is resonantly coupled to the [Formula: see text] dark state by a time-delayed infrared laser. Our simulations show that the asymmetric [Formula: see text] Fano line shape can be readily tuned into symmetric Lorentzian within the time delay of a few tens of attoseconds. Such efficient control is due to the destructive interference in the generation of the [Formula: see text] state when it is excited by a strongly shaped XUV pulse. This is to be compared to prior experiments where tuning the line shape of a Fano resonance would take tens of femtoseconds. We also show that the predicted ATA spectral line shape can be observed experimentally after propagation in a gas medium. Our results suggest that strongly shaped attosecond XUV pulses offer the opportunity for controlling and probing fine features of narrow resonances on the few-ten attoseconds timescale.

2.
Immunity ; 44(2): 422-37, 2016 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-26885862

RESUMEN

Dendritic cells (DCs) orchestrate complex membrane trafficking through an interconnected transportation network linked together by Rab GTPases. Through a tandem affinity purification strategy and mass spectrometry, we depicted an interactomic landscape of major members of the mammalian Rab GTPase family. When complemented with imaging tools, this proteomic analysis provided a global view of intracellular membrane organization. Driven by this analysis, we investigated dynamic changes to the Rab32 subnetwork in DCs induced by L. monocytogenes infection and uncovered an essential role of this subnetwork in controlling the intracellular proliferation of L. monocytogenes. Mechanistically, Rab32 formed a persistent complex with two interacting proteins, PHB and PHB2, to encompass bacteria both during early phagosome formation and after L. monocytogenes escaped the original containment vacuole. Collectively, we have provided a functional compartmentalization overview and an organizational framework of intracellular Rab-mediated vesicle trafficking that can serve as a resource for future investigations.


Asunto(s)
Células Dendríticas/inmunología , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Complejos Multiproteicos/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Aciltransferasas/metabolismo , Animales , Antiinfecciosos/uso terapéutico , Línea Celular , Biología Computacional , Contención de Riesgos Biológicos , Células Dendríticas/microbiología , Listeria monocytogenes/crecimiento & desarrollo , Listeriosis/tratamiento farmacológico , Ratones , Prohibitinas , Transporte de Proteínas , Proteínas Represoras/metabolismo , Vacuolas/metabolismo
3.
J Magn Reson Imaging ; 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38708838

RESUMEN

BACKGROUND: Chronic kidney disease (CKD) is associated with increased, and early cardiovascular disease risk. Changes in hemodynamics within the left ventricle (LV) respond to cardiac remodeling. The LV hemodynamics in nondialysis CKD patients are not clearly understood. PURPOSE: To use four-dimensional blood flow MRI (4D flow MRI) to explore changes in LV kinetic energy (KE) and the relationship between LV KE and LV remodeling in CKD patients. STUDY TYPE: Retrospective. POPULATION: 98 predialysis CKD patients (Stage 3: n = 21, stage 4: n = 21, and stage 5: n = 56) and 16 age- and sex-matched healthy controls. FIELD STRENGTH/SEQUENCE: 3.0 T/balanced steady-state free precession (SSFP) cine sequence, 4D flow MRI with a fast field echo sequence, T1 mapping with a modified Look-Locker SSFP sequence, and T2 mapping with a gradient recalled and spin echo sequence. ASSESSMENT: Demographic characteristics (age, sex, height, weight, blood pressure, heart rate, aortic regurgitation, and mitral regurgitation) and laboratory data (eGFR, Creatinine, hemoglobin, ferritin, transferrin saturation, potassium, and carbon dioxide bonding capacity) were extracted from patient records. Myocardial T1, T2, LV ejection fraction, end diastolic volume (EDV), end systolic volume, LV flow components (direct flow, delayed ejection, retained inflow, and residual volume) and KE parameters (peak systolic, systolic, diastolic, peak E-wave, peak A-wave, E/A ratio, and global) were assessed. The KE parameters were normalized to EDV (KEiEDV). Parameters were compared between disease stage in CKD patients, and between CKD patients and healthy controls. STATISTICAL TESTS: Differences in clinical and imaging parameters between groups were compared using one-way ANOVA, Kruskal Walls and Mann-Whitney U tests, chi-square test, and Fisher's exact test. Pearson or Spearman's correlation coefficients and multiple linear regression analysis were used to compare the correlation between LV KE and other clinical and functional parameters. A P-value of <0.05 was considered significant. RESULTS: Compared with healthy controls, peak systolic (24.76 ± 5.40 µJ/mL vs. 31.86 ± 13.18 µJ/mL), systolic (11.62 ± 2.29 µJ/mL vs. 15.27 ± 5.10 µJ/mL), diastolic (7.95 ± 1.92 µJ/mL vs. 13.33 ± 5.15 µJ/mL), peak A-wave (15.95 ± 4.86 µJ/mL vs. 31.98 ± 14.51 µJ/mL), and global KEiEDV (9.40 ± 1.64 µJ/mL vs. 14.02 ± 4.14 µJ/mL) were significantly increased and the KEiEDV E/A ratio (1.16 ± 0.67 vs. 0.69 ± 0.53) was significantly decreased in CKD patients. As the CKD stage progressed, both diastolic KEiEDV (10.45 ± 4.30 µJ/mL vs. 12.28 ± 4.85 µJ/mL vs. 14.80 ± 5.06 µJ/mL) and peak E-wave KEiEDV (15.30 ± 7.06 µJ/mL vs. 14.69 ± 8.20 µJ/mL vs. 19.33 ± 8.29 µJ/mL) increased significantly. In multiple regression analysis, global KEiEDV (ß* = 0.505; ß* = 0.328), and proportion of direct flow (ß* = -0.376; ß* = -0.410) demonstrated an independent association with T1 and T2 times. DATA CONCLUSION: 4D flow MRI-derived LV KE parameters show altered LV adaptations in CKD patients and correlate independently with T1 and T2 mapping that may represent myocardial fibrosis and edema. TECHNICAL EFFICACY: Stage 3.

4.
J Environ Manage ; 351: 119980, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38176386

RESUMEN

In the context of rapid global urbanization, the sustainable development of ecosystems should be considered. Accordingly, the Planetary Boundaries theory posits that reducing the amount of nitrogen and phosphorus pollutants entering bodies of water is necessary as excess levels may harm the aquatic environment and reduce in water quality. Thus, based on the long-term monitoring data of representative urban rivers in the Yangtze River Delta region, we evaluated the nitrogen and phosphorus pollution of water bodies in different urbanization stages and further quantified the effect of urban forests on water quality improvement. The results showed that, with the continuous progression of urbanization, the proportion of impervious surface area increased, along with the levels of nitrogen and phosphorus pollution in water bodies. The critical period of water quality deterioration in urban rivers occurred during the medium urbanization level when the proportion of impervious surface area reached 55-65 %, and the probability of an abrupt increase in total nitrogen (TN) and total phosphorus (TP) concentration exceeded 95 %. However, increasing the area of urban forests during this period reduced TN pollution by 36.64 % and TP pollution by 49.03 %. The results of this study support the expansion of urban forests during the medium urbanization stage to improve water quality. Furthermore, our results provide a reference and theoretical basis for urban forest construction as a key aspect of the sustainable development of the urban ecosystem in the Yangtze River Delta and similar regions around world.


Asunto(s)
Contaminantes Químicos del Agua , Calidad del Agua , Ecosistema , Urbanización , Mejoramiento de la Calidad , Bosques , Nitrógeno/análisis , Fósforo/análisis , China , Monitoreo del Ambiente/métodos , Contaminantes Químicos del Agua/análisis
5.
Brief Bioinform ; 22(5)2021 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-34370020

RESUMEN

Recent advances in bioinformatics analyses have led to the development of novel tools enabling the capture and trajectory mapping of single-cell RNA sequencing (scRNAseq) data. However, there is a lack of methods to assess the contributions of biological pathways and transcription factors to an overall developmental trajectory mapped from scRNAseq data. In this manuscript, we present a simplified approach for trajectory inference of pathway significance (TIPS) that leverages existing knowledgebases of functional pathways and other gene lists to provide further mechanistic insights into a biological process. TIPS identifies key pathways which contribute to a process of interest, as well as the individual genes that best reflect these changes. TIPS also provides insight into the relative timing of pathway changes, as well as a suite of visualizations to enable simplified data interpretation of scRNAseq libraries generated using a wide range of techniques. The TIPS package can be run through either a web server or downloaded as a user-friendly GUI run in R, and may serve as a useful tool to help biologists perform deeper functional analyses and visualization of their single-cell data.


Asunto(s)
Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , RNA-Seq/métodos , Transducción de Señal/genética , Análisis de la Célula Individual/métodos , Linfocitos T CD8-positivos/metabolismo , Células Cultivadas , Humanos , Internet , Reproducibilidad de los Resultados , Factores de Tiempo
6.
Opt Express ; 31(26): 43732-43747, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-38178463

RESUMEN

We propose to generate vortex high harmonics in the extreme ultraviolet (XUV) with a controllable spatial profile by using a Bessel-Gaussian (BG) beam carrying a nonzero orbital angular momentum (OAM). Such BG beam has quite a different intensity profile at the focus compared to the generally used BG beam without carrying the OAM. We show that the BG beam is capable of generating single-ring structured high harmonics, which is quite different from an Laguerre-Gaussian (LG) beam with a similar intensity distribution at the laser focus. We reveal that favorable phase-matching conditions can be achieved off-axis and away from the laser focus because a single-atom intrinsic phase due to the short electron trajectory can be well compensated by a geometric phase of the BG beam. We thus give a general rule that vortex high harmonics with a single annular profile can be efficiently generated when a gas medium is located at 1.5zred to 2.0zred before or after the laser focus of the BG beam, here zred is a reduced length. We also show the validity of this rule when the BG beam carries a higher OAM. This work is expected to be useful for synthesizing attosecond vortex pulses.

7.
Opt Lett ; 48(14): 3673-3676, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37450722

RESUMEN

We investigate the role of the Porras factor (or laser focusing effect) on the macroscopic high-order harmonic generation (HHG) driven by a focused broadband few-cycle laser beam. By employing a non-adiabatic phase-matching analysis method, we reveal that phase mismatch due to the induced-dipole phase varies with the Porras factor, which is dominant in phase matching at low gas pressure. We also find that in a strongly ionized medium when gas pressure is high, the nonlinear propagation is dominated by a plasma effect such that the focusing effect is mitigated, resulting in similar poor phase matching of HHG regardless of the Porras factor. Our results are expected to assist experimentalists identifying optimal conditions for HHG using ultrashort laser pulses.

8.
Opt Express ; 30(26): 47942-47956, 2022 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-36558711

RESUMEN

Extreme-ultraviolet pulses of attosecond duration carrying orbital angular momentum (OAM) can be produced by spectrally filtering vortex high harmonics generated in a gas medium. Here we reveal that fractional high harmonics (FHHs) with non-integer OAM generated by a short duration Laguerre-Gaussian laser beam are origins for the change of helical attosecond pulse train (APT) with azimuthal angle. We show that these harmonics have gap and minimum structures in the annular intensity profile and discontinue phase distribution along azimuthal angle. And each FHH can be expressed as a superposition of OAM modes with integer topological charges. Features of FHH can be identified by coherently combining selected OAM modes. We also uncover that these features are formed after FHH is propagated in gas medium and in vacuum. We finally demonstrate that the generation of FHHs and the dependence of helical APTs on azimuthal angle are changed by varying the macroscopic condition.

9.
Opt Lett ; 46(20): 5137-5140, 2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34653134

RESUMEN

We identify optimal conditions for the generation and isolation of attosecond pulses in an overdriven ionized medium. In a high-pressure and highly ionized gas, the spatiotemporal wavefront rotation of a driving laser can be optimized, leading to complete spatial separation of successive attosecond bursts in the far field. The resulting isolated attosecond pulses (IAPs) are much more divergent such that they are spatially separated from the driving laser in the far field. We show that the time delay of near-field harmonic emission along the radial distance determines the divergence of the attosecond burst in the far field. The generated IAPs are phase matched upon propagation in the second half of the gas medium. Validity of the generation scheme is tested at different carrier-envelope phases for a few-cycle laser pulse and by synthesizing the fundamental and its second harmonic field for a long-duration pulse.

10.
Environ Geochem Health ; 43(10): 4299-4313, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33860411

RESUMEN

Pharmaceutically active compounds (PhACs) released into the environment have an adverse impact on the soil and water ecosystem as well as human health. Sorption of PhACs by soils and its potential modification through introduced DOM in the applied animal manure or treated wastewater (TWW) determines the mobility and environmental relevance of PhACs. Sulfadiazine, caffeine and atenolol were selected as target PhACs to investigate their sorption behaviors by five selected arable soils in the absence and presence of pig manure DOM. Sulfadiazine was least sorbed, followed by caffeine and atenolol according to the Freundlich sorption isotherm fit (soil average Kf [µg(1-n) mLn g-1] 4.07, 9.06, 18.92, respectively). The addition of manure DOM (31.34 mg C L-1) decreased the sorption of sulfadiazine and especially of caffeine and atenolol (average Kf 3.04, 6.17, 5.79, respectively). Freundlich sorption isotherms of the PhACs became more nonlinear in the presence of manure DOM (Freundlich exponent n changed from 0.74-1.40 to 0.62-1.12), implying more heterogeneous sorption of PhACs in soil-DOM binary systems. Sorption competition of DOM molecules with sulfadiazine and caffeine mostly contributed to their decreased soil sorption when DOM was present. In contrast, the formation of DOM-atenolol associates in the solution phase caused the largely decreased soil sorption of atenolol in the presence of DOM. It is suggested that DOM concentration (e.g., ≥ 60 mg C L-1) and its interaction with PhACs should be taken into consideration when assessing the environmental impact of land application of animal manure or irrigation with TWW.


Asunto(s)
Preparaciones Farmacéuticas , Contaminantes del Suelo , Adsorción , Animales , Atenolol , Cafeína , Ecosistema , Estiércol , Suelo , Contaminantes del Suelo/análisis , Sulfadiazina , Porcinos
11.
Infect Immun ; 88(4)2020 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-32041786

RESUMEN

Cellular membrane proteins are a critical part of the host defense mechanisms against infection and intracellular survival of Listeria monocytogenes The complex spatiotemporal regulation of bacterial infection by various membrane proteins has been challenging to study. Here, using mass spectrometry analyses, we depicted the dynamic expression landscape of membrane proteins upon L. monocytogenes infection in dendritic cells. We showed that Dynein light chain 1 (Dynll1) formed a persistent complex with the mitochondrial cytochrome oxidase Cox4i1, which is disturbed by pathogen insult. We discovered that the dissociation of the Dynll1-Cox4i1 complex is required for the release of mitochondrial reactive oxygen species and serves as a regulator of intracellular proliferation of Listeria monocytogenes Our study shows that Dynll1 is an inhibitor of mitochondrial reactive oxygen species and can serve as a potential molecular drug target for antibacterial treatment.


Asunto(s)
Dineínas Citoplasmáticas/metabolismo , Células Dendríticas/inmunología , Complejo IV de Transporte de Electrones/metabolismo , Listeria monocytogenes/inmunología , Listeriosis/inmunología , Mitocondrias/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Animales , Línea Celular , Dimerización , Listeria monocytogenes/crecimiento & desarrollo , Ratones , Modelos Biológicos , Unión Proteica
12.
J Mater Sci Mater Med ; 30(8): 89, 2019 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-31342178

RESUMEN

As a non-invasive biophysical therapy, electromagnetic fields (EMF) have been widely used to promote the healing of fractures. In the present study, hydroxyapatite/collagen I (HAC) loaded with rabbit bone marrow mesenchymal stem cells (MSCs) were cultured in a dynamic perfusion bioreactor and exposed to EMF of 15 Hz/1mT. Osteogenic differentiation of the seeded cells was analyzed through the evaluation of ALP activity and osteogenesis-related genes expression in vitro. The in vivo osteogenesis efficacy of the cell laden HAC constructs treated with/without EMF was evaluated through a rabbit femur condyle defect model. The results showed that EMF of 15 Hz/1mT could enhance the osteogenic differentiation of the cells seeded on HAC scaffold. Furthermore, the in vivo experiments demonstrated that EMF exposure could promote bone regeneration within the defect and bone integration between the graft and host bone. Taking together, the MSCs seeded HAC scaffold combined with EMF exposure could be a promising approach for bone tissue engineering.


Asunto(s)
Células de la Médula Ósea , Técnicas de Cultivo de Célula , Campos Electromagnéticos , Células Madre Mesenquimatosas , Osteogénesis/efectos de la radiación , Andamios del Tejido/química , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/fisiología , Células de la Médula Ósea/efectos de la radiación , Regeneración Ósea/fisiología , Regeneración Ósea/efectos de la radiación , Técnicas de Cultivo de Célula/instrumentación , Técnicas de Cultivo de Célula/métodos , Proliferación Celular/efectos de la radiación , Células Cultivadas , Fémur/citología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Células Madre Mesenquimatosas/efectos de la radiación , Osteogénesis/fisiología , Conejos , Ingeniería de Tejidos/instrumentación , Ingeniería de Tejidos/métodos , Microtomografía por Rayos X
13.
J Environ Sci (China) ; 64: 197-206, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29478640

RESUMEN

Soil contamination by diesel has been often reported as a result of accidental spillage, leakage and inappropriate use. Surfactant-enhanced soil flushing is a common remediation technique for soils contaminated by hydrophobic organic chemicals. In this study, soil flushing with linear alkylbenzene sulfonates (LAS, an anionic surfactant) was conducted for intact columns (15cm in diameter and 12cm in length) of diesel-contaminated farmland purple soil aged for one year in the field. Dynamics of colloid concentration in column outflow during flushing, diesel removal rate and resulting soil macroporosity change by flushing were analyzed. Removal rate of n-alkanes (representing the diesel) varied with the depth of the topsoil in the range of 14%-96% while the n-alkanes present at low concentrations in the subsoil were completely removed by LAS-enhanced flushing. Much higher colloid concentrations and larger colloid sizes were observed during LAS flushing in column outflow compared to water flushing. The X-ray micro-computed tomography analysis of flushed and unflushed soil cores showed that the proportion of fine macropores (30-250µm in diameter) was reduced significantly by LAS flushing treatment. This phenomenon can be attributed to enhanced clogging of fine macropores by colloids which exhibited higher concentration due to better dispersion by LAS. It can be inferred from this study that the application of LAS-enhanced flushing technique in the purple soil region should be cautious regarding the possibility of rapid colloid-associated contaminant transport via preferential pathways in the subsurface and the clogging of water-conducting soil pores.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Gasolina/análisis , Contaminación por Petróleo/análisis , Contaminantes del Suelo/química , Tensoactivos/química , Coloides/química , Porosidad , Suelo/química , Contaminantes del Suelo/análisis
14.
Bioelectromagnetics ; 38(2): 137-150, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27973686

RESUMEN

Optimal therapeutics for hyperthyroidism-induced osteoporosis are still lacking. As a noninvasive treatment, electromagnetic fields (EMF) have been proven to be effective for treating osteoporosis in non-hyperthyroidism conditions. We herein systematically evaluated the reduced effects of EMF on osteoporosis in a hyperthyroidism rat model. With the use of Helmholtz coils and an EMF stimulator, 15 Hz/1 mT EMF was generated. Forty-eight 5-month-old male Sprague-Dawley rats were randomly divided into four different groups: control, levothyroxine treated (L-T4), EMF exposure + levothyroxine (EMF + L-T4), and EMF exposure without levothyroxine administration (EMF). All rats were treated with L-T4 (100 mg/day) except those in control and EMF groups. After 12 weeks, the results obtained from bone mineral density analyses and bone mechanical measurements showed significant differences between L-T4 and EMF + L-T4 groups. Micro CT and bone histomorphometric analyses indicated that trabecular bone mass and architecture in distal femur and proximal tibia were augmented and restored partially in EMF + L-T4 group. In addition, bone thyroid hormone receptors (THR) expression of hyperthyroidism rats was attenuated in EMF + L-T4 group, compared to control group, which was not observed in L-T4 group. According to these results, we concluded that 15 Hz/1 mT EMF significantly inhibited bone loss and micro architecture deterioration in hyperthyroidism rats, which might occur due to reduced THR expression caused by EMF exposure. Bioelectromagnetics. 38:137-150, 2017. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Hipertiroidismo/complicaciones , Magnetoterapia , Osteoporosis/etiología , Osteoporosis/terapia , Animales , Densidad Ósea/efectos de la radiación , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/efectos de la radiación , Hipertiroidismo/sangre , Hipertiroidismo/orina , Masculino , Osteoclastos/patología , Osteoclastos/efectos de la radiación , Osteoporosis/metabolismo , Osteoporosis/fisiopatología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Hormona Tiroidea/genética , Tibia/metabolismo , Tibia/fisiopatología , Tibia/efectos de la radiación
15.
Environ Geochem Health ; 39(6): 1221-1243, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28455820

RESUMEN

Excessive transport of fine sediment, and its associated pollutants, can cause detrimental impacts in aquatic environments. It is therefore important to perform accurate sediment source apportionment to identify hot spots of soil erosion. Various tracers have been adopted, often in combination, to identify sediment source type and its spatial origin; these include fallout radionuclides, geochemical tracers, mineral magnetic properties and bulk and compound-specific stable isotopes. In this review, the applicability of these techniques to particular settings and their advantages and limitations are reviewed. By synthesizing existing approaches, that make use of multiple tracers in combination with measured changes of channel geomorphological attributes, an integrated analysis of tracer profiles in deposited sediments in lakes and reservoirs can be made. Through a multi-scale approach for fine sediment tracking, temporal changes in soil erosion and sediment load can be reconstructed and the consequences of changing catchment practices evaluated. We recommend that long-term, as well as short-term, monitoring of riverine fine sediment and corresponding surface and subsurface sources at nested sites within a catchment are essential. Such monitoring will inform the development and validation of models for predicting dynamics of fine sediment transport as a function of hydro-climatic and geomorphological controls. We highlight that the need for monitoring is particularly important for hilly catchments with complex and changing land use. We recommend that research should be prioritized for sloping farmland-dominated catchments.


Asunto(s)
Sedimentos Geológicos/química , Monitoreo del Ambiente/métodos , Agua Dulce/química , Modelos Teóricos , Suelo/química , Contaminantes del Suelo/análisis , Factores de Tiempo , Incertidumbre
16.
J Environ Sci (China) ; 62: 39-48, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29289291

RESUMEN

Understanding antibiotic biodegradation is important to the appreciation of their fate and removal from the environment. In this research an Isotope Ratio Mass Spectrometry (IRMS) method was developed to evaluate the extent of biodegradation of the antibiotic, sulphanilamide, in contaminated groundwater. Results indicted an enrichment in δ13C of 8.44‰ from -26.56 (at the contaminant source) to -18.12‰ (300m downfield of the source). These results confirm reductions in sulphanilamide concentrations (from 650 to 10mg/L) across the contaminant plume to be attributable to biodegradation (56%) vs. other natural attenuation processes, such as dilution or dispersion (42%). To understand the controls on sulphanilamide degradation ex-situ microcosms assessed the influence of sulphanilamide concentration, redox conditions and an alternative carbon source. Results indicated, high levels of anaerobic capacity (~50% mineralisation) to degrade sulphanilamide under high (263mg/L), moderate (10mg/L) and low (0.02mg/L) substrate concentrations. The addition of electron acceptors; nitrate and sulphate, did not significantly enhance the capacity of the groundwater to anaerobically biodegrade sulphanilamide. Interestingly, where alternative carbon sources were present, the addition of nitrate and sulphate inhibited sulphanilamide biodegradation. These results suggest, under in-situ conditions, when a preferential carbon source was available for biodegradation, sulphanilamide could be acting as a nitrogen and/or sulphur source. These findings are important as they highlight sulphanilamide being used as a carbon and a putative nitrogen and sulphur source, under prevailing iron reducing conditions.


Asunto(s)
Agua Subterránea/química , Sulfanilamidas/análisis , Contaminantes Químicos del Agua/análisis , Biodegradación Ambiental , Carbonato de Calcio , Sulfanilamida , Microbiología del Agua
17.
J Magn Reson Imaging ; 44(3): 620-32, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26880230

RESUMEN

PURPOSE: To determine the utility of intravoxel incoherent motion (IVIM) imaging in grading gliomas and compare IVIM perfusion metrics with arterial spin labeling (ASL)-derived cerebral blood flow (CBF). MATERIALS AND METHODS: Fifty-two patients with pathologically confirmed gliomas underwent IVIM and ASL imaging at 3.0T. IVIM perfusion-related diffusivity (D*), perfusion fraction (f), product of f and D*(f×D*), true diffusivity (D), and apparent diffusion coefficient (ADC) were obtained to distinguish glioma grades. The CBF derived from pseudocontinuous ASL within the solid tumor was compared and correlated with IVIM perfusion metrics for grading of gliomas. Values were also normalized to the contralateral normal-appearing white matter. Receiver-operating characteristic was performed to determine diagnostic efficiency. The reliability was estimated with intraclass coefficient, coefficient of variance, and Bland-Altman plots. RESULTS: IVIM perfusion metrics and CBF were significantly higher in the high-grade than the low-grade gliomas (P < 0.001), ADC and D were significantly lower in the high-grade than the low-grade gliomas (P < 0.001). f×D* differed significantly between grades II through IV (P < 0.05 for all). The other metrics showed significant difference between grade II and grade III (P < 0.05 for all). Area under the curve (AUC) was largest for f×D* in distinguishing high-grade from low-grade gliomas (AUC = 0.979, P < 0.001) and between grade II and grade III (AUC = 0.957, P < 0.001). f×D* improved diagnostic performance of CBF in grading gliomas and showed strong correlation with CBF (r = 0.696, P < 0.001). CONCLUSION: IVIM-derived metrics are promising biomarkers in preoperative grading gliomas. IVIM imaging may be an additive method to ASL and ADC for evaluating tumor perfusion and diffusion. J. Magn. Reson. Imaging 2016;44:620-632.


Asunto(s)
Neoplasias Encefálicas/patología , Neoplasias Encefálicas/fisiopatología , Imagen de Difusión por Resonancia Magnética/métodos , Glioma/patología , Glioma/fisiopatología , Neovascularización Patológica/patología , Neovascularización Patológica/fisiopatología , Algoritmos , Velocidad del Flujo Sanguíneo , Neoplasias Encefálicas/diagnóstico por imagen , Circulación Cerebrovascular , Femenino , Glioma/diagnóstico por imagen , Humanos , Aumento de la Imagen , Interpretación de Imagen Asistida por Computador , Imagenología Tridimensional , Angiografía por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Movimiento (Física) , Clasificación del Tumor , Neovascularización Patológica/diagnóstico por imagen , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Marcadores de Spin
18.
Eur Spine J ; 25(8): 2596-604, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27146808

RESUMEN

PURPOSE: Chin-brow vertical angle (CBVA) is very important in correction of thoracolumbar kyphotic deformity in ankylosing spondylitis (AS), especially for the patients with cervical ankylosis. In previous study, Suk et al. stated that the patients with CBVA between -10° and 10° had better horizontal gaze. Unfortunately, in our clinical practice, we found the patients with CBVA between -10° and 10° after surgery usually complained of difficulty in cooking, cleaning, desk working and the like, although they had excellent horizontal gaze. In other words, for the patients with cervical ankylosis, good horizontal gaze existed together with poor downward gaze. Then, which condition do the patients prefer? Is there a compromise solution that makes a better quality life possible for the patients? In this research, we studied AS patients with cervical ankylosis, aiming to investigate the optimal CBVA for deformity correction. METHODS: 25 AS thoracolumbar kyphotic patients with cervical ankylosis were studied, whose function and expectation of visual field related to life quality were assessed by questionnaire before and after surgery. Pre- and post-operative CBVA were obtained on lateral photos of the patients with free-standing posture, and 50 cases of CBVA were included, which were divided into six groups according to the angle irrespective of surgery (Group A, CBVA <0°; Group B, 0° ≤ CBVA < 10°; Group C, 10° ≤ CBVA < 20°; Group D, 20° ≤ CBVA < 30°; Group E, 30° ≤ CBVA < 40°; Group F, CBVA ≥ 40°). Kruskal-Wallis test was used to assess all the groups in terms of various items in the questionnaire, while Mann-Whitney test was used to assess every two groups. RESULTS: In overall evaluation, Group C (10°-20°) obtained the optimal expectation (p < 0.05); Group B, C and D (0°-30°) obtained better function (p < 0.05), and there was no significant difference between the 3 groups. In appearance, Group A, B and C (<20°) were better than the other groups both in function and expectation (p < 0.05), without dramatic difference among the three groups. In outdoor activities, Group A, B, C and D (<30°) were better in most of the items (p < 0.05). In indoor activities, Group C and D (10-30°) were much better (p < 0.05). CONCLUSION: AS thoracolumbar kyphotic patients with cervical ankylosis had the best satisfaction when 10° ≤ CBVA < 20°.


Asunto(s)
Mentón/fisiología , Cifosis , Postura/fisiología , Espondilitis Anquilosante , Adulto , Estudios de Cohortes , Femenino , Humanos , Cifosis/epidemiología , Cifosis/fisiopatología , Cifosis/cirugía , Masculino , Calidad de Vida , Espondilitis Anquilosante/epidemiología , Espondilitis Anquilosante/fisiopatología , Espondilitis Anquilosante/cirugía , Campos Visuales
19.
Int Orthop ; 40(6): 1227-31, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26907874

RESUMEN

AIM: The aim of the study was to investigate the feasibility of limited long-segment fusion for a special kind of scoliosis: degenerative lower lumbar scoliosis without severe thoracolumbar kyphosis. METHODS: A total of 43 patients with degenerative lower lumbar scoliosis who underwent spinal surgery at our hospital from June 2003 to September 2012 were included in this retrospective study. The apical vertebrae included L3 and L4, the end vertebra was L2 or L3, and the T10-L2 kyphosis angle was <20°. The limited long-segment fusion group (upper end vertebrae L2) included 19 patients, and the long-segment fusion group (upper end vertebrae T9-11) included 24 patients. The radiographic parameters and Oswestry disability index (ODI) scores were compared between the two groups pre-operatively and at the last follow-up evaluation. RESULTS: The differences in the lumbar Cobb angle, lumbar lordosis angle, pelvic tilt angle, sacral slope angle, T10-L2 kyphosis angle, proximal junctional kyphosis angle, and ODI scores between the two groups pre-operatively and at the last follow-up evaluation were not statistically significant (p > 0.05). The limited long-segment fusion group did not exhibit post-operative proximal junctional kyphosis. CONCLUSIONS: Limited long-segment fusion is effective for patients with degenerative lower lumbar scoliosis without severe thoracolumbar kyphosis.


Asunto(s)
Vértebras Lumbares/cirugía , Escoliosis/cirugía , Fusión Vertebral/métodos , Adulto , Estudios de Factibilidad , Femenino , Humanos , Cifosis/cirugía , Región Lumbosacra , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Periodo Posoperatorio , Estudios Retrospectivos , Vértebras Torácicas , Resultado del Tratamiento
20.
Int Orthop ; 40(6): 1247-52, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27068038

RESUMEN

PURPOSE: This study reports a new approach for percutaneous endoscopic lumbar iscectomy (PELD), especially for soft, highly down-migrated lumbar disc herniation. METHODS: Seven patients with soft, highly down-migrated lumbar disc herniation who underwent PELD via a translaminar approach under local anaesthesia from January 2013 to June 2015, including five patients who underwent failed PELD in other hospitals, were retrospectively analyzed. Clinical outcomes were evaluated according to pre-operative and post-operative visual analogue scale (VAS) scores, Oswestry disability index (ODI) scores and post-operative magnetic resonance imaging (MRI). RESULTS: The highly down-migrated lumbar disc herniation was completely removed by PELD via a translaminar approach in seven patients, as confirmed by post-operative MRI. Leg pain was eased after removal of the disc migrations. The mean follow-up duration was 9.8 (range, 6-14) months. The mean pre-operative VAS was 7.6 ± 0.8 (range, 6-9), which decreased to 3.1 ± 1.5 (range, 2-5) at one week post-operatively and to 1.3 ± 0.8 (range, 0-3) by the last follow-up visit. The mean pre-operative ODI was 61.6 (range, 46-84), which decreased to 16.3 (range, 10-28) at the one month post-operative follow-up and to 8.4 (range, 0-14) by the last follow-up visit. No recurrence was observed in any of the seven patients during the follow-up period. CONCLUSION: PELD via a translaminar approach could be a good alternative option for the treatment of soft, highly down-migrated lumbar disc herniation.


Asunto(s)
Discectomía Percutánea/métodos , Endoscopía/métodos , Desplazamiento del Disco Intervertebral/cirugía , Adulto , Anciano , Anestesia Local , Femenino , Estudios de Seguimiento , Humanos , Vértebras Lumbares/cirugía , Región Lumbosacra/cirugía , Masculino , Persona de Mediana Edad , Dolor/cirugía , Dimensión del Dolor , Estudios Retrospectivos , Resultado del Tratamiento
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