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Previous studies along the banks of the tidal Meghna River of the Ganges-Brahmaputra-Meghna Delta demonstrated the active sequestration of dissolved arsenic (As) on newly formed iron oxide minerals (Fe(III)-oxides) within riverbank sands. The sand with high solid-phase As (>500 mg/kg) was located within the intertidal zone where robust mixing occurs with oxygen-rich river water. Here we present new evidence that upwelling groundwater through a buried silt layer generates the dissolved products of reductive dissolution of Fe(III)-oxides, including As, while mobilization of DOC by upwelling groundwater prevents their reconstitution in the intertidal zone by lowering the redox state. A three end-member conservative mixing model demonstrated mixing between riverbank groundwater above the silt layer, upwelling groundwater through the silt layer, and river water. An electrochemical mass balance model confirmed that Fe(III)-oxides were the primary electron acceptor driving the oxidation of DOC sourced from sediment organic carbon in the silt. Thus, the presence of an intercalating silt layer in the riverbanks of tidal rivers can represent a biogeochemical hotspot of As release while preventing its retention in the hyporheic zone.
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This manuscript describes skeletal isomerization strategies to install one to four quaternary germanium atoms in the sila-adamantane core, in a cluster analogy to precision germanium doping in silicon-germanium alloys. The first strategy embodies an inorganic variant of single-atom skeletal editing, where we use a sila-Wagner-Meerwein bond shift cascade to exchange a peripheral Ge atom with a core Si atom. We can install up to four Ge atoms at the quaternary diamondoid centers based on controlling the SixGey stoichiometry of our precursor. We find that bridgehead Ge centers can be selectively functionalized over bridgehead Si centers in SiGe adamantanes; we use this chemistry in conjunction with scanning tunneling microscopy break-junction (STM-BJ) measurements to show that Si8Ge2 adamantane wires give a 60% increase in single-molecule conductance compared with Si10 adamantanes. These studies describe the first quantum transport measurements in sila-diamondoid structures, and demonstrate how main-chain Ge doping can be used to increase electronic transmission in sila-diamondoid-based molecular wires.
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Hyporheic zones (HZs)âzones of groundwater-surface water mixingâare hotspots for dissolved organic matter (DOM) and nutrient cycling that can disproportionately impact aquatic ecosystem functions. However, the mechanisms affecting DOM metabolism through space and time in HZs remain poorly understood. To resolve this gap, we investigate a recently proposed theory describing trade-offs between carbon (C) and nitrogen (N) limitations as a key regulator of HZ metabolism. We propose that throughout the extent of the HZ, a single process like aerobic respiration (AR) can be limited by both DOM thermodynamics and N content due to highly variable C/N ratios over short distances (centimeter scale). To investigate this theory, we used a large flume, continuous optode measurements of dissolved oxygen (DO), and spatially and temporally resolved molecular analysis of DOM. Carbon and N limitations were inferred from changes in the elemental stoichiometric ratio. We show sequential, depth-stratified relationships of DO with DOM thermodynamics and organic N that change across centimeter scales. In the shallow HZ with low C/N, DO was associated with the thermodynamics of DOM, while deeper in the HZ with higher C/N, DO was associated with inferred biochemical reactions involving organic N. Collectively, our results suggest that there are multiple competing processes that limit AR in the HZ. Resolving this spatiotemporal variation could improve predictions from mechanistic models, either via more highly resolved grid cells or by representing AR colimitation by DOM thermodynamics and organic N.
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Ecosistema , Agua Subterránea , Carbono/metabolismo , Nitrógeno/análisis , Agua Subterránea/química , Materia Orgánica Disuelta , Respiración , Ríos/químicaRESUMEN
The first syntheses of functionalized sila-adamantanes via site-selective reactions are described. Mechanistic inquiry into the isomerization of sila-adamantane revealed new approaches for installing halides at the 2-position of the cluster. Meanwhile, isomerization via Lewis acid catalysts with non-nucleophilic counteranions provided access to sila-adamantane on the gram-scale, enabling us to discover strategies for substituting its 1-, 3-, 5-, and 7-positions with identical or distinct functional groups. Optical absorbance and density functional theory studies show that σ-withdrawing substituents at the 1-position strongly perturb optical absorbance in sila-adamantane, whereas substituents at the exocyclic and 2-position are optically inert. As silicon diamondoids are atomically precise models for silicon nanocrystals, our findings suggest that passivation at tertiary surface sites carries an outsized impact on the optical properties of surface-functionalized Si nanocrystals.
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BACKGROUND: Head injuries are common injury in the fire service; however, very little data exist on the risks this may pose to the development of post-traumatic stress disorder (PTSD) and depression in this high-risk population. AIMS: Our study aimed to compare levels of PTSD and depression symptoms in firefighters with a line-of-duty head injury, non-line-of-duty head injury and no head injury. METHODS: In this cross-sectional study, we assessed current PTSD and depression symptoms as well as retrospective head injuries. RESULTS: Seventy-six per cent of the total sample reported at least one head injury in their lifetime. Depression symptoms were significantly more severe among firefighters with a line-of-duty head injury compared to those with no head injury, but not compared to those who sustained a non-line-of-duty head injury. Depression symptoms did not differ between firefighters with a non-line-of-duty head injury and those with no head injury. PTSD symptoms were significantly more severe among firefighters with a line-of-duty head injury compared to both firefighters with no head injury and those with a non-line-of-duty head injury. CONCLUSIONS: We found that firefighters who reported at least one line-of-duty head injury had significantly higher levels of PTSD and depression symptoms than firefighters who reported no head injuries. Our findings also suggest head injuries sustained outside of fire service could have less of an impact on the firefighter's PTSD symptom severity than head injuries that occur as a direct result of their job.
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Traumatismos Craneocerebrales , Bomberos , Distrés Psicológico , Trastornos por Estrés Postraumático , Traumatismos Craneocerebrales/complicaciones , Traumatismos Craneocerebrales/epidemiología , Estudios Transversales , Depresión/epidemiología , Depresión/etiología , Humanos , Estudios Retrospectivos , Trastornos por Estrés Postraumático/epidemiología , Trastornos por Estrés Postraumático/etiologíaRESUMEN
Since the onset of the SARS-CoV-2 pandemic, the pediatric population has been less affected by the disease both in frequency and severity. However, since April cases of variable presentation and severity characterized by inflammatory phenomena that affect multiple organs have been reported, a condition called Multisystem Inflammatory Syndrome in Children (MIS-C). The literature has reported frequent cardiac involvement, up to 80%. This is characterized by myocardial injury with a significant increase of biomarkers such as serum troponins I and T, BNP, or NT-ProBNP coupled with varying degrees of ventricular dysfunction, pericarditis, valvulitis, and arrhythmias. Coronary compromise has also been described, which can occur in up to 23% of cases, and ranges from dila tations to aneurysms. Inpatient and outpatient cardiology follow-up has been systematized based on the clinical phenotypes such as myocardial injury (myocarditis, valvulitis, pericarditis), shock (usua lly vasoplegic), Kawasaki disease-type manifestations, and those MIS-C that do not comply with the clinic of the previous three. This last group represents the main challenge in the short-, medium- and long-term follow-up, therefore, it is necessary a multidisciplinary team for managing these patients. Considering the high frequency of cardiac compromise in MIS-C, and the importance of reaching a consensus regarding its management and follow-up, we present these recommendations according to the current state of knowledge regarding this recently described pathology.
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COVID-19/terapia , Enfermedades Cardiovasculares/virología , Síndrome de Respuesta Inflamatoria Sistémica/terapia , Biomarcadores/metabolismo , COVID-19/diagnóstico , COVID-19/fisiopatología , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/terapia , Niño , Chile , Humanos , Síndrome Mucocutáneo Linfonodular/terapia , Síndrome Mucocutáneo Linfonodular/virología , Grupo de Atención al Paciente/organización & administración , Choque/terapia , Choque/virología , Síndrome de Respuesta Inflamatoria Sistémica/diagnóstico , Síndrome de Respuesta Inflamatoria Sistémica/fisiopatologíaRESUMEN
Prodiplosis longifila is reported as a pest of a wide range of species cultivated in America, including citrus, solanaceous species and asparagus. This species has different behavioural traits that are primarily centred on the oviposition habit and the feeding of larvae, which can change depending on the host. However, scarce information is available on population studies and the natural history of this insect, and uncertainty exists about the taxonomic identity and the geographic distribution of this species. The main objective was to perform a phylogenetic and genetic study of P. longifila populations and to define whether the North American and South American populations belong to the same species or whether a differentiation process had occurred due to geographic distance. A second objective was to determine whether this species showed genetic differentiation by host specialization in South America. The phylogenetic and population analyses based on DNA barcodes (cytochrome oxidase I gene) and a region of the ribosomal DNA (ITS2) revealed divergent clades attributable to geographic distance and host specificity. The North American and South American P. longifila insects were confirmed to be genetically distinct, and the genetic distances exceeded the values expected for intraspecific variation. In South America, the population analysis of P. longifila from tomato, sweet pepper (Solanaceae), Tahiti lime and key lime (Rutaceae) hosts evidenced high genetic differentiation between populations associated with different hosts and an absence of gene flow between these groups, suggesting the corresponding formation of cryptic species.
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Dípteros/genética , Evolución Molecular , Especiación Genética , Herbivoria , Distribución Animal , Animales , Colombia , ADN Mitocondrial/análisis , ADN Espaciador Ribosómico/análisis , Ecuador , Complejo IV de Transporte de Electrones/análisis , Florida , Filogenia , FilogeografíaRESUMEN
Over the past few years, symptoms akin to late blight disease have been reported on a variety of crop plants in South America. Despite the economic importance of these crops, the causal agents of the diseases belonging to the genus Phytophthora have not been completely characterized. In this study, a new Phytophthora species was described in Colombia from tree tomato (Solanum betaceum), a semi-domesticated fruit grown in northern South America. Comprehensive phylogenetic, morphological, population genetic analyses, and infection assays to characterize this new species, were conducted. All data support the description of the new species, Phytophthora betacei sp. nov. Phylogenetic analyses suggest that this new species belongs to clade 1c of the genus Phytophthora and is a close relative of the potato late blight pathogen, P. infestans. Furthermore, it appeared as the sister group of the P. andina strains collected from wild Solanaceae (clonal lineage EC-2). Analyses of morphological and physiological characters as well as host specificity showed high support for the differentiation of these species. Based on these results, a complete description of the new species is provided and the species boundaries within Phytophthora clade 1c in northern South America are discussed.
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The interaction mechanism of a novel amphiphilic antimicrobial peptide dendrimer, BALY, with model lipid bilayers was explored through a combination of neutron reflection and molecular dynamics simulations. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn-glycero-3-phos-phocholine (DPPC) lipid bilayers were examined at room temperature to extract information on the interaction of BALY with fluid and gel phases, respectively. Furthermore, a 1:4 mixture of POPC and DPPC was used as a model of a phase-separated membrane. Upon interaction with fluid membranes, BALY inserted in the distal leaflet and caused thinning and disordering of the headgroups. Membrane thinning and expansion of the lipid cross-sectional area were observed for gel phase membranes, also with limited insertion to the distal leaflet. However, dendrimer insertion through the entire lipid tail region was observed upon crossing the lipid phase transition temperature of DPPC and in phase separated membranes. The results show clear differences in the interaction mechanism of the dendrimer depending on the lipid membrane fluidity, and suggest a role for lipid phase separation in promoting its antimicrobial activity.
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1,2-Dipalmitoilfosfatidilcolina/química , Péptidos Catiónicos Antimicrobianos/química , Membrana Dobles de Lípidos/química , Fluidez de la Membrana , Simulación de Dinámica Molecular , Fosfatidilcolinas/química , Simulación por Computador , Dendrímeros , Modelos Químicos , Conformación Molecular , Difracción de Neutrones/métodosRESUMEN
AIMS: The health system's response is crucial to addressing the increasing burden of diabetes, particularly that affecting low- and middle-income countries. This study aims to assess the facilitators and barriers that help or hinder access to care for people with diabetes in Peru. METHODS: We used a survey tool to design and collect qualitative and quantitative data from primary and secondary sources of information at different levels of the health system. We performed 111 interviews in Lima, the capital city of Peru, with patients with diabetes, healthcare providers and healthcare officials. We applied the six building blocks framework proposed by the World Health Organization in our analysis. RESULTS: We found low political commitment, as well as several barriers that directly affect access to medicines, regular laboratory check-ups and follow-up appointments for diabetes, especially at the primary healthcare level. Three major system-level barriers were identified: (1) the availability of information at different healthcare system levels that affects several processes in the healthcare provision; (2) insufficient financial resources; and (3) insufficient human resources trained in diabetes management. CONCLUSION: Despite an initial political commitment by the Peruvian government to improve the delivery of diabetes care, there exist several key limitations that affect access to adequate diabetes care, especially at the primary healthcare level. In a context in which various low- and middle-income countries are aiming to achieve universal health coverage, this study provides lessons for the implementation of strategies related to diabetes care delivery.
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Diabetes Mellitus Tipo 2/terapia , Accesibilidad a los Servicios de Salud/normas , Adulto , Anciano , Tecnología Biomédica/estadística & datos numéricos , Gestión Clínica , Diabetes Mellitus Tipo 2/epidemiología , Servicios de Salud/normas , Servicios de Salud/provisión & distribución , Fuerza Laboral en Salud/estadística & datos numéricos , Humanos , Hipoglucemiantes/provisión & distribución , Liderazgo , Persona de Mediana Edad , Perú/epidemiología , Prevalencia , Sector Privado/estadística & datos numéricos , Sector Público/estadística & datos numéricos , Cobertura Universal del Seguro de Salud/estadística & datos numéricos , Adulto JovenRESUMEN
To analyse the cost-effectiveness, in daily clinical practice, of the strategy of treating to the target of clinical remission (CR) in patients with established rheumatoid arthritis (RA), after 2 years of treatment with biological therapy. Adult patients with established RA were treated with biological therapy and followed up for 2 years by a multidisciplinary team responsible for their clinical management. Treatment effectiveness was evaluated by the DAS28 score. The direct costs incurred during this period were quantified from the perspective of the healthcare system. We calculated the cost-effectiveness of obtaining a DAS28 < 2.6, considered as CR. The study included 144 RA patients treated with biological therapies. After 2 years of treatment, 32.6% of patients achieved CR. The mean cost of achieving CR at 2 years was 79,681 ± 38,880 euros. The strategy of treatment to the target of CR is considered the most effective, but in actual clinical practice in patients with established RA, it has a high cost.
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Antirreumáticos/economía , Artritis Reumatoide/tratamiento farmacológico , Productos Biológicos/economía , Análisis Costo-Beneficio , Adulto , Antirreumáticos/uso terapéutico , Artritis Reumatoide/economía , Productos Biológicos/uso terapéutico , Bases de Datos Factuales , Femenino , Costos de la Atención en Salud , Humanos , Masculino , Metotrexato/economía , Metotrexato/uso terapéutico , Persona de Mediana Edad , Inducción de Remisión , Índice de Severidad de la Enfermedad , Sulfasalazina/economía , Sulfasalazina/uso terapéutico , Resultado del TratamientoRESUMEN
Biological drugs have proven efficacy and effectiveness in treatment of rheumatoid arthritis (RA), although none has been shown to be superior. Few studies have evaluated the cost-effectiveness of biological drugs in real-life clinical conditions. The objective of this study was to compare the cost-effectiveness of infliximab, etanercept and adalimumab in achieving clinical remission (DAS28 < 2.6) when used as initial biological therapy. Patients were diagnosed with RA who began treatment with infliximab, etanercept or adalimumab in the Reina Sofia Hospital (Cordoba, Spain) between January 1, 2007, and December 31, 2012. Effectiveness was measured as the percentage of patients who achieved clinical remission after 2 years. The cost analysis considered the use of direct health resources (perspective of the healthcare system). Cost-effectiveness was calculated by dividing the total mean cost of each treatment by the percentage of patients who achieved remission. One hundred and thirty patients were included: 55 with infliximab, 44 with adalimumab and 31 with etanercept. After 2 years, 45.2 % of patients with adalimumab achieved clinical remission, versus 29.1 % with infliximab (p = 0.133) and 22.7 % with etanercept (p = 0.040), with no differences between etanercept and infliximab (p = 0.475). The average total cost at 2 years was 29,858, 25,329 and 23,309 for adalimumab, infliximab and etanercept, respectively, while the mean cost (95 %CI) to achieve remission was 66,057 (48,03884,076), 87,040 (78,49695,584) and 102,683 (94,559110,807), respectively. Adalimumab was more efficient than etanercept (p < 0.001) and infliximab (p = 0.026), with no differences between etanercept and infliximab (p = 0.086). Adalimumab was the most cost-effective treatment in achieving clinical remission in real-life clinical conditions in RA patients during the study period.
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Adalimumab/economía , Adalimumab/uso terapéutico , Antirreumáticos/economía , Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/economía , Costos de los Medicamentos , Etanercept/economía , Etanercept/uso terapéutico , Infliximab/economía , Infliximab/uso terapéutico , Adalimumab/efectos adversos , Adulto , Anciano , Antirreumáticos/efectos adversos , Artritis Reumatoide/diagnóstico , Ahorro de Costo , Análisis Costo-Beneficio , Etanercept/efectos adversos , Femenino , Humanos , Infliximab/efectos adversos , Masculino , Persona de Mediana Edad , Modelos Económicos , Sistema de Registros , Inducción de Remisión , España , Factores de Tiempo , Resultado del TratamientoRESUMEN
OBJECTIVE: The objective of this paper is to evaluate the prevalence and characterize the main epidemiological, clinical and immunological features of annular erythema (AE) in non-Asian patients with primary Sjögren's syndrome (SS). METHODS: We carried out a retrospective study searching for AE in 377 Spanish patients with primary SS fulfilling the 2002 American-European criteria. In addition, we searched PubMed (1994-2012) using the MeSH terms "annular erythema" and "primary Sjögren's syndrome" for additional cases. All cases with AE reported in patients with SS associated with systemic lupus erythematosus were excluded. RESULTS: In our Spanish cohort, we found 35 (9%) patients diagnosed with AE. All were white females, with a mean age of 47 years at diagnosis of AE. AE preceded diagnosis of SS in 27 (77%) patients. Cutaneous AE lesions involved principally the face and upper extremities. All patients reported photosensitivity, with cutaneous flares being reported during the warmest months in 93% of patients. Immunological markers consisted of anti-Ro/La antibodies in 31 (89%) patients. In the literature search, we identified eight additional non-Asian patients with primary SS diagnosed with AE. In comparison with 52 Asian patients, the 43 non-Asian patients with AE related to primary SS were more frequently women (100% vs 78%, p=0.008), and cutaneous lesions were less frequently reported in the face (55% vs 81%, p=0.045) and more frequently in the neck (40% vs 14%, p=0.041). Immunologically, non-Asian patients had a lower frequency of anti-Ro antibodies and a higher frequency of negative Ro/La antibodies, although the differences were not statistically significant. CONCLUSION: AE is not an exclusive cutaneous feature of Asian patients with primary SS. In addition to the characteristic cutaneous expression, AE has a very specific clinical and immunological profile: often presenting before the fulfillment of SS criteria, overwhelmingly associated with anti-Ro antibodies but weakly associated with other immunological markers and the main systemic SS-related features.
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Eritema/complicaciones , Eritema/patología , Síndrome de Sjögren/complicaciones , Enfermedades Cutáneas Genéticas/complicaciones , Enfermedades Cutáneas Genéticas/patología , Adulto , Anticuerpos Antinucleares/sangre , Pueblo Asiatico , Estudios de Cohortes , Eritema/inmunología , Femenino , Humanos , Lupus Eritematoso Cutáneo/complicaciones , Lupus Eritematoso Cutáneo/inmunología , Lupus Eritematoso Cutáneo/patología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Síndrome de Sjögren/inmunología , Enfermedades Cutáneas Genéticas/inmunología , España , Población BlancaRESUMEN
Renal cell carcinoma (RCC) is a heterogenous disease which the incidence is increasing worldwide. The identification and understanding of the role of the Von Hipple Lindau (VHP) in regulating the hypoxia-inducible factor signaling pathway has revolutionized the treatment of this disease. Belzutifan is an oral hypoxia-inducible factor (HIF)-2α inhibitor, which has demonstrated efficacy in treating von Hippel-Lindau (VHL) disease and for the treatment of adults with RCC who experienced disease progression after PD-1/PD-L1- and VEGFR-targeted therapies. One of the most common adverse effect of this drug is anemia; however, it is treatment is not well known. This review summarizes role of the VHL-HIF pathway in ccRCC aroused the interest of targeting HIF activity, the history of belzutifan development and their relationship to anemia as well as propose a management algorithm.
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Anemia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Carcinoma de Células Renales , Neoplasias Renales , Humanos , Carcinoma de Células Renales/tratamiento farmacológico , Carcinoma de Células Renales/metabolismo , Neoplasias Renales/tratamiento farmacológico , Neoplasias Renales/metabolismo , Anemia/tratamiento farmacológico , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/antagonistas & inhibidores , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismoRESUMEN
OBJECTIVE: This study aims to analyze the prescription of antihypertensive drugs in patients with type 2 diabetes (T2D) in Andalusia, comparing it with the SEH-LELHA 2022 guidelines, and to assess the direct cost of these treatments. MATERIALS AND METHODS: A multicentric, cross-sectional, and descriptive study was conducted with 385 T2D patients. Participants were randomly selected from the patient lists of 120 primary care physicians from Andalusia. Inclusion criteria included a diagnosis of T2D and complete clinical records for the year 2022. Demographic data and drug prescription information were collected, with the average cost per patient being calculated. RESULTS: The mean age of the subjects was 70.72 years, with 53.51% being male. A total of 70.9% of the patients were taking antihypertensive drugs, the most common being ACE inhibitors/ARBs (70.9%), diuretics (70.1%), beta-blockers (40.0%), and calcium channel blockers (20.0%). Each patient took an average of 2.46±1.06 antihypertendsive, and fixed association of 2 or more antihypertensive drugs were used by 40.9% of the studied patients. The annual cost per patient was 141.45/year. CONCLUSIONS: The study reveals strong adherence to the SEH-LELHA 2022 guidelines among physicians in Andalusia regarding the of antihypertensives for T2D patients, with a significant preference for Renin-Angiotensin System blockers, diuretics, and beta-blockers. However, a notable deviation in prescription practices was observed with the frequent choice of doxazosin over spironolactone, despite the latter being the recommended option for resistant hypertension. Although the overall expenditure on antihypertensives is moderate, their cost-effectiveness is enhanced by the efficacy of these treatments in preventing cardiovascular complications.
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Measurement of biogeochemical processes in permeable sediments (including the hyporheic zone) is difficult because of complex multidimensional advective transport. This is especially the case for nitrogen cycling, which involves several coupled redox-sensitive reactions. To provide detailed insight into the coupling between ammonification, nitrification and denitrification in stationary sand ripples, we combined the diffusion equilibrium thin layer (DET) gel technique with a computational reactive transport biogeochemical model. The former approach provided high-resolution two-dimensional distributions of NO3(-) and (15)N-N2 gas. The measured two-dimensional profiles correlate with computational model simulations, showing a deep pool of N2 gas forming, and being advected to the surface below ripple peaks. Further isotope pairing calculations on these data indicate that coupled nitrification-denitrification is severely limited in permeable sediments because the flow and transport field limits interaction between oxic and anoxic pore water. The approach allowed for new detailed insight into subsurface denitrification zones in complex permeable sediments.
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Desnitrificación , Sedimentos Geológicos , Modelos Teóricos , Nitrificación , Nitrógeno/análisis , Oxidación-ReducciónRESUMEN
Simulations of coupled flow around and inside biofilms in pores were conducted to study the effect of porous biofilm on micro- and macro-scale flow and transport. The simulations solved the Navier-Stokes equations coupled with the Brinkman equation representing flow in the pore space and biofilm, respectively, and the advection-diffusion equation. Biofilm structure and distribution were obtained from confocal microscope images. The bulk permeability (k) of bioclogged porous media depends on biofilm permeability (kbr) following a sigmoidal curve on a log-log scale. The upper and lower limits of the curve are the k of biofilm-free media and of bioclogged media with impermeable biofilms, respectively. On the basis of this, a model is developed that predicts k based solely on kbr and biofilm volume ratio. The simulations show that kbr has a significant impact on the shear stress distribution, and thus potentially affects biofilm erosion and detachment. The sensitivity of flow fields to kbr directly translated to effects on the transport fields by affecting the relative distribution of where advection and diffusion dominated. Both kbr and biofilm volume ratio affect the shape of breakthrough curves.
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Biopelículas , Modelos Teóricos , Pseudomonas fluorescens/fisiología , Biopelículas/crecimiento & desarrollo , Permeabilidad , PorosidadRESUMEN
KEY MESSAGE : Agrobacterium tumefaciens strains differ not only in their ability to transform tomato Micro-Tom, but also in the number of transgene copies that the strains integrate in the genome. The transformation efficiency of tomato (Solanum lycopersicum L.) cv. Micro-Tom with Agrobacterium tumefaciens strains AGL1, EHA105, GV3101, and MP90, harboring the plasmid pBI121 was compared. The presence of the nptII and/or uidA transgenes in regenerated T(0) plants was determined by PCR, Southern blotting, and/or GUS histochemical analyses. In addition, a rapid and reliable duplex, qPCR TaqMan assay was standardized to estimate transgene copy number. The highest transformation rate (65 %) was obtained with the Agrobacterium strain GV3101, followed by EHA105 (40 %), AGL1 (35 %), and MP90 (15 %). The mortality rate of cotyledons due to Agrobacterium overgrowth was the lowest with the strain GV3101. The Agrobacterium strain EHA105 was more efficient than GV3101 in the transfer of single T-DNA insertions of nptII and uidA transgenes into the tomato genome. Even though Agrobacterium strain MP90 had the lowest transformation rate of 15 %, the qPCR analysis showed that the strain MP90 was the most efficient in the transfer of single transgene insertions, and none of the transgenic plants produced with this strain had more than two insertion events in their genome. The combination of higher transformation efficiency and fewer transgene insertions in plants transformed using EHA105 makes this Agrobacterium strain optimal for functional genomics and biotechnological applications in tomato.
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Agrobacterium tumefaciens/genética , Solanum lycopersicum/genética , Transformación Genética/genética , Southern Blotting , Cotiledón/citología , Cotiledón/genética , Cotiledón/crecimiento & desarrollo , Cotiledón/fisiología , ADN Bacteriano/genética , Dosificación de Gen , Solanum lycopersicum/citología , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/fisiología , Raíces de Plantas/citología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/fisiología , Brotes de la Planta/citología , Brotes de la Planta/genética , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/fisiología , Plantas Modificadas Genéticamente , Plásmidos , Distribución Aleatoria , Reacción en Cadena en Tiempo Real de la Polimerasa , Regeneración , Factores de Tiempo , TransgenesRESUMEN
The laboratory mouse is the premier model system for studies of mammalian development due to the powerful classical genetic analysis possible (see also the Jackson Laboratory web site, http://www.jax.org/) and the ever-expanding collection of molecular tools. To enhance the utility of the mouse system, we initiated a program to generate a large database of expressed sequence tags (ESTs) that can provide rapid access to genes. Of particular significance was the possibility that cDNA libraries could be prepared from very early stages of development, a situation unrealized in human EST projects. We report here the development of a comprehensive database of ESTs for the mouse. The project, initiated in March 1996, has focused on 5' end sequences from directionally cloned, oligo-dT primed cDNA libraries. As of 23 October 1998, 352,040 sequences had been generated, annotated and deposited in dbEST, where they comprised 93% of the total ESTs available for mouse. EST data are versatile and have been applied to gene identification, comparative sequence analysis, comparative gene mapping and candidate disease gene identification, genome sequence annotation, microarray development and the development of gene-based map resources.