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1.
bioRxiv ; 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38853978

RESUMEN

Current therapeutic strategies for Alzheimer's disease (AD) target amyloid-beta (Aß) fibrils and high molecular weight protofibrils associated with plaques, but other bioactive species may directly contribute to neural systems failure in AD. Employing hippocampal electrophysiological recordings and dynamic calcium imaging across the sleep-wake cycle in young mice expressing human Aß and Aß oligomers, we reveal marked impairments of hippocampal function long before amyloid plaques predominate. In slow wave sleep (SWS), Aß increased the proportion of hypoactive cells and reduced place-cell reactivation. During awake behavior, Aß impaired theta-gamma phase-amplitude coupling (PAC) and drove excessive synchronization of place cell calcium fluctuations with hippocampal theta. Remarkably, the on-line impairment of hippocampal theta-gamma PAC correlated with the SWS impairment of place-cell reactivation. Together, these results identify toxic effects of Aß on memory encoding and consolidation processes before robust plaque deposition and support targeting soluble Aß-related species to treat and prevent AD.

2.
Front Microbiol ; 15: 1370686, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38572245

RESUMEN

Lignocellulosic pretreatment is an important stage in biomass utilization, which usually requires high input. In this study, a low-cost method using combined ensiling and NaOH was developed for lignocellulosic pretreatment. Sweet sorghum bagasse (SSB) was ensiled for 21 days and then treated with diluted NaOH (0%, 1%, and 2%) for fermentation. The results showed that the application of Lactobacillus plantarum (L) reduced fermentation losses of the silages, mainly low water-soluble carbohydrate (WSC) and ammonia nitrogen loss. Meanwhile, the application of Lactobacillus plantarum and ensiling enzyme (LE) promoted lignocellulosic degradation, as evidenced by low neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (ADL), and hemicellulosic (HC) contents. The dominant bacterial genera were Lactobacillus, uncultured_bacterium_f_Enterobacteriaceae, and Pantoea after silage, which corresponded to the higher lactic acid and acetic contents and lower pH. The reducing sugar yields of SSB increased after combined pretreatment of silage and NaOH and were further enhanced by the 2% NaOH application, as evidenced by the high reducing sugar yield and microstructure damage, especially in the L-2% NaOH group and the LE-2% NaOH group, in which the reducing sugar yields were 87.99 and 94.45%, respectively, compared with those of the no additive control (CK)-0 NaOH group. Therefore, this study provides an effective method for SSB pretreatment to enhance biomass conservation.

3.
Sensors (Basel) ; 24(7)2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38610324

RESUMEN

The traditional rearview mirror method cannot fully guarantee safety when driving trucks. RGB and infrared images collected by cameras are used for registration and recognition, so as to achieve the perception of surroundings and ensure safe driving. The traditional scale-invariant feature transform (SIFT) algorithm has a mismatching rate, and the YOLO algorithm has an optimization space in feature extraction. To address these issues, this paper proposes a truck surround sensing technique based on multi-features and an improved YOLOv5 algorithm. Firstly, the edge corner points and infrared features of the preset target region are extracted, and then a feature point set containing the improved SIFT algorithm is generated for registration. Finally, the YOLOv5 algorithm is improved by fusing infrared features and introducing a composite prediction mechanism at the prediction end. The simulation results show that, on average, the image stitching accuracy is improved by 17%, the time is reduced by 89%, and the target recognition accuracy is improved by 2.86%. The experimental results show that this method can effectively perceive the surroundings of trucks, accurately identify targets, and reduce the missed alarm rate and false alarm rate.

4.
Nat Microbiol ; 9(2): 524-536, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38297167

RESUMEN

Ammonia-oxidizing microorganisms (AOM) contribute to one of the largest nitrogen fluxes in the global nitrogen budget. Four distinct lineages of AOM: ammonia-oxidizing archaea (AOA), beta- and gamma-proteobacterial ammonia-oxidizing bacteria (ß-AOB and γ-AOB) and complete ammonia oxidizers (comammox), are thought to compete for ammonia as their primary nitrogen substrate. In addition, many AOM species can utilize urea as an alternative energy and nitrogen source through hydrolysis to ammonia. How the coordination of ammonia and urea metabolism in AOM influences their ecology remains poorly understood. Here we use stable isotope tracing, kinetics and transcriptomics experiments to show that representatives of the AOM lineages employ distinct regulatory strategies for ammonia or urea utilization, thereby minimizing direct substrate competition. The tested AOA and comammox species preferentially used ammonia over urea, while ß-AOB favoured urea utilization, repressed ammonia transport in the presence of urea and showed higher affinity for urea than for ammonia. Characterized γ-AOB co-utilized both substrates. These results reveal contrasting niche adaptation and coexistence patterns among the major AOM lineages.


Asunto(s)
Archaea , Bacterias , Archaea/metabolismo , Bacterias/metabolismo , Amoníaco/metabolismo , Nitrógeno/metabolismo , Oxidación-Reducción , Nitrificación , Filogenia , Microbiología del Suelo , Urea/metabolismo
5.
Sensors (Basel) ; 23(23)2023 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-38067668

RESUMEN

Forward collision warning (FCW) is a critical technology to improve road safety and reduce traffic accidents. However, the existing multi-sensor fusion methods for FCW suffer from a high false alarm rate and missed alarm rate in complex weather and road environments. For these issues, this paper proposes a decision-level fusion collision warning strategy. The vision algorithm and radar tracking algorithm are improved in order to reduce the false alarm rate and omission rate of forward collision warning. Firstly, this paper proposes an information entropy-based memory index for an adaptive Kalman filter for radar target tracking that can adaptively adjust the noise model in a variety of complex environments. Then, for visual detection, the YOLOv5s model is enhanced in conjunction with the SKBAM (Selective Kernel and Bottleneck Attention Mechanism) designed in this paper to improve the accuracy of vehicle target detection. Finally, a decision-level fusion warning fusion strategy for millimeter-wave radar and vision fusion is proposed. The strategy effectively fuses the detection results of radar and vision and employs a minimum safe distance model to determine the potential danger ahead. Experiments are conducted under various weather and road conditions, and the experimental results show that the proposed algorithm reduces the false alarm rate by 11.619% and the missed alarm rate by 15.672% compared with the traditional algorithm.

6.
Environ Sci Technol ; 57(42): 16016-16032, 2023 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-37819800

RESUMEN

We conducted a field study to investigate the role of stringent response in cyanobacteria and coexisting bacterioplankton during nutrient-deprived periods at various stages of bloom in a freshwater lake (Utah Lake) for the first time. Using metagenomics and metatranscriptomics analyses, we examined the cyanobacterial ecology and expression of important functional genes related to stringent response, N and P metabolism, and regulation. Our findings mark a significant advancement in understanding the mechanisms by which toxic cyanobacteria survive and proliferate during nitrogen (N) and phosphorus (P) limitations. We successfully identified and analyzed the metagenome-assembled genomes (MAGs) of the dominant bloom-forming cyanobacteria, namely, Dolichospermum circinale, Aphanizomenon flos-aquae UKL13-PB, Planktothrix agardhii, and Microcystis aeruginosa. By mapping RNA-seq data to the coding sequences of the MAGs, we observed that these four prevalent cyanobacteria species activated multiple functions to adapt to the depletion of inorganic nutrients. During and after the blooms, the four dominant cyanobacteria species expressed high levels of transcripts related to toxin production, such as microcystins (mcy), anatoxins (ana), and cylindrospermopsins (cyr). Additionally, genes associated with polyphosphate (poly-P) storage and the stringent response alarmone (p)ppGpp synthesis/hydrolysis, including ppk, relA, and spoT, were highly activated in both cyanobacteria and bacterioplankton. Under N deficiency, the main N pathways shifted from denitrification and dissimilatory nitrate reduction in bacterioplankton toward N2-fixing and assimilatory nitrate reduction in certain cyanobacteria with a corresponding shift in the community composition. P deprivation triggered a stringent response mediated by spoT-dependent (p)ppGpp accumulation and activation of the Pho regulon in both cyanobacteria and bacterioplankton, facilitating inorganic and organic P uptake. The dominant cyanobacterial MAGs exhibited the presence of multiple alkaline phosphatase (APase) transcripts (e.g., phoA in Dolichospermum, phoX in Planktothrix, and Microcystis), suggesting their ability to synthesize and release APase enzymes to convert ambient organic P into bioavailable forms. Conversely, transcripts associated with bacterioplankton-dominated pathways like denitrification were low and did not align with the occurrence of intense cyanoHABs. The strong correlations observed among N, P, stringent response metabolisms and the succession of blooms caused by dominant cyanobacterial species provide evidence that the stringent response, induced by nutrient limitation, may activate unique N and P functions in toxin-producing cyanobacteria, thereby sustaining cyanoHABs.


Asunto(s)
Cianobacterias , Microcystis , Guanosina Pentafosfato , Nitratos , Cianobacterias/genética , Lagos , Organismos Acuáticos
7.
Sci Rep ; 13(1): 13075, 2023 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-37567942

RESUMEN

Patients with Alzheimer's disease (AD) exhibit non-rapid eye movement (NREM) sleep disturbances in addition to memory deficits. Disruption of NREM slow waves occurs early in the disease progression and is recapitulated in transgenic mouse models of beta-amyloidosis. However, the mechanisms underlying slow-wave disruptions remain unknown. Because astrocytes contribute to slow-wave activity, we used multiphoton microscopy and optogenetics to investigate whether they contribute to slow-wave disruptions in APP/PS1 mice. The power but not the frequency of astrocytic calcium transients was reduced in APP/PS1 mice compared to nontransgenic controls. Optogenetic activation of astrocytes at the endogenous frequency of slow waves restored slow-wave power, reduced amyloid deposition, prevented neuronal calcium elevations, and improved memory performance. Our findings revealed malfunction of the astrocytic network driving slow-wave disruptions. Thus, targeting astrocytes to restore circuit activity underlying sleep and memory disruptions in AD could ameliorate disease progression.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/patología , Optogenética/efectos adversos , Calcio , Astrocitos/metabolismo , Ratones Transgénicos , Calcio de la Dieta , Modelos Animales de Enfermedad , Encéfalo/metabolismo , Progresión de la Enfermedad , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética
8.
Res Sq ; 2023 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-37163040

RESUMEN

Patients with Alzheimer's disease (AD) exhibit non-rapid eye movement (NREM) sleep disturbances in addition to memory deficits. Disruption of NREM slow waves occurs early in the disease progression and is recapitulated in transgenic mouse models of beta-amyloidosis. However, the mechanisms underlying slow-wave disruptions remain unknown. Because astrocytes contribute to slow-wave activity, we used multiphoton microscopy and optogenetics to investigate whether they contribute to slow-wave disruptions in APP mice. The power but not the frequency of astrocytic calcium transients was reduced in APP mice compared to nontransgenic controls. Optogenetic activation of astrocytes at the endogenous frequency of slow waves restored slow-wave power, reduced amyloid deposition, prevented neuronal calcium elevations, and improved memory performance. Our findings revealed malfunction of the astrocytic network driving slow-wave disruptions. Thus, targeting astrocytes to restore circuit activity underlying sleep and memory disruptions in AD could ameliorate disease progression.

9.
Thorac Cardiovasc Surg ; 71(7): 535-541, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-35144289

RESUMEN

BACKGROUND: The sutureless valve has gained popularity for degenerative aortic valve stenosis but not congenital bicuspid aortic valve (BAV) due to anatomical challenges. We reviewed our modified implant techniques for patients with BAV. METHODS: From June 2015 to June 2019, 66 patients with aortic valve stenosis were treated with the Perceval sutureless valve, 20 of whom had BAV. The demographics, type of BAV (the Sievers classification), and associated pathologies, surgical outcomes, and midterm hemodynamics were recorded. RESULTS: The median age was 64 (range: 49-81) years and the Society of Thoracic Surgeons score was 2.186 (range: 0.407-6.384). Annular plication was performed in 9 (75%) of 12 type 0 and 3 (37.5%) of 8 type I, with implanted valve sizes of M, L, and XL in 6, 10, 4 cases, respectively. Three patients, all type 0 in the initial learning periods, required intraoperative redeployment due to malposition of the valve. The final implant was successful in all without conversion to traditional prosthesis. The median extubation time was 4 hours and the durations of intensive care unit and hospital stay were 1 and 6 days. At a median follow-up of 46 (23-72) months, there was one late mortality due to hemorrhagic stroke sequel. The last echo revealed none had more than mild paravalvular leakage and the mean transvalvular pressure gradient remained stable at 9.70 (range: 6.94-15.0) mm Hg. CONCLUSION: The sutureless valve can achieve satisfactory outcomes in BAV without paravalvular leakage and excellent hemodynamics. It may serve as the benchmark for transcatheter aortic valve implantation in this unique population.


Asunto(s)
Estenosis de la Válvula Aórtica , Enfermedad de la Válvula Aórtica Bicúspide , Enfermedades de las Válvulas Cardíacas , Implantación de Prótesis de Válvulas Cardíacas , Prótesis Valvulares Cardíacas , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Persona de Mediana Edad , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Válvula Aórtica/anomalías , Enfermedades de las Válvulas Cardíacas/diagnóstico por imagen , Enfermedades de las Válvulas Cardíacas/cirugía , Enfermedades de las Válvulas Cardíacas/complicaciones , Enfermedad de la Válvula Aórtica Bicúspide/cirugía , Resultado del Tratamiento , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/complicaciones , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/métodos
10.
Sci Rep ; 12(1): 21022, 2022 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-36471155

RESUMEN

The Alzheimer's disease-associated peptide amyloid-beta (Aß) has been associated with neuronal hyperactivity under anesthesia, but clinical trials of anticonvulsants or neural system suppressors have, so far, failed to improve symptoms in AD. Using simultaneous hippocampal calcium imaging and electrophysiology in freely moving mice expressing human Aß, here we show that Aß aggregates perturbed neural systems in a state-dependent fashion, driving neuronal hyperactivity in exploratory behavior and slow wave sleep (SWS), yet suppressing activity in quiet wakefulness (QW) and REM sleep. In exploratory behavior and REM sleep, Aß impaired hippocampal theta-gamma phase-amplitude coupling and altered neuronal synchronization with theta. In SWS, Aß reduced cortical slow oscillation (SO) power, the coordination of hippocampal sharp wave-ripples with both the SO and thalamocortical spindles, and the coordination of calcium transients with the sharp wave-ripple. Physostigmine improved Aß-associated hyperactivity in exploratory behavior and hypoactivity in QW and expanded the range of gamma that coupled with theta phase, but exacerbated hypoactivity in exploratory behavior. Together, these findings show that the effects of Aß alone on hippocampal circuit function are profoundly state dependent and suggest a reformulation of therapeutic strategies aimed at Aß induced hyperexcitability.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Hipocampo , Animales , Humanos , Ratones , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Calcio/metabolismo , Modelos Animales de Enfermedad , Hipocampo/fisiopatología , Ratones Transgénicos
11.
Micromachines (Basel) ; 13(10)2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36295954

RESUMEN

This paper researches the fabrication of a WR2.8 terahertz rectangular waveguide operating at the frequency ranging from 260 GHz to 400 GHz via UV-LIGA technology (UV-lithography, electroplating, and molding). In the process, megasonic agitation is applied to improve the mechanical properties and internal surface roughness of the WR2.8 rectangular waveguide. The effects of process parameters on the properties of structures are discussed, and optimized parameters are obtained to achieve accurate geometry dimensions. In addition, the highly crosslinked SU-8 is reliably removed from structures without damage through a synthesis method. The accuracy of the height and width of the WR2.8 rectangular waveguide is 5 µm and 2 µm, respectively, and the measured internal surface roughness is 79.6 nm. Moreover, experimental measurements and numerical simulations of the waveguide are conducted, and the difference between the two is also highlighted.

12.
Chemosphere ; 302: 134784, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35504465

RESUMEN

Nitrogen (N) cycling is an essential process in lake systems and N-fixation is an important component of it. Recent studies have also found that nitrate reduction through heterotrophic denitrification in lake systems did not prevent harmful cyanobacterial blooms, but instead, may have favored the dominance of N2-fixing cyanobacteria. The overall objective of this study was to estimate nitrogen fixation rates and the expressions of associated nitrogenase (nif gene) functional gene at several sites at different occasions in freshwater Utah Lake. For comparison purposes, one time sampling was also conducted in the brackish Farmington Bay of Great Salt Lake (GSL). The microbial ecology of the top 20-cm of surface water was investigated to assess the dominant cyanobacterial communities and N-related metabolisms. Our study revealed that Dolichospermum and Nodularia were potential N2-fixers for Utah Lake and brackish Farmington Bay, respectively. The in situ N2-fixation rates were 0-0.73 nmol N hr-1L-1 for Utah Lake and 0-0.85 nmol N hr-1L-1 for Farmington Bay, and these rates positively correlated with the abundance and expressions of the nif gene. In addition, nitrate reduction was measured in sediment (0.002-0.094 mg N VSS-1 hr-1). Significantly positive correlations were found among amoA, nirS and nirK abundance (R = 0.56-0.87, p < 0.05, Spearman) in both lakes. An exception was the lower nirK gene abundance detected at one site in Farmington Bay where high ammonium retentions were also detected. Based on a mass balance approach, we concluded that the amount of inorganic N loss through denitrification still exceeded the N input by N2-fixation, much like in most lakes, rivers, and marine ecosystems. This indicates that N cycling processes such as denitrification mediated by heterotrophic bacteria contributes to N-export from the lakes resulting in N limitations.


Asunto(s)
Cianobacterias , Lagos , Cianobacterias/genética , Cianobacterias/metabolismo , Ecosistema , Eutrofización , Lagos/microbiología , Nitratos , Nitrógeno/análisis , Fijación del Nitrógeno , Utah
13.
Sci Total Environ ; 796: 148905, 2021 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-34271386

RESUMEN

Several treatment plants were sampled for influent, primary clarifier sludge, return activated sludge (RAS), and anaerobically digested sludge throughout nine weeks during the summer of the COVID-19 pandemic. Primary clarifier sludge had a significantly higher number of SARS-CoV-2 gene copy number per liter (GC/L) than other sludge samples, within a range from 1.0 × 105 to 1.0 × 106 GC/L. Gene copy numbers in raw influent significantly correlated with gene copy numbers in RAS in Silver Creek (p-value = 0.007, R2 = 0.681) and East Canyon (p-value = 0.009, R2 = 0.775) WRFs; both of which lack primary clarifiers or industrial pretreatment processes. This data indicates that SARS-CoV-2 gene copies tend to partition into primary clarifier sludges, at which point a significant portion of them are removed through sedimentation. Furthermore, it was found that East Canyon WRF gene copy numbers in influent were a significant predictor of daily cases (p-value = 0.0322, R2 = 0.561), and gene copy numbers in RAS were a significant predictor of weekly cases (p-value = 0.0597, R2 = 0.449). However, gene copy numbers found in primary sludge samples from other plants significantly predicted the number of COVID-19 cases for the following week (t = 2.279) and the week after that (t = 2.122) respectively. These data indicate that SARS-CoV-2 extracted from WRF biosolids may better suit epidemiological monitoring that exhibits a time lag. It also supports the observation that primary sludge removes a significant portion of SARS-CoV-2 marker genes. In its absence, RAS can also be used to predict the number of COVID-19 cases due to direct flow through from influent. This research represents the first of its kind to thoroughly examine SARS-CoV-2 gene copy numbers in biosolids throughout the wastewater treatment process and the relationship between primary, return activated, and anaerobically digested sludge and reported positive COVID-19 cases.


Asunto(s)
COVID-19 , Purificación del Agua , Anaerobiosis , Humanos , Pandemias , Prevalencia , SARS-CoV-2 , Aguas Residuales , Agua
14.
Ann Thorac Surg ; 111(5): e369-e371, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33524356

RESUMEN

The Perceval sutureless valve has gained in popularity for treating degenerative aortic valve stenosis but not for congenital type 0 bicuspid aortic valve owing to anatomic challenges. We modified implant techniques following the four principles of ECHO-an acronym for elasticity, circularity, height, and orientation-to prevent paravalvular leakage and malposition.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas/métodos , Prótesis Valvulares Cardíacas , Estenosis de la Válvula Mitral/cirugía , Válvula Mitral/anomalías , Procedimientos Quirúrgicos sin Sutura/métodos , Humanos , Válvula Mitral/diagnóstico por imagen , Estenosis de la Válvula Mitral/congénito , Estenosis de la Válvula Mitral/diagnóstico , Tomografía Computarizada por Rayos X
15.
Water Res ; 185: 116292, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-33086464

RESUMEN

The current study reports the community succession of different toxin and non-toxin producing cyanobacteria at different stages of cyanobacterial harmful algal blooms (CyanoHABs) and their connectivity with nitrogen and phosphorus cycles in a freshwater lake using an ecogenomics framework. Comprehensive high throughput DNA sequencing, water quality parameter measurements, and functional gene expressions over temporal and spatial scales were employed. Among the cyanobacterial community, the lake was initially dominated by Cyanobium during the months of May, June, and early July, and later primarily by Aphanizomenon and Dolichospermum depicting functional redundancy. Finally, Planktothrix appeared in late August and then the dominance switched to Planktothrix in September. Microcystis aeruginosa and Microcystis panniformis; two species responsible for cyanotoxin production, were also present in August and September, but in significantly smaller relative abundance. MC-LR (0.06-1.32 µg/L) and MC-RR (0.01-0.26 µg/L) were two major types of cyanotoxins detected. The presence of MC-LR and MC-RR were significantly correlated with the Microcystis-related genes (16SMic/mcyA/mcyG) and their expressions (r = 0.33 to 0.8, p < 0.05). The metabolic analyses further linked the presence of different cyanobacterial groups with distinct functions. The nitrogen metabolisms detected a relatively higher abundance of nitrite/nitrate reductase in early summer, indicating significant denitrification activity and the activation of N-fixation in the blooms dominated by Aphanizomenon/Dolichospermum (community richness) during nutrient-limited conditions. The phosphorus and carbohydrate metabolisms detected a trend to initiate a nutrient starvation alert and store nutrients from early summer, while utilizing the stored polyphosphate and carbohydrate (PPX and F6PPK) during the extreme ortho-P scarcity period, mostly in August or September. Specifically, the abundance of Aphanizomenon and Dolichospermum was positively correlated with the nitrogen-fixing nif gene and (p < 0.001) and the PPX enzyme for the stored polyphosphate utilization (r = 0.77, p < 0.001). Interestingly, the lake experienced a longer N-fixing period (2-3 months) before non-fixing cyanobacteria (Planktothrix) dominated the entire lake in late summer. The Provo Bay site, which is known to be nutrient-rich historically, had early episodes of filamentous cyanobacteria blooms compared to the rest of the lake.


Asunto(s)
Cianobacterias , Microbiota , Cianobacterias/genética , Floraciones de Algas Nocivas , Lagos , Microcystis
16.
Environ Pollut ; 266(Pt 1): 115283, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32805604

RESUMEN

Harmful cyanobacterial blooms produce lethal toxins in many aquatic ecosystems experiencing eutrophication. This manuscript presents results on the effects of cyanotoxins on the aerobic microbial communities residing at the interface of sediments and water columns with the ammonia-oxidizing bacteria (AOB) as the model microbial community. Microcystin-LR (MC-LR), a heavily researched cyanotoxin variant, was used as the model cyanotoxin. To measure cyanotoxin influence on the activity of nitrifying microbial communities, an enriched culture of AOBs collected from an ongoing partial nitrification-nitritation reactor was examined for its exposure to 1, 5 and 10 µg/L of MC-LR. The nitritation kinetics experiment demonstrated MC-LR's ability at 1, 5, and 10 µg/L concentrations to prevent ammonium oxidation with statistically significant differences in nitritation rates between the blanks and spiked samples (One-way ANOVA, p < 0.05). Significantly decreased dissolved oxygen (DO) consumption during oxygen update batch tests demonstrated toxin's influence on AOB's oxidizing capabilities when exposed to even lower concentrations of 0.75, 0.5, and 0.25 µg/L of MC-LR in a separate set of experiments. Based on competitive kinetics, the MC-LR inhibition coefficient-the concentration needed to produce half-maximum inhibition of the mixed community AOBs was determined to be 0.083 µg/L. The stress tests proved the recovery of nitritation to some extent at lower MC-LR concentrations (1 and 5 µg/L), but significant irreversible inhibition was recorded when the AOB population was exposed to 10 µg/L MC-LR. The comparisons of amoA gene expressions corresponded well with nitrifying kinetics. All concentrations of MC-LR spiking were determined to produce a discernible impact on the AOB nitritation rate by either destroying the bacterial cell or immediately inhibiting the amoA gene expression.


Asunto(s)
Cianobacterias , Nitrógeno , Eutrofización , Microcistinas , Nitrificación , Agua
17.
Front Neurosci ; 14: 367, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32410946

RESUMEN

The Substantia Nigra pars reticulata (SNr) is a promising target for deep brain stimulation (DBS) to treat the gait and postural disturbances in Parkinson's disease (PD). Positioning the DBS electrode within the SNr is critical for the development of preclinical models of SNr DBS to investigate underlying mechanisms. However, a complete characterization of intraoperative microelectrode recordings in the SNr to guide DBS electrode placement is lacking. In this study, we recorded extracellular single-unit activity in anesthetized rats at multiple locations in the medial SNr (mSNr), lateral SNr (lSNr), and the Ventral Tegmental Area (VTA). Immunohistochemistry and fluorescently dyed electrodes were used to map neural recordings to neuroanatomy. Neural recordings were analyzed in the time domain (i.e., firing rate, interspike interval (ISI) correlation, ISI variance, regularity, spike amplitude, signal-to-noise ratio, half-width, asymmetry, and latency) and the frequency domain (i.e., spectral power in frequency bands of interest). Spike amplitude decreased and ISI correlation increased in the mSNr versus the lSNr. Spike amplitude, signal-to-noise ratio, and ISI correlation increased in the VTA versus the mSNr. ISI correlation increased in the VTA versus the lSNr. Spectral power in the VTA increased versus: (1) the mSNr in the 20-30 Hz band and (2) the lSNr in the 20-40 Hz band. No significant differences were observed between structures for any other feature analyzed. Our results shed light on the heterogeneity of the SNr and suggest electrophysiological features to promote precise targeting of SNr subregions during stereotaxic surgery.

18.
Sci Rep ; 10(1): 2690, 2020 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-32060394

RESUMEN

This retrospective study aimed to clarify the short- and mid-term outcomes of elderly patients who underwent surgery to treat left-sided native valve infective endocarditis (LSNIE). Between July 2005 and September 2015, 179 patients underwent surgical treatment for active LSNIE at a single institution. Patients were classified into two groups: ≥65 years (elderly group) and <65 years (non-elderly group). Clinical features, surgical information, postoperative complications, and three-year survival rates were compared. The average ages were 74.2 ± 6.4 and 45.2 ± 12.6 years in the elderly and non-elderly groups, respectively. The elderly group had a higher predicted mortality rate and a lower incidence of preoperative septic emboli-related complications. Echocardiographic assessments of infected valves were generally homogenous between the groups. The elderly patients had a higher in-hospital mortality rate than the non-elderly patients (26.3% vs. 5.7%, P = 0.001). For patients who survived to discharge, the three-year cumulative survival rates were 75.0% ± 8.2% and 81.2% ± 3.4% in the elderly and non-elderly groups, respectively (P = 0.484). In conclusion, elderly patients are at a higher risk of in-hospital mortality after surgery for LSNIE. However, once elderly patients are stabilized by surgical treatment and survive to discharge, the mid-term outcomes are promising.


Asunto(s)
Endocarditis Bacteriana/cirugía , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Infecciones Relacionadas con Prótesis/cirugía , Infecciones Estafilocócicas/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Ecocardiografía , Endocarditis Bacteriana/complicaciones , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/patología , Femenino , Prótesis Valvulares Cardíacas/microbiología , Implantación de Prótesis de Válvulas Cardíacas/métodos , Mortalidad Hospitalaria , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Infecciones Relacionadas con Prótesis/complicaciones , Infecciones Relacionadas con Prótesis/microbiología , Infecciones Relacionadas con Prótesis/patología , Estudios Retrospectivos , Factores de Riesgo , Infecciones Estafilocócicas/complicaciones , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/patología , Resultado del Tratamiento
19.
Sci Total Environ ; 661: 465-480, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-30677691

RESUMEN

The current study presents findings related to algal blooms in a fresh water lake, which has been experiencing severe cyanobacterial blooms (CyanoHABs). Primarily, picocyanobacteria belonging to the genus Synechococcus and filamentous cyanobacterial group belonging to Aphanizomenon and Dolichospermum dominated top water column during non-bloom and bloom periods respectively. The dominance of Synechococcus in early summer informs that blooming in Utah Lake starts in early summer and then later is taken over by other bloom-forming cyanobacteria, such as species belonging to the genus Aphanizomenon. A strong negative correlation (r = -0.9, p < 0.001) was found between the occurrence of Aphanizomenon and Synechococcus which correlates very well with the fact that the blooms of these two different cyanobacteria never coexisted. The predominance of cyanobacteria in 2017 was attributed more to temperature (r = 0.18, p < 0.001). The Actinobacteria was negatively correlated with primary production and high chlorophyll a concentration. Flavobacterium and Limnohabitans were the main phytoplankton colonizers and predators detected that could secrete extracellular enzymes to degrade algal exudates (such as proteins and polysaccharides). Additionally, cyanotoxins producers Microcystis aeruginosa and Planktothrix accounted for up to 12.43% and 7.04% of total cyanobacteria abundance during blooms. The relative abundance of chloroplast reads was overall lower than the cyanobacteria reads, except for the May 5th sampling in 2017. There was inter-annual variability in the bloom-associated heterotrophic bacterial populations, but these populations were consistent with bloom-associated bacterial populations found in other lakes. Community diversity analysis for both Shannon and Simpson indices indicated lower community diversity during the bloom period. The beta diversity conducted by PCoA and UPGMA trees suggested the significant temporal rather than spatial impacts on shaping the phytoplankton community structures during the summer season.


Asunto(s)
Cianobacterias/fisiología , Floraciones de Algas Nocivas , Lagos/microbiología , Microbiota/fisiología , Cianobacterias/clasificación , ADN Bacteriano/análisis , Secuenciación de Nucleótidos de Alto Rendimiento , Utah , Calidad del Agua
20.
Medicine (Baltimore) ; 96(39): e8146, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28953653

RESUMEN

Cardiovascular disease is the major morbidity and leading cause of mortality for dialysis-dependent patients. This study aimed to stratify the risk factors and effects of dialysis modes in relation to coronary artery bypass grafting (CABG) surgery among dialysis-dependent patients.This retrospective study enrolled dialysis-dependent patients who underwent CABG from October 2005 to January 2015. All data of demographics, medical history, surgical details, postoperative complications, and in-hospital mortality were analyzed, and patients were categorized as those with or without in-hospital mortality and those with preoperative hemodialysis (HD) or peritoneal dialysis (PD).Of 134 enrolled patients, 25 (18.7%) had in-hospital mortality. Multivariate analyses identified that older age [odds ratio (OR): 1.110, 95% confidence interval (CI): 1.030-1.197, P = .006], previous stroke history (OR: 5.772, 95% CI: 1.643-20.275, P = .006), PD (OR: 19.607, 95% CI: 3.676-104.589, P < .001), and emergent operation (OR: 8.788, 95% CI: 2.697-28.636, P < .001) were statistically significant risk factors for in-hospital mortality among dialysis-dependent patients with CABG surgery. Patients with PD had a higher in-hospital mortality rate (58.3% vs 14.8%, P < .001) and lower 1-year overall survival (33.3% vs 56.6%, P = .031) than did HD patients. The major in-hospital mortality cause was cardiac events among HD patients and septic shock among PD patients.Among dialysis patients who received CABG, those with older age, previous stroke history, PD, and emergent operation had higher risks. Those with PD were prone to poorer in-hospital outcomes after CABG surgery.


Asunto(s)
Puente de Arteria Coronaria , Enfermedad de la Arteria Coronaria , Fallo Renal Crónico , Diálisis Peritoneal , Complicaciones Posoperatorias/epidemiología , Diálisis Renal , Medición de Riesgo/métodos , Factores de Edad , Anciano , Puente de Arteria Coronaria/efectos adversos , Puente de Arteria Coronaria/métodos , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/mortalidad , Enfermedad de la Arteria Coronaria/cirugía , Femenino , Mortalidad Hospitalaria , Humanos , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Diálisis Peritoneal/efectos adversos , Diálisis Peritoneal/métodos , Diálisis Renal/efectos adversos , Diálisis Renal/métodos , Estudios Retrospectivos , Factores de Riesgo , Accidente Cerebrovascular/epidemiología , Taiwán/epidemiología
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