Riverbank filtration (RBF) schemes for the production of drinking water are increasingly challenged by new constituents of concern, such as organic micropollutants and pathogens in the source water ...and hydrological flow variations due to weather extremes. RBF and new technology components are integrated and monitoring and operating regimes are adopted to further optimize water treatment in bank filtration schemes for these new requirements. This Special Issue presents results from the EU project AquaNES “Demonstrating synergies in combined natural and engineered processes for water treatment systems” (www.aquanes.eu). Additionally, papers from other research groups cover the efficiency of bank filtration and post-treatment, advantages and limitations of combining natural and engineered processes, parameter-specific assessment of removal rates during bank filtration, and the design and operation of RBF wells. The feasibility, design, and operation of RBF schemes under specific site conditions are highlighted for sites in the US, India, and South Korea
On construit une famille de reprèsentations localement analytiques indècomposables de ${\rm GL}_3(\Bbb{Q}_p)$ toutes contenant ${\rm Alg}\otimes{\rm Steinberg}$ en sous-objet où Alg est une ...reprèsentation algèbrique irrèductible fixèe et Steinberg la reprèsentation spèciale lisse. Soit $\rho_p$ une reprèsentation $p$-adique semi-stable de dimension $3$ de ${\rm Gal}(\overline{\Bbb{Q}_p}/\Bbb{Q}_p)$ dont la reprèsentation de Weil-Deligne associèe correspond à Steinberg par la correspondance de Langlands locale classique et dont la filtration de Hodge est non critique. Lorsque $\rho_p$ provient d’une reprèsentation automorphe $\pi$ de $G(\Bbb{A}_{\Bbb{Q}})$ (pour un groupe unitaire compact $G_{/\Bbb{Q}}$ dèployè en $p$) et $U^p\subset G(\Bbb{A}_{\Bbb{Q}}^{\infty,p})$ est un niveau hors $p$ fixè tel que $\pi$ est l’unique reprèsentation de son $L$-paquet global vèrifiant $\pi^{U^p}\ne 0$, on montre qu’une seule des reprèsentations localement analytiques de la famille ci-dessus apparaît dans le sous-espace Hecke-isotypique associè de la cohomologie complètèe en niveau $U^p$. On conjecture que cette reprèsentation de ${\rm GL}_3(\Bbb{Q}_p)$ ne dèpend que de la filtration de Hodge sur le $(\varphi,N)$-module filtrè $D_{\rm st}(\rho_p)$ et qu’elle la dètermine complètement.
The active filter has different connection methods, and the methods used are also various. With the deepening of research, more novel filtering methods are proposed and applied, which enhances the ...efficiency and rapidity of filtering. At present, China has made great progress in harmonic suppression. In the face of the fact that harmonic problems are becoming more and more serious, the research of filtering technology and the popularization and application of filtering equipment are urgently needed.
In modern society, traffic and transportation and the manufacturing industry and construction industries continuously release large amounts of dust and particles into the atmosphere, which can cause ...heavy air pollution, leading to health hazards. The haze disaster, a serious problem in developing countries such as China and India, has become one of the main issues of global environmental pollution in recent decades. Many air filtration technologies have been developed. Air filtration using electrospun fibers that intercept fine particles/volatile organic gases/bacterium is a relatively new, but highly promising, technique. Due to their interconnected nanoscale pore structures, highly specific surface areas, fine diameters, and porous structure as well as their ability to incorporate active chemistry on a nanoscale surface, electrospun fibers are becoming a promising versatile platform for air filtration. In this review, following a short introduction concerning the need for air filtration and filtration theory and mechanism, electrospun nanofibers membranes for air filtration have been highlighted, including the preparation (electrospinning process) and the parameters relevant to filtration efficacy. Additionally, various types (function) of the electrospun air filtration membranes have been classified in detail. Furthermore, their potential in the filtration of fine particles and chemical pollutants has been discussed. Finally, the challenges of their practical application and the future prospects have been summarized. Given that some advanced electrospun air filtration nanofibrous membranes exist for treating different contaminants from various types of polluted atmosphere, it is believed that they should make a significant contribution in protection against air pollution.
Various types and properties of the electrospun nanofibrous membranes for different contributions to remove airborne contaminants.
Loss of normal kidney function affects more than 10% of the population and contributes to morbidity and mortality. Kidney diseases are currently treated with immunosuppressive agents, ...antihypertensives and diuretics with partial but limited success. Most kidney disease is characterized by breakdown of the glomerular filtration barrier (GFB). Specialized podocyte cells maintain the GFB, and structure-function experiments and studies of intercellular communication between the podocytes and other GFB cells, combined with advances from genetics and genomics, have laid the groundwork for a new generation of therapies that directly intervene at the GFB. These include inhibitors of apolipoprotein L1 (APOL1), short transient receptor potential channels (TRPCs), soluble fms-like tyrosine kinase 1 (sFLT1; also known as soluble vascular endothelial growth factor receptor 1), roundabout homologue 2 (ROBO2), endothelin receptor A, soluble urokinase plasminogen activator surface receptor (suPAR) and substrate intermediates for coenzyme Q10 (CoQ
). These molecular targets converge on two key components of GFB biology: mitochondrial function and the actin-myosin contractile machinery. This Review discusses therapies and developments focused on maintaining GFB integrity, and the emerging questions in this evolving field.
Aims
To provide a reliable, reproducible and centrifuge‐free filtration protocol for clarification of large volumes of bacterial cultures.
Methods and Results
Four experiments were designed to ...compare different techniques enabling clarification of Escherichia coli cultures using as a benchmark the concentration and quality of bacterial outer membrane vesicles (OMVs). The experiments were designed to examine the performance of different extraction methods on large volume (≥1 L) filtrations of bacterial culture media. Performance parameters included filtration flow rates, sterility testing and characterization of the filtrates by: (i) SDS‐PAGE, (ii) cryogenic transmission electron microscopy, (iii) nanoparticle tracking analysis and (iv) Qubit protein quantification. The experiments revealed that: (i) addition of the filter aid Diatomaceous Earth to the bacterial cultures improved filtration flow rates significantly and eliminated the need for centrifugation prior to filtration; (ii) sterile filtration was successful as no bacterial passage was identified through the membrane filter; (iii) centrifuge‐free filtrates contained an increased amount of OMVs compared to centrifuged filtrates.
Conclusions
In comparison to conventional centrifuge‐based protocols, the clarification method presented has universal applicability for a broad range of microbial extraction procedures, regardless of the volume of culture harvested. Moreover, the decreased amount of OMVs presented in the filtrates following centrifugation step provides an additional argument in favour of a centrifuge‐free approach.
Significance and Impact of the Study
Sterile filtration is a universal method for the clarification of bacterial cultures. Common challenges related to filtration include filter clogging and long processing times, due to limited centrifugation capacity, which can affect product quality. The proposed protocol is likely to ensure a highly effective filtration process and could be a novel approach in improving the filtrate products without the need of centrifugation.
In response to a national call for re-evaluation of the use of race in clinical algorithms, the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) established a Task Force ...to reassess inclusion of race in the estimation of glomerular filtration rate (GFR) in the United States and its implications for diagnosis and management of patients with, or at risk for, kidney diseases.
The Task Force organized its activities over 10 months in phases to (1) clarify the problem and evidence regarding GFR estimating equations in the United States (described previously in an interim report), and, in this final report, (2) evaluate approaches to address use of race in GFR estimation, and (3) provide recommendations. We identified 26 approaches for the estimation of GFR that did or did not consider race and narrowed our focus, by consensus, to 5 of those approaches. We holistically evaluated each approach considering 6 attributes: assay availability and standardization; implementation; population diversity in equation development; performance compared with measured GFR; consequences to clinical care, population tracking, and research; and patient centeredness. To arrive at a unifying approach to estimate GFR, we integrated information and evidence from many sources in assessing strengths and weaknesses in attributes for each approach, recognizing the number of Black and non-Black adults affected.
(1) For US adults (>85% of whom have normal kidney function), we recommend immediate implementation of the CKD-EPI creatinine equation refit without the race variable in all laboratories in the United States because it does not include race in the calculation and reporting, included diversity in its development, is immediately available to all laboratories in the United States, and has acceptable performance characteristics and potential consequences that do not disproportionately affect any one group of individuals. (2) We recommend national efforts to facilitate increased, routine, and timely use of cystatin C, especially to confirm estimated GFR in adults who are at risk for or have chronic kidney disease, because combining filtration markers (creatinine and cystatin C) is more accurate and would support better clinical decisions than either marker alone. If ongoing evidence supports acceptable performance, the CKD-EPI eGFR–cystatin C (eGFRcys) and eGFR creatinine–cystatin C (eGFRcr-cys_R) refit without the race variables should be adopted to provide another first-line test, in addition to confirmatory testing. (3) Research on GFR estimation with new endogenous filtration markers and on interventions to eliminate race and ethnic disparities should be encouraged and funded. An investment in science is needed for newer approaches that generate accurate, unbiased, and precise GFR measurement and estimation without the inclusion of race, and that promote health equity and do not generate disparate care.
This unified approach, without specification of race, should be adopted across the United States. High-priority and multistakeholder efforts should implement this solution.
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Bio-based PA-56 membrane composed of the ultrathin 2D nanonets and stable cavity structures can effectively filtrate ultrafine airborne particles with high filtration efficiency, low air resistance, ...and long service life. Display omitted
•Bio-based PA-56 NF/N membrane was fabricated via one-step electrospinning/netting.•2D nanonets (∼20nm) and stable cavity structures were synchronously constructed.•Superlight weight and mechanical robustness.•High filtration efficiency (99.995%) and low pressure drop (111Pa).•Surface filtration and dust-cleaning regeneration ability.
Nanofibrous media that both possess high airborne particle interception efficiency and robust air permeability would have broad technological implications for areas ranging from individual protection and industrial security to environmental governance; however, creating such filtration media has proved extremely challenging. Here we report a strategy to construct the bio-based polyamide-56 nanofiber/nets (PA-56 NFN) membranes with bimodal structures for effective air filtration via one-step electrospinning/netting. The PA-56 membranes are composed of completely covered two-dimensional (2D) ultrathin (∼20nm) nanonets which are optimized by facilely regulating the solution concentration, and the bonded scaffold fibers constructed cavity structures which are synchronously created by using the CH3COOH inspiration. With integrated properties of small aperture, high porosity, and bonded scaffold, the resulting PA-56 NFN membranes exhibit high filtration efficiency of 99.995%, low pressure drop of 111Pa, combined with large dust holding capacity of 49g/m2 and dust-cleaning regeneration ability, for filtrating ultrafine airborne particles in the most safe manner involving sieving principle and surface filtration. The successful synthesis of PA-56 NFN medium would not only make it a promising candidate for air filtration, but also provide new insights into the design and development of nanonet-based bimodal structures for various applications.
Membrane filtration provides an effective solution for removing pollutants from water but is limited by serious membrane fouling. In this work, an effective approach was used to mitigate membrane ...fouling by integrating membrane filtration with electropolarization using an electroconductive nanocarbon-based membrane. The electropolarized membrane (EM) by alternating square-wave potentials between +1.0 V and −1.0 V with a pulse width of 60 s exhibited a permeate flux 8.1 times as high as that without electropolarization for filtering feed water containing bacteria, which confirms the ability of the EM to achieve biofouling mitigation. Moreover, the permeate flux of EM was 1.5 times as high as that without electropolarization when filtrating natural organic matter (NOM) from water, and demonstrated good performance in organic fouling mitigation with EM. Furthermore, the EM was also effective for complex fouling mitigation in filtering water containing coexisting bacteria and NOM, and presented an increased flux rate 1.9 times as high as that without electropolarization. The superior fouling mitigation performance of EM was attributed to the synergistic effects of electrostatic repulsion, electrochemical oxidation and electrokinetic behaviors. This work opens an effective avenue for membrane fouling mitigation of water-treatment membrane filtration systems.
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•CNT/ceramic hollow fiber membrane (CHFM) was successfully prepared.•Membrane filtration was successfully integrated with electric field driving.•Membrane fouling was effectively mitigated in CHFM by electric field driving.•Cost-efficient approach was developed for enhancing filtration performance.
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