scholarly journals Foldamer-Based Ultrapermeable and Highly Selective Artificial Aquaporins that Exclude Protons

2020 ◽  
Author(s):  
Arundhati Roy ◽  
Jie Shen ◽  
Himanshu Joshi ◽  
Woochul Song ◽  
Yu-Ming Tu ◽  
...  
Keyword(s):  
Water Transport ◽  
Recent Progress ◽  
Ion Selectivity ◽  
High Water ◽  
High Rate ◽  
Water Molecules ◽  
Monovalent Ion ◽  
Hallmark Feature ◽  
Artificial Water ◽  
Made In

The outstanding capacity of aquaporins (AQPs) for mediating highly selective superfast water transport1-7 has inspired recent development of supramolecular monovalent ion-excluding artificial water channels (AWCs). AWC-based bioinspired membranes are proposed for desalination, water purification, and other separations applications8-18. While some recent progress has been made in synthesizing AWCs that approach the water permeability and ion selectivity of AQPs, a hallmark feature of AQPs – high water transport while excluding protons has not been reproduced. We report on a class of biomimetic, helically folded pore-forming polymeric foldamers, that can serve as long sought-after highly selective ultrafast water-conducting channels exceeding those of AQPs (1.1 × 1010 H2O molecules/s for AQP17), with high water over monovalent ion transport selectivity (~108 water molecules over Cl- ion) conferred by the modularly tunable hydrophobicity of the interior pore surface. The best-performing AWC reported here delivers water transport at an exceptionally high rate, 2.5 times that of AQP1, while concurrently rejecting salts (NaCl and KCl) and even protons.

scholarly journals Foldamer-Based Ultrapermeable and Highly Selective Artificial Aquaporins that Exclude Protons

2020 ◽  
Author(s):  
Arundhati Roy ◽  
Jie Shen ◽  
Himanshu Joshi ◽  
Woochul Song ◽  
Yu-Ming Tu ◽  
...  
Keyword(s):  
Water Transport ◽  
Recent Progress ◽  
Ion Selectivity ◽  
High Water ◽  
High Rate ◽  
Water Molecules ◽  
Monovalent Ion ◽  
Hallmark Feature ◽  
Artificial Water ◽  
Made In

The outstanding capacity of aquaporins (AQPs) for mediating highly selective superfast water transport1-7 has inspired recent development of supramolecular monovalent ion-excluding artificial water channels (AWCs). AWC-based bioinspired membranes are proposed for desalination, water purification, and other separations applications8-18. While some recent progress has been made in synthesizing AWCs that approach the water permeability and ion selectivity of AQPs, a hallmark feature of AQPs – high water transport while excluding protons has not been reproduced. We report on a class of biomimetic, helically folded pore-forming polymeric foldamers, that can serve as long sought-after highly selective ultrafast water-conducting channels exceeding those of AQPs (1.1 × 1010 H2O molecules/s for AQP17), with high water over monovalent ion transport selectivity (~108 water molecules over Cl- ion) conferred by the modularly tunable hydrophobicity of the interior pore surface. The best-performing AWC reported here delivers water transport at an exceptionally high rate, 2.5 times that of AQP1, while concurrently rejecting salts (NaCl and KCl) and even protons.

scholarly journals Foldamer-Based Ultrapermeable and Highly Selective Artificial Water Channels that Exclude Protons

2021 ◽  
Author(s):  
Arundhati Roy ◽  
Jie Shen ◽  
Himanshu Joshi ◽  
Woochul Song ◽  
Yu-Ming Tu ◽  
...  
Keyword(s):  
Water Transport ◽  
Ion Selectivity ◽  
High Water ◽  
Water Channels ◽  
High Rate ◽  
Water Molecules ◽  
Monovalent Ion ◽  
Hallmark Feature ◽  
Artificial Water ◽  
Made In

The outstanding capacity of aquaporins (AQPs) for mediating highly selective superfast water transport1-7 has inspired recent development of supramolecular monovalent ion-excluding artificial water channels (AWCs). AWC-based bioinspired membranes are proposed for desalination, water purification, and other separations applications8-18. While some recent progress has been made in synthesizing AWCs that approach the water permeability and ion selectivity of AQPs, a hallmark feature of AQPs – high water transport while excluding protons has not been reproduced. We report on a class of biomimetic, helically folded pore-forming polymeric foldamers, that can serve as long sought-after highly selective ultrafast water-conducting channels exceeding those of AQPs (1.1 × 1010 H2O molecules/s for AQP17), with high water over monovalent ion transport selectivity (~108 water molecules over Cl- ion) conferred by the modularly tunable hydrophobicity of the interior pore surface. The best-performing AWC reported here delivers water transport at an exceptionally high rate, 2.5 times that of AQP1, while concurrently rejecting salts (NaCl and KCl) and even protons.

scholarly journals Response to Comment on “Enhanced water permeability and tunable ion selectivity in subnanometer carbon nanotube porins”

Science ◽  
2018 ◽  
Vol 359 (6383) ◽  
pp. eaaq1241 ◽  
Author(s):  
Ramya H. Tunuguntla ◽  
Yuliang Zhang ◽  
Robert Y. Henley ◽  
Yun-Chiao Yao ◽  
T. Anh Pham ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Experimental Evidence ◽  
Water Transport ◽  
Water Permeability ◽  
Transport Mechanism ◽  
Ion Selectivity ◽  
High Water ◽  
Arrhenius Factor ◽  
Rule Out

Horner and Pohl argue that high water transport rates reported for carbon nanotube porins (CNTPs) originate from leakage at the nanotube-bilayer interface. Our results and new experimental evidence are consistent with transport through the nanotube pores and rule out a defect-mediated transport mechanism. Mechanistic origins of the high Arrhenius factor that we reported for narrow CNTPs at pH 8 require further investigation.

Potential of Nanoparticles in Combating Candida Infections

2019 ◽  
Vol 16 (5) ◽  
pp. 478-491 ◽  
Author(s):  
Faizan Abul Qais ◽  
Mohd Sajjad Ahmad Khan ◽  
Iqbal Ahmad ◽  
Abdullah Safar Althubiani
Keyword(s):  
Targeted Delivery ◽  
Recent Progress ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Fold Increase ◽  
Antifungal Drugs ◽  
Low Toxicity ◽  
Candida Infections ◽  
Made In

Aims: The aim of this review is to survey the recent progress made in developing the nanoparticles as antifungal agents especially the nano-based formulations being exploited for the management of Candida infections. Discussion: In the last few decades, there has been many-fold increase in fungal infections including candidiasis due to the increased number of immunocompromised patients worldwide. The efficacy of available antifungal drugs is limited due to its associated toxicity and drug resistance in clinical strains. The recent advancements in nanobiotechnology have opened a new hope for the development of novel formulations with enhanced therapeutic efficacy, improved drug delivery and low toxicity. Conclusion: Metal nanoparticles have shown to possess promising in vitro antifungal activities and could be effectively used for enhanced and targeted delivery of conventionally used drugs. The synergistic interaction between nanoparticles and various antifungal agents have also been reported with enhanced antifungal activity.

scholarly journals Principles of Different X-ray Phase-Contrast Imaging: A Review

2021 ◽  
Vol 11 (7) ◽  
pp. 2971
Author(s):  
Siwei Tao ◽  
Congxiao He ◽  
Xiang Hao ◽  
Cuifang Kuang ◽  
Xu Liu
Keyword(s):  
Biological Samples ◽  
Phase Contrast ◽  
Recent Progress ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Imaging ◽  
Internal Structures ◽  
X Ray Absorption ◽  
Made In

Numerous advances have been made in X-ray technology in recent years. X-ray imaging plays an important role in the nondestructive exploration of the internal structures of objects. However, the contrast of X-ray absorption images remains low, especially for materials with low atomic numbers, such as biological samples. X-ray phase-contrast images have an intrinsically higher contrast than absorption images. In this review, the principles, milestones, and recent progress of X-ray phase-contrast imaging methods are demonstrated. In addition, prospective applications are presented.

scholarly journals Appropriateness of antibiotics for medical prophylaxis: evaluation of data from the Italian PPS-2

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
A Cremona ◽  
J Garlasco ◽  
I Gintoli ◽  
A D'Ambrosio ◽  
F Quattrocolo ◽  
...  
Keyword(s):  
Empirical Therapy ◽  
Infectious Complications ◽  
High Rate ◽  
National Guidelines ◽  
Prevalence Survey ◽  
Inappropriate Use ◽  
Healthcare Associated ◽  
Evaluation Of Data ◽  
The Eu ◽  
Made In

Abstract Background Antibiotics (AB) are administered for medical prophylaxis (MP) to prevent infectious complications. The second national point prevalence survey (PPS) of healthcare-associated infections and AB use was conducted in Italy in 2016-2017. The survey found MP accounted for nearly 25% of all registered ABs, more than twice the EU/EEA proportion. The aim of this study was to evaluate how many ABs were administered for MP and how frequently general indications were followed. Methods Data from the PPS were used to evaluate the prevalence of indications for MP over the total number of ABs, the proportion - among these indications - of those justified by a motivation in the patients' charts, and the prevalence of ABs considered appropriate for MP. The evaluation was made in 12 hospitals out of 14 participating in the PPS in Piedmont, chosen on the basis of patient traceability. According to national guidelines, the indications for MP that were considered appropriate in this study were: Trimethoprim/sulfamethoxazole for P. carinii pneumonia, Rifaximin for diverticulitis, Penicillin for Streptococcal infections and for splenectomized patients, and Rifampin for TB infections. Results 1844 AB prescriptions were registered among 1334 traceable inpatients in Piedmont. The prevalence of indications for MP was 16.2% and 253 ABs (84.6%) were prescribed with a motivation. Only 3% of ABs registered as MP were appropriate for this indication: Bactrim 2%, Rifaximin 0.3%, Penicillin 0.2% and Rifampin 0.4%. Conclusions This study found an extremely high rate of inappropriate ABs for MP, that will be further investigated through qualitative analysis of medical records to evaluate whether a misunderstanding of the PPS protocol occurred and empirical therapy was confused with MP. Nevertheless, this study highlighted the need for interventions to improve prescribing appropriateness for MP. Key messages This study found that only 2.98% of ABs registered as MP among traceable patients in Piedmont were appropriate for this indication. 15.38% of prescriptions for MP were not justified by a motivation. Interventions to improve prescribing appropriateness for MP could lead to a considerable reduction in inappropriate use of ABs, which is crucial in a country facing hyperendemic levels of AMR.

scholarly journals Bimetallic Ni-Based Catalysts for CO2 Methanation: A Review

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Anastasios I. Tsiotsias ◽  
Nikolaos D. Charisiou ◽  
Ioannis V. Yentekakis ◽  
Maria A. Goula
Keyword(s):  
Low Temperature ◽  
Noble Metals ◽  
Recent Progress ◽  
Low Cost ◽  
Alloy Formation ◽  
Co2 Methanation ◽  
High Performing ◽  
Mobile Sources ◽  
Low Dispersion ◽  
Made In

CO2 methanation has recently emerged as a process that targets the reduction in anthropogenic CO2 emissions, via the conversion of CO2 captured from point and mobile sources, as well as H2 produced from renewables into CH4. Ni, among the early transition metals, as well as Ru and Rh, among the noble metals, have been known to be among the most active methanation catalysts, with Ni being favoured due to its low cost and high natural abundance. However, insufficient low-temperature activity, low dispersion and reducibility, as well as nanoparticle sintering are some of the main drawbacks when using Ni-based catalysts. Such problems can be partly overcome via the introduction of a second transition metal (e.g., Fe, Co) or a noble metal (e.g., Ru, Rh, Pt, Pd and Re) in Ni-based catalysts. Through Ni-M alloy formation, or the intricate synergy between two adjacent metallic phases, new high-performing and low-cost methanation catalysts can be obtained. This review summarizes and critically discusses recent progress made in the field of bimetallic Ni-M (M = Fe, Co, Cu, Ru, Rh, Pt, Pd, Re)-based catalyst development for the CO2 methanation reaction.

scholarly journals Long-lasting, monovalent-selective capacitive deionization electrodes

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Eric N. Guyes ◽  
Amit N. Shocron ◽  
Yinke Chen ◽  
Charles E. Diesendruck ◽  
Matthew E. Suss
Keyword(s):  
Water Treatment ◽  
Ionic Conductivity ◽  
Ion Selectivity ◽  
Single Step ◽  
Carbon Electrodes ◽  
Capacitive Deionization ◽  
Treatment Technologies ◽  
Porous Carbon Electrodes ◽  
Monovalent Ion ◽  
Direct Use

AbstractEmerging water purification applications often require tunable and ion-selective technologies. For example, when treating water for direct use in irrigation, often monovalent Na+ must be removed preferentially over divalent minerals, such as Ca2+, to reduce both ionic conductivity and sodium adsorption ratio (SAR). Conventional membrane-based water treatment technologies are either largely non-selective or not dynamically tunable. Capacitive deionization (CDI) is an emerging membraneless technology that employs inexpensive and widely available activated carbon electrodes as the active element. We here show that a CDI cell leveraging sulfonated cathodes can deliver long-lasting, tunable monovalent ion selectivity. For feedwaters containing Na+ and Ca2+, our cell achieves a Na+/Ca2+ separation factor of up to 1.6. To demonstrate the cell longevity, we show that monovalent selectivity is retained over 1000 charge–discharge cycles, the highest cycle life achieved for a membraneless CDI cell with porous carbon electrodes to our knowledge, while requiring an energy consumption of ~0.38 kWh/m3 of treated water. Furthermore, we show substantial and simultaneous reductions of ionic conductivity and SAR, such as from 1.75 to 0.69 mS/cm and 19.8 to 13.3, respectively, demonstrating the potential of such a system towards single-step water treatment of brackish and wastewaters for direct use in irrigation.

scholarly journals Solid-state nanopore systems: from materials to applications

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yuhui He ◽  
Makusu Tsutsui ◽  
Yue Zhou ◽  
Xiang-Shui Miao
Keyword(s):  
Solid State ◽  
Recent Progress ◽  
State Of The Art ◽  
Ion Selectivity ◽  
Dna Origami ◽  
Fundamental Interest ◽  
Reverse Electrodialysis ◽  
Promising Application ◽  
Flow Through ◽  
Wall Materials

AbstractIon transport and hydrodynamic flow through nanometer-sized channels (nanopores) have been increasingly studied owing to not only the fundamental interest in the abundance of novel phenomena that has been observed but also their promising application in innovative nanodevices, including next-generation sequencers, nanopower generators, and memristive synapses. We first review various kinds of materials and the associated state-of-the-art processes developed for fabricating nanoscale pores, including the emerging structures of DNA origami and 2-dimensional nanopores. Then, the unique transport phenomena are examined wherein the surface properties of wall materials play predominant roles in inducing intriguing characteristics, such as ion selectivity and reverse electrodialysis. Finally, we highlight recent progress in the potential application of nanopores, ranging from their use in biosensors to nanopore-based artificial synapses.

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