scholarly journals Bio-Based and Robust Polydopamine Coated Nanocellulose/ Amyloid Composite Aerogel for Fast and Wide-Spectrum Water Purification

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3442
Author(s):  
Maxime Sorriaux ◽  
Mathias Sorieul ◽  
Yi Chen

Water contamination resulting from human activities leads to the deterioration of aquatic ecosystems. This restrains the access to fresh water, which is the leading cause of mortality worldwide. In this work, we developed a bio-based and water-resistant composite aerogel from renewable nanofibrils for water remediation application. The composite aerogel consists of two types of cross-linked nanofibrils. Poly(dopamine)-coated cellulose nanofibrils and amyloid protein nanofibrils are forming a double networked crosslinked via periodate oxidation. The resulting aerogel exhibits good mechanical strength and high pollutants adsorption capability. Removal of dyes (rhodamine blue, acriflavine, crystal violet, malachite green, acid fuchsin and methyl orange), organic traces (atrazine, bisphenol A, and ibuprofen) and heavy metal ions (Pb(II) and Cu(II)) from water was successfully demonstrated with the composite aerogel. More specifically, the bio-based aerogel demonstrated good adsorption efficiencies for crystal violet (93.1% in 30 min), bisphenol A (91.7% in 5 min) and Pb(II) ions (94.7% in 5 min), respectively. Furthermore, the adsorption–desorption performance of aerogel for Pb(II) ions demonstrates that the aerogel has a high reusability as maintains satisfactory removal performances. The results suggest that this type of robust and bio-based composite aerogel is a promising adsorbent to decontaminate water from a wide range of pollutants in a sustainable and efficient way.

2019 ◽  
Vol 14 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Hidayat Hussain ◽  
Ivan R. Green ◽  
Muhammad Saleem ◽  
Khanzadi F. Khattak ◽  
Muhammad Irshad ◽  
...  

Background: Cucurbitacins belong to a group of tetracyclic triterpenoids that display a wide range of biological effects. In the past, numerous cucurbitacins have been isolated from natural sources and many active compounds have been synthesized using the privileged scaffold in order to enhance its cytotoxic effects. Objective: his review covers patents on the therapeutic effects of natural cucurbitacins and their synthetic analogs published during the past decade. By far, the majority of patents published are related to cancer and Structure-Activity Relationships (SAR) of these compounds are included to lend gravitas to this important class of natural products. Methods: The date about the published patents was downloaded via online open access patent databases. Results: Cucurbitacins display significant cytotoxic properties, in particular cucurbitacins B and D which possess very potent effects towards a number of cancer cells. Numerous cucurbitacins isolated from natural sources have been derivatized through chemical modification at the C(2)-OH and C(25)- OH groups. Most importantly, an acyl ester of the C(25)-OH and, iso-propyl, n-propyl and ethyl ether groups of the C(2)-OH demonstrated the most increased cytotoxic activity. Conclusion: The significant cytotoxic effects of natural and semi-synthetic cucurbitacins make them attractive as new drug candidates. Moreover, cucurbitacins have the capability to form conjugates with other anticancer drugs which will synergistically enhance their anticancer effects. The authors believe that in order to get lead compounds, there should be a greater focus on the synthesis of homodimers, heterodimers, and halo derivatives of cucurbitacins. In the opinion of the authors the analysis of the published patents on the cucurbitacins indicates that these compounds can be developed into a regimen to treat a wide spectrum of cancers.


2021 ◽  
Vol 9 ◽  
pp. 205031212110225
Author(s):  
Mark A Pianka ◽  
Joseph Serino ◽  
Steven F DeFroda ◽  
Blake M Bodendorfer

Greater trochanteric pain syndrome is a common cause of lateral hip pain, encompassing a spectrum of disorders, including trochanteric bursitis, abductor tendon pathology, and external coxa saltans. Greater trochanteric pain syndrome is primarily a clinical diagnosis, and careful clinical examination is essential for accurate diagnosis and treatment. A thorough history and physical exam may be used to help differentiate greater trochanteric pain syndrome from other common causes of hip pain, including osteoarthritis, femoroacetabular impingement, and lumbar stenosis. Although not required for diagnosis, plain radiographs and magnetic resonance imaging may be useful to exclude alternative pathologies or guide treatment of greater trochanteric pain syndrome. The majority of patients with greater trochanteric pain syndrome respond well to conservative management, including physical therapy, non-steroidal anti-inflammatory drugs, and corticosteroid injections. Operative management is typically indicated in patients with chronic symptoms refractory to conservative therapy. A wide range of surgical options, both open and endoscopic, are available and should be guided by the specific etiology of pain. The purpose of this review is to highlight pertinent clinical and radiographic features used in the diagnosis and management of greater trochanteric pain syndrome. In addition, treatment indications, techniques, and outcomes are described.


Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1831-1853
Author(s):  
Jaeho Jeon ◽  
Yajie Yang ◽  
Haeju Choi ◽  
Jin-Hong Park ◽  
Byoung Hun Lee ◽  
...  

AbstractTwo-dimensional (2D) layers of transition metal carbides, nitrides, or carbonitrides, collectively referred to as MXenes, are considered as the new family of 2D materials for the development of functional building blocks for optoelectronic and photonic device applications. Their advantages are based on their unique and tunable electronic and optical properties, which depend on the modulation of transition metal elements or surface functional groups. In this paper, we have presented a comprehensive review of MXenes to suggest an insightful perspective on future nanophotonic and optoelectronic device applications based on advanced synthesis processes and theoretically predicted or experimentally verified material properties. Recently developed optoelectronic and photonic devices, such as photodetectors, solar cells, fiber lasers, and light-emitting diodes are summarized in this review. Wide-spectrum photodetection with high photoresponsivity, high-yield solar cells, and effective saturable absorption were achieved by exploiting different MXenes. Further, the great potential of MXenes as an electrode material is predicted with a controllable work function in a wide range (1.6–8 eV) and high conductivity (~104 S/cm), and their potential as active channel material by generating a tunable energy bandgap is likewise shown. MXene can provide new functional building blocks for future generation nanophotonic device applications.


Axioms ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 44
Author(s):  
Gana Gecheva ◽  
Miroslav Hristov ◽  
Diana Nedelcheva ◽  
Margarita Ruseva ◽  
Boyan Zlatanov

We have obtained a new class of ordered pairs of multivalued maps that have pairs of coupled fixed points. We illustrate the main result with two examples that cover a wide range of models. We apply the main result in models in duopoly markets to get a market equilibrium and in aquatic ecosystems, also to get an equilibrium.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Denise S. Cordeiro ◽  
Fernando L. Cassio ◽  
Larissa Ciccotti ◽  
Thiago L. R. Hewer ◽  
Paola Corio ◽  
...  

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1125
Author(s):  
Raluca Nicu ◽  
Florin Ciolacu ◽  
Diana E. Ciolacu

Nanocelluloses (NCs), with their remarkable characteristics, have proven to be one of the most promising “green” materials of our times and have received special attention from researchers in nanomaterials. A diversity of new functional materials with a wide range of biomedical applications has been designed based on the most desirable properties of NCs, such as biocompatibility, biodegradability, and their special physicochemical properties. In this context and under the pressure of rapid development of this field, it is imperative to synthesize the successes and the new requirements in a comprehensive review. The first part of this work provides a brief review of the characteristics of the NCs (cellulose nanocrystals—CNC, cellulose nanofibrils—CNF, and bacterial nanocellulose—BNC), as well as of the main functional materials based on NCs (hydrogels, nanogels, and nanocomposites). The second part presents an extensive review of research over the past five years on promising pharmaceutical and medical applications of nanocellulose-based materials, which have been discussed in three important areas: drug-delivery systems, materials for wound-healing applications, as well as tissue engineering. Finally, an in-depth assessment of the in vitro and in vivo cytotoxicity of NCs-based materials, as well as the challenges related to their biodegradability, is performed.


NANO ◽  
2021 ◽  
pp. 2150050
Author(s):  
Zhaoyu Han ◽  
Sen Li ◽  
Shaoxian Yin ◽  
Zhi-Qin Wang ◽  
Yanfei Cai ◽  
...  

Being the newest member of the 2D materials family, 2D-nanosheet possesses many distinctive physical and chemical properties resulting in a wide range of potential applications. Recently, it was discovered that 2D COF can adsorb single-stranded DNA (ss-DNA) efficiently as well as usefully to quench fluorophores. These properties make it possible to prepare DNA-based optical biosensors using 2D COF. While practical analytical applications are being demonstrated, the fundamental understanding of binding between 2D COF and DNA in solution received relatively less attention. In this work, we carried out a systematic study to understand the adsorption and desorption kinetic, mechanism, and influencing factors of ss-DNA on the surface of 2D COF. We demonstrated that shorter DNAs are adsorbed more rapidly and bind more tightly to the surface of 2D COF. The adsorption is favored by a higher pH. The different buffer types also can affect the adsorption. In Tris-HCl solution, the adsorption reached highest efficiency. By adding the complementary DNA (cDNA), desorption of the absorbed DNA on 2D COF can be achieved. Further, desorption efficiency can also be exchanged by various surfactant in solution. These findings are important for further understanding of the interactions between DNA and COFs and for the optimization of DNA and COF-based devices and sensors.


Author(s):  
Mohsina Abed ◽  
Sara Yousuf

Meropenem is a new Carbapenem antibacterial agent with wide spectrum of activity for intravenous administration. It is synthetic derivative of Thienamycin. Three analogues of Meropenem are evaluated and active against 18 bacterial strains. Meropenem causes rapid bacterial cell death by covalently binding to penicillin binding proteins (PBS). Structural modification at C-2 position, produced double promoiety prodrug of Meropenem and increases bioavailability of oral administration. Other forms of drug such as liposome and nanoparticles are also available with enhanced absorption. 14C labelled Meropenem prepared from 14C Dimethylamine hydrochloride is used for the analysis of M. tuberculosis transpeptidase. ICI213,689 is the only metabolite of Meropenem and it is inactive. Meropenem penetrates well into the body fluids and tissues including cerebrospinal fluid. Its bioavailability is 100% on intravenous administration. Hence it is used in the treatment of meningitis, febrile neutropenia, anthrax and various other skin and skin structure infections. Dosage reduction is required in patient with reduced renal function but not in hepatic impairment. Seizures, gastrointestinal haemorrhage are observed in patients. Vabmoere is the combination of Meropenem and Vaborbactam which is active against the Carbapenem resistant Enterobacteriacea. Meropenem is an effective broad-spectrum antibacterial drug for the treatment of wide range of infection including polymicrobial infection in both children and adult.


Author(s):  
Shu-Ying Tseng ◽  
Po-Yu Liu ◽  
Yi-Hsuan Lee ◽  
Zong-Yen Wu ◽  
Chiu-Chen Huang ◽  
...  

Shewanella algaeis a rod-shaped Gram-negative marine bacterium frequently found in nonhuman sources such as aquatic ecosystems and has been shown to be the pathogenic agent in various clinical cases due to the ingestion of raw seafood. The results of this study showed thatS. algaewas present in approximately one in four samples, including water and shellfish samples. Positive reactions (API systems) inS. algaestrains were seen for gelatinase (gelatin); however, negative reactions were found for indole production (tryptophan).S. algaeis adapted to a wide range of temperatures (4°C, 25°C, 37°C, and 42°C) and salinity. Temperature is a key parameter in the pathogenicity ofS. algaeas it appears to induce hemolysis at 25°C and 37°C.S. algaeexhibits pathogenic characteristics at widely varying temperatures, which suggests that it may have the ability to adapt to climate change.


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