Arc-poration improves transdermal delivery of biomolecules.

BACKGROUND: To increase skin permeability, various transdermal delivery techniques have been developed. However, due to the stratum corneum as a skin barrier, transdermal delivery remains limited. AIMS: In this study, we evaluated efficacy and safety of arc-poration as a novel technique disrupting the stratum corneum. RESULTS: Optical images and histological analysis using reconstituted human skin and porcine skin showed that the treatment of arc-poration created micropores with an average diameter of approximately 100 µm only to the depth of the stratum corneum, but not viable epidermis. In addition, the Franz diffusion cell experiment using reconstituted human skin showed a remarkable increase in permeability following pretreatment with arc-poration. Clinical results clearly demonstrated the enhancement of the skin-improving effect of cosmetics by pretreatment of arc-poration in terms of gloss, hydration, flakiness, texture, tone, tone evenness, and pigmentation of skin, without causing abnormal skin responses. The concentration of ozone and nitrogen oxides generated by arc-poration was below the permissible value for the human body. CONCLUSIONS: Arc-poration can increase skin permeability by creating stratum corneum-specific micropores, which can enhance the skin-improving effect of cosmetics without adverse responses.

Do brushings taken during bronchoscopy for suspected primary lung cancer increase diagnostic yield? An audit of real-world clinical practice.

We reviewed clinical records to determine whether the use of bronchial brushings improved diagnostic yield in a setting where bronchoscopy for suspected primary lung cancer is routinely guided by prior chest computed tomography but endobronchial ultrasound-guided sampling is unavailable. For 29% of cases who had brushings and at least one other test taken (bronchial biopsies or washings), the histological diagnosis was made solely on the basis of samples obtained by brushings.

Enhanced catalytic oxidation of naproxen via activation of peroxymonosulfate by Fe-based metal-organic framework aerogels functionalized with Ag nanoparticles.

In this study, Ag3PO4 and Fe-based metal-organic frameworks (MOFs)-functionalized three-dimensional (3D) porous gelatin aerogels (Ag/Fe@GMA) were fabricated and used as adsorbents and catalysts for the activation of peroxymonosulfate (PMS) for naproxen (NPX) removal from water. The morphology, crystallinity, surface functional groups, and surface chemical element compositions of the fabricated Ag/Fe@GMA was evaluated using various analytical techniques. Our results showed that as an adsorbent, Ag/Fe@GMA showed a 18.0 % higher NPX adsorption capacity compared with the pristine aerogels. This can be attributed to the well-embedded Ag3PO4 and MOFs, indicating a stronger interaction between functionalized aerogels and NPX. After adsorption, 99.9 % of total NPX removal was achieved within 15 min by activating PMS and effectively generating •OH and •SO4- in water. The PMS/Ag/Fe@GMA aerogel system also showed high removal performance for rhodamine B (99.5 %) and tetracycline (93.7 %). Moreover, the Ag/Fe@GMA aerogels showed excellent reusability to achieve 95.7 % NPX removal efficiency after six times of recycling. This study revealed that the Ag/Fe@GMA aerogels had good potential for PMS activation and NPX removal. In particular, as an alternative to powdery materials, 3D shape of Ag/Fe@GMA with excellent reusability facilitates its application in the treatment of water contaminated with organic contaminants.

Adsorptive and photocatalytic performance of cobalt-doped ZnTiO3/Ti3C2Tx MXene nanohybrids towards tetracycline: Kinetics and mechanistic insight.

Tetracycline (TC) antibiotics are widely used in animal husbandry and can cause environmental risk due to its high ecological toxicity and persistence. In this study, cobalt doped/ZnTiO3 (ZTO)/Ti3C2Tx MXene (ZCxTM, x indicates wt% of Co loading) was synthesized and explored to remove TC by adsorption and photocatalysis under visible light irradiation. The as-prepared ZC5TM was characterized using various analytical techniques, and key operating parameters such as solution pH, background ions, and temperature were systematically investigated. Interestingly, ZC5TM (14.9 mg/g) showed excellent adsorption capacity for TC, which was higher than activated carbon (7.7 mg/g), ZTO (4.9 mg/g), ZC3T (5.2 mg/g), ZC5T (5.3 mg/g), MXene (12.1 mg/g), ZTOM (12.5 mg/g), and ZC3TM (12.9 mg/g). The pseudo-second-order kinetics and Langmuir isotherm models well explained the effect of contact time and initial concentrations on the adsorption of TC. The adsorption process was primarily through the electrostatic attraction, surface complexation, and hydrogen bonding. In addition, MXene and Co doped on ZTO served as co-catalyst and reduced recombination rate of photo-generated e--h+ pairs by the intimate interface of its heterojunction. Thus, ZC5TM was highly effective for the photocatalytic degradation of residual TC after adsorption by showing 18% TC degradation rate, compared to 8% and 9% degradation rate for ZTO and MXene, respectively. There results finally support the feasible use of ZC5TM as efficient adsorbent and photocatalyst in removal of TC in wastewater.

U(VI) binding onto electrospun polymers functionalized with phosphonate surfactants.

We previously observed that phosphonate functionalized electrospun nanofibers can uptake U(VI), making them promising materials for sensing and water treatment applications. Here, we investigate the optimal fabrication of these materials and their mechanism of U(VI) binding under the influence of environmentally relevant ions (e.g., Ca2+ and CO 3 2 - ). We found that U(VI) uptake was greatest on polyacrylonitrile (PAN) functionalized with longer-chain phosphonate surfactants (e.g., hexa- and octadecyl phosphonate; HDPA and ODPA, respectively), which were better retained in the nanofiber after surface segregation. Subsequent uptake experiments to better understand specific solid-liquid interfacial interactions were carried out using 5 mg of HDPA-functionalized PAN mats with 10 µM U at pH 6.8 in four systems with different combinations of solutions containing 5 mM calcium (Ca2+) and 5 mM bicarbonate ( HCO 3 - ). U uptake was similar in control solutions containing no Ca2+ and HCO 3 - (resulting in 19 ± 3% U uptake), and in those containing only 5 mM Ca2+ (resulting in 20 ± 3% U uptake). A decrease in U uptake (10 ± 4% U uptake) was observed in experiments with HCO 3 - , indicating that UO2-CO3 complexes may increase uranium solubility. Results from shell-by-shell EXAFS fitting, aqueous extractions, and surface-enhanced Raman scattering (SERS) indicate that U is bound to phosphonate as a monodentate inner sphere surface complex to one of the hydroxyls in the phosphonate functional groups. New knowledge derived from this study on material fabrication and solid-liquid interfacial interactions will help to advance technologies for use in the in-situ detection and treatment of U in water.

Synthesis, performance, and mechanisms of strontium ferrite-incorporated zeolite imidazole framework (ZIF-8) for the simultaneous removal of Pb(II) and tetracycline.

In this study, strontium ferrite (SF)-incorporated zeolite imidazole framework (ZIF-8) (SFZIF-8) that can simultaneously uptake Pb(II) and tetracycline (TC) in solution was synthesized and characterized. The physicochemical properties of the as-prepared SFZIF-8 were characterized by various functional groups, higher average pore diameter (3.414 nm), and stronger negative charge (-30.5 mV). Adsorption kinetics, isotherms, effect of various water conditions including solution pH and temperature, and reusability were studied to evaluate its adsorption performance. The adsorption capacity of SFZIF-8 was compared with that of commonly used adsorbents (powder and granular activated carbon). SFZIF-8 showed much higher adsorption performance (429.6 mg/g and 433.4 mg/g for Pb(II) and TC, respectively) than powder activated carbon (129.9 mg/g and 142.0 mg/g for Pb(II) and TC, respectively) and granular activated carbon (249.3 mg/g and 263.0 mg/g for Pb(II) and TC, respectively) in Pb(II) and TC binary solutions. The SFZIF-8 adsorption behaviors for the removal of Pb(II) and TC were explained by the pseudo-first-order and Langmuir models from the adsorption kinetics and isotherm experiments, respectively. The regenerated SFZIF-8 exhibited a competitive performance even after the third cycle. These results indicate that Pb(II) and TC can be removed with SFZIF-8 via electrostatic attraction, surface complexation, hydrogen bonding, and π-π interactions. Therefore, by exhibiting effective and efficient adsorption performance, SFZIF-8 nanocomposites can be utilized as alternative and promising adsorbents for the simultaneous removal of both Pb(II) and TC.

Recent advances and remaining barriers to the development of electrospun nanofiber and nanofiber composites for point-of-use and point-of-entry water treatment systems.

In this review, we focus on electrospun nanofibers as a promising material alternative for the niche application of decentralized, point-of-use (POU) and point-of-entry (POE) water treatment systems. We focus our review on prior work with various formulations of electrospun materials, including nanofibers of carbon, pure metal oxides, functionalized polymers, and polymer-metal oxide composites, that exhibit analogous performance to media (e.g., activated carbon, ion exchange resins) commonly used in commercially available, certified POU/POE devices for contaminants including organic pollutants, metals (e.g., lead) and persistent oxyanions (e.g., nitrate). We then analyze the relevant strengths and remaining research and development opportunities of the relevant literature based on an evaluation framework that considers (i) performance comparison to commercial analogs; (ii) appropriate pollutant targets for POU/POE applications; (iii) testing in flow-through systems consistent with POU/POE applications; (iv) consideration of water quality effects; and (v) evaluation of material strength and longevity. We also identify several emerging issues in decentralized water treatment where nanofiber-based POU/POE devices could help meet existing needs including their use for treatment of uranium, disinfection, and in electrochemical treatment systems. To date, research has demonstrated promising material performance toward relevant targets for POU/POE applications, using appropriate aquatic matrices and considering material stability. To fully realize their promise as an emerging treatment technology, our analysis of the available literature reveals the need for more work that benchmarks nanofiber performance against established commercial analogs, as well as fabrication and performance validation at scales and under conditions simulating POU/POE water treatment.

Review of adsorption-membrane hybrid systems for water and wastewater treatment.

Adsorption is an effective method for the removal of inorganic and organic contaminants and has been commonly used as a pretreatment method to improve contaminant removal and control flux during membrane filtration. Over the last two decades, many researchers have reported the use of hybrid systems comprising various adsorbents and different types of membranes, such as nanofiltration (NF), ultrafiltration (UF), and microfiltration (MF) membranes, to remove contaminants from water. However, a comprehensive evaluation of the removal mechanisms and effects of the operating conditions on the transport of contaminants through hybrid systems comprising various adsorbents and NF, UF, or MF membranes has not been performed to date. Therefore, a systematic review of contaminant removal using adsorption-membrane hybrid systems is critical, because the transport of inorganic and organic contaminants via the hybrid systems is considerably affected by the contaminant properties, water quality parameters, and adsorbent/membrane physicochemical properties. Herein, we provide a comprehensive summary of the most recent studies on adsorption-NF/UF/MF membrane systems using various adsorbents and membranes for contaminant removal from water and wastewater and highlight the future research directions to address the current knowledge gap.

Effect of single and multilayered Ti3C2TX MXene as a catalyst and adsorbent on enhanced sonodegradation of diclofenac and verapamil.

Single and multilayered Ti3C2TX MXene (referred to as SLM and MLM in this study, respectively) was applied as catalysts in the ultrasonic (US) process to treat selected pharmaceutical compounds including diclofenac and verapamil (VRP). Due to solid surface, elemental composition, and functional groups of Ti3C2TX MXene, the free OH• production was increased by 48.8% for the US treatment with SLM and 59.8% for the US treatment with MLM compared with the US-only treatment. Additionally, adsorption affected the performance during the US treatment in the presence of the catalyst. Thus, the US treatment in the presence of Ti3C2TX MXene had an enhanced performance not only because of increased oxidation but also because of adsorption, particularly between positively charged VRP and negatively charged Ti3C2TX MXene. Moreover, although the degradation of the performance was higher for SLM (85.1%) than for MLM (81.8%), by improving the dispersion and reducing the size via sonication, the US treatment in the presence of MLM showed the highest synergy effect. In other words, the US treatment in the presence of MLM showed higher performance than the simple sum of oxidation and adsorption. These findings confirm that the US treatment in the presence of MLM may be a promising technology to treat various pharmaceuticals as a more degradable, strongly reusable, and less toxic process.

Optimal cleaning strategy to alleviate fouling in membrane distillation process to treat anaerobic digestate.

This paper deals with the membrane fouling issue in the Direct Contact Membrane Distillation (DCMD) process treating a wasted sludge from an anaerobic digestion process. The main objective is to define an optimal cleaning strategy to alleviate fouling. Using a lab scale DCMD process, a cleaning strategy based on DI water flushing followed by 0.2% sodium hypochlorite (NaOCl) and 3% citric acid (C6H8O7) cleaning was tested with different cleaning frequencies and various chemical cleaning durations at different cross-flow velocities. To avoid severe fouling, the optimal cross-flow velocity was found at 0.18 m/s (0.8 L/min). Moreover, even if higher cross-flow velocity allows higher flux, it could increase fouling risks. For a better membrane regeneration and process productivity, a cleaning of 60 min duration for each chemical cleaning applied every two days was defined as the optimal cleaning strategy. Such conditions allowed the preservation of 75.5% of the initial flux after 96 h of operation. Furthermore, the effect on membrane flux regeneration of DI water flushing, sodium hypochlorite, and citric acid cleaning registered were, 31.52%, 11.95% and 20.65%, respectively. This study revealed that in the MD process treating real wastewater both external and internal fouling are responsible of permeate flux decline due to the accumulation of organic and inorganic matter on the membrane surface as well as within the pores.

Review of MXene-based nanocomposites for photocatalysis.

Since multilayered MXenes (Ti3C2Tx, a new family of two-dimensional materials) were initially introduced by researchers at Drexel University in 2011, various MXene-based nanocomposites have received increased attention as photocatalysts owing to their exceptional properties (e.g., rich surface chemistry, adjustable bandgap structures, high electrical conductivity, hydrophilicity, thermal stability, and large specific surface area). Therefore, we present a comprehensive review of recent studies on fabrication methods for MXene-based photocatalysts and photocatalytic performance for contaminant degradation, CO2 reduction, H2 evolution, and N2 fixation with various MXene-based nanocomposites. In addition, this review briefly discusses the stability of MXene-based nanophotocatalysts, current limitations, and future research needs, along with the various corresponding challenges, in an effort to reveal the unique properties of MXene-based nanocomposites.

Ultrasound-assisted Ti3C2Tx MXene adsorption of dyes: Removal performance and mechanism analyses via dynamic light scattering.

Herein, ultrasonication (US)-assisted novel nanomaterial Ti3C2Tx MXene was utilized as a selective adsorbent for treatment of synthetic dyes in model wastewater. Two types of US frequencies, 28 and 580 kHz, were applied to disperse MXene to evaluate the feasibility of US-assisted MXene for wastewater treatment. The physico-chemical properties of MXene after US were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential. According to FTIR and XPS, 28 kHz US-assisted MXene had a greater amount of oxygenated functional groups and dispersion compared to 580 kHz US-assisted and pristine MXene. Subsequently, US-assisted MXene was utilized as an adsorbent for the removal of positively charged methylene blue (MB) and negatively charged methyl orange. Both 28 and 580 kHz US-assisted MXene showed better adsorption performance for only MB compared to stirring-assisted MXene based on kinetics, isotherms, and several water chemistry factors including solution pH, temperature, ionic strength, and humic acid. Advantages of US-assisted MXene for water treatment are its fast kinetics at low dose and high selectivity for positively charged target compounds (i.e., MB). The main adsorption mechanism between MXene and MB was electrostatic interaction (attraction); however, physical properties (i.e., aggregation kinetics and hydrodynamic diameter), measured via dynamic light scattering, were also found to be critical factors in controlling the adsorption performance of the system. Lastly, US-assisted MXene exhibited a high regeneration property, based on 4th adsorption-desorption cycles.

A review on MXene-based nanomaterials as adsorbents in aqueous solution.

Environmental pollution has intensified and accelerated due to a steady increase in the number of industries, and finding methods to remove hazardous contaminants, which can be typically divided into inorganic and organic compounds, have become inevitable. One of the widely used water treatment technologies is adsorption and various kinds of adsorbents for the removal of inorganic and organic contaminants from water have been discovered. Recently, MXene, as an emerging nanomaterial, has gained rapid attention owing to its unique characteristics and various applicability. Particularly, in the area of adsorptive application, MXene and MXene-based adsorbents have shown great potential in a large number of studies. In this regard, a comprehensive understanding of the adsorptive behavior of MXene-based nanomaterials is necessary in order to explain how they remove inorganic and organic contaminants in water. Adsorption by MXene-based adsorbents tends to be highly influenced by not only the physicochemical properties of these adsorbents but also water quality, such as pH value, temperature, background ion, and natural organic matter. Therefore, in this review paper, the effect of various water quality on the adsorption of inorganic and organic contaminants by various types of MXene and MXene-based adsorbents is explored. Furthermore, this review also covers general trends in the synthesis of MXene and regeneration of MXene-based adsorbents in order to assess their stability.

The Distinct Role of Tcfs and Lef1 in the Self-Renewal or Differentiation of Mouse Embryonic Stem Cells.

BACKGROUND AND OBJECTIVES: Tcfs and Lef1 are DNA-binding transcriptional factors in the canonical Wnt signaling pathway. In the absence of ß-catenin, Tcfs and Lef1 generally act as transcriptional repressors with co-repressor proteins such as Groucho, CtBP, and HIC-5. However, Tcfs and Lef1 turn into transcriptional activators during the interaction with ß-catenin. Therefore, the activity of Tcfs and Lef1 is regulated by ß-catenin. However, the intrinsic role of Tcfs and Lef1 has yet to be examined. The purpose of this study was to determine whether Tcfs and Lef1 play differential roles in the regulation of self-renewal and differentiation of mouse ES cells. METHODS AND RESULTS: Interestingly, the expression of Tcfs and Lef1 was dynamically altered under various differentiation conditions, such as removal of LIF, EB formation and neuronal differentiation in N2B27 media, suggesting that the function of each Tcf and Lef1 may vary in ES cells. Ectopic expression of Tcf1 or the dominant negative form of Lef1 (Lef1-DN) contributes to ES cells to self-renew in the absence of leukemia inhibitory factor (LIF), whereas ectopic expression of Tcf3, Lef1 or Tcf1-DN did not support ES cells to self-renew. Ectopic expression of either Lef1 or Lef1-DN blocked neuronal differentiation, suggesting that the transient induction of Lef1 was necessary for the initiation and progress of differentiation. ChIP analysis shows that Tcf1 bound to Nanog promoter and ectopic expression of Tcf1 enhanced the transcription of Nanog. CONCLUSIONS: The overall data suggest that Tcf1 plays a critical role in the maintenance of stemness whereas Lef1 is involved in the initiation of differentiation.

Fouling and Retention Mechanisms of Selected Cationic and Anionic Dyes in a Ti3C2Tx MXene-Ultrafiltration Hybrid System.

Ti3C2Tx MXenes, a very new family of nanostructured material, were applied in combination with an ultrafiltration (UF) membrane (MXene-UF) for removal of the selected dyes including methylene blue (MB) and methyl orange (MO) as the first attempt. The normalized flux of the MXene-UF (0.90 for MB and 0.92 for MO) indicated better performance than a single UF (0.86 for MB and 0.90 for MO) and a powdered activated carbon (PAC)-UF (0.72 for MB and 0.75 for MO) for both dyes. The addition of an adsorbent decreased the irreversible fouling of the hybrid system compared to single UF, due to adsorption of dyes. The observed dominant fouling mechanism was cake layer fouling, evaluated using a resistance-in-series model, permeate flux modeling, and four conceptual blocking law models. PAC in particular acted as a foulant, leading to a severe flux decline. The average retention rate was found to be on the order of PAC-UF (57.7 and 47.9%) > MXene-UF (51.7 and 34.9%) > single UF (45.0 and 34.7%) for MB and MO, respectively. The results showed that although PAC exhibits relatively strong adsorption performance, MXene-UF also exhibited high selectivity due to electrostatic interaction between the MXene and dyes. In addition, humic acid (HA) adsorption on the membrane led to a reduction in the effective membrane area, resulting in a higher retention and lower flux for MXene-UF in the presence of HA. Furthermore, higher retention was observed for MXene-UF at pH 10.5 compared to pH 3.5 and 7, because MXene has more negative terminations at higher pH, leading to greater MB adsorption. Additionally, because of the bridging effect between the membrane and the MXene and competition between MB and cation ions for adsorption on the MXene, lower retention and flux were observed in MXene-UF with background ions.

Heterogeneous sonocatalytic degradation of an anionic dye in aqueous solution using a magnetic lanthanum dioxide carbonate-doped zinc ferrite-reduced graphene oxide nanostructure.

We report herein the sonochemical synthesis of a lanthanum dioxide carbonate (La2O2CO3) and zinc ferrite (ZnFe2O4)-loaded reduced graphene oxide (LZF-rGO) nanoheterostructure for ultrasound (US)-assisted degradation of methyl orange (MO) from water. The MO was chosen as a model organic dye due to its toxicological and biodegradable-resistant properties. The LZF-rGO catalyst was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results of characterizations confirmed successful synthesis of sonocatalyst. Among different removal systems, US/LZF-rGO displayed outstanding sonodegradation performance for degradation of MO. The maximum removal efficiency of 75.9% was achieved using 0.2 g/L sonocatalyst, 20 mg/L MO, and 0.71 W/cm2 US power intensity for 65 min. MO can be partially adsorbed on LZF-rGO but mostly sonodegraded by reactive radical species. The reaction conditions were optimized by investigating the effect of key operating parameters, including the sonocatalyst dosage, initial MO concentration, US power intensity, presence of inorganic salts, and use of an enhancer, on the decolorization of MO. The degradation intermediates produced from MO during the sonocatalytic process were identified by UPLC®/MS-MS, and possible mechanism and pathway for the degradation of MO in the US/LZF-rGO system were also proposed. Reusability experiments with this sonocatalyst revealed a less than 10% drop in the degradation efficiency after four adsorption-desorption cycles.

Enhanced sonocatalytic degradation of carbamazepine and salicylic acid using a metal-organic framework.

A metal-organic framework (MOF) was used as a sonocatalyst for ultrasonic (US) processes, to improve the degradation of two selected pharmaceutical active compounds (PhACs); carbamazepine (CBM) and salicylic acid (SA). The intrinsic characteristics of the MOF were characterized using a porosimeter (N2-BET) and scanning electron microscope (SEM). Various experiments were carried out under conditions with different US frequencies (28 and 1000 kHz), US power densities (45-180 W L-1), pH conditions (3.5, 7, and 10.5), and temperatures (293, 303, and 313 K) to investigate the degradation rates of the selected PhACs. Improved removal rates of PhACs were demonstrated within 60 min at 28 kHz (46% for SA; 47% for CBM) and 1000 kHz (60% for SA; 99% for CBM) with an MOF concentration of 45 mg L-1 in the US/MOF system, in comparison to 28 kHz (20% for SA; 25% for CBM) and 1000 kHz (37% for SA; 97% for CBM) under the 'US only' process. The removal of CBM was greater than that of SA under all experimental conditions due to the intrinsic properties of the PhACs. The degradation rates of PhACs are related to the quantity of H2O2; degradation is thus mostly affected by OH oxidation, which is generated by the dissociation of water molecules. The advantages of the 'US/MOF system' are as follows: (i) dispersion of MOF by US can improve sites and reactivity with respect to adsorption between the adsorbate (PhACs) and the adsorbent (MOF), and (ii) dispersed MOF acted as additional nuclei for water molecule pyrolysis, leading to the production of more OH. Therefore, based on the synergy indices, which were calculated using the removal rate constants [k1 (min-1)] of the pseudo-first order kinetic model, the 'US/MOF system' can potentially be used to treat organic pollutants (e.g., PhACs).

Comprehensive evaluation on removal of lead by graphene oxide and metal organic framework.

Graphene oxide (GO) and metal-organic framework (MOF) as adsorbents were applied to removal of Pb(II) with comprehensive characterizations and various experimental conditions. Various characterizations were conducted to clarify the physico-chemical properties of adsorbents. The analyses of adsorption experiments included (i) dosage amounts, (ii) isotherm and kinetic studies, and (iii) several factors related to water chemistry (i.e., solution pH, background ions, and humic acid). The maximum equilibrium adsorption capacity (qe) for Pb(II) using the GO and MOF was 555 and 108 mg g-1, respectively, as determined in the optimum dosage experiments. Although the surface area of the MOF (629 m2 g-1) was much larger than that of the GO (19.8 m2 g-1), the adsorption capacity of the MOF was five times lower due to electrical repulsion. Thus, the MOF was utilized as the control group for comparison with the GO to evaluate the adsorption mechanisms in the experiments related to surface charge (i.e., under various pH and humic acid conditions). The adsorption isotherms and kinetics model determined using GO followed the Langmuir model (R2 > 0.99) and pseudo-second-order model (R2 > 0.99), respectively. Additionally, three adsorption-desorption cycles were conducted with the GO adsorbent to evaluate the maintenance of the removal ratio after regeneration and the equilibrium adsorption capacity was determined. Finally, the adsorption of other heavy metals (i.e., Cu(II), Cd(II), and Zn(II)), separately and in mixtures, was also evaluated to determine the selectivity of the adsorbents.

Mutation Hotspots in the ß-Catenin Gene: Lessons from the Human Cancer Genome Databases.

Mutations in the ß-catenin gene (CTNNB1) have been implicated in the pathogenesis of some cancers. The recent development of cancer genome databases has facilitated comprehensive and focused analyses on the mutation status of cancer-related genes. We have used these databases to analyze the CTNNB1 mutations assembled from different tumor types. High incidences of CTNNB1 mutations were detected in endometrial, liver, and colorectal cancers. This finding agrees with the oncogenic role of aberrantly activated ß-catenin in epithelial cells. Elevated frequencies of missense mutations were found in the exon 3 of CTNNB1, which is responsible for encoding the regulatory amino acids at the N-terminal region of the protein. In the case of metastatic colorectal cancers, inframe deletions were revealed in the region spanning exon 3. Thus, exon 3 of CTNNB1 can be considered to be a mutation hotspot in these cancers. Since the N-terminal region of the ß-catenin protein forms a flexible structure, many questions arise regarding the structural and functional impacts of hotspot mutations. Clinical identification of hotspot mutations could provide the mechanistic basis for an oncogenic role of mutant ß-catenin proteins in cancer cells. Furthermore, a systematic understanding of tumor-driving hotspot mutations could open new avenues for precision oncology.

Aqueous removal of inorganic and organic contaminants by graphene-based nanoadsorbents: A review.

Various graphene-based nanoadsorbents, including graphenes, graphene oxides, reduced graphene oxides, and their nanocomposites, have been widely studied as potential adsorbents due to their unique physicochemical properties, such as structural variability, chemical strength, low density, and the possibility of large scale fabrication. Adsorption mechanisms are governed largely by the physicochemical properties of contaminants, the characteristics of nanoadsorbents, and background water quality conditions. This review summarizes recent comprehensive studies on the removal of various inorganic (mainly heavy metals) and organic contaminants by graphene-based nanoadsorbents, and also discusses valuable information for applications of these nanoadsorbents in water and wastewater treatment. In particular, the aqueous removal of various contaminants was reviewed to (i) summarize the general adsorption capacities of various graphene-based nanoadsorbents for the removal of different inorganic and organic contaminants, (ii) evaluate the effects of key water quality parameters such as pH, temperature, background major ions/ionic strength, and natural organic matter on adsorption, (iii) provide a comprehensive discussion of the mechanisms that influence adsorption on these nanoadsorbents, and (iv) discuss the potential regeneration and reusability of nanoadsorbents. In addition, current challenges and future research needs for the removal of contaminants by graphene-based nanoadsorbents in water treatment processes are discussed briefly.