查找使用阿拉丁产品的科研文献

Biosorption, an efficient method for removing heavy metals from industrial effluents: A Review

Ali Aghababai Beni,Akbar Esmaeili

Common methods for removing heavy metals have numerous drawbacks, including low efficiency and high costs. In the biosorption of heavy metals, ions biosorbed on surfaces and active sites of biosorbents. In this paper, the relationship between the factors (pH, temperature, biosorbent dosage, retention time and Functional groups) and removal efficiency has been investigated. The purpose of this work is to introduce optimal conditions for biosorption reaction. Also, by introducing various types of biosorbents, expressed the advantages and method of preparation for each one. In various papers, not all biosorption isotherm models have been mentioned, there are described various types of biosorption isotherm, kinetics and thermodynamics models and important process data is set up for quick access to the tables.

Amino acid-modulating gold nanoparticle sensor array: an express metal ion recognition system

Zhengfan Shui,Jiawei Li,Ping Yang,Danqun Huo,Changjun Hou,Caihong Shen

Metal ions (MIs) are necessary for biological growth and development, but they may also harm the health of organisms. The quantitative detection and classification of MIs are of great significance. In this study, we report a novel, fast, simple and high throughput colorimetric sensor array for MI discrimination. By employing the soft and weak chemical bond ability of key formula, we successfully increased the array sensitivity by reducing cross-response specificity to achieve high-throughput detection at low-concentration. Pattern recognition shows the outstanding discrimination ability of the developed array for 18 MIs at 10 μM. In addition, the Euclidean distance of ΔRGB values (the change in value of red, green and blue signal channel in the RGB color model) exhibits a positive linear correlation, which is demonstrated by model ions (Cu2+). Moreover, the cross validation accuracy for the discrimination of 18 MIs in human plasma was found to be 88.9%, which indicates great potential in practical detection using our array.

Epsilon-negative behavior of BaTiO3/Ag metacomposites prepared by an in situ synthesis

Zhongyang Wang,Peitao Xie,Guohua Fan,Zidong Zhang,Yao Liu,Qilin Gu,Runhua Fan

Epsilon-negative behavior in metamaterials has attracted increasing attention recently. In this work, excessively percolating BaTiO 3 /Ag composites were synthesized by an in-situ preparation method to achieve negative permittivity. The epsilon-negative behavior is explained by low-frequency plasma oscillation of free electrons, which can be well fitted by the Drude model. Moreover, the negative permittivity of composites can be tuned by adjusting the content of randomly distributed Ag particles. The ac conductivity of excessively percolating BaTiO 3 /Ag composites shows a typical metal-like behavior. Furthermore, the investigation of reactance reveals that the inductive character derived from the conductive network is the main contributor to negative permittivity, as confirmed by the equivalent circuit analysis. This work provides a theoretical recipe for designing negative permittivity, supplements the family of metamaterials, and would further facilitate the practical applications of epsilon-negative materials in electromagnetic devices.

Hydrophobically Modified Glucan as an Amphiphilic Carbohydrate Polymer for Micellar Delivery of Myricetin

Weiyu Yang,Ling Guo,Fenfen Li,Xin Liu,Shaoping Nie,Mingyong Xie,Danfei Huang

Myricetin (Myr) is a phytochemical with many functional properties. However, its hydrophobicity, low bioavailability, and stability limit its application. In this study, octadecanoate oat β-glucan (OGE) was synthesized and gained recognition as a self-assembled micelle forming a polymer with a critical micelle concentration (CMC) of 59.4 μg/mL. The Myr-loaded OGE micelle was then prepared and characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), X-ray diffractometer (XRD), and Fourier-transform infrared spectroscopy (FT-IR) spectra. The water solubility of Myr was greatly enhanced by forming the Myr/OGE inclusion complex. Consequently, compared to free Myr, the retention of Myr in Myr-loaded OGE micelle was effectively increased during the intestinal digestion phase, and its antioxidant activity was also improved. Overall, our findings demonstrated the potential applications of OGE polymer for the development of prospective micelle in health food, cosmetics, and pharmaceutical fields because they can aid in the delivery of hydrophobic functional compounds like Myr.Keywords:phytochemicals;myricetin;amphiphilicity;micelle;self-assembly

An ultralight, supercompressible, superhydrophobic and multifunctional carbon aerogel with a specially designed structure

Sishi Long,Yunchao Feng,Faliang He,Shuaishuai He,Huachi Hong,Xuerui Yang,Lingling Zheng,Jian Liu,Lihui Gan,Minnan Long

Compressible and ultralight carbon aerogels are attractive due to its compressibility , elasticity and conductivity. However, it is still a great challenge to enrich the properties of carbon aerogel to meet various requirements. Herein, we report an untralight, supercompressible, fatigue resistant, superhydrophobic and fire-resistant and multifunctional CNF-GO/glucose-kaolin carbon aerogel (C-NGGK) carbon aerogel. To achieve such excellent performances, calcined GO , CNFs , glucose and kaolin are used for forming low-density and continuous wave-shape rGO layers, reinforcing the mechanical strength of carbon layers , realizing superelasticity and fatigue resistance and resulting in a superhydrophobic surface for C-NGGK, respectively. The as-prepared C-NGGK demonstrates excellent superhydrophobicity with the water contact angle (WCA) of 124.9°, and the absorption efficiency of the C-NGGK samples for different oils and organic solvents are 75–255 times their own weight. These advantages show that the C-NGGK can be an ideal candidate for oil/water separation. In addition, there is also the prospect to be used for pressure sensors , while other potential applications include three-dimensional electrode materials for supercapacitors and batteries , catalyst carriers and various wearable devices .

Highly efficient and selective recovery of gallium achieved on an amide-functionalized cellulose

Wanghuan Guo,Jinbo Zhang,Fan Yang,Fengzhi Tan,Zhigang Zhao

Pattern-based recognition of proteins by an array of fluorescent carbon-nanodot receptors

Yulin Liu,Shun Hu,Guoli Zhang,Qiuhua Wu,Guolin Zhang,Xue Liu

Protein types and concentrations in human body fluid environment have a direct correlation to health conditions, and can be used for primary screening and diagnostics of a great variety of diseases. Herein, we synthesized a series of fluorescent carbon nanodots (CDs) with various ratios of β-cyclodextrin doping, which can recognize proteins and adjust self-emission by combining both the cavity recognition effect of cyclodextrin and noncovalent bonding effect of carboxyl, amino and hydroxyl groups . The difference in β-cyclodextrin contents of various CDs will result in a differential response to various proteins, based on which a sensor array by four CDs was constructed to detect and discriminate six proteins with various subunit numbers. In order to improve the discriminative effect of the sensor array, CD-sensitive metal ions (Cu 2+ and Fe 3+ ) were introduced as sensing media to increase the action sites between the CDs and proteins, and these proteins were well discriminated by the [email protected] ion sensor array with a detection limit of 50 μM. The sensor array could work in physiological conditions (such as urine and serum) and realize multiple proteins detection. Combining with the good repeatable detection results and higher sensitivity, the sensor array based on the CDs and metal ions provides an efficient and accurate method to detect proteins, which is important for disease diagnosis through assessing protein levels.

Molecular switch manipulating Prelog priority of an alcohol dehydrogenase toward bulky-bulky ketones

Guochao Xu,Wei Dai,Yue Wang,Lu Zhang,Zewen Sun,Jieyu Zhou,Ye Ni

Structure-guided rational design revealed the molecular switch manipulating the Prelog and anti-Prelog priorities of an NADPH-dependent alcohol dehydrogenase toward prochiral ketones with bulky and similar substituents. Synergistic effects of unconserved residues at 214 and 237 in small and large substrate binding pockets were proven to be vital in governing the stereoselectivity. The ee values of E214Y/S237A and E214C/S237 G toward (4-chlorophenyl)-(pyridin-2-yl)-methanone were 99.3% ( R ) and 78.8% ( S ) respectively. Substrate specificity analysis revealed that similar patterns were also found with (4’-chlorophenyl)-phenylmethanone, (4’-bromophenyl)-phenylmethanone and (4’-nitrophenyl)-phenylmethanone. This study provides valuable evidence for understanding the molecular mechanism on enantioselective recognition of prochiral ketones by alcohol dehydrogenase.

Facile loading carbon dots on Co3O4 as an enhanced oxygen reduction reaction catalyst

Xiaoyan Zhang,Xiumei Cheng,Feng Chen,Li Xu,Yaping Wang,Junchao Qian,Zhengying Wu,Qi Zhang

One of the crucial issues in fuel cells is to explore the highly-efficient, long-term stable and low-cost catalysts for the oxygen reduction reaction (ORR). Here, the carbon dots/Co 3 O 4 (CDs/Co 3 O 4 ) is reported as an effective electrocatalyst for ORR. The CDs/Co 3 O 4 was synthesized through an in-situ two-step heating strategy with the graphitic carbon nitride (g-C 3 N 4 ), cobalt nitrate hexahydrate and organic base as raw materials. The carbon dots (CDs) are derived from the C source of g-C 3 N 4 , which are in situ introduced into the Co 3 O 4 to form the CDs/Co 3 O 4 composite. Consequently, the introduction of CDs endows enhanced electrocatalytic activity of the CDs/Co 3 O 4 composite.

An Ammonium-Formate-Driven Trienzymatic Cascade for ω-Transaminase-Catalyzed (R)-Selective Amination

Fei-Fei Chen,Yu-Hui Zhang,Zhi-Jun Zhang,Lei Liu,Jian-Ping Wu,Jian-He Xu,Gao-Wei Zheng

(R)-Amination mediated by (R)-specific ω-transaminases generally requires costly d-alanine in excess to obtain the desired chiral amines in high yield. Herein, a one-pot, trienzymatic cascade comprising an (R)-specific ω-transaminase, an amine dehydrogenase, and a formate dehydrogenase was developed for the economical and eco-friendly synthesis of (R)-chiral amines. Using inexpensive ammonium formate as the sole sacrificial agent, the established cascade system enabled efficient ω-transaminase-mediated (R)-amination of various ketones, with high conversions and excellent ee (>99%); water and CO2 were the only waste products.

Stable, Bioresponsive, and Macrophage-Evading Polyurethane Micelles Containing an Anionic Tripeptide Chain Extender

Danxuan Fang,Menghan Pi,Zhicheng Pan,Nijia Song,Xueling He,Jiehua Li,Feng Luo,Hong Tan,Zhen Li

Polymeric nanocarriers have been extensively used in medicinal applications for drug delivery. However, intravenous nanocarriers circulating in the blood will be rapidly cleared from the mononuclear macrophage system. The surface physicochemical characterizations of nanocarriers are the primary factors to determine their fate in vivo, such as evading the reticuloendothelial system, exhibiting long blood circulation times, and accumulating in the targeted site. In this work, we develop a series of polyurethane micelles containing segments of an anionic tripeptide, hydrophilic mPEG, and disulfide bonds. It is found that the long hydrophilic mPEG can shield the micellar surface and have a synergistic effect with the negatively charged tripeptide to minimize macrophage phagocytosis. Meanwhile, the disulfide bond can rapidly respond to the intracellular reduction environment, leading to the acceleration of drug release and improvement of the therapeutic effect. Our results verify that these anionic polyurethane micelles hold great potential in the development of the stealth immune system and controllable intracellular drug transporters.

Activated Carbon Aerogel as an Electrode with High Specific Capacitance for Capacitive Deionization

Wei Wang,Kerui Li,Ge Song,Minghua Zhou,Peng Tan

In this study, carbon aerogels (CAs) were synthesized by the sol-gel method, using environmentally friendly glucose as a precursor, and then they were further activated with potassium hydroxide (KOH) to obtain activated carbon aerogels (ACAs). After the activation, the electrochemical performance of the ACAs was significantly improved, and the specific capacitance increased from 19.70 F·g−1to 111.89 F·g−1. Moreover, the ACAs showed a stronger hydrophilicity with the contact angle of 118.54° compared with CAs (69.31°). When used as an electrode for capacitive deionization (CDI), the ACAs had not only a better diffuse electric double layer behavior, but also a lower charge transfer resistance and intrinsic resistance. Thus, the ACA electrode had a faster CDI desalination rate and a higher desalination capacity. The unit adsorption capacity is three times larger than that of the CA electrode. In the desalination experiment of 100 mg·L−1sodium chloride (NaCl) solution using a CDI device based on the ACA electrode, the optimal electrode spacing was 2 mm, the voltage was 1.4 V, and the flow rate was 30 mL·min−1. When the NaCl concentration was 500 mg·L−1, the unit adsorption capacity of the ACA electrode reached 26.12 mg·g−1, much higher than that which has been reported in many literatures. The desalination process followed the Langmuir model, and the electro-sorption of the NaCl was a single layer adsorption process. In addition, the ACA electrode exhibited a good regeneration performance and cycle stability.Keywords:carbon aerogel;activation;capacitive deionization;desalination;electro-sorption