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Spectrokinetics study of probable effects of diverse inorganic ions on bleaching of dye

Rafia AZMAT, Masooda QADRI, Fahim UDDIN

《化学科学与工程前沿(英文)》 2011年 第5卷 第1期   页码 131-138 doi: 10.1007/s11705-010-0556-z

摘要: Toluidine blue (TB) is an important anticoagulant metachromasia molecule showing a pronounced variation in the visible spectrum due to the aggregation phenomenon and electrostatic interaction with the charged synthetic and biologic polymers. The current study describes the interactive role of diverse inorganic material ions on the bleaching of toluidine blue (tolonium chloride) (TB ) with urea in acidic and basic media using the spectrophotometric technique. The spectra of TB and urea with different cations and anions were monitored and their characteristic features are presented here. The negative effect of added cations on reduction may be the result of altered electron pathways which led to suppression of the reduction/bleaching of TB, while a slight decrease in dye reduction by added anions may be due to the scavenging of the OH* radical. It has been observed in the case of Co that in addition to the electron-transfer reaction, other processes like layer and precipitate formation also appear to be taking place. The dye bleaching process followed pseudo first order kinetics with respect to TB, urea, and H ion, whereas significant decoloration in the presence of urea proved that reductants control the redox reaction. No decoloration in acidic medium with diverse ions was seen compared to alkaline media, showing that water pH played an important role in the bleaching of dye. The reduction/bleaching of dye was investigated at different temperatures, and energy parameters were evaluated for a TB -Urea reaction, including the energy of activation ( = 39.60 kJ·mol ), enthalpy of activation (? = 34?kJ·mol ), entropy of activation (? = 146.5 kJ mol ·K ), and free energy of activation (ΔG* = -52.35 kJ·mol ). A mechanism of interaction of diverse ions in dye bleaching and a mechanism of reduction based on the above findings is proposed.

关键词: TB     diverse ions     suppress     decoloration    

Rhamnolipid synthesis and production with diverse resources

Qingxin Li

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 27-36 doi: 10.1007/s11705-016-1607-x

摘要: Rhamnolipids are one of the most effective biosurfactants that are of great interest in industrial applications such as enhancing oil recovery, health care, cosmetics, pharmaceutical processes, food processing, detergents for protein folding, and bioremediation due to their unique characteristics such as low toxicity, surface active property to reduce surface/interfacial tensions, and excellent biodegradability. The genes and metabolic pathways for rhamnolipid synthesis have been well elucidated, but its cost-effective production is still challenging. , the most powerful rhamnolipid producer, is an opportunistic pathogen, which limits its large scale production and applications. Rhamnolipid production using engineered strains other than such as and has received much attention. The highest yield of rhamnolipids is achieved when oil-type carbon sources are used, but using cheaper and renewable carbon sources such as lignocellulose would be an attractive strategy to reduce the production cost of rhamnolipids for various industrial applications.

关键词: biosurfactant     rhamnolipid     Pseudomonas     waste     surface tension    

Molecular pathogenesis of acute myeloid leukemia: A diverse disease with new perspectives

Felicitas THOL, Arnold GANSER

《医学前沿(英文)》 2010年 第4卷 第4期   页码 356-362 doi: 10.1007/s11684-010-0220-5

摘要: Acute myeloid leukemia (AML) is a very heterogeneous neoplasm of the hematopoietic stem cell. Despite important achievements in the treatment of AML, the long term survival of patients with the disease remains poor. Understanding the pathogenesis of AML better is crucial for finding new treatment approaches. During AML development hematopoietic precursor cells undergo clonal transformation in a multistep process through acquisition of chromosomal rearrangements and/or different gene mutations. Over recent years, novel gene mutations have been found in patients with AML. These mutations can be divided into two important categories, class I mutations that confer a proliferation advantage and class II mutations that inhibit myeloid differentiation. Screening for some of these mutations is now part of the initial diagnostic work-up in newly diagnosed AML patients. Information about the mutation status of specific genes is useful for risk-stratification, minimal residual disease (MRD) monitoring and increasingly also for targeted therapy, especially for patients with cytogenetically normal AML (CN-AML). Besides chromosomal rearrangements and gene mutations, epigenetic regulation of genes – meaning changes in gene expression by mechanisms other than changes in the underlying DNA sequence – also represents an important mechanism of leukemogenesis. This article reviews some of the most common mutations in CN-AML and gives a perspective of the translation of these discoveries from bench to bedside.

关键词: acute myeloid leukemia     mutations     risk stratification    

REGIONAL ASSESSMENT OF SOIL NITROGEN MINERALIZATION IN DIVERSE CROPLAND OF A REPRESENTATIVE INTENSIVE

《农业科学与工程前沿(英文)》 2023年 第10卷 第4期   页码 530-540 doi: 10.15302/J-FASE-2023515

摘要:

Soil nitrogen mineralization (Nmin) is a key process that converts organic N into mineral N that controls soil N availability to plants. However, regional assessments of soil Nmin in cropland and its affecting factors are lacking, especially in relation to variation in elevation. In this study, a 4-week incubation experiment was implemented to measure net soil Nmin rate, gross nitrification (Nit) rate and corresponding soil abiotic properties in five field soils (A–C, maize; D, flue-cured tobacco; and E, vegetables; with elevation decreasing from A to E) from different altitudes in a typical intensive agricultural area in Dali City, Yunnan Province, China. The results showed that soil Nmin rate ranged from 0.10 to 0.17 mg·kg−1·d−1 N, with the highest value observed in field E, followed by fields D, C, B, and A, which indicated that soil Nmin and Nit rates varied between fields, decreasing with elevation. The soil Nit rate ranged from 434.2 to 827.1 µg·kg−1·h−1 N, with the highest value determined in field D, followed by those in fields E, C, B, and A. The rates of soil Nmin and Nit were positively correlated with several key soil parameters, including total soil N, dissolved organic carbon and dissolved inorganic N across all fields, which indicated that soil variables regulated soil Nmin and Nit in cropland fields. In addition, a strong positive relationship was observed between soil Nmin and Nit. These findings provide a greater understanding of the response of soil Nmin among cropland fields related to spatial variation. It is suggested that the soil Nmin from cropland should be considered in the evaluation of the N transformations at the regional scale.

关键词: cropland     gross nitrification rate     regulatory factors     soil nitrogen mineralization     spatial variation    

minimized fluorescent chemosensor array utilizing carboxylate-attached polythiophenes on a chip for metal ions

Yui Sasaki, Xiaojun Lyu, Zhoujie Zhang, Tsuyoshi Minami

《化学科学与工程前沿(英文)》 2022年 第16卷 第1期   页码 72-80 doi: 10.1007/s11705-021-2037-y

摘要: Chemosensor arrays have a great potential for on-site applications in real-world scenarios. However, to fabricate on chemosensor array a number of chemosensors are required to obtain various optical patterns for multi-analyte detection. Herein, we propose a minimized chemosensor array composed of only two types of carboxylate-functionalized polythiophene derivatives for the detection of eight types of metal ions. Upon recognition of the metal ions, the polythiophenes exhibited changes in their fluorescence intensity and various spectral shifts. Although both chemosensors have the same polymer backbone and recognition moiety, only the difference in the number of methylene groups contributed to the difference in the fluorescence response patterns. Consequently, the metal ions in aqueous media were successfully discriminated qualitatively and quantitatively by the chemosensor microarray on the glass chip. This study offers an approach for achieving a minimized chemosensor array just by changing the alkyl chain lengths without the necessity for many receptors and reporters.

关键词: metal ions     polythiophene     chemosensor array     fluorescence     pattern recognition    

Nano-copper ions assembled cellulose-based composite with antibacterial activity for biodegradable personal

《化学科学与工程前沿(英文)》 2023年 第17卷 第10期   页码 1544-1554 doi: 10.1007/s11705-022-2288-2

摘要: The current SARS-CoV-2 pandemic has resulted in the widespread use of personal protective equipment, particularly face masks. However, the use of commercial disposable face masks puts great pressure on the environment. In this study, nano-copper ions assembled cotton fabric used in face masks to impart antibacterial activity has been discussed. To produce the nanocomposite, the cotton fabric was modified by sodium chloroacetate after its mercerization, and assembled with bactericidal nano-copper ions (about 10.61 mg·g–1) through electrostatic adsorption. It demonstrated excellent antibacterial activity against Staphylococcus aureus and Escherichia coli because the gaps between fibers in the cotton fabric allow the nano-copper ions to be fully released. Moreover, the antibacterial efficiency was maintained even after 50 washing cycles. Furthermore, the face mask constructed with this novel nanocomposite upper layer exhibited a high particle filtration efficiency (96.08% ± 0.91%) without compromising the air permeability (28.9 min·L–1). This green, economical, facile, and scalable process of depositing nano-copper ions onto modified cotton fibric has great potential to reduce disease transmission, resource consumption, and environmental impact of waste, while also expanding the range of protective fabrics.

关键词: cellulose-based     nanocomposite     biodegradable antibacterial fabric     nano-copper ions     face masks    

Effects of metal ions on the morphology of calcium sulfate hemihydrate whiskers by hydrothermal method

Tianjie Liu, Hao Fan, Yanxia Xu, Xingfu Song, Jianguo Yu

《化学科学与工程前沿(英文)》 2017年 第11卷 第4期   页码 545-553 doi: 10.1007/s11705-017-1665-8

摘要: The effects of Na , Mg , Al and Fe ion concentrations on the crystal morphology of calcium sulfate hemihydrate whiskers formed via a hydrothermal method have been studied. In the presence of Al concentrations higher than 1×10 mol/L the whiskers were significantly shorter and thicker and the presence of Mg and Fe resulted in shorter whiskers. The presence of Na did not affect the morphology of the whiskers. Through elemental analysis, it was determined that Mg and Al were selectively adsorbed on the surfaces of the crystals, whereas Fe underwent a hydrolysis reaction to form a brown precipitate which decreased the ion concentration in the solution. These results indicate that in raw materials used for the industrial preparation of calcium sulfate whiskers, Al and Fe should be removed and the Mg concentration should be less than 8 × 10 mol/L in order to obtain pure whiskers with high aspect ratios.

关键词: metal ions     morphology     calcium sulfate hemihydrate whiskers     hydrothermal method     selective adsorption    

Removal of Ni(II) ions from wastewater by micellar enhanced ultrafiltration using mixed surfactants

Amar D. Vibhandik, Kumudini V. Marathe

《化学科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 79-86 doi: 10.1007/s11705-014-1407-0

摘要: Ni(II) ions were removed from aqueous waste using micellar enhanced ultrafiltration (MEUF) with a mixture of surfactants. The surfactant mixture was the nonionic surfactant Tween 80 (TW80) mixed with the anionic surfactant sodium dodecyl sulfate (SDS) in different molar ratios ranging from 0.1–1.5. The operational variables of the MEUF process such as pH, applied pressure, surfactant to metal ion ratio and nonionic to ionic surfactant molar ratio (α) were evaluated. Rejection of Ni and TW80 was 99% and 98% respectively whereas that for SDS was 65%. The flux and all resistances (fouling resistance, resistance due to concentration polarization) were measured and calculated for entire range of α respectively. A calculated flux was found to be declined with time, which was mainly attributed to concentration polarization rather than resistance from membrane fouling.

关键词: MEUF     Ni (II) ions     membrane resistance     concentration polarization     mixed surfactants    

Simultaneous removal of total oxidizable carbon, phosphate and various metallic ions from HO solution

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 470-482 doi: 10.1007/s11705-022-2231-6

摘要: Amino-functionalized zirconia was synthesized by the co-condensation method using zirconium butanol and 3-aminopropyltriethoxy silane for the simultaneous removal of various impurities from aqueous 30% H2O2 solution. The results of Fourier transform infrared (FTIR) and Zeta potential showed that the content of N in amino-functionalized zirconia increased with the added amount of 3-aminopropyltriethoxy silane. Accordingly, the removal efficiency of total oxidizable carbon, phosphate and metallic ions from the H2O2 solution increased. The adsorbent with an N content of 1.62% exhibited superior adsorption performance. The removal efficiency of 82.7% for total oxidizable carbon, 34.2% for phosphate, 87.1% for Fe3+, 83.2% for Al3+, 55.1% for Ca2+ and 66.6% for Mg2+, with a total adsorption capacity of 119.6 mg·g–1, could be achieved. The studies conducted using simulated solutions showed that the adsorption process of phosphate on amino-functionalized zirconia is endothermic and spontaneous, and the behaviors could be well described by the pseudo-second-order model and Langmuir model with a maximum adsorption capacity of 186.7 mg·g–1. The characterizations of the spent adsorbents by Zeta potential, FTIR and X-ray photoelectron spectroscopy revealed that the adsorption mechanism of phosphate is predominantly electrostatic attraction by the protonated functional groups and complementary ligand exchange with zirconium hydroxyl groups.

关键词: adsorption     zirconia     total oxidizable carbon     phosphate     metallic ions     hydrogen peroxide    

Diverse bacterial populations of PM in urban and suburb Shanghai, China

《环境科学与工程前沿(英文)》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1329-7

摘要:

• Urban aerosols harbour diverse bacterial communities in Shanghai.

关键词: PM2.5     Bacteria     16S rRNA     SEM analysis     Shanghai City    

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 749-758 doi: 10.1007/s11705-022-2261-0

摘要: Since lithium iron phosphate cathode material does not contain high-value metals other than lithium, it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials. Here, we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield. Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions. Iron is retained in the leaching residue as iron phosphate, which is easy to recycle. The effects of factors such as acid concentration, acid dosage, amount of oxidant, and reaction temperature on the leaching of lithium and iron are comprehensively explored, and the mechanism of selective leaching is clarified. This process greatly reduces the cost of processing equipment and chemicals. This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.

关键词: lithium iron phosphate powder     stoichiometric number     selective leaching     lithium recovery    

Analysis of mobilization of inorganic ions in soil by electrokinetic remediation

Xiaojing LI, Lige WANG, Xueming SUN, Yuansheng CONG

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1463-1473 doi: 10.1007/s11709-019-0569-8

摘要: Saline soil has imposed a serious threat on many expressway engineering and agricultural areas. This paper describes the performance of saline soil treatment using electrokinetic remediation technology. Comparison study involving sample soil and soil is carried out. Two different electric fields, i.e., uniform and non-uniform are utilized to promote the migration of inorganic ions contained in the soil toward the electrode area. The effects of different electric field types and potential gradient ion migration rate in soil are investigated. The test result reveals that a uniform electric field of a constant potential gradient of 1 V/cm drives the Cl through the sample soil at a rate of 1.36 cm/h. Moreover, larger potential gradients could make ions migrate faster, but more electrical energy is consumed in such a way. Compared with uniform electric field, the non-uniform process maintains the soil pH values more effectively and consumes less electrical energy. A desirable result of removing Na in soil is expected using electrokinetic remediation technology under four-times scaling up of soil volume.

关键词: electromigration     electric fields     saline soil     soil-remediation    

A ternary mechanism for the facilitated transfer of metal ions onto metal–organic frameworks: implications

《化学科学与工程前沿(英文)》   页码 1632-1642 doi: 10.1007/s11705-022-2187-6

摘要: Although metal–organic frameworks offer a new platform for developing versatile sorption materials, yet coordinating the functionality, structure and component of these materials remains a great challenge. It depends on a comprehensive knowledge of a “real sorption mechanism”. Herein, a ternary mechanism for U(VI) uptake in metal–organic frameworks was reported. Analogous MIL-100s (Al, Fe, Cr) were prepared and studied for their ability to sequestrate U(VI) from aqueous solutions. As a result, MIL-100(Al) performed the best among the tested materials, and MIL-100(Cr) performed the worst. The nuclear magnetic resonance technique combined with energy-dispersive X-ray spectroscopy and zeta potential measurement reveal that U(VI) uptake in the three metal–organic frameworks involves different mechanisms. Specifically, hydrated uranyl ions form outer-sphere complexes in the surface of MIL-100s (Al, Fe) by exchanging with hydrogen ions of terminal hydroxyl groups (Al-OH2, Fe-OH2), and/or, hydrated uranyl ions are bound directly to Al(III) center in MIL-100(Al) through a strong inner-sphere coordination. For MIL-100(Cr), however, the U(VI) uptake is attributed to electrostatic attraction. Besides, the sorption mechanism is also pH and ionic strength dependent. The present study suggests that changing metal center of metal–organic frameworks and sorption conditions alters sorption mechanism, which helps to construct effective metal–organic frameworks-based sorbents for water purification.

关键词: U(VI)     metal–organic frameworks     adsorption mechanism     metal node    

Removal of Cu(II) ions from aqueous solution by activated carbon impregnated with humic acid

LIU Hanchao,FENG Suping,ZHANG Nannan,DU Xiaolin,LIU Yongli

《环境科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 329-336 doi: 10.1007/s11783-013-0553-9

摘要: Humic acid (HA) was impregnated onto powdered activated carbon to improve its Cu(II) adsorption capability. The optimum pH value for Cu(II) removal was 6. The maximum adsorption capacity of HA-impregnated activated carbon was up to 5.98 mg·g , which is five times the capacity of virgin activated carbon. The adsorption processes were rapid and accompanied by changes in pH. In using a linear method, it was determined that the equilibrium experimental data were better represented by the Langmuir isotherm than by the Freundlich isotherm. Surface charges and surface functional groups were studied through zeta potential and FTIR measurements to explain the mechanism behind the humic-acid modification that enhanced the Cu(II) adsorption capacity of activated carbon.

关键词: adsorption     humic acid     activated carbon     heavy metal ions    

Effects of natural zeolite and sulfate ions on the mechanical properties and microstructure of plastic

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 86-98 doi: 10.1007/s11709-021-0793-x

摘要: One of the strategic materials used in earth-fill embankment dams and in modifying and preventing groundwater flow is plastic concrete (PlC). PlC is comprised of aggregates, water, cement, and bentonite. Natural zeolite (NZ) is a relatively abundant mineral resource and in this research, the microstructure, unconfined strength, triaxial behavior, and permeability of PlC made with 0%, 10%, 15%, 20%, and 25% replacement of cement by NZ were studied. Specimens of PIC-NZ were subjected to confined conditions and three different confining pressures of 200, 350, and 500 kPa were used to investigate their mechanical behavior and permeability. To study the effect of sulfate ions on the properties of PlC-NZ specimens, the specimens were cured in one of two different environments: normal condition and in the presence of sulfate ions. Results showed that increasing the zeolite content decreases the unconfined strength, elastic modulus, and peak strength of PlC-NZ specimens at the early ages of curing. However, at the later ages, increasing the zeolite content increases unconfined strength as well as the peak strength and elastic modulus. Specimens cured in the presence of sulfate ions indicated lower permeability, higher unconfined strength, elastic modulus, and peak strength due to having lower porosity.

关键词: plastic concrete     sulfate resistance     natural zeolite     triaxial compression test     SEM     permeability    

标题 作者 时间 类型 操作

Spectrokinetics study of probable effects of diverse inorganic ions on bleaching of dye

Rafia AZMAT, Masooda QADRI, Fahim UDDIN

期刊论文

Rhamnolipid synthesis and production with diverse resources

Qingxin Li

期刊论文

Molecular pathogenesis of acute myeloid leukemia: A diverse disease with new perspectives

Felicitas THOL, Arnold GANSER

期刊论文

REGIONAL ASSESSMENT OF SOIL NITROGEN MINERALIZATION IN DIVERSE CROPLAND OF A REPRESENTATIVE INTENSIVE

期刊论文

minimized fluorescent chemosensor array utilizing carboxylate-attached polythiophenes on a chip for metal ions

Yui Sasaki, Xiaojun Lyu, Zhoujie Zhang, Tsuyoshi Minami

期刊论文

Nano-copper ions assembled cellulose-based composite with antibacterial activity for biodegradable personal

期刊论文

Effects of metal ions on the morphology of calcium sulfate hemihydrate whiskers by hydrothermal method

Tianjie Liu, Hao Fan, Yanxia Xu, Xingfu Song, Jianguo Yu

期刊论文

Removal of Ni(II) ions from wastewater by micellar enhanced ultrafiltration using mixed surfactants

Amar D. Vibhandik, Kumudini V. Marathe

期刊论文

Simultaneous removal of total oxidizable carbon, phosphate and various metallic ions from HO solution

期刊论文

Diverse bacterial populations of PM in urban and suburb Shanghai, China

期刊论文

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

期刊论文

Analysis of mobilization of inorganic ions in soil by electrokinetic remediation

Xiaojing LI, Lige WANG, Xueming SUN, Yuansheng CONG

期刊论文

A ternary mechanism for the facilitated transfer of metal ions onto metal–organic frameworks: implications

期刊论文

Removal of Cu(II) ions from aqueous solution by activated carbon impregnated with humic acid

LIU Hanchao,FENG Suping,ZHANG Nannan,DU Xiaolin,LIU Yongli

期刊论文

Effects of natural zeolite and sulfate ions on the mechanical properties and microstructure of plastic

期刊论文