59 research outputs found
Interactions of microorganisms with rare earth ions and their utilization for separation and environmental technology
In recent years, rare earth elements (REEs) have been widely used in various modern technological devices and the global demand for REE has been increasing. The increased demand for REEs has led to environmental exposure or water pollution from rare earth metal mines and various commercial products. Therefore, the development of a safe technology for the separation and adsorption of REEs is very important from the perspective of green chemistry and environmental pollution. In this review, the application and mechanisms of microorganisms for the removal and extraction of REEs from aqueous solutions are described. In addition, the advantages in using microorganisms for REE adsorption and future studies on this topic are discussed.ArticleAPPLIED MICROBIOLOGY AND BIOTECHNOLOGY. 97(1):1-8 (2013)journal articl
B. I. T. : Development of a dynamic visualization tool for Bayesian inference on normal distributions
Bayesian inference Tool (B. I. T.) is a software program developed to support medical professionals and students in the application of Bayesian inference to medical decision-making and education. This software program makes it possible to visualize the posterior probability distributions of Bayesian inference. In addition, its interface aims to facilitate the intuitive understanding of the operative procedures. For many cases of Bayesian inference with normal distributions, the graphical representation of the posterior probability distribution changes dynamically when the input value is assigned by the user with the use of a computer mouse; this procedure also enables the dynamic calculation of the posterior probability. When operating this software, it is desirable for the user to have basic knowledge and understanding of the presuppositions as well as applications of Bayesian inference
Adsorption of rare earth ions onto the cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis
The aim of this study is to investigate the potential of cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis 168 to adsorb rare earth ions. Freeze-dried cell powders prepared from both strains were used for the evaluation of adsorption ability for the rare earth ions, namely, La(III), Eu(III), and Tm(III). The rare earth ions were efficiently adsorbed onto powders of both wild-type strain (WT powder) and lipoteichoic acid-defective strain (a dagger LTA powder) at pH 3. The maximum adsorption capacities for Tm(III) by WT and a dagger LTA powders were 43 and 37 mg g(-1), respectively. Removal (in percent) of Tm(III), La(III), and Eu(III) from aqueous solution by WT powder was greater than by a dagger LTA powder. These results indicate that rare earth ions are adsorbed to functional groups, such as phosphate and carboxyl groups, of lipoteichoic acid. We observed coagulated a dagger LTA powder in the removal of rare earth ions (1-20 mg L-1) from aqueous solution. In contrast, sedimentation of WT powder did not occur under the same conditions. This unique feature of a dagger LTA powder may be caused by the difference of the distribution between lipoteichoic acid and wall teichoic acid. It appears that a dagger LTA powder is useful for removal of rare earth ions by adsorption, because aggregation allows for rapid separation of the adsorbent by filtration.ArticleAPPLIED MICROBIOLOGY AND BIOTECHNOLOGY. 97(8):3721-3728 (2013)journal articl
Kitamura Electrophilic Fluorination Using HF as a Source of Fluorine
This review article focused on the innovative procedure for electrophilic fluorination using HF and in situ generation of the required electrophilic species derived from hypervalent iodine compounds. The areas of synthetic application of this approach include fluorination of 1,3-dicarbonyl compounds, aryl-alkyl ketones, styrene derivatives, α,β-unsaturated ketones and alcohols, homoallyl amine and homoallyl alcohol derivatives, 3-butenoic acids and alkynes.This research was funded by the National Natural Science Foundation of China (No. 21761132021), and IKERBASQUE, Basque Foundation for Science
Asymmetric Synthesis of N-Fmoc-(S)-7-aza-tryptophan via Alkylation of Chiral Nucleophilic Glycine Equivalent
Ni(II)-complexes, derived from glycine Schiff bases with chiral tridentate ligands, have been used as powerful tools for the synthesis of structurally diverse tailor-made amino acids. In this manuscript, asymmetric alkylation reaction between chiral nucleophilic glycine derived Ni-complex and 3-(chloromethyl)-1H-pyrrolo[2,3-b]pyridine has been developed under convenient conditions, which affords the corresponding alkylated Ni-complex in 74 % yield and excellent diastereoselectivity (only one isomer). This reaction features convenient conditions and completely controlled diastereoselectivity, which provides a highly valuable approach for asymmetric synthesis of 7-aza-tryptophan
Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles
In the present work, arylethynes were studied as new C-nucleophiles in the asymmetric Mannich addition reactions with (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimine. The reactions were conducted under operationally convenient conditions affording the corresponding Mannich adducts with up to 87% yield and 70:30 diastereoselectivity. The isomeric products can be separated using regular column chromatography to afford diastereomerically pure compounds. The purified Mannich addition products were deprotected to give the target enantiomerically pure trifluoromethylpropargylamines. A mechanistic rationale for the observed stereochemical outcome is discussedWe gratefully acknowledge the financial support from the National Natural Science Foundation of China (No. 21761132021) and Qing Lan Project of Jiangsu Province. IKERBASQUE, Basque Foundation for Science (for V. A. Soloshonok) is also acknowledged
Asymmetric Synthesis of Tailor-Made Amino Acids Using Chiral Ni(II) Complexes of Schiff Bases. An Update of the Recent Literature
Tailor-made amino acids are indispensable structural components of modern medicinal chemistry and drug design. Consequently, stereo-controlled preparation of amino acids is the area of high research activity. Over last decade, application of Ni(II) complexes of Schiff bases derived from glycine and chiral tridentate ligands has emerged as a leading methodology for the synthesis of various structural types of amino acids. This review article summarizes examples of asymmetric synthesis of tailor-made α-amino acids via the corresponding Ni(II) complexes, reported in the literature over the last four years. A general overview of this methodology is provided, with the emphasis given to practicality, scalability, cost-structure and recyclability of the chiral tridentate ligands.This research was funded by the National Natural Science Foundation of China (No. 21761132021), and IKERBASQUE, Basque Foundation for Science
Next generation organofluorine containing blockbuster drugs
Funding: the National Natural Science Foundation of China (No. 21761132021), the Hungarian Research Foundation (NKFIH No. K 119282), and Ministry of Human Capacities, Hungary grant 20391-3/2018/FEKUSTRAT. The Qinlan Project of Jiangsu Province, and IKERBASQUE, the Basque Foundation for Science are also acknowledged.The role of organo-fluorine compounds in modern health, food and energy related industries is widely-appreciated. The unique properties that fluorine imparts to organic molecules, stemming from its high electronegativity and stability when bound to carbon, finds it increasing being used in the development of new bioactivities. Around 25% of the current blockbuster drugs contain fluorine and this number is increasing to well above 30% for recent FDA approvals. In this Review we highlight a selection of the most successful organo-fluorine drugs, that have achieved blockbuster status, namely, sitagliptin (diabetes), sofosbuvir (hepatitis C), emtricitabine (HIV), glecaprevir/pibrentasvir (hepatitis C), elvitegravir (HIV), dolutegravir (HIV), bictegravir (HIV), efavirenz (HIV), enzalutamide (prostate cancer), aubagio (immunomodulatory) and paliperidone palmitate (schizophrenia). For each compound we discuss their discovery, their relevant disease state and how they are made, emphasizing the source of fluorine-containing moieties, and where known, their mode of action.PostprintPeer reviewe
A Transponder Aggregator with Efficient Use of Filtering Function for Transponder Noise Suppression
Colorless, directionless, and contentionless reconfigurable optical add/drop
multiplexing (CDC-ROADM) provides highly flexible physical layer network
configuration. Such CDC-ROADM must operate in multiple wavelength bands which
are being increasingly implemented in optical transmission systems. The
operation in C+L bands requires switch devices used in CDC-ROADM to also be
capable of multiband operation. Recent studies on wavelength division
multiplexing (WDM) systems have pointed out the impact of amplified spontaneous
emission (ASE) noise generated by signals of different wavelengths, which
causes OSNR degradation. Therefore, it is desirable to filter out the ASE noise
from different transponders when multiplexing multiple wavelengths at the
transmitter side, especially in a system with non-wavelength selective
combiners such as directional couplers and multicast switches. The use of
transponder aggregators with filtering functions, such as the M x N wavelength
selective switch (WSS), is preferable for this filtering. However, the downside
of these devices is that it is difficult to provide economical multiband
support. Therefore, we propose an economical transponder aggregator
configuration by allowing a certain amount of ASE superposition and reducing
the number of filtering functions. In this paper, we fabricated a prototype of
the proposed transponder aggregator by combining silica-based planar lightwave
circuit technology and C+L band WSS, both commercially available, and verified
its feasibility through transmission experiments. The novel transponder
aggregator is a practical solution for a multiband CDC-ROADM system with
improved OSNR performance.Comment: 10 pages, 11 figures. Submitted to IEEE Journal of Lightwave
Technology for possible publicatio
Present developments in reaching an international consensus for a model-based approach to particle beam therapy
Particle beam therapy (PBT), including proton and carbon ion therapy, is an emerging innovative treatment for cancer patients. Due to the high cost of and limited access to treatment, meticulous selection of patients who would benefit most from PBT, when compared with standard X-ray therapy (XRT), is necessary. Due to the cost and labor involved in randomized controlled trials, the model-based approach (MBA) is used as an alternative means of establishing scientific evidence in medicine, and it can be improved continuously. Good databases and reasonable models are crucial for the reliability of this approach. The tumor control probability and normal tissue complication probability models are good illustrations of the advantages of PBT, but pre-existing NTCP models have been derived from historical patient treatments from the XRT era. This highlights the necessity of prospectively analyzing specific treatment-related toxicities in order to develop PBT-compatible models. An international consensus has been reached at the Global Institution for Collaborative Research and Education (GI-CoRE) joint symposium, concluding that a systematically developed model is required for model accuracy and performance. Six important steps that need to be observed in these considerations include patient selection, treatment planning, beam delivery, dose verification, response assessment, and data analysis. Advanced technologies in radiotherapy and computer science can be integrated to improve the efficacy of a treatment. Model validation and appropriately defined thresholds in a cost-effectiveness centered manner, together with quality assurance in the treatment planning, have to be achieved prior to clinical implementation
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