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101.
A simple, efficient, and general method has been developed for the one-pot synthesis of α-aminophosphonic esters in water using β-cyclodextrin as an efficient catalyst. α-Aminophosphonic esters were obtained in good yields (45-82%) and purity under mild conditions by the reaction of diethyl phosphite with a mixture of aldehyde and amine in water at reflux. 相似文献
102.
<正>An efficient and mild method for the direct conversion of alcohols into N-alkylphthalimides using 2,4,6-trichloro-1,3,5-triazine and dimethylformamide was described.The reaction was preceded via(alcoxymethylene) dimethylammonium chloride intermediate and produced corresponding N-alkylphthalimides in good-to-excellent yields. 相似文献
103.
A high speed, selective, and robust capillary electrophoresis (CE) method with high capacity was developed and validated for determination of assay of 1,4-dideoxy-1,4-imino-D-arabinitol in active pharmaceutical ingredients, solutions, and tablets during the development work at preclinical and Phase I and II clinical studies. 1,4-Dideoxy-1,4-imino-D-arabinitol, tartrate has (almost) no UV absorption. Therefore, the developed CE method for quantification was based on indirect UV detection. A cation CE principle was chosen using an electrolyte at pH 4.0 containing dimethyldiphenylphosphonium hydroxide, which has a strong UV absorbance. The quantification was performed using internal standard technique, by which piperidine was used as internal standard. The method was validated. The validation results showed that the CE method was suitable for the assay (and dissolution) analysis. 相似文献
104.
Yuanjian Li Xiang Feng Wei Ying Lieu Lin Fu Chang Zhang Tanmay Ghosh Anupma Thakur Brian C. Wyatt Babak Anasori Wei Liu Qianfan Zhang Jun Lu Zhi Wei Seh 《Advanced functional materials》2023,33(33):2303067
Rechargeable magnesium batteries (RMBs) are promising next-generation low-cost and high-energy devices. Among all RMBs, anode-free magnesium metal batteries that use in situ magnesium-plated current collectors as negative electrodes can afford optimal energy densities. However, anode-free magnesium metal batteries have remained elusive so far, as their practical application is plagued by low Mg plating/stripping efficiency due to nonuniform Mg deposition on conventional anode current collectors. Herein, for the first time, an anode-free Mg-metal battery is developed by employing a 3D MXene (Ti3C2Tx) film with horizontal Mg electrodeposition. The magnesiophilic oxygen and reactive fluorine terminations in MXene enable an enriched local magnesium-ion concentration and a durable magnesium fluoride-rich solid electrolyte interphase on the Ti3C2Tx film surface. Meanwhile, Ti3C2Tx MXene exhibits a high lattice geometrical fit with Mg (≈96%) to guide the horizontal electrodeposition of Mg. Consequently, the developed Ti3C2Tx film achieves reversible Mg plating/stripping with high Coulombic efficiencies (>99.4%) at high-current-density (5.0 mA cm−2) and high-Mg-utilization (50%) conditions. When this Ti3C2Tx film is coupled with a pre-magnesized Mo6S8 cathode, the anode-free Mg-metal full-cell prototype exhibits a volumetric energy density five times higher than its standard Mg-metal counterpart. This work provides insights into the rational design of anode current collectors to guide horizontal Mg electrodeposition for anode-free Mg metal batteries. 相似文献
105.
In this work, a new method for highly efficient and selective oxidative deprotection of a variety of structurally diverse trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBS) ethers using molecular oxygen in the presence of N-hydroxyphthalimide (NHPI) and various types of Co(II) complexes is reported. As a result of the relatively neutral reaction medium, acid-sensitive functional groups such as phenolic TBS ethers survived intact under the presented reaction conditions. 相似文献
106.
Debarshi Chakraborty Hadi Gholami Aritra Sarkar Leo A. Joyce James E. Jackson Babak Borhan 《Chemical science》2021,12(5):1750
A simple chiroptical solution for the absolute stereochemical determination for asymmetric phosphorus V stereocenters is presented. Strong coordination of the phosphorus oxide with the Zn-metallo center of the racemic host Zn-MAPOL 2 leads to an induced axial chirality of the host, yielding a strong ECCD signal. A mnemonic is proposed to correlate the asymmetry of the guest molecule with the observed ECCD signal.A simple chiroptical solution for the absolute stereochemical determination for asymmetric phosphorus V stereocenters is presented. 相似文献
107.
E. A. Merkovich M.-L. Carruette V. G. Babak G. A. Vikhoreva L. S. Gal'braikh V. E. Kim 《Colloid Journal》2001,63(3):350-354
The effects of glutaric aldehyde concentration C
GA(in the range from 0.07 to 0.2 wt %) and temperature T(from 20 to 65°C) on the kinetics of an increase in the effective viscosity effof aqueous solutions of chitosans (C
CH= 2.4 wt %, pH 3.6, and ionic strength I= 0.05) with molecular masses equal to 33 × 104and 55 × 104and the degrees of substitution at N-acetyl and amino groups of 0.08 and 0.90, respectively were studied. The kinetic curves eff(t) exhibited the induction periods of a relatively slight increase in the viscosity of chitosan–glutaric aldehyde mixed solutions with time followed by the periods of a drastic increase in the viscosity. The former periods correspond to the formation of gel clusters; the latter periods, to the gelation over the whole volume of a solution. Optimal ranges of the parameters C
GAand Twere determined for the preparation of spherical gel particles of slightly cross-linked chitosan, which are used for the sorption of heavy metals from low-concentrated solutions. 相似文献
108.
In this article, we introduce a novel link layer cooperation technique in noisy wireless networks to improve overall system
throughput and reliability, and to reduce the cost of retransmission and energy consumption. Under a cluster-based network
design, Chase combining (Chase, IEEE Transactions on Communications 33(5):385–393, 1985) is used together with FEC to improve
the link layer reliability. This approach is different from how combining is used in the conventional hybrid ARQ, which is
in a sequential way. The analytical results and the simulations show that with the cooperation of nodes in a clustering network,
the link reliability will be greatly improved with the same power consumption. We also show that not only transmission power
is greatly reduced, but also the aggregate power consumption for a successful transmission and reception. 相似文献
109.
Xin Zhang S. Ercelen V. E. Tikhonov S. Z. Karaeva A. V. Slita V. V. Zarubaev Y. Mély G. Duportail V. G. Babak 《Russian Journal of General Chemistry》2008,78(5):1093-1102
Low molecular weight chitosans (5 kDa) hydrophobically modified with 3, 10, and 18 mol % of tetradecenoyl (TDC) groups have been synthesized. Their good solubility at neutral pH, their surface activity and micelle-forming properties as well as their ability to interact with negatively charged phospholipid vesicles mimicking the internal layer of cell plasma membranes, allow us to consider them as potential non-viral transfection vectors for gene therapy. 相似文献
110.
Pan T Stay MS Barocas VH Brown JD Ziaie B 《IEEE transactions on bio-medical engineering》2005,52(5):948-951
We report on modeling and bench test results targeted at better understanding of valved glaucoma drainage devices (GDDs), a common current surgical treatment for glaucoma. A simple equivalent circuit is described to model fluid mechanical behavior of the aqueous humor in an eye with glaucoma, both before and after implantation of a valved GDD. Finite element method simulations (FEM), based on the lubrication-von Kármán model, are then performed to analyze the valve's mechanical and fluidic performance. Using nanoporous membranes to mimic the in vivo fibrous capsule, we have developed a microfluidic bench test to simulate the aqueous humor flow and the post-implantation fibrous tissue encapsulation around the GDD back plate. Our numerical and bench test results show that, contrary to the prevailing belief, the valve significantly contributes to the total pressure drop even after fibrous capsule formation. Furthermore, we show that bypassing the valve through a simple polyimide tube insertion will dramatically lower the intraocular pressure (IOP) after fibrous capsule formation. This may offer a new treatment option in some patients with advanced glaucoma. 相似文献