Rapid determination of anionic surfactants in an aqueous medium by the ionassociation titration method coupled with a streaming potential detector

An ion-association titration method coupled with a streaming potential detector was developed for the determination of anionic surfactants in a one-phase aqueous system. The titrant, benzethonium chloride (Hyamine) ion, was added to an anionic surfactant solution. The potential then changed from negative to positive along with an increase in the added titrant. The end point was read from an inflection point of a diffrential curve. The usual samples were titrated within 10 min. Anionic surfactants at concentrations from 10(-5)10(-3) mol dm(-3) could be determined by the proposed method. The relative standard deviations of various anionic surfactants were 0.20.6%. The proposed method was applied to the determination of various anionic surfactants and anionic surfactants in commercial detergents. The results obtained for practical samples were in good agreement with those of the JIS titration method (Epton method).新しい流動電位検出器を用いたイオン会合滴定法による陰イオン界面活性剤の迅速定量法を開発した.陰イオン界面活性剤を陽イオン界面活性剤で滴定すると, 流動電位が負から正に変化することを用いて終点検出を行うという非常に簡単なもので, 更にクロロホルム溶媒を用いない水溶液系という特徴を有する.測定条件の最適化を行い, 10(-5)～10(-3)Mの濃度範囲の陰イオン界面活性剤を相対標準偏差0.2～0.5%と高精度で, 迅速自動定量 (10分/件) できることが分かった.陰イオン界面活性剤の各種標準及び実際試料について応用した結果, 定量値はJIS法 (Epton法) と非常に良い一致を示した

ニュウサンキン コウボ ニヨリ ハッコウ ジュクセイ サセタ ショクブツ ハッコウ エキス ノ ユウコウ セイ ニ カンスル ケンキュウ

植物性食品を中心とした食生活は、生活習慣病の予防や治療に効果があるとされている。乳酸菌や酵母により発酵熟成させた植物発酵エキスは、多種多様な植物性原料を用いて、発酵と糖蔵という伝統的な食品保存技術を応用した発酵食品である。本研究では、植物発酵エキスの有効性(栄養的特性や保健機能)に関する研究を行った。植物発酵エキスには、58.5%の炭水化物、3.7%のタンパク質、1.3%の脂質をはじめ、18種類のタンパク質構成アミノ酸や種々のビタミン類、食物繊維、ファイトケミカル(ポリフェノール、テルペノイド等)が含まれていた。さらに、植物発酵エキスは抗酸化作用、血圧上昇抑制作用、抗菌作用、抗アレルギー作用、抗炎症作用、チロシナーゼ阻害作用を有していることを「in vitro 試験」により明らかにした。A plant-based diet is thought to be better for the prevention and treatment of lifestyle-related diseases. A plant-based extract fermented by lactic acid bacteria and yeast (PELY) was made from various plant materials and was fermented product applying to traditional food-preservation technique, that is, fermentation and sugaring. In this study, the characterization and physiological function of PELY were examined.PELY contained 58.8% carbohydrate, 3.7% protein, and 1.3% lipid. It contained 18 kinds of amino acids and vitamin A, B1, B2, B6, B12, E, K, niacin, pantothenic acid, and folic acid. It also did a lot of dietary fiber and phytochemicals (polyphenol, terpenoid, i.e.).Moreover, PELY had several physiological functions such as antioxidant, antihypertensive, antibacterial, anti-allergy, anti-inflammatory and anti-tyrosinase activities in vitro

Pushing property limits in materials discovery via boundless objective-free exploration

Materials chemists develop chemical compounds to meet often conflicting demands of industrial applications. This process may not be properly modeled by black-box optimization because the target property is not well defined in some cases. Herein, we propose a new algorithm for automated materials discovery called BoundLess Objective-free eXploration (BLOX) that uses a novel criterion based on kernel-based Stein discrepancy in the property space. Unlike other objective-free exploration methods, a boundary for the materials properties is not needed; hence, BLOX is suitable for open-ended scientific endeavors. We demonstrate the effectiveness of BLOX by finding light-absorbing molecules from a drug database. Our goal is to minimize the number of density functional theory calculations required to discover out-of-trend compounds in the intensity–wavelength property space. Using absorption spectroscopy, we experimentally verified that eight compounds identified as outstanding exhibit the expected optical properties. Our results show that BLOX is useful for chemical repurposing, and we expect this search method to have numerous applications in various scientific disciplines

Estimation of Enantiomeric Excess Based on Rapid Host–Guest Exchange

Chiral molecules possess enantiomers that have non-superimposable chemical structures but exhibit identical nuclear magnetic resonance (NMR) spectra. This feature prevents the use of NMR spectroscopic methods for the determination of enantiomeric excesses (ee) of chiral molecules, using simple mixtures of their enantiomers. Recently, however, it was reported that the addition of a symmetrical prochiral molecule (a reporter or host) into a solution of chiral analyte can lead to estimation of ee through interactions involving rapid exchange of the chiral analyte (guest) in the formed host–guest complex. This is due to the ee-dependent splitting of NMR resonances of the prochiral host molecule based on averaging the chemical shift non-equivalency caused by the presence of a chiral guest. The mechanism is not dependent on diastereomer formation, and 1:1 host–guest complexes can also show ee-dependent NMR peak splitting. Prochiral molecules capable of ee sensing using the NMR technique are now referred to as so-called prochiral solvating agents (pro-CSAs). pro-CSAs represent a family of reagents distinct from the commonly used NMR chiral derivatizing reagents (where chiral auxiliaries are used to derivatize enantiomers to diastereomers) or chiral solvating agents (where chiral auxiliaries interact in an asymmetric manner with analyte enantiomers). pro-CSA methods are unique since neither pro-CSA nor NMR contains chiral factors, making the technique neutral with respect to chirality. Here, we review our recent work on this matter involving several different nominally achiral receptor molecules whose unique guest binding properties and solution characteristics (especially with regard to NMR spectroscopy) allow for the estimation of ee in the corresponding chiral guests

Soft chromophore featured liquid porphyrins and their utilization toward liquid electret applications

Optoelectronically active viscous liquids are ideal for fabricating foldable/stretchable electronics owing to their excellent deformability and predictable π-unit-based optoelectronic functions, which are independent of the device shape and geometry. Here we show, unprecedented 'liquid electret' devices that exhibit mechanoelectrical and electroacoustic functions, as well as stretchability, have been prepared using solvent-free liquid porphyrins. The fluidic nature of the free-base alkylated-tetraphenylporphyrins was controlled by attaching flexible and bulky branched alkyl chains at different positions. Furthermore, a subtle porphyrin ring distortion that originated from the bulkiness of alkyl chains was observed. Its consequences on the electronic perturbation of the porphyrin-unit were precisely elucidated by spectroscopic techniques and theoretical modelling. This molecular design allows shielding of the porphyrin unit by insulating alkyl chains, which facilitates its corona-charged state for a long period under ambient conditions

Self-Expandable Metal Stent Placement as a Bridge to Laparoscopic or Open Surgery for Obstructive Colorectal Cancer: Short-Term Outcomes of Nineteen Consecutive Cases

Purpose Laparoscopic colorectal resection is a feasible and less invasive procedure with short-term advantages compared with open surgery; however, the evidence for its efficacy for treating obstructive colorectal cancer (CRC) is lacking. In this study, we aimed to determine short-term outcomes of SEMS placement for obstructive CRC followed by laparoscopic colorectal resection.Methods As of August 2013, 51 patients with obstructive CRC underwent stent insertion. Thirty-two patients received palliation therapy not intended for tumor resection. After decompression of the proximal intestine, nine and 10 patients underwent laparoscopic and open surgery, respectively. Clinicopathological, intraoperative, and postoperative data were retrospectively collected.Results There were no differences in resection rates and curabilities between the two groups. All surgeries were performed with a single-stage anastomosis, and no anastomotic leakage was observed. There was one patient with abdominal morbidity in the open group (Open) and none in the Lap group. There was no mortality in either group. Time to flatus (3.4 ± 1.8 days, Lap; 2.6 ± 1.1 days, Open) and time to oral intake (7.9 ± 2.5 days, Lap; 7.7±1.9 days, Open) were similar between the groups. Postoperative hospitalization times for the Lap group were shorter, but the difference was not statistically significant (15.2 ± 3.9 days, Lap; 21 ± 11.7 days, Open, p = 0.21).Conclusion Our findings indicate that laparoscopic surgery combined with preoperative stent placement is feasible as well as safe compared with open surgery for obstructive CRC

De novo creation of a naked eye–detectable fluorescent molecule based on quantum chemical computation and machine learning

Designing fluorescent molecules requires considering multiple interrelated molecular properties, as opposed to properties that straightforwardly correlated with molecular structure, such as light absorption of molecules. In this study, we have used a de novo molecule generator (DNMG) coupled with quantum chemical computation (QC) to develop fluorescent molecules, which are garnering significant attention in various disciplines. Using massive parallel computation (1024 cores, 5 days), the DNMG has produced 3643 candidate molecules. We have selected an unreported molecule and seven reported molecules and synthesized them. Photoluminescence spectrum measurements demonstrated that the DNMG can successfully design fluorescent molecules with 75% accuracy (n = 6/8) and create an unreported molecule that emits fluorescence detectable by the naked eye

Les normes, comment?

La description normalisée des ressources d’enseignement et d’apprentissage requiert l’utilisation d’outils d’implantation conformes aux conventions d’un standard ou d’une norme internationale et un réseau d’entraide et d’accompagnement