Search

Mixed acid nitration of electrochemically generated 4,4',5,5'-tetraamino-3,3'-azo-bis-1,2,4-triazole (TAABT) generated the novel energetic material 4,4'-dinitrimino-5,5'-diamino-3,3'-azo-bis-1,2,4-triazole (DNDAABT). Various energetic salts of DNDAABT were also prepared and characterized to confirm their structures and determine their explosive sensitivities and performances. The free acid of DNDAABT exists as a zwitterionic molecule that leads to a high-density material with predicted detonation parameters comparable to those of TKX-50 (bis(hydroxylammonium) 5,5'-bis(tetrazolate-1 N-oxide). Due to the insensitive nature of TAABT, it was predicted that DNDAABT would demonstrate remarkably low sensitivities for a primary N-nitramine. However, it was found that DNDAABT and all salts produced have primary explosive sensitivities, albeit with relatively high thermal stabilities for primary N-nitramines.

The study aimed to examine the quality of honey from the Middle Podrinje area (Bosnia and Herzegovina). The research included a total of 21 samples of honey from the Middle Podrinje area: 12 samples of honey florals (municipalities of Srebrenica and Milići), 9 samples of acacia honey (municipalities of Zvornik and Bratunac). Physico-chemical parameters were determined as the main composition criteria for quality assessment in honey samples: mass fraction of water, total acidity, electrical conductivity, and ash. Samples of honey florals are of poorer quality compared to acacia honey, two samples had values of water content and acidity above the values prescribed by the Regulation. Statistical analysis showed that there is a statistically significant difference between the arithmetic means of the water content for floral honey, the electrical conductivity of acacia honey, and the free acid content for both types of honey. Honey samples that met the criteria prescribed by the Regulation were sensory evaluated by experienced analysts. Two samples of floral honey that did not meet the criteria prescribed by the Regulation were not sensory evaluated. Based on sensory analysis, samples of floral honey from the municipality of Milići had better sensory characteristics compared to the same type of honey from the municipality of Srebrenica. Acacia honey from the municipality of Zvornik was rated better than honey from the municipality of Bratunac.

Mandar coconut oil made in Tulu village, Majene Regency, West of Sulawesi, is very popular among Sulawesi Barat people. It is because of the unique aroma which is not owned by other Mandar oil traders. In addition, according to Mandar coconut oil trader who is also the produsen of Mandar oil said that his coconut oil could be stored for months. This research aimed to know the influence of water content and free fatty acid content on Mandar coconut oil shelf life. Gravimetric Method and Alkaline method were used to determine the water content and the free fatty acid content respectively. The oil was stored at room temperature. Water content and free acid content were measured every week, i.e week zero to week four (5 observations). Shelf life estimation was done by applying the kinetic theory. The result shows that the water content and the free fatty acid content increase as shelf life increases. Mandar coconut oil can be stored at room temperature for 1 month, 12 days. Keywords: Mandar coconut oil, water content, free fatty acid, shelf life

Background Ghŗta mūrcchana is a process of pre-treatment recommended in Ayurveda to purify ghee before it can be used for siddha ghŗta which is claimed to improve the properties of the ghee in general and that of the prepared siddha ghŗta. Objective This work is aimed at studying the physiochemical properties of ghee and mūrcchita ghŗta in order to understand the impact of ghŗta mūrcchana process. Materials and methods Ghee and mūrcchita ghŗta were prepared from the milk of local Pahadi, Jersey and Holstein cows. The samples were characterized by FTIR spectroscopy, differential scanning calorimetry and free fatty acid measurements. Results Among the samples studied, the Holstein cow ghee was found to contain the least amount of free acid (1.34%) whereas ghŗta mūrcchana process led to further decrease in the free acid content polymorphism was observed in the samples as evidenced by multiple melting points. In most cases, mūrcchita ghŗta was found to contain less solid fat than the corresponding ghee implying that the high melting compound was converted to low melting one during the process. Conclusion The observed lowering of free fatty acid and solid fat contents in the ghee samples may provide a possible validation to the performance enhancement of the ghŗta mūrcchana process.

International audience; Various protected β2-amino acids can be prepared by radical addition of β-phthalimido-α-xanthyl propionic acid, both as the free acid or as the ethyl ester. Successive radical additions provide access to more complex structures. In the case of the free acid, addition to certain heteroaromatics leads directly to β-heteroarylethylamines through spontaneous decarboxylation of the intermediate adduct. Forcing the decarboxylation in some cases generated a vinyl group by decarboxylative elimination of the phthalimido group.

Following the worldwide trend of developing heavy metal free materials, dental implants aren’t out of this tendency. Over the years, a number of techniques to condition the surface of dental implants have been designed and used such as oxide blasting, however the scientific medical community has been concerned about the use of these heavy metals which leads us to investigate and develop new conditioning techniques. The aim of the study was the analysis of the Systhex® implant surface in automatic system for the treatment of the surface with acid, where we can identify the surfaces purity level, pore size, deepness and especially the roughness proportionated by the technology of acid conditioning on the titanium surfaces of degree IV dental implants. We conclude that the automatic conditioning of acid attack promoted cleanliness, homogeneity and ideal roughness for the osseointegration process.

The purpose of the present study was to evaluate the prediction accuracy of a mechanism-based oral absorption model for the fraction of a dose absorbed (Fa) in dogs, focusing on poorly soluble drugs. As an open mechanism-based model, the gastrointestinal unified theoretical framework was used in this study. The prediction accuracy of the gastrointestinal unified theoretical framework was evaluated using Fa data in dogs (63 data sets for marketed drugs and proprietary compounds). For neutral compounds, Fa was accurately predicted, suggesting that the physiological parameters of dogs were appropriate except for gastrointestinal pH. An extensive literature survey on the small intestinal pH of dogs was then conducted. The result suggested that the pH value ranged between 6.5 and 7.5, with the midst value of 7.0, but there was a great variation among the literature. To confirm the appropriateness of this pH value, the Fa of free acid compounds was predicted by setting the small intestinal pH to 6.5, 7.0, and 7.5. The proportions of compounds with

A combination of the density and Raman measurements for rapid in situ determination of uranium concentration and free acid molarity in uranyl nitrate solutions is proposed. Laboratory validation and field tests performed using a portable handheld density meter and a handheld Raman spectrometer demonstrated a feasibility of the approach in the range of uranium concentration from 50 to 426 g L−1, and free acid molarity ≤ 3 M. The combined standard uncertainties of the uranium and free acidity determination were found to be 2.4% and 5.7%, respectively. Potentials of the method in safeguards and process control applications are highlighted.

β-hydroxy-β-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxyisocaproic acid (α-HICA) are leucine metabolites that have been proposed to improve body composition and strength when combined with resistance exercise training (RET). In this double-blind randomized controlled pragmatic trial, we evaluated the effects of off-the-shelf supplements: α-HICA, HMB-FA and HMB-Ca, on RET-induced changes in body composition and performance. Forty men were blocked randomized to receive α-HICA (

Introduction: Carbohydrate (CHO) is essential for physical exercise. Some strategies for improving performance are based on the manipulation of the glycemic index (GI) of this nutrient during pre-exercise. Although several studies have been conducted on this subject, the use of low or high GI in a pre-exercise meal to improve performance remains undefined. Methods: In the present systematic review, the Pubmed (Medline) and Virtual Health Library databases were searched for randomized clinical trials conducted with healthy, physically active adults between 2006 and 2019, in which performance in addition to blood biochemical parameters, substrate utilization, body composition, perception of effort, and gastrointestinal symptoms were evaluated. The identified articles were independently and blindly evaluated by two authors, and any disagreements were resolved by a third investigator. Results: Five of the sixteen studies reviewed found differences in performance; of these, four were with low GI intervention. Few studies showed modifications in blood lactate and glucose levels beyond fatty free acid oxidation. No differences could be seen in the other parameters. The results as well as the methodologies used were heterogeneous; therefore, there are no clear advantages in determining the specific GI of the pre-exercise meal. Conclusions: There is no evidence that the pre-exercise meal GI influences performance. The heterogeneity of the studies precludes further conclusions.

NG,NG-Dimethyl-L-arginine (asymmetric dimethylarginine, ADMA) is a cardiovascular risk factor. ADMA circulates in blood as a free acid (fADMA) and as constituent of not yet identified proteins (prADMA). We describe here a protocol for the GC-MS quantification of ADMA released from serum proteins using 6 M HCl (110 °C, 20 h). L-Homoarginine (hArg) is useful in measuring digestibility of amino acids in food proteins. We demonstrate that hArg is not present in human serum proteins and is useful in measuring serum prADMA. The concentration of prADMA in elderly subjects is about 90 nM and the average fADMA/prADMA ratio 6:1.

The low operating voltage of 1.4 V limits the widespread application of flexible Zn-air batteries (ZABs) in wearable electronics. However, a high-voltage flexible ZAB has not been achieved yet, which results from the few choices of fitted flexible electrolytes. Now we propose a novel, universal, and simple strategy to design all-in-one and membrane-free acid-alkaline flexible electrolytes based on thermo-reversible Pluronic® F127 hydrogels. Benefiting from the unique sol–gel transition property of Pluronic® F127 hydrogel, the acid and alkaline can be decoupled but integrated simultaneously in one hydrogel. Surprisingly, the as-developed ZAB achieves an unprecedentedly high voltage of 2 V, surpassing all the existing flexible ZABs. Meanwhile, this battery exhibits remarkable high-voltage stability of 37 h and a large area capacity of 1.35 mAh cm−2 without the use of costly bipolar membranes. Our work presents a pioneering example for flexible high-voltage ZAB and may further inspire other designs of flexible high-voltage aqueous batteries and decoupled dual-electrolyte batteries.

Nitroacetonitrile is the simplest α-nitronitrile; it possesses a single central carbon attached to two strong electronegative, electron-withdrawing groups allowing extensive chemistry through the active methylene center. Free nitroacetonitrile has purification and stability issues, however stable salts of nitroacetonitrile possess the same reactivity as the free acid and are much more stable. Nitroacetonitrile serves as a versatile synthetic precursor in the formation of heterocyclic and polyfunctional aliphatic products and can allow for straightforward conversion to amino, acyl, and other functional groups. A main advantage of using nitroacetonitrile in the formation of heterocyclic-based energetics is its ability to add vicinal amino and nitro moieties onto fused ring structures, a common structural motif in insensitive energetic materials. In this minireview we discuss the preparation of nitroacetonitrile and its stable salts, as well as discuss the range of energetic materials this versatile precursor has found use in.

Crystallographic studies of monosulfonated azo dyes have concentrated on the salt forms that contain the azo anion. Here we present a study that compares the structures of these anions with protonated free acid forms and with doubly deprotonated dianion forms. To this end, the new single crystal diffraction structures of 13 systematically related free acid forms of monosulfonated azo dyes are presented, together with three new structures of doubly deprotonated forms and two new structures of Na salt forms of azo anions. No structures of dideprotonated monosulfonated azo dyes have previously been reported and this paper also reports the first crystal structure of an azo dye with a hydronium cation. The geometries of the free acid, anion and dianion forms are compared to literature equivalents. It is shown that protonation of the azo bond gives predictable bond lengthening and shortening, which is of a greater magnitude than similar effects caused by azo-hydrazone tautomerisation, or the smaller again effects caused by the resonance electron donation from O or N based substituents. The dianion containing structures have twisted dianion geometries that can be understood based on the resonance effects of the phenoxide groups and upon the needs to bond to a relatively high number of metal cations.

Dogs have been widely used to study the oral absorption of a drug in drug discovery. However, there has been no quantitative validation of using dogs to predict the fraction of oral dose absorbed (Fa) in humans (Fah) for poorly water-soluble drugs. Here, we report the results of using dogs for quantitative Fah prediction, focusing on poorly water-soluble free acid and neutral drugs. The Fa values of 4 acidic and 1 neutral proprietary compounds were measured in humans and dogs. Extensive literature survey was also performed to increase the number of Fa data. Fah and Fa in dogs (Fad) were then compared at equivalent body weight-normalized doses. In the case of neutral compounds, Fad was found to be similar to Fah. In the case of acidic compounds, Fad significantly overestimated Fah in most cases. A difference in intestinal pH was suggested as the main reason for this discrepancy. In conclusion, the use of dogs would not be appropriate to predict Fah for acidic compounds, but more work is required to know about neutral compounds.

This research objective has to show the effectivity of the using biosorbent Papaya seed to recondition of fried oil quality. The adsorption mechanizme and the factors effected to performance of biosorbent must studied Comprehensively. Totality of extent particle surface and the long time of biosorbent with adsorbed interface determined performance adsorption. The research was compiled to producing and activating Papaya seed as biosorbent; and then to do the experiment for effectivity biosorbent according with Complete Random Factorial Design, with two factor namely Mass biosorbent to Volume fried oil ratio (A 1 =5 %, A 2 = 10 %, A 3 = 15 %, dan A 4 = 20 % (b/v) , and the long time of biosorbent fried oil interface (L 1 = 2, L 2 = 4, L 3 = 6, dan L 4 = 8 days). The result of data analysis to show that effect of Mass biosorbent to Volume fried oil ratio factor have significant different among factor level properly (p

Acyl-coenzyme A (CoA) ligases catalyze the activation of carboxylic acids via a two-step reaction of adenylation followed by thioesterification. Here, we report the discovery of a non-adenylating acyl-CoA ligase PtmA2 and the functional separation of an acyl-CoA ligase reaction. Both PtmA1 and PtmA2, two acyl-CoA ligases from the biosynthetic pathway of platensimycin and platencin, are necessary for the two steps of CoA activation. Gene inactivation of ptmA1 and ptmA2 resulted in the accumulation of free acid and adenylate intermediates, respectively. Enzymatic and structural characterization of PtmA2 confirmed its ability to only catalyze thioesterification. Structural characterization of PtmA2 revealed it binds both free acid and adenylate substrates and undergoes the established mechanism of domain alternation. Finally, site-directed mutagenesis restored both the adenylation and complete CoA activation reactions. This study challenges the currently accepted paradigm of adenylating enzymes and inspires future investigations on functionally separated acyl-CoA ligases and their ramifications in biology. Functional and structural characterization of PtmA2 reveals that it is an unusual non-adenylating acyl-CoA ligase and part of a system wherein the canonical acyl-CoA ligase reaction is separated into two half-reactions performed by distinct enzymes.

Review the results of his own observations, as well as the literature of the last years, F. in the following way draws us the state of the issue of osteomalacia. Bone softening is not a disease inherent exclusively to the pelvic bones; in difficult cases, the bones of the spine, thighs, thorax, even the upper limbs and the skull are also affected. In essence, osteomalacia is an inflammatory disease: the decay of bone tissue takes over growth. What determines the dissolution of calcium salts remains unclear: the hypothesis of the presence of free acid in the tissues of the bone marrow is hardly probable.

The purpose of this study was to compare the coadministration of the probiotic Bacillus coagulans GBI-30, 6086 (BC30) with β-hydroxy-β-methylbutyrate (HMB) calcium (CaHMB) to CaHMB alone on inflammatory response and muscle integrity during 40 days of intense military training. Soldiers were randomly assigned to one of two groups: CaHMB with BC30 (CaHMBBC30; n = 9) or CaHMB with placebo (CaHMBPL, n = 9). A third group of participants served as a control (CTL; n = 8). During the first 28 days soldiers were garrisoned on base and participated in the same training tasks. During the final 2 wk soldiers navigated 25–30 km per night in difficult terrain carrying ~35 kg of equipment. All assessments (blood draws and diffusion tensor imaging to assess muscle integrity) were conducted before and ~12 h after final supplement consumption. Analysis of covariance was used to analyze all blood and muscle measures. Significant attenuations were noted in IL-1β, IL-2, IL-6, CX3CL1, and TNF-α for both CaHMBBC30 and CaHMBPL compared with CTL. Plasma IL-10 concentrations were significantly attenuated for CaHMBBC30 compared with CTL only. A significant decrease in apparent diffusion coefficients was also observed for CaHMBBC30 compared with CaHMBPL. Results provide further evidence that HMB supplementation may attenuate the inflammatory response to intense training and that the combination of the probiotic BC30 with CaHMB may be more beneficial than CaHMB alone in maintaining muscle integrity during intense military training. NEW & NOTEWORTHY β-Hydroxy-β-methylbutyrate (HMB) in its free acid form was reported to attenuate inflammation and maintain muscle integrity during military training. However, this formulation was difficult to maintain in the field. In this investigation, soldiers ingested HMB calcium (CaHMB) with Bacillus coagulans (BC30) or CaHMB alone during 40 days of training. Results indicated that CaHMB attenuated the inflammatory response and that BC30 combined with CaHMB may be more beneficial than CaHMB alone in maintaining muscle integrity during intense military training.

Gastric ulcer is one of the increase gastric acid causes which mediated by H 2 reseptor. Tumeric is extracted using the ethanol 96% and it is tested using Rattus norvegicus Wistar strain to know the effect as anti gastritis. There’s a suspicion whether an ethanol extraction from tumeric which has anti H 2 receptor effect can be use to prevent gastric ulcer causes from histamine release. Based on that, we want to study whether tumeric can be use to prevent the increase of histamine induce gastric acid and can also be use as gastric protective by looking at microscopic image of gastric, gastric pH from Rattus norvegicus Wistar strain. Methods : Male Wistar rats were divided Into five groups: 1) Na CMC control group, 2) CMC Na io histamine plus 300 mg / kg ip groups, 3) ethanol turmeric extract 1000 mg / kg io histamine plus 300 mg / kg ip treated groups, 4) ethanol turmeric extract 2000 mg / kg io histamine plus 300 mg / kg ip treated groups. Rats were sacrified at 6 h after injection of histamine, and stomach tissues were harvested for free acid, total acid, organic acid, pH. Results : Giving P2 ethanol extract of tumeric intra oral decrease free acid level, total acid, organic acid and pH gastric acid which is induced by giving an intra peritoneal histamin. Ethanol extract of tumeric decrease incidence and preventable for ulcus gastric causes by histamin. Conclusion : an ethanol extract of tumeric decrease the levels of free acid, total acid, organic acid and pH gastric. Ethanol tumeric extract 2000 mg/kg is a recommended dosage

Conductivity is one of the key physico-chemical properties of electrolyte in silver electrorefining since it affects the energy consumption of the process. As electrorefining process development trends towards high current density operation, having electrolytes with high conductivities will greatly reduce the energy consumption of the process. This study outlines investigations into silver electrorefining electrolyte conductivity as a function of silver, free acid, copper and lead concentration at different temperatures via a full factorial design comprising of 246 individual measurements. Regression analysis of the model was used to determine the goodness of fit R 2 , goodness of prediction Q 2 , model validity and reproducibility. Conductivity was shown to be enhanced by increases in free acid, copper, silver and lead, with free acid having the highest impact on conductivity. Temperature also increased conductivity in two ways: both as a single factor and as a combined effect with free acid, silver and copper concentration. Overall, this work produced a model of high accuracy that allows conductivity of a range of industrial silver electrorefining conditions to be calculated.

The organic olives from Cine-Aydin (Turkey) were washed with tap or ozonated water for 2 and 5 min, respectively, and pressed to olive oil. The effects of wash treatments on fatty acid composition and several quality parameters of the oils were determined. The maximum values after 2-min ozonated water washes were 9.58 meqO2/kg, 0.73%, 2.44 and 0.16 for peroxide, free acid, K232 and K270 values, respectively, which were under the standard limits for extra-virgin olive oil. Five min of ozonated water washes also yielded acceptable results, except for a slight excess on K232 value. Ozonated water washes had almost no effect on fatty acid composition.

A separation method for W and Mo from peroxoacids solution by thermal decomposition was studied. Thermal decomposition of peroxotungstic acid and peroxomolybdic acid was investigated respectively. The results confirmed that peroxomolybdic acid showed a preferable stability compared with peroxotungstic acid. This thermal stability difference was the basic principle of the separation of W and Mo. Experiments were performed to study the effects of temperature, stirring speed, free acid concentration and Mo concentration on the separation efficiency. The results indicated that peroxotungstic acid decomposed into tungstic acid (H 2 WO 4 ) and precipitated selectively, while Mo was rejected in aqueous solution, realizing good separation of W and Mo. The separation factor of W and Mo reached 112 under the studied conditions, which indicated that this method has potential for use in separating W and Mo.

Purpose: The purpose of this study was to examine the effect of 𝛽-hydroxy-𝛽 methylbutyrate-free acid (HMB-FA) ingestion on oxidative stress and leukocyte responses to plyometric exercise. Methods: In a randomized double-blind placebo-controlled design, physically active males were assigned to the HMB-FA (n=8) or placebo (n=8) groups that consumed either 1 g of HMB-FA or placebo 30 min prior to performing an acute plyometric exercise protocol (15 sets of 10 repetitions of maximal-effort vertical jumps). Blood was obtained pre (T1), post (T2), and 1-hour post (T3) exercise to determine changes in serum levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), malondialdehyde (MDA), protein carbonyl (PC), and white blood cells (WBC). Results: The exercise protocol significantly elevated 8-OHdG (HMB-FA, T2 9.5 % and T3 12.6%; placebo, T2 18.2% and T3 36.5%), MDA (HMB-FA, T2 11.6% and T3 25.2%; placebo, T2 11.8% and T3 41%) and PC (HMB-FA, T2 6.9% and T3 25%; placebo, T2 23.4% and T3 55.3%) at post and 1-hour post exercise, respectively. However, at 1-hour post exercise, greater increases in oxidative stress markers (8-OHdG 36.5 vs. 12.6%; MDA 41 vs. 25.1% and PC 55.3 vs. 25%) were observed in the placebo group compared to the HMB-FA group (p

The presence of n -alkanes, free alcohols and free acids in leaf epicuticular wax extracts of 22 samples of 11 Euphorbia L. species belonging to the sections Paralias , Esula , Myrsiniteae and Helioscopia , 10 of which were never examined before, were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), and n -alkane C27 was detected as the principal component of leaf epicuticular waxes in the majority of the examined species, while the most abundant free alcohol was C26. Three Euphorbia species belonging to section Helioscopia were characterized by a predominance of alcohol C28. Free acid (C16) was the major component in 21 investigated samples. The usefulness of n -alkanes and free alcohols and free acids as potential chemotaxonomic markers is briefly discussed. https://doi.org/10.2298/ABS180608041K Received: June 8, 2018; Revised: August 31, 2018; Accepted: September 12, 2018; Published online: September 21, 2018 How to cite this article: Krstic G, Aljancic I, Stankovic J, Cvetkovic M, Marin P, Janackovic P, Tesevic V. Leaf epicuticular waxes of eleven Euphorbia species (Euphorbiaceae) from the Central Balkans: Impact on chemotaxonomy. Arch Biol Sci. 2019;71(1):21-6.

This study evaluated the effects of β-hydroxy-β-methylbutyrate free acid (HMB-FA) and calcium salt (HMB-Ca) on strength, hypertrophy, and markers of muscle damage. In this randomized, double-blind, placebo-controlled study, 44 resistance-trained men (age: 26 ± 4 years; body mass: 84.9 ± 12.0 kg) consuming ≥1.7 g·kg−1·day−1 of protein received HMB-FA (3 g/day; n = 14), HMB-Ca (3 g/day; n = 15), or placebo (PL; cornstarch, 3 g/day; n = 15) for 12 weeks, while performing a periodized resistance training program. Before and after intervention, lean body mass (measured with dual X-ray absorptiometry), maximal dynamic strength (one-repetition maximum), knee extension maximal isometric strength (maximal voluntary isometric contraction [MVIC]), cross-sectional area (measured with ultrasound), and muscle soreness were assessed. MVIC was also measured 48 hr after the first and the last training sessions. All groups increased lean body mass (main time effect: p p p p p

In this paper, Fe2O3 power was used to replace the scrap steel in the traditional process, as the medium for removing the free acid in the waste acid solution of the cold-rolled strip pickling. The removal effect of free acid and silicon of the system with Fe2O3 addition and crap steel were compared. The results indicated that the system with Fe2O3 addition obtained a better effect. Subsequently, the optimum dosage, optimum reaction temperature and time were determined by the orthogonal experiment. The effect of flocculants of polyacrylamide (PAM), PAC, PAM+PAC and MgCl2 with the desiliconization was explored.

Activity of human CYP26A1 towards six proluciferin probe substrates and their ester derivatives was monitored. These included three monofluorobenzyl ether isomers and three five-membered heterocycles. Overall, luciferin substrates with a free acid group gave higher activities than the ester compounds. Also, luciferin derivatives with six-ring structures were better metabolized than those with five-rings. The best substrates identified in this study are Luciferin 6′ 3-fluorobenzyl ether (Luciferin-3FBE) and its methyl ester (Luciferin-3FBEME). Taken together, we describe eleven new probe substrates for CYP26A1 and demonstrate for the first time that CYP26A1 does not only accept acid substrates but can also metabolize esters., Highlights • Eleven new probe substrates for CYP26A1 were identified. • CYP26A1 is shown to metabolize ester substrates. • The best probe substrate identified is Luciferin 6′ 3-fluorobenzyl ether.

The structural properties of various salts of methanetrisulfonic acid (H3mts) are described, spanning the free acid, ammonium and alkali metals (Na, K, Cs), first row transition metals (Cr, Co−Zn), and lead. A number of different coordination modes is found, including unexpected motifs such as the κ3O1,4,7 coordination in the lead salt and anions of the type [M(H2O)4(κ2O1,4-mts)]− (M=Co, Ni, Zn), which do not seem to be persistent in aqueous solution.

Absorption and translocation of aminocyclopyrachlor (AMCP) was investigated in black walnut. Radiolabeled AMCP was applied foliarly as a free acid, and basally as a free-acid-formulated oil-soluble liquid and as a methyl ester emusifiable concentrate. Maximum absorption was 68% for the methyl ester, 47% for the free-acid oil-soluble liquid, and 8% for the free acid when evaluated as percent applied. When recovered AMCP was presented as Bq g−1, no difference was observed in AMCP absorption or translocation of 14C-labeled material out of treated plant parts. Recovery of applied radiolabeled material in the roots from basal applications was 5 to 11% 72 h after treatment (HAT), compared with 0.8% recovery from a foliar application. Regardless of chemical form or formulation type, comparable injury was observed within 72 HAT despite low levels of translocation. Nomenclature: Aminocyclopyrachlor; black walnut, Juglans nigra L.

游离酸度的测量是在经过合适的方法去除水解离子干扰后用碱量滴定法进行的，这些方法包括离子交换、沉淀分离、溶剂萃取和配位剂抑制。配位掩蔽法操作简单、快速、准确、重现性好和实用，特别适用于快速化学分析水解离子干扰的溶液酸度。本文综述了过去几十年文献中报道游离酸度测定时抑制水解离子的配位剂的种类和应用，以及配位剂在酸度测定中的重要性，并结合实际提出了今后的发展前景。 The determination of free acidity is carried out using alkalimetric titration after the removal of the hydrolysable ion by a suitable method such as ion exchange, precipitation or solvent extraction or suppression by complexing the metal ions. The method for masking hydrolysable ions with complexing agent is simple, fast, accurate, reproducible and practical. It is especially applicable to fast chemical analysis for the free acidity measurement of solutions containing hydrolysable metal ions. The present review gives an overview of the literature which reported categories and appli-cations of complexing agent for the suppression of hydrolysis over the past several decades. Im-portance of complexing agent has been given to free acidity measurement in the presence of hy-drolysable metal ions. According to the actual situation, the application status and the developing prospect of complexing agent is put forward.