Lower Rf Value Research Articles

The internal division of the Pliocene Lillo Formation: correlation between Cone Penetration Tests and lithostratigraphic type sections

The highly fossiliferous Lillo Formation (Pliocene, southern margin North Sea Basin) is formally subdivided in five lithostratigraphical members. While these members are generally relatively easily identifiable in outcrops, they are much more difficultly identifiable in boreholes, hampering geological studies. In the Port of Antwerp area, however, an already existing and dense network of Cone Penetration Tests (CPTs) provides an alternative and additional tool for the recognition of the different lithologies in the Lillo Formation. CPTs reveal a clear geotechnical threefold division of the Formation. The lower and upper intervals, herein named CPT units Li-A and Li-C respectively, are characterized by high qc and low Rf values and correspond to shell-bearing, sandy lithologies. CPT unit Li-A can further be divided in a shelly basal subunit Li-A1 and an overlying sandy subunit Li-A2. CPT units Li-A and Li-C are separated by CPT unit Li-B characterized by low qc and high Rf values which correspond to more clayey lithologies. Four CPTs selected in close vicinity of four well-documented outcrops, some of them being formal stratotypes for the Formation and some of its members, allowed to correlate the geotechnical units with detailed lithological descriptions as well as the formal stratigraphy. CPT unit Li-A1 can be correlated to the Luchtbal Member and the basal part of the Oorderen Member, whereas unit Li-A2 corresponds to the superjacent sandy body of the Oorderen Member. The overlying CPT units Li-B and Li-C seem to correlate differently in different outcrops to the clayey upper part of the Oorderen Member, Kruisschans and Merksem Members. This inconsistency hinders any direct correlation between the geotechnical stratigraphy and lithostratigraphy of the Members of the Lillo Formation. Further research is needed to find the reason(s) for this inconsistency.

Study of quality of life and effectiveness of physical therapy of women after mastectomy in the COVID-19 pandemic conditions

Study of quality of life and effectiveness of physical therapy of women after mastectomy in the COVID-19 pandemic conditions

Integrated supply–demand energy management for optimal design of off-grid hybrid renewable energy systems for residential electrification in arid climates

The growing research interest in hybrid renewable energy systems (HRESs) has been regarded as a natural and yet critical response to address the challenge of rural electrification. Based on a Bibliometric analysis performed by authors, it was concluded that most studies simply adopted supply-side management techniques to perform the design optimization of such a renewable energy system. To further advance those studies, this paper presents a novel approach by integrating demand–supply management (DSM) with particle swarm optimization and applying it to optimally design an off-grid hybrid PV-solar-diesel-battery system for the electrification of residential buildings in arid environments, using a typical dwelling in Adrar, Algeria, as a case study. The proposed HRES is first modelled by an in-house MATLAB code based on a multi-agent system concept and then optimized by minimizing the total net present cost (TNPC), subject to reliability level and renewable energy penetration. After validation against the HOMER software, further techno-economic analyses including sensitivity study are undertaken, considering different battery technologies. By integrating the proposed DSM, the results have shown the following improvements: with RF = 100%, the energy demand and TNPC are reduced by 7% and 18%, respectively, compared to the case of using solely supply-side management. It is found that PV-Li-ion represents the best configuration, with TNPC of $23,427 and cost of energy (COE) of 0.23 $/kWh. However, with lower RF values, the following reductions are achieved: energy consumption (19%) and fuel consumption or CO2 emission (57%), respectively. In contrast, the RF is raised from 15% (without DSM) to 63% (with DSM). It is clear that the optimal configuration consists of wind-diesel, with COE of 0.21 $/kWh, smaller than that obtained with a stand-alone diesel generator system. The outcomes of this work can provide valuable insights into the successful design and deployment of HRES in Algeria and surrounding regions.

Separation of transition and heavy metals using stationary phase gradients and thin layer chromatography

Stationary phase gradients for chelation thin layer chromatography (TLC) have been investigated as a tool to separate a mixture of metal ions. The gradient stationary phases were prepared using controlled rate infusion (CRI) from precursors containing mono-, bi-, and tri-dentate ligands, specifically 3-aminopropyltriethoxysilane, N-[3-(trimethoxysilyl)propyl] ethylenediamine, and N-[3-(trimethoxysilyl)propyl] diethylenetriamine. The presence and the extent of gradient formation were confirmed using N1s X-ray photoelectron spectroscopy (XPS). XPS results showed that the degree of modification was dependent on the aminosilane precursor, its concentration, and the rate of infusion. The separation of four transition and heavy metals (Co2+, Pb2+, Cu2+, and Fe3+) on gradient and uniformly modified plates was compared using a mobile phase containing a stronger chelating agent, ethylenediaminetetraacetic acid (EDTA). The retention of the metal ions was manipulated by varying the surface concentration of the chelating ligands. The order of retention on unmodified plates and on plates modified with a monodentate ligand was Fe3+>Cu2+∼Pb2+∼Co2+, while the order of retention on plates modified with bi- and tri-dentate ligands was Fe3+>Cu2+>Pb2+∼Co2+. Fe3+ and Cu2+ were much more sensitive to the concentration of chelating ligand on the surface (displaying lower Rf values with increasing ligand concentration) than Pb2+ and Co2+. Complete separation was achieved using a high concentration of the tridentate ligand coupled with a longer time for modification, yielding a retention order of Fe3+>Cu2+>Co2+>Pb2+.

Unique thermal behavior of sphingomyelin species with nonhydroxy and 2-hydroxy very-long-chain (C28-C32) PUFAs

In rat germ cells and spermatozoa, sphingomyelin (SM) contains molecular species with nonhydroxy (n) and 2-hydroxy (h) very-long-chain polyunsaturated fatty acids (V), the most abundant being SMs with (n- and h-) 28:4n-6, 30:5n-6, and 32:5n-6 as acyl chains. The aim of this study was to gain information about their thermotropic behavior and interactions with other lipids. After isolation from rat testis, multilamellar and giant unilamellar vesicles from these SMs were examined using fluorescent probes. Only n-32:5 SM and h-32:5 SM displayed a gel-liquid transition temperature (Tt ∼ 21-22°C), the rest remaining in the liquid state in the 5°C-45°C range. The degree of order was larger in bilayers of any of the h-V SMs than in those of their chain-matched n-V SMs. Both, but n-V SM relatively more than h-V SM, decreased the Tt of dimyristoylphosphatidylcholine as their proportion increased in binary phosphatidylcholine:SM liposomes. In contrast to the established ability of 16:0 SM to form lateral cholesterol/SM-rich ordered domains in ternary dioleoylphosphatidylcholine:cholesterol:SM bilayers, neither n-V SM nor h-V SM showed a tendency to do so. Thus, these SMs are in the fluid state and are not involved in this type of domains in spermatozoa at physiological temperatures. However, this state could be altered at the very low temperatures at which these gametes are usually preserved.

Peptidase and esterase activities from mutant strains of Lactobacillus casei

AbstractCell‐free extracts from four Lactose‐negative strains of Lactobacillus casei and their parents were evaluated for peptidase and esterase activity. The four strains showed aminopeptidase (AP), dipeptidase (DP), carboxypeptidase (CP), aryl‐peptidyl amidase (APA) and caseinolytic activities. Very little differences can be noticed between the AP and DP levels of the different strains. On the other hand there were significantly higher CP activities in the Lac(+) strains 64H and ATCC 4646 when compared to the Lac(‐) derivatives. A difference in activity between the Lac(+) and its Lac(‐) derivative was also observed for the APA and caseinolytic activities.Parent and mutant strains of Lactobacillus casei posessed three active AP bands, with RF values of 0.18, 0.21 and 0.31 and one DP band with RF value of 0.25. An additional band (0.32) was detected in strain Lactobacillus casei ATCC 4646 Lac(+) and its mutant.As a general rule the rate of hydrolysis of the p‐nitrophenyl esters of fatty acids for the parent and mutant strains of Lactobacillus casei was higer than that of the o‐nitrophenyl derivatives. All the strains tested exhibited an esterase band with an RF value of 0.3, while only one substrate was hydroysed by the band showing a lower RF value. α‐Naphthyl butyrate was the only substrate hydrolysed by this enzyme in the case of Lactobacillus casei 64H and 11578 while it was α‐naphthyl acetate for ATCC 4646.

Anthocyanins in Camellia polyodonta How, C. semiserrata Chi and C. chekiangoleosa Hu, and Their Phylogenetic Positions in Section Camellia Based on the Pigmentation.

This paper deals with the phylogenies of section Camellia of Chinese origin using a floweranthocyanin as a chemical marker.Wild forms of camellias, C. semiserrata Chi and C. chekiangoleosa Hu, were characterized by the presence of pigments with lower Rf-values on two-dimensional thin layer chromatograms (TLC-plate). Of these pigments, both species contained exclusively or mainly spot 1, a mixture of cyanidin-3-glucoside and 3-galactoside. In addition, the latter C. chekiangoleosa contained a relatively large amount of cyanidin-3-galactoside within spot 1, which is associated with C. japonica subsp. rusticana (Honda) Kitamura, and the former C. semiserrata contained extremely small amount of this pigment.On the other hand, C. polyodonta How contained some individuals with the saluenensisspecific higher Rf pigments together with main lower Rf pigments.From the standpoints of these pigmentations, the manner of pigment-inheritance previously reported and the geographic distribution of the species in and around China, section Camellia may be arranged in the following two phylogenetic sequences; 1) from C. saluenensis Stapf ex Bean or its allied species to C. polyodonta and 2) from C. polyodonta or its primitive forms through C. semiserrata and/or C. chekiangoleosa to the groups of C. japonica Linn.Consequently, as the species extended north-eastwards from the so-called centre of origin, the anthocyanins became chemically simpler, since the genes favouring their production are recessive to those favouring the production of more complex anthocyanins.

Composition of Long Chain Bases in Ceramide of the Guinea Pig Harderian Gland1

Ceramide of the guinea pig Harderian gland was isolated and characterized. The purified ceramide gave two spots on thin-layer chromatography. Ceramide with the higher Rf value (NHCer) contained non-hydroxy fatty acids and that with the lower Rf value (HCer) contained 2-hydroxy fatty acids. The ratio of NHCer to HCer was 6:1. The non-hydroxy fatty acids of NHCer were composed of straight-chain acids (94.9%) and branched-chain acids (5.1%). The 2-hydroxy fatty acids were also composed of straight-chain acids (94.2%) and branched-chain acids (5.8%). The ratio of straight-chain acids to branched-chain acids was similar in NHCer and HCer. The long chain bases of NHCer and HCer consisted of straight chain sphinganines and sphingenines, and methyl-branched long chain bases. In NHCer, 59.9% of the total bases were methyl branched, and in HCer, 48.3%. The characteristics of ceramide, that is, the large amount of methyl-branched long chain bases and relatively small amount of methyl-branched fatty acids, are similar to those of cerebroside and sphingomyelin isolated from the same organ, although the ratios of constituents are different among these sphingolipids.

Endogenous inhibitors in seed ofFraxinus mandshurica Rupr and their effect on germination and regeneration

Bioassay and GC-MS determination indicated that inhibitors of seeds ofFraxinus mandshurica Rupr were distributed mainly in zones of β-inhibitors (including ABA) and of high and low Rf value. The inhibitory activity of outer seed coat of the dormant seed (control treatment) was higher than that of seeds with only the inner coat attached e.g. ABA was 114 and 54ng/g fresh weight respectively. The inhibitory effect of No. 12 zone was even higher than ABA. The inhibitory activity of all the zones decreased after stratification (St) and burying (A0) treatment, especially that of the outer seed coat, whose ABA content decreased to 7(St) and 11 (AO) ng/g(fw). However, the decrease in inhibition of root growth lagged behind the decrease in germination. It is concluded that burial is advantageous to regeneration. Inhibitors of the outer seed coat and seeds were mostly destroyed under the adverse conditions of natural dissemination (Di treatment) indicating that Di was not conducive to regeneration. MS analysis revealed that the largest peaks of No. 6, 7 and 12 zones were linolcic acid, olcic acid and 17-C, 18-C, and 20-C long chain fatty acids. Several coumarins were found in No. 6 and 7 zones, and cadinencs, farnesol and sesquiterpenes were found in No. 6 and 12 zones having common bioorigins with ABA.

Trends in adsorption of end-functionalized polystyrenes by thin-layer chromatography

The thin-layer chromatographic behavior on silica and alumina of polystyrene (PS-H), hydroxyl- terminated polystyrene (PS-OH), and carboxylic acid terminated polystyrene (PS-COOH) as a function of molecular weight is reported. Functionalized samples below a critical molecular weight, which depends on elution solvent, exhibit lower Rf values than PS-H samples of the same molecular weight. Above this value, similar elution behavior is observed. The data describe molecular weight regimes in which and solvent conditions under which functionalized polymers adsorb through specific interaction between the functional group and the surface.

本邦及び台湾省産野生型カメリア節ツバキのアントシアン色素分布の様相

The present investigation was conducted to obtain detailed figures concerning the phylogenies of the genus Camellia belonging to the Section Camellia of Japanese and Formosan origin by the use of petal-anthocyanins as chemical markers.Wild forms of camellias, C. japonica, C. japonica ssp. rusticana, C. japonica ssp. hozanensis and C. japonica f. macrocarpa were characterized by the pigments of lower Rf-values on TLC-plate. Of these pigments, C. japonica ssp. rusticana and C. japonica ssp. hozanensis of Formosan origin contained only spot 1, as compared with C. japonica, C. japonica ssp. hozanensis of Japanese origin and C. japonica f. macrocarpa which contained spots 3, 4 and 5 along with a major spot 1. Furthermore, the former two subspecies contained a relatively large amount of cyanidin 3-galactoside, from 48 to 60% of the amounts of spot 1, and the latter three contained a small amount of this pigment, from 9 to 29%.From these standpoint of the constitution of anthocyanins, it is assumed that these two camellia-groups differed from each other in the processes of phylogenetical differentiation.

Separation of rhenium by thin-layer chromatography with polyethyleneimine cellulose in hydrochloric acid media

The thin-layer chromatographic behavior of 49 inorganic ions on polyethyleneimine (PEI) cellulose has been investigated in hydrochloric acid media (0.01–1.0 mol dm−3). The sorption on the cellulose decreases with increasing acid concentration for most of the ions, but As(III), Ti(IV) and Te(VI) do not exhibit any Rf variation with the acid concentration. The Rf spectra of TI(I), Cd(II), Pb(II) and Zn(II) have a maximum. Ag(I), Bi(III), Nb(V), Ta(V), Mo(VI) and W(VI) are retained tightly on the layer, due to either insoluble salt formation or extensive hydrolysis. The extremely low Rf values of Hg(II), Pd(II), Au(III), Ru(III) and Pt(IV) are accounted for by stability of their chlorocomplexes. Re(VII) distributes chromatographically, having moderate Rf values between 0.3 and 0.6, so that the selective separation of Re(VII) from the other ions is feasible.

Thermostability of acid phosphatase inSelinum vaginatum Clarke andAcer caesium Wall. grown at low and high altitudes

Acid phosphatase isolated from low altitude grown plants of two high altitude plant species,Selinum vaginatum Clarke andAcer caesium Wall, displayed higher thermostability than that from plants of the same species grown at high altitude. The isozyme composition, however, remained unchanged inSelinum vaginatum. InA. caesium, one of four isozymes, was thermolabile in the samples from high altitude and was lost after 10 min heating of the extracts at 60 °c. In the samples from low altitude, this isozyme was not detected and a band with slightly lower Rf value was present which was thermostable. The described changes in the thermal properties of acid phosphatase reflect an adaptive step towards high temperature acclimation at low altitude.

Geometrical Isomerism of Phenylhydrazones of α-Keto Esters. II. p-Substituted Phenylhydrazones of Ethyl Pyruvate and 2,4-Dinitrophenylhydrazones of Some α-Keto Esters

Abstract Each geometrical isomer of various substituted phenylhydrazones of ethyl pyruvate and 2,4-dinitrophenylhydrazones of some α-keto esters was isolated in a pure state. Partial isomerizations of the E-isomers of the former hydrazones to the Z-isomers took place by keeping solutions of the hydrazones in organic solvents containing C, H, and Cl in the dark. An E- or Z-structure was assigned to each molecule on the basis of IR and 1H NMR spectra. In all cases, isomers with higher Rf-values on a silica gel TLC (using benzene as a developing solvent) involved an intramolecular hydrogen bonding between the imino hydrogen and the ester carbonyl oxygen. Thus, the Z-structure was assigned. An E-structure was assigned to other isomers with lower Rf-values. The present assignment is, thus, entirely the same as that proposed in a previous investigation.

Studies on the physiological role of a partially purified small cardioactive neuropeptide ofLymnaea stagnalis

1. The molecular characteristics and physiological role of a partially purified small cardioactive neuropeptide (SCP) of the freshwater pulmonate snailLymnaea stagnalis were studied and compared with those of FMRFamide, an SCP discovered in clam ganglia.Lymnaea SCP, extracted from the central nervous system, and commercial FMRFamide co-elute on Sephadex G-15 columns, but SCP behaves differently from FMRF-amide, when chromatographed on the ion exchanger CM-Sephadex C-25. Moreover, it has a lowerRf value (0.60) on thin layer chromatograms than FMRFamide (0.75). SCP is sensitive to proteolytic enzymes. These data indicate thatLymnaea SCP is a small peptide which is not identical to FMRFamide. 2. Lymnaea SCP is involved in the physiological regulation of the activity of various muscles. It stimulates the frequency of beat as well as the amplitude of the auricle and ventricle. It also stimulates the peristalsis of the oesophagus and causes contractions of the penis retractor muscle. These excitatory effects are similar to those of FMRFamide, suggesting thatLymnaea SCP and FMRFamide must be closely related. 3. The role of SCP as a neurotransmitter is discussed.

Investigations onCroton penduliflorusHutch.: I. Observations on Pharmacognostic, Physicochemical and Pharmacological Characteristics

AbstractIn a preliminary investigation certain pharmacognostic, physicochemical and pharmacological characteristics of Croton penduliflorus were studied to know whether or not the plant merits any serious recognition in scientific pharmacotherapeutics. Extracts of seeds, leaves, stem-bark and root prepared in several solvents were subjected to physicochemical and pharmacological investigations.The extracts showed positive reactions primarily towards tests for alkaloids, sterols and/or terpenoids and for flavonoids. Thin layer chromatography (TLC) of extracts revealed the presence of two major constituents with low and high Rf values. The petroleum ether and alkaline chloroform extracts in particular exerted cholinomimetic effects on isolated guinea pig ileum, rat uterus and frog rectus abdominis muscle. The seed extracts generally exhibited the most pronounced and prolonged cholinomimetic effects.

A Chromatographic Study of the Anthraquinones ofRhamnus alaternusL. III. Extraction, Isolation and Chromatographic Characterization of the Anthraglycosides of the Stem Bark

AbstractSeveral anthraglycosides were isolated from the bark of Rhamnus alaternus L. These had the following Rf values when chromatographed on Whatman no. 1 paper in the solvent system n-propanol, ethyl acetate, water (40:30:30 v/v): G1, 0.98; G2, 0.92; G3, -; G4, 0.79; G5, 0.72; G6, 0.65; G7, 0.61. However, in the TLC system chloroform, ethanol-95%, water (60:30:2 v/v) on silica gel G, G5 was found to be a mixture of G5a and G5b, the latter with the lower Rf value; while G7 separated into G7a, G7b and G7c in descending order of their Rf values. G2, highest in yield, is an emodin glucoside; G4 is an alaternin glucoside; G1 occurs in least amount. G1, G5b, and G6 are diglycosides of emodin, each yielding glucose and rhamnose. G6 hydrolyzes into G2 on TLC in the solvent system methanol, ethyl acetate, water (17:100:13 v/v) on silica gel G. G5a yields physcion, glucose and rhamnose. The total yield of G5 is close to but lower than that of G2. G7 may be a mixture of dianthrone glycosides, yielding on total hy...

A Standardized TLC Analysis of β-Orcinol Depsidones

Many p-orcinol depsidones with low Rf values in the three stan- dardized TLC solvents commonly used in lichenology are better resolved by a solvent system of toluenelethyl acetate/formic acid. Standardized chromatographic data and examples of specific problems resolved by one- and two-dimensional TLC with this solvent system are given. Chemical analyses are reported for 25 lichen species from 17 genera. A vexing problem in the identification of lichen products by thin-layer chromatography (TLC) has been the separation of some 35 low-Rf, p-orcinol compounds many of which are still unknowns. In the three standardized solvent systems (Culberson & Kristinsson 1970; Culberson 1972, 1974; Culberson & Ammann 1979), most of these compounds run below the control substance norstictic acid, which has Rf values between 28 and 40. Even if the spots for these substances were evenly spaced, the Rf values would differ by only about one millimeter. In addition, we now know that these compounds occur in complicated mixtures and consequently accurate identifications will require more sophisticated chro- matographic techniques than those routinely used. Reports in the recent literature of low- Rf compounds (even common ones like salazinic, constictic and connorstictic acids) may be misidentifications based upon insufficient TLC evidence. The purpose of the present paper is to give standardized TLC data for a fourth solvent system (Solvent G) to assist the resolution of difficult mixtures of low-Rf, p-orcinol depsidones by one- and two-dimen- sional TLC. The chromatographic procedure followed the standardized method (Culberson 1972) except that toluene (dried over CaCl2 and redistilled) was used in place of benzene. Solvent G, toluene/ethyl acetate/formic acid (139:83:8, v/v/v; 230 ml), is modified from previously suggested systems (Stahl & Schorn 1961; Hirayama et al. 1976). Formic acid (95-97%) and ethyl acetate were not purified or redistilled; it is not necessary to purify a good grade of toluene for satisfactory results with Solvent G. As with Solvent B, however, a grade of formic acid with low water content is essential. TLC plates were Merck Silica Gel 60 F254 (0.25-mm layer; No. 5765). Chromatographic tanks (Desaga- Heidelberg) were insulated from external temperature fluctuations but were not lined with filter paper. Pre-equilibration of the plates in 60% formic acid (Culberson 1974) did not improve the quality of chromatograms in Solvent G. Unless noted otherwise, the standardized data in Table 1 were from shortened plates (12.5 x 20 cm) developed to 10 cm. Initial spots were 2 cm from the bottom of the plate and 0.5 cm above the solvent. Controls for standardization were included at three positions on every plate. The Rf data in Table 1 are standardized with respect to fumarprotocetraric acid in addition to the usual control substances, atranorin and norstictic acid. Two-dimensional chromatograms were prepared by the standardized method (Culberson & John- son 1976) except that full plates (20 x 20 cm) were used with seven one-dimensional comparisons (including two atranorin-norstictic acid controls) in each direction. In addition, for the second direc- tion, an atranorin-norstictic acid control was added just to the left of the origin on the two-dimensional portion of the plate. This control helps to align spots and to monitor effects of residual first-direction solvent on R, values in the second direction. (In the present report, first- and second-direction solvents

Studies on the metabolites produced by facultative methanol-oxidizing bacteria. Part III. Occurrence of Coenzyme Q12 and Coenzyme Q13 in facultative methanol-oxidizing bacteria.

Pseudomonas C45 is the mutant of facultative methanol-oxidizing bacteria, Pseudomonas N842, and this mutant accumulated CoQ10 and CoQ11, Minor components of CoQ faomologs were studied and four homologs were isolated. Two of them with higher Rf values than that of CoQ10 on the reversed-phase chromatogram were identified as CoQ8 and CoQ9. One CoQ homolog with lower Rf value than that of CoQ11 was purified to crystaline state and identified as CoQ12 by chemical properties and NMR, mass and IR spectrometries. The fourth CoQ homolog with the lowest Rf value was identified as CoQ13, which was novel in nature. CoQ8 through CoQ13 were also detected in similar methanol-oxidizing bacteria by high performance liquid chromatography.

Formation of dimers in the gamma radiolysis of aqueous solutions of pyrimidines and N2O.

Aqueous solutions of pyrimidines (such as uracil and thymine) containing N2O (125 mM) were irradiated with Co-60 gamma rays source and analysed with paper chromatography technique using suitable solvent developing systems. Among the various radiation-induced products, the three different products located with lower Rf values are U. V. absorbing in character. Spectroscopic analysis such as N.M.R., U.V. and mass spectrometry showed tentatively that these products are dimeric compounds; silylation technique assisted for such investigation. These dimers are the major products in the radiolysis of the pyrimidines and N2O system ; uracil produced dimers which constituted 71% of the total uracil loss and thymine 33%.