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PubMed2005

[Separation of 3-substituted-(R,S)-beta-alanine derivatives by high performance liquid chromatography].

3-Substituted-(R,S)-beta-alanines derivatized by 1-fluoro-2,4-dinitro-5-L-valinamide (Marfey's reagent) were successfully separated by reversed-phase high performance liquid chromatography. The separations were performed with gradient elution. The mobile phase A was acetonitrile containing 0.1% (v/v) trifluoroacetic acid and the mobile phase B was 0.1% (v/v) trifluoroacetic acid aqueous solution. Thirty-two pairs of 3-substituted-(R,S)-beta-alanine derivatives, phenyl, substituted phenyl, naphthyl, substituted pyridyl and thienyl, were separated. The mobile phase A content was changed from 35% to 75% in 20 min. All (R-L)-diastereomers were eluted prior to the (S-L) ones. Substituents with larger hydrophobic parameters (pi) gave longer retention times (tR) for their derivatives than those with smaller ones except for 3-hydroxyphenyl and 4-hydroxyphenyl substituents. The positioning of the substituents on benzene ring of beta-alanines (beta-Ala) also influenced tR and separation. 4-Subsituted-phenyl-(R,S)-beta-Ala derivatives gave longer tR and better separation than 2-substituted isomers. The enantiomer excess values of R- and S-beta-Ala were also determined.

Chromatography, High Pressure Liquid↗

PubMed2005

[Study on extraction of coumarins in Cnidium monieri by supercritical CO2 and separation of compositions analysis].

OBJECTIVE: To analyze the chemical constituents of supercritical carbon dioxide extraction products from Cnidium monieri. METHOD: Four-factor and three-level orthogonal experimental design was used to optimize the SFE conditions as guided by the content of total coumarins in the extract. The chemical constituents were separated and identified by recrystalization. RESULT: Optimum extraction process was established: 25 MPa as extraction pressure, 50 degrees C as extraction temperature, 6.5 MPa as separation pressure and 60 degrees C as separation temperature. CONCLUSION: Changes in extraction pressure, temperature, time, pulverized degree and separation pressure affect the extracting results remarkably. The two kinds of chemical constituents were separated by recrystallization from C. monieri and identified by the methods of UV, IR, MS, NMR.

Chromatography, Supercritical Fluid↗

PubMed1991

Alternative mobile phases for enhanced chromatographic selectivity and increased sensitivity in peptide separations.

The standard method for separating peptide mixtures is reversed-phase high-performance liquid chromatography with gradients of increasing concentrations of acetonitrile in the presence of trifluoroacetic acid. With modern instruments and columns, complex peptide mixtures can be separated, and low picomole amounts can be collected in tens of microliters. Difficult separations are addressed by modifying the gradient slope or organic eluant composition. Further improvements in resolution are often needed, requiring fundamental changes in mobile phase composition or selection of complementary chromatographic separation mechanisms. For the present study, tryptic digests of cytochrome c from various species were separated in the presence of dilute hydrochloric acid by reversed phase on a Waters Delta-PakTM C18 high-performance insert column and by strong cation exchange on a Waters Protein-PakTM SP 8HR. Different and enhanced reversed-phase selectivity was obtained by replacing trifluoroacetic acid with dilute hydrochloric acid at the same pH. The increased optical clarity of hydrochloric acid-based mobile phases in the low ultraviolet wavelengths yielded increased sensitivity. Very different selectivity was observed with the cation-exchange chromatography. These data expand the options for peptide mapping by providing additional selectivity combined with increased mass sensitivity and spectral information in the low ultraviolet.

Amino Acid Sequence↗

PubMed2006

The effect of topical application of human milk, ethyl alcohol 96%, and silver sulfadiazine on umbilical cord separation time in newborn infants.

BACKGROUND: Several agents have been used for neonatal umbilical cord care, but we did not find any study evaluating the effect of human milk on umbilical cord separation time. The purpose of this study was to compare the effect of topical application of human milk, ethyl alcohol 96%, and silver sulfadiazine on umbilical cord separation time in newborn infants. This study was undertaken place at a primary-level newborn nursery at a university teaching hospital and a private hospital. Of 373 singleton near- to full-term newborns enrolled in the study, 312 completed the study. METHODS: Newborns from birth were randomized to either: 1) mother's milk group, 2) alcohol group, 3) silver sulfadiazine group, and 4) control (no treatment) group. Mother's milk for group 1, ethyl alcohol for group 2, and silver sulfadiazine ointment for group 3 were applied to the umbilical stump three hours after birth and continued every eight hours until two days after umbilical cord separation. The time to umbilical cord separation and any discomfort such as infection, hemorrhage, and granuloma formation were reported by mothers. Nothing was applied to the umbilical stump of the control group and they received dry cord care only. RESULTS: It was observed a significant difference in the mean cord separation time among the four group. No significant complications were observed in any group. CONCLUSION: Breast milk could be substituted for other topical agents for umbilical cord care, but a multicenter study is required in order to advise it for routine umbilical cord care.

Administration, Cutaneous↗

PubMed2006

[Clinical application and processing of separate movable partial denture].

OBJECTIVE: This report is to introduce the processing method of the separate movable partial denture and get an initial clinical evaluation. METHODS: The separate movable partial denture was developed as a kind of special design in utilizing double base plate to separately get support for bearing stress and get the stability of retention. RESULTS: The clinical application indicated that the separate movable partial denture has effective function of common movable partial denture as well as has a good function of natural human teeth protection, especially for those patients with I -II tooth loose. CONCLUSION: The separate movable partial denture is the ideal choice of treatment for those patients who are suffering I - II teeth loose. This type of movable partial denture was considered effectively protect natural human teeth and extend the lifetime of natural tooth long-term and further observation in clinical care on this type of denture is needed.

Dental Abutments↗

PubMed1990

Separation of platelet concentrates (PC) from buffy coat (BC) using the bottom and top drainage (BAT) system.

By the preparation of platelet concentrates (PC) from buffy coat (BC), the blood component separation may be improved considerably. One can use new bag systems with bottom and top drainage (BAT) which allow partial automation of the separation procedure. Thus, it is possible to produce very pure red cell concentrates (RCC) and FFP, as well as BC, by one separation step under well standardized conditions. Several preparative factors influence the quality of the PCs, especially the storage of the whole blood and the BC. Optimal yields (0.72-0.78 x 10(11) platelets), separation efficiency (67.7-70.8%) and lowest cell contamination (leukocytes 0.1-0.2 x 10(8), red cells 0.2-0.3 x 10(8) per concentrate) were obtained with whole blood stored for 1 h and BC for 2-4 h before resuspension by 30 min face-over-face-rotation. In respect to the release of leukocyte proteases during the storage, the BC should not rest for more than 2-3 h before separation of the platelets in order to prevent potentially functional impairment of the platelets by leukocyte proteases.

Blood Component Removal↗

PubMed2006

[Studies on characteristics of absorption and separation of traditional Chinese medicine compound prescription by macroporous resin].

OBJECTIVE: Study the characteristics of absorption and separation of traditional Chinese medicine compound prescription using macroporous resin. METHOD: Study the techniquecs and characteristics of absorption and separation of a sample by macroporous resin, which is composed of coptis root, rhubarb and common anemarrhena rhizome, containing alkaloid, anthraquinone and saponin. RESULT: It is proved by qualitative and quantitative researches studies that after absorbed and separated by optimized technics process, most prime effective components or section fractions in traditional Chinese medicine compound prescription can be reserved maintained. CONCLUSION: If the techniquecs of separation is properly designed, the same kind of macropore resin can absorbd and separate various effective components or section in traditional Chinese medicine compound prescription which have with different chemical structures efficiently.

Alkaloids↗

PubMed2006

[Study of the follow-up by the general practitioner of the children of separated parents].

In Belgium, on 10 millions of inhabitants, there are more than 31.000 divorces per year and we estimate that 600.000 children are experiencing separation of their parents. The general practitioner (GP) have inevitably the responsability of the medical follow-up of some of these children. The possible professional implications related to these young patients, concerning the GP have never been the subject of a study so far. Consequently the aim of this research was to reveal what is happening in the daily practice of the family practitioner related with the children of separete parents. There were some hypothesis notably about particular working conditions for the GP in connection with possible consequences for these children and possible necessity of special professional attitudes. A qualitative research in focus group was organized with GPs in order to get an interaction between the participants and to go past the concepts supposed before the study. Therefore between September and December 04, 8 focus groups of 10-18 generalist practitioners were set up in Brussels and Mons. Each meeting was axed around couples separated for less than 3 years and children between 0 and 15 years. Finally, 120 GPs discussed about 242 cases of divorces from their practice. The debates totally typed word by word were analysed with assistance of the software QSR N5. The point of view of the GPs is: 1) A divorce affects the working conditions of the general practitioner, for example the parcelling out of the medical follow-up of the child and the fact " of being used" by the family. 2) The conflict between the parents after the separation increases the difficulties for the GP in his daily practice. 3) The parental's separation influences the choice of professional attitudes of the GP, notably vis-a-vis the conflict (for instance to try or not to try the conflict's management). 4) Mainly in conflict situation, parental divorce is a risk for the child; psychological or behavioural disorders, physical health problems, school difficulties, ... 5) Certain professional attitudes of the general practitioner can influence positively the evolution of these children, for example to speak to the two parents. 6) Some professional actions aggravate the situation of the these children, for instance to product certain official written documents (attestations, reports, certificats, ...) in a conflicts context. In conclusion, this study desmonstrates that parental separation affects the medical follow-up of the children by the GPs and that professional attitudes influences positively or negatively the child's evolution. For the first time, some negative consequences of the divorce on children are described in the first line. All this results must be confirmed by quantitative research work.

Adolescent↗

PubMed1991

Strangers in a strange land: a psychobiological study of infant monkeys before and after separation from real or inanimate mothers.

Some rhesus monkey (Macaca mulatta) infants have a "despair" or depression-like response to mother-infant separation, while others do not. The presumed interrelation between early rearing conditions and the neurobiological status of the infant that might lead to increased risk for despair is not understood. In this study, the characteristics of the "mother" were controlled by rearing infant rhesus monkeys with their biological mothers, or with inanimate mothers. Behavioral data were collected before and after separation at 6-7 months of age. The neurobiological status of the infants was evaluated by measuring the concentration of norepinephrine, its major metabolite, and the metabolites of dopamine and serotonin in cerebrospinal fluid. The results suggest that despair is not simply a behavioral response to separation. Instead, despair may reflect the inability to cope with the separation environment. Coping with the separation environment appears to depend on neurobiological and behavioral characteristics of the infant that are related to, if not determined by, characteristics of the mother.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1991

Cell separation system studied by mixed culture of single wild strain with tetrads-forming mutant strain of Micrococcus luteus.

Mixed culture study of singly occurring wild strain IFO 3333 of Micrococcus luteus and a tetrads-forming mutant strain MT, in the absence or presence of trypsin, supported our previous assumption that at least two kinds of separation systems were involved in cell separation of M. luteus, the one having a physiological role in cutting off the outermost layer of the cell wall (separation system-Om) and the other in cutting off the inner layer of the "proper" cell wall or the septum (separation system-In). The separation system-Om of IFO 3333 insensitive to trypsin substituted, freely from the cells, for that of MT sensitive to trypsin.

Micrococcus luteus↗

PubMedDate not supplied

Alternative mobile phases for enhanced chromatographic selectivity and increased sensitivity in peptide separations.

The standard method for separating peptide mixtures is reversed-phase high-performance liquid chromatography with gradients of increasing concentrations of acetonitrile in the presence of trifluoroacetic acid. With modern instruments and columns, complex peptide mixtures can be separated, and low picomole amounts can be collected in tens of microliters. Difficult separations are addressed by modifying the gradient slope or organic eluant composition. Further improvements in resolution are often needed, requiring fundamental changes in mobile phase composition or selection of complementary chromatographic separation mechanisms. For the present study, tryptic digests of cytochrome c from various species were separated in the presence of dilute hydrochloric acid by reversed phase on a Waters Delta-Pak C18 high-performance insert column and by strong cation exchange on a Waters Protein-Pak SP 8HR. Different and enhanced reversed-phase selectivity was obtained by replacing trifluoroacetic acid with dilute hydrochloric acid at the same pH. The increased optical clarity of hydrochloric acid-based mobile phases in the low ultraviolet wavelengths yielded increased sensitivity. Very different selectivity was observed with the cation-exchange chromatography. These data expand the options for peptide mapping by providing additional selectivity combined with increased mass sensitivity and spectral information in the low ultraviolet.

Amino Acid Sequence↗

PubMed1989

Use of sodium-chloride separated human skin in detection of circulating anti-basement membrane zone antibodies.

The sensitivity of the indirect immunofluorescence (IIF) technique for detection of circulating basement membrane zone (BMZ) antibodies was evaluated, employing NaCl-separated human skin and intact skin as substrate. Consecutive serum samples from 12 patients with clinically, histologically and immunohistologically verified bullous pemphigoid (BP) were investigated in parallel on both substrates, in dilutions ranging from 1:10 to 1:1,280. All BP sera showed linear deposits of IgG at the BMZ on intact skin, with titres ranging from 10 to 160. On NaCl-separated skin, all BP sera produced a linear epidermal fluorescent band for IgG, with titres ranging from 80 to 1,280. None of the sera showed deposits of IgM anti-BMZ antibodies. Sera from 5 healthy donors (dilutions 1:10) produced no fluorescence, either on intact or on NaCl-separated skin. The serum-titres of circulating anti-BMZ IgG antibodies in 2 patients with corticosteroid-resistant BP were significantly reduced (from 160 to less than 10) during treatment with plasmapheresis, when using NaCl-separated skin as substrate for IIF, whereas the serum-titres showed insignificant reduction (from 20 to less than 10), when using intact skin as substrate. We conclude that the IIF method is more sensitive for detection of circulating anti-BMZ antibodies, when NaCl-separated skin as compared with intact human skin is employed as substrate.

Antibodies↗

PubMed1989

[Use of the isoradial chamber in the preparation of thrombocyte concentrates using the Travenol CS-3000 separator].

During intensive treatment of haemoblastoses it is important to administer repeatedly high-quality platelet concentrates. The authors describe the first results obtained with the use of an isoradial chamber of Travenol Co. for separation on a CS-3000 separator. Using the chamber, they achieved in the first 20 patients a reduction of the separation time by 30 mins. (23%) and the thrombocyte yield was not reduced. The resulting product contained, however, more leucocytes. The chamber can be used to reduce the separation period also under Czechoslovak conditions where donors have smaller numbers of thrombocytes than reported by western authors (the microcomputer of the separator is set for a regime suited for larger thrombocyte numbers).

Blood Component Removal↗

PubMed1987

Psychological factors capable of preventing the inhibition of antibody responses in separated infant monkeys.

The capacity of infant squirrel monkeys to mount an antibody response to viral challenge was evaluated after removal from their mothers in several social and physical environments. Control and separated infants were injected with a benign virus, the bacteriophage X174, and levels of neutralizing antibody were assessed for 3 weeks. Infants separated alone in an unfamiliar environment showed a significant reduction in antibody levels as compared to control infants. Allowing infants to remain in the home environment, either alone or with peers, prevented this inhibition of antibody responses from occurring. Similarly, providing familiar peers in the novel environment facilitated the normal expression of antibody responses. These results indicate that the trauma of maternal separation is significantly reduced when infants are familiar with the separation environment or familiar social companions are available. The reduced antibody response was associated with the highest level of adrenal activation induced by the unfamiliar separation condition, but antibody titers and plasma cortisol levels could not be specifically correlated in individual infants.

Animals↗

PubMed1988

[A study of the cardiotocograms recorded by a separated 1MHz ultrasound transducer].

Fetal heart rate records were obtained in 12 antepartum and 13 intrapartum cases, with an ultrasonic Doppler transducer with five separated crystals and a conventional transducer. The loss of the FHR record due to increased noise in 30 minutes before delivery ranged from 1.1 to 23.2% (6.4 +/- 6.5%) in the separate type transducer, and it was 0.6 to 29.9% (10.5 +/- 7.6%) in the conventional one. During the 5 minutes before delivery, it was 3.3 to 58.0% (20.2 +/- 18.5%) in the separate type, and 3.3 to 70.0% (31.6 +/- 19.5%) in the conventional one. Clearer FHR records were obtained with the use of the separate type than the conventional one (p less than 0.05). Noise was mostly recorded in the 5 minutes before delivery. In the NST, the loss of the FHR record due to maternal posture change decreased when the new transducer (p less than 0.05) was used. The loss was 0 to 56.7% (14.9 +/- 18.2%) with the new type, and 2.0 to 100% (42.9 +/- 36.4%) with the conventional one for the maternal posture which showed the worst record. By using the separate type transducer, maternal posture need not to be limited in the NST, and the somatic and mental discomfort is less than when the conventional one is used.

Female↗

PubMed1987

Primate models of separation-induced depression.

Nonhuman primates have been shown to demonstrate behavioral and physiologic reactions to social separation that suggest symptoms of clinical depression. Although care must be taken in the use of animal models of psychopathology, it can be argued that in the case of certain affective disorders, including depression, nonhuman primate response to separation meets the criteria for validity. A variety of social, environmental, and genetic factors can influence the separation response in terms of intensity and specific types of symptomatology, and through the use of experimental manipulations, the relative importance of these and other variables in mediating depressive reactions have been studied. The effects of catecholamine depleting drugs (such as AMPT) as well as therapeutic agents on separation-induced depression in monkeys are being studied in an effort to determine underlying mechanisms of depression and particularly how neurochemical factors may interact synergistically with environmental and psychosocial factors in determining severity and nature of depressive reactions to separation.

Animals↗

PubMed1988

Analytic and preparative separation of apolipoproteins A-I, A-II, and A-IV by reverse phase high pressure liquid chromatography.

We have developed a rapid reverse phase high pressure liquid chromatographic technique capable of separating apolipoproteins A-I, A-II, and A-IV and their constituent isoforms. The separations were performed on a 30 cm x 3.9 mm C18 reverse-phase silica-based column (Waters Associates) using a 47-55% gradient of acetonitrile in 0.1% trifluoroacetic acid. Injection of a mixture of equal weights of apolipoproteins A-I, A-II, and A-IV yielded a single peak for apoA-IV, two peaks of apoA-I isoforms, and three peaks of apoA-II isoforms, with negligible overlap of each peak. When applied to the isolation of apoA-IV from a crude protein mixture obtained by incubation of phospholipid-triglyceride emulsion particles with lipoprotein-depleted plasma, the technique yielded a single peak of highly pure apoA-IV cleanly separated from isoforms of apoA-I and higher molecular weight proteins. A positive linear correlation was observed between apoprotein hydrophobicity and column retention time, thus indicating that the system provided a true reverse phase separation. We conclude that reverse phase high pressure liquid chromatography can separate human apolipoprotein A-IV from isoforms of apoA-I and apoA-II on the basis of differences in mean molecular hydrophobicity. The technique has direct application to the isolation of human apolipoprotein A-IV.

Apolipoprotein A-I↗

PubMed1988

[Hygienic aspects of pig's head meat. 2. Mechanical separation of pigs' heads].

Deboning pigs' heads is a labour-intensive process. According to information supplied by the industry, mechanical separation of pigs' heads offers good prospects. Data on the hygienic implications of this process were not known. These were studied more closely in an experimental design. The bacteriological and sensory qualities as well as the chemical and histological composition of the product were compared with those of manually obtained pig's head meat. In addition, the yield of the process of separation was determined. Three groups of heads were mechanically separated, viz. untreated heads and heads which had previously been dipped in water having an initial temperature of 100 degrees C for one minute and five minutes respectively. These studies served to verify the fact that mechanical separation of pigs' heads is technically possible. Previous dipping of the heads in water at a temperature of 100 degrees C produced a considerable improvement of the yield in meat, which was due to setting of the rind. The chemical composition of the product was roughly identical with that of manually obtained head meat. However, tissue composition and structure of the tissues differed markedly. An important drawback is the higher count of Enterobacteriaceae in the product. These bacteria are probably released on compression from sites which are difficult of access such as the nose, the pharyngeal cavity and the alveoli. In addition, they may be possibly protected by a covering layer of mucus. Therefore, mechanical separation is not regarded as acceptable from the point of view of hygiene.

Animals↗

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