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PubMed1998

The effect of timing and spatial separation on the velocity of auditory apparent motion.

Previously, it was shown that the minimum conditions for the illusion of auditory apparent motion (AAM) depend on stimulus timing but not spatial separation. In the present experiment, the effects of stimulus timing and source separation on the perceived velocity of AAM were examined. Eight listeners estimated the velocity, duration, and distance traveled of AAM, using a no-modulus, magnitude estimation procedure. Four burst durations (25, 50, 100, and 300 msec), 10 stimulus onset asynchronies (SOAs; 30, 40, 50, 60, 70, 80, 90, 100, 110, and 120 msec) and two separations (10 degrees and 40 degrees) were tested. Perceived velocity estimates were related to the total duration (burst duration + SOA) of the stimulus sequence. The effect of separation on velocity was extremely small but statistically significant. These results are similar to those obtained previously on the minimum conditions for AAM. Duration estimates were related only to total duration, but separation estimates were related to both separation and total duration. These results suggest that velocity is possibly a primary dimension of AAM that is independent of source separation.

Acceleration↗
PubMed1976

Distribution of microtubules during centriole separation in rat kangaroo (Potorous) cells.

The distribution of microtubule profiles during separation of the centriole duplexes in prophase of rat kangaroo cells (PTK2W) has been investigated by serial section reconstructions. Separation begins with a reduction of the interphase microtubular network which radiates from the region of the duplex to all parts of the cell. As duplexes separate, microtubular elements appear between the duplexes. However, most microtubular elements extend oblique to the axis of separation rather than aligned along the axis of separation. Few microtubules are seen extending directly between duplexes. Longer profiles are seen as separation continues. Prior to the completion of separation, microtubules coalesce to form a discrete band often juxtaposed on the nuclear membrane. Subsequently, the duplexes reach their final position and nuclear envelope dissolution is initiated.

Cell Line↗
PubMed1999

Application of Free-flow Electrophoresis to the Separation of Murine Lymphocytes.

Free-flow electrophoresis offers not only the all-in-solution separation process but also very gentle separation conditions, and it can be used for continuous separation and preparation, so it has been widely applied in the fields of biochemistry and cell biology. Using this technique to separate insoluble particles such as cells, both high separation efficiency and high activity and viability could be obtained. Murine lymphocytes were separated in low ionic strength triethanolamine buffer by free-flow electrophoresis, the cell fractions were detected and characterized by means of UV spectrometry, immune fluorescence labeling and flow cytometry. Results indicated that T and B lymphocytes were well separated with high viability.

Journal Article↗
PubMed2004

[The efficacy of two type of membrane plasma separator on the treatment of patients with chronic severe hepatitis B].

OBJECTIVE: In order to compare the efficacy of two kinds of membrane plasma separator on the treatment of patients with severe hepatitis B. METHODS: 63 cases suffering from chronic severe hepatitis B were divided into two groups, 25 cases were treated with plasma exchange using Evacure-4A membrane plasma separator (A group) or 38 cases were using PS-06 membrane plasma separator (B group). Both of them also were treated with similar basic medical treatment. The level of serum total bilirubin, non-conjugated bilirubin, prothrombin time and albumin were tested at baseline and the end of the treatment with PE. RESULTS: Evacure-4A and PS-06 membrane plasma separators can effientively remove bilirubin, the levels of serum total bilirubin, non-conjugated bilirubin of all patients were significantly decreased after treated with PE. In A group, the level of serum total bilirubin, non-conjugated bilirubin decreased from (464.2+/-193.8)micromol/L to (279.4+/-158.7)micromol/L, (293.5+/-129.1)micromol/L to (175.5+/-106.7)micromol/L (t=5.45, 10.36, P<0.01) respectively. In B group, the level of serum total bilirubin, non-conjugated bilirubin decreased from (493.2+/-126.9)micromol/L to (299.7+/-96.5)micromol/L, (300.2+/-74.3)micromol/L to (171.5+/-53.1)micromol/L (t=5.17, 12.04, P<0.01) respectively. The level of serum albumin increased after treated with PE in A and B groups, to contrast with PS-06, the increasing percentage of albumin was higher when the patients were treated with PE using Evacure-4A membrane plasma separator [(8.3+/-0.7) % vs. (3.4+/-9.3) %, t = 2.76, P<0.01]. CONCLUSION: Evacure-4A membrane plasma separator may be better than PS-06 membrane plasma separator on the treatment of patients with chronic severe hepatitis B.

Adult↗
PubMed2004

Simultaneous separation of anions and cations by capillary electrophoresis with high magnitude, reversed electroosmotic flow.

A method for simultaneous separation and indirect detection of anions and cations by capillary electrophoresis (CE) is reported. An anodic electroosmotic flow (EOF) in excess of -100 x 10(-9) m2 V(-1) s(-1) was achieved by the addition of 0.1 mM didodecyldimethylammonium bromide (DDAB) to the background electrolyte (BGE). This high magnitude EOF enabled rapid co-EOF separation of inorganic anions and counter-EOF separation of inorganic cations having high electrophoretic mobilities. Single-end injection of the sample at the capillary inlet and detection near the capillary outlet was used. Indirect photometric detection of cations was accomplished using a cationic probe (imidazole), with counter-ionic (Kohlrausch) indirect detection being used for anions. A mixture consisting of chloride, bromide, nitrate, lithium, magnesium, sodium, calcium, potassium, and ammonium was separated in less than 3.5 min using a background electrolyte comprising 6 mM imidazole, 12 mM hydroxyisobutyric acid, 0.1 mM DDAB, 2 mM 18-crown-6 at pH 4.0, with indirect detection at 210 nm. The system was well suited to the separation and detection of inorganic cations, with limits of detection (LODs) in the range 0.92-4.65 microM and separation efficiencies from 44,400-208,5000 theoretical plates. By contrast, LODs for inorganic anions ranged from 6.66 to 11.43 microM, with separation efficiencies of 2500-26,300. Analytical potential of the method is discussed.

Anions↗
PubMed2005

[Separation and identification of metallothionein isoforms and sub-isoforms by liquid chromatography].

A method has been established for the separation and identification of metallothionein (MT) isoforms and sub-isoforms by liquid chromatography. A mixture of rabbit liver MT was separated on a DEAE A-25 weak anion-exchange chromatographic (AEC) column. Inductively coupled plasma-mass spectrometer (ICP-MS) was used for off-line detection of Zn in each fraction. The two main MT isoforms, MT-1 and MT-2, were isolated. The collected MT isoform fractions were then desalted by a homemade Sephadex G-25 size exclusion chromatographic (SEC) column. Afterwards, the sample was separated on a C18 reversed-phase column with UV detection at 210 nm. Different separation conditions were discussed and several sub-isoforms of MT were well separated at pH 2.0. The sub-isoforms were finally characterized by on-line HPLC-ESI-MS. The isoforms and sub-isoforms were well separated on a reversed-phase column under optimized chromatographic conditions and the detection results of ESI-MS were in agreement with the data found in literature. The method developed can be well used for the separation of metallothionein isoforms and sub-isoforms.

Animals↗
PubMed1992

T-cell responses of leprosy patients and healthy contacts toward separated protein antigens of Mycobacterium leprae.

Sonicated extracts of Mycobacterium leprae were separated by two-dimensional gel electrophoresis and electroeluted into 400 distinct soluble fractions. These fractions were probed with T lymphocytes from leprosy patients of different disease types, healthy contacts, and unexposed healthy individuals. Proliferative responses were visualized using three-dimensional stimulation profiles. T cells from many patients and contacts responded to a multitude of antigen fractions of different molecular masses and isoelectric points. T cells from unexposed individuals gave significant responses to lysates or whole organisms of M. leprae, but no or only marginal responses to separated antigen fractions. T cells of polar tuberculoid (TT) and the majority of polar lepromatous (LL) leprosy patients responded only to separated antigen fractions but not to lysates or whole organisms of M. leprae. The remaining LL patients were totally unresponsive and even failed to respond to separated M. leprae fractions. Thus, in some leprosy patients unresponsiveness to M. leprae seems to be caused by distinct components and can be broken by using separated antigen fractions; whereas in others, anergy remains. T cells of borderline tuberculoid (BT) patients, who were under chemotherapy, responded to separated antigen fractions as well as to lysates of M. leprae organisms. In contrast, BT patients who were untreated failed to react with any of the M. leprae preparations. Similarly, T cells of the majority of LL patients responding to separated fractions were under chemotherapy; whereas T cells from untreated LL patients gave no or only marginal responses to any of the M. leprae antigen preparations. These findings suggest some linkage between the degree of T-cell responsiveness and antileprosy drug treatment.

Antigens, Bacterial↗
PubMed2002

[Preparation of molecularly imprinted chiral monolithic column and its applications for separation of diastereomers].

A cinchonine imprinted chiral monolithic column was prepared for the separation of the diastereomers of cinchonine and cinchonidine by in-situ molecular imprinting technique. This type of molecularly imprinted column can be prepared only by a single-step procedure. In order to improve the selectivity and efficiency, a new in-situ molecular imprinting polymerization system was introduced by adopting porogenic solvents of toluene and 1-dodecanol with relatively low polarity and appropriate ratios of polymerization mixture. Diastereomers of cinchonine and cinchonidine were fully separated both under isocratic and gradient elutions on the chiral monolithic column. The broad peak shown in isocratic elution could be improved in gradient elution. Effects of mobile phase composition, flow rate and temperature on retention and separation factor were investigated. Due to the large throughput pores in the chiral monolithic column, low backpressure was observed during the separation process and a separation factor of 3.18 was obtained at 1.0 mL/min. The increase of temperature could improve the separation factor and a maximum separation factor of 5.40 was obtained at 60 degrees C.

English Abstract↗
PubMed2005

Morphological study on the megakaryocytes with nuclear extrusion and nucleocytoplasmic separation in four cases.

To investigate the morphological changes of megakaryocytes with nuclear extrusion and nucleocytoplasmic separation, the morphological characteristics of megakaryocytes in peripheral blood films, bone marrow smears, and bone marrow biopsies from 4 newly diagnosed patients with primary myelofibrosis (PMF), myelodysplastic syndrome (MDS), myeloblastic leukemia with maturation (M(2)) and erythroleukemia (M(6)) were studied by using light microscope. The results showed that many kinds of dysmegakaryocytes were observed in bone marrow smears of 4 cases, while in case A (PMF) and case D (M(6)) micromegakaryocytes were ripped apart; in case B (MDS) and case C (M(2)) megakaryocytes were accompanied by nuclear extrusion or nucleocytoplasmic separation, and their bodies were large or giant, the part of nucleus separated from their body and little cytoplasm remained as micromegakaryocytes. The nucleocytoplasmic separation could be displayed by immunocytochemistry stain. It is concluded that the phenomenon of nuclear extrusion and nucleocytoplasmic separation in megakaryocytes suggested the process that dispersed multinuclear releasing towards surround or even totally left the cell body during the megakaryocyte maturation. It also showed that the micromegakaryocytes may be the result of nucleocytoplasmic separation or splittings from multi-separated nucleus.

Aged↗
PubMed2006

The characteristics of separation-individuation in Turkish High School students.

The aim of the present study was examine the characteristics of separation-individuation in Turkish high school students and to investigate the contribution of sociodemographic variables on this second individuation process of adolescence. The sample consisted of 618 adolescents between the ages of 14 and 18 in three urban and two rural high schools (338 females and 280 males). Measures used included a demographic questionnaire and the Separation-Individuation Test of Adolescence (SITA), developed by Levin, Green, and Millon (1986). Results indicated that the 16-year-old group had significantly higher mean scores on the Engulfment Anxiety, Dependency Denial, and Rejection Expectancy subscales than the 15-year-old group. Males had significantly higher scores on the Practicing-Mirroring subscale than girls. Tenth graders had significantly higher mean scores on the Practicing-Mirroring, Nurturance Seeking, Peer Enmeshment, Teacher Enmeshment, and Healthy Separation subscales but the mean scores on the Dependency Denial and Engulfment Anxiety subscales decreased. The means scores on the Practicing-Mirroring, Dependency, Denial, Separation Anxiety, Teacher Enmeshment, and Rejection Expectancy subscales were significantly different among the socioeconomic status groups. Also, rural adolescents can be distinguished from urban counterparts by their increased tendency to perceive themselves as self-centered, to experience separation anxiety, to seek close interpersonal ties with caretakers, teachers, and peers, and by an integration of needs for dependence and independence. The general pattern of results investigating the separation-individuation development of Turkish adolescents suggested that compared with individualistic Western cultures, Turkish culture stressed the importance of connection as well as separation and psychic restructuring and interpersonal relatedness changes leading to an autonomous self within relational contexts.

Adolescent↗
PubMed2006

Operative treatment for separation of distal tibiofibular syndesmosis.

OBJECTIVE: To study the influence of separation of distal tibiofibular syndesmosis on ankle joint and to compare various operative methods so as to find suitable stabilization for separated distal tibiofibular syndesmosis. METHODS: From July 1997 to July 2002, we treated 87 patients (64 males and 23 females, aged 18-54 years) with separation of distal tibiofibular syndesmosis, among whom, 79 were combined with fracture of malleolus. Manipulative reduction, internal fixation with cancellous screws and external fixation with plaster support were performed on 37 patients, fixation with plate and screws for fibular fracture and fixation with cancellous screws for distal tibiofibular syndesmosis on 34 patients, and repair of the distal tibiofibular ligaments with tendon of peroneus longus, reduction of the separated distal tibiofibular syndesmosis, and fixation with cancellous screws on 16 patients. The ankle joint had been dorsiflexed for 30 degrees when the distal tibiofibular syndesmosis was fixed with cancellous screws. And the cancellous screws were taken out at 8-10 weeks after operation. RESULTS: These patients were followed up for at least two years. The curative effects were assessed according to the complaints of the patients and the contour, function and radiogram of the ankle joint: excellent in 55 patients (63%), good in 18 patients (21%), and fair in 14 patients (16%). Separation of distal tibiofibular syndesmosis recurred in 2 patients, who underwent a reoperation for repairing the distal tibiofibular ligaments with tendon of peroneus longus and recovered. One cancellous screw was broken off. No necrosis developed in the anterior skin of the ankle mortise. CONCLUSIONS: Separation of distal tibiofibular syndesmosis can be treated with various reasonable operations. Repair with tendon of the peroneus longus can get excellent outcomes for complete separation of the distal tibiofibular syndesmosis.

Adolescent↗
PubMed1987

Indicators and designs in genetic epidemiology: separating heredity and environment.

The problems of separating highly confounded hereditary and environmental factors are reviewed from an epidemiological point of view. Once the fact rather than the appearance of familial aggregation is established, one can search for and analyze strong indicators of either genetic or environmental effects, and ultimately attempt their separation by strong design. Indicators of genetic effects are classified according to the presence or absence of family recurrence. In the presence of family recurrence, three analytic approaches are available: segregation analysis, linkage, and heritability estimates. In the absence of family recurrence, biological markers and endogamous groups can be used. Indicators of environmental effects are also classified according to the presence or absence of family recurrence of a disorder. In the presence of family recurrence, three environmental indicators are considered: non-Mendelian clustering, such as time of onset versus age in family clusters, and sex clusters; cohabitational effects; and maternal transmission. In the absence of family recurrence, environmental indicators include secular trends, migration, time and place clusters, family size, and birth order. Designs that aim to separate heredity and environment include twin studies, fixed clusters that include a variety of degrees of relatedness (particularly the family set-design), and comparisons of separately reared relatives. The strengths and weaknesses of twin studies and family set designs are reviewed. Separately reared relatives provide the most cogent tests of genetic and environmental hypotheses. Among these, separated twin pairs, half-sibs, and relatives separated through institutional placement or adoption are considered. Adoption strategies are illustrated by the Danish adoption studies of schizophrenia, criminality, and alcoholism, and these studies are reanalyzed from the perspective of epidemiological case-control and cohort studies. Finally, the potential uses of multiple family settings as they occur in the general population are briefly discussed.

Environment↗
PubMedDate not supplied

Separating heredity and environment.

The problems of separating highly confounded heredity and environmental factors are reviewed from an epidemiological point of view. Once the fact rather than the appearance of familial aggregation is established, one can search for and analyze strong indicators of either genetic or environmental effects, and ultimately attempt their separation by strong design. Indicators of genetic effects are classified according to the presence or absence of family recurrence. In the presence of family recurrence, three analytic approaches are available: segregation analysis, linkage, and heritability estimates. In the absence of family recurrence, biological markers and endogamous groups can be used. Indicators of environmental effects are also classified according to the presence or absence of family recurrence of a disorder. In the presence of family recurrence, three environmental indicators are considered: non-Mendelian clustering, such as time of onset versus age in family clusters, and sex clusters; cohabitational effects; and maternal transmission. In the absence of family recurrence, environmental indicators include secular trends, migration, time and place clusters, family size, and birth order. Designs that aim to separate heredity and environment include twin studies, fixed clusters that include a variety of degrees of relatedness (particularly the family set-design), and comparisons of separately reared relatives. The strengths and weaknesses of twin studies and family set designs are reviewed. Separately reared relatives provide the most cogent tests of genetic and environmental hypotheses. Among these, separated twin pairs, half-sibs, and relatives separated through institutional placement or adoption are considered. Adoption strategies are illustrated by the Danish adoption studies of schizophrenia, criminality, and alcoholism, and these studies are reanalyzed from the perspective of epidemiological case-control and cohort studies. Finally, the potential uses of multiple family settings as they occur in the general population are briefly considered.

Diseases in Twins↗
PubMed1984

Separation of neutral lipids and free fatty acids by high-performance liquid chromatography using low wavelength ultraviolet detection.

Normal phase, isocratic high-performance liquid chromatography methods are described for the separation of neutral lipid and fatty acid classes using low wavelength detection. Prior to high-performance liquid chromatography, methods were developed and are described for the separation of phospholipids from neutral lipids and fatty acids using small (600 mg) silica Sep-PaksTM. Recoveries of cholesteryl esters, triglycerides, fatty acids, and phospholipids from the silica columns were greater than 95%. Two mobile phases are described for lipid class separation by high-performance liquid chromatography. The first mobile phase, hexane-2-propanol-acetic acid 100:0.5:01, resulted in incomplete separation of cholesteryl ester and triglyceride but excellent separations of fatty acids and cholesterol. The second mobile phase, hexane-n-butyl chloride-acetonitrile-acetic acid 90:10:1.5:0.01, resulted in complete separation of the four lipid classes. This mobile phase also separated individual triglycerides and fatty acids based on the number of double bonds. Recoveries of radiolabeled lipids for the four lipid classes from high-performance liquid chromatography was greater than 95% with both mobile phases.

Animals↗
PubMed1983

[Separation of the left atrium from the right pulmonary artery in the suprasternal echocardiogram: a parameter of left atrial pressure].

A separation of the left atrium from the right pulmonary artery during atrial contraction may be observed in the suprasternal echocardiogram. In 280 catheterized patients with sinus rhythm, we investigated whether left atrial separation is a parameter from which an estimate of the left atrial pressure can be obtained. In 239 of the 280 patients, the suprasternal echograms were of a quality such that it could be seen whether there was, a left atrial separation. In 182 patients, a normal left atrial pressure (greater than or equal to 12 mm Hg) was found; in 57 patients, the left atrial pressure was elevated. An atrial separation was observed in 183 patients, and in 56 patients it was lacking. Lack of left atrial separation indicates a left atrial pressure elevation with a sensitivity of 73.7% and a specificity of 92.3%. If a left atrial pressure above 18 mm Hg was considered elevated, the sensitivity of this echoparameter amounted to 90.3%, and the specificity was 86.5%. The study shows that the left atrial separation from the right pulmonary artery separation from the right pulmonary artery in the suprasternal echocardiogram is a parameter valuable in providing a rough estimate of the left atrial pressure.

Blood Pressure↗
PubMed1993

The effect of early separation from the mother on pups in bonding to humans and pup health.

The separation of young dogs from their mother at the age of 6 weeks had a negative effect on the physical condition and weight gain of separated pups compared to that of pups with maternal contact till 12 weeks. Disease susceptibility and mortality was higher in pups with a shorter maternal contact period. These factors were related to behavioural measurements of separation stress. However, early separation had no significant advantage to socialisation with humans, provided that separated and nonseparated pups had daily human contact. Early separation therefore did not improve dog/human bonding processes but lowered condition and increased mortality in separated pups.

Animals↗
PubMedDate not supplied

[Separation of recombinant proteins by chromatography on vesicular sorbents].

Vesicle chromatography, a recently developed method for separation of biomolecules, uses the vesicular packing (VP) material (clusters of microcapsules derived from plant cells), which was tested with respect to its application for the recombinant protein separation. Since VP has a well-defined separation limit, biomolecules are distributed in two separate peaks: large molecules are excluded and small molecules permeate through cell walls into the empty cell lumen. Recombinant proteins frequently form oligomers, which differ from monomers not only in size but also chemically and biologically. In the present study, separations of the recombinant proinsulin fusion protein oligomer and monomer, the recombinant human gamma-interferon monomer and dimer and recombinant tumour necrosis factor-alpha were investigated. For peak identification, the fractions and starting samples of the recombinant proteins were analysed by HPLC. The separations occurred without any sorption effects and with high efficiency and resolution of the protein peaks at a short column (10 cm). The VP is characterised by a high load ability, which favours the scale-up purification of the recombinant proteins. The combination of VP and HPLC is a considerable advance in biotechnology separation.

Chromatography, High Pressure Liquid↗
PubMed1994

Separation of subfractions of the hydrophobic components of calf lung surfactant.

This study reports the biochemical separation of the hydrophobic constituents of calf lung surfactant into separate fractions from which specific components are excluded. Gel permeation chromatography on LH-20 with acidified chloroform-methanol separated the constituents of calf lung surfactant extract (CLSE) into fractions containing purified phospholipids (PPL), the neutral lipids and phospholipids (N&PL), or the hydrophobic surfactant proteins (SP)-B and -C together with the phospholipids (SP&PL). Extraction of acid to prevent phospholipid degradation after separation reduced recovery of the apoproteins in SP&PL. This fraction was therefore supplemented with protein purified separately to attain the initial levels present in CLSE. Biochemical analyses confirmed that the resulting preparations had the expected composition not only of protein, neutral lipids and phospholipids, but also of the phospholipid head groups. In addition to these fractions obtained with acidified solvent, elution of CLSE with chloroform-methanol without acid yielded the zwitterionic phospholipids substantially depleted of anionic phosphatidylglycerol and phosphatidylinositol. Limited interfacial measurements also demonstrated that the process of separation did not alter the fundamental surface characteristics of the surfactant constituents. Recombined CLSE (rCLSE) reconstituted from all of the separated components had surface activity indistinguishable from the original CLSE. The individual fractions of surfactant components also had average molecular areas at the air-liquid interface which agreed with predictions based on their biochemical composition. These well defined preparations of the hydrophobic constituents of pulmonary surfactant provide the basis for future studies to establish the role of individual components in the function of this complex surface active material.

Animals↗