Measurement of the mass of the tau lepton.
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Journal Article↗
Biomedical subjects
Y Han
Publications and source records attributed to Y Han.
Properties of eye movements induced by activation of neck muscle proprioceptors.
BACKGROUND: We have previously reported that neck muscle vibration can induce visual illusory movements and eye movements under subdued ambient illumination in human subjects with the head and body fixed. The subjects viewed a fixation light with one eye and the other eye was covered. The eye movements were recorded with an infrared system mounted in goggles attached to the head of the subject. METHODS: In order to further examine the properties of these cervico-ocular reactions and reveal any artefacts in the eye movement recordings, we have studied (1) the effect of increasing the ambient light, which made visual illusory movements disappear, (2) the timing between the illusory movement and the eye movement in subdued light, (3) the effect of viewing the target through a pin-hole, which would reveal artefacts due to head movement, and (4) the effect of mounting the eye movement recording system on the head support, which would allow recording to the absolute eye position change. RESULTS: The results of these experiments showed no significant difference from those that were reported previously. Eye movements of about the same amplitude were induced in both eyes under all conditions, and there was no time difference in the occurrence of visual illusory movements and eye movements. CONCLUSION: The results of this study confirm that neck muscle vibration can induce eye position changes. This seems to confirm that the proprioceptive messages originating in the neck muscles are processed together with visual information of eye position in determining gaze direction.
Adult↗
The simultaneous analysis of patient, physician and group practice influences on annual mammography performance.
The current study examined the relationship of several variables at the patient (n = 2780), physician (n = 166), and group practice (n = 45) levels for predicting receipt of annual mammography screening. Patient-level variables included constructs from the Triandis Model of Choice; physician-level variables included measures of barriers and receptivity to prevention, as well as demographic information. Hierarchical modeling demonstrated that variables at the patient and physician level reliably predict annual mammography screening, while frequency of screening did not vary across group practices after accounting for patient and physician variables. Patient-level predictors included social norms, perceived consequences and perceived barriers. The only physician-level predictor identified was annual mammography recommendation. These findings add to data which emphasize the importance of public education and social support in health maintenance activities.
Aged↗
Correlation between lipid plane curvature and lipid chain order.
The 1-palmitoyl-2-oleoyl-phosphatidylethanolamine: 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPE:POPC) system has been investigated by measuring, in the inverted hexagonal (HII) phase, the intercylinder spacings (using x-ray diffraction) and orientational order of the acyl chains (using 2H nuclear magnetic resonance). The presence of 20 wt% dodecane leads to the formation of a HII phase for the composition range from 0 to 39 mol% of POPC in POPE, as ascertained by x-ray diffraction and 2H nuclear magnetic resonance. The addition of the alkane induces a small decrease in chain order, consistent with less stretched chains. An increase in temperature or in POPE proportion leads to a reduction in the intercylinder spacing, primarily due to a decrease in the water core radius. A temperature increase also leads to a reduction in the orientational order of the lipid acyl chains, whereas the POPE proportion has little effect on chain order. A correlation is proposed to relate the radius of curvature of the cylinders in the inverted hexagonal phase to the chain order of the lipids adopting the HII phase. A simple geometrical model is proposed, taking into account the area occupied by the polar headgroup at the interface and the orientational order of the acyl chains reflecting the contribution of the apolar core. From these parameters, intercylinder spacings are calculated that agree well with the values determined experimentally by x-ray diffraction, for the variations of both temperature and POPE:POPC proportion. This model suggests that temperature increases the curvature of lipid layers, mainly by increasing the area subtended by the hydrophobic core through chain conformation disorder, whereas POPC content affects primarily the headgroup interface contribution. The frustration of lipid layer curvature is also shown to be reflected in the acyl chain order measured in the L alpha phase, in the absence of dodecane; for a given temperature, increased order is observed when the curling tendencies of the lipid plane are more pronounced.
Biophysical Phenomena↗
Novel endogenous protein kinase C substrate proteins, neutrinins, in brain synaptic membranes of maturing rat.
A new family of membrane phosphoproteins designated as P9, P12, P15, P16, and P20 with corresponding apparent molecular weights of 9K, 12K, 15K, 16K, and 20K was characterized from rat brain by using in vitro exogenous or endogenous phosphorylation and autoradiography. As the phosphorylation was selectively inhibited by the protein kinase C (PKC) inhibitor PKC19-31 or Ca(2+)-chelating reagents and again stimulated by the PKC activator phorbol 12, 13-dibutyrate, these proteins are thought to be the natural PKC substrates. Because P12, P15, P16, and P20 were neutral proteins (pl 7.0) and specifically distributed in neuronal membranes, the new family of membrane-associated PKC substrate proteins was referred to as neutrinins. Neutrinins were widely distributed in rat brain, being especially plentiful in the spinal cord, medulla oblongata, cerebellum, and midbrain, relatively scanty in the cerebral cortex, but lacking in cytosol of brain areas and cell membrane preparations of peripheral tissues. The expression of the developmental changes of neutrinins has been monitored by the in vitro exogenous phosphorylation approach, i.e., adding purified PKC to a deactivated synaptosomal plasma membrane system. Levels of all the neutrinin proteins in rat cerebral cortex, as represented by P12, P15, and P16, showed an ontogenetic increase from the early postnatal days to the adult. This appears to be correlated with the commencement of synaptogenesis.
Aging↗
Position-dependent protein mutant profile based on mean force field calculation.
The application of the mean force field in protein mutant stability prediction is explored. Based on protein main chain characteristics, including polar fraction, accessibility and dihedral angles, the mean force field was constructed to evaluate the compatibility between an amino acid residue and its environment, from which a position-dependent protein mutant profile was constructed. At each position along a protein sequence, the native residue was replaced by the other 19 types of amino acid residues. The matches were evaluated by energies from mean force field calculation, from which a mutant profile along the protein sequence was derived. General characteristics of such a profile were analyzed. Mutant stabilities for two sets of mutants in two proteins were found to be reasonable compared with experimental data, which indicates that the present method can act as a guide in protein engineering and as an effective scoring matrix in protein sequence-structure alignment studies.
Amino Acid Sequence↗
Factors influencing registered nurses teaching breast self-examination to female clients.
A university hospital-based study was conducted to explore factors that influence nurses teaching breast self-examination (BSE) to female clients, using the PRECEDE (Predisposing, Reinforcing, and Enabling factors in Educational Diagnosis and Evaluation) model as an organizing framework. Female registered nurses (N = 140) from adult inpatient and outpatient units completed a questionnaire that included items about frequency of BSE, knowledge of breast cancer screening and BSE technique, health motivation, confidence and competence in performing BSE, and teaching BSE. Data analysis compared the characteristics of nurses who reported teaching BSE with nurses who did not teach. Nurses in the teaching group had more work experience in nursing and were more likely to have a friend with breast cancer than were those in the nonteaching group. The teaching group had more knowledge about breast cancer screening and BSE technique and reported more confidence and competence in performing BSE.
Adult↗
Differential effects of ethanol on feline rage and predatory attack behavior: an underlying neural mechanism.
Previous studies have shown that, at certain dose levels, ethanol can exert a powerful, facilitatory effect on aggressive behavior in both animals and humans. In the cat, however, it was discovered that ethanol differentially alters two forms of aggression that are common to this species. Defensive rage behavior is significantly enhanced, whereas predatory attack behavior is suppressed by ethanol administration. One possible mechanism governing alcohol's potentiation of defensive rage behavior is that it acts on the descending pathway from the medial hypothalamus to the midbrain periaqueductal gray (PAG)-an essential pathway for the expression of defensive rage behavior that uses excitatory amino acids as a neurotransmitter. This hypothesis is supported by the finding that the excitatory effects of alcohol on defensive rage behavior are blocked by administration of the N-methyl-D-aspartate antagonist alpha-2-amino-7-phosphoheptanoic acid (AP-7) when microinjected into the periaqueductal gray, a primary neuronal target of descending fibers from the medial hypothalamus that mediate the expression of defensive rage behavior. Thus, the present study establishes for the first time a specific component of the neural circuit for defensive rage behavior over which the potentiating effects of ethanol are mediated.
Aggression↗
Protein crystal growth in microgravity using a liquid/liquid diffusion method.
Crystallization of proteins by liquid liquid diffusion method was performed in microgravity using the MDA Minilab aboard the US Space Shuttle. Three proteins, namely lysozyme, trichosanthin, and a new lechin, were crystallized in the space experiment. In contrast to the results of space experiments with a tube-like vapor diffusion method, the crystallization conditions for growing better crystals in space are remarkably different from the conditions optimized on earth. This may be due to difficulties in ground optimization, which are caused by gravity-dependent phenomena, in particular the specific convective flow occurring with liquid liquid diffusion.
Biotechnology↗
A method of estimating infant deaths in Korea.
"The goal of this project was to develop a new method for estimating infant deaths in [South] Korea. An attempt was made to collect information on real infant death cases by using...medical insurance benefit data and by conducting a medical facilities survey, which allows us to [trace] back the fate of the births from the delivery. Another strategy employed was the gathering of information on infant deaths from the various existing sources and integrating them into one set after adjusting for overlapping cases among the sources." (SUMMARY IN KOR)
Asia↗
[Effect of the T4 on the viscera and embryo of perinatal mice].
58 Female Kun Ming mice of perinatal stage (from the 15th day of pregnacy to the 21th day after birth) were fed with Tripcholorolide (T4) isolated from multiglycosides of Tripterygium wilfordii (GTW) at a doze of 0.6 mg/kg for group 1 or 0.3 mg/kg for group 2 per day for 4 weeks. Lactation was decreased in some females and some F1 off spring died. The succinic dehydrogenase (SDH) activity of the mice liver were increased due to the destruction of its mitocondian. Liver cells degenerated and glycogen decreased. Distal tubules of kidney degenerated. Heart and spleen were normal. T4 was also fed to 10 female mice from the 5th to 17th day of pregnacy. However, neither the absorbed fetus nor dead fetus increased.
Animals↗
[Analysis of obstructive dystocia due to cervical adhesion caused by gonococcal infection].
OBJECTIVE: To analyse the clinical manifestation and treatment of obstructive dystocia due to cervical adhesion. METHOD: Ten cases of obstructive dystocia due to cervical adhesion were retrospectively analysed. RESULTS: Gram's stain of the cervical smear was positive for gonococci in all of the 10 patients. Sites of the cervical adhesion were at external os in 5 cases, at internal os in 2 cases and in cervical canal in the other 3. The clinical manifestation varied with the site of the cervical adhesion. All the patients had spontaneous delivery after separating the adhesions. CONCLUSION: As one of the factors of high-risk pregnancy, obstructive dystocia due to cervical adhesion caused by gonococcal infection should be considered seriously by the obstetricians.
Adolescent↗
Relieving cancerous pain and improving the survival quality with fei ai chong ji.
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Adult↗
[Clinical application of gamma nail in the treatment of the intertrochanteric fractures].
We retrospectively studied the clinical application of modified Gamma nail (GN). Based on the measurement of intramedullary canal of the femur by wax model. We modified GN in the following aspects: the diameter of GN was changed from 17 mm to 14 mm in the proximal end and from 13 mm to 10 mm in the distal end and the angle between the two ends was also modified from 11 to 5-6; the modified compression screws represented self-compression property; the long GN was designed and developed. We applied GN in 31 cases, and 28 with an average postoperative duration of 20 months were followed up. The final results revealed that the fracture healing rate was 93%. No crutch ambulance reached 86% and excellent hip movement reached 82%. The partial or complete weight bearing was allowed 9-11 days postoperatively. We consider GN an effective means for the treatment of type II and type III of intertrochanteric fracture of the femur.
Adult↗
Direct measurement of the Ds branching fraction to phi pi.
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Journal Article↗
Model of human chorionic gonadotropin and lutropin receptor interaction that explains signal transduction of the glycoprotein hormones.
The goal of these studies was to devise a model that explains how human chorionic gonadotropin (hCG) interacts with lutropin (LH) receptors to elicit a hormone signal. Here we show that alpha-subunit residues near the N terminus, the exposed surface of the cysteine knot, and portions of the first and third loops most distant from the beta-subunit interface were recognized by antibodies that bound to hCG-receptor complexes. These observations were combined with similar data obtained for the beta-subunit (Cosowsky, L., Rao, S.N.V., Macdonald, G.J., Papkoff, H., Campbell, R.K., and Moyle, W.R. (1995) J. Biol. Chem. 270, 20011-20019), information on residues of hCG that can be changed without disrupting hormone function, the crystal structure of deglycosylated hCG, and the crystal structure of a leucine-repeat protein to devise a model of hCG-receptor interaction. This model suggest that the extracellular domain of the LH receptor is "U-" or "J"-shaped and makes several contacts with the transmembrane domain. High affinity hormone binding results from interactions between residues in the curved portion of the extracellular domain of the receptor and the groove in the hormone formed by the apposition of the second alpha-subunit loop and the first and third beta-subunit loops. Most of the remainder of the hormone is found in the large space between the arms of the extracellular domain and makes few, if any, additional specific contacts with the receptor needed for high affinity binding. Signal transduction is caused by steric or other influences of the hormone on the distance between the arms of the extracellular domain, an effect augmented by the oligosaccharides. Because the extracellular domain is coupled at multiple sites to the transmembrane domain, the change in conformation of the extracellular domain is relayed to the transmembrane domain and subsequently to the cytoplasmic surface of the plasma membrane. While the model does not require the hormone to contact the transmembrane domain to initiate signal transduction, small portions of both subunits may be near the transmembrane domain and assist in initiating the hormonal signal. This is the first model that is consistent with all known information on the activity of the gonadotropins including the amounts of the hormone that are exposed in the hormone-receptor complex, the apparent lack of specific contacts between much of the hormone and the receptor, and the roles of the oligosaccharides in signal transduction.(ABSTRACT TRUNCATED AT 400 WORDS)
Amino Acid Sequence↗
Direct measurement of the pseudoscalar decay constant, fDs.
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Journal Article↗
A new protein folding recognition potential function.
On the study of protein inverse folding problem, one goal is to find simple and efficient potential to evaluate the compatibility between structure and a given sequence. We present here a novo empirical mean force potential to address the importance of electrostatic interactions in protein inverse folding study. It is based on protein main chain polar fraction and constructed in a way similar with Sippl's from a database of 64 known independent three-dimensional protein structures. This potential was applied to recognize the protein native conformations among a conformation pool. Calculated results show that this potential is powerful in picking out native conformations, in addition it can also find structure similarity between proteins with low sequence similarity. The success of this new potential clearly shows the importance of electrostatic factors in protein inverse folding studies.
Electrochemistry↗