Rotational isomeric state treatment of the cystine residue. Configuration partition function and its relationship to the optical activity exhibited by the disulfide bond.
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Cystine↗
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Results for “Optical Rotation”
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Rotating photonic crystals: a medium for compact optical gyroscopes.
The effect of rotation of a photonic crystal that contains a set of microcavities is studied using the formulation of electrodynamics in rotating media. A new manifestation of the Sagnac effect is observed. It is shown that the phase shift or frequency difference between rotation-codirected and rotation-counterdirected propagations depends on a set of parameters not previously reported. The use of the new configuration for designing compact optical gyroscopes is studied and discussed.
Journal Article↗
Much ado about mirrors.
Takano (1998) has suggested four different kinds of reversal to explain why mirrors reverse left and right and not up and down or back and front. In fact, mirrors perform only one kind of reversal: They simply reverse about their own planes, and reflection about one plane is equivalent to reflection about any other, plus a translocation and rotation. The reflection of an object is termed its enantiomorph. Perception of the enantiomorphic relation normally requires an act, either physical or mental, of alignment. In deciding whether two objects are enantiomorphs, there is a tendency to align them so that the reversal is about the axis of least asymmetry. But in deciding whether a single object is one of two possible enantiomorphic forms, people generally rotate it to some canonical orientation. In the case of objects with defined top-bottom, back-front, and left-right axes, the canonical orientation is determined by the top-bottom and back-front axes, leaving the left-right axis to carry the reversal. The main reason for this, I suggest, is that the top-bottom and back-front axes have functional priority, and the left-right axis cannot be defined until top-bottom and back-front are established. This means that the latter two axes have priority in establishing the canonical orientation. The left-right axis is usually, but not always, the axis of least asymmetry.
Humans↗
Millimeter-wave-detected, millimeter-wave optical polarization spectroscopy.
We report a new form of microwave optical double-resonance spectroscopy called millimeter-wave-detected, millimeter-wave optical polarization spectroscopy (mmOPS). In contrast to other forms of polarization spectroscopy, in which the polarization rotation of optical beams is detected, the mmOPS technique is based on the polarization rotation of millimeter waves induced by the anisotropy from optical pumping out of the lower or upper levels of the millimeter wave transition. By monitoring ground-state rotational transitions with the millimeter waves, the mmOPS technique is capable of identifying weak or otherwise difficult-to-observe optical transitions in complex chemical environments, where multiple molecular species or vibrational states can lead to spectral congestion. Once a transition is identified, mmOPS can then be used to record pure rotational transitions in vibrationally and electronically excited states, with the resolution limited only by the radiative decay rate. Here, the sensitivity of this nearly-background-free technique is demonstrated by optically pumping the weak, nominally spin-forbidden CS e (3)Sigma(-)-X (1)Sigma(+) (2-0) and d (3)Delta-X (1)Sigma(+) (6-0) electronic transitions while probing the CS X (1)Sigma(+) (v(")=0,J(")=2-1) rotational transition with millimeter waves. The J(')=2,N(')=2<--J(')=1,N(')=1 pure rotational transition of the CS e (3)Sigma(-) (v(')=2) state is then recorded by optically preparing the J(')=1,N(')=1 level of the e (3)Sigma(-) (v(')=2) state via the J(')=1,N(')=1<--J(")=1 transition of the e (3)Sigma(-)-X (1)Sigma(+) (2-0) band.
Journal Article↗
Rotational temperature of nitrogen glow discharge obtained by optical emission spectroscopy.
Measurements of rotational temperature as low as several hundred Kelvin have been measured using optical emission spectroscopy (OES) in nitrogen direct current (DC) glow discharge. The strongest band of the first negative system of nitrogen was chosen to deduce the rotational temperature at four different positions in nitrogen DC glow discharge, the back of cathode; cathode sheath; positive column; and anode glow. In positive column the rotational temperature increased apparently with the increasing discharge voltage from 500 to 1000 V when the pressure was 10 Pa. But with pressure of 20 Pa the rotational temperature in positive column increased slightly with the increase of discharge voltage. On the contrary, the rotational temperature in cathode sheath took reverse tendencies when the discharge voltage varies from 500 to 1000 V. As regard the anode glow, the rotational temperature at 10 Pa decreased with the increase of discharge voltage, but that at pressure of 20 Pa increased. We attribute the different tendencies of the rotational temperature to the different discharge statues at different pressures. When the discharge voltage varies from 500 to 1100 V, the discharge with pressure of 10 Pa is normal glow and that with 20 Pa is abnormal glow.
Nitrogen↗
[Measurement of rotational temperature in N2 DC glow discharge by optical emission spectroscopy].
Measurements of rotational temperature as low as several hundred Kelvin have been achieved using optical emission spectroscopy (OES) in nitrogen DC glow discharge. The strongest band of the first negative system of nitrogen molecule ion was chosen to determine the rotational temperature of nitrogen DC glow discharge at 4 different positions in the discharge area: back of the cathode; cathode sheath; positive column and anode glow region. In positive column the rotational temperature of N2+ increases apparently with the increasing discharge voltage from 500-1,100 V when the pressure is 10 Pa. However at pressure of 20 Pa the rotational temperature in positive column increases slightly with the increase of discharge voltage. On the contrary, the rotational temperature in cathode sheath takes reverse tendency when the discharge voltage varies from 500-1,100 V. As regard the anode glow region, the rotational temperature at 10 Pa decreases with the increase of discharge voltage, but that at the 20 Pa increases. We attribute the different changing tendencies of the rotational temperature to the different discharge status at different pressure. When the discharge voltage varies from 500 to 1,100 V, the discharge at pressure of 10 Pa is normal glow and that at 20 Pa is abnormal glow.
Electricity↗
In vivo endoscopic optical coherence tomography by use of a rotational microelectromechanical system probe.
A novel endoscopic optical coherence tomography probe was designed and constructed with a 1.9-mm microelectromechanical system (MEMS) motor. The new MEMS endoscopic probe design eliminates the need to couple the rotational energy from the proximal to the distal end of the probe. Furthermore, the endoscopic probe's sheath and fiber have the advantages of having a much smaller diameter and being more flexible than traditional endoscopes since no reinforcement is needed to couple the rotational torque. At the distal end, a prism mounted on a micromotor deflects the light rays to create a transverse circular-scanning pathway. Because our MEMS scanner does not require the coupling of a rotational single-mode fiber, a high scanning speed is possible while eliminating unstable optical signals caused by nonuniform coupling.
Anatomy, Cross-Sectional↗
Optic nerve injury after sudden traumatic rotation of the eye. A case report.
Optic nerve injury is regularly accompanied by signs of local facial or ocular injury, fractures or unconsciousness. The energy of the blow is thought to be delivered to the optic nerve directly by stretching and tearing and by shock wave forces and secondarily as sequelae of contusion. A case is described in which optic nerve injury is caused by a sudden traumatic duction of the eyeball, with all signs of local or systemic contusion missing. During observation the primarily healthy optic nerve head developed subtotal optic atrophy. This case strengthens the belief that the optic nerve is particularly vulnerable to stretching, tearing and torsion.
Blindness↗
Silicone and poly(methyl methacrylate) lens decentration associated with asymmetric capsule shrinkage in rabbits.
PURPOSE: To determine whether silicone intraocular lenses (IOLs) are readily affected by capsule shrinkage. SETTING: Department of Ophthalmology, Wakayama Medical College, Wakayama, Japan. METHODS: A D-shaped incision was made in the anterior capsule of 38 eyes of 20 white rabbits. One of 2 IOL types was implanted in the capsular bag: 3-piece silicone or single-piece all-poly(methyl methacrylate) (PMMA). Twenty-eight eyes were evaluated for IOL rotation and optic decentration. RESULTS: The extent of postoperative decentration and rotation observed with the silicone IOLs did not significantly exceed that of the PMMA IOLs. CONCLUSIONS: Our results, coupled with the advantages of small incision surgery, indicate that a silicone IOL is an effective choice.
Animals↗
90% pump depletion and good beam quality in a pulse-injection-seeded nanosecond optical parametric oscillator.
We measured 90% pump depletion in a singly resonant image-rotating nanosecond optical parametric oscillator that was pulse-injection seeded by a self-generated signal pulse. The oscillator was pumped by an 8 ns duration single-frequency 532 nm pulse from an injection-seeded Q-switched Nd:YAG laser and resonated an 803 nm signal. The pump and pulsed-seed beams had flat-topped spatial fluence profiles with diameters of approximately 6 mm, giving a cavity Fresnel number at 803 nm approaching 400. The beam cleanup effects of the image-rotating cavity produce a far-field signal spatial fluence profile with approximately 60% of its energy falling within the diffraction-limited spot size.
Journal Article↗
Faecal assay for 203Pb by the sample rotation method.
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Feces↗
Optic nerve avulsion due to forced rotation of the globe by a snooker cue.
We report a case of partial avulsion of the optic nerve caused by sudden rotation of the globe due to a snooker cue injury. Minimal direct ocular trauma occurred. This case supports the belief that sudden rotation of the globe is the major mechanism of optic nerve avulsion. We include the first results of ultrasound examination that demonstrate optic nerve injury in such a case and believe that, in conjunction with fluorescein angiography and computerised tomography, it is important in the full evaluation of such cases.
Adult↗
Self-rotation of red blood cells in optical tweezers: prospects for high throughput malaria diagnosis.
A simple and sensitive approach for detection of malarial parasite in blood samples is demonstrated. The approach exploits our finding that, in hypertonic buffer, a normal red blood cell (RBC) rotates by itself when trapped by an optical tweezers. The rotational speed increases linearly at lower trap-beam powers and more rapidly at higher powers. In contrast, under the same experimental conditions, RBC having a malarial parasite does not rotate. The rotational speeds of other RBCs from malaria-infected sample are of an order of magnitude less than that for normal RBC and also increase much more slowly with an increase in trap beam power than that for normal RBC. The difference in rotational speeds could be exploited for the diagnosis of malaria.
Animals↗
Retinal topography in the optic tract of adult goldfish.
The present study was aimed at determining how transformations in fiber order establish a retinal topography in the optic tract of adult Carassius auratus. Horseradish peroxidase was applied to the optic nerve or retina, and the pathways of labeled axons originating from retinal annuli or wedges were analysed in reconstructed serial-sections and wholeamounts of the optic pathway. The age-related fiber order of the optic tract involves a rotation of the optic pathway that begins near the chiasm, continues through the optic tract as it wraps around the brain, and extends through the brachia. The relative order of laminae, in which each lamina is composed of age-related axons, is maintained in the optic pathway. The laminae add systematically onto the optic tract in a mediolateral direction with the oldest lamina forming the medial margin. Retinal sector order in the optic tract is established by the rearrangement of axons from each lamina. These rearrangements begin at the chiasm and, in part, involve transposition of axons originating from the ventrotemporal and dorsonasal sectors of the retina. The transformations achieve a fiber order in the optic tract that is appropriate for entry into the tectum. It is proposed that the final retinal topography of the optic tract is determined by the combined influences of selective affinities along the neural axis and substrate guidance mechanisms, the latter being mediated largely by the oldest axons of the fasciculus medialis tractus opticus.
Animals↗
Some perceptual effects generated by rotating graftings.
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Differential Threshold↗
Disruption of optic fibre growth following eye rotation in Xenopus laevis embryos.
Eye rotation is an experimental paradigm used to study axial specification of the amphibian retina and its connections to the tectum. Jacobson reported that the naso-temporal and dorso-ventral axes are determined sequentially and independently between Nieuwkoop-Faber (NF) stages 28 and 32 in Xenopus. Others claim however, that both retinal axes are determined much earlier and not independently in Xenopus and Rana. We now find that in Xenopus this operation can disturb the exit of optic fibres from the retina with the severity of disruption depending on the time of surgery. Eyes rotated 180 degrees at NF stage 26-27, before any fibres develop, form aberrant retinal fascicle patterns in which the first optic fibres to differentiate (pioneer fibres), failing to exit from the eye, are deflected into circling instead of radial trajectories. Optic fibres appearing later follow these early misguided axons, creating circular bundles. Eyes rotated later (NF 32-34), after optic fibres differentiate, develop normal but inverted patterns because radial fascicles in the retina at the time of operation accurately guide all newly arising fibres to the optic nerve head. This stage-dependent sensitivity of retinal fascicle development must be considered when interpreting the results of rotation experiments.
Age Factors↗
Stable rotating dipole solitons in nonlocal optical media.
We reveal that nonlocality can provide a simple physical mechanism for stabilization of multihump optical solitons and present what we believe to be the first example of stable rotating dipole solitons and soliton spiraling, which are known to be unstable in all types of realistic nonlinear media with a local response.
Journal Article↗
Eye rotations with change of accommodation.
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Accommodation, Ocular↗