Enhanced photon generation in a Nb/n-InGaAs/p-InP superconductor/semiconductor-diode light emitting device.

We experimentally demonstrate Cooper pairs' drastic enhancement of the band-to-band radiative recombination rate in a semiconductor. Electron Cooper pairs injected from a superconducting electrode into an active layer by the proximity effect recombine with holes injected from a p-type electrode. The recombination of a Cooper pair with p-type carriers dramatically increases the photon generation probability of a light-emitting diode in the optical-fiber communication band. The measured radiative decay time rapidly decreases with decreasing temperature below the superconducting transition temperature of the niobium electrodes. Our results indicate the possibility to open up new interdisciplinary fields between superconductivity and optoelectronics.

Characterization of two-photon polarization mixed states generated from entangled-classical hybrid photon source.

We experimentally prepare bi-photon mixed states in polarization employing an entangled-classical hybrid photon emitter which can properly model solid-state entangled photon sources with uncorrelated background photons. Polarization-uncorrelated photon pairs in totally mixed (TM) states are embodied with classical thermal radiation, while the polarization-entangled ones in a Bell state are generated by conventional parametric down conversion. The bi-photon states generated from the hybrid photon emitter are characterized in terms of a linear entropy-tangle plane, which reveals the formation of two-qubit Werner states. We also propose a direct way for evaluating the Werner states by means of minimal coincidence counts measurements. This simple method can be widely applicable in examining the bi-photon states from solid-state entangled photon sources, in which the polarization-entangled photon pairs have temporal correlation while the background photons in the TM states do not.

Specification of thermosensory neuron fate in C. elegans requires ttx-1, a homolog of otd/Otx.

Temperature is a critical modulator of animal metabolism and behavior, yet the mechanisms underlying the development and function of thermosensory neurons are poorly understood. C. elegans senses temperature using the AFD thermosensory neurons. Mutations in the gene ttx-1 affect AFD neuron function. Here, we show that ttx-1 regulates all differentiated characteristics of the AFD neurons. ttx-1 mutants are defective in a thermotactic behavior and exhibit deregulated thermosensory inputs into a neuroendocrine signaling pathway. ttx-1 encodes a member of the conserved OTD/OTX homeodomain protein family and is expressed in the AFD neurons. Misexpression of ttx-1 converts other sensory neurons to an AFD-like fate. Our results extend a previously noted conservation of developmental mechanisms between the thermosensory circuit in C. elegans and the vertebrate photosensory circuit, suggesting an evolutionary link between thermosensation and phototransduction.

Ca2+ signaling via the neuronal calcium sensor-1 regulates associative learning and memory in C. elegans.

On a radial temperature gradient, C. elegans worms migrate, after conditioning with food, toward their cultivation temperature and move along this isotherm. This experience-dependent behavior is called isothermal tracking (IT). Here we show that the neuron-specific calcium sensor-1 (NCS-1) is essential for optimal IT. ncs-1 knockout animals show major defects in IT behavior, although their chemotactic, locomotor, and thermal avoidance behaviors are normal. The knockout phenotype can be rescued by reintroducing wild-type NCS-1 into the AIY interneuron, a key component of the thermotaxis network. A loss-of-function form of NCS-1 incapable of binding calcium does not restore IT, whereas NCS-1 overexpression enhances IT performance levels, accelerates learning (faster acquisition), and produces a memory with slower extinction. Thus, proper calcium signaling via NCS-1 defines a novel pathway essential for associative learning and memory.

A fluoroimmunoassay based on immunoliposomes containing genetically engineered lipid-tagged antibody.

Immunoliposomes were prepared by using biosynthetically lipid-tagged anti-2-phenyloxazolone single-chain antibody. Carboxyfluorescein as a fluorescent marker was encapsulated in the immunoliposomes. Some conditions for fluoroimmunoassay using the immunoliposomes were optimized by binding assays with hapten-coated microtiter wells. A competitive fluoroimmunoassay for the caproic acid conjugate of 2-phenyloxazolone as a model antigen was performed with the immunoliposomes. In the optimized assay conditions, antigen could be determined in the concentration range from 10(-7) to 10(-9) M.

Design and synthesis of sodium ion-selective ionophores based on 16-crown-5 derivatives for an ion-selective electrode.

To develop an ionophore that is highly selective for sodium for use in an ion-selective electrode, we propose a model based on 16-crown-5 which has a cavity just the size of Na(+ )and has a "block" subunit to prevent complex formation with ions larger than Na(+). Based on this molecular model, eight kinds of 16-crown-5 derivatives have been synthesized, and their structural ion selectivity has been evaluated in detail. The 16-crown-5 derivatives having two bulky "block" subunits showed high Na(+) selectivity relative to K(+). In particular, the derivative with two decalino subunits (DD16C5) exhibited the highest Na(+) selectivity of all the ionophores examined. When a phosphate ester-type membrane plasticizer, tris(ethylhexyl) phosphate, was used as the membrane solvent for the ion-sensing membrane based on poly(vinyl chloride), the electrode using DD16C5 exhibited a Na(+) selectivity of over 1000 times relative to alkali metal and alkaline earth metal ions, including K(+), which is the most serious interferant. The evaluation of the relationship between the ionophore chemical structures and the ion-selective features contributes to the host-guest chemistry to give a highly selective ionophore for an alkali metal ion.

[A long-term study on dentofacial changes after sagittal splitting osteotomies in skeletal Class III malocclusions].

The purpose of this study is to clarify the long-term dentofacial changes after sagittal splitting ramus osteotomy in skeletal Class III patients, and to study the factors involved to find its countermeasures. For this purpose we used the radiographic cephalograms in 16 patients (13 females and 3 males) observed for more than five years after surgery. We measured the postoperative changes in the position of Pogonion and the inclination of maxillary and mandibular incisors. The results were as follows: 1. Pogonion was retruded 9.3 mm on the average by surgery. In the period from the removal of intermaxillary fixation to one year postoperatively Pogonion slipped forwardly and upwardly (average; anteriorly 1.0 mm, superiorly 0.8 mm). In the period from one year postoperatively to the time of the final observation Pogonion slipped to a downward direction. 2. No correlation was found between the amounts of vertical displacement by surgery and postoperative vertical changes of Pogonion. On the other hand, a high correlation was found between the amounts of mandibular setback and the forward displacement of Pogonion. 3. Mandibular incisors were tipped labially by preoperative orthodontic treatments, then maxillary and mandibular incisors moved lingually during intermaxillary fixation. After release of intermaxillary fixation, maxillary incisors moved labially in a small distance. After one year maxillary incisors were inclined slightly in the lingual direction. It is obvious that the position of the mandible and the incisor inclination tend to change even after one year. Because the postoperative changes were small in quantity, we supposed they were mostly caused by occlusal changes. Clinically, occlusal relationship in the incisor area, i.e., overjet and overbite, was maintained to be normal. It was considered that the changes of incisal inclination after release of intermaxillary fixation were of a compensatory or adaptational response to a positional change of the mandible.

Three-dimensional analysis of facial morphology before and after orthognathic surgery.

A method for three-dimensional analysis of the facial hard- and soft-tissue morphologies is described. The soft-tissue analysis consisted of calculating three-dimensional values of reference points on the face by perspective transformation of their values in two pairs of photographs, taken simultaneously, from the right and left sides of the face. The shape of the mandible was analyzed three-dimensionally by the simultaneously taken frontal and lateral cephalograms. The hard- and soft-tissue changes were analyzed with the method in 28 patients in whom mandibular prognathism had been corrected by orthognathic surgery. The magnitude of the surgically-produced soft tissue volumetric changes in the anterior mandibular region was proportional to the posterior movement of the mandible. Asymmetry of the face also improved in response to correction of lateral deviation of the mandible and a close correlation between the directional indices of asymmetry of the hard and soft tissues was observed. Thus, the method was found to be quite useful for the analysis of facial morphology in jaw deformity.

Impairment of the inferior alveolar nerve after sagittal split osteotomy.

The incidence and degree of neurosensory disturbance of the inferior alveolar nerve, as well as its recovery course, were studied on 46 sides in 23 patients who had undergone bilateral sagittal split osteotomies, by means of subjective symptoms, light touch, anaesthesiometer and two-point discrimination. The degree of disturbance was classified into mild, moderate and severe grades by the threshold pressure shown in tests with the anaesthesiometer. The disturbance, which was almost exclusively limited to mild (37%) and severe (28%) grades, was observed in 67% of the sample at one week. The disturbance disappeared completely within one to three months postoperatively in most sites with mild disturbance, and within three months to one year in half of the severely affected sites. Although the recovery was delayed in the other half of the severely disturbed sites, the disturbance was of mild grade at one and a half years. The overall incidence of disturbance at one year was 15%. Computed tomographic examination of the ascending ramus showed that the narrowest width between the mandibular canal and the buccal cortical plate ranged from 0 mm to 3.2 mm with a mean of 1.6 +/- 0.9 mm (SD) and it was less than 1.2 mm in 91% of sites with a severe grade disturbance, whereas it was distributed in a range of 0.9 mm to 3.2 mm in sites with no disturbance or with mild or moderate disturbance. The importance of preoperative computed tomography to indicate the location of the mandibular canal and the use of a thin cement spatula for the osteotomy was stressed, to avoid or reduce postoperative development of neurosensory impairment.

Xerox copy of the dental cast for analysis of the stability of mandibular osteotomy.

Stability of the mandible was analysed with a Xerox copy of the dental cast in 35 cases of mandibular prognathism corrected by ramus osteotomies. The occlusal relationship in the Xerox copy was illustrated by superimposing two contact points on the upper and lower dental arches and the change in the position of the lower dental arch in relation to the upper dental arch was obtained by superimposing the latter on preoperative, predicted postoperative, and six months postoperative occlusions. The stability of the mandible was analysed by measuring the movement of five landmarks (two posterior, two molar and one incisor points) set around the lower dental arch to represent the movement of the mandible. The relapse was estimated by the movements of the landmarks from the predicted postoperative occlusion to the six months postoperative occlusion. The mean estimated anterior relapses at the posterior and molar points with the larger predicted movement and the incisor point were between 0.9 mm. and 2.0 mm. at six months postoperatively, whereas on the side with the smaller predicted movement, the points moved posteriorly by 0.6 mm. and 0.5 mm. Despite the fact that the amount of the predicted lateral movement was much smaller than that of the predicted posterior movement at operation, the posterior points were estimated to relapse laterally by 2.0 mm. and 1.7 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Three-dimensional prediction of mandibular movement in the treatment of prognathism.

The three-dimensional movements of the mandible that might occur during surgical correction of mandibular prognathism were analyzed preoperatively in 40 patients. Direct measurements were made on the dental models used to predict postoperative occlusion, and the results were transferred to the cephalometric tracings using three-dimensional coordinate transformation. Menton, gonion, and two bony points on the posterior borders of the ascending rami were chosen on the frontal and lateral cephalograms for prediction of the antero-posterior, vertical, and lateral movements. In most cases a reasonable amount of movement without much lateral shift at the posterior border of the mandible was predicted to occur when the postoperative position of the mandible was established to provide a stable occlusion. However, there were five cases in which predicted lateral movement at one of the posterior borders exceeded 5 mm, and, in four of them, protrusion of the mandible was not accompanied by lateral deviation. It was concluded that careful preoperative planning and postoperative treatment are necessary in these cases because a large amount of lateral movement at the site of operation might lead to postoperative relapse following ramus osteotomy.

Root resorption of upper permanent incisor caused by impacted canine. An analysis of 23 cases.

Unusual root resorption of 12 central and 11 lateral upper permanent incisors in 11 patients is described. The degree of resorption ranged from loss of the apical 1/4 to almost complete loss of root structure. Excepting 1 case, permanent canines were partially or completely impacted and their crowns were in close apposition to the resorbed surfaces of the incisors. The roots of the canines were either in the process of formation or completely formed. The findings suggest that the pressure from the canine which persists in moving downward despite the lack of space to permit normal eruption could cause root resorption of adjacent incisors even in the absence of systemic factors. Of 14 extracted incisors, 10 were replaced orthodontically by the impacted canines, whereas the spaces of the extracted incisors were restored by prosthetic means in the 4 other cases. 6 incisors were preserved without any treatment and 2 with the aid of a sapphire dento-osseous anchor pin. Since the resorbed incisors were mostly free of pain, early detection by radiographic examination is essential to establish a proper diagnosis.