Measurement method of Stokes parameters using a quarter-wave plate with phase difference errors

The Stokes parameters (S0, S1, S2, and S3) of monochromatic light can be measured using the adjustable azimuth settings of a quarter-wave plate and a polarizer. When measuring the Stokes parameters of light of an arbitrary wavelength, the measurement of S3 is affected by the phase difference error Δq(λi), due to the mismatch with respect to wavelength with the quarter-wave plate. In this method, Δq(λi), due to such a mismatch of incident light of arbitrary wavelength, can be overcome by a judicious choice of azimuth settings of the quarter-wave plate and the use of a polarizer; however, the use of a precision quarter-wave plate is necessary. The present paper proposes a measurement method of Stokes parameters of incident light of arbitrary wavelength using a quarter-wave plate with phase difference errors.     

Nonmechanical transverse scanning laser Doppler velocimeter using wavelength change

A transverse scanning laser Doppler velocimeter (LDV) that does not require any moving mechanism in its sensor probe is proposed, and the scanning function is demonstrated theoretically and experimentally. In the proposed scanning LDV, the measurement position is transversely scanned on the basis of a wavelength change induced by a tunable laser and a combination of a grating and a Dove prism. To demonstrate the scanning function in the transverse direction, an experiment was carried out using a setup of the sensor probe consisting of bulk optical components. The experimental results indicate that a transverse scanning function was successfully obtained. The scanning range in the vertical direction is estimated to be 11.3 mm over wavelengths of 1520 to 1570 nm.     

Low-loss dispersion-shifted polarisation-maintaining fibres

Low-loss polarisation-maintaining fibres, with the zero dispersion wavelength shifted to 1.56 ?m, have been fabricated. A minimum transmission loss of 0.27 dB/km and crosstalk of ?22dB over a length of 4.1km, corresponding to h = 1.53 × 10-6m-1, are achieved at the same wavelength.     

Reconstruction of a congenital hypoplastic thumb with use of a free vascularized metatarsophalangeal joint

Reconstruction of a Blauth type-IIIB hypoplastic thumb with use of a free vascularized metatarsophalangeal joint was performed in four patients (four hands). Several tendon transfers also were performed, either primarily or secondarily, to mobilize the reconstructed thumb. Three patients (three hands) were followed for at least two years after the reconstruction; the results for these three patients were compared with those for four patients (six hands) who had been managed with pollicization of the index finger because of a similar deformity of the thumb. The patients were evaluated with regard to grip strength, key-pinch strength, and the range of motion of the joints of the thumb in the operatively treated and contralateral hands as well as with regard to skill in performing activities of daily living as assessed with use of the Kobe hand-function test. Although the appearance of the thumb was closer to normal in the group that had had the pollicization procedure, total function of the hand and grip strength were greater in the group that had had the transfer procedure. We believe that reconstruction of an unstable hypoplastic (Blauth type-IIIB) thumb with use of a vascularized metatarsophalangeal joint is an acceptable alternative to pollicization of the index finger.     

Serial MRI, SPECT and 1H-MRS findings in a case of herpes simplex encephalitis

Thyroid-associated ophthalmopathy (TAO) is a progressive eye disorder associated with Graves' hyperthyroidism, which is generally considered to have an autoimmune etiology. Eye muscle membrane proteins of 64 kd are good markers of ophthalmopathy in patients with thyroid autoimmunity. The 64-kd protein is now shown from a partial sequence to be the flavoprotein subunit (Fp) of mitochondrial succinate dehydrogenase. Hyperthyroidism due to Graves' disease is increasing in incidence among urban black female Africans, possibly because of exposure to environmental risk factors such as increased dietary iodine ingestion and stress. Ophthalmopathy is frequently observed in this clinical context, but its association with serum autoantibodies reactive with Fp has not been examined. We studied 19 black South African patients with Graves' disease during the course of prolonged antithyroid drug administration, of whom 10 had congestive ophthalmopathy, but no clinical evidence for eye muscle damage at the onset. Anti-Fp antibodies were detected in 2 of these patients, as well as in 2 of the 9 patients who did not have overt eye disease. Additionally, the antibodies became positive in 3 patients with ophthalmopathy in whom tests were negative initially, remained positive in 1 patient throughout the study period and became negative in 1 patient with positive tests initially. Ophthalmopathy did not develop in any of the 9 patients who lacked this complication on presentation. The reasons why we failed to demonstrate a close relationship between anti-Fp antibodies and the eye muscle component of ophthalmopathy are unclear although one possibility is that ocular myopathy is an uncommon manifestation in African thyrotoxic patients compared with those of Caucasian origin. The relationship between anti-Fp antibodies and eye muscle inflammation in patients with thyroid autoimmunity of different ethnic origins and environmental settings, needs to be addressed in a large prospective study.     

MRI of groove pancreatitis

PURPOSE: The purpose of this work is to describe the findings on MRI in patients with groove pancreatitis, a specific form of chronic pancreatitis affecting the groove between the pancreatic head, the duodenum, and the common bile duct. METHOD: MR images, including MR cholangiopancreatography, of five patients with groove pancreatitis were reviewed. Three patients underwent pancreatoduodenectomy due to serve duodenal stenosis, and the MR findings were compared to the histologic findings. RESULTS: A sheet-like mass was demonstrated between the pancreatic head and the duodenum in all patients. The masses were hypointense relative to pancreatic parenchyma on T1-weighted images and iso- to slightly hyperintense on T2-weighted images. After administration of Gd-DTPA, the masses showed delayed enhancement. Histologically, fibrous scar tissue was detected in the groove. CONCLUSION: MR images can clearly demonstrate the fibrous tissue in the groove in groove pancreatitis, and MR cholangiopancreatography can also provide useful information.     

Pseudoxanthoma elasticum-like papillary dermal elastolysis: report of four Japanese cases and an immunohistochemical study of elastin and fibrillin-1

Fourier transform infrared and Raman (FT-IR and FT-Raman) microspectroscopy were used to study materials found in human tissue. Individual cases involving cholesterol, calcium stearate, and a polystyrenesulfonate ion exchange resin demonstrate the utility of the spectroscopic data. Characteristic spectral bands for these materials were compared with those of authentic chemical species to confirm their identities. The role of vibrational spectroscopy in pathologic diagnoses is discussed.     

Phonon Dispersion Measurements of YBa2Cu3O6.15 and YBa2Cu3O6.95 by Time-of-Flight Neutron Spectroscopy

We measured the phonon dispersions of YBa₂Cu₃O_6.15 and YBa₂Cu₃O_6.95 by time-of-flight inelastic neutron scattering. The in-plane bond-stretching modes in the metallic phase showed a distinct a-b plane anisotropy beyond what is expected for structural origin. Such anisotropy in the longitudinal optical modes, which is absent in the TO, suggests strong in-plane anisotropy in the underlying electronic structure. Apical oxygen bond-stretching modes showed a large frequency change between the insulating and the metallic phases. This large softening also is beyond structural origin, and suggests the effect of local electronic environment.