A compact low-temperature hydrogen ion beam apparatus for in situ physical property measurements.

A new compact low-temperature hydrogen ion beam apparatus has been developed for in situ physical property measurements. Introduction of hydrogen can significantly alter the physical properties of materials. Conventional methods such as exposure to H2 gas are limited to materials having hydrogen sorption. The present method is, in principle, applicable to any material of interest. Our setup provides a facile way to conduct both low-temperature hydrogen ion beam irradiation and in situ electrical resistivity measurements, which enables observation of novel physical properties induced by the low-temperature irradiation. The lowest temperature of 3.8 K was achieved by utilizing a newly designed rotatable radiation shield and a closed-cycle cryostat, which is advantageous for long-time low-temperature experiments for heavy hydrogen doping and in situ analysis. It was found that the resistivity of ZnO largely decreased by hydrogen ion beam irradiation at 50 K. Furthermore, the in situ measurements revealed an unforeseen irreversible thermal hysteresis for resistivity.

Modification of a melanoma discrimination index derived from hyperspectral data: a clinical trial conducted in 2 centers between March 2011 and December 2013.

BACKGROUND: The morphology of pigmented skin lesions (PSLs) is predominantly a result of varying concentrations and distributions of pigmented molecules such as melanin and hemoglobin. Based on these differences and the fact that their information is contained in cutaneous spectra, a hyperspectral imager (HSI) for pigmented melanoma and a single discrimination index derived from the resultant hyperspectral data are proposed. OBJECTIVE: To develop and evaluate a new discrimination index for melanomas, compared to the previous index. METHODS: A HSI, which is convenient for both patients and clinicians, was newly developed and used in a clinical trial conducted in 2 centers with 80 patients with primary lesions and 17 volunteers between March 2011 and December 2013. There were 24 melanomas and 110 other PSLs. A previously proposed discrimination index was used without modifications. A new index, which emphasized the essential features of melanoma, was proposed, and its performance was examined. For each index, a threshold value was set to minimize the average value of the false positive and false negative fractions. The performances of both indices were compared. RESULTS: The sensitivity and specificity of the old index were 75% and 97%, respectively, while those of the new index were 96% and 87%. CONCLUSION: The new index had a higher sensitivity and adequate specificity, indicating that it is more useful than the old index.

Size and shape variability in human molars during odontogenesis.

Under the patterning cascade model (PCM) of cusp development inspired by developmental genetic studies, it is predicted that the location and the size of later-forming cusps are more variable than those of earlier-forming ones. Here we assessed whether differences in the variability among cusps in total and each particular crown component (enamel-dentin junction [EDJ], outer enamel surface [OES], and cement-enamel junction [CEJ]) could be explained by the PCM, using human maxillary permanent first molars (UM1) and second deciduous molars (um2). Specimens were µCT-scanned, and 3D models of EDJ and OES were reconstructed. Based on these models, landmark-based 3D geometric morphometric analyses were conducted. Size variability in both tooth types was generally consistent with the above prediction, and the differences in size variation among cusps were smaller for the crown components completed in later stages of odontogenesis. With a few exceptions, however, the prediction was unsupported regarding shape variability, and UM1 and um2 showed different patterns. Our findings suggested that the pattern of size variability would be caused by temporal factors such as the order of cusp initiation and the duration from the beginning of mineralization to the completion of crown formation, whereas shape variability may be affected by both topographic and temporal factors.

Hyperspectroscopic imager for baby fibers.

Hyperspectral imaging system for diagnosing digestive diseases was newly developed in order to obtain information on pathology beyond morphology of lesions. In order to guide light reflected from a lesion, a baby fiber, which can be inserted in a forceps channel of the electronic endoscope, was also developed. The performance of the system was evaluated by animal experiment. Obtained hyperspectral data were found to have sufficient quality endurable to practical use. Harmful phenomena to a living body were not observed within the experiment. It was considered from the animal experiment that the present system could be practically used for humans.

Development of a new measurement system to detect selectively volatile organic compounds derived from the human body.

A new concept expired gas measurement system used double cold-trap method was developed. The system could detect selectively volatile organic compound (VOC) derived from the human body. The gas chromatography (GC) profiles of healthy volunteer's expired gas collected by our system were analyzed. As a result, 60 VOCs were detected from the healthy volunteer's expired gas. We examined 14 VOCs among them further, which could be converted to the concentration from the GC profiles. The concentration of almost VOCs decreased when the subjects inspired purified air compared with the atmosphere. On the other hand, isoprene was almost the same. It was strongly suggested that these VOCs were derived from the human body because the concentration of these VOCs in the atmosphere were nearly zero. Expired gas of two sleep apnea syndrome (SAS) patients were analyzed as preliminary study. As a result of the study, the concentration of some VOCs contained in the expired gas of the SAS patients showed higher value than a healthy controls.

Melanoma screening system using hyperspectral imager attached to imaging fiberscope.

Early detection and proper excision of the primary lesions of melanoma are crucial for reducing melanoma-related deaths. In order to support the early detection of melanoma, melanoma screening systems have been extensively studied and developed. Recently we have proposed a melanoma discrimination index derived from hyperspectral data (HSD) in the visible-near infrared wavelength region. The index represents variegation in spectra over a lesion and works well in discriminating melanoma from other pigmented lesions. However the previous hyperspectral imager did not have an enough allowance for measurement of lesions. To overcome the problem with it, we have developed a hyperspectral imager attached to imaging fiberscope. This equipment has been able to accumulate HSD in a view field of φ40 mm within about 10 seconds, from which the above-mentioned melanoma discrimination index has been calculated. Performance of the system has been studied in nine cases of melanoma and 18 cases of non-melanoma, obtained from patients and volunteers, all of whom were Japanese. The index has achieved a sensitivity of 100 % and a specificity of 94.4 %.

Identification of QTLs that control clubroot resistance in Brassica oleracea and comparative analysis of clubroot resistance genes between B. rapa and B. oleracea.

To perform comparative studies of CR (clubroot resistance) loci in Brassica oleracea and Brassica rapa and to develop marker-assisted selection in B. oleracea, we constructed a B. oleracea map, including specific markers linked to CR genes of B. rapa. We also analyzed CR-QTLs using the mean phenotypes of F(3) progenies from the cross of a resistant double-haploid line (Anju) with a susceptible double-haploid line (GC). In the nine linkage groups obtained (O1-O9), the major QTL, pb-Bo(Anju)1, was derived from Anju with a maximum LOD score (13.7) in O2. The QTL (LOD 5.1) located in O5, pb-Bo(GC)1, was derived from the susceptible GC. Other QTLs with smaller effects were found in O2, O3, and O7. Based on common markers, it was possible to compare our finding CR-QTLs with the B. oleracea CR loci reported by previous authors; pb-Bo(GC)1 may be identical to the CR-QTL reported previously or a different member contained in the same CR gene cluster. In total, the markers linked to seven B. rapa CR genes were mapped on the B. oleracea map. Based on the mapping position and markers of the CR genes, informative comparative studies of CR loci between B. oleracea and B. rapa were performed. Our map discloses specific primer sequences linked to CR genes and includes public SSR markers that will promote pyramiding CR genes in intra- and inter-specific crosses in Brassica crops. Five genes involved in glucosinolates biosynthesis were also mapped, and GSL-BoELONG and GSL-BoPro were found to be linked to the pb-Bo(Anju)1 and Bo(GC)1 loci, respectively. The linkage drag associated with the CR-QTLs is briefly discussed.

Involvement of Rho kinase in the pathogenesis of acute pulmonary embolism-induced polystyrene microspheres in rats.

Acute pulmonary embolism (PE) is a life-threatening disease, and several vasoconstrictors, including endothelin-1 (ET-1), play a key role in vasoconstriction and hypoxemia during the development of PE. Rho kinase is activated by various vasoconstrictors resulting in vascular contraction and remodeling. Recent evidence has revealed an important role of Rho kinase in the pathogenesis of systemic and pulmonary vascular diseases. However, contribution of Rho kinase in PE remains unclear. We thus investigated the role of Rho kinase in the PE rat model induced by intrajugular administration of polystyrene microspheres (mean diameter, 26 microm). At 6 h following the administration of microspheres (1.5 ml/kg), right ventricular systolic pressure (RVSP) was higher in the PE than in the control rats (15.8 +/- 1.6 vs. 32.9 +/- 7.5 mmHg). Arterial oxygen tension was lower (92.3 +/- 12.5 vs. 66.0 +/- 17.7 Torr), and alveolar-arterial difference in oxygen partial pressure was higher (3.9 +/- 3.8 vs. 36.5 +/- 26.9 Torr) in the PE rats. Western blotting analysis revealed upregulation and downregulation in expression of vascular cell adhesion molecule-1 and endothelial nitric oxide synthase in lungs from the PE rats, respectively, and radioimmunoassay demonstrated an increase in plasma ET-1 levels. Lung Rho kinase alpha expression was greater in the PE rats. At 5 h following administration of microspheres (0.75 ml/kg), intravenous Rho kinase inhibitors HA1077 and Y27632 (3 mg/kg each) attenuated elevation of RVSP (22.0 +/- 3.7, 17.1 +/- 3.2, 14.3 +/- 2.6 mmHg, PE, PE+HA1077, PE+Y27632) and the severity of hypoxemia (66.3 +/- 16.2, 94.9 +/- 23.0, 89.1 +/- 8.5 Torr, PE, PE+HA1077, PE+Y27632) in the PE rats. These results suggest that pulmonary endothelial dysfunction and activation of Rho kinase may contribute to the potentiation of vasoconstriction and hypoxemia in the PE rats.

Estimation of variability of specific absorption rate with physical description of children exposed to electromagnetic field in the VHF band.

Recently, there has been an increasing concern regarding the effects of electromagnetic waves on the health of humans. The safety of radio frequency electromagnetic fields (RF-EMFs) is evaluated by the specific absorption rate (SAR). In recent years, SAR has been estimated by numerical simulation using fine-resolution and anatomically realistic reference whole-body voxel models of people of various ages. The variation in SAR with a change in the physical features of a real person is hardly studied, although every person has different physical features. In this study, in order to estimate the individual variability in SAR of persons, we obtained considerable 3D body shape data from actual three-year-old children and developed several homogeneous models of these children. The variability in SAR of the homogeneous models of three-year-old children for whole-body exposure to RF electromagnetic fields in the very high frequency (VHF) band calculated using the finite-difference time-domain method has been described.

Macular microcirculation and macular oedema in branch retinal vein occlusion.

BACKGROUND/AIMS: The relationship between the blood-flow velocity in the perifoveal capillaries and macular oedema was investigated in patients with branch retinal vein occlusion (BRVO). METHODS: This study compared 18 patients with BRVO and 16 healthy volunteers. Perifoveal capillary blood-flow velocity was measured on fluorescein angiograms with a scanning laser ophthalmoscope by the tracing method. Retinal thickness at the central fovea was measured by optical coherence tomography. Then, the relation between perifoveal capillary blood-flow velocity and retinal thickness at the central fovea was investigated. RESULTS: Perifoveal capillary blood-flow velocity was significantly lower in the patients with BRVO (1.08 (SD 0.28) mm/s) than in the healthy volunteers (1.49 (0.11) mm/s) (p<0.0001). Capillary blood-flow velocity showed a negative correlation with the retinal thickness at the central fovea in the two groups (r = -0.8426, p<0.0001). Multivariate linear regression analysis with stepwise variable selection confirmed that capillary blood-flow velocity was an independent determinant of the retinal thickness at the central fovea (p<0.001). CONCLUSION: A reduction in perifoveal capillary blood-flow velocity may be involved in the development of macular oedema in patients with BRVO.

Gadolinium-enhanced three-dimensional magnetization-prepared rapid gradient-echo (3D MP-RAGE) imaging is superior to spin-echo imaging in delineating brain metastases.

BACKGROUND: Precisely defining the number and location of brain metastases is very important for establishing a treatment strategy for malignancies. Although magnetic resonance imaging (MRI) is now considered the best modality, various improvements in sequences are still being made. PURPOSE: To prospectively compare the diagnostic ability of three-dimensional, magnetization-prepared rapid gradient-echo (3D MP-RAGE) imaging in detecting metastatic brain tumors, with that of two-dimensional spin-echo (2D SE) T1-weighted imaging. MATERIAL AND METHODS: A total of 123 examinations were included in this study, and 119 examinations from 88 patients with known malignancies were analyzed. All patients underwent T1- and T2-weighted 2D SE transverse imaging, followed by gadolinium-enhanced T1-weighted transverse and coronal 2D SE imaging and 3D MP-RAGE transverse imaging. Four radiologists interpreted the images to compare the accuracy and the time required for interpretation for each imaging. RESULTS: 3D MP-RAGE imaging was significantly better than 2D SE imaging for detecting metastatic brain lesions, regardless of the readers' experience. The sensitivities of the 3D MP-RAGE and 2D SE imaging for all observers were 0.81 vs. 0.80 (P>0.05), specificities were 0.93 vs. 0.87 (P<0.05), positive predictive values were 0.92 vs. 0.86 (P<0.05), negative predictive values were 0.78 vs. 0.75 (P>0.05), and accuracies were 0.84 vs. 0.78 (P<0.05), respectively. There was no significant difference in the time required for image interpretation between the two modalities (15.6+/-4.0 vs. 15.4+/-4.1 min). CONCLUSION: 3D MP-RAGE imaging proved superior to 2D SE imaging in the detection of brain metastases.

Dienogest, a selective progestin, reduces plasma estradiol level through induction of apoptosis of granulosa cells in the ovarian dominant follicle without follicle-stimulating hormone suppression in monkeys.

Dienogest is a selective progestin that has been shown to arrest ovarian follicular development in women, without affecting gonadotropin secretion. As luteal progesterone or exogeneous progestins are known to suppress ovarian folliculogenesis via the inhibition of gonadotropin secretion, this action of dienogest on ovaries seems to be unique. To examine the underlying mechanism of the antifolliculogenic effect of dienogest, female cynomolgus monkeys were treated with a single oral dose of 0.1 mg/kg dienogest on day 7 of the menstrual cycle. Plasma FSH, estradiol (E2), and progesterone levels were measured up to 15 days after dosing. In an additional experiment, ovaries were excised 24 h after dosing for histological examinations. As a result, plasma E2 level declined within 24 h after dosing, while dienogest did not decreased FSH level prior to E2 decline. After decline of E2 level, the low level of E2 was sustained for more than 11 days. It is considered that a single oral dose of dienogest induced atresia of the dominant follicle. In the histological examination, two out of three animals showed decline in E2 level. The ovarian dominant follicles from these animals showed apoptotic changes in granulosa cells with scattered aromatase expression within 24 h after dosing. These results indicate that the induction of atresia of the ovarian dominant follicle by direct action would be a possible mechanism of dienogest to inhibit plasma E2 level.

Effect of panretinal photocoagulation on choroidal circulation in the foveal region in patients with severe diabetic retinopathy.

AIM: To study alterations in choroidal blood flow (CBF) in the foveal region after panretinal photocoagulation (PRP) in patients with severe proliferative diabetic retinopathy. METHODS: Seventeen eyes of 17 patients with severe non-proliferative diabetic retinopathy (PDR) or with non-high-risk PDR and no macular oedema before PRP were included. All patients underwent four sessions of scatter PRP. We measured the choroidal blood velocity (CBVel), choroidal blood volume (CBVol) and CBF in the foveal region before and 1 month after PRP using a laser Doppler flowmetry. RESULTS: Macular oedema did not develop after PRP in any treated eyes. One month after PRP, there was no significant change in the mean CBVel (311.2 (SD 61.2) Hz) compared with baseline (327.1 (74.1) Hz) (p = 0.17). In contrast, the mean CBVol and CBF values increased significantly by 51% (from 0.37 (0.12) arbitrary units (au) at baseline to 0.52 (0.16) au, p = 0.0025) and 46% (from 7.3 (2.4) au at baseline to 10.4 (4.4) au, p = 0.0014), respectively, 1 month after PRP. CONCLUSION: These results indicate that PRP may increase the CBF in the foveal region in eyes with severe diabetic retinopathy. The current results may be caused by vasodilation of the choriocapillaries in the foveal region.

Anatomically realistic reference models of pregnant women for gestation ages of 13, 18, and 26 weeks.

The safety of a human body exposed to radio-frequency (RF) electromagnetic fields (EMFs) has become important today. In recent times, conducting numerical dosimetry on the mother and the fetus during pregnancy has become a particularly important issue. This paper outlines the development of pregnant woman models that were adjusted to the reference values of physiological characteristics of maternal tissues in pregnant women for gestation ages of 13, 18, and 26 weeks The models are composed of voxels of 2 x 2 x 2 mm(3), and there are 56 tissue types. The basic specific absorption rate (SAR) characteristics in the pregnant woman models for whole-body exposure to RF electromagnetic fields that were calculated using the finite-difference time-domain (FDTD) method are described here.

Ca channel currents inhibited by serum from select patients with Guillain-Barré syndrome.

We performed an electrophysiological study demonstrating inhibition of spontaneous muscle action potentials within a coculture of rat muscle and spinal cord by exposure to serum, as well as purified IgG, from patients with the acute motor axonal neuropathy (AMAN) variant of Guillain-Barré syndrome (GBS). However, exposure to serum from two patients with the acute inflammatory demyelinating polyneuropathy (AIDP) form of GBS had no effect. Using a whole-cell recording technique, we then investigated the effects of serum and purified IgG from patients with GBS on voltage-dependent calcium channel (VDCC) currents in nerve growth factor-differentiated PC12 cells. Serum from patients with GBS (AMAN) inhibited VDCC currents in PC12 cells, which was fully reversible by washing with the bath solution. Similarly, purified IgG from the serum of two patients with GBS (AMAN) also inhibited VDCC currents in PC12 cells. In contrast, sera from patients with AIDP and healthy volunteers did not affect VDCC currents in PC12 cells. These results suggest that muscle weakness in some patients with GBS might be induced by inhibition of Ca2+ channel currents within motor nerve terminals.

Effect of pH and hydration on the normal and lateral interaction forces between alumina surfaces.

Interaction forces between alumina surfaces were measured using an AFM-colloid probe method at different pHs. For an alpha-alumina-sapphire system at acidic pH, the force curve exhibited a well-defined repulsive barrier and an attractive minimum. At basic pH, the interactive force was repulsive at all separations with no primary minimum. Lateral force measurements under the same conditions showed that frictional forces were nearly an order of magnitude smaller at basic pH than those observed at acidic pH. This behavior was attributed to the hydration of the alumina surface. Normal and lateral force measurements with the strongly hydrated rho-alumina surfaces supported these findings.

Choroidal blood flow in the foveal region in eyes with rhegmatogenous retinal detachment and scleral buckling procedures.

AIMS: To investigate changes in choroidal blood flow (ChBF) in the foveal region of the human eye with rhegmatogenous retinal detachment induced by scleral buckling. METHODS: ChBF was measured in the foveal region using laser Doppler flowmetry in patients with a rhegmatogenous retinal detachment and no macular involvement before and after scleral buckling. The ChBF ratio was evaluated (ChBF of the affected eye to ChBF of the fellow control eye) to minimise individual variations. RESULTS: Retinal reattachment was confirmed by 2 weeks after scleral buckling in all patients. The ChBF in the foveal region of the affected eyes did not differ from the fellow eyes before scleral buckling. The ChBF ratio significantly (p<0.05) decreased 2 and 4 weeks after scleral buckling compared with that before scleral buckling and returned to baseline 12 weeks after scleral buckling. CONCLUSIONS: The results suggest that ChBF in the foveal region transiently decreases after scleral buckling and recovers to the baseline level within 12 weeks in patients with a retinal detachment and no macular involvement.

Diffusion tensor feature in vasogenic brain edema in cats.

We investigated the correlation between the changes in diffusion tensor magnetic resonance imaging, regional water content, and tissue ultrastructure after vasogenic brain edema induced by cortical cold lesioning. In this cat model, E3 in the white matter was dominantly increased while fractional anisotropy (FA) was significantly decreased 8 hours after cortical cold lesioning. This finding indicates that water diffusion in the cortical white matter mainly increased perpendicularly rather than parallel to the direction of the nerve fibers. Additionally, in the area where edema is mild or moderate (tissues with water content of 65% to 75%), FA in the chronic phase was significantly lower than that in the acute phase. Histological examination demonstrated disordered arrangement of nerve fibers, highly dissociated neuronal fibers due to extracellular accumulation of protein rich-fluid, and enlarged interfiber spaces in the acute phase.