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2.
Rev Sci Instrum ; 94(8)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-38065179

RESUMEN

Understanding the behaviors of materials in their operating and manufacturing environments is essential not only in the scientific field, but also in the context of designing industrial materials for target applications. In this study, we developed a high-temperature x-ray diffraction (XRD) system, using a small microscope heating stage at the BL02B2 beamline in SPring-8. Newly designed sample cells composed of sapphire single crystals were employed to perform XRD experiments using powdered samples at high temperatures and under oxidization/reduction gas atmospheres, with a short sample exchange time. More specifically, XRD experiments were conducted under vacuum, air, inert gas (maximum temperature: ∼1400 °C), and reduction gas flow conditions (maximum temperature: ∼900 °C). In addition, to monitor the changes in the exhausted gas composition during the chemical reactions, the developed heating system was combined with in situ gas-analysis tools (a remote gas-pressure control system, gas chromatograph, and mass spectrometer), which allowed analysis of the gas-adsorption/desorption and solid-gas reaction processes. Several heating experiments, such as the observation of the reduction of Fe oxides, phase transitions of ZrO2 and BaCO3, and synthesis of BaZrO3, demonstrated the validity and usefulness of this system.

3.
J Neonatal Perinatal Med ; 16(3): 569-571, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37718855

RESUMEN

The most common cause of acquired hydrocephalus in infants is hemorrhage, most often as a consequence of prematurity. Other important causes include neoplasm and infection, usually bacterial meningitis. Hypoxic ischemic encephalopathy (HIE) in term infants usually results in secondary microcephaly. We report an infant with severe HIE at birth treated by therapeutic hypothermia who developed progressive acquired hydrocephalus over 2 months, although no cause of the hydrocephalus was identified. Although hydrocephalus, even intraventricular hemorrhage, is uncommon in term infants with HIE, careful follow-up of the head circumference is important, even if no findings indicating possible causes of hydrocephalus, such as hemorrhage, are detected on ultrasound or magnetic resonance imaging.

4.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37671952

RESUMEN

A retroreflector array, composed of a cluster of small retroreflectors, is experimentally studied for application to a Michelson-type interferometer system in the fusion plasma experiment. Such a new-type reflector has the potential to be a vital and effective tool at a spatially limited location, such as on the vacuum chamber wall of plasma experimental devices. To investigate the effect of retroreflector array on the reflected beam properties, a tabletop experiment is performed with the retroreflector array composed of 4 mm corner-cube retroreflectors and with a 320-GHz (λ ∼ 0.937 mm) submillimeter wave source. An imaging camera is utilized to measure the submillimeter wave beam profile and is scanned perpendicularly to the beam propagation direction if necessary. The experimental result exhibits a diffraction effect on the reflected beam, resulting in the emergence of discrete peaks on the reflected beam profile, as predicted in the past numerical study; however, the most reflected beam power converges on the one reflected into the incident direction, resulting from a property as a retroreflector. Furthermore, the dependence of the reflected beam on the incident beam angle is characterized while fixing the detector position, and the retroreflection beam intensity is found to vary due to the diffraction effect. Such an undesired variation of beam intensity induced by the diffraction can be suppressed with a focusing lens placed in front of the detector in the practical application to an interferometer.

5.
Plant Biol (Stuttg) ; 25(6): 833-841, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37408380

RESUMEN

Pollinator shifts are often related to speciation in angiosperms, and the relationship between them has been discussed in several plant taxa. Although limited information on plants pollinated by non-flying mammals in Central and South America and Africa is available, related research has not been conducted in Asia. Herein, I summarize the available knowledge of pollination in Asian Mucuna (Fabaceae), a genus mainly distributed in the tropics, and discuss the evolution of plants pollinated by non-flying mammals in Asia. Nineteen pollinator species have been recorded and pollination systems have been categorized into four types. An examination of the relationship between Mucuna species and their pollinators from the lineage perspective revealed that all species in Mucuna, subgenus Macrocarpa, which are distributed in Asia, are pollinated exclusively by non-flying mammals. Additionally, plants pollinated by non-flying mammals were found to have diverged from bat-pollinated and non-flying mammal-pollinated plants, while plants pollinated by non-flying mammals have evolved multiple times. This is a unique example of evolutionary transition. I hypothesize that the diversification of squirrel species in tropical Asia may have led to the speciation and diversification of Mucuna in Asia. Furthermore, the behavioural and ecological characteristics of bats and birds in Asia differ from the characteristics of those in other regions, implying that Asian Mucuna species do not rely on bat or bird pollinators. The adaptation of floral characteristics to pollinators is not well understood in Asia. Mammal-pollinated plants in Asia may have evolved differently from those in other regions and have unique pollination systems.


Asunto(s)
Quirópteros , Fabaceae , Mucuna , Animales , Polinización , Flores , Mamíferos , Plantas
6.
Front Oncol ; 13: 1214977, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37483497

RESUMEN

Objectives: To evaluate whether tumor extracellular volume fraction (fECV) on contrast-enhanced computed tomography (CT) aids in the differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC). Methods: In this retrospective study, 113 patients with pathologically confirmed ICC (n = 39) or HCC (n = 74) who had undergone preoperative contrast-enhanced CT were enrolled. Enhancement values of the tumor (Etumor) and aorta (Eaorta) were obtained in the precontrast and equilibrium phase CT images. fECV was calculated using the following equation: fECV [%] = Etumor/Eaorta × (100 - hematocrit [%]). fECV values were compared between the ICC and HCC groups using Welch's t-test. The diagnostic performance of fECV for differentiating ICC and HCC was assessed using receiver-operating characteristic (ROC) analysis. fECV and the CT imaging features of tumors were evaluated by two radiologists. Multivariate logistic regression analysis was performed to identify factors predicting a diagnosis of ICC. Results: Mean fECV was significantly higher in ICCs (43.8% ± 13.2%) than that in HCCs (31.6% ± 9.0%, p < 0.001). The area under the curve for differentiating ICC from HCC was 0.763 when the cutoff value of fECV was 41.5%. The multivariate analysis identified fECV (unit OR: 1.10; 95% CI: 1.01-1.21; p < 0.05), peripheral rim enhancement during the arterial phase (OR: 17.0; 95% CI: 1.29-225; p < 0.05), and absence of washout pattern (OR: 235; 95% CI: 14.03-3933; p < 0.001) as independent CT features for differentiating between the two tumor types. Conclusions: A high value of fECV, peripheral rim enhancement during the arterial phase, and absence of washout pattern were independent factors in the differentiation of ICC from HCC.

7.
Rev Sci Instrum ; 93(11): 113519, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36461432

RESUMEN

A new 320 GHz solid-state source interferometer is installed in the Heliotron J helical device to explore the physics of high-density plasmas (ne > 2-3 × 1019 m-3, typically) realized with advanced fueling techniques. This interferometry system is of the Michelson type and is based on the heterodyne principle, with two independent solid-state sources that can deliver an output power of up to 50 mW. A high time resolution measurement of <1 µs can be derived by tuning the frequency of one source in the frequency range of 312-324 GHz on the new system, which can realize the fluctuation measurement. We successfully measured the line-averaged electron density in high-density plasma experiments. The measured density agreed well with a microwave interferometer measurement using a different viewing chord, demonstrating that the new system can be used for routine diagnostics of electron density in Heliotron J.

8.
Rev Sci Instrum ; 93(11): 113537, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36461543

RESUMEN

The Paα line (1875.13 nm) in the near-infrared (NIR) region was evaluated to apply Stark broadening of the line spectrum to the electron density measurement of the small-pellet ablation cloud in Heliotron J, a medium-sized helical-axis heliotron device. Paα is three-to-four times broader than the visible Hß line (486.13 nm) for the same electron density. Using a portable NIR spectrometer, preliminary proof-of-concept experiments determined the marginal density, below which the broadening was undetectable. The lower detection density limit can be decreased using a narrower entrance slit or a denser grating.

9.
Sci Rep ; 12(1): 21657, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36522382

RESUMEN

Two-dimensional (2D) triangular lattice antiferromagnets (2D-TLA) often manifest intriguing physical and technological properties, due to the strong interplay between lattice geometry and electronic properties. The recently synthesized 2-dimensional transition metal dichalcogenide LiCrTe[Formula: see text], being a 2D-TLA, enriched the range of materials which can present such properties. In this work, muon spin rotation ([Formula: see text]SR) and neutron powder diffraction (NPD) have been utilized to reveal the true magnetic nature and ground state of LiCrTe[Formula: see text]. From high-resolution NPD the magnetic spin order at base-temperature is not, as previously suggested, helical, but rather collinear antiferromagnetic (AFM) with ferromagnetic (FM) spin coupling within the ab-plane and AFM coupling along the c-axis. The value if the ordered magnetic Cr moment is established as [Formula: see text]. From detailed [Formula: see text]SR measurements we observe an AFM ordering temperature [Formula: see text] K. This value is remarkably higher than the one previously reported by magnetic bulk measurements. From [Formula: see text]SR we are able to extract the magnetic order parameter, whose critical exponent allows us to categorize LiCrTe[Formula: see text] in the 3D Heisenberg AFM universality class. Finally, by combining our magnetic studies with high-resolution synchrotron X-ray diffraction (XRD), we find a clear coupling between the nuclear and magnetic spin lattices. This suggests the possibility for a strong magnon-phonon coupling, similar to what has been previously observed in the closely related compound LiCrO[Formula: see text].

10.
Sci Rep ; 12(1): 14204, 2022 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-35987922

RESUMEN

Understanding pellet ablation physics is crucial to realizing efficient fueling into a high temperature plasma for the steady state operation of ITER and future fusion reactors. Here we report the first observation of the formation of fluctuation structures in the pellet plasmoid during the pellet ablation process by a fast camera in a medium-sized fusion device, Heliotron J. The fluctuation has a normalized fluctuation level of ~ 15% and propagates around the moving pellet across the magnetic field. By comparing the fluctuation structures with the shape of magnetic field lines calculated with the field line tracing code, we successfully reconstruct the spatio-temporal structure of the fluctuations during the pellet ablation process. The fluctuations are located at the locations displaced toroidally from the pellet and propagate in the cross-field direction around the pellet axis along the field line, indicating a three-dimensional behavior and structure of fluctuations. The fluctuation would be driven by a strong inhomogeneity formed around the pellet and invoke the relaxation of the gradient through a cross-field transport induced by the fluctuations, which could affect the pellet ablation and pellet fueling processes. Such fluctuations can be ubiquitously present at the inhomogeneity formed around a pellet in the pellet ablation process in fusion devices.

11.
Nat Commun ; 13(1): 1817, 2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35361763

RESUMEN

Magnetic refrigeration (MR) is a key technique for hydrogen liquefaction. Although the MR has ideally higher performance than the conventional gas compression technique around the hydrogen liquefaction temperature, the lack of MR materials with high magnetic entropy change in a wide temperature range required for the hydrogen liquefaction is a bottle-neck for practical applications of MR cooling systems. Here, we show a series of materials with a giant magnetocaloric effect (MCE) in magnetic entropy change (-∆Sm > 0.2 J cm-3K-1) in the Er(Ho)Co2-based compounds, suitable for operation in the full temperature range required for hydrogen liquefaction (20-77 K). We also demonstrate that the giant MCE becomes reversible, enabling sustainable use of the MR materials, by eliminating the magneto-structural phase transition that leads to deterioration of the MCE. This discovery can lead to the application of Er(Ho)Co2-based alloys for the hydrogen liquefaction using MR cooling technology for the future green fuel society.

13.
J Vet Cardiol ; 41: 220-226, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35477068

RESUMEN

A nine-month-old castrated male domestic shorthair presented for evaluation with a three-month history of hematuria. Portosystemic shunts and calculi within the bladder were suspected, and computed tomography angiography was performed. Computed tomography angiography identified an extrahepatic portosystemic shunt and a partial anomalous pulmonary venous connection, with the lobar vein of the right caudal lobe draining into the caudal vena cava. After anesthesia was administered to the cat, tachypnea and wheezing respiratory sounds were observed, and thoracic radiography revealed the right middle lung lobe atelectasis and an unstructured interstitial pattern in the left cranial lobe. Echocardiography showed left and right atrial enlargement and slight interventricular septal flattening in diastole. Based on these findings, cardiogenic pulmonary edema was suspected, and the cat was treated with furosemide. The clinical symptoms were resolved the next day. Closure of the extrahepatic portosystemic shunt was performed on days 47 and 157. Left atrial enlargement and interventricular septal flattening were attenuated after the procedure. At the time of writing this report (seventeen months after diagnosis), the cat exhibited no clinical signs, but subjective right atrial enlargement remained at approximately the same level. This report represents the first case of a partial anomalous pulmonary venous connection and a portosystemic shunt in a cat.


Asunto(s)
Derivación Portosistémica Intrahepática Transyugular , Venas Pulmonares , Animales , Gatos , Ecocardiografía/veterinaria , Pulmón/irrigación sanguínea , Masculino , Derivación Portosistémica Intrahepática Transyugular/veterinaria , Venas Pulmonares/anomalías , Radiografía Torácica
14.
Osteoarthritis Cartilage ; 30(3): 381-394, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34757028

RESUMEN

OBJECTIVE: To evaluate if gait biomechanics are associated with increased risk of structurally diagnosed disease onset or progression of lower limb osteoarthritis (OA). METHOD: A systematic review of Medline and Embase was conducted from inception to July 2021. Two reviewers independently screened records, extracted data and assessed risk of bias. Included studies reported gait biomechanics at baseline, and either structural imaging or joint replacement occurrence in the lower limb at follow-up. The primary outcome was the Odds Ratio (OR) (95% confidence interval (CI)) of the association between biomechanics and structural OA outcomes with data pooled for meta-analysis. RESULTS: Twenty-three studies reporting 25 different biomechanical metrics and 11 OA imaging outcomes were included (quality scores ranged 12-20/21). Twenty studies investigated knee OA progression; three studies investigated knee OA onset. Two studies investigated hip OA progression. 91% of studies reported a significant association between at least one biomechanical variable and OA onset or progression. There was an association between frontal plane biomechanics with medial tibiofemoral and hip OA progression and sagittal plane biomechanics with patellofemoral OA progression. Meta-analyses demonstrated increased odds of medial tibiofemoral OA progression with greater baseline peak knee adduction moment (KAM) (OR: 1.88 [95%CI: 1.08, 3.29]) and varus thrust presence (OR: 1.97 [95%CI: 1.32, 2.96]). CONCLUSION: Evidence suggests that certain gait biomechanics are associated with an increased odds of OA onset and progression in the knee, and progression in the hip. REGISTRATION NUMBER: PROSPERO CRD42019133920.


Asunto(s)
Marcha/fisiología , Osteoartritis de la Cadera/fisiopatología , Osteoartritis de la Rodilla/fisiopatología , Fenómenos Biomecánicos , Progresión de la Enfermedad , Humanos , Factores de Riesgo
15.
Rev Sci Instrum ; 92(6): 063503, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243580

RESUMEN

This study shows the feasibility of a beam emission spectroscopy (BES) diagnostic in the Helically Symmetric eXperiment (HSX) stellarator for obtaining the spatiotemporal structure of density fluctuation. A beam emission simulation was applied to HSX plasmas to design and optimize viewing chords and to estimate the beam emission spectrum. A Doppler-shifted beam emission spectrum was measured from a 30 kV, 4 A diagnostic neutral beam injected into HSX plasmas. The beam emission was measured with a high-time-resolution avalanche photodiode (APD) assembly to determine the feasibility of BES in HSX. For HSX plasmas heated by 28 GHz electron cyclotron heating, a mode around f = 15 kHz was observed in the BES signal. The coherence between the BES signal and the density fluctuation measured by an interferometer system was significant. A plan for improving the BES system to enable the measurement of higher frequency related to turbulent transport is presented. The array of sightlines proposed in this study can be used to measure beam emission with a Doppler shift larger than 3 nm (blue shift), which enables the use of a wide passband interference filter to obtain higher throughput. The adoption of a large objective optics and a chilled APD assembly will improve the signal-to-noise ratio.

16.
Rev Sci Instrum ; 92(5): 053519, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-34243360

RESUMEN

We report the development of a new interferometer with two stable, high-power, 320 GHz solid-state sources in Heliotron J. A heterodyne Michelson interferometer optical scheme is employed. Two solid-state oscillators are utilized as sources with a fixed frequency at 320 GHz and frequency tunable of 312-324 GHz. Quasi-optical techniques are used for beam transmission. The beam is elongated in the vertical direction with two off-axis parabolic mirrors and injected into the plasma as a sheet beam for the multi-channel measurement (>5 ch.). Passing through the plasma, the beam is reflected at a retroreflector-array installed at the vacuum chamber wall. The retroreflector-array is a bunch of retroreflector structures, which can suppress the beam refraction caused by plasma without much space inside a vacuum chamber unlike a single retroreflector and can facilitate the system design. The source, detectors, and the retroreflector-array are tested to evaluate their basic performance on a tabletop experiment.

17.
Clin Radiol ; 76(7): 551.e17-551.e24, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33902888

RESUMEN

AIM: To calculate the quantitative liver-portal vein contrast ratio (Q-LPC) cut-off value based on tumour detectability by using receiver operating characteristic (ROC) curves. MATERIALS AND METHODS: Seventy-four patients with tumours (46 men and 28 women; age, 71 ± 8.1 years), who underwent liver magnetic resonance imaging (MRI) using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) were enrolled. Some patients were found to have multiple tumours. In total, 102 tumour images were evaluated for quantitative liver-spleen contrast ratio (Q-LSC) and Q-LPC 10 minutes after the administration of Gd-EOB-DTPA. Q-LPC and Q-LSC were compared to assess the cut-off values and usefulness. The ROC curve was evaluated using the method for continuously distributed test results, with a free scale of 50 mm. A score of ≥30 out of 50 points was considered good. Cut-off values of Q-LPC and Q-LSC were then calculated. The areas under the ROC curve (AUCs) were also examined and compared. RESULTS: The AUC-ROC for Q-LPC was 0.858 (95% confidence interval [CI], 0.783-0.933). The cut-off value was determined to be at 1.462. Sensitivity was 0.747, and specificity was 0.852 at the cut-off value. The AUC-ROC for Q-LSC was 0.710 (95% CI, 0.597-0.822). The cut-off value was at 1.543, the sensitivity was 0.560, and the specificity was 0.778 at the cut-off value. A significant difference was noted between the AUCs (p=0.0016). CONCLUSION: Q-LPC can be used for hepatobiliary phase MRI evaluation.


Asunto(s)
Neoplasias Hepáticas/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Anciano , Medios de Contraste , Femenino , Gadolinio DTPA , Humanos , Masculino , Sensibilidad y Especificidad
19.
Rev Sci Instrum ; 92(3): 034711, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33820101

RESUMEN

A six-pole Q-band waveguide filter with a notch frequency above the Q-band has been developed for plasma diagnostics. The previous paper [Nishiura et al., J. Instrum. 10, C12014 (2015)] reported that the notch frequency exists within the standard band. In this study, the newly required notch filter extends the function, which prevents a thorny wave from being mixed into an instrument beyond the standard bandwidth of the waveguide. The mode control technique for cavities realizes a deep and sharp filter shape for Q-band notch filters with 56 and 77 GHz notches, respectively. The former filter has an attenuation more than 50 dB at 56.05 GHz and a bandwidth of 1.1 GHz at -3 dB. The latter filter has an attenuation more than 55 dB at 76.95 GHz and a bandwidth of 1.6 GHz at -3 dB. The electron cyclotron emission imaging and the electron cyclotron emission (ECE) diagnostics for the Q-band implemented a pair of the fabricated filters and demonstrated the ECE measurement successfully in the intense stray radiation from a 56 GHz gyrotron.

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