Arthroscopy has been reported to be an efficient adjunct for the surgical treatment for distal radius fractures (DRF). However, performing wrist arthroscopy during palmar locking plate fixation seems ...to be troublesome. We have developed a surgical technique involving presetting of a palmar locking plate and an arthroscopic reduction technique (PART) of the fracture that can facilitate the procedure. This study is aimed to investigate the effectiveness of our technique in the treatment of DRF.
249 fractures of the distal radius were treated by PART. 205 fractures in 200 patients were followed-up on average for 15 (12-60) months. There were 46 men and 154 women with an average age of 62 (16-85) years. According to the AO/ASIF fracture classification system there were 51 extra-articular fractures, and 154 intra-articular fractures. Scapholunate interosseous ligament injuries were classified according to Geissler and tears of the triangular fibrocartilage complex according to Abe. On arthroscopic inspection, residual intra-articular fragment dislocation after reduction under fluoroscopy was evaluated. Final evaluation included a radiological examination, measurements of wrist and forearm motion, grip strength, the Mayo modified wrist score (MMWS), and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire.
On arthroscopic inspection, intraarticular dislocations were found to be residual in 22.7%, even if reduction seemed to have been achieved when viewed by fluoroscopy. Scapholunate interosseous ligament tears were recognized in 29.8%, and triangular fibrocartilage complex tears in 62.4%. The mean palmar tilt was 5.7 (-10 to 16)°, radial inclination 26.0 (18-31)°, and ulnar variance 0.1 (-2 to 5) mm. The mean extension of the wrist was 71 (50-85)°, and the mean flexion was 62 (40-79)°. The mean pronation of the forearm was 87.5 (70-90)°, and the mean supination was 89.1 (75-95)°. The mean grip strength was 90.0% (31-133%) of the opposite side. According to the MMWS there were 156 excellent, 47 good, and 2 fair results. The mean DASH score was 3.9.
The palmar locking plate in combination with arthroscopic reduction technique (PART) leads to good and excellent results. It can be recommended for all fractures of the distal radius needing operative treatment. Arthroscopic reduction of intra-articular fragments is superior to reduction under fluoroscopy. PART allows also the detection of intra-articular soft tissue lesions such as scapholunate ligament tears and injuries of the triangular fibrocartilage complex.
To evaluate the association between rates of progressive loss in different regions of the visual field and longitudinal changes in quality of life (QoL).
Prospective, observational cohort study.
The ...study included 236 patients with glaucomatous visual field loss followed for an average of 4.3±1.5 years.
All subjects had the 25-item National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25) performed annually and standard automated perimetry (SAP) at 6-month intervals. Subjects were included if they had a minimum of 2 NEI VFQ-25 and 5 SAP tests during follow-up. Evaluation of rates of visual field change was performed using 4 different regions (central inferior, central superior, peripheral inferior, and peripheral superior) of the integrated binocular visual field. The association between change in NEI VFQ-25 Rasch-calibrated scores and change in different regions of the visual field was investigated with a joint multivariable longitudinal linear mixed model.
The relationship between change in QoL scores and change of mean sensitivity in different regions of the visual field.
There was a significant correlation between change in the NEI VFQ-25 Rasch scores during follow-up and change in different regions of the visual field. Each 1 decibel (dB)/year change in binocular mean sensitivity of the central inferior area was associated with a decline of 2.6 units/year in the NEI VFQ-25 scores (R(2) = 35%; P < 0.001). Corresponding associations with change in QoL scores for the peripheral inferior, central superior, and peripheral superior areas of the visual field had R(2) values of 30%, 24%, and 19%, respectively. The association for the central inferior visual field area was statistically significantly stronger than those of the central superior area (P = 0.011) and peripheral superior area (P = 0.001), but not the peripheral inferior area (P = 0.171). Greater declines in NEI VFQ-25 scores were also seen in patients who had worse visual field sensitivity at baseline.
Progressive decline in sensitivity in the central inferior area of the visual field had the strongest association with longitudinal decline in QoL of patients with glaucoma.
Abstract
The scientific and technical advances continue to support novel discoveries by allowing scientists to acquire new insights into the structure and properties of matter using new tools and ...sources. Notably, neutrons are among the most valuable sources in providing such a capability. At the Institute of Laser Engineering, Osaka, the first steps are taken towards the development of a table-top laser-driven neutron source, capable of producing a wide range of energies with high brightness and temporal resolution. By employing a pure hydrogen moderator, maintained at cryogenic temperature, a cold neutron (
$$\le 25\hbox { meV}$$
≤
25
meV
) flux of
$$\sim 2\times 10^3\hbox { n/cm}^2$$
∼
2
×
10
3
n/cm
2
/pulse was measured at the proximity of the moderator exit surface. The beam duration of hundreds of ns to tens of
$$\upmu \hbox {s}$$
μ
s
is evaluated for neutron energies ranging from 100s keV down to meV via Monte-Carlo techniques. Presently, with the upcoming J-EPoCH high repetition rate laser at Osaka University, a cold neutron flux in orders of
$$\sim 1\times 10^{9}\hbox { n/cm}^2/\hbox {s}$$
∼
1
×
10
9
n/cm
2
/
s
is expected to be delivered at the moderator in a compact beamline.
Increasing the laser energy absorption into energetic particle beams represents a longstanding quest in intense laser-plasma physics. During the interaction with matter, part of the laser energy is ...converted into relativistic electron beams, which are the origin of secondary sources of energetic ions, γ-rays and neutrons. Here we experimentally demonstrate that using multiple coherent laser beamlets spatially and temporally overlapped, thus producing an interference pattern in the laser focus, significantly improves the laser energy conversion efficiency into hot electrons, compared to one beam with the same energy and nominal intensity as the four beamlets combined. Two-dimensional particle-in-cell simulations support the experimental results, suggesting that beamlet interference pattern induces a periodical shaping of the critical density, ultimately playing a key-role in enhancing the laser-to-electron energy conversion efficiency. This method is rather insensitive to laser pulse contrast and duration, making this approach robust and suitable to many existing facilities.
High tensile strength steel sheets having different strengths were joined with an aluminium alloy sheet by a self-piercing rivet. In the joining, a conventional rivet and die used for aluminium alloy ...sheets were employed in order to have the versatility for various steel sheets. The effects of the flow stress of the high strength steel sheets and the combination of the sheets on the joinability of the sheets were investigated by finite element simulation and an experiment. As the tensile strength of the high strength steel sheet increases, the interlock for the upper high strength steel sheet increases due to the increase in flaring during the driving through the upper sheet, whereas that for the lower high strength steel sheet decreases. The joint strength for the lower high strength steel is comparatively smaller than that for the upper high strength steel sheet. It was found that the high tensile strength steel sheets below 590
MPa were fully joined with the aluminium alloy sheet even with the conventional self-piercing rivet and die.
•Deep drawability is improved with coating of die.•VC-coated die is suitable for deep drawing of ultra-high strength steel sheets.•TiN-coated die is not suitable for deep drawing of ultra-high ...strength steel sheets.•Quality of deep drawn sheets is influenced by the drawing conditions.
The formability of deep drawn ultra-high strength steel sheets in dies coated with either titanium nitride (TiN) or Vanadium carbide (VC) at different drawing speeds and ironing ratios was investigated. TiN was deposited via chemical vapour deposition and physical vapour deposition (PVD) while thermal diffusion was used for VC deposition. In non-coated dies, seizure occurred on both surfaces of the die and the side wall of the drawn cup irrespective of the deep drawing conditions. The deep drawability is improved with coating of die. Whereas in coated dies, seizure became significant only during deep drawing extreme conditions of 120mm/s for TiN-coated dies; and this was prevented in VC-coated dies across all drawing conditions. The VC-coated die was suitable for deep drawing of ultra-high strength steel sheets. The delayed fractured observed in the ultra-high strength steel cups occurred for a large amount of ironing ratio and drawing speeds; and this can be prevented by appropriate heat treatment.
Neutrons are powerful tools for investigating the structure and properties of materials used in science and technology. Recently, laser-driven neutron sources (LDNS) have attracted the attention of ...different communities, from science to industry, in a variety of applications, including radiography, spectroscopy, security, and medicine. However, the laser-driven ion acceleration mechanism for neutron generation and for establishing the scaling law on the neutron yield is essential to improve the feasibility of LDNS. In this paper, we report the mechanism that accelerates ions with spectra suitable for neutron generation. We show that the neutron yield increases with the fourth power of the laser intensity, resulting in the neutron generation of3×1011in4πat a maximum, with1.1×1019Wcm−2, 900 J, 1.5 ps lasers. By installing a “hand-size” moderator, which is specially designed for the LDNS, it is demonstrated that the efficient generation of epithermal (0.1–100 eV) neutrons enables the single-shot analysis of composite materials by neutron resonance transmission analysis (NRTA). We achieve the energy resolution of 2.3% for 5.19-eV neutrons 1.8 m downstream of the LDNS. This leads to the analysis of elements and isotopes within sub-μstimes and allows for high-speed nondestructive inspection.
Abstract
Optical generation of kilo-tesla scale magnetic fields enables prospective technologies and fundamental studies with unprecedentedly high magnetic field energy density. A question is the ...optimal configuration of proposed setups, where plenty of physical phenomena accompany the generation and complicate both theoretical studies and experimental realizations. Short laser drivers seem more suitable in many applications, though the process is tangled by an intrinsic transient nature. In this work, an artificial neural network is engaged for unravelling main features of the magnetic field excited with a picosecond laser pulse. The trained neural network acquires an ability to read the magnetic field values from experimental data, extremely facilitating interpretation of the experimental results. The conclusion is that the short sub-picosecond laser pulse may generate a quasi-stationary magnetic field structure living on a hundred picosecond time scale, when the induced current forms a closed circuit.
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