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We simultaneously observed both the fast proton generation and terahertz (THz) radiation in the laser pulse interaction with a thin-foil target. The maximum proton energy of ∼2.3 MeV and an intense THz radiation were observed at the pulse duration of ∼30 fs. We also measured the proton beam and UV harmonics from a thin-foil target by changing the laser pulse duration. In the case of the ∼500 fs, peaks of UV harmonics up to fourth order appeared. This unique combination of the multiple beams will provide useful applications such as pump-probe experiments.

We demonstrate laser-ion acceleration from a near-critical density plasma, using amplified spontaneous emission (ASE) to convert a solid foil target into a lower-density target. In order to investigate the target density dependence of the laser-ion acceleration, two cases were investigated for which the ASE intensity differed by three orders of magnitude. In the low contrast case the beam centre for higher energy protons is shifted closer to the laser-propagation direction of 45○, while the centre of lower-energy beam remains near the target normal direction. We show that a near-critical density plasma can be used to control proton beam direction based on its energy.

We have succeeded to compress the energy spread of a laser-produced proton beam to 1.6% at FWHM by an RF electric field synchronous to the pulse laser. Protons generated by this laser originally had a continuous energy spectrum with no peaks. Radial focusing and defocusing effects caused by the transverse component of the RF field were also observed. Concerning these effects, we simulated the energy spectra from the calculated value of the electric field by POISSON; the simulation could almost reproduce the experimental results. By applying this beam as an injection beam of a synchrotron, a compact acceleration system for particle cancer therapy is expected to be realized.

We demonstrate a high-contrast, high-intensity double chirped-pulse amplification (CPA) Ti:sapphire laser system using an optical parametric chirped-pulse (OPCPA) pre- amplifier. By injecting cleaned microjoule seed pulses into the OPCPA, a temporal contrast greater than 10 10 within picosecond times before the main femtosecond pulse is demonstrated with an output pulse energy of 1.7 J and a pulse duration of 30 fs, corresponding to a peak power of 60 TW at a 10 Hz repetition rate. This system uses a cryogenically-cooled Ti:sapphire final amplifier and generates focused peak intensities in excess of 10 20 W/cm 2 .

A dependence of cutoff proton kinetic energy on laser prepulse duration has been observed. Amplified spontaneous emission pedestal duration is controlled by a fast electrooptic pulse slicer where the rise time is estimated to be 130 ps. We demonstrate a new correlated spectral technique for determining this rise time using a stretched frequency-chirped pulse.

A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Ti:sapphire laser. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of ~10 µm, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.

A total of 13 patients with acute Tossy grade III acromioclavicular (AC) dislocation were treated operatively: 6 patients by the Neviaser method, 4 patients by the Cadenat method, and 3 patients by closed reduction and Kirschner wire fixation, between April 1994 and November 2001. The functional results of the AC joint were assessed with the 100 point scale of Kawabe et al. The mean total points of the scale were 87.4, 76.2, and 85.4, with the Neviaser method, Cadenat method, and closed reduction and Kirschner wire fixation, respectively. In conclusion, there were no significant differences in the functional results between these three operative methods.

High intensity laser-plasma interaction has attracted considerable interest for a number of years. The laser-plasma interaction is accompanied by generation of various charged particle beams, such as high-energy proton and ions with high charge to mass ratio (Q/M; same as multi-charged ions). Results of simultaneous novel measurements of electron-induced photonuclear neutrons (photoneutron), which are a diagnostic of the laser-plasma interaction, are proposed to use for optimization of the laser-plasma ion generation. The proposed method is demonstrated by the laser irradiation with the intensity of 1 × 10(21) W/cm(2) on the metal foil target. The photoneutrons are measured by using NE213 liquid scintillation detectors. Heavy-ion signal is registered with the CR-39 track detector simultaneously. The measured signals of the electron-induced photoneutrons are well reproduced by using the Particle and Heavy Ion Transport code System. The results obtained provide useful approach for analyzing the various laser based ion beams.

Experimental demonstration of multi-charged heavy ion acceleration from the interaction between the ultra-intense short pulse laser system and the metal target is presented. Al ions are accelerated up to 12 MeV/u (324 MeV total energy). To our knowledge, this is far the highest energy ever reported for the case of acceleration of the heavy ions produced by the10 J laser energy of 200 TW class Ti:sapphire laser system. Adding to that, thanks to the extraordinary high intensity laser field of ∼10(21) W cm(-2), the accelerated ions are almost fully stripped, having high charge to mass ratio (Q/M).

Nine fractures percutaneously fixed with straight Kirschner wires threaded at the tip were found to heal well. However in some, the end of the Kirschner wires backed out before completion of bone union. Four fractures fixed with curved Kirschner wires from small skin incision also healed well. But, in two, the tip of the Kirschner wires cut out from the humeral head before completion of bone union. These problems happened in severely osteoporotic cases.Functional results are believed not to deteriorate with the local problems mentioned above, but depend on preinjury activivies, pre-and/or postoperative genereal complications, and motivation for the rehabilitation of the patients.

We have demonstrated highly efficient broadband amplification by an optical parametric chirped pulse amplifier (OPCPA) system that uses high energy seed pulses. The OPCPA consists of three type I B-barium borate (BBO) crystals pumped by a Q-switched Nd:YAG laser. We successfully amplified the microjoule level seed pulses to 78 mJ with a pump-to-signal optical conversion efficiency of 26% at a 10 Hz repetition rate. To our knowledge these results represent the most optically efficient OPCPA to date pumped by a typical Q-switched laser.

Two cases of forearm tissue defects were treated by free vascularized musculocutaneous flap or free vascularized muscle flap transplantation. Case 1 who received a press injury and had an infection in the left forearm suffered complete median nerve palsy. Free vascularized rectus abdominis flap (9×12cm) was transplanted following debriedement of infected tissue. Thirteen months later, this patient has returned to his original job. Case 2 received two operations against soft tissue sarcoma in the right forearm before she visited our hospital. Tissue defect following wide recection of synovial sarcoma in the right forearm was reconstructed by free vascularized latissimus dorsi musculocutaneous flap (24×15cm). The right hand of this patient is useful with a simple elbow orthosis seven months after the last operation.

Two important fractures of the trapeziometacarpal joint are Bennett's fracture and Rolando's fracture. There are many treatments for these fractures, amongst which closed reduction and percutaneous pinning have become the treatment of choice for these fractures these days.We report on our treatment with an external fixator in 7 cases of Bennett's fracture and Rolando's fracture between 1995 and 1998. Four cases are Bennett's fractures and 3 cases are Rolando's. All cases could be followed, and the follow-up period varied from 6 months to 2 years.The policy of our department has been towards the reconstruction of the articular surface with closed reduction applying external fixator. If the fracture is not reducible, an open reduction is recommended.Clinical results were assessed using Saito's demerit point system for Bennett's fracture and roentgenographic findings were analysed. There were 6 excellent, 1 good, and no fair or poor. Roentgenographically, there was only 1 case with shortening of the metacarpal shaft. By using an external fixator, reduction can be maintained without difficulty.

近年，脳・心血管障害の為に抗凝固薬内服中の患者が増加している．脊椎手術に関して，術中出血・術後血腫等の危惧にて，術前の内服中止が一般的である．当科ではここ数年，年間1～2人の周術期脳梗塞を経験した為2005年2月から内服継続で脊椎手術を行っている．これ以前の脊椎手術447例と以後の424例について危険因子・出血量（術中・術後）・ドレーン留置期間・術後合併症等を比較した．内服歴のないA群・内服継続B群・内服中止C群で比較すると，B・C群は高齢で生活習慣病が多く，脳・心血管障害の既往が有意に多かった．ドレーン留置期間は変わらず，B群で術中出血が約50cc，術後出血が約100cc多かった．周術期脳梗塞はB群には認めず，術後胸痛発作は各群に認められた．術後血腫による再手術は無かった．脊椎手術でも合併症の多い高齢者が増えており，周術期の脳・心血管障害は重篤である．神経内科・循環器科は周術期抗凝固療法の継続を推奨しており再考の必要がある．

10 years ago, a 47 year old woman suffering from quadriplegia for 30 years sustained bilateral elbow neuropathic arthropathy, and thus syringo-peritoneal shunting for syringomyelia, and relief of the elbow from load by the use of an electrically-powered wheel chair were carried out. 10 years later, review of the woman revealed almost no aggravation of quadriplegia and elbow arthropathy.A 69 year old man suffering from quadriplegia for 29 years sustained bilateral elbow neuropathic arthropathy with syringomyelia, and thus synovectomy, debridement, and closure of the fistula followed by bracing were carried out for the left worse elbow. 3 months after surgery, no inflammation nor remarkable effusion was seen.

We reviewed the results of 10 patients (10 hips) after revision total hip arthroplasty with use of cement for 6 aseptic loosenings, 2 septic loosenings, 1 femoral shaft fracture, and 1 component fracture. Three patients were men and 7 women. Their mean age was 73 years (range 56 to 86). The mean duration from primary operation to revision was 64 months (range 13 to 180). The mean duration of follow-up was 41 months (range 8 to 84). The mean J. O. A. score significantly improved from 41.9 points to 70.7 points at the time of the latest follow-up examination.

We measured high-resolution spectra of high-order harmonics generated in the interaction of relativistic-irradiance (>1018 W/cm2) multi-terawatt femtosecond lasers with gas jets. The spectra exhibit very fine structures on the sub-eV scale, indicating temporal coherence of a few tens of femtoseconds.

Forty-five patients who had surgery to repair a full thickness rotator cuff tear (45 shoulders) were followed for an average of 35.5 months (range, 6 to 72). Thirty were men and 15 women. The average age of the patients was 56 years (range, 31 to 67 years). After anterior acromioplasty, tendon to bone repair was accomplished in 37 shoulders, tendon to tendon repair in three, and repair with Teflon felt in five. It was necessary to transfer the subscapularis in three shoulders and to advance supraspinatus in one shoulder. Generally patients were placed in abduction braces to hold the shoulder in 60° to 90° flexion and abduction after the operation. Patients received passive ROM (range of motion) exercises to the shoulder for the initial 4 to 6 weeks. This therapy was followed by active assisted ROM and finally by active ROM as strength was regained. Using JOA score, excellent or good results were achieved in 93% of the patients with small or medium tears (5cm≥, N=29). However, excellent or good results were achieved in 70% of large or massive tears (5cm

We demonstrate the temporal contrast enhancement in a petawatt-class Ti:sapphire chirped-pulse amplification (CPA) laser system. An extra saturable absorber, introduced downstream after a low-gain optical parametric chirped-pulse amplification (OPCPA) preamplifier, has improved the temporal contrast in the system to 1.4×10(12) on the subnanosecond time scale at 70 TW power level. We have achieved 28 J of uncompressed broadband output energy with this system, indicating the potential for reaching peak powers near 600 TW.

Five patients with axillary nerve injuries and four patients with suprascapular nerve entrapment were treated. Diagnosis was confirmed by physical examination and electromyographic studies. As an ancillary test, myelography of the cervical spine and arthrography and MRI of the shoulder joint were performed. Two patients with isolated axillary nerve injuries, in whom the nerve was in continuity, were treated by neurolysis. Three patients with axillary and suprascapular nerve injuries required nerve grafts. One patient operated upon up to one year two months after trauma required trapezius and latissimus dorsi transfer. In three patients with suprascapular nerve entrapment, we performed a release of the transverse scapular ligament and spinoglenoid notch resection. One patient with suprascapular nerve entrapment due to spinoglenoid notch ganglion was treated by removal of the ganglion. All patients achieved good results.

From the interaction between the high-contrast (∼more than 1010) 130 TW Ti:sapphire laser pulse and Stainless Steel-2.5 um-thick tape target, proton beam with energies up to 23 MeV with the conversion efficiency of ∼1% is obtained. After plasma mirror installation for contrast improvement, from the interaction between the 30 TW laser pulse and thin-foil target installed on the target holder with the hole whose shape is associated with the design of the well-known Wehnelt electrode of electron-gun, a 7 MeV intense proton beam is controlled dynamically and energy selected by the self-induced quasi-static electric field on the target holder. From the highly divergent beam having continuous spectrum, which are the typical features of the laser-driven proton beams from the interactions between the short-pulse laser and solid target, the spatial distribution of 7 MeV proton bunch is well manipulated to be focused to an small spots with an angular distribution of ∼10 mrad. The number of protons included in the bunch is >106.

A laser-driven repetition-rated 1.9 MeV proton beam line composed of permanent quadrupole magnets (PMQs), a radio frequency (rf) phase rotation cavity, and a tunable monochromator is developed to evaluate and to test the simulation of laser-accelerated proton beam transport through an integrated system for the first time. In addition, the proton spectral modulation and focusing behavior of the rf phase rotation cavity device is monitored with input from a PMQ triplet. In the 1.9 MeV region we observe very weak proton defocusing by the phase rotation cavity. The final transmitted bunch duration and transverse profile are well predicted by the PARMILA particle transport code. The transmitted proton beam duration of 6 ns corresponds to an energy spread near 5% for which the transport efficiency is simulated to be 10%. The predictive capability of PARMILA suggests that it can be useful in the design of future higher energy transport beam lines as part of an integrated laser-driven ion accelerator system.

We have developed a femtosecond high-intensity laser system that combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric CPA (OPCPA) techniques and produces more than 30 J broadband output energy, indicating the potential for achieving peak powers in excess of 500 TW. With a cleaned high-energy seeded OPCPA preamplifier as a front end in the system, for the compressed pulse without pumping the final amplifier, we found that the temporal contrast in this system exceeds 10(10) on the subnanosecond time scales, and is near 10(12) on the nanosecond time scale prior to the peak of the main femtosecond pulse. Using diffractive optical elements for beam homogenization of a 100 J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with a near-perfect top-hat-like intensity distribution.

We report the demonstration of over 30-J of uncompressed broadband energy, indicating the potential peak power in excess of 500-TW with high temporal-contrast around 1011 and a flat-toped spatial-profile with an ∼80 % filling factor.

The dynamics of a MeV laser-produced proton beam affected by a radio frequency (rf) electric field has been studied. The proton beam was emitted normal to the rear surface of a thin polyimide target irradiated with an ultrashort pulsed laser with a power density of $4\ifmmode\times\else\texttimes\fi{}{10}^{18}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$. The energy spread was compressed to less than 11% at the full width at half maximum (FWHM) by an rf field. Focusing and defocusing effects of the transverse direction were also observed. These effects were analyzed and reproduced by Monte Carlo simulations. The simulation results show that the transversely focused protons had a broad continuous spectrum, while the peaks in the proton spectrum were defocused. Based on this new information, we propose that elimination of the continuous energy component of laser-produced protons is possible by utilizing a focal length difference between the continuous spectral protons and the protons included in the spectral peak.

We describe results of experiments on laser-driven proton acceleration and corresponding laser-plasma diagnostics performed with the multi-10-TW J-KAREN laser. The laser consists of a high-pulse-energy oscillator, saturable absorber, stretcher, Optical Parametric Chirped Pulse Amplifier (OPCPA), two 4-pass Ti:Sapphire amplifiers, and compressor. The final amplifier is cryogenically cooled down to 100 K to avoid thermal lensing. The laser provides ~30 fs, ~ 1 J, high-contrast pulses with the nanosecond contrast better than 1010. The peak intensity is 1020 W/cm2 with the 3- 4 μm focal spot. Using few-μm tape and sub-μm ribbon targets we produced protons with the energies up to 4 MeV. The tape target and repetitive laser operation allowed achieving proton acceleration at 1 Hz. We found significant differences in stability and angular distribution of proton beam in high-contrast and normal-contrast modes. The plasma diagnostics included interferometry and measurement of the target reflectivity. The latter provides convenient diagnostics of the laser contrast in the ion acceleration, harmonics generation, and other laser - solid target interaction experiments.

We demonstrate the generation of greater than 1010 temporal contrast with over 1020 W/cm2 peak intensity pulses at a 10 Hz repetition rate from a Ti:sapphire chirped‐pulse amplification (CPA) laser system utilizing double CPA, optical parametric chirped‐pulse amplification (OPCPA), and cryogenic‐cooling techniques. We also successfully produce uncompressed output pulse energy exceeding 30 J, indicating potential for peak power at the 500 TW level.

The authors describe firstly the lasers for high intensity physics experiments at JAEA including J-KAREN and JLITE-X lasers which can deliver 00TW and 0TW laser power, respectively. Secondly the authors describe demonstration of flying mirror technique which will become a new technique to make a coherent tunable x-ray source. Thirdly a femto-second laser driven incoherent soft x-ray source and its imaging applications for nano-structures are described. The th topic includes femto-second laser driven multiple quantum beam generation and its applications using a laser driven thin foil target.

We report the first high-contrast, high-intense Ti:sapphire chirped-pulse amplification laser system incorporating a nonlinear pre-amplifier based on an optical parametric chirped-pulse amplification for use in experiments where relativistic effects dominate the physics.

We demonstrate a high‐contrast, 80‐TW, 19‐fs Ti:sapphire chirped‐pulse amplification laser system that incorporates a nonlinear pre‐amplifier based on optical parametric chirped‐pulse amplifier (OPCPA) for use in experiments where relativistic effects dominate the physics. With the OPCPA, the background temporal contrast is significantly improved to ∼10−9 in a few picoseconds interval prior to the main laser pulse. By cooling the Ti:sapphire crystal in the final amplifier down to 77 K, the chirped‐pulses are amplified to 2.9 J at 10 Hz repetition rate without thermal lensing effect.

Despite the progress of antibiotics, the management of osteomyelitis involving composite bone and soft tissue defects remains a major problem for surgeons.We performed a free composite serratus anterior and rib flap for a case of osteomyelitis of calcaneus. The flap has survived in its entirety. The patient was able to walk without any assistance three months after the operation, and bony union was achieved eight months after operation. He did not complain of any inconvenience in using his upper arm although scapular winging was noted, and returned to his original job as a cook four months after operation.Free composite serratus anterior and rib flap is useful for one-stage reconstruction of extensive composite bone and soft tissue defects.

We describe a compact, reliable, high-power, and high-contrast noncollinear optical parametric chirped-pulse amplifier system. With a broadband Ti:sapphire oscillator and grating-based stretching and compression, the chirped pulses are amplified from 0.1 nJ to 122 mJ in type I beta-barium borate optical parametric chirped-pulse amplifiers with a total gain of over 10(9) at 10 Hz repetition rate. Pulse compression down to 19-fs duration achieved after amplification indicates a peak power of 3.2 TW at an average power of 0.62 W. The prepulse contrast is measured to be less than 10(-8) on picosecond time scales.

Spontaneous rupture of the extensor digitorum communis is rare and poorly understood. We experienced 9 cases of extensor digitorum communis tendon rupture caused by overuse of hand.Mechanical attrition at the distal edge of the extensor retinaculum was considered the main cause. Most of the cases were treated by tendon transfer and end-to-side suture, and tendon graft was performed on cases with multiple tendon ruptures.

We have reported that thoracis outlet syndrome (TOS) results not only from neurovascular compression but also from stretching and defined any such patients as brachial plexus stretching type of TOS. In 1984, T. R. Swift described that droopy shoulder syndrome (DSS) also results from brachial plexus stretching, and that in all patients with DSS, because of their characteristic features, the second thoracic or lower vertebrae visible above their shoulders on lateral view of cervical spine X-rays are one of the diagnostic criteria for DSS. Therefore, we studied the relationship between brachial plexus stretching and the lateral view of cervical spine X-rays.We examined 40 cases with brachial plexus stretching type of TOS from 1990 to 1993, in whom a neurography of the brachial plexus had been carried out. In 18 cases, 45% of them, lateral view of cervical spine X-rays demonstrated that the secone thoracic or lower vertebrae was above the level of the shoulders. Patients with brachial plexus stretching type of TOS had a “long neck”. In 1990 Y. Kataoka reported that all patients whose second thoracic or lower vertebrae were visible above their shoulders on lateral view of cervical spine X-rays had no symptoms induced by brachial plexus stretch. We found that this finding on X-rays did not always represent brachial plexus stretching and its symptoms.

We treated two cases with septic arthritis of the shoulder joint. Synovectomy and continuous irrigation-suction treatment was carried out using arthroscopy. Passive ROM excercise was started just after operation. Our procedures were so effective that they had good function without contracture. We confirmed that the early treatment with the use of arthroscopy is very useful for the septic arthritis.

We are investigating the laser driven charged particle acceleration to develop a particle accelerator using an intense lasers with a focused intensity of >>1018 W/cm2. To monitor proton energy spectra as well as plasma parameters under the repetitive operation, we are using real time detectors. The proton energy of ~MeV is stably obtained for applications.

L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl- 2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl hydrogen phosphate] potassium salt (EPC-K1), a phosphate diester of alpha-tocopherol and ascorbic acid, is a potent antioxidant. We examined the effects of EPC-K1 on ischemia-reperfusion injury in the skeletal muscle of rats, using an ischemic revascularized hind limb model. Warm ischemia (25 degrees C), produced by vascular pedicle clamping, was sustained for 4 hours. After 24 hours of reperfusion, skeletal muscle injury was evaluated in 2 groups: one group treated by intravenous injection of EPC-K1 (10 mg/kg) prior to ischemia, and a group of controls. The EPC-K1-treated group showed a statistically significant amelioration in the reduction of the isometric muscle contraction, inhibition of the elevation of the muscle wet- to dry-weight ratio, limitation of the muscle level of thiobarbituric acid reactive substances and the serum levels of creatine phosphokinase, lactate dehydrogenase and mitochondrial glutamic oxaloacetic transaminase, and reduction of the extent of muscle injury according to the histological findings. These observations indicate that EPC-K1 acted effectively on ischemia-reperfusion injury in the rat skeletal muscle and thereby improved muscle function.

The conjugation of horseradish peroxidase with wheat germ agglutinin was used to identify the effect on retrograde axonal transport of stretching the rat sciatic nerve indirectly by 10% and 20% femoral lengthening with a unilateral external fixator. To investigate the relationship between retrograde axonal transport and blood flow in the stretched nerve, nerve blood flow in the sciatic nerve was measured by a hydrogen washout technique. At 11% strain (20% femoral lengthening), the numbers of horseradish peroxidase-labelled motor neuron cells and nerve blood flow had decreased by 43% and 50%, respectively. Histological examination demonstrated ischaemic changes, but not mechanical damage. However, at 6% strain (10% femoral lengthening) there were no significant abnormalities. These findings suggest that the inhibition of retrograde axonal transport can be induced by acute stretching of the peripheral nerve and that circulatory disturbance is the main cause of the inhibition of retrograde axonal transport at the low strain.

The precision of the time-of-flight method for measuring proton spectra is confirmed by the activation method using a 7Li(p,n)7Be nuclear reaction. The proton beam driven by a repetitive high-intensity laser is utilized to induce the nuclear reaction. The activity measured by direct gamma-ray measurement after 1912 proton beam shots at 1 Hz is 1.7±0.2 Bq. This is in accordance with the activity of 1.6±0.2 Bq obtained from the shot-to-shot proton energy distribution measured using the time-of-flight detector.

The laser contrast ratio within picosecond timescales is one of the important parameters for laser acceleration. For a high laser contrast ratio, a 140 MeV monoenergetic electron beam with a charge of 44 pC is obtained by using a 20 TW Ti:sapphire laser. For a low laser contrast ratio, a low quality electron beam or no electron beam is generated, because the pre-pulse blows out plasma electrons and puts the plasma into disorder before the main pulse interacts with the plasma. The laser contrast ratio should be high enough in order to generate a high quality electron beam with a large amount of charge.