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ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗ, In this report, an 8-month-old calf (crossbred, Holstein × Japanese Black) developed fever and accompanied abomasum displacement. Blood chemical test showed remarkably high values of white blood cell count and heteromorphic lymphocytes. In pathological appraisal, enlarged splenomegaly and swelling of the lymph nodes were observed. Histopathological examination revealed invasion of tumor cells derived from B1 cells into systemic lymph nodes, liver and spleen. The provirus loads of bovine leukemia virus (BLV) was 1,439 copies per 10 ng DNA by using real time PCR. In conclusion, this case was diagnosed as bovine leukemia caused by BLV infection with a huge splenomegaly.

We have recently developed a thin-type Cu clad stabilized Nb3Al flat-wire which can be more densely wound into a coil. Using this flat-wire we have upgraded an existing 14 T Nb-Ti/Nb3Sn magnet with a ? 30 mm clear bore, by replacing the inner coil, to a compact 15 T Nb-Ti/Nb3Al magnet. The Nb3Al inner coil was connected in series with the Nb-Ti outer coil and excited by a common power supply to generate 15 T in a ? 40 mm clear bore, after a training of Nb-Ti coil. The resultant higher field and wider space will be used for critical current measurements of various superconducting wires being developed in NIMS.

Rapid heating, quenching and transformation (RHQT)-processed Nb3Al wires possess better strain tolerance than Nb3Sn wires. However, RHQT-processed Nb3Al wires so far developed show lower non-copper critical current density (Jc) than recently developed high-Jc Nb3Sn wires in the field range of 12-15 T. Therefore, the development of Nb3Al wires having enhancing Jc in this field range is a major concern for accelerator magnet designers. Among a number of fabrication parameters that might affect Jc properties, we analysed the effect of thickness of Al and Nb foils in the jelly-roll-shaped filaments embedded in the precursor wires. Mechanical and superconducting properties of these wires with various Al-foil thicknesses in the filaments were investigated.

We have been developing rapid heating, quenching and transformation (RHQT) processed Nb3Al wires for next-generation accelerator magnets that require magnetic fields between 12 and 17 T. However, it has recently been found that the conventional Nb-matrix wire shows a rather strong magnetic instability at low fields. Taking this into consideration, we have begun developing Ta-matrix Nb3Al wires. We have fabricated a precursor wire with a Ta-matrix volume fraction of 0.8, and the mechanical properties of the RHQ-processed wire were examined. The effects of the RHQ condition and the area reduction (AR) after RHQ on the critical current density (J c) , and magnetization of the wire have also been examined. This paper describes the properties for the Ta-matrix wire in comparison with those of the Nb-matrix wire.

Nb 3 Al has advantages of better tolerance to strain/stress and a higher critical magnetic field (30 T at 4.2 K) for stoichiometric composition over Nb 3 Sn. The rapid-heating, quenching and transformation annealing (RHQT) process enables to form a stoichiometric Nb 3 Al with fine grain structures via metastable bcc supersaturated-solid-solution. As a result a large critical current density of Nb 3 Al is achieved over the whole range of magnetic fields without trading off the excellent strain tolerance. A long-length of RHQ processing has been established, and a rectangular but Cu stabilized Nb 3 Al strand is about be commercially available for NMR uses. Ag or Cu internal stabilization and Cu ion-plating/electroplating techniques have been also developed to enable the stabilized round wire for accelerator and fusion magnets. Successfully energized test coils that were manufactured with a wind-and-react technique have demonstrated that a long piece of Cu stabilized RHQT Nb 3 Al wire is really available for practical applications.

In the development of RHQT-processed Nb3Al wires for high-field accelerator magnet applications, one of the major objectives is to increase the non-copper critical current density in the field range of 12-15 T. To pursue this goal, a low-matrix- ratio wire was fabricated, and the effects of the RHQ conditions and the area reduction after the RHQ treatment on the properties of the wire were investigated. This paper describes the details and results of this study.

We attempted to reduce the matrix ratio down to 0.5 and 0.25 for RHQT (rapid-heating, quenching and transformation) Nb3Al wires, which is directly related to improvement of the non-Cu Jc. The Ta matrix was chosen to improve the wire strength. It was found that the matrix ratio of 0.25 is too small to carry out RHQ treatment although drawing was possible by using cassette-roller dies (CRDs) as well as conical dies. The reduction of the matrix ratio down to 0.5 can also be achieved. However, the scale-up would make the drawing very difficult. It would be necessary for the scale-up to improve adhesion among the jelly-roll (JR) cores and also the outer Ta sheath in the multi-billet. The RHQ treatment was possible for the wire with a matrix ratio of 0.5. However, it was successful only when the wire diameter was less than 1.13 mm. It is necessary to suppress the experienced bend strain in the operation. The non-Cu Jc was found to be improved by about 20% by the reduction of the matrix ratio, compared to conventional Nb3Al wires.

Recent studies of RHQ-processed Nb3Al wires for future accelerator magnets are presented and discussed. Test wires were prepared with different fabrication parameters, such as the Nb matrix ratio, RHQ current, area reduction ratio of the wire after an RHQ treatment and the 2nd heat treatment condition. Measurements of the critical current density (Jc) and n-value have been performed during the past several years. Recently, we performed the critical temperature (Tc) measurement, and the relationship between Jc and Tc was investigated by an RHQ treatment, a 2nd heat treatment, the Nb matrix ratio, and the area reduction effect.

The authors have been developing the Nb3Al conductors through transformation process, where the Nb3Al phase forms from the BCC (body-centered cubic) Nb(Al) supersaturated solid solution phase; the BCC phase is quenched by rapid-cooling from a temperature around 2000degC. It was reported several times that deformation to the quenched BCC Nb(Al) phase influences the superconducting properties, usually improving . But, the results have not been discussed in detail so far from a metallurgical viewpoint. This work investigates the fundamental relationship between the BCC-deformation, transformation temperature, microstructure and superconducting properties. The transformation temperature is identified by DTA measurement, detecting the release of the free energy between the BCC and the phases. It was found that the transformation temperature has a tendency of monotonic decrease with the deformation. But, the transformation temperature does not seem to go down below a temperature of about 720 degC even by strong deformation. The microstructures observed by FESEM suggests that the grain size is reduced almost proportionally with the deformation. In case of reduction in area of 99%, the grain size is reduced down to about 250 nm from 1.2mum . The increases with deformation, not showing a peak. The Jc of the wire (ME365) with reduction in area of 86% shows the best performance of the wire ever reported. But, at least high-field Jc seems to saturate at a certain value.

To demonstrate the RHQT Nb3Al conductor to be really a candidate for a high-field magnet, we have fabricated 1 km-class Cu stabilized RHQT Nb3Al flat-wires, manufactured two insert real-sized coils #A and #B, and tested in a superconducting back-up field of 15 T at 4.2 K. Using the coil #A, a thinning of insulator, a winding technique, a new transformation annealing profile in a vacuum with a fast temperature-ramp above 500degC, decarbonization, an impregnation technique used for the Nb3Sn coil were preliminarily checked to be no matter. The coil #B that was wound with a 764 m piece could produce an additional 4.5 T (total 19.5 T) at 4.2 K in a clear bore of 30 mm without any training, when the coil current achieved the Ic of short samples that were simultaneously transformation annealed with the coil #B.

Long Nb3Al strands with copper stabilizer are promising for future high field accelerator magnets. A 1.2 kilometer Nb3Al strand with Cu stabilizer was fabricated at the National Institute for Materials Science in Japan. Using this strand a 30 meter Cu stabilized Nb3Al Rutherford cable was made for the first time by a collaboration of NIMS and Fermilab. The Nb3Al strands extracted from cable with a relatively low packing factor showed almost no Jc degradation. But the extracted strands from the highly compacted cable showed some degradation in both Jc and n value, which may be caused by local separation of the copper stabilizer. Still, its Jc degradation is lower than that of typical Nb3Sn strands. The current limit due to magnetic instability in low field is about 500 A at 4.2 K. The magnetization of the strands, which was measured with balanced coils at 4.2 K, showed large flux jumps, usually around 1.5 T. This value is much larger than the Bc2 (4.2 K) of the Nb matrix, which is around 0.4 Tesla. The magnetic instability of the Nb3Al strand at low field is not completely understood, but it might be explained by the superconducting coupling current through the Nb matrix.

Three kinds of stabilized rapid-heating, quenching and transformation annealing (RHQT) Nb3Al round wires have been developed for nuclear fusion devices; the Ag internally stabilized Nb matrix, the Cu internally stabilized Ta matrix and Cu ion-plated/electroplated wires. The critical current densities Jc of Nb3Al filaments are almost the same as the conventional Cu clad stabilized flat-wire, as long as the Jc is optimized by mechanical deformation of wire after quenching but before the final transformation annealing. To demonstrate the applicability of RHQT Nb3Al wire to nuclear fusion devices, we have trial manufactured a cable-in-conduit conductor (CICC) using the Ag internally stabilized round strands and confirmed the critical current of CICC to be nearly the same with the strain-free designed one.

We observed crack formation in transformation-processed Nb3Al wires at room temperature, the wire being bent with a small clamp fixture with a curvature. The polished cross-section parallel to the longitudinal axis was observed, using a high power optical microscope or a field-emission scanning electron microscope. The bend strain limit for microcrack formation is found, changing the radius of the curvature of the clamp. The bend strain limit was found to be around 0.3% for standard Nb3Al wires. This corresponds to the irreversible tensile strain limit of the Ic characteristics determined with a 0.1 µV cm−1 criterion. Reduction of the barrier thickness should be avoided to keep to the bend strain limit. A new configuration of the Nb3Al wire is demonstrated to improve the bend strain limit. The filament is divided into segments in the transverse cross-section. The wire is fabricated by a double-stacking method. The bend strain limit is enhanced to about 0.85% for the wire surface; the equivalent strain of the outermost filament location is about 0.66%. A simple react and wind test for this wire was performed, where the wire experienced 0.86% bend strain. The degradation of Jc was found to be very small.

We have produced so far about a 400 m length of Cu stabilized RHQT (rapid-heating, quenching and transformation) Nb3Al flat-wire using a small-sized multi-billet (10 kg). Although our goal is to make a 2.5 km unit length of Cu cladding flat-wire for high-field NMR uses, an attempt was made to fabricate a 1 km class unit-length of conductor as a milestone of commercialization. A long-length of precursor wire over 2.5 km was prepared by using a large-sized multi-billet (50 kg). A 1.3 km length RHQ operation by using a newly installed large-scale RHQ apparatus was performed and then a km-class length Cu cladded flat-wire was fabricated to evaluate the uniformity of resultant superconducting characteristics of wire

For the practical conductors with large current capacity, the Cu stabilizer is necessary in order to obtain their fully performance. The most important issue remaining for producing the RHQT (rapid-heating/quenching and transformation)-processed Nb3Al round wire was how to fabricate the Cu stabilizer after the RHQ treatment. We successfully solved this problem and developed the Cu ion-plating technique for fabricating the Cu stabilizer into the RHQT-processed Nb3Al round wires. Although stable Nb oxide layer is formed on the wire surface, the Cu ion-plating can continuously remove them and cover the Cu seed-layer of 1 mum in thickness. Then, the Cu stabilizer can be also fabricated by the Cu electroplating with an appropriate of Cu ratio. The reel-to-reel apparatus of both the Cu ion-plating and electroplating for km-class long-wire have been set up. It was possible to apply the wire drawing by conventional die after the Cu electroplating due to the good bonding between the Cu stabilizer and Nb3Al round wire. This is very attractive advantage for obtaining the severe homogeneity of the wire diameter in long-length. Moreover, in order to obtain large enough RRR, it may be suitable to carry out the following techniques before fabricating the Cu stabilizer, which are an anode-oxidization of wire surface, normal die drawing and easy chemical etching of Nb oxide layer. This additional process is very effective to get much clean and homogeneous surface of the Nb3Al round wires with Nb matrix, and then it has been fabricated the Cu stabilizer without degradation of RRR. RRR of about 200 and non-Cu Jc (4.2K, 15T) of about 1,000 A/mm2 were obtained on the present Cu-stabilized RHQT-processed Nb3Al round wires having 1.0 mm in diameter and about 1.0 of Cu/non-Cu ratio. Nb3Al filament diameter is 30-50 mum at present. These results must be very attractive for application of the high energy physics conductors

The surface of RHQT-processed Nb/sub 3/Al wires with pure Nb matrix are covered by a strong stable Nb oxide surface layer. In order to obtain good mechanical, electrical and thermal bonding between the Cu stabilizer and RHQT-processed Nb/sub 3/Al wires, it is required to destroy the Nb oxide layer on the surface of the wire. We tried to fabricate a thin Cu layer on the surface of the RHQT-processed Nb/sub 3/Al wires through the Cu ion-plating technique. Before electroplating of thick Cu stabilizers, Cu was ion-plated to a thickness of about 1 /spl mu/m. The Cu ion-plated wire showed no folded projections, cracks, or exfoliation of the Cu stabilizer even when the wire was bent through 180 degrees, showing that Cu and the wire were tightly bonded mechanically. This tight bonding between Cu and the wires should be due to the removal of stable Nb oxide layers from the surface of the wire. The V-I characteristic of wires that were ion-plated and then applied with an appropriate amount of Cu by an electroplating showed no quenching, and the wires were able to carry current up to the normal critical current transition. The measured values of recovery current were almost equivalent to the calculated values, showing that the ion-plated Cu/Nb interface had a very tight bond, allowing good electrical and thermal conductivity. In addition, a reel to reel Cu-ion plating apparatus for the long length wires is demonstrated, and Cu ion plating has been successfully carried out on 100 m long RHQT-processed Nb/sub 3/Al wire at present.

Since the RHQT-Nb/sub 3/Al conductor shows excellent superconducting characteristics in high magnetic fields, its application to a 1 GHz NMR insert coil is in particular expected. For such an application, the development of a long-length of RHQT-Nb/sub 3/Al wire is indispensable. However, the unit length of wire achieved was no more than 400 m so far, due to a restricted size of the multi-billet, while about a 2.5 km-length of wire is necessary for the NMR insert coil application. Thus, an attempt was made to produce a 2.5 km-length of precursor wire by using a large-sized billet, and we have succeeded in producing such a long-length of precursor wire (2.6 km) without any breaking of wire during hydrostatic extrusion and subsequent drawing processes.

Nb/sub 3/Al superconductors have shown promising performance compared to Nb/sub 3/Sn conductors when processed by rapid heating/quenching process. Therefore we have started an R&D program of Nb/sub 3/Al conductors for future accelerator magnets. Several test wires of around 0.8 mm diameter, which have relatively small filament (/spl sim/50 micron diameter) and low matrix ratio (/spl sim/1.0), were fabricated, and the heat treatment and area reduction conditions after the rapid quenching process were studied. The highest noncopper J/sub c/ achieved during this study was 1734 A/mm/sup 2/ at 10 T and 4.2 K.

We tried to enlarge a Nb/Al strand dimension to enhance a current capacity of RHQT- Nb/sub 3/Al further. So far good fsRHQ operation could be made by using the strand dimension of less than /spl phi/ 1.35 mm. This time we tried to make RHQ operation by using a Nb/Al rectangular strand of 1.45 /spl times/ 2.2 mm /sup 2/ which is double cross-section area of /spl phi/ 1.35 mm. Bcc phases could be formed even in the large cross-section rectangular strand by RHQ operation. The samples were post-annealed at 800/spl deg/C for transforming into A15. The resultant I/sub c/ and core J/sub c/ were 232.5 A and 130 A/mm /sup 2/ at 4.2 K, 22 T, respectively. These values largely surpassed I/sub c/ of 57.5 A and J/sub c/ of 72.7 A/mm /sup 2/ at 4.2 K, 22 T for the sample which was made by using a conventional /spl phi/ 1.35 mm strand.

We have examined the critical current I/sub c/ and n-values of RHQT processed Nb/sub 3/Al conductors at 4.2 K in a wide range of fields from 14.5 to 25 T in relation to the microstructures obtained. For a point and a tail of Cu-clad rectangular conductor used for a winding, the n-values were determined by fitting the voltage over a taps spacing of 110 or 220 mm to a relationship of V = CI/sup n/, in a range from 10/sup -5/ to 10/sup -4/ V/m. Such n-values were almost the same with each other, indicating the uniformity of a 370 m length of RHQT Nb/sub 3/Al conductor as the I/sub c/ consistency does. The n-value increased monotonously with decreasing a field from 25 T to 18 T, but got saturated to be around 35 at 4.2 K in fields less than 18 T. The n-value at 21 T and 4.2 K, corresponding to 23.5 T and 1.8 K, was about 25, and confirmed to be large enough for NMR uses.

A rapid-heating, quenching and transformation annealing (RHQT) processed Nb3Al conductor has been developed as a promising candidate for a high-resolution NMR superconducting magnet, because of its large critical current densities and n -values. Establishment of a large-billet extrusion, uniform RHQ operation, transformation heat treatment and subsequent Cu-clad stabilizing that are key issues of the long-length processing allows a fabrication of a four hundred meter long RHQT Nb3Al conductor, and thereby its coil application comes in sight with reality. In the present review article, current status of long-length RHQT processed Nb3Al conductors is described.

Recent progress in the internally stabilized rapid-heating, quenching and transformation (RHQT) processed Nb3Al superconductors is described and their various features are compared to those of the externally stabilized Cu clad conductor. Based on the favourable feature that Ag is almost non-reactive to Nb during joule heating, we have succeeded in thinning a diffusion barrier of Nb to less than 5 µm in the finished cross section by adopting an Ag rod jacketed with Nb as a stabilizer module when stacking the subelements. The Ag/non-Ag ratio could be increased to as much as 0.345 by additionally replacing the Nb-centre rod of a jelly roll (JR) with Ag. The superconducting properties of the critical current density, the residual resistance ratio, the magnetoresistance and the n-index in the voltage–current characteristic were studied for both as-quenched and subsequently deformed conductors, finally transformed at 800 °C for 10 h. A loading test of a small coil wound with a 30 m length of internally stabilized RHQT JR conductor has shown the uniformity of the internally stabilized conductor used.

A rapid heating and quenching (RHQ) operation along a long-length of jellyroll Nb/Al precursor over 300 m has been established. The J/sub c/ varies sensitively with the joule-heating current (I/sub RHQ/) that determines the temperature from which a precursor wire is quenched, excluding the "plateau" region where the bcc supersaturated-solid solution (Nb(Al)/sub ss/) only forms. The RHQ operation using such a plateau condition can suppress a scatter of J/sub c/ from point to tail of a long-length of wire. The standard deviation of J/sub c/ (4.2 K) at 21 T along a long-length of wire was about 5%, which was less than the variation of J/sub c/ with I/sub RHQ/ in the plateau region (/spl plusmn/7%). The mechanical deformation process needed when incorporating the Cu stabilizer also plays an important role in ensuring uniform heat treatment of the coil that is wound with a long-length of wire and, hence, large heat capacity. Although a temperature ramp-up rate might differ from place to place in the coil, the deformation processing makes such a ramp-up rate insensitive to these critical parameters. The coils using 300.5 m and 254 m lengths of Cu-clad RHQT JR Nb/sub 3/Al conductor generated additional 2.3 T and 3.2 T in bores of 90.2 mm/spl phi/ and 64.6 mm/spl phi/, respectively, indicating that a long-length of RHQT JR Nb/sub 3/Al conductor can be trustworthy for practical coil applications.

Rapid-heating, quenching, and transformation (RHQT)-processed Nb/sub 3/Al was found to provide high critical current density in high field by Cu addition. There seems to be a difference in the reaction path to A15 between binary Nb/Al (non-Cu-addition) and the Cu added ternary. In the binary case, a Nb/Al composite reacted to form a bcc phase through rapid-heating and quenching (RHQ) treatment and then it was transformed into A15 phase including stacking faults by an 800 /spl deg/C heat treatment. On the other hand, when Cu was added, the composite reacted to form A15 phase including stacking faults through RHQ treatment directly. We fabricated Cu added jelly-roll (JR) Nb/Al wire with various Nb/Al layer thicknesses and compositions and investigated their effect on RHQ process. The Cu added JR wire of Al poor composition for Nb/sub 3/Al stoichiometry showed a behavior similar to the binary. Al rich composition showed a behavior similar to the Cu-addition case. In this work we discussed the Cu addition effect by considering these results.

A Jelly-Roll processed Nb3Al superconductor with excellent superconducting properties has been fabricated by the process of rapid heating, quenching and transformation (RHQT). In order to fabricate a long length of wire with homogeneous superconducting properties, the optimization of the RHQT conditions is particularly important because RHQT conditions determine the final microstructure and superconducting properties. In this paper, we have studied the variation of microstructure and superconducting properties with RHQ and transformation annealing conditions, to determine the optimum processing condition. In the study of the RHQ treatment, we found that the RHQ conditions are divided into four regions according to the joule heating current (IRHQ). In the optimum region, the wire is quenched from the temperature in which a bcc solid solution extends to more than 25 at%Al, and the scatter of critical current density (Jc) after transformation annealing is almost negligible. In the study of the deformation and transformation heat treatment, we have found that the deformation of the supersaturated solid solution improves the resultant superconducting properties, and prevents degradation of superconducting properties that occurs when the temperature ramp-up rate is slow.

Understanding the variation of the superconducting properties as a function of the maximum heat treatment temperature or heating time in jelly-roll Nb/sub 3/Al wire is important for the optimization of the rapid heating conditions. Jelly-roll Nb/sub 3/Al wires with a Nb matrix were ohmically-heated to maximum temperatures ranging from 1900 to 2300 /spl deg/C in vacuum in order to optimize the rapid heating conditions and to investigate the superconducting properties for this transformation method. The diameter of the wire was 0.94 mm. The sample was monitored using a noncontact measurement technique employing a photodiode to measure high temperatures (over 2000 /spl deg/C) during rapid heating. After the surface temperature reached a maximum, the sample was quenched in liquid gallium. The samples were annealed for 10 hours at 800 /spl deg/C after the rapid heating process to transform the bcc-phase to the A15 phase. The superconducting properties including DC magnetization and critical current were explored for various maximum heating temperatures and heating times.

Recently it has been reported that the critical current density of rapid-heating, quenching, and transformation (RHQT) Nb/sub 3/Al superconductor for high fields was vastly improved by Cu additions. That superconductor was made by rod-in-tube (RIT) process. In this work we tried to fabricate a Cu added Nb/sub 3/Al superconductor by jelly-roll (JR) process, which is one of practical processes of Nb/sub 3/Al superconductor fabrication. We fabricated a miniature sized billet and completed the drawing of multifilamentary wire of 1.10 mm in diameter and 41 m in length with no breakage. A sample subjected to the RHQT showed a core J/sub c/ (4.2 K) of 62 A/mm/sup 2/ at 24 T and exceeded the ordinary RHQT Nb/sub 3/Al JR superconductor (without Cu addition) in core J/sub c/ at high fields.

Jelly-roll Nb/sub 3/Al wires with a Nb matrix were ohmically-heated to maximum temperatures ranging from 1800 to 2300/spl deg/C in vacuum in order to optimize the ohmic-heating conditions and to investigate the superconducting properties for this transformation method. The diameters of these wires were 0.80-1.34 mm. Surface temperature at the central point of the sample was measured by a photodiode during rapid ohmic-heating. After the surface temperature reached a maximum, the sample was quenched in liquid gallium. All the samples were annealed at 800/spl deg/C for 3-25 hours after the rapid heating process to transform the bcc-phase to the A15 phase. Critical currents were measured up to 23 T. The samples heated to 2000/spl deg/C showed a maximum critical current density of 64 A/mm/sup 2/ at 20 T. The critical current density decreased with increasing maximum temperature during rapid heating. This paper describes the superconducting properties, the rapid heating conditions and the achievement of high critical current density at high magnetic fields.

A Nb/sub 3/Al superconductor based on jelly-rolled (JR) Nb/Al composites of high performance can be fabricated by rapid-heating and quenching of a wire of such composites with subsequent transformation-annealing to form the Nb/sub 3/Al phase (RHQT process). Since the conductor thereby is heated up to 2000/spl deg/C, far above the melting point of Cu, the Cu stabilizer needs to be externally incorporated by a mechanical-cladding method between quenching and annealing. Such an appropriate deformation promotes the transformation from a disordered bcc phase, and thereby enhances the critical current density J/sub c/. A solenoid coil was fabricated by a wind-and-react method: the Cu-clad conductor (1.61/sup w//spl times/0.71/sup t/ mm/sup 2/) with Al/sub 2/O/sub 3/ yarn insulation was wound into a coil (19.7/40.8/sup /spl phi///spl times/49.7/sup H/ mm), transformed at 800/spl deg/C, and impregnated with beeswax. The resultant coil, while carrying a current of 179 A at 2.1 K in a superconducting back-up field of 21.2 T, generated an additional 1.3 T. The total magnetic field of 22.5 T is the highest record ever for a metallic superconducting coil.

X-ray fluorescent spectroscope-analysis and the method of ratio matching can determine mean directions of sand movement and geochemical classifications of sand grains. The result can also evaluate the physical condition of seabeds in a study area (erosion or accretion). This method is applied to a sedimentation problem in the fishing port of Tsurugiji in Japan and the result is in agreement with the comparison of the change of sea bottom topography measured in different years. The seasonal changes of sand movement on this coast and sedimentation in the port are also investigated.

A Nb/sub 3/Al superconducting conductor based on Jelly-Rolled (JR) Nb/Al composites is fabricated by the rapid-heating and quenching of a wire of such composites with subsequent transformation-annealing to form Nb/sub 3/Al phase. Since the conductor is heated up to 1900/spl deg/C, far above the melting point of Cu, during fabrication, Cu stabilizer cannot directly be included as a basic composite constituent. In the present study, attempts have been made to incorporate the stabilizer to the Nb/sub 3/Al conductor. In a mechanical-cladding method, the as-quenched composite is wrapped longitudinally with a Cu tape, and groove-rolled for mechanical bonding. For internal stabilization, Jelly-Rolled Nb/Al filaments are isolated from the stabilizers by a Nb-filaments barrier and the formation of unwanted Nb-Al-Cu (Ag) compounds are prevented. Ag-stabilizer, little reactive with Nb, can dramatically decrease the Nb-barrier thickness required and allows the increase in the volume fraction of the stabilizer instead.

Magnetic field and temperature dependences of J/sub c/ are measured for rapid quenched and transformed Nb/sub 3/Al multifilamentary wires that were fabricated by the Jelly-roll (JR) and Rod-in-tube (RIT) processes. The J/sub c/ in the transformed JR wire was much larger than that of conventional JR processed wires and also the transformed RIT processed wire. The scaling curve for the J/sub c/-B-T characteristics are given by a temperature scaling law, which agrees well with the experimental results in wide temperature and field ranges. The scaling curve enables us to evaluate J/sub c/ at low magnetic field and low temperature, for instance, J/sub c/ at 10 T, 4.2 K is estimated as 4700 A/mm/sup 2/. The main pinning source would be grain boundaries, because of the small grain size (several tens nm) and its high density.

Continuous rapid heating to about 2, 000°C and rapid quenching to Ga bath, and additional transformation annealing at about 800°C for Nb3Al superconductors, the so-called RHQT (rapid heating, quenching and transformation) process, makes Jc characteristics of the Nb3Al superconductors promising in a high magnetic field. These RHQT processed Nb3Al superconductors show no so-called peak effect, i.e., they show a high Jc even in a lower magnetic field; thus these conductors are expected also to be available around 10T, e.g., for accelerator magnets. So far the jelly-roll-processed RHQT Nb3Al superconductors have been developed for high magnetic field applications, e.g., 1GHz NMR magnet; thus the matrix ratio has been reduced as much as possible to improve the overall Jc. However, excessive reduction of the matrix ratio would be one possible reason for the electromagnetic filament coupling, especially when these conductors are used in a middle magnetic field region around 10T. The increase of the effective filament size degrades the stability, especially in the lower magnetic field, where the Jc becomes much higher. In this paper, the filament coupling for the RHQT-processed jelly-roll Nb3Al multifilamentary superconductors is discussed, referring to the results of the magnetization measurement with a vibrating sample magnetometer and Jc measurement. It was found that the proximity effect might occur even if the designed thickness of the Nb barrier between the filaments was about 10μm. An observation of the cross-sections with SEM shows that this would be due to the partial reduction of the barrier thickness during the RHQ process.

In order to enhance the current carrying capacity, we have developed an improved fabrication process where the wire diameter can be increased from 0.5 to 1.25 mm and the Nb-matrix ratio decreased from 1.5 to 0.52, without degrading the critical current density, J/sub c/, of Nb/sub 3/Al phase. The critical current for a monolithic conductor at 21 T and 4.2 K has now been enhanced to 166 A which used to be 15 A. The compacted-strand-cables were fabricated to investigate feasibility for large-scale application uses. We have found that stranding and flat-rolling the as-quenched Nb/Nb(Al)/sub ss/ composite cause no degradation in J/sub c/. Attempts were made to stabilize the resulting high current conductors.

Matrix metalloproteinase (MMP) plays an important role in extracellular matrix degradation associated with cancer invasion. An expression of MMP-1 (interstitial collagenase), MMP-2 (72-kDa type IV collagenase) and MMP-3 (stromelysin-1) was investigated in squamous cell carcinoma (SCC) and its precancerous condition, actinic keratosis (AK), using in situ hybridization techniques. MMP-1 mRNA was detected in tumour cells and/or in stromal cells in all cases of SCC, four of six AKs adjacent to SCC and four of 16 AKs. MMP-2 and MMP-3 mRNAs were detected in SCC but not in AK. The expression of MMP-3 correlated to that of MMP-1 (P = 0.03) localized at the tumour mass and stroma of the invasive area, while MMP-2 mRNA was detected widely throughout the stroma independent of MMP-1 expression. Our results indicated that the expression of MMP-1, -2 and -3 showed different localization patterns, suggesting a unique role of each MMP in tumour progression. Moreover, MMP-1 expression could be an early event in the development of SCC, and AK demonstrating MMP-1 mRNA, might be in a more advanced dysplastic state, progressing to SCC. © 1999 Cancer Research Campaign

Background. An ipsilateral neck dissection is mandatory during initial treatment stages Il-IV oral carcinomas. However, no consensus exists whether or not to perform an elective contralateral neck dissection. Methods. Five hundred thirteen consecutive cases of squamous cell carcinoma (269 tongue, 135 floor of the mouth, 44 inferior gingiva, 65 retromolar trigone) were reviewed. Tumor stages were: 69 T1, 227 T2, 217 T3-T4, 263 N0, 250 N1-N3. A total of 563 neck dissections were performed in 448 patients. Univariate and multivariate analysis of risk factors were performed using logistic regression. Results. Two hundred twenty-three patients (49.8%) had positive nodes in the specimen (182 ipsilateral, 36 bilateral, 5 contralateral). Contralateral neck recurrences occurred in 38 cases (33 not submitted to a contralateral neck dissection initially). Multivariate logistic regression analysis demonstrated that clinical stage (p =.0001), tumor crossing midline (p =.0011), and floor of the mouth involvement (p =.0236) were the most important predictors of contralateral metastasis. Conclusion. The contralateral side of the neck is a common and potentially preventable site of recurrence in tumors of the oral cavity. The multivariate model obtained discriminates patients with low and high risk (more than 20%) of contralateral metastasis. The application of this mathematical model can be useful for the indication of contralateral neck dissections, because not all tumors crossing midline are associated to a high risk (stages I and II tumors not involving the floor of the mouth) and not all tumors not crossing midline are at low risk (stages III and IV tumors involving the floor of the mouth).

The synthesis of LiNiO2 in air is studied by means of X-ray diffraction (XRD) characterization using a new fast method based on the splitting of the (108) and (110) peaks and the depth of the minimum between these peaks. From the evolution of these XRD parameters during the heat treatment of the starting mixture of LiOH and NiO the optimum synthesis time is determined, where the separation angle has a maximum, implying a good stoichiometry and low cation disorder; the minimum between the peak is deepest, indicating a better crystallinity. Selected samples of LiNiO2 were cycled as cathodes in laboratory-coin cells between constant charge and discharge end voltages at a constant current. It is found that the capacity decay rate is related to the phase transitions occurring during cycling. This rate is dependent on the minimum lithium content x in LixNi2 − xO2 at the end of charge. As the cycling proceeds xmin increases despite that the end charge voltage is kept constant, whereby the capacity decay rate diminishes.

The amyloid beta/A4 protein (beta/A4) of Alzheimer disease is heterogeneous. A beta 1-40 (Asp1 to Val40) is rather soluble, whereas A beta 1-42 (Asp1 to Ala42) is more insoluble and can be the seed of deposition of A beta 1-40. Although beta/A4 itself could not be expressed transiently in COS cells by cDNA transfection, it was expressed after directly adding a signal sequence to its N-terminal end. The expressed A beta 1-40 was secreted, whereas A beta 1-42 was hardly secreted. A beta 1-40 secretion was not inhibited by metabolic inhibitors such as brefeldin A. The normally produced A beta 1-40 could not be retained intracellularly, whereas the abnormally generated A beta 1-42 might be accumulated intracellularly, resulting in cellular toxicity.

The effect of CsA on hypoxia-reoxygenation injury was studied in perfused rat livers. CsA did not attenuate hypoxic injury, as assessed by the release of lactate dehydrogenase and mitochondrial aspartate aminotransferase. During reoxygenation, the release of lactate dehydrogenase was also not affected by CsA. However, the release of mitochondrial aspartate aminotransferase into the cytosol, which indicates mitochondrial injury, was significantly reduced by CsA. The effect of CsA on mitochondrial function during hypoxia-reoxygenation was also investigated. CsA administration increased both the respiratory control ratio and the adenine nucleotide content after reoxygenation in both isolated mitochondria and perfused livers. In addition, glucose production by perfused livers after reoxygenation was increased by CsA. We conclude that the beneficial effect of CsA on hypoxia-reoxygenation injury may be partly due to protection of the mitochondria against reoxygenation injury.

SUT-8701 is a cholecystokinin octapeptide (CCK8) analog and a more lipophilic peptide than CCK8. We previously demonstrated that intra-ventricularly administered CCK8 protected against the degeneration of the cholinergic neurons in the cortex of the nucleus basalis magnocellularis (nbm)-lesioned rat. We determined whether SUT-8701 and CCK8 have the ability to protect against cholinergic degeneration in the cerebral cortex of nbm-lesioned rats. Systemically administered SUT-8701 (0.1-1 micrograms/day/animal, s.c.) preserved choline acetyltransferase activity and K(+)-evoked acetylcholine release in nbm-lesioned rats. SUT-8701 was more potent than CCK8. However, SUT-8701 was much less potent than CCK8 in satiety action. The affinity of SUT-8701 to the cholecystokinin (CCK) receptors assessed by using [125I]-CCK8 was almost the same as that of CCK8 in the mouse cerebral cortex, but was 107 times less than that of CCK8 in guinea pig pancreas. These results suggest that SUT-8701 may be effective in slowing down the degenerative processes in Alzheimer's disease by preserving the integrity of cholinergic neurons in the nucleus basalis.

Amyloid beta protein (beta/A4) is deposited in senile plaques of patients with Alzheimer's disease. This protein is derived from a larger membrane-associated protein, termed amyloid precursor protein (APP). The constitutive processing of APP occurs at the central portion of beta/A4, resulting in the release of large N-terminal peptides. We have purified these peptides from the culture medium of cDNA-transfected COS-1 cells. Some of the isoforms contain the Kunitz-type protease inhibitor (KPI) domain and strongly inhibit trypsin, chymotrypsin and plasmin, but do not inhibit kallikrein, prolyl endopeptidase or granzyme A. The peptides also do not inhibit cysteine proteases such as cathepsin B or calpain. Soluble APPs lacking the KPI domain fail to inhibit any of these proteases. The results indicate that the KPI domain in soluble APPs has protease inhibitory activity against certain serine proteases.

Recent progress of the externally and internally stabilized RHQT (rapid‐heating, quenching and transformation) processed Nb3Al superconductors are described and compared. The internal stabilization method has been improved by demonstrating that the Ag can be included in the strand in various places, increasing the Ag volume ratio, decreasing an overall residual resistivity of conductor, and enhancing the RRR. An attempt was made to fabricate a coil using such an internally stabilized conductor, and its result has been compared to that of Cu clad conductors.

Background: Fukuyama-type congenital muscular dystrophy (FCMD) is an autosomal recessive disorder characterized by severe dystrophic muscle wasting from birth or early infancy with structural brain abnormalities. The gene for FCMD is located on chromosome 9q31, and encodes a novel protein named fukutin. The function of fukutin is not known yet, but is suggested to be an enzyme that modifies the cell-surface glycoprotein or glycolipids. Objective: To elucidate the roles of fukutin gene mutation in skeletal and cardiac muscles and brain. Methods: Immunohistochemical and immunoblot analyses were performed in skeletal and cardiac muscles and brain tissue samples from patients with FCMD and control subjects. Results: The authors found a selective deficiency of highly glycosylated α-dystroglycan, but not β-dystroglycan, on the surface membrane of skeletal and cardiac muscle fibers in patients with FCMD. Immunoblot analyses also showed no immunoreactive band for α-dystroglycan, but were positive for β-dystroglycan in FCMD in skeletal and cardiac muscles. Conclusion: The current findings suggest a critical role for fukutin gene mutation in the loss or modification of glycosylation of the extracellular peripheral membrane protein, α-dystroglycan, which may cause a crucial disruption of the transmembranous molecular linkage of muscle fibers in patients with FCMD.

T-box genes encode a novel family of sequence-specific activators that appear to play crucial roles in various processes of animal development. Although most of the T-box genes are involved in the mesoderm formation of chordate embryos, mammalian T-Brain is expressed in the developing central nervous system, and defines molecularly distinct domains within the cerebral cortex. Here we report the first invertebrate T-Brain homologue from the hemichordate acorn worm, Ptychodera flava, which we designate Pf-Tbrain. Developmental expression of Pf-Tbrain was examined by whole mount in situ hybridization to various stages of P. flava embryos. A weak, broad in situ hybridization signal of the Pf-Tbrain transcript is first detected during gastrulation in cells around the archenteron, but this signal disappears as gastrulation proceeds. At mid-gastrula an intense signal appears in several apical ectoderm cells of the gastrula. This signal becomes restricted to the apical region, where the eyespots or the light-sensory organ of the tornaria larva form. Expression of Pf-Tbrain in the apical sensory organ of the tornaria and vertebrate T-Brain in the forebrain suggests an evolutionary relationship between the non-chordate deuterostome larval apical sensory organ and the chordate forebrain.

Acorn worms are hemichordate deuterostomes that have remarkable gills thought to be homologous to pharyngeal gills in urochordates and cephalochordates, and pharyngeal pouches in vertebrates. In search of molecular keys to analyzing the origin and evolution of the anterior gut and neck region of the chordate body, the present study isolated cDNA clones for six gill-specific genes, designated PfG1 to PfG6, from Ptychodera flava using differential screening of a cDNA library of RNA from gills. Northern blotting confirmed that these genes were all expressed only in the gills. In situ hybridization showed that the expression of these genes is limited to the endodermally derived columnar epithelium of the pharynx. PfG1 encodes a 42-kDa polypeptide containing sequence similar to D-domains, protein domains characteristic of extracellular proteins. Expression of PfG1 is localized in a delimited pattern along the columnar epithelium of the inner gill apparatus. Expression in the epibranchial ridge appears as two stripes running longitudinally in the epithelium just lateral of the midline. A stripe of expression also appears in a slightly posterior portion on the curve of each band of columnar epithelium on the pharyngeal surface of the secondary gill bars. The five other gill-specific genes, PfG2 to PfG6, encode a family of C-type lectin polypeptides that appear to be secreted proteins. PfG2 to PfG6 are also expressed in the columnar epithelium of the epibranchial ridge as two parallel stripes, but at the lateral margin of the ridge. One of the genes, PfG6, is additionally expressed in the innermost curve of the epithelium on the pharyngeal surface of each secondary gill bar. The localization of expression of PfPax1/9, a gill-specific transcription factor gene, was examined and shown to also be primarily in the endodermal columnar epithelium on the pharyngeal faces of the gill bars. On the secondary gill bars, where PfG1 and PfG6 are also expressed in the columnar epithelium, PfPax1/9 is expressed in the anterior and posterior portions but signal is not evident in the epithelium on the central, innermost curve of the gill bar. The anterior domain of PfPax1/9 expression is more extensive but overlaps the anterior domain of PfG1 expression, whereas its posterior domain of expression is more posterior and complementary to that of PfG6.

An ipsilateral neck dissection is mandatory during initial treatment stages II-IV oral carcinomas. However, no consensus exists whether or not to perform an elective contralateral neck dissection.Five hundred thirteen consecutive cases of squamous cell carcinoma (269 tongue, 135 floor of the mouth, 44 inferior gingiva, 65 retromolar trigone) were reviewed. Tumor stages were: 69 T1, 227 T2, 217 T3-T4, 263 N0, 250 N1-N3. A total of 563 neck dissections were performed in 448 patients. Univariate and multivariate analysis of risk factors were performed using logistic regression.Two hundred twenty-three patients (49.8%) had positive nodes in the specimen (182 ipsilateral, 36 bilateral, 5 contralateral). Contralateral neck recurrences occurred in 38 cases (33 not submitted to a contralateral neck dissection initially). Multivariate logistic regression analysis demonstrated that clinical stage (p = .0001), tumor crossing midline (p = .0011), and floor of the mouth involvement (p = .0236) were the most important predictors of contralateral metastasis.The contralateral side of the neck is a common and potentially preventable site of recurrence in tumors of the oral cavity. The multivariate model obtained discriminates patients with low and high risk (more than 20%) of contralateral metastasis. The application of this mathematical model can be useful for the indication of contralateral neck dissections, because not all tumors crossing midline are associated to a high risk (stages I and II tumors not involving the floor of the mouth) and not all tumors not crossing midline are at low risk (stages III and IV tumors involving the floor of the mouth).