Magnetoconduction in the Correlated Semiconductor FeSi in Ultrastrong Magnetic Fields up to a Semiconductor-to-Metal Transition.

Magnetoresistance of the correlated narrow-gap semiconductor FeSi was investigated by the radio frequency self-resonant spiral coil technique in magnetic fields up to 500 T, which is supplied by an electromagnetic flux compression megagauss generator. Semiconductor-to-metal transition accomplishes around 270 T observed as a sharp kink in the magnetoresistance, which implies the closing of the hybridization gap by the Zeeman shift of band edges. In the temperature-magnetic field phase diagram, the semiconductor-metal transition field is found to be almost independent of temperature, which is in contrast to a characteristic magnetic field associated with the hopping magnetoconduction in the in-gap localized states, exhibiting a notable temperature dependence.

A series of magnon crystals appearing under ultrahigh magnetic fields in a kagomé antiferromagnet.

Geometrical frustration and a high magnetic field are two key factors for realizing unconventional quantum states in magnetic materials. Specifically, conventional magnetic order can potentially be destroyed by competing interactions and may be replaced by an exotic state that is characterized in terms of quasiparticles called magnons, the density and chemical potential of which are controlled by the magnetic field. Here we show that a synthetic copper mineral, Cd-kapellasite, which comprises a kagomé lattice consisting of corner-sharing triangles of spin-1/2 Cu2+ ions, exhibits an unprecedented series of fractional magnetization plateaus in ultrahigh magnetic fields of up to 160 T. We propose that these quantum states can be interpreted as crystallizations of emergent magnons localized on the hexagon of the kagomé lattice.

Record indoor magnetic field of 1200 T generated by electromagnetic flux-compression.

A peak field of 1200 T was generated by the electromagnetic flux-compression (EMFC) technique with a newly developed megagauss generator system. Magnetic fields closely up to the turn-around peak were recorded by a reflection-type Faraday rotation magnetic-field optical-fiber probe. The performance was analyzed and compared with data obtained by the preceding EMFC experiments to show a significant increase in the liner imploding speed of up to 5 km/s.

Note: An approach to 1000 T using the electro-magnetic flux compression.

The maximum magnetic field obtained by the electro-magnetic flux compression technique was investigated with respect to the initial seed magnetic field. It was found that the reduction in the seed magnetic field from 3.8 T to 3.0 T led to a substantial increase in the final peak magnetic field. The optical Faraday rotation method with a minimal size probe evades disturbances from electromagnetic noise and shockwave effects to detect such final peak fields in a reduced space of an inner wall of the imploding liner. The Faraday rotation signal recorded the maximum magnetic field increased significantly to the highest magnetic field of 985 T approaching 1000 T, ever achieved by the electro-magnetic flux compression technique as an indoor experiment.

Anomalous diamagnetic shifts in InP-GaP lateral quantum-wires.

Linearly polarized photoluminescence (PL) measurements were carried out on InP-GaP lateral nanowires grown using a lateral composition modulation method in pulsed magnetic fields up to ∼ 50 T. In these structures, the energy band alignment becomes type-I and type-II in In-rich wire and Ga-rich barrier regions, respectively. It is revealed that the polarization of the type-I PL is oriented along the [11̄0] crystal direction, whereas that of the type-II PL is along the [110] direction in the absence of magnetic field. These two different PL peaks exhibit anomalous energy shifts with respect to the direction of the magnetic field due to the variation of the confined energy in the exciton center of mass potential.

Note: Experimental evidence of three-dimensional dynamics of an electromagnetically imploded liner.

The time-dependent spatial distribution of magnetic fields generated by the electromagnetic flux compression technique is investigated, with emphasis on the dynamical processes of an imploding liner. The developing magnetic field distribution in space and time is determined by a three-dimensional implosion process of the liner that is settled in a primary coil, using an advanced numerical calculation.

Precise measurement of a magnetic field generated by the electromagnetic flux compression technique.

The precision of the values of a magnetic field generated by electromagnetic flux compression was investigated in ultra-high magnetic fields of up to 700 T. In an attempt to calibrate the magnetic field measured by pickup coils, precise Faraday rotation (FR) measurements were conducted on optical (quartz and crown) glasses. A discernible "turn-around" phenomenon was observed in the FR signal as well as the pickup coils before the end of a liner implosion. We found that the magnetic field measured by pickup coils should be corrected by taking into account the high-frequency response of the signal transmission line. Near the peak magnetic field, however, the pickup coils failed to provide reliable values, leaving the FR measurement as the only method to precisely measure extremely high magnetic fields.

Static friction as a function of waiting time probed by the dynamics of driven vortices in La(2 - x)Sr(x)CuO4 thin films.

We systematically investigated the waiting-time dependence of the maximum static friction force, F(s)(t(w)), using the dynamics of driven vortices in a high-T(c) superconductor as a model system. F(s)(t(w)) was measured in La(2 - x)Sr(x)CuO(4) thin films with different structures, sample sizes and pinning force. We found that F(s)(t(w)) by thermal fluctuation is strongly affected by the pinning strength, the vortex bundle size and the system size. Based on these results, we found crucial conditions to determine the validity of the Amontons-Coulomb's law, and proposed a criterion.

Daily changes of salivary secretory immunoglobulin A and appearance of upper respiratory symptoms during physical training.

AIM: It is well known that highly trained athletes suffer from a high incidence of upper respiratory tract infections (URTI). Secretory immunoglobulin A (SIgA) is a major effector of mucosal surface protection against microorganisms causing URTI. Although several studies have investigated the relationship between falls in SIgA levels and appearance of URTI symptoms, the relationship is not yet clear. METHODS: We prospectively investigated the relationship between daily changes in SIgA and appearance of URTI symptoms in collegiate soccer players during a training period of 2 months. RESULTS: Five of 12 subjects exhibited URTI symptoms during the study period. The SIgA level did not significantly decrease before appearance of URTI symptoms. However, the saliva flow rate and SIgA secretion rate tended to decrease 3 days before the appearance of URTI symptoms compared to that in the non-infection period (31.3+/-19, -42.2+/-20.6%, respectively). CONCLUSIONS: We could not demonstrate a significant relationship between decreased SIgA levels and appearance of URTI symptoms during the training period. However, our findings suggest that monitoring of SIgA secretion rate may be useful for assessment of risk status of athletes for URTI.

An approach for protein to be completely reversible to thermal denaturation even at autoclave temperatures.

Reversibility of protein denaturation is a prerequisite for all applications that depend on reliable enzyme catalysis, particularly, for using steam to sterilize enzyme reactors or enzyme sensor tips, and for developing protein-based devices that perform on-off switching of the protein function such as enzymatic activity, ligand binding and so on. In this study, we have successfully constructed an immobilized protein that retains full enzymatic activity even after thermal treatments as high as 120 degrees C. The key for the complete reversibility was the development of a new reaction that allowed a protein to be covalently attached to a surface through its C-terminus and the protein engineering approach that was used to make the protein compatible with the new attachment chemistry.

The use of the Millard "crane" flap for deep hand burns with exposed tendons and joints.

Deep hand burns with exposed tendons and joints are rare but devastating injuries. They cannot be grafted and require flaps. Abdominal or groin flaps are commonly used, but they are bulky and require separation of the digits. We tried the Millard "crane" flap for these burns and compared our patients' results with those of patients who had received standard abdominal skin flaps. Eleven deep hand burns that had been treated with flaps were evaluated. Six patients had been treated with the crane flap and 5 had been treated with conventional abdominal skin flaps. All crane procedures provided graftable wound beds. The total active ranges of motion of all 11 patients 6 months after the surgical procedures showed no statistical difference. The crane method also provides good cosmetic results. None of the hands treated with crane flaps required procedures to separate the digits or debulk the flaps, but all of the hands treated with conventional abdominal skin flaps required these types of procedures.

Bowel preparation for flexible sigmoidoscopy: which method yields the best results?

BACKGROUND: Bowel preparation is a significant aspect of the flexible sigmoidoscopy procedure. Clear visibility of the bowel mucosa is critical for a thorough examination. The combination of a light breakfast in the morning and the application of 2 phosphate enemas a few hours before the examination is a safe and commonly used method of preparing a patient for a flexible sigmoidoscopy procedure. However, there is a paucity of objective data on the efficacy of this method of bowel preparation. It has been practiced on the basis of intuition and clinical experience. METHODS: In this prospective single-blinded randomized study, 429 consecutive patients were assigned to receive 1 of 4 different bowel preparations before elective 60-cm flexible sigmoidoscopy. After completion of the procedure, the examiner gave a subjective rating of the quality of the preparation. The rating was determined on the basis of the percentage of bowel mucosa that was visible. RESULTS: Statistical analysis of results suggests no significant difference in frequency of favorable ratings between the 4 bowel preparations. CONCLUSIONS: This study substantiates the practice of having a light breakfast and 2 phosphate enemas as a method of bowel preparation for a flexible sigmoidoscopy procedure. Additional preparatory measures such as dietary restrictions and ingestion of phospho-soda oral saline laxative did not significantly enhance the quality of the examination.

The Unna 'sleeve': an effective postoperative dressing for pediatric arm burns.

The goal of this study was to develop a postoperative plan for sheet grafts that would protect the graft, yet would also eliminate the need for daily wound care. Eleven pediatric patients (13 arms burns) who underwent excision and grafting were included in our study. The total area on the arm ranged from 1% to 5% total body surface area. All grafts were sheet grafts held in place with steri-strips or sutures. The grafts were covered with a layer of greasy gauze, followed by an Unna done paste dressing, and then an elastic bandage. The Unna "sleeve" remained in place for an average of 6 days (range, 3 to 10 days). In eight cases, a second Unna sleeve was applied and removed 6 to 7 days later. In all 13 cases, additional wound care for grafts was unnecessary, and patients did not require extended inpatient hospitalization. Graft take was 100% in all cases, and no reconstruction was required.

Supramolecular structure of the Salmonella typhimurium type III protein secretion system.

The type III secretion system of Salmonella typhimurium directs the translocation of proteins into host cells. Evolutionarily related to the flagellar assembly machinery, this system is also present in other pathogenic bacteria, but its organization is unknown. Electron microscopy revealed supramolecular structures spanning the inner and outer membranes of flagellated and nonflagellated strains; such structures were not detected in strains carrying null mutations in components of the type III apparatus. Isolated structures were found to contain at least three proteins of this secretion system. Thus, the type III apparatus of S. typhimurium, and presumably other bacteria, exists as a supramolecular structure in the bacterial envelope.

Silipos neck wraps.

Burns of the neck are a problem. Grafted anterior necks can result in disfiguring hypertrophic scar contractures and wrinkling of the graft. The development of contractures can be prevented by effective splinting as soon as possible after the burn and by following a continuous wearing schedule until scar maturation is complete. Traditional neck conformers do not allow free neck rotation and can lead to stiffness as a result of decreased mobility. We used Silipos neck wraps for 10 patients who had good range of motion in the neck and who required pressure only for flattening of grafts and wrinkle prevention. The neck wrap is user-friendly, low in cost, and easy to fabricate and custom-fit for individual patients.

Improved burn scar assessment with use of a new scar-rating scale.

The subjective assessment of scar appearance is a widely used method in the evaluation of burn outcomes and the efficacy of treatment methods. The purpose of this study is to design a numeric scar-rating scale with better interrater reliability than has previously been reported. The rating scale assesses scar surface, thickness, border height, and color differences between a scar and the adjacent normal skin. Eight raters were trained with use of a standardized set of photographs that provide examples of the scores to be assigned to each level of severity of each scar characteristic. The raters then rated 10 photographs of different scars, referring to the teaching set of pictures for comparison. The intraclass correlation (interrater reliability) was 0.94, 0.95, 0.90, and 0.85 for scar surface, border height, thickness, and color, respectively. This rating system has proved to be a useful tool for the evaluation of scar surface, thickness, border height, and color.

Purification and characterization of the flagellar hook-basal body complex of Bacillus subtilis.

The flagellar hook-basal body (HBB) complex of the Gram-positive bacterium Bacillus subtilis was purified and analysed by electron microscopy, gel electrophoresis, and amino acid sequencing of the major component proteins. The purified HBB complex consisted of the inner (M and S) rings, a rod and a hook. There were no outer (P and L) rings that are found in Gram-negative bacteria. The hook was 15 nm in thickness and 70 nm in length, which is thinner and longer than the hook of Salmonella typhimurium. The hook protein had an apparent molecular mass of 29 kDa, and its N-terminal sequence was identical to that of B. subtilis FIgG, which was previously reported as a rod protein. The sequence of the reported FIgG protein of B. subtilis is more closely related to that of FIgE (the hook protein) rather than FIgG (the rod protein) of S. typhimurium, in spite of the difference of the apparent molecular masses between the two hook proteins (29 kDa versus 42 kDa). The hook-basal body contained six major proteins (with apparent molecular masses of 82, 59, 35, 32, 29 and 20 kDa) and two minor proteins (23 kDa and 13 kDa), which consistently appeared from preparation to preparation. The N-terminus of each of these proteins was sequenced. Comparison with protein databases revealed the following polypeptide-gene correspondences: 82 kDa, fIiF; 59 kDa, fIgK; 35 kDa, orfF; 32 kDa, yqhF; 23 kDa, orf3 of the fIaA locus; 20 kDa, fIgB and fIgC; 13 kDa, not determined. The band at 20 kDa was a mixture of FIgB and FIgC, as revealed by two-dimensional gel analysis. Characteristic features of B. subtilis HBB are discussed in comparison with those of S. typhimiurium.

Trypsin and elastase inhibitors from bitter gourd (Momordica charantia LINN.) seeds: purification, amino acid sequences, and inhibitory activities of four new inhibitors.

Serine proteinase inhibitors of the squash family were isolated from bitter gourd (Momordica charantia LINN.) seeds by the conventional purification method. Heat treatment of the extract of the seeds allowed removal of large amounts of protein without loss of trypsin and elastase inhibitory activities. From the supernatants thus obtained, the inhibitors were isolated to homogeneity by ion-exchange chromatography, gel filtration, and reversed phase chromatography. One trypsin inhibitor (Momordica charantia trypsin inhibitor-III; MCTI-III) and three elastase inhibitors (Momordica charantia elastase inhibitor-II, -III, and -IV; MCEI-II, -III, and -IV) were newly isolated in addition to trypsin inhibitors MCTI-I and -II and elastase inhibitor MCEI-I previously reported [Hara, S. et. al. (1989). J. Biochem. 105, 88-92]. The primary structures of the four new inhibitors were determined as follows. [sequence: see text] The dissociation constants, Ki, of MCTI-III complex with bovine beta-trypsin, and of MCEI-II, -III, -IV with porcine elastase were determined to be 1.9 x 10(-7) M, 9.4 x 10(-9) M, 4.0 x 10(-9) M, and 4.7 x 10(-9) M, respectively. Although MCTI-III differed from MCTI-I in only two amino acids, having Gly(3) and Gln(13) in place of Arg(3) and Arg(13), the Ki value of MCTI-III was 20-fold larger than that of MCTI-I. Addition of an amino terminal Glu residue, a dipeptide (Glu-Glu-), and a tripeptide (Glu-Glu-Glu-) to MCEI-I strengthened its elastase inhibitory activity by 200-fold.