Thermodynamic and spectroscopic measurements of the electron-hole drop binding energy in Ge: An old problem revisited

One can expect to get the electron-hole (EHD) binding energy φ either from spectroscopic or from threshold measurements. While the value obtained by the former is in excellent agreement with theory, the results given by the latter did not seem to lead to φ in a simple way. We present here new optical threshold studies in which we think that the right conditions to obtain a direct thermodynamic measurement of φ have been mastered. Besides, our results present novel features like a sharp jump of the EHD luminescence at threshold above 2.4 K and observation of hysteresis in the whole temperature range of our work.     

Shock wave pulse pressure after penetration of kidney tissue

Lithotripter generated compressional peak pressure (p⁺) was measured after penetrating tissue samples 0.5, 1, 2.5, and 4 cm thick. The samples were taken from fresh pig kidneys and insonated by shock wave pulses with positive peak pressures varying from 14 to 72 MPa. The measurement results allow one to draw some qualitative conclusions concerning the attenuation process in the lithotripter beam and show that in practice the compressional peak pressure values generated in the lithotripter may decrease almost by a factor of two before reaching the kidney stone. On the contrary, theoretical estimates indicate that negative pressures are practically not influenced by attenuation due to their different spectral composition     

Effect of coordination training on proprioception of the functionally unstable ankle

Exercises to improve joint proprioception and coordination of the functionally unstable ankle are advocated throughout the literature, yet there is little evidence that these exercise have any effect on proprioception and balance. The purpose of this study was to determine the effects of a 6-week coordination and balance training program on proprioception of subjects with functional ankle instability. Forty-five subjects (age = 22.53 +/- 3.95 years, height = 172.04 +/- 10.0 cm, weight = 71.72 +/- 15.7 kg) were randomly placed into a control (Group 1), sham (Group 2), or experimental (Group 3) group. The experimental group trained 3 days per week, 10 minutes each day, performing various balance and proprioception exercises. Postural sway and active and passive joint position sense were assessed. Analysis of variance for postural sway modified equilibrium score for anterior and posterior sway, as well as medial and lateral sway revealed significant four-way interactions. Tukey post hoc analyses revealed that Group 3 performed significantly better (p < .05) than Group 1 and Group 2 on the posttests. There were no significant differences for joint position sense or postural sway index. Results suggest that balance and coordination training can improve some measures of postural sway. It is still unclear if joint position sense can be improved in the functionally unstable ankle.     

Mössbauer effect on the spinel oxide FeCoVO4

The valence states in the spinel FeCoVO₄ are studied. After recalling the crystalline structure and the magnetic properties, the different possibilities for valence states of iron and vanadium are discussed. Mossbauer measurements at 342 K give for iron an isomer shift relative to metallic iron I_Fe = (0.34 ± 0.02)mm/sec and a quadrupole splitting $\text{1}\text{4}\text{e}{}^2\text{qQ}\text{= (0.17 ± 0.02)}\text{mm}\text{/}\text{sec}$. Mössbauer spectra at low temperatures are investigated. The formula (Co^II) {Fe^IIIV^III}O₄ is the most probable.     

Germin isoforms are discrete temporal markers of wheat development. Pseudogermin is a uniquely thermostable water-soluble oligomeric protein in ungerminated embryos and like germin in germinated embryos, it is incorporated into cell walls

Nascent synthesis and accumulation of germin and its mRNA mark the onset of renewed growth when wheat embryos are germinated in water. Germin is a water-soluble, pepsin-resistant protein that is not found in immature embryos, or in mature embryos before their germination. An antiserum was raised by injecting rabbits with germin that was freed of other proteins by pepsinization and gel filtration. The antiserum has been used to detect, in extracts of mature embryos from dry, ungerminated wheat grains, a protein that is antigenically related to germin. The antigenically related protein has been named pseudogermin. Pseudogermin accumulates, maximally, between 20-25-days postanthesis, then declines appreciably in amount by 30-days postanthesis, in soluble extracts of immature embryos from several wheat varieties. The antiserum was also used to identify germin and pseudogermin among the proteins extracted from cell walls and to bind immunogold to cell walls preparatory to visualizing freeze-cleaved embryos by scanning electron microscopy. Wall-associated germin accounts for about 40% of the total germin in germinating wheat embryos. Appearance of germin in the apoplast is the most conspicuous germination-related change in the distribution of cell-wall proteins. It seems that germin may act at the level of the apoplast and that pseudogermin may subsume the role of germin at low water potentials during embryogenesis. The N-terminal eicosapeptide sequences in germin and pseudogermin are very similar but SDS/PAGE analysis detects discrete differences between the mobilities of their constituent monomers as well as gross differences between the stabilities of the parent oligomers. Like germin, pseudogermin is a water-soluble, pepsin-resistant protein, but pseudogermin has unprecedented disulphide-independent thermostability properties that have never been previously reported for a water-soluble oligomeric protein. Polysaccharides that co-purify with otherwise pure specimens of germin (and pseudogermin) have been isolated for analysis and shown to be highly substituted glucuronogalactoarabinoxylans. The possible biological significance of selective and tenacious association between germin and glucuronogalactoarabinoxylans is discussed in relation to cell expansion during embryogenic and germinative development of wheat, as are some peculiarities of amino-acid sequence that suggest a possible relation between germin and a proton-specific ion pump: gastric ATPase.     

Current results of endoscopic sphincterotomy for lithiasis of the common bile duct

Between January 1989 and June 1990, endoscopic sphincterotomy was performed in 308 consecutive patients with common bile duct stones (mean age: 74 years). Complete clearance of common bile duct was achieved at the first attempt in 65% of cases. This rate was significantly related to the size and the number of biliary stones. The success rate reached 97 percent after repeated endoscopic sessions (127 patients), mechanical lithotripsy (20 patients), extracorporeal or intracorporeal lithotripsy (18 and 11 patients, respectively). During the month following the endoscopic sphincterotomy, 39 patients (13%) developed one or more complications and 11 patients (3.7%) died. The complication rate was related to the time elapsed between biliary opacification and endoscopic sphincterotomy (P = 0.04) and between endoscopic sphincterotomy and total common bile duct clearance (P = 0.0007). No patient younger than 75 years died, but death occurred in 4.5% of the patients older than 75 years. Thirty patients (10%) developed endoscopic sphincterotomy-related complications. Cholangitis and bleeding were the most frequent complications (4 and 2%, respectively). Cholangitis occurred more frequently among the patients older than 75 (P < 0.05) or when transhepatic guided endoscopic sphincterotomy or intracorporeal lithotripsy was used (P < 0.005). Cholangitis led to death in 2 patients, 86 and 87 years old (0.7%). Endoscopic sphincterotomy related complications developed within 48 hours in all but 4 patients (2 patients with pancreatitis and 2 patients with cholecystitis).     

AREP在中国

2005年．AREP在华的首批工程在北京（首都博物馆、西直门交通枢纽）与天津（泰达金融中心、泰丰住宅区）拉开了序幕。     

A design for an immersable pressure-capacitance gauge

An immersable pressure-capacitance gauge has been designed which has a linearity over a pressure range, is non-magnetic and has twice the sensitivity of a single diaphragm     

The mechanical behaviour of porous austenitic stainless steel fibre structures

The mechanical properties of metal fibre porous structures were studied in the light of their potential application as surface coatings of implants. Stainless steel AISI 316 L fibres with diameters of 50 and 100μm were compacted and sintered. The variation of the modulus of elasticity with density, as obtained in tension, corresponds closely with theoretical models. The ultimate failure of the tensile specimens proceeds through the fibres, and not through the sinter bonds, except at lower densities. Differences in yield strength between 50 and 100 μm fibre tensile specimens are explained on the basis of the onset of plastic deformation of the individual fibres. Upon compression the modulus of elasticity is nearly 10 times smaller than in tension. This result is due to the different deformation patterns of the fibres in compression and tension.