Temporary abolition of pain in man

In eight patients with intense chronic cutaneous pain, sensory nerves or roots. supplying the painful area were stimulated. Square-wave 0.1-millisecond pulses at 100 cycles per second were applied, and the voltage was raised until the patient reported tingling in the area. During this stimulation, pressure on previously sensitive areas failed to evoke pain. Four patients, who had diseases of their peripheral nerves, experienced relief of their pain for more than half an hour after stimulation for 2 minutes.     

Phonon dispersions of fcc delta-plutonium-gallium by inelastic x-ray scattering

We report an experimental determination of the phonon dispersion curves in a face-centered cubic (fcc) delta-plutonium-0.6 weight % gallium alloy. Several unusual features, including a large elastic anisotropy, a small-shear elastic modulus C', a Kohn-like anomaly in the T1[011] branch, and a pronounced softening of the [111] transverse modes, are found. These features can be related to the phase transitions of plutonium and to strong coupling between the lattice structure and the 5f valence instabilities. Our results also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory calculations for delta-plutonium.     

企业要重视专利和专利管理

当前我国企业专利管理存在许多问题,面对参与国际市场竞争的严峻形势,必须要加强企业专利管理工作,并提出了一些专利管理的方法。     

Visibility of single atoms

Theoretical and experimental studies indicate that, with a high-resolution scanning electron microscope, it is now possible to obtain pictures of a single heavy atom resting on a thin carbon substrate.     

Cell-to-cell transfer of bacterial outer membrane lipoproteins

Myxococcus xanthus cells can glide forward by retracting type IV pili. Tgl, an outer membrane lipoprotein, is necessary to assemble pili. Tgl mutants can be transiently "stimulated" if brought into end-to-end contact with tgl+ donor cells. By separating the stimulated recipient cells from donor cells, we found that Tgl protein was transferred from the donors to the rescued recipient cells. Mutants lacking CglB lipoprotein, which is part of a second gliding engine, could also be stimulated, and CglB protein was transferred from donor to recipient cells. The high transfer efficiency of Tgl and CglB proteins suggests that donor and recipient cells briefly fuse their outer membranes.     

Mercury Concentrations in Largemouth BASS (Micropterus Salmoides) from Five South Carolina Reservoirs

Mercury concentrations in largemouth bass (Micropterus salmoides) bass were compared among five reservoirs in South Carolina. Three of these reservoirs (Lake Russell, Lake Thurmond, and Lake Marion) are accessible to the public and two (L-Lake and Par Pond) are located on the U.S. Department of Energy's Savannah River Site (SRS), which is closed to public access. Age-adjusted mercury concentrations were significantly higher in SRS bass compared to the offsite reservoirs. In addition, mercury concentrations were significantly higher in bass from Par Pond compared to L-Lake and in bass from Lakes Russell and Thurmond compared to Lake Marion. No mercury concentrations in excess of the U.S. Food and Drug Administration action level (1.0 mg?kg^?1) were found in any bass from the public-accessible reservoirs. However, the majority of fish from these reservoirs had mercury concentrations that fall into or exceed the U.S. Environmental Protection Agency consumption category of “no more than one per week". In addition, most fish from these reservoirs had mercury levels in excess of those believed to be detrimental to sensitive avian species.     

Occurrence of cataracts in triploid Atlantic salmon (Salmo salar) on four farms in Scotland.

In September 1991 cataracts occurred in two year-classes of triploid Atlantic salmon. The fish showed varying degrees of blindness, were lethargic and became emaciated owing to their inability to feed. The lesions in the lens were mainly in the anterior and posterior cortex and perinuclear areas, the capsule and embryonic nucleus remaining unaffected. Diploid fish of the same year-class did not have cataracts. The origin of the triploid fish, the method of triploidisation, their diet and disease status were investigated, but no predisposing factors could be found to account for the high incidence of cataracts.     

Genetic engineering of mammalian embryos

A gene consisting of the mouse metallothionein I promoter/regulator (MT) fused to the human growth hormone (hGH) structural gene (MThGH) was microinjected into rabbit, sheep and pig eggs. Visualization of nuclear structures was accomplished by interference-contrast (I-C) microscopy for rabbit and sheep eggs and by centrifugation and I-C microscopy for pig eggs. The gene integrated into the chromosomes of each species with an efficiency of 13% in rabbits, 1% in sheep and 10% in pigs. Human GH mRNA was detected in the liver of transgenic rabbits as well as tail and ear samples of pigs. Immunoreactive hGH was present in the serum of a transgenic rabbit and plasma of most transgenic pigs. In several pigs hGH levels increased between birth and 90 d of age. The presence of substantial quantities of hGH in plasma of pigs did not increase postnatal somatic growth rates. Founder animals will be bred and their transgenic and control progeny used to assess the effects of hGH on feed efficiency and carcass composition. These experiments demonstrate the feasibility of introducing foreign genes into the genome of several animal species by microinjection of eggs.