Research output and transnational cooperation in physics subfields: A multidimensional analysis

This paper compares the profiles of research output and transnational cooperation (as revealed through multicountry publications) of thirty six countries in ten subfields of Physics during the period 1981–1985. The data for comparative analysis were taken fromBraun et al. Since raw counts of publications are confounded by the size of the countries and the size of the research fields, this comparison is made, using relative indicators — activity index and collaboration index. The structures of research output and transnational cooperation are analyzed through Correspondence Analysis, which leads to the identification of countries with similar profiles (of research output and transnational cooperation) and the spatial representation of countries and Physics subfields. The configurations of research output and transnational cooperation are compared to assess the concordance between the policies of these countries for research and transnational cooperation in Physics.     

Aesthetic outcome of breast implant removal in 85 consecutive patients

As we began to see increasing numbers of women concerned about their gel-filled breast implants, we became aware that we could not advise them with any degree of confidence what they might expect in terms of aesthetic result after implant removal. We decided to review the records and outcomes over a 2-year period of a number of patients who underwent implant removal. Eighty-five consecutive patients were reviewed, 69 of whom had undergone cosmetic augmentation and 16 of whom had breast reconstruction with silicone gel implant(s). Thirty-nine of the 69 cosmetic augmentation patients had removal of implants alone, and 27 had removal accompanied by mastopexy. Three had reaugmentation with saline-filled implants; one had replacement with saline-filled implants. Fifteen of the 16 reconstruction patients underwent autogenous tissue transfer. Preoperative and postoperative photographs of all patients were mixed randomly and rated by two independent raters in four aesthetic categories on a five-point scoring system. Repeatability was measured several weeks later, when each rater scored randomly selected photographs from this patient pool. The patients also performed their own outcome evaluations by means of questionnaire. We discovered that cosmetic augmentation patients who undergo implant removal only often suffer adverse aesthetic results. The postremoval appearance of many cosmetic augmentation patients actually will be improved over their preoperative appearance when mastopexy is performed in conjunction with implant removal. The study demonstrated that patients with certain body types could expect a particular outcome; i.e., women with asthenic builds and older patients with lax, striated breast skin generally had unsatisfactory aesthetic outcomes with implant removal only. Patients selected for autogenous breast reconstruction had favorable results, with extended latissimus dorsi and TRAM flaps yielding equally good outcomes. The study allows us to offer patients an optimistic view of postoperative results following breast implant removal. We have begun to advise selected patients that implant removal accompanied by mastopexy provides a more pleasing aesthetic outcome than implant removal alone.     

Effect of rare-earth doping on the electrical and photoelectrical properties of furazano [ 3,4-b] piperazine (FP) thin-film devices

Schottky diodes of rare-earth, praseodymium (Pr)-doped and samarium (Sm)-doped furazano [3,4-b] piperazine (FP), sandwiched between Al and indium-tin oxide (ITO) were made by a spin-coating technique. The diodes, in which doped FP behaves as a p-type organic semiconductor, exhibit rectification behaviour. The p-type semiconductivity and rectification properties of the devices improve with rare-earth doping. The electrical effects observed in these devices are explained in terms of the p-type semiconducting behaviour of the doped FP thin films and the formation of a blocking contact (Schottky barrier) with the Al electrode and ohmic contact with the ITO electrode. Various electrical parameters such as carrier mobility, position of Fermi level, free carrier concentration, trap density, trap level and conductivity of doped FP are calculated and discussed. It is found that the position of the Fermi level shifts toward the valence band on rare-earth doping; concentration of free carriers and carrier mobility increase on doping. From the capacitance-voltage (C-V measurements, various electrical parameters such as barrier height, density of ionized acceptor atoms and depletion layer width are calculated and discussed. From the action spectra and absorption spectra it is confirmed that the Al-doped FP interface forms a Schottky barrier and the ITO-doped FP interface shows ohmic contact. The photovoltaic measurement on the two devices reveals that the short circuit current, open circuit voltage, fill factor and power conversion efficiency increase on rare-earth doping.     

Endoneurial localisation of microvascular damage in human diabetic neuropathy

Twenty diabetic patients with neuropathy underwent clinical and neurophysiological evaluation together with a detailed morphometric assessment of capillary pathology in endoneurial and epineurial microvascular beds of the sural nerve. Morphological data were compared with ten non-diabetic control subjects. There were no significant differences in control subjects between basement membrane area, endothelial cell area, endothelial cell profile number or luminal area of endoneurial when compared with epineurial capillaries. In contrast, when compared with epineurial capillaries, endoneurial capillaries from diabetic patients demonstrated a significant increase in basement membrane (p < 0.001) and endothelial cell (p < 0.001) area and a significant reduction in luminal area (p < 0.001). There was no significant difference in endothelial cell profile number between endoneurial and epineurial capillaries amongst diabetic patients. Previous studies have demonstrated a good correlation between the degree of microangiopathy and measures of neuropathic severity. In the present study increased endoneurial capillary basement membrane area was significantly related to reduced peroneal nerve conduction velocity (p < 0.001), myelinated fibre density (p < 0.001) and elevated vibration (p < 0.05) and thermal (p < 0.001) perception. Increased endothelial cell area and reduced luminal size were related to a reduced peroneal nerve conduction (p < 0.05, p < 0.01, respectively), reduced myelinated fibre density (p < 0.05, p < 0.01) and elevated thermal perception (p < 0.05, p < 0.001). Epineurial capillary basement membrane, endothelial cell and luminal area failed to relate to measures of neuropathic severity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Unusual chromosomal organization of telomeric sequences and expeditious karyotypic differentiation in the recently evolved Mus terricolor complex

The Mus terricolor complex displays a stable homozygous arrangement of autosomal heterochromatin variations in the form of accretion of definitive autosomal short arms among three nonoverlapping populations, in concert with an expeditious evolutionary differentiation into three chromosomal species: M. terricolor I, II, and III. In contrast to the highly conservative M. musculus-like chromosomes in the coexisting sibling species, M. booduga, reshuffling and differentiation of centric heterochromatin has occurred in harmony with a revision of centric configurations, resulting in acrocentric and submetacentric autosomes. The chromosomal distribution of the prevalent vertebrate telomeric sequence (TTAGGG)n was examined by fluorescence in situ hybridization to metaphase cells of M. terricolor I, II, and III. An unusual centric organization of internal telomeric sequences was detected in all the submetacentric and acrocentric autosomes. An auxiliary role of these presumably fragile, recombinogenic telomeric sequences in the evolutionary revision of centric configurations in the terricolor complex is hypothesized.     

Kinetic Studies on Cocracking of Petroleum Vacuum Residue with Thermoplastics and Biomass (Petrocrop)

Cracking of petroleum vacuum residue (XVR) and its cocracking with plastics (PP or PS), Calotropis procera (CL) as a binary, ternary, and quaternary mixture of these individual plastics, and CL with XVR was carried out in a Perkin-Elmer thermogravimetric analyzer (TGA) for the purpose of comparing the process of the mixture with those of the individual components. Experiments were conducted at a heating rate of 40 K/min, in the temperature range of 30-900°C. Based on the results obtained, three temperature regimes were selected for studying the nonisothermal kinetics of TGA of individual XVR, plastics, and biomass as well as of the cocracking of these with XVR, i.e., below 400°C, between 400-500°C, and above 500°C. The kinetic studies were performed using the Coats and Redfern kinetic modeling equation. The overall activation energies obtained were 25 kJ/mole for petroleum vacuum residue, 99 kJ/mole for polypropylene, 21 kJ/mole for coal, and 35 kJ/mole for the mixture of all these materials. Thus, it has been found that there exists an overall synergy when three materials were coprocessed together. The overall orders and activation energies change during coprocessing of two or three different macromolecules, including mixed vacuum residue as presently observed. The detailed results that were obtained will be reported.     

用广播与选择型OADM实现低成本透明光传输

互联网业务和数据业务的不断增长，使长途骨干网中的业务传送模式发生了显著变化。目前，互联网业务流比传统的话音业务流的传送距离远得多。研究表明，从2000年到2005年，北美地区的互联网业务流的平均传输距离将从目前的740公里增长到2700公里。业务传送模式的根本性变化，要求网络设计与运营模式也作相应的更新。今后，网络节点必须能提供更多的带宽和更长的电路连接。如果采用不透明的光网络，所有的信号都必须在每个中间节点进行再生，对于60%的传输距离不超过600公里的话音业务而言是不成问题的；但对于60%的传输距离超过3000公里的互…