A reorientation of the PO3-groups and radiation damage effect in ferroelectric phase transition studied by CW-EPR of PO32- radical in glycine·H3PO3 single crystal

EPR of γ-ray generated PO₃^2- radicals indicates that the four radical centers are equivalent in the paraelectric phase and become inequivalent in the ferroelectric phase due to a ±3° rotation. The phase transition temperature is shifted by irradiation from T_c = 224 K to T_c = 180 K. The molecular mechanism of the order-disorder phase transition is discussed     

Intermediates of prothrombin activation induce intracellular calcium mobilization in rat aortic smooth muscle cells

OBJECTIVES: To determine the diagnostic utility and net cost of magnetic resonance imaging (MRI) in the management of clinically and sonographically inconclusive scrotal lesions. METHODS: A multicenter retrospective review identified 34 patients diagnosed with scrotal MRI following inconclusive clinical and ultrasound (US) evaluation. Final diagnoses were based on surgery (n = 18) or clinical and US follow-up (n = 16). Final diagnoses of 29 testicular lesions were as follows: orchitis (n = 11), infarct (n = 6), neoplasm (n = 6), rupture (n = 3), torsion (n = 2), and radiation fibrosis (n = 1). Final diagnoses of five extratesticular lesions were as follows: epididymitis (n = 2), epididymal abscess (n = 2), and neoplasm (n = 1). Management plans prior to and following MRI findings were formulated by a general urologist and a urologic oncologist. The costs of the pre-MRI and post-MRI management plans were estimated using the Medicare reimbursement schedule. RESULTS: The leading US diagnosis was correct for 10 of 34 patients (29%) and the leading MRI diagnosis was correct for 31 of 34 patients (91%). MRI improved the management plan of the general urologist and urologic oncologist in 19 patients (56%) and 17 patients (50%), respectively. MRI worsened the management plan of both clinicians in 1 patient. Management was unchanged in all other patients. The overall net cost savings were $543 to $730 per patient for the urologic oncologist and the general urologist, respectively, and $3833 per patient originally scheduled for surgery. CONCLUSIONS: Use of MRI after inconclusive clinical and US evaluation of scrotal lesions may improve management, decrease the number of surgical procedures, and result in net cost savings.     

Methods of stunning freshwater fish: impact on meat quality and aspects of animal welfare

 Taking into account aspects of meat quality and animal welfare, three methods of stunning fish were compared: a manual technique (blow on the head, stab in the neck), one using electricity and one using CO₂. The following results were obtained using eel (n=72), carp (n=120) and trout (n=54). From the viewpoint of animal welfare, the effects on the fish were judged. Excitation and mucus secretion as well as the time taken for the fish to be anaesthetized were recorded. With manual and electrical stunning, all fish were anaesthetized almost immediately, while using CO₂ it took 3.2 min (trout), 9.2 min (carp) and 109.7 min (eel) on average. After slaughter and after 3 and 8 days of storage on ice, the fish meat quality parameters, i.e. pH value, water-holding capacity and rigor mortis, were measured. CO₂ stunning gave rise to the lowest pH values and water-holding capacities. Rigor mortis in carp and eel advanced the most. Testing of raw and prepared fish was performed by a panel assessing organoleptic properties. In many cases, fish anaesthetized manually were ranked to be better than those in the other groups. Received: 4 June 1996 / Revised version: 5 July 1996     

Synthesis and biological activity of bile acid-derived HMG-CoA reductase inhibitors. The role of 21-methyl in recognition of HMG-CoA reductase and the ileal bile acid transport system

To increase hepatoselectivity of HMG-CoA reductase inhibitors by using the specific bile acid transport systems, deoxycholic acid-derived inhibitors 9 and 11 have been synthesized, on the basis of the concept of combining in one molecule structural requirements for specific inhibition of the HMG-CoA reductase and specific recognition by the ileal bile acid transport system. The 1-methyl-3-carboxylpropyl subunit of deoxycholic acid was replaced by the 3,5-dihydroxyheptanoic acid lactone of lovastatin, and position 12-OH was esterified with 2-methylbutyric acid. Compounds 9 and 11 were evaluated for their inhibitory activity on rat liver HMG-CoA reductase, cholesterol biosynthesis in HEP G2 cells, and [3H]taurocholate uptake in rabbit brush border membrane vesicles and compared with methyl derivatives 8 and 10. The steroidal 21-CH3 group affects both activity on HMG-CoA reductase and recognition by the ileal bile acid transport system.     

Ethics committees: time to experiment with standards

Ethics committees now exist in most hospitals. Their recent establishment in many institutions was a response to a 1991 mandate by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). Proposed or new legislation in a few states is elevating the status of these committees, either requiring their use in certain cases, allowing them to substitute for judicial review, or granting immunity to those who follow their advice. Despite these recent JCAHO and legislative developments, it is widely recognized that there is a significant lack of data on the effectiveness of these committees and that committee members often lack the requisite education and skills for effective participation in case consultation. We argue that before granting ethics committees additional authority, there is a need for more research on their performance and a period of experimentation with quality standards governing their membership and operations.     

Product Design – The Interaction between Chemistry,Technology and Marketing to Meet Customer Needs

During the 1990s the job profile of the process engineer in the chemical industry went through some lasting changes. Interdisciplinary project cooperation became established, aiming at competitive and thus rapid innovative leadership. The development of new or improved products must focus on customer needs. Besides production performance the customer mainly needs good handling properties and aesthetics. Product design includes both these considerations. We describe the career of a product, beginning with the initial idea and ending with the product being launched onto the market. A methodology for establishing and evaluating customers needs plays a key role in this process. Process engineering enables the technical realization while considering economic as well as time restrictions. This requires some creativity – and often the development of new technologies. Moreover, the successful completion of a project requires the staff involved to appreciate and accept their colleagues who come from the fields of either chemistry or business management (marketing and market research.)     

Locally ion-implanted JFET in an InGaAs/InP p-i-n photodiode layerstructure for a monolithically planar integrated receiver OEIC

A novel planar concept for the monolithic integration of a p-i-n photodiode (PD) and a junction field-effect transistor (JFET) is described. In an otherwise optimized InGaAs/InP PD layer sequence, grown by metalorganic vapor-phase epitaxy (MOVPE), a local Si- and Be-ion implantation has been performed to realize a thin n⁺-doped channel layer and a buried p-layer for the JFET. JFETs (1.6×290 μm) have a maximum transconductance of 100 mS/mm and a cutoff frequency of 7 GHz. PDs with 64-μm diameter show a dark current of 1 nA at -10 V, a responsivity of 1.1 A/W, and a 3-dB bandwidth of 7.6 GHz. The PD-JFET combination exhibits a clear open eye pattern at 200 Mb/s. A receiver sensitivity of -35 dBm for a bit error rate of 10^-9 is estimated     

Advances in the extractive metallurgy of selected rare and precious metals

The broad field of extractive metallurgy, often perceived as an unimportant point of light in the universe of technology, has undergone significant, fundamental changes in the past 30 years. Improved extraction technologies now permit greater metal recovery, reduce the time that metal values are chemically locked up and diminish the economic impact of environmental regulations. Much of this accomplishment is due to the application of solvent extraction. As evidenced by improvements in the extraction of rare and precious metals, research in extractive metallurgy technology not only exists, but has achieved palpable results.     

Toward a Pan-European virtual university in electrical andinformation engineering

This paper presents the first steps taken by several European universities to study various features of the implementation of a virtual university in electrical and information engineering. The usefulness of static Web material's replacing printed text was studied. Simulators of complex data processing and power generating systems were created. Experiences with a remote-controlled process facility were collected. Manufacturing of integrated circuits was visualized. Web-based self-evaluation and feedback systems were implemented for student response assessment. Advanced reactions are basically positive. This work is a contribution to the four-year SOCRATES Thematic Network program of the European Union, lasting from September 1996 until October 2000