bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐dimensional Diamagnetic‐metal Nitronyl Nitroxide Radical Complexes with Dicyanoargentate(I) Bridges: M(NIT4Py)2[Ag(CN)2]2 (M= Zn, Cd)
Authors: Wang Shu‐Ping , Li Dong‐Jiao , Song You , Gao Dong‐Zhao , Chen Jing , Liu Zhan‐Quan , Liao Dai‐Zheng , Jiang Zong‐Hui , Yan Shi‐Ping
Published: May 2005

Two diamagnetic‐metal nitronyl nitroxide radical complexes with dicyanoargentate(I) bridges M(NIT4Py)2[Ag(CN)2]2 (M= Zn, Cd) were synthesized. X‐ray crystallography reveals that the two compounds are isomorphous, which crystallize in the triclinic ${\rm P}{\bar 3}$ space group. Their structures consist of infinite chains of M(NIT4Py)2 units linked by [Ag(CN)2]− μ2‐bridging ligands. The magnetic measurements showed that the χMT values are nearly constants at higher temperature for both complexes. The sharp decreasing of χMT values at lower temperature are related to intermolecular antiferromagnetic interactions, which result from the shortest interchain contacts of nitroxide groups in the crystals.
Crystal Structure and Ionic Conductivity of Cesium Trifluoromethyl Sulfonate, CsSO3CF3
Authors: Hildebrandt Lars , Dinnebier Robert , Jansen Martin
Published: May 2005

The crystal structures of the room and the high temperature modifications of cesium trifluoromethyl sulfonate were solved from high resolution X‐ray powder diffraction data. At room temperature, α‐CsSO3CF3 crystallizes in the monoclinic space group P21 with lattice parameters a = 9.7406(2) Å, b = 6.1640(1) Å, c = 5.4798(1) Å, and β = 104.998(1)°; Z = 2. At temperatures above T = 380 K, a second order phase transformation towards a disordered C‐centered orthorhombic phase in space group Cmcm occurs with lattice parameters at T = 492 K of a = 5.5074(3) Å, b = 19.4346(14) Å, and c = 6.2978(4) Å; Z = 4. Within the crystal structures, the triflate anions are arranged in double layers with the apolar CF3‐groups pointing towards each other. The cesium ions are located between the SO3‐groups. CsSO3CF3 shows a specific ion conductivity ranging from σ = 1.06·10−8 Scm−1 at T = 393 K to σ = 5.18·10−4 Scm−1 at T = 519 K.
Studies with bombesin in man
Authors: Basso Nicola , Lezoche Emanuele , Speranza Vincenzo
Published: May 2005

The bombesin (BBS) infusion test was performed in 232 subjects with a variety of conditions, including 35 normal individuals, 41 duodenal ulcer patients, 13 gastric ulcer patients, and 14 patients with Zollinger‐Ellison syndrome. Side effects occurred in 80% of patients, but in only 6% was the test discontinued due to discomfort. All side effects promptly subsided when BBS infusion was interrupted. The dose of BBS eliciting the maximal gastrin response was 15 ng/kg per minute. In man, BBS showed a powerful stimulatory action on antral and gastrinoma G cells. No effect on duodenal G cells was apparent. Plasma levels of the different molecular forms of gastrin were all augmented by BBS infusion. BBS potentiated the gastrin response to a meal and elicited a prolonged and sustained gastrin response in patients with Menetrier's disease. Cells with BBS‐like immunoreactivity were demonstrated in the gastrointestinal tract of man. These data suggest that BBS may play a physiologic role in man.

The clinical value of the BBS test was mainly assessed in the study of patients with postgastrectomy recurrent ulcer. In these patients, the BBS test clearly segregated patients with hypersecretion of gastrin from patients without such hypersecretion, and helped to elucidate the pathophysiologic features causing hypergastrinemia.

In perspective, BBS should be viewed as an endocrine polyreleaser (gastrin, CCK, PP, glucagon) and as a member of the family of immunoreactive brain‐gut peptides. The role of BBS in the “brain‐gut axis” remains to be determined.
Endocrinology of duodenal ulcer
Authors: Creutzfeldt W. , Arnold R.
Published: May 2005

Several gastrointestinal peptides with proven or suggested endocrine or paracrine functions influence gastric acid secretion, gastrointestinal motility, and mucosal blood flow. Increased or decreased release of such factors could participate in the pathogenesis of duodenal ulcer disease by inducing increased gastric acid concentration in the duodenal bulb. To date, increased stimulation of parietal cells by gastrin has been demonstrated only in patients with gastrinoma, G‐cell hyperplasia, gastric outlet obstruction, hyperparathyroidism, excluded antrum, and short bowel syndrome, but not in the usual duodenal ulcer disease. Also, a defective inhibition of parietal cell function by endocrine or paracrine factors, such as gastric inhibitory polypeptide, secretin, somatostatin and vasoactive intestinal polypeptide, seems not to exist in patients with duodenal ulcer disease. However, as long as the physiology of gastrointestinal peptides in gastric secretion and motility is not understood, a possible role of these factors in the pathogenesis of simple duodenal ulcer disease cannot be excluded.
Effect of duodenal osmolality on gastrin and secretin release and on gastric and pancreatic secretion
Authors: Teichmann Reinhard K. , Swierczek Janusz S. , Rayford Phillip L. , Thompson James C.
Published: May 2005

We have measured the osmolality of duodenal contents in 9 dogs after a hypertonic meal, given either by mouth or directly into the stomach or perfused into the duodenum. A test meal of 2,475 mosm/kg, given by mouth, raised the intraduodenal osmolality to 700–1,500 mosm/kg over a 1‐hour period. Hypertonic glucose solutions (2,000 and 3,400 mosm/kg), given into the stomach, were found to be diluted to about 700 and 1,100 mosm/kg, respectively, at the level of the mid‐duodenum 30 minutes later. Hypertonic saline solutions (1,800 and 2,700 mosm/kg), perfused into the duodenum, created a stable intraluminal osmolality of 800 and 1,200 mosm/kg, respectively, (about 45% that of the perfusate) after 30 minutes.

In 6 Heidenhain pouch dogs, gastric secretion and gastrin release stimulated by food were significantly diminished by administration of hypertonic sodium chloride solution (1,800 mosm/kg) into the duodenum. This hyperosmolality caused greater suppression of acid secretion (52%) than of gastrin release (28%). Stimulation of pancreatic water and bicarbonate secretion and of release of radioimmunoassayable secretin by intraduodenal HCl (pH 1.3) were significantly suppressed when the osmolality of the HCl solution was raised to 2,700 mosm/kg. Pancreatic protein secretion remained unchanged with hypertonic solutions. We have confirmed that stimulation of intraduodenal osmoreceptors inhibits gastric acid secretion in dogs, and we suggest that this is due, at least in part, to a suppression of gastrin release. We further suggest that duodenal osmolar inhibition of pancreatic secretion involves suppression of secretin but does not appear to involve cholecystokinin.
Toward the understanding of complex population dynamics: planktonic community as a model system
Authors: Yoshida Takehito
Published: May 2005

Ecologists have long been interested in understanding population dynamics in nature. Although theoretical ecologists have shown that mathematical models can represent various dynamic behaviors, and empirical ecologists have confirmed that some types of dynamics actually exist in nature, we do not yet completely understand how population dynamics are driven. The list of possible mechanisms driving population dynamics is still growing. Here I review studies of population dynamics carried out both in the field and in the laboratory by my colleagues and myself. I first describe some population dynamics of planktonic organisms living in freshwater lakes, then introduce some mechanisms driving population dynamics, for which theoretical and empirical evidence has only recently begun to accumulate. I also discuss how and why laboratory microcosms are a useful tool in the study of population dynamics. Future challenges to the advance of our understandings of complex population dynamics in nature lie where three different approaches intersect: time‐series data description, mathematical modeling, and laboratory and field experiments.
C‐type natriuretic peptide plasma levels increase in patients with chronic heart failure as a function of clinical severity
Authors: Del Ry Silvia , Passino Claudio , Maltinti Maristella , Emdin Michele , Giannessi Daniela
Published: May 2005

Backgound:

C‐type natriuretic peptide (CNP), secreted by the endothelium and the heart, is structurally related to atrial and brain natriuretic peptides, but its clinical significance in chronic heart failure (CHF) is controversial.

Aim:

To investigate the role of CNP in CHF, plasma CNP levels were determined in a prospective series of 133 patients with CHF (age 64±1 years, left ventricular ejection fraction (EF), 31.5±0.7%, mean±S.E.M.) and in 21 age‐matched healthy subjects.

Methods and results:

CNP was measured by a radioimmunoassay (sensitivity: 0.41±0.009 pg/tube) after a preliminary solid‐phase extraction. Plasma level of CNP in healthy subjects was 2.7±0.2 pg/ml and significantly increased in CHF, as a function of clinical severity: 4.9±0.7 pg/ml in NYHA class I; 7.0±0.4 pg/ml in class II (p<0.001 vs. controls); 9.6±0.7 pg/ml in class III (p<0.001 vs. controls and class I and II), and 11.8±2.0 pg/ml in class IV (p<0.001 vs. controls, class I and II; Fisher's test after ANOVA). A significant relation was also found between CNP plasma levels and EF (R=0.40, p<0.001).

Conclusion:

Plasma CNP elevation is related to clinical and functional disease severity. These findings suggest a pathophysiological role for this peptide that, for its vasorelaxing activity, could influence the endothelial vasomotor response in CHF.
Effects of Atorvastatin on Th polarization in patients with acute myocardial infarction
Authors: Cheng Xiang , Liao Yu‐Hua , Zhang Jinying , Li Bin , Ge Hongxia , Yuan Jing , Wang Min , Lu Baojun , Liu Ying , Cheng Yan
Published: May 2005

Background:

The development of heart failure after acute myocardial infarction (AMI) has been shown to be associated with inflammation, which is positively and negatively regulated by T helper (Th) 1 and Th2 lymphocytes, respectively. Several studies have indicated that statins can improve heart function after AMI.

Aims:

To study the effects of atorvastatin on Th polarization in patients with AMI.

Methods:

Peripheral blood mononuclear cells were collected from 20 patients with AMI treated with oral atorvastatin (10 mg/d, group AMI‐A) and 18 patients with AMI (group AMI‐C) who did not receive treatment with statins. Cytokine‐producing Th lymphocytes were quantified by 3‐color flow cytometry. After in vitro culturing in the presence or absence of atorvastatin (0, 0.3, 1 and 3 μmol/L) for 6 days, cytokine‐producing Th lymphocytes were quantified again in AMI‐C group.

Results:

The ratio of IFN‐γ‐producing T cells was significantly higher in AMI‐C group (17.8%±6.4%) than in the AMI patients treated with oral atorvastatin (AMI‐A, 13.1%±4.6%). In vitro culturing with atorvastatin significantly reduced Th1 development in the AMI‐C group. There was no significant difference on the frequencies of interleukin (IL)‐4‐producing T cells between each group.

Conclusions:

Atorvastatin can reduce Th1 development but has no effect on Th2 cell‐functions in AMI patients. Our findings suggest that atorvastatin can regulate the polarization of Th1/Th2, this may be one of the mechanisms through which atorvastatin improves heart function after AMI.
“Pure” diastolic dysfunction is associated with long‐axis systolic dysfunction. Implications for the diagnosis and classification of heart failure
Authors: Vinereanu Dragos , Nicolaides Eleftherios , Tweddel Ann C. , Fraser Alan G.
Published: May 2005

Aims

To investigate regional systolic function of the left ventricle, to test the hypothesis that “pure” diastolic dysfunction (impaired global diastolic filling, with a preserved ejection fraction ≥50%) is associated with longitudinal systolic dysfunction.

Methods and results

One hundred thirty subjects (31 patients with asymptomatic diastolic dysfunction, 30 with diastolic heart failure, 30 with systolic heart failure; and 39 age‐matched normal volunteers) were studied by conventional and tissue Doppler echocardiography. Global diastolic function was assessed using the flow propagation velocity, and by estimating left ventricular filling pressure from the ratio of transmitral E and mitral annular ETDE velocities (E/ETDE); and global systolic function by measurement of ejection fraction. Radial and longitudinal functions were assessed separately from posterior wall and mitral annular velocities. Global and radial systolic function were similar in patients with “pure” diastolic dysfunction and normal subjects, but patients with either asymptomatic diastolic dysfunction or diastolic heart failure had impaired longitudinal systolic function (mean velocities: 8.0±1.2 and 7.7±1.5 cm/s, respectively, versus 10.1±1.5 cm/s in controls; p<0.001). In subjects with normal ejection fraction, global diastolic function correlated with longitudinal systolic function (r=0.56 for flow propagation velocity, and r=−0.53 for E/ETDE ratio, both p<0.001), but not with global systolic function.

Conclusion

Worsening global diastolic dysfunction of the left ventricle is associated with a progressive decline in longitudinal systolic function. Diastolic heart failure as conventionally diagnosed is associated with regional, subendocardial systolic dysfunction that can be revealed by tissue Doppler of long‐axis shortening. Diagnostic algorithms and definitions of heart failure need to be revised.
Validation of traction force indicator in ventouse devices
Authors: Whitlow B.J. , Tamizian O. , Ashworth J. , Kerry S. , Penna L.K. , Arulkumaran S.
Published: May 2005

Objective: To evaluate whether the traction force indicator in a ventouse device gave an accurate estimation of the force applied. Methods: The study was carried out at the Derby City Hospital. An estimate of measurement errors was made by analyzing the standard deviation of the residuals for 30 Kiwi OmniCup devices (Clinical Innovations, Abingdon, Oxfordshire, England) and a standard industrial spring balance. Results: The measurement errors for the traction forces were very small and acceptable for the OmniCup. The overall estimate of measurement errors was 0.45 kg (1.35 lb). Conclusion: The overall measurement error for the traction force indicator of the OmniCup was found to be very small. Injuries associated the ventouse, such as cephalohematomas and subgaleal hemorrhages, may be minimized if the recommended limits for a safe traction force are not exceeded.
Primary hyperaldosteronism in the cat: A series of 13 cases
Authors: Andrew Roderick , Harvey Andrea M , Tasker Séverine
Published: May 2005

Thirteen cases of feline primary hyperaldosteronism were diagnosed based on clinical signs, serum biochemistry, plasma aldosterone concentration, adrenal imaging and histopathology of adrenal tissue. Two cases presented with blindness caused by systemic hypertension, whilst the remaining 11 cases showed weakness resulting from hypokalaemic polymyopathy. Elevated concentrations of plasma aldosterone and adrenocortical neoplasia were documented in all cases. Seven cases had adrenal adenomas (unilateral in five and bilateral in two) and six had unilateral adrenal carcinomas. Three cases underwent medical treatment only with amlodipine, spironolactone and potassium gluconate; two cases survived for 304 and 984 days until they were euthanased because of chronic renal failure, whilst the third case was euthanased at 50 days following failure of the owner to medicate the cat. Ten cases underwent surgical adrenalectomy following a successful stabilisation period on medical management. Five cases remain alive at the time of writing with follow-up periods of between 240 and 1803 days. Three cases were euthanased during or immediately following surgery because of surgical-induced haemorrhage. One cat was euthanased 14 days after surgery because of generalised sepsis, whilst the remaining cat was euthanased 1045 days after surgery because of anorexia and the development of a cranial abdominal mass. It is recommended that primary hyperaldosteronism should be considered as a differential diagnosis in middle-aged and older cats with hypokalaemic polymyopathy and/or systemic hypertension and should no longer be considered a rare condition.
Basal plasma insulin and homeostasis model assessment (HOMA) are indicators of insulin sensitivity in cats
Authors: Appleton DJ , Rand JS , Sunvold GD
Published: May 2005

The objective of this study was to compare simpler indices of insulin sensitivity with the minimal model-derived insulin sensitivity index to identify a simple and reliable alternative method for assessing insulin sensitivity in cats. In addition, we aimed to determine whether this simpler measure or measures showed consistency of association across differing body weights and glucose tolerance levels. Data from glucose tolerance and insulin sensitivity tests performed in 32 cats with varying body weights (underweight to obese), including seven cats with impaired glucose tolerance, were used to assess the relationship between Bergman's minimal model-derived insulin sensitivity index ( SI), and various simpler measures of insulin sensitivity. The most useful overall predictors of insulin sensitivity were basal plasma insulin concentrations and the homeostasis model assessment (HOMA), which is the product of basal glucose and insulin concentrations divided by 22.5. It is concluded that measurement of plasma insulin concentrations in cats with food withheld for 24 h, in conjunction with HOMA, could be used in clinical research projects and by practicing veterinarians to screen for reduced insulin sensitivity in cats. Such cats may be at increased risk of developing impaired glucose tolerance and type 2 diabetes mellitus. Early detection of these cats would enable preventative intervention programs such as weight reduction, increased physical activity and dietary modifications to be instigated.
Zoledronate induces apoptosis in cells from fibro‐cellular membrane of unicameral bone cyst (UBC)
Authors: Yu John , Chang Seong‐Sil , Suratwala Sanjeev , Chung Woo‐Sik , Abdelmessieh Peter , Lee Hahn‐Jun , Yang Jay , Lee Francis Young‐In
Published: May 2005

Unicameral bone cyst (UBC) is a benign cystic lesion in children which is prone to fracture. Various treatments are available, but recurrence after different types of percutaneous injection therapy can cause bone destruction and pathologic fracture. The potential therapeutic effects of anti‐resorptive agents, such as bisphosphonates, have not been investigated for UBC. The objective of this study was to characterize the cells from the fibro‐cellular membrane of unicameral bone cyst (UBC cells) and to determine whether zoledronate, a nitrogen‐containing bisphosphonate, could induce apoptosis in UBC cells. Flow cytometry and immunoblotting were performed in order to determine whether zoledronate induced apoptosis. Cells derived from normal human trabecular bones were used as controls against UBC cells to compare the effect of zoledronate in inducing apoptosis. Immunohisto/cytochemistry (IHC/ICC) and mini‐array analyses were performed on tissues and cultured cells. Isolated peripheral blood mononuclear cells were incubated with conditioned media from the UBC cells to determine whether they are capable of inducing osteoclastogenesis. UBC membrane is composed of cells staining positively with CD68, SDF‐1, STRO‐1 and RANKL, but in vitro cells showed no staining with antibodies to CD68 and STRO‐1, suggesting that there was a clonal selection of stromal cells during cell culture. UBC cells also express RUNX2 (runt‐related transcription factor‐2, core binding factor‐1), a key transcription factor for osteoblastic differentiation. In addition, media collected from UBC cells induced a generation of multi‐nucleated osteoclast‐like cells of peripheral blood mononuclear cells. Zoledronate induced apoptosis of UBC cells in a dose‐dependent manner. Apoptosis was evidenced by induction of the active cleaved form of caspase‐3. The baseline apoptotic fractions were similar in UBC cells and trabecular bone cells. However, in the overall apoptotic fractions in this study, trabecular bone cells showed 17.2% of apoptosis, significantly lower than 24.2% of UBC cells (p‐value = 0.007). With the various zoledronate concentrations, mean apoptotic fractions of trabecular bone cells was 19.2%, significantly lower than 27.8% of UBC cells (p‐value = 0.040). With GGOH co‐treatment in various zoledronate concentrations, 15.1% apoptosis was shown in trabecular bone cells, which was not significantly lower than 20.6% of UBC cells (p value = 0.076). This data suggests that zoledronate causes apoptosis in both UBC and trabecular bone cells by inhibition of the mevalonate pathway. In addition to the known anti‐osteoclastogenic effect of bisphosphonates, the GGOH inhibitory effects of zoledronate were more prominent in UBC cells than trabecular bone cells, indicating their potential therapeutic role in UBC. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
EDMUND BURKE AND THE MONASTERIES OF FRANCE
Authors: BEALES DEREK
Published: May 2005

Burke's Reflections contains a section of about ten pages on the monasteries of France, deploring not only the confiscation of their property but also the destruction of the institutions themselves, which are defended for their contribution to learning, beauty, and agriculture and for their general social role. Their ‘superstition’ is vindicated as preferable to that of the philosophes. Burke maintains that they could and should have been reformed, rather than suppressed. This discussion of monasteries has been almost wholly ignored by commentators and editors. The following article considers these pages against the reality of French monasticism, itself a neglected theme, and shows their centrality to Burke's critique of the Revolution.
POLITICS AND MILITARY RULE IN CROMWELLIAN BRITAIN
Authors: SMITH DAVID L.
Published: May 2005

The Cromwellian Protectorate. By Barry Coward. Manchester: Manchester University Press, 2002. Pp. viii+248. ISBN 0-7190-4317-4. £14.99.

Cromwell's major generals: godly government during the English Revolution. By Christopher Durston. Manchester: Manchester University Press, 2001. Pp. x+260. ISBN 0-7190-6065-6. £15.99.

John Lambert, parliamentary soldier and Cromwellian major-general, 1619–1684. By David Farr. Woodbridge: Boydell Press, 2003. Pp. x+268. ISBN 1-84383-0043. £50.00.

Oliver Cromwell, soldier: the military life of a revolutionary at war. By Alan Marshall. London: Brassey's, 2004. Pp. 320. ISBN 1-85753-343-7. £20.00.

Arguably the closest that Britain has ever come to military rule was at certain times during the period from 1647 to 1660. English forces conquered Ireland and Scotland in 1649–50 and 1650–1 respectively, and the two kingdoms were then forcibly ‘settled’ and incorporated into an English commonwealth. In England, meanwhile, the army repeatedly intervened to purge or disperse parliaments: in 1647, 1648, 1653, 1654, and 1659 (twice). For about fifteen months, in 1655–7, England and Wales were governed by major-generals who exercised sweeping powers to enforce order, preserve security, and enforce a ‘reformation of manners’. All these developments raise profound questions about the nature of Cromwellian government in general, and the relationship between politics and military rule in particular. Austin Woolrych argued, some years ago, that the Cromwellian Protectorate was not a military dictatorship in any meaningful sense. He suggested that the regime possessed neither the will, nor the means, to impose military rule, that it generally respected the rule of law, and that the military presence in local government even during the time of the major-generals was limited. Yet the nature of the interaction between the military and the political – in shaping government, in influencing policies, and in forming the careers of Oliver Cromwell and other leading figures – remains complex and merits much fuller exploration. The four books under review address these and related themes from a range of different viewpoints.
POLITICAL INFORMATION IN THE SEVENTEENTH CENTURY
Authors: LOVEMAN KATE
Published: May 2005

Reading, society and politics in early modern England. Edited by Kevin Sharpe and Steven N. Zwicker. Cambridge: Cambridge University Press, 2003. Pp. ix+363. ISBN 0-521-82434-6. £50.00.

The politics of information in early modern Europe. Edited by Brendan Dooley and Sabrina A. Baron. London and New York: Routledge, 2001. Pp. viii+310. ISBN 0-415-20310-4. £75.00.

Literature, satire and the early Stuart state. By Andrew McRae. Cambridge: Cambridge University Press, 2004. Pp. ix+250. ISBN 0-521-81495-2. £45.00.

The writing of royalism, 1628–1660. By Robert Wilcher. Cambridge: Cambridge University Press, 2001. Pp. xii+403. ISBN 0-521-66183-8. £45.00.

Politicians and pamphleteers: propaganda during the English civil wars and interregnum. By Jason Peacey. Aldershot: Ashgate, 2004. Pp. xi+417. ISBN 0-7546-0684-8. £59.95.

The ingenious Mr. Henry Care, Restoration publicist. By Lois G. Schwoerer. Baltimore and London: Johns Hopkins University Press, 2001. Pp. xxvii+349. ISBN 0-8018-6727-4. £32.00.

In 1681 the Italian newswriter Giacomo Torri incurred the wrath of the French ambassador to the Venetian Republic with his anti-French reporting. The ambassador ordered Torri to ‘cease and desist or be thrown into the canal’. Torri, who was in the pay of the Holy Roman Emperor, responded to the ambassador's threat with a report that ‘the king of France had fallen from his horse, and that this was a judgement of God’. Three of the ambassadors' men were then found attacking Torri ‘by someone who commanded them to stop in the name of the Most Excellent Heads of the Council of Ten … but they replied with certain vulgarities, saying they knew neither heads nor councils’. Discussed by Mario Infelise in Brendan Dooley and Sabrina Baron's collection, this was a very minor feud in the seventeenth-century battles over political information, but it exemplifies several of the recurring themes of the books reviewed here. First, the growing recognition by political authorities across Europe that news was a commodity worthy of investment. Secondly, the variety of official and unofficial sanctions applied in an attempt to control the market for news publications. Thirdly, the recalcitrance of writers and publishers in the face of these sanctions: whether motivated by payment or principle, disseminators of political information showed great resourcefulness in frustrating attempts to limit their activities. These six books investigate aspects of seventeenth-century news and politics or, alternatively, seventeenth-century literature and politics – the distinction between ‘news’ and certain literary genres being, as several of these authors show, often difficult to make.
Models of knowledge and systems of governance
Authors: ANTONELLI CRISTIANO
Published: May 2005

The analysis of the main features of knowledge, in terms of domain, characteristics and processes makes it possible to trace significant shifts in the economics of knowledge. Changing emphasis about the role of knowledge appropriability, divisibility and tradability has provided different solutions to the knowledge trade-off. Three different and rival concepts of technological knowledge can be identified: (a) knowledge as a public good, (b) knowledge as a proprietary good, (c) knowledge as a localized, collective and complex, path dependent activity. Such a shift has relevant implications in terms of governance mechanisms, strategic attitude of agents and public policy making.
Introduction to the inaugural issue by the Editor-in-Chief
Authors: Hodgson Geoffrey M.
Published: May 2005

Major shifts in thinking among economists and other social scientists in recent years have prepared the ground for the launch of the Journal of Institutional Economics. Within economics, for example, after a period of neglect from the earlier to the later decades of the twentieth century, the study of the nature and role of institutions has become a central topic. Explanations of economic growth and development used to focus on inputs, production functions, and outputs, often neglecting the institutional structures that constrain or empower individuals, and frame their incentives and disincentives. Accordingly, for a long time the firm was treated as a ‘black box’, with little regard to the structural determinants of its existence, boundaries, and performance. However, the study of the firm changed dramatically in the 1970s when Oliver Williamson, building on the earlier work of Ronald Coase and others, opened the black box to investigate the firm as an institution. Similarly, in a pioneering series of works, Douglass North has investigated the role of institutions in the historical development of the modern capitalism. There are many other examples of important achievements in this area, too numerous to mention here. The outcome is that institutions have become a central topic of analysis for economists.
Aspects of Self-Knowledge About Activities
Authors: Bornholt Lauren J.
Published: May 2005

Abstract. This project examined the proposal that self-concepts integrate aspects of self-knowledge in relation to activities. The proposed integrated model was applied to self-concepts about current and future performance, natural talent, effort, and task difficulty of reading, number, and drawing. The participants were 5- to 12-year-old children in Study 1 (N = 241) and Study 2 (N = 225). Responses were unbiased by order effects and socioeconomic indicators. Study 1 showed that the integrated model was a good fit to the responses. Alternative models about the person and about activities did not fit the responses well. The few effects of age and gender self-stereotyping were on particular aspects and not across all aspects of activities. Study 2 replicated the findings. Results supported the integrated model of children's self-concepts that provides a sound basis for brief, meaningful, and useful self-concept inventories for children. The model is readily extended to other activities, with applications to education and clinical settings.
Temperature dependence of the first pressure derivative of the isothermal bulk modulus for solid materials at zero pressure: Application to MgO
Authors: Li Heping , Xu Liping , Liu Cong‐qiang
Published: May 2005

Because of the significance of the first pressure derivative of the isothermal bulk modulus (K′T,0) at temperature, T, and zero pressure, a thermodynamic model was developed to calculate K′T,0 and its temperature derivative ∂K′T,0/∂T. This model constructs a differential equation of K′T,0 with respect to temperature based on the well‐known empirical linear relationship of the Anderson‐Grüneisen parameter, δT, and the compression ratio, η. By solving this differential equation, we derived both K′T,0 and ∂K′T,0/∂T at a temperature, T, and zero pressure in terms of the known parameters of thermal expansivity, α, isobaric heat capacity, CP, and isothermal bulk modulus, KT at ambient pressure, and K′T at a reference temperature, T0, and ambient pressure. The reliability of this model was confirmed by comparing the modeled MgO results with previous data. This model will provide a powerful tool for determining the equation of state and the thermoelastic properties of solid materials at high temperatures and high pressures.
Temperature and melting of laser-shocked iron releasing into an LiF window
Authors: Huser G. , Koenig M. , Benuzzi-Mounaix A. , Henry E. , Vinci T. , Faral B. , Tomasini M. , Telaro B. , Batani D.
Published: May 2005

Absolute reflectivity and self-emission diagnostics are used to determine the gray-body equivalent temperature of laser-shocked iron partially releasing into a lithium fluoride window. Pressure and reflectivity are measured simultaneously by means of velocity interferometer system for any reflector interferometers. In the temperature-pressure plane, a temperature plateau in the release is observed which is attributed to iron’s melting line. Extrapolation of data leads to a melting temperature at Earth’s inner-outer core boundary of 7800±1200K, in good agreement with previous works based on dynamic compression. Shock temperatures were calculated and found to be in the liquid phase.
Synthesis of ZnO nanocrystals by subsequent implantation of Zn and O species
Authors: Lee J. K. , Tewell C. R. , Schulze R. K. , Nastasi M. , Hamby D. W. , Lucca D. A. , Jung H. S. , Hong K. S.
Published: May 2005

We report the preparation of ZnO nanocrystals embedded in a SiO2 matrix formed using sequential zinc and oxygen ion implantations. The optical absorption spectra and photoemission spectra of zinc implanted and zinc/oxygen coimplanted silica show that the first zinc implantation produces zinc clusters and that the subsequent oxygen implantation following the zinc implantation rearranges the distribution of zinc and oxygen ions at an atomic level. While thermal annealing of Zn only implanted silica leads to the formation of Zn nanocrystals, thermal annealing of zinc/oxygen coimplanted silica promotes the growth of ZnO nanocrystals. The absorption and photoluminescence spectra show that ZnO nanocrystals form in an amorphous SiO2 matrix and that their systematic change as a function of annealing temperature corresponds to the typical correlation between the increase of particle size and a redshift in near-band-edge emission.
Study of extended-defect formation in Ge and Si after H ion implantation
Authors: Akatsu T. , Bourdelle K. K. , Richtarch C. , Faure B. , Letertre F.
Published: May 2005

Extended defects formed after hydrogen implantation into Si and Ge (100) substrates and subsequent thermal anneals were investigated by transmission electron microscopy. The majority of the extended defects formed in both materials were platelet-like structures lying on {100} and {111} planes. We found {100} platelets not only parallel but also perpendicular to the surface. In Ge wafers, high density of {311} defects and nanobubbles with the average size of 2 nm were observed. The difference between two materials can be attributed to the weaker strength of Ge–H bond.
Electrical conduction mechanism in silicon nitride and oxy-nitride-sputtered thin films
Authors: Vila M. , Román E. , Prieto C.
Published: May 2005

We have studied the effect of reactive and nonreactive sputtering preparations on the composition and properties of silicon nitride thin films. Films were prepared from both silicon nitride ceramic and pure silicon targets under different Ar∕N2 gas mixtures. For the different resulting samples, we have performed optical, x-ray photoemission spectroscopy (XPS), and transport measurements. The preparation conditions change the sample atomic composition and the effect of oxygen in the films, which in turn determines the dominant conduction mechanism. It becomes important to determine both the nonstoichiometry of the film and the phase where the oxygen is incorporated. Oxygen may appear as silicon oxide, forming a secondary phase inside silicon nitride; or it may consist of silicon oxy-nitride phases. The presence of these different phases, as revealed by XPS, determines the electrical properties and conduction mechanisms. Samples presenting space-charge-limited current as the dominant conduction mechanism correspond to those where a silicon oxy-nitride phase is formed (that becomes Ohmic for overstoichiometric Si content samples), while a Poole–Frenkel conduction behavior is characteristic of the silicon nitride phase.
Gauge invariance of the spin-other-orbit contribution to the g-tensors of electron paramagnetic resonance
Authors: Patchkovskii S. , Strong R. T. , Pickard C. J. , Un Sun
Published: May 2005

The spin-other-orbit (SOO) contribution to the g-tensor (ΔgSOO) of electron paramagnetic resonance arises due to the interaction of electron-spin magnetic moment with the magnetic field produced by the orbital motion of other electrons. A similar mechanism is responsible for the leading term in nuclear magnetic-shielding tensors σ. We demonstrate that analogous to σ, paramagnetic ΔgSOO contribution exhibits a pronounced dependence on the choice of the magnetic-field gauge. The gauge corrections to ΔgSOO are similar in magnitude, and opposite in sign, to the paramagnetic SOO term. We calculate gauge-invariant ΔgSOO values using gauge-including atomic orbitals and density-functional theory. For organic radicals, complete gauge-invariant ΔgSOO values typically amount to less than 500partspermillion (ppm), and are small compared to other g-tensor contributions. For the first-row transition-metal compounds, ΔgSOO may contribute several thousand ppm to the g-tensor, but are negligible compared to the remaining deviations from experiment. With popular choices for the magnetic-field gauge, the individual gauge-variant contributions may be an order of magnitude higher, and do not provide a reliable estimation of ΔgSOO.
Optical excitation of nanoelectromechanical oscillators
Authors: Ilic B. , Krylov S. , Aubin K. , Reichenbach R. , Craighead H. G.
Published: May 2005

We report a method of optical excitation of nanomechanical cantilever-type oscillators. The periodic driving signal with a controlled modulation amplitude was provided by a 415 nm diode laser, wherein the laser spot was located at some distance away from the clamped end of the cantilever. The measured resonant response of the cantilever was obtained at distances in excess of 160μm with varying oscillator dimensions. The effectiveness of the driving mode is studied for different combinations of materials, namely Si–SiO2 and Si3N4–SiO2. These observations were considered within the theoretical framework of the mechanism of heat transfer. We show that measurable amplitudes of vibrations can be obtained at temperature changes much less than 1°.
X-ray photoelectron spectroscopy for resistance-capacitance measurements of surface structures
Authors: Ertas Gulay , Demirok U. Korcan , Atalar Abdullah , Suzer Sefik
Published: May 2005

In x-ray photoemission measurements, differential charging causes the measured binding energy difference between the Si 2p of the oxide and the silicon substrate to vary nonlinearly as a function of the applied external dc voltage stress, which controls the low-energy electrons going into and out of the sample. This nonlinear variation is similar to the system where a gold metal strip is connected to the same voltage stress through an external 10 Mohm series resistor and determined again by x-ray photoelectron spectroscopy (XPS). We utilize this functional resemblance to determine the resistance of the 4 nm SiO2 layer on a silicon substrate as 8 Mohm. In addition, by performing time-dependent XPS measurements (achieved by pulsing the voltage stress), we determine the time constant for charging∕discharging of the same system as 2.0 s. Using an equivalent circuit, consisting of a gold metal strip connected through a 10 Mohm series resistor and a 56 nF parallel capacitor, and performing time-dependent XPS measurements, we also determine the time constant as 0.50 s in agreement with the expected value (0.56 s). Using this time constant and the resistance (8.0 Mohm), we can determined the capacitance of the 4 nm SiO2 layer as 250 nF in excellent agreement with the calculated value. Hence, by application of external dc and pulsed voltage stresses, an x-ray photoelectron spectrometer is turned into a tool for extracting electrical parameters of surface structures in a noncontact fashion.
The propagation of electromagnetic wave in gradually ionized plasmas
Authors: He Bin , Chang Tie-qiang
Published: May 2005

A simple model is proposed to describe the propagation of the electromagnetic (EM) wave in gradually ionized plasmas. Particle simulation with particle-in-cell code is performed to verify this model. The frequency spectrum of the EM wave is studied in detail, and a new way to broaden the frequency of the wave effectively is proposed. The reflection and transmission of the EM wave in such plasmas are also discussed.
Microbubble-based model analysis of liquid breakdown initiation by a submicrosecond pulse
Authors: Qian J. , Joshi R. P. , Kolb J. , Schoenbach K. H. , Dickens J. , Neuber A. , Butcher M. , Cevallos M. , Krompholz H. , Schamiloglu E. , Gaudet J.
Published: May 2005

An electrical breakdown model for liquids in response to a submicrosecond (∼100ns) voltage pulse is presented, and quantitative evaluations carried out. It is proposed that breakdown is initiated by field emission at the interface of pre-existing microbubbles. Impact ionization within the microbubble gas then contributes to plasma development, with cathode injection having a delayed and secondary role. Continuous field emission at the streamer tip contributes to filament growth and propagation. This model can adequately explain almost all of the experimentally observed features, including dendritic structures and fluctuations in the prebreakdown current. Two-dimensional, time-dependent simulations have been carried out based on a continuum model for water, though the results are quite general. Monte Carlo simulations provide the relevant transport parameters for our model. Our quantitative predictions match the available data quite well, including the breakdown delay times and observed optical emission.
Atomic layer deposition of high-κ dielectrics on nitrided silicon surfaces
Authors: Xu Ye , Musgrave Charles B.
Published: May 2005

An atomistic mechanism for the initiation of atomic layer deposition (ALD) of hafnium oxide (HfO2) on nitrided silicon surfaces was investigated using density functional theory. Reactions involving two different metal precursors are studied. Hf[N(CH3)2]4 does not form an adsorbed molecular complex, while HfCl4 has an adsorption energy of 0.30eV. The ALD ligand exchange reaction is direct and 0.19eV exothermic for Hf[N(CH3)2]4 with a barrier of 0.63eV, while it is mediated by a complex intermediate and 0.40eV endothermic for HfCl4 with a barrier of 0.97eV. These results indicate that Hf[N(CH3)2]4 is both thermodynamically and kinetically superior to HfCl4 for the initial ALD of HfO2 on nitrided silicon surfaces.
Why is iridium the best substrate for single crystal diamond growth?
Authors: Verstraete Matthieu J. , Charlier Jean-Christophe
Published: May 2005

The synthesis of heteroepitaxial monocrystalline diamond films has been of technological and scientific interest for several decades. Using chemical vapor deposition techniques, polycrystalline diamond has been successfully grown on many substrates. However, iridium emerges in providing highly oriented films, significantly better than any other transition metals. In the present work we propose an ab initio density functional study of the interaction of diamond with different substrates used experimentally. The origin of iridium’s specific behavior is investigated. The kinetics of carbon atoms in the substrate lattice is found to play a key role, determining the nucleation mechanisms and hence the quality of the final diamond film.
Study of strain relaxation in Si/SiGe metal-oxide-semiconductor field-effect transistors
Authors: Olsen S. H. , O’Neill A. G. , Dobrosz P. , Bull S. J. , Driscoll L. S. , Chattopadhyay S. , Kwa K. S. K.
Published: May 2005

We report a study of strained Si metal-oxide-semiconductor field-effect transistors (MOSFET’s) fabricated using a high thermal budget. The impact of Si channel strain on MOSFET performance, leakage current, and yield is investigated for Si1−xGex virtual substrates having Ge compositions varying from 0% to 30%. Increasing the Ge fraction in the SiGe virtual substrate increases the amount of tensile strain in the Si layer and consequently increases the electron mobility. High levels of strain, however, reduce the critical thickness of strained Si, above which Si becomes metastable and susceptible to relaxation during high-temperature device fabrication. Increasing the Ge composition in the virtual substrate up to 30% is shown to result in significant enhancements in MOSFET drain current and transconductance due to increased strain in the device channels. However, cross-wafer electrical yield data as a function of Ge composition are reported and show that increasing Ge compositions above 15% simultaneously reduces device yield. Off-state leakage current and gate oxide interface trap density are also shown to increase significantly when the Ge content in the virtual substrate is raised above 25%. Trade-offs between device performance and wafer yield are thus presented. The results identify the appropriate parameter window for virtual substrate Ge composition if acceptable MOSFET on-state performance, off-state performance, device yield, and reliability are to be achieved using a high thermal budget process. Detailed physical and electrical analyses have been carried out in order to understand the causes of the degraded performance for high Ge content virtual substrates. The reduction in yield with increasing Ge composition is shown to be related to a combination of strain relaxation and as-grown material quality. The strain state has been studied using Raman spectroscopy, Schimmel etching, and transmission electron microscopy, in conjunction with electrical measurements. The ability of techniques commonly used to assess strain relaxation is critically examined. The degraded electrical performance for strained Si/Si0.70Ge0.30 devices is shown to correlate well with the presence of surface threading dislocations resulting from strain relaxation. The relative effects of as-grown material quality and strain relaxation on device performance have also been investigated. The impact of device operating conditions on performance enhancements has further been analyzed and implications for the design of both n- and p-channel strained Si/SiGe MOSFET’s are discussed.
Hydrogen content in doped and undoped BaPrO3 and BaCeO3 by cold neutron prompt-gamma activation analysis
Authors: Jones Camille Y. , Wu Jian , Li LiPing , Haile Sossina M.
Published: May 2005

Proton uptake in undoped and Y-doped BaPrO3 has been measured by cold neutron prompt-gamma activation analysis, and compared to the proton uptake in Gd-doped BaCeO3, as determined by the same technique. The conventional proton incorporation model of perovskites in which oxygen ion vacancies, generated by the introduction of the trivalent dopant onto the tetravalent perovskite site, are filled with hydroxyl groups upon exposure of the sample to H2O containing atmospheres, predicts that the proton concentration in such materials should be no greater than the dopant concentration. In contradiction to this model, the proton concentration in BaPr1−xYxO3 after humidification is as much as three times greater than the dopant concentration, and even undoped samples contain a high concentration of protons. Moreover, x-ray photoemission spectra suggest that the Pr oxidation state is lowered upon hydration. In contrast, BaCe0.9Y0.1O3 shows a typical hydrogen concentration, of close to 90% of the yttrium concentration. The results are interpreted in terms of the variable valence of Pr, which can become reduced from the 4+ to the 3+ oxidation state upon exposure to water, and effectively behaves as a self-dopant within the structure.