bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Myocardial Infarction and Coronary Artery Bypass Grafting Outcomes in Specialty and General Hospitals: Analysis of State Inpatient Data
Authors: Cram Peter , Bayman Levent , Popescu Joanna , Vaughan‐Sarrazin Mary S.
Published: December 2009

Objective. Compare characteristics and outcomes of patients hospitalized in specialty cardiac and general hospitals for acute myocardial infarction (AMI) and coronary artery bypass grafting (CABG).

Data. 2000–2005 all‐payor administrative data from Arizona, California, Texas, and Wisconsin.

Study Design. We identified patients admitted to specialty and competing general hospitals with AMI or CABG and compared patient demographics, comorbidity, and risk‐standardized mortality in specialty and general hospitals.

Principal Findings. Specialty hospitals admitted a lower proportion of women and blacks and treated patients with less comorbid illness than general hospitals. Unadjusted in‐hospital AMI mortality for Medicare enrollees in specialty and general hospitals was 6.1 and 10.1 percent (p<.0001) and for non‐Medicare enrollees was 2.8 and 4.0 percent (p<.04). Unadjusted in‐hospital CABG mortality for Medicare enrollees in specialty and general hospitals was 3.2 and 4.7 percent (p<.01) and for non‐Medicare enrollees was 1.1 and 1.8 percent (p=.02). After adjusting for patient characteristics and hospital volume, risk‐standardized in‐hospital mortality for all AMI patients was 2.7 percent for specialty hospitals and 4.1 percent for general hospitals (p<.001) and for CABG was 1.5 percent for specialty hospitals and 2.0 percent for general hospitals (p=.07).

Conclusions. In‐hospital mortality in specialty hospitals was lower than in general hospitals for AMI but similar for CABG. Our results suggest that specialty hospitals may offer significantly better outcomes for AMI but not CABG.
Alagebrium attenuates acute methylglyoxal‐induced glucose intolerance in Sprague‐Dawley rats
Authors: Dhar Arti , Desai Kaushik M , Wu Lingyun
Published: December 2009

Background and purpose:  Alagebrium is a breaker of cross‐links in advanced glycation endproducts. However, the acute effects of alagebrium on methylglyoxal (MG), a major precursor of advanced glycation endproducts have not been reported. MG is a highly reactive endogenous metabolite, and its levels are elevated in diabetic patients. We investigated whether alagebrium attenuated the acute effects of exogenous MG on plasma MG levels, glucose tolerance and distribution of administered MG in different organs in Sprague‐Dawley rats.

Experimental approach:  We measured MG levels (by HPLC), glucose tolerance, adipose tissue glucose uptake, GLUT4, insulin receptor and insulin receptor substrate 1 (IRS‐1) protein expression, and phosporylated IRS‐1 in rats treated with MG at doses of either 17.25 mg·kg−1 i.p. (MG‐17 i.p.) or 50 mg·kg−1 i.v. (MG‐50 i.v.) with or without alagebrium, 100 mg·kg−1 i.p.

Key results:  Alagebrium attenuated the increased MG levels in the plasma, aorta, heart, kidney, liver, lung and urine after MG administration. In MG‐treated rats, glucose tolerance was impaired, plasma insulin levels were higher and insulin‐stimulated glucose uptake by adipose tissue was reduced, relative to the corresponding control groups. In rats treated with MG‐50 i.v., GLUT4 protein expression and IRS‐1 tyrosine phosphorylation were decreased. Alagebrium pretreatment attenuated these effects of MG. In an in vitro assay, alagebrium reduced the amount of detectable MG.

Conclusions and implications:  Alagebrium acutely attenuated MG‐induced glucose intolerance, suggesting a possible preventive role for alagebrium against the harmful effects of MG.
Evidence that the plant cannabinoid cannabigerol is a highly potent α2‐adrenoceptor agonist and moderately potent 5HT1Areceptor antagonist
Authors: Cascio MG , Gauson LA , Stevenson LA , Ross RA , Pertwee RG
Published: December 2009

Background and purpose: Cannabis is the source of at least seventy phytocannabinoids. The pharmacology of most of these has been little investigated, three notable exceptions being Δ9‐tetrahydrocannabinol, cannabidiol and Δ9‐tetrahydrocannabivarin. This investigation addressed the question of whether the little‐studied phytocannabinoid, cannabigerol, can activate or block any G protein‐coupled receptor.

Experimental approach: The [35S]GTPγS binding assay, performed with mouse brain membranes, was used to test the ability of cannabigerol to produce G protein‐coupled receptor activation or blockade. Its ability to displace [3H]CP55940 from mouse CB1and human CB2cannabinoid receptors and to inhibit electrically evoked contractions of the mouse isolated vas deferens was also investigated.

Key results: In the brain membrane experiments, cannabigerol behaved as a potent α2‐adrenoceptor agonist (EC50= 0.2 nM) and antagonized the 5‐HT1Areceptor agonist,R‐(+)‐8‐hydroxy‐2‐(di‐n‐propylamino)tetralin (apparentKB= 51.9 nM). At 10 µM, it also behaved as a CB1receptor competitive antagonist. Additionally, cannabigerol inhibited evoked contractions of the vas deferens in a manner that appeared to be α2‐adrenoceptor‐mediated (EC50= 72.8 nM) and displayed significant affinity for mouse CB1and human CB2receptors.

Conclusions and implications: This investigation has provided the first evidence that cannabigerol can activate α2‐adrenoceptors, bind to cannabinoid CB1and CB2receptors and block CB1and 5‐HT1Areceptors. It will now be important to investigate why cannabigerol produced signs of agonism more potently in the [35S]GTPγS binding assay than in the vas deferens and also whether it can inhibit noradrenaline uptake in this isolated tissue and in the brain.
Transient supersensitivity to α‐adrenoceptor agonists, and distinct hyper‐reactivity to vasopressin and angiotensin II after denervation of rat tail artery
Authors: Tripovic Diana , Pianova Svetlana , McLachlan Elspeth M , Brock James A
Published: December 2009

Background and purpose: Vascular ‘denervation’ hyper‐reactivity has generally been investigated 1–2 weeks after administration of chemicals that temporarily prevent transmitter release, but do not necessarily inactivate the neuronal noradrenaline transporters (NETs). We have investigated the reactivity of rat tail arteries over longer periods after removing the terminals by surgical denervation.

Experimental approach: Two and 7 weeks after denervation, myography was used to assess contractions of isolated arterial segments to phenylephrine, methoxamine, clonidine, vasopressin and angiotensin II (AII). Denervation was confirmed by lack of tyrosine hydroxylase immunoreactive nerve terminals.

Key results: The NET inhibitor, desmethylimipramine, increased the pEC50for phenylephrine in control, but not denervated arteries after both 2 and 7 weeks. Relative to controls, pEC50s for phenylephrine (with desmethylimipramine), methoxamine, clonidine and vasopressin were increased at 2 but not 7 weeks after denervation. The pEC50for phenylephrine in the absence of desmethylimipramine was greater than control after both 2 and 7 weeks' denervation. The maximum contraction to vasopressin was larger than in controls at 2 but not 7 weeks after denervation, whereas contractions to AII were markedly enhanced at both time points.

Conclusions and implications: Increased vascular reactivity to α1‐ and α2‐adrenoceptor agonists, and vasopressin is transient following denervation. After 7 weeks, increased reactivity to phenylephrine can be entirely accounted for by the loss of NETs. Maintained supersensitivity to AII indicates that denervation differentially and selectively affects vascular reactivity to circulating vasoconstrictor agents. This might explain persistent vasoconstriction in denervated skin of humans after nerve injuries.
TREK‐1 channels do not mediate nitrergic neurotransmission in circular smooth muscle from the lower oesophageal sphincter
Authors: Zhang Y , Miller DV , Paterson WG
Published: December 2009

Background and purpose:  The ionic mechanisms underlying nitrergic inhibitory junction potentials (IJPs) in gut smooth muscle remain a matter of debate. Recently, it has been reported that opening of TWIK‐related K+ channel 1 (TREK‐1) K+ channels contributes to the nitrergic IJP in colonic smooth muscle. We investigated the effects of TREK‐1 channel blockers on nitrergic neurotransmission in mouse and opossum lower oesophageal sphincter (LOS) circular smooth muscle (CSM).

Experimental approach:  The effects of TREK‐1 channel blockers were characterized pharmacologically in murine and opossum gut smooth muscle using conventional intracellular and tension recordings.

Key results:  In LOS, L‐methionine depolarized the resting membrane potential (RMP) but did not inhibit the nitrergic IJP. Cumulative application of theophylline hyperpolarized the RMP and inhibited the nitrergic IJP concentration dependently. The induced membrane hyperpolarization was prevented by pre‐application of caffeine, but not by 1H‐[1,2,4]oxadiazolo‐[4,3‐a]quinoxalin‐1‐one. 8‐Br‐cAMP significantly hyperpolarized membrane potential and increased the amplitude of the nitrergic IJP. In opossum LOS muscle strips, L‐methionine increased resting tone but had no effect on nerve‐mediated LOS relaxation. On the other hand, theophylline markedly inhibited tone. In CSM from mouse proximal colon, L‐methionine caused modest inhibition of nitrergic IJPs.

Conclusions and implications:  TREK‐1 channels were not involved in the nitrergic IJP in LOS CSM. Not only does L‐methionine have no effect on the nitrergic IJP or LOS relaxation, but the effect of theophylline appears to be due to interruption of Ca2+‐releasing pathways (i.e. caffeine‐like effect) rather than via blockade of TREK‐1 channels.
Colitis affects the smooth muscle and neural response to motilin in the rabbit antrum
Authors: Depoortere Inge , Thijs Theo , Janssen Sara , De Smet Betty , Tack Jan
Published: December 2009

Background and purpose: The underlying mechanisms of gastric dysfunction during or after an episode of intestinal inflammation are poorly understood. This study investigated the effects of colitis on the contractile effects of motilin, an important endocrine regulator of gastric motility, in the antrum.

Experimental approach: Myeloperoxidase (MPO) activity, NF‐κB activity and motilin receptor density were determined in the antrum of rabbits 5 days after the induction of 2,4,6‐trinitrobenzenesulphonic acid colitis. Smooth muscle and neural responses to motilin were studied in antral smooth muscle stripsin vitro.

Key results: Colitis did not affect MPO activity, but increased NF‐κB activity in the antrum. Motilin receptor density in the antrum was not affected. Under control conditions, motilin induced a slowly developing tonic smooth muscle contraction. Five days post‐inflammation, tonic contractions to motilin were reduced and preceded by a rapid initial contraction. Other kinases were recruited for the phosphorylation of myosin light chain (MLC) (a multi‐functional MLC kinase), and for the inhibition of MLC phosphatase (Rho kinase in addition to protein kinase C) to mediate the motilin‐induced contractions during inflammation. Colitis potentiated the cholinergic neural on‐contractions in the antrum. This was associated with a hyper‐reactivity to motilin and an increased muscle response to ACh.

Conclusions and implications: Colitis altered the course of the motilin‐induced smooth muscle contraction in the antrum. This involved changes in the kinases phosphorylating MLC. Increased cholinergic excitability to motilin in the antrum may play a role in the pathogenesis of inflammation‐associated gastric motility disorders.
Gender, Politics and Policy Change: The Case of Welfare Reform Under New Labour
Authors: Annesley Claire
Published: December 2009

Politics and gender scholarship is increasingly seeking to understand the relationship between the presence of women in politics and gendered policy outcomes – the substantive representation of women (SRW). Yet its focus remains squarely on the activities of ‘critical actors’ in parliaments and women's policy agencies and on ‘feminist’ rather than ‘mainstream’ policy areas. In contrast, this article investigates the impact of feminist actors in a range of institutional settings on recent processes of welfare reform in the UK. It finds that the gendered welfare reform introduced by New Labour was initiated and pushed through by a coalition of committed feminist actors across a range of institutions. Crucially, the reforms relied on the existence of ‘strategic actors’ and ‘gate openers’, defined as feminist actors in positions of significant institutional power. It makes a contribution to the actor-centred SRW scholarship, develops an institutionalist approach to this research and identifies the need for a political economy perspective to understanding how women can shape policy outcomes.
A Novel Technique for Tethered Dialysis Catheter Removal Using the Laser Sheath
Authors: Carrillo Roger G. , Garisto Juan D. , Salman Loay , Merrill Donna , Asif Arif
Published: December 2009

Traction and cutdown techniques can successfully remove a tunneled dialysis catheter (TDC) in a great majority of patients. However, these methods may not be successful in patients with catheters that are tethered or attached to the central veins or the atrium. A forceful application of traction can lead to catheter breakage with subsequent retention of the broken piece and carries a potential risk of vascular and atrial wall avulsion. Open thoracotomy has been employed to remove an attached TDC. However, this procedure is invasive and bears a significant morbidity. This report presents three cases of tethered TDCs that underwent laser sheath extraction. The TDCs had been in place for an average of 26 months. The patients underwent initial unsuccessful removal attempt using the traction method with surgical exploration all the way to the venotomy site. The laser technique that is used to remove pacemaker/implantable cardioverter defibrillator leads was then applied to these stuck catheters. All three catheters were successfully removed without any damage to the catheter, central veins, or the right atrium. There were no retained catheter fragments left in the central veins or the atrium. One patient demonstrated a significant thrombus that extended from the tip of the catheter all the way to the right ventricle. The external sheath of the laser device successfully aspirated the thrombus. There were no procedure‐related complications. In this small series, a laser sheath successfully extracted tethered dialysis catheters. The study found the procedure to be effective, easy to perform, and minimally invasive. We suggest that this approach be considered for the removal of tethered catheters that cannot be removed using traditional approaches.
Retrograde Angiography and the Risk of Arteriovenous Fistula Perforation
Authors: Salman Loay , Asif Arif , Beathard Gerald A.
Published: December 2009

Assessment of the inflow segment of an arteriovenous fistula is mandatory for optimum access evaluation. Retrograde angiography (RA) is routinely used to image this region of the access system. Traditionally, RA is performed by manually occluding the outflow track of an arteriovenous fistula (AVF) and forcing the radiocontrast into the inflow segment against arterial pressure. While this technique is largely successful in visualizing the juxta‐anastomotic region, anastomosis and a portion of the feeding artery, the approach carries a potential risk of vascular rupture between the occluded portion of the fistula and the anastomosis. This article presents six cases of fistulas that suffered vascular rupture during RA. In three cases, vascular damage occurred prior to the application of angioplasty. The remaining cases suffered perforation after angioplasty. Balloon tamponade was successful in salvaging two fistulas. Another AVF with a perforation did not require any intervention to maintain flow. The complication was successfully managed in one AVF by the insertion of an endovascular stent graft. Two fistulas were lost due to vascular damage. This report demonstrates that RA performed by occluding the outflow track of an AVF to assess the results of angioplasty of an inflow stenosis can result in vascular rupture. There is a risk of such adversity even before the application of angioplasty in this region. It is suggested that the first of these be avoided and the latter be done with care.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Blood–Membrane Interactions During Dialysis
Authors: Huang Zhongping , Gao Dayong , Letteri Jeffrey J. , Clark William R.
Published: December 2009

In extracorporeal renal replacement therapies, the dialyzer is not only the site at which solute removal occurs but also the extracorporeal circuit component having the largest surface area exposed to blood. Therefore, it is not surprising that interactions between blood components and the dialyzer membrane influence the dialysis procedure in several ways. Based on engineering principles, fluid flow along a surface such as membrane results in the development of a boundary layer which can influence solute removal. Furthermore, the exposure of blood to any extracorporeal artificial surface results in the activation of several pathways within the body, including those involving coagulation and complement activation. One of the byproducts of this generalized activation process is protein adsorption to the membrane surface, another phenomenon which can have a significant impact on solute removal. In this article, a detailed review of the ways in which blood–membrane interactions influence solute removal during hemodialysis and related therapies is provided. The influences of secondary membrane formation and boundary layer/concentration polarization effects on solute removal are specifically discussed. Furthermore, the importance of adsorption as a specific removal mechanism for low‐molecular weight proteins by highly permeable synthetic membranes is highlighted.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: The Implantable Artificial Kidney
Authors: Fissell William H. , Roy Shuvo
Published: December 2009

The confluence of an increasing prevalence of end‐stage renal disease (ESRD), clinical trial data suggestive of benefit from quotidian dialysis, and ongoing cost/benefit reanalysis of healthcare spending have stimulated interest in technological improvements in provision of ESRD care. For the last decade, our group has focused on enabling technologies that would permit a paradigm shift in dialysis care similar to that brought by implantable defibrillators to arrhythmia management. Two significant barriers to wearable or implantable dialysis persist: package size of the dialyzer and water requirements for preparation of dialysate. Decades of independent research into highly efficient membranes and cell‐based bioreactors culminated in a team effort to develop an implantable version of the University of Michigan Renal Assist Device. In this review, the rationale for the design of the implantable artificial kidney is described.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Renal Cell Therapy and Beyond
Authors: Song Joon Ho , Humes H. David
Published: December 2009

Although current dialysis techniques have transformed acute and chronic renal failure from uniformly fatal clinical disorders into treatable diseases, these therapies replace only the water and solute clearance function of the kidney and have reached a point where little further therapeutic improvement can be anticipated. In addition to their metabolic and endocrine functions, renal tubule cells presumably play an important role in the systemic inflammatory balance by participating in the complex and dynamic network of leukocyte action and pro‐ and anti‐inflammatory cytokines. Loss of this function may result in a propensity to develop systemic inflammatory response syndrome (SIRS), multiorgan dysfunction, and a high risk of death in acute kidney injury (AKI), and may relate to chronic inflammatory state in end‐stage renal disease (ESRD). A renal tubule cell assist device (RAD) containing animal or human renal tubule cells has been recently developed with the purpose of integrating the functions of tubule cells with the filtration function of current dialysis to offer a more complete renal replacement therapy. The viability and functionality of this device were confirmed in in vitro experiments and large animal studies, and recently the RAD’s clinical therapeutic benefit was demonstrated with a series of FDA‐approved human trials. Another novel synthetic membrane extracorporeal device that binds and inhibits circulating leukocytes has been developed with the purpose of reducing microvascular damage promoted primarily via activated circulating leukocytes in AKI and SIRS. This device, called a selective cytopheretic inhibitory device, mimics immunomodulation and duplicates RAD efficiency in preliminary studies. Both devices may become comprehensive treatments, replacing full renal function and correcting inflammatory imbalance in patients with acute and chronic renal disorders.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Inflammation and Insulin Resistance as Novel Mechanisms of Wasting in Chronic Dialysis Patients
Authors: Da Costa José Abrão Cardeal , Alp Ikizler T.
Published: December 2009

Over the last decade, there have been no proven therapies to lower the mortality and morbidity risk for chronic dialysis patients. One of the most important determinants of this poor clinical outcome is protein energy wasting (PEW), a unique and highly prevalent nutritional and metabolic abnormality primarily characterized by increased protein breakdown in the skeletal muscle compartment. Although the etiology and mechanisms leading to increased protein breakdown in chronic dialysis patients are complex and mostly ill‐defined, two well‐recognized and presumably interrelated metabolic abnormalities, insulin resistance and chronic inflammation, are likely to play a critical role in the pathogenesis of this condition. Multiple studies demonstrate the anabolic effects of insulin that extend beyond simple carbohydrate metabolism. Insulin is a mediator of accelerated protein breakdown in the catabolic condition such as advanced kidney disease. Chronic inflammation, a condition known to cause muscle catabolism in experimental conditions, has a strong association with advanced kidney disease in epidemiologic studies. Chronic inflammation is also known to induce insulin resistance, primarily by the induction of proinflammatory cytokines. The protein catabolic effects of inflammation and insulin resistance involve common cellular pathways. Thus, it is reasonable to speculate that chronic inflammation of advanced kidney disease mediates its protein catabolic effects by inducing insulin resistance of protein metabolism at both the physiologic and cellular levels. Modulating inflammatory response or insulin signaling by pharmacologic interventions could allow us to clarify the mechanisms contributing to the development of PEW in the setting of these particular metabolic derangements.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: More of the Same: Improving Outcomes Through Intensive Hemodialysis
Authors: McFarlane Philip A.
Published: December 2009

The typical dialysis patient faces both a poor quality of life and a significantly shortened survival. This is often blamed on “uremia.” However, defining the clinical entity of uremia is surprisingly difficult. It represents the clinical sequelae of the effects of retention products, other effects of renal disease, and the effects of other comorbid conditions. The list of retention products that could act as uremic toxins is lengthy, but it would appear that urea itself does not contribute significantly to the uremic state. Larger molecular weight substances are likely the major contributors to the uremic milieu. Regardless of the causes, the uremic state persists in many patients who are reaching their dialysis adequacy targets as defined by urea clearance. This raises the possibility that more intensive hemodialysis could improve patient outcomes. Hemodialysis can be intensified by increasing dialysis efficiency without changing duration or frequency. Alternatively, hemodialysis duration, frequency, or both can be increased. All intensification methods increase small solute removal, but the removal of larger molecular weight retention products depends more upon treatment time. Modalities such as short daily hemodialysis, long intermittent hemodialysis, and quotidian nocturnal hemodialysis have been associated with a variety of clinical improvements, as well as improvements in quality of life and a lower standardized mortality ratio. However, the HEMO study approach of intensifying small solute clearance without significant modifications of the dialysis schedule does not appear to be effective. Future research will help to define the optimal treatment duration and frequency in hemodialysis patients.
Toward an Ecological CALL: Update to Garrett (1991)
Authors: LAFFORD BARBARA A.
Published: December 2009

This introduction to the 2009 Modern Language Journal Focus Issue uses the lens of an ecological perspective on the acquisition of second languages to provide additional insights into the contributions by various computer‐assisted language learning (CALL) scholars to this update onGarrett (1991), “Technology in the service of language learning: Trends and issues.” After providing a thematic overview of the trends and issues discussed byGarrett(1991, this issue) and the other contributors, I discuss the most salient themes and controversies mentioned by the Focus Issue authors, including CALL and second language acquisition theory, empirical research and CALL, creation and use of CALL materials and technologies, social networking, assessment, the need for teacher training, and professional rewards. This introduction concludes with a section on the future of CALL as an independent field and with a look at future research and practical applications of CALL.
The Relationship Between Second Language Acquisition Theory and Computer‐Assisted Language Learning
Authors: CHAPELLE CAROL A.
Published: December 2009

The point of departure for this article is the contrast between the theoretical landscape within view of language teaching professionals in 1991 and that of today. I argue that the pragmatic goal of computer‐assisted language learning (CALL) developers and researchers to create and evaluate learning opportunities pushes them to consider a variety of theoretical approaches to second language acquisition (SLA), which have developed, in part, in response to the need to theorize the role of instruction in SLA. To illustrate connections between SLA and CALL, I touch on multiple theoretical perspectives grouped into four general approaches: cognitive linguistic (Universal Grammar, autonomous induction theory, and the concept‐oriented approach); psycholinguistic (processibility theory, input processing theory, interactionist theory); human learning (associative–cognitive CREED, skill acquisition theory); and language in social context (sociocultural, language socialization, conversation analysis, systemic–functional, complexity theory). I suggest that such theoretical approaches can be useful in the development and evaluation of CALL materials and tasks. Finally, I propose that the expanding use of technology changes the nature of communicative competence theory, challenges SLA theory, and increases the number of consumers for SLA research.
The Use of Technology for Second Language Distance Learning
Authors: BLAKE ROBERT J.
Published: December 2009

This article describes distance learning (DL) for languages within the context of recent advances and research findings in computer‐assisted language learning (CALL). In addition to reviewing the different DL modalities, theoretical underpinnings, and the most appropriate technological applications to second language learning, the issues of conducting DL research and training faculty to work with this new learning environment will be examined. Garrett's (1991) overview of an earlier state of the CALL field serves as the background for judging how far the field has come, especially with respect to the pedagogical challenges, which have not changed drastically since the 1990s. A key consideration is the notion of interactivity, which is analyzed in depth with relation to both tutorial CALL and social computing.
Mechanical Properties of Nanolaminate Ti3SnC2 Carbide Determined by Nanohardness Cartography
Authors: Tromas Christophe , Ouabadi Nadia , Gauthier‐Brunet Véronique , Jaouen Michel , Dubois Sylvain
Published: December 2009

Nanoindentation is used to measure hardness of Ti3SnC2, a recently synthesized nanolaminate carbide. Hardness cartography and optical microscopy are used to correlate hardness values and sample phases. An indentation size effect is observed, and a bulk hardness of 9.3 GPa is deduced for Ti3SnC2. Such a value is higher than most of hardness values reported for other nanolaminate carbides and nitrides. It is shown that an underestimation of the nanolaminate carbide hardness values likely results from the effect of grain boundaries.
Service Versus Education: Finding the Right Balance: A Consensus Statement from the Council of Emergency Medicine Residency Directors 2009 Academic Assembly “Question 19” Working Group
Authors: Quinn Antonia , Brunett Patrick
Published: December 2009

Many emergency medicine (EM) residency programs have recently received citations for their residents’ responses to Question 19 of the Accreditation Council on Graduate Medical Education annual survey, which asks residents to rate their program’s emphasis on clinical education over service obligations. To the best of our knowledge, no prior investigations or consensus statements exist that specifically address the appropriate balance between educational activity and clinical service in EM residency training. The objective of this project was to create a consensus statement based on the shared insights of academic faculty and educators in EM, with specific recommendations to improve the integration of education with clinical service in EM residency training programs. More than 80 EM program directors (PDs), associate and assistant PDs, and other academic EM faculty attending an annual conference of EM educators met to address this issue in a discussion session and working group. Participants examined the current literature on resident service and education and shared with the conference at large their collective insight and experience and possible solutions to this challenge. A consensus statement of specific recommendations and effective educational techniques aimed at balancing service and education requirements was created, based on the contributions of a diverse group of academic emergency physicians. Recommendations included identifying the teachable moment in all clinical service; promoting resident understanding of program goals and expectations from the beginning; educating residents about the ACGME resident survey; and engaging hospitals, institutional graduate medical education departments, and residents in finding solutions.
The influence of parental behavior on vulnerability to nest predation in tropical thrushes of an Andean cloud forest
Authors: Halupka Konrad , Greeney Harold F.
Published: December 2009

The Skutch hypothesis predicts that parental activity around the nest may attract the attention of predators and thus, in the tropics where predation pressure may be high, selection favors reduced parental activity. This hypothesis has been questioned by studies demonstrating that parents can decrease the risk of nest predation through nest defense. The link between parental activity and predation risk may be further confounded by nest site characteristics. We examined the effects of parental behavior and nest site on clutch survival in two sympatric tropical thrushes (Myadestes ralloides and Turdus leucops). We compared survival rates of clutches in three treatments: 1) natural nests at the incubation stage, 2) unattended nests (un‐manipulated nests of the same species, with clutches unattended by parents), and 3) exposed clutches (eggs exposed in unconcealed positions, unprotected by the nest). Parental activity had a positive effect on clutch survival, which was revealed by significantly higher survival rate of clutches in attended nests compared to unattended nests. The effect of nest site was less clear: clutches in unattended natural nests survived better than clutches in exposed sites selected by humans, but results were insignificant. We propose that parent birds can exclude a group of opportunistic predators, that are able to destroy unattended clutches. Nest site characteristics may be less important in determining clutch survival in the tropics, where predator guilds are more diverse, making completely safe sites difficult to find. Our results challenge Skutch's hypothesis and point to the need for more data from tropical latitudes.
The use of Straumann® Bone Ceramic in a maxillary sinus floor elevation procedure: a clinical, radiological, histological and histomorphometric evaluation with a 6‐month healing period
Authors: Frenken J. W. F. H. , Bouwman W. F. , Bravenboer N. , Zijderveld S. A. , Schulten E. A. J. M. , Ten Bruggenkate C. M.
Published: December 2009

Objectives: In this study, we evaluated the quality and quantity of bone formation in maxillary sinus floor elevation procedure using a new fully synthetic biphasic calcium phosphate (BCP) consisting of a mixture of 60% hydroxyapatite and 40% of β‐tricalcium phosphate (Straumann® Bone Ceramic).

Material and methods: A unilateral maxillary sinus floor elevation procedure was performed in six patients using 100% BCP. Biopsy retrieval for histological and histomorphometric analysis was carried out before implant placement after a 6‐month healing period.

Results: In this study, the maxillary sinus floor elevation procedure with the use of BCP showed uneventful healing. Radiological evaluation after 6 months showed maintenance of vertical height gained immediately after surgery. Primary stability was achieved with all Straumann® SLA dental implants of 4.1 mm diameter and 10 or 12 mm length. The implants appeared to be osseointegrated well after a 3‐month healing period. Histological investigation showed no signs of inflammation. Cranial from the native alveolar bone, newly formed mineralized tissue was observed. Also, osteoid islands as well as connective tissue were seen around the BCP particles, cranial from the front of newly formed mineralized tissue. Close bone‐to‐substitute contact was observed. Histomorphometric analysis showed an average bone volume/total volume (BV/TV) of 27.3% [standard deviation (SD) 4.9], bone surface/total volume (BS/TV) 4.5 mm2/mm3 (SD 1.1), trabecula‐thickness (TbTh) 132.1 μm (SD 38.4), osteoid‐volume/bone volume (OV/BV) 7.5% (SD 4.3), osteoid surface/bone surface (OS/BS) 41.3% (SD 28.5), osteoid thickness (O.Th) 13.3 μm (SD 4.7) and number of osteoclasts/total area (N.Oc/Tar) 4.4 1/mm (SD 5.7).

Conclusions: Although a small number of patients were treated, this study provides radiological and histological evidence in humans confirming the suitability of this new BCP for vertical augmentation of the atrophied maxilla by means of a maxillary sinus floor elevation procedure allowing subsequent dental implant placement after a 6‐month healing period. The newly formed bone had a trabecular structure and was in intimate contact with the substitute material, outlining the osteoconductive properties of the BCP material. Bone maturation was evident by the presence of lamellar bone.

To cite this article:
 Frenken JWFH, Bouwman WF, Bravenboer N, Zijderveld SA, Schulten EAJM, ten Bruggenkate CM. The use of Straumann® Bone Ceramic in a maxillary sinus floor elevation procedure: a clinical, radiological, histological and histomorphometric evaluation with a 6‐month healing period. Clin. Oral Impl. Res. 21, 2010; 201–208. doi: 10.1111/j.1600‐0501.2009.01821.x
The Toxicokinetics and Toxicodynamics of Organophosphonatesversusthe Pharmacokinetics and Pharmacodynamics of Oxime Antidotes: Biological Consequences
Authors: Voicu Victor A. , Thiermann Horst , Rădulescu Flavian Ştefan , Mircioiu Constantin , Miron Dalia Simona
Published: December 2009

Abstract: This paper presents basic data on organophosphonate (OP) mechanisms of action, especially by toxicokinetic/toxicodynamic (TK/TD) process correlations. It is generally accepted that at least during onset of OP biological systems interaction, blood and tissue cholinesterase’s inhibition represents OP exposure marker and initiating mechanisms for toxicodynamic effects, characteristic for cholinergic crisis. OP penetrability of various biological barriers conditioning TK characteristics are determined by a series of physico‐chemical properties. Non‐cholinergic effects, direct interactions with cellular structures and subsequent effects (excitotoxicity) triggered by cholinergic crisis are also briefly presented. Opposed to these OP TK/TD characteristics, the authors analysed the pharmacokinetic/pharmacodynamic (PK/PD) characteristics and their correlations for oximes, as basic OP antidotes, besides atropine and anticonvulsants. Phosphorilated cholinesterasis reactivators are mono or bispyridinium derivatives with quaternary ammonium atoms, high water solubility, ionized at physiological pH, distribution in extra‐cellular space, very low digestive absorption and blood‐brain barrier (BBB) penetrability. OP nerve gas acute toxicity is correlated with anti‐acetylcholinesterase (AChE) activity and partition coefficient. The toxicity rank seems to be determined by lipophilicity, besides their specific AChE inhibitory property. It has the effect that acute toxicity is the resultant of a TD process closely linked and dependentin vivoupon molecular descriptors determinant for the TK process. For cholinesterasis reactivators, molecular and PK characteristics limit their effects, especially to the peripheral level. The absent or much reduced BBB penetrability allowed some researchers to suggest that reactivators’ penetration and presence at central level are not necessary. The study of PK/PD correlations, molecular descriptors and biological membrane permeability of oximes can better define their antidotal effects mechanisms and, maybe, open a new perspective for field development.
The Nordic Countries as a Cohort for Pharmacoepidemiological Research
Authors: Furu Kari , Wettermark Björn , Andersen Morten , Martikainen Jaana E. , Almarsdottir Anna Birna , Sørensen Henrik Toft
Published: December 2009

Abstract:  The Nordic countries have a long tradition of registry‐based epidemiological research. Many population‐based health registries were established in the 1960s, with use of unique personal identifiers facilitating linkage between registries. In recent years, each country has established a national database to track prescription drugs dispensed to individuals in ambulatory care. The objectives were to present an overview of the prescription databases established in the Nordic countries, as well as to elaborate on their unique potential for record linkage and cross‐national comparison of drug utilization. Five Nordic countries collect drug exposure data based on drugs dispensed at pharmacies and have the potential to link these data to health outcomes. The databases together cover 25 million inhabitants (Denmark: 5.5 million; Finland: 5.3 million; Iceland: 0.3 million; Norway: 4.8 million; and Sweden: 9.2 million). In 2007, the registries encompassed 17 million prescription drug users (68% of the total population). We provide examples of how these databases have been used for descriptive drug utilization studies and analytical pharmacoepidemiological studies linking drug exposure to other health registries. Comparisons are facilitated by many similarities among the databases, including data source, content, coverage and methods used for drug utilization studies and record linkage. There are, however, some differences in coding systems and validity, as well as in some access and technical issues. To perform cross‐national pharmacoepidemiological studies, resources, networks and time are needed, as well as methods for pooling data. Interpretation of results needs to account for inter‐country heterogeneity and the possibility of spurious relationships. The Nordic countries have a unique potential for collaborative high‐quality cross‐national pharmacoepidemiological studies with large populations. This research may assist in resolving safety issues of international interest, thus minimizing the risk of either over‐reacting on possible signals or underestimating drug safety issues.
CACHAÇA PRODUCTION IN A LAB‐SCALE ALEMBIC: MODELING AND COMPUTATIONAL SIMULATION
Authors: SCANAVINI HELENA F.A. , CERIANI ROBERTA , CASSINI CARLOS E.B. , SOUZA ELSON L.R. , MAUGERI FILHO FRANCISCO , MEIRELLES ANTONIO J.A.
Published: December 2009

This work presents the application of a differential distillation model for the simulation of cachaça production in a pot still (alembic). The vapor–liquid equilibria of the multicomponent mixture were described in a rigorous way, using the nonrandom two‐liquid model for the liquid phase activity coefficients and the virial equation with the chemical theory for the vapor phase fugacity coefficients. Two experimental trials were performed in order to validate the simulation results. The boiling points of the wine and the ethanol concentration of the distillate were measured at fixed time intervals. The concentrations of acetaldehyde, ethyl acetate, methanol, n‐propanol, isobutanol and isoamyl alcohol, and the volatile acidity were analyzed in the head, heart and tail fractions of the distillate. In general, a good agreement was achieved between the experimental and the simulation results, in terms of the temperature and the alcoholic graduation profiles, and also a satisfactory similitude in terms of the concentrations of the main congeners.

PRACTICAL APPLICATIONS

Spirit's sensorial quality depends on the ethanol and main congener concentrations, which should be controlled by dividing the distillate in appropriate cuts (head, heart and tail fractions) during the distillation. A correct simulation procedure of the pot still distillation allows improving the policy of distillate cuts, considering the product quality, the maximal recovery of ethanol in the heart fraction (spirit) and the energy consumption. It can as well help to define a policy of distillate cuts more appropriate to different types of wine, i.e., wines containing, for instance, larger concentrations of light components (acetaldehyde, methanol, etc.), or of those containing larger contents of heavy compounds, such as acetic acid. So this work goal was to indicate that computational simulation, based on a careful modeling of the system, could be an important tool to investigate the effect of processing variables in the final product quality, also in terms of minor compounds.
TUNING OF A PROPORTIONAL–INTEGRAL–DERIVATIVE CONTROLLER USING A MULTIOBJECTIVE GENETIC ALGORITHM NONDOMINATED SORTING GENETIC ALGORITHM‐II APPLIED TO A pH PROCESS
Authors: MOKEDDEM D. , KHELLAF A.
Published: December 2009

Most control engineering problems are characterized by several, often contradicting, objectives, which have to be satisfied simultaneously. Two widely used methods for finding the optimal solution to such problems are aggregating to a single criterion, and using Pareto‐optimal solutions. Here we propose the nondominated sorting genetic algorithm (NSGA‐II) to find the constant proportional–integral–derivative (PID) control gains for a chemical neutralization plant. Known to be highly nonlinear and with varying time delay, this plant provides a challenging test bed for nonlinear control strategies. The results confirm that a multiobjective, Pareto‐based GA search gives a better performance than a single objective GA. The former method was also used to design a gain‐scheduled PID controller.

PRACTICAL APPLICATIONS

The control of the pH neutralization process plays a very important role in chemical industries, such as wastewater treatments, polymerization reactions, fatty acid production, biochemical processes, pharmaceuticals, biotechnology and so on. The pH neutralization process shows a strong nonlinear behavior and time‐varying nonlinear characteristics resulted from the variation of the feed components or total ion concentrations. In the case of fermentation by the microorganisms, the growth of microorganisms has a pH optimum similar to most biochemical processes. A pH value drifting away from this optimum often inhibits growth of the essential microorganisms, alters the bacterial population and inhibits the desirable enzymatic activities. The result is a delay in the fermentation process, which in turn results in financial loss.
INFLUENCE OF ENZYMOLYSIS‐ADSORPTION INTERACTION ON THE SECONDARY HAZE FORMATION IN APPLE JUICE
Authors: QI JINGHUA , CAI TONGYI , XU YIQING , WU JUN , WANG FANG , PANG MEIXIA , HUANG MANQING
Published: December 2009

The secondary haze formation in clarified apple juice produced under enzymolysis and adsorption processing conditions was studied in order to control the haze formation by monitoring the processing conditions of enzymolysis and adsorption. The turbidity and content of haze‐active protein and content of haze‐active phenolics of the apple juice were monitored at intervals. Haze formation could be prevented if optimum enzymatic time and suitable time of adding activated charcoal are adopted. Enzymatic time contributed to the adsorption and the time of adding activated charcoal during the enzymatic treatment also had effects on the enzymolysis. Varying the time used for enzymolysis of haze had a marked effect on the turbidity and content of haze active protein of apple juice and had no effects on the content of haze‐active polyphenols. Adsorptive treatment given prior to complete enzymolysis did not appear to prevent the haze formation. Adsorptive treatment had more effects on the turbidity and the content of haze active protein and that of haze active polyphenols.

PRACTICAL APPLICATIONS

The processes of enzymolysis and adsorption can be used for the production of clarified apple juice to control the haze formation. The quality of clarified apple juice with enzymatic treatment combining with adsorptive treatment by activated charcoal is much superior to the product using the convectional method. If activated charcoal is added to the enzymatic process at optimum time, the enzymolysis and adsorption can be used successfully for the production of clarified apple juice.