bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of the explant technique on the hemodynamic profile during sequential domino liver transplantation in familial amyloid polyneuropathy patients
Authors: Escobar Bibiana , Taura Pilar , Barreneche Nelson , Beltran Joan , Balust Jaume , Martinez-Palli Graciela , Zavala Elizabeth , Escorsell Angels , Garcia-Valdecasas Juan Carlos
Published: July 2009

Familial amyloidotic polyneuropathy (FAP) patients present adrenergic cardiac input blockade secondary to amyloid deposits and sympathetic neuropathy. Consequently, their capacity to compensate for hemodynamic changes is limited. To avoid hemodynamic disturbances in sequential liver transplants, a standard procedure with venovenous bypass or inferior vena cava preservation is contemplated. The aim of this study was to evaluate the impact of both techniques on the hemodynamic management and outcome of patients affected by FAP and scheduled for a domino liver transplantation program. We evaluated 36 FAP patients. Venovenous bypass was performed for 20 patients (the venovenous bypass group), whereas the vena cava preservation technique was used for the remaining 16 patients (the cava preservation group). The time that elapsed from FAP diagnosis to liver transplantation was 3.2 ± 2.7 years. Peripheral neuropathy was present in all patients, autonomic dysfunction was present in 71%, and cardiac involvement was present in 69%. Renal and gastrointestinal manifestations were reported in 19% and 53% of patients, respectively. The 1-, 3-, and 5-year survival rates were 97%, 93%, and 93%, respectively. Intraoperative hemodynamic and cardiac disorders, need for vasoactive drugs, blood loss, and transfusion requirements were recorded. Postoperative outcome and cardiac and renal complications were also recorded. No significant differences in disease severity or demographic characteristics were observed. Among all the variables studied, only the total ischemia time and time in surgery were significantly longer in the venovenous bypass group patients (P ≤ 0.05). During the postoperative period, the incidence of minor cardiovascular events, incidence of acute renal dysfunction, and outcomes were similar in the 2 groups. In conclusion, either preservation of the vena cava or the standard technique with venovenous bypass can be safely used in FAP patients during liver transplantation. Liver Transpl 15:869–875, 2009. © 2009 AASLD.
Proliferative alloresponse of T-cytotoxic cells identifies rejection-prone children with steroid-free liver transplantation
Authors: Ashokkumar Chethan , Sun Qing , Gupta Ankit , Higgs Brandon W. , Fazzolare Tamara , Remaley Lisa , Mazariegos George , Soltys Kyle , Bond Geoffrey , Sindhi Rakesh
Published: July 2009

Donor-induced and third-party–induced proliferation of T-helper and T-cytotoxic (Tc) cells and their naïve and memory subsets was evaluated simultaneously in single blood samples from 77 children who received steroid-free liver transplantation (LTx) after induction with rabbit anti-human thymocyte globulin. Proliferation was measured by dilution of the intravital dye carboxyfluorescein succinimidyl ester (CFSE) in a 3- to 4-day mixed lymphocyte response coculture. The ratio of donor/third-party–induced proliferated (CFSElow) T-cells was reported as the immunoreactivity index (IR) for each subset. Rejectors were defined as those who experienced biopsy-proven acute cellular rejection within 60 days of the assay. IR > 1 signified increased risk of rejection, and IR < 1 implied decreased risk. Demographics for 32 rejectors and 45 nonrejectors were similar. Proliferated CFSElow T-cells and subsets were significantly higher among rejectors compared with nonrejectors. In 33 of 77 randomly selected children, logistic regression, leave-one-out cross-validation, and receiver operating characteristic analyses showed that the IR of Tc cells was best associated with biopsy-proven rejection (sensitivity > 75%, specificity > 88%). Sensitivity and specificity were replicated in the remaining 44 children who composed the validation cohort. IR of CFSElow Tc cells correlated significantly with IR of proinflammatory, allospecific CD154+ Tc cells (r = 0.664, P = 0.0005) and inversely with IR of allospecific, anti-inflammatory, cytotoxic T lymphocyte antigen 4–positive Tc cells (r = −0.630, P = 0.007). In conclusion, proliferative alloresponses of Tc cells can identify rejection-prone children receiving LTx. Liver Transpl 15:978–985, 2009. © 2009 AASLD.
Incidence, risk factors, and outcome of chronic rejection during antiviral therapy for posttransplant recurrent hepatitis C
Authors: Fernández Inmaculada , Ulloa Esperanza , Colina Francisco , Abradelo Manuel , Jiménez Carlos , Gimeno Alberto , Meneu Juan Carlos , Lumbreras Carlos , Solís-Herruzo José Antonio , Moreno Enrique
Published: July 2009

Antiviral therapy for recurrent hepatitis C in liver transplantation has been associated with the development of chronic rejection. The aim of this study was to assess the incidence, evolution, and risk factors associated with the development of chronic rejection during posttransplant hepatitis C virus antiviral therapy. Seventy-nine patients with posttransplant recurrent hepatitis C who were treated with pegylated interferon and ribavirin were prospectively followed. Liver biopsy was performed before antiviral therapy was initiated and when liver tests worsened during therapy. Pretransplant and posttransplant factors were analyzed as potential risk factors for the development of chronic rejection. Seven of 79 patients (9%) developed chronic rejection during antiviral therapy. The mean time from the start of treatment to the development of chronic rejection was 5.8 months (3–12 months). An analysis of factors associated with the development of chronic rejection showed that the use of cyclosporine as immunosuppression therapy (6 of 19 patients who received cyclosporine developed chronic rejection in comparison with only 1 of 57 patients who received tacrolimus; P = 0.0013), achievement of sustained virological response (P = 0.043), and ribavirin discontinuation (P = 0.027) were associated with the development of chronic rejection. In conclusion, the development of chronic rejection during posttransplant pegylated interferon and ribavirin therapy is a severe complication. The use of cyclosporine, ribavirin discontinuation, and viral infection elimination seem to be associated with the development of this complication. Liver Transpl 15:948–955, 2009. © 2009 AASLD.
Does “Surgical Hepatitis” Lead to Poor Graft Function?
Authors: Perkins James D.
Published: July 2009

Abstract

Background:

Experimental models of hepatic ischemia/reperfusion injury have implicated a pathophysiologic role for neutrophils in subsequent hepatocellular damage. In human liver transplantation, however, the effect of reperfusion-induced neutrophil activation on initial graft function is not clear.

Methods:

In 38 patients undergoing liver transplantation, neutrophil CD11b and L-selectin expression, neutrophil count, and plasma lactoferrin levels were measured. To assess changes within the graft during initial reperfusion, samples of blood entering and leaving the graft were obtained simultaneously, and transhepatic ratio calculated (hepatic vein/portal vein; 1 denotes no change, <1 a decrease, and >1 an increase across the liver). Graft steatosis, postoperative liver function, and outcome were recorded. Associations between neutrophil activation markers and outcome measures were evaluated.

Results:

Substantial hepatic neutrophil activation occurred during initial reperfusion, demonstrated by concomitant L-selectin shedding and CD11b upregulation (transhepatic ratios 0.9 [0.7–1.0]; 1.4 [0.9–1.9]; both P <.001; portal vs hepatic vein]. Simultaneously, hepatic neutrophil sequestration and lactoferrin release occurred (0.3 [0.2–0.5]; 1.7 [1.3–3.4]; both P <.001). Neither cold ischemic time (CIT; median 5 hours 36 minutes) nor hepatic neutrophil activation during reperfusion predicted early graft function, nor was there any association between CIT and neutrophil activation.

Conclusions:

Despite short CIT, extensive graft neutrophil activation and sequestration occurred. This, however, was not associated with impaired early graft function, suggesting short CIT may protect against severe neutrophil-mediated injury.
Antifungal prophylaxis in liver transplant recipients
Authors: Eschenauer Gregory A. , Lam Simon W. , Carver Peggy L.
Published: July 2009

Although the overall incidence of fungal infections in liver transplant recipients has declined, these infections still contribute significantly to the morbidity and mortality of patients with risk factors for infection. Although antifungal prophylaxis has been widely studied and practiced, no consensus exists on which patients should receive prophylaxis, with which agent, and for what duration. Numerous studies have attempted to ascertain independent risk factors for invasive fungal infections in liver transplant patients, and these data, in addition to clinical trials, identify several patient groups at exceedingly high risk of fungal infection. These include retransplant patients, patients with renal failure requiring hemodialysis or renal replacement therapy, and those requiring reoperations after transplant. Because the majority of infections occur in the first month after transplantation, prophylaxis should be continued for 4-6 weeks. However, local epidemiology and research should guide decisions regarding choice of agent as well as overall development of interinstitutional guidelines, because the incidence and spectrum of infection may differ dramatically among institutions. Liver Transpl 15:842–858, 2009. © 2009 AASLD.
Micropatterned Fiber Scaffolds for Spatially Controlled Cell Adhesion
Authors: Mandal Suparna , Bhaskar Srijanani , Lahann Joerg
Published: July 2009

Because the local microstructure plays a pivotal role for many biological functions, a wide range of methods have been developed to design precisely engineered substrates for both fundamental biological studies and biotechnological applications. However, these techniques have been by‐and‐large limited to flat surfaces. Herein, we use electrohydrodynamic co‐spinning to prepare biodegradable three‐dimensional fiber scaffolds with precisely engineered, micrometre‐scale patterns, wherein each fiber is comprised of two distinguishable compartments. When bicompartmental fiber scaffolds are modified via spatially controlled peptide immobilization, highly selective cell guidance at spatial resolutions (<10 µm), so far exclusively reserved for flat substrates, is achieved. Microstructured fiber scaffolds may have utility for a range of biotechnological applications including tissue engineering or cell‐based assays.

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Prevalence of risk factors for statin‐induced myopathy in rheumatoid arthritis patients
Authors: Toms Tracey E. , Smith Jacqueline P. , Panoulas Vasileios F. , Douglas Karen M.J. , Saratzis Athanasios N. , Kitas George D.
Published: July 2009

Objectives: Statins are widely prescribed in patients with rheumatoid arthritis (RA). Although statins offer overwhelming cardiovascular benefits, their use can be associated with the development of a statin‐induced myopathy. Several factors increase the risk of developing statin‐induced myopathy, including the single nucleotide polymorphism (SNP) rs4149056, located within the gene encoding solute carrier organic anion transporter (SLCO1B1). We aimed to identify the frequency of risk factors for statin‐induced myopathy and establish whether the rs4149056 genotype is more prevalent in RA.

Methods: A total of 396 RA patients and 438 non‐RA controls were studied. DNA samples were obtained from all patients. The SNP rs4149056 was identified using real‐time polymerase chain reaction and melting curve analysis. Genotypic and allelic frequencies were calculated using the chi‐squared test.

Results: Almost 80% of RA patients had one or more risk factor (range 1–5) for the development of statin‐induced myopathy. Of the 74 RA patients treated with statins, 90% had one or more (range 1–4) risk factors. No differences in genotype or allelic frequencies were observed between RA patients and controls.

Conclusions: RA patients harbour multiple risk factors for statin‐induced myopathy. However, the frequency of the rs4149056 genotypes does not differ according to the presence of RA. Despite this, no cases of statin‐induced myopathy were observed in this cohort over a period of four years of follow‐up. Thus, we conclude that statin use among RA patients is probably safe, but large‐scale prospective studies are needed to confirm this. In the meantime, it may be good practice systematically to consider and record myopathy risk factors in these patients. Copyright © 2009 John Wiley & Sons, Ltd
Mission‐Based Budgeting for Education: Ready for Prime Time?
Authors: Sainté Michelle , Kanter Steven L. , Muller David
Published: July 2009

Mission‐based budgeting has been touted as the preferred method of assessing and assigning departmental budgets in academic medical centers. Mission‐based budgeting in its simplest form is a methodology that allows an institution's finance department to align costs with actual activities (typically clinical care, administration, research, and teaching). Despite its intuitive appeal, a minority of the academic medical centers across the country have embraced it. Mount Sinai School of Medicine was among the first to incorporate this approach, and we have almost a decade of experience with its risks and benefits. This article focuses on the education component of mission‐based budgeting. We review all aspects of mission‐based budgeting, including (1) the many variables that must be factored into a metric and how those variables differ among institutions, (2) the metric itself and how it reflects institutional philosophy, (3) the impact of mission‐based budgeting on faculty and chairs of departments, (4) existing processes that ensure the quality, reliability, and validity of the different mission‐based budgeting systems, and (5) a comparative perspective. Mt Sinai J Med 76:381–386, 2009. © 2008 Mount Sinai School of Medicine
Student‐Run Health Clinic: Novel Arena to Educate Medical Students on Systems‐Based Practice
Authors: Meah Yasmin S. , Smith Eric L. , Thomas David C.
Published: July 2009

In recent decades, the United States has experienced substantial growth in the number of student‐run clinics for the indigent. Today, over 49 medical schools across the country operate over 110 student‐run outreach clinics that provide primary care services to the poor and uninsured. Despite this development, little research has been published on the educational value of such student‐led endeavors. Although much has been surmised, no general methodology for categorizing the learning experience in these clinics has been established. This article represents the first literature review of the novel method of educating students through the operation of a clinic for the underserved. It highlights the student‐run clinic as a unique enhancement of medical education that may supplant current curricular arenas in teaching students about systems‐based practice principles such as cost containment and financing, resource allocation, interdisciplinary collaboration, patient advocacy, and monitoring and delivery of quality care. The novelty of the student‐run clinic is that students place themselves at the forefront of problem solving and system navigation to effectively care for severely disadvantaged populations. This article underscores the student‐run clinic as a potentially ideal experiential learning method for preparing young physicians to confront a US healthcare system currently facing crises in cost, quality of care, and high rates of uninsurance. The article stresses the need for outcomes research on the long‐term effectiveness of the student‐run clinic experience in affecting medical student practice behaviors and attitudes in patient care settings that extend beyond the student‐run clinic. Mt Sinai J Med 76:344–356, 2009. © 2008 Mount Sinai School of Medicine
Medical Student Documentation in the Medical Record: Is It a Liability?
Authors: Gliatto Peter , Masters Philip , Karani Reena
Published: July 2009

Medical students have routinely documented patient encounters in both inpatient and outpatient care venues. This hands‐on experience has provided a way for students to reflect on patient encounters, learn proper documentation skills, and attain a sense of being actively involved in and responsible for the care of patients. Over the last several years, the practice of student note writing has come into question. Institutional disincentives to student documentation include insurance regulations that restrict student documentation from substantiating billing claims, concerns about the legal status of student notes, and implementation of electronic medical records that do not allow or restrict student access. The increased scrutiny of the medical record from pay‐for‐performance programs and other quality measures will likely add to the pressure to exclude students from writing notes. This trend in limiting medical student documentation may have wide‐ranging consequences for student education, from delaying the learning of proper documentation skills to limiting training opportunities. This article reviews the educational value of student note writing, the factors that have made student documentation problematic, and the potential educational impact of limiting student documentation. In addition, it offers some suggestions for future research to guide policy in this area. Mt Sinai J Med 76:357–364, 2009. © 2008 Mount Sinai School of Medicine
Pure equilibrium tetrahedral finite elements for global error estimation by dual analysis
Authors: Kempeneers Martin , Debongnie Jean‐François , Beckers Pierre
Published: July 2009

This study presents a general procedure of creating pure equilibrium tetrahedral finite elements for use under the elastostatic hypothesis. These pure equilibrium elements are of the Fraeijs de Veubeke type and the degree of the polynomial approximation functions of their internal stress field is the parameter generating this new elements family. The spurious kinematic modes (SKM), inherent in the equilibrium approach, are eliminated at the element level by converting each tetrahedron into a super‐element defined as an assembly of four tetrahedral primitive elements. A mathematical discussion on the number of SKM of the primitive elements as well as their elimination by the super‐element technique has been carried out. The development of first and second degree elements is presented here in detail and their efficiency in the frame of global error estimation by dual analysis is emphasized by two numerical applications. The main attribute of the error estimation by dual analysis is that it provides an upper bound on the global discretization error. Copyright © 2009 John Wiley & Sons, Ltd.
A meta‐analytic review of obesity prevention in the schools: 1997–2008
Authors: Cook‐Cottone Catherine , Casey Carolyn M. , Feeley Thomas Hugh , Baran Jennifer
Published: July 2009

A meta‐analysis was conducted on school‐based interventions to reduce obesity in children. Sixty‐six (k = 66, N = 31,059) comparisons from 40 published studies from 1997 through 2008 were included in analyses. Results indicated a significant effect for school‐based interventions with an overall weighted effect size of r = .05. Several moderating factors were examined to explain the heterogeneity in study outcomes. Interventions that were universal (k = 37, r = .07), conducted in elementary schools (k = 41, r = .06), implemented collaboratively (k = 19, r = .12), primarily included children of Asian ethnicity (k = 5, r = .30), encouraged nutritional change (k = 28, r = .13), and sought to reduce sedentary behaviors (k = 17, r = .15) were identified as more successful in reducing students' obesity‐related outcomes. Factors that resulted in negative effects for school‐based programs included interventions of short duration (k = 11, r = −.04) and those that implemented system‐wide changes in nutrition (k = 15, r = −.03). The variability in study effect sizes is discussed, and recommendations are made for future school‐based interventions targeting children. © 2009 Wiley Periodicals, Inc.
Exercise‐based school obesity prevention programs: An overview
Authors: Yetter Georgette
Published: July 2009

Overweight and obesity are major health concerns for young people. Schools are particularly promising environments for preventing and treating obesity. The Institutes of Medicine recommends 60 minutes per day of physical activity for children and youth, including at least 30 minutes at school. Yet the amount of moderate to vigorous physical exercise children and youth receive at school falls far short of these recommendations. Several intervention programs are supported by well‐controlled studies. These effective programs include Planet Health, the Stanford Adolescent Heart Health Program, Dance for Health, Cardiovascular Health in Children, and the Middle School Physical Activity and Nutrition. Unfortunately, the many methodological shortcomings and inconsistencies in the obesity prevention literature make it difficult to draw clear conclusions about effective program components. Specific resources and recommendations are included to guide school psychologists in improving their schools' climate for health. © 2009 Wiley Periodicals, Inc.
Glycosylation status of vitamin D binding protein in cancer patients
Authors: Rehder Douglas S. , Nelson Randall W. , Borges Chad R.
Published: July 2009

On the basis of the results of activity studies, previous reports have suggested that vitamin D binding protein (DBP) is significantly or even completely deglycosylated in cancer patients, eliminating the molecular precursor of the immunologically important Gc macrophage activating factor (GcMAF), a glycosidase‐derived product of DBP. The purpose of this investigation was to directly determine the relative degree of O‐linked trisaccharide glycosylation of serum‐derived DBP in human breast, colorectal, pancreatic, and prostate cancer patients. Results obtained by electrospray ionization‐based mass spectrometric immunoassay showed that there was no significant depletion of DBP trisaccharide glycosylation in the 56 cancer patients examined relative to healthy controls. These results suggest that alternative hypotheses regarding the molecular and/or structural origins of GcMAF must be considered to explain the relative inability of cancer patient serum to activate macrophages.
Responses of the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham) (Coleoptera: Curculionidae), to seed treatments of canola (Brassica napus L.) with the neonicotinoid compounds clothianidin and imidacloprid
Authors: Dosdall Lloyd M
Published: July 2009

BACKGROUND: The cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), is a major pest in the production of canola (Brassica napus L.) in North America and Europe, and effective population control is often essential for economical crop production. In North America, neonicotinoid insecticides have been used for several years in canola as seed treatments for reducing herbivory by flea beetles. The neonicotinoids clothianidin and imidacloprid were investigated to determine their effects on preimaginal development and on emergence of new‐generation adults of C. obstrictus in comparison with effects of lindane, a chlorinated hydrocarbon seed treatment.

RESULTS: Mean numbers of second‐ and third‐instar larvae were significantly higher in plants seed‐treated with lindane than in plants treated with the neonicotinoid compounds, even though weevil oviposition was similar for all treatments. Emergence of new‐generation adults was reduced by 52 and 39% for plants seed‐treated with clothianidin and imidacloprid, respectively, compared with emergence from plants treated with lindane.

CONCLUSION: Seed treatment with both clothianidin and imidacloprid produced systemic insecticidal effects on larvae of C. obstrictus, with clothianidin slightly more effective than imidacloprid. Use of clothianidin or imidacloprid as seed treatments can comprise an important component in the integrated management of cabbage seedpod weevil in canola. Copyright © 2009 Society of Chemical Industry
Synergistic antioxidative activities of hydroxycinnamoyl‐peptides
Authors: Kwak Seon‐Yeong , Seo Hyo‐Suk , Lee Yoon‐Sik
Published: July 2009

Antioxidants have become an important subject of study as an active ingredient for cosmetics and preservatives for food. We synthesized antioxidative peptide conjugates of hydroxycinnamic acids (HCAs) such as ferulic acid (FA), caffeic acid (CA), and sinapic acid (SA) by SPPS method. We measured their potential antioxidant properties by 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH) scavenging test and lipid autoxidation inhibition test. When the antioxidative peptides, such as glutathione analogue (GS(Bzl)H) and carnosine (CAR), were conjugated to HCAs, their antioxidative activities were enhanced significantly. CA‐peptides exhibited the highest free radical scavenging activity by the DPPH test, and showed good antioxidative activity in the lipid autoxidation test. FA‐ and SA‐peptides showed excellent antioxidative activity in the lipid autoxidation test. Furthermore, we demonstrated a synergistic antioxidative activity of HCA‐peptide conjugates by comparing their antioxidative activity with that of a simple mixture of HCAs and the antioxidant peptides. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Tin monoxide as an s‐orbital‐based p‐type oxide semiconductor: Electronic structures and TFT application
Authors: Ogo Yoichi , Hiramatsu Hidenori , Nomura Kenji , Yanagi Hiroshi , Kamiya Toshio , Kimura Mutsumi , Hirano Masahiro , Hosono Hideo
Published: July 2009

Tin monoxide (SnO) is a stable p‐type oxide semiconductor. This paper reports electrical properties, electronic structures, and thin‐film transistors (TFTs) of SnO. Epitaxial films were fabricated by pulsed laser deposition. The Hall mobility and the hole density of the epitaxial films were 2.4 cm2 V−1 s−1 and 2.5 × 1017, respectively. X‐ray photoelectron spectroscopy (PES) indicated that the closed‐shell 5s2 orbitals of Sn2+ ions heavily contribute to the hole conduction path in SnO. Top gate type TFTs (W/L = 300/50 µm) employing 20 nm thick SnO channels exhibited field‐effect mobilities µsat = 0.7 cm2 V−1 s−1 and µlin = 1.3 cm2 V−1 s−1, which are larger by two orders of magnitude than those reported for p‐channel oxide TFTs to date. On/off current ratios were ∼102 and subthreshold voltage swings (S) ∼7 V/decade. The parameters required for TFT simulations were estimated by ultraviolet PES and first‐principles calculations. The TFT simulations indicated that subgap hole trap density in the SnO channel is >1019 cm−3, which limits the TFT mobilities and the S values.
Synthesis and characterization of host–guest materials obtained by inserting coumarin into hydrotalcite layers for LED applications
Authors: Kumar Sumeet , Milanesio Marco , Marchese Leonardo , Boccaleri Enrico
Published: July 2009

The possible interactions between luminescent moieties with hydrotalcite (HTLC) host have been investigated. We present the work done in synthesizing luminescent materials containing coumarin‐3‐carboxylic acid (3CCA). A hydrothermal synthesis is carried out to intercalate the 3CCA into the HTLC with empirical formula: [M(II)0.65M(III)0.35 (OH)2](X)0.35 · nH20], where MII = (Zn2+), MIII = Al3+, X = 3CCA− or NO. The ZnAl HTLC materials with [M(II)/M(III) ≈ 2.0] thus synthesized were characterized by XRPD/FTIR/ICP‐MS/TGA/SEM techniques and solid‐state luminescent measurements. The thermal stability and the luminescent properties of obtained hybrid materials are promising because of the observed photoluminescence in the visible region and their high‐temperature resistance indicated by the in situ XRPD measurements and TGA/DTG analysis.
Indium molybdenum oxide thin films: A comparative study by two different RF sputtering systems
Authors: Elangovan E. , Martins R. , Fortunato E.
Published: July 2009

Indium molybdenum oxide thin films were deposited using different radio‐frequency sputtering units on glass substrates at room temperature from an In2O3 (95 wt.%): Mo (5 wt.%) target. The film thickness ranges between 160 and 275 nm. The chamber volume of Unit‐1 was ∼2.4 times larger than that of Unit‐2. Apart from the chamber volume, a significant difference between the two units was the sputtering pressure. The films were characterized by their structural, morphological, optical, and electrical properties. A strong reflection from (222) plane was obtained for the ∼275 nm thick films deposited in Unit‐1. The films deposited with <275 nm thickness and those deposited in Unit‐2 are close to amorphous with a small crystalline fraction. The surface of the films deposited in Unit‐1 is comprised of randomly arranged crystallites, which is restructured with the increasing film thickness to become a well defined “rice field” like structure (275 nm thick). The films deposited in Unit‐2 are comprised of many holes on the surface that is presumably due to back sputtering. The average visible transmittance calculated in the wavelength between 400 and 800 nm ranges from 70 to 82%. The optical band gap is found to vary between 3.80 and 3.86 eV. The lowest bulk resistivity of the films deposited in Unit‐1 was increased from ∼4.06 × 10−3 to 4.07 × 10−1 Ω cm when deposited in Unit‐2. The carrier concentration was decreased from 1.31 × 1020 to 1.03 × 1018 cm−3 but the Hall mobility increased from 11.7 to 15.0 cm2   V−1   s−1.
Identifying the time of polynomial drift in the mean of autocorrelated processes
Authors: Perry Marcus B.
Published: July 2009

Control charts are used to detect changes in a process. Once a change is detected, knowledge of the change point would simplify the search for and identification of the special ause. Consequently, having an estimate of the process change point following a control chart signal would be useful to process engineers. This paper addresses change point estimation for covariance‐stationary autocorrelated processes where the mean drifts deterministically with time. For example, the mean of a chemical process might drift linearly over time as a result of a constant pressure leak. The goal of this paper is to derive and evaluate an MLE for the time of polynomial drift in the mean of autocorrelated processes. It is assumed that the behavior in the process mean over time is adequately modeled by thekth‐order polynomial trend model. Further, it is assumed that the autocorrelation structure is adequately modeled by the general (stationary and invertible) mixed autoregressive‐moving‐average model. The estimator is intended to be applied to data obtained following a genuine control chart signal in efforts to help pinpoint the root cause of process change. Application of the estimator is demonstrated using a simulated data set. The performance of the estimator is evaluated through Monte Carlo simulation studies for thek=1 case and across several processes yielding various levels of positive autocorrelation. Results suggest that the proposed estimator provides process engineers with an accurate and useful estimate for the last sample obtained from the unchanged process. Copyright © 2009 John Wiley & Sons, Ltd.
Optimal maintenance strategy for Technology‐enhanced classrooms: a case study
Authors: Lawson John S. , Manortey Stephen
Published: July 2009

The purpose of the study was to collect data and evaluate an age‐based bulb replacement policy for projectors used in Technology‐enhanced classrooms in a university campus.The Office of Information Technology (OIT) had instituted a policy to replace bulbs in these projectors after either failure or 1800h of operation without failure. However, databases maintained by OIT included the time to bulb failure, the average number of times the bulbs were turned on and off per week, and the number of thermal events. Modeling the failure data with a Weibull proportional hazards model revealed that probability of bulb failure was a function of the number of hours a bulb was used and the frequency at which it was turned on and off. Combining this information with a cost model led to the recommendation for an improved condition‐based replacement policy. Copyright © 2009 John Wiley & Sons, Ltd.
Planck–Benzinger thermal work function: Monoclonal antibody–DNA duplex binding interactions
Authors: Chun Paul W.
Published: July 2009

We have reexamined the van't Hoff plots and delineation of thermodynamic data of the monoclonal antibodies of Jel 274 and Jel 241 binding to DNA duplex at high ionic strength using fluorescein‐labeled oligonucleotide titration with increasing concentrations of the antibody as reported by Tanha and Lee (Nucleic Acid Res, 1997, 25, 1442). To compare the thermodynamic parameters from data over the experimental temperature range of 277–312.5 K, the binding constant from van't Hoff plots is used to evaluate ΔGo(T) from 0 to 400 K using our general linear T3 model, ΔGo(T) = α +βT2+γT3. The limited information provided by the van't Hoff plots and their extensions is not sufficient to describe the variations in the Gibbs free energy change as a function of temperature and other thermodynamic functions observed in these and other biological interactions. Rather, it is necessary to determine a number of thermodynamic parameters, including the heat of reaction, (Th), (Tm), and (TCp), and the thermal set point, (TS), all of which can be precisely assessed using our general linear T3 model. To date, no experimental measurement offers this degree of accuracy. In evaluating the thermodynamic parameters in the binding interaction of monoclonal IgG Jel 241–d[AT]20DNA duplex, it is apparent that at a high NaCl concentration, the range of the compensatory temperatures, (Th) = 155 K and (Tm) = 450 K, is much broader than observed in any other sample, whereas the thermal set points, (TS) = 330 K, is 20–30 K higher. The inherent chemical bond energy ΔHo(T0) is much lower in this sample. The values of thermal agitation energy (heat capacity integrals) are of similar magnitude for all the samples tested. It appears that increasing the NaCl concentration to 130 mM will greatly enhance the binding interaction between the monoclonal antibody and DNA duplex. It is not clear, however, from the limited data available, whether the binding interaction is sequence specific, although logic would suggest it is. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
A DFT study of two diiron (II) synthetic model compounds and their diiron(III) peroxide oxygenation products
Authors: Binning R. C. , Bacelo Daniel E.
Published: July 2009

Unrestricted density functional theory calculations have been conducted on two diiron(II) synthetic model compounds. Calculations employed the BPW91 and BOP density functionals with both high‐spin and broken symmetry low‐spin representations of weakly coupled high‐spin irons. Comparison of the calculated and crystallographic structures is made, and good agreement is found with both spin representations. Raman spectral data are available for the diiron(III) product of the reaction with O2 to form a bridged peroxide. Calculated harmonic frequencies confirm the experimental assignments. Small geometry differences between the high spin and broken symmetry results are seen in bond lengths, angles, Raman frequencies, and spin densities associated with oxo and peroxo bridges in the diiron(III) oxidation products. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Pt adsorption on the PbTiO3(110) polar surface: a density functional theory study
Authors: Pang Qing , Zhang Jian‐Min , Xu Ke‐Wei , Ji Vincent
Published: July 2009

The monolayer (ML) and submonolayer Pt on both terminations of PbTiO3(110) polar surface have been studied by using density functional theory (DFT) with projector‐augmented wave(PAW) potential and a supercell approach. The most favored ML Pt arrangements on PbTiO and O2terminations are the hollow site and the short‐bridge site, respectively. By examining the geometries of different ML arrangements, we know that the dominant impetus for stability of the favored adsorption site for PbTiO termination is the Pt–Ti interaction (mainly from covalent bonding), while that for O2termination is the Pt–O interaction (mainly from ionic bonding). In addition, the appearance of the gap electronic states in the outermost layers of each termination indicates that a channel for charge transfer between adsorbed layer and substrate is formed. Moreover, the interface hybridization between Pt 5d and O 2p orbitals is also observed, especially for ML Pt on O2termination. The stability sequences for various arrangements of 1/2 ML Pt adsorption conform well with those of ML Pt adsorption, and the most stable arrangement is energetically more favorable than the corresponding ML coverage in the view of adsorption energy maximization. The behavior, i.e. the increase in adsorption energy with decrease in coverage, indicates that PtPt interactions weaken those between Pt and the substrate. Copyright © 2009 John Wiley & Sons, Ltd.
Gold Nanoparticles of Diameter 1.4 nm Trigger Necrosis by Oxidative Stress and Mitochondrial Damage
Authors: Pan Yu , Leifert Annika , Ruau David , Neuss Sabine , Bornemann Jörg , Schmid Günter , Brandau Wolfgang , Simon Ulrich , Jahnen‐Dechent Willi
Published: July 2009

Gold nanoparticles (AuNPs) are generally considered nontoxic, similar to bulk gold, which is inert and biocompatible. AuNPs of diameter 1.4 nm capped with triphenylphosphine monosulfonate (TPPMS), Au1.4MS, are much more cytotoxic than 15‐nm nanoparticles (Au15MS) of similar chemical composition. Here, major cell‐death pathways are studied and it is determined that the cytotoxicity is caused by oxidative stress. Indicators of oxidative stress, reactive oxygen species (ROS), mitochondrial potential and integrity, and mitochondrial substrate reduction are all compromised. Genome‐wide expression profiling using DNA gene arrays indicates robust upregulation of stress‐related genes after 6 and 12 h of incubation with a 2 × IC50 concentration of Au1.4MS but not with Au15MS nanoparticles. The caspase inhibitor Z‐VAD‐fmk does not rescue the cells, which suggests that necrosis, not apoptosis, is the predominant pathway at this concentration. Pretreatment of the nanoparticles with reducing agents/antioxidants N‐acetylcysteine, glutathione, and TPPMS reduces the toxicity of Au1.4MS. AuNPs of similar size but capped with glutathione (Au1.1GSH) likewise do not induce oxidative stress. Besides the size dependency of AuNP toxicity, ligand chemistry is a critical parameter determining the degree of cytotoxicity. AuNP exposure most likely causes oxidative stress that is amplified by mitochondrial damage. Au1.4MS nanoparticle cytotoxicity is associated with oxidative stress, endogenous ROS production, and depletion of the intracellular antioxidant pool.
Wrapping Nanotubes with Micelles, Hemimicelles, and Cylindrical Micelles
Authors: Calvaresi Matteo , Dallavalle Marco , Zerbetto Francesco
Published: July 2009

This work uses a simple model based on hydrophobic and hydrophilic forces to investigate the molecular dynamics that lead to the supramolecular self‐assembly of surfactants around carbon nanotubes (CNTs). The effects of the concentration and the structure of surfactants are explored. The bead‐based mesoscopic description spontaneously develops the several micellar morphologies that are known to wrap and solvate CNTs.
Bimetallic Nanostructures as Active Raman Markers: Gold‐Nanoparticle Assembly on 1D and 2D Silver Nanostructure Surfaces
Authors: Gunawidjaja Ray , Kharlampieva Eugenia , Choi Ikjun , Tsukruk Vladimir V.
Published: July 2009

It is demonstrated that bimetallic silver–gold anisotropic nanostructures can be easily assembled from various nanoparticle building blocks with well‐defined geometries by means of electrostatic interactions. One‐dimensional (1D) silver nanowires, two‐dimensional (2D) silver nanoplates, and spherical gold nanoparticles are used as representative building blocks for bottom‐up assembly. The gold nanoparticles are electrostatically bound onto the 1D silver nanowires and the 2D silver nanoplates to give bimetallic nanostructures. The unique feature of the resulting nanostructures is the particle‐to‐particle interaction that subjects absorbed analytes to an enhanced electromagnetic field with strong polarization dependence. The Raman activity of the bimetallic nanostructures is compared with that of the individual nanoparticle blocks by using rhodamine 6G solution as the model analyte. The Raman intensity of the best‐performing silver–gold nanostructure is comparable with the dense array of silver nanowires and silver nanoplates that were prepared by means of the Langmuir–Blodgett technique. An optimized design of a single‐nanostructure substrate for surface‐enhanced Raman spectroscopy (SERS), based on a wet‐assembly technique proposed here, can serve as a compact and low‐cost alternative to fabricated nanoparticle arrays.
Formation of Single Tiers of Bridging Silicon Nanowires for Transistor Applications Using Vapor–Liquid–Solid Growth from Short Silicon‐on‐Insulator Sidewalls
Authors: Nayfeh Osama M. , Antoniadis Dimitri A. , Boles Steven , Ho Charles , Thompson Carl V.
Published: July 2009

Single tiers of silicon nanowires that bridge the gap between the short sidewalls of silicon‐on‐insulator (SOI) source/drain pads are formed. The formation of a single tier of bridging nanowires is enabled by the attachment of a single tier of Au catalyst nanoparticles to short SOI sidewalls and the subsequent growth of epitaxial nanowires via the vapor–liquid–solid (VLS) process. The growth of unobstructed nanowire material occurs due to the attachment of catalyst nanoparticles on silicon surfaces and the removal of catalyst nanoparticles from the SOI‐buried oxide (BOX). Three‐terminal current–voltage measurements of the structure using the substrate as a planar backgate after VLS nanowire growth reveal transistor behaviour characteristics.
GABAA‐benzodiazepine receptor availability in smokers and nonsmokers: Relationship to subsyndromal anxiety and depression
Authors: Esterlis Irina , Cosgrove Kelly P. , Batis Jeffery C. , Bois Frederic , Kloczynski Tracy A. , Stiklus Stephanie M. , Perry Edward , Tamagnan Gilles D. , Seibyl John P. , Makuch Robert , Krishnan‐Sarin Suchitra , O'Malley Stephanie , Staley Julie K.
Published: July 2009

Many smokers experience subsyndromal anxiety symptoms while smoking and during acute abstinence, which may contribute to relapse. We hypothesized that cortical gamma aminobutyric acidA‐benzodiazepine receptor (GABAA‐BZR) availability in smokers and nonsmokers might be related to the expression of subsyndromal anxiety, depressive, and pain symptoms. Cortical GABAA‐BZRs were imaged in 15 smokers (8 men and 7 women), and 15 healthy age and sex‐matched nonsmokers, and 4 abstinent tobacco smokers (3 men; 1 woman) using [123I]iomazenil and single photon emission computed tomography (SPECT). Anxiety and depressive symptoms were measured using the Spielberger's State‐Trait Anxiety Index (STAI) and the Center for Epidemiology Scale for Depressive Symptoms (CES‐D). The cold pressor task was administered to assess pain tolerance and sensitivity. The relationship between cortical GABAA‐BZR availability, smoking status, and subsyndromal depression and anxiety symptoms, as well as pain tolerance and sensitivity, were evaluated. Surprisingly, there were no statistically significant differences in overall GABAA‐BZR availability between smokers and nonsmokers or between active and abstinent smokers; however, cortical GABAA‐BZR availability negatively correlated with subsyndromal state anxiety symptoms in nonsmokers but not in smokers. In nonsmokers, the correlation was seen across many brain areas with state anxiety [parietal (r= −0.47,P= 0.03), frontal (r= −0.46,P= 0.03), anterior cingulate (r= −0.47,P= 0.04), temporal (r= −0.47,P= 0.03), occipital (r= −0.43,P= 0.05) cortices, and cerebellum (r= −0.46,P= 0.04)], trait anxiety [parietal (r= −0.72,P= 0.02), frontal (r= −0.72,P= 0.02), and occipital (r= −0.65,P= 0.04) cortices] and depressive symptoms [parietal (r= −0.68;P= 0.02), frontal (r= −0.65;P= 0.03), anterior cingulate (r= −0.61;P= 0.04), and temporal (r= −0.66;P= 0.02) cortices]. The finding that a similar relationship between GABAA‐BZR availability and anxiety symptoms was not observed in smokers suggests that there is a difference in GABAA‐BZR function, but not number, in smokers. Thus, while subsyndromal anxiety and depressive symptoms in nonsmokers may be determined in part by GABAA‐BZR availability, smoking disrupts this relationship. Aberrant regulation of GABAA‐BZR function in vulnerable smokers may explain why some smokers experience subsyndromal anxiety and depression. Synapse 63:1089–1099, 2009. © 2009 Wiley‐Liss, Inc.
Increased cortical nitric oxide release after phencyclidine administration
Authors: Pålsson Erik , Finnerty Niall , Fejgin Kim , Klamer Daniel , Wass Caroline , Svensson Lennart , Lowry John
Published: July 2009

Phencyclidine exerts psychotomimetic effects in humans and is used as a pharmacological animal model for schizophrenia. We, and others, have demonstrated that phencyclidine induces cognitive deficits in rats that are associated with schizophrenia. These cognitive deficits can be normalized by inhibition of nitric oxide synthase. The development of selective microelectrochemical nitric oxide sensors may provide direct evidence for the involvement of nitric oxide in these effects. The aim of the present study was to use LIVE (long term in vivo electrochemistry) to investigate the effect of phencyclidine, alone or in combination with the nitric oxide synthase inhibitor L‐NAME, on nitric oxide levels in the medial prefrontal cortex of freely moving rats. Phencyclidine (2 mg kg−1) produced an increase in cortical nitric oxide levels and this increase was ameliorated by L‐NAME (10 mg kg−1). Tentatively, the results from the present study provide a biochemical rationale for the involvement of nitric oxide in the phencyclidine model of schizophrenia. Synapse 63:1083–1088, 2009. © 2009 Wiley‐Liss, Inc.
Investigating teacher learning supports in high school biology curricular programs to inform the design of educative curriculum materials
Authors: Beyer Carrie J. , Delgado Cesar , Davis Elizabeth A. , Krajcik Joseph
Published: July 2009

Reform efforts have emphasized the need to support teachers' learning about reform‐oriented practices. Educative curriculum materials are one potential vehicle for promoting teacher learning about these practices. Educative curriculum materials include supports that are intended to promote both student and teacher learning. However, little is known about the extent to which existing curriculum materials provide support for teachers and the ways they can be improved. In this study, eight sets of high school biology curriculum materials were reviewed to determine their potential for promoting teacher learning. Design heuristics for educative curriculum materials were adapted for use as evaluation criteria. From this analysis, several themes emerged. First, the materials tended to provide support for teachers' subject matter knowledge and pedagogical content knowledge for students' ideas (e.g., misconceptions) but rarely for their pedagogical content knowledge of scientific inquiry. Second, the materials contained several implementation guidance supports but far fewer rationales for instructional decisions, which are an important feature of educative curriculum materials. Finally, the quality of support varied widely, differing in its degree of relevance, pedagogical helpfulness, and depth. The article concludes with recommendations for the redesign of existing curriculum materials. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 977–998, 2009