bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two‐dimensional electrons occupying multiple valleys in AlAs
Authors: Shayegan M. , De Poortere E. P. , Gunawan O. , Shkolnikov Y. P. , Tutuc E. , Vakili K. 
Published: August 2006

AbstractTwo‐dimensional electrons in AlAs quantum wells occupy multiple conduction‐band minima at the X‐points of the Brillouin zone. These valleys have large effective mass and g ‐factor compared to the standard GaAs electrons, and are also highly anisotropic. With proper choice of well width and by applying symmetry‐breaking strain in the plane, one can control the occupation of different valleys thus rendering a system with tuneable effective mass, g ‐factor, Fermi contour anisotropy, and valley degeneracy. Here we review some of the rich physics that this system has allowed us to explore. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magneto‐transport properties of lanthanum and calcium deficient manganites
Authors: Walha I. , Boujelben W. , Koubaa M. , Cheikh‐Rouhou A. , Haghiri‐Gosnet A. M. 
Published: August 2006

AbstractWe present a comparative study of the physical properties of the La0.5Ca0.5MnO3, La0.45□0.05Ca0.5MnO3 and La0.5Ca0.45□0.05MnO3 powder samples. Our synthesized samples have been elaborated using the conventional solid‐state reaction technique they crystallize in the orthorhombic perovskite structure with Pnma space group. Resistivity measurements show that the defect effects in the A site on the electrical properties are substantially different for both lacunar samples. Electrical investigations show a metallic‐semiconducting transition when temperature deceases for the calcium‐deficient sample, however we observe a semiconducting behavior in the whole temperature range 20‐300 K in the lanthanum‐deficient one. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inverse relation between photocurrent and absorption layer thickness in polymer solar cells
Authors: Hoppe Harald , Shokhovets Sviatoslav , Gobsch Gerhard 
Published: August 2006

AbstractOrganic solar cells based on polymer–fullerene bulk heterojunctions were optimised with respect to the short circuit photocurrent by means of optical modelling. Due to interference effects present in the thin film multilayer device, an inverse relation between active layer thickness and photocurrent was predicted and experimentally verified. Optimised photovoltaic devices yield power conversion efficiencies of 4%. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two methods for calculating the amount of refrigerant required for cyclic temperature testing of insulated packages
Authors: Matsunaga Kazuhisa , Burgess Gary , Lockhart Hugh 
Published: August 2006

AbstractThis paper describes two calculation methods for estimating the amount of refrigerant required to maintain the temperature inside a small insulating container within a desired range under cyclic temperature conditions. The first calculation method is for a phase change material (PCM) that absorbs and releases heat by melting and solidifying. The PCM used in this study had a phase change temperature of 23.5°C (74.3°F). An equation for estimating the amount of the PCM required under cyclic conditions is shown. Test packages were constructed to meet USP Controlled Room Temperature (CRT) requirements. Several cyclic tests were conducted with the calculated amount of PCM in the test packages. The results showed that the calculated amount of PCM did maintain the inside temperature within the range 21.4–25.8°C (70.5–78.4°F) throughout the tests. This range met the USP CRT requirement. The second calculation method is for unfrozen gel packs that absorb and release heat by changing temperature. The amount of unfrozen gel pack required to maintain temperature within the USP range was calculated. Several cyclic tests were conducted with the calculated amount of gel packs. The calculated amount was enough to meet the USP requirement. Good agreement between the experimental and calculated temperature profiles was also found. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of eggshell powder as nucleating agent on the structure, morphology and functional properties of normal corn starch foams
Authors: Xu Yixiang , Hanna Milford 
Published: August 2006

AbstractCorn starch and eggshell powder (with particle sizes of 4–5µm and 8–10µm) composite foams were prepared by extrusion. Effects of eggshell on the structure, morphology, physical properties (unit density and expansion ratio), mechanical properties (spring index and compressibility) and thermal behaviour (thermal transition and stability) of the foams were investigated. Foam cell size decreased and cell population increased with addition of eggshell into starch matrix. The foam unit density, expansion ratio and compressibility decreased significantly (p < 0.05), while the spring index increased significantly (p < 0.05) as the eggshell content increased from 0 to 6wt%. Further increasing eggshell content to 10wt% increased the unit density and compressibility and decreased the expansion ratio and spring index. The thermal transition and stability increased with the addition of eggshell. The optimum eggshell content was 6wt% and the smaller‐sized eggshell powder had a favourable effect on the functional properties of the foams. Copyright © 2006 John Wiley & Sons, Ltd.
Santulli Enterostomy Revisited: Indications in Adults
Authors: Anadol A. Ziya , Topgül Koray 
Published: August 2006

AbstractBackgroundSurgical patients frequently need some type of intestinal stomas for a wide spectrum of disorders. Maintaining effective and enough decompression of gastrointestinal tract, securing distal bowel segments and anastomosis are the primary goals of ostomy formation as well as providing a minimum complication rate of closure or “take‐down”.MethodIn this report, we present five adult patients who were operated for some kind of intestinal disease and required enterostomy. We preferred Santulli type of enterostomy which was formerly used by pediatric surgeons. In this technique, the proximal afferent bowel is fashioned into a stoma and anastomosed side‐to‐end with double layer sutures into the distal efferent bowel.ResultOne of the five patients died of systemic problems, other four did well in terms of surgical outcome of the stoma.ConclusionWe concluded that; although indications are limited, Santulli enterostomy can be performed in adult patients as effective as pediatric age group, particularly for its advantages in early restoration of intestinal continuity and diminished risk for post‐closure complications.
Fournier’s Gangrene: Risk Factors and Strategies for Management
Authors: Yanar Hakan , Taviloglu Korhan , Ertekin Cemalettin , Guloglu Recep , Zorba Unal , Cabioglu Neslihan , Baspinar Irfan 
Published: August 2006

AbstractObjectiveThe prognosis of Fournier’s gangrene (FG) depends on early diagnosis and management. In this study, our objective was to identify the distinct features of FG that may influence the clinical outcome.MethodsA retrospective chart review was performed in patients with a diagnosis of FG between January 1999 and December 2003. Etiological and predisposing factors, causative microbiological organisms, and clinical outcome were investigated.ResultsTwenty‐five men (71%) and 10 women (29%) were included in the study. Mean age was 59.7 ± 10.7 (range: 43–88) years. As a predisposing factor, diabetes mellitus (DM) was found to be in 46% of patients. All patients were treated by immediate debridement and wide‐spectrum antibiotics. More than one bacterium was found in 75% of the patients’ tissue cultures, and most frequently E. coli (43%) was identified. Although there were no etiological factors in 25 patients (71%), various etiological factors were found in 10 patients (29%). Multiple debridements were performed in the majority of the cases. The overall mortality rate was 40%. The mortality rates were found to be relatively higher in patients with diabetes mellitus (DM; 50%), with delayed admission to the hospital (45%), and in patients presenting with sepsis at the first admission to the hospital (78%) compared with others. In the logistic regression model, the presence of sepsis was as the only significant independent risk factor for mortality in FG.ConclusionsDespite the use of contemporary effective antibiotic treatment, aggressive debridements, and state‐of‐the‐art intensive care conditions, FG still has high mortality and morbidity rates. In our series mortality rates were found to be higher in patients with delayed admission to the hospital, those with DM, and those who initially presented with sepsis.
Cervical Epidural Anesthesia: A Safe Alternative to General Anesthesia for Patients Undergoing Cancer Breast Surgery
Authors: Singh A. P. , Tewari Mallika , Singh D. K. , Shukla Hari S. 
Published: August 2006

AbstractBackgroundGeneral anesthesia (GA) is the standard anesthesia for patients undergoing modified radical mastectomy (MRM) for breast cancer. Cervical epidural anesthesia (CEA) is practiced less often because of its reported complications. This prospective study aimed to evaluate the safety and efficacy of CEA as an anesthetic technique for MRM.Patients and MethodsFifty breast cancer patients with ASA (American Society of Anesthesiologists) grade I or II underwent MRM under CEA from September 2004 to January 2006. Anesthesia was induced with 10 ml of 1% lignocaine; adrenaline was administered through an 18‐gauge catheter in C6–C7 or C7–T1 epidural space. Postoperative analgesia was maintained with 0.125% bupivacaine through the epidural catheter.ResultsIn 49 (98%) patients surgery was conducted smoothly under CEA with good analgesia. 44 patients were awake during surgery. Five patients had to be given intravenous sedation with midazolam, and in one case the procedure was terminated after accidental dura puncture. There were no clinically significant variations in perioperative pulse and respiratory rate, and there was no fall in mean arterial blood pressure during the procedure. The mean preoperative anesthesia time and total cost of the procedure was 20.36 + 2.75 minutes and 12.19 + 2.2£, respectively. All patients were started on a liquid diet and mobilized 4 hours after surgery.ConclusionsCervical epidural anesthesia is a safe alternative to GA and was preferred by our patients because of its lower cost and reduced perioperative morbidity.
Might “Unique” Factors be “Common”? On the Possibility of Indeterminate Common–Unique Covariances
Authors: Grayson Dave 
Published: August 2006

AbstractThe present paper shows that the usual factor analytic structured data dispersion matrix Λ Ψ Λ’ + Δ can readily arise from a set of scores y = Λ η + ε, where the “common” (η) and “unique” (ε) factors have nonzero covariance: Γ = Cov(ε,η) ≠ 0. Implications of this finding are discussed for the indeterminacy of factor scores, and for the issue of invariance of factor analytic covariance models. The size of the problem is explored with numerical examples.
Bayesian Analysis of Nonlinear Structural Equation Models with Nonignorable Missing Data
Authors: Lee Sik-Yum , Tang Nian-Sheng 
Published: August 2006

AbstractA Bayesian approach is developed for analyzing nonlinear structural equation models with nonignorable missing data. The nonignorable missingness mechanism is specified by a logistic regression model. A hybrid algorithm that combines the Gibbs sampler and the Metropolis–Hastings algorithm is used to produce the joint Bayesian estimates of structural parameters, latent variables, parameters in the nonignorable missing model, as well as their standard errors estimates. A goodness-of-fit statistic for assessing the plausibility of the posited nonlinear structural equation model is introduced, and a procedure for computing the Bayes factor for model comparison is developed via path sampling. Results obtained with respect to different missing data models, and different prior inputs are compared via simulation studies. In particular, it is shown that in the presence of nonignorable missing data, results obtained by the proposed method with a nonignorable missing data model are significantly better than those that are obtained under the missing at random assumption. A real example is presented to illustrate the newly developed Bayesian methodologies.
Progress in plasmodial differentiation improves regularity of oscillating contractions in Physarum polycephalum
Authors: Helf Matthias , Achenbach Friedhelm 
Published: August 2006

AbstractBased on the knowledge about subcellular morphogenetic processes in the acellular slime mold Physarum polycephalum, we hypothesized that during differentiation of undifferentiated endoplasm to the highly differentiated complex structure of the contractile apparatus of this organism, the regularity of oscillating contractions must improve.We measured the endogenous contraction automaticity starting from the de novo generation within minutes after sampling small portions of undifferentiated endoplasm.The standard deviation of the normalized period duration of these samples was compared to the respective values of radial contractions of differentiated protoplasmic plasmodial strands. The mean normalized standard deviation in endoplasmic drops was 28.3 ± 12.2%. Respective values in protoplasmic strands were 10.0 ± 3.7%. The difference between the experimental groups was highly significant (p < 0.0001).We interpret the verification of our hypothesis as an indication that the very regular oscillating contractions in fully differentiated stages of Physarum require the complex structure of the sophisticated contractile apparatus, represented by the circular plasmalemma invagination system of protoplasmic strands, while the regularity is lower in stages, where the differentiation is still in progress. We believe that this is due to deficits in coordination capabilities, which need a directional and spatially oriented protoplasmic streaming as a precondition.
Possible role of NMDA receptors in antinociception induced by rilmenidine in mice in the formalin test
Authors: Sabetkasaie Masoomeh , Khansefid Niaz , Ladgevardi Mohammad Ali Raies Sadat 
Published: August 2006

AbstractObjectives:The aim of the study was to investigate the possible role of MK‐801, an NMDA antagonist, in analgesia induced by rilmenidine, an imidazoline (I1) agonist, in mice in the formalin test.Methods:25μl of formalin 2.5% was injected into the dorsal surface of the right hind paw of the mouse. Pain response was scored after formalin injection for a period of 50min. A weighted average of nociceptive score, ranging from 0 to 3, was calculated. The mean ±SEM of scores between 0–5 and 15–40min after formalin injection was presented.Results:The study showed that rilmenidine (1.25, 2.5 and 5mg/kg, i.p.) produced analgesia dose‐dependently (p<0.001) in formalin test. In addition, the results demonstrated that efaroxan (0.1 and 1mg/kg, i.p.) could reduce the antinociceptive effect of rilmenidine (2.5mg/kg, i.p.) (p<0.01) in animals, however, yohimbine (0.1 and 0.2mg/kg, i.p.) could not block the analgesia induced by rilmenidine (2.5mg/kg, i.p.) (p>0.05). On the other hand, MK‐801 (0.05mg/kg, i.p.) reduced the pain related behaviors in mice (p>0.05). Moreover, our findings demonstrated that MK‐801 (0.01mg/kg, i.p.) could potentiate the analgesic effect of rilmenidine (1.25mg/kg, i.p.) significantly (p<0.01).Conclusions:The present study suggests that imidazoline (I1) receptors play an important role in mediating the antinociception induced by rilmenidine in formalin test. Furthermore, it may be concluded that there is an interaction between NMDA receptors and imidazoline (I1) binding sites.
Ameliorative effect of combined administration of inducible nitric oxide synthase inhibitor with cyclooxygenase‐2 inhibitors in neuropathic pain in rats
Authors: Dudhgaonkar Shailesh P. , Tandan Surendra K. , Kumar Dinesh , Naik Ajit K. , Raviprakash V. 
Published: August 2006

AbstractObjectives: The objective of this study was to examine the effects of rofecoxib, meloxicam, both cyclooxygenase‐2 (COX‐2) inhibitors and aminoguanidine hydrochloride, an inducible nitric oxide synthase (iNOS) inhibitor and their combinations in neuropathic pain in rats.Methods: Neuropathy was induced by chronic constriction injury (CCI) of right sciatic nerve under ketamine anesthesia in rats. Effect of ED50 of aminoguanidine hydrochloride, rofecoxib and meloxicam administered orally was investigated using behavioral tests. Effect of combinations of aminoguanidine hydrochloride with rofecoxib and meloxicam was also investigated in neuropathic pain employing behavioral tests.Results: Behavioral tests, mechanical, thermal and cold stimuli confirmed the development of neuropathic pain after CCI. Aminoguanidine hydrochloride, rofecoxib and meloxicam when administered alone, produced significant increase in paw withdrawal threshold to mechanical stimuli at 6h in ipsilateral hind paw after CCI. Co‐administration of aminoguanidine hydrochloride (30mg/kg) with rofecoxib (1.31mg/kg) and meloxicam (1.34mg/kg) was also found to produce significant increase in paw withdrawal latencies to mechanical stimuli at 6h. Combined administration of aminoguanidine hydrochloride with meloxicam and rofecoxib produced significant rise in pain threshold for mechanical hyperalgesia in ipsilateral hind paw when compared with the groups treated with aminoguanidine hydrochloride, meloxicam and rofecoxib alone.Conclusion: Co‐administration of meloxicam and rofecoxib with aminoguanidine hydrochloride may be an alternative approach for the treatment of neuropathic pain.
Modulation of neuronal [Ca2+]iby caffeine is altered with aging
Authors: Alshuaib Waleed B. , Cherian Susan P. , Hasan Mohamed Y. , Fahim Mohamed A. 
Published: August 2006

AbstractVoltage‐dependent calcium channels play an important role in controlling many neuronal processes such as neuronal excitability and synaptic transmission. Any slight alteration in intracellular calcium concentration ([Ca2+]i) can have a considerable impact on various neuronal functions. The effects of caffeine on [Ca2+]iwere studied in CA1 hippocampal neurons of young (2 months) and old (24 months) C57BL mice. Fura 2‐AM fluorescence photometry was used to measure [Ca2+]iin the presence and absence of caffeine (100 μM) in response to KCl (26 mM) application. Caffeine enhanced the peak [Ca2+]ias compared to control solution in young mice (control: 325 ± 8 nM, caffeine: 402 ± 10 nM), but had no effect on the peak [Ca2+]iin old mice (control: 222 ± 6 nM, caffeine: 223 ± 7 nM). These results indicate that caffeine can impact neuronal functions through the modification of [Ca2+]i. The lack of caffeine‐induced modulation of [Ca2+]iin old mice suggests that this role of caffeine has been compromised with aging.
A Criterion‐Referenced Measure of Latex Allergy Knowledge
Authors: Kleinbeck S.V.M. , English N.L. , Sherley M.A. , Howes J. 
Published: August 2006

ABSTRACTThe exponential use of latex products has increased patients' and health care workers' sensitization to natural rubber latex. The purpose of this research study was to develop and test a set of items designed to measure professional nurses' knowledge about natural rubber latex reactions and interventions appropriate for latex precautions. The items were developed from research reports in the literature and changed to reflect the suggestions offered by experienced perioperative nurses (pilot = 8) and three nationally known experts in latex allergy responses. The revised form was mailed to the home or distributed at the workplace of perioperative nurses (n = 158). Criteria for item retention were <.90 difficulty index and clinical relevance. Certified nurses (ie, CNORs) scored significantly higher than other nurses who took the test at the same time (t‐test = 2.00, P =.05). A pretest and posttest evaluation of the revised 20 items was conducted before and after a latex allergy continuing education program during the spring of 1998. The current knowledge test (ie, version 1.1) has reliability (alpha =.80); content validity (CVI =.92); and accumulated evidence of construct validity (preinstruction mean = 14.16, postinstruction mean = 17.15, t‐paired = 10.54, df = 70, P = <.001). An empirically, developed professional nurse latex allergy competency test suitable for clinical use was the outcome of this research study.
Hospital Explores Winning Balance in Perioperative Education
Authors: Onstott Anne T. 
Published: August 2006

ABSTRACTAlthough there are a number of education models used today that expose bachelor of nursing degree students to perioperative nursing, producing nursing graduates who have the education and experience needed to work in the demanding perioperative arena is a challenge for education facilities. The University of Colorado Health Sciences Center, Denver, has developed a perioperative education model that interfaces with one of the university's clinical sites, University Hospital, Denver, to achieve a winning balance between perioperative education and employment. The model provides nursing students with a realistic perspective of the OR and gives the employer an opportunity to thoroughly evaluate potential employees—beyond a resume and references.
Moving from an Hourly Pay Model to a Professional Salary Model
Authors: Avigne Gail , Guin Peggy , Pittman Linda , Surdez Maureen 
Published: August 2006

ABSTRACTThe traditional hourly pay structure may no longer meet the needs of staff members, managers, or patients in the current health care environment. Staff members at a university surgical center ventured toward a professional salary model. The goals of the salary model were to increase professional practice, accountability, autonomy, and flexibility of nurses; increase overall efficiency of the facility; and to increase or maintain patient, staff member, and physician satisfaction. Data from this study indicate that the majority of these goals were met.
Harvesting and Implanting Allograft Bone
Authors: Carter Gordon 
Published: August 2006

ABSTRACTAllograft bone (ie, bone that is obtained from a donor) implantation is used for bone replacement and for reconstructing serious bone defects during total joint revision surgery. It is also used for bone replacement after large excisions of bone tumors. An extensive variety of laboratory tests must be completed, appropriate storage facilities for allograft bone have to be available, and protocols must be developed before a facility can set up a bone bank. Many ethical issues and nursing responsibilities need to be considered before the decision is made to use allograft bone. AORN J 70 (Oct 1999) 660‐670.
Exploring Frameless Stereotactic Image Guided Surgery
Authors: Tessman Charles 
Published: August 2006

ABSTRACTFrameless stereotactic image guided surgery (IGS)—a fairly new modality originally used in cranial neurosurgical procedures—has been found to have several advantages over traditional framed methods of three‐dimensional navigation. Frameless stereotactic IGS is proving useful in neurosurgical procedures by allowing screws to be placed in the spine more quickly and accurately than with traditional methods. As IGS becomes standard clinical practice for certain spinal procedures—overlapping both neurosurgery and orthopedic specialties—new ideas for surgical application of the technology are developing. Currently, frameless stereotactic IGS is being investigated for use in hardware placement in orthopedic procedures and for endoscopic navigation in otorhinolaryngologic sinus procedures. Frameless stereotactic IGS is expected to gain application approval in both orthopedic and otorhinolaryngologic specialties from the US Food and Drug Administration in the near future. AORN J 69 (March 1999) 498–512.