bluuebunny/crossref_metadata_2025 huggingface dataset:
Sudden Death Related to Advanced Coronary Atherosclerosis in Mini‐Pigs: Influence of some Drugs
Authors: Jacobsson Leif , Lundholm Lennart , Wingren Gun
Published: July 2010

Abstract: Advanced coronary atherosclerosis was produced in 30 mini‐pigs by a combination of a hypercholesterolaemic diet and X‐irradiation to the precordial region. Within 11–25 weeks after the irradiation, 13 of the 30 animals died a sudden death probably caused by coronary atherosclerosis. The contents of free and ester‐bound cholesterol in the right coronary artery were significantly higher in the animals which died spontaneously than in surviving animals. In an untreated group of 12 animals 7 died whereas in a group treated with β‐pyridylcarbinol only 1 out of 5 died. In the coronary arteries, the contents of both free and ester‐bound cholesterol were significantly lower in the β‐pyridylcarbinol‐treated animals. In a sulfinpyrazontreated group 3 out of 8, and in a metoprolol‐treated group 2 out of 5 animals died. None of these drugs reduced the accumulation of cholesterol in the coronary arteries. The rate of sudden death was 26 ± 6% (P<0.05) lower in the combined group of treated animals than in the untreated ones. By regular ECG recordings, signs which could predict the fatal outcome of the experiment were looked for. Although depressed ST segments were present before death in a few animals, this was not a regular phenomenon. It is concluded that advanced coronary atherosclerosis in mini‐pigs often leads to sudden death and that this animal model seems suitable for testing the potential therapeutic effects of drugs.
Sparteine Oxidation Polymorphism in Denmark
Authors: Brøsen K. , Otton S. V. , Gram L. F.
Published: July 2010

Abstract: Sparteine oxidation was polymorphic among 301 healthy Danish volunteers. Hence 22 subjects or 7.3% were phenotyped as poor metabolizers (PM) whereas 279 subjects were classified as extensive metaboliz–ers (EM). The metabolic ratio (MR) between sparteine and 2– and 5–dehydrosparteine (% of dose) in 12 hrs urine ranged from 0.11–12.6 in EM and from 30–394 in PM. Urinary excretion of 2– and 5–dehydrosparteine also discriminated between PM and EM. Age, sex, and smoking habits did not influence the MR. This study confirms that sparteine is a useful probe drug in pharmacogenetic investigations
The Effect of Lithium in Vitro and in Vivo on Dopamine‐sensitive Adenylate Cyclase Activity in Dopaminergic Areas of the Rat Brain
Authors: Geisler A. , Klysner R.
Published: July 2010

Lithium (5 and 20 mM) was found to inhibit the dopamine‐stimulated cyclic AMP formation in homogenates from rat striatum and olfactory tubercle, leaving basal and fluoride‐stimulated activities unaffected. The inhibition of dopamine‐stimulated adenylate cyclase was non‐competitive and dose‐dependent. However, in rats treated with lithium for four weeks, no alterations were found in basal, fluoride‐ and dopamine‐stimulated adenylate cyclase activities. It is suggested that lithium interferes with hormonal stimulation of adenylate cyclase activity by an interaction with the process regulating the transfer of the receptor‐hormone stimulus to the adenylate cyclase enzyme.
A Novel 1,4 Dihydropyridine, BAY K 8644, with Contractile Effects on Vascular Smooth Muscle
Authors: Mikkelsen E. , Nyborg N. C. B. , Kazda S.
Published: July 2010

The effect of a new 1,4‐dihydropyridine derivative, methyl‐1,4‐dihydro‐2,6‐dimethyl‐3‐nitro‐4‐(2‐trifluoromethylphenyl) pyridine‐5‐carboxylate, BAY K 8644, was studied on isolated thoracic aortae obtained from male Wistar‐Kyoto rats. In rat aorta BAY K 8644 had dual actions as the compound induced contractions in the concentration range 10−8‐10−5M and relaxation at higher concentrations. In low concentrations (10−8M) BAY K 8644 increased the contractile response to both noradrenaline and potassium and shifted the concentration response curves to the left while in high concentrations BAY K 8644 (10−4M) had a relaxant effect on preparations precontracted by potassium. The contractile response to BAY K 8644 was resistant to wash out in drug free medium but was totally abolished in Ca‐free medium. Re‐addition of Ca restored the contractile response in a concentration dependent manner. BAY K 8644, 10−6M, shifted the Ca‐concentration response curve in high potassium solution to the left and increased the maximal response. Phentolamine or propranolol had no effect neither on the contractile nor on the relaxant effect of BAY K 8644. The findings suggest that BAY K 8644 acts mainly by increasing the transmembrane influx of Ca in the vascular smooth muscle cells, and that this effect could be opposite to that of nifedipine. However, in high concentrations BAY K 8644 also seems to have a Ca‐entry blocking effect.
Pharmacokinetics and Pharmacodynamics of Emepronium Bromide (Cetiprin®) after Intravenous Administration in Man
Authors: Pilbrant Åke , Norlén Lars J.
Published: July 2010

Intravenous doses of 1, 5, 10 and 15 mg of emepronium bromide were given to three healthy volunteers. Emepronium serum concentration declined in a triexponential manner with half‐lives between 2.2–3.0 min., 1.0–1.6 hours and 5.1–13 hours, respectively. The initial dilution space (volume of the central compartment) varied between 4.1–7.51. The area under the serum concentration time curve increased linearly with dose, indicating constancy of total serum clearance (range: 24–38 1/hr) with dose. The renal clearance of emepronium varied with serum concentration; secretion in addition to glomerular filtration was evident. Tubular secretion of emepronium was half‐saturated at serum concentrations of ∼ 50 nmol/l. No obvious drug‐related effect on blood pressure was noted, whereas salivary secretion decreased and heart rate increased with 10–15% at emepronium serum concentrations of about 200 nmol/l. ECG recordings were without abnormalities after slow intravenous injections of emepronium bromide in doses of up to 15 mg. Since no adverse effects were noted, intravenous administration of emepronium bromide may be an alternative in situations where the drug is now used intramuscularly e.g. severe tenesmus in the urinary bladder.
Impaired Maternal Behaviour and Altered Central Serotonergic Activity in the Adult Offspring of Chronically Ethanol Treated Dams
Authors: Hård Ernest , Musi Barbara , Dahlgren I. Lena , Engel Jörgen , Larsson Knut , Liljequist Sture , Lindh Ann Sofie
Published: July 2010

Female rats were given 16% ethanol solution as the sole liquid during the entire period of gestation. At birth the offspring was removed and reared by foster dams consuming normal tap water. At adult age the female offspring showed deficiencies in their maternal behaviour; they built nests of poor quality and they displayed prolonged times for retrieving pups placed outside the nest. In the whole brains of the prenatally ethanol‐exposed females a decreased serotonin synthesis was observed. The offspring of the prenatally ethanol exposed mothers did not show any signs of disturbances in physical or behavioural development.
A Comparison of the Soft Gelatin Capsule and the Tablet Form of Temazepam
Authors: Salonen M. , Aantaa E. , Aaltonen L. , Hovi‐Viander M. , Kanto J.
Published: July 2010

Abstract: Pharmacokinetics and pharmacodynamics of the soft gelatin capsule and tablet form of temazepam were compared. In a single blind study, six healthy volunteers, in the supine position, took either a tablet of temazepam 20 mg or a soft gelatin capsule of temazepam 20 mg. Sixty gynaecological in‐patients received either a tablet or a soft gelatin capsule of temazepam 20 mg the night before surgery as premedication. Subjective parameters were assessed in the morning. The soft gelatin capsule yielded clearly higher serum concentrations during the first hour after administration. In the pharmacodynamic parameters there were slight but insignificant differences in favour of the capsule form. As a premedicant the capsule resulted in a significantly (P < 0.01) shorter delay in the onset of sedative action and to an almost significant (P < 0.05) delay in falling asleep; also an almost significantly (P < 0.05) longer action of sleep in comparison with the tablet.
Effects of Six Cholecystokinin (CCK) Fragments on Insulin Secretion in the Mouse
Authors: Ahrén Bo , Hedner Pavo , Lundquist Ingmar
Published: July 2010

Abstract: In a recent study it was demonstrated that the C‐terminal octapeptide of cholecystokinin (CCK‐26–33; often abbreviated CCK‐8) and CCK‐39 (= CCK‐6–33) potently and with the same efficacy stimulated basal insulin secretion when injected intravenously to mice. In the present study, the effects of four other CCK fragments, CCK‐30–33 (= CCK‐4), CCK‐1–33 (= CCK‐33), CCK‐1–21 (= CCK‐21) and CCK‐10–20, on basal and glucose‐induced insulin secretion were studied. It was found that CCK‐33 stimulated insulin secretion. At a dose level of 4.25 nmol/kg, plasma insulin concentrations were elevated by 58 ± 7 μU/ml (P < 0.001). On the contrary, neither CCK‐4, nor CCK‐21, nor CCK‐10–20 displayed any effect on basal insulin secretion, not even at high dose levels. When injecting CCK‐8, CCK‐33 or CCK‐39 at dose levels substimulatory on basal insulin secretion (0.53 nmol/kg), together with glucose, CCK‐39 potentiated glucose‐induced insulin secretion whereas CCK‐8 and CCK‐33 were without effects. In contrast, at the higher dose level of 5.3 nmol/kg, CCK‐8, CCK‐33, and CCK‐39 all potentiated glucose‐induced insulin secretion. The three other fragments, CCK‐4, CCK‐21, and CCK‐10–20, were all without effects on glucose‐induced insulin secretion. In conclusion, the potent stimulatory action on basal insulin secretion in the mouse exerted by various CCK fragments is confined to the C‐terminal octapeptide (= CCK‐8 or CCK‐26–33). Thus neither CCK‐4 nor the N‐terminal fragments display any effect. Further, the stimulatory CCK‐fragments also potentiate glucose‐induced insulin secretion; CCK‐39 being more potent in this respect than CCK‐8 or CCK‐33.
The Carry‐over Effects of Triazolam Compared with Nitrazepam and Placebo in Acute Emergency Driving Situations and in Monotonous Simulated Driving
Authors: Laurell Hans , Törnros Jan
Published: July 2010

Abstract: Eighteen healthy volunteers of both sexes, aged 20–34, were tested in the morning while undertaking real car driving avoidance manoeuvres and during monotonous simulated driving after 1 and 3 nights of medication with triazolam 0.25 mg, nitrazepam 5 mg or placebo. The study was a double‐blind, randomized, cross‐over study, where a minimum of 7 days wash‐out separated the 3 treatment periods. Nitrazepam was found to impair performance in the simulated task after 1 but not after 3 nights of medication. Performance in the triazolam condition was not significantly different from the other conditions on this task on either day. However, after one night of medication triazolam tended to score worse than placebo but better than nitrazepam. In real car driving a tendency was noted for nitrazepam to score worst, whereas the difference between placebo and triazolam was hardly noticeable. The same tendency appeared on both days.
Bronchodilating Plasma Concentrations of Enprofylline and Theophylline have Minor Cardiovascular Effects in Man
Authors: Conradson Thor‐Björn
Published: July 2010

Abstract: The cardiovascular effects with bronchodilating plasma concentration of theophylline (3.8–12.6 mg/l) and enprofylline (0.8–3.0 mg/l) were studied in six healthy male subjects by means of non‐invasive procedures. With these plasma concentrations only minor effects were noted with regard to heart rate, blood pressure and systolic time intervals. However, both xanthines seem to have a vasodilating ability and a weak positive inotropic effect on the heart.
O‐Dealkylation of Phenacetin in the Olfactory Rosette in Rainbow Trout (Salmo Gairdneri)
Authors: Brittebo E. B. , Darnerud P. O. , Larsson J. , Svanberg O. , Brandt I.
Published: July 2010

Abstract: Olfactory rosettes from trout (Salmo gairdneri) were found to metabolise (14C‐ethyl)‐phenacetin to 14CO2 in vitro. Based on wet weight, the rate of metabolism was lower than that in liver and gills. Based on protein content, the rate of metabolism was about equal to that in liver and gills. Addition of the cytochrome P‐450 inhibitors metyrapone, 9‐hydroxyellipticine and piperonyl butoxide significantly decreased the formation of 14CO2 from (14C‐ethyl)‐phenacetin in olfactory rosettes. Microautoradiography of rosettes incubated with (14C‐ethyl)‐phenacetin showed the presence of non‐extractable metabolites in the sensory and indifferent epithelium. Addition of metyrapone decreased the binding of radioactivity in the epithelia considerably. When olfactory rosettes were incubated with (14C‐dimethylamine)‐aminopyrine, no formation of 14CO2 was observed. The results are concluded to indicate that cytochrome P‐450 dependent enzyme activity is present in the epithelia of the trout olfactory rosette.
Adenine Nucleotides in Cultured Brain Cells after Exposure to Methyl Mercury and Triethyl Lead
Authors: Grundt I. K. , Bakken A. M.
Published: July 2010

Abstract: To obtain more information on the biochemical background, of methyl mercury (MeHg) and triethyl lead (Et3Pb) toxicity, the doses which were needed to alter the cellular content of adenine nucleotides were compared to doses which induced morphological alterations. Three‐week‐old cultures of brain cells from new‐born rat were incubated for 5–60 min. with 28, 16, and 8 × 10−6 M MeHg or with 3 × 10−6 M Et3Pb in the nutrition medium. MeHg at 28 and 16 × 10−6 M simultaneously changed the cell shape and reduced both the cellular content of adenine nucleotides and the relative level of ATP. In cells treated with 16 × 10−6 M MeHg, a cellular increase in inosine and hypoxanthine and an unaltered content of adenine nucleotides in the nutrition medium, points to an intracellular degradation of adenine nucleotides. Incubation with 8 × 10−6 M MeHg during the first hour of incubation, did not change the content of adenine nucleotides, however, MeHg induced a slowly progressing degeneration of cellular extensions. 3 × 10−6 M Et3Pb induced morphological alterations but no changes in cellular nucleotide levels. The results show that morphological alterations occur in MeHg and Et3Pb treated cultures at concentrations of the compounds which are too low to change the content and composition of cellular adenine nucleotides.
Changes in Axonally Transported Proteins in the Rat Visual System Following Systemic Methyl Mercury Exposure
Authors: Aschner Michael
Published: July 2010

Abstract: In an effort to understand the effect of methylmercury on protein synthesis and axonal transport, we have analysed the composition and rate of axonally transported proteins in the retinal ganglion cells of the mature rat. By means of scintillation spectrometry and autoradiography, it was established that systemic exposure to 4 mgHg/kg/day for four to six days, or twelve days, resulted in an increased rate and volume of transported protein‐bound radioactivity in the visual system of the mature rat. In an effort to characterize these changes, the composition of transported polypeptides was analysed by means of SDS polyacrylamide gel electrophoresis. Selective changes in the composition of transported polypeptides were evident. These changes of a small subset of proteins known as GAPs (growth‐associated proteins) are consistent with the suggestion that they may have been involved in growth‐specific functions during the early stages of methyl mercury exposure. We concluded that, during this period, retinal ganglion cells may express growth‐related genes and engage in regenerative processes.
Distribution of14C‐Ochratoxin A in the Rainbow Trout(Salmo gairdneri)
Authors: Fuchs Radovan , Appelgren Lars‐Erik , Hult Karl
Published: July 2010

Abstract:The nephrotoxic mycotoxin ochratoxin A was studied in rainbow trout by whole‐body autoradiography and scintillation counting using14C‐labelled toxin. After one single intravenous injection of 10 μCi/fish, corresponding to 160 ng toxin/g body weight, the tissue affinity was studied during an eight day period. As soon as 5 min. after injection the concentration of the radioactivity in the blood had dropped to one tenth of that in the kidney and the urinary bladder. The autoradiograms showed two patterns of blackening in the kidney, one diffuse in the pronephros and one very strong spotty blackening in the opistonephros. In addition to the kidney very high concentrations of radioactivity were also noticed in the bile and the pseudobranch. The muscular tissue of treated trouts contained almost no radioactivity during the whole experiment. Chemical analysis revealed that the radioactivity that could be extracted from the organs was mainly ochratoxin A.
ROLE OF ELEMENTS IN PATHOPHYSIOLOGY OF HYPERTENSION AND ANTIHYPERTENSIVE DRUG DEVELOPMENT.
Authors: Arora R.B. , Roy S. , Khan S.U.
Published: July 2010

Abstract Cadmium and Zinc levels were determined in 100 patients of Essential hypertension by Atomic Absorption Spectrophotometer. It was shown that the mean levels of Serum cadmium were 43.34% ± 6.5% higher and zinc were 28.42% ± 5.4% lower in hypertensives when compared with normo tensive controls. height of diastolic blood pressure and Serum cadmium levels was observed. Ajmaloon a preparation from Rauvolfia eerpentina with corrective herbs lowered the blood pressure effectively and significantly P∠0.001. The side effects were minimal. It also tends to decrease the elevated serum cadmium levels in hypertensive individuals. A plea for development of Catecholamine depleting agents as drug for hypertension is advanced.
What are the validated animal models for tendinopathy?
Authors: Lui P. P. Y. , Maffulli N. , Rolf C. , Smith R. K. W.
Published: July 2010

Chronic tendinopathy refers to a broad spectrum of pathological conditions in tendons and their insertion, with symptoms including activity‐related chronic pain. To study the pathogenesis and management strategies of chronic tendinopathy, studies in animal models are essential. The different animal models in the literature present advantages and limitations, and there is no consensus regarding the criteria of a universal tendinopathy animal model. Based on the review of literature and the discussion in the International Symposium on Ligaments and Tendons‐X, we concluded that established clinical, histopathological and functional characteristics of human tendinopathy were all important and relevant criteria to be met, if possible, by animal models. As tendinopathy is a progressive, multifactorial tendon disorder affecting different anatomical structures, it may not be realistic to expect a single animal model to study all aspects of tendinopathy. Staging of tendinopathy over time and clearer definition of tendinopathies in relation to severity and type would enable realistic targets with any animal model. The existing animal models can be used for answering specific questions (horses for courses) but should not be used to conclude the general aspects of tendinopathy neither in animals nor in human.
Correlating family nurse practitioners' perspectives of adult ADD/ADHD with employed pharmacotherapy: A pilot study
Authors: Martinson Jennifer , Tang Hsin‐Yi (Jean)
Published: July 2010

Purpose: This study explores how family nurse practitioners (FNPs) in the state of Washington view adulthood attention deficit disorder/attention deficit hyperactivity disorder (ADD/ADHD) and how these views affect the pharmacotherapy FNPs employ.

Data sources: A confidential survey containing 30 questions was mailed to self‐selected FNPs who practice in the state of Washington (N= 126). Descriptive and Kendall's rank correlations coefficient statistical methods were used for data analysis.

Conclusions: The majority of respondents do not hold negative views toward adults with ADD/ADHD and are aware that their personal views may affect how they treat the disorder. Most of the respondents agreed that given the likelihood of co‐morbidity of adult ADD/ADHD, it can be a challenge to diagnose the disorder. The predominant prescribed medications for adult ADD/ADHD are consistent with current pediatric guidelines, with the exception of buproprion, which was identified by 40% of the respondents as either their primary or secondary drug of choice for treating adult ADD/ADHD.

Implications for practice: Research effort needs to focus on the efficacy of buproprion for treating ADD/ADHD in adults. Moreover, exploration of the effectiveness of current pediatric guidelines to treat ADD/ADHD in adults must be assessed.
Evaluation and treatment of depression in patients with heart failure
Authors: Smith Louise
Published: July 2010

Purpose: The purpose of this article is to provide an overview of relevant clinical issues including pathophysiology, clinical presentation, assessment/diagnosis, and treatment strategies regarding depression in the heart failure (HF) patient. This information was synthesized to create a clinical protocol to guide the practitioner in identifying, diagnosing, and treating depression in adult HF patients. This protocol was designed for use in the primary care or HF clinic setting.

Data sources: PubMed and CINAHL were utilized to search for articles pertaining to HF and depression.

Conclusions: The presence of depression in HF is associated with a worsening prognosis, increased risk of death, rehospitalization, and functional decline. The practitioner must identify predisposing factors for depression and evaluate symptoms. Self‐rated screening instruments can assist the practitioner in identifying those with depression. Evidence is lacking regarding the treatment of depression in HF but selective serotonin reuptake inhibitors are likely the best option.

Implications for practice: Understanding depression as it occurs in patients with HF is critical. If depression is identified and properly managed it may lead to better patient outcomes.
Contrast‐enhanced magnetic resonance angiography of patent ductus arteriosus in a dog
Authors: Louvet A. , Duconseille A. C. , Lazard P.
Published: July 2010

Gadolinium‐enhanced three‐dimensional magnetic resonance angiography is a relatively new technique in the veterinary field. A mature dog with suspected patent ductus arteriosus underwent contrast‐enhanced magnetic resonance angiography at 1·0 T with a three‐dimensional fast low‐angle shot (FLASH) gradient‐echo technique. Qualitatively, three‐dimensional images of the ductus were particularly clear with surface reconstructions, and ductus diameters were easy to assess in native images. Contrast‐enhanced magnetic resonance angiography is a fast, relatively non‐invasive procedure that could be particularly useful when non‐surgical interventional procedures are anticipated for ductus occlusion.
Inactivation of Food‐borne Spoilage and Pathogenic Micro‐organisms on the Surface of a Photoactive Polymer
Authors: Zerdin Katherine , Scully Andrew D.
Published: July 2010

The photodynamic action of a novel photoactive polymer comprising covalently bound anthraquinone (AQ) moieties was evaluated after developing a methodology to reliably immobilize viable micro‐organisms onto polymer film surfaces. The survival of Escherichia coli, Bacillus cereus (vegetative cells and spores), Fusarium oxysporum and Saccharomyces cerevisiae microbes inoculated on the surface of inert polymeric substrates was assessed to determine the effect of inoculum composition, drying rate and exposure to ultraviolet (UV‐A) radiation. Their survival was highly dependent on microbial genus, with E. coli consistently displaying markedly shorter survival times than the other microbes, and B. cereus spores being the most resistant. Inoculation of the microbes onto the surface of the photoactive polymer films, followed by exposure to UV‐A radiation, dramatically accelerated the inactivation of all microbial types studied compared with their survival on the surface of inert polymer substrates. Simultaneous exposure to both oxygen and UV‐A radiation is required to affect cell survival, which is consistent with this effect most likely originating from the photoinduced production of singlet oxygen by the photoactive polymer. These results provide further compelling evidence that singlet oxygen produced exogenously by this photoactive polymeric substrate can successfully inactivate a broad spectrum of microbes on the substrate’s surface.
Effects of Different Doses of Low Power Continuous Wave He–Ne Laser Radiation on Some Seed Thermodynamic and Germination Parameters, and Potential Enzymes Involved in Seed Germination of Sunflower (Helianthus annuus L.)
Authors: Perveen Rashida , Ali Qasim , Ashraf Muhammad , Al‐Qurainy Fahad , Jamil Yasir , Raza Ahmad Muhammad
Published: July 2010

In this study, water‐soaked seeds of sunflower were exposed to He–Ne laser irradiation of different energies to determine whether or not He–Ne laser irradiation caused changes to seed thermodynamic and germination parameters as well as effects on the activities of germination enzymes. The experiment comprised four energy levels: 0 (control), 100, 300 and 500 mJ of laser energy and each treatment replicated four times arranged in a completely randomized design. The experimentation was performed under the greenhouse conditions in the net‐house of the Department of Botany, University of Agriculture, Faisalabad. The seed thermodynamic parameters were calculated according to seed germination thermograms determined with a calorimeter at 25.8°C for 72 h. Various thermodynamic parameters of seed (ΔH, (ΔS)e, (ΔS)c, (ΔS)e/Δt and (ΔS)c/Δt) were affected significantly due to presowing laser treatment. Significant changes in seed germination parameters and enzyme activities were observed in seeds treated with He–Ne laser. The He–Ne laser seed treatment resulted in increased activities of amylase and protease. These results indicate that the low power continuous wave He–Ne laser light seed treatment has considerable biological effects on seed metabolism. This seed treatment technique can be potentially employed to enhance agricultural productivity.
Does Graft Construct Lengthening at the Fixations Cause an Increase in Anterior Laxity Following Anterior Cruciate Ligament Reconstruction in vivo?
Authors: Smith Conrad K. , Hull M. L. , Howell S. M.
Published: July 2010

A millimeter-for-millimeter relation between an increase in length of an anterior cruciate ligament graft construct and an increase in anterior laxity has been demonstrated in multiple in vitro studies. Based on this relation, a 3 mm increase in length of the graft construct following surgery could manifest as a 3 mm increase in anterior laxity in vivo, which is considered clinically unstable. Hence, the two primary objectives were to determine whether the millimeter-for-millimeter relation exists in vivo for slippage-resistant fixation of a soft-tissue graft and, if it does not exist, then to what extent the increase in stiffness caused by biologic healing of the graft to the bone tunnel offsets the potential increase in anterior laxity resulting from lengthening at the sites of fixation. Sixteen subjects were treated with a fresh-frozen, nonirradiated, nonchemically processed tibialis allograft. Tantalum markers were injected into the graft, fixation devices, and bones. On the day of surgery and at 1, 2, 3, and 4 months, Roentgen stereophotogrammetric analysis was used to compute anterior laxity at 150 N of anterior force and the total slippage from both sites of fixation. A simple linear regression was performed to determine whether the millimeter-for-millimeter relation existed and a springs-in-series model of the graft construct was used to determine the extent to which the increase in stiffness caused by biological healing of the graft to the bone tunnel offset the increase in anterior laxity resulting from lengthening at the sites of fixation. There was no correlation between lengthening at the sites of fixation and the increase in anterior laxity at 1 month (R2=0.0, slope=0.2). Also, the increase in stiffness of the graft construct caused by biologic healing of the graft to the bone tunnel offset 0.7 mm of the 1.5 mm potential increase in anterior laxity resulting from lengthening at the sites of fixation. This relatively large offset of nearly 50% occurred because lengthening at the sites of fixation was small.
Mechanism of Hydrogen Formation in Solar Parabolic Trough Receivers
Authors: Moens Luc , Blake Daniel M.
Published: July 2010

Solar parabolic trough systems for electricity production are receiving renewed attention, and new solar plants are under construction to help meet the growing demands of the power market in the Western United States. The growing solar trough industry will rely on operating experience it has gained over the last two decades. Recently, researchers found that trough plants that use organic heat transfer fluids (HTFs) such as Therminol VP-1 are experiencing significant heat losses in the receiver tubes. The cause has been traced back to the accumulation of excess hydrogen gas in the vacuum annulus that surrounds the steel receiver tube, thus compromising the thermal insulation of the receiver. The hydrogen gas is formed during the thermal decomposition of the organic HTF that circulates inside the receiver loop, and the installation of hydrogen getters inside the annulus has proven to be insufficient for controlling the hydrogen buildup over the lifetime of the receivers. This paper will provide an overview of the chemical literature dealing with the thermal decomposition of diphenyl oxide and biphenyl, which are the two constituents of Therminol VP-1.
The SnO2/Sn Carbothermic Cycle for Splitting Water and Production of Hydrogen
Authors: Epstein Michael , Vishnevetsky Irina , Berman Alexander
Published: July 2010

The carboreduction in SnO2 to produce Sn and its hydrolysis with steam to generate hydrogen were studied. The SnO2/C/Sn system has several advantages compared with the most advanced cycle considered so far, which is the ZnO/C/Zn system. The most significant one is the lower reduction temperatures (850–900°C for the SnO2 versus 1100–1150°C for the ZnO). The rate of carbothermal reduction was studied experimentally. SnO2 powder (300 mesh, 99.9% purity) was reduced with beech charcoal and graphite using a thermogravimetric analysis apparatus and fixed bed flow reactor at a temperature range of 800–1000°C. Optimal temperature range for the reduction with beech charcoal is 875–900°C. The reaction time needed to reach conversion of SnO2 close to 100% is 5–10 min in this temperature range. The transmission electron microscopy results show that after cooling, the product of carboreduction contains mainly metallic Sn with a particle size of 1–3 μm. The hydrolysis step is crucial to the success of the entire cycle. Reactions between the steam and solid tin having as powder structure similar to the reduced one were performed at a temperature range of 350–600°C. Results of both the reduction and hydrolysis reactions are presented in addition to thermodynamic analysis of this cycle.
Incorporating Uncertainty into Probabilistic Performance Models of Concentrating Solar Power Plants
Authors: Ho Clifford K. , Kolb Gregory J.
Published: July 2010

A method for applying probabilistic models to concentrating solar-thermal power plants is described in this paper. The benefits of using probabilistic models include quantification of uncertainties inherent in the system and characterization of their impact on system performance and economics. Sensitivity studies using stepwise regression analysis can identify and rank the most important parameters and processes as a means to prioritize future research and activities. The probabilistic method begins with the identification of uncertain variables and the assignment of appropriate distributions for those variables. Those parameters are then sampled using a stratified method (Latin hypercube sampling) to ensure complete and representative sampling from each distribution. Models of performance, reliability, and cost are then simulated multiple times using the sampled set of parameters. The results yield a cumulative distribution function that can be used to quantify the probability of exceeding (or being less than) a particular value. Two examples, a simple cost model and a more detailed performance model of a hypothetical 100-MWe power tower, are provided to illustrate the methods.
Truncation of the Secondary Concentrator (CPC) as Means to Cost Effective Beam-Down System
Authors: Segal Akiba , Epstein Michael
Published: July 2010

A central solar plant based on beam-down optics is composed of a field of heliostats, a tower reflector (hyperboloid mirror), and a ground receiver interfaced at its aperture with one or a cluster of secondary concentrators (compound parabolic concentrator). In previous publications, a method was presented, illustrating the correlation between the tower reflector position and its size on one hand and the geometry, dimensions, and reflective area of the secondary concentrator on the other hand, both related to the heliostat field reflective area. Obviously, when one wishes to reduce the size of a tower reflector by locating it closer to the upper focal point, the image created at the lower focus will be broader, resulting in a larger secondary ground concentrator. The present paper describes a method for substantial decrease in the dimensions of the ground secondary concentrator cluster (and, implicitly, the concentrator's area) via truncation and some geometrical corrections without significant sacrifice of the optical performance. This offers a method for cost effective design of future central solar plants, utilizing the beam-down optics.
Influence of Measurement Equipment on the Uncertainty of Performance Data from Test Loops for Concentrating Solar Collectors
Authors: Janotte Nicole , Lüpfert Eckhard , Pitz-Paal Robert , Pottler Klaus , Eck Markus , Zarza Eduardo , Riffelmann Klaus-Jürgen
Published: July 2010

Parabolic trough concentrating collectors play a major role in the energy efficiency and economics of concentrating solar power plants. Therefore, existing collector systems are constantly enhanced and new types were developed. Thermal performance testing is one step generally required in the course of their testing and qualification. For outdoor tests of prototypes, a heat transfer fluid loop (single collector or entire loop) needs to be equipped with measurement sensors for inlet, outlet, and ambient temperature as well as irradiance, wind speed, and mass or volumetric flow rate to evaluate the heat balance. Assessing the individual measurement uncertainties and their impact on the combined uncertainty of the desired measurement quantity one obtains the significance of the testing results. The method has been applied to a set of EuroTrough collector tests performed at Plataforma Solar de Almería, Spain. Test results include the uncertainty range of the resulting modeling function and exemplify the effects of sensors and their specifications on the parameters leading to an uncertainty of ±1.7% points for the optical collector efficiency. The measurement uncertainties of direct normal irradiance and mass flow rate are identified as determining uncertainty contributions and indicate room for improvement. Extended multiple sensor deployment and improved calibration procedures are the key to further reducing measurement uncertainty and hence increasing testing significance.
Electricity Generation From a Compound Parabolic Concentrator Coupled to a Thermoelectric Module
Authors: Mgbemene Chigbo A. , Duffy John , Sun Hongwei , Onyegegbu Samuel O.
Published: July 2010

Generating electricity from the sun using a combination of a compound parabolic concentrator (CPC) and a thermoelectric module (TEM) has been studied. The system was modeled, analyzed, and tested. The model equations and the methodology used for the demonstration are presented and experimentally validated. The experimental setup comprised a manually fabricated CPC placed on a commercially available TEM. The results showed that the combination can generate and sustain enough power for a small appliance. It was also shown that there is enough dissipated heat from the system, which could be harnessed for additional uses. The cost is still high, about $35/Wp, but if credit is given for the thermal energy the initial cost goes down.
PV-Electrolyzer Plant: Models and Optimization Procedure
Authors: Artuso P. , Zuccari F. , Dell’Era A. , Orecchini F.
Published: July 2010

The work focused on the analysis of the connection between a photovoltaic (PV) plant and an electrolyzer for hydrogen production. On the basis of PV-plant and electrolyzer experimental data, the effectiveness of the models adopted in the simulation program has been verified in order to choose the best model and, eventually, modify some parameters. By running the simulations, the procedure to optimize the PV-plant and the electrolyzer combination has been established. In fact, the simulation results might be considered to size an electrolyzer as small as possible, which is able to exploit up to the maximum power actually produced by the PV-plant during a working year. This criterion allows minimizing the overall plant costs. Furthermore, the possibility of deleting the maximum power point tracker and the dc/dc converter has been analyzed. On the basis of the obtained results, this opportunity is preferable to avoid the energy losses in the power control system; and it is convenient even from an economic point of view, considering that the electronic device costs are comparable with the PV-plant ones.
Effects of Virus Size and Cell Stiffness on Forces, Work, and Pressures Driving Membrane Invagination in a Receptor-Mediated Endocytosis
Authors: Gefen Amit
Published: July 2010

A continuum model based on the contact mechanics theory was developed and used for evaluating virus indentation forces at the early stage of membrane invagination, as well as the work of the virus indentation forces and virus-cell contact pressures in a receptor-mediated endocytosis, depending on the virus size and virus/cell stiffnesses. The model indicated that early virus indentation forces are in the order of 1–10 pN and for a given extent of virus engulfment, they increase linearly with the elastic modulus of the host cell and also with the square of the virus radius. The work of invagination at the initial phase of virus endocytosis is in the order of tens of zeptojoules and peak virus-cell contact pressures at this stage are in the order of hundreds of Pascals to several kPa. For a given extent of virus engulfment, peak and average contact pressures increase linearly with the elastic modulus of the host cell but interestingly, they are negligibly affected by the virus size. The present model may be useful in the fields of cellular biomechanics, virology and nanodrug delivery to evaluate mechanical factors during the early phase of membrane invagination.
Anatomical Study of the Radius and Center of Curvature of the Distal Femoral Condyle
Authors: Kosel Jürgen , Giouroudi Ioanna , Scheffer Cornie , Dillon Edwin , Erasmus Pieter
Published: July 2010

In this anatomical study, the anteroposterior curvature of the surface of 16 cadaveric distal femurs was examined in terms of radii and center point. Those two parameters attract high interest due to their significance for total knee arthroplasty. Basically, two different conclusions have been drawn in foregoing studies: (1) The curvature shows a constant radius and (2) the curvature shows a variable radius. The investigations were based on a new method combining three-dimensional laser-scanning and planar geometrical analyses. This method is aimed at providing high accuracy and high local resolution. The high-precision laser scanning enables the exact reproduction of the distal femurs—including their cartilage tissue—as a three-dimensional computer model. The surface curvature was investigated on intersection planes that were oriented perpendicularly to the surgical epicondylar line. Three planes were placed at the central part of each condyle. The intersection of either plane with the femur model was approximated with the help of a b-spline, yielding three b-splines on each condyle. The radii and center points of the circles, approximating the local curvature of the b-splines, were then evaluated. The results from all three b-splines were averaged in order to increase the reliability of the method. The results show the variation in the surface curvatures of the investigated samples of condyles. These variations are expressed in the pattern of the center points and the radii of the curvatures. The standard deviations of the radii for a 90 deg arc on the posterior condyle range from 0.6 mm up to 5.1 mm, with an average of 2.4 mm laterally and 2.2 mm medially. No correlation was found between the curvature of the lateral and medial condyles. Within the range of the investigated 16 samples, the conclusion can be drawn that the condyle surface curvature is not constant and different for all specimens when viewed along the surgical epicondylar axis. For the portion of the condylar surface that articulates with the tibia during knee flexion-extension, the determined center points approximate the location of the centers of rotation. The results suggest that the concept of a fixed flexion-extension axis is not applicable for every specimen.
Ultrathin PbS Sheets by Two-Dimensional Oriented Attachment
Authors: Schliehe Constanze , Juarez Beatriz H. , Pelletier Marie , Jander Sebastian , Greshnykh Denis , Nagel Mona , Meyer Andreas , Foerster Stephan , Kornowski Andreas , Klinke Christian , Weller Horst
Published: July 2010

Manufacturing Nanomaterials

The exploration of many materials at the nanoscale has revealed properties that only emerge when working at these small dimensions. For device manufacture, materials need to be deposited or assembled in specific patterns.

Schliehe
et al.

(p.
550
; see the cover) show the oriented attachment of lead sulfide nanocrystals into two-dimensional sheets. The packing is driven by the choice of solvents that influence the interactions between the nanocrystals. The nanocrystals have excellent photoconductive properties and were incorporated into a photodetector without any additional chemical processing.
Connecting Biomass and Petroleum Processing with a Chemical Bridge
Authors: Bozell Joseph J.
Published: July 2010

Biomass-derived sugars can be converted to fuels via conventional petrochemical processing.
E. coli
, What a Noisy Bug
Authors: Tyagi Sanjay
Published: July 2010

Investigators detail striking genome-wide variation in gene expression between individual cells.
NSF Funding Request Faring Well in Congress
Authors: Mervis Jeffrey
Published: July 2010

While the 2011 budget requests of other U.S. research agencies are struggling to stay afloat in choppy fiscal seas, so far the National Science Foundation's is sailing through Congress largely intact.
Fermilab Physicists Don't See Higgs, Argue They Should Keep Looking
Authors: Cho Adrian
Published: July 2010

Quelling rumors, Fermilab physicists announced at the International Conference on High Energy Physics that they had
not
yet spotted a long-sought particle called the Higgs boson—although they have narrowed the range of its mass.
Making Smarter, Savvier Robots
Authors: Kean Sam
Published: July 2010

What machines of the future really need to learn, say experts who plan to have them explore the far reaches of the solar system, is more independent behavior.
Channelopathies: Decoding Disease Pathogenesis
Authors: Terzic Andre , Perez-Terzic Carmen
Published: July 2010

New research stratifies the origin of an inherited multisystem channelopathy, a finding that has implications for personalized diagnosis and therapy.
Cholera between 1991 and 1997 in Mexico Was Associated with Infection by Classical, El Tor, and El Tor Variants of
Vibrio cholerae
Authors: Alam Munirul , Nusrin Suraia , Islam Atiqul , Bhuiyan Nurul A. , Rahim Niaz , Delgado Gabriela , Morales Rosario , Mendez Jose Luis , Navarro Armando , Gil Ana I. , Watanabe Haruo , Morita Masatomo , Nair G. Balakrish , Cravioto Alejandro
Published: July 2010

Vibrio cholerae
O1 biotype El Tor (ET), the cause of the current 7th pandemic, has recently been replaced in Asia and Africa by an altered ET biotype possessing cholera toxin (CTX) of the classical (CL) biotype that originally caused the first six pandemics before becoming extinct in the 1980s. Until recently, the ET prototype was the biotype circulating in Peru; a detailed understanding of the evolutionary trend of
V. cholerae
causing endemic cholera in Latin America is lacking. The present retrospective microbiological, molecular, and phylogenetic study of
V. cholerae
isolates recovered in Mexico (
n
= 91; 1983 to 1997) shows the existence of the pre-1991 CL biotype and the ET and CL biotypes together with the altered ET biotype in both epidemic and endemic cholera between 1991 and 1997. According to sero- and biotyping data, the altered ET, which has shown predominance in Mexico since 1991, emerged locally from ET and CL progenitors that were found coexisting until 1997. In Latin America, ET and CL variants shared a variable number of phenotypic markers, while the altered ET strains had genes encoding the CL CTX (CTX
CL
) prophage,
ctxB
CL
and
rstR
CL
, in addition to resident
rstR
ET
, as the underlying regional signature. The distinct regional fingerprints for ET in Mexico and Peru and their divergence from ET in Asia and Africa, as confirmed by subclustering patterns in a pulsed-field gel electrophoresis (NotI)-based dendrogram, suggest that the Mexico epidemic in 1991 may have been a local event and not an extension of the epidemics occurring in Asia and South America. Finally, the CL biotype reservoir in Mexico is unprecedented and must have contributed to the changing epidemiology of global cholera in ways that need to be understood.
pfmdr1
Amplification Associated with Clinical Resistance to Mefloquine in West Africa: Implications for Efficacy of Artemisinin Combination Therapies
Authors: Witkowski Benoit , Iriart Xavier , Soh Patrice Njomnang , Menard Sandie , Alvarez Muriel , Naneix-Laroche Veronique , Marchou Bruno , Magnaval Jean-François , Benoit-Vical Françoise , Berry Antoine
Published: July 2010

We describe here a clinical failure in the treatment with mefloquine of acute falciparum malaria contracted in Africa and associated with
in vitro
mefloquine resistance and
pfmdr1
copy number amplification. This case raises the question of the presence and the evolution of this genotype in Africa, which is also known to alter the susceptibility to artemisinin combination therapy (ACT).
QUANTUM GRAVITY ON NEUTRINO MASS SQUARE DIFFERENCE
Authors: KORANGA BIPIN SINGH
Published: July 2010

We consider the non-renormalizable interaction term as a perturbation of the neutrino mass matrix. We assume that the neutrino masses and mixing arise through physics at a scale intermediate between Planck scale and the electroweak breaking scale. We also assume that, just above the electroweak breaking scale, neutrino masses are nearly degenerate and their mixing is bi-maximal. Quantum gravity (Planck scale effects) lead to an effective SU (2)L × U (1) invariant dimension-5 Lagrangian involving neutrino and Higgs fields. On symmetry breaking, this operator gives rise to correction to the above masses and mixing. The gravitational interaction MX = M P , we find that for degenerate neutrino mass spectrum, the considered perturbation term change the [Formula: see text] and [Formula: see text] mass square difference is unchanged above GUT scale. The nature of gravitational interaction demands that the element of this perturbation matrix should be independent of flavor indices. In this letter, we study the quantum gravity effects on neutrino mass square difference, namely modified dispersion relation for neutrino mass square differences.