bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of serotonin on cerebral circulation after middle cerebral artery occlusion
Authors: Muhonen Michael G. , Robertson Scott C. , Gerdes Jeffrey S. , Loftus Christopher M.
Published: June 2009

✓ Serotonin (5-HT) produces constriction of peripheral collateral blood vessels. Using an animal model, the authors tested the hypothesis that 5-HT constricts collateral vessels in the cerebrum. A branch of the middle cerebral artery (MCA) was occluded proximally and cannulated distally in anesthetized dogs. Blood flow to the area at risk for infarction was detected by perfusing the cannulated MCA branch with microsphere-free blood during systemic injection of radioactive microspheres (shadow flow technique). Blood flow to collateral-dependent and normal cerebrum was measured during intravenous infusion of 5-HT (10 and 40 mg/kg/minute). Serotonin produced a dose-related reduction of blood flow to collateral-dependent cerebrum, increased collateral vessel resistance in large cerebral arteries and collateral vessels, and decreased cerebral artery perfusion pressure. In contrast, blood flow to normal cerebrum was not altered because a decrease in small vessel resistance effectively compensated for a decrease in MCA perfusion pressure. These findings indicate that 5-HT produces constriction of collateral vessels in the cerebrum. This response is clearly different from normal small cerebral vessels, which dilate during 5-HT infusion.
Selective excision of adenomas originating in or extending into the pituitary stalk with preservation of pituitary function
Authors: Mason R. Bryan , Nieman Lynnette K. , Doppman John L. , Oldfield Edward H.
Published: June 2009

✓ When the surgeon identifies an adenoma within the gland and selectively excises it, endocrine-active pituitary tumors are usually cured and pituitary function is preserved. Occasionally ectopic adenomas arise primarily in the pituitary stalk or arise superiorly in the midportion of the anterior lobe and extend upward within the stalk. To determine if these tumors can be selectively excised with preservation of pituitary function, the authors examined the outcome of selective adenomectomy in 10 patients with Cushing's disease with an ectopic adenoma originating in, and confined to, the stalk (four microadenomas) or an adenoma extending superiorly through the diaphragma sella and into the stalk (five microadenomas and one macroadenoma) from an operative series of 516 patients with Cushing's disease.

To reach the adenoma transsphenoidally in these patients, the diaphragma sella was incised anteroposteriorly in the midline to the anterior edge of the stalk, the suprasellar cistern was entered, and the adenoma was selectively excised using care to limit injury to the infundibulum. After selective adenomectomy, Cushing's disease remitted in all patients. All patients were hypocortisolemic immediately after surgery and required hydrocortisone for up to 21 months. Apart from the adrenal axis, pituitary function was normal in five patients in the immediate postoperative period, including two patients with tumors confined to the stalk and three patients with preoperative hypothyroidism (one patient) and/or hypogonadism (three patients). Three others with transient postoperative hypothyroidism (one patient) or diabetes insipidus (two patients) had normal pituitary function within 7 months of surgery. One patient with hypothyroidism and one with hypogonadism before surgery had panhypopituitarism postoperatively. A patient with a microadenoma located high in the stalk next to the optic chiasm had bitemporal hemianopsia postoperatively.

These results demonstrate the feasibility of achieving curative transsphenoidal resection and preservation of pituitary function in cases of pituitary adenomas that are confined to the pituitary stalk or tumors that extend superiorly within the stalk from an intrasellar origin.
Endovascular treatment of ruptured posterior circulation aneurysms using electrolytically detachable coils
Authors: Nichols Douglas A. , Brown Robert D. , Thielen Kent R. , Meyer Fredric B. , Atkinson John L. D. , Piepgras David G.
Published: June 2009

✓ The authors report their experience using electrolytically detachable coils for the treatment of ruptured posterior circulation aneurysms. Twenty-six patients with 28 posterior circulation aneurysms were treated. All patients were referred for endovascular treatment by experienced vascular neurosurgeons. Patients underwent follow-up angiography immediately after treatment, 1 to 6 weeks posttreatment, and 6 months posttreatment. Six-month follow-up angiograms obtained in 19 patients with 20 aneurysms demonstrated that 18 (90%) of the 20 aneurysms were 99 to 100% occluded, one aneurysm (5%) was approximately 90% occluded, and one aneurysm (5%) was approximately 75% occluded. The patient with the aneurysm that was approximately 75% occluded needed additional treatment, consisting of parent artery balloon occlusion, and was considered a treatment failure (3.8% of patients). There was one treatment-associated mortality (3.8%) but no treatment-associated serious neurological or nonneurological morbidity in the patient group. There was no recurrent aneurysm rupture during treatment or during the mean 27-month follow-up period.

Endovascular treatment of ruptured posterior circulation aneurysms with electrolytically detachable coils can be accomplished with low morbidity and mortality rates. The primary goal of treatment—preventing recurrent aneurysm—can be achieved over the short term.

Endovascular coil occlusion will play an important role in the treatment of ruptured posterior circulation aneurysms, particularly if long-term efficacy in preventing recurrent aneurysm hemorrhage can be documented.
Occurrence of severe vasospasm following intraventricular hemorrhage from an arteriovenous malformation
Authors: Maeda Keiichiro , Kurita Hiroki , Nakamura Tsuneo , Usui Masaaki , Tsutsumi Kazuo , Morimoto Tadashi , Kirino Takaaki
Published: June 2009

✓ The authors present two rare cases of severe cerebral vasospasm following the rupture of arteriovenous malformations (AVMs). Computerized tomography revealed intracerebral hemorrhage in the thalamus in one case and in the putamen in the other, both accompanied by cast formation of intraventricular clots without radiological evidence of subarachnoid hemorrhage. Initial angiograms showed arterial narrowing of the bilateral internal carotid arteries in the supraclinoid portion but failed to demonstrate an arteriovenous shunt. Subsequent angiograms clearly demonstrated the existence of an AVM. Radiological features and possible mechanisms are discussed.
Reversal and prevention of cerebral vasospasm by intracarotid infusions of nitric oxide donors in a primate model of subarachnoid hemorrhage
Authors: Pluta Ryszard M. , Oldfield Edward H. , Boock Robert J.
Published: June 2009

✓ Decreased endothelium-derived relaxing factor, nitric oxide (NO), in the arterial wall has been hypothesized to be a potential cause of cerebral vasospasm following subarachnoid hemorrhage (SAH). The authors sought to determine whether intracarotid infusions of newly developed NO-donating compounds (NONOates) could reverse vasospasm or prevent the occurrence of cerebral vasospasm in a primate model of SAH. Twenty-one cynomolgus monkeys were studied in two experimental settings. In an acute infusion experiment, saline or NONOate was infused intracarotidly in four normal monkeys and in four monkeys after onset of SAH. During the infusions regional cerebral blood flow (rCBF) was measured in eight animals and CBF velocity in two. In a chronic infusion experiment, saline (four animals) or NONOate (diethylamine-NO [three animals] or proli-NO [six animals]) was infused intracarotidly in monkeys for 7 days after SAH. In acute infusion experiments, 3-minute intracarotid diethylamine-NO infusions reversed arteriographically confirmed vasospasm of the right middle cerebral artery (MCA) (as viewed on anteroposterior projection, the decrease in area was 8.4 ± 4.3% in the treatment group compared with 35 ± 12% in the control group; p < 0.004), increased rCBF by 31 ± 1.9% (p < 0.002), and decreased the mean systolic CBF velocity in the right MCA. In a long-term infusion experiment, the area of the right MCA in control animals decreased by 63 ± 5%. In animals undergoing a 7-day continuous glucantime-NO intracarotid infusion, the area of the right MCA decreased by 15 ± 6.2%, and in animals undergoing a 7-day proli-NO infusion, the area of the right MCA decreased by 11 ± 2.9% (p < 0.05). The mean arterial blood pressure decreased in the glucantime-NO group from 75 ± 12 mm Hg (during saline infusion) to 57 ± 10 mm Hg (during glucantime-NO infusion; p < 0.05), but it was unchanged in animals undergoing proli-NO infusion (76 ± 12 mm Hg vs. 78 ± 12 mm Hg). Results of these experiments show that cerebral vasospasm is both reversed and completely prevented by NO replacement. However, only the use of regional infusion of the NONOate with an extremely short half-life avoided a concomitant decrease in arterial blood pressure, which could produce cerebral ischemia in patients with impaired autoregulation of CBF after the rupture of an intracranial aneurysm.
Paraspinal calcinosis associated with progressive systemic sclerosis
Authors: Arginteanu Marc S. , Perin Noel I.
Published: June 2009

✓ The authors describe a case of paraspinal calcinosis in a 65-year-old woman with progressive systemic sclerosis. Although calcinosis occurs in up to 27% of cases of progressive systemic sclerosis, symptomatic paraspinal calcinosis is extremely rare. In the case reported here, multiple cervical facet joints were compromised by progressive calcinosis, leading to glacial spinal instability. Internal fixation was indicated to correct the instability and decompress the spinal canal. Medical therapy was instituted to arrest or reverse the ongoing calcinosis.
Efficacy of sphenopalatine ganglion blockade in 66 patients suffering from cluster headache: a 12- to 70-month follow-up evaluation
Authors: Sanders Michael , Zuurmond Wouter W. A.
Published: June 2009

✓ This study was conducted to evaluate the efficacy, based on 12- to 70-month follow-up data, of radiofrequency (RF) lesions of the sphenopalatine ganglion made in patients suffering from cluster headache. Sixty-six patients suffering from either episodic (Group A, 56 patients) or chronic (Group B, 10 patients) cluster headache who were not responsive to pharmacological management were treated by RF lesioning in the sphenopalatine ganglion.

Complete relief of pain was achieved in 34 (60.7%) of 56 patients in Group A and in three (30%) of 10 patients in Group B. No relief was found in eight patients (14.3%) in Group A and in four (40%) in Group B. The mean time of follow up was 29.1 ± 10.6 months in Group A and 24 ± 9.7 months in Group B, ranging from 12 to 70 months. With regard to side effects and complications, temporary postoperative epistaxis was observed in eight patients and a cheek hematoma in 11 patients; a partial RF lesion of the maxillary nerve was inadvertently made in four patients. Nine patients complained of hypesthesia of the palate, which disappeared in all cases within 3 months.

The authors conclude that RF lesioning in the sphenopalatine ganglion via the infrazygomatic approach may be performed in patients suffering from cluster headache that does not respond to pharmacological therapy.
Contribution of vasogenic and cellular edema to traumatic brain swelling measured by diffusion-weighted imaging
Authors: Barzó Pál , Marmarou Anthony , Fatouros Panos , Hayasaki Koji , Corwin Frank
Published: June 2009

✓ The contribution of brain edema to brain swelling in cases of traumatic brain injury remains a critical problem. The authors believe that cellular edema, the result of complex neurotoxic events, is the major contributor to brain swelling and that vasogenic edema, secondary to blood-brain barrier compromise, may be overemphasized. The objective of this study, therefore, was to quantify temporal water content changes and document the type of edema that forms during the acute and late stages of edema development following closed head injury (CHI). The measurement of brain water content was based on magnetic resonance imaging—determined values of tissue longitudinal relaxation time (T1-weighted imaging) and their subsequent conversion to percentage of water, whereas the differentiation of edema formation (cellular vs. vasogenic) was based on the measurement of the apparent diffusion coefficient (ADC) by diffusion-weighted imaging.

A new impact-acceleration model was used to induce CHI. Thirty-six adult Sprague—Dawley rats were separated into two groups: Group I, control (six animals); and Group II, trauma (30 animals). Fast ADC measurements (localized, single-voxel) were obtained sequentially (every minute) up to 1 hour postinjury. The T1-weighted images, used for water content determination, and the diffusion-weighted images (ADC measurement with conventional diffusion-weighted imaging) were obtained at the end of the 1st hour postinjury and on Days 1, 3, 7, 14, 28, and 42 in animals from the trauma and control groups.

In the animals subjected to trauma, the authors found a significant increase in ADC (10 ± 5%) and brain water content (1.3 ± 0.9%) during the first 60 minutes postinjury. This is consistent with an increase in the volume of extracellular fluid and vasogenic edema formation as a result of blood-brain barrier compromise. This transient increase, however, was followed by a continuing decrease in ADC that began 40 to 60 minutes postinjury and reached a minimum value on Days 7 to 14 (10 ± 3% reduction). Because the water content of the brain continued to increase during the first 24 hours postinjury (1.9 ± 0.9%), it is suggested that the decreased ADC indicated cellular edema formation, which started to develop soon after injury and became dominant between 1 and 2 weeks postinjury.

The study provides supportive evidence that cellular edema is the major contributor to posttraumatic swelling in diffuse CHI and defines the onset and duration of the increase in cellular volume.
Inhibitory Effects of Morinda officinalis Extract on Bone Loss in Ovariectomized Rats
Authors: Li Nan , Qin Lu-Ping , Han Ting , Wu Yan-Bin , Zhang Qiao-Yan , Zhang Hong
Published: June 2009

The present study was undertaken to investigate the protective effects of ethanol extract from the root of Morinda Officinalis (RMO) on ovariectomy-induced bone loss. Administration of RMO extract increased trabecular bone mineral content and bone mineral density of tibia, improved the levels of phosphorus (P), calcium (Ca) and OPG, decreased the levels of DPD/Cr, TRAP, ACTH and corticosterone, but did not reverse the levels of ALP, TNF-α and IL-6 in serum of ovariectomized rats. These findings demonstrated that RMO extract reduced bone loss in ovariectomized rats, probably via the inhibition of bone resorption, but was not involved with bone formation. Anthraquinones and polysaccharides from Morinda officinals could be responsible for their antiosteoporotic activity, and the action mechanism of these constituents needs to be further studied. Therefore, RMO has the potential to develop a clinically useful antiosteoporotic agent.
Dammarane-type Triterpene Saponins from the Flowers of Panax notoginseng
Authors: Wang Jing-Rong , Yamasaki Yuko , Tanaka Takashi , Kouno Isao , Jiang Zhi-Hong
Published: June 2009

Four new dammarane-type triterpene saponins named floranotoginsenosides A (1), B (2), C (3) and D (4), together with five known triterpene saponins, were isolated from the flowers of Panax notoginseng. Their structures were elucidated on the basis of spectral and chemical evidence.
An Overview of Recent Strategies in Pathogen Sensing
Authors: Heo Jinseok , Hua Susan Z
Published: June 2009

Pathogenic bacteria are one of the major concerns in food industries and water treatment facilities because of their rapid growth and deleterious effects on human health. The development of fast and accurate detection and identification systems for bacterial strains has long been an important issue to researchers. Although confirmative for the identification of bacteria, conventional methods require time-consuming process involving either the test of characteristic metabolites or cellular reproductive cycles. In this paper, we review recent sensing strategies based on micro- and nano-fabrication technology. These technologies allow for a great improvement of detection limit, therefore, reduce the time required for sample preparation. The paper will be focused on newly developed nano- and micro-scaled biosensors, novel sensing modalities utilizing microfluidic lab-on-a-chip, and array technology for the detection of pathogenic bacteria.
La ecología cultural política y el estudio de regiones en México
Authors: Fábregas Puig Andrés
Published: June 2009

El artículo muestra por qué la ecología cultural, entendida como un método para indagar en las relaciones entre el medio ambiente y los procesos culturales ha arraigado en una generación de antropólogos mexicanos como consecuencia del magisterio de Ángel Palerm y Eric Wolf. La aplicación práctica de las teorías de Steward a los procesos de formación regional mexicana vinculados a usos políticos de tecnologías hidráulicas como parte, tanto de estrategias culturales de adaptación como de control político del agua en el proceso de producción de alimentos, ha puesto de manifiesto que la ecología cultural, entendida como manejo cultural de entornos naturales, al igual que la economía, es diseñada y manejada políticamente en el contexto de sociedades profundamente desiguales con consecuencias maladaptantes.
Pensar el mundo, practicar el entorno. Etnografías y reflexiones desde una antropología de las territorialidades
Authors: Nates Cruz Beatriz
Published: June 2009

Este artículo mostrará y analizará desde una visión antropológica la configuración y las formas que toman la definición y ubicación del mundo y el entorno, tanto como posturas filosóficas, que como objetivaciones físicas y geográficas entre culturas diferentes: los indígenas y yanaconas del Macizo Colombiano, los llamados “paisas” de los Andes centrales de Colombia y los habitantes del sur de Francia y norte de España en su relación con los inmigrantes del norte de Europa. Aunque haya distancia cultural, física y social, los contenidos tendrán a menudo posturas relacionales.
El gusto en los cuerpos veracruzanos: retóricas y prácticas culinarias y sexuales
Authors: Flores Martos Juan Antonio
Published: June 2009

Esta contribución se enmarca en la teoría y corriente de la antropología de los sentidos, y en particular, intenta explorar el sentido del gusto —el gusto sensual— en la cultura urbana de Veracruz, México. El artículo es un estudio etnográfico sobre el lugar que las retóricas y prácticas referidas a comidas y al sexo tienen en la sociedad e imaginación social veracruzana, a partir de mi trabajo de campo realizado en los años 90 en esta ciudad. Historias y discursos diferentes son analizados en una aproximación para comprender la “gustación del mundo” hegemónica y singular entre las gentes de Veracruz. Centro mi análisis en los campos de la sociabilidad, la gastronomía y la sexualidad que comprometen los sentidos en la vida cotidiana veracruzana. De modo especial, estudio lo sensorial como retórica identitaria, los platos veracruzanos como mapamundis culturales, el gusto de ambigú y el placer compuesto y el gusto libertino de los varones veracruzanos. Finalmente, identifico las principales categorías morfológicas del gusto veracruzano.
Naturaleza y cultura en los rituales de San Antonio
Authors: Velasco Maíllo Honorio M.
Published: June 2009

En este artículo reflexiono en torno al culto de San Antonio Abad o San Antón como una muestra de la fusión naturaleza y cultura a través de los ritos que llevan a cabo las distintas poblaciones que festejan a este santo. Las prácticas festivas de este “santo viejo” están asociadas a prácticas precristianas relacionadas con el culto al fuego y la protección de los animales. El culto de este santo popular estuvo muy extendido por Europa y fue exportado a las colonias americanas. Sirve como expresión muy clara de cómo las apropiaciones populares se han producido una y otra vez estimuladas por iniciativas eclesiásticas y se han desarrollado según los modos propios las prácticas propuestas, rozando en ocasiones la heterodoxia y expresando mecanismos de resistencia al cambio. Aunque por otra parte este culto se ha mantenido gracias a que se ha adaptado; el campo se industrializó y dejó de celebrarse la bendición de animales para pasar a bendecir las máquinas. Cuando prácticamente se ha abandonado la explotación ganadera, el culto se adapta a la nueva sensibilidad ecológica y se bendicen las mascotas. San Antonio concilia naturaleza y cultura, lo rural con lo urbano, los cultos remotos con la nueva ecología.
Online pattern recognition based on a generalized hidden Markov model for intraoperative vital sign monitoring
Authors: Yang Ping , Dumont Guy A. , Ansermino J. Mark
Published: June 2009

The trend patterns of vital signs provide significant insight into the interpretation of intraoperative physiological measurements. We have modeled the trend signal of a vital sign parameter as a generalized hidden Markov model (also known as a hidden semi‐Markov model). This model treats a time series as a sequence of predefined patterns and describes the transition between these patterns as a first‐order Markov process and the intra‐segmental variations as different dynamic linear systems. Based on this model, a switching Kalman smoother combines a Bayesian inference process with a fixed‐point Kalman smoother in order to estimate the unconditional true signal values and generates the probability of occurrence for each pattern online. The probabilities of pattern transitions are tested against a threshold to detect change points. A second‐order generalized pseudo‐Bayesian algorithm is used to summarize the state propagation over time and reduces the computational overhead. The memory complexity is reduced using linked tables. The algorithm was tested on 30 simulated signals and 10 non‐invasive‐mean‐blood‐pressure trend signals collected at a local hospital. In the simulated test, the algorithm achieved a high accuracy of signal estimation and pattern recognition. In the test on clinical data, the change directions of 45 trend segments, out of the 54 segments annotated by an expert, were correctly detected with the best performing threshold, and with the introduction of only 8 false‐positive detections. The proposed method can detect the changes of trend patterns in a time series online, while generating quantitative evaluation of the significance of detection. This method is promising for physiological monitoring as the method not only generates early alerts, but also summarizes the temporal contextual information for a high‐level decision support system. Copyright © 2009 John Wiley & Sons, Ltd.
Synchrotron‐Based Micro‐CT and Refraction‐Enhanced Micro‐CT for Non‐Destructive Materials Characterisation
Authors: Müller Bernd R. , Lange Axel , Harwardt Michael , Hentschel Manfred P.
Published: June 2009

X‐ray computed tomography is an important tool for non‐destructively evaluating the 3‐D microstructure of modern materials. To resolve material structures in the micrometer range and below, high brilliance synchrotron radiation has to be used. The Federal Institute for Materials Research and Testing (BAM) has built up an imaging setup for micro‐tomography and ‐radiography (BAMline) at the Berliner storage ring for synchrotron radiation (BESSY). In computed tomography, the contrast at interfaces within heterogeneous materials can be strongly amplified by effects related to X‐ray refraction. Such effects are especially useful for materials of low absorption or mixed phases showing similar X‐ray absorption properties that produce low contrast. The technique is based on ultra‐small‐angle scattering by microstructural elements causing phase‐related effects, such as refraction and total reflection. The extraordinary contrast of inner surfaces is far beyond absorption effects. Crack orientation and fibre/matrix debonding in plastics, polymers, ceramics and metal‐matrix‐composites after cyclic loading and hydro‐thermal aging can be visualized. In most cases, the investigated inner surface and interface structures correlate to mechanical properties. The technique is an alternative to other attempts on raising the spatial resolution of CT machines.
Direct Conversion of Single‐Layer SnO Nanoplates to Multi‐Layer SnO2 Nanoplates with Enhanced Ethanol Sensing Properties
Authors: Li Kun‐Mu , Li Yi‐Jing , Lu Ming‐Yen , Kuo Chung‐I , Chen Lih‐Juann
Published: June 2009

Direct conversion of single‐layer SnO nanoplates to multi‐layer SnO2 nanoplates is achieved by annealing in an O2 ambient at 700 °C. For 50 ppm ethanol, the sensitivities of the multi‐layer SnO2 nanoplates are more than double that of single‐layer SnO2 nanoplates, which are also formed from the single‐layer SnO. The higher sensitivity of the multi‐layer nanoplates is attributed to their larger surface/volume ratio. The facile fabrication of interconnected multi‐layer SnO2 nanoplates at low temperature directly on a Si substrate and sensing chip without the aid of catalysts offers vast advantages over competing methods for the fabrication of high‐sensitivity SnO2 sensors.
Sample Target Substrates with Reduced Spot Size for MALDI‐TOF Mass Spectrometry Based on Patterned Self‐Assembled Monolayers
Authors: Herzer Nicole , Eckardt Rebecca , Hoeppener Stephanie , Schubert Ulrich S.
Published: June 2009

The wetting properties of structured self‐assembled monolayers are used to fabricate sample target substrates for MALDI‐TOF mass spectrometry. Combining the advantages of a hydrophobic‐hydrophilic surface pattern and the possibility of obtaining micrometer patterns allows an increase in the sensitivity of MALDI‐TOF mass spectrometry analysis and a reduction in the traceable concentration down to fmol µL−1. This easy, cheap and fast patterning process provides substrates that allow sensitive, high‐resolution mass spectrometry of dilute solutions.
Repeated Transfer of Colloidal Patterns by Using Reversible Buckling Process
Authors: Hyun Dong Choon , Moon Geon Dae , Cho Eun Chul , Jeong Unyong
Published: June 2009

The reversible nature of buckling is employed to repeatedly transfer colloids assembled in buckling patterns to flat surfaces. The cycle of colloidal loading–transfer–buckling is repeatedly carried out to fabricate the same colloidal patterns. The key to success is the reduction in the amplitude of the buckling patterns to a few nanometers as well as the recovery of initial buckling patterns after repeated stretching. The reduced buckling amplitude by poststretching or thermal annealing embosses the colloids assembled in the trenches of the buckling patterns, which enables the transfer regardless of the size, species, or layer thickness of the particles. This report demonstrates various transferred patterns composed of colloidal crystals, fluorescence hydrogel colloids, Au nanoparticles, and iron oxide magnetic particles. Since the process does not require surface modification of the colloids, it can be used to fabricate any colloidal patterns.
Synthesis and Characterization of Red‐Emitting Iridium(III) Complexes for Solution‐Processable Phosphorescent Organic Light‐Emitting Diodes
Authors: Lee Seung‐Joon , Park Jin‐Su , Song Myungkwan , Shin In Ae , Kim Young‐Inn , Lee Jae Wook , Kang Jae‐Wook , Gal Yeong‐Soon , Kang Sunwoo , Lee Jin Yong , Jung Sung‐Hyun , Kim Hyung‐Sun , Chae Mi‐Young , Jin Sung‐Ho
Published: June 2009

A new series of highly efficient red‐emitting phosphorescent Ir(III) complexes, (Et‐CVz‐PhQ)2Ir(pic‐N‐O), (Et‐CVz‐PhQ)2Ir(pic), (Et‐CVz‐PhQ)2Ir(acac), (EO‐CVz‐PhQ)2Ir(pic‐N‐O), (EO‐CVz‐PhQ)2Ir(pic), and (EO‐CVz‐PhQ)2Ir(acac), based on carbazole (CVz)‐phenylquinoline (PhQ) main ligands and picolinic acid N‐oxide (pic‐N‐O), picolinic acid (pic), and acetylacetone (acac) ancillary ligands, are synthesized for phosphorescent organic light‐emitting diodes (PhOLEDs), and their photophysical, electrochemical, and electroluminescent (EL) properties are investigated. All of the Ir(III) complexes have high thermal stability and emit an intense red light with an excellent color purity at CIE coordinates of (0.65,0.34). Remarkably, high‐performance solution‐processable PhOLEDs were fabricated using Ir(III) complexes with a pic‐N‐O ancillary ligand with a maximum external quantum efficiency (5.53%) and luminance efficiency (8.89 cd A−1). The novel use of pic‐N‐O ancillary ligand in the synthesis of phosphorescent materials is reported. The performance of PhOLEDs using these Ir(III) complexes correlates well with the results of density functional theory calculations.
Soft‐sensor development using correlation‐based just‐in‐time modeling
Authors: Fujiwara Koichi , Kano Manabu , Hasebe Shinji , Takinami Akitoshi
Published: June 2009

Soft‐sensors have been widely used for estimating product quality or other key variables, but their estimation performance deteriorate when the process characteristics change. To cope with such changes, recursive PLS and Just‐In‐Time (JIT) modeling have been developed. However, recursive PLS does not always function well when process characteristics change abruptly and JIT modeling does not always achieve the high‐estimation performance. In the present work, a new method for constructing soft‐sensors based on a JIT modeling technique is proposed. In the proposed method, referred to as correlation‐based JIT modeling (CoJIT), the samples used for local modeling are selected on the basis of the correlation among measured variables and the model can adapt to changes in process characteristics. The usefulness of the proposed method is demonstrated through a case study of a CSTR process, in which catalyst deactivation and recovery are taken into account. In addition, its industrial application to a cracked gasoline fractionator is reported. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Clinical study of two brothers with a novel 33 bp duplication in the ARX gene
Authors: Demos Michelle K. , Fullston Tod , Partington Michael W. , Gécz Jozef , Gibson William T.
Published: June 2009

Pathogenic variations of the ARX (aristaless‐related homeobox) gene are associated with marked phenotypic pleiotropy. These phenotypes are X‐linked neurological disorders that include brain and genital malformation and non‐malformation syndromes. Typically, malformation phenotypes result from pathogenic variations that are predicted to truncate the ARX protein, or alter residues in the highly conserved homeodomain. While non‐malformation phenotypes tend to be caused by pathogenic variations that are predicted to expand the first two polyalanine tracts of ARX, or alter residues outside of the homeodomain. The most common pathogenic variation of the ARX gene is a duplication of 24 bp, c.429_452 dup, which leads to an expansion of the second polyalanine tract of the ARX protein from 12 to 20 alanine residues. This pathogenic variation is associated with both sporadic and familial nonsyndromic mental retardation. Syndromic manifestations include mental retardation with hand dystonia (Partington syndrome), infantile spasms (West syndrome) and/or other epileptic seizures. Here, we report on a novel pathogenic variant of a tandem 33 bp duplication that is predicted to result in an expansion of polyalanine tract 2 in two brothers with mental retardation, epilepsy, dystonia, and the novel feature of intermittent hyperventilation. This pathogenic variation is predicted to result in a “non‐homogeneous” polyalanine tract expansion that is longer than predicted expansion caused by the common 24 bp duplication. The location of the novel 33 bp duplication in the same region as the common 24 bp duplication supports this region as the ARX variation “hot spot.” © 2009 Wiley‐Liss, Inc.
The unique value of primate models in translational research
Authors: Shively Carol A. , Clarkson Thomas B.
Published: June 2009

This special issue of AJP is focused on research using nonhuman primates as models to further the understanding of women's health. Nonhuman primates play a unique role in translational science by bridging the gap between basic and clinical investigations. The use of nonhuman primates in biomedical research challenges our resolve to treat all life as sacred. The scientific community has responded by developing ethical guidelines for the care and the use of primates and clarifying the responsibility of investigators to insure the physical and psychological well‐being of nonhuman primates used in research. Preclinical investigations often involve the use of animal models. Rodent models have been the mainstay of biomedical science and have provided enormous insight into the workings of many mammalian systems that h ave proved applicable to human biological systems. Rodent models are dissimilar to primates in numerous ways, which may limit the generalizability to human biological systems. These limitations are much less likely in nonhuman primates and in Old World primates, in particular, Macaques are useful models for investigations involving the reproductive system, bioenergetics, obesity and diabetes, cardiovascular health, central nervous system function, cognitive and social behavior, the musculoskeletal system, and diseases of aging. This issue considers primate models of polycystic ovary syndrome; diet effects on glycemic control, breast and endometrium; estrogen, reproductive life stage and atherosclerosis; estrogen and diet effects on inflammation in atherogenesis; the neuroprotective effects of estrogen therapy; social stress and visceral obesity; and sex differences in the role of social status in atherogenesis. Unmet research needs in women's health include the use of diets in nonhuman primate studies that are similar to those consumed by human beings, primate models of natural menopause, dementia, hypertension, colon cancer, and frailty in old age, and dedicated colonies for the study of breast cancer. Am. J. Primatol. 71:715–721, 2009. © 2009 Wiley‐Liss, Inc.
Investigations on esterification reactions of starches in 1‐N‐butyl‐3‐methylimidazolium chloride and resulting substituent distribution
Authors: Lehmann André , Volkert Bert
Published: June 2009

The ionic liquid (IL) 1‐N‐butyl‐3‐methylimidazolium chloride ([C4mim]+Cl−) was used as solvent for different esterification reactions of the biopolymer starch. Therefore, maize starches with varying content of amylose were used. Different carboxylic acid anhydrides were applied to esterify starch with a degree of substitution (DS) in the range of 0.7–3.0. For example, starch acetates with the mentioned DS are accessible within 30 min at a 105°C‐reaction temperature. The DS distribution of starch acetates synthesized in IL was compared with the common starch acetate synthesis of Mark and Mehltretter. Also, a consideration of starch acetates and cellulose acetates synthesized in [C4mim]+Cl− is given. The starch esters were characterized by means of Raman spectroscopy for qualitative‐ and nuclear magnetic resonance spectroscopy for quantitative determination of the functionalization pattern. Moreover, the molecular mass distribution was determined after saponification by means of GPC‐MALLS. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation of acrylic acid grafted polypropylene nonwoven fabric by photoinduced graft polymerization with preabsorption of monomer solution
Authors: Na Choon‐Ki , Park Hyun‐Ju
Published: June 2009

We improved photoinduced graft polymerization by absorbing the monomer solution onto the substrate (Ab‐type) instead of immersing the substrate in the monomer solution (Im‐type) before photoirradiation to yield a more practical and effective grafting system. With this system, acrylic acid (AA) was effectively grafted onto polypropylene (PP) nonwoven fabric. The maximum degree of grafting obtainable was restricted by the amount of monomer preabsorbed onto the PP fabric. However, we effectively enhanced the degree of grafting by increasing the monomer concentration, adding trimethylolpropane triacrylate (TMPTA) to the monomer solution, and repeating the photoirradiation with supplementation of the monomer solution. The net availability of the monomer for graft polymerization was 50% or greater; this increased to 90% or greater with the addition of TMPTA and was much higher than for conventional Im‐type photografting (≤13%). Fourier transform infrared spectra, scanning electron microscopy morphology observations, and the adsorption–regeneration properties confirmed that the PP‐g‐AA fabric prepared by the improved Ab‐type photografting method had comparable qualities to those of fabric prepared by conventional Im‐type photografting. Thus, the improved Ab‐type photografting system provides potential for the preparation of graft adsorbents on a large scale at a competitive cost with a continuous reactor, such as a conveyer belt system, instead of a batch reactor. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The role of the interface in melt linear viscoelastic properties of LLDPE/LDPE blends: Effect of the molecular architecture of the matrix
Authors: Robledo Nuria , Vega Juan F. , Nieto Jesús , Martínez‐Salazar Javier
Published: June 2009

The rheological properties of blends consisting of a long chain branched low‐density polyethylene (LDPE) and two linear low‐density polyethylenes (LLDPE) are studied in detail. The weight fractions of the LDPE used in the blends are 5 and 15%. The linear viscoelastic characterization is performed at different temperatures for all the blends to check thermorheological behavior and miscibility in the melt state. Blends containing metallocene LLDPE as the matrix display thermorheologically complex behavior and show evidences of immiscibility in the melt state. The linear viscoelastic response exhibits the typical additional relaxation ascribed to the form deformation mechanism of dispersed phase droplets (LDPE). The Palierne model satisfactorily describes the behavior of these blends in the whole frequency range explored. However, those blends with Ziegler‐Natta LLDPE as the matrix fulfill the time‐temperature superposition, but exhibit a broad linear viscoelastic response, further than the expected for an immiscible system with a sharp interface. The rheological analysis reveals that, in addition to the droplets form relaxation, another mechanism at lower frequencies exists. The broad linear response of the blends with the Ziegler‐Natta LLDPE can be explained by hypothesizing a strong interaction between the high molecular weight linear fraction of the LLDPE and the low molecular weight (almost linear) chains of the LDPE phase, forming a thick interface with its own viscoelastic properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Magnetite‐loaded calcium‐alginate (MLCA) particles as potential sorbent for removal of Ni(II) from aqueous solution
Authors: Bajpai Sunil Kumar , Armo Mukesh Kumar
Published: June 2009

This work is focused on the removal of Ni(II) from aqueous solutions by sorption onto newly developed magnetite‐loaded calcium alginate particles. The uptake of Ni(II) by these magnetite particles, with their mean geometrical diameter 84 and 508 μm, is best described by the Freundlich isotherm and the constantsKFand 1/n were found to be 3.491 mg g−1, 0.731 and 0.793 mg g−1and 0.907, respectively. The mean sorption energy, as determined by Dubinin‐Radushkevich isotherm for 508‐ and 84‐μm sized particles was evaluated to be 8.9 and 8.0 kJ mol−1, respectively, thus, suggesting the ion‐exchange mechanism for uptake process. Of the various kinetic models proposed, the kinetic Ni(II)‐uptake data were best interpreted by “Simple Elovich” and “Power function” as suggested by their higher regression values. The almost linear nature of plots of log(% sorption) versus log(time) was indicative of intraparticle diffusion. The values of intraparticle diffusion coefficientsKidwere found to be 63.49 × 10−2and 94.35 × 10−2mg l−1min0.5. The intraparticle diffusion was also confirmed by Bangham equation. Finally, various thermodynamic parameters were evaluated. The negative ΔG° indicated spontaneous nature of uptake process while positive ΔH° value suggested exothermic nature of the sorption process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Characterization and emulsifying properties of block copolymers prepared from lactic acid and poly(ethylene glycol)
Authors: Siao Syuan‐Yi , Lin Li‐Hsiu , Chen Wei‐Wen , Huang Ming‐Hsi , Chong Pele
Published: June 2009

Block copolymers were prepared by the direct polycondensation of an aqueous lactic acid solution on monomethoxy or dihydroxyl poly(ethylene glycol) (PEG) in the absence of a catalyst. The resulting poly(lactic acid) (PLA)–PEG diblock and PLA–PEG–PLA triblock copolymers were characterized by various analytical techniques, including matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF MS), gel permeation chromatography, and 1H‐NMR. The molecular structure between PLA–PEG and PLA–PEG–PLA could be distinguished after the calculation of the repeat unit masses and end‐group masses through the MALDI‐TOF MS spectra. Interestingly, both copolymers could serve as a hydrophilic emulsifier to stabilize the squalene/water interfaces and yield narrowly distributed oil‐in‐water nanoparticles. In contrast, the prepolymer PEG failed to stabilize the squalene/water interface under the same homogenization conditions. These features are of great interest for applications as bioactive agent delivery, especially for candidate vaccine antigens and lipophilic anticancer drugs. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electrosprayed polymer particles: Effect of the solvent properties
Authors: Park Chul Ho , Lee Jonghwi
Published: June 2009

Electrospraying technology has been studied in many fields to produce particles of various substances from nanoscale to microscale sizes. Unlike pure liquids, droplets formed by electrospraying that are comprised of polymer solutions undergo additional solidification processes involving solvent evaporation, which primarily determine the particle size and morphology. Herein, the effects of the solvent properties on the morphology and dimensions of solidified particles were systematically studied. In general, the size of the solidified spherical particles with smooth surfaces reflected that of the initially formed liquid droplets, which could partially be estimated by theoretical equations developed for pure liquids. Particle sizes increased with an increase in polymer content and a decrease in the boiling point of the volatile solvent. Inhomogeneous drying processes related to phase separation or skin formation resulted in hollow, cuplike, and porous particle structures, with particle sizes and morphologies that were outside of the scope of the theoretical treatments. The selection of a proper solvent or solvent mixture seemed to be a convenient way to control the particle morphologies, such as hollow, cuplike, or porous structures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
From a laboratory to a pilot scale production of natural rubber grafted with PMMA
Authors: Kalkornsurapranee Ekwipoo , Sahakaro Kannika , Kaesaman Azizon , Nakason Charoen
Published: June 2009

Graft copolymers of natural rubber and poly (methyl methacrylate) (NR‐g‐PMMA) were prepared in a laboratory scale, and then extended to a pilot scale production. Reaction conditions were first assessed based on a preparation in the laboratory scale with a reactor capacity of 1.5 l. An optimum grafting efficiency was obtained when cumene hydroperoxide/tetraethylenepentamine (CHP/TEPA) redox initiator was used at the reaction temperature and time of 50°C and 3 h, respectively. MMA monomer was used without purification in the polymerization process comparing with the purified one by means of extraction. It was found that only a slight decrease of grafting efficiency was observed when the nonpurified monomer was used in the reaction. The nonpurified monomer was therefore used to prepare the NR‐g‐PMMA in a pilot scale production with a reactor capacity of 260 L. Various weight ratios of NR/MMA at 50/50, 60/40, 70/30, and 85/15 were studied. The resulting graft copolymers were characterized by FTIR and 1H‐NMR techniques. It was found that increasing concentration of MMA caused an increase of free PMMA (i.e., homopolymer) but a decrease of free NR (i.e., ungrafted NR) and grafting efficiency. Quantity of grafted PMMA on the NR backbone was estimated using the integrated peak areas of 1H‐NMR spectra and quantitative analysis by extraction method. The results were found to be in good agreement. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Photocrosslinking of halogen‐free flame‐retarded ethylene‐vinyl acetate copolymer by phosphorous‐nitrogen compound NP28
Authors: Wu Qianghua , Qu Baojun , Sun Mei
Published: June 2009

The photoinitiated crosslinking of halogen‐free flame‐retarded ethylene‐vinyl acetate copolymer (EVA) by the phosphorous‐nitrogen compound NP28 in the presence of photoinitiator and crosslinker and characterization of the related properties have been investigated by gel determination, heat extension test, thermogravimetric analysis (TGA), mechanical measurement, and thermal aging test. The photocrosslinking efficiency of EVA/NP28 blend and various factors affecting the crosslinking process, such as photoinitiator, crosslinker, NP28 content, and irradiation temperature, were studied in detail and optimized by comparison of gel content. The results show that the EVA/NP28 blend filled with 28.2 wt % NP28 with a thickness of 1.6 mm is homogeneously photocrosslinked to a gel content of above 80 wt % with 4.8 s UV‐irradiation under optimum conditions. The data from TGA, mechanical measurement, and thermal aging test give evidence that the thermal stability and mechanical properties of photocrosslinked EVA/NP28 blend are much better than those of the unphotocrosslinked one.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Radiation synthesis of poly(N‐vinylpyrrolidone‐co‐methacrylic acid) hydrogels and their usability in uranyl ion adsorption
Authors: Şolpan Dilek , Torun Murat
Published: June 2009

In this study, N‐vinylpyrrolidone(VP)/methacrylic acid (MAA) mixtures have been prepared at three different mole percents which the methacrylic acid composition around 5, 10, and 15%. Poly(N‐vinylpyrrolidone‐co‐methacrylicacid) P(VP/MAA) hydrogels irradiated at 3.4 kGy have been used for swelling and diffusion studies in water and uranyl ion solutions. The influence of dose, pH, relative amounts of monomers in MAA/VP monomer mixtures on the swelling properties have been investigated. P(VP/MAA) hydrogels were swollen in distilled water at pH 7.0. P(VP/MAA)1 hydrogel containing 36% (mole percent) methacrylic acid showed the maximum percent swelling in water. Adsorption isotherms were constructed for uranyl ions and P(VP/MAA) hydrogel systems. It has been found that P(VP/MAA) hydrogels have very high uptake of the uranyl ions succesfully in water containing uranyl ions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009