bluuebunny/crossref_metadata_2025 huggingface dataset:
Endoscopic image-guided odontoidectomy for decompression of basilar invagination via a standard anterior cervical approach
Authors: Wolinsky Jean-Paul , Sciubba Daniel M. , Suk Ian , Gokaslan Ziya L.
Published: January 2008

✓Symptomatic irreducible basilar invagination has traditionally been approached through a transoral–transpharyngeal route with resection of the anterior portion of C-1 and the odontoid. Modification of this exposure with either a Le Fort osteotomy or a transmandibular osteotomy and circumglossal approach has increased the access to pathological conditions in this region. These traditional routes all require traversing the oral cavity and accepting the associated potential complications. The authors have developed a novel surgical approach, an endoscopic transcervical odontoidectomy, which allows access for resection of the odontoid and for brainstem and spinal cord decompression without traversing the oral cavity. In this paper they describe the technique and its advantages and present three cases in which patients underwent the endoscopic transcervical odontoidectomy for basilar invagination.

Three consecutive patients (age range 42–74 years) who had irreducible basilar invagination underwent the endoscopic transcervical odontoidectomy. All were symptomatic and had neck pain and myelopathy. All were evaluated preoperatively and postoperatively with computed tomography and magnetic resonance imaging. In all cases the procedure resulted in complete decompression. There were no serious complications. No patient required prolonged intubation, tracheostomy, or enteral tube feeding. One patient had an intraoperative cerebrospinal fluid leak, which had no postoperative sequelae.

The authors present an alternative surgical approach for treating ventral compression of the brainstem and spinal cord. The technique is safe and effective for decompression and provides a surgical route that can be added to the armamentarium of treatments for pathological conditions in this region.
Working area, safety zones, and angles of approach for posterior C-1 lateral mass screw placement: a quantitative anatomical and morphometric evaluation
Authors: Rocha Rogerio , Safavi-Abbasi Sam , Reis Cassius , Theodore Nicholas , Bambakidis Nicholas , De Oliveira Evandro , Sonntag Volker K. H. , Crawford Neil R.
Published: January 2008

Object

The authors measured relevant quantitative anatomical parameters to define safety zones for the placement of C-1 posterior screws.

Methods

Nineteen linear, two angular, and four surface parameters of 20 dried atlantal specimens were evaluated. The Optotrak 3020 system was used to define the working area. Ideal angles for screw positioning were measured using digital radiographs and a free image-processing program. Six silicone-injected cadaveric heads were dissected bilaterally to study related neurovascular anatomy.

The depth (range 5.2–9.4 mm, mean 7.2 ± 1.1 mm) and width (range 5.2–8.1 mm, mean 6.5 ± 0.9 mm) of the transverse foramen varied considerably among specimens. The mean posterior working area was 43.3 mm2. All specimens accommodated 3.5-mm-diameter screws, and 93% accepted 4-mm-diameter screws. In 10 specimens (50%), partial removal of the posterior arch was necessary to accommodate a 4-mm screw. The mean maximum angle of medialization was 16.7 ± 1.3°; the mean maximum superior angulation was 21.7 ± 4.7°.

Conclusions

The anatomical configuration of the atlas and vertebral artery (VA) varied considerably among the cadaveric specimens. The heights of the C-1 pedicle, posterior arch, and posterior lamina determine the posterior working area available for screw placement. The inferior insertion of the posterior arch may have to be drilled to increase this working area, but doing so risks injury to the VA. A dense venous plexus with multiple anastomoses may cover the screw entry site, potentially obscuring the operative view and increasing the risk of hemorrhage.
Fatal cerebral and cerebellar hemorrhagic infarction after thoracoscopic microdiscectomy
Authors: Cornips Erwin M. J. , Staals Julie , Stavast Angela , Rijkers Kim , Van Oostenbrugge Robert J.
Published: January 2008

✓ The authors present a rare case of fatal cerebral and cerebellar hemorrhagic infarction following an uneventful thoracoscopic microdiscectomy. They hypothesize that this complication was associated with cortical venous thrombosis secondary to intracranial hypotension, which was caused by an unnoticed leak of cerebrospinal fluid (CSF) into the thoracic cavity. Cortical venous thrombosis and intrathoracic CSF were confirmed at autopsy. The former disorder is the most severe manifestation of the pathophysiological mechanism occurring to a lesser degree in patients affected by mild intracranial hypotension, and occurs more frequently in these patients. Intracranial hypotension (of an orthostatic nature or not) must be considered in the differential diagnosis of every patient who complains of headaches after thoracoscopic or open transthoracic microdiscectomy.
Inadvertent intrathecal vincristine administration: a neurosurgical emergency
Authors: Qweider Maher , Gilsbach Joachim M. , Rohde Veit
Published: January 2008

✓ Vincristine has a high neurotoxicity level. If given intrathecally by accident, it can cause ascending radiculomyeloencephalopathy, which is almost always fatal. The authors report a rare case in which vincristine was accidentally injected intrathecally into a 32-year-old man. The patient, who had Burkitt lymphoma, was neurologically intact, and it is likely that his survival was made possible due to aggressive neurosurgical therapy. After immediate cerebrospinal fluid (CSF) aspiration, external ventricular and lumbar drains were placed for CSF irrigation, which was continued for 6 days. This CSF irrigation was combined with 1) the intrathecal administration of fresh-frozen plasma to bind the vincristine and 2) an intravenous antineurotoxic therapy involving pyridoxine, folic acid, and glutamic acid. The patient's first sensorimotor deficits occurred after 2 days, led to an incomplete sensorimotor dysfunction below T-9 within the next 17 days, but progressed no further. Supported by the scarce data culled from the reviewed literature, the authors hypothesize that prolonged CSF irrigation combined with antineurotoxic therapy contributed to the patient's satisfactory outcome. In conclusion, accidental intrathecal vincristine injection requires emergency and adequate neurosurgical therapy.
Neurophysiological detection of iatrogenic C-5 nerve deficit during anterior cervical spinal surgery
Authors: Bose Bikash , Sestokas Anthony K. , Schwartz Daniel M.
Published: January 2008

Object

The incidence of postoperative C-5 spinal nerve root palsy following decompressive cervical spinal surgery has been reported to be as high as 12% for anterior procedures and 30% for posterior procedures. The present study was conducted to document the prevalence of iatrogenic C-5 nerve root deficit during anterior cervical spinal surgery, as well as to evaluate the sensitivity and specificity of intraoperative transcranial electrical stimulation (TES)–induced motor evoked potentials (MEPs) and spontaneous electromyographic (EMG) activity for identifying evolving C-5 nerve root impairment.

Methods

The authors conducted a retrospective study of 238 consecutive anterior cervical spinal procedures performed by a single surgeon at Christiana Care Hospital within a 48-month period. Techniques used to monitor spinal nerve root function included TES-induced MEPs and spontaneous EMG activity from deltoid, biceps, triceps, wrist extensor, and hand intrinsic muscles innervated by the C5–T1 spinal nerve roots. Spinal cord function was monitored by recording TES-induced MEPs from upper- and lower-extremity muscles as well as somatosensory evoked potentials from stimulation of the ulnar and posterior tibial nerves.

Conclusions

Transcranial electrical stimulation–induced MEPs and spontaneous EMG activity offer complementary information about evolving iatrogenic C-5 spinal nerve root impairment during anterior cervical spinal surgery. The TES-induced MEPs provide prognostic information and show increased sensitivity to C-5 deficit compared with spontaneous EMG activity alone. Monitoring of spinal nerve root function using only EMG activity carries a risk of false-negative findings; without timely warning of impending neurological impairment, timely intervention to prevent permanent deficit cannot occur.
Postlaminoplasty cervical range of motion: early results
Authors: Kang Suk-Hyung , Rhim Seung-Chul , Roh Sung-Woo , Jeon Sang-Ryong , Baek Hyun-Chul
Published: January 2008

Object

The authors studied cervical range of motion (ROM) before and after cervical laminoplasty to determine factors associated with cervical ROM in patients with cervical myelopathy.

Methods

Between July 2003 and August 2005, 20 patients underwent a modified Hirabayashi-type unilateral open-door laminoplasty to treat multilevel cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL). Clinically, the authors assessed Japanese Orthopaedic Association (JOA) score, duration of symptoms, disease entity, and the age and sex of patients to ascertain the relation of these factors to ROM before and after cervical laminoplasty. Intraoperative findings such as ligament detachment from the C-2 spinous process and cervicothoracic junction involvement were noted. Radiological and imaging findings such as the length of the lesion, cervical axial canal area, antero-posterior (AP) diameter of the cervical canal, angle of the opened lamina after surgery, cervical sagittal angles, cervical curvature index (CCI), and signal change of the cord on magnetic resonance imaging were evaluated.

The mean follow-up period was 19.45 months (range 13–38 months). The preoperative average ROM in 18 patients (after excluding two patients with trauma) was 36.73 ± 15.73°; postoperatively it was 25.24 ± 16.06°. Thus, ROM decreased by 9.64 ± 10.09° (31.80%) after surgery (p = 0.002), reflecting the mean in the same 18 patients. Preoperative ROM was related to the age of patients, CCI, preoperative JOA score, and AP diameter of the cervical canal. In cases of OPLL the ROM was lower than that in cases of spondylosis. Postoperative cervical ROM was related to preoperative ROM, postoperative AP diameter of the cervical canal, laminar angle, patient age, and follow-up duration. None of the studied parameters, however, correlated with a decreased cervical ROM.

Conclusions

Cervical ROM was reduced after cervical laminoplasty. Postlaminoplasty cervical ROM had a positive correlation with extended motion; however, gradually it became reduced. In this study, no correlative factor was associated with a reduction in cervical ROM. Further study is also needed.
Negative-pressure wound therapy in the treatment of complex postoperative spinal wound infections: complications and lessons learned using vacuum-assisted closure
Authors: Jones G. Alexander , Butler John , Lieberman Isador , Schlenk Richard
Published: January 2008

Object

Deep infections of the spine are a significant cause of morbidity and death. Such infections complicate 0.7 to 11.9% of spinal procedures. Management includes intravenous antibiotic therapy, debridement and irrigation with primary closure, placement of drains, use of irrigation systems, and/or healing through secondary intention with wound packing. Vacuum-assisted closure (VAC) is a new alternative for treatment of patients with complex postoperative spinal infections. The aim of this study was to investigate the safety of this treatment method in this patient population.

Methods

The authors reviewed the charts of 16 consecutive patients treated with negative-pressure wound therapy at their institution between 2002 and 2006. All had deep infections of the spine and were treated with surgical debridement and placement of VAC dressings. All infections were postoperative. Members of the infectious disease service were involved in the care of all patients, and all patients received intravenous antibiotic therapy. The authors reviewed operative notes, discharge summaries, and notes from follow-up visits and assessed outcome on the basis of the same records.

Three patients were lost to follow up, leaving a group of 13 with follow up of at least 90 days. Two patients experienced bleeding complications related to the continuous negative pressure of the VAC device. In two cases, the infections persisted and required reoperation. In one case, a skin graft was required because of nonhealing granulation tissue. One of the patients with bleeding complications died as a result of delayed complications related to intraoperative blood loss, blood loss via the VAC system, and refusal of a blood transfusion on religious grounds.

Conclusions

Negative-pressure wound therapy has been employed as a treatment strategy for patients with complex postoperative spinal infections, but little is known of the complications associated with VAC in the spinal surgery patient population. Serious complications, including death, may be associated with use of the VAC system.
The expression of Fas ligand on normal and stabbed-disc cells in a rabbit model of intervertebral disc degeneration: a possible pathogenesis
Authors: Wang Jing , Tang Tiansi , Yang Huilin , Yao Xiaoshen , Chen Liang , Liu Wei , Li Tao
Published: January 2008

Object

The nucleus pulposus has been reported to be an immunologically privileged site. The expression of Fas ligand (FasL) on normal and herniated lumbar disc cells has been reported. The relationship between a physiological barrier and the role of FasL has not yet been addressed. To clarify this relationship and to investigate a possible pathogenesis of intervertebral disc degeneration (IDD), the expression of Fas and FasL (a mean apoptosis index) on normal and stabbed-disc cells was examined in a rabbit model of IDD.

Methods

Using defined needle gauges and depths, the anular puncture model of IDD was established in rabbits. The normal and stabbed discs were harvested at 3, 6, and 10 weeks after surgery. Immunohistochemical staining of these discs for Fas and FasL was performed using standard procedures. The mean apoptosis indices of the disc cells were determined using flow cytometry analysis.

The nucleus pulposus cells from the normal discs exhibited relatively weak immunopositivity, whereas the nucleus pulposus cells from the stabbed discs exhibited strong immunopositivity. There was a significant difference (p < 0.001) in the percentage of FasL-positive nucleus pulposus cells between the normal discs and the stabbed discs. The mean apoptosis indices of the stabbed-disc cells at 3, 6, and 10 weeks poststab were significantly higher than those in normal disc cells (p < 0.001, 0.002, and 0.006, respectively). There was a significant correlation between the degree of FasL-positive expression and the degree of Fas-positive expression of the nucleus pulposus cells poststab (r = 0.571, p = 0.0036).

Conclusions

These observations indicate that the nucleus pulposus is an immunologically privileged site. This immunological privilege is maintained by FasL and the physiological barrier together. When the physiological barrier was damaged (by stabbing the disc), the role of FasL changed, and FasL was coexpressed with Fas to induce apoptosis of disc cells. These results indicate that an autoimmune reaction may be a possible pathogenesis of IDD.
Evaluation of hydroxyapatite ceramic vertebral spacers with different porosities and their binding capability to the vertebral body: an experimental study in sheep
Authors: Ito Manabu , Kotani Yoshihisa , Hojo Yoshihiro , Abumi Kuniyoshi , Kadosawa Tsuyoshi , Minami Akio
Published: January 2008

Object

The aim of this study was to evaluate the degree of bone ingrowth and bonding stiffness at the surface of hydroxyapatite ceramic (HAC) spacers with different porosities in an animal model and to discuss the ideal porous characteristics of these spacers for anterior spinal reconstruction.

Methods

Twenty-one adult sheep (age 1–2 years, mean weight 70 kg) were used in this experiment. Surgery consisted of anterior lumbar interbody fusion at L2–3 and L4–5, insertion of an HAC spacer (10 × 13 × 24 mm) with three different porosities (0, 3, and 15%), and single-rod anterior instrumentation. At 4 and 6 months postoperatively, the lumbar spines were harvested. Bonding conditions at the bone–HAC spacer interface were evaluated using neuroimages and biomechanically. A histological evaluation was also conducted to examine the state of bone ingrowth at the surface of the HAC spacer.

Biomechanical testing showed that the bonding strength of HAC at 6 months postoperatively was 0.047 MPa in 0% porosity spacers, 0.39 MPa in 3%, and 0.49 MPa in 15% porosity spacers. The histological study showed that there was a soft-tissue layer at the surface of the HAC spacer with 0% porosity. Direct bonding was observed between bone and spacers with 3 or 15% porosity. Micro–computed tomography scans showed direct bonding between the bone and HAC with 3 or 15% porosity. No direct bonding was observed in HAC with 0% porosity.

Conclusions

Dense (0%) HAC anterior vertebral spacers did not achieve direct bonding to the bone in the sheep model. The HAC vertebral spacers with 3 or 15% porosity showed proof of direct bonding to the bone at 6 months postoperatively. The higher porosity HAC spacer showed better bonding stiffness to the bone.
Primary paraspinal leiomyosarcoma invading the cervical spinal canal successfully treated with surgery, radiotherapy, and chemotherapy
Authors: Lehman Norman L. , Jacobs Charlotte D. , Holsten Phillip A. , Jaikumar Sivakumar , Lehman Trang D. , Gibbs Iris C. , Shuer Lawrence M.
Published: January 2008

✓A primary paraspinal leiomyosarcoma invading the spine is an exceedingly rare neoplasm that may clinically mimic a schwannoma. The authors report a case involving a 45-year-old man with a primary leiomyosarcoma of the cervical paraspinal musculature that invaded the spinal canal at C1–2 and subsequently metastasized to the lungs and pancreas. Aggressive treatment consisting of resection of the primary tumor, adjunctive radiation therapy and chemotherapy, and surgical debulking of metastatic disease resulted in local tumor control at the primary site and long-term survival of the patient.
Convergence, Noninstrumental Value and the Semantics of ‘Love': Reply to Norton
Authors: Mcshane Katie
Published: January 2008

Bryan Norton argues that my recent critique of anthropocentrism presupposes J. Baird Callicott's philosophically problematic distinction between intrinsic and instrumental value and that the problems that it raises for anthropocentrism in general are in fact only problems for strong anthropocentrism. I argue, first, that my own view does not presuppose Callicott's distinction, nor any claims about instrumental value, and second, that the problems it raises for anthropocentrism apply to weak and strong anthropocentrism alike.
Synthetic Biology: Drawing a Line in Darwin's Sand
Authors: Preston Christopher J.
Published: January 2008

Maintaining the coherence of the distinction between nature and artefact has long been central to environmental thinking. By building genomes from scratch out of ‘bio-bricks', synthetic biology promises to create biotic artefacts markedly different from anything created thus far in biotechnology. These new biotic artefacts depart from a core principle of Darwinian natural selection – descent through modification – leaving them with no causal connection to historical evolutionary processes. This departure from the core principle of Darwinism presents a challenge to the normative foundation of a number of leading positions in environmental ethics. As a result, environmental ethicists with a commitment to the normative significance of the historical evolutionary process may see synthetic biology as a moral ‘line in the sand'.
The Multidimensionality of Environmental Problems: The GMO Controversy and the Limits of Scientific Materialism
Authors: Carolan Michael S.
Published: January 2008

This paper argues for a broader understanding of complexity; an understanding that speaks to the multidimensionality of environmental problems. As argued, environmental problems rest upon ontological, epistemological, and moral claims; they rest, in other words, upon statements about what is, knowledge, and what ought to be, respectively. To develop and illustrate this argument, the GMO (genetically modified organism) controversy is broken down according to these three dimensions. Dissecting environmental problems in this manner reveals why we cannot look solely toward the natural sciences for resolution: because these problems beg questions that cannot be answered with references to materiality alone.
Rethinking Nature: Public Visions in the Netherlands
Authors: Van Den Born Riyan J.G.
Published: January 2008

This study addresses two questions: (1) what visions of nature do lay people subscribe to? (2) to what extent do these visions reflect those of professional philosophers?

Four philosophical images of the human-nature relationship were discussed with respondents; Master, Steward, Partner and Participant. Respondents recognise these images, but prefer to construct their own. Elements of their images are (1) that humans are part of nature, but (2) that they are responsible for nature as well. This study indicates that empirical philosophy can contribute to the further development of environmental philosophy. Through an empirical turn we can discover people's own voice.
Engineering Miracles: Water Control, Conversion and the Creation of a Religious Landscape in the Medieval Ardennes
Authors: Arnold Ellen F.
Published: January 2008

Though sometimes at odds, the religious and economic identities of medieval monks could also reinforce one another. Benedictine monks throughout the medieval world engaged in the economic transformation of the world while also seeking to flee many kinds of secular involvement. In the early and high Middle Ages, the monks of the Ardennes actively worked to reconcile this by constructing a religious framework for their practical activities. They controlled, managed and engineered water resources, and created miracle stories that highlighted these activities. Medieval monks had cultural and religious reasons for creating stories about water control, and religious stories need a firmer place in discussions of environment and technology. This article demonstrates that monks were able to use their religious authority and their control of religious message to support and supplement their temporal powers. The control of water resources was more than an economic or practical necessity; it was deeply connected to monastic identity and the relationships between monks and the secular world.
Book Reviews
Authors: Widgren Mats , Goodall Heather , Pratt Stphen
Published: January 2008

Sing C. Chew, The Recurring Dark Ages: Ecological Stress, Climate Changes and System Transformation (MATS WIDGREN)
Amita Baviskar (ed.), Waterscapes (HEATHER GOODALL)
Sharon Beder, Environmental Principles and Policies: An Interdisciplinary Approach (STEPHEN PRATT)
Book Reviews
Authors: Rotherham Ian D. , Frawley Jodi , van Dam Petra J.E.M.
Published: January 2008

Peter Coates, Strangers on the Land: American Perceptions of Immigrant and Invasive Species (IAN D. ROTHERHAM)
S. Ravi Rajan, Modernizing Nature: Forestry and Imperial Eco-Development 1800-1950 (JODI FRAWLEY)
Marie Luisa Allemeyer, 'Kein Land ohne Deich...!' Lebenswelten einer Kuestengesellschaft in der Frühen Neuzeit (PETRA J.E.M. VAN DAM)
Fire Extinguishing Agents
Authors: Slye Orville M.
Published: January 2008

The article contains sections titled:1.Introduction2.Water as an Extinguishing Agent3.Fire‐Fighting Foams3.1.Limitations and Uses3.2.Foam Concentrates3.3.Guidelines for Using Fire‐Fighting Foams4.Dry Chemical Extinguishing Agents5.Inerting Gas Extinguishing Agents6.Halogenated Extinguishing Agents7.Direct Halon Replacement Agents and Systems8.Extinguishing Agents for Combustible Metal Fires
Phosphoric Acid and Phosphates
Authors: Schrödter Klaus , Bettermann Gerhard , Staffel Thomas , Wahl Friedrich , Klein Thomas , Hofmann Thomas
Published: January 2008

The article contains sections titled:

1.Monophosphoric Acid1.1.Properties1.2.Production1.2.1.Thermal Processes1.2.2.Wet Processes1.2.3.Concentration of Wet Phosphoric Acid1.2.4.Purification of Wet Phosphoric Acid1.3.Uses and Economic Aspects1.4.Environmental Aspects2.Condensed Phosphoric Acids3.Phosphates3.1.Sodium Monophosphates3.2.Condensed Sodium Phosphates3.2.1.Properties3.2.2.Metal Complexing by Phosphates3.2.2.1.Introduction3.2.2.2.Analytical Methods3.2.2.3.Complexing by Individual Phosphates3.2.2.4.Other Concepts Besides the Stability Constant3.2.3.Sodium Diphosphates3.2.4.Pentasodium Triphosphate3.2.5.Higher Condensed Sodium Polyphosphates3.2.6.Sodium Metaphosphates3.2.7.Uses of Condensed Sodium Phosphates3.3.Other Phosphates3.3.1.Potassium Phosphates3.3.2.Ammonium Phosphates3.3.3.Magnesium Phosphates3.3.4.Calcium Phosphates3.3.5.Boron Phosphate3.3.6.Aluminum Phosphates3.4.Economic Aspects4.Toxicology
Trace Analysis
Authors: Einax Jürgen W. , Kowalik Corinna
Published: January 2008

The article contains sections titled:

1Subject and Scope2Working Fields3Contamination and Decontamination4Quantitation of Trace‐Analytical Measurements and Their Quality Assurance4.1Basic Considerations4.2Uncertainty Concept4.3Calibration4.4Validation4.5Limit of Decision, Detection, and Determination4.6Analytical Quality Assurance5Sampling, Sample Preservation, and Sample Preparation5.1Sampling and Sample Preservation5.2Sample Preparation5.2.1General Aspects5.2.2Sample Preparation for Inorganic Trace Analysis5.2.3Sample Preparation for Organic Trace Analysis6Inorganic Trace Analysis6.1Introduction6.2Spectroscopic Methods6.2.1Atomic Absorption Spectroscopy (AAS)6.2.2Inductively Coupled Plasma Optical Emission Spectroscopy (ICP‐OES)6.2.3Inductively Coupled Plasma Mass Spectroscopy (ICP‐MS)6.2.4Comparison of AAS, ICP‐OES, and ICP‐MS6.2.5X‐ray Fluorescence Spectroscopy (XRF)6.3Electrochemical Analytical Methods6.3.1Potentiometry–Ion‐selective Electrodes (ISE)6.3.2Voltammetry/Polarography6.3.3Comparison of Electrochemical Analytical Methods6.4Neutron Activation Analysis (NAA)7Organic Trace Analysis7.1Introduction7.2Gas Chromatography (GC)7.3High Performance Liquid Chromatography (HPLC)8Other Techniques for Trace Analysis8.1Methods of Classical Chemical Analysis8.2Methods of the Determination of Group and Sum Parameters8.3Enzyme and Immunochemical Analysis9Examples of Trace Analysis9.1Analysis of Fresh Water for Trace Elements by ICP‐MS9.2Determination of Pt in Soil Samples by GFAAS9.3Determination of Polyaromatic Hydrocarbons by GC/MS9.4Analysis of Explosives by HPLC/UV10PerspectiveReferences
Electrochemical Reactors
Authors: Vogt Helmut , Kreysa Gerhard
Published: January 2008

The article contains sections titled:

1.Reactors with Gas‐Evolving Electrodes1.1.Effects of Gas Evolution on Cell Operation1.2.Bubble Nucleation, Growth, and Detachment1.3.Bubble Coverage1.4.Product Release1.5.Ohmic Resistance of the Interelectrode Gap1.6.Mass Transfer at Gas‐Evolving Electrodes1.7.Heat Transfer1.8.Overpotential of Gas‐Evolving Electrodes1.9.Limiting Current Density at Gas‐Evolving Electrodes1.10.Electrodes1.11.Gas‐Lift Systems2.Reactors with Superficial Electrodes3.Reactors with Three‐Dimensional Electrodes4.Special Reactor Designs

The operating modes of electrochemical reactors vary as widely as the designs of the reactors. This is determined not only by the chemical behavior of the different electrolytes, especially their corrosivity, but also by the very different products. These can be formed as solids, as in electrodeposition, in liquid form, as in the case of many substances that react further in the liquid phase, or as a gaseous phase, for example, in the electrolysis of water. Operating temperatures cover a wide range, from room temperature to 1000 °C. In most cases the electrolytes are liquid solutions or melts, but more recently also solids (e.g., solid polymer electrolytes) and in special cases gases, as in high‐temperature water electrolysis, or plasmas in glow‐discharge electrolysis. Accordingly, the materials and shapes of the electrodes also very diverse. The simplest electrodes are those with flat surfaces. Two such electrodes face each other a few millimeters apart in order to minimize the ohmic potential drop across the gap, or they are divided by a liquid‐permeable diaphragm or gas‐permeable membrane, which also separates the electrolyte chambers from one another. In many cases specially shaped electrodes are used that better meet the requirements of a process. Their influence on the design and operation of the reactors are the subject of this article. In particular, these are reactors with gas‐evolving electrodes and special reactor designs to meet specific requirements.
RNA
: Noncoding
Authors: Henry Allison A. , Vogel Jörg
Published: January 2008

After decades of being either underestimated as a simple messenger in the expression of proteins from deoxyribonucleic acid (DNA), or revered as the molecule from which all life potentially originated, ribonucleic acid (RNA) is at last enjoying a well‐deserved golden age as modern techniques allow researchers to uncover the myriad of subtle roles that this molecule plays in the cells of today. Noncoding RNAs, by definition, do not become translated into protein. This broad category includes cellular RNAs that range in size from 20 to 20,000 nucleotides, can contain chemical modifications, adopt a wide variety of secondary and tertiary structures, associate with proteins and other RNA molecules, and have physiological roles, in all organisms, that run the gamut from catalysis to regulating gene expression. As this article is intended to complement the other RNA‐related sections of this volume, a brief introduction to all types of noncoding RNA will be followed by a comprehensive discussion of three important categories: riboswitches, small RNAs in bacteria, and large RNAs in mammals. Riboswitches are
cis
‐acting RNA elements that modulate gene expression in a highly specialized manner by means of an aptamer domain, an RNA sequence that tightly and selectively binds a given metabolite. Small RNAs are 70–200 nucleotide molecules in bacteria that regulate gene expression, primarily at a posttranscriptional level. In mammalian cells, large RNAs of up to 19,000 nucleotides are essential to X‐chromosome inactivation and genomic imprinting.
Terminal Distribution
Authors: Pope Albert
Published: January 2008

Could the late 20th‐century rejection of Modernist planning, and along with it the notion of a ‘universal subject’, mean that urban designers and architects might have lost sight of who they are designing cities for? Albert Pope sets out on a search to define the contemporary ‘who’ and finds some answers in Michel Foucault's notion of the historically grounded subject. Copyright © 2008 John Wiley & Sons, Ltd.
Composite membrane based on ionic conductor and mixed conductor for oxygen permeation
Authors: Zhu Xuefeng , Yang Weishen
Published: January 2008

A composite membrane, which comprises of one fluorite oxide phase (Ce0.8Gd0.2O1.9) for oxygen ionic transport and one perovskite oxide phase (Gd0.2Sr0.8FeO3−δ) for both oxygen ionic and electronic transport, was investigated. XRD results revealed that the two oxides are compatible and showed good oxygen permeation stability at 950°C (more than 1100 h). Oxygen flux of the composite membrane was two times higher than that of the Gd0.2Sr0.8FeO3−δ mixed conducting membrane at the same conditions. At steady state, oxygen flux of a 0.5 mm membrane was 0.80 ml/(cm2 min) under oxygen partial pressure gradient of air/He and ∼5.0 ml/(cm2 min) for syngas production at 950°C, respectively. After ∼440 h operation under syngas conditions, SEM analysis revealed that the syngas side of the membrane still kept dense and the EDX showed the transfer of elements occurred in the depth of a few microns. © 2008 American Institute of Chemical Engineers AIChE J, 2008
Quality control chart method for analyzing PEF variability in occupational asthma
Authors: Hayati Fazel , Maghsoodloo Seed , DeVivo Michael J. , Thomas Robert E. , Lemiere Catherine
Published: January 2008

Background

Asthma is the most common occupational respiratory disorder in the industrialized world. In this research we investigated the effectiveness of quality control chart as a method to explore the work‐relatedness of asthma using peak expiratory flow (PEF) as the variable of interest.

Method

PEF measurements were recorded from several workers suspected of having occupational asthma. The measurements were recorded for a period of 2 weeks at work and two away from work. For each subject, average $({\bar X})$ quality control chart was developed and analyzed using Shewhart methods.

Results

Using the ratio of average daily PEF diurnal variation at work to the baseline average diurnal variation, quality control chart detected and characterized increased variation in PEF between the periods at workplace and away from workplace. This ratio was evaluated at 15% and 20% and compared to the results of the gold standard. A ratio of greater than 15% produced a sensitivity of 94% and specificity of 61%. These results are as good as and in some cases better than the previously published work.

Conclusions

Quality control chart is an effective and inexpensive method for early intervention to detect workers suspected for occupational asthma. Also, the findings in this article are an invitation for further research in occupational asthma using quality control chart methods for other indices of airways obstruction (FEV‐1, RAW) or inflammation (NO). Am. J. Ind. Med. 51:223–228, 2008. © 2008 Wiley‐Liss, Inc.
Serotonin transporter gene and adverse life events in adult ADHD
Authors: Müller Daniel J. , Mandelli Laura , Serretti Alessandro , DeYoung Colin G. , De Luca Vincenzo , Sicard Tricia , Tharmalingam Subi , Gallinat Jürgen , Muglia Pierandrea , De Ronchi Diana , Jain Umesh , Kennedy James L.
Published: January 2008

Childhood attention deficit hyperactivity disorder (ADHD) symptomatology persists in a substantial proportion of cases into adult life. ADHD is highly heritable but the etiology of ADHD is complex and heterogeneous, involving both genetic and non‐genetic factors. In the present article we analyzed the influence of both genetics and adverse life events on severity of ADHD symptoms in 110 adult ADHD patients. Subjects were genotyped for the norepinephrine transporter (NET), the catechol‐O‐methyltransferase (COMT), the serotonin transporter promoter polymorphism (SERTPR) and the more rare A/G variant within SERTPR. Three main outcomes were obtained: (1) adverse events showed a small but positive correlation with current ADHD severity; (2) NET, COMT and the A/G variant within SERTPR were not associated with ADHD severity; (3) taking into account stressors, the long (L) SERTPR variant showed a mild effect on ADHD, being associated with an increased severity, particularly as regard affective dysregulations; on the other hand, in subjects exposed to early stressors, it showed a protective effect, as compared to the short (S) variant. In conclusion, our data support the role of environmental factors in adult ADHD symptomatology. SERTPR may be involved in some features of the illness and act as a moderator of environmental influences in ADHD. © 2008 Wiley‐Liss, Inc.
Intergroup conflicts among chimpanzees in Taï National Park: lethal violence and the female perspective
Authors: Boesch Christophe , Crockford Catherine , Herbinger Ilka , Wittig Roman , Moebius Yasmin , Normand Emmanuelle
Published: January 2008

Intercommunity aggression in chimpanzees and primitive warfare in humans possess striking similarities, such as the common occurrence of large male coalitions, systematic control of territory boundaries, and lethal attacks on isolated individuals from neighboring groups. However, an important apparent contrast is the absence of recurrent peaceful interactions between neighboring groups of chimpanzees. We observed a remarkable range of behavior in intergroup encounters among three habituated communities of chimpanzees in Taï National Park, Côte d'Ivoire. Lethal attacks are documented in these study groups for the first time, as well as year‐long exchanges of parous adult females and peaceful intergroup visits of mothers with infants. Demographic factors, including group size and number of adult males, are shown to affect the nature of intergroup interactions in ways not considered previously. A reconsideration of the difference in intergroup interactions between eastern and western chimpanzees is proposed including a more important consideration of the female's perspective. The inclusion of the new complexities in intergroup interactions in chimpanzees allows new parallels to be drawn with the evolution of primitive warfare in humans. Am. J. Primatol. 70:519–532, 2008. © 2008 Wiley‐Liss, Inc.
Polyelectrolyte enhanced flocculation, particle interactions and dewaterability of fine gibbsite dispersions
Authors: Addai‐Mensah Jonas , Bal Heramb , Yeap Kai‐Ying
Published: January 2008

Enhanced dewaterability of colloidal hydrophilic mineral dispersions, via flocculation and gravity‐assisted thickening, remains an important and technically challenging issue. To develop the right customized approach for flocculant selection to improve dewaterability, the influence of eight polyacrylamide (PAM) copolymers on flocculation, particle interactions and dewatering behaviour of fine, 9.5 wt% gibbsite dispersions at pH 7.5, 9.5 and 11.5 at 22 °C is investigated. The results show that polymer charge type (anionic vs cationic) and charge density (5–45%) and molecular weight [(5–20) × 106 Da] had a striking, pH‐dependent impact on dewaterability and dispersion rheology. Depending upon polymer type and dosage (50–200 g t−1 solid) and pulp pH, good to extremely fast settling rates (14–200 m h−1) were obtained upon orthokinetic flocculation. Sediment solid loadings recorded also showed polymer structure‐ and pH‐dependency and were in the range 40–54 wt%. Upon shear of the pre‐sedimented pulps, a 6–10 wt% solid improvement in consolidation resulted. The polymer with lower charge density (5% anionic) and lower molecular weight [(5–10) × 106 Da] was more effective in producing enhanced dewaterability of charged and neutral gibbsite particles than the polymers with higher molecular weights and/or charges. The settling rate, sediment consolidation and particle interactions (rheology) correlated positively, where faster settling flocs displayed higher sediment yield stresses which were accompanied by greater compaction behaviour. The findings underscore the need for greater understanding of the interplay between pulp interfacial chemistry and flocculant characteristics for optimum dewaterability. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Synthesis and properties of novel organosoluble bismaleimides and polyaspartimides containing bis(4‐maleimido‐3, 5‐dimethyl phenyl) halo phenyl methane
Authors: Hariharan R. , Sarojadevi M.
Published: January 2008

A series of bismaleimides was synthesized from bis(4‐amino‐3, 5‐dimethylphenyl) (X) phenyl methane (X = 3′chloro, 3′‐bromo, 3′‐benzyloxy, 4′‐chloro, 4′‐fluoro) and maleic anhydride. The bismaleimides were subsequently polymerized with various diamines by Michael addition to yield novel polyaspartimides. All the polymers exhibited good solubility in organic solvents and the inherent viscosity of the polymers were in the range of 0.40–0.56 dL/g, which is good enough to fabricate composites and films. The temperature at which 10% weight loss occurred was in the range of 390–441°C. The polymers had high glass transition temperature in the range of 205–275°C and left about 31.95–84.20% char yield at 800°C indicating that they have good self‐extinguishing property. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and superswelling behavior of carboxymethylcellulose–poly(sodium acrylate‐co‐acrylamide) hydrogel
Authors: Sadeghi Mohammad , Hosseinzadeh Hossein
Published: January 2008

In this paper, attention is paid to synthesis and swelling behavior of a superabsorbent hydrogel based carboxymethylcellulose (CMC) and polyacrylonitrile (PAN). The physical mixture of CMC and PAN was hydrolyzed in NaOH solution to yield hydrogel, CMC–poly(NaAA‐co‐AAm). During alkaline hydrolysis, the nitrile groups of PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups followed by in situ crosslinking of the grafted PAN chains. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectroscopy. The reaction variables affecting the swelling capacity of the hydrogel were systematically optimized to achieve a hydrogel with swelling capacity as high as possible. Swelling measurements of the synthesized hydrogels in various chloride salt solutions indicated a swelling‐loss with increase in the ionic strength of the salt solutions. The pH of the various solutions also affected the swelling of the superabsorbent. Furthermore, the present hydrogels showed a pH‐reversible property. Finally, the swelling kinetics of synthesized hydrogels with various absorbent particle sizes was briefly examined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Rare earth compounds modified carbon black filled powdered natural rubber: Preparation, morphology and properties
Authors: Lin Yaling , Zhang Anqiang , Wang Lianshi
Published: January 2008

Ten types of rare earth (RE) compounds modified carbon black (HAF‐RE) were prepared using chemical‐deposit method, then HAF‐RE were mixed with natural rubber latex to prepare HAF‐RE filled powdered natural rubber [P(NR/HAF‐RE)] by a carbon black/rubber latex coagulation method. It is found that most of the P(NR/HAF‐RE) vulcanizates showed better mechanical properties, especially higher tensile modulus, and tensile strength, compared with none‐rare earth modified carbon black filled powdered natural rubber [P(NR/HAF)]. Dysprosium (Dy) modified carbon black (HAF‐Dy) filled powdered natural rubber [P(NR/HAF‐Dy)] was chosen for intensive investigation because of its better comprehensive mechanical properties. It is found that the adding of Dy compounds could help to get smaller particles with narrower particle size distribution, and results from the SEM analysis show that carbon black has been dispersed in rubber matrix uniformly with diameter of 50–150 nm. The TEM analysis showed that Dy compounds could obviously reduce the aggregation of primary particles of carbon black, and promote the dispersion of carbon black in P(NR/HAF‐Dy) particles. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci 2008
UV/heat dual‐curable adhesive tapes for fabricating stacked packages of semiconductors
Authors: Saiki Naoya , Yamazaki Osamu , Ebe Kazuyoshi
Published: January 2008

To facilitate the fabrication of a reliable stacked package for a semiconductor, UV/heat dual curing of adhesives was investigated. The formulated adhesives contained acrylic monomer and epoxy resins. First, UV curing was conducted on the acrylic monomer, followed by heat curing. It was found that UV‐curable acrylic monomers affected the adhesive's properties, e.g., adhesion, water absorption, and viscoelasticity. As the acrylic monomer, neopentylglycol diacrylate (NPGDA), trimethylolpropane triacrylate (TMPTA), dipentaerythritol hexaacrylate (DPHA), and tricyclodecanedimethanol acrylate (TCDDA) were used to investigate the effect of functional group numbers and structure. As a result, an acrylic monomer that has two functional groups with a rigid moiety (TCDDA) showed acceptable properties as adhesives for the fabrication, and thus a UV/heat‐curing adhesive has been successfully developed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of poly(acrylic acid‐co‐N‐[3‐(dimethylamino)propyl]‐methacrylamide) hydrogel membranes for biomedical applications
Authors: Das Anup , Ray Alok R.
Published: January 2008

A series of new hydrogel membranes with different compositions of acrylic acid (AAc) and N‐[3‐(dimethylamino)propyl]‐methacrylamide (DMAPMA) were prepared by aqueous copolymerization, without using chemical crosslinker or radiation. Chemical structure of the membranes (PADMAs) was characterized by Fourier transform infrared spectroscopy (FTIR). Swelling experiments were carried out in simulated body fluid (SBF) at 37 ± 1°C to investigate degree of swelling, dimensional stability, and pore size of the PADMA membranes. In SBF, the variation of pore size with membrane composition was monitored by optical microscopic technique. Morphology of the membranes was characterized, before and after exposure to SBF, by scanning electron microscopy (SEM). It was observed that the membranes are composed of closely packed nanogels of ∼200 nm. Macroporous network structure of the SBF‐swollen PADMA was also observed to be composed of interconnected nanogels. Blood compatibility of the PADMA membranes was evaluated in vitro, by performing hemolysis assay and thrombogenicity assay. The extent of hemolysis due to PADMA membranes was found to be <2%, which ensured that all of the membranes were highly hemocompatible. Salicylic acid (SA) was chosen as a model drug. Diffusion coefficient of SA through PADMA membranes was investigated. It was observed that membrane composition regulates both pore size and drug diffusion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of preoxidation and carbonization technologies on tensile strength of PAN‐based carbon fiber
Authors: Jing Min , Wang Cheng‐Guo , Zhu Bo , Wang Yan‐Xiang , Gao Xue‐Ping , Chen Wei‐Ning
Published: January 2008

Dependence of the tensile strength of resulting carbon fiber (CF) on the preparation technologies during preoxidation and carbonization were studied systematically by a series of pilot experiments. The proper preoxidation time, preoxidation temperature, and preoxidation stretching ratio are the base of preparing high‐quality CF. During precarbonization, the enhancement of the precarbonization temperature and the application of the precarbonization stretching are helpful to increase the tensile strength of CF, but the stretching ratio should be controlled carefully by on‐line tension values. The tensile strength of CF increases quickly below 1200°C and then slowly above 1200°C as the carbonization temperature raises. Even though during carbonization, a proper relaxation should also be explored in order to prepare optimal CF. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008