bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanistic aspects of biosynthesis of silver nanoparticles by several Fusarium oxysporum strains
Authors: Durán Nelson , Marcato Priscyla D , Alves Oswaldo L , De Souza Gabriel IH , Esposito Elisa
Published: July 2005

Extracellular production of metal nanoparticles by several strains of the fungus Fusarium oxysporum was carried out. It was found that aqueous silver ions when exposed to several Fusarium oxysporum strains are reduced in solution, thereby leading to the formation of silver hydrosol. The silver nanoparticles were in the range of 20–50 nm in dimensions. The reduction of the metal ions occurs by a nitrate-dependent reductase and a shuttle quinone extracellular process. The potentialities of this nanotechnological design based in fugal biosynthesis of nanoparticles for several technical applications are important, including their high potential as antibacterial material.
Assessment of the health of Americans: the average health-related quality of life and its inequality across individuals and groups
Authors: Asada Yukiko
Published: July 2005

Background

The assessment of population health has traditionally relied on the population's average health measured by mortality related indicators. Researchers have increasingly recognized the importance of including information on health inequality and health-related quality of life (HRQL) in the assessment of population health. The objective of this study is to assess the health of Americans in the 1990s by describing the average HRQL and its inequality across individuals and groups.

Methods

This study uses the 1990 and 1995 National Health Interview Survey from the United States. The measure of HRQL is the Health and Activity Limitation Index (HALex). The measure of health inequality across individuals is the Gini coefficient. This study provides confidence intervals (CI) for the Gini coefficient by a bootstrap method. To describe health inequality by group, this study decomposes the overall Gini coefficient into the between-group, within-group, and overlap Gini coefficient using race (White, Black, and other) as an example. This study looks at how much contribution the overlap Gini coefficient makes to the overall Gini coefficient, in addition to the absolute mean differences between groups.

Results

The average HALex was the same in 1990 (0.87, 95% CI: 0.87, 0.88) and 1995 (0.87, 95% CI: 0.86, 0.87). The Gini coefficient for the HALex distribution across individuals was greater in 1995 (0.097, 95% CI: 0.096, 0.099) than 1990 (0.092, 95% CI: 0.091, 0.094). Differences in the average HALex between all racial groups were the same in 1995 as 1990. The contribution of the overlap to the overall Gini coefficient was greater in 1995 than in 1990 by 2.4%. In both years, inequality between racial groups accounted only for 4–5% of overall inequality.

Conclusion

The average HRQL of Americans was the same in 1990 and 1995, but inequality in HRQL across individuals was greater in 1995 than 1990. Inequality in HRQL by race was smaller in 1995 than 1990 because race had smaller effect on the way health was distributed in 1995 than 1990. Analysis of the average HRQL and its inequality provides information on the health of a population invisible in the traditional analysis of population health.
Use of a novel cell-based fusion reporter assay to explore the host range of human respiratory syncytial virus F protein
Authors: Branigan Patrick J , Liu Changbao , Day Nicole D , Gutshall Lester L , Sarisky Robert T , Del Vecchio Alfred M
Published: July 2005

Human respiratory syncytial virus (HRSV) is an important respiratory pathogen primarily affecting infants, young children, transplant recipients and the elderly. The F protein is the only virion envelope protein necessary and sufficient for virus replication and fusion of the viral envelope membrane with the target host cell. During natural infection, HRSV replication is limited to respiratory epithelial cells with disseminated infection rarely, if ever, occurring even in immunocompromised patients. However, in vitro infection of multiple human and non-human cell types other than those of pulmonary tract origin has been reported. To better define host cell surface molecules that mediate viral entry and dissect the factors controlling permissivity for HRSV, we explored the host range of HRSV F protein mediated fusion. Using a novel recombinant reporter gene based fusion assay, HRSV F protein was shown to mediate fusion with cells derived from a wide range of vertebrate species including human, feline, equine, canine, bat, rodent, avian, porcine and even amphibian (Xenopus). That finding was extended using a recombinant HRSV engineered to express green fluorescent protein (GFP), to confirm that viral mRNA expression is limited in several cell types. These findings suggest that HRSV F protein interacts with either highly conserved host cell surface molecules or can use multiple mechanisms to enter cells, and that the primary determinants of HRSV host range are at steps post-entry.
Microsurgical Anatomic Features of the Olfactory Nerve: Relevance to Olfaction Preservation in the Pterional Approach
Authors: Cardali Salvatore , Romano Alberto , Angileri Filippo Flavio , Conti Alfredo , La Torre Domenico , de Divitiis Oreste , d'Avella Domenico , Tschabitscher Manfred , Tomasello Francesco
Published: July 2005

OBJECTIVE:

The pterional approach represents the standard approach for most lesions of the anterior and middle cranial fossa. It requires some degree of frontal lobe retraction, which may result in temporary or permanent damage of olfaction because of nerve avulsion or mechanical compression. The purpose of this study, based on microanatomic dissection of human cadaveric specimens, was to review the microsurgical anatomic features of the nerve and suggest operative nuances that may contribute to reducing the rate of postoperative olfactory dysfunction.

METHODS:

Twenty olfactory nerves and tracts were examined in 10 human cadaveric heads obtained from three fresh and seven formalin-fixed adult cadavers. A standard pterional craniotomy was performed. The olfactory nerve was dissected from its arachnoidal envelopes and then mobilized for an average length of 30 mm (range, 25–35 mm).

RESULTS:

The possible retraction of the frontal lobe was 10 to 15 mm. More retraction invariably resulted in nerve disruption.

CONCLUSION:

The standard sylvian and basal cistern opening may be insufficient to guarantee preservation of olfactory function. Early identification and arachnoidal dissection of the nerve may reduce the rate of olfaction compromise. The opening of the subarachnoidal space should be performed in a proximal-to-distal manner to allow early visualization of the olfactory bulb and its dissection. The arachnoidal dissection should be performed with sharp instruments, avoiding any traction on the posterior portion of the olfactory tract. Any direct retractor compression should also be avoided to spare the microvasculature lying on the dorsal surface of the nerve.
Vascular Anatomy of the Anteriorly Based Pericranial Flap
Authors: Yoshioka Nobutaka , Rhoton Albert L.
Published: July 2005

OBJECTIVE:

The purpose of this study was to examine the vascular supply of the anteriorly based frontal pericranial flap to determine whether separating the pericranium from the galea above the orbital rim would devascularize the pericranial flap.

METHODS:

The arteries supplying and the veins draining the frontal pericranial flap were examined in 17 adult cadavers using ×3 to ×30 magnification. The arteries were examined on 25 sides and the veins on 16 sides.

RESULTS:

The main trunk and superficial branches of the supraorbital and supratrochlear arteries, which course in the galea-frontalis muscle layer, give rise to the deep branches that supply the pericranium. These pericranial branches may arise in the orbit or at the level of or above the orbital rim. Pericranial arteries that arose above the level of the orbital rim and would be divided in separating the galea and pericranium were found in 28% of the sides examined. Pericranial veins that coursed above the orbital rim and would be divided in separating the galea-frontalis muscle layer from the pericranial layer were found in 43.8% of the sides examined.

CONCLUSION:

In preparing a pericranial flap based anteriorly on the supraorbital rim, the separation of the galea-frontalis muscle layer from the pericranium layer should not extend into the 10 mm above the supraorbital rim if the arterial and venous pedicle of the pericranial flap is to be preserved.
Cerebral Cavernous Malformations Associated with Venous Anomalies: Surgical Considerations
Authors: Wurm Gabriele , Schnizer Mathilde , Fellner Franz A.
Published: July 2005

OBJECTIVE:

Once thought to be rare entities, mixed cerebrovascular malformations with pathological features of more than one type of malformation within the same lesion are now being recognized with increasing frequency. Their identification generates several hypotheses about common pathogenesis or causation-evolution among different types of lesions and leads to controversial discussion on therapeutic strategies.

METHODS:

Fifteen patients drawn from a consecutive series of 58 patients harboring cavernous malformations (25.9%) were found to have an associated venous malformation (VM). Three (33.3%) of the first 9 patients, in whom the large draining vein of the VM had been left untouched at previous interventions, developed recurrent and/or de novo lesions.

RESULTS:

Histopathological analysis, interestingly, revealed that the new lesions were different in nature (three arteriovenous angiomas in two patients, a capillary telangiectasia in one patient). During extirpation of the new malformation, the draining vein of the VM in these three patients could be coagulated without any adverse events. Coagulation and dissection of the draining vein of the associated VM was performed in six more patients of our series, and this has prevented development of new lesions up to now.

CONCLUSION:

Our results are in favor of the hypothesis that the draining vein of a VM is the actual underlying abnormality of mixed vascular malformations. Causing flow disturbances and having the potential for hemorrhages, the VM seems to promote the development of new adjacent malformations. Thus, permanent cure of associated malformations might depend on the surgical treatment of the VM. We present a preliminary personal series and a thorough review of the literature.
Functional Monitoring for Visual Pathway Using Real-time Visual Evoked Potentials and Optic-radiation Tractography
Authors: Kamada Kyousuke , Todo Tomoki , Morita Akio , Masutani Yoshitaka , Aoki Shigeki , Ino Kenji , Kawai Kensuke , Kirino Takaaki
Published: July 2005

OBJECTIVE:

It has been difficult to obtain anatomic and functional information about the visual pathway during neurosurgical operations. The aim of this study was to combine the information of the visual evoked potentials (VEPs) and the anatomic navigation of the optic radiation by diffusion tensor imaging-based tractography for functional monitoring of the visual pathway.

METHODS:

The subjects were two patients with brain lesions adjacent to the visual pathway. Diffusion tensor imaging-based tractography of the optic radiation was performed by selecting appropriate regions of interest and by fractional anisotropy. During surgery, cortical VEPs were recorded continuously under general anesthesia with sevoflurane. In Patient 2, the results of optic radiation tractography were imported to a neuronavigation system to better understand the spatial relationships between the lesions and the visual pathway (functional neuronavigation).

RESULTS:

In Patient 1, the lesion did not seem to be attached to the optic radiation, and VEP profiles remained stable during resection. In Patient 2, who had a lesion adjacent to the posterior horn of the lateral ventricle, VEPs suddenly diminished when resection reached the optic radiation as illustrated on the neuronavigation system. As a result, complete left hemianopia developed after surgery in Patient 2.

CONCLUSION:

We confirmed functional correlations of the results of diffusion tensor imaging-based tractography by monitoring intraoperative VEPs. The combination of continuous VEP and optic-radiation tractography is reliable to monitor the visual function and is helpful in performing neurosurgical planning near the visual pathway.
Integration of [11C]Methionine-Positron Emission Tomographic and Magnetic Resonance Imaging for Image-guided Surgical Resection of Infiltrative Low-grade Brain Tumors in Children
Authors: Pirotte Benoit , Goldman Serge , Van Bogaert Patrick , David Philippe , Wikler David , Rorive Sandrine , Brotchi Jacques , Levivier Marc
Published: July 2005

OBJECTIVE:

To evaluate the interest of integrating positron emission tomography (PET) images with the radiolabeled tracer [11C]methionine (Met) into the image-guided navigation planning of infiltrative low-grade brain tumors (LGBTs) in children.

METHODS:

Twenty-two children underwent combined Met-PET with magnetic resonance imaging (MRI) scans in the planning of a navigation procedure. These children presented an LGBT (astrocytomas, 10; oligodendrogliomas, 4; ependymomas, 4; gangliogliomas, 4) located close to functional areas. Tumor boundaries were ill-defined on MRI (including T2-weighted and fluid-attenuated inversion-recovery scans) and could not be clearly identified for allowing a complete, or at least a large, image-guided resection. The PET tracer Met was chosen because of its higher sensitivity and specificity than MRI to detect tumor tissue. The level and extension of MET uptake were analyzed to define the PET contour, subsequently projected onto MRI scans to define a final target contour for volumetric resection. The quality of tumor resection was assessed by an early postoperative MRI and Met-PET workup.

RESULTS:

In 20 of the 22 children with ill-defined LGBTs, PET improved tumor delineation and contributed to define a final target contour different from that obtained with MRI alone. Met-PET guidance allowed a total resection of Met uptake in 17 cases that were considered total tumor resections because the operative margin left in place contained nontumor tissue.

CONCLUSION:

These data suggested that Met-PET guidance could help to improve the number of total resections and the amount of tumor removed in infiltrative LGBTs in children.
Surgical Resection of Intrinsic Insular Tumors
Authors: Hentschel Stephen J. , Lang Frederick F.
Published: July 2005

THIS REPORT, WITH an accompanying videotape, details the authors' technique for performing radical resections of tumors intrinsic to the insular lobe. The resection technique takes advantage of the fact that many intrinsic insular tumors grow within the confines of the insula, usually without violating pial borders or invading the medial structures. The method described is based on an anatomic dissection of the insula that uses the internal boundaries of the region, particularly the peri-insular sulci, as guides for resection. The videotape provides a visual description of this method.
Local Delivery of Ibuprofen via Controlled-release Polymers Prevents Angiographic Vasospasm in a Monkey Model of Subarachnoid Hemorrhage
Authors: Pradilla Gustavo , Thai Quoc-Anh , Legnani Federico G. , Clatterbuck Richard E. , Gailloud Philippe , Murphy Kieran P. , Tamargo Rafael J.
Published: July 2005

OBJECTIVE:

Adhesion and migration of leukocytes into the periadventitial space play a role in the pathophysiology of vasospasm after subarachnoid hemorrhage (SAH). Intercellular adhesion molecule-1 is a determinant cell adhesion molecule involved in this process. Ibuprofen has been shown to inhibit intercellular adhesion molecule-1 upregulation and prevent vasospasm in animal models of SAH. In this study, we report the toxicity and efficacy of locally delivered ibuprofen incorporated into controlled-release polymers to prevent vasospasm in a monkey model of SAH.

METHODS:

Ibuprofen was incorporated into ethylene-vinyl acetate (EVAc) polymers at 45% loading (wt:wt). For the toxicity study, cynomolgus monkeys (n = 5) underwent surgical implantation of either blank/EVAc polymers (n = 3) or 45% ibuprofen/EVAc polymers (n = 2) in the subarachnoid space, were followed up for 13 weeks, and were killed for histopathological analysis. For the efficacy study, cynomolgus monkeys (n = 14) underwent cerebral angiography 7 days before and 7 days after surgery and SAH and were randomized to receive either a 45% ibuprofen/EVAc polymer (n = 7; mean dose of ibuprofen, 6 mg/kg) or blank EVAc polymers (n = 7) in the subarachnoid space. Angiographic vasospasm was determined by digital image analysis. Student's t test was used for analysis.

RESULTS:

Animals implanted with ibuprofen polymers showed no signs of local or systemic toxicity. Animals treated with ibuprofen polymers had 91 ± 9% lumen patency of the middle cerebral artery, compared with 53 ± 11% of animals treated with blank/EVAc polymers (P < 0.001).

CONCLUSION:

Ibuprofen polymers are safe and prevent angiographic vasospasm after SAH in the monkey model. These findings support the role of cell adhesion molecules and inflammation in the pathophysiology of vasospasm.
Sole Stenting Bypass for the Treatment of Vertebral Artery Aneurysms: Technical Case Report
Authors: Zenteno Marco A. , Murillo-Bonilla Luis M. , Guinto Gerardo , Gomez Camilo R. , Martinez Sergio R. , Higuera-Calleja Jesus , Lee Angel , Gomez-Llata Sergio
Published: July 2005

OBJECTIVE AND IMPORTANCE:

Vertebrobasilar aneurysms have a risk of rupture ranging from 2.5 to 50% (especially those larger than 7 mm) and a repeat bleeding rate of between 30 and 70%. For this reason, patients with aneurysms larger than 7 mm should be treated. Considering the high complexity of surgical approaches in this area, an increasing number of reported cases are being treated with endovascular therapy. The purpose of this article is to determine the effectiveness and safety of sole stenting bypass in the treatment of three consecutive patients with vertebrobasilar aneurysms.

CLINICAL PRESENTATION:

Three patients (one woman and two men) with vertebrobasilar junction aneurysms were included in this study. Two of the patients presented with subarachnoid hemorrhage.

INTERVENTION:

An endovascular procedure was performed under general (two patients) or local (one patient) anesthesia and via a right femoral approach. By use of road map guidance, sole Express (one patient) or Express 2 (two patients) coronary stents (Boston Scientific/Scimed, Maple Grove, MN) were deployed on the diseased vessel. When the stent was in place, an immediate partial thrombosis of the aneurysm was observed, related primarily to an intra-aneurysmal flow pattern modification, possibly facilitated by modification of the angle of the parent vessel. Follow-up angiograms showed complete exclusion of the aneurysms within the circulation. Only one patient presented visual deficit as a thrombotic complication, but it disappeared completely 6 months after treatment.

CONCLUSION:

The sole stenting bypass technique seems to be a good alternative for the treatment of complex vertebral aneurysms by inducing thrombosis of the aneurysm with preservation of the parent vessel lumen.
The Expanded Endonasal Approach: A Fully Endoscopic Transnasal Approach and Resection of the Odontoid Process: Technical Case Report
Authors: Kassam Amin B. , Snyderman Carl , Gardner Paul , Carrau Ricardo , Spiro Richard
Published: July 2005

THE TRANSORAL APPROACH to the odontoid process is considered the “gold standard” for resection of extradural lesions at this location. A completely transnasal endoscopic approach is feasible based on anatomic studies and our experience with the expanded endonasal approach for neoplasms of the cranial base. An illustrative case is presented to demonstrate the technical details of a fully transnasal completely endoscopic approach for the resection of the odontoid process. A 73-year-old woman with a long-standing history of rheumatoid arthritis presented with progressive cervicomedullary compression. Complete resection of the odontoid was achieved with no significant morbidity. This is the first reported case of a completely endoscopic resection of the odontoid using a fully transnasal route. The report demonstrates the feasibility of this approach and larger clinical series with long-term follow-up will be needed to determine the reproducibility and validation of any potential benefits.
Use of Ultrasonic Aspiration for Dural Opening in Cranial Reoperations: Technical Note
Authors: Galarza Marcelo , Sood Sandeep , Pomata Hugo B.
Published: July 2005

OBJECTIVE:

Dural detachment from the brain in cranial reoperations has been accomplished previously by selective coagulation and the cutting of brain-dural adhesions. The results of ultrasonic aspiration during tumor surgery or brain cutting procedures led the authors to speculate that the detachment of the dura mater from brain tumors by applying the Cavitron ultrasonic surgical aspirator (Valleylab, Boulder, CO [formerly Cavitron, Inc., Stamford, CT]) to the brain-dura mater interface could be used to reduce bleeding and facilitate dural opening during cranial reoperations.

METHODS:

Ten patients underwent a second craniotomy for epilepsy surgery (five cases of extended temporal lobectomy and five cases of extended extratemporal lesionectomy). The use of ultrasonic aspiration and its effects on brain separation from the dura mater were examined.

RESULTS:

Intraoperative use of the Cavitron ultrasonic surgical aspirator during dural opening produced immediate blanching of the dura mater and enhanced visualization of the cortical surface without distortion of the brain anatomy.

CONCLUSION:

Incremental dural opening and brain visualization is achieved by careful application of ultrasonic aspiration directly into the brain-dura limit, producing immediate regional dural devascularization. Use of this technique reduces cortical and dural bleeding and enhances the ease and effectiveness of brain visualization.
Use of a Novel Absorbable Hydrogel for Augmentation of Dural Repair: Results of a Preliminary Clinical Study
Authors: Boogaarts Jeroen D. , Grotenhuis J. André , Bartels Ronald H.M.A. , Beems Tjemme
Published: July 2005

OBJECTIVE:

To evaluate the safety and performance of a synthetic dural sealant as an adjunct to standard surgical dural repair techniques to prevent cerebrospinal fluid (CSF) leakage.

METHODS:

This study was designed as a prospective, nonrandomized, single-center clinical trial. The dural sealant is a synthetic absorbable hydrogel. Consecutive series of patients scheduled for elective cranial and intradural spinal surgery were included until a total of 50 applications were achieved. It was used primarily as an adjunct to ensure watertight dural closure. The end point was defined as no leak with the Valsalva maneuver after dural sealant application. The patients were followed up for 3 months after surgery to check for CSF leakage, standard laboratory and neurological examinations, and possible adverse advents.

RESULTS:

Of the 49 patients, 46 were included and treated with the dural sealant because of spontaneous leak (n = 34; 69%) or leak after the Valsalva maneuver (n = 12; 25%). There was no leak in the other patients (n = 3; 6%). After application of the dural sealant, there was no leak in all 46 patients (100%). Of the 46 patients included, there was one case of overt CSF leak. One patient had a pseudomeningocele. There were no adverse events other than those related to the disease or to the surgical procedure itself.

CONCLUSION:

The dural sealant, a synthetic absorbable hydrogel, is a useful adjunct to achieve watertight dural closure. Application resulted in 100% closure of intraoperative CSF leaks. There are no evident adverse effects.
Decreased origin usage and initiation of DNA replication in haploinsufficient HCT116 Ku80+/- cells
Authors: Sibani Sahar , Price Gerald B. , Zannis-Hadjopoulos Maria
Published: July 2005

One of the functions of the abundant heterodimeric nuclear protein, Ku (Ku70/Ku80), is its involvement in the initiation of DNA replication through its ability to bind to chromosomal replication origins in a sequence-specific and cell cycle dependent manner. Here, using HCT116 Ku80+/- cells, the effect of Ku80 deficiency on cell cycle progression and origin activation was examined. Western blot analyses revealed a 75% and 36% decrease in the nuclear expression of Ku80 and Ku70, respectively. This was concomitant with a 33% and 40% decrease in chromatin binding of both proteins, respectively. Cell cycle analysis of asynchronous and late G1 synchronized Ku80+/- cells revealed a prolonged G1 phase. Furthermore, these Ku-deficient cells had a 4.5-, 3.4- and 4.3-fold decrease in nascent strand DNA abundance at the lamin B2, β-globin and c-myc replication origins, respectively. Chromatin immunoprecipitation (ChIP) assays showed that the association of Ku80 with the lamin B2, β-globin and c-myc origins was decreased by 1.5-, 2.3- and 2.5-fold, respectively, whereas that of Ku70 was similarly decreased (by 2.1-, 1.5- and 1.7-fold, respectively) in Ku80+/- cells. The results indicate that a deficiency of Ku80 resulted in a prolonged G1 phase, as well as decreased Ku binding to and activation of origins of DNA replication.
Pharmaceutical Care in Community Pharmacies: Practice and Research from Around the World
Authors: Farris Karen B , Fernandez-Llimos Fernando , Benrimoj SI (Charlie)
Published: July 2005

Pharmaceutical care models and practices differ in various countries. Reimbursement for cognitive services, for example, varies across countries in Europe, Asia, and the Americas. Practice-based research has blossomed in many countries, with different emphases and challenges. This international series will describe the organization of community pharmacy within the healthcare system and report the status of practice-based research. Each paper will focus on one country. The series will conclude with a summary by the series editors describing the key themes across the papers, outlining milestones yet to be achieved, and proposing a research agenda for community pharmacy practice.
Capecitabine–Warfarin Interaction
Authors: Janney Laurel M , Waterbury Nancee V
Published: July 2005

OBJECTIVE:

To report a case of concomitant warfarin therapy with consecutive cycles of capecitabine therapy, providing time of onset, magnitude, and assessment of the interaction.

CASE SUMMARY:

A 59-year-old man receiving chronic warfarin therapy for a mechanical mitral valve replacement was diagnosed with stage IV metastatic colon cancer. He was started on capecitabine/irinotecan after his cancer progressed with fluorouracil/leucovorin and the FOLFOX 6 regimen (oxaliplatin, leucovorin, and continuous fluorouracil infusion). He received 3 consecutive cycles of capecitabine/irinotecan with concomitant oral anticoagulation and, with each cycle, the warfarin dose was reduced. Over the course of these 3 cycles, the total weekly dose of warfarin was reduced by >85%.

DISCUSSION:

The capecitabine–warfarin interaction is clinically significant, requiring a black box warning in the package insert. The mechanism of action for the interaction is not clear, but may be related to down-regulation of CYP2C9 by capecitabine or its metabolites or a pharmacodynamic interaction with warfarin. A common response to this interaction, as discussed in previously published case reports, is the discontinuation of warfarin, capecitabine, or both. In this case, the Naranjo probability scale indicates a highly probable drug interaction between warfarin and capecitabine.

CONCLUSIONS:

As more patients require anticoagulation, and as chemotherapy agents such as capecitabine become available, the likelihood for these drug interactions increases. In our patient, close monitoring of therapy allowed successful use of warfarin and capecitabine.
A Deconvolution Technique for Determining the Intrinsic Fluorescence Decay Lifetimes of Crude Oils
Authors: Quinn M. F. , Joubian S. , Al-Bahrani F. , Al-Aruri S. , Alameddine Oussama
Published: July 2005

A simple deconvolution procedure using FT was developed for determining the average lifetime of samples excited by a nitrogen laser pumped dye laser operating at 428 nm. To overcome the noise limitations imposed by including higher frequency harmonics in the analysis, we used an alternative approach. This approach relied on taking the Fourier transform at 21 subharmonic frequencies and using an appropriate weighting procedure in the calculation of amplitude and lifetime of the sample impulse response. A single exponential decay was assumed.
Acetic Acid Adsorbed on Copper Oxide Studied by Double Modulation Fourier Transform Infrared Reflection Absorption Spectroscopy
Authors: Sakata Yoshihisa , Domen Kazunari , Maruya Ken-Ichi , Onishi Takaharu
Published: July 2005

Acetic acid adsorbed to form the acetate ion on an oxygen preadsorbed copper polycrystalline surface was studied by the use of DM FT-IRAS in the presence or the absence of the vapor phase.
Phase-Resolved Subnanosecond Spectroscopy Using the Beat Frequencies from Mode-Locked Lasers
Authors: Wirth M. J. , Chou Shiow-Hwa
Published: July 2005

It is shown that the beat frequencies inherent to a mode-locked dye laser can be used in phase fluorometry. The fluorescence lifetime of cresyl violet, quenched by KI, is determined with the use of the first two harmonics of a synchronously pumped dye laser. The results from the two frequency components are in excellent agreement. The fluorescence lifetime is determined by time-resolved spectroscopy, with the use of the same sample and photomultiplier. The data show that narrower confidence intervals are obtained in the phase-resolved measurement, and this result is attributed to the high phase stability of a cw mode-locked laser.
Relation of the Acute Pulmonary Response to Cotton Dust and Dust Compositional Analysis by Near-Infrared Reflectance Spectroscopy. Part II: Unsieved Dust
Authors: Montalvo Joseph G. , Faught Sherman E. , Buco Steven M.
Published: July 2005

The near-infrared reflectance spectroscopy (NIRS) method of analysis, as applied to cotton dust, offers an independent method for searching for byssinosis causatives. We report here a test of the hypothesis that the acute pulmonary response from subjects exposed to cotton dust is a linear function of the composition of unsieved dust as measured by near-infrared reflectance spectroscopy (NIRS). A linear relationship was found between delta FEV1 (the forced expiratory volume in 1 second) and unsieved cotton dust captured by the Hi-Vol dust sampler. Of the various agents proposed over the years as the byssinosis causative agent, at least three of them (gram-negative bacteria and their endotoxins, and tannins) were present in the unsieved dust at concentrations exceeding the NIRS sensitivity level and may account for the observed relationship. No association was found between the pulmonary effects and cotton compositional analysis by NIRS. NIR reflectance spectra of cotton and cotton dust, in air and in nonabsorbing carbon tetrachloride, reveal similar absorption bands of different intensity.
Performance of a Gas Chromatographic-Matrix Isolation-Fourier Transform Infrared Spectrometer
Authors: Holloway Thomas T. , Fairless Billy J. , Freidline Charles E. , Kimball Harry E. , Kloepfer Robert D. , Wurrey Charles J. , Jonooby Laleh A. , Palmer Harold G.
Published: July 2005

The unique matrix-isolated (MI) Fourier transform infrared spectra of diethyl ether, propanal, and trifluoromethane are compared with their vapor-phase spectra. The marked increase in resolution seen in the MI spectra is accompanied by substantial frequency shifts from the peaks in the vapor-phase spectra. The spectra were generated with a gas chromatographic/matrix isolation/Fourier transform infrared spectrometer, with the use of frozen Ar at 13 K as the isolating matrix. The spectra of the 22 isomers of tetrachlorodibenzo- p-dioxin show that each isomer can be distinguished and quantitated at the nanogram level. In addition, preliminary quantitative data were obtained for the pesticides Terbufos® and Fonofos®. Finally, a problem with a previously published spectrum of C-13 2,3,7,8-tetrachlorodibenzo- p-dioxin was uncovered, and it was shown that the spectrum was actually that of C-13 2,3,7-trichlorodibenzo- p-dioxin.
Examinations of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part VIII
Authors: Coleman W. M. , Gordon Bert M.
Published: July 2005

Matrix isolation Fourier transform infrared (MI/FT-IR) data has been presented that documents the presence of discrete conformers in an argon matrix for a series of ketones. The distribution of conformers in the matrix was related to the structure of the molecule, in that rigid structures (i.e., small rings, bicyclic systems, and unsaturated systems) displayed simple carbonyl absorption patterns relative to those of their less rigid counterparts. Also, conformer isolation was seen for halosubstituted ketones. These results are in agreement with previous findings concerning the vapor-phase (VP) spectra of these molecules.
System for Simultaneous Determination of As, Sb, and Se by Hydride Generation and Inductively Coupled Plasma Optical Emission Spectrometry
Authors: Pyen Grace S. , Browner Richard F.
Published: July 2005

A simple three-channel system for simultaneous determination of As, Se, and Sb by hydride generation and ICP emission spectrometry is described. The device is based on the use of simple, low-resolution prism monochromators for spectral line isolation, together with interference filters for general background reduction. Detection limits are found to be 1.0 μg/L, 1.3 μg/L, and 2.4 μg/L, respectively, for As, Se, and Sb. Interference studies show no significant problems for a large number of elements. Use of the method for the analysis of Standard Reference Water Samples showed generally good agreement with round-robin data.
Ultratrace Determination of Metals with Dithizone by Thermal Lens Spectrophotometry
Authors: Ramos G. Ramis , Alvarez-Coque M. C. Garcia , Smith B. W. , Omenetto N. , Winefordner J. D.
Published: July 2005

A pump-probe thermal lens instrument was constructed, evaluated, and applied to the determination of metals after extraction with dithizone in carbon tetrachloride. An argon-ion laser operated at 514.5 nm, with a power of just 22 mW at the cuvette position and chopped at 2 Hz, and a He-Ne laser were used as a pump and probe, respectively. The thermal lens effect was measured by a pinhole-photodiode and a lock-in amplifier. Evaluation of the setup with an iodine solution in carbon tetrachloride gave a minimum detectable absorbance of 5 × 10−6 (S/N = 3), the upper limit of the dynamic range being 5.7 × 10−3. Relative standard deviation was about 3%. Calibration curves and limits of detection for several metal dithizonates were obtained. From extractions of cadmium dithizonate at concentrations lower than 2 ng mL−1, a LOD of 8 pg mL−1, corresponding to an absolute LOD of 4 fg of cadmium in the probe volume, was achieved.
Laser-Induced Double Resonance Ionic Fluorescence of Rare Earths in the Inductively Coupled Plasma
Authors: Tremblay M. E. , Simeonsson J. B. , Smith B. W. , Winefordner J. D.
Published: July 2005

Laser excitation of ionic fluorescence overcomes the problem of spectral interferences encountered when trace analysis of the rare earths is performed by atomic/ionic emission spectrometry in the inductively coupled plasma. Two pulsed, excimer pumped, tunable dye lasers are used to excite ionic fluorescence of rare earths in an inductively coupled plasma. Since several fluorescence lines have been observed after laser excitation, it is possible to draw partial energy level diagrams for lanthanum, ytterbium, europium, and lutetium. Detection limits, linear dynamic ranges, and sensitivities are also reported. This is the first time that two-step excited fluorescence has been observed for any rare earths in an inductively coupled plasma.
Partial Least-Squares Quantitative Analysis of Infrared Spectroscopic Data. Part I: Algorithm Implementation
Authors: Fuller M. P. , Ritter G. L. , Draper C. S.
Published: July 2005

Various approaches to infrared multicomponent quantitative analysis including K-matrix, multivariate least-squares, principal component regression (PCR), and partial least-squares (PLS) are compared. The advantages and disadvantages of each are discussed. A particular implementation of the PLS method is detailed, with emphasis on the methods provided for calibration optimization and evaluation.
Characterization of Peat Samples by Diffuse Reflectance FT-IR Spectroscopy
Authors: Holmgren Allan , Nordén Bo
Published: July 2005

A Fourier transform infrared spectroscopic study of Sphagnum peat, Carex peat, and mixtures of these peat types is reported. Intensity values from selected wavenumber regions of the infrared spectra were correlated with calorific value, degree of decomposition, carbon, and nitrogen content, and content of amino acids and amino sugars, with the use of the method of partial least-squares modelling with latent variables (PLS). The application of this method is shown to give valuable information about properties of peat which have no easily measured quantitative relationship to the infrared spectrum.
A New Dual-Channel Frequency-Domain Fluorometer for the Determination of Picosecond Rotational Correlation Times
Authors: Bright Frank V. , Monnig Curtis A. , Hieftje Gary M.
Published: July 2005

A new dual-channel multifrequency fluorometer is described which employs a mode-locked argon-ion laser as a polarized excitation source. The laser produces high-frequency sinusoidal intensity modulations in the MHz to GHz regime which are used to simultaneously probe the fluorescent molecules. The resulting orthogonally polarized components of the emission are collected by two opposite matched detection channels. Because both the parallel [ I∥(ω)] and perpendicular [ I⊥(ω)] components of the emission are collected simultaneously and at all modulation frequencies, information about the molecules' rotational rate can be rapidly deduced. With the new instrument, rotational correlation times as short as 15 ps can be routinely determined with data-acquisition times as short as 10 ms. Commonly, however, we employ collection times of several seconds to permit the averaging of between 100 and 500 scans. Examples which demonstrate the utility of the new instrument include the determination of the rotational correlation times for rhodamine 6G, fluorescein, and rubrene as a function of solvent viscosity. In addition, results are presented for the resolution of rhodamine 6G associated with beta-cyclodextrin. In the beta-cyclodextrin studies, little spectral (excitation/emission) or temporal (fluorescence lifetime) change was noted upon association. However, a significant difference exists between rotational correlation times of the free fluorophore and the fluorophore included by beta-cyclodextrin. This difference enables the formation constant for the association to be determined, a measurement which would be impossible with conventional techniques.
Vibrational Spectroscopic Analysis of Minoxidil (2,4-Diamino-6-Piperidinopyrimidine-3-Oxide) and Related Analogs
Authors: Chao R. S. , Thamann T. J. , Vail K. C.
Published: July 2005

Tentative vibrational assignments for 2,4-diamino-6-piperidinopyrimidine-3-oxide (minoxidil) between 4000 and 600 cm−1 have been made. Complementary infrared and Raman studies indicate that the two amino groups of minoxidil are not equivalent in the solid state. One of them is a free amino group, while the other is hydrogen bonded to the N-oxide. Vibrational spectroscopic analyses of minoxidil in different molecular environments, such as in polar solvents, aprotic solvents, and deuterium oxide, as well as in the pH = 1.5–12.5 range, have been performed to probe the structural variations generated by these conditions. Spectral comparison of minoxidil and its derivatives reveals that most spectral changes involve the amino and N-oxide functional groups. For instance, the N-oxide stretching vibration occurs at 1210 cm−1 in the solid state, but it shifts to 1193 cm−1 in polar solvents.

The amino hydrogens of minoxidil and desoxyminoxidil (2,4-diamino-6-piperidinopyrimidine) are readily exchanged with deuterium, as reflected in the ND2 stretching region (2600–2300 cm−1) in the infrared spectra of deuterated crystalline minoxidil and desoxyminoxidil. The similarity of band contours in the NH2 stretching region suggests that there are no structural alterations on deuteration for either minoxidil or desoxyminoxidil.
Design and Performance of an Optimized Dispersive Infrared Dichrograph
Authors: Diem M. , Roberts G. M. , Lee O. , Barlow A.
Published: July 2005

The design of a spectrometer for the observation of infrared vibrational circular dichroism (VCD) is reported. This instrument utilizes f/4 aperture, a minimum of optical elements, and a new electronic data acquisition method to improve the sensitivity of previous dispersive units. The instrument described exhibits a level of sensitivity comparable to that of present Fourier transform (FT) VCD instruments, while avoiding some problems which still persist in FT-VCD.
Triplet-State Kinetics of 2,5 Diphenyloxazole (PPO)
Authors: Dharamsi A. N. , Jong Shawpin
Published: July 2005

Time-resolved excited-state triplet-triplet absorption spectra were measured for solutions of 2,5 diphenyloxazole (PPO) in various solvents, with the use of a pump and probe technique. The rate constants for intersystem crossing, triplet deactivation by oxygen, and triplet-triplet self-quenching are obtained. The latter two rate constants are substantially larger than the corresponding rate constants for 2-(1 naphthyl)-5-phenyloxazole-αNPO.
Infrared Diffuse Reflectance Accessory for Local Analysis on Bulky Samples
Authors: Korte E. H. , Otto A.
Published: July 2005

A novel design of an accessory for diffuse reflectance spectroscopy in the infrared region is presented which allows in situ analysis of small surface areas (φ 3 mm) on bulky samples. The optical design and performance with particular respect to the rejection of specularly reflected radiation are discussed, and results for different varnishes are shown.
Site-Selection Phosphorimetry via Singlet-State Excitation
Authors: Vo-Dinh Tuan , Lamotte Michael
Published: July 2005

This paper describes the technique of excitation energy site-selection (SS) phosphorimetry for chemical analysis of polycyclic aromatic compounds in Shpolskii matrices at 4.2 K. The principle of the SS phosphorescence technique, which uses excitation via the singlet state and produces narrow-band phosphorescence, is discussed. The analysis of a three-component mixture is used to illustrate the spectral selectivity of the SS phosphorimetric technique.
Protein Adsorption on the Surface of a Thin-Film Polymer Integrated Optical Waveguide
Authors: Ives J. T. , Reichert W. M.
Published: July 2005

Protein adsorption (fluorescein labeled gamma globulin, FITC-IgG) on the surface of poly(styrene) thin-film optical waveguides was fluorescently detected. The time course of adsorption, the FITC-IgG fluorescence spectra, and the surface concentration estimates are presented. The results demonstrate the potential use of polymer optical waveguides as integrated optic evanescent sensors.
Rigid-Ion-Model Treatment of the Vibrational Spectra of Calcium and Strontium Chloride Hexahydrate Crystals
Authors: Winnett W. Kevin , Nash Charles P.
Published: July 2005

Single-crystal Raman spectra at 77 K in the 80–3500 cm−1 range are reported for CaCl2 · 6H2O(D2O) and SrCl2 · 6H2O(D2O). Excellent fits to the experimental spectra were obtained with the use of a thirteen-parameter force field based on the rigid-ion model supplemented with stretching and bending force constants for the water molecules and selected short-range force constants in the Bravais cell. The libration frequencies of both the bridging (four-coordinate) and the terminal (three-coordinate) water molecules were found to depend almost exclusively on their partial charges.
Evaluation of Space Radiator Performance by Simulation of Infrared Emission
Authors: Ohta Koji , Graf Robert T. , Ishida Hatsuo
Published: July 2005

The total performance of a droplet space radiator has been predicted by simulation of infrared emission spectra. Emission spectra for a droplet are simulated with the use of exact optical theory from the optical constant spectra of a low-molecular-weight silicone, which is a candidate for use as an emission medium of the radiator. Emissive power and total emittance are calculated from the simulated emission spectra for a droplet at different temperatures. It is found that the fourth-power temperature dependence of the emissive power of the blackbody and the temperature dependence of the emissivity inherent to the materials govern the emissive power of the droplet. The progressive decreases in temperature of a droplet and a droplet sheet in space are also simulated. A droplet with a diameter of 1 μm is predicted to cool from 500 K to 252 K in two seconds. The effects of the size of a droplet and the number density of the droplets in the sheet on the cooling rate are estimated. A smaller droplet is essential for obtaining effective radiation in the liquid droplet radiator. A dense cloud of the droplet sheet will retard the cooling rate of the droplets because of the reabsorption of the emitted light.
Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part VII
Authors: Coleman W. M. , Gordon Bert M.
Published: July 2005

A series of lactones and lactams have been examined by matrix isolation Fourier transform infrared spectrometry. The values for the carbonyl absorption bands fall between those reported for the same compounds in the vapor phase and solid state. Multiple absorption bands are found in the region of carbonyl absorption for compounds examined under the matrix isolation phase. Ring strain has a dramatic effect on simplifying the complexity of the spectra. Little or no aggregation effects are observed for either the lactones or lactams under accepted operating parameters. The effects of substituents on these systems are comparable to those found in the vapor-phase and solid-state data.
A Solution to the Artifact Problem in Fourier Transform Vibrational Circular Dichroism
Authors: Malon Petr , Keiderling Timothy A.
Published: July 2005

Using a newly constructed FT-IR vibrational circular dichroism (VCD) instrument, we have found that elimination of the ellipsoidal collection mirror before the detector and its replacement by a lens leads to a significant improvement in the absorption artifact problem seen previously in FT-IR/VCD. In the mid-IR region, we have been able to measure VCD of a single enantiomer for molecules such as α-pinene, 3-methylcyclohexanone, and dimethyltartrate. More importantly, this reduction in artifact level brings the FT-IR/VCD band shape of some particularly-difficult-to-measure bands, such as carbonyl stretches, into better agreement with those found in dispersive measurements. These results imply that the dispersive results are reliable, though of lower resolution than those obtained with the use of FT-IR/VCD.
A Characterization of Spark-Produced Aerosols by Automated Electron Probe Micro-Analysis
Authors: Raeymaekers B. , Van Espen P. , Adams F. , Broekaert J. A. C.
Published: July 2005

Aerosols produced from different metal samples with the aid of a high-repetition-rate spark (400 s−1) at medium voltage were investigated with an automated electron microprobe. Particles produced from different aluminium-alloy, brass, and iron samples were mostly spherical in shape, with a mean particle diameter between 1 and 2 μm. The composition of the particles well matches the bulk composition, but elemental redistribution over the different particle size classes occurs. It is postulated from the data obtained that analyte evaporation from a liquid phase in the burning crater and sputtering of material that only partly remelts when passing through the spark channel could be responsible for the aerosol production.