bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitation of interaction of lipids with polymer surfaces in cell culture
Authors: Altaras Gina M. , Eklund Carrie , Ranucci Colette , Maheshwari Gargi 
Published: September 2006

AbstractAs cell culture medium development efforts have progressed towards leaner, serum‐free, and chemically defined formulations, it has become increasingly important to ensure that the appropriate concentrations of all nutrients are maintained and delivered at point of use. In light of concurrent efforts to progress to disposable polymeric storage and culture platforms, the characterization and control of medium component interactions with container surfaces can be a key issue in ensuring consistent delivery of these medium formulations. These studies characterize the interactions of lipids with culture surfaces typically encountered in the bioprocess industry using model systems. The extent and kinetics of lipid association with polymeric surfaces were determined using radio‐labeled linoleic acid and cholesterol. The effect of methyl‐β‐cyclodextrin, a component commonly used to solubilize lipids in culture media, on association kinetics was also examined. In addition, loss of lipids across a sterilizing membrane filter was quantified. We find that there is potential for significant loss of hydrophobic components due to non‐specific binding to surfaces at timescales relevant to a typical cell culture process. The extent of loss is dependent on the nature of the hydrophobic component as well as the type of surface. These studies highlight the potential of the extracellular environment to modify medium composition and also emphasize the importance of medium formulation strategies, including those used in the delivery of hydrophobic components. It is noted, however, that the level of loss is very dependent on the specific system including the composition of the culture medium used. Biotechnol. Bioeng. 2007;96:999–1007. © 2006 Wiley Periodicals, Inc.
Measurement of fast dynamic intracellular pH in Saccharomyces cerevisiae using benzoic acid pulse
Authors: Kresnowati M.T.A.P. , Suarez‐Mendez C. , Groothuizen M.K. , van Winden W.A. , Heijnen J.J. 
Published: September 2006

AbstractpH affects many processes on cell metabolism, such as enzyme kinetics. To enhance the understanding of the living cells, it is therefore indispensable to have a method to monitor the pH in living cells. To accomplish this, a dynamic intracellular pH measurement method applying low concentration benzoic acid pulse was developed. The method was thoroughly validated and successfully implemented for measuring fast dynamic intracellular pH of Saccharomyces cerevisiae in response to a glucose pulse perturbation performed in the BioSCOPE set‐up. Fast drop in intracellular pH followed by partial alkalinization was observed following the pulse. The low concentration benzoic acid pulse which was implemented in the method avoids the undesirable effects that may be introduced by benzoic acid to cell metabolism. Biotechnol. Bioeng. 2007;97:86–98. © 2006 Wiley Periodicals, Inc.
Effects of shear stress on 3‐D human mesenchymal stem cell construct development in a perfusion bioreactor system: Experiments and hydrodynamic modeling
Authors: Zhao Feng , Chella Ravindran , Ma Teng 
Published: September 2006

AbstractShear stress is an important biomechanical parameter in regulating human mesenchymal stem cell (hMSC) construct development. In this study, the biomechanical characteristics of hMSCs within highly porous 3‐D poly (ethylene terephthalate) (PET) matrices in a perfusion bioreactor system were analyzed for two flow rates of 0.1 and 1.5 mL/min, respectively over a 20‐day culture period. A 1.4 times higher proliferation rate, higher CFU‐F formation, and more fibronectin and HSP‐47 secretion at day 20 were observed at the flow rate of 0.1 mL/min compared to those at the flow rate of 1.5 mL/min. The higher flow rate of 1.5 mL/min upregulated osteogenic differentiation potential at day 20 as measured by the expression of alkaline phosphatase activity and calcium deposition in the matrix after 14 days osteogenic induction, consistent with those reported in literatures. Mathematical modeling indicated that shear stress existed in the range of 1 × 10−5 to 1 × 10−4 Pa in the constructs up to a depth of 70 µm due to flow penetration in the porous constructs. Analysis of oxygen transport in the constructs for the two flow rates yielded oxygen levels significantly higher than those at which cell growth and metabolism are affected (Jiang et al., 1996). This indicates that differences in convective transport have no significant influence on cell growth and metabolism for the range of flow rates studied. These results demonstrate that shear stress is an important microenvironment parameter that regulates hMSC construct development at a range significantly lower than those reported previously in the perfusion system. Biotechnol. Bioeng. 2007;96: 584–595. © 2006 Wiley Periodicals, Inc.
Exploiting Noninnocent (E,E)‐Dibenzylideneacetone (dba) Effects in Palladium(0)‐Mediated Cross‐Coupling Reactions: Modulation of the Electronic Properties of dba Affects Catalyst Activity and Stability in Ligand and Ligand‐Free Reaction Systems
Authors: Fairlamb Ian J. S. , Kapdi Anant R. , Lee Adam F. , McGlacken Gerard P. , Weissburger Felix , de Vries André H. M. , Schmieder‐van de Vondervoort Lizette 
Published: September 2006

AbstractThe reactivity of palladium(0) complexes, [Pd02(dba‐n,n′‐Z)3] (n,n′‐Z=4,4′‐F; 4,4′‐CF3; 4,4′‐H; 4,4′‐MeO) and [Pd0(dba‐n,n′‐Z)2] (n,n′‐Z=4,4′‐CF3; 4,4′‐H; 3,3′,5,5′‐OMe), used as precursor catalysts with suitable donor ligands (e.g. phosphines, N‐heterocyclic carbenes), has been correlated in several palladium(0)‐mediated cross‐coupling processes. Increasing the electron density on the aryl moiety of the dba‐n,n′‐Z ligand increases the overall catalytic activity in the majority of these processes. This effect primarily derives from destabilization of the LnPd0–η2‐dba interaction (in dπ–π* synergic bonding, n=1 or 2), which ultimately increases the global concentration of catalytically active LnPd0 available for reaction with aryl halide in the first committed step in the general catalytic cycle(s) (oxidative addition). Decreasing electron density on the aryl moiety of the dba‐n,n′‐Z ligand stabilizes the Pd0–η2‐dba interaction, reducing catalytic activity. The specific type of dba‐n,n′‐Z ligand appears to also play a stabilizing role in the catalytic cycle, preventing Pd agglomeration, and increasing catalyst longevity. A subtle balance therefore exists between the LnPd0 concentration (and the associated catalytic activity) and catalyst longevity. Changing the type of dba‐n,n′‐Z ligand controls the concentration of LnPd0 and the rate of the oxidative addition step, and not other intimate steps within the catalytic cycle(s), for example, transmetallation (or carbopalladation) and reductive elimination. The role of dba‐n,n′‐Z ligands in Heck arylation is more convoluted and dependant on the alkene substrate employed, although trends have emerged. Changes in the structure of dba‐n,n′‐Z had a minimal affect on Buchwald–Hartwig aryl amination processes. A secondary Michael reaction of dba‐n,n′‐Z with amine and/or base effectively lessens its interference in the catalytic cycle.
Inorganic‐Cored Photoactive Assemblies: Synthesis, Structure, and Photochemical Investigations on Stannoxane‐Supported Multifluorene Compounds
Authors: Chandrasekhar Vadapalli , Thilagar Pakkirisamy , Steiner Alexander , Bickley Jamie F. 
Published: September 2006

AbstractOrganostannoxanes were used as inert supports for the preparation of multichromophore assemblies. The synthesis involves a single‐step procedure and allows the preparation of compounds in which the number of chromophore units can be varied from one to six. Thus, the reactions of LCOOH (1‐fluorenecarboxylic acid) or L′COOH (9‐fluorenecarboxylic acid) with various organostannoxane precursors afforded the fluorenyl derivatives [Ph3SnO2CL] (1), [Ph3SnO2CL′] (2), [{nBu3SnO2CL′′}n] (3), [{nBu3SnO2CL′}n] (4), [{tBu2Sn(OH)O2CL}2] (5), [{tBu2Sn(OH)O2CL′}2] (6), [{[nBu2SnO2CL]2O}2] (7) [{[nBu2SnO2CL′]2O}2] (8), [{nBuSn(O)O2CL}6] (9), and [{nBuSn(O)O2CL′}6] (10). Interestingly, the formation of 3 is accompanied by an unusual oxo‐transfer reaction. The ligand L is oxidized at the 9‐position. Compounds 1, 3, 5, 7, and 8 were characterized by X‐ray crystallography. The solid‐state structures of these compounds reveal rich supramolecular structures owing to multiple intermolecular interactions between the various supramolecular synthons present in these molecules. The optical behavior of 1–10 is primarily dictated by the fluorenyl periphery. These compounds display strong blue fluorescent emission in solution and blue‐green fluorescent emission in the solid state. Fluorescence lifetimes of all of these compounds are on the nanosecond timescale, and this suggests that the emission originates from the singlet excited state to the ground state. Intermolecular interactions in the solid state lead to considerable broadening of the emission bands.
Dependence of s‐waves on continuous dimension: The quantum oscillator and free systems
Authors: Wolf K.B. , Aceves‐de‐la‐Cruz F. 
Published: September 2006

AbstractWavefunctions with rotational symmetry (i.e., zero angular momentum) in D dimensions, are called s‐waves. In quantum quadratic systems (free particle, harmonic and repulsive oscillators), their radial parts obey Schrödinger equations with a fictitious centrifugal (for integer D ≥ 4) or centripetal (for D = 2) potential. These Hamiltonians close into the three‐dimensional Lorentz algebra so(2,1), whose exceptional interval corresponds to the critical range of continuous dimensions 0 < D < 4, where they exhibit a one‐parameter family of self‐adjoint extensions in ℒ︁2(ℜ︁+). We study the characterization of these extensions in the harmonic oscillator through their spectra which – except for the Friedrichs extension – are not equally spaced, and we build their time evolution Green function. The oscillator is then contracted to the free particle in continuous‐D dimensions, where the extension structure is mantained in the limit of continuous spectra. Finally, we compute the free time evolution of the expectation values of the Hamiltonian, dilatation generator, and square radius between three distinct sets of ‘heat’‐diffused localized eigenstates. This provides a simple group‐theoretic description of the purported contraction/expansion of Gaussian‐ring s‐waves in D > 0 dimensions.
Split‐thickness skin grafting in postmastoidectomy revision and in lateral temporal bone resection
Authors: Renton John P. , Wetmore Stephen J. 
Published: September 2006

ObjectivesUse of split‐thickness skin grafts (STSG) in revision canal wall‐down (CWD) mastoidectomy was compared with STSG in lateral temporal bone resection (LTBR).Study Design and SettingA retrospective study of 11 patients undergoing revision CWD mastoidectomy and 6 patients undergoing LTBR with STSG in an academic health center setting.ResultsSuccessful epithelialization of the mastoid cavity occurred in 9 patients (82%) undergoing CWD mastoidectomy. Subjective success, measured as reduction in complaints of otorrhea, occurred in 10 patients (91%). In the 6 patients who underwent LTBR and STSG successful epithelialization of the temporal bone defect occurred in 5 patients (83%).ConclusionsSuccessful and rapid epithelialization occurred in the revision mastoidectomy cohort as well as in the primary temporal bone resection cohort.SignificancePlacement of STSG is a useful adjunct in revision CWD mastoidectomy as well as in primary LTBR for cancer.
Epidemiology of head and neck cancer in the United States
Authors: Davies Louise , Welch H. Gilbert 
Published: September 2006

BackgroundCancer rates of the head and neck are traditionally linked to public health issues.ObjectiveTo describe the epidemiology of head and neck cancer in the United States.Design and SettingNational Cancer Institute's Surveillance Epidemiology and End Results (SEER) program. RESULTS: A total of 75,000 cases of head and neck cancer were diagnosed in 2001. Incidence is rising in thyroid (up 52%), bone (43%) soft tissues (20%), salivary (20%), tongue (16%), tonsil (12%), and nose (12%). Incidence is falling in lip (down 58%), hypopharynx (35%), cervical esophagus (32%), oropharyngeal mucosa (26%), and larynx (26%). There were 30,000 deaths from head and neck cancer in 2001. Mortality has decreased to some degree at all sites except thyroid where it was stable.ConclusionMany head and neck cancers have changing incidence and mortality rates contrary to expected changes given trends in public health issues. Further investigation of risk factors, diagnostic practices, and management strategies is warranted.EBM rating: 2C
Reappraisal of metastatic lymph node topography in head and neck squamous cell carcinomas
Authors: Tao Lei , Lefèvre Marine , Callard Patrice , Périé Sophie , Bernaudin Jean‐François , Guily Jean Lacau St 
Published: September 2006

ObjectiveTo analyze the lymphatic distribution of metastatic carcinomatous cells in cervical lymph nodes in head and neck squamous cell carcinoma (HNSCC).Study Design and SettingWe retrospectively reviewed 119 patients treated in our hospital for HNSCC (1999‐2004). Topography of the neck dissection specimens was prospectively classified according to the classification of Robbins. The 4000 lymph nodes were analyzed by optical microscopy using hematoxylin‐eosin‐safran (HES) staining. In cases of negative results in level II, cytokeratin (AE1/AE3) immunodetection was performed.ResultsMetastases were visualized using HES in 6.4% of lymph nodes for oral cavity, and 4.7% of oropharyngeal, 4.4% of hypopharyngeal, and 1.3% of endolaryngeal cancers. The highest incidence of nodal metastasis was observed in level IIa (P < 0.01). In eight patients (6.7%) with lymph node metastases, level II was spared. In these patients, all 134 nodes histologically negative on HES were confirmed to be negative by IHC.ConclusionsLevel IIa is the main level involved in regional metastases of HNSCC, regardless of the primary site of cancer. However, in eight (6.7%) patients, level II was spared, as confirmed by IHC. In these cases, level II did not represent the first step of drainage from the tumor. The sentinel lymph node technique in HNSCC is discussed in light of these results.
Complication rate of minimally invasive cochlear implantation
Authors: Stratigouleas Elias D. , Perry Brian P. , King Susan Marenda , Syms Charles A. 
Published: September 2006

ObjectivesTo assess the complication rate of minimally invasive cochlear implantation (MICI).Study Design and SettingData for this study were obtained via a retrospective analysis of records at the Ear Medical Group, San Antonio, TX, after IRB approval at the University of Texas Health Science Center at San Antonio. The surgical complications of MICI were recorded in a spreadsheet format; 176 patients were included in the study.ResultsA total of 22 (12.5%) complications were noted in the study. There were 0 life‐threatening, 7 major, and 15 minor complications. Of the 7 major complications, 3 were device failures, 2 developed delayed mastoiditis, 1 required receiver/stimulator repositioning, and 1 involved facial paralysis.ConclusionsMICI is as safe as standard cochlear implantation (SCI) and affords with it other benefits. Eliminating the scalp flap avoids devascularization and minimizes the opportunity of flap infection or necrosis. Complications not related to the flap are similar to SCI.EBM rating: C‐4
Radiation dosimetry of the FluoroCAT scan for real‐time endoscopic sinus surgery
Authors: Manarey Casey R.A. , Anand Vijay K. 
Published: September 2006

Objective/HypothesisThe FluoroCAT platform of the GE InstaTrak 3500 Plus reconstructs images acquired from the GE OEC 9800 Plus fluoroscope into triplanar images which allow the surgeon to perform real‐time endoscopic sinus and skull‐base surgery. The radiation dosimetry for the new scanning protocol required by the FluoroCAT has not been reported. This study was designed to measure the radiation dose of a FluoroCAT scan and compare this to the dosimetry of an InstaTrak CT scan.Study DesignProspective study.MethodsA standardized CT head phantom was used along with a CT ion chamber to measure radiation exposure. FluoroCAT scans were performed using the GE OEC 9800 Plus fluoroscope. Scans were performed using each of the three fluoroscopic scanning modes on the GE OEC 9800 Plus; normal fluoro, high‐level fluoro, and Digital Ciné at 15 pulses per second (pps).ResultsThe highest radiation dose was measured using Digital Ciné 15 pps. The dose measured at the center of the head phantom was 4.1 Gy while the maximum surface dose was 10.7 mGy. The center and surface radiation dose recorded from the CTDIvol reading on the control panel of a GE Lightspeed Plus during an InstaTrak CT scan was 85 mGy.ConclusionsUsing the GE OEC 9800 Plus fluoroscope to accumulate images for the FluoroCAT platform in the InstaTrak 3500 Plus resulted in less radiation compared to an InstaTrak CT scan. This will allow multiple scans to be performed intraoperatively, giving the surgeon the opportunity to perform real‐time endoscopic sinus and skull‐base surgery.EBM rating: C‐4
Modified superficial parotidectomy: Preserving both the great auricular nerve and the parotid gland fascia
Authors: Zumeng Ya , Zhi Gao , Gang Zhang , Jianhua Wang , Yinghui Tan 
Published: September 2006

ObjectiveTo reduce the incidence of sensory deficits and Frey's syndrome by modifying the traditional superficial parotidectomy.Study DesignAfter raising the skin flap, the parotid gland fascia (PGF) was elevated to form a posterior pedicle fascial flap and then was replaced after the gland removal. The great auricular nerve (GAN) that runs within the PGF was not separated, so both the GAN and the PGF were preserved. Before this modification, the GAN and PGF were examined anatomically. The complication rates in the modified and control groups were compared.Results1) The GAN, which runs within the thick and pycnotic PGF, trifurcates into postauricular, preauricular and lobule branches. The modification could be carried out practically based on the anatomy study. 2) Long‐term sensory deficit was encountered in 13.3% of the control group, but 0% in the modified one. Frey's syndrome was suffered by 66.7% and 16.7% cases in the control and modified group respectively. The incidence of other complications was not significantly different.ConclusionOur modification is practical. It decreases the complications significantly.EBM rating: B‐3b
Removal of nonthyroidal neck masses with improved cosmetic outcomes in skin‐lifting surgery
Authors: Roh Jong‐Lyel , Yoon Yeo‐Hoon , Park Chan 
Published: September 2006

ObjectiveTo evaluate the cosmetic benefit of neck skin‐lifting surgery for the removal of nonthyroidal neck masses.Study Design and SettingFifty patients with neck masses were divided into the following 2 surgical groups that were matched in age, sex, and the size, location, and pathology of lesions: skin lifting (n = 25) and conventional (n = 25). The operation time, hospital stay, complications, and subjective satisfaction with the incision scar as assessed on a visual analogue scale (VAS) were compared between the 2 groups.ResultsAll but 2 lesions (lymphomas) were benign and were removed completely, drained, or biopsied. The surgery time, hospital stay, and complication rates did not differ significantly between the groups. The mean satisfaction score of the patients was 8.2 ± 1.1 in the skin‐lifting surgery group and 4.8 ± 2.5 in the controls (P < 0.001). The incision scars were commonly hidden by natural hair or collars in the patients who received skin‐lifting surgery.ConclusionThis surgical technique can be safely applied to most benign masses in the entire neck excluding the thyroid region, especially in patients who prefer neck scars to be invisible.EBM rating: B‐2b
CT analysis and histopathology of bone remodeling in patients with chronic rhinosinusitis
Authors: Cho Seok Hyun , Min Hyun Jung , Han Hong Xiu , Paik Seung Sam , Kim Kyung Rae 
Published: September 2006

ObjectiveTo evaluate the findings of computed tomography (CT) and histopathology of the bulla ethmoidalis as objective markers of bone remodeling in chronic rhinosinusitis (CRS).MethodsPreoperative ostiomeatal unit (OMU) scans and histopathologic findings of the bulla ethmoidalis were performed on 23 patients (39 sides) undergoing endoscopic sinus surgery for CRS. Lund‐Mackay scores and Hounsfield units (HU) of the bulla were checked in coronal CT scans. The pathologist graded the severities of the mucosal and bony changes in histopathology. Statistical analysis was performed using Mann‐Whitney U test and Spearman correlation coefficient (r).ResultsThe HU values of the bulla were significantly increased with higher Lund‐Mackay scores in OMU CT (r = 0.405, P = 0.01). The bony grades in histopathology were significantly increased with higher mucosal grades (r = 0.821, P = 0.0001). These findings in CT scans and histopathology were well correlated with each other (r > 0.3, P < 0.05).ConclusionHU may be a useful objective marker of bone remodeling in chronic rhinosinusitis.
Association of airway abnormalities and risk factors in 37 subglottic stenosis patients
Authors: Poetker David M. , Ettema Sandra L. , Blumin Joel H. , Toohill Robert J. , Merati Albert L. 
Published: September 2006

ObjectivesThe study objective is to characterize the airway abnormalities in a series of patients with subglottic stenosis (SGS) as they relate to etiology and risk factors.Study Design and SettingRetrospective review, academic medical center. Airway characteristics, patient demographics, and suspected risk factors were recorded from a database of SGS cases from 2001 to 2004.ResultsThirty‐seven patients with SGS were identified; 22 of 37 had isolated SGS (59%). Intubation (10 of 37, 27%), high tracheotomy (4 of 37, 11%), and reflux (5 of 37, 14%) comprised the bulk of cases; 13 of 37 (35%) were considered idiopathic. Of 22 patients with isolated SGS, the majority 18 of 22 (P = 0.06) were women, 59% of which were idiopathic. Multiple‐level cases (0 of 15) were idiopathic (P < 0.001). Intubation was the most common cause of multiple site stenosis (6 of 15, 40%).ConclusionsThe majority of patients in this study had isolated lesions. These patients tend to have no apparent risk factors. Multi‐level cases are associated with prolonged intubation and known injuries. The nature of “idiopathic” stenoses is discussed.SignificanceClinical examination of SGS may be meaningful in understanding the etiology of the stenosis.
Impact of electrode insertion depth on intracochlear trauma
Authors: Adunka Oliver , Kiefer Jan 
Published: September 2006

ObjectiveTo assess the effect of cochlear implant (CI) insertion depth and surgical technique on intracochlear trauma.Study Design and SettingTwenty one fresh human temporal bones were implanted with CI electrodes and underwent histologie processing and evaluation. Specimens were grouped into 3 categories: 1) soft implantation technique and standard electrode; 2) soft implantation technique and flexible prototype array; 3) forceful implantations and standard electrode. Based on the grading system (1 to 4), 2 numeric values were calculated indicating the overall severity of cochlear damage (trauma indices).ResultsMean trauma index values were 13.8, 36.3, and 59.2 for group 1, 2, and 3, respectively. Differences in cochlear trauma (trauma index) were nonsignificant between specimens in groups 1 and 2 but were significant between groups 1 and 3.ConclusionThis study gives evidence that intracochlear trauma increases with deep insertions. Thus, in cases where cochlear integrity might be important, limited insertions should be achieved.ConclusionThis study gives evidence that intracochlear trauma increases with deep insertions. Thus, in cases where cochlear integrity might be important, limited insertions should be achieved.