bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relating membrane potential to impedance spectroscopy
Authors: Gheorghiu Eugen 
Published: December 2011

Abstract
Non-invasive, label-free assessment of membrane potential of living cells is still a challenging task. The theory linking membrane potential to the low frequency α dispersion exhibited by suspensions of spherical shelled particles (presenting a net charge distribution on the inner side of the shell) has been pioneered in our previous studies with emphasis on the permittivity spectra. Whereas α dispersion is related to a rather large variation exhibited by the permittivity spectrum, we report that the related decrement presented by the impedance magnitude spectrum is either extremely small, or occurs (for large cells) at very small frequencies (~mHz) explaining the lack of experimental bioimpedance data on the matter.
We stress that appropriate choice of the parameters (as revealed by the microscopic model) may enable access to membrane potential as well as to other relevant parameters when investigating living cells and charged lipid vesicles. We analyse the effect on the low frequency of the permittivity and impedance spectra of: I. Parameters pertaining to cell membrane i.e. (i) membrane potential (through the amount of the net charge on the inner side of the membrane), (ii) size of the cells/vesicles, (iii) conductivity of the membrane; II. Parameters of the extra cellular medium (viscosity and conductivity).
The applicability of the study has far reaching implications for basic (life) sciences (providing non-invasive access to the dynamics of relevant cell parameters) as well as for biosensing applications, e.g. assessment of cytotoxicity of a wide range of stimuli.
Using the Initial Systolic Time Interval to assess cardiac autonomic nervous function in Parkinson’s disease
Authors: Meijer Jan H. , Elbertse Eskeline , Boesveldt Sanne , Berendse Henk W. , Verdaasdonk Rudolph M. 
Published: December 2011

Abstract
The Initial Systolic Time Interval (ISTI) has been defined as the time difference between the peak electrical and peak mechanical activity of the heart. ISTI is obtained from the electro-cardiogram and the impedance cardiogram. The response of ISTI while breathing at rest and to a deep breathing stimulus was studied in a group of patients suffering from Parkinson’s disease (PD) and a group of healthy control subjects. ISTI showed substantial variability during these manoeuvres. The tests showed that the variability of RR and ISTI was substantially different between PD patients and controls. It is hypothesized that in PD patients the sympathetic nervous system compensates for the loss of regulatory control function of the blood-pressure by the parasympathetic system. It is concluded that ISTI is a practical, additional and independent parameter that can be used to assist other tests in evaluating autonomic nervous control of the heart in PD patients.
Cross‐Coupling with Organosilicon Compounds
Authors: Chang Wen‐Tau T. , Smith Russell C. , Regens Christopher S. , Bailey Aaron D. , Werner Nathan S. , Denmark Scott E. 
Published: December 2011

AbstractOrganosilicon functions possess many properties that make them ideal donors of organic groups in cross‐coupling reactions. Through the addition of an appropriate silicophilic Lewis base, anin situpentacoordinate silane can effectively transfer an organic group. This feature allows for the rapid development of silicon cross‐coupling methods that continue today. Organosilicon‐based cross‐coupling has now become a practical, viable, and in some cases, superior compared with organoboron,‐zinc,‐tin couplings. The unique properties of organosilicon compounds provide a number of distinct advantages to their use as donors in transition‐metal catalyzed cross‐coupling reactions: 1, silicon moieties can be introduced into organic substrates by many general and high‐yielding methods for the construction of silicon carbon bonds; 2, organosilicon reagents are chemically robust and allow isolation and purification of products and are compatible with many functional groups; 3, silicon‐containing by‐products of the coupling are of low molecular weight, are nontoxic, and are easily removed from the reaction mixture; 4, a number of mild methods are available.This chapter presents a thorough overview of the various combinations of transferable groups and organic electrophiles. The scope is limited to the combination of silicon‐bearing nucleophiles with halo or related electrophiles under catalysis by palladium or nickel complexes wherein the silyl halide is lost.
The Aza‐Cope/Mannich Reaction
Authors: Overman Larry E. , Humphreys Philip G. , Welmaker Gregory S. 
Published: December 2011

AbstractBecause of their ability to rapidly build molecular complexity, reactions that construct several carbon‐carbon bonds are of special value in organic synthesis. Among these transformations, cascade reactions form several bonds by an orchestrated sequence in which the first bond‐forming step reveals functionality that allows subsequent bond forming transformations. In 1979 such a sequence for the synthesis of 3‐acylpyrrolidines and azacyclic structures that contain this unit was reported. This reaction is now commonly called the aza‐Cope/Mannich reaction, a [3,3]‐sigmatropic rearrangement of an unsaturated iminium cation generates the iminium ion and enol that are participants in a subsequent intramolecular Mannich reaction.The aza‐Cope/Mannich reaction has not been the subject of comprehensive review. This chapter covers the common version of the transformation discussed above along with the formation of 3‐acylpyrrolidines by a related base‐promoted cascade sequence.
Hip fractures in the United States: 2008 nationwide emergency department sample
Authors: Kim Sunny H. , Meehan John P. , Blumenfeld Thomas , Szabo Robert M. 
Published: December 2011

AbstractObjectiveTo evaluate the recent epidemiology of hip fractures in the US.MethodsWe identified hip fracture cases from the 2008 Nationwide Emergency Department Sample, which contains more than 28 million emergency department (ED) records.ResultsIn 2008, approximately 341,000 (95% confidence interval 323,000–358,000) patients visited EDs with hip fractures. Of those, 90% were age >60 years. Between ages 60–85 years, the risk of fracture doubled for every 5‐ to 6‐year increase in age. However, the hip fracture risk increased slowly after age 85 years. The overall trochanteric‐to‐cervical fracture ratio was nearly 2:1. The risk of trochanteric fracture increased faster with age compared with the risk of cervical fracture. At age 85 years, the rates of trochanteric and cervical fractures (per 100,000) were 1,300 and 700, respectively, among women and 800 and 500, respectively, among men.ConclusionThe slowed growth of hip fracture risk after age 85 years suggests that the eldest old group may have a distinct hip fracture risk. Our study showed that trochanteric fractures were twice as common as cervical fractures. Because trochanteric fractures are more closely related to severe and generalized bone loss than cervical fractures, we hypothesize that the high incidence rate of trochanteric fractures in the US suggests that osteoporosis is a health problem that is linked to hip fracture. In addition to improved safety measures to reduce falls, rigorous preventive treatments of osteoporosis may be needed.
Association of discoid lupus erythematosus with clinical manifestations and damage accrual in a multiethnic lupus cohort
Authors: Santiago‐Casas Yesenia , Vilá Luis M. , McGwin Gerald , Cantor Ryan S. , Petri Michelle , Ramsey‐Goldman Rosalind , Reveille John D. , Kimberly Robert P. , Alarcón Graciela S. , Brown Elizabeth E. 
Published: December 2011

AbstractObjectiveTo determine the clinical manifestations and disease damage associated with discoid rash in a large multiethnic systemic lupus erythematosus (SLE) cohort.MethodsSLE patients (per American College of Rheumatology [ACR] criteria) ages ≥16 years with a disease duration of ≤10 years at enrollment and defined ethnicity (African American, Hispanic, or white) from a longitudinal cohort were studied. Socioeconomic–demographic features, clinical manifestations, and disease damage (per the Systemic Lupus International Collaborating Clinics/ACR Damage Index) were determined. The association of discoid lupus erythematosus (DLE) with clinical manifestations and disease damage was examined using multivariable logistic regression.ResultsA total of 2,228 SLE patients were studied. The mean ± SD age at diagnosis was 34.3 ± 12.8 years and the mean ± SD disease duration was 7.9 ± 6.0 years; 91.8% were women. DLE was observed in 393 patients with SLE (17.6%). In the multivariable analysis, patients with DLE were more likely to be smokers and of African American ethnicity and to have malar rash, photosensitivity, oral ulcers, leukopenia, and vasculitis. DLE patients were less likely to be of Hispanic (from Texas) ethnicity and to have arthritis, end‐stage renal disease, and antinuclear, anti–double‐stranded DNA, and antiphospholipid antibodies. Patients with DLE had more damage accrual, particularly chronic seizures, scarring alopecia, scarring of the skin, and skin ulcers.ConclusionIn this cohort of SLE patients, DLE was associated with several clinical features, including serious manifestations such as vasculitis and chronic seizures.
Estimation of stature and body mass from the skeleton among coastal and mid‐altitude andean populations
Authors: Pomeroy Emma , Stock Jay T. 
Published: December 2011

AbstractAdult stature and body mass represent fundamental biological characteristics of individuals and populations, as they are relevant to a range of problems from assessing nutrition and health to longer term evolutionary processes. Stature and body mass estimation from skeletal dimensions are therefore key to addressing biological and social questions about past populations. Anatomical reconstruction provides the most direct proxy for living stature but is only suitable for well‐preserved remains. Regression equations for estimating stature from bone lengths are therefore extremely useful, though it is well recognized that differences in body proportions limit the cross‐application of equations between samples. Here, we assess the accuracy of published stature estimation equations from worldwide and New World groups applied to archaeological samples from the central Andean coast and highlands of South America. As no existing equations are clearly appropriate, new sample‐specific regression equations are presented. Anatomical stature reconstruction is further complicated by artificial cranial modification (ACM) influencing cranial height in Andean samples, so this problem is investigated in the current sample. Although ACM has minimal impact here, the possibility should be explored in other samples before anatomical stature estimation is attempted. Recommendations are also made for estimating body mass from femoral head diameter. The mean of three previously published equations is shown to offer minimal bias and the most reliable estimate of body mass in the study samples. Am J Phys Anthropol 147:264–279, 2012. © 2011 Wiley Periodicals, Inc.
Brief communication: Fecal androgen excretion and fetal sex effects during gestation in wild assamese macaques (Macaca assamensis)
Authors: Fürtbauer Ines , Heistermann Michael , Schülke Oliver , Ostner Julia 
Published: December 2011

AbstractIn placental mammals, pregnancy usually is associated with an increase in maternal androgens, which may significantly impact fetal growth and differentiation, and affect postnatal development and behavior. Owing to their slow life histories and challenging social conditions, determination of maternal androgens and potential interference effects of fetal androgen production are of particular interest in wild primates. However, androgen production has been rarely investigated in wild female primates, and studies on maternal androgens during gestation in particular often do not span the entire pregnancy. Here, we characterize fecal androgen production throughout gestation in wild Assamese macaques (Macaca assamensis) using noninvasive hormone analysis and, furthermore, examine fetal sex effects on maternal androgen excretion. A total of 207 fecal samples were analyzed from seven females for concentrations of immunoreactive epiandrosterone (iEA). Fecal iEA concentrations, as predicted based on cercopithecine blood‐serum patterns, increased during early gestation and were significantly higher during the first trimester compared with preconception concentrations and those recorded during later stages of gestation. Further, during the third trimester, male‐carrying mothers showed significantly higher iEA concentrations compared with female‐carrying mothers. This first characterization of fecal androgen excretion during gestation in Assamese macaques indicates both a maternal and fetal effect on androgen production. Although our sample size is small, our results, nevertheless, provide the basis for assessing potential influences of maternal androgens on postnatal offspring development and behavior. Am J Phys Anthropol 147:334–339, 2012. © 2011 Wiley Periodicals, Inc.
Morbidity in the marshes: Using spatial epidemiology to investigate skeletal evidence for malaria in Anglo‐Saxon England (AD 410–1050)
Authors: Gowland R.L. , Western A.G. 
Published: December 2011

AbstractConcerns over climate change and its potential impact on infectious disease prevalence have contributed to a resurging interest in malaria in the past. A wealth of historical evidence indicates that malaria, specifically Plasmodium vivax, was endemic in the wetlands of England from the 16th century onwards. While it is thought that malaria was introduced to Britain during the Roman occupation (AD first to fifth centuries), the lack of written mortality records prior to the post‐medieval period makes it difficult to evaluate either the presence or impact of the disease. The analysis of human skeletal remains from archaeological contexts is the only potential means of examining P. vivax in the past. Malaria does not result in unequivocal pathological lesions in the human skeleton; however, it results in hemolytic anemia, which can contribute to the skeletal condition cribra orbitalia. Using geographical information systems (GIS), we conducted a spatial analysis of the prevalence of cribra orbitalia from 46 sites (5,802 individuals) in relation to geographical variables, historically recorded distribution patterns of indigenous malaria and the habitat of its mosquito vector Anopheles atroparvus. Overall, those individuals living in low‐lying and Fenland regions exhibited higher levels of cribra orbitalia than those in nonmarshy locales. No corresponding relationship existed with enamel hypoplasia. We conclude that P. vivax malaria, in conjunction with other comorbidities, is likely to be responsible for the pattern observed. Studies of climate and infectious disease in the past are important for modeling future health in relation to climate change predictions. Am J Phys Anthropol 147:301–311, 2012. © 2011 Wiley Periodicals, Inc.
An update on attitudes and use of image‐guided surgery
Authors: Justice Jeb M. , Orlandi Richard R. 
Published: December 2011

AbstractBackground:The aim of this study was to compare 2010 access to, usage of, and attitudes toward image‐guided surgery (IGS) for endoscopic sinus surgery and anterior skull‐base surgery to those in 2005.Methods:A mail survey of American Rhinologic Society (ARS) members was performed in January 2010. Results were compared to results from the same survey mailed in January 2005.Results:Significantly more respondents in 2010 had access to IGS compared to 2005 (94.6% vs 86%, p = 0.002). Compared to 2005, IGS was used in a greater percentage of cases in 2010 (p < 0.0001). More respondents in 2010 felt that IGS is indicated for primary anterior ethmoidectomy, revision anterior ethmoidectomy, primary total ethmoidectomy, Lothrop procedure, cerebrospinal fluid (CSF) leak repair, tumor surgery, orbital decompression, and optic nerve decompression (all p < 0.05). Similar to 2005, region, residency completion date, and availability of IGS in residency had no measureable effect on attitudes toward IGS. As in 2005, availability of IGS was associated with a greater feeling of its necessity in 2010.Conclusion:IGS availability has grown significantly and nearly all ARS members now have access. Estimates of use by respondents have also increased over the last 5 years, particularly for ethmoid and advanced procedures. Revision surgery and advanced procedures continue to be chief indications for IGS use. As in 2005, the results of this survey reflect the opinion of the respondents, and do not necessarily reflect the views of the ARS or of practicing otolaryngologists in general. © 2011 ARS‐AAOA, LLC.
Wide variation and rising utilization of stroke magnetic resonance imaging: Data from 11 States
Authors: Burke James F. , Kerber Kevin A. , Iwashyna Theodore J. , Morgenstern Lewis B. 
Published: December 2011

AbstractObjective:Neuroimaging is an essential component of the acute stroke evaluation. Magnetic resonance imaging (MRI) is more accurate than computed tomography (CT) for the diagnosis of stroke, but is more costly and time‐consuming. We sought to describe changes in MRI utilization from 1999 to 2008.Methods:We performed a serial cross‐sectional study with time trends of neuroimaging in patients with a primary International Classification of Diseases, 9th Edition, Clinical Modification discharge diagnosis of stroke admitted through the emergency department in the State Inpatient Databases from 10 states. MRI utilization was measured by Healthcare Cost and Utilization Project criteria. Data were included for states from 1999 to 2008 where MRI utilization could be identified.Results:A total of 624,842 patients were hospitalized for stroke in the period of interest. MRI utilization increased in all states. Overall, MRI absolute utilization increased 38%, and relative utilization increased 235% (28% of strokes in 1999 to 66% in 2008). Over the same interval, CT utilization changed little (92% in 1999 to 95% in 2008). MRI use varied widely by state. In 2008, MRI utilization ranged from a low of 55% of strokes in Oregon to a high of 79% in Arizona. Diagnostic imaging was the fastest growing component of total hospital costs (213% increase from 1999 to 2007).Interpretation:MRI utilization during stroke hospitalization increased substantially, with wide geographic variation. Rather than replacing CT, MRI is supplementing it. Consequently, neuroimaging has been the fastest growing component of hospitalization cost in stroke. Recent neuroimaging practices in stroke are not standardized and may represent an opportunity to improve the efficiency of stroke care. Ann Neurol 2012;71:179–185
Tethering methoxy polyethylene glycols to improve the antifouling property of PSF/PAA‐blended membranes
Authors: Yu Haijun , Cao Yiming , Kang Guodong , Liu Jianhui , Li Meng 
Published: December 2011

AbstractPoly(acrylic acid) (PAA) was used as an additive to fabricate blended polysulfone (PSF) ultrafiltration (UF) membranes. Hexanediamine was used as a crosslinking agent to react with PAA and formed an active surface with amine group. Then, an end carboxyl group methoxy polyethylene glycol (MPEG) was grafted on the membrane surface via an amidation reaction. Water contact angle measurement indicated that the surface hydrophilicity of PSF/PAA‐blended membranes and MPEG‐modified membranes remarkably increased. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR) was used to confirm the existence of PAA in the blended membranes and the change of chemical composition. Membrane surface and cross‐sectional morphologies were observed by scanning electron microscope. The flux of pure water increased slightly after modification, while the rejection to bovine serum albumin had no obvious change. The improvement of antifouling property for MPEG‐modified membrane was accordant with the increase of PAA content in PSF/PAA‐blended membranes. Protein UF experiments revealed that membrane fouling, especially irreversible membrane fouling, was remarkably reduced due to the incorporation of MPEG. The long‐term protein UF experiment demonstrated the improvement of recycling property and the reliability of modification. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of the concentration of the sizing agent on the carbon fibers surface and interface properties of its composites
Authors: Zhang R. L. , Huang Y. D. , Li N. , Liu L. , Su D. 
Published: December 2011

AbstractThe effect of the concentration of the sizing agent on performances of carbon fiber and carbon fiber composites has been investigated. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were applied to characterize carbon fiber surface topographies. At the same time, the single fiber strengths and Weibull distribution were also studied. The interlaminar shear strength and hygrothermal ageing test have been used to study the effect of fiber coatings on the interface of the composites. The analysis of the results shows that the sizing level is essential for improving the surface of carbon fibers and its composite performance. Different concentrations of the sizing agent have different contributions to the wetting performance of carbon fibers. Among the three concentrations of sizing agent studied (1 wt %, 1.5 wt %, and 2 wt %), the optimal sizing level is 1.5 wt %. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 125:425–432, 2011
Wetting and adhesion behavior of armos fibers after dielectric barrier discharge plasma treatment
Authors: Jia Caixia , Chen Ping , Wang Qian , Li Bin , Chen Mingxin 
Published: December 2011

AbstractTo investigate the influence of atmospheric plasma treatment on aramid fiber wetting and adhesion behavior, an air dielectric barrier discharge (DBD) was applied to the Armos aramid fiber surface at different discharge power densities. Dynamic contact angle analysis indicated that the total surface free energy was increased from 49.6 to 68.3 mJ/m2, an increment of 37.7%, whereas the single‐fiber tensile strength testing showed that the mechanical properties of the Armos fibers were almost unaffected. With the enhancement of fiber surface wettability, the interlaminar shear strength, which was used to determine the interfacial adhesion in Armos‐fiber‐reinforced thermoplastic poly(phthalazinone ether sulfone ketone) composites, increased by 17.2% to 71.4 MPa. Scanning electron microscopy photos showed that the predominant failure mode of the composites changed from interface failure to matrix and/or fiber failure after the plasma treatment. Taken together, these results suggest that the air DBD plasma was an effective technique for improving the surface and interfacial performance of the Armos fibers without damaging their bulk properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012