bluuebunny/crossref_metadata_2025 huggingface dataset:
HIV‐1 alters neural and glial progenitor cell dynamics in the central nervous system: Coordinated response to opiates during maturation
Authors: Hahn Yun Kyung , Podhaizer Elizabeth M. , Hauser Kurt F. , Knapp Pamela E.
Published: August 2012

HIV‐associated neurocognitive disorders (HANDs) are common sequelae of human immunodeficiency virus (HIV) infection, even when viral titers are well controlled by antiretroviral therapy. Evidence in patients and animal models suggests that neurologic deficits are increased during chronic opiate exposure. We have hypothesized that central nervous system (CNS) progenitor cells in both adult and developing CNS are affected by HIV infection and that opiates exacerbate these effects. To examine this question, neural progenitors were exposed to HIV‐1 Tat1–86 in the developing brain of inducible transgenic mice and in vitro. We examined whether Tat affected the proliferation or balance of progenitor populations expressing nestin, Sox2, and Olig2. Disease relevance was further tested by exposing human‐derived progenitors to supernatant from HIV‐1 infected monocytes. Studies concentrated on striatum, a region preferentially targeted by HIV and opiates. Results were similar among experimental paradigms. Tat or HIV exposure reduced the proliferation of undifferentiated (Sox2+) progenitors and oligodendroglial (Olig2+) progenitors. Coexposure to morphine exacerbated the effects of Tat or HIV‐1SF162 supernatant, but partially reversed HIV‐1IIIB supernatant effects. Populations of Sox2+ and Olig2+ cells were also reduced by Tat exposure, although progenitor survival was unaffected. In rare instances, p24 immunolabeling was detected in viable human progenitors by confocal imaging. The vulnerability of progenitors is likely to distort the dynamic balance among neuron/glial populations as the brain matures, perhaps contributing to reports that neurologic disease is especially prevalent in pediatric HIV patients. Pediatric disease is atypical in developed regions but remains a serious concern in resource‐limited areas where infection occurs commonly at birth and through breast feeding. © 2012 Wiley Periodicals, Inc.
Effects of managed care mechanisms on access to healthcare: results from a qualitative study in Colombia
Authors: Vargas Ingrid , Unger Jean‐Pierre , Mogollón‐Pérez Amparo Susana , Vázquez M. Luisa
Published: August 2012

Background

Managed competition has underpinned most health sector reforms aimed at improving access and efficiency, in Latin America and other countries. The aim of the paper is to analyse barriers to healthcare that emerge from the introduction of managed care mechanisms in Colombia.

Methods

Qualitative, exploratory, and descriptive‐interpretative research was carried out on the basis of case studies of four healthcare networks, comprised of insurers and their providers. Individual semi‐structured interviews were conducted with a theoretical sample of informants (managers, professionals, and users), between 24 and 61 per network. The final sample size was reached by saturation of information. An inductive thematic content analysis was conducted. The study areas were two municipalities of Colombia, in which most of the population live in poverty.

Results

A number of managed care mechanisms that act as barriers to access were identified by all informants, regardless of area and type of insurance regime. These mechanisms act directly on the patient (authorizations, fragmented insurance) or on the providers (purchasing mechanisms or limits to medical practice). The predominant mechanism appears to be related to the type of agreement established between insurers and providers. The reason for these barriers, according to informants, is insurers' search for profitability. As a consequence, there is delay in or no access to adequate treatment. This is particularly evident in secondary care.

Conclusion

A variety of managed care strategies that effectively hinder access to healthcare have been introduced by insurers, casting doubt on the usefulness of their application in low‐income countries and profit‐making contexts. Copyright © 2012 John Wiley & Sons, Ltd.
Fibrin‐chitosan composite substrate for in vitro culture of chondrocytes
Authors: Gamboa‐Martínez T. C. , García Cruz D. M. , Carda C. , Ribelles J. L. Gómez , Ferrer G. Gallego
Published: August 2012

The aim of this study was to develop a biocompatible monolayer substrate based on fibrin and chitosan for in vitro culture of chondrocytes. Fibrin‐chitosan composite substrates combined the proved cell adhesion properties of fibrin with the hydrophilicity and poor adhesion capacity of chitosan. Chitosan microspheres were produced by coacervation method, agglomerated within a fibrin network and subsequently crosslinked with genipin. The composite substrate was stable for 28 days of culture due to the high crosslinking density. Human chondrocytes cultured on the composite substrate were viable during the culture period. At the end of culture time (28 days) the composite substrate showed low cellular proliferation, 41% more collagen type II and 13% more production of sulfated glycosaminoglycans with respect to the amounts found at 14 days. The study revealed that dedifferentiated chondrocytes cultured in monolayer on the composite substrate can re‐acquire characteristics of differentiated cells without using three‐dimensional substrates or chondrogenic media. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Biofunctionalization of titanium surface with multilayer films modified by heparin‐VEGF‐fibronectin complex to improve endothelial cell proliferation and blood compatibility
Authors: Wang H. G. , Yin T. Y. , Ge S. P. , Zhang Q. , Dong Q. L. , Lei D. X. , Sun D. M. , Wang G. X.
Published: August 2012

In‐stent restenosis and subsequent thrombosis remain a significant complication following the implantation of coronary stents. Different approaches have been used in developing novel coronary stents to protect against thrombosis and minimize restenosis. In the present study, we designed a biomacromolecular layer‐by‐layer coating with heparin, vascular endothelial growth factor (VEGF), and fibronectin onto nickel‐free titanium surface to improve blood compatibility and endothelial cell proliferation. The multilayer assembling process was monitored by water contact angle and surface plasmon resonance, respectively. With increasing the number of layers, the deposition of polyelectrolyte as self‐assembled ultrathin multilayer films showed linear growth of absorbance. In vitro blood compatibility results revealed that the fabricated layers prolonged activated partial thrombin time and prothrombin time, reduced platelets activation and aggregation, and reduced blood hemolysis rate. Cell adhesion and growth results showed that the assembled multilayer films significantly promoted cell attachment and growth, and the endothelialization property of the multilayer films was preferable compared with the untreated titanium disk. In conclusion, these results suggest that titanium surface modification using biofunctional multilayer films composed of heparin, VEGF, and fibronectin may serve as a potential approach to inhibit thrombosis and promote re‐endothelialization of cardiovascular stents. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Engineered bone tissue associated with vascularization utilizing a rotating wall vessel bioreactor
Authors: Nishi Masanori , Matsumoto Rena , Dong Jian , Uemura Toshimasa
Published: August 2012

Tissue‐engineered bone has attracted much attention as an alternative material for bone grafting; however, implantable bone tissue of an appropriate size and shape for clinical use has not yet been developed due to a lack of vascularization, which results in necrosis of the seeded cells in vivo. This is the first report of bone tissue engineering associated with vascularization by co‐culturing bone marrow mesenchymal stem cells (MSCs) with MSC‐derived endothelial cells (ECs) within a porous scaffold using a rotating wall vessel (RWV) bioreactor. MSC‐derived ECs were identified by immunofluorescence staining for von Willebrand factor (vWF) and by flow cytometry for CD31 expression. The tissue obtained was histochemically analyzed using toluidin blue, hematoxylin and eosin, anti‐osteopontin antibody, anti‐osteocalcin antibody, and tomato‐lectin stain. Results showed that bone tissue containing vascular‐like structures was generated. Three‐dimensional culture condition created by medium flow in the RWV vessel and the interaction of MSCs with MSC‐derived ECs might provide the cells an advantage in the construction of three‐dimensional bone tissue with blood vessels. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Addition of perfluorocarbons to alginate hydrogels significantly impacts molecular transport and fracture stress
Authors: White Joseph C. , Stoppel Whitney L. , Roberts Susan C. , Bhatia Surita R.
Published: August 2012

Perfluorocarbons (PFCs) are used in biomaterial formulations to increase oxygen (O2) tension and create a homogeneous O2 environment in three‐dimensional tissue constructs. It is unclear how PFCs affect mechanical and transport properties of the scaffold, which are critical for robustness, intracellular signaling, protein transport, and overall device efficacy. In this study, we investigate composite alginate hydrogels containing a perfluorooctyl bromide (PFOB) emulsion stabilized with Pluronic® F68 (F68). We demonstrate that PFC addition significantly affects biomaterial properties and performance. Solution and hydrogel mechanical properties and transport of representative hydrophilic (riboflavin), hydrophobic (methyl and ethyl paraben), and protein (bovine serum albumin, BSA) solutes were compared in alginate/F68 composite hydrogels with or without PFOB. Our results indicate that mechanical properties of the alginate/F68/PFOB hydrogels are not significantly affected under small strains, but a significant decrease fracture stress is observed. The effective diffusivity Deff of hydrophobic small molecules decreases with PFOB emulsion addition, yet the Deff of hydrophilic small molecules remained unaffected. For BSA, the Deff increased and the loading capacity decreased with PFOB emulsion addition. Thus, a trade‐off between the desired increased O2 supply provided by PFCs and the mechanical weakening and change in transport of cellular signals must be carefully considered in the design of biomaterials containing PFCs. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Nano‐hydroxyapatite‐coated PEEK implants: A pilot study in rabbit bone
Authors: Barkarmo Sargon , Wennerberg Ann , Hoffman Maria , Kjellin Per , Breding Karin , Handa Paul , Stenport Victoria
Published: August 2012

Osseointegration of surface‐modified polyetheretherketone (PEEK) implants was studied in vivo. A total of 18 cylinder‐shaped PEEK implants were inserted in the femurs of nine New Zealand rabbits; half were coated with nanocrystalline hydroxyapatite (nanoHA) and half were uncoated controls. Healing time was 6 weeks. Samples were retrieved with the implant and surrounding tissue, processed to cut and ground sections, and analyzed histomorphometrically. The implant surfaces were analyzed with optical interferometry, scanning electron microscopy (SEM), atomic force microscopy, and X‐ray photoelectron spectroscopy (XPS). NanoHA‐coated PEEK surfaces had lower height deviation (Sa) than controls [mean ± SD: 0.41 μm (±0.14) vs. 0.96 μm (±0.28)]. SEM images showed the nanoHA crystals as a thin layer on the polymer surface. XPS analysis of the coated implants showed a Ca/P ratio of 1.67. Histomorphometry indicated that the nanoHA‐coated implants had more bone‐to‐implant contact [16% (±4.7) vs. 13% (±9.3)] and more bone area [52% (±9.5) vs. 45% (±11.9)]. We found no difference between smooth nanoHA‐coated cylinder‐shaped PEEK implants and uncoated controls. However, higher mean bone‐to‐implant contact indicated better osseointegration in the coated implants than in the uncoated controls. The large number of lost implants was interpreted as a lack of primary stability due to implant design. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Synthesis of galactosylated chitosan/5‐fluorouracil nanoparticles and its characteristics, in vitro and in vivo release studies
Authors: Cheng Mingrong , Han Jiang , Li Qing , He Bing , Zha Bingbing , Wu Jingbo , Zhou Runjiao , Ye Tao , Wang Wei , Xu Hongzhi , Hou Yiming
Published: August 2012

Biodegradable polymer nanoparticle drug delivery systems are characterized by targeted drug delivery, improved pharmacokinetic and biodistribution, enhanced drug stability, and lowered side effects; these drug delivery systems are widely used for delivery of cytotoxic agents. The galactosylated chitosan (GC)/5‐fluorouracil (5‐FU) nanoparticle is a nanomaterial made by coupling GC, a polymer known to have the advantages described above, and 5‐FU. We found that when 5‐FU and GC were mixed at the mass ratio of 10:1, the nanoparticle reached a maximum encapsulation efficiency of 81.82% ± 5.32%, with a drug loading of 6.12% ± 1.36%, a particle size of 35.19 ± 9.50 nm, and a Zeta potential of +10.34 ± 1.43 mV. The GC/5‐FU nanoparticle is a sustained release system, whose anticancer effects were shown to be dose and time dependent, with a higher cytotoxicity to hepatic cancer than to other cell types. The distribution of GC/5‐FU in vivo revealed the greatest accumulation in the hepatic cancer tissues, with an 8.69‐, 23.35‐, 79.96‐, and 85.15‐fold increase when compared to normal liver tissue, kidney, heart and blood, respectively, suggesting that the hepatic cell was the target of the nanoparticles. In vivo experiments showed that GC/5‐FU can significantly inhibit tumor growth in an orthotropic liver cancer mouse model. GC/5‐FU treatment can significantly lower the tumor weight and increase the survival time of mice when compared to 5‐FU treatment alone. Flow cytometry revealed that compared to 5‐FU, GC/5‐FU caused higher rates of G0–G1 arrest and apoptosis in hepatic cancer cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Cycle Extensions in BIBD Block‐Intersection Graphs
Authors: Abueida Atif A. , Pike David A.
Published: August 2012

A cycle C in a graph G is extendable if there is some other cycle in G that contains each vertex of C plus one additional vertex. A graph is cycle extendable if every non‐Hamilton cycle in the graph is extendable. A balanced incomplete block design, BIBD, consists of a set V of v elements and a block set of k‐subsets of V such that each 2‐subset of V occurs in exactly λ of the blocks of . The block‐intersection graph of a design is the graph having as its vertex set and such that two vertices of are adjacent if and only if their corresponding blocks have nonempty intersection. In this paper, we prove that the block‐intersection graph of any BIBD is cycle extendable. Furthermore, we present a polynomial time algorithm for constructing cycles of all possible lengths in a block‐intersection graph.
Isolated interrupted aortic arch in 42‐year‐old adult—case report
Authors: Liping Chen , Pradhan Dipesh , Jing Zhang , Hongwei Zhou , Shrestha Rajina
Published: August 2012

Interrupted aortic arch (IAA) is a rare congenital anomaly characterized by a complete luminal and anatomical interruption between the ascending and descending thoracic aorta. It is usually detected in the perinatal period or during infancy, but a very few cases have been reported in adults. Here, we present the case of a 42‐year‐old man who visited our hospital for arterial hypertension and in whom IAA was diagnosed with echocardiography and confirmed by computed tomography angiography. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 41:521–523, 2013;
Hospital medicine in the internal medicine clerkship: Results from a national survey
Authors: Liston Beth W. , O'Dorisio Nathan , Walker Curt , Torre Dario , Papp Klara K.
Published: August 2012

BACKGROUND:

Hospital medicine is growing rapidly. This changing inpatient work force has had consequences on medical education, with an increasing hospitalist presence in resident and student training. Initially met with apprehension, there is growing literature to suggest that hospitalists are perceived to be more effective clinical teachers than non‐hospitalists. However, the extent to which hospitalists are involved in teaching Internal Medicine (IM) to medical students is not known.

METHODS:

In order to determine the role of hospitalists in medical student education within the United States and Canada, we queried clerkship directors in Internal Medicine as part of the 2010 annual Clerkship Directors in Internal Medicine (CDIM) survey. In June 2010, CDIM surveyed its North American institutional members, which represent 110 of 143 Departments of Medicine in the US and Canada.

RESULTS:

Eight‐two of 107 departments responded to the survey (77%). Seventy‐five (91%) indicated that hospitalists served as teaching attendings at their teaching hospital. In twenty‐two (27%) IM departments, 75% to 100% of students rotate with a hospitalist during their IM clerkships. Thirty‐three (42%) departments report that students are directly supervised by in‐house hospitalists during their nighttime call requirements. Sixty‐six (81%) indicated that academic hospitalists hold educational administrative positions. Hospitalists are significantly less likely to have additional clinical commitment as compared to non‐hospitalist teaching attendings (16% vs 53%, (χ = 33.1; P < 0.0001).

CONCLUSIONS:

Hospitalists are involved in medical student education in the large majority of Departments of Internal Medicine throughout the US and Canada, reflecting the growth of hospital medicine nationally. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
Hospitalist‐led medicine emergency department team: Associations with throughput, timeliness of patient care, and satisfaction
Authors: Chadaga Smitha R. , Shockley Lee , Keniston Angela , Klock Nancy E. , Van Dyke Susan , Davis Quin , Chu Eugene S.
Published: August 2012

BACKGROUND:

Admitted patients boarding in the emergency department (ED) leads to hospital diversion. Active bed management and care for boarded patients can improve throughput. We developed a hospital medicine ED (HMED) team to participate in active bed management, and to care for boarded patients, to decrease diversion and improve throughput.

METHODS:

An HMED team was created to participate in active bed management and to care for boarded patients. The HMED team worked with the ED, nursing supervisors, and medical floors to manage inpatient beds. The primary outcome was percentage of hours of diversion attributed to lack of bed capacity. Secondary outcomes included the proportion of patients discharged within 8 hours of transfer to a medical floor, and the proportion of patients discharged from the ED. Promptness of clinical care was measured by rounding times. Satisfaction was obtained via survey.

RESULTS:

There was a relative reduction of diversion due to medicine bed capacity of 27% (4.5%–3.3%; P < 0.01), a relative reduction in the percentage of patients transferred to a medicine floor and discharged within 8 hours of 67% (1.5%–0.5%; P < 0.01), and a relative increase in the number of discharges from the ED of admitted medicine patients of 61% (4.9%–7.9%; P < 0.001). Boarded admitted patients were rounded upon 2 hours earlier (P < 0.0001) by the HMED team. Satisfaction with the HMED team was high.

CONCLUSION:

An HMED team can improve patient flow and decrease ED diversion while providing more timely care to patients boarded in the ED. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
Early recognition of acutely deteriorating patients in non‐intensive care units: Assessment of an innovative monitoring technology
Authors: Zimlichman Eyal , Szyper‐Kravitz Martine , Shinar Zvika , Klap Tal , Levkovich Shiraz , Unterman Avraham , Rozenblum Ronen , Rothschild Jeffrey M. , Amital Howard , Shoenfeld Yehuda
Published: August 2012

BACKGROUND:

Continuous vital sign monitoring has the potential to detect early clinical deterioration. While commonly employed in the intensive care unit (ICU), accurate and noninvasive monitoring technology suitable for floor patients has yet to be used reliably.

OBJECTIVE:

To establish the accuracy of the Earlysense continuous monitoring system in predicting clinical deterioration.

DESIGN:

Noninterventional prospective study with retrospective data analysis.

SETTING:

Two medical wards in 2 academic medical centers.

PATIENTS:

Patients admitted to a medical ward with a diagnosis of an acute respiratory condition.

INTERVENTION:

Enrolled patients were monitored for heart rate (HR) and respiration rate (RR) by the Earlysense monitor with the alerts turned off.

MEASUREMENTS:

Retrospective analysis of vital sign data was performed on a derivation cohort to identify optimal cutoffs for threshold and 24‐hour trend alerts. This was internally validated through correlation with clinical events recognized through chart review.

RESULTS:

Of 113 patients included in the study, 9 suffered major clinical deterioration. Alerts were found to be infrequent (2.7 and 0.2 alerts per patient‐day for threshold and trend alert, respectively). For the threshold alerts, sensitivity and specificity in predicting deterioration was found to be 82% and 67%, respectively, for HR and 64% and 81%, respectively, for RR. For trend alerts, sensitivity and specificity were 78% and 90% for HR, and 100% and 64% for RR, respectively.

CONCLUSIONS:

The Earlysense monitor was able to continuously measure RR and HR, providing low alert frequency. The current study provides data supporting the ability of this system to accurately predict patient deterioration. Journal of Hospital Medicine 2012; © 2012 Society of Hospital Medicine
On the use of a spin‐echo based double inversion recovery acquisition for the measurement of cortical brain thickness
Authors: Nam Yoonho , Kim Eung Yeop , Kim Dong‐Hyun
Published: August 2012

Purpose:

To determine whether a spin‐echo‐based sequence, which are inherently insensitive to magnetic field inhomogeneity, can be used for brain cortical thickness measurement studies.

Materials and Methods:

By using a double inversion recovery (DIR) spin‐echo‐based sequence, cortical thickness estimates were performed from data acquired from seven healthy volunteers. The cortical thickness was also calculated from data acquired using an MPRAGE sequence and the Bland‐Altman analysis was performed for comparison of the two methods. The average signal and contrast to noise ratios (SNR, CNR) of the two methods were also calculated.

Results:

The bias over the entire brain between DIR and MPRAGE was 0.87 ± 0.08 mm. The bias calculated in the major regional lobes were temporal: 0.76 ± 0.09 mm, frontal: 0.89 ± 0.07 mm, parietal: 0.92 ± 0.10 mm, occipital: 0.75 ± 0.12 mm, and cingulate: 0.79 ± 0.10 mm. This thickness difference was due mainly to the boundary difference in the MPRAGE and DIR at the grey matter/cerebral spinal fluid (GM/CSF) regions. The mean SNR and CNR was CNRMPRAGE = 47.8 ± 8.4 and CNRDIR = 19.2 ± 2.9, SNRMPRAGE = 76.8 ± 10.5 and SNRDIR = 21.1 ± 2.8.

Conclusion:

The study suggests that cortical thickness measurements can be performed using a DIR spin‐echo sequence, which is inherently immune to main field inhomogeneity. Larger thickness measurements were consistently observed in DIR compared with MPRAGE. J. Magn. Reson. Imaging 2011;33:1218–1223. © 2011 Wiley‐Liss, Inc.
Correlation of monomer structures of tripalmitin with the spectroscopic fingerprint of polymorphs: infrared, Raman, and DFT study
Authors: Pilarczyk M. , Wrobel T. P. , Baranska M. , Kaczor A.
Published: August 2012

In the light of application of vibrational spectroscopy in medical diagnosis, it is necessary to have a tool to distinguish between different lipids that may be present in biochemical samples such as cells and tissues. One of the most common lipids in the human body are triglycerides. Therefore, the aim of this work was to investigate the model triglyceride, namely tripalmitin in order to find the differences between the vibrational signatures of its polymorphs and interpret them with the help of quantum‐chemical computations. Although monomeric models are not sufficient to reproduce polymorphs structure, analysis of these models is very helpful in understanding of relations between the structure and changes in vibrational spectra. Copyright © 2012 John Wiley & Sons, Ltd.
Raman imaging on high‐quality graphene grown by hot‐filament chemical vapor deposition
Authors: Kataria S. , Patsha Avinash , Dhara S. , Tyagi A. K. , Barshilia Harish C.
Published: August 2012

We report the synthesis of high‐quality graphene on Cu foils using hot‐filament chemical vapor deposition technique and demonstrate that by suitably varying the CH4 and H2 flow rates, one can also obtain hydrogenated graphene. Micro‐Raman spectroscopy studies confirm the growth of monolayer graphene as inferred from the intensity ratio of 2D to G peak which is nearly four in unhydrogenated samples. Detailed Raman area mapping confirms the uniform coverage of monolayer graphene. The grown layer is also transferred onto a Si substrate over ~10 × 10 mm sq. area. The present results provide a leap in synthesis technology of high‐quality graphene and pave way for scaling up the process. Copyright © 2012 John Wiley & Sons, Ltd.
Raman analysis of glaze on various archaeological shard samples and intact Ming plates
Authors: Kock L. D.
Published: August 2012

Raman microscopy is used in the analysis of glaze on a number of samples that include blue and white ceramic shards, a tile from the Citadel of Algiers and intact Ming plates. The use of the glaze depth profiling method for the study of interfacial pigments on these samples [J. Raman Spectrosc. 2007; 38: 1480] prompted the study of the glaze on the same set of samples to determine glaze type dependence of this method. Using the index of polymerization (Ip) which is closely correlated with glaze composition and processing temperature, it is shown that processing temperature could be estimated from a low of about 600 °C for some of the unknown archaeological shards to about 1000 °C or above for the Ming porcelain shards. Two intact porcelain plates from the Hongzhi (1488 – 1505) and Wanli (1573 – 1620) Ming imperial periods from the J. A. van Tilburg Museum of the University of Pretoria have been studied, and glaze/glass transition temperature was estimated to be above 1000 °C, consistent with historical data. A SnO2‐based glaze tile shard from the Citadel of Algiers was also successfully probed, and results indicated a much lower sintering temperature. Copyright © 2012 John Wiley & Sons, Ltd.
Observation of low‐wavenumber out‐of‐plane optical phonon in few‐layer graphene
Authors: Shang Jingzhi , Cong Chunxiao , Zhang Jun , Xiong Qihua , Gurzadyan Gagik G. , Yu Ting
Published: August 2012

Few‐layer graphene grown by chemical vapor deposition has been studied by Raman and ultrafast laser spectroscopy. A low‐wavenumber Raman peak of ~120 cm−1 and a phonon‐induced oscillation in the kinetic curve of electron–phonon relaxation process have been observed, respectively. The Raman peak is assigned to the low‐wavenumber out‐of‐plane optical mode in the few‐layer graphene. The phonon band shows an asymmetric shape, a consequence of so‐called Breit‐Wigner‐Fano resonance, resulting from the coupling between the low‐wavenumber phonon and electron transitions. The obtained oscillation wavenumber from the kinetic curve is consistent with the detected low‐wavenumber phonon by Raman scattering. The origin of this oscillation is attributed to the generation of coherent phonons and their interactions with photoinduced electrons. Copyright © 2012 John Wiley & Sons, Ltd.
FT‐Raman spectroscopy for quantitative analysis of salt efflorescences
Authors: Broggi Alessandra , Petrucci Elisabetta , Bracciale Maria Paola , Santarelli Maria Laura
Published: August 2012

Salt crystallization in porous materials constitutes one of the major causes of decay of buildings and archeological sites. Depending on the environmental conditions, salts can crystallize inside the porous network (subflorescence or cryptoefflorescence) on the material surface (efflorescence or compact crust). Generally speaking, the salt deposits may comprise different inorganic ions (i.e. sodium or potassium sulphates, nitrates or chlorides), and they cause several damages, i.e. flaking, alveolar weathering, crumbling, loss of material or dissolution. In order to determine the nature and the concentration of salts, ionic chromatography (IC) is generally used. Although valuable, the IC analytical method presents a number of drawbacks, i.e. requires long sample preparation times, different sample dilutions, and the determined values are referred only to the ionic species (cations or anions). For a quick quantitative identification, the Raman spectroscopy appears more suitable, but a calibration of such analytical method is necessary. The present paper deals with the application of Fourier transform (FT)‐Raman spectroscopy to the study of soluble salts constituting the most diffuse efflorescences in monuments and archeological sites. The FT‐Raman calibration was set up by measuring the band integration area of each standard salt solution at the more intense and/or well‐resolved band. Twelve control mixtures were tested, and the calibration curve fitting was evaluated. The obtained results were compared with IC determinations performed on the same salt mixtures.

The FT‐Raman spectroscopy demonstrated to be an easy approach to salt quantitative analyses, that in addition enables the direct identification of the nature of the analyzed samples. Copyright © 2012 John Wiley & Sons, Ltd.
Aerobic stability of distillers wet grains as influenced by temperature
Authors: Lehman R Michael , Rosentrater Kurt A
Published: August 2012

BACKGROUND: The storability of distillers wet grains (DWG) influences the economic, energetic, and carbon balances of fuel ethanol production, yet there are limited published data on the deterioration of DWG following its production. We used biogenic CO2 production to assess the aerobic stability of DWG incubated at three temperatures (12 °C, 22 °C, 32 °C) and compared CO2 production over time to the appearance of mold and changes in DWG color parameters.

RESULTS: CO2 production and mold colonization indicate that at temperatures near 12 °C, the aerobic stability of DWG was high and that it can be stored for at least a 10‐day period. At temperatures close to 22 °C, the onset of increased microbial activity and visible mold colonization occurred between 4 and 7 days and both activity and mold ratings were very high by the ninth day in all three experiments. At 32 °C, 2 days may be a more appropriate limit for storage.

CONCLUSION: Temperature and time interact in a nonlinear fashion that permits the prediction of DWG stability boundaries. The simple visual appearance of mold appears to be a reasonable indicator that correlates well (r = 0.694) with CO2 production, a measure of the aerobic stability of DWG. Published 2012 by John Wiley & Sons, Ltd.
Effects of illumination conditions on preferred viewing distance of portable liquid‐crystal television
Authors: Lee Der‐Song , Shen I‐Hsuan
Published: August 2012

This study explored the effect of TV size, light source, and ambient illumination on the preferred viewing distance of portable liquid‐crystal‐display televisions. Results showed that the mean preferred viewing distance was 1389 mm. TV size had significant effects on preferred viewing distance. The larger the screen size, the greater the preferred viewing distance, at around 6.7–14.7 times the width of the screen (W). Light sources revealed no significant effect on preferred viewing distance. The effect of ambient illumination on preferred viewing distance was significant. The higher the ambient illumination was, the longer the preferred viewing distance.
Guidelines for an improved quality of experience in 3‐D TV and 3‐D mobile displays
Authors: Xu Di , Coria Lino E. , Nasiopoulos Panos
Published: August 2012

Stereoscopic (3‐D) movies have become widely popular all over the world. In addition, 3‐D TVs and mobile devices have already been introduced to the consumer market. However, while some manufacturers are introducing 3‐D cameras and movie studios are using proprietary solutions, there are no guidelines for consistently capturing high‐quality stereoscopic content. In this paper, a comprehensive stereoscopic image and video database with content captured at various distances from the camera lenses and under different lighting conditions will be presented. Subjective tests to assess the perceived 3‐D quality of these videos and images, which were shown on displays of different sizes, have been conducted. In addition, the horizontal parallax of the content was adjusted to verify via subjective tests whether this change could increase the viewer's quality of experience. Finally, guidelines of acquisition distances between the cameras and the real scene will be published.
Alternative method for gas chromatography‐mass spectrometry analysis of short‐chain fatty acids in faecal samples
Authors: García‐Villalba Rocio , Giménez‐Bastida Juan A. , García‐Conesa Maria T. , Tomás‐Barberán Francisco A. , Carlos Espín Juan , Larrosa Mar
Published: August 2012

Short‐chain fatty acids are the major end products of bacterial metabolism in the large bowel. They derive mostly from the bacterial breakdown of carbohydrates and are known to have positive health benefits. Due to the biological relevance of these compounds it is important to develop efficient, cheap, fast, and sensitive analytical methods that enable the identification and quantification of the short‐chain fatty acids in a large number of biological samples. In this study, a gas chromatography‐mass spectrometry method was developed and validated for the analysis of short‐chain fatty acids in faecal samples. These volatile compounds were extracted with ethyl acetate and 4‐methyl valeric acid was used as an internal standard. No further cleanup, concentration, and derivatization steps were needed and the extract was directly injected onto the column. Recoveries ranged between 65 and 105%, and no matrix effects were observed. The proposed method has wide linear ranges, good inter‐ and intraday variability values (below 2.6 and 5.6%, respectively) and limits of detection between 0.49 μM (0.29 μg/g) and 4.31 μM (3.8 μg/g). The applicability of this analytical method was successfully tested in faecal samples from rats and humans.
Hydrodynamic chromatography separations in micro‐ and nanopillar arrays produced using deep‐UV lithography
Authors: Op de Beeck Jeff , De Malsche Wim , De Moor Piet , Desmet Gert
Published: August 2012

We report on a series of hydrodynamic chromatography separations conducted in micropillar array columns with an interpillar distance spacing of, respectively, 1.00, 0.70, and 0.47 μm. The columns have been produced using state‐of‐the‐art deep‐UV lithography and deep reactive ion etching techniques. Despite the fact that the efficiency was smaller than theoretically possible (due to fabrication limitations and significant injection and detection band broadening), it was nevertheless possible to separate mixtures of fluorescein isothiocyanate (used as the t0‐marker) and 20‐ and 40‐nm polystyrene beads. With the smallest interpillar distance, a resolution of Rs = 0.5 between the 20‐ and 40‐nm particles could be obtained in 90s over a column length of 4 cm. The selectivity obtained in the pillar array columns was found to be very similar to that observed in packed‐bed columns. By detecting the fluorescent signals in a 90‐μm‐deep detection groove at the end of the column, the signal‐to‐noise ratio could be enhanced up to 150 times.
HPLC enantioseparation of alkaloid malacitanine using fluorimetric/polarimetric detection
Authors: Sánchez Francisco García , Navas Díaz Aurora , Aguilar Alfonso , Medina Lama Ignacio , Algarra Manuel
Published: August 2012

This work reports two methods developed for the separation and determination of the enantiomers of the new alkaloid malacitanine (MLC) and the determination of the enantiomeric purity in mixtures. First, the isomers were separated using a Chirex 3020 (250 mm × 4.6 mm, 5 μm) chiral column with a mobile phase of cyclohexane–1,2‐dichloroethane–ethanol–trifluoroacetic acid (64:30:6:0.6, v/v/v/v) at a flow rate of 1 mL/min and fluorimetric detection. Obtained retention times were 12.4 and 15.9 min (+ and −) with a resolution Rs of 1.13. Relative standard deviations (RSDs) were 2.5 and 2.4% at the 0.5‐μg level (four determinations). Second, a nonenantioselective procedure for the determination of enantiomeric purity of MLC using a Lichrospher ® Si‐60 (250 mm × 5 mm, 5 μm) normal phase with a mobile phase of 100% ethanol at a flow rate of 0.9 mL/min coupled to two detectors in series, fluorimetric and polarimetric. RSD of 3.3% was obtained. Calculated enantiomeric purity by chiral chromatography gave 48.6% (−)‐MLC in the near racemic product. Using polarimetric signal of the nonseparated enantiomers and comparing the slopes of the calibration curves (enantiomers) from the racemic product gave 47.8% (−)‐MLC content. A study of accuracy of (−)‐MLC gave recoveries from 98.3 to 100.7%.
Fecal genotyping reveals demographic variation in river otters inhabiting a contaminated environment
Authors: Guertin Daniel A. , Ben‐David Merav , Harestad Alton S. , Elliott John E.
Published: August 2012

The deposition and accumulation of persistent contaminants into coastal systems can have lingering negative consequences for wildlife populations and their habitats. Using multi‐locus genotyping of non‐invasively collected feces, we assessed the effects of such pollution on reproduction, survival, genetic variability, and abundance of river otters (Lontra canadensis) along a gradient of urban–industrial development on southern Vancouver Island, British Columbia, Canada. Genetic analyses indicated a pattern consistent with small‐scale structuring, with individuals partitioned into 2 local subpopulations—those identified in the contaminated harbors of southern Vancouver Island and points west (Colwood/Harbors), and those inhabiting uncontaminated habitat east of the harbors (Oak Bay). Genetic and demographic analyses for the 2 clusters provide strong support for the conclusion that, despite contamination concerns, Colwood/Harbors river otters exhibited acceptable levels of survival and successfully reproduced (i.e., high levels of relatedness, high self‐recruitment, and high emigration). However, our data indicate that the Colwood/Harbors area constitutes lower quality habitat supporting lower densities of otters, especially during winter, and excess individuals produced in that region emigrate to other areas. Immigration into Colwood/Harbors, however, seems limited, possibly because of behavioral aversion of non‐habituated otters to anthropogenic disturbance associated with the harbors and limited optimal otter habitat. Our findings suggest that the effects of chronic contaminant exposure at the population level may be inadvertently mitigated through the behavioral decisions of individuals to avoid poor quality habitats. We conclude that populations of river otters can persist in and around locally contaminated sites if relatively less disturbed and contaminated habitats remain in the vicinity of the affected areas. © 2012 The Wildlife Society.
The effect of deep venous thrombosis on short‐term outcomes and cost of care after head and neck cancer surgery
Authors: Hennessey Patrick , Semenov Yevgeniy R. , Gourin Christine G.
Published: August 2012

Objectives/Hypothesis:

The Centers for Medicare and Medicaid Services has targeted deep venous thrombosis (DVT) and pulmonary embolus (PE) as preventable “never events” and has discontinued reimbursement for these conditions following selected orthopedic procedures. We sought to determine the relationship between DVT/PE and in‐hospital mortality, postoperative complications, length of stay, and costs in head and neck cancer (HNCA) surgery.

Study Design:

Retrospective cross‐sectional study.

Methods:

Discharge data from the Nationwide Inpatient Sample for 93,663 patients who underwent an ablative procedure for a malignant oral cavity, laryngeal, hypopharyngeal, or oropharyngeal neoplasm in 2003 to 2008 were analyzed using cross‐tabulations and multivariate regression modeling.

Results:

DVT/PE was diagnosed in 1,860 cases (2%) and was significantly associated with major surgical procedures (odds ratio [OR], 1.4; P = .048) and advanced comorbidity (OR, 1.7; P = .034). After controlling for all other variables, no association was found between a diagnosis of DVT/PE and obesity, weight loss, age, chronic cardiac disease, paralysis, and smoking in this HNCA surgical population. DVT/PE was associated with increased risk of in‐hospital mortality (OR, 3.1; P = .001), postoperative surgical complications (OR, 2.1; P < .001), acute medical complications (OR, 1.9; P < .001), and was associated with significantly increased length of hospitalization and hospital‐related costs.

Conclusions:

DVT/PE is uncommon in HNCA patients but is associated with increased mortality, postoperative complications, length of hospitalization, and hospital‐related costs. The lack of correlation with known modifiable variables suggests that despite advances in targeted prophylaxis, patients with advanced disease and comorbidity remain at increased risk. Caution must be used in the institution of reforms that threaten to inadequately reimburse the provision of care in vulnerable populations. Laryngoscope, 2012
Modification and testing of a pneumatic dispensing device for controlled delivery of injectable materials
Authors: Heaton James T. , Kobler James B. , Ottensmeyer Mark P. , Lopez‐Guerra Gerardo , Karajanagi Sandeep S. , Burns James A. , Zeitels Steven M.
Published: August 2012

Objectives/Hypothesis:

Vocal fold (VF) injections of viscous materials are typically performed using hand‐operated syringes or injection guns; however, these methods can be imprecise due to accumulation of pressure, effort‐related tremor, and poor feedback regarding injection volume and rate.

Study Design:

Apparatus development with laboratory bench‐top and animal model testing.

Methods:

A foot pedal‐triggered device for dispensing viscous materials was modified by adding a linear transducer and display for monitoring dispensed volume. In bench tests, bovine VFs were injected with fluids/materials of different viscosities (saline, glycerol, hydrogel, and liposuctioned fat) through narrow‐bore needles using a range of driving pressures and air pulse durations. The device was further evaluated in >50 in vivo VF injection experiments.

Results:

Device function was repeatable, with high correlations (typically R2 > 0.98) between the readout and direct measures of volume, even for small volumes (<5 μL/pulse). Foot pedal control enabled surgeons to make steady, accurate injections into ferret and dog VFs during phonosurgery, and, because the dispenser released all driving pressure between pulses, there were no instances of clog‐related overinjection when the obstruction cleared.

Conclusions:

This VF injection system shows promise for development to enhance human phonosurgery by increasing injection control and precision. Laryngoscope, 2012
Efficacy of the pillar implant in the treatment of snoring and mild‐to‐moderate obstructive sleep apnea: A meta‐analysis
Authors: Choi Ji Ho , Kim Soo‐Nyung , Cho Jae Hoon
Published: August 2012

Objectives/Hypothesis:

The Pillar implant is one of the surgical options for snoring and obstructive sleep apnea (OSA). It is designed to be inserted into the soft palate to reduce vibration and collapsibility. The efficacy of the Pillar implant has been evaluated in various studies. However, only one study conducted a meta‐analysis of the findings, and was based on only three studies. We tried to get a more definite conclusion on the efficacy of the Pillar implant.

Study Design:

Meta‐analysis.

Methods:

Efficacies were analyzed separately, one for snoring and the other for mild‐to‐moderate OSA. We searched MEDLINE, LILACS, SCOPUS, and the Cochrane Library. The key words “snoring AND implants” were used for snoring, and “apnea AND implants” for OSA. Seven studies for snoring and seven studies for mild‐to‐moderate OSA were finally included for meta‐analysis. For snoring patients, a visual analogue scale that is scored by the bed partner was used to evaluate the loudness of the snoring sound.

Results:

The Pillar implant reduced snoring sound significantly (standardized mean difference [SMD], −0.591; 95% confidence interval [CI], −0.753 to −0.429, P < .001). For mild‐to‐moderate OSA patients, the Pillar implant significantly reduced the Epworth Sleepiness Scale (SMD, −0.481; 95% CI, −0.606 to −0.358, P < .001), and apnea‐hypopnea index (SMD, −0.378; 95% CI, −0.619 to −0.138, P = .002). Mean extrusion rate was 9.3% (95% CI, 7.0 to 12.2%).

Conclusions:

The present results indicate that the Pillar implant has a moderate effect on snoring and mild‐to‐moderate OSA. However, we need more studies with high level of evidence to arrive at a definite conclusion. Laryngoscope, 2013
Long‐term effects of injection laryngoplasty with a temporary agent on voice quality and vocal fold position
Authors: Prendes Brandon L. , Yung Katherine C. , Likhterov Ilya , Schneider Sarah L. , Al‐Jurf Soha A. , Courey Mark S.
Published: August 2012

Objectives/Hypothesis:

Patients with unilateral vocal fold paralysis (UVFP) treated with temporary injection laryngoplasty (IL) have a decreased rate of permanent medialization laryngoplasty (ML) compared to UVFP patients initially treated by observation. The aim of this study was to determine whether the lower rate of ML corresponded with improved quantifiable measures.

Study Design:

Retrospective review.

Methods:

Examinations at presentation and follow‐up of 14 IL patients and 24 observation patients were analyzed for laryngoscopic features and Consensus Auditory‐Perceptual Evaluation of Voice (CAPE‐V) scores.

Results:

The groups were similar at presentation. At follow‐up, the IL group showed significant improvement in 11/18 laryngoscopic criteria and 7/12 CAPE‐V parameters compared to the observation group (P < .05). The observation group underwent ML more frequently than the IL group (75% vs. 29%, P = .008).

Conclusions:

The lower rate of permanent ML in patients undergoing temporary IL corresponds with improvements in CAPE‐V scores and laryngoscopic features. Improvements persisted beyond the accepted time frame for temporary graft resorption. Laryngoscope, 2012
Endoscopic sandwich technique for moderate nasal septal perforations
Authors: Chen Feng‐Hong , Rui Xu , Deng Jie , Wen Yi‐Hui , Xu Geng , Shi Jian‐Bo
Published: August 2012

Objectives/Hypothesis:

The aim of this article was to describe our surgical technique for the treatment of nasal septal perforations with diameters of 1 to 2 cm.

Study Design:

Retrospective clinical research.

Methods:

We reviewed 13 patients with moderate nasal septal perforations (1–2 cm diameter) treated with a sandwich technique (bone or cartilage and quadriceps fascia graft as an interposition graft) by an endoscope‐assisted intranasal approach from January 2008 to June 2011. Follow‐up periods were 3 months.

Results:

Thirteen patients were treated with the sandwich technique. Twelve cases (92.3%) were completely healed. One case received incomplete closures without any postoperative symptoms. All patients were found not to have any complications after surgery.

Conclusions:

The transnasal endoscopic sandwich technique for repairing moderate nasal septal perforation (1–2 cm) has a high success rate and is easy to perform. Laryngoscope, 2012