bluuebunny/crossref_metadata_2025 huggingface dataset:
Local and remote impacts of direct aerosol forcing on Asian monsoon
Authors: Chakraborty Arindam , Nanjundiah Ravi S. , Srinivasan J.
Published: October 2013

The impact of heating by black carbon aerosols on Indian summer monsoon has remained inconclusive. Some investigators have predicted that black carbon aerosols reduce monsoon rainfall while others have argued that it will increase monsoon rainfall. These conclusions have been based on local influence of aerosols on the radiative fluxes. The impact of aerosol‐like heating in one region on the rainfall in a remote region has not been examined in detail. Here, using an atmospheric general circulation model, it has been shown that remote influence of aerosol‐like heating can be as important as local influence on Indian summer monsoon. Precipitation in northern Arabian Sea and north‐west Indian region increased by 16% in June to July when aerosol‐like heating were present globally. The corresponding increase in precipitation due to presence of aerosol‐like heating only over South Asia (local impact) and East Asia (remote impact) were 28 and 13%, respectively. This enhancement in precipitation was due to destabilization of the atmosphere in pre‐monsoon season that affected subsequent convection. Moreover, pre‐monsoon heating of the lower troposphere changed the circulation substantially that enabled influx of more moisture over certain regions and reduced the moist static stability of the atmosphere. It has been shown that regional aerosol heating can have large impact on the phase of upper tropospheric Rossby wave in pre‐monsoon season, which acts as a primary mechanism behind teleconnection and leads to the change in precipitation during monsoon season. These results demonstrate that changes in aerosol in one region can influence the precipitation in a remote region through changes in circulation.
The strengthening relationship between Arctic Oscillation and ENSO after the mid‐1990s
Authors: Li Fei , Wang Huijun , Liu Jiping
Published: October 2013

ABSTRACT

The Arctic Oscillation (AO) and ENSO have dominant influences on the extratropical and tropical climate variabilities in the Northern Hemisphere, respectively. In this paper, we document a strengthening of the AO–ENSO relationship in January after the mid‐1990s, when the interannual variability of the previous September Arctic sea ice cover (ASIC) had consistently increased, by analyzing the AO, ENSO, and associated atmosphere–ocean variability. Our analysis further suggests that the larger ASIC interannual variability may account for the larger scale wave train across the Pacific basin, and the AO is strongly coupled to the circulation in the North Pacific. The strengthened connection between the −AO and Aleutian Low (AL) may contribute to the identified closer relationship between the −AO and ENSO.
Predicting wear and blood metal ion levels in metal‐on‐metal hip resurfacing
Authors: Matthies Ashley K. , Henckel Johann , Cro Suzie , Suarez Alexander , Noble Philip C. , Skinner John , Hart Alister J.
Published: October 2013

Suboptimal component position and design are thought to lead to edge wear and raised blood metal ion levels in metal‐on‐metal hip resurfacing (MOM‐HR). These factors are thought to influence the “contact patch to rim distance” (CPRD), and calculation of this distance may improve prediction of wear and blood metal ion levels. We measured blood cobalt and chromium ion levels and the wear rates of the bearing surfaces in 165 MOM‐HR retrieval cases. We then determined the contribution and effect sizes of cup inclination and version angles, component size and design, and CPRD (calculated from case‐specific data) on blood metal ion levels and component wear rates. Acetabular orientation explained between 16.3% and 28.5% of the variation in wear rates and metal ion levels, whereas component size and design explained between 7.3% and 21.8% of the variability. In comparison, CPRD explained up to 67.7% of the variability, significantly greater than any other variable (all p < 0.0001). CPRD is a good predictor of wear and improves our understanding of wear performance and the mechanisms leading to edge loading. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:167–174, 2014.
Increasing platelet concentration in platelet‐rich plasma inhibits anterior cruciate ligament cell function in three‐dimensional culture
Authors: Yoshida Ryu , Cheng Mingyu , Murray Martha M.
Published: October 2013

Tissue engineering is one new strategy being developed to treat ACL ruptures. One such approach is bio‐enhanced ACL repair, where a suture repair is supplemented with a bio‐active scaffold containing platelets. However, the optimal concentration of platelets to stimulate ACL healing is not known. We hypothesized that increasing platelet concentrations in the scaffold would enhance critical cell behaviors. Porcine ACL fibroblasts were obtained from explant culture and suspended in platelet poor plasma (PPP), 1× platelet‐rich plasma (PRP), 3× PRP, 5× PRP, or phosphate buffered saline (PBS). The cell suspensions were cultured in a 3D collagen scaffold. Cellular metabolism (MTT assay), apoptosis (TUNEL assay), and gene expression for type I and type III collagen were measured. 1× PRP significantly outperformed 5× PRP in all parameters studied: Type I and III collagen gene expression, apoptosis prevention, and cell metabolism stimulation. ACL fibroblasts cultured with 1× PRP had the highest type I and type III collagen gene expression. 1× PRP and PPP groups had the highest cell metabolism and lowest apoptosis rates. Concentration of platelets had significant effects on the behavior of ACL fibroblasts; thus, it is an important parameter that should be specified in clinical or basic science studies. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:291–295, 2014.
Release of growth factors from a reinforced collagen GAG matrix supplemented with platelet rich plasma: Influence on cultured human meniscal cells
Authors: Howard Daniel , Shepherd Jenny H. , Kew Simon J. , Hernandez Paula , Ghose Siddhartha , Wardale John A. , Rushton Neil
Published: October 2013

Damage to meniscal cartilage has been strongly linked to accelerated articular wear and consequently to osteoarthritis. Damage might be ameliorated by delivery of growth factors from platelet rich plasma (PRP) via a fiber reinforced collagen matrix designed for meniscal repair. PRP composition, release of growth factors, and influence on meniscal cell growth and gene expression were investigated. PRP was prepared using Harvest Smartprep (HS‐PRP), Cascade Fibrinet (CF‐PRP), and a simple centrifuge protocol (DC‐PRP) from four donors each. CF‐PRP had the highest ratio of platelets, with very few other blood cell types. HS‐PRP had the highest total number of platelets but also contained high levels of red and white blood cells. Absorbed to collagen matrices HS‐PRP released the highest levels of TGF‐β1 and PDGF‐AB with DC‐PRP the most IGF‐1. Cumulative release from collagen matrix was 48 ng/cm3IGF‐1, 96 ng/cm3TGF‐β1, and 9.6 ng/cm3PDGF‐AB. Collagen matrix with PRP was able to increase meniscal cell number above peripheral whole blood and up‐regulated gene expression of Aggrecan, Collagen type I (α1), and Elastin (3.3 ± 0.8‐fold, 2.9 ± 0.6‐fold, 4.0 ± 1.4‐fold, respectively). Demonstrating that PRP combined with fiber reinforced collagen matrix could influence meniscal cells and might be of use for treating meniscal defects. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:273–278, 2014.
Biomechanical comparison of fixed‐ and mobile‐bearing for unicomparmental knee arthroplasty using finite element analysis
Authors: Kwon Oh‐Ryong , Kang Kyoung‐Tak , Son Juhyun , Kwon Sae‐Kwang , Jo Seung‐Bae , Suh Dong‐Suk , Choi Yun‐Jin , Kim Ho‐Joong , Koh Yong‐Gon
Published: October 2013

Unicomparmental knee arthroplasty (UKA) is a popular alternative to total knee arthroplasty (TKA) and high tibial osteotomy for unicompartmental knee conditions, especially in young patients. However, failure of UKA occurs due to either progressive osteoarthritis (OA) in the other compartment or wear on the polyethylene (PE) insert. This study used finite element (FE) analysis to investigate the effects of PE insert contact pressure and stress in opposite compartments for fixed‐ and mobile‐bearing UKA. Analysis was performed using high kinematics displacement and rotation inputs, which were based on the kinematics of the natural knee. ISO standards were used for axial load and flexion. The mobile‐bearing PE insert had lower contact pressure than the fixed‐bearing PE insert. With the mobile‐bearing UKA, lower stress on the opposite compartment reduces the overall risk of progressive OA in the knee. The fixed‐bearing UKA increases the overall risk of progressive OA in the knee due to higher stress on the opposite compartment. However, the PE insert of mobile‐bearing showed pronounced backside stress at the inferior surface. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:338–345, 2014.
The role of water and mineral–collagen interfacial bonding on microdamage progression in bone
Authors: Luo Qing , Leng Huijie , Wang Xiaodu , Zhou Yanheng , Rong Qiguo
Published: October 2013

Microdamage would be accumulated in bone due to high‐intensity training or even normal daily activity, which may consequently cause fragility fracture or stress fracture. On the other hand, microdamage formation serves as a toughening mechanism in bone. However, the mechanisms that control microdamage initiation and accumulation in bone are still poorly understood. Our previous finite element model indicated that different interfacial properties between mineral and collagen in bone may lead to distinct patterns of microdamage accumulation. Therefore, the current study was designed to examine such prediction and to investigate the role of water and mineral–collagen interactions on microdamage accumulation in bone. To address these issues, 48 mice femurs were divided randomly into four groups. These groups were dehydrated or treated with perfluorotripropylamine (PFTA) or NaF solution to change water distribution and mineral–collagen interfacial bonding in bone. After three‐point bending fatigue tests, the types of microdamage (i.e., linear microcracks or diffuse damage) formed in bone were compared between different groups. The results suggested that (1) bone tissues with strong mineral–collagen interfacial bonding facilitate the formation of linear microcraks, and (2) water has little contribution to the growth of microcracks. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:217–223, 2014.
Partitioning of carbon and nitrogen during decomposition of 13C15N‐labeled beech and ash leaf litter
Authors: Langenbruch Christina , Helfrich Mirjam , Joergensen Rainer Georg , Gordon Jennifer , Flessa Heinz
Published: October 2013

The aim of this study was to determine the influence of leaf‐litter type (i.e., European beech—Fagus sylvatica L. and European ash—Fraxinus excelsior L.) and leaf‐litter mixture on the partitioning of leaf‐litter C and N between the O horizon, the topsoil, the soil microbial biomass, and the CO2 emission during decomposition. In a mature beech stand of Hainich National Park, Thuringia, Germany, undisturbed soil cores (∅︁ 24 cm) were transferred to plastic cylinders and the original leaf litter was either replaced by 13C15N‐labeled beech or ash leaf litter, or leaf‐litter‐mixture treatments in which only one of the two leaf‐litter types was labeled. Leaf‐litter‐derived CO2‐C flux was measured every second week over a period of one year. Partitioning of leaf‐litter C and N to the soil and microbial biomass was measured 5 and 10 months after the start of the experiment. Ash leaf litter decomposed faster than beech leaf litter. The decomposition rate was negatively related to initial leaf‐litter lignin and positively to initial Ca concentrations. The mixture of both leaf‐litter types led to enhanced decomposition of ash leaf litter. However, it did not affect beech leaf‐litter decomposition. After 5 and 10 months of in situ incubation, recoveries of leaf‐litter‐derived C and N in the O horizon (7%–20% and 9%–35%, respectively) were higher than in the mineral soil (1%–5% and 3%–8%, respectively) showing no leaf‐litter‐type or leaf‐litter‐mixture effect. Partitioning of leaf‐litter‐derived C and N to microbial biomass in the upper mineral soil (< 1% of total leaf‐litter C and 2%–3% of total leaf‐litter N) did not differ between beech and ash. The results show that short‐term partitioning of leaf‐litter C and N to the soil after 10 months was similar for ash and beech leaf litter under standardized field conditions, even though mineralization was faster for ash leaf litter than for beech leaf litter.
Early to mid‐Holocene rapid sea‐level rise and coastal response on the southern Yangtze delta plain, China
Authors: WANG ZHANGHUA , ZHAN QING , LONG HAIYAN , SAITO YOSHIKI , GAO XIAOQIN , WU XUXU , LI LIN , ZHAO YANAN
Published: October 2013

We used accelerator mass spectrometry (AMS) 14C‐dated sediments of the Holocene basal supratidal flat to upper tidal flat facies in 11 cores on the southern Yangtze delta plain to reconstruct relative sea levels of 8.5–8.0 cal ka BP. Three cores were further AMS 14C dated and used to examine the evolution of sedimentary geomorphological environments in response to the rapid sea‐level rise during the early to mid‐Holocene. Results demonstrate relative sea‐level rise of around 30 mm a−1 from 8.5 to 8.3 cal ka BP and around 10 mm a−1 from 8.3 to 8.0 cal ka BP. Retrogradation from supratidal to lower tidal flat environments occurred in response to the rapid sea‐level rise at 8.5–8.3 cal ka BP, and aggradation from middle to upper tidal flat occurred at 8.3–7.9 cal ka BP. Further retreat of the tidal flat at 7.9–7.2 cal ka BP implies a mean sea‐level rise rate exceeding 5 mm a−1 at this time. We suggest that the rapid relative sea‐level rise during 8.3–8.5 cal ka BP and subsequent slower rise caused drastic changes in the coastal zone and that these changes are key phenomena for understanding the coastal response to future sea‐level rise.
Detection of the potential tumor marker of AFP using surface‐enhanced Raman scattering‐based immunoassay
Authors: Wang Aijing , Ruan Weidong , Song Wei , Chen Lei , Zhao Bing , Jung Young Mee , Wang Xu
Published: October 2013

The development of rapid, highly sensitive detection methods for α‐fetoprotein (AFP) is very important. As hepatocellular carcinoma is closely related to the level of AFP in the blood, it is necessary to maintain an AFP concentration below the safety limit. In this paper, we propose a universal, rapid, sensitive, and highly specific immunoassay system utilizing gold nanoparticles (AuNPs) and surface‐enhanced Raman scattering (SERS). This new system features a sandwich structure combining mercaptobenzoic acid‐labeled immunogold nanoparticles with the antigen and the antibody atop a pre‐designed substrate made of a glass slide modified with AuNPs. This SERS‐based immunoassay can detect AFP concentrations as low as 100 pg/ml, which is a significant improvement on the capabilities of the enzyme‐linked immunosorbent assay method. A good linear relationship between the SERS peak intensity and the logarithm of antigen concentrations (from 1 ng/ml to 100 ng/ml) was observed. This technique provides an effective model for the detection of biomarkers in medical diagnostics, criminal investigation, and other fields. Copyright © 2013 John Wiley & Sons, Ltd.
Identification of volatile compounds associated with the aroma of white strawberries (Fragaria chiloensis)
Authors: Prat Loreto , Espinoza María Inés , Agosin Eduardo , Silva Herman
Published: October 2013

BACKGROUND

Fragaria chiloensis (L.) Mill spp. chiloensis form chiloensis, is a strawberry that produces white fruits with unique aromas. This species, endemic to Chile, is one of the progenitors of Fragaria x ananassa Duch. In order to identify the volatile compounds that might be responsible for aroma, these were extracted, and analyzed by gas chromatography–mass spectrometry (GC‐MS), gas chromatography–olfactometry (GC‐O) and compared with sensory analyses.

RESULTS

Three methods of extraction were used: solvent‐assisted evaporation (SAFE), headspace solid phase micro‐extraction (HS‐SPME) and liquid–liquid extraction (LLE). Ninety‐nine volatile compounds were identified by GC‐MS, of which 75 showed odor activity using GC‐O. Based on the highest dilution factor (FD = 1000) and GC‐O intensity ≥2, we determined 20 major compounds in white strawberry fruit that contribute to its aroma. We chose 51 compounds to be tested against their commercial standards. The identities were confirmed by comparison of their linear retention indices against the commercial standards. The aroma of white strawberry fruits was reconstituted with a synthetic mixture of most of these compounds.

CONCLUSION

The volatile profile of white strawberry fruit described as fruity, green–fresh, floral, caramel, sweet, nutty and woody will be a useful reference for future strawberry breeding programs. © 2013 Society of Chemical Industry
Effect of fish oil and linseed supplementation on the protein composition of milk from cows with different β‐lactoglobulin phenotypes
Authors: Puppel Kamila , Kuczyńska Beata , Nałęcz‐Tarwacka Teresa , Sakowski Tomasz , Gołębiewski Marcin , Kunowska‐Slósarz Małgorzata , Budziński Arkadiusz , Grodzki Henryk
Published: October 2013

BACKGROUND

The objective of this study was to determine the impact of fish oil and linseed (FOL) supplements on the protein fraction levels of milk from cows with different phenotypes of β‐lactoglobulin.

RESULTS

After 21 days of supplementation the study showed significantly higher concentrations of whey proteins, especially lysozyme (144% increase) and lactoferrin (45.5% increase), compared with milk from control cows (total mixed ration with no supplemented FOL). A reverse trend was demonstrated for casein, casein index and casein number (lower level). The most favourable change (higher level), in terms of lactoferrin, α‐lactalbumin and bovine serum albumin contents in milk, was recorded in cows with the BB variant of β‐lactoglobulin. The highest level of lysozyme was recorded in the milk of cows with the AB variant of β‐lactoglobulin.

CONCLUSION

The combined supplementation of fish oil and linseed had a positive impact on whey proteins in cow's milk. In addition, the phenotype of β‐lactoglobulin also played a role in milk protein composition. There is therefore a clear indication that nutritional experiments should take into account not only food supplements but also the genetic variants of β‐lactoglobulin. © 2013 Society of Chemical Industry
Microbiological quality of raw and processed wild and cultured edible snails
Authors: Parlapani Foteini F , Neofitou Christos , Boziaris Ioannis S
Published: October 2013

BACKGROUND

An increasing interest in snail farming in Greece and other European countries has been observed. Despite the fact that edible snails have been involved with problems of Salmonella spp. contamination, there are to our knowledge only limited studies regarding microbiological safety and hygiene of such products. Enumeration of microbial populations and presence/absence of Salmonella spp. in snail meat and intestines of wild Cornu aspersum, Helix lucorum and cultured Cornu aspersum snails from indoor/outdoor type farms was conducted. Furthermore, snail‐processing steps were simulated in the laboratory and the population reduction in snail meat was determined.

RESULTS

Microbial populations were higher in intestines than snail meat in almost all cases. Escherichia coli/coliforms and Enterococcus spp. populations were lower in the intestines and snail meat of cultured C. aspersum. Salmonella spp. were detected in the intestines and snail meat of wild snails only. The high levels of bacterial populations were considerably reduced after the appropriate processing.

CONCLUSION

The lower populations of E. coli/coliforms, Enterococcus spp. and especially the absence of Salmonella spp. in cultured snails show that the controlled conditions decrease the possibility of pathogen presence and contribute to food safety and public health. © 2013 Society of Chemical Industry
Changes of DNA quality and meat physicochemical properties in bovine supraspinatus muscle during microwave heating
Authors: Musto Mauro , Faraone Daniela , Cellini Francesco , Musto Elisa
Published: October 2013

BACKGROUND

The responses of foods to microwave exposure are usually evaluated only in terms of physicochemical properties, thus undervaluing the importance of DNA in an authentication process by methods based on polymerase chain reaction (PCR). In this study, the time effect of microwave heating on some meat physicochemical properties and DNA quality has been investigated.

RESULTS

Cooking loss, instrumental colour, pH and other physicochemical parameters varied significantly during microwave cooking, reaching the lowest/highest values after 2.5 min of cooking. The exposure of meat to microwaves was found to affect characteristically the quality of extracted DNA (i.e. yield, purity and degradation). PCR products of both mitochondrial and nuclear regions were successfully observed in all samples. However, the band for large fragments became progressively fainter as treatment time increased.

CONCLUSIONS

Microwave heating caused physicochemical changes in bovine supraspinatus muscle and influenced characteristically the yield and integrity of the extracted DNA, indicating that an accurate DNA quantification and a rational choice of the genes (i.e. mtDNA versus nDNA, fragment size, etc.) to be amplified are fundamental in an authentication process by PCR‐based methods. © 2013 Society of Chemical Industry
Surgical management of non‐colorectal hepatic metastasis
Authors: Tan Marcus C.B. , Jarnagin William R.
Published: October 2013

Isolated hepatic metastases from non‐colorectal primary tumors are rare. Patients with neuroendocrine tumors have an indolent biology compared with other non‐colorectal histologies. This article discusses the surgical management options for patients with neuroendocrine liver metastases and, separately, for those with non‐colorectal, non‐neuroendocrine metastases. Emphasis is placed on the importance of patient selection, understanding the tumor biology and response to systemic therapy. J. Surg. Oncol. 2014 109:8–13. © 2013 Wiley Periodicals, Inc.
Intraperitoneal chemotherapy (IPC) for peritoneal carcinomatosis: Review of animal models
Authors: Gremonprez Félix , Willaert Wouter , Ceelen Wim
Published: October 2013

The development of suitable animal models is essential to experimental research on intraperitoneal chemotherapy (IPC). This review of the English literature (MEDLINE) presents a detailed analysis of current animal models and gives recommendations for future experimental research. Special consideration should be given to cytotoxic drug dose and concentration, tumor models, and outcome parameters. J. Surg. Oncol. 2014 109:110–116. © 2013 Wiley Periodicals, Inc.
Purification of hen egg white ovomacroglobulin using one‐step chromatography
Authors: Geng Fang , Huang Xi , Yan Nannan , Jia Lili , Ma Meihu
Published: October 2013

Hen egg white (EW) are one of the most ideal sources of active proteins, and ovomacroglobulin, as a protease inhibitor, has been demonstrated to possess numerous biological properties including antibacterial and anti‐inflammatory properties as well as activity for the treatment of keratitis. The objective of this study was to develop a simple and rapid method for the purification of ovomacroglobulin from hen EW on a laboratory scale. Hen EW was diluted with an equal volume of distilled water followed by a two‐step PEG precipitation to remove ovomucin and to obtain ovomacroglobulin‐rich precipitate. The precipitate was dissolved and further purified by gel filtration chromatography. Ovomacroglobulin was collected with a purity of 97.0 ± 0.3% by HPLC and a yield of 62.5%. The atomic force microscopy images showed that ovomacroglobulin molecules on a mica surface emerged as an “oval‐shaped plate” with a molecular volume of 1536.9 ± 330.0 nm3, indicating that purified ovomacroglobulin has an integrated molecular structure. With the improvement of PEG precipitation and the simplification of the chromatography, the whole purification process could be finished well within one working day. This protocol has an advantage of rapidity, and would facilitate studies of ovomacroglobulin.
Simultaneous determination of four aflatoxins and ochratoxin A in ginger and related products by HPLC with fluorescence detection after immunoaffinity column clean‐up and postcolumn photochemical derivatization
Authors: Wen Jing , Kong Weijun , Wang Jian , Yang Meihua
Published: October 2013

Ginger, a widely used spice and traditional Chinese medicine, is prone to be contaminated by mycotoxins. A simple, sensitive, and reproducible method based on immunoaffinity column clean‐up coupled with HPLC and on‐line postcolumn photochemical derivatization with fluorescence detection was developed for the simultaneous determination of aflatoxins (AFs) B1, B2, G1, G2, and ochratoxin A (OTA) in 25 batches of gingers and related products marketed in China for the first time. The samples were first extracted by ultrasonication with methanol/water (80:20, v/v) and then cleaned up with immunoaffinity columns for analysis. Under the optimized conditions, the LODs and LOQs for the five mycotoxins were 0.03–0.3 and 0.1–0.9 μg/kg, respectively. The average recoveries ranged from 81.3–100.8% for AFs and from 88.6–99.5% for OTA at three spiking levels. Good linearity was observed for the analytes with correlation coefficients all >0.9995. All moldy gingers were contaminated with at least one kind of the five investigated mycotoxins, while none of them were found in normal gingers. Ginger powder samples were contaminated slightly with the contamination levels below the LOQs, while ginger tea bags were mainly contaminated by OTA at 1.05–1.19 μg/kg and ginger black tea bags were mainly contaminated by AFs at 3.37–5.76 μg/kg. All the contamination levels were below the legally allowable limits.
Simultaneous quantification of energetically important metabolites in various cell types by CZE
Authors: Musilová Jindra , Klejdus Bořivoj , Glatz Zdeněk
Published: October 2013

A new CZE method was developed for the determination of 12 purine and pyrimidine nucleotides, two adenine coenzymes and their reduced forms, and acetyl coenzyme A in various cell extracts. As the concentration levels of these metabolites in living cells are low; CZE was combined with field‐enhanced sample stacking. As a result, the separation conditions were optimised to achieve a suitable resolution at the relatively high sample volume provided by this on‐line pre‐concentration technique. The optimum BGE was 150 mM glycine buffer (pH 9.5). Samples were introduced hydrodynamically using a pressure of 35 mbar (3.5 kPa) for 25 s, and data were collected at a detection wavelength of 260 nm. An applied voltage of 30 kV (positive polarity) and capillary temperature of 25°C gave the best separation of these compounds. The optimised method was validated by determining the linearity, sensitivity and repeatability and it was successfully applied for the analysis of extracts from Paracoccus denitrificans bacteria and from stem cells.
Kinetic Studies of the Ligand Substitution Reaction of Some New Uranyl Schiff Base Complexes with Tri‐n‐butylphosphine
Authors: Asadi Zahra , Asadi Mozaffar , Firuzabadi Fahimeh Dehghani
Published: October 2013

Kinetics of the substitution reaction of solvent molecule in uranyl(VI) Schiff base complexes by tri‐n‐butylposphine as the entering nucleophile in acetonitrile at 10–40°C was studied spectrophotometrically. The second‐order rate constants for the substitution reaction of the solvent molecule were found to be (8.8 ± 0.5) × 10−3, (5.3 ± 0.2) × 10−3, (7.5 ± 0.3) × 10−3, (6.1 ± 0.3) × 10−3, (13.5 ± 1.6) × 10−3, (13.2 ± 0.9) × 10−3, (52.9 ± 0.2) × 10−3, and (88.1 ± 0.6) × 10−3 M−1 s−1 at 40°C for [UO2(Schiff base)(CH3CN)], where Schiff base = L1–L8, respectively. In a temperature dependence study, the activation parameters ΔH# and ΔS# for the reaction of uranyl complexes with PBu3 were determined. From the linear rate dependence on the concentration of PBu3, the span of k2 values and the large negative values of the activation entropy, an associative (A) mechanism is deduced for the solvent substitution. By comparing the second‐order rate constants k2, it was concluded that the steric and the electronic properties of the complexes were important for the rate of the reactions.
Oxidation and Destruction of Polyvinyl Alcohol in the Aqueous Phase
Authors: Zimin Yu. S. , Borisov I. M. , Borisova N. S. , Mustafin A. G.
Published: October 2013

We have studied kinetic laws of polyvinyl alcohol oxidation under the action of an ozone–oxygen mixture and hydrogen peroxide in an aqueous medium. It is shown that polymer oxidation is carried out by the radical mechanism. The scheme of oxidative transformations of polyvinyl alcohol explaining the obtained results is suggested.
Cetyltrimethylammonium Bromide as an Efficient Catalyst for Regioselective Bromination of Alkoxy Naphthalenes with Trimethyl Benzyl Ammonium Tribromide: Synthetic and Kinetic Approach
Authors: Reddy K. Rajendar , Rajanna K. C. , Uppalaiah K. , Ramgopal S.
Published: October 2013

Bromination of 2‐alkoxynaphthalene (2‐ANP) and its derivatives with trimethyl benzyl ammonium tribromide (TMBATB) did not proceed smoothly even under reflux conditions. But the addition of microconcentrations of cetyltrimethyl ammonium bromide (CTAB) to the reaction afforded dramatic rate accelerations as well as good‐to‐excellent yield of the products ranging from 70% to 90%. Reactions underwent regioselective monobromination at 1‐position of 2‐alkoxynaphthalene. The rate of bromination has been followed conductometrically. The reaction kinetics indicated first‐order kinetics in [2‐ANP] as well as in [TMBATB]. Kinetic results in the presence of CTAB were explained on the basis of the Raghavan–Srinivasan model as applied to micelle‐mediated bimolecular reactions.
Transesterification Kinetics Investigation of R‐Substituted Phenyl Benzoates with 4‐Methoxyphenol in the Presence of K2CO3 in DMF
Authors: Os'kina Irina A.
Published: October 2013

Transesterification of R‐substituted phenyl benzoates 1–5 with 4‐methoxyphenol 6 was kinetically investigated in the presence of K2CO3 in dimethylformamide (DMF) at various temperatures. The Hammett plots for the reactions of the 1–5 demonstrate good linear correlations with σ0 constants. Low magnitude of ρLG values indicate that the leaving group departure occurs after the rate‐determining step. The Brønsted coefficient values for the reactions (−0.2, −0.16, −0.13 at 15, 24, 36°C, respectively) demonstrate the weak effect of leaving group substituent on the reactivity of R‐substituted phenyl benzoates 1–5 for the reactions with 4‐methoxyphenol 6 in the presence of K2CO3 in DMF. The leaving group substituent effect on free energy (ΔG≠), enthalpy (ΔH≠), and entropy (ΔS≠) of activation was examined. It was shown that the activation parameters obtained depend weakly on the leaving group substituent effect. The reaction is entropy controlled in case the leaving group substituent becomes electron withdrawing.
Achievement of competency in endoscopic sinus surgery of otolaryngology residents
Authors: Laeeq Kulsoom , Lin Sandra Y. , Varela David A. Diaz Voss , Lane Andrew P. , Reh Douglas , Bhatti Nasir I.
Published: October 2013

Objectives/Hypothesis

The goal of our study is to identify the number of Endoscopic Sinus Surgery (ESS) cases required to obtain competency in ESS, using a previously validated assessment tool.

Study Design

Prospective observational study.

Methods

Seventeen residents from Johns Hopkins Otolaryngology–Head & Neck Surgery residency program were evaluated as they performed endoscopic sinus surgery in the operating room. Global and checklist parts of the ESS instrument were used for assessment purposes. Items on the tool were grouped into three different milestones for analysis of data (Milestone 1 = Maxillary Antrostomy + Anterior Ethmoidectomy, Milestone 2 = Posterior Ethmoidectomy + Sphenoidostomy, Milestone 3 = Frontal Sinusotomy). Residents were deemed competent if they achieved a minimum score of 3 on a 5‐point Likert scale on each step of the surgery.

Results

A total of 73 evaluations were completed for 17 residents (Postgraduate Level 2–5) by eight evaluators between 2009 and 2011. A 60% probability of achieving competency in performance of all milestones of ESS is obtained with performing 42 ESS procedures and the probability is increased to a 100% with performance of 55 endoscopic sinus surgery procedures. On average it took residents 23 cases to become competent in performance of maxillary antrostomy and anterior ethmoidectomy.

Conclusions

Our results suggest that it requires 42 ESS procedures to attain a 60% probability of competency in ESS. These results have implications for otolaryngology residency programs when developing curriculum and benchmarks for the training residents. Laryngoscope, 123:2932–2934, 2013
Interarytenoid botulinum toxin injection for recalcitrant vocal process granuloma
Authors: Fink Daniel S. , Achkar Jihad , Franco Ramon A. , Song Phillip C.
Published: October 2013

Objectives/Hypothesis

This study evaluated the efficacy of botulinum toxin type A injected into the interarytenoid muscle to treat recalcitrant vocal process granulomas.

Study Design

Retrospective clinical review at a tertiary care center.

Methods

Eight patients with vocal process granulomas refractory to a variety of prior treatments including surgical resection, proton pump inhibitor therapy, and voice therapy underwent percutaneous injection of botulinum toxin type A into the interarytenoid muscle, performed in an office setting. Doses ranged from 5 U to 25 U in one to two injections.

Results

One patient demonstrated no improvement, two patients demonstrated partial resolution, and five patients demonstrated complete resolution of their granulomas. Four patients noted transient breathiness. There were no other side effects. All patients tolerated the injections without difficulty.

Conclusion

Botulinum toxin injection into the interarytenoid muscle appears to be a safe and effective modality for treating recalcitrant vocal process granuloma. Laryngoscope, 123:3084–3087, 2013
Pharyngotracheal fistula closure using the internal mammary artery perforator island flap
Authors: Mirghani Haïtham , Leymarie Nicolas , Amen Furrat , Qassemyar Quentin , Leclère Franck Marie , Kolb Frederic
Published: October 2013

Objectives/Hypothesis

Salvage laryngectomy following organ preservation therapy is a frequent condition that exposes patients to pharyngocutaneous and pharyngotracheal fistulas. Definitive treatment frequently requires well vascularized tissue harvested from the chest. To limit tracheostoma obstruction, a thin and pliable flap is preferable. The internal mammary artery perforator (IMAP) island flap fulfills these criteria, but it is not well known and is not commonly used by head and neck surgeons. In this article, based on our experience, we describe our surgical technique and the strengths and weaknesses of this flap.

Study Design

Retrospective cohort study and systematic review of the literature.

Methods

An IMAP flap was performed on 12 patients to repair postoperative fistulas, located in the lower neck close to the tracheal stoma or involving the posterior tracheal wall, from March 2009 to December 2012. The medical records of each of patient were retrospectively analyzed.

Results

A breach of the pleura occurred in one patient. It was diagnosed and treated perioperatively. One patient had a total flap necrosis and required a reoperation. The postoperative course was uneventful in 11 patients (92%). All donor sites were closed primarily without any wound‐healing problems.

Conclusions

The IMAP flap is reliable. Its advantages make it a convenient flap to repair peritracheostomal defects and fistulas. The harvesting technique is not very demanding but requires training.

Level of Evidence

4. Laryngoscope, 124:1106–1111, 2014
Resource analysis of tonsillectomy in children
Authors: Shah Udayan K. , Theroux Zachary , Shah Gopi B. , Parkes William J. , Schuck Christine
Published: October 2013

Objectives/Hypothesis

To analyze variables that affect time and cost parameters of pediatric adenotonsillectomy.

Study Design

Longitudinal 7‐month retrospective review of sequential tonsil and adenoid surgery at a university pediatric tertiary care hospital.

Methods

All children aged 2 to 12 years who underwent adenotonsillectomy from May 2008 to October 2008 had charts and billing records analyzed for variations in charges and times of adenotonsillectomy according to patient age, body mass index for age (BMIFA), American Society of Anesthesiologists (ASA) status, surgical indication, technology used, and teaching status of case. A total of 214 children had records reviewed.

Results

Statistically significant variations were observed for all measured parameters except for indications for surgery. Children 3 years and younger had shorter procedures (P = .005) and total operating room times (P = .037). Charges for supplies were lower for ASA 1 patients than for ASA 2 patients (P = .010). Obese children with elevated BMIFA required longer procedures (P = .039) and more expensive surgery (P = .003). Procedure times were shorter for Coblation (ArthroCare, Austin, TX) compared with electrocautery (P = .27) and for microdebrider compared with electrocautery (P < .001). Charges for Coblation were substantially higher (P < .001). Teaching cases took longer (P < .001).

Conclusions

Charges and times for adenotonsillectomy surgery varied by patient age, BMIFA, ASA status, tonsillectomy technique, and teaching case status. Clinically salient differences were noted for ASA status, BMIFA, and surgical technique. This method of cost analysis provides useful information for resource management in tonsillectomy.

Level of Evidence

2c. Laryngoscope, 124:1223–1228, 2014
The relationship of the natural sphenoid ostium to the skull base
Authors: Halawi Akaber M. , Simon Patrick E. , Lidder Alcina K. , Chandra Rakesh K.
Published: October 2013

Objectives/Hypothesis

Various intranasal landmarks have been described to aid in the localization of the natural sphenoid sinus ostium. The objectives of this study are to identify the ostium location relative to the skull base and assess the relationships between the location of the ostium and sphenoid disease or pneumatization pattern.

Design

Descriptive study.

Methods

Consecutive Xoran Mini‐CAT (Ann Arbor, MI) scans of patients with no history of sinus surgery (n = 202) were evaluated. The natural sphenoid ostium was identified in axial, coronal, and sagittal planes. Distances from the planum to the ostium and from the planum to the sinus floor were calculated. Lund‐Mackay score and pneumatization pattern were recorded for each sphenoid sinus.

Results

The mean distance from planum to ostium was 11.2 ± 2.6 mm (range 4.4–19.2). On average, this encompassed 45.5% ± 10% of the total sphenoid height. ANOVA with posthoc Tukey analysis revealed that the ostium was closer to the planum in sinuses with sellar (P = 0.05) or presellar (P = 0.02) pneumatization, compared to those with postsellar pneumatization. There was no significant relationship between the ostium location and degree of sinus disease. There was a significant difference in the pneumatization pattern between males and females (P = .04). More males had postsellar pneumatization than expected, and more females had sellar pneumatization than expected.

Conclusions

The natural ostium of the sphenoid sinus is located at approximately the midpoint of the sphenoid face. Nevertheless, significant variability can be observed based on the pneumatization pattern. Surgeons should recognize that the ostium may be closer to the skull base when the sinus is less pneumatized.

Level of Evidence

4. Laryngoscope, 125:75–79, 2015
Round window closure affects cochlear responses to suprathreshold stimuli
Authors: Cai Qunfeng , Whitcomb Carolyn , Eggleston Jessica , Sun Wei , Salvi Richard , Hu Bo Hua
Published: October 2013

Objectives/Hypothesis

The round window acts as a vent for releasing inner ear pressure and facilitating basilar membrane vibration. Loss of this venting function affects cochlear function, which leads to hearing impairment. In an effort to identify functional changes that might be used in clinical diagnosis of round window atresia, the current investigation was designed to examine how the cochlea responds to suprathreshold stimuli following round window closure.

Study Design

Prospective, controlled, animal study.

Methods

A rat model of round window occlusion (RWO) was established. With this model, the thresholds of auditory brainstem responses (ABR) and the input/output (IO) functions of distortion product otoacoustic emissions (DPOAEs) and acoustic startle responses were examined.

Results

Round window closure caused a mild shift in the thresholds of the auditory brainstem response (13.5 ± 9.1 dB). It also reduced the amplitudes of the distortion product otoacoustic emissions and the slope of the input/output functions. This peripheral change was accompanied by a significant reduction in the amplitude, but not the threshold, of the acoustic startle reflex, a motor response to suprathreshold sounds.

Conclusions

In addition to causing mild increase in the threshold of the auditory brainstem response, round window occlusion reduced the slopes of both distortion product otoacoustic emissions and startle reflex input/output functions. These changes differ from those observed for typical conductive or sensory hearing loss, and could be present in patients with round window atresia. However, future clinical observations in patients are needed to confirm these findings.

Level of Evidence

N/A. Laryngoscope, 123:E116–E121, 2013
Longer length baha™ abutments decrease wound complications and revision surgery
Authors: Allis Terah J. , Owen Benjamin D. , Chen Baojiang , Jones Dwight T. , Moore Gary F.
Published: October 2013

Objectives/Hypothesis

To study the complication rates of skin overgrowth, infection, and the need for revision surgery in longer length Baha™ abutments.

Study Design

Prospective observational cohort study compared with a retrospective historical control.

Methods

After the University of Nebraska Medical Center (UNMC) Institutional Review Board approval was obtained, data was collected from a prospective 8.5‐mm abutment study group of 21 subjects with informed consent from October 2011 through October 2012, and was compared to a retrospective 5.5‐mm abutment historical cohort of 23 patients who had undergone Baha™ by the same surgeon from May 2010 to October 2011. Patient demographics, body mass index (BMI), smoking status, and wound complications (skin overgrowth, infection, the need for revision surgery) were statistically investigated and compared between the groups.

Results

Forty‐four patients were studied. The groups were similar in smoking status, diabetes, and a female preponderance. The 8.5‐mm abutment group was older (P = 0.012). The average BMI for both groups was classified as overweight and nearly obese (BMI 28.8). Rates of infection, skin overgrowth, and the need for revision surgery related to wound complications were significantly decreased in the longer 8.5‐mm abutment group (P = 0.020, P = 0.012, P = 0.007, respectively). BMI did not correlate with decreased infection, skin overgrowth, and the need for revision surgery based on abutment length as hypothesized (P = 0.214, P = 0.206, P = 0.408).

Conclusions

The 8.5‐mm abutment lends to decreased complications postoperatively, including infection, skin overgrowth, and the need for revision surgery.

Level of Evidence

3b. Laryngoscope, 124:989–992, 2014
Differences in perception of hearing handicap between cochlear implant users and their spouses
Authors: Mistry Dipan , Ryan Jillian , Maessen Heather , Bance Manohar
Published: October 2013

Objectives/Hypothesis

To examine the relationship between patient and proxy ratings of health‐related quality of life (HRQL) in patients with cochlear implants.

Study Design

Prospective survey.

Methods

Eighty‐two adult cochlear implant recipients and their spouses/partners were asked to complete the Nijmegen Cochlear Implant Questionnaire (NCIQ) and the Hearing Participation Scale (HPS) that were mailed to them.

Results

For the NCIQ, there were 38 useable responses from recipients and 31 useable responses from the partners. There were 27 paired and useable questionnaires (i.e., from both the recipient and his/her partner). For the HPS, there were 42 useable responses from recipients and 36 useable responses from the partners. Of these, there were 35 paired questionnaires. There was good agreement between partners and patients with both the HPS (r = 0.62) and the NCIQ (r = 0.80). There was a significant statistical difference in the scoring of the Basic Sound Perception subscale between the two groups (P = .039), with spouses under‐rating performance in this subscale.

Conclusions

For patients with cochlear implants, patients' partners corroborate patients' self‐reported HRQL. In cases in which patients have sensory impairment, there may be an additional role for proxy ratings of HRQL to give a more complete assessment of functional limitations.

Level of Evidence

4. Laryngoscope, 124:1199–1203, 2014
Excised larynx evaluation of wedge‐shaped adjustable balloon implant for minimally invasive type I thyroplasty
Authors: Hoffman Matthew R. , Devine Erin E. , McCulloch Timothy M. , Jiang Jack J.
Published: October 2013

Objectives/Hypothesis

To describe the method of inserting a wedge‐shaped adjustable balloon implant (wABI) via a minithyrotomy for medialization thyroplasty and evaluate its effect on a range of phonatory parameters using the excised larynx bench apparatus.

Study Design

Repeated measures with each larynx serving as its own control.

Methods

A prototype wABI was deployed in six excised canine larynges of various sizes through a minithyrotomy and then filled with saline. Mucosal wave, aerodynamic, and acoustic parameters were measured for three conditions: normal, vocal fold paralysis, and paralysis with the wABI.

Results

Phonation threshold pressure (P < .001), flow (P < .001), and power (P = .002) were significantly lower for wABI compared to paralysis trials; values did not differ significantly from normal trials. Percent jitter (P = .002) and percent shimmer (P = .007) were also significantly decreased compared to the paralysis condition, and values were not significantly different compared to normal. The mucosal wave was preserved after insertion of the wABI.

Conclusions

Effective vocal fold medialization with preservation of the mucosal wave was observed with the wABI in this preliminary excised larynx experiment. The wABI offers the potential for a minimally invasive insertion in addition to postoperative adjustability. Further studies in living animals and humans are warranted to evaluate clinical utility.

Level of Evidence

NA. Laryngoscope, 124:942–949, 2014