bluuebunny/crossref_metadata_2025 huggingface dataset:
Endonasal repair of septal perforations using a rotational mucosal flap and acellular dermal interposition graft
Authors: Chhabra Nipun , Houser Steven M.
Published: March 2012

Background:

The closure of nasal septal perforations can be challenging based on the etiology, location, and method of closure. We report on a novel method of closure for nasal septal perforations using a unilateral mucosal rotational flap and acellular dermal interposition graft.

Methods:

Twenty patients with nasal septal perforations of various etiologies underwent our method of repair through a closed, endonasal approach.

Results:

Out of 20 patients, 17 demonstrated successful closure of their septal perforations, consistent with an 85% success rate. Based upon size, closure rates were 89% for small perforations (<1 cm), 80% for medium perforations (1‐2 cm), and complete closure for a single large perforation (>2 cm). Of 20 patients, 19 were completely asymptomatic following surgical intervention, and of the 3 with failed repairs, only 1 patient required revision surgery for persistent symptoms.

Conclusion:

Nasal septal perforations may cause bothersome symptoms and present a significant reconstructive challenge. Native septal tissue is advantageous due to a rich vascular supply and proximity to the defect, while interposition grafts act as a scaffold for the migration of respiratory mucosa. The method described herein combines these principles to provide a suitable technique for the closure of nasal septal perforations. ©2012 ARSAAOA, LLC.
Freestanding chemiresistive polymer composite ribbons as high‐flux sensors
Authors: Benz Marcel , Patel Sanjay V.
Published: March 2012

Chemiresistive polymer composite ribbons that function as chemical detectors were produced from solution‐cast films of polymers and carbon composites. An array with multiple polymer sensor threads was exposed to dimethyl methyl phosphonate, a nerve agent simulant, and different interferents in the vapor phase. Principal component analysis was used to differentiate between the analytes. The response of the ribbon sensors as a function of the carbon composite and the host polymer source was investigated. The freestanding threads/sensors were mounted into a cell perpendicular to the gas flow to provide little pressure drop and were imbedded into fabrics to provide an example of a small, low‐cost, wearable chemical sensor. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Correlation of the structure, properties, and antimicrobial activity of a soluble thiolated chitosan derivative
Authors: Han Bing , Wei Yan , Jia Xiaolong , Xu Juan , Li Gang
Published: March 2012

A thiolated chitosan (CS) derivative was synthesized by the introduction of thioglycolic acid to CS via amide‐bond formation mediated by carbodiimide. The chemical structure of the CS derivative was confirmed by Fourier transform infrared spectroscopy and 1H‐NMR spectroscopy. The solubility test showed that the thiolated CS derivative was water‐soluble. The X‐ray pattern of the CS derivative showed an obvious disappearance or shift of crystalline peaks compared to that of CS. Thermogravimetric analysis indicated that the degradation peak temperature of the thiolated CS derivative was much higher than that of CS and implied an improved thermal stability at higher temperatures. Moreover, the antimicrobial activity of the thiolated CS derivative was comparable to that of CS. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Potassium persulfate‐mediated preparation of conducting polypyrrole/polyacrylonitrile composite fibers: Humidity and temperature‐sensing properties
Authors: Acar Handan , Karakışla Meral , Saçak Mehmet
Published: March 2012

Conducting polypyrrole (PPy)/polyacrylonitrile (PAN) composite fibers were prepared by the polymerization of pyrrole in the presence of PAN fibers with potassium persulfate in an acidic aqueous solution. We obtained composite fibers containing concentrations of PPy as high as 1.14% and having surface resistivities as low as 0.6 kΩ/cm2 by changing the polymerization parameters, including the temperature and concentrations of pyrrole and oxidant. The tensile strength of 10.02 N/m2 and breaking elongation of 32.68% for the pure PAN fiber increased up to 10.45 N/m2 and 33.23%, respectively, for the composite fiber containing 0.13% PPy. The change in the resistivity of the PPy/PAN composite fiber during heating–cooling cycles in the temperature range of +5 to 120°C was examined. Scanning electron microscopy and optical microscopy images of the composite fibers showed that the PPy coating was restricted to the surfaces of the PAN fibers. Surface resistivity measurements, Fourier transform infrared spectroscopy, and thermogravimetric analysis techniques were also used to characterize the composite fibers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Surface modification of PVDF membranes with sulfobetaine polymers for a stably anti‐protein‐fouling performance
Authors: Li Qian , Zhou Bo , Bi Qiu‐Yan , Wang Xiao‐Lin
Published: March 2012

Two sulfobetaine‐based zwitterionic monomers, including 3‐(methacryloylamino) propyl‐dimethyl‐(3‐sulfopropyl) ammonium hydroxide (MPDSAH) and 2‐(methacryloyloxyethyl) ethyl‐dimethyl‐(3‐sulfopropyl) ammonium (MEDSA) were successfully grafted from poly(vinylidene fluoride) (PVDF) hollow fiber membrane outside surface via chemical activation and atom transfer radical polymerization (ATRP). The ATRP time at 2 h under the 2 mol/L of zwitterionic monomers was the minimum period for the complete coverage of grafted sulfobetaine polymers on the PVDF membrane surface. The surface hydrophilicity of the sulfobetaine‐modified PVDF membranes was significantly enhanced. The poly‐MPDSAH‐g‐PVDF (GA: 247 μg/cm2) and poly‐MEDSA‐g‐PVDF membranes (GA: 338 μg/cm2) efficiently resisted to the adsorption of both negative and positive charged proteins, and showed excellent anti‐protein‐fouling performance with flux recovery ratio (RFR) higher than 90% and total fouling (RT) less than 25% during the cyclic filtration of bovine serum albumin solution. After cleaned in membrane cleaning solution for 12 days, the grafted MPDSAH layer on PVDF membrane could maintain without change, however, the poly‐MEDSA‐g‐PVDF membrane lost the grafted MEDSA layer. Therefore, the amide group of sulfobetaine, which made a great contribution to the higher hydrophilicity and stability, was significant in modifying the PVDF membrane for a stably anti‐protein‐fouling performance. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
EFFECT OF Moringa oleifera FLOWER EXTRACT ON LARVAL TRYPSIN AND ACETHYLCHOLINESTERASE ACTIVITIES IN Aedes aegypti
Authors: Pontual Emmanuel Viana , Napoleão Thiago Henrique , Dias de Assis Caio Rodrigo , de Souza Bezerra Ranilson , Xavier Haroudo Satiro , Navarro Daniela Maria do Amaral Ferraz , Coelho Luana Cassandra Breitenbach Barroso , Paiva Patrícia Maria Guedes
Published: March 2012

Aedes aegypti control is crucial to reducing dengue fever. Aedes aegypti larvae have developed resistance to organophosporous insecticides and the use of natural larvicides may help manage larval resistance by increasing elements in insecticide rotation programs. Here, we report on larvicidal activity of Moringa oleifera flower extract against A. aegypti L1, L2, L3, and L4 as well as the effect of flower extract on gut trypsin and whole‐larval acetylcholinesterase from L4. In addition, the heated flower extract was investigated for larvicidal activity against L4 and effect on larval gut trypsin. Moringa oleifera flower extract contains a proteinaceous trypsin inhibitor (M. oleifera flower trypsin inhibitor, MoFTI), triterpene (β‐amyrin), sterol (β‐sitosterol) as well as flavonoids (kaempferol and quercetin). Larvicidal activity was detected against L2, L3, and L4 (LC50 of 1.72%, 1.67%, and 0.92%, respectively). Flower extract inhibited L4 gut trypsin (MoFTI Ki = 0.6 nM) and did not affect acetylcholinesterase activity. In vivo assay showed that gut trypsin activity from L4 treated with M. oleifera flower extract decreased over time (0–1,440 min) and was strongly inhibited (98.6%) after 310 min incubation; acetylcholinesterase activity was not affected. Thermal treatment resulted in a loss of trypsin inhibitor and larvicidal activities, supporting the hypothesis that flower extract contains a proteinaceous trypsin inhibitor that may be responsible for the deleterious effects on larval mortality.
SHG nanoprobes: Advancing harmonic imaging in biology
Authors: Dempsey William P. , Fraser Scott E. , Pantazis Periklis
Published: March 2012

Second harmonic generating (SHG) nanoprobes have recently emerged as versatile and durable labels suitable for in vivo imaging, circumventing many of the inherent drawbacks encountered with classical fluorescent probes. Since their nanocrystalline structure lacks a central point of symmetry, they are capable of generating second harmonic signal under intense illumination – converting two photons into one photon of half the incident wavelength – and can be detected by conventional two‐photon microscopy. Because the optical signal of SHG nanoprobes is based on scattering, rather than absorption as in the case of fluorescent probes, they neither bleach nor blink, and the signal does not saturate with increasing illumination intensity. When SHG nanoprobes are used to image live tissue, the SHG signal can be detected with little background signal, and they are physiologically inert, showing excellent long‐term photostability. Because of their photophysical properties, SHG nanoprobes provide unique advantages for molecular imaging of living cells and tissues with unmatched sensitivity and temporal resolution.
Slicing embryos gently with laser light sheets
Authors: Huisken Jan
Published: March 2012

Light sheet microscopy is an easy to implement and extremely powerful alternative to established fluorescence imaging techniques such as laser scanning confocal, multi‐photon and spinning disk microscopy. By illuminating the sample only with a thin slice of light, photo‐bleaching is reduced to a minimum, making light sheet microscopy ideal for non‐destructive imaging of fragile samples over extended periods of time. Millimeter‐sized samples can be imaged rapidly with high resolution and high depth penetration. A large variety of instruments have been developed and optimized for a number of different samples: Bessel beams form thin light sheets for single cells, and selective plane illumination microscopy (SPIM) offers multi‐view acquisition to image entire embryos with isotropic resolution. This review explains how light sheet microscopy involves a conceptually new microscope design and how it changes modern imaging in biology.
Determination of Chinese hamster ovary cell line stability and recombinant antibody expression during long‐term culture
Authors: Bailey Laura A , Hatton Diane , Field Ray , Dickson Alan J
Published: March 2012

Chinese hamster ovary (CHO) cell lines are frequently used as hosts for the production of recombinant therapeutics, such as monoclonal antibodies, due to their ability to perform correct post‐translational modifications. A potential issue when utilizing CHO cells for therapeutic protein production is the selection of cell lines that do not retain stable protein expression during long‐term culture (LTC). Instability of expression impairs process yields, effective usage of time and money, and regulatory approval for the desired therapeutic. In this study, we investigated a model unstable GS‐CHO cell line over a continuous period of approximately 100 generations to determine markers of mechanisms that underlie instability. In this cell line, stability of expression was retained for 40–50 generations after which time a 40% loss in antibody production was detected. The instability observed within the cell line was not due to a loss in recombinant gene copy number or decreased expression of mRNA encoding for recombinant antibody H or L chain, but was associated with lower cumulative cell time values and an apparent increased sensitivity to cellular stress (exemplified by increased mRNA expression of the stress‐inducible gene GADD153). Changes were also noted in cellular metabolism during LTC (alterations to extracellular alanine accumulation, and enhanced rates of glucose and lactate utilization, during the exponential and decline phase of batch culture, respectively). Our data indicates the breadth of changes that may occur to recombinant CHO cells during LTC ranging from instability of recombinant target production at a post‐mRNA level to metabolic events. Definition of the mechanisms, regulatory events, and linkages underpinning cellular phenotype changes require further detailed analysis at a molecular level. Biotechnol. Bioeng. 2012; 109:2093–2103. © 2012 Wiley Periodicals, Inc.
Tailor‐Made Mesoporous Ti‐SBA‐15 Catalysts for Oxidative Desulfurization of Refractory Aromatic Sulfur Compounds in Transport Fuel
Authors: Kim Tae‐Wan , Kim Min‐Ji , Kleitz Freddy , Nair Mahesh Muraleedharan , Guillet‐Nicolas Rémy , Jeong Kwang‐Eun , Chae Ho‐Jeong , Kim Chul‐Ung , Jeong Soon‐Yong
Published: March 2012

We propose large‐pore titanium‐containing organosilylated mesoporous silica (Ti‐SBA‐15) as a highly efficient catalyst for the oxidative desulfurization (ODS) of refractory aromatic sulfur compounds with the aim to produce ultra‐low sulfur diesel. To achieve this, we synthesized a series of mesoporous Ti‐SBA‐15 catalysts according to a new procedure. The procedure is based on the controlled grafting of titanium chelates on SBA‐15 silica at low temperatures (5 °C). This specific synthesis procedure ensured a high dispersion of the required 4‐coordinate tetrahedral Ti4+ sites located on the mesopore surface. To substantiate the influence of the titanium content and mesopore size on the ODS performance of the catalysts, the parameters were varied in the range of 0.7 to 4.7 mol % (Si/Ti) and 5.1 to 9.0 nm, respectively. The resulting Ti‐SBA‐15 catalysts were then tested in the oxidative desulfurization (ODS) of model sulfur‐containing compounds in the presence of cumene hydroperoxide (CHP) as the organic oxidant. The ODS of a real industrial diesel fuel was also carried out in a continuous fixed bed reactor with the same Ti‐SBA‐15 catalysts and CHP. The catalytic results revealed that the Ti‐SBA‐15 catalysts with the largest pore sizes (>7.3 nm) and highest Ti contents (>2.8 mol %) were highly active catalysts for ODS reactions. Moreover, the catalysts with large pores and high Ti loadings appeared to be stable for over 30 h and were far less prone to deactivation than their equivalent Ti‐SBA‐15 samples with smaller pore diameters and lower Ti contents.
Supercritical CO2 Extraction Optimization of Onion Oil Using Response Surface Methodology
Authors: Ye C.‐L. , Lai Y.‐F.
Published: March 2012

Response surface methodology was employed to optimize the conditions of supercritical CO2 extraction of the oil from freeze‐dried onion powder. The effects of pressure, temperature and extraction time on the yield of oil were investigated. The maximum extraction yield of 4.69 ± 0.04 g/kg dry basis was achieved at a pressure of 20.6 MPa, a temperature of 40.6 °C, a time of 260 min, a CO2 flow rate of 22 L h–1, and an entrainer ratio of 0.1 mL absolute ethanol per gram dry basis. The chemical composition of the oil was analyzed by gas chromatography‐mass spectrometry. The most representative compounds of the essential oil were organosulfur‐containing compounds and, among these, the main constituents were methyl 5‐methylfuryl sulfide (18.30 %), methyl 3,4‐dimethyl‐2‐thienyl disulfide (11.75 %) and 1‐propenyl propyl disulfide (9.72 %).
General rules for optimal tuning the PIλDµ controllers with application to first‐order plus time delay processes
Authors: Merrikh‐Bayat Farshad
Published: March 2012

For two main reasons optimal tuning the PIλDµ controllers is a challenging task: First, the search space is very large in dealing with such controllers, and second, there is not any generally applicable method for stability testing of the linear feedback systems containing both time delay and fractional‐order controllers. Hence, easy‐to‐use and effective rules for optimal tuning such controllers are highly demanded. In this paper, explicit formulas for optimal tuning the parameters of the PIλDµ controller, when it is applied in series with a first‐order plus time‐delay process in a standard output‐feedback system, are proposed. © 2012 Canadian Society for Chemical Engineering
An engineering analysis of transient laminar flows in long microchannels
Authors: Eskin Dmitry
Published: March 2012

An engineering model of a transient laminar flow from a pressurised vessel through a long microchannel under a condition of a rapid valve opening at a channel outlet is developed. A valve at the channel outlet, which is opening with a given speed, is modelled as a time‐dependent boundary condition. Transient flows are investigated numerically by the method of characteristics. The calculations show that variations of pressure and velocity distributions along the channel over time, caused by a transient flow regime, decrease with a decrease in the channel diameter and the channel length, an increase in the time of valve opening and an increase in the fluid viscosity. © 2012 Canadian Society for Chemical Engineering
Neighborhood‐level socioeconomic determinants impact outcomes in nonsmall cell lung cancer patients in the Southeastern United States
Authors: Erhunmwunsee Loretta , Joshi Mary‐Beth M. , Conlon Debbi H. , Harpole David H.
Published: March 2012

BACKGROUND:

Studies examining the impact of lower socioeconomic status (SES) on the outcomes of patients with nonsmall cell lung cancer (NSCLC) are inconsistent. The objective of this study was to clearly elucidate the association between SES, education, and clinical outcomes among patients with NSCLC.

METHODS:

The study population was derived from a consecutive, retrospective cohort of patients with NSCLC who received treatment within the Duke Health System between 1995 and 2007. SES determinants were based on the individual's census tract and corresponding 2000 Census data. Determinants included the percentage of the population living below poverty, the median household income, and the percentages of residents with at least a high school diploma and at least a bachelor's degree. The SES and educational variables were divided into quartiles. Statistical comparisons were performed using the 25th and 75th percentiles.

RESULTS:

Individuals who resided in areas with a low median household income or in which a high percentage of residents were living below the poverty line had a shorter cancer‐specific 6‐year survival than individuals who resided in converse areas (P = .0167 and P = .0067, respectively). Those living in areas in which a higher percentage of residents achieved a high school diploma had improved disease outcomes compared with those living in areas in which a lower percentage attained a high school diploma (P = .0033). A survival advantage also was observed for inhabitants of areas in which a higher percentage of residents attained a bachelor's degree (P = .0455).

CONCLUSIONS:

Low SES was identified as an independent prognostic factor for poor survival in patients with both early and advanced stage NSCLC. Patients who lived in areas with high poverty levels, low median incomes, and low education levels had worse mortality. Cancer 2012. © 2012 American Cancer Society.
Favorable prognosis in patients with T1a/T1bN0 triple‐negative breast cancers treated with multimodality therapy
Authors: Ho Alice Y. , Gupta Gaorav , King Tari A. , Perez Carmen A. , Patil Sujata M. , Rogers Katherine H. , Wen Yong Hannah , Brogi Edi , Morrow Monica , Hudis Clifford A. , Traina Tiffany , McCormick Beryl , Powell Simon N. , Robson Mark E.
Published: March 2012

BACKGROUND:

The authors evaluated the clinical characteristics, natural history, and outcomes of patients who had ≤1 cm, lymph node‐negative, triple‐negative breast cancer (TNBC).

METHODS:

After excluding patients who had received neoadjuvant therapy, 1022 patients with TNBC who underwent definitive breast surgery during 1999 to 2006 were identified from an institutional database. In total, 194 who had lymph node‐negative tumors that measured ≤1 cm comprised the study population. Clinical data were abstracted, and survival outcomes were analyzed.

RESULTS:

The median follow‐up was 73 months (range, 5‐143 months). The median age at diagnosis was 55.5 years (range, 27‐84 years). Tumor (T) classification was microscopic (T1mic) in 16 patients (8.2%), T1a in 49 patients (25.3%), and T1b in 129 patients (66.5%). Most tumors were poorly differentiated (n = 142; 73%), lacked lymphovascular invasion (n = 170; 87.6%), and were detected by screening (n = 134; 69%). In total, 129 patients (66.5%) underwent breast‐conserving surgery, and 65 patients (33.5%) underwent mastectomy. One hundred thirteen patients (58%) received adjuvant chemotherapy, and 123 patients (63%) received whole‐breast radiation. The patients who received chemotherapy had more adverse clinical and disease features (younger age, T1b tumor, poor tumor grade; all P < .05). Results from testing for the breast cancer (BRCA) susceptibility gene were available for 49 women: 19 women had BRCA1 mutations, 7 women had BRCA2 mutations, and 23 women had no mutations. For the entire group, the 5‐year local recurrence‐free survival rate was 95%, and the 5‐year distant metastasis‐free survival rate was 95%. There was no difference between patients with T1mic/T1a tumors and patients with T1b tumors in the distant recurrence rate (94.5% vs 95.5%, respectively; P = .81) or in the receipt of chemotherapy (95.9% vs 94.5%, respectively; P = .63).

CONCLUSIONS:

Excellent 5‐year locoregional and distant control rates were achievable in patients with TNBC who had tumors ≤1.0 cm, 58% of whom received chemotherapy. These results identified a group of patients with TNBC who had favorable outcomes after early detection and multimodality treatment. Cancer 2012. © 2012 American Cancer Society.
Favorable survival maintained in children who have myeloid leukemia associated with Down syndrome using reduced‐dose chemotherapy on Children's Oncology Group trial A2971
Authors: Sorrell April D. , Alonzo Todd A. , Hilden Joanne M. , Gerbing Robert B. , Loew Thomas W. , Hathaway Lois , Barnard Dorothy , Taub Jeffrey W. , Ravindranath Yaddanapudi , Smith Franklin O. , Arceci Robert J. , Woods William G. , Gamis Alan S.
Published: March 2012

BACKGROUND:

Children who are treated for myeloid leukemia associated with Down syndrome (DS) experience superior survival compared with children who have myeloid leukemia without DS. To maintain excellent outcomes while avoiding toxicity, the Children's Oncology Group (COG) conducted the phase 3 trial COG A2971, the first trial solely designed to provide uniform treatment of myeloid leukemia in North American children with DS. A2971 eliminated 2 induction drugs and 3 months of maintenance therapy from the standard‐timing regimen of dexamethasone, cytarabine, 6‐thioguanine, etoposide, and rubidomycin/daunomycin (DCTER) used in the previous study (Children's Cancer Group [CCG] 2891).

METHODS:

COG A2971 was a multi‐institutional, nonrandomized, clinical trial that enrolled 132 patients who had DS with either acute myeloid leukemia (n = 91) or myelodysplastic syndrome (n = 41).

RESULTS:

The median follow‐up was 4.8 years (range, 0.8‐8.6 years), the median age at diagnosis was 1.7 years (range, 0.3‐13.6 years), and the median white blood cell count was 6200/μL (range, 900‐164,900/μL). The remission rate (92.7% ± 6%) was similar to that reported in the CCG 2891 study (91.3% ± 5%; P = .679). The 5‐year event free survival (EFS) rate was 79% ± 7% (vs 77% ± 7% in CCG 2891; P = .589), the disease‐free survival (DFS) rate was 89% ± 6% (vs 85% ± 6% in CCG 2891; P = .337), and the overall survival rate was 84% ± 6% (vs 79% ± 7% in CCG 2891; P = .302). Induction day‐14 bone marrow response trended toward a more favorable outcome (EFS: P = .12). Age >4 years was an adverse risk factor (5‐year EFS rate: 33% ± 38% for children aged >4 years [median, 8.5 years; n = 6] vs 81% ± 7% for children ages 0‐4 years [median, 1.7 years; n = 126]; P = .001).

CONCLUSIONS:

The COG A2971 trial reduced the chemotherapy dose and maintained survival to that achieved by the CCG 2891 trial in children who had myeloid leukemia associated with DS. Cancer 2012. © 2012 American Cancer Society.
Flat‐top illumination profile in an epifluorescence microscope by dual microlens arrays
Authors: Coumans Frank A. W. , van der Pol Edwin , Terstappen Leon W. M. M.
Published: March 2012

Low uniformity in illumination across the image plane impairs the ability of a traditional epifluorescence microscope to quantify fluorescence intensities. Two microlens arrays (MLAs) were introduced into the illumination path of two different epifluorescence microscope systems to improve the uniformity of the illumination. Measurements of the uniformity of illumination were performed with a CCD camera in the focal plane and with fluorescent beads in the image plane. In semi critical alignment, a uniformity of illumination of 15–23% was found compared with 1–2% in the modified system. Coefficient of variation (CV) of fluorescent beads measured on the unmodified system was 20.4% ± 5.3% in semi critical alignment and 10.8% ± 1.3% in Koehler alignment. On the MLA systems, CV was 7.9% ± 2.0% and on a flow cytometer, the CV was 6.7% ± 0.7%. Implementation of MLAs in an epifluorescence microscope improves the uniformity of illumination, thereby reducing the variation in detection of fluorescent signals of the measured objects and becomes equivalent to that of flow cytometry. © 2012 International Society for Advancement of Cytometry
Lanthanide Complexes Formed with the Tri‐ and Tetraacetate Derivatives of Bis(aminomethyl)phosphinic Acid: Equilibrium, Kinetic and NMR Spectroscopic Studies
Authors: Tircsó Gyula , Kálmán Ferenc K. , Pál Róbert , Bányai István , Varga Tamás R. , Király Róbert , Lázár István , Québatte Laurent , Merbach André E. , Tóth Éva , Brücher Ernő
Published: March 2012

The lanthanide(III) complexes formed with the tri‐ and tetraacetate derivatives of bis(aminomethyl)phosphinic acid, L1 and L2, respectively, have been studied by pH potentiometry, spectrophotometry and 1H and 17O NMR spectroscopy. L1 forms [Ln(L1)]–, [Ln(L1)2]4–, protonated [Ln(HL1)] and Ln(H2L1)]+, and [Ln(L1)(OH)]2– hydroxido complexes. Heptadentate L2 forms [Ln(L2)]2– and protonated [Ln(HL2)]– and [Ln(H2L2)] complexes in solution and it shows a strong propensity to form [Ln2(L2)]+ dinuclear complexes, which has not been observed previously. The stability constants (log KLnL) of the complexes increase in the order [Ln(L1)]– < [Ln(L2)]2– following the order of increasing number of acetate pendants attached to the bis(aminomethyl)phosphinic acid (BAP) backbone. Within the LnIII series, the log KLnL values increase from La3+ to Gd3+ and remain practically constant for the heavier lanthanides. Despite the lower basicity, the ligands that contain a phosphinate group generally form similar (L1) or more stable (L2) Ln3+ complexes than the structurally similar N‐benzylethylenediamine‐N,N′,N′‐triacetic acid (L3) and propylenediamine‐N,N,N′,N′‐tetraacetic acid (L4), respectively. This indicates that the hard phosphinate group may be coordinated to the Ln3+ ions in the complexes, whereas the larger negative charge of the BAP derivatives may also have an extra stabilizing effect. The kinetic inertness of [Ln(L1)] and [Ln(L2)] is lower than that of similar [Ln(EDTA)]– (EDTA = ethylenediamine‐N,N,N′,N′‐tetraacetic acid), but the rate constants that characterize the dissociation of [Ln(L2)]2– are at least two orders of magnitude lower than those obtained for [Ln(L4)]–. Variable‐temperature 17O transverse and longitudinal relaxation rates and NMR spectroscopic chemical shifts have been measured to assess the water exchange and rotational dynamics of [Gd(L2)]. The chemical shifts evidenced monohydration of the complex. The water exchange rate, kex298 = (2.7 ± 0.4) × 107 s–1 is about ten times higher than that of [Ln(DTPA)]2– (DTPA = diethylenetriamine‐N,N,N′,N″,N″‐pentaacetic acid). The rotational correlation time, τRO298 = 270 ± 30 ps, is long considering the small size of the chelate, which points to aggregation in aqueous solution, in accordance with the high value of the proton relaxivity measured.
Crosstalk between oligodendrocytes and cerebral endothelium contributes to vascular remodeling after white matter injury
Authors: Pham Loc‐Duyen D. , Hayakawa Kazuhide , Seo Ji Hae , Nguyen Minh‐Nguyet , Som Angel T. , Lee Brian J. , Guo Shuzhen , Kim Kyu‐Won , Lo Eng H. , Arai Ken
Published: March 2012

After stroke and brain injury, cortical gray matter recovery involves mechanisms of neurovascular matrix remodeling. In white matter, however, the mechanisms of recovery remain unclear. In this study, we demonstrate that oligodendrocytes secrete matrix metalloproteinase‐9 (MMP‐9), which accelerates the angiogenic response after white matter injury. In primary oligodendrocyte cultures, treatment with the proinflammatory cytokine interleukin‐1β (IL‐1β) induced an upregulation and secretion of MMP‐9. Conditioned media from IL‐1β‐stimulated oligodendrocytes significantly amplified matrigel tube formation in brain endothelial cells, indicating that MMP‐9 from oligodendrocytes can promote angiogenesis in vitro. Next, we asked whether similar signals and substrates operate after white matter injury in vivo. Focal white matter injury and demyelination was induced in mice via stereotactic injection of lysophosphatidylcholine into corpus callosum. Western blot analysis showed that IL‐1β expression was increased in damaged white matter. Immunostaining demonstrated MMP‐9 signals in myelin‐associated oligodendrocytic basic protein‐positive oligodendrocytes. Treatment with an IL‐1β‐neutralizing antibody suppressed the MMP‐9 response in oligodendrocytes. Finally, we confirmed that the broad spectrum MMP inhibitor GM6001 inhibited angiogenesis around the injury area in this white matter injury model. In gray matter, a neurovascular niche promotes cortical recovery after brain injury. Our study suggests that an analogous oligovascular niche may mediate recovery in white matter. © 2012 Wiley Periodicals, Inc.
Modelling spatial and temporal variability of hydrologic impacts of climate change in the Fraser River basin, British Columbia, Canada
Authors: Shrestha Rajesh R. , Schnorbus Markus A. , Werner Arelia T. , Berland Anne J.
Published: March 2012

This paper presents a modelling study on the spatial and temporal variability of climate‐induced hydrologic changes in the Fraser River basin, British Columbia, Canada. This large basin presents a unique modelling case due to its physiographic heterogeneity and the potentially large implications of changes to its hydrologic regime. The macro‐scale Variable Infiltration Capacity (VIC) hydrologic model was employed to simulate 30‐year baseline (1970s) and future (2050s) hydrologic regimes based on climate forcings derived from eight global climate models (GCMs) runs under three emissions scenarios (B1, A1B and A2). Bias Corrected Spatial Disaggregation was used to statistically downscale GCM outputs to the resolution of the VIC model (1/16°). The modelled future scenarios for the 11 sub‐basins and three regions (eastern mountains, central plateau and coastal mountains) of the FRB exhibit spatially varied responses, such as, shifts from snow‐dominant to hybrid regime in the eastern and coastal mountains and hybrid to rain‐dominant regime in the central plateau region. The analysis of temporal changes illustrated considerable uncertainties in the projections obtained from an ensemble of GCMs and emission scenarios. However, direction of changes obtained from the GCM ensembles and emissions scenarios are consistent amongst one another. The most significant temporal changes could include earlier onsets of snowmelt‐driven peak discharge, increased winter and spring runoff and decreased summer runoff. The projected winter runoff increases and summer decreases are more pronounced in the central plateau region. The results also revealed increases in the total annual discharge and decreases in the 30‐year mean of the peak annual discharge. Such climate‐induced changes could have implications for water resources management in the region. The spatially and temporally varied hydro‐climatic projections and their range of projections can be used for local‐scale adaptation in this important water resource system for British Columbia. Copyright © 2012 John Wiley & Sons, Ltd.
Seasonal controls on stream chemical export across diverse coastal watersheds in the USA
Authors: Barco Janet , Gunawan Stephanie , Hogue Terri S.
Published: March 2012

The current study focuses on understanding key factors controlling geochemical export in eight diverse coastal watersheds at seasonal and annual time scales. Geochemical, atmospheric and hydrologic data across a range of hydro‐climatic regimes and varying land uses were investigated and relationships analysed. A hyperbolic dilution model was fitted for each watershed system to evaluate discharge–concentration relationships. Nitrate concentration effects were observed in watersheds exposed to high atmospheric deposition rates as well as agricultural watersheds, whereas urban watersheds showed nitrate dilution effects. Dilution patterns were observed for calcium, magnesium and sulfate for almost all watersheds. Seasonal loads for almost all constituents were noted to be mainly driven by hydrologic seasonality, but are also dependent on inputs (atmospheric deposition and land use sources). Understanding the primary controls on hydro‐chemical interactions is critical for developing and refining predictive water quality models, especially in coastal watersheds where sensitive downstream ecosystems act as receiving waters for upstream pollutant loads. Copyright © 2012 John Wiley & Sons, Ltd.
Olive oil intake and breast cancer risk in the Mediterranean countries of the European Prospective Investigation into Cancer and Nutrition study
Authors: Buckland Genevieve , Travier Noemie , Agudo Antonio , Fonseca‐Nunes Ana , Navarro Carmen , Lagiou Pagona , Demetriou Christiana , Amiano Pilar , Dorronsoro Miren , Chirlaque María‐Dolores , Huerta José‐María , Molina Esther , Pérez Maria‐José Sánchez , Ardanaz Eva , Moreno‐Iribas Conchi , Quirós J. Ramón , Naska Androniki , Trichopoulos Dimitrios , Giurdanella Maria Concetta , Tumino Rosario , Agnoli Claudia , Grioni Sara , Panico Salvatore , Mattiello Amalia , Masala Giovanna , Sacerdote Carlotta , Polidoro Silvia , Palli Domenico , Trichopoulou Antonia , González Carlos A.
Published: March 2012

Although there is some evidence suggesting that olive oil could reduce breast cancer (BC) risk, the epidemiological data are still relatively limited, not entirely consistent and mainly based on case–control studies. Therefore, we prospectively assessed the association between olive oil and BC risk in postmenopausal women from the Mediterranean cohorts within the European Prospective Investigation into Cancer and Nutrition. The analysis included 62,284 postmenopausal women recruited from Spain, Italy and Greece who had complete dietary data (collected from validated country‐specific dietary questionnaires). The risk of BC (overall and by hormone receptor subtypes) was assessed using hazards ratios (HRs) obtained from Cox proportional hazards regression, while adjusting for known BC risk factors. After a mean follow‐up of 9 years, 1,256 women were diagnosed with a primary incident invasive BC. The multivariate HRs for BC risk by olive oil intake (highest vs. lowest tertile of g/day/2,000 kcal) were 1.07 (95% CI = 0.91–1.25) in the adjusted model, 1.06 (95% CI = 0.91–1.24) in the model additionally adjusted for reproductive‐related factors and 1.10 (95% CI = 0.92–1.31) for the model additionally adjusted for dietary factors. There was no association between olive oil and risk of estrogen or progesterone receptor‐positive tumors, but a suggestion of a negative association with estrogens and progesterone receptor‐negative tumors. The results from our prospective study showed that olive oil consumption during adult life was not associated with the risk of BC. However, larger prospective studies are still needed to explore possible differences related to hormone receptor status.
Islamophobia in Classrooms, Media, and Politics
Authors: Zaal Mayida
Published: March 2012

Social and political tensions heightened after the attacks of 9/11 have created an increase in Islamophobia. Historically, vilified depictions of Muslims have legitimized discriminatory acts against Muslim Americans. In this context, Islamophobia has infiltrated our classrooms, making it urgent for educators to develop a critical pedagogical stance that counters discrimination and demystifies stereotypes against Muslim American students.
Small zebrafish in a big chemical pond
Authors: Helenius I. Taneli , Joanna Yeh J.‐R.
Published: March 2012

The number of possible small organic molecules of different structure is virtually limitless. One of the main goals of chemical biologists is to identify, from this “chemical space”, entities that affect biological processes or systems in a specific manner. This can lead to a better understanding of the regulation and components of various biological machineries, as well as provide insights into efficacious therapeutic targets and drug candidates. However, the challenges confronting chemical biologists are multiple. How do we efficiently identify compounds that possess desirable activities without unwanted off‐target effects? Once a candidate compound has been found, how do we determine its mode of action? In this Prospects piece, we call attention to recent studies using embryonic and larval zebrafish to illustrate the breadth and depth of questions in chemical biology that may be addressed using this model, and hope that they can serve as catalysts for future investigational ideas. J. Cell. Biochem. 113: 2208–2216, 2012. © 2012 Wiley Periodicals, Inc.
Comparative genomic structures of Mycobacterium CRISPR‐Cas
Authors: He Liming , Fan Xiangyu , Xie Jianping
Published: March 2012

Clustered regularly interspaced short palindromic repeats (CRISPR) are inheritable genetic elements of many archaea and bacteria, conferring acquired immunity against invading nucleic acids. CRISPR might be indicative of the bacterial niche adaptation and evolutionary. Mycobacterium is an important genus occupying diverse niches with profound medical and environmental significance. To present a comparative genomic landscape of the Mycobacterium CRISPR, the feature of mycobacterium CRISPR structures with sequenced complete genomes were bioinformatically analyzed. The results show that CRISPR structures can be found among 14 mycobacteria, and all loci are chromosomally located. Long CRISPRs present in three species, namely M. tuberculosis, M. bovis, and M. avium. Integrated CRISPR‐Cas system can only be found in M. tuberculosis and M. bovis, with highly conserved repeat sequences, very short leaders, and promoterless. M. tuberculosis and M. bovis repeat sequences cannot form stable RNA secondary structure, consistent with a Cas6‐binding sequence. M. avium repeat sequences can form classical stem‐loop structure. A three‐step model of M. tuberculosis CRISPR‐Cas system action was put forward based on the composition and function of cas genes cluster. M. tuberculosis and M. bovis CRISPRs might interfere with the invading nucleic acids, but have somehow lost the capacity to incorporate new spacers and co‐evolve with corresponding mycobacteriophages. J. Cell. Biochem. 113: 2464–2473, 2012. © 2012 Wiley Periodicals, Inc.
Preparation of Sb2O3‐loaded Activated Carbon Particle Electrode and Its Electrocatalytic Degradation of Methyl Orange in a Three‐dimensional Electrode Cell
Authors: Cao Guiping , Su Jian , Lu Jilai , Zhang Jintao , Liu Qingjian
Published: March 2012

Electrocatalysis on the degradation of methyl orange is investigated using Sb2O3‐loaded activated carbon (Sb2O3/AC), a new particle electrode. The electrode was prepared by an impregnation method. An orthogonal array with four factors and three levels was selected to carry out the experiment. Electrocatalysis on the degradation of methyl orange through Sb2O3/AC was characterized by a series of parameters, including the amount of the particle electrode, the concentration of Na2SO4, the cell voltage, and the electrolysis time, and the results were compared with those of a conventional AC particle electrode. The results indicate that calcination temperature has the greatest impact on the catalytic activity of the particle electrode. The optimal conditions for preparing the Sb2O3/AC electrode include an 8 mL SbCl3 solution, 90 min hydrolysis time, 400 °C calcination temperature, and 180 min calcination time. As well, the degradation efficiency of the Sb2O3/AC electrode is consistently higher than that of the AC electrode under the same electrolysis conditions. The electrochemical oxidation of methyl orange of both electrodes conformed to pseudo first‐order kinetics, but the rate constant of the Sb2O3/AC electrode was 2.29 times that of the AC electrode; this is likely due to the high electrocatalytic activity of the experimental electrode. The electrocatalysis results exhibited the synergetic effects of AC and Sb2O3 in the new particle electrode.
Recent Research Progress of Red Phosphors for PDPs Applications
Authors: Wang Yuhua , Zhang Feng , Liu Bitao , Wen Yan
Published: March 2012

The commercial vacuum ultraviolet (VUV) red phosphor (Y, Gd)BO3:Eu3+ has low luminous efficiency and poor color purity. Our work aims to overcome this drawback and we mainly devote to investigating the luminescence mechanism, improving the commercial red phosphor, and seeking for new red emitting VUV materials with high efficiency. Based on the investigation of the photoluminescence mechanism of VUV phosphors, both the luminous efficiency and the color purity of (Y, Gd)BO3:Eu3+ are improved. Additionally, a series of novel VUV red phosphors have been developed, such as (Gd,Y)Al3(BO3)4:Eu3+ and (La,Gd)P3O9:Eu3+. This presentation is a review about the recent research progress of red phosphors for plasma displays (PDPs) applications in our group.
Computer‐controlled, MR‐compatible foot‐pedal device to study dynamics of the muscle tendon complex under isometric, concentric, and eccentric contractions
Authors: Sinha Shantanu , Shin David D. , Hodgson John A. , Kinugasa Ryuta , Edgerton V. Reggie
Published: March 2012

Purpose:

To design a computer‐controlled, magnetic resonance (MR)‐compatible foot pedal device that allows in vivo mapping of changes in morphology and in strain of different musculoskeletal components of the lower leg under passive, isometric, concentric, and eccentric contractions.

Materials and Methods:

A programmable servomotor in the control room pumped hydraulic fluid to rotate a foot‐pedal inside the magnet. To validate the performance of the device, six subjects were imaged with gated velocity‐encoded phase‐contrast (VE‐PC) imaging to investigate the dynamics of muscle and aponeurotic structures.

Results:

Artifact‐free VE‐PC imaging clearly delineated different muscle compartments by differences in distribution of mechanical strains. High repeatability of contraction cycles allowed establishing that fascicles lengthened 6.1% more during passive compared with eccentric contractions. Aponeurosis separation during passive (range between three locations: −2.6≈1.3 mm) and active (range: −2.4≈1.6 mm) contractions were similar but significantly different from concentric (range: −0.9≈3.3 mm), with proximal and distal regions showing mostly negative values for the first two modes, but positive for the last.

Conclusion:

The device was sufficiently robust and artifact‐free to accurately assess, using VE‐PC imaging, physiologically important structure and dynamics of the musculotendon complex. J. Magn. Reson. Imaging 2012;36:405–410. © 2012 Wiley Periodicals, Inc.
In vivo assessment of age‐related brain iron differences by magnetic field correlation imaging
Authors: Adisetiyo Vitria , Jensen Jens H. , Ramani Anita , Tabesh Ali , Di Martino Adriana , Fieremans Els , Castellanos Francisco X. , Helpern Joseph A.
Published: March 2012

Purpose:

To assess a recently developed magnetic resonance imaging (MRI) technique called magnetic field correlation (MFC) imaging along with a conventional imaging method, the transverse relaxation rate (R2), for estimating age‐related brain iron concentration in adolescents and adults. Brain region measures were compared with nonheme iron concentrations (CPM) based on a prior postmortem study.

Materials and Methods:

Asymmetric spin echo (ASE) images were acquired at 3T from 26 healthy individuals (16 adolescents, 10 adults). Regions of interest (ROIs) were placed in areas in which age‐related iron content was estimated postmortem: globus pallidus (GP), putamen (PUT), caudate nucleus (CN), thalamus (THL), and frontal white matter (FWM). Regression and group analyses were conducted on ROI means.

Results:

MFC and R2 displayed significant linear relationships to CPM when all regions were combined. Whereas MFC was significantly correlated with CPM for every individual region except FWM and detected significantly lower means in adolescents than adults for each region, R2 detected significant correlation and lower means for only PUT and CN.

Conclusion:

Our results support the hypothesis that MFC is sensitive to brain iron in GM regions and detects age‐related iron increases known to occur from adolescence to adulthood. MFC may be more sensitive than R2 to iron‐related changes occurring within specific brain regions. J. Magn. Reson. Imaging 2012;36:322–331. © 2012 Wiley Periodicals, Inc.
Recent climate change in the Arabian Peninsula: annual rainfall and temperature analysis of Saudi Arabia for 1978–2009
Authors: Almazroui Mansour , Nazrul Islam M. , Athar H. , Jones P. D. , Rahman M. Ashfaqur
Published: March 2012

The rainfall and temperature climatology over the Arabian Peninsula are analysed on an annual basis using various gridded datasets. For Saudi Arabia, the area of which represents almost 80% of the Peninsula, the climatic datasets from its 27 ground observations are analysed for the period 1978–2009, with additional gridded datasets used to describe the observed state and change of the present climate. The gridded datasets represent well the very dry (40–80 mm) area over the world's largest sand desert (Rub Al‐Khali), the dry (80–150 mm) area over middle‐to‐north of Saudi Arabia, and the wettest (>150 mm) region in the southwest of the Peninsula. The annual temperature is relatively high (24–27 °C) in the middle‐to‐south of the Peninsula and low (<21 °C) in the northwest and southwest. The highest temperature (>27 °C) is obtained over the Rub Al‐Khali. Over Saudi Arabia, the observed annual rainfall showed a significant decreasing trend (47.8 mm per decade) in the last half of the analysis period, with a relatively large interannual variability, while the maximum, mean and minimum temperatures have increased significantly at a rate of 0.71, 0.60, and 0.48 °C per decade, respectively. This information is invaluable to consider in any climate impact assessment studies in Saudi Arabia. Copyright © 2012 Royal Meteorological Society