bluuebunny/crossref_metadata_2025_split huggingface dataset:
SHG nanoprobes: Advancing harmonic imaging in biology
Authors: Dempsey William P. , Fraser Scott E. , Pantazis Periklis 
Published: March 2012

AbstractSecond 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

AbstractLight 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

AbstractChinese 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

AbstractWe 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

AbstractResponse 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

AbstractFor 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

AbstractAn 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

AbstractBACKGROUND: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

AbstractBACKGROUND: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

AbstractBACKGROUND: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

AbstractLow 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

AbstractThe 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

AbstractAfter 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.