bluuebunny/crossref_metadata_2025 huggingface dataset:
Butyrate production enhancement by Clostridium tyrobutyricum using electron mediators and a cathodic electron donor
Authors: Choi Okkyoung , Um Youngsoon , Sang Byoung‐In
Published: April 2012

Electron mediators and electron supply through a cathode were examined to enhance the reducing power for butyrate production by an acidogenic clostridium strain, Clostridium tyrobutyricum BAS 7. Among the tested electron mediators, methyl viologen (MV)‐amended cultures showed an increase of butyrate productivity (1.3 times), final concentration (1.4 times), and yield (1.3 times). The electron flow altered by MV addition from the ferredoxin pool to the NADH pool was shown by one electron model, implying that more available NADH increased butyrate production. In the cathode compartment poised at −400 mV versus the Ag/AgCl electrode, the neutral red (NR)‐amended cultures of Clostridium tyrobutyricum BAS 7 increased butyrate concentration (from 5 to 8.8 g/L) and yield (from 0.33 up to 0.44 g/g) with no acetate production at all. Given that electrically reduced NR (NRred, yellow) by the cathode was re‐oxidized (NRox, red) in the cells on the basis of color change, electron flow from NRred to NAD+ (i.e., NADH generation) induced an increase in butyrate production. This is the first report to show the increase of butyric acid production by electrically driven acidogenesis. These results show that the electron flow altered NADH formation by electron mediators and by the cathodic electron donor, increasing the yield and selectivity of reduced end‐products like butyrate. Biotechnol. Bioeng. 2012; 109: 2494–2502. © 2012 Wiley Periodicals, Inc.
Chip‐based protein–protein interaction studied by atomic force microscopy
Authors: Kao Feng‐Sheng , Ger Waylon , Pan Yun‐Ru , Yu Hui‐Chen , Hsu Ray‐Quen , Chen Hueih‐Min
Published: April 2012

In this article, a technique for accurate direct measurement of protein‐to‐protein interactions before and after the introduction of a drug candidate is developed using atomic force microscopy (AFM). The method is applied to known immunosuppressant drug candidate Echinacea purpurea derived cynarin. T‐cell/CD28 is on‐chip immobilized and B‐cell/CD80 is immobilized on an AFM tip. The difference in unbinding force between these two proteins before and after the introduction of cynarin is measured. The method is described in detail including determination of the loading rates, maximum probability of bindings, and average unbinding forces. At an AFM loading rate of 1.44 × 104 pN/s, binding events were largely reduced from 61 ± 5% to 47 ± 6% after cynarin introduction. Similarly, maximum probability of bindings reduced from 70% to 35% with a blocking effect of about 35% for a fixed contact time of 0.5 s or greater. Furthermore, average unbinding forces were reduced from 61.4 to 38.9 pN with a blocking effect of ∼37% as compared with ∼9% by SPR. AFM, which can provide accurate quantitative measures, is shown to be a good method for drug screening. The method could be applied to a wider variety of drug candidates with advances in bio‐chip technology and a more comprehensive AFM database of protein‐to‐protein interactions. Biotechnol. Bioeng. 2012; 109: 2460–2467. © 2012 Wiley Periodicals, Inc.
Novel renewable ionic liquids as highly effective solvents for pretreatment of rice straw biomass by selective removal of lignin
Authors: Hou Xue‐Dan , Smith Thomas J. , Li Ning , Zong Min‐Hua
Published: April 2012

Cholinium amino acids ionic liquids ([Ch][AA] ILs), a novel type of bio‐ILs that can easily be prepared from renewable biomaterials, were investigated for pretreatment of rice straw by selective extraction of lignin from this abundant lignocellulosic biomass material. Of the eight ILs examined, most were demonstrated to be excellent pretreatment solvents. Upon pretreatment using these ILs, the initial saccharification rates of rice straw residues were substantially improved as well as the extent to which polysaccharides could be digested (>90% for cellulose and >60% for xylan). Enzymatic hydrolysis of pretreated rice straw by Trichoderma reesei cellulase/xylanase furnished glucose and xylose with the yields in excess of 80% and 30%, respectively. Detailed spectroscopic characterization showed that the enhancement of polysaccharides degestibility derived mainly from delignification rather than changes in cellulose crystallinity. The yields of fermentable reducing sugars were significantly improved after individual optimization of pretreatment temperature and duration. With [Ch][Lys] as the solvent, the sugar yields of 84.0% for glucose and 42.1% for xylose were achieved after pretreatment at 90°C for 5 h. The IL [Ch][Lys] showed excellent reusability across five successive batches in pretreatment of rice straw. These bio‐ILs performed as well as or better than previously investigated non‐renewable ILs, and thus present a new and environmentally friendly way to pretreat lignocellulose for production of fermentable sugars and total utilization of the biomass. Biotechnol. Bioeng. 2012; 109: 2484–2493. © 2012 Wiley Periodicals, Inc.
Reproducibility and factors influencing the assessment of the SYNTAX score in the left main xience study
Authors: Garot Philippe , Tafflet Muriel , Kumar Sundar , Salvatella Neus , Darremont Olivier , Jouven Xavier , Carrié Didier , Lefèvre Thierry , Russu Varvara , Morice Marie‐Claude
Published: April 2012

Background: As assessment of SYNTAX score is made by visual estimate of coronary angiography, discrepancies between evaluations by different observers and the impact of observer experience have not yet been evaluated. Methods: Using the data of 166 patients with unprotected left main lesions treated with the second generation everolimus‐eluting stent, we sought to analyze SYNTAX score assessment provided by one junior and two independent senior observers and to assess the impact of the quality of angiographies on the reproducibility of SYNTAX score determination. Intra‐observer variability was assessed by a senior observer by analyzing 50 sets of angiograms after an interval of at least 6 weeks. Results: The weighted kappa value for the inter‐observer reproducibility of SYNTAX score classified as tertiles, according to SYNTAX trial, was 0.71 and the intra‐observer weighted kappa value was 0.79. When compared with junior's measurements, SYNTAX score assessed by senior investigators was 0.46 and 0.50. Changes in SYNTAX score classification were arbitrarily responsible for changes in weighted kappa values. Angiograms showing the higher rates of discrepancies between observers were of lower quality, when compared with random angiograms. SYNTAX score was closely correlated to 1‐year incidence of major adverse cerebro‐ and cardiovascular events for both junior and senior readers. Conclusions: SYNTAX score was slightly underestimated by junior reader, when compared with experienced operators. Inter‐ and intra‐observer reproducibility of experienced operators was very acceptable. SYNTAX score evaluation was clearly related to the quality of angiograms. SYNTAX score was correlated to 1‐year incidence of major cardiac and cerebrovascular events (MACCE) in all readers. © 2012 Wiley Periodicals, Inc.
Randomized study comparing everolimus‐ and sirolimus‐eluting stents in patients with bifurcation lesions treated by provisional side‐branch stenting
Authors: Pan Manuel , Medina Alfonso , Suárez de Lezo Jose , Romero Miguel , Segura Jose , Martín Pedro , Suárez de Lezo Javier , Hernandez Enrique , Mazuelos Francisco , Ojeda Soledad
Published: April 2012

Objectives

To compare the efficacy of sirolimus‐ and everolimus‐eluting stents in patients with bifurcation lesions treated with provisional side‐branch stenting.

Background

The efficacy of everolimus‐eluting stents in bifurcation lesions has been poorly tested.

Methods

Patients with all types of Medina bifurcation lesions were randomly assigned to treatment with either a sirolimus‐ (n = 145) or everolimus‐eluting stent (n = 148). We included patients with main vessel diameter over 2.5 mm and side branches over 2.25 mm. Patients with diffuse side‐branch stenosis were excluded.

Results

There were no significant differences between patients from the sirolimus and everolimus groups in terms of age, risk factors, clinical status, location of the bifurcation lesions or angiographic variables. Immediate results and in‐hospital outcome were also similar in both groups of patients. In‐hospital death occurred in two patients, one from each group. Target lesion revascularization was required in nine patients: four patients (2.7%) from the sirolimus group and five patients (3.4%) from the everolimus group. Late cardiac mortality occurred in two patients from the sirolimus group and in one patient from the everolimus group. Major cardiac event rates at 1 year were similar in both groups: nine patients (6.2%) in the sirolimus group and nine patients (6.1%) from the everolimus group (p: ns).

Conclusions

In patients with bifurcation lesions, no significant differences in clinical outcome at 1‐year follow‐up were observed between sirolimus‐ and everolimus‐eluting stent groups. © 2012 Wiley Periodicals, Inc.
Long‐term effects on vascular healing of bare metal stents delivered via paclitaxel‐coated balloons in the porcine model of restenosis
Authors: Cremers Bodo , Milewski Krzysztof , Clever Yvonne P. , Aboodi Michael S. , Biedermann Melanie , Thim Troels , Kelsch Bettina , Kaluza Greg L. , Scheller Bruno , Granada Juan F.
Published: April 2012

Background

Clinical trials have consistently demonstrated benefits of Paclitaxel‐coated balloons (PCB) in particular clinical situations such as in‐stent restenosis and peripheral vascular interventions. However, the long‐term vascular effects of bare metal stents (BMS) delivered via PCB (PCB+BMS) are still unknown. The aim of this study was to assess the long‐term effects of PCB+BMS on vascular healing and neointimal formation (NF).

Methods

A total of 208 stents: 56 BMS crimped on PCB, 50 BMS crimped on uncoated balloons (UCB+BMS), 52 Taxus and 50 Cypher stents were implanted in normal coronary arteries of 104 pigs using 1.2:1.0 stent‐to‐artery ratio. Follow‐up occurred at 3, 7, 28, 90, and 180 days. Vascular effects were assessed based on angiographic and histological analysis. Endothelialization was evaluated using an anti von‐Willebrand Factor stain.

Results

At 28 days, delivery of a BMS using a PCB led to a significant reduction in NF compared to the UCB+BMS and the Taxus stent (P < 0.01). Between 28 and 180 days, the progression of NF tended to be lower in the PCB+BMS compared to all DES groups. At 90 days, the PCB+BMS (2.56 ± 0.43) and the Taxus stents (2.60 ± 0.59) had a trend toward higher inflammatory scores compared to the UCB+BMS group (1.85 ± 1.13, P = 0.09). By 180 days, inflammation and NF had completely normalized between the groups. Expression of peristrut vWF was comparable among all tested groups at 28 days.

Conclusion

The long‐term pattern of vascular healing occurring following PCB+BMS deployment appears to be comparable to what has been reported with DES technologies. © 2012 Wiley Periodicals, Inc.
From Cosmic Chirality to Protein Structure: Lord Kelvin's Legacy
Authors: Barron Laurence D.
Published: April 2012

A selection of my work on chirality is sketched in two distinct parts of this lecture. Symmetry and Chirality explains how the discrete symmetries of parity P, time reversal T, and charge conjugation C may be used to characterize the properties of chiral systems. The concepts of true chirality (time‐invariant enantiomorphism) and false chirality (time‐noninvariant enantiomorphism) that emerge provide an extension of Lord Kelvin's original definition of chirality to situations where motion is an essential ingredient thereby clarifying, inter alia, the nature of physical influences able to induce absolute enantioselection. Consideration of symmetry violations reveals that strict enantiomers (exactly degenerate) are interconverted by the combined CP operation. Raman optical activity surveys work, from first observation to current applications, on a new chiroptical spectroscopy that measures vibrational optical activity via Raman scattering of circularly polarized light. Raman optical activity provides incisive information ranging from absolute configuration and complete solution structure of smaller chiral molecules and oligomers to protein and nucleic acid structure of intact viruses. Chirality 24:879–893, 2012. © 2012 Wiley Periodicals, Inc.
Phase 1/2 trial of single‐session stereotactic body radiotherapy for previously unirradiated spinal metastases
Authors: Garg Amit K. , Shiu Almon S. , Yang James , Wang Xin‐Shelley , Allen Pamela , Brown Barry W. , Grossman Patricia , Frija Erik K. , McAleer Mary Frances , Azeem Syed , Brown Paul D. , Rhines Laurence D. , Chang Eric L.
Published: April 2012

BACKGROUND:

In this phase 1/2 study, the authors tested the hypothesis that single‐fraction stereotactic body radiotherapy (SBRT) for previously unirradiated spinal metastases is a safe, feasible, and efficacious treatment approach.

METHODS:

All patients were evaluated by a multidisciplinary team. Spinal magnetic resonance imaging studies were obtained before treatment and at regular intervals to define both target volume and response to treatment. SBRT was delivered to a peripheral dose of 16 to 24 grays in a single fraction while limiting the dose to the spinal cord. Higher doses were used for renal cell histology. The National Cancer Institute Common Toxicity Criteria 2.0 and McCormick neurologic function score were used as toxicity assessment tools.

RESULTS:

In total, 61 patients who had 63 tumors of the noncervical spine were enrolled and received SBRT between 2005 and 2010 on a prospective, phase 1/2 trial at The University of Texas M. D. Anderson Cancer Center. The mean follow‐up was 20 months. The actuarial 18‐month imaging local control rate for all patients was 88%, the actuarial 18‐month overall survival rate for all patients was 64%, and the median survival for all patients was 30 months. No significant differences in outcomes were noted with respect to tumor histology or SBRT dose. Two patients experienced radiation adverse events (grade 3 or higher). The actuarial rate of 18‐month freedom from neurologic deterioration from any cause was 82%.

CONCLUSIONS:

Data from this phase 1/2 trial supported an expanded indication for SBRT as first‐line treatment of spinal metastases in selected patients. The authors concluded that additional studies that can prospectively identify predictive factors for spinal cord toxicity after SBRT are warranted to minimize the incidence of this serious yet rare complication. Cancer 2012. © 2012 American Cancer Society.
Human immunodeficiency virus‐associated plasmablastic lymphoma
Authors: Castillo Jorge J. , Furman Michael , Beltrán Brady E. , Bibas Michele , Bower Mark , Chen Weina , Díez‐Martín José L. , Liu Jane J. , Miranda Roberto N. , Montoto Silvia , Nanaji Nahid M. , Navarro José‐Tomás , Seegmiller Adam C. , Vose Julie M.
Published: April 2012

BACKGROUND:

Plasmablastic lymphoma (PBL) is a rare and aggressive B‐cell lymphoma strongly associated with human immunodeficiency virus (HIV) infection. The authors conducted a multi‐institutional, retrospective study to describe characteristics and determine prognostic factors in HIV‐associated PBL.

METHODS:

For this study, the investigators included consecutive, HIV‐positive patients diagnosed between the years 2000 and 2010 whose tumors had a plasmablastic morphology, were cluster of differentiation 20 (CD20)‐negative, and expressed markers of plasmacytic differentiation.

RESULTS:

Fifty patients from 13 institutions were evaluated. The median age was 43 years, and there was a male predominance. The median count of cells that were positive for CD4 (a glycoprotein expressed on the surface of T‐helper cells, monocytes, macrophages, and dendritic cells) was 206 cells/mm3. At presentation, 90% of patients had extranodal involvement, 69% presented with advanced stage disease, and 27% had oral involvement. Rearrangements of v‐myc myelocytomatosis viral oncogene homolog (MYC) were detected in 41% of the tested patients. Eighty‐five percent of patients received chemotherapy, with 63% receiving cyclophosphamide, doxorubicin, vincristine, and prednisone and 37% receiving more intensive regimens. The complete response (CR) rate was 66%. The median overall survival (OS) was 11 months regardless of the intensity of chemotherapy. In the survival analysis, an Eastern Cooperative Oncology Group performance status ≥2, advanced stage, and MYC rearrangements were associated significantly with a worse outcome, whereas attaining a CR with chemotherapy was associated with a better outcome.

CONCLUSIONS:

The prognosis of PBL in HIV‐infected individuals remains poor in the highly active antiretroviral therapy era. Intensive chemotherapy regimens do not seem to increase survival in patients with HIV‐associated PBL. Cancer 2012. © 2012 American Cancer Society.
Reactions of CS2 and C(S)NPh Adducts of N‐Heterocyclic Carbenes with [Ru3(CO)12]: Remarkable Reactivity of These Betaines Involving One or Two C–S Bond Activation Processes
Authors: Cabeza Javier A. , García‐Álvarez Pablo , Guadalupe Hernández‐Cruz M.
Published: April 2012

Two structurally related tetranuclear complexes, [Ru4(μ4‐κ2C,S‐IMe–CS)(μ4‐S)(μ‐CO)2(CO)9] (1) and [Ru4(μ4‐κ2C,N‐TMe–CNPh)(μ4‐S)(μ‐CO)(CO)10] (2), have been isolated from reactions of [Ru3(CO)12] with 1 equiv. of the betaines IMe–CS2 (IMe = 1,3‐dimethylimidazol‐2‐ylidene) and TMe–C(S)NPh (TMe = 3‐methylthiazol‐2‐ylidene), respectively. Both products contain μ4‐S ligands that arise from the unprecedented cleavage of the thiocarbonyl C–S bonds of the corresponding betaines. A hexanuclear derivative, [Ru6{μ3‐κ4C2,N,S‐S(CH)2N(Me)CCNPh}2(μ4‐S)2(CO)14] (3), has also been obtained from the reaction involving TMe–C(S)NPh. This product arises not only from the cleavage of the betaine thiocarbonyl C–S bond, but also from the additional activation of the C–S bond within the thiazole ring.
Post‐glacial range of variability in the Conejos River Valley, southern Colorado, USA: fluvial response to climate change and sediment supply
Authors: Layzell Anthony L. , Eppes Martha Cary , Johnson Bradley G. , Diemer John A.
Published: April 2012

Effective river management strategies require an understanding of how fluvial processes vary both spatially and temporally. Here, we examine the natural range of variability in the Conejos River Valley, southern Colorado, through documentation of terrace morphostratigraphic and sedimentological characteristics as well as through investigation of sediment contributions from headwaters, hillslopes and tributary streams. Additionally, soil development and radiocarbon ages, together with local and regional paleoclimate reconstructions, were used to infer the range of processes acting in this system.

Since de‐glaciation, the Conejos River has fluctuated between episodes of bedrock strath formation, aggradation and vertical incision. Morphostratigraphic relationships, soil development and radiocarbon ages enable us to propose a chronology for periods of alluvial deposition (around 8·9–7·6 ka, 5·5 ka and from 3·5 to 1·1 ka), separated by intervals of fluvial incision. We infer potential forcing mechanisms by utilizing multiple working hypotheses. Specifically, we discuss the potential for increases in sediment supply during periods of (1) para‐glacial adjustment, (2) climatic cooling, (3) increased frequency of climate change and (4) increased fire frequency or severity. We also consider the effects of changes in stream discharge and extreme storm occurrence. We conclude that combinations of these processes, operating at different times, have contributed to sediment mobilization since de‐glaciation. Stream and landform morphology also varies longitudinally due to the influence of remnant glacial topography. In particular, valley bottom overdeepening at tributary junctions has resulted in incision and strath formation into unlithified glacial deposits (i.e. fill‐cut terraces) rather than bedrock in some reaches. Overall, the Conejos fluvial system has varied significantly both temporally and spatially since de‐glaciation and appears to be sensitive to changes in sediment supply related to Holocene scale climate fluctuations. This natural range of variability must therefore be a key consideration in any future stream management policies. Copyright © 2012 John Wiley & Sons, Ltd.
Surface lowering of limestone pavement as determined by cosmogenic (36Cl) analysis
Authors: Wilson Peter , Barrows Timothy T. , Lord Tom C. , Vincent Peter J.
Published: April 2012

Determination of the rate and total amount of limestone pavement surface lowering is a critical issue in developing models of regional landscape change in limestone terrain. Erratic‐capped pedestals have frequently been used for this purpose but problems concerning definition and measurement of pedestal height, and the absence of a secure timeframe for erratic emplacement, have resulted in conflicting interpretations. We have used cosmogenic (36Cl) to establish the emplacement age of erratic boulders and the total amount of pavement surface lowering at sites in northwest England. Since erratic emplacement at 17.9 ka the limestone pavement has been lowered by 22–45 cm (average: 33 ± 10 cm), assuming lowering was continuous. Although indicating some spatial heterogeneity, the results contrast with earlier reported values based on the measurement of pedestal heights and inferred age for deglaciation. We consider that changes in climate and the character and duration of regolith covers to have been important influences in promoting surface lowering. It is argued that nivation (chemical and mechanical snow‐related processes) associated with several cool/cold periods is likely to have played an important role in surface lowering. Complicating factors associated with surface lowering (thickness and longevity of snow and regolith covers) are identified but as yet cannot be quantified. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of C60 on the Salmonella typhimurium TA100 transcriptome expression: Insights into C60-mediated growth inhibition and mutagenicity
Authors: Hancock Dawn E. , Indest Karl J. , Gust Kurt A. , Kennedy Alan J.
Published: April 2012

Rapid advances are being made in the creation and use of nanomaterials, but little is known about the impact these materials might have on key microbial functions if introduced into the environment. Previous studies have generated conflicting results with respect to the impact of fullerenes on microbial activity. In the present study, Salmonella typhimurium TA100 was selected as a model microbial system with which to investigate further the impact of C60 aggregates on microbial growth, mutagenicity, and global transcript expression. Aggregates of C60 predominantly less than 100 nm significantly impacted Salmonella growth at concentrations of ≥0.5 mg/L. In addition, C60 aggregates also displayed mutagenic potential at concentrations ≥0.1 mg/L. Transcript expression analysis of S. typhimurium TA100 exposed to C60 for 24 h indicated that 271 transcripts had significant differential expression relative to controls with twofold or more change. Of particular interest was the increased expression of transcripts coding for proteins involved in energy metabolism, amino acid biosynthesis, transcription, and DNA metabolism, and the decreased expression of transcripts coding for proteins involved in protein fate, transport, and binding and bacterial secretion systems. Collectively, these data indicate that C60 interacts with the outer membrane of S. typhimurium TA100, resulting in delayed growth and mutagenicity, most likely by interfering with key transport functions and inducing a stress response, respectively. Environ. Toxicol. Chem. 2012; 31: 1438–1444. © 2012 SETAC
Effects of chronic copper exposure on development and survival in the southern leopard frog (Lithobates [Rana] sphenocephalus)
Authors: Lance Stacey L. , Erickson Matthew R. , Flynn R. Wesley , Mills Gary L. , Tuberville Tracey D. , Scott David E.
Published: April 2012

Exposure to environmental contaminants contributes to the global decline of amphibian populations. The impacts of organic contaminants on amphibians are well documented. However, substantially less is known concerning the potential effects of metals on amphibian populations. Copper (Cu) is an essential element, but it can be toxic at concentrations only slightly higher than the normal physiological range. The present study examines the effects of chronic Cu exposure on embryos and larvae of southern leopard frogs, Lithobates (Rana) sphenocephalus. Groups of eggs from multiple clutches were collected from two wetlands and exposed to a range of Cu concentrations (0–150 µg/L) until they reached the free-swimming stage, and then individual larvae were reared to metamorphosis. Higher Cu concentrations significantly reduced embryo survival to the free-swimming stage but did not further reduce survival to metamorphosis. Larval period was affected by Cu treatment, but the clutch from which larvae originated (i.e., parentage) explained a higher proportion of the variation. Embryo survival to hatching varied significantly among clutches, ranging from 42.9 to 79.2%. Measurable levels of Cu were found in larvae with body burdens up to 595 µg Cu/g dry mass in the 100 µg/L treatment, and larval Cu body burdens were higher than in metamorphs. The present study also demonstrated that higher initial egg density ameliorated embryo mortality at higher Cu levels and should be accounted for in future studies. Environ. Toxicol. Chem. 2012; 31: 1587–1594. © 2012 SETAC
A novel multidimensional solution reconstruction and edge‐based limiting procedure for unstructured cell‐centered finite volumes with application to shallow water dynamics
Authors: Delis A. I. , Nikolos I. K.
Published: April 2012

On unstructured meshes, the cell‐centered finite volume (CCFV) formulation, where the finite control volumes are the mesh elements themselves, is probably the most used formulation for numerically solving the two‐dimensional nonlinear shallow water equations and hyperbolic conservation laws in general. Within this CCFV framework, second‐order spatial accuracy is achieved with a Monotone Upstream‐centered Schemes for Conservation Laws‐type (MUSCL) linear reconstruction technique, where a novel edge‐based multidimensional limiting procedure is derived for the control of the total variation of the reconstructed field. To this end, a relatively simple, but very effective modification to a reconstruction procedure for CCFV schemes, is introduced, which takes into account geometrical characteristics of computational triangular meshes. The proposed strategy is shown not to suffer from loss of accuracy on grids with poor connectivity. We apply this reconstruction in the development of a second‐order well‐balanced Godunov‐type scheme for the simulation of unsteady two‐dimensional flows over arbitrary topography with wetting and drying on triangular meshes. Although the proposed limited reconstruction is independent from the Riemann solver used, the well‐known approximate Riemann solver of Roe is utilized to compute the numerical fluxes, whereas the Green–Gauss divergence formulation for gradient computations is implemented. Two different stencils for the Green–Gauss gradient computations are implemented and critically tested, in conjunction with the proposed limiting strategy, on various grid types, for smooth and nonsmooth flow conditions. Copyright © 2012 John Wiley & Sons, Ltd.
An empirical method for approximating canopy throughfall
Authors: Trinh Dieu Huong , Chui Ting Fong May
Published: April 2012

Rainfall replenishes surface and subsurface water but is partially intercepted by a canopy. However, it is challenging to quantify the rainfall passing through the canopy (i.e. throughfall). This study derives simple‐to‐use empirical equations relating throughfall to canopy and rainfall characteristics. Monthly throughfall is calculated by applying a mass balance model on weather data from Singapore; Vancouver, Canada; and Stanford, USA. Regression analysis is then performed on the calculated throughfall with three dependent variables (i.e. maximum canopy storage, average rainfall depth and time interval between two consecutive rainfall in a month) to derive the empirical equations. One local equation is derived for each location using data from that particular location, and one global equation is derived using data from all three locations. The equations are further verified with calculated monthly throughfall from other weather data and actual throughfall field measurements, giving an accuracy of about 80–90%. The global equation is relatively less accurate but is applicable worldwide. Overall, this study provides a global equation through which one can quickly estimate throughfall with only information on the three variables. When additional weather data are available, one can follow the proposed methodology to derive their own equations for better estimates. Copyright © 2012 John Wiley & Sons, Ltd.
Modelling of hydrogeochemical potential of three lake catchments in Polesie region (Eastern Poland)
Authors: Dawidek Jarosław , Ferencz Beata , Sobolewski Wojciech
Published: April 2012

Total dissolved solids (TDS) in lake and catchment water is a result of geological structure, as well as duration of rock and water contact and human activity. In this paper, a potential dissolved solids (PtDS) in three Łęczna–Włodawa Lake catchments was determined using extraction and computer software (GIS and AquaChem). Human pressure on water quality was estimated as a difference of the TDS and a catchment hydrogeochemical potential (TPtDS, total potential dissolved solids). TPtDS coefficient included hydrogeological features of the aquifer, soil cover impact on infiltrated water quality, and sediments susceptibility to denudation. The main advantage of the model is a possibility of its employment for every catchment or other areas (e.g. administrative) on both microscale and mesoscale. The highest TPtDS occurred in the catchment, favoured with underground supply, which was located in the vicinity of the Cretaceous mesoregional unit (Chełm Hills). The lowest value was observed in the catchment built with organogenic sediments and coarse material. A seasonal constancy of TPtDS values proved a stability of the lake‐catchment systems under study. Copyright © 2012 John Wiley & Sons, Ltd.
Multi‐site evaluation of hydrology component of SWAT in the coastal plain of southwest Georgia
Authors: Cho Jaepil , Bosch David , Vellidis George , Lowrance Richard , Strickland Timothy
Published: April 2012

Simulation of watershed scale hydrologic and water quality processes is important for watershed assessments. Proper characterization of the accuracy of these simulations, particularly in cases with limited observed data, is critical. The Soil & Water Assessment Tool (SWAT) is frequently used for watershed scale simulation. The accuracy of the model was assessed by extrapolating calibration results from a well studied Coastal Plain watershed in Southwest Georgia, USA, to watersheds within the same geographic region without further calibration. SWAT was calibrated and validated on a 16.7‐km2 subwatershed within the Little River Experimental Watershed by varying six model parameters. The optimized parameter set was then applied to a watershed of similar land use and soils, a smaller watershed with different land use and soils and three larger watersheds within the same drainage system without further calibration. Simulation results with percent bias (PB) ±15% ≤ PB < ±25% and Nash–Sutcliffe efficiency (NSE) 0.50 < NSE ≤ 0.65 were considered to be satisfactory, whereas those with PB < ±10% and 0.75 < NSE ≤ 1.00 were considered very good. With these criteria, simulation results for the five non‐calibration watersheds were satisfactory to very good. Differences across watersheds were attributed to differences in soils, land use, and surficial aquifer characteristics. These results indicate that SWAT can be a useful tool for predicting streamflow for ungauged watersheds with similar physical characteristics to the calibration watershed studied here and provide an indication of the accuracy of hydrologic simulations for ungauged watersheds. Copyright © 2012 John Wiley & Sons, Ltd.
Neural invasion induces cachexia via astrocytic activation of neural route in pancreatic cancer
Authors: Imoto Akira , Mitsunaga Shuichi , Inagaki Masatoshi , Aoyagi Kazuhiko , Sasaki Hiroki , Ikeda Masafumi , Nakachi Kohei , Higuchi Kazuhide , Ochiai Atsushi
Published: April 2012

Pancreatic cancer is characterized by a high frequency of cachexia, pain and neural invasion (N‐inv). Neural damage is occurred by N‐inv and modulates pain and muscle atrophy via the activation of astrocyte in the connected spine. The activated astrocyte by N‐inv, thus, may affect cachexia in pancreatic cancer. Clinical studies in patients and autopsy cases with pancreatic cancer have revealed that N‐inv is related to cachexia and astrocytic activation. We established a novel murine model of cancer cachexia using N‐inv of human pancreatic cancer cells. Mice with N‐inv showed a loss of body weight, skeletal muscle and fat mass without appetite loss, which are compatible with an animal model of cancer cachexia. Activation of astrocytes in the spinal cord connected with N‐inv was observed in our model. Experimental cachexia was suppressed by disrupting neural routes or inhibiting the activation of astrocytes. These data provide the first evidence that N‐inv induces cachexia via astrocytic activation of neural route in pancreatic cancer.
Combinatorial treatment of mammospheres with trastuzumab and salinomycin efficiently targets HER2‐positive cancer cells and cancer stem cells
Authors: Oak Prajakta S. , Kopp Florian , Thakur Chitra , Ellwart Joachim W. , Rapp Ulf R. , Ullrich Axel , Wagner Ernst , Knyazev Pjotr , Roidl Andreas
Published: April 2012

A major obstacle in the successful treatment of cancer is the occurrence of chemoresistance. Cancer cells surviving chemotherapy and giving rise to a recurrence of the tumor are termed cancer stem cells and can be identified by elevated levels of certain stem cell markers. Eradication of this cell population is a priority objective in cancer therapy. Here, we report elevated levels of stem cell markers in MCF‐7 mammospheres. Likewise, an upregulation of HER2 and its differential expression within individual cells of mammospheres was observed. Sorting for HER2high and HER2low cells revealed an upregulation of stem cell markers NANOG, OCT4 and SOX2 in the HER2low cell fraction. Accordingly, HER2low cells also showed reduced proliferation, ductal‐like outgrowths and an increased number of colonies in matrigel. Xenografts from subcutaneously injected HER2low sorted cells exihibited earlier onset but slower growth of tumors and an increase in stem cell markers compared to tumors developed from the HER2high fraction. Treatment of mammospheres with salinomycin reduced the expression of SOX2 indicating a selective targeting of cancer stem cells. Trastuzumab however, did not reduce the expression of SOX2 in mammospheres. Furthermore, a combinatorial treatment of mammospheres with trastuzumab and salinomycin was superior to single treatment with each drug. Thus, targeting HER2 expressing tumors with anti‐HER2 therapies will not necessarily eliminate cancer stem cells and may lead to a more aggressive cancer cell phenotype. Our study demonstrates efficient killing of both HER2 positive cells and cancer stem cells, hence opening a possibility for a new combinatorial treatment strategy.
Modest increase in risk of specific types of cancer types in type 2 diabetes mellitus patients
Authors: Lo Sui‐Foon , Chang Shih‐Ni , Muo Chih‐Hsin , Chen Shih‐Yin , Liao Fang‐Yin , Dee Shu‐Wei , Chen Pei‐Chun , Sung Fung‐Chang
Published: April 2012

Most studies associated diabetes mellitus (DM) with risk of cancer have focused on the Caucasian population and only a few types of cancer. Therefore, a large and comprehensive nationwide retrospective cohort study involving an Asian population was conducted to evaluate the risk of several major types of cancer among Type 2 DM patients. The study analyzed the nationwide population‐based database from 1996 to 2009 released by the National Health Research Institute in Taiwan. Incidence and hazard ratios (HRs) were calculated for specific types of cancer. The overall risk of cancers was significantly greater in the DM cohort [N = 895,434; HR = 1.19, 95% confidence interval (CI) = 1.17–1.20], compared with non‐DM controls (N = 895,434). Several organs in the digestive and urogenital systems showed increased risk of cancer. The three highest HRs were obtained from cancers of the liver (HR = 1.78, 95% CI = 1.73–1.84), pancreatic (HR = 1.52, 95% CI = 1.40–1.65), and uterus and corpus (HR = 1.38, 95% CI = 1.22–1.55). The risk increased with age, and men with DM aged ≥75 years exhibited the highest risk (HR = 7.76, 95% CI = 7.39–8.15). Subjects with DM in this population have a modest increased risk of cancer, similar to the Caucasian population for several specific types of cancer. Old men with DM have the highest risk of cancer. Careful screening for cancer in DM patients is important for early diagnosis and effective treatment.
Three‐dimensional vascularization of electrospun PCL/collagen‐blend nanofibrous scaffoldsin vivo
Authors: Klumpp Dorothee , Rudisile Markus , Kühnle Romina I. , Hess Andreas , Bitto Franz F. , Arkudas Andreas , Bleiziffer Oliver , Boos Anja M. , Kneser Ulrich , Horch Raymund E. , Beier Justus P.
Published: April 2012

Nanofiber scaffolds have proven their various advantages for tissue engineering and have been analyzed extensively. However, to date the three‐dimensional pattern of vascularization inside nanofibrous scaffolds is unknown. This study introduces a novel method to visualize and quantify vascularization of electrospun nanofibrous PCL/collagen scaffolds in 3Din vivo. Randomly spun PCL/collagen blend and parallel aligned PCL/collagen blend/PEO scaffolds were analyzed for numbers and patterns of sprouting vessels inside the constructs using microCT scans at different time points. The image data derived from the microCT scans was converted into three‐dimensional vessel trees. The aligned scaffold showed a significantly smaller number of sprouting vessels but vascularization in the center of the constructs occurred considerably earlier than in the nonwoven scaffold. Thus, for the first time the actual pattern of vascularization in nanofibrous scaffolds can be visualized three‐dimensionally. These results demonstrate that the 3D pattern of vessel trees could be an essential parameter to evaluate nanofiber scaffolds for their suitability for tissue engineering as well asin vivoapplications in general. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2302–2311, 2012.
Aerobic Swimming Performance of Juvenile Largemouth Bronze Gudgeon (Coreius guichenoti) in the Yangtze River
Authors: TU ZHIYING , LI LIPING , YUAN XI , HUANG YINGPING , JOHNSON DAVID
Published: April 2012

Largemouth bronze gudgeon (Coreius guichenoti), a fish species once abundant in the Yangtze River, has been rapidly declining in recent years. One important factor, among many, is the interruption of the free‐flowing rivers by dams. To obtain data that can be applied to the design of an effective fishway for C. guichenoti and other species in the fish community, a laboratory study of juvenile C. guichenoti's swimming ability and energetics was conducted in a flume‐type respirometer equipped with a high‐speed video camera system to record swimming behavior. The critical swimming speed (Ucrit), standard metabolic rate (SMR), and maximum metabolic rate (MO2,max) were determined during steady swimming at four water temperatures (10, 15, 20, and 25°C). A power function accurately describes the relationship between oxygen consumption rate (MO2) and swimming speed (U) at the four temperatures. The Ucrit, SMR, MO2,max, and metabolic scope increased with increasing temperature. The relationship between cost of transport (COT) and U was characteristically inverse bell‐shaped, with minimum COT at Uopt = 4.5–5.0 body lengths per second (bl sec−1). This investigation provides data on the swimming ability of C. guichenoti that will add to the basic science required for fishway design. J. Exp. Zool.317:294–302, 2012. © 2012 Wiley Periodicals, Inc.
Creativity, Problem Solving, and Solution Set Sightedness: Radically Reformulating BVSR
Authors: Simonton Dean Keith
Published: April 2012

Too often, psychological debates become polarized into dichotomous positions. Such polarization may have occurred with respect to Campbell's (1960) blind variation and selective retention (BVSR) theory of creativity. To resolve this unnecessary controversy, BVSR was radically reformulated with respect to creative problem solving. The reformulation began by defining (a) potential solution sets consisting of k possible solutions each described by their respective probability and utility values, (b) a set sightedness metric that gauges the extent to which the probabilities correspond to the utilities, and (c) a solution creativity index based on the joint improbability and utility of each solution. These definitions are then applied to representative cases in which simultaneous or sequential generate‐and‐test procedures scrutinize solution sets of variable size and with representative patterns of probabilities and utilities. The principal features of BVSR theory were then derived, including the implications of superfluity and backtracking. Critically, it was formally demonstrated that the most creative solutions must emerge from solution sets that score extremely low in sightedness. Although this preliminary revision has ample room for further development, the demonstration proves that BVSR's explanatory value does not depend on any specious association with Darwin's theory of evolution.
Mechanical strengthening of fiberoptic microneedles using an elastomeric support
Authors: Kosoglu Mehmet A. , Hood R. Lyle , Rylander Christopher G.
Published: April 2012

Background and Objectives

Microneedles made from silica fiberoptics permit transmission and collection of light, which is an important functional advantage over metal or silicon microneedles. This added functionality may enhance or even enable new percutaneous light‐based clinical diagnostic and therapeutic procedures. Micron‐diameter fiberoptic microneedles, created from solid fibers capable of light emission and detection, are designed to penetrate several millimeters into tissue while minimizing tissue invasion and disruption. The mechanical strength (critical buckling force) of high aspect ratio (length to diameter) microneedles is a potential problem, which has motivated our invention of an elastomeric support device. In this study, we have tested our hypothesis that embedding the microneedles in an elastomeric support medium may increase microneedle critical buckling force.

Materials and Methods

The critical buckling force of silica microneedles with 55, 70, and 110 µm diameters and 3 mm lengths were measured with and without a surrounding elastomeric support (PDMS, polydimethylsiloxane). These experimental results were compared to theoretical calculations generated by the Rayleigh–Ritz buckling model. The insertion force required to penetrate ex vivo porcine skin was measured for microneedles with 55 and 70 µm diameters.

Results

Use of the PDMS support increased critical buckling force for microneedles of 55, 70, and 110 µm diameters by an average of 610%, 290%, and 33%, respectively. Theoretical calculations by the Rayleigh–Ritz model consistently overestimated the experimentally determined strengthening, but correlated highly with the greater enhancement offered to thinner microneedles. Aided by mechanical strengthening, microneedles 55 µm in diameter were able to repeatedly penetrate.

Conclusions

The critical buckling force of microneedles can be increased substantially to allow extremely high‐aspect ratio microneedles, 55–110 µm in diameter and 3 mm in length, to penetrate ex vivo porcine skin. By this strengthening method, the safety and reliability of microneedles in potential clinical applications can be considerably enhanced. Lasers Surg. Med. 44: 421–428, 2012. © 2012 Wiley Periodicals, Inc.
Magnetically Responsive Inorganic/Polydiacetylene Nanohybrids
Authors: Lee Joosub , Yoon Bora , Ham Dae‐Young , Yarimaga Oktay , Lee Chan Woo , Jaworski Justyn , Kim Jong‐Man
Published: April 2012

A direct method for the generation of magnetically responsive conjugated polymer supramolecules is described. By immobilizing magnetite nanoparticles (MNP) on the surface of polydiacetylene (PDA) supramolecules, an inorganic/conjugated polymer hybrid system results that enables the incorporation of an important property (magnetism) to an attractive class of colorimetric PDA sensors. Benefits of this new system include: (1) ease of preparation, (2) variability in diacetylene labeling of MNPs, (3) diversity in conjugated PDA morphologies, (4) facile isolation process, and (5) immobilization of the PDA without altering the colorimetric (sensory) properties. It is demonstrated that PDA/MNP systems offer advantages in applications including film formation, separation, and sensing.
Combining Modular Ligation and Supramolecular Self‐Assembly for the Construction of Star‐Shaped Macromolecules
Authors: Altintas Ozcan , Muller Thierry , Lejeune Elise , Plietzsch Oliver , Bräse Stefan , Barner‐Kowollik Christopher
Published: April 2012

A well‐defined random copolymer of styrene (S) and chloromethylstyrene (CMS) featuring lateral chlorine moieties with an alkyne terminal group is prepared (P(S‐co‐CMS), = 5500 Da, PDI = 1.13). The chloromethyl groups are converted into Hamilton wedge (HW) entities (P(S‐co‐HWS), = 6200 Da, PDI = 1.13). The P(S‐co‐HWS) polymer is subsequently ligated with tetrakis(4‐azidophenyl)methane to give HW‐functional star‐shaped macromolecules (P(S‐co‐HWS))4, = 25 100 Da, PDI = 1.08). Supramolecular star‐shaped copolymers are then prepared via self‐assembly between the HW‐functionalized four‐arm star‐shaped macromolecules (P(S‐co‐HW))4 and cyanuric acid (CA) end‐functionalized PS (PS–CA, = 3700 Da, PDI = 1.04), CA end‐functionalized poly(methyl methacrylate) (PMMA–CA, = 8500 Da, PDI = 1.13) and CA end‐functionalized polyethylene glycol (PEG–CA, = 1700 Da, PDI = 1.05). The self‐assembly is monitored by 1H NMR spectroscopy and light scattering analyses.
Synthesis and Thermal Behavior of Polyamide 12,T Random and Block Copolymers
Authors: Novitsky Theodore F. , Mathias Lon J. , Osborn Scott , Ayotte Roger , Manning Steven
Published: April 2012

PA‐12,T was synthesized by melt condensation of 1,12‐diaminododecane (DA) and terephthalic acid salt and by solution polymerization of biscaprolactam terephthalamide (BCT) and DA in molten caprolactam. Stoichiometry of both methods were varied from 10 mol‐% excess terephthalic acid (or BCT) and 10 mol‐% excess DA and the impact on intrinsic viscosity, end group concentration and end group functionality was examined. PA‐12,T salt was then copolymerized with PA‐6,T salt and melting behavior was determined to examine the effect of random comonomers. Block copolymers were synthesized by anionic polymerization of PA‐6 with PA‐12,T macro‐coinitiators formed from the solution step‐growth reaction. The melting and solubility properties of the block copolymers were then correlated with the PA‐12,T block size and compared to randomly formed copolymers.
Surface Modification of Clay and Use as Stabilizer in Miniemulsion Polymerization
Authors: van den Dungen Eric T. A. , Galineau Jeremy , Hartmann Patrice C.
Published: April 2012

Poly(styrene‐co‐butyl acrylate) latexes were successfully synthesized via Pickering miniemulsion polymerization, using modified Montmorillonite clay as the exclusive stabilizer. The latexes were stable to relatively high concentration of electrolyte due to the presence of the clay at the interface, providing both a physical barrier and electrostatic stabilization. Film formation could be done at room temperature, but the barrier properties to water and oil were poor. This was attributed to compartmentalization of the film, where the morphology of the latex particles was retained.