bluuebunny/crossref_metadata_2025_split huggingface dataset:
Equatorial upwelling enhances nitrogen fixation in the Atlantic Ocean
Authors: Subramaniam Ajit , Mahaffey Claire , Johns William , Mahowald Natalie 
Published: February 2013

AbstractSurface waters in upwelling regions are thought to be nutrient rich and hence inhibit nitrogen fixation (diazotrophy) because diazotrophs can preferentially assimilate nitrate and ammonia instead of expending energy to fix dinitrogen. We found average nitrogen fixation rates to be two to seven times higher in the surface waters of the upwelling region of the eastern equatorial Atlantic than typically measured here during non‐upwelling periods. We posit that in this region, low nitrate‐phosphate ratio waters are upwelled, and an initial bloom of non‐diazotrophic phytoplankton removes recently upwelled nitrate. Thereby, diazotrophy is fuelled by residual phosphate and by a combination of aeolian and upwelled sources of iron. Annually, we estimate that approximately 47 Gmol of new nitrogen is introduced by diazotrophy in upwelled waters alone and 195 Gmol N is fixed in the equatorial Atlantic region. Our findings challenge the paradigm that the highest nitrogen fixation rates occur in oligotrophic gyres and instead provide evidence of its importance in upwelling regimes where phosphate‐ and iron‐rich waters rich are upwelled.
Maintenance of long‐term potentiation in hippocampal mossy fiber—CA3 pathway requires fine‐tuned MMP‐9 proteolytic activity
Authors: Wiera Grzegorz , Wozniak Grazyna , Bajor Malgorzata , Kaczmarek Leszek , Mozrzymas Jerzy W. 
Published: February 2013

AbstractMechanisms of synaptic plasticity involve proteolytic activity mediated by a complex system of proteases, including members of metalloproteinase (MMP) family. In particular, MMP‐9 is critical in LTP maintenance in the Schaffer collateral‐CA1 pathway and in the acquisition of hippocampus‐dependent memory. Recent studies from this laboratory revealed that in the mossy fiber‐CA3 (MF‐CA3) projection, where LTP induction and expression are largely presynaptic, MMPs blockade disrupts LTP maintenance and that LTP induction is associated with increased MMP‐9 expression. Here we used acute brain slices from MMP‐9 knock‐out mice and transgenic rats overexpressing MMP‐9 to determine how manipulations in endogenous MMP‐9 affect LTP in the MF‐CA3 projection. Both types of transgenic models showed a normal basal synaptic transmission and short‐term plasticity. Interestingly, the maintenance of LTP induced in slices from knock‐out mice and overexpressing rats was nearly abolished. However, in the presence of active MMP‐9, a gradual fEPSP autopotentiation was observed and tetanization evoked a marked LTP in knock‐out mice. Additionally, in MMP‐9‐treated slices from wild‐type mice, fEPSP autopotentiation also occurred and partially occluded LTP. This indicates that exogenous protease can restore LTP in null mice whereas in the wild‐type, MMP‐9 excess impairs LTP. We expected that LTP maintenance in transgenic rats could be re‐established by a partial MMP blockade but non‐saturating concentrations of MMP inhibitor were ineffective. In conclusion, we demonstrate that LTP maintenance in MF‐CA3 pathway requires fine‐tuned MMP‐9 activity and raises the possibility that altered MMP‐9 level might be detrimental for cognitive processes as observed in some neuropathologies. © 2013 Wiley Periodicals, Inc.
Early postnatal virus inoculation into the scala media achieved extensive expression of exogenous green fluorescent protein in the inner ear and preserved auditory brainstem response thresholds
Authors: Wang Yunfeng , Sun Yu , Chang Qing , Ahmad Shoeb , Zhou Binfei , Kim Yeunjung , Li Huawei , Lin Xi 
Published: February 2013

AbstractBackgroundGene transfer into the inner ear is a promising approach for treating sensorineural hearing loss. The special electrochemical environment of the scala media raises a formidable challenge for effective gene delivery at the same time as keeping normal cochlear function intact. The present study aimed to define a suitable strategy for preserving hearing after viral inoculation directly into the scala media performed at various postnatal developmental stages.MethodsWe assessed transgene expression of green fluorescent protein (GFP) mediated by various types of adeno‐associated virus (AAV) and lentivirus (LV) in the mouse cochlea. Auditory brainstem responses were measured 30 days after inoculation to assess effects on hearing.ResultsPatterns of GFP expression confirmed extensive exogenous gene expression in various types of cells lining the endolymphatic space. The use of different viral vectors and promoters resulted in specific cellular GFP expression patterns. AAV2/1 with cytomegalovirus promoter apparently gave the best results for GFP expression in the supporting cells. Histological examination showed normal cochlear morphology and no hair cell loss after either AAV or LV injections. We found that hearing thresholds were not significantly changed when the injections were performed in mice younger than postnatal day 5, regardless of the type of virus tested.ConclusionsViral inoculation and expression in the inner ear for the restoration of hearing must not damage cochlear function. Using normal hearing mice as a model, we have achieved this necessary step, which is required for the treatment of many types of congenital deafness that require early intervention. Copyright © 2013 John Wiley & Sons, Ltd.
Spatio‐temporal features of permafrost thaw projected from long‐term high‐resolution modeling for a region in the Hudson Bay Lowlands in Canada
Authors: Zhang Yu 
Published: February 2013

AbstractAlthough studies agree that climate warming will cause permafrost thaw, projected permafrost conditions differ widely, and most projections use half degree latitude/longitude or coarser spatial resolution. Using a process‐based model, this study projected changes of permafrost from 2010 to 2200 at 30 m by 30 m resolution for a region in the northwest of the Hudson Bay Lowlands in Canada. This long‐term spatially detailed modeling revealed some general features of permafrost dynamics with climate warming. Temporally, permafrost degradation at a site can be divided into five stages: gradual‐thawing stage, increased‐thawing stage, frequent‐talik stage, isothermal‐permafrost stage, and permafrost‐free stage. This study determined the beginning or ends of the stages for each grid cell and mapped the degradation stages in this region. Spatially, permafrost was predicted to become increasingly discontinuous with climate warming. By the end of the 22nd century, only 20% to 65% of the land area in this region will be underlain by permafrost. With the formation of taliks, the maximum summer thaw depth will increase significantly, and near‐surface permafrost will disappear in many areas while permafrost at depth can persist for decades. Thus, the spatial distribution of near‐surface permafrost and permafrost at depth can be very different. This study also shows that climate scenarios, the depth of permafrost considered, spatial resolution and associated ground conditions used for modeling could cause significant differences in permafrost projections.
Case report: Severe disseminated adenovirus infection in a neonate following water birth delivery
Authors: Soileau Stacey L. , Schneider Eileen , Erdman Dean D. , Lu Xiaoyan , Ryan William D. , McAdams Ryan M. 
Published: February 2013

AbstractAdenovirus infections are a common cause of respiratory and enteric illnesses of late infancy and childhood. In neonates, adenovirus infections are rare, carrying a high morbidity and mortality rate. We present a case of infant who developed severe pneumonia and disseminated adenoviral infection following water birth delivery to a mother with gastroenteritis. The infant's infection was due to an adenovirus strain that has not been previously reported in neonates. J. Med. Virol. 85:667–669, 2013. © 2013 Wiley Periodicals, Inc.
Viewing angle switchable blue‐phase liquid crystal display with low voltage and high transmittance
Authors: Yuan Ling , Cui Jian‐Peng , Li Da‐Hai , Wang Qiong‐Hua 
Published: February 2013

AbstractWe propose a viewing angle switchable blue‐phase liquid crystal display with low voltage and high transmittance. In this device, in‐plane protrusions are used to lower operating voltage and improve the transmittance. Besides, the top electrode can control viewing angle of the proposed display. When no voltage is applied to the top electrode, the display shows wide viewing angle mode. On the contrary, this display shows narrow viewing angle mode. So, this device exhibits low operating voltage, high transmittance, and good viewing angle controllable characteristics.
Successful treatment of pediatric plasmacytoid dendritic cell tumors with a contemporary regimen for acute lymphoblastic leukemia
Authors: Wright Karen D. , Onciu Mihaela M. , Coustan‐Smith Elaine , Campana Dario , Raimondi Susana C. , Inaba Hiroto , Ribeiro Raul , Pui Ching‐Hon , Sandlund John T. 
Published: February 2013

AbstractDendritic cell leukemia (DCL) or hematodermic tumor is an uncommon subtype of acute leukemia. In contrast to adult cases, children tend to have a less aggressive course. The diagnosis of DCL should be considered when its characteristic morphologic features are present and leukemic cells co‐express CD4 and CD56. Cases of DCL among pediatric patients have been reported to respond to therapeutic regimens for acute lymphoblastic leukemia, but details regarding the specifics of therapy are lacking. Pediatr Blood Cancer 2013; 60: E38–E41. © 2013 Wiley Periodicals, Inc.
Prompt administration of antibiotics is associated with improved outcomes in febrile neutropenia in children with cancer
Authors: Fletcher Matthew , Hodgkiss Hailey , Zhang Song , Browning Rachel , Hadden Colleen , Hoffman Tanja , Winick Naomi , McCavit Timothy L. 
Published: February 2013

AbstractBackgroundTime‐to‐antibiotic (TTA) administration is a widely used quality‐of‐care measure for children with cancer and febrile neutropenia (FN). We sought to determine whether TTA is associated with outcomes of FN.ProcedureA single‐center, retrospective cohort study was conducted of 1,628 FN admissions from 653 patients from 2001 to 2009. Outcome variables included (1) an adverse event (AE) composite of in‐hospital mortality, pediatric intensive care unit (PICU) admission within 24 hours of presentation, and/or fluid resuscitation ≥40 ml/kg within 24 hours of presentation and (2) length of stay (LOS). TTA was measured as a continuous variable and in 60‐minute intervals. Mixed regression models were constructed to evaluate associations of TTA with the outcome variables after adjusting for relevant covariates including cancer diagnosis, degree of myelosuppression, and presence of bacteremia.ResultsThe composite AE outcome occurred in 11.1% of admissions including 0.7% in‐hospital mortality, 4.7% PICU admission, and 10.1% fluid resuscitation. In univariate analysis, TTA was associated with the composite AE outcome (Odds Ratio [OR] 1.29, 95% CI 1.02–1.64) but not LOS. In multivariate analysis, after adjustment for relevant covariates, 60‐minute TTA intervals were associated with the composite AE outcome (61–120 minutes vs. ≤60 minutes, OR 1.81, 95% CI 1.01–3.26). Unexpectedly, admission from the emergency department (ED) was also independently associated with the composite AE outcome (ED vs. clinic, OR 3.15, 95% CI 1.95–5.09).ConclusionsTTA and presentation to the ED are independently associated with poor outcomes of FN. Pediatr Blood Cancer 2013;60:1299–1306. © 2013 Wiley Periodicals, Inc.
Exploring barriers and facilitators to clinical trial enrollment in the context of sickle cell anemia and hydroxyurea
Authors: Lebensburger Jeffrey D. , Sidonio Robert F. , DeBaun Michael R. , Safford Monika M. , Howard Thomas H. , Scarinci Isabel C. 
Published: February 2013

AbstractBackgroundSeveral sickle cell clinical trials have closed due to inability to enroll patients. To limit the early cessation of a proposed clinical trial due to low accrual rates, we sought to better understand barriers and facilitators to enrolling parents of children with sickle cell anemia (SCD) into clinical trials.ProcedureFocus groups (n = 3) were conducted with parents/guardians (n = 14) who had not previously been recruited for a clinical trial and were not administering hydroxyurea to their children.ResultsThree main themes related to barriers to clinical trial enrollment were identified during analysis of focus groups: general barriers to health related research (general mistrust of research studies, emotional and practical concerns), barriers to trial design (randomization), and barriers to hydroxyurea (long term unknown risks, cancer, myelosuppressive effects). Facilitators identified were need for more education, including request for peer education, and improved explanation of clinical trials or study rationale.ConclusionEngagement of parents/guardians of children with SCD in identifying barriers and facilitators to clinical trial enrollment may be critical to the development of strategies to enhance SCD trial completion. Pediatr Blood Cancer 2013;60:1333–1337. © 2013 Wiley Periodicals, Inc.
Relevance of historical therapeutic approaches to the contemporary treatment of pediatric solid tumors
Authors: Green Daniel M. , Kun Larry E. , Matthay Katherine K. , Meadows Anna T. , Meyer William H. , Meyers Paul A. , Spunt Sheri L. , Robison Leslie L. , Hudson Melissa M. 
Published: February 2013

AbstractChildren with solid tumors, most of which are malignant, have an excellent prognosis when treated on contemporary regimens. These regimens, which incorporate chemotherapeutic agents and treatment modalities used for many decades, have evolved to improve relapse‐free survival and reduce long‐term toxicity. This review discusses the evolution of the treatment regimens employed for management of the most common solid tumors, emphasizing the similarities between contemporary and historical regimens. These similarities allow the use of historical patient cohorts to identify the late effects of successful therapy and to evaluate remedial interventions for these adverse effects. Pediatr Blood Cancer 2013; 60: 1083–1094. © 2013 Wiley Periodicals, Inc.
Survival following disease recurrence of primary localized alveolar rhabdomyosarcoma
Authors: Dantonello Tobias M. , Int‐Veen Christoph , Schuck Andreas , Seitz Guido , Leuschner Ivo , Nathrath Michaela , Schlegel Paul‐Gerhardt , Kontny Udo , Behnisch Wolfgang , Veit‐Friedrich Iris , Kube Stefanie , Hallmen Erika , Kazanowska Bernarda , Ladenstein Ruth , Paulussen Michael , Ljungman Gustaf , Bielack Stefan S. , Klingebiel T. , Koscielniak E. ,   on behalf of the Cooperative Weichteilsarkom Studiengruppe (CWS)
Published: February 2013

AbstractBackgroundRecurrences in primary localized alveolar rhabdomyosarcoma (RMA) are common. Post‐relapse survival is poor. We evaluated prognostic factors including relapse treatment in patients with recurrent RMA.MethodsRelapses occurred in 115/235 patients with nonmetastatic RMA treated in four consecutive CWS‐trials after achievement of a complete remission. Sufficient information about post‐relapse treatment and outcome could be obtained in 99 patients and was retrospectively analyzed.ResultsNine of 99 patients received no salvage therapy and died after a median of 2 months. The remaining 90 patients received multimodal relapse treatment including mandatory chemotherapy. Recurrences were grossly resected in 39 patients; 57 patients received radiation. At a median follow‐up from relapse of 8 years, 20 patients were alive and disease‐free (5‐year post‐relapse survival [PROS] 21.3 ± 8). All surviving patients apart from a single individual had an isolated, circumscribed recurrence. Sixteen of 20 survivors were treated with adequate local relapse therapy (ALRT, i.e., either complete resection or gross resection + radiation). Survival in the subgroup of 27 individuals with circumscribed recurrences and ALRT was significantly better (PROS 53.7 ± 19) compared with disseminated recurrences and/or tumors treated without ALRT. Absence of primary lymph node involvement, circumscribed relapses, ALRT, and achievement of a second CR were identified as independent favorable risk factors.ConclusionPost‐relapse survival for primary localized RMA is generally poor. However, certain patient groups differed significantly in their likelihood of survival and 50% of patients with circumscribed relapses treated with ALRT survived. These findings may form the basis for an evidence‐based risk‐stratification for recurrent disease including relapse treatment. Pediatr Blood Cancer 2013;60:1267–1273. © 2013 Wiley Periodicals, Inc.
The validity of sequence symmetry analysis (SSA) for adverse drug reaction signal detection
Authors: Wahab Izyan A. , Pratt Nicole L. , Wiese Michael D. , Kalisch Lisa M. , Roughead Elizabeth E. 
Published: February 2013

ABSTRACTPurposeTo determine the validity of sequence symmetry analysis (SSA) method to detect adverse drug reactions from an administrative claims database.MethodsPublished randomised controlled trials (RCTs) of 19 medicines were identified through search databases, product information (PI) or the US Food and Drug Administration Web site. All adverse events (AEs) in the RCTs and the PI for the medicines were extracted. AEs were considered ‘gold standard positive events’ if they were reported as being statistically significant events in adequately powered RCTs. The remaining AEs were considered ‘gold standard negative events’ if the event was not listed as an AE in the PI for that medicine or any other medicine in its class. Indicators of AEs were identified by consensus from two clinical researchers. SSA was run for each medicine–indicator pair using four different time windows: 3, 6, 9 and 12 months.ResultsA total of 120 randomised placebo controlled trials were reviewed for the 19 tested medicines. A total of 165 medicine–indicator pairs (44 positive and 121 negative events) were identified and tested by SSA. At the 12‐month time window, the sensitivity, specificity, positive and negative predictive values of SSA were 61% (95%CI 0.46–0.74), 93% (95%CI 0.87–0.96), 77% (95%CI 0.61–0.88) and 87% (95%CI 0.80–0.92), respectively. Using a 3‐month time window, the SSA had a lower sensitivity (52%).ConclusionsThe SSA technique was found to have moderate sensitivity and high specificity for detecting ADRs. These results suggest that SSA is a potential tool for detecting ADRs using administrative claims data that could complement existing pharmacosurveillance methods. Copyright © 2013 John Wiley & Sons, Ltd.
A system dynamics model of tellurium availability for CdTe PV
Authors: Houari Yassine , Speirs Jamie , Candelise Chiara , Gross Robert 
Published: February 2013

ABSTRACTThe routine availability of key component materials has been highlighted as a potential constraint to both extensive deployment and reduction in production costs of thin‐film photovoltaic (PV) technologies. This paper examines the effect of material availability on the maximum potential growth of thin‐film PV by 2050 using the case of tellurium (Te) in cadmium telluride (CdTe) PV, currently the dominating thin‐film technology with the lowest manufacturing cost. The use of system dynamics (SD) modelling allows for a dynamic treatment of key Te supply features and prospects for reductions in PV demand via material efficiency improvements, as well as greater transparency and a better understanding of future recycling potential. The model's projections for maximum Te‐constrained CdTe PV growth by 2050 are shown to be higher than a number of previous studies using static assumptions—suggesting that a dynamic treatment of the resource constraints for CdTe inherently improves the outlook for future deployment of this technology. In addition, the sensitivity analysis highlights certain complex correlations between the maximum potential CdTe growth by 2050 and the rated lifetime of PV modules as well as the reported size of global Te resources. The highest observed sensitivities are to the recovery rate of Te from copper anode slimes, the active layer thickness, the module efficiency and the utilisation rate of Te during manufacturing, all of which are highlighted as topics for further research. Copyright © 2013 John Wiley & Sons, Ltd.
Controlled radical polymerization of styrene‐based models of the active site of the [FeFe]‐hydrogenase
Authors: Heine Daniel , Pietsch Christian , Schubert Ulrich S. , Weigand Wolfgang 
Published: February 2013

AbstractWithin this study, we report on the first controlled radical polymerization of styrene‐based models of the active site of the [FeFe]‐hydrogenase. Three different model complexes based on styrene were prepared including propanedithiolato‐bridged, 2‐azapropanedithiolato‐bridged, and bifunctional styrene iron complex. These model complexes were copolymerized with styrene using free radical and the reversible addition‐fragmentation chain transfer polymerization method. The polymerization behavior of the hydrogenase models is discussed and analyzed in detail. It could be shown that the model complex can be incorporated into copolymers. The obtained copolymers exhibit narrow molar mass distributions. The presence of the [FeFe]‐hydrogenase models were proven by atomic absorption spectrometry, NMR and IR spectroscopy as well as cyclovoltammetric measurements. It could be shown that the [FeFe]‐hydrogenase mimic copolymers, as well as the monomeric originating complexes exhibit electrocatalytic proton reduction at a low potential of –2.2 V. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
A facile strategy for synthesis of α,α′‐heterobifunctionalized poly (ε‐caprolactones) and poly (methyl methacrylate)s containing “clickable” aldehyde and allyloxy functional groups using initiator approach
Authors: Sane Prakash S. , Tawade Bhausaheb V. , Parmar Indravadan , Kumari Savita , Nagane Samadhan , Wadgaonkar Prakash P. 
Published: February 2013

AbstractTwo new initiators, namely, 4‐(4‐(2‐(4‐(allyloxy) phenyl)‐5‐hydroxypentane 2‐yl) phenoxy)benzaldehyde and 4‐(4‐(allyloxy) phenyl)‐4‐(4‐(4‐formylphenoxy) phenyl) pentyl 2‐bromo‐2‐methyl propanoate containing “clickable” hetero‐functionalities namely aldehyde and allyloxy were synthesized starting from commercially available 4,4′‐bis(4‐hydroxyphenyl) pentanoic acid. These initiators were utilized, respectively, for ring opening polymerization of ε‐caprolactone and atom transfer radical polymerization of methyl methacrylate. Well‐defined α‐aldehyde, α′‐allyloxy heterobifunctionalized poly(ε‐caprolactones) (Mn,GPC: 5900–29,000, PDI: 1.26–1.43) and poly(methyl methacrylate)s (Mn,GPC: 5300–28800, PDI: 1.19–1.25) were synthesized. The kinetic study of methyl methacrylate polymerization demonstrated controlled polymerization behavior. The presence of aldehyde and allyloxy functionality on polymers was confirmed by 1H NMR spectroscopy. Aldehyde‐aminooxy and thiol‐ene metal‐free double click strategy was used to demonstrate reactivity of functional groups on polymers. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Second Harmonic Generation in 3‐D Uniform Arrangement of Type I Collagen on Nonlinear Optics Microscopy
Authors: Zhuang Z. F. , Zhu M. F. , Guo Z.Y. , Liu S. H. 
Published: February 2013

SummarySecond harmonic microscopic imaging and spectroscopy technology has become a powerful tool for biomedical studies, especially in fibrosis‐related diseases research. And type I collagen is the major risk factors for fibrotic diseases. In this study, model for three‐dimensional (3‐D) uniform arrangement type I collagen is set up for researching the second harmonic generation (SHG) on nonlinear optics microscopy. Based on this model, we discuss the influence of different length and size collagen in 3‐D arrangement type I collagen. Results can guide us to neatly judge the size, length, and molecules density effect on SHG. For practical application, this theoretical approach can lead us to analyze different severity of collagen diseases. SCANNING 35:12‐16, 2013. © 2012 Wiley Periodicals, Inc.