bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Phosphorus and Potassium in Commercial Inorganic Fertilizers by Inductively Coupled Plasma-Optical Emission Spectrometry: Single-Laboratory Validation
Authors: Bartos James M , Boggs Barton L , Falls J Harold , Siegel Sanford A
Published: June 2014

A two-part single-laboratory validation study was conducted for determination of the P and K content in commercial fertilizer materials by inductively coupled plasma-optical emission spectrometry (ICP- OES). While several methods exist for determination of P and K in fertilizer products, the main focus of this study was on ICP-OES determination, which offers several unique advantages. Fertilizer samples with consensus P and K values from the Magruder and Association of Fertilizer and Phosphate Chemists (AFPC) check sample programs were selected for this study. Validation materials ranging from 4.4 to 52.4% P2O5 (1.7 to 22.7% P) and 3 to 62% K2O (2.5 to 51.5% K) were utilized. Because all P and K compounds contained in fertilizer materials are not "available" for plants to use, this study was conducted in two parts. Part A focused on ammonium citrate–disodium EDTA as the extraction solvent, as it estimates the pool of fertilizer P and K that is considered available to plants. Part B focused on hydrochloric acid as the digestion solvent, as it estimates the total P and K content of the fertilizer product. Selectivity studies indicated that this method can have a high bias for fertilizer products containing sources of phosphite or organic P compared to gravimetric or colorimetric methods that measure just orthophosphate. Provided the analytical challenges outlined in this study are addressed, this method offers the potential for a quick, accurate, and safe alternative for determining the P and K content of commercial inorganic fertilizer materials.
Validation for the Determination of Biuret in Water-Soluble, Urea-Based Commercial Inorganic Fertilizer Materials, Urea Solutions, and Sulfur-Coated Urea Products by Reversed-Phase Liquid Chromatography: Single-Laboratory Validation of an Extension of AOAC Official MethodSM
2003.14
Authors: Hojjatie Michael M , Abrams Dean
Published: June 2014

A single-laboratory validation (SLV) study for the LC determination of biuret in dry and liquid urea-based commercial fertilizers was conducted. A total of 23 samples were used: 11 commercial dry urea products, two urea ammonium nitrate products, eight liquid urea-based commercial fertilizers, and four sulfur-coated urea samples from different sources. In addition, one biuret standard from Aldrich and one sample from the Magruder check sample program were used as validation samples. The proposed method is an extension of AOAC Official MethodSM 2003.14 and is based on dissolution of the test portion in the LC mobile phase and determination by HPLC. The system is linear over a concentration range of 1.00–4.50 mg/L biuret, with a correlation coefficient ≥0.9999. The biuret was well- separated from urea in the commercial urea samples, and from other constituents in the commercial liquid fertilizer with no observed interferences. Recoveries were determined by spiking four of the validation materials with a known amount of biuret standard and measuring the biuret level according to the method. The averaged recovery was 97%. Method precision was determined by quadruplicate analyses of four of the liquid and six of the commercially available dry urea validation materials using three and four replicate analyses. For the liquid fertilizer analyses, the RSD ranged from 7.04 to 13.31%. For the dry urea analyses, the RSDs ranged from 5.68 to 14.34%. Instrument precision was evaluated at the test initiation by using seven injections of five biuret standard solutions. SD varied from 0.27 to 1.02%, with RSDs averaging 1.14%. The LOD was determined to be 0.009% biuret in material, while the LOQ was determined to be 0.031% biuret in material. In addition to the intralaboratory study, interlaboratory studies were performed by two other outside laboratories using this method. Over a concentration range of 0.2 to 0.9% biuret, the average SD was 0.11%, the average RSD was 21.16%, and the average HorRat value was 4.73%. Furthermore, comparative studies for biuret using AOAC Official MethodsSM 960.04 and 976.01 with the proposed LC method were performed. The three methods produced very close results; however, the two AOAC methods generate hazardous wastes and are more tedious. On the basis of accuracy and precision of the results for this SLV study, it is recommended that this method be collaboratively studied for the determination of biuret in dry and liquid urea-based commercial fertilizer materials.
Determination of Ochratoxin A in Cocoa Beans Using Immunoaffinity Column Cleanup with High-Performance Liquid Chromatography
Authors: Roberts Jillian , Chang-Yen Ivan , Bekele Frances , Bekele Isaac , Harrynanan Lisa
Published: June 2014

A method was developed and validated for the determination of ochratoxin A (OTA), a fungal metabolite, in cocoa beans of high fat content. The sample was extracted by blending with a 1% sodium bicarbonate solution (pH 10) followed by ultrasonication, and the sample was defatted by treatment with a flocculant. The defatted sample was purified using immunoaffinity column chromatography, and OTA was detected using HPLC with fluorescence detection. The method was fully optimized, validated, and quality controlled using spike recovery analyses, with recoveries of 89–105% over spiking ranges of 320–2.5 ng/g with CV of analyses generally <10% over 4 consecutive years and an LOQ of 0.66 ng/g in cocoa bean samples. This method overcomes the problems posed by the high fat contents of cocoa and chocolate samples with a high degree of reliability.
Determination of Forchlorfenuron in Fruits by Solid Phase or QuEChERS Extraction and LC-UV or LC/MS/MS
Authors: Negre Michèle , Passarella Iride , Vindrola Daniela , Baglieri Andrea
Published: June 2014

Forchlorfenuron, N-(2-chloro-4-pyridinyl)-N′-phenylurea, is a plant growth regulator used to increase the size of kiwifruit, apples, table grapes, and peaches and to promote increased yields of potatoes, rice, and wheat. This study reports the comparison of the performancesof two extraction methods [Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and SPE] and two analytical methods (LC-UV and a LC/MS/MS) when determining forchlorfenuron in apples, kiwis, and grapes. Both extraction methods gave recoveries of forchlorfenuron from fruits >70%. The QuEChERS method was cheaper, safer, and less time-consuming than the SPE method and can be recommended for routine analysis. The LOQ was 2 and 10 μg/kg for the LC/MS/MS and LC-UV analysis, respectively. The LOD was 1 and 5 μg/kg for the LC/MS/MS and LC-UV analysis, respectively. The sensitivity of the LC-UV analysis was adequate to measure residue levels five times lower than the maximum residue limit (MRL) of the product. The QuEChERS and SPE methods were applied to monitoring the persistence of forchlorfenuron in field-treated kiwis, and it was found that the residual concentration was already much lower than the MRL 7 days after treatment.
Evaluation of a Soil Incubation Method to Characterize Nitrogen Release Patterns of Slow- and Controlled-Release Fertilizers
Authors: Medina L Carolina , Sartain Jerry B , Obreza Thomas A , Hall William L , Thiex Nancy J
Published: June 2014

Several technologies have been proposed to characterize the nutrient release patterns of slow- release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35°C increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (Iowa>California>Pennsylvania>Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results.
The Use of Dispersive Pipet Extraction (DPX) Tips for the Sample Cleanup of Apples, Pears, and Oranges in the Analysis of Formetanate HCl
Authors: Podhorniak Lynda V
Published: June 2014

The U.S. Environmental Protection Agency Analytical Chemistry Laboratory evaluated the effectiveness of dispersive pipet extraction (DPX) tip cleanup and compared the results with the Quick, Easy, Cheap, Effective, Rugged, and Safe dispersive tube cleanup for the sample preparation of three different fruit matrixes analyzed for formetanate HCl (FHCl). Using LC/MS/MS, the target LOD and the LOQ achieved for FHCl with dispersive tubes, 0.1 and 0.3 ng/g, respectively, were similar to the DPX tip sample cleanup. Recoveries at the LOQ ranged from 94 to 109%. A set of 20–40 samples could be prepared in one working day by one chemist.
Dai Nippon Printing Co., Ltd, Medi·Ca AC for Enumeration of Aerobic Bacteria
Authors: Okochi Norihiko , Yamazaki Mamoru , Kiso Shoichi , Kinoshita Mai , Okita Yurie , Kazama Keisuke , Saito Rui
Published: June 2014

A ready-made dry medium method for aerobic count, the Medi·Ca AC method, was compared to the AOAC Official Method 966.23, Microbiological Methods, for seven different heat-processed meat matrixes: cooked roast beef, Chinese barbecued pork (barbecued pork seasoned with honey-based sauce), bacon, cooked ham, frankfurter (made from beef and pork), and boiled and cooked pork sausage. The 95% confidence interval for the mean difference between the two methods at each contamination level for each matrix fell within the range of −0.50 to 0.50, and no statistical difference was observed at all three contamination levels for five matrixes. These results demonstrate that the Medi·Ca AC method is a reasonable alternative to the AOAC 966.23 method for cooked meat products.
Staphylococcal Enterotoxin B-Specific Electrochemiluminescence and Lateral Flow Device Assays Cross-React with Staphylococcal Enterotoxin D
Authors: Tallent Sandra M , Hait Jennifer , Bennett Reginald W
Published: June 2014

Guam school children and faculty members experienced symptoms of vomiting, nausea, abdominal cramps, and diarrhea shortly after eating breakfast prepared by contracted caterers. The first illness was reported within an hour after breakfast, affecting 295 students and two faculty members. Local hospitals treated 130 people, and 61 were admitted for further treatment. Reported symptoms were consistent with staphylococcal food poisoning. Initial food testing using a lateral flow device and electrochemiluminescence method incorrectly implicated staphylococcal enterotoxin B as the causative agent, prompting partial activation of Guam's Emergency Response Center. Traditional ELISAs proved that the food poisoning agent was staphylococcal enterotoxin D. More specific and sensitive assays would have alleviated the issues and confusion that surrounded the reporting and investigation of this outbreak.
Screening Multimycotoxins in Food-Grade Gums by Stable Isotope Dilution and Liquid Chromatography/Tandem Mass Spectrometry
Authors: Zhang Kai , Wong Jon W , Jia Zhengwei , Vaclavikova Marta , Trucksess Mary W , Begley Timothy H
Published: June 2014

Stable isotope dilution with LC/MS/MS was used to determine the following 11 mycotoxins in food grade gums: aflatoxins B1, B2, G1, and G2; deoxynivalenol; fumonisins B1, B2, and B3; ochratoxin A; T-2 toxin; and zearalenone. Samples were fortified with 11 [13C]-uniformly labeled internal standard ([13C]-IS) mycotoxins that corresponded to the 11 target mycotoxins and extracted by acetonitrile–water (4 + 1, v/v), followed by LC/MS/MS analysis. Mycotoxins were quantitated with the fortified [13C]-IS in each sample. The average recoveries of aflatoxins B1, B2, G1, and G2 (1, 5, and 25 μg/kg); deoxynivalenol and fumonisins B1, B2, and B3 (25, 100, and 500 μg/kg); and ochratoxin A, T-2 toxin, and zearalenone (10, 50, and 250 μg/kg) ranged from 84 to 117% with RSDs less than 20%. Method-dependent LOQs were from 0.1 (aflatoxin B1) to 25 μg/kg (fumonisin B3). Among 20 market samples, aflatoxin B1 (< LOQ) was detected in a Guar gum and a Tragacanth gum, and zearalenone (6 ± 0.6 μg/kg) was detected in a Xanthan gum. The detected mycotoxins were further confirmed by comparing their enhanced product ion spectra to those of reference standards. The single laboratory validated stable isotope dilution and LC/MS/MS method provides sufficient selectivity, sensitivity, accuracy, and reproducibility with a simple sample preparation to screen the 11 mycotoxins in gums.
Veriflow® Campylobacter
Authors: Joelsson Adam C , Brown Ashley S , Puri Amrita , Keough Martin P , Pascal Benjamin J , Gaudioso Zara E , Snook Adam E , Leong Louis E , Siciliano Nicholas A
Published: June 2014

Veriflow®Campylobacter is a molecular based assay for the presumptive and qualitative detection of the most common occurring foodborne Campylobacter species: C. jejuni and C. coli. The assay utilizes a PCR detection method coupled with a rapid, visual, flow-based assay that develops in 3 min post PCR amplification and requires only 24 h of non-specialized enrichment for maximum sensitivity. The Veriflow Campylobacter system eliminates the need for microaerobic chambers, gel electrophoresis or fluorophore based detection of target amplification, and does not require complex data analysis. This Performance Tested MethodSM validation study demonstrated the ability of the Veriflow method to detect naturally occurring Campylobacter from chicken carcass rinsates. In the reference comparison study, Chi-square and probability of detection analyses of two unpaired studies indicated that there was no significant difference between the Veriflow Campylobacter method and the U.S. Department of Agriculture (USDA)/Food Safety and Inspection Service (FSIS) reference method. There was no indication of false positive or false negative detection in the reference comparison study, and all 50 C. jejuni and C. coli strains were detected, while 35 nonspecific organisms were undetected in the exclusivity/ inclusivity study. The study results show that Veriflow Campylobacter is a sensitive, selective and robust assay for the detection of C. jejuni and C. coli in chicken carcass rinsates.
Process Improvement for Regulatory Analyses of Custom-Blend Fertilizers
Authors: Wegner Keith A
Published: June 2014

Chemical testing of custom-blend fertilizers is essential to ensure that the products meet the formulation requirements. For purposes of proper crop nutrition and consumer protection, regulatory oversight promotes compliance and particular attention to blending and formulation specifications. Analyses of custom-blend fertilizer products must be performed and reported within a very narrow window in order to be effective. The Colorado Department of Agriculture's Biochemistry Laboratory is an ISO 17025 accredited facility and conducts analyses of custom-blend fertilizer products primarily during the spring planting season. Using the Lean Six Sigma (LSS) process, the Biochemistry Laboratory has reduced turnaround times from as much as 45 days to as little as 3 days. The LSS methodology focuses on waste reduction through identifying: non-value-added steps, unneeded process reviews, optimization of screening and confirmatory analyses, equipment utilization, nonessential reporting requirements, and inefficient personnel deployment. Eliminating these non-value-added activities helped the laboratory significantly shorten turnaround time and reduce costs. Key improvement elements discovered during the LSS process included: focused sample tracking, equipment redundancy, strategic supply stocking, batch size optimization, critical sample paths, elimination of nonessential QC reviews, and more efficient personnel deployment.
Detection of Salmonella species in a Variety of Foods by the DuPont™ BAX® System Real-Time PCR Assay for Salmonella: First Action 2013.02
Authors: Wallace F Morgan , Andaloro Bridget , Fallon Dawn , Corrigan Nisha , Varkey Stephen , DeMarco Daniel , Farnum Andrew , Tadler Monica , Hoelzer Steven , Weller Julie , Davis Eugene , Rohrbeck Jeffrey , Tice George , Bird Patrick , Crowley Erin , Flannery Jonathan , Fisher Kiel , Huffman Travis , Boyle Megan , Benzinger M Joseph , Bedinghaus Paige , Goetz Katie , Judd William , Agin Jim , Goins David ,   Collaborators:, Churchill C , Clark D , Dieckelman B , Donohue T , Elgaali H , Fedio W , Galbraith E , Hahn L , Kondratko D , Kupski B , McCallum K , McWhorter G , Meyer J , Putrow J , Radcliff R , Rodgers D , Scott S , Swift D , Thompson L
Published: June 2014

A multilaboratory study was conducted to evaluate the ability of the DuPont™ BAX® System Real-Time PCR Assay for Salmonella to detect the target species in a variety of foods and environmental surfaces. Internal validation studies were performed by DuPont Nutrition & Health on 24 different sample types to demonstrate the reliability of the test method among a wide variety of sample types. Two of these matrixes—pork and turkey frankfurters and pasteurized, not-from-concentrate orange juice without pulp—were each evaluated in 14 independent laboratories as part of the collaborative study to demonstrate repeatability and reproducibility of the internal laboratory results independent of the end user. Frankfurter samples were evaluated against the U. S. Department of Agriculture, Food Safety and Inspection Service reference method as a paired study, while orange juice samples were evaluated against the U. S. Food and Drug Administration reference method as an unpaired study, using a proprietary media for the test method. Samples tested in this study were artificially inoculated with a Salmonella strain at levels expected to produce low (0.2–2.0 CFU/test portion) or high (5 CFU/test portion) spike levels on the day of analysis. For each matrix, the collaborative study failed to show a statistically significant difference between the candidate method and the reference method using the probability of detection statistical model.
Simultaneous Determination of Arsenic, Cadmium, Calcium, Chromium, Cobalt, Copper, Iron, Lead, Magnesium, Manganese, Molybdenum, Nickel, Selenium, and Zinc in Fertilizers by Microwave Acid Digestion and Inductively Coupled Plasma-Optical Emission Spectrometry Detection: Single-Laboratory
Validation of a Modification and Extension of AOAC 2006.03
Authors: Webb Sharon , Bartos James , Boles Rhonda , Hasty Elaine , Thuotte Ethel , Thiex Nancy J
Published: June 2014

A single-laboratory validation study was conducted for the simultaneous determination of arsenic, cadmium, calcium, cobalt, copper, chromium, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in all major types of commercial fertilizer products by microwave digestion and inductively coupled plasma-optical emission spectroscopy analysis. This validation study proposes an extension and modification of AOAC 2006.03. The extension is the inclusion of calcium, copper, iron, magnesium, manganese, and zinc, and the modification is incorporation of hydrochloric acid in the digestion system. This dual acid digestion utilizes both hydrochloric and nitric acids in a 3 to 9 mL volume ratio/100 mL. In addition to 15 of the 30 original validation materials used in the 2006.03 collaborative study, National Institute of Standards and Technology Standard Reference Material 695 and Magruder 2009-06 were incorporated as accuracy materials. The main benefits of this proposed method are a significant increase in laboratory efficiency when compared to the use of both AOAC Methods 965.09 and 2006.03 to achieve
Successful Kidney Transplant from Methanol-Intoxicated Donors
Authors: Sklienka Peter , Neiser Jan , Ševčík Pavel , Dvořáček Igor , Samlík Jiří , Jonszta Tomáš , Dedek Vladimír , Kubišová Michaela Matyskov , Tomanová Radoslava , Streitová Dana
Published: June 2014

The well-described disparity between the need for and the supply of organs suitable for transplant is growing. Because of this disparity, mortality of patients listed for transplant is increasing. Donors who die of intoxication (including victims of methanol poisoning) represent less than 1% of suitable donors and might be used to increase the supply of organs. They are often not accepted as donors by transplant specialists, because of concerns about patients' outcomes with these grafts. Three cases of fatal methanol intoxication that resulted in transplants of 6 kidneys are evaluated.
Relationship between Fragmented QRS Complex and Left Ventricular Systolic and Diastolic Function in Kidney Transplant Patients
Authors: Ulusoy Şükrü , Ozkan Gulsum , Adar Adem , Bektaş Hüseyin , Kιrιş Abdulkadir , Çelik Şükrü
Published: June 2014

Background

Kidney transplant is a most important replacement therapy. It reduces cardiovascular mortality and morbidity but does not fully correct impairments in cardiac function. Fragmented QRS (fQRS) complex includes various RSR′ patterns with different QRS complex morphologies on electrocardiograms.

Objective

To analyze fQRS frequency and the relationship between fQRS and left ventricular function in kidney transplant patients.

Method

After demographic data on 39 kidney transplant patients were recorded and biochemical parameters were investigated, electrocardiograms were evaluated for the presence of fQRS. Left ventricular ejection fraction, mitral annular plane systolic excursion, peak early diastolic mitral annular velocities, late diastolic mitral annular velocities, and systolic mitral annular velocity were analyzed.

Results

Fragmented QRS was detected in 16 patients. A history of hypertension was associated with the presence of fQRS. Patients with fQRS had significantly lower systolic and peak early diastolic mitral annular velocities, mitral annular plane systolic excursion, and left ventricular ejection fraction than did patients without fQRS ( P = .03, .01, < .001, and .03, respectively).

Conclusion

Detection of fQRS on electrocardiograms may be useful in predicting systolic and diastolic dysfunction of the left ventricle in kidney transplant patients.
Validation of the Persian Version of COOP/WONCA Functional Health Status Charts in Liver Transplant Candidates
Authors: Mahmoudi Hilda , Jafari Peyman , Ghaffaripour Sina
Published: June 2014

Context

Health-related quality of life is a preferred outcome measure for patients with advanced liver disease. The functional health status charts developed by the Dartmouth Primary Care Cooperative Information Project (COOP)/World Organization of National Colleges, Academies and Academic Associations (WONCA) make up a generic instrument for assessing health-related quality of life.

Objective

To translate and validate the Persian version of COOP/WONCA in liver transplant candidates and to assess the correlation of Child Pugh classification and Model of End Stage Liver Disease (MELD) score with quality of life.

Setting

The Shiraz liver transplant center, the most active liver transplant center in the Middle East.

Participants

Consecutive adult outpatients waiting for their first liver transplant who attended follow-up visits in the pretransplant clinic.

Main Outcome Measures

Patients completed COOP/WONCA along with the Short Form (SF)-36. Data on the underlying cause of cirrhosis, Child-Pugh classification, and MELD scores were collected from medical records.

Results

A Persian version of the COOP/WONCA was accepted by liver transplant candidates and showed adequate reliability and validity. Similar domains in COOP/WONCA charts and the SF-36 were highly correlated, indicating that construct validity of the COOP/WONCA in relation to the SF-36 was good (77% of correlations were as expected). Moreover, the exploratory factor analysis could not extract 2 different quality-of-life factors. These findings provide sufficient evidence to conclude that the Persian versions of COOP/WONCA charts and the SF-36 measure the same constructs of health-related quality of life and can be used interchangeably. Four of the 6 COOP/WONCA charts did not allow discrimination between groups of patients according to Child Pugh classification, indicating poor known group validity.
Hispanic/Latino Concerns about Living Kidney Donation: A Focus Group Study
Authors: Gordon Elisa J. , Mullee Jack O. , Ramirez Daney I. , MacLean Jessica , Olivero Maria , Feinglass Joseph , Carney Paula , O'Connor Kate , Caicedo Juan Carlos
Published: June 2014

Context

Given the shortage of kidneys for transplant, living kidney donation (LKD) is increasingly used to expand the organ donor pool. Although Hispanics/Latinos need disproportionately more kidney transplants, they receive a smaller proportion of living donor kidney transplants than other ethnic/racial groups.

Objective

To assess Hispanics' awareness, perceptions, misconceptions, cultural beliefs, and values about and barriers to LKD.

Design

Nine focus groups were conducted with 76 adult Hispanics in Chicago, Illinois, between January and March 2012.

Participants

Focus groups included kidney transplant recipients, living kidney donors, dialysis patients, and the general Hispanic public.

Results

Several themes emerged as perceived barriers to LKD. Many participants identified knowledge deficits about LKD, expressing uncertainty about the differences between LKD and deceased donation, and whether kidney disease simultaneously afflicts both kidneys. Many believed that donors experience dramatically shorter life expectancies, are unable to have children, and are more susceptible to kidney disease after donating. Recipients and donors reported that family members were involved in discussions about the donor's decision to donate, with some family members discouraging donation. Financial barriers cited included fear of becoming unable to work, losing one's job, or being unable to pay household bills while recovering. Participants also identified logistic barriers for undocumented immigrants (eg, the inability to obtain government insurance for transplant candidates and uncertainty about their eligibility to donate). Donors desired information about optimizing self-care to promote their remaining kidney's health. Culturally competent interventions are needed to redress Hispanics' knowledge deficits and misconceptions and reduce LKD disparities among Hispanics.
Single-molecule tracking in live cells reveals distinct target-search strategies of transcription factors in the nucleus
Authors: Izeddin Ignacio , Récamier Vincent , Bosanac Lana , Cissé Ibrahim I , Boudarene Lydia , Dugast-Darzacq Claire , Proux Florence , Bénichou Olivier , Voituriez Raphaël , Bensaude Olivier , Dahan Maxime , Darzacq Xavier
Published: June 2014

Gene regulation relies on transcription factors (TFs) exploring the nucleus searching their targets. So far, most studies have focused on how fast TFs diffuse, underestimating the role of nuclear architecture. We implemented a single-molecule tracking assay to determine TFs dynamics. We found that c-Myc is a global explorer of the nucleus. In contrast, the positive transcription elongation factor P-TEFb is a local explorer that oversamples its environment. Consequently, each c-Myc molecule is equally available for all nuclear sites while P-TEFb reaches its targets in a position-dependent manner. Our observations are consistent with a model in which the exploration geometry of TFs is restrained by their interactions with nuclear structures and not by exclusion. The geometry-controlled kinetics of TFs target-search illustrates the influence of nuclear architecture on gene regulation, and has strong implications on how proteins react in the nucleus and how their function can be regulated in space and time.
Controls on spatial and temporal evolution of prism faulting and relationships to plate boundary slip offshore north‐central Sumatra
Authors: Cook Becky J. , Henstock Timothy J. , McNeill Lisa C. , Bull Jonathan M.
Published: June 2014

Across‐ and along‐strike variations in the morphology and structure of the north‐central Sumatran forearc (~1.5°S to 1°N) are broadly coincident with subducting plate topography and an earthquake segment boundary zone below the Batu Islands. We present a detailed interpretation of multichannel streamer seismic reflection data collected offshore north‐central Sumatra, to better characterize the morphological and structural variations, provide insight into fault development, and relate structure to plate boundary rupture and seismicity patterns. We interpret two relatively continuous, major fault structures that divide the prism into three strike‐parallel belts that can be characterized by the relative fault slip rates along major and minor fault structures. The midslope break fault(s) and upper slope‐bounding fault(s) are major, potentially out‐of‐sequence thrusts accommodating a significant component of the compressional strain. We propose that the upper slope‐bounding fault represents the more mature end‐member of an evolving fault system. Landward vergent structures are associated with a relatively thin sedimentary section near the deformation front in the center of our study area and suggest a potentially weak shallow plate boundary associated with the subducting Wharton Fossil Ridge.
The impact of westerly wind bursts on the diversity and predictability of El Niño events: An ocean energetics perspective
Authors: Hu Shineng , Fedorov Alexey V. , Lengaigne Matthieu , Guilyardi Eric
Published: June 2014

In this study, we apply ocean energetics as a diagnostic tool to investigate the impact of westerly wind bursts (WWBs) on the evolution, diversity, and predictability of El Niño events. Following Fedorov et al. (2014), we add an observed WWB to simulations within a comprehensive coupled model and explore changes in the available potential energy (APE) of the tropical Pacific basin. We find that WWB impacts strongly depend on the ocean initial state and can range from a Central Pacific (CP) to Eastern Pacific (EP) warming, which is closely reflected by the ocean energetics. Consequently, the APE can be used to quantify the diversity of El Niño events within this continuum—higher negative APE values typically correspond to EP events, lower values to CP events. We also find that a superimposed WWB enhances El Niño predictability even before the spring predictability barrier, if one uses the APE as a predictor.
Investigating Dunedin whistlers using volcanic lightning
Authors: Antel Claire , Collier Andrew B. , Lichtenberger János , Rodger Craig J.
Published: June 2014

Whistlers detected at Dunedin, New Zealand are an anomaly: there is little lightning around Dunedin's conjugate point yet whistlers appear in relatively large numbers. These surplus whistlers have consequently inspired investigations into their origins. Dunedin's lightning‐sparse conjugate point lies in the Aleutian Islands, a region populated with active volcanoes. Their presence has allowed us to perform a novel analysis: the correlation of whistlers to volcanic lightning. We report on our investigation, which successfully yielded the first observations of “volcanic whistlers.” It was found that the single July 2008 Mount Okmok eruption had an impressive effect on the number of whistlers at Dunedin. The eruptions at Mount Redoubt in 2009 also caused a sporadic flow of whistlers in Dunedin.
Centennial variations in sunspot number, open solar flux, and streamer belt width: 2. Comparison with the geomagnetic data
Authors: Lockwood M. , Owens M. J. , Barnard L.
Published: June 2014

We investigate the relationship between interdiurnal variation geomagnetic activity indices, IDV and IDV(1d), corrected sunspot number, RC , and the group sunspot number RG . RC uses corrections for both the “Waldmeier discontinuity,” as derived in Paper 1, and the “Wolf discontinuity” revealed by Leussu et al. (2013). We show that the simple correlation of the geomagnetic indices with RCn or RGn masks a considerable solar cycle variation. Using IDV(1d) or IDV to predict or evaluate the sunspot numbers, the errors are almost halved by allowing for the fact that the relationship varies over the solar cycle. The results indicate that differences between RC and RG have a variety of causes and are highly unlikely to be attributable to errors in either RG alone, as has recently been assumed. Because it is not known if RC or RG is a better predictor of open flux emergence before 1874, a simple sunspot number composite is suggested which, like RG , enables modeling of the open solar flux for 1610 onward in Paper 3 but maintains the characteristics of RC .
Probing Charge Recombination Dynamics in Organic Photovoltaic Devices under Open‐Circuit Conditions
Authors: Elliott Lindsay C. C. , Basham James I. , Pernstich Kurt P. , Shrestha Pragya R. , Richter Lee J. , DeLongchamp Dean M. , Gundlach David J.
Published: June 2014

Large perturbation transient photovoltage and impedance spectroscopy measurements are used to gain insights into recombination in organic photovoltaic devices. The combination of these two simple optoelectronic techniques enables characterization of recombination order as well as mobile and trapped charge evolution over a large range of carrier densities. The data show that trapped charge is approximately equal to total charge at low carrier densities in the high efficiency devices measured. Between low and high charge carrier density, the order of recombination is observed to vary from monomolecular to bimolecular to higher order. The new techniques and methods presented can be applied to any type of photovoltage device to gain insight into device operation and limitations.
Carbon: The Ultimate Electrode Choice for Widely Distributed Polymer Solar Cells
Authors: dos Reis Benatto Gisele A. , Roth Bérenger , Madsen Morten V. , Hösel Markus , Søndergaard Roar R. , Jørgensen Mikkel , Krebs Frederik C.
Published: June 2014

As mass‐produced, low‐cost organic electronics enter our everyday lives, so does the waste from them. The challenges associated with end‐of‐life management must be addressed by careful design and carbon‐based electrodes are central to these developments. Here, the reproducible production of vacuum‐, indium tin oxide (ITO)‐, and silver‐free solar cells in a fully packaged form using only roll‐to‐roll processing is reported. Replacing silver with carbon as electrode material significantly lowers the manufacturing cost and makes the organic photovoltaic (OPV) modules environmentally safe while retaining their flexibility, active area efficiency, and stability. The substitution of silver with carbon does not affect the roll‐to‐roll manufacturing of the modules and allows for the same fast printing and coating. The use of carbon as electrode material is one step closer to the wide release of low‐cost plastic solar cells and opens the door to new possible applications where silver recycling is not manageable.
Truncating mutations in LRP4 lead to a prenatal lethal form of Cenani–Lenz syndrome
Authors: Lindy Amanda S. , Bupp Caleb P. , McGee Stephen J. , Steed Erin , Stevenson Roger E. , Basehore Monica J. , Friez Michael J.
Published: June 2014

Cenani–Lenz syndrome (CLS) is an autosomal recessive skeletal dysplasia that results in malformations of the distal limb, renal anomalies, and characteristic facies. In 2010, this condition was found to be caused by mutations in LRP4, a member of the low‐density lipoprotein family of receptors. LRP4 has been shown to antagonize LRP5/LRP6 activation of WNT and β‐catenin signaling. Loss of LRP4 function leads to excessive Wnt and β‐catenin signaling in the limb bud, which causes abnormal limb development. The large majority of patients with CLS reported in the literature have splicing and missense mutations, which result in syndactyly, oligodactyly, and minor renal malformations. More recently, a patient with CLS has been identified with a homozygous nonsense mutation and a more severe presentation of findings typically associated with this condition. Here we present two sibling fetuses with a prenatal lethal presentation of mesomelic limb reductions, oligosyndactyly, genitourinary malformation and compound heterozygosity for two novel truncating mutations in LRP4. These findings lend further support to the CLS genotype‐phenotype correlation presented in recent publications. © 2014 Wiley Periodicals, Inc.
Pontocerebellar hypoplasia
Authors: Rudnik‐Schöneborn Sabine , Barth Peter G. , Zerres Klaus
Published: June 2014

Pontocerebellar hypoplasia (PCH) is a clinically and genetically heterogeneous group of autosomal recessively inherited neurodevelopmental disorders. Following the rapidly increasing number of genes identified in different subtypes, the clinical spectrum has been broadened to completely different neurological phenotypes. In this review we will address the clinical picture, neuroradiological, pathoanatomic, and genetic findings in the currently known PCH subtypes. © 2014 Wiley Periodicals, Inc.
Ein neuer Weg zu Metallaziden
Authors: Müller Thomas G. , Karau Friedrich , Schnick Wolfgang , Kraus Florian
Published: June 2014

Metallazide eignen sich unter anderem für die Synthese von Nitridophosphaten und binären Nitriden. Hier zeigen wir einen neuen präparativen Zugang zu Aziden auf: Verschiedene Hauptgruppen‐, Übergangs‐ und Seltenerdmetalle reagieren mit wasserfreiem Silberazid in flüssigem Ammoniak unter Bildung der entsprechenden Metallazide. So wurden Mn(N3)2, Sn(N3)2 und Eu(N3)2 sowie deren Amminkomplexe zum ersten Mal mit Tieftemperaturmethoden hergestellt. Des Weiteren gelang mit dieser Methode ein einfacherer Zugang zu Zn(N3)2. Einkristalle eines zweikernigen Holmiumazids, [Ho2(μ‐NH2)3(NH3)10](N3)3⋅1.25 NH3, wurden bei Raumtemperatur und dem entsprechenden Ammoniak‐Dampfdruck erhalten. Wir sind zuversichtlich, dass diese Methode zu weiteren Metallaziden und – nach vorsichtiger Zersetzung – zu neuen Nitriden der Hauptgruppen‐, der Übergangs‐ und der Seltenerdmetalle führen wird.
Direct Sensing of 5‐Methylcytosine by Polymerase Chain Reaction
Authors: Aschenbrenner Joos , Drum Matthias , Topal Hüsnü , Wieland Markus , Marx Andreas
Published: June 2014

The epigenetic control of genes by the methylation of cytosine resulting in 5‐methylcytosine (5mC) has fundamental implications for human development and disease. Analysis of alterations in DNA methylation patterns is an emerging tool for cancer diagnostics and prognostics. Here we report that two thermostable DNA polymerases, namely the DNA polymerase KlenTaq derived from Thermus aquaticus and the KOD DNA polymerase from Thermococcus kodakaraensis, are able to extend 3′‐mismatched primer strands more efficiently from 5 mC than from unmethylated C. This feature was advanced by generating a DNA polymerase mutant with further improved 5mC/C discrimination properties and its successful application in a novel methylation‐specific PCR approach directly from untreated human genomic DNA.
A New Route to Metal Azides
Authors: Müller Thomas G. , Karau Friedrich , Schnick Wolfgang , Kraus Florian
Published: June 2014

Beside several other applications, metal azides can be used for the synthesis of nitridophosphates and binary nitrides. Herein we present a novel synthetic access to azides: Several metals, such as main‐group, transition metals, and rare‐earth metals, react with silver azide in liquid ammonia as a solvent giving the corresponding metal azides. In this work Mn(N3)2, Sn(N3)2, and Eu(N3)2, as well as their ammonia complexes were synthesized for the first time through low‐temperature methods. Also a simpler access to Zn(N3)2 was possible. At room temperature and the respective vapor pressure of NH3, it became possible to grow single crystals of the dinuclear holmium azide [Ho2(μ‐NH2)3(NH3)10](N3)3⋅1.25 NH3. We are confident that this new route could lead to novel metal azides as well as nitrides of the main‐group, the transition, and the rare‐earth metals upon careful decomposition.
Effect of the addition of Ce to MnOx/Ti catalyst on reduction of N2O in low‐temperature SCR
Authors: Shang Tong , Hui Shien , Niu Yanqing , Liang Ling , Liu Changchun , Wang Denghui
Published: June 2014

The effect of MnOx/Ti catalyst doped with Ce prepared by sol–gel method at a low temperature on N2O formation during the selective catalytic reduction of NO with NH3 was studied in detail. Results showed that the production of N2O was primarily controlled by two paths: (1) direct reaction of NO and NH3 and (2) oxidation of NH3 with O2. The overoxidation of NH3 was the dominant step in N2O reduction. Addition of Ce to MnOx/Ti catalyst increased the proportion of lattice oxygen on the catalyst surface. Meanwhile, the stability of lattice oxygen, which contributed to the decrease in N2O formation by inhibiting the overoxidation of NH3, on the catalyst surface was the best when the Ce/Ti mole ratio reached 0.1. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Oxygen mass transfer characteristics in an internal‐loop airlift reactor with preset trumpet‐shaped riser
Authors: Pi Kewu , Huang Lei , Li Zhu , Gao Linxia , Gerson Andrea R.
Published: June 2014

A size‐adjustable trumpet‐shaped riser was installed into a conventional airlift reactor to form a modified internal‐loop airlift reactor (ILAR). The volumetric oxygen mass transfer coefficient (kLa) and gas holdup of the ILAR were heavily influenced by the height ratio of riser to static fluid level above the spargers (h/H), the cross‐sectional area ratio of riser to downcomer (Ar/Ad) and the superficial gas velocity in the riser (Ug) when deoxidized distilled water was used as the oxygen absorbent. An oxygen transfer rate of (2.17 ± 0.11) × 10−5 kg m−3 s−1, kLa of (27.88 ± 1.12) × 10−3 s−1 and gas holdup of 0.031 were obtained with the ILAR of Ar/Ad = 1.09 and h/H = 0.73 at Ug = 18 mm s−1. As the well‐constructed preset trumpet‐shaped riser provided ideal conditions for complete circulation and blending of the fluid, enhanced oxygen transfer efficiency was achieved. The gas holdup and kLa were increased by 16.2% and 10.2% at 19 °C, as compared with those of the conventional airlift reactor without this preset riser. The fluid rising velocity in the riser (VR) and falling velocity in the downcomer (VD) may be expressed by power‐law functions of Ug and Ar/Ad, respectively. These metrics indicate that the ILAR has better performance, as compared with a conventional airlift reaction, for oxygen transfer and microorganism culture for chemical engineering, biological fermentation and environmental protection. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Effects of microstructural functional polyaniline layers on SPEEK/HPW proton exchange membranes
Authors: Ren Suzhen , Xu Meiling , Yang Ying , Ma Shaobo , Hao Ce
Published: June 2014

In this study, a method is developed to fabricate sulfonated poly (ether ether ketone)/phosphotungstic acid‐polyaniline (SPEEK/HPW‐PANI) membranes by in situ polymerization of aniline for the purpose of decreasing the weight loss of HPW in the membranes. The synthesis involves the production of a SPEEK/HPW hybrid membrane followed by different layer of PANI coatings on the membrane surface, and subsequent treatment using drying in vacuum procedures. The scanning electronic microscopy images showed that HPW had good compatibility with SPEEK polymers and energy dispersive X‐ray spectroscopy revealed the successfully doping with HPW and polymerization of PANI. The surface of SPEEK/HPW‐PANI becomes more compact than that of SPEEK/HPW and pure SPEEK, which may lead to reduce the water uptake and swelling property. The proton conductivity was found for the SPEEK/HPW‐PANI‐5 composite membrane (91.53 mS/cm at 80°C) higher than that of pure SPEEK membrane (68.72 mS/cm at 80°C). Better thermal stability was determined in both SPEEK/HPW and SPEEK/HPW‐PANI membranes than pristine SPEEK membrane. Therefore, PANI is a good potential coating for organic–inorganic hybrid e.g. SPEEK/HPW membrane materials to improve their hydrothermal stable properties and SPEEK/HPW PANI is a material that shows promise as a proton exchange membranes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41033.
Synthesis of chitosan‐graft‐β‐cyclodextrin for improving the loading and release of doxorubicin in the nanopaticles
Authors: Lu Lu , Shao Xiaohong , Jiao Yanpeng , Zhou Changren
Published: June 2014

Chitosan‐graft‐β‐cyclodextrin (CS‐g‐β‐CD) copolymer was synthesized by conjugating β‐cyclodextrins to chitosan molecules through click chemistry. The copolymer structure was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). CS‐g‐β‐CD/CMC nanoparticles were prepared by a polyelectrolyte complexation process in aqueous solution between CS‐g‐β‐CD copolymer and carboxymethyl chitosan (CMC), which was used to load anticancer drug (Doxorubicin hydrochloride, DOX·HCl) with hydrophobic group. The particle size, surface charge, zeta potential, and morphology of the nanoparticles were characterized with dynamic light scattering. The drug loading efficiency and in vitro release of DOX·HCl of the nanoparticles were measured by ultraviolet spectrophotometer. The results demonstrated that the size, surface charge and drug loading efficiency of the nanoparticles could be modulated by the fabrication conditions. The drug loading efficiency of CS‐g‐β‐CD/CMC nanoparticles was improved from 52.7% to 88.1% because of the presence of β‐CD moieties with hydrophobic cavities, which can form inclusion complexes with the drug molecules. The in vitro release results showed that the CS‐g‐β‐CD/CMC nanoparticles released DOX·HCl in a controlled manner, importantly overcoming the initial burst effect. These nanoparticles possess much potential to be developed as anticancer drug delivery systems, especially those drugs with hydrophobic group. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41034.
Surface modification using self‐assembled layers of amphiphilic cyclodextrins
Authors: Lumholdt Ludmilla , Thorbjørn Terndrup Nielsen , Kim Lambertsen Larsen
Published: June 2014

In this study six amphiphilic cyclodextrin derivatives were prepared by esterification and used to coat five industrial products made from polypropylene, polyethylene, polyvinyl chloride, or polyurethane using a new, patented coating technology. This simple approach, which consists merely of dipping the material to be coated into a suspension of a given cyclodextrin derivative in an ethanol/water solution, was used to functionalize support materials with a coat that is stable in aqueous solutions and which renders the coated materials hydrophilic. The functionalization proved to be controllable in terms of amount of cyclodextrin on the surface and can be implemented in existing production lines without investment in advanced production equipment. It is hypothesized that the cyclodextrins order themselves in structured layers forming channel‐like structures preserving the very large potential for uptake and release of active compounds that is known to cyclodextrins. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41047.