bluuebunny/crossref_metadata_2025 huggingface dataset:
Wafer-scale transfer-free process of multi-layered graphene grown by chemical vapor deposition
Authors: Ricciardella Filiberto , Vollebregt Sten , Boshuizen Bart , Danzl F J K , Cesar Ilkay , Spinelli Pierpaolo , Sarro Pasqualina Maria
Published: February 2020

Chemical vapour deposition (CVD) has emerged as the dominant technique to combine high quality with large scale production of graphene. The key challenge for CVD graphene remains the transfer of the film from the growth substrate to the target substrate while preserving the quality of the material. Avoiding the transfer process of single or multi-layered graphene (SLG-MLG) has recently garnered much more interest. Here we report an original method to obtain a 4-inch wafer fully covered by MLG without any transfer step from the growth substrate. We prove that the MLG is completely released on the oxidized silicon wafer. A hydrogen peroxide solution is used to etch the molybdenum layer, used as a catalyst for the MLG growth via CVD. X-ray photoelectron spectroscopy proves that the layer of Mo is etched away and no residues of Mo are trapped beneath MLG. Terahertz transmission near-field imaging as well as Raman spectroscopy and atomic force microscopy show the homogeneity of the MLG film on the entire wafer after the Mo layer etch. These results mark a significant step forward for numerous applications of SLG-MLG on wafer scale, ranging from micro/nano-fabrication to solar cells technology.
Witnesses of non-classicality for simulated hybrid quantum systems
Authors: Bhole G , Jones J A , Marletto C , Vedral V
Published: February 2020

The task of testing whether quantum theory applies to all physical systems and all scales requires considering situations where a quantum probe interacts with another system that need not obey quantum theory in full. Important examples include the cases where a quantum mass probes the gravitational field, for which a unique quantum theory of gravity does not yet exist, or a quantum field, such as light, interacts with a macroscopic system, such as a biological molecule, which may or may not obey unitary quantum theory. In this context a class of experiments has recently been proposed, where the non-classicality of a physical system that need not obey quantum theory (the gravitational field) can be tested indirectly by detecting whether or not the system is capable of entangling two quantum probes. Here we illustrate some of the subtleties of the argument, to do with the role of locality of interactions and of non-classicality, and perform proof-of-principle experiments illustrating the logic of the proposals, using a Nuclear Magnetic Resonance quantum computational platform with four qubits.
Risk Perceptions and Safety Cultures in the Handling of Nanomaterials in Academia and Industry
Authors: Kirkegaard Marie Louise , Kines Pete , Jeschke Katharina Christiane , Jensen Keld Alstrup
Published: February 2020

Objectives

Work and research with nanomaterials (NMs) has primarily focused on innovation, toxicity, governance, safety management tools, and public perceptions. The aim of this study was to identify academia and industry occupational safety and health (OSH) managers’ perceptions and handling of NMs, in relation to safety culture.

Methods

Semistructured interviews were carried out with OSH managers at six academic institutions and six industrial companies. The interview statements were coded into five topics regarding NMs: risk comprehension, information gathering, actions, communication, and compliance. The statements were then coded according to a five-step safety culture maturity model reflecting increasing occupational safety maturity from passive, to reactive, active, proactive, and exemplary occupational safety.

Results

The safety culture maturity of the academic institutions were primarily active and proactive, whereas the industry group were primarily active and reactive. None of the statements were rated as exemplary, with the majority reflecting an active safety culture. The topics varied from a passive approach of having no focus on NMs and regarding risks as a part of the job, to applying proactive measures in the design, production, application, and waste management phases. Communication and introduction to OSH issues regarding NMs as well as compliance provided challenges in both academia and industry, given the increasing cultural and linguistic diversity of students/staff and employees. Workplace leaders played a crucial role in establishing a legitimate approach to working safely with NMs, however, the currently available OSH information for NMs were described as insufficient, impractical, and inaccessible. There was an embedded problem in solely relying on safety data sheets, which were often not nanospecific, as this may have led to underprotection.

Conclusions

There is a need for more structured, up-to-date, easily accessible, and user-friendly tools and information regarding toxicity and threshold limit values, relevant OSH promotion information, legislation, and other rules. The study underscores the need for politicians and engineers to collaborate with communication experts and both natural and social scientists in effectively framing information on NMs. Such a collaboration should allow for flexible deployment of multilevel and integrated safety culture initiatives to support sustainable nanotechnology and operational excellence.
Coupled matrix–matrix and coupled tensor–matrix completion methods for predicting drug–target interactions
Authors: Bagherian Maryam , Kim Renaid B , Jiang Cheng , Sartor Maureen A , Derksen Harm , Najarian Kayvan
Published: February 2020

Predicting the interactions between drugs and targets plays an important role in the process of new drug discovery, drug repurposing (also known as drug repositioning). There is a need to develop novel and efficient prediction approaches in order to avoid the costly and laborious process of determining drug–target interactions (DTIs) based on experiments alone. These computational prediction approaches should be capable of identifying the potential DTIs in a timely manner. Matrix factorization methods have been proven to be the most reliable group of methods. Here, we first propose a matrix factorization-based method termed ‘Coupled Matrix–Matrix Completion’ (CMMC). Next, in order to utilize more comprehensive information provided in different databases and incorporate multiple types of scores for drug–drug similarities and target–target relationship, we then extend CMMC to ‘Coupled Tensor–Matrix Completion’ (CTMC) by considering drug–drug and target–target similarity/interaction tensors. Results: Evaluation on two benchmark datasets, DrugBank and TTD, shows that CTMC outperforms the matrix-factorization-based methods: GRMF, $L_{2,1}$-GRMF, NRLMF and NRLMF$\beta $. Based on the evaluation, CMMC and CTMC outperform the above three methods in term of area under the curve, F1 score, sensitivity and specificity in a considerably shorter run time.
Acute interstitial nephritis due to sodium-glucose co-transporter 2 inhibitor empagliflozin
Authors: Ryan Rebecca , Choo Stephanie , Willows Jamie , Walker Julie , Prasad Kolanu , Tez Didem
Published: February 2020

Biopsy-proven acute interstitial nephritis (AIN) secondary to sodium-glucose co-transporter 2 (SGLT2) inhibitors has not been described previously. Here, we report on the management of a patient with severe acute kidney injury that developed 6 weeks after starting empagliflozin. The cause was confirmed as AIN on renal biopsy. Our patient recovered, without the need for dialysis, with discontinuation of empagliflozin and corticosteroid treatment. This novel clinical observation is likely to occur more frequently as these drugs are increasingly being prescribed, given that recent randomized controlled trials including EMPA-REG (Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes) showed SGLT2 inhibitors can decrease cardiovascular mortality, among other benefits, in high-risk diabetic populations.
RA-map: building a state-of-the-art interactive knowledge base for rheumatoid arthritis
Authors: Singh Vidisha , Kalliolias George D , Ostaszewski Marek , Veyssiere Maëva , Pilalis Eleftherios , Gawron Piotr , Mazein Alexander , Bonnet Eric , Petit-Teixeira Elisabeth , Niarakis Anna
Published: February 2020

Rheumatoid arthritis (RA) is a progressive, inflammatory autoimmune disease of unknown aetiology. The complex mechanism of aetiopathogenesis, progress and chronicity of the disease involves genetic, epigenetic and environmental factors. To understand the molecular mechanisms underlying disease phenotypes, one has to place implicated factors in their functional context. However, integration and organization of such data in a systematic manner remains a challenging task. Molecular maps are widely used in biology to provide a useful and intuitive way of depicting a variety of biological processes and disease mechanisms. Recent large-scale collaborative efforts such as the Disease Maps Project demonstrate the utility of such maps as versatile tools to organize and formalize disease-specific knowledge in a comprehensive way, both human and machine-readable. We present a systematic effort to construct a fully annotated, expert validated, state-of-the-art knowledge base for RA in the form of a molecular map. The RA map illustrates molecular and signalling pathways implicated in the disease. Signal transduction is depicted from receptors to the nucleus using the Systems Biology Graphical Notation (SBGN) standard representation. High-quality manual curation, use of only human-specific studies and focus on small-scale experiments aim to limit false positives in the map. The state-of-the-art molecular map for RA, using information from 353 peer-reviewed scientific publications, comprises 506 species, 446 reactions and 8 phenotypes. The species in the map are classified to 303 proteins, 61 complexes, 106 genes, 106 RNA entities, 2 ions and 7 simple molecules. The RA map is available online at ramap.elixir-luxembourg.org as an open-access knowledge base allowing for easy navigation and search of molecular pathways implicated in the disease. Furthermore, the RA map can serve as a template for omics data visualization.
Coronary arteritis: a case series
Authors: Kikuchi Shinnosuke , Okada Kozo , Hibi Kiyoshi , Maejima Nobuhiko , Yabu Naoto , Uchida Keiji , Tamura Kouichi , Kimura Kazuo
Published: February 2020

Background

The present article describes two cases of patients with coronary arteritis (CA) whose identification of CA diagnosis (late vs. early) resulted in different clinical courses and outcomes.

Case summary

Case 1 is a 53-year-old woman with multiple coronary risk factors who was admitted with acute coronary syndrome (ACS) and significant stenosis in the left main trunk (LMT). Although clues suggested arteritis (LMT lesion without any other stenosis, occlusion of left internal thoracic artery, etc.), the diagnosis of CA (coronary involvement of unclassified arteritis) was delayed and revascularization, including coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI), was performed under uncontrolled inflammatory status. As a result, Case 1 experienced repeated ACS episodes due to graft failure and in-stent restenosis, and repeatedly underwent PCI. Case 2 is a 76-year-old woman with no significant coronary risk factors who was admitted with ACS. This patient was successfully diagnosed with coronary involvement of Takayasu arteritis before revascularization. Coronary artery bypass grafting was performed after stabilizing inflammation with prednisolone, and the patient remains angina-free beyond 1-year post-CABG. In both cases, intravascular imaging clearly identified the localization and degree of inflammation related to CA by demonstrating specific findings (ambiguous typical three-layer structure of arterial wall and extended low-echoic areas within adventitia).

Discussion

Accurate and early diagnosis with meticulous diagnostic and therapeutic strategies appear to be important for favourable clinical outcomes in the medical treatment of patients with coronary involvement of arteritis. Intravascular imaging has the potential to contribute to optimizing clinical management of CA.
A case report of capillary leak syndrome with recurrent pericardial and pleural effusions
Authors: Khan Habib R , Khan Saima , Srikanth Asha , Smith William H T
Published: February 2020

Background

Capillary leak syndrome (CLS) is a rare connective tissue disease, triggered by the leak of serous fluid into the interstitial spaces, characterized by a hallmark of oedema and effusions in confined spaces. The limiting factor in CLS management appears to be its diagnosis rather than treatment, which is usually to contain the disease progression rather than a cure.

Case summary

We report a case of a 51-year-old woman with recurrent life-threatening presentations of pericardial effusions, pleural effusions, and generalized swelling of face and extremities. The only notable past medical history was of Type 1 diabetes. Numerous investigations did not lead to specific disease accounting for pericardial effusions and pleural effusions. Eventually, the diagnosis of CLS was made based on hypovolaemic shock, hypoalbuminaemia, and haemoconcentration without the presence of albuminuria. She was managed with steroids to reduce system inflammation and later with immunoglobulins and tumour necrosis factor to contain the disease process. Since her diagnosis and subsequent appropriate management, she has not had further admissions with cardiac tamponade 16 months of follow-up.

Discussion

The diagnosis of CLS is difficult to make unless there is a high degree of suspicion and until other causes have been ruled out. It remains a challenging condition to manage as the treatment options are limited and patients recurrently present with emergencies until the correct diagnosis is made and the optimal treatment is provided.
Surprising diagnosis in a patient with acute coronary syndrome: a case report of acute streptococcal pharyngitis-associated perimyocarditis
Authors: Chatzantonis Grigorios , Meier Claudia , Bietenbeck Michael , Rueckert Jan , Dorsel Thomas , Yilmaz Ali , Florian Anca
Published: February 2020

Background

Streptococcal pharyngitis is a common infection, with both suppurative and non-suppurative complications. Most importantly, a streptococcal infection can cause heart disease in different pathophysiological pathways. Acute non-rheumatic perimyocarditis appears to be a more frequent pathological entity associated with streptococcal pharyngitis as once thought, which is poorly understood and explored.

Case summary

We present the case of a middle-aged man with acute chest pain, electrocardiogram (ECG) abnormalities, and elevated cardiac enzymes following a recent episode of pharyngitis in which streptococcal-associated perimyocarditis was diagnosed. Cardiovascular magnetic resonance (CMR) imaging established the diagnosis and allowed cardiac disease monitoring after successful antibiotic therapy resulting in complete clinical recovery.

Discussion

Patients presenting with acute chest pain, ECG abnormalities, and cardiac enzyme elevations do not always suffer from an ischaemic heart attack. A thorough investigation comprising a detailed past medical history and non-invasive imaging such as CMR are the cornerstones for unravelling a correct diagnosis and implementing a proper treatment—as was shown in the present clinical case.
Mid-term outcomes of valve-sparing root reimplantation with leaflet repair
Authors: Yokawa Koki , Henmi Soichiro , Nakai Hidekazu , Yamanaka Katsuhiro , Omura Atsushi , Inoue Takeshi , Okita Yutaka , Okada Kenji
Published: February 2020

OBJECTIVES

Valve repair for aortic insufficiency (AI) requires a tailored surgical approach determined by the leaflet and aortic disease. In this study, we used a repair-oriented system for the classification of AI, and we elucidated long-term outcomes of aortic root reimplantation with this classification system.

METHODS

From 1999 to 2018, a total of 197 patients underwent elective reimplantation (mean age: 52.7 ± 17.7 years; 80% male). The aortic valve was tricuspid in 143 patients, bicuspid in 51 patients and quadricuspid in 3 patients. A total of 93 patients had type I AI (aortic dilatation), 57 patients had type II AI (cusp prolapse) and 47 patients had type III AI (restrictive). In total, 104 of the 264 patients (39%) had more than 1 identified mechanism.

RESULTS

In-hospital mortality was 0.5% (1/197). Mid-term follow-up (mean follow-up duration: 5.5 years) revealed a late mortality rate of 4.2% (9/197). Aortic valve reoperation was performed on 16 patients (8.0%). Rates of freedom from aortic valve replacement and freedom from aortic valve-related events at 10 years of follow-up were 87.0 ± 4.0% and 60.6 ± 6.0%, respectively; patients with type Ib AI (98.3 ± 1.7%; 80.7 ± 7.5%) had better outcomes than patients with type III AI (59.6 ± 15.6%; 42.2 ± 13.1%, P = 0.01). In patients with types II and III AI who had bicuspid aortic valves, rates of freedom from aortic valve-related events at 5 years of follow-up were 95.2 ± 4.7% and 71.7 ± 9.1%, respectively (P = 0.03).

CONCLUSIONS

This repair-oriented system for classifying AI could help to predict the durable aortic valve repair techniques. Patient selection according to the classification is particularly important for long-term durability.

Clinical trial registration number

B190050.
The metabolic shift in highly and weakly virulent Dickeya solani strains is more affected by temperature than by mutations in genes encoding global virulence regulators
Authors: Potrykus Marta , Decorosi Francesca , Perkowska Izabela , Viti Carlo , Mengoni Alessio , Hugouvieux-Cotte-Pattat Nicole , Lojkowska Ewa
Published: February 2020

Global warming may shortly increase the risk of disease development on plants. Significant differences in the metabolic activity screened with Phenotype Microarray at 22°C and 28°C were observed between D. solani strains with high and low virulence level. Highly virulent D. solani was characterized by a higher number of metabolized compounds and a faster metabolism and was more tolerant to non-favorable pH and osmolarity. Metabolic phenotyping showed for the first time that the mutation in pecT gene, which encodes a global repressor of virulence, affects several pathways of the basic cell metabolism. PecT mutants had a higher maceration capacity of potato tissue and showed a higher pectinolytic activity than the wild-type strains. On the contrary, mutation in expI gene, which encoded the signaling molecules synthase crucial for quorum sensing, had an insignificant effect on the cell metabolism, although it slightly reduced the potato tissue maceration. The ability to utilize most of the tested compounds was higher at 28°C, while the survival at non-favorable pH and osmolarity was higher at 22°C. These results proved that the temperature of incubation had the most significant impact on the D. solani metabolic profiles.
Hacking the host: exploitation of macrophage polarization by intracellular bacterial pathogens
Authors: Thiriot Joseph D , Martinez-Martinez Yazmin B , Endsley Janice J , Torres Alfredo G
Published: February 2020

Macrophages play an integral role in host defenses against intracellular bacterial pathogens. A remarkable plasticity allows for adaptation to the needs of the host to orchestrate versatile innate immune responses to a variety of microbial threats. Several bacterial pathogens have adapted to macrophage plasticity and modulate the classical (M1) or alternative (M2) activation bias towards a polarization state that increases fitness for intracellular survival. Here, we summarize the current understanding of the host macrophage and intracellular bacterial interface; highlighting the roles of M1/M2 polarization in host defense and the mechanisms employed by several important intracellular pathogens to modulate macrophage polarization to favor persistence or proliferation. Understanding macrophage polarization in the context of disease caused by different bacterial pathogens is important for the identification of targets for therapeutic intervention.
redLips: a comprehensive mechanistic model of the lipid metabolic network of yeast
Authors: Tsouka S , Hatzimanikatis V
Published: February 2020

Over the last decades, yeast has become a key model organism for the study of lipid biochemistry. Because the regulation of lipids has been closely linked to various physiopathologies, the study of these biomolecules could lead to new diagnostics and treatments. Before the field can reach this point, however, sufficient tools for integrating and analyzing the ever-growing availability of lipidomics data will need to be developed. To this end, genome-scale models (GEMs) of metabolic networks are useful tools, though their large size and complexity introduces too much uncertainty in the accuracy of predicted outcomes. Ideally, therefore, a model for studying lipids would contain only the pathways required for the proper analysis of these biomolecules, but would not be an ad hoc reduction. We hereby present a metabolic model that focuses on lipid metabolism constructed through the integration of detailed lipid pathways into an already existing GEM of Saccharomyces cerevisiae. Our model was then systematically reduced around the subsystems defined by these pathways to provide a more manageable model size for complex studies. We show that this model is as consistent and inclusive as other yeast GEMs regarding the focus and detail on the lipid metabolism, and can be used as a scaffold for integrating lipidomics data to improve predictions in studies of lipid-related biological functions.
Transforming even-aged coniferous stands to multi-aged stands: an opportunity to increase tree species diversity?
Authors: Ligot Gauthier , Balandier Philippe , Schmitz Sophie , Claessens Hugues
Published: February 2020

Transforming even-aged coniferous stands into multi-aged ones is attracting growing interest in Europe. However, applying this silvicultural treatment, maintaining a continuous cover and relying on natural regeneration require a deep understanding of the factors driving interspecific competition in the understorey. In particular, knowledge of species-specific response to different light conditions is needed to plan silvicultural treatments and forecast long-term stand composition. In this context, we assessed regeneration (±10–400 cm in height) and light conditions (±1–40 per cent of transmittance) in nine coniferous stands with ranging stand age (±20–120 years) and species composition (Norway spruce, Douglas fir, larch, silver fir and western hemlock) in Belgium. We then modelled interspecific differences in regeneration height growth to forecast the outcome of interspecific competition in different light conditions. Controlling understorey light seems an efficient way to control the interspecific competition, but with some limits, and taking into account sapling size. Maintaining low light conditions (transmittance < 15 per cent) probably reduces interspecific competition as it allows small saplings (height < 100 cm) of most species to grow at a comparable rate. Maintaining higher light conditions might allow a few species to rapidly overgrow the others. Species ranking in height growth changed across the studied light range only between spruce and larch, suggesting that the competition between these two species can be driven through the control of understorey light. On the other hand, controlling canopy openness was found to be insufficient, for example, to promote an advanced regeneration (height ≥ 200 cm) of fir over advanced regeneration of spruce, to promote any species over western hemlock or to promote Douglas fir. Western hemlock, a very shade-tolerant species, was found to grow three times faster than the other species in all the observed conditions (PACL = 5–20 per cent). Douglas fir saplings showed weak growth and marked defoliation, which we hypothetically relate to the recent outbreak of Contarinia pseudotsugae in Western Europe.
Early vs Late Use of Anti-TNFa Therapy in Adult Patients With Crohn Disease: A Systematic Review and Meta-Analysis
Authors: Hamdeh Shadi , Aziz Muhammad , Altayar Osama , Olyaee Mojtaba , Murad Mohammad Hassan , Hanauer Stephen B
Published: February 2020

Objectives

While anti-tumor necrosis factor alpha (anti-TNFa) therapies for Crohn disease (CD) were initially introduced in 1998 for biologic therapies are often introduced after a minimum of 6 years after diagnosis. The benefit of anti-TNFa early in the course of CD is still controversial, with some studies showing better outcomes but others not. To determine whether earlier introduction of anti-TNFa therapy improves efficacy in clinical trials or clinical series, we aimed to perform a meta-analysis comparing early vs late anti-TNFa use in the management of CD.

Methods

A comprehensive search of MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus was conducted from each database’s inception to November 3, 2019. We included comparative studies of early vs late use of anti-TNFa therapy in adult patients with CD.

Results

Eleven studies were included in the analysis, with a total of 2501 patients. Meta-analysis demonstrated that the early use of anti-TNFa was associated with a statistically significant decrease in the need for surgery (relative risk [RR] = 0.43; 95% confidence interval [CI], 0.26–0.69; I2 = 68%) and disease progression (RR = 0.51; 95% CI, 0.35–0.75; I2 = 61%). Early use also showed an increase in early remission (RR = 1.94; 95% CI, 1.54–2.46; I2 = 0%) and clinical response. There was no statistically significant difference in achieving late remission (RR = 1.39; 95% CI, 0.94–2.05; I2 = 65%) or mucosal healing (RR = 1.10; 95% CI, 0.63–1.91; I2 = 0%).

Conclusion

This systematic review suggests that using anti-TNFa earlier in the treatment of CD (within 3 years) may improve clinical outcomes compared to late administration in terms of achieving early clinical remission, clinical response, disease progression, and the need for surgery.
A Framework to Monitor Changes in Transmission and Epidemiology of Emerging Pathogens: Lessons From Nipah Virus
Authors: Nikolay Birgit , Salje Henrik , Khan A K M Dawlat , Sazzad Hossain M S , Satter Syed M , Rahman Mahmudur , Doan Stephanie , Knust Barbara , Flora Meerjady Sabrina , Luby Stephen P , Cauchemez Simon , Gurley Emily S
Published: February 2020

It is of uttermost importance that the global health community develops the surveillance capability to effectively monitor emerging zoonotic pathogens that constitute a major and evolving threat for human health. In this study, we propose a comprehensive framework to measure changes in (1) spillover risk, (2) interhuman transmission, and (3) morbidity/mortality associated with infections based on 6 epidemiological key indicators derived from routine surveillance. We demonstrate the indicators’ value for the retrospective or real-time assessment of changes in transmission and epidemiological characteristics using data collected through a long-standing, systematic, hospital-based surveillance system for Nipah virus in Bangladesh. We show that although interhuman transmission and morbidity/mortality indicators were stable, the number and geographic extent of spillovers varied significantly over time. This combination of systematic surveillance and active tracking of transmission and epidemiological indicators should be applied to other high-risk emerging pathogens to prevent public health emergencies.
Mind the CISOs
Authors: Fish Ian
Published: February 2020

As is the case each quarter, the ITNOW commissioning editor informed me of the genera theme of the issue - for Spring 2020, it was staying well - specifically promoting better mental health in the workplace, writes Ian Fish, Chair of the Information Security Specialist Group.
Passwords a Lesson in Cyber Security Failure?
Authors: Furnell Steven
Published: February 2020

Passwords are dead, writes Steven Furnell FBCS of the Centre for Security, Communications and Network Research at the University of Plymouth. Numerous people have said so (just search for the phrase to see for yourself).
Cyber Security Predicting the Future
Authors: Barber Craig
Published: February 2020

Craig Barber MBCS M.Inst.ISP CISSP tells ITNOW why strategic planning in cyber security is a little more challenging than you’d first think. But, get it right and you'll stand a better chance of surviving an attack.
The SOC is Dead, Long Live the SOC!
Authors: Smith Matthew
Published: February 2020

The traditional tiered security operation centre approach is flawed, writes Matthew Smith, Global Head of Cyber Security, St. James's Palace - simply because we are human. We must leverage the benefits of machine learning, user behaviour analytics and security automation to deliver effective detection and response in 2020 and beyond.
Process Improvement and the Welsh
Authors: Baxendale Gareth
Published: February 2020

What do the Welsh and process improvement have in common? Gareth Baxendale FBCS CITP FEDIPLeadPract, Head of Technology at the National Institute for Health Research, explains the surprising connection.
5 Rules for Efficient Workshop Facilitation
Authors: Drinkwater Rachel
Published: February 2020

A well-run workshop is a great way to engage a wide variety of stakeholders and can be an excellent platform for exploring ideas, engaging others and eliciting requirements, writes Rachel Drinkwater.
Collaborative Study of Three Methods for Determination of Aflatoxin in Peanuts and Peanut Products
Authors: Waltking A E
Published: February 2020

A collaborative study directly comparing the proposed BF method with the two AOAC official first action methods for aflatoxin in peanut products (commonly designated as the CB and t he Celite methods) was carried out on both naturally contaminated ground peanuts and specially prepared peanut butters, as well as commercial peanut butter and peanut meal to which known amounts of the anatoxins were added. Included in the study were: comparisons of a proposed variation in the CB method; a study of silica gels used for the cleanup step of the CB method; comparison of the visual and instrumental evaluation of the TLC plates; and a spectrophotometric procedure for calibration of the standards. Statistical evaluation of t h e results indicated that no advantage was obtainable through the proposed revision in the CB method nor in the use of a common silica gel lot for t h e cleanup column. The standard calibration method was shown to be both accurate and precise and instrumental evaluations of the TLC plates were shown to be more precise than visual determinations. In addition to being faster and more convenient and requiring less reagents,the BF method was equal to the official methods with respect to between-and withinlaboratory precision and accuracy.
Note on Improved Method for Determination of Vitamins D2 and D3 in Pharmaceuticals by Gas Chromatography
Authors: Erdody P , Murray T K
Published: February 2020

Micro columns of silicic acid are substituted for TLC in the GLC determination of vitamins D2 and D3 in pharmaceuticals. By using the micro columns, a more diverse range of pharmaceutical preparations can be analyzed.
Titrimetric Determination of Dithiodiglycolic Acid in Cold Permanent Wave Solutions
Authors: Bauza Milda J , Nelson J W
Published: February 2020

Dithiodiglycolic acid (DTDGA) is determined in cold permanent wave solutions containing thioglycolic acid (TGA) by a procedure based on reduction of DTDGA to TGA and titration with standard iodine solution. The increase in titer between the reduced and unreduced sample represents DTDGA. Five collaborators analyzed each of two commercial products and four synthetic mixtures for TGA and DTDGA content. Results of the study show an average recovery of 101% for the total acids (DTDGA + TGA). Standard deviation is 2.8% for DTDGA and 1.2% for the total acids. It is recommended that the method be adopted as official first action.
Molar Absorptivity Values for Aflatoxins and Justification for Their Use as Criteria of Purity of Analytical Standards
Authors: Rodricks J V , Stoloff L , Pons W A , Robertson J A , Goldblatt L A
Published: February 2020

Measurements of molar absorptivities in methanol were carried out by two laboratories on samples of anatoxins Bi and Gi prepared and purified independently in four laboratories and on samples of aflatoxins B2 and G2 prepared and purified independently in three laboratories. Molar absorptivities of pure aflatoxins Bi, B2, G1, and G2 in benzene-acetonitrile (98 + 2) were determined at two laboratories. With the exception of aflatoxin G2, no significant difference between aflatoxin samples could be demonstrated. Molar absorptivity values and absorbance ratios for each aflatoxin, based on these data, are given. Statistical 95% confidence limits were established for a single determination of molar absorptivity. A statistical study was made of the components of variance which contribute to the accuracy of the determination of molar absorptivity. A comparison of the fluorescence intensities of spots of various aflatoxin preparations, developed on silica gel-coated thin layer plates, with the amount of aflatoxin in each spotting solution as determined by absorbance measurements, demonstrated the validity of using absorbance and fluorescence comparison measurements for aflatoxin quantitation.
Determination of Ethylene Oxide and Ethylene Chlorohydrin in Plastic and Rubber Surgical Equipment Sterilized with Ethylene Oxide
Authors: Brown Daniel J
Published: February 2020

A method is presented for the determination of ethylene chlorohydrin and ethylene oxide residues in plastic and rubber surgical equipment. Samples are extracted with p-xylene and the desired constituents are isolated by column chromatography. Ethylene oxide is converted to ethylene chlorohydrin on a Celite column. Sweep co-distillation is then employed for further purification, if necessary, before gas-liquid chromatographic analysis. The lower detection limit is approximately 25 ng. Recoveries of 3.5’50 ppm chlorohydrin from 20’35 g samples range from 64 to 100%, depending on the absorbing capacity of the material being analyzed and the condition of the adsorbent.
Extraction and Gas Chromatographic Determination of N-Nitrosodimethylamine in Smoked Fish: Application to Smoked Nitrite-Treated Chub
Authors: Howard John W , Fazio Thomas , Watts James O
Published: February 2020

N-Nitrosodimethylamine can be determined in smoked nitrite-treated chub fish as follows: The fish sample is digested in methanolic potassium hydroxide; the nitrosamine is distilled from alkaline solution, further isolated by extraction and column chromatographic techniques, and determined by GLC with a modified thermionic detector. Recoveries of N-nitrosodimethylamine added at levels of 10 ppb ranged from 70 to 86%. The application of the procedure to the analysis of 5 experimental lots of smoked nitrite-treated chubs indicates that N-nitrosodimethylamine is not produced in the flesh under the conditions of the processing treatment used.
Stability of Individual Aflatoxin B1, B2, G1, and G2 Standards in Benzene and Chloroform Solutions
Authors: Robertson J A , Pons W A , Goldblatt L A
Published: February 2020

Aflatoxin B1, B2, G1, and G2 primary standards were stored in benzene and chloroform solutions for 1 year at 28 and –18°C. Storage at either temperature produced only minor changes in molar absorptivity; the decreases ranged from 0.5 to 2.9% and averaged 1.9% at 28°C and ranged from 0.3 to 1.4% and averaged 1.0% at –18°C. Solution fluorescence KQ showed a greater decrease; it ranged from 8 to 22% and averaged 15% at 28°C and ranged from 7 to 19% and averaged 14% at –18°C. Thin layer chromatography of standards stored 1 year showed a single spot for each aflatoxin and the absence of any other fluorescent derivatives.
GLC Determination of Ethopabate in Chicken Tissues by Derivative Formation
Authors: Handy P R , Holzer F J
Published: February 2020

The published method for the determination of ethopabate residues in chicken tissues has been improved by formation of the 2,4- dinitrophenyl derivative of m-phenetidine, which is produced by hydrolysis of ethopabate. The derivative is suitable for gas-liquid chromatography, using an electron affinity detector, and allows a simpler cleanup procedure. The sensitivity of the method is about 0.05 ppm; average recoveries at 0.5 ppm range between 66 and 97% for all tissues.
Nalidixic Acid in Chicken Tissue
Authors: Browning Robert S , Pratt Edward L
Published: February 2020

Nalidixic acid in chicken muscle and liver homogenates can be estimated by spectrophotofluorimetric measurement. The method, effective for determining nalidixic acid in tissue at levels of 100 ppb, involves extraction, cleanup, and measurement of fluorescence of the isolated drug in 60% H2SO4. In a collaborative study the average recovery was 93% of actual values and the overall estimated standard deviation was 26 ppb. The method is recommended for adoption as official first action.
Specific GLC Method for Determining Residues of Carbaryl by Electron Capture Detection after Derivative Formation
Authors: Butler Lillian I , Mcdonough Leslie M
Published: February 2020

Residues of carbaryl were determined by a specific procedure based on the preparation of two derivatives. Samples of bees, bee bread, bee pollen, and cows’ milk were extracted with chloroform and cleaned up by acetonitrile petroleum ether partitioning and then by liquid chromatography. Subsequently the residues were hydrolyzed to 1-naphthol, part of which was trichloroacetylated and part of which was brominated and acetylated. Both derivatives were then determined by electron capture gas chromatography on the same column and at the same temperature . This procedure required only slightly more time than analysis by preparation of a single derivative. Recoveries from samples fortified at levels of 0.005–16.0 p pm ranged from 70 to 112%.
Thin Layer Chromatographic Separation and Chromogenic Detection of Diazinon and Some of Its Known or Suspected Metabolites and/or Degradation Products
Authors: Siewierski Marie , Helrich Kenneth
Published: February 2020

Diazinon and 5 of its known or suspected transformation products were chromatographed on thin layer sheets and thin layer silica gel plates, using a variety of solvents. Ten chromogenic sprays with sensitivity ranges from 0.05 to 1 μg were used to identify the migrated compounds on the thin layer chromatogram. Two-dimensional TLC separated all the compounds in a single procedure. Several crops fortified at levels of 0.5 to 2.0 ppm were successfully analyzed for these compounds.
Collaborative Study of Two New Methods for the Determination of Phosphorus in Fruits and Fruit Products
Authors: Estrin Ben , Boland Frederick E
Published: February 2020

A collaborative study was conducted to compare a spectrophotometric molybdovanadate method and the official gravimetric quinoline molybdate fertilizer method 2.025(b), slightly modified, with the official volumetric method 20.032. Six collaborating laboratories analyzed dilute acid solutions of the ash of 5 different kinds of fruit products and an aqueous solution containing only KH2PO4 by each of the 3 methods. Satisfactory agreement between laboratories and good agreement between methods were obtained. From the results of this collaborative study it appears that the quinoline molybdate and the molybdovanadate methods are more accurate and precise than the official volumetric method. It is recommended that both the spectrophotometric molybdovanadate method and the gravimetric quinoline molybdate method for the determination of phosphorus in fruits and fruit products be adopted as official first action.
Note on Paper Chromatographic Detection of Adulteration in Dark Colored Fruit Juices
Authors: Fitelson J
Published: February 2020

A second collaborative study was carried out on the official first action method for dark colored fruit juices. The method is based mainly on differences in the anthocyanin patterns of adulterated fruit juices when compared with authentic samples. Natural colors used for such adulteration show more complex patterns than those of the dark juices, so that such addition can usually be detected. Anthocyanidin patterns yield much less information than the anthocyanin patterns. Eleven collaborators correctly detected adulteration in a blackberry juice with added invert sugar and elderberry juice, and 10 of them correctly found adulteration in a raspberry juice with added apple juice and grape skin extract. The method is recommended for adoption as official final action.
Note on Gas Chromatographic Determination of Antihistamines Employing a Dual Column Direct Injection System
Authors: Reiss Thomas J
Published: February 2020

A GLC method is presented for the rapid direct analysis of antihistamines in pharmaceuticals in which the common interfering components are separated by gas chromatography. In previous papers the interferences are first separated by extraction before injection on the column. A dual column system makes it possible to separate each of the antihista mine peaks from each of the 7 most common accompanying component peaks. A simple 1-step extraction procedure is given for the separation of flavoring materials in sirups. Since only 1 or 2 antihistamines are present in any given sample, peak overlapping does not usually present a problem. Deviations from linearity on each column tested were minimal.
Collaborative Study of Procedure for Determining Commercial Sterility of Low-Acid Canned Foods
Authors: Denny C B
Published: February 2020

Nine food laboratories each examined 8 samples of canned salmon (6 sterile; 2 inoculated) in 7 different bacteriological media. Only 3 of the 9 laboratories were 100% correct in all of the tests. Including inoculated cans, a total of 9.1% of the determinations was wrong. A total of 378 culturings of sterile cans was conducted and bacterial contamination occurred in 21 (about 7.1%) of these. An additional collaborative study is indicated.
Detection of Irradiation Treatment in Foods
Authors: Nawar W W , Balboni J J
Published: February 2020

The major radiolytic hydrocarbons resulting from specific cleavage of fatty acids can be used as indicators of irradiation in foods. Experiments with pork ground meat indicate that these compounds are present in samples irradiated at doses as low as 0.1 megarad but absent in unirradiated or heated samples. The major radiolytic hydrocarbons reflect the severity of the irradiation treatment, since their production increases linearly with dose and temperature of irradiation. The presence of moisture or air during the irradiation treatment does not significantly alter the radiolytic pattern
Colorimetric Determination of the Progestational Steroids in Contraceptive Tablets
Authors: Wu John Y P
Published: February 2020

Norethindrone, norethindrone acetate, dimethisterone, medroxyprogesterone acetate, and norethynodrel are determined in oral contraceptive tablets. For the first 4 compounds, a chloroform extract of the tablets is treated directly with isonicotinyl hydrazide reagent to produce a stable color which is measured at 380 nm. The chloroform extract of norethynodrel tablets is isomerized before the reagent is added. An intralaboratory study gave good results, with standard deviations of 0.74 to 1.21%. A collaborative study is recommended.
Culture Media for Disinfectant Testing: Collaborative Study
Authors: Wright Eleanore S
Published: February 2020

Phenol coefficient tests and use-dilution tests were used to evaluate proposed changes in culture media for disinfectant testing. Collaborative results indicate that Anatone, a commercial peptone, is a satisfactory substitute of peptonum siccum or USP peptic digest of animal tissue currently specified in 5.001 (a)(2). In addition, it is also recommended that the 2 synthetic broth preparations studied be included in 5.001(a)(2).
Some Chemical Characteristics and Biological Effects of Photomodified Aflatoxins
Authors: Lillard D A , Lantin R S
Published: February 2020

Changes in UV and infrared absorption spectra were demonstrated upon prolonged exposure of solutions of aflatoxins B1 and G1 to long wave UV light. The treated toxins were less toxic to chick embryos and had lower Rf values on thin layer chromatograms than the parent compounds. These modified compounds may lack either the double bond of the furan ring or the furan ring itself may be removed from the coumarin portion of the molecule. Furthermore, the lactone ring of the aflatoxins is not opened upon exposure to UV light and is not the reason for decreased toxicity.
Sugars in Prune Juice by GLC Separation of Trimethylsilylated Derivatives
Authors: Flynn C , Wendt A S
Published: February 2020

Sugars in prune juice are isolated by lead acetate and converted into trimethylsilylated derivatives; these derivatives are analyzed by GLC. Chromatograms of commercial and laboratory-extracted prune juices are illustrated, including authentic and adulterated samples. Results of a collaborative study demonstrate that this method can be used to detect the presence of added sucrose in prune juice, but additional work is needed to establish the limits of naturally occurring sucrose.
Colorimetric Determination of Nifursol in Feeds
Authors: Zietlow David C , Morrison J L
Published: February 2020

Nifursol is extracted from the feed with DMF. Most of the extracted interferences are removed from the DMF solution by chromatographing the sample through an alumina column; the nifursol is then reacted with phenylhydrazine to form the 5-nitrofurfural phenylhydrazone which is extracted into toluene and determined spectrophotometrically at 555 nm immediately after the addition of Hyamine-OH. Two laboratory feeds containing 0.0025 and 0.0075% nifursol gave average recoveries of 104 and 97%, with coefficients of variation of 5.3 and 3.8%, respectively.
Colorimetric Analysis of Norethindrone, Norethindrone Acetate, and Norgestrel in Oral Contraceptives
Authors: Smith Robert V , Hassall Thomas H , Liu Shuing Carol
Published: February 2020

A colorimetric method, based on reaction with blue tetrazolium, has been devised for the analysis of norethindrone, norethindrone acetate, and norgestrel. The technique is selective for these progestins, showing no interference from the estrogens ethinyl estradiol and mestranol, commonly found in oral contraceptives. The developed procedures have been successfully applied to the determination of progestins in anovulatory tablets.
Automation of Methods for Meat and Meat Products. II. Determination of Phosphorus
Authors: Mcneal Jon E , Karasz Albert , George Elmer
Published: February 2020

An automated method for the analysis of phosphorus in meat, to be used simultaneously with the automated nitrogen determination described in Part I, was studied. This method included the proper connection to the nitrogen manifold, construction of a phosphate manifold, and the preparation of standards to give results comparable to those obtained by the AOAC gravimetric quinoline molybdate method. The method was found to be applicable for meats and meat products containing total phosphorus in the range of 0.05 to 0.4%.
Note on the Preparation of Dehydrated Tomato Powder for the Howard Mold Count
Authors: Parran Hamilton M , Eisenberg William V
Published: February 2020

A study has been initiated to compare 2 methods for the preparation of dehydrated tomato powder for mold count: a hand-mixing procedure and a high-speed blender. The latter method provides for a specified preparation of tomato juice solids of 5.5%. Improved features of this method are that it provides a well dispersed preparation for counting and a more stable suspension. It is recommended that this procedure be studied collaboratively.