Assessing Cellulose Micro/Nanofibre Morphology Using a High Throughput Fibre Analysis Device to Predict Nanopaper Performance

Characterising cellulose nanofibre (CNF) morphology has been identified as a grand challenge for the nanocellulose research field. Direct techniques for CNF morphology characterisation exhibit various difficulties related to the material network structure and equipment cost, while indirect techniques that investigate fibre-light interaction, fibre-solvent interaction, fibre-fibre interaction, or specific fibre surface area involve relatively facile methods but may be more unreliable. Nanopaper mechanical testing is a prevalent metric for assessing fibre-fibre interaction, but is an off-line, time-consuming, and destructive methodology. In this study, an optical fibre morphology analyser (MorFi, TechPap) was employed as an on-line, high throughput, fast turnaround tool to assess micro/nanofibre pulp morphology and predict the properties of nanopaper material. Correlation analysis identified fibre content and fibre kink properties as most correlated with nanopaper strength and toughness, while fibre width and coarseness were most inversely correlated with nanopaper performance. Principal component analysis (PCA) was employed to visualise interdependent morphological and mechanical data. Subsequently, two data driven statistical models - multiple linear regression (MLR) and machine learning based support vector regression (SVR) - were established to predict nanopaper properties from fibre morphology data, with SVR generating a more accurate prediction across all nanopaper properties (NRMSE = 0.13-0.33) compared to the MLR model (NRMSE = 0.33-0.51). This study highlights that statistical methods are useful to disentangle and visualise interdependent morphological data from an on-line fibre analysis device, while regression models are also capable of predicting paper mechanical properties from CNF samples even though these devices do not operate at nanoscale resolution.

Excessive new origin firing underlies selective glioma stem cell cytotoxicity induced by replication stress response inhibition

Aims Glioblastoma (GBM) is a treatment refractory cancer of extreme unmet need which exhibits treatment resistance due to a subpopulation of GBM cancer stem cells which have constitutive DNA damage response activation driven by elevated replication stress (RS). RS response inhibition is potently cytotoxic to GSC, however mechanistic understanding will be key to biomarker discovery and successful clinical translation. We investigated response to combined ATR and PARP inhibition (CAiPi) to gain mechanistic insight and inform biomarker development. Method A panel of patient-derived GBM cell lines were cultured as stem enriched (GSCs) or stem depleted (bulk), to characterise response to combined ATR inhibition (VE821 5μM) and PARP inhibition (Olaparib 1μM), by CellTiter-Glo viability assay. Mechanistic investigations included immunofluorescence of 53BP1 nuclear bodies and DNA fibre analysis. Studies into the importance of PARP trapping included another PARPi Veliparib (1μM), and investigations into inhibition of origin firing used the CDK inhibitor Roscovitine. Results Responses to CAiPi in a panel of primary paired GBM GSCs vs differentiated progeny were heterogenous. CAiPi is selectively GSC cytotoxic in a subpopulation of tumours. DNA fibre analysis identified increased new origin firing with PARPi, which was correlated with increased PARP trapping. Inhibition of origin firing by exposure to roscovitine rescued the CAiPi cytotoxic phenotype, suggesting origin firing has an important role in selective GSC cytotoxicity. A population of treatment-sensitive GSCs with increased numbers of 53BP1 nuclear bodies in G1 phase with CAiPi were identified, indicative of under-replication of DNA in S phase. Conclusion Selective GSC cytotoxicity is induced by CAiPi via dysregulation of replication, by both DNA under-replication resulting in DNA lesions, and the novel finding of increased new origin firing in GSC due to PARPi.

Methane production and bromatological characteristics of the different fractions of organic municipal solid waste

In some countries, garden trimmings are not considered part of urban solid wastes. Lignocellulosic substances contribute to heterogeneity, complicating the analysis of the organic fraction of municipal solid waste (OFMSW) and, subsequently, for methane production. Some of the substances contained in OFMSW are readily biodegradable, and others are not. This work analyses OFMSW from Mexico City and the methane production from its separate components. From OFMSW, nine fractions were visually identified and separated. Including bromatological and fibre analysis, the characterisation of OFMSW and its components was made to determine how the different substances influence methane production. Together, branches, dry leaves, fresh garden trimmings, unsorted wastes (mainly garden trimmings), kitchen paper, and waste vegetables represent 56 % of OFMSW in weight. Fruit waste and unsorted organics contribute to 60 % of the total methane production. Except for branches and dry leaves, methane production increases inversely with the content of lignocellulosic compounds. Animal waste, having the highest concentrations of proteins and lipids and the lowest in lignocellulosic substances, is characterised by the highest level of methane production. Fibre-rich fractions in OFMSW contributed with little or no methane production. Higher concentrations of lignocellulosic substances in the fractions resulted in lower methane production rates.

Periodic addition of anaerobic sludge enhanced the lignocellulosic degradation rate during co-composting of oil palm biomass

The main objective of this work was to investigate the effects of the controlled periodic addition of anaerobic sludge during composting to increase amount of microbial DNA, which appears to be correlated to soluble sugar content which may relate to rate of lignocellulosic degradation. In this study, the composting of pressed-shredded oil palm empty fruit bunch with the periodic addition of palm oil mill effluent anaerobic sludge for moisture control in a newly designed in-vessel type composter was carried out. A control experiment was also conducted over the same period but with the periodic addition of water for moisture control instead of the anaerobic sludge. The lignocellulosic composition and the reducing sugar content were determined via fibre analysis and the spectrophotometric method respectively. The bacterial profile throughout the composting process was quantified by using qPCR. The growth of bacteria reached its peak at 48°C and the degradation of lignocellulose was highest during the thermophilic stage. The highest content of reducing sugar coincided with the highest degradation rate of lignocellulose and the highest DNA copy number during the thermophilic stage. Under the controlled experimental condition of increasing the microbial community, the composting was accelerated to 2.07% OM degradation per day compared to the water addition control at 0.60% OM per day.

Yellow Nail Syndrome with Bilateral Pleural Plaques and Diffuse Pleural Thickening: A Mimic of Asbestos Related Disease

Yellow nail syndrome is a rare acquired condition of unknown aetiology associated with distinct nail discolouration/xanthonychia, pulmonary manifestations, and lymphoedema. Pleural plaques and diffuse pleural thickening are typically, although not exclusively, recognised as markers of prior commercial asbestos exposure. The presence of such biomarkers may assist an asbestos personal injury evaluation. A postmortem examination performed on a 72-year-old man with known long-standing yellow nail syndrome identified pleural plaques and diffuse pleural thickening. An evaluation of the occupational history identified no known asbestos exposure. Electron microscopic mineral fibre analysis detected no asbestos fibres. To the best of our knowledge, this is the only case of yellow nail syndrome in which these benign pleural changes are reported ex asbestos. Alternate causes for such pleural pathology were absent. There is merit in physicians and pathologists having an awareness of these new manifestations when considering claimed asbestos related changes during life and at postmortem.

Misleading “New Insights into the Chrysotile Debate”

Although there is no dispute among independent scientists about the carcinogenic and fibrogenic effects of chrysotile, the asbestos industry has been continuously and successfully acting to cast doubts on its harm. Another approach including asbestos insurance entities is to refuse compensation by raising the bar and fight criminal prosecution for asbestos-related diseases by the help of paid scientists. A recent publication on asbestos fibre burden in human lungs fits well in this context. The claim that chrysotile fibres are biopersistent in human lung is not based on the data provided by these authors, and, additionally, exhibits serious inconsistencies and obvious mismeasurements and significant methodological problems. The conclusion of the authors that fibre analysis of workersʼ lungs “is of high significance for differential diagnosis, risk assessment and occupational compensation” is unfounded and reprehensible. Also the available literature, the statements of the WHO, IARC, other decisive independent international organizations, and all our experience provide abundant evidence to the contrary. Note, the method is generally restricted to research only and is not recognized for diagnostic purpose and compensation in any other country. In conclusion, fibre counting in lung tissues should not be used to estimate former exposure to chrysotile comprising c. 94 % of applied asbestos in Germany. The authors claim that the analyses can improve the compensation rates in Germany. However, the opposite has been the case; it significantly worsens the non-justified denial of well-substantiated compensation claims.

Studies on Physical and Mechanical Properties by Soda-AQ Pulping of Napier Grass

Pulp and paper production from wood material as their main resources have a total capacity about more than one million tons per year. Malaysia has a high scale of deforestation based on the main resource for pulp and paper-based industry. Malaysia as its rate is accelerating faster than any other tropical countries in the world. This problem also affects the economic losses of some countries that face deforestation. To overcome this, Napier grass as a substitute material from non-wood material had been choose for pulp and papermaking industry. This study through the full fibre analysis and morphological characterization, pulpability at kappa number via soda-AQ pulping and the characteristic. These conclude that Napier grass had a high percentage of pulp yields; with a low screening rejects; good mechanical properties by TAPPI method. Thus, Napier grass has a potential to be substitute material for becoming waste-wealth product especially for Malaysia’s pulp and papermaking industry.