Extraction of homogeneous lignin oligomers by ozonation of Miscanthus giganteus and vine shoots in a pilot scale reactor

Lignin, a complex phenolic polymer crucial for plant structure, is mostly used as fuel but it can be harnessed for environmentally friendly applications. This article explores ozonation as a green method for lignin extraction from lignocellulosic biomass, aiming to uncover the benefits of the extracted lignin. A pilot-scale ozonation reactor was employed to extract lignin from Miscanthus giganteus (a grass variety) and vine shoots (a woody biomass). The study examined the lignin extraction and modification of the fractions and identified the generation of phenolic and organic acids. About 48 % of lignin was successfully extracted from both biomass types. Phenolic monomers were produced, vine shoots yielding fewer monomers than Miscanthus giganteus. Ozonation generated homogeneous lignin oligomers, although their molecular weight decreased during ozonation, with vine shoot oligomers exhibiting greater resistance to ozone. Extracted fractions were stable at 200 °C, despite the low molecular weight, outlining the potential of these phenolic fractions.

WHO informal consultation on revision of guidelines on evaluation of similar biotherapeutic products, virtual meeting, 30 June – 2 July 2021

The WHO informal consultation was held to promote the revision of WHO guidelines on evaluation of similar biotherapeutic products (SBPs) adopted by the Expert Committee on Biological Standardization (ECBS) in 2009. It was agreed in the past consultations that the evaluation principles in the guidelines are still valid, but a review was recommended to provide more clarity and case-by-case flexibility. The opportunity was therefore taken to review the experience and identify areas where the current guidance could be more permissive without compromising its basic principles, and where additional explanation could be provided regarding the possibility of reducing the amount of data needed for regulatory approval. The meeting participants applauded the leading role taken by the WHO in providing a much-needed streamlined approach for development and evaluation of SBPs which will provide efficient and cost-effective product development and increase patient access to treatments. It was recognized that the principles as currently described in the draft WHO guidelines are based on sound science and experience gained over the last fifteen years of biosimilar approvals. However, since these guidelines when finalised will constitute the global standard for biosimilar evaluation and assist national regulatory authorities in establishing revised guidance and regulatory practice in this complex area, it was felt that further revision and clarity on certain perspectives in specific areas was necessary to dispel uncertainties arising in the current revised version. This report describes the principles in the draft guidelines, including topics discussed and consensus reached.

•

WHO guidelines serve as a basis for the development of national regulatory framework for biosimilars.

•

Revision of guidelines is to provide more flexibility and clarification on data required for regulatory approval.

•

Revised guidelines would contribute to improving consistency on regulatory decision and patient access to treatments.

[Acute fever due to rats]

The bite of a rat can transmit diverse micro-organisms; however, the development of health measures and the improved conditions of habitability of homes have meant that the infectious diseases transmitted by the aggressions of these animals are infrequent in industrialised countries. In occasional circumstances this type of aggression can still take place, especially in depressed areas on the periphery of big cities and in uninhabited premises, this being a possibility that it is advisable to bear in mind. The case is presented of fever due to a rat bite in a patient who was attacked while cleaning an industrial premise. The evolution of the clinical picture was typical, with Streptobacillus moniliformis isolated as the causal agent, and the picture was controlled with doxicycline without complications arising.

ATR-FTIR sensor development for continuous on-line monitoring of chlorinated aliphatic hydrocarbons in a fixed-bed bioreactor

This article describes the continuous on-line monitoring of a dechlorination process by a novel attenuated total reflection-Fourier transform infrared (ATR-FTIR) sensor. This optical sensor was developed to measure noninvasively part-per-million (ppm) concentrations of trichloroethylene (TCE), tetrachloroethylene (PCE), and carbon tetrachloride (CT) in the aqueous effluent of a fixed-bed dechlorinating bioreactor, without any prior sample preparation. The sensor was based on an ATR internal reflection element (IRE) coated with an extracting hydrophobic polymer, which prevented water molecules from interacting with the infrared (IR) radiation. The selective diffusion of chlorinated compound molecules from aqueous solution into the polymer made possible their detection by the IR beam. With the exclusion of water the detection limits were lowered, and measurements in the low ppm level became possible. The best extracting polymer was polyisobutylene (PIB) in the form of a 5.8-microm thick film, which afforded a detection limit of 2, 3, and 2. 5 mg/L (ppm) for TCE, PCE, and CT, respectively. Values of the enrichment factors between the polymer coating and the water matrix of these chloro-organics were determined experimentally and were compared individually with predictions obtained from the slopes of absorbance/concentration curves for the three analytes. Before coupling the ATR-FTIR sensor to the dechlorinating bioreactor, preliminary spectra of the chlorinated compounds were acquired on a laboratory scale configuration in stop-flow and flow-through closed-loop modes. In this way, it was possible to study the behavior and direct response of the optical sensor to any arbitrary concentration change of the analytes. Subsequently, the bioreactor was monitored with the infrared sensor coupled permanently to it. The sensor tracked the progression of the analytes' spectra over time without perturbing the dechlorinating process. To calibrate the ATR-FTIR sensor, a total of 13 standard mixtures of TCE, PCE and CT at concentrations ranging from 0 to 60 ppm were selected according to a closed symmetrical experimental design derived from a 3(2) full-factorial design. The above range of concentrations chosen for calibration reflected typical values during normal bioreactor operation. Several partial least squares (PLS) calibration models were generated to resolve overlapping absorption bands. The standard error of prediction (SEP) ranged between 0.6 and 1 ppm, with a relative standard error of prediction (RSEP) between 3 and 6% for the three analytes. The accuracy of this ATR-FTIR sensor was checked against gas chromatography (GC) measurements of the chlorocompounds in the bioreactor effluents. The results demonstrate the efficiency of this new sensor for routine continuous on-line monitoring of the dechlorinating bioreactor. This strategy is promising for bioprocess control and optimization.

[Sweet's syndrome. Presentation of six cases and review of the literature]

The acute febrile neutrophilic dermatosis or Sweet syndrome, initially described in 1964 by Robert Sweet (1). It is characterized fever, neutrophilic leucocytosis, abrupt appearance of erythematous, painful, cutaneous plaquets and dense dermal infiltrate consisting of mature neutrophils without vasculitis sings. Malignancy has been described in the 10-15% of the reported cases. We report our series of 6 patients diagnosticated of this illness in our department. One of this patients has Sweet syndrome associated with a malignancy disorder. All of them had diagnostic criteria of the described disease and had good response to corticotherapy. We also report a bibliographic review of this infrequent syndrome.

[HELLP syndrome: case report and review of the literature]

The case of a 32-years-old primipara in her thirty-second week of pregnancy who presented acute epigastric pain, citopenia, elevation in hepatic enzymes and analytical signs of hemolysis is presented. Ultrasonography demonstrated multiple hyperechogenic nodular images in the liver leading to a wide differential diagnosis. Liver biopsy findings, together with the mentioned clinico-biological alterations were indicative of the HELLP syndrome. Following caesarean, the patient presented rapid and total, symptomatic and analytical, improvement. Based on this case, a review of this entity in the literature and its prognostic implications and possible therapeutic approaches are reported.