General-purpose programmable photonic processor for advanced radiofrequency applications.

A general-purpose photonic processor can be built integrating a silicon photonic programmable core in a technology stack comprising an electronic monitoring and controlling layer and a software layer for resource control and programming. This processor can leverage the unique properties of photonics in terms of ultra-high bandwidth, high-speed operation, and low power consumption while operating in a complementary and synergistic way with electronic processors. These features are key in applications such as next-generation 5/6 G wireless systems where reconfigurable filtering, frequency conversion, arbitrary waveform generation, and beamforming are currently provided by microwave photonic subsystems that cannot be scaled down. Here we report the first general-purpose programmable processor with the remarkable capability to implement all the required basic functionalities of a microwave photonic system by suitable programming of its resources. The processor is fabricated in silicon photonics and incorporates the full photonic/electronic and software stack.

Long-Term Outcomes of Biological Therapy in Crohn's Disease Complicated With Internal Fistulizing Disease: BIOSCOPE Study From GETECCU.

INTRODUCTION: The prevalence of penetrating complications in Crohn's disease (CD) increases progressively over time, but evidence on the medical treatment in this setting is limited. The aim of this study was to evaluate the effectiveness of biologic agents in CD complicated with internal fistulizing disease. METHODS: Adult patients with CD-related fistulae who received at least 1 biologic agent for this condition from the prospectively maintained ENEIDA registry were included. Exclusion criteria involved those receiving biologics for perianal disease, enterocutaneous, rectovaginal, anastomotic, or peristomal fistulae. The primary end point was fistula-related surgery. Predictive factors associated with surgery and fistula closure were evaluated by multivariate logistic regression and survival analyses. RESULTS: A total of 760 patients from 53 hospitals (673 receiving anti-tumor necrosis factors, 69 ustekinumab, and 18 vedolizumab) were included. After a median follow-up of 56 months (interquartile range, 26-102 months), 240 patients required surgery, with surgery rates of 32%, 41%, and 24% among those under anti-tumor necrosis factor, vedolizumab, or ustekinumab, respectively. Fistula closure was observed in 24% of patients. Older patients, ileocolonic disease, entero-urinary fistulae, or an intestinal stricture distal to the origin of the fistula were associated with a higher risk of surgery, whereas nonsmokers and combination therapy with an immunomodulator reduced this risk. DISCUSSION: Biologic therapy is beneficial in approximately three-quarters of patients with fistulizing CD, achieving fistula closure in 24%. However, around one-third still undergo surgery due to refractory disease. Some patient- and lesion-related factors can identify patients who will obtain more benefit from these drugs.

Therapeutic Properties and Use of Extra Virgin Olive Oil in Clinical Nutrition: A Narrative Review and Literature Update.

Extra virgin olive oil (EVOO) is a cornerstone of the Mediterranean diet (MedD). In this narrative review, we synthesize and illustrate the various characteristics and clinical applications of EVOO and its components-such as oleic acid, hydroxytyrosol, and oleuropein-in the field of clinical nutrition and dietetics. The evidence is split into diet therapy, oleic acid-based enteral nutrition formulations and oral supplementation formulations, oleic acid-based parenteral nutrition, and nutraceutical supplementation of minor components of EVOO. EVOO has diverse beneficial health properties, and current evidence supports the use of whole EVOO in diet therapy and the supplementation of its minor components to improve cardiovascular health, lipoprotein metabolism, and diabetes mellitus in clinical nutrition. Nevertheless, more intervention studies in humans are needed to chisel specific recommendations for its therapeutic use through different formulations in other specific diseases and clinical populations.

Inflammatory bowel disease integral care units: Evaluation of a nationwide quality certification programme. The GETECCU experience.

BACKGROUND: One of the most valued targets in inflammatory bowel disease (IBD) is for physicians to provide and patients to receive a high-level quality of care. This study aimed to evaluate the implementation of a nationwide quality certification programme for IBD units. METHODS: Identification of quality indicators (QI) for IBD Unit certification was based on Delphi methodology that selected 53 QI, which were subjected to a normalisation process. Selected QI were then used in the certification process. Coordinated by GETECCU, this process began with a consulting round and an audit drill followed by a formal audit carried out by an independent certifying agency. This audit involved the scrutiny of the selected QI in medical records. If 80%-90% compliance was achieved, the IBD unit audited received the qualification of "advanced", and if it exceeded 90% the rating was "excellence". Afterwards, an anonymous survey was conducted among certified units to assess satisfaction with the programme for IBD units. RESULTS: As of January 2021, 66 IBD units adhere to the nationwide certification programme. Among the 53 units already audited by January 2021, 31 achieved the certification of excellence, 20 the advanced certification, and two did not obtain the certification. The main survey results indicated high satisfaction with an average score of 8.5 out of 10. CONCLUSION: Certification of inflammatory bowel disease units by GETECCU is the largest nationwide certification programme for IBD units reported. More than 90% of IBD units adhered to the programme achieved the certification.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 2: Treatment. / Recomendaciones del Grupo Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa (GETECCU) sobre la reservoritis en la colitis ulcerosa. Parte 2: Tratamiento.

Pouchitis treatment is a complex entity that requires a close medical and surgical relationship. The elective treatment for acute pouchitis is antibiotics. After a first episode of pouchitis it is recommended prophylaxis therapy with a probiotic mix, nevertheless it is not clear the use of this formulation for preventing a first episode of pouchitis after surgery. First-line treatment for chronic pouchitis is an antibiotic combination. The next step in treatment should be oral budesonide. Selected cases of severe, chronic refractory pouchitis may benefit from biologic agents, and anti-TNF α should be recommended as the first option, leaving the new biologicals for multi-refractory patients. Permanent ileostomy may be an option in severe refractory cases to medical treatment.

Lignin from Tree Barks: Chemical Structure and Valorization.

Lignins from different tree barks, including Norway spruce (Picea abies), eucalyptus (Eucalyptus globulus), mimosa (Acacia dealbata) and blackwood acacia (A. melanoxylon), are thoroughly characterized. The lignin from E. globulus bark is found to be enriched in syringyl (S) units, with lower amounts of guaiacyl (G) and p-hydroxyphenyl (H) units (H/G/S ratio of 1:26:73), which produces a lignin that is highly enriched in ß-ether linkages (83 %), whereas those from the two Acacia barks have similar compositions (H/G/S ratio of ≈5:50:45), with a predominance of ß-ethers (73-75 %) and lower amounts of condensed carbon-carbon linkages; the lignin from A. dealbata bark also includes some resorcinol-related compounds, that appear to be incorporated or intimately associated to the polymer. The lignin from P. abies bark is enriched in G units, with lower amounts of H units (H/G ratio of 14:86); this lignin is thus depleted in ß-O-4' alkyl-aryl ether linkages (44 %) and enriched in condensed linkages. Interestingly, this lignin contains large amounts of hydroxystilbene glucosides that seem to be integrally incorporated into the lignin structure. This study indicates that lignins from tree barks can be seen as an interesting source of valuable phenolic compounds. Moreover, this study is useful for tailoring conversion technologies for bark deconstruction and valorization.

Analytical characterization of trace elements (zinc, copper, cadmium, lead and selenium) in saliva of pigs under common pathological conditions in the field: a pilot study.

BACKGROUND: This study is focused on the measurement of trace elements (zinc, copper, cadmium, lead and selenium) in the saliva of pigs in order to study their levels on different porcine pathological conditions in the field. The experiment involved 15 pigs without clinical signs of disease and 42 diseased pigs (suffering from lameness, rectal prolapse, fatigue or growth rate retardation). Individual saliva samples were collected, allowing the pigs to chew a sponge each for trace element quantifications through atomic absorption spectrometry (AAS). Since this is the first report on the measurements of trace elements in porcine saliva, a routine analytical validation study was performed for the quantification of all the studied elements. Moreover, the acute phase proteins C-reactive protein (CRP) and haptoblobin (Hp), the total antioxidant capacity (TAC) and adenosine deaminase (ADA) were quantified in the saliva samples for the animal's health status assessment. RESULTS: Modifications in the levels of acute phase proteins or ADA were only recorded in animals with lameness and rectal prolapse and those with fatigue respectively. Moreover, TAC level changes were observed in pigs with growth-rate retardation. However, alterations in the levels of two or more trace elements were reported for all the different groups of diseased pigs with evident variations within pathologies. CONCLUSIONS: The salivary quantification of trace elements could be considered as a complementary tool to acute phase proteins, TAC and ADA determinations for disease detection and differentiation in the pig and should be explored in greater depth.

Sonotherapy in the reduction of anxiety and postoperative pain in patients with regional anesthesia as a sole technique: randomized, controlled clinical trial.

OBJECTIVE: To determine if sonotherapy reduces the anxiety level and postoperative pain in adults undergoing outpatient orthopedic surgery under regional anesthesia. METHOD: A randomized, double-blind, placebo-controlled study in 80 adult patients undergoing orthopedic surgery, 40 received intervention with sonotherapy and 40 did not receive it. Pain, anxiety in the preoperative period, immediate postoperative, high, 24 and 48 hours later were measured. Hemodynamic parameters were measured in four moments. RESULTS: No significant differences were found between the two groups in the pain scales neither anxiety. A significant reduction of the systolic blood pressure was observed after the application of sonotherapy and in recovery. There was no difference in other hemodynamic variables such as heart rate, respiratory rate, arterial oxygen saturation or diastolic blood pressure between groups, however, the observed changes in some of them occurred faster in the intervention group. CONCLUSIONS: In adult patients undergoing outpatient orthopaedic surgery under regional anaesthesia, sound therapy is a novel strategy that significantly reduces systolic blood pressure, considered as an indicator of decreased anxiety. However, in our study, no difference could be demonstrated in terms of pain control or the need for additional sedation or analgesia.

OBJETIVO: Evaluar la eficacia de la sonoterapia en la diminución de la ansiedad y el dolor posoperatorio en adultos llevados a cirugía ambulatoria de ortopedia bajo anestesia regional. MÉTODO: estudio aleatorizado, doble ciego, controlado con placebo, en 80 pacientes adultos sometidos a cirugía ortopédica; 40 recibieron intervención con sonoterapia y 40 no la recibieron. Se midieron el dolor y la ansiedad en el preoperatorio, en el posoperatorio inmediato, al alta, y 24 y 48 horas después. Se midieron parámetros hemodinámicos en cuatro momentos. RESULTADOS: No se encontraron diferencias significativas entre ambos grupos en las escalas de dolor ni ansiedad. Se observó una reducción significativa de la presión arterial sistólica luego de la aplicación de la intervención y en recuperación. No se observaron diferencias en otras variables hemodinámicas entre los grupos, pero la reducción de algunas ocurre de forma más rápida en el grupo de intervención. CONCLUSIONES: En pacientes adultos llevados a cirugía ambulatoria de ortopedia bajo anestesia regional, la sonoterapia es una estrategia novedosa que reduce la presión arterial sistólica, y esto puede considerarse como un indicador de disminución de la ansiedad. En nuestro estudio no se pudo demostrar diferencia en términos de control del dolor ni de requerimiento de sedación o analgesia adicional.

Isolation and structural characterization of the milled wood lignin, dioxane lignin, and cellulolytic lignin preparations from brewer's spent grain.

The structure of the lignin from brewer's spent grain (BSG) has been studied in detail. Three different lignin preparations, the so-called "milled-wood" lignin (MWL), dioxane lignin (DL), and cellulolytic lignin (CEL), were isolated from BSG and then thoroughly characterized by pyrolysis GC/MS, 2D-NMR, and derivatization followed by reductive cleavage (DFRC). The data indicated that BSG lignin presents a predominance of guaiacyl units (syringyl/guaiacyl ratio of 0.4-0.5) with significant amounts of associated p-coumarates and ferulates. The flavone tricin was also present in the lignin from BSG, as also occurred in other grasses. 2D-NMR (HSQC) revealed that the main substructures present are ß-O-4' alkyl-aryl ethers (77-79%) followed by ß-5' phenylcoumarans (11-13%) and lower amounts of ß-ß' resinols (5-6%) and 5-5' dibenzodioxocins (3-5%). The results from 2D-NMR (HMBC) and DFRC indicated that p-coumarates are acylating the γ-carbon of lignin side chains and are mostly involved in condensed structures. DFRC analyses also indicated a minor degree of γ-acylation with acetate groups, which takes place preferentially on S lignin (6% of S units are acetylated) over G lignin (only 1% of G units are acetylated).

Se metallomics during lactic fermentation of Se-enriched yogurt.

Selenium biotransformation by lactic acid bacteria during the preparation of Se-enriched yogurt was evaluated. The study focused on the distribution of selenium in the aqueous soluble protein fraction and the detection of selenoamino acids. Screening of selenium in Tris-buffer-urea soluble fraction was carried out by sodium dodecyl sulphate polyacrylamide gel electrophoresis after pre-fractionating with asymmetric field flow fractionation using inductively coupled plasma-mass spectrometry as the detector. Selenium-containing fractions were identified by peptide mapping using nano LC-ESI/LTQMS. Proteins such as thioredoxin, glutaredoxin, albumin, ß-lactoglobulin, and lactoperoxidase were identified in the selenium-containing fraction. All these proteins were detected in both the control and the selenium-enriched yogurt except chaperones, which were only detected in the control samples. Chaperones are heat-shock proteins expressed in response to elevated temperature or other cellular stresses. Selenium may have an effect on chaperones expression in Lactobacillus. For the amino acids analysis, selenocysteine was the primary seleno-containing species.

Intensive nutritional support improves the nutritional status and body composition in severely malnourished children with cerebral palsy / El apoyo nutricio intensivo mejora el estado nutricio y la composición corporal en niños gravemente desnutridos con parálisis cerebral

Objective: To demonstrate that a nutritional support intervention, via naso-enteral tube-feeding or gastrostomy, has a significant impact on the nutritional status and body composition in severely malnourished children with cerebral palsy spastic quadriplegia Methods: Thirteen patients with moderate/severe malnutrition and cerebral palsy spastic quadriplegia who were fed via naso-enteral tube-feeding or gastrostomy were included in a cohort study. Anthropometric measurements and estimated body composition by bioelectric impedance analysis were obtained. ANOVA and Wilcoxon tests were used. Results: During the four weeks of nutritional recovery, an average weight increase of 2700 g was achieved. There were significant increases in anthropometric indicators, including BMI and weight/length (p < 0.01). The increase in arm fat area was significantly higher than the increase in arm muscle area (104.5 vs 17.5%). Conclusion: Intensive nutritional support for four weeks had a significant effect on the nutritional status and body composition of severe and moderately malnourished children with cerebral palsy spastic quadriplegia (AU)

Objetivo: Demostrar que el apoyo nutricio intensivo por vía naso-enteral o gastrostomía tiene un impacto significativo en el estado nutricio y en la composición corporal en niños desnutridos graves con parálisis cerebral cuadriplejia espástica. Métodos: En un estudio de cohorte se incluyeron trece pacientes con desnutrición moderada/grave y parálisis cerebral cuadriplejia espástica, quienes fueron alimentados por vía naso-enteral o gastrostomía. Fueron obtenidos indicadores antropométricos y de composición corporal estimada por antropometría e impedancia bio-eléctrica. Se utilizó ANOVA y prueba de Wilcoxon para el análisis estadístico. Resultados: Hubo un aumento de 2700 g durante las cuatro semanas de recuperación nutricia y un incremento significativo en los indicadores antropométricos, índice de masa corporal y peso/talla (p < 0,01). El porcentaje de incremento del área grasa del brazo fue mayor que el área muscular del brazo (104,5 vs 17,5%). Conclusión: El apoyo nutricio intensivo tuvo un efecto significativo en el estado nutricio y en la composición corporal de niños con desnutrición moderada/grave con parálisis cerebral infantil (AU)

Genetic susceptibility to increased bacterial translocation influences the response to biological therapy in patients with Crohn's disease.

OBJECTIVE: The aetiology of Crohn's disease (CD) has been related to nucleotide-binding oligomerisation domain containing 2 (NOD2) and ATG16L1 gene variants. The observation of bacterial DNA translocation in patients with CD led us to hypothesise that this process may be facilitated in patients with NOD2/ATG16L1-variant genotypes, affecting the efficacy of anti-tumour necrosis factor (TNF) therapies. DESIGN: 179 patients with Crohn's disease were included. CD-related NOD2 and ATG16L1 variants were genotyped. Phagocytic and bactericidal activities were evaluated in blood neutrophils. Bacterial DNA, TNFα, IFNγ, IL-12p40, free serum infliximab/adalimumab levels and antidrug antibodies were measured. RESULTS: Bacterial DNA was found in 44% of patients with active disease versus 23% of patients with remitting disease (p=0.01). A NOD2-variant or ATG16L1-variant genotype was associated with bacterial DNA presence (OR 4.8; 95% CI 1.1 to 13.2; p=0.001; and OR 2.4; 95% CI 1.4 to 4.7; p=0.01, respectively). This OR was 12.6 (95% CI 4.2 to 37.8; p=0.001) for patients with a double-variant genotype. Bacterial DNA was associated with disease activity (OR 2.6; 95% CI 1.3 to 5.4; p=0.005). Single and double-gene variants were not associated with disease activity (p=0.19). Patients with a NOD2-variant genotype showed decreased phagocytic and bactericidal activities in blood neutrophils, increased TNFα levels in response to bacterial DNA and decreased trough levels of free anti-TNFα. The proportion of patients on an intensified biological therapy was significantly higher in the NOD2-variant groups. CONCLUSIONS: Our results characterise a subgroup of patients with CD who may require a more aggressive therapy to reduce the extent of inflammation and the risk of relapse.

Understanding pulp delignification by laccase-mediator systems through isolation and characterization of lignin-carbohydrate complexes.

The effects and mechanism of pulp delignification by laccases in the presence of redox mediators have been investigated on unbleached eucalyptus kraft pulp treated with laccases from Pycnoporus cinnabarinus (PcL) and Myceliophthora thermophila (MtL) and 1-hydroxybenzotriazole (HBT) and methyl syringate (MeS) as mediators, respectively. Determination of the corrected κ number in eucalyptus pulps after the enzymatic treatments revealed that the PcL-HBT system exhibited a more remarkable delignification effect than the MtL-MeS system. To obtain further insight, lignin-carbohydrate complexes were fractionated and subsequently characterized by nuclear magnetic resonance, thioacidolysis (followed by gas chromatography and size exclusion chromatography), and pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS) analyses before and after the enzymatic treatments and their controls. We can conclude that the laccase-mediator treatments altered the lignin structures in such a way that more lignin was recovered in the xylan-lignin fractions, as shown by Klason lignin estimation, with smaller amounts of both syringyl (S) and guaiacyl (G) uncondensed units, as shown by thioacidolysis and gas chromatography, especially after the PcL-HBT treatment. The laccase-mediator treatment produced oxidation at Cα and cleavage of Cα and Cß bonds in pulp lignin, as shown by pyrolysis-GC-MS. The general mechanism of residual lignin degradation in the pulp by laccase-mediator treatments is discussed in light of the results obtained.

Structural characterization of lignin isolated from coconut (Cocos nucifera) coir fibers.

The structure of the isolated milled "wood" lignin from coconut coir has been characterized using different analytical methods, including Py-GC/MS, 2D NMR, DFRC, and thioacidolysis. The analyses demonstrated that it is a p-hydroxyphenyl-guaiacyl-syringyl (H-G-S) lignin, with a predominance of G units (S/G ratio 0.23) and considerable amounts of associated p-hydroxybenzoates. Two-dimensional NMR indicated that the main substructures present in this lignin include ß-O-4' alkyl aryl ethers followed by phenylcoumarans and resinols. Two-dimensional NMR spectra also indicated that coir lignin is partially acylated at the γ-carbon of the side chain with p-hydroxybenzoates and acetates. DFRC analysis showed that acetates preferentially acylate the γ-OH in S rather than in G units. Despite coir lignin's being highly enriched in G-units, thioacidolysis indicated that ß-ß' resinol structures are mostly derived from sinapyl alcohol. Finally, we find evidence that the flavone tricin is incorporated into the coconut coir lignin, as has been recently noted for various grasses.

A comprehensive characterization of lipids in wheat straw.

The chemical composition of the lipids in wheat straw was studied in detail by gas chromatography and mass spectrometry. Important discrepancies with the data reported in previous papers were found. The predominant lipids identified were series of long-chain free fatty acids (25% of total extract), followed by series of free fatty alcohols (ca. 20%). High molecular weight esters of long chain fatty acids esterified to long chain fatty alcohols were also found (11%), together with lower amounts of other aliphatic series, such as n-alkanes, n-aldehydes, and glycerides (mono-, di-, and triglycerides). Relatively high amounts of ß-diketones (10%), particularly 14,16-hentriacontanedione, which is the second most abundant single compound among the lipids in wheat straw, were also identified. Finally, steroid compounds (steroid hydrocarbons, steroid ketones, free sterols, sterol esters, and sterol glycosides) were also found, with sterols accounting for nearly 14% of all identified compounds.

Lipophilic extractives from the cortex and pith of elephant grass ( Pennisetum purpureum Schumach.) stems.

The composition of lipophilic extractives in the cortex and pith of elephant grass ( Pennisetum purpureum Schumach.) stems was thoroughly studied by gas chromatography-mass spectrometry. The predominant compounds were fatty acids followed by sterols (in free and conjugated forms as esters and glycosides). Other steroid compounds, as steroid hydrocarbons and ketones, were also present. Additionally, important amounts of mono-, di-, and triglycerides were identified. Other aliphatic series such as n-alkanes, n-fatty alcohols, and n-alkyl ferulates, together with tocopherols and a series of high molecular weight esters, were also found, although in minor amounts. The analyses also revealed the presence of a ß-diketone (12,14-tritriacontanedione), which was particularly abundant in the cortex. Finally, two lignans, matairesinol and syringaresinol, were also detected. In general terms, the abundances of the different classes of compounds were higher in the pith, except for the series of n-fatty alcohols, n-alkyl ferulates, ß-diketones, and lignans, which were more prominent in the cortex.

Demonstration of laccase-based removal of lignin from wood and non-wood plant feedstocks.

The ability of Trametes villosa laccase, in conjuction with 1-hydroxybenzotriazole (HBT) as mediator and alkaline extraction, to remove lignin was demonstrated during treatment of wood (Eucalyptus globulus) and non-wood (Pennisetum purpureum) feedstocks. At 50 Ug(-1) laccase and 2.5% HBT concentration, 48% and 32% of the Eucalyptus and Pennisetum lignin were removed, respectively. Two-dimensional nuclear magnetic resonance of the feedstocks, swollen in dimethylsulfoxide-d(6), revealed the removal of p-hydroxyphenyl, guaiacyl and syringyl lignin units and aliphatic (mainly ß-O-4'-linked) side-chains of lignin, and a moderate removal of p-coumaric acid (present in Pennisetum) without a substantial change in polysaccharide cross-signals. The enzymatic pretreatment (at 25 Ug(-1)) of Eucalyptus and Pennisetum feedstocks increased the glucose (by 61% and 12% in 72 h) and ethanol (by 4 and 2 g L(-1) in 17 h) yields from both lignocellulosic materials, respectively, as compared to those without enzyme treatment.

Towards industrially-feasible delignification and pitch removal by treating paper pulp with Myceliophthora thermophila laccase and a phenolic mediator.

The ability of two natural phenols to act as mediators of the recombinant Myceliophthora thermophila laccase (MtL) in eucalypt-pulp delignification was investigated. After alkaline peroxide extraction, the properties of the enzymatically-treated pulps improved with respect to the control. The pulp brightness increased (3.1 points) after the enzymatic treatment with MtL alone, but the highest improvements were obtained after the MtL treatment using syringaldehyde (4.7 points) and especially methyl syringate (8.3 points) as mediators. Likewise, a decrease in kappa number up to 2.7 points was obtained after the MtL-methyl syringate treatment, followed by decreases of 1.4 and 0.9 points after the treatments with MtL-syringaldehyde and MtL alone, respectively. On the other hand, removal of the main lipophilic extractives present in eucalypt pulp was observed after the above laccase-mediator treatments. Finally, the doses of both MtL and methyl syringate were reduced, and results compatible with industrial implementation were obtained.

Lipophilic extractives from several nonwoody lignocellulosic crops (flax, hemp, sisal, abaca) and their fate during alkaline pulping and TCF/ECF bleaching.

The fate of lipophilic extractives from several nonwoody species (flax, hemp, sisal and abaca) used for the manufacturing of cellulose pulps, was studied during soda/anthraquinone (AQ) pulping and totally chorine free (TCF) and elemental chlorine free (ECF) bleaching. With this purpose, the lipophilic extracts from the raw materials and their unbleached and bleached industrial pulps, were analyzed by gas chromatography-mass spectrometry. Aldehydes, hydroxyfatty acids and esterified compounds such as ester waxes, sterol esters and alkylferulates strongly decreased after soda/AQ pulping while alkanes, alcohols, free sterols and sterol glycosides survived the cooking process. Among the lipophilic extractives that remained in the unbleached pulps, some amounts of free sterols were still present in the TCF pulps whereas they were practically absent in the ECF pulps. Sterol glycosides were also removed after both TCF and ECF bleaching. By contrast, saturated fatty acids, fatty alcohols and alkanes were still present in both bleached pulps.

Highly acylated (acetylated and/or p-coumaroylated) native lignins from diverse herbaceous plants.

The structure of lignins isolated from the herbaceous plants sisal ( Agave sisalana), kenaf ( Hibiscus cannabinus), abaca ( Musa textilis) and curaua ( Ananas erectifolius) has been studied upon spectroscopic (2D-NMR) and chemical degradative (derivatization followed by reductive cleavage) methods. The analyses demonstrate that the structure of the lignins from these plants is highly remarkable, being extensively acylated at the gamma-carbon of the lignin side chain (up to 80% acylation) with acetate and/or p-coumarate groups and preferentially over syringyl units. Whereas the lignins from sisal and kenaf are gamma-acylated exclusively with acetate groups, the lignins from abaca and curaua are esterified with acetate and p-coumarate groups. The structures of all these highly acylated lignins are characterized by a very high syringyl/guaiacyl ratio, a large predominance of beta- O-4' linkages (up to 94% of all linkages), and a strikingly low proportion of traditional beta-beta' linkages, which indeed are completely absent in the lignins from abaca and curaua. The occurrence of beta-beta' homocoupling and cross-coupling products of sinapyl acetate in the lignins from sisal and kenaf indicates that sinapyl alcohol is acetylated at the monomer stage and that, therefore, sinapyl acetate should be considered as a real monolignol involved in the lignification reactions.