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1.
Psychiatry Res ; 337: 115952, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38723408

ABSTRACT

Our aim is to review and perform a meta-analysis on the role of impulsivity in fatal suicide behaviour. We included papers who used psychological autopsy methodology, assessed adult death by suicide, and included assessment of impulsivity. We excluded papers about assisted suicide, terrorist suicide, or other cause of death other than suicide or postmortem diagnosis made only from medical records or database. 97 articles were identified. 33 were included in the systematic review and nine in the meta-analysis. We found that people who die by suicide with high impulsivity are associated with younger age, substance abuse, and low intention to die, whereas those with low impulsivity were associated with older age, depression, schizophrenia, high intention to die and low social support. In the meta-analysis, suicide cases had higher impulsivity scores than living controls (Hedges' g = 0.59, 95 % CI [0.28, 0.89], p=.002). However, studies showed heterogeneity (Q = 90.86, p<.001, I2=89.0 %). Impulsivity-aggressiveness interaction was assessed through meta-regression (ß=0.447, p=.045). Individuals with high impulsivity would be exposed to a higher risk of fatal suicide behaviour, aggressiveness would play a mediating role. People who die by suicide with high and low impulsivity display distinct characteristics, which may reflect different endophenotypes leading to suicide by different pathways.

2.
Curr Biol ; 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38692277

ABSTRACT

Mitochondrial cristae architecture is crucial for optimal respiratory function of the organelle. Cristae shape is maintained in part by the mitochondrial contact site and cristae organizing system (MICOS) complex. While MICOS is required for normal cristae morphology, the precise mechanistic role of each of the seven human MICOS subunits, and how the complex coordinates with other cristae-shaping factors, has not been fully determined. Here, we examine the MICOS complex in Schizosaccharomyces pombe, a minimal model whose genome only encodes for four core subunits. Using an unbiased proteomics approach, we identify a poorly characterized inner mitochondrial membrane protein that interacts with MICOS and is required to maintain cristae morphology, which we name Mmc1. We demonstrate that Mmc1 works in concert with MICOS to promote normal mitochondrial morphology and respiratory function. Mmc1 is a distant relative of the dynamin superfamily of proteins (DSPs), GTPases, which are well established to shape and remodel membranes. Similar to DSPs, Mmc1 self-associates and forms high-molecular-weight assemblies. Interestingly, however, Mmc1 is a pseudoenzyme that lacks key residues required for GTP binding and hydrolysis, suggesting that it does not dynamically remodel membranes. These data are consistent with the model that Mmc1 stabilizes cristae architecture by acting as a scaffold to support cristae ultrastructure on the matrix side of the inner membrane. Our study reveals a new class of proteins that evolved early in fungal phylogeny and is required for the maintenance of cristae architecture. This highlights the possibility that functionally analogous proteins work with MICOS to establish cristae morphology in metazoans.

3.
Immunity ; 57(4): 790-814, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38599171

ABSTRACT

Activation of the innate immune system following pattern recognition receptor binding has emerged as one of the major pathogenic mechanisms in neurodegenerative disease. Experimental, epidemiological, pathological, and genetic evidence underscores the meaning of innate immune activation during the prodromal as well as clinical phases of several neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and frontotemporal dementia. Importantly, innate immune activation and the subsequent release of inflammatory mediators contribute mechanistically to other hallmarks of neurodegenerative diseases such as aberrant proteostatis, pathological protein aggregation, cytoskeleton abnormalities, altered energy homeostasis, RNA and DNA defects, and synaptic and network disbalance and ultimately to the induction of neuronal cell death. In this review, we discuss common mechanisms of innate immune activation in neurodegeneration, with particular emphasis on the pattern recognition receptors (PRRs) and other receptors involved in the detection of damage-associated molecular patterns (DAMPs).


Subject(s)
Neurodegenerative Diseases , Humans , Receptors, Pattern Recognition , Immune System , Inflammation Mediators , Immunity, Innate
4.
Phys Rev Lett ; 132(7): 077401, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38427871

ABSTRACT

Contagion processes relying on the exposure to multiple sources are prevalent in social systems, and are effectively represented by hypergraphs. In this Letter, we derive a mean-field model that goes beyond node- and pair-based approximations. We reveal how the stability of the contagion-free state is decided by either two- or three-body interactions, and how this is strictly related to the degree of overlap between these interactions. Our findings demonstrate the dual effect of increased overlap: it lowers the invasion threshold, yet produces smaller outbreaks. Corroborated by numerical simulations, our results emphasize the significance of the chosen representation in describing a higher-order process.

5.
Therap Adv Gastroenterol ; 17: 17562848241230904, 2024.
Article in English | MEDLINE | ID: mdl-38425369

ABSTRACT

Background: Despite recent emerging literature involving the utility of endoscopic balloon dilation (EBD) of strictures via balloon-assisted endoscopy (BAE), specifically regarding the management of Crohn's disease (CD), the optimal clinical approach with balloon systems has been largely neglected in academic literature. Objectives: This study assesses the intra-procedural success and safety of EBD via BAE for small bowel CD strictures while detailing our clinical approach and technique. Secondarily, we compare the single-balloon endoscope (SBE) and double-balloon endoscope (DBE) systems for EBD-related outcomes. Design: Retrospective consecutive patient cohort analysis. Methods: We retrospectively assessed a consecutive small bowel CD patient cohort undergoing BAE at the University of Alberta Hospital endoscopy unit from 2013 to 2020. The primary endpoint discerned the safety and immediate success rate of EBD during endoscopy, and comparisons of the dilation parameters and efficacy of SBE versus DBE were assessed as secondary outcomes. Results: During the study period, 87 patients (44 male) with a mean age of 56 ± 14.7 years underwent 179 endoscopic procedures (92 DBE and 87 SBE). Of 358 strictures encountered, 320 (89.4%) were successfully dilated and traversed. The mean maximum dilation diameter was 15.76 ± 2.10 mm. There were no perforations or major adverse events. Conclusion: EBD via BAE is a safe procedure in small bowel CD with a high intraprocedural success rate. Overall, SBE had a higher success rate in traversing strictures before and after dilation using our technique. This analysis is limited by the retrospective nature of our study and must be balanced against the inherent benefits of the DBE system.


Outcome and approach of small-bowel stricture dilation using balloon-assisted endoscopy in patients with Crohn's disease This study investigated the safety and success of using balloon-assisted endoscopy as a method to dilate small bowel strictures in patients with Crohn's disease. As a secondary outcome, we compared the overall safety and success between two different types of endoscopic systems: the single- and double-balloon systems.

6.
Trends Microbiol ; 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38307786

ABSTRACT

The evolutionary history of cells has been marked by drastic increases in complexity. Some hypothesize that such cellular complexification requires a massive energy flux as the origin of new features is hypothetically more energetically costly than their evolutionary maintenance. However, it remains unclear how increases in cellular complexity demand more energy. I propose that the early evolution of new genes with weak functions imposes higher energetic costs by overexpression before their functions are evolutionarily refined. In the long term, the accumulation of new genes deviates resources away from growth and reproduction. Accrued cellular complexity further requires additional infrastructure for its maintenance. Altogether, this suggests that larger and more complex cells are defined by increased survival but lower reproductive capacity.

7.
World Neurosurg ; 183: e781-e786, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38216035

ABSTRACT

BACKGROUND: Few studies have compared the Pipeline Shield stents with previous generations of flow-diverting stents (FDSs) for the treatment of unruptured intracranial aneurysms. This study aimed to evaluate the efficacy and safety of Pipeline Shield stents and FDSs without modified surfaces. METHODS: The present evaluation is a retrospective cohort study of patients endovascularly treated with Pipeline Shield stents or FDSs without modified surfaces for unruptured intracranial aneurysms between January 2014 and June 2022. The data analyzed were obtained from the anonymized database of our institution's interventional radiology service. RESULTS: A total of 147 patients with 155 unruptured intracranial aneurysms were included. Of the 155 aneurysms, 96 were treated with Pipeline Shield stents and 59 with FDSs without modified surfaces. The aneurysms treated with Pipeline Shield stents had higher 6-month (O'Kelly-Marotta [OKM] D; 87.5% vs. 71.4%; P = 0.025) and 1-year (OKM D; 82.5% vs. 63.0%; P = 0.047) occlusion rates than the aneurysms treated using FDSs without modified surfaces. No differences between the devices were found at the 1-year follow-up in the incidence of ischemic stroke (P = 0.939) or hemorrhagic complications (P = 0.559). CONCLUSIONS: Pipeline Shield stents demonstrated superior complete occlusion rates (OKM D) at both the 6-month and the 1-year follow-up assessments compared with nonmodified surface FDSs. No significant differences were found in the safety profiles between the 2 types of stents with regard to thromboembolic complications and ischemic events. Further research with larger study populations is necessary to validate these findings.


Subject(s)
Embolization, Therapeutic , Endovascular Procedures , Intracranial Aneurysm , Humans , Intracranial Aneurysm/complications , Retrospective Studies , Treatment Outcome , Stents/adverse effects
9.
Molecules ; 29(2)2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38276569

ABSTRACT

The production of human recombinant proteins to be used for therapeutic or nutritional purposes must focus on obtaining a molecule that is as close as possible to the native human protein. This biotechnological tool has been documented in various studies published in recent decades, with lactoferrin being one of those that has generated the most interest, being a promising option for recombinant technology. However, stability studies including thermodynamic parameters have not been reported for recombinant lactoferrin (Lf). The objective of this work was to obtain the human recombinant protein using the yeast Komagataella phaffii to study structural changes modifying pH and temperature using circular dichroism spectroscopy (CD). Thermodynamic parameters such as ΔH, ΔS and Tm were calculated and compared with commercial human lactoferrin. We propose the potential use of CD and thermodynamic parameters as a criterion in the production of recombinant proteins to be used in the production of specialized recombinant proteins.


Subject(s)
Lactoferrin , Humans , Lactoferrin/chemistry , Circular Dichroism , Recombinant Proteins/metabolism , Temperature , Hydrogen-Ion Concentration
10.
Am J Ophthalmol ; 260: 122-131, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38056608

ABSTRACT

PURPOSE: To evaluate the progression of myopia as assessed by change in axial length (AL) and spherical equivalent (SE) from baseline in Caucasian children wearing extended depth of focus soft contact lenses (CLs) compared to distance single-vision spectacles. DESIGN: Prospective non-randomized comparative clinical trial. METHODS: A total of 90 children (6-13 years of age) with SE ranging from -0.75 to -10.00 diopters (D) were recruited. Of these children, 45 were fitted with CLs (MYLO, mark´ennovy), whereas 45 children wore spectacles. Cycloplegic refraction was measured with an auto-refractometer (Topcon-TRK-2P) and AL with an IOLMaster-700 (Zeiss) at 6-month intervals. Subjective responses after 1 month of CL wear related to vision and comfort were determined using a questionnaire with a scale from 1 (very poor) to 10 (excellent). High-contrast visual acuity (HCVA) and contrast sensitivity (CS) were evaluated at baseline, 12, and 24 months. RESULTS: After 2 years, mean change in SE/AL in the CL group was -0.62 ± 0.30 D/0.37 ± 0.04 mm and -1.13 ± 0.20 D/0.66 ± 0.03 mm in the spectacles group (P < .001). Cumulative absolute reduction in axial elongation (CARE) was 0.29 ± 0.06 mm. Difference in SE change was -0.50 ± 0.34 D. Although 100% of CL group had an AL increase ≤0.50 mm, all participants increased ≥0.50 mm in the spectacles group. In all, 53% of the CL group and 1% in the spectacles group showed a progression in SE ≤ -0.50D. All questionnaire items showed a mean value ≥9. There was a reduction logMAR HCVA in the CL compared to the spectacles group but it was less than 1 line (P < .001). CONCLUSIONS: Use of MYLO CLs reduced axial elongation and myopia progression compared to use of distance single-vision spectacles.


Subject(s)
Contact Lenses, Hydrophilic , Myopia , Child , Humans , Disease Progression , Myopia/therapy , Prospective Studies , Refraction, Ocular , Visual Acuity , Adolescent
11.
12.
Article in English | LILACS-Express | LILACS | ID: biblio-1536577

ABSTRACT

Introduction: The COVID-19 pandemic has had a direct impact on mental health. Inter national organisations have emphasised the vulnerability of indigenous people. Digital Mental Health approaches deliver online therapy as an evidence-based, effective, and accessible treat ment option for common mental health problems. However, the evidence regarding these ap proaches is limited in indigenous populations. The objective of this study is to describe the design, development, and evaluation of the efficacy of a self-applied online intervention regarding the psychological symptoms of depression, anxiety, and fear of COVID-19 in a sample of the Maya population. Method: A prospective longitudinal quantitative study was designed, where a single group was measured before and after receiving the online intervention. This study took place from April to September 2021 and consisted of six sessions delivered via WhatsApp in Spanish and Mayan. Results: The initial assessment was implemented with 82 participants who were evaluated using the Patient Health Questionnaire, Scale for Generalised Anxiety Disorder and the Fear of COVID-19 Scale; 18 participants remained in the intervention for the post-as sessment. Statistical differences were observed in PRE and POST measures of depression and anxiety, but not in fear of COVID-19. Conclusions: This study produced positive results for the first online mental health intervention implemented in the Latin American indigenous pop ulation. Future studies might consider developing similar interventions for other indigenous communities in Latin America.


Introducción: La pandemia de COVID-19 tuvo impacto directo en la salud mental. Organizaciones internacionales han enfatizado la vulnerabilidad de los pueblos indígenas. Los enfoques de salud mental digital brindan terapia en línea como una opción de tratamiento basada en evidencia, efectiva y accesible; sin embargo, los datos son limitados en población indígena. El objetivo de este estudio fue describir el diseño, desarrollo y evaluación de la eficacia de una intervención en línea autoaplicada sobre síntomas psicológicos de depresión, ansiedad y miedo al COVID-19 en una muestra de población maya. Método: Se diseñó un es tudio cuantitativo longitudinal prospectivo, donde se midió a un solo grupo antes y después de recibir la intervención en línea, implementada de abril a septiembre de 2021, que constó de seis sesiones impartidas vía WhatsApp, en español y maya. Resultados: La evaluación inicial se implementó con 82 participantes que fueron evaluados mediante el Cuestionario de Salud del Paciente, Escala para el Trastorno de Ansiedad Generalizada y Escala de Miedo al COVID-19; 18 participantes permanecieron para la evaluación posterior. Se observaron di ferencias estadísticas en las medidas pre- y post- de depresión y ansiedad, pero no miedo al COVID-19. Conclusiones: Este estudio arrojó resultados positivos de la primera intervención de salud mental en línea implementada en la población indígena latinoamericana. Estudios futuros podrían considerar el desarrollo de intervenciones similares para otras comunidades indígenas en América Latina.

13.
Article in English | MEDLINE | ID: mdl-37979784

ABSTRACT

INTRODUCTION: Psychological autopsy methods often include measures of impulsivity and aggression. The aim is to assess their reliability and validity in a Spanish sample. METHODS: Cross-sectional web-based survey was fulfilled by 184 proband and proxy pairs. Data was collected on sociodemographic characteristics, impulsivity through Barratt Impulsiveness Scale (BIS-11), aggression through Buss-Perry Aggression Questionnaire (BPAQ), and history of suicide ideation. Proxies filled out BIS-11, BPAQ and suicide ideation with the responses they would expect from the probands. Reliability was assessed using intraclass correlation coefficients (ICC) between proband and proxies. Logistic regression analysis was performed to assess the predictive validity of proxy reports in predicting probands' suicide ideation. RESULTS: Bivariate analysis showed differences in BPAQ (Median 68 vs. 62; p=0.001), but not in BIS-11 (p>.050). BIS-11 showed good concordance (ICC=0.754; CI 95% 0.671-0.816) and BPAQ acceptable (ICC=0.592; CI 95% 0.442-0.699). In the probands regression model BPAQ predicted suicide ideation (OR 1.038; CI 95% 1.016-1.061) but not BIS-11 (OR 0.991; CI 95% 0.958-1.025). In the proxy-report model BPAQ also predicted probands' suicide ideation (OR 1.036; CI 95% 1.014-1.058) but not BIS-11 (OR 0.973; CI 95% 0.942-1.004). CONCLUSION: Used as proxy-reported assessment tools, BIS-11 showed better reliability than the BPAQ. However, both showed validity in Spanish population and could be included in psychological autopsy protocols.

14.
J Clin Med ; 12(19)2023 Oct 06.
Article in English | MEDLINE | ID: mdl-37835024

ABSTRACT

PURPOSE: This study evaluated the agreement and reproducibility of ACA measurements obtained using the built-in software of the CASIA2 (Version 3G.1) and the measurements derived from expert clinicians. METHODS: Healthy volunteers underwent ophthalmological evaluation and AS-OCT examination. ACA measurements derived from automated and manual SS location were obtained using the CASIA2 automated software and clinician identification, respectively. The intraobserver, interobserver reproducibility, CASIA2-human grader reproducibility and CASIA2 repeatability were assessed using intraclass correlation coefficients (ICCs). RESULTS: The study examined 58 eyes of 30 participants. The CASIA2 software showed excellent repeatability for all ACA parameters (ICC > 0.84). Intraobserver, interobserver, and CASIA2-human grader reproducibility were also excellent (ICC > 0.87). Interobserver agreement was high, except for nasal TISA500, differing between observers 1 and 2 (p < 0.05). The agreement between CASIA2 measurements and human graders was high, except for nasal TISA500, where observer 1 values were smaller (p < 0.05). CONCLUSION: The CASIA2 built-in software reliably measures ACA parameters in healthy individuals, demonstrating high consistency. Although a small difference was observed in nasal TISA500 measurements, interobserver and CASIA2-human grader reproducibility remained excellent. Automated SS detection has the potential to facilitate evaluation and monitoring of primary angle closure disease.

15.
bioRxiv ; 2023 Oct 04.
Article in English | MEDLINE | ID: mdl-37873150

ABSTRACT

Mitochondrial cristae architecture is crucial for optimal respiratory function of the organelle. Cristae shape is maintained in part by the mitochondrial inner membrane-localized MICOS complex. While MICOS is required for normal cristae morphology, the precise mechanistic role of each of the seven human MICOS subunits, and how the complex coordinates with other cristae shaping factors, has not been fully determined. Here, we examine the MICOS complex in Schizosaccharomyces pombe, a minimal model whose genome only encodes for four core subunits. Using an unbiased proteomics approach, we identify a poorly characterized inner mitochondrial membrane protein that interacts with MICOS and is required to maintain cristae morphology, which we name Mmc1. We demonstrate that Mmc1 works in concert with MICOS complexes to promote normal mitochondrial morphology and respiratory function. Bioinformatic analyses reveal that Mmc1 is a distant relative of the Dynamin-Related Protein (DRP) family of GTPases, which are well established to shape and remodel membranes. We find that, like DRPs, Mmc1 self-associates and forms high molecular weight assemblies. Interestingly, however, Mmc1 is a pseudoenzyme that lacks key residues required for GTP binding and hydrolysis, suggesting it does not dynamically remodel membranes. These data are consistent with a model in which Mmc1 stabilizes cristae architecture by acting as a scaffold to support cristae ultrastructure on the matrix side of the inner membrane. Our study reveals a new class of proteins that evolved early in fungal phylogeny and is required for the maintenance of cristae architecture. This highlights the possibility that functionally analogous proteins work with MICOS to establish cristae morphology in metazoans.

16.
J Glob Health ; 13: 06029, 2023 Oct 13.
Article in English | MEDLINE | ID: mdl-37824175

ABSTRACT

Background: Proficiency testing (PT) is a tool for ensuring the validity of results of testing laboratories and is essential when laboratories are working with assays authorised for emergency use or implementing novel techniques for detecting emerging pathogens. Methods: In collaboration with the National Health Institute of Colombia and with international support, we developed a qualitative PT for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcription polymerase chain reaction (RT-PCR). A proficiency test item (PTI) based on reference material (research grade) produced by the National Institute of Standards and Technologies (NIST) was prepared and characterised using three positive samples with varying concentrations of SARS-CoV-2 ribonucleic acid (RNA) and two negative (control) samples. Tests were distributed to 121 laboratories across the national network of public health laboratories in Colombia. Results: Positive samples had varying concentrations of SARS-CoV-2 RNA and were quantified by digital PCR (RT-ddPCR) assays for the E gene of SARS-CoV-2. We tested the ability of laboratories to detect low and high levels of viral RNA using samples with SARS-CoV-2 RNA concentrations of 1417 ± 216, 146 ± 28, and 14 ± 10 copies /uL (expanded uncertainty, k = 2, 95% confidence level) We also performed a semiquantitative analysis of instrumental responses (Ct values) reported by participating laboratories and homogeneity, stability, and characterisation studies of the produced materials to determine the adequacy of these materials and methods for use in the qualitative PT scheme. The PT evaluated reports for individual target genes from each laboratory; 98.3% of laboratories had satisfactory performance and the remaining 1.7% of laboratories had unsatisfactory performance for the detection of at least one of the reported genes. Conclusions: This PT scheme identified the potential metrological weaknesses of laboratories in the detection of SARS-CoV-2 by RT-PCR and may facilitate improvements in the quality of measurements from the perspective of public health surveillance.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , COVID-19 Testing , Clinical Laboratory Techniques/methods , RNA, Viral/analysis , RNA, Viral/genetics , Colombia , Polymerase Chain Reaction
17.
Int J Mol Sci ; 24(18)2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37762129

ABSTRACT

Autophagy, the process that enables the recycling and degradation of cellular components, is essential for homeostasis, which occurs in response to various types of stress. Autophagy plays an important role in the genesis and evolution of osteosarcoma (OS). The conventional treatment of OS has limitations and is not always effective at controlling the disease. Therefore, numerous researchers have analyzed how controlling autophagy could be used as a treatment or strategy to reverse resistance to therapy in OS. They highlight how the inhibition of autophagy improves the efficacy of chemotherapeutic treatments and how the promotion of autophagy could prove positive in OS therapy. The modulation of autophagy can also be directed against OS stem cells, improving treatment efficacy and preventing cancer recurrence. Despite promising findings, future studies are needed to elucidate the molecular mechanisms of autophagy and its relationship to OS, as well as the mechanisms underlying the functioning of autophagic modulators. Careful evaluation is required as autophagy modulation may have adverse effects on normal cells, and the optimization of autophagic modulators for use as drugs in OS is imperative.


Subject(s)
Bone Neoplasms , Drug-Related Side Effects and Adverse Reactions , Osteosarcoma , Humans , Autophagy , Osteosarcoma/drug therapy , Homeostasis , Bone Neoplasms/drug therapy
18.
Chaos ; 33(9)2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37729100

ABSTRACT

We consider a system of n coupled oscillators described by the Kuramoto model with the dynamics given by θ˙=ω+Kf(θ). In this system, an equilibrium solution θ∗ is considered stable when ω+Kf(θ∗)=0, and the Jacobian matrix Df(θ∗) has a simple eigenvalue of zero, indicating the presence of a direction in which the oscillators can adjust their phases. Additionally, the remaining eigenvalues of Df(θ∗) are negative, indicating stability in orthogonal directions. A crucial constraint imposed on the equilibrium solution is that |Γ(θ∗)|≤π, where |Γ(θ∗)| represents the length of the shortest arc on the unit circle that contains the equilibrium solution θ∗. We provide a proof that there exists a unique solution satisfying the aforementioned stability criteria. This analysis enhances our understanding of the stability and uniqueness of these solutions, offering valuable insights into the dynamics of coupled oscillators in this system.

19.
Int J Mol Sci ; 24(15)2023 Aug 03.
Article in English | MEDLINE | ID: mdl-37569779

ABSTRACT

Cellulose is produced industrially by the kraft and sulfite processes. The evolution of these technologies in biorefineries is driven by the need to obtain greater added value through the efficient use of raw materials and energy. In this field, organosolv technologies (and within them, those using liquid phases made up of water and one partly miscible organic solvent, known as "biphasic fractionation" in reference to the number of liquid phases) represent an alternative that is receiving increasing interest. This study considers basic aspects of the composition of lignocellulosic materials, describes the fundamentals of industrial cellulose pulp production processes, introduces the organosolv methods, and comprehensively reviews published results on organosolv fractionation based on the use of media containing water and an immiscible solvent (1-butanol, 1-pentanol or 2-methyltetrahydrofuran). Special attention is devoted to aspects related to cellulose recovery and fractionation selectivity, measured through the amount and composition of the treated solids.


Subject(s)
Cellulose , Lignin , Solvents , Water , Technology , Biomass
20.
Phys Rev E ; 107(6-1): 064304, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37464705

ABSTRACT

In some systems, the behavior of the constituent units can create a "context" that modifies the direct interactions among them. This mechanism of indirect modification inspired us to develop a minimal model of context-dependent spreading. In our model, agents actively impede (favor) or not diffusion during an interaction, depending on the behavior they observe among all the peers in the group within which that interaction occurs. We divide the population into two behavioral types and provide a mean-field theory to parametrize mixing patterns of arbitrary type-assortativity within groups of any size. As an application, we examine an epidemic-spreading model with context-dependent adoption of prophylactic tools such as face masks. By analyzing the distributions of groups' size and type-composition, we uncover a rich phenomenology for the basic reproduction number and the endemic state. We analytically show how changing the group organization of contacts can either facilitate or hinder epidemic spreading, eventually moving the system from the subcritical to the supercritical phase and vice versa, depending mainly on sociological factors, such as whether the prophylactic behavior is hardly or easily induced. More generally, our work provides a theoretical foundation to model higher-order contexts and analyze their dynamical implications, envisioning a broad theory of context-dependent interactions that would allow for a new systematic investigation of a variety of complex systems.


Subject(s)
Epidemics , Models, Theoretical
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