THE SELF-CONDENSATION REACTION OF METHYL-4-CHLOROACETIL-                      ACETATE IN THE PRESENCE OF POTASSIUM CARBONATE

AbstractThe condensation reaction of lignin is believed to interfere with delignification in alkaline pulping processes, without any clear evidence, which has motivated us to quantitatively revisit it. This paper is the first of a series, and hence we employed the simplest model system using 4-hydroxymethyl-2-methoxyphenol (vanillyl alcohol, Va) and 2-methoxy-4-methylphenol (creosol, Cr) under soda cooking conditions. The α-5-type condensation product between these compounds [VaCr, 2-(4-hydroxy-3-methoxybenzyl)-6-methoxy-4-methylphenol] was identified and quantified as exclusive. VaCr was yielded with a mole amount of 24%, 46%, 62%, or 72% based on that of disappearing Va at a reaction time of 120 min when the ratio of the initial concentration of Cr to that of Va was 1.0, 2.5, 5.0, or 7.5, respectively. These yields and an HPLC analysis of the reaction solution obtained by a treatment of Va as the sole compound under the same soda cooking conditions suggested the formation of self-condensation products of Va even in the treatments containing Cr. The obtained results comprehensively suggested that the self-condensation of Va progresses more readily than the condensation between Va and Cr. The factors behind this will be the topic of our next paper.

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Lignin Utilization I. Kinetics of Base-Catalyzed Condensation Reactions of Lignin Model Compounds

Canadian Journal of Forest Research ◽

10.1139/x72-044 ◽

1972 ◽

Vol 2 (3) ◽

pp. 271-275 ◽

Cited By ~ 1

Author(s):

G. E. Troughton ◽

J. F. Manville

Keyword(s):

Condensation Reaction ◽

Activation Energies ◽

The Self ◽

Model Compounds ◽

Lignin Model Compounds ◽

Temperature Range ◽

Condensation Reactions ◽

Lignin Model ◽

Lignin Utilization ◽

Kinetics Of

Rates of formation were measured for the base-catalyzed condensation reactions occurring between 4-alkylguaiacol compounds and their 6-methylol derivatives over the temperature range 85.5–100 °C. It was found that both the intercondensation reaction between the 4-alkylguaiacol compound and its 6-methylol derivative and the self-condensation reaction of the latter compound occurred at significant rates. In the 4-propylguaiacol – 4-methyl-6-methylolguaiacol system, the above two condensation reactions occurring in this system had the same activation energies, 35 kcal/mol. Similarly, in the 4-methylguaiacol – 4-propyl-6-methylolguaiacol system these two condensation reactions had equivalent activation energies, but slightly lower than in the former system, 32 kcal/mol. The kinetic results found for the model guaiacol compounds in this study demonstrate the possibility that a lignin-derived compound having more than one reactive position can be developed into a phenolic-type resin.

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Study of the Catalytic Activity of the Compounds Hydrotalcite Type Treated by Microwave in the Self-Condensation of Acetone

International Journal of Analytical Chemistry ◽

10.1155/2021/1551586 ◽

2021 ◽

Vol 2021 ◽

pp. 1-7

Author(s):

Jamal Houssaini ◽

Mohammed Naciri Bennani ◽

Hamid Ziyat ◽

Said Arhzaf ◽

O. Qabaqous ◽

...

Keyword(s):

Catalytic Activity ◽

Condensation Reaction ◽

Catalyst Activity ◽

The Self ◽

Conventional Heating ◽

Molar Ratio ◽

High Catalytic Activity ◽

Adsorption Method ◽

X Ray ◽

Diacetone Alcohol

The self-condensation reaction of acetone, producing diacetone alcohol (DAA), is of great industrial importance. It was used to study the catalytic activity of Mg-Al catalysts synthesized by the coprecipitation method. For this purpose, we synthesized Mg-Al based hydrotalcite with a molar ratio of 3, obtained either after conventional heating or after microwave irradiation with of 100 W for three minutes. Structural and chemical properties of the obtained catalysts were characterized, using different techniques: X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), equipped with energy dispersive X-ray (EDX), and specific surface area of the catalysts were determined by the methylene blue (MB) adsorption method. Also, these catalysts were tested in the self-condensation reaction of acetone at 273 K in the liquid phase without solvent, a reaction which requires very high catalytic activity. The microwave treatment improves the catalyst activity, and the conversion of acetone to diacetone alcohol increases from 13.2 to 18.3% after 8 h of reaction. Moreover, the microwave-treated hydrotalcite catalyst, calcined at 723 K and rehydrated under a flow of N2, is the most active and gives conversion of acetone of 52% under the same reaction conditions.

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Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

Behavioral and Brain Sciences ◽

10.1017/s0140525x18001188 ◽

2019 ◽

Vol 42 ◽

Author(s):

Lucio Tonello ◽

Luca Giacobbi ◽

Alberto Pettenon ◽

Alessandro Scuotto ◽

Massimo Cocchi ◽

...

Keyword(s):

Autism Spectrum Disorder ◽

Problem Behaviors ◽

Autism Spectrum ◽

The Self ◽

Network Structures ◽

Self Organized ◽

Critical Equilibrium ◽

Self Organized Criticality ◽

Acute Agitation ◽

Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

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The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065870 ◽

1971 ◽

Vol 29 ◽

pp. 366-367

Author(s):

M. Kessel ◽

R. MacColl

Keyword(s):

Self Assembly ◽

Analytical Ultracentrifugation ◽

Uranyl Acetate ◽

The Self ◽

Major Protein ◽

Subunit Structure ◽

Blue Green Alga ◽

Thin Sections ◽

Blue Green Algae ◽

Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

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Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100123969 ◽

1992 ◽

Vol 50 (1) ◽

pp. 712-713

Author(s):

Xiaorong Zhu ◽

Richard McVeigh ◽

Bijan K. Ghosh

Keyword(s):

Alkaline Phosphatase ◽

Bacillus Licheniformis ◽

Self Assembly ◽

Gel Electrophoresis ◽

Culture Supernatant ◽

Regular Structure ◽

The Self ◽

Cellular Distribution ◽

Structural Protein ◽

Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

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Self-Compassion and Quality of Life in Adults Who Stutter

American Journal of Speech-Language Pathology ◽

10.1044/2020_ajslp-20-00055 ◽

2020 ◽

Vol 29 (4) ◽

pp. 2097-2108

Author(s):

Robyn L. Croft ◽

Courtney T. Byrd

Keyword(s):

Quality Of Life ◽

Social Connectedness ◽

The Self ◽

Future Research ◽

Self Compassion ◽

Adults Who Stutter ◽

And Gender ◽

Relationship Of ◽

The Impact

Purpose The purpose of this study was to identify levels of self-compassion in adults who do and do not stutter and to determine whether self-compassion predicts the impact of stuttering on quality of life in adults who stutter. Method Participants included 140 adults who do and do not stutter matched for age and gender. All participants completed the Self-Compassion Scale. Adults who stutter also completed the Overall Assessment of the Speaker's Experience of Stuttering. Data were analyzed for self-compassion differences between and within adults who do and do not stutter and to predict self-compassion on quality of life in adults who stutter. Results Adults who do and do not stutter exhibited no significant differences in total self-compassion, regardless of participant gender. A simple linear regression of the total self-compassion score and total Overall Assessment of the Speaker's Experience of Stuttering score showed a significant, negative linear relationship of self-compassion predicting the impact of stuttering on quality of life. Conclusions Data suggest that higher levels of self-kindness, mindfulness, and social connectedness (i.e., self-compassion) are related to reduced negative reactions to stuttering, an increased participation in daily communication situations, and an improved overall quality of life. Future research should replicate current findings and identify moderators of the self-compassion–quality of life relationship.

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AAC Collaboration Using the Self-Anchored Rating Scales (SARS): An Aphasia Case Study

Perspectives on Augmentative and Alternative Communication ◽

10.1044/aac21.4.136 ◽

2012 ◽

Vol 21 (4) ◽

pp. 136-143

Author(s):

Lynn E. Fox

Keyword(s):

Augmentative And Alternative Communication ◽

Rating Scales ◽

Rating Scale ◽

Therapeutic Process ◽

Family Counseling ◽

The Self ◽

Alternative Communication ◽

Her Family ◽

Solution Focused

Abstract The self-anchored rating scale (SARS) is a technique that augments collaboration between Augmentative and Alternative Communication (AAC) interventionists, their clients, and their clients' support networks. SARS is a technique used in Solution-Focused Brief Therapy, a branch of systemic family counseling. It has been applied to treating speech and language disorders across the life span, and recent case studies show it has promise for promoting adoption and long-term use of high and low tech AAC. I will describe 2 key principles of solution-focused therapy and present 7 steps in the SARS process that illustrate how clinicians can use the SARS to involve a person with aphasia and his or her family in all aspects of the therapeutic process. I will use a case study to illustrate the SARS process and present outcomes for one individual living with aphasia.

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