Claudia Vidal - Academia.edu (original) (raw)

Papers by Claudia Vidal

Polymers

Bleached kraft pulps from eucalyptus and pine were subjected to cold caustic extraction (CCE) wit... more Bleached kraft pulps from eucalyptus and pine were subjected to cold caustic extraction (CCE) with NaOH (5, 10, 17.5, and 35%) for hemicelluloses removal and to increase cellulose accessibility. The effect of these changes was evaluated in enzymatic saccharification with the multicomponent Cellic CTec3 enzyme cocktail, and in viscosity reduction of pulps with the monocomponent Trichoderma reesei endoglucanase (EG). After CCE with 10% NaOH (CCE10) and 17.5% NaOH (CCE17.5), hemicellulose content lower than 1% was achieved in eucalyptus and pine pulps, respectively. At these concentrations, cellulose I started to be converted into cellulose II. NaOH concentrations higher than 17.5% decreased the intrinsic viscosity (from 730 to 420 mL/g in eucalyptus and from 510 to 410 mL/g in pine). Cellulose crystallinity was reduced from 60% to 44% in eucalyptus and from 71% to 44% in pine, as the NaOH concentration increased. Enzymatic multicomponent saccharification showed higher glucose yields i...

2º Congreso Internacional Ciudad y Territorio Virtual, Concepción, Chile, 12, 13 y 14 Octubre 2005

The process of urbanisation of the city Concepción, has historically been affected by the charact... more The process of urbanisation of the city Concepción, has historically been affected by the characteristics of his natural environment, in origin, evolution and development. The city in its evolution hasprovoked important modifications of the natural landscape. In the study, is presented the application of geographic information systems and digital graphic tools to sudy the interaction between geographics characteristics and the city. Since 1752 to 2000. For that, it was digitalised and rebuilded through SIG and COREL. The most importants plans that has ruled the urban development of Concepción.

4º Congreso Internacional Ciudad y Territorio Virtual, Guadalajara-Jalisco, México, 1-5 Octubre 2007

Arquitecturas del Sur, 2015

El crecimiento demografico mundial, la tendencia historica de la poblacion a concentrarse en las ... more El crecimiento demografico mundial, la tendencia historica de la poblacion a concentrarse en las ciudades y la expansion en forma horizontal y desordenada de la planta fisica de las urbes, sin considerar la capacidad de acogida del territorio, origina la ocupacion de areas poco aptas desde el punto de vista de los riesgos. De igual modo, las ciudades generan drasticas modificaciones en el sistema natural, tales como relleno de quebradas, paleocanales y trabajos de nivelacion; eliminacion de areas verdes que ofrecen servicios ambientales y cumplen un importante rol ecologico y recreacional; modificacion y disminucion de la cobertura vegetal y de la capacidad de infiltracion del agua e incremento de la erosion del suelo. Por otro lado, la impermeabilizacion de los suelos, aumenta la escorrentia superficial y con ello el poder erosivo de las aguas y la perdida de la capa vegetal. Finalmente, la intervencion en cuencas hidrograficas y laderas de cerro. Todo ello contribuye a incrementar...

Sustainability, 2021

Lignin is one of the wood and plant cell wall components that is available in large quantities in... more Lignin is one of the wood and plant cell wall components that is available in large quantities in nature. Its polyphenolic chemical structure has been of interest for valorization and industrial application studies. Lignin can be obtained from wood by various delignification chemical processes, which give it a structure and specific properties that will depend on the plant species. Due to the versatility and chemical diversity of lignin, the chemical industry has focused on its use as a viable alternative of renewable raw material for the synthesis of new and sustainable biomaterials. However, its structure is complex and difficult to characterize, presenting some obstacles to be integrated into mixtures for the development of polymers, fibers, and other materials. The objective of this review is to present a background of the structure, biosynthesis, and the main mechanisms of lignin recovery from chemical processes (sulfite and kraft) and sulfur-free processes (organosolv) and des...

Biomass Conversion and Biorefinery, 2020

Several agricultural wastes, such as the residues of the winemaking industry, have been tested us... more Several agricultural wastes, such as the residues of the winemaking industry, have been tested using traditional chemical methods of pulping aimed to obtain bleached pulp, but only low yields and poor fiber quality have been achieved so far. In this work, we evaluate a two-stage chemi-thermomechanical pulping (CTMP) to assess the feasibility to add value to the residues of the wine industry (grape stalks and vine shoots) by obtaining fibers with papermaking and/or cardboard quality. The first stage of the process evaluates different conditions with low chemical charges of Na 2 SO 3 and/or NaOH (3 to 5% on wood basis) at different temperatures (130 to 160°C) for 60 min. The second stage consists of a mechanical refining that converts fiber bundles and shives into pulps. CTMP pulping performed with 5% Na 2 SO 3 at 160°C from grape stalks and vine shoots showed the best combination of fiber quality regarding higher screened pulp yield, lower rejects and fines content, and adequate drainability. Results showed that pulp from waste lignocellulosic of the winery industry can be produced by a green approach (low chemical charge and severity in CTMP pulping) and became an alternative for paper, packaging, fiber additives, or new biobased materials.

Journal of Plastic, Reconstructive & Aesthetic Surgery, 2020

Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on ... more Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre-including this research content-immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.

Powder Technology, 2019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

The American Journal of Dermatopathology, 2019

International journal of trichology

Telogen effluvium (TE) is a type of acquired, diffuse alopecia that occurs due to an abnormal shi... more Telogen effluvium (TE) is a type of acquired, diffuse alopecia that occurs due to an abnormal shift of scalp hair follicles from anagen to telogen, leading to premature shedding of hair. Previous studies have suggested the existence of a neuroimmunologic "brain-hair follicle" axis, in which mast cells have been implicated as an important link between the nervous system and immunologic system. The current study sought to investigate the role of mast cell presence and mast cell degranulation in the pathogenesis of TE. Mast cells were counted using Giemsa and tryptase immunohistochemical stains in scalp biopsy specimens with the pathologic diagnosis of TE (TE, n = 10), alopecia areata (AA, n = 7), and androgenic alopecia (ANDRO, n = 9). We found significant (P < 0.001) group-level differences between the mean mast cell counts per high-power fields for each type of alopecia studied. Tukey post hoc analysis showed the mean mast cell count for TE to be significantly larger th...

International journal of antimicrobial agents, May 14, 2017

Ciprofloxacin-resistant and extended-spectrum β-lactamase-producing Escherichia coli ST410 strain... more Ciprofloxacin-resistant and extended-spectrum β-lactamase-producing Escherichia coli ST410 strain carrying the mcr-1 gene associated with bloodstream infection,

Dermatologic Surgery, 2017

Cellular neurothekeoma is a rare, benign soft tissue neoplasm with a risk of local recurrence. It... more Cellular neurothekeoma is a rare, benign soft tissue neoplasm with a risk of local recurrence. It presents a challenge to diagnose because of its histologic similarities to other dermal tumors including plexiform fibrohistiocytic tumor. This distinction is important because each of these tumors has a different behavior pattern and risk of recurrence and distant metastasis. In addition, it can be difficult to obtain clear surgical margins especially in the setting of incomplete resection or recurrence because of its similarity to scar tissue on routine pathologic staining, often necessitating specialized staining techniques (Table 1). To reduce recurrence, it is important to obtain accurate tumor resection margins, especially before proceeding with definitive facial reconstruction as methods of tissue rearrangement will distort the original tumor bed. We present a case of cellular neurothekeoma of the lip in a pediatric patient with the challenges of diagnostic accuracy, tumor clearance, and reconstruction which was successfully treated by a multidisciplinary approach using a novel “modified” slow Mohs technique.

The Journal of craniofacial surgery, 2016

Nasomaxillary dysplasia (Binder syndrome) and cleft are congenital malformations of the midface. ... more Nasomaxillary dysplasia (Binder syndrome) and cleft are congenital malformations of the midface. Ideally, the nasal deformity is treated from childhood. This approach leads to the need for several surgeries and revisions until full growth is reached. As a result of multiples procedures, the skin over the nasal dorsum sometimes becomes thin, atrophic and could be strongly attached to underlying grafts. For this setting of patients when another rhinoplasty is required, it becomes a technical challenge. The authors describe their experience in complex secondary rhinoplasty performed in patients with thin atrophic skin using the anteriorly based galeo-pericranial frontalis flap (GPFF) to improve the quality of the covering soft tissue along the whole nose skeleton area. Since 2013, 3 female patients; 2 of them with Binder syndrome and 1 cleft lip/palate patient (average 18 years) with previous rhinoplasty (3-6 procedures) are subjected to secondary rhinoplasty using GPFF turning it over...

BioResources, 2016

Conditions to increase phenolic hydroxyl groups (OH-Phe) in organosolv lignin using alkaline cata... more Conditions to increase phenolic hydroxyl groups (OH-Phe) in organosolv lignin using alkaline catalysts (NaOH and KOH) were optimized with the purpose of increasing the reactivity of lignin and to evaluate the effect on the structure of the newly generated compounds as a result of the basecatalyzed depolymerization (BCD). The lignin-derived compounds could be used for the synthesis of bio-based polymers and nanomaterials. The maximal yield of OH-Phe reached values of 5270 and 3970 μmol per gram of lignin when NaOH (8.6%, 173 °C, and 33 min) and KOH (11.7%, 174 °C, and 58 min), defined as optimal conditions for BCD, were used, respectively, while for the control lignin, OH-Phe was 2830 μmol per gram of lignin. The molecular weight (Mw) and glass transition temperature (Tg) for lignin-NaOH were lower than those of lignin-KOH and lignin-control. Both lignin derivatives had greater thermal stability at high temperatures than lignin-control. In conclusion, the results showed higher modifications in the structure of lignin as a result of the oxidation process, primarily by cleavage of the β-O-4 ether bond and variations in thermochemical properties when NaOH is used as alkaline catalyst.

Revista Latino-Americana de Enfermagem, 2015

Objective: to validate the content of the prevention protocol for early sepsis caused by Streptoc... more Objective: to validate the content of the prevention protocol for early sepsis caused by Streptococcus agalactiaein newborns.Method: a transversal, descriptive and methodological study, with a quantitative approach. The sample was composed of 15 judges, 8 obstetricians and 7 pediatricians. The validation occurred through the assessment of the content of the protocol by the judges that received the instrument for data collection - checklist - which contained 7 items that represent the requisites to be met by the protocol. The validation of the content was achieved by applying the Content Validity Index.Result: in the judging process, all the items that represented requirements considered by the protocol obtained concordance within the established level (Content Validity Index > 0.75). Of 7 items, 6 have obtained full concordance (Content Validity Index 1.0) and the feasibility item obtained a Content Validity Index of 0.93. The global assessment of the instruments obtained a Conte...

The American Journal of dermatopathology, Jan 19, 2014

Mammary analog secretory carcinoma (MASC) is a rare type of salivary gland tumor named for its mo... more Mammary analog secretory carcinoma (MASC) is a rare type of salivary gland tumor named for its morphological and genetic similarity to secretory carcinoma of the breast. These tumors are most often found in the parotid gland but have been described in several other mucosal locations of the head and neck. In this case report, a cutaneous lesion most closely resembling MASC was found in a neck mass of a 64-year-old male patient without evidence of a primary salivary gland or oral tumor. The lesion was excised, and the patient remains disease free to date. This case depicts a rare tumor in the skin most closely mimicking MASC and brings additional awareness to dermatopathologists of this tumor.

Case Reports in Medicine, 2009

Kimuras disease is a chronic inflammatory disorder of unknown etiology. It is rare in the West, b... more Kimuras disease is a chronic inflammatory disorder of unknown etiology. It is rare in the West, but endemic in Asia. It typically presents as solitary or multiple subcutaneous nodules, that slowly increase in size. The lesions are variably painful and pruritic. It often accompanied by regional lymphadenopathy, raised serum eosinophil counts, and markedly elevated serum immunoglobulin E levels. Histologically, the lesions are characterized by reactive lymphoid follicles with eosinophilic infiltration and an increased amount of postcapillary venules. The optimal treatment for KD remains controversial. Although the condition seldom resolves spontaneously, malignant transformation has not been reported to date, and the prognosis is good. We describe a male patient with a 4-year pruritic progressive “bump” in front of his left ear. On physical examination, the patient had 2 discrete lesions on the left side of his face near his ear. Postauricularly, there was a3×5cm erythematous to viola...

Infectious Diseases in Clinical Practice, 2011

... A Potentially Benign Form of Cutaneous Zygomycosis Infection Claudia I. Vidal, MD, PhD,*Rebec... more ... A Potentially Benign Form of Cutaneous Zygomycosis Infection Claudia I. Vidal, MD, PhD,*Rebecca Kleinerman, MD,þ Yoon Chul Shin,* Jacob Levitt, MD,þ Robert G. Phelps, MD,Þþ and Miriam B. Birgé, MDÞ ... 5. Arnaiz-Garcia ME, Pena DA, del Carmen Gonzalez-Vela M, et al. ...

EURE (Santiago), 2001

Concepción city, situated at the central south of Chile, is an urban center that in the course of... more Concepción city, situated at the central south of Chile, is an urban center that in the course of his history has been affected frequently by naturals risks. In this article, we have separated and evaluated the areas exposed at risks: seismic; of overflowing; of fluvial inundation and removal in mass. For that objective we have adapted the methodology of aggregation of charts of risks factors: danger, vulnerability and exposition, proposed by the NU. As a result we obtained a natural risks letter and we suggest it is application in the preparation of plans and programs prevention and natural risks correction and also in the programs organization of emergencies administration.