Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters











Publication year range
1.
Polymers (Basel) ; 15(15)2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37571167

ABSTRACT

The chemical recycling of poly(ethylene terephthalate) (PET) residues was performed via glycolysis with ethylene glycol (EG) over Mg-Fe and Mg-Al oxide catalysts derived from layered double hydroxides. Catalysts prepared using the high supersaturation method (h.s.c.) presented a higher surface area and larger particles, but this represented less PET conversion than those prepared by the low supersaturation method (l.s.c.). This difference was attributed to the smaller mass transfer limitations inside the (l.s.c.) catalysts. An artificial neural network model well fitted the PET conversion and bis(2-hydroxyethyl) terephthalate (BHET) yield. The influence of Fe in place of Al resulted in a higher PET conversion of the Mg-Fe-h.s.c. catalyst (~95.8%) than of Mg-Al-h.s.c. (~63%). Mg-Fe catalysts could be reused four to five times with final conversions of up to 97% with reaction conditions of EG: PET = 5:1 and catalyst: PET = 0.5%. These results confirm the Mg-Fe oxides as a biocompatible novel catalyst for the chemical recycling of PET residues to obtain non-toxic BHET for further polymerization, and use in food and beverage packaging.

2.
Life Sci ; 286: 120044, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34637792

ABSTRACT

AIM: To elucidate the mechanism behind the sustained high levels of phosphorylated eIF2α in HaCaT cells post-UVB. MAIN METHODS: In this study, expression levels of the machinery involved in the dephosphorylation of eIF2α (GADD34, CReP and PP1), as well as the PERK-eIF2α-ATF4-CHOP, IRE1α/XBP1s and ATF6α signaling cascades, were analyzed by western blot and fluorescence microscope. KEY FINDINGS: Our data showed that UVB induces the phosphorylation of eIF2α, which induces the translation of ATF4 and consequently the expression of CHOP and GADD34. Nevertheless, UVB also suppresses the translation of ATF4 and GADD34 in HaCaT cells via a p-eIF2α independent mechanism. Therefore, the lack of ATF4, GADD34 and CReP is responsible for the sustained phosphorylation of eIF2α. Finally, our data also showed that UVB selectively modifies PERK and downregulates ATF6α expression but does not induce activation of the IRE1α/XBP1s pathway in HaCaT cells. SIGNIFICANCE: Novel mechanism to explain the prolonged phosphorylation of eIF2α post-UVB irradiation.


Subject(s)
Eukaryotic Initiation Factor-2/metabolism , Keratinocytes/radiation effects , Activating Transcription Factor 4/metabolism , Cell Line , Endoribonucleases/metabolism , Gene Expression/genetics , Gene Expression Regulation/genetics , Humans , Keratinocytes/metabolism , Phosphorylation , Protein Biosynthesis , Protein Phosphatase 1/metabolism , Protein Serine-Threonine Kinases/metabolism , Signal Transduction/genetics , Transcription Factor CHOP/metabolism , Ultraviolet Rays/adverse effects , eIF-2 Kinase/metabolism
3.
Biotechnol Appl Biochem ; 68(5): 1044-1057, 2021 Oct.
Article in English | MEDLINE | ID: mdl-32931049

ABSTRACT

Biotechnology and bioengineering techniques have been widely used in the production of biofuels, chemicals, pharmaceuticals, and food additives, being considered a "green" form of production because they use renewable and nonpolluting energy sources. On the other hand, in the traditional processes of production, the target product obtained by biotechnological routes must undergo several stages of purification, which makes these processes more expensive. In the past few years, some works have focused on processes that integrate fermentation to the recovery and purification steps necessary to obtain the final product required. This type of process is called in situ product recovery or extractive fermentation. However, there are some differences in the concepts of the techniques used in these bioprocesses. In this way, this review sought to compile relevant content on considerations and procedures that are being used in this field, such as evaporation, liquid-liquid extraction, permeation, and adsorption techniques. Also, the objective of this review was to approach the different configurations in the recent literature of the processes employed and the main bioproducts obtained, which can be used in the food, pharmaceutical, chemical, and/or fuel additives industry. We intended to elucidate concepts of these techniques, considered very recent, but which emerge as a promising alternative for the integration of bioprocesses.


Subject(s)
Biotechnology , Adsorption , Biofuels , Fermentation , Liquid-Liquid Extraction
4.
J Periodontal Res ; 53(5): 924-931, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30043971

ABSTRACT

BACKGROUND: The aim of the present study is to evaluate the effect of orthodontic forces in healthy or diseased periodontium of rats submitted/not submitted to cigarette smoke inhalation. MATERIAL AND METHODS: Fifty-six male Wistar rats were allocated into two groups of conditions: smoking and non-smoking. Each group was divided into the following subgroups: control (C), orthodontic tooth movement (OTM), ligature-induced periodontitis (P) and P+OTM (POTM), with n = 14 each. Periodontitis was induced in the lower first molar by cotton ligature, and a 4 mm closed stainless steel spring was used for orthodontic movement. Animals were exposed to the smoke of 10 cigarettes for 8 minutes, 3 times a day for 60 days before P induction and OTM. Evaluation parameters were macroscopic analysis of dental movement, bone loss and bone density. In addition, the receptor activator of nuclear factor-kappaB (RANK) immunostaining and RANK ligand/osteoprotegerin ratio in the furcation region were assessed. RESULTS: There was no statistically significant difference between groups, ie, smoking and non-smoking conditions (P = .338). Bone loss intragroup analysis between the P and POTM groups was not significant in smoking (P = 1) and non-smoking (P = .5) conditions; both were different from OTM and C in each condition. Regarding bone density, POTM and P were significant to C (P < .05). The POTM group was significant to the P and C (P = .001) regarding dental movement. The RANK ligand/osteoprotegerin ratio in the non-smoking condition was higher in P and POTM compared to C and OTM and to P and POTM in the smoking condition. RANK immunostaining was significant in the smoking condition for the P and POTM groups (P < .05). CONCLUSION: Within the limitations of the present study, it was concluded that cigarette smoke inhalation had no influence on the evaluated groups, even with the presence of low levels of nicotine, carbon monoxide and tar. The POTM groups did not present greater bone loss compared to P groups, thus periodontal disease is essential for bone loss.


Subject(s)
Periodontitis/pathology , Periodontium/pathology , Smoking/adverse effects , Tooth Movement Techniques , Animals , Biomarkers/metabolism , Immunohistochemistry , Male , RANK Ligand/metabolism , Rats , Rats, Wistar , Receptor Activator of Nuclear Factor-kappa B/metabolism
5.
ABCD (São Paulo, Impr.) ; 24(2): 152-158, abr.-jun. 2011. ilus, tab
Article in Portuguese | LILACS | ID: lil-592485

ABSTRACT

RADICAL: Injúria renal aguda é uma das complicações mais comuns do transplante ortotópico de fígado. A ausência de critério universal para sua definição nestas condições dificulta as comparações entre os estudos. A técnica convencional para o transplante consiste na excisão total da veia cava inferior retro-hepática durante a hepatectomia nativa. Controvérsias sobre o efeito da técnica convencional sem desvio venovenoso na função renal continuam. OBJETIVO: Estimar a incidência e os fatores de risco de injúria renal aguda entre os receptores de transplante ortotópico de fígado convencional sem desvio venovenoso. MÉTODOS: Foram avaliados 375 pacientes submetidos a transplante ortotópico de fígado. Foram analisadas as variáveis pré, intra e pós-operatórias em 153 pacientes submetidos a transplante ortotópico de fígado convencional sem desvio venovenoso. O critério para a injúria renal aguda foi valor da creatinina sérica > 1,5 mg/dl ou débito urinário < 500 ml/24h dentro dos primeiros três dias pós-transplante. Foi realizada análise univariada e multivariada por regressão logística. RESULTADOS: Todos os transplantes foram realizados com enxerto de doador falecido. Sessenta pacientes (39,2 por cento) apresentaram injúria renal aguda. Idade, índice de massa corpórea, escore de Child-Turcotte-Pugh, ureia, hipertensão arterial sistêmica e creatinina sérica pré-operatória apresentaram maiores valores no grupo injúria renal aguda. Durante o período intraoperatório, o grupo injúria renal aguda apresentou mais síndrome de reperfusão, transfusão de concentrado de hemácias, plasma fresco e plaquetas. No pós-operatório, o tempo de permanência em ventilação mecânica e creatinina pós-operatória também foram variáveis, com diferenças significativas para o grupo injúria renal aguda. Após regressão logística, a síndrome de reperfusão, a classe C do Child-Turcotte-Pugh e a creatinina sérica pós-operatória apresentaram diferenças. CONCLUSÃO: Injúria renal aguda após...


BACKGROUND: Acute kidney injury is one of the most common complications of orthotopic liver transplantation. The absence of universal criteria for definition of these conditions make comparisons difficult between studies. The conventional technique for transplantation is the total excision of the inferior vena cava during liver retro-native hepatectomy. Controversies about the effect of the conventional technique without venovenous bypass on renal function remain. AIM: To estimate the incidence and risk of acute kidney injury factors among recipients of orthotopic liver transplantation without conventional venovenous bypass. METHODS: Was studied 375 patients undergoing orthotopic liver transplantation. Variables were analyzed in preoperative, intraoperative and postoperative complications in 153 patients undergoing orthotopic liver transplantation without conventional venovenous bypass. The criterion for acute kidney injury was serum creatinine > 1.5 mg/dl or urinary debit <500 ml/24h within the first three days post-transplant. Univariate analysis and multivariate logistic regression were done. RESULTS: All transplants were performed with grafts from deceased donors. Sixty patients (39.2 percent) had acute kidney injury. Age, body mass index, Child-Turcotte-Pugh, urea, hypertension, and preoperative serum creatinine were higher in the acute kidney injury group. During the intraoperative period, the group acute kidney injury had more reperfusion syndrome, transfusion of red blood cells, fresh frozen plasma and platelets. Postoperatively, the duration of mechanical ventilation and postoperative creatinine levels were also variable, with significant differences for the group of acute kidney injury. After logistic regression, the reperfusion syndrome, the class C of the Child-Turcotte-Pugh and postoperative serum creatinine showed differences. CONCLUSION: Acute kidney injury after orthotopic liver transplantation without conventional venovenous bypass is...


Subject(s)
Humans , Ischemia/complications , Acute Kidney Injury , Kidney Diseases/complications , Liver Transplantation/mortality , Risk Factors
6.
Autoimmunity ; 43(4): 288-98, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20166880

ABSTRACT

Interleukin (IL)-15 and CD30 may be associated with the ongoing intestinal immunologic activation in celiac disease (CD). We studied duodenal biopsies and blood samples of patients with active CD (Cel) and controls in order to determine the regulatory role proposed for CD30(+) T cells in this Th1-driven disease and the potential influences of IL-15 on CD30 expression. We detected that a CD30(+) T-cell subpopulation persists longer in Cel after a 5 day incubation with anti-CD3 antibody than in controls (p = 0.0063). CD30 upregulation by IL-15 in T blasts was greater in Cel than in controls (p = 0.0062). At the mucosal compartment, the CD30 antigen was examined by immunohistochemistry and quantified on isolated lamina propria (LP) and epithelial T cells by flow cytometry. For Cel and controls, similar mean percentages of CD3(+)CD30(+) intraepithelial T cells (5.88 vs. 5.51, p = ns) and LP T cells (7.38 vs. 7.49, p = ns) were observed at baseline and after in vitro gliadin challenge of duodenal biopsy samples. Our study demonstrates the occurrence of potentially important alterations of the immune response at the peripheral compartment. Our findings also allow us to speculate that a negative effect of soluble mediators at the mucosal compartment might counteract the latent influence of IL-15 on CD30 expression precluding a more severe course of active CD.


Subject(s)
Celiac Disease/immunology , Celiac Disease/pathology , Gene Expression Regulation , Interleukin-15/metabolism , Ki-1 Antigen/metabolism , Adult , Aged , Biopsy , Celiac Disease/metabolism , Duodenum/immunology , Duodenum/metabolism , Female , Humans , Interleukin-15/genetics , Intestinal Mucosa/cytology , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Ki-1 Antigen/genetics , Lymphocyte Activation , Male , Middle Aged , T-Lymphocytes/immunology , Young Adult
7.
Tech Coloproctol ; 13(4): 315-6, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19652908

ABSTRACT

A 43-year-old woman with a postoperative low-output colocutaneous fistula in her lower abdomen was successfully treated under endoscopic control, employing the Surgisis anal plug, a cone-shaped medical device that has been formerly designed to be easily positioned into an anal fistula. We describe the technique employed here which to our knowledge, has never been described in medical literature.


Subject(s)
Cecal Diseases/surgery , Cutaneous Fistula/surgery , Intestinal Fistula/surgery , Adult , Cesarean Section , Colonoscopy , Endoscopy, Gastrointestinal , Female , Humans , Prostheses and Implants , Surgical Sponges , Surgical Wound Infection/surgery
8.
Rev Inst Med Trop Sao Paulo ; 47(2): 117-8, 2005.
Article in English | MEDLINE | ID: mdl-15880227

ABSTRACT

The aim of the present study was to investigate the detection percentage of tuberculosis among patients that are respiratory symptomatic (TB suspects). In this work, we present the preliminary results of research carried out at "Hospital das Clínicas de Teresópolis Costantino Ottaviano da Fundacao Educacional Serra dos Orgãos (FESO)" from November 2003 to April 2004. Among the 40 respiratory symptomatic individuals identified and referred to the Tuberculosis Control Program in Teresópolis , two (5.0%) were characterized as smear-positive. These results confirm reports in the literature and underscore the need for and importance of this strategy.


Subject(s)
Mass Screening/methods , Tuberculosis, Pulmonary/diagnosis , Brazil , Emergency Service, Hospital , Female , Humans , Male , Sputum/microbiology
9.
Rev. Inst. Med. Trop. Säo Paulo ; Rev. Inst. Med. Trop. Säo Paulo;47(2): 117-118, Mar.-Apr. 2005.
Article in English | LILACS | ID: lil-399957

ABSTRACT

Investigar o percentual de detecção de tuberculose entre sintomáticos respiratórios é o objetivo do presente estudo. Nesta nota prévia, apresentam-se os resultados preliminares da pesquisa desenvolvida no Hospital das Clinicas de Teresópolis Costantino Ottaviano da Fundação Educacional Serra dos Orgãos (FESO), de novembro de 2003 a abril de 2004. Dos 40 sintomáticos respiratórios identificados e encaminhados ao Programa de Controle da Tuberculose do município de Teresópolis, dois (5.0%) foram caracterizados como bacilíferos. Esses resultados corroboram com os relatos da literatura e confirmam a necessidade e importância desta estratégia.


Subject(s)
Humans , Male , Female , Emergency Service, Hospital , Mass Screening/methods , Tuberculosis, Pulmonary/diagnosis , Brazil , Sputum/microbiology
10.
Buenos Aires; Médica Panamericana; 18a ed.; 1986. 1454 p.
Monography in Spanish | URUGUAIODONTO | ID: odn-1819

Subject(s)
Microbiology
SELECTION OF CITATIONS
SEARCH DETAIL