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1.
Bioresour Technol ; 386: 129552, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37499927

RESUMO

Lignocellulosic biomass (LCB) is the promising feedstock for value-added products, which would contribute to the bioeconomy and sustainable development. The efficient pretreatment is still required in the biorefinery of LCB. To make a simultaneous utilization of carbohydrates and lignin, a novel easy-recycled ethylenediamine (EDA) pretreatment was designed and evaluated in the present study. The results highlighted that this pretreatment yielded 96% glucose and 70% xylose in enzymatic hydrolysis. It simultaneously promoted the depolymerization of lignin into small molecules and functionalized the yielded lignin with Schiff base and amide structures. These animated-lignins showed a pH-responsive behavior and the excellent flocculation capacity by reducing more than 90% turbidity of kaolin suspensions. Therefore, easy-recycled EDA pretreatment hold the promise to simultaneously enhance the enzymatic hydrolysis of carbohydrates and endowed the new functionality of lignin toward downstream valorization, which improved the process feasibility and potentially enable the sustainability of LCB utilization.


Assuntos
Carboidratos , Lignina , Lignina/química , Hidrólise , Glucose/química , Biomassa , Etilenodiaminas
2.
ChemSusChem ; 15(21): e202201284, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36094056

RESUMO

Lignin-based activated carbon (LAC) is a promising high-quality functional material due to high surface area, abundant porous structure, and various functional groups. Modification is the most important step to functionalize LAC by altering its porous and chemical properties. This Review summarizes the state-of-the-art modification technologies of LAC toward advanced applications. Promising modification approaches are reviewed to display their effects on the preparation of LAC. The multiscale changes in the porosity and the surface chemistry of LAC are fully discussed. Advanced applications are then introduced to show the potential of LAC for supercapacitor electrode, catalyst support, hydrogen storage, and carbon dioxide capture. Finally, the mechanistic structure-function relationships of LAC are elaborated. These results highlight that modification technologies play a special role in altering the properties and defining the functionalities of LAC, which could be a promising porous carbon material toward industrial applications.


Assuntos
Carvão Vegetal , Lignina , Lignina/química , Porosidade , Eletrodos , Dióxido de Carbono/química
3.
Beijing Da Xue Xue Bao Yi Xue Ban ; 47(4): 685-9, 2015 Aug 18.
Artigo em Chinês | MEDLINE | ID: mdl-26284410

RESUMO

OBJECTIVE: To evaluate the influence of dexamethasone on the incidence of postoperative nausea and vomiting (PONV) in patients undergoing modified radical mastectomy with neoadjuvant chemotherapy. METHODS: In a prospective trial, 280 female (18-60 years) breast cancer patients undergoing modified radical mastectomy with neoadjuvent chemotherapy were randomized to two groups: one with dexamethasone (Group D) and one without dexamethasone (Group C, n=140). In each group, anesthesia was maintained with volatile anesthesia or total intravenous anesthesia (TIVA): TIVA (propofol) without dexamethasone (Subgroup CP); volatile anesthesia (sevoflurane) without dexamethasone (Subgroup CS); TIVA with 10 mg dexamethasone intravenously before anesthetic induction (Subgroup DP); volatile anesthesia with 10 mg dexamethasone intravenously before anesthetic induction (Subgroup DS). A standard general anesthetic technique was used. All the patients received 8 mg of ondansetron intravenously 30 minutes before the end of surgical procedures. The incidence of PONV during the 24-hour postoperative period was recorded. A Logistic regression analysis was conducted to examine relevant factors for PONV. The tested factors were: age, body mass index (BMI), duration of surgery, postoperative pain, history of motion sickness/PONV, with or without dexamethasone and anesthetic regimen. RESULTS: There was a significant lower incidence of PONV in the patients who received dexamethasone than in those who received placebo during the 24-hour postoperative period (11.4% vs. 20.7%, P=0.034). In the early postoperative period (0-2 h) dexamethasone reduced the incidence of PONV ( 1.4%vs.6.4%, P=0.031), but in the late postoperative period (2-24 h) the difference of the incidence was insignificantly (10.7% vs. 17.9%, P=0.088). No differences were found between TIVA and volatile anesthesia in the 24-hour postoperative period. Dexamethasone was effective to prevent PONV(OR=0.447, P=0.030), and history of PONV or motion sickness was the risk factor of PONV (OR=15.730, P<0.001). CONCLUSION: Dexamethasone prevents PONV effectively in patients undergoing modified radical mastectomy with neoadjuvant chemotherapy, and TIVA cannot decrease the incidence of PONV in the 24-hour postoperative period in those patients.


Assuntos
Antieméticos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Dexametasona/uso terapêutico , Terapia Neoadjuvante , Náusea e Vômito Pós-Operatórios/prevenção & controle , Adolescente , Adulto , Anestesia Geral , Anestesia Intravenosa , Anestésicos Intravenosos , Método Duplo-Cego , Feminino , Humanos , Incidência , Éteres Metílicos , Pessoa de Meia-Idade , Ondansetron , Dor Pós-Operatória , Propofol , Estudos Prospectivos , Sevoflurano , Adulto Jovem
4.
Chin Med J (Engl) ; 124(4): 504-8, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21362271

RESUMO

BACKGROUND: In recent years, increasing numbers of patients are accepting neoadjuvant chemotherapy before their operation in order to get a better prognosis. But chemotherapy has many side-effects. We have observed that patients who accepted neoadjuvant chemotherapy are more sensitive to anesthetics. The aim of this study was to determine the median effective dose (EC(50)) of intravenous anesthetics for neoadjuvant chemotherapy patients to lose consciousness during target-controlled infusion. METHODS: Two hundred and forty breast cancer patients undergoing elective operations were assigned to six groups according to treatment received before their operation and the use of intravenous anesthetics during anesthesia; non-adjuvant chemotherapy + propofol group (group NP, n = 40), Taxol + propofol group (group TP, n = 40), adriamycin + cyclophosphamide + 5-Fu + propofol group (group CP, n = 40), non-adjuvant chemotherapy + etomidate group (group NE, n = 40), taxol + etomidate group (group TE, n = 40), adriamycin + cyclophosphamide + 5-Fu + etomidate group (group CE, n = 40). We set the beginning effect-site concentration (Ce) of propofol as 3.0 µg/ml and etomidate as 0.2 µg/ml. The concentration was increased by steps until the patient was asleep, (OAAS class I-II), then gave fentanyl 3 µg/kg and rocuronium 0.6 mg/kg and intubated three minutes later. The patients' age, height, and weight were recorded. BIS was recorded before induction, at the initial effect-site concentration and at loss of consciousness. The effect-site concentration was recorded when patient lost consciousness. RESULTS: There were no significant differences between groups in general conditions before treatment; such as BIS of consciousness, age, sex and body mass index. The EC(50) of propofol in the NP, TP and CP groups was 4.11 µg/ml (95%CI: 3.96 - 4.26), 2.94 µg/ml (95%CI: 3.36 - 3.47) and 2.91 µg/ml (95%CI: 3.35 - 3.86), respectively. The EC50 of etomidate in the NE, TE and CE groups was 0.61 µg/ml (95%CI: 0.55 - 0.67), 0.38 µg/ml (95%CI: 0.33 - 0.44), and 0.35 µg/ml (95%CI: 0.34 - 0.36), respectively. There was no significant difference of BIS level before induction or in BIS50 level in any group when patients lost consciousness. CONCLUSIONS: The EC(50) of intravenous anesthetics to cause loss of consciousness in neoadjuvant chemotherapy groups is lower than in the control group. There was no significant difference of BIS level at which patients lost consciousness.


Assuntos
Anestésicos Intravenosos/uso terapêutico , Etomidato/uso terapêutico , Terapia Neoadjuvante/efeitos adversos , Propofol/uso terapêutico , Inconsciência/induzido quimicamente , Adulto , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Fluoruracila/uso terapêutico , Humanos , Pessoa de Meia-Idade , Paclitaxel/uso terapêutico
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