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1.
Obstet Gynecol Sci ; 67(5): 481-488, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39168470

RESUMO

OBJECTIVE: This study aimed to evaluate the prevalence of urinary incontinence (UI) and its associated risk factors among pregnant Korean women, as UI significantly impacts their quality of life. METHODS: A cross-sectional study involving singleton pregnant women was conducted between April and December 2023. Data were collected using a questionnaire assessing demographic information and UI symptoms. The International Consultation on Incontinence Questionnaire-UI short form was used to diagnose UI. RESULTS: A total of 824 pregnant women from three centers participated, with an overall prenatal UI prevalence of 40.2% (331/824). Stress UI was most common (77.1%), followed by mixed UI (16.9%), and urgency UI (6.0%). Risk factors for UI included prior delivery mode, specifically vaginal delivery (adjusted odds ratio [aOR], 5.61; 95% confidence interval [CI], 1.40-22.50; P=0.015) and combined vaginal and cesarean delivery (aOR, 23.14; 95% CI, 1.77-302.74; P=0.017). Additionally, second trimester (aOR, 1.99; 95% CI, 1.19-3.32; P=0.009) and third trimester (aOR, 4.44; 95% CI, 2.65-7.40; P<0.001) were associated with increased UI risk. Conversely, drinking alcohol before pregnancy was a protective factor (aOR, 0.72; 95% CI, 0.53-0.99; P=0.046). CONCLUSION: Approximately 40% of Korean pregnant women experience prenatal UI. Prior delivery mode and advanced gastrointestinal age are significant risk factors. Further research with postpartum and long-term follow-ups is needed.

2.
Eur J Surg Oncol ; 50(10): 108584, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39154427

RESUMO

OBJECTIVE: This study aimed to compare survival and complications between minimally invasive surgery and open surgery and evaluate related risk factors in patients with non-endometrioid endometrial cancer. METHODS: Clinicopathologic characteristics; survival outcomes; complications; and prognostic factors associated with progression-free survival and overall survival were compared among patients with non-endometrioid endometrial cancer who underwent primary staging surgery using laparoscopic, robotic, or open abdominal surgery (2004-2017). RESULTS: In total, 91 patients were included: 41 and 50 underwent minimally invasive surgery and open surgery, respectively. The minimally invasive surgery and open surgery groups showed similar progression-free survival (5-year progression-free survival rate, 58.7 % vs. 58.5 %; P = .925) and overall survival (5-year overall survival rate, 73.6 % vs. 80.3 %; P = .834). Intraoperative (7.2 % vs. 6.0 %; P = .111) and postoperative surgical complications (14.6 % vs. 26.0 %; P = .165) were similar between the groups. However, blood loss was lower (mean, 305.1 vs. 561.2 ml, P < .001) and hospital stay was shorter (mean, 8.2 vs. 15.4 days, P < .001) in the minimally invasive surgery group. Using multivariate analysis, lymphovascular space invasion was identified as poor prognostic factor for progression-free survival (adjusted hazard ratio [HR], 3.054; 95 % confidence interval [CI], 1.521-6.132; P = .002) and overall survival (adjusted HR, 3.918; 95 % CI, 1.455-10.551; P = .007), whereas age ≥ 60 years was poor prognostic factor for only overall survival (adjusted HR, 5.0953; 95 % CI, 1.660-15.378; P = .004). CONCLUSIONS: Surgical outcomes did not differ between the minimally invasive and open surgery group in patients with non-endometrioid endometrial cancer. Lymphovascular space invasion was a significant survival factor in this context.


Assuntos
Neoplasias do Endométrio , Laparoscopia , Estadiamento de Neoplasias , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Robóticos , Humanos , Feminino , Neoplasias do Endométrio/cirurgia , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/mortalidade , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Idoso , Taxa de Sobrevida , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Estudos Retrospectivos , Intervalo Livre de Progressão , Histerectomia/métodos , Prognóstico , Tempo de Internação/estatística & dados numéricos
3.
Ann Surg Oncol ; 31(9): 6040-6047, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38961041

RESUMO

BACKGROUND: This report describes the oncologic outcomes for patients with advanced ovarian cancer who had bowel surgery performed by gynecologic oncologists (GOs) and compares the outcomes with those for bowel surgery performed by general surgeons (GSs) during maximal cytoreductive surgery. METHODS: Patients from six academic institutions who had FIGO stage III or IV ovarian cancer and underwent any bowel surgeries during maximal cytoreductive surgery were eligible for the study. The patients were divided into two groups according to whether bowel surgery was performed by a GO or a GS. In both groups, the GOs were mainly involved in extra bowel debulking procedures. Perioperative and survival outcomes were compared between the two groups. RESULTS: The 761 patients in this study included 113 patients who underwent bowel surgery by a GO and 648 who had bowel surgery by a GS. No discernible differences were observed in age, American Society of Anesthesiology (ASA) score, FIGO stage, histologic type, timing of cytoreductive surgery (primary or interval debulking surgery), or complications between the two groups. The GO group exhibited a shorter operation time than the GS group. Kaplan-Meier analysis showed no survival differences between the two groups. In the Cox analysis, non-serous cell types and gross residual diseases were associated with adverse effects on overall survival. However, performance of bowel surgery by a GO did not have an impact on survival. CONCLUSION: Performance of bowel surgery by a GO during maximal cytoreductive surgery is both feasible and safe. These results should be reflected in the training system for GOs regarding bowel surgery, and further research is needed to confirm that GOs can play a more leading role in performing extra-uterine procedures.


Assuntos
Procedimentos Cirúrgicos de Citorredução , Oncologistas , Neoplasias Ovarianas , Humanos , Feminino , Procedimentos Cirúrgicos de Citorredução/métodos , Neoplasias Ovarianas/cirurgia , Neoplasias Ovarianas/patologia , Pessoa de Meia-Idade , Taxa de Sobrevida , Idoso , Cirurgiões , Prognóstico , Seguimentos , Adenocarcinoma de Células Claras/cirurgia , Adenocarcinoma de Células Claras/patologia , Estadiamento de Neoplasias , Cistadenocarcinoma Seroso/cirurgia , Cistadenocarcinoma Seroso/patologia , Adulto , Ginecologia
4.
ChemSusChem ; 17(3): e202301315, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-37932870

RESUMO

The successful synthesis of finely tuned Ni1.5 Sn nanoalloy phases containing ZnO catalyst with a small particle size (6.7 nm) from a mixed-metal zeolitic imidazolate framework (MM-ZIF) is investigated. The catalyst was evaluated for the efficient production of 1,2-propanediol (1,2-PDO) from crude glycerol and comprehensively characterized using several analytical techniques. Among the catalysts, 3Ni1Sn/ZnO (Ni/Sn=3/1) showed the best catalytic performance and produced the highest yield (94.2 %) of 1,2-PDO at ~100 % conversion of glycerol; it also showed low apparent activation energy (15.4 kJ/mol) and excellent stability. The results demonstrated that the synergy between Ni-Sn alloy, finely dispersed Ni metallic sites, and the Lewis acidity of SnOx species-loaded ZnO played a pivotal role in the high activity and selectivity of the catalyst. The confirmation of acetol intermediate and theoretical calculations verify the Ni1.5 Sn phases provide the least energetic pathway for the formation of 1,2-PDO selectively. The reusability of solvent for successive ZIF synthesis, along with the excellent recyclability of the ZIF-derived catalyst, enables an overall sustainable process. We believe that the present synthetic protocol that uses MM-ZIF for the conversion of various biomass-derived platform chemicals into valuable products can be applied to various nanoalloy preparations.

5.
In Vivo ; 38(1): 431-436, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38148064

RESUMO

BACKGROUND/AIM: Vasopressin injected during myomectomy is known to effectively reduce bleeding but is sometimes associated with intraoperative vasoconstriction and hypertension due to systemic absorption. Although there is a growing preference for the use of diluted vasopressin, evidence of its effect and safety is still lacking. PATIENTS AND METHODS: We performed a randomized controlled pilot trial to evaluate the effect and safety of vasopressin diluted in a constant volume during robot-assisted laparoscopic myomectomy (RALM), where a total of 39 women with uterine fibroids were randomly assigned into the following three groups (group 1, 0.2 IU/ml; group 2, 0.1 IU/ml; group 3, 0.05 IU/ml with a total of 100 ml of normal saline). The primary endpoint was to compare estimated blood loss (EBL), and the secondary endpoints were to compare postoperative value and drop ratio of hemoglobin, operation time, transfusion, hospitalization, and complications among the three groups. RESULTS: There were no differences in the number and largest size of uterine fibroids, total weight of uterine fibroids, console time, and volumes of intravenous fluid administered during RALM among the three groups, whereas combined operation was performed more commonly in group 2 than in groups 1 and 3 (53.9% vs. 0 to 7.7%; p=0.01). The primary and secondary endpoints were also not different among the three groups. However, two patients in group 1 (15.4%) showed vasopressin-related hypertension. CONCLUSION: Vasopressin diluted in a volume of 100 ml showed an effective hemostatic effect and safety during RALM (Trial No. NCT04874246 in ClinicalTrial.gov).


Assuntos
Hipertensão , Laparoscopia , Leiomioma , Robótica , Miomectomia Uterina , Neoplasias Uterinas , Humanos , Feminino , Miomectomia Uterina/efeitos adversos , Neoplasias Uterinas/tratamento farmacológico , Neoplasias Uterinas/cirurgia , Projetos Piloto , Leiomioma/tratamento farmacológico , Leiomioma/cirurgia , Vasopressinas , Perda Sanguínea Cirúrgica/prevenção & controle , Laparoscopia/efeitos adversos , Hipertensão/etiologia
6.
Cancer Med ; 12(19): 19449-19459, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37768030

RESUMO

OBJECTIVE: To identify the risk factors for failure of first-line poly (ADP-ribose) polymerase inhibitor (PARPi) maintenance therapy in patients with advanced ovarian cancer. METHOD: Patients with stage III-IV epithelial ovarian cancer who received first-line PARPi maintenance therapy were retrospectively reviewed. Clinicopathologic factors were compared between two groups-recur/progression of disease (PD) and non-recur/PD. RESULTS: In total, 191 patients were included. Median follow-up was 9.9 months, and recurrence rate was 20.9%. BRCA mutations were found in 63.4% patients. Postoperative residual tumor (60.5% vs. 37.8%), non-high grade serous carcinoma (HGSC) (15.0% vs. 6.0%), neoadjuvant chemotherapy (NAC) (55.0% vs. 35.8%), and pre-PARPi serum CA-125 levels ≥23.5 U/mL (35.9% vs. 15.2%) were more frequently observed in the recur/PD group. Multivariate Cox-regression analysis revealed pre-PARPi serum CA-125 levels ≥23.5 U/mL (HR, 2.17; 95%CI, 1.03-4.57; p = 0.042), non-HGSC (3.28; 1.20-8.97; p = 0.021), NAC (2.11; 1.04-4.26; p = 0.037), and no BRCA mutation (2.23; 1.12-4.44; p = 0.023) as independent risk factors associated with poor progression-free survival (PFS). A subgroup analysis according to BRCA mutation status showed that pre-PARPi serum CA-125 levels ≥26.4 U/mL were the only independent risk factor for poor PFS in women with BRCA mutations (2.75; 1.03-7.39; p = 0.044). Non-HGSC (5.05; 1.80-14.18; p = 0.002) and NAC (3.36; 1.25-9.04; p = 0.016) were independent risk factors in women without BRCA mutations. CONCLUSION: High pre-PARPi serum CA-125 levels, non-HGSC histology, NAC, and no BRCA mutation might be risk factors for early failure of first-line PARPi maintenance therapy. In women with BRCA mutations, high pre-PARPi serum CA-125 levels, which represent a large tumor burden before PARPi, were the only independent risk factor for poor PFS.


Assuntos
Antineoplásicos , Neoplasias dos Genitais Femininos , Neoplasias Ovarianas , Falha de Tratamento , Animais , Feminino , Humanos , Antineoplásicos/uso terapêutico , Carcinoma Epitelial do Ovário/tratamento farmacológico , Neoplasias dos Genitais Femininos/tratamento farmacológico , Gorilla gorilla , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/efeitos adversos , Estudos Retrospectivos , Fatores de Risco
7.
Gynecol Oncol ; 176: 122-129, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37515926

RESUMO

OBJECTIVE: To identify clinicopathological factors associated with disease recurrence for patients with 2018 FIGO stage IA with lymphovascular invasion to IB1 cervical cancer treated with minimally invasive surgery (MIS). METHODS: A total of 722 patients with cervical cancer between January 2010 and February 2021 were identified. Clinicopathological factors related to disease recurrence were analyzed. Disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method. To determine prognostic factors for DFS, a Cox proportional hazard regression model was used. RESULTS: Of 722 patients, 49 (6.8%) experienced disease recurrence (37 pelvis, 1 para-aortic lymph node, and 11 peritoneum). Five-year DFS and OS rates were 90.7% and 98.1%, respectively. In multivariate analysis, risk factors associated with disease recurrence were residual disease in the remaining cervix (OR, 3.122; 95% CI, 1.152-8.461; p = 0.025), intracorporeal colpotomy (OR, 3.252; 95% CI, 1.507-7.017; p = 0.003), and positive resection margin (OR, 3.078; 95% CI, 1.031-9.193; p = 0.044). The non-conization group had a higher percentage of stage IB1 (77.4% vs. 64.6%; p = 0.004) and larger tumor (10 mm vs. 7 mm; p < 0.001) than the conization group. Intracorporeal colpotomy and residual disease in the remaining cervix were independent variables associated with disease recurrence in patients undergoing MIS following conization. CONCLUSION: During MIS, patients with cervical cancer ≤2 cm in size can be vulnerable to peritoneal recurrences. Patients diagnosed with invasive cancer through conization often have low-risk pathological features, which may affect their survival outcomes.


Assuntos
Neoplasias dos Genitais Femininos , Neoplasias do Colo do Útero , Humanos , Feminino , Animais , Neoplasias do Colo do Útero/patologia , Neoplasias dos Genitais Femininos/cirurgia , Resultado do Tratamento , Gorilla gorilla , Estudos Retrospectivos , Histerectomia/métodos , Estadiamento de Neoplasias , Recidiva Local de Neoplasia/cirurgia , Recidiva Local de Neoplasia/patologia , Intervalo Livre de Doença , Procedimentos Cirúrgicos Minimamente Invasivos/métodos
8.
Gynecol Oncol ; 174: 106-113, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37172410

RESUMO

OBJECTIVES: To evaluate oncologic and pregnancy outcomes of fertility-sparing treatment (FST) using progestin in patients with stage I grade 2 endometrioid endometrial cancer (EC) without myometrial invasion (MI) or grade 1-2 with superficial MI. METHODS: Multicenter data of patients with stage I grade 2 EC without MI or grade 1-2 EC with superficial MI, who received FST between 2005 and 2021, were analyzed. Cox regression analysis identified independent factors for progressive disease (PD) during the FST. RESULTS: Altogether, 54 patients received FST [medroxyprogesterone acetate (500-1000 mg) in 44, megestrol acetate (40-800 mg) in 10] with concurrent levonorgestrel-releasing intrauterine devices use in 31. With median time to achieve a complete response (CR) of 10 (3-24) months, 39 patients (72.2%) achieved CR. Of the 15 patients who attempted to conceive after achieving CR, 7 (46.7%) became pregnant (2 abortions, 5 live births). During a median FST duration of 6 (3-12) months, nine patients (16.6%) were diagnosed with PD. Fifteen (38.5%) experienced recurrence with a median recurrence-free survival of 23 (3-101) months. In the multivariable analysis, tumor size before FST ≥2 cm (HR 5.456, 95% CI 1.34 to 22.14; p = 0.018) was significantly associated with a high PD rate during FST. CONCLUSION: The overall response rate to FST was promising, however, the PD rate was significant during the first 12 months of FST. Therefore, performing thorough endometrial biopsy and imaging studies is essential to strictly evaluate the extent of the disease every 3 months from FST initiation.


Assuntos
Neoplasias do Endométrio , Preservação da Fertilidade , Feminino , Humanos , Gravidez , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/uso terapêutico , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/patologia , Preservação da Fertilidade/métodos , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Resultado do Tratamento , Progestinas/administração & dosagem , Progestinas/uso terapêutico , Progressão da Doença , Estadiamento de Neoplasias , Adolescente , Adulto Jovem , Adulto , Biópsia
9.
Reprod Sci ; 30(9): 2703-2714, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37067725

RESUMO

Endometriosis is an estrogen-dependent inflammatory disease characterized by the growth of endometrial-like tissues containing endometrial stromal cells and glandular epithelium outside the uterine cavity. An insufficient response to progesterone contributes to disease progression and systemic inflammation during the pathogenesis of endometriosis. Patients with endometriosis usually experience painful symptoms, dysmenorrhea, and infertility, which contribute to a significant reduction in their quality of life. To determine the possible molecular mechanisms of endometriosis and explore novel therapeutic targets, we derived primary human ovarian endometriotic stromal cells (hOESCs) from a patient of reproductive age with ovarian endometriosis. In this study, we successfully established immortalized human ovarian endometriotic stromal cell lines (ihOESCs) using primary stromal cells obtained from endometriotic lesions to overcome short lifespan and growth inhibition. Immortalization of hOESCs with human telomerase reverse transcriptase (hTERT) transfection led to cells that maintained a proliferative state under passage culture conditions without mutagenesis during cellular senescence. The morphology and karyotype of ihOESCs were unchanged compared with those of hOESCs. Moreover, ihOESCs were continuously positive for vimentin and negative for E-cadherin expression. Following decidual stimuli and inflammatory responses, both hOESCs and ihOESCs sensitively express decidualization markers and proinflammatory cytokines. Collectively, we characterized ihOESCs to maintain their phenotypic and functional properties with a longer lifespan and normal physiological responses than those of hOESCs. These immortalized cells could aid in a detailed understanding of the pathological mechanisms of endometriosis.


Assuntos
Endometriose , Feminino , Humanos , Endometriose/metabolismo , Qualidade de Vida , Endométrio/metabolismo , Linhagem Celular , Células Estromais/metabolismo
10.
J Pers Med ; 12(11)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36579527

RESUMO

Even though rotational intraperitoneal pressurized aerosol chemotherapy (RIPAC) has been developed to improve the distribution and penetration depth of anti-cancer agents by pressurized intraperitoneal aerosol chemotherapy (PIPAC), the optimal nozzle position and patient's posture have not been investigated. Thus, we used nine pigs weighing 50-60 kg, and sprayed 150 mL of 1% methylene blue as an aerosol through the nozzle, DreamPen® (Dreampac Corp., Wonju, Republic of Korea), with a flow rate of 0.6 ml/min under a pressure of 140 to 150 psi for RIPAC in six and three pigs with supine and Trendelenburg positions, respectively. When we evaluated its distribution and penetration depth, even distribution among 13 regions of the abdomen was observed in three pigs with Trendelenburg position regardless of the depth of the nozzle. Regarding penetration depth, the numbers of regions with maximal penetration depth were high in the 2 cm depth of the nozzle with supine position (n = 5) and the 4 cm depth with Trendelenburg position (n = 3). Conclusively, even distribution and maximal penetration of anti-cancer agents can be expected during RIPAC in the medium depth (4 cm) between the nozzle inlet and the visceral peritoneum located on the opposite side of it and the Trendelenburg position.

11.
ChemSusChem ; 13(18): 5050-5057, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32662246

RESUMO

We report for the first time the selective production of mannitol, a low-calorie sweetener and an important pharmaceutical ingredient, from fructose using Cu-SiO2 nanocomposite as catalyst and 1-butanol as solvent. When compared with water and ethanol, a lower fructose solubility was achieved in 1-butanol, which caused a lower fructose conversion and higher mannitol selectivity by reducing formation of side products. Among various Cu-based catalysts in 1-butanol, Cu(80)-SiO2 nanocomposite gave an unprecedented mannitol (83 %) and sorbitol (15 %) yield at 120 °C, 35 bar H2 , and 10 h reaction time. More importantly, this catalyst did not show any Cu leaching and its physicochemical properties were maintained after liquid-phase fructose hydrogenation whereas other Cu-based catalysts such as Cu(32)-Cr2 O and Cu(66)-ZnO did show significant leaching of Cu and Cr. Thus, Cu(80)-SiO2 nanocomposite and 1-butanol are regarded as a robust and highly efficient catalytic system for the selective hydrogenation of fructose to mannitol. Also, density functional theory calculations supported that in addition to the stable initial structure of adsorbed fructose, the mannitol pathway was more thermodynamically favorable than the sorbitol pathway. Notably, the highly pure mannitol (99 %) could be recovered from the sorbitol-containing 1-butanol solution by simple filtration. Therefore, the present protocol is a novel and effective method to produce pure mannitol from fructose in both an environmental and an industrial context.

12.
Obstet Gynecol Sci ; 63(2): 209-212, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32206662

RESUMO

Ovarian pregnancies comprise approximately 3% of ectopic pregnancies. Moreover, ovarian pregnancies in the second trimester are extremely rare. We herein present a case of ruptured ovarian pregnancy in the second trimester. A 26-year-old Asian woman presented to our hospital complaining of an abrupt mental change. She was pregnant; however, she had not been receiving antenatal care. Her initial vital signs were unstable, and pelvic ultrasound revealed pelvic fluid collection. We analyzed the hemoperitoneum and performed exploratory laparotomy. When her abdomen was opened, we observed that her right ovary was ruptured. Placental cord insertion originated from the ovary, and a fetus was found in the pelvic cavity. The ovarian pregnancy was detected in a delayed state. Pregnant women require appropriate antenatal care, and pelvic ultrasound should be performed in the second trimester to ensure that the fetus is in the intrauterine cavity.

14.
Obstet Gynecol Sci ; 60(5): 490-493, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28989929

RESUMO

High-intensity focused ultrasound (HIFU) is a non-invasive uterine fibroid treatment option for patients who want to preserve fertility. However, according to several reports regarding ablation of solid tumors by HIFU, there are rare complications in patients with uterine leiomyomas, and overall data are still insufficient. Here, we report rare and major complications of HIFU, such as delayed intestinal perforation, uterine perforation with recto-uterine fistula, and osteomyelitis 29 days after the HIFU procedure to treat multiple myomas. Thus, we present a very serious case resulting from HIFU treatment of uterine fibroids and a review of the literature.

15.
ChemSusChem ; 8(14): 2345-57, 2015 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-26192888

RESUMO

Biomass and biomass-derived carbohydrates have a high extent of functionality, unlike petroleum, which has limited functionality. In biorefinery applications, the development of methods to control the extent of functionality in final products intended for use as fuels and chemicals is a challenge. In the chemical industry, heterogeneous catalysis is an important tool for the defunctionalization of functionalized feedstocks and biomass-derived platform chemicals to produce value-added chemicals. Herein, we review the recent progress in this field, mainly of vapor phase chemical conversion of biomass-derived C4 -C6 carboxylic acids and esters using copper-silica nanocomposite catalysts. We also demonstrate that these nanocomposite catalysts very efficiently convert biomass-derived platform chemicals into cyclic compounds, such as lactones and hydrofurans, with high selectivities and yields.


Assuntos
Biomassa , Cobre/química , Nanocompostos/química , Dióxido de Silício/química , Animais , Catálise , Compostos Orgânicos/química
16.
ChemSusChem ; 7(11): 2998-3001, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25123894

RESUMO

Catalytic hydrogenation of organic carboxylic acids and their esters, for example, cellulosic ethanol from fermentation of acetic acid and hydrogenation of ethyl acetate is a promising possibility for future biorefinery concepts. A hybrid conversion process based on selective hydrogenation of butyric acid combined with fermentation of glucose has been developed for producing biobutanol. ZnO-supported Ru-Sn bimetallic catalysts exhibits unprecedentedly superior performance in the vapor-phase hydrogenation of biomass-derived butyric acid to n-butanol (>98% yield) for 3500 h without deactivation.


Assuntos
1-Butanol/química , Ácido Butírico/química , Rutênio/química , Estanho/química , Biomassa , Catálise , Fermentação , Glucose/química , Hidrogenação , Óxido de Zinco/química
17.
J Am Chem Soc ; 134(28): 11455-61, 2012 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-22769600

RESUMO

The photocatalyst-enzyme coupled system for artificial photosynthesis process is one of the most promising methods of solar energy conversion for the synthesis of organic chemicals or fuel. Here we report the synthesis of a novel graphene-based visible light active photocatalyst which covalently bonded the chromophore, such as multianthraquinone substituted porphyrin with the chemically converted graphene as a photocatalyst of the artificial photosynthesis system for an efficient photosynthetic production of formic acid from CO(2). The results not only show a benchmark example of the graphene-based material used as a photocatalyst in general artificial photosynthesis but also the benchmark example of the selective production system of solar chemicals/solar fuel directly from CO(2).


Assuntos
Dióxido de Carbono/química , Enzimas/química , Formiatos/síntese química , Processos Fotoquímicos , Fotossíntese , Energia Solar , Catálise , Espectroscopia de Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Phys Chem Chem Phys ; 7(6): 1315-21, 2005 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-19791350

RESUMO

Nitrogen-doped perovskite type materials, Sr2Nb2O7-xNx (0, 1.5 < x < 2.8), have been studied as visible light-active photocatalysts for hydrogen production from methanol-water mixtures. Nitrogen doping in Sr2Nb2O7 red-shifted the light absorption edge into the visible light range and induced visible light photocatalytic activity. There existed an optimum amount of nitrogen doping that showed the maximum rate of hydrogen production. Among the potential variables that might cause this activity variation, the crystal structure appeared to be the most important. Thus, as the extent of N-doping increased, the original orthorhombic structure of the layered perovskite was transformed into an unlayered cubic oxynitride structure. The most active catalytic phase was an intermediate phase still maintaining the original layered perovskite structure, but with a part of its oxygen replaced by nitrogen and oxygen vacancy to adjust the charge difference between oxygen and doped nitrogen. These experimental observations were explained by density functional theory calculations. Thus, in Sr2Nb2O7-xNx, N2p orbital was the main contributor to the top of the valence band, causing band gap narrowing while the bottom of conduction band due to Nb 4d orbital remained almost unchanged.


Assuntos
Metanol/química , Fotoquímica/métodos , Estrôncio/química , Água/química , Compostos de Cálcio/química , Catálise , Físico-Química/métodos , Condutividade Elétrica , Hidrogênio/química , Luz , Nitrogênio/química , Óxidos/química , Oxigênio/química , Titânio/química
20.
J Phys Chem B ; 109(6): 2093-102, 2005 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-16851200

RESUMO

In the search for efficient photocatalysts working under visible light, we have investigated the effect of cation substitution on a layered perovskite, La2Ti2O7. Among various metal dopants, only Cr and Fe induced intense absorption of visible light (lambda > 400 nm), and only these catalysts produced H2 photocatalytically from water in the presence of methanol under visible light irradiation (lambda > 420 nm). The polymerized complex method was found to be more efficient for fabrication of the present catalysts producing a more homogeneous structure than the solid-state reaction. The characterization by XRD, UV-vis DRS, XPS, and XANES revealed that doped Cr and Fe were present in the Cr3+ and Fe3+ states substituting for Ti sites in the La2Ti2O7 lattice. The theoretical calculation indicated that the most significant feature in the electronic band structure of the metal-doped La2Ti2O7 was the formation of a partially filled 3d band in the band gap of La2Ti2O7, while the contribution of these dopants on the valence band was negligible. Excitation of electrons from this localized interband to the conduction band of La2Ti2O7 was responsible for visible light absorption and the H2 evolution from water under visible light.

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