13 research outputs found
Esterification of octanoic acid with n-octyl alcohol over enzymatic catalysts
Przeprowadzono syntezę oktanianów n-oktylowych w obecności dostępnych w handlu katalizatorów enzymatycznych, NOVOZYM 435 i LIPOZYM Mm. Stężenia tych katalizatorów zmieniano w zakresie od 0,313% mas. do 1,25% mas. Pomiary wykonano w zakresie zmian wartości początkowego stosunku molowego substratów, alkoholu n-oktylowego do kwasu oktanowego, 1/1, 3/1, 5/1. Temperaturę reakcji zmieniano w zakresie 313 K do 333 K. Wstępne pomiary wykazały możliwość syntezy estrów w stosunkowo niskiej temperaturze reakcji ok. 323 K, w porównaniu z syntezę w obecności klasycznych katalizatorów chemicznych.Octyl octanoates were synthesized in the presence of commercially available enzymes NOVOZYM 435 i LIPOZYM Mm as catalysts in the range of concentration 0.313−1.25 of mass. %, at temperature 313−333 K, at initial mole substrate ratio (n-octyl alcohol to octanoic acid) 1/1, 3/1, 5/1. Preliminary experiments showed a possibility of synthesis of esters at relatively low reaction temperature of 323 K compared with the synthesis in the presence of classical chemicals
Copper/zinc catalysts in hydrogenation of carbon oxides
A review concerning main processes of hydrogenation of carbon oxides towards synthesis of methanol, mixture of methanol and higher aliphatic alcohols and one-step synthesis of dimethyl ether as well as methanol steam reforming is given. Low-temperature methanol catalysts and low-temperature modified methanol catalysts containing copper as primary component and zinc as secondary one are described
Investigations on the application of enzymes in the synthesis of octyl esters of medium-chain fatty acids
Przeprowadzono syntezę estrów oktylowych różnych kwasów tłuszczowych w obecności dostępnego w handlu katalizatora enzymatycznego lipase acrylic resin. Pomiary wykonano w zakresie zmian temperatury reakcji 313 K - 333 K, przy wartościach początkowego stosunku molowego substratów (alkoholu do kwasu), b, 1/1, 2,5/1, 3/1, 5/1. Istotną zaletą jest stosunkowo niska temperatura reakcji, 323 K. Uzyskano wysoki stopień konwersji kwasu, przy jedynie niewielkiej ilości produktów ubocznych.Octyl esters of medium-chain fatty acids were synthesized in the presence of commercially available enzyme lipase acrylic resin as catalyst in the range of temperatures 313 K - 333 K, at initial mole substrate ratio (alcohol to acid), b, 1/1, 2.5/1, 3/1, 5/1. The important advantage is relatively low reaction temperature of 323 K. High conversion of acid has been obtained and only small amounts of side products
Methanol as a High Purity Hydrogen Source for Fuel Cells: A Brief Review of Catalysts and Rate Expressions
Hydrogen is the fuel of the future, therefore many hydrogen production methods are developed. At present, fuel cells are of great interest due to their energy efficiency and environmental benefits. A brief review of effective formation methods of hydrogen was conducted. It seems that hydrogen from steam reforming of methanol process is the best fuel source to be applied in fuel cells. In this process Cu-based complex catalysts proved to be the best. In presented work kinetic equations from available literature and catalysts are reported. However, hydrogen produced even in the presence of the most selective catalysts in this process is not pure enough for fuel cells and should be purified from CO. Currently, catalysts for hydrogen production are not sufficiently active in oxidation of carbon monoxide. A simple and effective method to lower CO level and obtain clean H2 is the preferential oxidation of monoxide carbon (CO-PROX). Over new CO-PROX catalysts the level of carbon monoxide can be lowered to a sufficient level of 10 ppm
A Comparative Study on the Thermodynamics of Dimethyl Ether Synthesis from CO Hydrogenation and CO 2
Acute and long-term toxicity in patients undergoing induction chemotherapy followed by thermoradiotherapy for advanced cervical cancer
Objectives: To determine rates of vascular toxicity, acute kidney injury (AKI), chronic kidney disease (CKD) and survival in high-risk cervical cancer patients treated with platinum-based induction chemotherapy followed by thermoradiotherapy. Methods: Between January 1999 and April 2017, patients with large primary tumors (>6cm) and/or para-aortic lymph node (LN) metastases >1 cm and/or para-iliac LN >2 cm were included. Patient and tumor characteristics, Common Toxicity Criteria v4.03 scores, laboratory tests and treatment data were retrieved from patient records. CT scans were reviewed for the presence of thrombo-embolic events (TEE). The study protocol was approved by the Medical Ethics Review Committee of Erasmus MC, Rotterdam (MEC2017-133). Results: The 105 included patients had a mean age of 47.9 years (range 22–79) and a median follow-up time of 43 months (IQR 14–72). Median tumor size was 6.0 cm (range 2.6–11.5), 30% had a clinical FIGO stage ≥ IIIB and 42% had enlarged para-aortic LN. Cisplatin-based therapy was started in 86 patients (82%), of whom 30 (35%) switched to carboplatin and 47% of patients completed six cycles of platinum-based chemotherapy. All patients received external beam radiotherapy as planned, 98 patients (93%) underwent brachytherapy as planned or received an external boost, and 95 patients (90%) completed all five planned hyperthermia treatments. During cisplatin chemotherapy, 34 patients experienced AKI (39%). At last follow-up, 35% of patients had chronic renal toxicity (GFR 59 − 15/min/1.73 m2). At presentation, a TEE was present in 10 (10%) and another 23 (22%) patients experienced a TEE (18% venous, 4% arterial) during chemotherapy. Five-year overall survival was 58% (95% CI 47.8–68.6 SE 0.053). Conclusion: Achieving a five-year overall survival of 58%, platinum-based induction chemotherapy followed by thermoradiotherapy is an effective treatment for advanced-stage high-risk cervical cancer. However, treatment is accompanied by an unacceptably high prevalence of chemotherapy-associated TEE and acute kidney injury, as well as chronic kidney disease. Future studies should investigate the role of carboplatin in reducing toxicity and the effect of thromboprophylaxis in high-risk patients
Acute and long-term toxicity in patients undergoing induction chemotherapy followed by thermoradiotherapy for advanced cervical cancer
To determine rates of vascular toxicity, acute kidney injury (AKI), chronic kidney disease (CKD) and survival in high-risk cervical cancer patients treated with platinum-based induction chemotherapy followed by thermoradiotherapy. Between January 1999 and April 2017, patients with large primary tumors (>6cm) and/or para-aortic lymph node (LN) metastases >1 cm and/or para-iliac LN >2 cm were included. Patient and tumor characteristics, Common Toxicity Criteria v4.03 scores, laboratory tests and treatment data were retrieved from patient records. CT scans were reviewed for the presence of thrombo-embolic events (TEE). The study protocol was approved by the Medical Ethics Review Committee of Erasmus MC, Rotterdam (MEC2017-133). The 105 included patients had a mean age of 47.9 years (range 22–79) and a median follow-up time of 43 months (IQR 14–72). Median tumor size was 6.0 cm (range 2.6–11.5), 30% had a clinical FIGO stage ≥ IIIB and 42% had enlarged para-aortic LN. Cisplatin-based therapy was started in 86 patients (82%), of whom 30 (35%) switched to carboplatin and 47% of patients completed six cycles of platinum-based chemotherapy. All patients received external beam radiotherapy as planned, 98 patients (93%) underwent brachytherapy as planned or received an external boost, and 95 patients (90%) completed all five planned hyperthermia treatments. During cisplatin chemotherapy, 34 patients experienced AKI (39%). At last follow-up, 35% of patients had chronic renal toxicity (GFR 59 − 15/min/1.73 m2). At presentation, a TEE was present in 10 (10%) and another 23 (22%) patients experienced a TEE (18% venous, 4% arterial) during chemotherapy. Five-year overall survival was 58% (95% CI 47.8–68.6 SE 0.053). Achieving a five-year overall survival of 58%, platinum-based induction chemotherapy followed by thermoradiotherapy is an effective treatment for advanced-stage high-risk cervical cancer. However, treatment is accompanied by an unacceptably high prevalence of chemotherapy-associated TEE and acute kidney injury, as well as chronic kidney disease. Future studies should investigate the role of carboplatin in reducing toxicity and the effect of thromboprophylaxis in high-risk patients.</p