摘要
Vitamins are organic substances that are essential for the maintenance of life activities. Generally, vitamins need to be obtained from the diet or from some synthetic source as the body cannot synthesize vitamins, or the amounts of the synthesized vitamins are insufficient. At present, vitamins are widely used in medicine, food additives, feed additives, cosmetics and other fields, and the global demand for vitamins is constantly growing. Vitamins can be produced from chemical or microbial synthesis. Chemical synthesis usually requires harsh reaction conditions, produces serious wastes, and creates great potential safety hazard. In contrast, microbial synthesis of vitamins is greener, safer, and requires much less energy input. This review summarizes the advances in metabolic engineering for vitamins production in the past 30 years, with a focus on production of water-soluble vitamins (vitamins B1, B2, B3, B5, B6, B7, B9, B12 and vitamin C precursors) and lipid-soluble vitamins (vitamin A, precursors of vitamin D, vitamin E and vitamin K). Moreover, the bottlenecks for fermentative production of vitamins are discussed, and future perspectives for developing next generation vitamins producing strains using synthetic biotechnology are prospected.
Subject(s)
Biotechnology , Metabolic Engineering , Vitamin A , Vitamin K , Vitamins/analysis摘要
Objective:To analyze the clinical characteristics and prognosis of coronavirus disease 2019 (COVID-19) patients complicated with pneumothorax.Methods:The clinical data of 7 COVID-19 patients complicated with pneumothorax admitted to Huanggang Central Hospital from January 3 to March 10, 2020 were retrospectively analyzed. The clinical features, diagnosis and treatment were summarized, and experience in the treatment of COVID-19 was shared.Results:① General information: among the 7 patients, 5 were males and 2 were females. Four of them had no underlying disease, and 1 had a history of diabetes and hypertension. One patient had only a history of hypertension. There were 6 cases of right pneumothorax and 1 case of bilateral pneumothorax. The 7 patients had a long hospital stay, all over 4 weeks, mostly complicated with multiple organ dysfunction. ② Imaging examination: 1 case evolved from the early stage to the advanced stage within 1 week and to the severe stage within 2 weeks. Pneumothorax occurred 4 weeks later, and was absorbed within 2 weeks. The remaining 6 patients presented progressive stage on admission, all of them advanced to severe stage within 1 to 2 weeks, and most of them presented diffused consolidation shadows, striation shadows and fibrosis of both lungs, obvious pleural adhesion, and extremely slow lesion absorption. ③ Treatment: 1 severe patient with pneumothorax 4 weeks after onset was given non-invasive mechanical ventilation. The remaining 6 critically ill patients were treated with endotracheal intubation and mechanical ventilation. Five patients were treated with mechanical ventilation within 3 days after the occurrence of pneumothorax, and 1 patient was treated with mechanical ventilation after 11 days. ④ Outcome: 1 patient without endotracheal intubation was continuously given nasal high-flow oxygen therapy, and the condition was stable. Four of the 6 patients complicated with pneumothorax after endotracheal intubation died, and the other 2 patients successfully removed the drainage tube within 2 weeks of closed thoracic drainage, and their condition gradually stabilized.Conclusion:COVID-19 complicated with pneumothorax is a dangerous disease with poor prognosis, and should be paid adequate attention.
摘要
Objective: To evaluate the consistency of transesophageal echocardiography (TEE) and pulmonary artery catheter (PAC) method in monitoring cardiac volume load and cardiac hemodynamic indexes.Methods: A total of 45 patients undergoing coronary artery bypass grafting in our hospital were selected.The right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV) and right ventricular ejection fraction (RVEF) were monitored during surgery by TEE and PAC respectively.Consistency of monitored data was compared between two methods.Results: Both TEE and PAC indicated that compared with baseline level, after loading, there were significant rise in RVEDV [TEE: (38±6)ml vs.(51±9ml), PAC: (153±17)ml vs.(188±19)ml], RVESV [TEE: (19±4)ml vs.(33±5)ml, PAC: (92±16)ml vs.(110±23)ml], P0.05.Before therapy, RVEDV, RVESV and RVEF monitored by PAC and TEE showed significant positive correlation, and all relevant coefficients were >0.8 (r=0.844, 0.862, 0.916, P0.8 (r=0.892, P<0.01).Conclusion: In clinical monitor, the consistency of TEE and PAC is high,the former is non-traumatic,and is more convenient for clinical use.