Patients undergoing assisted peritoneal dialysis to show a better technique survival: A competing risk analysis.

AIMS: To compare patient mortality and technique survival between patients undergoing assisted peritoneal dialysis (aPD) and self-care peritoneal dialysis (sPD). METHODS: Patients who underwent peritoneal dialysis (PD) at the dialysis center of Second Affiliated Hospital of Soochow University from January 1, 2012 to December 31, 2016, were included and followed to December 31, 2019. Subjects were divided into aPD and sPD groups according to whether the patient could independently complete the PD procedure. Differences in mortality and technique failure rates were compared using competing risk analysis. RESULTS: A total of 384 patients were included in this study, with 274 patients in the sPD group and 110 patients in the aPD group. The multivariate competing risk regression analysis revealed that age (HR 1.03,95%CI 1.01-1.05, P < .001), aPD (HR 1.84,95%CI 1.10-3.08, P = .02), diabetes (HR 1.51, 95%CI 1.00-2.30, P = .05), residual renal function (HR 0.89, 95%CI 0.82-0.97, P = .005) and serum albumin level (HR 0.92, 95% CI 0.89-0.96, P < .001) were the independent risk factors for mortality. Besides, technique failure in aPD patients was lower than in the sPD group (HR 0.85, 95% CI 0.68-0.97, P = .03). CONCLUSION: These results found that aPD patients had higher mortality rates but lower technique failure rates than sPD patients. Higher mortality in aPD is probably related to the negative selection of the more comorbid patients. ​ ​.

A novel gene of Kalanchoe daigremontiana confers plant drought resistance.

Kalanchoe (K.) daigremontiana is important for studying asexual reproduction under different environmental conditions. Here, we describe a novel KdNOVEL41 (KdN41) gene that may confer drought resistance and could thereby affect K. daigremontiana development. The detected subcellular localization of a KdN41/Yellow Fluorescent Protein (YFP) fusion protein was in the nucleus and cell membrane. Drought, salt, and heat stress treatment in tobacco plants containing the KdN41 gene promoter driving ß-glucuronidase (GUS) gene transcription revealed that only drought stress triggered strong GUS staining in the vascular tissues. Overexpression (OE) of the KdN41 gene conferred improved drought resistance in tobacco plants compared to wild-type and transformed with empty vector plants by inducing higher antioxidant enzyme activities, decreasing cell membrane damage, increasing abscisic acid (ABA) content, causing reinforced drought resistance related gene expression profiles. The 3,3'-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) staining results also showed less relative oxygen species (ROS) content in KdN41-overexpressing tobacco leaf during drought stress. Surprisingly, by re-watering after drought stress, KdN41-overexpressing tobacco showed earlier flowering. Overall, the KdN41 gene plays roles in ROS scavenging and osmotic damage reduction to improve tobacco drought resistance, which may increase our understanding of the molecular network involved in developmental manipulation under drought stress in K. daigremontiana.

Enhanced docosahexaenoic acid production by reinforcing acetyl-CoA and NADPH supply in Schizochytrium sp. HX-308.

Docosahexaenoic acid (DHA) production in Schizochytrium sp. HX-308 was evaluated by detecting enzymatic activities of ATP:citrate lyase (EC 4.1.3.8), malic enzyme (EC 1.1.1.40) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) at different fermentation stages. According to the analysis, a regulation strategy was proposed which reinforced acetyl-CoA and NADPH supply at a specific fermentation stage. DHA content of total fatty acids was increased from 35 to 60% by the addition of 4 g/L malic acid at the rapid lipid accumulation stage. Total lipid content also showed an apparent increase of 35% and reached 19 g/L when 40 mL ethanol/L was added at the late lipid accumulation stage.

Enhancing arachidonic acid production by Mortierella alpina ME-1 using improved mycelium aging technology.

Traditional mycelium aging technology was improved to enhance arachidonic acid (ARA) production by Mortierella alpina ME-1. Filtration step was skipped and additional carbon and nitrogen sources were fed during aging. The levels of the significant factors (time, temperature, ethanol, and KNO(3)) affecting ARA production during improved aging process were also optimized by applying response surface methodology (RSM), and the maximum ARA yield of 19.02 g/l was achieved in a 5 l fermentor at 5.6 days, temperature 13.7 degrees C, ethanol 42.44 g/l, and KNO(3) 2.62 g/l. This yield was 1.55 times higher than that of traditional aging technology. The improved mycelium aging technology is considered to be a useful strategy for enhancing ARA production.

A novel two-step fermentation process for improved arachidonic acid production by Mortierella alpina.

A novel two-step fermentation process was developed to enhance arachidonic acid (ARA) production by Mortierella alpina ME-1 in a 5 l fermentor. Agitation speed and aeration rate were adjusted from 180 to 40 rpm and from 0.6 to 1 vvm, respectively, after 5 days cultivation, to decrease physical damage to the mycelia and to extend the stationary phase. Moreover, 3% (w/v) and 2% (w/v) ethanol were fed after 5 and 7 days cultivation, respectively, to enhance ARA content of total lipid. Eventually, an ARA yield of 19.8 g/l was achieved, which was 1.7 times higher than that of a one-step fed-batch cultivation.