Effect of the Activation Force of Mechanophore on Its Activation Selectivity and Efficiency in Polymer Networks.

In recent decades, more than 100 different mechanophores with a broad range of activation forces have been developed. For various applications of mechanophores in polymer materials, it is crucial to selectively activate the mechanophores with high efficiency, avoiding nonspecific bond scission of the material. In this study, we embedded cyclobutane-based mechanophore cross-linkers (I and II) with varied activation forces (fa) in the first network of the double network hydrogels and quantitively investigated the activation selectivity and efficiency of these mechanophores. Our findings revealed that cross-linker I, with a lower activation force relative to the bonds in the polymer main chain (fa-I/fa-chain = 0.8 nN/3.4 nN), achieved efficient activation with 100% selectivity. Conversely, an increase of the activation force of mechanophore II (fa-II/fa-chain = 2.5 nN/3.4 nN) led to a significant decrease of its activation efficiency, accompanied by a substantial number of nonspecific bond scission events. Furthermore, with the coexistence of two cross-linkers, significantly different activation forces resulted in the almost complete suppression of the higher-force one (i.e., I and III, fa-I/fa-III = 0.8 nN/3.4 nN), while similar activation forces led to simultaneous activations with moderate efficiencies (i.e., I and IV, fa-I/fa-IV = 0.8 nN/1.6 nN). These findings provide insights into the prevention of nonspecific bond rupture during mechanophore activation and enhance our understanding of the damage mechanism within polymer networks when using mechanophores as detectors. Besides, it establishes a principle for combining different mechanophores to design multiple mechanoresponsive functional materials.

Azobenzene as a photoswitchable mechanophore.

Azobenzene has been widely explored as a photoresponsive element in materials science. Although some studies have investigated the force-induced isomerization of azobenzene, the effect of force on the rupture of azobenzene has not been explored. Here we show that the light-induced structural change of azobenzene can also alter its rupture forces, making it an ideal light-responsive mechanophore. Using single-molecule force spectroscopy and ultrasonication, we found that cis and trans para-azobenzene isomers possess contrasting mechanical properties. Dynamic force spectroscopy experiments and quantum-chemical calculations in which azobenzene regioisomers were pulled from different directions revealed that the distinct rupture forces of the two isomers are due to the pulling direction rather than the energetic difference between the two isomers. These mechanical features of azobenzene can be used to rationally control the macroscopic fracture behaviours of polymer networks by photoillumination. The use of light-induced conformational changes to alter the mechanical response of mechanophores provides an attractive way to engineer polymer networks of light-regulatable mechanical properties.

[Retracted] Role of microRNA­210 in human intervertebral disc degeneration.

[This retracts the article DOI: 10.3892/etm.2016.3176.].

Sustainable mechanochemical growth of double-network hydrogels supported by vascular-like perfusion.

Double-network (DN) gels are unique mechanochemical materials owing to their structures that can be dynamically remodelled during use. The mechanical energy applied to DN gels is efficiently transferred to the chemical bonds of the brittle network, generating mechanoradicals that initiate the polymerisation of pre-loaded monomers, thereby remodelling the materials. To attain continuous remodelling or growth in response to repetitive mechanical stimuli, a sustainable supply of chemical reagents to such dynamic materials is essential. In this study, inspired by the vascular perfusion transporting nutrients to cells, we constructed a circulatory system for a continuous supply of chemicals to channel-containing DN hydrogels (c-DN gels). The perfusion of monomer solutions through the channel and permeability of the c-DN gels not only replenishes the monomers consumed by the polymerisation but also replenishes the water loss caused by the surface evaporation of hydrogel, thereby freeing the mechanochemical process of DN gels from the constraints of the underwater environment. The facile chemical supply enabled us to modulate the mechanical enhancement of the c-DN gel and attain muscle-like strengthening under repeated mechanical training in deoxygenated air. We also studied the kinetics of polymer growth and strengthening and deciphered unique features of mechanochemical reaction in DN gels including the extremely long-living radicals and delayed mechanical strengthening.

Exposure to acute waterborne cadmium caused severe damage on lipid metabolism of freshwater fish, revealed by nuclear lipid droplet deposition in hepatocytes of rare minnow.

Cadmium (Cd) is a widely distributed aquatic toxic heavy metal with the potential to disrupt fish metabolism; however, more research is needed to clarify the underlying mechanisms. In the present study, rare minnows (Gobiocypris rarus) were used to detect the effects of cadmium on freshwater fish lipid metabolism and its underlying mechanism by histopathological observation, measurement of serum and liver biochemical indexes, and analysis of gene expression in terms of lipid oxidation, synthesis and transport. Here, severe damage, such as cytoplasmic lipid droplet (LD) accumulation, ectopic deposition of LDs, and the appearance of nuclear LDs (nLDs), was detected after exposure to 2.0 mg/L or higher concentrations (2.5 and 2.8 mg/L CdCl2) for 96 h. Other damage included abnormal increases in rough endoplasmic reticulum (RER) lamellae in a fingerprint or concentric circle pattern and necrosis of hepatocytes, and which was observed in the livers of fish exposed to 2.0 mg/L CdCl2.. Both hepatic and serum lipids, such as triglycerides and total cholesterol, were significantly increased after exposure to 2.0 mg/L CdCl2, as was serum lipase (LPS). Hepatic lipase and lipoprotein lipase remained unchanged, in accordance with the unchanged hepatic mRNA transcripts of PPARɑ. Furthermore, the mRNA transcripts of both SCD and SQLE were significantly decreased. Moreover, hepatic and serum low-density and high-density lipoprotein cholesterol showed significant changes, which were accompanied by a significant increase and decrease in hepatic APOAI and APOB100 mRNA levels, respectively. All the results indicate the presence of severe damage to hepatic lipid metabolism and that disrupted lipid transport may play a key role in the accumulation of hepatic LDs. In addition, the hepatic nLDs of nonmammalian vertebrates and their location across the nuclear envelope are intriguing, suggesting that large-size nLDs are a common marker for severe liver damage.

Comparative effectiveness of prophylactic strategies for preeclampsia: a network meta-analysis of randomized controlled trials.

OBJECTIVE: Preeclampsia is a common disease during pregnancy that leads to fetal and maternal adverse events. Few head-to-head clinical trials are currently comparing the effectiveness of prophylactic strategies for preeclampsia. In this network meta-analysis, we aimed to compare the efficacy of prophylactic strategies for preventing preeclampsia in pregnant women at risk. DATA SOURCES: Articles published in or before September 2021 from PubMed, Embase, Web of Science, Cochrane Library, and ClinicalTrials.gov, references of key articles, and previous meta-analyses were manually searched. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials comparing prophylactic strategies preventing preeclampsia with each other or with negative controls were included. METHODS: Two reviewers independently extracted data, assessed the risk of bias, and assessed evidence certainty. The efficacy of prophylactic strategies was estimated by frequentist and Bayesian network meta-analysis models. The primary composite outcome was preeclampsia/ pregnancy-induced hypertension. RESULTS: In total, 130 trials with a total of 112,916 patients were included to assess 13 prophylactic strategies. Low-molecular-weight heparin (0.60; 95% confidence interval, 0.42-0.87), vitamin D supplementation (0.65; 95% confidence interval, 0.45-0.95), and exercise (0.68; 95% confidence interval, 0.50-0.92) were as efficacious as calcium supplementation (0.71; 95% confidence interval, 0.62-0.82) and aspirin (0.79; 95% confidence interval, 0.72-0.86) in preventing preeclampsia/pregnancy-induced hypertension, with a P score ranking of 85%, 79%, 76%, 74%, and 61%, respectively. In the head-to-head comparison, no differences were found between these effective prophylactic strategies for preventing preeclampsia and pregnancy-induced hypertension, except with regard to exercise, which tended to be superior to aspirin and calcium supplementation in preventing pregnancy-induced hypertension. Furthermore, the prophylactic effects of aspirin and calcium supplementation were robust across subgroups. However, the prophylactic effects of low-molecular-weight heparin, exercise, and vitamin D supplementation on preeclampsia and pregnancy-induced hypertension varied with different risk populations, dosages, areas, etc. The certainty of the evidence was moderate to very low. CONCLUSION: Low-molecular-weight heparin, vitamin D supplementation, exercise, calcium supplementation, and aspirin reduce the risk of preeclampsia/pregnancy-induced hypertension. No significant differences between effective prophylactic strategies were found in preventing preeclampsia. These findings raise the necessity to reevaluate the prophylactic effects of low-molecular-weight heparin, vitamin D supplementation, and exercise on preeclampsia.

Mortality of Escalation and Modulation Antithrombotic Therapy in Coronary Artery Disease Patients: A Meta-analysis of Randomized Controlled Trials.

BACKGROUND: The net clinical benefit of antithrombotic therapy (ATT) reflects the concomitant effects of bleeding and ischemic events. OBJECTIVES: We sought to assess the overall effect of the modulation or escalation of ATT on all-cause mortality as well as ischemic and bleeding events. METHODS: We performed a meta-analysis of randomized controlled trials comparing escalation or modulation of ATT versus standard ATT in patients with coronary artery disease. A total of 32 studies with 160,659 subjects were enrolled in this analysis. RESULTS: Neither escalation nor modulation of ATT has significant effect on all-cause mortality (escalation: relative risk [RR]: 0.94, 95% confidence interval [CI]: 0.85-1.04; modulation: RR: 0.90; 95% CI: 0.81-1.01). Compared with standard ATT therapy, escalation of ATT was associated with lower risk of myocardial infarction (MI; RR: 0.84, 95% CI: 0.76-0.94), but had a higher risk of major or minor bleeding (RR: 1.38, 95% CI: 1.15-1.66). Modulation of ATT was associated with a similar risk of MI (RR: 1.07, 95% CI: 0.96-1.19), but a reduced risk for major or minor bleeding (RR: 0.58, 95% CI: 0.51-0.66). Meta-regression combining both escalation and modulation studies found that the heterogeneity of all-cause mortality was mainly attributed to the heterogeneity of major or minor bleeding (adjusted R-squared = 100.00%, p = 0.004), but not to MI. CONCLUSION: Either escalation or modulation of ATT has little benefit in all-cause mortality. The variability of the treatment effects on all-cause mortality was mainly attributed to the variability of major or minor bleeding, but not to MI.

Force-triggered rapid microstructure growth on hydrogel surface for on-demand functions.

Living organisms share the ability to grow various microstructures on their surface to achieve functions. Here we present a force stamp method to grow microstructures on the surface of hydrogels based on a force-triggered polymerisation mechanism of double-network hydrogels. This method allows fast spatial modulation of the morphology and chemistry of the hydrogel surface within seconds for on-demand functions. We demonstrate the oriented growth of cells and directional transportation of water droplets on the engineered hydrogel surfaces. This force-triggered method to chemically engineer the hydrogel surfaces provides a new tool in addition to the conventional methods using light or heat, and will promote the wide application of hydrogels in various fields.

Prognostic significance of multiple triglycerides-derived metabolic indices in patients with acute coronary syndrome.

BACKGROUND: Triglyceride (TG) and its related metabolic indices, all recognized as surrogates of insulin resistance, have been demonstrated to be relevant to clinical prognosis. However, the relative value of these TG-related indices for predicting cardiovascular events among patients with acute coronary syndrome (ACS) has not been examined. METHODS: The TG, the triglyceride-glucose (TyG) index, the atherogenic index of plasma, TG to high-density lipoprotein cholesterol ratio, and the lipoprotein combine index were assessed in 1694 ACS patients undergoing percutaneous coronary intervention. The primary endpoint was major adverse cardiovascular event (MACE), which was the composite of all-cause mortality, stroke, myocardial infarction, or unplanned repeat revascularization. RESULTS: During a median follow-up of 31 months, 345 patients (20.4%) had MACE. The risk of the MACE was increased with higher TG and the four TG-derived metabolic indices [TG-adjusted hazard ratio (HR) = 1.002, 95% CI: 1.001-1.003; TyG index-adjusted HR = 1.736, 95% CI: 1.398-2.156; atherogenic index of plasma-adjusted HR = 2.513, 95% CI: 1.562-4.043; TG to high-density lipoprotein cholesterol ratio-adjusted HR = 1.148, 95% CI: 1.048-1.258; and lipoprotein combine index-adjusted HR = 1.009, 95% CI: 1.004-1.014; P < 0.001 for all indices]. TG and all the four indices significantly improved the predictive ability for MACE in addition to the baseline model. Among them, TyG index showed the best ability for predicting MACE compared with the other three indices from all the three measurements ( P < 0.05 for all comparison). CONCLUSIONS: TG and TG-derived metabolic indices were all strongly associated with MACE among ACS patients undergoing percutaneous coronary intervention. Among all the indices, TyG index showed the best ability to predict the risk of MACE.

Effect of Alirocumab on Coronary Calcification in Patients With Coronary Artery Disease.

Background: Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors have been documented with significantly reduction in LDL cholesterol levels and cardiovascular events. However, evidence regarding the impact of PCSK9 inhibitors on coronary calcification is limited. Methods: Eligible patients with intermediate coronary lesions and elevated LDL cholesterol values were randomized to either alirocumab 75 mg Q2W plus statin (atorvastatin 20 mg/day or rosuvastatin 10 mg/day) therapy or standard statin therapy. Calcium score based on coronary computed tomographic angiography at baseline and follow up were compared. Results: Compared with baseline levels, LDL cholesterol were significantly decreased in both groups, while the absolute reduction of LDL cholesterol levels were higher in patients treated with alirocumab (1.69 ± 0.52 vs. 0.92 ± 0.60, P < 0.0001). Additionally, patients in alirocumab group demonstrated a significant reduction of Lp(a) levels, whereas it was not observed in the standard statin group. Notably, greater increases in the percentage changes of CAC score (10.6% [6.3-23.3] vs. 2.9% [-6.7-8.3]; P < 0.0001) were observed in the statin group compared to the alirocumab group. Consistently, CAC progression was significantly lower in the alirocumab group than in the standard statin group (0.6 ± 2.2% vs. 2.7 ± 2.3%; P = 0.002). Conclusions: Study indicated that administration of the PCSK9 inhibitors to statins produced significantly lower rate of CAC progression in patients with coronary artery disease. Further studies with CAC progression and their clinical outcomes are needed. Trial Registration: ClinicalTrials.gov, Identifier: NCT04851769.

Azo-Crosslinked Double-Network Hydrogels Enabling Highly Efficient Mechanoradical Generation.

Double-network (DN) hydrogels have recently been demonstrated to generate numerous radicals by the homolytic bond scission of the brittle first network under the influence of an external force. The mechanoradicals thus generated can be utilized to trigger polymerization inside the gels, resulting in significant mechanical and functional improvements to the material. Although the concentration of mechanoradicals in DN gels is much higher than that in single-network hydrogels, a further increase in the mechanoradical concentration in DN gels will widen their application. In the present work, we incorporate an azoalkane crosslinker into the first network of DN gels. Compared with the traditional crosslinker N,N'-methylenebis(acrylamide), the azoalkane crosslinker causes a decrease in the yield stress but significantly increases the mechanoradical concentration of DN gels after stretching. In the azoalkane-crosslinked DN gels, the concentration of mechanoradicals can reach a maximum of ∼220 µM, which is 5 times that of the traditional crosslinker. In addition, DN gels with the azoalkane crosslinker show a much higher energy efficiency for mechanoradical generation. Interestingly, DN gels crosslinked by a mixture of azoalkane crosslinker and traditional crosslinker also exhibit excellent radical generation performance. The increase in the mechanoradical concentration accelerates polymerization and can broaden the application range of force-responsive DN gels to biomedical devices and soft robots.

Regional Differences in the Ratio of Observed and Expected In-hospital Mortality for Acute Coronary Syndrome Patients in China: The Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome Project Analysis.

Previous studies reported regional variations in in-hospital acute coronary syndrome (ACS) mortality, but the reasons for that were not clearly defined. We explored whether differences in patient characteristics could explain regional variation. The Improving Care for Cardiovascular Disease in China (CCC)-ACS project is an ongoing national registry and quality improvement project, involving 150 tertiary hospitals from 30 provinces across China. We applied a prediction model that included patient-specific variables to calculate the expected in-hospital mortality. For each province, we reported the observed, expected in-hospital mortality and the risk-adjusted ratio which is based on the observed divided by the expected mortality. From 2014 to 2018, 79 585 ACS patients were enrolled. The average in-hospital mortality was 1.8%. There was a wide variation in the in-hospital mortality among different provinces (0.2-3.9%). Patient characteristics explained part of this variation because of differences in the expected in-hospital mortality (0.7-2.8%). There was a substantial variation in the risk-adjusted ratio among provinces (0.2-3.5), which suggests that the variations in the mortality cannot be completely explained by the differences in patient characteristics. In conclusion, we observed a wide regional variation in mortality for ACS, part of which could be explained by the difference in patient characteristics.

Association of serum complement C1q with cardiovascular outcomes among patients with acute coronary syndrome undergoing percutaneous coronary intervention.

OBJECTIVE: To determine the association of serum complement C1q levels with cardiovascular outcomes among patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI), and evaluate the value of C1q modified by high-sensitivity C-reactive protein (hs-CRP) levels as an independent predictor. METHODS: As a single-center prospective observational study, we analyzed 1701 patients who had received primary or elective PCI for ACS at Beijing Anzhen Hospital, Capital Medical University, Beijing, China between June 1, 2016 and November 30, 2017. The associations of C1q modified by hs-CRP with major adverse cardiovascular events (MACE) were determined in survival analysis. RESULTS: Patients with the lowest C1q tertile had the highest cumulative risk of MACE (log-rank P = 0.007). In fully adjusted Cox regression models, stratifying the total population according to hs-CRP dichotomy, C1q was significantly associated with MACE in patients with hs-CRP levels less than 2 mg/L but not in those with 2 mg/L or more (P interaction = 0.02). In patients with hs-CRP levels less than 2 mg/L, with the lowest C1q tertile as reference, the risk of MACE was reduced by 40.0% in the middle C1q tertile [hazard ratio (HR) = 0.600, 95% CI: 0.423-0.852, P = 0.004] and by 43.9% in the highest C1q tertile (HR = 0.561, 95% CI: 0.375-0.840, P = 0.005). CONCLUSIONS: Serum complement C1q is significantly associated with cardiovascular outcomes in patients with ACS undergoing PCI, only when hs-CRP levels are less than 2 mg/L. This finding implicates the usefulness of C1q for the risk stratification in ACS patients with reduced systemic inflammation.

Stroke of antiplatelet and anticoagulant therapy in patients with coronary artery disease: a meta-analysis of randomized controlled trials.

BACKGROUND: We performed a meta-analysis sought to investigate the risk of stroke with antiplatelet and anticoagulant therapies among patients with coronary artery disease (CAD). METHODS: We searched PubMed, EMBASE, and Cochrane Library for randomized controlled trials from January 1995 to March 2020. Studies were retrieved if they reported data of stroke for patients with CAD and were randomized to receive intensive versus conservative antithrombotic therapies, including antiplatelet and oral anticoagulant (OAC). Analyses were pooled by random-effects modeling. A total of 42 studies with 301,547subjects were enrolled in this analysis. RESULTS: Intensive antithrombotic therapy significantly reduced risk of all stroke (RR 0.86, 95% CI 0.80-0.94) and ischemic stroke (RR 0.80, 95% CI 0.71-0.91), but increased risk of hemorrhagic stroke (RR 1.36, 95% CI 1.00-1.86) and intracranial hemorrhage (RR 1.46, 95% CI 1.17-1.81). Subgroup analyses indicated that OAC yields more benefit to all stroke than antiplatelet therapy (OAC: RR 0.73, 95% CI 0.58-0.92; Antiplatelet: RR 0.90, 95% CI 0.83-0.97; Between-group heterogeneity P value = 0.030). The benefit of antiplatelet therapy on all stroke and ischemic stroke were mainly driven by the studies comparing longer versus shorter duration of dual antiplatelet therapy (All stroke: RR 0.86, 95% CI 0.78-0.95; ischemic stroke: RR 0.84, 95% CI 0.75-0.94). CONCLUSIONS: Among CAD patients who have already received antiplatelet therapy, either strengthening antiplatelet or anticoagulant treatments significantly reduced all stroke, mainly due to the reduction of ischemic stroke, although it increased the risk of hemorrhagic stroke and intracranial hemorrhage. OAC yields more benefit to all stroke than antiplatelet therapy.

[Distribution characteristics of soil water and nutrients in pear orchard and their relationship with yields in loess hilly region]. / é»„åœŸä¸˜é™µåŒºé¦™æ¢¨å›­åœŸå£¤æ°´åˆ†ã€å »åˆ†åˆ†å¸ƒç‰¹å¾åŠå ¶ä¸Žäº§é‡çš„å ³ç³».

We analyzed soil water, nutrients, and yields in three different slope sites in the sloping farmland under Yuluxiang pear planted in the loess hilly region of Western Shanxi, across the growth periods and different soil depths. The results showed that: 1) The yield of pear was in the order of high slope site > middle slope site > low slope site. In high slope site, the yield was significantly correlated with soil water content (SWC), soil organic matter (SOM), available potassium (AK), with AK showing the most significant effect. The yield of pear in middle and low slope sites was significantly correlated with SWC, SOM, and total nitrogen (TN), with SWC having the most significant effect on yield. The contents of SWC, SOM, available phosphorus (AP) and TN in high slope site were higher than in middle and low slope sites, while AK was the highest in middle slope site. 2) Among different soil depths, soil nutrient contents were the highest within 0-20 cm soil layer, but the lowest within 20-40 cm soil layer. The SWC was significantly lower within 0-20 cm than the other soil layers and was the highest within 20-40 cm soil layer. 3) Among different growth periods, the contents of SOM, AP, and TN were the highest in flowering period, the SWC was the highest in fruiting period, and AK content was the highest in maturing period. It was suggested that in the future management of pear water and fertilizer in the region, more K fertilizer should be applied in the high slope sites in the flowering period, while N and P compound fertilizer should be applied in the fruiting period, to enhance irrigation in middle and low slope sites to decrease the limitation of water with 300 m3·hm-2. Our results could provide theoretical support and data refe-rence for planting precision irrigation and scientific fertilization of pear planted in loess hilly areas.

Effect of alirocumab on coronary plaque in patients with coronary artery disease assessed by optical coherence tomography.

BACKGROUND: Proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors have been demonstrated to produce significantly greater reduction in LDL cholesterol levels and cardiovascular events than standard statin therapy. However, evidence on the impact of PCSK9 inhibitors on coronary plaque composition and morphology is limited. METHODS: In this open-label randomized study, eligible patients with intermediate coronary lesions and elevated LDL cholesterol values were randomized to either alirocumab 75 mg Q2W plus statin (atorvastatin 20 mg/day or rosuvastatin 10 mg/day) therapy or standard care. Optical coherence tomography (OCT) assessments for target lesions were obtained at baseline and at 36 weeks of follow-up. RESULTS: LDL cholesterol levels were significantly decreased in both the alirocumab and standard care arms, whereas the absolute reduction in LDL cholesterol was significantly greater in patients treated with alirocumab (1.72 ± 0.51 vs. 0.96 ± 0.59, P < 0.0001). Compared with standard care, the addition of alirocumab to statins was associated with significantly greater increases in minimum fibrous cap thickness (18.0 [10.8-29.2] µm vs 13.2 [7.4-18.6] µm; P = 0.029), greater increases in minimum lumen area (0.20[0.10-0.33] mm2 vs 0.13 [0.12-0.24] mm2; P = 0.006) and a greater diminution in maximum lipid arc (15.1̊ [7.8-24.5] vs. 8.4̊ [2.0-10.5]; P = 0.008). CONCLUSIONS: The addition of alirocumab to statins can not only provide additional LDL cholesterol lowering effects but also have a potential role in promoting a more stable plaque phenotype. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04851769 . Registered 2 Mar 2019.

Overproduction of D-pantothenic acid via fermentation conditions optimization and isoleucine feeding from recombinant Escherichia coli W3110.

D-pantothenic acid (D-PA), as a crucial vitamin, is widely used in food, animal feed, cosmetics, and pharmaceutical industries. In our previous work, recombinant Escherichia coli W3110 for production of D-PA was constructed through metabolic pathway modification. In this study, to enhance D-PA production, statistical optimization techniques including Plackett-Burman (PB) design and Box-Behnken design (BBD) first were adopted to optimize the culture condition. The results showed that the glucose, ß-alanine and (NH4)2SO4 have the most significant effects on D-PA biosynthesis. The response surface model based on BBD predicted that the optimal concentration is glucose 56.0 g/L, ß-alanine 2.25 g/L and (NH4)2SO4 11.8 g/L, the D-PA titer increases from 3.2 g/L to 6.73 g/L shake flask fermentation. For the fed-batch fermentation in 5 L fermenter, the isoleucine feeding strategy greatly increased the titer and productivity of D-PA. As a result, titer (31.6 g/L) and productivity (13.2 g/L·d) of D-PA were achieved, they increased by 4.66 times and 2.65 times, respectively, compared with batch culture. At the same time, the accumulation of acetate reduced from 29.79 g/L to 8.55 g/L in the fed-batch fermentation. These results demonstrated that the optimization of medium composition and the cell growth rate are important to increase the concentration of D-PA for microbial fermentation. This work laid the foundation for further research on the application of D-PA microbial synthesis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02773-0.

Nutritional Risk Index Improves the GRACE Score Prediction of Clinical Outcomes in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention.

Background: Malnutrition has been shown to be associated with adverse cardiovascular outcomes in many patient populations. Aims: To investigate the prognostic significance of malnutrition as defined by nutritional risk index (NRI) in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) and whether NRI could improve the GRACE score based prognostic models. Methods: This study applied NRI among 1,718 patients with ACS undergoing PCI. Patients were divided into three nutritional risk groups according to their baseline NRI: no nutritional risk (NRI ≥ 100), mild nutritional risk (97.5 ≤ NRI <100), and moderate-to-severe nutritional risk (NRI <97.5). The primary endpoint was the composite of major adverse cardiovascular events (MACE), including all-cause death, non-fatal stroke, non-fatal myocardial infarction, or unplanned repeat revascularization. Results: During a median follow-up of 927 days, 354 patients developed MACE. In the overall population, compared with normal nutritional status, malnutrition was associated with increased risk for MACE [adjusted HR for mild and moderate-to-severe nutritional risk, respectively: 1.368 (95%CI 1.004-1.871) and 1.473 (95%CI 1.064-2.041)], and NRI significantly improved the predictive ability of the GRACE score for MACE (cNRI: 0.070, P = 0.010; IDI: 0.005, P < 0.001). In the diabetes subgroup, malnutrition was associated with nearly 2-fold high adjusted risk of MACE, and the GRACE score combined with NRI appeared to have better predictive ability than that in the overall population. Conclusion: Malnutrition as defined by NRI was independently associated with MACE in ACS patients who underwent PCI, especially in individuals with diabetes, and improved the predictive ability of the GRACE score based prognostic models.