Surface Chain-Transfer Ring-Opening Metathesis Polymerization.

Ring-opening metathesis polymerization (ROMP) is a powerful method to graft various types of polymer chains to a given surface. While surface-initiated ROMP (SI-ROMP) serves as an efficient tool for surface modification and is therefore widely reported, the method requires grafting (1) the olefin substrate and (2) the metathesis catalyst to the surface prior to the polymerization with multiple synthetic and work up steps. To overcome this difficulty, we proposed the use of the chain-transfer reaction as an alternative method for surface modification. Terminal olefins are grafted to the surface without the need to graft the metathesis catalysts, and polymers with olefin backbones are polymerized and grafted simultaneously via both ROMP and chain transfer (cross-metathesis between olefins from backbones and surfaces). Compared to SI-ROMP, this surface-chain transfer ROMP (SC-ROMP) method avoids grafting the catalyst and growing polymer chains from the surface and could be achieved in a single step. Various types of surfaces like carbon nanotubes, carbon fibers, graphene nanosheets, and silica microspheres are used for demonstration. We envision that this work could bring a convenient and effective solution to surface modification via ROMP.

Clinical Significance of Plasma D-Dimer and Fibrinogen in Outcomes after Stroke: A Systematic Review and Meta-Analysis.

BACKGROUND: There is increasing evidence on the prognostic significance of D-dimer and fibrinolysis in stroke. However, the systematic analysis of their relationship with adverse outcomes after stroke is lacking. Herein, we comprehensively assessed the correlation of D-dimer and fibrinolysis with stroke outcomes through meta-analysis. METHODS: Studies for systematic literature review were retrieved from PubMed, EMBASE, and Cochrane Library databases. The association of D-dimer and fibrinolysis with outcomes of stroke patients was expressed as an odds ratio (OR) with 95% confidence intervals (95% CI). RESULTS: Totally, 52 studies comprising 21,473 stroke patients were included. The results showed that the high D-dimer level was significantly associated with peripheral venous thrombosis after stroke (OR 1.03, 95% CI 1.01-1.05), poor outcome (MRS >2) after stroke (OR 1.731, 95% CI 1.464-2.048), death after stroke (OR 2.367, 95% CI 1.737-3.224), stroke recurrence (OR 1.229, 95% CI 1.113-1.358), and early neurologic deterioration (NIHSS >4) (OR 1.791, 95% CI 1.117-2.870). Moreover, high fibrinogen level was significantly associated with poor outcome (MRS >2) after stroke (OR 1.650, 95% CI 1.314-2.071), death after stroke (OR 1.310, 95% CI 1.128-1.520), stroke recurrence (OR 1.228, 95% CI 1.166-1.422), early neurologic deterioration (NIHSS >4) (OR 2.381, 95% CI 1.156-4.904), and coronary events after stroke (OR 1.427, 95% CI 1.232-1.653). CONCLUSION: Fibrinogen and D-dimer may be associated with adverse outcomes in patients with stroke, suggesting that they may serve as possible biomarkers for post-stroke adverse outcomes.

Implications of frailty in acute ischemic stroke receiving endovascular treatment: systematic review and meta-analysis.

BACKGROUND: Frailty is a state of cumulative degeneration of bodily functions that is consistently associated with poor outcomes in older people following illness. Combined stroke intervention and frailty may yield additive and synergistic effects adults with stroke. OBJECTIVE: To evaluate the safety and efficacy of endovascular therapy (EVT) in frail patients. METHODS: We conducted a systematic review of the relationship between debilitation and acute ischemic stroke (AIS) after EVT. Until August 2022, researchers have searched three databases (Pubmed, EMBASE and Cochrane). Random-effects meta-analysis, combined ratio (OR) and 95% confidence interval (95%CI) were used to assess efficacy values. The I2 statistic was used to assess heterogeneity. Comprehensive meta-analysis software was used for meta-analysis. RESULTS: We ultimately included eight studies including 3662 non-overlapping participants. Four studies used the Clinical Frailty Scale (CFS), two studies used the Hospital Frailty Risk Score (HFRS), a study used frailty index and a study used the comprehensive geriatric assessment (CGA). Frailty prevalence: 35%; 95% CI, 0.27-0.43; low quality evidence, downgraded due to heterogeneity, bias. Random effects showed that poor functional outcome (5 studies, OR 1.956, 95% CI 1.256-3.048) and mortality (9 studies, OR 2.320, 95% CI 1.680-3.205) was significantly associated with frailty. In adjusted analyses, poor functional outcome (4 studies, ORadj 1.189, 95% CI 1.043-1.357), and mortality (3 studies, ORadj 1.036, 95% CI 1.008-1.065) were significantly associated with frailty. CONCLUSION: Pre-stroke frailty is an important predictor of poor prognosis assessed by EVT and can be added to the classical predictors of stroke outcome. Routine assessment of pre-stroke frailty can help patients to make decisions about the efficacy of their choice of EVT.

Safety and efficacy of intravenous thrombolysis before mechanical thrombectomy in patients with atrial fibrillation.

BACKGROUND: Intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) is the standard treatment for patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO). However, the efficacy and safety of IVT before EVT in AIS-LVO patients with atrial fibrillation (AF) remains controversial. Thus, this study aims to assess the benefit of IVT plus EVT and direct EVT alone in AIS-LVO patients with AF. METHOD: Relevant studies that evaluated the outcomes of IVT plus EVT versus direct EVT alone in AIS-LVO patients with AF were systematically searched in PubMed, Embase, and Cochrane Library from inception to August 10, 2023. The outcomes included successful reperfusion (score of 2b to 3 for thrombolysis in cerebral infarction), symptomatic intracerebral hemorrhage (sICH), good clinical outcome (modified Rankin scale score ≤ 2) at 3 months, and 3-month mortality. RESULT: Eight eligible observational studies involving 6998 (3827 in the IVT plus EVT group and 3171 in the direct EVT group) patients with AIS-LVO complicated by AF were included. Compared with direct EVT, IVT plus EVT resulted in better 3-month clinical outcomes (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.05-1.54) and lower 3-month mortality (OR 0.78, 95% CI 0.68-0.88). However, the incidence of sICH (OR 1.26, 95% CI 0.91-1.75) and the rate of successful reperfusion (OR 0.98, 95% CI 0.83-1.17) were not significantly different between treatment modalities. CONCLUSION: IVT plus EVT leads to better functional outcomes and lower mortality in AIS-LVO patients with AF. Withholding IVT plus EVT from patients with AF alone may not be justified.

Efficacy and safety of nalbuphine for epidural labor analgesia at high altitude: An observational study.

Xining is located at the eastern edge of the Qinghai-Tibet Plateau, with an average altitude of >7000 feet (>2000 m). Nalbuphine is a kappa-opioid receptor agonist that can provide analgesia with fewer side effects than other opioid analgesics. This study aimed to evaluate pain control, side effects, and neonatal outcomes from combining nalbuphine with sufentanil and ropivacaine in 600 women during epidural anesthesia while giving birth at a high altitude in Xining, China. A total of 600 parturients receiving epidural labor analgesia were randomly divided into 2 groups, each group 300 parturients. The nalbuphine group received nalbuphine, sufentanil, and ropivacain, the control group only received sufentanil and ropivacain. The analgesic effect was evaluated through the Visual Analogue Scale scores. Neonatal outcomes were mainly evaluated through the Apgar Scores. Compared to the control group, the nalbuphine group showed lower Visual Analogue Scale scores at all time points after analgesia (P < .05). In comparison with the control group, parturients in the nalbuphine group showed lower incidence rates of fever at delivery, 24-hour postpartum bleeding, and pruritus (P < .05). However, between the 2 groups, there were no statistically significant differences in the remaining maternal and infant outcomes and neonatal outcomes (P > .05). Moreover, no adverse effects on neonatal outcomes were observed. The findings from this study support findings from previous studies that nalbuphine provided safe epidural analgesia without significant side effects for the mother and infant, and showed both safety and efficacy when used during labor at high altitude.

Intravenous thrombolysis in acute ischemic stroke patients with pre-stroke disability: A systematic review and meta-analysis.

BACKGROUND: Intravenous thrombolysis (IVT), which is safe and effective, is the first-line therapy for acute ischemic stroke (AIS). However, its benefit for AIS patients with pre-stroke disability (PSD) is controversial. OBJECTIVE: We determined the association of PSD with the safety and efficacy of IVT among patients with AIS. METHODS: We searched PubMed, Embase, and the Cochrane Library from inception to May 23, 2022. The articles focusing on outcomes of AIS patients with PSD receiving IVT were retrieved. We used the random-effects model to pool outcomes including mortality, 24 h NIHSS improvement, symptomatic intracerebral hemorrhage (sICH), favorable functional outcome (FFO), the favorable outcome, and mortality prevalence. RESULTS: Ten studies (including 245,773 participants) that reported the outcomes of AIS patients with PSD undergoing IVT were included. In unadjusted analyses, PSD was associated with mortality (10 studies; odds ratio [OR] 1.739, 95% confidence interval [CI], 1.336-2.407), FFO (7 studies; OR 1.057, 95% CI, 1.015-1.100), 24 h NIHSS improvement (5 studies; OR .840, 95% CI, .819-.917, p = .000), and sICH (9 studies; OR .773, 95% CI, .481-1.243). In adjusted analyses, PSD was associated with mortality (seven studies; ORadj 1.789, 95% CI, 1.413-2.264), FFO (five studies; ORadj 1.087, 95% CI, 1.002-1.179), 24 h NIHSS improvement (five studies; ORadj .837, 95% CI, .799-.876), and sICH (five studies; ORadj .857, 95% CI, .725-1.012). The prevalence of FFO and mortality in patients with pre-stroke modified Rankin Scale scores of 2-5 were 49% (0.42-0.56) and 37% (0.21-0.53), respectively. CONCLUSIONS: Patients with PSD undergoing IVT had a higher mortality rate than those without PSD. Meanwhile, PSD was associated with FFO, and there was no significant difference in sICH and 24 h NIHSS improvement. High-quality data are needed to clarify the benefits of administering IVT in these patients.

Environmental toxic metal contaminants and risk of stroke: a systematic review and meta-analysis.

The relationship between toxic metals in the environment and clinical stroke risk remains unclear, although their role as immunotoxicants and carcinogens has been well established. We conducted a systematic review of the relationship between five metals (arsenic, mercury, copper, cadmium, and lead) and stroke. First, we comprehensively searched 3 databases (Pubmed, EMBASE, and Cochrane) from inception until June 2021. Random-effects meta-analyses, pooled relative risks (RR) and 95% confidence intervals (CI) were applied to evaluate the effect value. We finally identified 38 studies involving 642,014 non-overlapping participants. Comparing the highest vs. lowest baseline levels, chronic exposure to lead (RR = 1.07; 95%CI,1.00-1.14), cadmium (RR = 1.30; 95%CI,1.13-1.48), and copper (RR = 1.19; 95%CI,1.04-1.36) were significantly associated with stroke risks. However, the other two metals (arsenic and mercury) had less effect on stroke risk. Further analysis indicated that the association was likely in a metal dose-dependent manner. The results may further support the possibility that environmental toxic metal contaminants in recent years are associated with the increased risk of stroke.

Inhibition of L-Cysteine on the Browning of Fresh Wet Noodles.

This research explored the effect of L-cysteine on the browning of fresh wet noodles (FWN). With the increasing addition of L-cysteine (0.02-0.1%), the ΔL* decreased and Δa*, Δb* increased. The L-cysteine could reduce the pH value and polyphenol oxidase (PPO) activity and increase the retention rate of polyphenol of FWN. It suggested that L-cysteine could inhibit the browning of FWN by decreasing pH value, PPO activity, and the oxidation of polyphenols. In the in vitro PPO solution, the inhibitory effect of L-cysteine on PPO activity was related to the decrease in pH and the ability of chelating Cu2+. According to UPLC-TOF-MS analysis, L-cysteine could reduce the generation of browning products, which suggested that L-cysteine could react with the browning intermediate product (quinone) and generate a light-colored substance (-C9H10NO4S). L-cysteine effectively inhibited the browning of FWN and had the potential to be used in noodle industry.

In situ resuspension rate monitoring method in the littoral zone with multi-ecotypes of a shallow wind-disturbed lake.

Sediment resuspension has been recognized as a crucial internal process in aquatic ecosystems. However, there is still a lack of reliable measuring methods due to the complex hydrodynamic conditions in large shallow eutrophic lakes. In this study, sequential sediment traps (SST) and instantaneous multiple point (IMP) methods were compared at 6 sites located in the littoral zone of Zhushan Bay in Lake Taihu. Results show that the average resuspension rates (RRs) estimated using the IMP method at sites 1 to 6 were 266.39, 272.79, 235.17, 254.95, 392.25, and 483.85 g·m-2d-1, respectively. While the RRs estimated using the SST method were 195.16, 236.99, 116.76, 156.23, 389.53, and 509.85 g·m-2d-1, respectively. In wind-disturbed areas, both methods were suitable for RR analysis in large and shallow eutrophic lakes and SST provides high-resolution temporal RR estimations. However, in the areas with cyanobacterial blooms and vegetation cover, the IMP method overestimated the RR. Therefore, SST was more suitable across different conditions in large and shallow eutrophic lakes, providing a simple, accurate, and high-resolution temporal estimation of RR, while furthering our understanding of lake evolution processes.

[Deposition Characteristics of Suspended Solids and the Response of Dissolved Nutrients in Spring in the Western Lakeside of Taihu Lake].

To reveal the spatiotemporal characteristics of nutrients in the deposition process of suspended solids in lakeside zone,in situ deposition tests were performed in the western lakeside of Taihu Lake,and the contents of TP,TN,NH4+-N and NO3--N were measured and analyzed.The results showed that the deposition fluxes in the western lakeside of Taihu Lake ranked as follows:artificial reed areas >non-vegetation nearshore areas >natural reed areas >non-vegetation offshore areas,with their average values of (1383.40±925.60),(1208.67±743.50),(278.72±142.53),(245.58±154.25) g·(m2·d)-1,respectively.From the 6th day,the deposition volume steadily increased,with the deposition rate larger than the decomposition rate.Through the 15-day continuous in situ observation,the content of TP in nearshore zone was 2-3 folds larger than that of offshore zone,and the content of NH4+-N was significantly different from that of NO3--N in the settlement bottle (P<0.01).The deposition volume was significantly and positively correlated to both TN and NH4+-N contents in the water column (P<0.01,n=42),suggesting that the TN and NH4+-N contents in the overlying water increased with the deposition fluxes.The correlation coefficient between TN and NH4+-N was 0.84,implicating that the increase of deposition flux may accelerate the mutual transformation between different forms of nitrogen.These findings should be taken into account in the current control of black blooms and nutrient management in Taihu Lake.