Effects of meteorological factors on influenza transmissibility by virus type/subtype.

BACKGROUND: Quantitative evidence on the impact of meteorological factors on influenza transmissibility across different virus types/subtypes is scarce, and no previous studies have reported the effect of hourly temperature variability (HTV) on influenza transmissibility. Herein, we explored the associations between meteorological factors and influenza transmissibility according to the influenza type and subtype in Guangzhou, a subtropical city in China. METHODS: We collected influenza surveillance and meteorological data of Guangzhou between October 2010 and December 2019. Influenza transmissibility was measured using the instantaneous effective reproductive number (Rt). A gamma regression with a log link combined with a distributed lag non-linear model was used to assess the associations of daily meteorological factors with Rt by influenza types/subtypes. RESULTS: The exposure-response relationship between ambient temperature and Rt was non-linear, with elevated transmissibility at low and high temperatures. Influenza transmissibility increased as HTV increased when HTV < around 4.5 °C. A non-linear association was observed between absolute humidity and Rt, with increased transmissibility at low absolute humidity and at around 19 g/m3. Relative humidity had a U-shaped association with influenza transmissibility. The associations between meteorological factors and influenza transmissibility varied according to the influenza type and subtype: elevated transmissibility was observed at high ambient temperatures for influenza A(H3N2), but not for influenza A(H1N1)pdm09; transmissibility of influenza A(H1N1)pdm09 increased as HTV increased when HTV < around 4.5 °C, but the transmissibility decreased with HTV when HTV < 2.5 °C and 3.0 °C for influenza A(H3N2) and B, respectively; positive association of Rt with absolute humidity was witnessed for influenza A(H3N2) even when absolute humidity was larger than 19 g/m3, which was different from that for influenza A(H1N1)pdm09 and influenza B. CONCLUSIONS: Temperature variability has an impact on influenza transmissibility. Ambient temperature, temperature variability, and humidity influence the transmissibility of different influenza types/subtypes discrepantly. Our findings have important implications for improving preparedness for influenza epidemics, especially under climate change conditions.

Effect of Levosimendan on Ventricular Systolic and Diastolic Functions in Heart Failure Patients: A Meta-Analysis of Randomized Controlled Trials.

ABSTRACT: Levosimendan, a calcium sensitizer, exerts inotropic action through improving left ventricular ejection fraction. We noticed that only few clinical studies are published in which the effects of levosimendan on cardiac function are studied by echocardiography. When screening the literature (PubMed, Embase, and CENTRAL, from inception to August 2020), we found 29 randomized controlled trials on levosimendan containing echocardiographic data. We included those studies, describing a total of 574 heart failure patients, in our meta-analysis and extracted 14 ultrasonic parameters, pooling the effect estimates using a random-effect model. Our analysis of the diastolic parameters of the left ventricle shows that levosimendan reduce the early/late transmitral diastolic peak flow velocity ratio [standardized mean difference (SMD) -0.45 to 95% confidence interval (CI) (-0.87 to -0.03), P = 0.037] and E/e' (e': mitral annulus peak early diastolic wave velocity using tissue-doppler imaging) [SMD -0.59, 95% CI (-0.8 to -0.39), P < 0.001]. As it regards the systolic parameters of the right ventricle, levosimendan increased tricuspid annular plane systolic excursion [SMD 0.62, 95% CI (0.28 to 0.95), P < 0.001] and tricuspid annular peak systolic velocity [SMD 0.75, 95% CI (0.35 to 1.16), P < 0.001], and reduced systolic pulmonary artery pressure [SMD -1.02, 95% CI (-1.32, -0.73), P < 0.001]. As it regards the diastolic parameters of the right ventricle, levosimendan was associated with the decrease of Aa (peak late diastolic tricuspid annular velocity using tissue-doppler imaging) [SMD -0.38, 95% CI (-0.76 to 0), P = 0.047] and increase of Ea (peak early diastolic tricuspid annular velocity using tissue-doppler imaging) [SMD 1.03, 95% CI (0.63 to 1.42), P < 0.001] and Ea/Aa [SMD 0.86, 95% CI (0.18 to 1.54), P = 0.013]. We show that levosimendan is associated with an amelioration in the diastolic and systolic functions of both ventricles in heart failure patients.

The benefits of defibrillator in heart failure patients with cardiac resynchronization therapy: A meta-analysis.

BACKGROUND: Current guidelines did not provide recommendations on indications of an additional implantable cardioverter-defibrillator (ICD) to patients receiving cardiac resynchronization therapy (CRT), and it still remains controversial due to lack of evidence from randomized controlled trials. METHOD: PubMed, Embase, and Cochrane CENTRAL from the inception to May 2020 were systematically screened for studies reporting on the comparison of cardiac resynchronization therapy with defibrillator (CRT-D) and cardiac resynchronization therapy with pacemaker (CRT-P), focusing on the adjusted hazard ratio (aHR) of all-cause mortality. We pooled the effects using a random-effect model. RESULTS: Twenty-one studies encompassing 69,919 patients were included in this meta-analysis. With no restriction to characteristics of including population, CRT-D was associated with a lower all-cause mortality compared with CRT-P significantly (aHR: 0.80, 95% confidence interval [CI]: 0.74-0.87, I2  = 36.8%, p < .001). This mortality benefit was also observed in patients with ischemic cardiomyopathy (aHR: 0.74, 95% CI: 0.64-0.86, I2  = 0%, p < .001). However, there is no significant difference in patients with nonischemic cardiomyopathy (NICM) (aHR: 0.91, 95% CI: 0.82-1.01, I2  = 0%, p = .087), older age (age ≥75 years, aHR: 0.96, 95% CI: 0.83-1.12, I2  = 0%, p = .610). Subgroup analysis was performed and indicated the survival benefit of CRT-D for primary prevention compared with CRT-P (aHR: 0.87, 95% CI: 0.79-0.95, I2  = 0%, p = .003). CONCLUSION: After adjusted the differences in clinical characteristics, additional ICD therapy was associated with a reduced all-cause mortality in patients receiving CRT. However, our work suggested that additional ICD may not be applied to elderly (≥75 years) or patients with NICM.

Incidence and Predictors of Structural Valve Deterioration after Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis.

BACKGROUND: Transcatheter aortic valve replacement (TAVR), widely used as an alternative therapy in patients with severe aortic stenosis, is expected to be offered to low-risk patents with a longer life expectancy. The durability of transcatheter aortic valve is becoming of increasing importance. METHOD: PubMed, Embase, and Cochrane CENTRAL from the inception to March 2020 were systematically screened for studies reporting on structural valve deterioration (SVD) in TAVR patients. Incidence of SVD was diagnosed according to the latest European consensus as the primary end point. Predictors of SVD evaluated at multivariable analysis and cumulative incidence function (CIF) of SVD were the secondary end point. RESULT: Twelve studies encompassing 10031 patients evaluating the incidence of SVD were included, with a follow-up between 1 and 8 years. The pooled incidence of SVD was 4.93% (95% CI, 2.75%-7.70%, I 2 = 96%) at 1 year and 8.97% (95% CI, 6.89%-11.29%, I 2 = 86%) in the long term (≥5 years). Subgroup analysis was performed to identify the valve type that may result in partial heterogeneity. SVD was more frequent in patents with a valve diameter of <26 mm (HR: 3.57, 1.47-8.69), oral anticoagulants (OAC), exposure at discharge (OR: 0.48, 0.38-0.61), or by a disease of renal dysfunction (OR 1.42, 1.03-1.96). CONCLUSION: SVD represents infrequent events after TAVR in the long term (>5 years), occurring more commonly in renal dysfunction patients, with small valve diameter and without OAC exposure. There may be an underestimation of the incidence if we assume death as a competing risk.

Effect of levosimendan on renal function in background of left ventricular dysfunction: a meta-analysis of randomized trials.

OBJECTIVE: Levosimendan, an inotrope, is widely used in the management of heart failure (HF) and cardiac surgery, but it remains uncertain whether levosimendan can improve renal function in patients with left ventricular dysfunction (LVD). METHODS: PubMed, Embase, and Cochrane CENTRAL from the inception to June 2020 were systematically screened for randomized controlled trials (RCTs) to investigate whether levosimendan offers kidney-related advantages in cardiovascular patients with LVD. We pooled the effects using a random-effect model. RESULTS: Twenty-eight studies enrolling 5069 patients were included. Levosimendan reduced the sCr (SMD -0.28, 95% CI (-0.48, -0.09), P = 0.005, I2 = 52.5%, high quality) and the risk of ARF (relative risk 0.75, 95%CI (0.60, 0.95), P = 0.017, I2 = 11.3%, moderate-quality) in patients with LVD compared with control group. The reduction of sCr was more pronounced in patients with a relatively higher baseline sCr level. For secondary outcomes, levosimendan therapy was associated with the improvement of GFR (SMD 0.32, 95%CI (-0.05, 0.68), P = 0.092, I2 = 55.1%, low-quality) and urine output (SMD 0.42, 95%CI (0.06, 0.79), P = 0.024, I2 = 50.0%, very low-quality), but there was no significant reduction in BUN (SMD -0.14, 95%CI (-0.97, 0.70), P = 0.774, I2 = 77.9%, very low-quality). CONCLUSIONS: Levosimendan might improve renal function of patients with LVD.

Structures, magnetic and catalytic properties of three sandwich-type silicotungstates containing tetranuclear copper(II) clusters.

Three sandwich-type silicotungstates, formulated as [Cu4(H2O)2(SiW9O34)2] x 12 NH4 x 22 H2O (1), [Cu4(H2O)2(SiW9O34)2] x 12 NH4 x 11 H2O (2) and {[Cu(NH3)4]2[Cu(H2O)4][Cu4(H2O)2(SiW9O34)2]} 2[Cu(NH3)4(H2O)] x 2 NH4 x 6 H2O (3), were synthesized by microwave irradiation and hydrothermal reaction. Crystal structural analysis reveals that 1-3 possess the same dimeric polyoxoanions [Cu2SiW9O34(H2O)]2(12-) featuring tetranuclear copper(II) clusters. Magnetic studies indicate that the Cu4 clusters exhibit ferromagnetic coupling interactions. Investigation on their catalytic activity for the oxidation of ethylbenzene suggests that catalytic activity of 1-3 is closely related to the acidity of complexes and the existence of unsaturated coordination sites in the complex.

Construction of polyoxometalates-based coordination polymers through direct incorporation between polyoxometalates and the voids in a 2D network.

A series of polyoxometalates (POMs)-based coordination polymers, namely, {[Cu(2,3-Me2pz)(2,5-Me2pz)0.5]4(SiW12O40)(2,5-Me2pz)}n (2,3-Me2pz = 2,3-dimethylpyrazine; 2,5-Me2pz = 2,5-dimethylpyrazine; 1), {[Cu2(4,4'-bipy)4(H2O)4](SiW12O40)(H2O)18}n (4,4'-bipy = 4,4'-bipyridine; 2), {[Cu(2-Mepz)1.5]3(PMo12O40)(H2O)3.5}n (2-Mepz = 2-methylpyrazine; 3), {[Ag(2,3-Me2pz)1.5]4(SiW12O40}n (4), {[Cu(pz)1.5]4(SiW12O40)(H2O)3}n (pz = pyrazine; 5), {[Cu(2,3-Me2pz)1.5]4(SiW12O40)}n (6), {[Cu(4,4'-bipy)1.75]4(SiW12O40)(H2O)2}n (7), and {[Cu2(4,4'-bipy)4(H2O)4](SiW12O40)(4,4'-bipy)2(H2O)4}n (8), were synthesized through direct incorporation between POMs and the voids of the 2D network. Crystal structural analysis reveals that the relationship between the size of the void of the 2D network and that of POMs is of key importance for successful synthesis of POMs-based open metal-organic frameworks. Guest replacement shows that the pore size of the framework constructed through direct incorporation between POMs and the voids of the 2D network is very sensitive to guest molecules.