Cu Based Dilute Alloys for Tuning the C2+ Selectivity of Electrochemical CO2 Reduction.

Electrochemical CO2 reduction is a promising technology for replacing fossil fuel feedstocks in the chemical industry but further improvements in catalyst selectivity need to be made. So far, only copper-based catalysts have shown efficient conversion of CO2 into the desired multi-carbon (C2+) products. This work explores Cu-based dilute alloys to systematically tune the energy landscape of CO2 electrolysis toward C2+ products. Selection of the dilute alloy components is guided by grand canonical density functional theory simulations using the calculated binding energies of the reaction intermediates CO*, CHO*, and OCCO* dimer as descriptors for the selectivity toward C2+ products. A physical vapor deposition catalyst testing platform is employed to isolate the effect of alloy composition on the C2+/C1 product branching ratio without interference from catalyst morphology or catalyst integration. Six dilute alloy catalysts are prepared and tested with respect to their C2+/C1 product ratio using different electrolyzer environments including selected tests in a 100-cm2 electrolyzer. Consistent with theory, CuAl, CuB, CuGa and especially CuSc show increased selectivity toward C2+ products by making CO dimerization energetically more favorable on the dominant Cu facets, demonstrating the power of using the dilute alloy approach to tune the selectivity of CO2 electrolysis.

Scalable Gas Diffusion Electrode Fabrication for Electrochemical CO2 Reduction Using Physical Vapor Deposition Methods.

Electrochemical CO2 reduction (ECR) promises the replacement of fossil fuels as the source of feedstock chemicals and seasonal storage of renewable energy. While much progress has been made in catalyst development and electrochemical reactor design, few studies have addressed the effect of catalyst integration on device performance. Using a microfluidic gas diffusion electrolyzer, we systematically studied the effect of thickness and the morphology of electron beam (EB) and magnetron-sputtered (MS) Cu catalyst coatings on ECR performance. We observed that EB-Cu outperforms MS-Cu in current density, selectivity, and energy efficiency, with 400 nm thick catalyst coatings performing the best. The superior performance of EB-Cu catalysts is assigned to their faceted surface morphology and sharper Cu/gas diffusion layer interface, which increases their hydrophobicity. Tests in a large-scale zero-gap electrolyzer yielded similar product selectivity distributions with an ethylene Faradaic efficiency of 39% at 200 mA/cm2, demonstrating the scalability for industrial ECR applications.

Evaluating the stability and activity of dilute Cu-based alloys for electrochemical CO2 reduction.

Cu-based catalysts currently offer the most promising route to actively and selectively produce value-added chemicals via electrochemical reduction of CO2 (eCO2R); yet further improvements are required for their wide-scale deployment in carbon mitigation efforts. Here, we systematically investigate a family of dilute Cu-based alloys to explore their viability as active and selective catalysts for eCO2R through a combined theoretical-experimental approach. Using a quantum-classical modeling approach that accounts for dynamic solvation effects, we assess the stability and activity of model single-atom catalysts under eCO2R conditions. Our calculations identify that the presence of eCO2R intermediates, such as CO*, H*, and OH*, may dynamically influence the local catalyst surface composition. Additionally, we identify through binding energy descriptors of the CO*, CHO*, and OCCO* dimer intermediates that certain elements, such as group 13 elements (B, Al, and Ga), enhance the selectivity of C2+ species relative to pure Cu by facilitating CO dimerization. The theoretical work is corroborated by preliminary testing of eCO2R activity and selectivity of candidate dilute Cu-based alloy catalyst films prepared by electron beam evaporation in a zero-gap gas diffusion electrode-based reactor. Of all studied alloys, dilute CuAl was found to be the most active and selective toward C2+ products like ethylene, consistent with the theoretical predictions. We attribute the improved performance of dilute CuAl alloys to more favorable dimerization reaction energetics of bound CO species relative to that on pure Cu. In a broader context, the results presented here demonstrate the power of our simulation framework in terms of rational catalyst design.

The role of klotho in chronic kidney disease.

Chronic kidney disease (CKD) is an inherently systemic disease that refers to a long-term loss of kidney function. The progression of CKD has repercussions for other organs, leading to many kinds of extrarenal complications. Intensive studies are now being undertaken to reveal the risk factors and pathophysiological mechanism of this disease. During the past 20 years, increasing evidence from clinical and basic studies has indicated that klotho, which was initially known as an anti-aging gene and is mainly expressed in the kidney, is significantly correlated with the development and progression of CKD and its complications. Here, we discuss in detail the role and pathophysiological implications of klotho in ion disorders, the inflammation response, vascular calcification, mineral bone disorders, and renal fibrosis in CKD. Based on the pathogenic mechanism of klotho deficiency and klotho decline in urine early in CKD stage 2 and even earlier in CKD stage 1, it is not difficult to understand that soluble klotho can serve as an early and sensitive marker of CKD. Moreover, the prevention of klotho decline by several mechanisms can attenuate renal injuries, retard CKD progression, ameliorate extrarenal complications, and improve renal function. In this review, we focus on the functions and pathophysiological implications of klotho in CKD and its extrarenal complications as well as its potential applications as a diagnostic and/or prognostic biomarker for CKD and as a novel treatment strategy to improve and decrease the burden of comorbidity in CKD.

Nanoporous Copper-Silver Alloys by Additive-Controlled Electrodeposition for the Selective Electroreduction of CO2 to Ethylene and Ethanol.

Electrodeposition of CuAg alloy films from plating baths containing 3,5-diamino-1,2,4-triazole (DAT) as an inhibitor yields high surface area catalysts for the active and selective electroreduction of CO2 to multicarbon hydrocarbons and oxygenates. EXAFS shows the co-deposited alloy film to be homogeneously mixed. The alloy film containing 6% Ag exhibits the best CO2 electroreduction performance, with the Faradaic efficiency for C2H4 and C2H5OH production reaching nearly 60 and 25%, respectively, at a cathode potential of just -0.7 V vs RHE and a total current density of ∼ - 300 mA/cm2. Such high levels of selectivity at high activity and low applied potential are the highest reported to date. In situ Raman and electroanalysis studies suggest the origin of the high selectivity toward C2 products to be a combined effect of the enhanced stabilization of the Cu2O overlayer and the optimal availability of the CO intermediate due to the Ag incorporated in the alloy.

Microarray analysis reveals gene and microRNA signatures in diabetic kidney disease.

The current study aimed to identify therapeutic gene and microRNA (miRNA) biomarkers for diabetic kidney disease (DKD). The public expression profile GSE30122 was used. Following data preprocessing, the limma package was used to select differentially-expressed genes (DEGs) in DKD glomeruli samples and tubuli samples and they were compared with corresponding controls. Then overlapping DEGs in glomeruli and tubuli were identified and enriched analysis was performed. In addition, protein­protein interaction (PPI) network analysis as well as sub­network analysis was conducted. miRNAs of the overlapping DEGs were investigated using WebGestal. A total of 139 upregulated and 28 downregulated overlapping DEGs were selected, which were primarily associated with pathways involved in extracellular matrix (ECM)­receptor interactions and cytokine­cytokine receptor interactions. CD44, fibronectin 1, C­C motif chemokine ligand 5 and C­X­C motif chemokine receptor 4 were four primary nodes in the PPI network. miRNA (miR)­17­5p, miR­20a and miR­106a were important and nuclear receptor subfamily 4 group A member 3 (NR4A3), protein tyrosine phosphatase, receptor type O (PTPRO) and Kruppel like factor 9 (KLF9) were all predicted as target genes of the three miRNAs in the integrated miRNA­target network. Several genes were identified in DKD, which may be involved in pathways such as ECM­receptor interaction and cytokine­cytokine receptor interaction. Three miRNAs may also be used as biomarkers for therapy of DKD, including miR­17­5p, miR­20a and miR­106a, with the predicted targets of NR4A3, PTPRO and KLF9.

Non-Aqueous Primary Li-Air Flow Battery and Optimization of its Cathode through Experiment and Modeling.

A primary Li-air battery has been developed with a flowing Li-ion free ionic liquid as the recyclable electrolyte, boosting power capability by promoting superoxide diffusion and enhancing discharge capacity through separately stored discharge products. Experimental and computational tools are used to analyze the cathode properties, leading to a set of parameters that improve the discharge current density of the non-aqueous Li-air flow battery. The structure and configuration of the cathode gas diffusion layers (GDLs) are systematically modified by using different levels of hot pressing and the presence or absence of a microporous layer (MPL). These experiments reveal that the use of thinner but denser MPLs is key for performance optimization; indeed, this leads to an improvement in discharge current density. Also, computational results indicate that the extent of electrolyte immersion and porosity of the cathode can be optimized to achieve higher current density.

Mus musculus-microRNA-449a ameliorates neuropathic pain by decreasing the level of KCNMA1 and TRPA1, and increasing the level of TPTE.

Neuropathic pain is a nerve disorder characterized by the dysregulation of ion channels in dorsal root ganglion (DRG) neurons. MicroRNAs (miRs) may be associated with the molecular mechanisms underlying the altered levels of ion channels; however, the molecular mechanisms remain widely unknown. To investigate these mechanisms, the present study conducted a genomic analysis of miR between a unilateral spared nerve injury (SNI) model and sham control. Differentially expressed miRs between the SNI and sham groups were selected for transfection of DRG cells, a polymerase chain reaction (PCR) array analysis was subsequently performed. A total of three significantly differently expressed genes were selected from the results of the PCR array and further analyzed by reverse transcription­quantitative PCR. Genomic analysis revealed that Mus musculus miR­449a (mmu­miR­449a) was reduced in the SNI groups compared with the sham controls. The PCR array indicated that mmu­miR­449a­transfection reduced the mRNA expression levels of transient receptor potential cation channel subfamily A member 1 (TRPA1), and calcium­activated potassium channel subunit α­1 (KCNMA1) and increased the level of transmembrane phosphatase with tension homology (TPTE) in the DRG cells (P<0.05). qRT­PCR analysis further indicated that mmu­miR­449a transfection caused similar alterations in the mRNA expression levels of TRPA1, KCNMA1 and TPTE in DRG cells, respectively (P<0.05). Therefore, mmu­miR­449a may ameliorate neuropathic pain by decreasing the activity of the channel proteins TRPA1 and KCNMA1 and increasing the levels of TPTE. mmu­miR­449a may be a potential therapeutic molecule for the alleviation of neuropathic pain.

Electroreduction of Carbon Dioxide to Hydrocarbons Using Bimetallic Cu-Pd Catalysts with Different Mixing Patterns.

Electrochemical conversion of CO2 holds promise for utilization of CO2 as a carbon feedstock and for storage of intermittent renewable energy. Presently Cu is the only metallic electrocatalyst known to reduce CO2 to appreciable amounts of hydrocarbons, but often a wide range of products such as CO, HCOO-, and H2 are formed as well. Better catalysts that exhibit high activity and especially high selectivity for specific products are needed. Here a range of bimetallic Cu-Pd catalysts with ordered, disordered, and phase-separated atomic arrangements (Cuat:Pdat = 1:1), as well as two additional disordered arrangements (Cu3Pd and CuPd3 with Cuat:Pdat = 3:1 and 1:3), are studied to determine key factors needed to achieve high selectivity for C1 or C2 chemicals in CO2 reduction. When compared with the disordered and phase-separated CuPd catalysts, the ordered CuPd catalyst exhibits the highest selectivity for C1 products (>80%). The phase-separated CuPd and Cu3Pd achieve higher selectivity (>60%) for C2 chemicals than CuPd3 and ordered CuPd, which suggests that the probability of dimerization of C1 intermediates is higher on surfaces with neighboring Cu atoms. Based on surface valence band spectra, geometric effects rather than electronic effects seem to be key in determining the selectivity of bimetallic Cu-Pd catalysts. These results imply that selectivities to different products can be tuned by geometric arrangements. This insight may benefit the design of catalytic surfaces that further improve activity and selectivity for CO2 reduction.

A metal-free electrocatalyst for carbon dioxide reduction to multi-carbon hydrocarbons and oxygenates.

Electroreduction of carbon dioxide into higher-energy liquid fuels and chemicals is a promising but challenging renewable energy conversion technology. Among the electrocatalysts screened so far for carbon dioxide reduction, which includes metals, alloys, organometallics, layered materials and carbon nanostructures, only copper exhibits selectivity towards formation of hydrocarbons and multi-carbon oxygenates at fairly high efficiencies, whereas most others favour production of carbon monoxide or formate. Here we report that nanometre-size N-doped graphene quantum dots (NGQDs) catalyse the electrochemical reduction of carbon dioxide into multi-carbon hydrocarbons and oxygenates at high Faradaic efficiencies, high current densities and low overpotentials. The NGQDs show a high total Faradaic efficiency of carbon dioxide reduction of up to 90%, with selectivity for ethylene and ethanol conversions reaching 45%. The C2 and C3 product distribution and production rate for NGQD-catalysed carbon dioxide reduction is comparable to those obtained with copper nanoparticle-based electrocatalysts.

A Gross-Margin Model for Defining Technoeconomic Benchmarks in the Electroreduction of CO2.

We introduce a gross-margin model to evaluate the technoeconomic feasibility of producing different C1 -C2 chemicals such as carbon monoxide, formic acid, methanol, methane, ethanol, and ethylene through the electroreduction of CO2 . Key performance benchmarks including the maximum operating cell potential (Vmax ), minimum operating current density (jmin ), Faradaic efficiency (FE), and catalyst durability (tcatdur ) are derived. The Vmax values obtained for the different chemicals indicate that CO and HCOOH are the most economically viable products. Selectivity requirements suggest that the coproduction of an economically less feasible chemical (CH3 OH, CH4 , C2 H5 OH, C2 H4 ) with a more feasible chemical (CO, HCOOH) can be a strategy to offset the Vmax requirements for individual products. Other performance requirements such as jmin and tcatdur are also derived, and the feasibility of alternative process designs and operating conditions are evaluated.

Effects of Patient-Controlled Epidural Analgesia and Patient-Controlled Intravenous Analgesia on Analgesia in Patients Undergoing Spinal Fusion Surgery.

We compared the outcomes of patient-controlled epidural analgesia (PCEA) and patient-controlled intravenous analgesia (PCIA) in analgesia after spinal fusion surgery. A total of 120 patients who underwent spinal fusion surgeries between April 2013 and April 2015 at Shaanxi Provincial People's Hospital were selected for this study based on defined inclusion criteria. All patients were randomly divided into 2 groups before surgery: PCEA group (n = 65) and PCIA group (n = 55). Visual analog scales (VAS) were used to evaluate the degree of pain. Besides, the active and passive activities of patients during 1- to 3-day recovery period after surgery were recorded. Verbal rating scales were used to measure pain levels after surgery and after surgery. Adverse effects of PCEA and PCIA were monitored, which included nausea, vomiting, pruritus, drowsiness, respiratory depression, and headache. Our results showed no statistically significant differences between PCEA and PCIA in sex ratio, age, height, weight, American Society of Anesthesiologists level, surgery time, number of fusion section, surgery methods, and duration of anesthesia (all P > 0.05). The PCEA group was associated with significantly lower VAS scores, compared with the PCIA group, at 3, 6, 12, 24, and 48-hour postsurgery (all P < 0.05) when surgery-associated pain is expected to be intense. Also, compared with the PCIA group, the PCEA group showed higher frequency of recovery activities on first and second day postsurgery (all P < 0.05). The overall patient satisfaction level of analgesia in the PCEA group was significantly higher than in the PCIA group (P < 0.05). Moreover, the incidence of hypopiesia and skin itching in the PCIA group was higher than in the PCEA group (all P < 0.05). Finally, drowsiness and headache were markedly lower in the PCIA group after surgery, compared with the PCEA group, and this difference was statistically significant (all P < 0.05). Our results provide strong evidence that PCEA exhibits significantly greater efficacy than PCIA for pain management after spinal fusion surgery, with lower VAS scores, higher frequency of recovery activities, and overall higher satisfaction level.

The effect of electrolyte composition on the electroreduction of CO2 to CO on Ag based gas diffusion electrodes.

The electroreduction of CO2 to C1-C2 chemicals can be a potential strategy for utilizing CO2 as a carbon feedstock. In this work, we investigate the effect of electrolytes on the electroreduction of CO2 to CO on Ag based gas diffusion electrodes. Electrolyte concentration was found to play a major role in the process for the electrolytes (KOH, KCl, and KHCO3) studied here. Several fold improvements in partial current densities of CO (jCO) were observed on moving from 0.5 M to 3.0 M electrolyte solution independent of the nature of the anion. jCO values as high as 440 mA cm(-2) with an energy efficiency (EE) of ≈ 42% and 230 mA cm(-2) with EE ≈ 54% were observed when using 3.0 M KOH. Electrochemical impedance spectroscopy showed that both the charge transfer resistance (Rct) and the cell resistance (Rcell) decreased on moving from a 0.5 M to a 3.0 M KOH electrolyte. Anions were found to play an important role with respect to reducing the onset potential of CO in the order OH(-) (-0.13 V vs. RHE) < HCO3(-) (-0.46 V vs. RHE) < Cl(-) (-0.60 V vs. RHE). A decrease in Rct upon increasing electrolyte concentration and the effect of anions on the cathode can be explained by an interplay of different interactions in the electrical double layer that can either stabilize or destabilize the rate limiting CO2˙(-) radical. EMIM based ionic liquids and 1 : 2 choline Cl urea based deep eutectic solvents (DESs) have been used for CO2 capture but exhibit low conductivity. Here, we investigate if the addition of KCl to such solutions can improve conductivity and hence jCO. Electrolytes containing KCl in combination with EMIM Cl, choline Cl, or DESs showed a two to three fold improvement in jCO in comparison to those without KCl. Using such mixtures can be a strategy for integrating the process of CO2 capture with CO2 conversion.

Comparison of pain relief between patient-controlled epidural analgesia and patient-controlled intravenous analgesia for patients undergoing spinal fusion surgeries.

INTRODUCTION: This meta-analysis aimed to compare the postoperative analgesic effects of patient-controlled epidural analgesia (PCEA) and patient-controlled intravenous analgesia (PCIA) for patients undergoing spinal fusion surgeries. METHOD: Relevant articles were identified using computerized and manual search strategies. Statistical analyses were undertaken by the CMA 2.0 statistical software. RESULTS: Nine cohort studies with a total of 436 patients undergoing spinal fusion surgeries were incorporated in the present meta-analysis. There were significant differences between the PCEA and PCIA groups in the visual analogue scale score of patients undergoing spinal fusion [standardized mean difference = 0.27, 95 % confidence interval (95 % CI) = 0.070-0.470, P = 0.008]. However, no obvious difference was observed in the rate of side effects between the PCIA and PCEA groups (side effects: odds ratio = 0.957, 95 % CI = 0.536-1.708, P = 0.882). CONCLUSION: Our findings suggested that PCEA may be more effective in relieving pain than PCIA for patients undergoing spinal fusion surgeries.

Transumbilical single-incision laparoscopic versus conventional laparoscopic upper pole heminephroureterectomy for children with duplex kidney: a retrospective comparative study.

OBJECTIVE: To present our experience regarding transumbilical single-incision laparoscopic heminephroureterectomy (SILH) in children with duplex kidney anomalies, and to investigate its feasibility and safety compared with those of conventional laparoscopic heminephroureterectomy (CLH). MATERIALS AND METHODS: A matched-pair study comparing 34 SILHs and 34 CLHs performed by a single surgeon from 2007 to 2013 was presented. All SILHs were performed through a 2-cm periumbilical incision by using the port-access system, whereas CLH cases were performed via a transperitoneal 3-port approach. The groups were matched for age, gender, weight, laterality, and surgical indication of the patients. Data including demographics and perioperative and short-term outcomes of the patients were retrospectively compared. RESULTS: The 2 groups were comparable in demographics, and surgical indications of the patients (P >.05). No significant difference was observed between SILH and CLH cases in terms of median operative time (105 vs 97 minutes; P = .06), estimated blood loss (22 vs 25 mL; P = .91), interval for oral intake (12 vs 12 hours; P = .69), analgesic requirement (9 vs 6 cases; P = .38), transfusion rate (0% for both; P = 1.00), complication rate (2.9% vs 0%; P = 1.00), postoperative hospital stay (5.0 vs 4.5 days; P = .59), and renal functional loss of the operated side at 3 months after surgery (5.4% vs 5.2%; P = .60). CONCLUSION: SILH is feasible and safe in the hands of an experienced pediatric laparoscopic surgeon. Although the outcomes were comparable, better subjective cosmetic results of SILH were achieved.

Early experience of using transumbilical multi-stab laparoscopic pyeloplasty for infants younger than 3 months.

OBJECTIVE: Minimally invasive surgery is increasingly being adopted in pediatric urology practice. The aim of this study is to investigate the feasibility and the safety of transumbilical multi-stab laparoscopic pyeloplasty (TMLP) as a treatment for infants younger than 3 months with severe hydronephrosis. METHODS: We retrospectively reviewed 63 infants younger than 3 months with severe hydronephrosis who underwent TMLP from June 2010 to March 2013. The operative indications included: 1) prenatal diagnosis of hydronephrosis with anteroposterior renal pelvic diameter greater than 3 cm and Society of Fetal Urology (SFU) Grade 4 hydronephrosis; 2) ipsilateral differential renal function being less than 40%. Patients were followed up with physical examinations, ultrasound and radionuclide scans. RESULTS: The operations were successfully performed in all 63 patients. There was no conversion, no requirement of additional trocar placement and no intraoperative complication. The median age was 54 (47-87) days. The median operative time was 75 (53-118) minutes. The patients were followed up for 12 (6-36) months. The anastomoses were proved to be patent and the renal parenchymal thickness increased. The renal pelvic anteroposterior diameters were reduced and the renal functions were improved (p < 0.01). In addition, the scars were barely noticeable. CONCLUSIONS: TMLP for infants younger than 3 months with severe hydronephrosis is feasible, safe and minimally invasive. The cosmetic results are excellent.

Silver supported on titania as an active catalyst for electrochemical carbon dioxide reduction.

Although significant research efforts have focused on the exploration of catalysts for the electrochemical reduction of CO2 , considerably fewer reports have described how support materials for these catalysts affect their performance, which includes their ability to reduce the overpotential, and/or to increase the catalyst utilization and selectivity. Here Ag nanoparticles supported on carbon black (Ag/C) and on titanium dioxide (Ag/TiO2 ) were synthesized. In a flow reactor, 40 wt % Ag/TiO2 exhibited a twofold higher current density for CO production than 40 wt % Ag/C. Faradaic efficiencies of the 40 wt % Ag/TiO2 catalyst exceeded 90 % with a partial current density for CO of 101 mA cm(-2) ; similar to the performance of unsupported Ag nanoparticle catalysts (AgNP) but at a 2.5 times lower Ag loading. A mass activity as high as 2700 mA mgAg (-1) cm(-2) was achieved. In cyclic voltammetry tests in a three-electrode cell, Ag/TiO2 exhibited a lower overpotential for CO2 reduction than AgNP, which, together with other data, suggests that TiO2 stabilizes the intermediate and serves as redox electron carrier to assist CO2 reduction while Ag assists in the formation of the final product, CO.

Nitrogen-based catalysts for the electrochemical reduction of CO2 to CO.

The synthesis and application of carbon-supported, nitrogen-based organometallic silver catalysts for the reduction of CO(2) is studied using an electrochemical flow reactor. Their performance toward the selective formation of CO is similar to the performance achieved when using Ag as the catalyst, but comparatively at much lower silver loading. Faradaic efficiencies of the organometallic catalyst are higher than 90%, which are comparable to those of Ag. Furthermore, with the addition of an amine ligand to Ag/C, the partial current density for CO increases significantly, suggesting a possible co-catalyst mechanism. Additional improvements in activity and selectivity may be achieved as greater insight is obtained on the mechanism of CO(2) reduction and on how these complexes assemble on the carbon support.