Advanced Electrolyte Formula for Robust Operation of Vanadium Redox Flow Batteries at Elevated Temperatures.

Insufficient thermal stability of vanadium redox flow battery (VRFB) electrolytes at elevated temperatures (>40 °C) remains a challenge in the development and commercialization of this technology, which otherwise presents a broad range of technological advantages for the long-term storage of intermittent renewable energy. Herein, a new concept of combined additives is presented, which significantly increases thermal stability of the battery, enabling safe operation to the highest temperature (50 °C) tested to date. This is achieved by combining two chemically distinct additives-inorganic ammonium phosphate and polyvinylpyrrolidone (PVP) surfactant, which collectively decelerate both protonation and agglomeration of the oxo-vanadium species in solution and thereby significantly suppress detrimental formation of precipitates. Specifically, the precipitation rate is reduced by nearly 75% under static conditions at 50° C. This improvement is reflected in the robust operation of a complete VRFB device for over 300 h of continuous operation at 50 °C, achieving an impressive 83% voltage efficiency at 100 mA cm‒2 current density, with no precipitation detected in either the electrode/flow-frame or electrolyte tank.

Spinal Anesthesia Prior to Laparoscopic Hysterectomy Resulted in Decreased Postoperative Pain and Opioid Use.

Study Objective: To determine if a pre-operative morphine/bupivacaine spinal injection prior to laparoscopic hysterectomy reduced postoperative pain and resulted in less opioid consumption during the hospital stay. Methods: A retrospective cohort study (Canadian Task Force Classification II-2) was conducted at a single institution regional referral center (community hospital) in North Carolina. Three hundred nineteen patients met criteria for inclusion: 192 received spinal anesthesia and 127 did not. Baseline demographics were similar between the two groups. Median pain scores were significantly lower in the treatment than the control group on day of surgery (DOS) (2 vs. 6; P < 0.001) and postoperative day 1 (POD1) (2 vs. 4; P < 0.001). Results: Primary outcomes were pain scores on DOS and POD1 and inpatient opioid use. Pain scores were obtained using the 0 to 10 Numerical Rating Scale. Opioids were converted to oral morphine milliequivalents (OME). Median opioid use was also significantly lower in the treatment than the control group on DOS (0 vs. 15.00 OME; P < 0.001) and POD1 (0 vs. 7.5 OME; P < 0.001). Median length of stay between the groups was not significantly different. Conclusion: Pre-operative morphine spinal injection for laparoscopic hysterectomy led to significantly lower pain scores and inpatient opioid consumption. Pre-operative spinal anesthesia for benign laparoscopic hysterectomy appears helpful for enhancing the postoperative experience.

A Survey of Catalytic Materials for Ammonia Electrooxidation to Nitrite and Nitrate.

Studies of the ammonia oxidation reaction (AOR) for the synthesis of nitrite and nitrate (NO2/3 - ) have been limited to a small number of catalytic materials, majorly Pt based. As the demand for nitrate-based products such as fertilisers continues to grow, exploration of alternative catalysts is needed. Herein, 19 metals immobilised as particles on carbon fibre electrodes were tested for their catalytic activity for the ammonia electrooxidation to NO2/3 - under alkaline conditions (0.1 m KOH). Nickel-based electrodes showed the highest overall NO2/3 - yield with a rate of 5.0±1.0 nmol s-1 cm-2 , to which nitrate contributed 62±8 %. Cu was the only catalyst that enabled formation of nitrate, at a rate of 1.0±0.4 nmol s-1 cm-2 , with undetectable amounts of nitrite produced. Previously unexplored in this context, Fe and Ag also showed promise and provided new insights into the mechanisms of the process. Ag-based electrodes showed strong indications of activity towards NH3 oxidation in electrochemical measurements but produced relatively low NO2/3 - yields, suggesting the formation of alternate oxidation products. NO2/3 - production over Fe-based electrodes required the presence of dissolved O2 and was more efficient than with Ni on longer timescales. These results highlight the complexity of the AOR mechanism and provide a broad set of catalytic activity and nitrate versus nitrite yield data, which might guide future development of a practical process for the distributed sustainable production of nitrates and nitrites at low and medium scales.

Metallic Inverse Opal Frameworks as Catalyst Supports for High-Performance Water Electrooxidation.

High intrinsic activity of oxygen evolution reaction (OER) catalysts is often limited by their low electrical conductivity. To address this, we introduce copper inverse opal (IO) frameworks offering a well-developed network of interconnected pores as highly conductive high-surface-area supports for thin catalytic coatings, for example, the extremely active but poorly conducting nickel-iron layered double hydroxides (NiFe LDH). Such composites exhibit significantly higher OER activity in 1 m KOH than NiFe LDH supported on a flat substrate or deposited as inverse opals. The NiFe LDH/Cu IO catalyst enables oxygen evolution rates of 100 mA cm-2 (727±4 A gcatalyst -1 ) at an overpotential of 0.305±0.003 V with a Tafel slope of 0.044±0.002 V dec-1 . This high performance is achieved with 2.2±0.4 µm catalyst layers, suggesting compatibility of the inverse-opal-supported catalysts with membrane electrolyzers, in contrast to similarly performing 103 -fold thicker electrodes based on foams and other substrates.

Additive-Free Electrophoretic Deposition of Graphene Quantum Dots Thin Films.

The electrophoretic deposition (EPD) of graphene-based materials on transparent substrates is highly potential for many applications. Several factors can determine the yield of the EPD process, such as applied voltage, deposition time and particularly the presence of dispersion additives (stabilisers) in the suspension solution. This study presents an additive-free EPD of graphene quantum dot (GQD) thin films on an indium tin oxide (ITO) glass substrate and studies the deposition mechanism with the variation of the applied voltage (10-50 V) and deposition time (5-25 min). It is found that due to the small size (≈3.9 nm) and high content of deprotonated carboxylic groups, the GQDs form a stable dispersion (zeta-potential of about -35 mV) without using additives. The GQD thin films can be deposited onto ITO with optimal surface morphology at 30 V in 5 min (surface roughness of approximately (3.1±1.3) nm). In addition, as-fabricated GQD thin films also possess some interesting physico-optical properties, such as a double-peak photoluminescence at about λ=417 and 439 nm, with approximately 98 % visible transmittance. This low-cost and eco-friendly GQD thin film is a promising material for various applications, for example, transparent conductors, supercapacitors and heat conductive films in smart windows.

Equilibrium and Dynamic Absorption of Electrolyte Species in Cation/Anion Exchange Membranes of Vanadium Redox Flow Batteries.

Vanadium redox flow batteries (VRFBs) rely on ion exchange membranes (IEMs) to separate the positive and negative compartments while maintaining electrical neutrality of the cell, by allowing the transport of ionic charge carriers. Cation exchange membranes (CEMs) and anion exchange membranes (AEMs), the two principal types of IEM, have both been employed in VRFBs. The performance of these IEMs can be influenced by the absorption of species from the electrolyte. In this study, a typical commercial CEM (Nafion 117) and AEM (FAP 450), were examined with respect to vanadium uptake, after exposure to electrolyte at different states of charge. The two types of membrane were found to behave very differently, with the AEM showing very high selectivity for VV , which resulted in a significant increase in area-specific resistivity. In contrast, the CEM absorbed VII more strongly than vanadium in other oxidation states. These findings are essential for the development of an effective membrane for VRFB applications.

Female Sex Hormones Activate Human Endogenous Retrovirus Type K Through the OCT4 Transcription Factor in T47D Breast Cancer Cells.

Female sex hormones, the octamer-binding transcription factor 4 (OCT4), and human endogenous retroviruses (HERVs) are all involved in the development of breast cancer. However, whether there are cross talks between these factors to promote breast cancer is still unknown. Using the T47D human breast cancer cell line, we have found that estradiol and progesterone synergistically activate HERV-K through nuclear receptors. The progesterone receptor (isoform B) binds a progesterone-response element (PRE) in a long terminal repeat (LTR5HS) of HERV-K. There is another transcription factor-binding element in the LTR, the octamer motif, which is required for the hormones to activate gene transcription downstream of the LTR. Gel shift assays and co-immunoprecipitation indicate that the progesterone receptor (PR) and the OCT4 transcription factor interact on the protein level. Methylation of the PRE enhances binding of the PR. These findings help to elucidate the previously unknown cross talks among the sex hormones, OCT4, and HERVs in contributing to breast cancer proliferation and tumorigenesis, which may be useful in guiding further development of cancer therapies.

Enhanced ferromagnetism of ZnO@Co/Ni hybrid core@shell nanowires grown by electrochemical deposition method.

The hybrid structure of ZnO NWs with the presence of different dopants recently has drawn many interests from researchers due to the possibility to integrate multiple functionalities into one single structure. In this article, we investigated the morphology, crystal structure and ferromagnetism of the ZnO@Co/Ni hybrid core@shell NWs prepared by a facile electrochemical deposition method. The results show that a thin layer of Ni and Co coated on the surface of ZnO NWs (confirmed by XRD, EDS, TEM and Raman scattering) can create a significant improvement of ferromagnetic property in such hybrid core@shell NWs. In which, for the coating time of 10, 15, 20 min, the value of M s is around 0.67, 0.88 and 2.56 emu g-1 for ZnO@Co NWs, and about 0.013, 0.022 and 0.031 emu g-1 for ZnO@Ni NWs, respectively, in comparison with the number of 0.016 emu g-1 for pure ZnO NWs. Interestingly, we also found the temperature dependence of ferromagnetism of such Co/Ni coated ZnO NWs. These results reveal the possibility to employ such hybrid core@shell NWs for many applications, e.g. spin field effect transistors.

Success of Immunosuppressive Treatments in Patients with Chronic Graft-versus-Host Disease.

Moderate to severe chronic graft-versus-host disease (GVHD) is treated with potent immunosuppressive therapy (IST) to modulate the allo-immune response, control symptoms, and prevent further organ damage. We sought to understand the types of treatments used in clinical practice and the likelihood of successful treatment associated with each. A chart review was performed for 250 adult patients at Fred Hutchinson Cancer Research Center enrolled in a prospective observational study. After a median follow-up of 5.6 years for survivors, approximately one-third were still on IST (of whom half were on fourth or greater line of therapy), one-third were alive and off IST, and one-third had relapsed or died. Approximately half of survivors stopped all IST at least once, although half of these restarted IST after a median of 3.4 months (interquartile range, 2.3 to 8.0) off therapy. Successful discontinuation of IST for at least 9 months was associated with myeloablative conditioning (P = .04), more years since transplant (P = .009), and lack of oral (P < .001) and skin (P = .049) involvement compared with those who had to restart IST. We conclude that patients with chronic GVHD usually receive multiple lines and years of IST, with only a third off IST, alive, and free of malignancy at 5 years after chronic GVHD diagnosis. Patients stopping IST should be cautioned to self-monitor and continue close medical follow-up, especially for 3 to 6 months after stopping IST.

The ABO Histo-Blood Group and AKI in Critically Ill Patients with Trauma or Sepsis.

BACKGROUND AND OBJECTIVE: ABO blood types are determined by antigen modifications on glycoproteins and glycolipids and associated with altered plasma levels of inflammatory and endothelial injury markers implicated in AKI pathogenesis. We sought to determine the association of ABO blood types with AKI risk in critically ill patients with trauma or sepsis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted two prospective cohort studies at an urban, academic, level I trauma center and tertiary referral center; 497 patients with trauma admitted to the surgical intensive care unit between 2005 and 2010 with an injury severity score >15 and 759 patients with severe sepsis admitted to the medical intensive care unit between 2008 and 2013 were followed for 6 days for the development of incident AKI. AKI was defined by Acute Kidney Injury Network creatinine and dialysis criteria. RESULTS: Of 497 patients with trauma, 134 developed AKI (27%). In multivariable analysis, blood type A was associated with higher AKI risk relative to type O among patients of European descent (n=229; adjusted risk, 0.28 versus 0.14; risk difference, 0.14; 95% confidence interval, 0.03 to 0.24; P=0.02). Of 759 patients with sepsis, AKI developed in 326 (43%). Blood type A again conferred higher AKI risk relative to type O among patients of European descent (n=437; adjusted risk, 0.53 versus 0.40; risk difference, 0.14; 95% confidence interval, 0.04 to 0.23; P=0.01). Findings were similar when analysis was restricted to those patients who did not develop acute respiratory distress syndrome or were not transfused. We did not detect a significant association between blood type and AKI risk among individuals of African descent in either cohort. CONCLUSIONS: Blood type A is independently associated with AKI risk in critically ill patients with trauma or severe sepsis of European descent, suggesting a role for ABO glycans in AKI susceptibility.