Electrode Treatments for Redox Flow Batteries: Translating Our Understanding from Vanadium to Aqueous-Organic.

Redox flow batteries (RFBs) are a promising technology for long-duration energy storage; but they suffer from inefficiencies in part due to the overvoltages at the electrode surface. In this work, more than 70 electrode treatments are reviewed that are previously shown to reduce the overvoltages and improve performance for vanadium RFBs (VRFBs), the most commercialized RFB technology. However, identifying treatments that improve performance the most and whether they are industrially implementable is challenging. This study attempts to address this challenge by comparing treatments under similar operating conditions and accounting for the treatment process complexity. The different treatments are compared at laboratory and industrial scale based on criteria for VRFB performance, treatment stability, economic feasibility, and ease of industrial implementation. Thermal, plasma, electrochemical oxidation, CO2 treatments, as well as Bi, Ag, and Cu catalysts loaded on electrodes are identified as the most promising for adoption in large scale VRFBs. The similarity in electrode treatments for aqueous-organic RFBs (AORFBs) and VRFBs is also identified. The need of standardization in RFBs testing along with fundamental studies to understand charge transfer reactions in redox active species used in RFBs moving forward is emphasized.

Outcomes of robotic lobectomy for non-small cell lung cancer in a National Cancer Institute-Comprehensive Cancer Center vs. National Cancer Database.

Background: There continues to be a rise in the proportion of resectable non-small cell lung cancer (NSCLC) with the recent expansion of criteria for low-dose lung cancer screening. These are increasingly being treated with minimally invasive techniques. Our study aims to compare outcomes of robotic lobectomy (RL) for NSCLC at a National Cancer Institute-designated Comprehensive Cancer Center (NCI-CCC) to those of open lobectomy (OL), video-assisted thoracoscopic lobectomy (VL), or RL as reported in the National Cancer Database (NCDB). Methods: The first 1,021 patients with NSCLC who underwent RL between 2010 and 2020 were matched with peers from the NCDB who had OL, VL, or RL. Matching was performed based on a propensity score calculated by logistic regression using multiple variables. Surgical outcomes included numbers of examined lymph nodes, performance of mediastinal lymphadenectomy, length of stay (LOS), and 30-day mortality. Kaplan-Meier curves and overall survival (OS) were analyzed using log-rank tests. Results: Most common postoperative complications were persistent air leak, atrial fibrillation, and pneumonia. Median LOS was 4 days, and the 30-day mortality rate was 1% (n=10/1,021). Compared to NCDB patients who underwent OL, NCI-CCC patients had a higher mean number of retrieved lymph nodes (P=0.001), higher rate of mediastinal lymphadenectomy (P<0.001), and shorter median LOS (4 vs. 6 days; P<0.001). There was no difference in 30-day mortality (P=0.176). Kaplan-Meier analyses showed no differences in median OS (log-rank P=0.953) or 5-year OS (P=0.774). Compared to NCDB VL, NCI-CCC patients had a higher nodal yield (P<0.001), higher rates of mediastinal lymphadenectomy (P<0.001), and lower conversion rates (4.1% vs. 13.8%, P<0.001). There were no differences in 30-day mortality (P=0.379) or in median LOS (P=0.351). Kaplan-Meier analyses showed no differences in median OS (P=0.720) or 5-year OS (P=0.735). NCI-CCC patients were also matched with NCDB RL patients and had a higher nodal yield (P<0.001), higher rates of mediastinal lymphadenectomy (P<0.001), and lower conversion rates (4.1% vs. 9.5%; P <0.001). There were no differences in 30-day mortality (P=0.899) or in median LOS (P=0.252). Kaplan-Meier analyses showed no differences in median OS (P=0.484) or 5-year OS (P=0.524). Conclusions: RL for NSCLC performed in an NCI-CCC appears to have improved perioperative outcomes with comparable long-term OS compared to national benchmarks in OL and VL.

Atomically Dispersed Manganese on Graphene Nanosheets as Biocompatible Nanozyme for Glutathione Detection in Liver Tissue Lysate Using Microfluidic Paper-based Analytical Devices.

Recently, single atom catalysts (SACs) featuring M-Nx (M = metal) active sites on carbon support have drawn considerable attention due to their promising enzyme-like catalytic properties. However, typical synthesis methods of SACs often involve energy-intensive carbonization processes. Herein, we report a facile one-pot, low-temperature, wet impregnation method to fully utilize M-N4 sites of manganese phthalocyanine (MnPc) by decorating molecular MnPc over the sheets of graphene nanoplatelets (GNP). The synthesized MnPc@GNP exhibits remarkable peroxidase-mimic catalytic activity toward the oxidation of chromogenic 3,3',5,5'-tetramethylbenzidine (TMB) substrate owing to the efficient utilization of atomically dispersed Mn and the high surface-to-volume ratio of the porous catalyst. A nanozyme-based colorimetric sensing probe is developed to detect important biomarker glutathione (GSH) within only 5 min in solution phase based on the ability of GSH to effectively inhibit the TMB oxidation. The high sensitivity and selectivity of the developed colorimetric assay enable us to quantitatively determine GSH concentration in different biological fluids. This work, for the first time, reports a rapid MnPc@GNP nanozyme-based colorimetric assay in the solid substrate by fabricating microfluidic paper-based analytical devices (µPADs). GSH is successfully detected on the fabricated µPADs coated with only 6.0 µg of nanozyme containing 1.6 nmol of Mn in the linear range of 0.5-10 µM with a limit of detection of 1.23 µM. This work also demonstrates the quantitative detection of GSH in mice liver tissue lysate using µPADs, which paves the way to develop µPADs for point-of-care testing.

Risk of adenocarcinoma in patients with a suspicious ground-glass opacity: a retrospective review.

Background: Both primary lung adenocarcinoma and benign processes can have a ground-glass opacity (GGO) appearance on imaging. This study evaluated the incidence of and risk factors for malignancy in a diverse cohort of patients who underwent resection of a GGO suspicious for lung cancer. Methods: All patients who underwent resection of a pulmonary nodule with a GGO component and suspected to be primary lung cancer at a single institution from 2001-2017 were retrospectively reviewed. Risk factors for malignancy were evaluated using multivariable logistic regression analysis that included nodule size, age, sex, and race as potential predictors. Results: The incidence of pulmonary adenocarcinoma in the 243 patients who met inclusion criteria was 86% (n=208). The most common pathologic findings in 35 patients with a benign pathology was granulomatous inflammation (n=14, 40%). Risk factors for adenocarcinoma in multivariable logistic regression were age [odds ratio (OR) 1.06, P=0.003], GGO size (OR 2.76, P<0.001), female sex (OR 4.47, P=0.002), and Asian race (OR 8.35, P=0.002). In this cohort, adenocarcinoma was found in 100% (44/44) of Asian females, 86% (25/29) of Asian males, 84% (98/117) of non-Asian females, and 77% (41/53) of non-Asian males. Conclusions: The likelihood of adenocarcinoma in lung nodules with a ground-glass component is influenced by sex and race. Asian females with a GGO have a much higher likelihood of having adenocarcinoma than men and non-Asians. This data can be used when deciding whether to pursue nodule resection or surveillance in a patient with a GGO.

A Comparison of Implants Used in Open-Door Laminoplasty: Structural Rib Allografts Versus Metallic Miniplates.

STUDY DESIGN: A retrospective case-controlled study. SUMMARY OF BACKGROUND DATA: Open-door laminoplasty has been successfully used to address cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament. Two common implants include rib allograft struts and metallic miniplates. OBJECTIVE: The goals of this study were to compare outcomes, complications, and costs associated with these 2 implants. METHODS: A retrospective review was done on 51 patients with allograft struts and 55 patients with miniplates. Primary outcomes were neck visual analog scale (VAS) pain scores and Nurick scores. Secondary outcomes included length of the procedure, estimated blood loss, rates of complications, and the direct costs associated with the surgery and inpatient hospitalization. RESULTS: There were no differences in demographic characteristics, diagnoses, comorbidities, and preoperative outcome scores between the 2 treatment groups. Mean follow-up was 27 months. The postoperative neck VAS scores and Nurick scores improved significantly from baseline to final follow-up for both groups, but there was no difference between the 2 groups. The average length of operation (161 vs. 136 min) and number of foraminotomies (2.7 vs. 1.3) were higher for the allograft group (P=0.007 and 0.0001, respectively). Among the miniplate group, there was no difference in complications but a trend for less neck pain for patients treated without hard collar at final follow-up (1.8 vs. 2.3, P=0.52). The mean direct costs of hospitalization for the miniplate group were 15% higher. CONCLUSIONS: Structural rib allograft struts and metallic miniplates result in similar improvements in pain and functional outcome scores with no difference in the rate of complications in short-term follow-up. Potential benefits of using a plate include shorter procedure length and less need for postoperative immobilization. When costs of bracing and operative time are included, the difference in cost between miniplates and allograft struts is negligible.

Feasibility of the mini-open vertebral column resection for severe thoracic kyphosis.

Severe thoracic kyphosis caused by pathologic fractures often needs to be corrected by resection of the collapsed vertebral body, reconstruction of the anterior spinal column, and correction of the kyphosis with long-segment fixation. The resection of this pathologic bone functions essentially as a vertebral column resection. With the advent of minimally invasive technology, the powerful corrective forces afforded in open cases can be applied using a less invasive approach. In this article, we describe a mini-open posterior technique for thoracic kyphosis via a vertebrectomy and cantilever technique. Two patients underwent kyphosis correction via mini-open vertebrectomy. One patient was corrected from 92 degrees to 65 degrees, and the second patient was corrected from 70 degrees to 53 degrees. Both patients underwent a mini-open approach. Cantilever correction was accomplished over an expandable cage with a minimally invasive pedicle screw system. We describe our technique of mini-open vertebral column resection and kyphosis correction in the thoracic spine.

The field-dependence of the solid-state photo-CIDNP effect in two states of heliobacterial reaction centers.

The solid-state photo-CIDNP (photochemically induced dynamic nuclear polarization) effect is studied in photosynthetic reaction centers of Heliobacillus mobilis at different magnetic fields by (13)C MAS (magic-angle spinning) NMR spectroscopy. Two active states of heliobacterial reaction centers are probed: an anaerobic preparation of heliochromatophores ("Braunstoff", German for "brown substance") as well as a preparation of cells after exposure to oxygen ("Grünstoff", "green substance"). Braunstoff shows significant increase of enhanced absorptive (positive) signals toward lower magnetic fields, which is interpreted in terms of an enhanced differential relaxation (DR) mechanism. In Grünstoff, the signals remain emissive (negative) at two fields, confirming that the influence of the DR mechanism is comparably low.

N Photo-CIDNP MAS NMR To Reveal Functional Heterogeneity in Electron Donor of Different Plant Organisms.

In plants and cyanobacteria, two light-driven electron pumps, photosystems I and II (PSI, PSII), facilitate electron transfer from water to carbon dioxide with quantum efficiency close to unity. While similar in structure and function, the reaction centers of PSI and PSII operate at widely different potentials with PSI being the strongest reducing agent known in living nature. Photochemically induced dynamic nuclear polarization (photo-CIDNP) in magic-angle spinning (MAS) nuclear magnetic resonance (NMR) measurements provides direct excess to the heart of large photosynthetic complexes (A. Diller, Alia, E. Roy, P. Gast, H.J. van Gorkom, J. Zaanen, H.J.M. de Groot, C. Glaubitz, J. Matysik, Photosynth. Res. 84, 303-308, 2005; Alia, E. Roy, P. Gast, H.J. van Gorkom, H.J.M. de Groot, G. Jeschke, J. Matysik, J. Am. Chem. Soc. 126, 12819-12826, 2004). By combining the dramatic signal increase obtained from the solid-state photo-CIDNP effect with (15)N isotope labeling of PSI, we were able to map the electron spin density in the active cofactors of PSI and study primary charge separation at atomic level. We compare data obtained from two different PSI proteins, one from spinach (Spinacia oleracea) and other from the aquatic plant duckweed (Spirodella oligorrhiza). Results demonstrate a large flexibility of the PSI in terms of its electronic architecture while their electronic ground states are strictly conserved.

The solid-state photo-CIDNP effect.

The solid-state photo-CIDNP effect is the occurrence of a non-Boltzmann nuclear spin polarization in rigid samples upon illumination. For solid-state NMR, which can detect this enhanced nuclear polarization as a strong modification of signal intensity, the effect allows for new classes of experiments. Currently, the photo- and spin-chemical machinery of various RCs is studied by photo-CIDNP MAS NMR in detail. Until now, the effect has only been observed at high magnetic fields with (13)C and (15)N MAS NMR and in natural photosynthetic RC preparations in which blocking of the acceptor leads to cyclic electron transfer. In terms of irreversible thermodynamics, the high-order spin structure of the initial radical pair can be considered as a transient order phenomenon emerging under non-equilibrium conditions and as a first manifestation of order in the photosynthetic process. The solid-state photo- CIDNP effect appears to be an intrinsic property of natural RCs. The conditions of its occurrence seem to be conserved in evolution. The effect may be based on the same fundamental principles as the highly optimized electron transfer. Hence, the effect may allow for guiding artificial photosynthesis.

Characterization of the primary radical pair in reaction centers of Heliobacillus mobilis by 13C photo-CIDNP MAS NMR.

Photochemically induced dynamic nuclear polarization (photo-CIDNP) has been observed in membrane fragments of heliobacterium Heliobacillus mobilis without further isolation by (13)C magic-angle spinning (MAS) solid-state NMR under continuous illumination with white light. In the (13)C photo-CIDNP MAS NMR spectra of heliobacterial membrane fragments, two sets of signals are observed, allowing characterization of the primary radical pair. One set, showing enhanced absorptive (positive) signals, arises from the BChl g donor, while the set of emissive (negative) signals is assigned to the 8(1)-hydroxy Chl a acceptor. Hence, under these sample conditions, both donor and acceptor sides are either monomeric or composed of identical cofactors. The occurrence of the differential relaxation (DR) mechanism suggests a donor triplet lifetime in the microsecond range. It appears that the occurrence of the solid-state photo-CIDNP effect is a general feature of primary radical pairs in natural photosynthesis.

15N photochemically induced dynamic nuclear polarization magic-angle spinning NMR analysis of the electron donor of photosystem II.

In natural photosynthesis, the two photosystems that operate in series to drive electron transport from water to carbon dioxide are quite similar in structure and function, but operate at widely different potentials. In both systems photochemistry begins by photo-oxidation of a chlorophyll a, but that in photosystem II (PS2) has a 0.7 eV higher midpoint potential than that in photosystem I (PS1), so their electronic structures must be very different. Using reaction centers from (15)N-labeled spinach, these electronic structures are compared by their photochemically induced dynamic nuclear polarization (photo-CIDNP) in magic-angle spinning (MAS) NMR measurements. The results show that the electron spin distribution in PS1, apart from its known delocalization over 2 chlorophyll molecules, reveals no marked disturbance, whereas the pattern of electron spin density distribution in PS2 is inverted in the oxidized radical state. A model for the donor of PS2 is presented explaining the inversion of electron spin density based on a tilt of the axial histidine toward pyrrole ring IV causing pi-pi overlap of both aromatic systems.

Photochemically induced dynamic nuclear polarization in the reaction center of the green sulphur bacterium Chlorobium tepidum observed by 13C MAS NMR.

Photochemically induced dynamic nuclear polarization has been observed in reaction centres of the green sulphur bacterium Chlorobium tepidum by (13)C magic-angle spinning solid-state NMR under continuous illumination with white light. An almost complete set of chemical shifts of the aromatic ring carbons of a BChl a molecule has been obtained. All light-induced (13)C NMR signals appear to be emissive, which is similar to the pattern observed in the reaction centers of plant photosystem I and purple bacterial reaction centres of Rhodobacter sphaeroides wild type. The donor in RCs of green sulfur bacteria clearly differs from the substantially asymmetric special pair of purple bacteria and appears to be similar to the more symmetric donor of photosystem I.

Photo-CIDNP solid-state NMR on photosystems I and II:what makes P680 special?

The origin of the extraordinary high redox potential of P680, the primary electron donor of Photosystem II, is still unknown. Photochemically induced dynamic nuclear polarisation (photo-CIDNP) 13C magic-angle spinning (MAS) NMR is a powerful method to study primary electron donors. In order to reveal the electronic structure of P680, we compare new photo-CIDNP MAS NMR data of Photosystem II to those of Photosystem I. The comparison reveals that the electronic structure of the P680 radical cation is a Chl a cofactor with strong matrix interaction, while the radical cation of P700, the primary electron donor of Photosystem I, appears to be a Chl a cofactor which is essentially undisturbed. Possible forms of cofactor-matrix interactions are discussed.

Photochemically induced dynamic nuclear polarization in photosystem I of plants observed by 13C magic-angle spinning NMR.

Photochemically induced dynamic nuclear polarization (photo-CIDNP) has been observed in photosystem I of spinach by (13)C magic angle spinning solid-state NMR under continuous illumination with white light. An almost complete set of chemical shifts of the aromatic ring carbons of a single Chl a molecule has been obtained which is assigned to the P2-cofactor of the primary electron donor P700. Since all light-induced (13)C NMR signals appear to be emissive, a predominance of the three-spin mixing mechanism over the differential decay mechanism is proposed. The origin of the strong contribution of the three-spin mixing mechanism and the differences with photosystem II are discussed.