Electrochemical oxidation of pharmaceuticals in synthetic fresh human urine: Using selective radical quenchers to reveal the dominant degradation pathways and the scavenging effects of individual urine constituents.

Electrochemical oxidation of fresh human urine is a promising method to prevent pharmaceuticals from being discharged into the environment. Here, we evaluate the importance of electro-generated oxidants and direct anodic oxidation for degradation of four pharmaceutical (cyclophosphamide (CP), carbamazepine (CBZ), sulfamethoxazole (SMX) and ibuprofen (IBP)) accounting for the scavenging effect of urine constituents using boron-doped diamond (BDD) and IrO2 electrodes. Allyl alcohol and tert-butanol were used as selective quenchers for adsorbed and dissolved radicals, respectively. In electrolyte containing only chloride and pharmaceuticals, we found that CBZ and SMX are primarily oxidized by electro-generated Cl2 in the fluid boundary layer , and CP and IBP are primarily oxidized by physisorbed •OH or chemisorbed chlorine (IrO3-Cl). Regarding the effects of other fresh urine constituents, urea, creatinine, and uric acid quench the dissolved reactive chlorine species (Cl•/Cl2•‒, HOCl, Cl2, etc.). However, SO42‒ shows no effect on pharmaceutical degradation while H2PO4‒ and citrate ions quench IrO3-Cl resulting in a mixed kinetic and mass-transfer limiting oxidation of pharmaceuticals on IrO2. Citrate ions only quench the dissolved oxidants (surface adsorbed radicals are the dominant oxidants) leading to the pharmaceutical degradation limited by the mass transfer of pharmaceutical to BDD surface. This work provides an understanding of the significance of various pathways for pharmaceutical degradation, scavenging effect of urine constituents, and strategies for rapid pharmaceutical degradation in human urine.

Fracture of dual lumen cannula leading to cerebrovascular accident in a patient supported with ECMO.

Extended duration extracorporeal membrane oxygenation (ECMO), using dual-lumen cannulas, is being used with increased frequency to support patients, including those with COVID-19; both as a bridge to transplant and lung recovery. During such an extended duration of support, there are several factors that might lead to the attrition of the physical structure of the ECMO cannulas, predisposing them to the risk of fracture. Although rare, fracture of the ECMO cannula can be a potentially lethal event. Here, we present a case where fracture of a dual lumen cannula during veno-venous (VV) ECMO support resulted in a cerebrovascular accident. We discuss the potential contributing factors and suggest steps to mitigate the risks for such a complication.

Selective oxidation of pharmaceuticals and suppression of perchlorate formation during electrolysis of fresh human urine.

Urine comprises only a small (~1%) volumetric fraction of municipal wastewater, but represents a dominant source of pharmaceuticals, many of which may pass through conventional wastewater treatment and pose risks to aquatic ecosystems. Point-source treatment of source-separated urine presents a unique opportunity to degrade pharmaceuticals before dilution with wastewater, and electrochemical advanced oxidation processes are one increasingly investigated option. However, they often lead to the formation of oxidation byproducts including chlorate, perchlorate at very high concentrations. Here, we show that the high urea content of fresh human urine suppresses the formation of oxychlorides by inhibiting formation of HOCl/OCl‒ during electrolysis, while still enabling pharmaceutical degradation due to the slow rate of urea oxidation by •OH. This results in improved performance compared to equivalent treatment of hydrolyzed aged urine. This electrochemical oxidation scheme is shown to degrade the model contaminants cyclophosphamide and sulfamethoxazole with surface-area-to-volume-normalized pseudo-first-order rate constants greater than 0.08 cm/min in authentic fresh human urine. It results in ~100 × decrease in pharmaceutical concentrations in 2 h while generating ~1000 × lower oxychloride byproduct concentrations in synthetic fresh urine than synthetic hydrolyzed aged urine matrixes. Importantly, this proof-of-principle shows that simple and safe electrochemical methods can be used for point-source-remediation of pharmaceuticals in fresh human urine (before storage and hydrolysis), without formation of significant oxychloride byproducts.

Equation of State Constraints from the Threshold Binary Mass for Prompt Collapse of Neutron Star Mergers.

Using hydrodynamical simulations for a large set of high-density matter equations of state (EOSs), we systematically determine the threshold mass M_{thres} for prompt black-hole formation in equal-mass and asymmetric neutron star (NS) mergers. We devise the so far most direct, general, and accurate method to determine the unknown maximum mass of nonrotating NSs from merger observations revealing M_{thres}. Considering hybrid EOSs with hadron-quark phase transition, we identify a new, observable signature of quark matter in NS mergers. Furthermore, our findings have direct applications in gravitational wave searches, kilonova interpretations, and multimessenger constraints on NS properties.

Measuring Spin of the Remnant Black Hole from Maximum Amplitude.

Gravitational waves emitted during the merger of two black holes carry information about the remnant black hole, namely its mass and spin. This information is typically found from the ringdown radiation as the black hole settles to a final state. We find that the remnant black hole spin is already known at the peak amplitude of the gravitational wave strain. Using this knowledge, we present a new method for measuring the final spin that is template independent, using only the chirp mass, the instantaneous frequency of the strain, and its derivative at maximum amplitude, all template independent.

Identifying a First-Order Phase Transition in Neutron-Star Mergers through Gravitational Waves.

We identify an observable imprint of a first-order hadron-quark phase transition at supranuclear densities on the gravitational-wave (GW) emission of neutron-star mergers. Specifically, we show that the dominant postmerger GW frequency f_{peak} may exhibit a significant deviation from an empirical relation between f_{peak} and the tidal deformability if a strong first-order phase transition leads to the formation of a gravitationally stable extended quark matter core in the postmerger remnant. A comparison of the GW signatures from a large, representative sample of microphysical, purely hadronic equations of state indicates that this imprint is only observed in those systems which undergo a strong first-order phase transition. Such a shift of the dominant postmerger GW frequency can be revealed by future GW observations, which would provide evidence for the existence of a strong first-order phase transition in the interior of neutron-stars.

Complexation Chemistry in N,N-Dimethylformamide-Based Molecular Inks for Chalcogenide Semiconductors and Photovoltaic Devices.

Molecular inks based on dimethyl sulfoxide, thiourea (TU), and metal salts have been used to form high optoelectronic quality semiconductors and have led to high power conversion efficiencies for solution-processed photovoltaic devices for Cu2ZnSn(S,Se)4 (CZTS), Cu2Zn(Ge,Sn)(S,Se)4 (CZGTS), CuIn(S,Se)2 (CIS), and Cu(In,Ga)(S,Se)2 (CIGS). However, several metal species of interest, including Ag(I), In(III), Ge(II), and Ge(IV), either have low solubility (requiring dilute inks) or lead to precipitation or gelation. Here, we demonstrate that the combination of N,N-dimethylformamide (DMF) and TU has the remarkable ability to form intermediate-stability acid-base complexes with a wide number of metal chloride Lewis acids (CuCl, AgCl, ZnCl2, InCl3, GaCl3, SnCl4, GeCl4, and SeCl4), to give high-concentration stable molecular inks. Using calorimetry, Raman spectroscopy, and solubility experiments, we reveal the important role of chloride transfer and TU to stabilize metal cations in DMF. Methylation of TU is used to vary the strength of the Lewis basicity and demonstrate that the strength of the TU-metal chloride complex formed after DMF evaporation is critical to prevent volatilization of metal containing species. Further, we formulated a sulfur-free molecular ink which was used to deposit crystalline CuInSe2 without selenization that sustains high quasi-Fermi level splitting under constant illumination. Finally, we demonstrate the ability of the DMF-TU molecular ink chemistry to lead to high-photovoltaic power conversion efficiencies and high-open-circuit voltages for solution-processed CIS and CZGTS with power conversion efficiencies of 13.4% and 11.0% and Voc/ Voc,SQ of 67% and 63%, respectively.

Tracking Black Hole Kicks from Gravitational-Wave Observations.

Coalescing binary black holes emit anisotropic gravitational radiation. This causes a net emission of linear momentum that produces a gradual acceleration of the source. As a result, the final remnant black hole acquires a characteristic velocity known as recoil velocity or gravitational kick. The symmetries of gravitational wave emission are reflected in the interactions of the gravitational wave modes emitted by the binary. In this Letter, we make use of the rich information encoded in the higher-order modes of the gravitational wave emission to infer the component of the kick along the line of sight (or radial kick). We do this by performing parameter inference on simulated signals given by numerical relativity waveforms for nonspinning binaries using numerical relativity templates of aligned-spin (nonprecessing) binary black holes. We find that for suitable sources, namely those with mass ratio q≥2 and total mass M∼100 M_{⊙}, and for modest radial kicks of 120 km/s, the 90% credible intervals of our posterior probability distributions can exclude a zero kick at a signal-to-noise ratio of 15, using a single Advanced LIGO detector working at its early sensitivity. The measurement of a nonzero radial kick component would provide the first observational signature of net transport of linear momentum by gravitational waves away from their source.

Cardiac physiologic and genetic predictors of hyperoxia-induced acute lung injury in mice.

Exposure of mice to hyperoxia produces pulmonary toxicity similar to acute lung injury/acute respiratory distress syndrome, but little is known about the interactions within the cardiopulmonary system. This study was designed to characterize the cardiopulmonary response to hyperoxia, and to identify candidate susceptibility genes in mice. Electrocardiogram and ventilatory data were recorded continuously from 4 inbred and 29 recombinant inbred strains during 96 hours of hyperoxia (100% oxygen). Genome-wide linkage analysis was performed in 27 recombinant inbred strains against response time indices (TIs) calculated from each cardiac phenotype. Reductions in minute ventilation, heart rate (HR), low-frequency (LF) HR variability (HRV), high-frequency HRV, and total power HRV were found in all mice during hyperoxia exposure, but the lag time before these changes began was strain dependent. Significant (chromosome 9) or suggestive (chromosomes 3 and 5) quantitative trait loci were identified for the HRTI and LFTI. Functional polymorphisms in several candidate susceptibility genes were identified within the quantitative trait loci and were associated with hyperoxia susceptibility. This is the first study to report highly significant interstrain variation in hyperoxia-induced changes in minute ventilation, HR, and HRV, and to identify polymorphisms in candidate susceptibility genes that associate with cardiac responses. Results indicate that changes in HR and LF HRV could be important predictors of subsequent adverse outcome during hyperoxia exposure, specifically the pathogenesis of acute lung injury. Understanding the genetic mechanisms of these responses may have significant diagnostic clinical value.

Effects of buprenorphine, meloxicam, and flunixin meglumine as postoperative analgesia in mice.

C57BL/6NCrl male mice (n = 60; age, 6 to 7 wk) underwent partial hepatectomy or no surgery and were given 1 of 3 analgesics pre- and postoperatively. Food and water consumption, body weight, running wheel activity, locomotor activity, and serum corticosterone concentrations were measured before and after surgery. Mice that were surgically manipulated weighed significantly less on days 1 through 3 after surgery than did mice not manipulated surgically. On the day of surgery, the surgery groups consumed significantly less feed (-1.5±0.35 g) than did nonsurgery groups. There were no differences in water consumption on any day between surgery and nonsurgery groups or among the 3 analgesic groups. For running wheel activity, significant decreases in the surgery groups were seen at day 1 after surgery compared with baseline. Surgery groups that received buprenorphine and meloxicam returned to baseline activity levels on day 2 after surgery. Open-field testing revealed no significant differences in locomotor activity in any groups; however, posttreatment locomotor activity in the buprenorphine nonsurgery group was increased compared with baseline, and posttreatment locomotor activity in the flunixin meglumine surgery group was decreased compared with baseline. Serum corticosterone concentrations were within normal limits regardless of treatment in all groups. Comparison of the overall results indicated that meloxicam and buprenorphine, at the dose given, appear to be suitable postoperative analgesics for partial hepatectomy in mice. Flunixin meglumine at the given dosage (2.5 mg/kg) may not provide adequate analgesia for partial hepatectomy.

Impact of ABCB1 allelic variants on QTc interval prolongation.

PURPOSE: Although the ABCB1 (P-glycoprotein) drug transporter is a constituent of several blood-tissue barriers (i.e., blood-brain and blood-nerve), its participation in a putative blood-heart barrier has been poorly explored. ABCB1 could decrease the intracardiac concentrations of drugs that cause QT prolongation and cardiotoxicity. EXPERIMENTAL DESIGN: ABCB1-related romidepsin transport kinetics were explored in LLC-PK1 cells transfected with different ABCB1 genetic variants. ABCB1 plasma and intracardiac concentrations were determined in Abcb1a/1b (-/-) mice and wild-type FVB controls. These same mice were used to evaluate romidepsin-induced heart rate-corrected QT interval (QTc) prolongation over time. Finally, a cohort of 83 individuals with available QTcB and ABCB1 genotyping data were used to compare allelic variation in ABCB1 versus QTc-prolongation phenotype. RESULTS: Here, we show that mice lacking the ABCB1-type P-glycoprotein have higher intracardiac concentrations of a model ABCB1 substrate, romidepsin, that correspond to changes in QT prolongation from baseline (ΔQTc) over time. Consistent with this observation, we also show that patients carrying genetic variants that could raise ABCB1 expression in the cardiac endothelium have lower ΔQTc following a single dose of romidepsin. CONCLUSIONS: To our knowledge, this is the first evidence that Abcb1-type P-glycoprotein can limit intracardiac exposure to a drug that mediates QT prolongation and suggests that certain commonly inherited polymorphisms in ABCB1 may serve as markers for QT prolongation following the administration of ABCB1-substrate drugs.

Defective generation of a humoral immune response is associated with a reduced incidence and severity of collagen-induced arthritis in microsomal prostaglandin E synthase-1 null mice.

Microsomal PGE synthase-1 (mPGES-1) is an inducible enzyme that acts downstream of cyclooxygenase and specifically catalyzes the conversion of PGH(2) to PGE(2). The present study demonstrates the effect of genetic deletion of mPGES-1 on the developing immunologic responses and its impact on the clinical model of bovine collagen-induced arthritis. mPGES-1 null and heterozygous mice exhibited decreased incidence and severity of arthritis compared with wild-type mice in a gene dose-dependent manner. Histopathological examination revealed significant reduction in lining hyperplasia and tissue destruction in mPGES-1 null mice compared with their wild-type littermates. mPGES-1 deficient mice also exhibited attenuation of mechanical nociception in a gene dose-dependent manner. In addition, mPGES-1 null and heterozygous mice showed a marked reduction of serum IgG against type II collagen, including subclasses IgG1, IgG2a, IgG2b, IgG2c, and IgG3, compared with wild-type mice, which correlated with the reduction in observed inflammatory features. These results demonstrate for the first time that deficiency of mPGES-1 inhibits the development of collagen-induced arthritis, at least in part, by blocking the development of a humoral immune response against type II collagen. Pharmacologic inhibition of mPGES-1 may therefore impact both the inflammation and the autoimmunity associated with human diseases such as rheumatoid arthritis.

The genetic contribution to heart rate and heart rate variability in quiescent mice.

Recent studies have suggested a genetic component to heart rate (HR) and HR variability (HRV). However, a systematic examination of the genetic contribution to the variation in HR and HRV has not been performed. This study investigated the genetic contribution to HR and HRV using a wide range of inbred and recombinant inbred (RI) mouse strains. Electrocardiogram data were recorded from 30 strains of inbred mice and 29 RI strains. Significant differences in mean HR and total power (TP) HRV were identified between inbred strains and RI strains. Multiple significant differences within the strain sets in mean low-frequency (LF) and high-frequency (HF) power were also found. No statistically significant concordance was found between strain distribution patterns for HR and HRV phenotypes. Genomewide interval mapping identified a significant quantitative trait locus (QTL) for HR [LOD (likelihood of the odds) score = 3.763] on chromosome 6 [peak at 53.69 megabases (Mb); designated HR 1 (Hr1)]. Suggestive QTLs for TP were found on chromosomes 2, 4, 5, 6, and 14. A suggestive QTL for LF was found on chromosome 16; for HF, we found one significant QTL on chromosome 5 (LOD score = 3.107) [peak at 53.56 Mb; designated HRV-high-frequency 1 (Hrvhf1)] and three suggestive QTLs on chromosomes 2, 11 and 15. In conclusion, the results demonstrate a strong genetic component in the regulation of resting HR and HRV evidenced by the significant differences between strains. A lack of correlation between HR and HRV phenotypes in some inbred strains suggests that different sets of genes control the phenotypes. Furthermore, QTLs were found that will provide important insight to the genetic regulation of HR and HRV at rest.

Identification of Xenopus heat shock transcription factor-2: conserved role of sumoylation in regulating deoxyribonucleic acid-binding activity of heat shock transcription factor-2 proteins.

Heat shock transcription factor (Hsf)-1 and Hsf2 are members of the heat shock factor (HSF) protein family involved in heat shock protein (hsp) gene regulation, a regulation that is critical for the ability of cells to survive exposure to stress conditions. Although the role of Hsf1 in binding and activating transcription of hsp gene promoters in response to cell stress is well established, how Hsf2 enhances stress-induced hsp expression is not understood. To gain an insight into the critical conserved features of the regulation and function of Hsf2, we have identified and characterized the Hsf2 protein from Xenopus laevis. We found that, similar to its human counterpart, Xenopus Hsf2 is sumoylated at lysine 82 and that, as it does in human Hsf2, the modification event of the small ubiquitin-related modifier 1 functions to increase the deoxyribonucleic acid-binding activity of this transcription factor in Xenopus. These results indicate that sumoylation is an evolutionarily conserved modification of Hsf2 proteins, supporting the position of this modification as a critical regulator of Hsf2 function.

Gill trematodes (flukes) in wild-caught killifish (Fundulus heteroclitus).

Three wild caught killifish (Fundulus heteroclitus) on an Institutional Animal Care and Use Committee-approved protocol were found dead within 2 days after being received. The fish were housed in two separate aquaria. Aquarium water was evaluated, and pH, salinity, ammonia, nitrate, and nitrite levels were within acceptable parameters. Several remaining fish appeared to be slow-moving and were presented for necropsy. Multiple, scattered, ulcerated skin lesions (diameter, 1 to 5 mm) were noted at necropsy and were cultured. No pathogenic bacteria were isolated. Wet-mount samples of the gills revealed multiple cysts at the gill margins, each containing a motile organism. No other gill parasites were detected. A diagnosis of trematodiasis was made. The cysts were identified as encysted metacercariae of a digenetic trematode. We surmise that the large numbers of gill flukes combined with the stress of recent shipment likely caused the observed morbidity and mortality.

Mammary gland development in adult mice requires epithelial and stromal estrogen receptor alpha.

Complete mammary gland development takes place following puberty and depends on the estrogen receptor (ER)alpha and the progesterone receptor (PR) and is tightly regulated by the interaction of the mammary epithelium with the stromal compartment. Studies using mammary tissues of immature mice have indicated that stromal but not epithelial ER alpha is required for mammary gland growth. This study investigates whether these same tissue growth requirements of neonate tissue are necessary for mammary development and response in adult mice. Mammary epithelial cells were isolated from adult mice with a targeted disruption of the ER alpha gene (alpha ERKO) or from wild-type counterparts and injected into epithelial-free mammary fat pads of 3-wk-old female alpha ERKO or wild-type mice. Ten weeks after cell injection, analysis of mammary gland whole mounts showed that both stromal and epithelial ER alpha were required for complete mammary gland development in adult mice. However, when the mice were treated with high doses of estradiol (E2) and progesterone, stromal ER alpha was sufficient to generate full mammary gland growth. Surprisingly, ER alpha-deficient epithelial cells were able to proliferate and develop into a rudimentary mammary ductal structure in an ER alpha-negative stroma, indicating that neither stromal nor epithelial ER alpha are required for the mammary rudiment to form in the adult mouse, as confirmed by the phenotype of the alpha ERKO mammary gland. Use of this in vivo model system has demonstrated that neonatal and adult mammary tissues use a different tissue-specific role for ER alpha in mammary response. Immunostaining for ER alpha and PR in the mammary outgrowths supported the view that both stromal and epithelial ER alpha, in cooperation with epithelial PR, govern mammary gland development in adult mice.