Ag(III)···Ag(III) Argentophilic Interaction in a Cofacial Corrole Dyad.

Metallophilic interactions between closed-shell metal centers are exemplified by d10 ions, with Au(I) aurophilic interactions as the archetype. Such an interaction extends to d8 species, and examples involving Au(III) are prevalent. Conversely, Ag(III) argentophilic interactions are uncommon. Here, we identify argentophilic interactions in silver corroles, which are authentic Ag(III) species. The crystal structure of a monomeric silver corrole is a dimer in the solid state, and the macrocycle exhibits an atypical domed conformation. In order to evaluate whether this represents an authentic metallophilic interaction or a crystal-packing artifact, the analogous cofacial or "pacman" corrole was prepared. The conformation of the monomer was recapitulated in the silver pacman corrole, exhibiting a short 3.67 Å distance between metal centers and a significant compression of the xanthene backbone. Theoretical calculations support the presence of a rare Ag(III)···Ag(III) argentophilic interaction in the pacman complex.

Psychiatric Emergencies in Los Angeles County During, and After, Initial COVID-19 Societal Restrictions: An Interrupted Time-Series Analysis.

Emergency department (ED) visits for psychiatric care in the US reportedly declined during the COVID-19 pandemic. This work, however, does not control for strong temporal patterning in visits before the pandemic and does not examine a potential "rebound" in demand for psychiatric care following the relaxation of initial societal restrictions. Here, we examine COVID-19-related perturbations in psychiatric care during and after the 1st stage of societal restrictions in the largest safety-net hospital in Los Angeles. We retrieved psychiatric ED visit data (98,888 total over 156 weeks, Jan 2018 to Dec 2020) from Los Angeles County + USC Medical Center. We applied interrupted time series methods to identify and control for autocorrelation in psychiatric ED visits before examining their relation with the 1st stage of societal restrictions (i.e., March 13 to May 8, 2020), as well as the subsequent "rebound" period of relaxed restrictions (i.e., after May 8, 2020). Psychiatric ED visits fell by 78.13 per week (i.e., 12%) during the 1st stage of societal restrictions (SD = 23.99, p < 0.01). Reductions in ED visits for alcohol use, substance use, and (to a lesser extent) anxiety disorders accounted for the overall decline. After the 1st stage of societal restrictions, however, we observe no "rebound" above expected values in psychiatric ED visits overall (coef = - 16.89, SD = 20.58, p = 0.41) or by diagnostic subtype. This pattern of results does not support speculation that, at the population level, foregoing ED care during initial societal restrictions subsequently induced a psychiatric "pandemic" of urgent visits.

Solvent-Induced Spin-State Change in Copper Corroles.

The electronic structure of copper corroles has been a topic of debate and revision since the advent of corrole chemistry. The ground state of these compounds is best described as an antiferromagnetically coupled Cu(II) corrole radical cation. In coordinating solvents, these molecules become paramagnetic, and this is often accompanied by a color change. The underlying chemistry of these solvent-induced properties is currently unknown. Here, we show that a coordinating solvent, such as pyridine, induces a change in the ground spin state from an antiferromagnetically coupled Cu(II) corrole radical cation to a ferromagnetically coupled triplet. Over time, the triplet reacts to produce a species with spectral signatures that are characteristic of the one-electron-reduced Cu(II) corrole. These observations account for the solvent-induced paramagnetism and the associated color changes that have been observed for copper corroles in coordinating solvents.

COVID-19 case counts and COVID-19 related Emergency Department visits: differences by immigration status, March-December 2020.

BACKGROUND: Undocumented immigrants face barriers to health care access, which may have been exacerbated during the early days of the COVID-19 pandemic. We test whether undocumented immigrants in Los Angeles County accessed COVID-19 related medical care by examining their Emergency Department (ED) patterns through high and low periods of COVID-19 infection. If undocumented immigrants were underutilizing or foregoing health care, we expect null or weaker associations between COVID-19 cases and COVID-19 related ED visits relative to Medi-Cal patients. METHODS: We analyzed all ED visits to the Los Angeles County + University of Southern California (LAC + USC) Medical Center between March - December 2020 (n = 85,387). We conducted logistic regressions with Los Angeles County weekly COVID-19 case counts as our main independent variable and an interaction between case counts and immigration status, stratified by age (over and under 65 years). RESULTS: We found that undocumented immigrants under 65 years old had a higher odds for a COVID-19 related ED visit compared to Medi-Cal patients and that both undocumented and Medi-Cal patients had higher odds of a COVID-19 related ED visit as COVID-19 cases in Los Angeles County increased. For patients over 65 years, Medi-Cal patients actually had a weaker association between ED visits and county COVID-19 counts; as COVID-19 case counts rose, the odds of a COVID-19 related ED visit increased for the undocumented patients. CONCLUSION: While the overall likelihood of undocumented patients having a COVID-19 related ED visit varies compared to Medi-Cal patients - for younger patients, the odds is higher; for older patients, the odds is lower - it does not appear that undocumented patients underutilized the ED during the early COVID-19 pandemic relative to Medi-Cal patients. The ED may be a viable source of contact for this high-risk population for future outreach.

Standardized Workflows Improve Colonoscopy Follow-Up After Abnormal Fecal Immunochemical Tests in a Safety-Net System.

BACKGROUND: How clinical teams function varies across sites and may affect follow-up of abnormal fecal immunochemical test (FIT) results. AIMS: This study aimed to identify the characteristics of clinical practices associated with higher diagnostic colonoscopy completion after an abnormal FIT result in a multi-site integrated safety-net system. METHODS: We distributed survey questionnaires about tracking and follow-up of abnormal FIT results to primary care team members across 11 safety-net clinics from January 2017 to April 2017. Surveys were distributed at all-staff clinic meetings and electronic surveys sent to those not in attendance. Participants received up to three reminders to complete the survey. RESULTS: Of the 501 primary care team members identified, 343 (68.5%) completed the survey. In the four highest-performing clinics, nurse managers identified at least two team members who were responsible for communicating abnormal FIT results to patients. Additionally, team members used a clinic-based registry to track patients with abnormal FIT results until colonoscopy completion. Compared to higher-performing clinics, lower-performing clinics more frequently cited competing health issues (56% vs. 40%, p = 0.03) and lack of patient priority (59% vs. 37%, p < 0.01) as barriers and were also more likely to discuss abnormal results at a clinic visit (83% vs. 61%, p < 0.01). CONCLUSIONS: Our findings suggest organized and dedicated efforts to communicate abnormal FIT results and track patients until colonoscopy completion through registries is associated with improved follow-up. Increased utilization of electronic health record platforms to coordinate communication and navigation may improve diagnostic colonoscopy rates in patients with abnormal FIT results.

Promoting P450 BM3 heme domain dimerization with a tris(5-iodoacetamido-1,10-phenanthroline)Ru(II) complex.

Protein dimerization often occurs in many biological systems as to provide structural and functional advantages. A tris(5-iodoacetamido-1,10-phenanthroline)Ruthenium(II) complex was shown to promote the covalent dimerization of a P450 BM3 heme domain mutant containing a surface exposed non-native single cysteine residue. The formation of homodimeric species was confirmed by protein gel electrophoresis, mass spectrometry and UV-Vis spectroscopy. The dimeric species could be separated from the monomer and aggregates by size-exclusion chromatography. Docking simulation reveals a plausible structure with two proteins covalently conjugated to the inorganic compound.

Properties of Site-Specifically Incorporated 3-Aminotyrosine in Proteins To Study Redox-Active Tyrosines: Escherichia coli Ribonucleotide Reductase as a Paradigm.

3-Aminotyrosine (NH2Y) has been a useful probe to study the role of redox active tyrosines in enzymes. This report describes properties of NH2Y of key importance for its application in mechanistic studies. By combining the tRNA/NH2Y-RS suppression technology with a model protein tailored for amino acid redox studies (α3X, X = NH2Y), the formal reduction potential of NH2Y32(O•/OH) ( E°' = 395 ± 7 mV at pH 7.08 ± 0.05) could be determined using protein film voltammetry. We find that the Δ E°' between NH2Y32(O•/OH) and Y32(O•/OH) when measured under reversible conditions is ∼300-400 mV larger than earlier estimates based on irreversible voltammograms obtained on aqueous NH2Y and Y. We have also generated D6-NH2Y731-α2 of ribonucleotide reductase (RNR), which when incubated with ß2/CDP/ATP generates the D6-NH2Y731•-α2/ß2 complex. By multifrequency electron paramagnetic resonance (35, 94, and 263 GHz) and 34 GHz 1H ENDOR spectroscopies, we determined the hyperfine coupling (hfc) constants of the amino protons that establish RNH2• planarity and thus minimal perturbation of the reduction potential by the protein environment. The amount of Y in the isolated NH2Y-RNR incorporated by infidelity of the tRNA/NH2Y-RS pair was determined by a generally useful LC-MS method. This information is essential to the utility of this NH2Y probe to study any protein of interest and is employed to address our previously reported activity associated with NH2Y-substituted RNRs.

Posterior Reversible Encephalopathy Syndrome (PRES) Presenting as Status Epilepticus: A Case Report and Literature Review.

Posterior reversible encephalopathy syndrome (PRES) is one of many causes of status epilepticus (SE). Itis defined classically as a clinical radiographic entity, characterized by presentation of headache, altered mental status, visual disturbances, seizures, and typical neuroradiographic findings of symmetrical white-matter edema. Predisposing conditions include uncontrolled hypertension, eclampsia, and use of chemotherapeu- tic and immunosuppressant agents. Bevacizumab (Avastin), a monoclonal antibody against vascular endothelial growth factor (VEGF), is used in a combination with FOLFOX [FOL - Folinic acid; F - Fluorouracil (5-FU); OX - Oxaliplatin] as a first-line treatment for patients with metastatic colorectal cancer. We present a case of a 52-year-old male on systemic chemotherapy with FOLFOX and bevacizumab who presented with SE and was diagnosed with PRES. His symptoms resolved with intensive control of blood pressure and discontinuation of chemotherapy. Bevacizumab-induced vasospasm, endothelial and blood-brain-barrier dysfunction, in combination with elevated blood pressure, were likely the underlying mechanism of PRES in our patient.

Electronic Structure of Copper Corroles.

The ground state electronic structure of copper corroles has been a topic of debate and revision since the advent of corrole chemistry. Computational studies formulate neutral Cu corroles with an antiferromagnetically coupled Cu(II) corrole radical cation ground state. X-ray photoelectron spectroscopy, EPR, and magnetometry support this assignment. For comparison, Cu(II) isocorrole and [TBA][Cu(CF3)4] were studied as authentic Cu(II) and Cu(III) samples, respectively. In addition, the one-electron reduction and one-electron oxidation processes are both ligand-based, demonstrating that the Cu(II) centre is retained in these derivatives. These observations underscore ligand non-innocence in copper corrole complexes.

Nature of Activated Manganese Oxide for Oxygen Evolution.

Electrodeposited manganese oxide films (MnOx) are promising stable oxygen evolution catalysts. They are able to catalyze the oxygen evolution reaction in acidic solutions but with only modest activity when prepared by constant anodic potential deposition. We now show that the performance of these catalysts is improved when they are "activated" by potential cycling protocols, as measured by Tafel analysis (where lower slope is better): upon activation the Tafel slope decreases from ∼120 to ∼70 mV/decade in neutral conditions and from ∼650 to ∼90 mV/decade in acidic solutions. Electrochemical, spectroscopic, and structural methods were employed to study the activation process and support a mechanism where the original birnessite-like MnOx (δ-MnO2) undergoes a phase change, induced by comproportionation with cathodically generated Mn(OH)2, to a hausmannite-like intermediate (α-Mn3O4). Subsequent anodic conditioning from voltage cycling or water oxidation produces a disordered birnessite-like phase, which is highly active for oxygen evolution. At pH 2.5, the current density of activated MnOx (at an overpotential of 600 mV) is 2 orders of magnitude higher than that of the original MnOx and begins to approach that of Ru and Ir oxides in acid.

Modulation of Phenol Oxidation in Cofacial Dyads.

The presentation of two phenols on a xanthene backbone is akin to the tyrosine dyad (Y730 and Y731) of ribonucleotide reductase. X-ray crystallography reveals that the two phenol moieties are cofacially disposed at 4.35 Å. Cyclic voltammetry reveals that phenol oxidation is modulated within the dyad, which exhibits a splitting of one-electron waves with the second oxidation of the phenol dyad occurring at larger positive potential than that of a typical phenol. In contrast, a single phenol appended to a xanthene exhibits a two-electron process, consistent with reported oxidation pathways of phenols in acetonitrile. The perturbation of the phenol potential by stacking is reminiscent of a similar effect for guanines stacked within DNA base pairs.

Photophysical properties of ß-substituted free-base corroles.

Corroles are an emergent class of fluorophores that are finding an application and reaction chemistry to rival their porphyrin analogues. Despite a growing interest in the synthesis, reactivity, and functionalization of these macrocycles, their excited-state chemistry remains undeveloped. A systematic study of the photophysical properties of ß-substituted corroles was performed on a series of free-base ß-brominated derivatives as well as a ß-linked corrole dimer. The singlet and triplet electronic states of these compounds were examined with steady-state and time-resolved spectroscopic methods, which are complemented with density functional theory (DFT) and time-dependent DFT calculations to gain insight into the nature of the electronic structure. Selective bromination of a single molecular edge manifests in a splitting of the Soret band into x and y polarizations, which is a consequence of asymmetry of the molecular axes. A pronounced heavy atom effect is the primary determinant of the photophysical properties of these free-base corroles; bromination decreases the fluorescence quantum yield (from 15% to 0.47%) and lifetime (from 4 ns to 80 ps) by promoting enhanced intersystem crossing, as evidenced by a dramatic increase in knr with bromine substitution. The nonbrominated dimer exhibits absorption and emission features comparable to those of the tetrabrominated derivative, suggesting that oligomerization provides a means of red-shifting the spectral properties akin to bromination but without decreasing the fluorescence quantum yield.

A functionally stable manganese oxide oxygen evolution catalyst in acid.

First-row metals have been a target for the development of oxygen evolution reaction (OER) catalysts because they comprise noncritical elements. We now report a comprehensive electrochemical characterization of manganese oxide (MnOx) over a wide pH range, and establish MnOx as a functionally stable OER catalyst owing to self-healing, is derived from MnOx redeposition that offsets catalyst dissolution during turnover. To study this process in detail, the oxygen evolution mechanism of MnOx was investigated electrokinetically over a pH range spanning acidic, neutral, and alkaline conditions. In the alkaline pH regime, a ∼60 mV/decade Tafel slope and inverse first-order dependence on proton concentration were observed, whereas the OER acidic pH regime exhibited a quasi-infinite Tafel slope and zeroth-order dependence on proton concentration. The results reflect two competing mechanisms: a one-electron one-proton PCET pathway that is dominant under alkaline conditions and a Mn(3+) disproportionation process, which predominates under acidic conditions. Reconciling the rate laws of these two OER pathways with that of MnOx electrodeposition elucidates the self-healing characteristics of these catalyst films. The intersection of the kinetic profile of deposition and that of water oxidation as a function of pH defines the region of kinetic stability for MnOx and importantly establishes that a non-noble metal oxide OER catalyst may be operated in acid by exploiting a self-healing process.

Water oxidation catalysis by Co(II) impurities in Co(III)4O4 cubanes.

The observed water oxidation activity of the compound class Co4O4(OAc)4(Py-X)4 emanates from a Co(II) impurity. This impurity is oxidized to produce the well-known Co-OEC heterogeneous cobaltate catalyst, which is an active water oxidation catalyst. We present results from electron paramagnetic resonance spectroscopy, nuclear magnetic resonance line broadening analysis, and electrochemical titrations to establish the existence of the Co(II) impurity as the major source of water oxidation activity that has been reported for Co4O4 molecular cubanes. Differential electrochemical mass spectrometry is used to characterize the fate of glassy carbon at water oxidizing potentials and demonstrate that such electrode materials should be used with caution for the study of water oxidation catalysis.

Discrimination and psychological distress among Asian Americans during COVID-19: Gender differences in the moderating role of social support.

Our study aimed to assess the role of social support on the impact of discrimination on psychological distress for Asian American women and men. Using the Asian American sample from the Asian American and Native Hawaiian/Pacific Islander COVID-19 Needs Assessment Study (n = 3,508), we used logistic regression to examine the moderating role of different types of social support on the relationship between discrimination and psychological distress by gender. Among Asian Americans, facing discrimination was associated with higher odds of psychological distress, and receiving emotional support was associated with lower odds of psychological distress. When examining interactions between discrimination, social support, and gender, we found that facing discrimination led to the highest odds of psychological distress for Asian American women who provided emotional support. Our findings highlight different mechanisms by which social support buffers and exacerbates the psychological burden of discrimination for Asian Americans. These findings have overall and gender-informed implications for community policies to promote mental health resilience by actively alleviating the effects of racism among Asian Americans. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Mental Health Needs Among Asian and Asian American Adults During the COVID-19 Pandemic.

OBJECTIVE: Disaggregated data on the mental health of Asian/Asian American people are needed to inform public health interventions related to reports of racism during the COVID-19 pandemic. We describe the prevalence of psychological distress and unmet mental health needs among Asian/Asian American adults during the COVID-19 pandemic across various sociodemographic subgroups. METHODS: We used cross-sectional, weighted data from the US-based 2021 Asian American and Native Hawaiian/Pacific Islander COVID-19 Needs Assessment Study (unweighted n = 3508) to estimate prevalence rates of psychological distress and unmet mental health needs, overall and by nativity status. We conducted population-weighted multivariable logistic regression analyses to examine sociodemographic factors associated with these mental health outcomes. RESULTS: About one-third (1419 of 3508) of Asian/Asian American adults (32.9%; 95% CI, 30.6%-35.2%) reported psychological distress; odds of psychological distress were increased among adults who were female, trans, and nonbinary; aged 18-44 years; US-born; Cambodian; multiracial; and low income. Of those reporting psychological distress (638 of 1419), 41.8% (95% CI, 37.8%-45.8%) reported unmet mental health needs; unmet mental health needs were highest among Asian/Asian American adults who were aged 18-24 years; Korean, Japanese, and Cambodian; US-born female; non-US-born young adults; and non-US-born with ≥bachelor's degree. CONCLUSIONS: The mental health of Asian/Asian American people is an important public health concern, with some groups more vulnerable and in need of services than others. Mental health resources need to be designed for vulnerable subgroups, and cultural and systemic barriers to mental health care need to be addressed.

Emergency Department Utilization Among Undocumented Latino Patients During the COVID-19 Pandemic.

OBJECTIVE: To determine whether Latino undocumented immigrants had a steeper decline in Emergency Department (ED) utilization compared to Latino Medi-Cal patients in a Los Angeles safety-net hospital, March 13, 2020, to May 8, 2020. STUDY DESIGN: The data were extracted from patient medical records for ED visits at LAC + USC Medical Center from January 2018 to September 2020. We analyzed weekly ED encounters among undocumented Latino patients in the nine-week period after COVID was declared a national emergency. We applied time-series routines to identify and remove autocorrelation in ED encounters before examining its relation with the COVID-19 pandemic. We included Latino patients 18 years of age and older who were either on restricted or full-scope Medi-Cal (n = 230,195). RESULTS: All low-income Latino patients, regardless of immigration status, experienced a significant decline in ED utilization during the first nine weeks of the pandemic. Undocumented patients, however, experienced an even steeper decline. ED visits for this group fall below expected levels between March 13, 2020, and May 8, 2020 (coef. = - 38.67; 95% CI = - 71.71, - 5.63). When applied to the weekly mean of ED visits, this translates to a 10% reduction below expected levels in ED visits during this time period. CONCLUSION: Undocumented immigrants' health care utilization was influenced by external events that occurred early in the pandemic, such as strict stay-at-home orders and the public charge rule change. Health care institutions and local policy efforts could work to ensure that hospitals are safer spaces for undocumented immigrants to receive care without immigration concerns.

COVID-19-Related Emergency Department Visits Among Undocumented Patients in Los Angeles County.

Undocumented immigrants may be vulnerable to poor COVID-19 outcomes, but also may be less likely to seek medical care. To our knowledge, there have not been any investigations of potential COVID-19 disparities by immigration status. We analyzed emergency department (ED) visit data from March 20, 2020 to September 30, 2020 among patients in a safety-net hospital in Los Angeles County (n=30,023). We compared the probability of COVID-19-related ED visits between undocumented immigrants and Medi-Cal patients. We also examined differences in these comparisons over time. Undocumented patients had higher odds of COVID-19-related ED visits than Medi-Cal patients (OR: 1.41, 95% CI: 1.24-1.60) for all months in the study period except September. Even in the earliest days of the pandemic, undocumented patients were more likely than Medi-Cal patients to have a COVID-19-related ED visit. Additional analyses suggest this was likely because of higher COVID-19 exposure rather than differences in ED utilization.

Psychiatric Admissions Among Undocumented Immigrants at an Urban County Hospital.

Little is known about the inpatient mental health needs of undocumented immigrants in the United States. Based on existing literature, we hypothesized that undocumented patients would have fewer psychiatric admissions than documented patients. We reviewed 2019 inpatient admission data for Hispanic/Latino patients at an urban hospital. Patients were coded as undocumented or documented using insurance proxies. Multivariable logistic regression was used to report odds ratio of admission diagnoses of interest by documentation status. There were no significant differences in psychiatric admissions between undocumented patients (2.1%) and documented patients (2.8%) (p=.77). Compared with documented counterparts, undocumented patients were more likely to be admitted for alcohol-related disorders (AOR=1.59, 95%CI=1.31-1.93) but had lower proportions of admission for substance-related disorders, mood disorders, anxiety disorders, and suicide and intentional self-inflicted injury among others. Future studies should examine factors contributing to alcohol use disorder and barriers to accessing and using mental health care.

A one-pot Pd- and P450-catalyzed chemoenzymatic synthesis of a library of oxyfunctionalized biaryl alkanoic acids leveraging a substrate anchoring approach.

A one-pot chemoenzymatic approach was developed by combining Palladium-catalysis with selective cytochrome P450 enzyme oxyfunctionalization. Various iodophenyl alkanoic acids could be coupled with alkylphenyl boronic acids to generate a series of alkyl substituted biarylalkanoic acids in overall high yield. The identity of the products could be confirmed by various analytical and chromatographic techniques. Addition of an engineered cytochrome P450 heme domain mutant with peroxygenase activity upon completion of the chemical reaction resulted in the selective oxyfunctionalization of those compounds, primarily at the benzylic position. Moreover, in order to increase the biocatalytic product conversion, a reversible substrate engineering approach was developed. This involves the coupling of a bulky amino acid such as L- phenylalanine or tryptophan, to the carboxylic acid moiety. The approach resulted in a 14 to 49% overall biocatalytic product conversion increase associated with a change in regioselectivity of hydroxylation towards less favored positions.