Mixed-Valence Iron Complexes Containing End-On Bridging Cyaphide Ions.

Iron cyanide compounds are among the oldest known synthetic coordination compounds, dating back to the early 18th century. By contrast, iron complexes of the cyaphide ion (C≡P-)─a heavy valence isoelectronic analog of the cyanide ion─are unknown. Herein we report the synthesis of highly stable mono- and bis-cyaphide complexes of iron(II), namely Fe(depe)2(Cl)(CP) and Fe(depe)2(CP)2 (depe = 1,2-bis(diethylphosphino)ethane). These iron(II) cyaphide complexes are capable of further coordination to iron(I) in a hitherto unknown linear coordination geometry, affording the conjugated multimetallic mixed-valence complexes [{Fe(depe)2}2(µ-CP)(N2)][BArF4]2 and [{Fe(depe)2}3(µ-CP)2][OTf]2.

Implications of Measles Inclusion by Commercial Syndromic Polymerase Chain Reaction Panels - United States, May 2022-April 2023.

Syndromic polymerase chain reaction (PCR) panels are used to test for pathogens that can cause rash illnesses, including measles. Rash illnesses have infectious and noninfectious causes, and approximately 5% of persons experience a rash 7-10 days after receipt of a measles, mumps, and rubella (MMR) vaccine. MMR vaccine includes live attenuated measles virus, which is detectable by PCR tests. No evidence exists of person-to-person transmission of measles vaccine virus, and illness does not typically result among immunocompetent persons. During September 2022-January 2023, the Tennessee Department of Health received two reports of measles detected by syndromic PCR panels. Both reports involved children (aged 1 and 6 years) without known risk factors for measles, who were evaluated for rash that occurred 11-13 days after routine MMR vaccination. After public health responses in Tennessee determined that both PCR panels had detected measles vaccine virus, six state health departments collaborated to assess the frequency and characteristics of persons receiving a positive measles PCR panel test result in the United States. Information was retrospectively collected from a commercial laboratory testing for measles in syndromic multiplex PCR panels. During May 2022-April 2023, among 1,548 syndromic PCR panels, 17 (1.1%) returned positive test results for measles virus. Among 14 persons who received a positive test result and for whom vaccination and case investigation information were available, all had received MMR vaccine a median of 12 days before specimen collection, and none had known risk factors for acquiring measles. All positive PCR results were attributed to detection of measles vaccine virus. Increased awareness among health care providers about potential measles detection by PCR after vaccination is needed. Any detection of measles virus by syndromic PCR testing should be immediately reported to public health agencies, which can use measles vaccination history and assessment of risk factors to determine the appropriate public health response. If a person recently received MMR vaccine and has no risk factors for acquiring measles, additional public health response is likely unnecessary.

Introducing a machine learning algorithm for delirium prediction-the Supporting SURgery with GEriatric Co-Management and AI project (SURGE-Ahead).

INTRODUCTION: Post-operative delirium (POD) is a common complication in older patients, with an incidence of 14-56%. To implement preventative procedures, it is necessary to identify patients at risk for POD. In the present study, we aimed to develop a machine learning (ML) model for POD prediction in older patients, in close cooperation with the PAWEL (patient safety, cost-effectiveness and quality of life in elective surgery) project. METHODS: The model was trained on the PAWEL study's dataset of 878 patients (no intervention, age ≥ 70, 209 with POD). Presence of POD was determined by the Confusion Assessment Method and a chart review. We selected 15 features based on domain knowledge, ethical considerations and a recursive feature elimination. A logistic regression and a linear support vector machine (SVM) were trained, and evaluated using receiver operator characteristics (ROC). RESULTS: The selected features were American Society of Anesthesiologists score, multimorbidity, cut-to-suture time, estimated glomerular filtration rate, polypharmacy, use of cardio-pulmonary bypass, the Montreal cognitive assessment subscores 'memory', 'orientation' and 'verbal fluency', pre-existing dementia, clinical frailty scale, age, recent falls, post-operative isolation and pre-operative benzodiazepines. The linear SVM performed best, with an ROC area under the curve of 0.82 [95% CI 0.78-0.85] in the training set, 0.81 [95% CI 0.71-0.88] in the test set and 0.76 [95% CI 0.71-0.79] in a cross-centre validation. CONCLUSION: We present a clinically useful and explainable ML model for POD prediction. The model will be deployed in the Supporting SURgery with GEriatric Co-Management and AI project.

Hydrogenation Reactions with Heterobimetallic Complexes.

Hydrogenations are fundamentally and industrially important reactions that are atom economical paths to synthesize value-added products from feedstock chemicals. The cooperative effects of two or more metal centers in multimetallic active sites is a successful strategy to activate small molecules and facilitate catalytic reactions, and this strategy has been recently applied to catalytic hydrogenation reactions. Furthermore, heterobimetallic complexes have been well-documented to provide novel reaction pathways and improved selectivity, compared to their homo-bimetallic and monometallic analogues. This minireview provides a historical perspective on the development of heterobimetallic catalysts for the hydrogenation of unsaturated substrates and describes recent developments in this burgeoning research area.

Food and Drug Administration Approval of Artesunate for Severe Malaria: Enough to Achieve Best Practice?

Intravenous artesunate has been the global standard of care for severe malaria for over 2 decades. Yet, until recently, artesunate has only been available to patients through an expanded-access protocol from the Centers for Disease Control and Prevention. In May 2020, the Food and Drug Administration approved artesunate, allowing US hospitals to stock the drug and ensuring prompt treatment for this life-threatening infection. However, because of artesunate's high cost and the infrequency of severe malaria in the United States, hospitals may be reluctant to stock the drug. As US health systems weigh the decision to stock artesunate, we propose a hospital tier framework to inform this decision and support clinicians caring for patients who present with severe malaria.

Comparison of Illumina and Oxford Nanopore Technology for genome analysis of Francisella tularensis, Bacillus anthracis, and Brucella suis.

BACKGROUND: Bacterial epidemiology needs to understand the spread and dissemination of strains in a One Health context. This is important for highly pathogenic bacteria such as Bacillus anthracis, Brucella species, and Francisella tularensis. Whole genome sequencing (WGS) has paved the way for genetic marker detection and high-resolution genotyping. While such tasks are established for Illumina short-read sequencing, Oxford Nanopore Technology (ONT) long-read sequencing has yet to be evaluated for such highly pathogenic bacteria with little genomic variations between strains. In this study, three independent sequencing runs were performed using Illumina, ONT flow cell version 9.4.1, and 10.4 for six strains of each of Ba. anthracis, Br. suis and F. tularensis. Data from ONT sequencing alone, Illumina sequencing alone and two hybrid assembly approaches were compared. RESULTS: As previously shown, ONT produces ultra-long reads, while Illumina produces short reads with higher sequencing accuracy. Flow cell version 10.4 improved sequencing accuracy over version 9.4.1. The correct (sub-)species were inferred from all tested technologies, individually. Moreover, the sets of genetic markers for virulence, were almost identical for the respective species. The long reads of ONT allowed to assemble not only chromosomes of all species to near closure, but also virulence plasmids of Ba. anthracis. Assemblies based on nanopore data alone, Illumina data alone, and both hybrid assemblies correctly detected canonical (sub-)clades for Ba. anthracis and F. tularensis as well as multilocus sequence types for Br. suis. For F. tularensis, high-resolution genotyping using core-genome MLST (cgMLST) and core-genome Single-Nucleotide-Polymorphism (cgSNP) typing produced highly comparable results between data from Illumina and both ONT flow cell versions. For Ba. anthracis, only data from flow cell version 10.4 produced similar results to Illumina for both high-resolution typing methods. However, for Br. suis, high-resolution genotyping yielded larger differences comparing Illumina data to data from both ONT flow cell versions. CONCLUSIONS: In summary, combining data from ONT and Illumina for high-resolution genotyping might be feasible for F. tularensis and Ba. anthracis, but not yet for Br. suis. The ongoing improvement of nanopore technology and subsequent data analysis may facilitate high-resolution genotyping for all bacteria with highly stable genomes in future.

Si-H Bond Activation and Dehydrogenative Coupling of Silanes across the Iron-Amide Bond of a Bis(amido)bis(phosphine) Iron(II) Complex.

Despite the utility of Si-Si bonds, there are relatively few examples of Si-Si bond formation by base metals. In this work, a four-coordinate iron complex, (PNNP)FeII, is shown to strongly activate the Si-H bonds in primary silanes across the Fe-amide bonds in a metal-ligand cooperative fashion. Upon treatment with excess silane, Si-Si dehydrogenative homocoupling is shown to occur across the Fe-Namide bond without concomitant oxidation and spin state changes at the Fe center.

The effectiveness and cost-effectiveness of clinical fracture-risk assessment tools in reducing future osteoporotic fractures among older adults: a structured scoping review.

This scoping review described the use, effectiveness, and cost-effectiveness of clinical fracture-risk assessment tools to prevent future osteoporotic fractures among older adults. Results show that the screening was not superior in preventing all osteoporosis-related fractures to usual care. However, it positively influenced participants' perspectives on osteoporosis, may have reduced hip fractures, and seemed cost-effective. PURPOSE: We aim to provide a synopsis of the evidence about the use of clinical fracture-risk assessment tools to influence health outcomes, including reducing future osteoporotic fractures and their cost-effectiveness. METHODS: We followed the guidelines of Arksey and O'Malley and their modifications. A comprehensive search strategy was created to search CINAHL, Medline, and Embase databases until June 29, 2021, with no restrictions. We critically appraised the quality of all included studies. RESULTS: Fourteen studies were included in the review after screening 2484 titles and 68 full-text articles. Four randomized controlled trials investigated the effectiveness of clinical fracture-risk assessment tools in reducing all fractures among older women. Using those assessment tools did not show a statistically significant reduction in osteoporotic fracture risk compared to usual care; however, additional analyses of two of these trials showed a trend toward reducing hip fractures, and the results might be clinically significant. Four studies tested the impact of screening programs on other health outcomes, and participants reported positive results. Eight simulation studies estimated the cost-effectiveness of using these tools to screen for fractures, with the majority showing significant potential savings. CONCLUSION: According to the available evidence to date, using clinical fracture-risk assessment screening tools was not more effective than usual care in preventing all osteoporosis-related fractures. However, using those screening tools positively influenced women's perspectives on osteoporosis, may have reduced hip fracture risk, and could potentially be cost-effective. This is a relatively new research area where additional studies are needed.

Early and Increased Influenza Activity Among Children - Tennessee, 2022-23 Influenza Season.

Influenza seasons typically begin in October and peak between December and February (1); however, the 2022-23 influenza season in Tennessee began in late September and was characterized by high pediatric hospitalization rates during November. This report describes a field investigation conducted in Tennessee during November 2022, following reports of increasing influenza hospitalizations. Data from surveillance networks, patient surveys, and whole genome sequencing of influenza virus specimens were analyzed to assess influenza activity and secondary illness risk. Influenza activity increased earlier than usual among all age groups, and rates of influenza-associated hospitalization among children were high in November, reaching 12.6 per 100,000 in children aged <5 years, comparable to peak levels typically seen in high-severity seasons. Circulating influenza viruses were genetically similar to vaccine components. Among persons who received testing for influenza at outpatient clinics, children were twice as likely to receive a positive influenza test result as were adults. Among household contacts exposed to someone with influenza, children were more than twice as likely to become ill compared with adults. As the influenza season continues, it is important for all persons, especially those at higher risk for severe disease, to protect themselves from influenza. To prevent influenza and severe influenza complications, all persons aged ≥6 months should get vaccinated, avoid contact with ill persons, and take influenza antivirals if recommended and prescribed.

Clinical practice guideline for management of osteoporosis and fracture prevention in Canada: 2023 update.

BACKGROUND: In Canada, more than 2 million people live with osteoporosis, a disease that increases the risk for fractures, which result in excess mortality and morbidity, decreased quality of life and loss of autonomy. This guideline update is intended to assist Canadian health care professionals in the delivery of care to optimize skeletal health and prevent fractures in postmenopausal females and in males aged 50 years and older. METHODS: This guideline is an update of the 2010 Osteoporosis Canada clinical practice guideline on the diagnosis and management of osteoporosis in Canada. We followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework and quality assurance as per Appraisal of Guidelines for Research and Evaluation (AGREE II) quality and reporting standards. Primary care physicians and patient partners were represented at all levels of the guideline committees and groups, and participated throughout the entire process to ensure relevance to target users. The process for managing competing interests was developed before and continued throughout the guideline development, informed by the Guideline International Network principles. We considered benefits and harms, patient values and preferences, resources, equity, acceptability and feasibility when developing recommendations; the strength of each recommendation was assigned according to the GRADE framework. RECOMMENDATIONS: The 25 recommendations and 10 good practice statements are grouped under the sections of exercise, nutrition, fracture risk assessment and treatment initiation, pharmacologic interventions, duration and sequence of therapy, and monitoring. The management of osteoporosis should be guided by the patient's risk of fracture, based on clinical assessment and using a validated fracture risk assessment tool. Exercise, nutrition and pharmacotherapy are key elements of the management strategy for fracture prevention and should be individualized. INTERPRETATION: The aim of this guideline is to empower health care professionals and patients to have meaningful discussions on the importance of skeletal health and fracture risk throughout older adulthood. Identification and appropriate management of skeletal fragility can reduce fractures, and preserve mobility, autonomy and quality of life.

Synthesis, Characterization, and Reactivity of a (PPP) Pincer-Ligated Manganese Carbonyl Complex: Polarity Reversal Imparted by the Electrophilic Nature of a Planar Mn-P(NR2)2 Fragment.

The bonding interactions of a synthesized pincer-ligated manganese dicarbonyl complex featuring an N-heterocyclic phosphenium (NHP+) central moiety are explored. The pincer ligand [PPP]Cl was coordinated to a manganese center using Mn(CO)5Br and 254 nm light to afford the chlorophosphine complex (PPClP)Mn(CO)2Br (2) as a mixture of halide exchange products and stereoisomers. The target dicarbonyl species (PPP)Mn(CO)2 (3) was prepared by treatment of 2 with 2 equiv of the reductant KC8. Computational investigations and analysis of structural parameters were used to elucidate multiple bonding interactions between the Mn center and the PNHP atom in 3. The generation of a product of formal H2 addition, (PPHP)Mn(CO)2H (4), was achieved through the dehydrogenation of NH3BH3, affording a 2:1 mixture of 4syn:4anti stereoisomers. The nucleophilic nature of the Mn center and the electrophilic nature of the PNHP moiety were demonstrated through hydride addition and protonation of 3 to produce K(THF)2[(PPHP)Mn(CO)2] (6) and (PPClP)Mn(CO)2H (5), respectively. The observed reactivity suggests that 3 is best described as a Mn-I/NHP+ complex, in contrast to pincer-ligated dicarbonyl manganese analogues typically assigned as MnI species.

One Bridge, Three Bonds: A Frontier in Multiple Bonding in Heterobimetallic Complexes.

A single bridging phosphinoamide ligand was shown to support a metal-metal triple bond in a Zr/Co heterobimetallic complex. The similarity of the bonding in this compound to previously synthesized Zr/Co species, and therefore the assignment of the Zr/Co triple bond, is supported by the structural parameters of the complex, the electronic structure predicted by density functional theory, and complete-active-space self-consistent-field (CASSCF) calculations. This demonstrates that metal-metal multiple bonds can be realized in heterobimetallic complexes without multiple bridging ligands to enforce the proximity of the two metals.

The relationship between pre-surgery self-rated health and changes in functional and mental health in older adults: insights from a prospective observational study.

BACKGROUND: Elective surgeries are among the most common health stressors in later life and put a significant risk at functional and mental health, making them an important target of research into healthy aging and physical resilience. Large-scale longitudinal research mostly conducted in non-clinical samples provided support of the predictive value of self-rated health (SRH) for both functional and mental health. Thus, SRH may have the potential to predict favorable adaptation processes after significant health stressors, that is, physical resilience. So far, a study examining the interplay between SRH, functional and mental health and their relative importance for health changes in the context of health stressors was missing. The present study aimed at addressing this gap. METHODS: We used prospective data of 1,580 inpatients (794 complete cases) aged 70 years or older of the PAWEL study, collected between October 2017 and May 2019 in Germany. Our analyses were based on SRH, functional health (Barthel Index) and self-reported mental health problems (PHQ-4) before and 12 months after major elective surgery. To examine changes and interrelationships in these health indicators, bivariate latent change score (BLCS) models were applied. RESULTS: Our analyses provided evidence for improvements of SRH, functional and mental health from pre-to-post surgery. BLCS models based on complete cases and the total sample pointed to a complex interplay of SRH, functional health and mental health with bidirectional coupling effects. Better pre-surgery SRH was associated with improvements in functional and mental health, and better pre-surgery functional health and mental health were associated with improvements in SRH from pre-to-post surgery. Effects of pre-surgery SRH on changes in functional health were smaller than those of functional health on changes in SRH. CONCLUSIONS: Meaningful changes of SRH, functional and mental health and their interplay could be depicted for the first time in a clinical setting. Our findings provide preliminary support for SRH as a physical resilience factor being associated with improvements in other health indicators after health stressors. Longitudinal studies with more timepoints are needed to fully understand the predictive value of SRH for multidimensional health. TRIAL REGISTRATION: PAWEL study, German Clinical Trials Register, number DRKS00013311. Registered 10 November 2017 - Retrospectively registered, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00013311 .

Frailty index and its association with the onset of postoperative delirium in older adults undergoing elective surgery.

BACKGROUND: The association of frailty based on the accumulation of deficits with postoperative delirium (POD) has been poorly examined. We aimed to analyze this association in older patients undergoing elective surgery. METHODS: Preoperative data was used to build a 30-item frailty index (FI) for participants of the PAWEL-study. Delirium was defined by a combination of I-CAM and chart review. Using logistic regressions models we analysed the association between frailty and POD adjusting for age, sex, smoking, alcohol consumption, education and type of surgery. RESULTS: Among 701 participants (mean age 77.1, 52.4% male) median FI was 0.27 (Q1 0.20| Q3 0.34), with 528 (75.3%) frail participants (FI ≥ 0.2). Higher median FI were seen in orthopedic than cardiac surgery patients (0.28 versus 0.23), and in women (0.28 versus 0.25 in men). Frail participants showed a higher POD incidence proportion (25.4% versus 17.9% in non-frail). An increased odds for POD was observed in frail versus non-frail participants (OR 2.14 [95% CI 1.33, 3.44], c-statistic 0.71). A 0.1 increment of FI was associated with OR 1.57 [95% CI 1.30, 1.90] (c-statistic 0.72) for POD. No interaction with sex or type of surgery was detected. Adding timed-up-and-go-test and handgrip strength to the FI did not improve discrimination. CONCLUSION: Our data showed a significant association between frailty defined through a 30-item FI and POD among older adults undergoing elective surgery. Adding functional measures to the FI did not improve discrimination. Hence, our preoperative 30-item FI can help to identify patients with increased odds for POD. TRIAL REGISTRATION: PAWEL and PAWEL-R (sub-) study were registered on the German Clinical Trials Register (number DRKS00013311 and DRKS00012797).

Cognitive function in older patients and their stress challenge using different anesthesia regimes: a single center observational study.

BACKGROUND: With increasing age older patients are at higher risk for cognitive decline after surgery. Even tailored anesthesia procedures in older patients remain a high risk for postoperative cognitive disorder. Additional stress derived from anxiety and anesthesia itself can negatively impact postoperative cognitive outcomes. The objective of this study was to evaluate the impact of general versus regional anesthesia on postoperative cognitive disorder and indicators of perioperative stress in elderly undergoing surgery. METHODS: In this single center prospective study between December 2014 and November 2015, 46 patients aged 50 to 85 years undergoing dermatology surgery were enrolled. Patients were stratified by receiving general versus regional nerve anesthesia. On three consecutive days, saliva cortisol levels were analyzed three times per day. Cognitive function was assessed on the day before and the day after surgery using comprehensive neuropsychological testing of multiple cognitive functions including memory, executive function, attention and processing speed. RESULTS: Comparing the regional anesthesia group (RAG, n = 28) with the general anesthesia group (GAG, n = 18) no significant difference in the postoperative cognitive function was observed. However, patients in the GAG had significantly higher postoperative cortisol levels when compared to patients in the RAG. In both groups, a peak of cortisol value was detected on the day of surgery, which was higher in the GAG in comparison to the RAG. CONCLUSIONS: We did not observe a difference in postoperative cognitive function between patients undergoing regional or general anesthesia for dermatology surgery. However, we found lower cortisol level in the RAG. Based on these findings, future studies should investigate alternatives to reduce stress in a general anesthesia setting. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02505815.

Electronic and Structural Variations of a Nickel(0) N-Heterocyclic Phosphenium Complex in Comparison to Group 10 Analogues.

The bonding interactions and electronic structure of a diphosphine pincer ligand featuring an N-heterocyclic phosphenium/phosphido (NHP±) central moiety with nickel are explored. Treating Ni(COD)2 with the pincer ligand [PPP]Cl in the presence of a two-electron phosphine donor ligand PMe3 generates chlorophosphine complex (PPClP)Ni(PMe3) (2a). The cationic Ni complex [(PPP)Ni(PMe3)][BPh4] (3a) can be prepared by subsequent halide abstraction from 2a with NaBPh4. The assignment of 3a as a Ni0/NHP+ complex, based on analysis of structural parameters and computational investigations, lies in contrast to its previously reported group 10 MII/NHP- (M = Pd, Pt) analogues. The activation of O-H bonds across the Ni-PNHP bond is demonstrated by the addition of isopropanol to afford the metal hydride species [(PPOiPrP)Ni(PMe3)(H)][BPh4] (4). Notably, the installation of a P-H bond in the NHP unit by treatment of 2a with LiAlH4 yields (PPHP)Ni(PMe3) (6). The ambiphilic nature of the P-H bond was demonstrated through reactivity studies of P-H bond cleavage in comparison to a Pd analogue (PPHP)Pd(PPh3) (8).

Antifungal drug price increases in the United States, 2000-2019.

BACKGROUND: Antifungal drugs treat a variety of conditions, ranging from localised dermatologic disease to life-threatening systemic infections. Some common antifungal drugs experienced large price increases in recent years, however, factors contributing to these price increases are poorly understood. We sought to examine trends in antifungal drug prices and determine underlying drivers of price changes. METHODS: Antifungal drug products in the United States were identified using the Food and Drug Administration (FDA) Label database. For each product, we determined the wholesale acquisition cost per unit over time between 2000 and 2019, adjusting for inflation, and examined variables that could impact price: route of administration, number of FDA indications, the quantity of professional guideline recommendations, use for prophylaxis, number of FDA-approved manufacturers, and whether it was compounded. Price trajectories were clustered into four groups: (1) stable, 2) moderate, (3) high, and (4) extreme price increases. RESULTS: Of 139 identified drug products, one outlier was removed due to exorbitant price increases. Cluster 1 (n = 31) demonstrated the most stable prices with a 25% mean price increase. Clusters 2 (n = 97), 3 (n = 7), and 4 (n = 3) demonstrated moderate, high, and extreme price increases with 52%, 318%, and 900% mean price increases, respectively. Atypical routes of administration and compounding were over-represented in clusters 3 and 4. There was no correlation between the number of manufacturers and price changes. CONCLUSIONS: Antifungal drugs exhibited large, inflation-adjusted price increases. Atypical routes of administration and compounding were over-represented within clusters exhibiting extraordinary price increases. Our data support policies aiming to curb large price increases for medically important drugs.

Hospital pharmacy acquisition of nonstocked antimicrobials-current processes and areas for improvement.

BACKGROUND: The delivery of prompt and appropriate antimicrobial therapy for life-threatening infections is an important antimicrobial stewardship measure and a priority for hospitals. OBJECTIVES: To better understand U.S. hospital pharmacy stocking processes and acquisition of nonstocked antimicrobials and to identify strategies for improving this process. METHODS: This mixed-methods study recruited infectious diseases and antimicrobial stewardship pharmacists. Semistructured interviews with pharmacists in Minnesota were conducted via video conferencing software from January 21, 2021, to March 17, 2021. Audio recordings of the interviews guided survey development and were also transcribed, coded, and qualitatively analyzed. Surveys were distributed throughout the United States via an e-mail listserv, and responses were collected between August 5, 2021, and September 15, 2021. RESULTS: Ten interviews and 78 surveys were included in the analysis. Formulary and stocking practices varied based on institution. Stocking decisions were most frequently based on the frequency of use, clinical utility, and cost of antimicrobials. Nonstocked antimicrobials were often ordered from the wholesale distributor but, if needed urgently, acquired from another local institution. Antibacterial agents were the most frequently needed nonstocked antimicrobials, especially those targeting multidrug-resistant gram-negative bacteria. When acquiring nonstocked antimicrobials, barriers include process inefficiencies, cost, availability, and safety concerns. Improved information sharing between local institutions may help improve this process. CONCLUSION: In this exploratory study, antimicrobial stocking practices varied within U.S. hospitals. Acquisition of nonstocked, urgently needed antimicrobials from neighboring hospitals may be common; however, this process lacks guidance and is often inefficient. Establishing better mechanisms for information sharing may improve this process and should be explored.

Nickel-Templated Replacement of Phosphine Substituents in a Tetradentate Bis(amido)bis(phosphine) Ligand.

The replacement of phosphine substituents in nickel-bound PNNP ligands is reported as an alternative method for preparing multidentate phosphine ligands with alkyl substituents. Treatment of the previously reported bis(phosphide) complex {K(THF)x}22Ph[PNNP]Ni (2) with 2 equiv of MeI, iPrI, and 1,3-dibromoethane formed alkyl-substituted complexes 2Ph,2Me[PNNP]Ni (3), 2Ph,2iPr[PNNP]Ni (4), and 2Ph,propylene[PNNP]Ni (5), respectively. The stereoselectivity (racemic vs meso) of these reactions can be controlled by varying the reaction temperature. The racemic mixtures of products with the new alkyl substituents in an anti configuration were favored at lower temperatures, whereas a larger proportion of meso compounds was acquired at higher temperatures. Further treatment of 3 with KH resulted in selective elimination of the remaining phenyl groups rather than the methyl substituents, affording bis(methylphosphide) complex {K(THF)x}22Me[PNNP]Ni (6). Subsequent treatment of 6 with additional MeI formed 4Me[PNNP]Ni (7), in which all four phenyl groups were replaced with methyl substituents. As a proof of concept, demetalation of the ligand from 7 was achieved using aqueous KCN to form a free dimethylphosphine-substituted ligand H24Me[PNNP] (8), and 8 was subsequently coordinated to a different metal, using PdCl2 to form 4Me[PNNP]Pd (9). Unlike the clean elimination of phenyl substituents from 3, the reactions of KH with 4 and 5 exhibited competitive elimination of both alkyl and phenyl substituents and/or attenuated reactivity.

Studying dynamic aroma release by headspace-solid phase microextraction-gas chromatography-ion mobility spectrometry (HS-SPME-GC-IMS): method optimization, validation, and application.

To understand aroma perception from complex food matrices' determination of dynamic aroma release during simulated oral processing is necessary. In this study optimization, validation and application of a novel method coupling headspace-solid phase microextraction (HS-SPME) with gas chromatography-ion mobility spectrometry (GC-IMS) is presented. Thirteen character impact compounds imparting different chemical properties are studied to understand capabilities and limitations of the method. It was shown for the first time that the temperature of the IMS sample inlet can be increased up to 200 °C without instrumental constraints. Linear calibration was possible for eleven of the thirteen compounds with one decade dynamic range. The limit of detection and quantitation were 2.1-63.0 ppb and 7.2-210.1 ppb, respectively. Diacetyl could be detected in negative polarity mode of IMS, however with lower precision compared to the compounds detected in positive mode. Limitations of the method were short HS-SPME extraction time, which in the case of caproic acid was not sufficient for reliable quantification. Additionally, δ-decalactone could not be detected due to maximum GC temperature of 200 °C. Application of the method to determine dynamic aroma release from a dairy matrix was successfully shown for nine compounds. Analysis of complex food matrix was performed with similar precision compared to analysis in aqueous solution, thus proving high robustness of the method towards matrix effects.