"The Hotel of 10,000 Stars": The Impact of Social-Structural Determinants of Health Among Im/migrant Shrimpers in the Gulf of Mexico.

Objectives. To identify appropriate interventions to prevent injury, we conducted a qualitative study among commercial shrimp fishermen in the Gulf of Mexico. Methods. Using qualitative and participatory research methods, including interviews, photovoice, and workplace observations in southeast Texas and the Rio Grande Valley in Texas, we examined the social‒structural dimensions that contribute to physical and psychological injury. Results. We found that multiple layers of vulnerability and danger exist among shrimpers with interacting themes: (1) recognizing risk, (2) precarious employment, and (3) psychological distress. Conclusions. Our results add to the growing body of knowledge that emphasizes the negative health impacts of underregulated, high-risk, and physically demanding work performed primarily by im/migrants. Public Health Implications. Our findings highlight the larger social‒structural conditions and context of hardships endemic to migrant labor and suggest implications for practice and policy interventions. (Am J Public Health. 2024;114(8):824-832. https://doi.org/10.2105/AJPH.2024.307696).

Synonymous codon substitutions perturb cotranslational protein folding in vivo and impair cell fitness.

In the cell, proteins are synthesized from N to C terminus and begin to fold during translation. Cotranslational folding mechanisms are therefore linked to elongation rate, which varies as a function of synonymous codon usage. However, synonymous codon substitutions can affect many distinct cellular processes, which has complicated attempts to deconvolve the extent to which synonymous codon usage can promote or frustrate proper protein folding in vivo. Although previous studies have shown that some synonymous changes can lead to different final structures, other substitutions will likely be more subtle, perturbing predominantly the protein folding pathway without radically altering the final structure. Here we show that synonymous codon substitutions encoding a single essential enzyme lead to dramatically slower cell growth. These mutations do not prevent active enzyme formation; instead, they predominantly alter the protein folding mechanism, leading to enhanced degradation in vivo. These results support a model in which synonymous codon substitutions can impair cell fitness by significantly perturbing cotranslational protein folding mechanisms, despite the chaperoning provided by the cellular protein homeostasis network.

Properties of protein unfolded states suggest broad selection for expanded conformational ensembles.

Much attention is being paid to conformational biases in the ensembles of intrinsically disordered proteins. However, it is currently unknown whether or how conformational biases within the disordered ensembles of foldable proteins affect function in vivo. Recently, we demonstrated that water can be a good solvent for unfolded polypeptide chains, even those with a hydrophobic and charged sequence composition typical of folded proteins. These results run counter to the generally accepted model that protein folding begins with hydrophobicity-driven chain collapse. Here we investigate what other features, beyond amino acid composition, govern chain collapse. We found that local clustering of hydrophobic and/or charged residues leads to significant collapse of the unfolded ensemble of pertactin, a secreted autotransporter virulence protein from Bordetella pertussis, as measured by small angle X-ray scattering (SAXS). Sequence patterns that lead to collapse also correlate with increased intermolecular polypeptide chain association and aggregation. Crucially, sequence patterns that support an expanded conformational ensemble enhance pertactin secretion to the bacterial cell surface. Similar sequence pattern features are enriched across the large and diverse family of autotransporter virulence proteins, suggesting sequence patterns that favor an expanded conformational ensemble are under selection for efficient autotransporter protein secretion, a necessary prerequisite for virulence. More broadly, we found that sequence patterns that lead to more expanded conformational ensembles are enriched across water-soluble proteins in general, suggesting protein sequences are under selection to regulate collapse and minimize protein aggregation, in addition to their roles in stabilizing folded protein structures.

Introducing the Catalytic Amination of Silanes via Nitrene Insertion.

The direct functionalization of Si-H bonds by the nitrene insertion methodology is described. A copper(I) complex bearing a trispyrazolylborate ligand catalyzes the transfer of a nitrene group from PhI═NTs to the Si-H bond of silanes, disilanes, and siloxanes, leading to the exclusive formation of Si-NH moieties in the first example of this transformation. The process tolerates other functionalities in the substrate such as several C-H bonds and alkyne and alkene moieties directly bonded to the silicon center. Density functional theory (DFT) calculations provide a mechanistic interpretation consisting of a Si-H homolytic cleavage and subsequent rebound to the Si-centered radical.

Effects of lactic, malic and fumaric acids on Salmonella spp. counts and on chicken meat quality and sensory characteristics.

The aim of this work was to assess the effectiveness of dipping chicken breast in lactic, malic and fumaric acid 3% solutions for 15 s on Salmonella counts, as well as on chicken meat quality and sensory characteristics. All three treatments effectively reduced Salmonella counts. The values of Salmonella log reduction were 2.22, 1.55 and 1.30 log CFU/g for fumaric, malic and lactic treatments, respectively. Although fumaric acid was the most effective for reducing Salmonella counts, chicken meat quality and sensory characteristics were significantly affected, even in cooked samples. Conversely, malic and lactic acids treatments caused minimal changes in chicken meat quality and sensory characteristics compared to control samples. This study shows effective alternatives to reduce Salmonella contamination on chicken breast fillets, although further studies should be considered to improve the effects on quality and sensory attributes.

Reliability of observational- and machine-based teat hygiene scoring methodologies.

Removal of teat-end debris is one of the most critical steps in the premilking process. We aimed to estimate inter- and intra-rater reliability of an observation-based rating scale of dairy parlor worker teat-cleaning performance. A nonrandom sample of 8 experienced raters provided teat swab debris ratings scored on a 4-point ordinal visual scale for 175 teat swab images taken immediately after teat cleaning and before milking unit attachment. To overcome the uncertainty associated with visual inspection and observation-based rating scales, we assessed the reliability of an automated observer-independent method to assess teat-end debris using digital image processing and machine learning techniques to quantify the type and amount of debris material present on each teat swab image. Cohen's kappa coefficient (κ) was used to assess inter-rater score agreement on 175 teat swab images, and the intraclass correlation coefficient was used to assess both intra-rater score agreement and machine reliability. The reliability of debris scoring of teat swabs by raters was low (overall κ = 0.43), whereas the machine-based rating system demonstrated near-perfect reliability (Pearson r > 0.99). Our findings suggest that machine-based rating systems of worker performance are much more reliable than observational-based methods when evaluating premilking teat cleanliness. Teat swab image analysis technology can be further developed for training and quality control purposes to enable more efficient, reliable, and independent feedback on worker milking performance. As automated technologies are becoming more popular on dairy farms, machine-based teat cleanliness scoring could also be incorporated into automated milking systems.

Widespread position-specific conservation of synonymous rare codons within coding sequences.

Synonymous rare codons are considered to be sub-optimal for gene expression because they are translated more slowly than common codons. Yet surprisingly, many protein coding sequences include large clusters of synonymous rare codons. Rare codons at the 5' terminus of coding sequences have been shown to increase translational efficiency. Although a general functional role for synonymous rare codons farther within coding sequences has not yet been established, several recent reports have identified rare-to-common synonymous codon substitutions that impair folding of the encoded protein. Here we test the hypothesis that although the usage frequencies of synonymous codons change from organism to organism, codon rarity will be conserved at specific positions in a set of homologous coding sequences, for example to tune translation rate without altering a protein sequence. Such conservation of rarity-rather than specific codon identity-could coordinate co-translational folding of the encoded protein. We demonstrate that many rare codon cluster positions are indeed conserved within homologous coding sequences across diverse eukaryotic, bacterial, and archaeal species, suggesting they result from positive selection and have a functional role. Most conserved rare codon clusters occur within rather than between conserved protein domains, challenging the view that their primary function is to facilitate co-translational folding after synthesis of an autonomous structural unit. Instead, many conserved rare codon clusters separate smaller protein structural motifs within structural domains. These smaller motifs typically fold faster than an entire domain, on a time scale more consistent with translation rate modulation by synonymous codon usage. While proteins with conserved rare codon clusters are structurally and functionally diverse, they are enriched in functions associated with organism growth and development, suggesting an important role for synonymous codon usage in organism physiology. The identification of conserved rare codon clusters advances our understanding of distinct, functional roles for otherwise synonymous codons and enables experimental testing of the impact of synonymous codon usage on the production of functional proteins.

Combined high-dose intra-arterial and intrathecal chemotherapy for the treatment of a case of extraocular retinoblastoma.

Patients with retinoblastoma and central nervous system (CNS) involvement are rarely curable with available treatments. We designed a high-dose intra-arterial regimen targeting the ophthalmic artery and chiasm combined with intrathecal chemotherapy to treat a 4-year-old patient with retinoblastoma metastasized to the CNS. After three cycles of this regimen, including carboplatin, melphalan, and intrathecal topotecan, a partial response of the orbital tumor mass and chiasmatic lesion, and complete response in the cerebrospinal fluid and bone marrow were achieved. This new treatment strategy may be explored as a treatment component for patients with overt extraocular retinoblastoma and CNS dissemination.

Full-shift and task-specific upper extremity muscle activity among US large-herd dairy parlour workers.

US large-herd dairy parlour workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study was to estimate and compare full-shift and task-specific muscle activity of the upper extremity among parlour workers. Surface electromyography data were recorded continuously throughout a full work shift for each participant (n = 60). For a subset of participants (n = 33), muscular effort was estimated for milking task cycles. Lower muscle activity levels and higher per cent muscular rest was observed among rotary parlour participants as compared to herringbone and parallel parlour participants for anterior deltoid, forearm flexor and forearm extensor muscles. These findings suggest rotary parlours may offer workstation designs or work organisational dynamics which may be more beneficial to the health and performance of the worker, as compared to parallel or herringbone parlours. Practitioner Summary: Study findings suggest milking parlour configurations present different biomechanical demands on workers which may influence worker health and performance. Our findings will enable more informed decisions regarding both engineering (e.g. parlour configuration or milking equipment) and administrative (e.g. work organisation) control strategies for large-herd milking parlours.

Effect of a novel teat preparation system on upper extremity muscle activity among U.S. large-herd dairy parlor workers.

BACKGROUND: Dairy production in the U.S. is moving towards large-herd milking operations resulting in an increase in task specialization and work demands. Large-herd dairy parlor workers experience a high prevalence of musculoskeletal symptoms in the upper extremity. The purpose of this study is to evaluate the effects of an alternative teat scrubber (TS) cow preparation method on upper extremity muscle activity among large-herd parlor workers, as well compare to muscle activity associated with conventional manual milking tasks. METHODS: Upper extremity muscle activity was recorded among U.S. large-herd parlor workers (n = 15) using surface electromyography. Participants performed multiple task cycles, using both conventional and TS methods. Muscle activity levels were then compared across conventional manual and TS milking tasks. RESULTS: Conventional manual milking tasks of dip, strip and wipe were associated higher muscle activity levels of the upper trapezius and anterior deltoid. Biceps muscle activity was greatest during teat dip and wipe. Forearm flexor and extensor muscle activity was greatest during teat wipe and dip. The TS system resulted in more desirable anterior deltoid EMG profiles, and less desirable biceps, forearm flexor and extensor profiles. CONCLUSIONS: Results suggest that the TS system is effective in reducing anterior deltoid muscle activation levels. The TS system also appears to result in increased biceps, forearm flexor and extensor muscle activation levels. Increases in muscle activation levels could be offset by reduced repetitiveness resulting from three conventional manual milking tasks being replaced with one TS task. RELEVANCE TO INDUSTRY: If parlor production requirements (e.g., quality and onsistency) are maintained while simultaneously reducing cumulative muscle loading and worker fatigue, then TS use should be considered in milking parlor operations.

Vaccines against bovine babesiosis: where we are now and possible roads ahead.

SUMMARY Bovine babesiosis caused by the tick-transmitted haemoprotozoans Babesia bovis, Babesia bigemina and Babesia divergens commonly results in substantial cattle morbidity and mortality in vast world areas. Although existing live vaccines confer protection, they have considerable disadvantages. Therefore, particularly in countries where large numbers of cattle are at risk, important research is directed towards improved vaccination strategies. Here a comprehensive overview of currently used live vaccines and of the status quo of experimental vaccine trials is presented. In addition, pertinent research fields potentially contributing to the development of novel non-live and/or live vaccines are discussed, including parasite antigens involved in host cell invasion and in pathogen-tick interactions, as well as the protective immunity against infection. The mining of available parasite genomes is continuously enlarging the array of potential vaccine candidates and, additionally, the recent development of a transfection tool for Babesia can significantly contribute to vaccine design. However, the complication and high cost of vaccination trials hinder Babesia vaccine research, and have so far seriously limited the systematic examination of antigen candidates and prevented an in-depth testing of formulations using different immunomodulators and antigen delivery systems.

Effectiveness of Trained Community Lay Workers on Glycemic Control, Knowledge, and Self-Efficacy Among Agricultural Workers with Diabetes in the Texas Panhandle.

Systemic health barriers, economic challenges, and lack of follow-up care exacerbate self-management of chronic diseases like diabetes among Hispanic agricultural workers. The primary objective of this pilot project was to determine the benefit of using community coaches to decrease A1C levels and increase diabetes knowledge among agricultural workers with diagnosed diabetes in the Texas Panhandle. A longitudinal study design with two phases was used to create, deliver, and evaluate a diabetes coaching program. Phase 1 was the development of the program and community coaches training (n = 4). In Phase 2, the coaches then delivered the program over 12 weeks to thirteen clients. Phase 1: All coaches were Hispanic females, 28.3 (SD 3.8) years of age, half had at most a high school education level and the other half had a vocational certification (n = 4). Mean DKQ-24 score was 54.2% (SD = 29.7) at baseline and 75.0% (SD = 31.4) after training (t (4) = 4.6, P < 0.05). We observed a very large difference between mean baseline and exit DKQ-24 scores relative to the pooled standard deviation, resulting in an effect size estimate of 0.59 indicative of a medium to large learning effect. Phase 2: Clients were Hispanic Spanish-speaking, predominantly female (55%), 44.4 (SD 6.8) years of age with at most a high school level of education (88.9%) and occupations varied from dairy farm worker (33.3%), meat processing worker (33.3%), and other agriculture or manufacturing position (33.3%). The mean SKILLD score was 40.0% (SD = 28.7) at baseline, increasing to 72.2% (SD = 25.4) at 12 weeks upon completion of the coaching program (t (9) = 2.956, P < 0.05). We observed a very large difference between mean baseline and exit SKILLD scores relative to the pooled standard deviation, resulting in an effect size estimate of 1.13 indicative of a large learning effect. The mean A1C levels at baseline screening was 8.3% (SD = 3.0) and 7.6% (SD = 3.0) at exit screening, representing a 0.7% decrease (p = 0.4730). No statistically significant differences were observed between depression (p = 0.786) or anxiety (p = 1.000) measures at baseline compared to exit. Training and coaching programs for hard-to-reach agricultural and meat processing workers must be culturally, linguistically, and literacy appropriate for both coaches and clients. The program must be feasible and sustainable, focus on empowering community members, capitalize on technological advances and persisting new-normals from the COVID-19 pandemic as well as dismantle common systemic barriers to health and understanding lived-experiences of agricultural working populations in rural regions.

Pre and During COVID-19 Access to Rural Mental Health Care Among Agriculture Communities in the Rocky Mountain Region.

Death by suicide is the second leading cause of intentional injury incurred by foreign-born workers in the United States. Hispanic/Latino farmworkers are systematically excluded from important safety net programs. Drawing on interviews with 16 individuals representing various community organizations serving rural, agriculture-dependent regions in Colorado (n=9) and Utah (n=7), we describe Hispanic/Latino farmworkers' access to the mental health safety net in the Rocky Mountain Region post/during the COVID-19 pandemic. Findings inform the need for expanded safety net infrastructure and community collaborations to support farmworkers effectively now and in the case of future pandemics.

Non-invasive biomarkers for close activity monitoring in birdshot chorioretinitis: Optical coherence tomography angiography and beyond.

PURPOSE: The purpose of the study was to identify non-invasive imaging biomarkers potentially useful for close activity monitoring in birdshot chorioretinitis (BSCR). METHODS: Cross-sectional study of BSCR eyes included as per Levinson's and/or SUN criteria. Eyes were blindly classified into active or inactive groups per clinical inflammatory parameters, ultra-widefield (UWF) pseudocolour images, UWF fluorescein angiography (FA) and macular optical coherence tomography (OCT) cube. Qualitative and quantitative OCT and OCT-angiography (OCT-A) parameters at the fundus, superonasal and inferonasal fields were compared between active and inactive eyes. RESULTS: Thirty consecutive BSCR patients (60 eyes) were analysed. 28 eyes (46.66%) were from women and the overall mean age was 59.7 ± 12.3 years. Active eyes showed an abnormal retinal thickening at inferonasal field (nasal retinal thickness) and a higher averaged thickened retinal index (ATRI) (72.36 active vs. 20.12 inactive, p < 0.0001). A significant moderate correlation was observed between ATRI and FA scores (r = 0.259, p = 0.022). Macular vascular loops were more frequent in the superficial vascular plexus of OCT-A in the active eyes (p = 0.028). The vascular perfusion index tended to be higher in all subfields of active eyes but did not reach statistical significance. CONCLUSION: Multimodal imaging could be key to discerning activity in BSCR eyes. Higher ATRI and the presence of vascular loops in the superficial plexus are potential non-invasive activity biomarkers for the close monitoring of BSCR.

A Small Randomized Controlled Trial of Three Remote Methods to Collect Mental Health Data from Migrant Farmworker Adults.

There has been limited longitudinal study of the health of migrant farmworkers due to their migratory lifestyles and there are opportunities to test new remote data collection methods in this subpopulation. A small randomized controlled trial was conducted with 75 migrant farmworker families who were randomly assigned to one of three groups that participated by (1) telephone interview, (2) online survey, or (3) mobile app between June 2021-April 2022. Of 50 farmworker adults who completed the baseline survey, there was differential attrition with 21% of the telephone interview group, 18% of the online survey group, and 3.2% of the online app group completing the 2-month follow-up. Over this period, migrant farmworkers reported relatively few mental health problems but notable alcohol use problems. Online apps were less effective than traditional methods for remote data collection. Alcohol use problems among migrant farmworkers in the U.S. may be an issue that deserves further study.

On-Farm Health Screening Needs of Immigrant Dairy Workers in the Texas Panhandle and South Plains.

The objective of this pilot study was to determine the health needs of dairy farm workers and the feasibility of on-farm health risk screenings in the Texas Panhandle and South Plains. A cross-sectional study design was used to collect survey responses concerning health needs, occupational, and economic characteristics among 300 dairy workers between April 2020 and July 2021. Participants were predominantly immigrant Hispanic (88.8%) males (83.0%) of approximately 34.4 (SD 9.9) years of age, worked 6.0 (SD 0.4; Range 3-7) days a week and 9.9 (SD 1.5; Range 6-13) hours a day, earning a mean hourly rate of $13.40 (SD $2.80). Participants reported interest in attending on-farm health risk screenings (93.8%) as well as receiving a COVID-19 vaccine if it became available (86.4%). Health service categories were ranked from: (1st "most important") preventative care (Mean Rank 2.3), (2nd) laboratory and diagnostic care (Mean Rank 2.6), (3rd) nutritional and physical fitness support (Mean Rank 2.8), (4th) mental health care (Mean Rank 3.4), and (5th) workplace interventions (Mean Rank 3.6). Participants reported obtaining health information predominantly from internet searches (32.0%) and social media (17.7%). Findings suggest there is need and interest for on-farm health risk screenings and education among immigrant dairy workers in the Texas Panhandle-South Plains region. Addressing known barriers to health should be paramount to the organization of on-farm health risk screenings.

What Do We Know about Surface Proteins of Chicken Parasites Eimeria?

Poultry is the first source of animal protein for human consumption. In a changing world, this sector is facing new challenges, such as a projected increase in demand, higher standards of food quality and safety, and reduction of environmental impact. Chicken coccidiosis is a highly widespread enteric disease caused by Eimeria spp. which causes significant economic losses to the poultry industry worldwide; however, the impact on family poultry holders or backyard production-which plays a key role in food security in small communities and involves mainly rural women-has been little explored. Coccidiosis disease is controlled by good husbandry measures, chemoprophylaxis, and/or live vaccination. The first live vaccines against chicken coccidiosis were developed in the 1950s; however, after more than seven decades, none has reached the market. Current limitations on their use have led to research in next-generation vaccines based on recombinant or live-vectored vaccines. Next-generation vaccines are required to control this complex parasitic disease, and for this purpose, protective antigens need to be identified. In this review, we have scrutinised surface proteins identified so far in Eimeria spp. affecting chickens. Most of these surface proteins are anchored to the parasite membrane by a glycosylphosphatidylinositol (GPI) molecule. The biosynthesis of GPIs, as well as the role of currently identified surface proteins and interest as vaccine candidates has been summarised. The potential role of surface proteins in drug resistance and immune escape and how these could limit the efficacy of control strategies was also discussed.

Epidemiological Characterization of Isolates of Salmonella enterica and Shiga Toxin-Producing Escherichia coli from Backyard Production System Animals in the Valparaíso and Metropolitana Regions.

Backyard production systems (BPS) are distributed worldwide, rearing animals recognized as reservoirs of Salmonella enterica and Shiga toxin-producing Escherichia coli (STEC), both zoonotic pathogens. The aim of this study was to characterize isolates of both pathogens obtained from animals raised in BPS from two central Chile regions. The presence of pathogens was determined by bacterial culture and confirmatory PCR for each sampled BPS, calculating positivity rates. Multivariate logistic regression was used to determine risk factors. Additionally, phenotypic antimicrobial resistance was determined. A positivity rate of 2.88% for S. enterica and 14.39% for STEC was determined for the complete study region (Valparaíso and Metropolitana regions). Risk factor analysis suggests that the presence of ruminants (OR = 1.03; 95% CI = 1.002-1.075) increases the risk of STEC-positive BPS, and the presence of ruminants (OR = 1.05; 95% CI = 1.002-1.075) and the animal handlers being exclusively women (OR = 3.54; 95% CI = 1.029-12.193) increase the risk for S. enterica/STEC positivity. Eighty percent of S. enterica isolates were multidrug resistant, and all STEC were resistant to Cephalexin. This study evidences the circulation of multidrug-resistant zoonotic bacterial strains in animals kept in BPS and the presence of factors that modify the risk of BPS positivity for both pathogens.

[Long-term follow-up of tracheostomized patients post severe acquired brain injury]. / Seguimiento a largo plazo de pacientes traqueostomizados post injuria cerebral adquirida grave.

INTRODUCTION: About 50% of patients hospitalized for severe acquired brain injury require tracheostomy, and many of them need long-term care. The main objective of this study was to describe the evolution of patients with severe acquired brain injury (sABI) tracheotomized who entered rehabilitation. Secondarily, mortality related to the success or failure of decannulation and survival at 12 months of discharge were studied. METHODS: A single-center prospective observational quantitative study. Users over 18 years of age were recruited prospectively and consecutively, tracheostomized after sABI, and admitted to a rehabilitation center between April 2018 and March 2020. RESULTS: Fifty patients were included for analysis. The stay in the center was 203 (RIQ 93-320) days. At discharge to the institution, 32 (64%) patients managed to be successfully decannulated. The median number of days from admission to the center to decannulation was 49 (12-172). No decannulation failure was observed. Mortality at 12 months follow-up was 32%, five (16%) of the 32 patients who managed to be decannulated, and 11 (61%) of 18 who failed to achieve decannulation died within 12 months of follow-up. The relationship between decannulation success and mortality at 12 months of follow-up was statistically significant (p= 0.002). DISCUSSION: Addressing the decannulation process early and properly guided is relevant as it may impact long-term survival.

Introducción: Alrededor del 50% de los pacientes hospitalizados por injuria cerebral adquirida grave requieren traqueostomía y cuidados a largo plazo. El objetivo principal de este estudio fue describir la evolución de enfermos con injuria cerebral adquirida grave (ICAg) traqueostomizados que ingresaron a rehabilitación. Secundariamente se estudió el fracaso de la decanulación y la supervivencia a los 12 meses del alta. Métodos: estudio cuantitativo observacional prospectivo de centro único. Se incorporó al estudio, de forma prospectiva y consecutiva, usuarios mayores de 18 años, traqueostomizados posterior a ICAg ingresados a un centro de rehabilitación entre abril de 2018 y marzo de 2020. Resultados: se incluyeron para el análisis 50 pacientes. La estancia en el centro fue de 203 (RIQ 93-320) días. Al alta de la institución, 32 (64%) pacientes pudieron ser decanulados exitosamente. El tiempo transcurrido desde el ingreso al centro hasta la decanulación fue de 49 (12-172) días. No se observó fracaso de la decanulación. La mortalidad a los 12 meses de seguimiento fue de 32%, cinco (16%) de los 32 pacientes que pudieron ser decanulados y 11 (61%) de los 18 que no lograron la decanulación fallecieron dentro de los 12 meses de seguimiento. La relación entre la decanulación y la mortalidad a los 12 meses de seguimiento resultó estadísticamente significativa (p = 0.002). Discusión: La supervivencia global fue relativamente elevada, el proceso de decanulación resulta relevante ya que puede tener impacto en la supervivencia a largo plazo.

Non-innocent Role of the Halide Ligand in the Copper-Catalyzed Olefin Aziridination Reaction.

In the context of copper-catalyzed nitrene transfer to olefins, many systems operate upon mixing a CuX salt (X = halide, OTf) and a polydentate N-based ligand, assuming that the X ligand is displaced from the coordination sphere toward a counterion position. Herein, we demonstrated that such general assumption should be in doubt since studies carried out with the well-defined copper(I) complexes (TTM)CuCl and [(TTM)Cu(NCMe)]PF6 (TTM = tris(triazolyl)methane ligand) demonstrate a dual behavior from a catalytic and mechanistic point of view that exclusively depends on the presence or absence of the chloride ligand bonded to the metal center. When coordinated, the turnover-limiting step corresponds to the formation of the carbon-nitrene bond, whereas in its absence, the highest barrier corresponds to the formation of the copper-nitrene intermediate.