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Purpose: To assess care home and staff characteristics associated with task-focused (TF) and relationship-centred care (RCC) mealtime practices prior to the COVID-19 pandemic.Methods: Staff working in Canadian and American care homes were invited to complete a 23-item online survey assessing their perceptions of mealtime care, with one item assessing 26 potential care practices from the Mealtime Relational Care Checklist (relationship-centred = 15; task-focused = 11) reported to occur in the home prior to the pandemic. Multivariate linear regression evaluated staff and care home characteristics associated with mealtime practices.Results: Six hundred and eighty-six respondents completed all questions used in this analysis. Mean TF and RCC mealtime practices were 4.89 ± 1.99 and 9.69 ± 2.96, respectively. Staff age was associated with TF and RCC practices with those 40-55 years reporting fewer TF and those 18-39 years reporting fewer RCC practices. Those providing direct care were more likely to report TF practices. Dissatisfaction with mealtimes was associated with more TF and fewer RCC practices. Homes that were not making changes to promote RCC pre-pandemic had more TF and fewer RCC practices. Newer care homes were associated with more RCC, while small homes (≤49 beds) had more TF practices.Conclusions: Mealtime practices are associated with staff and home factors. These factors should be considered in efforts to improve RCC practices in Canadian homes.
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COVID-19 , Comidas , Humanos , Canadá , Persona de Mediana Edad , Adulto , Anciano , Femenino , Masculino , SARS-CoV-2 , Hogares para Ancianos , Encuestas y Cuestionarios , Adulto Joven , Casas de Salud , Estados Unidos , Adolescente , Pandemias , Atención Dirigida al PacienteRESUMEN
PROBLEM: In the United States, physician bias is exhibited early in medical training and contributes to systemic inequities within the field of medicine. A lack of diversity, equity, inclusion, and antiracism (DEI-AR) content within medical curricula drives critical gaps in knowledge and deficiencies when preparing medical students to serve patients of diverse backgrounds. At the Mayo Clinic Alix School of Medicine (MCASOM), student-led curricular reviews between 2017 to 2018 and 2020 to 2021 revealed opportunities to improve DEI-AR content within preclinical courses. Course directors expressed concern of limited expertise and time to enact effective changes. APPROACH: The MCASOM DEI-AR teaching assistant (TA) program aims to curate a collaborative partnership between course directors and compensated student TAs to facilitate course enhancements responsive to the prior preclinical course review while centering standardized DEI-AR best practices. OUTCOMES: As of January 2024, the program has engaged 14 TAs and partnered with 24 preclinical courses. Postcourse student evaluation responses were collected from 8 courses for 2021 to 2022 (before enhancements) and 2022 to 2023 (after enhancements). Student satisfaction with DEI-AR content is tracked through postcourse evaluations, with preliminary data demonstrating improvement after DEI-AR curricular integration (improvement of mean preenhancement and postenhancement scores of 3.81 to 4.05; t12 = 1.79, P = .21). Qualitative student comments were sorted into general categories of positive, negative, or neutral, showing a 6.25% median increase in positive perception of DEI. NEXT STEPS: Plans for the MCASOM DEI-AR TA program include application of quality improvement strategies to improve program processes and outcomes. Development of a centralized dashboard that integrates course enhancement progress and ongoing feedback from evaluations is anticipated to facilitate this effort. The program additionally aims to develop partnerships with clinical clerkships, which would allow for a more comprehensive enhancement of the overall medical education experience related to DEI-AR.
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Limited mineralization of organic phosphorus to phosphate during the anaerobic digestion process poses a significant challenge in the development of cost-effective nutrient recovery strategies from anaerobically digested poultry wastewater (ADPW). This study investigated the influence of organic acids on phosphorus solubilization from ADPW, followed by its recycling in the form of struvite using a bubble column electrolytic reactor (BCER) without adding chemicals. The impact of seeding on the efficiency of PO43- and NH3-N recovery as well as the size distribution of recovered precipitates from the acid pre-treated ADPW was also evaluated. Pre-treatment of the ADPW with oxalic acid achieved complete solubilization of phosphorus, reaching â¼100% extraction efficiency at pH 2.5. The maximum removal efficiency of phosphate and ammonia-nitrogen from the ADPW were 88.9% and 90.1%, respectively, while the addition of 5 and 10 g/L struvite seed to the BCER increased PO43- removal efficiency by 9.6% and 11.5%, respectively. The value of the kinetic rate constant, k, increased from 0.0176 min-1 (unseeded) to 0.0198 min-1, 0.0307 min-1, and 0.0375 min-1 with the seed loading rate of 2, 5, and 10 g/L, respectively. Concurrently, the average particle size rose from 75.3 µm (unseeded) to 82.1 µm, 125.7 µm, and 148.9 µm, respectively. Results from XRD, FTIR, EDS, and dissolved chemical analysis revealed that the solid product obtained from the recovery process was a multi-nutrient fertilizer consisting of 94.7% struvite with negligible levels of heavy metals.
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Aves de Corral , Aguas Residuales , Animales , Estruvita , Fosfatos/análisis , Fósforo/análisis , Compuestos Orgánicos , Nutrientes/análisis , Precipitación QuímicaRESUMEN
Tissue adhesives are promising alternatives to sutures and staples for joining tissues, sealing defects, and immobilizing devices. However, existing adhesives mostly take the forms of glues or hydrogels, which offer limited versatility. We report a direct-ink-write 3D printable tissue adhesive which can be used to fabricate bioadhesive patches and devices with programmable architectures, unlocking new potential for application-specific designs. The adhesive is conformable and stretchable, achieves robust adhesion with wet tissues within seconds, and exhibits favorable biocompatibility. In vivo rat trachea and colon defect models demonstrate the fluid-tight tissue sealing capability of the printed patches, which maintained adhesion over 4 weeks. Moreover, incorporation of a blood-repelling hydrophobic matrix enables the printed patches to seal actively bleeding tissues. Beyond wound closure, the 3D printable adhesive has broad applicability across various tissue-interfacing devices, highlighted through representative proof-of-concept designs. Together, this platform offers a promising strategy toward developing advanced tissue adhesive technologies.
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Adhesivos Tisulares , Ratas , Animales , Adhesivos Tisulares/química , Adhesivos , Hidrogeles/química , TecnologíaRESUMEN
BACKGROUND AND OBJECTIVES: Meals in long-term care (LTC) are essential to residents not only for nutrition and their physical well-being but also for their social interactions supporting resident quality of life. This study aims to understand the mealtime experiences of residents and family care partners during the coronavirus 2019 disease (COVID-19) pandemic when restrictions were put in place in LTC and retirement homes. RESEARCH DESIGN AND METHODS: Interpretive description analysis of qualitative interviews in LTC and retirement homes, with 17 family care partners and 4 residents. Convenience and snowball sampling was used to recruit participants for telephone interviews. RESULTS: Three themes were generated. Compromised mealtimes mean compromising community-meals were seen by participants as a key social and community-building event of the home; they reported this loss of community with pandemic restrictions. Participants noted that family care partners are indispensable at meals for social, psychological, and physical support. The dangers of eating alone spoke to the social isolation reported by participants that occurred during the pandemic and the risks they described of eating alone. DISCUSSION AND IMPLICATIONS: This study confirms the importance of mealtimes in LTC and retirement homes to community building and extends our understanding of the importance of family inclusion at meals and why eating alone, as happened during COVID-19, was so detrimental to residents. Effort needs to be made to value this communal activity for the well-being of residents.
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COVID-19 , Cuidados a Largo Plazo , Comidas , Casas de Salud , Investigación Cualitativa , Humanos , COVID-19/epidemiología , COVID-19/psicología , Femenino , Masculino , Comidas/psicología , Anciano , Anciano de 80 o más Años , Familia/psicología , SARS-CoV-2 , Hogares para Ancianos , Aislamiento Social/psicología , Calidad de Vida , Pandemias , Cuidadores/psicologíaRESUMEN
We present the first known case of a patient with BRD2::NUTM1-driven NUT carcinoma. A 59-year-old woman presented with poorly differentiated squamous cell lung cancer metastatic to the pleura. Eventually, a positive NUT immunohistochemistry, NUT fluorescence in situ hybridization, and RNA next-generation sequencing with a BRD2::NUTM1 fusion led to the diagnosis of NUT carcinoma. She received multiple lines of chemotherapy with response and is still alive at 2 years postdiagnosis. This report expands on the known fusions in NUT carcinoma and highlights potential differences in patient prognosis on the basis of gene fusion partners.
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The neocortex is the region that most distinguishes human brain from other mammals and primates [Annu Rev Genet. 2021 Nov;55(1):555-81]. Studying the development of human cortex is important in understanding the evolutionary changes occurring in humans relative to other primates, as well as in elucidating mechanisms underlying neurodevelopmental disorders. Cortical development is a highly regulated process, spatially and temporally coordinated by expression of essential transcriptional factors in response to signaling pathways [Neuron. 2019 Sep;103(6):980-1004]. Enhancers are the most well-understood cis-acting, non-protein-coding regulatory elements that regulate gene expression [Nat Rev Genet. 2014 Apr;15(4):272-86]. Importantly, given the conservation of both DNA sequence and molecular function of the majority of proteins across mammals [Genome Res. 2003 Dec;13(12):2507-18], enhancers [Science. 2015 Mar;347(6226):1155-9], which are far more divergent at the sequence level, likely account for the phenotypes that distinguish the human brain by changing the regulation of gene expression. In this review, we will revisit the conceptual framework of gene regulation during human brain development, as well as the evolution of technologies to study transcriptional regulation, with recent advances in genome biology that open a window allowing us to systematically characterize cis-regulatory elements in developing human brain [Hum Mol Genet. 2022 Oct;31(R1):R84-96]. We provide an update on work to characterize the suite of all enhancers in the developing human brain and the implications for understanding neuropsychiatric disorders. Finally, we discuss emerging therapeutic ideas that utilize our emerging knowledge of enhancer function.
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Elementos de Facilitación Genéticos , Trastornos del Neurodesarrollo , Animales , Humanos , Elementos de Facilitación Genéticos/genética , Regulación de la Expresión Génica , Primates , MamíferosRESUMEN
We introduce an explainable deep neural architecture that combines brain structure with genetic influence to improve disease severity prediction in Alzheimer's disease. Our framework consists of an encoder, a decoder, and a rank-consistent ordinal regression module. The encoder projects neural imaging and genetics data into a low-dimensional latent space regularized by the decoder. The ordinal regression module guides the feature embedding process to find discriminative patterns representative of disease severity. We also add a learnable dropout layer that learns feature importance and extracts explainable biomarkers from the data. We evaluate our model using structural MRI (sMRI) and Single Nucleotide Polymorphism (SNP) data provided by the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. In 2-class severity classification comparison, our model has a median F-score of 0.86 (baseline median F-score range: 0.57-0.81). In 3-class classification comparison, our model's median F-score is 0.50 (baseline range: 0.17 - 0.41). In 4-class classification comparison, our model's median F-score is 0.40 (baseline range: 0.14 - 0.39). We demonstrate that our model provides improved disease diagnosis alongside sparse and clinically relevant biomarkers.Clinical relevance-This study provides a deep-learning model that can predict Alzheimer's disease severity levels while identifying consistent and clinically relevant biomarkers.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Aprendizaje Profundo , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/genética , Neuroimagen/métodos , BiomarcadoresRESUMEN
Bioadhesives have emerged as transformative and versatile tools in healthcare, offering the ability to attach tissues with ease and minimal damage. These materials present numerous opportunities for tissue repair and biomedical device integration, creating a broad landscape of applications that have captivated clinical and scientific interest alike. However, fully unlocking their potential requires multifaceted design strategies involving optimal adhesion, suitable biological interactions, and efficient signal communication. In this Review, we delve into these pivotal aspects of bioadhesive design, highlight the latest advances in their biomedical applications, and identify potential opportunities that lie ahead for bioadhesives as multifunctional technology platforms.
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Adhesivos Tisulares , Materiales Biocompatibles , TecnologíaRESUMEN
Mind-body interventions such as mindfulness-based stress reduction (MBSR) may improve well-being by increasing awareness and regulation of physiological and cognitive states. However, it is unclear how practice may alter long-term, baseline physiological processes, and whether these changes reflect improved well-being. Using respiration rate (RR), which can be sensitive to effects of meditation, and 3 aspects of self-reported well-being (psychological well-being [PWB], distress, and medical symptoms), we tested pre-registered hypotheses that: (1) Lower baseline RR (in a resting, non-meditative state) would be a physiological marker associated with well-being, (2) MBSR would decrease RR, and (3) Training-related decreases in RR would be associated with improved well-being. We recruited 245 adults (age range = 18-65, M = 42.4): experienced meditators (n = 42), and meditation-naïve participants randomized to MBSR (n = 72), active control (n = 41), or waitlist control (n = 66). Data were collected at pre-randomization, post-intervention (or waiting), and long-term follow-up. Lower baseline RR was associated with lower psychological distress among long-term meditators (p* = 0.03, b = 0.02, 95% CI [0.01, 0.03]), though not in non-meditators prior to training. MBSR decreased RR compared to waitlist (p = 0.02, Cohen's d = - 0.41, 95% CI [- 0.78, - 0.06]), but not the active control. Decreased RR related to decreased medical symptoms, across all participants (p* = 0.02, b = 0.57, 95% CI [0.15, 0.98]). Post-training, lower RR was associated with higher PWB across training groups compared to waitlist (p* = 0.01, b = 0.06, 95% CI [0.02, 0.10]), though there were no significant differences in change in PWB between groups. This physiological marker may indicate higher physical and/or psychological well-being in those who engage in wellness practices.
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Meditación , Distrés Psicológico , Adulto , Humanos , Adolescente , Adulto Joven , Persona de Mediana Edad , Anciano , Autoinforme , Frecuencia Respiratoria , Examen FísicoRESUMEN
Pathogenic Escherichia coli and Salmonella enterica pose serious public health threats due to their ability to cause severe gastroenteritis and life-threatening sequela, particularly in young children. Moreover, the emergence and dissemination of antibiotic resistance in these bacteria have complicated control of infections. Alternative strategies that effectively target these enteric pathogens and negate or reduce the need of antibiotics are urgently needed. Such an alternative is the CRISPR-Cas9 system because it can generate sequence-specific lethal double stranded DNA breaks. In this study, two self-transmissible broad host range conjugative plasmids, pRK24 and pBP136, were engineered to deliver multiplexed CRSIPR-Cas9 systems that specifically target Enterohemorrhagic and Enteropathogenic strains of E. coli (EHEC and EPEC), S. enterica, and blaCMY-2 antibiotic resistance plasmids. Using in vitro mating assays, we show that the conjugative delivery of pRK24-CRISPR-Cas9 carrying guide RNAs to the EPEC/EHEC eae (intimin) gene can selectively kill enterohemorrhagic E. coli O157 eae+ cells (3 log kill at 6 h) but does not kill the isogenic Δeae mutant (P<0.001). Similar results were also obtained with a pBP136 derivative, pTF16, carrying multiplexed guide RNAs targeting E. coli eae and the S. enterica ssaN gene coding for the type III secretion ATPase. Another pBP136 derivative, TF18, carries guide RNAs targeting S. enterica ssaN and the antibiotic resistance gene, blaCMY-2, carried on the multi-drug resistant pAR06302. Introduction of pTF18 into bacteria harboring pAR06302 showed plasmids were cured at an efficiency of 53% (P<0.05). Using a murine neonate EPEC infection model, pTF16 was delivered by a murine derived E. coli strain to EPEC infected mice and showed significant reductions of intestinal EPEC (P<0.05). These results suggest that establishing conjugative CRISPR-Cas9 antimicrobials in the intestinal microbiome may provide protection from enteric pathogens and reduce antibiotic resistance without disrupting the normal microbiota.
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Escherichia coli Enterohemorrágica , Escherichia coli O157 , Gastroenteritis , Animales , Ratones , Sistemas CRISPR-Cas/genética , Ingeniería , Escherichia coli Enterohemorrágica/genética , Antibacterianos/farmacología , Farmacorresistencia MicrobianaRESUMEN
Bioelectronic implants could use semiconductors that adhere to wet, dynamic tissues.
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Prótesis e Implantes , Semiconductores , Adhesivos Tisulares , Humanos , Animales , PorcinosRESUMEN
Mealtimes in long-term care (LTC) can reinforce relationships between staff and residents through relationship-centred care (RCC) practices; however, meals are often task-focused (TF). This cross-sectional study explores multi-level contextual factors that contribute to RCC and TF mealtime practices. Secondary data from residents in 32 Canadian LTC homes were analyzed (n = 634; mean age 86.7 ± 7.8; 31.1% male). Data included resident health record review, standardized mealtime observation tools, and valid questionnaires. A higher average number of RCC (9.6 ± 1.4) than TF (5.6 ± 2.1) practices per meal were observed. Multi-level regression revealed that a significant proportion of variation in the RCC and TF scores was explained at the resident- (intraclass correlation coefficient [ICC]RCC = 0.736; ICCTF = 0.482), dining room- (ICCRCC = 0.210; ICCTF = 0.162), and home- (ICCRCC = 0.054; ICCTF = 0.356) levels. For-profit status and home size modified the associations between functional dependency and practices. Addressing multi-level factors can reinforce RCC practices and reduce TF practices.
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Carcinoma de Células Renales , Neoplasias Renales , Humanos , Masculino , Anciano , Anciano de 80 o más Años , Femenino , Cuidados a Largo Plazo , Análisis de Datos Secundarios , Estudios Transversales , Canadá , ComidasRESUMEN
This study performed co-digestion of poultry litter (PL) with wheat straw in the daily anaerobic sequencing batch reactor considering operation parameters of carbon-to-nitrogen ratio (C/N, 11.6 to 28.4), total solids (TS, 2.6 to 9.4%), and hydraulic retention time (HRT, 7.6 to 24.4d). The inoculum with a diverse microbial community structure included 2% of methanogens (Methanosaeta) was chosen. Experimental performance by central composite design showed continuous methane production with the highest biogas production rate (BPR) obtained at C/N = 20, TS = 6%, and HRT = 7.6d, being (1.18 ± 0.14 L/LR/d). A significant modified quadratic model (p < 0.0001) for predicting BPR was built (R2 = 0.9724). The operation parameters and process stability both affected the release of nitrogen, phosphorus, and magnesium in the effluent. The results provided new support for the novel reactor operations for efficient bioenergy production from PL and agricultural wastes.
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Carbono , Aves de Corral , Animales , Anaerobiosis , Triticum/química , Nitrógeno/análisis , Metano , Biocombustibles , Digestión , Reactores BiológicosRESUMEN
OBJECTIVES: Targeted therapies for blastic plasmacytoid dendritic cell neoplasm (BPDCN) have presented a diagnostic dilemma for differentiating residual BPDCN from reactive plasmacytoid dendritic cells (pDCs) because these conditions have a similar immunoprofile, necessitating discovery of additional diagnostic markers. METHODS: Fifty cases of BPDCN involving bone marrow (26/50) and skin (24/50) as well as other hematologic malignancies (67) and nonneoplastic samples (37) were included. Slides were stained using a double-staining protocol for the following immunohistochemical marker combinations: TCF4/CD123, TCF4/CD56, SOX4/CD123, and IRF8/CD123. RESULTS: The nuclear marker SOX4 is expressed in neoplastic pDCs; in our cohort, SOX4/CD123 showed 100% sensitivity and 98% specificity in distinguishing BPDCN from reactive pDCs and other neoplasms. TCF4/CD56 had a 96% sensitivity and 100% specificity for BPDCN. IRF8 is a nonspecific marker that is positive in BPDCN and pDCs as well as other myeloid malignancies. CONCLUSIONS: The novel immunohistochemical combination SOX4/CD123 distinguishes BPDCN, including CD56-negative BPDCN, from both reactive pDCs and other neoplasms. Because of their high diagnostic sensitivity and specificity, the double-staining marker combinations TCF4/CD123, TCF4/CD56, and SOX4/CD123 can be used to confirm lineage in BPDCN cases and detect minimal/measurable residual disease in tissue specimens.
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Neoplasias Hematológicas , Neoplasias Cutáneas , Humanos , Subunidad alfa del Receptor de Interleucina-3/metabolismo , Neoplasias Hematológicas/patología , Médula Ósea/patología , Células Dendríticas/metabolismo , Células Dendríticas/patología , Neoplasias Cutáneas/patología , Factores Reguladores del Interferón , Factores de Transcripción SOXCRESUMEN
In this study, different micro-aeration (MA) strategies for anaerobic digestion (AD) of poultry litter (PL) and wheat straw (WS) were examined. MA at different stages (pretreatment, middle, pretreatment plus middle, and daily) in batch AD of WS showed that daily MA had the highest increase (16.5 %) of the cumulative methane yield (CMY) compared to the control. Batch co-digestion (Co-AD) of WS and PL with daily MA obtained a furtherly improved (15.1 %) CMY of 225.44 N mL CH4/g vS added. The modified Gompertz model and Cone model were good in fitting the methane yield kinetics of MA engaged AD process (R2 greater than 0.99). Daily MA shortened the lag phase of Co-AD by 3.4 %. The sequencing batch reactor for the Co-AD of WS and PL showed an increased (21.5 %) daily methane yield when 0.5-h/d MA was employed. The results provided support for the application of micro-aeration in the AD of agricultural wastes.
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Aves de Corral , Triticum , Animales , Anaerobiosis , Cinética , MetanoRESUMEN
Diminishing phosphorus resources worldwide requires developing new technologies to recover phosphorus (P) from wastewaters. A lab-scale electrolytic reactor with a magnesium anode was investigated to remove NH4+ and PO43- from synthetic wastewater by producing struvite. The effects of mixing speed, pH, and applied current on struvite yield, NH4+, and PO43- removal efficiencies were first evaluated using a factorial design. Then, the two most significant parameters were further optimized using Central Composite Design (CCD) coupled with Response Surface Methodology (RSM). The struvite was characterized by SEM, XRD, and FT-IR. A 5.7-fold increase in struvite yield was achieved by increasing the applied current from 0.1 to 0.5 A. The three regression equations generated by the CCD/RSM design with applied current and mixing speed as the two independent parameters were highly correlated with the response variables (struvite yield, NH4+ and PO43- removal efficiencies). The desirability analysis showed the best operating condition: current, 0.5 A and mixing speed, 414 rpm, for the reactor system, under which the optimal struvite yield and NH4+ and PO43- removal efficiencies were 4.75 g/L, 93.0%, and 58.4%, respectively. The SEM, XRD, and FT-IR analyses confirmed the high purity and quality of the struvite produced by the electrolytic reactor system.
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Magnesio , Aguas Residuales , Estruvita/química , Magnesio/química , Espectroscopía Infrarroja por Transformada de Fourier , Fósforo/química , Electrodos , Fosfatos/químicaRESUMEN
Although the value of family caregivers' involvement with relatives in long-term care (LTC) is well recognized, tensions remain regarding their role. Such tensions were exacerbated during the COVID-19 pandemic as strict public health measures restricted family access to LTC homes. Using interpretive description, we examined the impact of visitation restrictions on family caregivers' experiences caring for a relative in LTC between March 2020 and June 2021. In-depth interviews were conducted with 14 family caregivers (five spouses and nine adult daughters) and two key themes were identified. The first theme, "seeking to maintain relational continuity," illustrates how caregivers sought to sustain connections with residents prior to and during the pandemic. The second theme, "disrupted relational continuity," highlights the impact of severed relational connections on caregivers' sense of self and ongoing feelings of loss and anger. Findings call for a trauma-informed approach that recognizes the pervasiveness of trauma for family caregivers and the avoidance of re-traumatization.
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COVID-19 , Cuidados a Largo Plazo , Adulto , Humanos , Pandemias , Salud Pública , CuidadoresRESUMEN
This study evaluated Al-based coagulants for turbidity removal optimization in drinking water facility using Jar test and CCD/RSM analysis. The wide use of aluminum salts requires researching improved Al-based coagulants to reduce the treatment dosage. Eight polyaluminum chloride coagulants (PACl), i.e., Hyperlon 4064-PACl 2, Hyperlon 4393, 1757 X1, 1757 XL8- PACl 1, Ultrafloc 1406, Ultrafloc 3759, AlcoPAC 6, and AlcoPAC 1010 were first compared using a series of jar tests to determine the best candidate in removing the settled and filtered turbidity in water. The results showed that all PACls performed better than alum in removing water turbidity, but Hyperlon 4064 was the best. Then, the central composite design/response surface methodology (CCD/RSM) analysis was applied to Hyperlon 4064 to optimize dosage and pH to achieve the lowest final settled and filtered turbidity in the treated water, which were 21.7 mg/L, 7.53 and 27.95 mg/L, 7.91, respectively. Two quadratic models were generated by the CCD/RSM analysis with high correlations between the actual and predicted responses (R2 = 0.9881 and 0.9809 for final settled turbidity and final filtered turbidity). The results from this study can provide useful information to the operating water treatment plants that use Al-based coagulants to remove turbidity in water.
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Agua Potable , Purificación del Agua , Floculación , Purificación del Agua/métodosRESUMEN
Removing ammonia-nitrogen (NH3N) from wastewater is of paramount importance for wastewater treatment. In this study, a novel continuous liquid plasma process (CLPD) was evaluated to remove NH3N from synthetic wastewater. The Box-Behnken experimental design was used to optimize the main process parameters, including the initial NH3N concentration (50-200 mg/L), power input (150-300 W), and gas-flow rate (1.5-2.5 L/min), for efficient NH3N removal from wastewater. The gas-flow rate and power input were found to be significant factors affecting the removal efficiency of NH3N, whereas the initial concentration of NH3N played a vital role in determining the energy efficiency of the process. Under the optimal conditions of an initial NH3N concentration of 200 mg/L, applied power of 223 W, and gas-flow rate of 2.4 L/min, 98.91% of NH3N could be removed with a N2 selectivity of 92.91%, and the corresponding energy efficiency was 0.527 g/kWh after 2 hrs of treatment. A small fraction of undesirable NO3--N (7.05 mg/L) and NO2--N (2.83 mg/L) were also produced. Kinetic modeling revealed that NH3N degradation by the CLPD followed a pseudo-first-order reaction model, with a rate constant (k) of 0.03522 min-1. Optical emission spectroscopy (OES) was used to gather information about the active chemical species produced during the plasma discharge. The obtained spectra revealed the presence of several highly oxidative radicals, including â§OH, â§O, and â§O2+. These results demonstrate the potential of liquid phase plasma discharge as a highly efficient technology for removing ammonia from aqueous solutions.