1,875 research outputs found
An Investigation of Biochar Removal Systems for Pyrolysis Reactors
Fluidized bed biomass pyrolysis is a process that is becoming popular for the conversion of agricultural, municipal and forestry residues into liquid bio-oils, solid biochar and gaseous products. Bio-oil vapors leave the reactor vessel with the produced gases. Also produced however, is a low density biochar particles which accumulate in the bed. Though some fine biochar particles can be elutriated, a significant amount remains in the bed. Accumulation of biochar leads to poor process stability and defluidization of the bed. Moreover, biochar may have negative effects on the pyrolysis reactions. In the current implementation of a mobile pyrolysis unit, the biochar is removed intermittently from the fluidized bed by stopping biomass feeding, and reducing the fluidization velocity to promote segregation, allowing subsequent removal of the biochar layer with a vacuum line.
The initial of objective of this thesis was the optimization and quantification of the performance of the batch biochar removal process. The second objective was to develop a new, continuous biochar removal system.
A batch process using particle separation through density and removal with overflow ports during fluidization, was used to quantify the amount of disruption to fluidization from different loadings and sizes of biochar, therefore determining the feasibility of a batch removal. The main problem encountered with the batch removal was the inconsistent bed composition throughout the removal process, which can reduce the yield of valuable liquid product. The knowledge acquired during the optimization of the batch process was used to design a novel continuous system. The novel continuous system operated at steady state and allowed for high purity biochar removal, and was more than capable of continuously removing the biochar
generated in a practical pyrolysis process. This novel system has been included for use in a full- scale pyrolysis unit, since it will allow the unit to run continuously while controlling the concentration of biochar within the pyrolysis reactor
Does Nursing Bias Affect Patients: A Quality Improvement Project
Nursing bias topics to be touched on will be bias from nurses towards patients with the following:
• substance abuse history
• mental disorders
• different races/ethnicities
• sexual orientations
It is important to address the problem of nursing bias towards certain people primarily because it is affecting patient care/patient outcomes.https://scholarworks.moreheadstate.edu/celebration_posters_2024/1012/thumbnail.jp
Effect of Spatial Inhomogeneities on the Membrane Surface on Receptor Dimerization and Signal Initiation
Important signal transduction pathways originate on the plasma membrane, where microdomains may transiently entrap diffusing receptors. This results in a non-random distribution of receptors even in the resting state, which can be visualized as “clusters” by high resolution imaging methods. Here, we explore how spatial in-homogeneities in the plasma membrane might influence the dimerization and phosphorylation status of ErbB2 and ErbB3, two receptor tyrosine kinases that preferentially heterodimerize and are often co-expressed in cancer. This theoretical study is based upon spatial stochastic simulations of the two-dimensional membrane landscape, where variables include differential distributions and overlap of transient confinement zones (“domains”) for the two receptor species. The in silico model is parameterized and validated using data from single particle tracking experiments. We report key differences in signaling output based on the degree of overlap between domains and the relative retention of receptors in such domains, expressed as escape probability. Results predict that a high overlap of domains, which favors transient co-confinement of both receptor species, will enhance the rate of hetero-interactions. Where domains do not overlap, simulations confirm expectations that homo-interactions are favored. Since ErbB3 is uniquely dependent on ErbB2 interactions for activation of its catalytic activity, variations in domain overlap or escape probability markedly alter the predicted patterns and time course of ErbB3 and ErbB2 phosphorylation. Taken together, these results implicate membrane domain organization as an important modulator of signal initiation, motivating the design of novel experimental approaches to measure these important parameters across a wider range of receptor systems
Efetividade do hipoclorito de sódio usado isoladamente ou em associação com o EDTA sobre a difusão de íons hidroxila liberados de pasta de hidróxido de cálcio
AIM: To evaluate the effect of different irrigant solutions employed during removal and replacement of calcium hydroxide paste on the diffusion of hydroxyl ions through root canal dentine in vitro. METHODOLOGY: Thirty-five maxillary and mandibular human canines with straight and fully developed roots were used. After mechanical preparation up to 1mm short of tooth length, 30 canals were filled with calcium hydroxide paste and 5 canals were left empty; all teeth had their coronal accesses properly sealed. Teeth were placed in plastic containers with distilled water, and pH was read after 30 days when the paste from 20 teeth was renewed. After removal of the paste by endodontic instrumentation and irrigation with distilled water, canals were replenished with newly mixed paste in Group 1 and 2. In these groups, final irrigation was conducted with 5 mL of EDTA followed by 5 mL of NaOCl in specimens in Group 1, and 5 mL of NaOCl only in specimens in Group 2. In 10 teeth the paste was not replenished at 30 days (Group 3). All specimens were returned to the containers with fresh distilled water, and the pH was recorded after another 30 days. The differences between the first (30d) and second (60d) pH readings were calculated and submitted to analysis of variance and individual comparisons using the Scheffeé's test. RESULTS: Results of mean analysis on differences of pH readings showed that greater diffusion had occurred on specimens in Group 3. Individual comparisons using Scheffeé's test showed statistical significance between Groups 2 and 3, and equivalence between all other groups. CONCLUSION: It was concluded that the use of EDTA did not enhance diffusion of hydroxyl ions through root canal dentine.OBJETIVO: O objetivo desta pesquisa foi comparar o efeito de diferentes irrigantes, usados durante a troca da pasta de hidróxido de cálcio, sobre a difusão de íons hidroxila. METODOLOGIA: Foram empregados 35 caninos humanos, com canais retos e raízes totalmente formadas. Efetuado o preparo mecânico até 1 mm aquém do comprimento do dente, 30 canais foram preenchidos com pasta de hidróxido de cálcio e 5 permaneceram vazios (controle). Após o selamento, os dentes foram colocados em frascos plásticos contendo água destilada. Passados 30 dias, o pH da água foi medido e a pasta de 20 dentes foi renovada. Depois de removê-la com água destilada e instrumentos endodônticos e, antes de repô-la, foi feita uma irrigação com 5 ml de EDTA seguida de 5 ml de NaOCl (Grupo 1) ou somente com 5 ml de NaOCl (Grupo 2). Em 10 dentes, a pasta não foi renovada (Grupo 3). Os dentes foram repostos em seus frascos com nova água destilada e, após 30 dias, o pH foi novamente registrado. As diferenças nas medidas de pH, realizadas aos 30 e 60 dias, foram calculadas e submetidas à análise de variância e a comparações individuais pelo teste de Scheffeé. RESULTADOS: A análise das diferenças mostrou que a difusão foi maior nos dentes do Grupo 3. Comparações individuais usando o teste de Scheffeé mostraram significância estatística entre os Grupos 2 e 3 e equivalência entre todos os outros grupos. CONCLUSÃO: O uso do EDTA não aumentou a difusão de íons hidroxila através da dentina radicular
Practice Variation in the Immediate Postoperative Care of Pediatric Kidney Transplantation: A National Survey
Introduction
Advances in organ allocation, surgical technique, immunosuppression, and long-term follow-up have led to a significant improvement in kidney transplant outcomes. Although there are clear recommendations for several aspects of kidney transplant management, there are no pediatric-specific guidelines for immediate postoperative care. The aim of this survey is to examine practice variations in the immediate postoperative care of pediatric kidney transplant patients.
Methods
We surveyed medical directors of Pediatric Acute Lung Injury and Sepsis Investigators (PALISI)-affiliated pediatric intensive care units regarding center-specific immediate postoperative management of pediatric kidney transplantation.
Results
The majority of PALISI centers admit patients to the pediatric intensive care unit postoperatively, and 97% of the centers involve a pediatric nephrologist in immediate postoperative care. Most patients undergo invasive hemodynamic monitoring; 97% of centers monitor invasive arterial blood pressure and 88% monitor central venous pressure. Most centers monitor serum electrolytes every 4 to 6 hours. Wide variation exists regarding blood pressure goal, fluid replacement type, frequency of obtaining kidney ultrasound, and use of prophylactic anticoagulation.
Conclusion
There is consistent practice across PALISI centers in regards to many aspects of immediate postoperative management of pediatric kidney transplantation. However, variation still exists in some management aspects that warrant further discussions to reach a national consensus
SARS-CoV-2 Antibody Prevalence Among Healthcare Workers and First Responders, Florida, May-June, 2020
Background: The SARS-CoV-2 virus responsible for severe respiratory infection associated with coronavirus disease 2019 (COVID-19) was first confirmed in Florida on March 1, 2020. Responding to the pandemic, multi-agency collaborative partnerships put in place actions integrating point-of-care antibody testing at established large-scale COVID-19 testing sites where the baseline seropositivity of COVID-19 in health care workers and first responders in Florida at the start of the pandemic was established.
Purpose: Determine the seropositivity of healthcare workers and first responders at five drive thru testing sites using a rapid SARS-CoV-2 antibody test in Florida from May 6 through June 3, 2020.
Methods: The first drive-thru SARS-CoV-2 antibody test site was opened at Miami Hard Rock Stadium, May 6, 2020. Testing expanded to three additional sites on May 9, 2020: Jacksonville, Orlando, and Palm Beach. The fifth and final site, Miami Beach, began testing on May 21, 2020. Healthcare workers and first responder’s self-seeking SARS-CoV-2 testing were designated for antibody testing and completed a laboratory collection form on-site for the point-of-care test. All testing was performed on whole blood specimens (obtained by venipuncture) using the Cellex Inc. qSARS-CoV-2 IgG/IgM Rapid Test. Seropositivity was assessed by univariate analysis and by logistic regression including the covariates age, sex, race/ethnicity, and testing location.
Results and Discussion: As of June 3, 2020, of 5,779 healthcare workers and first responders tested, 4.1% were seropositive (range 2.6–8.2%). SARS-COV-2 antibody tests had higher odds of being positive for persons testing at the Miami Hard Rock Stadium (aOR 2.24 [95% C.I. 1.48-3.39]), persons of Haitian/Creole ethnicity (aOR 3.28 [95% C.I. 1.23-8.72]), Hispanic/Latino(a) ethnicity (aOR 2.17 [95% C.I. 1.50-3.13], and Black non-Hispanic persons (aOR 1.63 [95% C.I. 1.08-2.46]). SARS-COV-2 antibody prevalence among first responders and healthcare workers in five sites in Florida varied by race and ethnicity and by testing location
Pharmacopuncture with a low dosage of B complex vitamins in the Da Zhui acupoint (Governing Vessel 14) for controlling gastrointestinal parasitism in periparturient ewes
Gastrointestinal parasites are a significant challenge in sheep farming, and periparturient ewes are one of the most susceptible categories in sheep flocks. This study aimed to verify whether the injection of B vitamins at the acupuncture point governing vessel 14 (GV14) can influence the parasitic load or host parasite interaction in naturally infected ewes during the peripartum period. Four weeks before parturition, 25 ewes were divided into five treatment groups: (1) Dose Control: 0.2 mL of B complex via IM; (2) Drug Control: 2 mL Complex B via IM; (3) Acupoint Control: 0.2 mL of Water at GV14 point; (4) Control; (5) Test group: 0.2 mL of B complex at the GV14 point. Treatments were performed at weeks -3, -1, 2, 4, and 6 about the parturition time. Fecal samples to estimate the parasitic load by fecal egg counts (FEC) and total blood samples for hemogram examination were performed seven days after the treatment, coinciding with weeks -2, 3, 5, and 7 about the parturition time. The number of peripheral eosinophils was higher in group 3 than in group 1 (p <0.05). Although groups 3 and 5 had lower mean values of FEC and higher hematological values at the time of weaning, these differences were not statistically significant (p> 0.05) according to the F test. However, all animals in groups 3 and 5 maintained low parasitism levels until the end of the experiment. Further studies should be performed with larger sample sizes and minor changes to the experimental protocol to elucidate the role of GV14 acupoint stimulation in the host-parasite relationship.A parasitose gastrointestinal é o principal desafio sanitário para a criação de ovinos a pasto, e as ovelhas no periparto são uma das categorias mais susceptíveis a esta infeção no rebanho. O objetivo deste trabalho foi verificar se a injeção de vitaminas do complexo B no acuponto Vaso Governador 14 (VG14) poderia influenciar a carga parasitária ou modular a interação hospedeiro-parasito em ovelhas naturalmente infectadas no período de periparto. Quatro semanas antes da data prevista para o parto, 25 ovelhas foram divididas em cinco grupos de tratamento (1) Controle da dose: 0,2 mL de vitaminas do complexo B via IM; (2) Controle do fármaco: 2mL complexo B via IM; (3) Controle do Ponto: 0,2 mL de água destilada no ponto VG14; (4) Controle sem tratamento; (5) Grupo teste: 0,2 mL de complexo B no pontoVG14. Estes tratamentos foram realizados nas semanas -3; -1; 2; 4 e 6 em relação à data do parto. Amostras de fezes para contagem de ovos por grama de fezes (OPG), assim como amostras de sangue para realizar o hemograma, foram obtidas dos animais sete dias após os tratamentos, coincidindo com as semanas -2, 3, 5 e 7 do parto. O número de eosinófilos periféricos foi superior no grupo 3 se comparado ao grupo 1 (p <0,05). Os animais dos grupos 3 e 5 tiveram menores valores de OPG e maior hematócrito, mas estas diferenças não foram consideradas significativas pelo teste F (p> 0,05). No entanto, todas as ovelhas dos grupos 3 e 5 se mantiveram com níveis baixos de parasitismo durante todo o experimento. Sugere-se que novos estudos sejam realizados com algumas modificações deste protocolo a fim de aprofundar o conhecimento do potencial imunomodulador do acuponto VG14
Characterization of an Oct1 orthologue in the channel catfish, Ictalurus punctatus: A negative regulator of immunoglobulin gene transcription?
BACKGROUND: The enhancer (Eμ3') of the immunoglobulin heavy chain locus (IGH) of the channel catfish (Ictalurus punctatus) has been well characterized. The functional core region consists of two variant Oct transcription factor binding octamer motifs and one E-protein binding μE5 site. An orthologue to the Oct2 transcription factor has previously been cloned in catfish and is a functionally active transcription factor. This study was undertaken to clone and characterize the Oct1 transcription factor, which has also been shown to be important in driving immunoglobulin gene transcription in mammals. RESULTS: An orthologue of Oct1, a POU family transcription factor, was cloned from a catfish macrophage cDNA library. The inferred amino acid sequence of the catfish Oct1, when aligned with other vertebrate Oct1 sequences, revealed clear conservation of structure, with the POU specific subdomain of catfish Oct1 showing 96% identity to that of mouse Oct1. Expression of Oct1 was observed in clonal T and B cell lines and in all tissues examined. Catfish Oct1, when transfected into both mammalian (mouse) and catfish B cell lines, unexpectedly failed to drive transcription from three different octamer-containing reporter constructs. These contained a trimer of octamer motifs, a fish V(H )promoter, and the core region of the catfish Eμ3' IGH enhancer, respectively. This failure of catfish Oct1 to drive transcription was not rescued by human BOB.1, a co-activator of Oct transcription factors that stimulates transcription driven by catfish Oct2. When co-transfected with catfish Oct2, Oct1 reduced Oct2 driven transcriptional activation. Electrophoretic mobility shift assays showed that catfish Oct1 (native or expressed in vitro) bound both consensus and variant octamer motifs. Putative N- and C-terminal activation domains of Oct1, when fused to a Gal4 DNA binding domain and co-transfected with Gal4-dependent reporter constructs were transcriptionally inactive, which may be due in part to a lack of residues associated with activation domain function. CONCLUSION: An orthologue to mammalian Oct1 has been found in the catfish. It is similar to mammalian Oct1 in structure and expression. However, these results indicate that the physiological functions of catfish Oct1 differ from those of mammalian Oct1 and include negative regulation of transcription
Crown discoloration promoted by materials used in regenerative endodontic procedures and effect of dental bleaching: spectrophotometric analysis
Regenerative endodontic procedure (REP) has been proposed as a new approach to treat immature permanent teeth. However, materials used in REP for root canal disinfection or cervical sealing may induce tooth discoloration. Objectives To assess tooth crown’s color after intracanal treatment with triple antibiotic paste (TAP) or calcium hydroxide (CH); cervical sealing with glass ionomer cement (GIC) or mineral trioxide aggregate (MTA); and bleaching with carbamide peroxide. Material and Methods After pulp removal and color spectrophotometer measurement, 50 bovine incisors were divided into 4 experimental groups and one control (untreated). Experiments were performed in phases (Ph). Ph1: TAP (ciprofloxacin, metronidazole, minocycline), TAPM (ciprofloxacin, metronidazole, amoxicillin), DAP (ciprofloxacin, metronidazole), or CH treatment groups. After 1 and 3 days (d); 1, 2, 3 weeks (w); and 1, 2, 3 and 4 months (m), color was measured and medications were removed. Ph2: GIC or MTA cervical sealing, each using half of the specimens from each group. Color was assessed after 1d, 3d; 1w, 2w, 3w; 1m and 2m. Ph3: Two bleaching sessions, each followed by color measurement. Data were analyzed with ANOVA and post-hoc Holm-Sidak method. Results Ph1: Specimens of TAP group presented higher color alteration (ΔE) mean than those of TAPM group. No significant difference was found among TAP or TAPM and CH, DAP or Control groups. Ph2: cervical sealing materials showed no influence on color alteration. Ph3: Different ΔE means (from different groups), prior to bleaching, became equivalent after one bleaching session. Conclusions TAP induces higher color alteration than TAPM; color alteration increases over time; cervical sealing material has no influence on color alteration; and, dental bleaching was able to recover, at least partially, the tooth crown’s color
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