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1.
J Chromatogr A ; 1709: 464393, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37748353

RESUMEN

High temperature thermal gradient interaction chromatography (HT-TGIC) has been widely used to measure chemical composition distribution due to its applicability to separate crystalline and non-crystalline amorphous polyolefin materials. The compatibility of HT-TGIC with various detectors (infrared (IR), light scattering (LS), and viscometer) has also allowed a comprehensive analysis of molecular architecture of polyolefin and recycled plastics. The introduction of an easy-to-fabricate graphene coated onto non-porous silica particles as HT-TGIC column in 2020 showed a superior chromatographic performance over the traditional graphite column. A reduction in peak broadness (∼47 %) under identical experimental conditions was demonstrated in that research. This paper similarly uses a graphene column but with the focus on optimization of experimental parameters (concentration, and thermal cooling and heating rates etc.). Equivalent chemical composition distribution (CCD) data to that obtained by the incumbent graphite column over a wide range of polyolefins products was achieved, in addition to a shortened analysis time from 120 min down to 88 min per sample. The materials studied included semicrystalline linear low-density polyethylene (LLDPE), elastomers, terpolymers, model blends to mimic recycled plastics. The results also suggest that the elimination of substrate pores enable a better HT-TGIC separation. Coupling the ease and reproducibility of the graphene column fabrication process enables long term chromatographic robustness. This not only results in equivalent CCD data compared to the traditional graphite column but also a 27 % reduction in analysis time. These results demonstrate a substantial advancement of technology in the high throughput industrial laboratory setting where fast testing turnaround time is critical. In addition, simple fabrication with commercially available silica particles and graphene nanopowder provides a cost-effective approach to make HT-TGIC columns reproducibly.


Asunto(s)
Grafito , Temperatura , Dióxido de Silicio/química , Reproducibilidad de los Resultados , Cromatografía Líquida de Alta Presión/métodos
2.
Helicobacter ; 28(2): e12954, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36748455

RESUMEN

BACKGROUND: Helicobacter pylori (Hp) is among the most common bacterial infections in the world and one of the most common infectious agents linked to malignancy, gastric cancer (GC). Within the US there is high disparity in the rates of Hp infection and associated diseases. Hp infection is treatable, and knowledge may influence screening and treatment seeking behaviors. MATERIALS AND METHODS: In this cross-sectional study of 1042 respondents recruited from the Online Amazon MTurk platform, we sought to assess baseline knowledge of Hp and to gain insight into barriers related to Hp care. RESULTS: Just over half (52.3%) reported some prior knowledge of Hp with 11.7% (n = 122) reporting being treated for Hp themselves and 21.4% reporting family members diagnosed with Hp. Of respondents reporting prior treatment, 95 (78%) reported GI upset and 27 (21%) reported not completing medications. Specific to Hp and GC, 70% indicated that a belief that the treatment was worse than the symptoms would affect their willingness to seek care, while 81% indicated knowing Hp can cause GC would affect their treatment decisions and knowing their gastric symptoms were caused by Hp would affect their willingness to receive care. CONCLUSIONS: Knowledge of Hp in this US sample of online respondents is low and self-reported difficulties with treatment compliance is high. Increasing awareness of this infection and addressing the challenges to treatment compliance could potentially reduce rates of Hp antibiotic resistance and progression to GC or other complications of Hp infection.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Infecciones por Helicobacter/tratamiento farmacológico , Estudios Transversales , Neoplasias Gástricas/microbiología
3.
Hosp Pediatr ; 2022 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-35174385

RESUMEN

BACKGROUND: Surgical correction remains the most effective treatment of patients with severe neuromuscular scoliosis (NMS). However, postoperative inpatient clinical care after spinal surgery for NMS patients is highly complex and variable, depending on the provider and/or institution. Our project used a quality improvement methodology to implement a standardized clinical care pathway for NMS patients during their primary spinal surgery, with the global aim of decreasing postoperative hospitalized length of stay (LOS). METHODS: A multidisciplinary team developed a postoperative pathway for nonambulatory patients with NMS after their primary, nonstaged corrective spinal surgery. The outcome measure was mean LOS, and the process measure was percentage compliance with the newly implemented NMS pathway. The team used statistical process control charts and measures were evaluated over 3 phases to assess the impact of the interventions over time: pretesting, testing, and sustain. RESULTS: The mean LOS decreased from 8.0 to 5.3 days; a statistically significant change based on statistical process control chart rules. Percentage compliance with the NMS pathway improved during the testing and sustain phases, compared with the pretesting phase. LOS variability decreased from pretesting to the combined testing and sustain phases. CONCLUSIONS: Using quality improvement methodology, we successfully standardized major components of clinical care for patients with NMS after spinal corrective surgery. Through enhanced care consistency, the mean postoperative LOS decreased by nearly 3 days and decreased LOS variability. Robust multidisciplinary involvement with key stakeholders ensured sustainability of these improvements.

4.
Am Surg ; 88(2): 201-204, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33502230

RESUMEN

INTRODUCTION: Although gallbladder disease is more common in women, there is a trend toward more complicated cases in male patients. METHODS: All cholecystectomies captured by the National Surgical Quality Improvement Program database for the year 2016 were reviewed. This encompassed 38 736 records. Records were reviewed for age, sex, procedure performed, operative time, postoperative diagnosis, functional status, American Society of Anesthesiologists (ASA) class, preoperative lab values (total bilirubin, alkaline phosphatase, white blood cell count, and aspartate aminotransferase. Descriptive and inferential statistical analyses were conducted. RESULTS: Male patients are more likely to undergo cholecystectomy for a diagnosis of cholecystitis, gallstone pancreatitis, or cholangitis than women who are more likely to carry a diagnosis of biliary dyskinesia. The average operative time increases for both sexes as the patients become older. The average operative time is higher for men than women in all age groups and the variance becomes greater as the patients become older. Age, sex, postoperative diagnosis, ASA class, and functional status were all independently significant in predicting operative time. There was no difference in need for cholangiogram between the sexes. Female patients were more likely to have their cholecystectomy completed laparoscopically and they were more likely to have their surgery performed as an outpatient. CONCLUSION: These data show that women were more likely to present with uncomplicated gallbladder disease, while men were more likely to present with complicated gallbladder disease. This suggests that male patients present at a more advanced stage of disease.


Asunto(s)
Colecistectomía/estadística & datos numéricos , Enfermedades de la Vesícula Biliar/epidemiología , Factores de Edad , Procedimientos Quirúrgicos Ambulatorios/estadística & datos numéricos , Análisis de Varianza , Discinesia Biliar/epidemiología , Discinesia Biliar/cirugía , Cálculos/epidemiología , Cálculos/cirugía , Colangiografía/estadística & datos numéricos , Colangitis/epidemiología , Colangitis/cirugía , Colecistectomía/métodos , Colecistectomía Laparoscópica/estadística & datos numéricos , Colecistitis/epidemiología , Colecistitis/cirugía , Procedimientos Quirúrgicos Electivos/estadística & datos numéricos , Femenino , Enfermedades de la Vesícula Biliar/cirugía , Humanos , Masculino , Tempo Operativo , Pancreatitis/epidemiología , Distribución por Sexo , Factores Sexuales
5.
J Chromatogr A ; 1662: 462724, 2022 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-34902716

RESUMEN

Comonomer content distribution (CCD), also commonly known as chemical composition distribution (CCD) and short chain branching distribution (SCBD), describes the variation of short chain branching composition between individual polymer chains in polyolefin materials. It is of particular importance for controlling polyolefin performance. Crystallization-based separation methods have evolved over the past four decades aiming at resolution, speed, precision, and accuracy. Two of the commonly used techniques are Crystallization Elution Fractionation (CEF) and Temperature Rising Elution Fractionation (TREF), where polymer chains are physically separated along the column or on the surface of the support based on their crystallinity, respectively. CEF analysis takes much less time than TREF. There is a critical need for precise temperature calibrations for data repeatability. This report demonstrates a novel CEF methodology using a two-point technique to consistently and conveniently calibrate the comonomer composition and column temperature. This column temperature calibration methodology was adopted in a study by tracking the reproducibility over a period of 8 years, using multiple instruments located in different laboratories and in different geographies. The results exhibited superior repeatability, with less than 0.3% of the relative error calculated from 3000 data points of the eluting peak temperature, thus demonstrating this as a robust method for industrial labs that require good quality controls.


Asunto(s)
Fraccionamiento Químico , Polietileno , Calibración , Cristalización , Reproducibilidad de los Resultados
6.
Surg Obes Relat Dis ; 17(1): 90-95, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33032917

RESUMEN

BACKGROUND: Early postoperative ambulation reduces length of stay and prevents postoperative complications after bariatric surgery. Rarely is postoperative inpatient activity objectively measured despite readily available commercial activity trackers. OBJECTIVES: Evaluate the impact of using activity trackers to record number of inpatient steps taken after bariatric surgery and assess how patient characteristics may affect the number of steps recorded. SETTING: University Hospital, United States. METHODS: Using an activity tracker, the number of steps taken during the postoperative hospital stay was recorded for 235 patients undergoing either laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy. Patients were randomly assigned to either being informed about the devices' ability to record the number of steps taken or blinded to the purpose of the devices. Descriptive statistics were used to summarize study sample, a t test was used to compare number of steps recorded between groups, and a multivariate regression model was used to examine the effect of age, sex, preoperative body mass index (BMI), types of surgery, and length of stay on number of steps recorded. RESULTS: One hundred twenty-five patients (52.8%) were randomized to the blinded group while 111 (47.2%) were informed that the device would record the number of steps taken. There were no differences in the number of steps recorded between the 2 groups. Patients with prolonged length of stay recorded lower numbers of steps taken on postoperative day 0. Increasing age was seen to reduce the number of steps recorded on postoperative day number 1. There were no significant differences in number of steps recorded based on sex, preoperative BMI, or surgery type. CONCLUSION: The present study found that knowledge of an activity tracker being used did not affect the patient's activity level as measured by steps recorded. Increasing age correlated to reduced number of steps recorded on postoperative day 1 after bariatric surgery.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Monitores de Ejercicio , Gastrectomía , Humanos , Pacientes Internos , Tiempo de Internación , Obesidad Mórbida/cirugía , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/cirugía , Estudios Retrospectivos , Resultado del Tratamiento
7.
Am Surg ; 86(12): 1666-1671, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32776782

RESUMEN

BACKGROUND: Intraoperative radiation therapy (IORT) is an alternate accelerated form of radiation following breast-conserving surgery (BCS). Lack of data regarding long-term outcomes has limited adoption. We report our experience with IORT in patients undergoing BCS versus whole breast radiation therapy (WBRT). METHODS: Retrospective review of patients undergoing BCS with IORT versus WBRT (2012-2017). Inclusion: low grade, T1-2N0M0, estrogen receptor/progesterone receptor positive, and Her2-negative infiltrating ductal carcinomas. IORT was delivered as a single fraction of radiation (20 Gy) intraoperatively. Outcomes were compared using Fisher's test for discrete variables or Wilcoxon signed-rank test for continuous variables. Kaplan-Meier method was used to estimate disease-free survival (DFS). RESULTS: Fifty-one patients (44%) received IORT, and 66 (56%) received WBRT. There was no difference in age, tumor size, receptor status, or in-breast recurrence (1.9% vs 0%, all P > .05). Length of follow-up was longer in the WBRT group due to time to inception of IORT (mean ± SD: 44 ± 8.1 vs 73 ± 13 months, P < .001). There was no difference in DFS between the 2 groups (HR 2.5; P = .44). IORT patients experienced delay to BCS (mean ± SD: 38 ± 12.7 vs 27 ± 12.2 days, P < .001) likely due to coordination of care. Analysis demonstrated IORT patients would have traveled a mean distance of 20 miles to the closest WBRT center (range 1-70, miles) for a mean travel time of 31 minutes (range 4-90, minutes) per WBRT treatment. DISCUSSION: IORT produces noninferior oncologic outcomes and decreased skin toxicity compared with WBRT. It can be convenient for patients in rural regions with limited health care access.


Asunto(s)
Neoplasias de la Mama/radioterapia , Neoplasias de la Mama/cirugía , Adulto , Región de los Apalaches , Fraccionamiento de la Dosis de Radiación , Femenino , Humanos , Cuidados Intraoperatorios , Mastectomía Segmentaria , Radioterapia Adyuvante , Estudios Retrospectivos , Población Rural
8.
Disaster Med Public Health Prep ; 14(6): 687-690, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-31937386

RESUMEN

Low-frequency, high-acuity emergency events can and do occur within health care settings. Having a strong sense of daily situational and operational awareness is the first step in responding to any emergency event. To maintain high reliability, hospital leaders and staff must understand the full impact to the organization as the emergency event evolves. The Medical University of South Carolina health system has implemented the common practice of a daily operations safety briefing, called the Daily Check-In, to communicate any issues that could impact the operational ability of the hospitals within the enterprise, or any other associated resources during a disaster or emergency. Throughout various emergency events, including extreme weather, the Daily Check-In has evolved as a standard process for use during emergencies that is open to all staff and uses highly reliable systems.


Asunto(s)
Planificación en Desastres , Desastres , Urgencias Médicas , Hospitales , Humanos , Reproducibilidad de los Resultados
9.
SVOA Dent ; 1(1): 1-8, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-35199104

RESUMEN

There is a need to increase oral health knowledge, attitudes and behaviors in children to improve oral health. This research involves peer-assisted learning to determine if high school students can influence rural middle school students' oral health. The study sample consisted of middle school students. After completing pre-test, they were assigned to receive 1) didactic peer-assisted learning with professionally supervised and educated high school students (members of an after-school pipeline program for science, technology, engineering, mathematics, and health science); or, 2) teacher provided handouts/activity sheets. Both groups then completed a post test. The results of the Mann-Whitney U Tests showed that brushing and flossing failed to reach significant improvements between the pre-test and post-test for the handouts/activity sheets group (brushing, P=0.391; flossing, P=0.459). There was improvement within that group for oral health knowledge (P<.001). Brushing, flossing and oral health knowledge failed to reach significant improvement between the pre-test and post-test for the peer-assisted learning group (brushing, P=0.760; flossing, P=0.707; oral health knowledge, P= 0.154). In terms of oral health knowledge, there was no difference between the scores of the two groups on the pre-test (P-value = 0.980) nor on the post-test (P-value= 0.237). Near-peer assisted learning for oral hygiene knowledge, attitudes, and behaviors had similar outcomes as teacher provided handouts and activity sheets in a middle school setting.

10.
Am Surg ; 85(8): 830-833, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31560302

RESUMEN

Although gallbladder disease (GBD) is more common in females, we have noticed a trend toward more complicated cases in male patients. We reviewed all cholecystectomies performed at our institution over the last five years. After eliminating cases with confounding variables, we identified 1529 records. Charts were reviewed for age, gender, BMI, procedure performed, operative time, length of stay, and preoperative diagnosis. Descriptive and inferential statistical analyses were conducted along with linear regression. There were 1444 laparoscopic, 64 laparoscopic converted to open, and 21 primary open cases. Patients were 1008 (66%) females and 521 (34%) males. Average operative time was 89.8 minutes. Cholecystectomy averaged 17.7 minutes longer in males (P = 0.0046). Two per cent of female patients and 7.9 per cent male patient converted to open. Males were more likely to have complicated GBD, whereas women had uncomplicated disease. Average age was 51.9 years for males versus 42.7 years for females. Age, gender, BMI, length of stay, and preoperative diagnosis were all independently significant in predicting operative time. In our study, women presented with uncomplicated GBD, whereas men presented with complicated GBD. This suggests that male patients present at a later stage of disease.


Asunto(s)
Colecistectomía , Enfermedades de la Vesícula Biliar/cirugía , Adulto , Factores de Edad , Índice de Masa Corporal , Colecistectomía Laparoscópica , Femenino , Enfermedades de la Vesícula Biliar/complicaciones , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Tempo Operativo , Factores Sexuales
15.
Stem Cells ; 25(12): 3121-32, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17717065

RESUMEN

Mcm2 is a component of the DNA replication licensing complex that marks DNA replication origins during G1 of the cell cycle for use in the subsequent S-phase. It is expressed in stem/progenitor cells in a variety of regenerative tissues in mammals. Here, we have used the Mcm2 gene to develop a transgenic mouse in which somatic stem/progenitor cells can be genetically modified in the adult. In these mice, a tamoxifen-inducible form of Cre recombinase is integrated 3' to the Mcm2 coding sequence and expressed via an internal ribosome entry site (IRES). Heterozygous Mcm2(IRES-CreERT2/wild-type (wt)) mice are phenotypically indistinguishable from wild-type at least through 1 year of age. In bigenic Mcm2(IRES-CreERT2/wt); Z/EG reporter mice, tamoxifen-dependent enhanced green fluorescence protein expression is inducible in a wide variety of somatic stem cells and their progeny. However, in Mcm2(IRES-CreERT2/IRES-CreERT2) homozygous embryos or mouse embryonic fibroblasts, Mcm2 is reduced to approximately one-third of wild-type levels. Despite the fact that these mice develop normally and are asymptomatic as young adults, life span is greatly reduced, with most surviving to only approximately 10-12 weeks of age. They demonstrate severe deficiencies in the proliferative cell compartments of a variety of tissues, including the subventricular zone of the brain, muscle, and intestinal crypts. However, the immediate cause of death in most of these animals is cancer, where the majority develop lymphomas. These studies directly demonstrate that deficiencies in the function of the core DNA replication machinery that are compatible with development and survival nonetheless result in a chronic phenotype leading to stem cell deficiency in multiple tissues and cancer. Disclosure of potential conflicts of interest is found at the end of this article.


Asunto(s)
Proteínas de Ciclo Celular/genética , Regulación Neoplásica de la Expresión Génica , Linfoma/genética , Linfoma/patología , Proteínas Nucleares/deficiencia , Proteínas Nucleares/genética , Células Madre/metabolismo , Células Madre/patología , Animales , Secuencia de Bases , Recuento de Células , Proteínas de Ciclo Celular/antagonistas & inhibidores , Proteínas de Ciclo Celular/biosíntesis , Femenino , Regulación Neoplásica de la Expresión Génica/fisiología , Integrasas/genética , Linfoma/metabolismo , Linfoma/mortalidad , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Componente 2 del Complejo de Mantenimiento de Minicromosoma , Datos de Secuencia Molecular , Mutagénesis Insercional , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/biosíntesis , Ribosomas/genética , Ribosomas/metabolismo , Células Madre/fisiología , Análisis de Supervivencia
16.
Stem Cells ; 25(1): 132-8, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17008428

RESUMEN

Previous studies have demonstrated expression of the minichromosome maintenance protein Mcm2 in cells that remain competent to divide, including stem/progenitor cells of the subventricular zone (SVZ) within the brain. Here, a transgenic mouse line in which the Mcm2 gene drives expression of enhanced green fluorescent protein (EGFP) was constructed by insertion of an internal ribosomal entry site (IRES)-EGFP cassette into the last exon of the gene, 3' to the stop codon. In these mice, expression of EGFP is observed in the SVZ and several other tissues with high proliferative activity, including the spleen, intestine, hair follicles, and bone marrow. These observations suggest that EGFP fluorescence in this mouse line provides an index of the proliferative capacity of different tissues. Immunohistological analysis demonstrates a direct concordance between expression of EGFP and Mcm2, consistent with a transcriptional level downregulation of Mcm2 expression in postmitotic cells. To test the utility of EGFP expression for recovery of live cells retaining the capacity to divide, EGFP-expressing and -nonexpressing cells from bone marrow and brain were isolated from an adult Mcm2(IRES-EGFP) mouse by fluorescence-activated cell sorting and assayed for clonal growth. The EGFP-positive fraction contained the entire clonogenic population of the bone marrow and greater than 90% of neurosphere-forming cells from the brain. Brain-derived clonogenic cells were shown to remain competent to differentiate towards all three neural lineages. These studies demonstrate that the Mcm2(IRES-EGFP) transgenic line constructed here can be used for recovery of proliferation competent cells from different tissue types.


Asunto(s)
Proteínas Fluorescentes Verdes/genética , Proteínas Nucleares/genética , Células Madre/fisiología , Animales , Blastocisto/citología , Blastocisto/fisiología , Exones , Genes Reporteros , Genoma , Proteínas Fluorescentes Verdes/análisis , Ratones , Ratones Transgénicos , Componente 2 del Complejo de Mantenimiento de Minicromosoma , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , Transfección
17.
Aging Cell ; 3(6): 391-7, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15569356

RESUMEN

Genomic instability within somatic stem cells may lead to the accumulation of mutations and contribute to cancer or other age-related phenotypes. However, determining the frequency of mutations that differ among individual stem cells is difficult from whole tissue samples because each event is diluted in the total population of both stem cells and differentiated tissue. Here the ability to expand neural stem/progenitor cells clonally permitted measurement of genomic alterations derived from a single initial cell. C57Bl/6 x DBA/2 hybrid mice were used and PCR analysis with strain-specific primers was performed to detect loss of heterozygosity on nine different chromosomes for each neurosphere. The frequency with which changes occurred in neurospheres derived from 2-month- and 2-year-old mice was compared. In 15 neurospheres derived from young animals both parental chromosomes were present for all nine chromosome pairs. In contrast, 16/17 neurospheres from old animals demonstrated loss of heterozygosity (LOH) on one or more chromosomes and seven exhibited a complete deletion of at least one chromosomal region. For chromosomes 9 and 19 there is a significant bias in the allele that is lost where in each case the C57Bl/6 allele is retained in 6/6 neurospheres exhibiting LOH. These data suggest that aging leads to a substantial mutational load within the neural stem cell compartment which can be expected to affect the normal function of these cells. Furthermore, the retention of specific alleles for chromosomes 9 and 19 suggests that a subset of mutational events lead to an allele-specific survival advantage within the neural stem cell compartment.


Asunto(s)
Senescencia Celular/fisiología , Neuronas/fisiología , Células Madre/fisiología , Alelos , Animales , Senescencia Celular/genética , Cromosomas/genética , Pérdida de Heterocigocidad/genética , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Mutación , Neuronas/citología , Fenotipo , Reacción en Cadena de la Polimerasa/métodos , Selección Genética
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