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In-situ measurements of soil water content provide important constraints on local/global hydrology. We demonstrate that the attenuation of the underground flux of cosmic-ray electromagnetic (EM) particles can be used to monitor the variation of soil water content after rainfalls. We developed a detection system that preferably selects EM particles by considering the coincidence of distant plastic scintillators. The calibration test beneath the water pool revealed that the count rate decreased by 0.6-0.7% with a 1 cm increase in the water level. The field measurement performed in the horizontal tunnel showed that the count rate dropped according to 48-h precipitation, after correcting the effects originating from atmospheric and water vapour pressures. These characteristics were confirmed using dedicated Monte Carlo simulations. This new method is called cosmic electromagnetic particle (CEMP) radiography.
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Characterizing the size and settling velocity of pyroclastic fragments injected into the atmosphere during volcanic eruptions (i.e., tephra) is crucial to the forecasting of plume and cloud dispersal. Optical disdrometers have been integrated into volcano monitoring networks worldwide in order to best constrain these parameters in real time. Nonetheless, their accuracy during tephra fallout still needs to be assessed. A significant complication is the occurrence of particle aggregates that modify size and velocity distributions of falling tephra. We made the first use of the Thies Clima Laser Precipitation Monitor (LPM) for tephra-fallout detection at Sakurajima volcano (Japan), which is characterized by a lower size detection window with respect to more commonly used disdrometers (e.g., Parsivel2) and can more easily distinguish different falling objects. For the first time, individual particles have been distinguished from most aggregates based on disdrometer data, with the potential to provide useful grain-size information in real time. In case of negligible aggregation, LPM and collected sample-based estimates are in agreement for both grain-size and sedimentation rate. In case of significant aggregation, particle shape analyses and a dedicated drag equation are used to filter out aggregates from LPM data that also provide good agreement with collected tephra samples.
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Desastres , Erupciones Volcánicas , Atmósfera , JapónRESUMEN
Aggregation of volcanic ash is known to significantly impact sedimentation from volcanic plumes. The study of particle aggregates during tephra fallout is crucial to increase our understanding of both ash aggregation and sedimentation. In this work, we describe key features of ash aggregates and ash sedimentation associated with eleven Vulcanian explosions at Sakurajima Volcano (Japan) based on state-of-the-art sampling techniques. We identified five types of aggregates of both Particle Cluster (PC) and Accretionary Pellet (AP) categories. In particular, we found that PCs and the first and third type of APs can coexist within the same eruption in rainy conditions. We also found that the aerodynamic properties of aggregates (e.g., terminal velocity and density) depend on their type. In addition, grainsize analysis revealed that characteristics of the grainsize distributions (GSDs) of tephra samples correlate with the typology of the aggregates identified. In fact, bimodal GSDs correlate with the presence of cored clusters (PC3) and liquid pellets (AP3), while unimodal GSDs correlate either with the occurrence of ash clusters (PC1) or with the large particles (coarse ash) coated by fine ash (PC2).
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BACKGROUND: Periodic point prevalence surveys (PPSs) provide a method for assessing changes in healthcare-associated infections (HAIs) and antimicrobial use over time. Following the introduction of an antimicrobial stewardship programme at Nagoya University Hospital (Aichi, Japan) a five-year PPS study was performed to highlight any epidemiological changes. METHODS: One-day PPSs were performed annually in July at Nagoya University Hospital. Data on patient characteristics, medical devices, active HAIs and antimicrobial use were collected using a standard data-collection form. RESULTS: A total of 4339 patients were included. Over the five-year study period the median patient age was 62 years, median duration of hospital admission was nine days, 9% of patients had an HAI and 35.2% received at least one antimicrobial. Overall there were 406 HAIs (95% confidence interval, 369-447) with surgical site infection, pneumonia and febrile neutropenia occurring most frequently. Enterobacterales were the most common pathogens (N = 78, 28.6%) and 32.1% were third-generation cephalosporin-resistant. Meropenem was the most frequently prescribed antimicrobial for HAIs. Surgical antimicrobial prophylaxis changed drastically, with shorter durations and a marked reduction in oral cephalosporin use. However, antimicrobials for medical prophylaxis gradually increased. CONCLUSIONS: This five-year PPS study shows consistent data for patient background, HAIs and causative pathogens and highlights changes in antimicrobial use during the era of the National Action Plan on Antimicrobial Resistance. To describe the epidemiology of Japanese hospitals by PPS, multicentre PPSs including in community hospitals should be performed annually.
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BACKGROUND: Hospital outbreaks of antimicrobial-resistant (AMR) bacteria should be detected and controlled as early as possible. AIM: To develop a framework for automatic detection of AMR outbreaks in hospitals. METHODS: Japan Nosocomial Infections Surveillance (JANIS) is one of the largest national AMR surveillance systems in the world. For this study, all bacterial data in the JANIS database were extracted between 2011 and 2016. WHONET, a free software for the management of microbiology data, and SaTScan, a free cluster detection tool embedded in WHONET, were used to analyse 2015-2016 data of eligible hospitals. Manual evaluation and validation of 10 representative hospitals around Japan were then performed using 2011-2016 data. FINDINGS: Data from 1031 hospitals were studied; mid-sized (200-499 beds) hospitals accounted for 60%, followed by large hospitals (≥500 beds; 24%) and small hospitals (<200 beds; 16%). More clusters were detected in large hospitals. Most of the clusters included five or fewer patients. From the in-depth analysis of 10 hospitals, â¼80% of the detected clusters were unrecognized by infection control staff because the bacterial species involved were not included in the priority pathogen list for routine surveillance. In two hospitals, clusters of more susceptible isolates were detected before outbreaks of more resistant pathogens. CONCLUSION: WHONET-SaTScan can automatically detect clusters of epidemiologically related patients based on isolate resistance profiles beyond lists of high-priority AMR pathogens. If clusters of more susceptible isolates can be detected, it may allow early intervention in infection control practices before outbreaks of more resistant pathogens occur.
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Automatización de Laboratorios/métodos , Infecciones Bacterianas/epidemiología , Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Farmacorresistencia Bacteriana , Monitoreo Epidemiológico , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/microbiología , Análisis por Conglomerados , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/microbiología , Humanos , Japón , Programas InformáticosRESUMEN
BACKGROUND: The Japanese government adopted a national action plan on antimicrobial resistance, which aims to reduce drug-resistant pathogens and antimicrobial use. A point-prevalence survey (PPS) is a useful surveillance method to gain information about hospital epidemiology; however, no multi-centre PPS has previously been performed in Japan. AIM: To investigate general information about hospital epidemiology, healthcare-associated infections (HCAIs), and antimicrobial use in multiple Japanese university hospitals. METHODS: In July 2016, a multi-centre PPS was conducted using a standardized protocol at four university hospitals in Japan. FINDINGS: A total of 3199 patients were included. Median age and duration of hospital stay were 64 years and 10 days, respectively. A total of 246 (7.7%; 95% confidence interval (CI): 6.8-8.7) patients had 256 active HCAIs, and 933 (29.2%; 95% CI: 27.6-30.8) patients received 1318 antimicrobials. Pneumonia and gastrointestinal system infection were the most common HCAIs (N = 42, 16.4%), and Enterobacteriaceae (N = 49, 30.8%) were the predominant causative organisms. Carbapenems (N = 52, 17.8%), anti-MRSA medications, and cephems with antipseudomonal activity were the most frequently prescribed antimicrobials for HCAIs. As surgical prophylaxis, 46 of 278 antimicrobials (16.5%) were administered orally. Proportions of HCAI and antimicrobial use in each hospital ranged from 4.8% to 9.5% and 19.3%-35.0%, respectively. CONCLUSION: This multi-centre PPS recorded detailed HCAI data and distinct antimicrobial use in Japanese university hospitals. Further surveillance is necessary to reduce HCAIs and formulate feasible plans to achieve the national action plan on antimicrobial resistance.
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Antibacterianos/uso terapéutico , Infección Hospitalaria/epidemiología , Utilización de Medicamentos , Infecciones por Enterobacteriaceae/epidemiología , Enterobacteriaceae/aislamiento & purificación , Hospitales Universitarios , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Japón , Masculino , Persona de Mediana Edad , Prevalencia , Encuestas y Cuestionarios , Adulto JovenRESUMEN
A 59-year-old male patient presented with left chest discomfort on admission. His medical history included encephalitis in childhood and his smoking history was 20 cigarettes per day for 40 years. A physical examination showed an anemic and edematous face with weak respiratory sounds in the left lung. The patient had elevated calcium levels and decreased hemoglobin and potassium. His parathyroid hormone-related protein level was elevated. Thoracic radiography showed cardiomegaly and computed tomography revealed a left lung mass with invasion of the heart and pleural effusion. Magnetic resonance imaging showed endocardial invasion of the tumor mass. Gallium-68 imaging revealed positive accumulation in the region surrounding the heart. No diagnoses were possible upon frequent cytology of his sputum and pleural effusion. The patient died from congestive heart failure with anoxia 38 days after admission. An autopsy revealed tumoral mass occlusion in the left main bronchus and tumoral invasion of the left atrium, left ventricle, and aorta.
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Opposite undamaged nucleotide T, DNA polymerase ι (Polι) preferentially incorporates G rather than A, violating the Watson-Crick rule. Although the actual biological role of Polι remains enigmatic, we have identified its coding gene as a candidate for pulmonary adenoma resistance 2 (Par2), a mouse quantitative trait locus modulating chemically induced lung tumor susceptibility. Notably, the most tumor-sensitive Par2 allele possessed by the 129X1/SvJ mouse is associated with a loss-of-function mutation in Polι. To determine whether the nonfunctional Polι is responsible for the 129X1/SvJ-specific Par2 phenotype, we knocked out Polι in a C57BL/6J mouse carrying a less tumor-sensitive Par2 allele. Disruption of the C57BL/6J Polι conferred 129X1/SvJ-like sensitivity on the C57BL/6J Par2 locus and increased the in vivo mutation frequency in the lung, providing definitive proof that Polι causes the Par2 effect and inhibits tumorigenesis and mutagenesis, despite its extreme replication infidelity.
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Carcinogénesis , ADN Polimerasa Dirigida por ADN/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Mutagénesis , Alelos , Animales , Secuencia de Bases , Línea Celular , ADN Polimerasa Dirigida por ADN/deficiencia , ADN Polimerasa Dirigida por ADN/genética , Femenino , Técnicas de Inactivación de Genes , Humanos , Neoplasias Pulmonares/enzimología , Masculino , Ratones , Ratones Endogámicos C57BL , Sitios de Carácter Cuantitativo/genética , ADN Polimerasa iotaRESUMEN
A 94-year-old female patient presented with anorexia and left axillar lymphadenopathy on admission. Her past history was angina pectoris at 83 years of age and total gastrectomy due to gastric cancer at 87 years. The family history revealed that her son had had a malignant lymphoma, the histopathological diagnosis of which was diffuse large B-cell lymphoma. A physical examination showed both cervical, axillar, and inguinal lymphadenopathy without tenderness. She had elevated lactate dehydrogenase, ferritin, and soluble interleukin-2 receptor (sIL-2R). Whole-body computed tomography confirmed the cervical, axillary, and inguinal lymphadenopathy. Gallium-68 imaging revealed positive accumulation in these superficial lymph nodes. A right inguinal lymph node biopsy showed features of Epstein-Barr virus-associated lymphoproliferative disorder. Immunohistological studies on this lymph node biopsy showed CD20-positive large cells, CD3-positive small cells, and CD30-partly-positive large cells. In situ hybridization showed Epstein-Barr virus-positive, LMP-partly-positive, and EBNA2-negative cells. She refused chemotherapy as her son had died from hematemesis during chemotherapy. She received intravenous hyperalimentation for 1 month after admission. No palpable lymph nodes were identified by physical examination or computed tomography 3 months after admission, and regression of lactate dehydrogenase, ferritin, and sIL-2R was observed. She recovered from anorexia and was discharged. She died from pneumonia 10 months later after initial symptoms of anorexia. The autopsy showed no superficial lymphadenopathy.
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Plasmid-mediated AmpC ß-lactamase-producing Escherichia coli (AmpC-E) bacteraemia was characterized by comparison with bacteraemia caused by extended-spectrum ß-lactamase (ESBL)-producing E. coli (ESBL-E) and non-resistant E. coli (NR-E) in the era of the worldwide spread of the CTX-M-15-producing O25b-ST131-B2 clone. Of 706 bloodstream E. coli isolates collected between 2005 and 2010 in three Japanese university hospitals, 111 ESBL screening-positive isolates were analysed for AmpC and ESBL genes by PCR. A case-control study was performed in which the cases consisted of all of the patients with AmpC-E bacteraemia. Phylogenetic groups, sequence types and O25b serotype were determined. Twenty-seven AmpC-E isolates (26 of which were of the CMY-2 type) were identified, and 54 ESBL-E and 54 NR-E isolates were selected for the controls. Nineteen AmpC-E isolates were also positive for ESBL. CTX-M-14 was the most prevalent ESBL type among both the AmpC-E and ESBL-E isolates. The O25b-ST131-B2 clone was the most prevalent among the ESBL-E isolates (26%) and the second most prevalent among the NR-E isolates (13%), but only one O25b-ST131-B2 clone was found among the AmpC-E isolates. Twenty-three different sequence types were identified among the AmpC-E isolates. When compared with bacteraemia with ESBL-E, previous isolation of multidrug-resistant bacteria and intravascular catheterization were independently associated with a lower risk for AmpC-E. When compared with NR-E bacteraemia, prior use of antibiotics was the only significant risk factor for AmpC-E. Unlike the spread of the O25b-ST131-B2 clone between ESBL-E and NR-E, the AmpC-E isolates were not dominated by any specific clone.
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Bacteriemia/microbiología , Bacteriemia/patología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Escherichia coli/clasificación , Escherichia coli/enzimología , beta-Lactamasas/metabolismo , Adulto , Anciano , Bacteriemia/epidemiología , Estudios de Casos y Controles , ADN Bacteriano/genética , Escherichia coli/genética , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/epidemiología , Femenino , Genotipo , Hospitales Universitarios , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Tipificación Molecular , Filogenia , Plásmidos , Reacción en Cadena de la Polimerasa , Factores de Riesgo , Análisis de Secuencia de ADN , beta-Lactamasas/genéticaRESUMEN
OBJECTIVES: We investigated the correlation between Japanese apricot (JA) intake and Helicobacter pylori-related chronic atrophic gastritis (CAG). METHODS: A questionnaire was administered and serum anti-H. pylori IgG antibodies measured in 1358 asymptomatic adults. The subjects were divided into high-intake and low-intake groups. Histological and serological evaluation of H. pylori-related CAG was performed in 68 non-elderly volunteers. RESULTS: The H. pylori-negative rate did not differ significantly between the high-intake and low-intake groups. Mean antibody titers were lower in the high-intake group, but the difference was not significant. There was no significant difference in the rate of H. pylori infection on the basis of JA intake when subjects were stratified by age. Among H. pylori-positive non-elderly subjects, antibody titers were significantly lower in the high-intake group (P=0.041). Endoscopic tissue biopsy from the 68 volunteers showed less H. pylori bacterial load and mononuclear infiltration irrespective of gastric site in the high-intake group. In the high-intake group, antral neutrophil infiltration was significantly less pronounced and corporal atrophy was less extensive. Serological evaluation using serum PG levels also confirmed these histopathological data. CONCLUSIONS: Our findings strongly indicate a preventive effect of JA intake on CAG by inhibiting H. pylori infection and reducing active mucosal inflammation.
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Dieta , Gastritis/prevención & control , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/efectos de los fármacos , Preparaciones de Plantas/uso terapéutico , Prunus , Estómago/efectos de los fármacos , Adulto , Anciano , Anticuerpos/sangre , Enfermedad Crónica , Relación Dosis-Respuesta a Droga , Femenino , Frutas , Gastritis/inmunología , Gastritis/microbiología , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/inmunología , Humanos , Masculino , Persona de Mediana Edad , Neutrófilos/efectos de los fármacos , Pepsinógeno C/sangre , Preparaciones de Plantas/farmacología , Prevalencia , Estómago/inmunología , Estómago/microbiología , Encuestas y CuestionariosAsunto(s)
Electrocoagulación/instrumentación , Mucosa Gástrica/cirugía , Hemorragia Gastrointestinal/cirugía , Gastroscopios , Hemostasis Endoscópica/instrumentación , Complicaciones Intraoperatorias/cirugía , Neoplasias Gástricas/cirugía , Diseño de Equipo , Humanos , Irrigación Terapéutica/instrumentaciónRESUMEN
BACKGROUND AND STUDY AIM: We have previously reported that gastric ulcers artificially created by endoscopic submucosal dissection (ESD) would heal within 8 weeks regardless of size and location. The details of the healing process remain unclear, and we aimed to clarify the mechanism by histopathological investigation. PATIENTS AND METHODS: 21 post-ESD ulcers were examined histopathologically, using surgically resected specimens from patients who had subsequently undergone gastrectomy due to submucosal invasion and/or lymphovascular infiltration by the tumor. The grade of ulcer, appearance of regenerative mucosa, scar formation, and extent of fibrosis were evaluated. RESULTS: Fibrosis and wall thickening were observed from 2 weeks after ESD, but regenerative mucosa was not observed until 5 weeks. Among 12 patients who underwent gastrectomy later than 8 weeks after ESD, a mucosal defect was still observed in two patients. In these two patients the lesion was associated with severe fibrosis due to previous peptic ulcer or submucosal invasion by the lesion. CONCLUSION: Size reduction in these ulcers occurs by contraction in the early phase, then regenerative mucosa covers the remaining mucosal defect within 8 weeks. If there is fibrosis under the lesion before ESD, there is a possibility that the artificially created ulcer will not heal within 8 weeks.
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Endoscopía Gastrointestinal/métodos , Mucosa Gástrica/cirugía , Úlcera Gástrica/patología , Anciano , Femenino , Estudios de Seguimiento , Mucosa Gástrica/patología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Úlcera Gástrica/cirugía , Resultado del Tratamiento , Cicatrización de HeridasRESUMEN
Most smokers do not plan to quit in the next 6 months. The authors previously demonstrated that percentile schedules shape lower breath carbon monoxide (BCO) levels in smokers trying to quit (R. J. Lamb, A. R. Morral, K. C. Kirby, M. Y. Iguchi, & G. Galbicka, 2004). In that study, the authors set reinforcement criteria based on the 9 most recent samples. In this study, the authors examined whether a more responsive procedure using the 4 most recent samples is more effective in smokers not trying to quit. Following institution of the contingencies in both groups, BCO levels were substantially reduced, and readiness to quit and cessation self-efficacy increased. However, more individuals in the 4-sample window group achieved a BCO level below 4 ppm, indicating recent abstinence. These individuals did so more rapidly and for a greater number of visits.
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Cese del Hábito de Fumar , Fumar/psicología , Fumar/terapia , Adolescente , Adulto , Monóxido de Carbono/sangre , Educación , Empleo , Femenino , Humanos , Renta , Masculino , Matrimonio , Cooperación del Paciente , Factores SocioeconómicosRESUMEN
Behavioral interventions that provide incentives contingent upon abstinence are effective addiction treatments. Nevertheless, these treatments often fail for individuals whose recent behaviors are very different from those reinforced. These hard-to-treat individuals may require shaping to achieve abstinence. We used percentile schedules to shape smokers' delivery of breath samples indicative of recent smoking abstinence (breath carbon monoxide (BCO) <4 ppm). Percentile schedules deliver incentives to current behaviors proximal to the target. Participants (N = 102) were assigned to treatments delivering incentives for breath COs at or below the 10th, 30th, 50th, or 70th percentile of recent breath COs. Each condition effectively ensured contact with available contingencies, and resulted in BCO <4 ppm in >90% of the 30th, 50th and 70th percentile groups versus 63% in the 10th percentile. The 30th, 50th and 70th percentiles were especially effective in a sub-sample of hard-to-treat participants who did not deliver a breath CO <4 ppm during an initial abstinence test or during a nine-visit baseline period, suggesting the value of shaping for this important sub-sample.
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Esquema de Refuerzo , Cese del Hábito de Fumar/métodos , Fumar/terapia , Adulto , Anciano , Análisis de Varianza , Citas y Horarios , Terapia Conductista/métodos , Pruebas Respiratorias/métodos , Distribución de Chi-Cuadrado , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fumar/psicología , Cese del Hábito de Fumar/psicologíaRESUMEN
BACKGROUND AND STUDY AIMS: One of the major complications of endoscopic mucosal resection (EMR) for gastrointestinal tumors is perforation, and the most effective way of preventing perforation is to elevate the lesion sufficiently by endoscopic injection of fluid into the submucosa. MATERIALS AND METHODS: In order to compare the lesion-lifting properties of several different solutions, 1 ml of each of the following solutions was injected into the submucosa of the resected porcine stomach: normal saline, 3.75 % NaCl, 20 % dextrose water, 10 % glycerin with 0.9 % NaCl plus 5 % fructose, and two sodium hyaluronate (SH) solutions. RESULTS: Significantly higher initial elevation was produced by both SH solutions, and it remained higher than that achieved by the other solutions at all times. Hypertonic solutions, especially 10 % glycerin with 0.9 % NaCl plus 5 % fructose, tended to produce and maintain greater mucosal elevation than normal saline, but the difference was not significant. CONCLUSIONS: SH solutions were the most suitable ones for producing and maintaining long-term mucosal elevation, while the superiority of hypertonic solutions over normal saline was not clearly demonstrated.
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Mucosa Gástrica/cirugía , Gastroscopía , Soluciones/administración & dosificación , Animales , Mucosa Gástrica/patología , Gastroscopía/métodos , Glucosa , Glicerol , Ácido Hialurónico , Técnicas In Vitro , Inyecciones , Cloruro de Sodio , PorcinosRESUMEN
BACKGROUND AND STUDY AIMS: Sodium hyaluronate (SH) is a promising submucosal injection solution during endoscopic mucosal resection, but its high cost is an obstacle to more widespread use. The aim of this study was to identify an appropriate low-cost SH solution by varying the molecular weight of SH and mixing various solutions with it. MATERIALS AND METHODS: The viscoelasticity of various SH solutions was first measured. The concentrations of two 1 % SH preparations with different molecular weights (800 kDa and 1900 kDa) were adjusted to 0.5 %, 0.25 %, and 0.125 %, using 0.9 %/3.75 % normal saline (NS), 5 %/20 % dextrose water (DW), and a glycerin solution (Glyceol): 10 % glycerin with 0.9 % normal saline plus 5 % fructose. The ability of these SH solutions to create submucosal fluid cushions (SFCs) was then investigated in the stomachs of two live minipigs. RESULTS: The 0.25 % 1900 kDa SH/NS solution and the 0.125 % 1900 kDa SH/20 % DW solution created a similar viscoelasticity to that of the 0.5 % 800 kDa SH/NS solution. The ability of these solutions to create SFCs was also similar. In addition, the 0.125 % 1900 kDa SH/Glyceol solution created similar SFCs, with a synergistic effect of increased viscoelasticity and the hypertonic nature of glycerin. CONCLUSIONS: A mixture of higher molecular weight sodium hyaluronate with a sugar solution (particularly 20 % dextrose), with or without glycerin, should be regarded as a cost-effective option for creating SFCs instead of the conventional SH solution made with the same amount of a 1 % 800 kDa SH preparation and normal saline.
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Mucosa Gástrica/cirugía , Gastroscopía , Ácido Hialurónico/administración & dosificación , Inyecciones , Animales , Mucosa Gástrica/patología , Gastroscopía/métodos , Glucosa , Glicerol , Peso Molecular , Cloruro de Sodio , Soluciones/administración & dosificación , Porcinos , Porcinos Enanos , ViscosidadAsunto(s)
Angiodisplasia/complicaciones , Enfermedades del Colon/complicaciones , Pólipos del Colon/complicaciones , Hemorragia Gastrointestinal/etiología , Angiodisplasia/patología , Colon/patología , Colon/cirugía , Enfermedades del Colon/patología , Pólipos del Colon/patología , Colonoscopía , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Contingency management interventions effectively reduce or eliminate some individuals' problem substance use. Typically, those who do not benefit never experience the reward or planned contingency available through the intervention because they never produce the behavior (often abstinence) on which the reward is contingent. With two analog studies, we examine whether the effectiveness contingency management interventions improves when contingencies are arranged in ways that improve the likelihood of all participants experiencing the available reward. Participants were smokers not planning to quit. In Study 1, smokers were paid 0, 1, 3, 10, or 30 dollars each day for 5 days for delivery of breath carbon monoxide (CO) levels either < or =4 ppm or below half the median of their baseline levels. Higher payment amounts and the easier target criterion resulted in a higher likelihood of participants meeting criterion. Once participants met the 4 ppm criterion, however, they often maintained this behavior even in the absence of payments for reduced breath CO levels. An ineffective contingency management system was made effective based on these results. Study 2 examined the effectiveness of percentile schedules at reducing breath CO levels. Percentile schedules shaped lower breath CO levels. The effectiveness of percentile schedules in shaping abstinence was tested in treatment seekers, and percentile schedules were found to be effective at shaping abstinence.