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We investigate the variation of holographic complexity for two nearby target states. Based on Nielsen's geometric approach, we find the variation only depends on the end point of the optimal trajectory, a result which we designate the first law of complexity. As an example, we examine the complexity=action conjecture when the anti-de Sitter vacuum is perturbed by a scalar field excitation, which corresponds to a coherent state. Remarkably, the gravitational contributions completely cancel and the final variation reduces to a boundary term coming entirely from the scalar field action. Hence, the null boundary of Wheeler-DeWitt patch appears to act like the "end of the quantum circuit".
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Cytokinesis requires the formation of an actomyosin contractile ring between the two sets of sister chromatids. Annexin A2 is a calcium- and phospholipid-binding protein implicated in cortical actin remodeling. We report that annexin A2 accumulates at the equatorial cortex at the onset of cytokinesis and depletion of annexin A2 results in cytokinetic failure, due to a defective cleavage furrow assembly. In the absence of annexin A2, the small GTPase RhoA-which regulates cortical cytoskeletal rearrangement-fails to form a compact ring at the equatorial plane. Furthermore, annexin A2 is required for cortical localization of the RhoGEF Ect2 and to maintain the association between the equatorial cortex and the central spindle. Our results demonstrate that annexin A2 is necessary in the early phase of cytokinesis. We propose that annexin A2 participates in central spindle-equatorial plasma membrane communication.
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Anexina A2/genética , Citocinesis/genética , Osteoblastos/metabolismo , Huso Acromático/metabolismo , Anexina A2/antagonistas & inhibidores , Anexina A2/metabolismo , Sitios de Unión , Línea Celular Tumoral , Cromátides/metabolismo , Cromátides/ultraestructura , Regulación de la Expresión Génica , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Células HeLa , Humanos , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Osteoblastos/ultraestructura , Mutación Puntual , Unión Proteica , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas S100/genética , Proteínas S100/metabolismo , Transducción de Señal , Huso Acromático/ultraestructura , Proteína de Unión al GTP rhoA/genética , Proteína de Unión al GTP rhoA/metabolismo , Proteína Fluorescente RojaRESUMEN
BACKGROUND: The proposal of persistent complex bereavement disorder (PCBD) in the DSM-V increased the interest on the impact of grief on the psychological health. AIMS: Investigating the time course of psychological symptoms, emotional and social abilities in caregivers (undergoing or not to supportive-expressive treatment) of terminally ill cancer patients from 1 months before loss to 14 months after it. METHOD: Thirty-three of 60 caregivers were assessed by PG-12, HAM-A, HAM-D, TAS-20 and ASQ, at the admission in Hospice, and after 3, 10 and 14 months from the loss. Twelve caregivers adhered to follow a supportive-expressive treatment and 21 caregivers did not. RESULTS: PG-12, anxiety, and depression scores decreased in both groups over time. The score of difficulty in identifying emotions and confidence with closeness decreased significantly only in the treated-group. PG-12 score at T0 was able to predict the DSM V diagnosis of PCBD at T3. CONCLUSIONS: Findings showed a decrease of the anxiety, depression, security in the attachment style and an increase of the ability to identify emotions during the first year after loss in caregivers of terminally ill cancer patients. Pre-loss assessment of prolonged grief risk seems useful to predict the diagnosis of PCBD 1 year after loss.
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Aflicción , Cuidadores/psicología , Enfermo Terminal/psicología , Trastornos de Ansiedad/complicaciones , Trastornos de Ansiedad/psicología , Actitud Frente a la Muerte , Trastorno Depresivo/complicaciones , Trastorno Depresivo/psicología , Femenino , Pesar , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Escalas de Valoración PsiquiátricaRESUMEN
Plastic pollution is a generational problem, and stakeholders are turning to chemical recycling as a potential solution. However, decision-makers necessitate quick and reliable capital investment estimations to evaluate innovative technologies, especially in the early project stage, when limited historical data are available. To address this need, we built a database of 160+ chemical recycling plants, querying for nominal capacity, year and place of construction, total capital investment (TCI), number of long-term jobs and opportunity of subsidies. Then, we compared conventional association of the advancement of cost engineering AACE class 5 estimation methods, with literature estimates, and commercial capital expenditure confidence intervals for pyrolysis, gasification, solvolysis, and selective dissolution. We demonstrate the unreliability of classic methods, and we propose ballpark correlations based on the plant capacity, or the energy loss. Chemical recycling plants suffer from poor economy of scale (with current technologies), and capacity is not always the best indicator for TCI estimation. Pyrolysis and gasification are energy-driven technologies, and their TCI correlates very well (R2 =0.91-0.92) with the total energy losses. Solvolysis and selective dissolution, instead, are at an earlier development stage, so cost engineers or researchers will have to accept less certain TCI vs capacity (R2 =0.60).
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This study was designed to assess the use of enamel matrix derivative (EMD; Emdogain, Straumann) and alloplastic bone substitute (BoneCeramic [BC], Straumann) in postextraction alveolar sockets. A total of 45 patients requiring anterior single tooth extractions and subsequent implant placement were recruited and randomly assigned to one of three treatment groups. Postextraction sockets were filled with BC or BC + EMD, or were left to heal spontaneously. Tomographic dimensional changes were measured immediately following tooth extraction and at the 6-month follow-up. Computed tomographic (CT) scans were taken with a radiographic stent within 48 hours of extraction (CT1) and at 6 months (CT2). Paired comparisons related to the mean horizontal reduction of the vestibular crest (VC) showed significant differences between sockets left to heal spontaneously (Group 1) and the two groups filled with BC (Group 2) and BC + EMD (Group 3): 1.7 mm for Group 1 and 0.9 mm for Groups 2 and 3 (P < .05). Thus, the use of alloplastic bone substitute alone or with EMD resulted in better preservation of postextraction socket dimensions. No differences in socket preservation were found between Group 2 (BC) and Group 3 (BC + EMD). Int J Periodontics Restorative Dent 2023;43:e117-e124. doi: 10.11607/prd.5820.
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Pérdida de Hueso Alveolar , Sustitutos de Huesos , Humanos , Sustitutos de Huesos/uso terapéutico , Proceso Alveolar/diagnóstico por imagen , Proceso Alveolar/cirugía , Alveolo Dental/diagnóstico por imagen , Alveolo Dental/cirugía , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/cirugía , Extracción Dental/métodosRESUMEN
Dental pulp and periodontium have different communication routes including, e.g., apical foramen, accessory canals and dentin tubules. Scaling, planing and root surface treatment with ethylenediaminetetraacetic acid (EDTA)-based conditioner are used in regenerative periodontal procedures. Such treatment may generate pathological communication between the two structures due to interruption of the vascular pedicle or migration of bacteria and/or inflammatory byproducts from deep periodontal pockets, which may generate pulp pathology. Aim: The aim of this study was to evaluate the influence of minimally invasive periodontal regenerative surgery on pulp vitality status in single-rooted and multi-rooted teeth associated to infraosseous defects extending to the middle and apical thirds. Materials and Method: This was a retrospective study on 30 teeth from 14 patients who received care between August 2018 and August 2019 at the postgraduate Department of Specialization in Periodontics of the Buenos Aires University School ofDentistry (FOUBA). Clinical and radiographic endodontic diagnosis was performed 6 months after the minimally invasive regenerative periodontal treatment. Results: Only two out of the 30 teeth presented changes in pulp status following regenerative periodontal procedure: irreversible pulpitis at 30 days and pulp necrosis at 180 days post-treatment. The rate for risk of change in pulp vitality status was 6.7%. Teeth with grade I and II furcation lesions (n=9) presented no change in pulp status. Conclusions: Regenerative periodontal surgery had no significant influence on pulp status in single-rooted and multi-rooted teeth with infraosseous defects extending to the level of the middle and apical third.
La pulpa dental y el periodonto presentan diferentes vías de comunicación. El foramen apical, los conductos accesorios y los túbulos dentinarios son ejemplos de ellos. Durante los procedimientos peri-odontales regenerativos se realiza el raspaje, alisado y tratamiento de la superficie radicular con un acondicionador a base de ácido etilendiaminotetraacético (EDTA). Este tratamiento podría generar una comunicación patológica entre ambas estructuras debido a la interrupción del pedículo vascular o a la migración de bacterias y/o subproductos inflamatorios provenientes de bolsas periodontales profundas que generen patología pulpar. Objetivo: El objetivo del presente estudio fue evaluar la influencia de la cirugía periodontal regenerativa mínimamente invasiva sobre el estado de vitalidad pulpar de piezas dentarias unirradiculares y multirradiculares con defectos infraóseos que se extendían hasta el tercio medio y apical. Materiales y Método: Se analizaron de forma retrospectiva 30 piezas dentarias de 14 pacientes atendidos entre el mes de agosto 2018 y agosto 2019 en el posgrado de la Especial-ización en Periodoncia de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA). Se realizó el diagnóstico endodóntico de forma clínica y radiográfica a los 6 meses post-tratamiento periodontal regenerativo mínimamente invasivo. Resultados: De las 30 piezas solo 2 presentaron cambios en el estado pulpar luego del procedimiento periodontal regenerativo, pulpitis irreversibles a los 30 días y necrosis pulpar a los 180 días post-tratamiento. La tasa de riesgo de cambios en el estado de vitalidad pulpar fue del 6,7%. En relación a las piezas dentarias que presentaban lesiones de furcación grado I y II (n=9) ninguna presentó cambios en su estado pulpar. Conclusiones: La cirugía periodontal regenerativa no tuvo influencia significativa en el estado pulpar de piezas unirradiculares y multirra-diculares con defectos infraóseos que se extendían a nivel del tercio medio y apical.
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Comunicación , Atención Odontológica , Humanos , Estudios Retrospectivos , Cavidad Pulpar , RegeneraciónRESUMEN
BACKGROUND: Reduced alveolar ridge volume is an often consequence after tooth loss, compromising implant placement and prosthetic rehabilitation. The digital customization of bone block allografts (BBA) is an alternative that incorporates advantages such as intimate contact with the recipient bed, increasing graft stability and reduced surgical time. In addition, enamel matrix derivate (EMD) has attracted interest for its effect on osteogenic gene expression and cell adhesion; few studies have focused on the benefits of bone regeneration with EMD. The aim of this case report is to present the reconstruction of a severely atrophic alveolar ridge defect with a digitally customized bone block allograft (CBBA) in combination with EMD as an adjuvant for bone regeneration and soft tissue healing. METHODS: Initially, the digital planning and manufacture of the BBA was performed based on an initial cone beam computed tomography (CBCT) scan. EMD was applied to the recipient site and to the CBBA before graft fixation. After 6 months, bone biopsies were obtained on re-entry surgery for prosthetically guided implant placement. RESULTS: Clinically, bone block showed good integration with the adjacent tissue and no signs of rejection or necrosis were found. On the histological evaluation, new bone was observed in intimate contact with the allograft and showed viable osteocytes and osteoblasts along its entire length. Residual allograft particles were observed to be highly osteoconductive. CONCLUSION: According to the clinical and histological results presented, the digital customization of the BBA allows an ideal graft fit to the recipient bed with excellent results in bone regeneration.
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Aggressive periodontitis (AP) is the most serious entity of periodontal disease (stage III/IV, grade C periodontitis according to the latest classification, 2017). Aim: to enhance knowledge of periodontal microbiota in AP in native Argentine patients and describe the effect of a combined pharmacologicalmechanical periodontal treatment on clinical and microbiological parameters. Materials and Method: The study analyzed 42 periodontal sites in 11 patients diagnosed with AP. Clinical periodontal parameters were recorded at baseline, 45, 90 and 180 days. Microbiological samples were taken before treatment and at 180 days. PCR was used to determine presence of the periodontopathic bacteria Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn). Patients underwent periodontal therapy including antibiotics (Amoxicillin 500mg + Metronidazole 250mg; 8hs/7 days), and were reevaluated at 45, 90 and 180 days. Results: Mean age was 28.4 ± 7.9 years. The initial PCR detected the following frequencies: Aa 14.3%, Pi 61.9%, Pg 71.4%, Tf 81.0%, Fn 95.2% and Td 97.6%. Baseline microbiological samples revealed significantly higher prevalence of Pg over Aa (p=0.012). Clinical parameters improved significantly after treatment (73.8% PS<5 mm; PS, NIC, SS p<0.001). At 180 days, a significant decrease in microbiological detection rates was observed (Fn, Td, Tf, Pi, Aa p<0.05). Aa was no longer detectable while Pg did not decrease significantly (p=0.052). Fn was the only study species detected in 100% (n=11:42) of residual pockets (PS≥5 mm) (p=0.053). Conclusion: In the initial samples, there was significant prevalence of Pg over Aa. Significant clinical improvement was achieved after the mechanical-pharmacological treatment, with undetectable levels of Aa, while Fn persisted in residual pockets, and Pg was present at most of the treated sites.
La periodontitis agresiva (PA) es la entidad más grave de la enfermedad periodontal (clasificación 2017: periodontitis estadio III/IV, grado C). Objetivo: mejorar el conocimiento sobre la microbiota periodontal de la PA en sujetos nativos argentinos y describir el efecto de un tratamiento mecánicofarmacológico periodontal sobre los parámetros clínicos y microbiológicos. Materiales y Método: se estudiaron 42 sitios periodontales correspondientes a 11 pacientes con PA. Los parámetros clínicos se registraron a 0, 45, 90 y 180 días. Las tomas microbiológicas se realizaron antes de iniciar el tratamiento y a los 180 días. La determinación de especies periodontopáticas (Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi) y Fusobacterium nucleatum (Fn)) se realizó por PCR. Los pacientes iniciaron terapia básica periodontal junto con antibioticoterapia (Amoxicilina 500 mg + Metronidazol 250 mg; 8 hs/7 días) y fueron evaluados a los 45, 90 y 180 días. Resultados: la edad media fue 28,4 ± 7,9 años. Las detecciones iniciales fueron: Aa 14,3%, Pi 61,9%, Pg 71,4%, Tf 81,0%, Fn 95,2% y Td 97,6%. En las muestras iniciales la prevalencia de Pg sobre Aa fue significativamente superior (p=0,012). Los pacientes tuvieron una respuesta clínica favorable al tratamiento (73,8% PS<5 mm; PS, NIC, SS p<0,001). A 180 días, se observó una disminución estadísticamente significativa en la detección microbiana (Fn, Td, Tf, Pi, Aa p<0,05). En igual plazo, Aa no fue detectado, mientras que Pg mostró una disminución no significativa (p=0,052). Fn fue el único detectado en el 100% (n=11:42) de las bolsas periodontales residuales (PS≥5 mm) (p=0,053). Conclusión: Las muestras iniciales evidenciaron prevalencia significativa de Pg sobre Aa. El tratamiento logró una significativa mejora clínica con niveles indetectables de Aa. La persistencia de Fn en las bolsas residuales y de Pg en la mayoría de los sitios tratados, caracterizaron la muestra poblacional estudiada
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Periodontitis Agresiva , Humanos , Adulto Joven , Adulto , Porphyromonas gingivalis , Aggregatibacter actinomycetemcomitans , Amoxicilina , Antibacterianos/uso terapéuticoRESUMEN
The discovery of a pufferfish specimen (Tetraodontidae) inside a frozen cuttlefish, purchased by a fishmonger, and caught in the Eastern Central Atlantic (FAO 34) is reported. The consumer, who reported this case to FishLab (Department of Veterinary Sciences, University of Pisa) for investigation, was a student of Veterinary Medicine at the University of Pisa. He recognized the Tetraodontidae because he attended practical lessons on fish morphological identification during the course of food inspection and was aware of the risks to human health linked to the Tetrodotoxin (TTX). In this study, the pufferfish was identified morphologically, using the FAO morphological keys, and molecularly, analyzing two markers, the cytochrome oxidase I (COI) and the cytochrome b genes, by DNA barcoding. The pufferfish was identified morphologically as Sphoeroides spp., and molecularly as Sphoeroides marmoratus using the COI gene (99-100% identity values). Literature reports that S. marmoratus from the Eastern Atlantic contains high concentrations of TTX in the gonads and the digestive tract. However, the possible passage of TTX from fish to other organisms linked to contact or ingestion has never been reported. This represents the first case of a potentially toxic pufferfish entering the market inside another organism. The fact that a student observed this occurrence highlights the key role of citizen science in the management of emerging risks.
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The aim of this study is to present a predictable method for evaluating dimensional changes in the alveolar ridge through cone beam computed tomography (CT). Twenty subjects with single-rooted tooth extraction indication were selected for this preliminary report, which is part of a larger ongoing investigation. After extraction, two CT scans were performed; the first within 24 hours post-extraction (TC1) and the second 6 months (TC2) later. A radiographic guide with a radiopaque element placed along the tooth axis was developed to locate the same plane of reference in two different CT scans. For each patient, backtrack analysis was performed in order to establish the reproducibility error of a predetermined point in space between two CT scans. Briefly, an anatomical landmark was selected and its coordinates to the radiopaque marker were recorded. One week later, the coordinates were followed backwards in the same CT scan to obtain the position where the reference point should be located. A similar process was carried out between two different CT scans taken 6 months apart. The distance between the anatomical reference and the obtained point of position was calculated to establish the accuracy of the method. Additionally, a novel method for evaluating dimensional changes of the alveolus after tooth extraction is presented. The backtrack analysis determined an average within-examiner discrepancy between both measurements from the same CT scan of 0.19 mm. SD +/- 0.05. With the method presented herein, a reference point in a CT scan can be accurately backtracked and located in a second CT scan taken six months later. Taken together they open the possibility of calculating dimensional changes that occur in the alveolar ridge over time, such as post-extraction alveolar resorption, or the bone volume gained after different augmentation procedures.
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Proceso Alveolar/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico , Extracción Dental , Alveolo Dental/diagnóstico por imagen , Humanos , Periodo Posoperatorio , Adulto JovenRESUMEN
This study was designed to assess the effect of enamel matrix derivative (Emdogain, Straumann) and alloplastic bone substitute (BoneCeramic, Straumann) on new bone formation in postextraction alveolar sockets. Twenty-one patients requiring anterior single-tooth extractions and subsequent implant placement were recruited and randomly assigned to one of three treatment groups. Postextraction sockets were filled with either an alloplastic bone substitute (BoneCeramic [BC]), BC combined with Emdogain (EMD+BC), or left to heal spontaneously (SO). Histologic and histomorphometric analyses of the results were performed at 6 months postextraction. A significant increase in the percentage of new bone tissue area was found in EMD+BC compared to SO and BC groups. These findings demonstrate that compared with BC or SO, EMD+BC allowed for better formation of new bone in postextraction sockets after 6 months of healing.
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Pérdida de Hueso Alveolar , Sustitutos de Huesos , Pérdida de Hueso Alveolar/patología , Sustitutos de Huesos/farmacología , Sustitutos de Huesos/uso terapéutico , Humanos , Extracción Dental , Alveolo Dental/patología , Alveolo Dental/cirugía , Cicatrización de HeridasRESUMEN
Authorship is the currency of an academic career for which the number of papers researchers publish demonstrates creativity, productivity, and impact. To discourage coercive authorship practices and inflated publication records, journals require authors to affirm and detail their intellectual contributions but this strategy has been unsuccessful as authorship lists continue to grow. Here, we surveyed close to 6000 of the top cited authors in all science categories with a list of 25 research activities that we adapted from the National Institutes of Health (NIH) authorship guidelines. Responses varied widely from individuals in the same discipline, same level of experience, and same geographic region. Most researchers agreed with the NIH criteria and grant authorship to individuals who draft the manuscript, analyze and interpret data, and propose ideas. However, thousands of the researchers also value supervision and contributing comments to the manuscript, whereas the NIH recommends discounting these activities when attributing authorship. People value the minutiae of research beyond writing and data reduction: researchers in the humanities value it less than those in pure and applied sciences; individuals from Far East Asia and Middle East and Northern Africa value these activities more than anglophones and northern Europeans. While developing national and international collaborations, researchers must recognize differences in peoples values while assigning authorship.
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Autoria , National Institutes of Health (U.S.) , Edición , Investigadores , Humanos , Estados UnidosRESUMEN
TiO2 is employed as both photocatalytic and structural materials, leading to its applications in external coatings or in interior furnishing devices, including cement mortar, tiles, floorings, and glass supports. The authors have already demonstrated the efficiency of photoactive micro-sized TiO2 and here its industrial use is reported using the digital printing to coat porcelain grés slabs. Many advantages are immediately evident, namely rapid and precise deposition, no waste of raw materials, thus positively affecting the economy of the process. Data for the thin films deposited by digital printing were compared with those obtained for the conventional spray method. The use of metal-doped TiO2 is also reported so that the photoactivity of these materials can be exploited even under LED light. The digital inkjet printed coatings exhibited superior photocatalytic performance owing to both higher exposed surface area and greater volume of deposited anatase, as well as the greater areal distribution density of thinly and thickly coated regions. Moreover, the presence of TiO2 doped silver increased the efficiency of the materials in NOx degradation both under UVA and LED lights.
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Contaminación del Aire Interior/prevención & control , Materiales de Construcción , Nanopartículas/química , Plata/química , Titanio/química , Rayos Ultravioleta , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/efectos de la radiación , Catálisis , Óxidos de Nitrógeno/análisis , Óxidos de Nitrógeno/efectos de la radiación , Impresión Tridimensional , Propiedades de SuperficieRESUMEN
BACKGROUND: Cystic fibrosis affects 1/3200 Caucasians. This genetic disease disturbs the ion and water homeostasis across epithelia, thus rendering mucus more viscous and harder to expel. Conventional treatments rely on the clapping method coupled with postural drainage. Despite the effectiveness of these procedures, they are invasive and enervating. METHODS: Here we study a new mechano-acoustic treatment device to help patients expectorate excess mucus, the Frequencer™. We test both normal and pathological synthetic mucin solutions (1 % and 4 % by weight) in vitro. We varied the frequency applied (from 20 Hz to 60 Hz) as well as the amplitude (from 50 % to 100 % intensity). Moreover, we assessed the effect of NaCl on mucus rehydration. RESULTS: A frequency of 40 Hz coupled with a 0.5 gL-1NaCl solution provokes partial mucus rehydration, regardless of the amplitude selected, as the work of adhesion measurements evidenced. CONCLUSIONS: Mechanical solicitation is fundamental to help patients affected by cystic fibrosis expectorate mucus. With an operating frequency of 20â¯Hz to 65 Hz, the Frequencer™ provides a gentler therapy than traditional methods (conventional chest physiotherapy). The Frequencer™ proved to be effective in the homogenization of synthetic mucin solutions in vitro in 20 min and elicited improved effectiveness in a mucin-rich environment.
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Acústica/instrumentación , Fibrosis Quística/terapia , Drenaje Postural/instrumentación , Moco/química , Animales , Fibrosis Quística/epidemiología , Fibrosis Quística/fisiopatología , Humanos , Fenómenos Mecánicos , Moco/efectos de los fármacos , Moco/fisiología , Modalidades de Fisioterapia/normas , Modalidades de Fisioterapia/estadística & datos numéricos , Ondas de Radio/efectos adversos , Solución Salina/efectos adversos , Solución Salina/uso terapéutico , Porcinos , Sustancias Viscoelásticas/químicaRESUMEN
A fraction of the petroleum extracted from oil reservoirs contains associated natural gas. Rather than building infrastructure to recover low volumes of this natural gas, the industry flares or vents it to the atmosphere, which contributes to atmospheric greenhouse gas emissions but also reduces the air quality locally because it contains gaseous sulphur and nitrogen compounds. Converting the natural gas (NG) to hydrocarbons with a small-scale two-step gas-to-liquids process, is an alternative to flaring and venting. In the first step, NG reacts with oxygen to form syngas (Catalytic Partial Oxidation) and in the second step the syngas reacts over metallic catalysts to form higher paraffins at 210⯰C to 300⯰C-Fischer Tropsch synthesis (FT). For the first time, we synthesize bimetallic FeCo FT catalysts with ultrasound. An ultrasonic horn agitates the solution during the entire impregnation process. The active phase dispersion of the sonicated catalysts was superior to the catalyst synthesized without ultrasound, while reducing the impregnation time by a factor of three. We tested our catalysts in a lab-scale, fixed-bed reactor at 270⯰C and 300⯰C, and achieved 80% conversion over 3-days on stream and a 40% yield of C2+.
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Volatile and semi volatile organic compounds' concentration have dramatically increased in indoor environments in recent years. UV light promotes titanium dioxide, which oxidises various molecules; however, most of the studies report the degradation of a single VOC. Here, we investigate the photo-oxidation of 17 molecules in mixture to have a realistic test of TiO2 efficacy. We compare P25, a nanometric catalyst, and 1077, a micrometric sample, that poses less health concerns. A proton-transfer-reaction mass spectrometer measured online the concentration of all the pollutants simultaneously. Aldehydes compete for the adsorption on both the catalyst's active sites and thus they degrade 70% and 55% with P25 and 1077 respectively. Considering the single pollutant oxidation, instead, aldehydes fully oxidize. Even though benzene is recalcitrant to degradation, P25 and 1077 reduced toluene's concentration to 97% and 96% in 55 min, respectively. Acetonitrile is refractory to photocatalysis.
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Modelos Químicos , Procesos Fotoquímicos , Titanio/química , Compuestos Orgánicos Volátiles/química , Adsorción , Contaminantes Atmosféricos/análisis , Aldehídos , Benceno , Catálisis , Oxidación-Reducción , Fotólisis , Tolueno , Rayos UltravioletaRESUMEN
ABSTRACT Aggressive periodontitis (AP) is the most serious entity of periodontal disease (stage III/IV, grade C periodontitis according to the latest classification, 2017). Aim: to enhance knowledge of periodontal microbiota in AP in native Argentine patients and describe the effect of a combined pharmacological-mechanicalperiodontal treatment on clinical and microbiological parameters. Materials andMethod: The study analyzed 42 periodontal sites in 11 patients diagnosed with AP. Clinical periodontal parameters were recorded at baseline, 45, 90 and 180 days. Microbiological samples were taken before treatment and at 180 days. PCR was used to determine presence of the periodontopathic bacteria Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn). Patients underwent periodontal therapy including antibiotics (Amoxicillin 500mg + Metronidazole 250mg; 8hs/7 days), and were reevaluated at 45, 90 and 180 days. Results: Mean age was 28.4 ± 7.9 years. The initial PCR detected the following frequencies: Aa 14.3%, Pi 61.9%, Pg 71.4%, Tf 81.0%, Fn 95.2% and Td 97.6%. Baseline microbiological samples revealed significantly higher prevalence of Pg over Aa (p=0.012). Clinical parameters improved significantly after treatment (73.8% PS<5 mm; PS, NIC, SS p<0.001). At 180 days, a significant decrease in microbiological detection rates was observed (Fn, Td, Tf, Pi, Aa p<0.05). Aa was no longer detectable while Pg did not decrease significantly (p=0.052). Fn was the only study species detected in 100% (n=11:42) of residual pockets (PS>5 mm) (p=0.053). Conclusion: In the initial samples, there was significant prevalence of Pg over Aa. Significant clinical improvement was achieved after the mechanical-pharmacological treatment, with undetectable levels ofAa, while Fn persisted in residual pockets, and Pg was present at most of the treated sites.
RESUMEN La periodontitis agresiva (PA) es la entidad más grave de la enfermedad periodontal (clasificación 2017: periodontitis estadio III/IV, grado C). Objetivo: mejorar el conocimiento sobre la microbiota periodontal de la PA en sujetos nativos argentinos y describir el efecto de un tratamiento mecánico-farmacológico periodontal sobre los parámetros clínicos y microbiológicos. Materiales y Método: se estudiaron 42 sitios periodontales correspondientes a 11 pacientes con PA. Los parámetros clínicos se registraron a 0, 45, 90 y 180 días. Las tomas microbiológicas se realizaron antes de iniciar el tratamiento y a los 180 días. La determinación de especies periodontopáticas (Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf, Treponema denticola (Td), Prevotella intermedia (Pi) y Fusobacterium nucleatum (Fn)) se realizó por PCR. Los pacientes iniciaron terapia básica periodontal junto con antibioticoterapia (Amoxicilina 500 mg + Metronidazol 250 mg; 8 hs/7 días) y fueron evaluados a los 45, 90 y 180 días. Resultados: la edad media fue 28,4 ± 7,9 años. Las detecciones iniciales fueron: Aa 14,3%, Pi 61,9%, Pg 71,4%, Tf 81,0%, Fn 95,2% y Td 97,6%. En las muestras iniciales la prevalencia de Pg sobre Aa fue significativamente superior (p=0,012). Los pacientes tuvieron una respuesta clínica favorable al tratamiento (73,8% PS<5 mm; PS, NIC, SS p<0,001). A 180 días, se observó una disminución estadísticamente significativa en la detección microbiana (Fn, Td, Tf, Pi, Aa p<0,05). En igual plazo, Aa no fue detectado, mientras que Pg mostró una disminución no significativa (p=0,052). Fn fue el único detectado en el 100% (n=11:42) de las bolsas periodontales residuales (PS>5 mm) (p=0,053). Conclusión: Las muestras iniciales evidenciaron prevalencia significativa de Pg sobre Aa. El tratamiento logró una significativa mejora clínica con niveles indetectables de Aa. La persistencia de Fn en las bolsas residuales y de Pg en la mayoría de los sitios tratados, caracterizaron la muestra poblacional estudiada.
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ABSTRACT Dental pulp and periodontium have different communication routes including, e.g., apical foramen, accessory canals and dentin tubules. Scaling, planing and root surface treatment with ethylenediaminetetraacetic acid (EDTA)-based conditioner are used in regenerative periodontal procedures. Such treatment may generate pathological communication between the two structures due to interruption of the vascular pedicle or migration of bacteria and/or inflammatory byproducts from deep periodontal pockets, which may generate pulp pathology. Aim: The aim of this study was to evaluate the influence of minimally invasive periodontal regenerative surgery on pulp vitality status in single-rooted and multi-rooted teeth associated to infraosseous defects extending to the middle and apical thirds. Materials and Method: This was a retrospective study on 30 teeth from 14 patients who received care between August 2018 and August 2019 at the postgraduate Department of Specialization in Periodontics of the Buenos Aires University School ofDentistry (FOUBA). Clinical and radiographic endodontic diagnosis was performed 6 months after the minimally invasive regenerative periodontal treatment. Results: Only two out of the 30 teeth presented changes in pulp status following regenerative periodontal procedure: irreversible pulpitis at 30 days and pulp necrosis at 180 days post-treatment. The rate for risk of change in pulp vitality status was 6.7%. Teeth with grade I and II furcation lesions (n=9) presented no change in pulp status. Conclusions: Regenerative periodontal surgery had no significant influence on pulp status in single-rooted and multi-rooted teeth with infraosseous defects extending to the level of the middle and apical third
RESUMEN La pulpa dental y el periodonto presentan diferentes vías de comunicación. El foramen apical, los conductos accesorios y los túbulos dentinarios son ejemplos de ellos. Durante los procedimientos peri-odontales regenerativos se realiza el raspaje, alisado y tratamiento de la superficie radicular con un acondicionador a base de ácido etilendiaminotetraacético (EDTA). Este tratamiento podría generar una comunicación patológica entre ambas estructuras debido a la interrupción del pedículo vascular o a la migración de bacterias y/o subproductos inflamatorios provenientes de bolsas periodontales profundas que generen patología pulpar. Objetivo: El objetivo del presente estudio fue evaluar la influencia de la cirugía periodontal regenerativa mínimamente invasiva sobre el estado de vitalidad pulpar de piezas dentarias unirradiculares y multirradiculares con defectos infraóseos que se extendían hasta el tercio medio y apical. Materiales y Método: Se analizaron de forma retrospectiva 30 piezas dentarias de 14 pacientes atendidos entre el mes de agosto 2018 y agosto 2019 en el posgrado de la Especial-ización en Periodoncia de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA). Se realizó el diagnóstico endodóntico de forma clínica y radiográfica a los 6 meses post-tratamiento periodontal regenerativo mínimamente invasivo. Resultados: De las 30 piezas solo 2 presentaron cambios en el estado pulpar luego del procedimiento periodontal regenerativo, pulpitis irreversibles a los 30 días y necrosis pulpar a los 180 días post-tratamiento. La tasa de riesgo de cambios en el estado de vitalidad pulpar fue del 6,7%. En relación a las piezas dentarias que presentaban lesiones de furcación grado I y II (n=9) ninguna presentó cambios en su estado pulpar. Conclusiones: La cirugía periodontal regenerativa no tuvo influencia significativa en el estado pulpar de piezas unirradiculares y multirra-diculares con defectos infraóseos que se extendían a nivel del tercio medio y apical.
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Malaria devastates sub-Saharan Africa; the World Health Organization (WHO) estimates that 212 million people contract malaria annually and that the plasmodium virus will kill 419 000 in 2017. The disease affects rural populations who have the least economic means to fight it. Impregnated mosquito nets have reduced the mortality rate but the Anopheles mosquitoes are changing their feeding patterns and have become more active at dusk and early morning rather than after 22h00 as an adaptation to the nets. Everyone is susceptible to the Anopheles at these times but infants and pregnant women are the most vulnerable to the disease. Plant-based mosquito repellents are as effective as synthetic repellents that protect people from bites. They are sustainable preventative measures against malaria not only because of their efficacy but because the local population can produce and distribute them, which represents a source of economic growth for rural areas. Here, we extract and test the essential oil nepetalactone from Nepeta cataria via steam distillation. Families in endemic areas of Burundi found them effective against bites but commented that the odor was pungent. An epidemiological study is required to establish its clinical efficacy.