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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 303: 123281, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37625276

RESUMEN

A supramolecular assembly was obtained by combining methylene blue (MB) with a natural plant extract, curcumin (Curc), in a stoichiometric ratio of 1:4 in aqueous solution (90% PBS + 10% ethanol) at room temperature. The MB-Curc supramolecular assembly was evidenced by absorption and fluorescence spectroscopies, and the stoichiometry and bonding constant were obtained using Cielens model. Its stability and photostability were evaluated by chromatographic analysis and UV-Vis absorption. The MB-Curc avoids the aggregation of both isolated compounds and efficiently produces singlet oxygen (ΦΔ= 0.52 ± 0.03). Its potential for photodynamic antiangiogenic treatments was evaluated through the vascular effect observed in chicken chorioallantoic membrane (CAM) assay. The results showed intense damage in CAM vascular network by MB-Curc after irradiation, which is higher than the effect of isolated compounds, indicating a synergistic vascular effect. This combination can be essential to prevent cancer revascularization after photodynamic application and improve the efficacy of this approach. The characteristics exhibited by MB-Curc make it a potential candidate for use in cancer treatments through photodynamic antiangiogenic therapy.


Asunto(s)
Curcumina , Animales , Curcumina/farmacología , Azul de Metileno/farmacología , Bioensayo , Pollos , Membrana Corioalantoides
2.
ACS Omega ; 8(25): 23008-23016, 2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37396260

RESUMEN

An original total synthesis of the antiepileptic drug brivaracetam (BRV) is reported. The key step in the synthesis consists of an enantioselective photochemical Giese addition, promoted by visible-light and the chiral bifunctional photocatalyst Δ-RhS. Continuous flow conditions were employed to improve the efficiency and allow an easy scale-up of the enantioselective photochemical reaction step. The intermediate obtained from the photochemical step was converted into BRV by two different pathways, followed by one alkylation and amidation, thus giving the desired active pharmaceutical ingredients (API) in 44% overall yield, 9:1 diastereoisomeric ratio (dr) and >99:1 enantiomeric ratio (er).

3.
Biomimetics (Basel) ; 8(3)2023 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-37504205

RESUMEN

Degenerative diseases and injuries that compromise hand movement reduce individual autonomy and tend to cause financial and psychological problems to their family nucleus. To mitigate these limitations, over the past decade, hand exoskeletons have been designed to rehabilitate or enhance impaired hand movements. Although promising, these devices still have limitations, such as weight and cost. Moreover, the movements performed are not kinematically compatible with the joints, thereby reducing the achievements of the rehabilitation process. This article presents the biomimetic design of a soft hand exoskeleton actuated using artificial tendons designed to achieve low weight, volume, and cost, and to improve kinematic compatibility with the joints, comfort, and the sensitivity of the hand by allowing direct contact between the hand palm and objects. We employed two twisted string actuators and Bowden cables to move the artificial tendons and perform the grasping and opening of the hand. With this configuration, the heavy part of the system was reallocated to a test bench, allowing for a lightweight set of just 232 g attached to the arm. The system was triggered by the myoelectric signals of the biceps captured from the user's skin to encourage the active participation of the user in the process. The device was evaluated by five healthy subjects who were asked to simulate a paralyzed hand, and manipulate different types of objects and perform grip strength. The results showed that the system was able to identify the intention of movement of the user with an accuracy of 90%, and the orthosis was able to enhance the ability of handling objects with gripping force up to 1.86 kgf.

4.
Otolaryngol Head Neck Surg ; 169(2): 367-373, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36805618

RESUMEN

OBJECTIVE: Microtia is a congenital condition known to be associated with vertebral anomalies and congenital syndromes, most prominently hemifacial microsomia. There is controversy, however, on whether to screen with spinal imaging. Additionally, microtia ear reconstruction utilizes rib harvesting that could potentially worsen pre-existing vertebral and rib anomalies, specifically scoliosis. We report on the prevalence and characteristics of vertebral anomalies among microtia patients at a tertiary pediatric center. STUDY DESIGN: Retrospective case review with literature review. SETTING: Tertiary pediatric referral center. METHODS: A review of 425 children with microtia was conducted, characterized as either syndromic or nonsyndromic. Data included demographics, spinal imaging performed, indications, anomalies detected, and microtia repair. RESULTS: Among 425 microtia patients, 24.5% were syndromic with an average age of 9.7 years. Only 18.4% of all patients had spinal imaging performed (50% syndromic vs 8.1% nonsyndromic). Overall, 10.6% had a vertebral anomaly with a 57.7% detection rate (67.3% syndromic vs 38.5% nonsyndromic). The most common anomaly was scoliosis, with a prevalence of 7.8%. Fusion defects and rib deformities were the next most prominent. Microtia repair, most commonly with an autologous rib graft, was performed in 21.6% of the cohort. However, only 19.2% had spinal imaging and 16.7% with a vertebral anomaly. CONCLUSION: Children with microtia are at a greater risk of vertebral abnormalities. Scoliosis prevalence in isolated microtia is comparable to the general population (2%-3%) but greatly increased with genetic syndromes. Screening for vertebral anomalies should be considered when planning microtia reconstructions, especially in the syndromic population.


Asunto(s)
Microtia Congénita , Escoliosis , Niño , Humanos , Microtia Congénita/epidemiología , Microtia Congénita/complicaciones , Escoliosis/epidemiología , Escoliosis/cirugía , Escoliosis/complicaciones , Estudios Retrospectivos , Columna Vertebral/cirugía , Columna Vertebral/anomalías
5.
Otolaryngol Head Neck Surg ; 168(3): 478-483, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35763369

RESUMEN

OBJECTIVES: To determine the incidence and impact of monopolar cautery use in a cohort of pediatric cochlear implant (CI) users. STUDY DESIGN: Case series from a retrospective chart review and a systematic review of the literature. SETTING: Tertiary academic referral center. METHODS: CI patient charts from 2012 to 2021 were reviewed from a single pediatric hospital system to determine if monopolar cautery was used during a subsequent surgical procedure. In addition, a systematic review of the literature was performed to identify additional, relevant patients. Postoperative CI function was the primary outcome measure. RESULTS: In total, 190 patients underwent a surgical procedure following cochlear implantation in a single pediatric hospital system. Fifteen patients (7.9%) and 17 distinct surgical procedures were identified in which monopolar cautery was used. Seven of these 17 cases (41.2%) involved the head and neck, and 10 were performed below the clavicles. No patients experienced a device failure or a decline in CI performance following surgery. A systematic review identified an additional 4 patients who underwent a surgery that used monopolar cautery following cochlear implantation, and no change in CI function was identified. CONCLUSIONS: The present study adds additional support to the notion that monopolar cautery does not necessarily injure CI functionality. While the most risk adverse strategy when planning a surgical procedure for a CI patient is to avoid monopolar cautery use altogether, the use of cautery should not immediately be associated with implant dysfunction.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Humanos , Niño , Estudios Retrospectivos , Cauterización , Electrocoagulación/efectos adversos
6.
Chem Sci ; 13(42): 12527-12532, 2022 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-36382292

RESUMEN

The efficient C-4 selective modification of pyridines is a major challenge for the synthetic community. Current strategies are plagued with at least one drawback regarding functional group-tolerant electronic activation of the heteroarene, mild generation of the required alkyl radicals, regioselectivity, safety and/or scalability. Herein, we describe a fast, safe and scalable flow process which allows preparation of said C-4 alkylated pyridines. The process involves a photochemical hydrogen atom transfer (HAT) event to generate the carbon-centered radicals needed to alkylate the C-2 blocked pyridine. In a two-step streamlined flow process, this light-mediated alkylation step is combined with a nearly instantaneous inline removal of the blocking group. Notably, cheap benzophenone plays a dual role in the pyridine alkylation mechanism by activating the hydrocarbon feedstock reagents via a HAT mechanism, and by acting as a benign, terminal oxidant. The key role of benzophenone in the operative reaction mechanism has also been revealed through a combination of experimental and computational studies.

7.
J Org Chem ; 87(9): 5630-5642, 2022 05 06.
Artículo en Inglés | MEDLINE | ID: mdl-35421314

RESUMEN

While photochemical transformations with sunlight almost exclusively utilize the UV-vis part of the solar spectrum, the majority of the photons emitted by the sun have frequencies in the near-infrared region. Phthalocyanines show high structural similarity to the naturally occurring light-harvesting porphyrins, chlorins, and mainly bacteriochlorins and are also known for being efficient and affordable near-infrared light absorbers as well as triplet sensitizers for the production of singlet oxygen. Although having been neglected for a long time in synthetic organic chemistry due to their low solubility and high tendency toward aggregation, their unique photophysical properties and chemical robustness make phthalocyanines attractive photocatalysts for the application in near-infrared-light-driven synthesis strategies. Herein, we report a cheap, simple, and efficient photocatalytic protocol, which is easily scalable under continuous-flow conditions. Various phthalocyanines were studied as near-infrared photosensitizers in oxidative cyanations of tertiary amines to generate α-aminonitriles, a synthetically versatile compound class.


Asunto(s)
Compuestos Organometálicos , Indoles/química , Isoindoles , Compuestos Organometálicos/química , Fármacos Fotosensibilizantes , Compuestos de Zinc
8.
Ann Otol Rhinol Laryngol ; 131(4): 373-378, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34109843

RESUMEN

OBJECTIVE: Microtia reconstruction is technically challenging due to the intricate contours of the ear. It is common practice to use a two-dimensional tracing of the patient's normal ear as a template for the reconstruction of the affected side. Recent advances in three-dimensional (3D) surface scanning and printing have expanded the ability to create surgical models preoperatively. This study aims to describe a simple and affordable process to fabricate patient-specific 3D ear models for use in the operating room. STUDY DESIGN: Applied basic research on a novel 3D optical scanning and fabrication pathway for microtia reconstruction. SETTING: Tertiary care university hospital. METHODS: Optical surface scanning of the patient's normal ear was completed using a smartphone with facial recognition capability. The Heges application used the phone's camera to capture the 3D image. The 3D model was digitally isolated and mirrored using the Meshmixer software and printed with a 3D printer (MonopriceTM Select Mini V2) using polylactic acid filaments. RESULTS: The 3D model of the ear served as a helpful intraoperative reference and an adjunct to the traditional 2D template. Collectively, time for imaging acquisition, editing, and fabrication was approximately 3.5 hours. The upfront cost was around $210, and the recurring cost was approximately $0.35 per ear model. CONCLUSION: A novel, low-cost approach to fabricate customized 3D models of the ear is introduced. It is feasible to create individualized 3D models using currently available consumer technology. The low barrier to entry raises the possibility for clinicians to incorporate 3D printing into various clinical applications.


Asunto(s)
Microtia Congénita/patología , Microtia Congénita/cirugía , Modelos Anatómicos , Modelación Específica para el Paciente , Procedimientos de Cirugía Plástica , Teléfono Inteligente , Reconocimiento Facial Automatizado , Microtia Congénita/diagnóstico por imagen , Humanos , Imagenología Tridimensional , Poliésteres , Impresión Tridimensional
9.
J Environ Qual ; 50(4): 955-966, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33908638

RESUMEN

Losses of phosphorus (P) from fertilized fields may result in degradation of water quality. Various initiatives are under evaluation to minimize water contamination, including the adoption of less soluble or coated P fertilizer formulations aiming to mitigate losses of P in runoff. Field-based rainfall simulators are traditionally used to evaluate P runoff, but using these is time consuming, labor intensive, and costly given the complex apparatus and analyses involved. We hypothesized that laboratory-based methods could be useful to evaluate the risk of P runoff from fertilizers. In order to identify a rapid, inexpensive, and efficient screening process, we compared two laboratory-scale measurements, one in water (based on electrical conductivity measurements) and one in soil (based on visualization of P diffusion in soil), with runoff results from field-, glasshouse-, and laboratory-based rainfall simulators, using coated soluble phosphate fertilizers. The laboratory-based methods assessing the P release rate in water and in soil correlated closely (r ≥ .96) with the losses of P obtained in the three rainfall simulators regardless of the type of coating or solubility of the fertilizer. The faster and inexpensive electrical conductivity and diffusion visualization methodologies were useful to rank the fertilizers by P release to runoff. Hence, these tools may be useful for screening fertilizer formulations with respect to their runoff risk.


Asunto(s)
Fertilizantes , Fósforo , Agricultura , Laboratorios , Lluvia , Movimientos del Agua
10.
Int J Pediatr Otorhinolaryngol ; 141: 110564, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33340984

RESUMEN

OBJECTIVE: To characterize the adherence of bone conduction hearing devices (BCHDs) for hearing management in children with unilateral congenital aural atresia (UCAA) in relation to the age of offer and fitting. BCHD Soft Bands help predict amplification benefits before surgery can be performed beginning around five years when both hearing and parental compliance reach stability. We hypothesized device compliance might decrease with age of fitting from lack of early acclimatization. METHODS: Retrospective case series of patients less than five years old at a tertiary pediatric center's microtia clinic database, born between 2014 and 2018 with UCAA. Adherence was assessed through electronic health record note documentation at less than 1 year, 1-2 years, and greater than 2 years from fitting. The ages at offer and fitting, along with the time from offer to fitting, were recorded. RESULTS: One hundred and eight patients with UCAA were identified, including 46 patients fit with a BCHD used for further analysis. Adherence rates at 1 year, 1-2 years, and greater than 2 years were 47.8%, 30%, and 43.5%, respectively. However, there was no significant association between age offered, age fit, or time from offer to fit and adherence at all time points. Also, there was no significant difference between ages at the time of BCHD offer for those who chose not to proceed with fitting (20.9 months) compared to the age of offer in patients that were subsequently fit (13.9 months). CONCLUSION: BCHD adherence in patients less than five years old may not be affected by the age offered or fit. The time between offer and fitting was also not associated with usage. BCHDs should be offered to UCAA patients regardless of age. Further investigation in this younger age group would help expand these findings.


Asunto(s)
Conducción Ósea , Audífonos , Niño , Preescolar , Oído , Pérdida Auditiva Conductiva/diagnóstico , Humanos , Lactante , Estudios Retrospectivos
11.
Sci Rep ; 10(1): 16963, 2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-33024241

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

12.
Chaos Solitons Fractals ; 139: 110088, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32834624

RESUMEN

The COVID-19 pandemic due to the SARS-CoV-2 coronavirus has directly impacted the public health and economy worldwide. To overcome this problem, countries have adopted different policies and non-pharmaceutical interventions for controlling the spread of the virus. This paper proposes the COVID-ABS, a new SEIR (Susceptible-Exposed-Infected-Recovered) agent-based model that aims to simulate the pandemic dynamics using a society of agents emulating people, business and government. Seven different scenarios of social distancing interventions were analyzed, with varying epidemiological and economic effects: (1) do nothing, (2) lockdown, (3) conditional lockdown, (4) vertical isolation, (5) partial isolation, (6) use of face masks, and (7) use of face masks together with 50% of adhesion to social isolation. In the impossibility of implementing scenarios with lockdown, which present the lowest number of deaths and highest impact on the economy, scenarios combining the use of face masks and partial isolation can be the more realistic for implementation in terms of social cooperation. The COVID-ABS model was implemented in Python programming language, with source code publicly available. The model can be easily extended to other societies by changing the input parameters, as well as allowing the creation of a multitude of other scenarios. Therefore, it is a useful tool to assist politicians and health authorities to plan their actions against the COVID-19 epidemic.

13.
Int J Pediatr Otorhinolaryngol ; 134: 110040, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32361150

RESUMEN

OBJECTIVE: To characterize the use of bone conduction hearing devices (BCHD) for hearing management in children with unilateral congenital aural atresia (CAA) at a tertiary pediatric center's microtia clinic while assessing challenges in acquisition. BCHD generally provides better audiologic outcomes than atresiaplasty in pediatric CAA. BCHD is formally recommended for only bilateral CAA, although literature has begun to show benefit in unilateral CAA. METHODS: A retrospective case series of patients born between 2014 and 2018 with unilateral microtia at an urban tertiary care children's hospital collected information on demographics, CAA laterality, hearing loss (HL) severity, management, and acquisition. Statistical analysis aided characterization of BCHD use. RESULTS: 131 patients (65% males) were included with a mean age of 3.5 years. 108 (82%) patients with unilateral microtia were used for further analysis, and right sided microtia was most common (67.6%). Of patients with auditory brain response (ABR) testing available, 70% demonstrated conductive HL, 16% mixed HL, 1% sensorineural HL, 6% no HL secondary to grade 1 microtia, and 7% were pending evaluation. Overall, 46 (42.6%) patients with unilateral microtia obtained a BCHD. 68.7% of those offered a BCHD after ABR opted for acquisition. The average length of time from offer to fit was about 6 months. CONCLUSION: Even with thorough consultation and follow up, less than half of the patients with unilateral CAA received a BCHD. Missed initial ABR appointments that lead to BCHD recommendation seem to be the greatest limiting factor, while demographics did not play a confounding role. Family education and future research on obstacles preventing BCHD use in unilateral CAA will help standardize management and improve hearing within this critical auditory period.


Asunto(s)
Conducción Ósea , Anomalías Congénitas/rehabilitación , Microtia Congénita/rehabilitación , Oído/anomalías , Audífonos , Pérdida Auditiva Conductiva/rehabilitación , Preescolar , Microtia Congénita/complicaciones , Potenciales Evocados Auditivos del Tronco Encefálico , Femenino , Pérdida Auditiva Conductiva/etiología , Pérdida Auditiva Sensorineural/complicaciones , Pérdida Auditiva Sensorineural/rehabilitación , Pruebas Auditivas , Humanos , Lactante , Masculino , Estudios Retrospectivos
14.
Otol Neurotol ; 41(4): 444-451, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32176122

RESUMEN

OBJECTIVE: To analyze outcomes of cochlear implantation (CI) in prelingually-deafened, late-implanted patients. DATA SOURCES: A search of MEDLINE and EMBASE was performed in February 2018 using SCOPUS for the intersection of "cochlear implant," "prelingual," "deaf," and "delay." REVIEW METHODS: Two independent reviewers screened all abstracts and titles for relevance, with conflicts resolved by either the primary or senior author. All articles passing this screen were subjected to a full-text review, during which the primary and senior author each examined manuscripts for inclusion and exclusion criteria. The Cochrane Risk of Bias Assessment Tool was used to assess potential sources of systematic error, and postoperative clinical outcomes were collected at the latest clinical follow-up. RESULTS: Twenty-eight articles were yielded in the final systematic review, accounting for 542 patients. For open-set sentence scores, 10 studies representing 240 patients showed an overall estimated improvement of 44.6% (95% CI: 38.0-51.2%). In terms of quality of life, studies generally showed improvement when looking at specific emotional, social, or hearing-specific domains, but not in global measures. Nonuser rates ranged from 0 to 9.5%. CONCLUSION: Despite performance that is generally poorer than what is generally seen in "traditional" candidates, prelingually-deafened, late-implanted (PL-LI) CI users can experience benefit in terms of both QOL and audiometric scores. The wide range of performance that is reported in the literature highlights the importance of careful patient counseling.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Sordera , Percepción del Habla , Sordera/cirugía , Humanos , Calidad de Vida , Resultado del Tratamiento
15.
RSC Adv ; 10(52): 31115-31122, 2020 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-35520669

RESUMEN

In this study, direct C-H photoarylation of pyrazine with aryldiazonium salts under visible-light irradiation (blue-LEDs) is described, and additional examples including photoarylations of pyrimidine and pyridazine are also covered. The corresponding aryl-diazines were prepared in yields up to 84% only by mixing and irradiating the reaction with no need for an additional photocatalyst. We demonstrate the efficacy of this protocol by the scope with electron-donor, -neutral, and -withdrawing groups attached at the ortho, meta, and para positions of the aryldiazonium salts; the results are better than those reported for ruthenium-complex mediated photoarylations. Additionally, we demonstrate the robustness of this methodology with a 5 mmol scaled-up experiment. Mechanistic studies were carried out giving support to the proposal of a photocatalyzed approach by an electron donor-acceptor (EDA) complex, also highlighting the crucial role that solvents play in the formation of the EDA complex.

16.
Am J Med Genet A ; 182(4): 697-704, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31876392

RESUMEN

Hearing loss (HL) is an extra-skeletal manifestation of the connective tissue disorder osteogenesis imperfecta (OI). Systematic evaluation of the prevalence and characteristics of HL in COL1A1/COL1A2-related OI will contribute to a better clinical management of individuals with OI. We collected and analyzed pure-tone audiometry data from 312 individuals with OI who were enrolled in the Linked Clinical Research Centers and the Brittle Bone Disorders Consortium. The prevalence, type, and severity of HL in COL1A1/COL1A2-related OI are reported. We show that the prevalence of HL in OI is 28% and increased with age in Type I OI but not in Types III and IV. Individuals with OI Types III and IV are at a higher risk to develop HL in the first decade of life when compared to OI Type I. We also show that the prevalence of SNHL is higher in females with OI compared to males. This study reveals new insights regarding prevalence of HL in OI including a lower general prevalence of HL in COL1A1/COL1A2-related OI than previously reported (28.3 vs. 65%) and high prevalence of SNHL in females. Our data support the need in early routine hearing evaluation in all types of OI that can be adjusted to the severity of the skeletal disease.


Asunto(s)
Colágeno Tipo I/genética , Pérdida Auditiva/epidemiología , Mutación , Osteogénesis Imperfecta/fisiopatología , Adolescente , Adulto , Niño , Cadena alfa 1 del Colágeno Tipo I , Femenino , Genotipo , Pérdida Auditiva/genética , Pérdida Auditiva/patología , Humanos , Masculino , Persona de Mediana Edad , América del Norte/epidemiología , Fenotipo , Adulto Joven
17.
Sci Rep ; 9(1): 19520, 2019 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-31863023

RESUMEN

Increasing the selenium (Se) concentration of staple crops by fertilization is a valuable pathway to increase Se in the human diet, thus preventing Se deficiency. A pot trial was set up to investigate whether the application of 3.33 µg kg-1 of Se (equivalent to 10 g ha-1) to wheat can be made more efficient by its co-application with macronutrient carriers, either to the soil or to the leaves. In the soil, Se was applied either on its own (selenate only) or as a granular, Se-enriched macronutrient fertilizer supplying nitrogen, phosphorus, potassium or sulfur. Selenium was also applied to leaves at head emergence with, or without, 2% w/v N fertilizers. With grain Se concentrations varying from 0.13-0.84 mg kg-1, soil application of selenate-only was 2-15 times more effective than granular Se-enriched macronutrient fertilizers in raising grain Se concentrations. Co-application of foliar Se with an N carrier doubled the Se concentration in wheat grains compared to the application of foliar Se on its own, the majority of which was in the highly bioavailable selenomethionine fraction. Results from this study demonstrate the possibility of improving the efficacy of Se fertilizers, which could enrich crops with Se without additional application costs in the field.


Asunto(s)
Fertilizantes , Selenio/metabolismo , Triticum/metabolismo , Biofortificación , Nitrógeno/metabolismo , Ósmosis , Fósforo/metabolismo , Plantones/metabolismo , Azufre/metabolismo
18.
J Org Chem ; 84(16): 10459-10471, 2019 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-31322352

RESUMEN

A metal-free methodology for the photoarylation of pyridines, in water, is described giving 2 and 4-arylated-pyridines in yields up to 96%. The scope of the aryldiazonium salts is presented showing important results depending on the nature and position of the substituent group in the diazonium salt, that is, electron-donating or electron-withdrawing in the ortho, meta, or para positions. Further heteroaromatics were also successfully photoarylated. Mechanistic studies and comparison between our methodology and similar metal-catalyzed procedures are presented, suggesting the occurrence of a visible-light EDA complex which generates the aryl radical with no need for an additional photocatalyst.

19.
Pesqui. vet. bras ; 38(7): 1358-1364, July 2018. tab, ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-976437

RESUMEN

This study evalueted the prevalence of Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli in milk samples from 257 goats (513 half-udders) and ten bulk tanks, from ten dairy goat farms of São Paulo State, Brazil, by multiplex-PCR. The samples were screened by microbiological culture (gold-standard), and tested by different multiplex-PCR protocols for the detection of each bacterium. A total of 178 half-udders resulted positive by microbiological culture, with coagulase-negative staphylococci (70%), S. aureus (13.5%), S. intermedius (7.9%), and Enterobacteriaceae (4%) the prevalent pathogens. In other way, multiplex-PCR detected 173 pathogens in 151/523 (28.9%; CI95% 25.2-32.9%) milk samples 144/513 (28.1%) half-udders and 7/10 (70%) bulk tanks, with E. coli (86/162, 51.9%) and S. aureus (50/162, 30.9%) the prevalent ones in half-udders, and S. aureus (6/10, 60%) and E. coli (4/5, 36.4%) in bulk tanks. Multiplex-PCR showed a high performance for the detection of three bacteria at a time in mastitic goat milk direct from half-udders or bulk tanks. Thus, this multiplex-PCR protocol proved to be an adequate tool for the identification of the most common mastitis pathogens, independent of their phenotypic characteristics in the diagnosis of clinical mastitis in goats, allowing a continuous and better vigilance and monitoring the herd, being included in quality programs.(AU)


Este estudo avaliou por multiplex-PCR a prevalência de Staphylococcus aureus, Streptococcus agalactiae e Escherichia coli em amostras de leite de 257 caprinos (513 tetos) e dez tanques de expansão, em dez fazendas leiteiras do estado de São Paulo, Brasil. As amostras foram triadas por cultura microbiológica (padrão-uro) e testadas por diferentes protocolos multiplex-PCR para a detecção de cada bactéria. Um total de 178 amostras de leite foram positivos na cultura microbiológica, com estafilococos coagulase-negativos (70%), S. aureus (13,5%), S. intermedius (7,9%) e Enterobacteriaceae (4%) como patógenos prevalentes. Por outro lado, a PCR multiplex detectou 173 patógenos em 151/523 (28,9%, IC95% 25,2-32,9%) amostras de leite, 144/513 (28,1%) amostras de tetos e 7/10 (70%) em tanques de expansão, E. coli (86/162, 51,9%) e S. aureus (50/162, 30,9%) foram identificados nas amostras de tetos e S. aureus (6/10, 60%) e E. coli (4/5, 36,4%) em tanques expansão. Multiplex-PCR mostrou um alto desempenho para a detecção das três bactérias em leite de cabra com mastite ou em tanques de expansão. Dessa forma, este protocolo multiplex-PCR provou ser uma ferramenta adequada para a identificação dos patógenos mais comuns da mastite, independentemente de suas características fenotípicas no diagnóstico de mastite clínica em caprinos, permitindo uma vigilância contínua e melhor acompanhamento do rebanho, sendo incluído em programas de qualidade.(AU)


Asunto(s)
Animales , Staphylococcus aureus/clasificación , Streptococcus agalactiae/clasificación , Rumiantes/anomalías , Escherichia coli/clasificación
20.
J Environ Qual ; 47(2): 371-377, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29634800

RESUMEN

The enrichment of P in surface waters has been linked to P runoff from agricultural fields amended with fertilizers. Novel slow-release mineral fertilizers, such as struvite and P-exchanged layered double hydroxides (LDHs), have received increasing attention for P recycling from waste streams, and these fertilizers may potentially reduce the risk of runoff losses. Here, a rainfall simulation experiment was performed to evaluate P runoff associated with the application of recycled slow-release fertilizers relative to that of a soluble fertilizer. Monoammonium phosphate (MAP), struvite, and LDH granular fertilizers were broadcasted at equal total P doses on soil packed in trays (5% slope) and covered with perennial ryegrass ( L.). Four rainfall simulation events of 30 min were performed at 1, 5, 15, and 30 d after the fertilizer application. Runoff water from the trays was collected, filtered, and analyzed for dissolved P. For the MAP treatment, P runoff losses were high in the first two rain events and leveled off in later rain events. In total, 42% of the applied P in the MAP treatment was lost due to runoff. In the slow-release fertilizer treatments, P runoff losses were limited to 1.9 (struvite) and 2.4% (LDH) of the applied doses and were more similar over the different rain events. The use of these novel P fertilizer forms could be beneficial in areas with a high risk of surface water eutrophication and a history of intensive fertilization.


Asunto(s)
Agricultura , Fertilizantes , Fósforo/química , Movimientos del Agua , Hidróxidos , Lluvia , Estruvita
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