Deciphering the origin of the first steps in the degradation of azo dyes: a computational study.

Azo dyes find applications across various sectors including food, pharmaceuticals, cosmetics, printing, and textiles. The contaminating effects of dyes on aquatic environments arise from toxic effects caused by their long-term presence in the environment, buildup in sediments, particularly in aquatic species, degradation of pollutants into mutagenic or mutagenic compounds, and low aerobic biodegradability. Therefore, we theoretically propose the first steps of the degradation of azo dyes based on the interaction of hydroperoxyl radical (•OOH) with the dye. This interaction is studied by the OC and ON mechanisms in three azo dyes: azobenzene (AB), disperse orange 3 (DO3), and disperse red 1 (DR1). Rate constants calculated at several temperatures show a preference for the OC mechanism in all the dyes with lower activation energies than the ON mechanism. The optical properties were calculated and because the dye-•OOH systems are open shell, to verify the validity of the results, a study of the spin contamination of the ground [Formula: see text] and excited states [Formula: see text] was previously performed. Most of the excited states calculated are acceptable as doublet states. The absorption spectra of the dye-•OOH systems show a decrease in the intensity of the bands compared to the isolated dyes and the appearance of a new band of the type π → π* at a longer wavelength in the visible region, achieving up to 868 nm. This demonstrates that the reaction with the •OOH radical could be a good alternative for the degradation of the azo dyes.

A simple method to estimate the mean number of lipophilic molecules on nanoparticle surfaces by fluorescence measurements.

Measurements of fluorescence intensity of the hydrophobic pyridinium salt (DTPSH) remaining in the organic phase after partition experiments in the DCM/H2O system allowed an approximate method to be developed to estimate the mean number of molecules (N = 942) on the surface of 22.8 nm gold nanoparticles and the separation (1.89 nm) between these organic molecules. This protocol is based on the ability that the organic molecules possess to coat the surface of the nanoparticle, which can migrate from the organic to the aqueous phase as a result of the driving force of the strong binding of sulfur to gold. To validate our estimation, we used a projection of the results obtained by Wales and Ulker to solve the Thomson problem, a mathematicians' challenge, used as a model to calculate the mean distance (1.82 nm) separating particles on the surface, in excellent agreement with the results obtained by our method. The quality of results, the simplicity of calculations, the low fluorescence detection limit, and the inexpensive materials, recommend this procedure for rapid estimates of the mean number of molecules on the surface of nanoparticles.

TiO2 Photocatalyzed Degradation of the Azo Dye Disperse Red 1 in Aqueous Micellar Environments†.

The photoinduced degradation of the azo dye Disperse Red 1 was studied in a microheterogeneous system comprising titanium oxide (TiO2 ) and sodium dodecyl sulfate, exposed to UV light. Degussa P25, Anatase and TiO2 synthesized in acidic conditions were supported on raschig rings. The TiO2 photocatalyzed degradation is enhanced in the vicinity of the surfactant critical micelle value. Further increase on the surfactant concentration leads to a loss in photodegradation performance up to values equivalent to that observed without surfactant. Surfactant influence can be explained by two different phenomena taking place. The increasing concentration of surfactant leads to an increase in micellar concentration, inducing the incorporation of the dye to the hydrophobic moiety of the micelles, rendering the hydroxyl radical unable to interact with the dye. Similarly, the increased concentration of micelles at the photocatalyst/water interface might lead to a decrease in the number of active sites on the TiO2 surface able to either generate reactive species and/or interact with de dye molecules. Additives such as H2 O2 , NaCl, Na2 SO4, and Na2 CO3 are able to override the influence of the surfactant both positively and negatively, being the final outcome of the influence highly dependent on the crystalline form of the TiO2 photocatalyst.

Validation of a machine learning algorithm for early severe sepsis prediction: a retrospective study predicting severe sepsis up to 48 h in advance using a diverse dataset from 461 US hospitals.

BACKGROUND: Severe sepsis and septic shock are among the leading causes of death in the United States and sepsis remains one of the most expensive conditions to diagnose and treat. Accurate early diagnosis and treatment can reduce the risk of adverse patient outcomes, but the efficacy of traditional rule-based screening methods is limited. The purpose of this study was to develop and validate a machine learning algorithm (MLA) for severe sepsis prediction up to 48 h before onset using a diverse patient dataset. METHODS: Retrospective analysis was performed on datasets composed of de-identified electronic health records collected between 2001 and 2017, including 510,497 inpatient and emergency encounters from 461 health centers collected between 2001 and 2015, and 20,647 inpatient and emergency encounters collected in 2017 from a community hospital. MLA performance was compared to commonly used disease severity scoring systems and was evaluated at 0, 4, 6, 12, 24, and 48 h prior to severe sepsis onset. RESULTS: 270,438 patients were included in analysis. At time of onset, the MLA demonstrated an AUROC of 0.931 (95% CI 0.914, 0.948) and a diagnostic odds ratio (DOR) of 53.105 on a testing dataset, exceeding MEWS (0.725, P < .001; DOR 4.358), SOFA (0.716; P < .001; DOR 3.720), and SIRS (0.655; P < .001; DOR 3.290). For prediction 48 h prior to onset, the MLA achieved an AUROC of 0.827 (95% CI 0.806, 0.848) on a testing dataset. On an external validation dataset, the MLA achieved an AUROC of 0.948 (95% CI 0.942, 0.954) at the time of onset, and 0.752 at 48 h prior to onset. CONCLUSIONS: The MLA accurately predicts severe sepsis onset up to 48 h in advance using only readily available vital signs extracted from the existing patient electronic health records. Relevant implications for clinical practice include improved patient outcomes from early severe sepsis detection and treatment.

Effect of a sepsis prediction algorithm on patient mortality, length of stay and readmission: a prospective multicentre clinical outcomes evaluation of real-world patient data from US hospitals.

BACKGROUND: Severe sepsis and septic shock are among the leading causes of death in the USA. While early prediction of severe sepsis can reduce adverse patient outcomes, sepsis remains one of the most expensive conditions to diagnose and treat. OBJECTIVE: The purpose of this study was to evaluate the effect of a machine learning algorithm for severe sepsis prediction on in-hospital mortality, hospital length of stay and 30-day readmission. DESIGN: Prospective clinical outcomes evaluation. SETTING: Evaluation was performed on a multiyear, multicentre clinical data set of real-world data containing 75 147 patient encounters from nine hospitals across the continental USA, ranging from community hospitals to large academic medical centres. PARTICIPANTS: Analyses were performed for 17 758 adult patients who met two or more systemic inflammatory response syndrome criteria at any point during their stay ('sepsis-related' patients). INTERVENTIONS: Machine learning algorithm for severe sepsis prediction. OUTCOME MEASURES: In-hospital mortality, length of stay and 30-day readmission rates. RESULTS: Hospitals saw an average 39.5% reduction of in-hospital mortality, a 32.3% reduction in hospital length of stay and a 22.7% reduction in 30-day readmission rate for sepsis-related patient stays when using the machine learning algorithm in clinical outcomes analysis. CONCLUSIONS: Reductions of in-hospital mortality, hospital length of stay and 30-day readmissions were observed in real-world clinical use of the machine learning-based algorithm. The predictive algorithm may be successfully used to improve sepsis-related outcomes in live clinical settings. TRIAL REGISTRATION NUMBER: NCT03960203.

Photocatalytic Degradation of Aqueous Rhodamine 6G Using Supported TiO2 Catalysts. A Model for the Removal of Organic Contaminants From Aqueous Samples.

As a model for the removal of complex organic contaminants from industrial water effluents, the heterogeneous photocatalytic degradation of Rhodamin 6G was studied using TiO2-derived catalysts, incorporated in water as suspension as well as supported in raschig rings. UV and Visible light were tested for the photo-degradation process. TiO2 catalysts were synthesized following acid synthesis methodology and compared against commercial TiO2 catalyst samples (Degussa P25 and Anatase). The bandgap (Eg) of the TiO2 catalysts was determined, were values of 2.97 and 2.98 eV were obtained for the material obtained using acid and basic conditions, respectively, and 3.02 eV for Degussa P25 and 3.18 eV for anatase commercial TiO2 samples. Raschig rings-supported TiO2 catalysts display a good photocatalytic performance when compared to equivalent amounts of TiO2 in aqueous suspension, even though a large surface area of TiO2 material is lost upon support. This is particularly evident by taking into account that the characteristics (XRD, RD, Eg) and observed photodegradative performance of the synthesized catalysts are in good agreement with the commercial TiO2 samples, and that the RH6G photodegradation differences observed with the light sources considered are minimal in the presence of TiO2 catalysts. The presence of additives induce changes in the kinetics and efficiency of the TiO2-catalyzed photodegradation of Rh6G, particularly when white light is used in the process, pointing toward a complex phenomenon, however the stability of the supported photocatalytic systems is acceptable in the presence of the studied additives. In line with this, the magnitude of the chemical oxygen demand, indicates that, besides the different complex photophysical processes taking place, the endproducts of the considered photocatalytic systems appears to be similar.

Copper Recovery From Ammonia Solutions Through Electro-Electrodialysis (EED).

Alkaline leaching with highly selective ammoniacal complexing agents is an interesting alternative for the treatment of copper concentrates. This treatment is beneficial for copper recovery because it allows the formation of soluble amines complexes, with cupric tetramine (  Cu ( NH 3 ) 4 2 + ) being the most stable. In order to suppress the unit operation of solvent extraction (SX) and move directly to the electrochemical process, an electro-electrodialysis (EED) process using ion exchange membranes to obtain copper is proposed. The study contemplates the operation with synthetic ammonia solutions containing copper at different concentrations and current density under standard conditions of pressure and temperature. The presented data demonstrate that the concentration of copper in the solution and the excess of ammonia are inversely related to the efficiency of the current and the voltage of the cell, whereas an increase in current density causes an increase in current efficiency, contrary to what happens in sulfuric systems.

Epidemiology of abusive head trauma in West Virginia children <24 months: 2000-2010.

BACKGROUND: Few states have published statewide epidemiology of abusive head trauma (AHT). OBJECTIVE: To examine the statewide epidemiology of AHT in West Virginia (WV), with the primary objective of establishing AHT incidence for comparison to national data, and to use as a baseline for comparison to incidence post-implementation of a statewide AHT prevention program. PARTICIPANTS AND SETTING: AHT cases in children less than 2 years old were identified from the 3 tertiary pediatric centers in WV. METHODS: Cases were identified by using ICD-9 codes for initially identifying those with injuries which might be consistent with AHT, followed by medical record review to determine which of these met the criteria for inclusion as a case. Medical examiner data was used to find additional cases of AHT. Using the number of cases identified along with relevant census data, incidence of AHT was calculated. RESULTS: There were 120 cases of AHT treated in WV hospitals from 2000 to 2010, 100 of which were WV residents. The incidence was 36.1/100,000 children <1 year of age and was 21.9 cases per 100,000 children <2 years of age. Incidence in infants increased during the latter years (2006-2010) of the study to 51.8/100,000 compared to the incidence during 2000-2005, which was 24.0/100,000 (p < .01). CONCLUSIONS: Compared to US national, state and regional figures, the WV incidence of AHT was among the highest. In addition, the incidence of AHT increased significantly over the study period. Possible factors contributing to the rise in incidence are discussed.

Tiroidectomía endoscópica transaxilar: un abordaje más que ofrecer a nuestros pacientes / Transaxillary endoscopic thyroidectomy: Another approach to offer our patients

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Reaction Kinetics of Phenolic Antioxidants toward Photoinduced Pyranine Free Radicals in Biological Models.

8-Hydroxy-1,3,6-pyrenetrisulfonic acid (pyranine, PyOH) free radicals were induced by laser excitation at visible wavelengths (470 nm). The photochemical process involves photoelectron ejection from PyO- to produce PyO• and PyO•- with maxima absorption at 450 and 510 nm, respectively. The kinetic rate constants for phenolic antioxidants with PyO•, determined by nanosecond time-resolved spectroscopy, were largely reliant on the ionic strength depending on the antioxidant phenol/phenolate dissociation constant. Further, the apparent rate constant measured in the presence of Triton X100 micelles was influenced by the antioxidant partition between the micelle and the dispersant aqueous media but limited by its exit rates from the micelle. Similarly, the rate reaction between ascorbic acid and PyO• was markedly affected by the presence of human serum albumin responding to the dynamic of the ascorbic acid binding to the protein.

A Metal-Free, Nonconjugated Polymer for Solar Photocatalysis.

Heterogeneous catalysts that can absorb light over the solar range are ideal for green photocatalysis. Recently, attention has been directed towards the generation of novel solar-light photocatalysts, in particular, metal-free polymers. Herein, it is demonstrated that a metal-free, nonconjugated, anthraquinone-based copolymer (poly[1,4-diamine-9,10-dioxoanthracene-alt-(benzene-1,4-dioic acid)] (COP)) with a strong absorption in the visible region is effective as a sunlight heterogeneous photocatalyst. As a proof of concept, it has been used to mineralize 2,5-dichlorophenol (2,5-DCP) in water under air and sunlight irradiation. The photocatalytic efficiency of COP compares well with that of TiO2 -P25 when the reaction is carried out in a solar photoreactor in acid medium. Steady-state and time-resolved (absorption and emission) studies performed on COP suspended in 6:4 DMF/H2 O have provided valuable information about the COP species generated under different pH conditions. Steady-state absorption and fluorescence data are consistent with the existence of a tautomeric equilibrium between the 9,10-keto and 1,10-iminoketo quinoid forms for the anthraquinone in the ground state. Moreover, in basic media, transient absorption measurements showed the presence of two bands ascribed to the tautomeric triplet excited states, whereas only one of the triplets was observed in acid medium. A mechanism for the photocatalyzed degradation of 2,5-DCP by COP is proposed on the basis of these observations.

Acute ischemic stroke in a 19 month old following minor head trauma: case report and review of the literature.

Minor head trauma is a very rare cause of ischemic stroke in the pediatric population. We describe a nineteen month old patient who developed left hemiparesis and subsequently left facial palsy after a fall. MRI of the brain showed hypodensities in the basal ganglia, internal capsule and caudate nucleus consistent with stroke. Echocardiogram and MRA were normal. Hypercoaguable work up showed that the patient was a carrier for a single MTHFR gene. The patient was treated conservatively. On follow up two weeks later his facial palsy had resolved and strength in the extremities improved. Although a rare condition awareness about this is necessary as there can be considerable delay in its recognition.

Enhanced catalytic electrochemical reduction of dissolved oxygen with ultraclean cucurbituril[7]-capped gold nanoparticles.

Gold nanoparticles capped with cucurbituril[7] have been prepared in the absence of metallic cations and organic ligands. Remarkably, these nanohybrids encapsulate dissolved oxygen and are highly active in electrochemical reduction. The effect of the presence of sodium and ammonium salts on this catalysed process is also analysed.

Coumarin 314 free radical cation: formation, properties, and reactivity toward phenolic antioxidants.

We have explored the photogeneration of the coumarin 314 radical cation by using nanosecond laser excitation at wavelengths longer than 400 nm in benzene, acetonitrile, dichloromethane, and aqueous media. In addition, time-resolved absorption spectroscopy measurements allowed detection of the triplet excited state of coumarin 314 (C(314)) with a maximum absorption at 550 nm in benzene. The triplet excited state has a lifetime of 90 µs in benzene. It is readily quenched by oxygen (k(q) = 5.0 × 10(9) M(-1) s(-1)). From triplet-triplet energy transfer quenching experiments, it is shown that the energy of this triplet excited state is higher than 35 kcal/mol, in accord with the relatively large singlet oxygen quantum yield (Φ(Δ) = 0.25). However, in aqueous media, the coumarin triplet was no longer observed, and instead of that, a long-lived (160 µs in air-equilibrated solutions) free radical cation with a maximum absorbance at 370 nm was detected. The free radical cation generation, which has a quantum yield of 0.2, occurs by electron photoejection. Moreover, density functional theory (DFT) calculations indicate that at least 40% of the electronic density is placed on the nitrogen atom in aqueous media, which explains its lack of reactivity toward oxygen. On the other hand, rate constant values close to the diffusion rate limit in water (>10(9) M(-1) s(-1)) were found for the quenching of the C(314) free radical cation by phenolic antioxidants. The results have been interpreted by an electron-transfer reaction between the phenolic antioxidant and the radical cation where ion pair formation could be involved.

A comparative photophysical and photochemical study of nitropyrene isomers occurring in the environment.

Ground state absorption, first excited-singlet state, and properties of reactive intermediates of mononitropyrene isomers encountered in the atmospheric aerosol have been studied under different conditions that could mimic the environment. The nitro group can present different orientations relative to the pyrene ring depending on its geometric location and could induce differences in the photochemistry of the isomers. The 2-NO(2)Py isomer has the largest red shift and lowest oscillator strength in the UV-visible band associated with the nitro group. The isomers show very low fluorescence yields (10(-3)-10(-4)). Only 1-NO(2)Py and 4-NO(2)Py have phosphorescence emission (Φ(p) ≈ 10(-4)), indicating that the lowest triplet state decays mainly through effective radiationless channels. Laser photolysis produces a low-lying triplet state (τ(T) = 10(-5)-10(-6) s), a long-lived pyrenoxy radical, and a PyNO(2)H radical in solvents in which the triplet can abstract a hydrogen atom. Similar triplet yields were calculated (0.1-0.6) for the isomers, while significant differences in the relative yield of the long-lived species were determined. Differences in the quenching rate constants of the triplet by water and phenols suggest a strong hydrogen-bond interaction with the nitro group in the C-2 position, which provides for radiationless deactivation routes.

Rediseño de la sala de control de tráfico del ferrocarril de Antofagasta-Bolivia: diseño acústico y mobiliario / Redesign of the traffic control room of the Antofagasta -Bolivia railroad company: acoustic and furniture design

El Departamento de Tráfico del Ferrocarril de Antofagasta a Bolivia se encarga de las comunicaciones de todo el sistema de la red ferroviaria.El cálculo predictivo de los elementos acústicos permite valorar cuál es el mejor material para la sala de control en su fase de diseño, permitiendo aquello ahorrar importantes costos. El mobiliario en este tipo de trabajo es clave dado que es en la sala de control donde se desarrollan las operaciones. El presente artículo propone la implementación de nuevos elementos que generen un impacto directo en la baja de los costos por concepto de ausentismo, seguridad laboral y calidad de vida de las personas.

The Traffic Department of the Antofagasta-Bolivia Railroad Company deals with communications among all the railroad network system. Predictive calculations of acoustic elements allow us to assess the best material for the control room in the design phase, and thus making costs saving easier. The furniture in this kind of job is crucial because all operations are carried out in the control room. This article suggests the implementation of new elements that create a direct impact on costs related to absenteeism, occupational safety and quality of life.

Photophysics and photochemistry of 1-nitropyrene.

1-Nitropyrene (1NPy) is the most abundant nitropolycyclic aromatic contaminant encountered in diesel exhausts. Understanding its photochemistry is important because of its carcinogenic and mutagenic properties, and potential phototransformations into biologically active products. We have studied the photophysics and photochemistry of 1NPy in solvents that could mimic the microenvironments in which it can be found in the atmospheric aerosol, using nanosecond laser flash photolysis, and conventional absorption and fluorescence techniques. Significant interactions between 1NPy and solvent molecules are demonstrated from the changes in the magnitude of the molar absorption coefficient, bandwidth at half-peak, oscillator strengths, absorption maxima, Stokes shifts, and fluorescence yield. The latter are very low (10 (-4)), increasing slightly with solvent polarity. Low temperature phosphorescence and room temperature transient absorption spectra demonstrate the presence of a low energy (3)(pi,pi*) triplet state, which decays with rate constants on the order of 10 (4)-10 (5) s (-1). This state is effectively quenched by known triplet quenchers at diffusion control rates. Intersystem crossing yields of 0.40-0.60 were determined. A long-lived absorption, which grows within the laser pulse, and simultaneously with the triplet state, presents a maximum absorption in the wavelength region of 420-440 nm. Its initial yield and lifetime depend on the solvent polarity. This species is assigned to the pyrenoxy radical that decays following a pseudo-first-order process by abstracting a hydrogen atom from the solvent to form one the major photoproducts, 1-hydroxypyrene. The (3)(pi,pi*) state reacts readily ( k approximately 10 (7)-10 (9) M (-1) s (-1)) with substances with hydrogen donor abilities encountered in the aerosol, forming a protonated radical that presents an absorption band with maximum at 420 nm.

Periosteal margin in soft-tissue sarcoma.

BACKGROUND: Soft-tissue sarcomas frequently rest in contact with bone. The purpose of the study was to evaluate the risk of local recurrence for sarcomas adjacent to bone and to determine whether the periosteum provides an adequate margin of resection. METHODS: Fifty patients with soft-tissue sarcomas abutting bone were treated at a single institution between 1990 and 2004. All patients had high-grade, T2 (>5 cm), nonmetastatic disease in the lower extremity. Bone contact was verified by preoperative magnetic resonance imaging (MRI) and/or computed tomography (CT) scans. Forty-three of 50 patients received preoperative radiation with a mean dose of 50 Gy. In 11 cases a composite resection of bone and soft tissue was performed. In 39 cases the excision involved only soft tissue. RESULTS: True bone invasion was verified by histopathologic examination in 3 of 50 cases (6%). Local recurrence in the soft tissues developed in 8 of 50 (16%) patients. In no case did the recurrence involve destruction of cortical bone or erosion into bone. The recurrent tumor resided against the region of previous bone contact in 1 of 8 cases. There was no statistically significant difference in local recurrence between patients who had composite bone resection and patients who had soft-tissue resection only (P = .87). CONCLUSIONS: Relatively few sarcomas are able to penetrate cortical bone. Composite bone and soft-tissue resections are indicated primarily for frank bone invasion. In the absence of this, the periosteum is an adequate surgical margin for sarcomas treated with wide excision and radiation.

Glosario español-inglés de interrogantes y frases útiles para la entrevista médica a pacientes con trastornos cardio-respiratorios / English-Spanish Glossary of questions and useful phrases to be used in the medical interview with patients suffering from cardiorespiratory disorders

Con el objetivo de facilitar la comunicación de los médicos de habla hispana con pacientes de habla inglesa, se ha desarrollado la segunda parte de una guía-glosario para el examen de un paciente que presenta trastornos cardio-respiratorios. Dicho glosario, conformado por 11 acápites y unas 150 interrogantes y frases útiles, constituye una herramienta eficaz para lograr un rápido dominio del vocabulario básico necesario para la comunicación médico-paciente en esta área clínica(AU)

Glosario español-inglés de interrogantes y frases útiles para la entrevista médica a pacientes con trastornos cardio-respiratorios / English-Spanish Glossary of questions and useful phrases to be used in the medical interview with patients suffering from cardiorespiratory disorders

Con el objetivo de facilitar la comunicación de los médicos de habla hispana con pacientes de habla inglesa, se ha desarrollado la segunda parte de una guía-glosario para el examen de un paciente que presenta trastornos cardio-respiratorios. Dicho glosario, conformado por 11 acápites y unas 150 interrogantes y frases útiles, constituye una herramienta eficaz para lograr un rápido dominio del vocabulario básico necesario para la comunicación médico-paciente en esta área clínica