Removal of Mo(VI), Pb(II), and Cu(II) from wastewater using electrospun cellulose acetate/chitosan biopolymer fibers.

Environmentally friendly polymers such as cellulose acetate (CA) and chitosan (CS) were used to obtain electrospun fibers for Cu2+, Pb2+, and Mo6+ capture. The solvents dichloromethane (DCM) and dimethylformamide (DMF) allowed the development of a surface area of 148 m2 g-1 for CA fibers and 113 m2 g-1 for cellulose acetate/chitosan (CA/CS) fibers. The fibers were characterized by IR-DRIFT, SEM, TEM, CO2 sorption isotherms at 273 K, Hg porosimetry, TGA, stress-strain tests, and XPS. The CA/CS fibers had a higher adsorption capacity than CA fibers without affecting their physicochemical properties. The capture capacity reached 102 mg g-1 for Cu2+, 49.3 mg g-1 for Pb2+, and 13.1 mg g-1 for Mo6+. Furthermore, optimal pH, adsorption times qt, and C0 were studied for the evaluation of kinetic models and adsorption isotherms. Finally, a proposal for adsorbate-adsorbent interactions is presented as a possible capture mechanism where, in the case of Mo6+, a computational study is presented. The results demonstrate the potential to evaluate the fibers in tailings wastewater from copper mining.

The effects of prehospital TXA on mortality and neurologic outcomes in patients with traumatic intracranial hemorrhage: a subgroup analysis from the prehospital TXA for TBI trial.

BACKGROUND: In the Prehospital Tranexamic Acid (TXA) for TBI Trial, TXA administered within two hours of injury in the out-of-hospital setting did not reduce mortality in all patients with moderate/severe traumatic brain injury (TBI). We examined the association between TXA dosing arms, neurologic outcome, and mortality in patients with intracranial hemorrhage (ICH) on computed tomography (CT). METHODS: This was a secondary analysis of the Prehospital Tranexamic Acid for TBI Trial (ClinicalTrials.gov [NCT01990768]) that randomized adults with moderate/severe TBI (Glasgow Coma Scale<13) and systolic blood pressure > =90 mmHg within two hours of injury to a 2-gram out-of-hospital TXA bolus followed by an in-hospital saline infusion, a 1-gram out-of-hospital TXA bolus/1-gram in-hospital TXA infusion, or an out-of-hospital saline bolus/in-hospital saline infusion (placebo). This analysis included the subgroup with ICH on initial CT. Primary outcomes included 28-day mortality, 6-month Glasgow Outcome Scale-Extended (GOSE) < = 4, and 6-month Disability Rating Scale (DRS). Outcomes were modeled using linear regression with robust standard errors. RESULTS: The primary trial included 966 patients. Among 541 participants with ICH, 28-day mortality was lower in the 2-gram TXA bolus group (17%) compared to the other two groups (1-gram bolus/1-gram infusion 26%, placebo 27%). The estimated adjusted difference between the 2-gram bolus and placebo groups was -8·5 percentage points (95% CI, -15.9 to -1.0) and between the 2-gram bolus and 1-gram bolus/1-gram infusion groups was -10.2 percentage points (95% CI, -17.6 to -2.9). DRS at 6 months was lower in the 2-gram TXA bolus group than the 1-gram bolus/1-gram infusion (estimated difference -2.1 [95% CI, -4.2 to -0.02]) and placebo groups (-2.2 [95% CI, -4.3, -0.2]). Six-month GOSE did not differ among groups. CONCLUSIONS: A 2-gram out-of-hospital TXA bolus in patients with moderate/severe TBI and ICH resulted in lower 28-day mortality and lower 6-month DRS than placebo and standard TXA dosing. LEVEL OF EVIDENCE: Therapeutic/Care Management, Level II.

Interactions and reactivity in crystalline intermediates of mechanochemical cyclorhodation reactions.

There is experimental evidence that solid mixtures of the rhodium dimer [Cp*RhCl2]2 and benzo[h] quinoline (BHQ) produce two different polymorphic molecular cocrystals called 4α and 4ß under ball milling conditions. The addition of NaOAc to the mixture leads to the formation of the rhodacycle [Cp*Rh-(BHQ)Cl], where the central Rh atom retains its tetracoordinate character. Isolate 4ß reacts with NaOAc leading to the same rhodacycle while isolate 4α does not under the same conditions. We show that the puzzling difference in reactivity between the two cocrystals can be traced back to fundamental aspects of the intermolecular interactions between the BHQ and [Cp*RhCl2]2 fragments in the crystalline environment. To support this view, we report a number of descriptors of the nature and strength of chemical bonds and intermolecular interactions in the extended solids and in a cluster model. We calculate formal quantum mechanical descriptors based on electronic structure, electron density, and binding and interaction energies including an energy decomposition analysis. Without exception, all descriptors point to 4ß being a transient structure higher in energy than 4α with larger local and global electrophilic and nucleophilic powers, a more favorable spatial and energetic distribution of the frontier orbitals, and a more fragile crystal structure.

Melatonin Exerts Prominent, Differential Epidermal and Dermal Anti-Aging Properties in Aged Human Eyelid Skin Ex Vivo.

Human skin aging is associated with functional deterioration on multiple levels of physiology, necessitating the development of effective skin senotherapeutics. The well-tolerated neurohormone melatonin unfolds anti-aging properties in vitro and in vivo, but it remains unclear whether these effects translate to aged human skin ex vivo. We tested this in organ-cultured, full-thickness human eyelid skin (5-6 donors; 49-77 years) by adding melatonin to the culture medium, followed by the assessment of core aging biomarkers via quantitative immunohistochemistry. Over 6 days, 200 µM melatonin significantly downregulated the intraepidermal activity of the aging-promoting mTORC1 pathway (as visualized by reduced S6 phosphorylation) and MMP-1 protein expression in the epidermis compared to vehicle-treated control skin. Conversely, the transmembrane collagen 17A1, a key stem cell niche matrix molecule that declines with aging, and mitochondrial markers (e.g., TFAM, MTCO-1, and VDAC/porin) were significantly upregulated. Interestingly, 100 µM melatonin also significantly increased the epidermal expression of VEGF-A protein, which is required and sufficient for inducing human skin rejuvenation. In aged human dermis, melatonin significantly increased fibrillin-1 protein expression and improved fibrillin structural organization, indicating an improved collagen and elastic fiber network. In contrast, other key aging biomarkers (SIRT-1, lamin-B1, p16INK4, collagen I) remained unchanged. This ex vivo study provides proof of principle that melatonin indeed exerts long-suspected but never conclusively demonstrated and surprisingly differential anti-aging effects in aged human epidermis and dermis.

In silico design of bio-marker detection fluorescent probes.

Fluorescent probes capable of sensing the biological medium are of utmost importance in medical diagnostics. However, the optical spectrum of such probes needs to be tuned with care for compatibility with living tissues. More specifically, fluorescent bioprobes must be adjusted so as to avoid light interference with pigments (e.g. hemoglobin), tissue photodamage, scattering of the emitted light, and autofluorescence. This leads to two important conditions on the optical spectrum of the probes. On the one hand, the emission wavelength must be in an optical window of 650 to 950 nm. On the other hand, the Stokes shift must be large, ideally greater than 150 nm. In this paper, we showcase the in-silico design of potential fluorescent biomarkers fulfilling these two conditions by means of heteroatomic substitution and conjugation on a 1,2,4-triazole core initially far away from biological standards.

Diverticulitis with abscess formation: Outcomes of non-operative management and nomogram for predicting emergency surgery: The Diplicab Study Collaborative Group.

BACKGROUND: To assess short- and long-term outcomes from non-surgical management of diverticulitis with abscess formation and to develop a nomogram to predict emergency surgery. METHODS: This nationwide retrospective cohort study was performed in 29 Spanish referral centers, including patients with a first episode of a diverticular abscess (modified Hinchey Ib-II) from 2015 to 2019. Emergency surgery, complications, and recurrent episodes were analyzed. Regression analysis was used to assess risk factors, and a nomogram for emergency surgery was designed. RESULTS: Overall, 1,395 patients were included (1,078 Hinchey Ib and 317 Hinchey II). Most (1,184, 84.9%) patients were treated with antibiotics without percutaneous drainage, and 194 (13.90%) patients required emergency surgery during admission. Percutaneous drainage (208 patients) was associated with a lower risk of emergency surgery in patients with abscesses of ≥5 cm (19.9% vs 29.3%, P = .035; odds ratio 0.59 [0.37-0.96]). The multivariate analysis showed that immunosuppression treatment, C-reactive protein (odds ratio: 1.003; 1.001-1.005), free pneumoperitoneum (odds ratio: 3.01; 2.04-4.44), Hinchey II (odds ratio: 2.15; 1.42-3.26), abscess size 3 to 4.9 cm (odds ratio: 1.87; 1.06-3.29), abscess size ≥5 cm (odds ratio: 3.62; 2.08-6.32), and use of morphine (odds ratio: 3.68; 2.29-5.92) were associated with emergency surgery. A nomogram was developed with an area under the receiver operating characteristic curve of 0.81 (95% confidence interval: 0.77-0.85). CONCLUSION: Percutaneous drainage must be considered in abscesses ≥5 cm to reduce emergency surgery rates; however, there are insufficient data to recommend it in smaller abscesses. The use of the nomogram could help the surgeon develop a targeted approach.

Calculation of the ELF in the excited state with single-determinant methods.

Since its first definition, back in 1990, the electron localization function (ELF) has settled as one of the most commonly employed techniques to characterize the nature of the chemical bond in real space. Although most of the work using the ELF has focused on the study of ground-state chemical reactivity, a growing interest has blossomed to apply these techniques to the nearly unexplored realm of excited states and photochemistry. Since accurate excited electronic states usually require to account appropriately for electron correlation, the standard single-determinant ELF formulation cannot be blindly applied to them, and it is necessary to turn to correlated ELF descriptions based on the two-particle density matrix (2-PDM). The latter requires costly wavefunction approaches, unaffordable for most of the systems of current photochemical interest. Here, we compare the exact, 2-PDM-based ELF results with those of approximate 2-PDM reconstructions taken from reduced density matrix functional theory. Our approach is put to the test in a wide variety of representative scenarios, such as those provided by the lowest-lying excited electronic states of simple diatomic and polyatomic molecules. Altogether, our results suggest that even approximate 2-PDMs are able to accurately reproduce, on a general basis, the topological and statistical features of the ELF scalar field, paving the way toward the application of cost-effective methodologies, such as time-dependent-Hartree-Fock or time-dependent density functional theory, in the accurate description of the chemical bonding in excited states of photochemical relevance.

Disparities in Care Among Gunshot Victims: A Nationwide Analysis.

INTRODUCTION: Given the well-known healthcare disparities most pronounced in racial and ethnic minorities, trauma healthcare in underrepresented patients should be examined, as in-hospital bias may influence the care rendered to patients. This study seeks to examine racial differences in outcomes and resource utilization among victims of gunshot wounds in the United States. METHODS: This is a retrospective review of the National Trauma Data Bank (NTDB) conducted from 2007 to 2017. The NTDB was queried for patients who suffered a gunshot wound not related to accidental injury or suicide. Patients were stratified according to race. The primary outcome for this study was mortality. Secondary outcomes included racial differences in resource utilization including air transport and discharge to rehabilitation centers. Univariate and multivariate analyses were used to compare differences in outcomes between the groups. RESULTS: A total of 250,675 patients were included in the analysis. After regression analysis, Black patients were noted to have greater odds of death compared to White patients (odds ratio [OR] 1.14, confidence interval [CI] 1.037-1.244; P = 0.006) and decreased odds of admission to the intensive care unit (ICU) (OR 0.76, CI 0.732-0.794; P < 0.001). Hispanic patients were significantly less likely to be discharged to rehabilitation centers (Hispanic: 0.78, CI 0.715-0.856; P < 0.001). Black patients had the shortest time to death (median time in minutes: White 49 interquartile range [IQR] [9-437] versus Black 24 IQR [7-205] versus Hispanic 39 IQR [8-379] versus Asian 60 [9-753], P < 0.001). CONCLUSIONS: As society carefully examines major institutions for implicit bias, healthcare should not be exempt. Greater mortality among Black patients, along with differences in other important outcome measures, demonstrate disparities that encourage further analysis of causes and solutions to these issues.

The effect of the Belmont rapid infuser on cold stored whole blood coagulability.

INTRODUCTION: With the large-scale use of whole blood in massive transfusion using rapid infusers/fluid warmers such as the Belmont, questions remain as to whether coagulation potency, platelet number and function are preserved.  We aimed to study functional coagulation capacity and cell counts in whole blood before and after infusion through the Belmont rapid infuser utilizing TEG analysis and complete blood counts. METHODS: We evaluated 10 whole blood units before and after infusion through a Belmont Fluid Management System at a set rate of 200 mL/min and a temperature of 37.4 °C.  Cell counts and thromboelastography function of the specimens were measured. Parameters were compared utilizing paired Student's t-tests and paired Wilcoxon Rank Sign tests. RESULTS: Platelet count, R time, and Maximum amplitude showed significant decreases (defined as p<0.05) after being infused through the Belmont. Hemoglobin, hematocrit, MCV, and alpha angle were not statistically different before and after infusion. CONCLUSION: Infusion of cold stored whole blood in a Belmont infuser, appeared to decrease platelet counts and function as well as activate clotting factors as demonstrated by a shorter R time while not affecting red cell counts or fibrin cross-linking as measured by TEG parameters and cell counts. This suggests that while it is possible to transfuse whole blood through a rapid infuser, platelet quantity and function may be negatively impacted.

Molecular interactions from the density functional theory for chemical reactivity: Interaction chemical potential, hardness, and reactivity principles.

In the first paper of this series, the authors derived an expression for the interaction energy between two reagents in terms of the chemical reactivity indicators that can be derived from density functional perturbation theory. While negative interaction energies can explain reactivity, reactivity is often more simply explained using the "|dµ| big is good" rule or the maximum hardness principle. Expressions for the change in chemical potential (µ) and hardness when two reagents interact are derived. A partial justification for the maximum hardness principle is that the terms that appear in the interaction energy expression often reappear in the expression for the interaction hardness, but with opposite sign.

Molecular Interactions From the Density Functional Theory for Chemical Reactivity: The Interaction Energy Between Two-Reagents.

Reactivity descriptors indicate where a reagent is most reactive and how it is most likely to react. However, a reaction will only occur when the reagent encounters a suitable reaction partner. Determining whether a pair of reagents is well-matched requires developing reactivity rules that depend on both reagents. This can be achieved using the expression for the minimum-interaction-energy obtained from the density functional reactivity theory. Different terms in this expression will be dominant in different circumstances; depending on which terms control the reactivity, different reactivity indicators will be preferred.

On the Prediction of Lattice Energy with the Fukui Potential: Some Supports on Hardness Maximization in Inorganic Solids.

Using perturbation theory within the framework of conceptual density functional theory, we derive a lower bound for the lattice energy of the ionic solids. The main element of the lower bound is the Fukui potential in the nuclei of the molecule corresponding to the unit formula of the solid. Thus, we propose a model to calculate the lattice energy in terms of the Fukui potential. Our method, which is extremely simple, performs well as other methods using the crystal structure information of alkali halide solids. The method proposed here correlates surprisingly well with the experimental data on the lattice energy of a diverse series of solids having even a non-negligible covalent characteristic. Finally, the validity of the maximum hardness principle (MHP) is assessed, showing that in this case, the MHP is limited.

Links among the Fukui potential, the alchemical hardness and the local hardness of an atom in a molecule.

This paper presents a brief summary of the difficulty that resides in the definition of the elusive concept of local chemical hardness. We argue that a definition of local hardness should be useful to a reactivity principle and not just as a mere definition. We then continue with a formal discussion about the benefits and difficulties of using the Fukui potential, which is interpreted as an alchemical derivative (alchemical hardness), as descriptor of local hardness of molecules. Computational evidence shows that the alchemical hardness is at least as good a descriptor as the combination of other two well-stabilized descriptors of local hardness, such as the Fukui function and grand canonical local hardness. Although our results are auspicious for the alchemical hardness as descriptor of local hardness, we finish by calling the attention of the community on the importance of discussing the raison d'être of a local hardness function and its main characteristics. We suggest that an axiomatic construction of local hardness could be they way of constructing a local hardness which is both useful and free of arbitrariness.

Postoperative Outcomes after Index vs Interval Cholecystectomy for Perforated Cholecystitis.

BACKGROUND: Gallbladder perforation is a known morbid sequela of acute cholecystitis, yet evidence for its optimal management remains conflicting. This study compares outcomes in patients with perforated cholecystitis who underwent cholecystectomy at the time of index hospital admission with those in patients who underwent interval cholecystectomy. STUDY DESIGN: A retrospective analysis was conducted of 654 patients from the American College of Surgeons NSQIP database who underwent cholecystectomy for perforated cholecystitis (2006-2018). Primary outcomes were 30-day postoperative major and minor morbidity, 30-day mortality, and need for prolonged hospitalization. Patient and procedure characteristics and outcomes were compared using Mann-Whitney rank sum test for continuous variables and Pearson chi-square tests for categorical variables. A subset analysis was conducted of patients matched on propensity for undergoing interval cholecystectomy. RESULTS: The 30-day postoperative mortality rate of matched cohort patients undergoing index cholecystectomy was 7% vs 0% of patients undergoing interval cholecystectomy (p = 0.01). The 30-day minor morbidity rates were 2% for index and 8% for interval patients (p = 0.06), and the major morbidity rates were 33% for index and 14% for interval patients (p = 0.003). Of the index patients, 27% required prolonged hospitalization compared with 6% of interval patients (p < 0.001). Results showed similar trends in the unmatched analysis. CONCLUSIONS: Patients who underwent index cholecystectomy had significantly longer postoperative hospitalizations and higher 30-day postoperative major morbidity and mortality. There were no differences in 30-day minor morbidity. Selected patients with perforated cholecystitis can benefit from operative management on an interval, rather than urgent, basis.

Correlación de parámetros estereométricos por tomografía de coherencia óptica de segmento anterior y gonioscopía en una población del nororiente colombiano / Correlation between stereometric parameters by anterior segment coherent optical tomography and gonioscopy in Northeast Colombian populatio

Introducción: La gonioscopía es la técnica utilizada para diagnosticar la sospecha de cierre angular primario (SCAP). Sin embargo, es una medida subjetiva, a diferencia de la tomografía óptica coherente de segmento anterior (OCT-SA). Se realizó un estudio midiendo los parámetros estereoscópicos por OCT-SA y su correlación con la gonioscopía. Objetivo: Comparar la gonioscopía y los parámetros por OCT-SA en ojos con ángulo estrecho y abierto, y evaluar la reproducibilidad intraobservador de estos parámetros. Método: Estudio observacional, analítico, descriptivo y longitudinal. Se recolectó la información de los pacientes valorados en la consulta de glaucoma entre marzo y junio de 2019 sin antecedente de cirugía ni láser ocular a quienes se solicitó OCT-SA. Resultados: De 131 ojos, el 28.25% tenían ángulos estrechos y el 68.7% abiertos. La distancia de apertura del ángulo 500 (AOD) promedio nasal fue de 210 µm (rango intercuartílico [RIQ]: 98-275.5) y el temporal fue de 214 µm (RIQ: 130.5-289). El área del espacio del iris trabecular área 500 (TISA) promedio nasal fue de 0.070 mm2 (RIQ: 0.034-0.093) y el temporal fue de 0.068 mm2 (RIQ: 0.038-0.093). El ángulo del iris trabecular (TIA) nasal fue de 23.77° (RIQ: 12.11-29.92) y el temporal fue de 23.46° (RIQ: 14.37-30.45). Cuanto más abiertos están los ángulos por gonioscopía, mayor área de TISA, TIA y AOD. Existe una buena reproducibilidad intraobservador respecto al AOD nasal, con un coeficiente de concordancia de 0.956 (intervalo de confianza del 95% [IC95%]: 0.94- 0.97), y para el AOD temporal de 0.940 (IC95%: 0.92-0.96). Respecto al TISA nasal, el coeficiente de concordancia fue de 0.956 (IC95%: 0.9-0.97), y para el temporal de 0.946 (IC95%: 0.93-0.96). Conclusiones: La OCT-SA tiene una buena correlación con la gonioscopía y una buena reproducibilidad intraobservador. Sin embargo, sigue siendo una ayuda diagnóstica que no reemplaza la evaluación clínicaIntroducción: La gonioscopía es la técnica utilizada para diagnosticar la sospecha de cierre angular primario (SCAP). Sin embargo, es una medida subjetiva, a diferencia de la tomografía óptica coherente de segmento anterior (OCT-SA). Se realizó un estudio midiendo los parámetros estereoscópicos por OCT-SA y su correlación con la gonioscopía. Objetivo: Comparar la gonioscopía y los parámetros por OCT-SA en ojos con ángulo estrecho y abierto, y evaluar la reproducibilidad intraobservador de estos parámetros. Método: Estudio observacional, analítico, descriptivo y longitudinal. Se recolectó la información de los pacientes valorados en la consulta de glaucoma entre marzo y junio de 2019 sin antecedente de cirugía ni láser ocular a quienes se solicitó OCT-SA. Resultados: De 131 ojos, el 28.25% tenían ángulos estrechos y el 68.7% abiertos. La distancia de apertura del ángulo 500 (AOD) promedio nasal fue de 210 µm (rango intercuartílico [RIQ]: 98-275.5) y el temporal fue de 214 µm (RIQ: 130.5-289). El área del espacio del iris trabecular área 500 (TISA) promedio nasal fue de 0.070 mm2 (RIQ: 0.034-0.093) y el temporal fue de 0.068 mm2 (RIQ: 0.038-0.093). El ángulo del iris trabecular (TIA) nasal fue de 23.77° (RIQ: 12.11-29.92) y el temporal fue de 23.46° (RIQ: 14.37-30.45). Cuanto más abiertos están los ángulos por gonioscopía, mayor área de TISA, TIA y AOD. Existe una buena reproducibilidad intraobservador respecto al AOD nasal, con un coeficiente de concordancia de 0.956 (intervalo de confianza del 95% [IC95%]: 0.94- 0.97), y para el AOD temporal de 0.940 (IC95%: 0.92-0.96). Respecto al TISA nasal, el coeficiente de concordancia fue de 0.956 (IC95%: 0.9-0.97), y para el temporal de 0.946 (IC95%: 0.93-0.96). Conclusiones: La OCT-SA tiene una buena correlación con la gonioscopía y una buena reproducibilidad intraobservador. Sin embargo, sigue siendo una ayuda diagnóstica que no reemplaza la evaluación clínica

Introduction: Gonioscopy is the technique used to diagnose primary angle closure suspect (PACS). Nevertheless, it is a subjective measure compared to anterior segment coherent optical tomography (AS-OCT). A study was performed by measuring the stereoscopic parameters with AS-OCT and correlating them with gonioscopy. Objective: To compare gonioscopy and AS-OCT parameters in eyes with closed and open angle. Moreover, to evaluate intraobserver reproducibility of those parameters. Method: Observational, analytical descriptive longitudinal study. Data was collected from patients who attended glaucoma service between March and June 2019 and had an AS-OOCT done. Patients were excluded if they had history of laser or intraocular surgery. Results: Out of 131 eyes, 28.25% had closed angles and 68.7% open angles. The average nasal angle opening distance 500 (AOD) was 210 µm ICR (98 ­ 275.5) and the temporal was 214 µm ICR (130.5 ­ 289). The average nasal trabecular iris space area 500 (TISA) was 0.070 mm2 ICR (0.034 ­ 0.093) and the temporal was 0.068 mm2 ICR (0.038 ­ 0.093). The nasal trabecular iris angle (TIA) was 23.77º ICR (12.11 ­ 29.92) and the temporal was 23.46º ICR (14.37 ­ 30.45). The wider the angles by gonioscopy, the greater the area of TISA, TIA and AOD. A good nasal AOD intraobserver reproducibility was observed with a concordance coefficient of 0.956 (IC 95%: 0.94 ­ 0.97) and temporal AOD of 0.940 (0.92 ­ 0.96). Regarding the nasal TISA, the concordance coefficient was 0.956 (IC 95%: 0.9 ­ 0.97) and temporal TISA was 0.946 (IC 95: 0.93 ­ 0.96). Conclusions: AS-OCT has a strong correlation with gonioscopy and a good intraobserver reproducibility. However, it remains as a diagnostic aid that does not substitute clinical evaluation.

Mechanical and Antimicrobial Polyethylene Composites with CaO Nanoparticles.

Low-density polyethylene composites containing different sizes of calcium oxide (CaO) nanoparticles were obtained by melt mixing. The CaO nanoparticles were synthesized by either the sol-gel or sonication methods, obtaining two different sizes: ca. 55 nm and 25 nm. These nanoparticles were used either as-synthesized or were modified organically on the surface with oleic acid (Mod-CaO), at concentrations of 3, 5, and 10 wt% in the polymer. The Mod-CaO nanoparticles of 25 nm can act as nucleating agents, increasing the polymer's crystallinity. The Young's Modulus increased with the Mod-CaO nanoparticles, rendering higher reinforcement effects with an increase as high as 36%. The reduction in Escherichia coli bacteria in the nanocomposites increased with the amount of CaO nanoparticles, the size reduction, and the surface modification. The highest antimicrobial behavior was found in the composites with a Mod-CaO of 25 nm, presenting a reduction of 99.99%. This strong antimicrobial effect can be associated with the release of the Ca2+ from the composites, as studied for the composite with 10 wt% nanoparticles. The ion release was dependent on the size of the nanoparticles and their surface modification. These findings show that CaO nanoparticles are an excellent alternative as an antimicrobial filler in polymer nanocomposites to be applied for food packaging or medical devices.

Electron Localization Function in Excited States: The Case of the Ultrafast Proton Transfer of the Salicylidene Methylamine.

The physical characterization of the chemical bond in the ground state has been a central theme to theoretical chemistry. Among many techniques, quantum chemical topology (QCT) has emerged as a robust technique to understand the features of the chemical bond and electron organization within molecules. One consolidate tool within QCT is the topological analysis of the electron localization function (ELF). Most research on ELF and chemical bond has focused either on singlet ground states or the first excited triplet. However, most photochemical reactions and photophysical processes occur in excited states with the same spin-symmetry as the ground state. In this work, we develop a proposal on how to compute the ELF in excited states of any symmetry within linear-response time-dependent density functional theory. Then, we study the evolution of the chemical bonds in the ground- and excited-state intramolecular proton transfer (ESIPT) of a prototypal Schiff base (the salicylidene methylamine). We found that the topological analysis of the ELF along reaction paths explains the presence of a barrier for the proton transfer in the ground state and the absence of it in the excited state. Briefly, in the ground state, the cleavage of the O-H bond results in a structure with high electrostatic potential energy due to an excess of electron lone-pairs (3) in the oxygen atom, which explains the barrier. In the excited state, the electronic transition promotes an enhancement of the basicity of nitrogen by allocating three nonbonding electrons in the basin of its lone-pair. This excess of electrons in the N exerts an electrostatic attraction of the proton, which we suggest as the primary driven-force of the barrierless reaction. Because in excited states the molecule can develop more vibrational kinetic energy than in the ground state, we performed an ab initio molecular dynamics of the proton transfer in the excited state and corroborate that our conclusions on the topology of the ELF do not change due to dynamic effects.

Improvement of the drought indicators system in the Júcar River Basin, Spain.

Droughts are one of the gravest natural threats currently existing in the world and their occurrence and intensity might be exacerbated in the coming years due to climate change. The severe impacts that droughts cause to inland water resources and to the associated socio-economic activities justify the continuous monitoring of the drought. The case study presented shows a practical application of a distributed drought monitoring system implemented in a real river basin district, the Júcar River Basin District (43,000km2), where drought periods of marked intensity have occurred historically and the climate ranges from humid in the north to semiarid in the south. Five drought indices have been applied: Standardised Precipitation Index (SPI) for meteorological drought; Palmer Drought Severity Index (PDSI) and a new soil moisture index (HI), for edaphic drought; Normalised Difference Vegetation Index (NDVI) for the vegetation activity; and Spanish Status Index (SI), for the operational drought. All indices are standardised to compare them. The relationship between the standardised operational drought index SI and the long-term meteorological indices, SPI-12 or SPI-24, show that in a medium size basin the concept of "prolonged drought" required by the European Commission under the Water Framework Directive could be defined by the use of accumulated precipitation indices. The number of months to be accumulated depends on the size of the basin and the water management system properties. In large basins, such as the Júcar river basin (22,000km2), there are significant deviations due to the spatial distribution of the drought. The use of a unique aggregated indicator could hide a significant drought in a specific area, or on the other hand show a non-real drought. Evolution of drought indices for each water management system must be accompanied by spatially distributed drought maps to better understand the drought status and its evolution.

Exploring the relevance of thiophene rings as bridge unit in acceptor-bridge-donor dyes on self-aggregation and performance in DSSCs.

The possibility of dye charge recombination in DSSCs remains a challenge for the field. This consists of: (a) back-transfer from the TiO2 to the oxidized dye and (b) intermolecular electron transfer between dyes. The latter is attributed to dye aggregation due to dimeric conformations. This leads to poor electron injection which decreases the photocurrent conversion efficiency. Most organic sensitizers are characterized by an Acceptor-Bridge-Donor (A-Bridge-D) arrangement that is commonly employed to provide charge separation and, therefore, lowering the unwanted back-transfer. Here, we address the intermolecular electron transfer by studying the dimerization and photovoltaic performance of a group of A-Bridge-D structured dyes. Specifically, eight famous sulfur containing π-bridges were analyzed (A and D remained fixed). Through quantum mechanical and molecular dynamics approaches, it was found that the formation of weakly stabilized dimers is allowed. The dyes with covalently bonded and fused thiophene rings as Bridges, 6d and 7d as well as 8d with a fluorene, would present high aggregation and, therefore, high probability of recombination processes. Conversely, using TiO2 cluster and surface models, delineated the shortest bridges to improve the adsorption energy and the stability of the system. Finally, the elongation of the bridge up to 2 and 3 units and their photovoltaic parameters were studied. These results showed that all the sensitizers are able to provide similar photocurrent outcomes, regardless of whether the bridge is elongated. © 2017 Wiley Periodicals, Inc.

Enfermedad pulmonar causada por complejo Mycobacterium avium y M. abscessus / Pulmonary disease caused by Mycobacterium avium complex and M. abscessus

Resumen Introducción: después del complejo Mycobacterium tuberculosis, las principales especies de micobacterias causando enfermedad pulmonar son el complejo Mycobacterium avium (MAC) y Mycobacterium abscessus, el tratamiento es prolongado, presentan un amplio perfil de resistencia y algunas veces es necesaria la resección quirúrgica del tejido, dificultando la curación de algunos casos. Objetivo: realizar un análisis de los casos a los que se les aisló de muestras pulmonares MAC y M. abscessus en el periodo de 2012-2014 en el Laboratorio Nacional de Referencia de Colombia. Material y métodos: se realizó un estudio de serie de casos de 42 personas a las que se les aisló de muestras pulmonares MAC y M. abscessus, los cuales fueron identificados mediante pruebas fenotípicas y genotípicas. La fuente de información fue el Formato Único de Vigilancia de las Micobacterias que se recibe con cada uno de los aislados que llegan al INS. Se analizaron las variables edad, sexo, tipo de muestra y presencia de factores de riesgo. Resultados: en 32 de los casos se identificó MAC y en 10 M. abscessus como agente etiológico causante de enfermedad pulmonar, 26 (61.9%) de los casos tenían entre 51 y 86 años. Los principales factores de riesgo fueron: antecedente de tratamiento antituberculosis 16 (38.1%) y persona con VIH 7 (16.7%) y sin factor de riesgo 9 (21.2%) casos. Discusión: este trabajo reporta como agente etiológico MAC y M. abscessus en personas mayores de 50 años sin factores de riesgo, con antecedentes de tuberculosis, indicando que se debe fortalecer la realización de cultivo e identificación de especie en éstas para que tengan un adecuado diagnóstico y tratamiento.

Abstract Introduction: after the Mycobacterium tuberculosis complex, the main species of mycobacteria causing lung disease are Mycobacterium avium complex and Mycobacterium abscessus. The treatment is prolonged; they present a broad resistance profile and sometimes the surgical resection of the tissue is necessary, making healing difficult in some cases. Objective: to perform an analysis of the cases to which MAC and M. abscessus were isolated from pulmonary samples in the period from 2012 to 2014 in the National Reference Laboratory of Colombia. Materials and Methods: a case series study of 42 individuals to whom Mac and M. abcessus were isolated from pulmonary samples that were identified by phenotypic and genotypic tests, was carried out. The source of information was the unique format of surveillance of mycobacteria that is received with each of the isolates that come to the National Health Institute. The variables age, sex, type of sample and presence of risk factors were analyzed. Results: in 32 patients MAC was identified as etiological agent causing pulmonary disease and in 10 cases, M. abscessus was the agent. 26 (61.9%) of the patients were between 51 and 86 years of age. The main risk factors were: antecedent of anti-tuberculosis treatment in16 (38.1%),7 with HIV (16.7%) and without risk factor 9 cases (21.2%).