Regulatory functions of homeobox domain transcription factors in fungi.

Homeobox domain (HD) proteins present a crucial involvement in morphological differentiation and other functions in eukaryotes. Most HD genes encode transcription factors (TFs) that orchestrate a regulatory role in cellular and developmental decisions. In fungi, multiple studies have increased our understanding of these important HD regulators in recent years. These reports have revealed their role in fungal development, both sexual and asexual, as well as their importance in governing other biological processes in these organisms, including secondary metabolism, pathogenicity, and sensitivity to environmental stresses. Here, we provide a comprehensive review of the current knowledge on the regulatory roles of HD-TFs in fungi, with a special focus on Aspergillus species.

Dripping, jetting and tip streaming.

Dripping, jetting and tip streaming have been studied up to a certain point separately by both fluid mechanics and microfluidics communities, the former focusing on fundamental aspects while the latter on applications. Here, we intend to review this field from a global perspective by considering and linking the two sides of the problem. First, we present the theoretical model used to study interfacial flows arising in droplet-based microfluidics, paying attention to three elements commonly present in applications: viscoelasticity, electric fields and surfactants. We review both classical and current results of the stability of jets affected by these elements. Mechanisms leading to the breakup of jets to produce drops are reviewed as well, including some recent advances in this field. We also consider the relatively scarce theoretical studies on the emergence and stability of tip streaming in open systems. Second, we focus on axisymmetric microfluidic configurations which can operate on the dripping and jetting modes either in a direct (standard) way or via tip streaming. We present the dimensionless parameters characterizing these configurations, the scaling laws which allow predicting the size of the resulting droplets and bubbles, as well as those delimiting the parameter windows where tip streaming can be found. Special attention is paid to electrospray and flow focusing, two of the techniques more frequently used in continuous drop production microfluidics. We aim to connect experimental observations described in this section of topics with fundamental and general aspects described in the first part of the review. This work closes with some prospects at both fundamental and practical levels.

Electrospray cone-jet mode for weakly viscoelastic liquids.

We study theoretically the influence of viscoelasticity on the steady cone-jet mode of electrospray for small stress relaxation times. For this purpose, we numerically integrate the leaky-dielectric model together with the Oldroyd-B constitutive relationship and calculate both the base flow and linear eigenmodes characterizing its stability as a function of the governing parameters. We describe the effect of the polymeric stresses on both the cone-jet mode and the minimum flow rate stability limit. There are considerable differences between the Newtonian and viscoelastic electrospray realizations even for relatively small stress relaxation times due to the intense extensional deformation suffered by the fluid particles in the cone-jet transition region The axial polymeric stress shrinks the liquid meniscus and stabilizes it by pushing the fluid particle in the cone-to-jet transition region.

Aerodynamically stabilized Taylor cone jets.

We introduce a way to stabilize steady micro/nanoliquid jets issuing from Taylor cones together with coflowing gas streams. We study the dripping-jetting transition of this configuration theoretically through a global stability analysis as a function of the governing parameters involved. A balance between the local radial acceleration to the surface tension gradient, the mass conservation, and the energy balance equations enable us to derive two coupled scaling laws that predict both the minimum jet diameter and its maximum velocity. The theoretical prediction provides a single curve that describes not only the numerical computations but also experimental data from the literature for cone jets assisted with gas coflow. Additionally, we performed a set of experiments to verify what parameters influence the jet length. We adopt a very recent model for capillary jet length to our configuration by combining electrohydrodynamic effects with the gas flow through an equivalent liquid pressure. Due to diameters below 1 µm and high speeds attainable in excess of 100 m/s, this concept has the potential to be utilized for structural biology analyses with x-ray free-electron lasers at megahertz repetition rates as well as other applications.

Efficacy of oral diclofenac with or without codeine for pain control after invasive bilateral third molar extractions.

Postoperative pain and inflammation after oral surgery is mostly managed using non-steroidal anti-inflammatory drugs (NSAIDs). However, opioids combined with NSAIDs may improve pain management in patients, especially after traumatic oral surgery. Few studies have compared NSAIDs with and without opioid use after oral and maxillofacial surgery. This randomized, double-blind, cross-over study compared the clinical efficacy of either diclofenac (50mg) and codeine (50mg) or diclofenac alone (50mg) for the management of postoperative pain after invasive third molar surgery. Volunteers (n=46) who were scheduled to undergo the removal of symmetrically positioned lower third molars in two separate appointments were included. They reported significantly less postoperative pain at various time points within 24h after surgery and also consumed significantly less rescue medication (paracetamol (acetaminophen)) throughout the study when they took diclofenac combined with codeine than when they took only diclofenac. In conclusion, oral diclofenac with codeine was more effective for managing postoperative pain than diclofenac without codeine. It was expected that patients taking two pain medications after surgery would generally have less pain than when taking only one of the two medications. The prospective cross-over design of the present work makes this study distinct from many others.

Efficacy of naproxen with or without esomeprazole for pain and inflammation in patients after bilateral third molar extractions: A double blinded crossover study.

BACKGROUND: Using a double-blinded randomized crossover design, this study aimed to evaluate acute postoperative pain management, swelling and trismus in 46 volunteers undergoing extractions of the two lower third molars, in similar positions, at two different appointments who consumed a tablet of either NE (naproxen 500 mg + esomepraz ole 20 mg) or only naproxen (500 mg) every 12 hours for 4 days. MATERIAL AND METHODS: Parameters were analyzed: self-reported pain intensity using a visual analog scale (VAS) pre- and postoperative mouth opening; incidence, type and severity of adverse reactions; total quantity consumed of rescue medication; and pre- and postoperative swelling. RESULTS: Female volunteers reported significantly more postoperative pain at 1, 1.5, 2, 3 and 4hrs after surgery while also taking their first rescue medication at a time significantly earlier when consuming NE when compared to naproxen (3.7hrs and 6.7hrs). Conversely, no differences were found between each drug group in males. CONCLUSIONS: In conclusion, throughout the entire study, pain was mild after using either drug in both men and women with pain scores on average well below 40mm (VAS), although in women naproxen improved acute postoperative pain management when compared to NE.

Monosized dripping mode of axisymmetric flow focusing.

We identify and analyze the perfectly regular dripping mode of flow focusing. This mode occurs within narrow intervals of injected flow rates and applied pressure drops and leads to homogeneous-size droplets with diameters similar to or smaller than that of the discharge orifice. The balance between the local acceleration of the fluid particle and the applied pressure drop yields the scaling law for the droplet diameter. This scaling law is validated experimentally with excellent accord.

The onset of electrospray: the universal scaling laws of the first ejection.

The disintegration of liquid drops with low electrical conductivity and subject to an electric field is investigated both theoretically and experimentally. This disintegration takes place through the development of a conical cusp that eventually ejects an ultrathin liquid ligament. A first tiny drop is emitted from the end of this ligament. Due to its exceptionally small size and large electric charge per unit volume, that drop has been the object of relevant recent studies. In this paper, universal scaling laws for the diameter and electric charge of the first issued droplet are proposed and validated both numerically and experimentally. Our analysis shows how charge relaxation is the mechanism that differentiates the onset of electrospray, including the first droplet ejection, from the classical steady cone-jet mode. In this way, our study identifies when and where charge relaxation and electrokinetic phenomena come into play in electrospray, a subject of live controversy in the field.

Convective-to-absolute instability transition in a viscoelastic capillary jet subject to unrelaxed axial elastic tension.

The convective-to-absolute instability transition in an Oldroyd-B capillary jet subject to unrelaxed axial stress is examined theoretically. There is a critical Weber number below which the jet is absolutely unstable under axisymmetric perturbations. We analyze the dependence of this critical parameter with respect to the Reynolds and Deborah numbers, as well as the unrelaxed axial stress. For small Deborah numbers, the unrelaxed stress destabilizes the viscoelastic jet, increasing the critical Weber number for which the convective-to-absolute instability transition takes place. If the Deborah number takes higher values, then the transitional Weber number decreases as the unrelaxed stress increases until two solution branches cross each other. The dominant branch for large axial stress leads to a threshold of this quantity above which the viscoelastic jet becomes absolutely unstable independently of the Weber number. The threshold depends on neither the Reynolds nor the Deborah number for sufficiently large values of these parameters.

Efficacy and Safety of 2% and 4% Articaine for Lower Third Molar Surgery.

This double-blind crossover randomized clinical trial compared the efficacy of 2 concentrations of articaine, 2% (A2) and 4% (A4), with 1:200,000 epinephrine, for lower third molar removal. During 2 separate appointments with either A2 or A4, both similarly positioned lower third molars in 46 volunteers were extracted. The following were evaluated: onset and duration of anesthetic action on soft tissues, intraoperative bleeding, hemodynamic parameters, postoperative analgesia, and mouth opening and wound healing during the 7th postoperative day, along with the incidence, type, and severity of adverse reactions. Nearly identical volumes of both anesthetic solutions were used for each appointment: 3.4 ± 0.9 mL ≈ 68 mg of articaine (A2) and 3.3 ± 0.8 mL ≈ 132 mg of articaine (A4). Statistical analysis indicated no differences in onset or duration of anesthetic action on soft tissues or duration of postoperative analgesia evoked by A2 and A4 anesthetic solutions (P > 0.05). The surgeon's rating of intraoperative bleeding was considered minimal throughout all surgery with both anesthetic solutions. While transient changes in blood pressure, heart rate, and oxygen saturation were observed, these factors were clinically insignificant and were uninfluenced by articaine concentration (P > 0.05). No systemic or local adverse reactions were observed in the preoperative and postoperative periods due to A2 or A4, but 1 case of bilateral paresthesia was observed. There were no significant differences between preoperative and postoperative (7th day) values of mouth opening and wound healing whether volunteers received A2 or A4 (P > 0.05). In conclusion, both A2 and A4, administered in equal volumes, were effective and safe during lower third molar surgery, and no significant differences were found between their efficacy and safety (ClinicalTrials.gov NCT02457325).

Transcriptome Analysis of Aspergillus flavus Reveals veA-Dependent Regulation of Secondary Metabolite Gene Clusters, Including the Novel Aflavarin Cluster.

The global regulatory veA gene governs development and secondary metabolism in numerous fungal species, including Aspergillus flavus. This is especially relevant since A. flavus infects crops of agricultural importance worldwide, contaminating them with potent mycotoxins. The most well-known are aflatoxins, which are cytotoxic and carcinogenic polyketide compounds. The production of aflatoxins and the expression of genes implicated in the production of these mycotoxins are veA dependent. The genes responsible for the synthesis of aflatoxins are clustered, a signature common for genes involved in fungal secondary metabolism. Studies of the A. flavus genome revealed many gene clusters possibly connected to the synthesis of secondary metabolites. Many of these metabolites are still unknown, or the association between a known metabolite and a particular gene cluster has not yet been established. In the present transcriptome study, we show that veA is necessary for the expression of a large number of genes. Twenty-eight out of the predicted 56 secondary metabolite gene clusters include at least one gene that is differentially expressed depending on presence or absence of veA. One of the clusters under the influence of veA is cluster 39. The absence of veA results in a downregulation of the five genes found within this cluster. Interestingly, our results indicate that the cluster is expressed mainly in sclerotia. Chemical analysis of sclerotial extracts revealed that cluster 39 is responsible for the production of aflavarin.

Production of microbubbles from axisymmetric flow focusing in the jetting regime for moderate Reynolds numbers.

We analyze both experimentally and numerically the formation of microbubbles in the jetting regime reached when a moderately viscous liquid stream focuses a gaseous meniscus inside a converging micronozzle. If the total (stagnation) pressure of the injected gas current is fixed upstream, then there are certain conditions on which a quasisteady gas meniscus forms. The meniscus tip is sharpened by the liquid stream down to the gas molecular scale. On the other side, monodisperse collections of microbubbles can be steadily produced in the jetting regime if the feeding capillary is appropriately located inside the nozzle. In this case, the microbubble size depends on the feeding capillary position. The numerical simulations for an imposed gas flow rate show that a recirculation cell appears in the gaseous meniscus for low enough values of that parameter. The experiments allow one to conclude that the bubble pinch-off comprises two phases: (i) a stretching motion of the precursor jet where the neck radius versus the time before the pinch essentially follows a potential law, and (ii) a final stage where a very thin and slender gaseous thread forms and eventually breaks apart into a number of micron-sized bubbles. Because of the difference between the free surface and core velocities, the gaseous jet breakage differs substantially from that of liquid capillary jets and gives rise to bubbles with diameters much larger than those expected from the Rayleigh-type capillary instability. The dependency of the bubble diameter upon the flow-rate ratio agrees with the scaling law derived by A. M. Gañán-Calvo [Phys. Rev. E 69, 027301 (2004)], although a slight influence of the Reynolds number can be observed in our experiments.

The volatome of Aspergillus fumigatus.

Early detection of invasive aspergillosis is absolutely required for efficient therapy of this fungal infection. The identification of fungal volatiles in patient breath can be an alternative for the detection of Aspergillus fumigatus that still remains problematic. In this work, we investigated the production of volatile organic compounds (VOCs) by A. fumigatus in vitro, and we show that volatile production depends on the nutritional environment. A. fumigatus produces a multiplicity of VOCs, predominantly terpenes and related compounds. The production of sesquiterpenoid compounds was found to be strongly induced by increased iron concentrations and certain drugs, i.e., pravastatin. Terpenes that were always detectable in large amounts were α-pinene, camphene, and limonene, as well as sesquiterpenes, identified as α-bergamotene and ß-trans-bergamotene. Other substance classes that were found to be present in the volatome, such as 1-octen-3-ol, 3-octanone, and pyrazines, were found only under specific growth conditions. Drugs that interfere with the terpene biosynthesis pathway influenced the composition of the fungal volatome, and most notably, a block of sesquiterpene biosynthesis by the bisphosphonate alendronate fundamentally changed the VOC composition. Using deletion mutants, we also show that a terpene cyclase and a putative kaurene synthase are essential for the synthesis of volatile terpenes by A. fumigatus. The present analysis of in vitro volatile production by A. fumigatus suggests that VOCs may be used in the diagnosis of infections caused by this fungus.

Theoretical investigation of a technique to produce microbubbles by a microfluidic T junction.

A microfluidic technique is proposed to produce microbubbles. A gaseous stream is injected through a T junction into a channel transporting a liquid current. The gas adheres to a hydrophobic strip printed on the channel surface. When the gas and liquid flow rates are set appropriately, a gaseous rivulet flows over that strip. The rivulet breaks up downstream due to a capillary pearling instability, which leads to a monodisperse collection of microbubbles that can be much smaller than the channel size. The physics of the process is theoretically investigated, using both full numerical simulation of the Navier-Stokes equations and a linear stability analysis of an infinite gaseous rivulet driven by a coflowing liquid stream. This stability analysis allows one to determine a necessary condition to get this effect in a T junction device. It also provides reasonably good predictions for the size of the produced microbubbles as obtained from numerical experiments.

Building functional materials for health care and pharmacy from microfluidic principles and Flow Focusing.

In this review, we aim at establishing a relationship between the fundamentals of the microfluidics technologies used in the Pharmacy field, and the achievements accomplished by those technologies. We describe the main methods for manufacturing micrometer drops, bubbles, and capsules, as well as the corresponding underlying physical mechanisms. In this regard, the review is intended to show non-specialist readers the dynamical processes which determine the success of microfluidics techniques. Flow focusing (FF) is a droplet-based method widely used to produce different types of fluid entities on a continuous basis by applying an extensional co-flow. We take this technique as an example to illustrate how microfluidics technologies for drug delivery are progressing from a deep understanding of the physics of fluids involved. Specifically, we describe the limitations of FF, and review novel methods which enhance its stability and robustness. In the last part of this paper, we review some of the accomplishments of microfluidics when it comes to drug manufacturing and delivery. Special attention is paid to the production of the microencapsulated form because this fluidic structure gathers the main functionalities sought for in Pharmacy. We also show how FF has been adapted to satisfy an ample variety of pharmaceutical requirements to date.

Numerical simulation of electrospray in the cone-jet mode.

We present a robust and computationally efficient numerical scheme for simulating steady electrohydrodynamic atomization processes (electrospray). The main simplification assumed in this scheme is that all the free electrical charges are distributed over the interface. A comparison of the results with those calculated with a volume-of-fluid method showed that the numerical scheme presented here accurately describes the flow pattern within the entire liquid domain. Experiments were performed to partially validate the numerical predictions. The simulations reproduced accurately the experimental shape of the liquid cone jet, providing correct values of the emitted electric current even for configurations very close to the cone-jet stability limit.

The conserved global regulator VeA is necessary for symptom production and mycotoxin synthesis in maize seedlings by Fusarium verticillioides.

The veA or velvet gene is necessary for biosynthesis of mycotoxins and other secondary metabolites in Aspergillus species. In addition, veA has also been demonstrated to be necessary for normal seed colonization in Aspergillus flavus and Aspergillus parasiticus. The present study shows that veA homologues are broadly distributed in fungi, particularly in Ascomycetes. The Fusarium verticillioides veA orthologue, FvVE1, is also required for the synthesis of several secondary metabolites, including fumonisin and fusarins. This study also shows that maize plants grown from seeds inoculated with FvVE1 deletion mutants did not show disease symptoms, while plants grown from seeds inoculated with the F. verticillioides wildtype and complementation strains clearly showed disease symptoms under the same experimental conditions. In this latter case, the presence of lesions coincided with accumulation of fumonisins in the plant tissues, and only these plant tissues had elevated levels of sphingoid bases and their 1-phosphate derivatives, indicating inhibition of ceramide synthase and disruption of sphingolipid metabolism. The results strongly suggest that FvVE1 is necessary for pathogenicity by F. verticillioides against maize seedlings. The conservation of veA homologues among ascomycetes suggests that veA could play a pivotal role in regulating secondary metabolism and associated pathogenicity in other fungi.

Condición de salud y cumplimiento de la guía clínica chilena para el cuidado del paciente diabético tipo / Health condition and compliance of the chilean clinical guideline for type 2 diabetic patients

Objetivo: Identificar condición de salud (CS) de los pacientes diabéticos tipo 2. Medir el cumplimiento de las atenciones de salud según guía clínica. Identificar variables asociadas a CS. Material y método: estudio de pre-valencia, abril 2010. Población: 1.100 pacientes DM2 controlados en Programa Cardiovascular, considerando criterios de inclusión, exclusión, consentimiento informado. Muestra: 340 por aleatorización simple (confianza 95 por ciento merma 10 por ciento). Recolección de datos realizada en CESFAM o visita domiciliaria por investigadoras e internas de enfermería entrenadas, con encuesta validada, exámenes, plantilla para información y ficha clínica. Para el análisis se utilizó estadística descriptiva, Chi2, Odds Ratios con IC (95 por ciento). Resultados: CS: descompensados (HbA1c>7 por ciento) 56.5 por ciento, patologías agregadas 97.9 por ciento, complicaciones 25 por ciento, mayor frecuencia retinopatía diabética. hombres mayor riesgo de amputación (p=0.003). Presión arterial >130/85 mm.hg. 58.2 por ciento, sobrepeso-obesidad 71.2 por ciento, autovalencia (adultos mayores) 23.1 por ciento. Cumplimiento recomendaciones ministeriales: controles/profesionales/año a lo menos cinco 41.5 por ciento, CESFAM adapta esta recomendación. Evaluación anual de: pie diabético 78 por ciento, fondo ojo 41,6 por ciento. Indicación régimen (nutricionista) último control 80 por ciento. Cinco controles profesionales/ año o más es protector de compensación de diabetes, IC (0.62-0.95), resto de recomendaciones y adaptación de éstas no se asocian a condición de salud (p > 0.05). Conclusiones: Los componentes de condición de salud están en general por sobre lo esperado. En ningún paciente se cumple en un 100 por ciento las recomendaciones de la guía clínica. Cinco o más controles profesionales anuales se asocian a compensación de la diabetes. Importante cumplir recomendaciones para mejorar control metabólico y disminuir/retrasar complicaciones para una mejor calidad de vida de pacientes.

Objectives: To determine compliance with Chilean clinical guideline and to measure their impact through evaluation of patient’s health condition (HC), to determine associations. Methods: prevalence study, April 2010. Population: 1,100 diabetic patients controlled in the Cardiovascular Program, considering criteria of inclusion, exclusion, informed consent. Sample: 340 randomized patients (Confidence level: 95 percent; Loss: 10 percent). Information was collected in an outpatient clinic and through home visits performed by researchers and trained senior nursing students, with a validated survey, exams, staff for file information. For the purposes of the analysis, descriptive statistics was used, Chi2, Odds Ratios with CI (95 percent). Results: HC: decompensation (HbA1c>7 percent 56.5 percent derived illnesses 97.9 percent, complications 25 percent, greater frequency of diabetic retinopathy. Males with greater risk of amputation (p=0.003). Blood pressure >130/85 mm. hg. 58.2 percent, overweight-obesity 71.2 percent, self-care (older adults) 23.1 percent. Compliance with clinical guideline: controls/professionals/year at least five 41.5 percent, CESFAM adapts this recommendation. Annual evaluation of: diabetic foot 78 percent, fundoscopy 41.6 percent. Regime indication (dietician) last control 80 percent. Five professional controls/year or more protect compensation for diabetes, IC (0.62-0.95), other recommendations and adaptation of recommendations are not associated with health status (p > 0.05). Conclusions: components of hC are better than expected. In none of the patients are the recommendations of the clinical guideline fulfilled in a 100 percent. 5 or more annual outpatient visits are associated to good metabolic control. Compliance with clinical guideline recommendations is important to improve metabolic control, to lessen complications and to improve patient’s quality of life.

Role of nitric oxide and flavohemoglobin homolog genes in Aspergillus nidulans sexual development and mycotoxin production.

Flavohemoglobins are widely distributed in both prokaryotes and eukaryotes. These proteins are involved in reducing nitric oxide levels. Deletion of the Aspergillus nidulans flavohemoglobin gene fhbA induced sexual development and decreased sterigmatocystin production. Supplementation with a nitric oxide-releasing compound promoted cleistothecial formation and increased nsdD and steA expression, indicating that nitric oxide induces sexual development. This is the first study on the effect of nitric oxide on morphogenesis and secondary metabolism in fungi.