Assessment of the marine microalga Chrysochromulina rotalis as bioactive feedstock cultured in an easy-to-deploy light-emitting-diode-based tubular photobioreactor.

Marine microalgae have potential to be low-cost raw materials. This depends on the exploitation of different biomass fractions for high-value products, including unique compounds. Chrysochromulina rotalis, an under-explored haptophyte with promising properties, was the focus of this study. For the first time, C. rotalis was successfully cultivated in an 80 L tubular photobioreactor, illuminated by an easy-to-use light-emitting-diode-based system. C. rotalis grew without certain trace elements and showed adaptability to different phosphorus sources, allowing a significant reduction in the N:P ratio without compromising biomass yield and productivity. The design features of the photobioreactor provided a protective environment that ensured consistent biomass production from this shear-sensitive microalgae. Carotenoid analysis showed fucoxanthin and its derivatives as major components, with essential fatty acids making up a significant proportion of the total. The study emphasizes the tubular photobioreactor's role in sustainable biomass production for biorefineries, with C. rotalis as a valuable bioactive feedstock.

Eficacia y seguridad del implante XEN45 en la cirugía de glaucoma. Estudio retrospectivo de nuestros primeros 73 casos / Efficacy and safety of the XEN45 implant in glaucoma surgery: Retrospective study of our first 73 cases

Objetivo Analizar los resultados del implante XEN45 en nuestro centro hospitalario, tanto en términos de eficacia como en cuanto a seguridad. Método Estudio observacional, retrospectivo y monocéntrico de los pacientes intervenidos de XEN45 en el Hospital Universitario de Jaén entre el 1 de enero de 2018 y el 31 de junio de 2021. Resultados Se implantó el dispositivo XEN45 a un total de 73 pacientes (48 cirugía combinada con facoemulsificación del cristalino y 25 de forma aislada). La PIO disminuyó de 19,9±4,9mmHg en la primera visita hasta una media de 17,1±5,3 (p=0,001) en el sexto mes. Se redujo de 2,1±0,9 a 0,6 el uso de fármacos necesarios entre la primera visita y el mes tras el implante XEN (p<0,000). Fue necesaria una segunda cirugía en 18 pacientes (26,6%) en los 6 primeros meses. Conclusiones La cirugía de glaucoma mediante implante XEN45, en solitario o combinado con la cirugía de catarata, es un procedimiento eficaz y seguro para la disminución de la PIO (AU)

Objective To analyze the results of the XEN45 implant in our hospital center, both in terms of efficacy and safety. Methods Observational, retrospective, single-center study of patients undergoing XEN45 surgery at the University Hospital of Jaén between January 1, 2018 and June 31, 2021. Results A total of 73 patients were implanted with the XEN45 device (48 with in combined surgery with phacoemulsification of the crystalline lens and 25 standalone XEN45 surgery). IOP decreased from 19.9±4.9mmHg at the first visit to a mean of 17.1±5.3 (P=.001) at the sixth month. Drug use required between the first visit and XEN implantation was reduced from 2.1±0.9 to 0.6 (P<.000). A second surgery was necessary in 18 patients (26.6%) in the first 6 months. Conclusions Glaucoma surgery by XEN45 implant, alone or combined with cataract surgery, is an effective and safe procedure for IOP lowering (AU)

Efficacy and safety of the XEN45 implant in glaucoma surgery: Retrospective study of our first 73 cases.

OBJECTIVE: To analyze the results of the Xen45 implant in our hospital center, both in terms of efficacy and safety. METHODS: Observational, retrospective, single-center study of patients undergoing Xen45 surgery at the University Hospital of Jaén between January 1, 2018 and June 31, 2021. RESULTS: A total of 73 patients were implanted with the Xen45 device (48 with in combined surgery with phacoemulsification of the crystalline lens and 25 standalone Xen45 surgery). IOP decreased from 19.9 ±â€¯4.9 mmHg at the first visit to a mean of 17.1 ±â€¯5.3 (P = .001) at the sixth month. Drug use required between the first visit and Xen implantation was reduced from 2.1 ±â€¯0.9 to 0.6 (P < .000). A second surgery was necessary in 18 patients (26.6%) in the first 6 months. CONCLUSIONS: Glaucoma surgery by Xen45 implant, alone or combined with cataract surgery, is an effective and safe procedure for IOP lowering.

A step forward in sustainable pesticide production from Amphidinium carterae biomass via photobioreactor cultivation with urea as a nitrogen source.

This study addresses the problem of replacing nitrate and ammonium with urea as a greener nitrogen source in the mass cultivation of the microalga Amphidinium carterae for the development of amphidinol-based phytosanitary products. To solve this problem, a nuclear magnetic resonance assisted investigation evaluated the effect of nitrogen sources on growth and metabolic profiles in photobioreactors. Urea-fed cultures exhibited growth kinetics comparable to nitrate-fed cultures (µmax = 0.30 day-1, Pbmax = 43 mgL-1day-1). Urea-fed cultures had protein, lipid, and carbohydrate contents of 39.5%, 14.5%, and 42.4%, respectively, while nitrate-fed cultures had 27.9 %, 17.5% and 48.1%, respectively. Metabolomics revealed nitrogen source-dependent metabotypes and a correlation between amphidinols and polyunsaturated fatty acids. The amphidinol-to-nitrogen yield coefficient in urea-fed cultures (135 mg/g) was approximately 2.5 times higher than in nitrate-fed cultures. The potent antiphytopathogenic activity exhibited by extracts from urea-fed cultures underscores the potential of urea as a sustainable nitrogen source in microalgae-based biorefineries.

Life-cycle assessment of a microalgae-based fungicide under a biorefinery approach.

The aim of this work was to perform a life-cycle analysis of the production process of a fungicide based on amphidinols. Two scenarios were evaluated: (1) biorefinery process -biofungicide, fatty acids and carotenoids were considered as co-products-, and (2) biofungicide as only product. Inventory data were taken and scaled-up from previous work on pilot-scale reactors, as well as lab-scale downstream equipment. A yearly production of 22,000 L of fungicide, was selected as the production objective. Despite, photosynthetic biomass is a sink of anthropogenic CO2, harvesting and downstream processing have large carbon footprints that exceed the biomass fixed carbon. Producing the biofungicide resulted in 34.61 and 271.33 ton of CO2e (15 years) for the Scenarios 1 and 2, respectively. Different commercial agricultural fungicides were compared with the microalgal fungicide. A lower impact of the microalgal product for most of the indicators, including carbon footprint, was shown.

Bioactive peptides of whey: obtaining, activity, mechanism of action, and further applications.

Bioactive peptides derived from diverse food proteins have been part of diverse investigations. Whey is a rich source of proteins and components related to biological activity. It is known that proteins have effects that promote health benefits. Peptides derived from whey proteins are currently widely studied. These bioactive peptides are amino acid sequences that are encrypted within the first structure of proteins, which required hydrolysis for their release. The hydrolysis could be through in vitro or in vivo enzymatic digestion and using microorganisms in fermented systems. The biological activities associated with bio-peptides include immunomodulatory properties, antibacterial, antihypertensive, antioxidant and opioid, etc. These functions are related to general conditions of health or reduced risk of certain chronic illnesses. To determine the suitability of these peptides/ingredients for applications in food technology, clinical studies are required to evaluate their bioavailability, health claims, and safety of them. This review aimed to describe the biological importance of whey proteins according to the incidence in human health, their role as bioactive peptides source, describing methods, and obtaining technics. In addition, the paper exposes biochemical mechanisms during the activity exerted by biopeptides of whey, and their application trends.

Treatment of secondary urban wastewater with a low ammonium-tolerant marine microalga using zeolite-based adsorption.

The low tolerance of marine microalgae to ammonium and hyposalinity limits their use in urban wastewater (UWW) treatments. In this study, using the marine microalga Amphidinium carterae, it is demonstrated for the first time that this obstacle can be overcome by introducing a zeolite-based adsorption step to obtain a tolerable UWW stream. The maximum ammonium adsorption capacities measured in the natural zeolite used are among the highest reported. The microalga grows satisfactorily in mixtures of zeolite-treated UWW and seawater at a wide range of proportions, both with and without adjusting the salinity, as long as the ammonium concentration is below the threshold tolerated by the microalgae (6.3 mg L-1). A proof of concept performed in 10-L bubble column photobioreactors with different culture strategies, including medium recycling, showed an enhanced biomass yield relative to a control with no UWW. No noticeable effect was observed on the production of specialty metabolites.

Lemmel syndrome: an extraordinary cause of obstructive jaundice-a case report.

Lemmel syndrome is created by a periampullary duodenal diverticulum. It is identified incidentally in 22% of the population, <10% present with jaundice, pain in the right flank and alteration of bilirubins, transaminases and/or pancreatic enzymes. Its diagnosis and therapeutic management can be carried out successfully with endoscopic retrograde cholangiopancreatography (ERCP), although some cases will require surgical management. We present the case of a 72-year-old male with recurrent obstructive jaundice and suspected choledocholithiasis managed with ERCP, identifying Lemmel syndrome. We recognize the importance of considering this extraordinary cause of obstructive jaundice in order to be able to make a diagnosis and offer timely treatment.

An integrated approach for the efficient separation of specialty compounds from biomass of the marine microalgae Amphidinium carterae.

An amphidinol-prioritized fractioning approach was for the first time developed to isolate multiple specialty metabolites such as amphidinols, carotenoids and fatty acids using the biomass of the marine microalgae Amphidinium carterae. The biomass was produced in a raceway photobioreactor and the exhausted culture media were reused, thus fulfilling sustainability criteria employing a circular economy concept. The integrated bioactive compounds-targeted approach presented here consisted of four steps with which recovery percentages of carotenoids, fatty acids and amphidinols of 97%, 82% and 99 %, respectively, were achieved. The proposed process was proved to be a better extraction system for this microalga than another based on a sequential gradient partition with water and four water-immiscible organic solvents (hexane, carbon tetrachloride, dichloromethane and n-butanol). The proposed process could be scaled-up as a commercial solid-phase extraction technology well-established for industrial bioprocesses.

Intercomparison of Monte Carlo calculated dose enhancement ratios for gold nanoparticles irradiated by X-rays: Assessing the uncertainty and correct methodology for extended beams.

Results of a Monte Carlo code intercomparison exercise for simulations of the dose enhancement from a gold nanoparticle (GNP) irradiated by X-rays have been recently reported. To highlight potential differences between codes, the dose enhancement ratios (DERs) were shown for the narrow-beam geometry used in the simulations, which leads to values significantly higher than unity over distances in the order of several tens of micrometers from the GNP surface. As it has come to our attention that the figures in our paper have given rise to misinterpretation as showing 'the' DERs of GNPs under diagnostic X-ray irradiation, this article presents estimates of the DERs that would have been obtained with realistic radiation field extensions and presence of secondary particle equilibrium (SPE). These DER values are much smaller than those for a narrow-beam irradiation shown in our paper, and significant dose enhancement is only found within a few hundred nanometers around the GNP. The approach used to obtain these estimates required the development of a methodology to identify and, where possible, correct results from simulations whose implementation deviated from the initial exercise definition. Based on this methodology, literature on Monte Carlo simulated DERs has been critically assessed.

Long-term biofouling formation mediated by extracellular proteins in Nannochloropsis gaditana microalga cultures at different medium N/P ratios.

Biofouling represents an important limitation in photobioreactor cultures. The biofouling propensity of different materials (polystyrene, borosilicate glass, polymethyl methacrylate, and polyethylene terephthalate glycol-modified) and coatings (two spray-applied and nanoparticle-based superhydrophobic coatings and a hydrogel-based fouling release coating) was evaluated by means of a short-term protein test, using bovine serum albumin (BSA) as a model protein, and by the long-term culture of the marine microalga Nannochloropsis gaditana under practical conditions. The results from both methods were similar, confirming that the BSA test predicts microalgal biofouling on surfaces exposed to microalgae cultures whose cells secrete macromolecules, such as proteins, with a high capacity for forming a conditioning film before cell adhesion. The hydrogel-based coating showed significantly reduced BSA and N. gaditana adhesion, whereas the other surfaces failed to control biofouling. Microalgal biofouling was associated with an increased concentration of sticky extracellular proteins at low N/P ratios (below 15).

Improved extraction of bioactive compounds from biomass of the marine dinoflagellate microalga Amphidinium carterae.

The extraction of three families of compounds (carotenoids, fatty acids and amphidinols) from the biomass of two strains of Amphidinium carterae (ACRN03 and Dn241EHU) was improved by tuning cell disruption and solvent extraction operations. The extraction of carotenoids was evaluated using alkaline saponification (0%-60% KOH d.w.) at different temperatures (25-80 °C). High levels of carotenoids were obtained at 60 °C using freeze-dried biomass, not subjected to cell disruption methods. The ACRN03 strain required 20% KOH whereas the Dn241EHU strain did not require saponification since carotenoid degradation was observed. The extraction efficiencies were determined with a wide range of pure solvents and mixtures thereof. Two empirical non-linear equations were used to correlate extraction percentages for each family of compounds with the Hildebrand solubility parameter (δT) and the polarity index of the solvents (PI). Thresholds of δT and PI of around 20 MPa1/2 and 6, respectively, were determined for the extraction of amphidinols, consistent with antiproliferative activity measurements.

Brain alterations in GABA, glutamate and glutamine markers after chronic atrazine exposure in the male albino rat.

Atrazine (ATR; 2-chloro-4-ethylamino-6-isopropylamino-s-triazine) is an herbicide widely used to kill annual grasses and broadleaf weeds in crops such as corn, sorghum, and sugarcane. Studies in rodents have shown that chronic ATR exposure is associated with alterations in the nigrostriatal dopaminergic pathway such as hyperactivity, decreased striatal dopamine levels, and diminished numbers of tyrosine hydroxylase positive cells in substantia nigra pars compacta. However, the effects of ATR on neurotransmitters such as GABA and glutamate have been scarcely studied. To evaluate the impact of ATR on motor and anxiety tasks, tissue levels of GABA, glutamate, glutamine, and extracellular and potassium-evoked release of glutamate in the striatum, we daily exposed Sprague-Dawley male rats to 1 or 10 mg ATR/kg of body weight for 12-14 months. As previously reported, chronic ATR exposure causes hyperactivity in the group exposed to 10 mg ATR/kg and increased anxiety in both groups exposed to ATR. GABA, glutamate, and glutamine levels were differentially altered in brain regions related to nigrostriatal and mesolimbic systems, the amygdala, and the prefrontal cortex. The groups exposed to 10 mg ATR/kg showed increased extracellular levels and release of glutamate in the striatum. These neurochemical alterations could underlie the behavioral changes observed in rats. These results indicate that chronic exposure to the herbicide ATR disrupts the neurochemistry of several brain structures and could be a risk factor for the development of neurodegenerative diseases.

Tendinopatía cálcica: etiopatogenia y evaluación por imágenes / Calcific tendinitis: aetiopathogenesis and imaging evaluation

Resumen: La tendinopatía cálcica es causada por el depósito patológico de cristales de hidroxiapatita de calcio en los tendones y es una causa común de dolor en las articulaciones. Afecta más frecuentemente al hombro y la cadera, con hallazgos característicos en imágenes; sin embargo, cualquier tendón puede estar involucrado. Ocasionalmente, la tendinopatía cálcica puede simular patología agresiva, como infección o neoplasia, especialmente en RM. Fisiotpatológicamente, las calcificaciones provendrían de una diferenciación anormal de las células madre del tendón, que comienzan a producir calcio, aunque todavía no es del todo claro. Los radiólogos deben estar familiarizados con los hallazgos de las imágenes para distinguir la tendinopatía cálcica de procesos más agresivos. La aspiración y lavado guiado bajo ecografía es una técnica útil realizada por el radiólogo para el tratamiento de casos sintomáticos. La familiaridad con estos procedimientos y su apariencia en imágenes es un aspecto importante en el manejo de esta enfermedad. El propósito de esta revisión es analizar la etiopatogenia de la tendinopatía cálcica, la evaluación con imágenes en los sitios de presentación más comunes y también en los menos frecuentes, así como el papel que desempeña la ecografía en el tratamiento de la patología.

Abstract: Calcific tendinitis is caused by abnormal deposition of calcium hydroxyapatite crystals in tendons and is a common cause of joint pain. The disease typically affects the shoulder and hip, with characteristic imaging findings; however, any tendon can be involved. Occasionally, calcific tendinitis can mimic aggressive disorders, such as infection and neoplasm, especially on MRI. Apparently, the calcifications come from an abnormal differentiation of the tendon stem cells, which begin to produce calcium. Radiologists should be familiar with the imaging findings to distinguish calcific tendinitis from more aggressive processes. Image-guided percutaneous needle aspiration is a useful technique performed by the radiologist for the treatment of symptomatic cases. Being familiar with these processes and their imaging appearance is an important aspect in the management of this common disease. The purpose of this review is to analyze the pathogenesis of calcium tendinopathy, the evaluation of images in both the most common and less frequent presentation sites, as well as the role played by ultrasound in the treatment of pathology.

Tuning the thermoelectric response of silicene nanoribbons with vacancies.

In this work, we present a thorough study of the thermoelectric properties of silicene nanoribbons in the presence of a random distribution of atomic vacancies. By using a linear approach within the Landauer formalism, we calculate phonon and electron thermal conductances, the electric conductance, the Seebeck coefficient and the figure of merit of the nanoribbons. We found a sizable reduction of the phonon thermal conductance as a function of the vacancy concentration over a wide range of temperature. At the same time, the electric properties are not severely deteriorated, leading to an overall remarkable thermoelectric efficiency. We conclude that the incorporation of vacancies paves the way for designing better and more efficient nanoscale thermoelectric devices.

Changes in the GN/GCof the M segment show positive selection and recombination of one aggressive isolate and two mild isolates of tomato spotted wilt virus.

We isolated and compared three tomato spotted wilt virus (TSWV) isolates from lettuce (TSWV-Let), pepper (TSWV-Pep), and tomato (TSWV-Tom) from central Mexico to determine their ability to infect a set of eighteen differential plant species from seven families. TWSV-Let was an aggressive isolate with the ability to infect up to 52% of the differential plants, including maize, under greenhouse conditions. The nucleotide (nt) sequences of the three isolates are more than 90% similar in the M and S RNA segments. In the M segment of the TSWV-Let isolate, we detected nt changes in their intergenic region (IGR) and, in the Gc gene, a region containing a recombination site, as well as a synapomorphy associated with one of three sites under positive selection with a change in one aa residue (a cysteine-to-valine mutation). We speculate on the association of these features in the Gc gene with host selection, adaptation, aggressiveness, and ability to infect maize plants.

Stopping power of water for carbon ions with energies in the Bragg peak region.

The stopping power of liquid water was measured for carbon ions with energies in the Bragg peak region using the inverted Doppler shift attenuation method. Among the semiempirical data, the results of this work agree best with the data recommended in the Errata and Addendum of ICRU Report No. 73, which is based on an I value of 78 eV for water. The agreement was worse when the present results were compared to the newer recommendation of the ICRU published in ICRU Report No. 90. The srim code seems to slightly overestimate the stopping power of water for carbon ions above 3 MeV. A semiexperimental stopping power of water for α particles was derived from the present results using the theoretical ratio between the stopping powers of water for carbon ions and α particles computed by means of the casp code. These values agree well with the experimental data for α particles within the uncertainties.

Estudio antropométrico de la glena humana en una población española normal / Anthropometrical study of the human glenoid in a normal Spanish population

Objetivo: El objetivo de este estudio es evaluar el tamaño de la glena en una población española normal, compararla con resultados previos en otras poblaciones y relacionarlo con los tamaños de implante que se comercializan para la artroplastia invertida de hombro. Material y métodos: Estudio antropométrico de la glena humana utilizando tomografías computarizadas de 154 pacientes con edades superiores a 30 años, realizados entre enero de 2015 y diciembre de 2017. Se valoran tomografías computarizadas de hombro con cortes de 2mm de grosor y 0mm de intervalo entre cortes, en algoritmo óseo y de partes blandas, realizándose reconstrucción 3D sobre la cual se obtienen mediciones de longitud y anchura de la glena. El punto superior de la glena se determinó en la zona superior del ovoide de la glena, en el tubérculo supraglenoideo, justo por debajo del reborde circunferencial que rodea la glena. El punto inferior se determinó como el punto más alejado del punto superior en el contorno de la glena, a nivel superior del reborde circunferencial que rodea la glena. Los puntos anterior y posterior fueron determinados como los extremos del eje transversal mayor en un plano perpendicular al eje superoinferior, por dentro del reborde circunferencial que rodea la glena. Las diferencias entre sexos, edad, altura, peso y relaciones de tamaños fueron evaluados. Resultados: La glena tiene un eje longitudinal medio de 28,78mm y una anchura de 20,27mm. Los valores del tamaño de la glena son significativamente diferentes en hombres y mujeres, siendo mayor en hombres. El tamaño de la glena está bien correlacionado con la estatura del paciente, existiendo una asociación positiva entre la estatura y la longitud y anchura de la superficie glenoidea. Las metaglenas circulares disponibles hoy en el mercado presentan tamaños no inferiores a 24-25mm de diámetro. Conclusión: La población del sur de España presenta un tamaño de la superficie glenoidea inferior a la población americana y semejante a la cohorte asiática. Los datos antropométricos expresados pueden ser útiles para la elección de la metaglena más apropiada en la población del sur de España

Objective: To evaluate the size of the glenoid in a southern Spanish population, to compare it with previous results from other populations and determine the size of the implants that are marketed for shoulder arthroplasty. Material and methods: Between January 2015 and December 2017, an anthropometrical study of the human glenoid was performed using computed axial tomography scans (CT) of 154 patients over 30 years old. The glenoid dimensions were analysed 3-dimensionally using 2mm interval thicknesses, determining the average height and width of the glenoid. The upper point of the glenoid geometry was determined as the supraglenoid tubercle of the ovoid glenoid surface, where the long head of the biceps tendon is thought to originate. The lower point was then positioned at the furthest point from the upper point on the glenoid contour. Anterior and posterior points were determined such that the 3-dimensional anterior-posterior distance was maximized on the plane perpendicular to the upper-lower axis. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were also evaluated. Results: The glenoid had an average height of 28.78mm and width of 20.27mm. The values were significantly different between the men and the women, being greater in the men. The glenoid size is well correlated with the patient's size. Direct correlations exist between the glenoid height and width and the glenoid size and the patient's height. The available metaglenoids currently on the market are no bigger than 25-24mm. Conclusion: In comparison, the southern Spanish population have a glenoid size similar to the Caucasian population, but smaller than that of the American population. The data shown could be useful to improve the design of shoulder prostheses for the southern Spanish population

Anthropometrical study of the human glenoid in a normal Spanish population. / Estudio antropométrico de la glena humana en una población española normal.

OBJECTIVE: To evaluate the size of the glenoid in a southern Spanish population, to compare it with previous results from other populations and determine the size of the implants that are marketed for shoulder arthroplasty. MATERIAL AND METHODS: Between January 2015 and December 2017, an anthropometrical study of the human glenoid was performed using computed axial tomography scans (CT) of 154 patients over 30 years old. The glenoid dimensions were analysed 3-dimensionally using 2mm interval thicknesses, determining the average height and width of the glenoid. The upper point of the glenoid geometry was determined as the supraglenoid tubercle of the ovoid glenoid surface, where the long head of the biceps tendon is thought to originate. The lower point was then positioned at the furthest point from the upper point on the glenoid contour. Anterior and posterior points were determined such that the 3-dimensional anterior-posterior distance was maximized on the plane perpendicular to the upper-lower axis. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were also evaluated. RESULTS: The glenoid had an average height of 28.78mm and width of 20.27mm. The values were significantly different between the men and the women, being greater in the men. The glenoid size is well correlated with the patient's size. Direct correlations exist between the glenoid height and width and the glenoid size and the patient's height. The available metaglenoids currently on the market are no bigger than 25-24mm. CONCLUSION: In comparison, the southern Spanish population have a glenoid size similar to the Caucasian population, but smaller than that of the American population. The data shown could be useful to improve the design of shoulder prostheses for the southern Spanish population.

Tunable Spin-Polarized Edge Currents in Proximitized Transition Metal Dichalcogenides.

We explore proximity-induced ferromagnetism on transition metal dichalcogenides (TMDs), focusing on molybdenum ditelluride ribbons with zigzag edges, deposited on ferromagnetic europium oxide (EuO). A tight-binding model incorporates exchange and Rashba fields induced by proximity to EuO or similar substrates. For in-gap Fermi levels, electronic modes in the nanoribbon are localized along the edges, acting as one-dimensional (1D) conducting channels with tunable spin-polarized currents. TMDs on magnetic substrates can become very useful in spintronics, providing versatile platforms to study the proximity effects and electronic interactions in complex 1D systems.