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El 11 de febrero de 1982 marcó el inicio oficial de un sueño que había crecido entre el clero, las comunidades religiosas y diversas personas de la comunidad del Oriente antioqueño con el beneplácito de las administraciones municipales. Mons. Alfonso Uribe Jaramillo permitió materializar este anhelo firmando en la fecha indicada el decreto de fundación de esta universidad. Es necesario señalar también que esta obra educativa fue creada en el año de las bodas de plata de la Diócesis de Sonsón-Rionegro como una expresión de generosidad con el pueblo del Oriente antioqueño y como signo del crecimiento, empuje y compromiso con el progreso de la región. Sin duda, una oportuna iniciativa educativa para el servicio evangelizador de esta Iglesia particular que se esfuerza por leer y atender los signos de los tiempos de un territorio. “Con esta Universidad queremos glorificar al Señor y a su Madre, servir al hombre que constituye nuestra mayor riqueza y contribuir modestamente a la restauración y al progreso integral de nuestra patria”. Estas palabras de Mons. Alfonso Uribe Jaramillo, en su discurso inaugural del 4 de abril de 1983, retratan su preocupación de pastor, que ordena toda su acción a la glorificación de Dios y al servicio evangelizador de la Iglesia, en este caso, para ofrecer desde la educación una formación integral a las personas y las comunidades que permita, además, profesionales idóneos a la sociedad y a la patria.

Tinea capitis is an uncommon infection in adults, and predominantly affects women and the elderly with hormonal disorders and immunosuppression. Clinical features are often polymorphic and atypical. A kerion celsi case in an elderly female patient with type 2 diabetes mellitus and menopause is presented. The diagnosis was established by direct examination and the isolation of Trichophyton tonsurans in culture and typified by microculture. Treatment with prednisone and itraconazol was very successful. Recognizing the presentation of tinea capitis in adults will help clinicians to avoid delay in the diagnosis, awareness of the risk factors and provide early treatment to minimize sequelae of the disease.

Quantum drift diffusion corrections, models for the one- and two-dimensional density of states, a non-local model for source-to-drain tunneling, and a simple ballistic mobility model are jointly used to simulate I D V GS -characteristics of scaled III-V-channel nFETs. The sub-threshold swing of double-gate ultra-thin-body and gate-all-around nanowire geometries are extracted for different gate lengths, and the semi-classical results are compared with those from the quantum transport simulator QTx. The low-dimensional density of states in combination with the ballistic mobility yields an overall good agreement with the QTx transfer curves after the onset of inversion and decreases I ON by two orders of magnitude in comparison to the simulation with a large diffusive mobility. It is shown that source-to-drain tunneling sets a limit to scaling at a gate length of about 10 nm due to the degradation of the sub-threshold swing. Simulating this effect with a low-dimensional density of states reveals inconsistencies. They are attributed to the tunneling model, which had been derived for a three-dimensional electron gas.

TCAD models of the ballistic mobility are developed where the mean ballistic velocity is not a fitting parameter, but a function of either the quasi-Fermi potential or the density. In the first case, a local version can be derived which is more robust when used together with a model for source-to-drain tunneling. The second form conserves the thermionic ballistic current and better matches the on-currents of short-channel FETs obtained from a quantum-transport solver, in particular at low source-drain bias. It requires the iterative extraction of the top-of-the-barrier density. This is the only non-local remnant of the hydrodynamic term in the balance equation for the mean velocity which is discarded in all commercial 2D/3D device simulators. The ballistic mobility, used with the Matthiessen rule, substitutes for this term and prevents that the drift-diffusion current diverges in the limit of zero gate length. The numerical integration of the models with the TCAD simulator S-Device is set out, and simulated transfer characteristics of In0.53Ga0.47As double-gate ultra-thin-body FETs with gate lengths ranging from 7 nm to 40 nm are compared with the corresponding quantum-transport results. It is shown that under conditions of dominant source-to-drain tunneling, the concepts of local quasi-Fermi potential and mean ballistic velocity break down. Suggestions for non-local modifications of both the mobility and tunneling models are given that would allow to use the same setup for all gate voltages from deep sub-threshold to deep inversion.

The purpose of this study was to compare the efficacy of galactose and high initial ferrous iron concentrations as inducers for extracellular polymeric substances (EPS) production in planktonic cells of Leptospirillum ferrooxidans and to study cell attachment to a mineral surface in comparison to cells not exposed to such substances. L. ferrooxidans was successfully adapted to grow in a modified 9K medium at different concentrations of galactose (0.15, 0.25, 0.35%) and also at different initial ferrous iron concentrations (18, 27, 36 g/L), which are higher than 9K medium (9 g/L). The experiments were done in shake flasks using ferrous iron as energy source. A comparison of growth kinetics showed a decreasing of maximum specific growth rate of L. ferrooxidans with increasing concentrations of galactose and initial ferrous iron. The EPS content increased and the EPS chemical composition (relative abundance of carbohydrates, proteins and ferric iron) changed with increasing concentrations of galactose and initial ferrous iron. Results revealed that the increase of the bacterial adhesion rather depended on the chemical composition, i.e. relative abundance of the constituents of the EPS, than on the total amount of EPS. The EPS induced by galactose seemed to be “stickier” than the one induced by ferrous iron. Based on the results of this study it is proposed that galactose might enhance biooxidation processes which needs to be tested in future studies.

Las aplicaciones de tecnologías nucleares podrían tener un gran impacto en el nuevo escenario de cambio climático que está afectando la adaptabilidad de las especies nativas y exóticas en el país, lo que se manifiesta en la aparición de enfermedades y plagas, como es el caso de la mortalidad en poblaciones naturales de Araucaria araucana (Molina) K. Koch, en la significativa merma de productividad de las plantaciones de Eucalyptus globulus Labill., en la vulnerabilidad de especies como el ruil (Nothofagus alessandrii Espinosa) y otras. La aplicación de bajas dosis de radiación gamma “hormesis”, genera alteraciones metabólicas y fisiológicas, mejora la germinación en las semillas y también el crecimiento inicial de las plantas. Aunque se sabe poco sobre la naturaleza básica de este fenómeno, existe una relación entre hormesis y efectos epigenéticos que se manifiestan como respuestas adaptativas en las especies irradiadas. El presente trabajo efectúa una revisión del estado del arte de estas tecnologías y sus posibles aplicaciones al ámbito de la conservación y el mejoramiento genético forestal de especies nativas y exóticas de rápido crecimiento en Chile.

Ultrathin-body (UTB) III–V channel MOSFETs are known to suffer from the floating body effect which turns on a parasitic bipolar junction transistor (BJT) and increases the off-state leakage current. This paper presents a TCAD simulation study of UTB In0.53Ga0.47As n-channel MOSFETs with nanowire and planar device geometry, each with different gate lengths ( ${L}_{G}$ ) ranging from 13 to 300 nm. A single set of parameters results in good agreement with measured transfer characteristics of all six different device geometries. The impact of band-to-band tunneling (BTBT), trap-assisted tunneling (TAT), and the electrostatic effect of traps at the buried-Al2O3/InGaAs interface has been deconvoluted during the TCAD analysis. It is found that the turn-on of the parasitic BJT is mainly caused by the combined effect of BTBT at the channel–drain junction and TAT at the gate-oxide/drain overlap. Furthermore, it is revealed that traps at the buried-Al2O3/InGaAs act as a backgate and degrade the subthreshold swing of the planar MOSFETs. The off-state leakage due to the parasitic BJT could be minimized with the help of an oxide spacer between HfO2 and InGaAs drain and by introducing a dopant grading at the source–channel and the drain–channel interfaces.

Introduction: Prolonging of the grafts permeability used in coronary bypass is a constant challenge. Objective: To compare anatomical and functional human saphenous veins (VSH) extracted “No touch” (NT) technique vs conventional technique (TC). Materials and Methods: Experimental study. VSH dissected with CT and NT in the Regional Hospital of Antofagasta cardiac surgery ward. VSH samples were sectioned into 3 mm rings and preserved in isolated organs chambers with Krebs-Ringer solution. To evaluate the vasomotor activity, norepinephrine (10-6M), papaverine (10-4M), acetylcholine (10-6M) and sodium nitroprusside (10-5M) was administered. A segment of samples was fixed in 10% formalin, processed and histological analyzed under light microscopy technique with hematoxylin-eosin, Verhoeff and orceina. Statistical analysis was performed using the Prism software Graphad. Results: Vascular Reactivity: norepinephrine-induced vasoconstriction was significantly higher in the group rings NT vs TC (p < 0.0001). Vasodilation was higher with papaverine and acetylcholine in the NT group (p < 0.004) and (p < 0.0003), respectively. Morphometric study: The NT group presented muscularis (0.755 vs 0.680 mm), adventitious (0.5600 vs 0.4663 mm), and total wall (1.344 vs 0.962 mm) thicker than the TC group. No significant differences in vasa vasorum number identified. Conclusion: The NT group vasoconstrictor and vasodilator responds significantly better. Results correlate with morphometric differences. Key words: saphenous vein; coronary artery bypass; pedicled ‘no-touch’; vascular damage.

In a mine owned by the company Orenas S.A. (Equador), a biooxidation process for gold recovery has been developed. Refractory gold ore was crushed, milled and 500 ton of flotation concentrate was agglomerated by coating a support rock. This was piled up on a liner and the biooxidation process in the heap of 35x25x6 m3 was run for approximately 150 days. The oxidized material was subsequently removed for further processing. An outcrop allowed for depth dependent sampling of altogether 36 samples at three sites over the complete depth of 6 m. The fine fraction was removed from the host rock and sent to the laboratory for analysis of the microbial community. The pH ranged between 2.2 and 2.9. Total cell counts determined via counting under a fluorescence microscope after SYBR Green staining indicated a high microbial colonialization of the heap in all depths between 106 to 109 cells per g concentrate, however the highest cell numbers were mainly found in the upper 50 cm. Most-probable-number determination of living, acidophilic iron (II)-oxidizers for one site also revealed a decrease of cell numbers with depth (between 104 to 108 cells per g concentrate). Further molecular analyses of the community composition based on extracted DNA and 16S rRNA gene analyses by TRFLP and qPCR revealed a complex archaeal and bacterial community within the heap. It can be stated that an active community of acidophiles runs the biooxidation process in all sampled parts of the heap.

The presence of extracellular polymeric substances (EPS) and their relevance for biofilm formation on the mineral surface for a variety of microbial species play a fundamental role in the degradation of sulfide ores. EPS production is associated with induction or auto induction mechanisms as a response of bacteria to environmental conditions. In this study, we tested galactose as an inducer of EPS production in planktonic cells of Acidithiobacillus thiooxidans DSM 14887T and their adherence to polymetallic mineral surfaces. Cells of At. thiooxidans were first adapted to grow at different concentrations of galactose (0.15, 0.25, 0.35%) using a modified 9K liquid medium and elemental sulfur as the energy source. In order to determine EPS production, the microorganisms were grown for 24 hours at different concentrations of galactose. Our results showed a cell adherence of 84% cells within 4 hours in presence of 0.15% galactose compared to 70% without galactose. The optimal concentration of galactose for maximal EPS production was 0.25% and for the attachment of cells it was 0.15%. Higher galactose concentrations inhibited microbial growth and decreased the number of cells attached to the mineral. While with a small amount of galactose in the culture media can shift the balance between sessile cells and planktonic cells, generating an increase in adhesion and therefore a possible increase of the bioleaching rate.

The enhanced green fluorescent protein (eGFP) is one of the most employed variants of fluorescent proteins. Nonetheless little is known about the oxidative modifications that this protein can undergo in the cellular milieu. The present work explored the consequences of the exposure of eGFP to free radicals derived from γ-radiolysis of water, and AAPH thermolysis. Results demonstrated that protein crosslinking was the major pathway of modification of eGFP towards these oxidants. As evidenced by HPLC-FLD and UPLC-MS, eGFP crosslinking would occur as consequence of a mixture of pathways including the recombination of two protein radicals, as well as secondary reactions between nucleophilic residues (e.g. lysine, Lys) with protein carbonyls. The first mechanism was supported by detection of dityrosine and cysteine-tyrosine bonds, whilst evidence of formation of protein carbonyls, along with Lys consumption, would suggest the formation and participation of Schiff bases in the crosslinking process. Despite of the degree of oxidative modifications elicited by peroxyl radicals (ROO•) generated from the thermolysis of AAPH, and free radicals generated from γ-radiolysis of water, that were evidenced at amino acidic level, only the highest dose of γ-irradiation (10 kGy) triggered significant changes in the secondary structure of eGFP. These results were accompanied by the complete loss of fluorescence arising from the chromophore unit of eGFP in γ-irradiation-treated samples, whereas it was conserved in ROO•-treated samples. These data have potential biological significance, as this fluorescent protein is widely employed to study interactions between cytosolic proteins; consequently, the formation of fluorescent eGFP dimers could act as artifacts in such experiments.

Acidithiobacillus ferrooxidans, together with other microorganisms, has an important role on biohydrometallurgical processes. Such bacterium gets its energy from the oxidation of ferrous ion and reduced sulfur; in the first case, the accumulation of ferric ion as a product can cause its inhibition. It is known that the extracellular polymeric substances (EPS) may have an important role in the adaptation and tolerance to diverse inhibiting conditions. In the present study, it was tested how D-galactose can influence the production of extracellular polymeric substances (EPS) on At. ferrooxidans by evaluating at the same time its biooxidant activity and capacity to tolerate high concentrations of ferric ion. The visualization and quantification of EPS was done through a confocal laser scanning microscope (CLSM). The results show that at low cellular concentrations, the D-galactose inhibits the microbial growth and the biooxidation of ferrous ion; however, when the quantity of microorganisms is high enough, the inhibition is not present. By means of chemostat tests, several concentrations of D-galactose (0; 0.15; 0.25; and 0.35%) were evaluated, thus reaching the highest production of EPS when using 0.35% of this sugar. In cultures with such concentration of D-galactose, the tolerance of the bacterium was tested at high concentrations of ferric ion and it was compared with cultures in which sugar was not added. The results show that cultures with D-galactose reached a higher tolerance to ferric ion (48.15 ± 1.9 g L–1) compare to cultures without adding D-galactose (38.7 ± 0.47 g L–1 ferric ion). Also it was observed a higher amount of EPS on cells growing in the presence of D-galactose suggesting its influence on the greater tolerance of At. ferrooxidans to ferric ion. Therefore, according to the results, the bases of a strategy are considered to overproduce EPS by means of At. ferrooxidans in planktonic state, so that, it can be used as a pre-treatment to increase its resistance and tolerance to high concentrations of ferric ion and improve the efficiency of At. ferrooxidans when acting in biohydrometallurgical processes., Graphical Abstract Planktonic cells of At. ferrooxidans produce EPS only when grown in the presence of D-galactose as can be seen in the CLSM images. Cells having EPS on their surface can tolerate higher iron concentrations compare to cells without a layer of EPS surrounding them.

Bioleaching is a process that involves acidophilic and chemolithoautotrophic microorganisms such as Acidithiobacillus ferrooxidans. It is known that At. ferrooxidans undergoes growth and biooxidation inhibition due to ferric ion accumulation. The objective of this study was to establish a strategy to adapt planktonic cells of At. ferrooxidans to high total iron concentrations in two steps and correlate their tolerance to ferric ion with extracellular polymeric substances (EPS) accumulated on the cell surfaces. The first step consisted in carrying out pulse additions of ferrous ion and the second one comprised consecutive sub-cultures with the objective of improving the biooxidation capacity of the bacteria at different concentrations of total iron (18, 27 and 36 g L−1). Visualization and quantification of EPS were assessed through confocal laser scanning microscopy (CLSM). The adapted cells exhibited an increasing volumetric productivity of ferric ion and cell density according to the total iron concentration when adapted and superior to what was showed by non-adapted cells of the control cultures. It was observed that cells adapted to higher total iron concentration displayed the greatest amount of EPS accumulated on their surfaces. Maximum tolerance to total iron of cells adapted to 36 g L−1 was 20% greater than non-adapted cells of the control culture. The experimental evidence points out that EPS accumulation by planktonic At. ferrooxidans was a determining factor for its tolerance to high iron concentrations. Moreover, it is thought that these results could be important in order to increase the efficiency in processes such as bioleaching and biooxidation.

A local TCAD model of the ballistic mobility is proposed that can be used in quantum drift-diffusion (QDD) simulations. It can be combined with models for density gradient correction and source-to-drain tunneling (STDT). These quantum effects strongly affect the transfer characteristics of In 0.53 Ga 0.47 As double-gate ultra-thin-body (DG UTB) FETs with ultra-short channels.

The mining districts located in the western mountain range in the south of Ecuador have gold minerals with refractory characteristics, which do not allow gold recovery by traditional methods used in Ecuador. Therefore, it is necessary to apply some technology that permits to obtain greater metal recovery. Bio-oxidation, as treatment of refractory ores that contain low grade of gold, offers an economic and sustainable alternative for this purpose. The objective of this research was to evaluate the effect of particle size, pulp density and concentration of inoculum and inducer (Fe+2) on the bio-oxidation of refractory gold minerals in order to maximize gold recovery of the bioleached minerals by means of a cyanidation process. The microbial consortium used in this work was collected and isolated from the Portovelo mining district corresponding mostly toAcidithiobacillus ferrooxidansandLeptospirillum ferrooxidansspecies. The Eh, final concentration of ferric ion, total iron and sulfates were measured. Finally, the bio-oxidized material was tested using cyanidation to determine the gold recovery. The results after the cyanidation tests showed that the highest gold recovery was obtained when the bio-oxidation step was conducted with 68-91 µm particle size, 15% pulp density, 20% v/v inoculum and 2 g/L of Fe2+as inducer. At those conditions, gold recovery was 68% compared to 26% obtained when no bio-oxidation step was performed, demonstrating that this process was favorable compared with traditional gold recovery processes

The synthesis of (η3:η3-TME)[Co(CO) 3]2 (1) was achieved using 2,3-bis(bromomethyl)-1,3- butadiene (TMEBr2) as the tetramethyleneethane (TME) ligand precursor and Na[Co(CO)4]. Solution NMR studies suggested an η3:η3-configuration, which has been confirmed in the solid state by single-crystal X-ray diffraction studies. The series of complexes (η3:η3-TME)[Co(CO)2PR 3]2 (R = Me, 2; R = Et, 3; R = n-Bu, 4; R = Ph, 5; R = OPh, 6) were also synthesized by ligand exchange reactions, demonstrating that only one carbonyl may be exchanged for a phosphine group on each metal center. The η3:η3-configuration of the tetramethyleneethane ligand in these complexes was determined by crystallographic studies. The effect of the electron-donating properties of PR3 was studied by cyclic voltammetry (CV) and infrared spectroscopy. The greatest degree of electron donation was seen when R = Et (3) and lowest when R = Ph (5) or R = OPh (6). Electronic communication between the metal centers was observed by CV. The chemical oxidation of 1 resulted in a highly unstable species that decomposed to {[(CO)2Co]TME[Co(CO) 3]}+[BF4]- (1+d), determined by its crystal structure. The synthesis of (η4: η4-TME)[CoCp*]2 (7) has been achieved using a dipotassium 2,3-bis(methylene)-1,3-butanediyl (TMEK2) synthon. NMR studies suggested that 7 adopts an unusual η4:η4- configuration, which was confirmed with the aid of crystallographic studies. DFT calculations were performed in order to rationalize the bonding for 1, 7, and hypothetical (η4:η4-TME)[CoCp]2 (8). The large energy difference between the two coordination isomers 1 and 1a confirmed the η3:η3-configuration. For isomers 7/7a and 8/8a, the energy difference between the two isomers (ca. 15 kJ mol -1) is in favor of the η4:η4- configuration. For complexes 1+ and 8+, the calculations suggested complete delocalization on the system when one electron was removed. © 2010 American Chemical Society.

The present study was aimed at carrying out a survey on the knowledge and acceptance level of food irradiation. The work was carried out in Santiago, Chile. As an above-average level country in South and Central America, the results may give an indication about the situation in other countries. The survey could also provide an indication about the impression of the public regarding the international “Radura” symbol, indicating on a food product that has been irradiated. A total of 497 persons were interviewed. Among the interviewed people, 76.5% did not know that irradiation could be used as a method for food preservation; 46% expressed their belief that irradiated food means the same as radioactive food. Nevertheless, 91% claimed that they would become consumers of irradiated food if they knew that “irradiated” is not “radioactive” and that proper irradiation enhances food safety; 95.8% of the interviewed persons were not familiar with the “Radura” symbol. However, 55.8% expressed their opinion that they would buy irradiated food because of the symbol, affirming that the “Radura” symbol transmits the sensation of confidence and safety.

Metal-metal interactions have been studied in a large number of different carbon bridged homobinuclear complexes. The bridging ligands considered are sp2- and/or sphydrocarbon chains, bridging aromatic rings linked directly as fulvalene and fulvalene-like; and fused aromatic spacers as indenyl, permethylpentalene-diide, and permethylfluorene between others. The efficiency of the intramolecular electronic communication between the metal centers depends on the nature of the metals, their oxidation state, the strength of the coupling between the acceptor and the donor sites, the ancillary ligands and the structure of the bridging ligand. Generally, the electronic communication decreases with increasing the distance between the donor and the acceptor sites. Also, electronic coupling and other donor-acceptor interactions are stronger through alkene than alkyne bridges. Bridging aromatic rings and fused aromatic linkers are also suitable spacers to promote metal-metal interactions. However, if their planarity is broken due to steric effects, the loss of aromaticity decreases the electronic communication between the metal centers. Metal-metal interactions have been mainly evaluated on the basis of IR, EPR, optical, and electrochemical measure-ments of the mixed-valence species. According to these data, the numerous complexes presented on this review have been categorized following the Robin and Day classification. © 2010 American Chemical Society.

We report the first mechanically flexible amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) vertical thin-film transistors (VTFTs) with 500 nm channel length, fabricated on a freestanding plastic foil, using a low temperature process 107 and a threshold voltage of 2.2 V. We demonstrate full device functionality down to 5 mm bending radius, even after 1000 bending cycles. These results proof that VTFTs are feasible for realizing compact and bendable electronic systems.

Quadruple helical structures ar assembled around a tetranuclear cubane structure using four chiral tridentate ligands andtwo ligands coordinating diagonally across a face. The chiralityof the helix is controlled by that of the ligand. Meso-structures may also be generated

This article presents image processing methods for biological Images which show kind of cells. The main difficulty of processing these images was the presence of noise in the images and the limitation of losing pixels during the binarization of the images. Neighborhood algorithm, such as the Wiener filter was used for noise removal. In addition to this, a normalization of the background was performed on the image before the binarization of the image and finally the application of morphological operations for suppressing the remaining effects of the noise on the original image.

The present work develops a multibody dynamical model of a planar biped robot called Rabbit, the same that considers external forces which act at the moment of the ground-feet contact. Moreover, the ground-feet contact forces where modeled. The multibody dynamical model of Rabbit was implemented in Robotran, software that generated symbolic files of the dynamical equations of the model in Matlab syntax. These dynamical equations and the ground-feet contact external forces were implemented in a Simulink model for simulation purposes. The model was validated though a Simulink implementation of the torque generator and control blocks of the real robot. The results showed that the model required adequate torques, which must be generated on the basis of designed trajectories, assuring the dynamical stability of the gait. In addition to this, the adequate frictional forces acting on the feet of the model proved to prevent the robot from slipping on the walking surface and falling. In conclusion, for achieving a stable gait, an adequate dynamic model that assures stability is not only necessary, but a correct design that could be fitted for the torque generator of the real robot is necessary as well.

The mining district of Zaruma-Portovelo of southern Ecuador is a deposit of polymetallic sulfides worked since 1908. Currently the small traditional mining operation processes 1800 tons of ore a day, generating environmental waste that is accumulated and systematically discharged into the Calera and Amarillo Rivers. In this watershed area of Puyango-Tumbes, where samples were taken and subjected to gravimetric concentration, a mineralogical analysis of the concentrate was made. Samples of sediments taken from areas of weathered mining shafts were used to isolate native microorganisms for subsequent molecular and physiological characterization. The mineral concentrate contains 66.63 % of pyrite, 175 ppm Ag and 6.9 ppm Au (with 80 % of refractory gold). This mineral was subjected to biooxidation by the isolated native organisms. In experiments with pulp density of 10%, the solubility of the sulfides was very significant, reaching concentrations of Fe3 + 30 g/L and sulfate 60 g/L. © (2009) Trans Tech Publications.

The Tissue Banking Project in Chile started as an idea in 1996. Before 1996 in Chile there were only a few small bone banks working with their own standards of quality. The first tissue bank (LPTR) was established in 1998, with the technical and financial support of the IAEA. Since 2001, the laboratory began to produce tissues for clinical use, starting with the processing of 6 amniotic membranes, 2 femoral heads and 19 batches of pig skin. In 2002, the laboratory began the processing of human skin. Five students from Chile have graduated from training courses carried out in Singapore and in Buenos Aires under the IAEA training program since 1998. The amount of tissues produced and sterilized using ionizing radiation by the LPTR in the last years was 320,000 cm(2) of human skin, 553,600 cm(2) of pig skin, 5,400 cm(2) of amniotic membrane, 49 femoral heads, 3 large bones and 300 g of bovine bone. The patients treated with sterilized tissues produced by the LPTR were 200 deep burns treated with human skin and pig skin, 40 bone transplants from femoral heads, 77 ophthalmologic patients treated with amniotic membrane and 150 bovine bone transplants for dental treatments.