Effect of the charge state on bare monoicosahedral [Au13]z+ and diphosphine-protected Au13 clusters [Au13(dmpe)5Cl2]z+: structural, electronic and vibrational DFT studies.

In this paper a GGA-PBE study of [Au13]z+ bare clusters (z = +3, +5) and diphosphine protected [Au13(dmpe)5Cl2]z+ clusters (z = 1, 3) is presented. To explore the application of the [Au13((P(CH3)2CH2)2)5Cl2]3+ cluster as a cisplatin carrier, we have evaluated the adsorption energy of one cisplatin dimer interacting with the complex (0.53 eV). By considering a 1+ charge state, we have determined one cluster featuring a slight reduced HOMO-LUMO gap, with an inner Au13 core heavily distorted (strong charge effects). It is found that the filling/distribution of the superatomic energy levels is affected by the addition of two electrons to the [Au13(dmpe)5Cl2]3+ cluster with a reduction of its symmetry (C1 point group). In addition, the calculated IR and Raman spectra of charged [Au13(dmpe)5Cl2]z+ clusters allow distinguishing them.

Estereolitografía: conceptos básicos / Stereolithography: basic concepts

La Estereolitografía es un sistema de prototipado rápido por el cual se obtienen modelos sólidos en tres dimensiones, a través del procesamiento de datos obtenidos de la tomografía computarizada o la imagen por resonancia magnética. Esta técnica posee una variedad de aplicaciones en el campo de la medicina y la odontología, específicamente en el diagnóstico y planificación de tratamiento quirúrgico de las deformidades faciales, reconstrucciones óseas, dentales y de la Articulación Temporo-mandibular, etc. Estos modelos sirven también como registros o documentos físicos de la historia clínica de los pacientes y para educar e informar al paciente sobre el desarrollo del tratamiento. Por otro lado, el equipamiento es costoso, puede haber errores en el tamaño real o presencia de pseudoforámenes en algunas estructuras óseas delgadas. Otra desventaja, es que no se pueden reconstruir tejidos blandos, por lo tanto, su uso en reconstrucciones faciales es muy limitado.

The Stereolytography is a Fast Prototyping System andfrom which are obtained solid and three -dimension models, trough data processing from Computed Tomography and Resonance Magnetic Image. This technique has a variety of applications in medicine, dentistry fields, specifically in diagnostic and surgery treatment plan of facial deformities, bone, dental, and Temporo Mandibular Joint reconstructions, etc. These models are made, too, as physic record or document of a patients clinic history and for teaching and reporting to the patient about the treatment development. By the other hand, equipment is expensive, real size mistakes or pseudoforamina of some thin bone structures can appear. Another disadvantage, soft tissue can't be reconstructed, by the way, its use in facial reconstructions is very limited.

Astaxanthin production by Phaffia rhodozyma and Haematococcus pluvialis: a comparative study.

Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) and Haematococcus pluvialis are known as the major prominent microorganisms able to synthesize astaxanthin natural pigment. Important research efforts have been made to determine optimal conditions for astaxanthin synthesis. When the focus is on astaxanthin production, the maximal reported value of 9.2 mg/g cell is obtained within H. pluvialis grown on BAR medium, under continuous illumination (345 micromol photon m(-2) s(-1)) and without aeration. Whereas fermentation by mutated R1 yeast grown on coconut milk produced 1,850 microg/g yeast. However, when looking at astaxanthin productivity, the picture is slightly different. The figures obtained with P. rhodozyma are rather similar to those of H. pluvialis. Maximal reported values are 170 microg/g yeast per day with a wild yeast strain and 370 microg/g yeast per day with mutated R1 yeast. In the case of H. pluvialis, maximal values ranged from 290 to 428 microg/g cell per day depending on the media (BG-11 or BAR), light intensity (177 micromol photon m(-2) s(-1)), aeration, etc. The main aim of this work was to examine how astaxanthin synthesis, by P. rhodozyma and H. pluvialis, could be compared. The study is based on previous works by the authors where pigment productions have been reported.

Astaxanthin hyperproduction by Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) with raw coconut milk as sole source of energy.

Natural carbon sources, such as those present in cane sugar molasses and grape juice, promote the synthesis of astaxanthin in different Phaffia rhodozyma yeasts. One of these, coconut milk, has a very rich nutrient composition. The aim of this work was to investigate the utility of coconut milk as sole source of energy for astaxanthin pigment production by P. rhodozyma strains. Currently, coconut pulp is widely used in industrial processes in Mexico for the production of shampoos, candies, food, etc. However, coconut milk is a waste product. We show that coconut milk enhances astaxanthin production. The fermentation yielded 850 microg/g yeast with the NRRL-10921 wild-type strain and 1850 microg/g yeast with the mutated R1 strain. Production was better than reported results employing other natural carbon sources.

High-frequency FSH and LH pulses in obese menopausal women.

We studied the pulsatile luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretory patterns, at early or intermediate years of menopause in seven normal women with different degrees of obesity, taking blood samples every minute for 40 min to 2 h. The hormones were assayed with an immunoradiometric assay (IRMA) system, analyzing with the cluster pulse algorithm. All women showed hormone pulses every 8-10 min. In five of them were found periods of discrete pulses with oscillations of high amplitude alternating with periods of pulses of low amplitude. In two cases, the high-frequency oscillatory pattern with low amplitude was found around low mean levels of 22.8 and 25.7 IU/L. The LH oscillatory pattern also had a high frequency, but at a lower level, giving a high FSH/LH ratio. The coincidence index of FSH with LH peaks was 76.6%. We concluded that at menopause, the frequency of FSH and LH secretion increases with a high FSH/LH ratio. Obese menopausal women may have the same high-frequency oscillatory patterns, but at low levels.