Biogas dry reforming using Ni–Al-LDH catalysts reconstructed with Mg and Zn

The reconstruction of NiAl-LDH by incorporating Mg or Zn using a memory effect was investigated aiming to improve the basic properties of the catalysts and evaluated in the dry reforming of Biogas. Samples were characterized by XRD, CO₂?TPD, N₂-physisorption, TPR, and TPO. Biogas dry reforming experiments were carried out using a feed of CH₄/CO₂/N₂ = 1.5/1/7.5 in the temperature range of 500–750 °C with in situ reduced samples. The washing step strongly influences the LDH reconstruction. The unwashed samples showed the reconstruction of the LDH structure, presented a low specific area, and high basicity, responsible for decreasing carbon formation during reactions. The washed samples did not exhibit the LDH reconstruction property but showed a high specific area and low basicity. The metal used in the reconstruction influences the crystallinity, basicity, and reducibility of the materials. Samples with Zn showed higher crystallinity and reducibility, whereas the samples with Mg showed higher basicity. Among all the catalysts, reconstruction with Zn and subsequent washing leads to the best results with CH₄ and CO₂ conversion of 73% and 90%, respectively, and an H₂/CO ratio of approximately 2. This can be attributed to the Ni–Zn alloy formation and to the reducing properties suitable for the range between 600 and 700 °C. This catalyst showed the highest resistance to sintering in the stability test at 700 °C.     

Effect of simulated acidic and salty fermentation conditions on kinetic growth parameters and probiotic potential of Lactobacillus acidipiscis and Lactobacillus pentosus

The technological stress during food processing may alter the beneficial interactions of food-associated Lactobacillus on the host. The effect of initial combined acidic (pH 5.0) and osmotic stress (NaCl 5 %, w/v with or without CaCl₂ 0.02 %, w/v) typically present in vegetable fermentations and cheesemaking were investigated. The growth kinetics prediction, hydrophobicity, auto-aggregation, in vitro survival and adhesion were determined in Lactobacillus acidipiscis and Lactobacillus pentosus isolated from a Mexican salty cheese. The growth was modelled with the modified Gompertz equation (R > 0.99; RMSE < 0.01). The lag phase increased (>10 h), and auto-aggregation was reduced. Hydrophobicity and S-layer total proteins varied. Gut survival reduced >4 log 10 units compared to the initial intake. Nevertheless, adhesion remained the same. Hence, combined stress affected the technological and physiological properties of both strains negatively. Further research is needed to identify the effect of the combined stress on the potential bioactivity of the strains.     

Changes on publishing behavior in response to research policy guidelines. The case of the Spanish Research Council in the field of agronomy

The aim of this study is to identify changes in publishing behavior of Spanish scientists belonging to the Area of Agronomy of the Spanish Research Council (CSIC), in response to scientific policy actions carried out in Spain. For this purpose, we analyze Spanish scientific output published in Spanish journals (covered by the ICYT database), as well as in international journals (covered by theScience Citation Index), during the period 1980–1995. Congress and conference publications, books and monographs, are also considered. The following changes in publication habits have been noticed: migration of works towards SCI journals and increased use of books and monographs as channel of publication of research works. A decreasing participation of Spanish researchers in scientific meetings has also been noticed, especially since 1989.     

Prenatal diagnosis of biliary atresia associated with choledochal cyst

We report a case of biliary atresia promptly detected by its association with a choledochal cyst, prenatally diagnosed at 20 weeks' gestation. The baby was operated at 14 days of life. A choledochal cyst was found and fibrosis of the extrahepatic bile ducts was also noted. So, excision of the choledochal cyst and a Roux-en-Y porto-jejunostomy was done. Nine months later, despite an appropriate biliary drainage, echographic and histological changes compatible with liver cirrhosis have been detected. Including this one, six cases have been reported.     

Complementary and overlapping expression of glial cell line-derived neurotrophic factor (GDNF), c-ret proto-oncogene, and GDNF receptor-alpha indicates multiple mechanisms of trophic actions in the adult rat CNS

Glial cell line-derived neurotrophic factor (GDNF), the most potent trophic factor yet described for both dopaminergic neurons of the substantia nigra and spinal motorneurons, has recently been shown to signal through a multireceptor complex composed of a novel glycosylphosphatidylinositol-anchored GDNF receptor-alpha (GDNFR-alpha) and the receptor tyrosine kinase product of the c-ret proto-oncogene (RET). Despite its importance, the individual expression patterns and the relationships between domains of expression of the different components of this trophic system are not understood. We show here by in situ hybridization that GDNF mRNA is expressed in the normal adult rat brain in several targets of substantia nigra neurons, including striatum, nucleus accumbens, thalamic nuclei, olfactory tubercle, hippocampus, cerebellum, and cingulate cortex as well as in the internal granular cell layer of the olfactory bulb. Within the basal ganglia we observe a pronounced segregation of regions expressing GDNF from those expressing GDNF receptors, suggesting that within these structures GDNF is functioning in its anticipated role as a target-derived trophic factor. In addition, the expression of GDNF and both GDNF receptors within the cerebellum, hippocampus, and olfactory bulb may indicate a paracrine mode of action. Importantly, we also see expression of RET mRNA in cellular populations within the cerebellum and the glomerular layer of the olfactory bulb, as well as in the subthalamic nucleus, which lack GDNFR-alpha expression, indicating that RET functions either independently of GDNFR-alpha or with GDNFR-alpha presented in trans. Conversely, GDNFR-alpha is widely expressed in many regions in which RET expression is absent, suggesting that GDNFR-alpha may associate with additional signaling receptors. Finally, RET and GDNFR-alpha show distinct patterns of regulated expression in the brain after kainic acid stimulation and in the sciatic nerve after nerve transection. Taken together these findings indicate that GDNF, RET, and GDNFR-alpha utilize multiple mechanisms to comprise physiologically relevant trophic circuits for different neuronal populations.     

Trifluoperazine increases fatty acid turnover in phospholipids in cultured human fibroblasts

A 24-hr pretreatment of cultured human fibroblasts with trifluoperazine induced a marked increase in incorporation of saturated (stearic, palmitic) and unsaturated (oleic, arachidonic) fatty acids into phospholipids (1.5- to 2-fold for 5.10⁻⁵ M trifluoperazine). Concomitantly, incorporation into cholesteryl esters was strongly inhibited (20% of control for 5.10⁻⁵ M trifluoperazine). The drug did not change the phospholipid composition of treated cells. The effect of trifluoperazine on oleic acid incorporation into phospholipids was time-dependent and reached a maximum after a six-hr preincubation with the drug. Trifluoperazine also induced an increase in the rate of chase of oleic acid from the different phospholipid classes. In vitro preincubation of cell-free extracts with trifluoperazine resulted in activation of phospholipid acyltransferases, whereas cholesterol acyltransferase activity was decreased. The rapid effect of trifluoperazine together with its effect on a cell-free system suggests a direct action of this amphiphilic drug on the acyltransferase activities, probably by modification of the structural organization of cellular membranes.     

Lipids and lipogenic enzymes in adipose tissue of castrated male goats

Male goats (“Criolla Argentina” breed), castrated at 45 days of age, showed altered lipid metabolism 180 days after castration as compared to control goats. Subcutaneous, perirenal and omental adipose tissues of castrated goats showed increases in fatty acid synthetase, glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase activities. Castration increased the amount of total lipids and triglycerides, but did not modify the amount of cholesterol, phospholipid and protein in the three types of adipose tissue. The incorporation of [1-¹⁴C]acetate into fatty acids of subcutaneous and perirenal adipose tissue was increased in castrated goats in relation to noncastrated goats. Our results suggest that removal of gonadal steroids increases significantly the rate of lipogenesis in adipose tissue of male goats.     

Unilateral neonatal cystic disease of the kidney as first manifestation of tuberous sclerosis]

Traumatic optic neuropathy (TON) causes blindness of varied severity and occurs infrequently as a complication of closed head injury. A case is presented of TON that occurred in a patient who suffered complete T4 paraplegia from a motorcycle accident but in whom no severe head injury took place. In this case, high-dose intravenous methylprednisolone was begun for the spinal cord injury and repeated 24 hours later for the TON. Vision improved from near total blindness to 20/400 in the left eye (OS) and 20/130 in the right eye (OD). Two weeks later, however, the patient's vision suddenly worsened. Magnetic resonance imaging (MRI) using fat suppression confirmed a lesion along the optic nerve consistent with TON. A third course of methylprednisolone again led to improved vision. The steroids were then tapered orally over 2 weeks and the patient had no further relapses. Moderate to severely impaired vision of 20/ 400 OS and 20/130 OD continues to interfere with the patient's function and spinal cord rehabilitation program. It was concluded that a steroid taper was important in maintaining initial visual gains in this case. Awareness of TON and careful attention to the patient's clinical course can minimize deficit and maximize functional outcomes.