Fragmentation channels of relativistic 7^7Be nuclei in peripheral interactions

Nuclei of $^7$Li were accelerated at the JINR Nuclotron. After the charge-exchange reaction involving these nuclei at an external target a second $^7$Be beam of energy 1.23A GeV was formed. This beam was used to expose photo-emulsion chambers. The mean free path for inelastic $^7$Be interactions in emulsion $\lambda$=14.0$\pm$0.8 cm coincides within the errors with those for $^6$Li and $^7$Li nuclei. More than 10% of the $^7$Be events are associated with the peripheral interactions in which the total charge of the relativistic fragments is equal to the charge of the $^7$Be and in which charged mesons are not produced. An unusual ratio of the isotopes is revealed in the composition of the doubly charged $^7$Be fragments: the number of $^3$He fragments is twice as large as that of $^4$He fragments. In 50% of peripheral interactions, a $^7$Be nucleus decays to two doubly charged fragments. The present paper gives the channels of the $^7$Be fragmentation to charged fragments. In 50% of events, the $^7$Be fragmentation proceeds only to charged fragments involving no emission of neutrons. Of them, the $^3$He+$^4$He channel dominates, the $^4$He+d+p and $^6$Li+pchannels constitute 10% each. Two events involving no emission of neutrons are registered in the 3-body $^3$He+t+p and $^3$He+d+d channels. The mean free path for the coherent dissociation of relativistic $^7$Be nuclei to $^3$He+$^4$He is 7$\pm$1 m. The particular features of the relativistic $^7$Be fragmentation in such peripheral interactions are explained by the $^3$He+$^4$He 2-cluster structure of the $^7$Be nucleus.Comment: 10 pages, 3 figures, 3 tables, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 200

Chromatin establishes an immature version of neuronal protocadherin selection during the naive-to-primed conversion of pluripotent stem cells.

In the mammalian genome, the clustered protocadherin (cPCDH) locus provides a paradigm for stochastic gene expression with the potential to generate a unique cPCDH combination in every neuron. Here we report a chromatin-based mechanism that emerges during the transition from the naive to the primed states of cell pluripotency and reduces, by orders of magnitude, the combinatorial potential in the human cPCDH locus. This mechanism selectively increases the frequency of stochastic selection of a small subset of cPCDH genes after neuronal differentiation in monolayers, 10-month-old cortical organoids and engrafted cells in the spinal cords of rats. Signs of these frequent selections can be observed in the brain throughout fetal development and disappear after birth, except in conditions of delayed maturation such as Down's syndrome. We therefore propose that a pattern of limited cPCDH-gene expression diversity is maintained while human neurons still retain fetal-like levels of maturation

The Burkholderia Cenocepacia OmpA-Like Protein BCAL2958: Identification, Characterization, and Detection of Anti-BCAL2958 Antibodies in Serum from B. Cepacia Complex-Infected Cystic Fibrosis Patients

Respiratory infections by bacteria of the Burkholderia cepacia complex (Bcc) remain an important cause of morbidity and mortality among cystic fibrosis patients, highlighting the need for novel therapeutic strategies. In the present work we have studied the B. cenocepacia protein BCAL2958, a member of the OmpA-like family of proteins, demonstrated as highly immunogenic in other pathogens and capable of eliciting strong host immune responses. The encoding gene was cloned and the protein, produced as a 6× His-tagged derivative, was used to produce polyclonal antibodies. Bioinformatics analyses led to the identification of sequences encoding proteins with a similarity higher than 96 % to BCAL2958 in all the publicly available Bcc genomes. Furthermore, using the antibody it was experimentally demonstrated that this protein is produced by all the 12 analyzed strains from 7 Bcc species. In addition, results are also presented showing the presence of anti-BCAL2958 antibodies in sera from cystic fibrosis patients with a clinical record of respiratory infection by Bcc, and the ability of the purified protein to in vitro stimulate neutrophils. The widespread production of the protein by Bcc members, together with its ability to stimulate the immune system and the detection of circulating antibodies in patients with a documented record of Bcc infection strongly suggest that the protein is a potential candidate for usage in preventive therapies of infections by Bcc

Immunological characterization of chromogranins A and B and secretogranin II in the bovine pancreatic islet

Antisera against chromogranin A and B and secretogranin II were used for analysing the bovine pancreas by immunoblotting and immunohistochemistry. All three antigens were found in extracts of fetal pancreas by one dimensional immunoblotting. A comparison with the soluble proteins of chromaffin granules revealed that in adrenal medulla and in pancreas antigens which migrated identically in electrophoresis were present. In immunohistochemistry, chromogranin A was found in all pancreatic endocrine cell types with the exception of most pancreatic polypeptide-(PP-) producing cells. For chromogranin B, only a faint immunostaining was obtained. For secretorgranin II, A-and B-cells were faintly positive, whereas the majority of PP-cells exhibited a strong immunostaining for this antigen. These results establish that chromogranins A and B and secretogranin II are present in the endocrine pancreas, but that they exhibit a distinct cellular localization

Magnetic nanoparticles as MRI contrast agents for the diagnosis of Alzheimer’s disease

Background Nanoparticle‐based magnetic contrast agents have opened the potential for Magnetic Resonance Imaging (MRI) to be used for early non‐invasive diagnosis of Alzheimer’s disease (AD). Current methods for clinical diagnosis in the early stages of the disease, such as Positron Emission Tomography imaging of amyloid build‐up, are limited by their availability and cost. The aim of this research is to develop a novel non‐toxic amyloid targeted nanoparticle which can successfully permeate the blood brain barrier and bind amyloid plaques resulting in enhanced contrast in the MR image and improved diagnostic sensitivity. Methods Targeted iron nanoparticles were assessed using a U‐251 cell line to determine their in vitro toxicity. Transmission electron microscopy was used to determine the movement of the nanoparticles within the cell and in vitro binding to amyloid fibrils. APPSwe/PSEN1 mice were treated with increasing doses of targeted and non‐targeted nanoparticles to evaluate acute in vivo toxicity, in addition to nanoparticle biodistribution and MRI contrast enhancement. Results The novel targeted nanoparticles have demonstrated no significant in vitro toxicity and electron microscopy results show their movement through the endocytic cycle within the cell, demonstrating an effective degradation and clearance pathway (Figure). No acute toxicity was observed in the animal model. In addition, immunohistochemistry demonstrated nanoparticles to co‐localise with plaques on ex vivo brain sections. Conclusion The present work shows promising preliminary results in the development of a targeted non‐invasive method of early AD diagnosis using contrast enhanced MRI

Foliar application of exogenous gibberellin or cytokinin mitigates salinity stress on faba bean (Vicia faba L.)

Soil salinity significantly impairs plant development by reducing the availability of water and essential nutrients. This study explores the potential of gibberellin (GA) and cytokinin (CK) in mitigating detrimental effects of salinity stress on faba bean. Seeds were sown in saline soil, and plants were subjected to foliar applications of GA and CK at concentrations of 25 and 50 mg L-1. Results revealed that both hormones significantly enhanced key growth attributes, including plant height, total leaf area, and dry biomass. Moreover, chlorophyll (chl. a, b, total chl.) content increased alongside elevated levels of proline, total phenols, crude protein, membrane stability, and macronutrient (NPK) concentrations. Gibberellin and CK treatments also promoted branching and flowering, while reducing the percentage of flower shedding. In terms of yield-related traits, significant improvements were observed in seed yield per hectare, weight of 100-seed, seed number/pod, seed weight per pod, and overall reduction in flower drop. The most significant enhancements in the evaluated traits were recorded with the application of GA and CK at a concentration of 50 mg L-1 during both seasons. These findings highlight the effectiveness of GA and CK in strengthening salt tolerance mechanisms and boosting the productivity of faba bean under saline conditions

PRODUCTION OF L-TRYPTOPHAN BY MUTANTS OF CORYNEBACTERIUM GLUTAMICUM

L-Tryptophan, is one of the amino acids, also is one of the 9 essential amino acids of human which cannot be synthesized internally by him, microbial production is the main method for obtaining tryptophan for commercial uses. Typical microorganisms used for tryptophan production are E. coli and C. glutamicum. In this study, random mutations is performed on two strains of C. glutamicum to increase tryptophan production, the produced tryptophan measured by bioassay using tryptophan auxotroph E. coli (JW1254-2) strain, the mutations are performed using UV radiation. To detect and compare the difference between the parent strains and the muted strains genetically two molecular markers were used start codon targeted polymorphism (SCoT) and Inter-simple sequence repeats (ISSR). Tryptophan remarkably increased after C. glutamicum mutation to reach 278.4 µg/ml (1257.4% increment) from one mutated strain. Molecular genetics methods showed an ability to distinguish between the two original strains and their mutants and it showed the importance of the mutation by UV radiation for increasing the productivity of the bacteria to tryptophan

Flexible Bench-Scale Recirculating Flow CPC Photoreactor for Solar Photocatalytic Degradation of Methylene Blue Using Removable TiO 2

TiO2 immobilized on polyethylene (PET) nonwoven sheet was used in the solar photocatalytic degradation of methylene blue (MB). TiO2 Evonik Aeroxide P25 was used in this study. The amount of loaded TiO2 on PET was approximately 24%. Immobilization of TiO2 on PET was conducted by dip coating process followed by exposing to mild heat and pressure. TiO2/PET sheets were wrapped on removable Teflon rods inside home-made bench-scale recirculating flow Compound Parabolic Concentrator (CPC) photoreactor prototype (platform 0.7 × 0.2 × 0.4 m3). CPC photoreactor is made up of seven low iron borosilicate glass tubes connected in series. CPC reflectors are made of stainless steel 304. The prototype was mounted on a platform tilted at 30°N local latitude in Cairo. A centrifugal pump was used to circulate water containing methylene blue (MB) dye inside the glass tubes. Efficient photocatalytic degradation of MB using TiO2/PET was achieved upon the exposure to direct sunlight. Chemical oxygen demand (COD) analyses reveal the complete mineralization of MB. Durability of TiO2/PET composite was also tested under sunlight irradiation. Results indicate only 6% reduction in the amount of TiO2 after seven cycles. No significant change was observed for the physicochemical characteristics of TiO2/PET after the successive irradiation processes

Relationship between craving and personality in treatment-seeking women with substance-related disorders

BACKGROUND: Individual differences may impact susceptibility to addiction. The impact of personality features on drug craving, however, has not been studied, particularly in women. METHODS: Ninety-five treatment-seeking women with substance dependence, abstinent for at least 5 and no more than 21 days, were investigated regarding the correlation between personality factors and craving. Personality was assessed using the Temperament and Character Inventory (TCI), the NEO Personality Inventory Revised (NEO-PI-R), and the Barratt Impulsiveness Scale version 11 (BIS-11). Cravings were assessed through the Pennsylvania Craving Scale (PCS), and the Craving Questionnaire (CQ). Anxiety and depressive symptomatology were also recorded. RESULTS: Craving scores were positively correlated with depression and negatively correlated with number of days abstinent from substance use. Also, craving scores were positively associated with the novelty-seeking factor from the TCI and the total score on the BIS-11, and negatively associated with the conscientiousness and agreeableness facets of the NEO-PI-R. CONCLUSION: Findings suggest that personality features, particularly impulsiveness, can be important predictors of craving in women, which has important implications for treatment planning