Dosimetry and radio-stimulation in mesquite (Neltuma laevigata W.) seeds

Objective: The research focused on a germination response in Mezquite (Neltuma laevigata) using gamma radiation (Cobalt 60) at different doses aiming to obtain a greater germination response than a non-irradiated seed. Design/methodology/approach: The seeds had different collection times and identities, a lot from Durango (10 years) and other from Hidalgo (2 months). Both lots were exposed to sixteen different doses of gamma radiation, having a control (non irradiated). Seeds were subsequently subjected to in vitro conditions using Murashige and Skoog medium. They were monitored daily for a period of two weeks to record the exact day of gemination. Results: The best treatment observed for germination stimulation radio in the provenance of the Durango batch was with 30-gray radiation increasing by 12% compared to the control, while for the batch from Hidalgo it was the one that received a radiation of 6 gray increasing 56% compared to the control. Limitations on study/implications: for this study only two different populations were evaluated and because there were differences between them, the ideal would be to work with material of the other origins. Findings/conclusions: Gamma radiation at low doses causes an increase in seed germination rate.Objective: To carry out research focused on the germination response of mesquite (Neltuma laevigata) to different doses of gamma radiation (Cobalt 60), in order to obtain a higher germination response than with a non-irradiated seed. Design/Methodology/Approach: Seeds had different collection times and identities. One set was collected in Durango (10 years) and another in Hidalgo (2 months). Both sets were exposed to sixteen different doses of gamma radiation and a control (non-irradiated); they were subsequently subjected to in vitro conditions using a Murashige and Skoog basal medium. They were monitored daily for two weeks in order to develop an accurate record of their germination. Results: The best treatment for the radio-stimulation of germination in the Durango set was observed at 30 gray (12% higher than the control). Meanwhile, the Hidalgo set received 6 gray radiation (56% higher than the control). Study Limitations/Implications: Only two different populations were evaluated for this study. Given the differences found between them, working with material from other origins would be ideal. Findings/Conclusions: Low doses of gamma radiation cause an increase in the germination rate of seeds

P-P Total Cross Sections at VHE from Accelerator Data

Comparison of P-P total cross-sections estimations at very high energies - from accelerators and cosmic rays - shows a disagreement amounting to more than 10 %, a discrepancy which is beyond statistical errors. Here we use a phenomenological model based on the Multiple-Diffraction approach to successfully describe data at accelerator energies. The predictions of the model are compared with data On the basis of regression analysis we determine confident error bands, analyzing the sensitivity of our predictions to the employed data for extrapolation. : using data at 546 and 1.8 TeV, our extrapolations for p-p total cross-sections are only compatible with the Akeno cosmic ray data, predicting a slower rise with energy than other cosmic ray results and other extrapolation methods. We discuss our results within the context of constraints in the light of future accelerator and cosmic ray experimental results.Comment: 26 pages aqnd 11 figure

Deciphering biomarkers for leptomeningeal metastasis in malignant hemopathies (Lymphoma/Leukemia) patients by comprehensive multipronged proteomics characterization of cerebrospinal fluid

In the present work, leptomeningeal disease, a very destructive form of systemic cancer, was characterized from several proteomics points of view. This pathology involves the invasion of the leptomeninges by malignant tumor cells. The tumor spreads to the central nervous system through the cerebrospinal fluid (CSF) and has a very grim prognosis; the average life expectancy of patients who suffer it does not exceed 3 months. The early diagnosis of leptomeningeal disease is a challenge because, in most of the cases, it is an asymptomatic pathology. When the symptoms are clear, the disease is already in the very advanced stages and life expectancy is low. Consequently, there is a pressing need to determine useful CSF proteins to help in the diagnosis and/or prognosis of this disease. For this purpose, a systematic and exhaustive proteomics characterization of CSF by multipronged proteomics approaches was performed to determine different protein profiles as potential biomarkers. Proteins such as PTPRC, SERPINC1, sCD44, sCD14, ANPEP, SPP1, FCGR1A, C9, sCD19, and sCD34, among others, and their functional analysis, reveals that most of them are linked to the pathology and are not detected on normal CSF. Finally, a panel of biomarkers was verified by a prediction model for leptomeningeal disease, showing new insights into the research for potential biomarkers that are easy to translate into the clinic for the diagnosis of this devastating disease.We gratefully acknowledge financial support from the Spanish Health Institute, Carlos III (ISCIII), for the grants: FIS PI14/01538, FIS PI17/01930 and CB16/12/00400. We also acknowledge Fondos FEDER (EU) and Junta Castilla-León (COVID-19 grant COV20EDU/00187). The Proteomics Unit belongs to ProteoRed, PRB3-ISCIII, supported by grant PT17/0019/0023 of the PE I + D + I2017-2020, funded by ISCIII and FEDER—Norma Galicia is supported by the CONACYT Program. P. Juanes-Velasco is supported by JCYL PhD Program “Nos Impulsa-JCYL” and scholarship JCYLEDU/601/2020

Failures of nerve regeneration caused by aging or chronic denervation are rescued by restoring Schwann cell c-Jun.

After nerve injury, myelin and Remak Schwann cells reprogram to repair cells specialized for regeneration. Normally providing strong regenerative support, these cells fail in aging animals, and during chronic denervation that results from slow axon growth. This impairs axonal regeneration and causes significant clinical problems. In mice, we find that repair cells express reduced c-Jun protein as regenerative support provided by these cells declines during aging and chronic denervation. In both cases, genetically restoring Schwann cell c-Jun levels restores regeneration to control levels. We identify potential gene candidates mediating this effect and implicate Shh in the control of Schwann cell c-Jun levels. This establishes that a common mechanism, reduced c-Jun in Schwann cells, regulates success and failure of nerve repair both during aging and chronic denervation. This provides a molecular framework for addressing important clinical problems, suggesting molecular pathways that can be targeted to promote repair in the PNS

Electron quantum metamaterials in van der Waals heterostructures

In recent decades, scientists have developed the means to engineer synthetic periodic arrays with feature sizes below the wavelength of light. When such features are appropriately structured, electromagnetic radiation can be manipulated in unusual ways, resulting in optical metamaterials whose function is directly controlled through nanoscale structure. Nature, too, has adopted such techniques -- for example in the unique coloring of butterfly wings -- to manipulate photons as they propagate through nanoscale periodic assemblies. In this Perspective, we highlight the intriguing potential of designer sub-electron wavelength (as well as wavelength-scale) structuring of electronic matter, which affords a new range of synthetic quantum metamaterials with unconventional responses. Driven by experimental developments in stacking atomically layered heterostructures -- e.g., mechanical pick-up/transfer assembly -- atomic scale registrations and structures can be readily tuned over distances smaller than characteristic electronic length-scales (such as electron wavelength, screening length, and electron mean free path). Yet electronic metamaterials promise far richer categories of behavior than those found in conventional optical metamaterial technologies. This is because unlike photons that scarcely interact with each other, electrons in subwavelength structured metamaterials are charged, and strongly interact. As a result, an enormous variety of emergent phenomena can be expected, and radically new classes of interacting quantum metamaterials designed

The highly prevalent BRCA2 mutation c.2808_2811del (3036delACAA) is located in a mutational hotspot and has multiple origins

BRCA2-c.2808_2811del (3036delACAA) is one of the most reported germ line mutations in non-Ashkenazi breast cancer patients. We investigated its genetic origin in 51 Spanish carrier families that were genotyped with 11 13q polymorphic markers. Three independent associated haplotypes were clearly distinguished accounting for 23 [west Castilla y León (WCL)], 20 [east Castilla y León (ECL)] and 6 (South of Spain) families. Mutation age was estimated with the Disequilibrium Mapping using Likelihood Estimation software in a range of 45–68 and 45–71 generations for WCL and ECL haplotypes, respectively. The most prevalent variants, c.2808_2811del and c.2803G > A, were located in a double-hairpin loop structure (c.2794–c.2825) predicted by Quikfold that was proposed as a mutational hotspot. To check this hypothesis, random mutagenesis was performed over a 923 bp fragment of BRCA2, and 86 DNA variants were characterized. Interestingly, three mutations reported in the mutation databases (c.2680G > A, c.2944del and c.2957dup) were replicated and 20 affected the same position with different nucleotide changes. Moreover, five variants were placed in the same hairpin loop of c.2808_2811del, and one affected the same position (c.2808A > G). In conclusion, our results support that at least three different mutational events occurred to generate c.2808_2811del. Other highly prevalent DNA variants, such as BRCA1-c.68_69delAG, BRCA2- c.5946delT and c.8537delAG, are concentrated in hairpin loops, suggesting that these structures may represent mutational hotspots