263 research outputs found

    Recycling aggregate from concrete, properties and possibility for using in ready Mix Concrete

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    Many requests for different types of concrete, in general are depends of the aggregates. One of the aim of this paper is to analyses the possibilities of using the recycling aggregate, from part of existing concrete such a raw materials and during the technological process for production of aggregate. Recycling of concrete is a relatively simple process. It involves breaking, removing, and crushing existing concrete into a material with a specified size and quality. In this paper the main target is to compare the properties of fresh concrete and the hardening concrete for the mix design with crashed aggregate and recycling aggregate from parts of concrete after the demolition process.Nowadays large amount of demolished concrete are available on construction sites which are now posing a serious problem for transport in urban areas. Day by day this amount is larger and the reasons are that:- Many old buildings, concrete sidewalks, bridges and other structures have exceeded their age limit use due to structural deterioration.- Other possible structures for use are in ruin, because they are not serving the needs of today's society.- Structures have become waste resulting from natural disasters like cyclones, earthquakes,floods etc.As a result of greater demand for concrete, taking into account the fact that aggregate isthe component with the largest participation in concrete. Decreasing the source of natural aggregate we should explore the use of recycled aggregate. Recycled aggregate has goodquality especially in resistance to pressure when the content of brick is not more than 0.5%, it presents the potential for use in a wide range of applications, for the case when it meets the test and performance requirements. However the quality of the concrete which is made with recycled aggregate is lower compared to concrete which is made with natural aggregate.Nowadays, the application of recycled aggregate in construction areas is extensive. It's application is different from country to country, in the sense that each state sets the criteriafor use depending on it's quality.Based on the experience of use, recycled aggregate can be used for: production of concrete, in concrete roads, for production of concrete domes, as padding of the embankment,for construction of pipes, production of concrete blocks etc. Almost in all cases where natural aggregate is used.Based on laboratory analysis Recycled aggregate compared with natural aggregate: absorbsmore water, it has less density in many cases, it has lower specific weight, lower resistance to abrasion, it's more easily to destroy it, it contains more dust particles etc. Due to these results to gain the desired work ability of concrete obtained from the recycled aggregate is necessaryto add a certain amount of water to saturate recycled aggregate before or during mixing with other ingredients of concrete, if not previously used any additional reducing the rate of water absorption. On the other hand it is very important to use the concrete with recycling aggregate for the concrete which offer very good properties in thermo insulation, such a very important request in efficiency of energy

    Evaluation of the residual nitrite concentrations of locally produced and imported meat products in Kosovo

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    The use of food additive nitrite as curing agents is common in meat products, but their concentration in these products has raised the interest of researchers, because of the possible toxicity to humans.  The aim of this study is to assess the nitrite concentration in meat products, which are highly used by all population groups in Kosovo. A total of 44 different meat products samples available on sale to the population, were assessed for residual nitrite using the spectrophotometric method that uses absorption in visible part of spectra. The amount of residual nitrites was detected in 19 (43%) of the samples, which included beef and chicken sausages, chicken & beef salami as well as beef prosciutto samples. The nitrite residue ranged between 0.1 and 11.5 mg/kg and was below the limits on the concentration of nitrites in meat products established by EU regulation 601/2014.  Although these findings show that, the nitrite residue in the analyzed meat products is within the permitted limits, the highest presence of residual nitrite in industrial and low-cost meat products indicates a need for further assessments of nitrite exposure among consumers

    Trends of Tuberculosis Treatment Outcomes of Notified Cases in Three Refugee Camps in Sudan: A Four-year Retrospective Analysis, 2014–2017

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    Background: Refugees are vulnerable to tuberculosis (TB) infection. Tracking of program performance is needed to improve TB care and prevention. The objective of this study was to assess the trends of TB treatment outcomes of notified cases in three refugee camps in Sudan from 2014 to 2017. Methods: This study was a historical cohort study. Sex, age, type of TB, TB patient category, and treatment outcome of all TB cases registered in three refugee camps (Al Kashafa, Shagarab, Wadsherify) from January 1, 2014 to December 31, 2017 were collected from the TB register. Multivariable logistic regression was performed to explore factors for unsuccessful TB treatment. Results: A total of 710 TB cases of which 53.4% were men, 22.1% children (<15 years), and 36.2% extrapulmonary TB (EPTB) were registered. Overall, the TB treatment success rate was 75.7% with a declining trend from 86.2% in 2015 to 63.5% in 2017. On average, 11.4% were lost to follow-up (LTFU), 6.6% died, 5.9% were not evaluated, and in 0.3% the treatment failed. Being 15–24 years old and having EPTB were significantly associated with unsuccessful treatment outcome. Conclusion: The treatment success rate in the refugee camp in 2017 (63.5%) was far lower than the national treatment success rate (78%) and the End TB global target (≥90%) that needs to be improved. LTFU, died, and not evaluated outcomes were high which indicated the necessity to improve the TB treatment program

    Broad clinical phenotypes associated with TAR-DNA binding protein (TARDBP) mutations in amyotrophic lateral sclerosis

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    The finding of TDP-43 as a major component of ubiquitinated protein inclusions in amyotrophic lateral sclerosis (ALS) has led to the identification of 30 mutations in the transactive response-DNA binding protein (TARDBP) gene, encoding TDP-43. All but one are in exon 6, which encodes the glycine-rich domain. The aim of this study was to determine the frequency of TARDBP mutations in a large cohort of motor neurone disease patients from Northern England (42 non-superoxide dismutase 1 (SOD1) familial ALS (FALS), nine ALS-frontotemporal dementia, 474 sporadic ALS (SALS), 45 progressive muscular atrophy cases). We identified four mutations, two of which were novel, in two familial (FALS) and two sporadic (SALS) cases, giving a frequency of TARDBP mutations in non-SOD1 FALS of 5% and SALS of 0.4%. Analysis of clinical data identified that patients had typical ALS, with limb or bulbar onset, and showed considerable variation in age of onset and rapidity of disease course. However, all cases had an absence of clinically overt cognitive dysfunction

    FUS and TARDBP but Not SOD1 Interact in Genetic Models of Amyotrophic Lateral Sclerosis

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    Mutations in the SOD1 and TARDBP genes have been commonly identified in Amyotrophic Lateral Sclerosis (ALS). Recently, mutations in the Fused in sarcoma gene (FUS) were identified in familial (FALS) ALS cases and sporadic (SALS) patients. Similarly to TDP-43 (coded by TARDBP gene), FUS is an RNA binding protein. Using the zebrafish (Danio rerio), we examined the consequences of expressing human wild-type (WT) FUS and three ALS–related mutations, as well as their interactions with TARDBP and SOD1. Knockdown of zebrafish Fus yielded a motor phenotype that could be rescued upon co-expression of wild-type human FUS. In contrast, the two most frequent ALS–related FUS mutations, R521H and R521C, unlike S57Δ, failed to rescue the knockdown phenotype, indicating loss of function. The R521H mutation caused a toxic gain of function when expressed alone, similar to the phenotype observed upon knockdown of zebrafish Fus. This phenotype was not aggravated by co-expression of both mutant human TARDBP (G348C) and FUS (R521H) or by knockdown of both zebrafish Tardbp and Fus, consistent with a common pathogenic mechanism. We also observed that WT FUS rescued the Tardbp knockdown phenotype, but not vice versa, suggesting that TARDBP acts upstream of FUS in this pathway. In addition we observed that WT SOD1 failed to rescue the phenotype observed upon overexpression of mutant TARDBP or FUS or upon knockdown of Tardbp or Fus; similarly, WT TARDBP or FUS also failed to rescue the phenotype induced by mutant SOD1 (G93A). Finally, overexpression of mutant SOD1 exacerbated the motor phenotype caused by overexpression of mutant FUS. Together our results indicate that TARDBP and FUS act in a pathogenic pathway that is independent of SOD1

    TDP-43-Mediated Neuron Loss In Vivo Requires RNA-Binding Activity

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    Alteration and/or mutations of the ribonucleoprotein TDP-43 have been firmly linked to human neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). The relative impacts of TDP-43 alteration, mutation, or inherent protein function on neural integrity, however, remain less clear—a situation confounded by conflicting reports based on transient and/or random-insertion transgenic expression. We therefore performed a stringent comparative investigation of impacts of these TDP-43 modifications on neural integrity in vivo. To achieve this, we systematically screened ALS/FTLD-associated and synthetic TDP-43 isoforms via same-site gene insertion and neural expression in Drosophila; followed by transposon-based motor neuron-specific transgenesis in a chick vertebrate system. Using this bi-systemic approach we uncovered a requirement of inherent TDP-43 RNA-binding function—but not ALS/FTLD-linked mutation, mislocalization, or truncation—for TDP-43-mediated neurotoxicity in vivo

    Mutant TDP-43 and FUS Cause Age-Dependent Paralysis and Neurodegeneration in C. elegans

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    Mutations in the DNA/RNA binding proteins TDP-43 and FUS are associated with Amyotrophic Lateral Sclerosis and Frontotemporal Lobar Degeneration. Intracellular accumulations of wild type TDP-43 and FUS are observed in a growing number of late-onset diseases suggesting that TDP-43 and FUS proteinopathies may contribute to multiple neurodegenerative diseases. To better understand the mechanisms of TDP-43 and FUS toxicity we have created transgenic Caenorhabditis elegans strains that express full-length, untagged human TDP-43 and FUS in the worm's GABAergic motor neurons. Transgenic worms expressing mutant TDP-43 and FUS display adult-onset, age-dependent loss of motility, progressive paralysis and neuronal degeneration that is distinct from wild type alleles. Additionally, mutant TDP-43 and FUS proteins are highly insoluble while wild type proteins remain soluble suggesting that protein misfolding may contribute to toxicity. Populations of mutant TDP-43 and FUS transgenics grown on solid media become paralyzed over 7 to 12 days. We have developed a liquid culture assay where the paralysis phenotype evolves over several hours. We introduce C. elegans transgenics for mutant TDP-43 and FUS motor neuron toxicity that may be used for rapid genetic and pharmacological suppressor screening

    Broadening the phenotype of TARDBP mutations: the TARDBP Ala382Thr mutation and Parkinson’s disease in Sardinia

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    Mutations in the TARDBP gene are a cause of autosomal dominant amyotrophic lateral sclerosis (ALS) and of frontotemporal lobar degeneration (FTLD), but they have not been found so far in patients with Parkinson’s disease (PD). A founder TARDBP mutation (p.Ala382Thr) was recently identified as the cause of ~30% of ALS cases in Sardinia, a Mediterranean genetic isolate. We studied 327 consecutive Sardinian patients with clinically diagnosed PD (88 familial, 239 sporadic) and 578 Sardinian controls. One family with FTLD and parkinsonism was also included. The p.Ala382Thr heterozygous mutation was detected in eight unrelated PD patients (2.5%). The three patients from the FTLD/parkinsonism family also carried this mutation. Within the control group, there were three heterozygous mutation carriers. During follow-up, one of these individuals developed motoneuron disease and another, a rapidly progressive dementia; the third remains healthy at the age of 79 but two close relatives developed motoneuron disease and dementia. The eight PD patients carrying the p.Ala382Thr mutation had all sporadic disease presentation. Their average onset age was 70.0 years (SD 9.4, range 51–79), which is later but not significantly different from that of the patients who did not carry this mutation. In conclusion, we expand the clinical spectrum associated with TARDBP mutations to FTLD with parkinsonism without motoneuron disease and to clinically definite PD. The TDP-43 protein might be directly involved in a broader neurodegenerative spectrum, including not only motoneuron disease and FTLD but also PD

    Atomic structures of TDP-43 LCD segments and insights into reversible or pathogenic aggregation.

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    The normally soluble TAR DNA-binding protein 43 (TDP-43) is found aggregated both in reversible stress granules and in irreversible pathogenic amyloid. In TDP-43, the low-complexity domain (LCD) is believed to be involved in both types of aggregation. To uncover the structural origins of these two modes of β-sheet-rich aggregation, we have determined ten structures of segments of the LCD of human TDP-43. Six of these segments form steric zippers characteristic of the spines of pathogenic amyloid fibrils; four others form LARKS, the labile amyloid-like interactions characteristic of protein hydrogels and proteins found in membraneless organelles, including stress granules. Supporting a hypothetical pathway from reversible to irreversible amyloid aggregation, we found that familial ALS variants of TDP-43 convert LARKS to irreversible aggregates. Our structures suggest how TDP-43 adopts both reversible and irreversible β-sheet aggregates and the role of mutation in the possible transition of reversible to irreversible pathogenic aggregation

    Transgenic Rat Model of Neurodegeneration Caused by Mutation in the TDP Gene

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    TDP-43 proteinopathies have been observed in a wide range of neurodegenerative diseases. Mutations in the gene encoding TDP-43 (i.e., TDP) have been identified in amyotrophic lateral sclerosis (ALS) and in frontotemporal lobe degeneration associated with motor neuron disease. To study the consequences of TDP mutation in an intact system, we created transgenic rats expressing normal human TDP or a mutant form of human TDP with a M337V substitution. Overexpression of mutant, but not normal, TDP caused widespread neurodegeneration that predominantly affected the motor system. TDP mutation reproduced ALS phenotypes in transgenic rats, as seen by progressive degeneration of motor neurons and denervation atrophy of skeletal muscles. This robust rat model also recapitulated features of TDP-43 proteinopathies including the formation of TDP-43 inclusions, cytoplasmic localization of phosphorylated TDP-43, and fragmentation of TDP-43 protein. TDP transgenic rats will be useful for deciphering the mechanisms underlying TDP-43–related neurodegenerative diseases
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