Chitosan nanofibrous materials for chemical and biological protection

2018 ◽  
Vol 1 ◽  
pp. 251522111878837 ◽  
Author(s):  
Mukesh Kumar Sinha ◽  
Biswa Ranjan Das

Chitosan derivatives are difficult to electrospun because they have poor flexibility of their polyelectrolyte chains. Based on extensive trails, we have successfully electrospun chitosan polymer and, subsequently, coated on non-woven polypropylene utilizing Nanospider technology. This experimentally developed nanofibrous webs of various densities were coated on non-woven fabric and, subsequently, stitched with activated carbon sphere (ACS) adhered composite fabric. Biological filtration and chemical protection were evaluated and the optimized density offering the highest value with meeting specified comfort was assessed. Results showed that optimized web morphology of 0.43 g m−2 is the best for integration with nuclear, biological and chemical absorbent layer of low ACS add-on in all aspects of comfort and protective behaviours. This will be meeting stringent defence protective requirements and lowering down the weight of suit by approximately 25%. An attempt has also been made in this research to protect from sulphur mustard chemical warfare agent by using both theories: (a) barrier techniques and (b) disintegrating the trapped molecules via functionalization of the web. Result shows that first molecules get trapped by in web layer (barrier effect) and subsequently destroyed by hydrolysis mechanism. Scanning microscopic image shows web is acting as barrier layer by trapping sulphur mustard particles. Optimized web of 0.43 g m−2 was functionalized with zinc (Zn) oxide and the presence of Zn particles was confirmed by imaging techniques. Crystalline and thermal analysis depicts that structural changes were found in sulphur mustard spotted functionalized web. Raman spectra show chemically disintegrated hydrolysed products of sulphur mustard. Bacterial filtration efficiency, antimicrobial and comfort properties were measured for assessing the introduction of nanowebs for biological protection and chemical protection in newly created multilayered fabric structure with low ACS add-on (180 g m−2). The initial encouraging outcome of this research expects whether the multilayered fabric could be introduced in the suit.

2011 ◽  
Vol 7 (3) ◽  
pp. 225
Author(s):  
Gianfranco Sinagra ◽  
Michele Moretti ◽  
Giancarlo Vitrella ◽  
Marco Merlo ◽  
Rossana Bussani ◽  
...  

In recent years, outstanding progress has been made in the diagnosis and treatment of cardiomyopathies. Genetics is emerging as a primary point in the diagnosis and management of these diseases. However, molecular genetic analyses are not yet included in routine clinical practice, mainly because of their elevated costs and execution time. A patient-based and patient-oriented clinical approach, coupled with new imaging techniques such as cardiac magnetic resonance, can be of great help in selecting patients for molecular genetic analysis and is crucial for a better characterisation of these diseases. This article will specifically address clinical, magnetic resonance and genetic aspects of the diagnosis and management of cardiomyopathies.


2021 ◽  
Vol 23 (9) ◽  
Author(s):  
Andrea Di Matteo ◽  
Gianluca Smerilli ◽  
Edoardo Cipolletta ◽  
Fausto Salaffi ◽  
Rossella De Angelis ◽  
...  

Abstract Purpose of Review To highlight the potential uses and applications of imaging in the assessment of the most common and relevant musculoskeletal (MSK) manifestations in systemic lupus erythematosus (SLE). Recent Findings Ultrasound (US) and magnetic resonance imaging (MRI) are accurate and sensitive in the assessment of inflammation and structural damage at the joint and soft tissue structures in patients with SLE. The US is particularly helpful for the detection of joint and/or tendon inflammation in patients with arthralgia but without clinical synovitis, and for the early identification of bone erosions. MRI plays a key role in the early diagnosis of osteonecrosis and in the assessment of muscle involvement (i.e., myositis and myopathy). Conventional radiography (CR) remains the traditional gold standard for the evaluation of structural damage in patients with joint involvement, and for the study of bone pathology. The diagnostic value of CR is affected by the poor sensitivity in demonstrating early structural changes at joint and soft tissue level. Computed tomography allows a detailed evaluation of bone damage. However, the inability to distinguish different soft tissues and the need for ionizing radiation limit its use to selected clinical circumstances. Nuclear imaging techniques are valuable resources in patients with suspected bone infection (i.e., osteomyelitis), especially when MRI is contraindicated. Finally, dual energy X-ray absorptiometry represents the imaging mainstay for the assessment and monitoring of bone status in patients with or at-risk of osteoporosis. Summary Imaging provides relevant and valuable information in the assessment of MSK involvement in SLE.


2018 ◽  
Vol 19 (12) ◽  
pp. 3702 ◽  
Author(s):  
Grazia Femminella ◽  
Tony Thayanandan ◽  
Valeria Calsolaro ◽  
Klara Komici ◽  
Giuseppe Rengo ◽  
...  

Alzheimer’s disease is the most common form of dementia and is a significant burden for affected patients, carers, and health systems. Great advances have been made in understanding its pathophysiology, to a point that we are moving from a purely clinical diagnosis to a biological one based on the use of biomarkers. Among those, imaging biomarkers are invaluable in Alzheimer’s, as they provide an in vivo window to the pathological processes occurring in Alzheimer’s brain. While some imaging techniques are still under evaluation in the research setting, some have reached widespread clinical use. In this review, we provide an overview of the most commonly used imaging biomarkers in Alzheimer’s disease, from molecular PET imaging to structural MRI, emphasising the concept that multimodal imaging would likely prove to be the optimal tool in the future of Alzheimer’s research and clinical practice.


2021 ◽  
Vol 31 (1) ◽  
pp. 10-16
Author(s):  
Laura Tapoi ◽  
Alexandra Clement ◽  
Rodica Radu ◽  
Radu Sascau

Arrhythmogenic cardiomyopathy, as it has been recently redefi ned, is characterized by progressive myocyte loss with fibrosis and fat infiltration of the myocardium, which finally leads to a broad clinical spectrum ranging from heart failure symptoms to sudden cardiac death. The diagnosis of arrhythmogenic cardiomyopathy is challenging particularly because of its heterogeneity in presentation, which varies from focal right ventricular involvement to biventricular or prominent left ventricular phenotype. In the past decades, the development of new electrocardiographic and imaging diagnostic criteria for arrhythmogenic cardiomyopathy constituted an important area of research and resulted in the elaboration of the Padua criteria. However, even with the widespread availability of modern imaging techniques, there is still a lack of awareness in the health care community and this pathology persist in being under-or misdiagnosed. Given the limited indication of endomyocardial biopsy for the diagnosis of arrhythmogenic cardiomyopathy, one can conclude that the progress that has been made in the last few years in the multimodality imaging field is of utmost importance for the early detection and proper treatment of patients with arrhythmogenic cardiomyopathy, providing valuable prognostic information.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1522-C1522
Author(s):  
Peter Blanchard ◽  
Brendan Kennedy ◽  
Chris Ling

Significant efforts have been made in the development of (Bi0.5Na0.5)TiO3 ferroelectrics as an alternative to the lead-based industry standard PbTi1-xZrxO3.[1] It has also been shown that doping the A- and B-site of (Bi0.5Na0.5)TiO3 can greatly improve the ferroelectric behavior of these materials,[2] possibly due to the formation of two or more ferroelectric phases at a morphotropic phase boundary (MPB). As such, there is a significant interest in understanding the structural changes in (Bi0.5Na0.5)TiO3-based solid solutions. (Bi0.5Na0.5)TiO3 was originally described as adopting a rhombohedral structure in space group R3c, However, the accuracy of this description has been greatly debated. It was recently suggested that (Bi0.5Na0.5)TiO3 actually adopts a monoclinic structure in space group Cc.[3] Given this recent controversy, we investigated the structural evolution of (Bi0.5Na0.5)TiO3-based solid solutions, particularly the (Bi0.5Na0.5)Ti1-xZrxO3 and (1-x)(Bi0.5Na0.5)TiO3–xBiFeO3 solid solutions., using both diffraction and spectroscopy techniques. Diffraction measurements on (Bi0.5Na0.5)TiO3 confirm that both monoclinic Cc and rhombohedral R3c phases are present at room temperature. Diffraction analysis showed that doping (Bi0.5Na0.5)TiO3 with a small amount of (Bi0.5Na0.5)ZrO3 and BiFeO3 can stabilizes the rhombohedral phase. The Ti/Fe K-edge and Zr L3-edge XANES spectra analysis was performed to determine the effects doping has on the local displacement of the B-site cations.


Author(s):  
Sunny Pannu ◽  
Meenakshi Ahirwar ◽  
Rishi Jamdigni ◽  
B. K. Behera

The woven fabrics containing cotton/spandex core spun yarns possesses very vital properties of stretch, recovery and thus shape retention from the view point of wearing comfort and garment appearance. Spandex present in the core of core spun yarn is the most essential performer behind these properties. An attempt is made in this research work to study the influence of changing spandex denier in core spun yarn on the stretch and functional properties of stretch woven fabrics. The sole objective of this study is to find out whether different stretch, shrinkage and physical properties of stretch woven fabrics depend upon changing spandex percentage achieved by means of change in spandex filament denier. It was observed that by increasing denier of spandex in core spun weft yarns the increase in weft shrinkage diminishes. Dual core weft with spandex provides good elongation percentage and recovery percentage. The fabric with higher denier spandex in yarn shows a decreasing total hand values trend for summer and winter. The results depicts that the fabrics have higher THV for winter suiting fabrics as compared to summer suiting thus are more suitable for the winter wear.


1998 ◽  
Vol 17 (7) ◽  
pp. 373-379 ◽  
Author(s):  
D J Andrew ◽  
C D Lindsay

1. Sulphur mustard (`mustard gas', HD) is a highly toxic chemical warfare agent which affects the skin and respiratory tract. The primary targets of inhaled HD are the epithelia of the upper respiratory tract. Hexamethylenetetramine (HMT) has been shown to protect human lung cells against HD toxicity and has also been shown to be effective in vivo against the chemical warfare agent phosgene. The ability of HMT to protect against the toxicity of HD was investigated in the human upper respiratory tract cell lines BEAS-2B and RPMI 2650. 2. HD was highly toxic to both cell lines, with LC50 values of 15 - 30 mM. HMT, at a concentration of 10 mM, was shown to protect the cell lines against the toxic effects of 20 mM and 40 mM HD. Results demonstrated that it was necessary for HMT to be in situ at the time of exposure to HD for effective cytoprotection. No protection was seen when cells were treated with HMT following exposure to HD, or where HMT was removed prior to HD exposure. 3. Results suggest that HMT may be effective prophylaxis for exposure to HD by inhalation.


2019 ◽  
Author(s):  
Katarzyna Gleń-Karolczyk ◽  

Horseradish roots, due to the content of many valuable nutrients and substances with healing and pro-health properties, are used more and more in medicine, food industry and cosmetics. In Poland, the cultivation of horseradish is considered minor crops. In addition, its limited size causes horseradish producers to encounter a number of unresolved agrotechnical problems. Infectious diseases developing on the leaves and roots during the long growing season reduce the size and quality of root crops. The small range of protection products intended for use in the cultivation of horseradish generates further serious environmental problems (immunization of pathogens, low effectiveness, deterioration of the quality of raw materials intended for industry, destruction of beneficial organisms and biodiversity). In order to meet the problems encountered by horseradish producers and taking into account the lack of data on: yielding, occurrence of infectious diseases and the possibility of combating them with methods alternative to chemical ones in the years 2012–2015, rigorous experiments have been carried out. The paper compares the impact of chemical protection and its reduced variants with biological protection on: total yield of horseradish roots and its structure. The intensification of infectious diseases on horseradish leaves and roots was analyzed extensively. Correlations were examined between individual disease entities and total yield and separated root fractions. A very important and innovative part of the work was to learn about the microbial communities involved in the epidemiology of Verticillium wilt of horseradish roots. The effect was examined of treatment of horseradish cuttings with a biological preparation (Pythium oligandrum), a chemical preparation (thiophanate-methyl), and the Kelpak SL biostimulator (auxins and cytokinins from the Ecklonia maxima algae) on the quantitative and qualitative changes occurring in the communities of these microorganisms. The affiliation of species to groups of frequencies was arranged hierarchically, and the biodiversity of these communities was expressed by the following indicators: Simpson index, Shannon–Wiener index, Shannon evenness index and species richness index. Correlations were assessed between the number of communities, indicators of their biodiversity and intensification of Verticillium wilt of horseradish roots. It was shown that the total yield of horseradish roots was on average 126 dt · ha–1. Within its structure, the main root was 56%, whereas the fraction of lateral roots (cuttings) with a length of more than 20 cm accounted for 26%, and those shorter than 20 cm for 12%, with unprofitable yield (waste) of 6%. In the years with higher humidity, the total root yield was higher than in the dry seasons by around 51 dt · ha–1 on average. On the other hand, the applied protection treatments significantly increased the total yield of horseradish roots from 4,6 to 45,3 dt · ha–1 and the share of fractions of more than 30 cm therein. Higher yielding effects were obtained in variants with a reduced amount of foliar application of fungicides at the expense of introducing biopreparations and biostimulators (R1, R2, R3) and in chemical protection (Ch) than in biological protection (B1, B2) and with the limitation of treatments only to the treatment of cuttings. The largest increments can be expected after treating the seedlings with Topsin M 500 SC and spraying the leaves: 1 × Amistar Opti 480 SC, 1 × Polyversum WP, 1 × Timorex Gold 24 EC and three times with biostimulators (2 × Kelpak SL + 1 × Tytanit). In the perspective of the increasing water deficit, among the biological protection methods, the (B2) variant with the treatment of seedlings with auxins and cytokinins contained in the E. maxima algae extract is more recommended than (B1) involving the use of P. oligandrum spores. White rust was the biggest threat on horseradish plantations, whereas the following occurred to a lesser extent: Phoma leaf spot, Cylindrosporium disease, Alternaria black spot and Verticillium wilt. In turn, on the surface of the roots it was dry root rot and inside – Verticillium wilt of horseradish roots. The best health of the leaves and roots was ensured by full chemical protection (cuttings treatment + 6 foliar applications). A similar effect of protection against Albugo candida and Pyrenopeziza brassicae was achieved in the case of reduced chemical protection to one foliar treatment with synthetic fungicide, two treatments with biological preparations (Polyversum WP and Timorex Gold 24 EC) and three treatments with biostimulators (2 × Kelpak SL, 1 × Tytanit). On the other hand, the level of limitation of root diseases comparable with chemical protection was ensured by its reduced variants R3 and R2, and in the case of dry root rot, also both variants of biological protection. In the dry years, over 60% of the roots showed symptoms of Verticillium wilt, and its main culprits are Verticillium dahliae (37.4%), Globisporangium irregulare (7.2%), Ilyonectria destructans (7.0%), Fusarium acuminatum (6.7%), Rhizoctonia solani (6.0%), Epicoccum nigrum (5.4%), Alternaria brassicae (5.17%). The Kelpak SL biostimulator and the Polyversum WP biological preparation contributed to the increased biodiversity of microbial communities associated with Verticillium wilt of horseradish roots. In turn, along with its increase, the intensification of the disease symptoms decreased. There was a significant correlation between the richness of species in the communities of microbial isolates and the intensification of Verticillium wilt of horseradish roots. Each additional species of microorganism contributed to the reduction of disease intensification by 1,19%.


2003 ◽  
Vol 285 (2) ◽  
pp. L269-L280 ◽  
Author(s):  
Cindy Lawler ◽  
William A. Suk ◽  
Bruce R. Pitt ◽  
Claudette M. St. Croix ◽  
Simon C. Watkins

The recent resurgence of interest in the use of intravital microscopy in lung research is a manifestation of extraordinary progress in visual imaging and optical microscopy. This review evaluates the tools and instrumentation available for a number of imaging modalities, with particular attention to recent technological advances, and addresses recent progress in use of optical imaging techniques in basic pulmonary research. 1 Limitations of existing methods and anticipated future developments are also identified. Although there have also been major advances made in the use of magnetic resonance imaging, positron emission tomography, and X-ray and computed tomography to image intact lungs and while these technologies have been instrumental in advancing the diagnosis and treatment of patients, the purpose of this review is to outline developing optical methods that can be evaluated for use in basic research in pulmonary biology.


2020 ◽  
Vol 49 (1_suppl) ◽  
pp. 126-140
Author(s):  
C.J. Martin

The International Commission on Radiological Protection (ICRP) developed effective dose as a quantity related to risk for occupational and public exposure. There was a need for a similar dose quantity linked to risk for making everyday decisions relating to medical procedures. Coefficients were developed to enable the calculation of doses to organs and tissues, and effective doses for procedures in nuclear medicine and radiology during the 1980s and 1990s. Effective dose has provided a valuable tool that is now used in the establishment of guidelines for patient referral and justification of procedures, choice of appropriate imaging techniques, and providing dose data on potential exposure of volunteers for research studies, all of which require the benefits from the procedure to be weighed against the risks. However, the approximations made in the derivation of effective dose are often forgotten, and the uncertainties in calculations of risks are discussed. An ICRP report on protection dose quantities has been prepared that provides more information on the application of effective dose, and concludes that effective dose can be used as an approximate measure of possible risk. A discussion of the way in which it should be used is given here, with applications for which it is considered suitable. Approaches to the evaluation of risk and methods for conveying information on risk are also discussed.


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