China
Africa
Explore chapters and articles related to this topic
Inorganic Particulates in Human Lung: Relationship to the Inflammatory Response
Published in William S. Lynn, Inflammatory Cells and Lung Disease, 2019
Victor L. Roggli, J. P. Mastin, John D. Shelburne, Michael Roe, Arnold R. Brody
Epidemiologic studies have implicated non-fibrous silicates, such as kaolinite, montmorillonite (Fuller’s earth), and micas as having a role in pulmonary disease, but the pathogenicity of the silicates themselves, as opposed to silica or asbestos which may be present as contaminants, is controversial.106 Recent evidence suggests that platy talc uncontaminated by asbestos or quartz may be fibrogenic in individuals exposed to high doses over long periods of time.3 Talc has been identified in human lung tissues in a number of studies.3, 4, 6, 107 Kaolinite has been identified in the lungs of kaolin workers,108 individuals with other pneumoconioses,47 and in cigarette smoke as well as in alveolar macrophages obtained from the lungs of cigarette smokers.109 Other non-fibrous silicates which have been identified in human lung tissue include illite,6, 78 pyrophyllite,6, 47 and montmorillonite6 among the clay minerals; leucite among the feldspathoid;6, 110 muscovite and biotite among the micas;6, 111 chlorite and vermiculite among the chlorites;6 andalousite6 and zirconium9 among the nesosilicates; and cordierite6 (a sorosilicate). Coal fly ash, which consists of an outer amorphous glass phase, aggregated mullite fibers, and occasionally contains other elements such as iron, titanium, calcium, and phosphorus, has been identified in human lung in a single instance.112 The relative pathogenicity of most of these minerals is at present unknown. In general, their identification requires a combination of energy dispersive X-ray analytical and microdiffraction techniques. As additional studies are performed, the list of non-fibrous silicates identified in human lung tissue will undoubtedly continue to increase.
Hirak Bhasma: A Potential Ayurvedic Antibacterial Drug Assessed by In Vitro Pre-Clinical Studies
Published in P. Mereena Luke, K. R. Dhanya, Didier Rouxel, Nandakumar Kalarikkal, Sabu Thomas, Advanced Studies in Experimental and Clinical Medicine, 2021
Sutapa Som Chaudhury, Bhuban Ruidas, Prasanta Kumar Sarkar, Chitrangada Das Mukhopadhyay
In the current scenario, the multi-drug resistance (MDR) of pathogenic bacterial strains has already rung an alarm to the treatment of nosocomial infections [1]. The overuses of broad-spectrum antibiotics and their prolonged applications are making the situation worsen day by day [2, 3]. Since last, few decades’ combinatorial therapies are being proposed to combat MDR bacterial strains [4]. But the use of antibiotics in combinations is also in vain because the question has already been raised whether we are currently in the post-antibiotic era [5]. The increasing resistance to the antibiotics available until date necessitates the use of biocompatible natural compounds as an alternative medicine to combat bacterial pathogenesis without any side effects. Nowadays natural compound based Ayurvedic preparations are widely accepted as an effective antimicrobial drug [6, 7]. In Ayurveda, the traditional Indian medical system, Hirak Bhasma (HB) is such a preparation. This Ayurvedic medicine is mainly composed of Hirak, i.e., diamond dust. HB is prescribed for treating immunity disorders, crippling rheumatoid arthritis, bone marrow depression, cancer, and so on [8]. Here, we report a novel preparation of HB as a nano-drug component and its thorough in vitro evaluation for the pre-clinical assessment as an effective anti-bacterial drug candidate. Although, it has been claimed that HB is highly potential as an adaptogenic, antibacterial, anti-inflammatory, and immunomodulatory drug, no scientific evidence is available in support of this claim [9]. Metallic sources including sulfide-bearing minerals, metal oxides, and alumina silicates like biotite mica, chalcopyrite, and others have been used in traditional preparation as metallic antimicrobial sources. Interestingly, the antimicrobial function of metallic preparations is best achieved when the metal ions are effectively blended with the organic molecules [10, 11]. None the organic compounds alone or the metals singly can construct a highly effective antimicrobial drug. Ag, Au nanoparticles have also been in the limelight since few decades but anyone metal formula as a sole composition of an antimicrobial drug candidate may appear with the drawbacks of intense side effects [12, 13]. Destruction of pathogenic microbes via an elevated level of reactive oxygen species (ROS) is one of the prime mechanisms of these metal-based drug candidates, but this comes with the uncontrolled damage of the neighboring healthy cells in patients [14]. Here lies the importance of a perfect blend of organic compounds along with the trace metal components as in the HB. Being a balanced source of mineral components such as Zn, Cr which is effective against pathogenic microbes, the nanoformulation of HB may pave the path towards an alternative medicine in this premise [15, 16]. Also, HB is prescribed in Ayurveda to rejuvenate the body and mind [17]. This seems to be an advantage to regain the potentiation of the body in the disease condition such as bacteremia. But these claims need a scientific support. This work reports the lagging scientific documentation for HB as an antibacterial agent.
Exposure to artificial daylight or UV irradiation (A, B or C) prior to chemical cleaning: an effective combination for removing phototrophs from granite
Published in Biofouling, 2018
J. Santiago Pozo-Antonio, Patricia Sanmartín
A naturally colonized granite slab (disc-cutting finish) of dimensions 100 × 80 × 4 cm, blackened due to the presence of an extensive homogeneous biological patina, was selected for study (Figures 1 and 2A). The granite slab was obtained from a stone processing plant in NW Spain and was left outdoors for five years. This stone, quarried in the municipality of Mondariz, Galicia (NW Spain) and referred to as Rodas, is of great commercial value in the area and is commonly used in heritage buildings. Rodas is an equigranular panalotriomorphic adamellite characterized by medium-to-fine grain of maximum size 3 mm. It is texturally irregular due to the heterogranular nature of the quartz, which occurs as recrystallized quartz in intercrystalline spaces or as phenocrystals (Feijoó et al. 2013). The modal composition comprises plagioclase (30%), quartz (26%), alkaline feldspar (microcline-16%), muscovite (12%) and biotite (8%) as main minerals (IGME 1981). The physical properties are summarized as follows: open porosity (following RILEM 1980), 5.90% (v v–1); total porosity (mercury injection), 6.38% (v v–1); water absorption coefficient (under pressure) (following RILEM 1980), 2.37% (ww–1); water absorption coefficient (by capillarity) (following RILEM 1981), 2.17% (ww–1); apparent bulk density, 2,493.96 kg m−3 and real density, 2,650.36 kg m−3 (Feijoó et al. 2013). The pore size distribution is characterized by the three types of porosity corresponding to the typical trans-granular, inter-granular and intra-granular fissures (Mosquera et al. 2000).
Improving the 6-Aminopenicillanic acid release process using vermiculite-alginate biocomposite bead on drug delivery system
Published in Drug Development and Industrial Pharmacy, 2021
Nona Soleimanpour moghadam, Amirreza Azadmehr, Ardeshir Hezarkhani
The XRD pattern of VMT, VMT-Alg, and VMT-Alg-6APA composites demonstrated that the main crystalline compounds in these samples were quartz (SiO2), biotite, and vermiculite minerals (Figure 4). The presence of quartz and biotite in the VMT sample has been reported in other investigations [47]. The major 001 reflections of the vermiculite and biotite crystals were found at 2θ = 6.88° and 2θ = 8.47° in both compounds, respectively. After loading of Alg, no change in the d001-value of biotite and quartz was observed. The XRD analysis revealed that the intensity of VMT crystals diffraction lines was more than the intensity of biotite and quartz crystals diffraction lines. It seems that the loading of alginate onto vermiculite provided better diffraction for vermiculite. Vermiculite mineral showed a major broad reflection at d001 = 8.47 Å for VMT and d001 = 12.84 Å for VMT-Alg, but its intensity was weakened drastically after loading. Actually, no changes were observed at the main interlayer space of vermiculite mineral in presence of alginate. It could be concluded that the alginate has not been intercalated into interlayers of crystal planes of samples. This can be explained by the fact that molecules Alg are not capable to enter the silicate layers of VMT due to the repulsive forces between negatively charged clay surfaces and carboxylic groups of the polymer [35]. After loading of 6-APA in VMT-Alg, a shift in reflection from 6.88 to 7.29 was observed with increasing in d001-value, about 4.4 Å, from 12.84 Å to 17.25 Å, which attributed to the favored intercalation of the drug into the interlayer space. These phenomena are confirmed by other studies [2,24].
Toxic uranium contamination in groundwater of Thoothukudi district, India: Evaluation of health risks using the geochemical and statistical approach
Published in Toxin Reviews, 2023
Velayutham Raja, Mallanpillai Ananthakrishnan Neelakantan
Thoothukudi district is located on Tamilnadu’s southeast side and covers 4,707 sq. km. It is located at 8°18′57″ to 9°21′43″ N latitude and 77°39′21″ to 78°22′01″ E longitude (Figure 1). This district is bounded by Tirunelveli district (on the west), Bay of Bengal (on the east and southeast), Kanniyakumari district (on the southwest), Virudhunagar district (on the northwest), and Ramanathapuram district (on the northeast). This district receives a predominant rainfall during the northeast monsoon and average rainfall of about 570–740 nm. The annual average minimum and maximum temperatures are 23 °C and 29 °C, respectively (CGWB 2009). The surface water sources (Vaipar, Tambraparani, and Karamanaiyar rivers) are available during the monsoon seasons but dry during the summer (Kumar and Balukkarasu 2018). People from this district depend on groundwater for drinking, irrigation, and industrial purposes during the summer season. This district has many industrial activities such as thermal power plants, heavy water plants, cotton and staple yarn, caustic soda, fertilizers, soda ash, and carbon dioxide gas production (Suganya 2020). The major geological formation of this district is hornblende biotite gneiss. After this formation, charnockite and granite are predominant in the study area (Figure 2). The higher uranium concentration has been observed in the granitic gneiss region of South India due to the mineral dissolution controlled by hydrochemical parameters such as redox conditions, pH, and carbonate species (Lapworth et al.2021). Jhunjhunu district of Rajasthan reported a lower uranium concentration in the groundwater due to the scavenging of uranium by the iron-bearing sulfide rocks (Punia et al. 2021). Hence the uranium measurements in the study area are vital. This district’s major soils are black, red, and sandy soil. This district has 861 sq. km irrigated using dug wells, tube wells, tanks, and canals (CGWB 2009).