China 
Africa 
Explore chapters and articles related to this topic
Algae as a Source of Polysaccharides and Potential Applications
Published in Sanjeet Mehariya, Shashi Kant Bhatia, Obulisamy Parthiba Karthikeyan, Algal Biorefineries and the Circular Bioeconomy, 2022
Sonal Tiwari, E Amala Claret, Vikas S. Chauhan
Polysaccharides derived from the red alga Gelidium robustum protect embryonic eggs against the mumps virus and influenza B (Gerber et al., 1958). Sulfated polysaccharides (SPs) have been found to hinder the reproduction of enveloped viruses. Before infection, viruses must make contact with cell membrane glycosaminoglycan receptors (GAG), such as heparin sulfate (HS), to enter their host cell. SPs are negatively charged polymers and are chemically identical to HS. SPs hinder viral particle attachment by forming virus-algal PS complex by imitating GAG, eventually protecting the cell from infection (De Jesus Raposo et al., 2015). Carrageenan nasal spray exhibits considerable antiviral activity against three virus subgroups, HRV, human coronavirus, and influenza A virus, with the most significant efficacy reported in patients infected with the human coronavirus (Koenighofer et al., 2014). Polyguluronate sulfate (PGS), a low molecular weight sulfated brown algal polysaccharide, can block the production and secretion of hepatitis B surface antigens HBsAg and HBeAg (Chen et al., 2020). Sulfated polysaccharides from algae might be used as antiviral therapeutics against SARS-CoV-2 (Pereira and Critchley, 2020).
Disorders of Hearing
Published in Anthony N. Nicholson, The Neurosciences and the Practice of Aviation Medicine, 2017
Linda M. Luxon, Ronald Hinchcliffe
With increased international travel for business and leisure, infections commonly encountered and tropical infections are relevant to aircrew. Bacterial, viral and myototic infections may give rise to hearing impairment by direct invasion, blood-borne transmission or by transfer along the nerves from the cerebrospinal compartment. In adults, sudden sensorineural hearing loss is usually attributed to viral or vascular pathology. Westmore et al. (1979) reported the detection of mumps virus in the perilymph after sudden-onset deafness, and there is circumstantial evidence to suggest that sudden hearing loss may be associated with a variety of viruses.
Membrane-Based Separation Processes
Published in Pau Loke Show, Chien Wei Ooi, Tau Chuan Ling, Bioprocess Engineering, 2019
Kit Wayne Chew, Bervyn Qin Chyuan Tan, Jiang Chier Bong, Kevin Qi Chong Hwang, Pau Loke Show
Membrane chromatography that are equipped with functionalized ligands ceases with the need of diffusivity from bulk mixture to the adsorption sites. The diffusion process is very slow as compared to the convective flow involved in membrane chromatography. Theoretically, membrane chromatography should exceed efficiencies of conventional chromatography by factors of ten or higher. However, certain anomalies in mass transfer effects slowing down the process, such as dead spaces and nonuniform flow, have been observed (Pabby et al., 2015). With regard to technical issues, ligands available currently are largely from existing molecules rather than being specifically designed, or they are ligates that are marked to have interactions with current ligands such as histidine tagging. Besides, specificity of most current ligands cannot be tuned sufficiently to meet requirements, while naturally specific ligands such as antibodies are unstable and expensive. The problems associated with stability of immunoaffinity ligands are the harsh environment during the elution process. Brgles et al. (2016) managed to utilize amino acid buffers to elute mumps virus at neutral pH, which is favorable for sensitive ligands (Brgles et al., 2016). Immunoaffinity ligands can cost upward of a few hundred dollars per milligram (Kress-Rogers, 1996), and their sensitivity and fragility prevents multiple uses. This causes capital cost to increase due to the mandatory oversizing of chromatography columns (Roy and Gupta, 2006). Membrane chromatography in general has lower binding capacity compared to their packed bed counterparts. To solve this issue, the membrane needs to have higher specific area, but this affects other properties such as permeability, pore size distribution, and mechanical strength. The most widely studied solutions to this issue are spacer arms, membrane supports, and pore coatings. The pore coatings create a three-dimensional area to increase binding surface (Ghosh, 2002).
Characterization of performance and disinfection resilience of nonwoven filter materials for use in 3D-printed N95 respirators
Published in Journal of Occupational and Environmental Hygiene, 2021
Patrick T. O’Shaughnessy, Brian Strzelecki, Monica Ortiz-Hernandez, Patrick Aubin, Xuefang Jing, Qing Chang, Jinhua Xiang, Peter S. Thorne, Jack T. Stapleton
Previous research efforts by this study team had proven that the Stopgap SFM mask itself could be effectively disinfected (Welch et al. 2021). Here, viral inactivation tests on filter media were also conducted after utilizing a variety of disinfection methods. To determine the effectiveness of chemical inactivation of diverse viral pathogens, virus preparations were applied to the C4 combination and treated with a single application of bleach, hydrogen peroxide, isopropyl alcohol, or quartenary amine and residual infectious virus measured. Two human positive strand, RNA coronaviruses (SARS-CoV-2 and 229E-CoV), one murine coronavirus (MHV-CoV), one negative strand RNA virus (mumps virus), one single-strand DNA virus (vaccinia virus), and one double-strand DNA virus (adenovirus) were evaluated. All are enveloped viruses except adenovirus. Additional details concerning the viruses applied to the filter media and the disinfection methods are given in Supplement Part C.
On the interpretation of bioaerosol exposure measurements and impacts on health
Published in Journal of the Air & Waste Management Association, 2019
Hamza Mbareche, Lidia Morawska, Caroline Duchaine
Infectious diseases are caused by bacteria, fungi, and viruses. When any of these become airborne, they can be transmitted to humans via the air. Among bacteria, legionellosis, tuberculosis, and anthrax are infectious diseases that constitute significant public health concerns due to their infectivity even at low doses. Legionella pneumophila, the etiological agent of legionellosis, can be aerosolized from contaminated water (Rowbotham 1980). Tuberculosis patients can transmit Mycobacterium tuberculosis in droplet nuclei by coughing, sneezing, and talking (Pearson et al. 1992). Anthrax, which is often linked to bioterrorism, is caused by the inhalation of Bacillus anthracis spores (Jernigan et al. 2001). Other examples of bacterial infection through aerosols include Chlamydia psittaci and Pseudomonas aeruginosa (Lyczak, Cannon, and Pier 2000; Morawska 2006). The most common invasive fungal infections are aspergillosis (Aspergillus fumigatus), candidiasis (Candida albicans), cryptococcosis (Cryptococcus neoformans), mucormycosis (Rhizopus oryzae), pneumocystis (Pneumocystis jirovecii), coccidioidomycosis (Coccodioides immitis), histoplasmosis (Histoplasma capsulatum), paracoccodioidomycosis (Paracoccidioides brasilliensis), and penicilliosis (Penicillium marneffei), all of which can be transmitted through aerosol spore exposure (Brown et al. 2012). Finally, viruses that are readily transmitted by bioaerosols include severe acute respiratory syndrome (SARS) virus, enteric viruses, respiratory syncytial virus (RSV), hantavirus, varicella–zoster virus, mumps virus, rubella virus, and influenza A and B viruses (Bonifait et al. 2015; Gershon 2008; Hjelle and Glass 2000; Lindsley et al. 2010; Matricardi et al. 2000; Tellier 2009; Teltsch and Katzenelson 1978; Uyeki, Bresee 2007; Booth et al. 2005). It was suggested that other viruses, such as norovirus, could reach human’s digestive system through inhalation and swallowing (Bonifait et al. 2015). Although obvious evidence of viral airborne transmission is available, the Centers for Disease Control and Prevention (CDC) are still skeptical about the subject of airborne transmission from one patient to the other (CDC 2018).