The widespread of viral airborne diseases is becoming a critical problem for human health and safety, not only for the common cold and flu, but also considering more serious infection as the current ...pandemic COVID-19. Even if the current heating, ventilating and air conditioning (HVAC) systems limit the disease transmission by air, the air filters are susceptible to microbial colonization. In addition, viruses spread via droplets (aerosol) produced by direct or indirect contact with infected people. In this context, the necessity of an efficient HVAC system, able to capture and inactivate viruses- and bacteria-rich aerosols, thus preserving a safe indoor air environment and protecting people, is of enormous importance. The aim of this work is the assessment of the antiviral properties of a silver nanoclusters/silica composite coating deposited via co-sputtering technique on glass, on metallic fibre-based air filters as well as on cotton textiles. The selected human respiratory viruses are: respiratory syncytial virus (RSV), the human rhinovirus (HRV) and the influenza virus type A (FluVA). The coated air filters show that the nanostructured coating develops a strong virucidal activity against RSV and FluVA, but not against the HRV.
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•Nanostructured composite coating was deposited on air filter via co-sputtering.•The coating is composed of silver nanoclusters in a silica matrix.•The antiviral properties of the composite coating were assessed.•The three viruses are selected among human respiratory viruses.
The airborne transmission of SARS-CoV-2 remains surprisingly controversial; indeed, health and regulatory authorities still require direct proof of this mode of transmission. To close this gap, we ...measured the viral load of SARS-CoV-2 of an infected subject in a hospital room (through an oral and nasopharyngeal swab), as well as the airborne SARS-CoV-2 concentration in the room resulting from the person breathing and speaking. Moreover, we simulated the same scenarios to estimate the concentration of RNA copies in the air through a novel theoretical approach and conducted a comparative analysis between experimental and theoretical results. Results showed that for an infected subject's viral load ranging between 2.4 × 106 and 5.5 × 106 RNA copies mL-1, the corresponding airborne SARS-CoV-2 concentration was below the minimum detection threshold when the person was breathing, and 16.1 (expanded uncertainty of 32.8) RNA copies m-3 when speaking. The application of the predictive approach provided concentrations metrologically compatible with the available experimental data (i.e. for speaking activity). Thus, the study presented significant evidence to close the gap in understanding airborne transmission, given that the airborne SARS-CoV-2 concentration was shown to be directly related to the SARS-CoV-2 emitted. Moreover, the theoretical analysis was shown to be able to quantitatively link the airborne concentration to the emission.
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•The airborne transmission of SARS-CoV-2 remains surprisingly controversial.•A direct proof of SARS-CoV-2 airborne transmission is still required.•The link between emission and airborne concentration is experimentally demonstrated.•A theoretical approach estimating SARS-CoV-2 airborne concentrations is validated.•The measurement of airborne SARS-CoV-2 concentration presents high uncertainties.
Dextran nanobubbles were prepared with a dextran shell and a perfluoropentan core in which oxygen was stored. To increase the stability polyvinylpirrolidone was also added to the formulation as ...stabilizing agent. Rhodamine B was used as fluorescent marker to obtain fluorescent nanobubbles. The nanobubble formulations showed sizes of about 500
nm, a negative surface charge and a good capacity of loading oxygen, no hemolytic activity or toxic effect on cell lines. The fluorescent labelled nanobubbles could be internalized in Vero cells. Oxygen-filled nanobubbles were able to release oxygen in different hypoxic solutions at different time after their preparation in
in vitro experiments. The oxygen release kinetics could be enhanced after nanobubble insonation with ultrasound at 2.5
MHz. The oxygen-filled nanobubble formulations might be proposed for therapeutic applications in various diseases.
A new nanoparticulate system for foscarnet delivery was prepared and evaluated. Nanoparticles were obtained by ionotropic gelation of chitosan induced by foscarnet itself, acting as an ionotropic ...agent in a manner similar to tripolyphosphate anion. A Doehlert design allowed finding the suitable experimental conditions. Nanoparticles were between 200 and 300nm in diameter (around 450nm after redispersion). Nanoparticle size increased after 5h, but no size increase was observed after 48h when nanoparticles were crosslinked with glutaraldehyde. Zeta potential values of noncrosslinked and crosslinked nanoparticles were between 20 and 25mV, while drug loading of noncrosslinked nanoparticles was about 40% w/w (55% w/w for crosslinked nanoparticles). Nanoparticle yield was around 25% w/w. Crosslinked nanoparticles showed a controlled drug release. Foscarnet released from nanoparticles maintained the antiviral activity of the free drug when tested in vitro against lung fibroblasts (HELF) cells infected with HCMV strain AD-169. Moreover, nanoparticles showed no toxicity on non-infected HELF cells. These nanoparticles may represent a delivery system that could improve the therapeutic effect of foscarnet.
Oxysterols are products of enzymatic and/or chemical cholesterol oxidation. While some of the former possess broad antiviral activities, the latter mostly originate from the deterioration of the ...nutritional value of foodstuff after exposure to heat, light, radiation and oxygen, raising questions about their potential health risks. We evaluated the presence of selected oxysterols in bovine colostrum and monitored the evolution of their cholesterol ratio throughout an entire industrial-scale milk production chain and after industrially employed storage procedures of milk powders. We report here for the first time the presence of high levels of the enzymatic oxysterol 27-hydroxycholesterol (27OHC) in concentrations of antiviral interest in bovine colostrum (87.04 ng mL
−1
) that decreased during the first postpartum days (56.35 ng mL
−1
). Of note, this oxysterol is also observed in milk and milk products and is not negatively affected by industrial processing or storage. We further highlight an exponential increase of the non-enzymatic oxysterols 7β-hydroxycholesterol (7βOHC) and 7-ketocholesterol (7KC) in both whole (WMPs) and skimmed milk powders (SMPs) during prolonged storage, confirming their role as reliable biomarkers of cholesterol oxidation over time: after 12 months, 7βOHC reached in both SMPs and WMPs amounts that have been found to be potentially toxic
in vitro
(265.46 ng g
−1
and 569.83 ng g
−1
, respectively). Interestingly, industrial processes appeared to affect the generation of 7βOHC and 7KC differently, depending on the presence of fat in the product: while their ratios increased significantly after skimming and processing of skimmed milk and milk products, this was not observed after processing whole milk and milk cream.
Oxysterols are products of enzymatic and/or chemical cholesterol oxidation. Their measurement during and after a milk production chain could represent a useful tool to monitor and increase the commercial and nutritional value of milk.
The functionalization of single-walled carbon nanotubes (SWCNTs) via microwave-assisted grafting reactions enables efficient multidecoration in a single step. A novel water-soluble SWCNT platform was ...prepared via the simple 1,3-dipolar cycloaddition of azomethine ylides under dielectric heating. Thanks to a single grafting reaction the CNT surface binds in a 1 : 1 ratio an amino acidic β-cyclodextrin (β-CD) derivative and the DOTAMA moiety (1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid monoamide). This novel "one shot" synthesis, compared with multistep functionalizations, preserves the SWCNT's structural integrity (TEM images). Besides thermogravimetric analyses, the determination of the amount of β-CD and DOTA moieties grafting onto the SWCNT's surface was performed on the basis of phenolphthalein and gadolinium complexation, respectively.
Summary
Objective: This study investigates affective and sexual dimensions in partners involved as caregivers of Alzheimer dementia (AD) subjects. A negative correlation between burden of the ...caregiver and sexual‐affective quality of life was assumed.
Design and methods: Hundred participants with AD partner (33 male, 67 female), aged between 55 and 85 years were recruited and data were collected from the Caregiver Burden Inventory scale and a semi‐structured interview that included demographic information, medical history, relationship and sexual satisfaction, and current sexual function. AD group was compared with a control group (CG) (N = 100) matched for age, sex, education and marital status on measures of the semi‐structured interview. Data were analysed using frequency count, univariate analysis (chi‐squared and ANOVA) and bivariate correlation.
Results: The findings revealed that mean burden level was 31.59 (SD 19.51). A difference between experimental and CGs was found for sexual and affective marital satisfaction (p < 0.05). The same variables showed a rather negative correlation with total burden levels (r = −0.374, p < 0.001; r = −0.448, p < 0.001).
Tinkering with a viral ribonucleotide reductase Lembo, David; Brune, Wolfram
Trends in biochemical sciences (Amsterdam. Regular ed.),
2009, 2009-Jan, 2009-1-00, 20090101, Letnik:
34, Številka:
1
Journal Article
Recenzirano
Ribonucleotide reductase (RNR), a crucial enzyme for nucleotide anabolism, is encoded by all living organisms and by large DNA viruses such as the herpesviruses. Surprisingly, the β-herpesvirus ...subfamily RNR R1 subunit homologues are catalytically inactive and their function remained enigmatic for many years. Recent work sheds light on the function of M45, the murine cytomegalovirus R1 homologue; during viral evolution, M45 apparently lost its original RNR activity but gained the ability, via inhibiting RIP1, a cellular adaptor protein, to block cellular signaling pathways involved in innate immunity and inflammation. The discovery of this novel mechanism of viral immune subversion provides further support to the concept of evolutionary tinkering.
A new poly(amidoamine)-cholesterol (PAA-cholesterol) conjugate was synthesized, characterized and used to produce nanoparticles by the electrospraying technique. The electrospraying is a method of ...liquid atomization that consists in the dispersion of a solution into small charged droplets by an electric field. Tuning the electrospraying process parameters spherical PAA-chol nanoparticles formed. The PAA-cholesterol nanoparticles showed sizes lower than 500 nm and spherical shape. The drug incorporation capacity was investigated using tamoxifen, a lipophilic anticancer drug, as model drug. The incorporation of the tamoxifen did not affect the shape and sizes of nanoparticles showing a drug loading of 40%. Tamoxifen-loaded nanoparticles exhibited a higher dose-dependent cytotoxicity than free tamoxifen, while blank nanoparticles did not show any cytotoxic effect at the same concentrations. The electrospray technique might be proposed to produce tamoxifen-loaded PAA-chol nanoparticle in powder form without any excipient in a single step.
The human cytomegalovirus Landolfo, Santo; Gariglio, Marisa; Gribaudo, Giorgio ...
Pharmacology & therapeutics (Oxford)
98, Številka:
3
Journal Article
Recenzirano
Human cytomegalovirus (HCMV), a betaherpesvirus, represents the major infectious cause of birth defects, as well as an important pathogen for immunocompromised individuals. The viral nucleocapsid ...containing a linear double-stranded DNA of 230 kb is surrounded by a proteinaceous tegument, which is itself enclosed by a loosely applied lipid bilayer. Expression of the HCMV genome is controlled by a cascade of transcriptional events that leads to the synthesis of three categories of viral proteins designated as immediate-early, early, and late. Clinical manifestations can be seen following primary infection, reinfection, or reactivation. About 10% of infants are infected by the age of 6 months following transmission from their mothers via the placenta, during delivery, or by breastfeeding. HCMV is a significant post-allograft pathogen and contributes to graft loss independently from graft rejection. Histopathologic examination of necropsy tissues demonstrates that the virus enters via the epithelium of the upper alimentary, respiratory, or genitourinary tracts. Hematogenous spreading is typically followed by infection of ductal epithelial cells. Infections are kept under control by the immune system. However, total HCMV clearance is rarely achieved, and the viral genome remains at selected sites in a latent state. Virological and molecular detection of HCMV, as well as serological demonstration of a specific immune response, are used for diagnosis. Treatment of HCMV infections is difficult because there are few options. The presently available drugs produced a significant clinical improvement, but suffer from poor oral bioavailability, low potency, development of resistance in clinical practice, and dose-limiting toxicities.
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