Bleach Solution Research Articles

Evaluation of Glove Performance after Decontamination.

Studies of healthcare providers doffing personal protective equipment, especially gloves, indicate that self-contamination does occur. Although generally this is not hazardous, working with particularly pathogenic organisms, such as Ebola virus and Clostridium difficile, can present a serious health risk. Decontaminating medical gloves before removal can reduce self-contamination and mitigate the spread of these types of pathogens. Also, in cases of extreme shortage, the Centers for Disease Control and Prevention (CDC) has specific recommendations for decontaminating gloves for extended use. Reuse of medical gloves is strongly discouraged by both the CDC and Food and Drug Administration. This work seeks to lay a foundation of testing to evaluate whether a decontamination method is compatible for a given glove type and material. Four potential methods of decontamination (commercial hand soap, alcohol-based hand sanitizer, commercial bleach, and quaternary ammonium solution) were tested on a variety of surgical and patient examination gloves. The method of barrier performance evaluation was ASTM D5151-19, Standard Test Method for Detection of Holes in Medical Gloves. Our results indicated that the performance of the gloves after treatment was highly dependent on the composition of the medical gloves. In general, the surgical gloves in this study performed better than the patient examination gloves, regardless of the material from which they were made. Specifically, vinyl examination gloves tended to have poorer performance. In this study, the number of gloves available to test were limited and therefore statistical significance is beyond the scope of this project.

Evaluation of a novel water-soluble decanoic acid formulation as a fruit sanitizer

Fruits irrigated with contaminated water can transmit various pathogens. High sugar content in fruits such as black cherry (BC) fruit encourages microbial proliferation. A novel water-soluble decanoic acid (WSDA) was evaluated as a fruit sanitizer and compared with other traditional fruit sanitizers such as ethanol, bleach, or dishwasher surfactants. WSDA sanitizer killed yeasts, molds and bacteria including E. coli microbes effectively as other sanitizers with (4 log cycle reduction) of microbial load. Furthermore, the bacterial sanitization mechanism i.e. bactericidal or bacteriostatic was evaluated for alcohol, bleaching and WASDA solutions. E. coli was selected as the model pathogen used for such comparison. Results indicated that the mechanism of action for the three sanitizer solutions against E. coli was bactericidal. The problem with most used fruit sanitizers is their negative influence on fruit quality in terms of physical, mechanical and taste properties. In addition, some led to toxicological and ecological concerns. Thus, studies were conducted to explore the changes in the exocarp cell structure of BC fruit upon exposure to WSDA and other sanitizers using microscopic investigation. WSDA could have a very mild or gentle effect on the BC fruit cells compared to other sanitizers. Alcohol, bleaching and dishwasher surfactant changed the cellular structures and the intercellular spaces. Sanitizers may also affect fruit swelling. WSDA showed an increase in percent weight gain but it was significantly (p < 0.05) much lower than dishwasher surfactant and bleaching solution. BC Fruit flesh firmness and hardness were investigated upon exposure to different sanitizer solutions. BC fruit treated with WSDA showed the highest firmness values. Some liquid sanitizers could affect fruit quality in terms of fruit taste. Sensory evaluation in terms of the sanitizer's smell, texture and hedonic of BC fruit after soaking in different sanitizers was carried out. All sensory parameters of BC fruit soaked with WSDA were similar with insignificant differences (p > 0.05) compared to BC fruit soaked in tap water. However, the sensory parameters were significantly different (p < 0.05) when compared with alcohol, bleach and dishwasher surfactant. This ensures that WSDA was superior to other evaluated sanitizers in terms of physical, mechanical and fruit quality.

Особенности введения в культуру in vitro барбариса илийского (Berberis iliensis M. Pop.)

The results of the introduction of Berberis iliensis M. Pop., a rare endemic plant, into in vitro culture are presented. The rare species is currently endangered. Methods of introduction into in vitro culture have been worked out, sterilizing agents and sterilization modes have been selected (5% bleach solution “Belizna”, treatment time 5 min, 10% hydrogen peroxide solution, exposure time 7 min). The WPM nutrient medium, with a pH level of 5.6–5.8, was selected as optimal for the successful development of Berberis iliensis plants in in vitro culture. Vitamins were added to the standard mineral composition of the medium. Magentas with explants were cultivated in a room without access to light at a temperature of 22–25°C and a humidity of 70% for 3–4 weeks. Further cultivation was carried out at 26°C, a light period of 16 h, and illumination of 4000–5000 lux. Aseptic cultures of B. iliensis were obtained and they had a regenerative capacity. Shoots were formed without callus, that is, direct regeneration is observed, which is the most favorable for micropropagation.

Investigating cotton dyeing using exotic wood waste sawdust

Investigating cotton dyeing using exotic wood sawdust. The study investigated the possibility of using extracts from various species of exotic wood, obtained from waste sawdust, for dyeing cotton fabrics. Material from Obeche, Iroko, Merbau, Apple tree, American walnut, Tulip tree, Cumaru and Rosewood were used for the tests. Solutions of oxalic acid, tin chloride, aluminum sulfate and ferric chloride were used as mordants, along with no-mordant tests. The color was determined in the CIE L*a*b* coordinate system. Color fastness was tested using n-hexane for dry cleaning and acidic, alkaline and hydrogen peroxide bleach solutions. The results showed a strong dependence on the type of wood, the mortar used and the washing agent and covered a wide spectrum of color intensity and fastness. The best results were obtained for Rosewood, Merbau and Apple trees, while Tulip tree and American walnut turned out to be practically useless. Among the mordants used, the most intense colors were produced by metal salts, including ferric chloride, which strongly darkened fabrics. Dry cleaning proved to be the mildest of those tested, with the least effect on color fading.

Efficacy of chemical disinfectants against SARS-CoV-2 on high-touch surface materials.

This study aimed to provide operationally relevant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surface disinfection efficacy information. Three EPA-registered disinfectants (Vital Oxide, Peroxide, and Clorox Total 360) and one antimicrobial formulation (CDC bleach) were evaluated against SARS-CoV-2 on material coupons and were tested using Spray (no touch with contact time) and Spray & Wipe (wipe immediately post-application) methods immediately and 2 h post-contamination. Efficacy was evaluated for infectious virus, with a subset tested for viral RNA (vRNA) recovery. Efficacy varied by method, disinfectant, and material. CDC bleach solution showed low efficacy against SARS-CoV-2 (log reduction<1.7), unless applied via Spray & Wipe. Additionally, mechanical wiping increased the efficacy of treatments against SARS-CoV-2. The recovery of vRNA post-disinfection suggested that vRNA may overestimate infectious virus remaining. Efficacy depends on surface material, chemical, and disinfection procedure, and suggests that mechanical wiping alone has some efficacy at removing SARS-CoV-2 from surfaces. We observed that disinfectant treatment biased the recovery of vRNA over infectious virus. These data are useful for developing effective, real-world disinfection procedures, and inform public health experts on the utility of PCR-based surveillance approaches.

Seed germination tests in Achillea genus from the Pirot County (Southeastern Serbia)

Conditions in Serbia are favorable for the successful cultivation of high-quality varieties of yarrow. The paper examines the germination of seeds of four species of the genus Achillea (A. clypeolata, A. coarctata, A. crithmifolia, A. millefolium), which grow wild in the Pirot County, in order to investigate their potential cultivation. The seeds were first placed in Krstić’s germinator for germination without prior stratification, where, apart from A. crithmifolia seeds, the seeds of the other species did not germinate. After maintaining the seeds for 24 h in a refrigerator, treatment with hot water and a 20% solution of bleach had a favorable effect on the seed germination of all four Achillea species, especially white-flowered yarrow (A. crithmifolia and A. millefolium). In particular, pouring hot water on A. crithmifolia increased the germination energy by 65% and seed germination for 43.8%, while the seed of A. millefolium, reach the germination energy increased 78% and germination 81%, so this type of seed treatment is recommended before sowing.

Determining The Best Conditioning Method For Cut-Roses

Background: Conditioning is an important step in the flower maintenance post-harvest. It helps in increased storage time and better shelf-life of the cut flowers. Conditioning provides the cut flowers with certain nutrients required for their sustainability and prevents them from getting infected from some disease-causing microbes. People generally don’t pay much importance to this step which leads to early decay and loss of their hard-earned flowers. Good conditioning can help sort out this problem and help prevent the cut-flowers from getting bad, by providing ambient conditions for the flower. Objective: The objectives of this study were to determine the best conditioning method for cut-Rose flowers through scientific experiment and getting the views on the flower behavior under different conditions based on the visual parameters. Methodology: The methodology undertaken for this work was a combination of experimental as well ob servational study. The experimental study was conducted in the housekeeping lab of IHM Pusa under the guidance of the research guide and lab attendant. The observational study was conducted through a google form questionnaire and was filled by some experts of the domain based on the visual parameters from the experiment conducted. Results: The most favorable conditions for the cut-Rose were provided by SET ‘C’ from the experiment conducted which contained a solution of sucrose, citric acid and bleach in distilled water. Also, based on the visual parameters SET ‘C’ was voted 69.04% as the best conditioner for cut-rose flower. Conclusion: Based on the results obtained from the experiment conducted and through the observations made, it was concluded that the mixture containing sucrose, bleach and citric acid proved to be helpful in conditioning of the flower in the best way, hence using the same can prevent the decay of cut flowers in a substantial manner, increase the vase-life and in-turn help attain sustainability.

Rechargeable Potent Anti‐Viral Cotton Grafted with a New Quaternized N‐Chloramine

AbstractPolymeric substrates can be endowed with antiviral properties by grafting N‐chloramine precursors to the surface. These surfaces bind oxidative chlorine from a dilute chlorine bleach solution and are similarly recharged after depletion for reuse. Previously, enhanced antibacterial efficacy of quaternized N‐chloramines compared to their neutral counterparts is reported. In this study, a new quaternized N‐chloramine N1‐(3‐methacrylamidopropyl)‐N1,N1,N10,N10‐tetramethyl‐N10‐(2,2,6,6‐tetramethylpiperidin‐4‐yl)decane‐1,10‐diaminium (MAMPIP) featuring two quaternary ammonium groups within the structure to boost the chlorination efficiency and achieve excellent antiviral efficacy against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is reported. Antiviral fabrics are prepared by free‐radical graft polymerization of MAMPIP, or copolymerization of MAMPIP with a comonomer (acrylamide or methacrylamide) onto cotton fabrics to achieve enhanced durability to re‐chlorination. The poly(MAMPIP) grafted cotton, after chlorination, is highly effective against SARS‐CoV‐2 and achieves 4.59 log reduction (99.997%) after 5 min contact. Samples grafted with the copolymer of MAMPIP and acrylamide or methacrylamide are resistant to hydrolysis during re‐chlorination and retain high active chlorine and antiviral activity after 5 cycles of re‐chlorination (&gt;3 log reduction after 10 min contact). Furthermore, the N‐chloramine coatings show excellent stability after exposure to simulated daylight conditions under an accelerated weathering tester, and storage for 200 days at 21 °C, 65% RH. The resulting quaternized N‐chloramine grafted cotton is a suitable platform for reusable antiviral textiles.

Topophysis and Growth Regulators Effects on Buds and Zygotic Embryos Regeneration of African Bush Mango Tree Cultured In vitro

Background: African bush mango tree is an important fruit plant with high nutritional, medicinal, and commercial values. However, its seedling system remained a deep understanding. This study aimed to evaluate the effect of topophysis and growth regulators on the reactivity of different types of buds and zygotic embryos of wild mango.&#x0D; Methodology: Ripe fruits from two local varieties (Wossro and Sissro) were pulped. The nuts were extracted and dried for one week under greenhouse. Zygotic embryos were excised from nuts and disinfected with the bleach solution (NaClO 10% with 8% active chloride) for 10 min following by three successive rinsing using sterilized water. The second set of nuts was cultivated for under greenhouse in the polybags containing the sand. One month later, buds from different positions (apical, axillary and cotyledonary) were excised and disinfected with NaClO 10% for 10 min follow by the immersion in a mercuric chloride 0.1% added with two drops of Tween 20 especially for axillary and cotyledonary buds for 5 min while 0.01% of mercuric chloride was used for apical buds. The explants were cultured on ¼MS and ½WPM media supplemented with BAP, KIN at different concentrations (0.2 mg/L and 3.5 mg/L respectively) and NAA (0.05 mg/L).&#x0D; Results: The best sprouting rate was obtained with the variety Wossro which showed a high bud break rate (26.47%) against (9.88%) for the variety Sissro. The topophysis significantly influenced the response of the buds in tissue culture. 24.48% of axillary buds were sprouted on ¼ MS medium + 3.5 mg/L BAP+ 0.05mg/L NAA. The in vitro germination of embryos was significantly (p≤ 0.05) influenced by the genotype of the variety. 50.76% of buds were germinated for Wossro while 18.32% were germinated for Sissro. ¼ MS + 0.2 mg/L KIN has significant influenced the plants growth and development.&#x0D; Implication: The findings will help to improve the regeneration rate and plantlets production of African bush mango tree.

First Report of Stem-end Rot Caused by Lasiodiplodia brasiliensis on Banana in USA.

US banana producers are looking for the organic banana market in the southeastern US including Florida and the coastal region of Georgia (Schupska, 2008). In December of 2020, a 6-hand bunched banana (cv. Pisang Awak, belongs to tetraploid AABB genome) with nearly 50% infection (with 15-20% disease severity, <1% of the total harvest) was received from the UGA Banana Research Plot, Tifton, GA with typical stem end rot symptoms of softened and water-soaked flesh. To identify the pathogen, the infected tissues were separated with a sterilized blade, surface disinfested with 10% bleach solution for 1 min, and subsequently washed in three changes of sterile distilled water. The sterilized tissues were aseptically placed on potato dextrose agar (PDA) medium and incubated at 25°C in the dark for 5-10 days. Two isolates of the pathogen with similar colony morphology were obtained and initially identified morphologically using a Botryosphaeriaceae taxonomic key (Phillips et al., 2013). The first growth phase for the isolates documented on PDA, gave rise to white colonies, followed by a dense, black mycelium. The mycelium was fast-spreading, immersed, branched, and septate. The shiny black pycnidia were viewed on the PDA surface after 8-10 days of incubation. Initially, the morphological features of the isolates were identified as Lasiodiplodia spp. (Phillips et al., 2013). To identify to species level, genomic DNA was extracted from two isolates (SW1 & SW2) and amplified by PCR for sequencing using ITS1/ITS4 (White et al., 1990), EF1- 688F/ EF1- 1251R (Alves et al., 2008), Bt2a/Bt2b (Glass & Donaldson, 1995) and rpb2-LasF/ rpb2-LasR (Cruywagen et al., 2017). The ITS (MZ293097 and MZ293114), EF1(OL657173 and OL657174) and rpb2 (OL704860 and OL704861) sequences showed 100% identity and Bt (OL657175 and OL657176) sequences showed 99.5% and 99.7% identity to the corresponding sequences of Lasiodiplodia brasiliensis type strain CMW35884 in GenBank (ITS: KU887094, EF1: KU886972, Bt: KU887466 and rpb2: KU696345). To further affirm the identity, a concatenated phylogenetic analysis was executed with ITS, EF1, Bt, and rpb2 sequences of both isolates and 31 reference strains using Geneious Prime 2019.2.3 Tamura-Nei Neighbor-joining method with 1,000 bootstrap replications, and the outcome was consistent with the conclusion above. To fulfill Koch's postulates, a pathogenicity test was performed with bunched bananas. Two whole bunched bananas surface sterilized with 10% bleach solutions and subsequent washing with sterilized water were cut into 3 bananas per brunch. The inoculum was prepared with 105 spores/ml. The conidial suspension was inoculated on the on-cut surface of the banana crown (300 µl per crown) using a micropipette. Sterile distilled water was applied as a control. The fruit was then packed and sealed in plastic bags and incubated at 25°C. Stem end rot symptoms were first appeared at 5 dpi and increased 7 days later. Two weeks post-inoculation, typical blackened and softened rot tissues were observed, and control fruits remained asymptomatic. To the best of our knowledge, this is the first report of Lasiodiplodia brasiliensis causing stem-end rot of bananas in the USA. This report would be valuable to the banana growers in the southeastern US by taking suitable control measures to confront this fungal disease.

Single-Step Fast Tissue Clearing of Thick Mouse Brain Tissue for Multi-Dimensional High-Resolution Imaging.

Recent advances in optical clearing techniques have dramatically improved deep tissue imaging by reducing the obscuring effects of light scattering and absorption. However, these optical clearing methods require specialized equipment or a lengthy undertaking with complex protocols that can lead to sample volume changes and distortion. In addition, the imaging of cleared tissues has limitations, such as fluorescence bleaching, harmful and foul-smelling solutions, and the difficulty of handling samples in high-viscosity refractive index (RI) matching solutions. To address the various limitations of thick tissue imaging, we developed an Aqueous high refractive Index matching and tissue Clearing solution for Imaging (termed AICI) with a one-step tissue clearing protocol that was easily made at a reasonable price in our own laboratory without any equipment. AICI can rapidly clear a 1 mm thick brain slice within 90 min with simultaneous RI matching, low viscosity, and a high refractive index (RI = 1.466), allowing the imaging of the sample without additional processing. We compared AICI with commercially available RI matching solutions, including optical clear agents (OCAs), for tissue clearing. The viscosity of AICI is closer to that of water compared with other RI matching solutions, and there was a less than 2.3% expansion in the tissue linear morphology during 24 h exposure to AICI. Moreover, AICI remained fluid over 30 days of air exposure, and the EGFP fluorescence signal was only reduced to ~65% after 10 days. AICI showed a limited clearing of brain tissue >3 mm thick. However, fine neuronal structures, such as dendritic spines and axonal boutons, could still be imaged in thick brain slices treated with AICI. Therefore, AICI is useful not only for the three-dimensional (3D) high-resolution identification of neuronal structures, but also for the examination of multiple structural imaging by neuronal distribution, projection, and gene expression in deep brain tissue. AICI is applicable beyond the imaging of fluorescent antibodies and dyes, and can clear a variety of tissue types, making it broadly useful to researchers for optical imaging applications.

Evaluation of surface disinfection methods to inactivate the beta coronavirus Murine Hepatitis Virus

The list of EPA-approved disinfectants for coronavirus features many products for use on hard, non-porous materials. There are significantly fewer products registered for use on porous materials. Further, many common, high-touch surfaces fall in between non-porous materials such as glass and porous materials such as soft fabrics. The objective of this study was to assess the efficacy of selected commercially available disinfectant products against coronaviruses on common, high-touch surfaces. Four disinfectants (Clorox Total 360, Bleach solution, Vital Oxide, and Peroxide Multi-Surface Cleaner) were evaluated against Murine Hepatitis Virus A59 (MHV) as a surrogate coronavirus for SARS-CoV-2. MHV in cell culture medium was inoculated onto four materials: stainless steel, latex-painted drywall tape, Styrene Butadiene rubber (rubber), and bus seat fabric. Immediately (T0) or 2-hr (T2) post-inoculation, disinfectants were applied by trigger-pull or electrostatic sprayer and either held for recommended contact times (Spray only) or immediately wiped (Spray and Wipe). Recovered infectious MHV was quantified by median tissue culture infectious dose assay. Bleach solution, Clorox Total 360, and Vital Oxide were all effective (>3-log10 reduction or complete kill of infectious virus) with both the Spray Only and Spray and Wipe methods on stainless steel, rubber, and painted drywall tape when used at recommended contact times at both T0 and T2 hr. Multi-Surface Cleaner unexpectedly showed limited efficacy against MHV on stainless steel within the recommended contact time; however, it showed increased (2.3 times greater efficacy) when used in the Spray and Wipe method compared to Spray Only. The only products to achieve a 3-log10 reduction on fabric were Vital Oxide and Clorox Total 360; however, the efficacy of Vital Oxide against MHV on fabric was reduced to below 3-log10 when applied by an electrostatic sprayer compared to a trigger-pull sprayer. This study highlights the importance of considering the material, product, and application method when developing a disinfection strategy for coronaviruses on high-touch surfaces.

Influence of the Type of Topical Fluoride Delivery at Various Restoration Time Points on the Micro-Shear Bond Strength of a Resin-Based Composite on Bleached Tooth Enamel.

BackgroundThis study aimed to evaluate the micro-shear bond strength (mSBS) of an adhesive applied to bleached enamel to determine the effects of fluoride supply and restoration time on the mSBS.MethodologyIn this study, we bleached 130 samples of enamel and split them into the following three groups of 40 each: group MI: McInnes bleaching solution; group MIF: McInnes bleaching solution + topical acidulated phosphate fluoride gel; group FMI: 2% fluoridated McInnes bleaching solution. Non-bleaching or fluoridation was performed on a group of 10. Subgroups were created for each group (except for the control) to be restored for seven, 14, or 21 days. The mSBS test was performed on a universal testing machine after Tygon tubes were filled with composite resin and put on enamel surfaces. Tukey’s post-hoc test (p = 0.05) and two-way analysis of variance were employed to analyze the data.ResultsThe mSBS values obtained for all groups immediately and after seven days were lower, while at 14 and 21 days were similar to the control group. According to the data, group FMI had greater mSBS levels than groups MI and MIF, both immediately and seven days later.ConclusionsWhen in-office bleaching was employed, only the fluoride McInnes solution was successful in quickly correcting the adverse effects of low mSBS.

First Report of Crown Rot of Banana Caused by Fusarium proliferatum in Georgia, U.S.A.

Crown rot is one of the most damaging disease of banana fruit characterized by rot and necrosis of crown tissues. In severe cases, the disease can spread to the pedicel and banana pulp. Crown rot can be infected by several common fungi, including Lasiodiplodia theobromae, Musicillium theobromae, Colletotrichum musae, and a complex of Fusarium spp. and lead to softening and blackening of tissues (Lassois et al., 2010; Kamel et al., 2016; Triest et al., 2016; Snowdon, 1990). In November 2020, typical crown rot of banana fruits (cv. Pisang Awak, belonging to the tetraploid AABB genome) were observed from UGA Banana Research 12 Plots, Tifton, GA, with incidence rates of 15%. Initial symptoms appeared in the infected crown of green banana fruits. As the infection progressed, the crown tissues became blackened and softened, followed by an internal development of infection affecting the peduncle and the fruit, triggered early ripening of bananas. At last, the development of necrosis on the pedicels and fruits appeared and caused the fingers to fall off. To identify the pathogen, tissue pieces (~0.25 cm2) from the infected crown and pedicles were surface-sterilized in a 10% bleach solution for 1 min, followed by 30 s in 70% EtOH. The disinfected tissues were rinsed in sterile water 3 times and cultured on potato dextrose agar (PDA) amended with 50 µg/ml streptomycin at 25°C in the dark for 5-10 days. Isolates of the pathogen were purified using the single-spore isolation method (Leslie and Summerell 2006). Colonies on PDA produced fluffy aerial mycelium and developed an intense purple pigment when viewed from the underside. A range of colony pigmentation and growth rates were observed among the isolates. The microconidia were ovoid, hyaline, or ellipse in shape. The morphological features of the isolates were identified as Fusarium proliferatum (Leslie and Summerell, 2006). To further identify the isolates, genomic DNA was extracted from a representative isolate. And the internal transcribed spacer (ITS) region, the partial elongation factor (TEF1-α) gene and the β-tubulin gene (TUB2)were amplified and sequenced using the primers ITS1/ITS4 (Yin et al. 2012), EF-1 /EF-2 (O'Donnell et al. 1998) and B-tub1 /B-tub2 (O'Donnell and Cigelnik, 1997), respectively. The amplicons were sequenced and deposited in NCBI (accessions no. MZ292989, MZ293071 for ITS: MZ346602, MZ346603 for TEF1-α and MZ346600 and MZ346601 for B-tub). The ITS, TEF1-α, and B-tub sequences of the isolates showed 100% sequence similarity with Fusarium proliferatum isolates (accessions no. MT560212, LS42312, and LT575130, respectively) using BLASTn in Genbank. For pathogenicity testing, three whole bunched bananas sterilized with 10% bleach solutions and washed by sterilized water, were cut into 5 bananas per brunch. The cut surface of the banana crown was inoculated with conidial suspension (1.0 × 107 cfu/ml) of the pathogen with pipette tips. Equal number of bananas were treated with sterilized water in the same volume as a control. All bananas were sealed in a plastic bag and incubated at 25°C. After 7 days post inoculation, all inoculated bananas showed initial crown rot symptoms while no symptoms were observed on the control bananas. The fungus was re-isolated from the symptomatic tissues of infected bananas and confirmed to be genetically identical to F. proliferatum of the original inoculated strains according to morphological characteristics and molecular identification, fulfilling Koch's postulates. To the best of our knowledge, this is the first report of F. proliferatum causing crown rot on bananas in Georgia, USA.

Microwave irradiation assisted intensive and quick delignification of lignocellulosic biomass, and confirmation by spectral, morphological and crystallinity characterization

The purpose of this work was to use a microwave-assisted technique to improve and accelerate lignin removal from rice straw biomass. Using a Box-Behnken experimental design, the effect of four critical process parameters, viz. microwave power (480–800 W), irradiation time (4–12 min), bleaching solution concentration (0.4–3.0 %), and bleaching time (1–5 h) on the delignification (%) was investigated, and the process was optimised using response surface methodology. The experimental data best fitted a quadratic model with an R2 of 0.9964. The optimized value of process parameters (in aforementioned sequence) was found to be 671 W, 8.66 min, 2.67 %, and 1 h respectively, for the best delignification of 93.51 percent.The absence of lignin peaks (1516 and 1739 cm−1) was corroborated by deconstructed morphological structure and higher crystallinity in the optimised delignified sample (53.7 %).

First Report of Botrytis cinerea Causing Leaf Spot on Strawberry in Florida.

During the 2020-2021 Florida strawberry season (October to April), strawberry (Fragaria × ananassa) plants showing leaf spots were observed on samples submitted to the Diagnostic Clinic at the University of Florida's Gulf Coast Research and Education Center. Disease incidence was up to 5% and observed on four different farms in Plant City, FL on cultivars SensationTM Florida127 and Florida Brilliance. All the samples were submitted early in the season (November) and shared the same nursery source in California. Symptoms consisted of circular or irregular lesions with purple or brown halos, eventually developing leaf blight with sporulation at the center on advanced lesions. Diseased tissues (0.5 mm2) were surface disinfested with 10% bleach solution for 90 s, rinsed twice in sterile deionized water, and plated on general isolation medium (Amiri et al. 2018). Plates were incubated at 25°C and a 12-h photoperiod. A fungus producing white mycelia with sparse sporulation of Botrytis-like spores was consistently isolated. Isolates were single-spored and grown on HA medium to induce sporulation (Leroch et al. 2013). Three isolates (20-291, 20-293, and 20-295) were selected for identification and pathogenicity assays. Resulting cultures on HA had profuse sporulation resembling gray mold. Conidia (n=50) were round to ellipsoid ranging from 9 to 14.6 μm long (Avg=10.8, SD=1.3) and 6.3 to 9.5 μm wide (Avg=7.7, Sd=0.7). No sclerotia formation was observed on GI and HA medium. Based on morphology, the pathogen was tentatively identified as Botrytis cinerea (Hong et al. 2001; Jarvis 1977). DNA was extracted from the same three isolates using the FastDNA kit (MP Biomedicals, Solon, OH), and the heat shock protein (HSP60), RNA polymerase II-binding (RPB2), and glyceraldehyde 3-phosphate dehydrogenase (G3PDH) genes were amplified (Staats et al. 2004). Sequences were deposited in GenBank (accession nos. MZ288746 - MZ288754). BLASTn searches revealed that isolates were 100% identical to B. cinerea reported causing leaf spot on strawberry in California; accession numbers MK919494 (HSP60, 996/996 bp), MK919495 (RPB2, 1131/1131 bp), and MK919496 (G3PDH, 877/877 bp). To test for pathogenicity, four one-month-old plants of 'Florida Brilliance' were used per isolate and control treatment. Spores were harvested from two-week-old cultures grown on HA medium, and the suspension adjusted to 106 spores/mL in a solution of 0.1% of Tween 20. Plants were spray inoculated until run-off and kept inside clear plastic boxes for 48 h. Control plants were sprayed with sterile deionized water. Afterward, plants were kept in a misting table in the greenhouse with a water regime of 3 s every 10 min during the day. Disease incidence was evaluated weekly, and the experiment repeated once. Two weeks after inoculation, leaf spots were observed in all inoculated plants, while controls remained healthy. Fungi morphologically identical to the original isolates were re-isolated from the diseased tissues. To our knowledge, this is the first report of B. cinerea causing leaf spot on strawberry in Florida. This disease was recently reported in California (Mansouripour and Holmes 2020), which is where the transplants originated from. Considering the disease was observed early in the Florida season, it is likely that it was introduced with transplants from the nursery. This pathogen is also the causal agent of Botrytis fruit rot, which is considered a major disease of strawberry, and a previous study has shown that populations resistant to multiple fungicides are introduced with transplants (Mertely et al. 2018, Oliveira et al. 2018). While Botrytis leaf spot is currently considered rare and of minor significance (Mansouripour and Holmes 2020), it could contribute to the spread of fungicide resistance to from nursery to strawberry fruit production fields. Efforts should be implemented to monitor its occurrence and spread considering the high variability and fungicide resistance profile of this pathogen.

Stability of Free Available Chlorine Levels in Dilute Sodium Hypochlorite Solutions over a 6-Week Period.

Animal care and use programs commonly use chlorine and chlorine-based disinfectants to help prevent facility acquired infections in animals. The Department of Comparative Medicine (DCM) at Oregon Health and Science University (OHSU) follows the Centers for Disease Control and Prevention (CDC) disinfection guidelines for preparing and storing these disinfectants. DCM prepares bottles of dilute solutions of sodium hypochlorite (that is, commercial bleach) daily. In this study, we tested whether dilute bleach solutions, as prepared following the DCM protocol, remained stable under real-world practice conditions for up to 6 wk. We tested 4 groups of spray bottles filled with 0.5% bleach solutions in these experiments. Specifically, we sprayed 2 groups of bottles daily to mimic use while 2 other groups of bottles were not sprayed. We then measured free available chlorine (FAC) using 2 methods, spectrophotometry and colorimetric strips. All 4 test groups showed stable maintenance of FAC concentration for the length of the experiment. Mean FAC loss from baseline levels was not significantly different in the group of bottles not sprayed daily (6% for group 2 at week 5 compared with 7% for Group 4 at week 6). All bottles in Groups 1 and 3 measured by colorimetric strips showed concentrations at or near 5000 mg/L at all weekly time points throughout the experiment. This study shows that 0.5% sodium hypochlorite solutions stored and used in a standard rodent housing room and sprayed daily will maintain acceptable FAC concentrations for at least 5 to 6 wk, perhaps longer. In addition, we report that colorimetric strips may be a useful and accessible quality control tool for testing freshly prepared solutions at regular intervals. We conclude that sodium hypochlorite solutions can be prepared on a weekly, biweekly, or monthly basis with no loss in disinfection effectiveness.

Thermal Infrared Enthalpimetry Method for the Determination of Hypochlorite in Bleaching Solutions

Thermal infrared enthalpimetry (TIE) was used for hypochlorite determination in commercial hypochlorite-based bleaching solutions. Experimental parameters were evaluated for the reaction with a hydrogen peroxide solution. The most relevant conditions were 5% H2O2 (m/m) solution, stirring speed of 250 rpm, dispensing rate of 0.57 mL s-1, and 10 s after reaction for the simultaneous temperature readings of four replicates. Agreement to reference method NBR 9425 ranging from 98.2 to 103.2% was achieved, with a low variation among measurements (relative standard deviation &lt; 3.5%). The number of analytical operations was reduced, and only H2O2 solution was required as a greener reagent. A low amount of residues was generated (2.4 and 152.8 mL for each replicate in TIE and official method, respectively), and the application of the green analytical procedure index (GAPI) showed the greenness of the proposed method.

Establishing an energy-saving scouring/bleaching one-step process for cotton/spandex fabric using UVA-assisted irradiation.

To reduce the energy and water consumption from a conventional textile industry, a facile and efficient UVA-assisted scouring/bleaching strategy has been customized for cotton/spandex in this research. The bleaching efficacy under UVA irradiation is explored by comparing diverse processes, i.e., Scouring only (Sc.); Conventional scouring and pad-steam bleaching (Sc/BlConv-PS); Conventional scouring and cold pad-batch bleaching (Sc/BlConv-CPB); and one or two-step scouring and UVA-assisted bleaching (Sc/BlUVA-I, Sc/BlUVA-II). The significance, interactive effect and optimisation of parameters on the whiteness index (WI) of fabric are investigated through mathematical modelling. The bleaching mechanism is analysed by a fluorescence labelling method. The dyeing and tensile properties of fabrics and the energy conservation during processing are also demonstrated. Results show that Sc/BlUVA-I achieves an equivalent scouring and bleaching effect as Sc/BlUVA-II. A superior bleaching effect of Sc/BlUVA-II over that of Sc/BlConv-PS reveals the better function of catalytic UVA than conventional steam. Under the theoretical optimal bleaching conditions (H2O2 conc. 42.96 g L−1, pH 10.24 and irradiation time 3.68 h), a calculated highest WI of 77.19 (1.48 times higher than that of untreated fabric) can be achieved based on the mathematical modelling. Through mechanism studies, hydroxyl radicals are confirmed as the main oxidative species taking part in UVA-assisted bleaching and their concentration in simulated bleaching solution dramatically increases upon the introduction of UVA. The fabric treated by Sc/BlUVA-I exhibits an acceptable strength decrease (<10%) and excellent dyeing performance with reactive dyes. The Sc/BlUVA-I strategy enables more than ca. 70% of energy conservation than the Sc/BlConv-PS process. The encouraging results manifest the practicability and promising prospects of UVA-assisted pre-treatment which contributes to enhancing the sustainability of the textile industry.

Evaluation of the effects of repeated disinfection on medical exam gloves: Part 1. Changes in physical integrity

COVID-19 has created shortages of personal protective equipment. In resource-constrained situations, limited cycles of disinfection and extended use of gloves is recommended by the U.S. Centers for Disease Control and Prevention to conserve supplies. However, these guidelines are based on limited evidence. In this study, serial cycles of hand hygiene were performed on gloved hands using an ethanol-based hand rub (six and 10 cycles), 0.1% sodium hypochlorite (bleach) solution (10 cycles), or soap and water (10 cycles) on latex and nitrile medical exam gloves from the United States and India. A modified water-leak test evaluated glove integrity after repeated applications of these disinfecting agents. When aggregated, dilute bleach demonstrated the lowest difference between treatment and control arms: −2.5 percentage points (95% CI: −5.3 to 0.3) for nitrile, 0.6 percentage points (95% CI: −2.6 to 3.8) for non-powdered latex. For U.S.-purchased gloves tested with six and 10 applications of ethanol-based hand rub, the mean difference in failure risk between treatment and control gloves was within the prespecified non-inferiority margin of five percentage points or less, though some findings were inconclusive since outside the margin. The aggregated difference in failure risk between treatment and control was 3.5 percentage points (0.6 to 6.4) for soap and water, and 2.3 percentage points (−0.5 to 5.0) and 5.0 percentage points (1.8 to 8.2) for 10 and 6 applications of ethanol-based hand rub, respectively. Most leaks occurred in the interdigital webs (35%) and on the fingers (34%). This indicates that some combinations of glove types and disinfection methods may allow for extended use. Ten applications of dilute bleach solution had the least impact on glove integrity. However, the majority of glove and exposure combinations were inconclusive. Additional testing of specific glove and disinfectant combinations may inform future strategies to guide extended use during glove shortages. Additional considerations, not evaluated here, include duration of use, disinfectant chemical permeation, and the effects of hand temperature, movement, and manipulation of instruments on glove integrity.