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Objective:The coronavirus disease 2019 (COVID-19) pandemic has resulted in shortages of personal protective equipment (PPE), underscoring the urgent need for simple, efficient, and inexpensive methods to decontaminate masks and respirators exposed to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). We hypothesized that methylene blue (MB) photochemical treatment, which has various clinical applications, could decontaminate PPE contaminated with coronavirus.Design:The 2 arms of the study included (1) PPE inoculation with coronaviruses followed by MB with light (MBL) decontamination treatment and (2) PPE treatment with MBL for 5 cycles of decontamination to determine maintenance of PPE performance.Methods:MBL treatment was used to inactivate coronaviruses on 3 N95 filtering facepiece respirator (FFR) and 2 medical mask models. We inoculated FFR and medical mask materials with 3 coronaviruses, including SARS-CoV-2, and we treated them with 10 µM MB and exposed them to 50,000 lux of white light or 12,500 lux of red light for 30 minutes. In parallel, integrity was assessed after 5 cycles of decontamination using multiple US and international test methods, and the process was compared with the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method.Results:Overall, MBL robustly and consistently inactivated all 3 coronaviruses with 99.8% to >99.9% virus inactivation across all FFRs and medical masks tested. FFR and medical mask integrity was maintained after 5 cycles of MBL treatment, whereas 1 FFR model failed after 5 cycles of VHP+O3.Conclusions:MBL treatment decontaminated respirators and masks by inactivating 3 tested coronaviruses without compromising integrity through 5 cycles of decontamination. MBL decontamination is effective, is low cost, and does not require specialized equipment, making it applicable in low- to high-resource settings.

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has resulted in severe shortages of personal protective equipment (PPE) necessary to protect front-line healthcare personnel. These shortages underscore the urgent need for simple, efficient, and inexpensive methods to decontaminate SARS-CoV-2-exposed PPE enabling safe reuse of masks and respirators. Efficient decontamination must be available not only in low-resourced settings, but also in well-resourced settings affected by PPE shortages. Methylene blue (MB) photochemical treatment, hitherto with many clinical applications including those used to inactivate virus in plasma, presents a novel approach for widely applicable PPE decontamination. Dry heat (DH) treatment is another potential low-cost decontamination method.MethodsMB and light (MBL) and DH treatments were used to inactivate coronavirus on respirator and mask material. We tested three N95 filtering facepiece respirators (FFRs), two medical masks (MMs), and one cloth community mask (CM). FFR/MM/CM materials were inoculated with SARS-CoV-2 (a Betacoronavirus), murine hepatitis virus (MHV) (a Betacoronavirus), or porcine respiratory coronavirus (PRCV) (an Alphacoronavirus), and treated with 10 µM MB followed by 50,000 lux of broad-spectrum light or 12,500 lux of red light for 30 minutes, or with 75°C DH for 60 minutes. In parallel, we tested respirator and mask integrity using several standard methods and compared to the FDA-authorized vaporized hydrogen peroxide plus ozone (VHP+O3) decontamination method. Intact FFRs/MMs/CM were subjected to five cycles of decontamination (5CD) to assess integrity using International Standardization Organization (ISO), American Society for Testing and Materials (ASTM) International, National Institute for Occupational Safety and Health (NIOSH), and Occupational Safety and Health Administration (OSHA) test methods.FindingsOverall, MBL robustly and consistently inactivated all three coronaviruses with at least a 4-log reduction. DH yielded similar results, with the exception of MHV, which was only reduced by 2-log after treatment. FFR/MM integrity was maintained for 5 cycles of MBL or DH treatment, whereas one FFR failed after 5 cycles of VHP+O3. Baseline performance for the CM was variable, but reduction of integrity was minimal.InterpretationMethylene blue with light and DH treatment decontaminated masks and respirators by inactivating three tested coronaviruses without compromising integrity through 5CD. MBL decontamination of masks is effective, low-cost and does not require specialized equipment, making it applicable in all-resource settings. These attractive features support the utilization and continued development of this novel PPE decontamination method.

The green mantle of the earth! This metaphor is a poetic image that borrows from the vocabulary of weaving and epitomizes the Renaissance interest in "fashioning green worlds" in art and poetry. Here it serves as a motto for a cultural poetics that made representing living nature increasingly popular across Italy in the Early Modern period. The explosion of landscape art in this era is often associated with the rise of interest in the literary pastoral, narrowly defined, but this volume expands that understanding to show Green’s broad appeal as it intrigued audiences ranging from the ecclesiastic to the medical and scientific to the humanistic and courtly. The essays gathered here explore the expanding technologies and varied cultural dimensions of verzure and verdancy in the Italian Renaissance, and thus the role of visual art in shaping the poetics and expression of greenery in the arts of the 16th-century and beyond.

I have a copy of Source once owned by Leo Steinberg. His annotations show that he avidly read the journal, commenting in the margins on ideas raised and, remarkably, grading each essay (including my own). What such an eminent mind as Steinberg’s looked forward to, as we all do with each issue of Source, is the unique way the journal feeds scholarship. Because of its devotion to brevity, Source allows readers rapidly to come to terms with new research and methodologies. Additionally, the required shortness of the articles moves new ideas quickly into the field. For decades, Laurie Schneider Adams was the guiding spirit of Source, shaping it into the eloquent and exciting journal it became, one in which an impressive array of scholars share their work, one that the lights of our field look forward to reading. She will be greatly missed.

Twitch contractions of the ankle dorsiflexors were evoked before and after 7 s of tetanic stimulation at 100 Hz in young women and men. Torque decreased more in men (18%) than in women (12%) during the tetanus. There was no gender difference in twitch peak torque potentiation over the 5-min post-tetanus. Potentiation was 42% (women) and 45% (men) at 5 s post-tetanus, and still present at 5 min (women 24%, men 25%). The immediate (5 s) shortening of twitch rise time was similar in women (14%) and men (13%), but during the 5-min men's rise time came to exceed whereas women's only approached pretetanus values (e.g., +9% vs. -1% at 5 min). The immediate decrease in half-relaxation time was also similar in women (24%) and men (22%); however, women's but not men's values remained less than pretetanus values for most of the 5-min period. Twitch rate of torque development increased similarly (75%) in women and men at 5 s, with no gender difference over 5 min. In contrast, rate of torque relaxation increased significantly only in men. Rate of torque development normalized to peak torque was similar in women and men pretetanus and increased similarly 5 s post-tetanus, but women had greater values through most of the 5-min post-tetanus. Normalized rate of torque relaxation was similar in women and men and not affected by tetanus. In the dorsiflexor muscles, young women and men show a similar amount and pattern of twitch force potentiation, but there are gender differences in time-related twitch contractile properties in the first 5 min after tetanus.Key words: contraction, muscle, twitch.

O’Leary, Deborah D., Karen Hope, and Digby G. Sale.Posttetanic potentiation of human dorsiflexors. J. Appl. Physiol. 83(6): 2131–2138, 1997.—Twitch contractions of the ankle dorsiflexors were evoked before and after applied 7-s tetanic stimulation at 100 Hz in 20 young adults. Torque decreased 15% during the tetanus. At 5 s after tetanus, twitch peak torque had potentiated 45%. Potentiation declined to 28% after 1 min, rose slightly to 33% at 2 min, and declined slowly with potentiation still 25% after 5 min. There was large intersubject variation in the amount of potentiation (5–140%) and its persistence (5 to ≥20 min). The muscle compound action potential (M wave) did not change significantly (from pretetanic value) at 5 s after tetanus but increased sharply (26%) at 2 min and then subsided. Twitch half relaxation time (23%) decreased significantly more than twitch rise time (13%) 5 s after tetanus and recovered more slowly. Twitch rates of torque development (75%) and relaxation (71%) increased similarly 5 s after tetanus and were still elevated (∼25%) at 5 min. The extent of twitch torque potentiation was significantly inversely correlated with pretetanic twitch rise time ( r = −0.69), half relaxation time ( r = −0.61), and twitch-to-tetanus ratio ( r = −0.66). The data indicate that posttetanic potentiation has a greater effect on twitch half relaxation time than on time to peak torque and is more prominent in muscles with a short twitch time course and small twitch-to-tetanus ratio.

Nowadays, plant is being used as a biofuel, a probable source for a pesticide and it is valued for its pharmacological effects. Hence, the researchers engaged in the scientific approach to provide explanation to these claims. The study focused on the phytochemical screening of the ethanolic extract of radish bulbs (Raphanus sativus). It further dealt on the isolation and determination of the molecular masses to provide probable structures and associated molecular properties for its constituents.Alkaloids, flavonoids, saponins and tannins were analyzed. Further, this effort involved analysis through Thin Layer Chromatography (TLC) using the mobile phase of Toluene: Chloroform (9:11) and Gas Chromatography- Mass Spectrometry (GC-MS) to analyze the first spot (Retention Factor= 0.667).Phytochemical analysis showed no tannins. Using TLC, it revealed two spots having Rf values of 0.667 and 0.507, respectively. Using GC-MS method, 24 different molecules were isolated and analyzed of which only 23 were given probable structures. The 23 molecules constituted 11 long-chain alkanes, 4 long-chain alkyl esters, 2 aromatic ketones, a benzyl halide, an aryl ether, a quinone, an aromatic aldehyde, a long chain aromatic alkane, and a long-chain alkyl nitrile. With this finding, the bulb extract may be a good source of potential biofuel (mono-alkyl ester), UV A, B and C blockers in the form of diphenyl-ketone, oviposition attractants (long-chain alkanes) and also a source of bioactive molecules such as estragole which shows antispasmodic effect, methyl palmitate with immunosuppressive effect in semi-allografts and hepatoprotective activity in rats, and an analogue of the antidepressant alfetamine.

Objective:Multipatient use and prolonged use of prefilled disposable oxygen humidifier bottles (Aquapak 301, Respiratory Care, Inc., Arlington Heights, IL) were evaluated by performing microbiologic monitoring and a cost analysis on bottles used for varying numbers of patients and lengths of time.Methods:Humidifiers were hung for a maximum of one month. Monitoring was conducted in 6 different nursing areas. Quantitative cultures were done for aerobes and Legionella. Reusable humidifier bottles also were monitored.Results:Cultures were obtained from 1,311 disposable and 60 reusable humidifiers. No significant bacterial contamination was detected in the prefilled disposable oxygen humidifier units. Ten percent of the reusable bottles were contaminated by organisms associated with skin flora.Conclusions:Multipatient use and increased duration of use of disposable humidifiers result in cost savings without increasing patient risk. Restricted multipatient use of prefilled disposable oxygen humidifier bottles for a period of one month is a safe and cost-efficient practice.