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1.
Clin Mol Hepatol ; 27(4): 564-574, 2021 10.
Article in English | MEDLINE | ID: covidwho-1551487

ABSTRACT

BACKGROUND/AIMS: In July 2017, the Emprint™ next-generation microwave ablation system using thermosphere technology (Covidien, Boulder, CO, USA) was approved for use in Japan. This system can produce a predictable spherical ablation zone at higher temperatures than radiofrequency ablation (RFA). The aim of the present study was to elucidate whether this new microwave thermosphere ablation (MTA) could safely improve outcome compared to RFA, which is the standard of care for small hepatocellular carcinoma (HCC). METHODS: This retrospective study analyzed 513 patients with 630 HCCs (≤3 cm) who were performed by percutaneous RFA (174 patients, 214 HCCs) or MTA (339 patients, 416 HCCs) between January 2016 and March 2020. RESULTS: Median ablation time was significantly shorter for MTA (240 seconds) than for RFA (721 seconds; P<0.001). A significant difference in 3-year local tumor progression rate was evident between the RFA group (22%) and MTA group (8%; P<0.001). Multivariable analysis revealed ablation procedure and tumor diameter as independent factors contributing to local tumor progression (MTA; P<0.001; hazard ratio, 0.565; 95% confidence interval, 0.437-0.731). In patients with primary HCC, a significant difference in overall survival was evident (RFA vs. MTA, 3-year, 77% vs. 95%, P=0.029). Ablation procedure and Child-Pugh score were independent factors contributing to survival. The total complication rate was significantly lower for MTA (8%) than for RFA (14%, P<0.05), particularly for bile duct injury (3% vs. 9%, respectively; P<0.05). CONCLUSION: Next-generation MTA for small HCC could provide safer, more curative treatment in a shorter ablation time than RFA.


Subject(s)
Carcinoma, Hepatocellular , Catheter Ablation , Liver Neoplasms , Radiofrequency Ablation , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/surgery , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/surgery , Microwaves , Radiofrequency Ablation/adverse effects , Retrospective Studies , Treatment Outcome
2.
Sensors (Basel) ; 21(21)2021 Oct 23.
Article in English | MEDLINE | ID: covidwho-1480941

ABSTRACT

This paper presents a rapid diagnostic device for the detection of the pandemic coronavirus (COVID-19) using a micro-immunosensor cavity resonator. Coronavirus has been declared an international public health crisis, so it is important to design quick diagnostic methods for the detection of infected cases, especially in rural areas, to limit the spread of the virus. Herein, a proof-of-concept is presented for a portable laboratory device for the detection of the SARS-CoV-2 virus using electromagnetic biosensors. This device is a microwave cavity resonator (MCR) composed of a sensor operating at industrial, scientific and medical (ISM) 2.45 GHz inserted in 3D housing. The changes of electrical properties of measured serum samples after passing the sensor surface are presented. The three change parameters of the sensor are resonating frequency value, amplitude and phase of the reflection coefficient |S11|. This immune-sensor offers a portable, rapid and accurate diagnostic method for the SARS-CoV-2 virus, which can enable on-site diagnosis of infection. Medical validation for the device is performed through biostatistical analysis using the ROC (Receiver Operating Characteristic) method. The predictive accuracy of the device is 63.3% and 60.6% for reflection and phase, respectively. The device has advantages of low cost, low size and weight and rapid response. It does need a trained technician to operate it since a software program operates automatically. The device can be used at ports' quarantine units, hospitals, etc.


Subject(s)
Biosensing Techniques , COVID-19 , Humans , Immunoassay , Microwaves , SARS-CoV-2
3.
Molecules ; 26(20)2021 Oct 10.
Article in English | MEDLINE | ID: covidwho-1463774

ABSTRACT

A series of novel naphthopyrano[2,3-d]pyrimidin-11(12H)-one containing isoxazole nucleus 4 was synthesized under microwave irradiation and classical conditions in moderate to excellent yields upon 1,3-dipolar cycloaddition reaction using various arylnitrile oxides under copper(I) catalyst. A one-pot, three-component reaction, N-propargylation and Dimroth rearrangement were used as the key steps for the preparation of the dipolarophiles3. The structures of the synthesized compounds were established by 1H NMR, 13C NMR and HRMS-ES means. The present study aims to also predict the theoretical assembly of the COVID-19 protease (SARS-CoV-2 Mpro) and to discover in advance whether this protein can be targeted by the compounds 4a-1 and thus be synthesized. The docking scores of these compounds were compared to those of the co-crystallized native ligand inhibitor (N3) which was used as a reference standard. The results showed that all the synthesized compounds (4a-l) gave interesting binding scores compared to those of N3 inhibitor. It was found that compounds 4a, 4e and 4i achieved greatly similar binding scores and modes of interaction than N3, indicating promising affinity towards SARS-CoV-2 Mpro. On the other hand, the derivatives 4k, 4h and 4j showed binding energy scores (-8.9, -8.5 and -8.4 kcal/mol, respectively) higher than the Mpro N3 inhibitor (-7.0 kcal/mol), revealing, in their turn, a strong interaction with the target protease, although their interactions were not entirely comparable to that of the reference N3.


Subject(s)
Antiviral Agents/chemical synthesis , Drug Design , Isoxazoles/chemistry , Pyrimidinones/chemistry , Antiviral Agents/metabolism , Antiviral Agents/therapeutic use , Binding Sites , COVID-19/drug therapy , COVID-19/virology , Click Chemistry , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/metabolism , Humans , Microwaves , Molecular Docking Simulation , Protease Inhibitors/chemistry , Protease Inhibitors/metabolism , Protease Inhibitors/therapeutic use , SARS-CoV-2/isolation & purification , Structure-Activity Relationship , Thermodynamics
4.
Clin Mol Hepatol ; 27(4): 564-574, 2021 10.
Article in English | MEDLINE | ID: covidwho-1456286

ABSTRACT

BACKGROUND/AIMS: In July 2017, the Emprint™ next-generation microwave ablation system using thermosphere technology (Covidien, Boulder, CO, USA) was approved for use in Japan. This system can produce a predictable spherical ablation zone at higher temperatures than radiofrequency ablation (RFA). The aim of the present study was to elucidate whether this new microwave thermosphere ablation (MTA) could safely improve outcome compared to RFA, which is the standard of care for small hepatocellular carcinoma (HCC). METHODS: This retrospective study analyzed 513 patients with 630 HCCs (≤3 cm) who were performed by percutaneous RFA (174 patients, 214 HCCs) or MTA (339 patients, 416 HCCs) between January 2016 and March 2020. RESULTS: Median ablation time was significantly shorter for MTA (240 seconds) than for RFA (721 seconds; P<0.001). A significant difference in 3-year local tumor progression rate was evident between the RFA group (22%) and MTA group (8%; P<0.001). Multivariable analysis revealed ablation procedure and tumor diameter as independent factors contributing to local tumor progression (MTA; P<0.001; hazard ratio, 0.565; 95% confidence interval, 0.437-0.731). In patients with primary HCC, a significant difference in overall survival was evident (RFA vs. MTA, 3-year, 77% vs. 95%, P=0.029). Ablation procedure and Child-Pugh score were independent factors contributing to survival. The total complication rate was significantly lower for MTA (8%) than for RFA (14%, P<0.05), particularly for bile duct injury (3% vs. 9%, respectively; P<0.05). CONCLUSION: Next-generation MTA for small HCC could provide safer, more curative treatment in a shorter ablation time than RFA.


Subject(s)
Carcinoma, Hepatocellular , Catheter Ablation , Liver Neoplasms , Radiofrequency Ablation , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/surgery , Humans , Liver Neoplasms/diagnosis , Liver Neoplasms/surgery , Microwaves , Radiofrequency Ablation/adverse effects , Retrospective Studies , Treatment Outcome
5.
J Vasc Interv Radiol ; 32(1): 33-38, 2021 01.
Article in English | MEDLINE | ID: covidwho-1454337

ABSTRACT

PURPOSE: To determine effect of body mass index (BMI) on safety and cancer-related outcomes of thermal ablation for renal cell carcinoma (RRC). MATERIALS AND METHODS: This retrospective study evaluated 427 patients (287 men and 140 women; mean [SD] age, 72 [12] y) who were treated with thermal ablation for RCC between October 2006 and December 2017. Patients were stratified by BMI into 3 categories: normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥ 30 kg/m2). Of 427 patients, 71 (16%) were normal weight, 157 (37%) were overweight, and 199 (47%) were obese. Complication rates, local recurrence, and residual disease were compared in the 3 cohorts. RESULTS: No differences in technical success between normal-weight, overweight, and obese patients were identified (P = .72). Primary technique efficacy rates for normal-weight, overweight, and obese patients were 91%, 94%, and 93% (P = .71). There was no significant difference in RCC specific-free survival, disease-free survival, and metastasis-free survival between obese, overweight, and normal-weight groups (P = .72, P = .43, P = .99). Complication rates between the 3 cohorts were similar (normal weight 4%, overweight 2%, obese 3%; P = .71). CONCLUSIONS: CT-guided renal ablation is safe, feasible, and effective regardless of BMI.


Subject(s)
Body Mass Index , Carcinoma, Renal Cell/surgery , Cryosurgery , Kidney Neoplasms/surgery , Microwaves/therapeutic use , Obesity/diagnosis , Radiofrequency Ablation , Aged , Aged, 80 and over , Carcinoma, Renal Cell/mortality , Carcinoma, Renal Cell/secondary , Cryosurgery/adverse effects , Cryosurgery/mortality , Disease Progression , Disease-Free Survival , Female , Humans , Kidney Neoplasms/mortality , Kidney Neoplasms/pathology , Male , Microwaves/adverse effects , Middle Aged , Neoplasm Recurrence, Local , Obesity/mortality , Patient Safety , Radiofrequency Ablation/adverse effects , Radiofrequency Ablation/mortality , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome
6.
Photochem Photobiol Sci ; 20(7): 955-965, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1384775

ABSTRACT

The pandemic created by SARS-CoV-2 has caused a shortage in the supplies of N95 filtering facepiece respirators (FFRs), disposable respirators with at least 95% efficiency to remove non-oily airborne particles, due to increasing cases all over the world. The current article reviewed various possible decontamination methods for FFR reuse including ultraviolet germicidal irradiation (UVGI), hydrogen peroxide vapor (HPV), microwave-generated steam (MGS), hydrogen peroxide gas plasma (HPGP), and 70% or higher ethanol solution. HPV decontamination was effective against bacterial spores (6 log10 reduction of Geobacillus stearothermophilus spores) on FFRs and viruses (> 4 log10 reduction of various types of viruses) on inanimate surfaces, and no degradation of respirator materials and fit has been reported. 70% or higher ethanol decontamination showed high efficacy in inactivation of coronaviruses on inanimate surfaces (> 3.9 log10 reduction) but it was lower on FFRs which filtration efficiency was also decreased. UVGI method had good biocidal efficacy on FFRs (> 3 log10 reduction of H1N1 virus) combined with inexpensive, readily available equipment; however, it was more time-consuming to ensure sufficient reduction in SARS-CoV-2. MGS treatment also provided good viral decontamination on FFRs (> 4 log10 reduction of H1N1 virus) along with less time-intensive process and readily available equipment while inconsistent disinfection on the treated surfaces and deterioration of nose cushion of FFRs were observed. HPGP was a good virucidal system (> 6 log10 reduction of Vesicular stomatitis virus) but filtration efficiency after decontamination was inconsistent. Overall, HPV appeared to be one of the most promising methods based on the high biocidal efficacy on FFRs, preservation of respirator performance after multiple cycles, and no residual chemical toxicity. Nonetheless, equipment cost and time of the HPV process and a suitable operating room need to be considered.


Subject(s)
COVID-19 , Decontamination/methods , N95 Respirators/microbiology , N95 Respirators/virology , Bacteria/drug effects , Bacteria/isolation & purification , Bacteria/radiation effects , COVID-19/epidemiology , Disinfection/methods , Ethanol/pharmacology , Humans , Hydrogen Peroxide/pharmacology , Microwaves , Ultraviolet Rays , Viruses/drug effects , Viruses/isolation & purification , Viruses/radiation effects
7.
Environ Sci Technol ; 55(9): 6239-6247, 2021 05 04.
Article in English | MEDLINE | ID: covidwho-1169372

ABSTRACT

White wastes (unseparated plastics, face masks, textiles, etc.) pose a serious challenge to sustainable human development and the ecosystem and have recently been exacerbated due to the surge in plastic usage and medical wastes from COVID-19. Current recycling methods such as chemical recycling, mechanical recycling, and incineration require either pre-sorting and washing or releasing CO2. In this work, a carbon foam microwave plasma process is developed, utilizing plasma discharge to generate surface temperatures exceeding ∼3000 K in a N2 atmosphere, to convert unsorted white wastes into gases (H2, CO, C2H4, C3H6, CH4, etc.) and small amounts of inorganic minerals and solid carbon, which can be buried as artificial "coal". This process is self-perpetuating, as the new solid carbon asperities grafted onto the foam's surface actually increase the plasma discharge efficiency over time. This process has been characterized by in situ optical probes and infrared sensors and optimized to handle most of the forms of white waste without the need for pre-sorting or washing. Thermal measurement and modeling show that in a flowing reactor, the device can achieve locally extremely high temperatures, but the container wall will still be cold and can be made with cheap materials, and thus, a miniaturized waste incinerator is possible that also takes advantage of intermittent renewable electricity.


Subject(s)
COVID-19 , Refuse Disposal , Carbon , Ecosystem , Humans , Hydrocarbons , Microwaves , SARS-CoV-2
9.
PLoS One ; 15(11): e0242474, 2020.
Article in English | MEDLINE | ID: covidwho-937231

ABSTRACT

BACKGROUND: There is global shortage of Personal Protective Equipment due to COVID-19 pandemic. N95 Filtering Facepiece Respirators (N95-FFRs) provide respiratory protection against respiratory pathogens including SARS-CoV-2. There is scant literature on reprocessing methods which can enable reuse of N95-FFRs. AIM: We conducted this study to evaluate research done, prior to COVID-19 pandemic, on various decontamination methods for reprocessing of N95-FFRs. METHODS: We searched 5 electronic databases (Pubmed, Google Scholar, Crossref, Ovid, ScienceDirect) and 1 Grey literature database (OpenGrey). We included original studies, published prior to year 2020, which had evaluated any decontamination method on FFRs. Studies had evaluated a reprocessing method against parameters namely physical changes, user acceptability, respirator fit, filter efficiency, microbicidal efficacy and presence of chemical residues post-reprocessing. FINDINGS AND CONCLUSIONS: Overall, we found 7887 records amongst which 17 original research articles were finally included for qualitative analysis. Overall, 21 different types of decontamination or reprocessing methods for N95-FFRs were evaluated. Most commonly evaluated method for reprocessing of FFRs was Ultraviolet (Type-C) irradiation (UVGI) which was evaluated in 13/17 (76%) studies. We found published literature was scant on this topic despite warning signs of pandemic of a respiratory illness over the years. Promising technologies requiring expeditious evaluation are UVGI, Microwave generated steam (MGS) and based on Hydrogen peroxide vapor. Global presence of technologies, which have been given Emergency use authorisation for N95-FFR reprocessing, is extremely limited. Reprocessing of N95-FFRs by MGS should be considered for emergency implementation in resource limited settings to tackle shortage of N95-FFRs. SYSTEMATIC REVIEW IDENTIFIER: PROSPERO, PROSPERO ID: CRD42020189684, (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020189684).


Subject(s)
Decontamination/methods , Disinfection/methods , Equipment Reuse , Masks , Respiratory Protective Devices , Betacoronavirus , COVID-19 , Coronavirus Infections/prevention & control , Equipment Safety , Humans , Hydrogen Peroxide , Microwaves , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , SARS-CoV-2 , Steam , Ultraviolet Rays
10.
ACS Nano ; 14(10): 13161-13171, 2020 10 27.
Article in English | MEDLINE | ID: covidwho-798108

ABSTRACT

The regeneration of filtering facepiece respirators (FFRs) is of critical importance because of the severe shortage of FFRs during large-scale outbreaks of respiratory epidemics, such as COVID-19. Comprehensive experiments regarding FFR regeneration were performed in this study with model bacteria to illustrate the decontamination performance of the regeneration processes. The results showed that it is dangerous to use a contaminated FFR without any microbe inactivation treatment because the bacteria can live for more than 8 h. The filtration efficiency and surface electrostatic potential of 75% ethanol-treated FFRs were significantly reduced, and a most penetrating particle size of 200 nm was observed. Steam and microwave irradiation (MWI) showed promising decontamination performances, achieving 100% inactivation in 90 and 30 min, respectively. The filtration efficiencies of steam-treated FFRs for 50 and 100 nm particles decreased from 98.86% and 99.51% to 97.58% and 98.79%, respectively. Ultraviolet irradiation (UVI) effectively inactivated the surface bacteria with a short treatment of 5 min and did not affect the filtration performance. However, the UV dose reaching different layers of the FFP2 mask sample gradually decreased from the outermost layer to the innermost layer, while the model bacteria on the second and third layers could not be killed completely. UVI+MWI and steam were recommended to effectively decontaminate the used respirators and still maintain the respirators' filtration efficiency. The present work provides a comprehensive evaluation for FFR regeneration in terms of the filtration efficiencies for 50-500 nm particles, the electrostatic properties, mechanical properties, and decontamination effects.


Subject(s)
Bacteria/radiation effects , Disinfection/methods , Masks/microbiology , Respiratory Protective Devices/microbiology , Bacteria/drug effects , Bacteria/pathogenicity , Disinfection/standards , Ethanol/toxicity , Filtration , Humans , Masks/standards , Microwaves , Respiratory Protective Devices/standards , Steam , Textiles/microbiology , Textiles/standards , Ultraviolet Rays
11.
J Hosp Infect ; 106(1): 10-19, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-635297

ABSTRACT

BACKGROUND: In the wake of the SARS-CoV-2 pandemic and unprecedented global demand, clinicians are struggling to source adequate access to personal protective equipment. Respirators can be in short supply, though are necessary to protect workers from SARS-CoV-2 exposure. Rapid decontamination and reuse of respirators may provide relief for the strained procurement situation. METHOD: In this study, we investigated the suitability of 70°C dry heat and microwave-generated steam (MGS) for reprocessing of FFP2/N95-type respirators, and Type-II surgical face masks. Staphylococcus aureus was used as a surrogate as it is less susceptible than enveloped viruses to chemical and physical processes. RESULTS: We observed >4 log10 reductions in the viability of dry S. aureus treated by dry heat for 90 min at 70°C and >6 log10 reductions by MGS for 90 s. After 3 reprocessing cycles, neither process was found to negatively impact the bacterial or NaCl filtration efficiency of the respirators that were tested. However, MGS was incompatible with Type-II surgical masks tested, as we confirmed that bacterial filtration capacity was completely lost following reprocessing. MGS was observed to be incompatible with some respirator types due to arcing observed around some types of metal nose clips and by loss of adhesion of clips to the mask. CONCLUSION: Considering the advantages and disadvantages of each approach, we propose a reprocessing personal protective equipment/face mask workflow for use in medical areas.


Subject(s)
Coronavirus Infections/prevention & control , Decontamination/methods , Equipment Reuse/standards , Hot Temperature , Masks/virology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Respiratory Protective Devices/virology , Steam , Betacoronavirus , COVID-19 , Guidelines as Topic , Humans , Microwaves , SARS-CoV-2
12.
mBio ; 11(3)2020 06 25.
Article in English | MEDLINE | ID: covidwho-616491

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has caused a severe, international shortage of N95 respirators, which are essential to protect health care providers from infection. Given the contemporary limitations of the supply chain, it is imperative to identify effective means of decontaminating, reusing, and thereby conserving N95 respirator stockpiles. To be effective, decontamination must result in sterilization of the N95 respirator without impairment of respirator filtration or user fit. Although numerous methods of N95 decontamination exist, none are universally accessible. In this work, we describe a microwave-generated steam decontamination protocol for N95 respirators for use in health care systems of all sizes, geographies, and means. Using widely available glass containers, mesh from commercial produce bags, a rubber band, and a 1,100-W commercially available microwave, we constructed an effective, standardized, and reproducible means of decontaminating N95 respirators. Employing this methodology against MS2 phage, a highly conservative surrogate for SARS-CoV-2 contamination, we report an average 6-log10 plaque-forming unit (PFU) (99.9999%) and a minimum 5-log10 PFU (99.999%) reduction after a single 3-min microwave treatment. Notably, quantified respirator fit and function were preserved, even after 20 sequential cycles of microwave steam decontamination. This method provides a valuable means of effective decontamination and reuse of N95 respirators by frontline providers facing urgent need.IMPORTANCE Due to the rapid spread of coronavirus disease 2019 (COVID-19), there is an increasing shortage of protective gear necessary to keep health care providers safe from infection. As of 9 April 2020, the CDC reported 9,282 cumulative cases of COVID-19 among U.S. health care workers (CDC COVID-19 Response Team, MMWR Morb Mortal Wkly Rep 69:477-481, 2020, https://doi.org/10.15585/mmwr.mm6915e6). N95 respirators are recommended by the CDC as the ideal method of protection from COVID-19. Although N95 respirators are traditionally single use, the shortages have necessitated the need for reuse. Effective methods of N95 decontamination that do not affect the fit or filtration ability of N95 respirators are essential. Numerous methods of N95 decontamination exist; however, none are universally accessible. In this study, we describe an effective, standardized, and reproducible means of decontaminating N95 respirators using widely available materials. The N95 decontamination method described in this work will provide a valuable resource for hospitals, health care centers, and outpatient practices that are experiencing increasing shortages of N95 respirators due to the COVID-19 pandemic.


Subject(s)
Betacoronavirus/radiation effects , Coronavirus Infections/prevention & control , Decontamination/instrumentation , Decontamination/methods , Masks , Steam , Betacoronavirus/physiology , COVID-19 , Coronavirus Infections/transmission , Coronavirus Infections/virology , Decontamination/standards , Disease Transmission, Infectious/prevention & control , Disinfection/instrumentation , Disinfection/methods , Equipment Reuse/standards , Filtration , Humans , Microwaves , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pneumonia, Viral/transmission , Reproducibility of Results , SARS-CoV-2 , Sterilization , United States
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