Stabilizing Cu2+ Ions by Solid Solutions to Promote CO2 Electroreduction to Methane.

Copper is the only metal catalyst that can perform the electrocatalytic CO2 reduction reaction (CRR) to produce hydrocarbons and oxygenates. Its surface oxidation state determines the reaction pathway to various products. However, under the cathodic potential of CRR conditions, the chemical composition of most Cu-based catalysts inevitably undergoes electroreduction from Cu2+ to Cu0 or Cu1+ species, which is generally coupled with phase reconstruction and the formation of new active sites. Since the initial Cu2+ active sites are hard to retain, there have been few studies about Cu2+ catalysts for CRR. Herein we propose a solid-solution strategy to stabilize Cu2+ ions by incorporating them into a CeO2 matrix, which works as a self-sacrificing ingredient to protect Cu2+ active species. In situ spectroscopic characterization and density functional theory calculations reveal that compared with the conventionally derived Cu catalysts with Cu0 or Cu1+ active sites, the Cu2+ species in the solid solution (Cu-Ce-Ox) can significantly strengthen adsorption of the *CO intermediate, facilitating its further hydrogenation to produce CH4 instead of dimerization to give C2 products. As a result, different from most of the other Cu-based catalysts, Cu-Ce-Ox delivered a high Faradaic efficiency of 67.8% for CH4 and a low value of 3.6% for C2H4.

Transcriptome profiling of the diaphragm in a controlled mechanical ventilation model reveals key genes involved in ventilator-induced diaphragmatic dysfunction.

BACKGROUND: Ventilator-induced diaphragmatic dysfunction (VIDD) is associated with weaning difficulties, intensive care unit hospitalization (ICU), infant mortality, and poor long-term clinical outcomes. The expression patterns of long noncoding RNAs (lncRNAs) and mRNAs in the diaphragm in a rat controlled mechanical ventilation (CMV) model, however, remain to be investigated. RESULTS: The diaphragms of five male Wistar rats in a CMV group and five control Wistar rats were used to explore lncRNA and mRNA expression profiles by RNA-sequencing (RNA-seq). Muscle force measurements and immunofluorescence (IF) staining were used to verify the successful establishment of the CMV model. A total of 906 differentially expressed (DE) lncRNAs and 2,139 DE mRNAs were found in the CMV group. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to determine the biological functions or pathways of these DE mRNAs. Our results revealed that these DE mRNAs were related mainly related to complement and coagulation cascades, the PPAR signaling pathway, cholesterol metabolism, cytokine-cytokine receptor interaction, and the AMPK signaling pathway. Some DE lncRNAs and DE mRNAs determined by RNA-seq were validated by quantitative real-time polymerase chain reaction (qRT-PCR), which exhibited trends similar to those observed by RNA-sEq. Co-expression network analysis indicated that three selected muscle atrophy-related mRNAs (Myog, Trim63, and Fbxo32) were coexpressed with relatively newly discovered DE lncRNAs. CONCLUSIONS: This study provides a novel perspective on the molecular mechanism of DE lncRNAs and mRNAs in a CMV model, and indicates that the inflammatory signaling pathway and lipid metabolism may play important roles in the pathophysiological mechanism and progression of VIDD.

Altered expression of microRNAs in the rat diaphragm in a model of ventilator-induced diaphragm dysfunction after controlled mechanical ventilation.

BACKGROUND: Ventilator-induced diaphragm dysfunction (VIDD) is a common complication of life support by mechanical ventilation observed in critical patients in clinical practice and may predispose patients to severe complications such as ventilator-associated pneumonia or ventilator discontinuation failure. To date, the alterations in microRNA (miRNA) expression in the rat diaphragm in a VIDD model have not been elucidated. This study was designed to identify these alterations in expression. RESULTS: Adult male Wistar rats received conventional controlled mechanical ventilation (CMV) or breathed spontaneously for 12 h. Then, their diaphragm tissues were collected for RNA extraction. The miRNA expression alterations in diaphragm tissue were investigated by high-throughput microRNA-sequencing (miRNA-seq). For targeted mRNA functional analysis, gene ontology (GO) analyses and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were subsequently conducted. qRT-PCR validation and luciferase reporter assays were performed. We successfully constructed a model of ventilator-induced diaphragm dysfunction and identified 38 significantly differentially expressed (DE) miRNAs, among which 22 miRNAs were upregulated and 16 were downregulated. GO analyses identified functional genes, and KEGG pathway analyses revealed the signaling pathways that were most highly correlated, which were the MAPK pathway, FoxO pathway and Autophagy-animal. Luciferase reporter assays showed that STAT3 was a direct target of both miR-92a-1-5p and miR-874-3p and that Trim63 was a direct target of miR-3571. CONCLUSIONS: The current research supplied novel perspectives on miRNAs in the diaphragm, which may not only be implicated in diaphragm dysfunction pathogenesis but could also be considered as therapeutic targets in diaphragm dysfunction.

Molecular Scalpel to Chemically Cleave Metal-Organic Frameworks for Induced Phase Transition.

A bottom-up chemical synthesis of metal-organic frameworks (MOFs) permits significant structural diversity because of various combinations of metal centers and different organic linkers. However, fabrication generally complies with the classic hard and soft acids and bases (HSAB) theory. This restricts direct synthesis of desired MOFs with converse Lewis type of metal ions and ligands. Here we present a top-down strategy to break this limitation via the structural cleavage of MOFs to trigger a phase transition using a novel "molecular scalpel". A conventional CuBDC MOF (BDC = 1,4-benzenedicarboxylate) prepared from a hard acid (Cu2+) metal and a hard base ligand was chemically cleaved by l-ascorbic acid acting as chemical scalpel to fabricate a new Cu2BDC structure composed of a soft acid (Cu1+) and a hard base (BDC). Controlled phase transition was achieved by a series of redox steps to regulate the chemical state and coordination number of Cu ions, resulting in a significant change in chemical composition and catalytic activity. Mechanistic insights into structural cleavage and rearrangement are elaborated in detail. We show this novel strategy can be extended to general Cu-based MOFs and supramolecules for nanoscopic casting of unique architectures from existing ones.

Wearing a N95 mask increases rescuer's fatigue and decreases chest compression quality in simulated cardiopulmonary resuscitation.

OBJECTIVES: N95 mask is essential for healthcare workers dealing with the coronavirus disease 2019 (COVID-19). However, N95 mask causes discomfort breathing with marked reduction in air exchange. This study was designed to investigate whether the use of N95 mask affects rescuer's fatigue and chest compression quality during cardiopulmonary resuscitation (CPR). METHODS: After a brief review of CPR, each participant performed a 2-minute continuous chest compression on a manikin wearing N95 (N95 group, n = 40) or surgical mask (SM group, n = 40). Compression rate and depth, the proportions of correct compression rate, depth, complete chest recoil and hand position were documented. Participants' fatigue was assessed using Borg score. RESULTS: Significantly lower mean chest compression rate and depth were both achieved in the N95 group than in the SM group (p < 0.05, respectively). In addition, the proportion of correct compression rate (61 ± 19 vs. 75 ± 195, p = 0.0067), depth (67 ± 16 vs. 90 ± 14, p < 0.0001) and complete recoil (91 ± 16 vs. 98 ± 5%, p = 0.0248) were significantly decreased in the N95 group as compared to the SM group. At the end of compression, the Borg score in the N95 group was significantly higher than that in the SM group (p = 0.027). CONCLUSION: Wearing a N95 mask increases rescuer's fatigue and decreases chest compression quality during CPR. Therefore, the exchange of rescuers during CPR should be more frequent than that recommended in current guidelines when N95 masks are applied.

Lung-protective ventilation worsens ventilator-induced diaphragm atrophy and weakness.

BACKGROUND: Lung-protective ventilation (LPV) has been found to minimize the risk of ventilator-induced lung injury (VILI). However, whether LPV is able to diminish ventilator-induced diaphragm dysfunction (VIDD) remains unknown. This study was designed to test the hypothesis that LPV protects the diaphragm against VIDD. METHODS: Adult male Wistar rats received either conventional mechanical (tidal volume [VT]: 10 ml/kg, positive end-expiratory pressure [PEEP]: 2 cm H2O; CV group) or lung-protective (VT: 5 ml/kg, PEEP: 10 cm H2O; LPV group) ventilation for 12 h. Then, diaphragms and lungs were collected for biochemical and histological analyses. Transcriptome sequencing (RNA-seq) was performed to determine the differentially expressed genes in the diaphragms between groups. RESULTS: Our results suggested that LPV was associated with diminished pulmonary injuries and reduced oxidative stress compared with the effects of the CV strategy in rats. However, animals that received LPV showed increased protein degradation, decreased cross-sectional areas (CSAs) of myofibers, and reduced forces of the diaphragm compared with the same parameters in animals receiving CV (p < 0.05). In addition, the LPV group showed a higher level of oxidative stress in the diaphragm than the CV group (p < 0.05). Moreover, RNA-seq and western blots revealed that the peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α), a powerful reactive oxygen species (ROS) inhibitor, was significantly downregulated in the LPV group compared with its expression in the CV group (p < 0.05). CONCLUSIONS: Compared with the CV strategy, the LPV strategy did not protect the diaphragm against VIDD in rats. In contrast, the LPV strategy worsened VIDD by inducing oxidative stress together with the downregulation of PGC-1α in the diaphragm. However, further studies are required to determine the roles of PGC-1α in ventilator-induced diaphragmatic oxidative stress.

Quality retention of chest compression after repetitive practices with or without feedback devices: A randomized manikin study.

OBJECTIVES: This study was designed to investigate whether an audiovisual feedback (AVF) device is beneficial for quality retention of chest compression (CC) after repetitive practices (RP). METHODS: After completion of a 45-min CC-only cardiopulmonary resuscitation (CPR) training, participants performed 3 sessions of practices on days 1, 3, and 7 under the guidance of an instructor with (RP + AVF) or without (RP) the AVF device. CC quality was determined after each session and was retested at 3 and 12 months. RESULTS: In total, ninety-seven third year university students participated in this study. CC quality was improved after 3 sessions in both the RP and RP + AVF groups. Retests at 3 months showed that the proportions of appropriate CC rate and correct hand position were significantly decreased in the RP group as compared with the last practice (p < 0.05). However, no significant changes in CC quality were observed in the RP + AVF group. However, the proportions of appropriate CC rate, depth, and complete recoil were significantly decreased after 12 months in both RP and RP + AVF groups (p < 0.05). There were no significant differences in these parameters between the RP and the RP + AVF groups at 12 months after RP. CONCLUSION: With RP, the use of an AVF device further improves initial CC skill acquisition and short-term quality retention. However, long-term quality retention is not statistically different between rescuers who receive verbal human feedback only and those who receive additional AVF device feedback after RP.

Understanding the Roadmap for Electrochemical Reduction of CO2 to Multi-Carbon Oxygenates and Hydrocarbons on Copper-Based Catalysts.

Electrochemical reduction of CO2 to high-energy-density oxygenates and hydrocarbons beyond CO is important for long-term and large-scale renewable energy storage. However, the key step of the C-C bond formation needed for the generation of C2 products induces an additional barrier on the reaction. This inevitably creates larger overpotentials and greater variety of products as compared to the conversion of CO2 to C1 products. Therefore, an in-depth understanding of the catalytic mechanism is required for advancing the design of efficient electrocatalysts to control the reaction pathway to the desired products. Herein, we present a critical appraisal of reduction of CO2 to C2 products focusing on the connection between the fundamentals of reaction and efficient electrocatalysts. An in-depth discussion of the mechanistic aspects of various C2 reaction pathways on copper-based catalysts is presented together with consideration of practical factors under electrocatalytic operating conditions. By providing some typical examples illustrating the benefit of merging theoretical calculations, surface characterization, and electrochemical measurements, we try to address the key issues of the ongoing debate toward better understanding electrochemical reduction of CO2 at the atomic level and envisioning the roadmap for C2 products generation.

Hemorrhagic Shock Sensitized the Diaphragm to Ventilator-Induced Dysfunction through the Activation of IL-6/JAK/STAT Signaling-Mediated Autophagy in Rats.

Mechanical ventilation (MV) is a major life support technique for the management of trauma-associated hemorrhagic shock (HS). Ventilator-induced diaphragm dysfunction (VIDD), one of the most common complications of MV, has been well demonstrated in animal and human studies. However, few data are available concerning the effects of MV on diaphragm function in HS victims. In the present study, we found diaphragm muscle atrophy and weakness in HS but not in healthy animals after 4 hours of MV. The inhibition of autophagy resulted in reduced muscle fiber atrophy and improved forces. In addition, we observed diaphragmatic interleukin- (IL-) 6 overexpression and activation of its downstream signaling JAK/STAT in HS animals after MV, and either the neutralization of IL-6 or the inhibition of the JAK/STAT pathway attenuated autophagy, diaphragm atrophy, and weakness. Importantly, treatment with nonselective antioxidant exerted no protective effects against VIDD in HS animals. In addition, in vitro study showed that exogenous IL-6 was able to induce activation of JAK/STAT signaling and to increase autophagy in C2C12 cells. Moreover, the inhibition of JAK/STAT signaling abolished IL-6-induced cell autophagy. Together, our results suggested that HS sensitized the diaphragm to ventilator-induced atrophy and weakness through the activation of IL-6/JAK/STAT signaling-mediated autophagy in rats.

Thermal Instability Induced Oriented 2D Pores for Enhanced Sodium Storage.

Hierarchical porous structures are highly desired for various applications. However, it is still challenging to obtain such materials with tunable architectures. Here, this paper reports hierarchical nanomaterials with oriented 2D pores by taking advantages of thermally instable bonds in vanadium-based metal-organic frameworks (MOFs). High-temperature calcination of these MOFs accompanied by the loss of coordinated water molecules and other components enables the formation of orderly slit-like 2D pores in vanadium oxide/porous carbon nanorods (VOx /PCs). This unique combination leads to an increase of the reactive surface area. In addition, optimized VOx /PCs demonstrate high-rate capability and ultralong cycling life for sodium storage. The assembled full cells also show high capacity and cycling stability. This report provides an effective strategy for producing MOFs-derived composites with hierarchical porous architectures for energy storage.

Effect of bed width on the quality of compressions in simulated resuscitation: a randomized crossover manikin study.

OBJECTIVES: To investigate the effects of bed width on the quality of chest compressions during simulated in-hospital resuscitation. METHODS: Each candidate performed two 2-minute cycles of compression-only cardiopulmonary resuscitation on an adult manikin placed on either an emergency stretcher (narrow bed) or a standard hospital bed (wide bed) in random order at 1 day intervals. We conducted subjective assessments of cardiopulmonary resuscitation quality and rescuer fatigue at the end of each session, using surveys. RESULTS: There were no significant differences between narrow and wide bed sessions in either mean depth or the percentage of compressions with adequate depth (P=.56 and .58, respectively). The mean rate of compressions and the percentage of compressions with adequate rate were also similar between sessions (P=.24 and .27, respectively). However, the percentage of correct hand position and complete chest recoil was significantly higher in the narrow bed session than in the wide bed session (P=.02 and .02, respectively). In addition, survey results showed that rescuers felt more comfortable and less exhausted in the narrow bed session compared with the wide bed session (P<.001 and < .001). CONCLUSIONS: When rescuers performed chest compressions on an emergency stretcher, chest compression quality increased, and the fatigue of rescuers decreased compared with a standard hospital bed. Therefore, we propose a narrow bed for critically ill inpatients with high risk of cardiac arrest.

MOF-Derived Porous Co3O4 Hollow Tetrahedra with Excellent Performance as Anode Materials for Lithium-Ion Batteries.

Porous Co3O4 hollow tetrahedra were prepared through the thermolysis of metal-organic frameworks and presented reversible capacities of 1196 and 1052 mAh g(-1) at 50 and 200 mA g(-1) after 60 charge/discharge cycles, respectively. Such excellent performances stem from the well-defined hollow structure of Co3O4 tetrahedra.

Dominant hand position improves the quality of external chest compression: a manikin study based on 2010 CPR guidelines.

BACKGROUND: The 2010 cardiopulmonary resuscitation (CPR) guidelines increased the importance of external chest compression. However, the best hand position to be the compressing one has not been identified. OBJECTIVES: To investigate the effects of dominant or nondominant external chest compression hand position during CPR. METHODS: Medical students performed five cycles of conventional CPR and completed one questionnaire. The CPR performances were manually evaluated, and detailed aspects of the external chest compression quality were assessed via the SimMan® Essential system (Laerdal China Ltd., Hangzhou, China). RESULTS: One hundred fifty-seven students participated in the nondominant hand (NH) group, and 68 students participated in the dominant hand (DH) group. The manual evaluations revealed no differences between the two groups. The proportion of chest compressions "above 100 cpm [compressions per minute]" was higher in the DH group than in the NH group (97% vs. 92%, respectively, p = 0.002). The frequency distributions of the chest compression rates were also significantly different between the two groups (p < 0.0001). The distribution of the NH group was concentrated within "130-139" cpm, whereas this distribution was concentrated within "140-149" cpm in the DH group. The chest compression depth of the DH group was deeper than that of the NH group (p = 0.001). The depth of the fifth cycle was significantly decreased compared with those of cycles 1, 2, and 3 in the NH group. A greater number of full chest recoils were observed in the NH group (p = 0.02). CONCLUSION: The dominant hand position during CPR was associated with a higher chest compression rate, a greater chest compression depth, and delayed fatigue.

The First Introduction of Graphene to Rechargeable Li-CO2 Batteries.

The utilization of the greenhouse gas CO2 in energy-storage systems is highly desirable. It is now shown that the introduction of graphene as a cathode material significantly improves the performance of Li-CO2 batteries. Such batteries display a superior discharge capacity and enhanced cycle stability. Therefore, graphene can act as an efficient cathode in Li-CO2 batteries, and it provides a novel approach for simultaneously capturing CO2 and storing energy.

Medical students do not adversely affect the quality of cardiopulmonary resuscitation for ED patients.

OBJECTIVES: To investigate the effect of medical student involvement on the quality of actual cardiopulmonary resuscitation (CPR). METHODS: A digital video-recording system was used to record and analyze CPR procedures for adult patients from March 2011 to September 2012. RESULTS: Twenty-six student-involved and 40 non-student-involved cases were studied. The chest compression rate in the student-involved group was significantly higher than that in the non-student-involved group (P < .001). The proportion of compressions at "above 110 cpm" was higher in the student-involved group (P = .021), whereas the proportion at "90-110 cpm" was lower in the student-involved group (P = .015). The ratio of hands-off time to total manual compression time was significantly lower in the student-involved group than in the non-student-involved group (P = .04). In contrast, the student-involved group delivered a higher ventilation rate compared with the non-student-involved group (P = .02). The observed time delay to first compression and first ventilation were very similar between the groups. There were no significant differences between the groups in either return of spontaneous circulation or time from survival to discharge. CONCLUSION: Student-involved resuscitation teams were able to perform good CPR, with higher compression rates and fewer interruptions. However, the supervision from medical staff is still needed to ensure appropriate chest compression and ventilation rate in student-involved actual CPR in the emergency department.

Protective effects of lipoxin A4 in testis injury following testicular torsion and detorsion in rats.

PURPOSE: To investigate the protective effects of lipoxin A4 (LXA4) in rat testis injury following testicular torsion/detorsion. METHODS: A rat testicular torsion model has been established as described. Rats were randomly divided into 6 groups: sham group, torsion group, torsion/detorsion (T/D) group, and T/D plus LXA4-pretreated groups (3 subgroups). Rats in LXA4-pretreated groups received LXA4 injection (0.1, 1.0, and 10 µg/kg body weight in LXA4-pretreated subgroups 1-3, resp.) at a single dose 1 h before detorsion. Biochemical analysis, apoptosis assessment, and morphologic evaluation were carried out after orchiectomies. RESULTS: GPx and SOD levels significantly increased and MDA levels significantly reduced in LXA4-pretreated groups compared to T/D group. LXA4 also reverted IL-2 and TNF- α to basal levels and improved the expression of IL-4 and IL-10 in LXA4-pretreated groups. Moreover, the expression of NF- κ B was downregulated in LXA4-pretreated groups. LXA4 treatment also showed an improved testicular morphology and decreased apoptosis in testes. CONCLUSION: Lipoxin A4 protects rats against testes injury after torsion/detorsion via modulation of cytokines, oxidative stress, and NF- κ B activity.

Topological Transformation of Hydrogen-Terminated Germanium to Germanium Nanosheets for Fast Lithium Storage.

Germanium has been recognized as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity and excellent lithium-ion diffusivity. Nonetheless, it is challenging to enhance both the high-rate performance and long-term cycling stability simultaneously. This study introduces a novel heterostructure composed of germanium nanosheets integrated with graphene (Ge NSs@Gr). These nanosheets undergo an in situ phase transformation from a hydrogen-terminated multilayer germanium compound termed germanane (GeH) derived via topochemical deintercalation from CaGe2. This approach mitigates oxidation and prevents restacking by functionalizing the exfoliated germanane with octadecenoic organic molecules. The resultant germanium nanosheets retain their structural integrity from CaGe2 and present an exposed, active (111) surface that features an open crystal lattice, facilitating swift lithium-ion migration conducive to lithium storage. The composite material delivers a substantial reversible capacity of 1220 mA h g-1 at a current density of 0.2 C and maintains a capacity of 456 mA h g-1 even at an ultrahigh current density of 10 C over extended cycling. Impressively, a capacity of 316 mA h g-1 remains after 5000 cycles. The exceptional high-rate performance and durable cycling stability underscore the Ge NSs@Gr anode's potential as a highly viable option for LIBs.

Reverse biological engineering of hrdB to enhance the production of avermectins in an industrial strain of Streptomyces avermitilis.

Avermectin and its analogues are produced by the actinomycete Streptomyces avermitilis and are widely used in the field of animal health, agriculture, and human health. Here we have adopted a practical approach to successfully improve avermectin production in an industrial overproducer. Transcriptional levels of the wild-type strain and industrial overproducer in production cultures were monitored using microarray analysis. The avermectin biosynthetic genes, especially the pathway-specific regulatory gene, aveR, were up-regulated in the high-producing strain. The upstream promoter region of aveR was predicted and proved to be directly recognized by sigma(hrdB) in vitro. A mutant library of hrdB gene was constructed by error-prone PCR and selected by high-throughput screening. As a result of evolved hrdB expressed in the modified avermectin high-producing strain, 6.38 g/L of avermectin B1a was produced with over 50% yield improvement, in which the transcription level of aveR was significantly increased. The relevant residues were identified to center in the conserved regions. Engineering of the hrdB gene can not only elicit the overexpression of aveR but also allows for simultaneous transcription of many other genes. The results indicate that manipulating the key genes revealed by reverse engineering can effectively improve the yield of the target metabolites, providing a route to optimize production in these complex regulatory systems.

Agar-based hydrogel polymer electrolyte for high-performance zinc-ion batteries at all climatic temperatures.

Aqueous zinc-ion batteries (ZIBs) have received numerous attention because of their inherent safety and low cost. However, ZIBs are highly sensitive to temperature; the realization of full-temperature ZIBs is of great importance. In this study, an agar-based composite hydrogel polymer electrolyte (AG-HGPE) with the blend of agar and polyacrylamide (PAM) was prepared. It has a non-porous homogeneous structure, and shows various merits, e.g., strong liquid absorption rate, good mechanical properties, and large Zn2+ transference number. The corresponding Zn-symmetric cells possess reversible zinc stripping/plating phenomenon up to 500 h at a current density of 1 mA cm-2 and an areal capacity of 1 mAh cm-2. The Zn/AG-HGPE/V2O5 cells exhibit good rate performance and stable cyclic behaviors at -25°C, 25°C and 50°C, as well as excellent adaptability to the changes of ambient temperature. The research paves a new route for developing green energy storage devices running in wide temperature range.

Wearing N95 masks decreases the odor discrimination ability of healthcare workers: a self-controlled before-after study.

Objective: During the coronavirus disease 2019 (COVID-19) pandemic, the N95 mask is an essential piece of protective equipment for healthcare workers. However, the N95 mask may inhibit air exchange and odor penetration. Our study aimed to determine whether the use of N95 masks affects the odor discrimination ability of healthcare workers. Methods: In our study, all the participants were asked to complete three olfactory tests. Each test involved 12 different odors. The participants completed the test while wearing an N95 mask, a surgical mask, and no mask. The score for each olfactory test was documented. Results: The olfactory test score was significantly lower when the participants wore N95 masks than when they did not wear a mask (7 vs. 10, p < 0.01). The score was also lower when the participants wore N95 masks than surgical masks (7 vs. 8, p < 0.01). Conclusion: Wearing N95 masks decreases the odor discrimination ability of healthcare workers. Therefore, we suggest that healthcare workers seek other clues when diagnosing disease with a characteristic odor.