Rapid preparation of injectable dual-network hydrogels for biomedical applications using UV-triggered sulfhydryl click reactions.

The use of hydrogels to mimic natural cartilage implantation can effectively solve the current problems of insufficient cartilage donors and low rate of injury healing. In particular, injectable hydrogels are less invasive in clinical applications and better able to fill uneven injury surfaces. Here, we prepared NorCS and CS-SH by modifying chitosan with 5-norbornene-2-carboxylic acid and N-Acetyl-L-cysteine, respectively. Dual-network hydrogels were prepared by using UV-triggered thiol-ene click reaction between NorCS and CS-SH and the metal coordination between SA and Ca2+. The prepared hydrogels can be cross-linked quickly and exhibit excellent degradability, self-healing and injectable properties. At the same time, the hydrogel also showed good cytocompatibility and could significantly restore the motor function of mice. This study provides an effective strategy for preparing injectable hydrogels capable of rapid cross-linking.

A novel olfactory sorting task.

BACKGROUND: This study aimed to develop a simple self-administered screening tool for odor memory, which allowed users to self-test their olfactory function repeatedly even at home. METHODS: One hundred and ten participants were recruited (30 men, age = 50.1 ± 9.9 years; 80 women, age = 47.1 ± 11.5 years); half of them were heathy volunteers, the other half were patients with olfactory dysfunction. Fifty-one healthy participants volunteered for a retest within an interval of a maximum of 14 days. Olfactory function was assessed using the extended Sniffin' Sticks test (SST) comprising tests for odor threshold, identification, and discrimination. All participants received the Novel Olfactory Sorting Task (NOST) which is based on the sorting of 12 matching pairs of odors involving olfactory and cognitive functions. After that, all participants rated questions related to their test performance and the practicability of the test. RESULTS: Consistent with the previous literature, significant effects of age were found. Results showed an acceptable test-retest reliability and a satisfactory validity of the NOST. The NOST score not only had positive correlations with SST, but also was capable of differentiating severe hyposmia/anosmia from normosmia by the score of 5.5 (sensitivity of 76.2%, specificity of 77.6%). CONCLUSION: The present study showed the good reliability, validity, and possible clinical usefulness of the NOST. As a self-performed screening test, it can be comprehended and conducted easily, which may provide a quick and simple approach to obtaining a global estimation of olfactory and cognitive functions.

Protective Effects of Lactoferrin Treatment Against Sodium Arsenite Exposure-Induced Nephrotoxicity.

It is said that a wide range of renal functions are at risk from arsenic exposure. We examined how lactoferrin administration may mitigate inflammation, apoptosis, redox imbalance, and fibrosis in order to counteract arsenic-induced nephrotoxicity. Accordingly, male C57BL/6 mice (6 weeks) were divided into six experimental groups with six mice in each group. The first and second groups were intragastrically administered normal saline and sodium arsenite (NaAsO2) at 5 mg/kg body weight concentrations as the negative control (NC) and NaAsO2 groups. The third, fourth, and fifth groups were intragastrically administered lactoferrin at concentrations of 100, 200, and 400 mg/kg body weight in addition to NaAsO2 at concentrations of 5 mg/kg body weight. The sixth group was intragastrically administered lactoferrin at a concentration of 200 mg/kg body weight with the experimental group set as the lactoferrin group. After daily drug administration for 4 weeks, the lactoferrin concentrations were optimized based on the results of renal index and renal function. Histopathological, biochemical, and gene expression analyses were performed to evaluate the status of renal tissue architecture, redox imbalance, inflammation, apoptosis, and fibrosis to confirm the alleviative effect of lactoferrin treatment against the NaAsO2 exposure-induced nephrotoxicity. The results confirmed that the 200 mg/kg lactoferrin treatment mitigated these arsenic effects and maintained the normal renal frameworks. Conclusively, disrupting the renal redox balance and triggering inflammation, apoptosis, along with fibrosis is a milieu that arsenic, robustly exerts its nephrotoxic effect. Lactoferrin, probably by its direct and indirect control mechanism on these said pathways, can mitigate the nephrotoxicity and preserve the normal renal health.

Effect of Gentianella acuta (Michx.) Hulten against the arsenic-induced development hindrance of mouse oocytes.

The current study was designed to investigate the alleviative effect of Gentianella acuta (Michx.) Hulten (G. acuta) against the sodium arsenite (NaAsO2)-induced development hindrance of mouse oocytes. For this purpose, the in vitro maturation (IVM) of mouse cumulus-oocyte complexes (COCs) was conducted in the presence of NaAsO2 and G. acuta, followed by the assessments of IVM efficiency including oocyte maturation, spindle organization, chromosome alignment, cytoskeleton assembly, cortical granule (CGs) dynamics, redox regulation, epigenetic modification, DNA damage, and apoptosis. Subsequently, the alleviative effect of G. acuta intervention on the fertilization impairments of NaAsO2-exposed oocytes was confirmed by the assessment of in vitro fertilization (IVF). The results showed that the G. acuta intervention effectively ameliorated the decreased maturation potentials and fertilization deficiency of NaAsO2-exposed oocytes but also significantly inhibited the DNA damages, apoptosis, and altered H3K27me3 expression level in the NaAsO2-exposed oocytes. The effective effects of G. acuta intervention against redox dysregulation including mitochondrial dysfunctions, accumulated reactive oxygen species (ROS) generation, glutathione (GSH) deficiency, and decreased adenosine triphosphate (ATP) further confirmed that the ameliorative effects of G. acuta intervention against the development hindrance of mouse oocytes were positively related to the antioxidant capacity of G. acuta. Evidenced by these abovementioned results, the present study provided fundamental bases for the ameliorative effect of G. acuta intervention against the meiotic defects caused by the NaAsO2 exposure, benefiting the future application potentials of G. acuta intervention in these nutritional and therapeutic research for attenuating the outcomes of arseniasis.

A chimeric porcine reproductive and respiratory syndrome virus 1 strain containing synthetic ORF2-6 genes can trigger T follicular helper cell and heterologous neutralizing antibody responses and confer enhanced cross-protection.

The prevalence of porcine reproductive and respiratory syndrome virus 1 (PRRSV1) isolates has continued to increase in Chinese swine herds in recent years. However, no effective control strategy is available for PRRSV1 infection in China. In this study, we generated the first infectious cDNA clone (rHLJB1) of a Chinese PRRSV1 isolate and subsequently used it as a backbone to construct an ORF2-6 chimeric virus (ORF2-6-CON). This virus contained a synthesized consensus sequence of the PRRSV1 ORF2-6 gene encoding all the envelope proteins. The ORF2-6 consensus sequence shared > 90% nucleotide similarity with four representative strains (Amervac, BJEU06-1, HKEU16 and NMEU09-1) of PRRSV1 in China. ORF2-6-CON had replication efficacy similar to that of the backbone rHLJB1 virus in primary alveolar macrophages (PAMs) and exhibited cell tropism in Marc-145 cells. Piglet inoculation and challenge studies indicated that ORF2-6-CON is not pathogenic to piglets and can induce enhanced cross-protection against a heterologous SD1291 isolate. Notably, ORF2-6-CON inoculation induced higher levels of heterologous neutralizing antibodies (nAbs) against SD1291 than rHLJB1 inoculation, which was concurrent with a higher percentage of T follicular helper (Tfh) cells in tracheobronchial lymph nodes (TBLNs), providing the first clue that porcine Tfh cells are correlated with heterologous PRRSV nAb responses. The number of SD1291-strain-specific IFNγ-secreting cells was similar in ORF2-6-CON-inoculated and rHLJB1-inoculated pigs. Overall, our findings support that the Marc-145-adapted ORF2-6-CON can trigger Tfh cell and heterologous nAb responses to confer improved cross-protection and may serve as a candidate strain for the development of a cross-protective PRRSV1 vaccine.

Xylem plasticity of root, stem, and branch in Cunninghamia lanceolata under drought stress: implications for whole-plant hydraulic integrity.

Introduction: A better understanding of xylem hydraulic characteristics in trees is critical to elucidate the mechanisms of forest decline and tree mortality from water deficit. As well as temperate forests and forests growing in arid regions, subtropical and tropical forests are also predicted to experience an increased frequency and intensity of climate change-induced drought in the near future. Methods: In this study, 1-year-old Cunninghamia lanceolata seedlings (a typical subtropical species in southern China) were selected for a continuous controlled drought pot experiment of 45 days duration. The experimental treatments were non-drought (control), light drought, moderate drought and severe drought stress, which were 80%, 60%, 50%, and 40%, respectively of soil field maximum moisture capacity. Results: The hydraulic conductivity, specific conductivity and water potential of roots, stems, and branches of C. lanceolata all decreased with the prolonging of drought in the different drought intensities. The relative decrease in these hydraulic values were greater in roots than in stems and branches, indicating that roots are more sensitive to drought. Root tracheid diameters normally reduce to ensure security of water transport with prolonged drought, whilst the tracheid diameters of stems and branches expand initially to ensure water transport and then decrease to reduce the risk of embolism with continuing drought duration. The pit membrane diameter of roots, stems and branches generally increased to different extents during the 15-45 days drought duration, which is conducive to enhanced radial water transport ability. The tracheid density and pit density of stems generally decreased during drought stress, which decreased water transport efficiency and increased embolism occurrence. Correlation analysis indicated that anatomical plasticity greatly influenced the hydraulic properties, whilst the relationships varied among different organs. In roots, tracheid diameter decreased and tracheid density increased to enhance water transport security; stems and branches may increase tracheid diameter and pit membrane diameter to increase hydraulic conductivity ability, but may increase the occurrence of xylem embolism. Discussion: In summary, under drought stress, the xylem anatomical characteristics of C. lanceolata organs were highly plastic to regulate water transport vertically and radially to maintain the trade-off between hydraulic conductivity efficiency and safety.

Oscillation of type IV pili regulated by the circadian clock in cyanobacterium Synechococcus elongatus PCC7942.

Type IV pili (TFP) are known to be functionally related to cell motilities and natural transformation in many bacteria. However, the molecular and ecological functions of the TFP have rarely been reported for photosynthetic cyanobacteria. Here, by labeling pili in model cyanobacterium Synechococcus elongatus PCC 7942 (Syn7942), we have quantitatively characterized the TFP and its driven twitching motility in situ at the single-cell level. We found an oscillating pattern of TFP in accordance with the light and dark periods during light-dark cycles, which is correlated positively to the oscillating pattern of the natural transformation efficiency. We further showed that the internal circadian clock plays an important role in regulating the oscillating pattern of TFP, which is also supported by evidences at the molecular level by tracking the expression of 16 TFP-related genes. This study adds a detailed picture toward the gap between TFP and its relations to circadian regulations in Syn7942.

Efficacy of Electronic Cigarettes vs Varenicline and Nicotine Chewing Gum as an Aid to Stop Smoking: A Randomized Clinical Trial.

Importance: Electronic cigarettes (ECs) are often used by smokers as an aid to stopping smoking, but evidence is limited regarding their efficacy compared with nicotine replacement therapy (NRT), and no evidence is available on how their efficacy compares with that of varenicline. Objective: To evaluate whether ECs are superior to NRT and noninferior to varenicline in helping smokers quit. Design, Setting, and Participants: This was a randomized clinical trial conducted at 7 sites in China and including participants who were smoking at least 10 cigarettes per day and motivated to quit, not using stop-smoking medications or EC, and willing to use any of the study products. Participants were first recruited in May 2021, and data analysis was conducted in December 2022. Interventions: A cartridge-based EC (30 mg/mL nicotine salt for 2 weeks and 50 mg/mL after that), varenicline (0.5 mg, once a day for 3 days; 0.5 mg, twice a day for 4 days; and 1 mg, twice a day, after that), and 2 mg (for smokers of ≤20 cigarettes per day) or 4 mg (>20 cigarettes per day) nicotine chewing gum, all provided for 12 weeks and accompanied by minimal behavioral support (an invitation to join a self-help internet forum). Main Outcomes and Measures: The primary outcome was sustained abstinence from smoking at 6 months as validated by an expired-air carbon monoxide reading (<8 parts per million). Participants lost to follow-up were included as nonabstainers. Results: Of 1068 participants, 357 (33.5%) were female, and the mean (SD) age was 33.9 (3.1) years. A total of 409 (38.3%), 409 (38.3%), and 250 (23.4%) participants were randomized to the EC, varenicline, and NRT arms, respectively. The 6-month biochemically validated abstinence rates were 15.7% (n = 64), 14.2% (n = 58), and 8.8% (n = 22) in the EC, varenicline, and NRT study arms, respectively. The quit rate in the EC arm was noninferior to the varenicline arm (absolute risk reduction, 1.47%; 95% CI, -1.41% to 4.34%) and higher than in the NRT arm (odds ratio, 1.92; 95% CI, 1.15-3.21). Treatment adherence was similar in all study arms during the initial 3 months, but 257 participants (62.8%) in the EC arm were still using ECs at 6 months, with no further use in the 2 other study arms. The most common adverse reactions were throat irritation (32 [7.8%]) and mouth irritation (28 [6.9%]) in the EC arm, nausea (36 [8.8%]) in the varenicline arm, and throat irritation (20 [8.0%]) and mouth irritation (22 [8.8%]) in the NRT arm. No serious adverse events were recorded. Conclusions and Relevance: The results of this randomized clinical trial found that when all treatments were provided with minimal behavior support, the efficacy of EC was noninferior to varenicline and superior to nicotine chewing gum. Trial Registration: Chinese Clinical Trial Registry: ChiCTR2100048156.

Genetically encoded zinc-binding collagen-like protein hybrid hydrogels for wound repair.

Incorporating zinc oxide nanoparticles (ZnOnps) into collagen is a promising strategy for fabricating biomaterials with excellent antibacterial activity, but modifications are necessary due to the low zinc binding affinity of native collagen, which can cause disturbances to the functions of both ZnOnps and collagen and result in heterogeneous effects. To address this issue, we have developed a genetically encoded zinc-binding collagen-like protein, Zn-eCLP3, which was genetically modified by Scl2 collagen-like protein. Our study found that Zn-eCLP3 has a binding affinity for zinc that is 3-fold higher than that of commercialized type I collagen, as determined by isothermal titration calorimetry (ITC). Using ZnOnps-coordinated Zn-eCLP3 protein and xanthan gum, we prepared a hydrogel that showed significantly stronger antibacterial activity compared to a collagen hydrogel prepared in the same manner. In vitro cytocompatibility tests were conducted to assess the potential of the Zn-eCLP3 hydrogel for wound repair applications. In vivo experiments, which involved an S. aureus-infected mouse trauma model, showed that the application of the Zn-eCLP3 hydrogel resulted in rapid wound regeneration and increased expression of collagen-1α and cytokeratin-14. Our study highlights the potential of Zn-eCLP3 and the hybrid hydrogel for further studies and applications in wound repair.

Fast-growing cyanobacterial chassis for synthetic biology application.

Carbon neutrality by 2050 has become one of the most urgent challenges the world faces today. To address the issue, it is necessary to develop and promote new technologies related with CO2 recycling. Cyanobacteria are the only prokaryotes performing oxygenic photosynthesis, capable of fixing CO2 into biomass under sunlight and serving as one of the most important primary producers on earth. Notably, recent progress on synthetic biology has led to utilizing model cyanobacteria such as Synechocystis sp. PCC 6803 and Synechococcus elongatus PCC 7942 as chassis for "light-driven autotrophic cell factories" to produce several dozens of biofuels and various fine chemicals directly from CO2. However, due to the slow growth rate and low biomass accumulation in the current chassis, the productivity for most products is still lower than the threshold necessary for large-scale commercial application, raising the importance of developing high-efficiency cyanobacterial chassis with fast growth and/or higher biomass accumulation capabilities. In this article, we critically reviewed recent progresses on identification, systems biology analysis, and engineering of fast-growing cyanobacterial chassis. Specifically, fast-growing cyanobacteria identified in recent years, such as S. elongatus UTEX 2973, S. elongatus PCC 11801, S. elongatus PCC 11802 and Synechococcus sp. PCC 11901 was comparatively analyzed. In addition, the progresses on their recent application in converting CO2 into chemicals, and genetic toolboxes developed for these new cyanobacterial chassis were discussed. Finally, the article provides insights into future challenges and perspectives on the synthetic biology application of cyanobacterial chassis.

Alleviative Effect of Lactoferrin Interventions Against the Hepatotoxicity Induced by Titanium Dioxide Nanoparticles.

The current study was designed to investigate the alleviative effect of lactoferrin interventions against the hepatotoxicity induced by titanium dioxide nanoparticles (TiO2-NPs). Thirty male Wistar rats were divided into six groups with 5 rats in each group. The first and second groups were intragastrically administered normal saline and TiO2-NPs (100 mg/kg body weight) as the negative control (NC) and TiO2-NP groups. The third, fourth, and fifth groups were intragastrically administered lactoferrin at concentrations of 100, 200, and 400 mg/kg body weight in addition to TiO2-NPs (100 mg/kg body weight). The sixth group was intragastrically administered Fuzheng Huayu (FZHY) capsules at a concentration of 4.6 g/kg body weight in addition to TiO2-NPs (100 mg/kg body weight) as the positive control group. After treatment for 4 weeks, the concentrations of lactoferrin were optimized based on the liver index and function results. Subsequently, the alleviative effects of lactoferrin interventions against TiO2-NP-induced hepatotoxicity in rat liver tissues, including the effects on histological damage, oxidative stress-related damage, inflammation, fibrosis, DNA damage, apoptosis, and gene expression, were investigated using histopathological, biochemical, and transcriptomic assays. The results showed that 200 mg/kg lactoferrin interventions for 4 weeks not only ameliorated the liver dysfunction and histopathological damage caused by TiO2-NP exposure but also inhibited the oxidative stress-related damage, inflammation, fibrosis, DNA damage, and apoptosis in the liver tissues of TiO2-NP-exposed rats. The transcriptomic results confirmed that the alleviative effect of lactoferrin interventions against the TiO2-NP exposure-induced hepatotoxicity was related to the activation of the PI3K/AKT signaling pathway.

Regulation of species metabolism in synthetic community systems by environmental pH oscillations.

Constructing a synthetic community system helps scientist understand the complex interactions among species in a community and its environment. Herein, a two-species community is constructed with species A (artificial cells encapsulating pH-responsive molecules and sucrose) and species B (Saccharomyces cerevisiae), which causes the environment to exhibit pH oscillation behaviour due to the generation and dissipation of CO2. In addition, a three-species community is constructed with species A' (artificial cells containing sucrose and G6P), species B, and species C (artificial cells containing NAD+ and G6PDH). The solution pH oscillation regulates the periodical release of G6P from species A'; G6P then enters species C to promote the metabolic reaction that converts NAD+ to NADH. The location of species A' and B determines the metabolism behaviour in species C in the spatially coded three-species communities with CA'B, CBA', and A'CB patterns. The proposed synthetic community system provides a foundation to construct a more complicated microecosystem.

The Dunning-Kruger effect: subjective health perceptions on smoking behavior among older Chinese adults.

BACKGROUND: The intrinsic damage and external hazards of smoking are major risk factors for poorer health and are recognized as a global health issue of concern in geriatric health. This study aims to assess the Dunning-Kruger effect through the influence of subjective health perceptions on smoking behavior in older adults. METHODS: This study used data from the 2018 Chinese Longitudinal Healthy Longevity Survey (N = 9,683) provided by the Center for Healthy Aging and Development Studies at Peking University. A binary logistic model was used to examine whether the Dunning-Kruger effect affects smoking behavior in older adults, and a linear probability model was used as a commentary baseline model for logistic regression to prevent measurement bias. In addition, a mediating analysis was used to examine the mechanisms through which the Dunning-Kruger effect occurs. RESULTS: Older adults often overestimated their current health status and underestimated the health risks of smoking, causing the Dunning-Kruger effect to arise from their inadequate self-perceived health (i.e., older adults are more likely to smoke when they have better self-rated health or when hypertension, cardiopathy, stroke, and diabetes have little or no impact on their daily lives). These observations can be explained by the older adults' subjective health perceptions arising from their ingenuous understanding of their health, which indirectly influences their smoking behavior to some extent. CONCLUSION: Older adults' self-perceived health was associated with smoking behavior. Public health institutions should improve older adults' health perceptions so that they objectively understand their own health status.

Genetically encoded in situ gelation redox-responsive collagen-like protein hydrogel for accelerating diabetic wound healing.

Genetically encoded collagen-like protein-based hydrogels have demonstrated remarkable efficacy in promoting the healing process in diabetic patients. However, the current methods for preparing these hydrogels pose significant challenges due to harsh reaction conditions and the reliance on chemical crosslinkers. In this study, we present a genetically encoded approach that allows for the creation of protein hydrogels without the need for chemical additives. Our design involves the genetic encoding of paired-cysteine residues at the C- and N-terminals of a meticulously engineered collagen-like recombination protein. The protein-based hydrogel undergoes a gel-sol transition in response to redox stimulation, achieving a gel-sol transition. We provide evidence that the co-incubation of the protein hydrogel with 3T3 cells not only enhances cell viability but also promotes cell migration. Moreover, the application of the protein hydrogel significantly accelerates the healing of diabetic wounds by upregulating the expression of collagen-1α (COL-1α) and Cytokeratin 14 (CK-14), while simultaneously reducing oxidant stress in the wound microenvironment. Our study highlights a straightforward strategy for the preparation of redox-responsive protein hydrogels, removing the need for additional chemical agents. Importantly, our findings underscore the potential of this hydrogel system for effectively treating diabetic wounds, offering a promising avenue for future therapeutic applications.

Efficacy of a porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) natural recombinant against a heterologous PRRSV-1 isolate both clustered within the subgroup of BJEU06-1-like isolates.

Porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) has been prevalent in more than 20 provinces of China. However, no PRRSV-1-specific vaccine is commercially available in China. To evaluate the feasibility of using a low virulent PRRSV-1 isolate against potential outbreaks caused by virulent Chinese PRRSV-1 isolates, here we evaluated the efficacy of a low virulent PRRSV-1 HLJB1 strain isolated in 2014 as live vaccine against a virulent PRRSV-1 SD1291 strain isolated in 2022. Genome-based phylogenetic analysis showed that both HLJB1 and SD1291 were grouped within BJEU06-1-like isolates. However, they shared only 85.27% genomic similarity. Piglet inoculation and challenge study showed that HLJB1 inoculation could reduce viremia but did not significantly alleviate clinical signs and tissue lesions. Virus neutralization test indicated that HLJB1 inoculation could induce homologous neutralizing antibodies (NAbs) but no heterologous NAbs at 42 dpi. In addition, flow cytometric analyses showed that no memory T follicular helper (Tfh) cells against SD1291 and SD1291-specific IFN-γ secreting cells were induced by HLJB1 pre-inoculation. These results supported that HLJB1 inoculation only provides partial cross-protection against SD1291 infection even though they are clustered within the same PRRSV-1 subgroup, which is closely related to the failure in conferring cross-protective adaptive immune responses.

Effects of Drought Stress on Non-Structural Carbohydrates in Different Organs of Cunninghamia lanceolata.

The Chinese fir Cunninghamia lanceolata (Lamb.) Hook. is an important timber conifer species in China. Much has been studied about Chinese fir, but the distribution of non-structural carbohydrates (NSCs) among different organs (needles, branch, stem, and roots) under drought stress remains poorly understood. In this study, we used one-year-old C. lanceolata plantlets to evaluate the effects of simulated drought under four water regimes, i.e., adequate water or control, light drought, moderate drought, and severe drought stress corresponding to 80%, 60%, 50%, and 40%, respectively of soil field maximum capacity on various NSCs in the needles, branch, stem and roots. The degree and duration of drought stress had significant effects on fructose, glucose, sucrose, soluble sugar, starch, and NSC content in various organs (p < 0.05). Fructose content increased in stem xylem, stem phloem, and leaves. Glucose and sucrose content declined in stem and branch xylem under light drought stress and moderate drought stress, and increased under severe drought stress conditions. Soluble sugars content declined, and starch content increased in leaf and branch phloem, but the latter could not compensate for soluble sugar consumption in the whole plant, and therefore, total NSCs decreased. Correlation analysis showed that a significant positive correlation existed in the soluble sugar content between leaves and roots, and between xylem and phloem in the stems and branches. Chinese fir appears to have different NSCs distribution strategies in response to drought stress, viz., allocating more soluble sugars to fine roots and increasing starch content in the needles, as well as ensuring osmosis to prevent xylem embolism. Our study may broaden the understanding of the various mechanisms that Chinese fir and other plants have to enhance their tolerance to drought stress.

Orthonasal and retronasal odor identification in patients with parosmia.

OBJECTIVE: To compare retronasal and orthonasal perception in parosmic COVID-19 patients, in order to determine whether COVID-19 has a differential effect on these functions. METHODS: Using the Sniffin Sticks test battery orthonasal function was examined for odor threshold, discrimination and identification. Retronasal function was assessed using 20 tasteless aromatized powders. Gustatory function was measured using the Taste Strips test. RESULTS: This study included 177 patients (127 women, 50 men; mean age 45 years), of whom 127 (72%) were hyposmic and 50 (28%) normosmic. Compared to patients without parosmia, parosmic patients performed worse in odor identification for both orthonasal (F = 4.94, p = 0.03) and retronasal tests (F = 11.95, p < 0.01). However, an interaction effect between route of odor identification (orthonasal or retronasal) and parosmia status was found (F = 4.67, p = 0.03): patients with parosmia had relatively lower retronasal scores than patients without parosmia. CONCLUSION: Our results suggest that COVID-19 may affect the olfactory mucosa differently along the anterior-posterior axis, thereby possibly contributing to the pathophysiology of parosmia. Patients with parosmia also exhibit a higher degree of impairment when odors are presented through the retronasal route during eating and drinking.

Pressure-induced nonmonotonic cross-over of steady relaxation dynamics in a metallic glass.

Relaxation dynamics, as a key to understand glass formation and glassy properties, remains an elusive and challenging issue in condensed matter physics. In this work, in situ high-pressure synchrotron high-energy X-ray photon correlation spectroscopy has been developed to probe the atomic-scale relaxation dynamics of a cerium-based metallic glass during compression. Although the sample density continuously increases, the collective atomic motion initially slows down as generally expected and then counterintuitively accelerates with further compression (density increase), showing an unusual nonmonotonic pressure-induced steady relaxation dynamics cross-over at ~3 GPa. Furthermore, by combining in situ high-pressure synchrotron X-ray diffraction, the relaxation dynamics anomaly is evidenced to closely correlate with the dramatic changes in local atomic structures during compression, rather than monotonically scaling with either sample density or overall stress level. These findings could provide insight into relaxation dynamics and their relationship with local atomic structures of glasses.