SARS-CoV-2 spike-FLIPr fusion protein plus lipidated FLIPr protects against various SARS-CoV-2 variants in hamsters.

Vaccine-induced mucosal immunity and broad protective capacity against various severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants remain inadequate. Formyl peptide receptor-like 1 inhibitory protein (FLIPr), produced by Staphylococcus aureus, can bind to various Fcγ receptor subclasses. Recombinant lipidated FLIPr (rLF) was previously found to be an effective adjuvant. In this study, we developed a vaccine candidate, the recombinant Delta SARS-CoV-2 spike (rDS)-FLIPr fusion protein (rDS-F), which employs the property of FLIPr binding to various Fcγ receptors. Our study shows that rDS-F plus rLF promotes rDS capture by dendritic cells. Intranasal vaccination of mice with rDS-F plus rLF increases persistent systemic and mucosal antibody responses and CD4/CD8 T-cell responses. Importantly, antibodies induced by rDS-F plus rLF vaccination neutralize Delta, Wuhan, Alpha, Beta, and Omicron strains. Additionally, rDS-F plus rLF provides protective effects against various SARS-CoV-2 variants in hamsters by reducing inflammation and viral loads in the lung. Therefore, rDS-F plus rLF is a potential vaccine candidate to induce broad protective responses against various SARS-CoV-2 variants.IMPORTANCEMucosal immunity is vital for combating pathogens, especially in the context of respiratory diseases like COVID-19. Despite this, most approved vaccines are administered via injection, providing systemic but limited mucosal protection. Developing vaccines that stimulate both mucosal and systemic immunity to address future coronavirus mutations is a growing trend. However, eliciting strong mucosal immune responses without adjuvants remains a challenge. In our study, we have demonstrated that using a recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike-formyl peptide receptor-like 1 inhibitory protein (FLIPr) fusion protein as an antigen, in combination with recombinant lipidated FLIPr as an effective adjuvant, induced simultaneous systemic and mucosal immune responses through intranasal immunization in mice and hamster models. This approach offered protection against various SARS-CoV-2 strains, making it a promising vaccine candidate for broad protection. This finding is pivotal for future broad-spectrum vaccine development.

Dysfunction of Avo3, an essential component of target of rapamycin complex 2, induces ubiquitin-proteasome-dependent downregulation of Avo2 in Saccharomyces cerevisiae.

The ubiquitin-proteasome system (UPS) plays a key role in maintaining cellular protein homeostasis and participates in modulating various cellular functions. Target of rapamycin (TOR), a highly conserved Ser/Thr kinase found across species from yeasts to humans, forms two multi-protein complexes, TORC1 and TORC2, to orchestrate cellular processes crucial for optimal growth, survival, and stress responses. While UPS-mediated regulation of mammalian TOR complexes has been documented, the ubiquitination of yeast TOR complexes remains largely unexplored. Here we report a functional interplay between the UPS and TORC2 in Saccharomyces cerevisiae. Using avo3-2ts, a temperature-sensitive mutant of the essential TORC2 component Avo3 exhibiting TORC2 defects at restrictive temperatures, we obtained evidence for UPS-dependent protein degradation and downregulation of the TORC2 component Avo2. Our results established the involvement of the E3 ubiquitin ligase Ubr1 and its catalytic activity in mediating Avo2 degradation in cells with defective Avo3. Coimmunoprecipitation revealed the interaction between Avo2 and Ubr1, indicating Avo2 as a potential substrate of Ubr1. Furthermore, depleting Ubr1 rescued the growth of avo3-2ts cells at restrictive temperatures, suggesting an essential role of Avo2 in sustaining cell viability under heat stress and/or TORC2 dysfunction. This study uncovers a role of UPS in yeast TORC2 regulation, highlighting the impact of protein degradation control on cellular signaling.

Induction of high affinity monoclonal antibodies against SARS-CoV-2 variant infection using a DNA prime-protein boost strategy.

BACKGROUND: Calls for the coronavirus to be treated as an endemic illness, such as the flu, are increasing. After achieving high coverage of COVID-19 vaccination, therapeutic drugs have become important for future SARS-CoV-2 variant outbreaks. Although many monoclonal antibodies have been approved for emergency use as treatments for SARS-CoV-2 infection, some monoclonal antibodies are not authorized for variant treatment. Broad-spectrum monoclonal antibodies are unmet medical needs. METHODS: We used a DNA prime-protein boost approach to generate high-quality monoclonal antibodies. A standard ELISA was employed for the primary screen, and spike protein-human angiotensin-converting enzyme 2 blocking assays were used for the secondary screen. The top 5 blocking clones were selected for further characterization, including binding ability, neutralization potency, and epitope mapping. The therapeutic effects of the best monoclonal antibody against SARS-CoV-2 infection were evaluated in a hamster infection model. RESULTS: Several monoclonal antibodies were selected that neutralize different SARS-CoV-2 variants of concern (VOCs). These VOCs include Alpha, Beta, Gamma, Delta, Kappa and Lambda variants. The high neutralizing antibody titers against the Beta variant would be important to treat Beta-like variants. Among these monoclonal antibodies, mAb-S5 displays the best potency in terms of binding affinity and neutralizing capacity. Importantly, mAb-S5 protects animals from SARS-CoV-2 challenge, including the Wuhan strain, D614G, Alpha and Delta variants, although mAb-S5 exhibits decreased neutralization potency against the Delta variant. Furthermore, the identified neutralizing epitopes of monoclonal antibodies are all located in the receptor-binding domain (RBD) of the spike protein but in different regions. CONCLUSIONS: Our approach generates high-potency monoclonal antibodies against a broad spectrum of VOCs. Multiple monoclonal antibody combinations may be the best strategy to treat future SARS-CoV-2 variant outbreaks.

Feedback Regulation of O-GlcNAc Transferase through Translation Control to Maintain Intracellular O-GlcNAc Homeostasis.

Protein O-GlcNAcylation is a dynamic post-translational modification involving the attachment of N-acetylglucosamine (GlcNAc) to the hydroxyl groups of Ser/Thr residues on numerous nucleocytoplasmic proteins. Two enzymes are responsible for O-GlcNAc cycling on substrate proteins: O-GlcNAc transferase (OGT) catalyzes the addition while O-GlcNAcase (OGA) helps the removal of GlcNAc. O-GlcNAcylation modifies protein functions; therefore, dysregulation of O-GlcNAcylation affects cell physiology and contributes to pathogenesis. To maintain homeostasis of cellular O-GlcNAcylation, there exists feedback regulation of OGT and OGA expression responding to fluctuations of O-GlcNAc levels; yet, little is known about the molecular mechanisms involved. In this study, we investigated the O-GlcNAc-feedback regulation of OGT and OGA expression in lung cancer cells. Results suggest that, upon alterations in O-GlcNAcylation, the regulation of OGA expression occurs at the mRNA level and likely involves epigenetic mechanisms, while modulation of OGT expression is through translation control. Further analyses revealed that the eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) contributes to the downregulation of OGT induced by hyper-O-GlcNAcylation; the S5A/S6A O-GlcNAcylation-site mutant of 4E-BP1 cannot support this regulation, suggesting an important role of O-GlcNAcylation. The results provide additional insight into the molecular mechanisms through which cells may fine-tune intracellular O-GlcNAc levels to maintain homeostasis.

Gene Expression Profile in Primary Tumor Is Associated with Brain-Tropism of Metastasis from Lung Adenocarcinoma.

Lung adenocarcinoma has a strong propensity to metastasize to the brain. The brain metastases are difficult to treat and can cause significant morbidity and mortality. Identifying patients with increased risk of developing brain metastasis can assist medical decision-making, facilitating a closer surveillance or justifying a preventive treatment. We analyzed 27 lung adenocarcinoma patients who received a primary lung tumor resection and developed metastases within 5 years after the surgery. Among these patients, 16 developed brain metastases and 11 developed non-brain metastases only. We performed targeted DNA sequencing, RNA sequencing and immunohistochemistry to characterize the difference between the primary tumors. We also compared our findings to the published data of brain-tropic and non-brain-tropic lung adenocarcinoma cell lines. The results demonstrated that the targeted tumor DNA sequencing did not reveal a significant difference between the groups, but the RNA sequencing identified 390 differentially expressed genes. A gene expression signature including CDKN2A could identify 100% of brain-metastasizing tumors with a 91% specificity. However, when compared to the differentially expressed genes between brain-tropic and non-brain-tropic lung cancer cell lines, a different set of genes was shared between the patient data and the cell line data, which include many genes implicated in the cancer-glia/neuron interaction. Our findings indicate that it is possible to identify lung adenocarcinoma patients at the highest risk for brain metastasis by analyzing the primary tumor. Further investigation is required to elucidate the mechanism behind these associations and to identify potential treatment targets.

Human Costars Family Protein ABRACL Modulates Actin Dynamics and Cell Migration and Associates with Tumorigenic Growth.

Regulation of cellular actin dynamics is pivotal in driving cell motility. During cancer development, cells migrate to invade and spread; therefore, dysregulation of actin regulators is often associated with cancer progression. Here we report the role of ABRACL, a human homolog of the Dictyostelium actin regulator Costars, in migration and tumorigenic growth of cancer cells. We found a correlation between ABRACL expression and the migratory ability of cancer cells. Cell staining revealed the colocalization of ABRACL and F-actin signals at the leading edge of migrating cells. Analysis of the relative F-/G-actin contents in cells lacking or overexpressing ABRACL suggested that ABRACL promotes cellular actin distribution to the polymerized fraction. Physical interaction between ABRACL and cofilin was supported by immunofluorescence staining and proximity ligation. Additionally, ABRACL hindered cofilin-simulated pyrene F-actin fluorescence decay in vitro, indicating a functional interplay. Lastly, analysis on a colorectal cancer cohort demonstrated that high ABRACL expression was associated with distant metastasis, and further exploration showed that depletion of ABRACL expression in colon cancer cells resulted in reduced cell proliferation and tumorigenic growth. Together, results suggest that ABRACL modulates actin dynamics through its interaction with cofilin and thereby regulates cancer cell migration and participates in cancer pathogenesis.

Recombinant lipidated Zika virus envelope protein domain III elicits durable neutralizing antibody responses against Zika virus in mice.

BACKGROUND: The emergence of Zika virus (ZV) in tropical and subtropical areas of the world has created an urgent need for vaccines against ZV. However, approved vaccines that prevent ZV infection are not available. To develop an effective vaccine against ZV infection, a lipidated form of ZV envelope protein domain III that possesses an intrinsic adjuvant property was rationally designed. Our goal was to examine the immunogenicity of recombinant lipidated ZV envelope protein domain III (rLZE3) and evaluate its potential as a vaccine candidate against ZV. METHODS: Recombinant ZV envelope protein domain III (rZE3) and rLZE3 were prepared with an Escherichia coli-based system. Dendritic cell surface marker expression and cytokine production upon stimulation were analyzed to evaluate the function of rLZE3. Neutralizing antibody capacities were evaluated using focus reduction neutralization tests after immunization. To investigate the protective immunity in immunized mice, serum samples collected from immunized mice were adoptively transferred into AG129 mice, and then viremia levels and survival times were examined after ZV challenge. RESULTS: rLZE3 alone but not rZE3 alone efficiently activated dendritic cells in vitro and was taken up by dendritic cells in vivo. Immunization of C57BL/6 mice with rLZE3 alone (without exogenous adjuvant) could induce ZV-specific neutralizing antibody responses. Furthermore, serum samples obtained from rLZE3-immunized mice provided protection as indicated by a reduction in viremia levels and prolongation of survival times after ZV challenge. CONCLUSION: These results indicate that rLZE3 is an excellent vaccine candidate and has great potential that should be evaluated in further preclinical studies.

Mesenchymal stem cells tune the development of monocyte-derived dendritic cells toward a myeloid-derived suppressive phenotype through growth-regulated oncogene chemokines.

Mesenchymal stem/stromal cells (MSCs) are promising potential candidates for the treatment of immunological diseases because of their immunosuppressive functions. However, the molecular mechanisms that mediate MSCs' immunosuppressive activity remain elusive. In this article, we report for the first time, to our knowledge, that secreted growth-regulated oncogene (GRO) chemokines, specifically GRO-γ, in human MSC-conditioned media have an effect on the differentiation and the function of human monocyte-derived dendritic cells. The monocyte-derived dendritic cells were driven toward a myeloid-derived suppressor cell (MDSC)-like phenotype by the GRO chemokines. GRO-γ-treated MDSCs had a tolerogenic phenotype that was characterized by an increase in the secretion of IL-10 and IL-4, and a reduction in the production of IL-12 and IFN-γ. We have also shown that the mRNA expression levels of the arginase-1 and inducible NO synthase genes, which characterize MDSCs, were upregulated by GRO-γ-primed mouse bone marrow cells. In addition, the ability of GRO-γ-treated bone marrow-derived dendritic cells to stimulate the OVA-specific CD8(+) T (OT-1) cell proliferation and the cytokine production of IFN-γ and TNF-α were significantly decreased in vivo. Our findings allow a greater understanding of how MDSCs can be generated and offer new perspectives to exploit the potential of MDSCs for alternative approaches to treat chronic inflammation and autoimmunity, as well as for the prevention of transplant rejection.

Multiphoton imaging to identify grana, stroma thylakoid, and starch inside an intact leaf.

BACKGROUND: Grana and starch are major functional structures for photosynthesis and energy storage of plant, respectively. Both exhibit highly ordered molecular structures and appear as micrometer-sized granules inside chloroplasts. In order to distinguish grana and starch, we used multiphoton microscopy, with simultaneous acquisition of two-photon fluorescence (2PF) and second harmonic generation (SHG) signals. SHG is sensitive to crystallized structures while 2PF selectively reveals the distribution of chlorophyll. RESULT: Three distinct microstructures with different contrasts were observed, i.e. "SHG dominates", "2PF dominates", and "SHG collocated with 2PF". It is known that starch and grana both emit SHG due to their highly crystallized structures, and no autofluorescence is emitted from starch, so the "SHG dominates" contrast should correspond to starch. The contrast of "SHG collocated with 2PF" is assigned to be grana, which exhibit crystallized structure with autofluorescent chlorophyll. The "2PF dominates" contrast should correspond to stroma thylakoid, which is a non-packed membrane structure with chrolophyll. The contrast assignment is further supported by fluorescence lifetime measurement. CONCLUSION: We have demonstrated a straightforward and noninvasive method to identify the distribution of grana and starch within an intact leaf. By merging the 2PF and SHG images, grana, starch and stroma thylakoid can be visually distinguished. This approach can be extended to the observation of 3D grana distribution and their dynamics in living plants.

CD4+ T cells disarm or delete cytotoxic T lymphocytes under IL-17-polarizing conditions.

Previous studies have shown that TGF-ß acts cooperatively with IL-6 to elicit a high frequency of IL-17-secreting CD4(+) T cells (termed Th17) and an elevated CD8(+)IL-17(+) T cell population (termed Tc17). These CD8(+) cells fail to behave like most cytotoxic T lymphocytes that express IFN-γ and granzyme B, but they exhibit a noncytotoxic phenotype. Although a significant increase in the number of these Tc17 cells was found in tumors, their role and interaction with other cell types remain unclear. In this study, we demonstrate that the presence of CD4(+)CD25(-) T cells, but not the CD4(+)CD25(+) (regulatory T [Treg]) cell population, significantly reduced the elicitation of Tc17 cells, possibly as a result of the induction of apoptotic signals. Importantly, these signals may be derived from soluble mediators, and the addition of anti-IL-2 restored the reduction of Tc17 cells in the presence of CD4(+)CD25(-) T cells. Finally, the elicited Tc17 and Treg cells exhibited a close association in patients with head and neck cancer, indicating that the surrounding Treg cells might maintain the survival of the Tc17 cells. Taken together, these results reveal an intriguing mechanism in which Tc17 cells are controlled by a finely tuned collaboration between the different types of CD4(+) T cells in distinct tumor microenvironments.

Hepatitis B screening practice among older Chinese in the Greater Washington, DC, area.

OBJECTIVES: Older Chinese Americans are at greater risk of contracting hepatitis B virus (HBV) because they were born before the implementation of universal childhood vaccination policies. This study examined the prevalence of HBV screening, test results, and predictors of HBV screening among older Chinese. METHODS: Two hundred fifty-two Chinese immigrants (older than 50 years) recruited from Chinese-speaking physicians' offices in the Washington, DC, area participated in a cancer screening questionnaire. Descriptive statistics and hierarchical logistic regressions were conducted. RESULTS: Among the 164 participants (65%) who underwent HBV screening, 66% reported that they were susceptible to HBV infection. Stronger self-care beliefs, longer US residency, lower HBV knowledge, and lack of physician recommendations were independently and negatively associated with HBV screening. CONCLUSIONS: Many older Chinese did not adhere to HBV screening guidelines because of cultural views and information deficiency. Culturally appropriate interventions aimed to enhance their knowledge and communication with physicians about HBV are needed for promoting screening.

Target of rapamycin complex 2 signals to downstream effector yeast protein kinase 2 (Ypk2) through adheres-voraciously-to-target-of-rapamycin-2 protein 1 (Avo1) in Saccharomyces cerevisiae.

The conserved Ser/Thr kinase target of rapamycin (TOR) serves as a central regulator in controlling cell growth-related functions. There exist two distinct TOR complexes, TORC1 and TORC2, each coupling to specific downstream effectors and signaling pathways. In Saccharomyces cerevisiae, TORC2 is involved in regulating actin organization and maintaining cell wall integrity. Ypk2 (yeast protein kinase 2), a member of the cAMP-dependent, cGMP-dependent, and PKC (AGC) kinase family, is a TORC2 substrate known to participate in actin and cell wall regulation. Employing avo3(ts) mutants with defects in TORC2 functions that are suppressible by active Ypk2, we investigated the molecular interactions involved in mediating TORC2 signaling to Ypk2. GST pulldown assays in yeast lysates demonstrated physical interactions between Ypk2 and components of TORC2. In vitro binding assays revealed that Avo1 directly binds to Ypk2. In avo3(ts) mutants, the TORC2-Ypk2 interaction was reduced and could be restored by AVO1 overexpression, highlighting the important role of Avo1 in coupling TORC2 to Ypk2. The interaction was mapped to an internal region (amino acids 600-840) of Avo1 and a C-terminal region of Ypk2. Ypk2(334-677), a truncated form of Ypk2 containing the Avo1-interacting region, was able to interfere with Avo1-Ypk2 interaction in vitro. Overexpressing Ypk2(334-677) in yeast cells resulted in a perturbation of TORC2 functions, causing defective cell wall integrity, aberrant actin organization, and diminished TORC2-dependent Ypk2 phosphorylation evidenced by the loss of an electrophoretic mobility shift. Together, our data support the conclusion that the direct Avo1-Ypk2 interaction is crucial for TORC2 signaling to the downstream Ypk2 pathway.

The matricellular protein CCN1 suppresses lung cancer cell growth by inducing senescence via the p53/p21 pathway.

CCN1, a secreted matrix-associated molecule, is involved in multiple cellular processes. Previous studies have indicated that expression of CCN1 correlates inversely with the aggressiveness of non-small-cell lung carcinoma (NSCLC); however, the underlying mechanisms remain elusive. Using three NSCLC cell line systems, here we show that long-term treatment of cells with the recombinant CCN1 protein led to a permanent cell cycle arrest in G1 phase; cells remained viable as judged by apoptotic assays. CCN1-treated NSCLC cells acquired a phenotype characteristic of senescent cells, including an enlarged and flattened cell shape and expression of the senescence-associated ß-galactosidase. Immunoblot analysis showed that addition of CCN1 increased the abundance of hypo-phosphorylated Rb, as well as accumulation of p53 and p21. Silencing the expression of p53 or p21 by lentivirus-mediated shRNA production in cells blocked the CCN1-induced senescence. Furthermore, a CCN1 mutant defective for binding integrin α6ß1 and co-receptor heparan sulfate proteoglycans was incapable of senescence induction. Our finding that direct addition of CCN1 induces senescence in NSCLC cells provides a potential novel strategy for therapeutic intervention of lung cancers.

A novel anti-CCN1 monoclonal antibody suppresses Rac-dependent cytoskeletal reorganization and migratory activities in breast cancer cells.

CCN1, a secreted matrix-associated molecule, is involved in multiple cellular processes. Accumulating evidence supports that CCN1 plays an important role in tumorigenesis and progression of breast cancer. In this study, we have developed a novel CCN1 function-blocking monoclonal antibody (mAb), designated YM1B. YM1B binds to human CCN1 with high specificity, recognizing the native CCN1 structure with undisturbed disulfide linkages. Our analyses have mapped the YM1B recognition region to domain IV of CCN1, likely in proximity to the DM site. In breast cancer cells, CCN1 can induce actin reorganization, formation of lamellipodia, and cell migration/invasion through the αV integrins/Rac1/ERK signaling axis; these CCN1-dependent activities can be effectively suppressed by YM1B. Our results also suggest that YM1B may exert its CCN1-blocking effect by perturbing the interaction of CCN1 with vitronectin and fibronectin, which are ligands of αV integrins and instrumental for integrin activation. This CCN1-specific mAb may open a new potential avenue for therapeutic intervention of breast cancer progression.

A consensus envelope protein domain III can induce neutralizing antibody responses against serotype 2 of dengue virus in non-human primates.

We have previously demonstrated that vaccination with a subunit dengue vaccine containing a consensus envelope domain III with aluminum phosphate elicits neutralizing antibodies against all four serotypes of dengue virus in mice. In this study, we evaluated the immunogenicity of the subunit dengue vaccine in non-human primates. After vaccination, monkeys that received the subunit vaccine with aluminum phosphate developed a significantly strong and long-lasting antibody response. A specific T cell response with cytokine production was also induced, and this correlated with the antibody response. Additionally, neutralizing antibodies against serotype 2 were detected in two of three monkeys. The increase in serotype-2-specific antibody titers and avidity observed in these two monkeys suggested that a serotype-2-biased antibody response occurs. These data provide evidence that a protective neutralizing antibody response was successfully elicited in non-human primates by the dengue subunit vaccine with aluminum phosphate adjuvant.

Luteolin-Loaded Nanoparticles for the Treatment of Melanoma.

Background and Purpose: Luteolin (LUT), a flavonoid found in various plants, has been reported to have potential therapeutic effects in melanoma. However, poor water solubility and low bioactivity have severely restricted the clinical application of LUT. Based on the high reactive oxygen species (ROS) levels in melanoma cells, we developed nanoparticles encapsulating LUT with the ROS-responsive material poly(propylene sulfide)-poly(ethylene glycol) (PPS-PEG) to enhance the water solubility of LUT, accelerate the release of LUT in melanoma cells, and further enhance its anti-melanoma effect, providing a viable solution for the application of LUT nano-delivery systems in melanoma therapy. Methods: In this study, LUT-loaded nanoparticles were prepared with PPS-PEG and named as LUT-PPS-NPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were applied to determine the size and morphology of LUT-PPS-NPs. In vitro studies were carried out to determine the uptake and mechanism of LUT-PPS-NPs by SK-MEL-28 melanoma cells. According to the CCK-8 assay, the cytotoxic effects of LUT-PPS-NPs on human skin fibroblasts (HSF) and SK-MEL-28 cells were assessed. Apoptosis assays, cell migration and invasion assays, and proliferation inhibition assays with low and normal density plating were also applied to test the in vitro anti-melanoma effect. Additionally, melanoma models were established utilizing BALB/c nude mice and initially evaluated the growth inhibitory impact following intratumoral injection of LUT-PPS-NPs. Results: The size of LUT-PPS-NPs was 169.77 ± 7.33 nm with high drug loading (15.05 ± 0.07%). In vitro, cellular assays confirmed that LUT-PPS-NPs were efficiently internalized by SK-MEL-28 cells and showed low cytotoxicity against HSF. Moreover, LUT released from LUT-PPS-NPs significantly inhibited tumor cell proliferation, migration and invasion. Animal experiments showed that LUT-PPS-NPs inhibited tumor growth more than 2-fold compared with the LUT group. Conclusion: In conclusion, the LUT-PPS-NPs developed in our study enhanced the anti-melanoma effect of LUT.

Defect-Rich SnO2 Nanofiber as an Oxygen-Defect-Driven Photoenergy Shield against UV Light Cell Damage.

Usually, most studies focus on toxic gas and photosensors by using electrospinning and metal oxide polycrystalline SnO2 nanofibers (PNFs), while fewer studies discuss cell-material interactions and photoelectric effect. In this work, the controllable surface morphology and oxygen defect (VO) structure properties were provided to show the opportunity of metal oxide PNFs to convert photoenergy into bio-energy for bio-material applications. Using the photobiomodulation effect of defect-rich polycrystalline SnO2 nanofibers (PNFs) is the main idea to modulate the cell-material interactions, such as adhesion, growth direction, and reactive oxygen species (ROS) density. The VO structures, including out-of-plane oxygen defects (op-VO), bridge oxygen defects (b-VO), and in-plane oxygen defects (ip-VO), were studied using synchrotron analysis to investigate the electron transfer between the VO structures and conduction bands. These intragrain VO structures can be treated as generation-recombination centers, which can convert various photoenergies (365-520 nm) into different current levels that form distinct surface potential levels; this is referred to as the photoelectric effect. PNF conductivity was enhanced 53.6-fold by enlarging the grain size (410 nm2) by increasing the annealing temperature, which can improve the photoelectric effect. In vitro removal of reactive oxygen species (ROS) can be achieved by using the photoelectric effect of PNFs. Also, the viability and shape of human bone marrow mesenchymal stem cells (hMSCs-BM) were also influenced significantly by the photobiomodulation effect. The cell damage and survival rate can be prevented and enhanced by using PNFs; metal oxide nanofibers are no longer only environmental sensors but can also be a bio-material to convert the photoenergy into bio-energy for biomedical science applications.

Novel GdTaO4 phase for efficient photocatalytic degradation of organic dye under visible light irradiation: An X-ray spectroscopic investigation.

The novel GdTaO4 phase exhibits good photocatalytic activity under visible light irradiation and holds great promise for the removal of organic dyes from industrial wastes. The GdTaO4 samples were synthesized using the hydrothermal and calcination process with different weight ratios of gadolinium nitrate hydrate (G) and tantalum pentachloride (T), and their structural studies confirmed the formation of the GdTaO4 (GT) phase. Among the samples, GT-4 (with a weight ratio of 4:1) exhibited the highest photocatalytic activity for the degradation of Methyl Orange (MO) dye under visible light irradiation. To enhance the photocatalytic performance, H2O2 was used as a green additive, and the photocatalytic abilities were examined by varying dye types and concentrations. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) revealed the local atomic and electronic structures around Ta and Gd and highlighted the contribution of Gd3+ to the GT system, which is a crucial factor in supporting the enhanced photocatalytic performance. Moreover, in-situ XAS at Gd M5-edge and O K-edge were examined under illumination/dark conditions to explore the electronic structures of photo-excited electron transition in the photocatalytic process. The analytical results provided strong evidence correlating the electronic structure and photocatalytic property of the GT. This study demonstrates that GdTaO4 exhibits good photocatalytic activity under visible light irradiation, making it a promising new Ta-based photocatalyst for the effective removal of organic dyes from industrial wastes.

SnO2-Based Ultra-Flexible Humidity/Respiratory Sensor for Analysis of Human Breath.

Developing ultraflexible sensors using metal oxides is challenging due to the high-temperature annealing step in the fabrication process. Here, we demonstrate the ultraflexible relative humidity (RH) sensor on food plastic wrap by using 808 nm near-infrared (NIR) laser annealing for 1 min at a low temperature (26.2-40.8 °C). The wettability of plastic wraps coated with sol-gel solution is modulated to obtain uniform films. The surface morphology, local temperature, and electrical properties of the SnO2 resistor under NIR laser irradiation with a power of 16, 33, and 84 W/cm2 are investigated. The optimal device can detect wide-range RH from 15% to 70% with small incremental changes (0.1-2.2%). X-ray photoelectron spectroscopy reveals the relation between the surface binding condition and sensing response. Finally, the proposed sensor is attached onto the face mask to analyze the real-time human breath pattern in slow, normal, and fast modes, showing potential in wearable electronics or respiration monitoring.

Correction: DNA vaccination induced protective immunity against SARS CoV-2 infection in hamsterss.

[This corrects the article DOI: 10.1371/journal.pntd.0009374.].