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1.
Acta Psychol (Amst) ; 246: 104264, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38626597

ABSTRACT

DESIGN/METHODOLOGY/APPROACH: This article employs qualitative thematic modeling to gather insights from 30 informants. The study explores various aspects related to the impact of the COVID-19 pandemic on AI ChatGPT technologies. PURPOSE: The purpose of this research is to examine how the COVID-19 pandemic has influenced the increased usage and adoption of AI ChatGPT. It aims to explore the pandemic's impact on AI ChatGPT and its applications in specific domains, as well as the challenges and opportunities it presents. FINDINGS: The findings highlight that the pandemic has led to a surge in online activities, resulting in a heightened demand for AI ChatGPT. It has been widely used in areas such as healthcare, mental health support, remote collaboration, and personalized customer experiences. The article showcases examples of AI ChatGPT's application during the pandemic. STRENGTH OF STUDY: This qualitative framework enables the study to delve deeply into the multifaceted dimensions of AI ChatGPT's role during the pandemic, capturing the diverse experiences and insights of users, practitioners, and experts. By embracing the qualitative nature of inquiry and this research offers a comprehensive understanding of the challenges, opportunities, and ethical considerations associated with the adoption and utilization of AI ChatGPT in crisis contexts. PRACTICAL IMPLICATIONS: The insights from this research have practical implications for policymakers, developers, and researchers. This reserach emphasize the need for responsible and ethical implementation of AI ChatGPT to fully harness its potential in addressing societal needs during and beyond the pandemic. SOCIAL IMPLICATIONS: The increased reliance on AI ChatGPT during the pandemic has led to changes in user behavior, expectations, and interactions. However, it has also unveiled ethical considerations and potential risks. Addressing societal and ethical concerns, such as user impact and autonomy, privacy and security, bias and fairness, and transparency and accountability, is crucial for the responsible deployment of AI ChatGPT. ORIGINALITY/VALUE: This research contributes to the understanding of the novel role of AI ChatGPT in times of crisis, particularly in the era of COVID-19 pandemic. It highlights the necessity of responsible and ethical implementation of AI ChatGPT and provides valuable insights for the development and application of AI technology in the future.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Artificial Intelligence , Qualitative Research , Telemedicine , Pandemics , SARS-CoV-2
2.
Acta Psychol (Amst) ; 242: 104113, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38171191

ABSTRACT

PURPOSE: This research article aims to assess the behavior of tourists in sustainable rural mountain tourism during the COVID-19 pandemic, focusing on the role of social media usage. It investigates the key social media features that influence tourist behavior and introduces the concept of perceived risk as a novel variable within the Technology Acceptance Model (TAM) to deepen our understanding of the relationship between social media use and tourist behavior. DESIGN/METHODOLOGY/APPROACH: The study conducts an extensive literature review and utilizes survey analysis. Three parameters-perception of risk, perception of value, and trust in social media-are employed to measure the impact of influential social media features. Statistical tests are applied to validate the new variable of perceived risk within the TAM. FINDINGS: The study unveils that tourists' perception of risk associated with social media has the most significant influence on their behavior in rural mountain tourism during the pandemic. Additionally, it identifies that active engagement of tourists in online discussions positively affects both tourist behavior and social media usage, emphasizing the importance of community participation. RESEARCH LIMITATIONS/IMPLICATIONS: The research acknowledges limitations, including the need for further validation of the perceived risk variable and the consideration of contextual influences. Future studies should explore additional variables and encompass diverse tourist populations to expand the understanding of social media usage and tourist behavior in rural mountain regions. CONTRIBUTION OF RESEARCH: This research significantly advances the understanding of tourist behavior in sustainable rural mountain tourism during the COVID-19 pandemic by introducing the novel variable of "perceived risk" within the Technology Acceptance Model. The study identifies influential social media features and underscores the positive effects of participatory habits, providing valuable insights for promoting sustainable tourism through targeted social media interventions. PRACTICAL IMPLICATIONS: This research holds significant practical implications for practitioners and policymakers seeking to promote sustainable tourism in rural mountain regions, particularly during the COVID-19 pandemic. The identification of influential social media features and the emphasis on participatory habits among tourists offer actionable insights. Practitioners can leverage these findings to design targeted social media interventions that foster community engagement and enhance tourists' perception of value while mitigating perceived risks. Policymakers can use this information to shape strategies that encourage interactive online platforms, creating a sense of community participation to boost sustainable tourism.


Subject(s)
COVID-19 , Social Media , Humans , Community Participation , COVID-19/epidemiology , Pandemics , Tourism
3.
Acta Psychol (Amst) ; 240: 104050, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37832493

ABSTRACT

This study employs a qualitative research methodology to comprehensively investigate the psychological resilience of athletes impacted by the COVID-19 pandemic. Through purposeful sampling, a diverse group of athletes representing various sports, competitive levels, and geographic locations was selected, ensuring a holistic exploration of their experiences. Data collection centered on in-depth interviews, utilizing a semi-structured approach guided by predetermined open-ended questions. Ethical standards were meticulously upheld, with informed consent obtained from all participants, and strict measures in place to safeguard their confidentiality and anonymity. Prior to data collection, pilot testing of interview questions was conducted to enhance their clarity and appropriateness. Subsequently, data analysis involved the meticulous transcription of field-notes and audio-recordings into protocols and transcripts, followed by systematic coding facilitated by qualitative data management software. To enhance research rigor, strategies including reflexivity, member-checking, and collaborative coding were embraced. This comprehensive methodology facilitated a deep and nuanced exploration of athletes' experiences, perceptions, and coping strategies during the pandemic, ultimately contributing valuable insights to the study of psychological resilience in sports. The findings shed light on the challenges athletes faced, the support systems and personal attributes that fostered resilience, and the role of well-being practices like mindfulness and self-care in enhancing psychological resilience. The implications of this research extend to proactive strategies for sports organizations and stakeholders, fostering a culture of resilience, and empowering athletes to thrive in the face of adversity, ultimately promoting their long-term psychological well-being.


Subject(s)
COVID-19 , Resilience, Psychological , Humans , Pandemics , COVID-19/epidemiology , Athletes/psychology , Adaptation, Psychological
4.
Cancer Lett ; 537: 215667, 2022 07 01.
Article in English | MEDLINE | ID: mdl-35398531

ABSTRACT

Formation of the premetastatic niche is triggered by primary tumors and contributes to cancer metastasis. Evidence indicating the roles of macrophages in metastatic niche formation and organ-specific metastatic tropism has been steadily accumulating. However, the role of tissue-resident macrophages in the establishment of the premetastatic niche is not clearly defined. Here, we report that alveolar macrophages (AMs), which are lung tissue-resident macrophages, play a critical role in initiating the recruitment of monocytic myeloid-derived suppressor cells (mo-MDSCs) and the subsequent premetastatic niche formation by increasing CCL12 expression. We found that CXCL10 can induce CCL12 expression by activating CXCR3 and TLR4 in AMs. CXCR3/TLR4 deficiency or inhibition of its activity reduces CCL12 expression in AMs and subsequent mo-MDSC recruitment to the premetastatic niche, thereby attenuating lung metastasis. In addition, Ube2o is a negative modulator of CXCL10-induced CCL12 expression. Downregulation of Ube2o in AMs under tumor conditions enhances TAK1-NF-κB/ERK/JNK signaling and CXCL10-induced CCL12 expression by promoting TRAF6 polyubiquitination and inhibiting DDX3X degradation. Targeting mo-MDSC recruitment via the CXCL10-CXCR3/TLR4-CCL12 axis in AMs may have therapeutic potential for suppressing lung metastasis.


Subject(s)
Lung Neoplasms , Myeloid-Derived Suppressor Cells , Chemokine CXCL10/metabolism , Humans , Lung/pathology , Lung Neoplasms/metabolism , Macrophages, Alveolar/pathology , Myeloid-Derived Suppressor Cells/metabolism , Neoplasm Metastasis/pathology , Toll-Like Receptor 4/metabolism , Ubiquitin-Conjugating Enzymes/metabolism
5.
Cell Death Dis ; 13(1): 36, 2022 01 10.
Article in English | MEDLINE | ID: mdl-35013108

ABSTRACT

Tumors modify myeloid cell differentiation and induce an immunosuppressive microenvironment. Granulocytic myeloid-derived suppressor cells (G-MDSCs), the main subgroup of myeloid-derived suppressor cells (MDSCs), are immature myeloid cells (IMCs) with immunosuppressive activity and exist in tumor-bearing hosts. The reason why these cells diverge from a normal differentiation pathway and are shaped into immunosuppressive cells remains unclear. Here, we reported that the increase of granulocyte colony-stimulating factor (G-CSF) in mouse serum with tumor progression encouraged G-MDSCs to obtain immunosuppressive traits in peripheral blood through the PI3K-Akt/mTOR pathway. Importantly, we found that downregulation of type I interferon (IFN-I) signaling in G-MDSCs was a prerequisite for their immunosuppressive effects. Suppressor of cytokine signaling (SOCS1), the action of which is dependent on IFN-I signaling, inhibited the activation of the PI3K-Akt/mTOR pathway by directly interacting with Akt, indicating that the differentiation of immunosuppressive G-MDSCs involves a transition from immune activation to immune tolerance. Our study suggests that increasing IFN-I signaling in G-MDSCs may be a strategy for reprograming immunosuppressive myelopoiesis and slowing tumor progression.


Subject(s)
Immune Tolerance , Interferon Type I/metabolism , Myeloid-Derived Suppressor Cells/immunology , Neoplasms/immunology , Animals , Disease Progression , Granulocyte Colony-Stimulating Factor/metabolism , Mice , Myeloid-Derived Suppressor Cells/metabolism , Myeloid-Derived Suppressor Cells/pathology , Myelopoiesis , Neoplasms/metabolism , Neoplasms/pathology , Phosphatidylinositol 3-Kinase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction , Suppressor of Cytokine Signaling 1 Protein/metabolism , TOR Serine-Threonine Kinases , Tumor Escape , Tumor Microenvironment/immunology
6.
Front Psychiatry ; 12: 643783, 2021.
Article in English | MEDLINE | ID: mdl-34539457

ABSTRACT

This present study primarily emphasizes to seek the COVID-19 adverse impacts posing health challenges and global economic crisis. The pandemic (COVID-19) continues to hit the global economies adversely. Pakistan is the 5th-most-populous nation, and recorded positive cases with the third-highest positivity ratio in South Asia, and 26th-highest deaths toll of 21,450 and 29th number of most COVID-19 positive cases with 933,750 worldwide, as of June 6, 2021. The first wave appeared at the end of May 2020, and mid of June reported its peak, which ended by mid-July 2020. Early November 2020 witnessed the second wave with low intensity reached the climax by mid-December. The COVID-19's third wave severely affected the country during mid-March 2021. It exhibited the highest positivity rate, around 20%. New positive patients and deaths toll commenced to skyrocket and reported peak by April 15, 2021. Then situation gradually improved with effective measures and restrictions. The pandemic coronavirus (COVID-19) has affected 220 territories, regions, and countries and resulted in more than 174.116 million infections, deaths, 3.75 million, and 157.157 million positive cases fully recovered from this infectious disease, as of June 7, 2021. The pandemic has caused a severe crisis of healthcare facilities and economic challenges worldwide. Pakistani economy reported GPD's negative growth (-0.05) for the first time over the last 60 years in 2020, which caused a massive financial crisis. The Government's relief package intervened to reduce public mental stress and improve the quality of their lives. IMF reported that Pakistan's GPD bounced back at 4% growth by June 2021. This article determines that economic instability and health burden happened in Pakistan for a longer time than financial disequilibrium that occurred globally. Pakistan encountered this crisis due to its feeble healthcare systems and fragile economy. This study explores adverse health issues and spillover consequences on the economic crisis in Pakistan with global implications. It recommends smart lockdown restrictions in most affected areas to reopen the economic cycle with strict preventive measures to minimize the COVD-19 adverse consequences.

7.
Mol Nutr Food Res ; 65(15): e2100096, 2021 08.
Article in English | MEDLINE | ID: mdl-34061433

ABSTRACT

SCOPE: The beneficial effects of probiotics in reducing gastrointestinal inflammation and in preventing colorectal cancer have been reported, but the mechanism underlying the immunomodulatory effect of probiotics in inhibiting extra-intestinal tumor progression remains unclear. METHODS AND RESULTS: This study shows that probiotic supplementation attenuate lung metastasis of melanoma cells in mice. Feeding mice with VSL#3 probiotics change the composition and proportion of gut microbiota. The changes in gut bacteria composition, such as in the abundance of Lachnospiraceae, Streptococcus, and Lachnoclostridium, are associated with the production of short-chain fatty acids in the gut. The concentrations of propionate and butyrate are upregulated in gut and blood after feeding VSL#3, and the increase in propionate and butyrate levels promotes the expression of chemokine (C-C motif) ligand 20 (CCL20) in lung endothelial cells and the recruitment of T helper 17 (Th17) cells to the lungs via the CCL20/chemokine receptor 6 axis. The recruitment of Th17 cells decreases the number of tumor foci in lungs and attenuates the lung metastasis of melanoma cells in mice. CONCLUSIONS: The results provide new information on the role and mechanisms of action of probiotics in attenuating extra-intestinal tumor metastasis.


Subject(s)
Butyrates/metabolism , Lung Neoplasms/secondary , Melanoma, Experimental/pathology , Probiotics/pharmacology , Propionates/metabolism , Animals , Chemokine CCL20/metabolism , Dietary Supplements , Endothelial Cells/metabolism , Endothelial Cells/pathology , Fatty Acids, Volatile/metabolism , Gastrointestinal Microbiome/physiology , Lung Neoplasms/diet therapy , Lung Neoplasms/pathology , Mice, Inbred C57BL , Th17 Cells
8.
Risk Manag Healthc Policy ; 14: 1917-1932, 2021.
Article in English | MEDLINE | ID: mdl-34012304

ABSTRACT

BACKGROUND: This study focuses on how educating people through social media platforms can help reduce the mental health consequences of the COVID-19 to manage the global health crisis. The pandemic has posed a global mental health crisis, and correct information is indispensable to dispel uncertainty, fear, and mental stress to unify global communities in collective combat against COVID-19 disease worldwide. Mounting studies specified that manifestly endless coronavirus-related newsfeeds and death numbers considerably increased the risk of global mental health issues. Social media provided positive and negative data, and the COVID-19 has resulted in a worldwide infodemic. It has eroded public trust and impeded virus restraint, which outlived the coronavirus pandemic itself. METHODS: The study incorporated the narrative review analysis based on the existing literature related to mental health problems using the non-pharmaceutical interventions (NPIs) approach to minimize the COVID-19 adverse consequences on global mental health. The study performed a search of the electronic databases available at PsycINFO, PubMed, and LISTA. This research incorporates the statistical data related to the COVID-19 provided by the WHO, John Hopkins University, and Pakistani Ministry of Health. RESULTS: Pakistan reported the second-highest COVID-19 cases within South Asia, the fifth-highest number of cases in Asia after Iran, India, Russia, Saudi Arabia, and the 14th highest recorded cases, as of October 14, 2020. Pakistan effectively managed the COVID-19 pandemic in the second wave. It stands at the eighth-highest number of confirmed cases in Asia, the 3rd-highest in South Asia, and the 28th-highest number of established patients globally, as of February20, 2021. CONCLUSION: The COVID-19 has resulted in over 108.16 million confirmed cases, deaths over 2.374 million, and a recovery of 80.16 million people worldwide, as of February 12, 2021. This study focused on exploring the COVID-19 pandemic's adverse effects on global public health and the indispensable role of social media to provide the correct information in the COVID-19 health crisis. The findings' generalizability offers helpful insight for crisis management and contributes to the scientific literature. The results might provide a stepping-stone for conduct future empirical studies by including other factors to conclude exciting developments.

9.
Cell Death Dis ; 12(2): 202, 2021 02 19.
Article in English | MEDLINE | ID: mdl-33608512

ABSTRACT

Ring1b is a core subunit of polycomb repressive complex 1 (PRC1) and is essential in several high-risk cancers. However, the epigenetic mechanism of Ring1b underlying breast cancer malignancy is poorly understood. In this study, we showed increased expression of Ring1b promoted metastasis by weakening cell-cell adhesions of breast cancer cells. We confirmed that Ring1b could downregulate E-cadherin and contributed to an epigenetic rewiring via PRC1-dependent function by forming distinct complexes with DEAD-box RNA helicases (DDXs) or epithelial-mesenchymal transition transcription factors (EMT TFs) on site-specific loci of E-cadherin promoter. DDXs-Ring1b complexes moderately inhibited E-cadherin, which resulted in an early hybrid EMT state of epithelial cells, and EMT TFs-Ring1b complexes cooperated with DDXs-Ring1b complexes to further repress E-cadherin in mesenchymal-like cancer cells. Clinically, high expression of Ring1b with DDXs or EMT TFs predicted low levels of E-cadherin, metastatic behavior, and poor prognosis. These findings provide an epigenetic regulation mechanism of Ring1b complexes in E-cadherin expression. Ring1b complexes may be potential therapeutic targets and biomarkers for diagnosis and prognosis in invasion breast cancer.


Subject(s)
Antigens, CD/genetics , Breast Neoplasms/enzymology , Cadherins/genetics , DEAD-box RNA Helicases/metabolism , Epithelial-Mesenchymal Transition , Gene Silencing , Polycomb Repressive Complex 1/metabolism , Repressor Proteins/metabolism , Snail Family Transcription Factors/metabolism , Twist-Related Protein 1/metabolism , Animals , Antigens, CD/metabolism , Binding Sites , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cadherins/metabolism , Cell Movement , DEAD-box RNA Helicases/genetics , Female , Gene Expression Regulation, Neoplastic , HEK293 Cells , Humans , MCF-7 Cells , Mice, Inbred BALB C , Mice, Nude , Neoplasm Invasiveness , Polycomb Repressive Complex 1/genetics , Prognosis , Promoter Regions, Genetic , Repressor Proteins/genetics , Snail Family Transcription Factors/genetics , Twist-Related Protein 1/genetics
10.
Anal Methods ; 13(6): 789-795, 2021 02 19.
Article in English | MEDLINE | ID: mdl-33496288

ABSTRACT

Fluorescent carbon dots derived from natural biomass have received widespread attention in recent years due to their superior optical and chemical properties. In this work, we proposed a method to synthesize fluorescent nitrogen, sulfur, and phosphorus co-doped carbon dots (NSP-CDs) using biomass waste as a precursor. The blue emitting carbon dots were prepared from the seeds of green pepper, and Fe3+ ions could quench the fluorescence of NSP-CDs. Therefore, a fluorescent "turn-off" sensor based on NSP-CDs was constructed for the detection of Fe3+ ions. Further, NSP-CDs were evaluated as a fluorescent biosensor for the detection of Fe3+ in tap water and lake water samples, showing their potential value in practical applications. The cytotoxicity test further confirmed that NSP-CDs have good biocompatibility and can be extended to cell imaging and intracellular Fe3+ detection. The proposed method is simple, economical and green, which can meet the requirements of environmental monitoring and biological imaging.


Subject(s)
Carbon , Nitrogen , Biomass , Ions , Sulfur
11.
Front Psychol ; 12: 790923, 2021.
Article in English | MEDLINE | ID: mdl-35411208

ABSTRACT

The product market competition has become a global challenge for business organizations in the challenging and competitive market environment in the influx of the COVID-19 outbreak. The influence of products competition on organizational performance in developed economies has gained scholars' attention, and numerous studies explored its impacts on business profitability. The existing studies designate mixed findings between the linkage of CSR practices and Chinese business firms' healthier performance in emerging economies; however, the current global crisis due to the coronavirus has made product market completion fierce, which ultimately affects business firms' performance. This study focuses on this logical global challenge, investigates the rationale, and examines product-market completion impact on firms' performance operating in the Chinese markets. The study collected data from the annual reports of Chinese business organizations with A-share listing and registered with the database of China Stock Markets and Accounting Research (CSMAR). The study employed a Generalized Method of Moment technique and investigated the connection between product market competition and Chinese firm performance. The empirical analysis of this study highlights the conclusion that market competition positively and significantly affected business firms' performance. This study specified that product market competition play a dynamic and indispensable role in achieving healthier firm performance in the Chinese markets. This study provides valuable insights on practical implications and future research directions for the scholars to draw interesting results with new study models.

12.
Front Psychol ; 12: 769175, 2021.
Article in English | MEDLINE | ID: mdl-35465147

ABSTRACT

Technology innovation has changed the patterns with its advanced features for travel and tourism industry during the outbreak of COVID-19 pandemic, which massively hit tourism and travel worldwide. The profound adverse effects of the coronavirus disease resulted in a steep decline in the demand for travel and tourism activities worldwide. This study focused on the literature based on travel and tourism in the wake global crisis due to infectious virus. The study aims to review the emerging literature critically to help researchers better understand the situation. It valorizes transformational affordance, tourism, and travel industries impacts posed by the virus COVID-19. The study proposed a research model on reviving the international tourism activities post COVID-19 pandemic to gain sustainable development and recovery. The scholars have debated seeking the best possible ways to predict a sustainable recovery of travel, tourism, and leisure sectors from the devastating consequences of coronavirus COVID-19. In the first phase, the study describes how the current pandemic can become transformational opportunities. It debates the situation and questions related to the emergence of the COVID-19 outbreak. The present research focuses on identifying fundamental values, organizations, and pre-assumptions related to travel and tourism revival and help academia and researchers to a breakthrough in initiating the frontiers based on research and practice. This study aims at exploring the role of technological innovation in the crisis management of COVID-19 tourism impacts, tourists' behavior, and experiences. The travel and tourism industry's main stakeholders include tourism demand and organizations that manage tourists' destinations and policymakers. They have already experienced the stages of responses, recovery, and resetting tourism recovery strategies. The study provides valuable insight into the coronavirus consequences on travel and tourism and practical implications for global tourism and academic research revitalization.

13.
Mol Cells ; 43(9): 793-803, 2020 Sep 30.
Article in English | MEDLINE | ID: mdl-32863280

ABSTRACT

Myeloid-derived suppressor cells (MDSCs) promote tumour progression by contributing to angiogenesis, immunosuppression, and immunotherapy resistance. Although recent studies have shown that microRNAs (miRNAs) can promote the expansion of MDSCs in the tumour environment, the mechanisms involved in this process are largely unknown. Here, we report that microRNA 449c (miR-449c) expression was upregulated in myeloid progenitor cells upon activation of C-X-C motif chemokine receptor 2 (CXCR2) under tumour conditions. MiR-449c upregulation increased the generation of monocytic MDSCs (mo-MDSCs). The increased expression of miR-449c could target STAT6 mRNA in myeloid progenitor cells to shift the differentiation balance of myeloid progenitor cells and lead to an enhancement of the mo-MDSCs population in the tumour environment. Thus, our results demonstrate that the miR-449c/STAT6 axis is involved in the expansion of mo-MDSCs from myeloid progenitor cells upon activation of CXCR2, and thus, inhibition of miR-449c/STAT6 signalling may help to attenuate tumour progression.


Subject(s)
Melanoma, Experimental/metabolism , MicroRNAs/metabolism , Monocytes/metabolism , STAT6 Transcription Factor/metabolism , Animals , Female , HEK293 Cells , Humans , Melanoma, Experimental/genetics , Melanoma, Experimental/pathology , Mice , Mice, Inbred C57BL , MicroRNAs/biosynthesis , MicroRNAs/genetics , Monocytes/pathology , Myeloid-Derived Suppressor Cells/metabolism , Myeloid-Derived Suppressor Cells/pathology , STAT6 Transcription Factor/genetics
14.
Nucleic Acids Res ; 48(3): 1353-1371, 2020 02 20.
Article in English | MEDLINE | ID: mdl-31943071

ABSTRACT

The human apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3 (APOBEC3, A3) family member proteins can deaminate cytosines in single-strand (ss) DNA, which restricts human immunodeficiency virus type 1 (HIV-1), retrotransposons, and other viruses such as hepatitis B virus, but can cause a mutator phenotype in many cancers. While structural information exists for several A3 proteins, the precise details regarding deamination target selection are not fully understood. Here, we report the first parallel, comparative analysis of site selection of A3 deamination using six of the seven purified A3 member enzymes, oligonucleotides having 5'TC3' or 5'CT3' dinucleotide target sites, and different flanking bases within diverse DNA secondary structures. A3A, A3F and A3H were observed to have strong preferences toward the TC target flanked by A or T, while all examined A3 proteins did not show a preference for a TC target flanked by a G. We observed that the TC target was strongly preferred in ssDNA regions rather than dsDNA, loop or bulge regions, with flanking bases influencing the degree of preference. CT was also shown to be a potential deamination target. Taken together, our observations provide new insights into A3 enzyme target site selection and how A3 mutagenesis impacts mutation rates.


Subject(s)
Cytidine Deaminase/genetics , DNA, Single-Stranded/genetics , DNA-Binding Proteins/genetics , Deamination/genetics , APOBEC Deaminases , Binding Sites/genetics , Cell Line , Cytidine Deaminase/chemistry , Cytosine Deaminase/chemistry , Cytosine Deaminase/genetics , DNA, Single-Stranded/chemistry , DNA-Binding Proteins/chemistry , HIV-1/genetics , HIV-1/pathogenicity , Hepatitis B virus/genetics , Humans , Mutagenesis/genetics , Nucleic Acid Conformation , Protein Structure, Secondary , Retroelements/genetics
15.
Cell Death Dis ; 10(9): 641, 2019 Sep 05.
Article in English | MEDLINE | ID: mdl-31488810

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

16.
Cell Death Dis ; 10(8): 598, 2019 08 08.
Article in English | MEDLINE | ID: mdl-31395859

ABSTRACT

Myeloid-derived suppressor cells (MDSCs) comprise a critical component of the tumor environment and CXCR2 reportedly plays a key role in the pathophysiology of various inflammatory diseases. Here, CXCR2 expression on granulocyte and macrophage progenitor cells (GMPs) was found to participate in myeloid cell differentiation within the tumor environment. In CXCR2-deficient tumor-bearing mice, GMPs exhibited fewer macrophage and dendritic cell progenitor cells than wild-type tumor-bearing mice, thereby decreasing monocytic MDSCs (mo-MDSCs) expansion. CXCR2 deficiency increased SAP18 expression in tumor-bearing mice, which reduced STAT3 phosphorylation through restraining ERK1/2 activation. Our findings reveal a critical role for CXCR2 in regulating hematopoietic progenitor cell differentiation under tumor conditions, and SAP18 is a key negative regulator in this process. Thus, inhibiting CXCR2 expression may alter the tumor microenvironment and attenuate tumor progression.


Subject(s)
Co-Repressor Proteins/genetics , Granulocyte-Macrophage Progenitor Cells/metabolism , Melanoma, Experimental/genetics , RNA-Binding Proteins/genetics , Receptors, Interleukin-8B/genetics , STAT3 Transcription Factor/genetics , Animals , Cell Line, Tumor , Gene Expression Regulation, Neoplastic/genetics , Granulocyte-Macrophage Progenitor Cells/pathology , Humans , MAP Kinase Signaling System/genetics , Melanoma, Experimental/pathology , Mice , Monocytes/metabolism , Monocytes/pathology , Myeloid-Derived Suppressor Cells/metabolism , Myeloid-Derived Suppressor Cells/pathology , RNA, Small Interfering/pharmacology , Receptors, Interleukin-8B/antagonists & inhibitors , Tumor Microenvironment/genetics
17.
Nano Lett ; 18(2): 957-963, 2018 02 14.
Article in English | MEDLINE | ID: mdl-29376383

ABSTRACT

Active tunability of photonic resonances is of great interest for various applications such as optical switching and modulation based on optoelectronic materials. Manipulation of charged excitons in atomically thin transition metal dichalcogenides (TMDCs) like monolayer MoS2 offers an unexplored route for diverse functionalities in optoelectronic nanodevices. Here, we experimentally demonstrate the dynamic photochemical and optoelectronic control of the photonic crystal Fano resonances by optical and electrical tuning of monolayer MoS2 refractive index via trions without any chemical treatment. The strong spatial and spectral overlap between the photonic Fano mode and the active MoS2 monolayer enables efficient modulation of the Fano resonance. Our approach offers new directions for potential applications in the development of optical modulators based on emerging 2D direct band gap semiconductors.

18.
Nano Lett ; 17(11): 6715-6720, 2017 11 08.
Article in English | MEDLINE | ID: mdl-28991494

ABSTRACT

Atomically thin transition metal dichalcogenides like MoS2 monolayers exhibit unique luminescent properties. However, weak quantum yield and low light absorption hinder their practical applications in two-dimensional light emitting devices. Here, we report 1300 times enhancement in photoluminescence emission from a MoS2 monolayer via simultaneous Fano resonances in a dielectric photonic crystal. The spatially extended double Fano resonance scheme allows resonant enhancement of both the MoS2 absorption and emission. We also achieve unidirectional emission within a narrow divergence angle of 5° by engineering the Fano resonance angular dispersion. Our approach provides a new platform for efficient light sources with high directionality based on emerging two-dimensional materials.

19.
Nanoscale Res Lett ; 10(1): 409, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26474890

ABSTRACT

Titanium oxyhydroxy-fluoride, TiO0.9(OH)0.9F1.2 · 0.59H2O rods with a hexagonal tungsten bronze (HTB) structure, was synthesized via a facile one-step solvothermal method. The structure, morphology, and component of the products were characterized by X-ray powder diffraction (XRD), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), ion chromatograph, energy-dispersive X-ray (EDX) analyses, and so on. Different rod morphologies which ranged from nanoscale to submicron scale were simply obtained by adjusting reaction conditions. With one-dimension channels for Li/Na intercalation/de-intercalation, the electrochemical performance of titanium oxyhydroxy-fluoride for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) was also studied. Electrochemical tests revealed that, for LIBs, titanium oxyhydroxy-fluoride exhibited a stabilized reversible capacity of 200 mAh g(-1) at 25 mA g(-1) up to 120 cycles in the electrode potential range of 3.0-1.2 V and 140 mAh g(-1) at 250 mA g(-1) up to 500 cycles, especially; for SIBs, a high capacity of 100 mAh g(-1) was maintained at 25 mA g(-1) after 115 cycles in the potential range of 2.9-0.5 V.

20.
ISME J ; 8(8): 1691-703, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24671088

ABSTRACT

A variety of microbially mediated metabolic pathways impact biogeochemical cycling in terrestrial subsurface environments. However, the role that viruses have in influencing microbial mortality and microbial community structure is poorly understood. Here we investigated the production of viruses and change in microbial community structure within shallow alluvial aquifer sediment slurries amended with (13)C-labeled acetate and nitrate. Biostimulation resulted in production of viruses concurrent with acetate oxidation, (13)CO2 production and nitrate reduction. Interestingly, change in viral abundance was positively correlated to acetate consumption (r(2)=0.6252, P<0.05) and (13)CO2 production (r(2)=0.6572, P<0.05); whereas change in cell abundance was not correlated to acetate consumption or (13)CO2 production. Viral-mediated cell lysis has implications for microbial community structure. Betaproteobacteria predominated microbial community composition (62% of paired-end reads) upon inoculation but decreased in relative abundance and was negatively correlated to changes in viral abundance (r(2)=0.5036, P<0.05). As members of the Betaproteobacteria decreased, Gammaproteobacteria, specifically Pseudomonas spp., increased in relative abundance (82% of paired-end reads) and was positively correlated with the change in viral abundance (r(2)=0.5368, P<0.05). A nitrate-reducing bacterium, Pseudomonas sp. strain Alda10, was isolated from these sediments and produced viral-like particles with a filamentous morphology that did not result in cell lysis. Together, these results indicate that viruses are linked to carbon biogeochemistry and community structure in terrestrial subsurface sediments. The subsequent cell lysis has the potential to alter available carbon pools in subsurface environments, additionally controlling microbial community structure from the bottom-up.


Subject(s)
Bacteria/classification , Carbon/metabolism , Geologic Sediments/microbiology , Nitrates/metabolism , Virus Physiological Phenomena , Acetates/metabolism , Bacteria/isolation & purification , Bacteria/metabolism , Betaproteobacteria/isolation & purification , Carbon Dioxide/metabolism , Gammaproteobacteria/isolation & purification , Geologic Sediments/virology , Groundwater , Oxidation-Reduction
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