Staphylococcus aureus Enterotoxin B Is a Cofactor of Food Allergy beyond a Superantigen.

Staphylococcus aureus enterotoxin B (SEB), one of the most common bacterial toxins in food contamination, has been poorly understood in relationship to food allergy outcomes. To investigate whether the ingestion of enterotoxins in food allergens could affect the development of food allergy, OVA-sensitized female BALB/c mice were challenged with OVA added with different doses of SEB or LPS. Allergic symptoms, such as diarrhea rate and hypothermia, could be aggravated in mice challenged with OVA and a low dose of SEB. The increased differentiation of Th2 and reduced expression of CD103 in dendritic cells was found in mice coexposed to SEB and OVA. Additionally, there was an increasing differentiation of Th1 induced by a high dose of SEB. The expression of ST2+ in intestinal mast cells was also increased in mice sensitized with a low dose of SEB and OVA. Employing several in vitro cell culture models showed that the secretion of IL-33 from intestinal epithelial cells and IL-4 from group 2 innate lymphoid cells, activation of bone marrow-derived dendritic cells, and differentiation of naive T cells were induced by SEB and OVA. Our work proved that challenge with low-dose SEB and OVA partly aggravated the food allergy, suggesting a (to our knowledge) new finding of the potential cofactor of food allergy and that the contamination of SEB in food allergens deserves attention for allergic and normal individuals.

Interventions to improve access to primary care for inclusion health groups in England: a scoping review.

BACKGROUND: Everyone in England has the right to primary care without financial charges. Nevertheless, evidence shows that barriers remain for inclusion health populations such as vulnerable migrants, people experiencing homelessness, Gypsy, Roma, and Traveller (GRT) communities, and people who sell sex. There is little evidence for what works to improve access. This study was a scoping review of interventions to improve access to mainstream primary care for inclusion health groups in England. METHODS: In this scoping review, we searched databases (Embase, Medline, APA PsychInfo, the Cochrane Collaboration Library, Web of Science and CINAHL) and grey literature sources, including the National Health Service and National Institute for Clinical Excellence, for articles published in English between Jan 1, 2010, and Dec 31, 2020, with no limit on study design. Data were extracted according to inclusion criteria, including interventions taking place in England and targeting people with insecure immigration status, people who sell sex, people experiencing homelessness, and GRT communities. Results were presented in a narrative synthesis. FINDINGS: 39 studies describing one or more interventions were included: four peer-reviewed articles (one randomised trial, two quality improvement projects, and one mixed-methods study protocol) and 25 grey literature items (38 interventions in total). Interventions mostly targeted people with insecure immigration status (17/38, 45%), and a majority (12/38, 32%) took place in London. The most common types of intervention were training, education, and resources (such as leaflets or websites) for patients or staff (25/38, 66%), and most interventions targeted GP registration processes (28/38, 74%). Interventions commonly involved voluntary and community sector organisations (16/38, 42%). Most interventions were not evaluated to understand their effectiveness (23/38, 61%). Sources with evaluations identified staff training, direct patient advocacy, and involvement of people with lived experience as effective elements. INTERPRETATION: Interventions to improve access to primary care for inclusion health groups in England were heterogeneous, commonly undertaken at community level, and developed to serve local inclusion health groups. Considerations for policymakers and practitioners include groups and geographical areas less commonly included in interventions, the elements of positive practice identified in evaluations, and the need for evaluation of future interventions. FUNDING: National Institute for Health and Care Research (NIHR 202050).

Perspectives on registration to primary care from inclusion health groups in England: a mixed-method study.

BACKGROUND: Although everyone living in the UK is entitled to access free primary care within the National Health Service (NHS), evidence shows that people in need of health care are wrongly being refused access. This study aimed to explore the perspectives of individuals from inclusion health groups on primary care registration and accessibility. METHODS: This was a mixed-methods study. From Oct 5, 2022, to Feb 20, 2023, we surveyed 49 people (36 [73%] men; 12 [24%] women) and interviewed 25 other (14 [56%] men; 11 [44%] women) who were service users of the University College London Hospital Find & Treat mobile service. This service included people with lived experience of homelessness, asylum seeking, addiction, selling sex, and irregular immigration. We recruited these participants through hostels for people with ongoing addiction and complex needs, initial asylum accommodation centres, and day shelters. Our research team included two peer researchers. FINDINGS: Of those surveyed, 25 (51%) perceived their access to primary health-care services as good, and 17 (35%) reported obstacles to going to the general practitioner (GP). Participants described multiple barriers to registering for GP surgeries, including a lack of understanding and poor communication with NHS services, a fear of discrimination, and a lack of digital access that prevents information seeking and access to services. Respondents also reported using emergency services instead of primary care because they were more immediately accessible without previous registration. Facilitators to GP registration included one-on-one support and outreach work that helps people navigate into services and know their rights, and the use of specialist GP services, which are perceived as more accepting, especially for people experiencing homelessness. INTERPRETATION: The barriers to registration identified are related to both individual and group level characteristics and produce both similar and divergent needs between different inclusion health groups. The need for additional support during registration was clear, and our work highlights the requirement for interventions to improve access to primary care for underserved groups, as well as coordinated policy action. One-on-one support in particular, either outreach or provided in services where inclusion health groups spend time, appears to be a key facilitator to ensuring comprehensive and fast access to GP services. FUNDING: National Institute for Health and Care Research (NIHR).

Investigating the nexus of metabolic syndrome, serum uric acid, and dementia risk: a prospective cohort study.

BACKGROUND: The global dementia prevalence is surging, necessitating research into contributing factors. We aimed to investigate the association between metabolic syndrome (MetS), its components, serum uric acid (SUA) levels, and dementia risk. METHODS: Our prospective study comprised 466,788 participants without pre-existing MetS from the UK Biobank. We confirmed dementia diagnoses based on the ICD-10 criteria (F00-03). To evaluate the dementia risk concerning MetS, its components, and SUA levels, we applied Cox proportional hazards models, while adjusting for demographic factors. RESULTS: Over a median follow-up of 12.7 years, we identified 6845 dementia cases. Individuals with MetS had a 25% higher risk of all-cause dementia (hazard ratio [HR] = 1.25, 95% confidence interval [CI] = 1.19-1.31). The risk increased with the number of MetS components including central obesity, dyslipidemia for high-density lipoprotein (HDL) cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides. Particularly for those with all five components (HR = 1.76, 95% CI = 1.51-2.04). Dyslipidemia for HDL cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides were independently associated with elevated dementia risk (p < 0.01). MetS was further linked to an increased risk of all-cause dementia (11%) and vascular dementia (VD, 50%) among individuals with SUA levels exceeding 400 µmol/L (all-cause dementia: HR = 1.11, 95% CI = 1.02-1.21; VD: HR = 1.50, 95% CI = 1.28-1.77). CONCLUSIONS: Our study provides robust evidence supporting the association between MetS, its components, and dementia risk. These findings emphasize the importance of considering MetS and SUA levels in assessing dementia risk, offering valuable insights for prevention and management strategies.

Oxidative Stress Initiates Receptor-Interacting Protein Kinase-3/Mixed Lineage Kinase Domain-Like-Mediated Corneal Epithelial Necroptosis and Nucleotide-Binding Oligomerization Domain-Like Receptor Protein 3 Inflammasome Signaling during Fungal Keratitis.

Fungal keratitis remains a major cause of severe visual loss in developing countries because of limited choices of therapy. The progression of fungal keratitis is a race between the innate immune system and the outgrowth of fungal conidia. Programmed necrosis (necroptosis), a type of proinflammatory cell death, has been recognized as a critical pathologic change in several diseases. However, the role and potential regulatory mechanisms of necroptosis have not been investigated in corneal diseases. The current study showed, for the first time, that fungal infection triggered significant corneal epithelial necroptosis in human/mouse/in vitro models. Moreover, a reduction in excessive reactive oxygen species release effectively prevented necroptosis. NLRP3 knockout did not affect necroptosis in vivo. In contrast, ablation of necroptosis via RIPK3 knockout significantly delayed migration and inhibited the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome in macrophages, which enhanced the progression of fungal keratitis. Taking these findings together, the study indicated that overproduction of reactive oxygen species in fungal keratitis leads to significant necroptosis in the corneal epithelium. Furthermore, the necroptotic stimuli-mediated NLRP3 inflammasome serves as a driving force in host defense against fungal infection.

Liquid Crystalline Nanoparticles via Polymerization-Induced Self-Assembly: Morphology Evolution and Function Regulation.

Liquid crystalline nanoparticles (LC NPs) are a kind of polymer NPs with LC mesogens, which can form special anisotropic morphologies due to the influence of LC ordering. Owing to the stimuli-responsiveness of the LC blocks, LC NPs show abundant morphology evolution behaviors in response to external regulation. LC NPs have great application potential in nano-devices, drug delivery, special fibers and other fields. Polymerization-induced self-assembly (PISA) method can synthesize LC NPs at high solid content, reducing the harsh demand for reaction solvent of the LC polymers, being a better choice for large-scale production. In this review, we introduced recent research progress of PISA-LC NPs by dividing them into several parts according to the LC mesogen, and discussed the improvement of experimental conditions and the potential application of these polymers.

Global, Regional, and National Incidence Trend Analysis of Malignant Skin Melanoma Between 1990 and 2019, and Projections Until 2034.

BACKGROUND: The goal of this study was to evaluate the global burden of malignant skin melanoma (MSM) from 1990 to 2019 using MSM-related data from the Global Burden of Disease study. METHODS: The incidences' relationships with the social-demographic index (SDI) and human developmental index (HDI) were investigated. To determine significant changes in incidence trends, the joinpoint regression model was used. To demonstrate trends in MSM mortality rates, an Age-Period-Cohort framework was conducted. For the projection of new cases and the age-standardized incidence rate (ASR) of MSM incidence to 2034, the Nordpred method was used. RESULTS: In 2019, the ASR incidence per 100, 000 people for MSM was 3.6 (95% UI, 2.6-4.2). MSM prevalence increased in most countries between 1990 and 2019 (average annual percentage change >0). HDI and annual percentage change (APC) (ρ = .63, P < .001), as well as SDI and ASR, had a positive correlation. The total MSM mortality rate declined globally, with an APC of -.61%. Likewise, the mortality rate for the age group of people with ages <77.5 years declined. Predictive analysis demonstrated a declining trend in ASR incidence and a growing number of MSM. CONCLUSION: There are significant differences in ASR incidence among regions and countries. Despite decreases in ASR incidence and fatality, MSM remains one of the leading sources of cancer mortality and morbidity globally. MSM necessitates more primary prevention measures and screening in high-risk areas.

In Situ S-Doping Engineering for Highly Efficient NH3-SCR over Metal-Free Carbon Catalysts: A Novel Synergetic Promotional Mechanism.

Cyclic desulfurization-regeneration-denitrification based on metal-free carbon materials is one of the most promising ways to remove NOx and SO2 simultaneously. However, the impact of S-doping induced by the cyclic desulfurization and regeneration (C-S-R) process on the selective catalytic reduction (SCR) is not well understood. Herein, it is demonstrated that the C-S-R process at 500 °C induces in situ S-doping with a significant accumulation of C-S-C structures. NOx conversion was dramatically enhanced from 18.95% of the original sample to 84.55% of the S-doped sample. Density functional theory calculations revealed that the C-S-C structure significantly regulates the electronic structure of the C atom adjacent to the ketonic carbonyl group, thereby significantly altering the NH3 adsorption configuration with superior adsorption capacity. Moreover, S-doping induces an extra electron transfer between the N atom of the NH3 molecule and the C atom of the carbon plane, thereby promoting the activation of NH3 over the ketonic carbonyl group with a reduced energy barrier. This study elucidates a synergetic promotional mechanism between the ketonic carbonyl group and the C-S-C structure for SCR, offering a novel design strategy for high-performance heteroatom-doped carbon catalysts in industrial applications.

Influence of Oxygen Vacancy-Induced Coordination Change on Pd/CeO2 for NO Reduction.

The byproduct formation in environmental catalysis is strongly influenced by the chemical state and coordination of catalysts. Herein, two Pd/CeO2 catalysts (PdCe-350 and PdCe-800) with varying oxygen vacancies (Ov) and coordination numbers (CN) of Pd were prepared to investigate the mechanism of N2O and NH3 formation during NO reduction by CO. PdCe-350 exhibits a higher density of Ov and Pd sites with higher CN, leading to an enhanced metal-support interaction by electron transformation from the support to Pd. Consequently, PdCe-350 displayed increased levels of byproduct formation. In situ spectroscopies under dry and wet conditions revealed that at low temperatures, the N2O formation strongly correlated with the Ov density through the decomposition of chelating nitro species on PdCe-350. Conversely, at high temperatures, it was linked to the reactivity of Pd species, primarily facilitated by monodentate nitrates on PdCe-800. In terms of NH3 formation, its occurrence was closely associated with the activation of H2O and C3H6, since a water-gas shift or hydrocarbon reforming could provide hydrogen. Both bridging and monodentate nitrates showed activity in NH3 formation, while hyponitrites were identified as key intermediates for both catalysts. The insights provide a fundamental understanding of the intricate relationship among the local coordination of Pd, surface Ov, and byproduct distribution.

A xonotlite nanofiber bioactive 3D-printed hydrogel scaffold based on osteo-/angiogenesis and osteoimmune microenvironment remodeling accelerates vascularized bone regeneration.

BACKGROUND: Coordination between osteo-/angiogenesis and the osteoimmune microenvironment is essential for effective bone repair with biomaterials. As a highly personalized and precise biomaterial suitable for repairing complex bone defects in clinical practice, it is essential to endow 3D-printed scaffold the above key capabilities. RESULTS: Herein, by introducing xonotlite nanofiber (Ca6(Si6O17) (OH)2, CS) into the 3D-printed silk fibroin/gelatin basal scaffold, a novel bone repair system named SGC was fabricated. It was noted that the incorporation of CS could greatly enhance the chemical and mechanical properties of the scaffold to match the needs of bone regeneration. Besides, benefiting from the addition of CS, SGC scaffolds could accelerate osteo-/angiogenic differentiation of bone mesenchymal stem cells (BMSCs) and meanwhile reprogram macrophages to establish a favorable osteoimmune microenvironment. In vivo experiments further demonstrated that SGC scaffolds could efficiently stimulate bone repair and create a regeneration-friendly osteoimmune microenvironment. Mechanistically, we discovered that SGC scaffolds may achieve immune reprogramming in macrophages through a decrease in the expression of Smad6 and Smad7, both of which participate in the transforming growth factor-ß (TGF-ß) signaling pathway. CONCLUSION: Overall, this study demonstrated the clinical potential of the SGC scaffold due to its favorable pro-osteo-/angiogenic and osteoimmunomodulatory properties. In addition, it is a promising strategy to develop novel bone repair biomaterials by taking osteoinduction and osteoimmune microenvironment remodeling functions into account.

Quercetin-loaded mesoporous nano-delivery system remodels osteoimmune microenvironment to regenerate alveolar bone in periodontitis via the miR-21a-5p/PDCD4/NF-κB pathway.

BACKGROUND: Impaired osteo-/angiogenesis, excessive inflammation, and imbalance of the osteoimmune homeostasis are involved in the pathogenesis of the alveolar bone defect caused by periodontitis. Unfortunately, there is still a lack of ideal therapeutic strategies for periodontitis that can regenerate the alveolar bone while remodeling the osteoimmune microenvironment. Quercetin, as a monomeric flavonoid, has multiple pharmacological activities, such as pro-regenerative, anti-inflammatory, and immunomodulatory effects. Despite its vast spectrum of pharmacological activities, quercetin's clinical application is limited due to its poor water solubility and low bioavailability. RESULTS: In this study, we fabricated a quercetin-loaded mesoporous bioactive glass (Quercetin/MBG) nano-delivery system with the function of continuously releasing quercetin, which could better promote the bone regeneration and regulate the immune microenvironment in the alveolar bone defect with periodontitis compared to pure MBG treatment. In particular, this nano-delivery system effectively decreased injection frequency of quercetin while yielding favorable therapeutic results. In view of the above excellent therapeutic effects achieved by the sustained release of quercetin, we further investigated its therapeutic mechanisms. Our findings indicated that under the periodontitis microenvironment, the intervention of quercetin could restore the osteo-/angiogenic capacity of periodontal ligament stem cells (PDLSCs), induce immune regulation of macrophages and exert an osteoimmunomodulatory effect. Furthermore, we also found that the above osteoimmunomodulatory effects of quercetin via macrophages could be partially blocked by the overexpression of a key microRNA--miR-21a-5p, which worked through inhibiting the expression of PDCD4 and activating the NF-κB signaling pathway. CONCLUSION: In summary, our study shows that quercetin-loaded mesoporous nano-delivery system has the potential to be a therapeutic approach for reconstructing alveolar bone defects in periodontitis. Furthermore, it also offers a new perspective for treating alveolar bone defects in periodontitis by inhibiting the expression of miR-21a-5p in macrophages and thereby creating a favorable osteoimmune microenvironment.

Imaging assessment of conjunctival goblet cells in dry eye disease.

Dry eye disease (DED) is a widespread, multifactorial, and chronic disorder of the ocular surface with disruption of tear film homeostasis as its core trait. Conjunctival goblet cells (CGCs) are specialised secretory cells found in the conjunctival epithelium that participate in tear film formation by secreting mucin. Changes in both the structure and function of CGCs are hallmarks of DED, and imaging assessment of CGCs is important for the diagnosis, classification, and severity evaluation of DED. Existing imaging methods include conjunctival biopsy, conjunctival impression cytology and in vivo confocal microscopy, which can be used to assess the morphology, distribution, and density of the CGCs. Recently, moxifloxacin-based fluorescence microscopy has emerged as a novel technique that enables efficient, non-invasive and in vivo imaging of CGCs. This article presents a comprehensive overview of both the structure and function of CGCs and their alterations in the context of DED, as well as current methods of CGCs imaging assessment. Additionally, potential directions for the visual evaluation of CGCs are discussed.

Study on the Application of Group Psychological Nursing in Non-suicidal Self-injury among Adolescents.

Background: Non-suicidal self-injury (NSSI) refers to direct and deliberate suicidal actions that damage the body but are not recognized by society and culture. Adolescence is the transition period when children change into adult roles. At this time, teenagers are in the critical development period of physical and mental intelligence, and all aspects of their development have not yet been fully developed, so there are fierce inner conflicts. If the psychological problems of teenagers do not get timely counseling, it is very likely to choose self-injury suicide behavior, in such an extreme way to vent their bad emotions. The prevalence rate of NSSI among adolescents is much higher than that of other age groups. Studies have shown that psychological nursing is safe and effective, which can alleviate patients' negative emotions and avoid NSSI. Objective: To explore the impact of group psychological nursing with guardian participation on reducing NSSI behaviors and improving psychological well-being among adolescents. Design: This was a retrospective study. Setting: This study was performed in the Departments of the Third Psychiatry, Hangzhou Seventh People's Hospital. Participants: 132 adolescent patients with NSSI admitted to our center from August 2020 to July 2022 were selected as subjects and divided into 2 groups according to the time of admission, with 66 patients in each group. Interventions: Patients in the control group (CG) received drug therapy and commonly used cognitive behavioral therapy. Patients in the observation group (OG) received group psychological nursing with guardian participation. The participation of the guardian strengthens the level of understanding, tolerance and support of both parties, and helps to enhance the strength of family support, which in turn relives negative emotions. Primary Outcome Measures: (1) Ottawa self-injury inventory (OSI) scores were used to assess NSSI behavior severity; (2) Self-rating Anxiety Scale (SAS) and self-rating Depression Scale (SDS) scores were used to assess anxiety and depression; (3) General Self-efficacy Scale (GSES) scores were used to assess self-efficacy; (4) Trait Coping Style Questionnaire (TCSQ) scores were used to assess the quality of life; (5) social function Assessment Scale (SSPI) scores were used to assess social function; (6) Adolescent Life Events Scale (ASLEC) scores were used to evaluate the stress intensity of coping with life events; (7) multidimensional sub-health questionnaire assessment (MSQA) scores were used to assess adolescents' physical and psychological sub-health. Results: Before intervention, there were no significant differences in OSI, SAS, SDS, GSES, TCSO, SSPI ASLEC, and MSQA scores in both groups (P > .05). Compared to before intervention, the scores of OSI, SAS, SDS, GSES, TCSO, SSPI ASLEC and MSQA in both groups were improved after intervention (P < .05). The observation group showed significant improvements across all measures compared to the control group, indicating a reduction in NSSI behaviors and improvements in mental health. Conclusion: Application of group psychological nursing with guardian participation in adolescent patients with NSSI behavior can better reduce NSSI behavior and improve physical and mental health, underline the importance of family support in treating NSSI, which also highlights the importance of family support in the treatment of NSSI.

Shedding light on the interaction of ovalbumin and resveratrol: structure, digestibility, transport, and allergenicity assessment of OVA-RES complexes.

BACKGROUND: The interaction between food allergens and plant polyphenols has become a safe and effective management strategy to prevent food allergies. Ovalbumin (OVA) is the most abundant allergen in egg whites. Resveratrol (RES) is a plant polyphenol that is abundant in red grapes, berries, and peanuts, and has an anti-allergic effect on allergy-related immune cells. However, there is little information about the effect of RES on the allergenicity of OVA. In this study, the effect of RES on the allergenicity of OVA was investigated. RESULTS: Molecular docking and spectroscopic studies indicated that the addition of RES changed the structure of OVA. The digestion and transfer rate of OVA-RES were effectively improved with an in vitro gastrointestinal digestion model and Caco-2 cell model, especially when the molar ratio of OVA-RES was 1:20. Meanwhile, the KU812 cell degranulation assay proved that the potential allergenicity was remarkably decreased while the molar ratios of OVA-RES were increased to 1:20. Furthermore, hydrogen bonds and van der Waals forces were the dominating forces to stabilize the OVA-RES complexes. CONCLUSION: All the findings demonstrated that the potential allergenicity of OVA was reduced when interacting with RES, and RES can be a potential food material for preparing a hypoallergenic protein, especially for egg allergy. © 2023 Society of Chemical Industry.

Comprehensive Analysis Reveals Prognostic and Therapeutic Immunity-Related Biomarkers for Pediatric Metastatic Osteosarcoma.

Background and Objectives: Osteosarcoma, the most prevalent malignant bone tumor in children and adolescents, presents a complex pathogenesis characterized by various genetic and epigenetic alterations. This study aims to identify key differentially expressed genes (DEGs) in pediatric osteosarcoma, with a focus on those influencing metastasis and patient survival. Materials and Methods: We utilized the GSE33382 dataset from the GEO database for a comprehensive bioinformatic analysis. This included a protein-protein interaction (PPI) network analysis, Cox regression, and Kaplan-Meier survival analysis to identify central DEGs associated with osteosarcoma metastasis and patient survival. Results: Our analysis identified 88 DEGs related to osteosarcoma metastasis. Among them, three survival-related central DEGs-C1QA, CD74, and HLA-DMA-were significantly linked to patient outcomes. Further correlation analysis established a strong relationship between these genes, tumor mutation burden (TMB), immune checkpoint gene expression, and overall survival. Notably, C1QA and CD74 exhibited higher expression in non-metastatic osteosarcoma cases, suggesting a potential role in disease progression. Conclusions: The identified DEGs, particularly C1QA, CD74, and HLA-DMA, may serve as critical biomarkers for pediatric osteosarcoma prognosis and potential targets for immunotherapy. These findings provide a deeper understanding of the molecular landscape of osteosarcoma and open new avenues for therapeutic intervention.

Pretreatment with 3-methyladenine ameliorated Pseudomonas aeruginosa-induced acute pneumonia by inhibiting cell death of neutrophils in a mouse infection model.

Pseudomonas aeruginosa is one of the leading causes of nosocomial infections worldwide. Clinical isolates that are resistant to multiple antimicrobials make it intractable. The interactions between P. aeruginosa and host cell death have multiple effects on bacterial clearance and inflammation; however, the potential intervention effects remain to be defined. Herein, we demonstrated that intravenous administration of 3-methyladenine before, but not after, P. aeruginosa infection enhanced autophagy-independent survival, which was accompanied by a decrease in the bacterial load, alleviation of pathology and reduction in inflammatory cytokines, in an acute pneumonia mouse model. Interestingly, these beneficial effects were not dependent on neutrophil recruitment or phagocytosis, but on the enhanced killing capacity induced by inhibiting the cell death of 3-MA pretreated neutrophils. These findings demonstrate a novel protective role of 3-MA pretreatment in P. aeruginosa-induced acute pneumonia.

CCR2: A characteristic chemokine receptor in normal and pathological intestine.

C-C motif chemokine receptor 2 (CCR2), together with its ligands, especially C-C motif ligand 2 (CCL2), to which CCR2 has the highest affinity, form a noteworthy signaling pathway in recruiting macrophages for the immune responses among variegated disorders in vivo environment. Scientometric methods are used to analyze intestine-related CCR2 expression. We describe the current knowledge on biological function of CCR2 in physiological intestine in three dimensions, namely its effects on stromal cells, angiogenesis, and remodeling. However, anomalous expression of CCR2 has also been conveyed to correlate with detrimental outcomes in intestine, such as infective colitis, inflammatory bowel disease, carcinogenesis, and colon-related metastasis. In this article, we briefly summarize recent experimental works on CCR2 and its ligands, mostly CCL2, in intestinal-related physiological and pathological states to ravel out their working mechanisms in intestinal diseases.

Potential Risk of NH3 Slip Arisen from Catalytic Inactive Site in Selective Catalytic Reduction of NOx with Metal-Free Carbon Catalysts.

Ammonia emissions from industrial processes have rapidly increased in the past years. Recent advances have used carbon-based selective catalytic reduction (SCR) technology combined with a reaction-regeneration process to reduce NOx from sintering flue gas, while NH3 slip is seldom accounted for in this process. This study demonstrates that although the electrophilic carboxyl groups (-COOH) on metal-free carbon catalysts exhibit strong adsorption toward NH3, they do not participate in the SCR reaction. As a result of the competitive adsorption of NH3 in the reaction step, these catalytic inactive carboxyl groups not only prolong the time to the SCR steady state, but also result in the potential risk of NH3 slip. A linear relationship with the equimolar ratio between carboxyl groups and slipped NH3 was established in the regeneration steps. The slip of NH3 could be alleviated by the decomposition of carboxyl groups, and special attention should be paid to the presence of inactive sites with strong NH3 adsorption on industrial-employed carbon catalysts. In addition to advancing the understanding of the NH3-SCR mechanism, this work also provides valuable opportunities for the control of ammonia emissions from industrial processes.

Identification of Active Sites over Metal-Free Carbon Catalysts for Flue Gas Desulfurization.

Carbon-based catalysts have been extensively used for flue gas desulfurization (FGD) and have exerted great importance in controlling SO2 emissions over the past decades. However, many fundamental details about the nature of the active sites and desulfurization mechanism still remain unclear. Here, we reported the experimental and theoretical identifications of active sites in FGD on carbon catalysts. Temperature-programmed decomposition allowed us to modulate the number of oxygen functional groups on carbon catalysts and to establish its correlation with desulfurization activity. Selective passivation further demonstrated that the ketonic carbonyl (C═O) groups are the intrinsic active sites for FGD reaction. Combined with transient response experiments, quasi-in situ X-ray photoelectron spectroscopy, and density functional theory simulations, it was revealed that desulfurization reaction on carbon catalysts mainly proceeded via the Langmuir-Hinshelwood mechanism, during which the nucleophilic ketonic C═O groups served as active sites for chemically absorbing SO2 and their adjacent sp2-hybridized carbon atoms dissociatively activated O2. It also turned out that the formation of H2SO4 is the reaction barrier step. The output of this study should not only advance the understanding of desulfurization at the atomic scale but also provide a general guideline for the rational design of efficient carbon catalysts for FGD.

Nf1-dependent tumors require a microenvironment containing Nf1+/-- and c-kit-dependent bone marrow.

Interactions between tumorigenic cells and their surrounding microenvironment are critical for tumor progression yet remain incompletely understood. Germline mutations in the NF1 tumor suppressor gene cause neurofibromatosis type 1 (NF1), a common genetic disorder characterized by complex tumors called neurofibromas. Genetic studies indicate that biallelic loss of Nf1 is required in the tumorigenic cell of origin in the embryonic Schwann cell lineage. However, in the physiologic state, Schwann cell loss of heterozygosity is not sufficient for neurofibroma formation and Nf1 haploinsufficiency in at least one additional nonneoplastic lineage is required for tumor progression. Here, we establish that Nf1 heterozygosity of bone marrow-derived cells in the tumor microenvironment is sufficient to allow neurofibroma progression in the context of Schwann cell Nf1 deficiency. Further, genetic or pharmacologic attenuation of c-kit signaling in Nf1+/- hematopoietic cells diminishes neurofibroma initiation and progression. Finally, these studies implicate mast cells as critical mediators of tumor initiation.