ABSTRACT
BACKGROUND: Fiberglass has a larger aerodynamic diameter and is less likely to be inhaled into the lungs. Further, it will be cleared even if it is mechanically broken into smaller pieces and inhaled into the lungs. Fiberglass lung disease has been well documented if long term exposure but was thought reversible and would not cause severe diseases. The diagnosis of fiberglass lung disease depends on exposure history and histopathological findings. However, the exact occupational exposure history is often difficult to identify because mixed substance exposure often occurs and fiberglass disease is not as well-known as asbestosis. CASE PRESENTATION: A 66-year-old man had unexplained transudative pericardial effusion requiring pleural pericardial window operation twice at another medical center where asbestosis was told because of his self-reported long-term asbestosis exposure and the histopathological finding of a ferruginous body in his lung. Constrictive pericarditis developed two years later and resulted in congestive heart failure. Radical pericardiectomy combined with lung biopsy was performed following chest computed tomography imaging and the transudative nature of pericardial effusion not compatible with asbestosis. However, the histopathologic findings of his lung and pericardium at our hospital only showed chronic fibrosis without any asbestosis body. The patient's lung was found to be extremely fragile during a lung biopsy; histopathologic specimens were reviewed, and various fragments of fiberglass were found in the lung and pericardium. The patient's occupational exposure was carefully reevaluated, and he restated that he was only exposed to asbestosis for 1-2 years but was heavily exposed to fiberglass for more than 40 years. This misleading exposure history was mainly because he was only familiar with the dangers of asbestos. Since most fiberglass lung diseases are reversible and the symptoms of heart failure resolve soon after surgery, only observation was needed. Ten months after radical pericardiectomy, his symptoms, pleural effusion, and impaired pulmonary function eventually resolved. CONCLUSION: Fiberglass could cause inflammation of the pericardium, resulting in pericardial effusion and constrictive pericarditis, which could be severe and require radical pericardiectomy. Exact exposure history and histopathological examinations are the key to diagnosis.
Subject(s)
Glass , Occupational Exposure , Pericarditis, Constrictive , Humans , Male , Pericarditis, Constrictive/etiology , Pericarditis, Constrictive/diagnosis , Pericarditis, Constrictive/surgery , Aged , Occupational Exposure/adverse effects , Asbestosis/complications , Asbestosis/diagnosis , Asbestosis/pathology , Tomography, X-Ray Computed , Lung/pathology , Lung/diagnostic imaging , Pericardiectomy , Pericardial Effusion/etiologyABSTRACT
Imaging and characterization of surface plasmon polaritons (SPPs) are crucial for the research and development of the plasmonic devices and circuits. Here, we report on direct imaging of SPPs propagation on SiO2/metal interface with subwavelength spatial resolution using up-conversion fluorescence microscopy, that exploits rare-earth ions, such as Er3+, Yb3+, and Nd3+, doped nanoparticles as the fluorophores. We demonstrated that by further taking the intensity ratio of the image obtained with fluorescent emission at different wavelengths, we are able to substantially enhance the features associated to the SPP wavefronts in the image for quantitative analysis, such as the wavevector and propagation direction of the SPPs. Our results agree with the theoretic prediction of the SPP wavelengths quantitatively. We further demonstrate the evolution of the SPP wavefronts due to refraction SPPs, and reproduced the experiment with finite difference time domain (FDTD) method simulations. The relative refractive index of SPP estimated from the experiment also agrees quantitatively with those extracted from the theory and the simulation.
ABSTRACT
The synthesis of a range of 3,3'-bipyrazolo[1,5-a]pyridine derivatives via direct cross-dehydrogenative coupling of pyrazolo[1,5-a]pyridine precursors is herein presented. This simple and efficient methodology involving palladium(II)-catalyzed C-H bond activation showed good functional group tolerance and product yield (up to 94%). Through the mechanistic insights gained from both kinetic isotope effect experimental studies and density functional theory calculations, a plausible reaction mechanism was outlined. Furthermore, subsequent derivatizations of the resulting 7,7'-diaryl-3,3'-bipyrazolo[1,5-a]pyridines, executed by performing palladium-mediated ortho C-H bond activation followed by hypervalent iodine-induced chlorination, rendered this series of compounds more extended π-conjugation and twisted conformations. Our study on these bipyrazolo[1,5-a]pyridine-based luminogens provides new opportunities for tailor-made organic luminescent materials.
Subject(s)
Palladium , Pyridines , Catalysis , Halogenation , Iodides , Palladium/chemistry , Pyridines/chemistryABSTRACT
Liver cancer remains a leading cause of death, despite advances in anti-cancer therapies. To develop novel drugs, natural products are being considered as a good source for exploration. In this study, a natural product isolated from a soft coral was applied to evaluate its anti-cancer activities in hepatocellular carcinoma SK-HEP-1 cells. Sinularin was determined to have half-maximal inhibitory concentration (IC50) values of ~10 µM after 24, 48, and 72 h. The TUNEL assay and annexin V/PI staining results showed that sinularin induced DNA fragmentation and apoptosis, respectively. An investigation at the molecular level demonstrated that the expression levels of cleaved caspases 3/9 were significantly elevated at 10 µM sinularin. Mitochondrial and intracellular reactive oxygen species (ROS) levels were significantly increased following sinularin treatment, which also affected the mitochondrial membrane potential. In addition, it significantly lowered the mitochondrial respiration parameters and extracellular acidification rates at 10 µM. Further investigation showed that sinularin significantly attenuated wound healing, cell migration, and potential colony formation at 10 µM. Fluorescence microscopic observations showed that the distribution of F-actin filaments was significantly altered at 10 µM sinularin. Supported by Western blot analyses, the expression levels of AKT, p-ERK (extracellular-signal-related kinase), vimentin and VEGF were significantly down-regulated, whereas p-p38, pJNK and E-cadherin were significantly increased. Overall, at the IC50 concentration, sinularin was able to significantly affect SK-HEP-1 cells.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Carcinoma, Hepatocellular , Cytoskeleton/metabolism , Diterpenes/pharmacology , Heterocyclic Compounds, 3-Ring/pharmacology , Liver Neoplasms , Mitochondria, Liver/metabolism , Animals , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/metabolism , Carcinoma, Hepatocellular/pathology , Cell Line, Tumor , Cytoskeleton/pathology , Humans , Liver Neoplasms/drug therapy , Liver Neoplasms/metabolism , Liver Neoplasms/pathology , MAP Kinase Signaling System/drug effects , Mitochondria, Liver/pathology , RatsABSTRACT
BACKGROUND: A lower level of consciousness is a common presentation in critical care, with many different causes and contributory factors, of which more than one may be present concurrently. CASE PRESENTATION: We described a woman with poorly controlled diabetes and steroid-dependent asthma who presented in a deep coma. She was found to have Streptococcus intermedius bacteremia and pyogenic ventriculitis that originated from right middle lobe pneumonia. Also, multiple small parenchymal lesions were observed on brain magnetic resonance imaging and increased protein concentration was noted in cerebral spinal fluid. Initially, her coma was thought to be due to diabetic ketoacidosis and septic encephalopathy. However, her lowered level of consciousness was disproportionate to either diabetic ketoacidosis or septic encephalopathy, and her clinical course was not as expected for these two conditions. Treatment with antibiotic, corticosteroid and antihelminthic drugs was administered resulting in improving consciousness. The Streptococcus intermedius pneumonia progressed to form a large cavity that needed an early surgical lobectomy and resulted in the unexpected diagnosis of chronic cavitary pulmonary aspergillosus. CONCLUSIONS: In critical care, a lowered level of consciousness may have many etiologies, and critical care clinicians should be familiar with the signs and symptoms of all possible causes to enable prompt diagnosis and appropriate treatment.
Subject(s)
Aspergillus/isolation & purification , Brain Diseases/diagnosis , Coma/diagnosis , Critical Care , Pneumonia, Bacterial/diagnosis , Pulmonary Aspergillosis/diagnosis , Streptococcal Infections/diagnosis , Streptococcus intermedius/isolation & purification , Adrenal Cortex Hormones/therapeutic use , Aged , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Diagnosis, Differential , Female , Follow-Up Studies , Humans , Magnetic Resonance Imaging , Pneumonia, Bacterial/drug therapy , Pneumonia, Bacterial/microbiology , Pulmonary Aspergillosis/drug therapy , Pulmonary Aspergillosis/microbiology , Streptococcal Infections/drug therapy , Streptococcal Infections/microbiology , Treatment OutcomeABSTRACT
BACKGROUND: Foreign body aspiration is less common in healthy adults, which makes diagnosis difficult. Early detection of smaller/sharp foreign bodies in the distal airway is more difficult because patients might have no symptoms and imaging studies could appear normal. Here we describe the course of a small, sharp foreign body (chicken bone) lodged in the distal airway of a healthy middle-aged woman. The chicken bone was initially thought to be an old calcified tuberculoma. However, it was encased in a dilated bronchus without obvious surrounding lymphadenitis or parenchymal infiltration, and it melted with time. Two years later, histopathological examination revealed that the calcified lesion was an aspirated chicken bone with a concomitant tuberculoma. CASE PRESENTATION: A 51-year-old woman showed an old calcified tuberculoma in the upper right lung lobe during routine examinations. It was "encased" in a dilated bronchus, although it was not raised from the surrounding lung parenchyma. The size of the calcified part decreased ("melted") with time, and the surrounding inflammation progressed 2 years later, a phenomenon never described in association with tuberculosis. Bronchoscopy revealed a fragment of chicken bone lodged in the next two branches of the upper right posterior bronchus. Surgical segmentectomy was performed, and histopathological examination revealed that the calcified lesion was formed by a fragment of chicken bone as well as a tuberculoma. Eventually, the patient recalled an episode of choking on a chicken bone 5 years ago; she believed that she had coughed it out completely at that time. CONCLUSIONS: The "melting" and "encased" phenomena observed in the present case could be useful imaging findings for early detection of small foreign body aspiration in the distal airway.
Subject(s)
Foreign Bodies/diagnostic imaging , Solitary Pulmonary Nodule/etiology , Tuberculoma/diagnostic imaging , Antitubercular Agents/therapeutic use , Comorbidity , Diagnosis, Differential , Female , Foreign Bodies/complications , Foreign Bodies/surgery , Humans , Middle Aged , Pneumonectomy , Solitary Pulmonary Nodule/diagnostic imaging , Solitary Pulmonary Nodule/surgery , Tomography, X-Ray Computed , Treatment Outcome , Tuberculoma/drug therapyABSTRACT
Zinc oxide nanoparticles (ZnONPs) are widely used in the manufacturing of many commercial products. Workers exposed to ZnO particles may develop metal fume fever. Our previous study suggested that the oropharyngeal aspiration of ZnONPs could cause eosinophilic airway inflammation and increase T helper 2 (Th2) cytokine expression in the absence of allergens in mice. ZnO has been used topically as a sunscreen and a therapeutic agent for dermatological conditions. To understand whether inhalation and topically applied ZnONPs might cause or exert an adjuvant effect on the development of allergic airway inflammation in mice, C57BL/6â¯J mice were exposed to filtered air or 2.5â¯mg/m3 ZnONPs via whole-body inhalation for 5â¯h a day over 5â¯days, and BALB/c mice were topically exposed to ZnONPs using modified mouse models of atopic dermatitis (AD) and asthma. Ovalbumin (OVA) solution was used as an allergen in the topical exposure experiments. A significantly increased eosinophil count and mixed Th1/Th2 cytokine expression were detected in the bronchoalveolar lavage fluid (BALF) after ZnONP inhalation. However, only mild eosinophilia and low Th2 cytokine expression were detected in the BALF after oropharyngeal OVA aspiration in the high-dose ZnONP topical treatment group. These results suggest that ZnONP inhalation might play a role in the development of allergic airway inflammation in mice. However, topically applied ZnONPs only play a limited role in the development of allergic airway inflammation in mice.
Subject(s)
Asthma/chemically induced , Dermatitis, Atopic/chemically induced , Eosinophilia/chemically induced , Metal Nanoparticles/toxicity , Zinc Oxide/toxicity , Administration, Inhalation , Administration, Topical , Animals , Asthma/diagnosis , Asthma/immunology , Bronchoalveolar Lavage Fluid/cytology , Dermatitis, Atopic/diagnosis , Dermatitis, Atopic/immunology , Disease Models, Animal , Eosinophilia/diagnosis , Eosinophilia/immunology , Female , Humans , Inhalation Exposure/adverse effects , Metal Nanoparticles/administration & dosage , Mice , Zinc Oxide/administration & dosageABSTRACT
BACKGROUND: The shell of Haliotis diversicolor, or shijueming (SJM), is a type of traditional Chinese medicine. The SJM has appeared in historical records as early as the third and fourth centuries. Historical records have revealed that SJM had mainly been used to treat eye diseases. After the Qing Dynasty (1757), records had emerged, detailing the use of SJM for treating skin injuries, particularly for treating poorly managed ulcers or traumatic wounds. Furthermore, in our anti-inflammation-screening system, SJM significantly inhibited the expression of pro-inflammatory proteins. Previous studies have yet to adopt an animal model to verify the phenomenon and described in the historical records regarding the efficacy of SJM in promoting wound healing. Besides, the mechanism of wound healing effect of SJM is also not clear. METHODS: This study applied in vitro and in vivo models, tissue section analysis, and western blotting to evaluate the effect of SJM on wound healing. The RAW 264.7 cells were used in anti-inflammatory activity assay and phagocytic assay. Male Wistar rats were used to evaluate the effect of SJM on burn injury healing. A copper block (2 × 2 cm, 150 g) preheated to 165 °C in a dry bath was used to contact the skin area for 10 s, thus creating a full-thickness burn injury. The results were analyzed by hematoxylin and eosin staining, picrosirius red staining and Western blotting. RESULTS: The results revealed that in the in vitro model, the presence of SJM decreased the inducible nitric oxide synthase (iNOS) expression and enhanced the functions of macrophages. The results of the rat burn injury model revealed that SJM decreased neutrophil infiltration, promoted wound healing, thus increasing the collagen I content and promoting the expression of transforming growth factor-beta 1 (TGF-ß1) protein. We speculate that the effect and mechanism of SJM on promoting wound healing is related to macrophage activation. In the inflammation phase, SJM alleviates inflammation by inhibiting iNOS expression and removing neutrophils through phagocytosis. Furthermore, SJM induces the secretion of TGF-ß1, converting collagen during the tissue remodeling phase. CONCLUSIONS: According to our review of relevant literature, this is the first study that applied an evidence-based method to verify that SJM alleviates inflammation, enhances phagocytosis, and triggers wound healing after burn injury. The study findings reveal that SJM provides a promising therapeutic option for treating burn injury.
Subject(s)
Animal Shells/chemistry , Burns/drug therapy , Gastropoda/chemistry , Wound Healing/drug effects , Animals , Cell Line , Male , Medicine, Chinese Traditional , Nitric Oxide Synthase Type II/metabolism , Phagocytosis/drug effects , Rats , Rats, WistarABSTRACT
Red mold rice (RMR) is a traditional food and folk medicine to Asian people and has recently become a popular health supplement. RMR has been shown to have some anticancer activities, although the mechanism for inducing cell death of human breast cancer cells is still not fully understood. In this study, bioactive extracts of RMR fermented by Monascus purpureus NTU 803 were analyzed for effects on apoptosis induction in human breast cancer cells. The RMR ethanol extract and ethyl acetate extract contain monacolin K, total phenols, and flavonoids, the three components that have been reported to have anticancer activity. Red mold rice extracts (RMRE) exhibited selective cytotoxic effect on MCF-7 cells. RMRE treatment induced apoptosis and cell cycle arrest at G2/M phase. Apoptosis was confirmed by annexin V-fluorescein isothiocyanate (FITC)/propidium iodide staining, the observation of characteristic chromatin condensation, nuclear DNA fragmentation, and poly(ADP-ribose) polymerase cleavage. Furthermore, the RMRE-induced apoptosis in MCF-7 cells may occur through a mitochondria-dependent pathway while triggering an appropriate balance of bax/bcl-2 and activation of caspase-9 and caspase-3 in a time-dependent manner. To conclude, RMRE exhibits direct cytotoxic and proapoptotic effects on MCF-7 cells and could be considered as a potential functional food for breast cancer prevention.
Subject(s)
Antineoplastic Agents/isolation & purification , Antineoplastic Agents/pharmacology , Apoptosis , Monascus/metabolism , Oryza/metabolism , Antineoplastic Agents/metabolism , Cell Line, Tumor , Cell Survival/drug effects , Fermentation , HumansABSTRACT
Although cuttlefish are capable of showing diverse camouflage body patterns against a variety of background substrates, whether they show background preference when given a choice of substrates is not well known. In this study, we characterized the background choice of post-embryonic cuttlefish (Sepia pharaonis) and examined the effects of rearing visual environments on their background preferences. Different rearing backgrounds (enriched, uniformly grey and checkerboard) were used to raise cuttlefish from eggs or hatchlings, and four sets of two-background-choice experiments (differences in contrast, shape, size and side) were conducted at day 1 and weeks 4, 8 and 12 post-hatch. Cuttlefish reared in the enriched environment preferred high-contrast backgrounds at all post-embryonic stages. In comparison, those reared in the impoverished environments (uniformly grey and checkerboard) had either reversed or delayed high-contrast background preference. In addition, cuttlefish raised on the uniformly grey background, exposed to a checkerboard briefly (0.5 or 3 h) at week 4 and tested at week 8 showed increased high-contrast background preference. Interestingly, cuttlefish in the enriched group preferred an object size similar to their body size at day 1 and week 4, but changed this preference to smaller objects at week 12. These results suggest that high-contrast backgrounds may be more adaptive for juvenile cuttlefish, and visually enriched environments are important for the development of these background preference behaviours.
Subject(s)
Decapodiformes/physiology , Vision, Ocular , Animals , Behavior, Animal , Body Patterning , Color , Developmental Biology/methods , Environment , Learning , Time Factors , Visual PerceptionABSTRACT
Host immunological pathways are delicate to cope with different types of pathogens. In this article, we divide immunological pathways into two groups: Immunoglobulin G-related eradicable immunities and Immunoglobulin A-related tolerable immunities. Once immune cells encounter an antigen, they can become anergic or trigger immune reactions. Immunoglobulin D B cells and γδ T cells are recognizing self-antigens to become anergic. Immunoglobulin M B cells and αß T cells can trigger host immune reactions. Eradicable immune responses can be divided into four groups: TH1/TH2/TH22/THαß (TH-T Helper cell groups). Tolerable immune responses can be divided into four groups: TH1-like/TH9/TH17/TH3. Four groups mean hosts can cope with four types of pathogens. Cancer is related to immune dysfunction. TH1-like immunity is pro-tumor immunity and THαß is anti-tumor immunity. TH1-like immunity is the host tolerable immunity against intracellular micro-organisms. THαß immunity is the host eradicable immunity against viruses. Cancer is also related to clonal anergy by Immunoglobulin D B cells and γδ T cells. Oncolytic viruses are related to the activation of anti-viral THαß immunity. M2 macrophages are related to the tolerable TH1-like immunity, and they are related to metastasis. This review is key to understanding the immune pathogenesis of cancer. We can then develop better therapeutic agents to treat cancer.
ABSTRACT
Glioblastoma multiforme (GBM) is a cancer of largely unknown cause that leads to a 5-year survival rate of approximately 7% in the United States. Current treatment strategies are not effective, indicating a strong need for the development of novel therapies. In this study, the outcomes of sinularin, a marine-derived product, were evaluated against GBM. Our cellular studies using GBM cells revealed that sinularin induces cell death. The measured half maximal inhibitory concentrations (IC50) values ranged from 30 to 6 µM at 24-72 h. Cell death was induced via the generation of ROS leading to mitochondria-mediated apoptosis. This was evidenced by annexin V/propidium iodine staining and an upregulation of cleaved forms of the pro-apoptotic proteins caspase 9, 3, and PARP, and supported by CellROXTM Green, MitoSOXTM Red, and CM-H2DCFDA staining methods. In addition, we observed a downregulation of the antioxidant enzymes SOD1/2 and thioredoxin. Upon treatment with sinularin at the ~IC50 concentration, mitochondrial respiration capacities were significantly reduced, as shown by measuring the oxygen consumption rates and enzymatic complexes of oxidative phosphorylation. Intriguingly, sinularin significantly inhibited indicators of angiogenesis such as vessel tube formation, cell migration, and cell mobility in human umbilical vein endothelial cells or the fusion cell line EA.Hy926. Lastly, in a transgenic zebrafish model, intersegmental vessel formation was also significantly inhibited by sinularin treatment. These findings indicate that sinularin exerts anti-brain cancer properties that include apoptosis induction but also antiangiogenesis.
ABSTRACT
Herein we report ketones as feedstock materials in radical cross-coupling reactions under Ni/photoredox dual catalysis. In this approach, simple condensation first converts ketones into prearomatic intermediates that then act as activated radical sources for cross-coupling with aryl halides. Our strategy enables the direct benzylation/benzoylation of (hetero)arenes under mild reaction conditions with high functional group tolerance.
ABSTRACT
The most common etiology of multiple pulmonary nodules is metastatic lung cancer. Although benign etiologies have been reported, mucoid impaction less commonly presents as multiple pulmonary nodules. Herein, we report the case of an 81-year-old demented man who presented with multiple pulmonary nodules due to mucoid impaction. Chest radiographs revealed rapid resolution after tracheostomy and adequate mucus clearance. We suggest that mucoid impaction may present as multiple pulmonary nodules mimicking multiple metastatic lung cancer.
ABSTRACT
Layered MoS2 is considered as one of the most promising two-dimensional photocatalytic materials for hydrogen evolution and water splitting; however, the electronic structure at the MoS2-liquid interface is so far insufficiently resolved. Measuring and understanding the band offset at the surfaces of MoS2 are crucial for understanding catalytic reactions and to achieve further improvements in performance. Herein, the heterogeneous charge transfer behavior of MoS2 flakes of various layer numbers and sizes is addressed with high spatial resolution in organic solutions using the ferrocene/ferrocenium (Fc/Fc+) redox pair as a probe in near-field scanning electrochemical microscopy, i.e. in close nm probe-sample proximity. Redox mapping reveals an area and layer dependent reactivity for MoS2 with a detailed insight into the local processes as band offset and confinement of the faradaic current obtained. In combination with additional characterization methods, we deduce a band alignment occurring at the liquid-solid interface.
ABSTRACT
BACKGROUND: Particulate matter (PM) has been associated with increased pulmonary and cardiovascular mortality and morbidity. Additionally, PM is known to exacerbate asthma. However, whether ambient PM exposure contributes to the onset of asthma, especially in non-atopic children and adults, is less conclusive. The current study aimed to evaluate the effects of size-fractioned PM on lung immune responses in healthy BALB/c mice. METHODS AND PRINCIPAL FINDINGS: We collected PM10, PM2.5, PM1 and PM0.1 samples from October 2012 to August 2013 in the Taipei Basin. These PM samples were representative of urban traffic pollution. The samples were extracted and sonicated in phosphate-buffered saline (PBS). Female BALB/c mice were exposed to the samples via intratracheal instillation at three different doses: 1.75 mg/kg (35 µg/per mouse), 5 mg/kg (100 µg/per mouse), and 12.5 mg/kg (250 µg/per mouse). The mice were exposed on days 0 and 7, and PBS alone was used as a control. Following the exposures, the expression profiles of inflammatory cells and cytokines in bronchoalveolar lavage fluid (BALF) were assessed. Exposure to PM10 resulted in inflammatory responses, including the recruitment of neutrophils and the induction of T helper 1 (Th1) cell-related cytokine release, such as TNF-α and IFN-γ. Furthermore, an allergic immune response, including the recruitment of eosinophils and the up-regulation of T helper 2 (Th2) cell-related cytokine release, such as IL-5 and IL-13, was also observed in the BALF of mice exposed to PM10. CONCLUSIONS: Our study showed that exposure to PM alone caused mixed Th1/Th2 inflammatory responses in healthy mice. These findings support the hypothesis that PM may contribute to the onset of asthma.
Subject(s)
Asthma/immunology , Particulate Matter/toxicity , Th1 Cells/immunology , Th2 Cells/immunology , Air Pollutants/toxicity , Animals , Asthma/chemically induced , Bronchoalveolar Lavage Fluid , Female , Interleukin-13/metabolism , Interleukin-5/metabolism , Mice , Mice, Inbred BALB C , Th1 Cells/drug effects , Th2 Cells/drug effectsABSTRACT
The thickness-dependent surface states of MoS2 thin films grown by the chemical vapor deposition process on the SiO2-Si substrates are investigated by X-ray photoelectron spectroscopy. Raman and high-resolution transmission electron microscopy suggest the thicknesses of MoS2 films to be ranging from 3 to 10 layers. Both the core levels and valence band edges of MoS2 shift downward â¼0.2 eV as the film thickness increases, which can be ascribed to the Fermi level variations resulting from the surface states and bulk defects. Grainy features observed from the atomic force microscopy topographies, and sulfur-vacancy-induced defect states illustrated at the valence band spectra imply the generation of surface states that causes the downward band bending at the n-type MoS2 surface. Bulk defects in thick MoS2 may also influence the Fermi level oppositely compared to the surface states. When Au contacts with our MoS2 thin films, the Fermi level downshifts and the binding energy reduces due to the hole-doping characteristics of Au and easy charge transfer from the surface defect sites of MoS2. The shift of the onset potentials in hydrogen evolution reaction and the evolution of charge-transfer resistances extracted from the impedance measurement also indicate the Fermi level varies with MoS2 film thickness. The tunable Fermi level and the high chemical stability make our MoS2 a potential catalyst. The observed thickness-dependent properties can also be applied to other transition-metal dichalcogenides (TMDs), and facilitates the development in the low-dimensional electronic devices and catalysts.
ABSTRACT
Cortico-basal ganglia circuits are critical for speech and language and are implicated in autism spectrum disorder, in which language function can be severely affected. We demonstrate that in the mouse striatum, the gene Foxp2 negatively interacts with the synapse suppressor gene Mef2c. We present causal evidence that Mef2c inhibition by Foxp2 in neonatal mouse striatum controls synaptogenesis of corticostriatal inputs and vocalization in neonates. Mef2c suppresses corticostriatal synapse formation and striatal spinogenesis, but can itself be repressed by Foxp2 through direct DNA binding. Foxp2 deletion de-represses Mef2c, and both intrastriatal and global decrease of Mef2c rescue vocalization and striatal spinogenesis defects of Foxp2-deletion mutants. These findings suggest that Foxp2-Mef2C signaling is critical to corticostriatal circuit formation. If found in humans, such signaling defects could contribute to a range of neurologic and neuropsychiatric disorders.
Subject(s)
Autism Spectrum Disorder/genetics , Forkhead Transcription Factors/metabolism , Neural Pathways/metabolism , Repressor Proteins/metabolism , Vocalization, Animal/physiology , Animals , Basal Ganglia/metabolism , Communication , Corpus Striatum/metabolism , Learning/physiology , MEF2 Transcription Factors/genetics , Mice, TransgenicABSTRACT
Zinc oxide nanoparticles (ZnO NPs) have been widely used in industry. The metal composition of PM2.5 might contribute to the higher prevalence of asthma. To investigate the effects of ZnO NPs on allergic airway inflammation, mice were first exposed to different concentrations of ZnO NPs (0.1 mg/kg, 0.5 mg/kg) or to a combination of ZnO NPs and chicken egg ovalbumin (OVA) by oropharyngeal aspiration on day 0 and day 7 and then were sacrificed 5 days later. The subsequent time course of airway inflammation in the mice after ZnO NPs exposure was evaluated on days 1, 7, and 14. To further determine the role of zinc ions, ZnCl2 was also administered. The inflammatory cell count, cytokine levels in the bronchoalveolar lavage fluid (BALF), and lung histopathology were examined. We found significant neutrophilia after exposure to high-dose ZnO NPs on day 1 and significant eosinophilia in the BALF at 7 days. However, the expression levels of the T helper 2 (Th2) cytokines IL-4, IL-5, and IL-13 increased significantly after 24h of exposure to only ZnO NPs and then decreased gradually. These results suggested that ZnO NPs could cause eosinophilic airway inflammation in the absence of allergens.
Subject(s)
Asthma/pathology , Eosinophils/drug effects , Lung/drug effects , Metal Nanoparticles/chemistry , Zinc Oxide/analysis , Animals , Asthma/physiopathology , Bronchoalveolar Lavage Fluid , Chickens , Chlorides/chemistry , Dose-Response Relationship, Drug , Female , Immunoglobulin E/blood , Immunoglobulin E/immunology , Inflammation/pathology , Lung/pathology , Mice , Mice, Inbred BALB C , Ovalbumin/chemistry , Ovum , Particulate Matter , Th2 Cells/cytology , Zinc Compounds/chemistryABSTRACT
Camouflage is the primary defense behavior in cephalopods. It is known that cuttlefish immediately after hatching are capable of showing various body patterns for concealing themselves, however recent studies suggest that maturation of camouflage body patterns is faster for cuttlefish (Sepia officinalis) reared in enriched environments than those reared in impoverished environments. Since camouflage patterning in cephalopods is predominately visually driven, this study specifically investigates effects of the rearing background contrast on the maturation of body patterns in cuttlefish (Sepia pharaonis). Newly hatched animals were separated into two cohorts, one reared in a uniform-gray background (low-contrast, or L group) and the other raised in a black/white checkerboard background (high-contrast, or H group). At Weeks 2, 4, 6, 8, 10, and 12, cuttlefish were placed individually either on uniform or checkerboard substrates to examine their body patterns. Animals from both L and H groups appear to show moderate disruptive patterns on the checkerboard and less disruptive on the uniform background at Week 2. Throughout development, however, cuttlefish from the H group showed stronger disruptive patterns than that of the L group on the checkerboard background at Weeks 10 and 12. In interesting findings, cuttlefish from both L and H groups showed similar strength but different disruptive components on the uniform background in later postembryonic stages. These results suggest that the maturation of camouflage body patterns in S. pharaonis is at least in part affected by visual contrast of their rearing backgrounds, although environmental complexity or social interaction is also likely to be involved in this process. This also implies that early visual experience could exert its effect on the seemingly preprogrammed behaviors such as camouflage body patterning in cephalopods.