Near-unity quantum yield and long-term emission stability in halide perovskite nanocrystal glass composite.

Metal halide perovskites are promising optoelectronic materials due to their outstanding luminescent properties. However, the instability of perovskites has long been the bottleneck to their practical applications. Here Cs4PbBr6 nanocrystals based glass composite (Cs4PbBr6 NCs@glass) are successfully prepared, which displays green emission color (520 nm), narrow bandwidth (23 nm) and a near-unity photoluminescence quantum yield (PLQY). The H2O molecules permeating in the lattice of Cs4PbBr6 were found to be a crucial role in the subband energy emission. The Cs4PbBr6 NCs@glass has excellent emission stability; maintains 93 % of initial PL intensity after ultraviolet light irradiation for over 5000 h. In addition, by adjusting the halogen content, we have achieved tunable emission color from blue (450 nm) to green (520 nm) and red (670 nm) on Cs4PbX6 NCs@glass (X = Cl, Br, I), which covers up to 127 % of the National Television Systems Board (NTSC) standard system. Our finding indicates the commercial applications of perovskite materials in lighting and display.

Intrinsic Self-Trapped Excitons in Graphitic Carbon Nitride.

Graphitic carbon nitrides (g-C3N4) as low-cost, chemically stable, and ecofriendly layered semiconductors have attracted rapidly growing interest in optoelectronics and photocatalysis. However, the nature of photoexcited carriers in g-C3N4 is still controversial, and an independent charge-carrier picture based on the band theory is commonly adopted. Here, by performing transient spectroscopy studies, we show characteristics of self-trapped excitons (STEs) in g-C3N4 nanosheets including broad trapped exciton-induced absorption, picosecond exciton trapping without saturation at high photoexcitation density, and transient STE-induced stimulated emissions. These features, together with the ultrafast exciton trapping polarization memory, strongly suggest that STEs intrinsically define the nature of the photoexcited states in g-C3N4. These observations provide new insights into the fundamental photophysics of carbon nitrides, which may enlighten novel designs to boost energy conversion efficiency.

Enhancing the Photoluminescence and Electroluminescence of Graphitic Carbon Nitride via Atomic and Molecular Co-modification.

Graphitic carbon nitride (g-CN) materials exhibit attractive optoelectronic physical properties; however, their low photoluminescence quantum yields (PLQYs) limit their applications in luminescent devices. Here, boron-doped aromatic carbon nitride (B-PhCNx) was synthesized for the first time via direct thermal polymerization of 2,4-diamino-6-phenyl-1,3,5-triazine and boric acid. The impact of B doping and phenyl modifying on the structural and optical characteristics of the samples was investigated in detail. The highest PLQY of 40.7% was achieved in B-PhCN20, which is 6.8 times that of pristine carbon nitride (p-CN). The B-PhCN20-based light-emitting diode demonstrates a maximum luminance of 1494 cd m-2 and a maximum external quantum efficiency of 1.03%, which are 3.5 and 4.9 times that of the p-CN-based device, respectively. Our findings will provide a reference for rationally designing low-cost and high-performance carbon-nitride-based optoelectronic devices.

A warm-white light-emitting diode based on single-component emitter aromatic carbon nitride.

Artificial lighting consumes almost one-fifth of global electricity. As an efficient solid-state lighting technology, white light-emitting diodes (WLEDs) have received increasing attention. However, the white luminescence of the traditional WLEDs comes from multi-component emitters, which leads to complex device structure and unstable emitting color. Therefore, developing single-component materials with white-light electroluminescence is of significance for artificial lighting applications. Here, we fabricate single-component white-light electroluminescence devices based on an aromatic carbon nitride material and improve the performance of WLEDs by adjusting the carrier transport. The carbon nitride LEDs emit warm-white light, of which color coordinates and color temperature are (0.44, 0.52) and 3700 K. The optimized LEDs display a very low turn-on voltage of 3.2 V and achieve a milestone in the maximum luminance and external quantum efficiency of 1885 cd m-2 and 1.20%. Our findings demonstrate the low-cost carbon nitride materials have promising potential for single-component WLEDs application.

Association between sensitized to food allergens and childhood allergic respiratory diseases in Taiwan.

BACKGROUND: Sensitization to allergen has long been known to be relate to childhood allergic diseases. Polysensitised children have more severe atopic diseases, whereas allergic rhinitis or asthma children with cosensitized to food and inhalant allergens were under-researched. OBJECTIVE: To realize the association between sensitization to food allergens and pediatric allergic rhinitis and asthma in Taiwan. METHODS: We included 138 participants with sensitized to allergen as assessed by serum-specific IgE. 87 of 138 participants had allergic rhinitis and 51 participants had asthma. All participants underwent a physical examination and measurement of serum total and specific IgE values. Besides, nasal peak expiratory flow rate (nPEFR) that was performed by the participants with allergic rhinitis and were requested to complete the Pediatric Rhinoconjunctivitis Quality of Life Questionnaires (PRQLQ). Lung function test and asthma control test (ACT)/child asthma control test (C-ACT) were performed by the participants with asthma. RESULTS: 39 of 87 allergic rhinitis participants with sensitized to food and inhalant allergens (AR food group), 48 of 87 allergic rhinitis participants with sensitized to inhalant allergen alone (AR inhalant group). The AR food group had significantly lower nPEFR values and higher total IgE values (p < 0.05) compared with the AR inhalant group. The AR food group had higher PRQLQ scores than the AR inhalant group. 24 of 51 asthma participants with sensitized to food and inhalant allergens (Asthma food group), 27 of 51 asthma participants with sensitized to inhalant allergen alone (Asthma inhalant group). The Asthma food group had significantly higher total IgE values (p < 0.05) compared with the Asthma inhalant group. The Asthma food group had lower lung function test values and asthma control test (ACT) scores than the other group. CONCLUSIONS: Children with cosensitized to food and inhalant allergens have more severe clinical symptoms and abnormal laboratory findings. Sensitization to food allergen was more related to pediatric allergic rhinitis than asthma. We may need larger, longer and extended studies to confirm these findings.

A review of eight cases of cavernous sinus thrombosis secondary to sphenoid sinusitis, including a12-year-old girl at the present department.

Cavernous sinus thrombosis (CST) is a severe disease which can result from infection of any of the tissues drained by the cavernous sinus. We here review eight cases, including a 12-year-old girl, all secondary to sphenoid sinusitis. The clinical manifestations, laboratory data, imaging findings, pathogens, medications, surgical treatment and clinical outcomes were analyzed. All eight patients had headache and five of them fever. All cases were associated with one or more ophthalmic symptoms. In four cases, computed tomography/magnetic resonance imaging showed isolated sphenoid sinusitis. In three cases, streptococci were isolated from blood culture and two cases showed Staphylococcus aureus in blood and sinus cultures. In seven cases, surgery was undertaken. All eight subjects received antibiotics, and 5 were administered intravenous ceftriaxone and metronidazole. Six subjects received anticoagulation therapy and one received corticosteroids. No mortality was recorded. Three cases showed sequelae, including Lemierre syndrome, ophthalmic complaints, and cranial nerve paralysis. In conclusion, the management of CST should include intravenous antibiotic therapy, combined with endonasal sinus surgery.

Efficacy of nasal irrigation in the treatment of acute sinusitis in atopic children.

BACKGROUND: Nasal irrigation has been used as adjunctive therapy for sinonasal disease but is under-researched in children. The study aim was to evaluate the effectiveness of nasal irrigation with normal saline in the management of acute sinusitis in atopic children. METHODS: We enrolled 60 atopic children with acute sinusitis, of whom 29 received nasal irrigation with normal saline and 31 did not receive nasal irrigation. All participants underwent a nasal peak expiratory flow rate (nPEFR) test, a nasal smear examination, and radiography (Water's projection) and were requested to complete a Pediatric Rhinoconjunctivitis Quality-of-Life Questionnaire (PRQLQ) during the baseline visit. All participants were requested to record symptoms in a daily diary and were followed up at 1-week intervals. A physical examination, nasal smear, and nPEFR were performed at each visit, and all daily diaries were collected. At the final visit (after 3 weeks), the symptom diaries were reviewed and participants were requested to complete the PRQLQ again. nPEFR, radiography, and a nasal smear were also repeated. RESULTS: There were significant improvements in mean PRQLQ and nPEFR values (p < 0.05) for the irrigation compared to the non-irrigation group. There was no significant difference in radiographic findings between the groups (p > 0.05). The irrigation group recorded significant improvements in eye congestion, rhinorrhea, nasal itching, sneezing, and cough symptoms compared with the non-irrigation group. CONCLUSION: Nasal irrigation is an effective adjunctive treatment for acute sinusitis in atopic children.

A trial of adding Lactobacillus johnsonii EM1 to levocetirizine for treatment of perennial allergic rhinitis in children aged 7-12 years.

BACKGROUND: Supplementary consumption of probiotics may temporarily alter the intestinal microflora of infants and children, thereby preventing and treating allergic disorders. OBJECTIVE: To compare the clinical efficacy of levocetirizine with that of levocetirizine plus Lactobacillus johnsonii EM1 (Lj EM1) for treating perennial allergic rhinitis (PAR) in children. METHODS: Sixty-three children aged 7-12 years fulfilled the entry criteria for the study and had moderate to severe PAR of at least 1 year's duration. The treatment followed a randomized, open-label crossover design: all subjects were randomized to 2 crossover treatment regimens of levocetirizine with Lj EM1 (group 1) or levocetirizine alone (group 2) for 12 weeks; subsequently, treatments were reversed for a further 12 weeks. The effects of the 2 regimens were compared using the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and the total symptom score (TSS) from diary cards. The parameters evaluated were nasal peak expiratory flow rate (nPEFR), FVC, FEV1, serum immunoglobulin E (IgE), mite-specific IgE, eosinophilic cationic protein (ECP), resistin, blood eosinophils, eosinophil percentage in nasal smears, IL-4, IL-10, interferon-γ (IFN-γ), and transforming growth factor-ß (TGF-ß). RESULTS: After the first 12 weeks of treatment, TSS in both groups had improved progressively compared with that in the run-in period. Both groups had improved TSS at weeks 4, 8, and 12 (P<0.05), and group 1 was more efficacious than group 2 at week 4 (P=0.014), week 8 (P=0.011), and week 12 (P<0.009). During the second 12-week period, group 2 showed continual and progressive improvement, while group 1 did not. The PRQLQ scores were significantly decreased in both groups (P<0.05), but there was no statistically significant difference between the 2 groups (P=0.446). The eosinophil percentage in nasal smears decreased in both groups compared with that in the run-in period, and significant differences were detected in groups 2 and 1at 16 and 24 weeks of treatment, respectively (P<0.05). Both groups showed significant improvement in nPEFR at weeks 4, 8, 12, 16, and 24 (P<0.01), and the treatment for group 1 appeared to be more efficacious than that for group 2 at weeks 12, 16, and 20 (P<0.05). FVC and FEV1 were improved in both groups at weeks 8 through 24 (P<0.05), but there was no significant difference between the 2 groups. In cytokine measurements, IFN-γ and IL-10 increased significantly and IL-4 decreased significantly in both groups, while elevation of TGF-ß was seen only in group 1 at 12 weeks (P<0.001). However, the difference in TGF-ß disappeared after 24 weeks treatment. There was no difference in serum resistin levels. No serious adverse events were recorded in either treatment group. CONCLUSION: The 24-week, 2-phase, crossover treatment program showed that levocetirizine plus Lj EM1 was more effective for PAR than levocetirizine and that this difference persisted for at least 3 months after discontinuation of Lj EM1.

Clinical spectrum of acute rhinosinusitis among atopic and nonatopic children in Taiwan.

BACKGROUND: Rhinitis and sinusitis are very common medical conditions and have been shown to be frequently associated. The role of allergies in the pathogenesis of chronic rhinosinusitis has been confirmed; however, the role of allergies in acute rhinosinusitis is debatable. Nonetheless, allergies are an important factor in the development of rhinosinusitis. OBJECTIVE: To evaluate the incidence of allergic rhinitis in patients with acute rhinosinusitis and identify the clinical spectrum in Taiwan. METHODS: This study randomly recruited 69 participants between 3 and 12 years of age with acute rhinosinusitis over the period of one and a half years. All participants underwent a nasal peak expiratory flow rate (nPEFR) test, skin-Prick test (SPT), nasal smear examination, nasal culture, radiography (Water's projection) and were requested to complete the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) as well as provide their allergic history. RESULTS: Among the 69 participants in the study, 27 (39.1%) participants were shown to have allergic rhinitis. The most troublesome symptoms among the 69 participants with acute rhinosinusitis were postnasal drip (3.00 ± 1.29), nasal obstruction (2.94 ± 1.39) and cough (2.67 ± 1.42). The most troublesome symptoms among the 27 participants with acute rhinosinusitis combined with allergic rhinitis were nasal obstruction (3.33 ± 1.24), postnasal drip (3.22 ± 1.09) and itchy eyes (2.74 ± 1.43) and with the higher values. In addition, the participants (≧ 6 y/o) with acute rhinosinusitis combined with allergic rhinitis had significantly lower nPEFR values compared with the nonatopic children (75.2 ± 18.2 vs 96.6 ± 21.4, p<0.05). If nPEFR is below 75 mL/min, the positive predict value in the patients of acute rhinosinusitis is 75.0% combined with allergic rhinitis (sensitivity 63.2%; specificity 85.7%). Streptococcus pneumoniae (29.0%), Haemophilus influenzae (20.3%), and Moraxella catarrhalis (17.4%) were the major isolated pathogens in this study. The prevalence of colonization with Staphylococcus aureus in the 69 participants with acute rhinosinusitis was 23.2%, and 15.9% for methicillin-resistant S. aureus (MRSA). CONCLUSION: This study demonstrated that the bacteriological properties of acute rhinosinusitis among children in Taiwan are the same as those in other parts of the world; however, the prevalence of colonization by MRSA was higher than among healthy children. Second, atopic children were more likely to develop acute rhinosinusitis than nonatopic children. Third, most Taiwanese children with acute rhinosinusitis complained of postnasal drip, nasal obstruction and cough. If a child suffering from acute rhinosinusitis complained of severe nasal obstruction (nPEFR≦75 mL/min), the doctor should be alerted to atopic conditions requiring further treatment. The issues dealt with in this study may require further research with a larger sample population over an extended period of time to verify these conclusions.

Efficacy of nasal irrigation in the treatment of acute sinusitis in children.

BACKGROUND: Nasal irrigation has been used as an adjunctive therapy of sinonasal disease including acute/chronic sinusitis and allergic rhinitis. Several published articles reported it also improves clinical sinus symptoms. OBJECTIVE: To evaluate the effectiveness of normal saline nasal irrigation in the management of acute sinusitis in children. DESIGN: This was a randomized, prospective placebo-controlled study. METHODS: We included 69 participants with acute sinusitis. 30 of 69 participants underwent normal saline nasal irrigation. 39 of 69 participants were not receiving nasal irrigation. All participants performed nasal peak expiratory flow rate (nPEFR) test, nasal smear examination, radiography (Water's projection) and requested to complete the Pediatric Rhinoconjunctivitis Quality of Life Questionnaires (PRQLQ) at the baseline visit. All participants were requested to record the symptom diary card every day and were followed-up every 1 week during this period. A physical examination, nasal smear and nPEFR were performed at each visit, and all daily diary cards collected. At the final visit, the symptoms diaries were reviewed and participants were requested to complete the PRQLQ again. The nPEFR, radiography (Water's projection) and nasal smear were also repeated. RESULTS: Normal saline irrigation group significantly improved mean PRQLQ values and nPEFR values at medium (T=2.816, P<0.05) and final period (T=2.767, P<0.05) compared with the other group. Although there were no statically significant improving rate of radiography (Water's projection) in among two groups (T=0.545, P>0.05), but normal saline irrigation group was better than the other group. The improval rate of mean TSS in the irrigation group significantly improved all symptoms compared with the placebo group, in which rhinorrhea, nasal congestion, throat itching, cough and sleep quality improved. 27 of 66 (40.9%) participants with atopy, 16 of 27 (53.33%) participants underwent normal saline irrigation. Normal saline irrigation atopy group significantly improved rhinorrhea, nasal congestion, throat itching and sleep quality symptoms compared with non-irrigation atopy group. Normal saline irrigation atopy group significantly improved nPEFR values at final period (Z=2.53, P<0.05). CONCLUSION: This study evidence that normal saline nasal irrigation improves Pediatric Rhinoconjunctivitis Quality of Life and decreases acute sinusitis symptoms. Nasal irrigation is an effective adjunctive treatment for pediatric acute sinusitis. Normal saline nasal irrigation in atopy children also improves allergic-related symptoms. We may need larger, longer and extended study to assess the conclusion.