Experimental and theoretical investigation of 2D nanoplatelet-based conversion layers for color LED microdisplays.

In the field of augmented reality, there is a need for very bright color microdisplays to meet the user specifications. Today, one of the most promising technology to manufacture such displays involves a blue micro-LED technology and quantum dots-based color conversion layers. Despite recent progress, the external power conversion efficiencies (EPCE) of these layers remain under ∼25%, below the needs (>40%) to reach a white luminance of 100,000 cd/m2. In this work, we have synthesized CdSexS1-x nanoplatelet-based conversion layers for red and green conversion, and measured their absorption properties and EPCE performances with respect to layer thickness. On this basis, a model was developed that reliably predicts the layer EPCE while using only few input data, namely the layer absorption coefficients and the photoluminescence quantum yield (PLQY) of color photoresist. It brings a new insight into the conversion process at play at a micro-LED level and provides a simple method for extensive optimization of conversion materials. Finally, this study highlights the outstanding red conversion efficiency of photoresist layers made of core-double shell CdSexS1-x nanoplatelets with 31% EPCE (45% external PLQY) for 8 µm-thick conversion layer.

Anti-HMGB1 neutralizing antibody ameliorates neutrophilic airway inflammation by suppressing dendritic cell-mediated Th17 polarization.

We demonstrate that high mobility group box 1 protein (HMGB1) directs Th17 skewing by regulating dendritic cell (DC) function. First, our in vitro studies reveal that recombinant HMGB1 (rHMGB1) activates myeloid DCs to produce IL-23 in vitro, and rHMGB1-activated DCs prime naïve lymphocytes to produce the Th17 cytokine IL-17A. Second, we demonstrate that anti-HMGB1 neutralizing antibody attenuates HMGB1 expression, neutrophilic inflammation, airway hyperresponsiveness, and Th17-related cytokine secretion in vivo by using a murine model of neutrophilic asthma induced by ovalbumin (OVA) plus lipopolysaccharide (LPS). Furthermore, anti-HMGB1 neutralizing antibody decreases the number of Th17 cells in lung cells and suppresses the production of IL-23 by lung CD11C(+) APCs. Finally, we show that intranasal adoptive transfer of rHMGB1-activated DCs was sufficient to restore lung neutrophilic inflammation and the Th17 response in a DC-driven model of asthma, whereas the transfer of rHMGB1 plus anti-HMGB1-treated mDCs significantly reduced these inflammation phenotypes. These data suggest, for the first time, that HMGB1 drives the DC-polarized Th17-type response in allergic lung inflammation and that blocking HMGB1 may benefit the attenuation of neutrophilic airway inflammation in asthma.

Novel liposomes composed of dimyristoylphosphatidylcholine and trehalose surfactants inhibit the growth of tumor cells along with apoptosis.

Novel liposomes composed of L-α-dimyristoylphosphatidylcholine (DMPC) and trehalose surfactant (DMTre) were produced and inhibitory effects of DMTre on the growth of human colon carcinoma (HCT116) and gastric carcinoma (MKN45) in vitro were examined. The remarkably high inhibitory effects of DMTre on the growth of HCT116 and MKN45 cells were obtained without affecting the growth of normal cells. The thickness of fixed aqueous layer of DMTre was larger than that of DMPC liposomes and increased in a dose-dependent manner. The induction of apoptosis by DMTre was revealed on the basis of flow cytometric analysis. DMTre induced apoptosis through the activation of caspases and mitochondria via Bax. It is noteworthy that remarkable inhibitory effects of DMTre on the growth of human colon and gastric carcinoma cells leading to apoptosis were obtained for the first time.

Psychological distress and mental health service contact of unaccompanied asylum-seeking children.

BACKGROUND: Evidence is emerging that psychological problems, particularly symptoms of depression and post-traumatic stress disorder, are more prevalent in unaccompanied asylum-seeking children (UASC) than their accompanied peers. However, little is known about help seeking and mental health service (MHS) utilization in this group, and how this relates to their psychological needs. This study aims to describe the level of psychological distress among a group of UASC and the pattern of MHS contact. METHOD: Socio-demographic data on 71 UASC residing in London was obtained and self-report questionnaires were completed regarding trauma events (Harvard Trauma Questionnaire), general psychological distress [Strengths and Difficulties Questionnaire (SDQ)], post-traumatic stress symptoms (Impact of Event Scale), depressive symptoms (Birleson Depression Self-Rating Scale for Children) and contact with MHS (Attitudes to Health and Services Questionnaire). RESULTS: UASC were mainly male (n = 48, 67.6%), Black African (n = 39, 54.9%) and their median age was 17 years (interquartile range = 15; 17). They had been living in the UK for a median of 18 months. Eight (11.3%) scored on the SDQ borderline/abnormal range for total symptoms, but this was 21 (29.6%) using the SDQ emotional subscale. Forty-seven (66.2%) were at high risk for post-traumatic stress disorder and nine (12.7%) at high risk for depressive disorder. Only 12 (17%) had MHS contact. Predictors of MHS contact were depressive symptoms and duration of time in the UK. CONCLUSIONS: UASC had a high level of emotional symptoms, especially post-traumatic stress symptoms. However, only a small proportion of UASC were in contact with MHS. This suggests a high level of MHS under-utilization, and reasons for this are discussed.

[Invasive aspergillosis after near-drowning: case reports and review of the literature].

OBJECTIVE: The purpose of this study was to analyze the clinical presentations and disease courses of invasive aspergillosis (IA) in patients after near-drowning. METHODS: The clinical data of 3 cases of invasive aspergillosis after near-drowning from Oct. 2005 to Aug. 2010 in this hospital were retrospectively analyzed, and the related literature was reviewed. RESULTS: There were 1 male and 2 female patients, aged from 18 to 72 years. All of them had been immunocompetent before drowning. Two patients drowned because of traffic accident, and 1 fell in sewage by accident. All of the 3 patients were intubated because of acute respiratory failure, and received broad-spectrum antibiotic therapy. One had transient leucopenia, and 2 patients received glucocorticoid therapy. The condition of the 3 cases deteriorated 9 to 11 days after near-drowning. Aspergillus was isolated from sputum samples of 2 patients at the same time. Thoracic CT findings included multiple nodules, consolidation and cavity formation. Multiple abscesses in cerebral parenchyma were found in 1 patient with invasive cerebral aspergillosis. One patient died, whose lungs, cerebral parenchyma, myocardium and kidney were all infected by aspergillus. The other 2 patients, whose infection limited to the lungs, had a positive prognosis. Using the terms "aspergillosis" and "near-drowning" a PUBMED search yielded 7 articles, published between 1984 and 2010. Using the terms "invasive pulmonary aspergillosis" and "near-drowning", searching Wangfang data and CHED data, encompass 1 article, published in 2009. In all of the 8 articles, there are 5 final diagnosis cases and 3 clinical diagnosis cases. CONCLUSIONS: IA was very rare in immunocompetent hosts but had been reported in previously healthy individuals after near-drowning. Aspergillosis might develop 1 to 2 weeks after near-drowning, and the prognosis was poor in patients with central nervous system involvement.

Adenosine Triphosphate Promotes Allergen-Induced Airway Inflammation and Th17 Cell Polarization in Neutrophilic Asthma.

Adenosine triphosphate (ATP) is a key mediator to alert the immune dysfunction by acting on P2 receptors. Here, we found that allergen challenge caused an increase of ATP secretion in a murine model of neutrophilic asthma, which correlated well with neutrophil counts and interleukin-17 production. When ATP signaling was blocked by intratracheal administration of the ATP receptor antagonist suramin before challenge, neutrophilic airway inflammation, airway hyperresponsiveness, and Th17-type responses were reduced significantly. Also, neutrophilic inflammation was abrogated when airway ATP levels were locally neutralized using apyrase. Furthermore, ATP promoted the Th17 polarization of splenic CD4+ T cells from DO11.10 mice in vitro. In addition, ovalbumin (OVA) challenge induced neutrophilic inflammation and Th17 polarization in DO11.10 mice, whereas administration of suramin before challenge alleviated these parameters. Thus, ATP may serve as a marker of neutrophilic asthma, and local blockade of ATP signaling might provide an alternative method to prevent Th17-mediated airway inflammation in neutrophilic asthma.

sRAGE alleviates neutrophilic asthma by blocking HMGB1/RAGE signalling in airway dendritic cells.

Receptor for advanced glycation end products (RAGE) plays a role in inflammatory reactions. The soluble form of RAGE (sRAGE) acts as a decoy to inhibit interactions of RAGE with advanced glycation end products such as High mobility group box 1 (HMGB1). We have demonstrated that HMGB1 directs Th17 skewing by regulating dendritic cell (DC) functions in a previous study. However, the protective effects of HMGB1 blockade with sRAGE in the development of neutrophilic asthma remain unclear. Here, we showed that allergen challenge decreased expression of sRAGE in a murine model of neutrophilic asthma, correlating well with neutrophil counts and interleukin (IL)-17 production. When HMGB1 signalling was blocked by intratracheal administration of sRAGE before sensitisation, HMGB1 expression, neutrophilic inflammation, and Th17-type responses were reduced significantly. Anti-asthma effects of sRAGE were achieved by inhibition of RAGE and IL-23 expression in airway CD11c+ antigen-presenting cells. Finally, we showed that sRAGE inhibited Th17 polarisation induced by recombinant HMGB1 (rHMGB1)-activated dendritic cells (DCs) in vitro. Adoptive transfer of rHMGB1-activated DCs was sufficient to restore airway inflammation, whereas transfer of rHMGB1 plus sRAGE-activated DCs significantly reduced neutrophilic inflammation. Thus, sRAGE prevents Th17-mediated airway inflammation in neutrophilic asthma at least partly by blocking HMGB1/RAGE signalling in DCs.

The pulmonary nodule "discovered" by pneumonia: a case report.

The number of patients diagnosed with pulmonary nodules increased as more patients with high risk of lung cancer choose low-dose computed tomography (CT) scans for the screening of cancer. Clinicians might get two questions from the patients: what is the definite diagnosis of the nodule? What should we do? We have already got many guidelines trying to solve these problems. There are also several prediction models for pulmonary nodules. However, guidelines are not suitable for all types of patients, and the reality of patients is more complicated. Here we reported a 58-year-old man with a lung nodule in the right upper lobe, which was occasionally found during a period of pneumonia. We suggested two periods of follow-up, and the patient was also admitted to a clinical trial about circulating tumor cells (CTCs). He finally accepted surgical excision with a pathologic diagnosis of adenocarcinoma. This case suggests that: we might suggest CT surveillance for patients with solid nodules about 8 mm maximum diameter; three-dimensional reconstruction of CT scans could provide more information about the details of nodules; CTCs counts of peripheral blood could be considered as a potential clue for malignancy.

Levels of O6-methylguanine acceptor protein in tissues of rats and their relationship to carcinogenicity and aging.

N-nitroso compounds react with cellular DNA to produce various damaging adducts, one of the more important being O6-alkylguanine. DNA restoration is accomplished by transfer of the alkyl group to a cysteine residue of an acceptor protein. The levels of acceptor activity were compared in several tissues from well-fed and dietary-restricted inbred SD rats 30-1,194 days of age. Striking and consistent differences were found in the levels of acceptor activity in different tissues from both groups; these levels corresponded to their sensitivity to tumorigenesis by alkylating agents. Acceptor activity levels were highest in the liver and somewhat less in the spleen; there were significantly lower levels in brain and kidney. The random loss with time in the integrity of DNA may cause alterations in cellular function or limit cellular proliferation, thus leading to senescence and death. DNA repair processes may alter the rate of accumulation of damage, thereby affecting potential longevity. There were no significant age-associated changes in the ability of cells from either dietary group to remove DNA adducts and there was no evidence of alterations in the acceptor protein with age that would compromise its functional activity.

Recurrent "pneumonia" in left lower lobe lasting for 8 years: a case report.

Bronchioloalveolar carcinoma (BAC) is a unique lung neoplasm with variable forms, such as single nodular, multifocal and lobar pneumonic types. The pneumonic type BAC is often difficult to differentiate from pneumonia. Here we present a case of 63-year-old Chinese male, who had recurrent cough, white sputum with pneumonic lesions in left lower lobe. He suffered from lung biopsies for three times, and finally diagnosed as high differentiated adenocarcinoma 8 years later. He was treated with four cycles of pemetrexed and cisplatin, and four cycles of docetaxel and nedaplatin. However, he did not achieve disease stabilization and is still under follow up. This case suggests that, pneumonic type adenocarcinoma may radiographically and clinically resemble infectious pneumonia. Lack of fever and leukocytosis, no response to antibiotics, air bronchogram, and accompanied nodules or patches in computed tomography (CT) scans should raise suspicion about the diagnosis of pneumonia. Lung biopsy might be the only means of ruling in a diagnosis of BAC.

Towards microfluidic reactors for in situ synchrotron infrared studies.

Anodically bonded etched silicon microfluidic devices that allow infrared spectroscopic measurement of solutions are reported. These extend spatially well-resolved in situ infrared measurement to higher temperatures and pressures than previously reported, making them useful for effectively time-resolved measurement of realistic catalytic processes. A data processing technique necessary for the mitigation of interference fringes caused by multiple reflections of the probe beam is also described.

Evidence that lipid peroxidation products bind to DNA in liver cells.

Three lines of evidence are presented indicating the association of lipid peroxidation products with DNA in liver cells, labeled with [3H]arachidonic acid, in the presence of Fe(2+)-DTPA: (1) the nuclear DNA isolated from treated cells had higher radioactivity, compared to controls and the radioactivity increased with longer incubation times, (2) lipid-DNA adducts with a characteristic fluorescence spectrum were formed during the incubation with Fe(2+)-DTPA; (3) the association of peroxidation products with DNA could be inhibited by vitamin E and BHT. Compared with control DNA, purified lipid-DNA adducts showed a decrease of hyperchromicity and melting point, and partial resistance to hydrolysis by DNase I. On the other hand, the repair test shows that the lipid-DNA adducts in cells were not repaired by 4 h after removal of Fe(2+)-DTPA. A decrease in cell viability and in the activity of O6-alkylguanine acceptor protein was also observed with increasing incubation time. These data suggest that the lipid-DNA association, an oxidative DNA damage, occurs in cells treated by Fe(2+)-DTPA and could result in cytotoxicity if not repaired.

Effect of natural antioxidant tanshinone II-A on DNA damage by lipid peroxidation in liver cells.

Tanshinone II-A (TSII-A) isolated from the root of Salvia miltorrhiza Bunge, a traditional medicine in China, is a derivative of phenanthrenequinone, which is known to have antioxidant properties. In the present study, effects of TSII-A on DNA damage by lipid peroxidation were investigated using liver cells, labeled with [3H] arachidonic acid, in the presence of FeCl2-DTPA. The results show that the nuclear DNA isolated from treated cells had higher radioactivity compared to controls and the radioactivity increased with longer incubation times. Purified lipid-DNA adducts had a characteristic fluorescent spectra and showed a decrease of hyperchromicity and melting point. TSII-A could inhibit the association of peroxidation products with DNA in liver cells and prevent a decrease in cell viability and in the the activity of O6-methylguanine acceptor protein with increasing incubation time. Compared with other antioxidants, TSII-A had a higher inhibitory ratio, which was similar to vitamin E and butylated hydroxy-toluene (BHT), but markedly stronger than NaN3, mannatol, and superoxide dismutase (SOD). These data suggest that TSII-A represents a new and effective antioxidant that inhibits the association of lipid peroxidation products with DNA. Its protective effect may be through breaking the chain reactions of peroxidation by scavenging lipid free radicals, thereby decreasing their cytotoxicity.

Induction of apoptosis and inhibition of human gastric cancer MGC-803 cell growth by arsenic trioxide.

Arsenic trioxide (As2O3), used to treat human diseases for centuries in traditional Chinese medicine, has been identified as a very effective antileukaemic agent, but its effect on solid tumours which could be more suitable for clinical treatment with arsenic compounds is still unknown. In this study, we investigated the in vitro effect of As2O3 at concentrations of 0.01-1 microM against six human malignant cell lines, MGC-803, HIC, MCF-7, HeLa, BEL-7402 and A549 cells. As2O3 inhibited growth and induced apoptosis in these malignant cells at varying degrees, in a time dose-dependent manner. The most marked effects were seen in the gastric cancer cell line, MGC-803. In contrast, minimal growth inhibition and induction of apoptosis occurred in human embryonic pulmonary cells following treatment with As2O3 found at the same concentrations. Changes in intracellular Ca2+, following As2O3 treatment were measured by Ca2+ sensitive fluorescent probe Indo-1/AM in flow cytometric assays. The increase in intracellular Ca2+ correlated with the sensitivity of these cells to As2O3, possibly indicating that a critical intracellular Ca2+ signal transduction pathway could be involved in As2O3-mediated cell-death and its selectivity. The marked sensitivity of MGC-803 cells in vitro suggests that As2O3 may be a potential antigastric cancer agent.

Fold-back tetraplex DNA species in DNase I-resistant DNA isolated from HeLa cells.

A DNase I-resistant DNA species has been isolated and purified from HeLa cells by gel electrophoresis. Our studies indicate that the DNase I-resistant DNA species was about 40-60 bp fragment sizes responding to double-strand DNA marker and has higher guanine content. The image of AFM showed that this species has been assumed to be tetraplex structure according to its apparent width and height. Its CD, UV spectrum also exhibited characteristics similar to some tetraplex structure, which was different from the standard duplex DNA. 32P-labeled probes (TTAGGG)4 and 5'-TGGGGAGGGTGGGGAGGGTGGGGAAGG-3' could be hybridized to purified DNase I-resistant species. All results suggest that the DNase I-resistant DNA species have at least two components, which adopt an intrastrand fold-back DNA tetraplex. Their sequences were similar to human telomere and human c-myc locus (NHE), respectively.

Spectroscopic comparison of different DNA structures formed by oligonucleotides.

Six different nucleic acid structures including duplex, triplex and quadruplex are formed by oligonucleotides. Their structural properties are studied in detail by four spectroscopic techniques, i.e. CD, UV, NMR and fluorescence. Results are: CD Spectra: The common characteristics is a negative band at 240 nm, and the spectra are different from each other in the range 260-300 nm. Many factors such as chain direction, sugar puckering, orientation of the glycosyl bond, base stacking and sequence can effect their conformation and then show diversity and complexity in the spectra. UV Spectra: The UV spectra of all forms are quite similar, all of them exhibit a sharp positive peak around 210 nm and a broad positive band in the region of 240-280 nm. Although the bands are different in absorbance, the spectra are not characteristic enough to distinguish these forms. In addition, their thermal denaturation is also observed by UV spectrum, different melting curves and points are shown and some thermodynamic information is provided. NMR Spectra: Since the G residues in the six samples all participate in hydrogen bond, the imino proton can not exchange with the solvent freely so as to allow an observable resonance to arise. The resonance number and chemical shift will vary with the change in base-pairing number and mode as well as the whole geometry of its molecule. Fluorescence Spectra: The interaction mechanisms between EB and these structures are different. B type duplex and triplex adopt an intercalative mode in which the efficiency of energy transfer is relatively high and the fluorescence of EB can not be quenched easily. While for the parallel duplex, outside binding is predominant in which energy transfer can hardly happen and most of its fluorescence can be quenched. As for the quadruplex, groove binding is possible, so the efficiency of energy transfer is higher than that in outside binding, but lower than that in intercalative binding, and fluorescence is quenched partly.

Branched nanowire based guanine rich oligonucleotides.

Self-assembly and aggregation of guanine rich sequences can provide useful insights into DNA nanotechnology and telomeric structure and function. In this paper, we designed a guanine rich sequence d(GGCGTTTTGCGG). We found that it can form stable structure in appropriate condition and it exhibits an anomalous CD spectra. This structures can be imaged in ambient environment with a Nanoscope III AFM (Digital Instruments). We found it forms branch structure and long multistrand DNA nanowire after incubation at 37 degrees C for 6-12 hours in 25 mM TE (pH=8.0) + 5 mM Mg2+ + 50 mM K+. The ability to self-assemble into branches and long wires not only clearly demonstrate its potential as scaffold structures for nanotechnology, but also give aids to understand telomeric structure further. We have proposed a model to explain how these structures formed.

Direct determination of diene conjugation and deoxyribonucleic acid (DNA) oxidative damage can explain the role of DTPA-Fe(2+)-O2 complex in a linoleic acid-DNA system.

Exposure of linoleic acid to diethylenetriminepentaacetic acid (DTPA)-Fe(2+) complexes resulted in fast diene conjugation and peroxidized products which could further react with deoxyribonucleic acid (DNA) to cause DNA oxidative damage. In this paper, we have detected diene conjugation and DNA oxidative damage in a linoleic acid-DNA model system driven by DTPA-Fe(2+) and found that: 1. in air or oxygen-saturated reaction systems, addition of hydrogen peroxide resulted in a decrease in diene conjugation and double-stranded DNA content, but had no obvious effects on the formation of DNA fluorescent products; 2. in anoxic conditions, addition of hydrogen peroxide had no effect on the formation of diene conjugation and fluorescent products, but resulted in a decrease of double-stranded DNA content; 3. in the presence of DTPA, Fe(3+) did not stimulate the formation of diene conjugation; 4. the formation of diene conjugation and fluorescent products was not inhibited by superoxide dismutase, catalase, sodium benzoate, sodium azide and mannitol. However, these 'scavengers' increased the percentage of double-strand DNA to different degrees. α-tocopherol, but not reduced glutathione (GSH), inhibited the formation of diene conjugates. α-tocopherol and GSH both could reduce the amounts of fluorescent products and DNA strand breaks. Taken together, these data further indicate that chelator-Fe(2+)-O2 complex, a perferryl-type oxidant, is probably an important initiator of lipid peroxidation in the linoleic acid-DNA system.

DNA damage induced by hypocrellin-A photosensitization.

Hypocrellin-A (HC-A) isolated from Hypocrellia bambusae Sacc., is a new and effective photosensitizer. Illumination of sarcoma 180 cells with visible light in the presence of HC-A leads to a decrease in cell viability and 3H-TdR incorporation, causes DNA strand breakage, and results in the selective destruction of guanine moieties in DNA. HC-A photosensitization causes an increase in the theta 260/theta 280 ratio in the circular dichroism spectra of DNA in vitro. Of the four usual 2'-deoxynucleotides illuminated in the presence of HC-A only 2'-deoxyguanylic acid was destroyed.

The involvement of singlet oxygen in copper-phenanthroline/H2O2-induced DNA base damage: a chemiluminescent study.

Copper in the presence of excess 1,10-phenanthroline, a reducing agent, and H2O2 causes DNA base damage as well as strand breakage. We have reported in previous work that a strong chemiluminescence was followed by DNA base damage in this system, which is characteristic of guanine. In the present work, the mechanism of the chemiluminescence was studied. Results show that the luminescence was inhibited by all three classes of reactive oxygen species (*OH, O2-, (1)O2) scavengers to different degrees. Singlet oxygen scavengers showed the most powerful inhibition while the other two classes of scavengers were relatively weaker. The emission intensity in D2O was 3-fold that in H2O. Comparing the effect of scavengers on the luminescence of DNA with that of dGMP, the ratio of inhibition was similar. On the other hand, DNA breakage analysis showed that inhibition by the singlet oxygen scavenger NaN3 of strand breakage was strong and comparable to that of the scavengers of the two oxygen radicals. The results suggest that singlet oxygen may be a major factor for the chemiluminescence of guanine, while DNA strand breakage may be caused by many active species.