A Colloidal-Quantum-Dot Integrated U-Shape Micro-Light-Emitting-Diode and Its Photonic Characteristics.

A special micro LED whose light emitting area is laid out in a U-like shape is fabricated and integrated with colloidal quantum dots (CQDs). An inkjet-type machine directly dispenses the CQD layer to the central courtyard-like area of this U-shape micro LED. The blue photons emitted by the U-shape mesa with InGaN/GaN quantum wells can excite the CQDs at the central courtyard area and be converted into green or red ones. The U-shape micro LEDs are coated with Al2O3 by an atomic layer deposition system and exhibit moderate external quantum efficiency (6.51% max.) and high surface recombination because of their long peripheries. Low-temperature measurement also confirms the recovery of the external quantum efficiency due to lower non-radiative recombination from the exposed surfaces. The color conversion efficiency brought by the CQD layer can be as high as 33.90%. A further continuous CQD aging test, which was evaluated by the strength of the CQD emission, under current densities of 100 A/cm2 and 200 A/cm2 injected into the micro LED, showed a lifetime extension of the unprotected CQD emission up to 1321 min in the U-shape device compared to a 39 min lifetime in the traditional case, where the same CQD layer was placed on the top surface of a squared LED.

A novel fibrinogen γ-chain frameshift mutation, p. Cys365Phefs*41, causing hypofibrinogenemia with bleeding phenotype in a Chinese family.

BACKGROUND: Congenital hypofibrinogenemia is a rare bleeding disease that is classified as the quantitative deficient type. In the present study, investigated the relationship between the genotype and phenotype in a family with hypofibrinogenemia. METHODS: The proband was aware of a predisposition to bleeding. Functional analysis was performed for her all family members, including coagulation function tests, thrombus molecular markers, thromboelastography, scanning electron microscopy, DNA sequencing, and high-performance liquid chromatography-mass spectrometry (HPLC-MS). Pathogenicity analysis and protein modeling of mutant amino acids were also performed. RESULTS: A novel heterozygous mutation in c.1094delG was detected in FGG exon 8, which resulted in p. Cys365Phefs*41 (containing the signal peptide) in the proband and her mother, who showed a corresponding decrease in fibrinogen function and levels. Thromboelastography indicated that the strength of their blood clots decreased and they had an increased risk of bleeding. The proband fibrin network structure was looser than healthy controls, with large pores in the network, which increased the permeability of lytic enzymes. Results of HPLC-MS showed a lack of mutant peptide chain expression in their plasma, indicating that the family had congenital hypofibrinogenemia, with a clinical phenotype that is related to the degree of fibrinogen deficiency. The mutation truncated the γ-peptide chain and destroyed the functional structure of fibrinogen, including the γ352Cys-γ365Cys disulfide bond. The truncated peptide chains may also lead to nonsense-mediated decay. CONCLUSIONS: The mutation induced a structural change at the carboxyl-terminal of the fibrinogen molecule, leading to fibrinogen secretion dysfunction.

Behavioural and chronic toxicity of fullerene to Daphnia magna: Mechanisms revealed by transcriptomic analysis.

Extensive application of fullerene nanoparticles (nC60) leads to potential environmental pollution. The acute toxic effects of nC60 have been largely investigated, but studies of behavioural and chronic toxicity at sublethal doses are still rare and the underlying molecular mechanisms remain unknown. The present study investigated behavioural and chronic toxicity of nC60 to Daphnia magna. The results showed that, in response to nC60 exposure, hopping, heartbeat frequencies and feeding ability of D. magna decreased significantly, displaying negative relationship with exposure time and dose. Chronic treatments with 0.1 mg/L or 1 mg/L nC60 for 21 days significantly reduced survival and reproduction of D. magna. These harmful effects suggested negative impacts of nC60 on aquatic ecosystems. Moreover, transcriptome analysis showed that the behavioural and chronic toxicity of nC60 to D. magna might be related to physiological functions such as cell structural repair, protein degradation, energy metabolism and reproduction. We found that nC60 accumulated in guts of D. magna, which should be responsible for the decrease of food ingestion and consequently inhibiting energy intake. Deficiency of energy not only affects behaviours but also declines reproduction in D. magna. Overall, this is the first study comprehensively considered the behavioral and chronic toxicity of nC60 to aquatic organism. The results should be helpful to better understand the ecological consequences of C60 released into water environments.

Mechanisms underlying the acute toxicity of fullerene to Daphnia magna: Energy acquisition restriction and oxidative stress.

The toxicity of fullerene (C60) to Daphnia magna has been a subject with increasing concerns. Nevertheless, the underlying mechanisms are still poorly understood. In the present study, we evaluated various aspects of the toxicological impacts of C60 on daphnia. After a 72-h exposure, the 50% effective concentration of C60 was 14.9 mg/L for immobilization, and 16.3 mg/L for mortality. Daphnia exhibited a quick uptake of C60 with a body burden value of 413 µg/g in wet weight in the 1 mg/L C60 treatment group. Transmission electron microscopy observations revealed that C60 had mainly accumulated in the guts of organisms. The feeding rate, gut ultra-structural alterations, and digestive enzyme activities of daphnia in response to C60 treatment were evaluated. The results revealed a significant reduction in the digestion and filtration rates, as well as gut impairment and inhibition of digestive enzymes (cellulose, amylase, trypsin, and ß-galactosidase) activity of C60 exposed daphnia. In addition, the changes in superoxide dismutase (SOD) and malondialdehyde (MDA) levels in daphnia under C60 exposures were also discovered. These results, for the first time, provide systematic evidence that C60 caused a restriction in energy acquisition and increased oxidative damage in daphnia, which might be related to the bioaccumulation of C60 and finally led to the immobility and mortality.

TiO2 nanoparticles in the marine environment: Physical effects responsible for the toxicity on algae Phaeodactylum tricornutum.

Nanoscale titanium dioxide (nTiO2) has been widely used in cosmetics, catalysts, varnishes, etc., which is raising concerns about its potential hazards to the ecosystem, including the marine environment. In this study, the toxicological effect of nTiO2 on the marine phytoplankton Phaeodactylum tricornutum was carefully investigated. The results showed that nTiO2 at concentrations ≥20mg/L could significantly inhibit P. tricornutum growth. The 5-day EC50 of nTiO2 to P. tricornutum growth is 167.71mg/L. Interestingly, nTiO2 was found to exert its most severe inhibition effects on the first day of exposure, at a lower EC50 of 12.65mg/L. During the experiment, nTiO2 aggregates were found to entrap algae cells, which is likely responsible for the observed toxic effects. Direct physical effects such as cell wall damage from the algae entrapment were confirmed by flow cytometry and TEM imaging. Moreover, low indirect effects such as shading and oxidative stress were observed, which supported the idea that direct physical effects could be the dominant factor that causes nTiO2 toxicity in P. tricornutum. Our research provides direct evidence for the toxicological impact of nTiO2 on marine microalgae, which will help us to build a good understanding of the ecological risks of nanoparticles in the marine environment.

Left-Sided Appendicitis in an Elderly Patient with Midgut Malrotation.

Appendicitis is a common surgical abdominal disease with various presentations. Its diagnosis may be obscured by asymptomatic congenital anatomical anomalies like midgut malrotation. Midgut malrotation is a rare fetal anomaly resulting from incomplete or failure of midgut rotation and fixation. It is mostly presented with bowel obstruction or volvulus in early life. Presentation in adult is rare. Here, we report an elderly patient presented with left lower abdominal pain and urinary tract infection. Abdominal computed tomography revealed left-sided appendicitis with non-rotational-type midgut malrotation. Clinicians should bear in mind the possibility of underlying midgut malrotation, as appendicitis could be the first presentation of this rare congenital condition.

Conductive and transparent multilayer films for low-temperature TiO2/Ag/SiO2 electrodes by E-beam evaporation with IAD.

Conductive and transparent multilayer thin films consisting of three alternating layers (TiO2/Ag/SiO2, TAS) have been fabricated for applications as transparent conducting oxides. Metal oxide and metal layers were prepared by electron-beam evaporation with ion-assisted deposition, and the optical and electrical properties of the resulting films as well as their energy bounding characteristics and microstructures were carefully investigated. The optical properties of the obtained TAS material were compared with those of well-known transparent metal oxide glasses such as ZnO/Ag/ZnO, TiO2/Ag/TiO2, ZnO/Cu/ZnO, and ZnO/Al/ZnO. The weathering resistance of the TAS film was improved by using a protective SiO2 film as the uppermost layer. The transmittance spectra and sheet resistance of the material were carefully measured and analyzed as a function of the layer thickness. By properly adjusting the thickness of the metal and dielectric films, a low sheet resistance of 6.5 ohm/sq and a high average transmittance of over 89% in the 400 to 700 nm wavelength regions were achieved. We found that the Ag layer played a significant role in determining the optical and electrical properties of this film.