Clinical features and mortality-related factors of extensive burns among young adults: the Kunshan disaster experience.

BACKGROUND: The aim of the study was to identify the clinical features and the factors associated with burn induced mortality among young adults after exposure to indoor explosion and fire. METHODS: This is an observational study which included burn patients who were admitted to eighteen ICUs after a fire disaster. Epidemiologic and clinical characteristics, as well as therapy were recorded. The primary outcome was 90-day mortality. The mortality-related factors were also analyzed. RESULTS: There were 167 burn patients enrolled in the study, the median age was 38 years, 62 (37.1%) patients died within 90 days. Seventy-one percent of patients had a burn size ≥90% TBSA, and 73.7% of patients had a full-thickness burn area above 50% TBSA. The survivors had lower Baux scores, and received earlier escharectomy and autologous skin grafts. The 50% mortality rates (LA50s) for burn size and full-thickness burn area were 95.8% and 88.6% TBSA, respectively. The multivariate analysis showed that full-thickness burn area over 50% TBSA and residual burned surface area (RBSA)/TBSA at 28 days were strong predictors of mortality among burn patients (odds ratio 2.55; 95% CI, 1.01 to 6.44, P=0.047; odds ratio 1.07; 95% CI, 1.04 to 1.09, P<0.001). The ROC curve-based cut-off values of RBSA/TBSA at 28 days for predicting 90-day mortality were 62.5%. CONCLUSIONS: Burn size and full-thickness burn area were the main risk factors for poor outcome in patients with extensive burns. Earlier escharectomy and autologous skin grafts may improve outcomes.

Direct Observation of Corner States in Second-Order Topological Photonic Crystal Slabs.

Recently, higher-order topological phases that do not obey the usual bulk-edge correspondence principle have been introduced in electronic insulators and brought into classical systems, featuring in-gap corner or hinge states. In this Letter, using near-field scanning measurements, we show the direct observation of corner states in second-order topological photonic crystal slabs consisting of periodic dielectric rods on a perfect electric conductor. Based on the generalized two-dimensional Su-Schrieffer-Heeger model, we show that the emergence of corner states roots in the nonzero edge dipolar polarization instead of the nonzero bulk quadrupole polarization. We demonstrate the topological transition of two-dimensional Zak phases of photonic crystal slabs by tuning intracell distances between two neighboring rods. We also directly observe in-gap one-dimensional edge states and zero-dimensional corner states in the microwave regime. Our work presents that the photonic crystal slab is a powerful platform to directly observe topological states and paves the way to study higher-order photonic topological insulators.

A silicon-on-insulator slab for topological valley transport.

Backscattering suppression in silicon-on-insulator (SOI) is one of the central issues to reduce energy loss and signal distortion, enabling for capability improvement of modern information processing systems. Valley physics provides an intriguing way for robust information transfer and unidirectional coupling in topological nanophotonics. Here we realize topological transport in a SOI valley photonic crystal slab. Localized Berry curvature near zone corners guarantees the existence of valley-dependent edge states below light cone, maintaining in-plane robustness and light confinement simultaneously. Topologically robust transport at telecommunication is observed along two sharp-bend interfaces in subwavelength scale, showing flat-top high transmission of ~10% bandwidth. Topological photonic routing is achieved in a bearded-stack interface, due to unidirectional excitation of valley-chirality-locked edge state from the phase vortex of a nanoscale microdisk. These findings show the prototype of robustly integrated devices, and open a new door towards the observation of non-trivial states even in non-Hermitian systems.

Clinical significance of preoperative liver stiffness measurements in primary HBV-positive hepatocellular carcinoma.

AIM: To analyze clinical significance of preoperative liver stiffness measurement (LSM) by FibroScan in postcurative resection hepatitis B virus (HBV) related hepatocellular carcinoma (HCC). PATIENTS & METHODS: A total of 263 patients underwent preoperative LSM and curative operation for primary HBV-positive HCC were enrolled. The correlation between preoperative LSM and survival was analyzed. RESULTS: All patients were stratified into two groups using the optimal cut-off value (13.2 kPa) of LSM using the receiver-operating characteristic. Patients with an LSM ≥13.2 kPa had poorer overall survival (median, 61.3 vs 48.2 months, hazard ratio: 0.15; p = 0.009) and recurrence-free survival (median, 60.4 vs 47.0 months; hazard ratio: 0.32; p = 0.011) than patients with an LSM <13.2 kPa and LSM also have been confirmed as independent predictor for survival for HCC. DISCUSSION: This could potentially guide patient stratification and individualized treatment. CONCLUSION: Preoperative LSM can be considered as an independent prognostic factor for HBV-positive HCC after curative resection.

In silico analysis of the effect of mutation on epidermal growth factor receptor in non-small-cell lung carcinoma: from mutational analysis to drug designing.

Tyrosine kinase inhibitors (TKI)-resistant mutation in epidermal growth factor receptor's (EGFR) kinase domain is an important anomaly to look into. Studying the mutations at atomic level using molecular dynamics simulations gave us an insight into the architectural changes happening at the microscopic level. The knowledge was used to design new TKI whose function is devoid of the affect of the mutations in kinase domain. Traditional Chinese medicinal library was used for structure-based drug designing, where virtual screening was followed by ADME/Tox analysis and the shortlisted compounds were docked into the kinase domain of EGFR and simulated there using atomic-level selection of the grid. The shortlisted compounds from molecular docking analysis were subjected to MM-PBSA calculations. The in silico data generated is giving a strong lead compound for further in vitro and in vivo analysis.

Proposal for achieving in-plane magnetic mirrors by silicon photonic crystals.

Magnetic mirrors exhibit predominant physical characteristics such as high surface impedance and strong near-field enhancement. However, there is no way to implement these materials on a silicon lab chip. Here, we propose a scheme for an in-plane magnetic mirror in a silicon-based photonic crystal with a high-impedance surface, in contrast to the previous electric mirrors with low surface impedance. A tortuous bending waveguide with zero-index core and magnetic mirror walls is designed that exhibits high transmission and zero phase change at the waveguide exit. This type of magnetic mirror opens the door to exploring the physics of high-impedance surfaces and applications in integrated photonics.

Full Polarization Conical Dispersion and Zero-Refractive-Index in Two-Dimensional Photonic Hypercrystals.

Photonic conical dispersion has been found in either transverse magnetic or transverse electric polarization, and the predominant zero-refractive-index behavior in a two-dimensional photonic crystal is polarization-dependent. Here, we show that two-dimensional photonic hypercrystals can be designed that exhibit polarization independent conical dispersion at the Brillouin zone center, as two sets of triply-degenerate point for each polarization are accidentally at the same Dirac frequency. Such photonic hypercrystals consist of periodic dielectric cylinders embedded in elliptic metamaterials, and can be viewed as full-polarized near zero-refractive-index materials around Dirac frequency by using average eigen-field evaluation. Numerical simulations including directional emissions and invisibility cloak are employed to further demonstrate the double-zero-index characteristics for both polarizations in the photonic hypercrystals.

[Study on the Supercontinuum Generation with Femtosecond Pulse in Photonic Crystal Fiber].

Physical mechanism of supercontinuum generation in photonic crystal fiber by femtosecond laser pulse has been investigated experimentally. In this study, we used the tunable output wavelength Ti: sapphire optical parametric amplifier as the pump source and the fiber spectrometer acquired the spectrogram of supercontinuum generation in photonic crystal fiber under different power and wavelength conditions, then we normalized the spectrograms and make a comparison of them. PCF supercontinuum differences affected by physical mechanisms were analyzed. We found that when increasing the incident pump pulse power, the spectral width will be gradually widened, there are more peaks, part of the energy will transfer in to the short-wave- length region; as long as it reaches a certain intensity, width of supercontinuum finally saturated, the shape of supercontinuum was also stabilized. As the incident power was settled at 300 milliwatt and the length of PCF was settled at 105 millimeter, experimental results show that width and shape of supercontinuum are affected by the wavelength of pump pulse, in the range of 760 to 840 nm, there appears more and more peaks with the increase of incident wavelength; at anomalous dispersion the spectrogram of supercontinuum generation will be more flat and more wider as the wavelength of pump pulse closer to zero point.

Unusual method for phenolic hydroxyl bridged lanthanide CPs: syntheses, characterization, one and two photon luminescence.

A "basophilic method" for phenolic hydroxyl bridged lanthanide coordination polymers (CPs) was developed. With this method, eleven CPs with the general formula of [Ln(HL1)L1·H(2)O](n) (Ln = Tb (1), Nd (2), Eu (3), Gd (4), La (5), Er (6), Y (7), H(2)L1 = 4-methyl salicylic acid) and [Ln(HL2)L2·2MeOH](n) (Ln = Eu (8), Tb (9), Gd (10), La (11), H(2)L2 = 3-hydroxy-2-naphthoic acid) were synthesized based on two ligands, and five of them (1-4 and 8) were characterised by X-ray single crystal diffraction. The powder X-ray diffraction patterns (PXRD) of complexes showed that 1-7 are isostructural, 8-11 are isostructural. Furthermore, 1 was characterised by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), elemental analysis (EA), one and two photon luminescence were investigated in detail.

A versatile Tb(III) complex for picosecond filamentation, a transparent thin film and a supramolecular gel.

The first complex picosecond filament, namely a filament of terbium(III) p-hydroxybenzoate, is observed. The filament is the only example of Ln(III) ion two-photon absorption in a complex. A transparent, colorless and mechanically robust thin film, as well as a supramolecular gel, of this complex are prepared in a facile manner and exhibit strong luminescence. The thin film is characterized in detail by XRD, SEM, UV-vis, luminescence spectroscopy and lifetime.

[Time-resolved photoluminescence of stimulated emission from ZnO nanoparticles].

The detailed room-temperature stimulated emission including its optical characteristics from nanosized ZnO particles prepared by homogenous precipitation method was investigated by time-resolved spectroscopy both from the frequency domain and time domain. As the excitation power was increased, sharp lasing peaks with the full width at half maximum less than 0.5 nm, similar to the FP lasing mode resonator mode, emerged rapidly from the emission spectra. Additionally, a narrow emission line intensity increased rapidly with increasing the excitation intensity, which was due to an exciton-exciton collision recombination, and the threshold excitation intensity was 7.2 GW x cm(-2). Upon higher excitation power, the lasing mechanism switched to electron-hole plasma (EHP). The EHP emission in the case of a higher excitation intensity appeared at a lower energy side of the E-E emission and replaced completely the E-E emission at the higher intensity. The EHP emission was red-shifted when further increasing the excitation intensity, compared to the E-E emissions. It was demonstrated that the red-shift of the EHP peak was attributed to the relevant band gap renormalization effect in the electron-hole plasma regime. At the same time, the emission lifetime was drastically reduced. Time-resolved spectrum of P band suggested a Gaussian-like decay time with only a few tens of picoseconds, compared to 2 ps, which is the limit of streak camera time resolution. The dynamic processes of lasing behavior and characteristics of the lasing emission in ZnO nanoparticles could be valuable and provide the information on crystal quality, exciton and lasing action in ZnO.

[Time resolved photoluminescence of ZnO nanoparticles under low photon energy excitation].

Time-resolved photoluminescence (TRPL) and time-integrated photoluminescence (TIPL)measurements were performed at ZnO nanoparticles with grain size from 17 nm to 110 nm prepared by homogenous precipitation method (HPM). With a quasi-continuous picoseconds laser excitation at a low photon energy of 2. 33 eV (wavelength 532 nm)from a Vanguard 2000-HM532 laser, ultrafast emission with the wavelength ranging from 550 to 1000 nm was detected. It was observed that the wavelength position of all the peaks of the samples regularly redshifted with the increase in the particle sizes. The PL spectra were fitted with Gaussian curves, in which a good fitting consisting of four Gaussian peaks was obtained. The Gaussian analysis indicates that the redshift in PL is due to the increased relative magnitude of the Gaussian combination in the low energy region. The analysis of the experiment suggests the existence of surface states in the bad gap near Fermi level of ZnO. At the same time, a strong dependence of the PL lifetime on grain size was found. Upon the increase in particle size, the decay of the emission shortened much, in which the PL intensity reveals bi-exponential decay for samples with small diameters while no identified decay of emission was observed within 2 nanoseconds for large particles. The dependence of the decay time on the grain size of nanoparticles can be suitably attributed to the surface related mechanism. Combined analysis of the lifetime dependence on particle size validates the model of surface states recombination in nanostructures due to large surface-to-volume ratio.

[Surface emission characteristics of ZnO nanoparticles].

The size-dependence of photoluminescence (PL) of ZnO nanoparticles with diameter from 17 to 300 nm was demonstrated by time resolved laser spectroscopy. Broad PL spectra were obtained and found to consist of three Gaussian components. The authors found that the PL peak position and relative amplitude depend on the size of nanoparticles for the Gaussian PL band inside the energy band-gap. The Gaussian band Xc3 is believed to be associated with the transitions between surface states. It is well known that as the dimensions of a semiconductor are reduced to the nanometer scale, one of the key features is the large surface-to-volume ratio. The larger surface-to-volume ratio in nanostructures means the larger bulk density of dangling bonds. The existence of dangling bond in a crystal surface is likely to change a state localized by splitting the state out of the border of the energy gap. The Gaussian peak Xc3 lying inside the band gap of ZnO indicates the existence of such initial states in the forbidden bulk band gap. Furthermore, we found that with the decrease in particle size, the Gaussian curve Xc3 shifts to the lower energy. With the particle size increaseing, the comparative amplitude of PL band Xc3 descends rapidly and so does the corresponding relative PL intensity. The sensitive correlation between the particle size and the optical properties of the below gap broadband shows a key role of the surface states recombination in PL of nanosized particles. Furthermore, our exploration indicates that the surface states recombination plays a dominant role in PL of nanostructures with particle sizes down to a certain degree.

[Quantitative measurement of Fe(II) in human blood with spectral analysis method].

Since the absorption spectra of Fe(II) ions solutions vary with the concentration of Fe(II) irons, the authors tried to establish a direct measurement of active haemachrome in human blood through spectral analysis, and successfully made an experiment on it. The authors prepared Fe(II) ions solutions with various concentrations chemically, using 1, 10-phenanthroline (phen) as chromogenic agent. After the absorption spectra of these solutions were analyzed, Gaussion fitting at absorption peaks was performed to them. The linear fitting figure showed that the areas of Gaussion fitting curves correspond to the concentrations of Fe(II) irons. Thus, the concentration of Fe(II) in human blood was figured out in this way, and the result fitted quite well the actual concentration. As an optimized method, this creative idea is more accurate and precise. It will probably contribute to the development of new devices for measuring Fe(II) ions in human blood.

[Photoluminescence of one dimension ZnO single crystal columns array excited by different space variation direction].

Highly-oriented single crystal ZnO columns array was prepared by a simple two-step evaporation oxidation method. And the photoluminescence properties of different direction excitation were investigated. Upon different direction excitation, the emission spectra were greatly different. Besides the relative intensity of different emission peak of PL changed; some new emission peaks werealso detected at high excitation power. This showed that the energy absorption, transmission and emission in one dimension ZnO column array were directional. The up-conversion polarized photoluminescence spectra were also found, and the intensities of 400 nm emission peak were affected by the laser polarization orientation. These results showed that the intensity and shape of PL were related with the direction and polarization of the excitation laser. The results also give some important references for subminiature one dimension line array optoelectric device.

Studies on the Time-Resolved Polarized Fluorescence of R-Phycoerythrin Crystal from Red Alga Porphyra yezoensis.

The time-resolved polarized fluorescence of oriented R-phycoerythrin single crystal from red alga Porphyra yezoensis was studied in picosecond time scale. The fluorescence decay of the crystal exhibited two exponential processes, one of which was related to the energy transfer and excitation equilibrium between chromophores (tau(1)