Dynamics of breathers-like circular Pearcey Gaussian waves in a Kerr medium

We introduce the propagation properties of the circular Pearcey Gaussian (CPG) waves in Kerr medium for the first time. The breathers-like structure and breathers-like groups structure (filamentions) of CPG waves will form due to the interaction between the linear waves and the nonlinear medium. The focusing characteristics in Kerr medium can be adjusted by the deviation factor and the initial input power of the CPG waves. By choosing appropriate input power, the imaginary part of the CPG waves can split into some wavelets during the propagation. It is worth noting that the distinctive stepwise focusing of the imaginary part of the CPG waves which can be applied to wave modulation. Furthermore, the numerical experiment results show good agreement with the numerical simulation results.

Propagation of the radially polarized Airy vortex beams in uniaxial crystals orthogonal to the optical axis

We introduce the radially polarized Airy vortex beams (RPAiVBs) and analytically study their propagation in uniaxial crystals orthogonal to the optical axis. We mainly discuss the effects of the vortex and the ratio of the extraordinary index (n_e) to the ordinary index (n_o) on the propagation properties of the RPAiVBs involving the intensity distributions, the maximum intensity, the radiation forces, the trajectory, and the velocity. The RPAiVBs evolve into the beams produced by the x direction electric field (RPAiXVB) and the y direction electric field (RPAiYVB). It is shown that with the increase in the order of the vortex, the maximum intensity and the radiation forces of the RPAiVBs are greatly enhanced; besides, the intensity focusing position of the RPAiVBs is farther. Furthermore, with the ratio of n_e to n_o increasing, the trajectory of the RPAiXVBs is farther from x=0  mm, and the acceleration is bigger in the x-z plane, but they are opposite in the y-z plane.

Streptococcus mutans transcriptome in the presence of sodium fluoride and sucrose

OBJECTIVE

Considering the diverse mechanisms by which fluoride could affect oral bacteria, this study evaluated the effect of sodium fluoride onStreptococcus mutans transcriptome in the presence of sucrose.

METHODS

S. mutans UA159 was cultured in 3 different types of media: medium control[TY], sucrose control[TY_S], and sodium fluoride sucrose test[TY_S_NaF]. Triplicates of each group were sampled at exponential phase 3 h after inoculation, total RNA was isolated, mRNA enriched and cDNA paired-end sequenced (Illumina Hi-Seq2500).

RESULTS

Genes related toS. mutans adhesion(gtfB and gtfC), acidogenicity and sugar transport were up-regulated in the presence of sucrose(TY_S) and sucrose/fluoride(TY_S_NaF), whereas gene dltA, D-alanine-activating enzyme, which is related to regulation of non-PTS sugar internalization was down-regulated. Up-regulation of the scrA gene and the PTS fructose-and mannose system, as well as functions such as those involved in stress and defence responses and peptidases; and down-regulation of lacACDG and pyruvate formate-lyase were observed in the TY_S_NaF group, as compared to TY_S group.

CONCLUSIONS

The presence of NaF has decreased the overall gene expression level inS. mutans. However, its major effect seems to be the inducing of expression of genes involved in some PEP:PTS systems and other metabolic transporters which imply specific cellular internalisation of sugars.

Dentist-related factors influencing the use of vital pulp therapy: a survey among dental practitioners in China

Objective

To evaluate dentist-related factors associated with the use of vital pulp therapy (VPT) for the treatment of pulp exposures in permanent teeth.

Methods

This survey-based study sent an online questionnaire to collect data on the demographics of the respondents, the use of VPT and the choice of materials for VPT, to all members of the Society of Endodontology of Guangdong, China.

Results

A total 183 of 380 members responded (48.2%). The majority (89.6%; 164 of 183) had performed direct pulp capping (DPC) while 55.2% (101 of 183) had performed partial pulpotomy (PP) at least once. The most-cited reason for not performing VPT was unfamiliarity with the technique. Mineral trioxide aggregate was the most commonly used material for both DPC (67.1%; 110 of 164) and PP (73.3%; 74 of 101). Endodontists, compared with general practitioners, preferred to perform DPC and chose calcium silicate materials (CSMs) for VPT (odds ratios 5.81 and 8.07, respectively). DPC and CSMs for VPT were also favoured more by respondents who had practised for > 5 years. Senior respondents were more likely to use PP.

Conclusions

Speciality, years of practise and age of dentists influenced the decision making and the choice of materials for VPT. Continuing education is essential to promote the clinical use of VPT.

Statistical properties of partially coherent radially and azimuthally polarized rotating elliptical Gaussian beams in oceanic turbulence with anisotropy

A new class of partially coherent radially and azimuthally polarized rotating elliptical Gaussian (PCRPREG and PCAPREG) beams is introduced. The analytical expressions of the PCRPREG and PCAPREG beams propagating through anisotropy oceanic turbulence are derived based on the extended Huygens-Fresnel principle and the spatial power spectrum of oceanic turbulence. The effects of beam waist size w₀, coherence width σ₀, propagation distance z and oceanic turbulence parameters on the evolution statistics properties of PCRPREG and PCAPREG beams are studied in detail by numerical simulation. Our results indicate that with the increase of the propagation distance in the far field region, the normalized initial profile with a doughnut-like distribution of PCRPREG and PCAPREG beams gradually converts into a flat-topped one, and finally evolves into a Gaussian-like beam profile. We also find that the salinity-induced turbulence fluctuation makes a greater contribution to the decrease of beam quality compared with the temperature-induced turbulence fluctuation. Furthermore, the full width at half maximum becomes wider for the larger propagation distance z and wavelength λ or the smaller dissipation rate ε. Our work will pave the way for the development of underwater optical communication and underwater laser radar in oceanic environment.

A novel non-enzymatic H2O2 sensor using ZnMn2O4 microspheres modified glassy carbon electrode

With a facile solvothermal technique, ZnMn₂O₄ microspheres were synthesized in this work, which were used as enzyme mimics for the electrocatalytic reduction of H₂O₂. The morphology, crystal phase and structure of the ZnMn₂O₄ microspheres underwent characterization under X-ray diffraction spectroscopy, Raman spectroscopy, energy-dispersive spectroscopy, and scanning electron microscopy. The synthesized ZnMn₂O₄ microspheres showed an average diameter of 2 μm with great crystallinity, and exhibited excellent catalytical activity towards H₂O₂ electroreduction in alkaline media. The glassy carbon electrode modified by ZnMn₂O₄ microspheres showed a linear amperometric response for H₂O₂ in a wide concentration range of 0.02 ˜ 15 mM with detection limit of 0.13 μM under the optimized conditions. Besides, the sensor proposed here was successfully used to determine H₂O₂ in milk, suggesting that ZnMn₂O₄ microspheres can be used for non-enzymatic electrochemical sensor applications.

Propagation properties of autofocusing off-axis hollow vortex Gaussian beams in free space

By solving the (2 + 1) dimensional Schrödinger equation in free space, we find that the autofocusing off-axis hollow vortex Gaussian beams (HVGBs) are analytically derived for the first time. The off-axis HVGBs can be adjusted by changing the off-axis coordinate (x0,y0) and topological charge n₂. In particular, by increasing the off-axis coordinate (x0,y0), the self-focusing intensity can be increased. Besides, the self-focusing property can be more obvious. Furthermore, by increasing the hollow order n₁, we can deepen the depth of focus, make the focus position further away, and increase the self-focusing intensity too. We also discuss other propagation properties that are used to enrich the autofocusing off-axis HVGBs, such as Poynting vector, angular momentum, gradient force, and maximum scattering force during propagation.

Abruptly autofocused and rotated circular chirp Pearcey Gaussian vortex beams

In this Letter, we introduce a new class of abruptly autofocued and rotated circular chirp Pearcey Gaussian vortex beams (AARCCPGVBs) which tend to abruptly autofocused circular chirp Pearcey vortex beams or chirp Gaussian vortex beams by adjusting the spatial distribution factors. Different from other rotated beams [Opt. Lett.31, 694 (2006) OPLEDP0146-959210.1364/OL.31.000694 and Opt. Lett.31, 2199 (2006)OPLEDP0146-959210.1364/OL.31.002199], the AARCCPGVBs are autofocused abruptly, maintain a low rotating speed before the focal point, and rotate abruptly and quickly in the focal point. Further, the position of the focal point in the propagating direction can also be controlled by adjusting the chirp factor.

Singular properties generated by finite periodic PT-symmetric optical waveguide network

In this work we investigate the extraordinary characteristics of one-dimensional (1D) finite periodic parity-time (PT) symmetric network. On the basis of the transfer matrix method, three simple expressions are analytically obtained for transmission, left reflection and right reflection coefficients. For this periodic structure, we provide new criteria for the PT-symmetry breaking transition in terms of the elements of the transfer matrix and the scattering matrix. These criteria indicate that the exceptional points are related only to the cell structure, but not to the cell number. Utilizing these criteria and expressions, the relationships between the transmittances (reflectances) and the cell number are considered in detail. Furthermore, the conditions for ultrastrong transmission are analytically derived. We also show how a PT-symmetric network can become unidirectionally and bidirectionally transparent at specific frequencies. The conditions and related properties of unidirectional and bidirectional transparencies are also examined. Finally, we find that the finite periodic PT-symmetric network with certain cell number can be viewed as a unidirectionally invisible structure at the exceptional points. Our work may pave the way for designing a diversefamily of optical structures and networks with new properties and functionalities.

A novel hydrogen peroxide sensor based on electrodeposited copper/cuprous oxide nanocomposites

Copper/cuprous oxide nanocomposites were electrodeposited on a fluorine doped tin oxide (FTO) glass substrate for sensitive determination of hydrogen peroxide.

Nonparaxial propagation of abruptly autofocusing circular Pearcey Gaussian beams

We introduce a new class of abruptly autofocusing circular Pearcey Gaussian beams (AAFCPGBs) which tend to be abruptly autofocusing circular Pearcey beams with a small distribution factor, or Gaussian beams with a larger distribution factor. The nonparaxial propagation of the AAFCPGBs is investigated by numerical calculation. The radiation force of the AAFCPGBs exerted on a Rayleigh particle is analyzed in detail.

Similar Effect of P16 Hydroxymethylation and True Methylation on Prediction of Malignant Transformation of Oral Epithelial Dysplasia: A Prospective Study

Background: Total P16 methylation (P16M), including P16 hydroxymethylation (P16H) and true-P16M, correlates with malignant transformation of oral epithelial dysplasia (OED). Both true-P16M and P16H are early events in carcinogenesis. Aim: The aim of this study is to prospectively determine if discrimination of true-P16M from P16H similarly is necessary for prediction of cancer development from OEDs. Methods: Patients (n = 265) with mild or moderate OED were recruited into the double-blind 2-center cohort. Total-P16M and P16H were analyzed using the 115-bp MethyLight, TET-assistant bisulfite (TAB) methylation-specific PCR (MSP), and TAB-sequencing. Total-P16M-positive and P16H-negative samples were defined as true-P16M-positive. Progression of OEDs was monitored for a minimum 24 months follow-up period. Results: P16H was detected in 23 of 73 (31.5%) total-P16M-positive OEDs. Follow-up information was obtained from 247 patients with an ultimate compliance of 93.2%. OED-derived squamous cell carcinomas were observed in 13.0% (32/247) patients during the follow-up (median, 41.0 months). The cancer progression rate for total-P16M-positive patients was significantly increased when compared with total-P16M-negative patients (23.3% vs 8.6%; adjusted odds ratio = 2.67 [95% CI: 1.19-5.99]). However, the cancer progression rate was similar between P16H- and true-P16M-positive OEDs (26.1% [6/23] vs 22.0% [11/50]; odds ratio = 0.80 [95% CI: 0.22-2.92]). The progression-free survival was also similar for these patients. Conclusion: P16H and true-P16M are similar biomarkers for determining malignant potential of OEDs. Discrimination of P16H from true-P16M, at least in OED, may be not necessary in clinical applications.

Three-dimensional localized chirped Airy-circular wave packets in free space

By solving the (3+1)-dimensional free-space Schrödinger equation in circular cylindrical coordinates, we have systematically analyzed the propagation of chirped Airy-circular (CAiCi) wave packets. The complex amplitude of the CAiCi wave packets is constructed by the Airy function, the Gaussian function, and the confluent hypergeometric function. We find that the CAiCi wave packets are some coaxial ring pulses stacked along the temporal domain in the initial position, which are modulated by the chirped factor, the initial velocity, the distribution factor, and the propagation distance. Meanwhile, the wave packets will appear to undergo intensity attenuation, diffusion, convergence, and so on. We can also modulate the shape of the wave packets and change their optical properties by altering the mode numbers. Furthermore, we analyze the evolution properties of the wave packets in detail from the aspects of the gradient force, the scattering force, phase, the Poynting vector, and the angular momentum, and find some interesting phenomena.

Second-order statistics of a partially coherent electromagnetic rotating elliptical Gaussian vortex beam through non-Kolmogorov turbulence

Based on the extended Huygens-Fresnel principle, analytical formulas for the cross-spectral density matrix elements of a partially coherent electromagnetic rotating elliptical Gaussian vortex (PCEREGV) beam through non-Kolmogorov turbulence are derived and the corresponding second-order statistics are investigated numerically. The numerical calculations of the PCEREGV beam are first developed to validate the correctness of the analytical results. Our findings show that the transverse spectrum density with an initially elliptical annular shape splits into two light spots during the beam propagation. By choosing appropriate parameters of the beam and the turbulence, we can maximize the spectrum density and control the spectral states of coherence and polarization so as to alleviate the influence of the turbulent atmosphere effectively.

Focusing properties of circle Pearcey beams

We introduce a new class of (2+1) dimensional circle Pearcey beams (CPBs) with the abruptly autofocusing (AAF) characteristics. Compared with circular Airy beams, CPBs can increase the peak intensity contrast, shorten the focus distance and, especially, eliminate the oscillation after the focal point. Furthermore, we discuss the influence of the optical vortices (including on-axis, off-axis, and vortex pairs) on the light intensity distribution of the CPBs during propagating.

[Clinicpathological features and survival of patients with AIDS related non-Hodgkin's lymphoma]

目的

分析艾滋病相关非霍奇金淋巴瘤（ARL）患者的临床特征及生存状态。

方法

回顾性分析53例ARL患者的临床资料，按1∶2随机配对对照研究方法，以106例普通非霍奇金淋巴瘤（NHL）患者为对照，比较两组患者的生存率。

结果

53例ARL患者的平均年龄为43（11~67）岁，诊断NHL时CD4⁺T细胞中位数为（146±20）个/µl。53例患者中B细胞来源者47例（88.7%），T细胞来源者6例（11.3%）。Ann Arbor分期Ⅲ~Ⅳ期者占52.8%（28/53）；IPI评分中高危组和高危组患者比例分别为45.3%（24/53）和18.9%（10/53）。ARL诊断后放弃治疗者占37.7%（20/53），抗HIV治疗联合放化疗者占62.3%（33/53）。抗NHL治疗采用CHOP（环磷酰胺、长春新碱、表阿霉素、泼尼松）方案。ARL组患者的总生存（OS）时间显著短于对照组[（6.0±1.3）对（48.0±10.0）个月，P<0.05]。接受抗NHL治疗的患者中，ARL组（33例）和对照组（100例）患者的OS时间差异无统计学意义[（48.0±10.9）对（77.0±11.1）个月，P=0.816]；ARL组患者1年OS率低于对照组（60.6%对83.0%，P<0.05），但两组患者的2年（53.5%对60.5%）、3年（48.1%对45.9%）和5年（39.1%对27.5%）OS率差异均无统计学意义（P值均>0.05）。

结论

ARL多见于青壮年，1年内病死率高，抗HIV治疗联合CHOP方案抗NHL治疗能显著改善ARL患者预后。

Antimicrobial photodynamic therapy - what we know and what we don't

Considering increasing number of pathogens resistant towards commonly used antibiotics as well as antiseptics, there is a pressing need for antimicrobial approaches that are capable of inactivating pathogens efficiently without the risk of inducing resistances. In this regard, an alternative approach is the antimicrobial photodynamic therapy (aPDT). The antimicrobial effect of aPDT is based on the principle that visible light activates a per se non-toxic molecule, the so-called photosensitizer (PS), resulting in generation of reactive oxygen species that kill bacteria unselectively via an oxidative burst. During the last 10-20 years, there has been extensive in vitro research on novel PS as well as light sources, which is now to be translated into clinics. In this review, we aim to provide an overview about the history of aPDT, its fundamental photochemical and photophysical mechanisms as well as photosensitizers and light sources that are currently applied for aPDT in vitro. Furthermore, the potential of resistances towards aPDT is extensively discussed and implications for proper comparison of in vitro studies regarding aPDT as well as for potential application fields in clinical practice are given. Overall, this review shall provide an outlook on future research directions needed for successful translation of promising in vitro results in aPDT towards clinical practice.

Paraxial propagation dynamics of the radially polarized Airy beams in uniaxial crystals orthogonal to the optical axis

We study the paraxial propagation of the radially polarized Airy beams (RPAiBs) in uniaxial crystals orthogonal to the optical axis analytically and numerically. The propagation trajectory, the intensity and the radiation forces of the RPAiBs are investigated and the properties are elucidated by numerical examples in this paper. Results show that the RPAiBs evolve into the beams produced by the x-direction electric field (RPAiXBs) and the y-direction electric field (PRAiYBs) which are totally different in uniaxial crystals. During the propagation, the intensity of the RPAiXBs transfers from the side lobe in the x-direction to the main lobe and finally returns to the side lobe in the x-direction again, but that of the RPAiYBs transfers from the side lobe in the y-direction to the main lobe and flows to the side lobe in the x-direction at last. The effect of the intensity focusing for the RPAiXBs can be modulated by the ratio of the extraordinary index (ne) to the ordinary index (no) in anisotropic medium, which contributes to the intensity focusing of the RPAiBs in a short distance a lot. We can adjust the intensity distribution especially the focusing position, the propagation trajectory and the radiation forces distributions of the RPAiXBs through choosing an appropriate value of the ratio of ne to no to meet the actual usage accordingly.