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Ting Chen,1,2,* Lei Zhang,3,* Wenhua Huang,3,* Huijun Zong,1,2 Qian Li,3 Yuling Zheng,3 Qingyu Lv,3 Decong Kong,3 Yuhao Ren,3 Yongqiang Jiang,3 Yan Li,1,2 Peng Liu3 1The PLA 307 Clinical College of Anhui Medical University, The Fifth Clinical Medical College of Anhui Medical University, Hefei, People’s Republic of China; 2Department of Critical Care Medicine, The Fifth Medical Center, Chinese PLA General Hospital, Beijing, 100071, People’s Republic of China; 3State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yan Li, The PLA 307 Clinical College of Anhui Medical University, The Fifth Clinical Medical College of Anhui Medical University, Hefei, 230032, People’s Republic of China, Email liyanmdhuxi@163.com Peng Liu, Beijing Institute of Microbiology and Epidemiology, Dongdajie Road 20, Beijing, 100071, People’s Republic of China, Tel +86-010-66948487, Email ammsliupeng@163.comBackground: The early identification of pathogens and their antibiotic resistance are essential for the management and treatment of patients affected by ventilator-associated pneumonia (VAP). However, microbiological culture may be time-consuming and has a limited culturability of many potential pathogens. In this study, we developed a rapid nanopore-based metagenomic next-generation sequencing (mNGS) diagnostic assay for detection of VAP pathogens and antimicrobial resistance genes (ARGs).Patients and Methods: Endotracheal aspirate (ETA) samples from 63 patients with suspected VAP were collected between November 2021 and July 2022. Receiver operating characteristic (ROC) curves were established to compare the pathogen identification performance of the target pathogen reads, reads percent of microbes (RPM) and relative abundance (RA). The evaluation of the accuracy of mNGS was performed comparing with the gold standard and the composite standard, respectively. Then, the ARGs were analyzed by mNGS.Results: ROC curves showed that RA has the highest diagnostic value and the corresponding threshold was 9.93%. The sensitivity and specificity of mNGS test were 91.3% and 78.3%, respectively, based on the gold standard, while the sensitivity and specificity of mNGS test were 97.4% and 100%, respectively, based on the composite standard. A total of 13 patients were virus-positive based on mNGS results, while the coinfection rate increased from 27% to 46% compared to the rate obtained based on clinical findings. The mNGS test also performed well at predicting antimicrobial resistance phenotypes. Patients with a late-onset VAP had a significantly greater proportion of ARGs in their respiratory microbiome compared to those with early-onset VAP (P = 0.041). Moreover, the median turnaround time of mNGS was 4.43 h, while routine culture was 72.00 h.Conclusion: In this study, we developed a workflow that can accurately detect VAP pathogens and enable prediction of antimicrobial resistance phenotypes within 5 h of sample receipt by mNGS.Keywords: mechanical ventilation, endotracheal aspirate, pathogen diagnosis, antibiotic resistance, NGS

Background Epilepsy is a neurological disorder that is usually detected by electroencephalogram (EEG) signals. Since manual examination of epilepsy seizures is a laborious and time-consuming process, lots of automatic epilepsy detection algorithms have been proposed. However, most of the available classification algorithms for epilepsy EEG signals adopted a single feature extraction, in turn to result in low classification accuracy. Although a small account of studies have carried out feature fusion, the computational efficiency is reduced due to too many features, because there are also some poor features that interfere with the classification results. Methods In order to solve the above problems, an automatic recognition method of epilepsy EEG signals based on feature fusion and selection is proposed in this paper. Firstly, the Approximate Entropy (ApEn), Fuzzy Entropy (FuzzyEn), Sample Entropy (SampEn), and Standard Deviation (STD) mixed features of the subband obtained by the Discrete Wavelet Transform (DWT) decomposition of EEG signals are extracted. Secondly, the random forest algorithm is used for feature selection. Finally, the Convolutional Neural Network (CNN) is used to classify epilepsy EEG signals. Results The empirical evaluation of the presented algorithm is performed on the benchmark Bonn EEG datasets and New Delhi datasets. In the interictal and ictal classification tasks of Bonn datasets, the proposed model achieves an accuracy of 99.9%, a sensitivity of 100%, a precision of 99.81%, and a specificity of 99.8%. For the interictal-ictal case of New Delhi datasets, the proposed model achieves a classification accuracy of 100%, a sensitivity of 100%, a specificity of 100%, and a precision of 100%. Conclusion The proposed model can effectively realize the high-precision automatic detection and classification of epilepsy EEG signals. This model can provide high-precision automatic detection capability for clinical epilepsy EEG detection. We hope to provide positive implications for the prediction of seizure EEG.

The invention of axenic media for culturing Coxiella burnetii has greatly promoted studies on this fastidious bacterium. In this study, we report a methylcellulose-supplemented ACCM-2 medium that allows the enumeration of C. burnetii colonies after growing for up to 15 days. Colony forming units (CFUs) of C. burnetii from both axenic and cell cultures were measured in this methylcellulose medium at various time points (8, 12, and 15 days post-plating). Increasing CFU numbers were observed for both cultures at these time points. The ratios of genome equivalents to CFUs at 15 days post-plating and the ratios of CFUs at 15 days to 8 days post-plating were employed to evaluate the viability and vitality of C. burnetii, respectively. We discovered that C. burnetii from cell and axenic cultures exhibit similar viability (7.72 vs 7.11), but that cell culture-derived C. burnetii demonstrates greater vitality than axenic cultures (1.63 vs 5.2). This work sheds light on the normal viability but low vitality of ACCM-2-derived C. burnetii.

The life-threatening disease streptococcal toxic shock-like syndrome (STSLS), caused by the bacterial pathogen Streptococcus suis (S. suis). Proinflammatory markers, bacterial load, granulocyte recruitment, and neutrophil extracellular traps (NETs) levels were monitored in wild-type (WT) and Fpr2-/- mice suffering from STSLS. LXA4 and AnxA1, anti-inflammatory mediators related to Fpr2, were used to identity a potential role of the Fpr2 in STSLS development. We also elucidated the function of Fpr2 at different infection sites by comparing the STSLS model with the S. suis-meningitis model. Compared with the WT mice, Fpr2-/- mice exhibited a reduced inflammatory response and bacterial load, and increased neutrophil recruitment. Pretreatment with AnxA1 or LXA4 impaired leukocyte recruitment and increased both bacterial load and inflammatory reactions in WT but not Fpr2-/- mice experiencing STSLS. These results indicated that Fpr2 impairs neutrophil recruitment during STSLS, and this impairment is enhanced by AnxA1 or LXA4. By comparing the functions of Fpr2 in different S. suis infection models, inflammation and NETs was found to hinder bacterial clearance in S. suis meningitis, and conversely accelerate bacterial clearance in STSLS. Therefore, interference with neutrophil recruitment could potentially be harnessed to develop new treatments for this infectious disease.

Asymmetric microcavities supporting Whispering-gallery modes (WGMs) are of great significance for on-chip optical information processing. We establish asymmetric microcavities on topologically curved surfaces, where the geodesic light trajectories completely reconstruct the cavity mode features. The curvature-mediated photon lifetime engineering enables the enhancement of the quality factors of periodic island modes by up to 200 times. Strong and weak coupling between modes of very different origins occur when the space curvature brings them into resonance, leading to a fine tailoring of the cavity photon energy and lifetime and the observation of non-Hermitian exceptional point (EP). At large space curvatures, the role of the WGMs is replaced by high-Q periodic modes protected by the high stability of island-like light trajectory. Our work demonstrates interesting physical mechanism at the crosspoint of optical chaotic dynamics, non-Hermitian physics and geodesic optical devices, and would initiate the novel area of geodesic microcavity photonics.

Metagenomic next-generation sequencing (mNGS) is a novel useful strategy that is increasingly used for pathogens detection in clinic. Some emerging mNGS technologies with long-read ability are useful to decrease sequencing time and increase diagnosed accuracy, which is of great significance in rapid pathogen diagnosis. Reliable DNA extraction is considered critical for the success of sequencing; hence, there is thus an urgent need of gentle DNA extraction method to get unbiased and more integrate DNA from all kinds of pathogens. In this study, we systematically compared three DNA extraction methods (enzymatic cell lysis based on MetaPolyzyme, mechanical cell lysis based on bead beating, and the control method without pre–cell lysis, respectively) by assessing DNA yield, integrity, and the microbial diversity based on long-read nanopore sequencing of urine samples with microbial infections. Compared with the control method, the enzymatic-based method increased the average length of microbial reads by a median of 2.1-fold [Inter Quartile Range (IQR), 1.7–2.5; maximum, 4.8) in 18 of the 20 samples and the mapped reads proportion of specific species by a median of 11.8-fold (Inter Quartile Range (IQR), 6.9–32.2; maximum, 79.27]. Moreover, it provided fully (20 of 20) consistent diagnosed results to the clinical culture and more representative microbial profiles (P < 0.05), which all strongly proves the excellent performance of enzymatic-based method in long-read mNGS–based pathogen identification and potential diseases diagnosis of microbiome related.

Nowadays, simultaneous inhibition of multiple targets through drug combination is an important anticancer strategy owing to the complex mechanism behind tumorigenesis. Recent studies have demonstrated that the inhibition of histone deacetylases (HDACs) will lead to compensated activation of a notorious cancer-related drug target, signal transducer and activator of transcription 3 (STAT3), in breast cancer through a cascade, which probably limits the anti-proliferation effect of HDAC inhibitors in solid tumors. By incorporating the pharmacophore of the HDAC inhibitor SAHA (vorinostat) into the STAT3 inhibitor pterostilbene, a series of potent pterostilbene hydroxamic acid derivatives with dual-target inhibition activity were synthesized. An excellent hydroxamate derivate, compound 14, inhibited STAT3 (KD = 33 nM) and HDAC (IC50 = 23.15 nM) with robust potency in vitro. Compound 14 also showed potent anti-proliferation ability in vivo and in vitro. Our study provides the first STAT3 and HDAC dual-target inhibitor for further exploration.

Silicon (Si) is generally considered as a poor photon emitter, and various scenarios have been proposed to improve the photon emission efficiency of Si. Here, we report the observation of a burst of the hot electron luminescence from Si nanoparticles with diameters of 150-250 nm, which is triggered by the exponential increase of the carrier density at high temperatures. We show that the stable white light emission above the threshold can be realized by resonantly exciting either the mirror-image-induced magnetic dipole resonance of a Si nanoparticle placed on a thin silver film or the surface lattice resonance of a regular array of Si nanopillars with femtosecond laser pulses of only a few picojoules, where significant enhancements in two- and three-photon-induced absorption can be achieved. Our findings indicate the possibility of realizing all-Si-based nanolasers with manipulated emission wavelength, which can be easily incorporated into future integrated optical circuits.

Polymer passivation layers can improve the open-circuit voltage of perovskite solar cells when inserted at the perovskite-charge transport layer interfaces. Unfortunately, many such layers are poor conductors, leading to a trade-off between passivation quality (voltage) and series resistance (fill factor, FF). Here, we introduce a nanopatterned electron transport layer that overcomes this trade-off by modifying the spatial distribution of the passivation layer to form nanoscale localized charge transport pathways through an otherwise passivated interface, thereby providing both effective passivation and excellent charge extraction. By combining the nanopatterned electron transport layer with a dopant-free hole transport layer, we achieved a certified power conversion efficiency of 21.6% for a 1-square-centimeter cell with FF of 0.839, and demonstrate an encapsulated cell that retains ~91.7% of its initial efficiency after 1000 hours of damp heat exposure.

Many chemotherapeutic drugs and photosensitizers suffer from poor solubility, unspecific delivery and uncontrollable release, which severely impede their biomedical applications. Herein, we designed a type of ROS-cleavable hydrophilic diselenide nanoparticles through self-assembling of PEG-modified camptothecin (CPT, a hydrophobic drug) and meso‑tetra (4-carboxyphenyl) porphine (TCPP, a hydrophobic photosensitizer). The TCPP@SeSe-CPT nanomedicine (particle size: 116.5 ± 1.9 nm) has stability for long-time blood circulation. Near-infrared (NIR) laser-triggered generation of ROS from TCPP can efficiently break the ROS-sensitive diselenide bond, which induces the decomposition of TCPP@SeSe-CPT nanomedicine for concurrent release of CPT and TCPP. Moreover, the released amounts of CPT and TCPP can be regulated by adjusting the NIR laser irradiation time. Such NIR-controlled release of CPT and TCPP can give rise to on-demand synergistic chemo-/photodynamic therapeutic effects for maximized tumor growth suppression with minimized side effects. STATEMENT OF SIGNIFICANCE: In this work, a ROS-cleavable diselenide nanoparticle was designed and successfully self-assembled with the hydrophobic drug camptothecin and photosensitizer TCPP into a hydrophilic TCPP@SeSe-CPT nanomedicine. Compared with traditional drug delivery systems, TCPP@SeSe-CPT nanomicelles could reduce premature drug release and co-deliver hydrophobic chemotherapeutic drugs/photosensitizers to tumors, which yielded a NIR-controlled synergistic chemo-/photodynamic therapeutic effect. Since diselenide bond is more sensitive than the traditional disulfide bond, under the 660 nm laser irradiation (300 mW/cm

Urinary tract infections (UTIs) are among the most common acquired bacterial infections in humans. The current gold standard method for identification of uropathogens in clinical laboratories is cultivation. However, culture-based assays have substantial drawbacks, including long turnaround time and limited culturability of many potential pathogens. Nanopore sequencing technology can overcome these limitations and detect pathogens while also providing reliable predictions of drug susceptibility in clinical samples. Here, we optimized a metagenomic nanopore sequencing (mNPS) test for pathogen detection and identification in urine samples of 76 patients with acute uncomplicated UTIs. We first used twenty of these samples to show that library preparation by the PCR Barcoding Kit (PBK) led to the highest agreement of positive results with gold standard clinical culture tests, and enabled antibiotic resistance detection in downstream analyses. We then compared the detection results of mNPS with those of culture-based diagnostics and found that mNPS sensitivity and specificity of detection were 86.7% [95% confidence interval (CI), 73.5–94.1%] and 96.8% (95% CI, 82.4–99.9%), respectively, indicating that the mNPS method is a valid approach for rapid and specific detection of UTI pathogens. The mNPS results also performed well at predicting antibiotic susceptibility phenotypes. These results demonstrate that our workflow can accurately diagnose UTI-causative pathogens and enable successful prediction of drug-resistant phenotypes within 6 h of sample receipt. Rapid mNPS testing is thus a promising clinical diagnostic tool for infectious diseases, based on clinical urine samples from UTI patients, and shows considerable potential for application in other clinical infections.

Aiming at training the feed-forward threshold neural network consisting of nondifferentiable activation functions, the approach of noise injection forms a stochastic resonance based threshold network that can be optimized by various gradient-based optimizers. The introduction of injected noise extends the noise level into the parameter space of the designed threshold network, but leads to a highly non-convex optimization landscape of the loss function. Thus, the hyperparameter on-line learning procedure with respective to network weights and noise levels becomes of challenge. It is shown that the Adam optimizer, as an adaptive variant of stochastic gradient descent, manifests its superior learning ability in training the stochastic resonance based threshold network effectively. Experimental results demonstrate the significant improvement of performance of the designed threshold network trained by the Adam optimizer for function approximation and image classification.

A rarely reported clinical specimen of Aspergillus spinulosporus was isolated from an immunocompetent 22-month-old boy who was suffering from central nervous system aspergillosis and meningitis. The patient had no comorbidity, organ transplantation, or other surgical operations that lead to invasive aspergillosis. A. spinulosporus is mostly a soil borne strain, and only three invasive aspergillosis cases involving this strain have been reported. We isolated this strain from cerebrospinal fluid, cultured it successfully on PDA medium, and named it BJCH M5. We performed a complete genomic and phenotypic analysis, evolutionary relationship, secondary metabolites analysis, identification of virulence factor, and pairwise synteny analysis. We sequenced the complete 31.6 MB genome of A. spinulosporus, including the eight chromosomes and mitochondria. 11,356 protein-coding genes were predicted. BJCHM 5 has a high sequence identity with ten virulent factors of Aspergillus fumigatus. It also encodes two unique BGCs (Biosynthetic gene clusters) which are involved in human infection. Pairwise synteny analysis demonstrated that this strain has chromosome arrangement differences from A. nidulans. In conclusion, we isolated a specimen of the rarely reported pathogen A. spinulosporus and performed a complete genome assembly and functional characteristic analysis.

Random lasing (RL) from self-constructed localized cavities based on micropits scatters in a single GaN microwire (MW) was investigated. The spectra and spatial resolution of RL exhibits that the lasing modes originated from different regions in the MW. Temperature-dependent lasing measurement of GaN RL shows an excellent characteristic temperature of about 52 K. In addition, the dependence of spatial localized cavities’ dimension on the pumping intensity profile and temperature was studied by fast Fourier transform spectroscopy. For GaN RL, the optical feedback was supported by localized paths through the scattering effect of micropits in the MW. The scattering feedback mechanism for RL can avoid the enormous difficulty in fabricating artificial cavity structures for GaN. Hence, the results in this paper represent a low-cost technique to realize GaN-based ultraviolet laser diodes without the fabrication difficulty of cavity facets.

In this paper, the generalized energy (GE) detector is investigated for detecting weak random signals via vibrational resonance (VR). By artificially injecting the high-frequency sinusoidal interferences into an array of GE statistics formed for the detector, we show that the normalized asymptotic efficacy can be maximized when the interference intensity takes an appropriate non-zero value. It is demonstrated that the normalized asymptotic efficacy of the dead-zone-limiter detector, aided by the VR mechanism, outperforms that of the GE detector without the help of high-frequency interferences. Moreover, the maximum normalized asymptotic efficacy of dead-zone-limiter detectors can approach a quarter of the second-order Fisher information for a wide range of non-Gaussian noise types.

Nonlinear multiphoton absorption technology is crucial for developing novel optoelectronic devices and nanophotonics. The large enhancement of two-photon absorption (TPA) photoresponse by a high Q-factor whispering gallery mode (WGM) resonance based on a single-microwire (MW) self-formed hexagonal cavity was investigated comprehensively in this paper. The typical quadratic relationship of photocurrent as a function of incident power indicated that excited carriers resulted from a third-order nonlinear mechanism. Moreover, the photocurrent response had a dramatic dependence on the spatial location of the focus spot of the incident photons. It was demonstrated that the TPA photocurrent response in the resonant WGM mode was one-order of magnitude larger than the response in the Fabry-Perot mode. Furthermore, the photoresponse characteristics of TPA detection exhibited sensitive dependence on the incident laser polarization direction.

Rock-ice avalanches pose serious risks to humans and infrastructures due to their extremely large volumes and high mobility in glacierized mountain regions. The mobility of rock-ice avalanches is supposed to be influenced by water, while the solid-liquid interactions induced by minor wetting remain an open issue. A series of flume tests was performed to investigate the influence of a small amount of water (no more than 4% of the gravel weight) on the behavior and mobility of gravel-ice mixtures. The test results show that intergranular refreezing bonds were created with a preliminary addition of water. The breakup of some weak refreezing bonds during particle rearrangement likely dissipated some kinetic energy, and thus, the mixture mobility was reduced. As the water content increased, the thermal conductivity could likely not remain efficient enough to refreeze all the trapped water and thus allowed unfrozen water to lubricate particle corners, which enhanced mixture mobility. With a further increase in the water content, suction-induced cohesion cemented particles as clusters and reduced mixture mobility. However, a high ice content resulted in mobility enhancement with increasing water content because more gravel was refrozen into the ice matrix, and thus, the basal friction was lowered by the occupation of ice cubes at the bottom. The redistribution pattern of trapped water during mass propagation changed at a characteristic water content. When the water content was lower than the characteristic content, superficially cohered water detached from the surface asperity of one particle and transferred to another during particle rearrangement, i.e., local redistribution of trapped water. When the water content was higher than the characteristic content, the downward transfer of a considerable amount of trapped water was triggered by particle rearrangement under the influence of gravity, i.e., bulk redistribution of trapped water. The water experiencing bulk redistribution influenced the mixture mobility by exerting intergranular drag force via the build-up and break-up of liquid bridges, while locally redistributed water influenced mixture mobility by altering the surface properties of particles. This study is expected to be helpful in better understanding the propagation mechanisms of water-poor rock-ice avalanches and in improving relevant hazard assessments.

Semiconductor micro/nanowire is an attractive candidate for light-emitting devices (LED), especially laser diodes, due to its ideal geometric shape, excellent optical performance, and electrical transport properties. However, the realization of single micro/nanostructure semiconductor LED or lasers is still a challenge topic. In this Letter, we demonstrated a feasible route to fabricate electrically injection single microwire (MW) light-emitting devices. First, the excellent optical properties of single MW were investigated comprehensively, especially for the self-formed high-Q whisper gallery mode lasing. By properly engineering the band alignment of n-ZnO MW/p-GaN heterojunction using a dielectric MgO interlayer, the effective carrier injection and excitonic-type recombination electroluminescence was realized in the single MW active media. Our results present a significant step toward future fabrication of single micro/nanowire LED and laser diode.

Etoposide is one of the most used first-line chemotherapeutic drugs. However, its application is still limited by its side effects. Herein, we designed a novel H2O2 sensitive prodrug 6YT for selectively releasing the anti-cancer drug etoposide in cancer cells. In this paper, etoposide and a hydrogen peroxide (H2O2) sensitive aryl borate ester group were linked by a fluorescent coumarin and finally the prodrug 6YT was generated. The fluorescence of coumarin was quenched before the connected aryl borate ester group was cleaved by H2O2. However, in the high level H2O2 environment of the tumor, the fluorescence could be activated simultaneously with the release of etoposide, and the drug release state of the prodrug was monitored real-time. With the support of 6YT, we obtained direct and visual evidence of etoposide release in a high H2O2 environment both in cells and zebrafish. The prodrug 6YT was also verified with comparable activity and improved safety with etoposide both in cells and in a mouse model. As a safe and effective prodrug, 6YT is expected to be one of the promising candidates in chemotherapy against cancer.

We report that the output signal-to-noise ratio (SNR) of a parallel array of hard limiters can be maximized at an optimal high-frequency vibration amplitude, i.e. the vibrational resonance (VR) effect. As the external noise shape parameter varies, the bifurcation mode of maximal SNR gain is found, and the upper limit of SNR gain is discussed. We theoretically demonstrate a tractable realization of an infinite array approached by a finite array of two hard limiters, and design an electronic circuit experiment to verify the feasibility of this effective method. These results indicate the potential applications of vibrational devices to array signal processing.

Deregulation of GP130 in signal transduction is involved in multiple types of human diseases, especially in cancers, indicating that GP130 is an attractive target for cancer therapy. However, GP130 was conventionally considered as an undruggable target thus the discovery of GP130 PPI inhibitors is extremely challenging. By the aid of structure-based drug design, in this study, two series of bazedoxifene based analogues were designed to target GP130 D1 domain and block the IL-6/GP130/STAT3 signaling pathway for antitumor treatment. Most of these designed compounds displayed potent anti-proliferative activity against cancer cells. The representative compound 10a was demonstrated to directly bind to GP130 protein with an affinity (KD) value of 3.8 μM via both SPR and DARTS methods. Subsequently, molecular docking study predicted that 10a targeted D1 domain of GP130 and co-IP assay demonstrated that 10a did not inhibit IL-6R/GP130 interaction, which meant 10a did not bind to the D2 and D3 domains of GP130. Moreover, 10a selectively inhibited JAK2 and STAT3 phosphorylation as well as IL-6 induced STAT3 phosphorylation. 10a effectively inhibited tumor cell viability, migration and promoted apoptosis. Furthermore, 10a effectively suppressed xenograft model tumor growth in vivo. Taken together, this study described a new class of bazedoxifene derived GP130 inhibitors as antitumor agents.

Compared with conventional lasers, the random laser is realized through strong multiple scatterings in disordered gain system. In this paper, random lasing (RL) in one-dimensional metal surface plasmon (SP) waveguide with gold-plated self-formed silicon pyramids was investigated comprehensively. Consequently, the emission intensity of RL was enhanced dramatically and the RL threshold was reduced significantly through Au-coated Si spiky tips. Meanwhile, one-dimensional metal SP channel waveguides confined the emitting light in a certain direction with a small divergence angle. Using FDTD simulations, it was found that the enhancement effect for RL is likely attributed to the localized surface plasmon (LSP) field. In addition, the LSP field nearby the spiky tips can enhance field-molecule interaction, which was benefit for lasing in small scale. The results in this letter supplied a feasible method to realize the application of RL in subwavelength optical elements.

This paper investigates noise benefits to the statistics with sign function in robust estimation problems. Sign function, as the score function of a robust M-estimator in location estimation, composes a median estimator. We show that, the mean-square error (MSE) of this statistic can be effectively decreased both under the background of the symmetric and asymmetric contamination noise by adding additive noise. Furthermore, the noise-enhanced effect observed in the linear regression estimation demonstrates that the conclusions in the location parameter estimation can be extended to multidimensional parameter estimation tasks.

The realization of one-dimension random laser by using artificially fabricated scatterers in our experiment represents a novelty method towards the development of manipulated-RL, which will highlight the application of disordered system on optoelectronic devices.

Identifying strong third-order nonlinearities and low nonlinear optical losses, including photonic crystals and plasmonic structure1–4, are crucial for developing optoelectronic devices and nanophotonics technologies. We presented large enhancement of degenerate two-photon absorption through hexagonal cavity resonance in single-crystalline ZnO microwire involved Fabry-Perot (FP) cavity and whispering gallery mode (WGM) cavity. We reported it is feasible to fabricate degenerate two-photon absorption single microwire photodetector. The device photocurrent performed a typical parabola curve with the increasing of incident irradiance due to third-order nonlinearity. We experimentally demonstrated two-photon absorption enhancement resonated in WGM cavity is more excellent than that in FP cavity for the highly confined optical fields ability at room temperature.

Single microbelt (MB] photodetectors with metal-semiconductor-metal (MSM] structure have been demonstrated and characterized comprehensively. For single-photon absorption, the maximum responsivity of ZnO-MB photodetector can reach as high as 1.4×105 A/W at 20 V bias. The results about photoresponse of MB-detector reveals that two relaxation mechanisms contribute to the carrier decay time. Moreover, the two-photon absorption upconversion photoresponsivity in the single-MB detector has also been realized, which is first report about the two-photon absorption detector to the best of our knowledge. The excellent two-photon absorption photoresponsivity characteristic of MB device can be available not only for detector but also for solar cell and biomedical imaging. Above results present a significant step towards future fabrication of single micro/nano-structure based multiphoton excitation optoelectronic device.

Indium cluster in InGaN epilayers prepared with different H 2 -treating times was investigated. In cluster with the form of lower atom bonds was evidenced by Raman spectra. Carrier lifetime was found to increase with the H 2 -treating time.

International audience; In this paper, we investigate the first exploitation of the vibrational resonance (VR) effect to detect weak signals in the presence of strong background noise. By injecting a series of sinusoidal interference signals of the same amplitude but with different frequencies into a generalized correlation detector, we show that the detection probability can be maximized at an appropriate interference amplitude. Based on a dual-Dirac probability density model, we compare the VR method with the stochastic resonance approach via adding dichotomous noise. The compared results indicate that the VR method can achieve a higher detection probability for a wider variety of noise distributions.

Rock-ice avalanches in cold high-mountain regions have extremely high mobility and enormous destructive potential. As a special material component, ice is supposed to play a crucial role in enhancing the mobility of rock-ice avalanches. A series of small flume tests was performed to quantify the influence of the ice content, initial arrangement, and released mass on the behavior and mobility of gravel-ice mixtures, and to provide insights into the propagation mechanisms of rock-ice avalanches in their initial phase. Test results show that the run-out distance and abrupt-stopping distance increased significantly when the ice content reached 30%. This implies that a certain amount of ice was helpful in enhancing the mobility of rock-ice avalanches. With an ice content higher than 80%, the run-out distances decreased slightly. The run-out distance in the well-mixed case was greater than that in the layered-arrangement cases. Segregation, the phenomenon of ice cubes to tend toward the surface and front of the deposit, was vital for the mobility of gravel-ice mixtures. Segmentation was much more evident with an increase in ice content, which indicates that the deposit was highly dispersed and spreading. This was a key difference in the deposition morphology between cases of gravel-ice mixture and cases of pure gravel or pure ice. Although little meltwater was generated in this study, the development of intergranular water film and suction-induced cohesion caused the particles to pack more closely together and to act as clusters rather than individual particles. This study provides insights into the propagation mechanisms and deposition characteristics of rock-ice avalanches.

Single microbelt (MB) photodetectors with metal–semiconductor-metal structure have been demonstrated and characterized comprehensively. For single-photon absorption, the maximum responsivity of ZnO-MB photodetector can reach as high as 1.4 × 105 A W−1 at 20 V bias. The results about photoresponse of MB-detector reveals that two relaxation mechanisms contribute to the carrier decay time. Moreover, the two-photon absorption upconversion photoresponsivity in the single-MB detector has also been realized, which is the first report about the two-photon absorption detector to the best of our knowledge. The excellent two-photon absorption photoresponsivity characteristic of the MB device can be available not only for detector but also for solar cell and biomedical imaging. The above results present a significant step towards future fabrication of single micro/nano-structure based multiphoton excitation optoelectronic devices.

An endophyte, designated “AV 17-3”, was isolated from a stem sample of an Australian Prickly Tea Tree, Leptospermum junipae, growing in the coastal area of the state of Victoria, Australia. Isolation of the partial 18S rDNA sequence and a subsequent search in GenBank revealed high homology to the fungal genus Quambalaria. Standard scanning electron microscopy (SEM) as well as environmental SEM of the isolate revealed that it produces widely elliptically shaped spores (4.5–5.5 × 1–2.2 μm) and secondary budding spores (2.0–3.0 × 1.5–1.7μm) on conidiophores, all showing a close similarity to Quambularia pitereka. The fungus produces bioactive compounds that were inhibitory to all and lethal to some pathogenic fungi, such as Phytophthora erythroseptica. It also inhibited or killed other tested bacteria and fungi, including Candida albicans, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Pseudomonas aeruginosa, Xanthomonas citri, Mycosphaerella fijiensis, Saccharomyces cerevisae and Bacillus ...

Geobacillus, a bacterial genus, is represented by over 25 species of Gram-positive isolates from various man-made and natural thermophilic areas around the world. An isolate of this genus (M-7) has been acquired from a thermal area near Yellowstone National Park, MT and partially characterized. The cells of this organism are globose (ca. 0.5 mu diameter), and they are covered in a matrix capsule which gives rise to elongate multicelled bacilliform structures (ranging from 3 to 12 mum) as seen by light and atomic force microscopy, respectively. The organism produces unique petal-shaped colonies (undulating margins) on nutrient agar, and it has an optimum pH of 7.0 and an optimum temperature range of 55-65 degrees C. The partial 16S rRNA sequence of this organism has 97% similarity with Geobacillus stearothermophilus, one of its closest relatives genetically. However, uniquely among all members of this genus, Geobacillus sp. (M-7) produces volatile organic substances (VOCs) that possess potent antibiotic activities. Some of the more notable components of the VOCs are benzaldehyde, acetic acid, butanal, 3-methyl-butanoic acid, 2-methyl-butanoic acid, propanoic acid, 2-methyl-, and benzeneacetaldehyde. An exposure of test organisms such as Aspergillus fumigatus, Botrytis cinerea, Verticillium dahliae, and Geotrichum candidum produced total inhibition of growth on a 48-h exposure to Geobacillus sp.(M-7) cells (ca.10(7)) and killing at a 72-h exposure at higher bacterial cell concentrations. A synthetic mixture of those available volatile compounds, at the ratios occurring in Geobacillus sp. (M-7), mimicked the bioactivity of this organism.

Colletotrichum dematium is an endophytic fungus recovered from a Pteromischum sp. growing in a tropical forest in Costa Rica. This fungus makes a novel peptide antimycotic, colutellin A, with a MIC of 3.6 microg ml(-1) (48 h) against Botrytis cinerea and Sclerotinia sclerotiorum. Collutellin A has a mass of 1127.7 Da and contains residues of Ile, Val, Ser, N-methyl-Val and beta-aminoisobutryic acid in nominal molar ratios of 3 : 2 : 1 : 1 : 1, respectively. Independent lines of evidence suggest that the peptide is cyclic and sequences of Val-Ile-Ser-Ile and Ile-Pro-Val have been deduced by MS/MS as well as Edman degradation methods. Colutellin A inhibited CD4(+) T-cell activation of interleukin 2 (IL-2) production with an IC(50) of 167.3+/-0.38 nM, whereas cyclosporin A in the same test yielded a value of 61.8 nM. Inhibition of IL-2 production by collutellin A at such a low concentration indicates the potential immunosuppressive activity of this compound. In repeated experiments, cyclosporin A at or above 8 microg ml(-1) exhibited high levels of cytotoxicity on human peripheral blood mononuclear cells, whereas collutellin A or DMSO (carrier) alone, after 24 and 48 h of culture, exhibited no toxicity. Because of these properties collutellin A has potential as a novel immunosuppressive drug.

We investigate the noise-enhanced information transmission with generalized Gaussian signal via the measure of mutual information, in context of suprathreshold stochastic resonance (SSR). The effects of the noise intensity and the exponent parameter of the input signal on mutual information are discussed. It is shown that the qualitative behavior of SSR does not depend on the actual signal and noise distribution. However, it is found that the exponent parameter of the generalized Gaussian signal distribution has a crucial effect on the position or the maximum value of the mutual information.

This paper studies the stochastic resonance effect in a hierarchical integrate-and-fire (IF) neural networks characterized by the measure of average mutual information. It is shown that, as the internal noise intensity increases, the average mutual information can be optimized at an optimal non-zero noise level. It is also noted that the maximum of mutual information obtained in the resonant region can be further enhanced for a suitable signal frequency. This leads to the more efficient transduction of signals in the IF neural network. Correspondingly, the interval time of spikes, regularly established at the optimal noise level, is in accord with the input signal period. The present results are meaningful to the study of signal transduction through hierarchical IF neural networks.

An endophytic fungus, Gliocladium roseum (NRRL 50072), produced a series of volatile hydrocarbons and hydrocarbon derivatives on an oatmeal-based agar under microaerophilic conditions as analysed by solid-phase micro-extraction (SPME)-GC/MS. As an example, this organism produced an extensive series of the acetic acid esters of straight-chained alkanes including those of pentyl, hexyl, heptyl, octyl, sec-octyl and decyl alcohols. Other hydrocarbons were also produced by this organism, including undecane, 2,6-dimethyl; decane, 3,3,5-trimethyl; cyclohexene, 4-methyl; decane, 3,3,6-trimethyl; and undecane, 4,4-dimethyl. Volatile hydrocarbons were also produced on a cellulose-based medium, including heptane, octane, benzene, and some branched hydrocarbons. An extract of the host plant, Eucryphia cordifolia (ulmo), supported the growth and hydrocarbon production of this fungus. Quantification of volatile organic compounds, as measured by proton transfer mass spectrometry (PTR-MS), indicated a level of organic substances in the order of 80 p.p.m.v. (parts per million by volume) in the air space above the oatmeal agar medium in an 18 day old culture. Scaling the PTR-MS profile the acetic acid heptyl ester was quantified (at 500 p.p.b.v.) and subsequently the amount of each compound in the GC/MS profile could be estimated; all yielded a total value of about 4.0 p.p.m.v. The hydrocarbon profile of G. roseum contains a number of compounds normally associated with diesel fuel and so the volatiles of this fungus have been dubbed ‘myco-diesel’. Extraction of liquid cultures of the fungus revealed the presence of numerous fatty acids and other lipids. All of these findings have implications in energy production and utilization.

The endophytic fungus Chloridium sp. produces javanicin under liquid and solid media culture conditions. This highly functionalized naphthaquinone exhibits strong antibacterial activity against Pseudomonas spp., representing pathogens to both humans and plants. The compound was crystallized and the structure was elucidated by X-ray crystallography. The X-ray structure confirms the previously elucidated structure of the compound that was done under standard spectroscopic methods. The importance of javanicin in establishing symbiosis between Chloridium sp. and its host plant, Azadirachta indica, is briefly discussed.