Distribution characteristics of microorganisms in sediments of Dagu River and their biological indicator function for evaluating eco-environmental quality of rural river.

The microorganisms in sediments play a crucial role in biogeochemical cycle processes, and numerous studies have shown that microbial community is closely related to environmental factors. However, the usability of sediment microorganisms to evaluate the eco-environment quality of rural rivers has not been adequately explored. This study investigated the distribution characteristics and response of sediment microorganisms to environmental parameters and benthic organisms. Based on the environmental parameters and benthic community indices, the 12 stations were divided into high-polluted group A, moderate-polluted group B and low-polluted group C. Station DG01 and DG02 in group A had the highest level of As and Ni pollution and nutrient concentration, and DG09 in group A had the lowest benthic diversity. Correspondingly, group A had the lowest abundance of Proteobacteria, which has a higher requirement for the environment than Planctomycetes. Group B had the highest sulfide level (97.45 mg/kg), and bacteria (Thiobacillus, Sulfurisoma and Sulfuritalea) with genes involved in sulfur cycling were more enriched in this group. Group C had the lowest level of total nitrogen (243.36 mg/kg), and Rhodanobacteraceae in Xanthomonadales might be a key bioindicator for low nitrogen. In addition, Chlorophyta was found to be more susceptible to heavy metals, and moreover co-occurrence networks showed that microeukaryotes were more sensitive to heavy metal pollution compared to benthic animals and prokaryotes. Therefore, this study suggested that benthic microorganisms especially microeukaryotes could be used as good indicators for evaluating the eco-environmental quality of rural rivers.

Interaction between the mid-infrared continuous wave laser with a center wavelength of 3.8†µm and fused silica.

The absorption coefficient of fused silica for a mid-infrared (IR) laser is higher than that for a near-IR laser, but smaller than that for a far-IR laser. Therefore, the energy coupling efficiency of the mid-IR laser is higher than that for the near-IR laser, while the penetration depth is higher than that for the far-IR laser. Thus, the mid-IR laser is highly efficient in mitigating damage growth. In this study, a deuterium fluoride (DF) laser with a center wavelength of 3.8 µm was used to interact with fused silica. The temperature variation, changes in the reflected and transmitted intensities of the probe light incident on the laser irradiation area, and the vaporization and melting sputtering process were analyzed. The results demonstrate that when the laser intensity was low (<1.2 kW/cm2), no significant melting was observed, and the reflection and transmission properties gradually recovered after the end of the laser irradiation process. With a further increase in the laser intensity, the sample gradually melted and vaporized. At a laser intensity above 5.1 kW/cm2, the temperature of the sample increased rapidly and vapors in huge quantity evaporated from the surface of the sample. Moreover, when the laser intensity was increased to 9.5 kW/cm2, the sample melted and an intense melting sputtering process was observed, and the sample was melted through.

Dynamic moist air monitor in a micro area with extremely high figure-of-merit.

In the rapidly changing moisture air, conventional relative humidity (RH) sensors are often difficult to respond in time and accurately due to the limitation of flow rate and non-uniform airflow distribution. In this study, we numerically demonstrate that humidity changes on micro-zones can be monitored in real time using a Bloch surface wave (BSW) ubiquitous in one-dimensional photonic crystals (1DPC). This phenomenon can be observed by leakage radiation microscope (LRM). After theoretically deriving the angular resolution limit of LRM, we obtained the minimum BSW angular change on a practical scheme that can be observed in the momentum space to complete the detection, and realized the dynamic real-time monitoring of small-scale humidity change in experiment for the first time. This monitoring method has extremely high figure of merit (FOM) without hysteresis, which can be used in humidity sensing and refractive index sensing as well as the research on turbulence.

Laser ultrasonic loading and optical interference detection of closed cracks in K9 glass.

The traditional optical detection method has a limitation in detecting closed cracks in optical elements. In this Letter, a novel, to the best of our knowledge, method has been developed for the detection of closed cracks in transparent samples. Firstly, behaviors of closed cracks under ultrasonic waves loading are demonstrated through the finite-element method (FEM). Simulation results show that the crack can be opened by the laser ultrasonic shear wave (S-wave). Then, a Mach-Zehnder interferometer system is experimentally established to detect closed cracks under ultrasonic waves loading in the sample. It is demonstrated that closed cracks which cannot be detected by interferometry become visible in interferogram images under ultrasonic waves loading. The width of the opened crack can also be quantitatively estimated. Thus the method would be a promising approach to detect initially closed cracks in optical elements.

Hypoxia-inducible factor-1α inhibition augments efficacy of programmed cell death 1 antibody in murine prostatic cancer models.

This study was designed to explore whether hypoxia-inducible factor-1α (HIF-1α) inhibitor could enhance immunotherapy efficacy in prostate cancer. Western blot was used to detect the expression of HIF-1α in the tumor and peritumor tissues from prostate cancer patients. The analysis from Cancer Genome Atlas database was used to show an association between HIF-1α expression and survival rate in prostate cancer patients. Murine prostate cell-derived xenograft (CDX) model was set up in both nude mice and BALB/c mice to observe the therapeutic effect of HIF-1α inhibitor IDF-11774. Protein expression of HIF-1α, as well as changes in the immune microenvironment, was detected. Moreover, the synergistic antitumor effect of IDF-11774 and PD-1 antibody was detected in another murine prostate cancer model. HIF-1α was found to have higher expression in prostate cancer tumor tissue than in peritumor tissue, and the expression level was negatively correlated with survival rate (P = 0.0157). HIF-1α inhibitor IDF-11774 reduced tumor volume and exhibited better efficacy in BALB/c mouse model (P < 0.0001) with normal immune system, with the same suppression level against HIF-1α. HIF-1α inhibitor reduced CD45+CD11b+Gr-1+ myeloid-derived suppressor cells (P = 0.0027) and CD45+ CD11b+F4/80+CD206hi M2 macrophages (P = 0.0059) but increased the abundance of CD45+CD3+CD8+ T cells (P = 0.0002) and CD45+CD3+CD4+ T cells (P = 0.0001) in tumor-infiltrating immune cells. The same synergistic effect was observed in RM-1 murine prostate CDX tumor model. HIF-1α inhibition augmented the antitumor efficacy of immune checkpoint inhibitor PD-1 antibody in murine prostate cancer models, probably through modulating the immunosuppressive microenvironment.

Synthesis, crystal structure, herbicidal activity and mode of action of new cyclopropane-1,1-dicarboxylic acid analogues.

A new series of cyclopropane-1,1-dicarboxylic (CPD) acid analogues were designed and synthesized. CPD is an inhibitor of ketol-acid reductoisomerase (KARI), an enzyme of the branched chain amino acid pathway in plants. The structures of CPD analogues were characterized by 1H NMR and HRMS. The structure of N,N'-bis(4-(tert-butyl)phenyl)cyclopropane-1,1-dicarboxamide was further elucidated by X-ray diffraction. The herbicidal activities of these compounds were tested against lettuce (Lactuca sativa) and bentgrass (Agrostis stolonifera). Most of these compounds exhibited low herbicidal activity against both plant species. Among them, N,N'-bis(2-ethylphenyl)cyclopropane-1,1-dicarboxamide displayed moderate activity against bentgrass. Inhibition of KARI activity by the CPD analogues was also assessed experimentally and by molecular docking simulation with results supporting inhibition of KARI as their mode of action. These results provide the basis for design of more effective KARI inhibitors.

Selective generation of Lamb modes by a moving continuous-wave laser.

This Letter focuses on the selectively non-contact generation of Lamb wave modes in plates by using a continuous-wave (CW) laser moving along sample surface. Compared with the generated Lamb waves with broadband, multiple modes (the existence of at least two modes at any given frequency) excited by a pulsed laser, the desired single narrowband mode of the Lamb wave can be generated by a moving CW laser, as long as the scanning speed matches the phase velocity of the mode. Moreover, the dispersion curves of the Lamb wave can be obtained directly from the power spectrum of the time-domain signal recorded at each laser's moving speed. Single A0 mode excitation, coupled resonance phenomenon of A0 mode and S0 mode, single S0 mode excitation, and high-order modes appeared successively as scanning speed increased. Especially, the excitation of the pure single S0 mode can be realized, which is suitable for propagation in the case of liquid loading. It is proposed, for the first time to the best of our knowledge, to realize the selection of a single Lamb wave mode by using the CW laser scanning method, which provides a brand-new way for laser ultrasonic excitation.

Nondestructive evaluation of demineralized enamel in a human incisor and molar using laser ultrasonics.

This study aims to evaluate early caries in human teeth with different geometry structures by using the dispersion curves of a surface acoustic wave (SAW) generated by a pulsed laser. Through the finite element method, SAWs propagating on teeth models with different enamel thickness and curvature radius were simulated, and the influence of the geometry difference on the dispersion curves of SAWs was discussed. Laser ultrasonic experiments were performed on an extracted human incisor and molar with different demineralization conditions. The received dispersive surface wave signals were processed via the spectral analysis method to obtain the dispersion curves, and the difference of the dispersion spectra between the incisor and the molar was analyzed and discussed. The result demonstrates that the laser generating the SAW has the ability to evaluate the elastic properties of early caries with different geometry nondestructively.

Design of wedge structure with non-dispersive wedge wave propagation.

This paper focuses on designing a structure using a laser ultrasound technique, wherein wedge waves can propagate without dispersion. First, the impact of curvature radius and truncations on the wedge waves are investigated using finite element method, and the dispersion curves are obtained using a two-dimensional Fourier transformation method. Subsequently, the propagation of non-dispersive wedge waves is realized via a special wedge shape, which was designed with a unique relationship between the curvature radius and truncation, and its correctness is validated using numerical simulation. Finally, experiments are performed to detect the wedge waves, wherein a pulsed laser is coupled with optical fiber excitation, and the waves are detected using an optical vibrometer.

Scanning high-power continuous wave laser-generated bulk acoustic waves.

The ultrasonic bulk waves generated by a high-power continuous laser scanning along the surface of aluminum material were theoretically investigated. Although the temperature rise generated by this scanning laser irradiation was small, it provided a large temperature gradient, which was able to generate measurable ultrasonic waves. Detailed discussions were given to the influence of scanning speed on the generation propagation direction and the amplitude of the wavefront. The longitudinal and transverse waves would be generated in the material only when the scanning speeds reached a certain range. What's more, the amplitude of the wavefronts were significantly enhanced if the wavefront angle controlled by the scanning speed matched with the propagation direction of the ultrasound. In summary, it expounded a method to obtain the ultrasonic signal of direction, controlled from the perspective of numerical simulation, as long as the scanning speed met the requirements.

Interaction between a bubble and a metal target for underwater laser propulsion.

Optical beam deflection and high-speed photographic methods are employed to investigate the interaction mechanism between a laser-induced bubble and a metal target for underwater laser propulsion. A preliminary theory is proposed to reveal the step increases of the kinetic energy transferred to the target during the process of increasing the incident laser energy. This theory also helps to explain the increasing coupling efficiency with incident laser energy for underwater laser propulsion.

Millisecond laser machining of transparent materials assisted by a nanosecond laser with different delays.

A millisecond laser combined with a nanosecond laser was applied to machining transparent materials. The influences of delay between the two laser pulses on processing efficiencies and modified sizes were studied. In addition, a laser-supported combustion wave (LSCW) was captured during laser irradiation. An optimal delay corresponding to the highest processing efficiency was found for cone-shaped cavities. The modified size as well as the lifetime and intensity of the LSCW increased with the delay decreasing. Thermal cooperation effects of defects, overlapping effects of small modified sites, and thermal radiation from LSCW result in all the phenomena.

Synthesis, nematocidal activity and docking study of novel chiral 1-(3-chloropyridin-2-yl)-3-(trifluoromethyl)-1H-pyrazole-4-carboxamide derivatives.

A series of novel chiral fluorinated pyrazole carboxamides derivatives were designed and synthesized. All these title compounds were confirmed by NMR and MS. The primarily nematocidal activity results indicated that some of them exhibited good control efficacy against the tomato root-knot nematode disease caused by Meloidogyne incognita. The docking results indicated that compound 5n interact with amino acid residue Tyr 121, Trp 279 of AchE via hydrogen bond.

The comparison of perioperative outcomes of robot-assisted and open partial nephrectomy: a systematic review and meta-analysis.

BACKGROUND: Robot-assisted partial nephrectomy (RAPN) has been widely used worldwide, to determine whether RAPN is a safe and effective alternative to open partial nephrectomy (OPN) via the comparison of RANP and OPN. METHODS: A comprehensive literature search was performed within the databases including PubMed, Cochrane Library, and Embase updated on 30 September 2015. Summary data with their corresponding 95 % confidence intervals (CIs) were calculated using a random effects or fixed effects model. Heterogeneity and publication bias were also evaluated. RESULTS: A total of 16 comparative studies including 3024 cases were used for this meta-analysis. There are no significant differences in the demographic characteristic between the two groups, but the age was lower and the tumor size was smaller for the RAPN group. RAPN had a longer operative time and warm ischemia time but which showed less estimated blood loss, hospital stay, and perioperative complications. No differences existed in the margin status, the change of glomerular filtration rate, transfusion rate, and conversion rate between the two groups. There was no significant publication bias. CONCLUSIONS: RAPN offered a lower rate of perioperative complications, less estimated blood loss, and shorter length of hospital stay than OPN, suggesting that RAPN can be an effective alternative to OPN. Well-designed prospective randomized controlled trials will be helpful in validating our findings.

Expression of long noncoding RNA lncRNA-n336928 is correlated with tumor stage and grade and overall survival in bladder cancer.

Long noncoding RNAs (lncRNAs) have been implicated playing important roles in human urologic cancers. In the present study, microarray analysis was initially performed to screen the differentially expressed lncRNAs between bladder cancer tissues and paired adjacent non-cancerous tissues (n = 3). Subsequent qRT-PCR validation was conducted using tissue samples from 95 patients with bladder cancer. Results showed that the expression level of lncRNA-n336928 (noncode database ID: n336928) was significantly higher in bladder cancer tissues compared to that in adjacent noncancerous tissues (P < 0.001). Chi-square test showed that expression of lncRNA-n336928 was positively correlated with bladder tumor stage and histological grade (P < 0.001). Kaplan-Meier survival analysis revealed that patients with bladder cancer with high expression of lncRNA-n336928 had shorter overall survival time compared to the patients with low expression of lncRNA-n336928. Multivariate analysis indicated that lncRNA-n336928 was an independent prognostic factor for overall survival for bladder cancer patients. Collectively, our study shows that high expression of lncRNA-n336928 is associated with the progression of bladder cancer, and that lncRNA-n336928 might serve as a biomarker for prognosis of bladder cancer.

Millisecond laser machining of transparent materials assisted by nanosecond laser.

A new form of double pulse composed of a nanosecond laser and a millisecond laser is proposed for laser machining transparent materials. To evaluate its advantages and disadvantages, experimental investigations are carried out and the corresponding results are compared with those of single millisecond laser. The mechanism is discussed from two aspects: material defects and effects of modifications induced by nanosecond laser on thermal stress field during millisecond laser irradiation. It is shown that the modifications of the sample generated by nanosecond laser improves the processing efficiency of subsequent millisecond laser, while limits the eventual size of modified region.

Study of the impact of truncations on wedge waves by using the laser ultrasound technique.

This research focuses on measuring the impact of truncations on the dispersion characteristics of wedge waves propagating along the wedge tip by using the laser-generated ultrasound. First, the finite element method was used to simulate laser-induced wedge waves and the dispersion curves were obtained by using the 2D Fourier transformation method. Pulsed laser excitation and laser-based wedge wave detection were also utilized to investigate these characteristics experimentally. For the 20° and 60° line wedges, both experimental and numerical results indicated that a nonideal wedge tip had great impact on the wedge waves. The modes of the 20° line wedge with truncations presented anomalous dispersion, low mode closed to high mode in high frequency, and the characteristics of antisymmetric Lamb waves as truncation increased. Meanwhile, the modes of the 60° line wedge with truncations showed the characteristics of antisymmetric Lamb waves, and the A1 mode was also observed clearly. The findings of this study can be used to evaluate and detect wedge structure.

Quantitatively assessing flow velocity by the slope of the inverse square of the contrast values versus camera exposure time.

The slope of the inverse square of the contrast values versus camera exposure time at multi-exposure speckle imaging (MESI) can be a new indicator of flow velocity. The slope is linear as the diffuse coefficient in Brownian motion diffusion model and the mean velocity in ballistic motion model. Combining diffuse speckle contrast analysis (DSCA) and MESI, we demonstrate theoretically and experimentally that the flow velocity can be obtained from this slope. The calculation results processes of the slop don't need tedious Newtonian iterative method and are computationally inexpensive. The new indicator can play an important role in quantitatively assessing tissue blood flow velocity.

Study of underwater laser propulsion using different target materials.

In order to investigate the influence of target materials, including aluminum (Al), titanium (Ti) and copper (Cu), on underwater laser propulsion, the analytical formula of the target momentum IT is deduced from the enhanced coupling theory of laser propulsion in atmosphere with transparent overlay metal target. The high-speed photography method and numerical simulation are employed to verify the IT model. It is shown that the enhanced coupling theory, which was developed originally for laser propulsion in atmosphere, is also applicable to underwater laser propulsion with metal targets.

Scanning laser-line source technique for nondestructive evaluation of cracks in human teeth.

This paper describes the first application of a remote nondestructive laser ultrasonic (LU) system for clinical diagnosis of cracks in human teeth, to our knowledge. It performs non-contact cracks detection on small-dimension teeth samples. Two extracted teeth with different types of cracks (cracked tooth and craze lines), which have different crack depths, are used as experimental samples. A series of ultrasonic waves were generated by a scanning laser-line source technique and detected with a laser-Doppler vibrometer on the two samples. The B-scan images and peak-to-peak amplitude variation curves of surface acoustic waves were obtained for evaluating the cracks' position and depth. The simulation results calculated by finite element method were combined with the experimental results for accurately measuring the depth of crack. The results demonstrate that this LU system has been successfully applied on crack evaluation of human teeth. And as a remote, nondestructive technique, it has great potential for early in vivo diagnosis of cracked tooth and even the future clinical dental tests.