Sensitivity of Commercial Enzyme Inhibition Colorimetric Pesticide Residue Rapid Test Kit to a Variety of Pesticides

[Objectives]To fully understand the quality of commercial enzyme inhibition-colorimetric pesticide residue rapid detection kits,so that they can play a greater role in the detection and supervision of agricultural products.[Methods]The sensitivity of 28 kinds of pesticides was determined by using the commercially available enzyme inhibition colorimetric rapid detection kit with Hendu brand.[Results]There was a significant difference in the sensitivity of the kit to each pesticide,and the kit was more sensitive to dichlorvos among the 28 pesticides tested.The sensitivity to methyl isosalifos,dimethoate,isocarbophos,fenthion and phorate was poor,and the sensitivity to quinalphos was different between 3.0 and 2.5 mL.[Conclusions]The large difference of the sensitivity of the enzyme inhibition-colorimetric rapid detection kit for pesticide residues to different kits is a reason for the false positive and false negative test results of the kit,which needs to be considered by relevant personnel.

Earthquake detection in the Jiangsu region, China using graphics-processing-unit-based Match & Locate and rapid earthquake association and location

Earthquake detection and location are essential in earthquake studies,which generally consists of two main classes:waveform-based and pick-based methods.To evaluate the ability of two different methods,a graphicsprocessing-unit-based Match&Locate(GPU-M&L)method and a rapid earthquake association and location(REAL)method are applied to continuous seismic data recorded by 24 digital seismic stations from Jiangsu Seismic Network during 2013 for comparison.GPU-M&L is one of waveform-based methods by waveform cross-correlations while REAL is one of pick-based method to associate arrivals of different seismic phases and locate events through counting the number of P and S picks and travel time residuals.Twenty-six templates are selected from the Jiangsu Seismic Network local catalog by using the GPU-M&L.The number of newly detected and located events is about 2.8 times more than those listed in the local catalog.We both utilize a deep-neural-network-based arrival-time picking method called PhaseNet and a shortterm/long-term average(STA/LTA)trigger algorithm for seismic phase detection and picking by applying the REAL.We then refine seismic locations using a least-squares location method(VELEST)and a high-precision relative location method(hypoDD).By applying STA/LTA and PhaseNet,1006 and 1893 events are associated and located,respectively.The newly detected events are mainly clustered and show steeply dipping fault planes.By analyzing the performance of these methods based on long-term continuous seismic data,the detected catalogs by the GPU-M&L and REAL show that the magnitudes of completeness are 1.4 and 0.8,respectively,which are smaller than 2.6 given by the local catalog.Although REAL provides improvement compared with GPU-M&L,REAL is highly dependent on phase detection and picking which is strongly affected by signal-noise ratio(SNR).Stations at southeast of the study region with low SNR may lead to few detections in the same area.

Near-surface structure from ambient-noise tomography and horizontal-to-vertical spectral ratio beneath the Nankou-Sunhe fault

Active faults pose a great threat to urban security.As the largest NW-trend active fault in Beijing area,the Nankou-Sunhe fault plays an important role in earthquake disaster and city construction.In this study,we collect continuous ambient noise data recorded by 43 temporary short-period seismograph between September 21th to October 12th 2019 to investigate the near-surface structure beneath the Nankou-Sunhe fault by using ambient noise tomography(ANT)and horizontal-to-vertical spectral ratio(HVSR)method.From ambient noise processing,fundamental-mode Rayleigh wave signals are clearly observed in the frequency band of 0.4-2.5 Hz.Then direct surface-wave inversion algorithm is applied to calculate the 3D shear-wave velocity model.Our results show that there is a sharp velocity contrast across the Nankou-Sunhe fault,with low velocities down to about 2 km on the hanging wall and high velocity on the footwall of the fault.According to the geological investigation,the low velocities are related to thicker sediments and Jurassic volcanic rock below which are the cap rock of the hydrothermal system.From the HVSR analysis,the HVSR curves of the sites near the fault shows double-peak,one less than 1 Hz and the other centered 7 Hz.After converting frequency to depth by the empirical equation,the results show that the thickness of sediments is thinned from southwest to northeast,which generally agrees well to field survey.Our results provide high-resolution near-surface structure for future study on disaster risk reduction and urban planning.

Modulating the photoelectrons of g-C3N4 via coupling MgTi2O5 as appropriate platform for visible-light-driven photocatalytic solar energy conversion

Graphitic carbon nitride (g-C3N4) has become an attractive visible-light-responsive photocatalyst because of its semiconductor polymer compositions and easy-modulated band structure. However, the bulk g-C3N4 photocatalyst has the low separation efficiency of photogenerated carriers and unsatisfied surface catalytic performance, which leads to poor photocatalytic performance. As for this, MgTi2O5 with high chemical stability, wide band gap and negative conduction band was used as a suitable platform for coupling with g-C3N4 to enhance charge separation and promoted the photoactivity. Different from common approaches, here, we propose an innovative method to construct g-C3N4/MgTi2O5 nanocomposites featuring “0 + 1 >1" magnification effect to improve g-C3N4 photocatalytic performance under visible light irradiation. Additionally, compositing metal oxides of MgTi2O5 with g-C3N4 has proven to be a proper strategy to accelerate surface catalytic reactions in g-C3N4, and the photoinduced carriers were modulated to maintain thermodynamic equilibrium, which convincingly promotes the photocatalytic activity. The photocatalytic performance of the nanocomposites was measured by hydrogen production and CO2 reduction under visible light. The developed g-C3N4/MgTi2O5 nanocomposites with a 5 wt.% MgTi2O5 exhibits the highest H2 and CO yield under visible light and excellent stability compare to the other MgTi2O5 contents in composites. According to surface photo-voltage spectra, electrochemical CO2 reduction, photoluminescence, etc. The superior performance can be related to an enhanced electron lifetime, the promoted charge transfer and the increased electronic separation property of g-C3N4. Our work provides an approach to overcome the defect of pure g-C3N4, which accesses to composite with the second component matched well.

Micro-Earthquake Seismicity and Tectonic Significance of the 2012 Ms 4.9 Baoying Earthquake,Jiangsu,China

On July 20,2012,the Ms 4.9 Baoying Earthquake occurred near the junction of Baoying County and Gaoyou City in Jiangsu Province,eastern China.Due to no obvious surface rupture and limited observation of earthquake sequence,the seismogenic structure of the Ms 4.9 Baoying Earthquake is still unclear.In this study,80 earthquakes provided by China Earthquake Network Center(CENC)are first relocated;and then the relocated 75 events with high signal-to-noise ratios as templates are utilized to scan through continuous waveform data(July 11 to August 31,2012)using graphics processing unit-based match and locate(GPU-M&L)technique.Then the Deep Denoiser,a deeplearning-based noise reduction technique,is used to further confirm some newly detected events;and the double-difference relocation(Hypo DD)algorithm is used to relocate the earthquakes.We detect and relocate more than twice as many events as the CENC routine catalog,which includes 15 foreshocks and 230 aftershocks.The results show that the foreshocks are mainly distributed in the NW direction along the extended SE section of the blind Xiagonghe fault(XF),which is orthogonal to the strike of the seismogenic fault of the Ms 4.9 Baoying Earthquake(Yangchacang-Sangshutou fault,named YSF).Most of the aftershocks are generally distributed along the NNE-trending YSF and illuminate a steeply dipping plane.This study reveals detailed spatiotemporal evolution of the earthquake sequence and suggests that the buried XF extends southeastward and cuts through the NNE-trending seismogenic YSF.

DCX and CRABP2 are candidate genes for differential diagnosis between pre-chemotherapy embryonic and alveolar rhabdomyosarcoma in pediatric patients

Importance Rhabdomyosarcoma(RMS)is the most common soft tissue sarcoma in children.More than 90%of cases are classified as embryonic RMS(ERMS)or alveolar RMS(ARMS).ERMS has a worse prognosis than ARMS.Early differential diagnosis is of paramount importance for optimization of treatment.Objective To identify genes that are differentially expressed between ARMS and ERMS,which can be used for accurate rhabdomyosarcoma classification.Methods Three Gene Expression Omnibus datasets composed of ARMS and ERMS samples were screened and 35 differentially expressed genes(DEGs)were identified.Receiver operating characteristic curve analysis and area under the curve analysis was performed for these 35 DEGs and seven candidate genes with the best differential expression scores between ARMS and ERMS were determined.The expression of these seven candidate genes was validated by immunohistochemical analysis of pre-chemotherapy ARMS and ERMS specimens.Results The levels of DCX and CRABP2 were confirmed to be remarkably different between paraffin-embedded ARMS and ERMS tissues,while EGFR abundance was only marginally different between these two RMS subtypes.Interpretation DCX and CRABP2 are potential biomarkers for distinguishing ARMS from ERMS in pre-chemotherapy pediatric patients.