Lift-Off Effect of Koch and Circular Differential Pickup Eddy Current Probes

A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during the inspection of defects.However,the extent of the lift-off effect on differential probes,including different coil structures,varies.In this study,two planar eddy current probes with differential pickup structures and the same size,Koch and circular probes,were used to compare lift-off effects.The eddy current distributions of the probes perturbed by 0°and 90°cracks were obtained by finite element analysis.The analysis results show that the 90°crack can impede the eddy current induced by the Koch probe even further at relatively low lift-off distance.The peak-to-peak values of the signal output from the two probes were compared at different lift-off distances using finite element analysis and experimental methods.In addition,the effects of different frequencies on the lift-off were studied experimentally.The results show that the signal peak-to-peak value of the Koch probe for the inspection of cracks in 90°orientation is larger than that of the circular probe when the lift-off distance is smaller than 1.2 mm.In addition,the influence of the lift-off distance on the peak-to-peak signal value of the two probes was studied via normalization.This indicates that the influence becomes more evident with an increase in excitation frequency.This research discloses the lift-off effect of differential planar eddy current probes with different coil shapes and proves the detection merit of the Koch probe for 90°cracks at low lift-off distances.

Activatable fluorescent probes for imaging and diagnosis of rheumatoid arthritis

Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affecting locomotion ability and life quality.Consequently,good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA.Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging.Herein,we review the fluorescent probes developed for the detection and imaging of RA biomarkers,namely reactive oxygen/nitrogen species(hypochlorous acid,peroxynitrite,hydroxyl radical,nitroxyl),pH,and cysteine,and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.

Progress in Mechanical Modeling of Implantable Flexible Neural Probes

Implanted neural probes can detect weak discharges of neurons in the brain by piercing soft brain tissue,thus as important tools for brain science research,as well as diagnosis and treatment of brain diseases.However,the rigid neural probes,such as Utah arrays,Michigan probes,and metal microfilament electrodes,are mechanically unmatched with brain tissue and are prone to rejection and glial scarring after implantation,which leads to a significant degradation in the signal quality with the implantation time.In recent years,flexible neural electrodes are rapidly developed with less damage to biological tissues,excellent biocompatibility,and mechanical compliance to alleviate scarring.Among them,the mechanical modeling is important for the optimization of the structure and the implantation process.In this review,the theoretical calculation of the flexible neural probes is firstly summarized with the processes of buckling,insertion,and relative interaction with soft brain tissue for flexible probes from outside to inside.Then,the corresponding mechanical simulation methods are organized considering multiple impact factors to realize minimally invasive implantation.Finally,the technical difficulties and future trends of mechanical modeling are discussed for the next-generation flexible neural probes,which is critical to realize low-invasiveness and long-term coexistence in vivo.

Study on mutual impedance characteristics between probes in a circular waveguide

The expression of mutual impedance between two probes in a circular waveguide is derived by means of a vector potential function, reaction concept and reciprocity theorem. The waveguide is semi-infinite, and one end of the waveguide is terminated to a load with a reflection coefficient. The contribution to the mutual resistance is found to come from the dominant mode, while the contribution to the mutual reactance comes from the dominant mode and the higher order modes. The major contribution to the mutual reactance is from the dominant mode, since the higher modes decay rapidly with the increasing the probes’ of separation distance. However, as the separation distance approaches zero, the higher modes become dominant, which results in a large value of the mutual reactance. The mutual impedance is dependent on the location and height of the probes, their separation distance and the location of the terminal plane.

英汉笔译课程PROBE教学模式探究

作为本科翻译专业的一门核心课程,英汉笔译课程在培养学生英汉双语运用能力、翻译能力和跨文化能力,尤其是学生英译汉翻译实践能力作用明显。文章对“PROBE教学模式”进行概念诠释,从教学目标、课程设计、教学过程和学习评价四个方面探讨了“PROBE教学模式”在英汉笔译课程中的应用,最后提出几点建议,以期提高英汉笔译课程的教学效果。

Dot-Blot Hybridization for Detection of Five Cucurbit Viruses by Digoxigenin-Labelled cDNA Probes

Dot-blot hybridization was applied in this paper to detect five viruses infecting cucurbitaceous crops, Zuccini yellow mosaic virus （ZYMV）, Watermelon mosaic virus （WMV）, Cucumber mosaic virus （CMV）, Papaya ringspot viruswatermelon strain （PRSV-W） and Squash mosaic virus （SqMV）, as a good alternative assay in seed health test and epidemiological and transgenic research. Digoxigenin-labelled cDNA probes of the five viruses were synthesized by PCR with the specific primers and applied in dot-blot hybridization to detect five viruses in crude extraction of the infected leaves. And three SqMV probes of different lengths （0.55, 1.6, and 2.7 kb, respectively） were designed to investigate the effect of hybridization. The results showed that the sensitivity for detecting the crude extraction of infected leaves by ZYMV, WMV, CMV, PRSV-W, and SqMV was down to 1：160, 1：160, 1：320, 1：160, and 1：320, respectively. Three SqMV probes of different length showed no differences on the sensitivity and specificity. The digoxigenin-labelled probes prepared by PCR could be used for accurate and rapid identification of 5 viruses infecting cucurbitaceous crops with good stabilities, sensitivities, specificity, and reproducibilifies.

Hydroxylated graphene quantum dots as fluorescent probes for sensitive detection of metal ions

Highly sensitive methods are important for monitoring the concentration of metal ions in industrial wastewater.Here,we developed a new probe for the determination of metal ions by fluorescence quenching.The probe consists of hydroxylated graphene quantum dots(H-GQDs),prepared from GQDs by electrochemical method followed by surface hydroxylation.It is a non-reactive indicator with high sensitivity and detection limits of 0.01μM for Cu2+,0.005μM for Al3+,0.04μM for Fe3+,and 0.02μM for Cr3+.In addition,the low biotoxicity and excellent solubility of H-GQDs make them promising for application in wastewater metal ion detection.

Some Aerothermodynamic Aspects of ESA Entry Probes

Two different entry vehicles are presented here： the Inflatable Reentry and Descent Demonstrator （IRDT）, and Huygens. Both missions involve （re）entries at conditions close to orbital, and have been performed in 2005. Specific aspects of the design and the mission of IRDT are briefly outlined. The preliminary results of the recent flight of IRDT and the methodology followed at ESTEC for the assessment of radiative fluxes for Huygens are summarised.

Application of restriction display PCR technique in the preparation of cDNA microarray probes

AIM: To develop a simplified and efficient method for the preparation of hepatitis C virus (HCV) cDNA microarray probes.METHODS: With the technique of restriction display PCR (RD-PCR), restriction enzyme Sau3A I was chosen to digest the full-length HCV cDNAs. The products were classified and re-amplified by RD-PCR. We separated the differential genes by polyacrylamide gel electrophoresis and silver staining. Single bands cut out from the polyacrylamide gel were isolated. The third-round PCR was performed using the single bands as PCR template.The RD-PCR fragments were purified and cloned into the pMD18-T vector. The recombinant plasmids were extracted from positive clones, and the target gene fragments were sequenced. The cDNA microarray was prepared by spotting RD-PCR products to the surface of amino-modified glass slides using a robot. We validated the detection of microarray by hybridization and sequence analysis.RESULTS: A total of 24 different cDNA fragments ranging from 200 to 800 bp were isolated and sequenced,which were the specific gene fragments of HCV. These fragments could be further used as probes in microarray preparation. The diagnostic capability of the microarray was evaluated after the washing and scanning steps. The results of hybridization and sequence analysis showed that the specificity, sensitivity, accuracy, reproducibility,and linearity in detecting HCV RNA were satisfactory.CONCLUSION: The RD-PCR technique is of great value in obtaining a large number of size-comparable gene probes, which provides a speedy protocol in generating probes for the preparation of microarrays. Microarray prepared as such could be further optimized and applied in the clinical diagnosis of HCV.

Diagnosis of Hydrogen Plasma in a Miniature Penning Ion Source by Double Probes

Parameters of hydrogen plasma in a miniature Penning discharge ion source, including the electron temperature and the electron density, were measured by using double probes. The results indicate that the electron density increases and the electron temperature decreases with the increase in gas pressure and the discharge current. The electron temperature is about 5 - 9 eV and the electron density is 6.0× 10^13 ～ 1.2 × 10^14 m^-3 while the discharge current is in a range of 50 - 120 μA.

ND-FISH-positive oligonucleotide probes for detecting specific segments of rye (Secale cereale L.) chromosomes and new tandem repeats in rye

Rye(Secale cereale L.)has been widely used to improve wheat(Triticum aestivum L.)cultivars.Oligo probes combined with non-denaturing fluorescence in situ hybridization(ND-FISH)technology provide a convenient and efficient way to identify individual rye chromosomes.However,suitable ND-FISH-positive oligo probes for recognizing specific segments of rye chromosomes are lacking.Five new ND-FISH-positive oligo probes:Oligo-5BL.46,Oligo-5A8080,Oligo-5A8080.1,Oligo-1AL.73,and Oligo-0R3,combined with two previously reported oligo probes,Oligo-44 and Oligo-45,were used in this study.Probes Oligo-5BL.46,Oligo-5A8080 and Oligo-44 produced signals only in intercalary regions of arms 1RS,5RS,and 5RL,respectively.Probe Oligo-5A8080.1 combined with probe Oligo-45 distinguished the intercalary regions of arms 1RS,5RS,and 6RS simultaneously.Oligo-5A8080 and Oligo-5A8080.1 revealed variation in the distribution of 5S rDNA sequences and polymorphism among 5R chromosomes.Probe Oligo-1AL.73 produced signals only on chromosomes 4R and 7R and contributed to the construction of an improved FISH map of chromosome 4RKu and to the confirmation of 4RLKu breakpoints in wheat-rye 4RLKu translocation chromosomes.Oligo-0R3 produced signals in the telomeric and subtelomeric regions of 14 rye chromosomes.These oligo probes also revealed five new tandem repeats in rye.Using the oligo probes reported in this study,the short arms of 1R,5R,and 6R and the long arms of 4R and 7R can be easily discriminated when these chromosomes are broken.

Endoscopic ultrasound using ultrasound probes for the diagnosis of early esophageal and gastric cancers

Endoscopic ultrasound (EUS) devices were first designed and manufactured more than 30 years ago, and since then investigators have reported EUS is effective for determining both the staging and the depth of invasion of esophageal and gastric cancers. We review the present status, the methods, and the findings of EUS when used to diagnose and stage early esophageal and gastric cancer. EUS using high-frequency ultrasound probes is more accurate than conventional EUS for the evaluation of the depth of invasion of superficial esophageal carcinoma. The rates of accurate evaluation of the depth of invasion by EUS using high-frequency ultrasound probes were 70%-88% for intramucosal cancer, and 83%-94% for submucosal invasive cancer. But the sensitivity of EUS using high-frequency ultrasound probes for the diagnosis of submucosal invasive cancer was relatively low, making it difficult to confirm minute submucosal invasion. The accuracy of EUS using high-frequency ultrasound probes for early gastric tumor classification can be up to 80% compared with 63% for conventional EUS, although the accuracy of EUS using high-frequency ultrasound probes relatively decreases for those patients with depressed-type lesions, undifferentiated cancer, concomitant ulceration, expanded indications, type 0-I?lesions, and lesions located in the upper-third of the stomach. A 92% overall accuracy rate was achieved when both the endoscopic appearance and the findings from EUS using high-frequency ultrasound probes were considered together for tumor classification. Although EUS using high-frequency ultrasound probes has limitations, it has a high depth of invasion accuracy and is a useful procedure to distinguish lesions in the esophagus and stomach that are indicated for endoscopic resection.

Generalized Ptychography with Diverse Probes

Generalized ptychography is established with diverse probes,which not only extend the core spirit of ptychography that is the overlapping of neighboring probes,but also enhance the imaging quality.We find that in one of suggested configurations with visible light,the performances of two types of diversified probes are improved in comparison with the traditional circular probes.This may open up some new possibilities of ptychographic imaging.

Development of taxonomic rRNA-targeted probes of two harmful algae: Prorocentrum minimum and Karenia mikimotoi by fluorescence in situ hybridization

Harmful algal blooms recently have been under the spotlight throughout the world, because of their nega- tive impact on the marine environment, aquaculture, fisheries as well as public health. The development of methods for rapid and precise identification and quantification of causative species is essential for the warning and monitoring of blooms, among which the techniques based on taxonomic probes are the most favored. In this study, two harmful algae, i.e., Prorocentrum minimum and Karenia mikimotoi were tak- en into consideration. The partial large subunit rDNA （D1-D2） of both species were firstly PCR-amplified, cloned and sequenced. The obtained sequences were then introduced to carry out alignment analysis for gene specific regions. Three respective candidate probes for each species were designed and used to screen the optimal probe by performing fluorescence in situ hybridization （FISH） tests. The results showed that the probes Pmin0443 and Kmik0602 displayed the best hybridization for P. minimum and K.. mikimotoi, respectively. Both the specific （taxonomic） （Pmin0443 and Kmik0602） and the control probes （UniC0512 and UniR0499） were used for cross-reactivity tests with other microalgae in our laboratory. The probes Pmin0443 and Kmik0602 are specific and could be served as taxonomic probes introduced into the tech- niques targeting rRNA, such as FISH, sandwich hybridization, and DNA-microarray assay of P minimum and K. mikimotoi in the future. Finally, FISH analyses with both probes were performed on the simulated field samples. The probes could hybridize exclusively with the target cells well, and no significant differ- ence （p 〉0.05） was observed in the cell densities of the samples determined by FISH and light microscopy （LM）. All suggest that the probes are specific and could be introduced into FISH for the monitoring of both harmful algae.

Fiber lenses for ultra-small probes used in optical coherent tomography

We present a design, construction and characterization of different variations of GRIN and ball fiber lenses, which were recently proposed for ultra-small biomedical imaging probes. Those fiber lens modules are made of a single mode fiber and a GRIN or ball fiber lens with or without a fiber spacer between them. The lens diameters are smaller than 0.3 mm. We discuss design methods, fabrication techniques, and measuring performance of the fiber lenses. The experimental results are compared to their modeling results. The fabrication of a high quality beam director for both lens types is presented as well. These fiber integrated beam directors could be added on the tips of the fiber lenses for side-view probes. A needle probe made by these fiber lenses is demonstrated as a sample of the ultra-small probe for biomedical imaging application. In vivo human finger images acquired by a swept source optical coherence tomography using the fiber lenses with different beam profiles were shown, which indicates the important impact of

Development of oligonucleotide probes for FISH karyotyping in Haynaldia villosa,a wild relative of common wheat

Haynaldia villosa is a wild relative of wheat and a valuable gene resource for wheat improvement.Owing to the limited number of probes available for fluorescence in situ hybridization(FISH),the resolution at which the karyotype of H.villosa can be characterized is poor,hampering accurate characterization of small segmental alien introgressions.We designed ten oligonucleotide probes using tandem repeats in DNA sequences derived from the short arm of H.villosa chromosome 6 V(6 VS).FISH with seven of them resulted in clear signals on H.villosa chromosomes.Using these,we constructed FISH karyotypes for H.villosa using oligo-6 VS-1 and oligo-6 VS-35 oligonucleotides and characterized the distribution of the two probes in five different H.villosa accessions.The new FISH probes can efficiently characterize H.villosa introgressions into wheat.

Ultrasensitive Detection of Glyphosate Using CdTe Quantum Dots in Sol-Gel-Derived Silica Spheres Coated with Calix[6]arene as Fluorescent Probes

We have developed a simple method for the preparation of highly fluorescent and stable, water-soluble CdTe quantum dots in sol-gel-derived composite silica spheres which were coated with calix[6]arene. The resulting nanoparticles (NPs) were characterized in terms of UV, fluorescence and FT-IR spectroscopy and TEM. The results show that the new NPs display more intense fluorescence intensity and are more stable than its precursors of the type SiO2/CdTe. Under the optimum, the novel NPs exhibit a higher selectivity and ultrasensitive fluorescence probes for the determination of gly-phosate over other pesticides, the fluorescence intensity increase with the concentration of glyphosate in the range from 1.0 to 25.0 nmol/L and the detection limit is low to 0.0725 nmol/L. A mechanism is suggested to explain the inclusion process by a Langmuir binding isotherm.

An empirical model of the global distribution of plasmaspheric hiss based on Van Allen Probes EMFISIS measurements

Using wave measurements from the EMFISIS instrument onboard Van Allen Probes,we investigate statistically the spatial distributions of the intensity of plasmaspheric hiss waves.To reproduce these empirical results,we establish a fitting model that is a thirdorder polynomial function of L-shell,magnetic local time(MLT),magnetic latitude(MLAT),and AE*.Quantitative comparisons indicate that the model’s fitting functions can reflect favorably the major empirical features of the global distribution of hiss wave intensity,including substorm dependence and the MLT asymmetry.Our results therefore provide a useful analytic model that can be readily employed in future simulations of global radiation belt electron dynamics under the impact of plasmaspheric hiss waves in geospace.

Capture Probe: a java tool for designing probes for capture Hi-C applications

DEAR EDITOR,Many functional elements associated with traits and diseases are located in non-coding regions and act on distant target genes via chromatin looping and folding,making it difficult for scientists to reveal the genetic regulatory mechanisms.Capture Hi-C is a newly developed chromosome conformation capture technology based on hybridization capture between probes and target genomic regions.It can identify interactions among target loci and all other loci in a genome with low cost and high resolution.Here,we developed CaptureProbe,a user-friendly,graphical Java tool for the design of capture probes across a range of target sites or regions.Numerous parameters helped to achieve and optimize the designed probes.Design testing of CaptureProbe showed high efficiency in the design success ratio of target loci and probe specificity.Hence,this program will help scientists conduct genome spatial interaction research.

Characterization of Scanning SQUID Probes Based on 3D Nano-Bridge Junctions in Magnetic Field

We develop superconducting quantum interference device(SQUID)probes based on 3D nano-bridge junctions for the scanning SQUID microscopy.The use of these nano-bridge junctions enables imaging in the presence of a high magnetic field.Conventionally,a superconducting ground layer has been employed for better magnetic shielding.In our study,we prepare a number of scanning SQUID probes with and without a ground layer to evaluate their performance in external magnetic fields.The devices show the improved magnetic modulation up to 1.4 T.It is found that the ground layer reduces the inductance,and increases the modulation depth and symmetricity of the gradiometer design in the absence of the field.However,the layer is not compatible with the use of the scanning SQUID probe in the field because it decreases its working field range.Moreover,by adding the layer,the mutual inductance between the feedback coil and the SQUID also decreases linearly as a function of the field.