Accessing the spectrum of a single-photon by the Hong-Ou-Mandel interference.

We present and experimentally demonstrate a method for determining the spectral characterization of a single-photon state. This technique is based on the Hong-Ou-Mandel interference between a well-defined weak coherent state and a measured single-photon state. We estimate the spectrum of the single-photon state by fitting the measured interference dip with proposed model and least square method. Our method is particularly useful for characterising spectral property the single-photon state. It opens a way for robust and efficient on-line monitoring the single-photon emitters.

Characterization of two-photon interference between a weak coherent state and a heralded single photon state.

We experimentally investigate two-photon interference between a weak coherent state and a heralded single-photon state, producing from a spontaneous parametric down conversion. Both the unequal spectrum linewidth and average photon number ratio in a given time interval are considered in our model. We obtained excellent agreement between our experimental data and prediction from our model. Furthermore, the range of observing high visibility two-photon interference is significantly extended by isolating coincidence events from two-photon contributions in the weak coherent state. These results may throw some new light on quantum information technology when the two-photon interference with independent sources is required.

Fast thermal aberration model for lithographic projection lenses.

A novel fast thermal aberration model for lithographic projection lenses is proposed. In the model, optical intensity calculation is simplified by using pupil intensity mapping, and simplified formulas for temperature calculation are derived to realize fast simulation of thermal aberration. The simulation results using the proposed model are compared with that of experiments carried out on a commercial lithography tool. The R-square of the simulation is better than 0.99 and the simulation time is about 10 minutes. Experiments and simulations show that the model is capable of predicting the thermal aberration or the variation trend of the thermal aberration of lithographic projection lenses fast and accurately. The model is applicable in projection lens design, evaluating degree of production risk posed by thermal aberration, etc.

[Clinical Value of Peripheral Blood Circulating Tumor Cells Detection in Early Cervical Infiltrating Carcinoma Screening].

OBJECTIVE: To observe the difference of circulating tumor cells (CTC) in peripheral blood of patients with different degrees of cervical lesions, and to evaluate the effectiveness of CTC detection in screening early invasive cervical cancer. METHODS: From December 2015 to October 2017, 63 cases of cervicitis, low-grade and high-grade intraepithelial lesions (LSIL, HSIL) and early invasive cervical cancer were confirmed by histopathological and clinical stages in Zhongshan Boai Hospital and Zhongshan Hospital Affiliated to Zhongshan University. The immunomagnetic bead negative enrichment technique combined with immunofluorescence was used. In situ hybridization (imFISH) was used to detect CTC in peripheral blood of patients. The positive rate and quantity of CTC in four groups were analyzed. The diagnostic efficacy of CTC in early invasive cervical cancer was evaluated based on the results of histopathological diagnosis and clinical staging. RESULTS: ①The positive rates of CTC in cervicitis group, LSIL group, HSIL group and early invasive cervical cancer group were 0, 0, 19.05% and 84.13% respectively. The overall difference was statistically significant ( χ 2=504.00， P<0.05). The positive rate of CTC in early invasive cervical cancer group was higher than that in other groups ( P<0.008 3). The positive rates of CTC in HSIL group were significantly different from those in LSIL group and cervicitis group ( P<0.008 3). ②The average number (median) of CTC positive in cervicitis group, LSIL group, HSIL group and early invasive cervical cancer group was 0, 0, 1/4 mL, 3/4 mL, respectively. The average number of positive CTC in early invasive cervical cancer group was higher than that in other groups, and the difference was significant compared with other groups ( P<0.008 3). The average number of CTC positive in HSIL group was significantly different from that in LSIL and cervicitis group ( P<0.008 3). ③The sensitivity, specificity, coincidence rate, positive predictive value and negative predictive value of CTC positive results in the diagnosis of early invasive cervical cancer were 84.13%, 93.65%, 91.27%, 81.54% and 94.65%, respectively. CONCLUSION: CTC exists in patients with HSIL and early invasive cervical cancer. With the aggravation of cervical lesions, the positive rate and number of CTC test results increase. CTC detection in early invasive cervical cancer screening has a certain practical value in clinic.

[Paraffin section thickness in immunohistochemical detection of p16 expression in cervical tissue samples].

OBJECTIVE: To investigate paraffin section thickness in immunohistochemical detection of p16 expression in cervical tissue samples. METHODS: p16 immunohistochemical staining was performed in 150 cases of chronic cervicitis, 126 cases of low-grade squamous intraepithelial lesions(LSIL), 96 cases of high-grade squamous intraepithelial lesions (HSIL) and 78 cases of cervical cancer from January 2014 to March 2018 in Zhongshan Boai Hospital. The results of p16 protein expression in paraffin sections with thickness of 2, 3, 4, 5 and 6 µm were compared using Logistic regression analysis. RESULTS: With the increase of slice thickness, the staining of p16 protein in nucleus gradually increased. The thickness of cervical slices in chronic cervicitis and cervical cancer samples had no significant effect on the positive rate of p16 protein(χ2=7.817 and 1.332, both P>0.05), while the thickness of slices in LSIL and HSIL samples had significant effect on the positive rate of p16 protein (χ2=17.688 and 10.182, P<0.05 or P<0.01). The stable and reliable results were obtained when the slices were between 3 and 5 µm thick. CONCLUSIONS: Paraffin sections with thickness of 3.0-5.0 µm are recommended for immnohistochemical staining of p16 protein in cervical tissue samples.

[Volume of 4% neutral buffered formaldehyde affects the results of HER2 gene detected by fluorescence in situ hybridization in primary invasive breast cancer].

OBJECTIVE: To investigate the effects of the volume of 4% neutral phosphate buffered formalin fixative solution on the detection of human epidermal growth factor receptor 2 (HER2) gene by fluorescence in situ hybridization (FISH) in primary invasive breast cancer. METHODS: Tissue samples were collected from 109 patients with primary invasive breast cancer admitted in Zhongshan Boai Hospital from June 2014 to October 2016. The ratios of 4% phosphate buffered formalin fixative solution to sample volume samples were 3:1, 6:1, 9:1, 10:1, 15:1, 20:1 or 25:1 (groups A, B, C, D, E, F and G), respectively. Paraffin sections were made after 15 h of fixation. The amplification of HER2 gene was detected by FISH. The gene amplification results of HER2 were observed and compared in different groups. RESULTS: Fluorescence microscope showed that the tissue contour in groups A, B and C was vague, cell debris appeared, and the probe was positioned poorly; while the tissue contour was clear and complete in groups D, E, F and G and the probe was positioned accurately. The positive rate of HER2 was gradually increased from group A to D(χ2=8.601, P<0.01), and that remained stable at 24.77% in groups D to G. The positive rate of gene amplification in groups D, E, F and G was significantly higher than that in groups A, B and C (all P<0.05). CONCLUSIONS: When using FISH to detect HER2 gene in samples of primary breast invasive carcinoma, the volume of fixative solution should be at least 10 times of the sample volume to obtain accurate and stable results.

Wavefront aberration measurement method for a hyper-NA lithographic projection lens based on principal component analysis of an aerial image.

A wavefront aberration measurement method for a hyper-NA lithographic projection lens by use of an aerial image based on principal component analysis is proposed. Aerial images of the hyper-NA lithographic projection lens are expressed accurately by using polarized light and a vector imaging model, as well as by considering the polarization properties. As a result, the wavefront aberrations of the hyper-NA lithographic projection lens are measured accurately. The lithographic simulator PROLITH is used to validate the accuracies of the wavefront aberration measurement and analyze the impact of the polarization rotation of illumination on the accuracy of the wavefront aberration measurement, as well as the degree of polarized light and the sample interval of aerial images. The result shows that the proposed method can retrieve 33 terms of Zernike coefficients (Z5-Z37) with a maximum error of less than 0.00085λ.

Efficient synthesis and anti-fungal activity of oleanolic acid oxime esters.

In order to develop potential glucosamine-6-phosphate synthase inhibitors and anti-fungal agents, twenty five oleanolic acid oxime esters were synthesized in an efficient way. The structures of the new compounds were confirmed by MS, HRMS, 1H-NMR and 13C-NMR. Preliminary studies based on means of the Elson-Morgan method indicated that many compounds exhibited some inhibitory activity of glucosamine-6-phosphate synthase (GlmS), and the original fungicidal activities results showed that some of the compounds exhibited good fungicidal activities towards Sclerotinia sclerotiorum (Lib.) de Bary, Rhizoctonia solani Kuhn and Botrytis cinerea Pers at the concentration of 50 µg/mL. These compounds would thus merit further study and development as antifungal agents.

In situ aberration measurement technique based on principal component analysis of aerial image.

We propose a novel in situ aberration measurement technique for lithographic projection lens by use of aerial image based on principal component analysis (AMAI-PCA). The aerial image space, principal component space and Zernike space are introduced to create a transformation model between aerial images and Zernike coefficients. First the aberration-induced aerial images of measurement marks are simulated to form an aerial image space with a statistical Box-Behnken design pattern. The aerial image space is then represented by their principal components based on principal component analysis. The principal component coefficients of the aerial images are finally connected with Zernike coefficients by a regression matrix through regression analysis. Therefore in situ aberration measurement can be achieved based on the regression matrix and the principal component coefficients of the detected aerial images. The measurement performance of the proposed AMAI-PCA technique is demonstrated superior compared to that of the conventional TAMIS technique by using a lithographic simulator tool (Prolith). We also tested the actual performance of AMAI-PCA technique on a prototype wafer exposure tool. The testing results show our proposed technique can rapidly measure the aberrations up to high-order Zernike polynomial term with 1σ repeatability of 0.5 nm to 2.3 nm depending on the aberration type and range.

Even aberration measurement of lithographic projection optics based on intensity difference of adjacent peaks in alternating phase-shifting mask image.

We propose an in situ technique for measuring an even aberration of lithographic projection optics. By using the Hopkins theory of partially coherent imaging and the thick-mask model, the linear relationship between the intensity difference of adjacent peaks in an alternating phase-shifting mask image and an even aberration is established by equations and verified by numerical results. The sensitivity of measuring the even aberration of lithographic projection optics based on this linear relationship is analyzed, and the measurement mark is designed accordingly. Measurement performance of the present technique is evaluated using the lithographic simulator PROLITH, which shows that the present technique is capable of measuring the even aberration of lithographic projection optics with ultrahigh measurement accuracy.

Translational-symmetry alternating phase shifting mask grating mark used in a linear measurement model of lithographic projection lens aberrations.

A linear measurement model of lithographic projection lens aberrations is studied numerically based on the Hopkins theory of partially-coherent imaging and positive resist optical lithography (PROLITH) simulation. In this linearity model, the correlation between the mark's structure and its sensitivities to aberrations is analyzed. A method to design a mark with high sensitivity is proved and declared. By use of this method, a translational-symmetry alternating phase shifting mask (Alt-PSM) grating mark is redesigned with all of the even orders, +/-3rd and +/-5th order diffraction light missing. In the evaluation simulation, the measurement accuracies of aberrations prove to be enhanced apparently by use of the redesigned mark instead of the old ones.