Universality of the Dynamic Characteristic Relationship of Electron Correlation in the Two-Photon Double Ionization Process of a Helium-Like System

Universality of the dynamic characteristic relationship between the characteristic time tc and the two-electron Coulomb interaction energy V12 of the ground state in the two-photon double ionization process is investigated via changing the parameters of the two-electron atomic system and the corresponding laser conditions.The numerical results show that the product tcV12 keeps constant around 4.1 in the cases of changing the nucleus charge,the electron charge,the electron mass,and changing simultaneously the nucleus charge and the electron charge.These results demonstrate that the dynamic characteristic relationship in the two-photon double ionization process is universal.This work sheds more light on the dynamic characteristic relationship in ultrafast processes and may find its application in measurements of attosecond pulses.

Downregulation of cold-inducible RNA-binding protein activates mitogen-activated protein kinases and impairs spermatoRenic function in mouse testes

Cold-inducible RNA-binding protein （CIRP） is an RNA-binding protein that is expressed in normal testes and downregulated after heat stress caused by cryptorchidism, varicocele or environmental temperatures. The purpose of this study was to investigate the functions of CIRP in the testes. We employed RNAi technique to knock down the expression of CIRP in the testes, and performed haematoxylin and eosin staining to evaluate morphological changes following knockdown. Germ cell apoptosis was examined by terminal deoxynucleotidal transferase-mediated dUTP nick end labelling （TUNEL） assay, and mitogen-activated protein kinase （MAPK） signalling pathways were investigated by Western blotting to determine the possible mechanism of apoptosis. We found that using siRNA is a feasible and reliable method for knocking down gene expression in the testes. Compared to controls, the mean seminiferous tubule diameter （MSTD） and the thickness of the germ cell layers decreased following siRNA treatment, whereas the percentage of apoptotic seminiferous tubules increased. The p44/p42, p38 and SAPK/JNK MAPK pathways were activated after downregulation of CIRP. In conclusion, we discovered that downregulation of CIRP resulted in increased germ cell apoptosis, possibly viathe activation of the p44/p42, p38 and SAPK/JNK MAPK pathways.

Interaction between cyclooxygenase-2,Snail,and E-cadherin in gastric cancer cells

AIM:To investigate the mechanisms of how cyclooxygenase-2(COX-2)regulates E-cadherin in gastric cancer cells.METHODS:COX-2 expression in human gastric cancer cell lines SGC-7901,BGC-823,MGC-803 and AGS were measured at the mRNA and protein level.COX-2 rich cell line SGC-7901 was chosen for subsequent experiments.siRNA mediated gene knockdown was used to investigate the impact of COX-2 on nuclear factor-κB (NF-κB),Snail,and E-cadherin in gastric cancer cells.Gene expression was determined by Western blot and real-time polymerase chain reaction.To analyze whether NF-κB inhibition could interrupt the modulatory effect of COX-2 or prostaglandin E2(PGE2)on E-cadherin,gastric cancer cells were treated with celecoxib or PGE2,in the presence of NF-κB specific siRNA.RESULTS:Highest expression level of COX-2 was found in SGC-7901 cells,both at mRNA and protein levels.siRNA mediated down-regulation of COX-2 led to a reduced expression of NF-κB and Snail,but an increased expression of E-cadherin in SGC-7901 cells.siRNA mediated down-regulation of NF-κB also led to a reduced expression of E-cadherin and Snail in SGC-7901 cells.However,COX-2 expression did not alter after cells were treated with NF-κB specific siRNA in SGC-7901 cells.Treatment of SGC-7901 cells with celecoxib led to a reduced expression of Snail but an increased expression of E-cadherin.In contrast,treatment of SGC-7901 cells with PGE2 led to an increased Snail and a decreased E-cadherin.However,siRNAmediated knockdown of NF-κB partially abolished the effect of celecoxib and PGE2 on the regulation of E-cadherin and Snail in SGC-7901 cells.CONCLUSION:COX-2 likely functions upstream of NF-κB and regulates the expression of E-cadherin via NF-κB/Snail signaling pathway in gastric cancer cells.

Function of PCA3 in prostate tissue and clinical research progress on developing a PCA3 score

Prostate cancer gene 3 （PCA3, also known as DD3） is a new biomarker that could improve the accuracy of prostate cancer diagnosis. It is a great biomarker with fairly high specificity and sensitivity. The incidence of prostate cancer is rising steadily in most countries. The commonly used prostate-specific antigen （PSA） test once gave people hope for early diagnosis of prostate cancer. However, the low specificity of the PSA test has resulted in a large number of unnecessary biopsies and overtreatment. During the past decade, many new prostate cancer biomarkers have been found. Among these, PCA3 is the most promising. Due to its great performance in distinguishing prostate cancer from other prostate conditions, PCA3 could likely be applied for early diagnosis of prostate cancer, patient follow-up, prognosis prediction, and targeted therapy. After years of research, we have obtained some knowledge about the sequence of PCA3 gene. We have also determined the relationship between PCA3 and the proliferation of prostate cancer cells and learned some information about how PCA3 affects tumor-related genes and proteins. A PCA3 score has been created, and it has been used in a variety of studies. Some researchers have even applied PCA3 to targeted therapy and obtained a good effect in vitro. This review describes the current state of research, and explores the future prospects for PCA3.

Perioperative complications of radical retropubic prostatectomy in patients with locally advanced prostate cancer： a comparison with clinically localized prostate cancer

Radical prostatectomy （RP） continues to be an effective surgical therapy for prostate carcinoma, particularly for organ-confined prostate cancer （PCa）. Recently, RP has also been used in the treatment of locally advanced prostate cancer. However, little research has been performed to elucidate the perioperative complications associated with RP in patients with clinically localized or locally advanced PCa. We sought to analyse the incidence of complications in these two groups after radical retropubic prostatectomy （RRP）. From June 2002 to July 2010, we reviewed 379 PCa patients who underwent RRP in our hospital. Among these cases, 196 had clinically localized PCa （Tla-T2c group 1）, and 183 had locally advanced PCa （ ≥ T3,： group 2）. The overall complication incidence was 21.9%, which was lower than other studies have reported. Perioperative complications in patients with locally advanced PCa mirror those in patients with clinically localized PCa （26.2% vs. 17.8%, P=0.91）. Our results showed that perioperative complications could not be regarded as a factor to consider in regarding RP in patients with cT3 or greater.

Gene Expression Profile of Human Skeletal Muscle and Adipose Tissue of Chinese Han Patients with Type 2 Diabetes Mellitus

Objective To study the differential patterns of gene expression in skeletal muscle and adipose tissue between type 2 diabetes mellitus （T2DM） patients and healthy subjects using DNA microarray analysis, Methods T2DM patiens were divided into female group, young male group and old male group. DNA microarray analysis and quantitative real-time PCR were carried out to anaIyze the relation between gene expressions and T2DM. Results The mRNA expression of 298, 578, and 350 genes was changed in the skeletal muscle of diabetes mellitus patients compared with control subjects. The 1320, 1143, and 2847 genes were modified in adipose tissue of the three groups. Among the genes surveyed, the change of 25 and 39 gene transcripts in skeletal muscle and adipose tissue was ≥2 folds, These differentially expressed genes were classified into 15 categories according to their functions. Conclusion New genes are found and T2DM can be prevented or cured.

Extreme Ultraviolet Frequency Comb with More than 100μW Average Power below 100nm

Extreme ultraviolet(XUV)frequency comb is a powerful tool in precision measurement.It also brings many new opportunities to the field of strong field physics since high harmonic generation related phenomena can be studied with high repetition rate.We demonstrate the generation of an XUV frequency comb with the aid of intra-cavity high harmonic generation process.The setup is driven by a high power infrared frequency comb,and an average power of 4.5 kW is reached in the femtosecond enhancement cavity.With Xe gas as the working media,harmonics up to the 19th order are observed.Power measurement indicates that as much as 115.9μW(1.3 mW)are generated at^94 nm(~148 nm).The shortest wavelength we can reach is^55 nm.The coherence of the generated light is tested with an optical-heterodyne-based measurement of the third harmonic.The resulted line width is^3 Hz.In addition,with this system,we also observe a strong suppression of below threshold harmonics from O2 compared to that from Xe.These results suggest that the current system is ready for precision spectroscopic measurements with few-electron atomic and molecular systems in XUV region as well as the study of strong field physics with an unprecedented 100 MHz repetition rate.

Femtosecond enhancement cavity with kilowatt average power

Femtosecond enhancement cavity(fsEC) has been proved to be a powerful tool in a diverse range of applications.Here, we report the recent progresses in building an fsEC on kilowatt level average power, with the aim of realization of intracavity high harmonic generation(HHG) and extension of the wavelength of femtosecond optical frequency comb from infrared(IR) to extreme ultraviolet(XUV). Upon mode-matching optimization and cavity length locking, an intracavity average power of 6.08 kW is reached and the corresponding buildup is 225. After introducing noble gas of Xe into the focus region, clear sign of plasma has been observed. The generated HHG is also coupled out by a sapphire plate placed at Brewster's angle for the fundamental laser. Our work paves the way for the realization of an XUV comb.

Photoacoustic and Fluorescence Spectroscopy of Metallomesogens Containing Lanthanide Ions

Metallomesogens Ln（bta）3L2 （Ln^3＋： La^3＋, Eu^3＋, and Ho^3＋; bta： benzoyltrifluoroacetonate; L： Schiff base） were prepared. Photoacoustic （PA） spectroscopy was used to study physicochemical properties of the liquid crystalline metal complexes. In the region of ligand absorption, PA intensity increases for Eu（bta）3L2, La（bta）3L2, and Ho（bta）3L2, in that order. It is found that the PA intensity of the ligand bears a relation to the intramolecular energy transfer process. For the first time, phase transitions of Eu（bta）3L2 from glass state to smectic A （SmA） phase and SmA phase to isotropic liquid are monitored by PA and fluorescence （FL） spectroscopy from two aspects： nonradiative and radiative transitions. The results show that PA technique may serve as a new tool for investigating the spectral properties and phase transitions of liquid crystals containing metal ions.

Study of Cadmium-Doped Zinc Oxide Nanocrystals with Composition and Size Dependent Band Gaps

Cadrniurn-doped zinc oxide nanocrystals in the quantum confinement region have been firstly synthesized by a fast and facile sonochernical method. The alloyed structure of the nanocrystals is confirmed by X-ray diflraction, transmission electron rnicroscopy, and infrared analysis. With the increase of cadmium to zinc molar ratio from 0 to 2.0, the crystallite sizes of the samples decrease from 5.1 nrn to 2.6 nrn, and the band gaps of the samples show a red shift then a blue shift, and a red shift again. The variations of band gaps of the samples can be interpreted by the crystallite size and the composition. It is found that both the non-therrnal equilibrium environrnent established in the sonochernical reaction and the coordination ability of triethylene glycol solvent play crucial roles in the current preparation.

One-dimensional PT-symmetric acoustic heterostructure

The explorations of parity-time(PT)-symmetric acoustics have resided at the frontier in physics,and the pre-existing accessing of exceptional points typically depends on Fabry-Perot resonances of the coupling interlayer sandwiched between balanced gain and loss components.Nevertheless,the concise PT-symmetric acoustic heterostructure,eliminating extra interactions caused by the interlayer,has not been researched in depth.Here we derive the generalized unitary relation for one-dimensional(1D)PT-symmetric heterostructure of arbitrary complexity,and demonstrate four disparate patterns of anisotropic transmission resonances(ATRs)accompanied by corresponding spontaneous phase transitions.As a special case of ATR,the occasional bidirectional transmission resonance reconsolidates the ATR frequencies that split when waves incident from opposite directions,whose spatial profiles distinguish from a unitary structure.The derived theoretical relation can serve as a predominant signature for the presence of PT symmetry and PT-symmetry-breaking transition,which may provide substantial support for the development of prototype devices with asymmetric acoustic responses.

Bohmian trajectory perspective on strong field atomic processes

The interaction of an atom with an intense laser field provides an important approach to explore the ultrafast electron dynamics and extract the information of the atomic and molecular structures with unprecedented attosecond temporal and angstrom spatial resolution. To well understand the strong field atomic processes, numerous theoretical methods have been developed, including solving the time-dependent Schr ?dinger equation(TDSE), classical and semiclassical trajectory method, quantum S-matrix theory within the strong-field approximation, etc. Recently, an alternative and complementary quantum approach, called Bohmian trajectory theory, has been successfully used in the strong-field atomic physics and an exciting progress has been achieved in the study of strong-field phenomena. In this paper, we provide an overview of the Bohmian trajectory method and its perspective on two strong field atomic processes, i.e., atomic and molecular ionization and high-order harmonic generation, respectively.

Orientation-dependent depolarization of supercontinuum in BaF2 crystal

We present a systematic investigation of the depolarization properties of a supercontinuum accompanied with femtosecond laser filamentation in barium fluoride(BaF2)crystal.It is found that the depolarization of the supercontinuum depends strongly on the crystal orientations with respect to the incident laser polarization.At most crystal orientations,the depolarization of the supercontinuum rises with the increase of the input laser energies and finally saturates.While at 45°,the depolarization of the supercontinuum is not changed and keeps nearly negligible with the increase of the input laser energies.These peculiar depolarization properties of the supercontinuum can be ascribed to the orientation dependence of the cross-polarized wave(XPW)generation and ionization-induced plasma scattering in the BaF2 crystal.

High-order harmonic generation in a two-color strong laser field with Bohmian trajectory theory

We theoretically study the high-order harmonic generation （HHG） in a two-color laser field using the Bohmian mechanics. Our results show that, for tile case of a weak second-color laser field, the simulation of the HHG with only one central Bohmian trajectory is in a good agreement with the ab initio time-dependent Schrodinger equation （TDSE） results. In contrast, with the increase of the amplitude of the second-color laser field, the HHG spectra from the single central Bohmian trajectory deviate from the TDSE results more and more significantly. By analyzing the Bohmian trajectories, we find that the significant deviation is due to the fact that the central Bohmian trajectory leaves the core quickly in the two-color laser field with the breaking of inversion symmetry. Interestingly, we find that another Bohmian trajectory with different initial position, which keeps oscillating around the core, could qualitatively well reproduce the TDSE results. Furthermore, we study the HHG spectrum in a two-color laser field with inversion symmetry and find that the HHG spectrum in TDSE can be still well simulated with the central Bohmian trajectory. These results indicate that, similar to the case of one color laser field, the HHG spectra in a two-color laser field can be also reproduced with a single Bohmian trajectory, although the initial position of the trajectory is dependent on the symmetry of the laser field. Our work thus demonstrates that Bohmian trajectory theory can be used as a promising tool in investigating the HHG process in a two-color laser field.

Clutter Suppression Method in GPR Using the Convergence of Matrix Entropy

A novel clutter suppression method in ground penetrating radar （GPR） is proposed. The preliminary result is obtained by using target resolution improved processing （TRIP）. The preliminary result will be used as an initial input for TRIP iteration. All TRIP iteration steps are the adaptive linear combination of the previous TRIP result and the preliminary result. This adaptive combination strategy can balance clutter suppression and target information protection, which is considered as a troublesome contradiction and a chronic problem in clutter suppression research. When the matrix entropy of iteration result converges, the algorithm can achieve a good result both in clutter suppression and target protection. Experimental results demonstrate that the new algorithm outperforms the existing approaches.

免疫检查点抑制剂耐药机制分析

免疫检查点抑制剂(immune checkpoint inhibitor,ICI)自问世以来用于治疗多种肿瘤,取得了一定的疗效.但是,仍有相当部分患者初始治疗无效,或出现继发耐药.近年来,免疫新药的耐药机制得以不断阐明.癌细胞和免疫细胞之间复杂的相互作用介导了耐药性的出现.肿瘤微环境、肿瘤免疫原性的异常改变,以及癌细胞信号通路的异常激活在耐药过程中发挥重要作用.恰当处理耐药有助于ICI疗效的进一步提高.免疫新药的联合治疗策略有助于减少耐药发生.本综述将讨论ICI的不同耐药机制,以及克服耐药的策略.

Microstructural evolution and sintering kinetics during spark plasma sintering of Fe and Al blended powder

The reaction diffusion between Fe and Al during spark plasma sintering(SPS)was studied.Microstructural evolution wasinvestigated by X-ray diffraction(XRD)and scanning electron microscopy(SEM)and the sintering kinetics was disclosed.The maininterphase of the SPS sample was Fe2Al5at773-873K.Ball-milling enabled a large number of lattice defects and grain boundariesthus the reaction kinetics was accelerated,although the direct current can also promote those defects.After milling,the phasetransformation kinetics was improved from0.207before mill to4.56×10-3.Besides,this work provided more details for thegeneration of Joule heating.The resistance offered to the electric path was considered to be the source of Joule heating,andparticularly the resistance offered by the different contact interfaces of die,punch,graphite foil and the sample played a leading rolefor the generation of Joule heating during spark plasma sintering.

Sapacitabine,the prodrug of CNDAC,is a nucleoside analog with a unique action mechanism of inducing DNA strand breaks

Sapacitabine is an orally bioavailable prodrug of the nucleoside analog 2'-C-cyano-2'-deoxy-1-β-D-arabino-pentofuranosylcytosine(CNDAC).Both the prodrug and active metabolite are in clinical trials for hematologic malignancies and/or solid tumors.CNDAC has a unique mechanism of action:after incorporation into DNA,it induces single-strand breaks(SSBs) that are converted into double-strand breaks(DSBs) when cells go through a second S phase.In our previous studies,we demonstrated that CNDAC-induced SSBs can be repaired by the transcription-coupled nucleotide excision repair pathway,whereas lethal DSBs are mainly repaired through homologous recombination.In the current work,we used clonogenic assays to compare the DNA damage repair mechanism of CNDAC with two other deoxycytidine analogs:cytarabine,which is used in hematologic malignacies,and gemcitabine,which shows activity in solid tumors.Deficiency in two Rad51 paralogs,Rad51D and XRCC3,greatly sensitized cells to CNDAC,but not to cytarabine or gemcitabine,indicating that homologous recombination is not a major mechanism for repairing damage caused by the latter two analogs.This study further suggests clinical activity and application of sapacitabine that is distinct from that of cytarabine or gemcitabine.

Nonadiabatic and Multielectron Effects in the Attoclock Experimental Scheme

The problem of how long it takes for an electron to tunnel from one side of a barrier to the other has been debated for decades and the attoclock is a promising experimental procedure to address this problem.In the attoclock experiment,,many physical effects will contribute to the experimental results and it is difficult to extract the t unneling time accurately.We numerically investigate a method of measuring the residual equivalent temporal offset(RETO)induced by the physical effects except for tunneling delay.The Coulomb potential effect,the nonadiabatic effect,the multielectron effect,and the Stark effect are considered in the theoretical model.It is shown that the ratio of the RETO of the target atoms to that of H is insensitive to the wavelength and is linearly proportional to(2IP)^-3/2.This work can help to improve the accuracy of the attoclock technique.

Study on application of spiral CT perfusion technology in the diagnosis of acute pancreatitis

Objective:To explore the application value of spiral CT perfusion technology in the diagnosis of acute pancreatitis (AP).Methods:A total of 78 patients with AP who were admitted in our hospital from September, 2014 to September, 2016 were included in the study. The velocity method was used to detect S-Amy and U-Amy. The emulsion enhancement velocity scattering turbidimetry was used to detect CRP. ELISA was used to detect D-D. The patients in the control group were performed with abdomen CT, while AP patients were performed with 64 slice spiral CT. The most integrated layer of pancreas display was regarded as the perfusion weighted imaging scanning layer, and CT perfusion scanning was performed. BF, BV, MTT, and PS were calculated.Results: S-Amy, U-Amy, CRP, and D-D in AP patients were significantly higher than those in the control group. With the disease progression, S-Amy and U-Amy were significantly reduced, while CRP and D-D were significantly elevated. BF and BV in AP patients were significantly lower than those in the control group, and those in SAP patients were significantly lower than those in MAP patients. With the elevation of CT grading, BF and BV were significantly reduced, while the comparison of MTT and PS among the various grading was not statistically significant.Conclusions:The pancreas perfusion in AP patients is in a low perfusion state. BF and BV are negatively correlated with the severity degree of AP, which can predict the prognosis. BF and BV in combined with the serum S-Amy, U-Amy, CRP, and D-D can provide a forceful evidence for the diagnosis, treatment, and condition evaluation of AP.