Gauge and Lorentz Covariant Quark Propagator in an Arbitrary Gluon Field

The quark propagator in presence of an arbitrary gluon field is calculated gauge and Lorentz covariantly order by order in terms of powers of gluon field and its derivatives. The result is independent of path connecting ends of propagator and leading order result coincides with the exact propagator in the trivial case of vanishing gluon field.Comment: 9 page

A Kinetic Model for Cell Damage Caused by Oligomer Formation

It is well-known that the formation of amyloid fiber may cause invertible damage to cells, while the underlying mechanism has not been fully uncovered. In this paper, we construct a mathematical model, consisting of infinite ODEs in the form of mass-action equations together with two reaction-convection PDEs, and then simplify it to a system of 5 ODEs by using the maximum entropy principle. This model is based on four simple assumptions, one of which is that cell damage is raised by oligomers rather than mature fibrils. With the simplified model, the effects of nucleation and elongation, fragmentation, protein and seeds concentrations on amyloid formation and cell damage are extensively explored and compared with experiments. We hope that our results can provide a valuable insight into the processes of amyloid formation and cell damage thus raised.Comment: 16 pages+ 5 figures for maintext; 8 pages+ 4 figures for Supporting Material

Differential isospin-fractionation in dilute asymmetric nuclear matter

The differential isospin-fractionation (IsoF) during the liquid-gas phase transition in dilute asymmetric nuclear matter is studied as a function of nucleon momentum. Within a self-consistent thermal model it is shown that the neutron/proton ratio of the gas phase becomes {\it smaller} than that of the liquid phase for energetic nucleons, although the gas phase is overall more neutron-rich. Clear indications of the differential IsoF consistent with the thermal model predictions are demonstrated within a transport model for heavy-ion reactions. Future comparisons with experimental data will allow us to extract critical information about the momentum dependence of the isovector strong interaction.Comment: Rapid Communication, Phys. Rev. C (2007) in pres

Comparison of endostatin(endostar)and avastin's inhibition effect on mice choroidal neovascularization

AIM:To observe the inhibition effect of endostatin(endostar)on mice choroidal neovascularization model(CNV)and compare with the Avastin.<p>METHODS: Using 532nm laser photocoagulation to establish a mouse model of CNV. We observed the formation of CNV by histopathological examination after 2wk later. Forty successful models of mice were randomly divided into control group(group 1, 10 rats), normal saline group(group 2, 10 rats), endostatin group(group 3, 10 rats)and avastin group(group 4, 10 rats). The drugs were injected into the mice' vitreous after photocoagulation 2wk later. Then 1wk later, we took the mice eyeballs to perform the HE and immunohistochemical staining to observe. The statistical analysis of ANOVA was done by SPSS 16.0 and the LSD-<i>t</i> test was used for multiple samples, taking <i>P</i><0.05 as the test standards.<p>RESULTS: Two weeks later, HE histopathological examination was done, light microscope showed large amount of new vessels' formation, the positive rate for CNV was 72.8%. The blank control group compared with the normal saline group <i>P</i>>0.05, had no inhibitory effect on CNV; endostatin treated group compared with control group, <i>P</i><0.05, had a certain inhibitory effect; avastin group compared with the control group, <i>P</i><0.05, had an inhibitory effect on CNV; the LSD-<i>t</i> was performed on Avastin group and endostatin group, <i>P</i><0.05, which were statistically significant. We thought that the two drugs have different inhibitory effect on mice' CNV, because <i>(-overx)</i>_Avastin=26.90,<i>(-overx)</i>_endostatin=29.13,<i>(-overx)</i>_Avastin<<i>(-overx)</i>_endostatin, we can infer that endostar had lower inhibitory effect on mice CNV than Avastin.<p>CONCLUSION: Laser-induced CNV animal models of colored mice C57BL/6J is of short time and high rate establishment and it is an ideal model for CNV study. Endostar has certain inhibitory effect on CNV, and it is likely to become one of the important drugs for CNV-related diseases in the future

Electrons dynamics control by shaping femtosecond laser pulses in micro/nanofabrication: modeling, method, measurement and application

During femtosecond laser fabrication, photons are mainly absorbed by electrons, and the subsequent energy transfer from electrons to ions is of picosecond order. Hence, lattice motion is negligible within the femtosecond pulse duration, whereas femtosecond photon-electron interactions dominate the entire fabrication process. Therefore, femtosecond laser fabrication must be improved by controlling localized transient electron dynamics, which poses a challenge for measuring and controlling at the electron level during fabrication processes. Pump-probe spectroscopy presents a viable solution, which can be used to observe electron dynamics during a chemical reaction. In fact, femtosecond pulse durations are shorter than many physical/chemical characteristic times, which permits manipulating, adjusting, or interfering with electron dynamics. Hence, we proposed to control localized transient electron dynamics by temporally or spatially shaping femtosecond pulses, and further to modify localized transient materials properties, and then to adjust material phase change, and eventually to implement a novel fabrication method. This review covers our progresses over the past decade regarding electrons dynamics control (EDC) by shaping femtosecond laser pulses in micro/nanomanufacturing: (1) Theoretical models were developed to prove EDC feasibility and reveal its mechanisms; (2) on the basis of the theoretical predictions, many experiments are conducted to validate our EDC-based femtosecond laser fabrication method. Seven examples are reported, which proves that the proposed method can significantly improve fabrication precision, quality, throughput and repeatability and effectively control micro/nanoscale structures; (3) a multiscale measurement system was proposed and developed to study the fundamentals of EDC from the femtosecond scale to the nanosecond scale and to the millisecond scale; and (4) As an example of practical applications, our method was employed to fabricate some key structures in one of the 16 Chinese National S&T Major Projects, for which electron dynamics were measured using our multiscale measurement system