We investigate the crystal-momentum-resolved contributions to high-order harmonic generation in laser-driven graphene by semi-conductor Bloch equations in the velocity gauge.It is shown that each harmonic is generated...We investigate the crystal-momentum-resolved contributions to high-order harmonic generation in laser-driven graphene by semi-conductor Bloch equations in the velocity gauge.It is shown that each harmonic is generated by electrons with the specific initial crystal momentum.The higher harmonics are primarily contributed by the electrons of larger initial crystal momentum because they possess larger instantaneous energies during the intraband motion.Particularly,we observe circular interference fringes in the crystal-momentum-resolved harmonics spectrum,which result from the inter-cycle interference of harmonic generation.These circular fringes will disappear if the inter-cycle interference is disrupted by the strong dephasing effect.Our findings can help to better analyze the mechanism of high harmonics in graphene.展开更多
We theoretically investigate terahertz emission from solid materials pumped by intense two-color femtosecond laser field in the presence of decoherence effects.Quantum-mechanical simulations are based on the length ga...We theoretically investigate terahertz emission from solid materials pumped by intense two-color femtosecond laser field in the presence of decoherence effects.Quantum-mechanical simulations are based on the length gauge semiconductor Bloch equations describing the optical excitation and decoherence with phenomenological dephasing and depopulation times.Contributions of interband and intraband mechanisms are identified in time domain,and the latter has dominated THz generation in solid-state systems.It is found that dephasing is crucial for enhancing asymmetric intraband current and deduced that solid-state materials with short dephasing time and long depopulation time would be optimal selection for strong-field terahertz generation experiments.展开更多
Using one-dimensional semiconductor Bloch equations,we investigate the multiband dynamics of electrons in a cutoff extension scheme employing an infrared pulse with additional UV injection.An extended three-step model...Using one-dimensional semiconductor Bloch equations,we investigate the multiband dynamics of electrons in a cutoff extension scheme employing an infrared pulse with additional UV injection.An extended three-step model is firstly validated to play a dominant role in emitting harmonics in the second plateau.Surprisingly,further analysis employing the acceleration theorem shows that,though harmonics in both the primary and secondary present positive and negative chirps,the positive(negative) chirp in the first region is related to the so-called short(long) trajectory,while that in the second region is emitted through ’general’ trajectory,where electrons tunneling earlier and recombining earlier contribute significantly.The novel characteristics deepen the understanding of high harmonic generation in solids and may have great significance in attosecond science and reconstruction of band dispersion beyond the band edge.展开更多
The p53 pathway is a highly complex signaling network including several key regulators.HAUSP is a critical component of the p53 pathway acting as a deubiquitinase for both p53 and its key repressor Mdm2.Here,we identi...The p53 pathway is a highly complex signaling network including several key regulators.HAUSP is a critical component of the p53 pathway acting as a deubiquitinase for both p53 and its key repressor Mdm2.Here,we identified a novel HAUSP-interacting protein,HLA-B-associated transcript 3(Bat3)and found it to be capable of inducing p53 stabilization and activation via a HAUSP-dependent mechanism,resulting in cell growth inhibition.Surprisingly,the deubiquitylating enzymatic activity of HAUSP was not required for this phenomenon.Co-immunoprecipitation showed that p53 coexisted in a complex with Bat3 and HAUSP in vivo,and HAUSP may serve as a binding mediator to enhance the interaction between p53 and Bat3.Further studies revealed that formation of this three-protein complex interfered with the binding of p53 to its proteasome receptor S5a and promoted the accumulation of p53 in nucleus.Notably,Mdm2 protein abundance is also regulated by Bat3 in the presence of HAUSP.Overexpression of Bat3 and HAUSP increases Mdm2 protein levels without influencing the p53–Mdm2 interaction and Mdm2-mediated p53 ubiquitination,indicating that Bat3–HAUSP-mediated protein stabilization is not specific to p53 and different mechanisms may be involved in Bat3-mediated regulation of p53–Mdm2 pathway.Together,our study unravels a novel mechanism by which p53 is stabilized and activated by HAUSP-mediated interaction with Bat3 and implies that Bat3 might function as a tumor suppressor through the stabilization of p53.展开更多
Aim:Meningeal carcinomatosis is a special type of malignant tumor characterized by short survival and poor prognosis.In the present study,the authors aim to analyze the clinical,laboratory data and prognosis of mening...Aim:Meningeal carcinomatosis is a special type of malignant tumor characterized by short survival and poor prognosis.In the present study,the authors aim to analyze the clinical,laboratory data and prognosis of meningeal carcinomatosis patients.Methods:The authors enrolled 77 cases of meningeal carcinomatosis from 2003 to 2013 in the First Hospital of Jilin University.The clinical data including age,gender,symptoms at onset,clinical manifestations,primary tumors and the laboratory data including cerebrospinal fluid (CSF),tumor markers as well as the imaging data were analyzed.The interval between the onset of primary tumor and the onset of central nervous symptoms,treatments and survival time were also analyzed.Results:The onset of meningeal carcinomatosis was usually acute (46.2%) or subacute (39.0%).The most frequent symptom at onset was intracranial hypertension (70.1%).Symptoms such as headache,vomit and high lumbar puncture intracranial pressure was observed in 56% of cases during the course of the disease.CSF abnormalities such as higher protein concentration (73.4%),more CSF pleocitosis (57.1%) and lower glucose levels (48.4%) were found in 95.3% of meningeal carcinomatosis patients.Non-contrast enhanced cerebral magnetic resonance imaging (MRI) showed that 13.2% patients had abnormal meningeal changes while in the enhancement scan 35.3% patients showed changes.The serum tumor markers increased in 84% of the patients.There were no differences regarding the mean survival between patients who received intrathecal chemotherapy and those who received brain radiotherapy or supportive treatment.Conclusion:The most common clinical manifestation of meningeal carcinomatosis is intracranial hypertension.The most common primary tumor is lung cancer,followed by gastric cancer and breast cancer.The linear enhancement of meningeal on the MRI scan is of great importance for the diagnosis of meningeal carcinomatosis.展开更多
基金the National Key R&D Program of China(Grant No.2019YFA0307703)the National Natural Science Foundation of China(Grant Nos.12234020 and 12274384)the Major Research Plan of the National Natural Science Foundation of China(Grant No.91850201)。
文摘We investigate the crystal-momentum-resolved contributions to high-order harmonic generation in laser-driven graphene by semi-conductor Bloch equations in the velocity gauge.It is shown that each harmonic is generated by electrons with the specific initial crystal momentum.The higher harmonics are primarily contributed by the electrons of larger initial crystal momentum because they possess larger instantaneous energies during the intraband motion.Particularly,we observe circular interference fringes in the crystal-momentum-resolved harmonics spectrum,which result from the inter-cycle interference of harmonic generation.These circular fringes will disappear if the inter-cycle interference is disrupted by the strong dephasing effect.Our findings can help to better analyze the mechanism of high harmonics in graphene.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFA0307704)the National Natural Science Foundation of China(Grant Nos.91850201,U1830206,11974426,11974425,11874425,11774428,and 12074431)。
文摘We theoretically investigate terahertz emission from solid materials pumped by intense two-color femtosecond laser field in the presence of decoherence effects.Quantum-mechanical simulations are based on the length gauge semiconductor Bloch equations describing the optical excitation and decoherence with phenomenological dephasing and depopulation times.Contributions of interband and intraband mechanisms are identified in time domain,and the latter has dominated THz generation in solid-state systems.It is found that dephasing is crucial for enhancing asymmetric intraband current and deduced that solid-state materials with short dephasing time and long depopulation time would be optimal selection for strong-field terahertz generation experiments.
基金supported by the National Key R&D Program of China (Grant No. 2019YFA0307703)the National Natural Science Foundation of China (Grant Nos. 12234020, 12274461, and 11904400)the Major Research Plan of the National Natural Science Foundation of China (Grant No. 91850201)。
文摘Using one-dimensional semiconductor Bloch equations,we investigate the multiband dynamics of electrons in a cutoff extension scheme employing an infrared pulse with additional UV injection.An extended three-step model is firstly validated to play a dominant role in emitting harmonics in the second plateau.Surprisingly,further analysis employing the acceleration theorem shows that,though harmonics in both the primary and secondary present positive and negative chirps,the positive(negative) chirp in the first region is related to the so-called short(long) trajectory,while that in the second region is emitted through ’general’ trajectory,where electrons tunneling earlier and recombining earlier contribute significantly.The novel characteristics deepen the understanding of high harmonic generation in solids and may have great significance in attosecond science and reconstruction of band dispersion beyond the band edge.
基金This work was supported by the National Natural Science Foundation of China(31500703,31371351,and 31671488)the Program for New Century Excellent Talents in University of China(NCET-09-0737).
文摘The p53 pathway is a highly complex signaling network including several key regulators.HAUSP is a critical component of the p53 pathway acting as a deubiquitinase for both p53 and its key repressor Mdm2.Here,we identified a novel HAUSP-interacting protein,HLA-B-associated transcript 3(Bat3)and found it to be capable of inducing p53 stabilization and activation via a HAUSP-dependent mechanism,resulting in cell growth inhibition.Surprisingly,the deubiquitylating enzymatic activity of HAUSP was not required for this phenomenon.Co-immunoprecipitation showed that p53 coexisted in a complex with Bat3 and HAUSP in vivo,and HAUSP may serve as a binding mediator to enhance the interaction between p53 and Bat3.Further studies revealed that formation of this three-protein complex interfered with the binding of p53 to its proteasome receptor S5a and promoted the accumulation of p53 in nucleus.Notably,Mdm2 protein abundance is also regulated by Bat3 in the presence of HAUSP.Overexpression of Bat3 and HAUSP increases Mdm2 protein levels without influencing the p53–Mdm2 interaction and Mdm2-mediated p53 ubiquitination,indicating that Bat3–HAUSP-mediated protein stabilization is not specific to p53 and different mechanisms may be involved in Bat3-mediated regulation of p53–Mdm2 pathway.Together,our study unravels a novel mechanism by which p53 is stabilized and activated by HAUSP-mediated interaction with Bat3 and implies that Bat3 might function as a tumor suppressor through the stabilization of p53.
文摘Aim:Meningeal carcinomatosis is a special type of malignant tumor characterized by short survival and poor prognosis.In the present study,the authors aim to analyze the clinical,laboratory data and prognosis of meningeal carcinomatosis patients.Methods:The authors enrolled 77 cases of meningeal carcinomatosis from 2003 to 2013 in the First Hospital of Jilin University.The clinical data including age,gender,symptoms at onset,clinical manifestations,primary tumors and the laboratory data including cerebrospinal fluid (CSF),tumor markers as well as the imaging data were analyzed.The interval between the onset of primary tumor and the onset of central nervous symptoms,treatments and survival time were also analyzed.Results:The onset of meningeal carcinomatosis was usually acute (46.2%) or subacute (39.0%).The most frequent symptom at onset was intracranial hypertension (70.1%).Symptoms such as headache,vomit and high lumbar puncture intracranial pressure was observed in 56% of cases during the course of the disease.CSF abnormalities such as higher protein concentration (73.4%),more CSF pleocitosis (57.1%) and lower glucose levels (48.4%) were found in 95.3% of meningeal carcinomatosis patients.Non-contrast enhanced cerebral magnetic resonance imaging (MRI) showed that 13.2% patients had abnormal meningeal changes while in the enhancement scan 35.3% patients showed changes.The serum tumor markers increased in 84% of the patients.There were no differences regarding the mean survival between patients who received intrathecal chemotherapy and those who received brain radiotherapy or supportive treatment.Conclusion:The most common clinical manifestation of meningeal carcinomatosis is intracranial hypertension.The most common primary tumor is lung cancer,followed by gastric cancer and breast cancer.The linear enhancement of meningeal on the MRI scan is of great importance for the diagnosis of meningeal carcinomatosis.
