Recent type Ia supernovas data seemingly favor a dark energy model whose equation of state w（z） crosses -1 very recently, which is a much more amazing problem than the acceleration of the universe. In this paper we ...Recent type Ia supernovas data seemingly favor a dark energy model whose equation of state w（z） crosses -1 very recently, which is a much more amazing problem than the acceleration of the universe. In this paper we show that it is possible to realize such a crossing without introducing any phantom component in a Gauss-Bonnet brane worm with induced gravity, where a four-dimensional curvature scalar on the brahe and a five-dimensional Gauss-Bonnet term in the bu/k are present. In this realization, the Gauss-Bonnet term and the mass parameter in the bulk play a crucial role.展开更多
We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain...We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological parameters using 52 current Hubble parameter data including the Hubble constant measurement from the Hubble Space Telescope. Then we simulate the baryon acoustic oscillation signals from WFIRST(Wide-Field Infrared Survey Telescope) covering the redshift range of z ∈ [0.5, 2] and the redshift drift data from E-ELT(European Extremely Large Telescope) in the redshift range of z ∈ [2, 5]. It is shown that solely using the current Hubble parameter data could give fairly good constraints on cosmological parameters. Compared to the current Hubble parameter data, with the WFIRST observation the H(z) constraints on dark energy would be improved slightly, while with the E-ELT observation the H(z) constraints on dark energy is enormously improved.展开更多
Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary av...Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary avenue to explore the pre-inflationary dynamics. Brans-Dicke(BD) loop quantum cosmology(LQC) is one of such theories whose effective background dynamics is considered in this article. Starting with a quantum bounce, we explore the pre-inflationary dynamics of a universe sourced by a scalar field with the Starobinsky potential in BD-LQC. Our study is based on the idea that though Einstein’s and Jordan’s frames are classically equivalent up to a conformal transformation in BD theory, this is no longer true after quantization. Taking the Jordan frame as the physical one we explore in detail the bouncing scenario which is followed by a phase of a slow roll inflation. The three phases of the evolution of the universe, namely, bouncing, transition from quantum bounce to classical universe, and the slow roll inflation, are noted for an initially kinetic energy dominated bounce. In addition, to be consistent with observations, we also identify the allowed phase space of initial conditions that would produce at least 60 e-folds of expansion during the slow roll inflation.展开更多
The sequencing of complete human genome revolutionized the genomic medicine.However,the complex interplay of gene-environment-lifestyle and influence of non-coding genomic regions on human health remain largely unexpl...The sequencing of complete human genome revolutionized the genomic medicine.However,the complex interplay of gene-environment-lifestyle and influence of non-coding genomic regions on human health remain largely unexplored.Genomic medicine has great potential for diagnoses or disease prediction,disease prevention and,targeted treatment.However,many of the promising tools of genomic medicine are still in their infancy and their application may be limited because of the limited knowledge we have that precludes its use in many clinical settings.In this review article,we have reviewed the evolution of genomic methodologies/tools,their limitations,and scope,for current and future clinical application.展开更多
BACKGROUND Prolonged cardiac arrest(CA)produces extensive neuronal death and microglial proliferation and activation resulting in neuro-cognitive disabilities.Among other potential mechanisms,microglia have been impli...BACKGROUND Prolonged cardiac arrest(CA)produces extensive neuronal death and microglial proliferation and activation resulting in neuro-cognitive disabilities.Among other potential mechanisms,microglia have been implicated as triggers of neuronal death after hypoxic-ischemic insults.Minocycline is neuroprotective in some brain ischemia models,either by blunting the microglial response or by a direct effect on neurons.AIM To improve survival,attenuate neurologic deficits,neuroinflammation,and histological damage after ventricular fibrillation(VF)CA in rats.METHODS Adult male isoflurane-anesthetized rats were subjected to 6 min VF CA followed by 2 min resuscitation including chest compression,epinephrine,bicarbonate,and defibrillation.After return of spontaneous circulation(ROSC),rats were randomized to two groups:(1)Minocycline 90 mg/kg intraperitoneally(i.p.)at 15 min ROSC,followed by 22.5 mg/kg i.p.every 12 h for 72 h;and(2)Controls,receiving the same volume of vehicle(phosphate-buffered saline).The rats were kept normothermic during the postoperative course.Neurologic injury was assessed daily using Overall Performance Category(OPC;1=normal,5=dead)and Neurologic Deficit Score(NDS;0%=normal,100%=dead).Rats were sacrificed at 72 h.Neuronal degeneration(Fluoro-Jade C staining)and microglia proliferation(anti-Iba-1 staining)were quantified in four selectively vulnerable brain regions(hippocampus,striatum,cerebellum,cortex)by three independent reviewers masked to the group assignment.RESULTS In the minocycline group,8 out of 14 rats survived to 72 h compared to 8 out of 19 rats in the control group(P=0.46).The degree of neurologic deficit at 72 h[median,(interquartile range)]was not different between survivors in minocycline vs controls:OPC 1.5(1-2.75)vs 2(1.25-3),P=0.442;NDS 12(2-20)vs 17(7-51),P=0.328)or between all studied rats.The number of degenerating neurons(minocycline vs controls,mean±SEM:Hippocampus 58±8 vs 76±8;striatum 121±43 vs 153±32;cerebellum 20±7 vs 22±8;cortex 0±0 vs 0±0)or proliferating microglia(hippocampus 157±15 vs 193 cortex 0±0 vs 0±0;16;striatum 150±22 vs 161±23;cerebellum 20±7 vs 22±8;cortex 26±6 vs 31±7)was not different between groups in any region(all P>0.05).Numerically,there were approximately 20%less degenerating neurons and proliferating microglia in the hippocampus and striatum in the minocycline group,with a consistent pattern of histological damage across the individual regions of interest.CONCLUSION Minocycline did not improve survival and failed to confer substantial benefits on neurologic function,neuronal loss or microglial proliferation across multiple brain regions in our model of rat VF CA.展开更多
In this paper we analyze and discuss 2D Jackiw-Teitelboim(JT)gravity coupled to primary fermion fields in asymptotically anti-de Sitter(AdS)spacetimes.We obtain a particular solution of the massless Dirac field outsid...In this paper we analyze and discuss 2D Jackiw-Teitelboim(JT)gravity coupled to primary fermion fields in asymptotically anti-de Sitter(AdS)spacetimes.We obtain a particular solution of the massless Dirac field outside the extremal black hole horizon and find the solution for the dilaton in JT gravity.As two dimensional JT gravity spacetime is conformally flat,we calculate the two point correlators of primary fermion fields under the Weyl transformations.The primary goal of this work is to present a standard technique,called resolvent,rather than using CFT methods.We redefine the fields in terms of the conformal factor as fermion fields and use the resolvent technique to derive the renormalized entanglement entropy for massless Dirac fields in JT gravity.展开更多
文摘Recent type Ia supernovas data seemingly favor a dark energy model whose equation of state w（z） crosses -1 very recently, which is a much more amazing problem than the acceleration of the universe. In this paper we show that it is possible to realize such a crossing without introducing any phantom component in a Gauss-Bonnet brane worm with induced gravity, where a four-dimensional curvature scalar on the brahe and a five-dimensional Gauss-Bonnet term in the bu/k are present. In this realization, the Gauss-Bonnet term and the mass parameter in the bulk play a crucial role.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11522540,11690021,11375153,11675145the National Program for Support of Top-Notch Young Professionalsthe 2016 Program for Postdoctoral Fellowship of Zhejiang Province
文摘We constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological parameters using 52 current Hubble parameter data including the Hubble constant measurement from the Hubble Space Telescope. Then we simulate the baryon acoustic oscillation signals from WFIRST(Wide-Field Infrared Survey Telescope) covering the redshift range of z ∈ [0.5, 2] and the redshift drift data from E-ELT(European Extremely Large Telescope) in the redshift range of z ∈ [2, 5]. It is shown that solely using the current Hubble parameter data could give fairly good constraints on cosmological parameters. Compared to the current Hubble parameter data, with the WFIRST observation the H(z) constraints on dark energy would be improved slightly, while with the E-ELT observation the H(z) constraints on dark energy is enormously improved.
基金Supported in part by the National Natural Science Foundation of China(NNSCF)under Grant Nos.11375153 and 11675145T.Z.is supported in part by NFSC under Grant No.11675143the Fundamental Research Funds for the Provincial Universities of Zhejiang in China under Grant No.RF-A2019015
文摘Recently the background independent nonperturbative quantization has been extended to various theories of gravity and the corresponding quantum effective cosmology has been derived, which provides us with necessary avenue to explore the pre-inflationary dynamics. Brans-Dicke(BD) loop quantum cosmology(LQC) is one of such theories whose effective background dynamics is considered in this article. Starting with a quantum bounce, we explore the pre-inflationary dynamics of a universe sourced by a scalar field with the Starobinsky potential in BD-LQC. Our study is based on the idea that though Einstein’s and Jordan’s frames are classically equivalent up to a conformal transformation in BD theory, this is no longer true after quantization. Taking the Jordan frame as the physical one we explore in detail the bouncing scenario which is followed by a phase of a slow roll inflation. The three phases of the evolution of the universe, namely, bouncing, transition from quantum bounce to classical universe, and the slow roll inflation, are noted for an initially kinetic energy dominated bounce. In addition, to be consistent with observations, we also identify the allowed phase space of initial conditions that would produce at least 60 e-folds of expansion during the slow roll inflation.
文摘The sequencing of complete human genome revolutionized the genomic medicine.However,the complex interplay of gene-environment-lifestyle and influence of non-coding genomic regions on human health remain largely unexplored.Genomic medicine has great potential for diagnoses or disease prediction,disease prevention and,targeted treatment.However,many of the promising tools of genomic medicine are still in their infancy and their application may be limited because of the limited knowledge we have that precludes its use in many clinical settings.In this review article,we have reviewed the evolution of genomic methodologies/tools,their limitations,and scope,for current and future clinical application.
基金Supported by the Laerdal Foundation for Acute Medicine to Janata Athe Erwin Schroedinger Stipend by the Austrian Science Fund(#J 2931-818)to Janata A+3 种基金Medical Student Anesthesia Research Foundation Award from the International Anesthesia Research Society to Wilson CDSeed Grant from The Department of Anesthesiology,University of Pittsburgh to Drabek TStarter Grant from the Society of Cardiovascular Anesthesiologists to Drabek Tthe Laerdal Foundation for Acute Medicine to Drabek T
文摘BACKGROUND Prolonged cardiac arrest(CA)produces extensive neuronal death and microglial proliferation and activation resulting in neuro-cognitive disabilities.Among other potential mechanisms,microglia have been implicated as triggers of neuronal death after hypoxic-ischemic insults.Minocycline is neuroprotective in some brain ischemia models,either by blunting the microglial response or by a direct effect on neurons.AIM To improve survival,attenuate neurologic deficits,neuroinflammation,and histological damage after ventricular fibrillation(VF)CA in rats.METHODS Adult male isoflurane-anesthetized rats were subjected to 6 min VF CA followed by 2 min resuscitation including chest compression,epinephrine,bicarbonate,and defibrillation.After return of spontaneous circulation(ROSC),rats were randomized to two groups:(1)Minocycline 90 mg/kg intraperitoneally(i.p.)at 15 min ROSC,followed by 22.5 mg/kg i.p.every 12 h for 72 h;and(2)Controls,receiving the same volume of vehicle(phosphate-buffered saline).The rats were kept normothermic during the postoperative course.Neurologic injury was assessed daily using Overall Performance Category(OPC;1=normal,5=dead)and Neurologic Deficit Score(NDS;0%=normal,100%=dead).Rats were sacrificed at 72 h.Neuronal degeneration(Fluoro-Jade C staining)and microglia proliferation(anti-Iba-1 staining)were quantified in four selectively vulnerable brain regions(hippocampus,striatum,cerebellum,cortex)by three independent reviewers masked to the group assignment.RESULTS In the minocycline group,8 out of 14 rats survived to 72 h compared to 8 out of 19 rats in the control group(P=0.46).The degree of neurologic deficit at 72 h[median,(interquartile range)]was not different between survivors in minocycline vs controls:OPC 1.5(1-2.75)vs 2(1.25-3),P=0.442;NDS 12(2-20)vs 17(7-51),P=0.328)or between all studied rats.The number of degenerating neurons(minocycline vs controls,mean±SEM:Hippocampus 58±8 vs 76±8;striatum 121±43 vs 153±32;cerebellum 20±7 vs 22±8;cortex 0±0 vs 0±0)or proliferating microglia(hippocampus 157±15 vs 193 cortex 0±0 vs 0±0;16;striatum 150±22 vs 161±23;cerebellum 20±7 vs 22±8;cortex 26±6 vs 31±7)was not different between groups in any region(all P>0.05).Numerically,there were approximately 20%less degenerating neurons and proliferating microglia in the hippocampus and striatum in the minocycline group,with a consistent pattern of histological damage across the individual regions of interest.CONCLUSION Minocycline did not improve survival and failed to confer substantial benefits on neurologic function,neuronal loss or microglial proliferation across multiple brain regions in our model of rat VF CA.
基金Supported by the National Natural Science Foundation of China(11975116)。
文摘In this paper we analyze and discuss 2D Jackiw-Teitelboim(JT)gravity coupled to primary fermion fields in asymptotically anti-de Sitter(AdS)spacetimes.We obtain a particular solution of the massless Dirac field outside the extremal black hole horizon and find the solution for the dilaton in JT gravity.As two dimensional JT gravity spacetime is conformally flat,we calculate the two point correlators of primary fermion fields under the Weyl transformations.The primary goal of this work is to present a standard technique,called resolvent,rather than using CFT methods.We redefine the fields in terms of the conformal factor as fermion fields and use the resolvent technique to derive the renormalized entanglement entropy for massless Dirac fields in JT gravity.
