The last decade or so has seen the development of refined performance-based earthquake engineering(PBEE) approaches that now provide a framework for estimation of a range of important decision variables,such as repair...The last decade or so has seen the development of refined performance-based earthquake engineering(PBEE) approaches that now provide a framework for estimation of a range of important decision variables,such as repair costs,repair time and number of casualties. This paper reviews current tools for PBEE,including the PACT software,and examines the possibility of extending the innovative displacement-based assessment approach as a simplified structural analysis option for performance assessment. Details of the displacement-based s+eismic assessment method are reviewed and a simple means of quickly assessing multiple hazard levels is proposed. Furthermore,proposals for a simple definition of collapse fragility and relations between equivalent single-degree-of-freedom characteristics and multi-degree-of-freedom story drift and floor acceleration demands are discussed,highlighting needs for future research. To illustrate the potential of the methodology,performance measures obtained from the simplified method are compared with those computed using the results of incremental dynamic analyses within the PEER performance-based earthquake engineering framework,applied to a benchmark building. The comparison illustrates that the simplified method could be a very effective conceptual seismic design tool. The advantages and disadvantages of the simplified approach are discussed and potential implications of advanced seismic performance assessments for conceptual seismic design are highlighted through examination of different case study scenarios including different structural configurations.展开更多
After being approved by the National Drug Agency in several countries, Radium-223(Ra-223) is gaining wide acceptance in the treatment of bone metastatic castration resistant prostate cancer. The exact mechanism of act...After being approved by the National Drug Agency in several countries, Radium-223(Ra-223) is gaining wide acceptance in the treatment of bone metastatic castration resistant prostate cancer. The exact mechanism of action remain unclear: The established model of direct alpha-particle irradiation from the remodelling bone surface, where Ra-223 accumulates, surrounding the tumor foci can explain a lethal effect only on metastatic microdeposits, but not on higher tumor burden. According to the "pre-metastatic niche model", it is likely that Ra-223 targets several non-tumoral cell types of the tumor microenvironment involved in the complex mechanism of cancer bone homing and colonization. A deeper insight into this hypothetical mechanism will lead to a more accurate dosimetric approach and to find optimal sequencing and/or combination with the other therapeutic options.展开更多
To date,no vaccines or effective drugs have been approved to prevent or treat COVID-19 and the current standard care relies on supportive treatments.Therefore,based on the fast and global spread of the virus,urgent in...To date,no vaccines or effective drugs have been approved to prevent or treat COVID-19 and the current standard care relies on supportive treatments.Therefore,based on the fast and global spread of the virus,urgent investigations are warranted in order to develop preventive and therapeutic drugs.In this regard,treatments addressing the immunopathology of SARS-CoV-2 infection have become a major focus.Notably,while a rapid and well-coordinated immune response represents the first line of defense against viral infection,excessive inflammatory innate response and impaired adaptive host immune defense may lead to tissue damage both at the site of virus entry and at systemic level.Several studies highlight relevant changes occurring both in innate and adaptive immune system in COVID-19 patients.In particular,the massive cytokine and chemokine release,the so-called“cytokine storm”,clearly reflects a widespread uncontrolled dysregulation of the host immune defense.Although the prospective of counteracting cytokine storm is compelling,a major limitation relies on the limited understanding of the immune signaling pathways triggered by SARS-CoV-2 infection.The identification of signaling pathways altered during viral infections may help to unravel the most relevant molecular cascades implicated in biological processes mediating viral infections and to unveil key molecular players that may be targeted.Thus,given the key role of the immune system in COVID-19,a deeper understanding of the mechanism behind the immune dysregulation might give us clues for the clinical management of the severe cases and for preventing the transition from mild to severe stages.展开更多
The increasing awareness of the general society toward the seismic safety of structures has led to more restrictive performance requirements hence, many times, to the need of using new and more accurate methods of ana...The increasing awareness of the general society toward the seismic safety of structures has led to more restrictive performance requirements hence, many times, to the need of using new and more accurate methods of analysis of structures. Among these, nonlinear static procedures are becoming, evermore, the preferred choice of the majority of design codes, as an alternative to complete nonlinear time-history analysis for seismic design and assessment of structures. The many available software tools should therefore be evaluated and well understood, in order to be easily and soundly employed by the practitioners. The study presented herein intends to contribute to this need by providing further insight with respect to the use of commonly employed structural analysis software tools in nonlinear analysis of bridge structures. A comparison between different nonlinear modeling assumptions is presented, together with the comparison with real experimental results. Furthermore, alternative adaptive pushover procedures are proposed and applied to a case study bridge, based on a generic plastic hinge model. The adopted structural analysis program proved to be accurate, yielding reliable estimates, both in terms of local plastic hinge behavior and global structural behavior.展开更多
An elegant paper by Yuan et al.,recently published in Science,provides novel insights into the molecular features of neutralizing antibody responses to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).
In this paper we present the science potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies of strongly magnetized objects. We will focus on the physics and astrophysics of strongly magnetize...In this paper we present the science potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies of strongly magnetized objects. We will focus on the physics and astrophysics of strongly magnetized objects, namely magnetars, accreting X-ray pulsars, and rotation powered pulsars. We also discuss the science potential of eXTP for QED studies. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020s.展开更多
文摘The last decade or so has seen the development of refined performance-based earthquake engineering(PBEE) approaches that now provide a framework for estimation of a range of important decision variables,such as repair costs,repair time and number of casualties. This paper reviews current tools for PBEE,including the PACT software,and examines the possibility of extending the innovative displacement-based assessment approach as a simplified structural analysis option for performance assessment. Details of the displacement-based s+eismic assessment method are reviewed and a simple means of quickly assessing multiple hazard levels is proposed. Furthermore,proposals for a simple definition of collapse fragility and relations between equivalent single-degree-of-freedom characteristics and multi-degree-of-freedom story drift and floor acceleration demands are discussed,highlighting needs for future research. To illustrate the potential of the methodology,performance measures obtained from the simplified method are compared with those computed using the results of incremental dynamic analyses within the PEER performance-based earthquake engineering framework,applied to a benchmark building. The comparison illustrates that the simplified method could be a very effective conceptual seismic design tool. The advantages and disadvantages of the simplified approach are discussed and potential implications of advanced seismic performance assessments for conceptual seismic design are highlighted through examination of different case study scenarios including different structural configurations.
文摘After being approved by the National Drug Agency in several countries, Radium-223(Ra-223) is gaining wide acceptance in the treatment of bone metastatic castration resistant prostate cancer. The exact mechanism of action remain unclear: The established model of direct alpha-particle irradiation from the remodelling bone surface, where Ra-223 accumulates, surrounding the tumor foci can explain a lethal effect only on metastatic microdeposits, but not on higher tumor burden. According to the "pre-metastatic niche model", it is likely that Ra-223 targets several non-tumoral cell types of the tumor microenvironment involved in the complex mechanism of cancer bone homing and colonization. A deeper insight into this hypothetical mechanism will lead to a more accurate dosimetric approach and to find optimal sequencing and/or combination with the other therapeutic options.
基金supported by the University of Pavia(grants from FR&G 2019,Fondo Ricerca&Giovani,to C.L.).
文摘To date,no vaccines or effective drugs have been approved to prevent or treat COVID-19 and the current standard care relies on supportive treatments.Therefore,based on the fast and global spread of the virus,urgent investigations are warranted in order to develop preventive and therapeutic drugs.In this regard,treatments addressing the immunopathology of SARS-CoV-2 infection have become a major focus.Notably,while a rapid and well-coordinated immune response represents the first line of defense against viral infection,excessive inflammatory innate response and impaired adaptive host immune defense may lead to tissue damage both at the site of virus entry and at systemic level.Several studies highlight relevant changes occurring both in innate and adaptive immune system in COVID-19 patients.In particular,the massive cytokine and chemokine release,the so-called“cytokine storm”,clearly reflects a widespread uncontrolled dysregulation of the host immune defense.Although the prospective of counteracting cytokine storm is compelling,a major limitation relies on the limited understanding of the immune signaling pathways triggered by SARS-CoV-2 infection.The identification of signaling pathways altered during viral infections may help to unravel the most relevant molecular cascades implicated in biological processes mediating viral infections and to unveil key molecular players that may be targeted.Thus,given the key role of the immune system in COVID-19,a deeper understanding of the mechanism behind the immune dysregulation might give us clues for the clinical management of the severe cases and for preventing the transition from mild to severe stages.
文摘The increasing awareness of the general society toward the seismic safety of structures has led to more restrictive performance requirements hence, many times, to the need of using new and more accurate methods of analysis of structures. Among these, nonlinear static procedures are becoming, evermore, the preferred choice of the majority of design codes, as an alternative to complete nonlinear time-history analysis for seismic design and assessment of structures. The many available software tools should therefore be evaluated and well understood, in order to be easily and soundly employed by the practitioners. The study presented herein intends to contribute to this need by providing further insight with respect to the use of commonly employed structural analysis software tools in nonlinear analysis of bridge structures. A comparison between different nonlinear modeling assumptions is presented, together with the comparison with real experimental results. Furthermore, alternative adaptive pushover procedures are proposed and applied to a case study bridge, based on a generic plastic hinge model. The adopted structural analysis program proved to be accurate, yielding reliable estimates, both in terms of local plastic hinge behavior and global structural behavior.
基金supported by the University of Pavia(Grants from FR&G 2019,Fondo Ricerca&Giovani,to C.L.).
文摘An elegant paper by Yuan et al.,recently published in Science,provides novel insights into the molecular features of neutralizing antibody responses to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).
基金support of the Chinese Academy of Sciences through the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA15020100)supported by the Bundesministerium fuer Wirtschaft und Technologie through the Deutsches Zentrum fuer Luft-und Raumfahrte.V.(DLR)(Grant No.FKZ 50 OO 1701)Financial contribution from the agreement between the Italian Space Agency and the Istituto Nazionale di Astrofisica ASI-INAF n.2017-14H.O
文摘In this paper we present the science potential of the enhanced X-ray Timing and Polarimetry(eXTP) mission for studies of strongly magnetized objects. We will focus on the physics and astrophysics of strongly magnetized objects, namely magnetars, accreting X-ray pulsars, and rotation powered pulsars. We also discuss the science potential of eXTP for QED studies. Developed by an international Consortium led by the Institute of High Energy Physics of the Chinese Academy of Sciences, the eXTP mission is expected to be launched in the mid 2020s.
