Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive im...Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this response.Following traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain regions.Homeostatic astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are overexpressed.This altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive recovery.In addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional recovery.Current therapeutic strategies for traumatic brain injury are focused on preventing acute complications.Statins,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of astrocytes.In this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRNAs or lncRNA,viral vectors,and repurposed drugs.展开更多
Objective: Pregnancy in a scarred uterus is considered to be high-risk, especially during parturition. Nevertheless, the literature favours vaginal delivery as long as obstetric conditions are favourable. The aim of o...Objective: Pregnancy in a scarred uterus is considered to be high-risk, especially during parturition. Nevertheless, the literature favours vaginal delivery as long as obstetric conditions are favourable. The aim of our study was to contribute to the improvement of delivery management for women with scar uteri at the CHU Communautaire. Methodology: This was a cross-sectional study conducted over an 18-month period from 01 January 2020 to 30 June 2021 on women with scar uterus who came to give birth at the CHU Communautaire maternity unit. The sample was exhaustive;any parturient with a history of scarred uterus of more than one year with a clinically normal pelvis and whose fetus was in cephalic presentation. The following were excluded from the study: pregnant women with a uterine scar of less than one year, fetuses in a non-cephalic vertex presentation, pregnant women with antecedent complicated childbirth at the previous cesarean section, large fetuses informed consent had been obtained from the pregnant women. Anomynia was respected throughout the study. Results: During this period, we recorded 205 parturients with a scar uterus. The incidence of delivery with a scar uterus was 9.5%. Uterine testing was attempted in 85.9% of cases, with a success rate of 75.6%. Factors predictive of a successful uterine test was: maternal age less than 35 years (P = 0.0027), entry into labour at the reference maternity hospital (P Conclusion: Delivery with a scarred uterus is an increasingly frequent occurrence at the Maternity Unit of the CHU Communautaire in Bangui. Uterine testing is the first option if conditions allow, but careful selection of candidates during antenatal care or at the very beginning of labour is necessary for this type of delivery.展开更多
Introduction: Childbirth on a scarred uterus is a major issue for health centers, especially peripheral, due to the major obstetric risks it presents. The objectives were to evaluate the frequency, route of delivery a...Introduction: Childbirth on a scarred uterus is a major issue for health centers, especially peripheral, due to the major obstetric risks it presents. The objectives were to evaluate the frequency, route of delivery and maternal-fetal prognosis of this type of delivery at csref of Kolondiéba. Materials and Methods: This was a retrospective cross-sectional study for one year (1 January 2023-31 December 2023). All patients admitted to the maternity ward of the center with at least one uterine scar and treated in the center were included. We extracted data from partograms, OR records, birth records and obstetric records. Input was done on Excel 2010 and analysis on SPSS.23. Results: The frequency of scarring uterus was 16.8% (217/1285 births). The average age was 27. Pauciparous were most represented (59%). Patients were received from community health centers (44.7%). Prenatal consultation sessions (1 - 3 sessions) were performed at (64.9%). Uterine scars were obstetric in (99%). The cesarean section was performed immediately in (59.4%), it was prophylactic in 17%. The uterine test was attempted in (25.34%) with (69%) success. We recorded 3.6% uterine ruptures, 8.7% postoperative complications, 5.5% stillbirths and one maternal death (0.46%). Conclusion: Births on a scarred uterus are frequent and associated with a high rate of complications.展开更多
Many staple crops like wheat,soybeans,and maize stubbornly resist regrowing from lab-grown tissues-a major bottleneck for genetic modification and improvement of these crops.A Cell study in June 2024 may become a game...Many staple crops like wheat,soybeans,and maize stubbornly resist regrowing from lab-grown tissues-a major bottleneck for genetic modification and improvement of these crops.A Cell study in June 2024 may become a game-changer.Led by Dr.DENG Lei(Shandong Agricultural University)and Dr.LI Chuanyou(the CAS Institute of Genetics and Developmental Biology),the collaborative effort identified a peptide called REGENERATION FACTOR1(REF1)as a local wound signal that regulates damage-triggered tissue repair and organ regeneration.This very finding may greatly expand opportunities for improving crop resilience through targeted bioengineering.展开更多
Objective:To investigate the delivery modes of women with repeat pregnancies involving uterine scars and their effects on both mothers and neonates.Methods:A study was conducted on 100 patients treated at Shenzhen Mat...Objective:To investigate the delivery modes of women with repeat pregnancies involving uterine scars and their effects on both mothers and neonates.Methods:A study was conducted on 100 patients treated at Shenzhen Maternity and Child Healthcare Hospital from July 2023 to July 2024.The participants were divided into a control group and an observation group,with 50 cases in each.The division was based on the indications for prior cesarean section,cervical maturity,postpartum complications,and thickness of the cesarean scar.The control group underwent cesarean delivery,while the observation group experienced vaginal delivery.The two groups were compared in terms of intrapartum blood loss,postpartum blood loss within 2 hours,length of hospital stay,Apgar scores at 1-minute post-birth,and incidences of neonatal fever and jaundice.Results:The observation group had significantly lower intrapartum blood loss,postpartum blood loss within 2 hours,and shorter hospital stays compared to the control group(P<0.05).Additionally,the Apgar scores at 1 minute post-birth were significantly higher in the observation group(P<0.05).The incidence of neonatal fever and jaundice was significantly lower in the observation group(P<0.05).These differences were statistically significant.Conclusion:Vaginal delivery has high clinical value for women with repeat pregnancies involving uterine scars.It reduces maternal intrapartum and postpartum blood loss,shortens hospital stays,improves neonatal Apgar scores,and decreases the incidences of neonatal fever and jaundice.This method is worthy of clinical application and promotion.展开更多
Hypertrophic scars(HS)are fibrotic proliferative diseases that develop after deep skin injuries caused by trauma,burns,and surgery.Traditional treatment methods include both surgical and nonsurgical therapies.Early in...Hypertrophic scars(HS)are fibrotic proliferative diseases that develop after deep skin injuries caused by trauma,burns,and surgery.Traditional treatment methods include both surgical and nonsurgical therapies.Early intervention and combination therapy tailored to the individual needs of the patients are crucial for achieving optimal results.Three-dimensional(3D)printing technology,a rapid prototyping technique,is increasingly being applied in the medical field.The customization and precise functionality of 3D printing technology are particularly important for the rehabilitation of HS.This review provides an overview of HS and the role of 3D printing technology in medical applications,analyses the application of 3D-printed rehabilitation aids for HS,and discusses the use of 3D printing technology to improve HS treatment outcomes,thereby providing clinical guidance for effective HS rehabilitation.展开更多
Quantum many-body systems lie at the heart of modern fundamental physics.The study of these systems has revealed a plethora of fascinating phenomena,such as quantum thermalization,many-body localization,and quantum ma...Quantum many-body systems lie at the heart of modern fundamental physics.The study of these systems has revealed a plethora of fascinating phenomena,such as quantum thermalization,many-body localization,and quantum many-body scars.This review provides a comprehensive overview of the recent advances in understanding quantum many-body scars and non-ergodic dynamics in quantum systems on superconducting-circuit platforms,ranging from theoretical mechanisms and effective models to experimental observations.展开更多
Colorectal polyps remain a significant health concern because they can develop into cancer.Therefore,accurate assessment and diagnosis of polyps,along with appropriate treatment decisions,are crucial in preventing com...Colorectal polyps remain a significant health concern because they can develop into cancer.Therefore,accurate assessment and diagnosis of polyps,along with appropriate treatment decisions,are crucial in preventing complications or malignant transformation.Some polyps are classified as complex polyps,which means they fail to elevate due to a scar from a previously removed polyp or can be determined by a scoring system like the size/morphology/site/access score,which considers factors like site,morphology,size,and access.Management of complex colorectal polyps involves various options,including endoscopic and surgical approaches.Endoscopic mucosal resection(EMR)may be challenging in scarred polyps,as inadequate lifting can result in incomplete resection or recurrence.As a more advanced alternative,endoscopic submucosal dissection(ESD)is suitable for larger lesions,enabling en-bloc resection even in complex cases with EMR.However,ESD requires expertise and is more time-consuming than EMR,often necessitating hospitalization due to its complexity.Endoscopic full-thickness resection could be a viable alternative for managing scarred polyps.Endoscopic powered resection,either alone or in combination with other modalities,can also be used to achieve less extensive resection.Managing complications during the procedure or post-procedurally is equally important,as bleeding or perforations can be fatal.Careful patient selection based on individual profiles and risk factors,along with the identification of any signs of malignancy,is crucial before treatment to avoid negative post-treatment outcomes.展开更多
Objective:To evaluate the clinical efficacy of vaginal repair as a salvage treatment for cesarean scar defects in patients with previously failed repair surgery.Methods:This retrospective cohort study included 16 pati...Objective:To evaluate the clinical efficacy of vaginal repair as a salvage treatment for cesarean scar defects in patients with previously failed repair surgery.Methods:This retrospective cohort study included 16 patients with cesarean scar defects who underwent vaginal repair as salvage therapy after prior repair surgery failure between March 2019 and September 2022 at the Department of Obstetrics and Gynecology,Xinhua Hospital,Shanghai Jiao Tong University School of Medicine.The previous failed procedures included vaginal repair,hysteroscopic repair,and laparoscopic repair.A control group of 108 patients who underwent primary vaginal repair during the same period was also analyzed.Perioperative outcomes and post-operative repair efficacy were compared.The length,width,and depth of the cesarean scar defect,as well as the thickness of the residual myometrium,were measured by transvaginal ultrasonography.Results:No significant differences were observed between the two groups in demographic characteristics.In both groups,the duration of menstruation significantly decreased after vaginal repair(from 12.8±5.3 to 6.75±1.8 days in the salvage therapy group,and from 13.5±3.8 to 7.1±1.7 days in the primary surgery group),while the thickness of the residual myometrium significantly increased(from 3.0±2.0 to 7.7±2.6 mm in the salvage therapy group,and from 2.6±1.2 to 7.7±2.5 mm in the primary surgery group).Post-operatively,there were no significant differences between the two groups in either menstrual duration(6.8±1.8vs.7.1±1.7 days)or residual myometrial thickness(7.7±2.6vs.7.7±2.5 mm).The data also indicated that performing salvage therapy within≤21 months of the initial surgery was associated with a better prognosis.Conclusions:Vaginal repair as salvage therapy is a feasible and effective option for patients with cesarean scar defects after failed repair surgery.展开更多
We investigate the quantum dynamics of the 1D spinless Fermi-Hubbard model with a linear-tilted potential.Surprisingly in a strong resonance regime,we show that the model can be described by the kinetically constraine...We investigate the quantum dynamics of the 1D spinless Fermi-Hubbard model with a linear-tilted potential.Surprisingly in a strong resonance regime,we show that the model can be described by the kinetically constrained effective Hamiltonian,and it can be spontaneously divided into two commuting parts dubbed Hamiltonian dimerization,which are composed of two distinct sets of constrained nearest-neighbor hopping terms:one set acting exclusively on odd bonds and the other on even bonds.Specifically it is shown that each part can be independently mapped onto the well-known PXP model;therefore the dimerized Hamiltonian is equivalent to a two-fold PXP model.As a consequence,we numerically demonstrate this system can host the so-called quantum many-body scars,which present dynamical revivals and ergodicity-breaking behaviors.However,in sharp contrast with traditional quantum many-body scars,here the scarring states in our model driven by different parts of the Hamiltonian will revive in different periods,and those of double parts can display a biperiodic revival pattern,both originating from the Hamiltonian dimerization.Besides,the condition of off-resonance is also discussed,and we show the crossover from quantum many-body scar to ergodicity breaking is diagnosed via level statistics.Our model provides a platform for understanding the interplay of Hilbert space fragmentation and the constrained quantum systems.展开更多
Traumatic injury to the adult mammalian central nervous system（CNS） leads to complex cellular responses. Among them, the scar tissue formed is generally recognized as a major obstacle to CNS repair, both by the prod...Traumatic injury to the adult mammalian central nervous system（CNS） leads to complex cellular responses. Among them, the scar tissue formed is generally recognized as a major obstacle to CNS repair, both by the production of inhibitory molecules and by the physical impedance of axon regrowth. Therefore, scar-modulating treatments have become a leading therapeutic intervention for CNS injury. To date, a variety of biological and pharmaceutical treatments, targeting scar modulation, have been tested in animal models of CNS injury, and a few are likely to enter clinical trials. In this review, we summarize current knowledge of the scar-modulating treatments according to their specific aims：（1） inhibition of glial and fibrotic scar formation, and（2） blockade of the production of scar-associated inhibitory molecules. The removal of existing scar tissue is also discussed as a treatment of choice. It is believed that only a combinatorial strategy is likely to help eliminate the detrimental effects of scar tissue on CNS repair.展开更多
基金supported by grants PICT 2019-08512017-2203,UBACYT and PIP CONICET(to AJR).
文摘Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this response.Following traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain regions.Homeostatic astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are overexpressed.This altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive recovery.In addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional recovery.Current therapeutic strategies for traumatic brain injury are focused on preventing acute complications.Statins,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of astrocytes.In this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRNAs or lncRNA,viral vectors,and repurposed drugs.
文摘Objective: Pregnancy in a scarred uterus is considered to be high-risk, especially during parturition. Nevertheless, the literature favours vaginal delivery as long as obstetric conditions are favourable. The aim of our study was to contribute to the improvement of delivery management for women with scar uteri at the CHU Communautaire. Methodology: This was a cross-sectional study conducted over an 18-month period from 01 January 2020 to 30 June 2021 on women with scar uterus who came to give birth at the CHU Communautaire maternity unit. The sample was exhaustive;any parturient with a history of scarred uterus of more than one year with a clinically normal pelvis and whose fetus was in cephalic presentation. The following were excluded from the study: pregnant women with a uterine scar of less than one year, fetuses in a non-cephalic vertex presentation, pregnant women with antecedent complicated childbirth at the previous cesarean section, large fetuses informed consent had been obtained from the pregnant women. Anomynia was respected throughout the study. Results: During this period, we recorded 205 parturients with a scar uterus. The incidence of delivery with a scar uterus was 9.5%. Uterine testing was attempted in 85.9% of cases, with a success rate of 75.6%. Factors predictive of a successful uterine test was: maternal age less than 35 years (P = 0.0027), entry into labour at the reference maternity hospital (P Conclusion: Delivery with a scarred uterus is an increasingly frequent occurrence at the Maternity Unit of the CHU Communautaire in Bangui. Uterine testing is the first option if conditions allow, but careful selection of candidates during antenatal care or at the very beginning of labour is necessary for this type of delivery.
文摘Introduction: Childbirth on a scarred uterus is a major issue for health centers, especially peripheral, due to the major obstetric risks it presents. The objectives were to evaluate the frequency, route of delivery and maternal-fetal prognosis of this type of delivery at csref of Kolondiéba. Materials and Methods: This was a retrospective cross-sectional study for one year (1 January 2023-31 December 2023). All patients admitted to the maternity ward of the center with at least one uterine scar and treated in the center were included. We extracted data from partograms, OR records, birth records and obstetric records. Input was done on Excel 2010 and analysis on SPSS.23. Results: The frequency of scarring uterus was 16.8% (217/1285 births). The average age was 27. Pauciparous were most represented (59%). Patients were received from community health centers (44.7%). Prenatal consultation sessions (1 - 3 sessions) were performed at (64.9%). Uterine scars were obstetric in (99%). The cesarean section was performed immediately in (59.4%), it was prophylactic in 17%. The uterine test was attempted in (25.34%) with (69%) success. We recorded 3.6% uterine ruptures, 8.7% postoperative complications, 5.5% stillbirths and one maternal death (0.46%). Conclusion: Births on a scarred uterus are frequent and associated with a high rate of complications.
文摘Many staple crops like wheat,soybeans,and maize stubbornly resist regrowing from lab-grown tissues-a major bottleneck for genetic modification and improvement of these crops.A Cell study in June 2024 may become a game-changer.Led by Dr.DENG Lei(Shandong Agricultural University)and Dr.LI Chuanyou(the CAS Institute of Genetics and Developmental Biology),the collaborative effort identified a peptide called REGENERATION FACTOR1(REF1)as a local wound signal that regulates damage-triggered tissue repair and organ regeneration.This very finding may greatly expand opportunities for improving crop resilience through targeted bioengineering.
文摘Objective:To investigate the delivery modes of women with repeat pregnancies involving uterine scars and their effects on both mothers and neonates.Methods:A study was conducted on 100 patients treated at Shenzhen Maternity and Child Healthcare Hospital from July 2023 to July 2024.The participants were divided into a control group and an observation group,with 50 cases in each.The division was based on the indications for prior cesarean section,cervical maturity,postpartum complications,and thickness of the cesarean scar.The control group underwent cesarean delivery,while the observation group experienced vaginal delivery.The two groups were compared in terms of intrapartum blood loss,postpartum blood loss within 2 hours,length of hospital stay,Apgar scores at 1-minute post-birth,and incidences of neonatal fever and jaundice.Results:The observation group had significantly lower intrapartum blood loss,postpartum blood loss within 2 hours,and shorter hospital stays compared to the control group(P<0.05).Additionally,the Apgar scores at 1 minute post-birth were significantly higher in the observation group(P<0.05).The incidence of neonatal fever and jaundice was significantly lower in the observation group(P<0.05).These differences were statistically significant.Conclusion:Vaginal delivery has high clinical value for women with repeat pregnancies involving uterine scars.It reduces maternal intrapartum and postpartum blood loss,shortens hospital stays,improves neonatal Apgar scores,and decreases the incidences of neonatal fever and jaundice.This method is worthy of clinical application and promotion.
基金supported by the Cross-Disciplinary Research Fund Project of the Shanghai Ninth People’s Hospital of Shanghai Jiao Tong University School of Medicine(grant no.JYJC202236)the Shanghai Plastic Surgery Research Center of Shanghai Priority Research Center(grant no.2023ZZ02023)the Shanghai Healthcare System Key Supporting Disciplines Program(grant no.2023ZDFC0303).
文摘Hypertrophic scars(HS)are fibrotic proliferative diseases that develop after deep skin injuries caused by trauma,burns,and surgery.Traditional treatment methods include both surgical and nonsurgical therapies.Early intervention and combination therapy tailored to the individual needs of the patients are crucial for achieving optimal results.Three-dimensional(3D)printing technology,a rapid prototyping technique,is increasingly being applied in the medical field.The customization and precise functionality of 3D printing technology are particularly important for the rehabilitation of HS.This review provides an overview of HS and the role of 3D printing technology in medical applications,analyses the application of 3D-printed rehabilitation aids for HS,and discusses the use of 3D printing technology to improve HS treatment outcomes,thereby providing clinical guidance for effective HS rehabilitation.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LD25A050002)the National Natural Science Foundation of China(No.12375021)the National Key Research and Development Program of China(No.2022YFA1404203).
文摘Quantum many-body systems lie at the heart of modern fundamental physics.The study of these systems has revealed a plethora of fascinating phenomena,such as quantum thermalization,many-body localization,and quantum many-body scars.This review provides a comprehensive overview of the recent advances in understanding quantum many-body scars and non-ergodic dynamics in quantum systems on superconducting-circuit platforms,ranging from theoretical mechanisms and effective models to experimental observations.
文摘Colorectal polyps remain a significant health concern because they can develop into cancer.Therefore,accurate assessment and diagnosis of polyps,along with appropriate treatment decisions,are crucial in preventing complications or malignant transformation.Some polyps are classified as complex polyps,which means they fail to elevate due to a scar from a previously removed polyp or can be determined by a scoring system like the size/morphology/site/access score,which considers factors like site,morphology,size,and access.Management of complex colorectal polyps involves various options,including endoscopic and surgical approaches.Endoscopic mucosal resection(EMR)may be challenging in scarred polyps,as inadequate lifting can result in incomplete resection or recurrence.As a more advanced alternative,endoscopic submucosal dissection(ESD)is suitable for larger lesions,enabling en-bloc resection even in complex cases with EMR.However,ESD requires expertise and is more time-consuming than EMR,often necessitating hospitalization due to its complexity.Endoscopic full-thickness resection could be a viable alternative for managing scarred polyps.Endoscopic powered resection,either alone or in combination with other modalities,can also be used to achieve less extensive resection.Managing complications during the procedure or post-procedurally is equally important,as bleeding or perforations can be fatal.Careful patient selection based on individual profiles and risk factors,along with the identification of any signs of malignancy,is crucial before treatment to avoid negative post-treatment outcomes.
基金Ministry of Science and Technology of China(2020YFC2002800,2020YFC2002803)。
文摘Objective:To evaluate the clinical efficacy of vaginal repair as a salvage treatment for cesarean scar defects in patients with previously failed repair surgery.Methods:This retrospective cohort study included 16 patients with cesarean scar defects who underwent vaginal repair as salvage therapy after prior repair surgery failure between March 2019 and September 2022 at the Department of Obstetrics and Gynecology,Xinhua Hospital,Shanghai Jiao Tong University School of Medicine.The previous failed procedures included vaginal repair,hysteroscopic repair,and laparoscopic repair.A control group of 108 patients who underwent primary vaginal repair during the same period was also analyzed.Perioperative outcomes and post-operative repair efficacy were compared.The length,width,and depth of the cesarean scar defect,as well as the thickness of the residual myometrium,were measured by transvaginal ultrasonography.Results:No significant differences were observed between the two groups in demographic characteristics.In both groups,the duration of menstruation significantly decreased after vaginal repair(from 12.8±5.3 to 6.75±1.8 days in the salvage therapy group,and from 13.5±3.8 to 7.1±1.7 days in the primary surgery group),while the thickness of the residual myometrium significantly increased(from 3.0±2.0 to 7.7±2.6 mm in the salvage therapy group,and from 2.6±1.2 to 7.7±2.5 mm in the primary surgery group).Post-operatively,there were no significant differences between the two groups in either menstrual duration(6.8±1.8vs.7.1±1.7 days)or residual myometrial thickness(7.7±2.6vs.7.7±2.5 mm).The data also indicated that performing salvage therapy within≤21 months of the initial surgery was associated with a better prognosis.Conclusions:Vaginal repair as salvage therapy is a feasible and effective option for patients with cesarean scar defects after failed repair surgery.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406002)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301200)。
文摘We investigate the quantum dynamics of the 1D spinless Fermi-Hubbard model with a linear-tilted potential.Surprisingly in a strong resonance regime,we show that the model can be described by the kinetically constrained effective Hamiltonian,and it can be spontaneously divided into two commuting parts dubbed Hamiltonian dimerization,which are composed of two distinct sets of constrained nearest-neighbor hopping terms:one set acting exclusively on odd bonds and the other on even bonds.Specifically it is shown that each part can be independently mapped onto the well-known PXP model;therefore the dimerized Hamiltonian is equivalent to a two-fold PXP model.As a consequence,we numerically demonstrate this system can host the so-called quantum many-body scars,which present dynamical revivals and ergodicity-breaking behaviors.However,in sharp contrast with traditional quantum many-body scars,here the scarring states in our model driven by different parts of the Hamiltonian will revive in different periods,and those of double parts can display a biperiodic revival pattern,both originating from the Hamiltonian dimerization.Besides,the condition of off-resonance is also discussed,and we show the crossover from quantum many-body scar to ergodicity breaking is diagnosed via level statistics.Our model provides a platform for understanding the interplay of Hilbert space fragmentation and the constrained quantum systems.
基金supported by grants from the National Basic Research Development Program (973 Program) of China (2014CB542202)National High-Technology Research Program (863 Program) of China (2012AA020502)+1 种基金the National Natural Science Foundation of China (81130080)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,Jiangsu Province,China
文摘Traumatic injury to the adult mammalian central nervous system（CNS） leads to complex cellular responses. Among them, the scar tissue formed is generally recognized as a major obstacle to CNS repair, both by the production of inhibitory molecules and by the physical impedance of axon regrowth. Therefore, scar-modulating treatments have become a leading therapeutic intervention for CNS injury. To date, a variety of biological and pharmaceutical treatments, targeting scar modulation, have been tested in animal models of CNS injury, and a few are likely to enter clinical trials. In this review, we summarize current knowledge of the scar-modulating treatments according to their specific aims：（1） inhibition of glial and fibrotic scar formation, and（2） blockade of the production of scar-associated inhibitory molecules. The removal of existing scar tissue is also discussed as a treatment of choice. It is believed that only a combinatorial strategy is likely to help eliminate the detrimental effects of scar tissue on CNS repair.
