During rock drilling and blasting activities,stemming blast holes is to prevent high-pressure explosive gases from the holes,thereby enhancing the overall blasting effectiveness.Hence,it is imperative to investigate t...During rock drilling and blasting activities,stemming blast holes is to prevent high-pressure explosive gases from the holes,thereby enhancing the overall blasting effectiveness.Hence,it is imperative to investigate the dynamic mechanical properties of the stem-ming materials.In this study,impact compression tests were conducted on self-swelling cartridges(SSCs)using a split Hopkinson pres-sure bar(SHPB),aiming to evaluate dynamic performances across strain rate range of 20 to 65 s^(−1).Test results indicate that the dynamic compressive strength of SSCs exhibits the following trends:it increases with increasing density of SSC,decreases with an increase in insertion gap,and follows an initial rise and subsequent fall trend with an increase in water absorption.The order of significance among these factors is density>water absorption>insertion gaps.SSCs exhibit a pronounced strain-rate strengthening dependence in dynamic compressive strength.Furthermore,both the compressive peak stress and peak strain of SSCs follow a well-defined quadratic upward trend with increasing strain rates.As the strain rate increases,the degree of fragmentation,absorbed energy,and dynamic increase factor exhibit an upward trend.Model experimental results indicate that,compared to cementitious stemming materials,SSCs can prolong the duration of gas explosion action.Therefore,SSCs are more suitable for high strain-rate applications such as blasting stemming and rock burst control.展开更多
Based on the blasting theory and stress wave theory, stemming mechanism and movement of stemmed material in rock blasting were analyzed and the calculation expression of stemming lengths was deduced. The blasting expe...Based on the blasting theory and stress wave theory, stemming mechanism and movement of stemmed material in rock blasting were analyzed and the calculation expression of stemming lengths was deduced. The blasting experiment with different stemming lengths was carried out and the results show that the theoretical stemming length, which is 0.73 ~ 0.8 time of burden, is in the range of the experiential length, which is O. 63 - O. 88 time of burden. The blasting results of field experiments with theoretical stemming length are satisfactory, which shows the theoretical derivation and analysis are correct and reliable. The results will supply rock blasting with the theoretical gist of parameters design.展开更多
To the Editor：Irreversible electroporation （IRE） is a CE- and FDA- approved treatment modality for pancreatic and liver tumors that is based on the site-confined destruction of tumor tissue by multiple short, high-...To the Editor：Irreversible electroporation （IRE） is a CE- and FDA- approved treatment modality for pancreatic and liver tumors that is based on the site-confined destruction of tumor tissue by multiple short, high-intensity electrical pulses.展开更多
Arabic, as one of the Semitic languages, has a very rich and complex morphology, which is radically different from the European and the East Asian languages. The derivational system of Arabic, is therefore, based on r...Arabic, as one of the Semitic languages, has a very rich and complex morphology, which is radically different from the European and the East Asian languages. The derivational system of Arabic, is therefore, based on roots, which are often inflected to compose words, using a spectacular and a relatively large set of Arabic morphemes affixes, e.g., antefixs, prefixes, suffixes, etc. Stemming is the process of rendering all the inflected forms of word into a common canonical form. Stemming is one of the early and major phases in natural processing, machine translation and information retrieval tasks. A number of Arabic language stemmers were proposed. Examples include light stemming, morphological analysis, statistical-based stemming, N-grams and parallel corpora (collections). Motivated by the reported results in the literature, this paper attempts to exhaustively review current achievements for stemming Arabic texts. A variety of algorithms are discussed. The main contribution of the paper is to provide better understanding among existing approaches with the hope of building an error-free and effective Arabic stemmer in the near future.展开更多
Stemming is used to produce stem or root of words. The process is vital to different research fields such as text mining, sentiment analysis, and text categorization, etc. Several techniques have been proposed to stem...Stemming is used to produce stem or root of words. The process is vital to different research fields such as text mining, sentiment analysis, and text categorization, etc. Several techniques have been proposed to stemming Arabic text and among them, Khoja and light-10 stemmers are the most widely used. In this paper, we propose and evaluate two different stemming techniques to Arabic that are based on light stemming techniques. The new stemmers are compared to best reported light stemmer, which is light-10. Results and experiments, which were conducted using standard collections, reveal that The proposed stemmers yield 5.13% and 13.1% improvement in retrieval performance over light 10 with 0.369 average precision and 0.397, respectively and the improvement is statistically significant.展开更多
Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen...Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen,and essential nutrients to brain tissues.This deprivation triggers a cascade of cellular events that ultimately leads to neuronal death.Recent studies have clarified the multifactorial pathogenesis of ischemic stroke,highlighting the roles of energy failure,excitotoxicity,oxidative stress,neuroinflammation,and apoptosis.This review aimed to provide a comprehensive insight into the fundamental mechanisms driving neuronal death triggered by ischemia and to examine the progress of neuroprotective therapeutic approaches designed to mitigate neuronal loss and promote neurological recovery after a stroke.Additionally,we explored widely accepted findings regarding the potential pathways implicated in neuronal death during ischemic stroke,including the interplay of apoptosis,autophagy,pyroptosis,ferroptosis,and necrosis,which collectively influence neuronal fate.We also discussed advancements in neuroprotective therapeutics,encompassing a range of interventions from pharmacological modulation to stem cell-based therapies,aimed at reducing neuronal injury and enhancing functional recovery following ischemic stroke.Despite these advancements,challenges remain in translating mechanistic insights into effective clinical therapies.Although neuroprotective strategies have shown promise in preclinical models,their efficacy in human trials has been inconsistent,often due to the complex pathology of ischemic stroke and the timing of interventions.In conclusion,this review synthesizes mechanistic insights into the intricate interplay of molecular and cellular pathways driving neuronal death post-ischemia.It sheds light on cutting-edge advancements in potential neuroprotective therapeutics,underscores the promise of regenerative medicine,and offers a forward-looking perspective on potential clinical breakthroughs.The ongoing evolution of precision-targeted interventions is expected to significantly enhance preventative strategies and improve clinical outcomes.展开更多
Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microgl...Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.展开更多
Traumatic optic neuropathy is a form of optic neuropathy resulting from trauma.Its pathophysiological mechanisms involve primary and secondary injury phases,leading to progressive retinal ganglion cell loss and axonal...Traumatic optic neuropathy is a form of optic neuropathy resulting from trauma.Its pathophysiological mechanisms involve primary and secondary injury phases,leading to progressive retinal ganglion cell loss and axonal degeneration.Contributing factors such as physical trauma,oxidative stress,neuroinflammation,and glial scar formation exacerbate disease progression and retinal ganglion cell death.Multiple forms of cell death—including apoptosis,pyroptosis,necroptosis,and ferroptosis—are involved at different disease stages.Although current treatments,such as corticosteroid therapy and surgical interventions,have limited efficacy,cell-based therapies have emerged as a promising approach that simultaneously promotes neuroprotection and retinal ganglion cell regeneration.This review summarizes recent advances in cell-based therapies for traumatic optic neuropathy.In the context of cell replacement therapy,retinal ganglion cell-like cells derived from embryonic stem cells and induced pluripotent stem cells—via chemical induction or direct reprogramming—have demonstrated the ability to integrate into the host retina and survive for weeks to months,potentially improving visual function.Mesenchymal stem cells derived from various sources,including bone marrow,umbilical cord,placenta,and adipose tissue,have been shown to enhance retinal ganglion cell survival,stimulate axonal regeneration,and support partial functional recovery.Additionally,neural stem/progenitor cells derived from human embryonic stem cells offer neuroprotective effects and function as“neuronal relays,”facilitating reconnection between damaged regions of the optic nerve and the visual pathway.Beyond direct cell transplantation,cell-derived products,such as extracellular vesicles and cell-extracted solutions,have demonstrated promising neuroprotective effects in traumatic optic neuropathy.Despite significant progress,several challenges remain,including limited integration of transplanted cells,suboptimal functional vision recovery,the need for precise timing and delivery methods,and an incomplete understanding of the role of the retinal microenvironment and glial cell activation in neuroprotection and neuroregeneration.Furthermore,studies with longer observation periods and deeper mechanistic insights into the therapeutic effects of cell-based therapies remain scarce.Two Phase I clinical trials have confirmed the safety and potential benefits of cell-based therapy for traumatic optic neuropathy,with reported improvements in visual acuity.However,further studies are needed to validate these findings and establish significant therapeutic outcomes.In conclusion,cell-based therapies hold great promise for treating traumatic optic neuropathy,but critical obstacles must be overcome to achieve functional optic nerve regeneration.Emerging bioengineering strategies,such as scaffold-based transplantation,may improve cell survival and axonal guidance.Successful clinical translation will require rigorous preclinical validation,standardized protocols,and the integration of advanced imaging techniques to optimize therapeutic efficacy.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51874068 and 52074062)the Open Funds from the Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,China(No.DM2023B03).
文摘During rock drilling and blasting activities,stemming blast holes is to prevent high-pressure explosive gases from the holes,thereby enhancing the overall blasting effectiveness.Hence,it is imperative to investigate the dynamic mechanical properties of the stem-ming materials.In this study,impact compression tests were conducted on self-swelling cartridges(SSCs)using a split Hopkinson pres-sure bar(SHPB),aiming to evaluate dynamic performances across strain rate range of 20 to 65 s^(−1).Test results indicate that the dynamic compressive strength of SSCs exhibits the following trends:it increases with increasing density of SSC,decreases with an increase in insertion gap,and follows an initial rise and subsequent fall trend with an increase in water absorption.The order of significance among these factors is density>water absorption>insertion gaps.SSCs exhibit a pronounced strain-rate strengthening dependence in dynamic compressive strength.Furthermore,both the compressive peak stress and peak strain of SSCs follow a well-defined quadratic upward trend with increasing strain rates.As the strain rate increases,the degree of fragmentation,absorbed energy,and dynamic increase factor exhibit an upward trend.Model experimental results indicate that,compared to cementitious stemming materials,SSCs can prolong the duration of gas explosion action.Therefore,SSCs are more suitable for high strain-rate applications such as blasting stemming and rock burst control.
文摘Based on the blasting theory and stress wave theory, stemming mechanism and movement of stemmed material in rock blasting were analyzed and the calculation expression of stemming lengths was deduced. The blasting experiment with different stemming lengths was carried out and the results show that the theoretical stemming length, which is 0.73 ~ 0.8 time of burden, is in the range of the experiential length, which is O. 63 - O. 88 time of burden. The blasting results of field experiments with theoretical stemming length are satisfactory, which shows the theoretical derivation and analysis are correct and reliable. The results will supply rock blasting with the theoretical gist of parameters design.
文摘To the Editor：Irreversible electroporation （IRE） is a CE- and FDA- approved treatment modality for pancreatic and liver tumors that is based on the site-confined destruction of tumor tissue by multiple short, high-intensity electrical pulses.
文摘Arabic, as one of the Semitic languages, has a very rich and complex morphology, which is radically different from the European and the East Asian languages. The derivational system of Arabic, is therefore, based on roots, which are often inflected to compose words, using a spectacular and a relatively large set of Arabic morphemes affixes, e.g., antefixs, prefixes, suffixes, etc. Stemming is the process of rendering all the inflected forms of word into a common canonical form. Stemming is one of the early and major phases in natural processing, machine translation and information retrieval tasks. A number of Arabic language stemmers were proposed. Examples include light stemming, morphological analysis, statistical-based stemming, N-grams and parallel corpora (collections). Motivated by the reported results in the literature, this paper attempts to exhaustively review current achievements for stemming Arabic texts. A variety of algorithms are discussed. The main contribution of the paper is to provide better understanding among existing approaches with the hope of building an error-free and effective Arabic stemmer in the near future.
文摘Stemming is used to produce stem or root of words. The process is vital to different research fields such as text mining, sentiment analysis, and text categorization, etc. Several techniques have been proposed to stemming Arabic text and among them, Khoja and light-10 stemmers are the most widely used. In this paper, we propose and evaluate two different stemming techniques to Arabic that are based on light stemming techniques. The new stemmers are compared to best reported light stemmer, which is light-10. Results and experiments, which were conducted using standard collections, reveal that The proposed stemmers yield 5.13% and 13.1% improvement in retrieval performance over light 10 with 0.369 average precision and 0.397, respectively and the improvement is statistically significant.
基金supported by the National Natural Science Foundation of China,Nos.82171387 and 31830111(both to SL).
文摘Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen,and essential nutrients to brain tissues.This deprivation triggers a cascade of cellular events that ultimately leads to neuronal death.Recent studies have clarified the multifactorial pathogenesis of ischemic stroke,highlighting the roles of energy failure,excitotoxicity,oxidative stress,neuroinflammation,and apoptosis.This review aimed to provide a comprehensive insight into the fundamental mechanisms driving neuronal death triggered by ischemia and to examine the progress of neuroprotective therapeutic approaches designed to mitigate neuronal loss and promote neurological recovery after a stroke.Additionally,we explored widely accepted findings regarding the potential pathways implicated in neuronal death during ischemic stroke,including the interplay of apoptosis,autophagy,pyroptosis,ferroptosis,and necrosis,which collectively influence neuronal fate.We also discussed advancements in neuroprotective therapeutics,encompassing a range of interventions from pharmacological modulation to stem cell-based therapies,aimed at reducing neuronal injury and enhancing functional recovery following ischemic stroke.Despite these advancements,challenges remain in translating mechanistic insights into effective clinical therapies.Although neuroprotective strategies have shown promise in preclinical models,their efficacy in human trials has been inconsistent,often due to the complex pathology of ischemic stroke and the timing of interventions.In conclusion,this review synthesizes mechanistic insights into the intricate interplay of molecular and cellular pathways driving neuronal death post-ischemia.It sheds light on cutting-edge advancements in potential neuroprotective therapeutics,underscores the promise of regenerative medicine,and offers a forward-looking perspective on potential clinical breakthroughs.The ongoing evolution of precision-targeted interventions is expected to significantly enhance preventative strategies and improve clinical outcomes.
基金supported by the Natural Science Foundation of Yunnan Province,No.202401AS070086(to ZW)the National Key Research and Development Program of China,No.2018YFA0801403(to ZW)+1 种基金Yunnan Science and Technology Talent and Platform Plan,No.202105AC160041(to ZW)the Natural Science Foundation of China,No.31960120(to ZW)。
文摘Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.
基金supported by the National Key Research and Development Program of China,No.2022YFA1105502(to PG)the National Natural Science Foundation of China,Nos.82271123(to PG),32200618(to ZT)。
文摘Traumatic optic neuropathy is a form of optic neuropathy resulting from trauma.Its pathophysiological mechanisms involve primary and secondary injury phases,leading to progressive retinal ganglion cell loss and axonal degeneration.Contributing factors such as physical trauma,oxidative stress,neuroinflammation,and glial scar formation exacerbate disease progression and retinal ganglion cell death.Multiple forms of cell death—including apoptosis,pyroptosis,necroptosis,and ferroptosis—are involved at different disease stages.Although current treatments,such as corticosteroid therapy and surgical interventions,have limited efficacy,cell-based therapies have emerged as a promising approach that simultaneously promotes neuroprotection and retinal ganglion cell regeneration.This review summarizes recent advances in cell-based therapies for traumatic optic neuropathy.In the context of cell replacement therapy,retinal ganglion cell-like cells derived from embryonic stem cells and induced pluripotent stem cells—via chemical induction or direct reprogramming—have demonstrated the ability to integrate into the host retina and survive for weeks to months,potentially improving visual function.Mesenchymal stem cells derived from various sources,including bone marrow,umbilical cord,placenta,and adipose tissue,have been shown to enhance retinal ganglion cell survival,stimulate axonal regeneration,and support partial functional recovery.Additionally,neural stem/progenitor cells derived from human embryonic stem cells offer neuroprotective effects and function as“neuronal relays,”facilitating reconnection between damaged regions of the optic nerve and the visual pathway.Beyond direct cell transplantation,cell-derived products,such as extracellular vesicles and cell-extracted solutions,have demonstrated promising neuroprotective effects in traumatic optic neuropathy.Despite significant progress,several challenges remain,including limited integration of transplanted cells,suboptimal functional vision recovery,the need for precise timing and delivery methods,and an incomplete understanding of the role of the retinal microenvironment and glial cell activation in neuroprotection and neuroregeneration.Furthermore,studies with longer observation periods and deeper mechanistic insights into the therapeutic effects of cell-based therapies remain scarce.Two Phase I clinical trials have confirmed the safety and potential benefits of cell-based therapy for traumatic optic neuropathy,with reported improvements in visual acuity.However,further studies are needed to validate these findings and establish significant therapeutic outcomes.In conclusion,cell-based therapies hold great promise for treating traumatic optic neuropathy,but critical obstacles must be overcome to achieve functional optic nerve regeneration.Emerging bioengineering strategies,such as scaffold-based transplantation,may improve cell survival and axonal guidance.Successful clinical translation will require rigorous preclinical validation,standardized protocols,and the integration of advanced imaging techniques to optimize therapeutic efficacy.
