The clinical management of hypertrophic scars(HSs)remains challenging due to their complex etiology and heterogeneous morphology,underscoring the need for multitarget treatment strategies.In this study,we developed a ...The clinical management of hypertrophic scars(HSs)remains challenging due to their complex etiology and heterogeneous morphology,underscoring the need for multitarget treatment strategies.In this study,we developed a nanocomposite system constructed through the metal-phenolic network-mediated self-assembly of molybdenum polyoxometalate({Mo 154})and epigallocatechin gallate(EGCG),followed by chitosan encapsulation,to generate chitosan-encapsulated{Mo 154}/EGCG(CME)nanoparticles.These nanoparticles were integrated into dissolvable microneedles(CME@MN)to enable transdermal administration.Under near-infrared laser irradiation,CME exhibited a three-pronged therapeutic effect:suppression of collagen overproduction and excessive extracellular matrix(ECM)deposition in human keloid fibroblasts,regulation of proliferation and migration in human umbilical vein endothelial cells,and reprogramming of macrophages toward a proinflammatory M1 phenotype.In vivo,CME@MN patches preferentially accumulated within scar tissue,where they normalized ECM organization,improved collagen fiber rearrangement,and attenuated fibroblast activity through photothermal-enhanced mechanisms while maintaining an excellent safety profile.The CME@MN system represents a potentially transformative approach to HS management by offering a unified platform that simultaneously targets the fibrotic,angiogenic,and inflammatory components of scar pathogenesis.展开更多
The prediction of sea surface partial pressure of carbon dioxide(pCO_(2))in the South China Sea is crucial for understanding the region’s contribution to the global carbon budget and its interactions with climate cha...The prediction of sea surface partial pressure of carbon dioxide(pCO_(2))in the South China Sea is crucial for understanding the region’s contribution to the global carbon budget and its interactions with climate change.We applied the Spatiotemporal Convolutional Long Short-Term Memory(STConvLSTM)model,integrating key environmental factors including sea surface temperature(SST),sea surface salinity(SSS),and chlorophyll a(Chl a),to predict and analyze sea surface pCO_(2)in the South China Sea.The model demonstrated high accuracy in short-term predictions(1 month),with a mean absolute error(MAE)of 0.394,a root mean square error(RMSE)of 0.659,and a coefficient of determination(R^(2))of 0.998.For long-term predictions(12 months),the model maintained its predictive capability,with an MAE of 0.667,RMSE of 1.255,and R^(2)of 0.994.Feature importance analysis revealed that sea surface pCO_(2)and SST were the main drivers of the model’s predictions,whereas Chl a and SSS had relatively minor impacts.The model’s generalization ability was further validated in the northwest Pacific Ocean and tropical Pacific Ocean,where it successfully captured the spatiotemporal variation in pCO_(2)with small prediction errors.The ST-ConvLSTM model provides an efficient and accurate tool for forecasting and analyzing sea surface pCO_(2)in the South China Sea,offering new insights into global carbon cycling and climate change.This study demonstrates the potential of deep learning in marine science and provides a significant technical support for global changes and marine ecosystem research.展开更多
With the rapid development of intelligent navigation technology,efficient and safe path planning for mobile robots has become a core requirement.To address the challenges of complex dynamic environments,this paper pro...With the rapid development of intelligent navigation technology,efficient and safe path planning for mobile robots has become a core requirement.To address the challenges of complex dynamic environments,this paper proposes an intelligent path planning framework based on grid map modeling.First,an improved Safe and Smooth A*(SSA*)algorithm is employed for global path planning.By incorporating obstacle expansion and cornerpoint optimization,the proposed SSA*enhances the safety and smoothness of the planned path.Then,a Partitioned Dynamic Window Approach(PDWA)is integrated for local planning,which is triggered when dynamic or sudden static obstacles appear,enabling real-time obstacle avoidance and path adjustment.A unified objective function is constructed,considering path length,safety,and smoothness comprehensively.Multiple simulation experiments are conducted on typical port grid maps.The results demonstrate that the improved SSA*significantly reduces the number of expanded nodes and computation time in static environmentswhile generating smoother and safer paths.Meanwhile,the PDWA exhibits strong real-time performance and robustness in dynamic scenarios,achieving shorter paths and lower planning times compared to other graph search algorithms.The proposedmethodmaintains stable performance across maps of different scales and various port scenarios,verifying its practicality and potential for wider application.展开更多
Measurements from geomagnetic satellites continue to underpin advances in geomagnetic field models that describe Earth's internally generated magnetic field.Here,we present a new field model,MSCM,that integrates v...Measurements from geomagnetic satellites continue to underpin advances in geomagnetic field models that describe Earth's internally generated magnetic field.Here,we present a new field model,MSCM,that integrates vector and scalar data from the Swarm,China Seismo-Electromagnetic Satellite(CSES),and Macao Science Satellite-1(MSS-1)missions.The model spans from 2014.0 to 2024.5,incorporating the core,lithospheric,and magnetospheric fields,and it shows characteristics similar to other published models based on different data.For the first time,we demonstrate that it is possible to successfully construct a geomagnetic field model that incorporates CSES vector data,albeit one in which the radial and azimuthal CSES vector components are Huber downweighted.We further show that data from the MSS-1 can be integrated within an explicitly smoothed,fully time-dependent model description.Using the MSCM,we identify new behavior of the South Atlantic Anomaly,the broad region of low magnetic field intensity over the southern Atlantic.This prominent feature appears split into a western part and an eastern part,each with its own intensity minimum.Since 2015,the principal western minimum has undergone only modest intensity decreases of 290 nT and westward motion of 20 km per year,whereas the recently formed eastern minimum has shown a 2–3 times greater intensity drop of 730 nT with no apparent east-west motion.展开更多
BACKGROUND Understanding the type and extent of coronary artery involvement in patients with acute type A aortic dissection(ATAAD)is vital for surgical planning.The Neri classification has been proposed as a guide for...BACKGROUND Understanding the type and extent of coronary artery involvement in patients with acute type A aortic dissection(ATAAD)is vital for surgical planning.The Neri classification has been proposed as a guide for surgical strategies,however,its prognostic impact on postoperative mortality rates remains understudied in large-scale cohorts.METHODS We reviewed 600 ATAAD patients who underwent surgery and coronary computed tomography angiography from 2016 to 2020 at Fuwai Hospital,National Center for Cardiovascular Diseases,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing,China.Patients were classified based on the Neri classification system:no coronary artery involvement,type A(ostial involvement),type B(dissection in coronary body),and type C(circumferential detachment or complete avulsion).The primary endpoint was 30-day mortality.RESULTS Overall,28.3%of the patients had coronary artery involvement,with Neri type A,Neri type B,and Neri type C accounting for 13.3%,11.2%,and 3.8%,respectively.The right coronary artery was more frequently involved(25.3%)than the left coronary artery(8.0%).In the unadjusted analysis,patients with coronary artery involvement exhibited a numerically higher 30-day mortality compared to those without(5.3%vs.2.3%)(OR=2.35,95%CI:0.94–5.88,P=0.07),though this difference did not reach statistical significance.However,multivariable adjustment revealed significant association(adjusted OR=3.71,95%CI:1.05–13.13,P=0.04).Interestingly,after additional adjustment for coronary artery bypass grafting,the impact of coronary artery involvement on 30-day mortality no longer remained statistically significant(adjusted OR=3.13,95%CI:0.85–11.58,P=0.09).The 1-year mortality was higher in those with coronary artery involvement,but this significant association disappeared after adjusting for potential confounding variables.Furthermore,no significant difference in 30-day and 1-year mortality were observed among patients with different Neri classifications.CONCLUSIONS In patients with ATAAD who undergo surgery,the presence of coronary artery involvement is significantly associated with an increased risk of 30-day mortality.Proactive coronary artery bypass grafting may potentially mitigate the adverse impact of coronary artery involvement on 30-day mortality.展开更多
With the rapid advancement of technology,artificial intelligence(AI)has emerged as a transformative force in gastroenterology,particularly in diagnosing upper gastrointestinal diseases such as Barrett's esophagus(...With the rapid advancement of technology,artificial intelligence(AI)has emerged as a transformative force in gastroenterology,particularly in diagnosing upper gastrointestinal diseases such as Barrett's esophagus(BE),esophageal cancer,gastroesophageal reflux disease(GERD),and esophagogastric varices.AI's capabilities in image analysis,classification,detection,and segmentation have significantly improved diagnostic accuracy and efficiency.For BE,AI models achieve high sensitivity and specificity in detecting early neoplastic changes and guiding targeted biopsies.In esophageal cancer,AI enhances early lesion detection,improving intervention success rates.For GERD,AI classifies disease severity based on the Los Angeles grading system and accurately segments lesions.Additionally,AI detects esophagogastric varices and predicts bleeding risks more effectively than traditional methods.Despite these advancements,challenges remain,including the need for high-quality data,multi-center validation,and ensuring AI model interpretability.Future research should address these issues and further integrate AI into clinical practice to optimize patient outcomes.This review highlights AI's transformative impact on upper gastrointestinal disease diagnosis,emphasizing its potential to revolutionize endoscopic practice and improve patient care.展开更多
Decarbonizing offshore oil and gas platforms has become a critical challenge in the energy transition.In this article,we propose the following two models for decarbonizing offshore oil and gas platforms to facilitate ...Decarbonizing offshore oil and gas platforms has become a critical challenge in the energy transition.In this article,we propose the following two models for decarbonizing offshore oil and gas platforms to facilitate highly challenging energy transitions:(1)repurposing decommissioned platforms as offshore wind-hydrogen hubs and(2)integrating offshore wind power and hydrogen production systems into operational platforms.This study is conducted to systematically assess the feasibility of the proposed models and further examine their technological challenges,systemic risks,and possible mitigation pathways.The results showed that wind turbines,reverse osmosis desalination,and alkaline water electrolysis have high levels of maturity,whereas subsea hydrogen pipelines and liquid/compressed hydrogen carriers remain comparatively immature.Both models can significantly lower costs,strengthen energy resilience,and reduce emissions.However,large-scale deployment is generally constrained by high capital costs,integration complexity,and fragmented regulatory frameworks.The findings highlight that reusing offshore infrastructure to integrate offshore wind power and hydrogen production systems offers cost and environmental advantages over conventional decommissioning,while integrated supply systems can ensure long-term stability through multi-energy complementarity.The study provides strategic insights for advancing low-carbon transformation and guiding the sustainable and resilient development of offshore energy systems.展开更多
The expansive spectral coverage and superior optical properties of lithium niobate(LN)offer a comprehensive suite of tools for exploring novel functionalities.Achieving high-quality(Q)photonic resonator cavities is cr...The expansive spectral coverage and superior optical properties of lithium niobate(LN)offer a comprehensive suite of tools for exploring novel functionalities.Achieving high-quality(Q)photonic resonator cavities is crucial for enhancing light-matter interactions.However,this task is challenging as the device performance is heavily dependent on the fabrication quality of the LN.In this paper,we present experimental validation of an etchless approach to fabricating high-Q photonic crystal nanobeam cavities(PCNBCs).We successfully fabricate PCNBCs with Q factors exceeding 105 while maintaining high transmittance by capitalizing on the low waveguide loss and high fabrication tolerance of TE-polarized mode.Remarkably,the Q factor achieved here exceeds previous reports on etchless LN PCNBCs by over an order of magnitude.Benefiting from this advancement,we further explore a variety of optical functions,including thermo-optic tuning,optically induced bistability,and Fano line shapes generation.These findings present promising prospects for a versatile platform technique,facilitating the development of high-performance electro-optic or acousto-optic modulators,optical logic devices,and quantum photonics,highlighting its significant impact in the field of photonic integration.展开更多
Postoperative ileus(POI)remains a prevalent and significant challenge following abdominal surgeries,precipitating patient distress,prolonged hospital stays,and escalated medical expenditures.Conventionally addressed v...Postoperative ileus(POI)remains a prevalent and significant challenge following abdominal surgeries,precipitating patient distress,prolonged hospital stays,and escalated medical expenditures.Conventionally addressed via pharmacological interventions,POI is increasingly being explored through adjunctive therapeutic strategies,with acupuncture gaining recognition as a promising option.Acupuncture has demonstrated encouraging potential in promoting gastrointestinal motility in patients with POI.Moreover,recent research has shed light on the therapeutic mechanisms underlying its efficacy.This article aims to present a comprehensive overview of acupuncture as a treatment for POI,highlighting advancements in clinical research and recent elucidations of its mechanistic underpinnings.It aspires to contribute a pivotal reference point for scholars and enthusiasts keen on garnering a deeper understanding of acupuncture’s role in managing POI.展开更多
Benzylisoquinoline alkaloids(BIAs)are a structurally diverse group of plant metabolites renowned for their pharmacological properties.However,sustainable sources for these compounds remain limited.Consequently,researc...Benzylisoquinoline alkaloids(BIAs)are a structurally diverse group of plant metabolites renowned for their pharmacological properties.However,sustainable sources for these compounds remain limited.Consequently,researchers are focusing on elucidating BIA biosynthetic pathways and genes to explore alternative sources using synthetic biology approaches.CYP80B,a family of cytochrome P450(CYP450)enzymes,plays a crucial role in BIA biosynthesis.Previously reported CYP80Bs are known to catalyze the 3′-hydroxylation of(S)-Nmethylcoclaurine,with the N-methyl group essential for catalytic activity.In this study,we successfully cloned a full-length CYP80B gene(St CYP80B)from Stephania tetrandra(S.tetrandra)and identified its function using a yeast heterologous expression system.Both in vivo yeast feeding and in vitro enzyme analysis demonstrated that St CYP80B could catalyze Nmethylcoclaurine and coclaurine into their respective 3'-hydroxylated products.Notably,St CYP80B exhibited an expanded substrate selectivity compared to previously reported wildtype CYP80Bs,as it did not require an N-methyl group for hydroxylase activity.Furthermore,St CYP80B displayed a clear preference for the(S)-configuration.Co-expression of St CYP80B with the CYP450 reductases(CPRs,StCPR1,and StCPR2),also cloned from S.tetrandra,significantly enhanced the catalytic activity towards(S)-coclaurine.Site-directed mutagenesis of St CYP80B revealed that the residue H205 is crucial for coclaurine catalysis.Additionally,St CYP80B exhibited tissue-specific expression in plants.This study provides new genetic resources for the biosynthesis of BIAs and further elucidates their synthetic pathway in natural plant systems.展开更多
基金the financial support from the Fujian Provincial Youth Top-Notch Talent Support Program,China.
文摘The clinical management of hypertrophic scars(HSs)remains challenging due to their complex etiology and heterogeneous morphology,underscoring the need for multitarget treatment strategies.In this study,we developed a nanocomposite system constructed through the metal-phenolic network-mediated self-assembly of molybdenum polyoxometalate({Mo 154})and epigallocatechin gallate(EGCG),followed by chitosan encapsulation,to generate chitosan-encapsulated{Mo 154}/EGCG(CME)nanoparticles.These nanoparticles were integrated into dissolvable microneedles(CME@MN)to enable transdermal administration.Under near-infrared laser irradiation,CME exhibited a three-pronged therapeutic effect:suppression of collagen overproduction and excessive extracellular matrix(ECM)deposition in human keloid fibroblasts,regulation of proliferation and migration in human umbilical vein endothelial cells,and reprogramming of macrophages toward a proinflammatory M1 phenotype.In vivo,CME@MN patches preferentially accumulated within scar tissue,where they normalized ECM organization,improved collagen fiber rearrangement,and attenuated fibroblast activity through photothermal-enhanced mechanisms while maintaining an excellent safety profile.The CME@MN system represents a potentially transformative approach to HS management by offering a unified platform that simultaneously targets the fibrotic,angiogenic,and inflammatory components of scar pathogenesis.
基金Supported by the National Key Research and Development Program of China(No.2023YFC3008202)the National Natural Science Foundation of China(No.42406019)the Scientific Research Fund of Zhejiang Provincial Education Department(No.Y202353066)。
文摘The prediction of sea surface partial pressure of carbon dioxide(pCO_(2))in the South China Sea is crucial for understanding the region’s contribution to the global carbon budget and its interactions with climate change.We applied the Spatiotemporal Convolutional Long Short-Term Memory(STConvLSTM)model,integrating key environmental factors including sea surface temperature(SST),sea surface salinity(SSS),and chlorophyll a(Chl a),to predict and analyze sea surface pCO_(2)in the South China Sea.The model demonstrated high accuracy in short-term predictions(1 month),with a mean absolute error(MAE)of 0.394,a root mean square error(RMSE)of 0.659,and a coefficient of determination(R^(2))of 0.998.For long-term predictions(12 months),the model maintained its predictive capability,with an MAE of 0.667,RMSE of 1.255,and R^(2)of 0.994.Feature importance analysis revealed that sea surface pCO_(2)and SST were the main drivers of the model’s predictions,whereas Chl a and SSS had relatively minor impacts.The model’s generalization ability was further validated in the northwest Pacific Ocean and tropical Pacific Ocean,where it successfully captured the spatiotemporal variation in pCO_(2)with small prediction errors.The ST-ConvLSTM model provides an efficient and accurate tool for forecasting and analyzing sea surface pCO_(2)in the South China Sea,offering new insights into global carbon cycling and climate change.This study demonstrates the potential of deep learning in marine science and provides a significant technical support for global changes and marine ecosystem research.
文摘With the rapid development of intelligent navigation technology,efficient and safe path planning for mobile robots has become a core requirement.To address the challenges of complex dynamic environments,this paper proposes an intelligent path planning framework based on grid map modeling.First,an improved Safe and Smooth A*(SSA*)algorithm is employed for global path planning.By incorporating obstacle expansion and cornerpoint optimization,the proposed SSA*enhances the safety and smoothness of the planned path.Then,a Partitioned Dynamic Window Approach(PDWA)is integrated for local planning,which is triggered when dynamic or sudden static obstacles appear,enabling real-time obstacle avoidance and path adjustment.A unified objective function is constructed,considering path length,safety,and smoothness comprehensively.Multiple simulation experiments are conducted on typical port grid maps.The results demonstrate that the improved SSA*significantly reduces the number of expanded nodes and computation time in static environmentswhile generating smoother and safer paths.Meanwhile,the PDWA exhibits strong real-time performance and robustness in dynamic scenarios,achieving shorter paths and lower planning times compared to other graph search algorithms.The proposedmethodmaintains stable performance across maps of different scales and various port scenarios,verifying its practicality and potential for wider application.
基金supported by the National Natural Science Foundation of China(Grant No.42274003)PWL was supported by Swarm DISC(Swarm Data,Innovation,and Science Cluster)+2 种基金funded by the European Space Agency(ESAContract No.4000109587)HFR acknowledges funding from the UK Natural Environment Research Council(Grant No.NE/V010867/1)。
文摘Measurements from geomagnetic satellites continue to underpin advances in geomagnetic field models that describe Earth's internally generated magnetic field.Here,we present a new field model,MSCM,that integrates vector and scalar data from the Swarm,China Seismo-Electromagnetic Satellite(CSES),and Macao Science Satellite-1(MSS-1)missions.The model spans from 2014.0 to 2024.5,incorporating the core,lithospheric,and magnetospheric fields,and it shows characteristics similar to other published models based on different data.For the first time,we demonstrate that it is possible to successfully construct a geomagnetic field model that incorporates CSES vector data,albeit one in which the radial and azimuthal CSES vector components are Huber downweighted.We further show that data from the MSS-1 can be integrated within an explicitly smoothed,fully time-dependent model description.Using the MSCM,we identify new behavior of the South Atlantic Anomaly,the broad region of low magnetic field intensity over the southern Atlantic.This prominent feature appears split into a western part and an eastern part,each with its own intensity minimum.Since 2015,the principal western minimum has undergone only modest intensity decreases of 290 nT and westward motion of 20 km per year,whereas the recently formed eastern minimum has shown a 2–3 times greater intensity drop of 730 nT with no apparent east-west motion.
基金supported by the National High Level Hospital Clinical Research Funding(No.2024-GSP-TJ-15&No.2023-GSP-QN-17)the Chinese Society of Cardiology’s Foundation(CSCF2023B03).
文摘BACKGROUND Understanding the type and extent of coronary artery involvement in patients with acute type A aortic dissection(ATAAD)is vital for surgical planning.The Neri classification has been proposed as a guide for surgical strategies,however,its prognostic impact on postoperative mortality rates remains understudied in large-scale cohorts.METHODS We reviewed 600 ATAAD patients who underwent surgery and coronary computed tomography angiography from 2016 to 2020 at Fuwai Hospital,National Center for Cardiovascular Diseases,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing,China.Patients were classified based on the Neri classification system:no coronary artery involvement,type A(ostial involvement),type B(dissection in coronary body),and type C(circumferential detachment or complete avulsion).The primary endpoint was 30-day mortality.RESULTS Overall,28.3%of the patients had coronary artery involvement,with Neri type A,Neri type B,and Neri type C accounting for 13.3%,11.2%,and 3.8%,respectively.The right coronary artery was more frequently involved(25.3%)than the left coronary artery(8.0%).In the unadjusted analysis,patients with coronary artery involvement exhibited a numerically higher 30-day mortality compared to those without(5.3%vs.2.3%)(OR=2.35,95%CI:0.94–5.88,P=0.07),though this difference did not reach statistical significance.However,multivariable adjustment revealed significant association(adjusted OR=3.71,95%CI:1.05–13.13,P=0.04).Interestingly,after additional adjustment for coronary artery bypass grafting,the impact of coronary artery involvement on 30-day mortality no longer remained statistically significant(adjusted OR=3.13,95%CI:0.85–11.58,P=0.09).The 1-year mortality was higher in those with coronary artery involvement,but this significant association disappeared after adjusting for potential confounding variables.Furthermore,no significant difference in 30-day and 1-year mortality were observed among patients with different Neri classifications.CONCLUSIONS In patients with ATAAD who undergo surgery,the presence of coronary artery involvement is significantly associated with an increased risk of 30-day mortality.Proactive coronary artery bypass grafting may potentially mitigate the adverse impact of coronary artery involvement on 30-day mortality.
文摘With the rapid advancement of technology,artificial intelligence(AI)has emerged as a transformative force in gastroenterology,particularly in diagnosing upper gastrointestinal diseases such as Barrett's esophagus(BE),esophageal cancer,gastroesophageal reflux disease(GERD),and esophagogastric varices.AI's capabilities in image analysis,classification,detection,and segmentation have significantly improved diagnostic accuracy and efficiency.For BE,AI models achieve high sensitivity and specificity in detecting early neoplastic changes and guiding targeted biopsies.In esophageal cancer,AI enhances early lesion detection,improving intervention success rates.For GERD,AI classifies disease severity based on the Los Angeles grading system and accurately segments lesions.Additionally,AI detects esophagogastric varices and predicts bleeding risks more effectively than traditional methods.Despite these advancements,challenges remain,including the need for high-quality data,multi-center validation,and ensuring AI model interpretability.Future research should address these issues and further integrate AI into clinical practice to optimize patient outcomes.This review highlights AI's transformative impact on upper gastrointestinal disease diagnosis,emphasizing its potential to revolutionize endoscopic practice and improve patient care.
基金supported by the Chinese Academy of Engineering,China(Grant No.2024-HZ-31-03).-。
文摘Decarbonizing offshore oil and gas platforms has become a critical challenge in the energy transition.In this article,we propose the following two models for decarbonizing offshore oil and gas platforms to facilitate highly challenging energy transitions:(1)repurposing decommissioned platforms as offshore wind-hydrogen hubs and(2)integrating offshore wind power and hydrogen production systems into operational platforms.This study is conducted to systematically assess the feasibility of the proposed models and further examine their technological challenges,systemic risks,and possible mitigation pathways.The results showed that wind turbines,reverse osmosis desalination,and alkaline water electrolysis have high levels of maturity,whereas subsea hydrogen pipelines and liquid/compressed hydrogen carriers remain comparatively immature.Both models can significantly lower costs,strengthen energy resilience,and reduce emissions.However,large-scale deployment is generally constrained by high capital costs,integration complexity,and fragmented regulatory frameworks.The findings highlight that reusing offshore infrastructure to integrate offshore wind power and hydrogen production systems offers cost and environmental advantages over conventional decommissioning,while integrated supply systems can ensure long-term stability through multi-energy complementarity.The study provides strategic insights for advancing low-carbon transformation and guiding the sustainable and resilient development of offshore energy systems.
基金the National Key R&D Program of China(No.2022ZD0119002)the National Natural Science Foundation of China(Grant No.62025402,62090033,92364204,92264202 and 62293522)Major Program of Zhejiang Natural Science Foundation(Grant No.LDT23F04024F04)。
文摘The expansive spectral coverage and superior optical properties of lithium niobate(LN)offer a comprehensive suite of tools for exploring novel functionalities.Achieving high-quality(Q)photonic resonator cavities is crucial for enhancing light-matter interactions.However,this task is challenging as the device performance is heavily dependent on the fabrication quality of the LN.In this paper,we present experimental validation of an etchless approach to fabricating high-Q photonic crystal nanobeam cavities(PCNBCs).We successfully fabricate PCNBCs with Q factors exceeding 105 while maintaining high transmittance by capitalizing on the low waveguide loss and high fabrication tolerance of TE-polarized mode.Remarkably,the Q factor achieved here exceeds previous reports on etchless LN PCNBCs by over an order of magnitude.Benefiting from this advancement,we further explore a variety of optical functions,including thermo-optic tuning,optically induced bistability,and Fano line shapes generation.These findings present promising prospects for a versatile platform technique,facilitating the development of high-performance electro-optic or acousto-optic modulators,optical logic devices,and quantum photonics,highlighting its significant impact in the field of photonic integration.
基金Supported by Clinical Key Project of Peking University Third Hospital,No.BYSY2023049Funding from State Key Laboratory of Female Fertility Promotion,Center for Reproductive Medicine,Department of Obstetrics and Gynecology,Peking University Third Hospital,No.BYSYSZKF2023027.
文摘Postoperative ileus(POI)remains a prevalent and significant challenge following abdominal surgeries,precipitating patient distress,prolonged hospital stays,and escalated medical expenditures.Conventionally addressed via pharmacological interventions,POI is increasingly being explored through adjunctive therapeutic strategies,with acupuncture gaining recognition as a promising option.Acupuncture has demonstrated encouraging potential in promoting gastrointestinal motility in patients with POI.Moreover,recent research has shed light on the therapeutic mechanisms underlying its efficacy.This article aims to present a comprehensive overview of acupuncture as a treatment for POI,highlighting advancements in clinical research and recent elucidations of its mechanistic underpinnings.It aspires to contribute a pivotal reference point for scholars and enthusiasts keen on garnering a deeper understanding of acupuncture’s role in managing POI.
文摘Benzylisoquinoline alkaloids(BIAs)are a structurally diverse group of plant metabolites renowned for their pharmacological properties.However,sustainable sources for these compounds remain limited.Consequently,researchers are focusing on elucidating BIA biosynthetic pathways and genes to explore alternative sources using synthetic biology approaches.CYP80B,a family of cytochrome P450(CYP450)enzymes,plays a crucial role in BIA biosynthesis.Previously reported CYP80Bs are known to catalyze the 3′-hydroxylation of(S)-Nmethylcoclaurine,with the N-methyl group essential for catalytic activity.In this study,we successfully cloned a full-length CYP80B gene(St CYP80B)from Stephania tetrandra(S.tetrandra)and identified its function using a yeast heterologous expression system.Both in vivo yeast feeding and in vitro enzyme analysis demonstrated that St CYP80B could catalyze Nmethylcoclaurine and coclaurine into their respective 3'-hydroxylated products.Notably,St CYP80B exhibited an expanded substrate selectivity compared to previously reported wildtype CYP80Bs,as it did not require an N-methyl group for hydroxylase activity.Furthermore,St CYP80B displayed a clear preference for the(S)-configuration.Co-expression of St CYP80B with the CYP450 reductases(CPRs,StCPR1,and StCPR2),also cloned from S.tetrandra,significantly enhanced the catalytic activity towards(S)-coclaurine.Site-directed mutagenesis of St CYP80B revealed that the residue H205 is crucial for coclaurine catalysis.Additionally,St CYP80B exhibited tissue-specific expression in plants.This study provides new genetic resources for the biosynthesis of BIAs and further elucidates their synthetic pathway in natural plant systems.
